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Diffstat (limited to 'pkg/tcpip/stack/ndp.go')
-rw-r--r--pkg/tcpip/stack/ndp.go100
1 files changed, 74 insertions, 26 deletions
diff --git a/pkg/tcpip/stack/ndp.go b/pkg/tcpip/stack/ndp.go
index 526c7d6ff..e28c23d66 100644
--- a/pkg/tcpip/stack/ndp.go
+++ b/pkg/tcpip/stack/ndp.go
@@ -467,8 +467,17 @@ type ndpState struct {
// The default routers discovered through Router Advertisements.
defaultRouters map[tcpip.Address]defaultRouterState
- // The timer used to send the next router solicitation message.
- rtrSolicitTimer *time.Timer
+ rtrSolicit struct {
+ // The timer used to send the next router solicitation message.
+ timer *time.Timer
+
+ // Used to let the Router Solicitation timer know that it has been stopped.
+ //
+ // Must only be read from or written to while protected by the lock of
+ // the NIC this ndpState is associated with. MUST be set when the timer is
+ // set.
+ done *bool
+ }
// The on-link prefixes discovered through Router Advertisements' Prefix
// Information option.
@@ -648,13 +657,14 @@ func (ndp *ndpState) startDuplicateAddressDetection(addr tcpip.Address, ref *ref
// as starting a goroutine but we use a timer that fires immediately so we can
// reset it for the next DAD iteration.
timer = time.AfterFunc(0, func() {
- ndp.nic.mu.RLock()
+ ndp.nic.mu.Lock()
+ defer ndp.nic.mu.Unlock()
+
if done {
// If we reach this point, it means that the DAD timer fired after
// another goroutine already obtained the NIC lock and stopped DAD
// before this function obtained the NIC lock. Simply return here and do
// nothing further.
- ndp.nic.mu.RUnlock()
return
}
@@ -665,15 +675,23 @@ func (ndp *ndpState) startDuplicateAddressDetection(addr tcpip.Address, ref *ref
}
dadDone := remaining == 0
- ndp.nic.mu.RUnlock()
var err *tcpip.Error
if !dadDone {
- err = ndp.sendDADPacket(addr)
+ // Use the unspecified address as the source address when performing DAD.
+ ref := ndp.nic.getRefOrCreateTempLocked(header.IPv6ProtocolNumber, header.IPv6Any, NeverPrimaryEndpoint)
+
+ // Do not hold the lock when sending packets which may be a long running
+ // task or may block link address resolution. We know this is safe
+ // because immediately after obtaining the lock again, we check if DAD
+ // has been stopped before doing any work with the NIC. Note, DAD would be
+ // stopped if the NIC was disabled or removed, or if the address was
+ // removed.
+ ndp.nic.mu.Unlock()
+ err = ndp.sendDADPacket(addr, ref)
+ ndp.nic.mu.Lock()
}
- ndp.nic.mu.Lock()
- defer ndp.nic.mu.Unlock()
if done {
// If we reach this point, it means that DAD was stopped after we released
// the NIC's read lock and before we obtained the write lock.
@@ -721,17 +739,24 @@ func (ndp *ndpState) startDuplicateAddressDetection(addr tcpip.Address, ref *ref
// addr.
//
// addr must be a tentative IPv6 address on ndp's NIC.
-func (ndp *ndpState) sendDADPacket(addr tcpip.Address) *tcpip.Error {
+//
+// The NIC ndp belongs to MUST NOT be locked.
+func (ndp *ndpState) sendDADPacket(addr tcpip.Address, ref *referencedNetworkEndpoint) *tcpip.Error {
snmc := header.SolicitedNodeAddr(addr)
- // Use the unspecified address as the source address when performing DAD.
- ref := ndp.nic.getRefOrCreateTemp(header.IPv6ProtocolNumber, header.IPv6Any, NeverPrimaryEndpoint, forceSpoofing)
- r := makeRoute(header.IPv6ProtocolNumber, header.IPv6Any, snmc, ndp.nic.linkEP.LinkAddress(), ref, false, false)
+ r := makeRoute(header.IPv6ProtocolNumber, ref.ep.ID().LocalAddress, snmc, ndp.nic.linkEP.LinkAddress(), ref, false, false)
defer r.Release()
// Route should resolve immediately since snmc is a multicast address so a
// remote link address can be calculated without a resolution process.
if c, err := r.Resolve(nil); err != nil {
+ // Do not consider the NIC being unknown or disabled as a fatal error.
+ // Since this method is required to be called when the NIC is not locked,
+ // the NIC could have been disabled or removed by another goroutine.
+ if err == tcpip.ErrUnknownNICID || err != tcpip.ErrInvalidEndpointState {
+ return err
+ }
+
panic(fmt.Sprintf("ndp: error when resolving route to send NDP NS for DAD (%s -> %s on NIC(%d)): %s", header.IPv6Any, snmc, ndp.nic.ID(), err))
} else if c != nil {
panic(fmt.Sprintf("ndp: route resolution not immediate for route to send NDP NS for DAD (%s -> %s on NIC(%d))", header.IPv6Any, snmc, ndp.nic.ID()))
@@ -750,7 +775,7 @@ func (ndp *ndpState) sendDADPacket(addr tcpip.Address) *tcpip.Error {
Protocol: header.ICMPv6ProtocolNumber,
TTL: header.NDPHopLimit,
TOS: DefaultTOS,
- }, PacketBuffer{Header: hdr},
+ }, &PacketBuffer{Header: hdr},
); err != nil {
sent.Dropped.Increment()
return err
@@ -1816,7 +1841,7 @@ func (ndp *ndpState) cleanupState(hostOnly bool) {
//
// The NIC ndp belongs to MUST be locked.
func (ndp *ndpState) startSolicitingRouters() {
- if ndp.rtrSolicitTimer != nil {
+ if ndp.rtrSolicit.timer != nil {
// We are already soliciting routers.
return
}
@@ -1833,14 +1858,27 @@ func (ndp *ndpState) startSolicitingRouters() {
delay = time.Duration(rand.Int63n(int64(ndp.configs.MaxRtrSolicitationDelay)))
}
- ndp.rtrSolicitTimer = time.AfterFunc(delay, func() {
+ var done bool
+ ndp.rtrSolicit.done = &done
+ ndp.rtrSolicit.timer = time.AfterFunc(delay, func() {
+ ndp.nic.mu.Lock()
+ if done {
+ // If we reach this point, it means that the RS timer fired after another
+ // goroutine already obtained the NIC lock and stopped solicitations.
+ // Simply return here and do nothing further.
+ ndp.nic.mu.Unlock()
+ return
+ }
+
// As per RFC 4861 section 4.1, the source of the RS is an address assigned
// to the sending interface, or the unspecified address if no address is
// assigned to the sending interface.
- ref := ndp.nic.primaryIPv6Endpoint(header.IPv6AllRoutersMulticastAddress)
+ ref := ndp.nic.primaryIPv6EndpointRLocked(header.IPv6AllRoutersMulticastAddress)
if ref == nil {
- ref = ndp.nic.getRefOrCreateTemp(header.IPv6ProtocolNumber, header.IPv6Any, NeverPrimaryEndpoint, forceSpoofing)
+ ref = ndp.nic.getRefOrCreateTempLocked(header.IPv6ProtocolNumber, header.IPv6Any, NeverPrimaryEndpoint)
}
+ ndp.nic.mu.Unlock()
+
localAddr := ref.ep.ID().LocalAddress
r := makeRoute(header.IPv6ProtocolNumber, localAddr, header.IPv6AllRoutersMulticastAddress, ndp.nic.linkEP.LinkAddress(), ref, false, false)
defer r.Release()
@@ -1849,6 +1887,13 @@ func (ndp *ndpState) startSolicitingRouters() {
// header.IPv6AllRoutersMulticastAddress is a multicast address so a
// remote link address can be calculated without a resolution process.
if c, err := r.Resolve(nil); err != nil {
+ // Do not consider the NIC being unknown or disabled as a fatal error.
+ // Since this method is required to be called when the NIC is not locked,
+ // the NIC could have been disabled or removed by another goroutine.
+ if err == tcpip.ErrUnknownNICID || err == tcpip.ErrInvalidEndpointState {
+ return
+ }
+
panic(fmt.Sprintf("ndp: error when resolving route to send NDP RS (%s -> %s on NIC(%d)): %s", header.IPv6Any, header.IPv6AllRoutersMulticastAddress, ndp.nic.ID(), err))
} else if c != nil {
panic(fmt.Sprintf("ndp: route resolution not immediate for route to send NDP RS (%s -> %s on NIC(%d))", header.IPv6Any, header.IPv6AllRoutersMulticastAddress, ndp.nic.ID()))
@@ -1881,7 +1926,7 @@ func (ndp *ndpState) startSolicitingRouters() {
Protocol: header.ICMPv6ProtocolNumber,
TTL: header.NDPHopLimit,
TOS: DefaultTOS,
- }, PacketBuffer{Header: hdr},
+ }, &PacketBuffer{Header: hdr},
); err != nil {
sent.Dropped.Increment()
log.Printf("startSolicitingRouters: error writing NDP router solicit message on NIC(%d); err = %s", ndp.nic.ID(), err)
@@ -1893,17 +1938,18 @@ func (ndp *ndpState) startSolicitingRouters() {
}
ndp.nic.mu.Lock()
- defer ndp.nic.mu.Unlock()
- if remaining == 0 {
- ndp.rtrSolicitTimer = nil
- } else if ndp.rtrSolicitTimer != nil {
+ if done || remaining == 0 {
+ ndp.rtrSolicit.timer = nil
+ ndp.rtrSolicit.done = nil
+ } else if ndp.rtrSolicit.timer != nil {
// Note, we need to explicitly check to make sure that
// the timer field is not nil because if it was nil but
// we still reached this point, then we know the NIC
// was requested to stop soliciting routers so we don't
// need to send the next Router Solicitation message.
- ndp.rtrSolicitTimer.Reset(ndp.configs.RtrSolicitationInterval)
+ ndp.rtrSolicit.timer.Reset(ndp.configs.RtrSolicitationInterval)
}
+ ndp.nic.mu.Unlock()
})
}
@@ -1913,13 +1959,15 @@ func (ndp *ndpState) startSolicitingRouters() {
//
// The NIC ndp belongs to MUST be locked.
func (ndp *ndpState) stopSolicitingRouters() {
- if ndp.rtrSolicitTimer == nil {
+ if ndp.rtrSolicit.timer == nil {
// Nothing to do.
return
}
- ndp.rtrSolicitTimer.Stop()
- ndp.rtrSolicitTimer = nil
+ *ndp.rtrSolicit.done = true
+ ndp.rtrSolicit.timer.Stop()
+ ndp.rtrSolicit.timer = nil
+ ndp.rtrSolicit.done = nil
}
// initializeTempAddrState initializes state related to temporary SLAAC
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-18 17:51:32 +0000