diff options
Diffstat (limited to 'pkg/tcpip/stack')
| -rw-r--r-- | pkg/tcpip/stack/nic.go | 48 | ||||
| -rw-r--r-- | pkg/tcpip/stack/registration.go | 30 |
2 files changed, 35 insertions, 43 deletions
diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go index 06d70dd1c..2875a5b60 100644 --- a/pkg/tcpip/stack/nic.go +++ b/pkg/tcpip/stack/nic.go @@ -1398,11 +1398,13 @@ func (n *NIC) forwardPacket(r *Route, protocol tcpip.NetworkProtocolNumber, pkt // DeliverTransportPacket delivers the packets to the appropriate transport // protocol endpoint. -func (n *NIC) DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, pkt *PacketBuffer) { +func (n *NIC) DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, pkt *PacketBuffer) TransportPacketDisposition { state, ok := n.stack.transportProtocols[protocol] if !ok { + // TODO(gvisor.dev/issue/4365): Let the caller know that the transport + // protocol is unrecognized. n.stack.stats.UnknownProtocolRcvdPackets.Increment() - return + return TransportPacketHandled } transProto := state.proto @@ -1423,59 +1425,47 @@ func (n *NIC) DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolN // we parse it using the minimum size. if _, ok := pkt.TransportHeader().Consume(transProto.MinimumPacketSize()); !ok { n.stack.stats.MalformedRcvdPackets.Increment() - return + // We consider a malformed transport packet handled because there is + // nothing the caller can do. + return TransportPacketHandled } - } else { - // This is either a bad packet or was re-assembled from fragments. - transProto.Parse(pkt) + } else if !transProto.Parse(pkt) { + n.stack.stats.MalformedRcvdPackets.Increment() + return TransportPacketHandled } } - if pkt.TransportHeader().View().Size() < transProto.MinimumPacketSize() { - n.stack.stats.MalformedRcvdPackets.Increment() - return - } - srcPort, dstPort, err := transProto.ParsePorts(pkt.TransportHeader().View()) if err != nil { n.stack.stats.MalformedRcvdPackets.Increment() - return + return TransportPacketHandled } id := TransportEndpointID{dstPort, r.LocalAddress, srcPort, r.RemoteAddress} if n.stack.demux.deliverPacket(r, protocol, pkt, id) { - return + return TransportPacketHandled } // Try to deliver to per-stack default handler. if state.defaultHandler != nil { if state.defaultHandler(r, id, pkt) { - return + return TransportPacketHandled } } // We could not find an appropriate destination for this packet so // give the protocol specific error handler a chance to handle it. // If it doesn't handle it then we should do so. - switch transProto.HandleUnknownDestinationPacket(r, id, pkt) { + switch res := transProto.HandleUnknownDestinationPacket(r, id, pkt); res { case UnknownDestinationPacketMalformed: n.stack.stats.MalformedRcvdPackets.Increment() + return TransportPacketHandled case UnknownDestinationPacketUnhandled: - // As per RFC: 1122 Section 3.2.2.1 A host SHOULD generate Destination - // Unreachable messages with code: - // 3 (Port Unreachable), when the designated transport protocol - // (e.g., UDP) is unable to demultiplex the datagram but has no - // protocol mechanism to inform the sender. - np, ok := n.stack.networkProtocols[r.NetProto] - if !ok { - // For this to happen stack.makeRoute() must have been called with the - // incorrect protocol number. Since we have successfully completed - // network layer processing this should be impossible. - panic(fmt.Sprintf("expected stack to have a NetworkProtocol for proto = %d", r.NetProto)) - } - - _ = np.ReturnError(r, &tcpip.ICMPReasonPortUnreachable{}, pkt) + return TransportPacketDestinationPortUnreachable case UnknownDestinationPacketHandled: + return TransportPacketHandled + default: + panic(fmt.Sprintf("unrecognized result from HandleUnknownDestinationPacket = %d", res)) } } diff --git a/pkg/tcpip/stack/registration.go b/pkg/tcpip/stack/registration.go index 77640cd8a..780a5ebde 100644 --- a/pkg/tcpip/stack/registration.go +++ b/pkg/tcpip/stack/registration.go @@ -197,6 +197,21 @@ type TransportProtocol interface { Parse(pkt *PacketBuffer) (ok bool) } +// TransportPacketDisposition is the result from attempting to deliver a packet +// to the transport layer. +type TransportPacketDisposition int + +const ( + // TransportPacketHandled indicates that a transport packet was handled by the + // transport layer and callers need not take any further action. + TransportPacketHandled TransportPacketDisposition = iota + + // TransportPacketDestinationPortUnreachable indicates that there weren't any + // listeners interested in the packet and the transport protocol has no means + // to notify the sender. + TransportPacketDestinationPortUnreachable +) + // TransportDispatcher contains the methods used by the network stack to deliver // packets to the appropriate transport endpoint after it has been handled by // the network layer. @@ -207,7 +222,7 @@ type TransportDispatcher interface { // pkt.NetworkHeader must be set before calling DeliverTransportPacket. // // DeliverTransportPacket takes ownership of pkt. - DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, pkt *PacketBuffer) + DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, pkt *PacketBuffer) TransportPacketDisposition // DeliverTransportControlPacket delivers control packets to the // appropriate transport protocol endpoint. @@ -342,19 +357,6 @@ type NetworkProtocol interface { // does not encapsulate anything). // - Whether pkt.Data was large enough to parse and set pkt.NetworkHeader. Parse(pkt *PacketBuffer) (proto tcpip.TransportProtocolNumber, hasTransportHdr bool, ok bool) - - // ReturnError attempts to send a suitable error message to the sender - // of a received packet. - // - pkt holds the problematic packet. - // - reason indicates what the reason for wanting a message is. - // - route is the routing information for the received packet - // ReturnError returns an error if the send failed and nil on success. - // Note that deciding to deliberately send no message is a success. - // - // TODO(gvisor.dev/issues/3871): This method should be removed or simplified - // after all (or all but one) of the ICMP error dispatch occurs through the - // protocol specific modules. May become SendPortNotFound(r, pkt). - ReturnError(r *Route, reason tcpip.ICMPReason, pkt *PacketBuffer) *tcpip.Error } // NetworkDispatcher contains the methods used by the network stack to deliver |