On Mon, Dec 11, 2017 at 11:13:45AM -0800, Kevin Cernekee wrote:
> Closing a multicast socket after the final IPv4 address is deleted
> from an interface can generate a membership report that uses the
> source IP from a different interface. The following test script, run
> from an isolated netns, reproduces the issue:
>
> #!/bin/bash
>
> ip link add dummy0 type dummy
> ip link add dummy1 type dummy
> ip link set dummy0 up
> ip link set dummy1 up
> ip addr add 10.1.1.1/24 dev dummy0
> ip addr add 192.168.99.99/24 dev dummy1
>
> tcpdump -U -i dummy0 &
> socat EXEC:"sleep 2" \
> UDP4-DATAGRAM:239.101.1.68:8889,ip-add-membership=239.0.1.68:10.1.1.1
> &
>
> sleep 1
> ip addr del 10.1.1.1/24 dev dummy0
> sleep 5
> kill %tcpdump
>
> RFC 3376 specifies that the report must be sent with a valid IP source
> address from the destination subnet, or from address 0.0.0.0. Add an
> extra check to make sure this is the case.
>
> Signed-off-by: Kevin Cernekee <cerne...@chromium.org>
Reviewed-by: Andrew Lunn <and...@lunn.ch>
Andrew
