vlib: only dump 1st buffer in chain by default

Several nodes include buffers in their traces, but only the 1st. When
formatting the trace we must not try to iterate through all chained
buffers.
Default to display only the 1st buffer.

Type: fix

Change-Id: Ib3c668bbf4ab70ae68eba2ac402c7b7329825b70
Signed-off-by: Benoît Ganne <bganne@cisco.com>

5 files changed, 17 insertions, 6 deletions

diff --git a/src/plugins/vmxnet3/format.c b/src/plugins/vmxnet3/format.c
index 8e39b5faf36..d463feb3bec 100644
--- a/src/plugins/vmxnet3/format.c
+++ b/src/plugins/vmxnet3/format.c
@@ -164,7 +164,7 @@ format_vmxnet3_input_trace (u8 * s, va_list * args)
   s = format (s, "vmxnet3: %v (%d) next-node %U",
 	      hi->name, t->hw_if_index, format_vlib_next_node_name, vm,
 	      node->index, t->next_index);
-  s = format (s, "\n  buffer %U", format_vlib_buffer, &t->buffer);
+  s = format (s, "\n  buffer %U", format_vnet_buffer, &t->buffer);
 
   return s;
 }
diff --git a/src/vlib/buffer.c b/src/vlib/buffer.c
index 9838e23e0d5..43b1dd63761 100644
--- a/src/vlib/buffer.c
+++ b/src/vlib/buffer.c
@@ -92,7 +92,7 @@ vlib_buffer_length_in_chain_slow_path (vlib_main_t * vm,
 }
 
 u8 *
-format_vlib_buffer (u8 * s, va_list * args)
+format_vlib_buffer_no_chain (u8 * s, va_list * args)
 {
   vlib_buffer_t *b = va_arg (*args, vlib_buffer_t *);
   u32 indent = format_get_indent (s);
@@ -118,9 +118,20 @@ format_vlib_buffer (u8 * s, va_list * args)
     s = format (s, "\n%U%v", format_white_space, indent, a);
   vec_free (a);
 
+  return s;
+}
+
+u8 *
+format_vlib_buffer (u8 * s, va_list * args)
+{
+  vlib_main_t *vm = vlib_get_main ();
+  vlib_buffer_t *b = va_arg (*args, vlib_buffer_t *);
+  u32 indent = format_get_indent (s);
+
+  s = format (s, "%U", format_vlib_buffer_no_chain, b);
+
   while (b->flags & VLIB_BUFFER_NEXT_PRESENT)
     {
-      vlib_main_t *vm = vlib_get_main ();
       u32 next_buffer = b->next_buffer;
       b = vlib_get_buffer (vm, next_buffer);
 
diff --git a/src/vlib/buffer.h b/src/vlib/buffer.h
index c2ca8214162..8ca198de68e 100644
--- a/src/vlib/buffer.h
+++ b/src/vlib/buffer.h
@@ -72,7 +72,7 @@
  */
 #define foreach_vlib_buffer_flag \
   _( 0, IS_TRACED, 0)					\
-  _( 1, NEXT_PRESENT, 0)				\
+  _( 1, NEXT_PRESENT, "next-present")			\
   _( 2, TOTAL_LENGTH_VALID, 0)				\
   _( 3, EXT_HDR_VALID, "ext-hdr-valid")
 
diff --git a/src/vlib/buffer_funcs.h b/src/vlib/buffer_funcs.h
index 2ba9f1cb894..cfb48344648 100644
--- a/src/vlib/buffer_funcs.h
+++ b/src/vlib/buffer_funcs.h
@@ -1332,7 +1332,7 @@ vlib_buffer_chain_append_data_with_alloc (vlib_main_t * vm,
 void vlib_buffer_chain_validate (vlib_main_t * vm, vlib_buffer_t * first);
 
 format_function_t format_vlib_buffer, format_vlib_buffer_and_data,
-  format_vlib_buffer_contents;
+  format_vlib_buffer_contents, format_vlib_buffer_no_chain;
 
 typedef struct
 {
diff --git a/src/vnet/buffer.c b/src/vnet/buffer.c
index cf61780cb74..3cb6b948d2b 100644
--- a/src/vnet/buffer.c
+++ b/src/vnet/buffer.c
@@ -45,7 +45,7 @@ format_vnet_buffer (u8 * s, va_list * args)
   if (b->flags & VNET_BUFFER_F_LOOP_COUNTER_VALID)
     a = format (a, "loop-counter %d ", vnet_buffer2 (b)->loop_counter);
 
-  s = format (s, "%U", format_vlib_buffer, b);
+  s = format (s, "%U", format_vlib_buffer_no_chain, b);
   if (a)
     s = format (s, "\n%U%v", format_white_space, indent, a);
   vec_free (a);