diff options
| -rw-r--r-- | pkg/sentry/socket/netstack/netstack.go | 3 | ||||
| -rw-r--r-- | pkg/tcpip/network/internal/ip/stats.go | 5 | ||||
| -rw-r--r-- | pkg/tcpip/network/ipv4/icmp.go | 27 | ||||
| -rw-r--r-- | pkg/tcpip/network/ipv4/ipv4.go | 10 | ||||
| -rw-r--r-- | pkg/tcpip/network/ipv6/icmp.go | 31 | ||||
| -rw-r--r-- | pkg/tcpip/network/ipv6/ipv6.go | 10 | ||||
| -rw-r--r-- | pkg/tcpip/stack/neighbor_entry.go | 4 | ||||
| -rw-r--r-- | pkg/tcpip/tcpip.go | 4 |
8 files changed, 89 insertions, 5 deletions
diff --git a/pkg/sentry/socket/netstack/netstack.go b/pkg/sentry/socket/netstack/netstack.go index 0b64a24c3..335284f50 100644 --- a/pkg/sentry/socket/netstack/netstack.go +++ b/pkg/sentry/socket/netstack/netstack.go @@ -205,7 +205,8 @@ var Metrics = tcpip.Stats{ LinkLocalSource: mustCreateMetric("/netstack/ip/forwarding/link_local_source_address", "Number of IP packets received which could not be forwarded due to a link-local source address."), LinkLocalDestination: mustCreateMetric("/netstack/ip/forwarding/link_local_destination_address", "Number of IP packets received which could not be forwarded due to a link-local destination address."), ExtensionHeaderProblem: mustCreateMetric("/netstack/ip/forwarding/extension_header_problem", "Number of IP packets received which could not be forwarded due to a problem processing their IPv6 extension headers."), - PacketTooBig: mustCreateMetric("/netstack/ip/forwarding/packet_too_big", "Number of IP packets received which could not fit within the outgoing MTU."), + PacketTooBig: mustCreateMetric("/netstack/ip/forwarding/packet_too_big", "Number of IP packets received which could not be forwarded because they could not fit within the outgoing MTU."), + HostUnreachable: mustCreateMetric("/netstack/ip/forwarding/host_unreachable", "Number of IP packets received which could not be forwarded due to unresolvable next hop."), Errors: mustCreateMetric("/netstack/ip/forwarding/errors", "Number of IP packets which couldn't be forwarded."), }, }, diff --git a/pkg/tcpip/network/internal/ip/stats.go b/pkg/tcpip/network/internal/ip/stats.go index 0c2b62127..40ab21cb6 100644 --- a/pkg/tcpip/network/internal/ip/stats.go +++ b/pkg/tcpip/network/internal/ip/stats.go @@ -42,6 +42,10 @@ type MultiCounterIPForwardingStats struct { // were too big for the outgoing MTU. PacketTooBig tcpip.MultiCounterStat + // HostUnreachable is the number of IP packets received which could not be + // successfully forwarded due to an unresolvable next hop. + HostUnreachable tcpip.MultiCounterStat + // ExtensionHeaderProblem is the number of IP packets which were dropped // because of a problem encountered when processing an IPv6 extension // header. @@ -61,6 +65,7 @@ func (m *MultiCounterIPForwardingStats) Init(a, b *tcpip.IPForwardingStats) { m.ExtensionHeaderProblem.Init(a.ExtensionHeaderProblem, b.ExtensionHeaderProblem) m.PacketTooBig.Init(a.PacketTooBig, b.PacketTooBig) m.ExhaustedTTL.Init(a.ExhaustedTTL, b.ExhaustedTTL) + m.HostUnreachable.Init(a.HostUnreachable, b.HostUnreachable) } // LINT.ThenChange(:MultiCounterIPForwardingStats, ../../../tcpip.go:IPForwardingStats) diff --git a/pkg/tcpip/network/ipv4/icmp.go b/pkg/tcpip/network/ipv4/icmp.go index d1a82b584..8e27a6677 100644 --- a/pkg/tcpip/network/ipv4/icmp.go +++ b/pkg/tcpip/network/ipv4/icmp.go @@ -481,6 +481,22 @@ func (*icmpReasonFragmentationNeeded) isForwarding() bool { return true } +// icmpReasonHostUnreachable is an error in which the host specified in the +// internet destination field of the datagram is unreachable. +type icmpReasonHostUnreachable struct{} + +func (*icmpReasonHostUnreachable) isICMPReason() {} +func (*icmpReasonHostUnreachable) isForwarding() bool { + // If we hit a Host Unreachable error, then we know we are operating as a + // router. As per RFC 792 page 5, Destination Unreachable Message, + // + // In addition, in some networks, the gateway may be able to determine + // if the internet destination host is unreachable. Gateways in these + // networks may send destination unreachable messages to the source host + // when the destination host is unreachable. + return true +} + // returnError takes an error descriptor and generates the appropriate ICMP // error packet for IPv4 and sends it back to the remote device that sent // the problematic packet. It incorporates as much of that packet as @@ -537,7 +553,12 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip defer route.Release() p.mu.Lock() - netEP, ok := p.mu.eps[pkt.NICID] + // We retrieve an endpoint using the newly constructed route's NICID rather + // than the packet's NICID. The packet's NICID corresponds to the NIC on + // which it arrived, which isn't necessarily the same as the NIC on which it + // will be transmitted. On the other hand, the route's NIC *is* guaranteed + // to be the NIC on which the packet will be transmitted. + netEP, ok := p.mu.eps[route.NICID()] p.mu.Unlock() if !ok { return &tcpip.ErrNotConnected{} @@ -653,6 +674,10 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip icmpHdr.SetType(header.ICMPv4DstUnreachable) icmpHdr.SetCode(header.ICMPv4NetUnreachable) counter = sent.dstUnreachable + case *icmpReasonHostUnreachable: + icmpHdr.SetType(header.ICMPv4DstUnreachable) + icmpHdr.SetCode(header.ICMPv4HostUnreachable) + counter = sent.dstUnreachable case *icmpReasonFragmentationNeeded: icmpHdr.SetType(header.ICMPv4DstUnreachable) icmpHdr.SetCode(header.ICMPv4FragmentationNeeded) diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go index 23178277a..26fb8a871 100644 --- a/pkg/tcpip/network/ipv4/ipv4.go +++ b/pkg/tcpip/network/ipv4/ipv4.go @@ -104,6 +104,16 @@ type endpoint struct { // HandleLinkResolutionFailure implements stack.LinkResolvableNetworkEndpoint. func (e *endpoint) HandleLinkResolutionFailure(pkt *stack.PacketBuffer) { + // If we are operating as a router, return an ICMP error to the original + // packet's sender. + if pkt.NetworkPacketInfo.IsForwardedPacket { + // TODO(gvisor.dev/issue/6005): Propagate asynchronously generated ICMP + // errors to local endpoints. + e.protocol.returnError(&icmpReasonHostUnreachable{}, pkt) + e.stats.ip.Forwarding.Errors.Increment() + e.stats.ip.Forwarding.HostUnreachable.Increment() + return + } // handleControl expects the entire offending packet to be in the packet // buffer's data field. pkt = stack.NewPacketBuffer(stack.PacketBufferOptions{ diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go index 307e1972d..23fc94303 100644 --- a/pkg/tcpip/network/ipv6/icmp.go +++ b/pkg/tcpip/network/ipv6/icmp.go @@ -1029,6 +1029,26 @@ func (*icmpReasonNetUnreachable) respondsToMulticast() bool { return false } +// icmpReasonHostUnreachable is an error in which the host specified in the +// internet destination field of the datagram is unreachable. +type icmpReasonHostUnreachable struct{} + +func (*icmpReasonHostUnreachable) isICMPReason() {} +func (*icmpReasonHostUnreachable) isForwarding() bool { + // If we hit a Host Unreachable error, then we know we are operating as a + // router. As per RFC 4443 page 8, Destination Unreachable Message, + // + // If the reason for the failure to deliver cannot be mapped to any of + // other codes, the Code field is set to 3. Example of such cases are + // an inability to resolve the IPv6 destination address into a + // corresponding link address, or a link-specific problem of some sort. + return true +} + +func (*icmpReasonHostUnreachable) respondsToMulticast() bool { + return false +} + // icmpReasonFragmentationNeeded is an error where a packet is to big to be sent // out through the outgoing MTU, as per RFC 4443 page 9, Packet Too Big Message. type icmpReasonPacketTooBig struct{} @@ -1143,7 +1163,12 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip defer route.Release() p.mu.Lock() - netEP, ok := p.mu.eps[pkt.NICID] + // We retrieve an endpoint using the newly constructed route's NICID rather + // than the packet's NICID. The packet's NICID corresponds to the NIC on + // which it arrived, which isn't necessarily the same as the NIC on which it + // will be transmitted. On the other hand, the route's NIC *is* guaranteed + // to be the NIC on which the packet will be transmitted. + netEP, ok := p.mu.eps[route.NICID()] p.mu.Unlock() if !ok { return &tcpip.ErrNotConnected{} @@ -1222,6 +1247,10 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip icmpHdr.SetType(header.ICMPv6DstUnreachable) icmpHdr.SetCode(header.ICMPv6NetworkUnreachable) counter = sent.dstUnreachable + case *icmpReasonHostUnreachable: + icmpHdr.SetType(header.ICMPv6DstUnreachable) + icmpHdr.SetCode(header.ICMPv6AddressUnreachable) + counter = sent.dstUnreachable case *icmpReasonPacketTooBig: icmpHdr.SetType(header.ICMPv6PacketTooBig) icmpHdr.SetCode(header.ICMPv6UnusedCode) diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go index 95e11ac51..68f8308f2 100644 --- a/pkg/tcpip/network/ipv6/ipv6.go +++ b/pkg/tcpip/network/ipv6/ipv6.go @@ -282,6 +282,16 @@ func (*endpoint) DuplicateAddressProtocol() tcpip.NetworkProtocolNumber { // HandleLinkResolutionFailure implements stack.LinkResolvableNetworkEndpoint. func (e *endpoint) HandleLinkResolutionFailure(pkt *stack.PacketBuffer) { + // If we are operating as a router, we should return an ICMP error to the + // original packet's sender. + if pkt.NetworkPacketInfo.IsForwardedPacket { + // TODO(gvisor.dev/issue/6005): Propagate asynchronously generated ICMP + // errors to local endpoints. + e.protocol.returnError(&icmpReasonHostUnreachable{}, pkt) + e.stats.ip.Forwarding.Errors.Increment() + e.stats.ip.Forwarding.HostUnreachable.Increment() + return + } // handleControl expects the entire offending packet to be in the packet // buffer's data field. pkt = stack.NewPacketBuffer(stack.PacketBufferOptions{ diff --git a/pkg/tcpip/stack/neighbor_entry.go b/pkg/tcpip/stack/neighbor_entry.go index 6d95e1664..418c71fe5 100644 --- a/pkg/tcpip/stack/neighbor_entry.go +++ b/pkg/tcpip/stack/neighbor_entry.go @@ -307,7 +307,7 @@ func (e *neighborEntry) setStateLocked(next NeighborState) { // a shared lock. e.mu.timer = timer{ done: &done, - timer: e.cache.nic.stack.Clock().AfterFunc(0, func() { + timer: e.cache.nic.stack.Clock().AfterFunc(immediateDuration, func() { var err tcpip.Error = &tcpip.ErrTimeout{} if remaining != 0 { err = e.cache.linkRes.LinkAddressRequest(addr, "" /* localAddr */, linkAddr) @@ -378,7 +378,7 @@ func (e *neighborEntry) handlePacketQueuedLocked(localAddr tcpip.Address) { // a shared lock. e.mu.timer = timer{ done: &done, - timer: e.cache.nic.stack.Clock().AfterFunc(0, func() { + timer: e.cache.nic.stack.Clock().AfterFunc(immediateDuration, func() { var err tcpip.Error = &tcpip.ErrTimeout{} if remaining != 0 { // As per RFC 4861 section 7.2.2: diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go index 797778e08..328470f3e 100644 --- a/pkg/tcpip/tcpip.go +++ b/pkg/tcpip/tcpip.go @@ -1552,6 +1552,10 @@ type IPForwardingStats struct { // were too big for the outgoing MTU. PacketTooBig *StatCounter + // HostUnreachable is the number of IP packets received which could not be + // successfully forwarded due to an unresolvable next hop. + HostUnreachable *StatCounter + // ExtensionHeaderProblem is the number of IP packets which were dropped // because of a problem encountered when processing an IPv6 extension // header. |