Introduce l{2,3,4}_hdr_offset fields in the buffer metadata

To save space in the first cacheline following is changed:

- total_length_not_including_first_buffer moved to the 2nd cacheline.
This field is used only when VLIB_BUFFER_TOTAL_LENGTH_VALID and
VLIB_BUFFER_NEXT_PRESENT are both set.

- free_list_index is now stored in 4bits inside flags, which
allows up to 16 free lists. In case we need more we can store index
in the 2nd cachelin

Change-Id: Ic8521350819391af470d31d3fa1013e67ecb7681
Signed-off-by: Damjan Marion <damarion@cisco.com>

12 files changed, 36 insertions, 53 deletions

diff --git a/src/vnet/bfd/bfd_udp.c b/src/vnet/bfd/bfd_udp.c
index 346c54956fe..06b843c6e95 100644
--- a/src/vnet/bfd/bfd_udp.c
+++ b/src/vnet/bfd/bfd_udp.c
@@ -843,7 +843,7 @@ bfd_udp4_find_headers (vlib_buffer_t * b, ip4_header_t ** ip4,
 		       udp_header_t ** udp)
 {
   /* sanity check first */
-  const i32 start = vnet_buffer (b)->ip.start_of_ip_header;
+  const i32 start = vnet_buffer (b)->l3_hdr_offset;
   if (start < 0 && start < sizeof (b->pre_data))
     {
       BFD_ERR ("Start of ip header is before pre_data, ignoring");
@@ -1000,7 +1000,7 @@ bfd_udp6_find_headers (vlib_buffer_t * b, ip6_header_t ** ip6,
 		       udp_header_t ** udp)
 {
   /* sanity check first */
-  const i32 start = vnet_buffer (b)->ip.start_of_ip_header;
+  const i32 start = vnet_buffer (b)->l3_hdr_offset;
   if (start < 0 && start < sizeof (b->pre_data))
     {
       BFD_ERR ("Start of ip header is before pre_data, ignoring");
diff --git a/src/vnet/buffer.h b/src/vnet/buffer.h
index 9aba34da930..8647db005f4 100644
--- a/src/vnet/buffer.h
+++ b/src/vnet/buffer.h
@@ -71,7 +71,6 @@
 #define VNET_BUFFER_SPAN_CLONE (1 << LOG2_VNET_BUFFER_SPAN_CLONE)
 
 #define foreach_buffer_opaque_union_subtype     \
-_(ethernet)                                     \
 _(ip)                                           \
 _(swt)                                          \
 _(l2)                                           \
@@ -100,16 +99,12 @@ _(tcp)
 typedef struct
 {
   u32 sw_if_index[VLIB_N_RX_TX];
+  i16 l2_hdr_offset;
+  i16 l3_hdr_offset;
+  i16 l4_hdr_offset;
 
   union
   {
-    /* Ethernet. */
-    struct
-    {
-      /* Saved value of current header by ethernet-input. */
-      i32 start_of_ethernet_header;
-    } ethernet;
-
     /* IP4/6 buffer opaque. */
     struct
     {
@@ -143,9 +138,6 @@ typedef struct
 	  u8 code;
 	  u32 data;
 	} icmp;
-
-	/* IP header offset from vlib_buffer.data - saved by ip*_local nodes */
-	i32 start_of_ip_header;
       };
 
     } ip;
diff --git a/src/vnet/dhcp/dhcp4_proxy_node.c b/src/vnet/dhcp/dhcp4_proxy_node.c
index 26e1e65cd4c..1b59cdea0d9 100644
--- a/src/vnet/dhcp/dhcp4_proxy_node.c
+++ b/src/vnet/dhcp/dhcp4_proxy_node.c
@@ -231,7 +231,7 @@ dhcp_proxy_to_server_input (vlib_main_t * vm,
               o = (dhcp_option_t *) (((uword) o) + (o->length + 2));
           }
 
-          fl = vlib_buffer_get_free_list (vm, b0->free_list_index);
+          fl = vlib_buffer_get_free_list (vm, vlib_buffer_get_free_list_index (b0));
           // start write at (option*)o, some packets have padding
           if (((u8 *)o - (u8 *)b0->data + VPP_DHCP_OPTION82_SIZE) > fl->n_data_bytes)
           {
diff --git a/src/vnet/dhcp/dhcp6_proxy_node.c b/src/vnet/dhcp/dhcp6_proxy_node.c
index 885313a588e..e109cc4cc59 100644
--- a/src/vnet/dhcp/dhcp6_proxy_node.c
+++ b/src/vnet/dhcp/dhcp6_proxy_node.c
@@ -306,7 +306,7 @@ dhcpv6_proxy_to_server_input (vlib_main_t * vm,
           copy_ip6_address(&r1->link_addr, ia0);
 
         link_address_set:
-          fl = vlib_buffer_get_free_list (vm, b0->free_list_index);
+          fl = vlib_buffer_get_free_list (vm, vlib_buffer_get_free_list_index (b0));
 
           if ((b0->current_length+sizeof(*id1)+sizeof(*vss1)+sizeof(*cmac))
               > fl->n_data_bytes)
diff --git a/src/vnet/ethernet/ethernet.h b/src/vnet/ethernet/ethernet.h
index dcc656a7dbb..2fc5b804dc3 100644
--- a/src/vnet/ethernet/ethernet.h
+++ b/src/vnet/ethernet/ethernet.h
@@ -344,8 +344,7 @@ ethernet_setup_node (vlib_main_t * vm, u32 node_index)
 always_inline ethernet_header_t *
 ethernet_buffer_get_header (vlib_buffer_t * b)
 {
-  return (void *)
-    (b->data + vnet_buffer (b)->ethernet.start_of_ethernet_header);
+  return (void *) (b->data + vnet_buffer (b)->l2_hdr_offset);
 }
 
 /** Returns the number of VLAN headers in the current Ethernet frame in the
diff --git a/src/vnet/ethernet/node.c b/src/vnet/ethernet/node.c
index d9fdff48287..421d501adda 100755
--- a/src/vnet/ethernet/node.c
+++ b/src/vnet/ethernet/node.c
@@ -101,7 +101,7 @@ parse_header (ethernet_input_variant_t variant,
 
       e0 = (void *) (b0->data + b0->current_data);
 
-      vnet_buffer (b0)->ethernet.start_of_ethernet_header = b0->current_data;
+      vnet_buffer (b0)->l2_hdr_offset = b0->current_data;
 
       vlib_buffer_advance (b0, sizeof (e0[0]));
 
@@ -205,9 +205,7 @@ identify_subint (vnet_hw_interface_t * hi,
       if (!(*is_l2))
 	{
 	  ethernet_header_t *e0;
-	  e0 =
-	    (void *) (b0->data +
-		      vnet_buffer (b0)->ethernet.start_of_ethernet_header);
+	  e0 = (void *) (b0->data + vnet_buffer (b0)->l2_hdr_offset);
 
 	  if (!(ethernet_address_cast (e0->dst_address)))
 	    {
@@ -238,7 +236,7 @@ determine_next_node (ethernet_main_t * em,
     {
       *next0 = em->l2_next;
       // record the L2 len and reset the buffer so the L2 header is preserved
-      u32 eth_start = vnet_buffer (b0)->ethernet.start_of_ethernet_header;
+      u32 eth_start = vnet_buffer (b0)->l2_hdr_offset;
       vnet_buffer (b0)->l2.l2_len = b0->current_data - eth_start;
       ASSERT (vnet_buffer (b0)->l2.l2_len ==
 	      ethernet_buffer_header_size (b0));
@@ -424,10 +422,8 @@ ethernet_input_inline (vlib_main_t * vm,
 		  cached_is_l2 = is_l20 = subint0->flags & SUBINT_CONFIG_L2;
 		}
 
-	      vnet_buffer (b0)->ethernet.start_of_ethernet_header =
-		b0->current_data;
-	      vnet_buffer (b1)->ethernet.start_of_ethernet_header =
-		b1->current_data;
+	      vnet_buffer (b0)->l2_hdr_offset = b0->current_data;
+	      vnet_buffer (b1)->l2_hdr_offset = b1->current_data;
 
 	      if (PREDICT_TRUE (is_l20 != 0))
 		{
@@ -519,9 +515,9 @@ ethernet_input_inline (vlib_main_t * vm,
 	    {
 
 	      len0 = vlib_buffer_length_in_chain (vm, b0) + b0->current_data
-		- vnet_buffer (b0)->ethernet.start_of_ethernet_header;
+		- vnet_buffer (b0)->l2_hdr_offset;
 	      len1 = vlib_buffer_length_in_chain (vm, b1) + b1->current_data
-		- vnet_buffer (b1)->ethernet.start_of_ethernet_header;
+		- vnet_buffer (b1)->l2_hdr_offset;
 
 	      stats_n_packets += 2;
 	      stats_n_bytes += len0 + len1;
@@ -646,8 +642,7 @@ ethernet_input_inline (vlib_main_t * vm,
 		  cached_is_l2 = is_l20 = subint0->flags & SUBINT_CONFIG_L2;
 		}
 
-	      vnet_buffer (b0)->ethernet.start_of_ethernet_header =
-		b0->current_data;
+	      vnet_buffer (b0)->l2_hdr_offset = b0->current_data;
 
 	      if (PREDICT_TRUE (is_l20 != 0))
 		{
@@ -710,7 +705,7 @@ ethernet_input_inline (vlib_main_t * vm,
 	    {
 
 	      len0 = vlib_buffer_length_in_chain (vm, b0) + b0->current_data
-		- vnet_buffer (b0)->ethernet.start_of_ethernet_header;
+		- vnet_buffer (b0)->l2_hdr_offset;
 
 	      stats_n_packets += 1;
 	      stats_n_bytes += len0;
diff --git a/src/vnet/ip/ip4_forward.c b/src/vnet/ip/ip4_forward.c
index 8263e01c188..b8dfa8474eb 100755
--- a/src/vnet/ip/ip4_forward.c
+++ b/src/vnet/ip/ip4_forward.c
@@ -1585,8 +1585,8 @@ ip4_local_inline (vlib_main_t * vm,
 	  ip0 = vlib_buffer_get_current (p0);
 	  ip1 = vlib_buffer_get_current (p1);
 
-	  vnet_buffer (p0)->ip.start_of_ip_header = p0->current_data;
-	  vnet_buffer (p1)->ip.start_of_ip_header = p1->current_data;
+	  vnet_buffer (p0)->l3_hdr_offset = p0->current_data;
+	  vnet_buffer (p1)->l3_hdr_offset = p1->current_data;
 
 	  sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
 	  sw_if_index1 = vnet_buffer (p1)->sw_if_index[VLIB_RX];
@@ -1788,7 +1788,7 @@ ip4_local_inline (vlib_main_t * vm,
 
 	  ip0 = vlib_buffer_get_current (p0);
 
-	  vnet_buffer (p0)->ip.start_of_ip_header = p0->current_data;
+	  vnet_buffer (p0)->l3_hdr_offset = p0->current_data;
 
 	  sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
 
diff --git a/src/vnet/ip/ip6_forward.c b/src/vnet/ip/ip6_forward.c
index 4b574b9adbd..2b8c2bd2f7c 100644
--- a/src/vnet/ip/ip6_forward.c
+++ b/src/vnet/ip/ip6_forward.c
@@ -1362,8 +1362,8 @@ ip6_local (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
 	  ip0 = vlib_buffer_get_current (p0);
 	  ip1 = vlib_buffer_get_current (p1);
 
-	  vnet_buffer (p0)->ip.start_of_ip_header = p0->current_data;
-	  vnet_buffer (p1)->ip.start_of_ip_header = p1->current_data;
+	  vnet_buffer (p0)->l3_hdr_offset = p0->current_data;
+	  vnet_buffer (p1)->l3_hdr_offset = p1->current_data;
 
 	  type0 = lm->builtin_protocol_by_ip_protocol[ip0->protocol];
 	  type1 = lm->builtin_protocol_by_ip_protocol[ip1->protocol];
@@ -1493,7 +1493,7 @@ ip6_local (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
 
 	  ip0 = vlib_buffer_get_current (p0);
 
-	  vnet_buffer (p0)->ip.start_of_ip_header = p0->current_data;
+	  vnet_buffer (p0)->l3_hdr_offset = p0->current_data;
 
 	  type0 = lm->builtin_protocol_by_ip_protocol[ip0->protocol];
 	  next0 = lm->local_next_by_ip_protocol[ip0->protocol];
diff --git a/src/vnet/ip/ip6_neighbor.c b/src/vnet/ip/ip6_neighbor.c
index b8f6f9b10e7..68a8cbbc8d0 100644
--- a/src/vnet/ip/ip6_neighbor.c
+++ b/src/vnet/ip/ip6_neighbor.c
@@ -1479,9 +1479,8 @@ icmp6_router_solicitation (vlib_main_t * vm,
 			sizeof (icmp6_router_advertisement_header_t);
 
 		      vlib_buffer_add_data (vm,
-					    p0->free_list_index,
-					    bi0,
-					    (void *) &rh,
+					    vlib_buffer_get_free_list_index
+					    (p0), bi0, (void *) &rh,
 					    sizeof
 					    (icmp6_router_advertisement_header_t));
 
@@ -1499,9 +1498,8 @@ icmp6_router_solicitation (vlib_main_t * vm,
 				       eth_if0->address, 6);
 
 			  vlib_buffer_add_data (vm,
-						p0->free_list_index,
-						bi0,
-						(void *) &h,
+						vlib_buffer_get_free_list_index
+						(p0), bi0, (void *) &h,
 						sizeof
 						(icmp6_neighbor_discovery_ethernet_link_layer_address_option_t));
 
@@ -1525,9 +1523,8 @@ icmp6_router_solicitation (vlib_main_t * vm,
 			    sizeof (icmp6_neighbor_discovery_mtu_option_t);
 
 			  vlib_buffer_add_data (vm,
-						p0->free_list_index,
-						bi0,
-						(void *) &h,
+						vlib_buffer_get_free_list_index
+						(p0), bi0, (void *) &h,
 						sizeof
 						(icmp6_neighbor_discovery_mtu_option_t));
 			}
@@ -1579,7 +1576,7 @@ icmp6_router_solicitation (vlib_main_t * vm,
                             payload_length += sizeof( icmp6_neighbor_discovery_prefix_information_option_t);
 
                             vlib_buffer_add_data (vm,
-                                                  p0->free_list_index,
+					    vlib_buffer_get_free_list_index (p0),
                                                   bi0,
                                                   (void *)&h, sizeof(icmp6_neighbor_discovery_prefix_information_option_t));
 
@@ -2326,7 +2323,7 @@ ip6_neighbor_send_mldpv2_report (u32 sw_if_index)
     num_addr_records++;
 
     vlib_buffer_add_data
-      (vm, b0->free_list_index, bo0,
+      (vm, vlib_buffer_get_free_list_index (b0), bo0,
        (void *)&rr, sizeof(icmp6_multicast_address_record_t));
 
     payload_length += sizeof( icmp6_multicast_address_record_t);
diff --git a/src/vnet/l2/l2_bvi.h b/src/vnet/l2/l2_bvi.h
index e21a1616443..662ec402a87 100644
--- a/src/vnet/l2/l2_bvi.h
+++ b/src/vnet/l2/l2_bvi.h
@@ -57,7 +57,7 @@ l2_to_bvi (vlib_main_t * vlib_main,
     }
 
   /* Save L2 header position which may be changed due to packet replication */
-  vnet_buffer (b0)->ethernet.start_of_ethernet_header = b0->current_data;
+  vnet_buffer (b0)->l2_hdr_offset = b0->current_data;
 
   /* Strip L2 header */
   l2_len = vnet_buffer (b0)->l2.l2_len;
diff --git a/src/vnet/lisp-cp/control.c b/src/vnet/lisp-cp/control.c
index 22b5c82c7ce..d8a1372d7f0 100644
--- a/src/vnet/lisp-cp/control.c
+++ b/src/vnet/lisp-cp/control.c
@@ -3706,7 +3706,7 @@ send_map_reply (lisp_cp_main_t * lcm, u32 mi, ip_address_t * dst,
 static void
 find_ip_header (vlib_buffer_t * b, u8 ** ip_hdr)
 {
-  const i32 start = vnet_buffer (b)->ip.start_of_ip_header;
+  const i32 start = vnet_buffer (b)->l3_hdr_offset;
   if (start < 0 && start < -sizeof (b->pre_data))
     {
       *ip_hdr = 0;
diff --git a/src/vnet/replication.c b/src/vnet/replication.c
index 1c6f28d2493..0fdca0bf13c 100644
--- a/src/vnet/replication.c
+++ b/src/vnet/replication.c
@@ -43,12 +43,12 @@ replication_prep (vlib_main_t * vm,
   ctx_id = ctx - rm->contexts[thread_index];
 
   /* Save state from vlib buffer */
-  ctx->saved_free_list_index = b0->free_list_index;
+  ctx->saved_free_list_index = vlib_buffer_get_free_list_index (b0);
   ctx->current_data = b0->current_data;
 
   /* Set up vlib buffer hooks */
   b0->recycle_count = ctx_id;
-  b0->free_list_index = rm->recycle_list_index;
+  vlib_buffer_set_free_list_index (b0, rm->recycle_list_index);
   b0->flags |= VLIB_BUFFER_RECYCLE;
 
   /* Save feature state */
@@ -129,7 +129,7 @@ replication_recycle (vlib_main_t * vm, vlib_buffer_t * b0, u32 is_last)
        * This is the last replication in the list.
        * Restore original buffer free functionality.
        */
-      b0->free_list_index = ctx->saved_free_list_index;
+      vlib_buffer_set_free_list_index (b0, ctx->saved_free_list_index);
       b0->flags &= ~VLIB_BUFFER_RECYCLE;
 
       /* Free context back to its pool */