From 5046e734107e808cc69375505ed868abc624605e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=B6=9B=E5=8F=94?= <hi@taoshu.in>
Date: Sat, 5 Feb 2022 21:13:20 +0800
Subject: [PATCH] Add h2c support (#1398)

---
 gin.go      | 22 ++++++++++++++++++----
 gin_test.go | 34 ++++++++++++++++++++++++++++++++++
 go.mod      |  1 +
 go.sum      |  1 +
 4 files changed, 54 insertions(+), 4 deletions(-)

diff --git a/gin.go b/gin.go
index 9bd4c46af6..b54dbd8a62 100644
--- a/gin.go
+++ b/gin.go
@@ -16,6 +16,8 @@ import (
 
 	"github.com/gin-gonic/gin/internal/bytesconv"
 	"github.com/gin-gonic/gin/render"
+	"golang.org/x/net/http2"
+	"golang.org/x/net/http2/h2c"
 )
 
 const defaultMultipartMemory = 32 << 20 // 32 MB
@@ -141,6 +143,9 @@ type Engine struct {
 	// method call.
 	MaxMultipartMemory int64
 
+	// Enable h2c support.
+	UseH2C bool
+
 	delims           render.Delims
 	secureJSONPrefix string
 	HTMLRender       render.HTMLRender
@@ -207,6 +212,15 @@ func Default() *Engine {
 	return engine
 }
 
+func (engine *Engine) Handler() http.Handler {
+	if !engine.UseH2C {
+		return engine
+	}
+
+	h2s := &http2.Server{}
+	return h2c.NewHandler(engine, h2s)
+}
+
 func (engine *Engine) allocateContext() *Context {
 	v := make(Params, 0, engine.maxParams)
 	skippedNodes := make([]skippedNode, 0, engine.maxSections)
@@ -361,7 +375,7 @@ func (engine *Engine) Run(addr ...string) (err error) {
 
 	address := resolveAddress(addr)
 	debugPrint("Listening and serving HTTP on %s\n", address)
-	err = http.ListenAndServe(address, engine)
+	err = http.ListenAndServe(address, engine.Handler())
 	return
 }
 
@@ -480,7 +494,7 @@ func (engine *Engine) RunTLS(addr, certFile, keyFile string) (err error) {
 			"Please check https://pkg.go.dev/github.com/gin-gonic/gin#readme-don-t-trust-all-proxies for details.")
 	}
 
-	err = http.ListenAndServeTLS(addr, certFile, keyFile, engine)
+	err = http.ListenAndServeTLS(addr, certFile, keyFile, engine.Handler())
 	return
 }
 
@@ -503,7 +517,7 @@ func (engine *Engine) RunUnix(file string) (err error) {
 	defer listener.Close()
 	defer os.Remove(file)
 
-	err = http.Serve(listener, engine)
+	err = http.Serve(listener, engine.Handler())
 	return
 }
 
@@ -540,7 +554,7 @@ func (engine *Engine) RunListener(listener net.Listener) (err error) {
 			"Please check https://pkg.go.dev/github.com/gin-gonic/gin#readme-don-t-trust-all-proxies for details.")
 	}
 
-	err = http.Serve(listener, engine)
+	err = http.Serve(listener, engine.Handler())
 	return
 }
 
diff --git a/gin_test.go b/gin_test.go
index 0aece61d16..629a109b2d 100644
--- a/gin_test.go
+++ b/gin_test.go
@@ -19,6 +19,7 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"golang.org/x/net/http2"
 )
 
 func formatAsDate(t time.Time) string {
@@ -79,6 +80,39 @@ func TestLoadHTMLGlobDebugMode(t *testing.T) {
 	assert.Equal(t, "<h1>Hello world</h1>", string(resp))
 }
 
+func TestH2c(t *testing.T) {
+	ln, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		fmt.Println(err)
+	}
+	r := Default()
+	r.UseH2C = true
+	r.GET("/", func(c *Context) {
+		c.String(200, "<h1>Hello world</h1>")
+	})
+	go http.Serve(ln, r.Handler())
+	defer ln.Close()
+
+	url := "http://" + ln.Addr().String() + "/"
+
+	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(url)
+	if err != nil {
+		fmt.Println(err)
+	}
+
+	resp, _ := ioutil.ReadAll(res.Body)
+	assert.Equal(t, "<h1>Hello world</h1>", string(resp))
+}
+
 func TestLoadHTMLGlobTestMode(t *testing.T) {
 	ts := setupHTMLFiles(
 		t,
diff --git a/go.mod b/go.mod
index b088f26bb9..b59e590728 100644
--- a/go.mod
+++ b/go.mod
@@ -10,6 +10,7 @@ require (
 	github.com/mattn/go-isatty v0.0.14
 	github.com/stretchr/testify v1.7.0
 	github.com/ugorji/go/codec v1.2.6
+	golang.org/x/net v0.0.0-20210226172049-e18ecbb05110
 	google.golang.org/protobuf v1.27.1
 	gopkg.in/yaml.v2 v2.4.0
 )
diff --git a/go.sum b/go.sum
index 59efbf75d0..c01ba52431 100644
--- a/go.sum
+++ b/go.sum
@@ -53,6 +53,7 @@ github.com/ugorji/go/codec v1.2.6 h1:7kbGefxLoDBuYXOms4yD7223OpNMMPNPZxXk5TvFcyQ
 github.com/ugorji/go/codec v1.2.6/go.mod h1:V6TCNZ4PHqoHGFZuSG1W8nrCzzdgA2DozYxWFFpvxTw=
 golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97 h1:/UOmuWzQfxxo9UtlXMwuQU8CMgg1eZXqTRwkSQJWKOI=
 golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
+golang.org/x/net v0.0.0-20210226172049-e18ecbb05110 h1:qWPm9rbaAMKs8Bq/9LRpbMqxWRVUAQwMI9fVrssnTfw=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=