Add comment questioning part of previous change (Denis?).

[mirror_frr.git] / zebra / if_sysctl.c

/*
 * Get interface's address and mask information by sysctl() function.
 * Copyright (C) 1997, 98 Kunihiro Ishiguro
 *
 * 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 "sockunion.h"
#include "prefix.h"
#include "connected.h"
#include "memory.h"
#include "ioctl.h"
#include "log.h"

#include "zebra/rt.h"
#include "zebra/kernel_socket.h"

void
ifstat_update_sysctl (void)
{
  caddr_t ref, buf, end;
  size_t bufsiz;
  struct if_msghdr *ifm;
  struct interface *ifp;

#define MIBSIZ 6
  int mib[MIBSIZ] =
  { 
    CTL_NET,
    PF_ROUTE,
    0,
    0, /*  AF_INET & AF_INET6 */
    NET_RT_IFLIST,
    0 
  };

  /* Query buffer size. */
  if (sysctl (mib, MIBSIZ, NULL, &bufsiz, NULL, 0) < 0) 
    {
      zlog_warn ("sysctl() error by %s", safe_strerror (errno));
      return;
    }

  /* We free this memory at the end of this function. */
  ref = buf = XMALLOC (MTYPE_TMP, bufsiz);

  /* Fetch interface informations into allocated buffer. */
  if (sysctl (mib, MIBSIZ, buf, &bufsiz, NULL, 0) < 0) 
    {
      zlog (NULL, LOG_WARNING, "sysctl error by %s", safe_strerror (errno));
      return;
    }

  /* Parse both interfaces and addresses. */
  for (end = buf + bufsiz; buf < end; buf += ifm->ifm_msglen) 
    {
      ifm = (struct if_msghdr *) buf;
      if (ifm->ifm_type == RTM_IFINFO)
	{
	  ifp = if_lookup_by_index (ifm->ifm_index);
	  if (ifp)
	    ifp->stats = ifm->ifm_data;
	}
    }

  /* Free sysctl buffer. */
  XFREE (MTYPE_TMP, ref);

  return;
}

/* Interface listing up function using sysctl(). */
void
interface_list ()
{
  caddr_t ref, buf, end;
  size_t bufsiz;
  struct if_msghdr *ifm;

#define MIBSIZ 6
  int mib[MIBSIZ] =
  { 
    CTL_NET,
    PF_ROUTE,
    0,
    0, /*  AF_INET & AF_INET6 */
    NET_RT_IFLIST,
    0 
  };

  /* Query buffer size. */
  if (sysctl (mib, MIBSIZ, NULL, &bufsiz, NULL, 0) < 0) 
    {
      zlog (NULL, LOG_WARNING, "sysctl() error by %s", safe_strerror (errno));
      return;
    }

  /* We free this memory at the end of this function. */
  ref = buf = XMALLOC (MTYPE_TMP, bufsiz);

  /* Fetch interface informations into allocated buffer. */
  if (sysctl (mib, MIBSIZ, buf, &bufsiz, NULL, 0) < 0) 
    {
      zlog (NULL, LOG_WARNING, "sysctl error by %s", safe_strerror (errno));
      return;
    }

  /* Parse both interfaces and addresses. */
  for (end = buf + bufsiz; buf < end; buf += ifm->ifm_msglen) 
    {
      ifm = (struct if_msghdr *) buf;

      switch (ifm->ifm_type) 
	{
	case RTM_IFINFO:
	  ifm_read (ifm);
	  break;
	case RTM_NEWADDR:
	  ifam_read ((struct ifa_msghdr *) ifm);
	  break;
	default:
	  zlog_info ("interfaces_list(): unexpected message type");
	  XFREE (MTYPE_TMP, ref);
	  return;
	  break;
	}
    }

  /* Free sysctl buffer. */
  XFREE (MTYPE_TMP, ref);
}