p2p_utils.c revision a3dc30964aa24aea2b518246f6812663a1103490
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 */ 25int 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 */ 56int 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 */ 68int 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 >= 5745 && freq <= 5845) { 105 if ((freq - 5000) % 5) 106 return -1; 107 108 *op_class = 125; /* 5 GHz, channels 149..169 */ 109 *channel = (freq - 5000) / 5; 110 return 0; 111 } 112 113 if (freq >= 58320 && freq <= 64800) { 114 if ((freq - 58320) % 2160) 115 return -1; 116 117 *op_class = 180; /* 60 GHz, channels 1..4 */ 118 *channel = (freq - 56160) / 2160; 119 return 0; 120 } 121 122 return -1; 123} 124 125 126static void p2p_reg_class_intersect(const struct p2p_reg_class *a, 127 const struct p2p_reg_class *b, 128 struct p2p_reg_class *res) 129{ 130 size_t i, j; 131 132 res->reg_class = a->reg_class; 133 134 for (i = 0; i < a->channels; i++) { 135 for (j = 0; j < b->channels; j++) { 136 if (a->channel[i] != b->channel[j]) 137 continue; 138 res->channel[res->channels] = a->channel[i]; 139 res->channels++; 140 if (res->channels == P2P_MAX_REG_CLASS_CHANNELS) 141 return; 142 } 143 } 144} 145 146 147/** 148 * p2p_channels_intersect - Intersection of supported channel lists 149 * @a: First set of supported channels 150 * @b: Second set of supported channels 151 * @res: Data structure for returning the intersection of support channels 152 * 153 * This function can be used to find a common set of supported channels. Both 154 * input channels sets are assumed to use the same country code. If different 155 * country codes are used, the regulatory class numbers may not be matched 156 * correctly and results are undefined. 157 */ 158void p2p_channels_intersect(const struct p2p_channels *a, 159 const struct p2p_channels *b, 160 struct p2p_channels *res) 161{ 162 size_t i, j; 163 164 os_memset(res, 0, sizeof(*res)); 165 166 for (i = 0; i < a->reg_classes; i++) { 167 const struct p2p_reg_class *a_reg = &a->reg_class[i]; 168 for (j = 0; j < b->reg_classes; j++) { 169 const struct p2p_reg_class *b_reg = &b->reg_class[j]; 170 if (a_reg->reg_class != b_reg->reg_class) 171 continue; 172 p2p_reg_class_intersect( 173 a_reg, b_reg, 174 &res->reg_class[res->reg_classes]); 175 if (res->reg_class[res->reg_classes].channels) { 176 res->reg_classes++; 177 if (res->reg_classes == P2P_MAX_REG_CLASSES) 178 return; 179 } 180 } 181 } 182} 183 184 185static void p2p_op_class_union(struct p2p_reg_class *cl, 186 const struct p2p_reg_class *b_cl) 187{ 188 size_t i, j; 189 190 for (i = 0; i < b_cl->channels; i++) { 191 for (j = 0; j < cl->channels; j++) { 192 if (b_cl->channel[i] == cl->channel[j]) 193 break; 194 } 195 if (j == cl->channels) { 196 if (cl->channels == P2P_MAX_REG_CLASS_CHANNELS) 197 return; 198 cl->channel[cl->channels++] = b_cl->channel[i]; 199 } 200 } 201} 202 203 204/** 205 * p2p_channels_union_inplace - Inplace union of channel lists 206 * @res: Input data and place for returning union of the channel sets 207 * @b: Second set of channels 208 */ 209void p2p_channels_union_inplace(struct p2p_channels *res, 210 const struct p2p_channels *b) 211{ 212 size_t i, j; 213 214 for (i = 0; i < res->reg_classes; i++) { 215 struct p2p_reg_class *cl = &res->reg_class[i]; 216 for (j = 0; j < b->reg_classes; j++) { 217 const struct p2p_reg_class *b_cl = &b->reg_class[j]; 218 if (cl->reg_class != b_cl->reg_class) 219 continue; 220 p2p_op_class_union(cl, b_cl); 221 } 222 } 223 224 for (j = 0; j < b->reg_classes; j++) { 225 const struct p2p_reg_class *b_cl = &b->reg_class[j]; 226 227 for (i = 0; i < res->reg_classes; i++) { 228 struct p2p_reg_class *cl = &res->reg_class[i]; 229 if (cl->reg_class == b_cl->reg_class) 230 break; 231 } 232 233 if (i == res->reg_classes) { 234 if (res->reg_classes == P2P_MAX_REG_CLASSES) 235 return; 236 os_memcpy(&res->reg_class[res->reg_classes++], 237 b_cl, sizeof(struct p2p_reg_class)); 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 */ 249void p2p_channels_union(const struct p2p_channels *a, 250 const struct p2p_channels *b, 251 struct p2p_channels *res) 252{ 253 os_memcpy(res, a, sizeof(*res)); 254 p2p_channels_union_inplace(res, b); 255} 256 257 258void p2p_channels_remove_freqs(struct p2p_channels *chan, 259 const struct wpa_freq_range_list *list) 260{ 261 size_t o, c; 262 263 if (list == NULL) 264 return; 265 266 o = 0; 267 while (o < chan->reg_classes) { 268 struct p2p_reg_class *op = &chan->reg_class[o]; 269 270 c = 0; 271 while (c < op->channels) { 272 int freq = p2p_channel_to_freq(op->reg_class, 273 op->channel[c]); 274 if (freq > 0 && freq_range_list_includes(list, freq)) { 275 op->channels--; 276 os_memmove(&op->channel[c], 277 &op->channel[c + 1], 278 op->channels - c); 279 } else 280 c++; 281 } 282 283 if (op->channels == 0) { 284 chan->reg_classes--; 285 os_memmove(&chan->reg_class[o], &chan->reg_class[o + 1], 286 (chan->reg_classes - o) * 287 sizeof(struct p2p_reg_class)); 288 } else 289 o++; 290 } 291} 292 293 294/** 295 * p2p_channels_includes - Check whether a channel is included in the list 296 * @channels: List of supported channels 297 * @reg_class: Regulatory class of the channel to search 298 * @channel: Channel number of the channel to search 299 * Returns: 1 if channel was found or 0 if not 300 */ 301int p2p_channels_includes(const struct p2p_channels *channels, u8 reg_class, 302 u8 channel) 303{ 304 size_t i, j; 305 for (i = 0; i < channels->reg_classes; i++) { 306 const struct p2p_reg_class *reg = &channels->reg_class[i]; 307 if (reg->reg_class != reg_class) 308 continue; 309 for (j = 0; j < reg->channels; j++) { 310 if (reg->channel[j] == channel) 311 return 1; 312 } 313 } 314 return 0; 315} 316 317 318int p2p_channels_includes_freq(const struct p2p_channels *channels, 319 unsigned int freq) 320{ 321 size_t i, j; 322 for (i = 0; i < channels->reg_classes; i++) { 323 const struct p2p_reg_class *reg = &channels->reg_class[i]; 324 for (j = 0; j < reg->channels; j++) { 325 if (p2p_channel_to_freq(reg->reg_class, 326 reg->channel[j]) == (int) freq) 327 return 1; 328 } 329 } 330 return 0; 331} 332 333 334int p2p_supported_freq(struct p2p_data *p2p, unsigned int freq) 335{ 336 u8 op_reg_class, op_channel; 337 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0) 338 return 0; 339 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class, 340 op_channel); 341} 342 343 344int p2p_supported_freq_go(struct p2p_data *p2p, unsigned int freq) 345{ 346 u8 op_reg_class, op_channel; 347 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0) 348 return 0; 349 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class, 350 op_channel) && 351 !freq_range_list_includes(&p2p->no_go_freq, freq); 352} 353 354 355int p2p_supported_freq_cli(struct p2p_data *p2p, unsigned int freq) 356{ 357 u8 op_reg_class, op_channel; 358 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0) 359 return 0; 360 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class, 361 op_channel) || 362 p2p_channels_includes(&p2p->cfg->cli_channels, op_reg_class, 363 op_channel); 364} 365 366 367unsigned int p2p_get_pref_freq(struct p2p_data *p2p, 368 const struct p2p_channels *channels) 369{ 370 unsigned int i; 371 int freq = 0; 372 const struct p2p_channels *tmpc = channels ? 373 channels : &p2p->cfg->channels; 374 375 if (tmpc == NULL) 376 return 0; 377 378 for (i = 0; p2p->cfg->pref_chan && i < p2p->cfg->num_pref_chan; i++) { 379 freq = p2p_channel_to_freq(p2p->cfg->pref_chan[i].op_class, 380 p2p->cfg->pref_chan[i].chan); 381 if (p2p_channels_includes_freq(tmpc, freq)) 382 return freq; 383 } 384 return 0; 385} 386 387 388void p2p_channels_dump(struct p2p_data *p2p, const char *title, 389 const struct p2p_channels *chan) 390{ 391 char buf[500], *pos, *end; 392 size_t i, j; 393 int ret; 394 395 pos = buf; 396 end = pos + sizeof(buf); 397 398 for (i = 0; i < chan->reg_classes; i++) { 399 const struct p2p_reg_class *c; 400 c = &chan->reg_class[i]; 401 ret = os_snprintf(pos, end - pos, " %u:", c->reg_class); 402 if (os_snprintf_error(end - pos, ret)) 403 break; 404 pos += ret; 405 406 for (j = 0; j < c->channels; j++) { 407 ret = os_snprintf(pos, end - pos, "%s%u", 408 j == 0 ? "" : ",", 409 c->channel[j]); 410 if (os_snprintf_error(end - pos, ret)) 411 break; 412 pos += ret; 413 } 414 } 415 *pos = '\0'; 416 417 p2p_dbg(p2p, "%s:%s", title, buf); 418} 419 420 421static u8 p2p_channel_pick_random(const u8 *channels, unsigned int num_channels) 422{ 423 unsigned int r; 424 if (os_get_random((u8 *) &r, sizeof(r)) < 0) 425 r = 0; 426 r %= num_channels; 427 return channels[r]; 428} 429 430 431int p2p_channel_select(struct p2p_channels *chans, const int *classes, 432 u8 *op_class, u8 *op_channel) 433{ 434 unsigned int i, j; 435 436 for (j = 0; classes == NULL || classes[j]; j++) { 437 for (i = 0; i < chans->reg_classes; i++) { 438 struct p2p_reg_class *c = &chans->reg_class[i]; 439 440 if (c->channels == 0) 441 continue; 442 443 if (classes == NULL || c->reg_class == classes[j]) { 444 /* 445 * Pick one of the available channels in the 446 * operating class at random. 447 */ 448 *op_class = c->reg_class; 449 *op_channel = p2p_channel_pick_random( 450 c->channel, c->channels); 451 return 0; 452 } 453 } 454 if (classes == NULL) 455 break; 456 } 457 458 return -1; 459} 460 461 462int p2p_channel_random_social(struct p2p_channels *chans, u8 *op_class, 463 u8 *op_channel) 464{ 465 u8 chan[4]; 466 unsigned int num_channels = 0; 467 468 /* Try to find available social channels from 2.4 GHz */ 469 if (p2p_channels_includes(chans, 81, 1)) 470 chan[num_channels++] = 1; 471 if (p2p_channels_includes(chans, 81, 6)) 472 chan[num_channels++] = 6; 473 if (p2p_channels_includes(chans, 81, 11)) 474 chan[num_channels++] = 11; 475 476 /* Try to find available social channels from 60 GHz */ 477 if (p2p_channels_includes(chans, 180, 2)) 478 chan[num_channels++] = 2; 479 480 if (num_channels == 0) 481 return -1; 482 483 *op_channel = p2p_channel_pick_random(chan, num_channels); 484 if (*op_channel == 2) 485 *op_class = 180; 486 else 487 *op_class = 81; 488 489 return 0; 490} 491 492 493int p2p_channels_to_freqs(const struct p2p_channels *channels, int *freq_list, 494 unsigned int max_len) 495{ 496 unsigned int i, idx; 497 498 if (!channels || max_len == 0) 499 return 0; 500 501 for (i = 0, idx = 0; i < channels->reg_classes; i++) { 502 const struct p2p_reg_class *c = &channels->reg_class[i]; 503 unsigned int j; 504 505 if (idx + 1 == max_len) 506 break; 507 for (j = 0; j < c->channels; j++) { 508 int freq; 509 if (idx + 1 == max_len) 510 break; 511 freq = p2p_channel_to_freq(c->reg_class, 512 c->channel[j]); 513 if (freq < 0) 514 continue; 515 freq_list[idx++] = freq; 516 } 517 } 518 519 freq_list[idx] = 0; 520 521 return idx; 522} 523