support h2c with prior knowledge

gin.go

@@ -5,13 +5,17 @@
 package gin
 
 import (
+	"fmt"
 	"html/template"
+	"io"
 	"net"
 	"net/http"
 	"os"
+	"strings"
 	"sync"
 
 	"github.com/gin-gonic/gin/render"
+	"golang.org/x/net/http2"
 )
 
 const (
@@ -103,6 +107,7 @@ type Engine struct {
 	noMethod         HandlersChain
 	pool             sync.Pool
 	trees            methodTrees
+	h2Server         *http2.Server
 }
 
 var _ IRouter = &Engine{}
@@ -282,6 +287,9 @@ func iterate(path, method string, routes RoutesInfo, root *node) RoutesInfo {
 func (engine *Engine) Run(addr ...string) (err error) {
 	defer func() { debugPrintError(err) }()
 
+	// TODO support h2Server configuration
+	engine.h2Server = &http2.Server{}
+
 	address := resolveAddress(addr)
 	debugPrint("Listening and serving HTTP on %s\n", address)
 	err = http.ListenAndServe(address, engine)
@@ -318,6 +326,10 @@ func (engine *Engine) RunUnix(file string) (err error) {
 
 // ServeHTTP conforms to the http.Handler interface.
 func (engine *Engine) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	if engine.tryHandleH2C(w, req) {
+		return
+	}
+
 	c := engine.pool.Get().(*Context)
 	c.writermem.reset(w)
 	c.Request = req
@@ -328,6 +340,44 @@ func (engine *Engine) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	engine.pool.Put(c)
 }
 
+func (engine *Engine) tryHandleH2C(w http.ResponseWriter, req *http.Request) bool {
+	if req.Method != "PRI" || req.URL.Path != "*" || req.ProtoMajor < 2 {
+		return false
+	}
+
+	hijacker, ok := w.(http.Hijacker)
+	if !ok {
+		return false
+	}
+
+	conn, rw, err := hijacker.Hijack()
+	if err != nil {
+		return false
+	}
+
+	const expectedBody = "SM\r\n\r\n"
+	buf := make([]byte, len(expectedBody))
+	n, err := io.ReadFull(rw, buf)
+
+	if err != nil {
+		panic(fmt.Sprintf("Error h2c with prior knowledge: %v", err))
+	}
+
+	if string(buf[:n]) != expectedBody {
+		return false
+	}
+
+	conn2 := &rwConn{
+		Conn:      conn,
+		Reader:    io.MultiReader(strings.NewReader(http2.ClientPreface), rw),
+		BufWriter: rw.Writer,
+	}
+
+	engine.h2Server.ServeConn(conn2, &http2.ServeConnOpts{Handler: engine})
+
+	return true
+}
+
 // HandleContext re-enter a context that has been rewritten.
 // This can be done by setting c.Request.URL.Path to your new target.
 // Disclaimer: You can loop yourself to death with this, use wisely.

gin_test.go

@@ -9,12 +9,14 @@ import (
 	"fmt"
 	"html/template"
 	"io/ioutil"
+	"net"
 	"net/http"
 	"reflect"
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"golang.org/x/net/http2"
 )
 
 func formatAsDate(t time.Time) string {
@@ -93,6 +95,29 @@ func TestLoadHTMLGlob(t *testing.T) {
 	td()
 }
 
+func TestLoadHTMLGlobOverH2c(t *testing.T) {
+	td := setupHTMLGlob(t, DebugMode, false)
+
+	http := http.Client{
+		Transport: &http2.Transport{
+			AllowHTTP: true,
+			DialTLS: func(netw, addr string, cfg *tls.Config) (net.Conn, error) {
+				return net.Dial(netw, addr)
+			},
+		},
+	}
+
+	res, err := http.Get("http://127.0.0.1:8888/test")
+	if err != nil {
+		fmt.Println(err)
+	}
+
+	resp, _ := ioutil.ReadAll(res.Body)
+	assert.Equal(t, "<h1>Hello world</h1>", string(resp[:]))
+
+	td()
+}
+
 func TestLoadHTMLGlob2(t *testing.T) {
 	td := setupHTMLGlob(t, TestMode, false)
 	res, err := http.Get("http://127.0.0.1:8888/test")

h2c.go

@@ -0,0 +1,37 @@
+// Copyright 2014 Manu Martinez-Almeida.  All rights reserved.
+// Use of this source code is governed by a MIT style
+// license that can be found in the LICENSE file.
+
+package gin
+
+import (
+	"io"
+	"net"
+)
+
+type bufWriter interface {
+	io.Writer
+	Flush() error
+}
+
+// rwConn implements net.Conn but overrides Read and Write so that reads and
+// writes are forwarded to the provided io.Reader and bufWriter.
+type rwConn struct {
+	net.Conn
+	io.Reader
+	BufWriter bufWriter
+}
+
+// Read forwards reads to the underlying Reader.
+func (c *rwConn) Read(p []byte) (int, error) {
+	return c.Reader.Read(p)
+}
+
+// Write forwards writes to the underlying bufWriter and immediately flushes.
+func (c *rwConn) Write(p []byte) (int, error) {
+	n, err := c.BufWriter.Write(p)
+	if err := c.BufWriter.Flush(); err != nil {
+		return 0, err
+	}
+	return n, err
+}

vendor/vendor.json

@@ -102,6 +102,30 @@
 			"revision": "d4c55e66d8c3a2f3382d264b08e3e3454a66355a",
 			"revisionTime": "2016-10-18T08:54:36Z"
 		},
+		{
+			"checksumSHA1": "pCY4YtdNKVBYRbNvODjx8hj0hIs=",
+			"path": "golang.org/x/net/http/httpguts",
+			"revision": "db08ff08e8622530d9ed3a0e8ac279f6d4c02196",
+			"revisionTime": "2018-06-11T16:35:41Z"
+		},
+		{
+			"checksumSHA1": "NNo0AcF8P5+b/140t0Wox/HFkkw=",
+			"path": "golang.org/x/net/http2",
+			"revision": "db08ff08e8622530d9ed3a0e8ac279f6d4c02196",
+			"revisionTime": "2018-06-11T16:35:41Z"
+		},
+		{
+			"checksumSHA1": "leSW9aM30mATlWs/eeqhQQh/3eo=",
+			"path": "golang.org/x/net/http2/hpack",
+			"revision": "db08ff08e8622530d9ed3a0e8ac279f6d4c02196",
+			"revisionTime": "2018-06-11T16:35:41Z"
+		},
+		{
+			"checksumSHA1": "RcrB7tgYS/GMW4QrwVdMOTNqIU8=",
+			"path": "golang.org/x/net/idna",
+			"revision": "db08ff08e8622530d9ed3a0e8ac279f6d4c02196",
+			"revisionTime": "2018-06-11T16:35:41Z"
+		},
 		{
 			"checksumSHA1": "S0DP7Pn7sZUmXc55IzZnNvERu6s=",
 			"path": "golang.org/x/sync/errgroup",
@@ -114,6 +138,30 @@
 			"revision": "99f16d856c9836c42d24e7ab64ea72916925fa97",
 			"revisionTime": "2017-03-08T15:04:45Z"
 		},
+		{
+			"checksumSHA1": "CbpjEkkOeh0fdM/V8xKDdI0AA88=",
+			"path": "golang.org/x/text/secure/bidirule",
+			"revision": "5cec4b58c438bd98288aeb248bab2c1840713d21",
+			"revisionTime": "2018-05-20T16:02:21Z"
+		},
+		{
+			"checksumSHA1": "ziMb9+ANGRJSSIuxYdRbA+cDRBQ=",
+			"path": "golang.org/x/text/transform",
+			"revision": "5cec4b58c438bd98288aeb248bab2c1840713d21",
+			"revisionTime": "2018-05-20T16:02:21Z"
+		},
+		{
+			"checksumSHA1": "1oQpUH9BjCWlqFPDahRH+UMlYy4=",
+			"path": "golang.org/x/text/unicode/bidi",
+			"revision": "5cec4b58c438bd98288aeb248bab2c1840713d21",
+			"revisionTime": "2018-05-20T16:02:21Z"
+		},
+		{
+			"checksumSHA1": "lN2xlA6Utu7tXy2iUoMF2+y9EUE=",
+			"path": "golang.org/x/text/unicode/norm",
+			"revision": "5cec4b58c438bd98288aeb248bab2c1840713d21",
+			"revisionTime": "2018-05-20T16:02:21Z"
+		},
 		{
 			"checksumSHA1": "39V1idWER42Lmcmg2Uy40wMzOlo=",
 			"comment": "v8.18.1",