diff options
Diffstat (limited to 'pkg/tcpip/network/ipv4')
| -rw-r--r-- | pkg/tcpip/network/ipv4/ipv4.go | 40 |
1 files changed, 19 insertions, 21 deletions
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go index c5ac7b8b5..7e2e53523 100644 --- a/pkg/tcpip/network/ipv4/ipv4.go +++ b/pkg/tcpip/network/ipv4/ipv4.go @@ -237,7 +237,10 @@ func (e *endpoint) addIPHeader(r *stack.Route, pkt *stack.PacketBuffer, params s // 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) + return e.writePacket(r, gso, pkt) +} +func (e *endpoint) writePacket(r *stack.Route, gso *stack.GSO, pkt *stack.PacketBuffer) *tcpip.Error { // iptables filtering. All packets that reach here are locally // generated. nicName := e.protocol.stack.FindNICNameFromID(e.nic.ID()) @@ -347,30 +350,27 @@ func (e *endpoint) WritePackets(r *stack.Route, gso *stack.GSO, pkts stack.Packe return n + len(dropped), nil } -// WriteHeaderIncludedPacket writes a packet already containing a network -// header through the given route. +// WriteHeaderIncludedPacket implements stack.NetworkEndpoint. func (e *endpoint) WriteHeaderIncludedPacket(r *stack.Route, pkt *stack.PacketBuffer) *tcpip.Error { // The packet already has an IP header, but there are a few required // checks. h, ok := pkt.Data.PullUp(header.IPv4MinimumSize) if !ok { - return tcpip.ErrInvalidOptionValue + return tcpip.ErrMalformedHeader } ip := header.IPv4(h) - if !ip.IsValid(pkt.Data.Size()) { - return tcpip.ErrInvalidOptionValue - } // Always set the total length. - ip.SetTotalLength(uint16(pkt.Data.Size())) + pktSize := pkt.Data.Size() + ip.SetTotalLength(uint16(pktSize)) // Set the source address when zero. - if ip.SourceAddress() == tcpip.Address(([]byte{0, 0, 0, 0})) { + if ip.SourceAddress() == header.IPv4Any { ip.SetSourceAddress(r.LocalAddress) } - // Set the destination. If the packet already included a destination, - // it will be part of the route. + // Set the destination. If the packet already included a destination, it will + // be part of the route anyways. ip.SetDestinationAddress(r.RemoteAddress) // Set the packet ID when zero. @@ -387,19 +387,17 @@ func (e *endpoint) WriteHeaderIncludedPacket(r *stack.Route, pkt *stack.PacketBu ip.SetChecksum(0) ip.SetChecksum(^ip.CalculateChecksum()) - if r.Loop&stack.PacketLoop != 0 { - e.HandlePacket(r, pkt.Clone()) - } - if r.Loop&stack.PacketOut == 0 { - return nil + // Populate the packet buffer's network header and don't allow an invalid + // packet to be sent. + // + // Note that parsing only makes sure that the packet is well formed as per the + // wire format. We also want to check if the header's fields are valid before + // sending the packet. + if !parse.IPv4(pkt) || !header.IPv4(pkt.NetworkHeader().View()).IsValid(pktSize) { + return tcpip.ErrMalformedHeader } - if err := e.nic.WritePacket(r, nil /* gso */, ProtocolNumber, pkt); err != nil { - r.Stats().IP.OutgoingPacketErrors.Increment() - return err - } - r.Stats().IP.PacketsSent.Increment() - return nil + return e.writePacket(r, nil /* gso */, pkt) } // HandlePacket is called by the link layer when new ipv4 packets arrive for |