diff options
| -rw-r--r-- | pkg/tcpip/network/ipv4/ipv4.go | 81 | ||||
| -rw-r--r-- | pkg/tcpip/network/ipv6/ipv6.go | 25 |
2 files changed, 65 insertions, 41 deletions
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go index 7e2e53523..743aa0575 100644 --- a/pkg/tcpip/network/ipv4/ipv4.go +++ b/pkg/tcpip/network/ipv4/ipv4.go @@ -190,29 +190,6 @@ func (e *endpoint) NetworkProtocolNumber() tcpip.NetworkProtocolNumber { return e.protocol.Number() } -// writePacketFragments fragments pkt and writes the results on the link -// endpoint. The IP header must already present in the original packet. The mtu -// is the maximum size of the packets. -func (e *endpoint) writePacketFragments(r *stack.Route, gso *stack.GSO, mtu uint32, pkt *stack.PacketBuffer) *tcpip.Error { - networkHeader := header.IPv4(pkt.NetworkHeader().View()) - fragMTU := int(calculateFragmentInnerMTU(mtu, pkt)) - pf := fragmentation.MakePacketFragmenter(pkt, fragMTU, pkt.AvailableHeaderBytes()+len(networkHeader)) - - for { - fragPkt, more := buildNextFragment(&pf, networkHeader) - if err := e.nic.WritePacket(r, gso, ProtocolNumber, fragPkt); err != nil { - r.Stats().IP.OutgoingPacketErrors.IncrementBy(uint64(pf.RemainingFragmentCount() + 1)) - return err - } - r.Stats().IP.PacketsSent.Increment() - if !more { - break - } - } - - return nil -} - func (e *endpoint) addIPHeader(r *stack.Route, pkt *stack.PacketBuffer, params stack.NetworkHeaderParams) { ip := header.IPv4(pkt.NetworkHeader().Push(header.IPv4MinimumSize)) length := uint16(pkt.Size()) @@ -234,6 +211,32 @@ func (e *endpoint) addIPHeader(r *stack.Route, pkt *stack.PacketBuffer, params s pkt.NetworkProtocolNumber = ProtocolNumber } +func (e *endpoint) packetMustBeFragmented(pkt *stack.PacketBuffer, gso *stack.GSO) bool { + return (gso == nil || gso.Type == stack.GSONone) && pkt.Size() > int(e.nic.MTU()) +} + +// handleFragments fragments pkt and calls the handler function on each +// fragment. It returns the number of fragments handled and the number of +// fragments left to be processed. The IP header must already be present in the +// original packet. The mtu is the maximum size of the packets. +func (e *endpoint) handleFragments(r *stack.Route, gso *stack.GSO, mtu uint32, pkt *stack.PacketBuffer, handler func(*stack.PacketBuffer) *tcpip.Error) (int, int, *tcpip.Error) { + fragMTU := int(calculateFragmentInnerMTU(mtu, pkt)) + networkHeader := header.IPv4(pkt.NetworkHeader().View()) + pf := fragmentation.MakePacketFragmenter(pkt, fragMTU, pkt.AvailableHeaderBytes()+len(networkHeader)) + + var n int + for { + fragPkt, more := buildNextFragment(&pf, networkHeader) + if err := handler(fragPkt); err != nil { + return n, pf.RemainingFragmentCount() + 1, err + } + n++ + if !more { + return n, pf.RemainingFragmentCount(), nil + } + } +} + // WritePacket writes a packet to the given destination address and protocol. func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, params stack.NetworkHeaderParams, pkt *stack.PacketBuffer) *tcpip.Error { e.addIPHeader(r, pkt, params) @@ -276,8 +279,18 @@ func (e *endpoint) writePacket(r *stack.Route, gso *stack.GSO, pkt *stack.Packet if r.Loop&stack.PacketOut == 0 { return nil } - if pkt.Size() > int(e.nic.MTU()) && (gso == nil || gso.Type == stack.GSONone) { - return e.writePacketFragments(r, gso, e.nic.MTU(), pkt) + + if e.packetMustBeFragmented(pkt, gso) { + sent, remain, err := e.handleFragments(r, gso, e.nic.MTU(), pkt, func(fragPkt *stack.PacketBuffer) *tcpip.Error { + // TODO(gvisor.dev/issue/3884): Evaluate whether we want to send each + // fragment one by one using WritePacket() (current strategy) or if we + // want to create a PacketBufferList from the fragments and feed it to + // WritePackets(). It'll be faster but cost more memory. + return e.nic.WritePacket(r, gso, ProtocolNumber, fragPkt) + }) + r.Stats().IP.PacketsSent.IncrementBy(uint64(sent)) + r.Stats().IP.OutgoingPacketErrors.IncrementBy(uint64(remain)) + return err } if err := e.nic.WritePacket(r, gso, ProtocolNumber, pkt); err != nil { r.Stats().IP.OutgoingPacketErrors.Increment() @@ -296,9 +309,23 @@ func (e *endpoint) WritePackets(r *stack.Route, gso *stack.GSO, pkts stack.Packe return pkts.Len(), nil } - for pkt := pkts.Front(); pkt != nil; { + for pkt := pkts.Front(); pkt != nil; pkt = pkt.Next() { e.addIPHeader(r, pkt, params) - pkt = pkt.Next() + if e.packetMustBeFragmented(pkt, gso) { + // Keep track of the packet that is about to be fragmented so it can be + // removed once the fragmentation is done. + originalPkt := pkt + if _, _, err := e.handleFragments(r, gso, e.nic.MTU(), pkt, func(fragPkt *stack.PacketBuffer) *tcpip.Error { + // Modify the packet list in place with the new fragments. + pkts.InsertAfter(pkt, fragPkt) + pkt = fragPkt + return nil + }); err != nil { + panic(fmt.Sprintf("e.handleFragments(_, _, %d, _, _) = %s", e.nic.MTU(), err)) + } + // Remove the packet that was just fragmented and process the rest. + pkts.Remove(originalPkt) + } } nicName := e.protocol.stack.FindNICNameFromID(e.nic.ID()) diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go index 632914dd6..9670696c7 100644 --- a/pkg/tcpip/network/ipv6/ipv6.go +++ b/pkg/tcpip/network/ipv6/ipv6.go @@ -387,7 +387,7 @@ func (e *endpoint) addIPHeader(r *stack.Route, pkt *stack.PacketBuffer, params s } func (e *endpoint) packetMustBeFragmented(pkt *stack.PacketBuffer, gso *stack.GSO) bool { - return pkt.Size() > int(e.nic.MTU()) && (gso == nil || gso.Type == stack.GSONone) + return (gso == nil || gso.Type == stack.GSONone) && pkt.Size() > int(e.nic.MTU()) } // handleFragments fragments pkt and calls the handler function on each @@ -416,11 +416,9 @@ func (e *endpoint) handleFragments(r *stack.Route, gso *stack.GSO, mtu uint32, p } n++ if !more { - break + return n, pf.RemainingFragmentCount(), nil } } - - return n, 0, nil } // WritePacket writes a packet to the given destination address and protocol. @@ -504,21 +502,20 @@ func (e *endpoint) WritePackets(r *stack.Route, gso *stack.GSO, pkts stack.Packe for pb := pkts.Front(); pb != nil; pb = pb.Next() { e.addIPHeader(r, pb, params) if e.packetMustBeFragmented(pb, gso) { - current := pb - _, _, err := e.handleFragments(r, gso, e.nic.MTU(), pb, params.Protocol, func(fragPkt *stack.PacketBuffer) *tcpip.Error { + // Keep track of the packet that is about to be fragmented so it can be + // removed once the fragmentation is done. + originalPkt := pb + if _, _, err := e.handleFragments(r, gso, e.nic.MTU(), pb, params.Protocol, func(fragPkt *stack.PacketBuffer) *tcpip.Error { // Modify the packet list in place with the new fragments. - pkts.InsertAfter(current, fragPkt) - current = current.Next() + pkts.InsertAfter(pb, fragPkt) + pb = fragPkt return nil - }) - if err != nil { + }); err != nil { r.Stats().IP.OutgoingPacketErrors.IncrementBy(uint64(pkts.Len())) return 0, err } - // The fragmented packet can be released. The rest of the packets can be - // processed. - pkts.Remove(pb) - pb = current + // Remove the packet that was just fragmented and process the rest. + pkts.Remove(originalPkt) } } |