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tailscale/wgengine/router/osrouter/router_linux_test.go
T
Brendan CreaneandGitHub cfd101f9d7 configure DNS even when router.Set fails (#20488) 
* wgengine: configure DNS even when router.Set fails

Reconfig configured the router first and returned on any router.Set error,
before the DNS block ran. On a host where router config fails on every
reconfig -- e.g. a tun MTU below 1280 that breaks IPv6, or a kernel missing
netfilter features -- the OS resolver was never told about MagicDNS or the
tailnet search domain, so tailnet names failed to resolve with no DNS error
in the logs.

Record the router error and continue instead of returning on it, still
attempt dns.Set, and join the router, DNS, and VPN-reconfigure errors into
the return value. DNS stays after router config (still needed: some DNS
managers refuse to apply settings before the device has an address); only
the error coupling is broken. Fixes a regression from 84430cdfa (v1.8.0).

Updates #20447

Signed-off-by: Brendan Creane <bcreane@gmail.com>

* wgengine/router/osrouter: gate IPv6 on per-interface support, not just global

getV6Available reported IPv6 usable whenever the netfilter runner reported
global IPv6 support, missing the case where the kernel has IPv6 but has not
enabled it on tailscale0 specifically -- e.g. when the tun MTU is below the
1280-byte IPv6 minimum, so /proc/sys/net/ipv6/conf/tailscale0 never exists
and the v6 address and route adds fail, aborting the whole Set. See #20447.

AND a per-interface check into getV6Available, evaluated per call so a later
Set picks up v6 if the interface gains it. All v6-gated operations funnel
through getV6Available, so Set now skips v6 gracefully instead of erroring.
Also remove the dead r.v6Available field that masked this with its global
name.

Updates #20447

Signed-off-by: Brendan Creane <bcreane@gmail.com>

---------

Signed-off-by: Brendan Creane <bcreane@gmail.com>
2026-07-16 14:53:30 -07:00

2000 lines
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// 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/util/set"
"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
// Don't consult the live /proc for the tun's IPv6 state in tests; the
// fake netfilter runner's HasIPV6 (noV6) is the authoritative v6 signal
// here. See #20447.
router.(*linuxRouter).interfaceV6Usable = func() bool { return true }
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, unless
// noV6 is set.
noV6 bool
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 !n.noV6 }
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) {
// addAddress uses netlink AddrReplace in production, which is
// idempotent; model that for addresses rather than erroring.
// Routes/rules keep strict add semantics.
if args[1] == "addr" {
return nil
}
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) {
got := strings.Join(args, " ")
if got == "ip -oneline addr show dev tailscale0" {
// Render o.ips (entries look like "<cidr> dev tailscale0") in a
// simplified `ip -oneline addr show` format that exposes the family token
// the parser keys off of.
var ret []string
for _, e := range o.ips {
cidr, _, _ := strings.Cut(e, " ")
p, err := netip.ParsePrefix(cidr)
if err != nil {
continue
}
fam := "inet"
if p.Addr().Is6() {
fam = "inet6"
}
ret = append(ret, fmt.Sprintf("3: tailscale0 %s %s scope global tailscale0", fam, cidr))
}
return []byte(strings.Join(ret, "\n")), nil
}
want := "ip rule list priority 10000"
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
// Keep the fake netfilter runner's HasIPV6 the sole v6 signal; don't
// consult the live /proc for the tun's IPv6 state. See #20447.
lr.interfaceV6Usable = func() bool { return true }
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)
}
}
// newTestLinuxRouter builds a linuxRouter backed by a fakeOS, brought up and
// ready for Set, mirroring TestSetSkipsNetfilterAddonsWhenSetupFails.
func newTestLinuxRouter(t *testing.T) (*linuxRouter, *fakeOS) {
t.Helper()
bus := eventbus.New()
t.Cleanup(bus.Close)
mon, err := netmon.New(bus, logger.Discard)
if err != nil {
t.Fatal(err)
}
mon.Start()
t.Cleanup(func() { 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 = fake.nfr
// Keep the fake netfilter runner's HasIPV6 (noV6) the sole v6 signal;
// don't consult the live /proc for the tun's IPv6 state. See #20447.
lr.interfaceV6Usable = func() bool { return true }
if err := lr.Up(); err != nil {
t.Fatalf("Up: %v", err)
}
t.Cleanup(func() { lr.Close() })
return lr, fake
}
// TestSetRemovesOrphanedTailscaleAddrs verifies that Set removes Tailscale-range
// addresses left on the interface by a previous instance (issue 19974), even
// though they're absent from the in-memory r.addrs map.
func TestSetRemovesOrphanedTailscaleAddrs(t *testing.T) {
lr, fake := newTestLinuxRouter(t)
// Simulate a tailscale0 that survived a restart still carrying a prior
// profile's CGNAT v4 and Tailscale ULA v6 addresses, plus a non-Tailscale
// address that must be left alone.
fake.ips = []string{
"100.64.0.99/32 dev tailscale0", // CGNAT v4 orphan
"fd7a:115c:a1e0::99/128 dev tailscale0", // ULA v6 orphan
"192.168.1.5/24 dev tailscale0", // non-Tailscale, leave alone
}
slices.Sort(fake.ips)
cfg := &Config{
LocalAddrs: mustCIDRs("100.64.0.1/32"),
NetfilterMode: netfilterOff,
}
if err := lr.Set(cfg); err != nil {
t.Fatalf("Set: %v", err)
}
if !slices.Contains(fake.ips, "100.64.0.1/32 dev tailscale0") {
t.Errorf("desired addr 100.64.0.1/32 not present; ips=%q", fake.ips)
}
for _, gone := range []string{
"100.64.0.99/32 dev tailscale0",
"fd7a:115c:a1e0::99/128 dev tailscale0",
} {
if slices.Contains(fake.ips, gone) {
t.Errorf("orphaned Tailscale addr %q was not removed; ips=%q", gone, fake.ips)
}
}
// Non-Tailscale address must be untouched.
if !slices.Contains(fake.ips, "192.168.1.5/24 dev tailscale0") {
t.Errorf("non-Tailscale addr 192.168.1.5/24 was wrongly removed; ips=%q", fake.ips)
}
}
// TestSetRemovesOrphanWithNetfilter verifies orphan removal also works with
// netfilter enabled, where delAddress additionally tears down the address's
// loopback rule. An orphan from a previous instance has no such rule, so this
// guards that removing it isn't blocked by the loopback-rule deletion (see the
// iptables DelLoopbackRule DeleteIfExists handling).
func TestSetRemovesOrphanWithNetfilter(t *testing.T) {
lr, fake := newTestLinuxRouter(t)
fake.ips = []string{
"100.64.0.99/32 dev tailscale0", // CGNAT v4 orphan, no loopback rule
}
cfg := &Config{
LocalAddrs: mustCIDRs("100.64.0.1/32"),
NetfilterMode: netfilterOn,
}
if err := lr.Set(cfg); err != nil {
t.Fatalf("Set: %v", err)
}
if slices.Contains(fake.ips, "100.64.0.99/32 dev tailscale0") {
t.Errorf("orphan was not removed with netfilter on; ips=%q", fake.ips)
}
if !slices.Contains(fake.ips, "100.64.0.1/32 dev tailscale0") {
t.Errorf("desired addr 100.64.0.1/32 not present; ips=%q", fake.ips)
}
}
// TestSetInstallsLoopbackRuleForExistingAddr covers the persisted-interface
// restart case: the node's own address is already on tailscale0 (so the kernel
// reports it), but its per-address loopback rule was flushed when the netfilter
// chains were rebuilt. Set must still install the loopback rule, i.e. it must
// not skip addAddress just because the address is already present -- which it
// would if a desired address were folded into the orphan set. See #19974.
func TestSetInstallsLoopbackRuleForExistingAddr(t *testing.T) {
lr, fake := newTestLinuxRouter(t)
// The node's own address persisted on the interface across the restart.
fake.ips = []string{
"100.64.0.1/32 dev tailscale0",
}
cfg := &Config{
LocalAddrs: mustCIDRs("100.64.0.1/32"),
NetfilterMode: netfilterOn,
}
if err := lr.Set(cfg); err != nil {
t.Fatalf("Set: %v", err)
}
nfr := fake.nfr.(*fakeIPTablesRunner)
wantRule := "-i lo -s 100.64.0.1 -j ACCEPT"
if !slices.Contains(nfr.ipt4["filter/ts-input"], wantRule) {
t.Errorf("loopback rule %q not installed for already-present addr; ts-input=%q",
wantRule, nfr.ipt4["filter/ts-input"])
}
}
// TestSetOrphanScanGatedByAddrChange verifies the interface is scanned for
// orphans on the first Set and when LocalAddrs changes, but not for route-only
// updates -- so a subnet router churning routes doesn't pay for a scan on every
// Set.
func TestSetOrphanScanGatedByAddrChange(t *testing.T) {
lr, fake := newTestLinuxRouter(t)
// First Set establishes steady state (scans, finds nothing to remove).
if err := lr.Set(&Config{
LocalAddrs: mustCIDRs("100.64.0.1/32"),
NetfilterMode: netfilterOff,
}); err != nil {
t.Fatalf("Set 1: %v", err)
}
// An orphan appears afterward. A route-only update leaves LocalAddrs
// unchanged, so the scan is skipped and the orphan stays in place.
fake.ips = append(fake.ips, "100.64.0.99/32 dev tailscale0")
slices.Sort(fake.ips)
if err := lr.Set(&Config{
LocalAddrs: mustCIDRs("100.64.0.1/32"),
Routes: mustCIDRs("10.0.0.0/24"),
NetfilterMode: netfilterOff,
}); err != nil {
t.Fatalf("Set 2 (route-only): %v", err)
}
if !slices.Contains(fake.ips, "100.64.0.99/32 dev tailscale0") {
t.Errorf("orphan removed on a route-only update; scan should have been skipped; ips=%q", fake.ips)
}
// When LocalAddrs changes, the scan runs again and the orphan is removed.
if err := lr.Set(&Config{
LocalAddrs: mustCIDRs("100.64.0.2/32"),
Routes: mustCIDRs("10.0.0.0/24"),
NetfilterMode: netfilterOff,
}); err != nil {
t.Fatalf("Set 3 (addr change): %v", err)
}
if slices.Contains(fake.ips, "100.64.0.99/32 dev tailscale0") {
t.Errorf("orphan not removed after LocalAddrs change; ips=%q", fake.ips)
}
}
// TestSetOrphanScanNotRetriedOnDuplicateLocalAddrs verifies the scan gate
// compares the desired address set rather than its length against r.addrs. A
// duplicate in LocalAddrs (or, equivalently, an address that fails to install)
// leaves r.addrs smaller than len(LocalAddrs); a length-based gate would then
// rescan on every Set. The set comparison treats the desired set as unchanged.
func TestSetOrphanScanNotRetriedOnDuplicateLocalAddrs(t *testing.T) {
lr, fake := newTestLinuxRouter(t)
// LocalAddrs with a duplicate: cidrDiff dedups, so r.addrs ends up smaller
// than len(LocalAddrs).
dupCfg := &Config{
LocalAddrs: mustCIDRs("100.64.0.1/32", "100.64.0.1/32"),
NetfilterMode: netfilterOff,
}
if err := lr.Set(dupCfg); err != nil {
t.Fatalf("Set 1: %v", err)
}
// An orphan appears; re-applying the same (duplicated) LocalAddrs must not
// trigger a rescan, so the orphan stays.
fake.ips = append(fake.ips, "100.64.0.99/32 dev tailscale0")
slices.Sort(fake.ips)
if err := lr.Set(dupCfg); err != nil {
t.Fatalf("Set 2: %v", err)
}
if !slices.Contains(fake.ips, "100.64.0.99/32 dev tailscale0") {
t.Errorf("rescan ran for an unchanged (duplicated) LocalAddrs; ips=%q", fake.ips)
}
}
// TestSetKeepsNonTailscaleAddrs is the safety check: Set must never remove
// addresses outside Tailscale's ranges, even when they're not in the config.
func TestSetKeepsNonTailscaleAddrs(t *testing.T) {
lr, fake := newTestLinuxRouter(t)
fake.ips = []string{
"192.168.1.5/24 dev tailscale0", // non-Tailscale v4
"fe80::1/64 dev tailscale0", // link-local v6
}
slices.Sort(fake.ips)
cfg := &Config{
LocalAddrs: mustCIDRs("100.64.0.1/32"),
NetfilterMode: netfilterOff,
}
if err := lr.Set(cfg); err != nil {
t.Fatalf("Set: %v", err)
}
for _, keep := range []string{
"192.168.1.5/24 dev tailscale0",
"fe80::1/64 dev tailscale0",
} {
if !slices.Contains(fake.ips, keep) {
t.Errorf("non-Tailscale addr %q was wrongly removed; ips=%q", keep, fake.ips)
}
}
}
func TestOrphanedAddrs(t *testing.T) {
p := netip.MustParsePrefix
// orphanedAddrs returns set-iteration order, so compare as sets.
got := set.SetOf(orphanedAddrs(
[]netip.Prefix{p("100.64.0.1/32"), p("100.64.0.99/32"), p("fd7a:115c:a1e0::99/128")},
[]netip.Prefix{p("100.64.0.1/32")},
))
want := set.SetOf([]netip.Prefix{p("100.64.0.99/32"), p("fd7a:115c:a1e0::99/128")})
if !got.Equal(want) {
t.Errorf("orphanedAddrs = %v; want %v", got.Slice(), want.Slice())
}
if orphanedAddrs(nil, []netip.Prefix{p("100.64.0.1/32")}) != nil {
t.Error("orphanedAddrs(nil, ...) should be nil")
}
}
// TestGetV6AvailableNilNFR verifies the v6-availability checks don't panic when
// r.nfr is nil, which happens if setupNetfilterLocked failed earlier in Set.
// The orphan sweep reaches getV6Available via reconcilableTailscaleIP, so this
// must not deref a nil runner.
func TestGetV6AvailableNilNFR(t *testing.T) {
r := &linuxRouter{} // nfr left nil
if r.getV6Available() {
t.Error("getV6Available() = true with nil nfr; want false")
}
if r.getV6FilteringAvailable() {
t.Error("getV6FilteringAvailable() = true with nil nfr; want false")
}
if r.reconcilableTailscaleIP(netip.MustParseAddr("fd7a:115c:a1e0::99")) {
t.Error("reconcilableTailscaleIP(v6) = true with nil nfr; want false")
}
}
// TestSetSkipsV6OrphansWhenV6Unavailable verifies that when IPv6 is
// unavailable, Set does not enumerate v6 orphans for removal. delAddress
// no-ops on v6 in that state, so enumerating them would let cidrDiff record a
// delete that never happened; instead we leave them out of the reconcile.
func TestSetSkipsV6OrphansWhenV6Unavailable(t *testing.T) {
lr, fake := newTestLinuxRouter(t)
fake.nfr.(*fakeIPTablesRunner).noV6 = true
fake.ips = []string{
"100.64.0.99/32 dev tailscale0", // CGNAT v4 orphan, removable
"fd7a:115c:a1e0::99/128 dev tailscale0", // ULA v6 orphan, not removable without v6
}
slices.Sort(fake.ips)
cfg := &Config{
LocalAddrs: mustCIDRs("100.64.0.1/32"),
NetfilterMode: netfilterOff,
}
if err := lr.Set(cfg); err != nil {
t.Fatalf("Set: %v", err)
}
// The v4 orphan is removed; the v6 orphan is left in place rather than
// being treated as removed via a no-op delete.
if slices.Contains(fake.ips, "100.64.0.99/32 dev tailscale0") {
t.Errorf("v4 orphan was not removed; ips=%q", fake.ips)
}
if !slices.Contains(fake.ips, "fd7a:115c:a1e0::99/128 dev tailscale0") {
t.Errorf("v6 orphan should be left alone when v6 is unavailable; ips=%q", fake.ips)
}
}
// TestSetSkipsV6WhenInterfaceV6Unusable verifies that when global IPv6 is
// available (the netfilter runner reports HasIPV6) but the kernel has not
// enabled IPv6 on the tunnel interface itself -- e.g. the tun MTU is below the
// 1280-byte IPv6 minimum -- Set skips the v6 address rather than failing. This
// is the #20447 scenario: historically the v6 addAddress errored, aborting the
// whole router pass, which in turn suppressed DNS configuration.
func TestSetSkipsV6WhenInterfaceV6Unusable(t *testing.T) {
lr, fake := newTestLinuxRouter(t)
// Global v6 is fine (fake nfr HasIPV6 defaults true), but the tun
// interface has no usable v6.
lr.interfaceV6Usable = func() bool { return false }
cfg := &Config{
LocalAddrs: mustCIDRs("100.64.0.1/32", "fd7a:115c:a1e0::1/128"),
NetfilterMode: netfilterOff,
}
if err := lr.Set(cfg); err != nil {
t.Fatalf("Set: %v", err)
}
// The v4 address is programmed; the v6 address is skipped rather than
// attempted (which would have errored on a v6-less interface).
if !slices.Contains(fake.ips, "100.64.0.1/32 dev tailscale0") {
t.Errorf("v4 address was not programmed; ips=%q", fake.ips)
}
if slices.Contains(fake.ips, "fd7a:115c:a1e0::1/128 dev tailscale0") {
t.Errorf("v6 address should be skipped when the interface has no usable v6; ips=%q", fake.ips)
}
}
// TestSetSnapshotsV6Usable verifies that a single Set consults the
// per-interface IPv6 check (which reads /proc) once, rather than once per
// address and route, even though many getV6Available calls happen within it.
func TestSetSnapshotsV6Usable(t *testing.T) {
lr, _ := newTestLinuxRouter(t)
var calls int
lr.interfaceV6Usable = func() bool {
calls++
return true
}
cfg := &Config{
LocalAddrs: mustCIDRs("100.64.0.1/32", "fd7a:115c:a1e0::1/128"),
Routes: mustCIDRs("10.0.0.0/8", "fd00::/8"),
NetfilterMode: netfilterOff,
}
if err := lr.Set(cfg); err != nil {
t.Fatalf("Set: %v", err)
}
if calls != 1 {
t.Errorf("interfaceV6Usable called %d times during one Set; want 1 (snapshotted)", calls)
}
}
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