nat: respect udp checksum

[vpp.git] / src / plugins / nat / nat_det_in2out.c

diff --git a/src/plugins/nat/nat_det_in2out.c b/src/plugins/nat/nat_det_in2out.c
index 918e1f5..832a2ba 100644 (file)
--- a/src/plugins/nat/nat_det_in2out.c
+++ b/src/plugins/nat/nat_det_in2out.c
@@ -392,7 +392,8 @@ VLIB_NODE_FN (snat_det_in2out_node) (vlib_main_t * vm,
                }
            }
 
-         new_port0 = ses0->out.out_port;
+         old_port0 = udp0->src_port;
+         udp0->src_port = new_port0 = ses0->out.out_port;
 
          old_addr0.as_u32 = ip0->src_address.as_u32;
          ip0->src_address.as_u32 = new_addr0.as_u32;
@@ -424,9 +425,6 @@ VLIB_NODE_FN (snat_det_in2out_node) (vlib_main_t * vm,
                       && ses0->state == SNAT_SESSION_UNKNOWN)
                ses0->state = SNAT_SESSION_TCP_ESTABLISHED;
 
-             old_port0 = tcp0->src;
-             tcp0->src = new_port0;
-
              sum0 = tcp0->checksum;
              sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
                                     ip4_header_t,
@@ -440,9 +438,20 @@ VLIB_NODE_FN (snat_det_in2out_node) (vlib_main_t * vm,
          else
            {
              ses0->state = SNAT_SESSION_UDP_ACTIVE;
-             old_port0 = udp0->src_port;
-             udp0->src_port = new_port0;
-             udp0->checksum = 0;
+
+             if (PREDICT_FALSE (udp0->checksum))
+               {
+                 sum0 = udp0->checksum;
+                 sum0 =
+                   ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
+                                   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);
+               }
            }
 
          switch (ses0->state)
@@ -556,7 +565,8 @@ VLIB_NODE_FN (snat_det_in2out_node) (vlib_main_t * vm,
                }
            }
 
-         new_port1 = ses1->out.out_port;
+         old_port1 = udp1->src_port;
+         udp1->src_port = new_port1 = ses1->out.out_port;
 
          old_addr1.as_u32 = ip1->src_address.as_u32;
          ip1->src_address.as_u32 = new_addr1.as_u32;
@@ -588,9 +598,6 @@ VLIB_NODE_FN (snat_det_in2out_node) (vlib_main_t * vm,
                       && ses1->state == SNAT_SESSION_UNKNOWN)
                ses1->state = SNAT_SESSION_TCP_ESTABLISHED;
 
-             old_port1 = tcp1->src;
-             tcp1->src = new_port1;
-
              sum1 = tcp1->checksum;
              sum1 = ip_csum_update (sum1, old_addr1.as_u32, new_addr1.as_u32,
                                     ip4_header_t,
@@ -604,9 +611,20 @@ VLIB_NODE_FN (snat_det_in2out_node) (vlib_main_t * vm,
          else
            {
              ses1->state = SNAT_SESSION_UDP_ACTIVE;
-             old_port1 = udp1->src_port;
-             udp1->src_port = new_port1;
-             udp1->checksum = 0;
+
+             if (PREDICT_FALSE (udp1->checksum))
+               {
+                 sum1 = udp1->checksum;
+                 sum1 =
+                   ip_csum_update (sum1, old_addr1.as_u32, new_addr1.as_u32,
+                                   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);
+               }
            }
 
          switch (ses1->state)
@@ -756,7 +774,8 @@ VLIB_NODE_FN (snat_det_in2out_node) (vlib_main_t * vm,
                }
            }
 
-         new_port0 = ses0->out.out_port;
+         old_port0 = udp0->src_port;
+         udp0->src_port = new_port0 = ses0->out.out_port;
 
          old_addr0.as_u32 = ip0->src_address.as_u32;
          ip0->src_address.as_u32 = new_addr0.as_u32;
@@ -788,9 +807,6 @@ VLIB_NODE_FN (snat_det_in2out_node) (vlib_main_t * vm,
                       && ses0->state == SNAT_SESSION_UNKNOWN)
                ses0->state = SNAT_SESSION_TCP_ESTABLISHED;
 
-             old_port0 = tcp0->src;
-             tcp0->src = new_port0;
-
              sum0 = tcp0->checksum;
              sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
                                     ip4_header_t,
@@ -804,9 +820,20 @@ VLIB_NODE_FN (snat_det_in2out_node) (vlib_main_t * vm,
          else
            {
              ses0->state = SNAT_SESSION_UDP_ACTIVE;
-             old_port0 = udp0->src_port;
-             udp0->src_port = new_port0;
-             udp0->checksum = 0;
+
+             if (PREDICT_FALSE (udp0->checksum))
+               {
+                 sum0 = udp0->checksum;
+                 sum0 =
+                   ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
+                                   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);
+               }
            }
 
          switch (ses0->state)