diff options
Diffstat (limited to 'pkg/tcpip/stack/neighbor_entry.go')
| -rw-r--r-- | pkg/tcpip/stack/neighbor_entry.go | 116 |
1 files changed, 63 insertions, 53 deletions
diff --git a/pkg/tcpip/stack/neighbor_entry.go b/pkg/tcpip/stack/neighbor_entry.go index ab3cf6e9d..0f16feaa5 100644 --- a/pkg/tcpip/stack/neighbor_entry.go +++ b/pkg/tcpip/stack/neighbor_entry.go @@ -27,7 +27,6 @@ import ( // NeighborEntry describes a neighboring device in the local network. type NeighborEntry struct { Addr tcpip.Address - LocalAddr tcpip.Address LinkAddr tcpip.LinkAddress State NeighborState UpdatedAt time.Time @@ -106,15 +105,14 @@ type neighborEntry struct { // state, Unknown. Transition out of Unknown by calling either // `handlePacketQueuedLocked` or `handleProbeLocked` on the newly created // neighborEntry. -func newNeighborEntry(nic *NIC, remoteAddr tcpip.Address, localAddr tcpip.Address, nudState *NUDState, linkRes LinkAddressResolver) *neighborEntry { +func newNeighborEntry(nic *NIC, remoteAddr tcpip.Address, nudState *NUDState, linkRes LinkAddressResolver) *neighborEntry { return &neighborEntry{ nic: nic, linkRes: linkRes, nudState: nudState, neigh: NeighborEntry{ - Addr: remoteAddr, - LocalAddr: localAddr, - State: Unknown, + Addr: remoteAddr, + State: Unknown, }, } } @@ -206,51 +204,7 @@ func (e *neighborEntry) setStateLocked(next NeighborState) { switch next { case Incomplete: - var retryCounter uint32 - var sendMulticastProbe func() - - sendMulticastProbe = func() { - if retryCounter == config.MaxMulticastProbes { - // "If no Neighbor Advertisement is received after - // MAX_MULTICAST_SOLICIT solicitations, address resolution has failed. - // The sender MUST return ICMP destination unreachable indications with - // code 3 (Address Unreachable) for each packet queued awaiting address - // resolution." - RFC 4861 section 7.2.2 - // - // There is no need to send an ICMP destination unreachable indication - // since the failure to resolve the address is expected to only occur - // on this node. Thus, redirecting traffic is currently not supported. - // - // "If the error occurs on a node other than the node originating the - // packet, an ICMP error message is generated. If the error occurs on - // the originating node, an implementation is not required to actually - // create and send an ICMP error packet to the source, as long as the - // upper-layer sender is notified through an appropriate mechanism - // (e.g. return value from a procedure call). Note, however, that an - // implementation may find it convenient in some cases to return errors - // to the sender by taking the offending packet, generating an ICMP - // error message, and then delivering it (locally) through the generic - // error-handling routines.' - RFC 4861 section 2.1 - e.dispatchRemoveEventLocked() - e.setStateLocked(Failed) - return - } - - if err := e.linkRes.LinkAddressRequest(e.neigh.Addr, e.neigh.LocalAddr, "", e.nic); err != nil { - // There is no need to log the error here; the NUD implementation may - // assume a working link. A valid link should be the responsibility of - // the NIC/stack.LinkEndpoint. - e.dispatchRemoveEventLocked() - e.setStateLocked(Failed) - return - } - - retryCounter++ - e.job = e.nic.stack.newJob(&e.mu, sendMulticastProbe) - e.job.Schedule(config.RetransmitTimer) - } - - sendMulticastProbe() + panic(fmt.Sprintf("should never transition to Incomplete with setStateLocked; neigh = %#v, prev state = %s", e.neigh, prev)) case Reachable: e.job = e.nic.stack.newJob(&e.mu, func() { @@ -277,7 +231,7 @@ func (e *neighborEntry) setStateLocked(next NeighborState) { return } - if err := e.linkRes.LinkAddressRequest(e.neigh.Addr, e.neigh.LocalAddr, e.neigh.LinkAddr, e.nic); err != nil { + if err := e.linkRes.LinkAddressRequest(e.neigh.Addr, "" /* localAddr */, e.neigh.LinkAddr, e.nic); err != nil { e.dispatchRemoveEventLocked() e.setStateLocked(Failed) return @@ -315,11 +269,67 @@ func (e *neighborEntry) setStateLocked(next NeighborState) { // being queued for outgoing transmission. // // Follows the logic defined in RFC 4861 section 7.3.3. -func (e *neighborEntry) handlePacketQueuedLocked() { +func (e *neighborEntry) handlePacketQueuedLocked(localAddr tcpip.Address) { switch e.neigh.State { case Unknown: e.dispatchAddEventLocked(Incomplete) - e.setStateLocked(Incomplete) + + e.neigh.State = Incomplete + e.neigh.UpdatedAt = time.Now() + config := e.nudState.Config() + + var retryCounter uint32 + var sendMulticastProbe func() + + sendMulticastProbe = func() { + if retryCounter == config.MaxMulticastProbes { + // "If no Neighbor Advertisement is received after + // MAX_MULTICAST_SOLICIT solicitations, address resolution has failed. + // The sender MUST return ICMP destination unreachable indications with + // code 3 (Address Unreachable) for each packet queued awaiting address + // resolution." - RFC 4861 section 7.2.2 + // + // There is no need to send an ICMP destination unreachable indication + // since the failure to resolve the address is expected to only occur + // on this node. Thus, redirecting traffic is currently not supported. + // + // "If the error occurs on a node other than the node originating the + // packet, an ICMP error message is generated. If the error occurs on + // the originating node, an implementation is not required to actually + // create and send an ICMP error packet to the source, as long as the + // upper-layer sender is notified through an appropriate mechanism + // (e.g. return value from a procedure call). Note, however, that an + // implementation may find it convenient in some cases to return errors + // to the sender by taking the offending packet, generating an ICMP + // error message, and then delivering it (locally) through the generic + // error-handling routines.' - RFC 4861 section 2.1 + e.dispatchRemoveEventLocked() + e.setStateLocked(Failed) + return + } + + // As per RFC 4861 section 7.2.2: + // + // If the source address of the packet prompting the solicitation is the + // same as one of the addresses assigned to the outgoing interface, that + // address SHOULD be placed in the IP Source Address of the outgoing + // solicitation. + // + if err := e.linkRes.LinkAddressRequest(e.neigh.Addr, localAddr, "", e.nic); err != nil { + // There is no need to log the error here; the NUD implementation may + // assume a working link. A valid link should be the responsibility of + // the NIC/stack.LinkEndpoint. + e.dispatchRemoveEventLocked() + e.setStateLocked(Failed) + return + } + + retryCounter++ + e.job = e.nic.stack.newJob(&e.mu, sendMulticastProbe) + e.job.Schedule(config.RetransmitTimer) + } + + sendMulticastProbe() case Stale: e.dispatchChangeEventLocked(Delay) |