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
  38 static inline int nl_socket_set_buffer_size(struct nl_sock *sk,
  39                                             int rxbuf, int txbuf)
  40 {
  41         return nl_set_buffer_size(sk, rxbuf, txbuf);
  42 }
  43 #endif /* CONFIG_LIBNL20 && CONFIG_LIBNL30 */
  44
  45 int iw_debug = 0;
  46
  47 static int nl80211_init(struct nl80211_state *state)
  48 {
  49         int err;
  50
  51         state->nl_sock = nl_socket_alloc();
  52         if (!state->nl_sock) {
  53                 fprintf(stderr, "Failed to allocate netlink socket.\n");
  54                 return -ENOMEM;
  55         }
  56
  57         nl_socket_set_buffer_size(state->nl_sock, 8192, 8192);
  58
  59         if (genl_connect(state->nl_sock)) {
  60                 fprintf(stderr, "Failed to connect to generic netlink.\n");
  61                 err = -ENOLINK;
  62                 goto out_handle_destroy;
  63         }
  64
  65         state->nl80211_id = genl_ctrl_resolve(state->nl_sock, "nl80211");
  66         if (state->nl80211_id < 0) {
  67                 fprintf(stderr, "nl80211 not found.\n");
  68                 err = -ENOENT;
  69                 goto out_handle_destroy;
  70         }
  71
  72         return 0;
  73
  74  out_handle_destroy:
  75         nl_socket_free(state->nl_sock);
  76         return err;
  77 }
  78
  79 static void nl80211_cleanup(struct nl80211_state *state)
  80 {
  81         nl_socket_free(state->nl_sock);
  82 }
  83
  84 static int cmd_size;
  85
  86 extern struct cmd __start___cmd;
  87 extern struct cmd __stop___cmd;
  88
  89 #define for_each_cmd(_cmd)                                      \
  90         for (_cmd = &__start___cmd; _cmd < &__stop___cmd;               \
  91              _cmd = (const struct cmd *)((char *)_cmd + cmd_size))
  92
  93
  94 static void __usage_cmd(const struct cmd *cmd, char *indent, bool full)
  95 {
  96         const char *start, *lend, *end;
  97
  98         printf("%s", indent);
  99
 100         switch (cmd->idby) {
 101         case CIB_NONE:
 102                 break;
 103         case CIB_PHY:
 104                 printf("phy <phyname> ");
 105                 break;
 106         case CIB_NETDEV:
 107                 printf("dev <devname> ");
 108                 break;
 109         case CIB_WDEV:
 110                 printf("wdev <idx> ");
 111                 break;
 112         }
 113         if (cmd->parent && cmd->parent->name)
 114                 printf("%s ", cmd->parent->name);
 115         printf("%s", cmd->name);
 116
 117         if (cmd->args) {
 118                 /* print line by line */
 119                 start = cmd->args;
 120                 end = strchr(start, '\0');
 121                 printf(" ");
 122                 do {
 123                         lend = strchr(start, '\n');
 124                         if (!lend)
 125                                 lend = end;
 126                         if (start != cmd->args) {
 127                                 printf("\t");
 128                                 switch (cmd->idby) {
 129                                 case CIB_NONE:
 130                                         break;
 131                                 case CIB_PHY:
 132                                         printf("phy <phyname> ");
 133                                         break;
 134                                 case CIB_NETDEV:
 135                                         printf("dev <devname> ");
 136                                         break;
 137                                 case CIB_WDEV:
 138                                         printf("wdev <idx> ");
 139                                         break;
 140                                 }
 141                                 if (cmd->parent && cmd->parent->name)
 142                                         printf("%s ", cmd->parent->name);
 143                                 printf("%s ", cmd->name);
 144                         }
 145                         printf("%.*s\n", (int)(lend - start), start);
 146                         start = lend + 1;
 147                 } while (end != lend);
 148         } else
 149                 printf("\n");
 150
 151         if (!full || !cmd->help)
 152                 return;
 153
 154         /* hack */
 155         if (strlen(indent))
 156                 indent = "\t\t";
 157         else
 158                 printf("\n");
 159
 160         /* print line by line */
 161         start = cmd->help;
 162         end = strchr(start, '\0');
 163         do {
 164                 lend = strchr(start, '\n');
 165                 if (!lend)
 166                         lend = end;
 167                 printf("%s", indent);
 168                 printf("%.*s\n", (int)(lend - start), start);
 169                 start = lend + 1;
 170         } while (end != lend);
 171
 172         printf("\n");
 173 }
 174
 175 static void usage_options(void)
 176 {
 177         printf("Options:\n");
 178         printf("\t--debug\t\tenable netlink debugging\n");
 179 }
 180
 181 static const char *argv0;
 182
 183 static void usage(int argc, char **argv)
 184 {
 185         const struct cmd *section, *cmd;
 186         bool full = argc >= 0;
 187         const char *sect_filt = NULL;
 188         const char *cmd_filt = NULL;
 189
 190         if (argc > 0)
 191                 sect_filt = argv[0];
 192
 193         if (argc > 1)
 194                 cmd_filt = argv[1];
 195
 196         printf("Usage:\t%s [options] command\n", argv0);
 197         usage_options();
 198         printf("\t--version\tshow version (%s)\n", iw_version);
 199         printf("Commands:\n");
 200         for_each_cmd(section) {
 201                 if (section->parent)
 202                         continue;
 203
 204                 if (sect_filt && strcmp(section->name, sect_filt))
 205                         continue;
 206
 207                 if (section->handler && !section->hidden)
 208                         __usage_cmd(section, "\t", full);
 209
 210                 for_each_cmd(cmd) {
 211                         if (section != cmd->parent)
 212                                 continue;
 213                         if (!cmd->handler || cmd->hidden)
 214                                 continue;
 215                         if (cmd_filt && strcmp(cmd->name, cmd_filt))
 216                                 continue;
 217                         __usage_cmd(cmd, "\t", full);
 218                 }
 219         }
 220         printf("\nCommands that use the netdev ('dev') can also be given the\n"
 221                "'wdev' instead to identify the device.\n");
 222         printf("\nYou can omit the 'phy' or 'dev' if "
 223                         "the identification is unique,\n"
 224                         "e.g. \"iw wlan0 info\" or \"iw phy0 info\". "
 225                         "(Don't when scripting.)\n\n"
 226                         "Do NOT screenscrape this tool, we don't "
 227                         "consider its output stable.\n\n");
 228 }
 229
 230 static int print_help(struct nl80211_state *state,
 231                       struct nl_cb *cb,
 232                       struct nl_msg *msg,
 233                       int argc, char **argv,
 234                       enum id_input id)
 235 {
 236         exit(3);
 237 }
 238 TOPLEVEL(help, "[command]", 0, 0, CIB_NONE, print_help,
 239          "Print usage for all or a specific command, e.g.\n"
 240          "\"help wowlan\" or \"help wowlan enable\".");
 241
 242 static void usage_cmd(const struct cmd *cmd)
 243 {
 244         printf("Usage:\t%s [options] ", argv0);
 245         __usage_cmd(cmd, "", true);
 246         usage_options();
 247 }
 248
 249 static void version(void)
 250 {
 251         printf("iw version %s\n", iw_version);
 252 }
 253
 254 static int phy_lookup(char *name)
 255 {
 256         char buf[200];
 257         int fd, pos;
 258
 259         snprintf(buf, sizeof(buf), "/sys/class/ieee80211/%s/index", name);
 260
 261         fd = open(buf, O_RDONLY);
 262         if (fd < 0)
 263                 return -1;
 264         pos = read(fd, buf, sizeof(buf) - 1);
 265         if (pos < 0) {
 266                 close(fd);
 267                 return -1;
 268         }
 269         buf[pos] = '\0';
 270         close(fd);
 271         return atoi(buf);
 272 }
 273
 274 static int error_handler(struct sockaddr_nl *nla, struct nlmsgerr *err,
 275                          void *arg)
 276 {
 277         int *ret = arg;
 278         *ret = err->error;
 279         return NL_STOP;
 280 }
 281
 282 static int finish_handler(struct nl_msg *msg, void *arg)
 283 {
 284         int *ret = arg;
 285         *ret = 0;
 286         return NL_SKIP;
 287 }
 288
 289 static int ack_handler(struct nl_msg *msg, void *arg)
 290 {
 291         int *ret = arg;
 292         *ret = 0;
 293         return NL_STOP;
 294 }
 295
 296 static int __handle_cmd(struct nl80211_state *state, enum id_input idby,
 297                         int argc, char **argv, const struct cmd **cmdout)
 298 {
 299         const struct cmd *cmd, *match = NULL, *sectcmd;
 300         struct nl_cb *cb;
 301         struct nl_cb *s_cb;
 302         struct nl_msg *msg;
 303         signed long long devidx = 0;
 304         int err, o_argc;
 305         const char *command, *section;
 306         char *tmp, **o_argv;
 307         enum command_identify_by command_idby = CIB_NONE;
 308
 309         if (argc <= 1 && idby != II_NONE)
 310                 return 1;
 311
 312         o_argc = argc;
 313         o_argv = argv;
 314
 315         switch (idby) {
 316         case II_PHY_IDX:
 317                 command_idby = CIB_PHY;
 318                 devidx = strtoul(*argv + 4, &tmp, 0);
 319                 if (*tmp != '\0')
 320                         return 1;
 321                 argc--;
 322                 argv++;
 323                 break;
 324         case II_PHY_NAME:
 325                 command_idby = CIB_PHY;
 326                 devidx = phy_lookup(*argv);
 327                 argc--;
 328                 argv++;
 329                 break;
 330         case II_NETDEV:
 331                 command_idby = CIB_NETDEV;
 332                 devidx = if_nametoindex(*argv);
 333                 if (devidx == 0)
 334                         devidx = -1;
 335                 argc--;
 336                 argv++;
 337                 break;
 338         case II_WDEV:
 339                 command_idby = CIB_WDEV;
 340                 devidx = strtoll(*argv, &tmp, 0);
 341                 if (*tmp != '\0')
 342                         return 1;
 343                 argc--;
 344                 argv++;
 345         default:
 346                 break;
 347         }
 348
 349         if (devidx < 0)
 350                 return -errno;
 351
 352         section = *argv;
 353         argc--;
 354         argv++;
 355
 356         for_each_cmd(sectcmd) {
 357                 if (sectcmd->parent)
 358                         continue;
 359                 /* ok ... bit of a hack for the dupe 'info' section */
 360                 if (match && sectcmd->idby != command_idby)
 361                         continue;
 362                 if (strcmp(sectcmd->name, section) == 0)
 363                         match = sectcmd;
 364         }
 365
 366         sectcmd = match;
 367         match = NULL;
 368         if (!sectcmd)
 369                 return 1;
 370
 371         if (argc > 0) {
 372                 command = *argv;
 373
 374                 for_each_cmd(cmd) {
 375                         if (!cmd->handler)
 376                                 continue;
 377                         if (cmd->parent != sectcmd)
 378                                 continue;
 379                         /*
 380                          * ignore mismatch id by, but allow WDEV
 381                          * in place of NETDEV
 382                          */
 383                         if (cmd->idby != command_idby &&
 384                             !(cmd->idby == CIB_NETDEV &&
 385                               command_idby == CIB_WDEV))
 386                                 continue;
 387                         if (strcmp(cmd->name, command))
 388                                 continue;
 389                         if (argc > 1 && !cmd->args)
 390                                 continue;
 391                         match = cmd;
 392                         break;
 393                 }
 394
 395                 if (match) {
 396                         argc--;
 397                         argv++;
 398                 }
 399         }
 400
 401         if (match)
 402                 cmd = match;
 403         else {
 404                 /* Use the section itself, if possible. */
 405                 cmd = sectcmd;
 406                 if (argc && !cmd->args)
 407                         return 1;
 408                 if (cmd->idby != command_idby &&
 409                     !(cmd->idby == CIB_NETDEV && command_idby == CIB_WDEV))
 410                         return 1;
 411                 if (!cmd->handler)
 412                         return 1;
 413         }
 414
 415         if (cmd->selector) {
 416                 cmd = cmd->selector(argc, argv);
 417                 if (!cmd)
 418                         return 1;
 419         }
 420
 421         if (cmdout)
 422                 *cmdout = cmd;
 423
 424         if (!cmd->cmd) {
 425                 argc = o_argc;
 426                 argv = o_argv;
 427                 return cmd->handler(state, NULL, NULL, argc, argv, idby);
 428         }
 429
 430         msg = nlmsg_alloc();
 431         if (!msg) {
 432                 fprintf(stderr, "failed to allocate netlink message\n");
 433                 return 2;
 434         }
 435
 436         cb = nl_cb_alloc(iw_debug ? NL_CB_DEBUG : NL_CB_DEFAULT);
 437         s_cb = nl_cb_alloc(iw_debug ? NL_CB_DEBUG : NL_CB_DEFAULT);
 438         if (!cb || !s_cb) {
 439                 fprintf(stderr, "failed to allocate netlink callbacks\n");
 440                 err = 2;
 441                 goto out_free_msg;
 442         }
 443
 444         genlmsg_put(msg, 0, 0, state->nl80211_id, 0,
 445                     cmd->nl_msg_flags, cmd->cmd, 0);
 446
 447         switch (command_idby) {
 448         case CIB_PHY:
 449                 NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, devidx);
 450                 break;
 451         case CIB_NETDEV:
 452                 NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, devidx);
 453                 break;
 454         case CIB_WDEV:
 455                 NLA_PUT_U64(msg, NL80211_ATTR_WDEV, devidx);
 456                 break;
 457         default:
 458                 break;
 459         }
 460
 461         err = cmd->handler(state, cb, msg, argc, argv, idby);
 462         if (err)
 463                 goto out;
 464
 465         nl_socket_set_cb(state->nl_sock, s_cb);
 466
 467         err = nl_send_auto_complete(state->nl_sock, msg);
 468         if (err < 0)
 469                 goto out;
 470
 471         err = 1;
 472
 473         nl_cb_err(cb, NL_CB_CUSTOM, error_handler, &err);
 474         nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, finish_handler, &err);
 475         nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_handler, &err);
 476
 477         while (err > 0)
 478                 nl_recvmsgs(state->nl_sock, cb);
 479  out:
 480         nl_cb_put(cb);
 481  out_free_msg:
 482         nlmsg_free(msg);
 483         return err;
 484  nla_put_failure:
 485         fprintf(stderr, "building message failed\n");
 486         return 2;
 487 }
 488
 489 int handle_cmd(struct nl80211_state *state, enum id_input idby,
 490                int argc, char **argv)
 491 {
 492         return __handle_cmd(state, idby, argc, argv, NULL);
 493 }
 494
 495 int main(int argc, char **argv)
 496 {
 497         struct nl80211_state nlstate;
 498         int err;
 499         const struct cmd *cmd = NULL;
 500
 501         /* calculate command size including padding */
 502         cmd_size = abs((long)&__section_set - (long)&__section_get);
 503         /* strip off self */
 504         argc--;
 505         argv0 = *argv++;
 506
 507         if (argc > 0 && strcmp(*argv, "--debug") == 0) {
 508                 iw_debug = 1;
 509                 argc--;
 510                 argv++;
 511         }
 512
 513         if (argc > 0 && strcmp(*argv, "--version") == 0) {
 514                 version();
 515                 return 0;
 516         }
 517
 518         /* need to treat "help" command specially so it works w/o nl80211 */
 519         if (argc == 0 || strcmp(*argv, "help") == 0) {
 520                 usage(argc - 1, argv + 1);
 521                 return 0;
 522         }
 523
 524         err = nl80211_init(&nlstate);
 525         if (err)
 526                 return 1;
 527
 528         if (strcmp(*argv, "dev") == 0 && argc > 1) {
 529                 argc--;
 530                 argv++;
 531                 err = __handle_cmd(&nlstate, II_NETDEV, argc, argv, &cmd);
 532         } else if (strncmp(*argv, "phy", 3) == 0 && argc > 1) {
 533                 if (strlen(*argv) == 3) {
 534                         argc--;
 535                         argv++;
 536                         err = __handle_cmd(&nlstate, II_PHY_NAME, argc, argv, &cmd);
 537                 } else if (*(*argv + 3) == '#')
 538                         err = __handle_cmd(&nlstate, II_PHY_IDX, argc, argv, &cmd);
 539                 else
 540                         goto detect;
 541         } else if (strcmp(*argv, "wdev") == 0 && argc > 1) {
 542                 argc--;
 543                 argv++;
 544                 err = __handle_cmd(&nlstate, II_WDEV, argc, argv, &cmd);
 545         } else {
 546                 int idx;
 547                 enum id_input idby = II_NONE;
 548  detect:
 549                 if ((idx = if_nametoindex(argv[0])) != 0)
 550                         idby = II_NETDEV;
 551                 else if ((idx = phy_lookup(argv[0])) >= 0)
 552                         idby = II_PHY_NAME;
 553                 err = __handle_cmd(&nlstate, idby, argc, argv, &cmd);
 554         }
 555
 556         if (err == 1) {
 557                 if (cmd)
 558                         usage_cmd(cmd);
 559                 else
 560                         usage(0, NULL);
 561         } else if (err < 0)
 562                 fprintf(stderr, "command failed: %s (%d)\n", strerror(-err), err);
 563
 564         nl80211_cleanup(&nlstate);
 565
 566         return err;
 567 }