tree 652bb87e4f4be4132684bbf24c6f1437a53119b3
parent 2aab6b40b03154a263463a5d992ddd7d122a016a
author Kevin Cernekee <cernekee@chromium.org> 1512591147 -0800
committer David S. Miller <davem@davemloft.net> 1513011498 -0500

netlink: Add netns check on taps

Currently, a nlmon link inside a child namespace can observe systemwide
netlink activity.  Filter the traffic so that nlmon can only sniff
netlink messages from its own netns.

Test case:

    vpnns -- bash -c "ip link add nlmon0 type nlmon; \
                      ip link set nlmon0 up; \
                      tcpdump -i nlmon0 -q -w /tmp/nlmon.pcap -U" &
    sudo ip xfrm state add src 10.1.1.1 dst 10.1.1.2 proto esp \
        spi 0x1 mode transport \
        auth sha1 0x6162633132330000000000000000000000000000 \
        enc aes 0x00000000000000000000000000000000
    grep --binary abc123 /tmp/nlmon.pcap

Signed-off-by: Kevin Cernekee <cernekee@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>