diff options
| author | Ghanan Gowripalan <ghanan@google.com> | 2020-09-29 16:52:14 -0700 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2020-09-29 16:54:23 -0700 |
| commit | 6ae83404afcfdcc02966487973eef354969984f5 (patch) | |
| tree | 1f9ad531163862b21eb6b05805e0a61db47362d5 /pkg/tcpip/network/ipv4 | |
| parent | 4a428b13b20baf055e7e70ecb51a87299f0c6d8e (diff) | |
Don't allow broadcast/multicast source address
As per relevant IP RFCS (see code comments), broadcast (for IPv4) and
multicast addresses are not allowed. Currently checks for these are
done at the transport layer, but since it is explicitly forbidden at
the IP layers, check for them there.
This change also removes the UDP.InvalidSourceAddress stat since there
is no longer a need for it.
Test: ip_test.TestSourceAddressValidation
PiperOrigin-RevId: 334490971
Diffstat (limited to 'pkg/tcpip/network/ipv4')
| -rw-r--r-- | pkg/tcpip/network/ipv4/ipv4.go | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go index cf0a76274..746cf520d 100644 --- a/pkg/tcpip/network/ipv4/ipv4.go +++ b/pkg/tcpip/network/ipv4/ipv4.go @@ -479,6 +479,15 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) { return } + // As per RFC 1122 section 3.2.1.3: + // When a host sends any datagram, the IP source address MUST + // be one of its own IP addresses (but not a broadcast or + // multicast address). + if r.IsOutboundBroadcast() || header.IsV4MulticastAddress(r.RemoteAddress) { + r.Stats().IP.InvalidSourceAddressesReceived.Increment() + return + } + // iptables filtering. All packets that reach here are intended for // this machine and will not be forwarded. ipt := e.protocol.stack.IPTables() @@ -537,6 +546,8 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) { return } } + + r.Stats().IP.PacketsDelivered.Increment() p := h.TransportProtocol() if p == header.ICMPv4ProtocolNumber { // TODO(gvisor.dev/issues/3810): when we sort out ICMP and transport @@ -546,7 +557,6 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) { e.handleICMP(r, pkt) return } - r.Stats().IP.PacketsDelivered.Increment() switch res := e.dispatcher.DeliverTransportPacket(r, p, pkt); res { case stack.TransportPacketHandled: |