1 /*
2  * Operating classes
3  * Copyright(c) 2015 Intel Deutschland GmbH
4  * Contact Information:
5  * Intel Linux Wireless <ilw@linux.intel.com>
6  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
7  *
8  * This software may be distributed under the terms of the BSD license.
9  * See README for more details.
10  */
11 
12 #include "utils/includes.h"
13 
14 #include "utils/common.h"
15 #include "common/ieee802_11_common.h"
16 #include "wpa_supplicant_i.h"
17 
18 
19 static enum chan_allowed allow_channel(struct hostapd_hw_modes *mode, u8 chan,
20 				       unsigned int *flags)
21 {
22 	int i;
23 
24 	for (i = 0; i < mode->num_channels; i++) {
25 		if (mode->channels[i].chan == chan)
26 			break;
27 	}
28 
29 	if (i == mode->num_channels ||
30 	    (mode->channels[i].flag & HOSTAPD_CHAN_DISABLED))
31 		return NOT_ALLOWED;
32 
33 	if (flags)
34 		*flags = mode->channels[i].flag;
35 
36 	if (mode->channels[i].flag & HOSTAPD_CHAN_NO_IR)
37 		return NO_IR;
38 
39 	return ALLOWED;
40 }
41 
42 
43 static int get_center_80mhz(struct hostapd_hw_modes *mode, u8 channel)
44 {
45 	u8 center_channels[] = { 42, 58, 106, 122, 138, 155 };
46 	size_t i;
47 
48 	if (mode->mode != HOSTAPD_MODE_IEEE80211A)
49 		return 0;
50 
51 	for (i = 0; i < ARRAY_SIZE(center_channels); i++) {
52 		/*
53 		 * In 80 MHz, the bandwidth "spans" 12 channels (e.g., 36-48),
54 		 * so the center channel is 6 channels away from the start/end.
55 		 */
56 		if (channel >= center_channels[i] - 6 &&
57 		    channel <= center_channels[i] + 6)
58 			return center_channels[i];
59 	}
60 
61 	return 0;
62 }
63 
64 
65 static enum chan_allowed verify_80mhz(struct hostapd_hw_modes *mode, u8 channel)
66 {
67 	u8 center_chan;
68 	unsigned int i;
69 	unsigned int no_ir = 0;
70 
71 	center_chan = get_center_80mhz(mode, channel);
72 	if (!center_chan)
73 		return NOT_ALLOWED;
74 
75 	/* check all the channels are available */
76 	for (i = 0; i < 4; i++) {
77 		unsigned int flags;
78 		u8 adj_chan = center_chan - 6 + i * 4;
79 
80 		if (allow_channel(mode, adj_chan, &flags) == NOT_ALLOWED)
81 			return NOT_ALLOWED;
82 
83 		if ((i == 0 && !(flags & HOSTAPD_CHAN_VHT_10_70)) ||
84 		    (i == 1 && !(flags & HOSTAPD_CHAN_VHT_30_50)) ||
85 		    (i == 2 && !(flags & HOSTAPD_CHAN_VHT_50_30)) ||
86 		    (i == 3 && !(flags & HOSTAPD_CHAN_VHT_70_10)))
87 			return NOT_ALLOWED;
88 
89 		if (flags & HOSTAPD_CHAN_NO_IR)
90 			no_ir = 1;
91 	}
92 
93 	if (no_ir)
94 		return NO_IR;
95 
96 	return ALLOWED;
97 }
98 
99 
100 static int get_center_160mhz(struct hostapd_hw_modes *mode, u8 channel)
101 {
102 	u8 center_channels[] = { 50, 114 };
103 	unsigned int i;
104 
105 	if (mode->mode != HOSTAPD_MODE_IEEE80211A)
106 		return 0;
107 
108 	for (i = 0; i < ARRAY_SIZE(center_channels); i++) {
109 		/*
110 		 * In 160 MHz, the bandwidth "spans" 28 channels (e.g., 36-64),
111 		 * so the center channel is 14 channels away from the start/end.
112 		 */
113 		if (channel >= center_channels[i] - 14 &&
114 		    channel <= center_channels[i] + 14)
115 			return center_channels[i];
116 	}
117 
118 	return 0;
119 }
120 
121 
122 static enum chan_allowed verify_160mhz(struct hostapd_hw_modes *mode,
123 				       u8 channel)
124 {
125 	u8 center_chan;
126 	unsigned int i;
127 	unsigned int no_ir = 0;
128 
129 	center_chan = get_center_160mhz(mode, channel);
130 	if (!center_chan)
131 		return NOT_ALLOWED;
132 
133 	/* Check all the channels are available */
134 	for (i = 0; i < 8; i++) {
135 		unsigned int flags;
136 		u8 adj_chan = center_chan - 14 + i * 4;
137 
138 		if (allow_channel(mode, adj_chan, &flags) == NOT_ALLOWED)
139 			return NOT_ALLOWED;
140 
141 		if ((i == 0 && !(flags & HOSTAPD_CHAN_VHT_10_150)) ||
142 		    (i == 1 && !(flags & HOSTAPD_CHAN_VHT_30_130)) ||
143 		    (i == 2 && !(flags & HOSTAPD_CHAN_VHT_50_110)) ||
144 		    (i == 3 && !(flags & HOSTAPD_CHAN_VHT_70_90)) ||
145 		    (i == 4 && !(flags & HOSTAPD_CHAN_VHT_90_70)) ||
146 		    (i == 5 && !(flags & HOSTAPD_CHAN_VHT_110_50)) ||
147 		    (i == 6 && !(flags & HOSTAPD_CHAN_VHT_130_30)) ||
148 		    (i == 7 && !(flags & HOSTAPD_CHAN_VHT_150_10)))
149 			return NOT_ALLOWED;
150 
151 		if (flags & HOSTAPD_CHAN_NO_IR)
152 			no_ir = 1;
153 	}
154 
155 	if (no_ir)
156 		return NO_IR;
157 
158 	return ALLOWED;
159 }
160 
161 
162 enum chan_allowed verify_channel(struct hostapd_hw_modes *mode, u8 channel,
163 				 u8 bw)
164 {
165 	unsigned int flag = 0;
166 	enum chan_allowed res, res2;
167 
168 	res2 = res = allow_channel(mode, channel, &flag);
169 	if (bw == BW40MINUS) {
170 		if (!(flag & HOSTAPD_CHAN_HT40MINUS))
171 			return NOT_ALLOWED;
172 		res2 = allow_channel(mode, channel - 4, NULL);
173 	} else if (bw == BW40PLUS) {
174 		if (!(flag & HOSTAPD_CHAN_HT40PLUS))
175 			return NOT_ALLOWED;
176 		res2 = allow_channel(mode, channel + 4, NULL);
177 	} else if (bw == BW80) {
178 		/*
179 		 * channel is a center channel and as such, not necessarily a
180 		 * valid 20 MHz channels. Override earlier allow_channel()
181 		 * result and use only the 80 MHz specific version.
182 		 */
183 		res2 = res = verify_80mhz(mode, channel);
184 	} else if (bw == BW160) {
185 		/*
186 		 * channel is a center channel and as such, not necessarily a
187 		 * valid 20 MHz channels. Override earlier allow_channel()
188 		 * result and use only the 160 MHz specific version.
189 		 */
190 		res2 = res = verify_160mhz(mode, channel);
191 	} else if (bw == BW80P80) {
192 		/*
193 		 * channel is a center channel and as such, not necessarily a
194 		 * valid 20 MHz channels. Override earlier allow_channel()
195 		 * result and use only the 80 MHz specific version.
196 		 */
197 		res2 = res = verify_80mhz(mode, channel);
198 	}
199 
200 	if (res == NOT_ALLOWED || res2 == NOT_ALLOWED)
201 		return NOT_ALLOWED;
202 
203 	if (res == NO_IR || res2 == NO_IR)
204 		return NO_IR;
205 
206 	return ALLOWED;
207 }
208 
209 
210 static int wpas_op_class_supported(struct wpa_supplicant *wpa_s,
211 				   const struct oper_class_map *op_class)
212 {
213 	int chan;
214 	size_t i;
215 	struct hostapd_hw_modes *mode;
216 	int found;
217 
218 	mode = get_mode(wpa_s->hw.modes, wpa_s->hw.num_modes, op_class->mode);
219 	if (!mode)
220 		return 0;
221 
222 	if (op_class->op_class == 128) {
223 		u8 channels[] = { 42, 58, 106, 122, 138, 155 };
224 
225 		for (i = 0; i < ARRAY_SIZE(channels); i++) {
226 			if (verify_channel(mode, channels[i], op_class->bw) !=
227 			    NOT_ALLOWED)
228 				return 1;
229 		}
230 
231 		return 0;
232 	}
233 
234 	if (op_class->op_class == 129) {
235 		/* Check if either 160 MHz channels is allowed */
236 		return verify_channel(mode, 50, op_class->bw) != NOT_ALLOWED ||
237 			verify_channel(mode, 114, op_class->bw) != NOT_ALLOWED;
238 	}
239 
240 	if (op_class->op_class == 130) {
241 		/* Need at least two non-contiguous 80 MHz segments */
242 		found = 0;
243 
244 		if (verify_channel(mode, 42, op_class->bw) != NOT_ALLOWED ||
245 		    verify_channel(mode, 58, op_class->bw) != NOT_ALLOWED)
246 			found++;
247 		if (verify_channel(mode, 106, op_class->bw) != NOT_ALLOWED ||
248 		    verify_channel(mode, 122, op_class->bw) != NOT_ALLOWED ||
249 		    verify_channel(mode, 138, op_class->bw) != NOT_ALLOWED)
250 			found++;
251 		if (verify_channel(mode, 106, op_class->bw) != NOT_ALLOWED &&
252 		    verify_channel(mode, 138, op_class->bw) != NOT_ALLOWED)
253 			found++;
254 		if (verify_channel(mode, 155, op_class->bw) != NOT_ALLOWED)
255 			found++;
256 
257 		if (found >= 2)
258 			return 1;
259 
260 		return 0;
261 	}
262 
263 	found = 0;
264 	for (chan = op_class->min_chan; chan <= op_class->max_chan;
265 	     chan += op_class->inc) {
266 		if (verify_channel(mode, chan, op_class->bw) != NOT_ALLOWED) {
267 			found = 1;
268 			break;
269 		}
270 	}
271 
272 	return found;
273 }
274 
275 
276 size_t wpas_supp_op_class_ie(struct wpa_supplicant *wpa_s, int freq, u8 *pos,
277 			      size_t len)
278 {
279 	struct wpabuf *buf;
280 	u8 op, current, chan;
281 	u8 *ie_len;
282 	size_t res;
283 
284 	/*
285 	 * Assume 20 MHz channel for now.
286 	 * TODO: Use the secondary channel and VHT channel width that will be
287 	 * used after association.
288 	 */
289 	if (ieee80211_freq_to_channel_ext(freq, 0, VHT_CHANWIDTH_USE_HT,
290 					  &current, &chan) == NUM_HOSTAPD_MODES)
291 		return 0;
292 
293 	/*
294 	 * Need 3 bytes for EID, length, and current operating class, plus
295 	 * 1 byte for every other supported operating class.
296 	 */
297 	buf = wpabuf_alloc(global_op_class_size + 3);
298 	if (!buf)
299 		return 0;
300 
301 	wpabuf_put_u8(buf, WLAN_EID_SUPPORTED_OPERATING_CLASSES);
302 	/* Will set the length later, putting a placeholder */
303 	ie_len = wpabuf_put(buf, 1);
304 	wpabuf_put_u8(buf, current);
305 
306 	for (op = 0; global_op_class[op].op_class; op++) {
307 		if (wpas_op_class_supported(wpa_s, &global_op_class[op]))
308 			wpabuf_put_u8(buf, global_op_class[op].op_class);
309 	}
310 
311 	*ie_len = wpabuf_len(buf) - 2;
312 	if (*ie_len < 2 || wpabuf_len(buf) > len) {
313 		wpa_printf(MSG_ERROR,
314 			   "Failed to add supported operating classes IE");
315 		res = 0;
316 	} else {
317 		os_memcpy(pos, wpabuf_head(buf), wpabuf_len(buf));
318 		res = wpabuf_len(buf);
319 		wpa_hexdump_buf(MSG_DEBUG,
320 				"Added supported operating classes IE", buf);
321 	}
322 
323 	wpabuf_free(buf);
324 	return res;
325 }
326