X-Git-Url: http://www.git.cypherpunks.ru/?a=blobdiff_plain;f=tap.go;h=6fbba6d3a32749e5d065dcb1281b06a78aaca5ba;hb=refs%2Fheads%2Fdevelop;hp=85926d7df9d1c4d290f85c77408251de0e50f417;hpb=6813fd50141426b87128f88126e2ce84df0925be;p=govpn.git

diff --git a/tap.go b/tap.go
index 85926d7..6fbba6d 100644
--- a/tap.go
+++ b/tap.go
@@ -1,11 +1,10 @@
 /*
 GoVPN -- simple secure free software virtual private network daemon
-Copyright (C) 2014-2015 Sergey Matveev <stargrave@stargrave.org>
+Copyright (C) 2014-2020 Sergey Matveev <stargrave@stargrave.org>
 
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
+the Free Software Foundation, version 3 of the License.
 
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -20,49 +19,65 @@ package govpn
 
 import (
 	"io"
-	"log"
-
-	"golang.org/x/crypto/poly1305"
 )
 
 type TAP struct {
-	Name  string
-	dev   io.ReadWriter
-	buf   []byte
-	sink  chan []byte
-	ready chan struct{}
+	Name string
+	Sink chan []byte
+	dev  io.ReadWriter
 }
 
-func NewTAP(ifaceName string) (*TAP, error) {
-	maxIfacePktSize := MTU - poly1305.TagSize - NonceSize
+var (
+	taps = make(map[string]*TAP)
+)
+
+func NewTAP(ifaceName string, mtu int) (*TAP, error) {
 	tapRaw, err := newTAPer(ifaceName)
 	if err != nil {
 		return nil, err
 	}
 	tap := TAP{
-		Name:  ifaceName,
-		dev:   tapRaw,
-		buf:   make([]byte, maxIfacePktSize),
-		sink:  make(chan []byte),
-		ready: make(chan struct{}),
+		Name: ifaceName,
+		dev:  tapRaw,
+		Sink: make(chan []byte),
 	}
 	go func() {
 		var n int
 		var err error
+		var buf []byte
+		buf0 := make([]byte, mtu)
+		buf1 := make([]byte, mtu)
+		bufZ := false
 		for {
-			<-tap.ready
-			n, err = tap.dev.Read(tap.buf)
+			if bufZ {
+				buf = buf0
+			} else {
+				buf = buf1
+			}
+			bufZ = !bufZ
+			n, err = tap.dev.Read(buf)
 			if err != nil {
-				panic(err)
+				panic("Reading TUN/TAP:" + err.Error())
 			}
-			tap.sink <- tap.buf[:n]
+			tap.Sink <- buf[:n]
 		}
 	}()
 	return &tap, nil
 }
 
-func (t *TAP) Write(data []byte) {
-	if _, err := t.dev.Write(data); err != nil {
-		log.Println("Error writing to iface: ", err)
+func (t *TAP) Write(data []byte) (n int, err error) {
+	return t.dev.Write(data)
+}
+
+func TAPListen(ifaceName string, mtu int) (*TAP, error) {
+	tap, exists := taps[ifaceName]
+	if exists {
+		return tap, nil
+	}
+	tap, err := NewTAP(ifaceName, mtu)
+	if err != nil {
+		return nil, err
 	}
+	taps[ifaceName] = tap
+	return tap, nil
 }