nat: fix dual-loop tcp checksum botch

Type: fix
Fixes: 22921

Signed-off-by: Dave Barach <dave@barachs.net>
Change-Id: I4fecce96d027c0ee1797d9d84cfab94b1ecdc02b

diff --git a/src/plugins/nat/out2in.c b/src/plugins/nat/out2in.c
index 83c099d..9549a45 100755 (executable)
--- a/src/plugins/nat/out2in.c
+++ b/src/plugins/nat/out2in.c
@@ -893,9 +893,6 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
                                 dst_address /* changed member */ );
          ip0->checksum = ip_csum_fold (sum0);
 
-         old_port0 = udp0->dst_port;
-         new_port0 = udp0->dst_port = s0->in2out.port;
-
          if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
            {
              old_port0 = tcp0->dst_port;
@@ -917,6 +914,9 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
            {
              if (PREDICT_FALSE (udp0->checksum))
                {
+                 old_port0 = udp0->dst_port;
+                 new_port0 = udp0->dst_port = s0->in2out.port;
+
                  sum0 = udp0->checksum;
                  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
                                         ip4_header_t,
@@ -1070,11 +1070,12 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
                                 dst_address /* changed member */ );
          ip1->checksum = ip_csum_fold (sum1);
 
-         old_port1 = udp1->dst_port;
-         new_port1 = udp1->dst_port = s1->in2out.port;
-
          if (PREDICT_TRUE (proto1 == SNAT_PROTOCOL_TCP))
            {
+             old_port1 = tcp1->dst_port;
+             tcp1->dst_port = s1->in2out.port;
+             new_port1 = tcp1->dst_port;
+
              sum1 = tcp1->checksum;
              sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
                                     ip4_header_t,
@@ -1090,6 +1091,9 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
            {
              if (PREDICT_FALSE (udp1->checksum))
                {
+                 old_port1 = udp1->dst_port;
+                 new_port1 = udp1->dst_port = s1->in2out.port;
+
                  sum1 = udp1->checksum;
                  sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
                                         ip4_header_t,
@@ -1280,11 +1284,12 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
                                 dst_address /* changed member */ );
          ip0->checksum = ip_csum_fold (sum0);
 
-         old_port0 = udp0->dst_port;
-         new_port0 = udp0->dst_port = s0->in2out.port;
-
          if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
            {
+             old_port0 = tcp0->dst_port;
+             tcp0->dst_port = s0->in2out.port;
+             new_port0 = tcp0->dst_port;
+
              sum0 = tcp0->checksum;
              sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
                                     ip4_header_t,
@@ -1300,6 +1305,9 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
            {
              if (PREDICT_FALSE (udp0->checksum))
                {
+                 old_port0 = udp0->dst_port;
+                 new_port0 = udp0->dst_port = s0->in2out.port;
+
                  sum0 = udp0->checksum;
                  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
                                         ip4_header_t,