diff options
Diffstat (limited to 'pkg/tcpip/network/ipv4')
| -rw-r--r-- | pkg/tcpip/network/ipv4/icmp.go | 24 | ||||
| -rw-r--r-- | pkg/tcpip/network/ipv4/ipv4.go | 49 |
2 files changed, 56 insertions, 17 deletions
diff --git a/pkg/tcpip/network/ipv4/icmp.go b/pkg/tcpip/network/ipv4/icmp.go index bc7f1c42a..fbef6947d 100644 --- a/pkg/tcpip/network/ipv4/icmp.go +++ b/pkg/tcpip/network/ipv4/icmp.go @@ -68,10 +68,6 @@ func (e *endpoint) handleICMP(r *stack.Route, netHeader buffer.View, vv buffer.V switch h.Type() { case header.ICMPv4Echo: received.Echo.Increment() - if len(v) < header.ICMPv4EchoMinimumSize { - received.Invalid.Increment() - return - } // Only send a reply if the checksum is valid. wantChecksum := h.Checksum() @@ -93,9 +89,9 @@ func (e *endpoint) handleICMP(r *stack.Route, netHeader buffer.View, vv buffer.V e.dispatcher.DeliverTransportPacket(r, header.ICMPv4ProtocolNumber, netHeader, vv) vv := vv.Clone(nil) - vv.TrimFront(header.ICMPv4EchoMinimumSize) - hdr := buffer.NewPrependable(int(r.MaxHeaderLength()) + header.ICMPv4EchoMinimumSize) - pkt := header.ICMPv4(hdr.Prepend(header.ICMPv4EchoMinimumSize)) + vv.TrimFront(header.ICMPv4MinimumSize) + hdr := buffer.NewPrependable(int(r.MaxHeaderLength()) + header.ICMPv4MinimumSize) + pkt := header.ICMPv4(hdr.Prepend(header.ICMPv4MinimumSize)) copy(pkt, h) pkt.SetType(header.ICMPv4EchoReply) pkt.SetChecksum(^header.Checksum(pkt, header.ChecksumVV(vv, 0))) @@ -108,25 +104,19 @@ func (e *endpoint) handleICMP(r *stack.Route, netHeader buffer.View, vv buffer.V case header.ICMPv4EchoReply: received.EchoReply.Increment() - if len(v) < header.ICMPv4EchoMinimumSize { - received.Invalid.Increment() - return - } + e.dispatcher.DeliverTransportPacket(r, header.ICMPv4ProtocolNumber, netHeader, vv) case header.ICMPv4DstUnreachable: received.DstUnreachable.Increment() - if len(v) < header.ICMPv4DstUnreachableMinimumSize { - received.Invalid.Increment() - return - } - vv.TrimFront(header.ICMPv4DstUnreachableMinimumSize) + + vv.TrimFront(header.ICMPv4MinimumSize) switch h.Code() { case header.ICMPv4PortUnreachable: e.handleControl(stack.ControlPortUnreachable, 0, vv) case header.ICMPv4FragmentationNeeded: - mtu := uint32(binary.BigEndian.Uint16(v[header.ICMPv4DstUnreachableMinimumSize-2:])) + mtu := uint32(binary.BigEndian.Uint16(v[header.ICMPv4PayloadOffset+2:])) e.handleControl(stack.ControlPacketTooBig, calculateMTU(mtu), vv) } diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go index 1e3a7425a..e44a73d96 100644 --- a/pkg/tcpip/network/ipv4/ipv4.go +++ b/pkg/tcpip/network/ipv4/ipv4.go @@ -232,6 +232,55 @@ func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, hdr buffer.Prepen return nil } +// 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 { + // The packet already has an IP header, but there are a few required + // checks. + ip := header.IPv4(payload.First()) + if !ip.IsValid(payload.Size()) { + return tcpip.ErrInvalidOptionValue + } + + // Always set the total length. + ip.SetTotalLength(uint16(payload.Size())) + + // Set the source address when zero. + if ip.SourceAddress() == tcpip.Address(([]byte{0, 0, 0, 0})) { + ip.SetSourceAddress(r.LocalAddress) + } + + // Set the destination. If the packet already included a destination, + // it will be part of the route. + ip.SetDestinationAddress(r.RemoteAddress) + + // Set the packet ID when zero. + if ip.ID() == 0 { + id := uint32(0) + if payload.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(&ids[hashRoute(r, 0 /* protocol */)%buckets], 1) + } + ip.SetID(uint16(id)) + } + + // Always set the checksum. + ip.SetChecksum(0) + ip.SetChecksum(^ip.CalculateChecksum()) + + if loop&stack.PacketLoop != 0 { + e.HandlePacket(r, payload) + } + 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) +} + // 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) { |