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 #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 int iw_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, NULL);
  98 __COMMAND(NULL, NULL, "", NULL, 1, 0, 0, CIB_NONE, NULL, NULL);
  99
 100 static int cmd_size;
 101
 102 static void __usage_cmd(struct cmd *cmd, char *indent, bool full)
 103 {
 104         const char *start, *lend, *end;
 105
 106         printf("%s", indent);
 107
 108         switch (cmd->idby) {
 109         case CIB_NONE:
 110                 break;
 111         case CIB_PHY:
 112                 printf("phy <phyname> ");
 113                 break;
 114         case CIB_NETDEV:
 115                 printf("dev <devname> ");
 116                 break;
 117         }
 118         if (cmd->section)
 119                 printf("%s ", cmd->section);
 120         printf("%s", cmd->name);
 121         if (cmd->args)
 122                 printf(" %s", cmd->args);
 123         printf("\n");
 124
 125         if (!full || !cmd->help)
 126                 return;
 127
 128         /* hack */
 129         if (strlen(indent))
 130                 indent = "\t\t";
 131         else
 132                 printf("\n");
 133
 134         /* print line by line */
 135         start = cmd->help;
 136         end = strchr(start, '\0');
 137         do {
 138                 lend = strchr(start, '\n');
 139                 if (!lend)
 140                         lend = end;
 141                 printf("%s", indent);
 142                 printf("%.*s\n", (int)(lend - start), start);
 143                 start = lend + 1;
 144         } while (end != lend);
 145
 146         printf("\n");
 147 }
 148
 149 static void usage_options(void)
 150 {
 151         printf("Options:\n");
 152         printf("\t--debug\t\tenable netlink debugging\n");
 153 }
 154
 155 static const char *argv0;
 156
 157 static void usage(bool full)
 158 {
 159         struct cmd *cmd;
 160
 161         printf("Usage:\t%s [options] command\n", argv0);
 162         usage_options();
 163         printf("\t--version\tshow version (%s)\n", iw_version);
 164         printf("Commands:\n");
 165         for (cmd = &__start___cmd; cmd < &__stop___cmd;
 166              cmd = (struct cmd *)((char *)cmd + cmd_size)) {
 167                 if (!cmd->handler || cmd->hidden)
 168                         continue;
 169                 __usage_cmd(cmd, "\t", full);
 170         }
 171         printf("\nYou can omit the 'phy' or 'dev' if "
 172                         "the identification is unique,\n"
 173                         "e.g. \"iw wlan0 info\" or \"iw phy0 info\". "
 174                         "(Don't when scripting.)\n\n"
 175                         "Do NOT screenscrape this tool, we don't "
 176                         "consider its output stable.\n\n");
 177 }
 178
 179 static int print_help(struct nl80211_state *state,
 180                       struct nl_cb *cb,
 181                       struct nl_msg *msg,
 182                       int argc, char **argv)
 183 {
 184         exit(3);
 185 }
 186 TOPLEVEL(help, NULL, 0, 0, CIB_NONE, print_help,
 187          "Print usage for each command.");
 188
 189 static void usage_cmd(struct cmd *cmd)
 190 {
 191         printf("Usage:\t%s [options] ", argv0);
 192         __usage_cmd(cmd, "", true);
 193         usage_options();
 194 }
 195
 196 static void version(void)
 197 {
 198         printf("iw version %s\n", iw_version);
 199 }
 200
 201 static int phy_lookup(char *name)
 202 {
 203         char buf[200];
 204         int fd, pos;
 205
 206         snprintf(buf, sizeof(buf), "/sys/class/ieee80211/%s/index", name);
 207
 208         fd = open(buf, O_RDONLY);
 209         if (fd < 0)
 210                 return -1;
 211         pos = read(fd, buf, sizeof(buf) - 1);
 212         if (pos < 0)
 213                 return -1;
 214         buf[pos] = '\0';
 215         return atoi(buf);
 216 }
 217
 218 static int error_handler(struct sockaddr_nl *nla, struct nlmsgerr *err,
 219                          void *arg)
 220 {
 221         int *ret = arg;
 222         *ret = err->error;
 223         return NL_STOP;
 224 }
 225
 226 static int finish_handler(struct nl_msg *msg, void *arg)
 227 {
 228         int *ret = arg;
 229         *ret = 0;
 230         return NL_SKIP;
 231 }
 232
 233 static int ack_handler(struct nl_msg *msg, void *arg)
 234 {
 235         int *ret = arg;
 236         *ret = 0;
 237         return NL_STOP;
 238 }
 239
 240 static int __handle_cmd(struct nl80211_state *state, enum id_input idby,
 241                         int argc, char **argv, struct cmd **cmdout)
 242 {
 243         struct cmd *cmd, *match = NULL;
 244         struct nl_cb *cb;
 245         struct nl_msg *msg;
 246         int devidx = 0;
 247         int err, o_argc;
 248         const char *command, *section;
 249         char *tmp, **o_argv;
 250         enum command_identify_by command_idby = CIB_NONE;
 251
 252         if (argc <= 1 && idby != II_NONE)
 253                 return 1;
 254
 255         o_argc = argc;
 256         o_argv = argv;
 257
 258         switch (idby) {
 259         case II_PHY_IDX:
 260                 command_idby = CIB_PHY;
 261                 devidx = strtoul(*argv + 4, &tmp, 0);
 262                 if (*tmp != '\0')
 263                         return 1;
 264                 argc--;
 265                 argv++;
 266                 break;
 267         case II_PHY_NAME:
 268                 command_idby = CIB_PHY;
 269                 devidx = phy_lookup(*argv);
 270                 argc--;
 271                 argv++;
 272                 break;
 273         case II_NETDEV:
 274                 command_idby = CIB_NETDEV;
 275                 devidx = if_nametoindex(*argv);
 276                 if (devidx == 0)
 277                         devidx = -1;
 278                 argc--;
 279                 argv++;
 280                 break;
 281         default:
 282                 break;
 283         }
 284
 285         if (devidx < 0)
 286                 return -errno;
 287
 288         section = command = *argv;
 289         argc--;
 290         argv++;
 291
 292         for (cmd = &__start___cmd; cmd < &__stop___cmd;
 293              cmd = (struct cmd *)((char *)cmd + cmd_size)) {
 294                 if (!cmd->handler)
 295                         continue;
 296                 if (cmd->idby != command_idby)
 297                         continue;
 298                 if (cmd->section) {
 299                         if (strcmp(cmd->section, section))
 300                                 continue;
 301                         /* this is a bit icky ... */
 302                         if (command == section) {
 303                                 if (argc <= 0) {
 304                                         if (match)
 305                                                 break;
 306                                         return 1;
 307                                 }
 308                                 command = *argv;
 309                                 argc--;
 310                                 argv++;
 311                         }
 312                 } else if (section != command)
 313                         continue;
 314                 if (strcmp(cmd->name, command))
 315                         continue;
 316                 if (argc && !cmd->args)
 317                         continue;
 318
 319                 match = cmd;
 320         }
 321
 322         cmd = match;
 323
 324         if (!cmd)
 325                 return 1;
 326
 327         if (cmdout)
 328                 *cmdout = cmd;
 329
 330         if (!cmd->cmd) {
 331                 argc = o_argc;
 332                 argv = o_argv;
 333                 return cmd->handler(state, NULL, NULL, argc, argv);
 334         }
 335
 336         msg = nlmsg_alloc();
 337         if (!msg) {
 338                 fprintf(stderr, "failed to allocate netlink message\n");
 339                 return 2;
 340         }
 341
 342         cb = nl_cb_alloc(iw_debug ? NL_CB_DEBUG : NL_CB_DEFAULT);
 343         if (!cb) {
 344                 fprintf(stderr, "failed to allocate netlink callbacks\n");
 345                 err = 2;
 346                 goto out_free_msg;
 347         }
 348
 349         genlmsg_put(msg, 0, 0, genl_family_get_id(state->nl80211), 0,
 350                     cmd->nl_msg_flags, cmd->cmd, 0);
 351
 352         switch (command_idby) {
 353         case CIB_PHY:
 354                 NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, devidx);
 355                 break;
 356         case CIB_NETDEV:
 357                 NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, devidx);
 358                 break;
 359         default:
 360                 break;
 361         }
 362
 363         err = cmd->handler(state, cb, msg, argc, argv);
 364         if (err)
 365                 goto out;
 366
 367         err = nl_send_auto_complete(state->nl_sock, msg);
 368         if (err < 0)
 369                 goto out;
 370
 371         err = 1;
 372
 373         nl_cb_err(cb, NL_CB_CUSTOM, error_handler, &err);
 374         nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, finish_handler, &err);
 375         nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_handler, &err);
 376
 377         while (err > 0)
 378                 nl_recvmsgs(state->nl_sock, cb);
 379  out:
 380         nl_cb_put(cb);
 381  out_free_msg:
 382         nlmsg_free(msg);
 383         return err;
 384  nla_put_failure:
 385         fprintf(stderr, "building message failed\n");
 386         return 2;
 387 }
 388
 389 int handle_cmd(struct nl80211_state *state, enum id_input idby,
 390                int argc, char **argv)
 391 {
 392         return __handle_cmd(state, idby, argc, argv, NULL);
 393 }
 394
 395 int main(int argc, char **argv)
 396 {
 397         struct nl80211_state nlstate;
 398         int err;
 399         struct cmd *cmd = NULL;
 400
 401         /* calculate command size including padding */
 402         cmd_size = abs((long)&__cmd_NULL_NULL_1_CIB_NONE_0
 403                      - (long)&__cmd_NULL_NULL_0_CIB_NONE_0);
 404         /* strip off self */
 405         argc--;
 406         argv0 = *argv++;
 407
 408         if (argc > 0 && strcmp(*argv, "--debug") == 0) {
 409                 iw_debug = 1;
 410                 argc--;
 411                 argv++;
 412         }
 413
 414         if (argc > 0 && strcmp(*argv, "--version") == 0) {
 415                 version();
 416                 return 0;
 417         }
 418
 419         /* need to treat "help" command specially so it works w/o nl80211 */
 420         if (argc == 0 || strcmp(*argv, "help") == 0) {
 421                 usage(argc != 0);
 422                 return 0;
 423         }
 424
 425         err = nl80211_init(&nlstate);
 426         if (err)
 427                 return 1;
 428
 429         if (strcmp(*argv, "dev") == 0 && argc > 1) {
 430                 argc--;
 431                 argv++;
 432                 err = __handle_cmd(&nlstate, II_NETDEV, argc, argv, &cmd);
 433         } else if (strncmp(*argv, "phy", 3) == 0 && argc > 1) {
 434                 if (strlen(*argv) == 3) {
 435                         argc--;
 436                         argv++;
 437                         err = __handle_cmd(&nlstate, II_PHY_NAME, argc, argv, &cmd);
 438                 } else if (*(*argv + 3) == '#')
 439                         err = __handle_cmd(&nlstate, II_PHY_IDX, argc, argv, &cmd);
 440                 else
 441                         goto detect;
 442         } else {
 443                 int idx;
 444                 enum id_input idby = II_NONE;
 445  detect:
 446                 if ((idx = if_nametoindex(argv[0])) != 0)
 447                         idby = II_NETDEV;
 448                 else if ((idx = phy_lookup(argv[0])) >= 0)
 449                         idby = II_PHY_NAME;
 450                 err = __handle_cmd(&nlstate, idby, argc, argv, &cmd);
 451         }
 452
 453         if (err == 1) {
 454                 if (cmd)
 455                         usage_cmd(cmd);
 456                 else
 457                         usage(false);
 458         } else if (err < 0)
 459                 fprintf(stderr, "command failed: %s (%d)\n", strerror(-err), err);
 460
 461         nl80211_cleanup(&nlstate);
 462
 463         return err;
 464 }