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1 /*
2  *
3  *  BlueZ - Bluetooth protocol stack for Linux
4  *
5  *  Copyright (C) 2011  Nokia Corporation
6  *  Copyright (C) 2011  Marcel Holtmann <marcel@holtmann.org>
7  *
8  *
9  *  This program is free software; you can redistribute it and/or modify
10  *  it under the terms of the GNU General Public License as published by
11  *  the Free Software Foundation; either version 2 of the License, or
12  *  (at your option) any later version.
13  *
14  *  This program is distributed in the hope that it will be useful,
15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  *  GNU General Public License for more details.
18  *
19  *  You should have received a copy of the GNU General Public License
20  *  along with this program; if not, write to the Free Software
21  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
22  *
23  */
24 #include <errno.h>
25 #include <stdlib.h>
26 #include <stdint.h>
27 #include <glib.h>
28 
29 #include <bluetooth/bluetooth.h>
30 #include <bluetooth/hci.h>
31 #include <bluetooth/sdp.h>
32 
33 #include "glib-helper.h"
34 #include "eir.h"
35 
36 #define EIR_FLAGS                   0x01  /* flags */
37 #define EIR_UUID16_SOME             0x02  /* 16-bit UUID, more available */
38 #define EIR_UUID16_ALL              0x03  /* 16-bit UUID, all listed */
39 #define EIR_UUID32_SOME             0x04  /* 32-bit UUID, more available */
40 #define EIR_UUID32_ALL              0x05  /* 32-bit UUID, all listed */
41 #define EIR_UUID128_SOME            0x06  /* 128-bit UUID, more available */
42 #define EIR_UUID128_ALL             0x07  /* 128-bit UUID, all listed */
43 #define EIR_NAME_SHORT              0x08  /* shortened local name */
44 #define EIR_NAME_COMPLETE           0x09  /* complete local name */
45 #define EIR_TX_POWER                0x0A  /* transmit power level */
46 #define EIR_DEVICE_ID               0x10  /* device ID */
47 
eir_data_free(struct eir_data * eir)48 void eir_data_free(struct eir_data *eir)
49 {
50 	g_slist_foreach(eir->services, (GFunc) g_free, NULL);
51 	g_slist_free(eir->services);
52 	g_free(eir->name);
53 }
54 
eir_parse(struct eir_data * eir,uint8_t * eir_data)55 int eir_parse(struct eir_data *eir, uint8_t *eir_data)
56 {
57 	uint16_t len = 0;
58 	size_t total;
59 	size_t uuid16_count = 0;
60 	size_t uuid32_count = 0;
61 	size_t uuid128_count = 0;
62 	uint8_t *uuid16 = NULL;
63 	uint8_t *uuid32 = NULL;
64 	uint8_t *uuid128 = NULL;
65 	uuid_t service;
66 	char *uuid_str;
67 	unsigned int i;
68 
69 	eir->flags = -1;
70 
71 	/* No EIR data to parse */
72 	if (eir_data == NULL)
73 		return 0;
74 
75 	while (len < HCI_MAX_EIR_LENGTH - 1) {
76 		uint8_t field_len = eir_data[0];
77 
78 		/* Check for the end of EIR */
79 		if (field_len == 0)
80 			break;
81 
82 		switch (eir_data[1]) {
83 		case EIR_UUID16_SOME:
84 		case EIR_UUID16_ALL:
85 			uuid16_count = field_len / 2;
86 			uuid16 = &eir_data[2];
87 			break;
88 		case EIR_UUID32_SOME:
89 		case EIR_UUID32_ALL:
90 			uuid32_count = field_len / 4;
91 			uuid32 = &eir_data[2];
92 			break;
93 		case EIR_UUID128_SOME:
94 		case EIR_UUID128_ALL:
95 			uuid128_count = field_len / 16;
96 			uuid128 = &eir_data[2];
97 			break;
98 		case EIR_FLAGS:
99 			eir->flags = eir_data[2];
100 			break;
101 		case EIR_NAME_SHORT:
102 		case EIR_NAME_COMPLETE:
103 			if (g_utf8_validate((char *) &eir_data[2],
104 							field_len - 1, NULL))
105 				eir->name = g_strndup((char *) &eir_data[2],
106 								field_len - 1);
107 			else
108 				eir->name = g_strdup("");
109 			eir->name_complete = eir_data[1] == EIR_NAME_COMPLETE;
110 			break;
111 		}
112 
113 		len += field_len + 1;
114 		eir_data += field_len + 1;
115 	}
116 
117 	/* Bail out if got incorrect length */
118 	if (len > HCI_MAX_EIR_LENGTH)
119 		return -EINVAL;
120 
121 	total = uuid16_count + uuid32_count + uuid128_count;
122 
123 	/* No UUIDs were parsed, so skip code below */
124 	if (!total)
125 		return 0;
126 
127 	/* Generate uuids in SDP format (EIR data is Little Endian) */
128 	service.type = SDP_UUID16;
129 	for (i = 0; i < uuid16_count; i++) {
130 		uint16_t val16 = uuid16[1];
131 
132 		val16 = (val16 << 8) + uuid16[0];
133 		service.value.uuid16 = val16;
134 		uuid_str = bt_uuid2string(&service);
135 		eir->services = g_slist_append(eir->services, uuid_str);
136 		uuid16 += 2;
137 	}
138 
139 	service.type = SDP_UUID32;
140 	for (i = uuid16_count; i < uuid32_count + uuid16_count; i++) {
141 		uint32_t val32 = uuid32[3];
142 		int k;
143 
144 		for (k = 2; k >= 0; k--)
145 			val32 = (val32 << 8) + uuid32[k];
146 
147 		service.value.uuid32 = val32;
148 		uuid_str = bt_uuid2string(&service);
149 		eir->services = g_slist_append(eir->services, uuid_str);
150 		uuid32 += 4;
151 	}
152 
153 	service.type = SDP_UUID128;
154 	for (i = uuid32_count + uuid16_count; i < total; i++) {
155 		int k;
156 
157 		for (k = 0; k < 16; k++)
158 			service.value.uuid128.data[k] = uuid128[16 - k - 1];
159 
160 		uuid_str = bt_uuid2string(&service);
161 		eir->services = g_slist_append(eir->services, uuid_str);
162 		uuid128 += 16;
163 	}
164 
165 	return 0;
166 }
167 
168 #define SIZEOF_UUID128 16
169 
eir_generate_uuid128(GSList * list,uint8_t * ptr,uint16_t * eir_len)170 static void eir_generate_uuid128(GSList *list, uint8_t *ptr, uint16_t *eir_len)
171 {
172 	int i, k, uuid_count = 0;
173 	uint16_t len = *eir_len;
174 	uint8_t *uuid128;
175 	gboolean truncated = FALSE;
176 
177 	/* Store UUIDs in place, skip 2 bytes to write type and length later */
178 	uuid128 = ptr + 2;
179 
180 	for (; list; list = list->next) {
181 		struct uuid_info *uuid = list->data;
182 		uint8_t *uuid128_data = uuid->uuid.value.uuid128.data;
183 
184 		if (uuid->uuid.type != SDP_UUID128)
185 			continue;
186 
187 		/* Stop if not enough space to put next UUID128 */
188 		if ((len + 2 + SIZEOF_UUID128) > HCI_MAX_EIR_LENGTH) {
189 			truncated = TRUE;
190 			break;
191 		}
192 
193 		/* Check for duplicates, EIR data is Little Endian */
194 		for (i = 0; i < uuid_count; i++) {
195 			for (k = 0; k < SIZEOF_UUID128; k++) {
196 				if (uuid128[i * SIZEOF_UUID128 + k] !=
197 					uuid128_data[SIZEOF_UUID128 - 1 - k])
198 					break;
199 			}
200 			if (k == SIZEOF_UUID128)
201 				break;
202 		}
203 
204 		if (i < uuid_count)
205 			continue;
206 
207 		/* EIR data is Little Endian */
208 		for (k = 0; k < SIZEOF_UUID128; k++)
209 			uuid128[uuid_count * SIZEOF_UUID128 + k] =
210 				uuid128_data[SIZEOF_UUID128 - 1 - k];
211 
212 		len += SIZEOF_UUID128;
213 		uuid_count++;
214 	}
215 
216 	if (uuid_count > 0 || truncated) {
217 		/* EIR Data length */
218 		ptr[0] = (uuid_count * SIZEOF_UUID128) + 1;
219 		/* EIR Data type */
220 		ptr[1] = truncated ? EIR_UUID128_SOME : EIR_UUID128_ALL;
221 		len += 2;
222 		*eir_len = len;
223 	}
224 }
225 
eir_create(const char * name,int8_t tx_power,uint16_t did_vendor,uint16_t did_product,uint16_t did_version,GSList * uuids,uint8_t * data)226 void eir_create(const char *name, int8_t tx_power, uint16_t did_vendor,
227 			uint16_t did_product, uint16_t did_version,
228 			GSList *uuids, uint8_t *data)
229 {
230 	GSList *l;
231 	uint8_t *ptr = data;
232 	uint16_t eir_len = 0;
233 	uint16_t uuid16[HCI_MAX_EIR_LENGTH / 2];
234 	int i, uuid_count = 0;
235 	gboolean truncated = FALSE;
236 	size_t name_len;
237 
238 	name_len = strlen(name);
239 
240 	if (name_len > 0) {
241 		/* EIR Data type */
242 		if (name_len > 48) {
243 			name_len = 48;
244 			ptr[1] = EIR_NAME_SHORT;
245 		} else
246 			ptr[1] = EIR_NAME_COMPLETE;
247 
248 		/* EIR Data length */
249 		ptr[0] = name_len + 1;
250 
251 		memcpy(ptr + 2, name, name_len);
252 
253 		eir_len += (name_len + 2);
254 		ptr += (name_len + 2);
255 	}
256 
257 	if (tx_power != 0) {
258 		*ptr++ = 2;
259 		*ptr++ = EIR_TX_POWER;
260 		*ptr++ = (uint8_t) tx_power;
261 		eir_len += 3;
262 	}
263 
264 	if (did_vendor != 0x0000) {
265 		uint16_t source = 0x0002;
266 		*ptr++ = 9;
267 		*ptr++ = EIR_DEVICE_ID;
268 		*ptr++ = (source & 0x00ff);
269 		*ptr++ = (source & 0xff00) >> 8;
270 		*ptr++ = (did_vendor & 0x00ff);
271 		*ptr++ = (did_vendor & 0xff00) >> 8;
272 		*ptr++ = (did_product & 0x00ff);
273 		*ptr++ = (did_product & 0xff00) >> 8;
274 		*ptr++ = (did_version & 0x00ff);
275 		*ptr++ = (did_version & 0xff00) >> 8;
276 		eir_len += 10;
277 	}
278 
279 	/* Group all UUID16 types */
280 	for (l = uuids; l != NULL; l = g_slist_next(l)) {
281 		struct uuid_info *uuid = l->data;
282 
283 		if (uuid->uuid.type != SDP_UUID16)
284 			continue;
285 
286 		if (uuid->uuid.value.uuid16 < 0x1100)
287 			continue;
288 
289 		if (uuid->uuid.value.uuid16 == PNP_INFO_SVCLASS_ID)
290 			continue;
291 
292 		/* Stop if not enough space to put next UUID16 */
293 		if ((eir_len + 2 + sizeof(uint16_t)) > HCI_MAX_EIR_LENGTH) {
294 			truncated = TRUE;
295 			break;
296 		}
297 
298 		/* Check for duplicates */
299 		for (i = 0; i < uuid_count; i++)
300 			if (uuid16[i] == uuid->uuid.value.uuid16)
301 				break;
302 
303 		if (i < uuid_count)
304 			continue;
305 
306 		uuid16[uuid_count++] = uuid->uuid.value.uuid16;
307 		eir_len += sizeof(uint16_t);
308 	}
309 
310 	if (uuid_count > 0) {
311 		/* EIR Data length */
312 		ptr[0] = (uuid_count * sizeof(uint16_t)) + 1;
313 		/* EIR Data type */
314 		ptr[1] = truncated ? EIR_UUID16_SOME : EIR_UUID16_ALL;
315 
316 		ptr += 2;
317 		eir_len += 2;
318 
319 		for (i = 0; i < uuid_count; i++) {
320 			*ptr++ = (uuid16[i] & 0x00ff);
321 			*ptr++ = (uuid16[i] & 0xff00) >> 8;
322 		}
323 	}
324 
325 	/* Group all UUID128 types */
326 	if (eir_len <= HCI_MAX_EIR_LENGTH - 2)
327 		eir_generate_uuid128(uuids, ptr, &eir_len);
328 }
329