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/*
*
* Connection Manager
*
* Copyright (C) 2007-2012 Intel Corporation. All rights reserved.
* Copyright (C) 2012 BMW Car IT GmbH. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <errno.h>
#include <stdio.h>
#include "connman.h"
static char *default_interface;
static GHashTable *nat_hash;
struct connman_nat {
char *address;
unsigned char prefixlen;
char *interface;
};
static int enable_ip_forward(connman_bool_t enable)
{
FILE *f;
f = fopen("/proc/sys/net/ipv4/ip_forward", "r+");
if (f == NULL)
return -errno;
if (enable == TRUE)
fprintf(f, "1");
else
fprintf(f, "0");
fclose(f);
return 0;
}
static void flush_nat(void)
{
int err;
err = __connman_iptables_command("-t nat -F POSTROUTING");
if (err < 0) {
DBG("Flushing the nat table failed");
return;
}
__connman_iptables_commit("nat");
}
static int enable_nat(struct connman_nat *nat)
{
int err;
g_free(nat->interface);
nat->interface = g_strdup(default_interface);
if (nat->interface == NULL)
return 0;
/* Enable masquerading */
err = __connman_iptables_command("-t nat -A POSTROUTING "
"-s %s/%d -o %s -j MASQUERADE",
nat->address,
nat->prefixlen,
nat->interface);
if (err < 0)
return err;
return __connman_iptables_commit("nat");
}
static void disable_nat(struct connman_nat *nat)
{
int err;
if (nat->interface == NULL)
return;
/* Disable masquerading */
err = __connman_iptables_command("-t nat -D POSTROUTING "
"-s %s/%d -o %s -j MASQUERADE",
nat->address,
nat->prefixlen,
nat->interface);
if (err < 0)
return;
__connman_iptables_commit("nat");
}
int __connman_nat_enable(const char *name, const char *address,
unsigned char prefixlen)
{
struct connman_nat *nat;
int err;
if (g_hash_table_size(nat_hash) == 0) {
err = enable_ip_forward(TRUE);
if (err < 0)
return err;
}
nat = g_try_new0(struct connman_nat, 1);
if (nat == NULL) {
if (g_hash_table_size(nat_hash) == 0)
enable_ip_forward(FALSE);
return -ENOMEM;
}
nat->address = g_strdup(address);
nat->prefixlen = prefixlen;
g_hash_table_replace(nat_hash, g_strdup(name), nat);
return enable_nat(nat);
}
void __connman_nat_disable(const char *name)
{
struct connman_nat *nat;
nat = g_hash_table_lookup(nat_hash, name);
if (nat == NULL)
return;
disable_nat(nat);
g_hash_table_remove(nat_hash, name);
if (g_hash_table_size(nat_hash) == 0)
enable_ip_forward(FALSE);
}
static void update_default_interface(struct connman_service *service)
{
GHashTableIter iter;
gpointer key, value;
char *interface;
int err;
interface = connman_service_get_interface(service);
DBG("interface %s", interface);
g_free(default_interface);
default_interface = interface;
g_hash_table_iter_init(&iter, nat_hash);
while (g_hash_table_iter_next(&iter, &key, &value) == TRUE) {
const char *name = key;
struct connman_nat *nat = value;
disable_nat(nat);
err = enable_nat(nat);
if (err < 0)
DBG("Failed to enable nat for %s", name);
}
}
static void shutdown_nat(gpointer key, gpointer value, gpointer user_data)
{
const char *name = key;
__connman_nat_disable(name);
}
static void cleanup_nat(gpointer data)
{
struct connman_nat *nat = data;
g_free(nat->address);
g_free(nat->interface);
}
static struct connman_notifier nat_notifier = {
.name = "nat",
.default_changed = update_default_interface,
};
int __connman_nat_init(void)
{
int err;
DBG("");
err = connman_notifier_register(&nat_notifier);
if (err < 0)
return err;
nat_hash = g_hash_table_new_full(g_str_hash, g_str_equal,
g_free, cleanup_nat);
flush_nat();
return 0;
}
void __connman_nat_cleanup(void)
{
DBG("");
g_hash_table_foreach(nat_hash, shutdown_nat, NULL);
g_hash_table_destroy(nat_hash);
nat_hash = NULL;
flush_nat();
connman_notifier_unregister(&nat_notifier);
}
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