/* So, this packet has hit the connection tracking matching code.
Mangle it, and change the expectation to match the new version. */
static unsigned int ip_nat_sdp(struct sk_buff **pskb,
enum ip_conntrack_info ctinfo,
struct nf_conntrack_expect *exp,
const char *dptr)
{
struct nf_conn *ct = exp->master;
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
__be32 newip;
u_int16_t port;
/* 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;
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;
/* When you see the packet, we need to NAT it the same as the
this one. */
exp->expectfn = ip_nat_sdp_expect;
/* 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_conntrack_expect_related(exp) == 0)
break;
}
if (port == 0)
return NF_DROP;
if (!mangle_sdp(pskb, ctinfo, ct, newip, port, dptr)) {
nf_conntrack_unexpect_related(exp);
return NF_DROP;
}
return NF_ACCEPT;
}
/* So, this packet has hit the connection tracking matching code.
Mangle it, and change the expectation to match the new version. */
static unsigned int ip_nat_sdp(struct sk_buff **pskb,
enum ip_conntrack_info ctinfo,
struct nf_conntrack_expect *exp,
const char *dptr)
{
struct nf_conn *ct = exp->master;
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
__be32 newip;
u_int16_t port;
DEBUGP("ip_nat_sdp():\n");
#if 0
/* Connection will come from reply */
newip = ct->tuplehash[!dir].tuple.dst.u3.ip;
//printk("newip :0x%08lx \n",newip);
#else
/*20091028 pork patch: according to 2.6.24, modify SDP error as registering*/
if (ct->tuplehash[dir].tuple.src.u3.ip ==
ct->tuplehash[!dir].tuple.dst.u3.ip){
newip = exp->tuple.dst.u3.ip;
/*printk("newip :0x%08lx \n",newip);*/
}
else{
newip = ct->tuplehash[!dir].tuple.dst.u3.ip;
/*printk("newip :0x%08lx \n",newip);*/
}
#endif
exp->tuple.dst.u3.ip = newip;
exp->saved_proto.udp.port = exp->tuple.dst.u.udp.port;
exp->dir = !dir;
/* When you see the packet, we need to NAT it the same as the
this one. */
exp->expectfn = nf_nat_follow_master;
/* Try to get same port: if not, try to change it. */
for (port = ntohs(exp->saved_proto.udp.port); port != 0; port++) {
int ret;
exp->tuple.dst.u.udp.port = htons(port);
ret = nf_conntrack_expect_related(exp);
if (ret == 0)
break;
else if (ret != -EBUSY) {
port = 0;
break;
}
}
if (port == 0){
return NF_DROP;
}
/*printk("new port :%d \n", htons(port));*/
if (!mangle_sdp(pskb, ctinfo, ct, newip, port, dptr)) {
nf_conntrack_unexpect_related(exp);
return NF_DROP;
}
return NF_ACCEPT;
}
