mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git
synced 2026-11-01 14:53:11 +01:00
Kevin Cernekee
7266507d89
Most SIP devices use a source port of 5060/udp on SIP requests, so the
response automatically comes back to port 5060:
phone_ip:5060 -> proxy_ip:5060 REGISTER
proxy_ip:5060 -> phone_ip:5060 100 Trying
The newer Cisco IP phones, however, use a randomly chosen high source
port for the SIP request but expect the response on port 5060:
phone_ip:49173 -> proxy_ip:5060 REGISTER
proxy_ip:5060 -> phone_ip:5060 100 Trying
Standard Linux NAT, with or without nf_nat_sip, will send the reply back
to port 49173, not 5060:
phone_ip:49173 -> proxy_ip:5060 REGISTER
proxy_ip:5060 -> phone_ip:49173 100 Trying
But the phone is not listening on 49173, so it will never see the reply.
This patch modifies nf_*_sip to work around this quirk by extracting
the SIP response port from the Via: header, iff the source IP in the
packet header matches the source IP in the SIP request.
Signed-off-by: Kevin Cernekee <[email protected]>
Acked-by: Eric Dumazet <[email protected]>
Cc: Patrick McHardy <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>