zebra/ipforward_proc.c

   1 /*
   2  * Fetch ipforward value by reading /proc filesystem.
   3  * Copyright (C) 1997 Kunihiro Ishiguro
   4  *
   5  * This file is part of GNU Zebra.
   6  *
   7  * GNU Zebra is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2, or (at your option) any
  10  * later version.
  11  *
  12  * GNU Zebra is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with GNU Zebra; see the file COPYING.  If not, write to the Free
  19  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  20  * 02111-1307, USA.
  21  */
  22
  23 #include <zebra.h>
  24
  25 char proc_net_snmp[] = "/proc/net/snmp";
  26
  27 static void
  28 dropline (FILE *fp)
  29 {
  30   int c;
  31
  32   while ((c = getc (fp)) != '\n')
  33     ;
  34 }
  35
  36 int
  37 ipforward ()
  38 {
  39   FILE *fp;
  40   int ipforwarding = 0;
  41   char *pnt;
  42   char buf[10];
  43
  44   fp = fopen (proc_net_snmp, "r");
  45
  46   if (fp == NULL)
  47     return -1;
  48
  49   /* We don't care about the first line. */
  50   dropline (fp);
  51
  52   /* Get ip_statistics.IpForwarding :
  53      1 => ip forwarding enabled
  54      2 => ip forwarding off. */
  55   pnt = fgets (buf, 6, fp);
  56   sscanf (buf, "Ip: %d", &ipforwarding);
  57
  58   if (ipforwarding == 1)
  59     return 1;
  60
  61   return 0;
  62 }
  63
  64 /* char proc_ipv4_forwarding[] = "/proc/sys/net/ipv4/conf/all/forwarding"; */
  65 char proc_ipv4_forwarding[] = "/proc/sys/net/ipv4/ip_forward";
  66
  67 int
  68 ipforward_on ()
  69 {
  70   FILE *fp;
  71
  72   fp = fopen (proc_ipv4_forwarding, "w");
  73
  74   if (fp == NULL)
  75     return -1;
  76
  77   fprintf (fp, "1\n");
  78
  79   fclose (fp);
  80
  81   return ipforward ();
  82 }
  83
  84 int
  85 ipforward_off ()
  86 {
  87   FILE *fp;
  88
  89   fp = fopen (proc_ipv4_forwarding, "w");
  90
  91   if (fp == NULL)
  92     return -1;
  93
  94   fprintf (fp, "0\n");
  95
  96   fclose (fp);
  97
  98   return ipforward ();
  99 }
 100 #ifdef HAVE_IPV6
 101
 102 char proc_ipv6_forwarding[] = "/proc/sys/net/ipv6/conf/all/forwarding";
 103
 104 int
 105 ipforward_ipv6 ()
 106 {
 107   FILE *fp;
 108   char buf[5];
 109   int ipforwarding = 0;
 110
 111   fp = fopen (proc_ipv6_forwarding, "r");
 112
 113   if (fp == NULL)
 114     return -1;
 115
 116   fgets (buf, 2, fp);
 117   sscanf (buf, "%d", &ipforwarding);
 118
 119   return ipforwarding;
 120 }
 121
 122 int
 123 ipforward_ipv6_on ()
 124 {
 125   FILE *fp;
 126
 127   fp = fopen (proc_ipv6_forwarding, "w");
 128
 129   if (fp == NULL)
 130     return -1;
 131
 132   fprintf (fp, "1\n");
 133
 134   fclose (fp);
 135
 136   return ipforward_ipv6 ();
 137 }
 138
 139 int
 140 ipforward_ipv6_off ()
 141 {
 142   FILE *fp;
 143
 144   fp = fopen (proc_ipv6_forwarding, "w");
 145
 146   if (fp == NULL)
 147     return -1;
 148
 149   fprintf (fp, "0\n");
 150
 151   fclose (fp);
 152
 153   return ipforward_ipv6 ();
 154 }
 155 #endif /* HAVE_IPV6 */