classify: per-interface rx/tx pcap capture filters

Finish the feature, and fix a couple of doc bugs

Type: feature

Signed-off-by: Dave Barach <dave@barachs.net>
Change-Id: I2c62745fda137776204c8fc4fca0e7e288051573
diff --git a/src/vnet/interface_output.c b/src/vnet/interface_output.c
index 5e702e3..49775d5 100644
--- a/src/vnet/interface_output.c
+++ b/src/vnet/interface_output.c
@@ -503,7 +503,16 @@
 	sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_TX];
 
       if (pp->pcap_sw_if_index == 0 || pp->pcap_sw_if_index == sw_if_index)
-	pcap_add_buffer (&pp->pcap_main, vm, bi0, pp->max_bytes_per_pkt);
+	{
+	  vnet_main_t *vnm = vnet_get_main ();
+	  vnet_hw_interface_t *hi =
+	    vnet_get_sup_hw_interface (vnm, sw_if_index);
+	  /* Capture pkt if not filtered, or if filter hits */
+	  if (hi->trace_classify_table_index == ~0 ||
+	      vnet_is_packet_traced_inline
+	      (b0, hi->trace_classify_table_index, 0 /* full classify */ ))
+	    pcap_add_buffer (&pp->pcap_main, vm, bi0, pp->max_bytes_per_pkt);
+	}
     }
 }