buffer.h

Go to the documentation of this file.

/*
 * 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_IP_CKSUM, "offload-ip-cksum", 1)        \
  _(11, OFFLOAD_TCP_CKSUM, "offload-tcp-cksum", 1)      \
  _(12, OFFLOAD_UDP_CKSUM, "offload-udp-cksum", 1)      \
  _(13, IS_NATED, "natted", 1)                          \
  _(14, L2_HDR_OFFSET_VALID, "l2_hdr_offset_valid", 0)  \
  _(15, L3_HDR_OFFSET_VALID, "l3_hdr_offset_valid", 0)  \
  _(16, L4_HDR_OFFSET_VALID, "l4_hdr_offset_valid", 0)  \
  _(17, FLOW_REPORT, "flow-report", 1)                  \
  _(18, IS_DVR, "dvr", 1)                               \
  _(19, QOS_DATA_VALID, "qos-data-valid", 0)            \
  _(20, GSO, "gso", 0)                                  \
  _(21, AVAIL1, "avail1", 1)                            \
  _(22, AVAIL2, "avail2", 1)                            \
  _(23, AVAIL3, "avail3", 1)                            \
  _(24, AVAIL4, "avail4", 1)                            \
  _(25, AVAIL5, "avail5", 1)                            \
  _(26, AVAIL6, "avail6", 1)                            \
  _(27, AVAIL7, "avail7", 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)

#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_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;
  u8 dont_waste_me;

  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
              {
                u8 ip_proto;    /* protocol in ip header */
                u8 icmp_type_or_tcp_flags;
                u8 is_non_first_fragment;
                u8 save_rewrite_length;
                u16 l4_src_port;        /* tcp/udp/icmp src port */
                u16 l4_dst_port;        /* tcp/udp/icmp dst port */
                u32 tcp_ack_number;
                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
    {
      u32 sad_index;
      u32 protect_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;
    } 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");

/*
 * 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.
   */
  u16 gso_size;
  /* size of L4 prototol header */
  u16 gso_l4_hdr_sz;

  /* The union below has a u64 alignment, so this space is unused */
  u32 __unused2[1];

  union
  {
    struct
    {
#if VLIB_BUFFER_TRACE_TRAJECTORY > 0
      /* buffer trajectory tracing */
      u16 *trajectory_trace;
#endif
    };
    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;

#endif /* included_vnet_buffer_h */

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