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/*
*
* Connection Manager
*
* Copyright (C) 2007-2012 Intel Corporation. All rights reserved.
* Copyright (C) 2012-2014 BMW Car IT GmbH.
*
* 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 <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include "connman.h"
static char *default_interface;
static GHashTable *nat_hash;
struct connman_nat {
char *address;
unsigned char prefixlen;
struct firewall_context *fw;
char *interface;
};
static int enable_ip_forward(bool enable)
{
static char value = 0;
int f, err = 0;
if ((f = open("/proc/sys/net/ipv4/ip_forward", O_CLOEXEC | O_RDWR)) < 0)
return -errno;
if (!value) {
if (read(f, &value, sizeof(value)) < 0)
value = 0;
if (lseek(f, 0, SEEK_SET) < 0) {
close(f);
return -errno;
}
}
if (enable) {
char allow = '1';
if (write (f, &allow, sizeof(allow)) < 0)
err = -errno;
} else {
char deny = '0';
if (value)
deny = value;
if (write(f, &deny, sizeof(deny)) < 0)
err = -errno;
value = 0;
}
close(f);
return err;
}
static int enable_nat(struct connman_nat *nat)
{
g_free(nat->interface);
nat->interface = g_strdup(default_interface);
if (!nat->interface)
return 0;
return __connman_firewall_enable_nat(nat->fw, nat->address,
nat->prefixlen, nat->interface);
}
static void disable_nat(struct connman_nat *nat)
{
if (!nat->interface)
return;
__connman_firewall_disable_nat(nat->fw);
}
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)
goto err;
nat->fw = __connman_firewall_create();
if (!nat->fw)
goto err;
nat->address = g_strdup(address);
nat->prefixlen = prefixlen;
g_hash_table_replace(nat_hash, g_strdup(name), nat);
return enable_nat(nat);
err:
if (nat) {
if (nat->fw)
__connman_firewall_destroy(nat->fw);
g_free(nat);
}
if (g_hash_table_size(nat_hash) == 0)
enable_ip_forward(false);
return -ENOMEM;
}
void __connman_nat_disable(const char *name)
{
struct connman_nat *nat;
nat = g_hash_table_lookup(nat_hash, name);
if (!nat)
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)) {
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;
__connman_firewall_destroy(nat->fw);
g_free(nat->address);
g_free(nat->interface);
g_free(nat);
}
static const 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);
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;
connman_notifier_unregister(&nat_notifier);
}
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