acl-plugin: bihash-based ACL lookup

Add a bihash-based ACL lookup mechanism and make it a new default.
This changes the time required to lookup a 5-tuple match
from O(total_N_entries) to O(total_N_mask_types), where
"mask type" is an overall mask on the 5-tuple required
to represent an ACE.

For testing/comparison there is a temporary debug CLI
"set acl-plugin use-hash-acl-matching {0|1}", which,
when set to 0, makes the plugin use the "old" linear lookup,
and when set to 1, makes it use the hash-based lookup.

Based on the discussions on vpp-dev mailing list,
prevent assigning the ACL index to an interface,
when the ACL with that index is not defined,
also prevent deleting an ACL if that ACL is applied.

Also, for the easier debugging of the state, there are
new debug CLI commands to see the ACL plugin state at
several layers:

"show acl-plugin acl [index N]" - show a high-level
ACL representation, used for the linear lookup and
as a base for building the hashtable-based lookup.
Also shows if a given ACL is applied somewhere.

"show acl-plugin interface [sw_if_index N]" - show
which interfaces have which ACL(s) applied.

"show acl-plugin tables" - a lower-level debug command
used to see the state of all of the related data structures
at once. There are specifiers possible, which make
for a more focused and maybe augmented output:

"show acl-plugin tables acl [index N]"
show the "bitmask-ready" representations of the ACLs,
we well as the mask types and their associated indices.

"show acl-plutin tables mask"
show the derived mask types and their indices only.

"show acl-plugin tables applied [sw_if_index N]"
show the table of all of the ACEs applied for a given
sw_if_index or all interfaces.

"show acl-plugin tables hash [verbose N]"
show the 48x8 bihash used for the ACL lookup.

Change-Id: I89fff051424cb44bcb189e3cee04c1b8f76efc28
Signed-off-by: Andrew Yourtchenko <ayourtch@gmail.com>

1 files changed, 35 insertions, 4 deletions

diff --git a/src/plugins/acl/fa_node.c b/src/plugins/acl/fa_node.c
index 66621b6ba78..bfb2fc1eaca 100644
--- a/src/plugins/acl/fa_node.c
+++ b/src/plugins/acl/fa_node.c
@@ -26,6 +26,7 @@
 #include <vppinfra/bihash_template.c>
 
 #include "fa_node.h"
+#include "hash_lookup.h"
 
 typedef struct
 {
@@ -136,7 +137,7 @@ fa_acl_match_port (u16 port, u16 port_first, u16 port_last, int is_ip6)
 }
 
 int
-acl_match_5tuple (acl_main_t * am, u32 acl_index, fa_5tuple_t * pkt_5tuple,
+single_acl_match_5tuple (acl_main_t * am, u32 acl_index, fa_5tuple_t * pkt_5tuple,
 		  int is_ip6, u8 * r_action, u32 * r_acl_match_p,
 		  u32 * r_rule_match_p, u32 * trace_bitmap)
 {
@@ -259,7 +260,7 @@ acl_match_5tuple (acl_main_t * am, u32 acl_index, fa_5tuple_t * pkt_5tuple,
 }
 
 static u8
-full_acl_match_5tuple (u32 sw_if_index, fa_5tuple_t * pkt_5tuple, int is_l2,
+linear_multi_acl_match_5tuple (u32 sw_if_index, fa_5tuple_t * pkt_5tuple, int is_l2,
 		       int is_ip6, int is_input, u32 * acl_match_p,
 		       u32 * rule_match_p, u32 * trace_bitmap)
 {
@@ -284,7 +285,7 @@ full_acl_match_5tuple (u32 sw_if_index, fa_5tuple_t * pkt_5tuple, int is_l2,
       clib_warning ("ACL_FA_NODE_DBG: Trying to match ACL: %d",
 		    acl_vector[i]);
 #endif
-      if (acl_match_5tuple
+      if (single_acl_match_5tuple
 	  (am, acl_vector[i], pkt_5tuple, is_ip6, &action,
 	   acl_match_p, rule_match_p, trace_bitmap))
 	{
@@ -303,6 +304,21 @@ full_acl_match_5tuple (u32 sw_if_index, fa_5tuple_t * pkt_5tuple, int is_l2,
   return 0;
 }
 
+static u8
+multi_acl_match_5tuple (u32 sw_if_index, fa_5tuple_t * pkt_5tuple, int is_l2,
+                       int is_ip6, int is_input, u32 * acl_match_p,
+                       u32 * rule_match_p, u32 * trace_bitmap)
+{
+  acl_main_t *am = &acl_main;
+  if (am->use_hash_acl_matching) {
+    return hash_multi_acl_match_5tuple(sw_if_index, pkt_5tuple, is_l2, is_ip6,
+                                 is_input, acl_match_p, rule_match_p, trace_bitmap);
+  } else {
+    return linear_multi_acl_match_5tuple(sw_if_index, pkt_5tuple, is_l2, is_ip6,
+                                 is_input, acl_match_p, rule_match_p, trace_bitmap);
+  }
+}
+
 static int
 offset_within_packet (vlib_buffer_t * b0, int offset)
 {
@@ -973,6 +989,10 @@ acl_fa_node_fn (vlib_main_t * vm,
 	  acl_fill_5tuple (am, b0, is_ip6, is_input, is_l2_path, &fa_5tuple);
           fa_5tuple.l4.lsb_of_sw_if_index = sw_if_index0 & 0xffff;
 	  acl_make_5tuple_session_key (is_input, &fa_5tuple, &kv_sess);
+	  fa_5tuple.pkt.sw_if_index = sw_if_index0;
+          fa_5tuple.pkt.is_ip6 = is_ip6;
+          fa_5tuple.pkt.is_input = is_input;
+          fa_5tuple.pkt.mask_type_index_lsb = ~0;
 #ifdef FA_NODE_VERBOSE_DEBUG
 	  clib_warning
 	    ("ACL_FA_NODE_DBG: session 5-tuple %016llx %016llx %016llx %016llx %016llx : %016llx",
@@ -1039,7 +1059,7 @@ acl_fa_node_fn (vlib_main_t * vm,
 	  if (acl_check_needed)
 	    {
 	      action =
-		full_acl_match_5tuple (sw_if_index0, &fa_5tuple, is_l2_path,
+		multi_acl_match_5tuple (sw_if_index0, &fa_5tuple, is_l2_path,
 				       is_ip6, is_input, &match_acl_in_index,
 				       &match_rule_index, &trace_bitmap);
 	      error0 = action;
@@ -1590,6 +1610,17 @@ acl_fa_enable_disable (u32 sw_if_index, int is_input, int enable_disable)
     }
 }
 
+void
+show_fa_sessions_hash(vlib_main_t * vm, u32 verbose)
+{
+  acl_main_t *am = &acl_main;
+  if (am->fa_sessions_hash_is_initialized) {
+    vlib_cli_output(vm, "\nSession lookup hash table:\n%U\n\n",
+                  BV (format_bihash), &am->fa_sessions_hash, verbose);
+  } else {
+    vlib_cli_output(vm, "\nSession lookup hash table is not allocated.\n\n");
+  }
+}
 
 
 /* *INDENT-OFF* */