src/vnet/buffer.h - fdio/vpp - Gitiles

 /*
  * Copyright (c) 2015 Cisco and/or its affiliates.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 /*
  * vnet/buffer.h: vnet buffer flags
  *
  * Copyright (c) 2008 Eliot Dresselhaus
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
  * "Software"), to deal in the Software without restriction, including
  * without limitation the rights to use, copy, modify, merge, publish,
  * distribute, sublicense, and/or sell copies of the Software, and to
  * permit persons to whom the Software is furnished to do so, subject to
  * the following conditions:
  *
  * The above copyright notice and this permission notice shall be
  * included in all copies or substantial portions of the Software.
  *
  *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */

 #ifndef included_vnet_buffer_h
 #define included_vnet_buffer_h

 #include <vlib/vlib.h>

 /**
  * Flags that are set in the high order bits of ((vlib_buffer*)b)->flags
  *
  */
 #define foreach_vnet_buffer_flag                                              \
   _ (1, L4_CHECKSUM_COMPUTED, "l4-cksum-computed", 1)                         \
   _ (2, L4_CHECKSUM_CORRECT, "l4-cksum-correct", 1)                           \
   _ (3, VLAN_2_DEEP, "vlan-2-deep", 1)                                        \
   _ (4, VLAN_1_DEEP, "vlan-1-deep", 1)                                        \
   _ (5, SPAN_CLONE, "span-clone", 1)                                          \
   _ (6, LOOP_COUNTER_VALID, "loop-counter-valid", 0)                          \
   _ (7, LOCALLY_ORIGINATED, "local", 1)                                       \
   _ (8, IS_IP4, "ip4", 1)                                                     \
   _ (9, IS_IP6, "ip6", 1)                                                     \
   _ (10, OFFLOAD, "offload", 0)                                               \
   _ (11, IS_NATED, "natted", 1)                                               \
   _ (12, L2_HDR_OFFSET_VALID, "l2_hdr_offset_valid", 0)                       \
   _ (13, L3_HDR_OFFSET_VALID, "l3_hdr_offset_valid", 0)                       \
   _ (14, L4_HDR_OFFSET_VALID, "l4_hdr_offset_valid", 0)                       \
   _ (15, FLOW_REPORT, "flow-report", 1)                                       \
   _ (16, IS_DVR, "dvr", 1)                                                    \
   _ (17, QOS_DATA_VALID, "qos-data-valid", 0)                                 \
   _ (18, GSO, "gso", 0)                                                       \
   _ (19, AVAIL1, "avail1", 1)                                                 \
   _ (20, AVAIL2, "avail2", 1)                                                 \
   _ (21, AVAIL3, "avail3", 1)                                                 \
   _ (22, AVAIL4, "avail4", 1)                                                 \
   _ (23, AVAIL5, "avail5", 1)                                                 \
   _ (24, AVAIL6, "avail6", 1)                                                 \
   _ (25, AVAIL7, "avail7", 1)                                                 \
   _ (26, AVAIL8, "avail8", 1)                                                 \
   _ (27, AVAIL9, "avail9", 1)

 /*
  * Please allocate the FIRST available bit, redefine
  * AVAIL 1 ... AVAILn-1, and remove AVAILn. Please maintain the
  * VNET_BUFFER_FLAGS_ALL_AVAIL definition.
  */

 #define VNET_BUFFER_FLAGS_ALL_AVAIL                                           \
   (VNET_BUFFER_F_AVAIL1 | VNET_BUFFER_F_AVAIL2 | VNET_BUFFER_F_AVAIL3 |       \
    VNET_BUFFER_F_AVAIL4 | VNET_BUFFER_F_AVAIL5 | VNET_BUFFER_F_AVAIL6 |       \
    VNET_BUFFER_F_AVAIL7 | VNET_BUFFER_F_AVAIL8 | VNET_BUFFER_F_AVAIL9)

 #define VNET_BUFFER_FLAGS_VLAN_BITS \
   (VNET_BUFFER_F_VLAN_1_DEEP | VNET_BUFFER_F_VLAN_2_DEEP)

 enum
 {
 #define _(bit, name, s, v) VNET_BUFFER_F_##name  = (1 << LOG2_VLIB_BUFFER_FLAG_USER(bit)),
   foreach_vnet_buffer_flag
 #undef _
 };

 enum
 {
 #define _(bit, name, s, v) VNET_BUFFER_F_LOG2_##name  = LOG2_VLIB_BUFFER_FLAG_USER(bit),
   foreach_vnet_buffer_flag
 #undef _
 };

 /* Make sure that the vnet and vlib bits are disjoint */
 STATIC_ASSERT (((VNET_BUFFER_FLAGS_ALL_AVAIL & VLIB_BUFFER_FLAGS_ALL) == 0),
 	       "VLIB / VNET buffer flags overlap");

 #define foreach_vnet_buffer_offload_flag                                      \
   _ (0, IP_CKSUM, "offload-ip-cksum", 1)                                      \
   _ (1, TCP_CKSUM, "offload-tcp-cksum", 1)                                    \
   _ (2, UDP_CKSUM, "offload-udp-cksum", 1)                                    \
   _ (3, OUTER_IP_CKSUM, "offload-outer-ip-cksum", 1)                          \
   _ (4, OUTER_TCP_CKSUM, "offload-outer-tcp-cksum", 1)                        \
   _ (5, OUTER_UDP_CKSUM, "offload-outer-udp-cksum", 1)

 typedef enum
 {
 #define _(bit, name, s, v) VNET_BUFFER_OFFLOAD_F_##name = (1 << bit),
   foreach_vnet_buffer_offload_flag
 #undef _
 } vnet_buffer_oflags_t;

 #define foreach_buffer_opaque_union_subtype     \
 _(ip)                                           \
 _(l2)                                           \
 _(l2t)                                          \
 _(l2_classify)                                  \
 _(policer)                                      \
 _(ipsec)					\
 _(map)						\
 _(map_t)					\
 _(ip_frag)					\
 _(mpls)					        \
 _(tcp)

 /*
  * vnet stack buffer opaque array overlay structure.
  * The vnet_buffer_opaque_t *must* be the same size as the
  * vlib_buffer_t "opaque" structure member, 32 bytes.
  *
  * When adding a union type, please add a stanza to
  * foreach_buffer_opaque_union_subtype (directly above).
  * Code in vnet_interface_init(...) verifies the size
  * of the union, and will announce any deviations in an
  * impossible-to-miss manner.
  */
 typedef struct
 {
   u32 sw_if_index[VLIB_N_RX_TX];
   i16 l2_hdr_offset;
   i16 l3_hdr_offset;
   i16 l4_hdr_offset;
   u8 feature_arc_index;
   /* offload flags */
   vnet_buffer_oflags_t oflags : 8;

   union
   {
     /* IP4/6 buffer opaque. */
     struct
     {
       /* Adjacency from destination IP address lookup [VLIB_TX].
          Adjacency from source IP address lookup [VLIB_RX].
          This gets set to ~0 until source lookup is performed. */
       u32 adj_index[VLIB_N_RX_TX];

       union
       {
 	struct
 	{
 	  /* Flow hash value for this packet computed from IP src/dst address
 	     protocol and ports. */
 	  u32 flow_hash;

 	  union
 	  {
 	    /* next protocol */
 	    u32 save_protocol;

 	    /* Hint for transport protocols */
 	    u32 fib_index;
 	  };

 	  /* Rewrite length */
 	  u8 save_rewrite_length;

 	  /* MFIB RPF ID */
 	  u32 rpf_id;
 	};

 	/* ICMP */
 	struct
 	{
 	  u8 type;
 	  u8 code;
 	  u32 data;
 	} icmp;

 	/* reassembly */
 	union
 	{
 	  /* group input/output to simplify the code, this way
 	   * we can handoff while keeping input variables intact */
 	  struct
 	  {
 	    /* input variables */
 	    struct
 	    {
 	      u32 next_index;	/* index of next node - used by custom apps */
 	      u32 error_next_index;	/* index of next node if error - used by custom apps */
 	    };
 	    /* handoff variables */
 	    struct
 	    {
 	      u16 owner_thread_index;
 	    };
 	  };
 	  /* output variables */
 	  struct
 	  {
 	    union
 	    {
 	      /* shallow virtual reassembly output variables */
 	      struct
 	      {
 		u16 l4_src_port;	/* tcp/udp/icmp src port */
 		u16 l4_dst_port;	/* tcp/udp/icmp dst port */
 		u32 tcp_ack_number;
 		u8 save_rewrite_length;
 		u8 ip_proto;	/* protocol in ip header */
 		u8 icmp_type_or_tcp_flags;
 		u8 is_non_first_fragment;
 		u32 tcp_seq_number;
 	      };
 	      /* full reassembly output variables */
 	      struct
 	      {
 		u16 estimated_mtu;	/* estimated MTU calculated during reassembly */
 	      };
 	    };
 	  };
 	  /* internal variables used during reassembly */
 	  struct
 	  {
 	    u16 fragment_first;
 	    u16 fragment_last;
 	    u16 range_first;
 	    u16 range_last;
 	    u32 next_range_bi;
 	    u16 ip6_frag_hdr_offset;
 	  };
 	} reass;
       };
     } ip;

     /*
      * MPLS:
      * data copied from the MPLS header that was popped from the packet
      * during the look-up.
      */
     struct
     {
       /* do not overlay w/ ip.adj_index[0,1] nor flow hash */
       u32 pad[VLIB_N_RX_TX + 1];
       u8 ttl;
       u8 exp;
       u8 first;
       u8 pyld_proto:3;		/* dpo_proto_t */
       u8 rsvd:5;
       /* Rewrite length */
       u8 save_rewrite_length;
       /* Save the mpls header length including all label stack */
       u8 mpls_hdr_length;
       /*
        * BIER - the number of bytes in the header.
        *  the len field in the header is not authoritative. It's the
        * value in the table that counts.
        */
       struct
       {
 	u8 n_bytes;
       } bier;
     } mpls;

     /* l2 bridging path, only valid there */
     struct opaque_l2
     {
       u32 feature_bitmap;
       u16 bd_index;		/* bridge-domain index */
       u16 l2fib_sn;		/* l2fib bd/int seq_num */
       u8 l2_len;		/* ethernet header length */
       u8 shg;			/* split-horizon group */
       u8 bd_age;		/* aging enabled */
     } l2;

     /* l2tpv3 softwire encap, only valid there */
     struct
     {
       u32 pad[4];		/* do not overlay w/ ip.adj_index[0,1] */
       u8 next_index;
       u32 session_index;
     } l2t;

     /* L2 classify */
     struct
     {
       struct opaque_l2 pad;
       union
       {
 	u32 table_index;
 	u32 opaque_index;
       };
       u64 hash;
     } l2_classify;

     /* vnet policer */
     struct
     {
       u32 pad[8 - VLIB_N_RX_TX - 1];	/* to end of opaque */
       u32 index;
     } policer;

     /* interface output features */
     struct
     {
       /* don't overlap the adjcencies nor flow-hash */
       u32 __pad[3];
       u32 sad_index;
       u32 protect_index;
       u16 thread_index;
     } ipsec;

     /* MAP */
     struct
     {
       u16 mtu;
     } map;

     /* MAP-T */
     struct
     {
       u32 map_domain_index;
       struct
       {
 	u32 saddr, daddr;
 	u16 frag_offset;	//Fragmentation header offset
 	u16 l4_offset;		//L4 header overall offset
 	u8 l4_protocol;		//The final protocol number
       } v6;			//Used by ip6_map_t only
       u16 checksum_offset;	//L4 checksum overall offset
       u16 mtu;			//Exit MTU
     } map_t;

     /* IP Fragmentation */
     struct
     {
       u32 pad[2];		/* do not overlay w/ ip.adj_index[0,1] */
       u16 mtu;
       u8 next_index;
       u8 flags;			//See ip_frag.h
     } ip_frag;

     /* COP - configurable junk filter(s) */
     struct
     {
       /* Current configuration index. */
       u32 current_config_index;
     } cop;

     /* LISP */
     struct
     {
       /* overlay address family */
       u16 overlay_afi;
     } lisp;

     /* TCP */
     struct
     {
       u32 connection_index;
       union
       {
 	u32 seq_number;
 	u32 next_node_opaque;
       };
       u32 seq_end;
       u32 ack_number;
       u16 hdr_offset;		/**< offset relative to ip hdr */
       u16 data_offset;		/**< offset relative to ip hdr */
       u16 data_len;		/**< data len */
       u8 flags;
     } tcp;

     /* SNAT */
     struct
     {
       u32 flags;
       u32 required_thread_index;
     } snat;

     u32 unused[6];
   };
 } vnet_buffer_opaque_t;

 #define VNET_REWRITE_TOTAL_BYTES (VLIB_BUFFER_PRE_DATA_SIZE)

 STATIC_ASSERT (STRUCT_SIZE_OF (vnet_buffer_opaque_t, ip.save_rewrite_length)
 	       == STRUCT_SIZE_OF (vnet_buffer_opaque_t,
 				  ip.reass.save_rewrite_length)
 	       && STRUCT_SIZE_OF (vnet_buffer_opaque_t,
 				  ip.reass.save_rewrite_length) ==
 	       STRUCT_SIZE_OF (vnet_buffer_opaque_t, mpls.save_rewrite_length)
 	       && STRUCT_SIZE_OF (vnet_buffer_opaque_t,
 				  mpls.save_rewrite_length) == 1
 	       && VNET_REWRITE_TOTAL_BYTES < UINT8_MAX,
 	       "save_rewrite_length member must be able to hold the max value of rewrite length");

 STATIC_ASSERT (STRUCT_OFFSET_OF (vnet_buffer_opaque_t, ip.save_rewrite_length)
 	       == STRUCT_OFFSET_OF (vnet_buffer_opaque_t,
 				    ip.reass.save_rewrite_length)
 	       && STRUCT_OFFSET_OF (vnet_buffer_opaque_t,
 				    mpls.save_rewrite_length) ==
 	       STRUCT_OFFSET_OF (vnet_buffer_opaque_t,
 				 ip.reass.save_rewrite_length),
 	       "save_rewrite_length must be aligned so that reass doesn't overwrite it");

 /*
  * The opaque field of the vlib_buffer_t is interpreted as a
  * vnet_buffer_opaque_t. Hence it should be big enough to accommodate one.
  */
 STATIC_ASSERT (sizeof (vnet_buffer_opaque_t) <=
 	       STRUCT_SIZE_OF (vlib_buffer_t, opaque),
 	       "VNET buffer meta-data too large for vlib_buffer");

 #define vnet_buffer(b) ((vnet_buffer_opaque_t *) (b)->opaque)

 /* Full cache line (64 bytes) of additional space */
 typedef struct
 {
   /**
    * QoS marking data that needs to persist from the recording nodes
    * (nominally in the ingress path) to the marking node (in the
    * egress path)
    */
   struct
   {
     u8 bits;
     u8 source;
   } qos;

   u8 loop_counter;
   u8 __unused[1];

   /* Group Based Policy */
   struct
   {
     u8 __unused;
     u8 flags;
     u16 sclass;
   } gbp;

   /**
    * The L4 payload size set on input on GSO enabled interfaces
    * when we receive a GSO packet (a chain of buffers with the first one
    * having GSO bit set), and needs to persist all the way to the interface-output,
    * in case the egress interface is not GSO-enabled - then we need to perform
    * the segmentation, and use this value to cut the payload appropriately.
    */
   struct
   {
     u16 gso_size;
     /* size of L4 prototol header */
     u16 gso_l4_hdr_sz;
   };

   struct
   {
     u32 arc_next;
     union
     {
       u32 cached_session_index;
       u32 cached_dst_nat_session_index;
     };
   } nat;

   union
   {
     struct
     {
       u64 pad[1];
       u64 pg_replay_timestamp;
     };
     u32 unused[8];
   };
 } vnet_buffer_opaque2_t;

 #define vnet_buffer2(b) ((vnet_buffer_opaque2_t *) (b)->opaque2)

 /*
  * The opaque2 field of the vlib_buffer_t is interpreted as a
  * vnet_buffer_opaque2_t. Hence it should be big enough to accommodate one.
  */
 STATIC_ASSERT (sizeof (vnet_buffer_opaque2_t) <=
 	       STRUCT_SIZE_OF (vlib_buffer_t, opaque2),
 	       "VNET buffer opaque2 meta-data too large for vlib_buffer");

 #define gso_mtu_sz(b) (vnet_buffer2(b)->gso_size + \
                        vnet_buffer2(b)->gso_l4_hdr_sz + \
                        vnet_buffer(b)->l4_hdr_offset - \
                        vnet_buffer (b)->l3_hdr_offset)


 format_function_t format_vnet_buffer;
 format_function_t format_vnet_buffer_offload;
 format_function_t format_vnet_buffer_flags;
 format_function_t format_vnet_buffer_opaque;
 format_function_t format_vnet_buffer_opaque2;

 static_always_inline void
 vnet_buffer_offload_flags_set (vlib_buffer_t *b, vnet_buffer_oflags_t oflags)
 {
   if (b->flags & VNET_BUFFER_F_OFFLOAD)
     {
       /* add a flag to existing offload */
       vnet_buffer (b)->oflags |= oflags;
     }
   else
     {
       /* no offload yet: reset offload flags to new value */
       vnet_buffer (b)->oflags = oflags;
       b->flags |= VNET_BUFFER_F_OFFLOAD;
     }
 }

 static_always_inline void
 vnet_buffer_offload_flags_clear (vlib_buffer_t *b, vnet_buffer_oflags_t oflags)
 {
   vnet_buffer (b)->oflags &= ~oflags;
   if (0 == vnet_buffer (b)->oflags)
     b->flags &= ~VNET_BUFFER_F_OFFLOAD;
 }

 #endif /* included_vnet_buffer_h */

 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	* Copyright (c) 2015 Cisco and/or its affiliates.
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at:
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	/*
	* vnet/buffer.h: vnet buffer flags
	*
	* Copyright (c) 2008 Eliot Dresselhaus
	*
	* Permission is hereby granted, free of charge, to any person obtaining
	* a copy of this software and associated documentation files (the
	* "Software"), to deal in the Software without restriction, including
	* without limitation the rights to use, copy, modify, merge, publish,
	* distribute, sublicense, and/or sell copies of the Software, and to
	* permit persons to whom the Software is furnished to do so, subject to
	* the following conditions:
	*
	* The above copyright notice and this permission notice shall be
	* included in all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
	* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
	* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
	* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
	*/

	#ifndef included_vnet_buffer_h
	#define included_vnet_buffer_h

	#include <vlib/vlib.h>

	/**
	* Flags that are set in the high order bits of ((vlib_buffer*)b)->flags
	*
	*/
	#define foreach_vnet_buffer_flag \
	_ (1, L4_CHECKSUM_COMPUTED, "l4-cksum-computed", 1) \
	_ (2, L4_CHECKSUM_CORRECT, "l4-cksum-correct", 1) \
	_ (3, VLAN_2_DEEP, "vlan-2-deep", 1) \
	_ (4, VLAN_1_DEEP, "vlan-1-deep", 1) \
	_ (5, SPAN_CLONE, "span-clone", 1) \
	_ (6, LOOP_COUNTER_VALID, "loop-counter-valid", 0) \
	_ (7, LOCALLY_ORIGINATED, "local", 1) \
	_ (8, IS_IP4, "ip4", 1) \
	_ (9, IS_IP6, "ip6", 1) \
	_ (10, OFFLOAD, "offload", 0) \
	_ (11, IS_NATED, "natted", 1) \
	_ (12, L2_HDR_OFFSET_VALID, "l2_hdr_offset_valid", 0) \
	_ (13, L3_HDR_OFFSET_VALID, "l3_hdr_offset_valid", 0) \
	_ (14, L4_HDR_OFFSET_VALID, "l4_hdr_offset_valid", 0) \
	_ (15, FLOW_REPORT, "flow-report", 1) \
	_ (16, IS_DVR, "dvr", 1) \
	_ (17, QOS_DATA_VALID, "qos-data-valid", 0) \
	_ (18, GSO, "gso", 0) \
	_ (19, AVAIL1, "avail1", 1) \
	_ (20, AVAIL2, "avail2", 1) \
	_ (21, AVAIL3, "avail3", 1) \
	_ (22, AVAIL4, "avail4", 1) \
	_ (23, AVAIL5, "avail5", 1) \
	_ (24, AVAIL6, "avail6", 1) \
	_ (25, AVAIL7, "avail7", 1) \
	_ (26, AVAIL8, "avail8", 1) \
	_ (27, AVAIL9, "avail9", 1)

	/*
	* Please allocate the FIRST available bit, redefine
	* AVAIL 1 ... AVAILn-1, and remove AVAILn. Please maintain the
	* VNET_BUFFER_FLAGS_ALL_AVAIL definition.
	*/

	#define VNET_BUFFER_FLAGS_ALL_AVAIL \
	(VNET_BUFFER_F_AVAIL1 \| VNET_BUFFER_F_AVAIL2 \| VNET_BUFFER_F_AVAIL3 \| \
	VNET_BUFFER_F_AVAIL4 \| VNET_BUFFER_F_AVAIL5 \| VNET_BUFFER_F_AVAIL6 \| \
	VNET_BUFFER_F_AVAIL7 \| VNET_BUFFER_F_AVAIL8 \| VNET_BUFFER_F_AVAIL9)

	#define VNET_BUFFER_FLAGS_VLAN_BITS \
	(VNET_BUFFER_F_VLAN_1_DEEP \| VNET_BUFFER_F_VLAN_2_DEEP)

	enum
	{
	#define _(bit, name, s, v) VNET_BUFFER_F_##name = (1 << LOG2_VLIB_BUFFER_FLAG_USER(bit)),
	foreach_vnet_buffer_flag
	#undef _
	};

	enum
	{
	#define _(bit, name, s, v) VNET_BUFFER_F_LOG2_##name = LOG2_VLIB_BUFFER_FLAG_USER(bit),
	foreach_vnet_buffer_flag
	#undef _
	};

	/* Make sure that the vnet and vlib bits are disjoint */
	STATIC_ASSERT (((VNET_BUFFER_FLAGS_ALL_AVAIL & VLIB_BUFFER_FLAGS_ALL) == 0),
	"VLIB / VNET buffer flags overlap");

	#define foreach_vnet_buffer_offload_flag \
	_ (0, IP_CKSUM, "offload-ip-cksum", 1) \
	_ (1, TCP_CKSUM, "offload-tcp-cksum", 1) \
	_ (2, UDP_CKSUM, "offload-udp-cksum", 1) \
	_ (3, OUTER_IP_CKSUM, "offload-outer-ip-cksum", 1) \
	_ (4, OUTER_TCP_CKSUM, "offload-outer-tcp-cksum", 1) \
	_ (5, OUTER_UDP_CKSUM, "offload-outer-udp-cksum", 1)

	typedef enum
	{
	#define _(bit, name, s, v) VNET_BUFFER_OFFLOAD_F_##name = (1 << bit),
	foreach_vnet_buffer_offload_flag
	#undef _
	} vnet_buffer_oflags_t;

	#define foreach_buffer_opaque_union_subtype \
	_(ip) \
	_(l2) \
	_(l2t) \
	_(l2_classify) \
	_(policer) \
	_(ipsec) \
	_(map) \
	_(map_t) \
	_(ip_frag) \
	_(mpls) \
	_(tcp)

	/*
	* vnet stack buffer opaque array overlay structure.
	* The vnet_buffer_opaque_t must be the same size as the
	* vlib_buffer_t "opaque" structure member, 32 bytes.
	*
	* When adding a union type, please add a stanza to
	* foreach_buffer_opaque_union_subtype (directly above).
	* Code in vnet_interface_init(...) verifies the size
	* of the union, and will announce any deviations in an
	* impossible-to-miss manner.
	*/
	typedef struct
	{
	u32 sw_if_index[VLIB_N_RX_TX];
	i16 l2_hdr_offset;
	i16 l3_hdr_offset;
	i16 l4_hdr_offset;
	u8 feature_arc_index;
	/* offload flags */
	vnet_buffer_oflags_t oflags : 8;

	union
	{
	/* IP4/6 buffer opaque. */
	struct
	{
	/* Adjacency from destination IP address lookup [VLIB_TX].
	Adjacency from source IP address lookup [VLIB_RX].
	This gets set to ~0 until source lookup is performed. */
	u32 adj_index[VLIB_N_RX_TX];

	union
	{
	struct
	{
	/* Flow hash value for this packet computed from IP src/dst address
	protocol and ports. */
	u32 flow_hash;

	union
	{
	/* next protocol */
	u32 save_protocol;

	/* Hint for transport protocols */
	u32 fib_index;
	};

	/* Rewrite length */
	u8 save_rewrite_length;

	/* MFIB RPF ID */
	u32 rpf_id;
	};

	/* ICMP */
	struct
	{
	u8 type;
	u8 code;
	u32 data;
	} icmp;

	/* reassembly */
	union
	{
	/* group input/output to simplify the code, this way
	* we can handoff while keeping input variables intact */
	struct
	{
	/* input variables */
	struct
	{
	u32 next_index; /* index of next node - used by custom apps */
	u32 error_next_index; /* index of next node if error - used by custom apps */
	};
	/* handoff variables */
	struct
	{
	u16 owner_thread_index;
	};
	};
	/* output variables */
	struct
	{
	union
	{
	/* shallow virtual reassembly output variables */
	struct
	{
	u16 l4_src_port; /* tcp/udp/icmp src port */
	u16 l4_dst_port; /* tcp/udp/icmp dst port */
	u32 tcp_ack_number;
	u8 save_rewrite_length;
	u8 ip_proto; /* protocol in ip header */
	u8 icmp_type_or_tcp_flags;
	u8 is_non_first_fragment;
	u32 tcp_seq_number;
	};
	/* full reassembly output variables */
	struct
	{
	u16 estimated_mtu; /* estimated MTU calculated during reassembly */
	};
	};
	};
	/* internal variables used during reassembly */
	struct
	{
	u16 fragment_first;
	u16 fragment_last;
	u16 range_first;
	u16 range_last;
	u32 next_range_bi;
	u16 ip6_frag_hdr_offset;
	};
	} reass;
	};
	} ip;

	/*
	* MPLS:
	* data copied from the MPLS header that was popped from the packet
	* during the look-up.
	*/
	struct
	{
	/* do not overlay w/ ip.adj_index[0,1] nor flow hash */
	u32 pad[VLIB_N_RX_TX + 1];
	u8 ttl;
	u8 exp;
	u8 first;
	u8 pyld_proto:3; /* dpo_proto_t */
	u8 rsvd:5;
	/* Rewrite length */
	u8 save_rewrite_length;
	/* Save the mpls header length including all label stack */
	u8 mpls_hdr_length;
	/*
	* BIER - the number of bytes in the header.
	* the len field in the header is not authoritative. It's the
	* value in the table that counts.
	*/
	struct
	{
	u8 n_bytes;
	} bier;
	} mpls;

	/* l2 bridging path, only valid there */
	struct opaque_l2
	{
	u32 feature_bitmap;
	u16 bd_index; /* bridge-domain index */
	u16 l2fib_sn; /* l2fib bd/int seq_num */
	u8 l2_len; /* ethernet header length */
	u8 shg; /* split-horizon group */
	u8 bd_age; /* aging enabled */
	} l2;

	/* l2tpv3 softwire encap, only valid there */
	struct
	{
	u32 pad[4]; /* do not overlay w/ ip.adj_index[0,1] */
	u8 next_index;
	u32 session_index;
	} l2t;

	/* L2 classify */
	struct
	{
	struct opaque_l2 pad;
	union
	{
	u32 table_index;
	u32 opaque_index;
	};
	u64 hash;
	} l2_classify;

	/* vnet policer */
	struct
	{
	u32 pad[8 - VLIB_N_RX_TX - 1]; /* to end of opaque */
	u32 index;
	} policer;

	/* interface output features */
	struct
	{
	/* don't overlap the adjcencies nor flow-hash */
	u32 __pad[3];
	u32 sad_index;
	u32 protect_index;
	u16 thread_index;
	} ipsec;

	/* MAP */
	struct
	{
	u16 mtu;
	} map;

	/* MAP-T */
	struct
	{
	u32 map_domain_index;
	struct
	{
	u32 saddr, daddr;
	u16 frag_offset; //Fragmentation header offset
	u16 l4_offset; //L4 header overall offset
	u8 l4_protocol; //The final protocol number
	} v6; //Used by ip6_map_t only
	u16 checksum_offset; //L4 checksum overall offset
	u16 mtu; //Exit MTU
	} map_t;

	/* IP Fragmentation */
	struct
	{
	u32 pad[2]; /* do not overlay w/ ip.adj_index[0,1] */
	u16 mtu;
	u8 next_index;
	u8 flags; //See ip_frag.h
	} ip_frag;

	/* COP - configurable junk filter(s) */
	struct
	{
	/* Current configuration index. */
	u32 current_config_index;
	} cop;

	/* LISP */
	struct
	{
	/* overlay address family */
	u16 overlay_afi;
	} lisp;

	/* TCP */
	struct
	{
	u32 connection_index;
	union
	{
	u32 seq_number;
	u32 next_node_opaque;
	};
	u32 seq_end;
	u32 ack_number;
	u16 hdr_offset; /*< offset relative to ip hdr /
	u16 data_offset; /*< offset relative to ip hdr /
	u16 data_len; /*< data len /
	u8 flags;
	} tcp;

	/* SNAT */
	struct
	{
	u32 flags;
	u32 required_thread_index;
	} snat;

	u32 unused[6];
	};
	} vnet_buffer_opaque_t;

	#define VNET_REWRITE_TOTAL_BYTES (VLIB_BUFFER_PRE_DATA_SIZE)

	STATIC_ASSERT (STRUCT_SIZE_OF (vnet_buffer_opaque_t, ip.save_rewrite_length)
	== STRUCT_SIZE_OF (vnet_buffer_opaque_t,
	ip.reass.save_rewrite_length)
	&& STRUCT_SIZE_OF (vnet_buffer_opaque_t,
	ip.reass.save_rewrite_length) ==
	STRUCT_SIZE_OF (vnet_buffer_opaque_t, mpls.save_rewrite_length)
	&& STRUCT_SIZE_OF (vnet_buffer_opaque_t,
	mpls.save_rewrite_length) == 1
	&& VNET_REWRITE_TOTAL_BYTES < UINT8_MAX,
	"save_rewrite_length member must be able to hold the max value of rewrite length");

	STATIC_ASSERT (STRUCT_OFFSET_OF (vnet_buffer_opaque_t, ip.save_rewrite_length)
	== STRUCT_OFFSET_OF (vnet_buffer_opaque_t,
	ip.reass.save_rewrite_length)
	&& STRUCT_OFFSET_OF (vnet_buffer_opaque_t,
	mpls.save_rewrite_length) ==
	STRUCT_OFFSET_OF (vnet_buffer_opaque_t,
	ip.reass.save_rewrite_length),
	"save_rewrite_length must be aligned so that reass doesn't overwrite it");

	/*
	* The opaque field of the vlib_buffer_t is interpreted as a
	* vnet_buffer_opaque_t. Hence it should be big enough to accommodate one.
	*/
	STATIC_ASSERT (sizeof (vnet_buffer_opaque_t) <=
	STRUCT_SIZE_OF (vlib_buffer_t, opaque),
	"VNET buffer meta-data too large for vlib_buffer");

	#define vnet_buffer(b) ((vnet_buffer_opaque_t *) (b)->opaque)

	/* Full cache line (64 bytes) of additional space */
	typedef struct
	{
	/**
	* QoS marking data that needs to persist from the recording nodes
	* (nominally in the ingress path) to the marking node (in the
	* egress path)
	*/
	struct
	{
	u8 bits;
	u8 source;
	} qos;

	u8 loop_counter;
	u8 __unused[1];

	/* Group Based Policy */
	struct
	{
	u8 __unused;
	u8 flags;
	u16 sclass;
	} gbp;

	/**
	* The L4 payload size set on input on GSO enabled interfaces
	* when we receive a GSO packet (a chain of buffers with the first one
	* having GSO bit set), and needs to persist all the way to the interface-output,
	* in case the egress interface is not GSO-enabled - then we need to perform
	* the segmentation, and use this value to cut the payload appropriately.
	*/
	struct
	{
	u16 gso_size;
	/* size of L4 prototol header */
	u16 gso_l4_hdr_sz;
	};

	struct
	{
	u32 arc_next;
	union
	{
	u32 cached_session_index;
	u32 cached_dst_nat_session_index;
	};
	} nat;

	union
	{
	struct
	{
	u64 pad[1];
	u64 pg_replay_timestamp;
	};
	u32 unused[8];
	};
	} vnet_buffer_opaque2_t;

	#define vnet_buffer2(b) ((vnet_buffer_opaque2_t *) (b)->opaque2)

	/*
	* The opaque2 field of the vlib_buffer_t is interpreted as a
	* vnet_buffer_opaque2_t. Hence it should be big enough to accommodate one.
	*/
	STATIC_ASSERT (sizeof (vnet_buffer_opaque2_t) <=
	STRUCT_SIZE_OF (vlib_buffer_t, opaque2),
	"VNET buffer opaque2 meta-data too large for vlib_buffer");

	#define gso_mtu_sz(b) (vnet_buffer2(b)->gso_size + \
	vnet_buffer2(b)->gso_l4_hdr_sz + \
	vnet_buffer(b)->l4_hdr_offset - \
	vnet_buffer (b)->l3_hdr_offset)


	format_function_t format_vnet_buffer;
	format_function_t format_vnet_buffer_offload;
	format_function_t format_vnet_buffer_flags;
	format_function_t format_vnet_buffer_opaque;
	format_function_t format_vnet_buffer_opaque2;

	static_always_inline void
	vnet_buffer_offload_flags_set (vlib_buffer_t *b, vnet_buffer_oflags_t oflags)
	{
	if (b->flags & VNET_BUFFER_F_OFFLOAD)
	{
	/* add a flag to existing offload */
	vnet_buffer (b)->oflags \|= oflags;
	}
	else
	{
	/* no offload yet: reset offload flags to new value */
	vnet_buffer (b)->oflags = oflags;
	b->flags \|= VNET_BUFFER_F_OFFLOAD;
	}
	}

	static_always_inline void
	vnet_buffer_offload_flags_clear (vlib_buffer_t *b, vnet_buffer_oflags_t oflags)
	{
	vnet_buffer (b)->oflags &= ~oflags;
	if (0 == vnet_buffer (b)->oflags)
	b->flags &= ~VNET_BUFFER_F_OFFLOAD;
	}

	#endif /* included_vnet_buffer_h */

	/*
	* fd.io coding-style-patch-verification: ON
	*
	* Local Variables:
	* eval: (c-set-style "gnu")
	* End:
	*/