classify: add pcap/trace classfier mgmt API calls

Add lookup/get/set API calls to manage both PCAP and Trace
filtering Classifier tables.

The "lookup" call may be used to identify a Classifier table
within a chain of tables taht matches a particular mask vector.
For efficiency, this call should be used to determine to which
table a match vector should be added.

The "get" calls return the first table within a chain (either
a PCAP or the Trace) set of tables.  The "set" call may be
used to add a new table to one such chain.  If the "sort_masks"
flag is set, the tables within the chain are ordered such that
the most-specific mask is first, and the least-specific mask
is last.  A call that "sets" a chain to ~0 will delete and free
all the tables with a chain.

The PCAP filters are per-interface, with "local0", (that is,
sw_if_index == 0) holding the system-wide PCAP filter.

The Classifier used a reference-counted "set" for each PCAP
or trace filter that it stored.  The ref counts were not used,
and the vector of tables was only used temporarily to establish
a sorted order for tables based on masks.  None of that
complexity was actually warranted, and where it was used,
the same could be achieved more simply.

Type: refactor

Signed-off-by: Jon Loeliger <jdl@netgate.com>
Change-Id: Icc56116cca91b91c631ca0628e814fb53f3677d2

1 files changed, 8 insertions, 7 deletions

diff --git a/src/vlib/trace.c b/src/vlib/trace.c
index 152744432c5..156378af8e3 100644
--- a/src/vlib/trace.c
+++ b/src/vlib/trace.c
@@ -39,6 +39,7 @@
 
 #include <vlib/vlib.h>
 #include <vlib/threads.h>
+#include <vnet/classify/vnet_classify.h>
 
 u8 *vnet_trace_placeholder;
 
@@ -110,7 +111,7 @@ vlib_trace_frame_buffers_only (vlib_main_t * vm,
 }
 
 /* Free up all trace buffer memory. */
-always_inline void
+void
 clear_trace_buffer (void)
 {
   int i;
@@ -416,6 +417,8 @@ trace_update_capture_options (u32 add, u32 node_index, u32 filter, u8 verbose)
       tm->trace_enable = 1;
     }));
   /* *INDENT-ON* */
+
+  vlib_enable_disable_pkt_trace_filter (! !filter);
 }
 
 static clib_error_t *
@@ -464,13 +467,11 @@ cli_add_trace_buffer (vlib_main_t * vm,
       goto done;
     }
 
-  if (filter)
+  u32 filter_table = classify_get_trace_chain ();
+  if (filter && filter_table == ~0)
     {
-      if (vlib_enable_disable_pkt_trace_filter (1 /* enable */ ))
-	{
-	  error = clib_error_create ("No packet trace filter configured...");
-	  goto done;
-	}
+      error = clib_error_create ("No packet trace filter configured...");
+      goto done;
     }
 
   trace_update_capture_options (add, node_index, filter, verbose);