map: ip4-map-t more RFC compliant

[vpp.git] / src / plugins / map / ip4_map_t.c

diff --git a/src/plugins/map/ip4_map_t.c b/src/plugins/map/ip4_map_t.c
index dca3284..d243a45 100644 (file)
--- a/src/plugins/map/ip4_map_t.c
+++ b/src/plugins/map/ip4_map_t.c
@@ -22,6 +22,7 @@ typedef enum
   IP4_MAPT_NEXT_MAPT_TCP_UDP,
   IP4_MAPT_NEXT_MAPT_ICMP,
   IP4_MAPT_NEXT_MAPT_FRAGMENTED,
+  IP4_MAPT_NEXT_ICMP_ERROR,
   IP4_MAPT_NEXT_DROP,
   IP4_MAPT_N_NEXT
 } ip4_mapt_next_t;
@@ -575,21 +576,31 @@ ip4_map_t (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
              goto exit;
            }
 
+         dst_port0 = -1;
+
          bool df0 =
            ip40->flags_and_fragment_offset &
            clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT);
 
+         vnet_buffer (p0)->map_t.mtu = d0->mtu ? d0->mtu : ~0;
+
          if (PREDICT_FALSE
-             (df0 && !map_main.frag_ignore_df && (ip4_len0 > d0->mtu)))
+             (df0 && !map_main.frag_ignore_df
+              &&
+              ((ip4_len0 +
+                (sizeof (ip6_header_t) - sizeof (ip4_header_t))) >
+               vnet_buffer (p0)->map_t.mtu)))
            {
-             p0->error = error_node->errors[MAP_ERROR_FRAGMENT_DROPPED];
-             next0 = IP4_MAPT_NEXT_DROP;
-             goto exit;
+             icmp4_error_set_vnet_buffer (p0, ICMP4_destination_unreachable,
+                                          ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
+                                          vnet_buffer (p0)->map_t.mtu -
+                                          (sizeof (ip6_header_t) -
+                                           sizeof (ip4_header_t)));
+             p0->error = error_node->errors[MAP_ERROR_DF_SET];
+             next0 = IP4_MAPT_NEXT_ICMP_ERROR;
+             goto trace;
            }
 
-         vnet_buffer (p0)->map_t.mtu = d0->mtu ? d0->mtu : ~0;
-
-         dst_port0 = -1;
          ip4_map_t_classify (p0, d0, ip40, ip4_len0, &dst_port0, &error0,
                              &next0, l4_dst_port);
 
@@ -626,7 +637,7 @@ ip4_map_t (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
 
          next0 = (error0 != MAP_ERROR_NONE) ? IP4_MAPT_NEXT_DROP : next0;
          p0->error = error_node->errors[error0];
-
+       trace:
          if (PREDICT_FALSE (p0->flags & VLIB_BUFFER_IS_TRACED))
            {
              map_add_trace (vm, node, p0, d0 - map_main.domains, dst_port0);
@@ -730,6 +741,7 @@ VLIB_REGISTER_NODE(ip4_map_t_node) = {
       [IP4_MAPT_NEXT_MAPT_TCP_UDP] = "ip4-map-t-tcp-udp",
       [IP4_MAPT_NEXT_MAPT_ICMP] = "ip4-map-t-icmp",
       [IP4_MAPT_NEXT_MAPT_FRAGMENTED] = "ip4-map-t-fragmented",
+      [IP4_MAPT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
       [IP4_MAPT_NEXT_DROP] = "error-drop",
   },
 };