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 #include <stdbool.h>
  16
  17 #include <netlink/genl/genl.h>
  18 #include <netlink/genl/family.h>
  19 #include <netlink/genl/ctrl.h>
  20 #include <netlink/msg.h>
  21 #include <netlink/attr.h>
  22
  23 #include "nl80211.h"
  24 #include "iw.h"
  25
  26 /* libnl 1.x compatibility code */
  27 #if !defined(CONFIG_LIBNL20) && !defined(CONFIG_LIBNL30)
  28 static inline struct nl_handle *nl_socket_alloc(void)
  29 {
  30         return nl_handle_alloc();
  31 }
  32
  33 static inline void nl_socket_free(struct nl_sock *h)
  34 {
  35         nl_handle_destroy(h);
  36 }
  37 #endif /* CONFIG_LIBNL20 && CONFIG_LIBNL30 */
  38
  39 int iw_debug = 0;
  40
  41 static int nl80211_init(struct nl80211_state *state)
  42 {
  43         int err;
  44
  45         state->nl_sock = nl_socket_alloc();
  46         if (!state->nl_sock) {
  47                 fprintf(stderr, "Failed to allocate netlink socket.\n");
  48                 return -ENOMEM;
  49         }
  50
  51         if (genl_connect(state->nl_sock)) {
  52                 fprintf(stderr, "Failed to connect to generic netlink.\n");
  53                 err = -ENOLINK;
  54                 goto out_handle_destroy;
  55         }
  56
  57         state->nl80211_id = genl_ctrl_resolve(state->nl_sock, "nl80211");
  58         if (state->nl80211_id < 0) {
  59                 fprintf(stderr, "nl80211 not found.\n");
  60                 err = -ENOENT;
  61                 goto out_handle_destroy;
  62         }
  63
  64         return 0;
  65
  66  out_handle_destroy:
  67         nl_socket_free(state->nl_sock);
  68         return err;
  69 }
  70
  71 static void nl80211_cleanup(struct nl80211_state *state)
  72 {
  73         nl_socket_free(state->nl_sock);
  74 }
  75
  76 static int cmd_size;
  77
  78 extern struct cmd __start___cmd;
  79 extern struct cmd __stop___cmd;
  80
  81 #define for_each_cmd(_cmd)                                      \
  82         for (_cmd = &__start___cmd; _cmd < &__stop___cmd;               \
  83              _cmd = (const struct cmd *)((char *)_cmd + cmd_size))
  84
  85
  86 static void __usage_cmd(const struct cmd *cmd, char *indent, bool full)
  87 {
  88         const char *start, *lend, *end;
  89
  90         printf("%s", indent);
  91
  92         switch (cmd->idby) {
  93         case CIB_NONE:
  94                 break;
  95         case CIB_PHY:
  96                 printf("phy <phyname> ");
  97                 break;
  98         case CIB_NETDEV:
  99                 printf("dev <devname> ");
 100                 break;
 101         case CIB_WDEV:
 102                 printf("wdev <idx> ");
 103                 break;
 104         }
 105         if (cmd->parent && cmd->parent->name)
 106                 printf("%s ", cmd->parent->name);
 107         printf("%s", cmd->name);
 108         if (cmd->args)
 109                 printf(" %s", cmd->args);
 110         printf("\n");
 111
 112         if (!full || !cmd->help)
 113                 return;
 114
 115         /* hack */
 116         if (strlen(indent))
 117                 indent = "\t\t";
 118         else
 119                 printf("\n");
 120
 121         /* print line by line */
 122         start = cmd->help;
 123         end = strchr(start, '\0');
 124         do {
 125                 lend = strchr(start, '\n');
 126                 if (!lend)
 127                         lend = end;
 128                 printf("%s", indent);
 129                 printf("%.*s\n", (int)(lend - start), start);
 130                 start = lend + 1;
 131         } while (end != lend);
 132
 133         printf("\n");
 134 }
 135
 136 static void usage_options(void)
 137 {
 138         printf("Options:\n");
 139         printf("\t--debug\t\tenable netlink debugging\n");
 140 }
 141
 142 static const char *argv0;
 143
 144 static void usage(int argc, char **argv)
 145 {
 146         const struct cmd *section, *cmd;
 147         bool full = argc >= 0;
 148         const char *sect_filt = NULL;
 149         const char *cmd_filt = NULL;
 150
 151         if (argc > 0)
 152                 sect_filt = argv[0];
 153
 154         if (argc > 1)
 155                 cmd_filt = argv[1];
 156
 157         printf("Usage:\t%s [options] command\n", argv0);
 158         usage_options();
 159         printf("\t--version\tshow version (%s)\n", iw_version);
 160         printf("Commands:\n");
 161         for_each_cmd(section) {
 162                 if (section->parent)
 163                         continue;
 164
 165                 if (sect_filt && strcmp(section->name, sect_filt))
 166                         continue;
 167
 168                 if (section->handler && !section->hidden)
 169                         __usage_cmd(section, "\t", full);
 170
 171                 for_each_cmd(cmd) {
 172                         if (section != cmd->parent)
 173                                 continue;
 174                         if (!cmd->handler || cmd->hidden)
 175                                 continue;
 176                         if (cmd_filt && strcmp(cmd->name, cmd_filt))
 177                                 continue;
 178                         __usage_cmd(cmd, "\t", full);
 179                 }
 180         }
 181         printf("\nYou can omit the 'phy' or 'dev' if "
 182                         "the identification is unique,\n"
 183                         "e.g. \"iw wlan0 info\" or \"iw phy0 info\". "
 184                         "(Don't when scripting.)\n\n"
 185                         "Do NOT screenscrape this tool, we don't "
 186                         "consider its output stable.\n\n");
 187 }
 188
 189 static int print_help(struct nl80211_state *state,
 190                       struct nl_cb *cb,
 191                       struct nl_msg *msg,
 192                       int argc, char **argv,
 193                       enum id_input id)
 194 {
 195         exit(3);
 196 }
 197 TOPLEVEL(help, "[command]", 0, 0, CIB_NONE, print_help,
 198          "Print usage for all or a specific command, e.g.\n"
 199          "\"help wowlan\" or \"help wowlan enable\".");
 200
 201 static void usage_cmd(const struct cmd *cmd)
 202 {
 203         printf("Usage:\t%s [options] ", argv0);
 204         __usage_cmd(cmd, "", true);
 205         usage_options();
 206 }
 207
 208 static void version(void)
 209 {
 210         printf("iw version %s\n", iw_version);
 211 }
 212
 213 static int phy_lookup(char *name)
 214 {
 215         char buf[200];
 216         int fd, pos;
 217
 218         snprintf(buf, sizeof(buf), "/sys/class/ieee80211/%s/index", name);
 219
 220         fd = open(buf, O_RDONLY);
 221         if (fd < 0)
 222                 return -1;
 223         pos = read(fd, buf, sizeof(buf) - 1);
 224         if (pos < 0) {
 225                 close(fd);
 226                 return -1;
 227         }
 228         buf[pos] = '\0';
 229         close(fd);
 230         return atoi(buf);
 231 }
 232
 233 static int error_handler(struct sockaddr_nl *nla, struct nlmsgerr *err,
 234                          void *arg)
 235 {
 236         int *ret = arg;
 237         *ret = err->error;
 238         return NL_STOP;
 239 }
 240
 241 static int finish_handler(struct nl_msg *msg, void *arg)
 242 {
 243         int *ret = arg;
 244         *ret = 0;
 245         return NL_SKIP;
 246 }
 247
 248 static int ack_handler(struct nl_msg *msg, void *arg)
 249 {
 250         int *ret = arg;
 251         *ret = 0;
 252         return NL_STOP;
 253 }
 254
 255 static int __handle_cmd(struct nl80211_state *state, enum id_input idby,
 256                         int argc, char **argv, const struct cmd **cmdout)
 257 {
 258         const struct cmd *cmd, *match = NULL, *sectcmd;
 259         struct nl_cb *cb;
 260         struct nl_cb *s_cb;
 261         struct nl_msg *msg;
 262         signed long long devidx = 0;
 263         int err, o_argc;
 264         const char *command, *section;
 265         char *tmp, **o_argv;
 266         enum command_identify_by command_idby = CIB_NONE;
 267
 268         if (argc <= 1 && idby != II_NONE)
 269                 return 1;
 270
 271         o_argc = argc;
 272         o_argv = argv;
 273
 274         switch (idby) {
 275         case II_PHY_IDX:
 276                 command_idby = CIB_PHY;
 277                 devidx = strtoul(*argv + 4, &tmp, 0);
 278                 if (*tmp != '\0')
 279                         return 1;
 280                 argc--;
 281                 argv++;
 282                 break;
 283         case II_PHY_NAME:
 284                 command_idby = CIB_PHY;
 285                 devidx = phy_lookup(*argv);
 286                 argc--;
 287                 argv++;
 288                 break;
 289         case II_NETDEV:
 290                 command_idby = CIB_NETDEV;
 291                 devidx = if_nametoindex(*argv);
 292                 if (devidx == 0)
 293                         devidx = -1;
 294                 argc--;
 295                 argv++;
 296                 break;
 297         case II_WDEV:
 298                 command_idby = CIB_WDEV;
 299                 devidx = strtoll(*argv, &tmp, 0);
 300                 if (*tmp != '\0')
 301                         return 1;
 302                 argc--;
 303                 argv++;
 304         default:
 305                 break;
 306         }
 307
 308         if (devidx < 0)
 309                 return -errno;
 310
 311         section = *argv;
 312         argc--;
 313         argv++;
 314
 315         for_each_cmd(sectcmd) {
 316                 if (sectcmd->parent)
 317                         continue;
 318                 /* ok ... bit of a hack for the dupe 'info' section */
 319                 if (match && sectcmd->idby != command_idby)
 320                         continue;
 321                 if (strcmp(sectcmd->name, section) == 0)
 322                         match = sectcmd;
 323         }
 324
 325         sectcmd = match;
 326         match = NULL;
 327         if (!sectcmd)
 328                 return 1;
 329
 330         if (argc > 0) {
 331                 command = *argv;
 332
 333                 for_each_cmd(cmd) {
 334                         if (!cmd->handler)
 335                                 continue;
 336                         if (cmd->parent != sectcmd)
 337                                 continue;
 338                         if (cmd->idby != command_idby)
 339                                 continue;
 340                         if (strcmp(cmd->name, command))
 341                                 continue;
 342                         if (argc > 1 && !cmd->args)
 343                                 continue;
 344                         match = cmd;
 345                         break;
 346                 }
 347
 348                 if (match) {
 349                         argc--;
 350                         argv++;
 351                 }
 352         }
 353
 354         if (match)
 355                 cmd = match;
 356         else {
 357                 /* Use the section itself, if possible. */
 358                 cmd = sectcmd;
 359                 if (argc && !cmd->args)
 360                         return 1;
 361                 if (cmd->idby != command_idby)
 362                         return 1;
 363                 if (!cmd->handler)
 364                         return 1;
 365         }
 366
 367         if (cmd->selector) {
 368                 cmd = cmd->selector(argc, argv);
 369                 if (!cmd)
 370                         return 1;
 371         }
 372
 373         if (cmdout)
 374                 *cmdout = cmd;
 375
 376         if (!cmd->cmd) {
 377                 argc = o_argc;
 378                 argv = o_argv;
 379                 return cmd->handler(state, NULL, NULL, argc, argv, idby);
 380         }
 381
 382         msg = nlmsg_alloc();
 383         if (!msg) {
 384                 fprintf(stderr, "failed to allocate netlink message\n");
 385                 return 2;
 386         }
 387
 388         cb = nl_cb_alloc(iw_debug ? NL_CB_DEBUG : NL_CB_DEFAULT);
 389         s_cb = nl_cb_alloc(iw_debug ? NL_CB_DEBUG : NL_CB_DEFAULT);
 390         if (!cb || !s_cb) {
 391                 fprintf(stderr, "failed to allocate netlink callbacks\n");
 392                 err = 2;
 393                 goto out_free_msg;
 394         }
 395
 396         genlmsg_put(msg, 0, 0, state->nl80211_id, 0,
 397                     cmd->nl_msg_flags, cmd->cmd, 0);
 398
 399         switch (command_idby) {
 400         case CIB_PHY:
 401                 NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, devidx);
 402                 break;
 403         case CIB_NETDEV:
 404                 NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, devidx);
 405                 break;
 406         case CIB_WDEV:
 407                 NLA_PUT_U64(msg, NL80211_ATTR_WDEV, devidx);
 408                 break;
 409         default:
 410                 break;
 411         }
 412
 413         err = cmd->handler(state, cb, msg, argc, argv, idby);
 414         if (err)
 415                 goto out;
 416
 417         nl_socket_set_cb(state->nl_sock, s_cb);
 418
 419         err = nl_send_auto_complete(state->nl_sock, msg);
 420         if (err < 0)
 421                 goto out;
 422
 423         err = 1;
 424
 425         nl_cb_err(cb, NL_CB_CUSTOM, error_handler, &err);
 426         nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, finish_handler, &err);
 427         nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_handler, &err);
 428
 429         while (err > 0)
 430                 nl_recvmsgs(state->nl_sock, cb);
 431  out:
 432         nl_cb_put(cb);
 433  out_free_msg:
 434         nlmsg_free(msg);
 435         return err;
 436  nla_put_failure:
 437         fprintf(stderr, "building message failed\n");
 438         return 2;
 439 }
 440
 441 int handle_cmd(struct nl80211_state *state, enum id_input idby,
 442                int argc, char **argv)
 443 {
 444         return __handle_cmd(state, idby, argc, argv, NULL);
 445 }
 446
 447 int main(int argc, char **argv)
 448 {
 449         struct nl80211_state nlstate;
 450         int err;
 451         const struct cmd *cmd = NULL;
 452
 453         /* calculate command size including padding */
 454         cmd_size = abs((long)&__section_set - (long)&__section_get);
 455         /* strip off self */
 456         argc--;
 457         argv0 = *argv++;
 458
 459         if (argc > 0 && strcmp(*argv, "--debug") == 0) {
 460                 iw_debug = 1;
 461                 argc--;
 462                 argv++;
 463         }
 464
 465         if (argc > 0 && strcmp(*argv, "--version") == 0) {
 466                 version();
 467                 return 0;
 468         }
 469
 470         /* need to treat "help" command specially so it works w/o nl80211 */
 471         if (argc == 0 || strcmp(*argv, "help") == 0) {
 472                 usage(argc - 1, argv + 1);
 473                 return 0;
 474         }
 475
 476         err = nl80211_init(&nlstate);
 477         if (err)
 478                 return 1;
 479
 480         if (strcmp(*argv, "dev") == 0 && argc > 1) {
 481                 argc--;
 482                 argv++;
 483                 err = __handle_cmd(&nlstate, II_NETDEV, argc, argv, &cmd);
 484         } else if (strncmp(*argv, "phy", 3) == 0 && argc > 1) {
 485                 if (strlen(*argv) == 3) {
 486                         argc--;
 487                         argv++;
 488                         err = __handle_cmd(&nlstate, II_PHY_NAME, argc, argv, &cmd);
 489                 } else if (*(*argv + 3) == '#')
 490                         err = __handle_cmd(&nlstate, II_PHY_IDX, argc, argv, &cmd);
 491                 else
 492                         goto detect;
 493         } else if (strcmp(*argv, "wdev") == 0 && argc > 1) {
 494                 argc--;
 495                 argv++;
 496                 err = __handle_cmd(&nlstate, II_WDEV, argc, argv, &cmd);
 497         } else {
 498                 int idx;
 499                 enum id_input idby = II_NONE;
 500  detect:
 501                 if ((idx = if_nametoindex(argv[0])) != 0)
 502                         idby = II_NETDEV;
 503                 else if ((idx = phy_lookup(argv[0])) >= 0)
 504                         idby = II_PHY_NAME;
 505                 err = __handle_cmd(&nlstate, idby, argc, argv, &cmd);
 506         }
 507
 508         if (err == 1) {
 509                 if (cmd)
 510                         usage_cmd(cmd);
 511                 else
 512                         usage(0, NULL);
 513         } else if (err < 0)
 514                 fprintf(stderr, "command failed: %s (%d)\n", strerror(-err), err);
 515
 516         nl80211_cleanup(&nlstate);
 517
 518         return err;
 519 }