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/ieee802_11_common.h" 13 #include "p2p_i.h" 14 15 16 /** 17 * p2p_random - Generate random string for SSID and passphrase 18 * @buf: Buffer for returning the result 19 * @len: Number of octets to write to the buffer 20 * Returns: 0 on success, -1 on failure 21 * 22 * This function generates a random string using the following character set: 23 * 'A'-'Z', 'a'-'z', '0'-'9'. 24 */ 25 int p2p_random(char *buf, size_t len) 26 { 27 u8 val; 28 size_t i; 29 u8 letters = 'Z' - 'A' + 1; 30 u8 numbers = 10; 31 32 if (os_get_random((unsigned char *) buf, len)) 33 return -1; 34 /* Character set: 'A'-'Z', 'a'-'z', '0'-'9' */ 35 for (i = 0; i < len; i++) { 36 val = buf[i]; 37 val %= 2 * letters + numbers; 38 if (val < letters) 39 buf[i] = 'A' + val; 40 else if (val < 2 * letters) 41 buf[i] = 'a' + (val - letters); 42 else 43 buf[i] = '0' + (val - 2 * letters); 44 } 45 46 return 0; 47 } 48 49 50 /** 51 * p2p_channel_to_freq - Convert channel info to frequency 52 * @op_class: Operating class 53 * @channel: Channel number 54 * Returns: Frequency in MHz or -1 if the specified channel is unknown 55 */ 56 int p2p_channel_to_freq(int op_class, int channel) 57 { 58 return ieee80211_chan_to_freq(NULL, op_class, channel); 59 } 60 61 62 /** 63 * p2p_freq_to_channel - Convert frequency into channel info 64 * @op_class: Buffer for returning operating class 65 * @channel: Buffer for returning channel number 66 * Returns: 0 on success, -1 if the specified frequency is unknown 67 */ 68 int p2p_freq_to_channel(unsigned int freq, u8 *op_class, u8 *channel) 69 { 70 /* TODO: more operating classes */ 71 if (freq >= 2412 && freq <= 2472) { 72 if ((freq - 2407) % 5) 73 return -1; 74 75 *op_class = 81; /* 2.407 GHz, channels 1..13 */ 76 *channel = (freq - 2407) / 5; 77 return 0; 78 } 79 80 if (freq == 2484) { 81 *op_class = 82; /* channel 14 */ 82 *channel = 14; 83 return 0; 84 } 85 86 if (freq >= 5180 && freq <= 5240) { 87 if ((freq - 5000) % 5) 88 return -1; 89 90 *op_class = 115; /* 5 GHz, channels 36..48 */ 91 *channel = (freq - 5000) / 5; 92 return 0; 93 } 94 95 if (freq >= 5745 && freq <= 5805) { 96 if ((freq - 5000) % 5) 97 return -1; 98 99 *op_class = 124; /* 5 GHz, channels 149..161 */ 100 *channel = (freq - 5000) / 5; 101 return 0; 102 } 103 104 if (freq >= 58320 && freq <= 64800) { 105 if ((freq - 58320) % 2160) 106 return -1; 107 108 *op_class = 180; /* 60 GHz, channels 1..4 */ 109 *channel = (freq - 56160) / 2160; 110 return 0; 111 } 112 113 return -1; 114 } 115 116 117 static void p2p_reg_class_intersect(const struct p2p_reg_class *a, 118 const struct p2p_reg_class *b, 119 struct p2p_reg_class *res) 120 { 121 size_t i, j; 122 123 res->reg_class = a->reg_class; 124 125 for (i = 0; i < a->channels; i++) { 126 for (j = 0; j < b->channels; j++) { 127 if (a->channel[i] != b->channel[j]) 128 continue; 129 res->channel[res->channels] = a->channel[i]; 130 res->channels++; 131 if (res->channels == P2P_MAX_REG_CLASS_CHANNELS) 132 return; 133 } 134 } 135 } 136 137 138 /** 139 * p2p_channels_intersect - Intersection of supported channel lists 140 * @a: First set of supported channels 141 * @b: Second set of supported channels 142 * @res: Data structure for returning the intersection of support channels 143 * 144 * This function can be used to find a common set of supported channels. Both 145 * input channels sets are assumed to use the same country code. If different 146 * country codes are used, the regulatory class numbers may not be matched 147 * correctly and results are undefined. 148 */ 149 void p2p_channels_intersect(const struct p2p_channels *a, 150 const struct p2p_channels *b, 151 struct p2p_channels *res) 152 { 153 size_t i, j; 154 155 os_memset(res, 0, sizeof(*res)); 156 157 for (i = 0; i < a->reg_classes; i++) { 158 const struct p2p_reg_class *a_reg = &a->reg_class[i]; 159 for (j = 0; j < b->reg_classes; j++) { 160 const struct p2p_reg_class *b_reg = &b->reg_class[j]; 161 if (a_reg->reg_class != b_reg->reg_class) 162 continue; 163 p2p_reg_class_intersect( 164 a_reg, b_reg, 165 &res->reg_class[res->reg_classes]); 166 if (res->reg_class[res->reg_classes].channels) { 167 res->reg_classes++; 168 if (res->reg_classes == P2P_MAX_REG_CLASSES) 169 return; 170 } 171 } 172 } 173 } 174 175 176 static void p2p_op_class_union(struct p2p_reg_class *cl, 177 const struct p2p_reg_class *b_cl) 178 { 179 size_t i, j; 180 181 for (i = 0; i < b_cl->channels; i++) { 182 for (j = 0; j < cl->channels; j++) { 183 if (b_cl->channel[i] == cl->channel[j]) 184 break; 185 } 186 if (j == cl->channels) { 187 if (cl->channels == P2P_MAX_REG_CLASS_CHANNELS) 188 return; 189 cl->channel[cl->channels++] = b_cl->channel[i]; 190 } 191 } 192 } 193 194 195 /** 196 * p2p_channels_union_inplace - Inplace union of channel lists 197 * @res: Input data and place for returning union of the channel sets 198 * @b: Second set of channels 199 */ 200 void p2p_channels_union_inplace(struct p2p_channels *res, 201 const struct p2p_channels *b) 202 { 203 size_t i, j; 204 205 for (i = 0; i < res->reg_classes; i++) { 206 struct p2p_reg_class *cl = &res->reg_class[i]; 207 for (j = 0; j < b->reg_classes; j++) { 208 const struct p2p_reg_class *b_cl = &b->reg_class[j]; 209 if (cl->reg_class != b_cl->reg_class) 210 continue; 211 p2p_op_class_union(cl, b_cl); 212 } 213 } 214 215 for (j = 0; j < b->reg_classes; j++) { 216 const struct p2p_reg_class *b_cl = &b->reg_class[j]; 217 218 for (i = 0; i < res->reg_classes; i++) { 219 struct p2p_reg_class *cl = &res->reg_class[i]; 220 if (cl->reg_class == b_cl->reg_class) 221 break; 222 } 223 224 if (i == res->reg_classes) { 225 if (res->reg_classes == P2P_MAX_REG_CLASSES) 226 return; 227 os_memcpy(&res->reg_class[res->reg_classes++], 228 b_cl, sizeof(struct p2p_reg_class)); 229 } 230 } 231 } 232 233 234 /** 235 * p2p_channels_union - Union of channel lists 236 * @a: First set of channels 237 * @b: Second set of channels 238 * @res: Data structure for returning the union of channels 239 */ 240 void p2p_channels_union(const struct p2p_channels *a, 241 const struct p2p_channels *b, 242 struct p2p_channels *res) 243 { 244 os_memcpy(res, a, sizeof(*res)); 245 p2p_channels_union_inplace(res, b); 246 } 247 248 249 void p2p_channels_remove_freqs(struct p2p_channels *chan, 250 const struct wpa_freq_range_list *list) 251 { 252 size_t o, c; 253 254 if (list == NULL) 255 return; 256 257 o = 0; 258 while (o < chan->reg_classes) { 259 struct p2p_reg_class *op = &chan->reg_class[o]; 260 261 c = 0; 262 while (c < op->channels) { 263 int freq = p2p_channel_to_freq(op->reg_class, 264 op->channel[c]); 265 if (freq > 0 && freq_range_list_includes(list, freq)) { 266 op->channels--; 267 os_memmove(&op->channel[c], 268 &op->channel[c + 1], 269 op->channels - c); 270 } else 271 c++; 272 } 273 274 if (op->channels == 0) { 275 chan->reg_classes--; 276 os_memmove(&chan->reg_class[o], &chan->reg_class[o + 1], 277 (chan->reg_classes - o) * 278 sizeof(struct p2p_reg_class)); 279 } else 280 o++; 281 } 282 } 283 284 285 /** 286 * p2p_channels_includes - Check whether a channel is included in the list 287 * @channels: List of supported channels 288 * @reg_class: Regulatory class of the channel to search 289 * @channel: Channel number of the channel to search 290 * Returns: 1 if channel was found or 0 if not 291 */ 292 int p2p_channels_includes(const struct p2p_channels *channels, u8 reg_class, 293 u8 channel) 294 { 295 size_t i, j; 296 for (i = 0; i < channels->reg_classes; i++) { 297 const struct p2p_reg_class *reg = &channels->reg_class[i]; 298 if (reg->reg_class != reg_class) 299 continue; 300 for (j = 0; j < reg->channels; j++) { 301 if (reg->channel[j] == channel) 302 return 1; 303 } 304 } 305 return 0; 306 } 307 308 309 int p2p_channels_includes_freq(const struct p2p_channels *channels, 310 unsigned int freq) 311 { 312 size_t i, j; 313 for (i = 0; i < channels->reg_classes; i++) { 314 const struct p2p_reg_class *reg = &channels->reg_class[i]; 315 for (j = 0; j < reg->channels; j++) { 316 if (p2p_channel_to_freq(reg->reg_class, 317 reg->channel[j]) == (int) freq) 318 return 1; 319 } 320 } 321 return 0; 322 } 323 324 325 int p2p_supported_freq(struct p2p_data *p2p, unsigned int freq) 326 { 327 u8 op_reg_class, op_channel; 328 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0) 329 return 0; 330 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class, 331 op_channel); 332 } 333 334 335 int p2p_supported_freq_go(struct p2p_data *p2p, unsigned int freq) 336 { 337 u8 op_reg_class, op_channel; 338 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0) 339 return 0; 340 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class, 341 op_channel) && 342 !freq_range_list_includes(&p2p->no_go_freq, freq); 343 } 344 345 346 int p2p_supported_freq_cli(struct p2p_data *p2p, unsigned int freq) 347 { 348 u8 op_reg_class, op_channel; 349 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0) 350 return 0; 351 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class, 352 op_channel) || 353 p2p_channels_includes(&p2p->cfg->cli_channels, op_reg_class, 354 op_channel); 355 } 356 357 358 unsigned int p2p_get_pref_freq(struct p2p_data *p2p, 359 const struct p2p_channels *channels) 360 { 361 unsigned int i; 362 int freq = 0; 363 const struct p2p_channels *tmpc = channels ? 364 channels : &p2p->cfg->channels; 365 366 if (tmpc == NULL) 367 return 0; 368 369 for (i = 0; p2p->cfg->pref_chan && i < p2p->cfg->num_pref_chan; i++) { 370 freq = p2p_channel_to_freq(p2p->cfg->pref_chan[i].op_class, 371 p2p->cfg->pref_chan[i].chan); 372 if (p2p_channels_includes_freq(tmpc, freq)) 373 return freq; 374 } 375 return 0; 376 } 377 378 379 void p2p_channels_dump(struct p2p_data *p2p, const char *title, 380 const struct p2p_channels *chan) 381 { 382 char buf[500], *pos, *end; 383 size_t i, j; 384 int ret; 385 386 pos = buf; 387 end = pos + sizeof(buf); 388 389 for (i = 0; i < chan->reg_classes; i++) { 390 const struct p2p_reg_class *c; 391 c = &chan->reg_class[i]; 392 ret = os_snprintf(pos, end - pos, " %u:", c->reg_class); 393 if (os_snprintf_error(end - pos, ret)) 394 break; 395 pos += ret; 396 397 for (j = 0; j < c->channels; j++) { 398 ret = os_snprintf(pos, end - pos, "%s%u", 399 j == 0 ? "" : ",", 400 c->channel[j]); 401 if (os_snprintf_error(end - pos, ret)) 402 break; 403 pos += ret; 404 } 405 } 406 *pos = '\0'; 407 408 p2p_dbg(p2p, "%s:%s", title, buf); 409 } 410 411 412 static u8 p2p_channel_pick_random(const u8 *channels, unsigned int num_channels) 413 { 414 unsigned int r; 415 if (os_get_random((u8 *) &r, sizeof(r)) < 0) 416 r = 0; 417 r %= num_channels; 418 return channels[r]; 419 } 420 421 422 int p2p_channel_select(struct p2p_channels *chans, const int *classes, 423 u8 *op_class, u8 *op_channel) 424 { 425 unsigned int i, j; 426 427 for (j = 0; classes == NULL || classes[j]; j++) { 428 for (i = 0; i < chans->reg_classes; i++) { 429 struct p2p_reg_class *c = &chans->reg_class[i]; 430 431 if (c->channels == 0) 432 continue; 433 434 if (classes == NULL || c->reg_class == classes[j]) { 435 /* 436 * Pick one of the available channels in the 437 * operating class at random. 438 */ 439 *op_class = c->reg_class; 440 *op_channel = p2p_channel_pick_random( 441 c->channel, c->channels); 442 return 0; 443 } 444 } 445 if (classes == NULL) 446 break; 447 } 448 449 return -1; 450 } 451 452 453 int p2p_channel_random_social(struct p2p_channels *chans, u8 *op_class, 454 u8 *op_channel) 455 { 456 u8 chan[4]; 457 unsigned int num_channels = 0; 458 459 /* Try to find available social channels from 2.4 GHz */ 460 if (p2p_channels_includes(chans, 81, 1)) 461 chan[num_channels++] = 1; 462 if (p2p_channels_includes(chans, 81, 6)) 463 chan[num_channels++] = 6; 464 if (p2p_channels_includes(chans, 81, 11)) 465 chan[num_channels++] = 11; 466 467 /* Try to find available social channels from 60 GHz */ 468 if (p2p_channels_includes(chans, 180, 2)) 469 chan[num_channels++] = 2; 470 471 if (num_channels == 0) 472 return -1; 473 474 *op_channel = p2p_channel_pick_random(chan, num_channels); 475 if (*op_channel == 2) 476 *op_class = 180; 477 else 478 *op_class = 81; 479 480 return 0; 481 } 482 483 484 int p2p_channels_to_freqs(const struct p2p_channels *channels, int *freq_list, 485 unsigned int max_len) 486 { 487 unsigned int i, idx; 488 489 if (!channels || max_len == 0) 490 return 0; 491 492 for (i = 0, idx = 0; i < channels->reg_classes; i++) { 493 const struct p2p_reg_class *c = &channels->reg_class[i]; 494 unsigned int j; 495 496 if (idx + 1 == max_len) 497 break; 498 for (j = 0; j < c->channels; j++) { 499 int freq; 500 if (idx + 1 == max_len) 501 break; 502 freq = p2p_channel_to_freq(c->reg_class, 503 c->channel[j]); 504 if (freq < 0) 505 continue; 506 freq_list[idx++] = freq; 507 } 508 } 509 510 freq_list[idx] = 0; 511 512 return idx; 513 } 514