Raise copyright years

[govpn.git] / tap.go

diff --git a/tap.go b/tap.go
index a80795534a70adf431b183c5d339e2ca61c51706..6fbba6d3a32749e5d065dcb1281b06a78aaca5ba 100644 (file)
--- 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
@@ -20,53 +19,47 @@ package govpn
 
 import (
        "io"
-
-       "golang.org/x/crypto/poly1305"
-)
-
-const (
-       EtherSize = 14
 )
 
 type TAP struct {
-       Name   string
-       dev    io.ReadWriter
-       buf    []byte
-       sink   chan []byte
-       ready  chan struct{}
-       synced bool
+       Name string
+       Sink chan []byte
+       dev  io.ReadWriter
 }
 
-// Return maximal acceptable TAP interface MTU. This is daemon's MTU
-// minus nonce, MAC, packet size mark and Ethernet header sizes.
-func TAPMaxMTU() int {
-       return MTU - poly1305.TagSize - NonceSize - PktSizeSize - EtherSize
-}
+var (
+       taps = make(map[string]*TAP)
+)
 
-func NewTAP(ifaceName string) (*TAP, error) {
-       maxIfacePktSize := TAPMaxMTU() + EtherSize
+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{}),
-               synced: false,
+               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
@@ -75,3 +68,16 @@ func NewTAP(ifaceName string) (*TAP, error) {
 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
+}