Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
  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
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
/*
   CMTP implementation for Linux Bluetooth stack (BlueZ).
   Copyright (C) 2002-2003 Marcel Holtmann <marcel@holtmann.org>

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

   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
   IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
   CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

   ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
   COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
   SOFTWARE IS DISCLAIMED.
*/

#include <linux/module.h>

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/fcntl.h>
#include <linux/freezer.h>
#include <linux/skbuff.h>
#include <linux/socket.h>
#include <linux/ioctl.h>
#include <linux/file.h>
#include <linux/init.h>
#include <linux/kthread.h>
#include <net/sock.h>

#include <linux/isdn/capilli.h>

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/l2cap.h>

#include "cmtp.h"

#define VERSION "1.0"

static DECLARE_RWSEM(cmtp_session_sem);
static LIST_HEAD(cmtp_session_list);

static struct cmtp_session *__cmtp_get_session(bdaddr_t *bdaddr)
{
	struct cmtp_session *session;

	BT_DBG("");

	list_for_each_entry(session, &cmtp_session_list, list)
		if (!bacmp(bdaddr, &session->bdaddr))
			return session;

	return NULL;
}

static void __cmtp_link_session(struct cmtp_session *session)
{
	list_add(&session->list, &cmtp_session_list);
}

static void __cmtp_unlink_session(struct cmtp_session *session)
{
	list_del(&session->list);
}

static void __cmtp_copy_session(struct cmtp_session *session, struct cmtp_conninfo *ci)
{
	u32 valid_flags = BIT(CMTP_LOOPBACK);
	memset(ci, 0, sizeof(*ci));
	bacpy(&ci->bdaddr, &session->bdaddr);

	ci->flags = session->flags & valid_flags;
	ci->state = session->state;

	ci->num = session->num;
}


static inline int cmtp_alloc_block_id(struct cmtp_session *session)
{
	int i, id = -1;

	for (i = 0; i < 16; i++)
		if (!test_and_set_bit(i, &session->blockids)) {
			id = i;
			break;
		}

	return id;
}

static inline void cmtp_free_block_id(struct cmtp_session *session, int id)
{
	clear_bit(id, &session->blockids);
}

static inline void cmtp_add_msgpart(struct cmtp_session *session, int id, const unsigned char *buf, int count)
{
	struct sk_buff *skb = session->reassembly[id], *nskb;
	int size;

	BT_DBG("session %p buf %p count %d", session, buf, count);

	size = (skb) ? skb->len + count : count;

	nskb = alloc_skb(size, GFP_ATOMIC);
	if (!nskb) {
		BT_ERR("Can't allocate memory for CAPI message");
		return;
	}

	if (skb && (skb->len > 0))
		skb_copy_from_linear_data(skb, skb_put(nskb, skb->len), skb->len);

	skb_put_data(nskb, buf, count);

	session->reassembly[id] = nskb;

	kfree_skb(skb);
}

static inline int cmtp_recv_frame(struct cmtp_session *session, struct sk_buff *skb)
{
	__u8 hdr, hdrlen, id;
	__u16 len;

	BT_DBG("session %p skb %p len %d", session, skb, skb->len);

	while (skb->len > 0) {
		hdr = skb->data[0];

		switch (hdr & 0xc0) {
		case 0x40:
			hdrlen = 2;
			len = skb->data[1];
			break;
		case 0x80:
			hdrlen = 3;
			len = skb->data[1] | (skb->data[2] << 8);
			break;
		default:
			hdrlen = 1;
			len = 0;
			break;
		}

		id = (hdr & 0x3c) >> 2;

		BT_DBG("hdr 0x%02x hdrlen %d len %d id %d", hdr, hdrlen, len, id);

		if (hdrlen + len > skb->len) {
			BT_ERR("Wrong size or header information in CMTP frame");
			break;
		}

		if (len == 0) {
			skb_pull(skb, hdrlen);
			continue;
		}

		switch (hdr & 0x03) {
		case 0x00:
			cmtp_add_msgpart(session, id, skb->data + hdrlen, len);
			cmtp_recv_capimsg(session, session->reassembly[id]);
			session->reassembly[id] = NULL;
			break;
		case 0x01:
			cmtp_add_msgpart(session, id, skb->data + hdrlen, len);
			break;
		default:
			kfree_skb(session->reassembly[id]);
			session->reassembly[id] = NULL;
			break;
		}

		skb_pull(skb, hdrlen + len);
	}

	kfree_skb(skb);
	return 0;
}

static int cmtp_send_frame(struct cmtp_session *session, unsigned char *data, int len)
{
	struct socket *sock = session->sock;
	struct kvec iv = { data, len };
	struct msghdr msg;

	BT_DBG("session %p data %p len %d", session, data, len);

	if (!len)
		return 0;

	memset(&msg, 0, sizeof(msg));

	return kernel_sendmsg(sock, &msg, &iv, 1, len);
}

static void cmtp_process_transmit(struct cmtp_session *session)
{
	struct sk_buff *skb, *nskb;
	unsigned char *hdr;
	unsigned int size, tail;

	BT_DBG("session %p", session);

	nskb = alloc_skb(session->mtu, GFP_ATOMIC);
	if (!nskb) {
		BT_ERR("Can't allocate memory for new frame");
		return;
	}

	while ((skb = skb_dequeue(&session->transmit))) {
		struct cmtp_scb *scb = (void *) skb->cb;

		tail = session->mtu - nskb->len;
		if (tail < 5) {
			cmtp_send_frame(session, nskb->data, nskb->len);
			skb_trim(nskb, 0);
			tail = session->mtu;
		}

		size = min_t(uint, ((tail < 258) ? (tail - 2) : (tail - 3)), skb->len);

		if (scb->id < 0) {
			scb->id = cmtp_alloc_block_id(session);
			if (scb->id < 0) {
				skb_queue_head(&session->transmit, skb);
				break;
			}
		}

		if (size < 256) {
			hdr = skb_put(nskb, 2);
			hdr[0] = 0x40
				| ((scb->id << 2) & 0x3c)
				| ((skb->len == size) ? 0x00 : 0x01);
			hdr[1] = size;
		} else {
			hdr = skb_put(nskb, 3);
			hdr[0] = 0x80
				| ((scb->id << 2) & 0x3c)
				| ((skb->len == size) ? 0x00 : 0x01);
			hdr[1] = size & 0xff;
			hdr[2] = size >> 8;
		}

		skb_copy_from_linear_data(skb, skb_put(nskb, size), size);
		skb_pull(skb, size);

		if (skb->len > 0) {
			skb_queue_head(&session->transmit, skb);
		} else {
			cmtp_free_block_id(session, scb->id);
			if (scb->data) {
				cmtp_send_frame(session, nskb->data, nskb->len);
				skb_trim(nskb, 0);
			}
			kfree_skb(skb);
		}
	}

	cmtp_send_frame(session, nskb->data, nskb->len);

	kfree_skb(nskb);
}

static int cmtp_session(void *arg)
{
	struct cmtp_session *session = arg;
	struct sock *sk = session->sock->sk;
	struct sk_buff *skb;
	DEFINE_WAIT_FUNC(wait, woken_wake_function);

	BT_DBG("session %p", session);

	set_user_nice(current, -15);

	add_wait_queue(sk_sleep(sk), &wait);
	while (1) {
		if (atomic_read(&session->terminate))
			break;
		if (sk->sk_state != BT_CONNECTED)
			break;

		while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
			skb_orphan(skb);
			if (!skb_linearize(skb))
				cmtp_recv_frame(session, skb);
			else
				kfree_skb(skb);
		}

		cmtp_process_transmit(session);

		/*
		 * wait_woken() performs the necessary memory barriers
		 * for us; see the header comment for this primitive.
		 */
		wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
	}
	remove_wait_queue(sk_sleep(sk), &wait);

	down_write(&cmtp_session_sem);

	if (!(session->flags & BIT(CMTP_LOOPBACK)))
		cmtp_detach_device(session);

	fput(session->sock->file);

	__cmtp_unlink_session(session);

	up_write(&cmtp_session_sem);

	kfree(session);
	module_put_and_kthread_exit(0);
	return 0;
}

int cmtp_add_connection(struct cmtp_connadd_req *req, struct socket *sock)
{
	u32 valid_flags = BIT(CMTP_LOOPBACK);
	struct cmtp_session *session, *s;
	int i, err;

	BT_DBG("");

	if (!l2cap_is_socket(sock))
		return -EBADFD;

	if (req->flags & ~valid_flags)
		return -EINVAL;

	session = kzalloc(sizeof(struct cmtp_session), GFP_KERNEL);
	if (!session)
		return -ENOMEM;

	down_write(&cmtp_session_sem);

	s = __cmtp_get_session(&l2cap_pi(sock->sk)->chan->dst);
	if (s && s->state == BT_CONNECTED) {
		err = -EEXIST;
		goto failed;
	}

	bacpy(&session->bdaddr, &l2cap_pi(sock->sk)->chan->dst);

	session->mtu = min_t(uint, l2cap_pi(sock->sk)->chan->omtu,
					l2cap_pi(sock->sk)->chan->imtu);

	BT_DBG("mtu %d", session->mtu);

	sprintf(session->name, "%pMR", &session->bdaddr);

	session->sock  = sock;
	session->state = BT_CONFIG;

	init_waitqueue_head(&session->wait);

	session->msgnum = CMTP_INITIAL_MSGNUM;

	INIT_LIST_HEAD(&session->applications);

	skb_queue_head_init(&session->transmit);

	for (i = 0; i < 16; i++)
		session->reassembly[i] = NULL;

	session->flags = req->flags;

	__cmtp_link_session(session);

	__module_get(THIS_MODULE);
	session->task = kthread_run(cmtp_session, session, "kcmtpd_ctr_%d",
								session->num);
	if (IS_ERR(session->task)) {
		module_put(THIS_MODULE);
		err = PTR_ERR(session->task);
		goto unlink;
	}

	if (!(session->flags & BIT(CMTP_LOOPBACK))) {
		err = cmtp_attach_device(session);
		if (err < 0) {
			/* Caller will call fput in case of failure, and so
			 * will cmtp_session kthread.
			 */
			get_file(session->sock->file);

			atomic_inc(&session->terminate);
			wake_up_interruptible(sk_sleep(session->sock->sk));
			up_write(&cmtp_session_sem);
			return err;
		}
	}

	up_write(&cmtp_session_sem);
	return 0;

unlink:
	__cmtp_unlink_session(session);

failed:
	up_write(&cmtp_session_sem);
	kfree(session);
	return err;
}

int cmtp_del_connection(struct cmtp_conndel_req *req)
{
	u32 valid_flags = 0;
	struct cmtp_session *session;
	int err = 0;

	BT_DBG("");

	if (req->flags & ~valid_flags)
		return -EINVAL;

	down_read(&cmtp_session_sem);

	session = __cmtp_get_session(&req->bdaddr);
	if (session) {
		/* Flush the transmit queue */
		skb_queue_purge(&session->transmit);

		/* Stop session thread */
		atomic_inc(&session->terminate);

		/*
		 * See the comment preceding the call to wait_woken()
		 * in cmtp_session().
		 */
		wake_up_interruptible(sk_sleep(session->sock->sk));
	} else
		err = -ENOENT;

	up_read(&cmtp_session_sem);
	return err;
}

int cmtp_get_connlist(struct cmtp_connlist_req *req)
{
	struct cmtp_session *session;
	int err = 0, n = 0;

	BT_DBG("");

	down_read(&cmtp_session_sem);

	list_for_each_entry(session, &cmtp_session_list, list) {
		struct cmtp_conninfo ci;

		__cmtp_copy_session(session, &ci);

		if (copy_to_user(req->ci, &ci, sizeof(ci))) {
			err = -EFAULT;
			break;
		}

		if (++n >= req->cnum)
			break;

		req->ci++;
	}
	req->cnum = n;

	up_read(&cmtp_session_sem);
	return err;
}

int cmtp_get_conninfo(struct cmtp_conninfo *ci)
{
	struct cmtp_session *session;
	int err = 0;

	down_read(&cmtp_session_sem);

	session = __cmtp_get_session(&ci->bdaddr);
	if (session)
		__cmtp_copy_session(session, ci);
	else
		err = -ENOENT;

	up_read(&cmtp_session_sem);
	return err;
}


static int __init cmtp_init(void)
{
	BT_INFO("CMTP (CAPI Emulation) ver %s", VERSION);

	return cmtp_init_sockets();
}

static void __exit cmtp_exit(void)
{
	cmtp_cleanup_sockets();
}

module_init(cmtp_init);
module_exit(cmtp_exit);

MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
MODULE_DESCRIPTION("Bluetooth CMTP ver " VERSION);
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");
MODULE_ALIAS("bt-proto-5");