mirror of
https://github.com/tailscale/tailscale.git
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8f7f9ac17e
Previously, a node that was advertising a 4via6 route wouldn't be able to make use of that same route; the packet would be delivered to Tailscale, but since we weren't accepting it in handleLocalPackets, the packet wouldn't be delivered to netstack and would never hit the 4via6 logic. Let's add that support so that usage of 4via6 is consistent regardless of where the connection is initiated from. Updates #11304 Signed-off-by: Andrew Dunham <andrew@du.nham.ca> Change-Id: Ic28dc2e58080d76100d73b93360f4698605af7cb
800 lines
23 KiB
Go
800 lines
23 KiB
Go
// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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package netstack
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import (
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"context"
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"fmt"
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"maps"
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"net"
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"net/netip"
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"runtime"
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"testing"
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"time"
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"gvisor.dev/gvisor/pkg/tcpip"
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"gvisor.dev/gvisor/pkg/tcpip/header"
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"tailscale.com/envknob"
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"tailscale.com/ipn"
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"tailscale.com/ipn/ipnlocal"
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"tailscale.com/ipn/store/mem"
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"tailscale.com/metrics"
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"tailscale.com/net/packet"
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"tailscale.com/net/tsaddr"
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"tailscale.com/net/tsdial"
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"tailscale.com/net/tstun"
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"tailscale.com/tsd"
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"tailscale.com/tstest"
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"tailscale.com/types/ipproto"
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"tailscale.com/types/logid"
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"tailscale.com/wgengine"
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"tailscale.com/wgengine/filter"
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)
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// TestInjectInboundLeak tests that injectInbound doesn't leak memory.
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// See https://github.com/tailscale/tailscale/issues/3762
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func TestInjectInboundLeak(t *testing.T) {
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tunDev := tstun.NewFake()
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dialer := new(tsdial.Dialer)
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logf := func(format string, args ...any) {
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if !t.Failed() {
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t.Logf(format, args...)
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}
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}
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sys := new(tsd.System)
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eng, err := wgengine.NewUserspaceEngine(logf, wgengine.Config{
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Tun: tunDev,
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Dialer: dialer,
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SetSubsystem: sys.Set,
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HealthTracker: sys.HealthTracker(),
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})
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if err != nil {
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t.Fatal(err)
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}
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defer eng.Close()
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sys.Set(eng)
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sys.Set(new(mem.Store))
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tunWrap := sys.Tun.Get()
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lb, err := ipnlocal.NewLocalBackend(logf, logid.PublicID{}, sys, 0)
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if err != nil {
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t.Fatal(err)
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}
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ns, err := Create(logf, tunWrap, eng, sys.MagicSock.Get(), dialer, sys.DNSManager.Get(), sys.ProxyMapper(), nil)
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if err != nil {
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t.Fatal(err)
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}
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defer ns.Close()
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ns.ProcessLocalIPs = true
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if err := ns.Start(lb); err != nil {
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t.Fatalf("Start: %v", err)
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}
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ns.atomicIsLocalIPFunc.Store(func(netip.Addr) bool { return true })
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pkt := &packet.Parsed{}
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const N = 10_000
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ms0 := getMemStats()
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for range N {
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outcome := ns.injectInbound(pkt, tunWrap)
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if outcome != filter.DropSilently {
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t.Fatalf("got outcome %v; want DropSilently", outcome)
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}
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}
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ms1 := getMemStats()
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if grew := int64(ms1.HeapObjects) - int64(ms0.HeapObjects); grew >= N {
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t.Fatalf("grew by %v (which is too much and >= the %v packets we sent)", grew, N)
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}
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}
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func getMemStats() (ms runtime.MemStats) {
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runtime.GC()
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runtime.ReadMemStats(&ms)
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return
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}
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func makeNetstack(t *testing.T, config func(*Impl)) *Impl {
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tunDev := tstun.NewFake()
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sys := &tsd.System{}
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sys.Set(new(mem.Store))
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dialer := new(tsdial.Dialer)
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logf := tstest.WhileTestRunningLogger(t)
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eng, err := wgengine.NewUserspaceEngine(logf, wgengine.Config{
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Tun: tunDev,
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Dialer: dialer,
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SetSubsystem: sys.Set,
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HealthTracker: sys.HealthTracker(),
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})
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if err != nil {
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t.Fatal(err)
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}
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t.Cleanup(func() { eng.Close() })
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sys.Set(eng)
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ns, err := Create(logf, sys.Tun.Get(), eng, sys.MagicSock.Get(), dialer, sys.DNSManager.Get(), sys.ProxyMapper(), nil)
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if err != nil {
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t.Fatal(err)
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}
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t.Cleanup(func() { ns.Close() })
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lb, err := ipnlocal.NewLocalBackend(logf, logid.PublicID{}, sys, 0)
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if err != nil {
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t.Fatalf("NewLocalBackend: %v", err)
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}
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ns.atomicIsLocalIPFunc.Store(func(netip.Addr) bool { return true })
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if config != nil {
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config(ns)
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}
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if err := ns.Start(lb); err != nil {
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t.Fatalf("Start: %v", err)
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}
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return ns
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}
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func TestShouldHandlePing(t *testing.T) {
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srcIP := netip.AddrFrom4([4]byte{1, 2, 3, 4})
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t.Run("ICMP4", func(t *testing.T) {
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dst := netip.MustParseAddr("5.6.7.8")
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icmph := packet.ICMP4Header{
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IP4Header: packet.IP4Header{
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IPProto: ipproto.ICMPv4,
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Src: srcIP,
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Dst: dst,
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},
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Type: packet.ICMP4EchoRequest,
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Code: packet.ICMP4NoCode,
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}
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_, payload := packet.ICMPEchoPayload(nil)
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icmpPing := packet.Generate(icmph, payload)
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pkt := &packet.Parsed{}
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pkt.Decode(icmpPing)
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impl := makeNetstack(t, func(impl *Impl) {
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impl.ProcessSubnets = true
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})
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pingDst, ok := impl.shouldHandlePing(pkt)
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if !ok {
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t.Errorf("expected shouldHandlePing==true")
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}
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if pingDst != dst {
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t.Errorf("got dst %s; want %s", pingDst, dst)
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}
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})
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t.Run("ICMP6-no-via", func(t *testing.T) {
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dst := netip.MustParseAddr("2a09:8280:1::4169")
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icmph := packet.ICMP6Header{
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IP6Header: packet.IP6Header{
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IPProto: ipproto.ICMPv6,
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Src: srcIP,
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Dst: dst,
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},
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Type: packet.ICMP6EchoRequest,
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Code: packet.ICMP6NoCode,
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}
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_, payload := packet.ICMPEchoPayload(nil)
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icmpPing := packet.Generate(icmph, payload)
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pkt := &packet.Parsed{}
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pkt.Decode(icmpPing)
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impl := makeNetstack(t, func(impl *Impl) {
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impl.ProcessSubnets = true
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})
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pingDst, ok := impl.shouldHandlePing(pkt)
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// Expect that we handle this since it's going out onto the
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// network.
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if !ok {
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t.Errorf("expected shouldHandlePing==true")
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}
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if pingDst != dst {
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t.Errorf("got dst %s; want %s", pingDst, dst)
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}
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})
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t.Run("ICMP6-tailscale-addr", func(t *testing.T) {
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dst := netip.MustParseAddr("fd7a:115c:a1e0:ab12::1")
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icmph := packet.ICMP6Header{
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IP6Header: packet.IP6Header{
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IPProto: ipproto.ICMPv6,
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Src: srcIP,
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Dst: dst,
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},
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Type: packet.ICMP6EchoRequest,
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Code: packet.ICMP6NoCode,
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}
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_, payload := packet.ICMPEchoPayload(nil)
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icmpPing := packet.Generate(icmph, payload)
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pkt := &packet.Parsed{}
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pkt.Decode(icmpPing)
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impl := makeNetstack(t, func(impl *Impl) {
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impl.ProcessSubnets = true
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})
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_, ok := impl.shouldHandlePing(pkt)
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// We don't handle this because it's a Tailscale IP and not 4via6
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if ok {
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t.Errorf("expected shouldHandlePing==false")
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}
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})
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// Handle pings for 4via6 addresses regardless of ProcessSubnets
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for _, subnets := range []bool{true, false} {
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t.Run("ICMP6-4via6-ProcessSubnets-"+fmt.Sprint(subnets), func(t *testing.T) {
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// The 4via6 route 10.1.1.0/24 siteid 7, and then the IP
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// 10.1.1.9 within that route.
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dst := netip.MustParseAddr("fd7a:115c:a1e0:b1a:0:7:a01:109")
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expectedPingDst := netip.MustParseAddr("10.1.1.9")
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icmph := packet.ICMP6Header{
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IP6Header: packet.IP6Header{
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IPProto: ipproto.ICMPv6,
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Src: srcIP,
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Dst: dst,
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},
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Type: packet.ICMP6EchoRequest,
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Code: packet.ICMP6NoCode,
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}
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_, payload := packet.ICMPEchoPayload(nil)
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icmpPing := packet.Generate(icmph, payload)
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pkt := &packet.Parsed{}
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pkt.Decode(icmpPing)
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impl := makeNetstack(t, func(impl *Impl) {
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impl.ProcessSubnets = subnets
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})
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pingDst, ok := impl.shouldHandlePing(pkt)
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// Handled due to being 4via6
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if !ok {
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t.Errorf("expected shouldHandlePing==true")
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} else if pingDst != expectedPingDst {
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t.Errorf("got dst %s; want %s", pingDst, expectedPingDst)
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}
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})
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}
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}
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// looksLikeATailscaleSelfAddress reports whether addr looks like
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// a Tailscale self address, for tests.
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func looksLikeATailscaleSelfAddress(addr netip.Addr) bool {
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return addr.Is4() && tsaddr.IsTailscaleIP(addr) ||
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addr.Is6() && tsaddr.Tailscale4To6Range().Contains(addr)
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}
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func TestShouldProcessInbound(t *testing.T) {
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testCases := []struct {
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name string
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pkt *packet.Parsed
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afterStart func(*Impl) // optional; after Impl.Start is called
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beforeStart func(*Impl) // optional; before Impl.Start is called
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want bool
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runOnGOOS string
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}{
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{
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name: "ipv6-via",
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pkt: &packet.Parsed{
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IPVersion: 6,
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IPProto: ipproto.TCP,
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Src: netip.MustParseAddrPort("100.101.102.103:1234"),
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// $ tailscale debug via 7 10.1.1.9/24
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// fd7a:115c:a1e0:b1a:0:7:a01:109/120
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Dst: netip.MustParseAddrPort("[fd7a:115c:a1e0:b1a:0:7:a01:109]:5678"),
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TCPFlags: packet.TCPSyn,
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},
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afterStart: func(i *Impl) {
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prefs := ipn.NewPrefs()
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prefs.AdvertiseRoutes = []netip.Prefix{
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// $ tailscale debug via 7 10.1.1.0/24
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// fd7a:115c:a1e0:b1a:0:7:a01:100/120
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netip.MustParsePrefix("fd7a:115c:a1e0:b1a:0:7:a01:100/120"),
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}
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i.lb.Start(ipn.Options{
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UpdatePrefs: prefs,
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})
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i.atomicIsLocalIPFunc.Store(looksLikeATailscaleSelfAddress)
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},
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beforeStart: func(i *Impl) {
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// This should be handled even if we're
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// otherwise not processing local IPs or
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// subnets.
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i.ProcessLocalIPs = false
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i.ProcessSubnets = false
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},
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want: true,
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},
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{
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name: "ipv6-via-not-advertised",
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pkt: &packet.Parsed{
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IPVersion: 6,
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IPProto: ipproto.TCP,
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Src: netip.MustParseAddrPort("100.101.102.103:1234"),
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// $ tailscale debug via 7 10.1.1.9/24
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// fd7a:115c:a1e0:b1a:0:7:a01:109/120
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Dst: netip.MustParseAddrPort("[fd7a:115c:a1e0:b1a:0:7:a01:109]:5678"),
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TCPFlags: packet.TCPSyn,
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},
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afterStart: func(i *Impl) {
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prefs := ipn.NewPrefs()
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prefs.AdvertiseRoutes = []netip.Prefix{
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// tailscale debug via 7 10.1.2.0/24
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// fd7a:115c:a1e0:b1a:0:7:a01:200/120
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netip.MustParsePrefix("fd7a:115c:a1e0:b1a:0:7:a01:200/120"),
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}
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i.lb.Start(ipn.Options{
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UpdatePrefs: prefs,
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})
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},
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want: false,
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},
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{
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name: "tailscale-ssh-enabled",
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pkt: &packet.Parsed{
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IPVersion: 4,
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IPProto: ipproto.TCP,
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Src: netip.MustParseAddrPort("100.101.102.103:1234"),
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Dst: netip.MustParseAddrPort("100.101.102.104:22"),
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TCPFlags: packet.TCPSyn,
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},
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afterStart: func(i *Impl) {
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prefs := ipn.NewPrefs()
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prefs.RunSSH = true
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i.lb.Start(ipn.Options{
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UpdatePrefs: prefs,
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})
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i.atomicIsLocalIPFunc.Store(func(addr netip.Addr) bool {
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return addr.String() == "100.101.102.104" // Dst, above
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})
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},
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want: true,
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runOnGOOS: "linux",
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},
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{
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name: "tailscale-ssh-disabled",
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pkt: &packet.Parsed{
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IPVersion: 4,
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IPProto: ipproto.TCP,
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Src: netip.MustParseAddrPort("100.101.102.103:1234"),
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Dst: netip.MustParseAddrPort("100.101.102.104:22"),
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TCPFlags: packet.TCPSyn,
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},
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afterStart: func(i *Impl) {
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prefs := ipn.NewPrefs()
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prefs.RunSSH = false // default, but to be explicit
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i.lb.Start(ipn.Options{
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UpdatePrefs: prefs,
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})
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i.atomicIsLocalIPFunc.Store(func(addr netip.Addr) bool {
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return addr.String() == "100.101.102.104" // Dst, above
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})
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},
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want: false,
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},
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{
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name: "process-local-ips",
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pkt: &packet.Parsed{
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IPVersion: 4,
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IPProto: ipproto.TCP,
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Src: netip.MustParseAddrPort("100.101.102.103:1234"),
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Dst: netip.MustParseAddrPort("100.101.102.104:4567"),
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TCPFlags: packet.TCPSyn,
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},
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afterStart: func(i *Impl) {
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i.ProcessLocalIPs = true
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i.atomicIsLocalIPFunc.Store(func(addr netip.Addr) bool {
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return addr.String() == "100.101.102.104" // Dst, above
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})
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},
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want: true,
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},
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{
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name: "process-subnets",
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pkt: &packet.Parsed{
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IPVersion: 4,
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IPProto: ipproto.TCP,
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Src: netip.MustParseAddrPort("100.101.102.103:1234"),
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Dst: netip.MustParseAddrPort("10.1.2.3:4567"),
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TCPFlags: packet.TCPSyn,
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},
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beforeStart: func(i *Impl) {
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i.ProcessSubnets = true
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},
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afterStart: func(i *Impl) {
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// For testing purposes, assume all Tailscale
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// IPs are local; the Dst above is something
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// not in that range.
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i.atomicIsLocalIPFunc.Store(looksLikeATailscaleSelfAddress)
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},
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want: true,
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},
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{
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name: "peerapi-port-subnet-router", // see #6235
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pkt: &packet.Parsed{
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IPVersion: 4,
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IPProto: ipproto.TCP,
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Src: netip.MustParseAddrPort("100.101.102.103:1234"),
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Dst: netip.MustParseAddrPort("10.0.0.23:5555"),
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TCPFlags: packet.TCPSyn,
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},
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beforeStart: func(i *Impl) {
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// As if we were running on Linux where netstack isn't used.
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i.ProcessSubnets = false
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i.atomicIsLocalIPFunc.Store(func(netip.Addr) bool { return false })
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},
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afterStart: func(i *Impl) {
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prefs := ipn.NewPrefs()
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prefs.AdvertiseRoutes = []netip.Prefix{
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netip.MustParsePrefix("10.0.0.1/24"),
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}
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i.lb.Start(ipn.Options{
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UpdatePrefs: prefs,
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})
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// Set the PeerAPI port to the Dst port above.
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i.peerapiPort4Atomic.Store(5555)
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i.peerapiPort6Atomic.Store(5555)
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},
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want: false,
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},
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// TODO(andrew): test PeerAPI
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// TODO(andrew): test TCP packets without the SYN flag set
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}
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for _, tc := range testCases {
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t.Run(tc.name, func(t *testing.T) {
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if tc.runOnGOOS != "" && runtime.GOOS != tc.runOnGOOS {
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t.Skipf("skipping on GOOS=%v", runtime.GOOS)
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}
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impl := makeNetstack(t, tc.beforeStart)
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if tc.afterStart != nil {
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tc.afterStart(impl)
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}
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got := impl.shouldProcessInbound(tc.pkt, nil)
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if got != tc.want {
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t.Errorf("got shouldProcessInbound()=%v; want %v", got, tc.want)
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} else {
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t.Logf("OK: shouldProcessInbound() = %v", got)
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}
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})
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}
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}
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func tcp4syn(tb testing.TB, src, dst netip.Addr, sport, dport uint16) []byte {
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ip := header.IPv4(make([]byte, header.IPv4MinimumSize+header.TCPMinimumSize))
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ip.Encode(&header.IPv4Fields{
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Protocol: uint8(header.TCPProtocolNumber),
|
||
TotalLength: header.IPv4MinimumSize + header.TCPMinimumSize,
|
||
TTL: 64,
|
||
SrcAddr: tcpip.AddrFrom4Slice(src.AsSlice()),
|
||
DstAddr: tcpip.AddrFrom4Slice(dst.AsSlice()),
|
||
})
|
||
ip.SetChecksum(^ip.CalculateChecksum())
|
||
if !ip.IsChecksumValid() {
|
||
tb.Fatal("test broken; packet has incorrect IP checksum")
|
||
}
|
||
|
||
tcp := header.TCP(ip[header.IPv4MinimumSize:])
|
||
tcp.Encode(&header.TCPFields{
|
||
SrcPort: sport,
|
||
DstPort: dport,
|
||
SeqNum: 0,
|
||
DataOffset: header.TCPMinimumSize,
|
||
Flags: header.TCPFlagSyn,
|
||
WindowSize: 65535,
|
||
Checksum: 0,
|
||
})
|
||
xsum := header.PseudoHeaderChecksum(
|
||
header.TCPProtocolNumber,
|
||
tcpip.AddrFrom4Slice(src.AsSlice()),
|
||
tcpip.AddrFrom4Slice(dst.AsSlice()),
|
||
uint16(header.TCPMinimumSize),
|
||
)
|
||
tcp.SetChecksum(^tcp.CalculateChecksum(xsum))
|
||
if !tcp.IsChecksumValid(tcpip.AddrFrom4Slice(src.AsSlice()), tcpip.AddrFrom4Slice(dst.AsSlice()), 0, 0) {
|
||
tb.Fatal("test broken; packet has incorrect TCP checksum")
|
||
}
|
||
|
||
return ip
|
||
}
|
||
|
||
// makeHangDialer returns a dialer that notifies the returned channel when a
|
||
// connection is dialed and then hangs until the test finishes.
|
||
func makeHangDialer(tb testing.TB) (func(context.Context, string, string) (net.Conn, error), chan struct{}) {
|
||
done := make(chan struct{})
|
||
tb.Cleanup(func() {
|
||
close(done)
|
||
})
|
||
|
||
gotConn := make(chan struct{}, 1)
|
||
fn := func(ctx context.Context, network, address string) (net.Conn, error) {
|
||
// Signal that we have a new connection
|
||
tb.Logf("hangDialer: called with network=%q address=%q", network, address)
|
||
select {
|
||
case gotConn <- struct{}{}:
|
||
default:
|
||
}
|
||
|
||
// Hang until the test is done.
|
||
select {
|
||
case <-ctx.Done():
|
||
tb.Logf("context done")
|
||
case <-done:
|
||
tb.Logf("function completed")
|
||
}
|
||
return nil, fmt.Errorf("canceled")
|
||
}
|
||
return fn, gotConn
|
||
}
|
||
|
||
// TestTCPForwardLimits verifies that the limits on the TCP forwarder work in a
|
||
// success case (i.e. when we don't hit the limit).
|
||
func TestTCPForwardLimits(t *testing.T) {
|
||
envknob.Setenv("TS_DEBUG_NETSTACK", "true")
|
||
impl := makeNetstack(t, func(impl *Impl) {
|
||
impl.ProcessSubnets = true
|
||
})
|
||
|
||
dialFn, gotConn := makeHangDialer(t)
|
||
impl.forwardDialFunc = dialFn
|
||
|
||
prefs := ipn.NewPrefs()
|
||
prefs.AdvertiseRoutes = []netip.Prefix{
|
||
// This is the TEST-NET-1 IP block for use in documentation,
|
||
// and should never actually be routable.
|
||
netip.MustParsePrefix("192.0.2.0/24"),
|
||
}
|
||
impl.lb.Start(ipn.Options{
|
||
UpdatePrefs: prefs,
|
||
})
|
||
impl.atomicIsLocalIPFunc.Store(looksLikeATailscaleSelfAddress)
|
||
|
||
// Inject an "outbound" packet that's going to an IP address that times
|
||
// out. We need to re-parse from a byte slice so that the internal
|
||
// buffer in the packet.Parsed type is filled out.
|
||
client := netip.MustParseAddr("100.101.102.103")
|
||
destAddr := netip.MustParseAddr("192.0.2.1")
|
||
pkt := tcp4syn(t, client, destAddr, 1234, 4567)
|
||
var parsed packet.Parsed
|
||
parsed.Decode(pkt)
|
||
|
||
// When injecting this packet, we want the outcome to be "drop
|
||
// silently", which indicates that netstack is processing the
|
||
// packet and not delivering it to the host system.
|
||
if resp := impl.injectInbound(&parsed, impl.tundev); resp != filter.DropSilently {
|
||
t.Errorf("got filter outcome %v, want filter.DropSilently", resp)
|
||
}
|
||
|
||
ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
|
||
defer cancel()
|
||
|
||
// Wait until we have an in-flight outgoing connection.
|
||
select {
|
||
case <-ctx.Done():
|
||
t.Fatalf("timed out waiting for connection")
|
||
case <-gotConn:
|
||
t.Logf("got connection in progress")
|
||
}
|
||
|
||
// Inject another packet, which will be deduplicated and thus not
|
||
// increment our counter.
|
||
parsed.Decode(pkt)
|
||
if resp := impl.injectInbound(&parsed, impl.tundev); resp != filter.DropSilently {
|
||
t.Errorf("got filter outcome %v, want filter.DropSilently", resp)
|
||
}
|
||
|
||
// Verify that we now have a single in-flight address in our map.
|
||
impl.mu.Lock()
|
||
inFlight := maps.Clone(impl.connsInFlightByClient)
|
||
impl.mu.Unlock()
|
||
|
||
if got, ok := inFlight[client]; !ok || got != 1 {
|
||
t.Errorf("expected 1 in-flight connection for %v, got: %v", client, inFlight)
|
||
}
|
||
|
||
// Get the expvar statistics and verify that we're exporting the
|
||
// correct metric.
|
||
metrics := impl.ExpVar().(*metrics.Set)
|
||
|
||
const metricName = "gauge_tcp_forward_in_flight"
|
||
if v := metrics.Get(metricName).String(); v != "1" {
|
||
t.Errorf("got metric %q=%s, want 1", metricName, v)
|
||
}
|
||
}
|
||
|
||
// TestTCPForwardLimits_PerClient verifies that the per-client limit for TCP
|
||
// forwarding works.
|
||
func TestTCPForwardLimits_PerClient(t *testing.T) {
|
||
envknob.Setenv("TS_DEBUG_NETSTACK", "true")
|
||
|
||
// Set our test override limits during this test.
|
||
tstest.Replace(t, &maxInFlightConnectionAttemptsForTest, 2)
|
||
tstest.Replace(t, &maxInFlightConnectionAttemptsPerClientForTest, 1)
|
||
|
||
impl := makeNetstack(t, func(impl *Impl) {
|
||
impl.ProcessSubnets = true
|
||
})
|
||
|
||
dialFn, gotConn := makeHangDialer(t)
|
||
impl.forwardDialFunc = dialFn
|
||
|
||
prefs := ipn.NewPrefs()
|
||
prefs.AdvertiseRoutes = []netip.Prefix{
|
||
// This is the TEST-NET-1 IP block for use in documentation,
|
||
// and should never actually be routable.
|
||
netip.MustParsePrefix("192.0.2.0/24"),
|
||
}
|
||
impl.lb.Start(ipn.Options{
|
||
UpdatePrefs: prefs,
|
||
})
|
||
impl.atomicIsLocalIPFunc.Store(looksLikeATailscaleSelfAddress)
|
||
|
||
// Inject an "outbound" packet that's going to an IP address that times
|
||
// out. We need to re-parse from a byte slice so that the internal
|
||
// buffer in the packet.Parsed type is filled out.
|
||
client := netip.MustParseAddr("100.101.102.103")
|
||
destAddr := netip.MustParseAddr("192.0.2.1")
|
||
|
||
// Helpers
|
||
var port uint16 = 1234
|
||
mustInjectPacket := func() {
|
||
pkt := tcp4syn(t, client, destAddr, port, 4567)
|
||
port++ // to avoid deduplication based on endpoint
|
||
|
||
var parsed packet.Parsed
|
||
parsed.Decode(pkt)
|
||
|
||
// When injecting this packet, we want the outcome to be "drop
|
||
// silently", which indicates that netstack is processing the
|
||
// packet and not delivering it to the host system.
|
||
if resp := impl.injectInbound(&parsed, impl.tundev); resp != filter.DropSilently {
|
||
t.Fatalf("got filter outcome %v, want filter.DropSilently", resp)
|
||
}
|
||
}
|
||
|
||
ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
|
||
defer cancel()
|
||
|
||
waitPacket := func() {
|
||
select {
|
||
case <-ctx.Done():
|
||
t.Fatalf("timed out waiting for connection")
|
||
case <-gotConn:
|
||
t.Logf("got connection in progress")
|
||
}
|
||
}
|
||
|
||
// Inject the packet to start the TCP forward and wait until we have an
|
||
// in-flight outgoing connection.
|
||
mustInjectPacket()
|
||
waitPacket()
|
||
|
||
// Verify that we now have a single in-flight address in our map.
|
||
impl.mu.Lock()
|
||
inFlight := maps.Clone(impl.connsInFlightByClient)
|
||
impl.mu.Unlock()
|
||
|
||
if got, ok := inFlight[client]; !ok || got != 1 {
|
||
t.Errorf("expected 1 in-flight connection for %v, got: %v", client, inFlight)
|
||
}
|
||
|
||
metrics := impl.ExpVar().(*metrics.Set)
|
||
|
||
// One client should have reached the limit at this point.
|
||
if v := metrics.Get("gauge_tcp_forward_in_flight_per_client_limit_reached").String(); v != "1" {
|
||
t.Errorf("got limit reached expvar metric=%s, want 1", v)
|
||
}
|
||
|
||
// Inject another packet, and verify that we've incremented our
|
||
// "dropped" metrics since this will have been dropped.
|
||
mustInjectPacket()
|
||
|
||
// expvar metric
|
||
const metricName = "counter_tcp_forward_max_in_flight_per_client_drop"
|
||
if v := metrics.Get(metricName).String(); v != "1" {
|
||
t.Errorf("got expvar metric %q=%s, want 1", metricName, v)
|
||
}
|
||
|
||
// client metric
|
||
if v := metricPerClientForwardLimit.Value(); v != 1 {
|
||
t.Errorf("got clientmetric limit metric=%d, want 1", v)
|
||
}
|
||
}
|
||
|
||
// TestHandleLocalPackets tests the handleLocalPackets function, ensuring that
|
||
// we are properly deciding to handle packets that are destined for "local"
|
||
// IPs–addresses that are either for this node, or that it is responsible for.
|
||
//
|
||
// See, e.g. #11304
|
||
func TestHandleLocalPackets(t *testing.T) {
|
||
var (
|
||
selfIP4 = netip.MustParseAddr("100.64.1.2")
|
||
selfIP6 = netip.MustParseAddr("fd7a:115c:a1e0::123")
|
||
)
|
||
|
||
impl := makeNetstack(t, func(impl *Impl) {
|
||
impl.ProcessSubnets = false
|
||
impl.ProcessLocalIPs = false
|
||
impl.atomicIsLocalIPFunc.Store(func(addr netip.Addr) bool {
|
||
return addr == selfIP4 || addr == selfIP6
|
||
})
|
||
})
|
||
|
||
prefs := ipn.NewPrefs()
|
||
prefs.AdvertiseRoutes = []netip.Prefix{
|
||
// $ tailscale debug via 7 10.1.1.0/24
|
||
// fd7a:115c:a1e0:b1a:0:7:a01:100/120
|
||
netip.MustParsePrefix("fd7a:115c:a1e0:b1a:0:7:a01:100/120"),
|
||
}
|
||
_, err := impl.lb.EditPrefs(&ipn.MaskedPrefs{
|
||
Prefs: *prefs,
|
||
AdvertiseRoutesSet: true,
|
||
})
|
||
if err != nil {
|
||
t.Fatalf("EditPrefs: %v", err)
|
||
}
|
||
|
||
t.Run("ShouldHandleServiceIP", func(t *testing.T) {
|
||
pkt := &packet.Parsed{
|
||
IPVersion: 4,
|
||
IPProto: ipproto.TCP,
|
||
Src: netip.MustParseAddrPort("127.0.0.1:9999"),
|
||
Dst: netip.MustParseAddrPort("100.100.100.100:53"),
|
||
TCPFlags: packet.TCPSyn,
|
||
}
|
||
resp := impl.handleLocalPackets(pkt, impl.tundev)
|
||
if resp != filter.DropSilently {
|
||
t.Errorf("got filter outcome %v, want filter.DropSilently", resp)
|
||
}
|
||
})
|
||
t.Run("ShouldHandle4via6", func(t *testing.T) {
|
||
pkt := &packet.Parsed{
|
||
IPVersion: 6,
|
||
IPProto: ipproto.TCP,
|
||
Src: netip.MustParseAddrPort("[::1]:1234"),
|
||
|
||
// This is an IP in the above 4via6 subnet that this node handles.
|
||
// $ tailscale debug via 7 10.1.1.9/24
|
||
// fd7a:115c:a1e0:b1a:0:7:a01:109/120
|
||
Dst: netip.MustParseAddrPort("[fd7a:115c:a1e0:b1a:0:7:a01:109]:5678"),
|
||
TCPFlags: packet.TCPSyn,
|
||
}
|
||
resp := impl.handleLocalPackets(pkt, impl.tundev)
|
||
|
||
// DropSilently is the outcome we expected, since we actually
|
||
// handled this packet by injecting it into netstack, which
|
||
// will handle creating the TCP forwarder. We drop it so we
|
||
// don't process the packet outside of netstack.
|
||
if resp != filter.DropSilently {
|
||
t.Errorf("got filter outcome %v, want filter.DropSilently", resp)
|
||
}
|
||
})
|
||
t.Run("OtherNonHandled", func(t *testing.T) {
|
||
pkt := &packet.Parsed{
|
||
IPVersion: 6,
|
||
IPProto: ipproto.TCP,
|
||
Src: netip.MustParseAddrPort("[::1]:1234"),
|
||
|
||
// This IP is *not* in the above 4via6 route
|
||
// $ tailscale debug via 99 10.1.1.9/24
|
||
// fd7a:115c:a1e0:b1a:0:63:a01:109/120
|
||
Dst: netip.MustParseAddrPort("[fd7a:115c:a1e0:b1a:0:63:a01:109]:5678"),
|
||
TCPFlags: packet.TCPSyn,
|
||
}
|
||
resp := impl.handleLocalPackets(pkt, impl.tundev)
|
||
|
||
// Accept means that handleLocalPackets does not handle this
|
||
// packet, we "accept" it to continue further processing,
|
||
// instead of dropping because it was already handled.
|
||
if resp != filter.Accept {
|
||
t.Errorf("got filter outcome %v, want filter.Accept", resp)
|
||
}
|
||
})
|
||
}
|