tree b201af9b3832b3667d384fc2145d4255d42537aa
parent 9bc8d9b4e3b0229b0e9a8007cac49e1093e58f21
author Harout Hedeshian <harouth@codeaurora.org> 1434415279 -0600
committer Lorenzo Colitti <lorenzo@google.com> 1437412170 +0900

extensions: libxt_socket: add --restore-skmark option

xt_socket is useful for matching sockets with IP_TRANSPARENT and
taking some action on the matching packets. However, it lacks the
ability to match only a small subset of transparent sockets.

Suppose there are 2 applications, each with its own set of transparent
sockets. The first application wants all matching packets dropped,
while the second application wants them forwarded somewhere else.

Add the ability to retore the skb->mark from the sk_mark. The mark
is only restored if a matching socket is found and the transparent /
nowildcard conditions are satisfied.

Now the 2 hypothetical applications can differentiate their sockets
based on a mark value set with SO_MARK.

iptables -t mangle -I PREROUTING -m socket --transparent \
                                           --restore-skmark -j action
iptables -t mangle -A action -m mark --mark 10 -j action2
iptables -t mangle -A action -m mark --mark 11 -j action3

Signed-off-by: Harout Hedeshian <harouth@codeaurora.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Change-Id: I8f95f053bf32181bf0928f0a86f594212a1c767b