Commit e6e4d9ed authored by Patrick McHardy's avatar Patrick McHardy

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: default avatarTeresa Kang <teresa_kang@gemtek.com.tw>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent 274ea0e2
...@@ -1419,6 +1419,7 @@ static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff, ...@@ -1419,6 +1419,7 @@ static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff,
const char *dptr, *end; const char *dptr, *end;
s16 diff, tdiff = 0; s16 diff, tdiff = 0;
int ret = NF_ACCEPT; int ret = NF_ACCEPT;
bool term;
typeof(nf_nat_sip_seq_adjust_hook) nf_nat_sip_seq_adjust; typeof(nf_nat_sip_seq_adjust_hook) nf_nat_sip_seq_adjust;
if (ctinfo != IP_CT_ESTABLISHED && if (ctinfo != IP_CT_ESTABLISHED &&
...@@ -1453,10 +1454,15 @@ static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff, ...@@ -1453,10 +1454,15 @@ static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff,
if (dptr + matchoff == end) if (dptr + matchoff == end)
break; break;
if (end + strlen("\r\n\r\n") > dptr + datalen) term = false;
break; for (; end + strlen("\r\n\r\n") <= dptr + datalen; end++) {
if (end[0] != '\r' || end[1] != '\n' || if (end[0] == '\r' && end[1] == '\n' &&
end[2] != '\r' || end[3] != '\n') end[2] == '\r' && end[3] == '\n') {
term = true;
break;
}
}
if (!term)
break; break;
end += strlen("\r\n\r\n") + clen; end += strlen("\r\n\r\n") + clen;
......
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