inet/check_pf.c

   1 /* Determine protocol families for which interfaces exist.  Generic version.
   2    Copyright (C) 2003, 2006 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             struct in6addrinfo **in6ai, size_t *in6ailen)
  28 {
  29   /* By default we have no way to determine information about
  30      deprecated and temporary addresses.  */
  31   *in6ai = NULL;
  32   *in6ailen = 0;
  33
  34   /* Get the interface list via getifaddrs.  */
  35   struct ifaddrs *ifa = NULL;
  36   if (getifaddrs (&ifa) != 0)
  37     {
  38       /* We cannot determine what interfaces are available.  Be
  39          pessimistic.  */
  40       *seen_ipv4 = true;
  41       *seen_ipv6 = true;
  42       return;
  43     }
  44
  45   *seen_ipv4 = false;
  46   *seen_ipv6 = false;
  47
  48   struct ifaddrs *runp;
  49   for (runp = ifa; runp != NULL; runp = runp->ifa_next)
  50     if (runp->ifa_addr->sa_family == PF_INET)
  51       *seen_ipv4 = true;
  52     else if (runp->ifa_addr->sa_family == PF_INET6)
  53       *seen_ipv6 = true;
  54
  55   (void) freeifaddrs (ifa);
  56 }