@ -4,7 +4,7 @@
// Package monitor provides facilities for monitoring network
// Package monitor provides facilities for monitoring network
// interface and route changes. It primarily exists to know when
// interface and route changes. It primarily exists to know when
// portable devices move between different networks.
// portable devices move between different networks.
package itor package net mon
import ( import (
"encoding/json"
"encoding/json"
@ -48,15 +48,15 @@ type osMon interface {
IsInterestingInterface ( iface string ) bool
IsInterestingInterface ( iface string ) bool
} }
// Mon represents a monitoring instance.
// Mon itor represents a monitoring instance.
type Mon struct { type Mon itor struct {
logf logger . Logf
logf logger . Logf
om osMon // nil means not supported on this platform
om osMon // nil means not supported on this platform
change chan struct { }
change chan struct { }
stop chan struct { } // closed on Stop
stop chan struct { } // closed on Stop
mu sync . Mutex // guards all following fields
mu sync . Mutex // guards all following fields
cbs set . HandleSet [ interfaces. ChangeFunc]
cbs set . HandleSet [ ]
ruleDelCB set . HandleSet [ RuleDeleteCallback ]
ruleDelCB set . HandleSet [ RuleDeleteCallback ]
ifState * interfaces . State
ifState * interfaces . State
gwValid bool // whether gw and gwSelfIP are valid
gwValid bool // whether gw and gwSelfIP are valid
@ -70,12 +70,17 @@ type Mon struct {
timeJumped bool // whether we need to send a changed=true after a big time jump
timeJumped bool // whether we need to send a changed=true after a big time jump
} }
// ChangeFunc is a callback function registered with Monitor that's called when the
// network changed. The changed parameter is whether the network changed
// enough for State to have changed since the last callback.
type ChangeFunc func ( changed bool , state * interfaces . State )
// New instantiates and starts a monitoring instance.
// New instantiates and starts a monitoring instance.
// The returned monitor is inactive until it's started by the Start method.
// The returned monitor is inactive until it's started by the Start method.
// Use RegisterChangeCallback to get notified of network changes.
// Use RegisterChangeCallback to get notified of network changes.
func New ( logf logger . Logf ) ( * Mon , error ) { func New ( logf logger . Logf ) ( * Mon itor , error ) {
logf = logger . WithPrefix ( logf , "monitor: " )
logf = logger . WithPrefix ( logf , "monitor: " )
m := & Mon {
m := & Mon itor {
logf : logf ,
logf : logf ,
change : make ( chan struct { } , 1 ) ,
change : make ( chan struct { } , 1 ) ,
stop : make ( chan struct { } ) ,
stop : make ( chan struct { } ) ,
@ -102,13 +107,13 @@ func New(logf logger.Logf) (*Mon, error) {
// interfaces.
// interfaces.
//
//
// The returned value is owned by Mon; it must not be modified.
// The returned value is owned by Mon; it must not be modified.
func ( m * Mon ) InterfaceState ( ) * interfaces . State { func ( m * Mon itor ) InterfaceState ( ) * interfaces . State {
m . mu . Lock ( )
m . mu . Lock ( )
defer m . mu . Unlock ( )
defer m . mu . Unlock ( )
return m . ifState
return m . ifState
} }
func ( m * Mon ) interfaceStateUncached ( ) ( * interfaces . State , error ) { func ( m * Mon itor ) interfaceStateUncached ( ) ( * interfaces . State , error ) {
return interfaces . GetState ( )
return interfaces . GetState ( )
} }
@ -117,7 +122,7 @@ func (m *Mon) interfaceStateUncached() (*interfaces.State, error) {
//
//
// It's the same as interfaces.LikelyHomeRouterIP, but it caches the
// It's the same as interfaces.LikelyHomeRouterIP, but it caches the
// result until the monitor detects a network change.
// result until the monitor detects a network change.
func ( m * Mon ) GatewayAndSelfIP ( ) ( gw , myIP netip . Addr , ok bool ) { func ( m * Mon itor ) GatewayAndSelfIP ( ) ( gw , myIP netip . Addr , ok bool ) {
m . mu . Lock ( )
m . mu . Lock ( )
defer m . mu . Unlock ( )
defer m . mu . Unlock ( )
if m . gwValid {
if m . gwValid {
@ -133,7 +138,7 @@ func (m *Mon) GatewayAndSelfIP() (gw, myIP netip.Addr, ok bool) {
// RegisterChangeCallback adds callback to the set of parties to be
// RegisterChangeCallback adds callback to the set of parties to be
// notified (in their own goroutine) when the network state changes.
// notified (in their own goroutine) when the network state changes.
// To remove this callback, call unregister (or close the monitor).
// To remove this callback, call unregister (or close the monitor).
func ( m * Mon ) RegisterChangeCallback ( callback interfaces . ChangeFunc ) ( unregister func ( ) ) { func ( m * Mon itor ) RegisterChangeCallback ( callback ChangeFunc ) ( unregister func ( ) ) {
m . mu . Lock ( )
m . mu . Lock ( )
defer m . mu . Unlock ( )
defer m . mu . Unlock ( )
handle := m . cbs . Add ( callback )
handle := m . cbs . Add ( callback )
@ -153,7 +158,7 @@ type RuleDeleteCallback func(table uint8, priority uint32)
// RegisterRuleDeleteCallback adds callback to the set of parties to be
// RegisterRuleDeleteCallback adds callback to the set of parties to be
// notified (in their own goroutine) when a Linux ip rule is deleted.
// notified (in their own goroutine) when a Linux ip rule is deleted.
// To remove this callback, call unregister (or close the monitor).
// To remove this callback, call unregister (or close the monitor).
func ( m * Mon ) RegisterRuleDeleteCallback ( callback RuleDeleteCallback ) ( unregister func ( ) ) { func ( m * Mon itor ) RegisterRuleDeleteCallback ( callback RuleDeleteCallback ) ( unregister func ( ) ) {
m . mu . Lock ( )
m . mu . Lock ( )
defer m . mu . Unlock ( )
defer m . mu . Unlock ( )
handle := m . ruleDelCB . Add ( callback )
handle := m . ruleDelCB . Add ( callback )
@ -166,7 +171,7 @@ func (m *Mon) RegisterRuleDeleteCallback(callback RuleDeleteCallback) (unregiste
// Start starts the monitor.
// Start starts the monitor.
// A monitor can only be started & closed once.
// A monitor can only be started & closed once.
func ( m * Mon ) Start ( ) { func ( m * Mon itor ) Start ( ) {
m . mu . Lock ( )
m . mu . Lock ( )
defer m . mu . Unlock ( )
defer m . mu . Unlock ( )
if m . started || m . closed {
if m . started || m . closed {
@ -187,7 +192,7 @@ func (m *Mon) Start() {
} }
// Close closes the monitor.
// Close closes the monitor.
func ( m * Mon ) Close ( ) error { func ( m * Mon itor ) Close ( ) error {
m . mu . Lock ( )
m . mu . Lock ( )
if m . closed {
if m . closed {
m . mu . Unlock ( )
m . mu . Unlock ( )
@ -218,7 +223,7 @@ func (m *Mon) Close() error {
// change and re-check the state of the network. Any registered
// change and re-check the state of the network. Any registered
// ChangeFunc callbacks will be called within the event coalescing
// ChangeFunc callbacks will be called within the event coalescing
// period (under a fraction of a second).
// period (under a fraction of a second).
func ( m * Mon ) InjectEvent ( ) { func ( m * Mon itor ) InjectEvent ( ) {
select {
select {
case m . change <- struct { } { } :
case m . change <- struct { } { } :
default :
default :
@ -228,7 +233,7 @@ func (m *Mon) InjectEvent() {
}
}
} }
func ( m * Mon ) stopped ( ) bool { func ( m * Mon itor ) stopped ( ) bool {
select {
select {
case <- m . stop :
case <- m . stop :
return true
return true
@ -239,7 +244,7 @@ func (m *Mon) stopped() bool {
// pump continuously retrieves messages from the connection, notifying
// pump continuously retrieves messages from the connection, notifying
// the change channel of changes, and stopping when a stop is issued.
// the change channel of changes, and stopping when a stop is issued.
func ( m * Mon ) pump ( ) { func ( m * Mon itor ) pump ( ) {
defer m . goroutines . Done ( )
defer m . goroutines . Done ( )
for ! m . stopped ( ) {
for ! m . stopped ( ) {
msg , err := m . om . Receive ( )
msg , err := m . om . Receive ( )
@ -263,7 +268,7 @@ func (m *Mon) pump() {
}
}
} }
func ( m * Mon ) notifyRuleDeleted ( rdm ipRuleDeletedMessage ) { func ( m * Mon itor ) notifyRuleDeleted ( rdm ipRuleDeletedMessage ) {
m . mu . Lock ( )
m . mu . Lock ( )
defer m . mu . Unlock ( )
defer m . mu . Unlock ( )
for _ , cb := range m . ruleDelCB {
for _ , cb := range m . ruleDelCB {
@ -274,13 +279,13 @@ func (m *Mon) notifyRuleDeleted(rdm ipRuleDeletedMessage) {
// isInterestingInterface reports whether the provided interface should be
// isInterestingInterface reports whether the provided interface should be
// considered when checking for network state changes.
// considered when checking for network state changes.
// The ips parameter should be the IPs of the provided interface.
// The ips parameter should be the IPs of the provided interface.
func ( m * Mon ) isInterestingInterface ( i interfaces . Interface , ips [ ] netip . Prefix ) bool { func ( m * Mon itor ) isInterestingInterface ( i interfaces . Interface , ips [ ] netip . Prefix ) bool {
return m . om . IsInterestingInterface ( i . Name ) && interfaces . UseInterestingInterfaces ( i , ips )
return m . om . IsInterestingInterface ( i . Name ) && interfaces . UseInterestingInterfaces ( i , ips )
} }
// debounce calls the callback function with a delay between events
// debounce calls the callback function with a delay between events
// and exits when a stop is issued.
// and exits when a stop is issued.
func ( m * Mon ) debounce ( ) { func ( m * Mon itor ) debounce ( ) {
defer m . goroutines . Done ( )
defer m . goroutines . Done ( )
for {
for {
select {
select {
@ -343,7 +348,7 @@ func wallTime() time.Time {
return time . Now ( ) . Round ( 0 )
return time . Now ( ) . Round ( 0 )
} }
func ( m * Mon ) pollWallTime ( ) { func ( m * Mon itor ) pollWallTime ( ) {
m . mu . Lock ( )
m . mu . Lock ( )
defer m . mu . Unlock ( )
defer m . mu . Unlock ( )
if m . closed {
if m . closed {
@ -365,7 +370,7 @@ const shouldMonitorTimeJump = runtime.GOOS != "android" && runtime.GOOS != "ios"
// checkWallTimeAdvanceLocked reports whether wall time jumped more than 150% of
// checkWallTimeAdvanceLocked reports whether wall time jumped more than 150% of
// pollWallTimeInterval, indicating we probably just came out of sleep. Once a
// pollWallTimeInterval, indicating we probably just came out of sleep. Once a
// time jump is detected it must be reset by calling resetTimeJumpedLocked.
// time jump is detected it must be reset by calling resetTimeJumpedLocked.
func ( m * Mon ) checkWallTimeAdvanceLocked ( ) bool { func ( m * Mon itor ) checkWallTimeAdvanceLocked ( ) bool {
if ! shouldMonitorTimeJump {
if ! shouldMonitorTimeJump {
panic ( "unreachable" ) // if callers are correct
panic ( "unreachable" ) // if callers are correct
}
}
@ -378,7 +383,7 @@ func (m *Mon) checkWallTimeAdvanceLocked() bool {
} }
// resetTimeJumpedLocked consumes the signal set by checkWallTimeAdvanceLocked.
// resetTimeJumpedLocked consumes the signal set by checkWallTimeAdvanceLocked.
func ( m * Mon ) resetTimeJumpedLocked ( ) { func ( m * Mon itor ) resetTimeJumpedLocked ( ) {
m . timeJumped = false
m . timeJumped = false
} }
Mihai Parparita
1 year ago
committed by