Source file src/net/http/serve_test.go

     1  // Copyright 2010 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // End-to-end serving tests
     6  
     7  package http_test
     8  
     9  import (
    10  	"bufio"
    11  	"bytes"
    12  	"compress/gzip"
    13  	"compress/zlib"
    14  	"context"
    15  	"crypto/tls"
    16  	"crypto/x509"
    17  	"encoding/json"
    18  	"errors"
    19  	"fmt"
    20  	"internal/synctest"
    21  	"internal/testenv"
    22  	"io"
    23  	"log"
    24  	"math/rand"
    25  	"mime/multipart"
    26  	"net"
    27  	. "net/http"
    28  	"net/http/httptest"
    29  	"net/http/httptrace"
    30  	"net/http/httputil"
    31  	"net/http/internal"
    32  	"net/http/internal/testcert"
    33  	"net/url"
    34  	"os"
    35  	"path/filepath"
    36  	"reflect"
    37  	"regexp"
    38  	"runtime"
    39  	"slices"
    40  	"strconv"
    41  	"strings"
    42  	"sync"
    43  	"sync/atomic"
    44  	"syscall"
    45  	"testing"
    46  	"time"
    47  )
    48  
    49  type dummyAddr string
    50  type oneConnListener struct {
    51  	conn net.Conn
    52  }
    53  
    54  func (l *oneConnListener) Accept() (c net.Conn, err error) {
    55  	c = l.conn
    56  	if c == nil {
    57  		err = io.EOF
    58  		return
    59  	}
    60  	err = nil
    61  	l.conn = nil
    62  	return
    63  }
    64  
    65  func (l *oneConnListener) Close() error {
    66  	return nil
    67  }
    68  
    69  func (l *oneConnListener) Addr() net.Addr {
    70  	return dummyAddr("test-address")
    71  }
    72  
    73  func (a dummyAddr) Network() string {
    74  	return string(a)
    75  }
    76  
    77  func (a dummyAddr) String() string {
    78  	return string(a)
    79  }
    80  
    81  type noopConn struct{}
    82  
    83  func (noopConn) LocalAddr() net.Addr                { return dummyAddr("local-addr") }
    84  func (noopConn) RemoteAddr() net.Addr               { return dummyAddr("remote-addr") }
    85  func (noopConn) SetDeadline(t time.Time) error      { return nil }
    86  func (noopConn) SetReadDeadline(t time.Time) error  { return nil }
    87  func (noopConn) SetWriteDeadline(t time.Time) error { return nil }
    88  
    89  type rwTestConn struct {
    90  	io.Reader
    91  	io.Writer
    92  	noopConn
    93  
    94  	closeFunc func() error // called if non-nil
    95  	closec    chan bool    // else, if non-nil, send value to it on close
    96  }
    97  
    98  func (c *rwTestConn) Close() error {
    99  	if c.closeFunc != nil {
   100  		return c.closeFunc()
   101  	}
   102  	select {
   103  	case c.closec <- true:
   104  	default:
   105  	}
   106  	return nil
   107  }
   108  
   109  type testConn struct {
   110  	readMu   sync.Mutex // for TestHandlerBodyClose
   111  	readBuf  bytes.Buffer
   112  	writeBuf bytes.Buffer
   113  	closec   chan bool // 1-buffered; receives true when Close is called
   114  	noopConn
   115  }
   116  
   117  func newTestConn() *testConn {
   118  	return &testConn{closec: make(chan bool, 1)}
   119  }
   120  
   121  func (c *testConn) Read(b []byte) (int, error) {
   122  	c.readMu.Lock()
   123  	defer c.readMu.Unlock()
   124  	return c.readBuf.Read(b)
   125  }
   126  
   127  func (c *testConn) Write(b []byte) (int, error) {
   128  	return c.writeBuf.Write(b)
   129  }
   130  
   131  func (c *testConn) Close() error {
   132  	select {
   133  	case c.closec <- true:
   134  	default:
   135  	}
   136  	return nil
   137  }
   138  
   139  // reqBytes treats req as a request (with \n delimiters) and returns it with \r\n delimiters,
   140  // ending in \r\n\r\n
   141  func reqBytes(req string) []byte {
   142  	return []byte(strings.ReplaceAll(strings.TrimSpace(req), "\n", "\r\n") + "\r\n\r\n")
   143  }
   144  
   145  type handlerTest struct {
   146  	logbuf  bytes.Buffer
   147  	handler Handler
   148  }
   149  
   150  func newHandlerTest(h Handler) handlerTest {
   151  	return handlerTest{handler: h}
   152  }
   153  
   154  func (ht *handlerTest) rawResponse(req string) string {
   155  	reqb := reqBytes(req)
   156  	var output strings.Builder
   157  	conn := &rwTestConn{
   158  		Reader: bytes.NewReader(reqb),
   159  		Writer: &output,
   160  		closec: make(chan bool, 1),
   161  	}
   162  	ln := &oneConnListener{conn: conn}
   163  	srv := &Server{
   164  		ErrorLog: log.New(&ht.logbuf, "", 0),
   165  		Handler:  ht.handler,
   166  	}
   167  	go srv.Serve(ln)
   168  	<-conn.closec
   169  	return output.String()
   170  }
   171  
   172  func TestConsumingBodyOnNextConn(t *testing.T) {
   173  	t.Parallel()
   174  	defer afterTest(t)
   175  	conn := new(testConn)
   176  	for i := 0; i < 2; i++ {
   177  		conn.readBuf.Write([]byte(
   178  			"POST / HTTP/1.1\r\n" +
   179  				"Host: test\r\n" +
   180  				"Content-Length: 11\r\n" +
   181  				"\r\n" +
   182  				"foo=1&bar=1"))
   183  	}
   184  
   185  	reqNum := 0
   186  	ch := make(chan *Request)
   187  	servech := make(chan error)
   188  	listener := &oneConnListener{conn}
   189  	handler := func(res ResponseWriter, req *Request) {
   190  		reqNum++
   191  		ch <- req
   192  	}
   193  
   194  	go func() {
   195  		servech <- Serve(listener, HandlerFunc(handler))
   196  	}()
   197  
   198  	var req *Request
   199  	req = <-ch
   200  	if req == nil {
   201  		t.Fatal("Got nil first request.")
   202  	}
   203  	if req.Method != "POST" {
   204  		t.Errorf("For request #1's method, got %q; expected %q",
   205  			req.Method, "POST")
   206  	}
   207  
   208  	req = <-ch
   209  	if req == nil {
   210  		t.Fatal("Got nil first request.")
   211  	}
   212  	if req.Method != "POST" {
   213  		t.Errorf("For request #2's method, got %q; expected %q",
   214  			req.Method, "POST")
   215  	}
   216  
   217  	if serveerr := <-servech; serveerr != io.EOF {
   218  		t.Errorf("Serve returned %q; expected EOF", serveerr)
   219  	}
   220  }
   221  
   222  type stringHandler string
   223  
   224  func (s stringHandler) ServeHTTP(w ResponseWriter, r *Request) {
   225  	w.Header().Set("Result", string(s))
   226  }
   227  
   228  var handlers = []struct {
   229  	pattern string
   230  	msg     string
   231  }{
   232  	{"/", "Default"},
   233  	{"/someDir/", "someDir"},
   234  	{"/#/", "hash"},
   235  	{"someHost.com/someDir/", "someHost.com/someDir"},
   236  }
   237  
   238  var vtests = []struct {
   239  	url      string
   240  	expected string
   241  }{
   242  	{"http://localhost/someDir/apage", "someDir"},
   243  	{"http://localhost/%23/apage", "hash"},
   244  	{"http://localhost/otherDir/apage", "Default"},
   245  	{"http://someHost.com/someDir/apage", "someHost.com/someDir"},
   246  	{"http://otherHost.com/someDir/apage", "someDir"},
   247  	{"http://otherHost.com/aDir/apage", "Default"},
   248  	// redirections for trees
   249  	{"http://localhost/someDir", "/someDir/"},
   250  	{"http://localhost/%23", "/%23/"},
   251  	{"http://someHost.com/someDir", "/someDir/"},
   252  }
   253  
   254  func TestHostHandlers(t *testing.T) { run(t, testHostHandlers, []testMode{http1Mode}) }
   255  func testHostHandlers(t *testing.T, mode testMode) {
   256  	mux := NewServeMux()
   257  	for _, h := range handlers {
   258  		mux.Handle(h.pattern, stringHandler(h.msg))
   259  	}
   260  	ts := newClientServerTest(t, mode, mux).ts
   261  
   262  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
   263  	if err != nil {
   264  		t.Fatal(err)
   265  	}
   266  	defer conn.Close()
   267  	cc := httputil.NewClientConn(conn, nil)
   268  	for _, vt := range vtests {
   269  		var r *Response
   270  		var req Request
   271  		if req.URL, err = url.Parse(vt.url); err != nil {
   272  			t.Errorf("cannot parse url: %v", err)
   273  			continue
   274  		}
   275  		if err := cc.Write(&req); err != nil {
   276  			t.Errorf("writing request: %v", err)
   277  			continue
   278  		}
   279  		r, err := cc.Read(&req)
   280  		if err != nil {
   281  			t.Errorf("reading response: %v", err)
   282  			continue
   283  		}
   284  		switch r.StatusCode {
   285  		case StatusOK:
   286  			s := r.Header.Get("Result")
   287  			if s != vt.expected {
   288  				t.Errorf("Get(%q) = %q, want %q", vt.url, s, vt.expected)
   289  			}
   290  		case StatusMovedPermanently:
   291  			s := r.Header.Get("Location")
   292  			if s != vt.expected {
   293  				t.Errorf("Get(%q) = %q, want %q", vt.url, s, vt.expected)
   294  			}
   295  		default:
   296  			t.Errorf("Get(%q) unhandled status code %d", vt.url, r.StatusCode)
   297  		}
   298  	}
   299  }
   300  
   301  var serveMuxRegister = []struct {
   302  	pattern string
   303  	h       Handler
   304  }{
   305  	{"/dir/", serve(200)},
   306  	{"/search", serve(201)},
   307  	{"codesearch.google.com/search", serve(202)},
   308  	{"codesearch.google.com/", serve(203)},
   309  	{"example.com/", HandlerFunc(checkQueryStringHandler)},
   310  }
   311  
   312  // serve returns a handler that sends a response with the given code.
   313  func serve(code int) HandlerFunc {
   314  	return func(w ResponseWriter, r *Request) {
   315  		w.WriteHeader(code)
   316  	}
   317  }
   318  
   319  // checkQueryStringHandler checks if r.URL.RawQuery has the same value
   320  // as the URL excluding the scheme and the query string and sends 200
   321  // response code if it is, 500 otherwise.
   322  func checkQueryStringHandler(w ResponseWriter, r *Request) {
   323  	u := *r.URL
   324  	u.Scheme = "http"
   325  	u.Host = r.Host
   326  	u.RawQuery = ""
   327  	if "http://"+r.URL.RawQuery == u.String() {
   328  		w.WriteHeader(200)
   329  	} else {
   330  		w.WriteHeader(500)
   331  	}
   332  }
   333  
   334  var serveMuxTests = []struct {
   335  	method  string
   336  	host    string
   337  	path    string
   338  	code    int
   339  	pattern string
   340  }{
   341  	{"GET", "google.com", "/", 404, ""},
   342  	{"GET", "google.com", "/dir", 301, "/dir/"},
   343  	{"GET", "google.com", "/dir/", 200, "/dir/"},
   344  	{"GET", "google.com", "/dir/file", 200, "/dir/"},
   345  	{"GET", "google.com", "/search", 201, "/search"},
   346  	{"GET", "google.com", "/search/", 404, ""},
   347  	{"GET", "google.com", "/search/foo", 404, ""},
   348  	{"GET", "codesearch.google.com", "/search", 202, "codesearch.google.com/search"},
   349  	{"GET", "codesearch.google.com", "/search/", 203, "codesearch.google.com/"},
   350  	{"GET", "codesearch.google.com", "/search/foo", 203, "codesearch.google.com/"},
   351  	{"GET", "codesearch.google.com", "/", 203, "codesearch.google.com/"},
   352  	{"GET", "codesearch.google.com:443", "/", 203, "codesearch.google.com/"},
   353  	{"GET", "images.google.com", "/search", 201, "/search"},
   354  	{"GET", "images.google.com", "/search/", 404, ""},
   355  	{"GET", "images.google.com", "/search/foo", 404, ""},
   356  	{"GET", "google.com", "/../search", 301, "/search"},
   357  	{"GET", "google.com", "/dir/..", 301, ""},
   358  	{"GET", "google.com", "/dir/..", 301, ""},
   359  	{"GET", "google.com", "/dir/./file", 301, "/dir/"},
   360  
   361  	// The /foo -> /foo/ redirect applies to CONNECT requests
   362  	// but the path canonicalization does not.
   363  	{"CONNECT", "google.com", "/dir", 301, "/dir/"},
   364  	{"CONNECT", "google.com", "/../search", 404, ""},
   365  	{"CONNECT", "google.com", "/dir/..", 200, "/dir/"},
   366  	{"CONNECT", "google.com", "/dir/..", 200, "/dir/"},
   367  	{"CONNECT", "google.com", "/dir/./file", 200, "/dir/"},
   368  }
   369  
   370  func TestServeMuxHandler(t *testing.T) {
   371  	setParallel(t)
   372  	mux := NewServeMux()
   373  	for _, e := range serveMuxRegister {
   374  		mux.Handle(e.pattern, e.h)
   375  	}
   376  
   377  	for _, tt := range serveMuxTests {
   378  		r := &Request{
   379  			Method: tt.method,
   380  			Host:   tt.host,
   381  			URL: &url.URL{
   382  				Path: tt.path,
   383  			},
   384  		}
   385  		h, pattern := mux.Handler(r)
   386  		rr := httptest.NewRecorder()
   387  		h.ServeHTTP(rr, r)
   388  		if pattern != tt.pattern || rr.Code != tt.code {
   389  			t.Errorf("%s %s %s = %d, %q, want %d, %q", tt.method, tt.host, tt.path, rr.Code, pattern, tt.code, tt.pattern)
   390  		}
   391  	}
   392  }
   393  
   394  // Issue 24297
   395  func TestServeMuxHandleFuncWithNilHandler(t *testing.T) {
   396  	setParallel(t)
   397  	defer func() {
   398  		if err := recover(); err == nil {
   399  			t.Error("expected call to mux.HandleFunc to panic")
   400  		}
   401  	}()
   402  	mux := NewServeMux()
   403  	mux.HandleFunc("/", nil)
   404  }
   405  
   406  var serveMuxTests2 = []struct {
   407  	method  string
   408  	host    string
   409  	url     string
   410  	code    int
   411  	redirOk bool
   412  }{
   413  	{"GET", "google.com", "/", 404, false},
   414  	{"GET", "example.com", "/test/?example.com/test/", 200, false},
   415  	{"GET", "example.com", "test/?example.com/test/", 200, true},
   416  }
   417  
   418  // TestServeMuxHandlerRedirects tests that automatic redirects generated by
   419  // mux.Handler() shouldn't clear the request's query string.
   420  func TestServeMuxHandlerRedirects(t *testing.T) {
   421  	setParallel(t)
   422  	mux := NewServeMux()
   423  	for _, e := range serveMuxRegister {
   424  		mux.Handle(e.pattern, e.h)
   425  	}
   426  
   427  	for _, tt := range serveMuxTests2 {
   428  		tries := 1 // expect at most 1 redirection if redirOk is true.
   429  		turl := tt.url
   430  		for {
   431  			u, e := url.Parse(turl)
   432  			if e != nil {
   433  				t.Fatal(e)
   434  			}
   435  			r := &Request{
   436  				Method: tt.method,
   437  				Host:   tt.host,
   438  				URL:    u,
   439  			}
   440  			h, _ := mux.Handler(r)
   441  			rr := httptest.NewRecorder()
   442  			h.ServeHTTP(rr, r)
   443  			if rr.Code != 301 {
   444  				if rr.Code != tt.code {
   445  					t.Errorf("%s %s %s = %d, want %d", tt.method, tt.host, tt.url, rr.Code, tt.code)
   446  				}
   447  				break
   448  			}
   449  			if !tt.redirOk {
   450  				t.Errorf("%s %s %s, unexpected redirect", tt.method, tt.host, tt.url)
   451  				break
   452  			}
   453  			turl = rr.HeaderMap.Get("Location")
   454  			tries--
   455  		}
   456  		if tries < 0 {
   457  			t.Errorf("%s %s %s, too many redirects", tt.method, tt.host, tt.url)
   458  		}
   459  	}
   460  }
   461  
   462  // Tests for https://golang.org/issue/900
   463  func TestMuxRedirectLeadingSlashes(t *testing.T) {
   464  	setParallel(t)
   465  	paths := []string{"//foo.txt", "///foo.txt", "/../../foo.txt"}
   466  	for _, path := range paths {
   467  		req, err := ReadRequest(bufio.NewReader(strings.NewReader("GET " + path + " HTTP/1.1\r\nHost: test\r\n\r\n")))
   468  		if err != nil {
   469  			t.Errorf("%s", err)
   470  		}
   471  		mux := NewServeMux()
   472  		resp := httptest.NewRecorder()
   473  
   474  		mux.ServeHTTP(resp, req)
   475  
   476  		if loc, expected := resp.Header().Get("Location"), "/foo.txt"; loc != expected {
   477  			t.Errorf("Expected Location header set to %q; got %q", expected, loc)
   478  			return
   479  		}
   480  
   481  		if code, expected := resp.Code, StatusMovedPermanently; code != expected {
   482  			t.Errorf("Expected response code of StatusMovedPermanently; got %d", code)
   483  			return
   484  		}
   485  	}
   486  }
   487  
   488  // Test that the special cased "/route" redirect
   489  // implicitly created by a registered "/route/"
   490  // properly sets the query string in the redirect URL.
   491  // See Issue 17841.
   492  func TestServeWithSlashRedirectKeepsQueryString(t *testing.T) {
   493  	run(t, testServeWithSlashRedirectKeepsQueryString, []testMode{http1Mode})
   494  }
   495  func testServeWithSlashRedirectKeepsQueryString(t *testing.T, mode testMode) {
   496  	writeBackQuery := func(w ResponseWriter, r *Request) {
   497  		fmt.Fprintf(w, "%s", r.URL.RawQuery)
   498  	}
   499  
   500  	mux := NewServeMux()
   501  	mux.HandleFunc("/testOne", writeBackQuery)
   502  	mux.HandleFunc("/testTwo/", writeBackQuery)
   503  	mux.HandleFunc("/testThree", writeBackQuery)
   504  	mux.HandleFunc("/testThree/", func(w ResponseWriter, r *Request) {
   505  		fmt.Fprintf(w, "%s:bar", r.URL.RawQuery)
   506  	})
   507  
   508  	ts := newClientServerTest(t, mode, mux).ts
   509  
   510  	tests := [...]struct {
   511  		path     string
   512  		method   string
   513  		want     string
   514  		statusOk bool
   515  	}{
   516  		0: {"/testOne?this=that", "GET", "this=that", true},
   517  		1: {"/testTwo?foo=bar", "GET", "foo=bar", true},
   518  		2: {"/testTwo?a=1&b=2&a=3", "GET", "a=1&b=2&a=3", true},
   519  		3: {"/testTwo?", "GET", "", true},
   520  		4: {"/testThree?foo", "GET", "foo", true},
   521  		5: {"/testThree/?foo", "GET", "foo:bar", true},
   522  		6: {"/testThree?foo", "CONNECT", "foo", true},
   523  		7: {"/testThree/?foo", "CONNECT", "foo:bar", true},
   524  
   525  		// canonicalization or not
   526  		8: {"/testOne/foo/..?foo", "GET", "foo", true},
   527  		9: {"/testOne/foo/..?foo", "CONNECT", "404 page not found\n", false},
   528  	}
   529  
   530  	for i, tt := range tests {
   531  		req, _ := NewRequest(tt.method, ts.URL+tt.path, nil)
   532  		res, err := ts.Client().Do(req)
   533  		if err != nil {
   534  			continue
   535  		}
   536  		slurp, _ := io.ReadAll(res.Body)
   537  		res.Body.Close()
   538  		if !tt.statusOk {
   539  			if got, want := res.StatusCode, 404; got != want {
   540  				t.Errorf("#%d: Status = %d; want = %d", i, got, want)
   541  			}
   542  		}
   543  		if got, want := string(slurp), tt.want; got != want {
   544  			t.Errorf("#%d: Body = %q; want = %q", i, got, want)
   545  		}
   546  	}
   547  }
   548  
   549  func TestServeWithSlashRedirectForHostPatterns(t *testing.T) {
   550  	setParallel(t)
   551  
   552  	mux := NewServeMux()
   553  	mux.Handle("example.com/pkg/foo/", stringHandler("example.com/pkg/foo/"))
   554  	mux.Handle("example.com/pkg/bar", stringHandler("example.com/pkg/bar"))
   555  	mux.Handle("example.com/pkg/bar/", stringHandler("example.com/pkg/bar/"))
   556  	mux.Handle("example.com:3000/pkg/connect/", stringHandler("example.com:3000/pkg/connect/"))
   557  	mux.Handle("example.com:9000/", stringHandler("example.com:9000/"))
   558  	mux.Handle("/pkg/baz/", stringHandler("/pkg/baz/"))
   559  
   560  	tests := []struct {
   561  		method string
   562  		url    string
   563  		code   int
   564  		loc    string
   565  		want   string
   566  	}{
   567  		{"GET", "http://example.com/", 404, "", ""},
   568  		{"GET", "http://example.com/pkg/foo", 301, "/pkg/foo/", ""},
   569  		{"GET", "http://example.com/pkg/bar", 200, "", "example.com/pkg/bar"},
   570  		{"GET", "http://example.com/pkg/bar/", 200, "", "example.com/pkg/bar/"},
   571  		{"GET", "http://example.com/pkg/baz", 301, "/pkg/baz/", ""},
   572  		{"GET", "http://example.com:3000/pkg/foo", 301, "/pkg/foo/", ""},
   573  		{"CONNECT", "http://example.com/", 404, "", ""},
   574  		{"CONNECT", "http://example.com:3000/", 404, "", ""},
   575  		{"CONNECT", "http://example.com:9000/", 200, "", "example.com:9000/"},
   576  		{"CONNECT", "http://example.com/pkg/foo", 301, "/pkg/foo/", ""},
   577  		{"CONNECT", "http://example.com:3000/pkg/foo", 404, "", ""},
   578  		{"CONNECT", "http://example.com:3000/pkg/baz", 301, "/pkg/baz/", ""},
   579  		{"CONNECT", "http://example.com:3000/pkg/connect", 301, "/pkg/connect/", ""},
   580  	}
   581  
   582  	for i, tt := range tests {
   583  		req, _ := NewRequest(tt.method, tt.url, nil)
   584  		w := httptest.NewRecorder()
   585  		mux.ServeHTTP(w, req)
   586  
   587  		if got, want := w.Code, tt.code; got != want {
   588  			t.Errorf("#%d: Status = %d; want = %d", i, got, want)
   589  		}
   590  
   591  		if tt.code == 301 {
   592  			if got, want := w.HeaderMap.Get("Location"), tt.loc; got != want {
   593  				t.Errorf("#%d: Location = %q; want = %q", i, got, want)
   594  			}
   595  		} else {
   596  			if got, want := w.HeaderMap.Get("Result"), tt.want; got != want {
   597  				t.Errorf("#%d: Result = %q; want = %q", i, got, want)
   598  			}
   599  		}
   600  	}
   601  }
   602  
   603  // Test that we don't attempt trailing-slash redirect on a path that already has
   604  // a trailing slash.
   605  // See issue #65624.
   606  func TestMuxNoSlashRedirectWithTrailingSlash(t *testing.T) {
   607  	mux := NewServeMux()
   608  	mux.HandleFunc("/{x}/", func(w ResponseWriter, r *Request) {
   609  		fmt.Fprintln(w, "ok")
   610  	})
   611  	w := httptest.NewRecorder()
   612  	req, _ := NewRequest("GET", "/", nil)
   613  	mux.ServeHTTP(w, req)
   614  	if g, w := w.Code, 404; g != w {
   615  		t.Errorf("got %d, want %d", g, w)
   616  	}
   617  }
   618  
   619  // Test that we don't attempt trailing-slash response 405 on a path that already has
   620  // a trailing slash.
   621  // See issue #67657.
   622  func TestMuxNoSlash405WithTrailingSlash(t *testing.T) {
   623  	mux := NewServeMux()
   624  	mux.HandleFunc("GET /{x}/", func(w ResponseWriter, r *Request) {
   625  		fmt.Fprintln(w, "ok")
   626  	})
   627  	w := httptest.NewRecorder()
   628  	req, _ := NewRequest("GET", "/", nil)
   629  	mux.ServeHTTP(w, req)
   630  	if g, w := w.Code, 404; g != w {
   631  		t.Errorf("got %d, want %d", g, w)
   632  	}
   633  }
   634  
   635  func TestShouldRedirectConcurrency(t *testing.T) { run(t, testShouldRedirectConcurrency) }
   636  func testShouldRedirectConcurrency(t *testing.T, mode testMode) {
   637  	mux := NewServeMux()
   638  	newClientServerTest(t, mode, mux)
   639  	mux.HandleFunc("/", func(w ResponseWriter, r *Request) {})
   640  }
   641  
   642  func BenchmarkServeMux(b *testing.B)           { benchmarkServeMux(b, true) }
   643  func BenchmarkServeMux_SkipServe(b *testing.B) { benchmarkServeMux(b, false) }
   644  func benchmarkServeMux(b *testing.B, runHandler bool) {
   645  	type test struct {
   646  		path string
   647  		code int
   648  		req  *Request
   649  	}
   650  
   651  	// Build example handlers and requests
   652  	var tests []test
   653  	endpoints := []string{"search", "dir", "file", "change", "count", "s"}
   654  	for _, e := range endpoints {
   655  		for i := 200; i < 230; i++ {
   656  			p := fmt.Sprintf("/%s/%d/", e, i)
   657  			tests = append(tests, test{
   658  				path: p,
   659  				code: i,
   660  				req:  &Request{Method: "GET", Host: "localhost", URL: &url.URL{Path: p}},
   661  			})
   662  		}
   663  	}
   664  	mux := NewServeMux()
   665  	for _, tt := range tests {
   666  		mux.Handle(tt.path, serve(tt.code))
   667  	}
   668  
   669  	rw := httptest.NewRecorder()
   670  	b.ReportAllocs()
   671  	b.ResetTimer()
   672  	for i := 0; i < b.N; i++ {
   673  		for _, tt := range tests {
   674  			*rw = httptest.ResponseRecorder{}
   675  			h, pattern := mux.Handler(tt.req)
   676  			if runHandler {
   677  				h.ServeHTTP(rw, tt.req)
   678  				if pattern != tt.path || rw.Code != tt.code {
   679  					b.Fatalf("got %d, %q, want %d, %q", rw.Code, pattern, tt.code, tt.path)
   680  				}
   681  			}
   682  		}
   683  	}
   684  }
   685  
   686  func TestServerTimeouts(t *testing.T) { run(t, testServerTimeouts, []testMode{http1Mode}) }
   687  func testServerTimeouts(t *testing.T, mode testMode) {
   688  	runTimeSensitiveTest(t, []time.Duration{
   689  		10 * time.Millisecond,
   690  		50 * time.Millisecond,
   691  		100 * time.Millisecond,
   692  		500 * time.Millisecond,
   693  		1 * time.Second,
   694  	}, func(t *testing.T, timeout time.Duration) error {
   695  		return testServerTimeoutsWithTimeout(t, timeout, mode)
   696  	})
   697  }
   698  
   699  func testServerTimeoutsWithTimeout(t *testing.T, timeout time.Duration, mode testMode) error {
   700  	var reqNum atomic.Int32
   701  	cst := newClientServerTest(t, mode, HandlerFunc(func(res ResponseWriter, req *Request) {
   702  		fmt.Fprintf(res, "req=%d", reqNum.Add(1))
   703  	}), func(ts *httptest.Server) {
   704  		ts.Config.ReadTimeout = timeout
   705  		ts.Config.WriteTimeout = timeout
   706  	})
   707  	defer cst.close()
   708  	ts := cst.ts
   709  
   710  	// Hit the HTTP server successfully.
   711  	c := ts.Client()
   712  	r, err := c.Get(ts.URL)
   713  	if err != nil {
   714  		return fmt.Errorf("http Get #1: %v", err)
   715  	}
   716  	got, err := io.ReadAll(r.Body)
   717  	expected := "req=1"
   718  	if string(got) != expected || err != nil {
   719  		return fmt.Errorf("Unexpected response for request #1; got %q ,%v; expected %q, nil",
   720  			string(got), err, expected)
   721  	}
   722  
   723  	// Slow client that should timeout.
   724  	t1 := time.Now()
   725  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
   726  	if err != nil {
   727  		return fmt.Errorf("Dial: %v", err)
   728  	}
   729  	buf := make([]byte, 1)
   730  	n, err := conn.Read(buf)
   731  	conn.Close()
   732  	latency := time.Since(t1)
   733  	if n != 0 || err != io.EOF {
   734  		return fmt.Errorf("Read = %v, %v, wanted %v, %v", n, err, 0, io.EOF)
   735  	}
   736  	minLatency := timeout / 5 * 4
   737  	if latency < minLatency {
   738  		return fmt.Errorf("got EOF after %s, want >= %s", latency, minLatency)
   739  	}
   740  
   741  	// Hit the HTTP server successfully again, verifying that the
   742  	// previous slow connection didn't run our handler.  (that we
   743  	// get "req=2", not "req=3")
   744  	r, err = c.Get(ts.URL)
   745  	if err != nil {
   746  		return fmt.Errorf("http Get #2: %v", err)
   747  	}
   748  	got, err = io.ReadAll(r.Body)
   749  	r.Body.Close()
   750  	expected = "req=2"
   751  	if string(got) != expected || err != nil {
   752  		return fmt.Errorf("Get #2 got %q, %v, want %q, nil", string(got), err, expected)
   753  	}
   754  
   755  	if !testing.Short() {
   756  		conn, err := net.Dial("tcp", ts.Listener.Addr().String())
   757  		if err != nil {
   758  			return fmt.Errorf("long Dial: %v", err)
   759  		}
   760  		defer conn.Close()
   761  		go io.Copy(io.Discard, conn)
   762  		for i := 0; i < 5; i++ {
   763  			_, err := conn.Write([]byte("GET / HTTP/1.1\r\nHost: foo\r\n\r\n"))
   764  			if err != nil {
   765  				return fmt.Errorf("on write %d: %v", i, err)
   766  			}
   767  			time.Sleep(timeout / 2)
   768  		}
   769  	}
   770  	return nil
   771  }
   772  
   773  func TestServerReadTimeout(t *testing.T) { run(t, testServerReadTimeout) }
   774  func testServerReadTimeout(t *testing.T, mode testMode) {
   775  	respBody := "response body"
   776  	for timeout := 5 * time.Millisecond; ; timeout *= 2 {
   777  		cst := newClientServerTest(t, mode, HandlerFunc(func(res ResponseWriter, req *Request) {
   778  			_, err := io.Copy(io.Discard, req.Body)
   779  			if !errors.Is(err, os.ErrDeadlineExceeded) {
   780  				t.Errorf("server timed out reading request body: got err %v; want os.ErrDeadlineExceeded", err)
   781  			}
   782  			res.Write([]byte(respBody))
   783  		}), func(ts *httptest.Server) {
   784  			ts.Config.ReadHeaderTimeout = -1 // don't time out while reading headers
   785  			ts.Config.ReadTimeout = timeout
   786  			t.Logf("Server.Config.ReadTimeout = %v", timeout)
   787  		})
   788  
   789  		var retries atomic.Int32
   790  		cst.c.Transport.(*Transport).Proxy = func(*Request) (*url.URL, error) {
   791  			if retries.Add(1) != 1 {
   792  				return nil, errors.New("too many retries")
   793  			}
   794  			return nil, nil
   795  		}
   796  
   797  		pr, pw := io.Pipe()
   798  		res, err := cst.c.Post(cst.ts.URL, "text/apocryphal", pr)
   799  		if err != nil {
   800  			t.Logf("Get error, retrying: %v", err)
   801  			cst.close()
   802  			continue
   803  		}
   804  		defer res.Body.Close()
   805  		got, err := io.ReadAll(res.Body)
   806  		if string(got) != respBody || err != nil {
   807  			t.Errorf("client read response body: %q, %v; want %q, nil", string(got), err, respBody)
   808  		}
   809  		pw.Close()
   810  		break
   811  	}
   812  }
   813  
   814  func TestServerNoReadTimeout(t *testing.T) { run(t, testServerNoReadTimeout) }
   815  func testServerNoReadTimeout(t *testing.T, mode testMode) {
   816  	reqBody := "Hello, Gophers!"
   817  	resBody := "Hi, Gophers!"
   818  	for _, timeout := range []time.Duration{0, -1} {
   819  		cst := newClientServerTest(t, mode, HandlerFunc(func(res ResponseWriter, req *Request) {
   820  			ctl := NewResponseController(res)
   821  			ctl.EnableFullDuplex()
   822  			res.WriteHeader(StatusOK)
   823  			// Flush the headers before processing the request body
   824  			// to unblock the client from the RoundTrip.
   825  			if err := ctl.Flush(); err != nil {
   826  				t.Errorf("server flush response: %v", err)
   827  				return
   828  			}
   829  			got, err := io.ReadAll(req.Body)
   830  			if string(got) != reqBody || err != nil {
   831  				t.Errorf("server read request body: %v; got %q, want %q", err, got, reqBody)
   832  			}
   833  			res.Write([]byte(resBody))
   834  		}), func(ts *httptest.Server) {
   835  			ts.Config.ReadTimeout = timeout
   836  			t.Logf("Server.Config.ReadTimeout = %d", timeout)
   837  		})
   838  
   839  		pr, pw := io.Pipe()
   840  		res, err := cst.c.Post(cst.ts.URL, "text/plain", pr)
   841  		if err != nil {
   842  			t.Fatal(err)
   843  		}
   844  		defer res.Body.Close()
   845  
   846  		// TODO(panjf2000): sleep is not so robust, maybe find a better way to test this?
   847  		time.Sleep(10 * time.Millisecond) // stall sending body to server to test server doesn't time out
   848  		pw.Write([]byte(reqBody))
   849  		pw.Close()
   850  
   851  		got, err := io.ReadAll(res.Body)
   852  		if string(got) != resBody || err != nil {
   853  			t.Errorf("client read response body: %v; got %v, want %q", err, got, resBody)
   854  		}
   855  	}
   856  }
   857  
   858  func TestServerWriteTimeout(t *testing.T) { run(t, testServerWriteTimeout) }
   859  func testServerWriteTimeout(t *testing.T, mode testMode) {
   860  	for timeout := 5 * time.Millisecond; ; timeout *= 2 {
   861  		errc := make(chan error, 2)
   862  		cst := newClientServerTest(t, mode, HandlerFunc(func(res ResponseWriter, req *Request) {
   863  			errc <- nil
   864  			_, err := io.Copy(res, neverEnding('a'))
   865  			errc <- err
   866  		}), func(ts *httptest.Server) {
   867  			ts.Config.WriteTimeout = timeout
   868  			t.Logf("Server.Config.WriteTimeout = %v", timeout)
   869  		})
   870  
   871  		// The server's WriteTimeout parameter also applies to reads during the TLS
   872  		// handshake. The client makes the last write during the handshake, and if
   873  		// the server happens to time out during the read of that write, the client
   874  		// may think that the connection was accepted even though the server thinks
   875  		// it timed out.
   876  		//
   877  		// The client only notices that the server connection is gone when it goes
   878  		// to actually write the request — and when that fails, it retries
   879  		// internally (the same as if the server had closed the connection due to a
   880  		// racing idle-timeout).
   881  		//
   882  		// With unlucky and very stable scheduling (as may be the case with the fake wasm
   883  		// net stack), this can result in an infinite retry loop that doesn't
   884  		// propagate the error up far enough for us to adjust the WriteTimeout.
   885  		//
   886  		// To avoid that problem, we explicitly forbid internal retries by rejecting
   887  		// them in a Proxy hook in the transport.
   888  		var retries atomic.Int32
   889  		cst.c.Transport.(*Transport).Proxy = func(*Request) (*url.URL, error) {
   890  			if retries.Add(1) != 1 {
   891  				return nil, errors.New("too many retries")
   892  			}
   893  			return nil, nil
   894  		}
   895  
   896  		res, err := cst.c.Get(cst.ts.URL)
   897  		if err != nil {
   898  			// Probably caused by the write timeout expiring before the handler runs.
   899  			t.Logf("Get error, retrying: %v", err)
   900  			cst.close()
   901  			continue
   902  		}
   903  		defer res.Body.Close()
   904  		_, err = io.Copy(io.Discard, res.Body)
   905  		if err == nil {
   906  			t.Errorf("client reading from truncated request body: got nil error, want non-nil")
   907  		}
   908  		select {
   909  		case <-errc:
   910  			err = <-errc // io.Copy error
   911  			if !errors.Is(err, os.ErrDeadlineExceeded) {
   912  				t.Errorf("server timed out writing request body: got err %v; want os.ErrDeadlineExceeded", err)
   913  			}
   914  			return
   915  		default:
   916  			// The write timeout expired before the handler started.
   917  			t.Logf("handler didn't run, retrying")
   918  			cst.close()
   919  		}
   920  	}
   921  }
   922  
   923  func TestServerNoWriteTimeout(t *testing.T) { run(t, testServerNoWriteTimeout) }
   924  func testServerNoWriteTimeout(t *testing.T, mode testMode) {
   925  	for _, timeout := range []time.Duration{0, -1} {
   926  		cst := newClientServerTest(t, mode, HandlerFunc(func(res ResponseWriter, req *Request) {
   927  			_, err := io.Copy(res, neverEnding('a'))
   928  			t.Logf("server write response: %v", err)
   929  		}), func(ts *httptest.Server) {
   930  			ts.Config.WriteTimeout = timeout
   931  			t.Logf("Server.Config.WriteTimeout = %d", timeout)
   932  		})
   933  
   934  		res, err := cst.c.Get(cst.ts.URL)
   935  		if err != nil {
   936  			t.Fatal(err)
   937  		}
   938  		defer res.Body.Close()
   939  		n, err := io.CopyN(io.Discard, res.Body, 1<<20) // 1MB should be sufficient to prove the point
   940  		if n != 1<<20 || err != nil {
   941  			t.Errorf("client read response body: %d, %v", n, err)
   942  		}
   943  		// This shutdown really should be automatic, but it isn't right now.
   944  		// Shutdown (rather than Close) ensures the handler is done before we return.
   945  		res.Body.Close()
   946  		cst.ts.Config.Shutdown(context.Background())
   947  	}
   948  }
   949  
   950  // Test that the HTTP/2 server handles Server.WriteTimeout (Issue 18437)
   951  func TestWriteDeadlineExtendedOnNewRequest(t *testing.T) {
   952  	run(t, testWriteDeadlineExtendedOnNewRequest)
   953  }
   954  func testWriteDeadlineExtendedOnNewRequest(t *testing.T, mode testMode) {
   955  	if testing.Short() {
   956  		t.Skip("skipping in short mode")
   957  	}
   958  	ts := newClientServerTest(t, mode, HandlerFunc(func(res ResponseWriter, req *Request) {}),
   959  		func(ts *httptest.Server) {
   960  			ts.Config.WriteTimeout = 250 * time.Millisecond
   961  		},
   962  	).ts
   963  
   964  	c := ts.Client()
   965  
   966  	for i := 1; i <= 3; i++ {
   967  		req, err := NewRequest("GET", ts.URL, nil)
   968  		if err != nil {
   969  			t.Fatal(err)
   970  		}
   971  
   972  		r, err := c.Do(req)
   973  		if err != nil {
   974  			t.Fatalf("http2 Get #%d: %v", i, err)
   975  		}
   976  		r.Body.Close()
   977  		time.Sleep(ts.Config.WriteTimeout / 2)
   978  	}
   979  }
   980  
   981  // tryTimeouts runs testFunc with increasing timeouts. Test passes on first success,
   982  // and fails if all timeouts fail.
   983  func tryTimeouts(t *testing.T, testFunc func(timeout time.Duration) error) {
   984  	tries := []time.Duration{250 * time.Millisecond, 500 * time.Millisecond, 1 * time.Second}
   985  	for i, timeout := range tries {
   986  		err := testFunc(timeout)
   987  		if err == nil {
   988  			return
   989  		}
   990  		t.Logf("failed at %v: %v", timeout, err)
   991  		if i != len(tries)-1 {
   992  			t.Logf("retrying at %v ...", tries[i+1])
   993  		}
   994  	}
   995  	t.Fatal("all attempts failed")
   996  }
   997  
   998  // Test that the HTTP/2 server RSTs stream on slow write.
   999  func TestWriteDeadlineEnforcedPerStream(t *testing.T) {
  1000  	if testing.Short() {
  1001  		t.Skip("skipping in short mode")
  1002  	}
  1003  	setParallel(t)
  1004  	run(t, func(t *testing.T, mode testMode) {
  1005  		tryTimeouts(t, func(timeout time.Duration) error {
  1006  			return testWriteDeadlineEnforcedPerStream(t, mode, timeout)
  1007  		})
  1008  	})
  1009  }
  1010  
  1011  func testWriteDeadlineEnforcedPerStream(t *testing.T, mode testMode, timeout time.Duration) error {
  1012  	firstRequest := make(chan bool, 1)
  1013  	cst := newClientServerTest(t, mode, HandlerFunc(func(res ResponseWriter, req *Request) {
  1014  		select {
  1015  		case firstRequest <- true:
  1016  			// first request succeeds
  1017  		default:
  1018  			// second request times out
  1019  			time.Sleep(timeout)
  1020  		}
  1021  	}), func(ts *httptest.Server) {
  1022  		ts.Config.WriteTimeout = timeout / 2
  1023  	})
  1024  	defer cst.close()
  1025  	ts := cst.ts
  1026  
  1027  	c := ts.Client()
  1028  
  1029  	req, err := NewRequest("GET", ts.URL, nil)
  1030  	if err != nil {
  1031  		return fmt.Errorf("NewRequest: %v", err)
  1032  	}
  1033  	r, err := c.Do(req)
  1034  	if err != nil {
  1035  		return fmt.Errorf("Get #1: %v", err)
  1036  	}
  1037  	r.Body.Close()
  1038  
  1039  	req, err = NewRequest("GET", ts.URL, nil)
  1040  	if err != nil {
  1041  		return fmt.Errorf("NewRequest: %v", err)
  1042  	}
  1043  	r, err = c.Do(req)
  1044  	if err == nil {
  1045  		r.Body.Close()
  1046  		return fmt.Errorf("Get #2 expected error, got nil")
  1047  	}
  1048  	if mode == http2Mode {
  1049  		expected := "stream ID 3; INTERNAL_ERROR" // client IDs are odd, second stream should be 3
  1050  		if !strings.Contains(err.Error(), expected) {
  1051  			return fmt.Errorf("http2 Get #2: expected error to contain %q, got %q", expected, err)
  1052  		}
  1053  	}
  1054  	return nil
  1055  }
  1056  
  1057  // Test that the HTTP/2 server does not send RST when WriteDeadline not set.
  1058  func TestNoWriteDeadline(t *testing.T) {
  1059  	if testing.Short() {
  1060  		t.Skip("skipping in short mode")
  1061  	}
  1062  	setParallel(t)
  1063  	defer afterTest(t)
  1064  	run(t, func(t *testing.T, mode testMode) {
  1065  		tryTimeouts(t, func(timeout time.Duration) error {
  1066  			return testNoWriteDeadline(t, mode, timeout)
  1067  		})
  1068  	})
  1069  }
  1070  
  1071  func testNoWriteDeadline(t *testing.T, mode testMode, timeout time.Duration) error {
  1072  	firstRequest := make(chan bool, 1)
  1073  	cst := newClientServerTest(t, mode, HandlerFunc(func(res ResponseWriter, req *Request) {
  1074  		select {
  1075  		case firstRequest <- true:
  1076  			// first request succeeds
  1077  		default:
  1078  			// second request times out
  1079  			time.Sleep(timeout)
  1080  		}
  1081  	}))
  1082  	defer cst.close()
  1083  	ts := cst.ts
  1084  
  1085  	c := ts.Client()
  1086  
  1087  	for i := 0; i < 2; i++ {
  1088  		req, err := NewRequest("GET", ts.URL, nil)
  1089  		if err != nil {
  1090  			return fmt.Errorf("NewRequest: %v", err)
  1091  		}
  1092  		r, err := c.Do(req)
  1093  		if err != nil {
  1094  			return fmt.Errorf("Get #%d: %v", i, err)
  1095  		}
  1096  		r.Body.Close()
  1097  	}
  1098  	return nil
  1099  }
  1100  
  1101  // golang.org/issue/4741 -- setting only a write timeout that triggers
  1102  // shouldn't cause a handler to block forever on reads (next HTTP
  1103  // request) that will never happen.
  1104  func TestOnlyWriteTimeout(t *testing.T) { run(t, testOnlyWriteTimeout, []testMode{http1Mode}) }
  1105  func testOnlyWriteTimeout(t *testing.T, mode testMode) {
  1106  	var (
  1107  		mu   sync.RWMutex
  1108  		conn net.Conn
  1109  	)
  1110  	var afterTimeoutErrc = make(chan error, 1)
  1111  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, req *Request) {
  1112  		buf := make([]byte, 512<<10)
  1113  		_, err := w.Write(buf)
  1114  		if err != nil {
  1115  			t.Errorf("handler Write error: %v", err)
  1116  			return
  1117  		}
  1118  		mu.RLock()
  1119  		defer mu.RUnlock()
  1120  		if conn == nil {
  1121  			t.Error("no established connection found")
  1122  			return
  1123  		}
  1124  		conn.SetWriteDeadline(time.Now().Add(-30 * time.Second))
  1125  		_, err = w.Write(buf)
  1126  		afterTimeoutErrc <- err
  1127  	}), func(ts *httptest.Server) {
  1128  		ts.Listener = trackLastConnListener{ts.Listener, &mu, &conn}
  1129  	}).ts
  1130  
  1131  	c := ts.Client()
  1132  
  1133  	err := func() error {
  1134  		res, err := c.Get(ts.URL)
  1135  		if err != nil {
  1136  			return err
  1137  		}
  1138  		_, err = io.Copy(io.Discard, res.Body)
  1139  		res.Body.Close()
  1140  		return err
  1141  	}()
  1142  	if err == nil {
  1143  		t.Errorf("expected an error copying body from Get request")
  1144  	}
  1145  
  1146  	if err := <-afterTimeoutErrc; err == nil {
  1147  		t.Error("expected write error after timeout")
  1148  	}
  1149  }
  1150  
  1151  // trackLastConnListener tracks the last net.Conn that was accepted.
  1152  type trackLastConnListener struct {
  1153  	net.Listener
  1154  
  1155  	mu   *sync.RWMutex
  1156  	last *net.Conn // destination
  1157  }
  1158  
  1159  func (l trackLastConnListener) Accept() (c net.Conn, err error) {
  1160  	c, err = l.Listener.Accept()
  1161  	if err == nil {
  1162  		l.mu.Lock()
  1163  		*l.last = c
  1164  		l.mu.Unlock()
  1165  	}
  1166  	return
  1167  }
  1168  
  1169  // TestIdentityResponse verifies that a handler can unset
  1170  func TestIdentityResponse(t *testing.T) { run(t, testIdentityResponse) }
  1171  func testIdentityResponse(t *testing.T, mode testMode) {
  1172  	if mode == http2Mode {
  1173  		t.Skip("https://go.dev/issue/56019")
  1174  	}
  1175  
  1176  	handler := HandlerFunc(func(rw ResponseWriter, req *Request) {
  1177  		rw.Header().Set("Content-Length", "3")
  1178  		rw.Header().Set("Transfer-Encoding", req.FormValue("te"))
  1179  		switch {
  1180  		case req.FormValue("overwrite") == "1":
  1181  			_, err := rw.Write([]byte("foo TOO LONG"))
  1182  			if err != ErrContentLength {
  1183  				t.Errorf("expected ErrContentLength; got %v", err)
  1184  			}
  1185  		case req.FormValue("underwrite") == "1":
  1186  			rw.Header().Set("Content-Length", "500")
  1187  			rw.Write([]byte("too short"))
  1188  		default:
  1189  			rw.Write([]byte("foo"))
  1190  		}
  1191  	})
  1192  
  1193  	ts := newClientServerTest(t, mode, handler).ts
  1194  	c := ts.Client()
  1195  
  1196  	// Note: this relies on the assumption (which is true) that
  1197  	// Get sends HTTP/1.1 or greater requests. Otherwise the
  1198  	// server wouldn't have the choice to send back chunked
  1199  	// responses.
  1200  	for _, te := range []string{"", "identity"} {
  1201  		url := ts.URL + "/?te=" + te
  1202  		res, err := c.Get(url)
  1203  		if err != nil {
  1204  			t.Fatalf("error with Get of %s: %v", url, err)
  1205  		}
  1206  		if cl, expected := res.ContentLength, int64(3); cl != expected {
  1207  			t.Errorf("for %s expected res.ContentLength of %d; got %d", url, expected, cl)
  1208  		}
  1209  		if cl, expected := res.Header.Get("Content-Length"), "3"; cl != expected {
  1210  			t.Errorf("for %s expected Content-Length header of %q; got %q", url, expected, cl)
  1211  		}
  1212  		if tl, expected := len(res.TransferEncoding), 0; tl != expected {
  1213  			t.Errorf("for %s expected len(res.TransferEncoding) of %d; got %d (%v)",
  1214  				url, expected, tl, res.TransferEncoding)
  1215  		}
  1216  		res.Body.Close()
  1217  	}
  1218  
  1219  	// Verify that ErrContentLength is returned
  1220  	url := ts.URL + "/?overwrite=1"
  1221  	res, err := c.Get(url)
  1222  	if err != nil {
  1223  		t.Fatalf("error with Get of %s: %v", url, err)
  1224  	}
  1225  	res.Body.Close()
  1226  
  1227  	if mode != http1Mode {
  1228  		return
  1229  	}
  1230  
  1231  	// Verify that the connection is closed when the declared Content-Length
  1232  	// is larger than what the handler wrote.
  1233  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  1234  	if err != nil {
  1235  		t.Fatalf("error dialing: %v", err)
  1236  	}
  1237  	_, err = conn.Write([]byte("GET /?underwrite=1 HTTP/1.1\r\nHost: foo\r\n\r\n"))
  1238  	if err != nil {
  1239  		t.Fatalf("error writing: %v", err)
  1240  	}
  1241  
  1242  	// The ReadAll will hang for a failing test.
  1243  	got, _ := io.ReadAll(conn)
  1244  	expectedSuffix := "\r\n\r\ntoo short"
  1245  	if !strings.HasSuffix(string(got), expectedSuffix) {
  1246  		t.Errorf("Expected output to end with %q; got response body %q",
  1247  			expectedSuffix, string(got))
  1248  	}
  1249  }
  1250  
  1251  func testTCPConnectionCloses(t *testing.T, req string, h Handler) {
  1252  	setParallel(t)
  1253  	s := newClientServerTest(t, http1Mode, h).ts
  1254  
  1255  	conn, err := net.Dial("tcp", s.Listener.Addr().String())
  1256  	if err != nil {
  1257  		t.Fatal("dial error:", err)
  1258  	}
  1259  	defer conn.Close()
  1260  
  1261  	_, err = fmt.Fprint(conn, req)
  1262  	if err != nil {
  1263  		t.Fatal("print error:", err)
  1264  	}
  1265  
  1266  	r := bufio.NewReader(conn)
  1267  	res, err := ReadResponse(r, &Request{Method: "GET"})
  1268  	if err != nil {
  1269  		t.Fatal("ReadResponse error:", err)
  1270  	}
  1271  
  1272  	_, err = io.ReadAll(r)
  1273  	if err != nil {
  1274  		t.Fatal("read error:", err)
  1275  	}
  1276  
  1277  	if !res.Close {
  1278  		t.Errorf("Response.Close = false; want true")
  1279  	}
  1280  }
  1281  
  1282  func testTCPConnectionStaysOpen(t *testing.T, req string, handler Handler) {
  1283  	setParallel(t)
  1284  	ts := newClientServerTest(t, http1Mode, handler).ts
  1285  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  1286  	if err != nil {
  1287  		t.Fatal(err)
  1288  	}
  1289  	defer conn.Close()
  1290  	br := bufio.NewReader(conn)
  1291  	for i := 0; i < 2; i++ {
  1292  		if _, err := io.WriteString(conn, req); err != nil {
  1293  			t.Fatal(err)
  1294  		}
  1295  		res, err := ReadResponse(br, nil)
  1296  		if err != nil {
  1297  			t.Fatalf("res %d: %v", i+1, err)
  1298  		}
  1299  		if _, err := io.Copy(io.Discard, res.Body); err != nil {
  1300  			t.Fatalf("res %d body copy: %v", i+1, err)
  1301  		}
  1302  		res.Body.Close()
  1303  	}
  1304  }
  1305  
  1306  // TestServeHTTP10Close verifies that HTTP/1.0 requests won't be kept alive.
  1307  func TestServeHTTP10Close(t *testing.T) {
  1308  	testTCPConnectionCloses(t, "GET / HTTP/1.0\r\n\r\n", HandlerFunc(func(w ResponseWriter, r *Request) {
  1309  		ServeFile(w, r, "testdata/file")
  1310  	}))
  1311  }
  1312  
  1313  // TestClientCanClose verifies that clients can also force a connection to close.
  1314  func TestClientCanClose(t *testing.T) {
  1315  	testTCPConnectionCloses(t, "GET / HTTP/1.1\r\nHost: foo\r\nConnection: close\r\n\r\n", HandlerFunc(func(w ResponseWriter, r *Request) {
  1316  		// Nothing.
  1317  	}))
  1318  }
  1319  
  1320  // TestHandlersCanSetConnectionClose verifies that handlers can force a connection to close,
  1321  // even for HTTP/1.1 requests.
  1322  func TestHandlersCanSetConnectionClose11(t *testing.T) {
  1323  	testTCPConnectionCloses(t, "GET / HTTP/1.1\r\nHost: foo\r\n\r\n\r\n", HandlerFunc(func(w ResponseWriter, r *Request) {
  1324  		w.Header().Set("Connection", "close")
  1325  	}))
  1326  }
  1327  
  1328  func TestHandlersCanSetConnectionClose10(t *testing.T) {
  1329  	testTCPConnectionCloses(t, "GET / HTTP/1.0\r\nConnection: keep-alive\r\n\r\n", HandlerFunc(func(w ResponseWriter, r *Request) {
  1330  		w.Header().Set("Connection", "close")
  1331  	}))
  1332  }
  1333  
  1334  func TestHTTP2UpgradeClosesConnection(t *testing.T) {
  1335  	testTCPConnectionCloses(t, "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n", HandlerFunc(func(w ResponseWriter, r *Request) {
  1336  		// Nothing. (if not hijacked, the server should close the connection
  1337  		// afterwards)
  1338  	}))
  1339  }
  1340  
  1341  func send204(w ResponseWriter, r *Request) { w.WriteHeader(204) }
  1342  func send304(w ResponseWriter, r *Request) { w.WriteHeader(304) }
  1343  
  1344  // Issue 15647: 204 responses can't have bodies, so HTTP/1.0 keep-alive conns should stay open.
  1345  func TestHTTP10KeepAlive204Response(t *testing.T) {
  1346  	testTCPConnectionStaysOpen(t, "GET / HTTP/1.0\r\nConnection: keep-alive\r\n\r\n", HandlerFunc(send204))
  1347  }
  1348  
  1349  func TestHTTP11KeepAlive204Response(t *testing.T) {
  1350  	testTCPConnectionStaysOpen(t, "GET / HTTP/1.1\r\nHost: foo\r\n\r\n", HandlerFunc(send204))
  1351  }
  1352  
  1353  func TestHTTP10KeepAlive304Response(t *testing.T) {
  1354  	testTCPConnectionStaysOpen(t,
  1355  		"GET / HTTP/1.0\r\nConnection: keep-alive\r\nIf-Modified-Since: Mon, 02 Jan 2006 15:04:05 GMT\r\n\r\n",
  1356  		HandlerFunc(send304))
  1357  }
  1358  
  1359  // Issue 15703
  1360  func TestKeepAliveFinalChunkWithEOF(t *testing.T) { run(t, testKeepAliveFinalChunkWithEOF) }
  1361  func testKeepAliveFinalChunkWithEOF(t *testing.T, mode testMode) {
  1362  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  1363  		w.(Flusher).Flush() // force chunked encoding
  1364  		w.Write([]byte("{\"Addr\": \"" + r.RemoteAddr + "\"}"))
  1365  	}))
  1366  	type data struct {
  1367  		Addr string
  1368  	}
  1369  	var addrs [2]data
  1370  	for i := range addrs {
  1371  		res, err := cst.c.Get(cst.ts.URL)
  1372  		if err != nil {
  1373  			t.Fatal(err)
  1374  		}
  1375  		if err := json.NewDecoder(res.Body).Decode(&addrs[i]); err != nil {
  1376  			t.Fatal(err)
  1377  		}
  1378  		if addrs[i].Addr == "" {
  1379  			t.Fatal("no address")
  1380  		}
  1381  		res.Body.Close()
  1382  	}
  1383  	if addrs[0] != addrs[1] {
  1384  		t.Fatalf("connection not reused")
  1385  	}
  1386  }
  1387  
  1388  func TestSetsRemoteAddr(t *testing.T) { run(t, testSetsRemoteAddr) }
  1389  func testSetsRemoteAddr(t *testing.T, mode testMode) {
  1390  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  1391  		fmt.Fprintf(w, "%s", r.RemoteAddr)
  1392  	}))
  1393  
  1394  	res, err := cst.c.Get(cst.ts.URL)
  1395  	if err != nil {
  1396  		t.Fatalf("Get error: %v", err)
  1397  	}
  1398  	body, err := io.ReadAll(res.Body)
  1399  	if err != nil {
  1400  		t.Fatalf("ReadAll error: %v", err)
  1401  	}
  1402  	ip := string(body)
  1403  	if !strings.HasPrefix(ip, "127.0.0.1:") && !strings.HasPrefix(ip, "[::1]:") {
  1404  		t.Fatalf("Expected local addr; got %q", ip)
  1405  	}
  1406  }
  1407  
  1408  type blockingRemoteAddrListener struct {
  1409  	net.Listener
  1410  	conns chan<- net.Conn
  1411  }
  1412  
  1413  func (l *blockingRemoteAddrListener) Accept() (net.Conn, error) {
  1414  	c, err := l.Listener.Accept()
  1415  	if err != nil {
  1416  		return nil, err
  1417  	}
  1418  	brac := &blockingRemoteAddrConn{
  1419  		Conn:  c,
  1420  		addrs: make(chan net.Addr, 1),
  1421  	}
  1422  	l.conns <- brac
  1423  	return brac, nil
  1424  }
  1425  
  1426  type blockingRemoteAddrConn struct {
  1427  	net.Conn
  1428  	addrs chan net.Addr
  1429  }
  1430  
  1431  func (c *blockingRemoteAddrConn) RemoteAddr() net.Addr {
  1432  	return <-c.addrs
  1433  }
  1434  
  1435  // Issue 12943
  1436  func TestServerAllowsBlockingRemoteAddr(t *testing.T) {
  1437  	run(t, testServerAllowsBlockingRemoteAddr, []testMode{http1Mode})
  1438  }
  1439  func testServerAllowsBlockingRemoteAddr(t *testing.T, mode testMode) {
  1440  	conns := make(chan net.Conn)
  1441  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  1442  		fmt.Fprintf(w, "RA:%s", r.RemoteAddr)
  1443  	}), func(ts *httptest.Server) {
  1444  		ts.Listener = &blockingRemoteAddrListener{
  1445  			Listener: ts.Listener,
  1446  			conns:    conns,
  1447  		}
  1448  	}).ts
  1449  
  1450  	c := ts.Client()
  1451  	// Force separate connection for each:
  1452  	c.Transport.(*Transport).DisableKeepAlives = true
  1453  
  1454  	fetch := func(num int, response chan<- string) {
  1455  		resp, err := c.Get(ts.URL)
  1456  		if err != nil {
  1457  			t.Errorf("Request %d: %v", num, err)
  1458  			response <- ""
  1459  			return
  1460  		}
  1461  		defer resp.Body.Close()
  1462  		body, err := io.ReadAll(resp.Body)
  1463  		if err != nil {
  1464  			t.Errorf("Request %d: %v", num, err)
  1465  			response <- ""
  1466  			return
  1467  		}
  1468  		response <- string(body)
  1469  	}
  1470  
  1471  	// Start a request. The server will block on getting conn.RemoteAddr.
  1472  	response1c := make(chan string, 1)
  1473  	go fetch(1, response1c)
  1474  
  1475  	// Wait for the server to accept it; grab the connection.
  1476  	conn1 := <-conns
  1477  
  1478  	// Start another request and grab its connection
  1479  	response2c := make(chan string, 1)
  1480  	go fetch(2, response2c)
  1481  	conn2 := <-conns
  1482  
  1483  	// Send a response on connection 2.
  1484  	conn2.(*blockingRemoteAddrConn).addrs <- &net.TCPAddr{
  1485  		IP: net.ParseIP("12.12.12.12"), Port: 12}
  1486  
  1487  	// ... and see it
  1488  	response2 := <-response2c
  1489  	if g, e := response2, "RA:12.12.12.12:12"; g != e {
  1490  		t.Fatalf("response 2 addr = %q; want %q", g, e)
  1491  	}
  1492  
  1493  	// Finish the first response.
  1494  	conn1.(*blockingRemoteAddrConn).addrs <- &net.TCPAddr{
  1495  		IP: net.ParseIP("21.21.21.21"), Port: 21}
  1496  
  1497  	// ... and see it
  1498  	response1 := <-response1c
  1499  	if g, e := response1, "RA:21.21.21.21:21"; g != e {
  1500  		t.Fatalf("response 1 addr = %q; want %q", g, e)
  1501  	}
  1502  }
  1503  
  1504  // TestHeadResponses verifies that all MIME type sniffing and Content-Length
  1505  // counting of GET requests also happens on HEAD requests.
  1506  func TestHeadResponses(t *testing.T) { run(t, testHeadResponses) }
  1507  func testHeadResponses(t *testing.T, mode testMode) {
  1508  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  1509  		_, err := w.Write([]byte("<html>"))
  1510  		if err != nil {
  1511  			t.Errorf("ResponseWriter.Write: %v", err)
  1512  		}
  1513  
  1514  		// Also exercise the ReaderFrom path
  1515  		_, err = io.Copy(w, struct{ io.Reader }{strings.NewReader("789a")})
  1516  		if err != nil {
  1517  			t.Errorf("Copy(ResponseWriter, ...): %v", err)
  1518  		}
  1519  	}))
  1520  	res, err := cst.c.Head(cst.ts.URL)
  1521  	if err != nil {
  1522  		t.Error(err)
  1523  	}
  1524  	if len(res.TransferEncoding) > 0 {
  1525  		t.Errorf("expected no TransferEncoding; got %v", res.TransferEncoding)
  1526  	}
  1527  	if ct := res.Header.Get("Content-Type"); ct != "text/html; charset=utf-8" {
  1528  		t.Errorf("Content-Type: %q; want text/html; charset=utf-8", ct)
  1529  	}
  1530  	if v := res.ContentLength; v != 10 {
  1531  		t.Errorf("Content-Length: %d; want 10", v)
  1532  	}
  1533  	body, err := io.ReadAll(res.Body)
  1534  	if err != nil {
  1535  		t.Error(err)
  1536  	}
  1537  	if len(body) > 0 {
  1538  		t.Errorf("got unexpected body %q", string(body))
  1539  	}
  1540  }
  1541  
  1542  // Ensure ResponseWriter.ReadFrom doesn't write a body in response to a HEAD request.
  1543  // https://go.dev/issue/68609
  1544  func TestHeadReaderFrom(t *testing.T) { run(t, testHeadReaderFrom, []testMode{http1Mode}) }
  1545  func testHeadReaderFrom(t *testing.T, mode testMode) {
  1546  	// Body is large enough to exceed the content-sniffing length.
  1547  	wantBody := strings.Repeat("a", 4096)
  1548  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  1549  		w.(io.ReaderFrom).ReadFrom(strings.NewReader(wantBody))
  1550  	}))
  1551  	res, err := cst.c.Head(cst.ts.URL)
  1552  	if err != nil {
  1553  		t.Fatal(err)
  1554  	}
  1555  	res.Body.Close()
  1556  	res, err = cst.c.Get(cst.ts.URL)
  1557  	if err != nil {
  1558  		t.Fatal(err)
  1559  	}
  1560  	gotBody, err := io.ReadAll(res.Body)
  1561  	res.Body.Close()
  1562  	if err != nil {
  1563  		t.Fatal(err)
  1564  	}
  1565  	if string(gotBody) != wantBody {
  1566  		t.Errorf("got unexpected body len=%v, want %v", len(gotBody), len(wantBody))
  1567  	}
  1568  }
  1569  
  1570  func TestTLSHandshakeTimeout(t *testing.T) {
  1571  	run(t, testTLSHandshakeTimeout, []testMode{https1Mode, http2Mode})
  1572  }
  1573  func testTLSHandshakeTimeout(t *testing.T, mode testMode) {
  1574  	errLog := new(strings.Builder)
  1575  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {}),
  1576  		func(ts *httptest.Server) {
  1577  			ts.Config.ReadTimeout = 250 * time.Millisecond
  1578  			ts.Config.ErrorLog = log.New(errLog, "", 0)
  1579  		},
  1580  	)
  1581  	ts := cst.ts
  1582  
  1583  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  1584  	if err != nil {
  1585  		t.Fatalf("Dial: %v", err)
  1586  	}
  1587  	var buf [1]byte
  1588  	n, err := conn.Read(buf[:])
  1589  	if err == nil || n != 0 {
  1590  		t.Errorf("Read = %d, %v; want an error and no bytes", n, err)
  1591  	}
  1592  	conn.Close()
  1593  
  1594  	cst.close()
  1595  	if v := errLog.String(); !strings.Contains(v, "timeout") && !strings.Contains(v, "TLS handshake") {
  1596  		t.Errorf("expected a TLS handshake timeout error; got %q", v)
  1597  	}
  1598  }
  1599  
  1600  func TestTLSServer(t *testing.T) { run(t, testTLSServer, []testMode{https1Mode, http2Mode}) }
  1601  func testTLSServer(t *testing.T, mode testMode) {
  1602  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  1603  		if r.TLS != nil {
  1604  			w.Header().Set("X-TLS-Set", "true")
  1605  			if r.TLS.HandshakeComplete {
  1606  				w.Header().Set("X-TLS-HandshakeComplete", "true")
  1607  			}
  1608  		}
  1609  	}), func(ts *httptest.Server) {
  1610  		ts.Config.ErrorLog = log.New(io.Discard, "", 0)
  1611  	}).ts
  1612  
  1613  	// Connect an idle TCP connection to this server before we run
  1614  	// our real tests. This idle connection used to block forever
  1615  	// in the TLS handshake, preventing future connections from
  1616  	// being accepted. It may prevent future accidental blocking
  1617  	// in newConn.
  1618  	idleConn, err := net.Dial("tcp", ts.Listener.Addr().String())
  1619  	if err != nil {
  1620  		t.Fatalf("Dial: %v", err)
  1621  	}
  1622  	defer idleConn.Close()
  1623  
  1624  	if !strings.HasPrefix(ts.URL, "https://") {
  1625  		t.Errorf("expected test TLS server to start with https://, got %q", ts.URL)
  1626  		return
  1627  	}
  1628  	client := ts.Client()
  1629  	res, err := client.Get(ts.URL)
  1630  	if err != nil {
  1631  		t.Error(err)
  1632  		return
  1633  	}
  1634  	if res == nil {
  1635  		t.Errorf("got nil Response")
  1636  		return
  1637  	}
  1638  	defer res.Body.Close()
  1639  	if res.Header.Get("X-TLS-Set") != "true" {
  1640  		t.Errorf("expected X-TLS-Set response header")
  1641  		return
  1642  	}
  1643  	if res.Header.Get("X-TLS-HandshakeComplete") != "true" {
  1644  		t.Errorf("expected X-TLS-HandshakeComplete header")
  1645  	}
  1646  }
  1647  
  1648  func TestServeTLS(t *testing.T) {
  1649  	CondSkipHTTP2(t)
  1650  	// Not parallel: uses global test hooks.
  1651  	defer afterTest(t)
  1652  	defer SetTestHookServerServe(nil)
  1653  
  1654  	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
  1655  	if err != nil {
  1656  		t.Fatal(err)
  1657  	}
  1658  	tlsConf := &tls.Config{
  1659  		Certificates: []tls.Certificate{cert},
  1660  	}
  1661  
  1662  	ln := newLocalListener(t)
  1663  	defer ln.Close()
  1664  	addr := ln.Addr().String()
  1665  
  1666  	serving := make(chan bool, 1)
  1667  	SetTestHookServerServe(func(s *Server, ln net.Listener) {
  1668  		serving <- true
  1669  	})
  1670  	handler := HandlerFunc(func(w ResponseWriter, r *Request) {})
  1671  	s := &Server{
  1672  		Addr:      addr,
  1673  		TLSConfig: tlsConf,
  1674  		Handler:   handler,
  1675  	}
  1676  	errc := make(chan error, 1)
  1677  	go func() { errc <- s.ServeTLS(ln, "", "") }()
  1678  	select {
  1679  	case err := <-errc:
  1680  		t.Fatalf("ServeTLS: %v", err)
  1681  	case <-serving:
  1682  	}
  1683  
  1684  	c, err := tls.Dial("tcp", ln.Addr().String(), &tls.Config{
  1685  		InsecureSkipVerify: true,
  1686  		NextProtos:         []string{"h2", "http/1.1"},
  1687  	})
  1688  	if err != nil {
  1689  		t.Fatal(err)
  1690  	}
  1691  	defer c.Close()
  1692  	if got, want := c.ConnectionState().NegotiatedProtocol, "h2"; got != want {
  1693  		t.Errorf("NegotiatedProtocol = %q; want %q", got, want)
  1694  	}
  1695  	if got, want := c.ConnectionState().NegotiatedProtocolIsMutual, true; got != want {
  1696  		t.Errorf("NegotiatedProtocolIsMutual = %v; want %v", got, want)
  1697  	}
  1698  }
  1699  
  1700  // Test that the HTTPS server nicely rejects plaintext HTTP/1.x requests.
  1701  func TestTLSServerRejectHTTPRequests(t *testing.T) {
  1702  	run(t, testTLSServerRejectHTTPRequests, []testMode{https1Mode, http2Mode})
  1703  }
  1704  func testTLSServerRejectHTTPRequests(t *testing.T, mode testMode) {
  1705  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  1706  		t.Error("unexpected HTTPS request")
  1707  	}), func(ts *httptest.Server) {
  1708  		var errBuf bytes.Buffer
  1709  		ts.Config.ErrorLog = log.New(&errBuf, "", 0)
  1710  	}).ts
  1711  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  1712  	if err != nil {
  1713  		t.Fatal(err)
  1714  	}
  1715  	defer conn.Close()
  1716  	io.WriteString(conn, "GET / HTTP/1.1\r\nHost: foo\r\n\r\n")
  1717  	slurp, err := io.ReadAll(conn)
  1718  	if err != nil {
  1719  		t.Fatal(err)
  1720  	}
  1721  	const wantPrefix = "HTTP/1.0 400 Bad Request\r\n"
  1722  	if !strings.HasPrefix(string(slurp), wantPrefix) {
  1723  		t.Errorf("response = %q; wanted prefix %q", slurp, wantPrefix)
  1724  	}
  1725  }
  1726  
  1727  // Issue 15908
  1728  func TestAutomaticHTTP2_Serve_NoTLSConfig(t *testing.T) {
  1729  	testAutomaticHTTP2_Serve(t, nil, true)
  1730  }
  1731  
  1732  func TestAutomaticHTTP2_Serve_NonH2TLSConfig(t *testing.T) {
  1733  	testAutomaticHTTP2_Serve(t, &tls.Config{}, false)
  1734  }
  1735  
  1736  func TestAutomaticHTTP2_Serve_H2TLSConfig(t *testing.T) {
  1737  	testAutomaticHTTP2_Serve(t, &tls.Config{NextProtos: []string{"h2"}}, true)
  1738  }
  1739  
  1740  func testAutomaticHTTP2_Serve(t *testing.T, tlsConf *tls.Config, wantH2 bool) {
  1741  	setParallel(t)
  1742  	defer afterTest(t)
  1743  	ln := newLocalListener(t)
  1744  	ln.Close() // immediately (not a defer!)
  1745  	var s Server
  1746  	s.TLSConfig = tlsConf
  1747  	if err := s.Serve(ln); err == nil {
  1748  		t.Fatal("expected an error")
  1749  	}
  1750  	gotH2 := s.TLSNextProto["h2"] != nil
  1751  	if gotH2 != wantH2 {
  1752  		t.Errorf("http2 configured = %v; want %v", gotH2, wantH2)
  1753  	}
  1754  }
  1755  
  1756  func TestAutomaticHTTP2_Serve_WithTLSConfig(t *testing.T) {
  1757  	setParallel(t)
  1758  	defer afterTest(t)
  1759  	ln := newLocalListener(t)
  1760  	ln.Close() // immediately (not a defer!)
  1761  	var s Server
  1762  	// Set the TLSConfig. In reality, this would be the
  1763  	// *tls.Config given to tls.NewListener.
  1764  	s.TLSConfig = &tls.Config{
  1765  		NextProtos: []string{"h2"},
  1766  	}
  1767  	if err := s.Serve(ln); err == nil {
  1768  		t.Fatal("expected an error")
  1769  	}
  1770  	on := s.TLSNextProto["h2"] != nil
  1771  	if !on {
  1772  		t.Errorf("http2 wasn't automatically enabled")
  1773  	}
  1774  }
  1775  
  1776  func TestAutomaticHTTP2_ListenAndServe(t *testing.T) {
  1777  	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
  1778  	if err != nil {
  1779  		t.Fatal(err)
  1780  	}
  1781  	testAutomaticHTTP2_ListenAndServe(t, &tls.Config{
  1782  		Certificates: []tls.Certificate{cert},
  1783  	})
  1784  }
  1785  
  1786  func TestAutomaticHTTP2_ListenAndServe_GetCertificate(t *testing.T) {
  1787  	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
  1788  	if err != nil {
  1789  		t.Fatal(err)
  1790  	}
  1791  	testAutomaticHTTP2_ListenAndServe(t, &tls.Config{
  1792  		GetCertificate: func(clientHello *tls.ClientHelloInfo) (*tls.Certificate, error) {
  1793  			return &cert, nil
  1794  		},
  1795  	})
  1796  }
  1797  
  1798  func TestAutomaticHTTP2_ListenAndServe_GetConfigForClient(t *testing.T) {
  1799  	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
  1800  	if err != nil {
  1801  		t.Fatal(err)
  1802  	}
  1803  	conf := &tls.Config{
  1804  		// GetConfigForClient requires specifying a full tls.Config so we must set
  1805  		// NextProtos ourselves.
  1806  		NextProtos:   []string{"h2"},
  1807  		Certificates: []tls.Certificate{cert},
  1808  	}
  1809  	testAutomaticHTTP2_ListenAndServe(t, &tls.Config{
  1810  		GetConfigForClient: func(clientHello *tls.ClientHelloInfo) (*tls.Config, error) {
  1811  			return conf, nil
  1812  		},
  1813  	})
  1814  }
  1815  
  1816  func testAutomaticHTTP2_ListenAndServe(t *testing.T, tlsConf *tls.Config) {
  1817  	CondSkipHTTP2(t)
  1818  	// Not parallel: uses global test hooks.
  1819  	defer afterTest(t)
  1820  	defer SetTestHookServerServe(nil)
  1821  	var ok bool
  1822  	var s *Server
  1823  	const maxTries = 5
  1824  	var ln net.Listener
  1825  Try:
  1826  	for try := 0; try < maxTries; try++ {
  1827  		ln = newLocalListener(t)
  1828  		addr := ln.Addr().String()
  1829  		ln.Close()
  1830  		t.Logf("Got %v", addr)
  1831  		lnc := make(chan net.Listener, 1)
  1832  		SetTestHookServerServe(func(s *Server, ln net.Listener) {
  1833  			lnc <- ln
  1834  		})
  1835  		s = &Server{
  1836  			Addr:      addr,
  1837  			TLSConfig: tlsConf,
  1838  		}
  1839  		errc := make(chan error, 1)
  1840  		go func() { errc <- s.ListenAndServeTLS("", "") }()
  1841  		select {
  1842  		case err := <-errc:
  1843  			t.Logf("On try #%v: %v", try+1, err)
  1844  			continue
  1845  		case ln = <-lnc:
  1846  			ok = true
  1847  			t.Logf("Listening on %v", ln.Addr().String())
  1848  			break Try
  1849  		}
  1850  	}
  1851  	if !ok {
  1852  		t.Fatalf("Failed to start up after %d tries", maxTries)
  1853  	}
  1854  	defer ln.Close()
  1855  	c, err := tls.Dial("tcp", ln.Addr().String(), &tls.Config{
  1856  		InsecureSkipVerify: true,
  1857  		NextProtos:         []string{"h2", "http/1.1"},
  1858  	})
  1859  	if err != nil {
  1860  		t.Fatal(err)
  1861  	}
  1862  	defer c.Close()
  1863  	if got, want := c.ConnectionState().NegotiatedProtocol, "h2"; got != want {
  1864  		t.Errorf("NegotiatedProtocol = %q; want %q", got, want)
  1865  	}
  1866  	if got, want := c.ConnectionState().NegotiatedProtocolIsMutual, true; got != want {
  1867  		t.Errorf("NegotiatedProtocolIsMutual = %v; want %v", got, want)
  1868  	}
  1869  }
  1870  
  1871  type serverExpectTest struct {
  1872  	contentLength    int // of request body
  1873  	chunked          bool
  1874  	expectation      string // e.g. "100-continue"
  1875  	readBody         bool   // whether handler should read the body (if false, sends StatusUnauthorized)
  1876  	expectedResponse string // expected substring in first line of http response
  1877  }
  1878  
  1879  func expectTest(contentLength int, expectation string, readBody bool, expectedResponse string) serverExpectTest {
  1880  	return serverExpectTest{
  1881  		contentLength:    contentLength,
  1882  		expectation:      expectation,
  1883  		readBody:         readBody,
  1884  		expectedResponse: expectedResponse,
  1885  	}
  1886  }
  1887  
  1888  var serverExpectTests = []serverExpectTest{
  1889  	// Normal 100-continues, case-insensitive.
  1890  	expectTest(100, "100-continue", true, "100 Continue"),
  1891  	expectTest(100, "100-cOntInUE", true, "100 Continue"),
  1892  
  1893  	// No 100-continue.
  1894  	expectTest(100, "", true, "200 OK"),
  1895  
  1896  	// 100-continue but requesting client to deny us,
  1897  	// so it never reads the body.
  1898  	expectTest(100, "100-continue", false, "401 Unauthorized"),
  1899  	// Likewise without 100-continue:
  1900  	expectTest(100, "", false, "401 Unauthorized"),
  1901  
  1902  	// Non-standard expectations are failures
  1903  	expectTest(0, "a-pony", false, "417 Expectation Failed"),
  1904  
  1905  	// Expect-100 requested but no body (is apparently okay: Issue 7625)
  1906  	expectTest(0, "100-continue", true, "200 OK"),
  1907  	// Expect-100 requested but handler doesn't read the body
  1908  	expectTest(0, "100-continue", false, "401 Unauthorized"),
  1909  	// Expect-100 continue with no body, but a chunked body.
  1910  	{
  1911  		expectation:      "100-continue",
  1912  		readBody:         true,
  1913  		chunked:          true,
  1914  		expectedResponse: "100 Continue",
  1915  	},
  1916  }
  1917  
  1918  // Tests that the server responds to the "Expect" request header
  1919  // correctly.
  1920  func TestServerExpect(t *testing.T) { run(t, testServerExpect, []testMode{http1Mode}) }
  1921  func testServerExpect(t *testing.T, mode testMode) {
  1922  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  1923  		// Note using r.FormValue("readbody") because for POST
  1924  		// requests that would read from r.Body, which we only
  1925  		// conditionally want to do.
  1926  		if strings.Contains(r.URL.RawQuery, "readbody=true") {
  1927  			io.ReadAll(r.Body)
  1928  			w.Write([]byte("Hi"))
  1929  		} else {
  1930  			w.WriteHeader(StatusUnauthorized)
  1931  		}
  1932  	})).ts
  1933  
  1934  	runTest := func(test serverExpectTest) {
  1935  		conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  1936  		if err != nil {
  1937  			t.Fatalf("Dial: %v", err)
  1938  		}
  1939  		defer conn.Close()
  1940  
  1941  		// Only send the body immediately if we're acting like an HTTP client
  1942  		// that doesn't send 100-continue expectations.
  1943  		writeBody := test.contentLength != 0 && strings.ToLower(test.expectation) != "100-continue"
  1944  
  1945  		wg := sync.WaitGroup{}
  1946  		wg.Add(1)
  1947  		defer wg.Wait()
  1948  
  1949  		go func() {
  1950  			defer wg.Done()
  1951  
  1952  			contentLen := fmt.Sprintf("Content-Length: %d", test.contentLength)
  1953  			if test.chunked {
  1954  				contentLen = "Transfer-Encoding: chunked"
  1955  			}
  1956  			_, err := fmt.Fprintf(conn, "POST /?readbody=%v HTTP/1.1\r\n"+
  1957  				"Connection: close\r\n"+
  1958  				"%s\r\n"+
  1959  				"Expect: %s\r\nHost: foo\r\n\r\n",
  1960  				test.readBody, contentLen, test.expectation)
  1961  			if err != nil {
  1962  				t.Errorf("On test %#v, error writing request headers: %v", test, err)
  1963  				return
  1964  			}
  1965  			if writeBody {
  1966  				var targ io.WriteCloser = struct {
  1967  					io.Writer
  1968  					io.Closer
  1969  				}{
  1970  					conn,
  1971  					io.NopCloser(nil),
  1972  				}
  1973  				if test.chunked {
  1974  					targ = httputil.NewChunkedWriter(conn)
  1975  				}
  1976  				body := strings.Repeat("A", test.contentLength)
  1977  				_, err = fmt.Fprint(targ, body)
  1978  				if err == nil {
  1979  					err = targ.Close()
  1980  				}
  1981  				if err != nil {
  1982  					if !test.readBody {
  1983  						// Server likely already hung up on us.
  1984  						// See larger comment below.
  1985  						t.Logf("On test %#v, acceptable error writing request body: %v", test, err)
  1986  						return
  1987  					}
  1988  					t.Errorf("On test %#v, error writing request body: %v", test, err)
  1989  				}
  1990  			}
  1991  		}()
  1992  		bufr := bufio.NewReader(conn)
  1993  		line, err := bufr.ReadString('\n')
  1994  		if err != nil {
  1995  			if writeBody && !test.readBody {
  1996  				// This is an acceptable failure due to a possible TCP race:
  1997  				// We were still writing data and the server hung up on us. A TCP
  1998  				// implementation may send a RST if our request body data was known
  1999  				// to be lost, which may trigger our reads to fail.
  2000  				// See RFC 1122 page 88.
  2001  				t.Logf("On test %#v, acceptable error from ReadString: %v", test, err)
  2002  				return
  2003  			}
  2004  			t.Fatalf("On test %#v, ReadString: %v", test, err)
  2005  		}
  2006  		if !strings.Contains(line, test.expectedResponse) {
  2007  			t.Errorf("On test %#v, got first line = %q; want %q", test, line, test.expectedResponse)
  2008  		}
  2009  	}
  2010  
  2011  	for _, test := range serverExpectTests {
  2012  		runTest(test)
  2013  	}
  2014  }
  2015  
  2016  // Under a ~256KB (maxPostHandlerReadBytes) threshold, the server
  2017  // should consume client request bodies that a handler didn't read.
  2018  func TestServerUnreadRequestBodyLittle(t *testing.T) {
  2019  	setParallel(t)
  2020  	defer afterTest(t)
  2021  	conn := new(testConn)
  2022  	body := strings.Repeat("x", 100<<10)
  2023  	conn.readBuf.Write([]byte(fmt.Sprintf(
  2024  		"POST / HTTP/1.1\r\n"+
  2025  			"Host: test\r\n"+
  2026  			"Content-Length: %d\r\n"+
  2027  			"\r\n", len(body))))
  2028  	conn.readBuf.Write([]byte(body))
  2029  
  2030  	done := make(chan bool)
  2031  
  2032  	readBufLen := func() int {
  2033  		conn.readMu.Lock()
  2034  		defer conn.readMu.Unlock()
  2035  		return conn.readBuf.Len()
  2036  	}
  2037  
  2038  	ls := &oneConnListener{conn}
  2039  	go Serve(ls, HandlerFunc(func(rw ResponseWriter, req *Request) {
  2040  		defer close(done)
  2041  		if bufLen := readBufLen(); bufLen < len(body)/2 {
  2042  			t.Errorf("on request, read buffer length is %d; expected about 100 KB", bufLen)
  2043  		}
  2044  		rw.WriteHeader(200)
  2045  		rw.(Flusher).Flush()
  2046  		if g, e := readBufLen(), 0; g != e {
  2047  			t.Errorf("after WriteHeader, read buffer length is %d; want %d", g, e)
  2048  		}
  2049  		if c := rw.Header().Get("Connection"); c != "" {
  2050  			t.Errorf(`Connection header = %q; want ""`, c)
  2051  		}
  2052  	}))
  2053  	<-done
  2054  }
  2055  
  2056  // Over a ~256KB (maxPostHandlerReadBytes) threshold, the server
  2057  // should ignore client request bodies that a handler didn't read
  2058  // and close the connection.
  2059  func TestServerUnreadRequestBodyLarge(t *testing.T) {
  2060  	setParallel(t)
  2061  	if testing.Short() && testenv.Builder() == "" {
  2062  		t.Log("skipping in short mode")
  2063  	}
  2064  	conn := new(testConn)
  2065  	body := strings.Repeat("x", 1<<20)
  2066  	conn.readBuf.Write([]byte(fmt.Sprintf(
  2067  		"POST / HTTP/1.1\r\n"+
  2068  			"Host: test\r\n"+
  2069  			"Content-Length: %d\r\n"+
  2070  			"\r\n", len(body))))
  2071  	conn.readBuf.Write([]byte(body))
  2072  	conn.closec = make(chan bool, 1)
  2073  
  2074  	ls := &oneConnListener{conn}
  2075  	go Serve(ls, HandlerFunc(func(rw ResponseWriter, req *Request) {
  2076  		if conn.readBuf.Len() < len(body)/2 {
  2077  			t.Errorf("on request, read buffer length is %d; expected about 1MB", conn.readBuf.Len())
  2078  		}
  2079  		rw.WriteHeader(200)
  2080  		rw.(Flusher).Flush()
  2081  		if conn.readBuf.Len() < len(body)/2 {
  2082  			t.Errorf("post-WriteHeader, read buffer length is %d; expected about 1MB", conn.readBuf.Len())
  2083  		}
  2084  	}))
  2085  	<-conn.closec
  2086  
  2087  	if res := conn.writeBuf.String(); !strings.Contains(res, "Connection: close") {
  2088  		t.Errorf("Expected a Connection: close header; got response: %s", res)
  2089  	}
  2090  }
  2091  
  2092  type handlerBodyCloseTest struct {
  2093  	bodySize     int
  2094  	bodyChunked  bool
  2095  	reqConnClose bool
  2096  
  2097  	wantEOFSearch bool // should Handler's Body.Close do Reads, looking for EOF?
  2098  	wantNextReq   bool // should it find the next request on the same conn?
  2099  }
  2100  
  2101  func (t handlerBodyCloseTest) connectionHeader() string {
  2102  	if t.reqConnClose {
  2103  		return "Connection: close\r\n"
  2104  	}
  2105  	return ""
  2106  }
  2107  
  2108  var handlerBodyCloseTests = [...]handlerBodyCloseTest{
  2109  	// Small enough to slurp past to the next request +
  2110  	// has Content-Length.
  2111  	0: {
  2112  		bodySize:      20 << 10,
  2113  		bodyChunked:   false,
  2114  		reqConnClose:  false,
  2115  		wantEOFSearch: true,
  2116  		wantNextReq:   true,
  2117  	},
  2118  
  2119  	// Small enough to slurp past to the next request +
  2120  	// is chunked.
  2121  	1: {
  2122  		bodySize:      20 << 10,
  2123  		bodyChunked:   true,
  2124  		reqConnClose:  false,
  2125  		wantEOFSearch: true,
  2126  		wantNextReq:   true,
  2127  	},
  2128  
  2129  	// Small enough to slurp past to the next request +
  2130  	// has Content-Length +
  2131  	// declares Connection: close (so pointless to read more).
  2132  	2: {
  2133  		bodySize:      20 << 10,
  2134  		bodyChunked:   false,
  2135  		reqConnClose:  true,
  2136  		wantEOFSearch: false,
  2137  		wantNextReq:   false,
  2138  	},
  2139  
  2140  	// Small enough to slurp past to the next request +
  2141  	// declares Connection: close,
  2142  	// but chunked, so it might have trailers.
  2143  	// TODO: maybe skip this search if no trailers were declared
  2144  	// in the headers.
  2145  	3: {
  2146  		bodySize:      20 << 10,
  2147  		bodyChunked:   true,
  2148  		reqConnClose:  true,
  2149  		wantEOFSearch: true,
  2150  		wantNextReq:   false,
  2151  	},
  2152  
  2153  	// Big with Content-Length, so give up immediately if we know it's too big.
  2154  	4: {
  2155  		bodySize:      1 << 20,
  2156  		bodyChunked:   false, // has a Content-Length
  2157  		reqConnClose:  false,
  2158  		wantEOFSearch: false,
  2159  		wantNextReq:   false,
  2160  	},
  2161  
  2162  	// Big chunked, so read a bit before giving up.
  2163  	5: {
  2164  		bodySize:      1 << 20,
  2165  		bodyChunked:   true,
  2166  		reqConnClose:  false,
  2167  		wantEOFSearch: true,
  2168  		wantNextReq:   false,
  2169  	},
  2170  
  2171  	// Big with Connection: close, but chunked, so search for trailers.
  2172  	// TODO: maybe skip this search if no trailers were declared
  2173  	// in the headers.
  2174  	6: {
  2175  		bodySize:      1 << 20,
  2176  		bodyChunked:   true,
  2177  		reqConnClose:  true,
  2178  		wantEOFSearch: true,
  2179  		wantNextReq:   false,
  2180  	},
  2181  
  2182  	// Big with Connection: close, so don't do any reads on Close.
  2183  	// With Content-Length.
  2184  	7: {
  2185  		bodySize:      1 << 20,
  2186  		bodyChunked:   false,
  2187  		reqConnClose:  true,
  2188  		wantEOFSearch: false,
  2189  		wantNextReq:   false,
  2190  	},
  2191  }
  2192  
  2193  func TestHandlerBodyClose(t *testing.T) {
  2194  	setParallel(t)
  2195  	if testing.Short() && testenv.Builder() == "" {
  2196  		t.Skip("skipping in -short mode")
  2197  	}
  2198  	for i, tt := range handlerBodyCloseTests {
  2199  		testHandlerBodyClose(t, i, tt)
  2200  	}
  2201  }
  2202  
  2203  func testHandlerBodyClose(t *testing.T, i int, tt handlerBodyCloseTest) {
  2204  	conn := new(testConn)
  2205  	body := strings.Repeat("x", tt.bodySize)
  2206  	if tt.bodyChunked {
  2207  		conn.readBuf.WriteString("POST / HTTP/1.1\r\n" +
  2208  			"Host: test\r\n" +
  2209  			tt.connectionHeader() +
  2210  			"Transfer-Encoding: chunked\r\n" +
  2211  			"\r\n")
  2212  		cw := internal.NewChunkedWriter(&conn.readBuf)
  2213  		io.WriteString(cw, body)
  2214  		cw.Close()
  2215  		conn.readBuf.WriteString("\r\n")
  2216  	} else {
  2217  		conn.readBuf.Write([]byte(fmt.Sprintf(
  2218  			"POST / HTTP/1.1\r\n"+
  2219  				"Host: test\r\n"+
  2220  				tt.connectionHeader()+
  2221  				"Content-Length: %d\r\n"+
  2222  				"\r\n", len(body))))
  2223  		conn.readBuf.Write([]byte(body))
  2224  	}
  2225  	if !tt.reqConnClose {
  2226  		conn.readBuf.WriteString("GET / HTTP/1.1\r\nHost: test\r\n\r\n")
  2227  	}
  2228  	conn.closec = make(chan bool, 1)
  2229  
  2230  	readBufLen := func() int {
  2231  		conn.readMu.Lock()
  2232  		defer conn.readMu.Unlock()
  2233  		return conn.readBuf.Len()
  2234  	}
  2235  
  2236  	ls := &oneConnListener{conn}
  2237  	var numReqs int
  2238  	var size0, size1 int
  2239  	go Serve(ls, HandlerFunc(func(rw ResponseWriter, req *Request) {
  2240  		numReqs++
  2241  		if numReqs == 1 {
  2242  			size0 = readBufLen()
  2243  			req.Body.Close()
  2244  			size1 = readBufLen()
  2245  		}
  2246  	}))
  2247  	<-conn.closec
  2248  	if numReqs < 1 || numReqs > 2 {
  2249  		t.Fatalf("%d. bug in test. unexpected number of requests = %d", i, numReqs)
  2250  	}
  2251  	didSearch := size0 != size1
  2252  	if didSearch != tt.wantEOFSearch {
  2253  		t.Errorf("%d. did EOF search = %v; want %v (size went from %d to %d)", i, didSearch, !didSearch, size0, size1)
  2254  	}
  2255  	if tt.wantNextReq && numReqs != 2 {
  2256  		t.Errorf("%d. numReq = %d; want 2", i, numReqs)
  2257  	}
  2258  }
  2259  
  2260  // testHandlerBodyConsumer represents a function injected into a test handler to
  2261  // vary work done on a request Body.
  2262  type testHandlerBodyConsumer struct {
  2263  	name string
  2264  	f    func(io.ReadCloser)
  2265  }
  2266  
  2267  var testHandlerBodyConsumers = []testHandlerBodyConsumer{
  2268  	{"nil", func(io.ReadCloser) {}},
  2269  	{"close", func(r io.ReadCloser) { r.Close() }},
  2270  	{"discard", func(r io.ReadCloser) { io.Copy(io.Discard, r) }},
  2271  }
  2272  
  2273  func TestRequestBodyReadErrorClosesConnection(t *testing.T) {
  2274  	setParallel(t)
  2275  	defer afterTest(t)
  2276  	for _, handler := range testHandlerBodyConsumers {
  2277  		conn := new(testConn)
  2278  		conn.readBuf.WriteString("POST /public HTTP/1.1\r\n" +
  2279  			"Host: test\r\n" +
  2280  			"Transfer-Encoding: chunked\r\n" +
  2281  			"\r\n" +
  2282  			"hax\r\n" + // Invalid chunked encoding
  2283  			"GET /secret HTTP/1.1\r\n" +
  2284  			"Host: test\r\n" +
  2285  			"\r\n")
  2286  
  2287  		conn.closec = make(chan bool, 1)
  2288  		ls := &oneConnListener{conn}
  2289  		var numReqs int
  2290  		go Serve(ls, HandlerFunc(func(_ ResponseWriter, req *Request) {
  2291  			numReqs++
  2292  			if strings.Contains(req.URL.Path, "secret") {
  2293  				t.Error("Request for /secret encountered, should not have happened.")
  2294  			}
  2295  			handler.f(req.Body)
  2296  		}))
  2297  		<-conn.closec
  2298  		if numReqs != 1 {
  2299  			t.Errorf("Handler %v: got %d reqs; want 1", handler.name, numReqs)
  2300  		}
  2301  	}
  2302  }
  2303  
  2304  func TestInvalidTrailerClosesConnection(t *testing.T) {
  2305  	setParallel(t)
  2306  	defer afterTest(t)
  2307  	for _, handler := range testHandlerBodyConsumers {
  2308  		conn := new(testConn)
  2309  		conn.readBuf.WriteString("POST /public HTTP/1.1\r\n" +
  2310  			"Host: test\r\n" +
  2311  			"Trailer: hack\r\n" +
  2312  			"Transfer-Encoding: chunked\r\n" +
  2313  			"\r\n" +
  2314  			"3\r\n" +
  2315  			"hax\r\n" +
  2316  			"0\r\n" +
  2317  			"I'm not a valid trailer\r\n" +
  2318  			"GET /secret HTTP/1.1\r\n" +
  2319  			"Host: test\r\n" +
  2320  			"\r\n")
  2321  
  2322  		conn.closec = make(chan bool, 1)
  2323  		ln := &oneConnListener{conn}
  2324  		var numReqs int
  2325  		go Serve(ln, HandlerFunc(func(_ ResponseWriter, req *Request) {
  2326  			numReqs++
  2327  			if strings.Contains(req.URL.Path, "secret") {
  2328  				t.Errorf("Handler %s, Request for /secret encountered, should not have happened.", handler.name)
  2329  			}
  2330  			handler.f(req.Body)
  2331  		}))
  2332  		<-conn.closec
  2333  		if numReqs != 1 {
  2334  			t.Errorf("Handler %s: got %d reqs; want 1", handler.name, numReqs)
  2335  		}
  2336  	}
  2337  }
  2338  
  2339  // slowTestConn is a net.Conn that provides a means to simulate parts of a
  2340  // request being received piecemeal. Deadlines can be set and enforced in both
  2341  // Read and Write.
  2342  type slowTestConn struct {
  2343  	// over multiple calls to Read, time.Durations are slept, strings are read.
  2344  	script []any
  2345  	closec chan bool
  2346  
  2347  	mu     sync.Mutex // guards rd/wd
  2348  	rd, wd time.Time  // read, write deadline
  2349  	noopConn
  2350  }
  2351  
  2352  func (c *slowTestConn) SetDeadline(t time.Time) error {
  2353  	c.SetReadDeadline(t)
  2354  	c.SetWriteDeadline(t)
  2355  	return nil
  2356  }
  2357  
  2358  func (c *slowTestConn) SetReadDeadline(t time.Time) error {
  2359  	c.mu.Lock()
  2360  	defer c.mu.Unlock()
  2361  	c.rd = t
  2362  	return nil
  2363  }
  2364  
  2365  func (c *slowTestConn) SetWriteDeadline(t time.Time) error {
  2366  	c.mu.Lock()
  2367  	defer c.mu.Unlock()
  2368  	c.wd = t
  2369  	return nil
  2370  }
  2371  
  2372  func (c *slowTestConn) Read(b []byte) (n int, err error) {
  2373  	c.mu.Lock()
  2374  	defer c.mu.Unlock()
  2375  restart:
  2376  	if !c.rd.IsZero() && time.Now().After(c.rd) {
  2377  		return 0, syscall.ETIMEDOUT
  2378  	}
  2379  	if len(c.script) == 0 {
  2380  		return 0, io.EOF
  2381  	}
  2382  
  2383  	switch cue := c.script[0].(type) {
  2384  	case time.Duration:
  2385  		if !c.rd.IsZero() {
  2386  			// If the deadline falls in the middle of our sleep window, deduct
  2387  			// part of the sleep, then return a timeout.
  2388  			if remaining := time.Until(c.rd); remaining < cue {
  2389  				c.script[0] = cue - remaining
  2390  				time.Sleep(remaining)
  2391  				return 0, syscall.ETIMEDOUT
  2392  			}
  2393  		}
  2394  		c.script = c.script[1:]
  2395  		time.Sleep(cue)
  2396  		goto restart
  2397  
  2398  	case string:
  2399  		n = copy(b, cue)
  2400  		// If cue is too big for the buffer, leave the end for the next Read.
  2401  		if len(cue) > n {
  2402  			c.script[0] = cue[n:]
  2403  		} else {
  2404  			c.script = c.script[1:]
  2405  		}
  2406  
  2407  	default:
  2408  		panic("unknown cue in slowTestConn script")
  2409  	}
  2410  
  2411  	return
  2412  }
  2413  
  2414  func (c *slowTestConn) Close() error {
  2415  	select {
  2416  	case c.closec <- true:
  2417  	default:
  2418  	}
  2419  	return nil
  2420  }
  2421  
  2422  func (c *slowTestConn) Write(b []byte) (int, error) {
  2423  	if !c.wd.IsZero() && time.Now().After(c.wd) {
  2424  		return 0, syscall.ETIMEDOUT
  2425  	}
  2426  	return len(b), nil
  2427  }
  2428  
  2429  func TestRequestBodyTimeoutClosesConnection(t *testing.T) {
  2430  	if testing.Short() {
  2431  		t.Skip("skipping in -short mode")
  2432  	}
  2433  	defer afterTest(t)
  2434  	for _, handler := range testHandlerBodyConsumers {
  2435  		conn := &slowTestConn{
  2436  			script: []any{
  2437  				"POST /public HTTP/1.1\r\n" +
  2438  					"Host: test\r\n" +
  2439  					"Content-Length: 10000\r\n" +
  2440  					"\r\n",
  2441  				"foo bar baz",
  2442  				600 * time.Millisecond, // Request deadline should hit here
  2443  				"GET /secret HTTP/1.1\r\n" +
  2444  					"Host: test\r\n" +
  2445  					"\r\n",
  2446  			},
  2447  			closec: make(chan bool, 1),
  2448  		}
  2449  		ls := &oneConnListener{conn}
  2450  
  2451  		var numReqs int
  2452  		s := Server{
  2453  			Handler: HandlerFunc(func(_ ResponseWriter, req *Request) {
  2454  				numReqs++
  2455  				if strings.Contains(req.URL.Path, "secret") {
  2456  					t.Error("Request for /secret encountered, should not have happened.")
  2457  				}
  2458  				handler.f(req.Body)
  2459  			}),
  2460  			ReadTimeout: 400 * time.Millisecond,
  2461  		}
  2462  		go s.Serve(ls)
  2463  		<-conn.closec
  2464  
  2465  		if numReqs != 1 {
  2466  			t.Errorf("Handler %v: got %d reqs; want 1", handler.name, numReqs)
  2467  		}
  2468  	}
  2469  }
  2470  
  2471  // cancelableTimeoutContext overwrites the error message to DeadlineExceeded
  2472  type cancelableTimeoutContext struct {
  2473  	context.Context
  2474  }
  2475  
  2476  func (c cancelableTimeoutContext) Err() error {
  2477  	if c.Context.Err() != nil {
  2478  		return context.DeadlineExceeded
  2479  	}
  2480  	return nil
  2481  }
  2482  
  2483  func TestTimeoutHandler(t *testing.T) { run(t, testTimeoutHandler) }
  2484  func testTimeoutHandler(t *testing.T, mode testMode) {
  2485  	sendHi := make(chan bool, 1)
  2486  	writeErrors := make(chan error, 1)
  2487  	sayHi := HandlerFunc(func(w ResponseWriter, r *Request) {
  2488  		<-sendHi
  2489  		_, werr := w.Write([]byte("hi"))
  2490  		writeErrors <- werr
  2491  	})
  2492  	ctx, cancel := context.WithCancel(context.Background())
  2493  	h := NewTestTimeoutHandler(sayHi, cancelableTimeoutContext{ctx})
  2494  	cst := newClientServerTest(t, mode, h)
  2495  
  2496  	// Succeed without timing out:
  2497  	sendHi <- true
  2498  	res, err := cst.c.Get(cst.ts.URL)
  2499  	if err != nil {
  2500  		t.Error(err)
  2501  	}
  2502  	if g, e := res.StatusCode, StatusOK; g != e {
  2503  		t.Errorf("got res.StatusCode %d; expected %d", g, e)
  2504  	}
  2505  	body, _ := io.ReadAll(res.Body)
  2506  	if g, e := string(body), "hi"; g != e {
  2507  		t.Errorf("got body %q; expected %q", g, e)
  2508  	}
  2509  	if g := <-writeErrors; g != nil {
  2510  		t.Errorf("got unexpected Write error on first request: %v", g)
  2511  	}
  2512  
  2513  	// Times out:
  2514  	cancel()
  2515  
  2516  	res, err = cst.c.Get(cst.ts.URL)
  2517  	if err != nil {
  2518  		t.Error(err)
  2519  	}
  2520  	if g, e := res.StatusCode, StatusServiceUnavailable; g != e {
  2521  		t.Errorf("got res.StatusCode %d; expected %d", g, e)
  2522  	}
  2523  	body, _ = io.ReadAll(res.Body)
  2524  	if !strings.Contains(string(body), "<title>Timeout</title>") {
  2525  		t.Errorf("expected timeout body; got %q", string(body))
  2526  	}
  2527  	if g, w := res.Header.Get("Content-Type"), "text/html; charset=utf-8"; g != w {
  2528  		t.Errorf("response content-type = %q; want %q", g, w)
  2529  	}
  2530  
  2531  	// Now make the previously-timed out handler speak again,
  2532  	// which verifies the panic is handled:
  2533  	sendHi <- true
  2534  	if g, e := <-writeErrors, ErrHandlerTimeout; g != e {
  2535  		t.Errorf("expected Write error of %v; got %v", e, g)
  2536  	}
  2537  }
  2538  
  2539  // See issues 8209 and 8414.
  2540  func TestTimeoutHandlerRace(t *testing.T) { run(t, testTimeoutHandlerRace) }
  2541  func testTimeoutHandlerRace(t *testing.T, mode testMode) {
  2542  	delayHi := HandlerFunc(func(w ResponseWriter, r *Request) {
  2543  		ms, _ := strconv.Atoi(r.URL.Path[1:])
  2544  		if ms == 0 {
  2545  			ms = 1
  2546  		}
  2547  		for i := 0; i < ms; i++ {
  2548  			w.Write([]byte("hi"))
  2549  			time.Sleep(time.Millisecond)
  2550  		}
  2551  	})
  2552  
  2553  	ts := newClientServerTest(t, mode, TimeoutHandler(delayHi, 20*time.Millisecond, "")).ts
  2554  
  2555  	c := ts.Client()
  2556  
  2557  	var wg sync.WaitGroup
  2558  	gate := make(chan bool, 10)
  2559  	n := 50
  2560  	if testing.Short() {
  2561  		n = 10
  2562  		gate = make(chan bool, 3)
  2563  	}
  2564  	for i := 0; i < n; i++ {
  2565  		gate <- true
  2566  		wg.Add(1)
  2567  		go func() {
  2568  			defer wg.Done()
  2569  			defer func() { <-gate }()
  2570  			res, err := c.Get(fmt.Sprintf("%s/%d", ts.URL, rand.Intn(50)))
  2571  			if err == nil {
  2572  				io.Copy(io.Discard, res.Body)
  2573  				res.Body.Close()
  2574  			}
  2575  		}()
  2576  	}
  2577  	wg.Wait()
  2578  }
  2579  
  2580  // See issues 8209 and 8414.
  2581  // Both issues involved panics in the implementation of TimeoutHandler.
  2582  func TestTimeoutHandlerRaceHeader(t *testing.T) { run(t, testTimeoutHandlerRaceHeader) }
  2583  func testTimeoutHandlerRaceHeader(t *testing.T, mode testMode) {
  2584  	delay204 := HandlerFunc(func(w ResponseWriter, r *Request) {
  2585  		w.WriteHeader(204)
  2586  	})
  2587  
  2588  	ts := newClientServerTest(t, mode, TimeoutHandler(delay204, time.Nanosecond, "")).ts
  2589  
  2590  	var wg sync.WaitGroup
  2591  	gate := make(chan bool, 50)
  2592  	n := 500
  2593  	if testing.Short() {
  2594  		n = 10
  2595  	}
  2596  
  2597  	c := ts.Client()
  2598  	for i := 0; i < n; i++ {
  2599  		gate <- true
  2600  		wg.Add(1)
  2601  		go func() {
  2602  			defer wg.Done()
  2603  			defer func() { <-gate }()
  2604  			res, err := c.Get(ts.URL)
  2605  			if err != nil {
  2606  				// We see ECONNRESET from the connection occasionally,
  2607  				// and that's OK: this test is checking that the server does not panic.
  2608  				t.Log(err)
  2609  				return
  2610  			}
  2611  			defer res.Body.Close()
  2612  			io.Copy(io.Discard, res.Body)
  2613  		}()
  2614  	}
  2615  	wg.Wait()
  2616  }
  2617  
  2618  // Issue 9162
  2619  func TestTimeoutHandlerRaceHeaderTimeout(t *testing.T) { run(t, testTimeoutHandlerRaceHeaderTimeout) }
  2620  func testTimeoutHandlerRaceHeaderTimeout(t *testing.T, mode testMode) {
  2621  	sendHi := make(chan bool, 1)
  2622  	writeErrors := make(chan error, 1)
  2623  	sayHi := HandlerFunc(func(w ResponseWriter, r *Request) {
  2624  		w.Header().Set("Content-Type", "text/plain")
  2625  		<-sendHi
  2626  		_, werr := w.Write([]byte("hi"))
  2627  		writeErrors <- werr
  2628  	})
  2629  	ctx, cancel := context.WithCancel(context.Background())
  2630  	h := NewTestTimeoutHandler(sayHi, cancelableTimeoutContext{ctx})
  2631  	cst := newClientServerTest(t, mode, h)
  2632  
  2633  	// Succeed without timing out:
  2634  	sendHi <- true
  2635  	res, err := cst.c.Get(cst.ts.URL)
  2636  	if err != nil {
  2637  		t.Error(err)
  2638  	}
  2639  	if g, e := res.StatusCode, StatusOK; g != e {
  2640  		t.Errorf("got res.StatusCode %d; expected %d", g, e)
  2641  	}
  2642  	body, _ := io.ReadAll(res.Body)
  2643  	if g, e := string(body), "hi"; g != e {
  2644  		t.Errorf("got body %q; expected %q", g, e)
  2645  	}
  2646  	if g := <-writeErrors; g != nil {
  2647  		t.Errorf("got unexpected Write error on first request: %v", g)
  2648  	}
  2649  
  2650  	// Times out:
  2651  	cancel()
  2652  
  2653  	res, err = cst.c.Get(cst.ts.URL)
  2654  	if err != nil {
  2655  		t.Error(err)
  2656  	}
  2657  	if g, e := res.StatusCode, StatusServiceUnavailable; g != e {
  2658  		t.Errorf("got res.StatusCode %d; expected %d", g, e)
  2659  	}
  2660  	body, _ = io.ReadAll(res.Body)
  2661  	if !strings.Contains(string(body), "<title>Timeout</title>") {
  2662  		t.Errorf("expected timeout body; got %q", string(body))
  2663  	}
  2664  
  2665  	// Now make the previously-timed out handler speak again,
  2666  	// which verifies the panic is handled:
  2667  	sendHi <- true
  2668  	if g, e := <-writeErrors, ErrHandlerTimeout; g != e {
  2669  		t.Errorf("expected Write error of %v; got %v", e, g)
  2670  	}
  2671  }
  2672  
  2673  // Issue 14568.
  2674  func TestTimeoutHandlerStartTimerWhenServing(t *testing.T) {
  2675  	run(t, testTimeoutHandlerStartTimerWhenServing)
  2676  }
  2677  func testTimeoutHandlerStartTimerWhenServing(t *testing.T, mode testMode) {
  2678  	if testing.Short() {
  2679  		t.Skip("skipping sleeping test in -short mode")
  2680  	}
  2681  	var handler HandlerFunc = func(w ResponseWriter, _ *Request) {
  2682  		w.WriteHeader(StatusNoContent)
  2683  	}
  2684  	timeout := 300 * time.Millisecond
  2685  	ts := newClientServerTest(t, mode, TimeoutHandler(handler, timeout, "")).ts
  2686  	defer ts.Close()
  2687  
  2688  	c := ts.Client()
  2689  
  2690  	// Issue was caused by the timeout handler starting the timer when
  2691  	// was created, not when the request. So wait for more than the timeout
  2692  	// to ensure that's not the case.
  2693  	time.Sleep(2 * timeout)
  2694  	res, err := c.Get(ts.URL)
  2695  	if err != nil {
  2696  		t.Fatal(err)
  2697  	}
  2698  	defer res.Body.Close()
  2699  	if res.StatusCode != StatusNoContent {
  2700  		t.Errorf("got res.StatusCode %d, want %v", res.StatusCode, StatusNoContent)
  2701  	}
  2702  }
  2703  
  2704  func TestTimeoutHandlerContextCanceled(t *testing.T) { run(t, testTimeoutHandlerContextCanceled) }
  2705  func testTimeoutHandlerContextCanceled(t *testing.T, mode testMode) {
  2706  	writeErrors := make(chan error, 1)
  2707  	sayHi := HandlerFunc(func(w ResponseWriter, r *Request) {
  2708  		w.Header().Set("Content-Type", "text/plain")
  2709  		var err error
  2710  		// The request context has already been canceled, but
  2711  		// retry the write for a while to give the timeout handler
  2712  		// a chance to notice.
  2713  		for i := 0; i < 100; i++ {
  2714  			_, err = w.Write([]byte("a"))
  2715  			if err != nil {
  2716  				break
  2717  			}
  2718  			time.Sleep(1 * time.Millisecond)
  2719  		}
  2720  		writeErrors <- err
  2721  	})
  2722  	ctx, cancel := context.WithCancel(context.Background())
  2723  	cancel()
  2724  	h := NewTestTimeoutHandler(sayHi, ctx)
  2725  	cst := newClientServerTest(t, mode, h)
  2726  	defer cst.close()
  2727  
  2728  	res, err := cst.c.Get(cst.ts.URL)
  2729  	if err != nil {
  2730  		t.Error(err)
  2731  	}
  2732  	if g, e := res.StatusCode, StatusServiceUnavailable; g != e {
  2733  		t.Errorf("got res.StatusCode %d; expected %d", g, e)
  2734  	}
  2735  	body, _ := io.ReadAll(res.Body)
  2736  	if g, e := string(body), ""; g != e {
  2737  		t.Errorf("got body %q; expected %q", g, e)
  2738  	}
  2739  	if g, e := <-writeErrors, context.Canceled; g != e {
  2740  		t.Errorf("got unexpected Write in handler: %v, want %g", g, e)
  2741  	}
  2742  }
  2743  
  2744  // https://golang.org/issue/15948
  2745  func TestTimeoutHandlerEmptyResponse(t *testing.T) { run(t, testTimeoutHandlerEmptyResponse) }
  2746  func testTimeoutHandlerEmptyResponse(t *testing.T, mode testMode) {
  2747  	var handler HandlerFunc = func(w ResponseWriter, _ *Request) {
  2748  		// No response.
  2749  	}
  2750  	timeout := 300 * time.Millisecond
  2751  	ts := newClientServerTest(t, mode, TimeoutHandler(handler, timeout, "")).ts
  2752  
  2753  	c := ts.Client()
  2754  
  2755  	res, err := c.Get(ts.URL)
  2756  	if err != nil {
  2757  		t.Fatal(err)
  2758  	}
  2759  	defer res.Body.Close()
  2760  	if res.StatusCode != StatusOK {
  2761  		t.Errorf("got res.StatusCode %d, want %v", res.StatusCode, StatusOK)
  2762  	}
  2763  }
  2764  
  2765  // https://golang.org/issues/22084
  2766  func TestTimeoutHandlerPanicRecovery(t *testing.T) {
  2767  	wrapper := func(h Handler) Handler {
  2768  		return TimeoutHandler(h, time.Second, "")
  2769  	}
  2770  	run(t, func(t *testing.T, mode testMode) {
  2771  		testHandlerPanic(t, false, mode, wrapper, "intentional death for testing")
  2772  	}, testNotParallel)
  2773  }
  2774  
  2775  func TestRedirectBadPath(t *testing.T) {
  2776  	// This used to crash. It's not valid input (bad path), but it
  2777  	// shouldn't crash.
  2778  	rr := httptest.NewRecorder()
  2779  	req := &Request{
  2780  		Method: "GET",
  2781  		URL: &url.URL{
  2782  			Scheme: "http",
  2783  			Path:   "not-empty-but-no-leading-slash", // bogus
  2784  		},
  2785  	}
  2786  	Redirect(rr, req, "", 304)
  2787  	if rr.Code != 304 {
  2788  		t.Errorf("Code = %d; want 304", rr.Code)
  2789  	}
  2790  }
  2791  
  2792  // Test different URL formats and schemes
  2793  func TestRedirect(t *testing.T) {
  2794  	req, _ := NewRequest("GET", "http://example.com/qux/", nil)
  2795  
  2796  	var tests = []struct {
  2797  		in   string
  2798  		want string
  2799  	}{
  2800  		// normal http
  2801  		{"http://foobar.com/baz", "http://foobar.com/baz"},
  2802  		// normal https
  2803  		{"https://foobar.com/baz", "https://foobar.com/baz"},
  2804  		// custom scheme
  2805  		{"test://foobar.com/baz", "test://foobar.com/baz"},
  2806  		// schemeless
  2807  		{"//foobar.com/baz", "//foobar.com/baz"},
  2808  		// relative to the root
  2809  		{"/foobar.com/baz", "/foobar.com/baz"},
  2810  		// relative to the current path
  2811  		{"foobar.com/baz", "/qux/foobar.com/baz"},
  2812  		// relative to the current path (+ going upwards)
  2813  		{"../quux/foobar.com/baz", "/quux/foobar.com/baz"},
  2814  		// incorrect number of slashes
  2815  		{"///foobar.com/baz", "/foobar.com/baz"},
  2816  
  2817  		// Verifies we don't path.Clean() on the wrong parts in redirects:
  2818  		{"/foo?next=http://bar.com/", "/foo?next=http://bar.com/"},
  2819  		{"http://localhost:8080/_ah/login?continue=http://localhost:8080/",
  2820  			"http://localhost:8080/_ah/login?continue=http://localhost:8080/"},
  2821  
  2822  		{"/фубар", "/%d1%84%d1%83%d0%b1%d0%b0%d1%80"},
  2823  		{"http://foo.com/фубар", "http://foo.com/%d1%84%d1%83%d0%b1%d0%b0%d1%80"},
  2824  	}
  2825  
  2826  	for _, tt := range tests {
  2827  		rec := httptest.NewRecorder()
  2828  		Redirect(rec, req, tt.in, 302)
  2829  		if got, want := rec.Code, 302; got != want {
  2830  			t.Errorf("Redirect(%q) generated status code %v; want %v", tt.in, got, want)
  2831  		}
  2832  		if got := rec.Header().Get("Location"); got != tt.want {
  2833  			t.Errorf("Redirect(%q) generated Location header %q; want %q", tt.in, got, tt.want)
  2834  		}
  2835  	}
  2836  }
  2837  
  2838  // Test that Redirect sets Content-Type header for GET and HEAD requests
  2839  // and writes a short HTML body, unless the request already has a Content-Type header.
  2840  func TestRedirectContentTypeAndBody(t *testing.T) {
  2841  	type ctHeader struct {
  2842  		Values []string
  2843  	}
  2844  
  2845  	var tests = []struct {
  2846  		method   string
  2847  		ct       *ctHeader // Optional Content-Type header to set.
  2848  		wantCT   string
  2849  		wantBody string
  2850  	}{
  2851  		{MethodGet, nil, "text/html; charset=utf-8", "<a href=\"/foo\">Found</a>.\n\n"},
  2852  		{MethodHead, nil, "text/html; charset=utf-8", ""},
  2853  		{MethodPost, nil, "", ""},
  2854  		{MethodDelete, nil, "", ""},
  2855  		{"foo", nil, "", ""},
  2856  		{MethodGet, &ctHeader{[]string{"application/test"}}, "application/test", ""},
  2857  		{MethodGet, &ctHeader{[]string{}}, "", ""},
  2858  		{MethodGet, &ctHeader{nil}, "", ""},
  2859  	}
  2860  	for _, tt := range tests {
  2861  		req := httptest.NewRequest(tt.method, "http://example.com/qux/", nil)
  2862  		rec := httptest.NewRecorder()
  2863  		if tt.ct != nil {
  2864  			rec.Header()["Content-Type"] = tt.ct.Values
  2865  		}
  2866  		Redirect(rec, req, "/foo", 302)
  2867  		if got, want := rec.Code, 302; got != want {
  2868  			t.Errorf("Redirect(%q, %#v) generated status code %v; want %v", tt.method, tt.ct, got, want)
  2869  		}
  2870  		if got, want := rec.Header().Get("Content-Type"), tt.wantCT; got != want {
  2871  			t.Errorf("Redirect(%q, %#v) generated Content-Type header %q; want %q", tt.method, tt.ct, got, want)
  2872  		}
  2873  		resp := rec.Result()
  2874  		body, err := io.ReadAll(resp.Body)
  2875  		if err != nil {
  2876  			t.Fatal(err)
  2877  		}
  2878  		if got, want := string(body), tt.wantBody; got != want {
  2879  			t.Errorf("Redirect(%q, %#v) generated Body %q; want %q", tt.method, tt.ct, got, want)
  2880  		}
  2881  	}
  2882  }
  2883  
  2884  // TestZeroLengthPostAndResponse exercises an optimization done by the Transport:
  2885  // when there is no body (either because the method doesn't permit a body, or an
  2886  // explicit Content-Length of zero is present), then the transport can re-use the
  2887  // connection immediately. But when it re-uses the connection, it typically closes
  2888  // the previous request's body, which is not optimal for zero-lengthed bodies,
  2889  // as the client would then see http.ErrBodyReadAfterClose and not 0, io.EOF.
  2890  func TestZeroLengthPostAndResponse(t *testing.T) { run(t, testZeroLengthPostAndResponse) }
  2891  
  2892  func testZeroLengthPostAndResponse(t *testing.T, mode testMode) {
  2893  	cst := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, r *Request) {
  2894  		all, err := io.ReadAll(r.Body)
  2895  		if err != nil {
  2896  			t.Fatalf("handler ReadAll: %v", err)
  2897  		}
  2898  		if len(all) != 0 {
  2899  			t.Errorf("handler got %d bytes; expected 0", len(all))
  2900  		}
  2901  		rw.Header().Set("Content-Length", "0")
  2902  	}))
  2903  
  2904  	req, err := NewRequest("POST", cst.ts.URL, strings.NewReader(""))
  2905  	if err != nil {
  2906  		t.Fatal(err)
  2907  	}
  2908  	req.ContentLength = 0
  2909  
  2910  	var resp [5]*Response
  2911  	for i := range resp {
  2912  		resp[i], err = cst.c.Do(req)
  2913  		if err != nil {
  2914  			t.Fatalf("client post #%d: %v", i, err)
  2915  		}
  2916  	}
  2917  
  2918  	for i := range resp {
  2919  		all, err := io.ReadAll(resp[i].Body)
  2920  		if err != nil {
  2921  			t.Fatalf("req #%d: client ReadAll: %v", i, err)
  2922  		}
  2923  		if len(all) != 0 {
  2924  			t.Errorf("req #%d: client got %d bytes; expected 0", i, len(all))
  2925  		}
  2926  	}
  2927  }
  2928  
  2929  func TestHandlerPanicNil(t *testing.T) {
  2930  	run(t, func(t *testing.T, mode testMode) {
  2931  		testHandlerPanic(t, false, mode, nil, nil)
  2932  	}, testNotParallel)
  2933  }
  2934  
  2935  func TestHandlerPanic(t *testing.T) {
  2936  	run(t, func(t *testing.T, mode testMode) {
  2937  		testHandlerPanic(t, false, mode, nil, "intentional death for testing")
  2938  	}, testNotParallel)
  2939  }
  2940  
  2941  func TestHandlerPanicWithHijack(t *testing.T) {
  2942  	// Only testing HTTP/1, and our http2 server doesn't support hijacking.
  2943  	run(t, func(t *testing.T, mode testMode) {
  2944  		testHandlerPanic(t, true, mode, nil, "intentional death for testing")
  2945  	}, []testMode{http1Mode})
  2946  }
  2947  
  2948  func testHandlerPanic(t *testing.T, withHijack bool, mode testMode, wrapper func(Handler) Handler, panicValue any) {
  2949  	// Direct log output to a pipe.
  2950  	//
  2951  	// We read from the pipe to verify that the handler actually caught the panic
  2952  	// and logged something.
  2953  	//
  2954  	// We use a pipe rather than a buffer, because when testing connection hijacking
  2955  	// server shutdown doesn't wait for the hijacking handler to return, so the
  2956  	// log may occur after the server has shut down.
  2957  	pr, pw := io.Pipe()
  2958  	defer pw.Close()
  2959  
  2960  	var handler Handler = HandlerFunc(func(w ResponseWriter, r *Request) {
  2961  		if withHijack {
  2962  			rwc, _, err := w.(Hijacker).Hijack()
  2963  			if err != nil {
  2964  				t.Logf("unexpected error: %v", err)
  2965  			}
  2966  			defer rwc.Close()
  2967  		}
  2968  		panic(panicValue)
  2969  	})
  2970  	if wrapper != nil {
  2971  		handler = wrapper(handler)
  2972  	}
  2973  	cst := newClientServerTest(t, mode, handler, func(ts *httptest.Server) {
  2974  		ts.Config.ErrorLog = log.New(pw, "", 0)
  2975  	})
  2976  
  2977  	// Do a blocking read on the log output pipe.
  2978  	done := make(chan bool, 1)
  2979  	go func() {
  2980  		buf := make([]byte, 4<<10)
  2981  		_, err := pr.Read(buf)
  2982  		pr.Close()
  2983  		if err != nil && err != io.EOF {
  2984  			t.Error(err)
  2985  		}
  2986  		done <- true
  2987  	}()
  2988  
  2989  	_, err := cst.c.Get(cst.ts.URL)
  2990  	if err == nil {
  2991  		t.Logf("expected an error")
  2992  	}
  2993  
  2994  	if panicValue == nil {
  2995  		return
  2996  	}
  2997  
  2998  	<-done
  2999  }
  3000  
  3001  type terrorWriter struct{ t *testing.T }
  3002  
  3003  func (w terrorWriter) Write(p []byte) (int, error) {
  3004  	w.t.Errorf("%s", p)
  3005  	return len(p), nil
  3006  }
  3007  
  3008  // Issue 16456: allow writing 0 bytes on hijacked conn to test hijack
  3009  // without any log spam.
  3010  func TestServerWriteHijackZeroBytes(t *testing.T) {
  3011  	run(t, testServerWriteHijackZeroBytes, []testMode{http1Mode})
  3012  }
  3013  func testServerWriteHijackZeroBytes(t *testing.T, mode testMode) {
  3014  	done := make(chan struct{})
  3015  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  3016  		defer close(done)
  3017  		w.(Flusher).Flush()
  3018  		conn, _, err := w.(Hijacker).Hijack()
  3019  		if err != nil {
  3020  			t.Errorf("Hijack: %v", err)
  3021  			return
  3022  		}
  3023  		defer conn.Close()
  3024  		_, err = w.Write(nil)
  3025  		if err != ErrHijacked {
  3026  			t.Errorf("Write error = %v; want ErrHijacked", err)
  3027  		}
  3028  	}), func(ts *httptest.Server) {
  3029  		ts.Config.ErrorLog = log.New(terrorWriter{t}, "Unexpected write: ", 0)
  3030  	}).ts
  3031  
  3032  	c := ts.Client()
  3033  	res, err := c.Get(ts.URL)
  3034  	if err != nil {
  3035  		t.Fatal(err)
  3036  	}
  3037  	res.Body.Close()
  3038  	<-done
  3039  }
  3040  
  3041  func TestServerNoDate(t *testing.T) {
  3042  	run(t, func(t *testing.T, mode testMode) {
  3043  		testServerNoHeader(t, mode, "Date")
  3044  	})
  3045  }
  3046  
  3047  func TestServerContentType(t *testing.T) {
  3048  	run(t, func(t *testing.T, mode testMode) {
  3049  		testServerNoHeader(t, mode, "Content-Type")
  3050  	})
  3051  }
  3052  
  3053  func testServerNoHeader(t *testing.T, mode testMode, header string) {
  3054  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  3055  		w.Header()[header] = nil
  3056  		io.WriteString(w, "<html>foo</html>") // non-empty
  3057  	}))
  3058  	res, err := cst.c.Get(cst.ts.URL)
  3059  	if err != nil {
  3060  		t.Fatal(err)
  3061  	}
  3062  	res.Body.Close()
  3063  	if got, ok := res.Header[header]; ok {
  3064  		t.Fatalf("Expected no %s header; got %q", header, got)
  3065  	}
  3066  }
  3067  
  3068  func TestStripPrefix(t *testing.T) { run(t, testStripPrefix) }
  3069  func testStripPrefix(t *testing.T, mode testMode) {
  3070  	h := HandlerFunc(func(w ResponseWriter, r *Request) {
  3071  		w.Header().Set("X-Path", r.URL.Path)
  3072  		w.Header().Set("X-RawPath", r.URL.RawPath)
  3073  	})
  3074  	ts := newClientServerTest(t, mode, StripPrefix("/foo/bar", h)).ts
  3075  
  3076  	c := ts.Client()
  3077  
  3078  	cases := []struct {
  3079  		reqPath string
  3080  		path    string // If empty we want a 404.
  3081  		rawPath string
  3082  	}{
  3083  		{"/foo/bar/qux", "/qux", ""},
  3084  		{"/foo/bar%2Fqux", "/qux", "%2Fqux"},
  3085  		{"/foo%2Fbar/qux", "", ""}, // Escaped prefix does not match.
  3086  		{"/bar", "", ""},           // No prefix match.
  3087  	}
  3088  	for _, tc := range cases {
  3089  		t.Run(tc.reqPath, func(t *testing.T) {
  3090  			res, err := c.Get(ts.URL + tc.reqPath)
  3091  			if err != nil {
  3092  				t.Fatal(err)
  3093  			}
  3094  			res.Body.Close()
  3095  			if tc.path == "" {
  3096  				if res.StatusCode != StatusNotFound {
  3097  					t.Errorf("got %q, want 404 Not Found", res.Status)
  3098  				}
  3099  				return
  3100  			}
  3101  			if res.StatusCode != StatusOK {
  3102  				t.Fatalf("got %q, want 200 OK", res.Status)
  3103  			}
  3104  			if g, w := res.Header.Get("X-Path"), tc.path; g != w {
  3105  				t.Errorf("got Path %q, want %q", g, w)
  3106  			}
  3107  			if g, w := res.Header.Get("X-RawPath"), tc.rawPath; g != w {
  3108  				t.Errorf("got RawPath %q, want %q", g, w)
  3109  			}
  3110  		})
  3111  	}
  3112  }
  3113  
  3114  // https://golang.org/issue/18952.
  3115  func TestStripPrefixNotModifyRequest(t *testing.T) {
  3116  	h := StripPrefix("/foo", NotFoundHandler())
  3117  	req := httptest.NewRequest("GET", "/foo/bar", nil)
  3118  	h.ServeHTTP(httptest.NewRecorder(), req)
  3119  	if req.URL.Path != "/foo/bar" {
  3120  		t.Errorf("StripPrefix should not modify the provided Request, but it did")
  3121  	}
  3122  }
  3123  
  3124  func TestRequestLimit(t *testing.T) { run(t, testRequestLimit) }
  3125  func testRequestLimit(t *testing.T, mode testMode) {
  3126  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  3127  		t.Fatalf("didn't expect to get request in Handler")
  3128  	}), optQuietLog)
  3129  	req, _ := NewRequest("GET", cst.ts.URL, nil)
  3130  	var bytesPerHeader = len("header12345: val12345\r\n")
  3131  	for i := 0; i < ((DefaultMaxHeaderBytes+4096)/bytesPerHeader)+1; i++ {
  3132  		req.Header.Set(fmt.Sprintf("header%05d", i), fmt.Sprintf("val%05d", i))
  3133  	}
  3134  	res, err := cst.c.Do(req)
  3135  	if res != nil {
  3136  		defer res.Body.Close()
  3137  	}
  3138  	if mode == http2Mode {
  3139  		// In HTTP/2, the result depends on a race. If the client has received the
  3140  		// server's SETTINGS before RoundTrip starts sending the request, then RoundTrip
  3141  		// will fail with an error. Otherwise, the client should receive a 431 from the
  3142  		// server.
  3143  		if err == nil && res.StatusCode != 431 {
  3144  			t.Fatalf("expected 431 response status; got: %d %s", res.StatusCode, res.Status)
  3145  		}
  3146  	} else {
  3147  		// In HTTP/1, we expect a 431 from the server.
  3148  		// Some HTTP clients may fail on this undefined behavior (server replying and
  3149  		// closing the connection while the request is still being written), but
  3150  		// we do support it (at least currently), so we expect a response below.
  3151  		if err != nil {
  3152  			t.Fatalf("Do: %v", err)
  3153  		}
  3154  		if res.StatusCode != 431 {
  3155  			t.Fatalf("expected 431 response status; got: %d %s", res.StatusCode, res.Status)
  3156  		}
  3157  	}
  3158  }
  3159  
  3160  type neverEnding byte
  3161  
  3162  func (b neverEnding) Read(p []byte) (n int, err error) {
  3163  	for i := range p {
  3164  		p[i] = byte(b)
  3165  	}
  3166  	return len(p), nil
  3167  }
  3168  
  3169  type bodyLimitReader struct {
  3170  	mu     sync.Mutex
  3171  	count  int
  3172  	limit  int
  3173  	closed chan struct{}
  3174  }
  3175  
  3176  func (r *bodyLimitReader) Read(p []byte) (int, error) {
  3177  	r.mu.Lock()
  3178  	defer r.mu.Unlock()
  3179  	select {
  3180  	case <-r.closed:
  3181  		return 0, errors.New("closed")
  3182  	default:
  3183  	}
  3184  	if r.count > r.limit {
  3185  		return 0, errors.New("at limit")
  3186  	}
  3187  	r.count += len(p)
  3188  	for i := range p {
  3189  		p[i] = 'a'
  3190  	}
  3191  	return len(p), nil
  3192  }
  3193  
  3194  func (r *bodyLimitReader) Close() error {
  3195  	r.mu.Lock()
  3196  	defer r.mu.Unlock()
  3197  	close(r.closed)
  3198  	return nil
  3199  }
  3200  
  3201  func TestRequestBodyLimit(t *testing.T) { run(t, testRequestBodyLimit) }
  3202  func testRequestBodyLimit(t *testing.T, mode testMode) {
  3203  	const limit = 1 << 20
  3204  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  3205  		r.Body = MaxBytesReader(w, r.Body, limit)
  3206  		n, err := io.Copy(io.Discard, r.Body)
  3207  		if err == nil {
  3208  			t.Errorf("expected error from io.Copy")
  3209  		}
  3210  		if n != limit {
  3211  			t.Errorf("io.Copy = %d, want %d", n, limit)
  3212  		}
  3213  		mbErr, ok := err.(*MaxBytesError)
  3214  		if !ok {
  3215  			t.Errorf("expected MaxBytesError, got %T", err)
  3216  		}
  3217  		if mbErr.Limit != limit {
  3218  			t.Errorf("MaxBytesError.Limit = %d, want %d", mbErr.Limit, limit)
  3219  		}
  3220  	}))
  3221  
  3222  	body := &bodyLimitReader{
  3223  		closed: make(chan struct{}),
  3224  		limit:  limit * 200,
  3225  	}
  3226  	req, _ := NewRequest("POST", cst.ts.URL, body)
  3227  
  3228  	// Send the POST, but don't care it succeeds or not. The
  3229  	// remote side is going to reply and then close the TCP
  3230  	// connection, and HTTP doesn't really define if that's
  3231  	// allowed or not. Some HTTP clients will get the response
  3232  	// and some (like ours, currently) will complain that the
  3233  	// request write failed, without reading the response.
  3234  	//
  3235  	// But that's okay, since what we're really testing is that
  3236  	// the remote side hung up on us before we wrote too much.
  3237  	resp, err := cst.c.Do(req)
  3238  	if err == nil {
  3239  		resp.Body.Close()
  3240  	}
  3241  	// Wait for the Transport to finish writing the request body.
  3242  	// It will close the body when done.
  3243  	<-body.closed
  3244  
  3245  	if body.count > limit*100 {
  3246  		t.Errorf("handler restricted the request body to %d bytes, but client managed to write %d",
  3247  			limit, body.count)
  3248  	}
  3249  }
  3250  
  3251  // TestClientWriteShutdown tests that if the client shuts down the write
  3252  // side of their TCP connection, the server doesn't send a 400 Bad Request.
  3253  func TestClientWriteShutdown(t *testing.T) { run(t, testClientWriteShutdown) }
  3254  func testClientWriteShutdown(t *testing.T, mode testMode) {
  3255  	if runtime.GOOS == "plan9" {
  3256  		t.Skip("skipping test; see https://golang.org/issue/17906")
  3257  	}
  3258  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {})).ts
  3259  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  3260  	if err != nil {
  3261  		t.Fatalf("Dial: %v", err)
  3262  	}
  3263  	err = conn.(*net.TCPConn).CloseWrite()
  3264  	if err != nil {
  3265  		t.Fatalf("CloseWrite: %v", err)
  3266  	}
  3267  
  3268  	bs, err := io.ReadAll(conn)
  3269  	if err != nil {
  3270  		t.Errorf("ReadAll: %v", err)
  3271  	}
  3272  	got := string(bs)
  3273  	if got != "" {
  3274  		t.Errorf("read %q from server; want nothing", got)
  3275  	}
  3276  }
  3277  
  3278  // Tests that chunked server responses that write 1 byte at a time are
  3279  // buffered before chunk headers are added, not after chunk headers.
  3280  func TestServerBufferedChunking(t *testing.T) {
  3281  	conn := new(testConn)
  3282  	conn.readBuf.Write([]byte("GET / HTTP/1.1\r\nHost: foo\r\n\r\n"))
  3283  	conn.closec = make(chan bool, 1)
  3284  	ls := &oneConnListener{conn}
  3285  	go Serve(ls, HandlerFunc(func(rw ResponseWriter, req *Request) {
  3286  		rw.(Flusher).Flush() // force the Header to be sent, in chunking mode, not counting the length
  3287  		rw.Write([]byte{'x'})
  3288  		rw.Write([]byte{'y'})
  3289  		rw.Write([]byte{'z'})
  3290  	}))
  3291  	<-conn.closec
  3292  	if !bytes.HasSuffix(conn.writeBuf.Bytes(), []byte("\r\n\r\n3\r\nxyz\r\n0\r\n\r\n")) {
  3293  		t.Errorf("response didn't end with a single 3 byte 'xyz' chunk; got:\n%q",
  3294  			conn.writeBuf.Bytes())
  3295  	}
  3296  }
  3297  
  3298  // Tests that the server flushes its response headers out when it's
  3299  // ignoring the response body and waits a bit before forcefully
  3300  // closing the TCP connection, causing the client to get a RST.
  3301  // See https://golang.org/issue/3595
  3302  func TestServerGracefulClose(t *testing.T) {
  3303  	// Not parallel: modifies the global rstAvoidanceDelay.
  3304  	run(t, testServerGracefulClose, []testMode{http1Mode}, testNotParallel)
  3305  }
  3306  func testServerGracefulClose(t *testing.T, mode testMode) {
  3307  	runTimeSensitiveTest(t, []time.Duration{
  3308  		1 * time.Millisecond,
  3309  		5 * time.Millisecond,
  3310  		10 * time.Millisecond,
  3311  		50 * time.Millisecond,
  3312  		100 * time.Millisecond,
  3313  		500 * time.Millisecond,
  3314  		time.Second,
  3315  		5 * time.Second,
  3316  	}, func(t *testing.T, timeout time.Duration) error {
  3317  		SetRSTAvoidanceDelay(t, timeout)
  3318  		t.Logf("set RST avoidance delay to %v", timeout)
  3319  
  3320  		const bodySize = 5 << 20
  3321  		req := []byte(fmt.Sprintf("POST / HTTP/1.1\r\nHost: foo.com\r\nContent-Length: %d\r\n\r\n", bodySize))
  3322  		for i := 0; i < bodySize; i++ {
  3323  			req = append(req, 'x')
  3324  		}
  3325  
  3326  		cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  3327  			Error(w, "bye", StatusUnauthorized)
  3328  		}))
  3329  		// We need to close cst explicitly here so that in-flight server
  3330  		// requests don't race with the call to SetRSTAvoidanceDelay for a retry.
  3331  		defer cst.close()
  3332  		ts := cst.ts
  3333  
  3334  		conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  3335  		if err != nil {
  3336  			return err
  3337  		}
  3338  		writeErr := make(chan error)
  3339  		go func() {
  3340  			_, err := conn.Write(req)
  3341  			writeErr <- err
  3342  		}()
  3343  		defer func() {
  3344  			conn.Close()
  3345  			// Wait for write to finish. This is a broken pipe on both
  3346  			// Darwin and Linux, but checking this isn't the point of
  3347  			// the test.
  3348  			<-writeErr
  3349  		}()
  3350  
  3351  		br := bufio.NewReader(conn)
  3352  		lineNum := 0
  3353  		for {
  3354  			line, err := br.ReadString('\n')
  3355  			if err == io.EOF {
  3356  				break
  3357  			}
  3358  			if err != nil {
  3359  				return fmt.Errorf("ReadLine: %v", err)
  3360  			}
  3361  			lineNum++
  3362  			if lineNum == 1 && !strings.Contains(line, "401 Unauthorized") {
  3363  				t.Errorf("Response line = %q; want a 401", line)
  3364  			}
  3365  		}
  3366  		return nil
  3367  	})
  3368  }
  3369  
  3370  func TestCaseSensitiveMethod(t *testing.T) { run(t, testCaseSensitiveMethod) }
  3371  func testCaseSensitiveMethod(t *testing.T, mode testMode) {
  3372  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  3373  		if r.Method != "get" {
  3374  			t.Errorf(`Got method %q; want "get"`, r.Method)
  3375  		}
  3376  	}))
  3377  	defer cst.close()
  3378  	req, _ := NewRequest("get", cst.ts.URL, nil)
  3379  	res, err := cst.c.Do(req)
  3380  	if err != nil {
  3381  		t.Error(err)
  3382  		return
  3383  	}
  3384  
  3385  	res.Body.Close()
  3386  }
  3387  
  3388  // TestContentLengthZero tests that for both an HTTP/1.0 and HTTP/1.1
  3389  // request (both keep-alive), when a Handler never writes any
  3390  // response, the net/http package adds a "Content-Length: 0" response
  3391  // header.
  3392  func TestContentLengthZero(t *testing.T) {
  3393  	run(t, testContentLengthZero, []testMode{http1Mode})
  3394  }
  3395  func testContentLengthZero(t *testing.T, mode testMode) {
  3396  	ts := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, req *Request) {})).ts
  3397  
  3398  	for _, version := range []string{"HTTP/1.0", "HTTP/1.1"} {
  3399  		conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  3400  		if err != nil {
  3401  			t.Fatalf("error dialing: %v", err)
  3402  		}
  3403  		_, err = fmt.Fprintf(conn, "GET / %v\r\nConnection: keep-alive\r\nHost: foo\r\n\r\n", version)
  3404  		if err != nil {
  3405  			t.Fatalf("error writing: %v", err)
  3406  		}
  3407  		req, _ := NewRequest("GET", "/", nil)
  3408  		res, err := ReadResponse(bufio.NewReader(conn), req)
  3409  		if err != nil {
  3410  			t.Fatalf("error reading response: %v", err)
  3411  		}
  3412  		if te := res.TransferEncoding; len(te) > 0 {
  3413  			t.Errorf("For version %q, Transfer-Encoding = %q; want none", version, te)
  3414  		}
  3415  		if cl := res.ContentLength; cl != 0 {
  3416  			t.Errorf("For version %q, Content-Length = %v; want 0", version, cl)
  3417  		}
  3418  		conn.Close()
  3419  	}
  3420  }
  3421  
  3422  func TestCloseNotifier(t *testing.T) {
  3423  	run(t, testCloseNotifier, []testMode{http1Mode})
  3424  }
  3425  func testCloseNotifier(t *testing.T, mode testMode) {
  3426  	gotReq := make(chan bool, 1)
  3427  	sawClose := make(chan bool, 1)
  3428  	ts := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, req *Request) {
  3429  		gotReq <- true
  3430  		cc := rw.(CloseNotifier).CloseNotify()
  3431  		<-cc
  3432  		sawClose <- true
  3433  	})).ts
  3434  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  3435  	if err != nil {
  3436  		t.Fatalf("error dialing: %v", err)
  3437  	}
  3438  	diec := make(chan bool)
  3439  	go func() {
  3440  		_, err = fmt.Fprintf(conn, "GET / HTTP/1.1\r\nConnection: keep-alive\r\nHost: foo\r\n\r\n")
  3441  		if err != nil {
  3442  			t.Error(err)
  3443  			return
  3444  		}
  3445  		<-diec
  3446  		conn.Close()
  3447  	}()
  3448  For:
  3449  	for {
  3450  		select {
  3451  		case <-gotReq:
  3452  			diec <- true
  3453  		case <-sawClose:
  3454  			break For
  3455  		}
  3456  	}
  3457  	ts.Close()
  3458  }
  3459  
  3460  // Tests that a pipelined request does not cause the first request's
  3461  // Handler's CloseNotify channel to fire.
  3462  //
  3463  // Issue 13165 (where it used to deadlock), but behavior changed in Issue 23921.
  3464  func TestCloseNotifierPipelined(t *testing.T) {
  3465  	run(t, testCloseNotifierPipelined, []testMode{http1Mode})
  3466  }
  3467  func testCloseNotifierPipelined(t *testing.T, mode testMode) {
  3468  	gotReq := make(chan bool, 2)
  3469  	sawClose := make(chan bool, 2)
  3470  	ts := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, req *Request) {
  3471  		gotReq <- true
  3472  		cc := rw.(CloseNotifier).CloseNotify()
  3473  		select {
  3474  		case <-cc:
  3475  			t.Error("unexpected CloseNotify")
  3476  		case <-time.After(100 * time.Millisecond):
  3477  		}
  3478  		sawClose <- true
  3479  	})).ts
  3480  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  3481  	if err != nil {
  3482  		t.Fatalf("error dialing: %v", err)
  3483  	}
  3484  	diec := make(chan bool, 1)
  3485  	defer close(diec)
  3486  	go func() {
  3487  		const req = "GET / HTTP/1.1\r\nConnection: keep-alive\r\nHost: foo\r\n\r\n"
  3488  		_, err = io.WriteString(conn, req+req) // two requests
  3489  		if err != nil {
  3490  			t.Error(err)
  3491  			return
  3492  		}
  3493  		<-diec
  3494  		conn.Close()
  3495  	}()
  3496  	reqs := 0
  3497  	closes := 0
  3498  	for {
  3499  		select {
  3500  		case <-gotReq:
  3501  			reqs++
  3502  			if reqs > 2 {
  3503  				t.Fatal("too many requests")
  3504  			}
  3505  		case <-sawClose:
  3506  			closes++
  3507  			if closes > 1 {
  3508  				return
  3509  			}
  3510  		}
  3511  	}
  3512  }
  3513  
  3514  func TestCloseNotifierChanLeak(t *testing.T) {
  3515  	defer afterTest(t)
  3516  	req := reqBytes("GET / HTTP/1.0\nHost: golang.org")
  3517  	for i := 0; i < 20; i++ {
  3518  		var output bytes.Buffer
  3519  		conn := &rwTestConn{
  3520  			Reader: bytes.NewReader(req),
  3521  			Writer: &output,
  3522  			closec: make(chan bool, 1),
  3523  		}
  3524  		ln := &oneConnListener{conn: conn}
  3525  		handler := HandlerFunc(func(rw ResponseWriter, r *Request) {
  3526  			// Ignore the return value and never read from
  3527  			// it, testing that we don't leak goroutines
  3528  			// on the sending side:
  3529  			_ = rw.(CloseNotifier).CloseNotify()
  3530  		})
  3531  		go Serve(ln, handler)
  3532  		<-conn.closec
  3533  	}
  3534  }
  3535  
  3536  // Tests that we can use CloseNotifier in one request, and later call Hijack
  3537  // on a second request on the same connection.
  3538  //
  3539  // It also tests that the connReader stitches together its background
  3540  // 1-byte read for CloseNotifier when CloseNotifier doesn't fire with
  3541  // the rest of the second HTTP later.
  3542  //
  3543  // Issue 9763.
  3544  // HTTP/1-only test. (http2 doesn't have Hijack)
  3545  func TestHijackAfterCloseNotifier(t *testing.T) {
  3546  	run(t, testHijackAfterCloseNotifier, []testMode{http1Mode})
  3547  }
  3548  func testHijackAfterCloseNotifier(t *testing.T, mode testMode) {
  3549  	script := make(chan string, 2)
  3550  	script <- "closenotify"
  3551  	script <- "hijack"
  3552  	close(script)
  3553  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  3554  		plan := <-script
  3555  		switch plan {
  3556  		default:
  3557  			panic("bogus plan; too many requests")
  3558  		case "closenotify":
  3559  			w.(CloseNotifier).CloseNotify() // discard result
  3560  			w.Header().Set("X-Addr", r.RemoteAddr)
  3561  		case "hijack":
  3562  			c, _, err := w.(Hijacker).Hijack()
  3563  			if err != nil {
  3564  				t.Errorf("Hijack in Handler: %v", err)
  3565  				return
  3566  			}
  3567  			if _, ok := c.(*net.TCPConn); !ok {
  3568  				// Verify it's not wrapped in some type.
  3569  				// Not strictly a go1 compat issue, but in practice it probably is.
  3570  				t.Errorf("type of hijacked conn is %T; want *net.TCPConn", c)
  3571  			}
  3572  			fmt.Fprintf(c, "HTTP/1.0 200 OK\r\nX-Addr: %v\r\nContent-Length: 0\r\n\r\n", r.RemoteAddr)
  3573  			c.Close()
  3574  			return
  3575  		}
  3576  	})).ts
  3577  	res1, err := ts.Client().Get(ts.URL)
  3578  	if err != nil {
  3579  		log.Fatal(err)
  3580  	}
  3581  	res2, err := ts.Client().Get(ts.URL)
  3582  	if err != nil {
  3583  		log.Fatal(err)
  3584  	}
  3585  	addr1 := res1.Header.Get("X-Addr")
  3586  	addr2 := res2.Header.Get("X-Addr")
  3587  	if addr1 == "" || addr1 != addr2 {
  3588  		t.Errorf("addr1, addr2 = %q, %q; want same", addr1, addr2)
  3589  	}
  3590  }
  3591  
  3592  func TestHijackBeforeRequestBodyRead(t *testing.T) {
  3593  	run(t, testHijackBeforeRequestBodyRead, []testMode{http1Mode})
  3594  }
  3595  func testHijackBeforeRequestBodyRead(t *testing.T, mode testMode) {
  3596  	var requestBody = bytes.Repeat([]byte("a"), 1<<20)
  3597  	bodyOkay := make(chan bool, 1)
  3598  	gotCloseNotify := make(chan bool, 1)
  3599  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  3600  		defer close(bodyOkay) // caller will read false if nothing else
  3601  
  3602  		reqBody := r.Body
  3603  		r.Body = nil // to test that server.go doesn't use this value.
  3604  
  3605  		gone := w.(CloseNotifier).CloseNotify()
  3606  		slurp, err := io.ReadAll(reqBody)
  3607  		if err != nil {
  3608  			t.Errorf("Body read: %v", err)
  3609  			return
  3610  		}
  3611  		if len(slurp) != len(requestBody) {
  3612  			t.Errorf("Backend read %d request body bytes; want %d", len(slurp), len(requestBody))
  3613  			return
  3614  		}
  3615  		if !bytes.Equal(slurp, requestBody) {
  3616  			t.Error("Backend read wrong request body.") // 1MB; omitting details
  3617  			return
  3618  		}
  3619  		bodyOkay <- true
  3620  		<-gone
  3621  		gotCloseNotify <- true
  3622  	})).ts
  3623  
  3624  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  3625  	if err != nil {
  3626  		t.Fatal(err)
  3627  	}
  3628  	defer conn.Close()
  3629  
  3630  	fmt.Fprintf(conn, "POST / HTTP/1.1\r\nHost: foo\r\nContent-Length: %d\r\n\r\n%s",
  3631  		len(requestBody), requestBody)
  3632  	if !<-bodyOkay {
  3633  		// already failed.
  3634  		return
  3635  	}
  3636  	conn.Close()
  3637  	<-gotCloseNotify
  3638  }
  3639  
  3640  func TestOptions(t *testing.T) { run(t, testOptions, []testMode{http1Mode}) }
  3641  func testOptions(t *testing.T, mode testMode) {
  3642  	uric := make(chan string, 2) // only expect 1, but leave space for 2
  3643  	mux := NewServeMux()
  3644  	mux.HandleFunc("/", func(w ResponseWriter, r *Request) {
  3645  		uric <- r.RequestURI
  3646  	})
  3647  	ts := newClientServerTest(t, mode, mux).ts
  3648  
  3649  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  3650  	if err != nil {
  3651  		t.Fatal(err)
  3652  	}
  3653  	defer conn.Close()
  3654  
  3655  	// An OPTIONS * request should succeed.
  3656  	_, err = conn.Write([]byte("OPTIONS * HTTP/1.1\r\nHost: foo.com\r\n\r\n"))
  3657  	if err != nil {
  3658  		t.Fatal(err)
  3659  	}
  3660  	br := bufio.NewReader(conn)
  3661  	res, err := ReadResponse(br, &Request{Method: "OPTIONS"})
  3662  	if err != nil {
  3663  		t.Fatal(err)
  3664  	}
  3665  	if res.StatusCode != 200 {
  3666  		t.Errorf("Got non-200 response to OPTIONS *: %#v", res)
  3667  	}
  3668  
  3669  	// A GET * request on a ServeMux should fail.
  3670  	_, err = conn.Write([]byte("GET * HTTP/1.1\r\nHost: foo.com\r\n\r\n"))
  3671  	if err != nil {
  3672  		t.Fatal(err)
  3673  	}
  3674  	res, err = ReadResponse(br, &Request{Method: "GET"})
  3675  	if err != nil {
  3676  		t.Fatal(err)
  3677  	}
  3678  	if res.StatusCode != 400 {
  3679  		t.Errorf("Got non-400 response to GET *: %#v", res)
  3680  	}
  3681  
  3682  	res, err = Get(ts.URL + "/second")
  3683  	if err != nil {
  3684  		t.Fatal(err)
  3685  	}
  3686  	res.Body.Close()
  3687  	if got := <-uric; got != "/second" {
  3688  		t.Errorf("Handler saw request for %q; want /second", got)
  3689  	}
  3690  }
  3691  
  3692  func TestOptionsHandler(t *testing.T) { run(t, testOptionsHandler, []testMode{http1Mode}) }
  3693  func testOptionsHandler(t *testing.T, mode testMode) {
  3694  	rc := make(chan *Request, 1)
  3695  
  3696  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  3697  		rc <- r
  3698  	}), func(ts *httptest.Server) {
  3699  		ts.Config.DisableGeneralOptionsHandler = true
  3700  	}).ts
  3701  
  3702  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  3703  	if err != nil {
  3704  		t.Fatal(err)
  3705  	}
  3706  	defer conn.Close()
  3707  
  3708  	_, err = conn.Write([]byte("OPTIONS * HTTP/1.1\r\nHost: foo.com\r\n\r\n"))
  3709  	if err != nil {
  3710  		t.Fatal(err)
  3711  	}
  3712  
  3713  	if got := <-rc; got.Method != "OPTIONS" || got.RequestURI != "*" {
  3714  		t.Errorf("Expected OPTIONS * request, got %v", got)
  3715  	}
  3716  }
  3717  
  3718  // Tests regarding the ordering of Write, WriteHeader, Header, and
  3719  // Flush calls. In Go 1.0, rw.WriteHeader immediately flushed the
  3720  // (*response).header to the wire. In Go 1.1, the actual wire flush is
  3721  // delayed, so we could maybe tack on a Content-Length and better
  3722  // Content-Type after we see more (or all) of the output. To preserve
  3723  // compatibility with Go 1, we need to be careful to track which
  3724  // headers were live at the time of WriteHeader, so we write the same
  3725  // ones, even if the handler modifies them (~erroneously) after the
  3726  // first Write.
  3727  func TestHeaderToWire(t *testing.T) {
  3728  	tests := []struct {
  3729  		name    string
  3730  		handler func(ResponseWriter, *Request)
  3731  		check   func(got, logs string) error
  3732  	}{
  3733  		{
  3734  			name: "write without Header",
  3735  			handler: func(rw ResponseWriter, r *Request) {
  3736  				rw.Write([]byte("hello world"))
  3737  			},
  3738  			check: func(got, logs string) error {
  3739  				if !strings.Contains(got, "Content-Length:") {
  3740  					return errors.New("no content-length")
  3741  				}
  3742  				if !strings.Contains(got, "Content-Type: text/plain") {
  3743  					return errors.New("no content-type")
  3744  				}
  3745  				return nil
  3746  			},
  3747  		},
  3748  		{
  3749  			name: "Header mutation before write",
  3750  			handler: func(rw ResponseWriter, r *Request) {
  3751  				h := rw.Header()
  3752  				h.Set("Content-Type", "some/type")
  3753  				rw.Write([]byte("hello world"))
  3754  				h.Set("Too-Late", "bogus")
  3755  			},
  3756  			check: func(got, logs string) error {
  3757  				if !strings.Contains(got, "Content-Length:") {
  3758  					return errors.New("no content-length")
  3759  				}
  3760  				if !strings.Contains(got, "Content-Type: some/type") {
  3761  					return errors.New("wrong content-type")
  3762  				}
  3763  				if strings.Contains(got, "Too-Late") {
  3764  					return errors.New("don't want too-late header")
  3765  				}
  3766  				return nil
  3767  			},
  3768  		},
  3769  		{
  3770  			name: "write then useless Header mutation",
  3771  			handler: func(rw ResponseWriter, r *Request) {
  3772  				rw.Write([]byte("hello world"))
  3773  				rw.Header().Set("Too-Late", "Write already wrote headers")
  3774  			},
  3775  			check: func(got, logs string) error {
  3776  				if strings.Contains(got, "Too-Late") {
  3777  					return errors.New("header appeared from after WriteHeader")
  3778  				}
  3779  				return nil
  3780  			},
  3781  		},
  3782  		{
  3783  			name: "flush then write",
  3784  			handler: func(rw ResponseWriter, r *Request) {
  3785  				rw.(Flusher).Flush()
  3786  				rw.Write([]byte("post-flush"))
  3787  				rw.Header().Set("Too-Late", "Write already wrote headers")
  3788  			},
  3789  			check: func(got, logs string) error {
  3790  				if !strings.Contains(got, "Transfer-Encoding: chunked") {
  3791  					return errors.New("not chunked")
  3792  				}
  3793  				if strings.Contains(got, "Too-Late") {
  3794  					return errors.New("header appeared from after WriteHeader")
  3795  				}
  3796  				return nil
  3797  			},
  3798  		},
  3799  		{
  3800  			name: "header then flush",
  3801  			handler: func(rw ResponseWriter, r *Request) {
  3802  				rw.Header().Set("Content-Type", "some/type")
  3803  				rw.(Flusher).Flush()
  3804  				rw.Write([]byte("post-flush"))
  3805  				rw.Header().Set("Too-Late", "Write already wrote headers")
  3806  			},
  3807  			check: func(got, logs string) error {
  3808  				if !strings.Contains(got, "Transfer-Encoding: chunked") {
  3809  					return errors.New("not chunked")
  3810  				}
  3811  				if strings.Contains(got, "Too-Late") {
  3812  					return errors.New("header appeared from after WriteHeader")
  3813  				}
  3814  				if !strings.Contains(got, "Content-Type: some/type") {
  3815  					return errors.New("wrong content-type")
  3816  				}
  3817  				return nil
  3818  			},
  3819  		},
  3820  		{
  3821  			name: "sniff-on-first-write content-type",
  3822  			handler: func(rw ResponseWriter, r *Request) {
  3823  				rw.Write([]byte("<html><head></head><body>some html</body></html>"))
  3824  				rw.Header().Set("Content-Type", "x/wrong")
  3825  			},
  3826  			check: func(got, logs string) error {
  3827  				if !strings.Contains(got, "Content-Type: text/html") {
  3828  					return errors.New("wrong content-type; want html")
  3829  				}
  3830  				return nil
  3831  			},
  3832  		},
  3833  		{
  3834  			name: "explicit content-type wins",
  3835  			handler: func(rw ResponseWriter, r *Request) {
  3836  				rw.Header().Set("Content-Type", "some/type")
  3837  				rw.Write([]byte("<html><head></head><body>some html</body></html>"))
  3838  			},
  3839  			check: func(got, logs string) error {
  3840  				if !strings.Contains(got, "Content-Type: some/type") {
  3841  					return errors.New("wrong content-type; want html")
  3842  				}
  3843  				return nil
  3844  			},
  3845  		},
  3846  		{
  3847  			name: "empty handler",
  3848  			handler: func(rw ResponseWriter, r *Request) {
  3849  			},
  3850  			check: func(got, logs string) error {
  3851  				if !strings.Contains(got, "Content-Length: 0") {
  3852  					return errors.New("want 0 content-length")
  3853  				}
  3854  				return nil
  3855  			},
  3856  		},
  3857  		{
  3858  			name: "only Header, no write",
  3859  			handler: func(rw ResponseWriter, r *Request) {
  3860  				rw.Header().Set("Some-Header", "some-value")
  3861  			},
  3862  			check: func(got, logs string) error {
  3863  				if !strings.Contains(got, "Some-Header") {
  3864  					return errors.New("didn't get header")
  3865  				}
  3866  				return nil
  3867  			},
  3868  		},
  3869  		{
  3870  			name: "WriteHeader call",
  3871  			handler: func(rw ResponseWriter, r *Request) {
  3872  				rw.WriteHeader(404)
  3873  				rw.Header().Set("Too-Late", "some-value")
  3874  			},
  3875  			check: func(got, logs string) error {
  3876  				if !strings.Contains(got, "404") {
  3877  					return errors.New("wrong status")
  3878  				}
  3879  				if strings.Contains(got, "Too-Late") {
  3880  					return errors.New("shouldn't have seen Too-Late")
  3881  				}
  3882  				return nil
  3883  			},
  3884  		},
  3885  	}
  3886  	for _, tc := range tests {
  3887  		ht := newHandlerTest(HandlerFunc(tc.handler))
  3888  		got := ht.rawResponse("GET / HTTP/1.1\nHost: golang.org")
  3889  		logs := ht.logbuf.String()
  3890  		if err := tc.check(got, logs); err != nil {
  3891  			t.Errorf("%s: %v\nGot response:\n%s\n\n%s", tc.name, err, got, logs)
  3892  		}
  3893  	}
  3894  }
  3895  
  3896  type errorListener struct {
  3897  	errs []error
  3898  }
  3899  
  3900  func (l *errorListener) Accept() (c net.Conn, err error) {
  3901  	if len(l.errs) == 0 {
  3902  		return nil, io.EOF
  3903  	}
  3904  	err = l.errs[0]
  3905  	l.errs = l.errs[1:]
  3906  	return
  3907  }
  3908  
  3909  func (l *errorListener) Close() error {
  3910  	return nil
  3911  }
  3912  
  3913  func (l *errorListener) Addr() net.Addr {
  3914  	return dummyAddr("test-address")
  3915  }
  3916  
  3917  func TestAcceptMaxFds(t *testing.T) {
  3918  	setParallel(t)
  3919  
  3920  	ln := &errorListener{[]error{
  3921  		&net.OpError{
  3922  			Op:  "accept",
  3923  			Err: syscall.EMFILE,
  3924  		}}}
  3925  	server := &Server{
  3926  		Handler:  HandlerFunc(HandlerFunc(func(ResponseWriter, *Request) {})),
  3927  		ErrorLog: log.New(io.Discard, "", 0), // noisy otherwise
  3928  	}
  3929  	err := server.Serve(ln)
  3930  	if err != io.EOF {
  3931  		t.Errorf("got error %v, want EOF", err)
  3932  	}
  3933  }
  3934  
  3935  func TestWriteAfterHijack(t *testing.T) {
  3936  	req := reqBytes("GET / HTTP/1.1\nHost: golang.org")
  3937  	var buf strings.Builder
  3938  	wrotec := make(chan bool, 1)
  3939  	conn := &rwTestConn{
  3940  		Reader: bytes.NewReader(req),
  3941  		Writer: &buf,
  3942  		closec: make(chan bool, 1),
  3943  	}
  3944  	handler := HandlerFunc(func(rw ResponseWriter, r *Request) {
  3945  		conn, bufrw, err := rw.(Hijacker).Hijack()
  3946  		if err != nil {
  3947  			t.Error(err)
  3948  			return
  3949  		}
  3950  		go func() {
  3951  			bufrw.Write([]byte("[hijack-to-bufw]"))
  3952  			bufrw.Flush()
  3953  			conn.Write([]byte("[hijack-to-conn]"))
  3954  			conn.Close()
  3955  			wrotec <- true
  3956  		}()
  3957  	})
  3958  	ln := &oneConnListener{conn: conn}
  3959  	go Serve(ln, handler)
  3960  	<-conn.closec
  3961  	<-wrotec
  3962  	if g, w := buf.String(), "[hijack-to-bufw][hijack-to-conn]"; g != w {
  3963  		t.Errorf("wrote %q; want %q", g, w)
  3964  	}
  3965  }
  3966  
  3967  func TestDoubleHijack(t *testing.T) {
  3968  	req := reqBytes("GET / HTTP/1.1\nHost: golang.org")
  3969  	var buf bytes.Buffer
  3970  	conn := &rwTestConn{
  3971  		Reader: bytes.NewReader(req),
  3972  		Writer: &buf,
  3973  		closec: make(chan bool, 1),
  3974  	}
  3975  	handler := HandlerFunc(func(rw ResponseWriter, r *Request) {
  3976  		conn, _, err := rw.(Hijacker).Hijack()
  3977  		if err != nil {
  3978  			t.Error(err)
  3979  			return
  3980  		}
  3981  		_, _, err = rw.(Hijacker).Hijack()
  3982  		if err == nil {
  3983  			t.Errorf("got err = nil;  want err != nil")
  3984  		}
  3985  		conn.Close()
  3986  	})
  3987  	ln := &oneConnListener{conn: conn}
  3988  	go Serve(ln, handler)
  3989  	<-conn.closec
  3990  }
  3991  
  3992  // https://golang.org/issue/5955
  3993  // Note that this does not test the "request too large"
  3994  // exit path from the http server. This is intentional;
  3995  // not sending Connection: close is just a minor wire
  3996  // optimization and is pointless if dealing with a
  3997  // badly behaved client.
  3998  func TestHTTP10ConnectionHeader(t *testing.T) {
  3999  	run(t, testHTTP10ConnectionHeader, []testMode{http1Mode})
  4000  }
  4001  func testHTTP10ConnectionHeader(t *testing.T, mode testMode) {
  4002  	mux := NewServeMux()
  4003  	mux.Handle("/", HandlerFunc(func(ResponseWriter, *Request) {}))
  4004  	ts := newClientServerTest(t, mode, mux).ts
  4005  
  4006  	// net/http uses HTTP/1.1 for requests, so write requests manually
  4007  	tests := []struct {
  4008  		req    string   // raw http request
  4009  		expect []string // expected Connection header(s)
  4010  	}{
  4011  		{
  4012  			req:    "GET / HTTP/1.0\r\n\r\n",
  4013  			expect: nil,
  4014  		},
  4015  		{
  4016  			req:    "OPTIONS * HTTP/1.0\r\n\r\n",
  4017  			expect: nil,
  4018  		},
  4019  		{
  4020  			req:    "GET / HTTP/1.0\r\nConnection: keep-alive\r\n\r\n",
  4021  			expect: []string{"keep-alive"},
  4022  		},
  4023  	}
  4024  
  4025  	for _, tt := range tests {
  4026  		conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  4027  		if err != nil {
  4028  			t.Fatal("dial err:", err)
  4029  		}
  4030  
  4031  		_, err = fmt.Fprint(conn, tt.req)
  4032  		if err != nil {
  4033  			t.Fatal("conn write err:", err)
  4034  		}
  4035  
  4036  		resp, err := ReadResponse(bufio.NewReader(conn), &Request{Method: "GET"})
  4037  		if err != nil {
  4038  			t.Fatal("ReadResponse err:", err)
  4039  		}
  4040  		conn.Close()
  4041  		resp.Body.Close()
  4042  
  4043  		got := resp.Header["Connection"]
  4044  		if !slices.Equal(got, tt.expect) {
  4045  			t.Errorf("wrong Connection headers for request %q. Got %q expect %q", tt.req, got, tt.expect)
  4046  		}
  4047  	}
  4048  }
  4049  
  4050  // See golang.org/issue/5660
  4051  func TestServerReaderFromOrder(t *testing.T) { run(t, testServerReaderFromOrder) }
  4052  func testServerReaderFromOrder(t *testing.T, mode testMode) {
  4053  	pr, pw := io.Pipe()
  4054  	const size = 3 << 20
  4055  	cst := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, req *Request) {
  4056  		rw.Header().Set("Content-Type", "text/plain") // prevent sniffing path
  4057  		done := make(chan bool)
  4058  		go func() {
  4059  			io.Copy(rw, pr)
  4060  			close(done)
  4061  		}()
  4062  		time.Sleep(25 * time.Millisecond) // give Copy a chance to break things
  4063  		n, err := io.Copy(io.Discard, req.Body)
  4064  		if err != nil {
  4065  			t.Errorf("handler Copy: %v", err)
  4066  			return
  4067  		}
  4068  		if n != size {
  4069  			t.Errorf("handler Copy = %d; want %d", n, size)
  4070  		}
  4071  		pw.Write([]byte("hi"))
  4072  		pw.Close()
  4073  		<-done
  4074  	}))
  4075  
  4076  	req, err := NewRequest("POST", cst.ts.URL, io.LimitReader(neverEnding('a'), size))
  4077  	if err != nil {
  4078  		t.Fatal(err)
  4079  	}
  4080  	res, err := cst.c.Do(req)
  4081  	if err != nil {
  4082  		t.Fatal(err)
  4083  	}
  4084  	all, err := io.ReadAll(res.Body)
  4085  	if err != nil {
  4086  		t.Fatal(err)
  4087  	}
  4088  	res.Body.Close()
  4089  	if string(all) != "hi" {
  4090  		t.Errorf("Body = %q; want hi", all)
  4091  	}
  4092  }
  4093  
  4094  // Issue 6157, Issue 6685
  4095  func TestCodesPreventingContentTypeAndBody(t *testing.T) {
  4096  	for _, code := range []int{StatusNotModified, StatusNoContent} {
  4097  		ht := newHandlerTest(HandlerFunc(func(w ResponseWriter, r *Request) {
  4098  			if r.URL.Path == "/header" {
  4099  				w.Header().Set("Content-Length", "123")
  4100  			}
  4101  			w.WriteHeader(code)
  4102  			if r.URL.Path == "/more" {
  4103  				w.Write([]byte("stuff"))
  4104  			}
  4105  		}))
  4106  		for _, req := range []string{
  4107  			"GET / HTTP/1.0",
  4108  			"GET /header HTTP/1.0",
  4109  			"GET /more HTTP/1.0",
  4110  			"GET / HTTP/1.1\nHost: foo",
  4111  			"GET /header HTTP/1.1\nHost: foo",
  4112  			"GET /more HTTP/1.1\nHost: foo",
  4113  		} {
  4114  			got := ht.rawResponse(req)
  4115  			wantStatus := fmt.Sprintf("%d %s", code, StatusText(code))
  4116  			if !strings.Contains(got, wantStatus) {
  4117  				t.Errorf("Code %d: Wanted %q Modified for %q: %s", code, wantStatus, req, got)
  4118  			} else if strings.Contains(got, "Content-Length") {
  4119  				t.Errorf("Code %d: Got a Content-Length from %q: %s", code, req, got)
  4120  			} else if strings.Contains(got, "stuff") {
  4121  				t.Errorf("Code %d: Response contains a body from %q: %s", code, req, got)
  4122  			}
  4123  		}
  4124  	}
  4125  }
  4126  
  4127  func TestContentTypeOkayOn204(t *testing.T) {
  4128  	ht := newHandlerTest(HandlerFunc(func(w ResponseWriter, r *Request) {
  4129  		w.Header().Set("Content-Length", "123") // suppressed
  4130  		w.Header().Set("Content-Type", "foo/bar")
  4131  		w.WriteHeader(204)
  4132  	}))
  4133  	got := ht.rawResponse("GET / HTTP/1.1\nHost: foo")
  4134  	if !strings.Contains(got, "Content-Type: foo/bar") {
  4135  		t.Errorf("Response = %q; want Content-Type: foo/bar", got)
  4136  	}
  4137  	if strings.Contains(got, "Content-Length: 123") {
  4138  		t.Errorf("Response = %q; don't want a Content-Length", got)
  4139  	}
  4140  }
  4141  
  4142  // Issue 6995
  4143  // A server Handler can receive a Request, and then turn around and
  4144  // give a copy of that Request.Body out to the Transport (e.g. any
  4145  // proxy).  So then two people own that Request.Body (both the server
  4146  // and the http client), and both think they can close it on failure.
  4147  // Therefore, all incoming server requests Bodies need to be thread-safe.
  4148  func TestTransportAndServerSharedBodyRace(t *testing.T) {
  4149  	run(t, testTransportAndServerSharedBodyRace, testNotParallel)
  4150  }
  4151  func testTransportAndServerSharedBodyRace(t *testing.T, mode testMode) {
  4152  	// The proxy server in the middle of the stack for this test potentially
  4153  	// from its handler after only reading half of the body.
  4154  	// That can trigger https://go.dev/issue/3595, which is otherwise
  4155  	// irrelevant to this test.
  4156  	runTimeSensitiveTest(t, []time.Duration{
  4157  		1 * time.Millisecond,
  4158  		5 * time.Millisecond,
  4159  		10 * time.Millisecond,
  4160  		50 * time.Millisecond,
  4161  		100 * time.Millisecond,
  4162  		500 * time.Millisecond,
  4163  		time.Second,
  4164  		5 * time.Second,
  4165  	}, func(t *testing.T, timeout time.Duration) error {
  4166  		SetRSTAvoidanceDelay(t, timeout)
  4167  		t.Logf("set RST avoidance delay to %v", timeout)
  4168  
  4169  		const bodySize = 1 << 20
  4170  
  4171  		var wg sync.WaitGroup
  4172  		backend := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, req *Request) {
  4173  			// Work around https://go.dev/issue/38370: clientServerTest uses
  4174  			// an httptest.Server under the hood, and in HTTP/2 mode it does not always
  4175  			// “[block] until all outstanding requests on this server have completed”,
  4176  			// causing the call to Logf below to race with the end of the test.
  4177  			//
  4178  			// Since the client doesn't cancel the request until we have copied half
  4179  			// the body, this call to add happens before the test is cleaned up,
  4180  			// preventing the race.
  4181  			wg.Add(1)
  4182  			defer wg.Done()
  4183  
  4184  			n, err := io.CopyN(rw, req.Body, bodySize)
  4185  			t.Logf("backend CopyN: %v, %v", n, err)
  4186  			<-req.Context().Done()
  4187  		}))
  4188  		// We need to close explicitly here so that in-flight server
  4189  		// requests don't race with the call to SetRSTAvoidanceDelay for a retry.
  4190  		defer func() {
  4191  			wg.Wait()
  4192  			backend.close()
  4193  		}()
  4194  
  4195  		var proxy *clientServerTest
  4196  		proxy = newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, req *Request) {
  4197  			req2, _ := NewRequest("POST", backend.ts.URL, req.Body)
  4198  			req2.ContentLength = bodySize
  4199  			cancel := make(chan struct{})
  4200  			req2.Cancel = cancel
  4201  
  4202  			bresp, err := proxy.c.Do(req2)
  4203  			if err != nil {
  4204  				t.Errorf("Proxy outbound request: %v", err)
  4205  				return
  4206  			}
  4207  			_, err = io.CopyN(io.Discard, bresp.Body, bodySize/2)
  4208  			if err != nil {
  4209  				t.Errorf("Proxy copy error: %v", err)
  4210  				return
  4211  			}
  4212  			t.Cleanup(func() { bresp.Body.Close() })
  4213  
  4214  			// Try to cause a race. Canceling the client request will cause the client
  4215  			// transport to close req2.Body. Returning from the server handler will
  4216  			// cause the server to close req.Body. Since they are the same underlying
  4217  			// ReadCloser, that will result in concurrent calls to Close (and possibly a
  4218  			// Read concurrent with a Close).
  4219  			if mode == http2Mode {
  4220  				close(cancel)
  4221  			} else {
  4222  				proxy.c.Transport.(*Transport).CancelRequest(req2)
  4223  			}
  4224  			rw.Write([]byte("OK"))
  4225  		}))
  4226  		defer proxy.close()
  4227  
  4228  		req, _ := NewRequest("POST", proxy.ts.URL, io.LimitReader(neverEnding('a'), bodySize))
  4229  		res, err := proxy.c.Do(req)
  4230  		if err != nil {
  4231  			return fmt.Errorf("original request: %v", err)
  4232  		}
  4233  		res.Body.Close()
  4234  		return nil
  4235  	})
  4236  }
  4237  
  4238  // Test that a hanging Request.Body.Read from another goroutine can't
  4239  // cause the Handler goroutine's Request.Body.Close to block.
  4240  // See issue 7121.
  4241  func TestRequestBodyCloseDoesntBlock(t *testing.T) {
  4242  	run(t, testRequestBodyCloseDoesntBlock, []testMode{http1Mode})
  4243  }
  4244  func testRequestBodyCloseDoesntBlock(t *testing.T, mode testMode) {
  4245  	if testing.Short() {
  4246  		t.Skip("skipping in -short mode")
  4247  	}
  4248  
  4249  	readErrCh := make(chan error, 1)
  4250  	errCh := make(chan error, 2)
  4251  
  4252  	server := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, req *Request) {
  4253  		go func(body io.Reader) {
  4254  			_, err := body.Read(make([]byte, 100))
  4255  			readErrCh <- err
  4256  		}(req.Body)
  4257  		time.Sleep(500 * time.Millisecond)
  4258  	})).ts
  4259  
  4260  	closeConn := make(chan bool)
  4261  	defer close(closeConn)
  4262  	go func() {
  4263  		conn, err := net.Dial("tcp", server.Listener.Addr().String())
  4264  		if err != nil {
  4265  			errCh <- err
  4266  			return
  4267  		}
  4268  		defer conn.Close()
  4269  		_, err = conn.Write([]byte("POST / HTTP/1.1\r\nConnection: close\r\nHost: foo\r\nContent-Length: 100000\r\n\r\n"))
  4270  		if err != nil {
  4271  			errCh <- err
  4272  			return
  4273  		}
  4274  		// And now just block, making the server block on our
  4275  		// 100000 bytes of body that will never arrive.
  4276  		<-closeConn
  4277  	}()
  4278  	select {
  4279  	case err := <-readErrCh:
  4280  		if err == nil {
  4281  			t.Error("Read was nil. Expected error.")
  4282  		}
  4283  	case err := <-errCh:
  4284  		t.Error(err)
  4285  	}
  4286  }
  4287  
  4288  // test that ResponseWriter implements io.StringWriter.
  4289  func TestResponseWriterWriteString(t *testing.T) {
  4290  	okc := make(chan bool, 1)
  4291  	ht := newHandlerTest(HandlerFunc(func(w ResponseWriter, r *Request) {
  4292  		_, ok := w.(io.StringWriter)
  4293  		okc <- ok
  4294  	}))
  4295  	ht.rawResponse("GET / HTTP/1.0")
  4296  	select {
  4297  	case ok := <-okc:
  4298  		if !ok {
  4299  			t.Error("ResponseWriter did not implement io.StringWriter")
  4300  		}
  4301  	default:
  4302  		t.Error("handler was never called")
  4303  	}
  4304  }
  4305  
  4306  func TestServerConnState(t *testing.T) { run(t, testServerConnState, []testMode{http1Mode}) }
  4307  func testServerConnState(t *testing.T, mode testMode) {
  4308  	handler := map[string]func(w ResponseWriter, r *Request){
  4309  		"/": func(w ResponseWriter, r *Request) {
  4310  			fmt.Fprintf(w, "Hello.")
  4311  		},
  4312  		"/close": func(w ResponseWriter, r *Request) {
  4313  			w.Header().Set("Connection", "close")
  4314  			fmt.Fprintf(w, "Hello.")
  4315  		},
  4316  		"/hijack": func(w ResponseWriter, r *Request) {
  4317  			c, _, _ := w.(Hijacker).Hijack()
  4318  			c.Write([]byte("HTTP/1.0 200 OK\r\nConnection: close\r\n\r\nHello."))
  4319  			c.Close()
  4320  		},
  4321  		"/hijack-panic": func(w ResponseWriter, r *Request) {
  4322  			c, _, _ := w.(Hijacker).Hijack()
  4323  			c.Write([]byte("HTTP/1.0 200 OK\r\nConnection: close\r\n\r\nHello."))
  4324  			c.Close()
  4325  			panic("intentional panic")
  4326  		},
  4327  	}
  4328  
  4329  	// A stateLog is a log of states over the lifetime of a connection.
  4330  	type stateLog struct {
  4331  		active   net.Conn // The connection for which the log is recorded; set to the first connection seen in StateNew.
  4332  		got      []ConnState
  4333  		want     []ConnState
  4334  		complete chan<- struct{} // If non-nil, closed when either 'got' is equal to 'want', or 'got' is no longer a prefix of 'want'.
  4335  	}
  4336  	activeLog := make(chan *stateLog, 1)
  4337  
  4338  	// wantLog invokes doRequests, then waits for the resulting connection to
  4339  	// either pass through the sequence of states in want or enter a state outside
  4340  	// of that sequence.
  4341  	wantLog := func(doRequests func(), want ...ConnState) {
  4342  		t.Helper()
  4343  		complete := make(chan struct{})
  4344  		activeLog <- &stateLog{want: want, complete: complete}
  4345  
  4346  		doRequests()
  4347  
  4348  		<-complete
  4349  		sl := <-activeLog
  4350  		if !slices.Equal(sl.got, sl.want) {
  4351  			t.Errorf("Request(s) produced unexpected state sequence.\nGot:  %v\nWant: %v", sl.got, sl.want)
  4352  		}
  4353  		// Don't return sl to activeLog: we don't expect any further states after
  4354  		// this point, and want to keep the ConnState callback blocked until the
  4355  		// next call to wantLog.
  4356  	}
  4357  
  4358  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  4359  		handler[r.URL.Path](w, r)
  4360  	}), func(ts *httptest.Server) {
  4361  		ts.Config.ErrorLog = log.New(io.Discard, "", 0)
  4362  		ts.Config.ConnState = func(c net.Conn, state ConnState) {
  4363  			if c == nil {
  4364  				t.Errorf("nil conn seen in state %s", state)
  4365  				return
  4366  			}
  4367  			sl := <-activeLog
  4368  			if sl.active == nil && state == StateNew {
  4369  				sl.active = c
  4370  			} else if sl.active != c {
  4371  				t.Errorf("unexpected conn in state %s", state)
  4372  				activeLog <- sl
  4373  				return
  4374  			}
  4375  			sl.got = append(sl.got, state)
  4376  			if sl.complete != nil && (len(sl.got) >= len(sl.want) || !slices.Equal(sl.got, sl.want[:len(sl.got)])) {
  4377  				close(sl.complete)
  4378  				sl.complete = nil
  4379  			}
  4380  			activeLog <- sl
  4381  		}
  4382  	}).ts
  4383  	defer func() {
  4384  		activeLog <- &stateLog{} // If the test failed, allow any remaining ConnState callbacks to complete.
  4385  		ts.Close()
  4386  	}()
  4387  
  4388  	c := ts.Client()
  4389  
  4390  	mustGet := func(url string, headers ...string) {
  4391  		t.Helper()
  4392  		req, err := NewRequest("GET", url, nil)
  4393  		if err != nil {
  4394  			t.Fatal(err)
  4395  		}
  4396  		for len(headers) > 0 {
  4397  			req.Header.Add(headers[0], headers[1])
  4398  			headers = headers[2:]
  4399  		}
  4400  		res, err := c.Do(req)
  4401  		if err != nil {
  4402  			t.Errorf("Error fetching %s: %v", url, err)
  4403  			return
  4404  		}
  4405  		_, err = io.ReadAll(res.Body)
  4406  		defer res.Body.Close()
  4407  		if err != nil {
  4408  			t.Errorf("Error reading %s: %v", url, err)
  4409  		}
  4410  	}
  4411  
  4412  	wantLog(func() {
  4413  		mustGet(ts.URL + "/")
  4414  		mustGet(ts.URL + "/close")
  4415  	}, StateNew, StateActive, StateIdle, StateActive, StateClosed)
  4416  
  4417  	wantLog(func() {
  4418  		mustGet(ts.URL + "/")
  4419  		mustGet(ts.URL+"/", "Connection", "close")
  4420  	}, StateNew, StateActive, StateIdle, StateActive, StateClosed)
  4421  
  4422  	wantLog(func() {
  4423  		mustGet(ts.URL + "/hijack")
  4424  	}, StateNew, StateActive, StateHijacked)
  4425  
  4426  	wantLog(func() {
  4427  		mustGet(ts.URL + "/hijack-panic")
  4428  	}, StateNew, StateActive, StateHijacked)
  4429  
  4430  	wantLog(func() {
  4431  		c, err := net.Dial("tcp", ts.Listener.Addr().String())
  4432  		if err != nil {
  4433  			t.Fatal(err)
  4434  		}
  4435  		c.Close()
  4436  	}, StateNew, StateClosed)
  4437  
  4438  	wantLog(func() {
  4439  		c, err := net.Dial("tcp", ts.Listener.Addr().String())
  4440  		if err != nil {
  4441  			t.Fatal(err)
  4442  		}
  4443  		if _, err := io.WriteString(c, "BOGUS REQUEST\r\n\r\n"); err != nil {
  4444  			t.Fatal(err)
  4445  		}
  4446  		c.Read(make([]byte, 1)) // block until server hangs up on us
  4447  		c.Close()
  4448  	}, StateNew, StateActive, StateClosed)
  4449  
  4450  	wantLog(func() {
  4451  		c, err := net.Dial("tcp", ts.Listener.Addr().String())
  4452  		if err != nil {
  4453  			t.Fatal(err)
  4454  		}
  4455  		if _, err := io.WriteString(c, "GET / HTTP/1.1\r\nHost: foo\r\n\r\n"); err != nil {
  4456  			t.Fatal(err)
  4457  		}
  4458  		res, err := ReadResponse(bufio.NewReader(c), nil)
  4459  		if err != nil {
  4460  			t.Fatal(err)
  4461  		}
  4462  		if _, err := io.Copy(io.Discard, res.Body); err != nil {
  4463  			t.Fatal(err)
  4464  		}
  4465  		c.Close()
  4466  	}, StateNew, StateActive, StateIdle, StateClosed)
  4467  }
  4468  
  4469  func TestServerKeepAlivesEnabledResultClose(t *testing.T) {
  4470  	run(t, testServerKeepAlivesEnabledResultClose, []testMode{http1Mode})
  4471  }
  4472  func testServerKeepAlivesEnabledResultClose(t *testing.T, mode testMode) {
  4473  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  4474  	}), func(ts *httptest.Server) {
  4475  		ts.Config.SetKeepAlivesEnabled(false)
  4476  	}).ts
  4477  	res, err := ts.Client().Get(ts.URL)
  4478  	if err != nil {
  4479  		t.Fatal(err)
  4480  	}
  4481  	defer res.Body.Close()
  4482  	if !res.Close {
  4483  		t.Errorf("Body.Close == false; want true")
  4484  	}
  4485  }
  4486  
  4487  // golang.org/issue/7856
  4488  func TestServerEmptyBodyRace(t *testing.T) { run(t, testServerEmptyBodyRace) }
  4489  func testServerEmptyBodyRace(t *testing.T, mode testMode) {
  4490  	var n int32
  4491  	cst := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, req *Request) {
  4492  		atomic.AddInt32(&n, 1)
  4493  	}), optQuietLog)
  4494  	var wg sync.WaitGroup
  4495  	const reqs = 20
  4496  	for i := 0; i < reqs; i++ {
  4497  		wg.Add(1)
  4498  		go func() {
  4499  			defer wg.Done()
  4500  			res, err := cst.c.Get(cst.ts.URL)
  4501  			if err != nil {
  4502  				// Try to deflake spurious "connection reset by peer" under load.
  4503  				// See golang.org/issue/22540.
  4504  				time.Sleep(10 * time.Millisecond)
  4505  				res, err = cst.c.Get(cst.ts.URL)
  4506  				if err != nil {
  4507  					t.Error(err)
  4508  					return
  4509  				}
  4510  			}
  4511  			defer res.Body.Close()
  4512  			_, err = io.Copy(io.Discard, res.Body)
  4513  			if err != nil {
  4514  				t.Error(err)
  4515  				return
  4516  			}
  4517  		}()
  4518  	}
  4519  	wg.Wait()
  4520  	if got := atomic.LoadInt32(&n); got != reqs {
  4521  		t.Errorf("handler ran %d times; want %d", got, reqs)
  4522  	}
  4523  }
  4524  
  4525  func TestServerConnStateNew(t *testing.T) {
  4526  	sawNew := false // if the test is buggy, we'll race on this variable.
  4527  	srv := &Server{
  4528  		ConnState: func(c net.Conn, state ConnState) {
  4529  			if state == StateNew {
  4530  				sawNew = true // testing that this write isn't racy
  4531  			}
  4532  		},
  4533  		Handler: HandlerFunc(func(w ResponseWriter, r *Request) {}), // irrelevant
  4534  	}
  4535  	srv.Serve(&oneConnListener{
  4536  		conn: &rwTestConn{
  4537  			Reader: strings.NewReader("GET / HTTP/1.1\r\nHost: foo\r\n\r\n"),
  4538  			Writer: io.Discard,
  4539  		},
  4540  	})
  4541  	if !sawNew { // testing that this read isn't racy
  4542  		t.Error("StateNew not seen")
  4543  	}
  4544  }
  4545  
  4546  type closeWriteTestConn struct {
  4547  	rwTestConn
  4548  	didCloseWrite bool
  4549  }
  4550  
  4551  func (c *closeWriteTestConn) CloseWrite() error {
  4552  	c.didCloseWrite = true
  4553  	return nil
  4554  }
  4555  
  4556  func TestCloseWrite(t *testing.T) {
  4557  	SetRSTAvoidanceDelay(t, 1*time.Millisecond)
  4558  
  4559  	var srv Server
  4560  	var testConn closeWriteTestConn
  4561  	c := ExportServerNewConn(&srv, &testConn)
  4562  	ExportCloseWriteAndWait(c)
  4563  	if !testConn.didCloseWrite {
  4564  		t.Error("didn't see CloseWrite call")
  4565  	}
  4566  }
  4567  
  4568  // This verifies that a handler can Flush and then Hijack.
  4569  //
  4570  // A similar test crashed once during development, but it was only
  4571  // testing this tangentially and temporarily until another TODO was
  4572  // fixed.
  4573  //
  4574  // So add an explicit test for this.
  4575  func TestServerFlushAndHijack(t *testing.T) { run(t, testServerFlushAndHijack, []testMode{http1Mode}) }
  4576  func testServerFlushAndHijack(t *testing.T, mode testMode) {
  4577  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  4578  		io.WriteString(w, "Hello, ")
  4579  		w.(Flusher).Flush()
  4580  		conn, buf, _ := w.(Hijacker).Hijack()
  4581  		buf.WriteString("6\r\nworld!\r\n0\r\n\r\n")
  4582  		if err := buf.Flush(); err != nil {
  4583  			t.Error(err)
  4584  		}
  4585  		if err := conn.Close(); err != nil {
  4586  			t.Error(err)
  4587  		}
  4588  	})).ts
  4589  	res, err := Get(ts.URL)
  4590  	if err != nil {
  4591  		t.Fatal(err)
  4592  	}
  4593  	defer res.Body.Close()
  4594  	all, err := io.ReadAll(res.Body)
  4595  	if err != nil {
  4596  		t.Fatal(err)
  4597  	}
  4598  	if want := "Hello, world!"; string(all) != want {
  4599  		t.Errorf("Got %q; want %q", all, want)
  4600  	}
  4601  }
  4602  
  4603  // golang.org/issue/8534 -- the Server shouldn't reuse a connection
  4604  // for keep-alive after it's seen any Write error (e.g. a timeout) on
  4605  // that net.Conn.
  4606  //
  4607  // To test, verify we don't timeout or see fewer unique client
  4608  // addresses (== unique connections) than requests.
  4609  func TestServerKeepAliveAfterWriteError(t *testing.T) {
  4610  	run(t, testServerKeepAliveAfterWriteError, []testMode{http1Mode})
  4611  }
  4612  func testServerKeepAliveAfterWriteError(t *testing.T, mode testMode) {
  4613  	if testing.Short() {
  4614  		t.Skip("skipping in -short mode")
  4615  	}
  4616  	const numReq = 3
  4617  	addrc := make(chan string, numReq)
  4618  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  4619  		addrc <- r.RemoteAddr
  4620  		time.Sleep(500 * time.Millisecond)
  4621  		w.(Flusher).Flush()
  4622  	}), func(ts *httptest.Server) {
  4623  		ts.Config.WriteTimeout = 250 * time.Millisecond
  4624  	}).ts
  4625  
  4626  	errc := make(chan error, numReq)
  4627  	go func() {
  4628  		defer close(errc)
  4629  		for i := 0; i < numReq; i++ {
  4630  			res, err := Get(ts.URL)
  4631  			if res != nil {
  4632  				res.Body.Close()
  4633  			}
  4634  			errc <- err
  4635  		}
  4636  	}()
  4637  
  4638  	addrSeen := map[string]bool{}
  4639  	numOkay := 0
  4640  	for {
  4641  		select {
  4642  		case v := <-addrc:
  4643  			addrSeen[v] = true
  4644  		case err, ok := <-errc:
  4645  			if !ok {
  4646  				if len(addrSeen) != numReq {
  4647  					t.Errorf("saw %d unique client addresses; want %d", len(addrSeen), numReq)
  4648  				}
  4649  				if numOkay != 0 {
  4650  					t.Errorf("got %d successful client requests; want 0", numOkay)
  4651  				}
  4652  				return
  4653  			}
  4654  			if err == nil {
  4655  				numOkay++
  4656  			}
  4657  		}
  4658  	}
  4659  }
  4660  
  4661  // Issue 9987: shouldn't add automatic Content-Length (or
  4662  // Content-Type) if a Transfer-Encoding was set by the handler.
  4663  func TestNoContentLengthIfTransferEncoding(t *testing.T) {
  4664  	run(t, testNoContentLengthIfTransferEncoding, []testMode{http1Mode})
  4665  }
  4666  func testNoContentLengthIfTransferEncoding(t *testing.T, mode testMode) {
  4667  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  4668  		w.Header().Set("Transfer-Encoding", "foo")
  4669  		io.WriteString(w, "<html>")
  4670  	})).ts
  4671  	c, err := net.Dial("tcp", ts.Listener.Addr().String())
  4672  	if err != nil {
  4673  		t.Fatalf("Dial: %v", err)
  4674  	}
  4675  	defer c.Close()
  4676  	if _, err := io.WriteString(c, "GET / HTTP/1.1\r\nHost: foo\r\n\r\n"); err != nil {
  4677  		t.Fatal(err)
  4678  	}
  4679  	bs := bufio.NewScanner(c)
  4680  	var got strings.Builder
  4681  	for bs.Scan() {
  4682  		if strings.TrimSpace(bs.Text()) == "" {
  4683  			break
  4684  		}
  4685  		got.WriteString(bs.Text())
  4686  		got.WriteByte('\n')
  4687  	}
  4688  	if err := bs.Err(); err != nil {
  4689  		t.Fatal(err)
  4690  	}
  4691  	if strings.Contains(got.String(), "Content-Length") {
  4692  		t.Errorf("Unexpected Content-Length in response headers: %s", got.String())
  4693  	}
  4694  	if strings.Contains(got.String(), "Content-Type") {
  4695  		t.Errorf("Unexpected Content-Type in response headers: %s", got.String())
  4696  	}
  4697  }
  4698  
  4699  // tolerate extra CRLF(s) before Request-Line on subsequent requests on a conn
  4700  // Issue 10876.
  4701  func TestTolerateCRLFBeforeRequestLine(t *testing.T) {
  4702  	req := []byte("POST / HTTP/1.1\r\nHost: golang.org\r\nContent-Length: 3\r\n\r\nABC" +
  4703  		"\r\n\r\n" + // <-- this stuff is bogus, but we'll ignore it
  4704  		"GET / HTTP/1.1\r\nHost: golang.org\r\n\r\n")
  4705  	var buf bytes.Buffer
  4706  	conn := &rwTestConn{
  4707  		Reader: bytes.NewReader(req),
  4708  		Writer: &buf,
  4709  		closec: make(chan bool, 1),
  4710  	}
  4711  	ln := &oneConnListener{conn: conn}
  4712  	numReq := 0
  4713  	go Serve(ln, HandlerFunc(func(rw ResponseWriter, r *Request) {
  4714  		numReq++
  4715  	}))
  4716  	<-conn.closec
  4717  	if numReq != 2 {
  4718  		t.Errorf("num requests = %d; want 2", numReq)
  4719  		t.Logf("Res: %s", buf.Bytes())
  4720  	}
  4721  }
  4722  
  4723  func TestIssue13893_Expect100(t *testing.T) {
  4724  	// test that the Server doesn't filter out Expect headers.
  4725  	req := reqBytes(`PUT /readbody HTTP/1.1
  4726  User-Agent: PycURL/7.22.0
  4727  Host: 127.0.0.1:9000
  4728  Accept: */*
  4729  Expect: 100-continue
  4730  Content-Length: 10
  4731  
  4732  HelloWorld
  4733  
  4734  `)
  4735  	var buf bytes.Buffer
  4736  	conn := &rwTestConn{
  4737  		Reader: bytes.NewReader(req),
  4738  		Writer: &buf,
  4739  		closec: make(chan bool, 1),
  4740  	}
  4741  	ln := &oneConnListener{conn: conn}
  4742  	go Serve(ln, HandlerFunc(func(w ResponseWriter, r *Request) {
  4743  		if _, ok := r.Header["Expect"]; !ok {
  4744  			t.Error("Expect header should not be filtered out")
  4745  		}
  4746  	}))
  4747  	<-conn.closec
  4748  }
  4749  
  4750  func TestIssue11549_Expect100(t *testing.T) {
  4751  	req := reqBytes(`PUT /readbody HTTP/1.1
  4752  User-Agent: PycURL/7.22.0
  4753  Host: 127.0.0.1:9000
  4754  Accept: */*
  4755  Expect: 100-continue
  4756  Content-Length: 10
  4757  
  4758  HelloWorldPUT /noreadbody HTTP/1.1
  4759  User-Agent: PycURL/7.22.0
  4760  Host: 127.0.0.1:9000
  4761  Accept: */*
  4762  Expect: 100-continue
  4763  Content-Length: 10
  4764  
  4765  GET /should-be-ignored HTTP/1.1
  4766  Host: foo
  4767  
  4768  `)
  4769  	var buf strings.Builder
  4770  	conn := &rwTestConn{
  4771  		Reader: bytes.NewReader(req),
  4772  		Writer: &buf,
  4773  		closec: make(chan bool, 1),
  4774  	}
  4775  	ln := &oneConnListener{conn: conn}
  4776  	numReq := 0
  4777  	go Serve(ln, HandlerFunc(func(w ResponseWriter, r *Request) {
  4778  		numReq++
  4779  		if r.URL.Path == "/readbody" {
  4780  			io.ReadAll(r.Body)
  4781  		}
  4782  		io.WriteString(w, "Hello world!")
  4783  	}))
  4784  	<-conn.closec
  4785  	if numReq != 2 {
  4786  		t.Errorf("num requests = %d; want 2", numReq)
  4787  	}
  4788  	if !strings.Contains(buf.String(), "Connection: close\r\n") {
  4789  		t.Errorf("expected 'Connection: close' in response; got: %s", buf.String())
  4790  	}
  4791  }
  4792  
  4793  // If a Handler finishes and there's an unread request body,
  4794  // verify the server implicitly tries to do a read on it before replying.
  4795  func TestHandlerFinishSkipBigContentLengthRead(t *testing.T) {
  4796  	setParallel(t)
  4797  	conn := newTestConn()
  4798  	conn.readBuf.WriteString(
  4799  		"POST / HTTP/1.1\r\n" +
  4800  			"Host: test\r\n" +
  4801  			"Content-Length: 9999999999\r\n" +
  4802  			"\r\n" + strings.Repeat("a", 1<<20))
  4803  
  4804  	ls := &oneConnListener{conn}
  4805  	var inHandlerLen int
  4806  	go Serve(ls, HandlerFunc(func(rw ResponseWriter, req *Request) {
  4807  		inHandlerLen = conn.readBuf.Len()
  4808  		rw.WriteHeader(404)
  4809  	}))
  4810  	<-conn.closec
  4811  	afterHandlerLen := conn.readBuf.Len()
  4812  
  4813  	if afterHandlerLen != inHandlerLen {
  4814  		t.Errorf("unexpected implicit read. Read buffer went from %d -> %d", inHandlerLen, afterHandlerLen)
  4815  	}
  4816  }
  4817  
  4818  func TestHandlerSetsBodyNil(t *testing.T) { run(t, testHandlerSetsBodyNil) }
  4819  func testHandlerSetsBodyNil(t *testing.T, mode testMode) {
  4820  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  4821  		r.Body = nil
  4822  		fmt.Fprintf(w, "%v", r.RemoteAddr)
  4823  	}))
  4824  	get := func() string {
  4825  		res, err := cst.c.Get(cst.ts.URL)
  4826  		if err != nil {
  4827  			t.Fatal(err)
  4828  		}
  4829  		defer res.Body.Close()
  4830  		slurp, err := io.ReadAll(res.Body)
  4831  		if err != nil {
  4832  			t.Fatal(err)
  4833  		}
  4834  		return string(slurp)
  4835  	}
  4836  	a, b := get(), get()
  4837  	if a != b {
  4838  		t.Errorf("Failed to reuse connections between requests: %v vs %v", a, b)
  4839  	}
  4840  }
  4841  
  4842  // Test that we validate the Host header.
  4843  // Issue 11206 (invalid bytes in Host) and 13624 (Host present in HTTP/1.1)
  4844  func TestServerValidatesHostHeader(t *testing.T) {
  4845  	tests := []struct {
  4846  		proto string
  4847  		host  string
  4848  		want  int
  4849  	}{
  4850  		{"HTTP/0.9", "", 505},
  4851  
  4852  		{"HTTP/1.1", "", 400},
  4853  		{"HTTP/1.1", "Host: \r\n", 200},
  4854  		{"HTTP/1.1", "Host: 1.2.3.4\r\n", 200},
  4855  		{"HTTP/1.1", "Host: foo.com\r\n", 200},
  4856  		{"HTTP/1.1", "Host: foo-bar_baz.com\r\n", 200},
  4857  		{"HTTP/1.1", "Host: foo.com:80\r\n", 200},
  4858  		{"HTTP/1.1", "Host: ::1\r\n", 200},
  4859  		{"HTTP/1.1", "Host: [::1]\r\n", 200}, // questionable without port, but accept it
  4860  		{"HTTP/1.1", "Host: [::1]:80\r\n", 200},
  4861  		{"HTTP/1.1", "Host: [::1%25en0]:80\r\n", 200},
  4862  		{"HTTP/1.1", "Host: 1.2.3.4\r\n", 200},
  4863  		{"HTTP/1.1", "Host: \x06\r\n", 400},
  4864  		{"HTTP/1.1", "Host: \xff\r\n", 400},
  4865  		{"HTTP/1.1", "Host: {\r\n", 400},
  4866  		{"HTTP/1.1", "Host: }\r\n", 400},
  4867  		{"HTTP/1.1", "Host: first\r\nHost: second\r\n", 400},
  4868  
  4869  		// HTTP/1.0 can lack a host header, but if present
  4870  		// must play by the rules too:
  4871  		{"HTTP/1.0", "", 200},
  4872  		{"HTTP/1.0", "Host: first\r\nHost: second\r\n", 400},
  4873  		{"HTTP/1.0", "Host: \xff\r\n", 400},
  4874  
  4875  		// Make an exception for HTTP upgrade requests:
  4876  		{"PRI * HTTP/2.0", "", 200},
  4877  
  4878  		// Also an exception for CONNECT requests: (Issue 18215)
  4879  		{"CONNECT golang.org:443 HTTP/1.1", "", 200},
  4880  
  4881  		// But not other HTTP/2 stuff:
  4882  		{"PRI / HTTP/2.0", "", 505},
  4883  		{"GET / HTTP/2.0", "", 505},
  4884  		{"GET / HTTP/3.0", "", 505},
  4885  	}
  4886  	for _, tt := range tests {
  4887  		conn := newTestConn()
  4888  		methodTarget := "GET / "
  4889  		if !strings.HasPrefix(tt.proto, "HTTP/") {
  4890  			methodTarget = ""
  4891  		}
  4892  		io.WriteString(&conn.readBuf, methodTarget+tt.proto+"\r\n"+tt.host+"\r\n")
  4893  
  4894  		ln := &oneConnListener{conn}
  4895  		srv := Server{
  4896  			ErrorLog: quietLog,
  4897  			Handler:  HandlerFunc(func(ResponseWriter, *Request) {}),
  4898  		}
  4899  		go srv.Serve(ln)
  4900  		<-conn.closec
  4901  		res, err := ReadResponse(bufio.NewReader(&conn.writeBuf), nil)
  4902  		if err != nil {
  4903  			t.Errorf("For %s %q, ReadResponse: %v", tt.proto, tt.host, res)
  4904  			continue
  4905  		}
  4906  		if res.StatusCode != tt.want {
  4907  			t.Errorf("For %s %q, Status = %d; want %d", tt.proto, tt.host, res.StatusCode, tt.want)
  4908  		}
  4909  	}
  4910  }
  4911  
  4912  func TestServerHandlersCanHandleH2PRI(t *testing.T) {
  4913  	run(t, testServerHandlersCanHandleH2PRI, []testMode{http1Mode})
  4914  }
  4915  func testServerHandlersCanHandleH2PRI(t *testing.T, mode testMode) {
  4916  	const upgradeResponse = "upgrade here"
  4917  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  4918  		conn, br, err := w.(Hijacker).Hijack()
  4919  		if err != nil {
  4920  			t.Error(err)
  4921  			return
  4922  		}
  4923  		defer conn.Close()
  4924  		if r.Method != "PRI" || r.RequestURI != "*" {
  4925  			t.Errorf("Got method/target %q %q; want PRI *", r.Method, r.RequestURI)
  4926  			return
  4927  		}
  4928  		if !r.Close {
  4929  			t.Errorf("Request.Close = true; want false")
  4930  		}
  4931  		const want = "SM\r\n\r\n"
  4932  		buf := make([]byte, len(want))
  4933  		n, err := io.ReadFull(br, buf)
  4934  		if err != nil || string(buf[:n]) != want {
  4935  			t.Errorf("Read = %v, %v (%q), want %q", n, err, buf[:n], want)
  4936  			return
  4937  		}
  4938  		io.WriteString(conn, upgradeResponse)
  4939  	})).ts
  4940  
  4941  	c, err := net.Dial("tcp", ts.Listener.Addr().String())
  4942  	if err != nil {
  4943  		t.Fatalf("Dial: %v", err)
  4944  	}
  4945  	defer c.Close()
  4946  	io.WriteString(c, "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n")
  4947  	slurp, err := io.ReadAll(c)
  4948  	if err != nil {
  4949  		t.Fatal(err)
  4950  	}
  4951  	if string(slurp) != upgradeResponse {
  4952  		t.Errorf("Handler response = %q; want %q", slurp, upgradeResponse)
  4953  	}
  4954  }
  4955  
  4956  // Test that we validate the valid bytes in HTTP/1 headers.
  4957  // Issue 11207.
  4958  func TestServerValidatesHeaders(t *testing.T) {
  4959  	setParallel(t)
  4960  	tests := []struct {
  4961  		header string
  4962  		want   int
  4963  	}{
  4964  		{"", 200},
  4965  		{"Foo: bar\r\n", 200},
  4966  		{"X-Foo: bar\r\n", 200},
  4967  		{"Foo: a space\r\n", 200},
  4968  
  4969  		{"A space: foo\r\n", 400},                            // space in header
  4970  		{"foo\xffbar: foo\r\n", 400},                         // binary in header
  4971  		{"foo\x00bar: foo\r\n", 400},                         // binary in header
  4972  		{"Foo: " + strings.Repeat("x", 1<<21) + "\r\n", 431}, // header too large
  4973  		// Spaces between the header key and colon are not allowed.
  4974  		// See RFC 7230, Section 3.2.4.
  4975  		{"Foo : bar\r\n", 400},
  4976  		{"Foo\t: bar\r\n", 400},
  4977  
  4978  		// Empty header keys are invalid.
  4979  		// See RFC 7230, Section 3.2.
  4980  		{": empty key\r\n", 400},
  4981  
  4982  		// Requests with invalid Content-Length headers should be rejected
  4983  		// regardless of the presence of a Transfer-Encoding header.
  4984  		// Check out RFC 9110, Section 8.6 and RFC 9112, Section 6.3.3.
  4985  		{"Content-Length: notdigits\r\n", 400},
  4986  		{"Content-Length: notdigits\r\nTransfer-Encoding: chunked\r\n\r\n0\r\n\r\n", 400},
  4987  
  4988  		{"foo: foo foo\r\n", 200},    // LWS space is okay
  4989  		{"foo: foo\tfoo\r\n", 200},   // LWS tab is okay
  4990  		{"foo: foo\x00foo\r\n", 400}, // CTL 0x00 in value is bad
  4991  		{"foo: foo\x7ffoo\r\n", 400}, // CTL 0x7f in value is bad
  4992  		{"foo: foo\xfffoo\r\n", 200}, // non-ASCII high octets in value are fine
  4993  	}
  4994  	for _, tt := range tests {
  4995  		conn := newTestConn()
  4996  		io.WriteString(&conn.readBuf, "GET / HTTP/1.1\r\nHost: foo\r\n"+tt.header+"\r\n")
  4997  
  4998  		ln := &oneConnListener{conn}
  4999  		srv := Server{
  5000  			ErrorLog: quietLog,
  5001  			Handler:  HandlerFunc(func(ResponseWriter, *Request) {}),
  5002  		}
  5003  		go srv.Serve(ln)
  5004  		<-conn.closec
  5005  		res, err := ReadResponse(bufio.NewReader(&conn.writeBuf), nil)
  5006  		if err != nil {
  5007  			t.Errorf("For %q, ReadResponse: %v", tt.header, res)
  5008  			continue
  5009  		}
  5010  		if res.StatusCode != tt.want {
  5011  			t.Errorf("For %q, Status = %d; want %d", tt.header, res.StatusCode, tt.want)
  5012  		}
  5013  	}
  5014  }
  5015  
  5016  func TestServerRequestContextCancel_ServeHTTPDone(t *testing.T) {
  5017  	run(t, testServerRequestContextCancel_ServeHTTPDone)
  5018  }
  5019  func testServerRequestContextCancel_ServeHTTPDone(t *testing.T, mode testMode) {
  5020  	ctxc := make(chan context.Context, 1)
  5021  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  5022  		ctx := r.Context()
  5023  		select {
  5024  		case <-ctx.Done():
  5025  			t.Error("should not be Done in ServeHTTP")
  5026  		default:
  5027  		}
  5028  		ctxc <- ctx
  5029  	}))
  5030  	res, err := cst.c.Get(cst.ts.URL)
  5031  	if err != nil {
  5032  		t.Fatal(err)
  5033  	}
  5034  	res.Body.Close()
  5035  	ctx := <-ctxc
  5036  	select {
  5037  	case <-ctx.Done():
  5038  	default:
  5039  		t.Error("context should be done after ServeHTTP completes")
  5040  	}
  5041  }
  5042  
  5043  // Tests that the Request.Context available to the Handler is canceled
  5044  // if the peer closes their TCP connection. This requires that the server
  5045  // is always blocked in a Read call so it notices the EOF from the client.
  5046  // See issues 15927 and 15224.
  5047  func TestServerRequestContextCancel_ConnClose(t *testing.T) {
  5048  	run(t, testServerRequestContextCancel_ConnClose, []testMode{http1Mode})
  5049  }
  5050  func testServerRequestContextCancel_ConnClose(t *testing.T, mode testMode) {
  5051  	inHandler := make(chan struct{})
  5052  	handlerDone := make(chan struct{})
  5053  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  5054  		close(inHandler)
  5055  		<-r.Context().Done()
  5056  		close(handlerDone)
  5057  	})).ts
  5058  	c, err := net.Dial("tcp", ts.Listener.Addr().String())
  5059  	if err != nil {
  5060  		t.Fatal(err)
  5061  	}
  5062  	defer c.Close()
  5063  	io.WriteString(c, "GET / HTTP/1.1\r\nHost: foo\r\n\r\n")
  5064  	<-inHandler
  5065  	c.Close() // this should trigger the context being done
  5066  	<-handlerDone
  5067  }
  5068  
  5069  func TestServerContext_ServerContextKey(t *testing.T) {
  5070  	run(t, testServerContext_ServerContextKey)
  5071  }
  5072  func testServerContext_ServerContextKey(t *testing.T, mode testMode) {
  5073  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  5074  		ctx := r.Context()
  5075  		got := ctx.Value(ServerContextKey)
  5076  		if _, ok := got.(*Server); !ok {
  5077  			t.Errorf("context value = %T; want *http.Server", got)
  5078  		}
  5079  	}))
  5080  	res, err := cst.c.Get(cst.ts.URL)
  5081  	if err != nil {
  5082  		t.Fatal(err)
  5083  	}
  5084  	res.Body.Close()
  5085  }
  5086  
  5087  func TestServerContext_LocalAddrContextKey(t *testing.T) {
  5088  	run(t, testServerContext_LocalAddrContextKey)
  5089  }
  5090  func testServerContext_LocalAddrContextKey(t *testing.T, mode testMode) {
  5091  	ch := make(chan any, 1)
  5092  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  5093  		ch <- r.Context().Value(LocalAddrContextKey)
  5094  	}))
  5095  	if _, err := cst.c.Head(cst.ts.URL); err != nil {
  5096  		t.Fatal(err)
  5097  	}
  5098  
  5099  	host := cst.ts.Listener.Addr().String()
  5100  	got := <-ch
  5101  	if addr, ok := got.(net.Addr); !ok {
  5102  		t.Errorf("local addr value = %T; want net.Addr", got)
  5103  	} else if fmt.Sprint(addr) != host {
  5104  		t.Errorf("local addr = %v; want %v", addr, host)
  5105  	}
  5106  }
  5107  
  5108  // https://golang.org/issue/15960
  5109  func TestHandlerSetTransferEncodingChunked(t *testing.T) {
  5110  	setParallel(t)
  5111  	defer afterTest(t)
  5112  	ht := newHandlerTest(HandlerFunc(func(w ResponseWriter, r *Request) {
  5113  		w.Header().Set("Transfer-Encoding", "chunked")
  5114  		w.Write([]byte("hello"))
  5115  	}))
  5116  	resp := ht.rawResponse("GET / HTTP/1.1\nHost: foo")
  5117  	const hdr = "Transfer-Encoding: chunked"
  5118  	if n := strings.Count(resp, hdr); n != 1 {
  5119  		t.Errorf("want 1 occurrence of %q in response, got %v\nresponse: %v", hdr, n, resp)
  5120  	}
  5121  }
  5122  
  5123  // https://golang.org/issue/16063
  5124  func TestHandlerSetTransferEncodingGzip(t *testing.T) {
  5125  	setParallel(t)
  5126  	defer afterTest(t)
  5127  	ht := newHandlerTest(HandlerFunc(func(w ResponseWriter, r *Request) {
  5128  		w.Header().Set("Transfer-Encoding", "gzip")
  5129  		gz := gzip.NewWriter(w)
  5130  		gz.Write([]byte("hello"))
  5131  		gz.Close()
  5132  	}))
  5133  	resp := ht.rawResponse("GET / HTTP/1.1\nHost: foo")
  5134  	for _, v := range []string{"gzip", "chunked"} {
  5135  		hdr := "Transfer-Encoding: " + v
  5136  		if n := strings.Count(resp, hdr); n != 1 {
  5137  			t.Errorf("want 1 occurrence of %q in response, got %v\nresponse: %v", hdr, n, resp)
  5138  		}
  5139  	}
  5140  }
  5141  
  5142  func BenchmarkClientServer(b *testing.B) {
  5143  	run(b, benchmarkClientServer, []testMode{http1Mode, https1Mode, http2Mode})
  5144  }
  5145  func benchmarkClientServer(b *testing.B, mode testMode) {
  5146  	b.ReportAllocs()
  5147  	b.StopTimer()
  5148  	ts := newClientServerTest(b, mode, HandlerFunc(func(rw ResponseWriter, r *Request) {
  5149  		fmt.Fprintf(rw, "Hello world.\n")
  5150  	})).ts
  5151  	b.StartTimer()
  5152  
  5153  	c := ts.Client()
  5154  	for i := 0; i < b.N; i++ {
  5155  		res, err := c.Get(ts.URL)
  5156  		if err != nil {
  5157  			b.Fatal("Get:", err)
  5158  		}
  5159  		all, err := io.ReadAll(res.Body)
  5160  		res.Body.Close()
  5161  		if err != nil {
  5162  			b.Fatal("ReadAll:", err)
  5163  		}
  5164  		body := string(all)
  5165  		if body != "Hello world.\n" {
  5166  			b.Fatal("Got body:", body)
  5167  		}
  5168  	}
  5169  
  5170  	b.StopTimer()
  5171  }
  5172  
  5173  func BenchmarkClientServerParallel(b *testing.B) {
  5174  	for _, parallelism := range []int{4, 64} {
  5175  		b.Run(fmt.Sprint(parallelism), func(b *testing.B) {
  5176  			run(b, func(b *testing.B, mode testMode) {
  5177  				benchmarkClientServerParallel(b, parallelism, mode)
  5178  			}, []testMode{http1Mode, https1Mode, http2Mode})
  5179  		})
  5180  	}
  5181  }
  5182  
  5183  func benchmarkClientServerParallel(b *testing.B, parallelism int, mode testMode) {
  5184  	b.ReportAllocs()
  5185  	ts := newClientServerTest(b, mode, HandlerFunc(func(rw ResponseWriter, r *Request) {
  5186  		fmt.Fprintf(rw, "Hello world.\n")
  5187  	})).ts
  5188  	b.ResetTimer()
  5189  	b.SetParallelism(parallelism)
  5190  	b.RunParallel(func(pb *testing.PB) {
  5191  		c := ts.Client()
  5192  		for pb.Next() {
  5193  			res, err := c.Get(ts.URL)
  5194  			if err != nil {
  5195  				b.Logf("Get: %v", err)
  5196  				continue
  5197  			}
  5198  			all, err := io.ReadAll(res.Body)
  5199  			res.Body.Close()
  5200  			if err != nil {
  5201  				b.Logf("ReadAll: %v", err)
  5202  				continue
  5203  			}
  5204  			body := string(all)
  5205  			if body != "Hello world.\n" {
  5206  				panic("Got body: " + body)
  5207  			}
  5208  		}
  5209  	})
  5210  }
  5211  
  5212  // A benchmark for profiling the server without the HTTP client code.
  5213  // The client code runs in a subprocess.
  5214  //
  5215  // For use like:
  5216  //
  5217  //	$ go test -c
  5218  //	$ ./http.test -test.run='^$' -test.bench='^BenchmarkServer$' -test.benchtime=15s -test.cpuprofile=http.prof
  5219  //	$ go tool pprof http.test http.prof
  5220  //	(pprof) web
  5221  func BenchmarkServer(b *testing.B) {
  5222  	b.ReportAllocs()
  5223  	// Child process mode;
  5224  	if url := os.Getenv("TEST_BENCH_SERVER_URL"); url != "" {
  5225  		n, err := strconv.Atoi(os.Getenv("TEST_BENCH_CLIENT_N"))
  5226  		if err != nil {
  5227  			panic(err)
  5228  		}
  5229  		for i := 0; i < n; i++ {
  5230  			res, err := Get(url)
  5231  			if err != nil {
  5232  				log.Panicf("Get: %v", err)
  5233  			}
  5234  			all, err := io.ReadAll(res.Body)
  5235  			res.Body.Close()
  5236  			if err != nil {
  5237  				log.Panicf("ReadAll: %v", err)
  5238  			}
  5239  			body := string(all)
  5240  			if body != "Hello world.\n" {
  5241  				log.Panicf("Got body: %q", body)
  5242  			}
  5243  		}
  5244  		os.Exit(0)
  5245  		return
  5246  	}
  5247  
  5248  	var res = []byte("Hello world.\n")
  5249  	b.StopTimer()
  5250  	ts := httptest.NewServer(HandlerFunc(func(rw ResponseWriter, r *Request) {
  5251  		rw.Header().Set("Content-Type", "text/html; charset=utf-8")
  5252  		rw.Write(res)
  5253  	}))
  5254  	defer ts.Close()
  5255  	b.StartTimer()
  5256  
  5257  	cmd := testenv.Command(b, os.Args[0], "-test.run=^$", "-test.bench=^BenchmarkServer$")
  5258  	cmd.Env = append([]string{
  5259  		fmt.Sprintf("TEST_BENCH_CLIENT_N=%d", b.N),
  5260  		fmt.Sprintf("TEST_BENCH_SERVER_URL=%s", ts.URL),
  5261  	}, os.Environ()...)
  5262  	out, err := cmd.CombinedOutput()
  5263  	if err != nil {
  5264  		b.Errorf("Test failure: %v, with output: %s", err, out)
  5265  	}
  5266  }
  5267  
  5268  // getNoBody wraps Get but closes any Response.Body before returning the response.
  5269  func getNoBody(urlStr string) (*Response, error) {
  5270  	res, err := Get(urlStr)
  5271  	if err != nil {
  5272  		return nil, err
  5273  	}
  5274  	res.Body.Close()
  5275  	return res, nil
  5276  }
  5277  
  5278  // A benchmark for profiling the client without the HTTP server code.
  5279  // The server code runs in a subprocess.
  5280  func BenchmarkClient(b *testing.B) {
  5281  	b.ReportAllocs()
  5282  	b.StopTimer()
  5283  	defer afterTest(b)
  5284  
  5285  	var data = []byte("Hello world.\n")
  5286  	if server := os.Getenv("TEST_BENCH_SERVER"); server != "" {
  5287  		// Server process mode.
  5288  		port := os.Getenv("TEST_BENCH_SERVER_PORT") // can be set by user
  5289  		if port == "" {
  5290  			port = "0"
  5291  		}
  5292  		ln, err := net.Listen("tcp", "localhost:"+port)
  5293  		if err != nil {
  5294  			fmt.Fprintln(os.Stderr, err.Error())
  5295  			os.Exit(1)
  5296  		}
  5297  		fmt.Println(ln.Addr().String())
  5298  		HandleFunc("/", func(w ResponseWriter, r *Request) {
  5299  			r.ParseForm()
  5300  			if r.Form.Get("stop") != "" {
  5301  				os.Exit(0)
  5302  			}
  5303  			w.Header().Set("Content-Type", "text/html; charset=utf-8")
  5304  			w.Write(data)
  5305  		})
  5306  		var srv Server
  5307  		log.Fatal(srv.Serve(ln))
  5308  	}
  5309  
  5310  	// Start server process.
  5311  	ctx, cancel := context.WithCancel(context.Background())
  5312  	cmd := testenv.CommandContext(b, ctx, os.Args[0], "-test.run=^$", "-test.bench=^BenchmarkClient$")
  5313  	cmd.Env = append(cmd.Environ(), "TEST_BENCH_SERVER=yes")
  5314  	cmd.Stderr = os.Stderr
  5315  	stdout, err := cmd.StdoutPipe()
  5316  	if err != nil {
  5317  		b.Fatal(err)
  5318  	}
  5319  	if err := cmd.Start(); err != nil {
  5320  		b.Fatalf("subprocess failed to start: %v", err)
  5321  	}
  5322  
  5323  	done := make(chan error, 1)
  5324  	go func() {
  5325  		done <- cmd.Wait()
  5326  		close(done)
  5327  	}()
  5328  	defer func() {
  5329  		cancel()
  5330  		<-done
  5331  	}()
  5332  
  5333  	// Wait for the server in the child process to respond and tell us
  5334  	// its listening address, once it's started listening:
  5335  	bs := bufio.NewScanner(stdout)
  5336  	if !bs.Scan() {
  5337  		b.Fatalf("failed to read listening URL from child: %v", bs.Err())
  5338  	}
  5339  	url := "http://" + strings.TrimSpace(bs.Text()) + "/"
  5340  	if _, err := getNoBody(url); err != nil {
  5341  		b.Fatalf("initial probe of child process failed: %v", err)
  5342  	}
  5343  
  5344  	// Do b.N requests to the server.
  5345  	b.StartTimer()
  5346  	for i := 0; i < b.N; i++ {
  5347  		res, err := Get(url)
  5348  		if err != nil {
  5349  			b.Fatalf("Get: %v", err)
  5350  		}
  5351  		body, err := io.ReadAll(res.Body)
  5352  		res.Body.Close()
  5353  		if err != nil {
  5354  			b.Fatalf("ReadAll: %v", err)
  5355  		}
  5356  		if !bytes.Equal(body, data) {
  5357  			b.Fatalf("Got body: %q", body)
  5358  		}
  5359  	}
  5360  	b.StopTimer()
  5361  
  5362  	// Instruct server process to stop.
  5363  	getNoBody(url + "?stop=yes")
  5364  	if err := <-done; err != nil {
  5365  		b.Fatalf("subprocess failed: %v", err)
  5366  	}
  5367  }
  5368  
  5369  func BenchmarkServerFakeConnNoKeepAlive(b *testing.B) {
  5370  	b.ReportAllocs()
  5371  	req := reqBytes(`GET / HTTP/1.0
  5372  Host: golang.org
  5373  Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
  5374  User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.17 (KHTML, like Gecko) Chrome/24.0.1312.52 Safari/537.17
  5375  Accept-Encoding: gzip,deflate,sdch
  5376  Accept-Language: en-US,en;q=0.8
  5377  Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3
  5378  `)
  5379  	res := []byte("Hello world!\n")
  5380  
  5381  	conn := newTestConn()
  5382  	handler := HandlerFunc(func(rw ResponseWriter, r *Request) {
  5383  		rw.Header().Set("Content-Type", "text/html; charset=utf-8")
  5384  		rw.Write(res)
  5385  	})
  5386  	ln := new(oneConnListener)
  5387  	for i := 0; i < b.N; i++ {
  5388  		conn.readBuf.Reset()
  5389  		conn.writeBuf.Reset()
  5390  		conn.readBuf.Write(req)
  5391  		ln.conn = conn
  5392  		Serve(ln, handler)
  5393  		<-conn.closec
  5394  	}
  5395  }
  5396  
  5397  // repeatReader reads content count times, then EOFs.
  5398  type repeatReader struct {
  5399  	content []byte
  5400  	count   int
  5401  	off     int
  5402  }
  5403  
  5404  func (r *repeatReader) Read(p []byte) (n int, err error) {
  5405  	if r.count <= 0 {
  5406  		return 0, io.EOF
  5407  	}
  5408  	n = copy(p, r.content[r.off:])
  5409  	r.off += n
  5410  	if r.off == len(r.content) {
  5411  		r.count--
  5412  		r.off = 0
  5413  	}
  5414  	return
  5415  }
  5416  
  5417  func BenchmarkServerFakeConnWithKeepAlive(b *testing.B) {
  5418  	b.ReportAllocs()
  5419  
  5420  	req := reqBytes(`GET / HTTP/1.1
  5421  Host: golang.org
  5422  Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
  5423  User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.17 (KHTML, like Gecko) Chrome/24.0.1312.52 Safari/537.17
  5424  Accept-Encoding: gzip,deflate,sdch
  5425  Accept-Language: en-US,en;q=0.8
  5426  Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3
  5427  `)
  5428  	res := []byte("Hello world!\n")
  5429  
  5430  	conn := &rwTestConn{
  5431  		Reader: &repeatReader{content: req, count: b.N},
  5432  		Writer: io.Discard,
  5433  		closec: make(chan bool, 1),
  5434  	}
  5435  	handled := 0
  5436  	handler := HandlerFunc(func(rw ResponseWriter, r *Request) {
  5437  		handled++
  5438  		rw.Header().Set("Content-Type", "text/html; charset=utf-8")
  5439  		rw.Write(res)
  5440  	})
  5441  	ln := &oneConnListener{conn: conn}
  5442  	go Serve(ln, handler)
  5443  	<-conn.closec
  5444  	if b.N != handled {
  5445  		b.Errorf("b.N=%d but handled %d", b.N, handled)
  5446  	}
  5447  }
  5448  
  5449  // same as above, but representing the most simple possible request
  5450  // and handler. Notably: the handler does not call rw.Header().
  5451  func BenchmarkServerFakeConnWithKeepAliveLite(b *testing.B) {
  5452  	b.ReportAllocs()
  5453  
  5454  	req := reqBytes(`GET / HTTP/1.1
  5455  Host: golang.org
  5456  `)
  5457  	res := []byte("Hello world!\n")
  5458  
  5459  	conn := &rwTestConn{
  5460  		Reader: &repeatReader{content: req, count: b.N},
  5461  		Writer: io.Discard,
  5462  		closec: make(chan bool, 1),
  5463  	}
  5464  	handled := 0
  5465  	handler := HandlerFunc(func(rw ResponseWriter, r *Request) {
  5466  		handled++
  5467  		rw.Write(res)
  5468  	})
  5469  	ln := &oneConnListener{conn: conn}
  5470  	go Serve(ln, handler)
  5471  	<-conn.closec
  5472  	if b.N != handled {
  5473  		b.Errorf("b.N=%d but handled %d", b.N, handled)
  5474  	}
  5475  }
  5476  
  5477  const someResponse = "<html>some response</html>"
  5478  
  5479  // A Response that's just no bigger than 2KB, the buffer-before-chunking threshold.
  5480  var response = bytes.Repeat([]byte(someResponse), 2<<10/len(someResponse))
  5481  
  5482  // Both Content-Type and Content-Length set. Should be no buffering.
  5483  func BenchmarkServerHandlerTypeLen(b *testing.B) {
  5484  	benchmarkHandler(b, HandlerFunc(func(w ResponseWriter, r *Request) {
  5485  		w.Header().Set("Content-Type", "text/html")
  5486  		w.Header().Set("Content-Length", strconv.Itoa(len(response)))
  5487  		w.Write(response)
  5488  	}))
  5489  }
  5490  
  5491  // A Content-Type is set, but no length. No sniffing, but will count the Content-Length.
  5492  func BenchmarkServerHandlerNoLen(b *testing.B) {
  5493  	benchmarkHandler(b, HandlerFunc(func(w ResponseWriter, r *Request) {
  5494  		w.Header().Set("Content-Type", "text/html")
  5495  		w.Write(response)
  5496  	}))
  5497  }
  5498  
  5499  // A Content-Length is set, but the Content-Type will be sniffed.
  5500  func BenchmarkServerHandlerNoType(b *testing.B) {
  5501  	benchmarkHandler(b, HandlerFunc(func(w ResponseWriter, r *Request) {
  5502  		w.Header().Set("Content-Length", strconv.Itoa(len(response)))
  5503  		w.Write(response)
  5504  	}))
  5505  }
  5506  
  5507  // Neither a Content-Type or Content-Length, so sniffed and counted.
  5508  func BenchmarkServerHandlerNoHeader(b *testing.B) {
  5509  	benchmarkHandler(b, HandlerFunc(func(w ResponseWriter, r *Request) {
  5510  		w.Write(response)
  5511  	}))
  5512  }
  5513  
  5514  func benchmarkHandler(b *testing.B, h Handler) {
  5515  	b.ReportAllocs()
  5516  	req := reqBytes(`GET / HTTP/1.1
  5517  Host: golang.org
  5518  `)
  5519  	conn := &rwTestConn{
  5520  		Reader: &repeatReader{content: req, count: b.N},
  5521  		Writer: io.Discard,
  5522  		closec: make(chan bool, 1),
  5523  	}
  5524  	handled := 0
  5525  	handler := HandlerFunc(func(rw ResponseWriter, r *Request) {
  5526  		handled++
  5527  		h.ServeHTTP(rw, r)
  5528  	})
  5529  	ln := &oneConnListener{conn: conn}
  5530  	go Serve(ln, handler)
  5531  	<-conn.closec
  5532  	if b.N != handled {
  5533  		b.Errorf("b.N=%d but handled %d", b.N, handled)
  5534  	}
  5535  }
  5536  
  5537  func BenchmarkServerHijack(b *testing.B) {
  5538  	b.ReportAllocs()
  5539  	req := reqBytes(`GET / HTTP/1.1
  5540  Host: golang.org
  5541  `)
  5542  	h := HandlerFunc(func(w ResponseWriter, r *Request) {
  5543  		conn, _, err := w.(Hijacker).Hijack()
  5544  		if err != nil {
  5545  			panic(err)
  5546  		}
  5547  		conn.Close()
  5548  	})
  5549  	conn := &rwTestConn{
  5550  		Writer: io.Discard,
  5551  		closec: make(chan bool, 1),
  5552  	}
  5553  	ln := &oneConnListener{conn: conn}
  5554  	for i := 0; i < b.N; i++ {
  5555  		conn.Reader = bytes.NewReader(req)
  5556  		ln.conn = conn
  5557  		Serve(ln, h)
  5558  		<-conn.closec
  5559  	}
  5560  }
  5561  
  5562  func BenchmarkCloseNotifier(b *testing.B) { run(b, benchmarkCloseNotifier, []testMode{http1Mode}) }
  5563  func benchmarkCloseNotifier(b *testing.B, mode testMode) {
  5564  	b.ReportAllocs()
  5565  	b.StopTimer()
  5566  	sawClose := make(chan bool)
  5567  	ts := newClientServerTest(b, mode, HandlerFunc(func(rw ResponseWriter, req *Request) {
  5568  		<-rw.(CloseNotifier).CloseNotify()
  5569  		sawClose <- true
  5570  	})).ts
  5571  	b.StartTimer()
  5572  	for i := 0; i < b.N; i++ {
  5573  		conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  5574  		if err != nil {
  5575  			b.Fatalf("error dialing: %v", err)
  5576  		}
  5577  		_, err = fmt.Fprintf(conn, "GET / HTTP/1.1\r\nConnection: keep-alive\r\nHost: foo\r\n\r\n")
  5578  		if err != nil {
  5579  			b.Fatal(err)
  5580  		}
  5581  		conn.Close()
  5582  		<-sawClose
  5583  	}
  5584  	b.StopTimer()
  5585  }
  5586  
  5587  // Verify this doesn't race (Issue 16505)
  5588  func TestConcurrentServerServe(t *testing.T) {
  5589  	setParallel(t)
  5590  	for i := 0; i < 100; i++ {
  5591  		ln1 := &oneConnListener{conn: nil}
  5592  		ln2 := &oneConnListener{conn: nil}
  5593  		srv := Server{}
  5594  		go func() { srv.Serve(ln1) }()
  5595  		go func() { srv.Serve(ln2) }()
  5596  	}
  5597  }
  5598  
  5599  func TestServerIdleTimeout(t *testing.T) { run(t, testServerIdleTimeout, []testMode{http1Mode}) }
  5600  func testServerIdleTimeout(t *testing.T, mode testMode) {
  5601  	if testing.Short() {
  5602  		t.Skip("skipping in short mode")
  5603  	}
  5604  	runTimeSensitiveTest(t, []time.Duration{
  5605  		10 * time.Millisecond,
  5606  		100 * time.Millisecond,
  5607  		1 * time.Second,
  5608  		10 * time.Second,
  5609  	}, func(t *testing.T, readHeaderTimeout time.Duration) error {
  5610  		cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  5611  			io.Copy(io.Discard, r.Body)
  5612  			io.WriteString(w, r.RemoteAddr)
  5613  		}), func(ts *httptest.Server) {
  5614  			ts.Config.ReadHeaderTimeout = readHeaderTimeout
  5615  			ts.Config.IdleTimeout = 2 * readHeaderTimeout
  5616  		})
  5617  		defer cst.close()
  5618  		ts := cst.ts
  5619  		t.Logf("ReadHeaderTimeout = %v", ts.Config.ReadHeaderTimeout)
  5620  		t.Logf("IdleTimeout = %v", ts.Config.IdleTimeout)
  5621  		c := ts.Client()
  5622  
  5623  		get := func() (string, error) {
  5624  			res, err := c.Get(ts.URL)
  5625  			if err != nil {
  5626  				return "", err
  5627  			}
  5628  			defer res.Body.Close()
  5629  			slurp, err := io.ReadAll(res.Body)
  5630  			if err != nil {
  5631  				// If we're at this point the headers have definitely already been
  5632  				// read and the server is not idle, so neither timeout applies:
  5633  				// this should never fail.
  5634  				t.Fatal(err)
  5635  			}
  5636  			return string(slurp), nil
  5637  		}
  5638  
  5639  		a1, err := get()
  5640  		if err != nil {
  5641  			return err
  5642  		}
  5643  		a2, err := get()
  5644  		if err != nil {
  5645  			return err
  5646  		}
  5647  		if a1 != a2 {
  5648  			return fmt.Errorf("did requests on different connections")
  5649  		}
  5650  		time.Sleep(ts.Config.IdleTimeout * 3 / 2)
  5651  		a3, err := get()
  5652  		if err != nil {
  5653  			return err
  5654  		}
  5655  		if a2 == a3 {
  5656  			return fmt.Errorf("request three unexpectedly on same connection")
  5657  		}
  5658  
  5659  		// And test that ReadHeaderTimeout still works:
  5660  		conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  5661  		if err != nil {
  5662  			return err
  5663  		}
  5664  		defer conn.Close()
  5665  		conn.Write([]byte("GET / HTTP/1.1\r\nHost: foo.com\r\n"))
  5666  		time.Sleep(ts.Config.ReadHeaderTimeout * 2)
  5667  		if _, err := io.CopyN(io.Discard, conn, 1); err == nil {
  5668  			return fmt.Errorf("copy byte succeeded; want err")
  5669  		}
  5670  
  5671  		return nil
  5672  	})
  5673  }
  5674  
  5675  func get(t *testing.T, c *Client, url string) string {
  5676  	res, err := c.Get(url)
  5677  	if err != nil {
  5678  		t.Fatal(err)
  5679  	}
  5680  	defer res.Body.Close()
  5681  	slurp, err := io.ReadAll(res.Body)
  5682  	if err != nil {
  5683  		t.Fatal(err)
  5684  	}
  5685  	return string(slurp)
  5686  }
  5687  
  5688  // Tests that calls to Server.SetKeepAlivesEnabled(false) closes any
  5689  // currently-open connections.
  5690  func TestServerSetKeepAlivesEnabledClosesConns(t *testing.T) {
  5691  	run(t, testServerSetKeepAlivesEnabledClosesConns, []testMode{http1Mode})
  5692  }
  5693  func testServerSetKeepAlivesEnabledClosesConns(t *testing.T, mode testMode) {
  5694  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  5695  		io.WriteString(w, r.RemoteAddr)
  5696  	})).ts
  5697  
  5698  	c := ts.Client()
  5699  	tr := c.Transport.(*Transport)
  5700  
  5701  	get := func() string { return get(t, c, ts.URL) }
  5702  
  5703  	a1, a2 := get(), get()
  5704  	if a1 == a2 {
  5705  		t.Logf("made two requests from a single conn %q (as expected)", a1)
  5706  	} else {
  5707  		t.Errorf("server reported requests from %q and %q; expected same connection", a1, a2)
  5708  	}
  5709  
  5710  	// The two requests should have used the same connection,
  5711  	// and there should not have been a second connection that
  5712  	// was created by racing dial against reuse.
  5713  	// (The first get was completed when the second get started.)
  5714  	if conns := tr.IdleConnStrsForTesting(); len(conns) != 1 {
  5715  		t.Errorf("found %d idle conns (%q); want 1", len(conns), conns)
  5716  	}
  5717  
  5718  	// SetKeepAlivesEnabled should discard idle conns.
  5719  	ts.Config.SetKeepAlivesEnabled(false)
  5720  
  5721  	waitCondition(t, 10*time.Millisecond, func(d time.Duration) bool {
  5722  		if conns := tr.IdleConnStrsForTesting(); len(conns) > 0 {
  5723  			if d > 0 {
  5724  				t.Logf("idle conns %v after SetKeepAlivesEnabled called = %q; waiting for empty", d, conns)
  5725  			}
  5726  			return false
  5727  		}
  5728  		return true
  5729  	})
  5730  
  5731  	// If we make a third request it should use a new connection, but in general
  5732  	// we have no way to verify that: the new connection could happen to reuse the
  5733  	// exact same ports from the previous connection.
  5734  }
  5735  
  5736  func TestServerShutdown(t *testing.T) { run(t, testServerShutdown) }
  5737  func testServerShutdown(t *testing.T, mode testMode) {
  5738  	var cst *clientServerTest
  5739  
  5740  	var once sync.Once
  5741  	statesRes := make(chan map[ConnState]int, 1)
  5742  	shutdownRes := make(chan error, 1)
  5743  	gotOnShutdown := make(chan struct{})
  5744  	handler := HandlerFunc(func(w ResponseWriter, r *Request) {
  5745  		first := false
  5746  		once.Do(func() {
  5747  			statesRes <- cst.ts.Config.ExportAllConnsByState()
  5748  			go func() {
  5749  				shutdownRes <- cst.ts.Config.Shutdown(context.Background())
  5750  			}()
  5751  			first = true
  5752  		})
  5753  
  5754  		if first {
  5755  			// Shutdown is graceful, so it should not interrupt this in-flight response
  5756  			// but should reject new requests. (Since this request is still in flight,
  5757  			// the server's port should not be reused for another server yet.)
  5758  			<-gotOnShutdown
  5759  			// TODO(#59038): The HTTP/2 server empirically does not always reject new
  5760  			// requests. As a workaround, loop until we see a failure.
  5761  			for !t.Failed() {
  5762  				res, err := cst.c.Get(cst.ts.URL)
  5763  				if err != nil {
  5764  					break
  5765  				}
  5766  				out, _ := io.ReadAll(res.Body)
  5767  				res.Body.Close()
  5768  				if mode == http2Mode {
  5769  					t.Logf("%v: unexpected success (%q). Listener should be closed before OnShutdown is called.", cst.ts.URL, out)
  5770  					t.Logf("Retrying to work around https://go.dev/issue/59038.")
  5771  					continue
  5772  				}
  5773  				t.Errorf("%v: unexpected success (%q). Listener should be closed before OnShutdown is called.", cst.ts.URL, out)
  5774  			}
  5775  		}
  5776  
  5777  		io.WriteString(w, r.RemoteAddr)
  5778  	})
  5779  
  5780  	cst = newClientServerTest(t, mode, handler, func(srv *httptest.Server) {
  5781  		srv.Config.RegisterOnShutdown(func() { close(gotOnShutdown) })
  5782  	})
  5783  
  5784  	out := get(t, cst.c, cst.ts.URL) // calls t.Fail on failure
  5785  	t.Logf("%v: %q", cst.ts.URL, out)
  5786  
  5787  	if err := <-shutdownRes; err != nil {
  5788  		t.Fatalf("Shutdown: %v", err)
  5789  	}
  5790  	<-gotOnShutdown // Will hang if RegisterOnShutdown is broken.
  5791  
  5792  	if states := <-statesRes; states[StateActive] != 1 {
  5793  		t.Errorf("connection in wrong state, %v", states)
  5794  	}
  5795  }
  5796  
  5797  func TestServerShutdownStateNew(t *testing.T) { runSynctest(t, testServerShutdownStateNew) }
  5798  func testServerShutdownStateNew(t testing.TB, mode testMode) {
  5799  	if testing.Short() {
  5800  		t.Skip("test takes 5-6 seconds; skipping in short mode")
  5801  	}
  5802  
  5803  	listener := fakeNetListen()
  5804  	defer listener.Close()
  5805  
  5806  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  5807  		// nothing.
  5808  	}), func(ts *httptest.Server) {
  5809  		ts.Listener.Close()
  5810  		ts.Listener = listener
  5811  		// Ignore irrelevant error about TLS handshake failure.
  5812  		ts.Config.ErrorLog = log.New(io.Discard, "", 0)
  5813  	}).ts
  5814  
  5815  	// Start a connection but never write to it.
  5816  	c := listener.connect()
  5817  	defer c.Close()
  5818  	synctest.Wait()
  5819  
  5820  	shutdownRes := runAsync(func() (struct{}, error) {
  5821  		return struct{}{}, ts.Config.Shutdown(context.Background())
  5822  	})
  5823  
  5824  	// TODO(#59037): This timeout is hard-coded in closeIdleConnections.
  5825  	// It is undocumented, and some users may find it surprising.
  5826  	// Either document it, or switch to a less surprising behavior.
  5827  	const expectTimeout = 5 * time.Second
  5828  
  5829  	// Wait until just before the expected timeout.
  5830  	time.Sleep(expectTimeout - 1)
  5831  	synctest.Wait()
  5832  	if shutdownRes.done() {
  5833  		t.Fatal("shutdown too soon")
  5834  	}
  5835  	if c.IsClosedByPeer() {
  5836  		t.Fatal("connection was closed by server too soon")
  5837  	}
  5838  
  5839  	// closeIdleConnections isn't precise about its actual shutdown time.
  5840  	// Wait long enough for it to definitely have shut down.
  5841  	//
  5842  	// (It would be good to make closeIdleConnections less sloppy.)
  5843  	time.Sleep(2 * time.Second)
  5844  	synctest.Wait()
  5845  	if _, err := shutdownRes.result(); err != nil {
  5846  		t.Fatalf("Shutdown() = %v, want complete", err)
  5847  	}
  5848  	if !c.IsClosedByPeer() {
  5849  		t.Fatalf("connection was not closed by server after shutdown")
  5850  	}
  5851  }
  5852  
  5853  // Issue 17878: tests that we can call Close twice.
  5854  func TestServerCloseDeadlock(t *testing.T) {
  5855  	var s Server
  5856  	s.Close()
  5857  	s.Close()
  5858  }
  5859  
  5860  // Issue 17717: tests that Server.SetKeepAlivesEnabled is respected by
  5861  // both HTTP/1 and HTTP/2.
  5862  func TestServerKeepAlivesEnabled(t *testing.T) { run(t, testServerKeepAlivesEnabled, testNotParallel) }
  5863  func testServerKeepAlivesEnabled(t *testing.T, mode testMode) {
  5864  	if mode == http2Mode {
  5865  		restore := ExportSetH2GoawayTimeout(10 * time.Millisecond)
  5866  		defer restore()
  5867  	}
  5868  	// Not parallel: messes with global variable. (http2goAwayTimeout)
  5869  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {}))
  5870  	defer cst.close()
  5871  	srv := cst.ts.Config
  5872  	srv.SetKeepAlivesEnabled(false)
  5873  	for try := 0; try < 2; try++ {
  5874  		waitCondition(t, 10*time.Millisecond, func(d time.Duration) bool {
  5875  			if !srv.ExportAllConnsIdle() {
  5876  				if d > 0 {
  5877  					t.Logf("test server still has active conns after %v", d)
  5878  				}
  5879  				return false
  5880  			}
  5881  			return true
  5882  		})
  5883  		conns := 0
  5884  		var info httptrace.GotConnInfo
  5885  		ctx := httptrace.WithClientTrace(context.Background(), &httptrace.ClientTrace{
  5886  			GotConn: func(v httptrace.GotConnInfo) {
  5887  				conns++
  5888  				info = v
  5889  			},
  5890  		})
  5891  		req, err := NewRequestWithContext(ctx, "GET", cst.ts.URL, nil)
  5892  		if err != nil {
  5893  			t.Fatal(err)
  5894  		}
  5895  		res, err := cst.c.Do(req)
  5896  		if err != nil {
  5897  			t.Fatal(err)
  5898  		}
  5899  		res.Body.Close()
  5900  		if conns != 1 {
  5901  			t.Fatalf("request %v: got %v conns, want 1", try, conns)
  5902  		}
  5903  		if info.Reused || info.WasIdle {
  5904  			t.Fatalf("request %v: Reused=%v (want false), WasIdle=%v (want false)", try, info.Reused, info.WasIdle)
  5905  		}
  5906  	}
  5907  }
  5908  
  5909  // Issue 18447: test that the Server's ReadTimeout is stopped while
  5910  // the server's doing its 1-byte background read between requests,
  5911  // waiting for the connection to maybe close.
  5912  func TestServerCancelsReadTimeoutWhenIdle(t *testing.T) { run(t, testServerCancelsReadTimeoutWhenIdle) }
  5913  func testServerCancelsReadTimeoutWhenIdle(t *testing.T, mode testMode) {
  5914  	runTimeSensitiveTest(t, []time.Duration{
  5915  		10 * time.Millisecond,
  5916  		50 * time.Millisecond,
  5917  		250 * time.Millisecond,
  5918  		time.Second,
  5919  		2 * time.Second,
  5920  	}, func(t *testing.T, timeout time.Duration) error {
  5921  		cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  5922  			select {
  5923  			case <-time.After(2 * timeout):
  5924  				fmt.Fprint(w, "ok")
  5925  			case <-r.Context().Done():
  5926  				fmt.Fprint(w, r.Context().Err())
  5927  			}
  5928  		}), func(ts *httptest.Server) {
  5929  			ts.Config.ReadTimeout = timeout
  5930  			t.Logf("Server.Config.ReadTimeout = %v", timeout)
  5931  		})
  5932  		defer cst.close()
  5933  		ts := cst.ts
  5934  
  5935  		var retries atomic.Int32
  5936  		cst.c.Transport.(*Transport).Proxy = func(*Request) (*url.URL, error) {
  5937  			if retries.Add(1) != 1 {
  5938  				return nil, errors.New("too many retries")
  5939  			}
  5940  			return nil, nil
  5941  		}
  5942  
  5943  		c := ts.Client()
  5944  
  5945  		res, err := c.Get(ts.URL)
  5946  		if err != nil {
  5947  			return fmt.Errorf("Get: %v", err)
  5948  		}
  5949  		slurp, err := io.ReadAll(res.Body)
  5950  		res.Body.Close()
  5951  		if err != nil {
  5952  			return fmt.Errorf("Body ReadAll: %v", err)
  5953  		}
  5954  		if string(slurp) != "ok" {
  5955  			return fmt.Errorf("got: %q, want ok", slurp)
  5956  		}
  5957  		return nil
  5958  	})
  5959  }
  5960  
  5961  // Issue 54784: test that the Server's ReadHeaderTimeout only starts once the
  5962  // beginning of a request has been received, rather than including time the
  5963  // connection spent idle.
  5964  func TestServerCancelsReadHeaderTimeoutWhenIdle(t *testing.T) {
  5965  	run(t, testServerCancelsReadHeaderTimeoutWhenIdle, []testMode{http1Mode})
  5966  }
  5967  func testServerCancelsReadHeaderTimeoutWhenIdle(t *testing.T, mode testMode) {
  5968  	runTimeSensitiveTest(t, []time.Duration{
  5969  		10 * time.Millisecond,
  5970  		50 * time.Millisecond,
  5971  		250 * time.Millisecond,
  5972  		time.Second,
  5973  		2 * time.Second,
  5974  	}, func(t *testing.T, timeout time.Duration) error {
  5975  		cst := newClientServerTest(t, mode, serve(200), func(ts *httptest.Server) {
  5976  			ts.Config.ReadHeaderTimeout = timeout
  5977  			ts.Config.IdleTimeout = 0 // disable idle timeout
  5978  		})
  5979  		defer cst.close()
  5980  		ts := cst.ts
  5981  
  5982  		// rather than using an http.Client, create a single connection, so that
  5983  		// we can ensure this connection is not closed.
  5984  		conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  5985  		if err != nil {
  5986  			t.Fatalf("dial failed: %v", err)
  5987  		}
  5988  		br := bufio.NewReader(conn)
  5989  		defer conn.Close()
  5990  
  5991  		if _, err := conn.Write([]byte("GET / HTTP/1.1\r\nHost: e.com\r\n\r\n")); err != nil {
  5992  			return fmt.Errorf("writing first request failed: %v", err)
  5993  		}
  5994  
  5995  		if _, err := ReadResponse(br, nil); err != nil {
  5996  			return fmt.Errorf("first response (before timeout) failed: %v", err)
  5997  		}
  5998  
  5999  		// wait for longer than the server's ReadHeaderTimeout, and then send
  6000  		// another request
  6001  		time.Sleep(timeout * 3 / 2)
  6002  
  6003  		if _, err := conn.Write([]byte("GET / HTTP/1.1\r\nHost: e.com\r\n\r\n")); err != nil {
  6004  			return fmt.Errorf("writing second request failed: %v", err)
  6005  		}
  6006  
  6007  		if _, err := ReadResponse(br, nil); err != nil {
  6008  			return fmt.Errorf("second response (after timeout) failed: %v", err)
  6009  		}
  6010  
  6011  		return nil
  6012  	})
  6013  }
  6014  
  6015  // runTimeSensitiveTest runs test with the provided durations until one passes.
  6016  // If they all fail, t.Fatal is called with the last one's duration and error value.
  6017  func runTimeSensitiveTest(t *testing.T, durations []time.Duration, test func(t *testing.T, d time.Duration) error) {
  6018  	for i, d := range durations {
  6019  		err := test(t, d)
  6020  		if err == nil {
  6021  			return
  6022  		}
  6023  		if i == len(durations)-1 || t.Failed() {
  6024  			t.Fatalf("failed with duration %v: %v", d, err)
  6025  		}
  6026  		t.Logf("retrying after error with duration %v: %v", d, err)
  6027  	}
  6028  }
  6029  
  6030  // Issue 18535: test that the Server doesn't try to do a background
  6031  // read if it's already done one.
  6032  func TestServerDuplicateBackgroundRead(t *testing.T) {
  6033  	run(t, testServerDuplicateBackgroundRead, []testMode{http1Mode})
  6034  }
  6035  func testServerDuplicateBackgroundRead(t *testing.T, mode testMode) {
  6036  	if runtime.GOOS == "netbsd" && runtime.GOARCH == "arm" {
  6037  		testenv.SkipFlaky(t, 24826)
  6038  	}
  6039  
  6040  	goroutines := 5
  6041  	requests := 2000
  6042  	if testing.Short() {
  6043  		goroutines = 3
  6044  		requests = 100
  6045  	}
  6046  
  6047  	hts := newClientServerTest(t, mode, HandlerFunc(NotFound)).ts
  6048  
  6049  	reqBytes := []byte("GET / HTTP/1.1\r\nHost: e.com\r\n\r\n")
  6050  
  6051  	var wg sync.WaitGroup
  6052  	for i := 0; i < goroutines; i++ {
  6053  		wg.Add(1)
  6054  		go func() {
  6055  			defer wg.Done()
  6056  			cn, err := net.Dial("tcp", hts.Listener.Addr().String())
  6057  			if err != nil {
  6058  				t.Error(err)
  6059  				return
  6060  			}
  6061  			defer cn.Close()
  6062  
  6063  			wg.Add(1)
  6064  			go func() {
  6065  				defer wg.Done()
  6066  				io.Copy(io.Discard, cn)
  6067  			}()
  6068  
  6069  			for j := 0; j < requests; j++ {
  6070  				if t.Failed() {
  6071  					return
  6072  				}
  6073  				_, err := cn.Write(reqBytes)
  6074  				if err != nil {
  6075  					t.Error(err)
  6076  					return
  6077  				}
  6078  			}
  6079  		}()
  6080  	}
  6081  	wg.Wait()
  6082  }
  6083  
  6084  // Test that the bufio.Reader returned by Hijack includes any buffered
  6085  // byte (from the Server's backgroundRead) in its buffer. We want the
  6086  // Handler code to be able to tell that a byte is available via
  6087  // bufio.Reader.Buffered(), without resorting to Reading it
  6088  // (potentially blocking) to get at it.
  6089  func TestServerHijackGetsBackgroundByte(t *testing.T) {
  6090  	run(t, testServerHijackGetsBackgroundByte, []testMode{http1Mode})
  6091  }
  6092  func testServerHijackGetsBackgroundByte(t *testing.T, mode testMode) {
  6093  	if runtime.GOOS == "plan9" {
  6094  		t.Skip("skipping test; see https://golang.org/issue/18657")
  6095  	}
  6096  	done := make(chan struct{})
  6097  	inHandler := make(chan bool, 1)
  6098  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  6099  		defer close(done)
  6100  
  6101  		// Tell the client to send more data after the GET request.
  6102  		inHandler <- true
  6103  
  6104  		conn, buf, err := w.(Hijacker).Hijack()
  6105  		if err != nil {
  6106  			t.Error(err)
  6107  			return
  6108  		}
  6109  		defer conn.Close()
  6110  
  6111  		peek, err := buf.Reader.Peek(3)
  6112  		if string(peek) != "foo" || err != nil {
  6113  			t.Errorf("Peek = %q, %v; want foo, nil", peek, err)
  6114  		}
  6115  
  6116  		select {
  6117  		case <-r.Context().Done():
  6118  			t.Error("context unexpectedly canceled")
  6119  		default:
  6120  		}
  6121  	})).ts
  6122  
  6123  	cn, err := net.Dial("tcp", ts.Listener.Addr().String())
  6124  	if err != nil {
  6125  		t.Fatal(err)
  6126  	}
  6127  	defer cn.Close()
  6128  	if _, err := cn.Write([]byte("GET / HTTP/1.1\r\nHost: e.com\r\n\r\n")); err != nil {
  6129  		t.Fatal(err)
  6130  	}
  6131  	<-inHandler
  6132  	if _, err := cn.Write([]byte("foo")); err != nil {
  6133  		t.Fatal(err)
  6134  	}
  6135  
  6136  	if err := cn.(*net.TCPConn).CloseWrite(); err != nil {
  6137  		t.Fatal(err)
  6138  	}
  6139  	<-done
  6140  }
  6141  
  6142  // Like TestServerHijackGetsBackgroundByte above but sending a
  6143  // immediate 1MB of data to the server to fill up the server's 4KB
  6144  // buffer.
  6145  func TestServerHijackGetsBackgroundByte_big(t *testing.T) {
  6146  	run(t, testServerHijackGetsBackgroundByte_big, []testMode{http1Mode})
  6147  }
  6148  func testServerHijackGetsBackgroundByte_big(t *testing.T, mode testMode) {
  6149  	if runtime.GOOS == "plan9" {
  6150  		t.Skip("skipping test; see https://golang.org/issue/18657")
  6151  	}
  6152  	done := make(chan struct{})
  6153  	const size = 8 << 10
  6154  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  6155  		defer close(done)
  6156  
  6157  		conn, buf, err := w.(Hijacker).Hijack()
  6158  		if err != nil {
  6159  			t.Error(err)
  6160  			return
  6161  		}
  6162  		defer conn.Close()
  6163  		slurp, err := io.ReadAll(buf.Reader)
  6164  		if err != nil {
  6165  			t.Errorf("Copy: %v", err)
  6166  		}
  6167  		allX := true
  6168  		for _, v := range slurp {
  6169  			if v != 'x' {
  6170  				allX = false
  6171  			}
  6172  		}
  6173  		if len(slurp) != size {
  6174  			t.Errorf("read %d; want %d", len(slurp), size)
  6175  		} else if !allX {
  6176  			t.Errorf("read %q; want %d 'x'", slurp, size)
  6177  		}
  6178  	})).ts
  6179  
  6180  	cn, err := net.Dial("tcp", ts.Listener.Addr().String())
  6181  	if err != nil {
  6182  		t.Fatal(err)
  6183  	}
  6184  	defer cn.Close()
  6185  	if _, err := fmt.Fprintf(cn, "GET / HTTP/1.1\r\nHost: e.com\r\n\r\n%s",
  6186  		strings.Repeat("x", size)); err != nil {
  6187  		t.Fatal(err)
  6188  	}
  6189  	if err := cn.(*net.TCPConn).CloseWrite(); err != nil {
  6190  		t.Fatal(err)
  6191  	}
  6192  
  6193  	<-done
  6194  }
  6195  
  6196  // Issue 18319: test that the Server validates the request method.
  6197  func TestServerValidatesMethod(t *testing.T) {
  6198  	tests := []struct {
  6199  		method string
  6200  		want   int
  6201  	}{
  6202  		{"GET", 200},
  6203  		{"GE(T", 400},
  6204  	}
  6205  	for _, tt := range tests {
  6206  		conn := newTestConn()
  6207  		io.WriteString(&conn.readBuf, tt.method+" / HTTP/1.1\r\nHost: foo.example\r\n\r\n")
  6208  
  6209  		ln := &oneConnListener{conn}
  6210  		go Serve(ln, serve(200))
  6211  		<-conn.closec
  6212  		res, err := ReadResponse(bufio.NewReader(&conn.writeBuf), nil)
  6213  		if err != nil {
  6214  			t.Errorf("For %s, ReadResponse: %v", tt.method, res)
  6215  			continue
  6216  		}
  6217  		if res.StatusCode != tt.want {
  6218  			t.Errorf("For %s, Status = %d; want %d", tt.method, res.StatusCode, tt.want)
  6219  		}
  6220  	}
  6221  }
  6222  
  6223  // Listener for TestServerListenNotComparableListener.
  6224  type eofListenerNotComparable []int
  6225  
  6226  func (eofListenerNotComparable) Accept() (net.Conn, error) { return nil, io.EOF }
  6227  func (eofListenerNotComparable) Addr() net.Addr            { return nil }
  6228  func (eofListenerNotComparable) Close() error              { return nil }
  6229  
  6230  // Issue 24812: don't crash on non-comparable Listener
  6231  func TestServerListenNotComparableListener(t *testing.T) {
  6232  	var s Server
  6233  	s.Serve(make(eofListenerNotComparable, 1)) // used to panic
  6234  }
  6235  
  6236  // countCloseListener is a Listener wrapper that counts the number of Close calls.
  6237  type countCloseListener struct {
  6238  	net.Listener
  6239  	closes int32 // atomic
  6240  }
  6241  
  6242  func (p *countCloseListener) Close() error {
  6243  	var err error
  6244  	if n := atomic.AddInt32(&p.closes, 1); n == 1 && p.Listener != nil {
  6245  		err = p.Listener.Close()
  6246  	}
  6247  	return err
  6248  }
  6249  
  6250  // Issue 24803: don't call Listener.Close on Server.Shutdown.
  6251  func TestServerCloseListenerOnce(t *testing.T) {
  6252  	setParallel(t)
  6253  	defer afterTest(t)
  6254  
  6255  	ln := newLocalListener(t)
  6256  	defer ln.Close()
  6257  
  6258  	cl := &countCloseListener{Listener: ln}
  6259  	server := &Server{}
  6260  	sdone := make(chan bool, 1)
  6261  
  6262  	go func() {
  6263  		server.Serve(cl)
  6264  		sdone <- true
  6265  	}()
  6266  	time.Sleep(10 * time.Millisecond)
  6267  	server.Shutdown(context.Background())
  6268  	ln.Close()
  6269  	<-sdone
  6270  
  6271  	nclose := atomic.LoadInt32(&cl.closes)
  6272  	if nclose != 1 {
  6273  		t.Errorf("Close calls = %v; want 1", nclose)
  6274  	}
  6275  }
  6276  
  6277  // Issue 20239: don't block in Serve if Shutdown is called first.
  6278  func TestServerShutdownThenServe(t *testing.T) {
  6279  	var srv Server
  6280  	cl := &countCloseListener{Listener: nil}
  6281  	srv.Shutdown(context.Background())
  6282  	got := srv.Serve(cl)
  6283  	if got != ErrServerClosed {
  6284  		t.Errorf("Serve err = %v; want ErrServerClosed", got)
  6285  	}
  6286  	nclose := atomic.LoadInt32(&cl.closes)
  6287  	if nclose != 1 {
  6288  		t.Errorf("Close calls = %v; want 1", nclose)
  6289  	}
  6290  }
  6291  
  6292  // Issue 23351: document and test behavior of ServeMux with ports
  6293  func TestStripPortFromHost(t *testing.T) {
  6294  	mux := NewServeMux()
  6295  
  6296  	mux.HandleFunc("example.com/", func(w ResponseWriter, r *Request) {
  6297  		fmt.Fprintf(w, "OK")
  6298  	})
  6299  	mux.HandleFunc("example.com:9000/", func(w ResponseWriter, r *Request) {
  6300  		fmt.Fprintf(w, "uh-oh!")
  6301  	})
  6302  
  6303  	req := httptest.NewRequest("GET", "http://example.com:9000/", nil)
  6304  	rw := httptest.NewRecorder()
  6305  
  6306  	mux.ServeHTTP(rw, req)
  6307  
  6308  	response := rw.Body.String()
  6309  	if response != "OK" {
  6310  		t.Errorf("Response gotten was %q", response)
  6311  	}
  6312  }
  6313  
  6314  func TestServerContexts(t *testing.T) { run(t, testServerContexts) }
  6315  func testServerContexts(t *testing.T, mode testMode) {
  6316  	type baseKey struct{}
  6317  	type connKey struct{}
  6318  	ch := make(chan context.Context, 1)
  6319  	ts := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, r *Request) {
  6320  		ch <- r.Context()
  6321  	}), func(ts *httptest.Server) {
  6322  		ts.Config.BaseContext = func(ln net.Listener) context.Context {
  6323  			if strings.Contains(reflect.TypeOf(ln).String(), "onceClose") {
  6324  				t.Errorf("unexpected onceClose listener type %T", ln)
  6325  			}
  6326  			return context.WithValue(context.Background(), baseKey{}, "base")
  6327  		}
  6328  		ts.Config.ConnContext = func(ctx context.Context, c net.Conn) context.Context {
  6329  			if got, want := ctx.Value(baseKey{}), "base"; got != want {
  6330  				t.Errorf("in ConnContext, base context key = %#v; want %q", got, want)
  6331  			}
  6332  			return context.WithValue(ctx, connKey{}, "conn")
  6333  		}
  6334  	}).ts
  6335  	res, err := ts.Client().Get(ts.URL)
  6336  	if err != nil {
  6337  		t.Fatal(err)
  6338  	}
  6339  	res.Body.Close()
  6340  	ctx := <-ch
  6341  	if got, want := ctx.Value(baseKey{}), "base"; got != want {
  6342  		t.Errorf("base context key = %#v; want %q", got, want)
  6343  	}
  6344  	if got, want := ctx.Value(connKey{}), "conn"; got != want {
  6345  		t.Errorf("conn context key = %#v; want %q", got, want)
  6346  	}
  6347  }
  6348  
  6349  // Issue 35750: check ConnContext not modifying context for other connections
  6350  func TestConnContextNotModifyingAllContexts(t *testing.T) {
  6351  	run(t, testConnContextNotModifyingAllContexts)
  6352  }
  6353  func testConnContextNotModifyingAllContexts(t *testing.T, mode testMode) {
  6354  	type connKey struct{}
  6355  	ts := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, r *Request) {
  6356  		rw.Header().Set("Connection", "close")
  6357  	}), func(ts *httptest.Server) {
  6358  		ts.Config.ConnContext = func(ctx context.Context, c net.Conn) context.Context {
  6359  			if got := ctx.Value(connKey{}); got != nil {
  6360  				t.Errorf("in ConnContext, unexpected context key = %#v", got)
  6361  			}
  6362  			return context.WithValue(ctx, connKey{}, "conn")
  6363  		}
  6364  	}).ts
  6365  
  6366  	var res *Response
  6367  	var err error
  6368  
  6369  	res, err = ts.Client().Get(ts.URL)
  6370  	if err != nil {
  6371  		t.Fatal(err)
  6372  	}
  6373  	res.Body.Close()
  6374  
  6375  	res, err = ts.Client().Get(ts.URL)
  6376  	if err != nil {
  6377  		t.Fatal(err)
  6378  	}
  6379  	res.Body.Close()
  6380  }
  6381  
  6382  // Issue 30710: ensure that as per the spec, a server responds
  6383  // with 501 Not Implemented for unsupported transfer-encodings.
  6384  func TestUnsupportedTransferEncodingsReturn501(t *testing.T) {
  6385  	run(t, testUnsupportedTransferEncodingsReturn501, []testMode{http1Mode})
  6386  }
  6387  func testUnsupportedTransferEncodingsReturn501(t *testing.T, mode testMode) {
  6388  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  6389  		w.Write([]byte("Hello, World!"))
  6390  	})).ts
  6391  
  6392  	serverURL, err := url.Parse(cst.URL)
  6393  	if err != nil {
  6394  		t.Fatalf("Failed to parse server URL: %v", err)
  6395  	}
  6396  
  6397  	unsupportedTEs := []string{
  6398  		"fugazi",
  6399  		"foo-bar",
  6400  		"unknown",
  6401  		`" chunked"`,
  6402  	}
  6403  
  6404  	for _, badTE := range unsupportedTEs {
  6405  		http1ReqBody := fmt.Sprintf(""+
  6406  			"POST / HTTP/1.1\r\nConnection: close\r\n"+
  6407  			"Host: localhost\r\nTransfer-Encoding: %s\r\n\r\n", badTE)
  6408  
  6409  		gotBody, err := fetchWireResponse(serverURL.Host, []byte(http1ReqBody))
  6410  		if err != nil {
  6411  			t.Errorf("%q. unexpected error: %v", badTE, err)
  6412  			continue
  6413  		}
  6414  
  6415  		wantBody := fmt.Sprintf("" +
  6416  			"HTTP/1.1 501 Not Implemented\r\nContent-Type: text/plain; charset=utf-8\r\n" +
  6417  			"Connection: close\r\n\r\nUnsupported transfer encoding")
  6418  
  6419  		if string(gotBody) != wantBody {
  6420  			t.Errorf("%q. body\ngot\n%q\nwant\n%q", badTE, gotBody, wantBody)
  6421  		}
  6422  	}
  6423  }
  6424  
  6425  // Issue 31753: don't sniff when Content-Encoding is set
  6426  func TestContentEncodingNoSniffing(t *testing.T) { run(t, testContentEncodingNoSniffing) }
  6427  func testContentEncodingNoSniffing(t *testing.T, mode testMode) {
  6428  	type setting struct {
  6429  		name string
  6430  		body []byte
  6431  
  6432  		// setting contentEncoding as an interface instead of a string
  6433  		// directly, so as to differentiate between 3 states:
  6434  		//    unset, empty string "" and set string "foo/bar".
  6435  		contentEncoding any
  6436  		wantContentType string
  6437  	}
  6438  
  6439  	settings := []*setting{
  6440  		{
  6441  			name:            "gzip content-encoding, gzipped", // don't sniff.
  6442  			contentEncoding: "application/gzip",
  6443  			wantContentType: "",
  6444  			body: func() []byte {
  6445  				buf := new(bytes.Buffer)
  6446  				gzw := gzip.NewWriter(buf)
  6447  				gzw.Write([]byte("doctype html><p>Hello</p>"))
  6448  				gzw.Close()
  6449  				return buf.Bytes()
  6450  			}(),
  6451  		},
  6452  		{
  6453  			name:            "zlib content-encoding, zlibbed", // don't sniff.
  6454  			contentEncoding: "application/zlib",
  6455  			wantContentType: "",
  6456  			body: func() []byte {
  6457  				buf := new(bytes.Buffer)
  6458  				zw := zlib.NewWriter(buf)
  6459  				zw.Write([]byte("doctype html><p>Hello</p>"))
  6460  				zw.Close()
  6461  				return buf.Bytes()
  6462  			}(),
  6463  		},
  6464  		{
  6465  			name:            "no content-encoding", // must sniff.
  6466  			wantContentType: "application/x-gzip",
  6467  			body: func() []byte {
  6468  				buf := new(bytes.Buffer)
  6469  				gzw := gzip.NewWriter(buf)
  6470  				gzw.Write([]byte("doctype html><p>Hello</p>"))
  6471  				gzw.Close()
  6472  				return buf.Bytes()
  6473  			}(),
  6474  		},
  6475  		{
  6476  			name:            "phony content-encoding", // don't sniff.
  6477  			contentEncoding: "foo/bar",
  6478  			body:            []byte("doctype html><p>Hello</p>"),
  6479  		},
  6480  		{
  6481  			name:            "empty but set content-encoding",
  6482  			contentEncoding: "",
  6483  			wantContentType: "audio/mpeg",
  6484  			body:            []byte("ID3"),
  6485  		},
  6486  	}
  6487  
  6488  	for _, tt := range settings {
  6489  		t.Run(tt.name, func(t *testing.T) {
  6490  			cst := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, r *Request) {
  6491  				if tt.contentEncoding != nil {
  6492  					rw.Header().Set("Content-Encoding", tt.contentEncoding.(string))
  6493  				}
  6494  				rw.Write(tt.body)
  6495  			}))
  6496  
  6497  			res, err := cst.c.Get(cst.ts.URL)
  6498  			if err != nil {
  6499  				t.Fatalf("Failed to fetch URL: %v", err)
  6500  			}
  6501  			defer res.Body.Close()
  6502  
  6503  			if g, w := res.Header.Get("Content-Encoding"), tt.contentEncoding; g != w {
  6504  				if w != nil { // The case where contentEncoding was set explicitly.
  6505  					t.Errorf("Content-Encoding mismatch\n\tgot:  %q\n\twant: %q", g, w)
  6506  				} else if g != "" { // "" should be the equivalent when the contentEncoding is unset.
  6507  					t.Errorf("Unexpected Content-Encoding %q", g)
  6508  				}
  6509  			}
  6510  
  6511  			if g, w := res.Header.Get("Content-Type"), tt.wantContentType; g != w {
  6512  				t.Errorf("Content-Type mismatch\n\tgot:  %q\n\twant: %q", g, w)
  6513  			}
  6514  		})
  6515  	}
  6516  }
  6517  
  6518  // Issue 30803: ensure that TimeoutHandler logs spurious
  6519  // WriteHeader calls, for consistency with other Handlers.
  6520  func TestTimeoutHandlerSuperfluousLogs(t *testing.T) {
  6521  	run(t, testTimeoutHandlerSuperfluousLogs, []testMode{http1Mode})
  6522  }
  6523  func testTimeoutHandlerSuperfluousLogs(t *testing.T, mode testMode) {
  6524  	if testing.Short() {
  6525  		t.Skip("skipping in short mode")
  6526  	}
  6527  
  6528  	pc, curFile, _, _ := runtime.Caller(0)
  6529  	curFileBaseName := filepath.Base(curFile)
  6530  	testFuncName := runtime.FuncForPC(pc).Name()
  6531  
  6532  	timeoutMsg := "timed out here!"
  6533  
  6534  	tests := []struct {
  6535  		name        string
  6536  		mustTimeout bool
  6537  		wantResp    string
  6538  	}{
  6539  		{
  6540  			name:     "return before timeout",
  6541  			wantResp: "HTTP/1.1 404 Not Found\r\nContent-Length: 0\r\n\r\n",
  6542  		},
  6543  		{
  6544  			name:        "return after timeout",
  6545  			mustTimeout: true,
  6546  			wantResp: fmt.Sprintf("HTTP/1.1 503 Service Unavailable\r\nContent-Length: %d\r\n\r\n%s",
  6547  				len(timeoutMsg), timeoutMsg),
  6548  		},
  6549  	}
  6550  
  6551  	for _, tt := range tests {
  6552  		tt := tt
  6553  		t.Run(tt.name, func(t *testing.T) {
  6554  			exitHandler := make(chan bool, 1)
  6555  			defer close(exitHandler)
  6556  			lastLine := make(chan int, 1)
  6557  
  6558  			sh := HandlerFunc(func(w ResponseWriter, r *Request) {
  6559  				w.WriteHeader(404)
  6560  				w.WriteHeader(404)
  6561  				w.WriteHeader(404)
  6562  				w.WriteHeader(404)
  6563  				_, _, line, _ := runtime.Caller(0)
  6564  				lastLine <- line
  6565  				<-exitHandler
  6566  			})
  6567  
  6568  			if !tt.mustTimeout {
  6569  				exitHandler <- true
  6570  			}
  6571  
  6572  			logBuf := new(strings.Builder)
  6573  			srvLog := log.New(logBuf, "", 0)
  6574  			// When expecting to timeout, we'll keep the duration short.
  6575  			dur := 20 * time.Millisecond
  6576  			if !tt.mustTimeout {
  6577  				// Otherwise, make it arbitrarily long to reduce the risk of flakes.
  6578  				dur = 10 * time.Second
  6579  			}
  6580  			th := TimeoutHandler(sh, dur, timeoutMsg)
  6581  			cst := newClientServerTest(t, mode, th, optWithServerLog(srvLog))
  6582  			defer cst.close()
  6583  
  6584  			res, err := cst.c.Get(cst.ts.URL)
  6585  			if err != nil {
  6586  				t.Fatalf("Unexpected error: %v", err)
  6587  			}
  6588  
  6589  			// Deliberately removing the "Date" header since it is highly ephemeral
  6590  			// and will cause failure if we try to match it exactly.
  6591  			res.Header.Del("Date")
  6592  			res.Header.Del("Content-Type")
  6593  
  6594  			// Match the response.
  6595  			blob, _ := httputil.DumpResponse(res, true)
  6596  			if g, w := string(blob), tt.wantResp; g != w {
  6597  				t.Errorf("Response mismatch\nGot\n%q\n\nWant\n%q", g, w)
  6598  			}
  6599  
  6600  			// Given 4 w.WriteHeader calls, only the first one is valid
  6601  			// and the rest should be reported as the 3 spurious logs.
  6602  			logEntries := strings.Split(strings.TrimSpace(logBuf.String()), "\n")
  6603  			if g, w := len(logEntries), 3; g != w {
  6604  				blob, _ := json.MarshalIndent(logEntries, "", "  ")
  6605  				t.Fatalf("Server logs count mismatch\ngot %d, want %d\n\nGot\n%s\n", g, w, blob)
  6606  			}
  6607  
  6608  			lastSpuriousLine := <-lastLine
  6609  			firstSpuriousLine := lastSpuriousLine - 3
  6610  			// Now ensure that the regexes match exactly.
  6611  			//      "http: superfluous response.WriteHeader call from <fn>.func\d.\d (<curFile>:lastSpuriousLine-[1, 3]"
  6612  			for i, logEntry := range logEntries {
  6613  				wantLine := firstSpuriousLine + i
  6614  				pat := fmt.Sprintf("^http: superfluous response.WriteHeader call from %s.func\\d+.\\d+ \\(%s:%d\\)$",
  6615  					testFuncName, curFileBaseName, wantLine)
  6616  				re := regexp.MustCompile(pat)
  6617  				if !re.MatchString(logEntry) {
  6618  					t.Errorf("Log entry mismatch\n\t%s\ndoes not match\n\t%s", logEntry, pat)
  6619  				}
  6620  			}
  6621  		})
  6622  	}
  6623  }
  6624  
  6625  // fetchWireResponse is a helper for dialing to host,
  6626  // sending http1ReqBody as the payload and retrieving
  6627  // the response as it was sent on the wire.
  6628  func fetchWireResponse(host string, http1ReqBody []byte) ([]byte, error) {
  6629  	conn, err := net.Dial("tcp", host)
  6630  	if err != nil {
  6631  		return nil, err
  6632  	}
  6633  	defer conn.Close()
  6634  
  6635  	if _, err := conn.Write(http1ReqBody); err != nil {
  6636  		return nil, err
  6637  	}
  6638  	return io.ReadAll(conn)
  6639  }
  6640  
  6641  func BenchmarkResponseStatusLine(b *testing.B) {
  6642  	b.ReportAllocs()
  6643  	b.RunParallel(func(pb *testing.PB) {
  6644  		bw := bufio.NewWriter(io.Discard)
  6645  		var buf3 [3]byte
  6646  		for pb.Next() {
  6647  			Export_writeStatusLine(bw, true, 200, buf3[:])
  6648  		}
  6649  	})
  6650  }
  6651  
  6652  func TestDisableKeepAliveUpgrade(t *testing.T) {
  6653  	run(t, testDisableKeepAliveUpgrade, []testMode{http1Mode})
  6654  }
  6655  func testDisableKeepAliveUpgrade(t *testing.T, mode testMode) {
  6656  	if testing.Short() {
  6657  		t.Skip("skipping in short mode")
  6658  	}
  6659  
  6660  	s := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  6661  		w.Header().Set("Connection", "Upgrade")
  6662  		w.Header().Set("Upgrade", "someProto")
  6663  		w.WriteHeader(StatusSwitchingProtocols)
  6664  		c, buf, err := w.(Hijacker).Hijack()
  6665  		if err != nil {
  6666  			return
  6667  		}
  6668  		defer c.Close()
  6669  
  6670  		// Copy from the *bufio.ReadWriter, which may contain buffered data.
  6671  		// Copy to the net.Conn, to avoid buffering the output.
  6672  		io.Copy(c, buf)
  6673  	}), func(ts *httptest.Server) {
  6674  		ts.Config.SetKeepAlivesEnabled(false)
  6675  	}).ts
  6676  
  6677  	cl := s.Client()
  6678  	cl.Transport.(*Transport).DisableKeepAlives = true
  6679  
  6680  	resp, err := cl.Get(s.URL)
  6681  	if err != nil {
  6682  		t.Fatalf("failed to perform request: %v", err)
  6683  	}
  6684  	defer resp.Body.Close()
  6685  
  6686  	if resp.StatusCode != StatusSwitchingProtocols {
  6687  		t.Fatalf("unexpected status code: %v", resp.StatusCode)
  6688  	}
  6689  
  6690  	rwc, ok := resp.Body.(io.ReadWriteCloser)
  6691  	if !ok {
  6692  		t.Fatalf("Response.Body is not an io.ReadWriteCloser: %T", resp.Body)
  6693  	}
  6694  
  6695  	_, err = rwc.Write([]byte("hello"))
  6696  	if err != nil {
  6697  		t.Fatalf("failed to write to body: %v", err)
  6698  	}
  6699  
  6700  	b := make([]byte, 5)
  6701  	_, err = io.ReadFull(rwc, b)
  6702  	if err != nil {
  6703  		t.Fatalf("failed to read from body: %v", err)
  6704  	}
  6705  
  6706  	if string(b) != "hello" {
  6707  		t.Fatalf("unexpected value read from body:\ngot: %q\nwant: %q", b, "hello")
  6708  	}
  6709  }
  6710  
  6711  type tlogWriter struct{ t *testing.T }
  6712  
  6713  func (w tlogWriter) Write(p []byte) (int, error) {
  6714  	w.t.Log(string(p))
  6715  	return len(p), nil
  6716  }
  6717  
  6718  func TestWriteHeaderSwitchingProtocols(t *testing.T) {
  6719  	run(t, testWriteHeaderSwitchingProtocols, []testMode{http1Mode})
  6720  }
  6721  func testWriteHeaderSwitchingProtocols(t *testing.T, mode testMode) {
  6722  	const wantBody = "want"
  6723  	const wantUpgrade = "someProto"
  6724  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  6725  		w.Header().Set("Connection", "Upgrade")
  6726  		w.Header().Set("Upgrade", wantUpgrade)
  6727  		w.WriteHeader(StatusSwitchingProtocols)
  6728  		NewResponseController(w).Flush()
  6729  
  6730  		// Writing headers or the body after sending a 101 header should fail.
  6731  		w.WriteHeader(200)
  6732  		if _, err := w.Write([]byte("x")); err == nil {
  6733  			t.Errorf("Write to body after 101 Switching Protocols unexpectedly succeeded")
  6734  		}
  6735  
  6736  		c, _, err := NewResponseController(w).Hijack()
  6737  		if err != nil {
  6738  			t.Errorf("Hijack: %v", err)
  6739  			return
  6740  		}
  6741  		defer c.Close()
  6742  		if _, err := c.Write([]byte(wantBody)); err != nil {
  6743  			t.Errorf("Write to hijacked body: %v", err)
  6744  		}
  6745  	}), func(ts *httptest.Server) {
  6746  		// Don't spam log with warning about superfluous WriteHeader call.
  6747  		ts.Config.ErrorLog = log.New(tlogWriter{t}, "log: ", 0)
  6748  	}).ts
  6749  
  6750  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  6751  	if err != nil {
  6752  		t.Fatalf("net.Dial: %v", err)
  6753  	}
  6754  	_, err = conn.Write([]byte("GET / HTTP/1.1\r\nHost: foo\r\n\r\n"))
  6755  	if err != nil {
  6756  		t.Fatalf("conn.Write: %v", err)
  6757  	}
  6758  	defer conn.Close()
  6759  
  6760  	r := bufio.NewReader(conn)
  6761  	res, err := ReadResponse(r, &Request{Method: "GET"})
  6762  	if err != nil {
  6763  		t.Fatal("ReadResponse error:", err)
  6764  	}
  6765  	if res.StatusCode != StatusSwitchingProtocols {
  6766  		t.Errorf("Response StatusCode=%v, want 101", res.StatusCode)
  6767  	}
  6768  	if got := res.Header.Get("Upgrade"); got != wantUpgrade {
  6769  		t.Errorf("Response Upgrade header = %q, want %q", got, wantUpgrade)
  6770  	}
  6771  	body, err := io.ReadAll(r)
  6772  	if err != nil {
  6773  		t.Error(err)
  6774  	}
  6775  	if string(body) != wantBody {
  6776  		t.Errorf("Response body = %q, want %q", string(body), wantBody)
  6777  	}
  6778  }
  6779  
  6780  func TestMuxRedirectRelative(t *testing.T) {
  6781  	setParallel(t)
  6782  	req, err := ReadRequest(bufio.NewReader(strings.NewReader("GET http://example.com HTTP/1.1\r\nHost: test\r\n\r\n")))
  6783  	if err != nil {
  6784  		t.Errorf("%s", err)
  6785  	}
  6786  	mux := NewServeMux()
  6787  	resp := httptest.NewRecorder()
  6788  	mux.ServeHTTP(resp, req)
  6789  	if got, want := resp.Header().Get("Location"), "/"; got != want {
  6790  		t.Errorf("Location header expected %q; got %q", want, got)
  6791  	}
  6792  	if got, want := resp.Code, StatusMovedPermanently; got != want {
  6793  		t.Errorf("Expected response code %d; got %d", want, got)
  6794  	}
  6795  }
  6796  
  6797  // TestQuerySemicolon tests the behavior of semicolons in queries. See Issue 25192.
  6798  func TestQuerySemicolon(t *testing.T) {
  6799  	t.Cleanup(func() { afterTest(t) })
  6800  
  6801  	tests := []struct {
  6802  		query              string
  6803  		xNoSemicolons      string
  6804  		xWithSemicolons    string
  6805  		expectParseFormErr bool
  6806  	}{
  6807  		{"?a=1;x=bad&x=good", "good", "bad", true},
  6808  		{"?a=1;b=bad&x=good", "good", "good", true},
  6809  		{"?a=1%3Bx=bad&x=good%3B", "good;", "good;", false},
  6810  		{"?a=1;x=good;x=bad", "", "good", true},
  6811  	}
  6812  
  6813  	run(t, func(t *testing.T, mode testMode) {
  6814  		for _, tt := range tests {
  6815  			t.Run(tt.query+"/allow=false", func(t *testing.T) {
  6816  				allowSemicolons := false
  6817  				testQuerySemicolon(t, mode, tt.query, tt.xNoSemicolons, allowSemicolons, tt.expectParseFormErr)
  6818  			})
  6819  			t.Run(tt.query+"/allow=true", func(t *testing.T) {
  6820  				allowSemicolons, expectParseFormErr := true, false
  6821  				testQuerySemicolon(t, mode, tt.query, tt.xWithSemicolons, allowSemicolons, expectParseFormErr)
  6822  			})
  6823  		}
  6824  	})
  6825  }
  6826  
  6827  func testQuerySemicolon(t *testing.T, mode testMode, query string, wantX string, allowSemicolons, expectParseFormErr bool) {
  6828  	writeBackX := func(w ResponseWriter, r *Request) {
  6829  		x := r.URL.Query().Get("x")
  6830  		if expectParseFormErr {
  6831  			if err := r.ParseForm(); err == nil || !strings.Contains(err.Error(), "semicolon") {
  6832  				t.Errorf("expected error mentioning semicolons from ParseForm, got %v", err)
  6833  			}
  6834  		} else {
  6835  			if err := r.ParseForm(); err != nil {
  6836  				t.Errorf("expected no error from ParseForm, got %v", err)
  6837  			}
  6838  		}
  6839  		if got := r.FormValue("x"); x != got {
  6840  			t.Errorf("got %q from FormValue, want %q", got, x)
  6841  		}
  6842  		fmt.Fprintf(w, "%s", x)
  6843  	}
  6844  
  6845  	h := Handler(HandlerFunc(writeBackX))
  6846  	if allowSemicolons {
  6847  		h = AllowQuerySemicolons(h)
  6848  	}
  6849  
  6850  	logBuf := &strings.Builder{}
  6851  	ts := newClientServerTest(t, mode, h, func(ts *httptest.Server) {
  6852  		ts.Config.ErrorLog = log.New(logBuf, "", 0)
  6853  	}).ts
  6854  
  6855  	req, _ := NewRequest("GET", ts.URL+query, nil)
  6856  	res, err := ts.Client().Do(req)
  6857  	if err != nil {
  6858  		t.Fatal(err)
  6859  	}
  6860  	slurp, _ := io.ReadAll(res.Body)
  6861  	res.Body.Close()
  6862  	if got, want := res.StatusCode, 200; got != want {
  6863  		t.Errorf("Status = %d; want = %d", got, want)
  6864  	}
  6865  	if got, want := string(slurp), wantX; got != want {
  6866  		t.Errorf("Body = %q; want = %q", got, want)
  6867  	}
  6868  }
  6869  
  6870  func TestMaxBytesHandler(t *testing.T) {
  6871  	// Not parallel: modifies the global rstAvoidanceDelay.
  6872  	defer afterTest(t)
  6873  
  6874  	for _, maxSize := range []int64{100, 1_000, 1_000_000} {
  6875  		for _, requestSize := range []int64{100, 1_000, 1_000_000} {
  6876  			t.Run(fmt.Sprintf("max size %d request size %d", maxSize, requestSize),
  6877  				func(t *testing.T) {
  6878  					run(t, func(t *testing.T, mode testMode) {
  6879  						testMaxBytesHandler(t, mode, maxSize, requestSize)
  6880  					}, testNotParallel)
  6881  				})
  6882  		}
  6883  	}
  6884  }
  6885  
  6886  func testMaxBytesHandler(t *testing.T, mode testMode, maxSize, requestSize int64) {
  6887  	runTimeSensitiveTest(t, []time.Duration{
  6888  		1 * time.Millisecond,
  6889  		5 * time.Millisecond,
  6890  		10 * time.Millisecond,
  6891  		50 * time.Millisecond,
  6892  		100 * time.Millisecond,
  6893  		500 * time.Millisecond,
  6894  		time.Second,
  6895  		5 * time.Second,
  6896  	}, func(t *testing.T, timeout time.Duration) error {
  6897  		SetRSTAvoidanceDelay(t, timeout)
  6898  		t.Logf("set RST avoidance delay to %v", timeout)
  6899  
  6900  		var (
  6901  			handlerN   int64
  6902  			handlerErr error
  6903  		)
  6904  		echo := HandlerFunc(func(w ResponseWriter, r *Request) {
  6905  			var buf bytes.Buffer
  6906  			handlerN, handlerErr = io.Copy(&buf, r.Body)
  6907  			io.Copy(w, &buf)
  6908  		})
  6909  
  6910  		cst := newClientServerTest(t, mode, MaxBytesHandler(echo, maxSize))
  6911  		// We need to close cst explicitly here so that in-flight server
  6912  		// requests don't race with the call to SetRSTAvoidanceDelay for a retry.
  6913  		defer cst.close()
  6914  		ts := cst.ts
  6915  		c := ts.Client()
  6916  
  6917  		body := strings.Repeat("a", int(requestSize))
  6918  		var wg sync.WaitGroup
  6919  		defer wg.Wait()
  6920  		getBody := func() (io.ReadCloser, error) {
  6921  			wg.Add(1)
  6922  			body := &wgReadCloser{
  6923  				Reader: strings.NewReader(body),
  6924  				wg:     &wg,
  6925  			}
  6926  			return body, nil
  6927  		}
  6928  		reqBody, _ := getBody()
  6929  		req, err := NewRequest("POST", ts.URL, reqBody)
  6930  		if err != nil {
  6931  			reqBody.Close()
  6932  			t.Fatal(err)
  6933  		}
  6934  		req.ContentLength = int64(len(body))
  6935  		req.GetBody = getBody
  6936  		req.Header.Set("Content-Type", "text/plain")
  6937  
  6938  		var buf strings.Builder
  6939  		res, err := c.Do(req)
  6940  		if err != nil {
  6941  			return fmt.Errorf("unexpected connection error: %v", err)
  6942  		} else {
  6943  			_, err = io.Copy(&buf, res.Body)
  6944  			res.Body.Close()
  6945  			if err != nil {
  6946  				return fmt.Errorf("unexpected read error: %v", err)
  6947  			}
  6948  		}
  6949  		// We don't expect any of the errors after this point to occur due
  6950  		// to rstAvoidanceDelay being too short, so we use t.Errorf for those
  6951  		// instead of returning a (retriable) error.
  6952  
  6953  		if handlerN > maxSize {
  6954  			t.Errorf("expected max request body %d; got %d", maxSize, handlerN)
  6955  		}
  6956  		if requestSize > maxSize && handlerErr == nil {
  6957  			t.Error("expected error on handler side; got nil")
  6958  		}
  6959  		if requestSize <= maxSize {
  6960  			if handlerErr != nil {
  6961  				t.Errorf("%d expected nil error on handler side; got %v", requestSize, handlerErr)
  6962  			}
  6963  			if handlerN != requestSize {
  6964  				t.Errorf("expected request of size %d; got %d", requestSize, handlerN)
  6965  			}
  6966  		}
  6967  		if buf.Len() != int(handlerN) {
  6968  			t.Errorf("expected echo of size %d; got %d", handlerN, buf.Len())
  6969  		}
  6970  
  6971  		return nil
  6972  	})
  6973  }
  6974  
  6975  func TestEarlyHints(t *testing.T) {
  6976  	ht := newHandlerTest(HandlerFunc(func(w ResponseWriter, r *Request) {
  6977  		h := w.Header()
  6978  		h.Add("Link", "</style.css>; rel=preload; as=style")
  6979  		h.Add("Link", "</script.js>; rel=preload; as=script")
  6980  		w.WriteHeader(StatusEarlyHints)
  6981  
  6982  		h.Add("Link", "</foo.js>; rel=preload; as=script")
  6983  		w.WriteHeader(StatusEarlyHints)
  6984  
  6985  		w.Write([]byte("stuff"))
  6986  	}))
  6987  
  6988  	got := ht.rawResponse("GET / HTTP/1.1\nHost: golang.org")
  6989  	expected := "HTTP/1.1 103 Early Hints\r\nLink: </style.css>; rel=preload; as=style\r\nLink: </script.js>; rel=preload; as=script\r\n\r\nHTTP/1.1 103 Early Hints\r\nLink: </style.css>; rel=preload; as=style\r\nLink: </script.js>; rel=preload; as=script\r\nLink: </foo.js>; rel=preload; as=script\r\n\r\nHTTP/1.1 200 OK\r\nLink: </style.css>; rel=preload; as=style\r\nLink: </script.js>; rel=preload; as=script\r\nLink: </foo.js>; rel=preload; as=script\r\nDate: " // dynamic content expected
  6990  	if !strings.Contains(got, expected) {
  6991  		t.Errorf("unexpected response; got %q; should start by %q", got, expected)
  6992  	}
  6993  }
  6994  func TestProcessing(t *testing.T) {
  6995  	ht := newHandlerTest(HandlerFunc(func(w ResponseWriter, r *Request) {
  6996  		w.WriteHeader(StatusProcessing)
  6997  		w.Write([]byte("stuff"))
  6998  	}))
  6999  
  7000  	got := ht.rawResponse("GET / HTTP/1.1\nHost: golang.org")
  7001  	expected := "HTTP/1.1 102 Processing\r\n\r\nHTTP/1.1 200 OK\r\nDate: " // dynamic content expected
  7002  	if !strings.Contains(got, expected) {
  7003  		t.Errorf("unexpected response; got %q; should start by %q", got, expected)
  7004  	}
  7005  }
  7006  
  7007  func TestParseFormCleanup(t *testing.T) { run(t, testParseFormCleanup) }
  7008  func testParseFormCleanup(t *testing.T, mode testMode) {
  7009  	if mode == http2Mode {
  7010  		t.Skip("https://go.dev/issue/20253")
  7011  	}
  7012  
  7013  	const maxMemory = 1024
  7014  	const key = "file"
  7015  
  7016  	if runtime.GOOS == "windows" {
  7017  		// Windows sometimes refuses to remove a file that was just closed.
  7018  		t.Skip("https://go.dev/issue/25965")
  7019  	}
  7020  
  7021  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  7022  		r.ParseMultipartForm(maxMemory)
  7023  		f, _, err := r.FormFile(key)
  7024  		if err != nil {
  7025  			t.Errorf("r.FormFile(%q) = %v", key, err)
  7026  			return
  7027  		}
  7028  		of, ok := f.(*os.File)
  7029  		if !ok {
  7030  			t.Errorf("r.FormFile(%q) returned type %T, want *os.File", key, f)
  7031  			return
  7032  		}
  7033  		w.Write([]byte(of.Name()))
  7034  	}))
  7035  
  7036  	fBuf := new(bytes.Buffer)
  7037  	mw := multipart.NewWriter(fBuf)
  7038  	mf, err := mw.CreateFormFile(key, "myfile.txt")
  7039  	if err != nil {
  7040  		t.Fatal(err)
  7041  	}
  7042  	if _, err := mf.Write(bytes.Repeat([]byte("A"), maxMemory*2)); err != nil {
  7043  		t.Fatal(err)
  7044  	}
  7045  	if err := mw.Close(); err != nil {
  7046  		t.Fatal(err)
  7047  	}
  7048  	req, err := NewRequest("POST", cst.ts.URL, fBuf)
  7049  	if err != nil {
  7050  		t.Fatal(err)
  7051  	}
  7052  	req.Header.Set("Content-Type", mw.FormDataContentType())
  7053  	res, err := cst.c.Do(req)
  7054  	if err != nil {
  7055  		t.Fatal(err)
  7056  	}
  7057  	defer res.Body.Close()
  7058  	fname, err := io.ReadAll(res.Body)
  7059  	if err != nil {
  7060  		t.Fatal(err)
  7061  	}
  7062  	cst.close()
  7063  	if _, err := os.Stat(string(fname)); !errors.Is(err, os.ErrNotExist) {
  7064  		t.Errorf("file %q exists after HTTP handler returned", string(fname))
  7065  	}
  7066  }
  7067  
  7068  func TestHeadBody(t *testing.T) {
  7069  	const identityMode = false
  7070  	const chunkedMode = true
  7071  	run(t, func(t *testing.T, mode testMode) {
  7072  		t.Run("identity", func(t *testing.T) { testHeadBody(t, mode, identityMode, "HEAD") })
  7073  		t.Run("chunked", func(t *testing.T) { testHeadBody(t, mode, chunkedMode, "HEAD") })
  7074  	})
  7075  }
  7076  
  7077  func TestGetBody(t *testing.T) {
  7078  	const identityMode = false
  7079  	const chunkedMode = true
  7080  	run(t, func(t *testing.T, mode testMode) {
  7081  		t.Run("identity", func(t *testing.T) { testHeadBody(t, mode, identityMode, "GET") })
  7082  		t.Run("chunked", func(t *testing.T) { testHeadBody(t, mode, chunkedMode, "GET") })
  7083  	})
  7084  }
  7085  
  7086  func testHeadBody(t *testing.T, mode testMode, chunked bool, method string) {
  7087  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  7088  		b, err := io.ReadAll(r.Body)
  7089  		if err != nil {
  7090  			t.Errorf("server reading body: %v", err)
  7091  			return
  7092  		}
  7093  		w.Header().Set("X-Request-Body", string(b))
  7094  		w.Header().Set("Content-Length", "0")
  7095  	}))
  7096  	defer cst.close()
  7097  	for _, reqBody := range []string{
  7098  		"",
  7099  		"",
  7100  		"request_body",
  7101  		"",
  7102  	} {
  7103  		var bodyReader io.Reader
  7104  		if reqBody != "" {
  7105  			bodyReader = strings.NewReader(reqBody)
  7106  			if chunked {
  7107  				bodyReader = bufio.NewReader(bodyReader)
  7108  			}
  7109  		}
  7110  		req, err := NewRequest(method, cst.ts.URL, bodyReader)
  7111  		if err != nil {
  7112  			t.Fatal(err)
  7113  		}
  7114  		res, err := cst.c.Do(req)
  7115  		if err != nil {
  7116  			t.Fatal(err)
  7117  		}
  7118  		res.Body.Close()
  7119  		if got, want := res.StatusCode, 200; got != want {
  7120  			t.Errorf("%v request with %d-byte body: StatusCode = %v, want %v", method, len(reqBody), got, want)
  7121  		}
  7122  		if got, want := res.Header.Get("X-Request-Body"), reqBody; got != want {
  7123  			t.Errorf("%v request with %d-byte body: handler read body %q, want %q", method, len(reqBody), got, want)
  7124  		}
  7125  	}
  7126  }
  7127  
  7128  // TestDisableContentLength verifies that the Content-Length is set by default
  7129  // or disabled when the header is set to nil.
  7130  func TestDisableContentLength(t *testing.T) { run(t, testDisableContentLength) }
  7131  func testDisableContentLength(t *testing.T, mode testMode) {
  7132  	noCL := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  7133  		w.Header()["Content-Length"] = nil // disable the default Content-Length response
  7134  		fmt.Fprintf(w, "OK")
  7135  	}))
  7136  
  7137  	res, err := noCL.c.Get(noCL.ts.URL)
  7138  	if err != nil {
  7139  		t.Fatal(err)
  7140  	}
  7141  	if got, haveCL := res.Header["Content-Length"]; haveCL {
  7142  		t.Errorf("Unexpected Content-Length: %q", got)
  7143  	}
  7144  	if err := res.Body.Close(); err != nil {
  7145  		t.Fatal(err)
  7146  	}
  7147  
  7148  	withCL := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  7149  		fmt.Fprintf(w, "OK")
  7150  	}))
  7151  
  7152  	res, err = withCL.c.Get(withCL.ts.URL)
  7153  	if err != nil {
  7154  		t.Fatal(err)
  7155  	}
  7156  	if got := res.Header.Get("Content-Length"); got != "2" {
  7157  		t.Errorf("Content-Length: %q; want 2", got)
  7158  	}
  7159  	if err := res.Body.Close(); err != nil {
  7160  		t.Fatal(err)
  7161  	}
  7162  }
  7163  
  7164  func TestErrorContentLength(t *testing.T) { run(t, testErrorContentLength) }
  7165  func testErrorContentLength(t *testing.T, mode testMode) {
  7166  	const errorBody = "an error occurred"
  7167  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  7168  		w.Header().Set("Content-Length", "1000")
  7169  		Error(w, errorBody, 400)
  7170  	}))
  7171  	res, err := cst.c.Get(cst.ts.URL)
  7172  	if err != nil {
  7173  		t.Fatalf("Get(%q) = %v", cst.ts.URL, err)
  7174  	}
  7175  	defer res.Body.Close()
  7176  	body, err := io.ReadAll(res.Body)
  7177  	if err != nil {
  7178  		t.Fatalf("io.ReadAll(res.Body) = %v", err)
  7179  	}
  7180  	if string(body) != errorBody+"\n" {
  7181  		t.Fatalf("read body: %q, want %q", string(body), errorBody)
  7182  	}
  7183  }
  7184  
  7185  func TestError(t *testing.T) {
  7186  	w := httptest.NewRecorder()
  7187  	w.Header().Set("Content-Length", "1")
  7188  	w.Header().Set("X-Content-Type-Options", "scratch and sniff")
  7189  	w.Header().Set("Other", "foo")
  7190  	Error(w, "oops", 432)
  7191  
  7192  	h := w.Header()
  7193  	for _, hdr := range []string{"Content-Length"} {
  7194  		if v, ok := h[hdr]; ok {
  7195  			t.Errorf("%s: %q, want not present", hdr, v)
  7196  		}
  7197  	}
  7198  	if v := h.Get("Content-Type"); v != "text/plain; charset=utf-8" {
  7199  		t.Errorf("Content-Type: %q, want %q", v, "text/plain; charset=utf-8")
  7200  	}
  7201  	if v := h.Get("X-Content-Type-Options"); v != "nosniff" {
  7202  		t.Errorf("X-Content-Type-Options: %q, want %q", v, "nosniff")
  7203  	}
  7204  }
  7205  
  7206  func TestServerReadAfterWriteHeader100Continue(t *testing.T) {
  7207  	run(t, testServerReadAfterWriteHeader100Continue)
  7208  }
  7209  func testServerReadAfterWriteHeader100Continue(t *testing.T, mode testMode) {
  7210  	t.Skip("https://go.dev/issue/67555")
  7211  	body := []byte("body")
  7212  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  7213  		w.WriteHeader(200)
  7214  		NewResponseController(w).Flush()
  7215  		io.ReadAll(r.Body)
  7216  		w.Write(body)
  7217  	}), func(tr *Transport) {
  7218  		tr.ExpectContinueTimeout = 24 * time.Hour // forever
  7219  	})
  7220  
  7221  	req, _ := NewRequest("GET", cst.ts.URL, strings.NewReader("body"))
  7222  	req.Header.Set("Expect", "100-continue")
  7223  	res, err := cst.c.Do(req)
  7224  	if err != nil {
  7225  		t.Fatalf("Get(%q) = %v", cst.ts.URL, err)
  7226  	}
  7227  	defer res.Body.Close()
  7228  	got, err := io.ReadAll(res.Body)
  7229  	if err != nil {
  7230  		t.Fatalf("io.ReadAll(res.Body) = %v", err)
  7231  	}
  7232  	if !bytes.Equal(got, body) {
  7233  		t.Fatalf("response body = %q, want %q", got, body)
  7234  	}
  7235  }
  7236  
  7237  func TestServerReadAfterHandlerDone100Continue(t *testing.T) {
  7238  	run(t, testServerReadAfterHandlerDone100Continue)
  7239  }
  7240  func testServerReadAfterHandlerDone100Continue(t *testing.T, mode testMode) {
  7241  	t.Skip("https://go.dev/issue/67555")
  7242  	readyc := make(chan struct{})
  7243  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  7244  		go func() {
  7245  			<-readyc
  7246  			io.ReadAll(r.Body)
  7247  			<-readyc
  7248  		}()
  7249  	}), func(tr *Transport) {
  7250  		tr.ExpectContinueTimeout = 24 * time.Hour // forever
  7251  	})
  7252  
  7253  	req, _ := NewRequest("GET", cst.ts.URL, strings.NewReader("body"))
  7254  	req.Header.Set("Expect", "100-continue")
  7255  	res, err := cst.c.Do(req)
  7256  	if err != nil {
  7257  		t.Fatalf("Get(%q) = %v", cst.ts.URL, err)
  7258  	}
  7259  	res.Body.Close()
  7260  	readyc <- struct{}{} // server starts reading from the request body
  7261  	readyc <- struct{}{} // server finishes reading from the request body
  7262  }
  7263  
  7264  func TestServerReadAfterHandlerAbort100Continue(t *testing.T) {
  7265  	run(t, testServerReadAfterHandlerAbort100Continue)
  7266  }
  7267  func testServerReadAfterHandlerAbort100Continue(t *testing.T, mode testMode) {
  7268  	t.Skip("https://go.dev/issue/67555")
  7269  	readyc := make(chan struct{})
  7270  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  7271  		go func() {
  7272  			<-readyc
  7273  			io.ReadAll(r.Body)
  7274  			<-readyc
  7275  		}()
  7276  		panic(ErrAbortHandler)
  7277  	}), func(tr *Transport) {
  7278  		tr.ExpectContinueTimeout = 24 * time.Hour // forever
  7279  	})
  7280  
  7281  	req, _ := NewRequest("GET", cst.ts.URL, strings.NewReader("body"))
  7282  	req.Header.Set("Expect", "100-continue")
  7283  	res, err := cst.c.Do(req)
  7284  	if err == nil {
  7285  		res.Body.Close()
  7286  	}
  7287  	readyc <- struct{}{} // server starts reading from the request body
  7288  	readyc <- struct{}{} // server finishes reading from the request body
  7289  }
  7290  
  7291  func TestInvalidChunkedBodies(t *testing.T) {
  7292  	for _, test := range []struct {
  7293  		name string
  7294  		b    string
  7295  	}{{
  7296  		name: "bare LF in chunk size",
  7297  		b:    "1\na\r\n0\r\n\r\n",
  7298  	}, {
  7299  		name: "bare LF at body end",
  7300  		b:    "1\r\na\r\n0\r\n\n",
  7301  	}} {
  7302  		t.Run(test.name, func(t *testing.T) {
  7303  			reqc := make(chan error)
  7304  			ts := newClientServerTest(t, http1Mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  7305  				got, err := io.ReadAll(r.Body)
  7306  				if err == nil {
  7307  					t.Logf("read body: %q", got)
  7308  				}
  7309  				reqc <- err
  7310  			})).ts
  7311  
  7312  			serverURL, err := url.Parse(ts.URL)
  7313  			if err != nil {
  7314  				t.Fatal(err)
  7315  			}
  7316  
  7317  			conn, err := net.Dial("tcp", serverURL.Host)
  7318  			if err != nil {
  7319  				t.Fatal(err)
  7320  			}
  7321  
  7322  			if _, err := conn.Write([]byte(
  7323  				"POST / HTTP/1.1\r\n" +
  7324  					"Host: localhost\r\n" +
  7325  					"Transfer-Encoding: chunked\r\n" +
  7326  					"Connection: close\r\n" +
  7327  					"\r\n" +
  7328  					test.b)); err != nil {
  7329  				t.Fatal(err)
  7330  			}
  7331  			conn.(*net.TCPConn).CloseWrite()
  7332  
  7333  			if err := <-reqc; err == nil {
  7334  				t.Errorf("server handler: io.ReadAll(r.Body) succeeded, want error")
  7335  			}
  7336  		})
  7337  	}
  7338  }
  7339  
  7340  // Issue #72100: Verify that we don't modify the caller's TLS.Config.NextProtos slice.
  7341  func TestServerTLSNextProtos(t *testing.T) {
  7342  	run(t, testServerTLSNextProtos, []testMode{https1Mode, http2Mode})
  7343  }
  7344  func testServerTLSNextProtos(t *testing.T, mode testMode) {
  7345  	CondSkipHTTP2(t)
  7346  
  7347  	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
  7348  	if err != nil {
  7349  		t.Fatal(err)
  7350  	}
  7351  	leafCert, err := x509.ParseCertificate(cert.Certificate[0])
  7352  	if err != nil {
  7353  		t.Fatal(err)
  7354  	}
  7355  	certpool := x509.NewCertPool()
  7356  	certpool.AddCert(leafCert)
  7357  
  7358  	protos := new(Protocols)
  7359  	switch mode {
  7360  	case https1Mode:
  7361  		protos.SetHTTP1(true)
  7362  	case http2Mode:
  7363  		protos.SetHTTP2(true)
  7364  	}
  7365  
  7366  	wantNextProtos := []string{"http/1.1", "h2", "other"}
  7367  	nextProtos := slices.Clone(wantNextProtos)
  7368  
  7369  	// We don't use httptest here because it overrides the tls.Config.
  7370  	srv := &Server{
  7371  		TLSConfig: &tls.Config{
  7372  			Certificates: []tls.Certificate{cert},
  7373  			NextProtos:   nextProtos,
  7374  		},
  7375  		Handler:   HandlerFunc(func(w ResponseWriter, req *Request) {}),
  7376  		Protocols: protos,
  7377  	}
  7378  	tr := &Transport{
  7379  		TLSClientConfig: &tls.Config{
  7380  			RootCAs:    certpool,
  7381  			NextProtos: nextProtos,
  7382  		},
  7383  		Protocols: protos,
  7384  	}
  7385  
  7386  	listener := newLocalListener(t)
  7387  	srvc := make(chan error, 1)
  7388  	go func() {
  7389  		srvc <- srv.ServeTLS(listener, "", "")
  7390  	}()
  7391  	t.Cleanup(func() {
  7392  		srv.Close()
  7393  		<-srvc
  7394  	})
  7395  
  7396  	client := &Client{Transport: tr}
  7397  	resp, err := client.Get("https://" + listener.Addr().String())
  7398  	if err != nil {
  7399  		t.Fatal(err)
  7400  	}
  7401  	resp.Body.Close()
  7402  
  7403  	if !slices.Equal(nextProtos, wantNextProtos) {
  7404  		t.Fatalf("after running test: original NextProtos slice = %v, want %v", nextProtos, wantNextProtos)
  7405  	}
  7406  }
  7407