diff options
Diffstat (limited to 'pkg/tcpip/network/ipv4/ipv4.go')
-rw-r--r-- | pkg/tcpip/network/ipv4/ipv4.go | 179 |
1 files changed, 114 insertions, 65 deletions
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go index 5cd895ff0..e645cf62c 100644 --- a/pkg/tcpip/network/ipv4/ipv4.go +++ b/pkg/tcpip/network/ipv4/ipv4.go @@ -47,7 +47,7 @@ const ( ) type endpoint struct { - nicid tcpip.NICID + nicID tcpip.NICID id stack.NetworkEndpointID prefixLen int linkEP stack.LinkEndpoint @@ -57,9 +57,9 @@ type endpoint struct { } // NewEndpoint creates a new ipv4 endpoint. -func (p *protocol) NewEndpoint(nicid tcpip.NICID, addrWithPrefix tcpip.AddressWithPrefix, linkAddrCache stack.LinkAddressCache, dispatcher stack.TransportDispatcher, linkEP stack.LinkEndpoint) (stack.NetworkEndpoint, *tcpip.Error) { +func (p *protocol) NewEndpoint(nicID tcpip.NICID, addrWithPrefix tcpip.AddressWithPrefix, linkAddrCache stack.LinkAddressCache, dispatcher stack.TransportDispatcher, linkEP stack.LinkEndpoint) (stack.NetworkEndpoint, *tcpip.Error) { e := &endpoint{ - nicid: nicid, + nicID: nicID, id: stack.NetworkEndpointID{LocalAddress: addrWithPrefix.Address}, prefixLen: addrWithPrefix.PrefixLen, linkEP: linkEP, @@ -89,7 +89,7 @@ func (e *endpoint) Capabilities() stack.LinkEndpointCapabilities { // NICID returns the ID of the NIC this endpoint belongs to. func (e *endpoint) NICID() tcpip.NICID { - return e.nicid + return e.nicID } // ID returns the ipv4 endpoint ID. @@ -117,13 +117,14 @@ func (e *endpoint) GSOMaxSize() uint32 { } // writePacketFragments calls e.linkEP.WritePacket with each packet fragment to -// write. It assumes that the IP header is entirely in hdr but does not assume -// that only the IP header is in hdr. It assumes that the input packet's stated -// length matches the length of the hdr+payload. mtu includes the IP header and -// options. This does not support the DontFragment IP flag. -func (e *endpoint) writePacketFragments(r *stack.Route, gso *stack.GSO, hdr buffer.Prependable, payload buffer.VectorisedView, mtu int) *tcpip.Error { +// write. It assumes that the IP header is entirely in pkt.Header but does not +// assume that only the IP header is in pkt.Header. It assumes that the input +// packet's stated length matches the length of the header+payload. mtu +// includes the IP header and options. This does not support the DontFragment +// IP flag. +func (e *endpoint) writePacketFragments(r *stack.Route, gso *stack.GSO, mtu int, pkt tcpip.PacketBuffer) *tcpip.Error { // This packet is too big, it needs to be fragmented. - ip := header.IPv4(hdr.View()) + ip := header.IPv4(pkt.Header.View()) flags := ip.Flags() // Update mtu to take into account the header, which will exist in all @@ -137,71 +138,85 @@ func (e *endpoint) writePacketFragments(r *stack.Route, gso *stack.GSO, hdr buff outerMTU := innerMTU + int(ip.HeaderLength()) offset := ip.FragmentOffset() - originalAvailableLength := hdr.AvailableLength() + originalAvailableLength := pkt.Header.AvailableLength() for i := 0; i < n; i++ { // Where possible, the first fragment that is sent has the same - // hdr.UsedLength() as the input packet. The link-layer endpoint may depends - // on this for looking at, eg, L4 headers. + // pkt.Header.UsedLength() as the input packet. The link-layer + // endpoint may depend on this for looking at, eg, L4 headers. h := ip if i > 0 { - hdr = buffer.NewPrependable(int(ip.HeaderLength()) + originalAvailableLength) - h = header.IPv4(hdr.Prepend(int(ip.HeaderLength()))) + pkt.Header = buffer.NewPrependable(int(ip.HeaderLength()) + originalAvailableLength) + h = header.IPv4(pkt.Header.Prepend(int(ip.HeaderLength()))) copy(h, ip[:ip.HeaderLength()]) } if i != n-1 { h.SetTotalLength(uint16(outerMTU)) h.SetFlagsFragmentOffset(flags|header.IPv4FlagMoreFragments, offset) } else { - h.SetTotalLength(uint16(h.HeaderLength()) + uint16(payload.Size())) + h.SetTotalLength(uint16(h.HeaderLength()) + uint16(pkt.Data.Size())) h.SetFlagsFragmentOffset(flags, offset) } h.SetChecksum(0) h.SetChecksum(^h.CalculateChecksum()) offset += uint16(innerMTU) if i > 0 { - newPayload := payload.Clone([]buffer.View{}) + newPayload := pkt.Data.Clone(nil) newPayload.CapLength(innerMTU) - if err := e.linkEP.WritePacket(r, gso, hdr, newPayload, ProtocolNumber); err != nil { + if err := e.linkEP.WritePacket(r, gso, ProtocolNumber, tcpip.PacketBuffer{ + Header: pkt.Header, + Data: newPayload, + NetworkHeader: buffer.View(h), + }); err != nil { return err } r.Stats().IP.PacketsSent.Increment() - payload.TrimFront(newPayload.Size()) + pkt.Data.TrimFront(newPayload.Size()) continue } - // Special handling for the first fragment because it comes from the hdr. - if outerMTU >= hdr.UsedLength() { - // This fragment can fit all of hdr and possibly some of payload, too. - newPayload := payload.Clone([]buffer.View{}) - newPayloadLength := outerMTU - hdr.UsedLength() + // Special handling for the first fragment because it comes + // from the header. + if outerMTU >= pkt.Header.UsedLength() { + // This fragment can fit all of pkt.Header and possibly + // some of pkt.Data, too. + newPayload := pkt.Data.Clone(nil) + newPayloadLength := outerMTU - pkt.Header.UsedLength() newPayload.CapLength(newPayloadLength) - if err := e.linkEP.WritePacket(r, gso, hdr, newPayload, ProtocolNumber); err != nil { + if err := e.linkEP.WritePacket(r, gso, ProtocolNumber, tcpip.PacketBuffer{ + Header: pkt.Header, + Data: newPayload, + NetworkHeader: buffer.View(h), + }); err != nil { return err } r.Stats().IP.PacketsSent.Increment() - payload.TrimFront(newPayloadLength) + pkt.Data.TrimFront(newPayloadLength) } else { - // The fragment is too small to fit all of hdr. - startOfHdr := hdr - startOfHdr.TrimBack(hdr.UsedLength() - outerMTU) + // The fragment is too small to fit all of pkt.Header. + startOfHdr := pkt.Header + startOfHdr.TrimBack(pkt.Header.UsedLength() - outerMTU) emptyVV := buffer.NewVectorisedView(0, []buffer.View{}) - if err := e.linkEP.WritePacket(r, gso, startOfHdr, emptyVV, ProtocolNumber); err != nil { + if err := e.linkEP.WritePacket(r, gso, ProtocolNumber, tcpip.PacketBuffer{ + Header: startOfHdr, + Data: emptyVV, + NetworkHeader: buffer.View(h), + }); err != nil { return err } r.Stats().IP.PacketsSent.Increment() - // Add the unused bytes of hdr into the payload that remains to be sent. - restOfHdr := hdr.View()[outerMTU:] + // Add the unused bytes of pkt.Header into the pkt.Data + // that remains to be sent. + restOfHdr := pkt.Header.View()[outerMTU:] tmp := buffer.NewVectorisedView(len(restOfHdr), []buffer.View{buffer.NewViewFromBytes(restOfHdr)}) - tmp.Append(payload) - payload = tmp + tmp.Append(pkt.Data) + pkt.Data = tmp } } return nil } -// WritePacket writes a packet to the given destination address and protocol. -func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, hdr buffer.Prependable, payload buffer.VectorisedView, params stack.NetworkHeaderParams, loop stack.PacketLooping) *tcpip.Error { +func (e *endpoint) addIPHeader(r *stack.Route, hdr *buffer.Prependable, payloadSize int, params stack.NetworkHeaderParams) header.IPv4 { ip := header.IPv4(hdr.Prepend(header.IPv4MinimumSize)) - length := uint16(hdr.UsedLength() + payload.Size()) + length := uint16(hdr.UsedLength() + payloadSize) id := uint32(0) if length > header.IPv4MaximumHeaderSize+8 { // Packets of 68 bytes or less are required by RFC 791 to not be @@ -219,41 +234,71 @@ func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, hdr buffer.Prepen DstAddr: r.RemoteAddress, }) ip.SetChecksum(^ip.CalculateChecksum()) + return ip +} + +// WritePacket writes a packet to the given destination address and protocol. +func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, params stack.NetworkHeaderParams, loop stack.PacketLooping, pkt tcpip.PacketBuffer) *tcpip.Error { + ip := e.addIPHeader(r, &pkt.Header, pkt.Data.Size(), params) + pkt.NetworkHeader = buffer.View(ip) if loop&stack.PacketLoop != 0 { - views := make([]buffer.View, 1, 1+len(payload.Views())) - views[0] = hdr.View() - views = append(views, payload.Views()...) - vv := buffer.NewVectorisedView(len(views[0])+payload.Size(), views) + // The inbound path expects the network header to still be in + // the PacketBuffer's Data field. + views := make([]buffer.View, 1, 1+len(pkt.Data.Views())) + views[0] = pkt.Header.View() + views = append(views, pkt.Data.Views()...) loopedR := r.MakeLoopedRoute() - e.HandlePacket(&loopedR, vv) + + e.HandlePacket(&loopedR, tcpip.PacketBuffer{ + Data: buffer.NewVectorisedView(len(views[0])+pkt.Data.Size(), views), + }) + loopedR.Release() } if loop&stack.PacketOut == 0 { return nil } - if hdr.UsedLength()+payload.Size() > int(e.linkEP.MTU()) && (gso == nil || gso.Type == stack.GSONone) { - return e.writePacketFragments(r, gso, hdr, payload, int(e.linkEP.MTU())) + if pkt.Header.UsedLength()+pkt.Data.Size() > int(e.linkEP.MTU()) && (gso == nil || gso.Type == stack.GSONone) { + return e.writePacketFragments(r, gso, int(e.linkEP.MTU()), pkt) } - if err := e.linkEP.WritePacket(r, gso, hdr, payload, ProtocolNumber); err != nil { + if err := e.linkEP.WritePacket(r, gso, ProtocolNumber, pkt); err != nil { return err } r.Stats().IP.PacketsSent.Increment() return nil } +// WritePackets implements stack.NetworkEndpoint.WritePackets. +func (e *endpoint) WritePackets(r *stack.Route, gso *stack.GSO, pkts []tcpip.PacketBuffer, params stack.NetworkHeaderParams, loop stack.PacketLooping) (int, *tcpip.Error) { + if loop&stack.PacketLoop != 0 { + panic("multiple packets in local loop") + } + if loop&stack.PacketOut == 0 { + return len(pkts), nil + } + + for i := range pkts { + ip := e.addIPHeader(r, &pkts[i].Header, pkts[i].DataSize, params) + pkts[i].NetworkHeader = buffer.View(ip) + } + n, err := e.linkEP.WritePackets(r, gso, pkts, ProtocolNumber) + r.Stats().IP.PacketsSent.IncrementBy(uint64(n)) + return n, err +} + // WriteHeaderIncludedPacket writes a packet already containing a network // header through the given route. -func (e *endpoint) WriteHeaderIncludedPacket(r *stack.Route, payload buffer.VectorisedView, loop stack.PacketLooping) *tcpip.Error { +func (e *endpoint) WriteHeaderIncludedPacket(r *stack.Route, loop stack.PacketLooping, pkt tcpip.PacketBuffer) *tcpip.Error { // The packet already has an IP header, but there are a few required // checks. - ip := header.IPv4(payload.First()) - if !ip.IsValid(payload.Size()) { + ip := header.IPv4(pkt.Data.First()) + if !ip.IsValid(pkt.Data.Size()) { return tcpip.ErrInvalidOptionValue } // Always set the total length. - ip.SetTotalLength(uint16(payload.Size())) + ip.SetTotalLength(uint16(pkt.Data.Size())) // Set the source address when zero. if ip.SourceAddress() == tcpip.Address(([]byte{0, 0, 0, 0})) { @@ -267,7 +312,7 @@ func (e *endpoint) WriteHeaderIncludedPacket(r *stack.Route, payload buffer.Vect // Set the packet ID when zero. if ip.ID() == 0 { id := uint32(0) - if payload.Size() > header.IPv4MaximumHeaderSize+8 { + if pkt.Data.Size() > header.IPv4MaximumHeaderSize+8 { // Packets of 68 bytes or less are required by RFC 791 to not be // fragmented, so we only assign ids to larger packets. id = atomic.AddUint32(&e.protocol.ids[hashRoute(r, 0 /* protocol */, e.protocol.hashIV)%buckets], 1) @@ -280,35 +325,39 @@ func (e *endpoint) WriteHeaderIncludedPacket(r *stack.Route, payload buffer.Vect ip.SetChecksum(^ip.CalculateChecksum()) if loop&stack.PacketLoop != 0 { - e.HandlePacket(r, payload) + e.HandlePacket(r, pkt.Clone()) } if loop&stack.PacketOut == 0 { return nil } - hdr := buffer.NewPrependableFromView(payload.ToView()) r.Stats().IP.PacketsSent.Increment() - return e.linkEP.WritePacket(r, nil /* gso */, hdr, buffer.VectorisedView{}, ProtocolNumber) + + ip = ip[:ip.HeaderLength()] + pkt.Header = buffer.NewPrependableFromView(buffer.View(ip)) + pkt.Data.TrimFront(int(ip.HeaderLength())) + return e.linkEP.WritePacket(r, nil /* gso */, ProtocolNumber, pkt) } // HandlePacket is called by the link layer when new ipv4 packets arrive for // this endpoint. -func (e *endpoint) HandlePacket(r *stack.Route, vv buffer.VectorisedView) { - headerView := vv.First() +func (e *endpoint) HandlePacket(r *stack.Route, pkt tcpip.PacketBuffer) { + headerView := pkt.Data.First() h := header.IPv4(headerView) - if !h.IsValid(vv.Size()) { + if !h.IsValid(pkt.Data.Size()) { r.Stats().IP.MalformedPacketsReceived.Increment() return } + pkt.NetworkHeader = headerView[:h.HeaderLength()] hlen := int(h.HeaderLength()) tlen := int(h.TotalLength()) - vv.TrimFront(hlen) - vv.CapLength(tlen - hlen) + pkt.Data.TrimFront(hlen) + pkt.Data.CapLength(tlen - hlen) more := (h.Flags() & header.IPv4FlagMoreFragments) != 0 if more || h.FragmentOffset() != 0 { - if vv.Size() == 0 { + if pkt.Data.Size() == 0 { // Drop the packet as it's marked as a fragment but has // no payload. r.Stats().IP.MalformedPacketsReceived.Increment() @@ -316,10 +365,10 @@ func (e *endpoint) HandlePacket(r *stack.Route, vv buffer.VectorisedView) { return } // The packet is a fragment, let's try to reassemble it. - last := h.FragmentOffset() + uint16(vv.Size()) - 1 + last := h.FragmentOffset() + uint16(pkt.Data.Size()) - 1 // Drop the packet if the fragmentOffset is incorrect. i.e the - // combination of fragmentOffset and vv.size() causes a wrap - // around resulting in last being less than the offset. + // combination of fragmentOffset and pkt.Data.size() causes a + // wrap around resulting in last being less than the offset. if last < h.FragmentOffset() { r.Stats().IP.MalformedPacketsReceived.Increment() r.Stats().IP.MalformedFragmentsReceived.Increment() @@ -327,7 +376,7 @@ func (e *endpoint) HandlePacket(r *stack.Route, vv buffer.VectorisedView) { } var ready bool var err error - vv, ready, err = e.fragmentation.Process(hash.IPv4FragmentHash(h), h.FragmentOffset(), last, more, vv) + pkt.Data, ready, err = e.fragmentation.Process(hash.IPv4FragmentHash(h), h.FragmentOffset(), last, more, pkt.Data) if err != nil { r.Stats().IP.MalformedPacketsReceived.Increment() r.Stats().IP.MalformedFragmentsReceived.Increment() @@ -340,11 +389,11 @@ func (e *endpoint) HandlePacket(r *stack.Route, vv buffer.VectorisedView) { p := h.TransportProtocol() if p == header.ICMPv4ProtocolNumber { headerView.CapLength(hlen) - e.handleICMP(r, headerView, vv) + e.handleICMP(r, pkt) return } r.Stats().IP.PacketsDelivered.Increment() - e.dispatcher.DeliverTransportPacket(r, p, headerView, vv) + e.dispatcher.DeliverTransportPacket(r, p, pkt) } // Close cleans up resources associated with the endpoint. |