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 return -1; 153 } 154 155 156 static void p2p_reg_class_intersect(const struct p2p_reg_class *a, 157 const struct p2p_reg_class *b, 158 struct p2p_reg_class *res) 159 { 160 size_t i, j; 161 162 res->reg_class = a->reg_class; 163 164 for (i = 0; i < a->channels; i++) { 165 for (j = 0; j < b->channels; j++) { 166 if (a->channel[i] != b->channel[j]) 167 continue; 168 res->channel[res->channels] = a->channel[i]; 169 res->channels++; 170 if (res->channels == P2P_MAX_REG_CLASS_CHANNELS) 171 return; 172 } 173 } 174 } 175 176 177 /** 178 * p2p_channels_intersect - Intersection of supported channel lists 179 * @a: First set of supported channels 180 * @b: Second set of supported channels 181 * @res: Data structure for returning the intersection of support channels 182 * 183 * This function can be used to find a common set of supported channels. Both 184 * input channels sets are assumed to use the same country code. If different 185 * country codes are used, the regulatory class numbers may not be matched 186 * correctly and results are undefined. 187 */ 188 void p2p_channels_intersect(const struct p2p_channels *a, 189 const struct p2p_channels *b, 190 struct p2p_channels *res) 191 { 192 size_t i, j; 193 194 os_memset(res, 0, sizeof(*res)); 195 196 for (i = 0; i < a->reg_classes; i++) { 197 const struct p2p_reg_class *a_reg = &a->reg_class[i]; 198 for (j = 0; j < b->reg_classes; j++) { 199 const struct p2p_reg_class *b_reg = &b->reg_class[j]; 200 if (a_reg->reg_class != b_reg->reg_class) 201 continue; 202 p2p_reg_class_intersect( 203 a_reg, b_reg, 204 &res->reg_class[res->reg_classes]); 205 if (res->reg_class[res->reg_classes].channels) { 206 res->reg_classes++; 207 if (res->reg_classes == P2P_MAX_REG_CLASSES) 208 return; 209 } 210 } 211 } 212 } 213 214 215 static void p2p_op_class_union(struct p2p_reg_class *cl, 216 const struct p2p_reg_class *b_cl) 217 { 218 size_t i, j; 219 220 for (i = 0; i < b_cl->channels; i++) { 221 for (j = 0; j < cl->channels; j++) { 222 if (b_cl->channel[i] == cl->channel[j]) 223 break; 224 } 225 if (j == cl->channels) { 226 if (cl->channels == P2P_MAX_REG_CLASS_CHANNELS) 227 return; 228 cl->channel[cl->channels++] = b_cl->channel[i]; 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 size_t i, j; 245 246 if (a != res) 247 os_memcpy(res, a, sizeof(*res)); 248 249 for (i = 0; i < res->reg_classes; i++) { 250 struct p2p_reg_class *cl = &res->reg_class[i]; 251 for (j = 0; j < b->reg_classes; j++) { 252 const struct p2p_reg_class *b_cl = &b->reg_class[j]; 253 if (cl->reg_class != b_cl->reg_class) 254 continue; 255 p2p_op_class_union(cl, b_cl); 256 } 257 } 258 259 for (j = 0; j < b->reg_classes; j++) { 260 const struct p2p_reg_class *b_cl = &b->reg_class[j]; 261 262 for (i = 0; i < res->reg_classes; i++) { 263 struct p2p_reg_class *cl = &res->reg_class[i]; 264 if (cl->reg_class == b_cl->reg_class) 265 break; 266 } 267 268 if (i == res->reg_classes) { 269 if (res->reg_classes == P2P_MAX_REG_CLASSES) 270 return; 271 os_memcpy(&res->reg_class[res->reg_classes++], 272 b_cl, sizeof(struct p2p_reg_class)); 273 } 274 } 275 } 276 277 278 void p2p_channels_remove_freqs(struct p2p_channels *chan, 279 const struct wpa_freq_range_list *list) 280 { 281 size_t o, c; 282 283 if (list == NULL) 284 return; 285 286 o = 0; 287 while (o < chan->reg_classes) { 288 struct p2p_reg_class *op = &chan->reg_class[o]; 289 290 c = 0; 291 while (c < op->channels) { 292 int freq = p2p_channel_to_freq(op->reg_class, 293 op->channel[c]); 294 if (freq > 0 && freq_range_list_includes(list, freq)) { 295 op->channels--; 296 os_memmove(&op->channel[c], 297 &op->channel[c + 1], 298 op->channels - c); 299 } else 300 c++; 301 } 302 303 if (op->channels == 0) { 304 chan->reg_classes--; 305 os_memmove(&chan->reg_class[o], &chan->reg_class[o + 1], 306 (chan->reg_classes - o) * 307 sizeof(struct p2p_reg_class)); 308 } else 309 o++; 310 } 311 } 312 313 314 /** 315 * p2p_channels_includes - Check whether a channel is included in the list 316 * @channels: List of supported channels 317 * @reg_class: Regulatory class of the channel to search 318 * @channel: Channel number of the channel to search 319 * Returns: 1 if channel was found or 0 if not 320 */ 321 int p2p_channels_includes(const struct p2p_channels *channels, u8 reg_class, 322 u8 channel) 323 { 324 size_t i, j; 325 for (i = 0; i < channels->reg_classes; i++) { 326 const struct p2p_reg_class *reg = &channels->reg_class[i]; 327 if (reg->reg_class != reg_class) 328 continue; 329 for (j = 0; j < reg->channels; j++) { 330 if (reg->channel[j] == channel) 331 return 1; 332 } 333 } 334 return 0; 335 } 336 337 338 int p2p_channels_includes_freq(const struct p2p_channels *channels, 339 unsigned int freq) 340 { 341 size_t i, j; 342 for (i = 0; i < channels->reg_classes; i++) { 343 const struct p2p_reg_class *reg = &channels->reg_class[i]; 344 for (j = 0; j < reg->channels; j++) { 345 if (p2p_channel_to_freq(reg->reg_class, 346 reg->channel[j]) == (int) freq) 347 return 1; 348 } 349 } 350 return 0; 351 } 352 353 354 int p2p_supported_freq(struct p2p_data *p2p, unsigned int freq) 355 { 356 u8 op_reg_class, op_channel; 357 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0) 358 return 0; 359 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class, 360 op_channel); 361 } 362 363 364 int p2p_supported_freq_go(struct p2p_data *p2p, unsigned int freq) 365 { 366 u8 op_reg_class, op_channel; 367 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0) 368 return 0; 369 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class, 370 op_channel) && 371 !freq_range_list_includes(&p2p->no_go_freq, freq); 372 } 373 374 375 int p2p_supported_freq_cli(struct p2p_data *p2p, unsigned int freq) 376 { 377 u8 op_reg_class, op_channel; 378 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0) 379 return 0; 380 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class, 381 op_channel) || 382 p2p_channels_includes(&p2p->cfg->cli_channels, op_reg_class, 383 op_channel); 384 } 385 386 387 unsigned int p2p_get_pref_freq(struct p2p_data *p2p, 388 const struct p2p_channels *channels) 389 { 390 unsigned int i; 391 int freq = 0; 392 const struct p2p_channels *tmpc = channels ? 393 channels : &p2p->cfg->channels; 394 395 if (tmpc == NULL) 396 return 0; 397 398 for (i = 0; p2p->cfg->pref_chan && i < p2p->cfg->num_pref_chan; i++) { 399 freq = p2p_channel_to_freq(p2p->cfg->pref_chan[i].op_class, 400 p2p->cfg->pref_chan[i].chan); 401 if (p2p_channels_includes_freq(tmpc, freq)) 402 return freq; 403 } 404 return 0; 405 } 406 407 408 void p2p_channels_dump(struct p2p_data *p2p, const char *title, 409 const struct p2p_channels *chan) 410 { 411 char buf[500], *pos, *end; 412 size_t i, j; 413 int ret; 414 415 pos = buf; 416 end = pos + sizeof(buf); 417 418 for (i = 0; i < chan->reg_classes; i++) { 419 const struct p2p_reg_class *c; 420 c = &chan->reg_class[i]; 421 ret = os_snprintf(pos, end - pos, " %u:", c->reg_class); 422 if (ret < 0 || ret >= end - pos) 423 break; 424 pos += ret; 425 426 for (j = 0; j < c->channels; j++) { 427 ret = os_snprintf(pos, end - pos, "%s%u", 428 j == 0 ? "" : ",", 429 c->channel[j]); 430 if (ret < 0 || ret >= end - pos) 431 break; 432 pos += ret; 433 } 434 } 435 *pos = '\0'; 436 437 p2p_dbg(p2p, "%s:%s", title, buf); 438 } 439 440 441 static u8 p2p_channel_pick_random(const u8 *channels, unsigned int num_channels) 442 { 443 unsigned int r; 444 os_get_random((u8 *) &r, sizeof(r)); 445 r %= num_channels; 446 return channels[r]; 447 } 448 449 450 int p2p_channel_select(struct p2p_channels *chans, const int *classes, 451 u8 *op_class, u8 *op_channel) 452 { 453 unsigned int i, j; 454 455 for (j = 0; classes == NULL || classes[j]; j++) { 456 for (i = 0; i < chans->reg_classes; i++) { 457 struct p2p_reg_class *c = &chans->reg_class[i]; 458 459 if (c->channels == 0) 460 continue; 461 462 if (classes == NULL || c->reg_class == classes[j]) { 463 /* 464 * Pick one of the available channels in the 465 * operating class at random. 466 */ 467 *op_class = c->reg_class; 468 *op_channel = p2p_channel_pick_random( 469 c->channel, c->channels); 470 return 0; 471 } 472 } 473 if (classes == NULL) 474 break; 475 } 476 477 return -1; 478 } 479 480 481 int p2p_channel_random_social(struct p2p_channels *chans, u8 *op_class, 482 u8 *op_channel) 483 { 484 u8 chan[3]; 485 unsigned int num_channels = 0; 486 487 /* Try to find available social channels from 2.4 GHz */ 488 if (p2p_channels_includes(chans, 81, 1)) 489 chan[num_channels++] = 1; 490 if (p2p_channels_includes(chans, 81, 6)) 491 chan[num_channels++] = 6; 492 if (p2p_channels_includes(chans, 81, 11)) 493 chan[num_channels++] = 11; 494 495 if (num_channels == 0) 496 return -1; 497 498 *op_class = 81; 499 *op_channel = p2p_channel_pick_random(chan, num_channels); 500 501 return 0; 502 } 503
