From 1a1c3d096888816c94cf1eb7c2747e83f008549f Mon Sep 17 00:00:00 2001 From: David Crawshaw Date: Tue, 7 Jan 2020 07:43:17 -0800 Subject: [PATCH] tuntest: split out testing package This code is useful to other packages writing tests. Signed-off-by: David Crawshaw --- device/device_test.go | 146 ++------------------------------------- tun/tuntest/tuntest.go | 150 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 155 insertions(+), 141 deletions(-) create mode 100644 tun/tuntest/tuntest.go diff --git a/device/device_test.go b/device/device_test.go index 14cc605..87ecfc8 100644 --- a/device/device_test.go +++ b/device/device_test.go @@ -8,15 +8,12 @@ package device import ( "bufio" "bytes" - "encoding/binary" - "io" "net" - "os" "strings" "testing" "time" - "golang.zx2c4.com/wireguard/tun" + "golang.zx2c4.com/wireguard/tun/tuntest" ) func TestTwoDevicePing(t *testing.T) { @@ -29,7 +26,7 @@ protocol_version=1 replace_allowed_ips=true allowed_ip=1.0.0.2/32 endpoint=127.0.0.1:53512` - tun1 := NewChannelTUN() + tun1 := tuntest.NewChannelTUN() dev1 := NewDevice(tun1.TUN(), NewLogger(LogLevelDebug, "dev1: ")) dev1.Up() defer dev1.Close() @@ -45,7 +42,7 @@ protocol_version=1 replace_allowed_ips=true allowed_ip=1.0.0.1/32 endpoint=127.0.0.1:53511` - tun2 := NewChannelTUN() + tun2 := tuntest.NewChannelTUN() dev2 := NewDevice(tun2.TUN(), NewLogger(LogLevelDebug, "dev2: ")) dev2.Up() defer dev2.Close() @@ -54,7 +51,7 @@ endpoint=127.0.0.1:53511` } t.Run("ping 1.0.0.1", func(t *testing.T) { - msg2to1 := ping(net.ParseIP("1.0.0.1"), net.ParseIP("1.0.0.2")) + msg2to1 := tuntest.Ping(net.ParseIP("1.0.0.1"), net.ParseIP("1.0.0.2")) tun2.Outbound <- msg2to1 select { case msgRecv := <-tun1.Inbound: @@ -67,7 +64,7 @@ endpoint=127.0.0.1:53511` }) t.Run("ping 1.0.0.2", func(t *testing.T) { - msg1to2 := ping(net.ParseIP("1.0.0.2"), net.ParseIP("1.0.0.1")) + msg1to2 := tuntest.Ping(net.ParseIP("1.0.0.2"), net.ParseIP("1.0.0.1")) tun1.Outbound <- msg1to2 select { case msgRecv := <-tun2.Inbound: @@ -80,139 +77,6 @@ endpoint=127.0.0.1:53511` }) } -func ping(dst, src net.IP) []byte { - localPort := uint16(1337) - seq := uint16(0) - - payload := make([]byte, 4) - binary.BigEndian.PutUint16(payload[0:], localPort) - binary.BigEndian.PutUint16(payload[2:], seq) - - return genICMPv4(payload, dst, src) -} - -// checksum is the "internet checksum" from https://tools.ietf.org/html/rfc1071. -func checksum(buf []byte, initial uint16) uint16 { - v := uint32(initial) - for i := 0; i < len(buf)-1; i += 2 { - v += uint32(binary.BigEndian.Uint16(buf[i:])) - } - if len(buf)%2 == 1 { - v += uint32(buf[len(buf)-1]) << 8 - } - for v > 0xffff { - v = (v >> 16) + (v & 0xffff) - } - return ^uint16(v) -} - -func genICMPv4(payload []byte, dst, src net.IP) []byte { - const ( - icmpv4ProtocolNumber = 1 - icmpv4Echo = 8 - icmpv4ChecksumOffset = 2 - icmpv4Size = 8 - ipv4Size = 20 - ipv4TotalLenOffset = 2 - ipv4ChecksumOffset = 10 - ttl = 65 - ) - - hdr := make([]byte, ipv4Size+icmpv4Size) - - ip := hdr[0:ipv4Size] - icmpv4 := hdr[ipv4Size : ipv4Size+icmpv4Size] - - // https://tools.ietf.org/html/rfc792 - icmpv4[0] = icmpv4Echo // type - icmpv4[1] = 0 // code - chksum := ^checksum(icmpv4, checksum(payload, 0)) - binary.BigEndian.PutUint16(icmpv4[icmpv4ChecksumOffset:], chksum) - - // https://tools.ietf.org/html/rfc760 section 3.1 - length := uint16(len(hdr) + len(payload)) - ip[0] = (4 << 4) | (ipv4Size / 4) - binary.BigEndian.PutUint16(ip[ipv4TotalLenOffset:], length) - ip[8] = ttl - ip[9] = icmpv4ProtocolNumber - copy(ip[12:], src.To4()) - copy(ip[16:], dst.To4()) - chksum = ^checksum(ip[:], 0) - binary.BigEndian.PutUint16(ip[ipv4ChecksumOffset:], chksum) - - var v []byte - v = append(v, hdr...) - v = append(v, payload...) - return []byte(v) -} - -// TODO(crawshaw): find a reusable home for this. package devicetest? -type ChannelTUN struct { - Inbound chan []byte // incoming packets, closed on TUN close - Outbound chan []byte // outbound packets, blocks forever on TUN close - - closed chan struct{} - events chan tun.Event - tun chTun -} - -func NewChannelTUN() *ChannelTUN { - c := &ChannelTUN{ - Inbound: make(chan []byte), - Outbound: make(chan []byte), - closed: make(chan struct{}), - events: make(chan tun.Event, 1), - } - c.tun.c = c - c.events <- tun.EventUp - return c -} - -func (c *ChannelTUN) TUN() tun.Device { - return &c.tun -} - -type chTun struct { - c *ChannelTUN -} - -func (t *chTun) File() *os.File { return nil } - -func (t *chTun) Read(data []byte, offset int) (int, error) { - select { - case <-t.c.closed: - return 0, io.EOF // TODO(crawshaw): what is the correct error value? - case msg := <-t.c.Outbound: - return copy(data[offset:], msg), nil - } -} - -// Write is called by the wireguard device to deliver a packet for routing. -func (t *chTun) Write(data []byte, offset int) (int, error) { - if offset == -1 { - close(t.c.closed) - close(t.c.events) - return 0, io.EOF - } - msg := make([]byte, len(data)-offset) - copy(msg, data[offset:]) - select { - case <-t.c.closed: - return 0, io.EOF // TODO(crawshaw): what is the correct error value? - case t.c.Inbound <- msg: - return len(data) - offset, nil - } -} - -func (t *chTun) Flush() error { return nil } -func (t *chTun) MTU() (int, error) { return DefaultMTU, nil } -func (t *chTun) Name() (string, error) { return "loopbackTun1", nil } -func (t *chTun) Events() chan tun.Event { return t.c.events } -func (t *chTun) Close() error { - t.Write(nil, -1) - return nil -} - func assertNil(t *testing.T, err error) { if err != nil { t.Fatal(err) diff --git a/tun/tuntest/tuntest.go b/tun/tuntest/tuntest.go new file mode 100644 index 0000000..bdd96ac --- /dev/null +++ b/tun/tuntest/tuntest.go @@ -0,0 +1,150 @@ +/* SPDX-License-Identifier: MIT + * + * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved. + */ + +package tuntest + +import ( + "encoding/binary" + "io" + "net" + "os" + + "golang.zx2c4.com/wireguard/tun" +) + +func Ping(dst, src net.IP) []byte { + localPort := uint16(1337) + seq := uint16(0) + + payload := make([]byte, 4) + binary.BigEndian.PutUint16(payload[0:], localPort) + binary.BigEndian.PutUint16(payload[2:], seq) + + return genICMPv4(payload, dst, src) +} + +// Checksum is the "internet checksum" from https://tools.ietf.org/html/rfc1071. +func checksum(buf []byte, initial uint16) uint16 { + v := uint32(initial) + for i := 0; i < len(buf)-1; i += 2 { + v += uint32(binary.BigEndian.Uint16(buf[i:])) + } + if len(buf)%2 == 1 { + v += uint32(buf[len(buf)-1]) << 8 + } + for v > 0xffff { + v = (v >> 16) + (v & 0xffff) + } + return ^uint16(v) +} + +func genICMPv4(payload []byte, dst, src net.IP) []byte { + const ( + icmpv4ProtocolNumber = 1 + icmpv4Echo = 8 + icmpv4ChecksumOffset = 2 + icmpv4Size = 8 + ipv4Size = 20 + ipv4TotalLenOffset = 2 + ipv4ChecksumOffset = 10 + ttl = 65 + ) + + hdr := make([]byte, ipv4Size+icmpv4Size) + + ip := hdr[0:ipv4Size] + icmpv4 := hdr[ipv4Size : ipv4Size+icmpv4Size] + + // https://tools.ietf.org/html/rfc792 + icmpv4[0] = icmpv4Echo // type + icmpv4[1] = 0 // code + chksum := ^checksum(icmpv4, checksum(payload, 0)) + binary.BigEndian.PutUint16(icmpv4[icmpv4ChecksumOffset:], chksum) + + // https://tools.ietf.org/html/rfc760 section 3.1 + length := uint16(len(hdr) + len(payload)) + ip[0] = (4 << 4) | (ipv4Size / 4) + binary.BigEndian.PutUint16(ip[ipv4TotalLenOffset:], length) + ip[8] = ttl + ip[9] = icmpv4ProtocolNumber + copy(ip[12:], src.To4()) + copy(ip[16:], dst.To4()) + chksum = ^checksum(ip[:], 0) + binary.BigEndian.PutUint16(ip[ipv4ChecksumOffset:], chksum) + + var v []byte + v = append(v, hdr...) + v = append(v, payload...) + return []byte(v) +} + +// TODO(crawshaw): find a reusable home for this. package devicetest? +type ChannelTUN struct { + Inbound chan []byte // incoming packets, closed on TUN close + Outbound chan []byte // outbound packets, blocks forever on TUN close + + closed chan struct{} + events chan tun.Event + tun chTun +} + +func NewChannelTUN() *ChannelTUN { + c := &ChannelTUN{ + Inbound: make(chan []byte), + Outbound: make(chan []byte), + closed: make(chan struct{}), + events: make(chan tun.Event, 1), + } + c.tun.c = c + c.events <- tun.EventUp + return c +} + +func (c *ChannelTUN) TUN() tun.Device { + return &c.tun +} + +type chTun struct { + c *ChannelTUN +} + +func (t *chTun) File() *os.File { return nil } + +func (t *chTun) Read(data []byte, offset int) (int, error) { + select { + case <-t.c.closed: + return 0, io.EOF // TODO(crawshaw): what is the correct error value? + case msg := <-t.c.Outbound: + return copy(data[offset:], msg), nil + } +} + +// Write is called by the wireguard device to deliver a packet for routing. +func (t *chTun) Write(data []byte, offset int) (int, error) { + if offset == -1 { + close(t.c.closed) + close(t.c.events) + return 0, io.EOF + } + msg := make([]byte, len(data)-offset) + copy(msg, data[offset:]) + select { + case <-t.c.closed: + return 0, io.EOF // TODO(crawshaw): what is the correct error value? + case t.c.Inbound <- msg: + return len(data) - offset, nil + } +} + +const DefaultMTU = 1420 + +func (t *chTun) Flush() error { return nil } +func (t *chTun) MTU() (int, error) { return DefaultMTU, nil } +func (t *chTun) Name() (string, error) { return "loopbackTun1", nil } +func (t *chTun) Events() chan tun.Event { return t.c.events } +func (t *chTun) Close() error { + t.Write(nil, -1) + return nil +}