lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[NETFILTER]: nf_conntrack_sip: create RTCP expectations

Browse Source 
Create expectations for the RTCP connections in addition to RTP connections.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy
2008-03-25 20:25:49 -07:00
committed by David S. Miller
parent d901a9369e
commit a9c1d35917
3 changed files with 64 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
net/ipv4/netfilter/nf_nat_sip.c
View File

@ -364,7 +364,8 @@ static unsigned int mangle_sdp(struct sk_buff *skb,
Mangle it, and change the expectation to match the new version. */
static unsigned int ip_nat_sdp(struct sk_buff *skb,
const char **dptr, unsigned int *datalen,
struct nf_conntrack_expect *exp)
struct nf_conntrack_expect *rtp_exp,
struct nf_conntrack_expect *rtcp_exp)
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
@ -375,31 +376,40 @@ static unsigned int ip_nat_sdp(struct sk_buff *skb,
/* Connection will come from reply */
if (ct->tuplehash[dir].tuple.src.u3.ip ==
ct->tuplehash[!dir].tuple.dst.u3.ip)
newip = exp->tuple.dst.u3.ip;
newip = rtp_exp->tuple.dst.u3.ip;
else
newip = ct->tuplehash[!dir].tuple.dst.u3.ip;
exp->saved_ip = exp->tuple.dst.u3.ip;
exp->tuple.dst.u3.ip = newip;
exp->saved_proto.udp.port = exp->tuple.dst.u.udp.port;
exp->dir = !dir;
rtp_exp->saved_ip = rtp_exp->tuple.dst.u3.ip;
rtp_exp->tuple.dst.u3.ip = newip;
rtp_exp->saved_proto.udp.port = rtp_exp->tuple.dst.u.udp.port;
rtp_exp->dir = !dir;
rtp_exp->expectfn = ip_nat_sip_expected;
/* When you see the packet, we need to NAT it the same as the
this one. */
exp->expectfn = ip_nat_sip_expected;
rtcp_exp->saved_ip = rtcp_exp->tuple.dst.u3.ip;
rtcp_exp->tuple.dst.u3.ip = newip;
rtcp_exp->saved_proto.udp.port = rtcp_exp->tuple.dst.u.udp.port;
rtcp_exp->dir = !dir;
rtcp_exp->expectfn = ip_nat_sip_expected;
/* Try to get same port: if not, try to change it. */
for (port = ntohs(exp->saved_proto.udp.port); port != 0; port++) {
exp->tuple.dst.u.udp.port = htons(port);
if (nf_ct_expect_related(exp) == 0)
/* Try to get same pair of ports: if not, try to change them. */
for (port = ntohs(rtp_exp->tuple.dst.u.udp.port);
port != 0; port += 2) {
rtp_exp->tuple.dst.u.udp.port = htons(port);
if (nf_ct_expect_related(rtp_exp) != 0)
continue;
rtcp_exp->tuple.dst.u.udp.port = htons(port + 1);
if (nf_ct_expect_related(rtcp_exp) == 0)
break;
nf_ct_unexpect_related(rtp_exp);
}
if (port == 0)
return NF_DROP;
if (!mangle_sdp(skb, ctinfo, ct, newip, port, dptr, datalen)) {
nf_ct_unexpect_related(exp);
nf_ct_unexpect_related(rtp_exp);
nf_ct_unexpect_related(rtcp_exp);
return NF_DROP;
}
return NF_ACCEPT;