net: ipv4: route: Fix sending IGMP messages with link address
In setups with a global scope address on an interface, and a lesser
scope address on an interface sending IGMP reports, the reports can be
sent using the other interfaces global scope address rather than the
local interface address. RFC 2236 suggests:
Ignore the Report if you cannot identify the source address of
the packet as belonging to a subnet assigned to the interface on
which the packet was received.
since such reports could be forged.
Look at the protocol when deciding if a RT_SCOPE_LINK address should
be used for the packet.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed