+/****************************************************************************/
+static void ip_nat_callforwarding_expect(struct ip_conntrack *new,
+ struct ip_conntrack_expect *this)
+{
+ struct ip_nat_range range;
+
+ /* This must be a fresh one. */
+ BUG_ON(new->status & IPS_NAT_DONE_MASK);
+
+ /* Change src to where master sends to */
+ range.flags = IP_NAT_RANGE_MAP_IPS;
+ range.min_ip = range.max_ip = new->tuplehash[!this->dir].tuple.src.ip;
+
+ /* hook doesn't matter, but it has to do source manip */
+ ip_nat_setup_info(new, &range, NF_IP_POST_ROUTING);
+
+ /* For DST manip, map port here to where it's expected. */
+ range.flags = (IP_NAT_RANGE_MAP_IPS | IP_NAT_RANGE_PROTO_SPECIFIED);
+ range.min = range.max = this->saved_proto;
+ range.min_ip = range.max_ip = this->saved_ip;
+
+ /* hook doesn't matter, but it has to do destination manip */
+ ip_nat_setup_info(new, &range, NF_IP_PRE_ROUTING);
+
+ ip_conntrack_q931_expect(new, this);
+}
+
+/****************************************************************************/
+static int nat_callforwarding(struct sk_buff **pskb, struct ip_conntrack *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ TransportAddress * addr, u_int16_t port,
+ struct ip_conntrack_expect *exp)
+{
+ int dir = CTINFO2DIR(ctinfo);
+ u_int16_t nated_port;
+
+ /* Set expectations for NAT */
+ exp->saved_ip = exp->tuple.dst.ip;
+ exp->tuple.dst.ip = ct->tuplehash[!dir].tuple.dst.ip;
+ exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
+ exp->expectfn = ip_nat_callforwarding_expect;
+ exp->dir = !dir;
+
+ /* Try to get same port: if not, try to change it. */
+ for (nated_port = port; nated_port != 0; nated_port++) {
+ exp->tuple.dst.u.tcp.port = htons(nated_port);
+ if (ip_conntrack_expect_related(exp) == 0)
+ break;
+ }
+
+ if (nated_port == 0) { /* No port available */
+ if (net_ratelimit())
+ printk("ip_nat_q931: out of TCP ports\n");
+ return 0;
+ }
+
+ /* Modify signal */
+ if (!set_h225_addr(pskb, data, dataoff, addr,
+ ct->tuplehash[!dir].tuple.dst.ip,
+ nated_port) == 0) {
+ ip_conntrack_unexpect_related(exp);
+ return -1;
+ }
+
+ /* Success */
+ DEBUGP("ip_nat_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));
+
+ return 0;
+}
+