@ -119,6 +119,7 @@ type userspaceEngine struct {
statusBufioReader * bufio . Reader // reusable for UAPI
mu sync . Mutex // guards following; see lock order comment below
netMap * netmap . NetworkMap // or nil
closing bool // Close was called (even if we're still closing)
statusCallback StatusCallback
peerSequence [ ] wgkey . Key
@ -1307,6 +1308,7 @@ func (e *userspaceEngine) SetDERPMap(dm *tailcfg.DERPMap) {
func ( e * userspaceEngine ) SetNetworkMap ( nm * netmap . NetworkMap ) {
e . magicConn . SetNetworkMap ( nm )
e . mu . Lock ( )
e . netMap = nm
callbacks := make ( [ ] NetworkMapCallback , 0 , 4 )
for _ , fn := range e . networkMapCallbacks {
callbacks = append ( callbacks , fn )
@ -1340,7 +1342,18 @@ func (e *userspaceEngine) UpdateStatus(sb *ipnstate.StatusBuilder) {
}
func ( e * userspaceEngine ) Ping ( ip netaddr . IP , cb func ( * ipnstate . PingResult ) ) {
e . magicConn . Ping ( ip , cb )
res := & ipnstate . PingResult { IP : ip . String ( ) }
peer , err := e . peerForIP ( ip )
if err != nil {
res . Err = err . Error ( )
cb ( res )
}
if peer == nil {
res . Err = "no matching peer"
cb ( res )
return
}
e . magicConn . Ping ( peer , res , cb )
}
func ( e * userspaceEngine ) RegisterIPPortIdentity ( ipport netaddr . IPPort , tsIP netaddr . IP ) {
@ -1368,6 +1381,79 @@ func (e *userspaceEngine) WhoIsIPPort(ipport netaddr.IPPort) (tsIP netaddr.IP, o
return tsIP , ok
}
// peerForIP returns the Node in the wireguard config
// that's responsible for handling the given IP address.
//
// If none is found in the wireguard config but one is found in
// the netmap, it's described in an error.
//
// If none is found in either place, (nil, nil) is returned.
//
// peerForIP acquires both e.mu and e.wgLock, but neither at the same
// time.
func ( e * userspaceEngine ) peerForIP ( ip netaddr . IP ) ( n * tailcfg . Node , err error ) {
e . mu . Lock ( )
nm := e . netMap
e . mu . Unlock ( )
if nm == nil {
return nil , errors . New ( "no network map" )
}
// Check for exact matches before looking for subnet matches.
var bestInNMPrefix netaddr . IPPrefix
var bestInNM * tailcfg . Node
for _ , p := range nm . Peers {
for _ , a := range p . Addresses {
if a . IP == ip && a . IsSingleIP ( ) && tsaddr . IsTailscaleIP ( ip ) {
return p , nil
}
}
for _ , cidr := range p . AllowedIPs {
if ! cidr . Contains ( ip ) {
continue
}
if bestInNMPrefix . IsZero ( ) || cidr . Bits > bestInNMPrefix . Bits {
bestInNMPrefix = cidr
bestInNM = p
}
}
}
e . wgLock . Lock ( )
defer e . wgLock . Unlock ( )
// TODO(bradfitz): this is O(n peers). Add ART to netaddr?
var best netaddr . IPPrefix
var bestKey tailcfg . NodeKey
for _ , p := range e . lastCfgFull . Peers {
for _ , cidr := range p . AllowedIPs {
if ! cidr . Contains ( ip ) {
continue
}
if best . IsZero ( ) || cidr . Bits > best . Bits {
best = cidr
bestKey = tailcfg . NodeKey ( p . PublicKey )
}
}
}
// And another pass. Probably better than allocating a map per peerForIP
// call. But TODO(bradfitz): add a lookup map to netmap.NetworkMap.
if ! bestKey . IsZero ( ) {
for _ , p := range nm . Peers {
if p . Key == bestKey {
return p , nil
}
}
}
if bestInNM == nil {
return nil , nil
}
if bestInNMPrefix . Bits == 0 {
return nil , errors . New ( "exit node found but not enabled" )
}
return nil , fmt . Errorf ( "node %q found, but not using its %v route" , bestInNM . ComputedNameWithHost , bestInNMPrefix )
}
// diagnoseTUNFailure is called if tun.CreateTUN fails, to poke around
// the system and log some diagnostic info that might help debug why
// TUN failed. Because TUN's already failed and things the program's
Brad Fitzpatrick
4 years ago