From 6ab42b01fd63aa277f0ce2786b81edde2625c078 Mon Sep 17 00:00:00 2001
From: fangdingjun <fangdingjun@gmail.com>
Date: Tue, 19 Jan 2016 11:13:57 +0800
Subject: [PATCH]  Initial commit

---
 .gitignore |  3 +++
 README.md  | 41 +++++++++++++++++++++++++++++++++++++
 local.go   | 53 +++++++++++++++++++++++++++++++++++++++++++++++
 main.go    | 39 +++++++++++++++++++++++++++++++++++
 server.go  | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 196 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 README.md
 create mode 100644 local.go
 create mode 100644 main.go
 create mode 100644 server.go

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..0d5cdd8
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+gtunnel*
+*~
+*bak
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..2d10043
--- /dev/null
+++ b/README.md
@@ -0,0 +1,41 @@
+gtunnel
+======
+
+A stunnel like util write by golang
+
+There are two work mode.
+
+Client mode
+==========
+
+In this mode, listen for incoming plain connections and forward to server to use SSL/TLS connections
+
+Server mode
+===========
+
+In this mode, listen for incoming SSL/TLS connections and forward to backend use plain connections
+
+Build
+====
+
+    go get github.com/fangdingjun/gtunnel
+    cd $GOPATH/src/github.com/fangdingjun/gtunnel
+    go build
+
+Usage
+====
+
+server mode
+
+    ./gtunnel --server --cert server.crt --key server.key --port 8001 --remote 127.0.0.1:80
+
+listen for SSL/TLS connections on port 8001 and forward to 127.0.0.1:80
+
+client mode
+
+    ./gtunnel --client --port 8002 --remote www.example.com:8081
+
+listen for plain connections on port 8002 and forward to www.example.com:8081 to use SSL/TLS connections
+
+use `./gtunnel -h` see more options
+
diff --git a/local.go b/local.go
new file mode 100644
index 0000000..7a4e64e
--- /dev/null
+++ b/local.go
@@ -0,0 +1,53 @@
+package main
+
+import (
+	"crypto/tls"
+	"fmt"
+	"io"
+	"log"
+	"net"
+)
+
+//var server string = "www.ratafee.nl:443"
+
+func local_main() {
+	l, err := net.Listen("tcp", fmt.Sprintf(":%d", port))
+	if err != nil {
+		log.Fatal(err)
+	}
+	log.Printf("Listen on %s...", l.Addr())
+	defer l.Close()
+
+	for {
+		c, err := l.Accept()
+		if err != nil {
+			log.Println(err)
+			continue
+		}
+		go handle_local(c)
+	}
+}
+
+func handle_local(c net.Conn) {
+	//defer c.Close()
+	log.Printf("accept connection from %s", c.RemoteAddr())
+	log.Printf("connect to %s...", remote)
+	s, err := tls.Dial("tcp", remote, nil)
+	if err != nil {
+		log.Printf("connect to %s failed: %s", remote, err.Error())
+		c.Close()
+		return
+	}
+	ch := make(chan int)
+	//defer s.Close()
+	go func() {
+		count, _ := io.Copy(s, c)
+		log.Printf("write %d bytes to %s", count, s.RemoteAddr())
+		s.Close()
+		ch <- 1
+	}()
+	co, _ := io.Copy(c, s)
+	log.Printf("write %d bytes to %s", co, c.RemoteAddr())
+	c.Close()
+	<-ch
+}
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..836834b
--- /dev/null
+++ b/main.go
@@ -0,0 +1,39 @@
+package main
+
+import (
+	"flag"
+	"github.com/fangdingjun/iniflags"
+	"log"
+)
+
+var remote string
+
+func main() {
+	var server, client bool
+	flag.StringVar(&remote, "remote", "", "remote server")
+	flag.IntVar(&port, "port", 8080, "the listen port")
+	flag.BoolVar(&server, "server", false, "tls server mode")
+	flag.BoolVar(&client, "client", false, "tls client mode")
+	flag.StringVar(&cert, "cert", "", "the certificate file")
+	flag.StringVar(&key, "key", "", "the private key")
+	iniflags.Parse()
+
+	if remote == "" {
+		log.Fatal("please use --remote to special the server")
+	}
+
+	if server {
+		if cert == "" || key == "" {
+			log.Fatal("in server mode, you must special the certificate and private key")
+		}
+		server_main()
+		return
+	}
+
+	if client {
+		local_main()
+		return
+	}
+
+	log.Fatal("please use --server or --client to special a work mode")
+}
diff --git a/server.go b/server.go
new file mode 100644
index 0000000..df2b59a
--- /dev/null
+++ b/server.go
@@ -0,0 +1,60 @@
+package main
+
+import (
+	"crypto/tls"
+	"fmt"
+	"io"
+	"log"
+	"net"
+)
+
+//var backend = "127.0.0.1:8080"
+var cert = "server.crt"
+var key = "server.key"
+var port = 9000
+
+func server_main() {
+	certificate, err := tls.LoadX509KeyPair(cert, key)
+	if err != nil {
+		log.Fatal(err)
+	}
+	l, err := tls.Listen("tcp", fmt.Sprintf(":%d", port), &tls.Config{
+		Certificates: []tls.Certificate{certificate},
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer l.Close()
+
+	for {
+		c, err := l.Accept()
+		if err != nil {
+			log.Println(err)
+			continue
+		}
+		go handle_server(c)
+	}
+}
+
+func handle_server(c net.Conn) {
+	log.Printf("accept connection from %s", c.RemoteAddr())
+	s, err := net.Dial("tcp", remote)
+	if err != nil {
+		log.Println(err)
+		c.Close()
+		return
+	}
+
+	ch := make(chan int)
+	go func() {
+		count, _ := io.Copy(s, c)
+		s.Close()
+		log.Printf("write %d bytes to %s", count, s.RemoteAddr())
+		ch <- 1
+	}()
+
+	co, _ := io.Copy(c, s)
+	c.Close()
+	log.Printf("write %d bytes to %s", co, c.RemoteAddr())
+	<-ch
+}