iw.c

   1 /*
   2  * nl80211 userspace tool
   3  *
   4  * Copyright 2007, 2008 Johannes Berg <johannes@sipsolutions.net>
   5  */
   6
   7 #include <errno.h>
   8 #include <stdio.h>
   9 #include <string.h>
  10 #include <net/if.h>
  11 #include <sys/types.h>
  12 #include <sys/stat.h>
  13 #include <fcntl.h>
  14 #include <unistd.h>
  15
  16 #include <netlink/genl/genl.h>
  17 #include <netlink/genl/family.h>
  18 #include <netlink/genl/ctrl.h>
  19 #include <netlink/msg.h>
  20 #include <netlink/attr.h>
  21
  22 #include "nl80211.h"
  23 #include "iw.h"
  24 #include "version.h"
  25
  26 #ifndef CONFIG_LIBNL20
  27 /* libnl 2.0 compatibility code */
  28
  29 static inline struct nl_handle *nl_socket_alloc(void)
  30 {
  31         return nl_handle_alloc();
  32 }
  33
  34 static inline void nl_socket_free(struct nl_sock *h)
  35 {
  36         nl_handle_destroy(h);
  37 }
  38
  39 static inline int __genl_ctrl_alloc_cache(struct nl_sock *h, struct nl_cache **cache)
  40 {
  41         struct nl_cache *tmp = genl_ctrl_alloc_cache(h);
  42         if (!tmp)
  43                 return -ENOMEM;
  44         *cache = tmp;
  45         return 0;
  46 }
  47 #define genl_ctrl_alloc_cache __genl_ctrl_alloc_cache
  48 #endif /* CONFIG_LIBNL20 */
  49
  50 static int debug = 0;
  51
  52 static int nl80211_init(struct nl80211_state *state)
  53 {
  54         int err;
  55
  56         state->nl_sock = nl_socket_alloc();
  57         if (!state->nl_sock) {
  58                 fprintf(stderr, "Failed to allocate netlink socket.\n");
  59                 return -ENOMEM;
  60         }
  61
  62         if (genl_connect(state->nl_sock)) {
  63                 fprintf(stderr, "Failed to connect to generic netlink.\n");
  64                 err = -ENOLINK;
  65                 goto out_handle_destroy;
  66         }
  67
  68         if (genl_ctrl_alloc_cache(state->nl_sock, &state->nl_cache)) {
  69                 fprintf(stderr, "Failed to allocate generic netlink cache.\n");
  70                 err = -ENOMEM;
  71                 goto out_handle_destroy;
  72         }
  73
  74         state->nl80211 = genl_ctrl_search_by_name(state->nl_cache, "nl80211");
  75         if (!state->nl80211) {
  76                 fprintf(stderr, "nl80211 not found.\n");
  77                 err = -ENOENT;
  78                 goto out_cache_free;
  79         }
  80
  81         return 0;
  82
  83  out_cache_free:
  84         nl_cache_free(state->nl_cache);
  85  out_handle_destroy:
  86         nl_socket_free(state->nl_sock);
  87         return err;
  88 }
  89
  90 static void nl80211_cleanup(struct nl80211_state *state)
  91 {
  92         genl_family_put(state->nl80211);
  93         nl_cache_free(state->nl_cache);
  94         nl_socket_free(state->nl_sock);
  95 }
  96
  97 __COMMAND(NULL, NULL, NULL, 0, 0, 0, CIB_NONE, NULL);
  98 __COMMAND(NULL, NULL, NULL, 1, 0, 0, CIB_NONE, NULL);
  99
 100 static int cmd_size;
 101
 102 static void usage(const char *argv0)
 103 {
 104         struct cmd *cmd;
 105
 106         fprintf(stderr, "Usage:\t%s [options] command\n", argv0);
 107         fprintf(stderr, "Options:\n");
 108         fprintf(stderr, "\t--debug\t\tenable netlink debugging\n");
 109         fprintf(stderr, "\t--version\tshow version\n");
 110         fprintf(stderr, "Commands:\n");
 111         fprintf(stderr, "\thelp\n");
 112         fprintf(stderr, "\tevent\n");
 113         for (cmd = &__start___cmd; cmd < &__stop___cmd;
 114              cmd = (struct cmd *)((char *)cmd + cmd_size)) {
 115                 if (!cmd->handler || cmd->hidden)
 116                         continue;
 117                 switch (cmd->idby) {
 118                 case CIB_NONE:
 119                         fprintf(stderr, "\t");
 120                         break;
 121                 case CIB_PHY:
 122                         fprintf(stderr, "\tphy <phyname> ");
 123                         break;
 124                 case CIB_NETDEV:
 125                         fprintf(stderr, "\tdev <devname> ");
 126                         break;
 127                 }
 128                 if (cmd->section)
 129                         fprintf(stderr, "%s ", cmd->section);
 130                 fprintf(stderr, "%s", cmd->name);
 131                 if (cmd->args)
 132                         fprintf(stderr, " %s", cmd->args);
 133                 fprintf(stderr, "\n");
 134         }
 135 }
 136
 137 static void version(void)
 138 {
 139         printf("iw version " IW_VERSION "\n");
 140 }
 141
 142 static int phy_lookup(char *name)
 143 {
 144         char buf[200];
 145         int fd, pos;
 146
 147         snprintf(buf, sizeof(buf), "/sys/class/ieee80211/%s/index", name);
 148
 149         fd = open(buf, O_RDONLY);
 150         if (fd < 0)
 151                 return -1;
 152         pos = read(fd, buf, sizeof(buf) - 1);
 153         if (pos < 0)
 154                 return -1;
 155         buf[pos] = '\0';
 156         return atoi(buf);
 157 }
 158
 159 static int error_handler(struct sockaddr_nl *nla, struct nlmsgerr *err,
 160                          void *arg)
 161 {
 162         int *ret = arg;
 163         *ret = err->error;
 164         return NL_STOP;
 165 }
 166
 167 static int finish_handler(struct nl_msg *msg, void *arg)
 168 {
 169         int *ret = arg;
 170         *ret = 0;
 171         return NL_SKIP;
 172 }
 173
 174 static int ack_handler(struct nl_msg *msg, void *arg)
 175 {
 176         int *ret = arg;
 177         *ret = 0;
 178         return NL_STOP;
 179 }
 180
 181 int handle_cmd(struct nl80211_state *state, enum id_input idby,
 182                int argc, char **argv)
 183 {
 184         struct cmd *cmd, *match = NULL;
 185         struct nl_cb *cb;
 186         struct nl_msg *msg;
 187         int devidx = 0;
 188         int err, o_argc;
 189         const char *command, *section;
 190         char *tmp, **o_argv;
 191         enum command_identify_by command_idby = CIB_NONE;
 192
 193         if (argc <= 1 && idby != II_NONE)
 194                 return 1;
 195
 196         o_argc = argc;
 197         o_argv = argv;
 198
 199         switch (idby) {
 200         case II_PHY_IDX:
 201                 command_idby = CIB_PHY;
 202                 devidx = strtoul(*argv + 4, &tmp, 0);
 203                 if (*tmp != '\0')
 204                         return 1;
 205                 argc--;
 206                 argv++;
 207                 break;
 208         case II_PHY_NAME:
 209                 command_idby = CIB_PHY;
 210                 devidx = phy_lookup(*argv);
 211                 argc--;
 212                 argv++;
 213                 break;
 214         case II_NETDEV:
 215                 command_idby = CIB_NETDEV;
 216                 devidx = if_nametoindex(*argv);
 217                 if (devidx == 0)
 218                         devidx = -1;
 219                 argc--;
 220                 argv++;
 221                 break;
 222         default:
 223                 break;
 224         }
 225
 226         if (devidx < 0)
 227                 return -errno;
 228
 229         section = command = *argv;
 230         argc--;
 231         argv++;
 232
 233         for (cmd = &__start___cmd; cmd < &__stop___cmd;
 234              cmd = (struct cmd *)((char *)cmd + cmd_size)) {
 235                 if (!cmd->handler)
 236                         continue;
 237                 if (cmd->idby != command_idby)
 238                         continue;
 239                 if (cmd->section) {
 240                         if (strcmp(cmd->section, section))
 241                                 continue;
 242                         /* this is a bit icky ... */
 243                         if (command == section) {
 244                                 if (argc <= 0) {
 245                                         if (match)
 246                                                 break;
 247                                         return 1;
 248                                 }
 249                                 command = *argv;
 250                                 argc--;
 251                                 argv++;
 252                         }
 253                 } else if (section != command)
 254                         continue;
 255                 if (strcmp(cmd->name, command))
 256                         continue;
 257                 if (argc && !cmd->args)
 258                         continue;
 259
 260                 match = cmd;
 261         }
 262
 263         cmd = match;
 264
 265         if (!cmd)
 266                 return 1;
 267
 268         if (!cmd->cmd) {
 269                 argc = o_argc;
 270                 argv = o_argv;
 271                 return cmd->handler(state, NULL, NULL, argc, argv);
 272         }
 273
 274         msg = nlmsg_alloc();
 275         if (!msg) {
 276                 fprintf(stderr, "failed to allocate netlink message\n");
 277                 return 2;
 278         }
 279
 280         cb = nl_cb_alloc(debug ? NL_CB_DEBUG : NL_CB_DEFAULT);
 281         if (!cb) {
 282                 fprintf(stderr, "failed to allocate netlink callbacks\n");
 283                 err = 2;
 284                 goto out_free_msg;
 285         }
 286
 287         genlmsg_put(msg, 0, 0, genl_family_get_id(state->nl80211), 0,
 288                     cmd->nl_msg_flags, cmd->cmd, 0);
 289
 290         switch (command_idby) {
 291         case CIB_PHY:
 292                 NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, devidx);
 293                 break;
 294         case CIB_NETDEV:
 295                 NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, devidx);
 296                 break;
 297         default:
 298                 break;
 299         }
 300
 301         err = cmd->handler(state, cb, msg, argc, argv);
 302         if (err)
 303                 goto out;
 304
 305         err = nl_send_auto_complete(state->nl_sock, msg);
 306         if (err < 0)
 307                 goto out;
 308
 309         err = 1;
 310
 311         nl_cb_err(cb, NL_CB_CUSTOM, error_handler, &err);
 312         nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, finish_handler, &err);
 313         nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_handler, &err);
 314
 315         while (err > 0)
 316                 nl_recvmsgs(state->nl_sock, cb);
 317  out:
 318         nl_cb_put(cb);
 319  out_free_msg:
 320         nlmsg_free(msg);
 321         return err;
 322  nla_put_failure:
 323         fprintf(stderr, "building message failed\n");
 324         return 2;
 325 }
 326
 327 static int no_seq_check(struct nl_msg *msg, void *arg)
 328 {
 329         return NL_OK;
 330 }
 331
 332 static int print_event(struct nl_msg *msg, void *arg)
 333 {
 334         struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
 335         struct nlattr *tb[NL80211_ATTR_MAX + 1];
 336         char ifname[100];
 337         __u8 reg_type;
 338
 339         nla_parse(tb, NL80211_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
 340                   genlmsg_attrlen(gnlh, 0), NULL);
 341
 342         switch (gnlh->cmd) {
 343         case NL80211_CMD_NEW_WIPHY:
 344                 printf("wiphy rename: phy #%d to %s\n",
 345                        nla_get_u32(tb[NL80211_ATTR_WIPHY]),
 346                        nla_get_string(tb[NL80211_ATTR_WIPHY_NAME]));
 347                 break;
 348         case NL80211_CMD_NEW_SCAN_RESULTS:
 349                 if_indextoname(nla_get_u32(tb[NL80211_ATTR_IFINDEX]), ifname);
 350                 printf("scan finished on %s (phy #%d)\n",
 351                        ifname, nla_get_u32(tb[NL80211_ATTR_WIPHY]));
 352                 break;
 353         case NL80211_CMD_SCAN_ABORTED:
 354                 if_indextoname(nla_get_u32(tb[NL80211_ATTR_IFINDEX]), ifname);
 355                 printf("scan aborted on %s (phy #%d)\n",
 356                        ifname, nla_get_u32(tb[NL80211_ATTR_WIPHY]));
 357                 break;
 358         case NL80211_CMD_REG_CHANGE:
 359
 360                 printf("regulatory domain change: ");
 361
 362                 reg_type = nla_get_u8(tb[NL80211_ATTR_REG_TYPE]);
 363
 364                 switch (reg_type) {
 365                 case NL80211_REGDOM_TYPE_COUNTRY:
 366                         printf("set to %s by %s request",
 367                                nla_get_string(tb[NL80211_ATTR_REG_ALPHA2]),
 368                                reg_initiator_to_string(nla_get_u8(tb[NL80211_ATTR_REG_INITIATOR])));
 369                         if (tb[NL80211_ATTR_WIPHY])
 370                                 printf(" on phy%d", nla_get_u32(tb[NL80211_ATTR_WIPHY]));
 371                         break;
 372                 case NL80211_REGDOM_TYPE_WORLD:
 373                         printf("set to world roaming by %s request",
 374                                reg_initiator_to_string(nla_get_u8(tb[NL80211_ATTR_REG_INITIATOR])));
 375                         break;
 376                 case NL80211_REGDOM_TYPE_CUSTOM_WORLD:
 377                         printf("custom world roaming rules in place on phy%d by %s request",
 378                                nla_get_u32(tb[NL80211_ATTR_WIPHY]),
 379                                reg_initiator_to_string(nla_get_u32(tb[NL80211_ATTR_REG_INITIATOR])));
 380                         break;
 381                 case NL80211_REGDOM_TYPE_INTERSECTION:
 382                         printf("intersection used due to a request made by %s",
 383                                reg_initiator_to_string(nla_get_u32(tb[NL80211_ATTR_REG_INITIATOR])));
 384                         if (tb[NL80211_ATTR_WIPHY])
 385                                 printf(" on phy%d", nla_get_u32(tb[NL80211_ATTR_WIPHY]));
 386                         break;
 387                 default:
 388                         printf("unknown source (upgrade this utility)");
 389                         break;
 390                 }
 391
 392                 printf("\n");
 393                 break;
 394         default:
 395                 printf("unknown event: %d\n", gnlh->cmd);
 396                 break;
 397         }
 398
 399         return NL_SKIP;
 400 }
 401
 402 struct wait_event {
 403         int n_cmds;
 404         const __u32 *cmds;
 405         __u32 cmd;
 406 };
 407
 408 static int wait_event(struct nl_msg *msg, void *arg)
 409 {
 410         struct wait_event *wait = arg;
 411         struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
 412         int i;
 413
 414         for (i = 0; i < wait->n_cmds; i++) {
 415                 if (gnlh->cmd == wait->cmds[i]) {
 416                         wait->cmd = gnlh->cmd;
 417                 }
 418         }
 419
 420         return NL_SKIP;
 421 }
 422
 423 __u32 listen_events(struct nl80211_state *state,
 424                     const int n_waits, const __u32 *waits)
 425 {
 426         int mcid, ret;
 427         struct nl_cb *cb = nl_cb_alloc(debug ? NL_CB_DEBUG : NL_CB_DEFAULT);
 428         struct wait_event wait_ev;
 429
 430         if (!cb) {
 431                 fprintf(stderr, "failed to allocate netlink callbacks\n");
 432                 return -ENOMEM;
 433         }
 434
 435         /* Configuration multicast group */
 436         mcid = nl_get_multicast_id(state->nl_sock, "nl80211", "config");
 437         if (mcid < 0)
 438                 return mcid;
 439
 440         ret = nl_socket_add_membership(state->nl_sock, mcid);
 441         if (ret)
 442                 return ret;
 443
 444         /* Scan multicast group */
 445         mcid = nl_get_multicast_id(state->nl_sock, "nl80211", "scan");
 446         if (mcid >= 0) {
 447                 ret = nl_socket_add_membership(state->nl_sock, mcid);
 448                 if (ret)
 449                         return ret;
 450         }
 451
 452         /* Regulatory multicast group */
 453         mcid = nl_get_multicast_id(state->nl_sock, "nl80211", "regulatory");
 454         if (mcid >= 0) {
 455                 ret = nl_socket_add_membership(state->nl_sock, mcid);
 456                 if (ret)
 457                         return ret;
 458         }
 459
 460         /* no sequence checking for multicast messages */
 461         nl_cb_set(cb, NL_CB_SEQ_CHECK, NL_CB_CUSTOM, no_seq_check, NULL);
 462
 463         if (n_waits && waits) {
 464                 wait_ev.cmds = waits;
 465                 wait_ev.n_cmds = n_waits;
 466                 nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, wait_event, &wait_ev);
 467         } else {
 468                 nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, print_event, NULL);
 469         }
 470
 471         wait_ev.cmd = 0;
 472
 473         while (!wait_ev.cmd)
 474                 nl_recvmsgs(state->nl_sock, cb);
 475
 476         nl_cb_put(cb);
 477
 478         return wait_ev.cmd;
 479 }
 480
 481 int main(int argc, char **argv)
 482 {
 483         struct nl80211_state nlstate;
 484         int err;
 485         const char *argv0;
 486
 487         /* calculate command size including padding */
 488         cmd_size = abs((long)&__cmd_NULL_1_CIB_NONE_0
 489                      - (long)&__cmd_NULL_0_CIB_NONE_0);
 490         /* strip off self */
 491         argc--;
 492         argv0 = *argv++;
 493
 494         if (argc > 0 && strcmp(*argv, "--debug") == 0) {
 495                 debug = 1;
 496                 argc--;
 497                 argv++;
 498         }
 499
 500         if (argc > 0 && strcmp(*argv, "--version") == 0) {
 501                 version();
 502                 return 0;
 503         }
 504
 505         if (argc == 0 || strcmp(*argv, "help") == 0) {
 506                 usage(argv0);
 507                 return 0;
 508         }
 509
 510         err = nl80211_init(&nlstate);
 511         if (err)
 512                 return 1;
 513
 514         if (strcmp(*argv, "event") == 0) {
 515                 if (argc != 1)
 516                         err = 1;
 517                 else
 518                         err = listen_events(&nlstate, 0, NULL);
 519         } else if (strcmp(*argv, "dev") == 0) {
 520                 argc--;
 521                 argv++;
 522                 err = handle_cmd(&nlstate, II_NETDEV, argc, argv);
 523         } else if (strncmp(*argv, "phy", 3) == 0) {
 524                 if (strlen(*argv) == 3) {
 525                         argc--;
 526                         argv++;
 527                         err = handle_cmd(&nlstate, II_PHY_NAME, argc, argv);
 528                 } else if (*(*argv + 3) == '#')
 529                         err = handle_cmd(&nlstate, II_PHY_IDX, argc, argv);
 530                 else
 531                         err = 1;
 532         } else
 533                 err = handle_cmd(&nlstate, II_NONE, argc, argv);
 534
 535         if (err == 1)
 536                 usage(argv0);
 537         if (err < 0)
 538                 fprintf(stderr, "command failed: %s (%d)\n", strerror(-err), err);
 539
 540         nl80211_cleanup(&nlstate);
 541
 542         return err;
 543 }