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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Fetch ipforward value by reading /proc filesystem.
* Copyright (C) 1997 Kunihiro Ishiguro
*/
#include <zebra.h>
#ifdef GNU_LINUX
#include "log.h"
#include "privs.h"
#include "zebra/ipforward.h"
extern struct zebra_privs_t zserv_privs;
static const char proc_net_snmp[] = "/proc/net/snmp";
static void dropline(FILE *fp)
{
while (getc(fp) != '\n')
;
}
int ipforward(void)
{
int ret = 0;
FILE *fp;
int ipforwarding = 0;
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. */
if (fgets(buf, 6, fp))
ret = sscanf(buf, "Ip: %d", &ipforwarding);
fclose(fp);
if (ret == 1 && ipforwarding == 1)
return 1;
return 0;
}
/* char proc_ipv4_forwarding[] = "/proc/sys/net/ipv4/conf/all/forwarding"; */
static const char proc_ipv4_forwarding[] = "/proc/sys/net/ipv4/ip_forward";
int ipforward_on(void)
{
FILE *fp;
frr_with_privs(&zserv_privs) {
fp = fopen(proc_ipv4_forwarding, "w");
if (fp == NULL) {
return -1;
}
fprintf(fp, "1\n");
fclose(fp);
}
return ipforward();
}
int ipforward_off(void)
{
FILE *fp;
frr_with_privs(&zserv_privs) {
fp = fopen(proc_ipv4_forwarding, "w");
if (fp == NULL) {
return -1;
}
fprintf(fp, "0\n");
fclose(fp);
}
return ipforward();
}
static const char proc_ipv6_forwarding[] =
"/proc/sys/net/ipv6/conf/all/forwarding";
int ipforward_ipv6(void)
{
int ret = 0;
FILE *fp;
char buf[5];
int ipforwarding = 0;
fp = fopen(proc_ipv6_forwarding, "r");
if (fp == NULL)
return -1;
if (fgets(buf, 2, fp))
ret = sscanf(buf, "%d", &ipforwarding);
fclose(fp);
if (ret != 1)
return 0;
return ipforwarding;
}
int ipforward_ipv6_on(void)
{
FILE *fp;
frr_with_privs(&zserv_privs) {
fp = fopen(proc_ipv6_forwarding, "w");
if (fp == NULL) {
return -1;
}
fprintf(fp, "1\n");
fclose(fp);
}
return ipforward_ipv6();
}
int ipforward_ipv6_off(void)
{
FILE *fp;
frr_with_privs(&zserv_privs) {
fp = fopen(proc_ipv6_forwarding, "w");
if (fp == NULL) {
return -1;
}
fprintf(fp, "0\n");
fclose(fp);
}
return ipforward_ipv6();
}
#endif /* GNU_LINUX */
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