Files
tailscale/wgengine/router/osrouter/router_linux_test.go
T
Fernando Serboncini c355618e73 wgengine/router/osrouter: skip netfilter add-ons when chain setup fails (#19757)
linuxRouter has two blocks (connmark rules and the CGNAT drop rule) that
gate on cfg.NetfilterMode, the requested config state. This may cause an
error when setNetfilterModeLocked fails, since it may keep assuming this
config is valid.

We now gate both blocks on r.netfilterMode, matching the pattern used by
SNAT, stateful, and loopback paths.

Fixes #19737

Change-Id: Ia6003a082db99c376e662132d725661afbac0ee9

Signed-off-by: Fernando Serboncini <fserb@tailscale.com>
2026-05-15 09:32:30 -04:00

1612 lines
52 KiB
Go

// Copyright (c) Tailscale Inc & contributors
// SPDX-License-Identifier: BSD-3-Clause
package osrouter
import (
"errors"
"fmt"
"math/rand"
"net/netip"
"os"
"reflect"
"regexp"
"slices"
"sort"
"strings"
"sync"
"sync/atomic"
"testing"
"github.com/google/go-cmp/cmp"
"github.com/tailscale/netlink"
"github.com/tailscale/wireguard-go/tun"
"go4.org/netipx"
"tailscale.com/health"
"tailscale.com/net/netmon"
"tailscale.com/net/tsaddr"
"tailscale.com/tsconst"
"tailscale.com/tstest"
"tailscale.com/types/logger"
"tailscale.com/util/eventbus"
"tailscale.com/util/eventbus/eventbustest"
"tailscale.com/util/linuxfw"
"tailscale.com/version/distro"
"tailscale.com/wgengine/router"
)
type Config = router.Config
func TestRouterStates(t *testing.T) {
basic := `
ip rule add -4 pref 5210 fwmark 0x80000/0xff0000 table main
ip rule add -4 pref 5230 fwmark 0x80000/0xff0000 table default
ip rule add -4 pref 5250 fwmark 0x80000/0xff0000 type unreachable
ip rule add -4 pref 5270 table 52
ip rule add -6 pref 5210 fwmark 0x80000/0xff0000 table main
ip rule add -6 pref 5230 fwmark 0x80000/0xff0000 table default
ip rule add -6 pref 5250 fwmark 0x80000/0xff0000 type unreachable
ip rule add -6 pref 5270 table 52
`
states := []struct {
name string
in *Config
want string
}{
{
name: "no-config",
in: nil,
want: `
up` + basic,
},
{
name: "local-addr-only",
in: &Config{
LocalAddrs: mustCIDRs("100.101.102.103/10"),
NetfilterMode: netfilterOff,
},
want: `
up
ip addr add 100.101.102.103/10 dev tailscale0` + basic,
},
{
name: "addr-and-routes",
in: &Config{
LocalAddrs: mustCIDRs("100.101.102.103/10"),
Routes: mustCIDRs("100.100.100.100/32", "192.168.16.0/24"),
NetfilterMode: netfilterOff,
},
want: `
up
ip addr add 100.101.102.103/10 dev tailscale0
ip route add 100.100.100.100/32 dev tailscale0 table 52
ip route add 192.168.16.0/24 dev tailscale0 table 52` + basic,
},
{
name: "addr-routes-and-subnet-routes",
in: &Config{
LocalAddrs: mustCIDRs("100.101.102.103/10"),
Routes: mustCIDRs("100.100.100.100/32", "192.168.16.0/24"),
SubnetRoutes: mustCIDRs("200.0.0.0/8"),
NetfilterMode: netfilterOff,
},
want: `
up
ip addr add 100.101.102.103/10 dev tailscale0
ip route add 100.100.100.100/32 dev tailscale0 table 52
ip route add 192.168.16.0/24 dev tailscale0 table 52` + basic,
},
{
name: "addr-routes-subnet-routes-with-netfilter",
in: &Config{
LocalAddrs: mustCIDRs("100.101.102.104/10"),
Routes: mustCIDRs("100.100.100.100/32", "10.0.0.0/8"),
SubnetRoutes: mustCIDRs("200.0.0.0/8"),
SNATSubnetRoutes: true,
StatefulFiltering: true,
NetfilterMode: netfilterOn,
},
want: `
up
ip addr add 100.101.102.104/10 dev tailscale0
ip route add 10.0.0.0/8 dev tailscale0 table 52
ip route add 100.100.100.100/32 dev tailscale0 table 52` + basic +
`v4/filter/FORWARD -j ts-forward
v4/filter/INPUT -j ts-input
v4/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v4/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v4/filter/ts-forward -o tailscale0 -s 100.64.0.0/10 -j DROP
v4/filter/ts-forward -o tailscale0 -m conntrack ! --ctstate ESTABLISHED,RELATED -j DROP
v4/filter/ts-forward -o tailscale0 -j ACCEPT
v4/filter/ts-input -i lo -s 100.101.102.104 -j ACCEPT
v4/filter/ts-input ! -i tailscale0 -s 100.115.92.0/23 -j RETURN
v4/filter/ts-input ! -i tailscale0 -s 100.64.0.0/10 -j DROP
v4/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/nat/POSTROUTING -j ts-postrouting
v4/nat/ts-postrouting -m mark --mark 0x40000/0xff0000 -j MASQUERADE
v6/filter/FORWARD -j ts-forward
v6/filter/INPUT -j ts-input
v6/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v6/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v6/filter/ts-forward -o tailscale0 -m conntrack ! --ctstate ESTABLISHED,RELATED -j DROP
v6/filter/ts-forward -o tailscale0 -j ACCEPT
v6/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/nat/POSTROUTING -j ts-postrouting
v6/nat/ts-postrouting -m mark --mark 0x40000/0xff0000 -j MASQUERADE
`,
},
{
name: "addr-routes-subnet-routes-netfilter-no-stateful",
in: &Config{
LocalAddrs: mustCIDRs("100.101.102.104/10"),
Routes: mustCIDRs("100.100.100.100/32", "10.0.0.0/8"),
SubnetRoutes: mustCIDRs("200.0.0.0/8"),
SNATSubnetRoutes: true,
StatefulFiltering: false,
NetfilterMode: netfilterOn,
},
want: `
up
ip addr add 100.101.102.104/10 dev tailscale0
ip route add 10.0.0.0/8 dev tailscale0 table 52
ip route add 100.100.100.100/32 dev tailscale0 table 52` + basic +
`v4/filter/FORWARD -j ts-forward
v4/filter/INPUT -j ts-input
v4/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v4/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v4/filter/ts-forward -o tailscale0 -s 100.64.0.0/10 -j DROP
v4/filter/ts-forward -o tailscale0 -j ACCEPT
v4/filter/ts-input -i lo -s 100.101.102.104 -j ACCEPT
v4/filter/ts-input ! -i tailscale0 -s 100.115.92.0/23 -j RETURN
v4/filter/ts-input ! -i tailscale0 -s 100.64.0.0/10 -j DROP
v4/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/nat/POSTROUTING -j ts-postrouting
v4/nat/ts-postrouting -m mark --mark 0x40000/0xff0000 -j MASQUERADE
v6/filter/FORWARD -j ts-forward
v6/filter/INPUT -j ts-input
v6/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v6/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v6/filter/ts-forward -o tailscale0 -j ACCEPT
v6/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/nat/POSTROUTING -j ts-postrouting
v6/nat/ts-postrouting -m mark --mark 0x40000/0xff0000 -j MASQUERADE
`,
},
{
name: "addr-and-routes-with-netfilter",
in: &Config{
LocalAddrs: mustCIDRs("100.101.102.104/10"),
Routes: mustCIDRs("100.100.100.100/32", "10.0.0.0/8"),
NetfilterMode: netfilterOn,
},
want: `
up
ip addr add 100.101.102.104/10 dev tailscale0
ip route add 10.0.0.0/8 dev tailscale0 table 52
ip route add 100.100.100.100/32 dev tailscale0 table 52` + basic +
`v4/filter/FORWARD -j ts-forward
v4/filter/INPUT -j ts-input
v4/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v4/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v4/filter/ts-forward -o tailscale0 -s 100.64.0.0/10 -j DROP
v4/filter/ts-forward -o tailscale0 -j ACCEPT
v4/filter/ts-input -i lo -s 100.101.102.104 -j ACCEPT
v4/filter/ts-input ! -i tailscale0 -s 100.115.92.0/23 -j RETURN
v4/filter/ts-input ! -i tailscale0 -s 100.64.0.0/10 -j DROP
v4/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/nat/POSTROUTING -j ts-postrouting
v6/filter/FORWARD -j ts-forward
v6/filter/INPUT -j ts-input
v6/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v6/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v6/filter/ts-forward -o tailscale0 -j ACCEPT
v6/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/nat/POSTROUTING -j ts-postrouting
`,
},
{
name: "addr-routes-subnet-routes-netfilter-no-SNAT",
in: &Config{
LocalAddrs: mustCIDRs("100.101.102.104/10"),
Routes: mustCIDRs("100.100.100.100/32", "10.0.0.0/8"),
SubnetRoutes: mustCIDRs("200.0.0.0/8"),
SNATSubnetRoutes: false,
NetfilterMode: netfilterOn,
},
want: `
up
ip addr add 100.101.102.104/10 dev tailscale0
ip route add 10.0.0.0/8 dev tailscale0 table 52
ip route add 100.100.100.100/32 dev tailscale0 table 52` + basic +
`v4/filter/FORWARD -j ts-forward
v4/filter/INPUT -j ts-input
v4/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v4/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v4/filter/ts-forward -o tailscale0 -s 100.64.0.0/10 -j DROP
v4/filter/ts-forward -o tailscale0 -j ACCEPT
v4/filter/ts-input -i lo -s 100.101.102.104 -j ACCEPT
v4/filter/ts-input ! -i tailscale0 -s 100.115.92.0/23 -j RETURN
v4/filter/ts-input ! -i tailscale0 -s 100.64.0.0/10 -j DROP
v4/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/nat/POSTROUTING -j ts-postrouting
v6/filter/FORWARD -j ts-forward
v6/filter/INPUT -j ts-input
v6/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v6/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v6/filter/ts-forward -o tailscale0 -j ACCEPT
v6/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/nat/POSTROUTING -j ts-postrouting
`,
},
{
name: "addr-and-routes-with-netfilter-2",
in: &Config{
LocalAddrs: mustCIDRs("100.101.102.104/10"),
Routes: mustCIDRs("100.100.100.100/32", "10.0.0.0/8"),
NetfilterMode: netfilterOn,
},
want: `
up
ip addr add 100.101.102.104/10 dev tailscale0
ip route add 10.0.0.0/8 dev tailscale0 table 52
ip route add 100.100.100.100/32 dev tailscale0 table 52` + basic +
`v4/filter/FORWARD -j ts-forward
v4/filter/INPUT -j ts-input
v4/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v4/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v4/filter/ts-forward -o tailscale0 -s 100.64.0.0/10 -j DROP
v4/filter/ts-forward -o tailscale0 -j ACCEPT
v4/filter/ts-input -i lo -s 100.101.102.104 -j ACCEPT
v4/filter/ts-input ! -i tailscale0 -s 100.115.92.0/23 -j RETURN
v4/filter/ts-input ! -i tailscale0 -s 100.64.0.0/10 -j DROP
v4/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/nat/POSTROUTING -j ts-postrouting
v6/filter/FORWARD -j ts-forward
v6/filter/INPUT -j ts-input
v6/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v6/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v6/filter/ts-forward -o tailscale0 -j ACCEPT
v6/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/nat/POSTROUTING -j ts-postrouting
`,
},
{
name: "addr-and-routes-with-half-netfilter",
in: &Config{
LocalAddrs: mustCIDRs("100.101.102.104/10"),
Routes: mustCIDRs("100.100.100.100/32", "10.0.0.0/8"),
NetfilterMode: netfilterNoDivert,
},
want: `
up
ip addr add 100.101.102.104/10 dev tailscale0
ip route add 10.0.0.0/8 dev tailscale0 table 52
ip route add 100.100.100.100/32 dev tailscale0 table 52` + basic +
`v4/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v4/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v4/filter/ts-forward -o tailscale0 -s 100.64.0.0/10 -j DROP
v4/filter/ts-forward -o tailscale0 -j ACCEPT
v4/filter/ts-input -i lo -s 100.101.102.104 -j ACCEPT
v4/filter/ts-input ! -i tailscale0 -s 100.115.92.0/23 -j RETURN
v4/filter/ts-input ! -i tailscale0 -s 100.64.0.0/10 -j DROP
v6/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v6/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v6/filter/ts-forward -o tailscale0 -j ACCEPT
`,
},
{
name: "addr-and-routes-with-netfilter2",
in: &Config{
LocalAddrs: mustCIDRs("100.101.102.104/10"),
Routes: mustCIDRs("100.100.100.100/32", "10.0.0.0/8"),
NetfilterMode: netfilterOn,
},
want: `
up
ip addr add 100.101.102.104/10 dev tailscale0
ip route add 10.0.0.0/8 dev tailscale0 table 52
ip route add 100.100.100.100/32 dev tailscale0 table 52` + basic +
`v4/filter/FORWARD -j ts-forward
v4/filter/INPUT -j ts-input
v4/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v4/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v4/filter/ts-forward -o tailscale0 -s 100.64.0.0/10 -j DROP
v4/filter/ts-forward -o tailscale0 -j ACCEPT
v4/filter/ts-input -i lo -s 100.101.102.104 -j ACCEPT
v4/filter/ts-input ! -i tailscale0 -s 100.115.92.0/23 -j RETURN
v4/filter/ts-input ! -i tailscale0 -s 100.64.0.0/10 -j DROP
v4/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/nat/POSTROUTING -j ts-postrouting
v6/filter/FORWARD -j ts-forward
v6/filter/INPUT -j ts-input
v6/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v6/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v6/filter/ts-forward -o tailscale0 -j ACCEPT
v6/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/nat/POSTROUTING -j ts-postrouting
`,
},
{
name: "addr-routes-local-routes-with-netfilter",
in: &Config{
LocalAddrs: mustCIDRs("100.101.102.104/10"),
Routes: mustCIDRs("100.100.100.100/32", "0.0.0.0/0"),
LocalRoutes: mustCIDRs("10.0.0.0/8"),
NetfilterMode: netfilterOn,
},
want: `
up
ip addr add 100.101.102.104/10 dev tailscale0
ip route add 0.0.0.0/0 dev tailscale0 table 52
ip route add 100.100.100.100/32 dev tailscale0 table 52
ip route add throw 10.0.0.0/8 table 52` + basic +
`v4/filter/FORWARD -j ts-forward
v4/filter/INPUT -j ts-input
v4/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v4/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v4/filter/ts-forward -o tailscale0 -s 100.64.0.0/10 -j DROP
v4/filter/ts-forward -o tailscale0 -j ACCEPT
v4/filter/ts-input -i lo -s 100.101.102.104 -j ACCEPT
v4/filter/ts-input ! -i tailscale0 -s 100.115.92.0/23 -j RETURN
v4/filter/ts-input ! -i tailscale0 -s 100.64.0.0/10 -j DROP
v4/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/nat/POSTROUTING -j ts-postrouting
v6/filter/FORWARD -j ts-forward
v6/filter/INPUT -j ts-input
v6/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v6/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v6/filter/ts-forward -o tailscale0 -j ACCEPT
v6/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/nat/POSTROUTING -j ts-postrouting
`,
},
{
name: "addr-routes-local-routes-no-netfilter",
in: &Config{
LocalAddrs: mustCIDRs("100.101.102.104/10"),
Routes: mustCIDRs("100.100.100.100/32", "0.0.0.0/0"),
LocalRoutes: mustCIDRs("10.0.0.0/8", "192.168.0.0/24"),
NetfilterMode: netfilterOff,
},
want: `
up
ip addr add 100.101.102.104/10 dev tailscale0
ip route add 0.0.0.0/0 dev tailscale0 table 52
ip route add 100.100.100.100/32 dev tailscale0 table 52
ip route add throw 10.0.0.0/8 table 52
ip route add throw 192.168.0.0/24 table 52` + basic,
},
{
name: "subnet-routes-connmark-for-rp_filter",
in: &Config{
LocalAddrs: mustCIDRs("100.101.102.104/10"),
Routes: mustCIDRs("100.100.100.100/32"),
SubnetRoutes: mustCIDRs("10.0.0.0/16"),
SNATSubnetRoutes: true,
NetfilterMode: netfilterOn,
},
want: `
up
ip addr add 100.101.102.104/10 dev tailscale0
ip route add 100.100.100.100/32 dev tailscale0 table 52` + basic +
`v4/filter/FORWARD -j ts-forward
v4/filter/INPUT -j ts-input
v4/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v4/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v4/filter/ts-forward -o tailscale0 -s 100.64.0.0/10 -j DROP
v4/filter/ts-forward -o tailscale0 -j ACCEPT
v4/filter/ts-input -i lo -s 100.101.102.104 -j ACCEPT
v4/filter/ts-input ! -i tailscale0 -s 100.115.92.0/23 -j RETURN
v4/filter/ts-input ! -i tailscale0 -s 100.64.0.0/10 -j DROP
v4/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/nat/POSTROUTING -j ts-postrouting
v4/nat/ts-postrouting -m mark --mark 0x40000/0xff0000 -j MASQUERADE
v6/filter/FORWARD -j ts-forward
v6/filter/INPUT -j ts-input
v6/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v6/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v6/filter/ts-forward -o tailscale0 -j ACCEPT
v6/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/nat/POSTROUTING -j ts-postrouting
v6/nat/ts-postrouting -m mark --mark 0x40000/0xff0000 -j MASQUERADE
`,
},
{
name: "subnet-routes-connmark-always-enabled",
in: &Config{
LocalAddrs: mustCIDRs("100.101.102.104/10"),
Routes: mustCIDRs("100.100.100.100/32"),
SubnetRoutes: mustCIDRs("10.0.0.0/16"),
SNATSubnetRoutes: true,
NetfilterMode: netfilterOn,
},
want: `
up
ip addr add 100.101.102.104/10 dev tailscale0
ip route add 100.100.100.100/32 dev tailscale0 table 52` + basic +
`v4/filter/FORWARD -j ts-forward
v4/filter/INPUT -j ts-input
v4/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v4/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v4/filter/ts-forward -o tailscale0 -s 100.64.0.0/10 -j DROP
v4/filter/ts-forward -o tailscale0 -j ACCEPT
v4/filter/ts-input -i lo -s 100.101.102.104 -j ACCEPT
v4/filter/ts-input ! -i tailscale0 -s 100.115.92.0/23 -j RETURN
v4/filter/ts-input ! -i tailscale0 -s 100.64.0.0/10 -j DROP
v4/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/nat/POSTROUTING -j ts-postrouting
v4/nat/ts-postrouting -m mark --mark 0x40000/0xff0000 -j MASQUERADE
v6/filter/FORWARD -j ts-forward
v6/filter/INPUT -j ts-input
v6/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v6/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v6/filter/ts-forward -o tailscale0 -j ACCEPT
v6/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/nat/POSTROUTING -j ts-postrouting
v6/nat/ts-postrouting -m mark --mark 0x40000/0xff0000 -j MASQUERADE
`,
},
{
name: "connmark-with-stateful-filtering",
in: &Config{
LocalAddrs: mustCIDRs("100.101.102.104/10"),
Routes: mustCIDRs("100.100.100.100/32"),
SubnetRoutes: mustCIDRs("10.0.0.0/16"),
SNATSubnetRoutes: true,
StatefulFiltering: true,
NetfilterMode: netfilterOn,
},
want: `
up
ip addr add 100.101.102.104/10 dev tailscale0
ip route add 100.100.100.100/32 dev tailscale0 table 52` + basic +
`v4/filter/FORWARD -j ts-forward
v4/filter/INPUT -j ts-input
v4/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v4/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v4/filter/ts-forward -o tailscale0 -s 100.64.0.0/10 -j DROP
v4/filter/ts-forward -o tailscale0 -m conntrack ! --ctstate ESTABLISHED,RELATED -j DROP
v4/filter/ts-forward -o tailscale0 -j ACCEPT
v4/filter/ts-input -i lo -s 100.101.102.104 -j ACCEPT
v4/filter/ts-input ! -i tailscale0 -s 100.115.92.0/23 -j RETURN
v4/filter/ts-input ! -i tailscale0 -s 100.64.0.0/10 -j DROP
v4/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v4/nat/POSTROUTING -j ts-postrouting
v4/nat/ts-postrouting -m mark --mark 0x40000/0xff0000 -j MASQUERADE
v6/filter/FORWARD -j ts-forward
v6/filter/INPUT -j ts-input
v6/filter/ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000
v6/filter/ts-forward -m mark --mark 0x40000/0xff0000 -j ACCEPT
v6/filter/ts-forward -o tailscale0 -m conntrack ! --ctstate ESTABLISHED,RELATED -j DROP
v6/filter/ts-forward -o tailscale0 -j ACCEPT
v6/mangle/OUTPUT -m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/mangle/PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000
v6/nat/POSTROUTING -j ts-postrouting
v6/nat/ts-postrouting -m mark --mark 0x40000/0xff0000 -j MASQUERADE
`,
},
}
bus := eventbus.New()
defer bus.Close()
mon, err := netmon.New(bus, logger.Discard)
if err != nil {
t.Fatal(err)
}
mon.Start()
defer mon.Close()
fake := NewFakeOS(t)
ht := health.NewTracker(bus)
router, err := newUserspaceRouterAdvanced(t.Logf, "tailscale0", mon, fake, ht, bus)
router.(*linuxRouter).nfr = fake.nfr
if err != nil {
t.Fatalf("failed to create router: %v", err)
}
if err := router.Up(); err != nil {
t.Fatalf("failed to up router: %v", err)
}
testState := func(t *testing.T, i int) {
t.Helper()
if err := router.Set(states[i].in); err != nil {
t.Fatalf("failed to set router config: %v", err)
}
got := fake.String()
want := adjustFwmask(t, strings.TrimSpace(states[i].want))
if diff := cmp.Diff(got, want); diff != "" {
t.Fatalf("unexpected OS state (-got+want):\n%s", diff)
}
}
for i, state := range states {
t.Run(state.name, func(t *testing.T) { testState(t, i) })
}
// Cycle through a bunch of states in pseudorandom order, to
// verify that we transition cleanly from state to state no matter
// the order.
for randRun := 0; randRun < 5*len(states); randRun++ {
i := rand.Intn(len(states))
state := states[i]
t.Run(state.name, func(t *testing.T) { testState(t, i) })
}
}
type fakeIPTablesRunner struct {
t *testing.T
ipt4 map[string][]string
ipt6 map[string][]string
// we always assume ipv6 and ipv6 nat are enabled when testing
addChainsErr error // if non-nil, AddChains returns it instead of setting up chains
addConnmarkSaveCalls int
addExternalCGNATCalls int
}
func newIPTablesRunner(t *testing.T) linuxfw.NetfilterRunner {
return &fakeIPTablesRunner{
t: t,
ipt4: map[string][]string{
"filter/INPUT": nil,
"filter/OUTPUT": nil,
"filter/FORWARD": nil,
"nat/PREROUTING": nil,
"nat/OUTPUT": nil,
"nat/POSTROUTING": nil,
"mangle/PREROUTING": nil,
"mangle/OUTPUT": nil,
},
ipt6: map[string][]string{
"filter/INPUT": nil,
"filter/OUTPUT": nil,
"filter/FORWARD": nil,
"nat/PREROUTING": nil,
"nat/OUTPUT": nil,
"nat/POSTROUTING": nil,
"mangle/PREROUTING": nil,
"mangle/OUTPUT": nil,
},
}
}
func insertRule(n *fakeIPTablesRunner, curIPT map[string][]string, chain, newRule string) error {
// Get current rules for filter/ts-input chain with according IP version
curTSInputRules, ok := curIPT[chain]
if !ok {
n.t.Fatalf("no %s chain exists", chain)
return fmt.Errorf("no %s chain exists", chain)
}
// Add new rule to top of filter/ts-input
curTSInputRules = append(curTSInputRules, "")
copy(curTSInputRules[1:], curTSInputRules)
curTSInputRules[0] = newRule
curIPT[chain] = curTSInputRules
return nil
}
func insertRuleAt(n *fakeIPTablesRunner, curIPT map[string][]string, chain string, pos int, newRule string) {
rules, ok := curIPT[chain]
if !ok {
n.t.Fatalf("no %s chain exists", chain)
}
// If the given position is after the end of the chain, error.
if pos > len(rules) {
n.t.Fatalf("position %d > len(chain %s) %d", pos, chain, len(chain))
}
// Insert the rule at the given position
rules = slices.Insert(rules, pos, newRule)
curIPT[chain] = rules
}
func appendRule(n *fakeIPTablesRunner, curIPT map[string][]string, chain, newRule string) error {
// Get current rules for filter/ts-input chain with according IP version
curTSInputRules, ok := curIPT[chain]
if !ok {
n.t.Fatalf("no %s chain exists", chain)
return fmt.Errorf("no %s chain exists", chain)
}
// Add new rule to end of filter/ts-input
curTSInputRules = append(curTSInputRules, newRule)
curIPT[chain] = curTSInputRules
return nil
}
func deleteRule(n *fakeIPTablesRunner, curIPT map[string][]string, chain, delRule string) error {
// Get current rules for filter/ts-input chain with according IP version
curTSInputRules, ok := curIPT[chain]
if !ok {
n.t.Fatalf("no %s chain exists", chain)
return fmt.Errorf("no %s chain exists", chain)
}
// Remove rule from filter/ts-input
for i, rule := range curTSInputRules {
if rule == delRule {
curTSInputRules = append(curTSInputRules[:i], curTSInputRules[i+1:]...)
break
}
}
curIPT[chain] = curTSInputRules
return nil
}
func (n *fakeIPTablesRunner) AddLoopbackRule(addr netip.Addr) error {
curIPT := n.ipt4
if addr.Is6() {
curIPT = n.ipt6
}
newRule := fmt.Sprintf("-i lo -s %s -j ACCEPT", addr.String())
return insertRule(n, curIPT, "filter/ts-input", newRule)
}
func (n *fakeIPTablesRunner) AddBase(tunname string) error {
if err := n.addBase4(tunname); err != nil {
return err
}
if n.HasIPV6() {
if err := n.addBase6(tunname); err != nil {
return err
}
}
return nil
}
func (n *fakeIPTablesRunner) AddDNATRule(origDst, dst netip.Addr) error {
return errors.New("not implemented")
}
func (n *fakeIPTablesRunner) DNATWithLoadBalancer(netip.Addr, []netip.Addr) error {
return errors.New("not implemented")
}
func (n *fakeIPTablesRunner) EnsureSNATForDst(src, dst netip.Addr) error {
return errors.New("not implemented")
}
func (n *fakeIPTablesRunner) DNATNonTailscaleTraffic(exemptInterface string, dst netip.Addr) error {
return errors.New("not implemented")
}
func (n *fakeIPTablesRunner) EnsurePortMapRuleForSvc(svc, tun string, targetIP netip.Addr, pm linuxfw.PortMap) error {
return errors.New("not implemented")
}
func (n *fakeIPTablesRunner) DeletePortMapRuleForSvc(svc, tun string, targetIP netip.Addr, pm linuxfw.PortMap) error {
return errors.New("not implemented")
}
func (n *fakeIPTablesRunner) DeleteSvc(svc, tun string, targetIPs []netip.Addr, pm []linuxfw.PortMap) error {
return errors.New("not implemented")
}
func (n *fakeIPTablesRunner) ClampMSSToPMTU(tun string, addr netip.Addr) error {
return errors.New("not implemented")
}
func (n *fakeIPTablesRunner) EnsureDNATRuleForSvc(svcName string, origDst, dst netip.Addr) error {
return errors.New("not implemented")
}
func (n *fakeIPTablesRunner) DeleteDNATRuleForSvc(svcName string, origDst, dst netip.Addr) error {
return errors.New("not implemented")
}
type iptRule struct{ chain, rule string }
func (n *fakeIPTablesRunner) addBase4(tunname string) error {
curIPT := n.ipt4
newRules := []iptRule{
{"filter/ts-forward", fmt.Sprintf("-i %s -j MARK --set-mark %s/%s", tunname, tsconst.LinuxSubnetRouteMark, tsconst.LinuxFwmarkMask)},
{"filter/ts-forward", fmt.Sprintf("-m mark --mark %s/%s -j ACCEPT", tsconst.LinuxSubnetRouteMark, tsconst.LinuxFwmarkMask)},
{"filter/ts-forward", fmt.Sprintf("-o %s -s %s -j DROP", tunname, tsaddr.CGNATRange().String())},
{"filter/ts-forward", fmt.Sprintf("-o %s -j ACCEPT", tunname)},
}
for _, rule := range newRules {
if err := appendRule(n, curIPT, rule.chain, rule.rule); err != nil {
return fmt.Errorf("add rule %q to chain %q: %w", rule.rule, rule.chain, err)
}
}
return nil
}
func (n *fakeIPTablesRunner) addBase6(tunname string) error {
curIPT := n.ipt6
newRules := []iptRule{
{"filter/ts-forward", fmt.Sprintf("-i %s -j MARK --set-mark %s/%s", tunname, tsconst.LinuxSubnetRouteMark, tsconst.LinuxFwmarkMask)},
{"filter/ts-forward", fmt.Sprintf("-m mark --mark %s/%s -j ACCEPT", tsconst.LinuxSubnetRouteMark, tsconst.LinuxFwmarkMask)},
{"filter/ts-forward", fmt.Sprintf("-o %s -j ACCEPT", tunname)},
}
for _, rule := range newRules {
if err := appendRule(n, curIPT, rule.chain, rule.rule); err != nil {
return fmt.Errorf("add rule %q to chain %q: %w", rule.rule, rule.chain, err)
}
}
return nil
}
func (n *fakeIPTablesRunner) DelLoopbackRule(addr netip.Addr) error {
curIPT := n.ipt4
if addr.Is6() {
curIPT = n.ipt6
}
delRule := fmt.Sprintf("-i lo -s %s -j ACCEPT", addr.String())
return deleteRule(n, curIPT, "filter/ts-input", delRule)
}
func (n *fakeIPTablesRunner) AddHooks() error {
newRules := []iptRule{
{"filter/INPUT", "-j ts-input"},
{"filter/FORWARD", "-j ts-forward"},
{"nat/POSTROUTING", "-j ts-postrouting"},
}
for _, ipt := range []map[string][]string{n.ipt4, n.ipt6} {
for _, r := range newRules {
if err := insertRule(n, ipt, r.chain, r.rule); err != nil {
return err
}
}
}
return nil
}
func (n *fakeIPTablesRunner) DelHooks(logf logger.Logf) error {
delRules := []iptRule{
{"filter/INPUT", "-j ts-input"},
{"filter/FORWARD", "-j ts-forward"},
{"nat/POSTROUTING", "-j ts-postrouting"},
}
for _, ipt := range []map[string][]string{n.ipt4, n.ipt6} {
for _, r := range delRules {
if err := deleteRule(n, ipt, r.chain, r.rule); err != nil {
return err
}
}
}
return nil
}
func (n *fakeIPTablesRunner) AddChains() error {
if n.addChainsErr != nil {
return n.addChainsErr
}
for _, ipt := range []map[string][]string{n.ipt4, n.ipt6} {
for _, chain := range []string{"filter/ts-input", "filter/ts-forward", "nat/ts-postrouting"} {
ipt[chain] = nil
}
}
return nil
}
func (n *fakeIPTablesRunner) DelChains() error {
for _, ipt := range []map[string][]string{n.ipt4, n.ipt6} {
for chain := range ipt {
if strings.HasPrefix(chain, "filter/ts-") || strings.HasPrefix(chain, "nat/ts-") {
delete(ipt, chain)
}
}
}
return nil
}
func (n *fakeIPTablesRunner) DelBase() error {
for _, ipt := range []map[string][]string{n.ipt4, n.ipt6} {
for _, chain := range []string{"filter/ts-input", "filter/ts-forward", "nat/ts-postrouting"} {
ipt[chain] = nil
}
}
return nil
}
func (n *fakeIPTablesRunner) AddSNATRule() error {
newRule := fmt.Sprintf("-m mark --mark %s/%s -j MASQUERADE", tsconst.LinuxSubnetRouteMark, tsconst.LinuxFwmarkMask)
for _, ipt := range []map[string][]string{n.ipt4, n.ipt6} {
if err := appendRule(n, ipt, "nat/ts-postrouting", newRule); err != nil {
return err
}
}
return nil
}
func (n *fakeIPTablesRunner) DelSNATRule() error {
delRule := fmt.Sprintf("-m mark --mark %s/%s -j MASQUERADE", tsconst.LinuxSubnetRouteMark, tsconst.LinuxFwmarkMask)
for _, ipt := range []map[string][]string{n.ipt4, n.ipt6} {
if err := deleteRule(n, ipt, "nat/ts-postrouting", delRule); err != nil {
return err
}
}
return nil
}
func (n *fakeIPTablesRunner) AddStatefulRule(tunname string) error {
newRule := fmt.Sprintf("-o %s -m conntrack ! --ctstate ESTABLISHED,RELATED -j DROP", tunname)
for _, ipt := range []map[string][]string{n.ipt4, n.ipt6} {
// Mimic the real runner and insert after the 'accept all' rule
wantRule := fmt.Sprintf("-o %s -j ACCEPT", tunname)
const chain = "filter/ts-forward"
pos := slices.Index(ipt[chain], wantRule)
if pos < 0 {
n.t.Fatalf("no rule %q in chain %s", wantRule, chain)
}
insertRuleAt(n, ipt, chain, pos, newRule)
}
return nil
}
func (n *fakeIPTablesRunner) DelStatefulRule(tunname string) error {
delRule := fmt.Sprintf("-o %s -m conntrack ! --ctstate ESTABLISHED,RELATED -j DROP", tunname)
for _, ipt := range []map[string][]string{n.ipt4, n.ipt6} {
if err := deleteRule(n, ipt, "filter/ts-forward", delRule); err != nil {
return err
}
}
return nil
}
// buildMagicsockPortRule builds a fake rule to use in AddMagicsockPortRule and
// DelMagicsockPortRule below.
func buildMagicsockPortRule(port uint16) string {
return fmt.Sprintf("-p udp --dport %v -j ACCEPT", port)
}
// AddMagicsockPortRule implements the NetfilterRunner interface, but stores
// rules in fakeIPTablesRunner's internal maps rather than actually calling out
// to iptables. This is mainly to test the linux router implementation.
func (n *fakeIPTablesRunner) AddMagicsockPortRule(port uint16, network string) error {
var ipt map[string][]string
switch network {
case "udp4":
ipt = n.ipt4
case "udp6":
ipt = n.ipt6
default:
return fmt.Errorf("unsupported network %s", network)
}
rule := buildMagicsockPortRule(port)
if err := appendRule(n, ipt, "filter/ts-input", rule); err != nil {
return err
}
return nil
}
// DelMagicsockPortRule implements the NetfilterRunner interface, but removes
// rules from fakeIPTablesRunner's internal maps rather than actually calling
// out to iptables. This is mainly to test the linux router implementation.
func (n *fakeIPTablesRunner) DelMagicsockPortRule(port uint16, network string) error {
var ipt map[string][]string
switch network {
case "udp4":
ipt = n.ipt4
case "udp6":
ipt = n.ipt6
default:
return fmt.Errorf("unsupported network %s", network)
}
rule := buildMagicsockPortRule(port)
if err := deleteRule(n, ipt, "filter/ts-input", rule); err != nil {
return err
}
return nil
}
func (n *fakeIPTablesRunner) AddConnmarkSaveRule() error {
n.addConnmarkSaveCalls++
// PREROUTING rule: restore mark from conntrack
prerouteRule := "-m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000"
for _, ipt := range []map[string][]string{n.ipt4, n.ipt6} {
if err := insertRule(n, ipt, "mangle/PREROUTING", prerouteRule); err != nil {
return err
}
}
// OUTPUT rule: save mark to conntrack for NEW connections
outputRule := "-m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000"
for _, ipt := range []map[string][]string{n.ipt4, n.ipt6} {
if err := insertRule(n, ipt, "mangle/OUTPUT", outputRule); err != nil {
return err
}
}
return nil
}
func (n *fakeIPTablesRunner) DelConnmarkSaveRule() error {
prerouteRule := "-m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark --nfmask 0xff0000 --ctmask 0xff0000"
for _, ipt := range []map[string][]string{n.ipt4, n.ipt6} {
deleteRule(n, ipt, "mangle/PREROUTING", prerouteRule) // ignore errors
}
outputRule := "-m conntrack --ctstate NEW -m mark ! --mark 0x0/0xff0000 -j CONNMARK --save-mark --nfmask 0xff0000 --ctmask 0xff0000"
for _, ipt := range []map[string][]string{n.ipt4, n.ipt6} {
deleteRule(n, ipt, "mangle/OUTPUT", outputRule) // ignore errors
}
return nil
}
func buildExternalCGNATRules(mode linuxfw.CGNATMode, tunname string) ([]iptRule, error) {
switch mode {
case linuxfw.CGNATModeDrop:
return []iptRule{
{"filter/ts-input", fmt.Sprintf("! -i %s -s %s -j RETURN", tunname, tsaddr.ChromeOSVMRange().String())},
{"filter/ts-input", fmt.Sprintf("! -i %s -s %s -j DROP", tunname, tsaddr.CGNATRange().String())},
}, nil
case linuxfw.CGNATModeReturn:
return []iptRule{
{"filter/ts-input", fmt.Sprintf("! -i %s -s %s -j RETURN", tunname, tsaddr.CGNATRange().String())},
}, nil
default:
return nil, fmt.Errorf("unsupported mode %q", mode)
}
}
func (n *fakeIPTablesRunner) AddExternalCGNATRules(mode linuxfw.CGNATMode, tunname string) error {
n.addExternalCGNATCalls++
rules, err := buildExternalCGNATRules(mode, tunname)
if err != nil {
return err
}
for _, rule := range rules {
if err := appendRule(n, n.ipt4, rule.chain, rule.rule); err != nil {
return fmt.Errorf("add rule %q to chain %q: %w", rule.rule, rule.chain, err)
}
}
return nil
}
func (n *fakeIPTablesRunner) DelExternalCGNATRules(mode linuxfw.CGNATMode, tunname string) error {
rules, err := buildExternalCGNATRules(mode, tunname)
if err != nil {
return err
}
for _, rule := range rules {
if err := deleteRule(n, n.ipt4, rule.chain, rule.rule); err != nil {
return fmt.Errorf("del rule %q to chain %q: %w", rule.rule, rule.chain, err)
}
}
return nil
}
func (n *fakeIPTablesRunner) HasIPV6() bool { return true }
func (n *fakeIPTablesRunner) HasIPV6NAT() bool { return true }
func (n *fakeIPTablesRunner) HasIPV6Filter() bool { return true }
// fakeOS implements commandRunner and provides v4 and v6
// netfilterRunners, but captures changes without touching the OS.
type fakeOS struct {
t *testing.T
up bool
ips []string
routes []string
rules []string
// This test tests on the router level, so we will not bother
// with using iptables or nftables, chose the simpler one.
nfr linuxfw.NetfilterRunner
}
func NewFakeOS(t *testing.T) *fakeOS {
return &fakeOS{
t: t,
nfr: newIPTablesRunner(t),
}
}
var errExec = errors.New("execution failed")
func (o *fakeOS) String() string {
var b strings.Builder
if o.up {
b.WriteString("up\n")
} else {
b.WriteString("down\n")
}
for _, ip := range o.ips {
fmt.Fprintf(&b, "ip addr add %s\n", ip)
}
for _, route := range o.routes {
fmt.Fprintf(&b, "ip route add %s\n", route)
}
for _, rule := range o.rules {
fmt.Fprintf(&b, "ip rule add %s\n", rule)
}
var chains []string
for chain := range o.nfr.(*fakeIPTablesRunner).ipt4 {
chains = append(chains, chain)
}
sort.Strings(chains)
for _, chain := range chains {
for _, rule := range o.nfr.(*fakeIPTablesRunner).ipt4[chain] {
fmt.Fprintf(&b, "v4/%s %s\n", chain, rule)
}
}
chains = nil
for chain := range o.nfr.(*fakeIPTablesRunner).ipt6 {
chains = append(chains, chain)
}
sort.Strings(chains)
for _, chain := range chains {
for _, rule := range o.nfr.(*fakeIPTablesRunner).ipt6[chain] {
fmt.Fprintf(&b, "v6/%s %s\n", chain, rule)
}
}
return b.String()[:len(b.String())-1]
}
func (o *fakeOS) run(args ...string) error {
unexpected := func() error {
o.t.Errorf("unexpected invocation %q", strings.Join(args, " "))
return errors.New("unrecognized invocation")
}
if args[0] != "ip" {
return unexpected()
}
if len(args) == 2 && args[1] == "rule" {
// naked invocation of `ip rule` is a feature test. Return
// successfully.
return nil
}
family := ""
rest := strings.Join(args[3:], " ")
if args[1] == "-4" || args[1] == "-6" {
family = args[1]
copy(args[1:], args[2:])
args = args[:len(args)-1]
rest = family + " " + strings.Join(args[3:], " ")
}
var ls *[]string
switch args[1] {
case "link":
got := strings.Join(args[2:], " ")
switch got {
case "set dev tailscale0 up":
o.up = true
case "set dev tailscale0 down":
o.up = false
default:
return unexpected()
}
return nil
case "addr":
ls = &o.ips
case "route":
ls = &o.routes
case "rule":
ls = &o.rules
default:
return unexpected()
}
switch args[2] {
case "add":
if slices.Contains(*ls, rest) {
o.t.Errorf("can't add %q, already present", rest)
return errors.New("already exists")
}
*ls = append(*ls, rest)
sort.Strings(*ls)
case "del":
found := false
for i, el := range *ls {
if el == rest {
found = true
*ls = append((*ls)[:i], (*ls)[i+1:]...)
break
}
}
if !found {
o.t.Logf("note: can't delete %q, not present", rest)
// 'ip rule del' exits with code 2 when a row is
// missing. We don't want to consider that an error,
// for cleanup purposes.
// TODO(apenwarr): this is a hack.
// I'd like to return an exec.ExitError(2) here, but
// I can't, because the ExitCode is implemented in
// os.ProcessState, which is an opaque object I can't
// instantiate or modify. Go's 75 levels of abstraction
// between me and an 8-bit int are really paying off
// here, as you can see.
return errors.New("exitcode:2")
}
default:
return unexpected()
}
return nil
}
func (o *fakeOS) output(args ...string) ([]byte, error) {
want := "ip rule list priority 10000"
got := strings.Join(args, " ")
if got != want {
o.t.Errorf("unexpected command that wants output: %v", got)
return nil, errExec
}
var ret []string
for _, rule := range o.rules {
if strings.Contains(rule, "10000") {
ret = append(ret, rule)
}
}
return []byte(strings.Join(ret, "\n")), nil
}
var tunTestNum int64
func createTestTUN(t *testing.T) tun.Device {
const minimalMTU = 1280
tunName := fmt.Sprintf("tuntest%d", atomic.AddInt64(&tunTestNum, 1))
tun, err := tun.CreateTUN(tunName, minimalMTU)
if err != nil {
t.Fatalf("CreateTUN(%q): %v", tunName, err)
}
return tun
}
type linuxTest struct {
tun tun.Device
mon *netmon.Monitor
r *linuxRouter
logOutput tstest.MemLogger
}
func (lt *linuxTest) Close() error {
if lt.tun != nil {
lt.tun.Close()
}
if lt.mon != nil {
lt.mon.Close()
}
return nil
}
func newLinuxRootTest(t *testing.T) (*linuxTest, *eventbus.Bus) {
tstest.RequireRoot(t)
lt := new(linuxTest)
lt.tun = createTestTUN(t)
logf := lt.logOutput.Logf
bus := eventbustest.NewBus(t)
mon, err := netmon.New(bus, logger.Discard)
if err != nil {
lt.Close()
t.Fatal(err)
}
mon.Start()
lt.mon = mon
r, err := newUserspaceRouter(logf, lt.tun, mon, nil, bus)
if err != nil {
lt.Close()
t.Fatal(err)
}
lr := r.(*linuxRouter)
if err := lr.upInterface(); err != nil {
lt.Close()
t.Fatal(err)
}
lt.r = lr
return lt, bus
}
func TestRuleDeletedEvent(t *testing.T) {
fake := NewFakeOS(t)
lt, bus := newLinuxRootTest(t)
lt.r.nfr = fake.nfr
defer lt.Close()
event := netmon.RuleDeleted{
Table: 52,
Priority: 5210,
}
tw := eventbustest.NewWatcher(t, bus)
t.Logf("Value before: %t", lt.r.ruleRestorePending.Load())
if lt.r.ruleRestorePending.Load() {
t.Errorf("rule deletion already ongoing")
}
injector := eventbustest.NewInjector(t, bus)
eventbustest.Inject(injector, event)
eventbustest.Expect(tw, eventbustest.Type[AddIPRules]())
}
func TestDelRouteIdempotent(t *testing.T) {
fake := NewFakeOS(t)
lt, _ := newLinuxRootTest(t)
lt.r.nfr = fake.nfr
defer lt.Close()
for _, s := range []string{
"192.0.2.0/24", // RFC 5737
"2001:DB8::/32", // RFC 3849
} {
cidr := netip.MustParsePrefix(s)
if err := lt.r.addRoute(cidr); err != nil {
t.Error(err)
continue
}
for i := range 2 {
if err := lt.r.delRoute(cidr); err != nil {
t.Errorf("delRoute(i=%d): %v", i, err)
}
}
}
if t.Failed() {
out := lt.logOutput.String()
t.Logf("Log output:\n%s", out)
}
}
func TestAddRemoveRules(t *testing.T) {
fake := NewFakeOS(t)
lt, _ := newLinuxRootTest(t)
lt.r.nfr = fake.nfr
defer lt.Close()
r := lt.r
step := func(name string, f func() error) {
t.Logf("Doing %v ...", name)
if err := f(); err != nil {
t.Fatalf("%s: %v", name, err)
}
rules, err := netlink.RuleList(netlink.FAMILY_ALL)
if err != nil {
t.Fatal(err)
}
for _, r := range rules {
if r.Priority >= 5000 && r.Priority <= 5999 {
t.Logf("Rule: %+v", r)
}
}
}
step("init_del_and_add", r.addIPRules)
step("dup_add", r.justAddIPRules)
step("del", r.delIPRules)
step("dup_del", r.delIPRules)
}
func TestDebugListLinks(t *testing.T) {
links, err := netlink.LinkList()
if err != nil {
t.Fatal(err)
}
for _, ln := range links {
t.Logf("Link: %+v", ln)
}
}
func TestDebugListRoutes(t *testing.T) {
// We need to pass a non-nil route to RouteListFiltered, along
// with the netlink.RT_FILTER_TABLE bit set in the filter
// mask, otherwise it ignores non-main routes.
filter := &netlink.Route{}
routes, err := netlink.RouteListFiltered(netlink.FAMILY_ALL, filter, netlink.RT_FILTER_TABLE)
if err != nil {
t.Fatal(err)
}
for _, r := range routes {
t.Logf("Route: %+v", r)
}
}
var famName = map[int]string{
netlink.FAMILY_ALL: "all",
netlink.FAMILY_V4: "v4",
netlink.FAMILY_V6: "v6",
}
func TestDebugListRules(t *testing.T) {
for _, fam := range []int{netlink.FAMILY_V4, netlink.FAMILY_V6, netlink.FAMILY_ALL} {
t.Run(famName[fam], func(t *testing.T) {
rules, err := netlink.RuleList(fam)
if err != nil {
t.Skipf("skip; RuleList fails with: %v", err)
}
for _, r := range rules {
t.Logf("Rule: %+v", r)
}
})
}
}
func TestCheckIPRuleSupportsV6(t *testing.T) {
err := linuxfw.CheckIPRuleSupportsV6(t.Logf)
if err != nil && os.Getuid() != 0 {
t.Skipf("skipping, error when not root: %v", err)
}
// Just log it. For interactive testing only.
// Some machines running our tests might not have IPv6.
t.Logf("Got: %v", err)
}
func TestBusyboxParseVersion(t *testing.T) {
input := `BusyBox v1.34.1 (2022-09-01 16:10:29 UTC) multi-call binary.
BusyBox is copyrighted by many authors between 1998-2015.
Licensed under GPLv2. See source distribution for detailed
copyright notices.
Usage: busybox [function [arguments]...]
or: busybox --list[-full]
or: busybox --show SCRIPT
or: busybox --install [-s] [DIR]
or: function [arguments]...
BusyBox is a multi-call binary that combines many common Unix
utilities into a single executable. Most people will create a
link to busybox for each function they wish to use and BusyBox
will act like whatever it was invoked as.
`
v1, v2, v3, err := busyboxParseVersion(input)
if err != nil {
t.Fatalf("busyboxParseVersion() failed: %v", err)
}
if got, want := fmt.Sprintf("%d.%d.%d", v1, v2, v3), "1.34.1"; got != want {
t.Errorf("version = %q, want %q", got, want)
}
}
func TestCIDRDiff(t *testing.T) {
pfx := func(p ...string) []netip.Prefix {
var ret []netip.Prefix
for _, s := range p {
ret = append(ret, netip.MustParsePrefix(s))
}
return ret
}
tests := []struct {
old []netip.Prefix
new []netip.Prefix
wantAdd []netip.Prefix
wantDel []netip.Prefix
final []netip.Prefix
}{
{
old: nil,
new: pfx("1.1.1.1/32"),
wantAdd: pfx("1.1.1.1/32"),
final: pfx("1.1.1.1/32"),
},
{
old: pfx("1.1.1.1/32"),
new: pfx("1.1.1.1/32"),
final: pfx("1.1.1.1/32"),
},
{
old: pfx("1.1.1.1/32", "2.3.4.5/32"),
new: pfx("1.1.1.1/32"),
wantDel: pfx("2.3.4.5/32"),
final: pfx("1.1.1.1/32"),
},
{
old: pfx("1.1.1.1/32", "2.3.4.5/32"),
new: pfx("1.0.0.0/32", "3.4.5.6/32"),
wantDel: pfx("1.1.1.1/32", "2.3.4.5/32"),
wantAdd: pfx("1.0.0.0/32", "3.4.5.6/32"),
final: pfx("1.0.0.0/32", "3.4.5.6/32"),
},
}
for _, tc := range tests {
om := make(map[netip.Prefix]bool)
for _, p := range tc.old {
om[p] = true
}
var added []netip.Prefix
var deleted []netip.Prefix
fm, err := cidrDiff("test", om, tc.new, func(p netip.Prefix) error {
if len(deleted) > 0 {
t.Error("delete called before add")
}
added = append(added, p)
return nil
}, func(p netip.Prefix) error {
deleted = append(deleted, p)
return nil
}, t.Logf)
if err != nil {
t.Fatal(err)
}
slices.SortFunc(added, netipx.ComparePrefix)
slices.SortFunc(deleted, netipx.ComparePrefix)
if !reflect.DeepEqual(added, tc.wantAdd) {
t.Errorf("added = %v, want %v", added, tc.wantAdd)
}
if !reflect.DeepEqual(deleted, tc.wantDel) {
t.Errorf("deleted = %v, want %v", deleted, tc.wantDel)
}
// Check that the final state is correct.
if len(fm) != len(tc.final) {
t.Fatalf("final state = %v, want %v", fm, tc.final)
}
for _, p := range tc.final {
if !fm[p] {
t.Errorf("final state = %v, want %v", fm, tc.final)
}
}
}
}
var (
fwmaskSupported bool
fwmaskSupportedOnce sync.Once
fwmaskAdjustRe = regexp.MustCompile(`(?m)(fwmark 0x[0-9a-f]+)/0x[0-9a-f]+`)
)
// adjustFwmask removes the "/0xmask" string from fwmask stanzas if the
// installed 'ip' binary does not support that format.
func adjustFwmask(t *testing.T, s string) string {
t.Helper()
fwmaskSupportedOnce.Do(func() {
fwmaskSupported, _ = ipCmdSupportsFwmask()
})
if fwmaskSupported {
return s
}
return fwmaskAdjustRe.ReplaceAllString(s, "$1")
}
func TestIPRulesForUBNT(t *testing.T) {
// Override the global getDistroFunc
getDistroFunc = func() distro.Distro {
return distro.UBNT
}
defer func() { getDistroFunc = distro.Get }() // Restore original after the test
expected := ubntIPRules
actual := ipRules()
if len(expected) != len(actual) {
t.Fatalf("Expected %d rules, got %d", len(expected), len(actual))
}
for i, rule := range expected {
if rule != actual[i] {
t.Errorf("Rule mismatch at index %d: expected %+v, got %+v", i, rule, actual[i])
}
}
}
func TestUpdateMagicsockPortChange(t *testing.T) {
nfr := &fakeIPTablesRunner{
t: t,
ipt4: make(map[string][]string),
ipt6: make(map[string][]string),
}
nfr.ipt4["filter/ts-input"] = []string{}
r := &linuxRouter{
logf: logger.Discard,
health: new(health.Tracker),
netfilterMode: netfilterOn,
nfr: nfr,
}
if err := r.updateMagicsockPort(12345, "udp4"); err != nil {
t.Fatalf("failed to set initial port: %v", err)
}
if err := r.updateMagicsockPort(54321, "udp4"); err != nil {
t.Fatalf("failed to update port: %v", err)
}
newPortRule := buildMagicsockPortRule(54321)
hasNewRule := slices.Contains(nfr.ipt4["filter/ts-input"], newPortRule)
if !hasNewRule {
t.Errorf("firewall rule for NEW port 54321 not found.\nExpected: %s\nActual rules: %v",
newPortRule, nfr.ipt4["filter/ts-input"])
}
oldPortRule := buildMagicsockPortRule(12345)
hasOldRule := slices.Contains(nfr.ipt4["filter/ts-input"], oldPortRule)
if hasOldRule {
t.Errorf("firewall rule for OLD port 12345 still exists (should be deleted).\nFound: %s\nAll rules: %v",
oldPortRule, nfr.ipt4["filter/ts-input"])
}
}
// TestSetSkipsNetfilterAddonsWhenSetupFails verifies that Set does not invoke
// rule-management methods that depend on the ts-* chains existing when chain
// setup failed.
func TestSetSkipsNetfilterAddonsWhenSetupFails(t *testing.T) {
nfr := newIPTablesRunner(t).(*fakeIPTablesRunner)
nfr.addChainsErr = errors.New("kernel lacks netfilter support")
bus := eventbus.New()
defer bus.Close()
mon, err := netmon.New(bus, logger.Discard)
if err != nil {
t.Fatal(err)
}
mon.Start()
defer mon.Close()
fake := NewFakeOS(t)
ht := health.NewTracker(bus)
r, err := newUserspaceRouterAdvanced(logger.Discard, "tailscale0", mon, fake, ht, bus)
if err != nil {
t.Fatalf("newUserspaceRouterAdvanced: %v", err)
}
lr := r.(*linuxRouter)
lr.nfr = nfr
if err := lr.Up(); err != nil {
t.Fatalf("Up: %v", err)
}
defer lr.Close()
cfg := &Config{
LocalAddrs: mustCIDRs("100.101.102.103/10"),
NetfilterMode: netfilterOn,
}
// Set must return an error (chain setup failed) but must not panic.
if err := lr.Set(cfg); err == nil {
t.Fatal("Set returned nil; want error because AddChains failed")
}
if lr.netfilterMode != netfilterOff {
t.Errorf("netfilterMode = %v; want netfilterOff after failed AddChains", lr.netfilterMode)
}
if nfr.addConnmarkSaveCalls != 0 {
t.Errorf("AddConnmarkSaveRule called %d times; want 0 when chain setup failed",
nfr.addConnmarkSaveCalls)
}
if nfr.addExternalCGNATCalls != 0 {
t.Errorf("AddExternalCGNATRules called %d times; want 0 when chain setup failed",
nfr.addExternalCGNATCalls)
}
}