sr_localsid.c

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/*
 * sr_localsid.c: ipv6 segment routing Endpoint behaviors
 *
 * Copyright (c) 2016 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.
 */

/**
 * @file
 * @brief Processing of packets with a SRH
 *
 * CLI to define new Segment Routing End processing functions.
 * Graph node to support such functions.
 *
 * Each function associates an SRv6 segment (IPv6 address) with an specific
 * Segment Routing function.
 *
 */

#include <vlib/vlib.h>
#include <vnet/vnet.h>
#include <vnet/sr/sr.h>
#include <vnet/ip/ip.h>
#include <vnet/sr/sr_packet.h>
#include <vnet/ip/ip6_packet.h>
#include <vnet/fib/ip6_fib.h>
#include <vnet/dpo/dpo.h>
#include <vnet/adj/adj.h>

#include <vppinfra/error.h>
#include <vppinfra/elog.h>

/**
 * @brief Dynamically added SR localsid DPO type
 */
static dpo_type_t sr_localsid_dpo_type;
static dpo_type_t sr_localsid_d_dpo_type;

/**
 * @brief SR localsid add/del
 *
 * Function to add or delete SR LocalSIDs.
 *
 * @param is_del Boolean of whether its a delete instruction
 * @param localsid_addr IPv6 address of the localsid
 * @param is_decap Boolean of whether decapsulation is allowed in this function
 * @param behavior Type of behavior (function) for this localsid
 * @param sw_if_index Only for L2/L3 xconnect. OIF. In VRF variant the fib_table.
 * @param vlan_index Only for L2 xconnect. Outgoing VLAN tag.
 * @param fib_table  FIB table in which we should install the localsid entry
 * @param nh_addr Next Hop IPv4/IPv6 address. Only for L2/L3 xconnect.
 *
 * @return 0 on success, error otherwise.
 */
int
sr_cli_localsid (char is_del, ip6_address_t * localsid_addr,
                 char end_psp, u8 behavior, u32 sw_if_index, u32 vlan_index,
                 u32 fib_table, ip46_address_t * nh_addr, void *ls_plugin_mem)
{
  ip6_sr_main_t *sm = &sr_main;
  uword *p;
  int rv;

  ip6_sr_localsid_t *ls = 0;

  dpo_id_t dpo = DPO_INVALID;

  /* Search for the item */
  p = mhash_get (&sm->sr_localsids_index_hash, localsid_addr);

  if (p)
    {
      if (is_del)
        {
          /* Retrieve localsid */
          ls = pool_elt_at_index (sm->localsids, p[0]);
          /* Delete FIB entry */
          fib_prefix_t pfx = {
            .fp_proto = FIB_PROTOCOL_IP6,
            .fp_len = 128,
            .fp_addr = {
                        .ip6 = *localsid_addr,
                        }
          };

          fib_table_entry_delete (fib_table_id_find_fib_index
                                  (FIB_PROTOCOL_IP6, fib_table), &pfx,
                                  FIB_SOURCE_SR);

          /* In case it is a Xconnect iface remove the (OIF, NHOP) adj */
          if (ls->behavior == SR_BEHAVIOR_X || ls->behavior == SR_BEHAVIOR_DX6
              || ls->behavior == SR_BEHAVIOR_DX4)
            adj_unlock (ls->nh_adj);

          if (ls->behavior >= SR_BEHAVIOR_LAST)
            {
              sr_localsid_fn_registration_t *plugin = 0;
              plugin = pool_elt_at_index (sm->plugin_functions,
                                          ls->behavior - SR_BEHAVIOR_LAST);

              /* Callback plugin removal function */
              rv = plugin->removal (ls);
            }

          /* Delete localsid registry */
          pool_put (sm->localsids, ls);
          mhash_unset (&sm->sr_localsids_index_hash, localsid_addr, NULL);
          return 1;
        }
      else                      /* create with function already existing; complain */
        return -1;
    }
  else
    /* delete; localsid does not exist; complain */
  if (is_del)
    return -2;

  /* Check whether there exists a FIB entry with such address */
  fib_prefix_t pfx = {
    .fp_proto = FIB_PROTOCOL_IP6,
    .fp_len = 128,
  };

  pfx.fp_addr.as_u64[0] = localsid_addr->as_u64[0];
  pfx.fp_addr.as_u64[1] = localsid_addr->as_u64[1];

  /* Lookup the FIB index associated to the table id provided */
  u32 fib_index = fib_table_id_find_fib_index (FIB_PROTOCOL_IP6, fib_table);
  if (fib_index == ~0)
    return -3;

  /* Lookup the localsid in such FIB table */
  fib_node_index_t fei = fib_table_lookup_exact_match (fib_index, &pfx);
  if (FIB_NODE_INDEX_INVALID != fei)
    return -4;                  //There is an entry for such address (the localsid addr)

  /* Create a new localsid registry */
  pool_get (sm->localsids, ls);
  memset (ls, 0, sizeof (*ls));

  clib_memcpy (&ls->localsid, localsid_addr, sizeof (ip6_address_t));
  ls->end_psp = end_psp;
  ls->behavior = behavior;
  ls->nh_adj = (u32) ~ 0;
  ls->fib_table = fib_table;
  switch (behavior)
    {
    case SR_BEHAVIOR_END:
      break;
    case SR_BEHAVIOR_X:
      ls->sw_if_index = sw_if_index;
      clib_memcpy (&ls->next_hop.ip6, &nh_addr->ip6, sizeof (ip6_address_t));
      break;
    case SR_BEHAVIOR_DX4:
      ls->sw_if_index = sw_if_index;
      clib_memcpy (&ls->next_hop.ip4, &nh_addr->ip4, sizeof (ip4_address_t));
      break;
    case SR_BEHAVIOR_DX6:
      ls->sw_if_index = sw_if_index;
      clib_memcpy (&ls->next_hop.ip6, &nh_addr->ip6, sizeof (ip6_address_t));
      break;
    case SR_BEHAVIOR_DT6:
      ls->vrf_index = sw_if_index;
      break;
    case SR_BEHAVIOR_DX2:
      ls->sw_if_index = sw_if_index;
      ls->vlan_index = vlan_index;
      break;
    }

  /* Figure out the adjacency magic for Xconnect variants */
  if (ls->behavior == SR_BEHAVIOR_X || ls->behavior == SR_BEHAVIOR_DX4
      || ls->behavior == SR_BEHAVIOR_DX6)
    {
      adj_index_t nh_adj_index = ADJ_INDEX_INVALID;

      /* Retrieve the adjacency corresponding to the (OIF, next_hop) */
      if (ls->behavior == SR_BEHAVIOR_DX6 || ls->behavior == SR_BEHAVIOR_X)
        nh_adj_index = adj_nbr_add_or_lock (FIB_PROTOCOL_IP6, VNET_LINK_IP6,
                                            nh_addr, sw_if_index);

      else if (ls->behavior == SR_BEHAVIOR_DX4)
        nh_adj_index = adj_nbr_add_or_lock (FIB_PROTOCOL_IP4, VNET_LINK_IP4,
                                            nh_addr, sw_if_index);

      /* Check for ADJ creation error. If so panic */
      if (nh_adj_index == ADJ_INDEX_INVALID)
        {
          pool_put (sm->localsids, ls);
          return -5;
        }

      ls->nh_adj = nh_adj_index;
    }

  /* Set DPO */
  if (ls->behavior == SR_BEHAVIOR_END || ls->behavior == SR_BEHAVIOR_X)
    dpo_set (&dpo, sr_localsid_dpo_type, DPO_PROTO_IP6, ls - sm->localsids);
  else if (ls->behavior > SR_BEHAVIOR_D_FIRST
           && ls->behavior < SR_BEHAVIOR_LAST)
    dpo_set (&dpo, sr_localsid_d_dpo_type, DPO_PROTO_IP6, ls - sm->localsids);
  else if (ls->behavior >= SR_BEHAVIOR_LAST)
    {
      sr_localsid_fn_registration_t *plugin = 0;
      plugin = pool_elt_at_index (sm->plugin_functions,
                                  ls->behavior - SR_BEHAVIOR_LAST);
      /* Copy the unformat memory result */
      ls->plugin_mem = ls_plugin_mem;
      /* Callback plugin creation function */
      rv = plugin->creation (ls);
      if (rv)
        {
          pool_put (sm->localsids, ls);
          return -6;
        }
      dpo_set (&dpo, plugin->dpo, DPO_PROTO_IP6, ls - sm->localsids);
    }

  /* Set hash key for searching localsid by address */
  mhash_set (&sm->sr_localsids_index_hash, localsid_addr, ls - sm->localsids,
             NULL);

  fib_table_entry_special_dpo_add (fib_index, &pfx, FIB_SOURCE_SR,
                                   FIB_ENTRY_FLAG_EXCLUSIVE, &dpo);
  dpo_reset (&dpo);

  /* Set counter to zero */
  vlib_validate_combined_counter (&(sm->sr_ls_valid_counters),
                                  ls - sm->localsids);
  vlib_validate_combined_counter (&(sm->sr_ls_invalid_counters),
                                  ls - sm->localsids);

  vlib_zero_combined_counter (&(sm->sr_ls_valid_counters),
                              ls - sm->localsids);
  vlib_zero_combined_counter (&(sm->sr_ls_invalid_counters),
                              ls - sm->localsids);

  return 0;
}

/**
 * @brief SR LocalSID CLI function.
 *
 * @see sr_cli_localsid
 */
static clib_error_t *
sr_cli_localsid_command_fn (vlib_main_t * vm, unformat_input_t * input,
                            vlib_cli_command_t * cmd)
{
  vnet_main_t *vnm = vnet_get_main ();
  ip6_sr_main_t *sm = &sr_main;
  u32 sw_if_index = (u32) ~ 0, vlan_index = (u32) ~ 0, fib_index = 0;
  int is_del = 0;
  int end_psp = 0;
  ip6_address_t resulting_address;
  ip46_address_t next_hop;
  char address_set = 0;
  char behavior = 0;
  void *ls_plugin_mem = 0;

  int rv;

  memset (&resulting_address, 0, sizeof (ip6_address_t));
  ip46_address_reset (&next_hop);

  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (input, "del"))
        is_del = 1;
      else if (!address_set
               && unformat (input, "address %U", unformat_ip6_address,
                            &resulting_address))
        address_set = 1;
      else if (!address_set
               && unformat (input, "addr %U", unformat_ip6_address,
                            &resulting_address))
        address_set = 1;
      else if (unformat (input, "fib-table %u", &fib_index));
      else if (vlan_index == (u32) ~ 0
               && unformat (input, "vlan %u", &vlan_index));
      else if (!behavior && unformat (input, "behavior"))
        {
          if (unformat (input, "end.x %U %U",
                        unformat_vnet_sw_interface, vnm, &sw_if_index,
                        unformat_ip6_address, &next_hop.ip6))
            behavior = SR_BEHAVIOR_X;
          else if (unformat (input, "end.dx6 %U %U",
                             unformat_vnet_sw_interface, vnm, &sw_if_index,
                             unformat_ip6_address, &next_hop.ip6))
            behavior = SR_BEHAVIOR_DX6;
          else if (unformat (input, "end.dx4 %U %U",
                             unformat_vnet_sw_interface, vnm, &sw_if_index,
                             unformat_ip4_address, &next_hop.ip4))
            behavior = SR_BEHAVIOR_DX4;
          else if (unformat (input, "end.dx2 %U",
                             unformat_vnet_sw_interface, vnm, &sw_if_index))
            behavior = SR_BEHAVIOR_DX2;
          else if (unformat (input, "end.dt6 %u", &sw_if_index))
            behavior = SR_BEHAVIOR_DT6;
          else if (unformat (input, "end.dt4 %u", &sw_if_index))
            behavior = SR_BEHAVIOR_DT4;
          else
            {
              /* Loop over all the plugin behavior format functions */
              sr_localsid_fn_registration_t *plugin = 0, **vec_plugins = 0;
              sr_localsid_fn_registration_t **plugin_it = 0;

              /* Create a vector out of the plugin pool as recommended */
        /* *INDENT-OFF* */
        pool_foreach (plugin, sm->plugin_functions,
        {
          vec_add1 (vec_plugins, plugin);
        });
        /* *INDENT-ON* */

              vec_foreach (plugin_it, vec_plugins)
              {
                if (unformat
                    (input, "%U", (*plugin_it)->ls_unformat, &ls_plugin_mem))
                  {
                    behavior = (*plugin_it)->sr_localsid_function_number;
                    break;
                  }
              }
            }

          if (!behavior)
            {
              if (unformat (input, "end"))
                behavior = SR_BEHAVIOR_END;
              else
                break;
            }
        }
      else if (!end_psp && unformat (input, "psp"))
        end_psp = 1;
      else
        break;
    }

  if (!behavior && end_psp)
    behavior = SR_BEHAVIOR_END;

  if (!address_set)
    return clib_error_return (0,
                              "Error: SRv6 LocalSID address is mandatory.");
  if (!is_del && !behavior)
    return clib_error_return (0,
                              "Error: SRv6 LocalSID behavior is mandatory.");
  if (vlan_index != (u32) ~ 0)
    return clib_error_return (0,
                              "Error: SRv6 End.DX2 with rewrite VLAN tag not supported by now.");
  if (end_psp && !(behavior == SR_BEHAVIOR_END || behavior == SR_BEHAVIOR_X))
    return clib_error_return (0,
                              "Error: SRv6 PSP only compatible with End and End.X");

  rv = sr_cli_localsid (is_del, &resulting_address, end_psp, behavior,
                        sw_if_index, vlan_index, fib_index, &next_hop,
                        ls_plugin_mem);

  switch (rv)
    {
    case 0:
      break;
    case 1:
      return 0;
    case -1:
      return clib_error_return (0,
                                "Identical localsid already exists. Requested localsid not created.");
    case -2:
      return clib_error_return (0,
                                "The requested localsid could not be deleted. SR localsid not found");
    case -3:
      return clib_error_return (0, "FIB table %u does not exist", fib_index);
    case -4:
      return clib_error_return (0, "There is already one FIB entry for the"
                                "requested localsid non segment routing related");
    case -5:
      return clib_error_return (0,
                                "Could not create ARP/ND entry for such next_hop. Internal error.");
    case -6:
      return clib_error_return (0,
                                "Error on the plugin based localsid creation.");
    default:
      return clib_error_return (0, "BUG: sr localsid returns %d", rv);
    }
  return 0;
}

/* *INDENT-OFF* */
VLIB_CLI_COMMAND (sr_localsid_command, static) = {
  .path = "sr localsid",
  .short_help = "sr localsid (del) address XX:XX::YY:YY"
      "(fib-table 8) behavior STRING",
  .long_help =
    "Create SR LocalSID and binds it to a particular behavior\n"
    "Arguments:\n"
    "\tlocalSID IPv6_addr(128b)   LocalSID IPv6 address\n"
    "\t(fib-table X)              Optional. VRF where to install SRv6 localsid\n"
    "\tbehavior STRING            Specifies the behavior\n"
    "\n\tBehaviors:\n"
    "\tEnd\t-> Endpoint.\n"
    "\tEnd.X\t-> Endpoint with decapsulation and Layer-3 cross-connect.\n"
    "\t\tParameters: '<iface> <ip6_next_hop>'\n"
    "\tEnd.DX2\t-> Endpoint with decapsulation and Layer-2 cross-connect.\n"
    "\t\tParameters: '<iface>'\n"
    "\tEnd.DX6\t-> Endpoint with decapsulation and IPv6 cross-connect.\n"
    "\t\tParameters: '<iface> <ip6_next_hop>'\n"
    "\tEnd.DX4\t-> Endpoint with decapsulation and IPv4 cross-connect.\n"
    "\t\tParameters: '<iface> <ip4_next_hop>'\n"
    "\tEnd.DT6\t-> Endpoint with decapsulation and specific IPv6 table lookup.\n"
    "\t\tParameters: '<ip6_fib_table>'\n"
    "\tEnd.DT4\t-> Endpoint with decapsulation and specific IPv4 table lookup.\n"
    "\t\tParameters: '<ip4_fib_table>'\n",
  .function = sr_cli_localsid_command_fn,
};
/* *INDENT-ON* */

/**
 * @brief CLI function to 'show' all SR LocalSIDs on console.
 */
static clib_error_t *
show_sr_localsid_command_fn (vlib_main_t * vm, unformat_input_t * input,
                             vlib_cli_command_t * cmd)
{
  vnet_main_t *vnm = vnet_get_main ();
  ip6_sr_main_t *sm = &sr_main;
  ip6_sr_localsid_t **localsid_list = 0;
  ip6_sr_localsid_t *ls;
  int i;

  vlib_cli_output (vm, "SRv6 - My LocalSID Table:");
  vlib_cli_output (vm, "=========================");
  /* *INDENT-OFF* */
  pool_foreach (ls, sm->localsids, ({ vec_add1 (localsid_list, ls); }));
  /* *INDENT-ON* */
  for (i = 0; i < vec_len (localsid_list); i++)
    {
      ls = localsid_list[i];
      switch (ls->behavior)
        {
        case SR_BEHAVIOR_END:
          vlib_cli_output (vm, "\tAddress: \t%U\n\tBehavior: \tEnd",
                           format_ip6_address, &ls->localsid);
          break;
        case SR_BEHAVIOR_X:
          vlib_cli_output (vm,
                           "\tAddress: \t%U\n\tBehavior: \tX (Endpoint with Layer-3 cross-connect)"
                           "\n\tIface:  \t%U\n\tNext hop: \t%U",
                           format_ip6_address, &ls->localsid,
                           format_vnet_sw_if_index_name, vnm, ls->sw_if_index,
                           format_ip6_address, &ls->next_hop.ip6);
          break;
        case SR_BEHAVIOR_DX4:
          vlib_cli_output (vm,
                           "\tAddress: \t%U\n\tBehavior: \tDX4 (Endpoint with decapsulation and IPv4 cross-connect)"
                           "\n\tIface:  \t%U\n\tNext hop: \t%U",
                           format_ip6_address, &ls->localsid,
                           format_vnet_sw_if_index_name, vnm, ls->sw_if_index,
                           format_ip4_address, &ls->next_hop.ip4);
          break;
        case SR_BEHAVIOR_DX6:
          vlib_cli_output (vm,
                           "\tAddress: \t%U\n\tBehavior: \tDX6 (Endpoint with decapsulation and IPv6 cross-connect)"
                           "\n\tIface:  \t%U\n\tNext hop: \t%U",
                           format_ip6_address, &ls->localsid,
                           format_vnet_sw_if_index_name, vnm, ls->sw_if_index,
                           format_ip6_address, &ls->next_hop.ip6);
          break;
        case SR_BEHAVIOR_DX2:
          if (ls->vlan_index == (u32) ~ 0)
            vlib_cli_output (vm,
                             "\tAddress: \t%U\n\tBehavior: \tDX2 (Endpoint with decapulation and Layer-2 cross-connect)"
                             "\n\tIface:  \t%U", format_ip6_address,
                             &ls->localsid, format_vnet_sw_if_index_name, vnm,
                             ls->sw_if_index);
          else
            vlib_cli_output (vm,
                             "Unsupported yet. (DX2 with egress VLAN rewrite)");
          break;
        case SR_BEHAVIOR_DT6:
          vlib_cli_output (vm,
                           "\tAddress: \t%U\n\tBehavior: \tDT6 (Endpoint with decapsulation and specific IPv6 table lookup)"
                           "\n\tTable: %u", format_ip6_address, &ls->localsid,
                           ls->fib_table);
          break;
        case SR_BEHAVIOR_DT4:
          vlib_cli_output (vm,
                           "\tAddress: \t%U\n\tBehavior: \tDT4 (Endpoint with decapsulation and specific IPv4 table lookup)"
                           "\n\tTable: \t%u", format_ip6_address,
                           &ls->localsid, ls->fib_table);
          break;
        default:
          if (ls->behavior >= SR_BEHAVIOR_LAST)
            {
              sr_localsid_fn_registration_t *plugin =
                pool_elt_at_index (sm->plugin_functions,
                                   ls->behavior - SR_BEHAVIOR_LAST);

              vlib_cli_output (vm, "\tAddress: \t%U\n"
                               "\tBehavior: \t%s (%s)\n\t%U",
                               format_ip6_address, &ls->localsid,
                               plugin->keyword_str, plugin->def_str,
                               plugin->ls_format, ls->plugin_mem);
            }
          else
            //Should never get here...
            vlib_cli_output (vm, "Internal error");
          break;
        }
      if (ls->end_psp)
        vlib_cli_output (vm, "\tPSP: \tTrue\n");

      /* Print counters */
      vlib_counter_t valid, invalid;
      vlib_get_combined_counter (&(sm->sr_ls_valid_counters), i, &valid);
      vlib_get_combined_counter (&(sm->sr_ls_invalid_counters), i, &invalid);
      vlib_cli_output (vm, "\tGood traffic: \t[%Ld packets : %Ld bytes]\n",
                       valid.packets, valid.bytes);
      vlib_cli_output (vm, "\tBad traffic:  \t[%Ld packets : %Ld bytes]\n",
                       invalid.packets, invalid.bytes);
      vlib_cli_output (vm, "--------------------");
    }
  return 0;
}

/* *INDENT-OFF* */
VLIB_CLI_COMMAND (show_sr_localsid_command, static) = {
  .path = "show sr localsids",
  .short_help = "show sr localsids",
  .function = show_sr_localsid_command_fn,
};
/* *INDENT-ON* */

/**
 * @brief Function to 'clear' ALL SR localsid counters
 */
static clib_error_t *
clear_sr_localsid_counters_command_fn (vlib_main_t * vm,
                                       unformat_input_t * input,
                                       vlib_cli_command_t * cmd)
{
  ip6_sr_main_t *sm = &sr_main;

  vlib_clear_combined_counters (&(sm->sr_ls_valid_counters));
  vlib_clear_combined_counters (&(sm->sr_ls_invalid_counters));

  return 0;
}

/* *INDENT-OFF* */
VLIB_CLI_COMMAND (clear_sr_localsid_counters_command, static) = {
  .path = "clear sr localsid counters",
  .short_help = "clear sr localsid counters",
  .function = clear_sr_localsid_counters_command_fn,
};
/* *INDENT-ON* */

/************************ SR LocalSID graphs node ****************************/
/**
 * @brief SR localsid node trace
 */
typedef struct
{
  u32 localsid_index;
  ip6_address_t src, out_dst;
  u8 sr[256];
  u8 num_segments;
  u8 segments_left;
  //With SRv6 header update include flags here.
} sr_localsid_trace_t;

#define foreach_sr_localsid_error                                   \
_(NO_INNER_HEADER, "(SR-Error) No inner IP header")                 \
_(NO_MORE_SEGMENTS, "(SR-Error) No more segments")                  \
_(NO_SRH, "(SR-Error) No SR header")                                \
_(NO_PSP, "(SR-Error) PSP Not available (segments left > 0)")       \
_(NOT_LS, "(SR-Error) Decaps not available (segments left > 0)")    \
_(L2, "(SR-Error) SRv6 decapsulated a L2 frame without dest")

typedef enum
{
#define _(sym,str) SR_LOCALSID_ERROR_##sym,
  foreach_sr_localsid_error
#undef _
    SR_LOCALSID_N_ERROR,
} sr_localsid_error_t;

static char *sr_localsid_error_strings[] = {
#define _(sym,string) string,
  foreach_sr_localsid_error
#undef _
};

#define foreach_sr_localsid_next        \
_(ERROR, "error-drop")                  \
_(IP6_LOOKUP, "ip6-lookup")             \
_(IP4_LOOKUP, "ip4-lookup")             \
_(IP6_REWRITE, "ip6-rewrite")           \
_(IP4_REWRITE, "ip4-rewrite")           \
_(INTERFACE_OUTPUT, "interface-output")

typedef enum
{
#define _(s,n) SR_LOCALSID_NEXT_##s,
  foreach_sr_localsid_next
#undef _
    SR_LOCALSID_N_NEXT,
} sr_localsid_next_t;

/**
 * @brief SR LocalSID graph node trace function
 *
 * @see sr_localsid
 */
u8 *
format_sr_localsid_trace (u8 * s, va_list * args)
{
  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  ip6_sr_main_t *sm = &sr_main;
  sr_localsid_trace_t *t = va_arg (*args, sr_localsid_trace_t *);

  ip6_sr_localsid_t *ls =
    pool_elt_at_index (sm->localsids, t->localsid_index);

  s =
    format (s, "SR-LOCALSID:\n\tLocalsid: %U\n", format_ip6_address,
            &ls->localsid);
  switch (ls->behavior)
    {
    case SR_BEHAVIOR_END:
      s = format (s, "\tBehavior: End\n");
      break;
    case SR_BEHAVIOR_DX6:
      s = format (s, "\tBehavior: Decapsulation with IPv6 L3 xconnect\n");
      break;
    case SR_BEHAVIOR_DX4:
      s = format (s, "\tBehavior: Decapsulation with IPv4 L3 xconnect\n");
      break;
    case SR_BEHAVIOR_X:
      s = format (s, "\tBehavior: IPv6 L3 xconnect\n");
      break;
    case SR_BEHAVIOR_DT6:
      s = format (s, "\tBehavior: Decapsulation with IPv6 Table lookup\n");
      break;
    case SR_BEHAVIOR_DT4:
      s = format (s, "\tBehavior: Decapsulation with IPv4 Table lookup\n");
      break;
    case SR_BEHAVIOR_DX2:
      s = format (s, "\tBehavior: Decapsulation with L2 xconnect\n");
      break;
    default:
      s = format (s, "\tBehavior: defined in plugin\n");        //TODO
      break;
    }
  if (t->num_segments != 0xFF)
    {
      if (t->num_segments > 0)
        {
          s = format (s, "\tSegments left: %d\n", t->num_segments);
          s = format (s, "\tSID list: [in ietf order]");
          int i = 0;
          for (i = 0; i < t->num_segments; i++)
            {
              s = format (s, "\n\t-> %U", format_ip6_address,
                          (ip6_address_t *) & t->sr[i *
                                                    sizeof (ip6_address_t)]);
            }
        }
    }
  return s;
}

/**
 * @brief Function doing End processing.
 */
static_always_inline void
end_srh_processing (vlib_node_runtime_t * node,
                    vlib_buffer_t * b0,
                    ip6_header_t * ip0,
                    ip6_sr_header_t * sr0,
                    ip6_sr_localsid_t * ls0, u32 * next0)
{
  ip6_address_t *new_dst0;

  if (PREDICT_TRUE (sr0->type == ROUTING_HEADER_TYPE_SR))
    {
      if (PREDICT_TRUE (sr0->segments_left != 0))
        {
          sr0->segments_left -= 1;
          new_dst0 = (ip6_address_t *) (sr0->segments);
          new_dst0 += sr0->segments_left;
          ip0->dst_address.as_u64[0] = new_dst0->as_u64[0];
          ip0->dst_address.as_u64[1] = new_dst0->as_u64[1];

          if (ls0->behavior == SR_BEHAVIOR_X)
            {
              vnet_buffer (b0)->ip.adj_index[VLIB_TX] = ls0->nh_adj;
              *next0 = SR_LOCALSID_NEXT_IP6_REWRITE;
            }
        }
      else
        {
          *next0 = SR_LOCALSID_NEXT_ERROR;
          b0->error = node->errors[SR_LOCALSID_ERROR_NO_MORE_SEGMENTS];
        }
    }
  else
    {
      /* Error. Routing header of type != SR */
      *next0 = SR_LOCALSID_NEXT_ERROR;
      b0->error = node->errors[SR_LOCALSID_ERROR_NO_SRH];
    }
}

/*
 * @brief Function doing SRH processing for D* variants
 */
//FixME. I must crosscheck that next_proto matches the localsid
static_always_inline void
end_decaps_srh_processing (vlib_node_runtime_t * node,
                           vlib_buffer_t * b0,
                           ip6_header_t * ip0,
                           ip6_sr_header_t * sr0,
                           ip6_sr_localsid_t * ls0, u32 * next0)
{
  /* Compute the size of the IPv6 header with all Ext. headers */
  u8 next_proto;
  ip6_ext_header_t *next_ext_header;
  u16 total_size = 0;

  next_proto = ip0->protocol;
  next_ext_header = (void *) (ip0 + 1);
  total_size = sizeof (ip6_header_t);
  while (ip6_ext_hdr (next_proto))
    {
      total_size += ip6_ext_header_len (next_ext_header);
      next_proto = next_ext_header->next_hdr;
      next_ext_header = ip6_ext_next_header (next_ext_header);
    }

  /* Ensure this is the last segment. Otherwise drop. */
  if (sr0 && sr0->segments_left != 0)
    {
      *next0 = SR_LOCALSID_NEXT_ERROR;
      b0->error = node->errors[SR_LOCALSID_ERROR_NOT_LS];
      return;
    }

  switch (next_proto)
    {
    case IP_PROTOCOL_IPV6:
      /* Encap-End IPv6. Pop outer IPv6 header. */
      if (ls0->behavior == SR_BEHAVIOR_DX6)
        {
          vlib_buffer_advance (b0, total_size);
          vnet_buffer (b0)->ip.adj_index[VLIB_TX] = ls0->nh_adj;
          *next0 = SR_LOCALSID_NEXT_IP6_REWRITE;
          return;
        }
      else if (ls0->behavior == SR_BEHAVIOR_DT6)
        {
          vlib_buffer_advance (b0, total_size);
          vnet_buffer (b0)->sw_if_index[VLIB_TX] = ls0->fib_table;
          return;
        }
      break;
    case IP_PROTOCOL_IP_IN_IP:
      /* Encap-End IPv4. Pop outer IPv6 header */
      if (ls0->behavior == SR_BEHAVIOR_DX4)
        {
          vlib_buffer_advance (b0, total_size);
          vnet_buffer (b0)->ip.adj_index[VLIB_TX] = ls0->nh_adj;
          *next0 = SR_LOCALSID_NEXT_IP4_REWRITE;
          return;
        }
      else if (ls0->behavior == SR_BEHAVIOR_DT4)
        {
          vlib_buffer_advance (b0, total_size);
          vnet_buffer (b0)->sw_if_index[VLIB_TX] = ls0->fib_table;
          *next0 = SR_LOCALSID_NEXT_IP4_LOOKUP;
          return;
        }
      break;
    case IP_PROTOCOL_IP6_NONXT:
      /* L2 encaps */
      if (ls0->behavior == SR_BEHAVIOR_DX2)
        {
          vlib_buffer_advance (b0, total_size);
          vnet_buffer (b0)->sw_if_index[VLIB_TX] = ls0->sw_if_index;
          *next0 = SR_LOCALSID_NEXT_INTERFACE_OUTPUT;
          return;
        }
      break;
    }
  *next0 = SR_LOCALSID_NEXT_ERROR;
  b0->error = node->errors[SR_LOCALSID_ERROR_NO_INNER_HEADER];
  return;
}

/**
 * @brief Function doing End processing with PSP
 */
static_always_inline void
end_psp_srh_processing (vlib_node_runtime_t * node,
                        vlib_buffer_t * b0,
                        ip6_header_t * ip0,
                        ip6_ext_header_t * prev0,
                        ip6_sr_header_t * sr0,
                        ip6_sr_localsid_t * ls0, u32 * next0)
{
  u32 new_l0, sr_len;
  u64 *copy_dst0, *copy_src0;
  u32 copy_len_u64s0 = 0;
  int i;

  if (PREDICT_TRUE (sr0->type == ROUTING_HEADER_TYPE_SR))
    {
      if (PREDICT_TRUE (sr0->segments_left == 1))
        {
          ip0->dst_address.as_u64[0] = sr0->segments->as_u64[0];
          ip0->dst_address.as_u64[1] = sr0->segments->as_u64[1];

          /* Remove the SRH taking care of the rest of IPv6 ext header */
          if (prev0)
            prev0->next_hdr = sr0->protocol;
          else
            ip0->protocol = sr0->protocol;

          sr_len = ip6_ext_header_len (sr0);
          vlib_buffer_advance (b0, sr_len);
          new_l0 = clib_net_to_host_u16 (ip0->payload_length) - sr_len;
          ip0->payload_length = clib_host_to_net_u16 (new_l0);
          copy_src0 = (u64 *) ip0;
          copy_dst0 = copy_src0 + (sr0->length + 1);
          /* number of 8 octet units to copy
           * By default in absence of extension headers it is equal to length of ip6 header
           * With extension headers it number of 8 octet units of ext headers preceding
           * SR header
           */
          copy_len_u64s0 =
            (((u8 *) sr0 - (u8 *) ip0) - sizeof (ip6_header_t)) >> 3;
          copy_dst0[4 + copy_len_u64s0] = copy_src0[4 + copy_len_u64s0];
          copy_dst0[3 + copy_len_u64s0] = copy_src0[3 + copy_len_u64s0];
          copy_dst0[2 + copy_len_u64s0] = copy_src0[2 + copy_len_u64s0];
          copy_dst0[1 + copy_len_u64s0] = copy_src0[1 + copy_len_u64s0];
          copy_dst0[0 + copy_len_u64s0] = copy_src0[0 + copy_len_u64s0];

          for (i = copy_len_u64s0 - 1; i >= 0; i--)
            {
              copy_dst0[i] = copy_src0[i];
            }

          if (ls0->behavior == SR_BEHAVIOR_X)
            {
              vnet_buffer (b0)->ip.adj_index[VLIB_TX] = ls0->nh_adj;
              *next0 = SR_LOCALSID_NEXT_IP6_REWRITE;
            }
          return;
        }
    }
  /* Error. Routing header of type != SR */
  *next0 = SR_LOCALSID_NEXT_ERROR;
  b0->error = node->errors[SR_LOCALSID_ERROR_NO_PSP];
}

/**
 * @brief SR LocalSID graph node. Supports all default SR Endpoint variants
 */
static uword
sr_localsid_d_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
                  vlib_frame_t * from_frame)
{
  u32 n_left_from, next_index, *from, *to_next;
  ip6_sr_main_t *sm = &sr_main;
  from = vlib_frame_vector_args (from_frame);
  n_left_from = from_frame->n_vectors;
  next_index = node->cached_next_index;
  u32 cpu_index = os_get_cpu_number ();

  while (n_left_from > 0)
    {
      u32 n_left_to_next;
      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      /* Quad - Loop */
      while (n_left_from >= 8 && n_left_to_next >= 4)
        {
          u32 bi0, bi1, bi2, bi3;
          vlib_buffer_t *b0, *b1, *b2, *b3;
          ip6_header_t *ip0, *ip1, *ip2, *ip3;
          ip6_ext_header_t *prev0, *prev1, *prev2, *prev3;
          ip6_sr_header_t *sr0, *sr1, *sr2, *sr3;
          u32 next0, next1, next2, next3;
          next0 = next1 = next2 = next3 = SR_LOCALSID_NEXT_IP6_LOOKUP;
          ip6_sr_localsid_t *ls0, *ls1, *ls2, *ls3;

          /* Prefetch next iteration. */
          {
            vlib_buffer_t *p4, *p5, *p6, *p7;

            p4 = vlib_get_buffer (vm, from[4]);
            p5 = vlib_get_buffer (vm, from[5]);
            p6 = vlib_get_buffer (vm, from[6]);
            p7 = vlib_get_buffer (vm, from[7]);

            /* Prefetch the buffer header and packet for the N+4 loop iteration */
            vlib_prefetch_buffer_header (p4, LOAD);
            vlib_prefetch_buffer_header (p5, LOAD);
            vlib_prefetch_buffer_header (p6, LOAD);
            vlib_prefetch_buffer_header (p7, LOAD);

            CLIB_PREFETCH (p4->data, CLIB_CACHE_LINE_BYTES, STORE);
            CLIB_PREFETCH (p5->data, CLIB_CACHE_LINE_BYTES, STORE);
            CLIB_PREFETCH (p6->data, CLIB_CACHE_LINE_BYTES, STORE);
            CLIB_PREFETCH (p7->data, CLIB_CACHE_LINE_BYTES, STORE);
          }

          to_next[0] = bi0 = from[0];
          to_next[1] = bi1 = from[1];
          to_next[2] = bi2 = from[2];
          to_next[3] = bi3 = from[3];
          from += 4;
          to_next += 4;
          n_left_from -= 4;
          n_left_to_next -= 4;

          b0 = vlib_get_buffer (vm, bi0);
          b1 = vlib_get_buffer (vm, bi1);
          b2 = vlib_get_buffer (vm, bi2);
          b3 = vlib_get_buffer (vm, bi3);

          ls0 =
            pool_elt_at_index (sm->localsids,
                               vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
          ls1 =
            pool_elt_at_index (sm->localsids,
                               vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
          ls2 =
            pool_elt_at_index (sm->localsids,
                               vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
          ls3 =
            pool_elt_at_index (sm->localsids,
                               vnet_buffer (b0)->ip.adj_index[VLIB_TX]);

          ip0 = vlib_buffer_get_current (b0);
          ip1 = vlib_buffer_get_current (b1);
          ip2 = vlib_buffer_get_current (b2);
          ip3 = vlib_buffer_get_current (b3);

          ip6_ext_header_find_t (ip0, prev0, sr0, IP_PROTOCOL_IPV6_ROUTE);
          ip6_ext_header_find_t (ip1, prev1, sr1, IP_PROTOCOL_IPV6_ROUTE);
          ip6_ext_header_find_t (ip2, prev2, sr2, IP_PROTOCOL_IPV6_ROUTE);
          ip6_ext_header_find_t (ip3, prev3, sr3, IP_PROTOCOL_IPV6_ROUTE);

          end_decaps_srh_processing (node, b0, ip0, sr0, ls0, &next0);
          end_decaps_srh_processing (node, b1, ip1, sr1, ls1, &next1);
          end_decaps_srh_processing (node, b2, ip2, sr2, ls2, &next2);
          end_decaps_srh_processing (node, b3, ip3, sr3, ls3, &next3);

          //TODO: trace.

          vlib_increment_combined_counter
            (((next0 ==
               SR_LOCALSID_NEXT_ERROR) ? &(sm->sr_ls_invalid_counters) :
              &(sm->sr_ls_valid_counters)), cpu_index, ls0 - sm->localsids, 1,
             vlib_buffer_length_in_chain (vm, b0));

          vlib_increment_combined_counter
            (((next1 ==
               SR_LOCALSID_NEXT_ERROR) ? &(sm->sr_ls_invalid_counters) :
              &(sm->sr_ls_valid_counters)), cpu_index, ls1 - sm->localsids, 1,
             vlib_buffer_length_in_chain (vm, b1));

          vlib_increment_combined_counter
            (((next2 ==
               SR_LOCALSID_NEXT_ERROR) ? &(sm->sr_ls_invalid_counters) :
              &(sm->sr_ls_valid_counters)), cpu_index, ls2 - sm->localsids, 1,
             vlib_buffer_length_in_chain (vm, b2));

          vlib_increment_combined_counter
            (((next3 ==
               SR_LOCALSID_NEXT_ERROR) ? &(sm->sr_ls_invalid_counters) :
              &(sm->sr_ls_valid_counters)), cpu_index, ls3 - sm->localsids, 1,
             vlib_buffer_length_in_chain (vm, b3));

          vlib_validate_buffer_enqueue_x4 (vm, node, next_index, to_next,
                                           n_left_to_next, bi0, bi1, bi2, bi3,
                                           next0, next1, next2, next3);
        }

      /* Single loop for potentially the last three packets */
      while (n_left_from > 0 && n_left_to_next > 0)
        {
          u32 bi0;
          vlib_buffer_t *b0;
          ip6_header_t *ip0;
          ip6_ext_header_t *prev0;
          ip6_sr_header_t *sr0;
          u32 next0 = SR_LOCALSID_NEXT_IP6_LOOKUP;
          ip6_sr_localsid_t *ls0;

          bi0 = from[0];
          to_next[0] = bi0;
          from += 1;
          to_next += 1;
          n_left_from -= 1;
          n_left_to_next -= 1;

          b0 = vlib_get_buffer (vm, bi0);
          ip0 = vlib_buffer_get_current (b0);

          /* Lookup the SR End behavior based on IP DA (adj) */
          ls0 =
            pool_elt_at_index (sm->localsids,
                               vnet_buffer (b0)->ip.adj_index[VLIB_TX]);

          /* Find SRH as well as previous header */
          ip6_ext_header_find_t (ip0, prev0, sr0, IP_PROTOCOL_IPV6_ROUTE);

          /* SRH processing and End variants */
          end_decaps_srh_processing (node, b0, ip0, sr0, ls0, &next0);

          if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
            {
              sr_localsid_trace_t *tr =
                vlib_add_trace (vm, node, b0, sizeof (*tr));
              tr->num_segments = 0;
              tr->localsid_index = ls0 - sm->localsids;

              if (ip0 == vlib_buffer_get_current (b0))
                {
                  clib_memcpy (tr->src.as_u8, ip0->src_address.as_u8,
                               sizeof (tr->src.as_u8));
                  clib_memcpy (tr->out_dst.as_u8, ip0->dst_address.as_u8,
                               sizeof (tr->out_dst.as_u8));
                  if (ip0->protocol == IP_PROTOCOL_IPV6_ROUTE
                      && sr0->type == ROUTING_HEADER_TYPE_SR)
                    {
                      clib_memcpy (tr->sr, sr0->segments, sr0->length * 8);
                      tr->num_segments =
                        sr0->length * 8 / sizeof (ip6_address_t);
                      tr->segments_left = sr0->segments_left;
                    }
                }
              else
                tr->num_segments = 0xFF;
            }

          /* Increase the counters */
          vlib_increment_combined_counter
            (((next0 ==
               SR_LOCALSID_NEXT_ERROR) ? &(sm->sr_ls_invalid_counters) :
              &(sm->sr_ls_valid_counters)), cpu_index, ls0 - sm->localsids, 1,
             vlib_buffer_length_in_chain (vm, b0));

          vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
                                           n_left_to_next, bi0, next0);
        }
      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }
  return from_frame->n_vectors;
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (sr_localsid_d_node) = {
  .function = sr_localsid_d_fn,
  .name = "sr-localsid-d",
  .vector_size = sizeof (u32),
  .format_trace = format_sr_localsid_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,
  .n_errors = SR_LOCALSID_N_ERROR,
  .error_strings = sr_localsid_error_strings,
  .n_next_nodes = SR_LOCALSID_N_NEXT,
  .next_nodes = {
#define _(s,n) [SR_LOCALSID_NEXT_##s] = n,
    foreach_sr_localsid_next
#undef _
  },
};
/* *INDENT-ON* */

/**
 * @brief SR LocalSID graph node. Supports all default SR Endpoint variants
 */
static uword
sr_localsid_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
                vlib_frame_t * from_frame)
{
  u32 n_left_from, next_index, *from, *to_next;
  ip6_sr_main_t *sm = &sr_main;
  from = vlib_frame_vector_args (from_frame);
  n_left_from = from_frame->n_vectors;
  next_index = node->cached_next_index;
  u32 cpu_index = os_get_cpu_number ();

  while (n_left_from > 0)
    {
      u32 n_left_to_next;
      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      /* Quad - Loop */
      while (n_left_from >= 8 && n_left_to_next >= 4)
        {
          u32 bi0, bi1, bi2, bi3;
          vlib_buffer_t *b0, *b1, *b2, *b3;
          ip6_header_t *ip0, *ip1, *ip2, *ip3;
          ip6_sr_header_t *sr0, *sr1, *sr2, *sr3;
          ip6_ext_header_t *prev0, *prev1, *prev2, *prev3;
          u32 next0, next1, next2, next3;
          next0 = next1 = next2 = next3 = SR_LOCALSID_NEXT_IP6_LOOKUP;
          ip6_sr_localsid_t *ls0, *ls1, *ls2, *ls3;

          /* Prefetch next iteration. */
          {
            vlib_buffer_t *p4, *p5, *p6, *p7;

            p4 = vlib_get_buffer (vm, from[4]);
            p5 = vlib_get_buffer (vm, from[5]);
            p6 = vlib_get_buffer (vm, from[6]);
            p7 = vlib_get_buffer (vm, from[7]);

            /* Prefetch the buffer header and packet for the N+2 loop iteration */
            vlib_prefetch_buffer_header (p4, LOAD);
            vlib_prefetch_buffer_header (p5, LOAD);
            vlib_prefetch_buffer_header (p6, LOAD);
            vlib_prefetch_buffer_header (p7, LOAD);

            CLIB_PREFETCH (p4->data, CLIB_CACHE_LINE_BYTES, STORE);
            CLIB_PREFETCH (p5->data, CLIB_CACHE_LINE_BYTES, STORE);
            CLIB_PREFETCH (p6->data, CLIB_CACHE_LINE_BYTES, STORE);
            CLIB_PREFETCH (p7->data, CLIB_CACHE_LINE_BYTES, STORE);
          }

          to_next[0] = bi0 = from[0];
          to_next[1] = bi1 = from[1];
          to_next[2] = bi2 = from[2];
          to_next[3] = bi3 = from[3];
          from += 4;
          to_next += 4;
          n_left_from -= 4;
          n_left_to_next -= 4;

          b0 = vlib_get_buffer (vm, bi0);
          b1 = vlib_get_buffer (vm, bi1);
          b2 = vlib_get_buffer (vm, bi2);
          b3 = vlib_get_buffer (vm, bi3);

          ip0 = vlib_buffer_get_current (b0);
          ip1 = vlib_buffer_get_current (b1);
          ip2 = vlib_buffer_get_current (b2);
          ip3 = vlib_buffer_get_current (b3);

          ip6_ext_header_find_t (ip0, prev0, sr0, IP_PROTOCOL_IPV6_ROUTE);
          ip6_ext_header_find_t (ip1, prev1, sr1, IP_PROTOCOL_IPV6_ROUTE);
          ip6_ext_header_find_t (ip2, prev2, sr2, IP_PROTOCOL_IPV6_ROUTE);
          ip6_ext_header_find_t (ip3, prev3, sr3, IP_PROTOCOL_IPV6_ROUTE);

          ls0 =
            pool_elt_at_index (sm->localsids,
                               vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
          ls1 =
            pool_elt_at_index (sm->localsids,
                               vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
          ls2 =
            pool_elt_at_index (sm->localsids,
                               vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
          ls3 =
            pool_elt_at_index (sm->localsids,
                               vnet_buffer (b0)->ip.adj_index[VLIB_TX]);

          if (ls0->end_psp)
            end_psp_srh_processing (node, b0, ip0, prev0, sr0, ls0, &next0);
          else
            end_srh_processing (node, b0, ip0, sr0, ls0, &next0);

          if (ls1->end_psp)
            end_psp_srh_processing (node, b1, ip1, prev1, sr1, ls1, &next1);
          else
            end_srh_processing (node, b1, ip1, sr1, ls1, &next1);

          if (ls2->end_psp)
            end_psp_srh_processing (node, b2, ip2, prev2, sr2, ls2, &next2);
          else
            end_srh_processing (node, b2, ip2, sr2, ls2, &next2);

          if (ls3->end_psp)
            end_psp_srh_processing (node, b3, ip3, prev3, sr3, ls3, &next3);
          else
            end_srh_processing (node, b3, ip3, sr3, ls3, &next3);

          //TODO: proper trace.

          vlib_increment_combined_counter
            (((next0 ==
               SR_LOCALSID_NEXT_ERROR) ? &(sm->sr_ls_invalid_counters) :
              &(sm->sr_ls_valid_counters)), cpu_index, ls0 - sm->localsids, 1,
             vlib_buffer_length_in_chain (vm, b0));

          vlib_increment_combined_counter
            (((next1 ==
               SR_LOCALSID_NEXT_ERROR) ? &(sm->sr_ls_invalid_counters) :
              &(sm->sr_ls_valid_counters)), cpu_index, ls1 - sm->localsids, 1,
             vlib_buffer_length_in_chain (vm, b1));

          vlib_increment_combined_counter
            (((next2 ==
               SR_LOCALSID_NEXT_ERROR) ? &(sm->sr_ls_invalid_counters) :
              &(sm->sr_ls_valid_counters)), cpu_index, ls2 - sm->localsids, 1,
             vlib_buffer_length_in_chain (vm, b2));

          vlib_increment_combined_counter
            (((next3 ==
               SR_LOCALSID_NEXT_ERROR) ? &(sm->sr_ls_invalid_counters) :
              &(sm->sr_ls_valid_counters)), cpu_index, ls3 - sm->localsids, 1,
             vlib_buffer_length_in_chain (vm, b3));

          vlib_validate_buffer_enqueue_x4 (vm, node, next_index, to_next,
                                           n_left_to_next, bi0, bi1, bi2, bi3,
                                           next0, next1, next2, next3);
        }

      /* Single loop for potentially the last three packets */
      while (n_left_from > 0 && n_left_to_next > 0)
        {
          u32 bi0;
          vlib_buffer_t *b0;
          ip6_header_t *ip0 = 0;
          ip6_ext_header_t *prev0;
          ip6_sr_header_t *sr0;
          u32 next0 = SR_LOCALSID_NEXT_IP6_LOOKUP;
          ip6_sr_localsid_t *ls0;

          bi0 = from[0];
          to_next[0] = bi0;
          from += 1;
          to_next += 1;
          n_left_from -= 1;
          n_left_to_next -= 1;

          b0 = vlib_get_buffer (vm, bi0);
          ip0 = vlib_buffer_get_current (b0);
          ip6_ext_header_find_t (ip0, prev0, sr0, IP_PROTOCOL_IPV6_ROUTE);

          /* Lookup the SR End behavior based on IP DA (adj) */
          ls0 =
            pool_elt_at_index (sm->localsids,
                               vnet_buffer (b0)->ip.adj_index[VLIB_TX]);

          /* SRH processing */
          if (ls0->end_psp)
            end_psp_srh_processing (node, b0, ip0, prev0, sr0, ls0, &next0);
          else
            end_srh_processing (node, b0, ip0, sr0, ls0, &next0);

          if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
            {
              sr_localsid_trace_t *tr =
                vlib_add_trace (vm, node, b0, sizeof (*tr));
              tr->num_segments = 0;
              tr->localsid_index = ls0 - sm->localsids;

              if (ip0 == vlib_buffer_get_current (b0))
                {
                  clib_memcpy (tr->src.as_u8, ip0->src_address.as_u8,
                               sizeof (tr->src.as_u8));
                  clib_memcpy (tr->out_dst.as_u8, ip0->dst_address.as_u8,
                               sizeof (tr->out_dst.as_u8));
                  if (ip0->protocol == IP_PROTOCOL_IPV6_ROUTE
                      && sr0->type == ROUTING_HEADER_TYPE_SR)
                    {
                      clib_memcpy (tr->sr, sr0->segments, sr0->length * 8);
                      tr->num_segments =
                        sr0->length * 8 / sizeof (ip6_address_t);
                      tr->segments_left = sr0->segments_left;
                    }
                }
              else
                {
                  tr->num_segments = 0xFF;
                }
            }

          vlib_increment_combined_counter
            (((next0 ==
               SR_LOCALSID_NEXT_ERROR) ? &(sm->sr_ls_invalid_counters) :
              &(sm->sr_ls_valid_counters)), cpu_index, ls0 - sm->localsids, 1,
             vlib_buffer_length_in_chain (vm, b0));

          vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
                                           n_left_to_next, bi0, next0);
        }
      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }
  return from_frame->n_vectors;
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (sr_localsid_node) = {
  .function = sr_localsid_fn,
  .name = "sr-localsid",
  .vector_size = sizeof (u32),
  .format_trace = format_sr_localsid_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,
  .n_errors = SR_LOCALSID_N_ERROR,
  .error_strings = sr_localsid_error_strings,
  .n_next_nodes = SR_LOCALSID_N_NEXT,
  .next_nodes = {
#define _(s,n) [SR_LOCALSID_NEXT_##s] = n,
    foreach_sr_localsid_next
#undef _
  },
};
/* *INDENT-ON* */

static u8 *
format_sr_dpo (u8 * s, va_list * args)
{
  index_t index = va_arg (*args, index_t);
  CLIB_UNUSED (u32 indent) = va_arg (*args, u32);

  return (format (s, "SR: localsid_index:[%d]", index));
}

const static dpo_vft_t sr_loc_vft = {
  .dv_lock = sr_dpo_lock,
  .dv_unlock = sr_dpo_unlock,
  .dv_format = format_sr_dpo,
};

const static char *const sr_loc_ip6_nodes[] = {
  "sr-localsid",
  NULL,
};

const static char *const *const sr_loc_nodes[DPO_PROTO_NUM] = {
  [DPO_PROTO_IP6] = sr_loc_ip6_nodes,
};

const static char *const sr_loc_d_ip6_nodes[] = {
  "sr-localsid-d",
  NULL,
};

const static char *const *const sr_loc_d_nodes[DPO_PROTO_NUM] = {
  [DPO_PROTO_IP6] = sr_loc_d_ip6_nodes,
};


/*************************** SR LocalSID plugins ******************************/
/**
 * @brief SR LocalSID plugin registry
 */
int
sr_localsid_register_function (vlib_main_t * vm, u8 * fn_name,
                               u8 * keyword_str, u8 * def_str,
                               u8 * params_str, dpo_type_t * dpo,
                               format_function_t * ls_format,
                               unformat_function_t * ls_unformat,
                               sr_plugin_callback_t * creation_fn,
                               sr_plugin_callback_t * removal_fn)
{
  ip6_sr_main_t *sm = &sr_main;
  uword *p;

  sr_localsid_fn_registration_t *plugin;

  /* Did this function exist? If so update it */
  p = hash_get_mem (sm->plugin_functions_by_key, fn_name);
  if (p)
    {
      plugin = pool_elt_at_index (sm->plugin_functions, p[0]);
    }
  /* Else create a new one and set hash key */
  else
    {
      pool_get (sm->plugin_functions, plugin);
      hash_set_mem (sm->plugin_functions_by_key, fn_name,
                    plugin - sm->plugin_functions);
    }

  memset (plugin, 0, sizeof (*plugin));

  plugin->sr_localsid_function_number = (plugin - sm->plugin_functions);
  plugin->sr_localsid_function_number += SR_BEHAVIOR_LAST;
  plugin->ls_format = ls_format;
  plugin->ls_unformat = ls_unformat;
  plugin->creation = creation_fn;
  plugin->removal = removal_fn;
  clib_memcpy (&plugin->dpo, dpo, sizeof (dpo_type_t));
  plugin->function_name = format (0, "%s%c", fn_name, 0);
  plugin->keyword_str = format (0, "%s%c", keyword_str, 0);
  plugin->def_str = format (0, "%s%c", def_str, 0);
  plugin->params_str = format (0, "%s%c", params_str, 0);

  return plugin->sr_localsid_function_number;
}

/**
 * @brief CLI function to 'show' all available SR LocalSID behaviors
 */
static clib_error_t *
show_sr_localsid_behaviors_command_fn (vlib_main_t * vm,
                                       unformat_input_t * input,
                                       vlib_cli_command_t * cmd)
{
  ip6_sr_main_t *sm = &sr_main;
  sr_localsid_fn_registration_t *plugin;
  sr_localsid_fn_registration_t **plugins_vec = 0;
  int i;

  vlib_cli_output (vm,
                   "SR LocalSIDs behaviors:\n-----------------------\n\n");

  /* *INDENT-OFF* */
  pool_foreach (plugin, sm->plugin_functions,
    ({ vec_add1 (plugins_vec, plugin); }));
  /* *INDENT-ON* */

  /* Print static behaviors */
  vlib_cli_output (vm, "Default behaviors:\n"
                   "\tEnd\t-> Endpoint.\n"
                   "\tEnd.X\t-> Endpoint with decapsulation and Layer-3 cross-connect.\n"
                   "\t\tParameters: '<iface> <ip6_next_hop>'\n"
                   "\tEnd.DX2\t-> Endpoint with decapsulation and Layer-2 cross-connect.\n"
                   "\t\tParameters: '<iface>'\n"
                   "\tEnd.DX6\t-> Endpoint with decapsulation and IPv6 cross-connect.\n"
                   "\t\tParameters: '<iface> <ip6_next_hop>'\n"
                   "\tEnd.DX4\t-> Endpoint with decapsulation and IPv4 cross-connect.\n"
                   "\t\tParameters: '<iface> <ip4_next_hop>'\n"
                   "\tEnd.DT6\t-> Endpoint with decapsulation and specific IPv6 table lookup.\n"
                   "\t\tParameters: '<ip6_fib_table>'\n"
                   "\tEnd.DT4\t-> Endpoint with decapsulation and specific IPv4 table lookup.\n"
                   "\t\tParameters: '<ip4_fib_table>'\n");
  vlib_cli_output (vm, "Plugin behaviors:\n");
  for (i = 0; i < vec_len (plugins_vec); i++)
    {
      plugin = plugins_vec[i];
      vlib_cli_output (vm, "\t%s\t-> %s.\n", plugin->keyword_str,
                       plugin->def_str);
      vlib_cli_output (vm, "\t\tParameters: '%s'\n", plugin->params_str);
    }
  return 0;
}

/* *INDENT-OFF* */
VLIB_CLI_COMMAND (show_sr_localsid_behaviors_command, static) = {
  .path = "show sr localsids behaviors",
  .short_help = "show sr localsids behaviors",
  .function = show_sr_localsid_behaviors_command_fn,
};
/* *INDENT-ON* */

/**
 * @brief SR LocalSID initialization
 */
clib_error_t *
sr_localsids_init (vlib_main_t * vm)
{
  /* Init memory for function keys */
  ip6_sr_main_t *sm = &sr_main;
  mhash_init (&sm->sr_localsids_index_hash, sizeof (uword),
              sizeof (ip6_address_t));
  /* Init SR behaviors DPO type */
  sr_localsid_dpo_type = dpo_register_new_type (&sr_loc_vft, sr_loc_nodes);
  /* Init SR behaviors DPO type */
  sr_localsid_d_dpo_type =
    dpo_register_new_type (&sr_loc_vft, sr_loc_d_nodes);
  /* Init memory for localsid plugins */
  sm->plugin_functions_by_key = hash_create_string (0, sizeof (uword));
  return 0;
}

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