nat: respect udp checksum

[vpp.git] / src / plugins / nat / out2in.c

diff --git a/src/plugins/nat/out2in.c b/src/plugins/nat/out2in.c
index 8c6cb48..83c099d 100755 (executable)
--- a/src/plugins/nat/out2in.c
+++ b/src/plugins/nat/out2in.c
@@ -893,6 +893,9 @@ 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;
@@ -912,9 +915,17 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
            }
          else
            {
-             old_port0 = udp0->dst_port;
-             udp0->dst_port = s0->in2out.port;
-             udp0->checksum = 0;
+             if (PREDICT_FALSE (udp0->checksum))
+               {
+                 sum0 = udp0->checksum;
+                 sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                        ip4_header_t,
+                                        dst_address /* changed member */ );
+                 sum0 = ip_csum_update (sum0, old_port0, new_port0,
+                                        ip4_header_t /* cheat */ ,
+                                        length /* changed member */ );
+                 udp0->checksum = ip_csum_fold (sum0);
+               }
              udp_packets++;
            }
 
@@ -1059,12 +1070,11 @@ 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,
@@ -1078,9 +1088,17 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
            }
          else
            {
-             old_port1 = udp1->dst_port;
-             udp1->dst_port = s1->in2out.port;
-             udp1->checksum = 0;
+             if (PREDICT_FALSE (udp1->checksum))
+               {
+                 sum1 = udp1->checksum;
+                 sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
+                                        ip4_header_t,
+                                        dst_address /* changed member */ );
+                 sum1 = ip_csum_update (sum1, old_port1, new_port1,
+                                        ip4_header_t /* cheat */ ,
+                                        length /* changed member */ );
+                 udp1->checksum = ip_csum_fold (sum1);
+               }
              udp_packets++;
            }
 
@@ -1262,12 +1280,11 @@ 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,
@@ -1281,9 +1298,17 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
            }
          else
            {
-             old_port0 = udp0->dst_port;
-             udp0->dst_port = s0->in2out.port;
-             udp0->checksum = 0;
+             if (PREDICT_FALSE (udp0->checksum))
+               {
+                 sum0 = udp0->checksum;
+                 sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                        ip4_header_t,
+                                        dst_address /* changed member */ );
+                 sum0 = ip_csum_update (sum0, old_port0, new_port0,
+                                        ip4_header_t /* cheat */ ,
+                                        length /* changed member */ );
+                 udp0->checksum = ip_csum_fold (sum0);
+               }
              udp_packets++;
            }
 
@@ -1573,12 +1598,11 @@ VLIB_NODE_FN (nat44_out2in_reass_node) (vlib_main_t * vm,
 
          if (PREDICT_FALSE (ip4_is_first_fragment (ip0)))
            {
+             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,
@@ -1589,11 +1613,16 @@ VLIB_NODE_FN (nat44_out2in_reass_node) (vlib_main_t * vm,
                                         length /* changed member */ );
                  tcp0->checksum = ip_csum_fold (sum0);
                }
-             else
+             else if (udp0->checksum)
                {
-                 old_port0 = udp0->dst_port;
-                 udp0->dst_port = s0->in2out.port;
-                 udp0->checksum = 0;
+                 sum0 = udp0->checksum;
+                 sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                        ip4_header_t,
+                                        dst_address /* changed member */ );
+                 sum0 = ip_csum_update (sum0, old_port0, new_port0,
+                                        ip4_header_t /* cheat */ ,
+                                        length /* changed member */ );
+                 udp0->checksum = ip_csum_fold (sum0);
                }
            }
 
@@ -1797,26 +1826,30 @@ VLIB_NODE_FN (snat_out2in_fast_node) (vlib_main_t * vm,
 
          if (PREDICT_FALSE (new_port0 != udp0->dst_port))
            {
+             old_port0 = udp0->dst_port;
+             udp0->dst_port = new_port0;
+
              if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
                {
-                 old_port0 = tcp0->dst_port;
-                 tcp0->dst_port = new_port0;
-
                  sum0 = tcp0->checksum;
                  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
                                         ip4_header_t,
                                         dst_address /* changed member */ );
-
                  sum0 = ip_csum_update (sum0, old_port0, new_port0,
                                         ip4_header_t /* cheat */ ,
                                         length /* changed member */ );
                  tcp0->checksum = ip_csum_fold (sum0);
                }
-             else
+             else if (udp0->checksum)
                {
-                 old_port0 = udp0->dst_port;
-                 udp0->dst_port = new_port0;
-                 udp0->checksum = 0;
+                 sum0 = udp0->checksum;
+                 sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                        ip4_header_t,
+                                        dst_address /* changed member */ );
+                 sum0 = ip_csum_update (sum0, old_port0, new_port0,
+                                        ip4_header_t /* cheat */ ,
+                                        length /* changed member */ );
+                 udp0->checksum = ip_csum_fold (sum0);
                }
            }
          else
@@ -1827,9 +1860,16 @@ VLIB_NODE_FN (snat_out2in_fast_node) (vlib_main_t * vm,
                  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
                                         ip4_header_t,
                                         dst_address /* changed member */ );
-
                  tcp0->checksum = ip_csum_fold (sum0);
                }
+             else if (udp0->checksum)
+               {
+                 sum0 = udp0->checksum;
+                 sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                        ip4_header_t,
+                                        dst_address /* changed member */ );
+                 udp0->checksum = ip_csum_fold (sum0);
+               }
            }
 
        trace00: