wgengine/{magicsock,userspace,router}: move portupdates to the eventbus (#17423)

Also pull out interface method only needed in Linux.

Instead of having userspace do the call into the router, just let the
router pick up the change itself.

Updates #15160

Signed-off-by: Claus Lensbøl <claus@tailscale.com>
This commit is contained in:
Claus Lensbøl
2025-10-07 09:30:27 -04:00
committed by GitHub
parent eabc62a9dd
commit 63f7a400a8
10 changed files with 83 additions and 122 deletions

View File

@@ -14,6 +14,7 @@ import (
"os/exec"
"strconv"
"strings"
"sync"
"sync/atomic"
"syscall"
"time"
@@ -54,21 +55,14 @@ const (
)
type linuxRouter struct {
closed atomic.Bool
logf func(fmt string, args ...any)
tunname string
netMon *netmon.Monitor
health *health.Tracker
eventSubs eventbus.Monitor
rulesAddedPub *eventbus.Publisher[AddIPRules]
unregNetMon func()
addrs map[netip.Prefix]bool
routes map[netip.Prefix]bool
localRoutes map[netip.Prefix]bool
snatSubnetRoutes bool
statefulFiltering bool
netfilterMode preftype.NetfilterMode
netfilterKind string
closed atomic.Bool
logf func(fmt string, args ...any)
tunname string
netMon *netmon.Monitor
health *health.Tracker
eventSubs eventbus.Monitor
rulesAddedPub *eventbus.Publisher[AddIPRules]
unregNetMon func()
// ruleRestorePending is whether a timer has been started to
// restore deleted ip rules.
@@ -86,8 +80,16 @@ type linuxRouter struct {
cmd commandRunner
nfr linuxfw.NetfilterRunner
magicsockPortV4 atomic.Uint32 // actually a uint16
magicsockPortV6 atomic.Uint32 // actually a uint16
mu sync.Mutex
addrs map[netip.Prefix]bool
routes map[netip.Prefix]bool
localRoutes map[netip.Prefix]bool
snatSubnetRoutes bool
statefulFiltering bool
netfilterMode preftype.NetfilterMode
netfilterKind string
magicsockPortV4 uint16
magicsockPortV6 uint16
}
func newUserspaceRouter(logf logger.Logf, tunDev tun.Device, netMon *netmon.Monitor, health *health.Tracker, bus *eventbus.Bus) (router.Router, error) {
@@ -169,6 +171,7 @@ func newUserspaceRouterAdvanced(logf logger.Logf, tunname string, netMon *netmon
// [eventbus.Client] is closed.
func (r *linuxRouter) consumeEventbusTopics(ec *eventbus.Client) func(*eventbus.Client) {
ruleDeletedSub := eventbus.Subscribe[netmon.RuleDeleted](ec)
portUpdateSub := eventbus.Subscribe[router.PortUpdate](ec)
return func(ec *eventbus.Client) {
for {
select {
@@ -176,6 +179,11 @@ func (r *linuxRouter) consumeEventbusTopics(ec *eventbus.Client) func(*eventbus.
return
case rs := <-ruleDeletedSub.Events():
r.onIPRuleDeleted(rs.Table, rs.Priority)
case pu := <-portUpdateSub.Events():
r.logf("portUpdate(port=%v, network=%s)", pu.UDPPort, pu.EndpointNetwork)
if err := r.updateMagicsockPort(pu.UDPPort, pu.EndpointNetwork); err != nil {
r.logf("updateMagicsockPort(port=%v, network=%s) failed: %v", pu.UDPPort, pu.EndpointNetwork, err)
}
}
}
}
@@ -355,7 +363,9 @@ func (r *linuxRouter) onIPRuleDeleted(table uint8, priority uint32) {
}
func (r *linuxRouter) Up() error {
if err := r.setNetfilterMode(netfilterOff); err != nil {
r.mu.Lock()
defer r.mu.Unlock()
if err := r.setNetfilterModeLocked(netfilterOff); err != nil {
return fmt.Errorf("setting netfilter mode: %w", err)
}
if err := r.addIPRules(); err != nil {
@@ -369,6 +379,8 @@ func (r *linuxRouter) Up() error {
}
func (r *linuxRouter) Close() error {
r.mu.Lock()
defer r.mu.Unlock()
r.closed.Store(true)
if r.unregNetMon != nil {
r.unregNetMon()
@@ -380,7 +392,7 @@ func (r *linuxRouter) Close() error {
if err := r.delIPRules(); err != nil {
return err
}
if err := r.setNetfilterMode(netfilterOff); err != nil {
if err := r.setNetfilterModeLocked(netfilterOff); err != nil {
return err
}
if err := r.delRoutes(); err != nil {
@@ -394,10 +406,10 @@ func (r *linuxRouter) Close() error {
return nil
}
// setupNetfilter initializes the NetfilterRunner in r.nfr. It expects r.nfr
// setupNetfilterLocked initializes the NetfilterRunner in r.nfr. It expects r.nfr
// to be nil, or the current netfilter to be set to netfilterOff.
// kind should be either a linuxfw.FirewallMode, or the empty string for auto.
func (r *linuxRouter) setupNetfilter(kind string) error {
func (r *linuxRouter) setupNetfilterLocked(kind string) error {
r.netfilterKind = kind
var err error
@@ -411,24 +423,26 @@ func (r *linuxRouter) setupNetfilter(kind string) error {
// Set implements the Router interface.
func (r *linuxRouter) Set(cfg *router.Config) error {
r.mu.Lock()
defer r.mu.Unlock()
var errs []error
if cfg == nil {
cfg = &shutdownConfig
}
if cfg.NetfilterKind != r.netfilterKind {
if err := r.setNetfilterMode(netfilterOff); err != nil {
if err := r.setNetfilterModeLocked(netfilterOff); err != nil {
err = fmt.Errorf("could not disable existing netfilter: %w", err)
errs = append(errs, err)
} else {
r.nfr = nil
if err := r.setupNetfilter(cfg.NetfilterKind); err != nil {
if err := r.setupNetfilterLocked(cfg.NetfilterKind); err != nil {
errs = append(errs, err)
}
}
}
if err := r.setNetfilterMode(cfg.NetfilterMode); err != nil {
if err := r.setNetfilterModeLocked(cfg.NetfilterMode); err != nil {
errs = append(errs, err)
}
@@ -470,11 +484,11 @@ func (r *linuxRouter) Set(cfg *router.Config) error {
case cfg.StatefulFiltering == r.statefulFiltering:
// state already correct, nothing to do.
case cfg.StatefulFiltering:
if err := r.addStatefulRule(); err != nil {
if err := r.addStatefulRuleLocked(); err != nil {
errs = append(errs, err)
}
default:
if err := r.delStatefulRule(); err != nil {
if err := r.delStatefulRuleLocked(); err != nil {
errs = append(errs, err)
}
}
@@ -538,15 +552,17 @@ func (r *linuxRouter) updateStatefulFilteringWithDockerWarning(cfg *router.Confi
r.health.SetHealthy(dockerStatefulFilteringWarnable)
}
// UpdateMagicsockPort implements the Router interface.
func (r *linuxRouter) UpdateMagicsockPort(port uint16, network string) error {
// updateMagicsockPort implements the Router interface.
func (r *linuxRouter) updateMagicsockPort(port uint16, network string) error {
r.mu.Lock()
defer r.mu.Unlock()
if r.nfr == nil {
if err := r.setupNetfilter(r.netfilterKind); err != nil {
if err := r.setupNetfilterLocked(r.netfilterKind); err != nil {
return fmt.Errorf("could not setup netfilter: %w", err)
}
}
var magicsockPort *atomic.Uint32
var magicsockPort *uint16
switch network {
case "udp4":
magicsockPort = &r.magicsockPortV4
@@ -566,45 +582,41 @@ func (r *linuxRouter) UpdateMagicsockPort(port uint16, network string) error {
// set the port, we'll make the firewall rule when netfilter turns back on
if r.netfilterMode == netfilterOff {
magicsockPort.Store(uint32(port))
*magicsockPort = port
return nil
}
cur := magicsockPort.Load()
if cur == uint32(port) {
if *magicsockPort == port {
return nil
}
if cur != 0 {
if err := r.nfr.DelMagicsockPortRule(uint16(cur), network); err != nil {
if *magicsockPort != 0 {
if err := r.nfr.DelMagicsockPortRule(*magicsockPort, network); err != nil {
return fmt.Errorf("del magicsock port rule: %w", err)
}
}
if port != 0 {
if err := r.nfr.AddMagicsockPortRule(uint16(port), network); err != nil {
if err := r.nfr.AddMagicsockPortRule(*magicsockPort, network); err != nil {
return fmt.Errorf("add magicsock port rule: %w", err)
}
}
magicsockPort.Store(uint32(port))
*magicsockPort = port
return nil
}
// setNetfilterMode switches the router to the given netfilter
// setNetfilterModeLocked switches the router to the given netfilter
// mode. Netfilter state is created or deleted appropriately to
// reflect the new mode, and r.snatSubnetRoutes is updated to reflect
// the current state of subnet SNATing.
func (r *linuxRouter) setNetfilterMode(mode preftype.NetfilterMode) error {
func (r *linuxRouter) setNetfilterModeLocked(mode preftype.NetfilterMode) error {
if !platformCanNetfilter() {
mode = netfilterOff
}
if r.nfr == nil {
var err error
r.nfr, err = linuxfw.New(r.logf, r.netfilterKind)
if err != nil {
if err := r.setupNetfilterLocked(r.netfilterKind); err != nil {
return err
}
}
@@ -660,13 +672,13 @@ func (r *linuxRouter) setNetfilterMode(mode preftype.NetfilterMode) error {
if err := r.nfr.AddBase(r.tunname); err != nil {
return err
}
if mport := uint16(r.magicsockPortV4.Load()); mport != 0 {
if err := r.nfr.AddMagicsockPortRule(mport, "udp4"); err != nil {
if r.magicsockPortV4 != 0 {
if err := r.nfr.AddMagicsockPortRule(r.magicsockPortV4, "udp4"); err != nil {
return fmt.Errorf("could not add magicsock port rule v4: %w", err)
}
}
if mport := uint16(r.magicsockPortV6.Load()); mport != 0 && r.getV6FilteringAvailable() {
if err := r.nfr.AddMagicsockPortRule(mport, "udp6"); err != nil {
if r.magicsockPortV6 != 0 && r.getV6FilteringAvailable() {
if err := r.nfr.AddMagicsockPortRule(r.magicsockPortV6, "udp6"); err != nil {
return fmt.Errorf("could not add magicsock port rule v6: %w", err)
}
}
@@ -700,13 +712,13 @@ func (r *linuxRouter) setNetfilterMode(mode preftype.NetfilterMode) error {
if err := r.nfr.AddBase(r.tunname); err != nil {
return err
}
if mport := uint16(r.magicsockPortV4.Load()); mport != 0 {
if err := r.nfr.AddMagicsockPortRule(mport, "udp4"); err != nil {
if r.magicsockPortV4 != 0 {
if err := r.nfr.AddMagicsockPortRule(r.magicsockPortV4, "udp4"); err != nil {
return fmt.Errorf("could not add magicsock port rule v4: %w", err)
}
}
if mport := uint16(r.magicsockPortV6.Load()); mport != 0 && r.getV6FilteringAvailable() {
if err := r.nfr.AddMagicsockPortRule(mport, "udp6"); err != nil {
if r.magicsockPortV6 != 0 && r.getV6FilteringAvailable() {
if err := r.nfr.AddMagicsockPortRule(r.magicsockPortV6, "udp6"); err != nil {
return fmt.Errorf("could not add magicsock port rule v6: %w", err)
}
}
@@ -1483,9 +1495,9 @@ func (r *linuxRouter) delSNATRule() error {
return nil
}
// addStatefulRule adds a netfilter rule to perform stateful filtering from
// addStatefulRuleLocked adds a netfilter rule to perform stateful filtering from
// subnets onto the tailnet.
func (r *linuxRouter) addStatefulRule() error {
func (r *linuxRouter) addStatefulRuleLocked() error {
if r.netfilterMode == netfilterOff {
return nil
}
@@ -1493,9 +1505,9 @@ func (r *linuxRouter) addStatefulRule() error {
return r.nfr.AddStatefulRule(r.tunname)
}
// delStatefulRule removes the netfilter rule to perform stateful filtering
// delStatefulRuleLocked removes the netfilter rule to perform stateful filtering
// from subnets onto the tailnet.
func (r *linuxRouter) delStatefulRule() error {
func (r *linuxRouter) delStatefulRuleLocked() error {
if r.netfilterMode == netfilterOff {
return nil
}

View File

@@ -238,13 +238,6 @@ func (r *openbsdRouter) Set(cfg *router.Config) error {
return errq
}
// UpdateMagicsockPort implements the Router interface. This implementation
// does nothing and returns nil because this router does not currently need
// to know what the magicsock UDP port is.
func (r *openbsdRouter) UpdateMagicsockPort(_ uint16, _ string) error {
return nil
}
func (r *openbsdRouter) Close() error {
cleanUp(r.logf, r.tunname)
return nil

View File

@@ -115,13 +115,6 @@ func (r *plan9Router) Set(cfg *router.Config) error {
return nil
}
// UpdateMagicsockPort implements the Router interface. This implementation
// does nothing and returns nil because this router does not currently need
// to know what the magicsock UDP port is.
func (r *plan9Router) UpdateMagicsockPort(_ uint16, _ string) error {
return nil
}
func (r *plan9Router) Close() error {
// TODO(bradfitz): unbind
return nil

View File

@@ -206,13 +206,6 @@ func (r *userspaceBSDRouter) Set(cfg *router.Config) (reterr error) {
return reterr
}
// UpdateMagicsockPort implements the Router interface. This implementation
// does nothing and returns nil because this router does not currently need
// to know what the magicsock UDP port is.
func (r *userspaceBSDRouter) UpdateMagicsockPort(_ uint16, _ string) error {
return nil
}
func (r *userspaceBSDRouter) Close() error {
return nil
}

View File

@@ -114,13 +114,6 @@ func hasDefaultRoute(routes []netip.Prefix) bool {
return false
}
// UpdateMagicsockPort implements the Router interface. This implementation
// does nothing and returns nil because this router does not currently need
// to know what the magicsock UDP port is.
func (r *winRouter) UpdateMagicsockPort(_ uint16, _ string) error {
return nil
}
func (r *winRouter) Close() error {
r.firewall.clear()