From e8e7d6cbd119d5916f1f8dfa415363568ede35f4 Mon Sep 17 00:00:00 2001
From: Sergey Matveev <stargrave@stargrave.org>
Date: Sat, 6 Dec 2014 15:18:40 +0300
Subject: [PATCH] FreeBSD TAP support

Signed-off-by: Sergey Matveev <stargrave@stargrave.org>
---
 README         |  2 +-
 govpn.go       | 14 ++++++++------
 tap_freebsd.go | 19 +++++++++++++++++++
 tap_linux.go   | 18 ++++++++++++++++++
 4 files changed, 46 insertions(+), 7 deletions(-)
 create mode 100644 tap_freebsd.go
 create mode 100644 tap_linux.go

diff --git a/README b/README
index 34d8be8..f436127 100644
--- a/README
+++ b/README
@@ -4,7 +4,7 @@ SYNOPSIS
 
 govpn is simple high-performance secure virtual private network daemon.
 It uses DH-EKE for mutual zero-knowledge authentication and
-authenticated encrypted transport.
+authenticated encrypted transport. It runs under GNU/Linux and FreeBSD.
 
 DESCRIPTION
 
diff --git a/govpn.go b/govpn.go
index fcd1a00..a06456d 100644
--- a/govpn.go
+++ b/govpn.go
@@ -22,13 +22,13 @@ import (
 	"encoding/hex"
 	"flag"
 	"fmt"
+	"io"
 	"log"
 	"net"
 	"time"
 
 	"code.google.com/p/go.crypto/poly1305"
 	"code.google.com/p/go.crypto/salsa20"
-	"github.com/chon219/water"
 )
 
 var (
@@ -48,6 +48,11 @@ const (
 	S20BS = 64
 )
 
+type TAP interface {
+	io.Reader
+	io.Writer
+}
+
 type Peer struct {
 	addr      *net.UDPAddr
 	key       *[KeySize]byte // encryption key
@@ -78,10 +83,7 @@ func main() {
 	// Interface listening
 	maxIfacePktSize := *mtu - poly1305.TagSize - NonceSize
 	log.Println("Max MTU", maxIfacePktSize, "on interface", *ifaceName)
-	iface, err := water.NewTAP(*ifaceName)
-	if err != nil {
-		panic(err)
-	}
+	iface := NewTAP(*ifaceName)
 	ethBuf := make([]byte, maxIfacePktSize)
 	ethSink := make(chan int)
 	ethSinkReady := make(chan bool)
@@ -236,7 +238,7 @@ func main() {
 			peer.nonceRecv = nonceRecv
 			timeouts = 0
 			if _, err := iface.Write(buf[S20BS : S20BS+udpPkt.size-NonceSize-poly1305.TagSize]); err != nil {
-				log.Println("Error writing to iface")
+				log.Println("Error writing to iface: ", err)
 			}
 			if *verbose {
 				fmt.Print("r")
diff --git a/tap_freebsd.go b/tap_freebsd.go
new file mode 100644
index 0000000..d4b45e6
--- /dev/null
+++ b/tap_freebsd.go
@@ -0,0 +1,19 @@
+// +build freebsd
+/*
+govpn -- high-performance secure virtual private network daemon
+Copyright (C) 2014 Sergey Matveev <stargrave@stargrave.org>
+*/
+package main
+
+import (
+	"os"
+	"path"
+)
+
+func NewTAP(ifaceName string) TAP {
+	fd, err := os.OpenFile(path.Join("/dev/", ifaceName), os.O_RDWR, os.ModePerm)
+	if err != nil {
+		panic(err)
+	}
+	return fd
+}
diff --git a/tap_linux.go b/tap_linux.go
new file mode 100644
index 0000000..90ece18
--- /dev/null
+++ b/tap_linux.go
@@ -0,0 +1,18 @@
+// +build linux
+/*
+govpn -- high-performance secure virtual private network daemon
+Copyright (C) 2014 Sergey Matveev <stargrave@stargrave.org>
+*/
+package main
+
+import (
+	"github.com/chon219/water"
+)
+
+func NewTAP(string ifaceName) TAP {
+	iface, err := water.NewTAP(ifaceName)
+	if err != nil {
+		panic(err)
+	}
+	return iface
+}
-- 
2.44.0