ip: fix possible missing trace indexes

Add safeguards when tracing packets to avoid cases where clear trace
was issue while buffers were held in reassembly.

Type: fix
Change-Id: I1bdd1e629e8bc08ce63913fd3c4b2327e47dec04
Signed-off-by: Klement Sekera <ksekera@cisco.com>

4 files changed, 28 insertions, 0 deletions

diff --git a/src/vnet/ip/reass/ip4_full_reass.c b/src/vnet/ip/reass/ip4_full_reass.c
index ecd2fb0e5c6..69d418e9d51 100644
--- a/src/vnet/ip/reass/ip4_full_reass.c
+++ b/src/vnet/ip/reass/ip4_full_reass.c
@@ -342,6 +342,13 @@ ip4_full_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 {
   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
+  if (pool_is_free_index
+      (vm->trace_main.trace_buffer_pool, vlib_buffer_get_trace_index (b)))
+    {
+      // this buffer's trace is gone
+      b->flags &= ~VLIB_BUFFER_IS_TRACED;
+      return;
+    }
   bool is_after_handoff = false;
   if (vlib_buffer_get_trace_thread (b) != vm->thread_index)
     {
diff --git a/src/vnet/ip/reass/ip4_sv_reass.c b/src/vnet/ip/reass/ip4_sv_reass.c
index c74f8e5b661..e9582638047 100644
--- a/src/vnet/ip/reass/ip4_sv_reass.c
+++ b/src/vnet/ip/reass/ip4_sv_reass.c
@@ -235,6 +235,13 @@ ip4_sv_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 			u32 ip_proto, u16 l4_src_port, u16 l4_dst_port)
 {
   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
+  if (pool_is_free_index
+      (vm->trace_main.trace_buffer_pool, vlib_buffer_get_trace_index (b)))
+    {
+      // this buffer's trace is gone
+      b->flags &= ~VLIB_BUFFER_IS_TRACED;
+      return;
+    }
   ip4_sv_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
   if (reass)
     {
diff --git a/src/vnet/ip/reass/ip6_full_reass.c b/src/vnet/ip/reass/ip6_full_reass.c
index 80a31e83215..fe5c6376882 100644
--- a/src/vnet/ip/reass/ip6_full_reass.c
+++ b/src/vnet/ip/reass/ip6_full_reass.c
@@ -319,6 +319,13 @@ ip6_full_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
   bool is_after_handoff = false;
+  if (pool_is_free_index
+      (vm->trace_main.trace_buffer_pool, vlib_buffer_get_trace_index (b)))
+    {
+      // this buffer's trace is gone
+      b->flags &= ~VLIB_BUFFER_IS_TRACED;
+      return;
+    }
   if (vlib_buffer_get_trace_thread (b) != vm->thread_index)
     {
       is_after_handoff = true;
diff --git a/src/vnet/ip/reass/ip6_sv_reass.c b/src/vnet/ip/reass/ip6_sv_reass.c
index c5c84e5f93a..8bc1fd85449 100644
--- a/src/vnet/ip/reass/ip6_sv_reass.c
+++ b/src/vnet/ip/reass/ip6_sv_reass.c
@@ -228,6 +228,13 @@ ip6_sv_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 			u32 ip_proto, u16 l4_src_port, u16 l4_dst_port)
 {
   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
+  if (pool_is_free_index
+      (vm->trace_main.trace_buffer_pool, vlib_buffer_get_trace_index (b)))
+    {
+      // this buffer's trace is gone
+      b->flags &= ~VLIB_BUFFER_IS_TRACED;
+      return;
+    }
   ip6_sv_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
   if (reass)
     {