diff options
author | gVisor bot <gvisor-bot@google.com> | 2020-10-23 17:35:54 +0000 |
---|---|---|
committer | gVisor bot <gvisor-bot@google.com> | 2020-10-23 17:35:54 +0000 |
commit | addf7ba2386b07677892262caede551b90bedcb2 (patch) | |
tree | e2284fd85914b626a424f35f02ff7c461438cbf7 | |
parent | 4a0325975468d668e94d5c536bd6f1ba5f554fe1 (diff) | |
parent | dad08229b80bbdca62f12a79ce8bf3b07cb31347 (diff) |
Merge release-20201019.0-36-gdad08229b (automated)
-rw-r--r-- | pkg/tcpip/network/arp/arp.go | 25 | ||||
-rw-r--r-- | pkg/tcpip/network/ipv6/icmp.go | 6 | ||||
-rw-r--r-- | pkg/tcpip/stack/neighbor_cache.go | 19 | ||||
-rw-r--r-- | pkg/tcpip/stack/neighbor_entry.go | 116 | ||||
-rw-r--r-- | pkg/tcpip/stack/nud.go | 2 |
5 files changed, 99 insertions, 69 deletions
diff --git a/pkg/tcpip/network/arp/arp.go b/pkg/tcpip/network/arp/arp.go index d8174e8f7..a79379abb 100644 --- a/pkg/tcpip/network/arp/arp.go +++ b/pkg/tcpip/network/arp/arp.go @@ -151,7 +151,7 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) { remoteAddr := tcpip.Address(h.ProtocolAddressSender()) remoteLinkAddr := tcpip.LinkAddress(h.HardwareAddressSender()) - e.nud.HandleProbe(remoteAddr, localAddr, ProtocolNumber, remoteLinkAddr, e.protocol) + e.nud.HandleProbe(remoteAddr, ProtocolNumber, remoteLinkAddr, e.protocol) } respPkt := stack.NewPacketBuffer(stack.PacketBufferOptions{ @@ -208,6 +208,7 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) { // protocol implements stack.NetworkProtocol and stack.LinkAddressResolver. type protocol struct { + stack *stack.Stack } func (p *protocol) Number() tcpip.NetworkProtocolNumber { return ProtocolNumber } @@ -236,11 +237,27 @@ func (*protocol) LinkAddressProtocol() tcpip.NetworkProtocolNumber { } // LinkAddressRequest implements stack.LinkAddressResolver.LinkAddressRequest. -func (*protocol) LinkAddressRequest(targetAddr, localAddr tcpip.Address, remoteLinkAddr tcpip.LinkAddress, nic stack.NetworkInterface) *tcpip.Error { +func (p *protocol) LinkAddressRequest(targetAddr, localAddr tcpip.Address, remoteLinkAddr tcpip.LinkAddress, nic stack.NetworkInterface) *tcpip.Error { if len(remoteLinkAddr) == 0 { remoteLinkAddr = header.EthernetBroadcastAddress } + nicID := nic.ID() + if len(localAddr) == 0 { + addr, err := p.stack.GetMainNICAddress(nicID, header.IPv4ProtocolNumber) + if err != nil { + return err + } + + if len(addr.Address) == 0 { + return tcpip.ErrNetworkUnreachable + } + + localAddr = addr.Address + } else if p.stack.CheckLocalAddress(nicID, header.IPv4ProtocolNumber, localAddr) == 0 { + return tcpip.ErrBadLocalAddress + } + pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{ ReserveHeaderBytes: int(nic.MaxHeaderLength()) + header.ARPSize, }) @@ -297,6 +314,6 @@ func (*protocol) Parse(pkt *stack.PacketBuffer) (proto tcpip.TransportProtocolNu // Note, to make sure that the ARP endpoint receives ARP packets, the "arp" // address must be added to every NIC that should respond to ARP requests. See // ProtocolAddress for more details. -func NewProtocol(*stack.Stack) stack.NetworkProtocol { - return &protocol{} +func NewProtocol(s *stack.Stack) stack.NetworkProtocol { + return &protocol{stack: s} } diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go index fa6c3787b..b10249c9e 100644 --- a/pkg/tcpip/network/ipv6/icmp.go +++ b/pkg/tcpip/network/ipv6/icmp.go @@ -287,7 +287,7 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer, hasFragme received.Invalid.Increment() return } else if e.nud != nil { - e.nud.HandleProbe(r.RemoteAddress, r.LocalAddress, header.IPv6ProtocolNumber, sourceLinkAddr, e.protocol) + e.nud.HandleProbe(r.RemoteAddress, header.IPv6ProtocolNumber, sourceLinkAddr, e.protocol) } else { e.linkAddrCache.AddLinkAddress(e.nic.ID(), r.RemoteAddress, sourceLinkAddr) } @@ -558,7 +558,7 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer, hasFragme if e.nud != nil { // A RS with a specified source IP address modifies the NUD state // machine in the same way a reachability probe would. - e.nud.HandleProbe(r.RemoteAddress, r.LocalAddress, header.IPv6ProtocolNumber, sourceLinkAddr, e.protocol) + e.nud.HandleProbe(r.RemoteAddress, header.IPv6ProtocolNumber, sourceLinkAddr, e.protocol) } } @@ -608,7 +608,7 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer, hasFragme // If the RA has the source link layer option, update the link address // cache with the link address for the advertised router. if len(sourceLinkAddr) != 0 && e.nud != nil { - e.nud.HandleProbe(routerAddr, r.LocalAddress, header.IPv6ProtocolNumber, sourceLinkAddr, e.protocol) + e.nud.HandleProbe(routerAddr, header.IPv6ProtocolNumber, sourceLinkAddr, e.protocol) } e.mu.Lock() diff --git a/pkg/tcpip/stack/neighbor_cache.go b/pkg/tcpip/stack/neighbor_cache.go index 4df288798..02882bf19 100644 --- a/pkg/tcpip/stack/neighbor_cache.go +++ b/pkg/tcpip/stack/neighbor_cache.go @@ -68,7 +68,7 @@ var _ NUDHandler = (*neighborCache)(nil) // reset to state incomplete, and returned. If no matching entry exists and the // cache is not full, a new entry with state incomplete is allocated and // returned. -func (n *neighborCache) getOrCreateEntry(remoteAddr, localAddr tcpip.Address, linkRes LinkAddressResolver) *neighborEntry { +func (n *neighborCache) getOrCreateEntry(remoteAddr tcpip.Address, linkRes LinkAddressResolver) *neighborEntry { n.mu.Lock() defer n.mu.Unlock() @@ -84,7 +84,7 @@ func (n *neighborCache) getOrCreateEntry(remoteAddr, localAddr tcpip.Address, li // The entry that needs to be created must be dynamic since all static // entries are directly added to the cache via addStaticEntry. - entry := newNeighborEntry(n.nic, remoteAddr, localAddr, n.state, linkRes) + entry := newNeighborEntry(n.nic, remoteAddr, n.state, linkRes) if n.dynamic.count == neighborCacheSize { e := n.dynamic.lru.Back() e.mu.Lock() @@ -111,6 +111,10 @@ func (n *neighborCache) getOrCreateEntry(remoteAddr, localAddr tcpip.Address, li // provided, it will be notified when address resolution is complete (success // or not). // +// If specified, the local address must be an address local to the interface the +// neighbor cache belongs to. The local address is the source address of a +// packet prompting NUD/link address resolution. +// // If address resolution is required, ErrNoLinkAddress and a notification // channel is returned for the top level caller to block. Channel is closed // once address resolution is complete (success or not). @@ -118,7 +122,6 @@ func (n *neighborCache) entry(remoteAddr, localAddr tcpip.Address, linkRes LinkA if linkAddr, ok := linkRes.ResolveStaticAddress(remoteAddr); ok { e := NeighborEntry{ Addr: remoteAddr, - LocalAddr: localAddr, LinkAddr: linkAddr, State: Static, UpdatedAt: time.Now(), @@ -126,13 +129,13 @@ func (n *neighborCache) entry(remoteAddr, localAddr tcpip.Address, linkRes LinkA return e, nil, nil } - entry := n.getOrCreateEntry(remoteAddr, localAddr, linkRes) + entry := n.getOrCreateEntry(remoteAddr, linkRes) entry.mu.Lock() defer entry.mu.Unlock() switch s := entry.neigh.State; s { case Stale: - entry.handlePacketQueuedLocked() + entry.handlePacketQueuedLocked(localAddr) fallthrough case Reachable, Static, Delay, Probe: // As per RFC 4861 section 7.3.3: @@ -152,7 +155,7 @@ func (n *neighborCache) entry(remoteAddr, localAddr tcpip.Address, linkRes LinkA entry.done = make(chan struct{}) } - entry.handlePacketQueuedLocked() + entry.handlePacketQueuedLocked(localAddr) return entry.neigh, entry.done, tcpip.ErrWouldBlock case Failed: return entry.neigh, nil, tcpip.ErrNoLinkAddress @@ -292,8 +295,8 @@ func (n *neighborCache) setConfig(config NUDConfigurations) { // HandleProbe implements NUDHandler.HandleProbe by following the logic defined // in RFC 4861 section 7.2.3. Validation of the probe is expected to be handled // by the caller. -func (n *neighborCache) HandleProbe(remoteAddr, localAddr tcpip.Address, protocol tcpip.NetworkProtocolNumber, remoteLinkAddr tcpip.LinkAddress, linkRes LinkAddressResolver) { - entry := n.getOrCreateEntry(remoteAddr, localAddr, linkRes) +func (n *neighborCache) HandleProbe(remoteAddr tcpip.Address, protocol tcpip.NetworkProtocolNumber, remoteLinkAddr tcpip.LinkAddress, linkRes LinkAddressResolver) { + entry := n.getOrCreateEntry(remoteAddr, linkRes) entry.mu.Lock() entry.handleProbeLocked(remoteLinkAddr) entry.mu.Unlock() 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) diff --git a/pkg/tcpip/stack/nud.go b/pkg/tcpip/stack/nud.go index e1ec15487..cb234caf4 100644 --- a/pkg/tcpip/stack/nud.go +++ b/pkg/tcpip/stack/nud.go @@ -177,7 +177,7 @@ type NUDHandler interface { // Neighbor Solicitation for ARP or NDP, respectively). Validation of the // probe needs to be performed before calling this function since the // Neighbor Cache doesn't have access to view the NIC's assigned addresses. - HandleProbe(remoteAddr, localAddr tcpip.Address, protocol tcpip.NetworkProtocolNumber, remoteLinkAddr tcpip.LinkAddress, linkRes LinkAddressResolver) + HandleProbe(remoteAddr tcpip.Address, protocol tcpip.NetworkProtocolNumber, remoteLinkAddr tcpip.LinkAddress, linkRes LinkAddressResolver) // HandleConfirmation processes an incoming neighbor confirmation (e.g. ARP // reply or Neighbor Advertisement for ARP or NDP, respectively). |