1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * BlueZ - Bluetooth protocol stack for Linux
4 *
5 * Copyright (C) 2021 Intel Corporation
6 */
7
8 #include <net/bluetooth/bluetooth.h>
9 #include <net/bluetooth/hci_core.h>
10 #include <net/bluetooth/mgmt.h>
11
12 #include "eir.h"
13
14 #define PNP_INFO_SVCLASS_ID 0x1200
15
eir_append_local_name(struct hci_dev * hdev,u8 * ptr,u8 ad_len)16 u8 eir_append_local_name(struct hci_dev *hdev, u8 *ptr, u8 ad_len)
17 {
18 size_t short_len;
19 size_t complete_len;
20
21 /* no space left for name (+ type + len) */
22 if ((max_adv_len(hdev) - ad_len) < HCI_MAX_SHORT_NAME_LENGTH + 2)
23 return ad_len;
24
25 /* use complete name if present and fits */
26 complete_len = strnlen(hdev->dev_name, sizeof(hdev->dev_name));
27 if (complete_len && complete_len <= HCI_MAX_SHORT_NAME_LENGTH)
28 return eir_append_data(ptr, ad_len, EIR_NAME_COMPLETE,
29 hdev->dev_name, complete_len);
30
31 /* use short name if present */
32 short_len = strnlen(hdev->short_name, sizeof(hdev->short_name));
33 if (short_len)
34 return eir_append_data(ptr, ad_len, EIR_NAME_SHORT,
35 hdev->short_name,
36 short_len);
37
38 /* use shortened full name if present, we already know that name
39 * is longer then HCI_MAX_SHORT_NAME_LENGTH
40 */
41 if (complete_len)
42 return eir_append_data(ptr, ad_len, EIR_NAME_SHORT,
43 hdev->dev_name,
44 HCI_MAX_SHORT_NAME_LENGTH);
45
46 return ad_len;
47 }
48
eir_append_appearance(struct hci_dev * hdev,u8 * ptr,u8 ad_len)49 u8 eir_append_appearance(struct hci_dev *hdev, u8 *ptr, u8 ad_len)
50 {
51 return eir_append_le16(ptr, ad_len, EIR_APPEARANCE, hdev->appearance);
52 }
53
eir_append_service_data(u8 * eir,u16 eir_len,u16 uuid,u8 * data,u8 data_len)54 u8 eir_append_service_data(u8 *eir, u16 eir_len, u16 uuid, u8 *data,
55 u8 data_len)
56 {
57 eir[eir_len++] = sizeof(u8) + sizeof(uuid) + data_len;
58 eir[eir_len++] = EIR_SERVICE_DATA;
59 put_unaligned_le16(uuid, &eir[eir_len]);
60 eir_len += sizeof(uuid);
61 memcpy(&eir[eir_len], data, data_len);
62 eir_len += data_len;
63
64 return eir_len;
65 }
66
create_uuid16_list(struct hci_dev * hdev,u8 * data,ptrdiff_t len)67 static u8 *create_uuid16_list(struct hci_dev *hdev, u8 *data, ptrdiff_t len)
68 {
69 u8 *ptr = data, *uuids_start = NULL;
70 struct bt_uuid *uuid;
71
72 if (len < 4)
73 return ptr;
74
75 list_for_each_entry(uuid, &hdev->uuids, list) {
76 u16 uuid16;
77
78 if (uuid->size != 16)
79 continue;
80
81 uuid16 = get_unaligned_le16(&uuid->uuid[12]);
82 if (uuid16 < 0x1100)
83 continue;
84
85 if (uuid16 == PNP_INFO_SVCLASS_ID)
86 continue;
87
88 if (!uuids_start) {
89 uuids_start = ptr;
90 uuids_start[0] = 1;
91 uuids_start[1] = EIR_UUID16_ALL;
92 ptr += 2;
93 }
94
95 /* Stop if not enough space to put next UUID */
96 if ((ptr - data) + sizeof(u16) > len) {
97 uuids_start[1] = EIR_UUID16_SOME;
98 break;
99 }
100
101 *ptr++ = (uuid16 & 0x00ff);
102 *ptr++ = (uuid16 & 0xff00) >> 8;
103 uuids_start[0] += sizeof(uuid16);
104 }
105
106 return ptr;
107 }
108
create_uuid32_list(struct hci_dev * hdev,u8 * data,ptrdiff_t len)109 static u8 *create_uuid32_list(struct hci_dev *hdev, u8 *data, ptrdiff_t len)
110 {
111 u8 *ptr = data, *uuids_start = NULL;
112 struct bt_uuid *uuid;
113
114 if (len < 6)
115 return ptr;
116
117 list_for_each_entry(uuid, &hdev->uuids, list) {
118 if (uuid->size != 32)
119 continue;
120
121 if (!uuids_start) {
122 uuids_start = ptr;
123 uuids_start[0] = 1;
124 uuids_start[1] = EIR_UUID32_ALL;
125 ptr += 2;
126 }
127
128 /* Stop if not enough space to put next UUID */
129 if ((ptr - data) + sizeof(u32) > len) {
130 uuids_start[1] = EIR_UUID32_SOME;
131 break;
132 }
133
134 memcpy(ptr, &uuid->uuid[12], sizeof(u32));
135 ptr += sizeof(u32);
136 uuids_start[0] += sizeof(u32);
137 }
138
139 return ptr;
140 }
141
create_uuid128_list(struct hci_dev * hdev,u8 * data,ptrdiff_t len)142 static u8 *create_uuid128_list(struct hci_dev *hdev, u8 *data, ptrdiff_t len)
143 {
144 u8 *ptr = data, *uuids_start = NULL;
145 struct bt_uuid *uuid;
146
147 if (len < 18)
148 return ptr;
149
150 list_for_each_entry(uuid, &hdev->uuids, list) {
151 if (uuid->size != 128)
152 continue;
153
154 if (!uuids_start) {
155 uuids_start = ptr;
156 uuids_start[0] = 1;
157 uuids_start[1] = EIR_UUID128_ALL;
158 ptr += 2;
159 }
160
161 /* Stop if not enough space to put next UUID */
162 if ((ptr - data) + 16 > len) {
163 uuids_start[1] = EIR_UUID128_SOME;
164 break;
165 }
166
167 memcpy(ptr, uuid->uuid, 16);
168 ptr += 16;
169 uuids_start[0] += 16;
170 }
171
172 return ptr;
173 }
174
eir_create(struct hci_dev * hdev,u8 * data)175 void eir_create(struct hci_dev *hdev, u8 *data)
176 {
177 u8 *ptr = data;
178 size_t name_len;
179
180 name_len = strnlen(hdev->dev_name, sizeof(hdev->dev_name));
181
182 if (name_len > 0) {
183 /* EIR Data type */
184 if (name_len > 48) {
185 name_len = 48;
186 ptr[1] = EIR_NAME_SHORT;
187 } else {
188 ptr[1] = EIR_NAME_COMPLETE;
189 }
190
191 /* EIR Data length */
192 ptr[0] = name_len + 1;
193
194 memcpy(ptr + 2, hdev->dev_name, name_len);
195
196 ptr += (name_len + 2);
197 }
198
199 if (hdev->inq_tx_power != HCI_TX_POWER_INVALID) {
200 ptr[0] = 2;
201 ptr[1] = EIR_TX_POWER;
202 ptr[2] = (u8)hdev->inq_tx_power;
203
204 ptr += 3;
205 }
206
207 if (hdev->devid_source > 0) {
208 ptr[0] = 9;
209 ptr[1] = EIR_DEVICE_ID;
210
211 put_unaligned_le16(hdev->devid_source, ptr + 2);
212 put_unaligned_le16(hdev->devid_vendor, ptr + 4);
213 put_unaligned_le16(hdev->devid_product, ptr + 6);
214 put_unaligned_le16(hdev->devid_version, ptr + 8);
215
216 ptr += 10;
217 }
218
219 ptr = create_uuid16_list(hdev, ptr, HCI_MAX_EIR_LENGTH - (ptr - data));
220 ptr = create_uuid32_list(hdev, ptr, HCI_MAX_EIR_LENGTH - (ptr - data));
221 ptr = create_uuid128_list(hdev, ptr, HCI_MAX_EIR_LENGTH - (ptr - data));
222 }
223
eir_create_per_adv_data(struct hci_dev * hdev,u8 instance,u8 * ptr)224 u8 eir_create_per_adv_data(struct hci_dev *hdev, u8 instance, u8 *ptr)
225 {
226 struct adv_info *adv = NULL;
227 u8 ad_len = 0;
228
229 /* Return 0 when the current instance identifier is invalid. */
230 if (instance) {
231 adv = hci_find_adv_instance(hdev, instance);
232 if (!adv)
233 return 0;
234 }
235
236 if (adv) {
237 memcpy(ptr, adv->per_adv_data, adv->per_adv_data_len);
238 ad_len += adv->per_adv_data_len;
239 ptr += adv->per_adv_data_len;
240 }
241
242 return ad_len;
243 }
244
eir_create_adv_data(struct hci_dev * hdev,u8 instance,u8 * ptr)245 u8 eir_create_adv_data(struct hci_dev *hdev, u8 instance, u8 *ptr)
246 {
247 struct adv_info *adv = NULL;
248 u8 ad_len = 0, flags = 0;
249 u32 instance_flags;
250
251 /* Return 0 when the current instance identifier is invalid. */
252 if (instance) {
253 adv = hci_find_adv_instance(hdev, instance);
254 if (!adv)
255 return 0;
256 }
257
258 instance_flags = hci_adv_instance_flags(hdev, instance);
259
260 /* If instance already has the flags set skip adding it once
261 * again.
262 */
263 if (adv && eir_get_data(adv->adv_data, adv->adv_data_len, EIR_FLAGS,
264 NULL))
265 goto skip_flags;
266
267 /* The Add Advertising command allows userspace to set both the general
268 * and limited discoverable flags.
269 */
270 if (instance_flags & MGMT_ADV_FLAG_DISCOV)
271 flags |= LE_AD_GENERAL;
272
273 if (instance_flags & MGMT_ADV_FLAG_LIMITED_DISCOV)
274 flags |= LE_AD_LIMITED;
275
276 if (!hci_dev_test_flag(hdev, HCI_BREDR_ENABLED))
277 flags |= LE_AD_NO_BREDR;
278
279 if (flags || (instance_flags & MGMT_ADV_FLAG_MANAGED_FLAGS)) {
280 /* If a discovery flag wasn't provided, simply use the global
281 * settings.
282 */
283 if (!flags)
284 flags |= mgmt_get_adv_discov_flags(hdev);
285
286 /* If flags would still be empty, then there is no need to
287 * include the "Flags" AD field".
288 */
289 if (flags) {
290 ptr[0] = 0x02;
291 ptr[1] = EIR_FLAGS;
292 ptr[2] = flags;
293
294 ad_len += 3;
295 ptr += 3;
296 }
297 }
298
299 skip_flags:
300 if (adv) {
301 memcpy(ptr, adv->adv_data, adv->adv_data_len);
302 ad_len += adv->adv_data_len;
303 ptr += adv->adv_data_len;
304 }
305
306 if (instance_flags & MGMT_ADV_FLAG_TX_POWER) {
307 s8 adv_tx_power;
308
309 if (ext_adv_capable(hdev)) {
310 if (adv)
311 adv_tx_power = adv->tx_power;
312 else
313 adv_tx_power = hdev->adv_tx_power;
314 } else {
315 adv_tx_power = hdev->adv_tx_power;
316 }
317
318 /* Provide Tx Power only if we can provide a valid value for it */
319 if (adv_tx_power != HCI_TX_POWER_INVALID) {
320 ptr[0] = 0x02;
321 ptr[1] = EIR_TX_POWER;
322 ptr[2] = (u8)adv_tx_power;
323
324 ad_len += 3;
325 ptr += 3;
326 }
327 }
328
329 return ad_len;
330 }
331
create_default_scan_rsp(struct hci_dev * hdev,u8 * ptr)332 static u8 create_default_scan_rsp(struct hci_dev *hdev, u8 *ptr)
333 {
334 u8 scan_rsp_len = 0;
335
336 if (hdev->appearance)
337 scan_rsp_len = eir_append_appearance(hdev, ptr, scan_rsp_len);
338
339 return eir_append_local_name(hdev, ptr, scan_rsp_len);
340 }
341
eir_create_scan_rsp(struct hci_dev * hdev,u8 instance,u8 * ptr)342 u8 eir_create_scan_rsp(struct hci_dev *hdev, u8 instance, u8 *ptr)
343 {
344 struct adv_info *adv;
345 u8 scan_rsp_len = 0;
346
347 if (!instance)
348 return create_default_scan_rsp(hdev, ptr);
349
350 adv = hci_find_adv_instance(hdev, instance);
351 if (!adv)
352 return 0;
353
354 if ((adv->flags & MGMT_ADV_FLAG_APPEARANCE) && hdev->appearance)
355 scan_rsp_len = eir_append_appearance(hdev, ptr, scan_rsp_len);
356
357 memcpy(&ptr[scan_rsp_len], adv->scan_rsp_data, adv->scan_rsp_len);
358
359 scan_rsp_len += adv->scan_rsp_len;
360
361 if (adv->flags & MGMT_ADV_FLAG_LOCAL_NAME)
362 scan_rsp_len = eir_append_local_name(hdev, ptr, scan_rsp_len);
363
364 return scan_rsp_len;
365 }
366
eir_get_service_data(u8 * eir,size_t eir_len,u16 uuid,size_t * len)367 void *eir_get_service_data(u8 *eir, size_t eir_len, u16 uuid, size_t *len)
368 {
369 while ((eir = eir_get_data(eir, eir_len, EIR_SERVICE_DATA, len))) {
370 u16 value = get_unaligned_le16(eir);
371
372 if (uuid == value) {
373 if (len)
374 *len -= 2;
375 return &eir[2];
376 }
377
378 eir += *len;
379 eir_len -= *len;
380 }
381
382 return NULL;
383 }
384