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>

4 files changed, 84 insertions, 19 deletions

diff --git a/vnet/vnet/ip/ip4.h b/vnet/vnet/ip/ip4.h
index b14541eb2ef..59ef685bc57 100644
--- a/vnet/vnet/ip/ip4.h
+++ b/vnet/vnet/ip/ip4.h
@@ -173,6 +173,7 @@ extern ip4_main_t ip4_main;
 extern vlib_node_registration_t ip4_input_node;
 extern vlib_node_registration_t ip4_lookup_node;
 extern vlib_node_registration_t ip4_rewrite_node;
+extern vlib_node_registration_t ip4_rewrite_local_node;
 extern vlib_node_registration_t ip4_arp_node;
 
 u32 ip4_fib_lookup_with_table (ip4_main_t * im, u32 fib_index, ip4_address_t * dst,
diff --git a/vnet/vnet/ip/ip4_forward.c b/vnet/vnet/ip/ip4_forward.c
index e9e5232f9e0..6dbc6d21afc 100644
--- a/vnet/vnet/ip/ip4_forward.c
+++ b/vnet/vnet/ip/ip4_forward.c
@@ -632,6 +632,12 @@ void ip4_delete_matching_routes (ip4_main_t * im,
   ip4_maybe_remap_adjacencies (im, table_index_or_table_id, flags);
 }
 
+void
+ip4_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
 ip4_lookup_inline (vlib_main_t * vm,
 		   vlib_node_runtime_t * node,
@@ -650,6 +656,9 @@ ip4_lookup_inline (vlib_main_t * vm,
   n_left_from = frame->n_vectors;
   next = node->cached_next_index;
 
+  if (node->flags & VLIB_NODE_FLAG_TRACE)
+      ip4_forward_next_trace(vm, node, frame, VLIB_TX);
+
   while (n_left_from > 0)
     {
       vlib_get_next_frame (vm, node, next,
@@ -1344,12 +1353,15 @@ ip4_sw_interface_add_del (vnet_main_t * vnm,
 
 VNET_SW_INTERFACE_ADD_DEL_FUNCTION (ip4_sw_interface_add_del);
 
+static u8 * format_ip4_forward_next_trace (u8 * s, va_list * args);
 
 VLIB_REGISTER_NODE (ip4_lookup_node) = {
   .function = ip4_lookup,
   .name = "ip4-lookup",
   .vector_size = sizeof (u32),
 
+  .format_trace = format_ip4_forward_next_trace,
+
   .n_next_nodes = IP_LOOKUP_N_NEXT,
   .next_nodes = IP4_LOOKUP_NEXT_NODES,
 };
@@ -1371,6 +1383,8 @@ VLIB_REGISTER_NODE (ip4_indirect_node) = {
   .name = "ip4-indirect",
   .vector_size = sizeof (u32),
 
+  .format_trace = format_ip4_forward_next_trace,
+
   .n_next_nodes = IP_LOOKUP_N_NEXT,
   .next_nodes = IP4_LOOKUP_NEXT_NODES,
 };
@@ -1459,9 +1473,15 @@ static u8 * format_ip4_forward_next_trace (u8 * s, va_list * args)
   ip4_main_t * im = &ip4_main;
   ip_adjacency_t * adj;
   uword indent = format_get_indent (s);
+  char *fib_or_interface = "fib";
+  if ((node == vlib_get_node(vm, ip4_rewrite_node.index)) ||
+      (node == vlib_get_node(vm, ip4_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)
@@ -1515,8 +1535,11 @@ ip4_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));
@@ -1526,8 +1549,10 @@ ip4_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));
@@ -1551,8 +1576,10 @@ ip4_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));
@@ -2761,7 +2788,7 @@ VLIB_REGISTER_NODE (ip4_rewrite_node) = {
 
 VLIB_NODE_FUNCTION_MULTIARCH (ip4_rewrite_node, ip4_rewrite_transit)
 
-VLIB_REGISTER_NODE (ip4_rewrite_local_node,static) = {
+VLIB_REGISTER_NODE (ip4_rewrite_local_node) = {
   .function = ip4_rewrite_local,
   .name = "ip4-rewrite-local",
   .vector_size = sizeof (u32),
@@ -2844,6 +2871,9 @@ ip4_lookup_multicast (vlib_main_t * vm,
   n_left_from = frame->n_vectors;
   next = node->cached_next_index;
 
+  if (node->flags & VLIB_NODE_FLAG_TRACE)
+    ip4_forward_next_trace(vm, node, frame, VLIB_TX);
+
   while (n_left_from > 0)
     {
       vlib_get_next_frame (vm, node, next,
@@ -3048,6 +3078,8 @@ VLIB_REGISTER_NODE (ip4_lookup_multicast_node,static) = {
   .name = "ip4-lookup-multicast",
   .vector_size = sizeof (u32),
 
+  .format_trace = format_ip4_forward_next_trace,
+
   .n_next_nodes = IP_LOOKUP_N_NEXT,
   .next_nodes = IP4_LOOKUP_NEXT_NODES,
 };
diff --git a/vnet/vnet/ip/ip6.h b/vnet/vnet/ip/ip6.h
index b0384d3abae..69e69f2c9cd 100644
--- a/vnet/vnet/ip/ip6.h
+++ b/vnet/vnet/ip/ip6.h
@@ -188,6 +188,7 @@ extern ip6_main_t ip6_main;
 /* Global ip6 input node.  Errors get attached to ip6 input node. */
 extern vlib_node_registration_t ip6_input_node;
 extern vlib_node_registration_t ip6_rewrite_node;
+extern vlib_node_registration_t ip6_rewrite_local_node;
 extern vlib_node_registration_t ip6_discover_neighbor_node;
 
 extern vlib_node_registration_t ip6_icmp_neighbor_discovery_event_node;
diff --git a/vnet/vnet/ip/ip6_forward.c b/vnet/vnet/ip/ip6_forward.c
index 7c8922185b4..43d83507cce 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,
 };
@@ -1276,6 +1289,8 @@ 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,
 };
@@ -1294,16 +1309,23 @@ 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)
@@ -1335,7 +1357,7 @@ 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;
@@ -1357,8 +1379,11 @@ 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));
@@ -1368,8 +1393,11 @@ 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));
@@ -1393,8 +1421,11 @@ 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));
@@ -2438,7 +2469,7 @@ VLIB_REGISTER_NODE (ip6_rewrite_node) = {
 
 VLIB_NODE_FUNCTION_MULTIARCH (ip6_rewrite_node, ip6_rewrite_transit)
 
-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),