From e6e4d9ed11fb1fab8b3256a3dc14d71b5e984ac4 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Mon, 16 May 2011 14:45:39 +0200 Subject: netfilter: nf_ct_sip: fix SDP parsing in TCP SIP messages for some Cisco phones Some Cisco phones do not place the Content-Length field at the end of the SIP message. This is valid, due to a misunderstanding of the specification the parser expects the SDP body to start directly after the Content-Length field. Fix the parser to scan for \r\n\r\n to locate the beginning of the SDP body. Reported-by: Teresa Kang Signed-off-by: Patrick McHardy --- net/netfilter/nf_conntrack_sip.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'net') diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c index 1f81abde131f..c05c0dc33499 100644 --- a/net/netfilter/nf_conntrack_sip.c +++ b/net/netfilter/nf_conntrack_sip.c @@ -1419,6 +1419,7 @@ static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff, const char *dptr, *end; s16 diff, tdiff = 0; int ret = NF_ACCEPT; + bool term; typeof(nf_nat_sip_seq_adjust_hook) nf_nat_sip_seq_adjust; if (ctinfo != IP_CT_ESTABLISHED && @@ -1453,10 +1454,15 @@ static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff, if (dptr + matchoff == end) break; - if (end + strlen("\r\n\r\n") > dptr + datalen) - break; - if (end[0] != '\r' || end[1] != '\n' || - end[2] != '\r' || end[3] != '\n') + term = false; + for (; end + strlen("\r\n\r\n") <= dptr + datalen; end++) { + if (end[0] == '\r' && end[1] == '\n' && + end[2] == '\r' && end[3] == '\n') { + term = true; + break; + } + } + if (!term) break; end += strlen("\r\n\r\n") + clen; -- cgit v1.2.3