Commit | Line | Data |
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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 | ||
1da177e4 LT |
30 | #include <linux/module.h> |
31 | ||
32 | #include <linux/tty.h> | |
33 | #include <linux/tty_driver.h> | |
34 | #include <linux/tty_flip.h> | |
35 | ||
4fc268d2 | 36 | #include <linux/capability.h> |
1da177e4 LT |
37 | #include <linux/slab.h> |
38 | #include <linux/skbuff.h> | |
39 | ||
40 | #include <net/bluetooth/bluetooth.h> | |
41 | #include <net/bluetooth/rfcomm.h> | |
42 | ||
43 | #ifndef CONFIG_BT_RFCOMM_DEBUG | |
44 | #undef BT_DBG | |
45 | #define BT_DBG(D...) | |
46 | #endif | |
47 | ||
48 | #define RFCOMM_TTY_MAGIC 0x6d02 /* magic number for rfcomm struct */ | |
49 | #define RFCOMM_TTY_PORTS RFCOMM_MAX_DEV /* whole lotta rfcomm devices */ | |
50 | #define RFCOMM_TTY_MAJOR 216 /* device node major id of the usb/bluetooth.c driver */ | |
51 | #define RFCOMM_TTY_MINOR 0 | |
52 | ||
53 | static struct tty_driver *rfcomm_tty_driver; | |
54 | ||
55 | struct rfcomm_dev { | |
56 | struct list_head list; | |
57 | atomic_t refcnt; | |
58 | ||
59 | char name[12]; | |
60 | int id; | |
61 | unsigned long flags; | |
62 | int opened; | |
63 | int err; | |
64 | ||
65 | bdaddr_t src; | |
66 | bdaddr_t dst; | |
67 | u8 channel; | |
68 | ||
69 | uint modem_status; | |
70 | ||
71 | struct rfcomm_dlc *dlc; | |
72 | struct tty_struct *tty; | |
73 | wait_queue_head_t wait; | |
74 | struct tasklet_struct wakeup_task; | |
75 | ||
76 | atomic_t wmem_alloc; | |
77 | }; | |
78 | ||
79 | static LIST_HEAD(rfcomm_dev_list); | |
80 | static DEFINE_RWLOCK(rfcomm_dev_lock); | |
81 | ||
82 | static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb); | |
83 | static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err); | |
84 | static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig); | |
85 | ||
86 | static void rfcomm_tty_wakeup(unsigned long arg); | |
87 | ||
88 | /* ---- Device functions ---- */ | |
89 | static void rfcomm_dev_destruct(struct rfcomm_dev *dev) | |
90 | { | |
91 | struct rfcomm_dlc *dlc = dev->dlc; | |
92 | ||
93 | BT_DBG("dev %p dlc %p", dev, dlc); | |
94 | ||
95 | rfcomm_dlc_lock(dlc); | |
96 | /* Detach DLC if it's owned by this dev */ | |
97 | if (dlc->owner == dev) | |
98 | dlc->owner = NULL; | |
99 | rfcomm_dlc_unlock(dlc); | |
100 | ||
101 | rfcomm_dlc_put(dlc); | |
102 | ||
103 | tty_unregister_device(rfcomm_tty_driver, dev->id); | |
104 | ||
105 | /* Refcount should only hit zero when called from rfcomm_dev_del() | |
106 | which will have taken us off the list. Everything else are | |
107 | refcounting bugs. */ | |
108 | BUG_ON(!list_empty(&dev->list)); | |
109 | ||
110 | kfree(dev); | |
111 | ||
112 | /* It's safe to call module_put() here because socket still | |
113 | holds reference to this module. */ | |
114 | module_put(THIS_MODULE); | |
115 | } | |
116 | ||
117 | static inline void rfcomm_dev_hold(struct rfcomm_dev *dev) | |
118 | { | |
119 | atomic_inc(&dev->refcnt); | |
120 | } | |
121 | ||
122 | static inline void rfcomm_dev_put(struct rfcomm_dev *dev) | |
123 | { | |
124 | /* The reason this isn't actually a race, as you no | |
125 | doubt have a little voice screaming at you in your | |
126 | head, is that the refcount should never actually | |
127 | reach zero unless the device has already been taken | |
128 | off the list, in rfcomm_dev_del(). And if that's not | |
129 | true, we'll hit the BUG() in rfcomm_dev_destruct() | |
130 | anyway. */ | |
131 | if (atomic_dec_and_test(&dev->refcnt)) | |
132 | rfcomm_dev_destruct(dev); | |
133 | } | |
134 | ||
135 | static struct rfcomm_dev *__rfcomm_dev_get(int id) | |
136 | { | |
137 | struct rfcomm_dev *dev; | |
138 | struct list_head *p; | |
139 | ||
140 | list_for_each(p, &rfcomm_dev_list) { | |
141 | dev = list_entry(p, struct rfcomm_dev, list); | |
142 | if (dev->id == id) | |
143 | return dev; | |
144 | } | |
145 | ||
146 | return NULL; | |
147 | } | |
148 | ||
149 | static inline struct rfcomm_dev *rfcomm_dev_get(int id) | |
150 | { | |
151 | struct rfcomm_dev *dev; | |
152 | ||
153 | read_lock(&rfcomm_dev_lock); | |
154 | ||
155 | dev = __rfcomm_dev_get(id); | |
156 | if (dev) | |
157 | rfcomm_dev_hold(dev); | |
158 | ||
159 | read_unlock(&rfcomm_dev_lock); | |
160 | ||
161 | return dev; | |
162 | } | |
163 | ||
164 | static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc) | |
165 | { | |
166 | struct rfcomm_dev *dev; | |
167 | struct list_head *head = &rfcomm_dev_list, *p; | |
168 | int err = 0; | |
169 | ||
170 | BT_DBG("id %d channel %d", req->dev_id, req->channel); | |
171 | ||
25ea6db0 | 172 | dev = kzalloc(sizeof(struct rfcomm_dev), GFP_KERNEL); |
1da177e4 LT |
173 | if (!dev) |
174 | return -ENOMEM; | |
1da177e4 LT |
175 | |
176 | write_lock_bh(&rfcomm_dev_lock); | |
177 | ||
178 | if (req->dev_id < 0) { | |
179 | dev->id = 0; | |
180 | ||
181 | list_for_each(p, &rfcomm_dev_list) { | |
182 | if (list_entry(p, struct rfcomm_dev, list)->id != dev->id) | |
183 | break; | |
184 | ||
185 | dev->id++; | |
186 | head = p; | |
187 | } | |
188 | } else { | |
189 | dev->id = req->dev_id; | |
190 | ||
191 | list_for_each(p, &rfcomm_dev_list) { | |
192 | struct rfcomm_dev *entry = list_entry(p, struct rfcomm_dev, list); | |
193 | ||
194 | if (entry->id == dev->id) { | |
195 | err = -EADDRINUSE; | |
196 | goto out; | |
197 | } | |
198 | ||
199 | if (entry->id > dev->id - 1) | |
200 | break; | |
201 | ||
202 | head = p; | |
203 | } | |
204 | } | |
205 | ||
206 | if ((dev->id < 0) || (dev->id > RFCOMM_MAX_DEV - 1)) { | |
207 | err = -ENFILE; | |
208 | goto out; | |
209 | } | |
210 | ||
211 | sprintf(dev->name, "rfcomm%d", dev->id); | |
212 | ||
213 | list_add(&dev->list, head); | |
214 | atomic_set(&dev->refcnt, 1); | |
215 | ||
216 | bacpy(&dev->src, &req->src); | |
217 | bacpy(&dev->dst, &req->dst); | |
218 | dev->channel = req->channel; | |
219 | ||
220 | dev->flags = req->flags & | |
221 | ((1 << RFCOMM_RELEASE_ONHUP) | (1 << RFCOMM_REUSE_DLC)); | |
222 | ||
223 | init_waitqueue_head(&dev->wait); | |
224 | tasklet_init(&dev->wakeup_task, rfcomm_tty_wakeup, (unsigned long) dev); | |
225 | ||
226 | rfcomm_dlc_lock(dlc); | |
227 | dlc->data_ready = rfcomm_dev_data_ready; | |
228 | dlc->state_change = rfcomm_dev_state_change; | |
229 | dlc->modem_status = rfcomm_dev_modem_status; | |
230 | ||
231 | dlc->owner = dev; | |
232 | dev->dlc = dlc; | |
233 | rfcomm_dlc_unlock(dlc); | |
234 | ||
235 | /* It's safe to call __module_get() here because socket already | |
236 | holds reference to this module. */ | |
237 | __module_get(THIS_MODULE); | |
238 | ||
239 | out: | |
240 | write_unlock_bh(&rfcomm_dev_lock); | |
241 | ||
242 | if (err) { | |
243 | kfree(dev); | |
244 | return err; | |
245 | } | |
246 | ||
247 | tty_register_device(rfcomm_tty_driver, dev->id, NULL); | |
248 | ||
249 | return dev->id; | |
250 | } | |
251 | ||
252 | static void rfcomm_dev_del(struct rfcomm_dev *dev) | |
253 | { | |
254 | BT_DBG("dev %p", dev); | |
255 | ||
256 | write_lock_bh(&rfcomm_dev_lock); | |
257 | list_del_init(&dev->list); | |
258 | write_unlock_bh(&rfcomm_dev_lock); | |
259 | ||
260 | rfcomm_dev_put(dev); | |
261 | } | |
262 | ||
263 | /* ---- Send buffer ---- */ | |
264 | static inline unsigned int rfcomm_room(struct rfcomm_dlc *dlc) | |
265 | { | |
266 | /* We can't let it be zero, because we don't get a callback | |
267 | when tx_credits becomes nonzero, hence we'd never wake up */ | |
268 | return dlc->mtu * (dlc->tx_credits?:1); | |
269 | } | |
270 | ||
271 | static void rfcomm_wfree(struct sk_buff *skb) | |
272 | { | |
273 | struct rfcomm_dev *dev = (void *) skb->sk; | |
274 | atomic_sub(skb->truesize, &dev->wmem_alloc); | |
275 | if (test_bit(RFCOMM_TTY_ATTACHED, &dev->flags)) | |
276 | tasklet_schedule(&dev->wakeup_task); | |
277 | rfcomm_dev_put(dev); | |
278 | } | |
279 | ||
280 | static inline void rfcomm_set_owner_w(struct sk_buff *skb, struct rfcomm_dev *dev) | |
281 | { | |
282 | rfcomm_dev_hold(dev); | |
283 | atomic_add(skb->truesize, &dev->wmem_alloc); | |
284 | skb->sk = (void *) dev; | |
285 | skb->destructor = rfcomm_wfree; | |
286 | } | |
287 | ||
dd0fc66f | 288 | static struct sk_buff *rfcomm_wmalloc(struct rfcomm_dev *dev, unsigned long size, gfp_t priority) |
1da177e4 LT |
289 | { |
290 | if (atomic_read(&dev->wmem_alloc) < rfcomm_room(dev->dlc)) { | |
291 | struct sk_buff *skb = alloc_skb(size, priority); | |
292 | if (skb) { | |
293 | rfcomm_set_owner_w(skb, dev); | |
294 | return skb; | |
295 | } | |
296 | } | |
297 | return NULL; | |
298 | } | |
299 | ||
300 | /* ---- Device IOCTLs ---- */ | |
301 | ||
302 | #define NOCAP_FLAGS ((1 << RFCOMM_REUSE_DLC) | (1 << RFCOMM_RELEASE_ONHUP)) | |
303 | ||
304 | static int rfcomm_create_dev(struct sock *sk, void __user *arg) | |
305 | { | |
306 | struct rfcomm_dev_req req; | |
307 | struct rfcomm_dlc *dlc; | |
308 | int id; | |
309 | ||
310 | if (copy_from_user(&req, arg, sizeof(req))) | |
311 | return -EFAULT; | |
312 | ||
313 | BT_DBG("sk %p dev_id %id flags 0x%x", sk, req.dev_id, req.flags); | |
314 | ||
315 | if (req.flags != NOCAP_FLAGS && !capable(CAP_NET_ADMIN)) | |
316 | return -EPERM; | |
317 | ||
318 | if (req.flags & (1 << RFCOMM_REUSE_DLC)) { | |
319 | /* Socket must be connected */ | |
320 | if (sk->sk_state != BT_CONNECTED) | |
321 | return -EBADFD; | |
322 | ||
323 | dlc = rfcomm_pi(sk)->dlc; | |
324 | rfcomm_dlc_hold(dlc); | |
325 | } else { | |
326 | dlc = rfcomm_dlc_alloc(GFP_KERNEL); | |
327 | if (!dlc) | |
328 | return -ENOMEM; | |
329 | } | |
330 | ||
331 | id = rfcomm_dev_add(&req, dlc); | |
332 | if (id < 0) { | |
333 | rfcomm_dlc_put(dlc); | |
334 | return id; | |
335 | } | |
336 | ||
337 | if (req.flags & (1 << RFCOMM_REUSE_DLC)) { | |
338 | /* DLC is now used by device. | |
339 | * Socket must be disconnected */ | |
340 | sk->sk_state = BT_CLOSED; | |
341 | } | |
342 | ||
343 | return id; | |
344 | } | |
345 | ||
346 | static int rfcomm_release_dev(void __user *arg) | |
347 | { | |
348 | struct rfcomm_dev_req req; | |
349 | struct rfcomm_dev *dev; | |
350 | ||
351 | if (copy_from_user(&req, arg, sizeof(req))) | |
352 | return -EFAULT; | |
353 | ||
354 | BT_DBG("dev_id %id flags 0x%x", req.dev_id, req.flags); | |
355 | ||
356 | if (!(dev = rfcomm_dev_get(req.dev_id))) | |
357 | return -ENODEV; | |
358 | ||
359 | if (dev->flags != NOCAP_FLAGS && !capable(CAP_NET_ADMIN)) { | |
360 | rfcomm_dev_put(dev); | |
361 | return -EPERM; | |
362 | } | |
363 | ||
364 | if (req.flags & (1 << RFCOMM_HANGUP_NOW)) | |
365 | rfcomm_dlc_close(dev->dlc, 0); | |
366 | ||
367 | rfcomm_dev_del(dev); | |
368 | rfcomm_dev_put(dev); | |
369 | return 0; | |
370 | } | |
371 | ||
372 | static int rfcomm_get_dev_list(void __user *arg) | |
373 | { | |
374 | struct rfcomm_dev_list_req *dl; | |
375 | struct rfcomm_dev_info *di; | |
376 | struct list_head *p; | |
377 | int n = 0, size, err; | |
378 | u16 dev_num; | |
379 | ||
380 | BT_DBG(""); | |
381 | ||
382 | if (get_user(dev_num, (u16 __user *) arg)) | |
383 | return -EFAULT; | |
384 | ||
385 | if (!dev_num || dev_num > (PAGE_SIZE * 4) / sizeof(*di)) | |
386 | return -EINVAL; | |
387 | ||
388 | size = sizeof(*dl) + dev_num * sizeof(*di); | |
389 | ||
390 | if (!(dl = kmalloc(size, GFP_KERNEL))) | |
391 | return -ENOMEM; | |
392 | ||
393 | di = dl->dev_info; | |
394 | ||
395 | read_lock_bh(&rfcomm_dev_lock); | |
396 | ||
397 | list_for_each(p, &rfcomm_dev_list) { | |
398 | struct rfcomm_dev *dev = list_entry(p, struct rfcomm_dev, list); | |
399 | (di + n)->id = dev->id; | |
400 | (di + n)->flags = dev->flags; | |
401 | (di + n)->state = dev->dlc->state; | |
402 | (di + n)->channel = dev->channel; | |
403 | bacpy(&(di + n)->src, &dev->src); | |
404 | bacpy(&(di + n)->dst, &dev->dst); | |
405 | if (++n >= dev_num) | |
406 | break; | |
407 | } | |
408 | ||
409 | read_unlock_bh(&rfcomm_dev_lock); | |
410 | ||
411 | dl->dev_num = n; | |
412 | size = sizeof(*dl) + n * sizeof(*di); | |
413 | ||
414 | err = copy_to_user(arg, dl, size); | |
415 | kfree(dl); | |
416 | ||
417 | return err ? -EFAULT : 0; | |
418 | } | |
419 | ||
420 | static int rfcomm_get_dev_info(void __user *arg) | |
421 | { | |
422 | struct rfcomm_dev *dev; | |
423 | struct rfcomm_dev_info di; | |
424 | int err = 0; | |
425 | ||
426 | BT_DBG(""); | |
427 | ||
428 | if (copy_from_user(&di, arg, sizeof(di))) | |
429 | return -EFAULT; | |
430 | ||
431 | if (!(dev = rfcomm_dev_get(di.id))) | |
432 | return -ENODEV; | |
433 | ||
434 | di.flags = dev->flags; | |
435 | di.channel = dev->channel; | |
436 | di.state = dev->dlc->state; | |
437 | bacpy(&di.src, &dev->src); | |
438 | bacpy(&di.dst, &dev->dst); | |
439 | ||
440 | if (copy_to_user(arg, &di, sizeof(di))) | |
441 | err = -EFAULT; | |
442 | ||
443 | rfcomm_dev_put(dev); | |
444 | return err; | |
445 | } | |
446 | ||
447 | int rfcomm_dev_ioctl(struct sock *sk, unsigned int cmd, void __user *arg) | |
448 | { | |
449 | BT_DBG("cmd %d arg %p", cmd, arg); | |
450 | ||
451 | switch (cmd) { | |
452 | case RFCOMMCREATEDEV: | |
453 | return rfcomm_create_dev(sk, arg); | |
454 | ||
455 | case RFCOMMRELEASEDEV: | |
456 | return rfcomm_release_dev(arg); | |
457 | ||
458 | case RFCOMMGETDEVLIST: | |
459 | return rfcomm_get_dev_list(arg); | |
460 | ||
461 | case RFCOMMGETDEVINFO: | |
462 | return rfcomm_get_dev_info(arg); | |
463 | } | |
464 | ||
465 | return -EINVAL; | |
466 | } | |
467 | ||
468 | /* ---- DLC callbacks ---- */ | |
469 | static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb) | |
470 | { | |
471 | struct rfcomm_dev *dev = dlc->owner; | |
472 | struct tty_struct *tty; | |
473 | ||
474 | if (!dev || !(tty = dev->tty)) { | |
475 | kfree_skb(skb); | |
476 | return; | |
477 | } | |
478 | ||
479 | BT_DBG("dlc %p tty %p len %d", dlc, tty, skb->len); | |
480 | ||
817d6d3b PF |
481 | tty_insert_flip_string(tty, skb->data, skb->len); |
482 | tty_flip_buffer_push(tty); | |
1da177e4 LT |
483 | |
484 | kfree_skb(skb); | |
485 | } | |
486 | ||
487 | static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err) | |
488 | { | |
489 | struct rfcomm_dev *dev = dlc->owner; | |
490 | if (!dev) | |
491 | return; | |
492 | ||
493 | BT_DBG("dlc %p dev %p err %d", dlc, dev, err); | |
494 | ||
495 | dev->err = err; | |
496 | wake_up_interruptible(&dev->wait); | |
497 | ||
498 | if (dlc->state == BT_CLOSED) { | |
499 | if (!dev->tty) { | |
500 | if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) { | |
501 | rfcomm_dev_hold(dev); | |
502 | rfcomm_dev_del(dev); | |
503 | ||
504 | /* We have to drop DLC lock here, otherwise | |
505 | rfcomm_dev_put() will dead lock if it's | |
506 | the last reference. */ | |
507 | rfcomm_dlc_unlock(dlc); | |
508 | rfcomm_dev_put(dev); | |
509 | rfcomm_dlc_lock(dlc); | |
510 | } | |
511 | } else | |
512 | tty_hangup(dev->tty); | |
513 | } | |
514 | } | |
515 | ||
516 | static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig) | |
517 | { | |
518 | struct rfcomm_dev *dev = dlc->owner; | |
519 | if (!dev) | |
520 | return; |