VPP-117: Add trace to ip4 and ip6 lookup nodes

The absence of trace in ip lookup nodes is misleading to many people.
This patch adds ip lookup tracing and therefore contribute to
worldwide happiness.

In addition, this patch makes sure sw_if_index[VLIB_TX] is
considered when tracing the fib_index value. In ip4/6-rewrite,
the value corresponds to the tx interface index. The formatting
function is therefore modified to take that case into account.

Change-Id: I5915f0446a15c45e391eedfdfcedd9057aa6a237
Signed-off-by: Pierre Pfister <ppfister@cisco.com>

1 files changed, 42 insertions, 11 deletions

diff --git a/vnet/vnet/ip/ip6_forward.c b/vnet/vnet/ip/ip6_forward.c
index a136da3e142..27905cd2d0c 100644
--- a/vnet/vnet/ip/ip6_forward.c
+++ b/vnet/vnet/ip/ip6_forward.c
@@ -653,6 +653,12 @@ void ip6_delete_matching_routes (ip6_main_t * im,
   ip6_maybe_remap_adjacencies (im, table_index_or_table_id, flags);
 }
 
+void
+ip6_forward_next_trace (vlib_main_t * vm,
+                        vlib_node_runtime_t * node,
+                        vlib_frame_t * frame,
+                        vlib_rx_or_tx_t which_adj_index);
+
 always_inline uword
 ip6_lookup_inline (vlib_main_t * vm,
 		   vlib_node_runtime_t * node,
@@ -670,6 +676,9 @@ ip6_lookup_inline (vlib_main_t * vm,
   n_left_from = frame->n_vectors;
   next = node->cached_next_index;
 
+  if (node->flags & VLIB_NODE_FLAG_TRACE)
+    ip6_forward_next_trace(vm, node, frame, VLIB_TX);
+
   while (n_left_from > 0)
     {
       vlib_get_next_frame (vm, node, next,
@@ -1251,11 +1260,15 @@ ip6_lookup (vlib_main_t * vm,
   return ip6_lookup_inline (vm, node, frame, /* is_indirect */ 0);
 }
 
+static u8 * format_ip6_forward_next_trace (u8 * s, va_list * args);
+
 VLIB_REGISTER_NODE (ip6_lookup_node) = {
   .function = ip6_lookup,
   .name = "ip6-lookup",
   .vector_size = sizeof (u32),
 
+  .format_trace = format_ip6_forward_next_trace,
+
   .n_next_nodes = IP_LOOKUP_N_NEXT,
   .next_nodes = IP6_LOOKUP_NEXT_NODES,
 };
@@ -1274,6 +1287,8 @@ VLIB_REGISTER_NODE (ip6_indirect_node) = {
   .name = "ip6-indirect",
   .vector_size = sizeof (u32),
 
+  .format_trace = format_ip6_forward_next_trace,
+
   .n_next_nodes = IP_LOOKUP_N_NEXT,
   .next_nodes = IP6_LOOKUP_NEXT_NODES,
 };
@@ -1290,16 +1305,23 @@ typedef struct {
 
 static u8 * format_ip6_forward_next_trace (u8 * s, va_list * args)
 {
-  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
-  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  vlib_main_t * vm = va_arg (*args, vlib_main_t *);
+  vlib_node_t * node = va_arg (*args, vlib_node_t *);
   ip6_forward_next_trace_t * t = va_arg (*args, ip6_forward_next_trace_t *);
   vnet_main_t * vnm = vnet_get_main();
   ip6_main_t * im = &ip6_main;
   ip_adjacency_t * adj;
   uword indent = format_get_indent (s);
 
+  char *fib_or_interface = "fib";
+  if ((node == vlib_get_node(vm, ip6_rewrite_node.index)) ||
+      (node == vlib_get_node(vm, ip6_rewrite_local_node.index))) {
+    fib_or_interface = "tx_sw_if_index";
+  }
+
   adj = ip_get_adjacency (&im->lookup_main, t->adj_index);
-  s = format (s, "fib %d adj-idx %d : %U flow hash: 0x%08x",
+  s = format (s, "%s %d adj-idx %d : %U flow hash: 0x%08x",
+              fib_or_interface,
 	      t->fib_index, t->adj_index, format_ip_adjacency,
 	      vnm, &im->lookup_main, t->adj_index, t->flow_hash);
   switch (adj->lookup_next_index)
@@ -1331,7 +1353,7 @@ ip6_forward_next_trace (vlib_main_t * vm,
 
   n_left = frame->n_vectors;
   from = vlib_frame_vector_args (frame);
-  
+
   while (n_left >= 4)
     {
       u32 bi0, bi1;
@@ -1353,8 +1375,11 @@ ip6_forward_next_trace (vlib_main_t * vm,
 	  t0 = vlib_add_trace (vm, node, b0, sizeof (t0[0]));
 	  t0->adj_index = vnet_buffer (b0)->ip.adj_index[which_adj_index];
           t0->flow_hash = vnet_buffer (b0)->ip.flow_hash;
-	  t0->fib_index = vec_elt (im->fib_index_by_sw_if_index, 
-                             vnet_buffer(b0)->sw_if_index[VLIB_RX]);
+          t0->fib_index = (vnet_buffer(b0)->sw_if_index[VLIB_TX] != (u32)~0) ?
+              vnet_buffer(b0)->sw_if_index[VLIB_TX] :
+              vec_elt (im->fib_index_by_sw_if_index,
+                       vnet_buffer(b0)->sw_if_index[VLIB_RX]);
+
 	  clib_memcpy (t0->packet_data,
 		  vlib_buffer_get_current (b0),
 		  sizeof (t0->packet_data));
@@ -1364,8 +1389,11 @@ ip6_forward_next_trace (vlib_main_t * vm,
 	  t1 = vlib_add_trace (vm, node, b1, sizeof (t1[0]));
 	  t1->adj_index = vnet_buffer (b1)->ip.adj_index[which_adj_index];
           t1->flow_hash = vnet_buffer (b1)->ip.flow_hash;
-	  t1->fib_index = vec_elt (im->fib_index_by_sw_if_index, 
-                             vnet_buffer(b1)->sw_if_index[VLIB_RX]);
+          t1->fib_index = (vnet_buffer(b1)->sw_if_index[VLIB_TX] != (u32)~0) ?
+              vnet_buffer(b1)->sw_if_index[VLIB_TX] :
+              vec_elt (im->fib_index_by_sw_if_index,
+                       vnet_buffer(b1)->sw_if_index[VLIB_RX]);
+
 	  clib_memcpy (t1->packet_data,
 		  vlib_buffer_get_current (b1),
 		  sizeof (t1->packet_data));
@@ -1389,8 +1417,11 @@ ip6_forward_next_trace (vlib_main_t * vm,
 	  t0 = vlib_add_trace (vm, node, b0, sizeof (t0[0]));
 	  t0->adj_index = vnet_buffer (b0)->ip.adj_index[which_adj_index];
           t0->flow_hash = vnet_buffer (b0)->ip.flow_hash;
-	  t0->fib_index = vec_elt (im->fib_index_by_sw_if_index, 
-                             vnet_buffer(b0)->sw_if_index[VLIB_RX]);
+          t0->fib_index = (vnet_buffer(b0)->sw_if_index[VLIB_TX] != (u32)~0) ?
+              vnet_buffer(b0)->sw_if_index[VLIB_TX] :
+              vec_elt (im->fib_index_by_sw_if_index,
+                       vnet_buffer(b0)->sw_if_index[VLIB_RX]);
+
 	  clib_memcpy (t0->packet_data,
 		  vlib_buffer_get_current (b0),
 		  sizeof (t0->packet_data));
@@ -2424,7 +2455,7 @@ VLIB_REGISTER_NODE (ip6_rewrite_node) = {
   },
 };
 
-VLIB_REGISTER_NODE (ip6_rewrite_local_node,static) = {
+VLIB_REGISTER_NODE (ip6_rewrite_local_node) = {
   .function = ip6_rewrite_local,
   .name = "ip6-rewrite-local",
   .vector_size = sizeof (u32),