488 lines
11 KiB
Go
488 lines
11 KiB
Go
// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package tstun
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import (
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"bytes"
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"encoding/binary"
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"fmt"
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"strconv"
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"strings"
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"sync/atomic"
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"testing"
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"unsafe"
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"golang.zx2c4.com/wireguard/tun/tuntest"
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"inet.af/netaddr"
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"tailscale.com/net/packet"
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"tailscale.com/types/ipproto"
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"tailscale.com/types/logger"
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"tailscale.com/wgengine/filter"
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)
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func udp4(src, dst string, sport, dport uint16) []byte {
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sip, err := netaddr.ParseIP(src)
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if err != nil {
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panic(err)
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}
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dip, err := netaddr.ParseIP(dst)
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if err != nil {
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panic(err)
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}
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header := &packet.UDP4Header{
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IP4Header: packet.IP4Header{
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Src: sip,
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Dst: dip,
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IPID: 0,
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},
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SrcPort: sport,
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DstPort: dport,
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}
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return packet.Generate(header, []byte("udp_payload"))
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}
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func tcp4syn(src, dst string, sport, dport uint16) []byte {
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sip, err := netaddr.ParseIP(src)
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if err != nil {
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panic(err)
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}
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dip, err := netaddr.ParseIP(dst)
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if err != nil {
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panic(err)
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}
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ipHeader := packet.IP4Header{
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IPProto: ipproto.TCP,
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Src: sip,
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Dst: dip,
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IPID: 0,
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}
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tcpHeader := make([]byte, 20)
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binary.BigEndian.PutUint16(tcpHeader[0:], sport)
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binary.BigEndian.PutUint16(tcpHeader[2:], dport)
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tcpHeader[13] |= 2 // SYN
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both := packet.Generate(ipHeader, tcpHeader)
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// 20 byte IP4 + 20 byte TCP
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binary.BigEndian.PutUint16(both[2:4], 40)
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return both
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}
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func nets(nets ...string) (ret []netaddr.IPPrefix) {
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for _, s := range nets {
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if i := strings.IndexByte(s, '/'); i == -1 {
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ip, err := netaddr.ParseIP(s)
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if err != nil {
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panic(err)
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}
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bits := uint8(32)
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if ip.Is6() {
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bits = 128
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}
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ret = append(ret, netaddr.IPPrefixFrom(ip, bits))
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} else {
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pfx, err := netaddr.ParseIPPrefix(s)
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if err != nil {
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panic(err)
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}
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ret = append(ret, pfx)
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}
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}
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return ret
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}
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func ports(s string) filter.PortRange {
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if s == "*" {
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return filter.PortRange{First: 0, Last: 65535}
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}
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var fs, ls string
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i := strings.IndexByte(s, '-')
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if i == -1 {
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fs = s
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ls = fs
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} else {
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fs = s[:i]
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ls = s[i+1:]
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}
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first, err := strconv.ParseInt(fs, 10, 16)
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if err != nil {
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panic(fmt.Sprintf("invalid NetPortRange %q", s))
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}
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last, err := strconv.ParseInt(ls, 10, 16)
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if err != nil {
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panic(fmt.Sprintf("invalid NetPortRange %q", s))
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}
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return filter.PortRange{First: uint16(first), Last: uint16(last)}
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}
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func netports(netPorts ...string) (ret []filter.NetPortRange) {
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for _, s := range netPorts {
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i := strings.LastIndexByte(s, ':')
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if i == -1 {
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panic(fmt.Sprintf("invalid NetPortRange %q", s))
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}
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npr := filter.NetPortRange{
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Net: nets(s[:i])[0],
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Ports: ports(s[i+1:]),
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}
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ret = append(ret, npr)
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}
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return ret
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}
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func setfilter(logf logger.Logf, tun *Wrapper) {
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protos := []ipproto.Proto{
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ipproto.TCP,
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ipproto.UDP,
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}
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matches := []filter.Match{
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{IPProto: protos, Srcs: nets("5.6.7.8"), Dsts: netports("1.2.3.4:89-90")},
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{IPProto: protos, Srcs: nets("1.2.3.4"), Dsts: netports("5.6.7.8:98")},
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}
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var sb netaddr.IPSetBuilder
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sb.AddPrefix(netaddr.MustParseIPPrefix("1.2.0.0/16"))
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ipSet, _ := sb.IPSet()
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tun.SetFilter(filter.New(matches, ipSet, ipSet, nil, logf))
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}
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func newChannelTUN(logf logger.Logf, secure bool) (*tuntest.ChannelTUN, *Wrapper) {
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chtun := tuntest.NewChannelTUN()
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tun := Wrap(logf, chtun.TUN())
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if secure {
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setfilter(logf, tun)
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} else {
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tun.disableFilter = true
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}
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return chtun, tun
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}
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func newFakeTUN(logf logger.Logf, secure bool) (*fakeTUN, *Wrapper) {
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ftun := NewFake()
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tun := Wrap(logf, ftun)
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if secure {
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setfilter(logf, tun)
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} else {
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tun.disableFilter = true
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}
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return ftun.(*fakeTUN), tun
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}
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func TestReadAndInject(t *testing.T) {
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chtun, tun := newChannelTUN(t.Logf, false)
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defer tun.Close()
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const size = 2 // all payloads have this size
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written := []string{"w0", "w1"}
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injected := []string{"i0", "i1"}
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go func() {
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for _, packet := range written {
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payload := []byte(packet)
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chtun.Outbound <- payload
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}
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}()
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for _, packet := range injected {
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go func(packet string) {
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payload := []byte(packet)
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err := tun.InjectOutbound(payload)
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if err != nil {
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t.Errorf("%s: error: %v", packet, err)
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}
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}(packet)
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}
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var buf [MaxPacketSize]byte
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var seen = make(map[string]bool)
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// We expect the same packets back, in no particular order.
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for i := 0; i < len(written)+len(injected); i++ {
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n, err := tun.Read(buf[:], 0)
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if err != nil {
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t.Errorf("read %d: error: %v", i, err)
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}
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if n != size {
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t.Errorf("read %d: got size %d; want %d", i, n, size)
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}
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got := string(buf[:n])
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t.Logf("read %d: got %s", i, got)
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seen[got] = true
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}
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for _, packet := range written {
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if !seen[packet] {
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t.Errorf("%s not received", packet)
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}
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}
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for _, packet := range injected {
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if !seen[packet] {
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t.Errorf("%s not received", packet)
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}
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}
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}
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func TestWriteAndInject(t *testing.T) {
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chtun, tun := newChannelTUN(t.Logf, false)
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defer tun.Close()
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const size = 2 // all payloads have this size
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written := []string{"w0", "w1"}
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injected := []string{"i0", "i1"}
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go func() {
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for _, packet := range written {
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payload := []byte(packet)
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n, err := tun.Write(payload, 0)
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if err != nil {
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t.Errorf("%s: error: %v", packet, err)
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}
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if n != size {
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t.Errorf("%s: got size %d; want %d", packet, n, size)
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}
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}
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}()
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for _, packet := range injected {
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go func(packet string) {
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payload := []byte(packet)
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err := tun.InjectInboundCopy(payload)
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if err != nil {
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t.Errorf("%s: error: %v", packet, err)
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}
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}(packet)
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}
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seen := make(map[string]bool)
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// We expect the same packets back, in no particular order.
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for i := 0; i < len(written)+len(injected); i++ {
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packet := <-chtun.Inbound
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got := string(packet)
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t.Logf("read %d: got %s", i, got)
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seen[got] = true
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}
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for _, packet := range written {
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if !seen[packet] {
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t.Errorf("%s not received", packet)
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}
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}
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for _, packet := range injected {
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if !seen[packet] {
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t.Errorf("%s not received", packet)
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}
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}
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}
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func TestFilter(t *testing.T) {
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chtun, tun := newChannelTUN(t.Logf, true)
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defer tun.Close()
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type direction int
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const (
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in direction = iota
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out
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)
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tests := []struct {
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name string
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dir direction
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drop bool
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data []byte
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}{
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{"junk_in", in, true, []byte("\x45not a valid IPv4 packet")},
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{"junk_out", out, true, []byte("\x45not a valid IPv4 packet")},
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{"bad_port_in", in, true, udp4("5.6.7.8", "1.2.3.4", 22, 22)},
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{"bad_port_out", out, false, udp4("1.2.3.4", "5.6.7.8", 22, 22)},
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{"bad_ip_in", in, true, udp4("8.1.1.1", "1.2.3.4", 89, 89)},
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{"bad_ip_out", out, false, udp4("1.2.3.4", "8.1.1.1", 98, 98)},
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{"good_packet_in", in, false, udp4("5.6.7.8", "1.2.3.4", 89, 89)},
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{"good_packet_out", out, false, udp4("1.2.3.4", "5.6.7.8", 98, 98)},
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}
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// A reader on the other end of the tun.
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go func() {
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var recvbuf []byte
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for {
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select {
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case <-tun.closed:
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return
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case recvbuf = <-chtun.Inbound:
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// continue
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}
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for _, tt := range tests {
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if tt.drop && bytes.Equal(recvbuf, tt.data) {
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t.Errorf("did not drop %s", tt.name)
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}
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}
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}
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}()
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var buf [MaxPacketSize]byte
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for _, tt := range tests {
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t.Run(tt.name, func(t *testing.T) {
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var n int
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var err error
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var filtered bool
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if tt.dir == in {
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// Use the side effect of updating the last
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// activity atomic to determine whether the
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// data was actually filtered.
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// If it stays zero, nothing made it through
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// to the wrapped TUN.
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atomic.StoreInt64(&tun.lastActivityAtomic, 0)
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_, err = tun.Write(tt.data, 0)
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filtered = atomic.LoadInt64(&tun.lastActivityAtomic) == 0
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} else {
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chtun.Outbound <- tt.data
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n, err = tun.Read(buf[:], 0)
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// In the read direction, errors are fatal, so we return n = 0 instead.
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filtered = (n == 0)
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}
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if err != nil {
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t.Errorf("got err %v; want nil", err)
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}
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if filtered {
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if !tt.drop {
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t.Errorf("got drop; want accept")
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}
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} else {
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if tt.drop {
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t.Errorf("got accept; want drop")
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}
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}
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})
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}
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}
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func TestAllocs(t *testing.T) {
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ftun, tun := newFakeTUN(t.Logf, false)
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defer tun.Close()
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buf := []byte{0x00}
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allocs := testing.AllocsPerRun(100, func() {
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_, err := ftun.Write(buf, 0)
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if err != nil {
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t.Errorf("write: error: %v", err)
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return
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}
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})
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if allocs > 0 {
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t.Errorf("read allocs = %v; want 0", allocs)
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}
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}
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func TestClose(t *testing.T) {
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ftun, tun := newFakeTUN(t.Logf, false)
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data := udp4("1.2.3.4", "5.6.7.8", 98, 98)
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_, err := ftun.Write(data, 0)
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if err != nil {
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t.Error(err)
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}
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tun.Close()
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_, err = ftun.Write(data, 0)
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if err == nil {
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t.Error("Expected error from ftun.Write() after Close()")
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}
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}
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func BenchmarkWrite(b *testing.B) {
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ftun, tun := newFakeTUN(b.Logf, true)
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defer tun.Close()
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packet := udp4("5.6.7.8", "1.2.3.4", 89, 89)
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for i := 0; i < b.N; i++ {
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_, err := ftun.Write(packet, 0)
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if err != nil {
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b.Errorf("err = %v; want nil", err)
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}
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}
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}
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func TestAtomic64Alignment(t *testing.T) {
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off := unsafe.Offsetof(Wrapper{}.lastActivityAtomic)
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if off%8 != 0 {
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t.Errorf("offset %v not 8-byte aligned", off)
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}
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c := new(Wrapper)
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atomic.StoreInt64(&c.lastActivityAtomic, 123)
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}
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func TestPeerAPIBypass(t *testing.T) {
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wrapperWithPeerAPI := &Wrapper{
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PeerAPIPort: func(ip netaddr.IP) (port uint16, ok bool) {
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if ip == netaddr.MustParseIP("100.64.1.2") {
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return 60000, true
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}
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return
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},
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}
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tests := []struct {
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name string
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w *Wrapper
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filter *filter.Filter
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pkt []byte
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want filter.Response
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}{
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{
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name: "reject_nil_filter",
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w: &Wrapper{
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PeerAPIPort: func(netaddr.IP) (port uint16, ok bool) {
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return 60000, true
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},
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},
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pkt: tcp4syn("1.2.3.4", "100.64.1.2", 1234, 60000),
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want: filter.Drop,
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},
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{
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name: "reject_with_filter",
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w: &Wrapper{},
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filter: filter.NewAllowNone(logger.Discard, new(netaddr.IPSet)),
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pkt: tcp4syn("1.2.3.4", "100.64.1.2", 1234, 60000),
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want: filter.Drop,
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},
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{
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name: "peerapi_bypass_filter",
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w: wrapperWithPeerAPI,
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filter: filter.NewAllowNone(logger.Discard, new(netaddr.IPSet)),
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pkt: tcp4syn("1.2.3.4", "100.64.1.2", 1234, 60000),
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want: filter.Accept,
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},
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{
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name: "peerapi_dont_bypass_filter_wrong_port",
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w: wrapperWithPeerAPI,
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filter: filter.NewAllowNone(logger.Discard, new(netaddr.IPSet)),
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pkt: tcp4syn("1.2.3.4", "100.64.1.2", 1234, 60001),
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want: filter.Drop,
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},
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{
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name: "peerapi_dont_bypass_filter_wrong_dst_ip",
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w: wrapperWithPeerAPI,
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filter: filter.NewAllowNone(logger.Discard, new(netaddr.IPSet)),
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pkt: tcp4syn("1.2.3.4", "100.64.1.3", 1234, 60000),
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want: filter.Drop,
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},
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}
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for _, tt := range tests {
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t.Run(tt.name, func(t *testing.T) {
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tt.w.SetFilter(tt.filter)
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tt.w.disableTSMPRejected = true
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if got := tt.w.filterIn(tt.pkt); got != tt.want {
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t.Errorf("got = %v; want %v", got, tt.want)
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}
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})
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}
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}
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