ICMP46 error: Clone first buffer instead of "truncating" original buffer

[vpp.git] / src / vnet / ip / icmp4.c

diff --git a/src/vnet/ip/icmp4.c b/src/vnet/ip/icmp4.c
index bbeab32..ce81dc0 100644 (file)
--- a/src/vnet/ip/icmp4.c
+++ b/src/vnet/ip/icmp4.c
@@ -219,7 +219,7 @@ VLIB_REGISTER_NODE (ip4_icmp_input_node,static) = {
 
   .n_next_nodes = 1,
   .next_nodes = {
-    [ICMP_INPUT_NEXT_ERROR] = "error-punt",
+    [ICMP_INPUT_NEXT_ERROR] = "ip4-punt",
   },
 };
 /* *INDENT-ON* */
@@ -476,15 +476,29 @@ ip4_icmp_error (vlib_main_t * vm,
 
       while (n_left_from > 0 && n_left_to_next > 0)
        {
-         u32 pi0 = from[0];
+         /*
+          * Duplicate first buffer and free the original chain.  Keep
+          * as much of the original packet as possible, within the
+          * minimum MTU. We chat "a little" here by keeping whatever
+          * is available in the first buffer.
+          */
+
+         u32 pi0 = ~0;
+         u32 org_pi0 = from[0];
          u32 next0 = IP4_ICMP_ERROR_NEXT_LOOKUP;
          u8 error0 = ICMP4_ERROR_NONE;
-         vlib_buffer_t *p0;
+         vlib_buffer_t *p0, *org_p0;
          ip4_header_t *ip0, *out_ip0;
          icmp46_header_t *icmp0;
          u32 sw_if_index0, if_add_index0;
          ip_csum_t sum;
 
+         org_p0 = vlib_get_buffer (vm, org_pi0);
+         p0 = vlib_buffer_copy_no_chain (vm, org_p0, &pi0);
+         vlib_buffer_free_one (vm, org_pi0);
+         if (!p0 || pi0 == ~0) /* Out of buffers */
+           continue;
+
          /* Speculatively enqueue p0 to the current next frame */
          to_next[0] = pi0;
          from += 1;
@@ -492,34 +506,16 @@ ip4_icmp_error (vlib_main_t * vm,
          n_left_from -= 1;
          n_left_to_next -= 1;
 
-         p0 = vlib_get_buffer (vm, pi0);
          ip0 = vlib_buffer_get_current (p0);
          sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
 
-         /*
-          * RFC1812 says to keep as much of the original packet as
-          * possible within the minimum MTU (576). We cheat "a little"
-          * here by keeping whatever fits in the first buffer, to be more
-          * efficient
-          */
-         if (PREDICT_FALSE (p0->total_length_not_including_first_buffer))
-           {
-             /* clear current_length of all other buffers in chain */
-             vlib_buffer_t *b = p0;
-             p0->total_length_not_including_first_buffer = 0;
-             while (b->flags & VLIB_BUFFER_NEXT_PRESENT)
-               {
-                 b = vlib_get_buffer (vm, b->next_buffer);
-                 b->current_length = 0;
-               }
-           }
-         p0->current_length =
-           p0->current_length > 576 ? 576 : p0->current_length;
-
          /* Add IP header and ICMPv4 header including a 4 byte data field */
          vlib_buffer_advance (p0,
                               -sizeof (ip4_header_t) -
                               sizeof (icmp46_header_t) - 4);
+
+         p0->current_length =
+           p0->current_length > 576 ? 576 : p0->current_length;
          out_ip0 = vlib_buffer_get_current (p0);
          icmp0 = (icmp46_header_t *) & out_ip0[1];
 
@@ -568,6 +564,7 @@ ip4_icmp_error (vlib_main_t * vm,
          /* Update error status */
          if (error0 == ICMP4_ERROR_NONE)
            error0 = icmp4_icmp_type_to_error (icmp0->type);
+
          vlib_error_count (vm, node->node_index, error0, 1);
 
          /* Verify speculative enqueue, maybe switch current next frame */
@@ -592,7 +589,7 @@ VLIB_REGISTER_NODE (ip4_icmp_error_node) = {
 
   .n_next_nodes = IP4_ICMP_ERROR_N_NEXT,
   .next_nodes = {
-    [IP4_ICMP_ERROR_NEXT_DROP] = "error-drop",
+    [IP4_ICMP_ERROR_NEXT_DROP] = "ip4-drop",
     [IP4_ICMP_ERROR_NEXT_LOOKUP] = "ip4-lookup",
   },
 
@@ -651,7 +648,13 @@ icmp4_pg_edit_function (pg_main_t * pg,
       ASSERT (p0->current_data == 0);
       ip0 = (void *) (p0->data + ip_offset);
       icmp0 = (void *) (p0->data + icmp_offset);
-      len0 = clib_net_to_host_u16 (ip0->length) - ip4_header_bytes (ip0);
+
+      /* if IP length has been specified, then calculate the length based on buffer */
+      if (ip0->length == 0)
+       len0 = vlib_buffer_length_in_chain (vm, p0) - icmp_offset;
+      else
+       len0 = clib_net_to_host_u16 (ip0->length) - icmp_offset;
+
       icmp0->checksum =
        ~ip_csum_fold (ip_incremental_checksum (0, icmp0, len0));
     }
@@ -764,8 +767,9 @@ icmp4_init (vlib_main_t * vm)
   foreach_icmp4_code;
 #undef _
 
-  memset (cm->ip4_input_next_index_by_type,
-         ICMP_INPUT_NEXT_ERROR, sizeof (cm->ip4_input_next_index_by_type));
+  clib_memset (cm->ip4_input_next_index_by_type,
+              ICMP_INPUT_NEXT_ERROR,
+              sizeof (cm->ip4_input_next_index_by_type));
 
   ip4_icmp_register_type (vm, ICMP4_echo_request,
                          ip4_icmp_echo_request_node.index);