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 "p2p_i.h" 13 14 15 /** 16 * p2p_random - Generate random string for SSID and passphrase 17 * @buf: Buffer for returning the result 18 * @len: Number of octets to write to the buffer 19 * Returns: 0 on success, -1 on failure 20 * 21 * This function generates a random string using the following character set: 22 * 'A'-'Z', 'a'-'z', '0'-'9'. 23 */ 24 int p2p_random(char *buf, size_t len) 25 { 26 u8 val; 27 size_t i; 28 u8 letters = 'Z' - 'A' + 1; 29 u8 numbers = 10; 30 31 if (os_get_random((unsigned char *) buf, len)) 32 return -1; 33 /* Character set: 'A'-'Z', 'a'-'z', '0'-'9' */ 34 for (i = 0; i < len; i++) { 35 val = buf[i]; 36 val %= 2 * letters + numbers; 37 if (val < letters) 38 buf[i] = 'A' + val; 39 else if (val < 2 * letters) 40 buf[i] = 'a' + (val - letters); 41 else 42 buf[i] = '0' + (val - 2 * letters); 43 } 44 45 return 0; 46 } 47 48 49 /** 50 * p2p_channel_to_freq - Convert channel info to frequency 51 * @op_class: Operating class 52 * @channel: Channel number 53 * Returns: Frequency in MHz or -1 if the specified channel is unknown 54 */ 55 int p2p_channel_to_freq(int op_class, int channel) 56 { 57 /* Table E-4 in IEEE Std 802.11-2012 - Global operating classes */ 58 /* TODO: more operating classes */ 59 switch (op_class) { 60 case 81: 61 /* channels 1..13 */ 62 if (channel < 1 || channel > 13) 63 return -1; 64 return 2407 + 5 * channel; 65 case 82: 66 /* channel 14 */ 67 if (channel != 14) 68 return -1; 69 return 2414 + 5 * channel; 70 case 83: /* channels 1..9; 40 MHz */ 71 case 84: /* channels 5..13; 40 MHz */ 72 if (channel < 1 || channel > 13) 73 return -1; 74 return 2407 + 5 * channel; 75 case 115: /* channels 36,40,44,48; indoor only */ 76 case 118: /* channels 52,56,60,64; dfs */ 77 if (channel < 36 || channel > 64) 78 return -1; 79 return 5000 + 5 * channel; 80 case 124: /* channels 149,153,157,161 */ 81 case 125: /* channels 149,153,157,161,165,169 */ 82 if (channel < 149 || channel > 161) 83 return -1; 84 return 5000 + 5 * channel; 85 case 116: /* channels 36,44; 40 MHz; indoor only */ 86 case 117: /* channels 40,48; 40 MHz; indoor only */ 87 case 119: /* channels 52,60; 40 MHz; dfs */ 88 case 120: /* channels 56,64; 40 MHz; dfs */ 89 if (channel < 36 || channel > 64) 90 return -1; 91 return 5000 + 5 * channel; 92 case 126: /* channels 149,157; 40 MHz */ 93 case 127: /* channels 153,161; 40 MHz */ 94 if (channel < 149 || channel > 161) 95 return -1; 96 return 5000 + 5 * channel; 97 case 128: /* center freqs 42, 58, 106, 122, 138, 155; 80 MHz */ 98 if (channel < 36 || channel > 161) 99 return -1; 100 return 5000 + 5 * channel; 101 case 180: /* 60 GHz band, channels 1..4 */ 102 if (channel < 1 || channel > 4) 103 return -1; 104 return 56160 + 2160 * channel; 105 } 106 return -1; 107 } 108 109 110 /** 111 * p2p_freq_to_channel - Convert frequency into channel info 112 * @op_class: Buffer for returning operating class 113 * @channel: Buffer for returning channel number 114 * Returns: 0 on success, -1 if the specified frequency is unknown 115 */ 116 int p2p_freq_to_channel(unsigned int freq, u8 *op_class, u8 *channel) 117 { 118 /* TODO: more operating classes */ 119 if (freq >= 2412 && freq <= 2472) { 120 if ((freq - 2407) % 5) 121 return -1; 122 123 *op_class = 81; /* 2.407 GHz, channels 1..13 */ 124 *channel = (freq - 2407) / 5; 125 return 0; 126 } 127 128 if (freq == 2484) { 129 *op_class = 82; /* channel 14 */ 130 *channel = 14; 131 return 0; 132 } 133 134 if (freq >= 5180 && freq <= 5240) { 135 if ((freq - 5000) % 5) 136 return -1; 137 138 *op_class = 115; /* 5 GHz, channels 36..48 */ 139 *channel = (freq - 5000) / 5; 140 return 0; 141 } 142 143 if (freq >= 5745 && freq <= 5805) { 144 if ((freq - 5000) % 5) 145 return -1; 146 147 *op_class = 124; /* 5 GHz, channels 149..161 */ 148 *channel = (freq - 5000) / 5; 149 return 0; 150 } 151 152 if (freq >= 58320 && freq <= 64800) { 153 if ((freq - 58320) % 2160) 154 return -1; 155 156 *op_class = 180; /* 60 GHz, channels 1..4 */ 157 *channel = (freq - 56160) / 2160; 158 return 0; 159 } 160 161 return -1; 162 } 163 164 165 static void p2p_reg_class_intersect(const struct p2p_reg_class *a, 166 const struct p2p_reg_class *b, 167 struct p2p_reg_class *res) 168 { 169 size_t i, j; 170 171 res->reg_class = a->reg_class; 172 173 for (i = 0; i < a->channels; i++) { 174 for (j = 0; j < b->channels; j++) { 175 if (a->channel[i] != b->channel[j]) 176 continue; 177 res->channel[res->channels] = a->channel[i]; 178 res->channels++; 179 if (res->channels == P2P_MAX_REG_CLASS_CHANNELS) 180 return; 181 } 182 } 183 } 184 185 186 /** 187 * p2p_channels_intersect - Intersection of supported channel lists 188 * @a: First set of supported channels 189 * @b: Second set of supported channels 190 * @res: Data structure for returning the intersection of support channels 191 * 192 * This function can be used to find a common set of supported channels. Both 193 * input channels sets are assumed to use the same country code. If different 194 * country codes are used, the regulatory class numbers may not be matched 195 * correctly and results are undefined. 196 */ 197 void p2p_channels_intersect(const struct p2p_channels *a, 198 const struct p2p_channels *b, 199 struct p2p_channels *res) 200 { 201 size_t i, j; 202 203 os_memset(res, 0, sizeof(*res)); 204 205 for (i = 0; i < a->reg_classes; i++) { 206 const struct p2p_reg_class *a_reg = &a->reg_class[i]; 207 for (j = 0; j < b->reg_classes; j++) { 208 const struct p2p_reg_class *b_reg = &b->reg_class[j]; 209 if (a_reg->reg_class != b_reg->reg_class) 210 continue; 211 p2p_reg_class_intersect( 212 a_reg, b_reg, 213 &res->reg_class[res->reg_classes]); 214 if (res->reg_class[res->reg_classes].channels) { 215 res->reg_classes++; 216 if (res->reg_classes == P2P_MAX_REG_CLASSES) 217 return; 218 } 219 } 220 } 221 } 222 223 224 static void p2p_op_class_union(struct p2p_reg_class *cl, 225 const struct p2p_reg_class *b_cl) 226 { 227 size_t i, j; 228 229 for (i = 0; i < b_cl->channels; i++) { 230 for (j = 0; j < cl->channels; j++) { 231 if (b_cl->channel[i] == cl->channel[j]) 232 break; 233 } 234 if (j == cl->channels) { 235 if (cl->channels == P2P_MAX_REG_CLASS_CHANNELS) 236 return; 237 cl->channel[cl->channels++] = b_cl->channel[i]; 238 } 239 } 240 } 241 242 243 /** 244 * p2p_channels_union - Union of channel lists 245 * @a: First set of channels 246 * @b: Second set of channels 247 * @res: Data structure for returning the union of channels 248 */ 249 void p2p_channels_union(const struct p2p_channels *a, 250 const struct p2p_channels *b, 251 struct p2p_channels *res) 252 { 253 size_t i, j; 254 255 if (a != res) 256 os_memcpy(res, a, sizeof(*res)); 257 258 for (i = 0; i < res->reg_classes; i++) { 259 struct p2p_reg_class *cl = &res->reg_class[i]; 260 for (j = 0; j < b->reg_classes; j++) { 261 const struct p2p_reg_class *b_cl = &b->reg_class[j]; 262 if (cl->reg_class != b_cl->reg_class) 263 continue; 264 p2p_op_class_union(cl, b_cl); 265 } 266 } 267 268 for (j = 0; j < b->reg_classes; j++) { 269 const struct p2p_reg_class *b_cl = &b->reg_class[j]; 270 271 for (i = 0; i < res->reg_classes; i++) { 272 struct p2p_reg_class *cl = &res->reg_class[i]; 273 if (cl->reg_class == b_cl->reg_class) 274 break; 275 } 276 277 if (i == res->reg_classes) { 278 if (res->reg_classes == P2P_MAX_REG_CLASSES) 279 return; 280 os_memcpy(&res->reg_class[res->reg_classes++], 281 b_cl, sizeof(struct p2p_reg_class)); 282 } 283 } 284 } 285 286 287 void p2p_channels_remove_freqs(struct p2p_channels *chan, 288 const struct wpa_freq_range_list *list) 289 { 290 size_t o, c; 291 292 if (list == NULL) 293 return; 294 295 o = 0; 296 while (o < chan->reg_classes) { 297 struct p2p_reg_class *op = &chan->reg_class[o]; 298 299 c = 0; 300 while (c < op->channels) { 301 int freq = p2p_channel_to_freq(op->reg_class, 302 op->channel[c]); 303 if (freq > 0 && freq_range_list_includes(list, freq)) { 304 op->channels--; 305 os_memmove(&op->channel[c], 306 &op->channel[c + 1], 307 op->channels - c); 308 } else 309 c++; 310 } 311 312 if (op->channels == 0) { 313 chan->reg_classes--; 314 os_memmove(&chan->reg_class[o], &chan->reg_class[o + 1], 315 (chan->reg_classes - o) * 316 sizeof(struct p2p_reg_class)); 317 } else 318 o++; 319 } 320 } 321 322 323 /** 324 * p2p_channels_includes - Check whether a channel is included in the list 325 * @channels: List of supported channels 326 * @reg_class: Regulatory class of the channel to search 327 * @channel: Channel number of the channel to search 328 * Returns: 1 if channel was found or 0 if not 329 */ 330 int p2p_channels_includes(const struct p2p_channels *channels, u8 reg_class, 331 u8 channel) 332 { 333 size_t i, j; 334 for (i = 0; i < channels->reg_classes; i++) { 335 const struct p2p_reg_class *reg = &channels->reg_class[i]; 336 if (reg->reg_class != reg_class) 337 continue; 338 for (j = 0; j < reg->channels; j++) { 339 if (reg->channel[j] == channel) 340 return 1; 341 } 342 } 343 return 0; 344 } 345 346 347 int p2p_channels_includes_freq(const struct p2p_channels *channels, 348 unsigned int freq) 349 { 350 size_t i, j; 351 for (i = 0; i < channels->reg_classes; i++) { 352 const struct p2p_reg_class *reg = &channels->reg_class[i]; 353 for (j = 0; j < reg->channels; j++) { 354 if (p2p_channel_to_freq(reg->reg_class, 355 reg->channel[j]) == (int) freq) 356 return 1; 357 } 358 } 359 return 0; 360 } 361 362 363 int p2p_supported_freq(struct p2p_data *p2p, unsigned int freq) 364 { 365 u8 op_reg_class, op_channel; 366 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0) 367 return 0; 368 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class, 369 op_channel); 370 } 371 372 373 int p2p_supported_freq_go(struct p2p_data *p2p, unsigned int freq) 374 { 375 u8 op_reg_class, op_channel; 376 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0) 377 return 0; 378 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class, 379 op_channel) && 380 !freq_range_list_includes(&p2p->no_go_freq, freq); 381 } 382 383 384 int p2p_supported_freq_cli(struct p2p_data *p2p, unsigned int freq) 385 { 386 u8 op_reg_class, op_channel; 387 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0) 388 return 0; 389 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class, 390 op_channel) || 391 p2p_channels_includes(&p2p->cfg->cli_channels, op_reg_class, 392 op_channel); 393 } 394 395 396 unsigned int p2p_get_pref_freq(struct p2p_data *p2p, 397 const struct p2p_channels *channels) 398 { 399 unsigned int i; 400 int freq = 0; 401 const struct p2p_channels *tmpc = channels ? 402 channels : &p2p->cfg->channels; 403 404 if (tmpc == NULL) 405 return 0; 406 407 for (i = 0; p2p->cfg->pref_chan && i < p2p->cfg->num_pref_chan; i++) { 408 freq = p2p_channel_to_freq(p2p->cfg->pref_chan[i].op_class, 409 p2p->cfg->pref_chan[i].chan); 410 if (p2p_channels_includes_freq(tmpc, freq)) 411 return freq; 412 } 413 return 0; 414 } 415 416 417 void p2p_channels_dump(struct p2p_data *p2p, const char *title, 418 const struct p2p_channels *chan) 419 { 420 char buf[500], *pos, *end; 421 size_t i, j; 422 int ret; 423 424 pos = buf; 425 end = pos + sizeof(buf); 426 427 for (i = 0; i < chan->reg_classes; i++) { 428 const struct p2p_reg_class *c; 429 c = &chan->reg_class[i]; 430 ret = os_snprintf(pos, end - pos, " %u:", c->reg_class); 431 if (ret < 0 || ret >= end - pos) 432 break; 433 pos += ret; 434 435 for (j = 0; j < c->channels; j++) { 436 ret = os_snprintf(pos, end - pos, "%s%u", 437 j == 0 ? "" : ",", 438 c->channel[j]); 439 if (ret < 0 || ret >= end - pos) 440 break; 441 pos += ret; 442 } 443 } 444 *pos = '\0'; 445 446 p2p_dbg(p2p, "%s:%s", title, buf); 447 } 448 449 450 static u8 p2p_channel_pick_random(const u8 *channels, unsigned int num_channels) 451 { 452 unsigned int r; 453 if (os_get_random((u8 *) &r, sizeof(r)) < 0) 454 r = 0; 455 r %= num_channels; 456 return channels[r]; 457 } 458 459 460 int p2p_channel_select(struct p2p_channels *chans, const int *classes, 461 u8 *op_class, u8 *op_channel) 462 { 463 unsigned int i, j; 464 465 for (j = 0; classes == NULL || classes[j]; j++) { 466 for (i = 0; i < chans->reg_classes; i++) { 467 struct p2p_reg_class *c = &chans->reg_class[i]; 468 469 if (c->channels == 0) 470 continue; 471 472 if (classes == NULL || c->reg_class == classes[j]) { 473 /* 474 * Pick one of the available channels in the 475 * operating class at random. 476 */ 477 *op_class = c->reg_class; 478 *op_channel = p2p_channel_pick_random( 479 c->channel, c->channels); 480 return 0; 481 } 482 } 483 if (classes == NULL) 484 break; 485 } 486 487 return -1; 488 } 489 490 491 int p2p_channel_random_social(struct p2p_channels *chans, u8 *op_class, 492 u8 *op_channel) 493 { 494 u8 chan[4]; 495 unsigned int num_channels = 0; 496 497 /* Try to find available social channels from 2.4 GHz */ 498 if (p2p_channels_includes(chans, 81, 1)) 499 chan[num_channels++] = 1; 500 if (p2p_channels_includes(chans, 81, 6)) 501 chan[num_channels++] = 6; 502 if (p2p_channels_includes(chans, 81, 11)) 503 chan[num_channels++] = 11; 504 505 /* Try to find available social channels from 60 GHz */ 506 if (p2p_channels_includes(chans, 180, 2)) 507 chan[num_channels++] = 2; 508 509 if (num_channels == 0) 510 return -1; 511 512 *op_channel = p2p_channel_pick_random(chan, num_channels); 513 if (*op_channel == 2) 514 *op_class = 180; 515 else 516 *op_class = 81; 517 518 return 0; 519 } 520
