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 {
 194         exit(3);
 195 }
 196 TOPLEVEL(help, "[command]", 0, 0, CIB_NONE, print_help,
 197          "Print usage for all or a specific command, e.g.\n"
 198          "\"help wowlan\" or \"help wowlan enable\".");
 199
 200 static void usage_cmd(const struct cmd *cmd)
 201 {
 202         printf("Usage:\t%s [options] ", argv0);
 203         __usage_cmd(cmd, "", true);
 204         usage_options();
 205 }
 206
 207 static void version(void)
 208 {
 209         printf("iw version %s\n", iw_version);
 210 }
 211
 212 static int phy_lookup(char *name)
 213 {
 214         char buf[200];
 215         int fd, pos;
 216
 217         snprintf(buf, sizeof(buf), "/sys/class/ieee80211/%s/index", name);
 218
 219         fd = open(buf, O_RDONLY);
 220         if (fd < 0)
 221                 return -1;
 222         pos = read(fd, buf, sizeof(buf) - 1);
 223         if (pos < 0) {
 224                 close(fd);
 225                 return -1;
 226         }
 227         buf[pos] = '\0';
 228         close(fd);
 229         return atoi(buf);
 230 }
 231
 232 static int error_handler(struct sockaddr_nl *nla, struct nlmsgerr *err,
 233                          void *arg)
 234 {
 235         int *ret = arg;
 236         *ret = err->error;
 237         return NL_STOP;
 238 }
 239
 240 static int finish_handler(struct nl_msg *msg, void *arg)
 241 {
 242         int *ret = arg;
 243         *ret = 0;
 244         return NL_SKIP;
 245 }
 246
 247 static int ack_handler(struct nl_msg *msg, void *arg)
 248 {
 249         int *ret = arg;
 250         *ret = 0;
 251         return NL_STOP;
 252 }
 253
 254 static int __handle_cmd(struct nl80211_state *state, enum id_input idby,
 255                         int argc, char **argv, const struct cmd **cmdout)
 256 {
 257         const struct cmd *cmd, *match = NULL, *sectcmd;
 258         struct nl_cb *cb;
 259         struct nl_cb *s_cb;
 260         struct nl_msg *msg;
 261         signed long long devidx = 0;
 262         int err, o_argc;
 263         const char *command, *section;
 264         char *tmp, **o_argv;
 265         enum command_identify_by command_idby = CIB_NONE;
 266
 267         if (argc <= 1 && idby != II_NONE)
 268                 return 1;
 269
 270         o_argc = argc;
 271         o_argv = argv;
 272
 273         switch (idby) {
 274         case II_PHY_IDX:
 275                 command_idby = CIB_PHY;
 276                 devidx = strtoul(*argv + 4, &tmp, 0);
 277                 if (*tmp != '\0')
 278                         return 1;
 279                 argc--;
 280                 argv++;
 281                 break;
 282         case II_PHY_NAME:
 283                 command_idby = CIB_PHY;
 284                 devidx = phy_lookup(*argv);
 285                 argc--;
 286                 argv++;
 287                 break;
 288         case II_NETDEV:
 289                 command_idby = CIB_NETDEV;
 290                 devidx = if_nametoindex(*argv);
 291                 if (devidx == 0)
 292                         devidx = -1;
 293                 argc--;
 294                 argv++;
 295                 break;
 296         case II_WDEV:
 297                 command_idby = CIB_WDEV;
 298                 devidx = strtoll(*argv, &tmp, 0);
 299                 if (*tmp != '\0')
 300                         return 1;
 301                 argc--;
 302                 argv++;
 303         default:
 304                 break;
 305         }
 306
 307         if (devidx < 0)
 308                 return -errno;
 309
 310         section = *argv;
 311         argc--;
 312         argv++;
 313
 314         for_each_cmd(sectcmd) {
 315                 if (sectcmd->parent)
 316                         continue;
 317                 /* ok ... bit of a hack for the dupe 'info' section */
 318                 if (match && sectcmd->idby != command_idby)
 319                         continue;
 320                 if (strcmp(sectcmd->name, section) == 0)
 321                         match = sectcmd;
 322         }
 323
 324         sectcmd = match;
 325         match = NULL;
 326         if (!sectcmd)
 327                 return 1;
 328
 329         if (argc > 0) {
 330                 command = *argv;
 331
 332                 for_each_cmd(cmd) {
 333                         if (!cmd->handler)
 334                                 continue;
 335                         if (cmd->parent != sectcmd)
 336                                 continue;
 337                         if (cmd->idby != command_idby)
 338                                 continue;
 339                         if (strcmp(cmd->name, command))
 340                                 continue;
 341                         if (argc > 1 && !cmd->args)
 342                                 continue;
 343                         match = cmd;
 344                         break;
 345                 }
 346
 347                 if (match) {
 348                         argc--;
 349                         argv++;
 350                 }
 351         }
 352
 353         if (match)
 354                 cmd = match;
 355         else {
 356                 /* Use the section itself, if possible. */
 357                 cmd = sectcmd;
 358                 if (argc && !cmd->args)
 359                         return 1;
 360                 if (cmd->idby != command_idby)
 361                         return 1;
 362                 if (!cmd->handler)
 363                         return 1;
 364         }
 365
 366         if (cmd->selector) {
 367                 cmd = cmd->selector(argc, argv);
 368                 if (!cmd)
 369                         return 1;
 370         }
 371
 372         if (cmdout)
 373                 *cmdout = cmd;
 374
 375         if (!cmd->cmd) {
 376                 argc = o_argc;
 377                 argv = o_argv;
 378                 return cmd->handler(state, NULL, NULL, argc, argv);
 379         }
 380
 381         msg = nlmsg_alloc();
 382         if (!msg) {
 383                 fprintf(stderr, "failed to allocate netlink message\n");
 384                 return 2;
 385         }
 386
 387         cb = nl_cb_alloc(iw_debug ? NL_CB_DEBUG : NL_CB_DEFAULT);
 388         s_cb = nl_cb_alloc(iw_debug ? NL_CB_DEBUG : NL_CB_DEFAULT);
 389         if (!cb || !s_cb) {
 390                 fprintf(stderr, "failed to allocate netlink callbacks\n");
 391                 err = 2;
 392                 goto out_free_msg;
 393         }
 394
 395         genlmsg_put(msg, 0, 0, state->nl80211_id, 0,
 396                     cmd->nl_msg_flags, cmd->cmd, 0);
 397
 398         switch (command_idby) {
 399         case CIB_PHY:
 400                 NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, devidx);
 401                 break;
 402         case CIB_NETDEV:
 403                 NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, devidx);
 404                 break;
 405         case CIB_WDEV:
 406                 NLA_PUT_U64(msg, NL80211_ATTR_WDEV, devidx);
 407                 break;
 408         default:
 409                 break;
 410         }
 411
 412         err = cmd->handler(state, cb, msg, argc, argv);
 413         if (err)
 414                 goto out;
 415
 416         nl_socket_set_cb(state->nl_sock, s_cb);
 417
 418         err = nl_send_auto_complete(state->nl_sock, msg);
 419         if (err < 0)
 420                 goto out;
 421
 422         err = 1;
 423
 424         nl_cb_err(cb, NL_CB_CUSTOM, error_handler, &err);
 425         nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, finish_handler, &err);
 426         nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_handler, &err);
 427
 428         while (err > 0)
 429                 nl_recvmsgs(state->nl_sock, cb);
 430  out:
 431         nl_cb_put(cb);
 432  out_free_msg:
 433         nlmsg_free(msg);
 434         return err;
 435  nla_put_failure:
 436         fprintf(stderr, "building message failed\n");
 437         return 2;
 438 }
 439
 440 int handle_cmd(struct nl80211_state *state, enum id_input idby,
 441                int argc, char **argv)
 442 {
 443         return __handle_cmd(state, idby, argc, argv, NULL);
 444 }
 445
 446 int main(int argc, char **argv)
 447 {
 448         struct nl80211_state nlstate;
 449         int err;
 450         const struct cmd *cmd = NULL;
 451
 452         /* calculate command size including padding */
 453         cmd_size = abs((long)&__section_set - (long)&__section_get);
 454         /* strip off self */
 455         argc--;
 456         argv0 = *argv++;
 457
 458         if (argc > 0 && strcmp(*argv, "--debug") == 0) {
 459                 iw_debug = 1;
 460                 argc--;
 461                 argv++;
 462         }
 463
 464         if (argc > 0 && strcmp(*argv, "--version") == 0) {
 465                 version();
 466                 return 0;
 467         }
 468
 469         /* need to treat "help" command specially so it works w/o nl80211 */
 470         if (argc == 0 || strcmp(*argv, "help") == 0) {
 471                 usage(argc - 1, argv + 1);
 472                 return 0;
 473         }
 474
 475         err = nl80211_init(&nlstate);
 476         if (err)
 477                 return 1;
 478
 479         if (strcmp(*argv, "dev") == 0 && argc > 1) {
 480                 argc--;
 481                 argv++;
 482                 err = __handle_cmd(&nlstate, II_NETDEV, argc, argv, &cmd);
 483         } else if (strncmp(*argv, "phy", 3) == 0 && argc > 1) {
 484                 if (strlen(*argv) == 3) {
 485                         argc--;
 486                         argv++;
 487                         err = __handle_cmd(&nlstate, II_PHY_NAME, argc, argv, &cmd);
 488                 } else if (*(*argv + 3) == '#')
 489                         err = __handle_cmd(&nlstate, II_PHY_IDX, argc, argv, &cmd);
 490                 else
 491                         goto detect;
 492         } else if (strcmp(*argv, "wdev") == 0 && argc > 1) {
 493                 argc--;
 494                 argv++;
 495                 err = __handle_cmd(&nlstate, II_WDEV, argc, argv, &cmd);
 496         } else {
 497                 int idx;
 498                 enum id_input idby = II_NONE;
 499  detect:
 500                 if ((idx = if_nametoindex(argv[0])) != 0)
 501                         idby = II_NETDEV;
 502                 else if ((idx = phy_lookup(argv[0])) >= 0)
 503                         idby = II_PHY_NAME;
 504                 err = __handle_cmd(&nlstate, idby, argc, argv, &cmd);
 505         }
 506
 507         if (err == 1) {
 508                 if (cmd)
 509                         usage_cmd(cmd);
 510                 else
 511                         usage(0, NULL);
 512         } else if (err < 0)
 513                 fprintf(stderr, "command failed: %s (%d)\n", strerror(-err), err);
 514
 515         nl80211_cleanup(&nlstate);
 516
 517         return err;
 518 }