libeap/src/p2p/p2p_utils.c

   1 /*
   2  * P2P - generic helper functions
   3  * Copyright (c) 2009, Atheros Communications
   4  *
   5  * This software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "includes.h"
  10
  11 #include "common.h"
  12 #include "common/defs.h"
  13 #include "common/ieee802_11_common.h"
  14 #include "p2p_i.h"
  15
  16
  17 /**
  18  * p2p_random - Generate random string for SSID and passphrase
  19  * @buf: Buffer for returning the result
  20  * @len: Number of octets to write to the buffer
  21  * Returns: 0 on success, -1 on failure
  22  *
  23  * This function generates a random string using the following character set:
  24  * 'A'-'Z', 'a'-'z', '0'-'9'.
  25  */
  26 int p2p_random(char *buf, size_t len)
  27 {
  28         u8 val;
  29         size_t i;
  30         u8 letters = 'Z' - 'A' + 1;
  31         u8 numbers = 10;
  32
  33         if (os_get_random((unsigned char *) buf, len))
  34                 return -1;
  35         /* Character set: 'A'-'Z', 'a'-'z', '0'-'9' */
  36         for (i = 0; i < len; i++) {
  37                 val = buf[i];
  38                 val %= 2 * letters + numbers;
  39                 if (val < letters)
  40                         buf[i] = 'A' + val;
  41                 else if (val < 2 * letters)
  42                         buf[i] = 'a' + (val - letters);
  43                 else
  44                         buf[i] = '0' + (val - 2 * letters);
  45         }
  46
  47         return 0;
  48 }
  49
  50
  51 /**
  52  * p2p_channel_to_freq - Convert channel info to frequency
  53  * @op_class: Operating class
  54  * @channel: Channel number
  55  * Returns: Frequency in MHz or -1 if the specified channel is unknown
  56  */
  57 int p2p_channel_to_freq(int op_class, int channel)
  58 {
  59         return ieee80211_chan_to_freq(NULL, op_class, channel);
  60 }
  61
  62
  63 /**
  64  * p2p_freq_to_channel - Convert frequency into channel info
  65  * @op_class: Buffer for returning operating class
  66  * @channel: Buffer for returning channel number
  67  * Returns: 0 on success, -1 if the specified frequency is unknown
  68  */
  69 int p2p_freq_to_channel(unsigned int freq, u8 *op_class, u8 *channel)
  70 {
  71         if (ieee80211_freq_to_channel_ext(freq, 0, 0, op_class, channel) ==
  72             NUM_HOSTAPD_MODES)
  73                 return -1;
  74
  75         return 0;
  76 }
  77
  78
  79 static void p2p_reg_class_intersect(const struct p2p_reg_class *a,
  80                                     const struct p2p_reg_class *b,
  81                                     struct p2p_reg_class *res)
  82 {
  83         size_t i, j;
  84
  85         res->reg_class = a->reg_class;
  86
  87         for (i = 0; i < a->channels; i++) {
  88                 for (j = 0; j < b->channels; j++) {
  89                         if (a->channel[i] != b->channel[j])
  90                                 continue;
  91                         res->channel[res->channels] = a->channel[i];
  92                         res->channels++;
  93                         if (res->channels == P2P_MAX_REG_CLASS_CHANNELS)
  94                                 return;
  95                 }
  96         }
  97 }
  98
  99
 100 /**
 101  * p2p_channels_intersect - Intersection of supported channel lists
 102  * @a: First set of supported channels
 103  * @b: Second set of supported channels
 104  * @res: Data structure for returning the intersection of support channels
 105  *
 106  * This function can be used to find a common set of supported channels. Both
 107  * input channels sets are assumed to use the same country code. If different
 108  * country codes are used, the regulatory class numbers may not be matched
 109  * correctly and results are undefined.
 110  */
 111 void p2p_channels_intersect(const struct p2p_channels *a,
 112                             const struct p2p_channels *b,
 113                             struct p2p_channels *res)
 114 {
 115         size_t i, j;
 116
 117         os_memset(res, 0, sizeof(*res));
 118
 119         for (i = 0; i < a->reg_classes; i++) {
 120                 const struct p2p_reg_class *a_reg = &a->reg_class[i];
 121                 for (j = 0; j < b->reg_classes; j++) {
 122                         const struct p2p_reg_class *b_reg = &b->reg_class[j];
 123                         if (a_reg->reg_class != b_reg->reg_class)
 124                                 continue;
 125                         p2p_reg_class_intersect(
 126                                 a_reg, b_reg,
 127                                 &res->reg_class[res->reg_classes]);
 128                         if (res->reg_class[res->reg_classes].channels) {
 129                                 res->reg_classes++;
 130                                 if (res->reg_classes == P2P_MAX_REG_CLASSES)
 131                                         return;
 132                         }
 133                 }
 134         }
 135 }
 136
 137
 138 static void p2p_op_class_union(struct p2p_reg_class *cl,
 139                                const struct p2p_reg_class *b_cl)
 140 {
 141         size_t i, j;
 142
 143         for (i = 0; i < b_cl->channels; i++) {
 144                 for (j = 0; j < cl->channels; j++) {
 145                         if (b_cl->channel[i] == cl->channel[j])
 146                                 break;
 147                 }
 148                 if (j == cl->channels) {
 149                         if (cl->channels == P2P_MAX_REG_CLASS_CHANNELS)
 150                                 return;
 151                         cl->channel[cl->channels++] = b_cl->channel[i];
 152                 }
 153         }
 154 }
 155
 156
 157 /**
 158  * p2p_channels_union_inplace - Inplace union of channel lists
 159  * @res: Input data and place for returning union of the channel sets
 160  * @b: Second set of channels
 161  */
 162 void p2p_channels_union_inplace(struct p2p_channels *res,
 163                                 const struct p2p_channels *b)
 164 {
 165         size_t i, j;
 166
 167         for (i = 0; i < res->reg_classes; i++) {
 168                 struct p2p_reg_class *cl = &res->reg_class[i];
 169                 for (j = 0; j < b->reg_classes; j++) {
 170                         const struct p2p_reg_class *b_cl = &b->reg_class[j];
 171                         if (cl->reg_class != b_cl->reg_class)
 172                                 continue;
 173                         p2p_op_class_union(cl, b_cl);
 174                 }
 175         }
 176
 177         for (j = 0; j < b->reg_classes; j++) {
 178                 const struct p2p_reg_class *b_cl = &b->reg_class[j];
 179
 180                 for (i = 0; i < res->reg_classes; i++) {
 181                         struct p2p_reg_class *cl = &res->reg_class[i];
 182                         if (cl->reg_class == b_cl->reg_class)
 183                                 break;
 184                 }
 185
 186                 if (i == res->reg_classes) {
 187                         if (res->reg_classes == P2P_MAX_REG_CLASSES)
 188                                 return;
 189                         os_memcpy(&res->reg_class[res->reg_classes++],
 190                                   b_cl, sizeof(struct p2p_reg_class));
 191                 }
 192         }
 193 }
 194
 195
 196 /**
 197  * p2p_channels_union - Union of channel lists
 198  * @a: First set of channels
 199  * @b: Second set of channels
 200  * @res: Data structure for returning the union of channels
 201  */
 202 void p2p_channels_union(const struct p2p_channels *a,
 203                         const struct p2p_channels *b,
 204                         struct p2p_channels *res)
 205 {
 206         os_memcpy(res, a, sizeof(*res));
 207         p2p_channels_union_inplace(res, b);
 208 }
 209
 210
 211 void p2p_channels_remove_freqs(struct p2p_channels *chan,
 212                                const struct wpa_freq_range_list *list)
 213 {
 214         size_t o, c;
 215
 216         if (list == NULL)
 217                 return;
 218
 219         o = 0;
 220         while (o < chan->reg_classes) {
 221                 struct p2p_reg_class *op = &chan->reg_class[o];
 222
 223                 c = 0;
 224                 while (c < op->channels) {
 225                         int freq = p2p_channel_to_freq(op->reg_class,
 226                                                        op->channel[c]);
 227                         if (freq > 0 && freq_range_list_includes(list, freq)) {
 228                                 op->channels--;
 229                                 os_memmove(&op->channel[c],
 230                                            &op->channel[c + 1],
 231                                            op->channels - c);
 232                         } else
 233                                 c++;
 234                 }
 235
 236                 if (op->channels == 0) {
 237                         chan->reg_classes--;
 238                         os_memmove(&chan->reg_class[o], &chan->reg_class[o + 1],
 239                                    (chan->reg_classes - o) *
 240                                    sizeof(struct p2p_reg_class));
 241                 } else
 242                         o++;
 243         }
 244 }
 245
 246
 247 /**
 248  * p2p_channels_includes - Check whether a channel is included in the list
 249  * @channels: List of supported channels
 250  * @reg_class: Regulatory class of the channel to search
 251  * @channel: Channel number of the channel to search
 252  * Returns: 1 if channel was found or 0 if not
 253  */
 254 int p2p_channels_includes(const struct p2p_channels *channels, u8 reg_class,
 255                           u8 channel)
 256 {
 257         size_t i, j;
 258         for (i = 0; i < channels->reg_classes; i++) {
 259                 const struct p2p_reg_class *reg = &channels->reg_class[i];
 260                 if (reg->reg_class != reg_class)
 261                         continue;
 262                 for (j = 0; j < reg->channels; j++) {
 263                         if (reg->channel[j] == channel)
 264                                 return 1;
 265                 }
 266         }
 267         return 0;
 268 }
 269
 270
 271 int p2p_channels_includes_freq(const struct p2p_channels *channels,
 272                                unsigned int freq)
 273 {
 274         size_t i, j;
 275         for (i = 0; i < channels->reg_classes; i++) {
 276                 const struct p2p_reg_class *reg = &channels->reg_class[i];
 277                 for (j = 0; j < reg->channels; j++) {
 278                         if (p2p_channel_to_freq(reg->reg_class,
 279                                                 reg->channel[j]) == (int) freq)
 280                                 return 1;
 281                 }
 282         }
 283         return 0;
 284 }
 285
 286
 287 int p2p_supported_freq(struct p2p_data *p2p, unsigned int freq)
 288 {
 289         u8 op_reg_class, op_channel;
 290         if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0)
 291                 return 0;
 292         return p2p_channels_includes(&p2p->cfg->channels, op_reg_class,
 293                                      op_channel);
 294 }
 295
 296
 297 int p2p_supported_freq_go(struct p2p_data *p2p, unsigned int freq)
 298 {
 299         u8 op_reg_class, op_channel;
 300         if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0)
 301                 return 0;
 302         return p2p_channels_includes(&p2p->cfg->channels, op_reg_class,
 303                                      op_channel) &&
 304                 !freq_range_list_includes(&p2p->no_go_freq, freq);
 305 }
 306
 307
 308 int p2p_supported_freq_cli(struct p2p_data *p2p, unsigned int freq)
 309 {
 310         u8 op_reg_class, op_channel;
 311         if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0)
 312                 return 0;
 313         return p2p_channels_includes(&p2p->cfg->channels, op_reg_class,
 314                                      op_channel) ||
 315                 p2p_channels_includes(&p2p->cfg->cli_channels, op_reg_class,
 316                                       op_channel);
 317 }
 318
 319
 320 unsigned int p2p_get_pref_freq(struct p2p_data *p2p,
 321                                const struct p2p_channels *channels)
 322 {
 323         unsigned int i;
 324         int freq = 0;
 325         const struct p2p_channels *tmpc = channels ?
 326                 channels : &p2p->cfg->channels;
 327
 328         if (tmpc == NULL)
 329                 return 0;
 330
 331         for (i = 0; p2p->cfg->pref_chan && i < p2p->cfg->num_pref_chan; i++) {
 332                 freq = p2p_channel_to_freq(p2p->cfg->pref_chan[i].op_class,
 333                                            p2p->cfg->pref_chan[i].chan);
 334                 if (p2p_channels_includes_freq(tmpc, freq))
 335                         return freq;
 336         }
 337         return 0;
 338 }
 339
 340
 341 void p2p_channels_dump(struct p2p_data *p2p, const char *title,
 342                        const struct p2p_channels *chan)
 343 {
 344         char buf[500], *pos, *end;
 345         size_t i, j;
 346         int ret;
 347
 348         pos = buf;
 349         end = pos + sizeof(buf);
 350
 351         for (i = 0; i < chan->reg_classes; i++) {
 352                 const struct p2p_reg_class *c;
 353                 c = &chan->reg_class[i];
 354                 ret = os_snprintf(pos, end - pos, " %u:", c->reg_class);
 355                 if (os_snprintf_error(end - pos, ret))
 356                         break;
 357                 pos += ret;
 358
 359                 for (j = 0; j < c->channels; j++) {
 360                         ret = os_snprintf(pos, end - pos, "%s%u",
 361                                           j == 0 ? "" : ",",
 362                                           c->channel[j]);
 363                         if (os_snprintf_error(end - pos, ret))
 364                                 break;
 365                         pos += ret;
 366                 }
 367         }
 368         *pos = '\0';
 369
 370         p2p_dbg(p2p, "%s:%s", title, buf);
 371 }
 372
 373
 374 static u8 p2p_channel_pick_random(const u8 *channels, unsigned int num_channels)
 375 {
 376         unsigned int r;
 377         if (os_get_random((u8 *) &r, sizeof(r)) < 0)
 378                 r = 0;
 379         r %= num_channels;
 380         return channels[r];
 381 }
 382
 383
 384 int p2p_channel_select(struct p2p_channels *chans, const int *classes,
 385                        u8 *op_class, u8 *op_channel)
 386 {
 387         unsigned int i, j;
 388
 389         for (j = 0; classes == NULL || classes[j]; j++) {
 390                 for (i = 0; i < chans->reg_classes; i++) {
 391                         struct p2p_reg_class *c = &chans->reg_class[i];
 392
 393                         if (c->channels == 0)
 394                                 continue;
 395
 396                         if (classes == NULL || c->reg_class == classes[j]) {
 397                                 /*
 398                                  * Pick one of the available channels in the
 399                                  * operating class at random.
 400                                  */
 401                                 *op_class = c->reg_class;
 402                                 *op_channel = p2p_channel_pick_random(
 403                                         c->channel, c->channels);
 404                                 return 0;
 405                         }
 406                 }
 407                 if (classes == NULL)
 408                         break;
 409         }
 410
 411         return -1;
 412 }
 413
 414
 415 int p2p_channel_random_social(struct p2p_channels *chans, u8 *op_class,
 416                               u8 *op_channel)
 417 {
 418         u8 chan[4];
 419         unsigned int num_channels = 0;
 420
 421         /* Try to find available social channels from 2.4 GHz */
 422         if (p2p_channels_includes(chans, 81, 1))
 423                 chan[num_channels++] = 1;
 424         if (p2p_channels_includes(chans, 81, 6))
 425                 chan[num_channels++] = 6;
 426         if (p2p_channels_includes(chans, 81, 11))
 427                 chan[num_channels++] = 11;
 428
 429         /* Try to find available social channels from 60 GHz */
 430         if (p2p_channels_includes(chans, 180, 2))
 431                 chan[num_channels++] = 2;
 432
 433         if (num_channels == 0)
 434                 return -1;
 435
 436         *op_channel = p2p_channel_pick_random(chan, num_channels);
 437         if (*op_channel == 2)
 438                 *op_class = 180;
 439         else
 440                 *op_class = 81;
 441
 442         return 0;
 443 }
 444
 445
 446 int p2p_channels_to_freqs(const struct p2p_channels *channels, int *freq_list,
 447                           unsigned int max_len)
 448 {
 449         unsigned int i, idx;
 450
 451         if (!channels || max_len == 0)
 452                 return 0;
 453
 454         for (i = 0, idx = 0; i < channels->reg_classes; i++) {
 455                 const struct p2p_reg_class *c = &channels->reg_class[i];
 456                 unsigned int j;
 457
 458                 if (idx + 1 == max_len)
 459                         break;
 460                 for (j = 0; j < c->channels; j++) {
 461                         int freq;
 462                         unsigned int k;
 463
 464                         if (idx + 1 == max_len)
 465                                 break;
 466                         freq = p2p_channel_to_freq(c->reg_class,
 467                                                    c->channel[j]);
 468                         if (freq < 0)
 469                                 continue;
 470
 471                         for (k = 0; k < idx; k++) {
 472                                 if (freq_list[k] == freq)
 473                                         break;
 474                         }
 475
 476                         if (k < idx)
 477                                 continue;
 478                         freq_list[idx++] = freq;
 479                 }
 480         }
 481
 482         freq_list[idx] = 0;
 483
 484         return idx;
 485 }