GNU Linux-libre 6.9.2-gnu
[releases.git] / net / bluetooth / eir.c
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
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
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
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
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
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
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
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
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
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
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
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
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 }