iwinfo_utils.c

   1 /*
   2  * iwinfo - Wireless Information Library - Shared utility routines
   3  *
   4  *   Copyright (C) 2010 Jo-Philipp Wich <xm@subsignal.org>
   5  *
   6  * The iwinfo library is free software: you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License version 2
   8  * as published by the Free Software Foundation.
   9  *
  10  * The iwinfo library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  13  * See the GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with the iwinfo library. If not, see http://www.gnu.org/licenses/.
  17  *
  18  * The signal handling code is derived from the official madwifi tools,
  19  * wlanconfig.c in particular. The encryption property handling was
  20  * inspired by the hostapd madwifi driver.
  21  */
  22
  23 #include "iwinfo/utils.h"
  24
  25
  26 static int ioctl_socket = -1;
  27 struct uci_context *uci_ctx = NULL;
  28
  29 static int iwinfo_ioctl_socket(void)
  30 {
  31         /* Prepare socket */
  32         if (ioctl_socket == -1)
  33         {
  34                 ioctl_socket = socket(AF_INET, SOCK_DGRAM, 0);
  35                 fcntl(ioctl_socket, F_SETFD, fcntl(ioctl_socket, F_GETFD) | FD_CLOEXEC);
  36         }
  37
  38         return ioctl_socket;
  39 }
  40
  41 int iwinfo_ioctl(int cmd, void *ifr)
  42 {
  43         int s = iwinfo_ioctl_socket();
  44         return ioctl(s, cmd, ifr);
  45 }
  46
  47 int iwinfo_dbm2mw(int in)
  48 {
  49         double res = 1.0;
  50         int ip = in / 10;
  51         int fp = in % 10;
  52         int k;
  53
  54         for(k = 0; k < ip; k++) res *= 10;
  55         for(k = 0; k < fp; k++) res *= LOG10_MAGIC;
  56
  57         return (int)res;
  58 }
  59
  60 int iwinfo_mw2dbm(int in)
  61 {
  62         double fin = (double) in;
  63         int res = 0;
  64
  65         while(fin > 10.0)
  66         {
  67                 res += 10;
  68                 fin /= 10.0;
  69         }
  70
  71         while(fin > 1.000001)
  72         {
  73                 res += 1;
  74                 fin /= LOG10_MAGIC;
  75         }
  76
  77         return (int)res;
  78 }
  79
  80 static int iwinfo_bit(int value, int max)
  81 {
  82         int i;
  83
  84         if (max > 31 || !(value & ((1 << max) - 1)))
  85                 return -1;
  86
  87         for (i = 0; i < max; i++)
  88         {
  89                 if (value & 1)
  90                         break;
  91
  92                 value >>= 1;
  93         }
  94
  95         return i;
  96 }
  97
  98 static const char * const iwinfo_name(int mask, int max, const char * const names[])
  99 {
 100         int index = iwinfo_bit(mask, max);
 101
 102         if (index < 0)
 103                 return NULL;
 104
 105         return names[index];
 106 }
 107
 108 const char * const iwinfo_band_name(int mask)
 109 {
 110         return iwinfo_name(mask, IWINFO_BAND_COUNT, IWINFO_BAND_NAMES);
 111 }
 112
 113 const char * const iwinfo_htmode_name(int mask)
 114 {
 115         return iwinfo_name(mask, IWINFO_HTMODE_COUNT, IWINFO_HTMODE_NAMES);
 116 }
 117
 118 uint32_t iwinfo_band2ghz(uint8_t band)
 119 {
 120         switch (band)
 121         {
 122         case IWINFO_BAND_24:
 123                 return 2;
 124         case IWINFO_BAND_5:
 125                 return 5;
 126         case IWINFO_BAND_6:
 127                 return 6;
 128         case IWINFO_BAND_60:
 129                 return 60;
 130         }
 131
 132         return 0;
 133 }
 134
 135 uint8_t iwinfo_ghz2band(uint32_t ghz)
 136 {
 137         switch (ghz)
 138         {
 139         case 2:
 140                 return IWINFO_BAND_24;
 141         case 5:
 142                 return IWINFO_BAND_5;
 143         case 6:
 144                 return IWINFO_BAND_6;
 145         case 60:
 146                 return IWINFO_BAND_60;
 147         }
 148
 149         return 0;
 150 }
 151
 152 size_t iwinfo_format_hwmodes(int modes, char *buf, size_t len)
 153 {
 154         // bit numbers as per IWINFO_80211_*:  ad ac ax  a  b  g  n
 155         const int order[IWINFO_80211_COUNT] = { 5, 4, 6, 0, 1, 2, 3 };
 156         size_t res = 0;
 157         int i;
 158
 159         *buf = 0;
 160
 161         if (!(modes & ((1 << IWINFO_80211_COUNT) - 1)))
 162                 return 0;
 163
 164         for (i = 0; i < IWINFO_80211_COUNT; i++)
 165                 if (modes & 1 << order[i])
 166                         res += snprintf(buf + res, len - res, "%s/", IWINFO_80211_NAMES[order[i]]);
 167
 168         if (res > 0)
 169         {
 170                 res--;
 171                 buf[res] = 0;
 172         }
 173
 174         return res;
 175 }
 176
 177 int iwinfo_htmode_is_ht(int htmode)
 178 {
 179         switch (htmode)
 180         {
 181         case IWINFO_HTMODE_HT20:
 182         case IWINFO_HTMODE_HT40:
 183                 return 1;
 184         }
 185
 186         return 0;
 187 }
 188
 189 int iwinfo_htmode_is_vht(int htmode)
 190 {
 191         switch (htmode)
 192         {
 193         case IWINFO_HTMODE_VHT20:
 194         case IWINFO_HTMODE_VHT40:
 195         case IWINFO_HTMODE_VHT80:
 196         case IWINFO_HTMODE_VHT80_80:
 197         case IWINFO_HTMODE_VHT160:
 198                 return 1;
 199         }
 200
 201         return 0;
 202 }
 203
 204 int iwinfo_htmode_is_he(int htmode)
 205 {
 206         switch (htmode)
 207         {
 208         case IWINFO_HTMODE_HE20:
 209         case IWINFO_HTMODE_HE40:
 210         case IWINFO_HTMODE_HE80:
 211         case IWINFO_HTMODE_HE80_80:
 212         case IWINFO_HTMODE_HE160:
 213                 return 1;
 214         }
 215
 216         return 0;
 217 }
 218
 219 int iwinfo_ifup(const char *ifname)
 220 {
 221         struct ifreq ifr;
 222
 223         strncpy(ifr.ifr_name, ifname, IFNAMSIZ - 1);
 224
 225         if (iwinfo_ioctl(SIOCGIFFLAGS, &ifr))
 226                 return 0;
 227
 228         ifr.ifr_flags |= (IFF_UP | IFF_RUNNING);
 229
 230         return !iwinfo_ioctl(SIOCSIFFLAGS, &ifr);
 231 }
 232
 233 int iwinfo_ifdown(const char *ifname)
 234 {
 235         struct ifreq ifr;
 236
 237         strncpy(ifr.ifr_name, ifname, IFNAMSIZ - 1);
 238
 239         if (iwinfo_ioctl(SIOCGIFFLAGS, &ifr))
 240                 return 0;
 241
 242         ifr.ifr_flags &= ~(IFF_UP | IFF_RUNNING);
 243
 244         return !iwinfo_ioctl(SIOCSIFFLAGS, &ifr);
 245 }
 246
 247 int iwinfo_ifmac(const char *ifname)
 248 {
 249         struct ifreq ifr;
 250
 251         strncpy(ifr.ifr_name, ifname, IFNAMSIZ - 1);
 252
 253         if (iwinfo_ioctl(SIOCGIFHWADDR, &ifr))
 254                 return 0;
 255
 256         ifr.ifr_hwaddr.sa_data[0] |= 0x02;
 257         ifr.ifr_hwaddr.sa_data[1]++;
 258         ifr.ifr_hwaddr.sa_data[2]++;
 259
 260         return !iwinfo_ioctl(SIOCSIFHWADDR, &ifr);
 261 }
 262
 263 void iwinfo_close(void)
 264 {
 265         if (ioctl_socket > -1)
 266                 close(ioctl_socket);
 267
 268         ioctl_socket = -1;
 269 }
 270
 271 struct iwinfo_hardware_entry * iwinfo_hardware(struct iwinfo_hardware_id *id)
 272 {
 273         FILE *db;
 274         char buf[256] = { 0 };
 275         static struct iwinfo_hardware_entry e;
 276         struct iwinfo_hardware_entry *rv = NULL;
 277
 278         if (!(db = fopen(IWINFO_HARDWARE_FILE, "r")))
 279                 return NULL;
 280
 281         while (fgets(buf, sizeof(buf) - 1, db) != NULL)
 282         {
 283                 if (buf[0] == '#')
 284                         continue;
 285
 286                 memset(&e, 0, sizeof(e));
 287
 288                 if (sscanf(buf, "%hx %hx %hx %hx %hd %hd \"%63[^\"]\" \"%63[^\"]\"",
 289                                &e.vendor_id, &e.device_id,
 290                                &e.subsystem_vendor_id, &e.subsystem_device_id,
 291                                &e.txpower_offset, &e.frequency_offset,
 292                                e.vendor_name, e.device_name) != 8 &&
 293                         sscanf(buf, "\"%127[^\"]\" %hd %hd \"%63[^\"]\" \"%63[^\"]\"",
 294                                e.compatible, &e.txpower_offset, &e.frequency_offset,
 295                                e.vendor_name, e.device_name) != 5)
 296                         continue;
 297
 298                 if ((e.vendor_id != 0xffff) && (e.vendor_id != id->vendor_id))
 299                         continue;
 300
 301                 if ((e.device_id != 0xffff) && (e.device_id != id->device_id))
 302                         continue;
 303
 304                 if ((e.subsystem_vendor_id != 0xffff) &&
 305                         (e.subsystem_vendor_id != id->subsystem_vendor_id))
 306                         continue;
 307
 308                 if ((e.subsystem_device_id != 0xffff) &&
 309                         (e.subsystem_device_id != id->subsystem_device_id))
 310                         continue;
 311
 312                 if (strcmp(e.compatible, id->compatible))
 313                         continue;
 314
 315                 rv = &e;
 316                 break;
 317         }
 318
 319         fclose(db);
 320         return rv;
 321 }
 322
 323 int iwinfo_hardware_id_from_mtd(struct iwinfo_hardware_id *id)
 324 {
 325         FILE *mtd;
 326         uint16_t *bc;
 327
 328         int fd, off;
 329         unsigned int len;
 330         char buf[128];
 331
 332         if (!(mtd = fopen("/proc/mtd", "r")))
 333                 return -1;
 334
 335         while (fgets(buf, sizeof(buf), mtd) != NULL)
 336         {
 337                 if (fscanf(mtd, "mtd%d: %x %*x %127s", &off, &len, buf) < 3 ||
 338                     (strcmp(buf, "\"boardconfig\"") && strcmp(buf, "\"EEPROM\"") &&
 339                      strcmp(buf, "\"factory\"")))
 340                 {
 341                         off = -1;
 342                         continue;
 343                 }
 344
 345                 break;
 346         }
 347
 348         fclose(mtd);
 349
 350         if (off < 0)
 351                 return -1;
 352
 353         snprintf(buf, sizeof(buf), "/dev/mtdblock%d", off);
 354
 355         if ((fd = open(buf, O_RDONLY)) < 0)
 356                 return -1;
 357
 358         bc = mmap(NULL, len, PROT_READ, MAP_PRIVATE|MAP_LOCKED, fd, 0);
 359
 360         if ((void *)bc != MAP_FAILED)
 361         {
 362                 id->vendor_id = 0;
 363                 id->device_id = 0;
 364
 365                 for (off = len / 2 - 0x800; off >= 0; off -= 0x800)
 366                 {
 367                         /* AR531X board data magic */
 368                         if ((bc[off] == 0x3533) && (bc[off + 1] == 0x3131))
 369                         {
 370                                 id->vendor_id = bc[off + 0x7d];
 371                                 id->device_id = bc[off + 0x7c];
 372                                 id->subsystem_vendor_id = bc[off + 0x84];
 373                                 id->subsystem_device_id = bc[off + 0x83];
 374                                 break;
 375                         }
 376
 377                         /* AR5416 EEPROM magic */
 378                         else if ((bc[off] == 0xA55A) || (bc[off] == 0x5AA5))
 379                         {
 380                                 id->vendor_id = bc[off + 0x0D];
 381                                 id->device_id = bc[off + 0x0E];
 382                                 id->subsystem_vendor_id = bc[off + 0x13];
 383                                 id->subsystem_device_id = bc[off + 0x14];
 384                                 break;
 385                         }
 386
 387                         /* Rt3xxx SoC */
 388                         else if ((bc[off] == 0x3050) || (bc[off] == 0x5030) ||
 389                                  (bc[off] == 0x3051) || (bc[off] == 0x5130) ||
 390                                  (bc[off] == 0x3052) || (bc[off] == 0x5230) ||
 391                                  (bc[off] == 0x3350) || (bc[off] == 0x5033) ||
 392                                  (bc[off] == 0x3352) || (bc[off] == 0x5233) ||
 393                                  (bc[off] == 0x3662) || (bc[off] == 0x6236) ||
 394                                  (bc[off] == 0x3883) || (bc[off] == 0x8338) ||
 395                                  (bc[off] == 0x5350) || (bc[off] == 0x5053))
 396                         {
 397                                 /* vendor: RaLink */
 398                                 id->vendor_id = 0x1814;
 399                                 id->subsystem_vendor_id = 0x1814;
 400
 401                                 /* device */
 402                                 if (((bc[off] & 0xf0) == 0x30) ||
 403                                     ((bc[off] & 0xff) == 0x53))
 404                                         id->device_id = (bc[off] >> 8) | (bc[off] & 0x00ff) << 8;
 405                                 else
 406                                         id->device_id = bc[off];
 407
 408                                 /* subsystem from EEPROM_NIC_CONF0_RF_TYPE */
 409                                 id->subsystem_device_id = (bc[off + 0x1a] & 0x0f00) >> 8;
 410                         } else if ((bc[off] == 0x7620) || (bc[off] == 0x2076) ||
 411                                    (bc[off] == 0x7628) || (bc[off] == 0x2876) ||
 412                                    (bc[off] == 0x7688) || (bc[off] == 0x8876)) {
 413                                 /* vendor: MediaTek */
 414                                 id->vendor_id = 0x14c3;
 415                                 id->subsystem_vendor_id = 0x14c3;
 416
 417                                 /* device */
 418                                 if ((bc[off] & 0xff) == 0x76)
 419                                         id->device_id = (bc[off] >> 8) | (bc[off] & 0x00ff) << 8;
 420                                 else
 421                                         id->device_id = bc[off];
 422
 423                                 /* subsystem from EEPROM_NIC_CONF0_RF_TYPE */
 424                                 id->subsystem_device_id = (bc[off + 0x1a] & 0x0f00) >> 8;
 425                         }
 426                 }
 427
 428                 munmap(bc, len);
 429         }
 430
 431         close(fd);
 432
 433         return (id->vendor_id && id->device_id) ? 0 : -1;
 434 }
 435
 436 static void iwinfo_parse_rsn_cipher(uint8_t idx, uint16_t *ciphers)
 437 {
 438         switch (idx)
 439         {
 440                 case 0:
 441                         *ciphers |= IWINFO_CIPHER_NONE;
 442                         break;
 443
 444                 case 1:
 445                         *ciphers |= IWINFO_CIPHER_WEP40;
 446                         break;
 447
 448                 case 2:
 449                         *ciphers |= IWINFO_CIPHER_TKIP;
 450                         break;
 451
 452                 case 3:  /* WRAP */
 453                         break;
 454
 455                 case 4:
 456                         *ciphers |= IWINFO_CIPHER_CCMP;
 457                         break;
 458
 459                 case 5:
 460                         *ciphers |= IWINFO_CIPHER_WEP104;
 461                         break;
 462
 463                 case 8:
 464                         *ciphers |= IWINFO_CIPHER_GCMP;
 465                         break;
 466
 467                 case 9:
 468                         *ciphers |= IWINFO_CIPHER_GCMP256;
 469                         break;
 470
 471                 case 10:
 472                         *ciphers |= IWINFO_CIPHER_CCMP256;
 473                         break;
 474
 475                 case 6:  /* AES-128-CMAC */
 476                 case 7:  /* No group addressed */
 477                 case 11: /* BIP-GMAC-128 */
 478                 case 12: /* BIP-GMAC-256 */
 479                 case 13: /* BIP-CMAC-256 */
 480                         break;
 481         }
 482 }
 483
 484 void iwinfo_parse_rsn(struct iwinfo_crypto_entry *c, uint8_t *data, uint8_t len,
 485                                           uint16_t defcipher, uint8_t defauth)
 486 {
 487         uint16_t i, count;
 488         uint8_t wpa_version = 0;
 489
 490         static unsigned char ms_oui[3]        = { 0x00, 0x50, 0xf2 };
 491         static unsigned char ieee80211_oui[3] = { 0x00, 0x0f, 0xac };
 492
 493         data += 2;
 494         len -= 2;
 495
 496         if (!memcmp(data, ms_oui, 3))
 497                 wpa_version |= 1;
 498         else if (!memcmp(data, ieee80211_oui, 3))
 499                 wpa_version |= 2;
 500
 501         if (len < 4)
 502         {
 503                 c->group_ciphers |= defcipher;
 504                 c->pair_ciphers  |= defcipher;
 505                 c->auth_suites   |= defauth;
 506                 return;
 507         }
 508
 509         if (!memcmp(data, ms_oui, 3) || !memcmp(data, ieee80211_oui, 3))
 510                 iwinfo_parse_rsn_cipher(data[3], &c->group_ciphers);
 511
 512         data += 4;
 513         len -= 4;
 514
 515         if (len < 2)
 516         {
 517                 c->pair_ciphers |= defcipher;
 518                 c->auth_suites  |= defauth;
 519                 return;
 520         }
 521
 522         count = data[0] | (data[1] << 8);
 523         if (2 + (count * 4) > len)
 524                 return;
 525
 526         for (i = 0; i < count; i++)
 527                 if (!memcmp(data + 2 + (i * 4), ms_oui, 3) ||
 528                     !memcmp(data + 2 + (i * 4), ieee80211_oui, 3))
 529                         iwinfo_parse_rsn_cipher(data[2 + (i * 4) + 3], &c->pair_ciphers);
 530
 531         data += 2 + (count * 4);
 532         len -= 2 + (count * 4);
 533
 534         if (len < 2)
 535         {
 536                 c->auth_suites |= defauth;
 537                 return;
 538         }
 539
 540         count = data[0] | (data[1] << 8);
 541         if (2 + (count * 4) > len)
 542                 return;
 543
 544         for (i = 0; i < count; i++)
 545         {
 546                 if (!memcmp(data + 2 + (i * 4), ms_oui, 3) ||
 547                         !memcmp(data + 2 + (i * 4), ieee80211_oui, 3))
 548                 {
 549                         switch (data[2 + (i * 4) + 3])
 550                         {
 551                                 case 1:  /* IEEE 802.1x */
 552                                         c->wpa_version |= wpa_version;
 553                                         c->auth_suites |= IWINFO_KMGMT_8021x;
 554                                         break;
 555
 556                                 case 2:  /* PSK */
 557                                         c->wpa_version |= wpa_version;
 558                                         c->auth_suites |= IWINFO_KMGMT_PSK;
 559                                         break;
 560
 561                                 case 3:  /* FT/IEEE 802.1X */
 562                                 case 4:  /* FT/PSK */
 563                                 case 5:  /* IEEE 802.1X/SHA-256 */
 564                                 case 6:  /* PSK/SHA-256 */
 565                                 case 7:  /* TPK Handshake */
 566                                         break;
 567
 568                                 case 8:  /* SAE */
 569                                         c->wpa_version |= 4;
 570                                         c->auth_suites |= IWINFO_KMGMT_SAE;
 571                                         break;
 572
 573                                 case 9:  /* FT/SAE */
 574                                 case 10: /* undefined */
 575                                         break;
 576
 577                                 case 11: /* 802.1x Suite-B */
 578                                 case 12: /* 802.1x Suite-B-192 */
 579                                 case 13: /* FT/802.1x SHA-384 */
 580                                         c->wpa_version |= 4;
 581                                         c->auth_suites |= IWINFO_KMGMT_8021x;
 582                                         break;
 583
 584                                 case 14: /* FILS SHA-256 */
 585                                 case 15: /* FILS SHA-384 */
 586                                 case 16: /* FT/FILS SHA-256 */
 587                                 case 17: /* FT/FILS SHA-384 */
 588                                         break;
 589
 590                                 case 18: /* OWE */
 591                                         c->wpa_version |= 4;
 592                                         c->auth_suites |= IWINFO_KMGMT_OWE;
 593                                         break;
 594                         }
 595                 }
 596         }
 597
 598         data += 2 + (count * 4);
 599         len -= 2 + (count * 4);
 600 }
 601
 602 struct uci_section *iwinfo_uci_get_radio(const char *name, const char *type)
 603 {
 604         struct uci_ptr ptr = {
 605                 .package = "wireless",
 606                 .section = name,
 607                 .flags = (name && *name == '@') ? UCI_LOOKUP_EXTENDED : 0,
 608         };
 609         const char *opt;
 610
 611         if (!uci_ctx) {
 612                 uci_ctx = uci_alloc_context();
 613                 if (!uci_ctx)
 614                         return NULL;
 615         }
 616
 617         if (uci_lookup_ptr(uci_ctx, &ptr, NULL, true))
 618                 return NULL;
 619
 620         if (!ptr.s || strcmp(ptr.s->type, "wifi-device") != 0)
 621                 return NULL;
 622
 623         opt = uci_lookup_option_string(uci_ctx, ptr.s, "type");
 624         if (!opt || strcmp(opt, type) != 0)
 625                 return NULL;
 626
 627         return ptr.s;
 628 }
 629
 630 void iwinfo_uci_free(void)
 631 {
 632         if (!uci_ctx)
 633                 return;
 634
 635         uci_free_context(uci_ctx);
 636         uci_ctx = NULL;
 637 }
 638
 639
 640 struct iwinfo_ubus_query_state {
 641         const char *ifname;
 642         const char *field;
 643         size_t len;
 644         char *buf;
 645 };
 646
 647 static void iwinfo_ubus_query_cb(struct ubus_request *req, int type,
 648                                  struct blob_attr *msg)
 649 {
 650         struct iwinfo_ubus_query_state *st = req->priv;
 651
 652         struct blobmsg_policy pol1[2] = {
 653                 { "ifname",  BLOBMSG_TYPE_STRING },
 654                 { "config",  BLOBMSG_TYPE_TABLE }
 655         };
 656
 657         struct blobmsg_policy pol2 = { st->field, BLOBMSG_TYPE_STRING };
 658         struct blob_attr *cur, *cur2, *cur3, *cfg[2], *res;
 659         int rem, rem2, rem3;
 660
 661         blobmsg_for_each_attr(cur, msg, rem) {
 662                 if (blobmsg_type(cur) != BLOBMSG_TYPE_TABLE)
 663                         continue;
 664
 665                 blobmsg_for_each_attr(cur2, cur, rem2) {
 666                         if (blobmsg_type(cur2) != BLOBMSG_TYPE_ARRAY)
 667                                 continue;
 668
 669                         if (strcmp(blobmsg_name(cur2), "interfaces"))
 670                                 continue;
 671
 672                         blobmsg_for_each_attr(cur3, cur2, rem3) {
 673                                 blobmsg_parse(pol1, sizeof(pol1) / sizeof(pol1[0]), cfg,
 674                                               blobmsg_data(cur3), blobmsg_len(cur3));
 675
 676                                 if (!cfg[0] || !cfg[1] ||
 677                                     strcmp(blobmsg_get_string(cfg[0]), st->ifname))
 678                                         continue;
 679
 680                                 blobmsg_parse(&pol2, 1, &res,
 681                                               blobmsg_data(cfg[1]), blobmsg_len(cfg[1]));
 682
 683                                 if (!res)
 684                                         continue;
 685
 686                                 strncpy(st->buf, blobmsg_get_string(res), st->len);
 687                                 return;
 688                         }
 689                 }
 690         }
 691 }
 692
 693 int iwinfo_ubus_query(const char *ifname, const char *field,
 694                       char *buf, size_t len)
 695 {
 696         struct iwinfo_ubus_query_state st = {
 697                 .ifname = ifname,
 698                 .field = field,
 699                 .buf = buf,
 700                 .len = len
 701         };
 702
 703         struct ubus_context *ctx = NULL;
 704         struct blob_buf b = { };
 705         int rv = -1;
 706         uint32_t id;
 707
 708         blob_buf_init(&b, 0);
 709
 710         ctx = ubus_connect(NULL);
 711
 712         if (!ctx)
 713                 goto out;
 714
 715         if (ubus_lookup_id(ctx, "network.wireless", &id))
 716                 goto out;
 717
 718         if (ubus_invoke(ctx, id, "status", b.head, iwinfo_ubus_query_cb, &st, 250))
 719                 goto out;
 720
 721         rv = 0;
 722
 723 out:
 724         if (ctx)
 725                 ubus_free(ctx);
 726
 727         blob_buf_free(&b);
 728
 729         return rv;
 730 }