vlib: fix trace number accounting

When using classifier to filter traces, not all packets will be traced.
In that case, we should only count traced packets.

Type: fix

Change-Id: I87d1e217b580ebff8c6ade7860eb43950420ae78
Signed-off-by: Benoît Ganne <bganne@cisco.com>

7 files changed, 94 insertions, 80 deletions

diff --git a/src/plugins/af_xdp/input.c b/src/plugins/af_xdp/input.c
index c164c2576b7..2cf121fb69d 100644
--- a/src/plugins/af_xdp/input.c
+++ b/src/plugins/af_xdp/input.c
@@ -46,23 +46,23 @@ af_xdp_device_input_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 			   u32 n_left, const u32 * bi, u32 next_index,
 			   u32 hw_if_index)
 {
-  u32 n_trace;
+  u32 n_trace = vlib_get_trace_count (vm, node);
 
-  if (PREDICT_TRUE (0 == (n_trace = vlib_get_trace_count (vm, node))))
+  if (PREDICT_TRUE (0 == n_trace))
     return;
 
   while (n_trace && n_left)
     {
-      vlib_buffer_t *b;
-      af_xdp_input_trace_t *tr;
-      b = vlib_get_buffer (vm, bi[0]);
-      vlib_trace_buffer (vm, node, next_index, b,
-			 /* follow_chain */ 0);
-      tr = vlib_add_trace (vm, node, b, sizeof (*tr));
-      tr->next_index = next_index;
-      tr->hw_if_index = hw_if_index;
-
-      n_trace--;
+      vlib_buffer_t *b = vlib_get_buffer (vm, bi[0]);
+      if (PREDICT_TRUE
+	  (vlib_trace_buffer (vm, node, next_index, b, /* follow_chain */ 0)))
+	{
+	  af_xdp_input_trace_t *tr =
+	    vlib_add_trace (vm, node, b, sizeof (*tr));
+	  tr->next_index = next_index;
+	  tr->hw_if_index = hw_if_index;
+	  n_trace--;
+	}
       n_left--;
       bi++;
     }
diff --git a/src/plugins/avf/input.c b/src/plugins/avf/input.c
index 9d677ab96d5..4e4f116304d 100644
--- a/src/plugins/avf/input.c
+++ b/src/plugins/avf/input.c
@@ -383,20 +383,24 @@ no_more_desc:
 
       while (n_trace && n_left)
 	{
-	  vlib_buffer_t *b;
-	  avf_input_trace_t *tr;
-	  b = vlib_get_buffer (vm, bi[0]);
-	  vlib_trace_buffer (vm, node, next_index, b, /* follow_chain */ 0);
-	  tr = vlib_add_trace (vm, node, b, sizeof (*tr));
-	  tr->next_index = next_index;
-	  tr->qid = qid;
-	  tr->hw_if_index = ad->hw_if_index;
-	  tr->qw1s[0] = ptd->qw1s[i];
-	  for (j = 1; j < AVF_RX_MAX_DESC_IN_CHAIN; j++)
-	    tr->qw1s[j] = ptd->tails[i].qw1s[j - 1];
+	  vlib_buffer_t *b = vlib_get_buffer (vm, bi[0]);
+	  if (PREDICT_TRUE
+	      (vlib_trace_buffer
+	       (vm, node, next_index, b, /* follow_chain */ 0)))
+	    {
+	      avf_input_trace_t *tr =
+		vlib_add_trace (vm, node, b, sizeof (*tr));
+	      tr->next_index = next_index;
+	      tr->qid = qid;
+	      tr->hw_if_index = ad->hw_if_index;
+	      tr->qw1s[0] = ptd->qw1s[i];
+	      for (j = 1; j < AVF_RX_MAX_DESC_IN_CHAIN; j++)
+		tr->qw1s[j] = ptd->tails[i].qw1s[j - 1];
+
+	      n_trace--;
+	    }
 
 	  /* next */
-	  n_trace--;
 	  n_left--;
 	  bi++;
 	  i++;
diff --git a/src/plugins/dpdk/device/node.c b/src/plugins/dpdk/device/node.c
index 256c399ea32..e7d836fe0f8 100644
--- a/src/plugins/dpdk/device/node.c
+++ b/src/plugins/dpdk/device/node.c
@@ -417,21 +417,28 @@ dpdk_device_input (vlib_main_t * vm, dpdk_main_t * dm, dpdk_device_t * xd,
 	  b0 = vlib_get_buffer (vm, buffers[0]);
 	  if (single_next == 0)
 	    next_index = next[0];
-	  vlib_trace_buffer (vm, node, next_index, b0, /* follow_chain */ 0);
-
-	  dpdk_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof t0[0]);
-	  t0->queue_index = queue_id;
-	  t0->device_index = xd->device_index;
-	  t0->buffer_index = vlib_get_buffer_index (vm, b0);
-
-	  clib_memcpy_fast (&t0->mb, mb[0], sizeof t0->mb);
-	  clib_memcpy_fast (&t0->buffer, b0,
-			    sizeof b0[0] - sizeof b0->pre_data);
-	  clib_memcpy_fast (t0->buffer.pre_data, b0->data,
-			    sizeof t0->buffer.pre_data);
-	  clib_memcpy_fast (&t0->data, mb[0]->buf_addr + mb[0]->data_off,
-			    sizeof t0->data);
-	  n_trace--;
+
+	  if (PREDICT_TRUE
+	      (vlib_trace_buffer
+	       (vm, node, next_index, b0, /* follow_chain */ 0)))
+	    {
+
+	      dpdk_rx_trace_t *t0 =
+		vlib_add_trace (vm, node, b0, sizeof t0[0]);
+	      t0->queue_index = queue_id;
+	      t0->device_index = xd->device_index;
+	      t0->buffer_index = vlib_get_buffer_index (vm, b0);
+
+	      clib_memcpy_fast (&t0->mb, mb[0], sizeof t0->mb);
+	      clib_memcpy_fast (&t0->buffer, b0,
+				sizeof b0[0] - sizeof b0->pre_data);
+	      clib_memcpy_fast (t0->buffer.pre_data, b0->data,
+				sizeof t0->buffer.pre_data);
+	      clib_memcpy_fast (&t0->data, mb[0]->buf_addr + mb[0]->data_off,
+				sizeof t0->data);
+	      n_trace--;
+	    }
+
 	  n_left--;
 	  buffers++;
 	  mb++;
diff --git a/src/plugins/dpdk/ipsec/crypto_node.c b/src/plugins/dpdk/ipsec/crypto_node.c
index 76e57a3228a..893848c05b6 100644
--- a/src/plugins/dpdk/ipsec/crypto_node.c
+++ b/src/plugins/dpdk/ipsec/crypto_node.c
@@ -106,14 +106,16 @@ dpdk_crypto_input_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 
 	  b0 = vlib_get_buffer (vm, bi);
 
-	  vlib_trace_buffer (vm, node, next, b0, /* follow_chain */ 0);
+	  if (PREDICT_TRUE
+	      (vlib_trace_buffer (vm, node, next, b0, /* follow_chain */ 0)))
+	    {
+	      dpdk_crypto_input_trace_t *tr =
+		vlib_add_trace (vm, node, b0, sizeof (*tr));
+	      tr->dev_id = dev_id;
+	      tr->next_index = next;
+	      n_trace--;
+	    }
 
-	  dpdk_crypto_input_trace_t *tr =
-	    vlib_add_trace (vm, node, b0, sizeof (*tr));
-	  tr->dev_id = dev_id;
-	  tr->next_index = next;
-
-	  n_trace--;
 	  n_left--;
 	  nexts++;
 	  bis++;
diff --git a/src/plugins/memif/node.c b/src/plugins/memif/node.c
index 82a7cbc142c..506d88af76d 100644
--- a/src/plugins/memif/node.c
+++ b/src/plugins/memif/node.c
@@ -92,10 +92,10 @@ memif_trace_buffer (vlib_main_t * vm, vlib_node_runtime_t * node,
 {
   VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b);
 
-  if (PREDICT_TRUE (b != 0))
+  if (PREDICT_TRUE
+      (b != 0 && vlib_trace_buffer (vm, node, next, b, /* follow_chain */ 0)))
     {
       memif_input_trace_t *tr;
-      vlib_trace_buffer (vm, node, next, b, /* follow_chain */ 0);
       vlib_set_trace_count (vm, node, --(*n_tracep));
       tr = vlib_add_trace (vm, node, b, sizeof (*tr));
       tr->next_index = next;
@@ -484,14 +484,17 @@ memif_device_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 	  if (mode != MEMIF_INTERFACE_MODE_ETHERNET)
 	    ni = next[0];
 	  b = vlib_get_buffer (vm, bi[0]);
-	  vlib_trace_buffer (vm, node, ni, b, /* follow_chain */ 0);
-	  tr = vlib_add_trace (vm, node, b, sizeof (*tr));
-	  tr->next_index = ni;
-	  tr->hw_if_index = mif->hw_if_index;
-	  tr->ring = qid;
+	  if (PREDICT_TRUE
+	      (vlib_trace_buffer (vm, node, ni, b, /* follow_chain */ 0)))
+	    {
+	      tr = vlib_add_trace (vm, node, b, sizeof (*tr));
+	      tr->next_index = ni;
+	      tr->hw_if_index = mif->hw_if_index;
+	      tr->ring = qid;
+	      n_trace--;
+	    }
 
 	  /* next */
-	  n_trace--;
 	  n_left--;
 	  bi++;
 	  next++;
diff --git a/src/plugins/rdma/input.c b/src/plugins/rdma/input.c
index 1d267ad6cc0..52e921dd172 100644
--- a/src/plugins/rdma/input.c
+++ b/src/plugins/rdma/input.c
@@ -225,30 +225,27 @@ rdma_device_input_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 			 const u32 * bi, u32 next_index, u16 * cqe_flags,
 			 int is_mlx5dv)
 {
-  u32 n_trace, i;
+  u32 n_trace = vlib_get_trace_count (vm, node);
 
-  if (PREDICT_TRUE (0 == (n_trace = vlib_get_trace_count (vm, node))))
+  if (PREDICT_TRUE (0 == n_trace))
     return;
 
-  i = 0;
   while (n_trace && n_left)
     {
-      vlib_buffer_t *b;
-      rdma_input_trace_t *tr;
-      b = vlib_get_buffer (vm, bi[0]);
-      vlib_trace_buffer (vm, node, next_index, b,
-			 /* follow_chain */ 0);
-      tr = vlib_add_trace (vm, node, b, sizeof (*tr));
-      tr->next_index = next_index;
-      tr->hw_if_index = rd->hw_if_index;
-      tr->cqe_flags = is_mlx5dv ? clib_net_to_host_u16 (cqe_flags[0]) : 0;
-
+      vlib_buffer_t *b = vlib_get_buffer (vm, bi[0]);
+      if (PREDICT_TRUE
+	  (vlib_trace_buffer (vm, node, next_index, b, /* follow_chain */ 0)))
+	{
+	  rdma_input_trace_t *tr = vlib_add_trace (vm, node, b, sizeof (*tr));
+	  tr->next_index = next_index;
+	  tr->hw_if_index = rd->hw_if_index;
+	  tr->cqe_flags = is_mlx5dv ? clib_net_to_host_u16 (cqe_flags[0]) : 0;
+	  n_trace--;
+	}
       /* next */
-      n_trace--;
       n_left--;
       cqe_flags++;
       bi++;
-      i++;
     }
   vlib_set_trace_count (vm, node, n_trace);
 }
diff --git a/src/plugins/vmxnet3/input.c b/src/plugins/vmxnet3/input.c
index f182409ac59..bed4c1e3292 100644
--- a/src/plugins/vmxnet3/input.c
+++ b/src/plugins/vmxnet3/input.c
@@ -418,17 +418,18 @@ vmxnet3_device_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
       next = nexts;
       while (n_trace && n_left)
 	{
-	  vlib_buffer_t *b;
-	  vmxnet3_input_trace_t *tr;
-
-	  b = vlib_get_buffer (vm, bi[0]);
-	  vlib_trace_buffer (vm, node, next[0], b, /* follow_chain */ 0);
-	  tr = vlib_add_trace (vm, node, b, sizeof (*tr));
-	  tr->next_index = next[0];
-	  tr->hw_if_index = vd->hw_if_index;
-	  tr->buffer = *b;
-
-	  n_trace--;
+	  vlib_buffer_t *b = vlib_get_buffer (vm, bi[0]);
+	  if (PREDICT_TRUE
+	      (vlib_trace_buffer
+	       (vm, node, next[0], b, /* follow_chain */ 0)))
+	    {
+	      vmxnet3_input_trace_t *tr =
+		vlib_add_trace (vm, node, b, sizeof (*tr));
+	      tr->next_index = next[0];
+	      tr->hw_if_index = vd->hw_if_index;
+	      tr->buffer = *b;
+	      n_trace--;
+	    }
 	  n_left--;
 	  bi++;
 	  next++;