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
16u8 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
49u8 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
54u8 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
67static 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
109static 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
142static 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
175void 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
224u8 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
245u8 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
299skip_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
332static 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
342u8 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
367void *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