mirror_frr/pimd/pim_ssm.c

/*
 * IP SSM ranges for FRR
 * Copyright (C) 2017 Cumulus Networks, Inc.
 *
 * This program 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 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; see the file COPYING; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
 * MA 02110-1301 USA
 */

#include <zebra.h>

#include <lib/linklist.h>
#include <lib/prefix.h>
#include <lib/vty.h>
#include <lib/vrf.h>
#include <lib/plist.h>

#include "pimd.h"
#include "pim_ssm.h"
#include "pim_zebra.h"

static void
pim_ssm_range_reevaluate (void)
{
  /* 1. Setup register state for (S,G) entries if G has changed from SSM to
   *    ASM.
   * 2. check existing (*,G) IGMP registrations to see if they are
   * still ASM. if they are now SSM delete them.
   * 3. Allow channel setup for IGMP (*,G) members if G is now ASM
   * 4. I could tear down all (*,G), (S,G,rpt) states. But that is an
   * unnecessary sladge hammer and may not be particularly useful as it is
   * likely the SPT switchover has already happened for flows along such RPTs.
   * As for the RPT states it seems that the best thing to do is let them age
   * out gracefully. As long as the FHR and LHR do the right thing RPTs will
   * disappear in time for SSM groups.
   */
  pim_upstream_register_reevaluate ();
  igmp_source_forward_reevaluate_all ();
}

void
pim_ssm_prefix_list_update (struct prefix_list *plist)
{
  struct pim_ssm *ssm = pimg->ssm_info;

  if (!ssm->plist_name || strcmp (ssm->plist_name, prefix_list_name (plist)))
    {
      /* not ours */
      return;
    }

  pim_ssm_range_reevaluate ();
}

static int
pim_is_grp_standard_ssm (struct prefix *group)
{
  static int first = 1;
  static struct prefix group_ssm;

  if (first)
    {
      str2prefix (PIM_SSM_STANDARD_RANGE, &group_ssm);
      first = 0;
    }

  return prefix_match (&group_ssm, group);
}

int
pim_is_grp_ssm (struct in_addr group_addr)
{
  struct pim_ssm *ssm;
  struct prefix group;
  struct prefix_list *plist;

  memset (&group, 0, sizeof (group));
  group.family = AF_INET;
  group.u.prefix4 = group_addr;
  group.prefixlen = 32;

  ssm = pimg->ssm_info;
  if (!ssm->plist_name)
    {
      return pim_is_grp_standard_ssm (&group);
    }

  plist = prefix_list_lookup (AFI_IP, ssm->plist_name);
  if (!plist)
    return 0;

  return (prefix_list_apply (plist, &group) == PREFIX_PERMIT);
}

int
pim_ssm_range_set (vrf_id_t vrf_id, const char *plist_name)
{
  struct pim_ssm *ssm;
  int change = 0;

  if (vrf_id != VRF_DEFAULT)
    return PIM_SSM_ERR_NO_VRF;

  ssm = pimg->ssm_info;
  if (plist_name)
    {
      if (ssm->plist_name)
        {
          if (!strcmp (ssm->plist_name, plist_name))
            return PIM_SSM_ERR_DUP;
          XFREE (MTYPE_PIM_FILTER_NAME, ssm->plist_name);
        }
      ssm->plist_name = XSTRDUP (MTYPE_PIM_FILTER_NAME, plist_name);
      change = 1;
    }
  else
    {
      if (ssm->plist_name)
        {
          change = 1;
          XFREE (MTYPE_PIM_FILTER_NAME, ssm->plist_name);
        }
    }

  if (change)
    pim_ssm_range_reevaluate ();

  return PIM_SSM_ERR_NONE;
}

void *
pim_ssm_init (vrf_id_t vrf_id)
{
  struct pim_ssm *ssm;

  ssm = XCALLOC (MTYPE_PIM_SSM_INFO, sizeof (*ssm));
  ssm->vrf_id = vrf_id;

  return ssm;
}

void
pim_ssm_terminate (struct pim_ssm *ssm)
{
  if (ssm && ssm->plist_name)
    XFREE (MTYPE_PIM_FILTER_NAME, ssm->plist_name);
}