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/defs.h"
13 #include "common/ieee802_11_common.h"
14 #include "p2p_i.h"
15
16
17 /**
18 * p2p_random - Generate random string for SSID and passphrase
19 * @buf: Buffer for returning the result
20 * @len: Number of octets to write to the buffer
21 * Returns: 0 on success, -1 on failure
22 *
23 * This function generates a random string using the following character set:
24 * 'A'-'Z', 'a'-'z', '0'-'9'.
25 */
p2p_random(char * buf,size_t len)26 int p2p_random(char *buf, size_t len)
27 {
28 u8 val;
29 size_t i;
30 u8 letters = 'Z' - 'A' + 1;
31 u8 numbers = 10;
32
33 if (os_get_random((unsigned char *) buf, len))
34 return -1;
35 /* Character set: 'A'-'Z', 'a'-'z', '0'-'9' */
36 for (i = 0; i < len; i++) {
37 val = buf[i];
38 val %= 2 * letters + numbers;
39 if (val < letters)
40 buf[i] = 'A' + val;
41 else if (val < 2 * letters)
42 buf[i] = 'a' + (val - letters);
43 else
44 buf[i] = '0' + (val - 2 * letters);
45 }
46
47 return 0;
48 }
49
50
51 /**
52 * p2p_channel_to_freq - Convert channel info to frequency
53 * @op_class: Operating class
54 * @channel: Channel number
55 * Returns: Frequency in MHz or -1 if the specified channel is unknown
56 */
p2p_channel_to_freq(int op_class,int channel)57 int p2p_channel_to_freq(int op_class, int channel)
58 {
59 return ieee80211_chan_to_freq(NULL, op_class, channel);
60 }
61
62
63 /**
64 * p2p_freq_to_channel - Convert frequency into channel info
65 * @op_class: Buffer for returning operating class
66 * @channel: Buffer for returning channel number
67 * Returns: 0 on success, -1 if the specified frequency is unknown
68 */
p2p_freq_to_channel(unsigned int freq,u8 * op_class,u8 * channel)69 int p2p_freq_to_channel(unsigned int freq, u8 *op_class, u8 *channel)
70 {
71 if (ieee80211_freq_to_channel_ext(freq, 0, 0, op_class, channel) ==
72 NUM_HOSTAPD_MODES)
73 return -1;
74
75 return 0;
76 }
77
78
p2p_reg_class_intersect(const struct p2p_reg_class * a,const struct p2p_reg_class * b,struct p2p_reg_class * res)79 static void p2p_reg_class_intersect(const struct p2p_reg_class *a,
80 const struct p2p_reg_class *b,
81 struct p2p_reg_class *res)
82 {
83 size_t i, j;
84
85 res->reg_class = a->reg_class;
86
87 for (i = 0; i < a->channels; i++) {
88 for (j = 0; j < b->channels; j++) {
89 if (a->channel[i] != b->channel[j])
90 continue;
91 res->channel[res->channels] = a->channel[i];
92 res->channels++;
93 if (res->channels == P2P_MAX_REG_CLASS_CHANNELS)
94 return;
95 }
96 }
97 }
98
99
100 /**
101 * p2p_channels_intersect - Intersection of supported channel lists
102 * @a: First set of supported channels
103 * @b: Second set of supported channels
104 * @res: Data structure for returning the intersection of support channels
105 *
106 * This function can be used to find a common set of supported channels. Both
107 * input channels sets are assumed to use the same country code. If different
108 * country codes are used, the regulatory class numbers may not be matched
109 * correctly and results are undefined.
110 */
p2p_channels_intersect(const struct p2p_channels * a,const struct p2p_channels * b,struct p2p_channels * res)111 void p2p_channels_intersect(const struct p2p_channels *a,
112 const struct p2p_channels *b,
113 struct p2p_channels *res)
114 {
115 size_t i, j;
116
117 os_memset(res, 0, sizeof(*res));
118
119 for (i = 0; i < a->reg_classes; i++) {
120 const struct p2p_reg_class *a_reg = &a->reg_class[i];
121 for (j = 0; j < b->reg_classes; j++) {
122 const struct p2p_reg_class *b_reg = &b->reg_class[j];
123 if (a_reg->reg_class != b_reg->reg_class)
124 continue;
125 p2p_reg_class_intersect(
126 a_reg, b_reg,
127 &res->reg_class[res->reg_classes]);
128 if (res->reg_class[res->reg_classes].channels) {
129 res->reg_classes++;
130 if (res->reg_classes == P2P_MAX_REG_CLASSES)
131 return;
132 }
133 }
134 }
135 }
136
137
p2p_op_class_union(struct p2p_reg_class * cl,const struct p2p_reg_class * b_cl)138 static void p2p_op_class_union(struct p2p_reg_class *cl,
139 const struct p2p_reg_class *b_cl)
140 {
141 size_t i, j;
142
143 for (i = 0; i < b_cl->channels; i++) {
144 for (j = 0; j < cl->channels; j++) {
145 if (b_cl->channel[i] == cl->channel[j])
146 break;
147 }
148 if (j == cl->channels) {
149 if (cl->channels == P2P_MAX_REG_CLASS_CHANNELS)
150 return;
151 cl->channel[cl->channels++] = b_cl->channel[i];
152 }
153 }
154 }
155
156
157 /**
158 * p2p_channels_union_inplace - Inplace union of channel lists
159 * @res: Input data and place for returning union of the channel sets
160 * @b: Second set of channels
161 */
p2p_channels_union_inplace(struct p2p_channels * res,const struct p2p_channels * b)162 void p2p_channels_union_inplace(struct p2p_channels *res,
163 const struct p2p_channels *b)
164 {
165 size_t i, j;
166
167 for (i = 0; i < res->reg_classes; i++) {
168 struct p2p_reg_class *cl = &res->reg_class[i];
169 for (j = 0; j < b->reg_classes; j++) {
170 const struct p2p_reg_class *b_cl = &b->reg_class[j];
171 if (cl->reg_class != b_cl->reg_class)
172 continue;
173 p2p_op_class_union(cl, b_cl);
174 }
175 }
176
177 for (j = 0; j < b->reg_classes; j++) {
178 const struct p2p_reg_class *b_cl = &b->reg_class[j];
179
180 for (i = 0; i < res->reg_classes; i++) {
181 struct p2p_reg_class *cl = &res->reg_class[i];
182 if (cl->reg_class == b_cl->reg_class)
183 break;
184 }
185
186 if (i == res->reg_classes) {
187 if (res->reg_classes == P2P_MAX_REG_CLASSES)
188 return;
189 os_memcpy(&res->reg_class[res->reg_classes++],
190 b_cl, sizeof(struct p2p_reg_class));
191 }
192 }
193 }
194
195
196 /**
197 * p2p_channels_union - Union of channel lists
198 * @a: First set of channels
199 * @b: Second set of channels
200 * @res: Data structure for returning the union of channels
201 */
p2p_channels_union(const struct p2p_channels * a,const struct p2p_channels * b,struct p2p_channels * res)202 void p2p_channels_union(const struct p2p_channels *a,
203 const struct p2p_channels *b,
204 struct p2p_channels *res)
205 {
206 os_memcpy(res, a, sizeof(*res));
207 p2p_channels_union_inplace(res, b);
208 }
209
210
p2p_channels_remove_freqs(struct p2p_channels * chan,const struct wpa_freq_range_list * list)211 void p2p_channels_remove_freqs(struct p2p_channels *chan,
212 const struct wpa_freq_range_list *list)
213 {
214 size_t o, c;
215
216 if (list == NULL)
217 return;
218
219 o = 0;
220 while (o < chan->reg_classes) {
221 struct p2p_reg_class *op = &chan->reg_class[o];
222
223 c = 0;
224 while (c < op->channels) {
225 int freq = p2p_channel_to_freq(op->reg_class,
226 op->channel[c]);
227 if (freq > 0 && freq_range_list_includes(list, freq)) {
228 op->channels--;
229 os_memmove(&op->channel[c],
230 &op->channel[c + 1],
231 op->channels - c);
232 } else
233 c++;
234 }
235
236 if (op->channels == 0) {
237 chan->reg_classes--;
238 os_memmove(&chan->reg_class[o], &chan->reg_class[o + 1],
239 (chan->reg_classes - o) *
240 sizeof(struct p2p_reg_class));
241 } else
242 o++;
243 }
244 }
245
246
247 /**
248 * p2p_channels_includes - Check whether a channel is included in the list
249 * @channels: List of supported channels
250 * @reg_class: Regulatory class of the channel to search
251 * @channel: Channel number of the channel to search
252 * Returns: 1 if channel was found or 0 if not
253 */
p2p_channels_includes(const struct p2p_channels * channels,u8 reg_class,u8 channel)254 int p2p_channels_includes(const struct p2p_channels *channels, u8 reg_class,
255 u8 channel)
256 {
257 size_t i, j;
258 for (i = 0; i < channels->reg_classes; i++) {
259 const struct p2p_reg_class *reg = &channels->reg_class[i];
260 if (reg->reg_class != reg_class)
261 continue;
262 for (j = 0; j < reg->channels; j++) {
263 if (reg->channel[j] == channel)
264 return 1;
265 }
266 }
267 return 0;
268 }
269
270
p2p_channels_includes_freq(const struct p2p_channels * channels,unsigned int freq)271 int p2p_channels_includes_freq(const struct p2p_channels *channels,
272 unsigned int freq)
273 {
274 size_t i, j;
275 for (i = 0; i < channels->reg_classes; i++) {
276 const struct p2p_reg_class *reg = &channels->reg_class[i];
277 for (j = 0; j < reg->channels; j++) {
278 if (p2p_channel_to_freq(reg->reg_class,
279 reg->channel[j]) == (int) freq)
280 return 1;
281 }
282 }
283 return 0;
284 }
285
286
p2p_supported_freq(struct p2p_data * p2p,unsigned int freq)287 int p2p_supported_freq(struct p2p_data *p2p, unsigned int freq)
288 {
289 u8 op_reg_class, op_channel;
290 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0)
291 return 0;
292 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class,
293 op_channel);
294 }
295
296
p2p_supported_freq_go(struct p2p_data * p2p,unsigned int freq)297 int p2p_supported_freq_go(struct p2p_data *p2p, unsigned int freq)
298 {
299 u8 op_reg_class, op_channel;
300 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0)
301 return 0;
302 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class,
303 op_channel) &&
304 !freq_range_list_includes(&p2p->no_go_freq, freq);
305 }
306
307
p2p_supported_freq_cli(struct p2p_data * p2p,unsigned int freq)308 int p2p_supported_freq_cli(struct p2p_data *p2p, unsigned int freq)
309 {
310 u8 op_reg_class, op_channel;
311 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0)
312 return 0;
313 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class,
314 op_channel) ||
315 p2p_channels_includes(&p2p->cfg->cli_channels, op_reg_class,
316 op_channel);
317 }
318
319
p2p_get_pref_freq(struct p2p_data * p2p,const struct p2p_channels * channels)320 unsigned int p2p_get_pref_freq(struct p2p_data *p2p,
321 const struct p2p_channels *channels)
322 {
323 unsigned int i;
324 int freq = 0;
325 const struct p2p_channels *tmpc = channels ?
326 channels : &p2p->cfg->channels;
327
328 if (tmpc == NULL)
329 return 0;
330
331 for (i = 0; p2p->cfg->pref_chan && i < p2p->cfg->num_pref_chan; i++) {
332 freq = p2p_channel_to_freq(p2p->cfg->pref_chan[i].op_class,
333 p2p->cfg->pref_chan[i].chan);
334 if (p2p_channels_includes_freq(tmpc, freq))
335 return freq;
336 }
337 return 0;
338 }
339
340
p2p_channels_dump(struct p2p_data * p2p,const char * title,const struct p2p_channels * chan)341 void p2p_channels_dump(struct p2p_data *p2p, const char *title,
342 const struct p2p_channels *chan)
343 {
344 char buf[500], *pos, *end;
345 size_t i, j;
346 int ret;
347
348 pos = buf;
349 end = pos + sizeof(buf);
350
351 for (i = 0; i < chan->reg_classes; i++) {
352 const struct p2p_reg_class *c;
353 c = &chan->reg_class[i];
354 ret = os_snprintf(pos, end - pos, " %u:", c->reg_class);
355 if (os_snprintf_error(end - pos, ret))
356 break;
357 pos += ret;
358
359 for (j = 0; j < c->channels; j++) {
360 ret = os_snprintf(pos, end - pos, "%s%u",
361 j == 0 ? "" : ",",
362 c->channel[j]);
363 if (os_snprintf_error(end - pos, ret))
364 break;
365 pos += ret;
366 }
367 }
368 *pos = '\0';
369
370 p2p_dbg(p2p, "%s:%s", title, buf);
371 }
372
373
p2p_channel_pick_random(const u8 * channels,unsigned int num_channels)374 static u8 p2p_channel_pick_random(const u8 *channels, unsigned int num_channels)
375 {
376 unsigned int r;
377 if (os_get_random((u8 *) &r, sizeof(r)) < 0)
378 r = 0;
379 r %= num_channels;
380 return channels[r];
381 }
382
383
p2p_channel_select(struct p2p_channels * chans,const int * classes,u8 * op_class,u8 * op_channel)384 int p2p_channel_select(struct p2p_channels *chans, const int *classes,
385 u8 *op_class, u8 *op_channel)
386 {
387 unsigned int i, j;
388
389 for (j = 0; classes == NULL || classes[j]; j++) {
390 for (i = 0; i < chans->reg_classes; i++) {
391 struct p2p_reg_class *c = &chans->reg_class[i];
392
393 if (c->channels == 0)
394 continue;
395
396 if (classes == NULL || c->reg_class == classes[j]) {
397 /*
398 * Pick one of the available channels in the
399 * operating class at random.
400 */
401 *op_class = c->reg_class;
402 *op_channel = p2p_channel_pick_random(
403 c->channel, c->channels);
404 return 0;
405 }
406 }
407 if (classes == NULL)
408 break;
409 }
410
411 return -1;
412 }
413
414
p2p_channel_random_social(struct p2p_channels * chans,u8 * op_class,u8 * op_channel,struct wpa_freq_range_list * avoid_list,struct wpa_freq_range_list * disallow_list)415 int p2p_channel_random_social(struct p2p_channels *chans, u8 *op_class,
416 u8 *op_channel,
417 struct wpa_freq_range_list *avoid_list,
418 struct wpa_freq_range_list *disallow_list)
419 {
420 u8 chan[4];
421 unsigned int num_channels = 0;
422
423 /* Try to find available social channels from 2.4 GHz.
424 * If the avoid_list includes any of the 2.4 GHz social channels, that
425 * channel is not allowed by p2p_channels_includes() rules. However, it
426 * is assumed to allow minimal traffic for P2P negotiation, so allow it
427 * here for social channel selection unless explicitly disallowed in the
428 * disallow_list. */
429 if (p2p_channels_includes(chans, 81, 1) ||
430 (freq_range_list_includes(avoid_list, 2412) &&
431 !freq_range_list_includes(disallow_list, 2412)))
432 chan[num_channels++] = 1;
433 if (p2p_channels_includes(chans, 81, 6) ||
434 (freq_range_list_includes(avoid_list, 2437) &&
435 !freq_range_list_includes(disallow_list, 2437)))
436 chan[num_channels++] = 6;
437 if (p2p_channels_includes(chans, 81, 11) ||
438 (freq_range_list_includes(avoid_list, 2462) &&
439 !freq_range_list_includes(disallow_list, 2462)))
440 chan[num_channels++] = 11;
441
442 /* Try to find available social channels from 60 GHz */
443 if (p2p_channels_includes(chans, 180, 2))
444 chan[num_channels++] = 2;
445
446 if (num_channels == 0)
447 return -1;
448
449 *op_channel = p2p_channel_pick_random(chan, num_channels);
450 if (*op_channel == 2)
451 *op_class = 180;
452 else
453 *op_class = 81;
454
455 return 0;
456 }
457
458
p2p_channels_to_freqs(const struct p2p_channels * channels,int * freq_list,unsigned int max_len)459 int p2p_channels_to_freqs(const struct p2p_channels *channels, int *freq_list,
460 unsigned int max_len)
461 {
462 unsigned int i, idx;
463
464 if (!channels || max_len == 0)
465 return 0;
466
467 for (i = 0, idx = 0; i < channels->reg_classes; i++) {
468 const struct p2p_reg_class *c = &channels->reg_class[i];
469 unsigned int j;
470
471 if (idx + 1 == max_len)
472 break;
473 for (j = 0; j < c->channels; j++) {
474 int freq;
475 unsigned int k;
476
477 if (idx + 1 == max_len)
478 break;
479 freq = p2p_channel_to_freq(c->reg_class,
480 c->channel[j]);
481 if (freq < 0)
482 continue;
483
484 for (k = 0; k < idx; k++) {
485 if (freq_list[k] == freq)
486 break;
487 }
488
489 if (k < idx)
490 continue;
491 freq_list[idx++] = freq;
492 }
493 }
494
495 freq_list[idx] = 0;
496
497 return idx;
498 }
499
500
p2p_copy_channels(struct p2p_channels * dst,const struct p2p_channels * src,bool allow_6ghz)501 void p2p_copy_channels(struct p2p_channels *dst,
502 const struct p2p_channels *src, bool allow_6ghz)
503 {
504 size_t i, j;
505
506 if (allow_6ghz) {
507 os_memcpy(dst, src, sizeof(struct p2p_channels));
508 return;
509 }
510
511 for (i = 0, j = 0; i < src->reg_classes; i++) {
512 if (is_6ghz_op_class(src->reg_class[i].reg_class))
513 continue;
514 os_memcpy(&dst->reg_class[j], &src->reg_class[i],
515 sizeof(struct p2p_reg_class));
516 j++;
517 }
518 dst->reg_classes = j;
519 }
520
521
p2p_remove_6ghz_channels(struct weighted_pcl * pref_freq_list,int size)522 int p2p_remove_6ghz_channels(struct weighted_pcl *pref_freq_list, int size)
523 {
524 int i;
525
526 for (i = 0; i < size; i++) {
527 if (is_6ghz_freq(pref_freq_list[i].freq)) {
528 wpa_printf(MSG_DEBUG, "P2P: Remove 6 GHz channel %d",
529 pref_freq_list[i].freq);
530 size--;
531 os_memmove(&pref_freq_list[i], &pref_freq_list[i + 1],
532 (size - i) * sizeof(pref_freq_list[0]));
533 i--;
534 }
535 }
536 return i;
537 }
538
539
540 /**
541 * p2p_pref_freq_allowed - Based on the flags set, check if the preferred
542 * frequency is allowed
543 * @freq_list: Weighted preferred channel list
544 * @go: Whether the local device is the group owner
545 * Returns: Whether the preferred frequency is allowed
546 */
p2p_pref_freq_allowed(const struct weighted_pcl * freq_list,bool go)547 bool p2p_pref_freq_allowed(const struct weighted_pcl *freq_list, bool go)
548 {
549 if (freq_list->flag & WEIGHTED_PCL_EXCLUDE)
550 return false;
551 if (!(freq_list->flag & WEIGHTED_PCL_CLI) && !go)
552 return false;
553 if (!(freq_list->flag & WEIGHTED_PCL_GO) && go)
554 return false;
555 return true;
556 }
557
558
p2p_check_pref_channel(int channel,u8 op_class,const struct weighted_pcl * freq_list,unsigned int num_channels,bool go)559 static int p2p_check_pref_channel(int channel, u8 op_class,
560 const struct weighted_pcl *freq_list,
561 unsigned int num_channels, bool go)
562 {
563 unsigned int i;
564
565 /* If the channel is present in the preferred channel list, check if it
566 * has appropriate flags for the role.
567 */
568 for (i = 0; i < num_channels; i++) {
569 if (p2p_channel_to_freq(op_class, channel) !=
570 (int) freq_list[i].freq)
571 continue;
572 if (!p2p_pref_freq_allowed(&freq_list[i], go))
573 return -1;
574 break;
575 }
576
577 return 0;
578 }
579
580
p2p_pref_channel_filter(const struct p2p_channels * p2p_chan,const struct weighted_pcl * freq_list,unsigned int num_channels,struct p2p_channels * res,bool go)581 void p2p_pref_channel_filter(const struct p2p_channels *p2p_chan,
582 const struct weighted_pcl *freq_list,
583 unsigned int num_channels,
584 struct p2p_channels *res, bool go)
585 {
586 size_t i, j;
587
588 os_memset(res, 0, sizeof(*res));
589
590 for (i = 0; i < p2p_chan->reg_classes; i++) {
591 const struct p2p_reg_class *reg = &p2p_chan->reg_class[i];
592 struct p2p_reg_class *res_reg = &res->reg_class[i];
593
594 if (num_channels > 0) {
595 for (j = 0; j < reg->channels; j++) {
596 if (p2p_check_pref_channel(reg->channel[j],
597 reg->reg_class,
598 freq_list,
599 num_channels,
600 go) < 0)
601 continue;
602
603 res_reg->channel[res_reg->channels++] =
604 reg->channel[j];
605 }
606 }
607
608 if (res_reg->channels == 0)
609 continue;
610 res->reg_classes++;
611 res_reg->reg_class = reg->reg_class;
612 }
613 }
614