[NETFILTER]: nf_nat_sip: fix NAT setup order

We need to set up the destination NAT mapping before the source NAT
mapping, so the NAT core gets to see the final tuple and can decide
whether the source port needs to be remapped.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/netfilter/nf_nat_sip.c

@@ -224,17 +224,17 @@ static void ip_nat_sdp_expect(struct nf_conn *ct,
 	/* This must be a fresh one. */
 	BUG_ON(ct->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
-		= ct->master->tuplehash[!exp->dir].tuple.dst.u3.ip;
-	nf_nat_setup_info(ct, &range, IP_NAT_MANIP_SRC);
-
 	/* 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 = exp->saved_proto;
 	range.min_ip = range.max_ip = exp->saved_ip;
 	nf_nat_setup_info(ct, &range, IP_NAT_MANIP_DST);
+
+	/* Change src to where master sends to */
+	range.flags = IP_NAT_RANGE_MAP_IPS;
+	range.min_ip = range.max_ip
+		= ct->master->tuplehash[!exp->dir].tuple.dst.u3.ip;
+	nf_nat_setup_info(ct, &range, IP_NAT_MANIP_SRC);
 }
 
 /* So, this packet has hit the connection tracking matching code.