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/*
* Fetch ipforward value by reading /proc filesystem.
* Copyright (C) 1997 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 "log.h"
#include "privs.h"
#include "zebra/ipforward.h"
extern struct zebra_privs_t zserv_privs;
char proc_net_snmp[] = "/proc/net/snmp";
static void
dropline (FILE *fp)
{
int c;
while ((c = getc (fp)) != '\n')
;
}
int
ipforward (void)
{
FILE *fp;
int ipforwarding = 0;
char *pnt;
char buf[10];
fp = fopen (proc_net_snmp, "r");
if (fp == NULL)
return -1;
/* We don't care about the first line. */
dropline (fp);
/* Get ip_statistics.IpForwarding :
1 => ip forwarding enabled
2 => ip forwarding off. */
pnt = fgets (buf, 6, fp);
sscanf (buf, "Ip: %d", &ipforwarding);
fclose(fp);
if (ipforwarding == 1)
return 1;
return 0;
}
/* char proc_ipv4_forwarding[] = "/proc/sys/net/ipv4/conf/all/forwarding"; */
char proc_ipv4_forwarding[] = "/proc/sys/net/ipv4/ip_forward";
int
ipforward_on (void)
{
FILE *fp;
if ( zserv_privs.change(ZPRIVS_RAISE) )
zlog_err ("Can't raise privileges, %s", safe_strerror (errno) );
fp = fopen (proc_ipv4_forwarding, "w");
if (fp == NULL) {
if ( zserv_privs.change(ZPRIVS_LOWER) )
zlog_err ("Can't lower privileges, %s", safe_strerror (errno));
return -1;
}
fprintf (fp, "1\n");
fclose (fp);
if ( zserv_privs.change(ZPRIVS_LOWER) )
zlog_err ("Can't lower privileges, %s", safe_strerror (errno));
return ipforward ();
}
int
ipforward_off (void)
{
FILE *fp;
if ( zserv_privs.change(ZPRIVS_RAISE) )
zlog_err ("Can't raise privileges, %s", safe_strerror (errno));
fp = fopen (proc_ipv4_forwarding, "w");
if (fp == NULL) {
if ( zserv_privs.change(ZPRIVS_LOWER) )
zlog_err ("Can't lower privileges, %s", safe_strerror (errno));
return -1;
}
fprintf (fp, "0\n");
fclose (fp);
if ( zserv_privs.change(ZPRIVS_LOWER) )
zlog_err ("Can't lower privileges, %s", safe_strerror (errno));
return ipforward ();
}
#ifdef HAVE_IPV6
char proc_ipv6_forwarding[] = "/proc/sys/net/ipv6/conf/all/forwarding";
int
ipforward_ipv6 (void)
{
FILE *fp;
char buf[5];
int ipforwarding = 0;
fp = fopen (proc_ipv6_forwarding, "r");
if (fp == NULL)
return -1;
fgets (buf, 2, fp);
sscanf (buf, "%d", &ipforwarding);
fclose (fp);
return ipforwarding;
}
int
ipforward_ipv6_on (void)
{
FILE *fp;
if ( zserv_privs.change(ZPRIVS_RAISE) )
zlog_err ("Can't raise privileges, %s", safe_strerror (errno));
fp = fopen (proc_ipv6_forwarding, "w");
if (fp == NULL) {
if ( zserv_privs.change(ZPRIVS_LOWER) )
zlog_err ("Can't lower privileges, %s", safe_strerror (errno));
return -1;
}
fprintf (fp, "1\n");
fclose (fp);
if ( zserv_privs.change(ZPRIVS_LOWER) )
zlog_err ("Can't lower privileges, %s", safe_strerror (errno));
return ipforward_ipv6 ();
}
int
ipforward_ipv6_off (void)
{
FILE *fp;
if ( zserv_privs.change(ZPRIVS_RAISE) )
zlog_err ("Can't raise privileges, %s", safe_strerror (errno));
fp = fopen (proc_ipv6_forwarding, "w");
if (fp == NULL) {
if ( zserv_privs.change(ZPRIVS_LOWER) )
zlog_err ("Can't lower privileges, %s", safe_strerror (errno));
return -1;
}
fprintf (fp, "0\n");
fclose (fp);
if ( zserv_privs.change(ZPRIVS_LOWER) )
zlog_err ("Can't lower privileges, %s", safe_strerror (errno));
return ipforward_ipv6 ();
}
#endif /* HAVE_IPV6 */
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