diff options
Diffstat (limited to 'pkg/tcpip/stack/nic.go')
| -rw-r--r-- | pkg/tcpip/stack/nic.go | 37 |
1 files changed, 32 insertions, 5 deletions
diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go index d19150a20..447b5c99d 100644 --- a/pkg/tcpip/stack/nic.go +++ b/pkg/tcpip/stack/nic.go @@ -358,16 +358,43 @@ func (n *NIC) writePacket(r RouteInfo, gso *GSO, protocol tcpip.NetworkProtocolN // WritePackets implements NetworkLinkEndpoint. func (n *NIC) WritePackets(r *Route, gso *GSO, pkts PacketBufferList, protocol tcpip.NetworkProtocolNumber) (int, *tcpip.Error) { - // TODO(gvisor.dev/issue/4458): Queue packets whie link address resolution - // is being peformed like WritePacket. - routeInfo := r.Fields() + // As per relevant RFCs, we should queue packets while we wait for link + // resolution to complete. + // + // RFC 1122 section 2.3.2.2 (for IPv4): + // The link layer SHOULD save (rather than discard) at least + // one (the latest) packet of each set of packets destined to + // the same unresolved IP address, and transmit the saved + // packet when the address has been resolved. + // + // RFC 4861 section 7.2.2 (for IPv6): + // While waiting for address resolution to complete, the sender MUST, for + // each neighbor, retain a small queue of packets waiting for address + // resolution to complete. The queue MUST hold at least one packet, and MAY + // contain more. However, the number of queued packets per neighbor SHOULD + // be limited to some small value. When a queue overflows, the new arrival + // SHOULD replace the oldest entry. Once address resolution completes, the + // node transmits any queued packets. + if ch, err := r.Resolve(nil); err != nil { + if err == tcpip.ErrWouldBlock { + r.Acquire() + n.linkResQueue.enqueue(ch, r, protocol, &pkts) + return pkts.Len(), nil + } + return 0, err + } + + return n.writePackets(r.Fields(), gso, protocol, pkts) +} + +func (n *NIC) writePackets(r RouteInfo, gso *GSO, protocol tcpip.NetworkProtocolNumber, pkts PacketBufferList) (int, *tcpip.Error) { for pkt := pkts.Front(); pkt != nil; pkt = pkt.Next() { - pkt.EgressRoute = routeInfo + pkt.EgressRoute = r pkt.GSOOptions = gso pkt.NetworkProtocolNumber = protocol } - writtenPackets, err := n.LinkEndpoint.WritePackets(routeInfo, gso, pkts, protocol) + writtenPackets, err := n.LinkEndpoint.WritePackets(r, gso, pkts, protocol) n.stats.Tx.Packets.IncrementBy(uint64(writtenPackets)) writtenBytes := 0 for i, pb := 0, pkts.Front(); i < writtenPackets && pb != nil; i, pb = i+1, pb.Next() { |