From mboxrd@z Thu Jan 1 00:00:00 1970 From: pablo@netfilter.org Subject: [PATCH 2/2] netfilter: nf_ct_h323: fix bug in rtcp natting Date: Tue, 12 Jun 2012 19:36:03 +0200 Message-ID: <1339522563-9227-3-git-send-email-pablo@netfilter.org> References: <1339522563-9227-1-git-send-email-pablo@netfilter.org> Cc: davem@davemloft.net, netdev@vger.kernel.org To: netfilter-devel@vger.kernel.org Return-path: In-Reply-To: <1339522563-9227-1-git-send-email-pablo@netfilter.org> Sender: netdev-owner@vger.kernel.org List-Id: netfilter-devel.vger.kernel.org From: Pablo Neira Ayuso The nat_rtp_rtcp hook takes two separate parameters port and rtp_port. port is expected to be the real h245 address (found inside the packet). rtp_port is the even number closest to port (RTP ports are even and RTCP ports are odd). However currently, both port and rtp_port are having same value (both are rounded to nearest even numbers). This works well in case of openlogicalchannel with media (RTP/even) port. But in case of openlogicalchannel for media control (RTCP/odd) port, h245 address in the packet is wrongly modified to have an even port. I am attaching a pcap demonstrating the problem, for any further analysis. This behavior was introduced around v2.6.19 while rewriting the helper. Signed-off-by: Jagdish Motwani Signed-off-by: Sanket Shah Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_h323_main.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/net/netfilter/nf_conntrack_h323_main.c b/net/netfilter/nf_conntrack_h323_main.c index 46d69d7..31f50bc 100644 --- a/net/netfilter/nf_conntrack_h323_main.c +++ b/net/netfilter/nf_conntrack_h323_main.c @@ -270,9 +270,8 @@ static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct, return 0; /* RTP port is even */ - port &= htons(~1); - rtp_port = port; - rtcp_port = htons(ntohs(port) + 1); + rtp_port = port & ~htons(1); + rtcp_port = port | htons(1); /* Create expect for RTP */ if ((rtp_exp = nf_ct_expect_alloc(ct)) == NULL) -- 1.7.10