diff options
Diffstat (limited to 'pkg/tcpip/network')
| -rw-r--r-- | pkg/tcpip/network/ipv4/ipv4.go | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go index cfd0c505a..a376cb8ec 100644 --- a/pkg/tcpip/network/ipv4/ipv4.go +++ b/pkg/tcpip/network/ipv4/ipv4.go @@ -199,14 +199,28 @@ func (e *endpoint) NetworkProtocolNumber() tcpip.NetworkProtocolNumber { } func (e *endpoint) addIPHeader(r *stack.Route, pkt *stack.PacketBuffer, params stack.NetworkHeaderParams) { - ip := header.IPv4(pkt.NetworkHeader().Push(header.IPv4MinimumSize)) + hdrLen := header.IPv4MinimumSize + var opts header.IPv4Options + if params.Options != nil { + var ok bool + if opts, ok = params.Options.(header.IPv4Options); !ok { + panic(fmt.Sprintf("want IPv4Options, got %T", params.Options)) + } + hdrLen += opts.AllocationSize() + if hdrLen > header.IPv4MaximumHeaderSize { + // Since we have no way to report an error we must either panic or create + // a packet which is different to what was requested. Choose panic as this + // would be a programming error that should be caught in testing. + panic(fmt.Sprintf("IPv4 Options %d bytes, Max %d", params.Options.AllocationSize(), header.IPv4MaximumOptionsSize)) + } + } + ip := header.IPv4(pkt.NetworkHeader().Push(hdrLen)) length := uint16(pkt.Size()) // RFC 6864 section 4.3 mandates uniqueness of ID values for non-atomic // datagrams. Since the DF bit is never being set here, all datagrams // are non-atomic and need an ID. id := atomic.AddUint32(&e.protocol.ids[hashRoute(r, params.Protocol, e.protocol.hashIV)%buckets], 1) ip.Encode(&header.IPv4Fields{ - IHL: header.IPv4MinimumSize, TotalLength: length, ID: uint16(id), TTL: params.TTL, @@ -214,6 +228,7 @@ func (e *endpoint) addIPHeader(r *stack.Route, pkt *stack.PacketBuffer, params s Protocol: uint8(params.Protocol), SrcAddr: r.LocalAddress, DstAddr: r.RemoteAddress, + Options: opts, }) ip.SetChecksum(^ip.CalculateChecksum()) pkt.NetworkProtocolNumber = ProtocolNumber |