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-rw-r--r--pkg/tcpip/stack/neighbor_cache.go19
-rw-r--r--pkg/tcpip/stack/neighbor_entry.go116
-rw-r--r--pkg/tcpip/stack/nud.go2
3 files changed, 75 insertions, 62 deletions
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).
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-05 01:09:48 +0000