inet/check_pf.c

   1 /* Determine protocol families for which interfaces exist.  Generic version.
   2    Copyright (C) 2003 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <ifaddrs.h>
  21 #include <netdb.h>
  22
  23
  24 void
  25 attribute_hidden
  26 __check_pf (bool *seen_ipv4, bool *seen_ipv6)
  27 {
  28   /* Get the interface list via getifaddrs.  */
  29   struct ifaddrs *ifa = NULL;
  30   if (getifaddrs (&ifa) != 0)
  31     {
  32       /* We cannot determine what interfaces are available.  Be
  33          pessimistic.  */
  34       *seen_ipv4 = true;
  35       *seen_ipv6 = true;
  36       return;
  37     }
  38
  39   *seen_ipv4 = false;
  40   *seen_ipv6 = false;
  41
  42   struct ifaddrs *runp;
  43   for (runp = ifa; runp != NULL; runp = runp->ifa_next)
  44     if (runp->ifa_addr->sa_family == PF_INET)
  45       *seen_ipv4 = true;
  46     else if (runp->ifa_addr->sa_family == PF_INET6)
  47       *seen_ipv6 = true;
  48
  49   (void) freeifaddrs (ifa);
  50 }