+/* Forwarding declaration */
+void ip_conntrack_q931_expect(struct ip_conntrack *new,
+ struct ip_conntrack_expect *this);
+
+/****************************************************************************/
+static int expect_callforwarding(struct sk_buff **pskb,
+ struct ip_conntrack *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ TransportAddress * addr)
+{
+ int dir = CTINFO2DIR(ctinfo);
+ int ret = 0;
+ __be32 ip;
+ u_int16_t port;
+ struct ip_conntrack_expect *exp = NULL;
+ typeof(nat_callforwarding_hook) nat_callforwarding;
+
+ /* Read alternativeAddress */
+ if (!get_h225_addr(*data, addr, &ip, &port) || port == 0)
+ return 0;
+
+ /* If the calling party is on the same side of the forward-to party,
+ * we don't need to track the second call */
+ if (callforward_filter) {
+ struct rtable *rt1, *rt2;
+ struct flowi fl1 = {
+ .fl4_dst = ip,
+ };
+ struct flowi fl2 = {
+ .fl4_dst = ct->tuplehash[!dir].tuple.src.ip,
+ };
+
+ if (ip_route_output_key(&rt1, &fl1) == 0) {
+ if (ip_route_output_key(&rt2, &fl2) == 0) {
+ if (rt1->rt_gateway == rt2->rt_gateway &&
+ rt1->u.dst.dev == rt2->u.dst.dev)
+ ret = 1;
+ dst_release(&rt2->u.dst);
+ }
+ dst_release(&rt1->u.dst);
+ }
+ if (ret) {
+ DEBUGP("ip_ct_q931: Call Forwarding not tracked\n");
+ return 0;
+ }
+ }
+
+ /* Create expect for the second call leg */
+ if ((exp = ip_conntrack_expect_alloc(ct)) == NULL)
+ return -1;
+ exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
+ exp->tuple.src.u.tcp.port = 0;
+ exp->tuple.dst.ip = ip;
+ exp->tuple.dst.u.tcp.port = htons(port);
+ exp->tuple.dst.protonum = IPPROTO_TCP;
+ exp->mask.src.ip = htonl(0xFFFFFFFF);
+ exp->mask.src.u.tcp.port = 0;
+ exp->mask.dst.ip = htonl(0xFFFFFFFF);
+ exp->mask.dst.u.tcp.port = htons(0xFFFF);
+ exp->mask.dst.protonum = 0xFF;
+ exp->flags = 0;
+
+ if (ct->tuplehash[dir].tuple.src.ip !=
+ ct->tuplehash[!dir].tuple.dst.ip &&
+ (nat_callforwarding = rcu_dereference(nat_callforwarding_hook))) {
+ /* Need NAT */
+ ret = nat_callforwarding(pskb, ct, ctinfo, data, dataoff,
+ addr, port, exp);
+ } else { /* Conntrack only */
+ exp->expectfn = ip_conntrack_q931_expect;
+
+ if (ip_conntrack_expect_related(exp) == 0) {
+ DEBUGP("ip_ct_q931: expect Call Forwarding "
+ "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+ NIPQUAD(exp->tuple.src.ip),
+ ntohs(exp->tuple.src.u.tcp.port),
+ NIPQUAD(exp->tuple.dst.ip),
+ ntohs(exp->tuple.dst.u.tcp.port));
+ } else
+ ret = -1;
+ }
+
+ ip_conntrack_expect_put(exp);
+
+ return ret;
+}
+