nat: respect udp checksum

[vpp.git] / src / plugins / nat / nat_det_out2in.c

diff --git a/src/plugins/nat/nat_det_out2in.c b/src/plugins/nat/nat_det_out2in.c
index 45fba18..c4bd096 100644 (file)
--- a/src/plugins/nat/nat_det_out2in.c
+++ b/src/plugins/nat/nat_det_out2in.c
@@ -343,7 +343,8 @@ VLIB_NODE_FN (snat_det_out2in_node) (vlib_main_t * vm,
              b0->error = node->errors[NAT_DET_OUT2IN_ERROR_NO_TRANSLATION];
              goto trace0;
            }
-         new_port0 = ses0->in_port;
+         old_port0 = udp0->dst_port;
+         udp0->dst_port = new_port0 = ses0->in_port;
 
          old_addr0 = ip0->dst_address;
          ip0->dst_address = new_addr0;
@@ -364,24 +365,25 @@ VLIB_NODE_FN (snat_det_out2in_node) (vlib_main_t * vm,
                       && ses0->state == SNAT_SESSION_TCP_LAST_ACK)
                snat_det_ses_close (dm0, ses0);
 
-             old_port0 = tcp0->dst;
-             tcp0->dst = new_port0;
-
              sum0 = tcp0->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 */ );
              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.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);
            }
 
        trace0:
@@ -462,7 +464,8 @@ VLIB_NODE_FN (snat_det_out2in_node) (vlib_main_t * vm,
              b1->error = node->errors[NAT_DET_OUT2IN_ERROR_NO_TRANSLATION];
              goto trace1;
            }
-         new_port1 = ses1->in_port;
+         old_port1 = udp1->dst_port;
+         udp1->dst_port = new_port1 = ses1->in_port;
 
          old_addr1 = ip1->dst_address;
          ip1->dst_address = new_addr1;
@@ -483,24 +486,25 @@ VLIB_NODE_FN (snat_det_out2in_node) (vlib_main_t * vm,
                       && ses1->state == SNAT_SESSION_TCP_LAST_ACK)
                snat_det_ses_close (dm1, ses1);
 
-             old_port1 = tcp1->dst;
-             tcp1->dst = new_port1;
-
              sum1 = tcp1->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 */ );
              tcp1->checksum = ip_csum_fold (sum1);
            }
-         else
+         else if (udp1->checksum)
            {
-             old_port1 = udp1->dst_port;
-             udp1->dst_port = new_port1;
-             udp1->checksum = 0;
+             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);
            }
 
        trace1:
@@ -614,7 +618,8 @@ VLIB_NODE_FN (snat_det_out2in_node) (vlib_main_t * vm,
              b0->error = node->errors[NAT_DET_OUT2IN_ERROR_NO_TRANSLATION];
              goto trace00;
            }
-         new_port0 = ses0->in_port;
+         old_port0 = udp0->dst_port;
+         udp0->dst_port = new_port0 = ses0->in_port;
 
          old_addr0 = ip0->dst_address;
          ip0->dst_address = new_addr0;
@@ -635,24 +640,25 @@ VLIB_NODE_FN (snat_det_out2in_node) (vlib_main_t * vm,
                       && ses0->state == SNAT_SESSION_TCP_LAST_ACK)
                snat_det_ses_close (dm0, ses0);
 
-             old_port0 = tcp0->dst;
-             tcp0->dst = new_port0;
-
              sum0 = tcp0->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 */ );
              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.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);
            }
 
        trace00: