src/tethering.c

   1 /*
   2  *
   3  *  Connection Manager
   4  *
   5  *  Copyright (C) 2007-2012  Intel Corporation. All rights reserved.
   6  *  Copyright (C) 2011  ProFUSION embedded systems
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License version 2 as
  10  *  published by the Free Software Foundation.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  20  *
  21  */
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26
  27 #include <errno.h>
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30 #include <unistd.h>
  31 #include <stdio.h>
  32 #include <sys/ioctl.h>
  33 #include <net/if.h>
  34 #include <linux/sockios.h>
  35 #include <string.h>
  36 #include <fcntl.h>
  37 #include <linux/if_tun.h>
  38 #include <linux/if_bridge.h>
  39
  40 #include "connman.h"
  41
  42 #include <gdhcp/gdhcp.h>
  43
  44 #include <gdbus.h>
  45
  46 #ifndef DBUS_TYPE_UNIX_FD
  47 #define DBUS_TYPE_UNIX_FD -1
  48 #endif
  49
  50 #define BRIDGE_NAME "tether"
  51 #define BRIDGE_DNS "8.8.8.8"
  52
  53 #define DEFAULT_MTU     1500
  54
  55 #define PRIVATE_NETWORK_PRIMARY_DNS BRIDGE_DNS
  56 #define PRIVATE_NETWORK_SECONDARY_DNS "8.8.4.4"
  57
  58 static volatile int tethering_enabled;
  59 static GDHCPServer *tethering_dhcp_server = NULL;
  60 static struct connman_ippool *dhcp_ippool = NULL;
  61 static DBusConnection *connection;
  62 static GHashTable *pn_hash;
  63
  64 struct connman_private_network {
  65         char *owner;
  66         char *path;
  67         guint watch;
  68         DBusMessage *msg;
  69         DBusMessage *reply;
  70         int fd;
  71         char *interface;
  72         int index;
  73         guint iface_watch;
  74         struct connman_ippool *pool;
  75         const char *primary_dns;
  76         const char *secondary_dns;
  77 };
  78
  79 const char *__connman_tethering_get_bridge(void)
  80 {
  81         int sk, err;
  82         unsigned long args[3];
  83
  84         sk = socket(AF_INET, SOCK_STREAM, 0);
  85         if (sk < 0)
  86                 return NULL;
  87
  88         args[0] = BRCTL_GET_VERSION;
  89         args[1] = args[2] = 0;
  90         err = ioctl(sk, SIOCGIFBR, &args);
  91         close(sk);
  92         if (err == -1)
  93                 return NULL;
  94
  95         return BRIDGE_NAME;
  96 }
  97
  98 static void dhcp_server_debug(const char *str, void *data)
  99 {
 100         connman_info("%s: %s\n", (const char *) data, str);
 101 }
 102
 103 static void dhcp_server_error(GDHCPServerError error)
 104 {
 105         switch (error) {
 106         case G_DHCP_SERVER_ERROR_NONE:
 107                 connman_error("OK");
 108                 break;
 109         case G_DHCP_SERVER_ERROR_INTERFACE_UNAVAILABLE:
 110                 connman_error("Interface unavailable");
 111                 break;
 112         case G_DHCP_SERVER_ERROR_INTERFACE_IN_USE:
 113                 connman_error("Interface in use");
 114                 break;
 115         case G_DHCP_SERVER_ERROR_INTERFACE_DOWN:
 116                 connman_error("Interface down");
 117                 break;
 118         case G_DHCP_SERVER_ERROR_NOMEM:
 119                 connman_error("No memory");
 120                 break;
 121         case G_DHCP_SERVER_ERROR_INVALID_INDEX:
 122                 connman_error("Invalid index");
 123                 break;
 124         case G_DHCP_SERVER_ERROR_INVALID_OPTION:
 125                 connman_error("Invalid option");
 126                 break;
 127         case G_DHCP_SERVER_ERROR_IP_ADDRESS_INVALID:
 128                 connman_error("Invalid address");
 129                 break;
 130         }
 131 }
 132
 133 static GDHCPServer *dhcp_server_start(const char *bridge,
 134                                 const char *router, const char* subnet,
 135                                 const char *start_ip, const char *end_ip,
 136                                 unsigned int lease_time, const char *dns)
 137 {
 138         GDHCPServerError error;
 139         GDHCPServer *dhcp_server;
 140         int index;
 141
 142         DBG("");
 143
 144         index = connman_inet_ifindex(bridge);
 145         if (index < 0)
 146                 return NULL;
 147
 148         dhcp_server = g_dhcp_server_new(G_DHCP_IPV4, index, &error);
 149         if (dhcp_server == NULL) {
 150                 dhcp_server_error(error);
 151                 return NULL;
 152         }
 153
 154         g_dhcp_server_set_debug(dhcp_server, dhcp_server_debug, "DHCP server");
 155
 156         g_dhcp_server_set_lease_time(dhcp_server, lease_time);
 157         g_dhcp_server_set_option(dhcp_server, G_DHCP_SUBNET, subnet);
 158         g_dhcp_server_set_option(dhcp_server, G_DHCP_ROUTER, router);
 159         g_dhcp_server_set_option(dhcp_server, G_DHCP_DNS_SERVER, dns);
 160         g_dhcp_server_set_ip_range(dhcp_server, start_ip, end_ip);
 161
 162         g_dhcp_server_start(dhcp_server);
 163
 164         return dhcp_server;
 165 }
 166
 167 static void dhcp_server_stop(GDHCPServer *server)
 168 {
 169         if (server == NULL)
 170                 return;
 171
 172         g_dhcp_server_unref(server);
 173 }
 174
 175 static void tethering_restart(struct connman_ippool *pool, void *user_data)
 176 {
 177         __connman_tethering_set_disabled();
 178         __connman_tethering_set_enabled();
 179 }
 180
 181 void __connman_tethering_set_enabled(void)
 182 {
 183         int index;
 184         int err;
 185         const char *gateway;
 186         const char *broadcast;
 187         const char *subnet_mask;
 188         const char *start_ip;
 189         const char *end_ip;
 190         const char *dns;
 191         unsigned char prefixlen;
 192
 193         DBG("enabled %d", tethering_enabled + 1);
 194
 195         if (__sync_fetch_and_add(&tethering_enabled, 1) != 0)
 196                 return;
 197
 198         err = __connman_bridge_create(BRIDGE_NAME);
 199         if (err < 0)
 200                 return;
 201
 202         index = connman_inet_ifindex(BRIDGE_NAME);
 203         dhcp_ippool = __connman_ippool_create(index, 2, 252,
 204                                                 tethering_restart, NULL);
 205         if (dhcp_ippool == NULL) {
 206                 connman_error("Fail to create IP pool");
 207                 return;
 208         }
 209
 210         gateway = __connman_ippool_get_gateway(dhcp_ippool);
 211         broadcast = __connman_ippool_get_broadcast(dhcp_ippool);
 212         subnet_mask = __connman_ippool_get_subnet_mask(dhcp_ippool);
 213         start_ip = __connman_ippool_get_start_ip(dhcp_ippool);
 214         end_ip = __connman_ippool_get_end_ip(dhcp_ippool);
 215
 216         err = __connman_bridge_enable(BRIDGE_NAME, gateway, broadcast);
 217         if (err < 0 && err != -EALREADY) {
 218                 __connman_bridge_remove(BRIDGE_NAME);
 219                 return;
 220         }
 221
 222         dns = gateway;
 223         if (__connman_dnsproxy_add_listener(BRIDGE_NAME) < 0) {
 224                 connman_error("Can't add listener %s to DNS proxy",
 225                                                                 BRIDGE_NAME);
 226                 dns = BRIDGE_DNS;
 227         }
 228
 229         tethering_dhcp_server = dhcp_server_start(BRIDGE_NAME,
 230                                                 gateway, subnet_mask,
 231                                                 start_ip, end_ip,
 232                                                 24 * 3600, dns);
 233         if (tethering_dhcp_server == NULL) {
 234                 __connman_bridge_disable(BRIDGE_NAME);
 235                 __connman_bridge_remove(BRIDGE_NAME);
 236                 return;
 237         }
 238
 239         prefixlen =
 240                 __connman_ipconfig_netmask_prefix_len(subnet_mask);
 241         __connman_nat_enable(BRIDGE_NAME, start_ip, prefixlen);
 242
 243         DBG("tethering started");
 244 }
 245
 246 void __connman_tethering_set_disabled(void)
 247 {
 248         DBG("enabled %d", tethering_enabled - 1);
 249
 250         __connman_dnsproxy_remove_listener(BRIDGE_NAME);
 251
 252         if (__sync_fetch_and_sub(&tethering_enabled, 1) != 1)
 253                 return;
 254
 255         __connman_nat_disable(BRIDGE_NAME);
 256
 257         dhcp_server_stop(tethering_dhcp_server);
 258
 259         tethering_dhcp_server = NULL;
 260
 261         __connman_bridge_disable(BRIDGE_NAME);
 262
 263         __connman_ippool_unref(dhcp_ippool);
 264
 265         __connman_bridge_remove(BRIDGE_NAME);
 266
 267         DBG("tethering stopped");
 268 }
 269
 270 static void setup_tun_interface(unsigned int flags, unsigned change,
 271                 void *data)
 272 {
 273         struct connman_private_network *pn = data;
 274         unsigned char prefixlen;
 275         DBusMessageIter array, dict;
 276         const char *server_ip;
 277         const char *peer_ip;
 278         const char *subnet_mask;
 279         int err;
 280
 281         DBG("index %d flags %d change %d", pn->index,  flags, change);
 282
 283         if (flags & IFF_UP)
 284                 return;
 285
 286         subnet_mask = __connman_ippool_get_subnet_mask(pn->pool);
 287         server_ip = __connman_ippool_get_start_ip(pn->pool);
 288         peer_ip = __connman_ippool_get_end_ip(pn->pool);
 289         prefixlen =
 290                 __connman_ipconfig_netmask_prefix_len(subnet_mask);
 291
 292         if ((__connman_inet_modify_address(RTM_NEWADDR,
 293                                 NLM_F_REPLACE | NLM_F_ACK, pn->index, AF_INET,
 294                                 server_ip, peer_ip, prefixlen, NULL)) < 0) {
 295                 DBG("address setting failed");
 296                 return;
 297         }
 298
 299         connman_inet_ifup(pn->index);
 300
 301         err = __connman_nat_enable(BRIDGE_NAME, server_ip, prefixlen);
 302         if (err < 0) {
 303                 connman_error("failed to enable NAT");
 304                 goto error;
 305         }
 306
 307         dbus_message_iter_init_append(pn->reply, &array);
 308
 309         dbus_message_iter_append_basic(&array, DBUS_TYPE_OBJECT_PATH,
 310                                                 &pn->path);
 311
 312         connman_dbus_dict_open(&array, &dict);
 313
 314         connman_dbus_dict_append_basic(&dict, "ServerIPv4",
 315                                         DBUS_TYPE_STRING, &server_ip);
 316         connman_dbus_dict_append_basic(&dict, "PeerIPv4",
 317                                         DBUS_TYPE_STRING, &peer_ip);
 318         connman_dbus_dict_append_basic(&dict, "PrimaryDNS",
 319                                         DBUS_TYPE_STRING, &pn->primary_dns);
 320         connman_dbus_dict_append_basic(&dict, "SecondaryDNS",
 321                                         DBUS_TYPE_STRING, &pn->secondary_dns);
 322
 323         connman_dbus_dict_close(&array, &dict);
 324
 325         dbus_message_iter_append_basic(&array, DBUS_TYPE_UNIX_FD, &pn->fd);
 326
 327         g_dbus_send_message(connection, pn->reply);
 328
 329         return;
 330
 331 error:
 332         pn->reply = __connman_error_failed(pn->msg, -err);
 333         g_dbus_send_message(connection, pn->reply);
 334
 335         g_hash_table_remove(pn_hash, pn->path);
 336 }
 337
 338 static void remove_private_network(gpointer user_data)
 339 {
 340         struct connman_private_network *pn = user_data;
 341
 342         __connman_nat_disable(BRIDGE_NAME);
 343         connman_rtnl_remove_watch(pn->iface_watch);
 344         __connman_ippool_unref(pn->pool);
 345
 346         if (pn->watch > 0) {
 347                 g_dbus_remove_watch(connection, pn->watch);
 348                 pn->watch = 0;
 349         }
 350
 351         close(pn->fd);
 352
 353         g_free(pn->interface);
 354         g_free(pn->owner);
 355         g_free(pn->path);
 356         g_free(pn);
 357 }
 358
 359 static void owner_disconnect(DBusConnection *conn, void *user_data)
 360 {
 361         struct connman_private_network *pn = user_data;
 362
 363         DBG("%s died", pn->owner);
 364
 365         pn->watch = 0;
 366
 367         g_hash_table_remove(pn_hash, pn->path);
 368 }
 369
 370 static void ippool_disconnect(struct connman_ippool *pool, void *user_data)
 371 {
 372         struct connman_private_network *pn = user_data;
 373
 374         DBG("block used externally");
 375
 376         g_hash_table_remove(pn_hash, pn->path);
 377 }
 378
 379 int __connman_private_network_request(DBusMessage *msg, const char *owner)
 380 {
 381         struct connman_private_network *pn;
 382         char *iface = NULL;
 383         char *path = NULL;
 384         int index, fd, err;
 385
 386         if (DBUS_TYPE_UNIX_FD < 0)
 387                 return -EINVAL;
 388
 389         fd = connman_inet_create_tunnel(&iface);
 390         if (fd < 0)
 391                 return fd;
 392
 393         path = g_strdup_printf("/tethering/%s", iface);
 394
 395         pn = g_hash_table_lookup(pn_hash, path);
 396         if (pn) {
 397                 g_free(path);
 398                 g_free(iface);
 399                 close(fd);
 400                 return -EEXIST;
 401         }
 402
 403         index = connman_inet_ifindex(iface);
 404         if (index < 0) {
 405                 err = -ENODEV;
 406                 goto error;
 407         }
 408         DBG("interface %s", iface);
 409
 410         err = connman_inet_set_mtu(index, DEFAULT_MTU);
 411
 412         pn = g_try_new0(struct connman_private_network, 1);
 413         if (pn == NULL) {
 414                 err = -ENOMEM;
 415                 goto error;
 416         }
 417
 418         pn->owner = g_strdup(owner);
 419         pn->path = path;
 420         pn->watch = g_dbus_add_disconnect_watch(connection, pn->owner,
 421                                         owner_disconnect, pn, NULL);
 422         pn->msg = msg;
 423         pn->reply = dbus_message_new_method_return(pn->msg);
 424         if (pn->reply == NULL)
 425                 goto error;
 426
 427         pn->fd = fd;
 428         pn->interface = iface;
 429         pn->index = index;
 430         pn->pool = __connman_ippool_create(pn->index, 1, 1, ippool_disconnect, pn);
 431         if (pn->pool == NULL) {
 432                 errno = -ENOMEM;
 433                 goto error;
 434         }
 435
 436         pn->primary_dns = PRIVATE_NETWORK_PRIMARY_DNS;
 437         pn->secondary_dns = PRIVATE_NETWORK_SECONDARY_DNS;
 438
 439         pn->iface_watch = connman_rtnl_add_newlink_watch(index,
 440                                                 setup_tun_interface, pn);
 441
 442         g_hash_table_insert(pn_hash, pn->path, pn);
 443
 444         return 0;
 445
 446 error:
 447         close(fd);
 448         g_free(iface);
 449         g_free(path);
 450         g_free(pn);
 451         return err;
 452 }
 453
 454 int __connman_private_network_release(const char *path)
 455 {
 456         struct connman_private_network *pn;
 457
 458         pn = g_hash_table_lookup(pn_hash, path);
 459         if (pn == NULL)
 460                 return -EACCES;
 461
 462         g_hash_table_remove(pn_hash, path);
 463         return 0;
 464 }
 465
 466 int __connman_tethering_init(void)
 467 {
 468         DBG("");
 469
 470         tethering_enabled = 0;
 471
 472         connection = connman_dbus_get_connection();
 473         if (connection == NULL)
 474                 return -EFAULT;
 475
 476         pn_hash = g_hash_table_new_full(g_str_hash, g_str_equal,
 477                                                 NULL, remove_private_network);
 478
 479         return 0;
 480 }
 481
 482 void __connman_tethering_cleanup(void)
 483 {
 484         DBG("");
 485
 486         __sync_synchronize();
 487         if (tethering_enabled == 0) {
 488                 if (tethering_dhcp_server)
 489                         dhcp_server_stop(tethering_dhcp_server);
 490                 __connman_bridge_disable(BRIDGE_NAME);
 491                 __connman_bridge_remove(BRIDGE_NAME);
 492                 __connman_nat_disable(BRIDGE_NAME);
 493         }
 494
 495         if (connection == NULL)
 496                 return;
 497
 498         g_hash_table_destroy(pn_hash);
 499         dbus_connection_unref(connection);
 500 }