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 enum id_input {
 182         II_NONE,
 183         II_NETDEV,
 184         II_PHY_NAME,
 185         II_PHY_IDX,
 186 };
 187
 188 static int handle_cmd(struct nl80211_state *state,
 189                       enum id_input idby,
 190                       int argc, char **argv)
 191 {
 192         struct cmd *cmd;
 193         struct nl_cb *cb = NULL;
 194         struct nl_msg *msg;
 195         int devidx = 0;
 196         int err;
 197         const char *command, *section;
 198         char *tmp;
 199         enum command_identify_by command_idby = CIB_NONE;
 200
 201         if (argc <= 1 && idby != II_NONE)
 202                 return 1;
 203
 204         switch (idby) {
 205         case II_PHY_IDX:
 206                 command_idby = CIB_PHY;
 207                 devidx = strtoul(*argv + 4, &tmp, 0);
 208                 if (*tmp != '\0')
 209                         return 1;
 210                 argc--;
 211                 argv++;
 212                 break;
 213         case II_PHY_NAME:
 214                 command_idby = CIB_PHY;
 215                 devidx = phy_lookup(*argv);
 216                 argc--;
 217                 argv++;
 218                 break;
 219         case II_NETDEV:
 220                 command_idby = CIB_NETDEV;
 221                 devidx = if_nametoindex(*argv);
 222                 if (devidx == 0)
 223                         devidx = -1;
 224                 argc--;
 225                 argv++;
 226                 break;
 227         default:
 228                 break;
 229         }
 230
 231         if (devidx < 0)
 232                 return -errno;
 233
 234         section = command = *argv;
 235         argc--;
 236         argv++;
 237
 238         for (cmd = &__start___cmd; cmd < &__stop___cmd;
 239              cmd = (struct cmd *)((char *)cmd + cmd_size)) {
 240                 if (!cmd->handler)
 241                         continue;
 242                 if (cmd->idby != command_idby)
 243                         continue;
 244                 if (cmd->section) {
 245                         if (strcmp(cmd->section, section))
 246                                 continue;
 247                         /* this is a bit icky ... */
 248                         if (command == section) {
 249                                 if (argc <= 0)
 250                                         return 1;
 251                                 command = *argv;
 252                                 argc--;
 253                                 argv++;
 254                         }
 255                 } else if (section != command)
 256                         continue;
 257                 if (strcmp(cmd->name, command))
 258                         continue;
 259                 if (argc && !cmd->args)
 260                         continue;
 261                 break;
 262         }
 263
 264         if (cmd >= &__stop___cmd)
 265                 return 1;
 266
 267         msg = nlmsg_alloc();
 268         if (!msg) {
 269                 fprintf(stderr, "failed to allocate netlink message\n");
 270                 return 2;
 271         }
 272
 273         cb = nl_cb_alloc(debug ? NL_CB_DEBUG : NL_CB_DEFAULT);
 274         if (!cb) {
 275                 fprintf(stderr, "failed to allocate netlink callbacks\n");
 276                 err = 2;
 277                 goto out_free_msg;
 278         }
 279
 280         genlmsg_put(msg, 0, 0, genl_family_get_id(state->nl80211), 0,
 281                     cmd->nl_msg_flags, cmd->cmd, 0);
 282
 283         switch (command_idby) {
 284         case CIB_PHY:
 285                 NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, devidx);
 286                 break;
 287         case CIB_NETDEV:
 288                 NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, devidx);
 289                 break;
 290         default:
 291                 break;
 292         }
 293
 294         err = cmd->handler(cb, msg, argc, argv);
 295         if (err)
 296                 goto out;
 297
 298         err = nl_send_auto_complete(state->nl_sock, msg);
 299         if (err < 0)
 300                 goto out;
 301
 302         err = 1;
 303
 304         nl_cb_err(cb, NL_CB_CUSTOM, error_handler, &err);
 305         nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, finish_handler, &err);
 306         nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_handler, &err);
 307
 308         while (err > 0)
 309                 nl_recvmsgs(state->nl_sock, cb);
 310  out:
 311         nl_cb_put(cb);
 312  out_free_msg:
 313         nlmsg_free(msg);
 314         return err;
 315  nla_put_failure:
 316         fprintf(stderr, "building message failed\n");
 317         return 2;
 318 }
 319
 320 static int no_seq_check(struct nl_msg *msg, void *arg)
 321 {
 322         return NL_OK;
 323 }
 324
 325 static int print_event(struct nl_msg *msg, void *arg)
 326 {
 327         struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
 328         struct nlattr *tb[NL80211_ATTR_MAX + 1];
 329         char ifname[100];
 330         __u8 reg_type;
 331
 332         nla_parse(tb, NL80211_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
 333                   genlmsg_attrlen(gnlh, 0), NULL);
 334
 335         switch (gnlh->cmd) {
 336         case NL80211_CMD_NEW_WIPHY:
 337                 printf("wiphy rename: phy #%d to %s\n",
 338                        nla_get_u32(tb[NL80211_ATTR_WIPHY]),
 339                        nla_get_string(tb[NL80211_ATTR_WIPHY_NAME]));
 340                 break;
 341         case NL80211_CMD_NEW_SCAN_RESULTS:
 342                 if_indextoname(nla_get_u32(tb[NL80211_ATTR_IFINDEX]), ifname);
 343                 printf("scan finished on %s (phy #%d)\n",
 344                        ifname, nla_get_u32(tb[NL80211_ATTR_WIPHY]));
 345                 break;
 346         case NL80211_CMD_SCAN_ABORTED:
 347                 if_indextoname(nla_get_u32(tb[NL80211_ATTR_IFINDEX]), ifname);
 348                 printf("scan aborted on %s (phy #%d)\n",
 349                        ifname, nla_get_u32(tb[NL80211_ATTR_WIPHY]));
 350                 break;
 351         case NL80211_CMD_REG_CHANGE:
 352
 353                 printf("regulatory domain change: ");
 354
 355                 reg_type = nla_get_u8(tb[NL80211_ATTR_REG_TYPE]);
 356
 357                 switch (reg_type) {
 358                 case NL80211_REGDOM_TYPE_COUNTRY:
 359                         printf("set to %s by %s request",
 360                                nla_get_string(tb[NL80211_ATTR_REG_ALPHA2]),
 361                                reg_initiator_to_string(nla_get_u8(tb[NL80211_ATTR_REG_INITIATOR])));
 362                         if (tb[NL80211_ATTR_WIPHY])
 363                                 printf(" on phy%d", nla_get_u32(tb[NL80211_ATTR_WIPHY]));
 364                         break;
 365                 case NL80211_REGDOM_TYPE_WORLD:
 366                         printf("set to world roaming by %s request",
 367                                reg_initiator_to_string(nla_get_u8(tb[NL80211_ATTR_REG_INITIATOR])));
 368                         break;
 369                 case NL80211_REGDOM_TYPE_CUSTOM_WORLD:
 370                         printf("custom world roaming rules in place on phy%d by %s request",
 371                                nla_get_u32(tb[NL80211_ATTR_WIPHY]),
 372                                reg_initiator_to_string(nla_get_u32(tb[NL80211_ATTR_REG_INITIATOR])));
 373                         break;
 374                 case NL80211_REGDOM_TYPE_INTERSECTION:
 375                         printf("intersection used due to a request made by %s",
 376                                reg_initiator_to_string(nla_get_u32(tb[NL80211_ATTR_REG_INITIATOR])));
 377                         if (tb[NL80211_ATTR_WIPHY])
 378                                 printf(" on phy%d", nla_get_u32(tb[NL80211_ATTR_WIPHY]));
 379                         break;
 380                 default:
 381                         printf("unknown source (upgrade this utility)");
 382                         break;
 383                 }
 384
 385                 printf("\n");
 386                 break;
 387         default:
 388                 printf("unknown event: %d\n", gnlh->cmd);
 389                 break;
 390         }
 391
 392         return NL_SKIP;
 393 }
 394
 395 static int listen_events(struct nl80211_state *state,
 396                          int argc, char **argv)
 397 {
 398         int mcid, ret;
 399         struct nl_cb *cb = nl_cb_alloc(debug ? NL_CB_DEBUG : NL_CB_DEFAULT);
 400
 401         if (!cb) {
 402                 fprintf(stderr, "failed to allocate netlink callbacks\n");
 403                 return -ENOMEM;
 404         }
 405
 406         /* Configuration multicast group */
 407         mcid = nl_get_multicast_id(state->nl_sock, "nl80211", "config");
 408         if (mcid < 0)
 409                 return mcid;
 410
 411         ret = nl_socket_add_membership(state->nl_sock, mcid);
 412         if (ret)
 413                 return ret;
 414
 415         /* Scan multicast group */
 416         mcid = nl_get_multicast_id(state->nl_sock, "nl80211", "scan");
 417         if (mcid >= 0) {
 418                 ret = nl_socket_add_membership(state->nl_sock, mcid);
 419                 if (ret)
 420                         return ret;
 421         }
 422
 423         /* Regulatory multicast group */
 424         mcid = nl_get_multicast_id(state->nl_sock, "nl80211", "regulatory");
 425         if (mcid >= 0) {
 426                 ret = nl_socket_add_membership(state->nl_sock, mcid);
 427                 if (ret)
 428                         return ret;
 429         }
 430
 431         /* no sequence checking for multicast messages */
 432         nl_cb_set(cb, NL_CB_SEQ_CHECK, NL_CB_CUSTOM, no_seq_check, NULL);
 433         nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, print_event, NULL);
 434
 435         while (1)
 436                 nl_recvmsgs(state->nl_sock, cb);
 437
 438         nl_cb_put(cb);
 439
 440         return 0;
 441 }
 442
 443 int main(int argc, char **argv)
 444 {
 445         struct nl80211_state nlstate;
 446         int err;
 447         const char *argv0;
 448
 449         /* calculate command size including padding */
 450         cmd_size = abs((long)&__cmd_NULL_1_CIB_NONE_0
 451                      - (long)&__cmd_NULL_0_CIB_NONE_0);
 452         /* strip off self */
 453         argc--;
 454         argv0 = *argv++;
 455
 456         if (argc > 0 && strcmp(*argv, "--debug") == 0) {
 457                 debug = 1;
 458                 argc--;
 459                 argv++;
 460         }
 461
 462         if (argc > 0 && strcmp(*argv, "--version") == 0) {
 463                 version();
 464                 return 0;
 465         }
 466
 467         if (argc == 0 || strcmp(*argv, "help") == 0) {
 468                 usage(argv0);
 469                 return 0;
 470         }
 471
 472         err = nl80211_init(&nlstate);
 473         if (err)
 474                 return 1;
 475
 476         if (strcmp(*argv, "event") == 0) {
 477                 err = listen_events(&nlstate, argc, argv);
 478         } else if (strcmp(*argv, "dev") == 0) {
 479                 argc--;
 480                 argv++;
 481                 err = handle_cmd(&nlstate, II_NETDEV, argc, argv);
 482         } else if (strncmp(*argv, "phy", 3) == 0) {
 483                 if (strlen(*argv) == 3) {
 484                         argc--;
 485                         argv++;
 486                         err = handle_cmd(&nlstate, II_PHY_NAME, argc, argv);
 487                 } else if (*(*argv + 3) == '#')
 488                         err = handle_cmd(&nlstate, II_PHY_IDX, argc, argv);
 489                 else
 490                         err = 1;
 491         } else
 492                 err = handle_cmd(&nlstate, II_NONE, argc, argv);
 493
 494         if (err == 1)
 495                 usage(argv0);
 496         if (err < 0)
 497                 fprintf(stderr, "command failed: %s (%d)\n", strerror(-err), err);
 498
 499         nl80211_cleanup(&nlstate);
 500
 501         return err;
 502 }