p2p_utils.c revision 68d0e3ed07847339aedfac8e02f50db68c702e52
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 */ 24int 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 */ 55int 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 } 102 return -1; 103} 104 105 106/** 107 * p2p_freq_to_channel - Convert frequency into channel info 108 * @op_class: Buffer for returning operating class 109 * @channel: Buffer for returning channel number 110 * Returns: 0 on success, -1 if the specified frequency is unknown 111 */ 112int p2p_freq_to_channel(unsigned int freq, u8 *op_class, u8 *channel) 113{ 114 /* TODO: more operating classes */ 115 if (freq >= 2412 && freq <= 2472) { 116 if ((freq - 2407) % 5) 117 return -1; 118 119 *op_class = 81; /* 2.407 GHz, channels 1..13 */ 120 *channel = (freq - 2407) / 5; 121 return 0; 122 } 123 124 if (freq == 2484) { 125 *op_class = 82; /* channel 14 */ 126 *channel = 14; 127 return 0; 128 } 129 130 if (freq >= 5180 && freq <= 5240) { 131 if ((freq - 5000) % 5) 132 return -1; 133 134 *op_class = 115; /* 5 GHz, channels 36..48 */ 135 *channel = (freq - 5000) / 5; 136 return 0; 137 } 138 139 if (freq >= 5745 && freq <= 5805) { 140 if ((freq - 5000) % 5) 141 return -1; 142 143 *op_class = 124; /* 5 GHz, channels 149..161 */ 144 *channel = (freq - 5000) / 5; 145 return 0; 146 } 147 148 return -1; 149} 150 151 152static void p2p_reg_class_intersect(const struct p2p_reg_class *a, 153 const struct p2p_reg_class *b, 154 struct p2p_reg_class *res) 155{ 156 size_t i, j; 157 158 res->reg_class = a->reg_class; 159 160 for (i = 0; i < a->channels; i++) { 161 for (j = 0; j < b->channels; j++) { 162 if (a->channel[i] != b->channel[j]) 163 continue; 164 res->channel[res->channels] = a->channel[i]; 165 res->channels++; 166 if (res->channels == P2P_MAX_REG_CLASS_CHANNELS) 167 return; 168 } 169 } 170} 171 172 173/** 174 * p2p_channels_intersect - Intersection of supported channel lists 175 * @a: First set of supported channels 176 * @b: Second set of supported channels 177 * @res: Data structure for returning the intersection of support channels 178 * 179 * This function can be used to find a common set of supported channels. Both 180 * input channels sets are assumed to use the same country code. If different 181 * country codes are used, the regulatory class numbers may not be matched 182 * correctly and results are undefined. 183 */ 184void p2p_channels_intersect(const struct p2p_channels *a, 185 const struct p2p_channels *b, 186 struct p2p_channels *res) 187{ 188 size_t i, j; 189 190 os_memset(res, 0, sizeof(*res)); 191 192 for (i = 0; i < a->reg_classes; i++) { 193 const struct p2p_reg_class *a_reg = &a->reg_class[i]; 194 for (j = 0; j < b->reg_classes; j++) { 195 const struct p2p_reg_class *b_reg = &b->reg_class[j]; 196 if (a_reg->reg_class != b_reg->reg_class) 197 continue; 198 p2p_reg_class_intersect( 199 a_reg, b_reg, 200 &res->reg_class[res->reg_classes]); 201 if (res->reg_class[res->reg_classes].channels) { 202 res->reg_classes++; 203 if (res->reg_classes == P2P_MAX_REG_CLASSES) 204 return; 205 } 206 } 207 } 208} 209 210 211static void p2p_op_class_union(struct p2p_reg_class *cl, 212 const struct p2p_reg_class *b_cl) 213{ 214 size_t i, j; 215 216 for (i = 0; i < b_cl->channels; i++) { 217 for (j = 0; j < cl->channels; j++) { 218 if (b_cl->channel[i] == cl->channel[j]) 219 break; 220 } 221 if (j == cl->channels) { 222 if (cl->channels == P2P_MAX_REG_CLASS_CHANNELS) 223 return; 224 cl->channel[cl->channels++] = b_cl->channel[i]; 225 } 226 } 227} 228 229 230/** 231 * p2p_channels_union - Union of channel lists 232 * @a: First set of channels 233 * @b: Second set of channels 234 * @res: Data structure for returning the union of channels 235 */ 236void p2p_channels_union(const struct p2p_channels *a, 237 const struct p2p_channels *b, 238 struct p2p_channels *res) 239{ 240 size_t i, j; 241 242 if (a != res) 243 os_memcpy(res, a, sizeof(*res)); 244 245 for (i = 0; i < res->reg_classes; i++) { 246 struct p2p_reg_class *cl = &res->reg_class[i]; 247 for (j = 0; j < b->reg_classes; j++) { 248 const struct p2p_reg_class *b_cl = &b->reg_class[j]; 249 if (cl->reg_class != b_cl->reg_class) 250 continue; 251 p2p_op_class_union(cl, b_cl); 252 } 253 } 254 255 for (j = 0; j < b->reg_classes; j++) { 256 const struct p2p_reg_class *b_cl = &b->reg_class[j]; 257 258 for (i = 0; i < res->reg_classes; i++) { 259 struct p2p_reg_class *cl = &res->reg_class[i]; 260 if (cl->reg_class == b_cl->reg_class) 261 break; 262 } 263 264 if (i == res->reg_classes) { 265 if (res->reg_classes == P2P_MAX_REG_CLASSES) 266 return; 267 os_memcpy(&res->reg_class[res->reg_classes++], 268 b_cl, sizeof(struct p2p_reg_class)); 269 } 270 } 271} 272 273 274void p2p_channels_remove_freqs(struct p2p_channels *chan, 275 const struct wpa_freq_range_list *list) 276{ 277 size_t o, c; 278 279 if (list == NULL) 280 return; 281 282 o = 0; 283 while (o < chan->reg_classes) { 284 struct p2p_reg_class *op = &chan->reg_class[o]; 285 286 c = 0; 287 while (c < op->channels) { 288 int freq = p2p_channel_to_freq(op->reg_class, 289 op->channel[c]); 290 if (freq > 0 && freq_range_list_includes(list, freq)) { 291 op->channels--; 292 os_memmove(&op->channel[c], 293 &op->channel[c + 1], 294 op->channels - c); 295 } else 296 c++; 297 } 298 299 if (op->channels == 0) { 300 chan->reg_classes--; 301 os_memmove(&chan->reg_class[o], &chan->reg_class[o + 1], 302 (chan->reg_classes - o) * 303 sizeof(struct p2p_reg_class)); 304 } else 305 o++; 306 } 307} 308 309 310/** 311 * p2p_channels_includes - Check whether a channel is included in the list 312 * @channels: List of supported channels 313 * @reg_class: Regulatory class of the channel to search 314 * @channel: Channel number of the channel to search 315 * Returns: 1 if channel was found or 0 if not 316 */ 317int p2p_channels_includes(const struct p2p_channels *channels, u8 reg_class, 318 u8 channel) 319{ 320 size_t i, j; 321 for (i = 0; i < channels->reg_classes; i++) { 322 const struct p2p_reg_class *reg = &channels->reg_class[i]; 323 if (reg->reg_class != reg_class) 324 continue; 325 for (j = 0; j < reg->channels; j++) { 326 if (reg->channel[j] == channel) 327 return 1; 328 } 329 } 330 return 0; 331} 332 333 334int p2p_channels_includes_freq(const struct p2p_channels *channels, 335 unsigned int freq) 336{ 337 size_t i, j; 338 for (i = 0; i < channels->reg_classes; i++) { 339 const struct p2p_reg_class *reg = &channels->reg_class[i]; 340 for (j = 0; j < reg->channels; j++) { 341 if (p2p_channel_to_freq(reg->reg_class, 342 reg->channel[j]) == (int) freq) 343 return 1; 344 } 345 } 346 return 0; 347} 348 349 350#ifdef ANDROID_P2P 351static int p2p_block_op_freq(unsigned int freq) 352{ 353 return (freq >= 5170 && freq < 5745); 354} 355 356 357size_t p2p_copy_reg_class(struct p2p_reg_class *dc, struct p2p_reg_class *sc) 358{ 359 unsigned int i; 360 361 dc->reg_class = sc->reg_class; 362 dc->channels = 0; 363 for (i=0; i < sc->channels; i++) { 364 if (!p2p_block_op_freq(p2p_channel_to_freq(sc->reg_class, 365 sc->channel[i]))) { 366 dc->channel[dc->channels] = sc->channel[i]; 367 dc->channels++; 368 } 369 } 370 return dc->channels; 371} 372#endif 373 374 375int p2p_supported_freq(struct p2p_data *p2p, unsigned int freq) 376{ 377 u8 op_reg_class, op_channel; 378 379#ifdef ANDROID_P2P 380 if (p2p_block_op_freq(freq)) 381 return 0; 382#endif 383 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0) 384 return 0; 385 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class, 386 op_channel); 387} 388 389 390int p2p_supported_freq_go(struct p2p_data *p2p, unsigned int freq) 391{ 392 u8 op_reg_class, op_channel; 393 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0) 394 return 0; 395 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class, 396 op_channel) && 397 !freq_range_list_includes(&p2p->no_go_freq, freq); 398} 399 400 401int p2p_supported_freq_cli(struct p2p_data *p2p, unsigned int freq) 402{ 403 u8 op_reg_class, op_channel; 404 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0) 405 return 0; 406 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class, 407 op_channel) || 408 p2p_channels_includes(&p2p->cfg->cli_channels, op_reg_class, 409 op_channel); 410} 411 412 413unsigned int p2p_get_pref_freq(struct p2p_data *p2p, 414 const struct p2p_channels *channels) 415{ 416 unsigned int i; 417 int freq = 0; 418 419 if (channels == NULL) { 420 if (p2p->cfg->num_pref_chan) { 421 freq = p2p_channel_to_freq( 422 p2p->cfg->pref_chan[0].op_class, 423 p2p->cfg->pref_chan[0].chan); 424 if (freq < 0) 425 freq = 0; 426 } 427 return freq; 428 } 429 430 for (i = 0; p2p->cfg->pref_chan && i < p2p->cfg->num_pref_chan; i++) { 431 freq = p2p_channel_to_freq(p2p->cfg->pref_chan[i].op_class, 432 p2p->cfg->pref_chan[i].chan); 433 if (p2p_channels_includes_freq(channels, freq)) 434 return freq; 435 } 436 437 return 0; 438} 439 440 441void p2p_channels_dump(struct p2p_data *p2p, const char *title, 442 const struct p2p_channels *chan) 443{ 444 char buf[500], *pos, *end; 445 size_t i, j; 446 int ret; 447 448 pos = buf; 449 end = pos + sizeof(buf); 450 451 for (i = 0; i < chan->reg_classes; i++) { 452 const struct p2p_reg_class *c; 453 c = &chan->reg_class[i]; 454 ret = os_snprintf(pos, end - pos, " %u:", c->reg_class); 455 if (ret < 0 || ret >= end - pos) 456 break; 457 pos += ret; 458 459 for (j = 0; j < c->channels; j++) { 460 ret = os_snprintf(pos, end - pos, "%s%u", 461 j == 0 ? "" : ",", 462 c->channel[j]); 463 if (ret < 0 || ret >= end - pos) 464 break; 465 pos += ret; 466 } 467 } 468 *pos = '\0'; 469 470 p2p_dbg(p2p, "%s:%s", title, buf); 471} 472