ip: save fib index for buffer in ip lookup

Avoids recomputing the fib index in ip local for locally delivered
packets and should incur no extra cost when forwarding packets.

Change-Id: Id826ffa8206392087327f154337eabc8a801b4d7
Signed-off-by: Florin Coras <fcoras@cisco.com>

5 files changed, 65 insertions, 114 deletions

diff --git a/src/vnet/ip/ip4_forward.c b/src/vnet/ip/ip4_forward.c
index 40fe9dc447e..04cfac0d6be 100644
--- a/src/vnet/ip/ip4_forward.c
+++ b/src/vnet/ip/ip4_forward.c
@@ -1202,8 +1202,8 @@ ip4_local_inline (vlib_main_t * vm,
 	  ip4_fib_mtrie_leaf_t leaf0, leaf1;
 	  const dpo_id_t *dpo0, *dpo1;
 	  const load_balance_t *lb0, *lb1;
-	  u32 pi0, next0, fib_index0, lbi0;
-	  u32 pi1, next1, fib_index1, lbi1;
+	  u32 pi0, next0, lbi0;
+	  u32 pi1, next1, lbi1;
 	  u8 error0, is_udp0, is_tcp_udp0, good_tcp_udp0, proto0;
 	  u8 error1, is_udp1, is_tcp_udp1, good_tcp_udp1, proto1;
 	  u32 sw_if_index0, sw_if_index1;
@@ -1268,22 +1268,19 @@ ip4_local_inline (vlib_main_t * vm,
 	  error1 = (is_tcp_udp1 && !good_tcp_udp1
 		    ? IP4_ERROR_TCP_CHECKSUM + is_udp1 : error1);
 
-	  fib_index0 = vec_elt (im->fib_index_by_sw_if_index, sw_if_index0);
-	  fib_index0 =
-	    (vnet_buffer (p0)->sw_if_index[VLIB_TX] ==
-	     (u32) ~ 0) ? fib_index0 : vnet_buffer (p0)->sw_if_index[VLIB_TX];
+	  vnet_buffer (p0)->ip.fib_index =
+	    vnet_buffer (p0)->sw_if_index[VLIB_TX] != ~0 ?
+	    vnet_buffer (p0)->sw_if_index[VLIB_TX] :
+	    vnet_buffer (p0)->ip.fib_index;
 
-	  fib_index1 = vec_elt (im->fib_index_by_sw_if_index, sw_if_index1);
-	  fib_index1 =
-	    (vnet_buffer (p1)->sw_if_index[VLIB_TX] ==
-	     (u32) ~ 0) ? fib_index1 : vnet_buffer (p1)->sw_if_index[VLIB_TX];
+	  vnet_buffer (p1)->ip.fib_index =
+	    vnet_buffer (p1)->sw_if_index[VLIB_TX] != ~0 ?
+	    vnet_buffer (p1)->sw_if_index[VLIB_TX] :
+	    vnet_buffer (p1)->ip.fib_index;
 
-	  /* TODO maybe move to lookup? */
-	  vnet_buffer (p0)->ip.fib_index = fib_index0;
-	  vnet_buffer (p1)->ip.fib_index = fib_index1;
 
-	  mtrie0 = &ip4_fib_get (fib_index0)->mtrie;
-	  mtrie1 = &ip4_fib_get (fib_index1)->mtrie;
+	  mtrie0 = &ip4_fib_get (vnet_buffer (p0)->ip.fib_index)->mtrie;
+	  mtrie1 = &ip4_fib_get (vnet_buffer (p1)->ip.fib_index)->mtrie;
 
 	  leaf0 = ip4_fib_mtrie_lookup_step_one (mtrie0, &ip0->src_address);
 	  leaf1 = ip4_fib_mtrie_lookup_step_one (mtrie1, &ip1->src_address);
@@ -1374,7 +1371,7 @@ ip4_local_inline (vlib_main_t * vm,
 	  ip4_header_t *ip0;
 	  ip4_fib_mtrie_t *mtrie0;
 	  ip4_fib_mtrie_leaf_t leaf0;
-	  u32 pi0, next0, fib_index0, lbi0;
+	  u32 pi0, next0, lbi0;
 	  u8 error0, is_udp0, is_tcp_udp0, good_tcp_udp0, proto0;
 	  load_balance_t *lb0;
 	  const dpo_id_t *dpo0;
@@ -1417,12 +1414,12 @@ ip4_local_inline (vlib_main_t * vm,
 	  error0 = (is_tcp_udp0 && !good_tcp_udp0
 		    ? IP4_ERROR_TCP_CHECKSUM + is_udp0 : error0);
 
-	  fib_index0 = vec_elt (im->fib_index_by_sw_if_index, sw_if_index0);
-	  fib_index0 =
-	    (vnet_buffer (p0)->sw_if_index[VLIB_TX] ==
-	     (u32) ~ 0) ? fib_index0 : vnet_buffer (p0)->sw_if_index[VLIB_TX];
-	  vnet_buffer (p0)->ip.fib_index = fib_index0;
-	  mtrie0 = &ip4_fib_get (fib_index0)->mtrie;
+	  vnet_buffer (p0)->ip.fib_index =
+	    vnet_buffer (p0)->sw_if_index[VLIB_TX] != ~0 ?
+	    vnet_buffer (p0)->sw_if_index[VLIB_TX] :
+	    vnet_buffer (p0)->ip.fib_index;
+
+	  mtrie0 = &ip4_fib_get (vnet_buffer (p0)->ip.fib_index)->mtrie;
 	  leaf0 = ip4_fib_mtrie_lookup_step_one (mtrie0, &ip0->src_address);
 	  leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address,
 					     2);
diff --git a/src/vnet/ip/ip4_forward.h b/src/vnet/ip/ip4_forward.h
index 71f58f14e6d..553a0536c6c 100644
--- a/src/vnet/ip/ip4_forward.h
+++ b/src/vnet/ip/ip4_forward.h
@@ -79,10 +79,7 @@ ip4_lookup_inline (vlib_main_t * vm,
 	  ip4_fib_mtrie_t *mtrie0, *mtrie1, *mtrie2, *mtrie3;
 	  ip4_fib_mtrie_leaf_t leaf0, leaf1, leaf2, leaf3;
 	  ip4_address_t *dst_addr0, *dst_addr1, *dst_addr2, *dst_addr3;
-	  u32 pi0, fib_index0, lb_index0;
-	  u32 pi1, fib_index1, lb_index1;
-	  u32 pi2, fib_index2, lb_index2;
-	  u32 pi3, fib_index3, lb_index3;
+	  u32 pi0, pi1, pi2, pi3, lb_index0, lb_index1, lb_index2, lb_index3;
 	  flow_hash_config_t flow_hash_config0, flow_hash_config1;
 	  flow_hash_config_t flow_hash_config2, flow_hash_config3;
 	  u32 hash_c0, hash_c1, hash_c2, hash_c3;
@@ -133,38 +130,17 @@ ip4_lookup_inline (vlib_main_t * vm,
 	  dst_addr2 = &ip2->dst_address;
 	  dst_addr3 = &ip3->dst_address;
 
-	  fib_index0 =
-	    vec_elt (im->fib_index_by_sw_if_index,
-		     vnet_buffer (p0)->sw_if_index[VLIB_RX]);
-	  fib_index1 =
-	    vec_elt (im->fib_index_by_sw_if_index,
-		     vnet_buffer (p1)->sw_if_index[VLIB_RX]);
-	  fib_index2 =
-	    vec_elt (im->fib_index_by_sw_if_index,
-		     vnet_buffer (p2)->sw_if_index[VLIB_RX]);
-	  fib_index3 =
-	    vec_elt (im->fib_index_by_sw_if_index,
-		     vnet_buffer (p3)->sw_if_index[VLIB_RX]);
-	  fib_index0 =
-	    (vnet_buffer (p0)->sw_if_index[VLIB_TX] ==
-	     (u32) ~ 0) ? fib_index0 : vnet_buffer (p0)->sw_if_index[VLIB_TX];
-	  fib_index1 =
-	    (vnet_buffer (p1)->sw_if_index[VLIB_TX] ==
-	     (u32) ~ 0) ? fib_index1 : vnet_buffer (p1)->sw_if_index[VLIB_TX];
-	  fib_index2 =
-	    (vnet_buffer (p2)->sw_if_index[VLIB_TX] ==
-	     (u32) ~ 0) ? fib_index2 : vnet_buffer (p2)->sw_if_index[VLIB_TX];
-	  fib_index3 =
-	    (vnet_buffer (p3)->sw_if_index[VLIB_TX] ==
-	     (u32) ~ 0) ? fib_index3 : vnet_buffer (p3)->sw_if_index[VLIB_TX];
-
+	  ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p0);
+	  ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p1);
+	  ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p2);
+	  ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p3);
 
 	  if (!lookup_for_responses_to_locally_received_packets)
 	    {
-	      mtrie0 = &ip4_fib_get (fib_index0)->mtrie;
-	      mtrie1 = &ip4_fib_get (fib_index1)->mtrie;
-	      mtrie2 = &ip4_fib_get (fib_index2)->mtrie;
-	      mtrie3 = &ip4_fib_get (fib_index3)->mtrie;
+	      mtrie0 = &ip4_fib_get (vnet_buffer (p0)->ip.fib_index)->mtrie;
+	      mtrie1 = &ip4_fib_get (vnet_buffer (p1)->ip.fib_index)->mtrie;
+	      mtrie2 = &ip4_fib_get (vnet_buffer (p2)->ip.fib_index)->mtrie;
+	      mtrie3 = &ip4_fib_get (vnet_buffer (p3)->ip.fib_index)->mtrie;
 
 	      leaf0 = ip4_fib_mtrie_lookup_step_one (mtrie0, dst_addr0);
 	      leaf1 = ip4_fib_mtrie_lookup_step_one (mtrie1, dst_addr1);
@@ -317,7 +293,7 @@ ip4_lookup_inline (vlib_main_t * vm,
 	  ip4_fib_mtrie_t *mtrie0;
 	  ip4_fib_mtrie_leaf_t leaf0;
 	  ip4_address_t *dst_addr0;
-	  u32 pi0, fib_index0, lbi0;
+	  u32 pi0, lbi0;
 	  flow_hash_config_t flow_hash_config0;
 	  const dpo_id_t *dpo0;
 	  u32 hash_c0;
@@ -326,22 +302,13 @@ ip4_lookup_inline (vlib_main_t * vm,
 	  to_next[0] = pi0;
 
 	  p0 = vlib_get_buffer (vm, pi0);
-
 	  ip0 = vlib_buffer_get_current (p0);
-
 	  dst_addr0 = &ip0->dst_address;
-
-	  fib_index0 =
-	    vec_elt (im->fib_index_by_sw_if_index,
-		     vnet_buffer (p0)->sw_if_index[VLIB_RX]);
-	  fib_index0 =
-	    (vnet_buffer (p0)->sw_if_index[VLIB_TX] ==
-	     (u32) ~ 0) ? fib_index0 : vnet_buffer (p0)->sw_if_index[VLIB_TX];
+	  ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p0);
 
 	  if (!lookup_for_responses_to_locally_received_packets)
 	    {
-	      mtrie0 = &ip4_fib_get (fib_index0)->mtrie;
-
+	      mtrie0 = &ip4_fib_get (vnet_buffer (p0)->ip.fib_index)->mtrie;
 	      leaf0 = ip4_fib_mtrie_lookup_step_one (mtrie0, dst_addr0);
 	    }
 
diff --git a/src/vnet/ip/ip6_forward.c b/src/vnet/ip/ip6_forward.c
index f4c51e22bfc..275bcc67b69 100644
--- a/src/vnet/ip/ip6_forward.c
+++ b/src/vnet/ip/ip6_forward.c
@@ -1213,23 +1213,15 @@ ip6_local_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 			? IP6_ERROR_SRC_LOOKUP_MISS : error1);
 	    }
 
-	  /* TODO maybe move to lookup? */
 	  vnet_buffer (p0)->ip.fib_index =
-	    vec_elt (im->fib_index_by_sw_if_index,
-		     vnet_buffer (p0)->sw_if_index[VLIB_RX]);
-	  vnet_buffer (p0)->ip.fib_index =
-	    (vnet_buffer (p0)->sw_if_index[VLIB_TX] ==
-	     (u32) ~ 0) ? vnet_buffer (p0)->ip.
-	    fib_index : vnet_buffer (p0)->sw_if_index[VLIB_TX];
+	    vnet_buffer (p0)->sw_if_index[VLIB_TX] != ~0 ?
+	    vnet_buffer (p0)->sw_if_index[VLIB_TX] :
+	    vnet_buffer (p0)->ip.fib_index;
 
 	  vnet_buffer (p1)->ip.fib_index =
-	    vec_elt (im->fib_index_by_sw_if_index,
-		     vnet_buffer (p1)->sw_if_index[VLIB_RX]);
-	  vnet_buffer (p1)->ip.fib_index =
-	    (vnet_buffer (p1)->sw_if_index[VLIB_TX] ==
-	     (u32) ~ 0) ? vnet_buffer (p1)->ip.
-	    fib_index : vnet_buffer (p1)->sw_if_index[VLIB_TX];
-
+	    vnet_buffer (p1)->sw_if_index[VLIB_TX] != ~0 ?
+	    vnet_buffer (p1)->sw_if_index[VLIB_TX] :
+	    vnet_buffer (p1)->ip.fib_index;
 
 	skip_checks:
 
@@ -1343,14 +1335,10 @@ ip6_local_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 	      error0 = (!ip6_urpf_loose_check (im, p0, ip0)
 			? IP6_ERROR_SRC_LOOKUP_MISS : error0);
 	    }
-
-	  vnet_buffer (p0)->ip.fib_index =
-	    vec_elt (im->fib_index_by_sw_if_index,
-		     vnet_buffer (p0)->sw_if_index[VLIB_RX]);
 	  vnet_buffer (p0)->ip.fib_index =
-	    (vnet_buffer (p0)->sw_if_index[VLIB_TX] ==
-	     (u32) ~ 0) ? vnet_buffer (p0)->ip.
-	    fib_index : vnet_buffer (p0)->sw_if_index[VLIB_TX];
+	    vnet_buffer (p0)->sw_if_index[VLIB_TX] != ~0 ?
+	    vnet_buffer (p0)->sw_if_index[VLIB_TX] :
+	    vnet_buffer (p0)->ip.fib_index;
 
 	skip_check:
 
diff --git a/src/vnet/ip/ip6_forward.h b/src/vnet/ip/ip6_forward.h
index 790a2bb1ac1..fcdcabd1e00 100644
--- a/src/vnet/ip/ip6_forward.h
+++ b/src/vnet/ip/ip6_forward.h
@@ -76,7 +76,6 @@ ip6_lookup_inline (vlib_main_t * vm,
 	  ip_lookup_next_t next0, next1;
 	  ip6_header_t *ip0, *ip1;
 	  ip6_address_t *dst_addr0, *dst_addr1;
-	  u32 fib_index0, fib_index1;
 	  u32 flow_hash_config0, flow_hash_config1;
 	  const dpo_id_t *dpo0, *dpo1;
 	  const load_balance_t *lb0, *lb1;
@@ -106,20 +105,15 @@ ip6_lookup_inline (vlib_main_t * vm,
 	  dst_addr0 = &ip0->dst_address;
 	  dst_addr1 = &ip1->dst_address;
 
-	  fib_index0 =
-	    vec_elt (im->fib_index_by_sw_if_index,
-		     vnet_buffer (p0)->sw_if_index[VLIB_RX]);
-	  fib_index1 =
-	    vec_elt (im->fib_index_by_sw_if_index,
-		     vnet_buffer (p1)->sw_if_index[VLIB_RX]);
+	  ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p0);
+	  ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p1);
 
-	  fib_index0 = (vnet_buffer (p0)->sw_if_index[VLIB_TX] == (u32) ~ 0) ?
-	    fib_index0 : vnet_buffer (p0)->sw_if_index[VLIB_TX];
-	  fib_index1 = (vnet_buffer (p1)->sw_if_index[VLIB_TX] == (u32) ~ 0) ?
-	    fib_index1 : vnet_buffer (p1)->sw_if_index[VLIB_TX];
-
-	  lbi0 = ip6_fib_table_fwding_lookup (im, fib_index0, dst_addr0);
-	  lbi1 = ip6_fib_table_fwding_lookup (im, fib_index1, dst_addr1);
+	  lbi0 = ip6_fib_table_fwding_lookup (im,
+					      vnet_buffer (p0)->ip.fib_index,
+					      dst_addr0);
+	  lbi1 = ip6_fib_table_fwding_lookup (im,
+					      vnet_buffer (p1)->ip.fib_index,
+					      dst_addr1);
 
 	  lb0 = load_balance_get (lbi0);
 	  lb1 = load_balance_get (lbi1);
@@ -233,26 +227,19 @@ ip6_lookup_inline (vlib_main_t * vm,
 	  ip_lookup_next_t next0;
 	  load_balance_t *lb0;
 	  ip6_address_t *dst_addr0;
-	  u32 fib_index0, flow_hash_config0;
+	  u32 flow_hash_config0;
 	  const dpo_id_t *dpo0;
 
 	  pi0 = from[0];
 	  to_next[0] = pi0;
 
 	  p0 = vlib_get_buffer (vm, pi0);
-
 	  ip0 = vlib_buffer_get_current (p0);
-
 	  dst_addr0 = &ip0->dst_address;
-
-	  fib_index0 =
-	    vec_elt (im->fib_index_by_sw_if_index,
-		     vnet_buffer (p0)->sw_if_index[VLIB_RX]);
-	  fib_index0 =
-	    (vnet_buffer (p0)->sw_if_index[VLIB_TX] ==
-	     (u32) ~ 0) ? fib_index0 : vnet_buffer (p0)->sw_if_index[VLIB_TX];
-
-	  lbi0 = ip6_fib_table_fwding_lookup (im, fib_index0, dst_addr0);
+	  ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p0);
+	  lbi0 = ip6_fib_table_fwding_lookup (im,
+					      vnet_buffer (p0)->ip.fib_index,
+					      dst_addr0);
 
 	  lb0 = load_balance_get (lbi0);
 	  flow_hash_config0 = lb0->lb_hash_config;
diff --git a/src/vnet/ip/lookup.h b/src/vnet/ip/lookup.h
index a89546f5d92..ecabd817a00 100644
--- a/src/vnet/ip/lookup.h
+++ b/src/vnet/ip/lookup.h
@@ -211,6 +211,18 @@ do {                                                                    \
 } while (0)
 /* *INDENT-ON* */
 
+always_inline void
+ip_lookup_set_buffer_fib_index (u32 * fib_index_by_sw_if_index,
+				vlib_buffer_t * b)
+{
+  vnet_buffer (b)->ip.fib_index =
+    vec_elt (fib_index_by_sw_if_index, vnet_buffer (b)->sw_if_index[VLIB_RX]);
+  vnet_buffer (b)->ip.fib_index =
+    (vnet_buffer (b)->sw_if_index[VLIB_TX] ==
+     (u32) ~ 0) ? vnet_buffer (b)->ip.
+    fib_index : vnet_buffer (b)->sw_if_index[VLIB_TX];
+}
+
 typedef struct _vnet_ip_container_proxy_args
 {
   fib_prefix_t prefix;