frr/lib/vrf.c

/*
 * VRF functions.
 * Copyright (C) 2014 6WIND S.A.
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2, or (at your
 * option) any later version.
 *
 * GNU Zebra is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU Zebra; see the file COPYING.  If not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#include <zebra.h>

#include "if.h"
#include "vrf.h"
#include "prefix.h"
#include "table.h"
#include "log.h"
#include "memory.h"

/* Holding VRF hooks  */
struct vrf_master
{
  int (*vrf_new_hook) (vrf_id_t, const char *, void **);
  int (*vrf_delete_hook) (vrf_id_t, const char *, void **);
  int (*vrf_enable_hook) (vrf_id_t, const char *, void **);
  int (*vrf_disable_hook) (vrf_id_t, const char *, void **);
} vrf_master = {0,};

/* VRF table */
struct route_table *vrf_table = NULL;

/* VRF is part of a list too to store it before its actually active */
struct list *vrf_list;

static int vrf_is_enabled (struct vrf *vrf);
static void vrf_disable (struct vrf *vrf);

/* VRF list existance check by name. */
struct vrf *
vrf_list_lookup_by_name (const char *name)
{
  struct listnode *node;
  struct vrf *vrfp;

  if (name)
    for (ALL_LIST_ELEMENTS_RO (vrf_list, node, vrfp))
      {
        if (strcmp(name, vrfp->name) == 0)
          return vrfp;
      }
  return NULL;
}

struct vrf *
vrf_list_lookup_by_name_len (const char *name, size_t namelen)
{
  struct listnode *node;
  struct vrf *vrfp;

  if (namelen > INTERFACE_NAMSIZ)
    return NULL;

  for (ALL_LIST_ELEMENTS_RO (vrf_list, node, vrfp))
    {
      if (!memcmp(name, vrfp->name, namelen) && (vrfp->name[namelen] == '\0'))
	return vrfp;
    }
  return NULL;
}

/* Create new interface structure. */
struct vrf *
vrf_create (const char *name, size_t namelen)
{
  struct vrf *vrfp;

  vrfp = XCALLOC (MTYPE_VRF, sizeof (struct vrf));

  assert (name);
  assert (namelen <= VRF_NAMSIZ);	/* Need space for '\0' at end. */
  strncpy (vrfp->name, name, namelen);
  vrfp->name[namelen] = '\0';
  if (vrf_list_lookup_by_name (vrfp->name) == NULL)
    listnode_add_sort (vrf_list, vrfp);
  else
    zlog_err("vrf_create(%s): corruption detected -- vrf with this "
             "name exists already with vrf-id %u!", vrfp->name, vrfp->vrf_id);

  UNSET_FLAG(vrfp->status, ZEBRA_VRF_ACTIVE);

  /* Pending: - Make sure this 0 vrf-id isnt taken as default vrf
              - See if calling the the new_hook here is ok, may need to make the attached callback re-entrant.
  if (vrf_master.vrf_new_hook)
    (*vrf_master.vrf_new_hook) (0, name, &vrfp->info);
  */
  return vrfp;
}

struct vrf *
vrf_get_by_name_len (const char *name, size_t namelen)
{
  struct vrf *vrfp;

  return ((vrfp = vrf_list_lookup_by_name_len (name, namelen)) != NULL) ? vrfp :
          vrf_create (name, namelen);
}

struct vrf *
vrf_get_by_name (const char *name)
{
  struct vrf *vrfp;

  return ((vrfp = vrf_list_lookup_by_name (name)) != NULL) ? vrfp :
          vrf_create (name, strlen(name));
}

/* Build the table key */
static void
vrf_build_key (vrf_id_t vrf_id, struct prefix *p)
{
  p->family = AF_INET;
  p->prefixlen = IPV4_MAX_BITLEN;
  p->u.prefix4.s_addr = vrf_id;
}

/* Get a VRF. If not found, create one.
 * Arg: name
 * Description: Please note that this routine can be called with just the name
   and 0 vrf-id */
struct vrf *
vrf_get (vrf_id_t vrf_id, const char *name)
{
  struct prefix p;
  struct route_node *rn;
  struct vrf *vrf = NULL;

  vrf_build_key (vrf_id, &p);
  rn = route_node_get (vrf_table, &p);
  if (rn->info)
    {
      vrf = (struct vrf *)rn->info;
      route_unlock_node (rn); /* get */

      if (name)
        {
          strncpy (vrf->name, name, strlen(name));
          vrf->name[strlen(name)] = '\0';
          if (vrf_list_lookup_by_name (vrf->name) == NULL)
            listnode_add_sort (vrf_list, vrf);
        }
    }
  else
    {
      if (name)
        vrf = vrf_get_by_name(name);

      if (!vrf)
        vrf = XCALLOC (MTYPE_VRF, sizeof (struct vrf));

      vrf->vrf_id = vrf_id;
      rn->info = vrf;
      vrf->node = rn;

      /* Initialize interfaces. */
      if_init (vrf_id, &vrf->iflist);
    }

  if (name)
    zlog_info ("VRF %s with id %u is created.", name, vrf_id);
  else
    zlog_info ("VRF %u is created.", vrf_id);

  if (vrf_master.vrf_new_hook && name) {
    (*vrf_master.vrf_new_hook) (vrf_id, name, &vrf->info);

    if (vrf->info)
      zlog_info ("zvrf is created.");
  }
  return vrf;
}

/* Delete a VRF. This is called in vrf_terminate(). */
void
vrf_delete (struct vrf *vrf)
{
  zlog_info ("VRF %u is to be deleted.", vrf->vrf_id);

  if (vrf_is_enabled (vrf))
    vrf_disable (vrf);

  if (vrf_master.vrf_delete_hook)
    (*vrf_master.vrf_delete_hook) (vrf->vrf_id, vrf->name, &vrf->info);

  if (CHECK_FLAG (vrf->status, ZEBRA_VRF_ACTIVE))
    if_terminate (vrf->vrf_id, &vrf->iflist);

  if (vrf->node)
    {
      vrf->node->info = NULL;
      route_unlock_node(vrf->node);
    }

  listnode_delete (vrf_list, vrf);

  XFREE (MTYPE_VRF, vrf);
}

/* Look up a VRF by identifier. */
struct vrf *
vrf_lookup (vrf_id_t vrf_id)
{
  struct prefix p;
  struct route_node *rn;
  struct vrf *vrf = NULL;

  vrf_build_key (vrf_id, &p);
  rn = route_node_lookup (vrf_table, &p);
  if (rn)
    {
      vrf = (struct vrf *)rn->info;
      route_unlock_node (rn); /* lookup */
    }
  return vrf;
}

/*
 * Check whether the VRF is enabled - that is, whether the VRF
 * is ready to allocate resources. Currently there's only one
 * type of resource: socket.
 */
static int
vrf_is_enabled (struct vrf *vrf)
{
  return vrf && CHECK_FLAG (vrf->status, ZEBRA_VRF_ACTIVE);

  /*Pending: figure out the real use of this routine.. it used to be..
  return vrf && vrf->vrf_id == VRF_DEFAULT;
  */
}

/*
 * Enable a VRF - that is, let the VRF be ready to use.
 * The VRF_ENABLE_HOOK callback will be called to inform
 * that they can allocate resources in this VRF.
 *
 * RETURN: 1 - enabled successfully; otherwise, 0.
 */
int
vrf_enable (struct vrf *vrf)
{
//Pending: see if VRF lib had a reason to leave it for default only
// /* Till now, only the default VRF can be enabled. */
//  if (vrf->vrf_id == VRF_DEFAULT)
//    {
      zlog_info ("VRF %u is enabled.", vrf->vrf_id);

      if (vrf_master.vrf_enable_hook)
        (*vrf_master.vrf_enable_hook) (vrf->vrf_id, vrf->name, &vrf->info);

      return 1;
//    }

//  return 0;
}

/*
 * Disable a VRF - that is, let the VRF be unusable.
 * The VRF_DELETE_HOOK callback will be called to inform
 * that they must release the resources in the VRF.
 */
static void
vrf_disable (struct vrf *vrf)
{
  if (vrf_is_enabled (vrf))
    {
      zlog_info ("VRF %u is to be disabled.", vrf->vrf_id);

      /* Till now, nothing to be done for the default VRF. */
      //Pending: see why this statement.

      if (vrf_master.vrf_disable_hook)
        (*vrf_master.vrf_disable_hook) (vrf->vrf_id, vrf->name, &vrf->info);
    }
}


/* Add a VRF hook. Please add hooks before calling vrf_init(). */
void
vrf_add_hook (int type, int (*func)(vrf_id_t, const char *, void **))
{
  switch (type) {
  case VRF_NEW_HOOK:
    vrf_master.vrf_new_hook = func;
    break;
  case VRF_DELETE_HOOK:
    vrf_master.vrf_delete_hook = func;
    break;
  case VRF_ENABLE_HOOK:
    vrf_master.vrf_enable_hook = func;
    break;
  case VRF_DISABLE_HOOK:
    vrf_master.vrf_disable_hook = func;
    break;
  default:
    break;
  }
}

/* Return the iterator of the first VRF. */
vrf_iter_t
vrf_first (void)
{
  struct route_node *rn;

  for (rn = route_top (vrf_table); rn; rn = route_next (rn))
    if (rn->info)
      {
        route_unlock_node (rn); /* top/next */
        return (vrf_iter_t)rn;
      }
  return VRF_ITER_INVALID;
}

/* Return the next VRF iterator to the given iterator. */
vrf_iter_t
vrf_next (vrf_iter_t iter)
{
  struct route_node *rn = NULL;

  /* Lock it first because route_next() will unlock it. */
  if (iter != VRF_ITER_INVALID)
    rn = route_next (route_lock_node ((struct route_node *)iter));

  for (; rn; rn = route_next (rn))
    if (rn->info)
      {
        route_unlock_node (rn); /* next */
        return (vrf_iter_t)rn;
      }
  return VRF_ITER_INVALID;
}

/* Return the VRF iterator of the given VRF ID. If it does not exist,
 * the iterator of the next existing VRF is returned. */
vrf_iter_t
vrf_iterator (vrf_id_t vrf_id)
{
  struct prefix p;
  struct route_node *rn;

  vrf_build_key (vrf_id, &p);
  rn = route_node_get (vrf_table, &p);
  if (rn->info)
    {
      /* OK, the VRF exists. */
      route_unlock_node (rn); /* get */
      return (vrf_iter_t)rn;
    }

  /* Find the next VRF. */
  for (rn = route_next (rn); rn; rn = route_next (rn))
    if (rn->info)
      {
        route_unlock_node (rn); /* next */
        return (vrf_iter_t)rn;
      }

  return VRF_ITER_INVALID;
}

/* Obtain the VRF ID from the given VRF iterator. */
vrf_id_t
vrf_iter2id (vrf_iter_t iter)
{
  struct route_node *rn = (struct route_node *) iter;
  return (rn && rn->info) ? ((struct vrf *)rn->info)->vrf_id : VRF_DEFAULT;
}

struct vrf *
vrf_iter2vrf (vrf_iter_t iter)
{
  struct route_node *rn = (struct route_node *) iter;
  return (rn && rn->info) ? (struct vrf *)rn->info : NULL;
}

/* Obtain the data pointer from the given VRF iterator. */
void *
vrf_iter2info (vrf_iter_t iter)
{
  struct route_node *rn = (struct route_node *) iter;
  return (rn && rn->info) ? ((struct vrf *)rn->info)->info : NULL;
}

/* Obtain the interface list from the given VRF iterator. */
struct list *
vrf_iter2iflist (vrf_iter_t iter)
{
  struct route_node *rn = (struct route_node *) iter;
  return (rn && rn->info) ? ((struct vrf *)rn->info)->iflist : NULL;
}

/* Look up a VRF by name. */
struct vrf *
vrf_lookup_by_name (const char *name)
{
  struct vrf *vrf = NULL;
  vrf_iter_t iter;

  for (iter = vrf_first (); iter != VRF_ITER_INVALID; iter = vrf_next (iter))
    {
      vrf = vrf_iter2vrf (iter);
      if (vrf && !strcmp(vrf->name, name))
        break;
    }

  return vrf;
}

vrf_id_t
vrf_name_to_id (const char *name)
{
  struct vrf *vrf;
  vrf_id_t vrf_id = VRF_DEFAULT; //Pending: need a way to return invalid id/ routine not used.

  vrf = vrf_lookup_by_name (name);
  if (vrf)
    vrf_id = vrf->vrf_id;

  return vrf_id;
}

/* Get the data pointer of the specified VRF. If not found, create one. */
void *
vrf_info_get (vrf_id_t vrf_id)
{
  struct vrf *vrf = vrf_get (vrf_id, NULL);
  return vrf->info;
}

/* Look up the data pointer of the specified VRF. */
void *
vrf_info_lookup (vrf_id_t vrf_id)
{
  struct vrf *vrf = vrf_lookup (vrf_id);
  return vrf ? vrf->info : NULL;
}

/* Look up the interface list in a VRF. */
struct list *
vrf_iflist (vrf_id_t vrf_id)
{
   struct vrf * vrf = vrf_lookup (vrf_id);
   return vrf ? vrf->iflist : NULL;
}

/* Get the interface list of the specified VRF. Create one if not find. */
struct list *
vrf_iflist_get (vrf_id_t vrf_id)
{
   struct vrf * vrf = vrf_get (vrf_id, NULL);
   return vrf->iflist;
}

/*
 * VRF bit-map
 */

#define VRF_BITMAP_NUM_OF_GROUPS            8
#define VRF_BITMAP_NUM_OF_BITS_IN_GROUP \
    (UINT16_MAX / VRF_BITMAP_NUM_OF_GROUPS)
#define VRF_BITMAP_NUM_OF_BYTES_IN_GROUP \
    (VRF_BITMAP_NUM_OF_BITS_IN_GROUP / CHAR_BIT + 1) /* +1 for ensure */

#define VRF_BITMAP_GROUP(_id) \
    ((_id) / VRF_BITMAP_NUM_OF_BITS_IN_GROUP)
#define VRF_BITMAP_BIT_OFFSET(_id) \
    ((_id) % VRF_BITMAP_NUM_OF_BITS_IN_GROUP)

#define VRF_BITMAP_INDEX_IN_GROUP(_bit_offset) \
    ((_bit_offset) / CHAR_BIT)
#define VRF_BITMAP_FLAG(_bit_offset) \
    (((u_char)1) << ((_bit_offset) % CHAR_BIT))

struct vrf_bitmap
{
  u_char *groups[VRF_BITMAP_NUM_OF_GROUPS];
};

vrf_bitmap_t
vrf_bitmap_init (void)
{
  return (vrf_bitmap_t) XCALLOC (MTYPE_VRF_BITMAP, sizeof (struct vrf_bitmap));
}

void
vrf_bitmap_free (vrf_bitmap_t bmap)
{
  struct vrf_bitmap *bm = (struct vrf_bitmap *) bmap;
  int i;

  if (bmap == VRF_BITMAP_NULL)
    return;

  for (i = 0; i < VRF_BITMAP_NUM_OF_GROUPS; i++)
    if (bm->groups[i])
      XFREE (MTYPE_VRF_BITMAP, bm->groups[i]);

  XFREE (MTYPE_VRF_BITMAP, bm);
}

void
vrf_bitmap_set (vrf_bitmap_t bmap, vrf_id_t vrf_id)
{
  struct vrf_bitmap *bm = (struct vrf_bitmap *) bmap;
  u_char group = VRF_BITMAP_GROUP (vrf_id);
  u_char offset = VRF_BITMAP_BIT_OFFSET (vrf_id);

  if (bmap == VRF_BITMAP_NULL)
    return;

  if (bm->groups[group] == NULL)
    bm->groups[group] = XCALLOC (MTYPE_VRF_BITMAP,
                                 VRF_BITMAP_NUM_OF_BYTES_IN_GROUP);

  SET_FLAG (bm->groups[group][VRF_BITMAP_INDEX_IN_GROUP (offset)],
            VRF_BITMAP_FLAG (offset));
}

void
vrf_bitmap_unset (vrf_bitmap_t bmap, vrf_id_t vrf_id)
{
  struct vrf_bitmap *bm = (struct vrf_bitmap *) bmap;
  u_char group = VRF_BITMAP_GROUP (vrf_id);
  u_char offset = VRF_BITMAP_BIT_OFFSET (vrf_id);

  if (bmap == VRF_BITMAP_NULL || bm->groups[group] == NULL)
    return;

  UNSET_FLAG (bm->groups[group][VRF_BITMAP_INDEX_IN_GROUP (offset)],
              VRF_BITMAP_FLAG (offset));
}

int
vrf_bitmap_check (vrf_bitmap_t bmap, vrf_id_t vrf_id)
{
  struct vrf_bitmap *bm = (struct vrf_bitmap *) bmap;
  u_char group = VRF_BITMAP_GROUP (vrf_id);
  u_char offset = VRF_BITMAP_BIT_OFFSET (vrf_id);

  if (bmap == VRF_BITMAP_NULL || bm->groups[group] == NULL)
    return 0;

  return CHECK_FLAG (bm->groups[group][VRF_BITMAP_INDEX_IN_GROUP (offset)],
                     VRF_BITMAP_FLAG (offset)) ? 1 : 0;
}

//Pending: See if combining the common parts with if_cmp_func() make sense.
/* Compare interface names, returning an integer greater than, equal to, or
 * less than 0, (following the strcmp convention), according to the
 * relationship between vrfp1 and vrfp2.  Interface names consist of an
 * alphabetic prefix and a numeric suffix.  The primary sort key is
 * lexicographic by name, and then numeric by number.  No number sorts
 * before all numbers.  Examples: de0 < de1, de100 < fxp0 < xl0, devpty <
 * devpty0, de0 < del0
 */
int
vrf_cmp_func (struct vrf *vrfp1, struct vrf *vrfp2)
{
  unsigned int l1, l2;
  long int x1, x2;
  char *p1, *p2;
  int res;

  p1 = vrfp1->name;
  p2 = vrfp2->name;

  while (*p1 && *p2) {
    /* look up to any number */
    l1 = strcspn(p1, "0123456789");
    l2 = strcspn(p2, "0123456789");

    /* name lengths are different -> compare names */
    if (l1 != l2)
      return (strcmp(p1, p2));

    /* Note that this relies on all numbers being less than all letters, so
     * that de0 < del0.
     */
    res = strncmp(p1, p2, l1);

    /* names are different -> compare them */
    if (res)
      return res;

    /* with identical name part, go to numeric part */
    p1 += l1;
    p2 += l1;

    if (!*p1)
      return -1;
    if (!*p2)
      return 1;

    x1 = strtol(p1, &p1, 10);
    x2 = strtol(p2, &p2, 10);

    /* let's compare numbers now */
    if (x1 < x2)
      return -1;
    if (x1 > x2)
      return 1;

    /* numbers were equal, lets do it again..
    (it happens with name like "eth123.456:789") */
  }
  if (*p1)
    return 1;
  if (*p2)
    return -1;
  return 0;
}

/* Initialize VRF module. */
void
vrf_init (void)
{
  struct vrf *default_vrf;

  vrf_list = list_new ();
  vrf_list->cmp = (int (*)(void *, void *))vrf_cmp_func;

  /* Allocate VRF table.  */
  vrf_table = route_table_init ();

  /* The default VRF always exists. */
  default_vrf = vrf_get (VRF_DEFAULT, VRF_DEFAULT_NAME);
  if (!default_vrf)
    {
      zlog_err ("vrf_init: failed to create the default VRF!");
      exit (1);
    }

  /* Enable the default VRF. */
  if (!vrf_enable (default_vrf))
    {
      zlog_err ("vrf_init: failed to enable the default VRF!");
      exit (1);
    }
}

/* Terminate VRF module. */
void
vrf_terminate (void)
{
  struct route_node *rn;
  struct vrf *vrf;

  for (rn = route_top (vrf_table); rn; rn = route_next (rn))
    if ((vrf = rn->info) != NULL)
      vrf_delete (vrf);

  route_table_finish (vrf_table);
  vrf_table = NULL;
}

/* Create a socket for the VRF. */
int
vrf_socket (int domain, int type, int protocol, vrf_id_t vrf_id)
{
  int ret = -1;

    ret = socket (domain, type, protocol);

  return ret;
}