VPP-1283: IPv6 PMTU missing MTU value in ICMP6 message.

[vpp.git] / src / vnet / ip / ip6_forward.c

diff --git a/src/vnet/ip/ip6_forward.c b/src/vnet/ip/ip6_forward.c
index c45b65f..f4c51e2 100644 (file)
--- a/src/vnet/ip/ip6_forward.c
+++ b/src/vnet/ip/ip6_forward.c
@@ -1561,6 +1561,19 @@ typedef enum
  */
 #define IP6_MCAST_ADDR_MASK 0xffffffff
 
+always_inline void
+ip6_mtu_check (vlib_buffer_t * b, u16 packet_bytes,
+              u16 adj_packet_bytes, u32 * next, u32 * error)
+{
+  if (adj_packet_bytes >= 1280 && packet_bytes > adj_packet_bytes)
+    {
+      *error = IP6_ERROR_MTU_EXCEEDED;
+      icmp6_error_set_vnet_buffer (b, ICMP6_packet_too_big, 0,
+                                  adj_packet_bytes);
+      *next = IP6_REWRITE_NEXT_ICMP_ERROR;
+    }
+}
+
 always_inline uword
 ip6_rewrite_inline (vlib_main_t * vm,
                    vlib_node_runtime_t * node,
@@ -1706,16 +1719,14 @@ ip6_rewrite_inline (vlib_main_t * vm,
            }
 
          /* Check MTU of outgoing interface. */
-         error0 =
-           (vlib_buffer_length_in_chain (vm, p0) >
-            adj0[0].
-            rewrite_header.max_l3_packet_bytes ? IP6_ERROR_MTU_EXCEEDED :
-            error0);
-         error1 =
-           (vlib_buffer_length_in_chain (vm, p1) >
-            adj1[0].
-            rewrite_header.max_l3_packet_bytes ? IP6_ERROR_MTU_EXCEEDED :
-            error1);
+         ip6_mtu_check (p0, clib_net_to_host_u16 (ip0->payload_length) +
+                        sizeof (ip6_header_t),
+                        adj0[0].rewrite_header.max_l3_packet_bytes,
+                        &next0, &error0);
+         ip6_mtu_check (p1, clib_net_to_host_u16 (ip1->payload_length) +
+                        sizeof (ip6_header_t),
+                        adj1[0].rewrite_header.max_l3_packet_bytes,
+                        &next1, &error1);
 
          /* Don't adjust the buffer for hop count issue; icmp-error node
           * wants to see the IP headerr */
@@ -1849,14 +1860,13 @@ ip6_rewrite_inline (vlib_main_t * vm,
            }
 
          /* Check MTU of outgoing interface. */
-         error0 =
-           (vlib_buffer_length_in_chain (vm, p0) >
-            adj0[0].
-            rewrite_header.max_l3_packet_bytes ? IP6_ERROR_MTU_EXCEEDED :
-            error0);
+         ip6_mtu_check (p0, clib_net_to_host_u16 (ip0->payload_length) +
+                        sizeof (ip6_header_t),
+                        adj0[0].rewrite_header.max_l3_packet_bytes,
+                        &next0, &error0);
 
          /* Don't adjust the buffer for hop count issue; icmp-error node
-          * wants to see the IP headerr */
+          * wants to see the IP header */
          if (PREDICT_TRUE (error0 == IP6_ERROR_NONE))
            {
              p0->current_data -= rw_len0;