summaryrefslogtreecommitdiffstats
path: root/net/bluetooth/amp.c
blob: 016cdb66df6cfa5bfd4bb7fcd808a616e9fcde42 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
/*
   Copyright (c) 2011,2012 Intel Corp.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License version 2 and
   only version 2 as published by the Free Software Foundation.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
*/

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci.h>
#include <net/bluetooth/hci_core.h>
#include <crypto/hash.h>

#include "a2mp.h"
#include "amp.h"

/* Remote AMP Controllers interface */
void amp_ctrl_get(struct amp_ctrl *ctrl)
{
	BT_DBG("ctrl %p orig refcnt %d", ctrl,
	       atomic_read(&ctrl->kref.refcount));

	kref_get(&ctrl->kref);
}

static void amp_ctrl_destroy(struct kref *kref)
{
	struct amp_ctrl *ctrl = container_of(kref, struct amp_ctrl, kref);

	BT_DBG("ctrl %p", ctrl);

	kfree(ctrl->assoc);
	kfree(ctrl);
}

int amp_ctrl_put(struct amp_ctrl *ctrl)
{
	BT_DBG("ctrl %p orig refcnt %d", ctrl,
	       atomic_read(&ctrl->kref.refcount));

	return kref_put(&ctrl->kref, &amp_ctrl_destroy);
}

struct amp_ctrl *amp_ctrl_add(struct amp_mgr *mgr, u8 id)
{
	struct amp_ctrl *ctrl;

	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
	if (!ctrl)
		return NULL;

	kref_init(&ctrl->kref);
	ctrl->id = id;

	mutex_lock(&mgr->amp_ctrls_lock);
	list_add(&ctrl->list, &mgr->amp_ctrls);
	mutex_unlock(&mgr->amp_ctrls_lock);

	BT_DBG("mgr %p ctrl %p", mgr, ctrl);

	return ctrl;
}

void amp_ctrl_list_flush(struct amp_mgr *mgr)
{
	struct amp_ctrl *ctrl, *n;

	BT_DBG("mgr %p", mgr);

	mutex_lock(&mgr->amp_ctrls_lock);
	list_for_each_entry_safe(ctrl, n, &mgr->amp_ctrls, list) {
		list_del(&ctrl->list);
		amp_ctrl_put(ctrl);
	}
	mutex_unlock(&mgr->amp_ctrls_lock);
}

struct amp_ctrl *amp_ctrl_lookup(struct amp_mgr *mgr, u8 id)
{
	struct amp_ctrl *ctrl;

	BT_DBG("mgr %p id %d", mgr, id);

	mutex_lock(&mgr->amp_ctrls_lock);
	list_for_each_entry(ctrl, &mgr->amp_ctrls, list) {
		if (ctrl->id == id) {
			amp_ctrl_get(ctrl);
			mutex_unlock(&mgr->amp_ctrls_lock);
			return ctrl;
		}
	}
	mutex_unlock(&mgr->amp_ctrls_lock);

	return NULL;
}

/* Physical Link interface */
static u8 __next_handle(struct amp_mgr *mgr)
{
	if (++mgr->handle == 0)
		mgr->handle = 1;

	return mgr->handle;
}

struct hci_conn *phylink_add(struct hci_dev *hdev, struct amp_mgr *mgr,
			     u8 remote_id, bool out)
{
	bdaddr_t *dst = &mgr->l2cap_conn->hcon->dst;
	struct hci_conn *hcon;
	u8 role = out ? HCI_ROLE_MASTER : HCI_ROLE_SLAVE;

	hcon = hci_conn_add(hdev, AMP_LINK, dst, role);
	if (!hcon)
		return NULL;

	BT_DBG("hcon %p dst %pMR", hcon, dst);

	hcon->state = BT_CONNECT;
	hcon->attempt++;
	hcon->handle = __next_handle(mgr);
	hcon->remote_id = remote_id;
	hcon->amp_mgr = amp_mgr_get(mgr);

	return hcon;
}

/* AMP crypto key generation interface */
static int hmac_sha256(u8 *key, u8 ksize, char *plaintext, u8 psize, u8 *output)
{
	struct crypto_shash *tfm;
	int ret;

	if (!ksize)
		return -EINVAL;

	tfm = crypto_alloc_shash("hmac(sha256)", 0, 0);
	if (IS_ERR(tfm)) {
		BT_DBG("crypto_alloc_ahash failed: err %ld", PTR_ERR(tfm));
		return PTR_ERR(tfm);
	}

	ret = crypto_shash_setkey(tfm, key, ksize);
	if (ret) {
		BT_DBG("crypto_ahash_setkey failed: err %d", ret);
	} else {
		struct {
			struct shash_desc shash;
			char ctx[crypto_shash_descsize(tfm)];
		} desc;

		desc.shash.tfm = tfm;
		desc.shash.flags = CRYPTO_TFM_REQ_MAY_SLEEP;

		ret = crypto_shash_digest(&desc.shash, plaintext, psize,
					  output);
	}

	crypto_free_shash(tfm);
	return ret;
}

int phylink_gen_key(struct hci_conn *conn, u8 *data, u8 *len, u8 *type)
{
	struct hci_dev *hdev = conn->hdev;
	struct link_key *key;
	u8 keybuf[HCI_AMP_LINK_KEY_SIZE];
	u8 gamp_key[HCI_AMP_LINK_KEY_SIZE];
	int err;

	if (!hci_conn_check_link_mode(conn))
		return -EACCES;

	BT_DBG("conn %p key_type %d", conn, conn->key_type);

	/* Legacy key */
	if (conn->key_type < 3) {
		BT_ERR("Legacy key type %d", conn->key_type);
		return -EACCES;
	}

	*type = conn->key_type;
	*len = HCI_AMP_LINK_KEY_SIZE;

	key = hci_find_link_key(hdev, &conn->dst);
	if (!key) {
		BT_DBG("No Link key for conn %p dst %pMR", conn, &conn->dst);
		return -EACCES;
	}

	/* BR/EDR Link Key concatenated together with itself */
	memcpy(&keybuf[0], key->val, HCI_LINK_KEY_SIZE);
	memcpy(&keybuf[HCI_LINK_KEY_SIZE], key->val, HCI_LINK_KEY_SIZE);

	/* Derive Generic AMP Link Key (gamp) */
	err = hmac_sha256(keybuf, HCI_AMP_LINK_KEY_SIZE, "gamp", 4, gamp_key);
	if (err) {
		BT_ERR("Could not derive Generic AMP Key: err %d", err);
		return err;
	}

	if (conn->key_type == HCI_LK_DEBUG_COMBINATION) {
		BT_DBG("Use Generic AMP Key (gamp)");
		memcpy(data, gamp_key, HCI_AMP_LINK_KEY_SIZE);
		return err;
	}

	/* Derive Dedicated AMP Link Key: "802b" is 802.11 PAL keyID */
	return hmac_sha256(gamp_key, HCI_AMP_LINK_KEY_SIZE, "802b", 4, data);
}

void amp_read_loc_assoc_frag(struct hci_dev *hdev, u8 phy_handle)
{
	struct hci_cp_read_local_amp_assoc cp;
	struct amp_assoc *loc_assoc = &hdev->loc_assoc;

	BT_DBG("%s handle %d", hdev->name, phy_handle);

	cp.phy_handle = phy_handle;
	cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
	cp.len_so_far = cpu_to_le16(loc_assoc->offset);

	hci_send_cmd(hdev, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
}

void amp_read_loc_assoc(struct hci_dev *hdev, struct amp_mgr *mgr)
{
	struct hci_cp_read_local_amp_assoc cp;

	memset(&hdev->loc_assoc, 0, sizeof(struct amp_assoc));
	memset(&cp, 0, sizeof(cp));

	cp.max_len = cpu_to_le16(hdev->amp_assoc_size);

	set_bit(READ_LOC_AMP_ASSOC, &mgr->state);
	hci_send_cmd(hdev, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
}

void amp_read_loc_assoc_final_data(struct hci_dev *hdev,
				   struct hci_conn *hcon)
{
	struct hci_cp_read_local_amp_assoc cp;
	struct amp_mgr *mgr = hcon->amp_mgr;

	cp.phy_handle = hcon->handle;
	cp.len_so_far = cpu_to_le16(0);
	cp.max_len = cpu_to_le16(hdev->amp_assoc_size);

	set_bit(READ_LOC_AMP_ASSOC_FINAL, &mgr->state);

	/* Read Local AMP Assoc final link information data */
	hci_send_cmd(hdev, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
}

/* Write AMP Assoc data fragments, returns true with last fragment written*/
static bool amp_write_rem_assoc_frag(struct hci_dev *hdev,
				     struct hci_conn *hcon)
{
	struct hci_cp_write_remote_amp_assoc *cp;
	struct amp_mgr *mgr = hcon->amp_mgr;
	struct amp_ctrl *ctrl;
	u16 frag_len, len;

	ctrl = amp_ctrl_lookup(mgr, hcon->remote_id);
	if (!ctrl)
		return false;

	if (!ctrl->assoc_rem_len) {
		BT_DBG("all fragments are written");
		ctrl->assoc_rem_len = ctrl->assoc_len;
		ctrl->assoc_len_so_far = 0;

		amp_ctrl_put(ctrl);
		return true;
	}

	frag_len = min_t(u16, 248, ctrl->assoc_rem_len);
	len = frag_len + sizeof(*cp);

	cp = kzalloc(len, GFP_KERNEL);
	if (!cp) {
		amp_ctrl_put(ctrl);
		return false;
	}

	BT_DBG("hcon %p ctrl %p frag_len %u assoc_len %u rem_len %u",
	       hcon, ctrl, frag_len, ctrl->assoc_len, ctrl->assoc_rem_len);

	cp->phy_handle = hcon->handle;
	cp->len_so_far = cpu_to_le16(ctrl->assoc_len_so_far);
	cp->rem_len = cpu_to_le16(ctrl->assoc_rem_len);
	memcpy(cp->frag, ctrl->assoc, frag_len);

	ctrl->assoc_len_so_far += frag_len;
	ctrl->assoc_rem_len -= frag_len;

	amp_ctrl_put(ctrl);

	hci_send_cmd(hdev, HCI_OP_WRITE_REMOTE_AMP_ASSOC, len, cp);

	kfree(cp);

	return false;
}

void amp_write_rem_assoc_continue(struct hci_dev *hdev, u8 handle)
{
	struct hci_conn *hcon;

	BT_DBG("%s phy handle 0x%2.2x", hdev->name, handle);

	hcon = hci_conn_hash_lookup_handle(hdev, handle);
	if (!hcon)
		return;

	/* Send A2MP create phylink rsp when all fragments are written */
	if (amp_write_rem_assoc_frag(hdev, hcon))
		a2mp_send_create_phy_link_rsp(hdev, 0);
}

void amp_write_remote_assoc(struct hci_dev *hdev, u8 handle)
{
	struct hci_conn *hcon;

	BT_DBG("%s phy handle 0x%2.2x", hdev->name, handle);

	hcon = hci_conn_hash_lookup_handle(hdev, handle);
	if (!hcon)
		return;

	BT_DBG("%s phy handle 0x%2.2x hcon %p", hdev->name, handle, hcon);

	amp_write_rem_assoc_frag(hdev, hcon);
}

void amp_create_phylink(struct hci_dev *hdev, struct amp_mgr *mgr,
			struct hci_conn *hcon)
{
	struct hci_cp_create_phy_link cp;

	cp.phy_handle = hcon->handle;

	BT_DBG("%s hcon %p phy handle 0x%2.2x", hdev->name, hcon,
	       hcon->handle);

	if (phylink_gen_key(mgr->l2cap_conn->hcon, cp.key, &cp.key_len,
			    &cp.key_type)) {
		BT_DBG("Cannot create link key");
		return;
	}

	hci_send_cmd(hdev, HCI_OP_CREATE_PHY_LINK, sizeof(cp), &cp);
}

void amp_accept_phylink(struct hci_dev *hdev, struct amp_mgr *mgr,
			struct hci_conn *hcon)
{
	struct hci_cp_accept_phy_link cp;

	cp.phy_handle = hcon->handle;

	BT_DBG("%s hcon %p phy handle 0x%2.2x", hdev->name, hcon,
	       hcon->handle);

	if (phylink_gen_key(mgr->l2cap_conn->hcon, cp.key, &cp.key_len,
			    &cp.key_type)) {
		BT_DBG("Cannot create link key");
		return;
	}

	hci_send_cmd(hdev, HCI_OP_ACCEPT_PHY_LINK, sizeof(cp), &cp);
}

void amp_physical_cfm(struct hci_conn *bredr_hcon, struct hci_conn *hs_hcon)
{
	struct hci_dev *bredr_hdev = hci_dev_hold(bredr_hcon->hdev);
	struct amp_mgr *mgr = hs_hcon->amp_mgr;
	struct l2cap_chan *bredr_chan;

	BT_DBG("bredr_hcon %p hs_hcon %p mgr %p", bredr_hcon, hs_hcon, mgr);

	if (!bredr_hdev || !mgr || !mgr->bredr_chan)
		return;

	bredr_chan = mgr->bredr_chan;

	l2cap_chan_lock(bredr_chan);

	set_bit(FLAG_EFS_ENABLE, &bredr_chan->flags);
	bredr_chan->remote_amp_id = hs_hcon->remote_id;
	bredr_chan->local_amp_id = hs_hcon->hdev->id;
	bredr_chan->hs_hcon = hs_hcon;
	bredr_chan->conn->mtu = hs_hcon->hdev->block_mtu;

	__l2cap_physical_cfm(bredr_chan, 0);

	l2cap_chan_unlock(bredr_chan);

	hci_dev_put(bredr_hdev);
}

void amp_create_logical_link(struct l2cap_chan *chan)
{
	struct hci_conn *hs_hcon = chan->hs_hcon;
	struct hci_cp_create_accept_logical_link cp;
	struct hci_dev *hdev;

	BT_DBG("chan %p hs_hcon %p dst %pMR", chan, hs_hcon,
	       &chan->conn->hcon->dst);

	if (!hs_hcon)
		return;

	hdev = hci_dev_hold(chan->hs_hcon->hdev);
	if (!hdev)
		return;

	cp.phy_handle = hs_hcon->handle;

	cp.tx_flow_spec.id = chan->local_id;
	cp.tx_flow_spec.stype = chan->local_stype;
	cp.tx_flow_spec.msdu = cpu_to_le16(chan->local_msdu);
	cp.tx_flow_spec.sdu_itime = cpu_to_le32(chan->local_sdu_itime);
	cp.tx_flow_spec.acc_lat = cpu_to_le32(chan->local_acc_lat);
	cp.tx_flow_spec.flush_to = cpu_to_le32(chan->local_flush_to);

	cp.rx_flow_spec.id = chan->remote_id;
	cp.rx_flow_spec.stype = chan->remote_stype;
	cp.rx_flow_spec.msdu = cpu_to_le16(chan->remote_msdu);
	cp.rx_flow_spec.sdu_itime = cpu_to_le32(chan->remote_sdu_itime);
	cp.rx_flow_spec.acc_lat = cpu_to_le32(chan->remote_acc_lat);
	cp.rx_flow_spec.flush_to = cpu_to_le32(chan->remote_flush_to);

	if (hs_hcon->out)
		hci_send_cmd(hdev, HCI_OP_CREATE_LOGICAL_LINK, sizeof(cp),
			     &cp);
	else
		hci_send_cmd(hdev, HCI_OP_ACCEPT_LOGICAL_LINK, sizeof(cp),
			     &cp);

	hci_dev_put(hdev);
}

void amp_disconnect_logical_link(struct hci_chan *hchan)
{
	struct hci_conn *hcon = hchan->conn;
	struct hci_cp_disconn_logical_link cp;

	if (hcon->state != BT_CONNECTED) {
		BT_DBG("hchan %p not connected", hchan);
		return;
	}

	cp.log_handle = cpu_to_le16(hchan->handle);
	hci_send_cmd(hcon->hdev, HCI_OP_DISCONN_LOGICAL_LINK, sizeof(cp), &cp);
}

void amp_destroy_logical_link(struct hci_chan *hchan, u8 reason)
{
	BT_DBG("hchan %p", hchan);

	hci_chan_del(hchan);
}
OpenPOWER on IntegriCloud