Refactor ssl-passthroug using go to handle TLS hello

controllers/nginx/pkg/cmd/controller/tcp.go

@@ -0,0 +1,90 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"net"
+
+	"github.com/golang/glog"
+	"github.com/paultag/sniff/parser"
+)
+
+type server struct {
+	Hostname string
+	IP       string
+	Port     int
+}
+
+type proxy struct {
+	ServerList []*server
+	Default    *server
+}
+
+func (p *proxy) Get(host string) *server {
+	for _, s := range p.ServerList {
+		if s.Hostname == host {
+			return s
+		}
+	}
+
+	return &server{
+		Hostname: "localhost",
+		IP:       "127.0.0.1",
+		Port:     442,
+	}
+}
+
+func (p *proxy) Handle(conn net.Conn) {
+	defer conn.Close()
+	data := make([]byte, 4096)
+
+	length, err := conn.Read(data)
+	if err != nil {
+		glog.V(4).Infof("error reading the first 4k of the connection: %s", err)
+		return
+	}
+
+	var proxy *server
+	hostname, err := parser.GetHostname(data[:])
+	if err == nil {
+		glog.V(3).Infof("parsed hostname from TLS Client Hello: %s", hostname)
+		proxy = p.Get(hostname)
+		if proxy == nil {
+			return
+		}
+	} else {
+		proxy = p.Default
+		if proxy == nil {
+			return
+		}
+	}
+
+	clientConn, err := net.Dial("tcp", fmt.Sprintf("%s:%d", proxy.IP, proxy.Port))
+	if err != nil {
+		return
+	}
+	defer clientConn.Close()
+
+	_, err = clientConn.Write(data[:length])
+	if err != nil {
+		clientConn.Close()
+	}
+	pipe(clientConn, conn)
+}
+
+func pipe(client, server net.Conn) {
+	doCopy := func(s, c net.Conn, cancel chan<- bool) {
+		io.Copy(s, c)
+		cancel <- true
+	}
+
+	cancel := make(chan bool, 2)
+
+	go doCopy(server, client, cancel)
+	go doCopy(client, server, cancel)
+
+	select {
+	case <-cancel:
+		return
+	}
+}