ieee802_11_common.c revision fb79edc9df1f20461e90e478363d207348213d35 
1/*
2 * IEEE 802.11 Common routines
3 * Copyright (c) 2002-2013, Jouni Malinen <j@w1.fi>
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 "defs.h"
13#include "ieee802_11_defs.h"
14#include "ieee802_11_common.h"
15
16
17static int ieee802_11_parse_vendor_specific(const u8 *pos, size_t elen,
18					    struct ieee802_11_elems *elems,
19					    int show_errors)
20{
21	unsigned int oui;
22
23	/* first 3 bytes in vendor specific information element are the IEEE
24	 * OUI of the vendor. The following byte is used a vendor specific
25	 * sub-type. */
26	if (elen < 4) {
27		if (show_errors) {
28			wpa_printf(MSG_MSGDUMP, "short vendor specific "
29				   "information element ignored (len=%lu)",
30				   (unsigned long) elen);
31		}
32		return -1;
33	}
34
35	oui = WPA_GET_BE24(pos);
36	switch (oui) {
37	case OUI_MICROSOFT:
38		/* Microsoft/Wi-Fi information elements are further typed and
39		 * subtyped */
40		switch (pos[3]) {
41		case 1:
42			/* Microsoft OUI (00:50:F2) with OUI Type 1:
43			 * real WPA information element */
44			elems->wpa_ie = pos;
45			elems->wpa_ie_len = elen;
46			break;
47		case WMM_OUI_TYPE:
48			/* WMM information element */
49			if (elen < 5) {
50				wpa_printf(MSG_MSGDUMP, "short WMM "
51					   "information element ignored "
52					   "(len=%lu)",
53					   (unsigned long) elen);
54				return -1;
55			}
56			switch (pos[4]) {
57			case WMM_OUI_SUBTYPE_INFORMATION_ELEMENT:
58			case WMM_OUI_SUBTYPE_PARAMETER_ELEMENT:
59				/*
60				 * Share same pointer since only one of these
61				 * is used and they start with same data.
62				 * Length field can be used to distinguish the
63				 * IEs.
64				 */
65				elems->wmm = pos;
66				elems->wmm_len = elen;
67				break;
68			case WMM_OUI_SUBTYPE_TSPEC_ELEMENT:
69				elems->wmm_tspec = pos;
70				elems->wmm_tspec_len = elen;
71				break;
72			default:
73				wpa_printf(MSG_EXCESSIVE, "unknown WMM "
74					   "information element ignored "
75					   "(subtype=%d len=%lu)",
76					   pos[4], (unsigned long) elen);
77				return -1;
78			}
79			break;
80		case 4:
81			/* Wi-Fi Protected Setup (WPS) IE */
82			elems->wps_ie = pos;
83			elems->wps_ie_len = elen;
84			break;
85		default:
86			wpa_printf(MSG_EXCESSIVE, "Unknown Microsoft "
87				   "information element ignored "
88				   "(type=%d len=%lu)",
89				   pos[3], (unsigned long) elen);
90			return -1;
91		}
92		break;
93
94	case OUI_WFA:
95		switch (pos[3]) {
96		case P2P_OUI_TYPE:
97			/* Wi-Fi Alliance - P2P IE */
98			elems->p2p = pos;
99			elems->p2p_len = elen;
100			break;
101		case WFD_OUI_TYPE:
102			/* Wi-Fi Alliance - WFD IE */
103			elems->wfd = pos;
104			elems->wfd_len = elen;
105			break;
106		case HS20_INDICATION_OUI_TYPE:
107			/* Hotspot 2.0 */
108			elems->hs20 = pos;
109			elems->hs20_len = elen;
110			break;
111		default:
112			wpa_printf(MSG_MSGDUMP, "Unknown WFA "
113				   "information element ignored "
114				   "(type=%d len=%lu)\n",
115				   pos[3], (unsigned long) elen);
116			return -1;
117		}
118		break;
119
120	case OUI_BROADCOM:
121		switch (pos[3]) {
122		case VENDOR_HT_CAPAB_OUI_TYPE:
123			elems->vendor_ht_cap = pos;
124			elems->vendor_ht_cap_len = elen;
125			break;
126		default:
127			wpa_printf(MSG_EXCESSIVE, "Unknown Broadcom "
128				   "information element ignored "
129				   "(type=%d len=%lu)",
130				   pos[3], (unsigned long) elen);
131			return -1;
132		}
133		break;
134
135	default:
136		wpa_printf(MSG_EXCESSIVE, "unknown vendor specific "
137			   "information element ignored (vendor OUI "
138			   "%02x:%02x:%02x len=%lu)",
139			   pos[0], pos[1], pos[2], (unsigned long) elen);
140		return -1;
141	}
142
143	return 0;
144}
145
146
147/**
148 * ieee802_11_parse_elems - Parse information elements in management frames
149 * @start: Pointer to the start of IEs
150 * @len: Length of IE buffer in octets
151 * @elems: Data structure for parsed elements
152 * @show_errors: Whether to show parsing errors in debug log
153 * Returns: Parsing result
154 */
155ParseRes ieee802_11_parse_elems(const u8 *start, size_t len,
156				struct ieee802_11_elems *elems,
157				int show_errors)
158{
159	size_t left = len;
160	const u8 *pos = start;
161	int unknown = 0;
162
163	os_memset(elems, 0, sizeof(*elems));
164
165	while (left >= 2) {
166		u8 id, elen;
167
168		id = *pos++;
169		elen = *pos++;
170		left -= 2;
171
172		if (elen > left) {
173			if (show_errors) {
174				wpa_printf(MSG_DEBUG, "IEEE 802.11 element "
175					   "parse failed (id=%d elen=%d "
176					   "left=%lu)",
177					   id, elen, (unsigned long) left);
178				wpa_hexdump(MSG_MSGDUMP, "IEs", start, len);
179			}
180			return ParseFailed;
181		}
182
183		switch (id) {
184		case WLAN_EID_SSID:
185			elems->ssid = pos;
186			elems->ssid_len = elen;
187			break;
188		case WLAN_EID_SUPP_RATES:
189			elems->supp_rates = pos;
190			elems->supp_rates_len = elen;
191			break;
192		case WLAN_EID_DS_PARAMS:
193			elems->ds_params = pos;
194			elems->ds_params_len = elen;
195			break;
196		case WLAN_EID_CF_PARAMS:
197		case WLAN_EID_TIM:
198			break;
199		case WLAN_EID_CHALLENGE:
200			elems->challenge = pos;
201			elems->challenge_len = elen;
202			break;
203		case WLAN_EID_ERP_INFO:
204			elems->erp_info = pos;
205			elems->erp_info_len = elen;
206			break;
207		case WLAN_EID_EXT_SUPP_RATES:
208			elems->ext_supp_rates = pos;
209			elems->ext_supp_rates_len = elen;
210			break;
211		case WLAN_EID_VENDOR_SPECIFIC:
212			if (ieee802_11_parse_vendor_specific(pos, elen,
213							     elems,
214							     show_errors))
215				unknown++;
216			break;
217		case WLAN_EID_RSN:
218			elems->rsn_ie = pos;
219			elems->rsn_ie_len = elen;
220			break;
221		case WLAN_EID_PWR_CAPABILITY:
222			break;
223		case WLAN_EID_SUPPORTED_CHANNELS:
224			elems->supp_channels = pos;
225			elems->supp_channels_len = elen;
226			break;
227		case WLAN_EID_MOBILITY_DOMAIN:
228			elems->mdie = pos;
229			elems->mdie_len = elen;
230			break;
231		case WLAN_EID_FAST_BSS_TRANSITION:
232			elems->ftie = pos;
233			elems->ftie_len = elen;
234			break;
235		case WLAN_EID_TIMEOUT_INTERVAL:
236			elems->timeout_int = pos;
237			elems->timeout_int_len = elen;
238			break;
239		case WLAN_EID_HT_CAP:
240			elems->ht_capabilities = pos;
241			elems->ht_capabilities_len = elen;
242			break;
243		case WLAN_EID_HT_OPERATION:
244			elems->ht_operation = pos;
245			elems->ht_operation_len = elen;
246			break;
247		case WLAN_EID_VHT_CAP:
248			elems->vht_capabilities = pos;
249			elems->vht_capabilities_len = elen;
250			break;
251		case WLAN_EID_VHT_OPERATION:
252			elems->vht_operation = pos;
253			elems->vht_operation_len = elen;
254			break;
255		case WLAN_EID_LINK_ID:
256			if (elen < 18)
257				break;
258			elems->link_id = pos;
259			break;
260		case WLAN_EID_INTERWORKING:
261			elems->interworking = pos;
262			elems->interworking_len = elen;
263			break;
264		case WLAN_EID_QOS_MAP_SET:
265			if (elen < 16)
266				break;
267			elems->qos_map_set = pos;
268			elems->qos_map_set_len = elen;
269			break;
270		case WLAN_EID_EXT_CAPAB:
271			elems->ext_capab = pos;
272			elems->ext_capab_len = elen;
273			break;
274		case WLAN_EID_BSS_MAX_IDLE_PERIOD:
275			if (elen < 3)
276				break;
277			elems->bss_max_idle_period = pos;
278			break;
279		case WLAN_EID_SSID_LIST:
280			elems->ssid_list = pos;
281			elems->ssid_list_len = elen;
282			break;
283		default:
284			unknown++;
285			if (!show_errors)
286				break;
287			wpa_printf(MSG_MSGDUMP, "IEEE 802.11 element parse "
288				   "ignored unknown element (id=%d elen=%d)",
289				   id, elen);
290			break;
291		}
292
293		left -= elen;
294		pos += elen;
295	}
296
297	if (left)
298		return ParseFailed;
299
300	return unknown ? ParseUnknown : ParseOK;
301}
302
303
304int ieee802_11_ie_count(const u8 *ies, size_t ies_len)
305{
306	int count = 0;
307	const u8 *pos, *end;
308
309	if (ies == NULL)
310		return 0;
311
312	pos = ies;
313	end = ies + ies_len;
314
315	while (pos + 2 <= end) {
316		if (pos + 2 + pos[1] > end)
317			break;
318		count++;
319		pos += 2 + pos[1];
320	}
321
322	return count;
323}
324
325
326struct wpabuf * ieee802_11_vendor_ie_concat(const u8 *ies, size_t ies_len,
327					    u32 oui_type)
328{
329	struct wpabuf *buf;
330	const u8 *end, *pos, *ie;
331
332	pos = ies;
333	end = ies + ies_len;
334	ie = NULL;
335
336	while (pos + 1 < end) {
337		if (pos + 2 + pos[1] > end)
338			return NULL;
339		if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
340		    WPA_GET_BE32(&pos[2]) == oui_type) {
341			ie = pos;
342			break;
343		}
344		pos += 2 + pos[1];
345	}
346
347	if (ie == NULL)
348		return NULL; /* No specified vendor IE found */
349
350	buf = wpabuf_alloc(ies_len);
351	if (buf == NULL)
352		return NULL;
353
354	/*
355	 * There may be multiple vendor IEs in the message, so need to
356	 * concatenate their data fields.
357	 */
358	while (pos + 1 < end) {
359		if (pos + 2 + pos[1] > end)
360			break;
361		if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
362		    WPA_GET_BE32(&pos[2]) == oui_type)
363			wpabuf_put_data(buf, pos + 6, pos[1] - 4);
364		pos += 2 + pos[1];
365	}
366
367	return buf;
368}
369
370
371const u8 * get_hdr_bssid(const struct ieee80211_hdr *hdr, size_t len)
372{
373	u16 fc, type, stype;
374
375	/*
376	 * PS-Poll frames are 16 bytes. All other frames are
377	 * 24 bytes or longer.
378	 */
379	if (len < 16)
380		return NULL;
381
382	fc = le_to_host16(hdr->frame_control);
383	type = WLAN_FC_GET_TYPE(fc);
384	stype = WLAN_FC_GET_STYPE(fc);
385
386	switch (type) {
387	case WLAN_FC_TYPE_DATA:
388		if (len < 24)
389			return NULL;
390		switch (fc & (WLAN_FC_FROMDS | WLAN_FC_TODS)) {
391		case WLAN_FC_FROMDS | WLAN_FC_TODS:
392		case WLAN_FC_TODS:
393			return hdr->addr1;
394		case WLAN_FC_FROMDS:
395			return hdr->addr2;
396		default:
397			return NULL;
398		}
399	case WLAN_FC_TYPE_CTRL:
400		if (stype != WLAN_FC_STYPE_PSPOLL)
401			return NULL;
402		return hdr->addr1;
403	case WLAN_FC_TYPE_MGMT:
404		return hdr->addr3;
405	default:
406		return NULL;
407	}
408}
409
410
411int hostapd_config_wmm_ac(struct hostapd_wmm_ac_params wmm_ac_params[],
412			  const char *name, const char *val)
413{
414	int num, v;
415	const char *pos;
416	struct hostapd_wmm_ac_params *ac;
417
418	/* skip 'wme_ac_' or 'wmm_ac_' prefix */
419	pos = name + 7;
420	if (os_strncmp(pos, "be_", 3) == 0) {
421		num = 0;
422		pos += 3;
423	} else if (os_strncmp(pos, "bk_", 3) == 0) {
424		num = 1;
425		pos += 3;
426	} else if (os_strncmp(pos, "vi_", 3) == 0) {
427		num = 2;
428		pos += 3;
429	} else if (os_strncmp(pos, "vo_", 3) == 0) {
430		num = 3;
431		pos += 3;
432	} else {
433		wpa_printf(MSG_ERROR, "Unknown WMM name '%s'", pos);
434		return -1;
435	}
436
437	ac = &wmm_ac_params[num];
438
439	if (os_strcmp(pos, "aifs") == 0) {
440		v = atoi(val);
441		if (v < 1 || v > 255) {
442			wpa_printf(MSG_ERROR, "Invalid AIFS value %d", v);
443			return -1;
444		}
445		ac->aifs = v;
446	} else if (os_strcmp(pos, "cwmin") == 0) {
447		v = atoi(val);
448		if (v < 0 || v > 12) {
449			wpa_printf(MSG_ERROR, "Invalid cwMin value %d", v);
450			return -1;
451		}
452		ac->cwmin = v;
453	} else if (os_strcmp(pos, "cwmax") == 0) {
454		v = atoi(val);
455		if (v < 0 || v > 12) {
456			wpa_printf(MSG_ERROR, "Invalid cwMax value %d", v);
457			return -1;
458		}
459		ac->cwmax = v;
460	} else if (os_strcmp(pos, "txop_limit") == 0) {
461		v = atoi(val);
462		if (v < 0 || v > 0xffff) {
463			wpa_printf(MSG_ERROR, "Invalid txop value %d", v);
464			return -1;
465		}
466		ac->txop_limit = v;
467	} else if (os_strcmp(pos, "acm") == 0) {
468		v = atoi(val);
469		if (v < 0 || v > 1) {
470			wpa_printf(MSG_ERROR, "Invalid acm value %d", v);
471			return -1;
472		}
473		ac->admission_control_mandatory = v;
474	} else {
475		wpa_printf(MSG_ERROR, "Unknown wmm_ac_ field '%s'", pos);
476		return -1;
477	}
478
479	return 0;
480}
481
482
483enum hostapd_hw_mode ieee80211_freq_to_chan(int freq, u8 *channel)
484{
485	enum hostapd_hw_mode mode = NUM_HOSTAPD_MODES;
486
487	if (freq >= 2412 && freq <= 2472) {
488		mode = HOSTAPD_MODE_IEEE80211G;
489		*channel = (freq - 2407) / 5;
490	} else if (freq == 2484) {
491		mode = HOSTAPD_MODE_IEEE80211B;
492		*channel = 14;
493	} else if (freq >= 4900 && freq < 5000) {
494		mode = HOSTAPD_MODE_IEEE80211A;
495		*channel = (freq - 4000) / 5;
496	} else if (freq >= 5000 && freq < 5900) {
497		mode = HOSTAPD_MODE_IEEE80211A;
498		*channel = (freq - 5000) / 5;
499	} else if (freq >= 56160 + 2160 * 1 && freq <= 56160 + 2160 * 4) {
500		mode = HOSTAPD_MODE_IEEE80211AD;
501		*channel = (freq - 56160) / 2160;
502	}
503
504	return mode;
505}
506
507
508static int is_11b(u8 rate)
509{
510	return rate == 0x02 || rate == 0x04 || rate == 0x0b || rate == 0x16;
511}
512
513
514int supp_rates_11b_only(struct ieee802_11_elems *elems)
515{
516	int num_11b = 0, num_others = 0;
517	int i;
518
519	if (elems->supp_rates == NULL && elems->ext_supp_rates == NULL)
520		return 0;
521
522	for (i = 0; elems->supp_rates && i < elems->supp_rates_len; i++) {
523		if (is_11b(elems->supp_rates[i]))
524			num_11b++;
525		else
526			num_others++;
527	}
528
529	for (i = 0; elems->ext_supp_rates && i < elems->ext_supp_rates_len;
530	     i++) {
531		if (is_11b(elems->ext_supp_rates[i]))
532			num_11b++;
533		else
534			num_others++;
535	}
536
537	return num_11b > 0 && num_others == 0;
538}
539