Merge pull request #13 from Jigsaw-Code/bemasc-sni

Report SNI in retry stats

go.mod

@@ -3,6 +3,7 @@ module github.com/Jigsaw-Code/outline-go-tun2socks
 go 1.12
 
 require (
+	github.com/Jigsaw-Code/getsni v0.0.0-20190807203514-efe2dbf35d1f
 	github.com/eycorsican/go-tun2socks v1.14.2
 	github.com/karalabe/xgo v0.0.0-20190301120235-2d6d1848fb02 // indirect
 	github.com/miekg/dns v1.1.12 // indirect

go.sum

@@ -1,4 +1,6 @@
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
+github.com/Jigsaw-Code/getsni v0.0.0-20190807203514-efe2dbf35d1f h1:PT61aMvdZPh/8L5FjmKu8DS4/VnmwSJICVZ/THpmLF0=
+github.com/Jigsaw-Code/getsni v0.0.0-20190807203514-efe2dbf35d1f/go.mod h1:C68VBkZJR/wcvgo6pmdlm6snMHWiLE844lXJ028Qh8Y=
 github.com/eycorsican/go-tun2socks v1.12.0 h1:sW+Bdy3IenYoIh8zDICdNPEQabaS0Uv9BaRMcqIxum8=
 github.com/eycorsican/go-tun2socks v1.12.0/go.mod h1:itJVcg8T4Lc1r+72CNpCV/SUNO8of0z/jFeAt31cQbA=
 github.com/eycorsican/go-tun2socks v1.13.0 h1:t+k1+mt5xvS8iWhmrYKEAiIWArQqSFJUU/B5Ivivjws=
@@ -18,6 +20,7 @@ golang.org/x/crypto v0.0.0-20190313024323-a1f597ede03a h1:YX8ljsm6wXlHZO+aRz9Exq
 golang.org/x/crypto v0.0.0-20190313024323-a1f597ede03a/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20190325154230-a5d413f7728c h1:Vj5n4GlwjmQteupaxJ9+0FNOmBrHfq7vN4btdGoDZgI=
 golang.org/x/crypto v0.0.0-20190325154230-a5d413f7728c/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20190513172903-22d7a77e9e5f h1:R423Cnkcp5JABoeemiGEPlt9tHXFfw5kvc0yqlxRPWo=
 golang.org/x/crypto v0.0.0-20190513172903-22d7a77e9e5f/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/exp v0.0.0-20190306152737-a1d7652674e8/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190321205749-f0864edee7f3/go.mod h1:ZjyILWgesfNpC6sMxTJOJm9Kp84zZh5NQWvqDGG3Qr8=

tunnel/intra/retrier.go

@@ -6,13 +6,16 @@ import (
 	"net"
 	"sync"
 	"time"
+
+	"github.com/Jigsaw-Code/getsni"
 )
 
 type RetryStats struct {
-	Bytes   int32 // Number of bytes uploaded before the retry.
-	Chunks  int16 // Number of writes before the retry.
-	Split   int16 // Number of bytes in the first retried segment.
-	Timeout bool  // True if the retry was caused by a timeout.
+	SNI     string // TLS SNI observed, if present.
+	Bytes   int32  // Number of bytes uploaded before the retry.
+	Chunks  int16  // Number of writes before the retry.
+	Split   int16  // Number of bytes in the first retried segment.
+	Timeout bool   // True if the retry was caused by a timeout.
 }
 
 // retrier implements the DuplexConn interface.
@@ -204,8 +207,12 @@ func (r *retrier) Write(b []byte) (int, error) {
 			n, err = r.conn.Write(b)
 			attempted = true
 			r.hello = append(r.hello, b[:n]...)
+
 			r.stats.Chunks++
 			r.stats.Bytes = int32(len(r.hello))
+			if r.stats.SNI == "" {
+				r.stats.SNI, _ = getsni.GetSNI(r.hello)
+			}
 
 			// We require a response or another write within the specified timeout.
 			r.conn.SetReadDeadline(time.Now().Add(r.timeout))