Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | RFCOMM implementation for Linux Bluetooth stack (BlueZ). | |
3 | Copyright (C) 2002 Maxim Krasnyansky <maxk@qualcomm.com> | |
4 | Copyright (C) 2002 Marcel Holtmann <marcel@holtmann.org> | |
5 | ||
6 | This program is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License version 2 as | |
8 | published by the Free Software Foundation; | |
9 | ||
10 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS | |
11 | OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
12 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. | |
13 | IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY | |
14 | CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES | |
15 | WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN | |
16 | ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF | |
17 | OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | |
18 | ||
19 | ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS, | |
20 | COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS | |
21 | SOFTWARE IS DISCLAIMED. | |
22 | */ | |
23 | ||
24 | /* | |
25 | * RFCOMM TTY. | |
26 | * | |
27 | * $Id: tty.c,v 1.24 2002/10/03 01:54:38 holtmann Exp $ | |
28 | */ | |
29 | ||
30 | #include <linux/config.h> | |
31 | #include <linux/module.h> | |
32 | ||
33 | #include <linux/tty.h> | |
34 | #include <linux/tty_driver.h> | |
35 | #include <linux/tty_flip.h> | |
36 | ||
4fc268d2 | 37 | #include <linux/capability.h> |
1da177e4 LT |
38 | #include <linux/slab.h> |
39 | #include <linux/skbuff.h> | |
40 | ||
41 | #include <net/bluetooth/bluetooth.h> | |
42 | #include <net/bluetooth/rfcomm.h> | |
43 | ||
44 | #ifndef CONFIG_BT_RFCOMM_DEBUG | |
45 | #undef BT_DBG | |
46 | #define BT_DBG(D...) | |
47 | #endif | |
48 | ||
49 | #define RFCOMM_TTY_MAGIC 0x6d02 /* magic number for rfcomm struct */ | |
50 | #define RFCOMM_TTY_PORTS RFCOMM_MAX_DEV /* whole lotta rfcomm devices */ | |
51 | #define RFCOMM_TTY_MAJOR 216 /* device node major id of the usb/bluetooth.c driver */ | |
52 | #define RFCOMM_TTY_MINOR 0 | |
53 | ||
54 | static struct tty_driver *rfcomm_tty_driver; | |
55 | ||
56 | struct rfcomm_dev { | |
57 | struct list_head list; | |
58 | atomic_t refcnt; | |
59 | ||
60 | char name[12]; | |
61 | int id; | |
62 | unsigned long flags; | |
63 | int opened; | |
64 | int err; | |
65 | ||
66 | bdaddr_t src; | |
67 | bdaddr_t dst; | |
68 | u8 channel; | |
69 | ||
70 | uint modem_status; | |
71 | ||
72 | struct rfcomm_dlc *dlc; | |
73 | struct tty_struct *tty; | |
74 | wait_queue_head_t wait; | |
75 | struct tasklet_struct wakeup_task; | |
76 | ||
77 | atomic_t wmem_alloc; | |
78 | }; | |
79 | ||
80 | static LIST_HEAD(rfcomm_dev_list); | |
81 | static DEFINE_RWLOCK(rfcomm_dev_lock); | |
82 | ||
83 | static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb); | |
84 | static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err); | |
85 | static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig); | |
86 | ||
87 | static void rfcomm_tty_wakeup(unsigned long arg); | |
88 | ||
89 | /* ---- Device functions ---- */ | |
90 | static void rfcomm_dev_destruct(struct rfcomm_dev *dev) | |
91 | { | |
92 | struct rfcomm_dlc *dlc = dev->dlc; | |
93 | ||
94 | BT_DBG("dev %p dlc %p", dev, dlc); | |
95 | ||
96 | rfcomm_dlc_lock(dlc); | |
97 | /* Detach DLC if it's owned by this dev */ | |
98 | if (dlc->owner == dev) | |
99 | dlc->owner = NULL; | |
100 | rfcomm_dlc_unlock(dlc); | |
101 | ||
102 | rfcomm_dlc_put(dlc); | |
103 | ||
104 | tty_unregister_device(rfcomm_tty_driver, dev->id); | |
105 | ||
106 | /* Refcount should only hit zero when called from rfcomm_dev_del() | |
107 | which will have taken us off the list. Everything else are | |
108 | refcounting bugs. */ | |
109 | BUG_ON(!list_empty(&dev->list)); | |
110 | ||
111 | kfree(dev); | |
112 | ||
113 | /* It's safe to call module_put() here because socket still | |
114 | holds reference to this module. */ | |
115 | module_put(THIS_MODULE); | |
116 | } | |
117 | ||
118 | static inline void rfcomm_dev_hold(struct rfcomm_dev *dev) | |
119 | { | |
120 | atomic_inc(&dev->refcnt); | |
121 | } | |
122 | ||
123 | static inline void rfcomm_dev_put(struct rfcomm_dev *dev) | |
124 | { | |
125 | /* The reason this isn't actually a race, as you no | |
126 | doubt have a little voice screaming at you in your | |
127 | head, is that the refcount should never actually | |
128 | reach zero unless the device has already been taken | |
129 | off the list, in rfcomm_dev_del(). And if that's not | |
130 | true, we'll hit the BUG() in rfcomm_dev_destruct() | |
131 | anyway. */ | |
132 | if (atomic_dec_and_test(&dev->refcnt)) | |
133 | rfcomm_dev_destruct(dev); | |
134 | } | |
135 | ||
136 | static struct rfcomm_dev *__rfcomm_dev_get(int id) | |
137 | { | |
138 | struct rfcomm_dev *dev; | |
139 | struct list_head *p; | |
140 | ||
141 | list_for_each(p, &rfcomm_dev_list) { | |
142 | dev = list_entry(p, struct rfcomm_dev, list); | |
143 | if (dev->id == id) | |
144 | return dev; | |
145 | } | |
146 | ||
147 | return NULL; | |
148 | } | |
149 | ||
150 | static inline struct rfcomm_dev *rfcomm_dev_get(int id) | |
151 | { | |
152 | struct rfcomm_dev *dev; | |
153 | ||
154 | read_lock(&rfcomm_dev_lock); | |
155 | ||
156 | dev = __rfcomm_dev_get(id); | |
157 | if (dev) | |
158 | rfcomm_dev_hold(dev); | |
159 | ||
160 | read_unlock(&rfcomm_dev_lock); | |
161 | ||
162 | return dev; | |
163 | } | |
164 | ||
165 | static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc) | |
166 | { | |
167 | struct rfcomm_dev *dev; | |
168 | struct list_head *head = &rfcomm_dev_list, *p; | |
169 | int err = 0; | |
170 | ||
171 | BT_DBG("id %d channel %d", req->dev_id, req->channel); | |
172 | ||
173 | dev = kmalloc(sizeof(struct rfcomm_dev), GFP_KERNEL); | |
174 | if (!dev) | |
175 | return -ENOMEM; | |
176 | memset(dev, 0, sizeof(struct rfcomm_dev)); | |
177 | ||
178 | write_lock_bh(&rfcomm_dev_lock); | |
179 | ||
180 | if (req->dev_id < 0) { | |
181 | dev->id = 0; | |
182 | ||
183 | list_for_each(p, &rfcomm_dev_list) { | |
184 | if (list_entry(p, struct rfcomm_dev, list)->id != dev->id) | |
185 | break; | |
186 | ||
187 | dev->id++; | |
188 | head = p; | |
189 | } | |
190 | } else { | |
191 | dev->id = req->dev_id; | |
192 | ||
193 | list_for_each(p, &rfcomm_dev_list) { | |
194 | struct rfcomm_dev *entry = list_entry(p, struct rfcomm_dev, list); | |
195 | ||
196 | if (entry->id == dev->id) { | |
197 | err = -EADDRINUSE; | |
198 | goto out; | |
199 | } | |
200 | ||
201 | if (entry->id > dev->id - 1) | |
202 | break; | |
203 | ||
204 | head = p; | |
205 | } | |
206 | } | |
207 | ||
208 | if ((dev->id < 0) || (dev->id > RFCOMM_MAX_DEV - 1)) { | |
209 | err = -ENFILE; | |
210 | goto out; | |
211 | } | |
212 | ||
213 | sprintf(dev->name, "rfcomm%d", dev->id); | |
214 | ||
215 | list_add(&dev->list, head); | |
216 | atomic_set(&dev->refcnt, 1); | |
217 | ||
218 | bacpy(&dev->src, &req->src); | |
219 | bacpy(&dev->dst, &req->dst); | |
220 | dev->channel = req->channel; | |
221 | ||
222 | dev->flags = req->flags & | |
223 | ((1 << RFCOMM_RELEASE_ONHUP) | (1 << RFCOMM_REUSE_DLC)); | |
224 | ||
225 | init_waitqueue_head(&dev->wait); | |
226 | tasklet_init(&dev->wakeup_task, rfcomm_tty_wakeup, (unsigned long) dev); | |
227 | ||
228 | rfcomm_dlc_lock(dlc); | |
229 | dlc->data_ready = rfcomm_dev_data_ready; | |
230 | dlc->state_change = rfcomm_dev_state_change; | |
231 | dlc->modem_status = rfcomm_dev_modem_status; | |
232 | ||
233 | dlc->owner = dev; | |
234 | dev->dlc = dlc; | |
235 | rfcomm_dlc_unlock(dlc); | |
236 | ||
237 | /* It's safe to call __module_get() here because socket already | |
238 | holds reference to this module. */ | |
239 | __module_get(THIS_MODULE); | |
240 | ||
241 | out: | |
242 | write_unlock_bh(&rfcomm_dev_lock); | |
243 | ||
244 | if (err) { | |
245 | kfree(dev); | |
246 | return err; | |
247 | } | |
248 | ||
249 | tty_register_device(rfcomm_tty_driver, dev->id, NULL); | |
250 | ||
251 | return dev->id; | |
252 | } | |
253 | ||
254 | static void rfcomm_dev_del(struct rfcomm_dev *dev) | |
255 | { | |
256 | BT_DBG("dev %p", dev); | |
257 | ||
258 | write_lock_bh(&rfcomm_dev_lock); | |
259 | list_del_init(&dev->list); | |
260 | write_unlock_bh(&rfcomm_dev_lock); | |
261 | ||
262 | rfcomm_dev_put(dev); | |
263 | } | |
264 | ||
265 | /* ---- Send buffer ---- */ | |
266 | static inline unsigned int rfcomm_room(struct rfcomm_dlc *dlc) | |
267 | { | |
268 | /* We can't let it be zero, because we don't get a callback | |
269 | when tx_credits becomes nonzero, hence we'd never wake up */ | |
270 | return dlc->mtu * (dlc->tx_credits?:1); | |
271 | } | |
272 | ||
273 | static void rfcomm_wfree(struct sk_buff *skb) | |
274 | { | |
275 | struct rfcomm_dev *dev = (void *) skb->sk; | |
276 | atomic_sub(skb->truesize, &dev->wmem_alloc); | |
277 | if (test_bit(RFCOMM_TTY_ATTACHED, &dev->flags)) | |
278 | tasklet_schedule(&dev->wakeup_task); | |
279 | rfcomm_dev_put(dev); | |
280 | } | |
281 | ||
282 | static inline void rfcomm_set_owner_w(struct sk_buff *skb, struct rfcomm_dev *dev) | |
283 | { | |
284 | rfcomm_dev_hold(dev); | |
285 | atomic_add(skb->truesize, &dev->wmem_alloc); | |
286 | skb->sk = (void *) dev; | |
287 | skb->destructor = rfcomm_wfree; | |
288 | } | |
289 | ||
dd0fc66f | 290 | static struct sk_buff *rfcomm_wmalloc(struct rfcomm_dev *dev, unsigned long size, gfp_t priority) |
1da177e4 LT |
291 | { |
292 | if (atomic_read(&dev->wmem_alloc) < rfcomm_room(dev->dlc)) { | |
293 | struct sk_buff *skb = alloc_skb(size, priority); | |
294 | if (skb) { | |
295 | rfcomm_set_owner_w(skb, dev); | |
296 | return skb; | |
297 | } | |
298 | } | |
299 | return NULL; | |
300 | } | |
301 | ||
302 | /* ---- Device IOCTLs ---- */ | |
303 | ||
304 | #define NOCAP_FLAGS ((1 << RFCOMM_REUSE_DLC) | (1 << RFCOMM_RELEASE_ONHUP)) | |
305 | ||
306 | static int rfcomm_create_dev(struct sock *sk, void __user *arg) | |
307 | { | |
308 | struct rfcomm_dev_req req; | |
309 | struct rfcomm_dlc *dlc; | |
310 | int id; | |
311 | ||
312 | if (copy_from_user(&req, arg, sizeof(req))) | |
313 | return -EFAULT; | |
314 | ||
315 | BT_DBG("sk %p dev_id %id flags 0x%x", sk, req.dev_id, req.flags); | |
316 | ||
317 | if (req.flags != NOCAP_FLAGS && !capable(CAP_NET_ADMIN)) | |
318 | return -EPERM; | |
319 | ||
320 | if (req.flags & (1 << RFCOMM_REUSE_DLC)) { | |
321 | /* Socket must be connected */ | |
322 | if (sk->sk_state != BT_CONNECTED) | |
323 | return -EBADFD; | |
324 | ||
325 | dlc = rfcomm_pi(sk)->dlc; | |
326 | rfcomm_dlc_hold(dlc); | |
327 | } else { | |
328 | dlc = rfcomm_dlc_alloc(GFP_KERNEL); | |
329 | if (!dlc) | |
330 | return -ENOMEM; | |
331 | } | |
332 | ||
333 | id = rfcomm_dev_add(&req, dlc); | |
334 | if (id < 0) { | |
335 | rfcomm_dlc_put(dlc); | |
336 | return id; | |
337 | } | |
338 | ||
339 | if (req.flags & (1 << RFCOMM_REUSE_DLC)) { | |
340 | /* DLC is now used by device. | |
341 | * Socket must be disconnected */ | |
342 | sk->sk_state = BT_CLOSED; | |
343 | } | |
344 | ||
345 | return id; | |
346 | } | |
347 | ||
348 | static int rfcomm_release_dev(void __user *arg) | |
349 | { | |
350 | struct rfcomm_dev_req req; | |
351 | struct rfcomm_dev *dev; | |
352 | ||
353 | if (copy_from_user(&req, arg, sizeof(req))) | |
354 | return -EFAULT; | |
355 | ||
356 | BT_DBG("dev_id %id flags 0x%x", req.dev_id, req.flags); | |
357 | ||
358 | if (!(dev = rfcomm_dev_get(req.dev_id))) | |
359 | return -ENODEV; | |
360 | ||
361 | if (dev->flags != NOCAP_FLAGS && !capable(CAP_NET_ADMIN)) { | |
362 | rfcomm_dev_put(dev); | |
363 | return -EPERM; | |
364 | } | |
365 | ||
366 | if (req.flags & (1 << RFCOMM_HANGUP_NOW)) | |
367 | rfcomm_dlc_close(dev->dlc, 0); | |
368 | ||
369 | rfcomm_dev_del(dev); | |
370 | rfcomm_dev_put(dev); | |
371 | return 0; | |
372 | } | |
373 | ||
374 | static int rfcomm_get_dev_list(void __user *arg) | |
375 | { | |
376 | struct rfcomm_dev_list_req *dl; | |
377 | struct rfcomm_dev_info *di; | |
378 | struct list_head *p; | |
379 | int n = 0, size, err; | |
380 | u16 dev_num; | |
381 | ||
382 | BT_DBG(""); | |
383 | ||
384 | if (get_user(dev_num, (u16 __user *) arg)) | |
385 | return -EFAULT; | |
386 | ||
387 | if (!dev_num || dev_num > (PAGE_SIZE * 4) / sizeof(*di)) | |
388 | return -EINVAL; | |
389 | ||
390 | size = sizeof(*dl) + dev_num * sizeof(*di); | |
391 | ||
392 | if (!(dl = kmalloc(size, GFP_KERNEL))) | |
393 | return -ENOMEM; | |
394 | ||
395 | di = dl->dev_info; | |
396 | ||
397 | read_lock_bh(&rfcomm_dev_lock); | |
398 | ||
399 | list_for_each(p, &rfcomm_dev_list) { | |
400 | struct rfcomm_dev *dev = list_entry(p, struct rfcomm_dev, list); | |
401 | (di + n)->id = dev->id; | |
402 | (di + n)->flags = dev->flags; | |
403 | (di + n)->state = dev->dlc->state; | |
404 | (di + n)->channel = dev->channel; | |
405 | bacpy(&(di + n)->src, &dev->src); | |
406 | bacpy(&(di + n)->dst, &dev->dst); | |
407 | if (++n >= dev_num) | |
408 | break; | |
409 | } | |
410 | ||
411 | read_unlock_bh(&rfcomm_dev_lock); | |
412 | ||
413 | dl->dev_num = n; | |
414 | size = sizeof(*dl) + n * sizeof(*di); | |
415 | ||
416 | err = copy_to_user(arg, dl, size); | |
417 | kfree(dl); | |
418 | ||
419 | return err ? -EFAULT : 0; | |
420 | } | |
421 | ||
422 | static int rfcomm_get_dev_info(void __user *arg) | |
423 | { | |
424 | struct rfcomm_dev *dev; | |
425 | struct rfcomm_dev_info di; | |
426 | int err = 0; | |
427 | ||
428 | BT_DBG(""); | |
429 | ||
430 | if (copy_from_user(&di, arg, sizeof(di))) | |
431 | return -EFAULT; | |
432 | ||
433 | if (!(dev = rfcomm_dev_get(di.id))) | |
434 | return -ENODEV; | |
435 | ||
436 | di.flags = dev->flags; | |
437 | di.channel = dev->channel; | |
438 | di.state = dev->dlc->state; | |
439 | bacpy(&di.src, &dev->src); | |
440 | bacpy(&di.dst, &dev->dst); | |
441 | ||
442 | if (copy_to_user(arg, &di, sizeof(di))) | |
443 | err = -EFAULT; | |
444 | ||
445 | rfcomm_dev_put(dev); | |
446 | return err; | |
447 | } | |
448 | ||
449 | int rfcomm_dev_ioctl(struct sock *sk, unsigned int cmd, void __user *arg) | |
450 | { | |
451 | BT_DBG("cmd %d arg %p", cmd, arg); | |
452 | ||
453 | switch (cmd) { | |
454 | case RFCOMMCREATEDEV: | |
455 | return rfcomm_create_dev(sk, arg); | |
456 | ||
457 | case RFCOMMRELEASEDEV: | |
458 | return rfcomm_release_dev(arg); | |
459 | ||
460 | case RFCOMMGETDEVLIST: | |
461 | return rfcomm_get_dev_list(arg); | |
462 | ||
463 | case RFCOMMGETDEVINFO: | |
464 | return rfcomm_get_dev_info(arg); | |
465 | } | |
466 | ||
467 | return -EINVAL; | |
468 | } | |
469 | ||
470 | /* ---- DLC callbacks ---- */ | |
471 | static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb) | |
472 | { | |
473 | struct rfcomm_dev *dev = dlc->owner; | |
474 | struct tty_struct *tty; | |
475 | ||
476 | if (!dev || !(tty = dev->tty)) { | |
477 | kfree_skb(skb); | |
478 | return; | |
479 | } | |
480 | ||
481 | BT_DBG("dlc %p tty %p len %d", dlc, tty, skb->len); | |
482 | ||
483 | if (test_bit(TTY_DONT_FLIP, &tty->flags)) { | |
33f0f88f AC |
484 | tty_buffer_request_room(tty, skb->len); |
485 | tty_insert_flip_string(tty, skb->data, skb->len); | |
1da177e4 LT |
486 | tty_flip_buffer_push(tty); |
487 | } else | |
488 | tty->ldisc.receive_buf(tty, skb->data, NULL, skb->len); | |
489 | ||
490 | kfree_skb(skb); | |
491 | } | |
492 | ||
493 | static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err) | |
494 | { | |
495 | struct rfcomm_dev *dev = dlc->owner; | |
496 | if (!dev) | |
497 | return; | |
498 | ||
499 | BT_DBG("dlc %p dev %p err %d", dlc, dev, err); | |
500 | ||
501 | dev->err = err; | |
502 | wake_up_interruptible(&dev->wait); | |
503 | ||
504 | if (dlc->state == BT_CLOSED) { | |
505 | if (!dev->tty) { | |
506 | if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) { | |
507 | rfcomm_dev_hold(dev); | |
508 | rfcomm_dev_del(dev); | |
509 | ||
510 | /* We have to drop DLC lock here, otherwise | |
511 | rfcomm_dev_put() will dead lock if it's | |
512 | the last reference. */ | |
513 | rfcomm_dlc_unlock(dlc); | |
514 | rfcomm_dev_put(dev); | |
515 | rfcomm_dlc_lock(dlc); | |
516 | } | |
517 | } else | |
518 | tty_hangup(dev->tty); | |
519 | } | |
520 | } | |
521 | ||
522 | static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig) | |
523 | { | |
524 | struct rfcomm_dev *dev = dlc->owner; | |
525 | if (!dev) | |
526 | return; | |