1 | /* |
2 | CMTP implementation for Linux Bluetooth stack (BlueZ). |
3 | Copyright (C) 2002-2003 Marcel Holtmann <marcel@holtmann.org> |
4 | |
5 | This program is free software; you can redistribute it and/or modify |
6 | it under the terms of the GNU General Public License version 2 as |
7 | published by the Free Software Foundation; |
8 | |
9 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
10 | OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
11 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. |
12 | IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY |
13 | CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES |
14 | WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
15 | ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
16 | OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
17 | |
18 | ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS, |
19 | COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS |
20 | SOFTWARE IS DISCLAIMED. |
21 | */ |
22 | |
23 | #include <linux/module.h> |
24 | |
25 | #include <linux/types.h> |
26 | #include <linux/errno.h> |
27 | #include <linux/kernel.h> |
28 | #include <linux/sched.h> |
29 | #include <linux/slab.h> |
30 | #include <linux/poll.h> |
31 | #include <linux/fcntl.h> |
32 | #include <linux/freezer.h> |
33 | #include <linux/skbuff.h> |
34 | #include <linux/socket.h> |
35 | #include <linux/ioctl.h> |
36 | #include <linux/file.h> |
37 | #include <linux/init.h> |
38 | #include <linux/kthread.h> |
39 | #include <net/sock.h> |
40 | |
41 | #include <linux/isdn/capilli.h> |
42 | |
43 | #include <net/bluetooth/bluetooth.h> |
44 | #include <net/bluetooth/l2cap.h> |
45 | |
46 | #include "cmtp.h" |
47 | |
48 | #define VERSION "1.0" |
49 | |
50 | static DECLARE_RWSEM(cmtp_session_sem); |
51 | static LIST_HEAD(cmtp_session_list); |
52 | |
53 | static struct cmtp_session *__cmtp_get_session(bdaddr_t *bdaddr) |
54 | { |
55 | struct cmtp_session *session; |
56 | |
57 | BT_DBG("" ); |
58 | |
59 | list_for_each_entry(session, &cmtp_session_list, list) |
60 | if (!bacmp(ba1: bdaddr, ba2: &session->bdaddr)) |
61 | return session; |
62 | |
63 | return NULL; |
64 | } |
65 | |
66 | static void __cmtp_link_session(struct cmtp_session *session) |
67 | { |
68 | list_add(new: &session->list, head: &cmtp_session_list); |
69 | } |
70 | |
71 | static void __cmtp_unlink_session(struct cmtp_session *session) |
72 | { |
73 | list_del(entry: &session->list); |
74 | } |
75 | |
76 | static void __cmtp_copy_session(struct cmtp_session *session, struct cmtp_conninfo *ci) |
77 | { |
78 | u32 valid_flags = BIT(CMTP_LOOPBACK); |
79 | memset(ci, 0, sizeof(*ci)); |
80 | bacpy(dst: &ci->bdaddr, src: &session->bdaddr); |
81 | |
82 | ci->flags = session->flags & valid_flags; |
83 | ci->state = session->state; |
84 | |
85 | ci->num = session->num; |
86 | } |
87 | |
88 | |
89 | static inline int cmtp_alloc_block_id(struct cmtp_session *session) |
90 | { |
91 | int i, id = -1; |
92 | |
93 | for (i = 0; i < 16; i++) |
94 | if (!test_and_set_bit(nr: i, addr: &session->blockids)) { |
95 | id = i; |
96 | break; |
97 | } |
98 | |
99 | return id; |
100 | } |
101 | |
102 | static inline void cmtp_free_block_id(struct cmtp_session *session, int id) |
103 | { |
104 | clear_bit(nr: id, addr: &session->blockids); |
105 | } |
106 | |
107 | static inline void cmtp_add_msgpart(struct cmtp_session *session, int id, const unsigned char *buf, int count) |
108 | { |
109 | struct sk_buff *skb = session->reassembly[id], *nskb; |
110 | int size; |
111 | |
112 | BT_DBG("session %p buf %p count %d" , session, buf, count); |
113 | |
114 | size = (skb) ? skb->len + count : count; |
115 | |
116 | nskb = alloc_skb(size, GFP_ATOMIC); |
117 | if (!nskb) { |
118 | BT_ERR("Can't allocate memory for CAPI message" ); |
119 | return; |
120 | } |
121 | |
122 | if (skb && (skb->len > 0)) |
123 | skb_copy_from_linear_data(skb, to: skb_put(skb: nskb, len: skb->len), len: skb->len); |
124 | |
125 | skb_put_data(skb: nskb, data: buf, len: count); |
126 | |
127 | session->reassembly[id] = nskb; |
128 | |
129 | kfree_skb(skb); |
130 | } |
131 | |
132 | static inline int cmtp_recv_frame(struct cmtp_session *session, struct sk_buff *skb) |
133 | { |
134 | __u8 hdr, hdrlen, id; |
135 | __u16 len; |
136 | |
137 | BT_DBG("session %p skb %p len %d" , session, skb, skb->len); |
138 | |
139 | while (skb->len > 0) { |
140 | hdr = skb->data[0]; |
141 | |
142 | switch (hdr & 0xc0) { |
143 | case 0x40: |
144 | hdrlen = 2; |
145 | len = skb->data[1]; |
146 | break; |
147 | case 0x80: |
148 | hdrlen = 3; |
149 | len = skb->data[1] | (skb->data[2] << 8); |
150 | break; |
151 | default: |
152 | hdrlen = 1; |
153 | len = 0; |
154 | break; |
155 | } |
156 | |
157 | id = (hdr & 0x3c) >> 2; |
158 | |
159 | BT_DBG("hdr 0x%02x hdrlen %d len %d id %d" , hdr, hdrlen, len, id); |
160 | |
161 | if (hdrlen + len > skb->len) { |
162 | BT_ERR("Wrong size or header information in CMTP frame" ); |
163 | break; |
164 | } |
165 | |
166 | if (len == 0) { |
167 | skb_pull(skb, len: hdrlen); |
168 | continue; |
169 | } |
170 | |
171 | switch (hdr & 0x03) { |
172 | case 0x00: |
173 | cmtp_add_msgpart(session, id, buf: skb->data + hdrlen, count: len); |
174 | cmtp_recv_capimsg(session, skb: session->reassembly[id]); |
175 | session->reassembly[id] = NULL; |
176 | break; |
177 | case 0x01: |
178 | cmtp_add_msgpart(session, id, buf: skb->data + hdrlen, count: len); |
179 | break; |
180 | default: |
181 | kfree_skb(skb: session->reassembly[id]); |
182 | session->reassembly[id] = NULL; |
183 | break; |
184 | } |
185 | |
186 | skb_pull(skb, len: hdrlen + len); |
187 | } |
188 | |
189 | kfree_skb(skb); |
190 | return 0; |
191 | } |
192 | |
193 | static int cmtp_send_frame(struct cmtp_session *session, unsigned char *data, int len) |
194 | { |
195 | struct socket *sock = session->sock; |
196 | struct kvec iv = { data, len }; |
197 | struct msghdr msg; |
198 | |
199 | BT_DBG("session %p data %p len %d" , session, data, len); |
200 | |
201 | if (!len) |
202 | return 0; |
203 | |
204 | memset(&msg, 0, sizeof(msg)); |
205 | |
206 | return kernel_sendmsg(sock, msg: &msg, vec: &iv, num: 1, len); |
207 | } |
208 | |
209 | static void cmtp_process_transmit(struct cmtp_session *session) |
210 | { |
211 | struct sk_buff *skb, *nskb; |
212 | unsigned char *hdr; |
213 | unsigned int size, tail; |
214 | |
215 | BT_DBG("session %p" , session); |
216 | |
217 | nskb = alloc_skb(size: session->mtu, GFP_ATOMIC); |
218 | if (!nskb) { |
219 | BT_ERR("Can't allocate memory for new frame" ); |
220 | return; |
221 | } |
222 | |
223 | while ((skb = skb_dequeue(list: &session->transmit))) { |
224 | struct cmtp_scb *scb = (void *) skb->cb; |
225 | |
226 | tail = session->mtu - nskb->len; |
227 | if (tail < 5) { |
228 | cmtp_send_frame(session, data: nskb->data, len: nskb->len); |
229 | skb_trim(skb: nskb, len: 0); |
230 | tail = session->mtu; |
231 | } |
232 | |
233 | size = min_t(uint, ((tail < 258) ? (tail - 2) : (tail - 3)), skb->len); |
234 | |
235 | if (scb->id < 0) { |
236 | scb->id = cmtp_alloc_block_id(session); |
237 | if (scb->id < 0) { |
238 | skb_queue_head(list: &session->transmit, newsk: skb); |
239 | break; |
240 | } |
241 | } |
242 | |
243 | if (size < 256) { |
244 | hdr = skb_put(skb: nskb, len: 2); |
245 | hdr[0] = 0x40 |
246 | | ((scb->id << 2) & 0x3c) |
247 | | ((skb->len == size) ? 0x00 : 0x01); |
248 | hdr[1] = size; |
249 | } else { |
250 | hdr = skb_put(skb: nskb, len: 3); |
251 | hdr[0] = 0x80 |
252 | | ((scb->id << 2) & 0x3c) |
253 | | ((skb->len == size) ? 0x00 : 0x01); |
254 | hdr[1] = size & 0xff; |
255 | hdr[2] = size >> 8; |
256 | } |
257 | |
258 | skb_copy_from_linear_data(skb, to: skb_put(skb: nskb, len: size), len: size); |
259 | skb_pull(skb, len: size); |
260 | |
261 | if (skb->len > 0) { |
262 | skb_queue_head(list: &session->transmit, newsk: skb); |
263 | } else { |
264 | cmtp_free_block_id(session, id: scb->id); |
265 | if (scb->data) { |
266 | cmtp_send_frame(session, data: nskb->data, len: nskb->len); |
267 | skb_trim(skb: nskb, len: 0); |
268 | } |
269 | kfree_skb(skb); |
270 | } |
271 | } |
272 | |
273 | cmtp_send_frame(session, data: nskb->data, len: nskb->len); |
274 | |
275 | kfree_skb(skb: nskb); |
276 | } |
277 | |
278 | static int cmtp_session(void *arg) |
279 | { |
280 | struct cmtp_session *session = arg; |
281 | struct sock *sk = session->sock->sk; |
282 | struct sk_buff *skb; |
283 | DEFINE_WAIT_FUNC(wait, woken_wake_function); |
284 | |
285 | BT_DBG("session %p" , session); |
286 | |
287 | set_user_nice(current, nice: -15); |
288 | |
289 | add_wait_queue(wq_head: sk_sleep(sk), wq_entry: &wait); |
290 | while (1) { |
291 | if (atomic_read(v: &session->terminate)) |
292 | break; |
293 | if (sk->sk_state != BT_CONNECTED) |
294 | break; |
295 | |
296 | while ((skb = skb_dequeue(list: &sk->sk_receive_queue))) { |
297 | skb_orphan(skb); |
298 | if (!skb_linearize(skb)) |
299 | cmtp_recv_frame(session, skb); |
300 | else |
301 | kfree_skb(skb); |
302 | } |
303 | |
304 | cmtp_process_transmit(session); |
305 | |
306 | /* |
307 | * wait_woken() performs the necessary memory barriers |
308 | * for us; see the header comment for this primitive. |
309 | */ |
310 | wait_woken(wq_entry: &wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
311 | } |
312 | remove_wait_queue(wq_head: sk_sleep(sk), wq_entry: &wait); |
313 | |
314 | down_write(sem: &cmtp_session_sem); |
315 | |
316 | if (!(session->flags & BIT(CMTP_LOOPBACK))) |
317 | cmtp_detach_device(session); |
318 | |
319 | fput(session->sock->file); |
320 | |
321 | __cmtp_unlink_session(session); |
322 | |
323 | up_write(sem: &cmtp_session_sem); |
324 | |
325 | kfree(objp: session); |
326 | module_put_and_kthread_exit(0); |
327 | return 0; |
328 | } |
329 | |
330 | int cmtp_add_connection(struct cmtp_connadd_req *req, struct socket *sock) |
331 | { |
332 | u32 valid_flags = BIT(CMTP_LOOPBACK); |
333 | struct cmtp_session *session, *s; |
334 | int i, err; |
335 | |
336 | BT_DBG("" ); |
337 | |
338 | if (!l2cap_is_socket(sock)) |
339 | return -EBADFD; |
340 | |
341 | if (req->flags & ~valid_flags) |
342 | return -EINVAL; |
343 | |
344 | session = kzalloc(size: sizeof(struct cmtp_session), GFP_KERNEL); |
345 | if (!session) |
346 | return -ENOMEM; |
347 | |
348 | down_write(sem: &cmtp_session_sem); |
349 | |
350 | s = __cmtp_get_session(bdaddr: &l2cap_pi(sock->sk)->chan->dst); |
351 | if (s && s->state == BT_CONNECTED) { |
352 | err = -EEXIST; |
353 | goto failed; |
354 | } |
355 | |
356 | bacpy(dst: &session->bdaddr, src: &l2cap_pi(sock->sk)->chan->dst); |
357 | |
358 | session->mtu = min_t(uint, l2cap_pi(sock->sk)->chan->omtu, |
359 | l2cap_pi(sock->sk)->chan->imtu); |
360 | |
361 | BT_DBG("mtu %d" , session->mtu); |
362 | |
363 | sprintf(buf: session->name, fmt: "%pMR" , &session->bdaddr); |
364 | |
365 | session->sock = sock; |
366 | session->state = BT_CONFIG; |
367 | |
368 | init_waitqueue_head(&session->wait); |
369 | |
370 | session->msgnum = CMTP_INITIAL_MSGNUM; |
371 | |
372 | INIT_LIST_HEAD(list: &session->applications); |
373 | |
374 | skb_queue_head_init(list: &session->transmit); |
375 | |
376 | for (i = 0; i < 16; i++) |
377 | session->reassembly[i] = NULL; |
378 | |
379 | session->flags = req->flags; |
380 | |
381 | __cmtp_link_session(session); |
382 | |
383 | __module_get(THIS_MODULE); |
384 | session->task = kthread_run(cmtp_session, session, "kcmtpd_ctr_%d" , |
385 | session->num); |
386 | if (IS_ERR(ptr: session->task)) { |
387 | module_put(THIS_MODULE); |
388 | err = PTR_ERR(ptr: session->task); |
389 | goto unlink; |
390 | } |
391 | |
392 | if (!(session->flags & BIT(CMTP_LOOPBACK))) { |
393 | err = cmtp_attach_device(session); |
394 | if (err < 0) { |
395 | /* Caller will call fput in case of failure, and so |
396 | * will cmtp_session kthread. |
397 | */ |
398 | get_file(f: session->sock->file); |
399 | |
400 | atomic_inc(v: &session->terminate); |
401 | wake_up_interruptible(sk_sleep(session->sock->sk)); |
402 | up_write(sem: &cmtp_session_sem); |
403 | return err; |
404 | } |
405 | } |
406 | |
407 | up_write(sem: &cmtp_session_sem); |
408 | return 0; |
409 | |
410 | unlink: |
411 | __cmtp_unlink_session(session); |
412 | |
413 | failed: |
414 | up_write(sem: &cmtp_session_sem); |
415 | kfree(objp: session); |
416 | return err; |
417 | } |
418 | |
419 | int cmtp_del_connection(struct cmtp_conndel_req *req) |
420 | { |
421 | u32 valid_flags = 0; |
422 | struct cmtp_session *session; |
423 | int err = 0; |
424 | |
425 | BT_DBG("" ); |
426 | |
427 | if (req->flags & ~valid_flags) |
428 | return -EINVAL; |
429 | |
430 | down_read(sem: &cmtp_session_sem); |
431 | |
432 | session = __cmtp_get_session(bdaddr: &req->bdaddr); |
433 | if (session) { |
434 | /* Flush the transmit queue */ |
435 | skb_queue_purge(list: &session->transmit); |
436 | |
437 | /* Stop session thread */ |
438 | atomic_inc(v: &session->terminate); |
439 | |
440 | /* |
441 | * See the comment preceding the call to wait_woken() |
442 | * in cmtp_session(). |
443 | */ |
444 | wake_up_interruptible(sk_sleep(session->sock->sk)); |
445 | } else |
446 | err = -ENOENT; |
447 | |
448 | up_read(sem: &cmtp_session_sem); |
449 | return err; |
450 | } |
451 | |
452 | int cmtp_get_connlist(struct cmtp_connlist_req *req) |
453 | { |
454 | struct cmtp_session *session; |
455 | int err = 0, n = 0; |
456 | |
457 | BT_DBG("" ); |
458 | |
459 | down_read(sem: &cmtp_session_sem); |
460 | |
461 | list_for_each_entry(session, &cmtp_session_list, list) { |
462 | struct cmtp_conninfo ci; |
463 | |
464 | __cmtp_copy_session(session, ci: &ci); |
465 | |
466 | if (copy_to_user(to: req->ci, from: &ci, n: sizeof(ci))) { |
467 | err = -EFAULT; |
468 | break; |
469 | } |
470 | |
471 | if (++n >= req->cnum) |
472 | break; |
473 | |
474 | req->ci++; |
475 | } |
476 | req->cnum = n; |
477 | |
478 | up_read(sem: &cmtp_session_sem); |
479 | return err; |
480 | } |
481 | |
482 | int cmtp_get_conninfo(struct cmtp_conninfo *ci) |
483 | { |
484 | struct cmtp_session *session; |
485 | int err = 0; |
486 | |
487 | down_read(sem: &cmtp_session_sem); |
488 | |
489 | session = __cmtp_get_session(bdaddr: &ci->bdaddr); |
490 | if (session) |
491 | __cmtp_copy_session(session, ci); |
492 | else |
493 | err = -ENOENT; |
494 | |
495 | up_read(sem: &cmtp_session_sem); |
496 | return err; |
497 | } |
498 | |
499 | |
500 | static int __init cmtp_init(void) |
501 | { |
502 | BT_INFO("CMTP (CAPI Emulation) ver %s" , VERSION); |
503 | |
504 | return cmtp_init_sockets(); |
505 | } |
506 | |
507 | static void __exit cmtp_exit(void) |
508 | { |
509 | cmtp_cleanup_sockets(); |
510 | } |
511 | |
512 | module_init(cmtp_init); |
513 | module_exit(cmtp_exit); |
514 | |
515 | MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>" ); |
516 | MODULE_DESCRIPTION("Bluetooth CMTP ver " VERSION); |
517 | MODULE_VERSION(VERSION); |
518 | MODULE_LICENSE("GPL" ); |
519 | MODULE_ALIAS("bt-proto-5" ); |
520 | |