xref: /linux/sound/core/seq/seq_clientmgr.c (revision 90e0d94d369d342e735a75174439482119b6c393)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  ALSA sequencer Client Manager
4  *  Copyright (c) 1998-2001 by Frank van de Pol <fvdpol@coil.demon.nl>
5  *                             Jaroslav Kysela <perex@perex.cz>
6  *                             Takashi Iwai <tiwai@suse.de>
7  */
8 
9 #include <linux/init.h>
10 #include <linux/export.h>
11 #include <linux/slab.h>
12 #include <sound/core.h>
13 #include <sound/minors.h>
14 #include <linux/kmod.h>
15 
16 #include <sound/seq_kernel.h>
17 #include "seq_clientmgr.h"
18 #include "seq_memory.h"
19 #include "seq_queue.h"
20 #include "seq_timer.h"
21 #include "seq_info.h"
22 #include "seq_system.h"
23 #include <sound/seq_device.h>
24 #ifdef CONFIG_COMPAT
25 #include <linux/compat.h>
26 #endif
27 
28 /* Client Manager
29 
30  * this module handles the connections of userland and kernel clients
31  *
32  */
33 
34 /*
35  * There are four ranges of client numbers (last two shared):
36  * 0..15: global clients
37  * 16..127: statically allocated client numbers for cards 0..27
38  * 128..191: dynamically allocated client numbers for cards 28..31
39  * 128..191: dynamically allocated client numbers for applications
40  */
41 
42 /* number of kernel non-card clients */
43 #define SNDRV_SEQ_GLOBAL_CLIENTS	16
44 /* clients per cards, for static clients */
45 #define SNDRV_SEQ_CLIENTS_PER_CARD	4
46 /* dynamically allocated client numbers (both kernel drivers and user space) */
47 #define SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN	128
48 
49 #define SNDRV_SEQ_LFLG_INPUT	0x0001
50 #define SNDRV_SEQ_LFLG_OUTPUT	0x0002
51 #define SNDRV_SEQ_LFLG_OPEN	(SNDRV_SEQ_LFLG_INPUT|SNDRV_SEQ_LFLG_OUTPUT)
52 
53 static DEFINE_SPINLOCK(clients_lock);
54 static DEFINE_MUTEX(register_mutex);
55 
56 /*
57  * client table
58  */
59 static char clienttablock[SNDRV_SEQ_MAX_CLIENTS];
60 static struct snd_seq_client *clienttab[SNDRV_SEQ_MAX_CLIENTS];
61 static struct snd_seq_usage client_usage;
62 
63 /*
64  * prototypes
65  */
66 static int bounce_error_event(struct snd_seq_client *client,
67 			      struct snd_seq_event *event,
68 			      int err, int atomic, int hop);
69 static int snd_seq_deliver_single_event(struct snd_seq_client *client,
70 					struct snd_seq_event *event,
71 					int filter, int atomic, int hop);
72 
73 /*
74  */
75 static inline unsigned short snd_seq_file_flags(struct file *file)
76 {
77         switch (file->f_mode & (FMODE_READ | FMODE_WRITE)) {
78         case FMODE_WRITE:
79                 return SNDRV_SEQ_LFLG_OUTPUT;
80         case FMODE_READ:
81                 return SNDRV_SEQ_LFLG_INPUT;
82         default:
83                 return SNDRV_SEQ_LFLG_OPEN;
84         }
85 }
86 
87 static inline int snd_seq_write_pool_allocated(struct snd_seq_client *client)
88 {
89 	return snd_seq_total_cells(client->pool) > 0;
90 }
91 
92 /* return pointer to client structure for specified id */
93 static struct snd_seq_client *clientptr(int clientid)
94 {
95 	if (clientid < 0 || clientid >= SNDRV_SEQ_MAX_CLIENTS) {
96 		pr_debug("ALSA: seq: oops. Trying to get pointer to client %d\n",
97 			   clientid);
98 		return NULL;
99 	}
100 	return clienttab[clientid];
101 }
102 
103 struct snd_seq_client *snd_seq_client_use_ptr(int clientid)
104 {
105 	unsigned long flags;
106 	struct snd_seq_client *client;
107 
108 	if (clientid < 0 || clientid >= SNDRV_SEQ_MAX_CLIENTS) {
109 		pr_debug("ALSA: seq: oops. Trying to get pointer to client %d\n",
110 			   clientid);
111 		return NULL;
112 	}
113 	spin_lock_irqsave(&clients_lock, flags);
114 	client = clientptr(clientid);
115 	if (client)
116 		goto __lock;
117 	if (clienttablock[clientid]) {
118 		spin_unlock_irqrestore(&clients_lock, flags);
119 		return NULL;
120 	}
121 	spin_unlock_irqrestore(&clients_lock, flags);
122 #ifdef CONFIG_MODULES
123 	if (!in_interrupt()) {
124 		static DECLARE_BITMAP(client_requested, SNDRV_SEQ_GLOBAL_CLIENTS);
125 		static DECLARE_BITMAP(card_requested, SNDRV_CARDS);
126 
127 		if (clientid < SNDRV_SEQ_GLOBAL_CLIENTS) {
128 			int idx;
129 
130 			if (!test_and_set_bit(clientid, client_requested)) {
131 				for (idx = 0; idx < 15; idx++) {
132 					if (seq_client_load[idx] < 0)
133 						break;
134 					if (seq_client_load[idx] == clientid) {
135 						request_module("snd-seq-client-%i",
136 							       clientid);
137 						break;
138 					}
139 				}
140 			}
141 		} else if (clientid < SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN) {
142 			int card = (clientid - SNDRV_SEQ_GLOBAL_CLIENTS) /
143 				SNDRV_SEQ_CLIENTS_PER_CARD;
144 			if (card < snd_ecards_limit) {
145 				if (!test_and_set_bit(card, card_requested))
146 					snd_request_card(card);
147 				snd_seq_device_load_drivers();
148 			}
149 		}
150 		spin_lock_irqsave(&clients_lock, flags);
151 		client = clientptr(clientid);
152 		if (client)
153 			goto __lock;
154 		spin_unlock_irqrestore(&clients_lock, flags);
155 	}
156 #endif
157 	return NULL;
158 
159       __lock:
160 	snd_use_lock_use(&client->use_lock);
161 	spin_unlock_irqrestore(&clients_lock, flags);
162 	return client;
163 }
164 
165 /* Take refcount and perform ioctl_mutex lock on the given client;
166  * used only for OSS sequencer
167  * Unlock via snd_seq_client_ioctl_unlock() below
168  */
169 bool snd_seq_client_ioctl_lock(int clientid)
170 {
171 	struct snd_seq_client *client;
172 
173 	client = snd_seq_client_use_ptr(clientid);
174 	if (!client)
175 		return false;
176 	mutex_lock(&client->ioctl_mutex);
177 	/* The client isn't unrefed here; see snd_seq_client_ioctl_unlock() */
178 	return true;
179 }
180 EXPORT_SYMBOL_GPL(snd_seq_client_ioctl_lock);
181 
182 /* Unlock and unref the given client; for OSS sequencer use only */
183 void snd_seq_client_ioctl_unlock(int clientid)
184 {
185 	struct snd_seq_client *client;
186 
187 	client = snd_seq_client_use_ptr(clientid);
188 	if (WARN_ON(!client))
189 		return;
190 	mutex_unlock(&client->ioctl_mutex);
191 	/* The doubly unrefs below are intentional; the first one releases the
192 	 * leftover from snd_seq_client_ioctl_lock() above, and the second one
193 	 * is for releasing snd_seq_client_use_ptr() in this function
194 	 */
195 	snd_seq_client_unlock(client);
196 	snd_seq_client_unlock(client);
197 }
198 EXPORT_SYMBOL_GPL(snd_seq_client_ioctl_unlock);
199 
200 static void usage_alloc(struct snd_seq_usage *res, int num)
201 {
202 	res->cur += num;
203 	if (res->cur > res->peak)
204 		res->peak = res->cur;
205 }
206 
207 static void usage_free(struct snd_seq_usage *res, int num)
208 {
209 	res->cur -= num;
210 }
211 
212 /* initialise data structures */
213 int __init client_init_data(void)
214 {
215 	/* zap out the client table */
216 	memset(&clienttablock, 0, sizeof(clienttablock));
217 	memset(&clienttab, 0, sizeof(clienttab));
218 	return 0;
219 }
220 
221 
222 static struct snd_seq_client *seq_create_client1(int client_index, int poolsize)
223 {
224 	int c;
225 	struct snd_seq_client *client;
226 
227 	/* init client data */
228 	client = kzalloc(sizeof(*client), GFP_KERNEL);
229 	if (client == NULL)
230 		return NULL;
231 	client->pool = snd_seq_pool_new(poolsize);
232 	if (client->pool == NULL) {
233 		kfree(client);
234 		return NULL;
235 	}
236 	client->type = NO_CLIENT;
237 	snd_use_lock_init(&client->use_lock);
238 	rwlock_init(&client->ports_lock);
239 	mutex_init(&client->ports_mutex);
240 	INIT_LIST_HEAD(&client->ports_list_head);
241 	mutex_init(&client->ioctl_mutex);
242 
243 	/* find free slot in the client table */
244 	spin_lock_irq(&clients_lock);
245 	if (client_index < 0) {
246 		for (c = SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN;
247 		     c < SNDRV_SEQ_MAX_CLIENTS;
248 		     c++) {
249 			if (clienttab[c] || clienttablock[c])
250 				continue;
251 			clienttab[client->number = c] = client;
252 			spin_unlock_irq(&clients_lock);
253 			return client;
254 		}
255 	} else {
256 		if (clienttab[client_index] == NULL && !clienttablock[client_index]) {
257 			clienttab[client->number = client_index] = client;
258 			spin_unlock_irq(&clients_lock);
259 			return client;
260 		}
261 	}
262 	spin_unlock_irq(&clients_lock);
263 	snd_seq_pool_delete(&client->pool);
264 	kfree(client);
265 	return NULL;	/* no free slot found or busy, return failure code */
266 }
267 
268 
269 static int seq_free_client1(struct snd_seq_client *client)
270 {
271 	if (!client)
272 		return 0;
273 	spin_lock_irq(&clients_lock);
274 	clienttablock[client->number] = 1;
275 	clienttab[client->number] = NULL;
276 	spin_unlock_irq(&clients_lock);
277 	snd_seq_delete_all_ports(client);
278 	snd_seq_queue_client_leave(client->number);
279 	snd_use_lock_sync(&client->use_lock);
280 	if (client->pool)
281 		snd_seq_pool_delete(&client->pool);
282 	spin_lock_irq(&clients_lock);
283 	clienttablock[client->number] = 0;
284 	spin_unlock_irq(&clients_lock);
285 	return 0;
286 }
287 
288 
289 static void seq_free_client(struct snd_seq_client * client)
290 {
291 	mutex_lock(&register_mutex);
292 	switch (client->type) {
293 	case NO_CLIENT:
294 		pr_warn("ALSA: seq: Trying to free unused client %d\n",
295 			client->number);
296 		break;
297 	case USER_CLIENT:
298 	case KERNEL_CLIENT:
299 		seq_free_client1(client);
300 		usage_free(&client_usage, 1);
301 		break;
302 
303 	default:
304 		pr_err("ALSA: seq: Trying to free client %d with undefined type = %d\n",
305 			   client->number, client->type);
306 	}
307 	mutex_unlock(&register_mutex);
308 
309 	snd_seq_system_client_ev_client_exit(client->number);
310 }
311 
312 
313 
314 /* -------------------------------------------------------- */
315 
316 /* create a user client */
317 static int snd_seq_open(struct inode *inode, struct file *file)
318 {
319 	int c, mode;			/* client id */
320 	struct snd_seq_client *client;
321 	struct snd_seq_user_client *user;
322 	int err;
323 
324 	err = stream_open(inode, file);
325 	if (err < 0)
326 		return err;
327 
328 	mutex_lock(&register_mutex);
329 	client = seq_create_client1(-1, SNDRV_SEQ_DEFAULT_EVENTS);
330 	if (!client) {
331 		mutex_unlock(&register_mutex);
332 		return -ENOMEM;	/* failure code */
333 	}
334 
335 	mode = snd_seq_file_flags(file);
336 	if (mode & SNDRV_SEQ_LFLG_INPUT)
337 		client->accept_input = 1;
338 	if (mode & SNDRV_SEQ_LFLG_OUTPUT)
339 		client->accept_output = 1;
340 
341 	user = &client->data.user;
342 	user->fifo = NULL;
343 	user->fifo_pool_size = 0;
344 
345 	if (mode & SNDRV_SEQ_LFLG_INPUT) {
346 		user->fifo_pool_size = SNDRV_SEQ_DEFAULT_CLIENT_EVENTS;
347 		user->fifo = snd_seq_fifo_new(user->fifo_pool_size);
348 		if (user->fifo == NULL) {
349 			seq_free_client1(client);
350 			kfree(client);
351 			mutex_unlock(&register_mutex);
352 			return -ENOMEM;
353 		}
354 	}
355 
356 	usage_alloc(&client_usage, 1);
357 	client->type = USER_CLIENT;
358 	mutex_unlock(&register_mutex);
359 
360 	c = client->number;
361 	file->private_data = client;
362 
363 	/* fill client data */
364 	user->file = file;
365 	sprintf(client->name, "Client-%d", c);
366 	client->data.user.owner = get_pid(task_pid(current));
367 
368 	/* make others aware this new client */
369 	snd_seq_system_client_ev_client_start(c);
370 
371 	return 0;
372 }
373 
374 /* delete a user client */
375 static int snd_seq_release(struct inode *inode, struct file *file)
376 {
377 	struct snd_seq_client *client = file->private_data;
378 
379 	if (client) {
380 		seq_free_client(client);
381 		if (client->data.user.fifo)
382 			snd_seq_fifo_delete(&client->data.user.fifo);
383 		put_pid(client->data.user.owner);
384 		kfree(client);
385 	}
386 
387 	return 0;
388 }
389 
390 
391 /* handle client read() */
392 /* possible error values:
393  *	-ENXIO	invalid client or file open mode
394  *	-ENOSPC	FIFO overflow (the flag is cleared after this error report)
395  *	-EINVAL	no enough user-space buffer to write the whole event
396  *	-EFAULT	seg. fault during copy to user space
397  */
398 static ssize_t snd_seq_read(struct file *file, char __user *buf, size_t count,
399 			    loff_t *offset)
400 {
401 	struct snd_seq_client *client = file->private_data;
402 	struct snd_seq_fifo *fifo;
403 	int err;
404 	long result = 0;
405 	struct snd_seq_event_cell *cell;
406 
407 	if (!(snd_seq_file_flags(file) & SNDRV_SEQ_LFLG_INPUT))
408 		return -ENXIO;
409 
410 	if (!access_ok(buf, count))
411 		return -EFAULT;
412 
413 	/* check client structures are in place */
414 	if (snd_BUG_ON(!client))
415 		return -ENXIO;
416 
417 	if (!client->accept_input)
418 		return -ENXIO;
419 	fifo = client->data.user.fifo;
420 	if (!fifo)
421 		return -ENXIO;
422 
423 	if (atomic_read(&fifo->overflow) > 0) {
424 		/* buffer overflow is detected */
425 		snd_seq_fifo_clear(fifo);
426 		/* return error code */
427 		return -ENOSPC;
428 	}
429 
430 	cell = NULL;
431 	err = 0;
432 	snd_seq_fifo_lock(fifo);
433 
434 	/* while data available in queue */
435 	while (count >= sizeof(struct snd_seq_event)) {
436 		int nonblock;
437 
438 		nonblock = (file->f_flags & O_NONBLOCK) || result > 0;
439 		err = snd_seq_fifo_cell_out(fifo, &cell, nonblock);
440 		if (err < 0)
441 			break;
442 		if (snd_seq_ev_is_variable(&cell->event)) {
443 			struct snd_seq_event tmpev;
444 			tmpev = cell->event;
445 			tmpev.data.ext.len &= ~SNDRV_SEQ_EXT_MASK;
446 			if (copy_to_user(buf, &tmpev, sizeof(struct snd_seq_event))) {
447 				err = -EFAULT;
448 				break;
449 			}
450 			count -= sizeof(struct snd_seq_event);
451 			buf += sizeof(struct snd_seq_event);
452 			err = snd_seq_expand_var_event(&cell->event, count,
453 						       (char __force *)buf, 0,
454 						       sizeof(struct snd_seq_event));
455 			if (err < 0)
456 				break;
457 			result += err;
458 			count -= err;
459 			buf += err;
460 		} else {
461 			if (copy_to_user(buf, &cell->event, sizeof(struct snd_seq_event))) {
462 				err = -EFAULT;
463 				break;
464 			}
465 			count -= sizeof(struct snd_seq_event);
466 			buf += sizeof(struct snd_seq_event);
467 		}
468 		snd_seq_cell_free(cell);
469 		cell = NULL; /* to be sure */
470 		result += sizeof(struct snd_seq_event);
471 	}
472 
473 	if (err < 0) {
474 		if (cell)
475 			snd_seq_fifo_cell_putback(fifo, cell);
476 		if (err == -EAGAIN && result > 0)
477 			err = 0;
478 	}
479 	snd_seq_fifo_unlock(fifo);
480 
481 	return (err < 0) ? err : result;
482 }
483 
484 
485 /*
486  * check access permission to the port
487  */
488 static int check_port_perm(struct snd_seq_client_port *port, unsigned int flags)
489 {
490 	if ((port->capability & flags) != flags)
491 		return 0;
492 	return flags;
493 }
494 
495 /*
496  * check if the destination client is available, and return the pointer
497  * if filter is non-zero, client filter bitmap is tested.
498  */
499 static struct snd_seq_client *get_event_dest_client(struct snd_seq_event *event,
500 						    int filter)
501 {
502 	struct snd_seq_client *dest;
503 
504 	dest = snd_seq_client_use_ptr(event->dest.client);
505 	if (dest == NULL)
506 		return NULL;
507 	if (! dest->accept_input)
508 		goto __not_avail;
509 	if ((dest->filter & SNDRV_SEQ_FILTER_USE_EVENT) &&
510 	    ! test_bit(event->type, dest->event_filter))
511 		goto __not_avail;
512 	if (filter && !(dest->filter & filter))
513 		goto __not_avail;
514 
515 	return dest; /* ok - accessible */
516 __not_avail:
517 	snd_seq_client_unlock(dest);
518 	return NULL;
519 }
520 
521 
522 /*
523  * Return the error event.
524  *
525  * If the receiver client is a user client, the original event is
526  * encapsulated in SNDRV_SEQ_EVENT_BOUNCE as variable length event.  If
527  * the original event is also variable length, the external data is
528  * copied after the event record.
529  * If the receiver client is a kernel client, the original event is
530  * quoted in SNDRV_SEQ_EVENT_KERNEL_ERROR, since this requires no extra
531  * kmalloc.
532  */
533 static int bounce_error_event(struct snd_seq_client *client,
534 			      struct snd_seq_event *event,
535 			      int err, int atomic, int hop)
536 {
537 	struct snd_seq_event bounce_ev;
538 	int result;
539 
540 	if (client == NULL ||
541 	    ! (client->filter & SNDRV_SEQ_FILTER_BOUNCE) ||
542 	    ! client->accept_input)
543 		return 0; /* ignored */
544 
545 	/* set up quoted error */
546 	memset(&bounce_ev, 0, sizeof(bounce_ev));
547 	bounce_ev.type = SNDRV_SEQ_EVENT_KERNEL_ERROR;
548 	bounce_ev.flags = SNDRV_SEQ_EVENT_LENGTH_FIXED;
549 	bounce_ev.queue = SNDRV_SEQ_QUEUE_DIRECT;
550 	bounce_ev.source.client = SNDRV_SEQ_CLIENT_SYSTEM;
551 	bounce_ev.source.port = SNDRV_SEQ_PORT_SYSTEM_ANNOUNCE;
552 	bounce_ev.dest.client = client->number;
553 	bounce_ev.dest.port = event->source.port;
554 	bounce_ev.data.quote.origin = event->dest;
555 	bounce_ev.data.quote.event = event;
556 	bounce_ev.data.quote.value = -err; /* use positive value */
557 	result = snd_seq_deliver_single_event(NULL, &bounce_ev, 0, atomic, hop + 1);
558 	if (result < 0) {
559 		client->event_lost++;
560 		return result;
561 	}
562 
563 	return result;
564 }
565 
566 
567 /*
568  * rewrite the time-stamp of the event record with the curren time
569  * of the given queue.
570  * return non-zero if updated.
571  */
572 static int update_timestamp_of_queue(struct snd_seq_event *event,
573 				     int queue, int real_time)
574 {
575 	struct snd_seq_queue *q;
576 
577 	q = queueptr(queue);
578 	if (! q)
579 		return 0;
580 	event->queue = queue;
581 	event->flags &= ~SNDRV_SEQ_TIME_STAMP_MASK;
582 	if (real_time) {
583 		event->time.time = snd_seq_timer_get_cur_time(q->timer, true);
584 		event->flags |= SNDRV_SEQ_TIME_STAMP_REAL;
585 	} else {
586 		event->time.tick = snd_seq_timer_get_cur_tick(q->timer);
587 		event->flags |= SNDRV_SEQ_TIME_STAMP_TICK;
588 	}
589 	queuefree(q);
590 	return 1;
591 }
592 
593 
594 /*
595  * deliver an event to the specified destination.
596  * if filter is non-zero, client filter bitmap is tested.
597  *
598  *  RETURN VALUE: 0 : if succeeded
599  *		 <0 : error
600  */
601 static int snd_seq_deliver_single_event(struct snd_seq_client *client,
602 					struct snd_seq_event *event,
603 					int filter, int atomic, int hop)
604 {
605 	struct snd_seq_client *dest = NULL;
606 	struct snd_seq_client_port *dest_port = NULL;
607 	int result = -ENOENT;
608 	int direct;
609 
610 	direct = snd_seq_ev_is_direct(event);
611 
612 	dest = get_event_dest_client(event, filter);
613 	if (dest == NULL)
614 		goto __skip;
615 	dest_port = snd_seq_port_use_ptr(dest, event->dest.port);
616 	if (dest_port == NULL)
617 		goto __skip;
618 
619 	/* check permission */
620 	if (! check_port_perm(dest_port, SNDRV_SEQ_PORT_CAP_WRITE)) {
621 		result = -EPERM;
622 		goto __skip;
623 	}
624 
625 	if (dest_port->timestamping)
626 		update_timestamp_of_queue(event, dest_port->time_queue,
627 					  dest_port->time_real);
628 
629 	switch (dest->type) {
630 	case USER_CLIENT:
631 		if (dest->data.user.fifo)
632 			result = snd_seq_fifo_event_in(dest->data.user.fifo, event);
633 		break;
634 
635 	case KERNEL_CLIENT:
636 		if (dest_port->event_input == NULL)
637 			break;
638 		result = dest_port->event_input(event, direct,
639 						dest_port->private_data,
640 						atomic, hop);
641 		break;
642 	default:
643 		break;
644 	}
645 
646   __skip:
647 	if (dest_port)
648 		snd_seq_port_unlock(dest_port);
649 	if (dest)
650 		snd_seq_client_unlock(dest);
651 
652 	if (result < 0 && !direct) {
653 		result = bounce_error_event(client, event, result, atomic, hop);
654 	}
655 	return result;
656 }
657 
658 
659 /*
660  * send the event to all subscribers:
661  */
662 static int deliver_to_subscribers(struct snd_seq_client *client,
663 				  struct snd_seq_event *event,
664 				  int atomic, int hop)
665 {
666 	struct snd_seq_subscribers *subs;
667 	int err, result = 0, num_ev = 0;
668 	struct snd_seq_event event_saved;
669 	struct snd_seq_client_port *src_port;
670 	struct snd_seq_port_subs_info *grp;
671 
672 	src_port = snd_seq_port_use_ptr(client, event->source.port);
673 	if (src_port == NULL)
674 		return -EINVAL; /* invalid source port */
675 	/* save original event record */
676 	event_saved = *event;
677 	grp = &src_port->c_src;
678 
679 	/* lock list */
680 	if (atomic)
681 		read_lock(&grp->list_lock);
682 	else
683 		down_read_nested(&grp->list_mutex, hop);
684 	list_for_each_entry(subs, &grp->list_head, src_list) {
685 		/* both ports ready? */
686 		if (atomic_read(&subs->ref_count) != 2)
687 			continue;
688 		event->dest = subs->info.dest;
689 		if (subs->info.flags & SNDRV_SEQ_PORT_SUBS_TIMESTAMP)
690 			/* convert time according to flag with subscription */
691 			update_timestamp_of_queue(event, subs->info.queue,
692 						  subs->info.flags & SNDRV_SEQ_PORT_SUBS_TIME_REAL);
693 		err = snd_seq_deliver_single_event(client, event,
694 						   0, atomic, hop);
695 		if (err < 0) {
696 			/* save first error that occurs and continue */
697 			if (!result)
698 				result = err;
699 			continue;
700 		}
701 		num_ev++;
702 		/* restore original event record */
703 		*event = event_saved;
704 	}
705 	if (atomic)
706 		read_unlock(&grp->list_lock);
707 	else
708 		up_read(&grp->list_mutex);
709 	*event = event_saved; /* restore */
710 	snd_seq_port_unlock(src_port);
711 	return (result < 0) ? result : num_ev;
712 }
713 
714 
715 #ifdef SUPPORT_BROADCAST
716 /*
717  * broadcast to all ports:
718  */
719 static int port_broadcast_event(struct snd_seq_client *client,
720 				struct snd_seq_event *event,
721 				int atomic, int hop)
722 {
723 	int num_ev = 0, err, result = 0;
724 	struct snd_seq_client *dest_client;
725 	struct snd_seq_client_port *port;
726 
727 	dest_client = get_event_dest_client(event, SNDRV_SEQ_FILTER_BROADCAST);
728 	if (dest_client == NULL)
729 		return 0; /* no matching destination */
730 
731 	read_lock(&dest_client->ports_lock);
732 	list_for_each_entry(port, &dest_client->ports_list_head, list) {
733 		event->dest.port = port->addr.port;
734 		/* pass NULL as source client to avoid error bounce */
735 		err = snd_seq_deliver_single_event(NULL, event,
736 						   SNDRV_SEQ_FILTER_BROADCAST,
737 						   atomic, hop);
738 		if (err < 0) {
739 			/* save first error that occurs and continue */
740 			if (!result)
741 				result = err;
742 			continue;
743 		}
744 		num_ev++;
745 	}
746 	read_unlock(&dest_client->ports_lock);
747 	snd_seq_client_unlock(dest_client);
748 	event->dest.port = SNDRV_SEQ_ADDRESS_BROADCAST; /* restore */
749 	return (result < 0) ? result : num_ev;
750 }
751 
752 /*
753  * send the event to all clients:
754  * if destination port is also ADDRESS_BROADCAST, deliver to all ports.
755  */
756 static int broadcast_event(struct snd_seq_client *client,
757 			   struct snd_seq_event *event, int atomic, int hop)
758 {
759 	int err, result = 0, num_ev = 0;
760 	int dest;
761 	struct snd_seq_addr addr;
762 
763 	addr = event->dest; /* save */
764 
765 	for (dest = 0; dest < SNDRV_SEQ_MAX_CLIENTS; dest++) {
766 		/* don't send to itself */
767 		if (dest == client->number)
768 			continue;
769 		event->dest.client = dest;
770 		event->dest.port = addr.port;
771 		if (addr.port == SNDRV_SEQ_ADDRESS_BROADCAST)
772 			err = port_broadcast_event(client, event, atomic, hop);
773 		else
774 			/* pass NULL as source client to avoid error bounce */
775 			err = snd_seq_deliver_single_event(NULL, event,
776 							   SNDRV_SEQ_FILTER_BROADCAST,
777 							   atomic, hop);
778 		if (err < 0) {
779 			/* save first error that occurs and continue */
780 			if (!result)
781 				result = err;
782 			continue;
783 		}
784 		num_ev += err;
785 	}
786 	event->dest = addr; /* restore */
787 	return (result < 0) ? result : num_ev;
788 }
789 
790 
791 /* multicast - not supported yet */
792 static int multicast_event(struct snd_seq_client *client, struct snd_seq_event *event,
793 			   int atomic, int hop)
794 {
795 	pr_debug("ALSA: seq: multicast not supported yet.\n");
796 	return 0; /* ignored */
797 }
798 #endif /* SUPPORT_BROADCAST */
799 
800 
801 /* deliver an event to the destination port(s).
802  * if the event is to subscribers or broadcast, the event is dispatched
803  * to multiple targets.
804  *
805  * RETURN VALUE: n > 0  : the number of delivered events.
806  *               n == 0 : the event was not passed to any client.
807  *               n < 0  : error - event was not processed.
808  */
809 static int snd_seq_deliver_event(struct snd_seq_client *client, struct snd_seq_event *event,
810 				 int atomic, int hop)
811 {
812 	int result;
813 
814 	hop++;
815 	if (hop >= SNDRV_SEQ_MAX_HOPS) {
816 		pr_debug("ALSA: seq: too long delivery path (%d:%d->%d:%d)\n",
817 			   event->source.client, event->source.port,
818 			   event->dest.client, event->dest.port);
819 		return -EMLINK;
820 	}
821 
822 	if (snd_seq_ev_is_variable(event) &&
823 	    snd_BUG_ON(atomic && (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR)))
824 		return -EINVAL;
825 
826 	if (event->queue == SNDRV_SEQ_ADDRESS_SUBSCRIBERS ||
827 	    event->dest.client == SNDRV_SEQ_ADDRESS_SUBSCRIBERS)
828 		result = deliver_to_subscribers(client, event, atomic, hop);
829 #ifdef SUPPORT_BROADCAST
830 	else if (event->queue == SNDRV_SEQ_ADDRESS_BROADCAST ||
831 		 event->dest.client == SNDRV_SEQ_ADDRESS_BROADCAST)
832 		result = broadcast_event(client, event, atomic, hop);
833 	else if (event->dest.client >= SNDRV_SEQ_MAX_CLIENTS)
834 		result = multicast_event(client, event, atomic, hop);
835 	else if (event->dest.port == SNDRV_SEQ_ADDRESS_BROADCAST)
836 		result = port_broadcast_event(client, event, atomic, hop);
837 #endif
838 	else
839 		result = snd_seq_deliver_single_event(client, event, 0, atomic, hop);
840 
841 	return result;
842 }
843 
844 /*
845  * dispatch an event cell:
846  * This function is called only from queue check routines in timer
847  * interrupts or after enqueued.
848  * The event cell shall be released or re-queued in this function.
849  *
850  * RETURN VALUE: n > 0  : the number of delivered events.
851  *		 n == 0 : the event was not passed to any client.
852  *		 n < 0  : error - event was not processed.
853  */
854 int snd_seq_dispatch_event(struct snd_seq_event_cell *cell, int atomic, int hop)
855 {
856 	struct snd_seq_client *client;
857 	int result;
858 
859 	if (snd_BUG_ON(!cell))
860 		return -EINVAL;
861 
862 	client = snd_seq_client_use_ptr(cell->event.source.client);
863 	if (client == NULL) {
864 		snd_seq_cell_free(cell); /* release this cell */
865 		return -EINVAL;
866 	}
867 
868 	if (cell->event.type == SNDRV_SEQ_EVENT_NOTE) {
869 		/* NOTE event:
870 		 * the event cell is re-used as a NOTE-OFF event and
871 		 * enqueued again.
872 		 */
873 		struct snd_seq_event tmpev, *ev;
874 
875 		/* reserve this event to enqueue note-off later */
876 		tmpev = cell->event;
877 		tmpev.type = SNDRV_SEQ_EVENT_NOTEON;
878 		result = snd_seq_deliver_event(client, &tmpev, atomic, hop);
879 
880 		/*
881 		 * This was originally a note event.  We now re-use the
882 		 * cell for the note-off event.
883 		 */
884 
885 		ev = &cell->event;
886 		ev->type = SNDRV_SEQ_EVENT_NOTEOFF;
887 		ev->flags |= SNDRV_SEQ_PRIORITY_HIGH;
888 
889 		/* add the duration time */
890 		switch (ev->flags & SNDRV_SEQ_TIME_STAMP_MASK) {
891 		case SNDRV_SEQ_TIME_STAMP_TICK:
892 			ev->time.tick += ev->data.note.duration;
893 			break;
894 		case SNDRV_SEQ_TIME_STAMP_REAL:
895 			/* unit for duration is ms */
896 			ev->time.time.tv_nsec += 1000000 * (ev->data.note.duration % 1000);
897 			ev->time.time.tv_sec += ev->data.note.duration / 1000 +
898 						ev->time.time.tv_nsec / 1000000000;
899 			ev->time.time.tv_nsec %= 1000000000;
900 			break;
901 		}
902 		ev->data.note.velocity = ev->data.note.off_velocity;
903 
904 		/* Now queue this cell as the note off event */
905 		if (snd_seq_enqueue_event(cell, atomic, hop) < 0)
906 			snd_seq_cell_free(cell); /* release this cell */
907 
908 	} else {
909 		/* Normal events:
910 		 * event cell is freed after processing the event
911 		 */
912 
913 		result = snd_seq_deliver_event(client, &cell->event, atomic, hop);
914 		snd_seq_cell_free(cell);
915 	}
916 
917 	snd_seq_client_unlock(client);
918 	return result;
919 }
920 
921 
922 /* Allocate a cell from client pool and enqueue it to queue:
923  * if pool is empty and blocking is TRUE, sleep until a new cell is
924  * available.
925  */
926 static int snd_seq_client_enqueue_event(struct snd_seq_client *client,
927 					struct snd_seq_event *event,
928 					struct file *file, int blocking,
929 					int atomic, int hop,
930 					struct mutex *mutexp)
931 {
932 	struct snd_seq_event_cell *cell;
933 	int err;
934 
935 	/* special queue values - force direct passing */
936 	if (event->queue == SNDRV_SEQ_ADDRESS_SUBSCRIBERS) {
937 		event->dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
938 		event->queue = SNDRV_SEQ_QUEUE_DIRECT;
939 	} else
940 #ifdef SUPPORT_BROADCAST
941 		if (event->queue == SNDRV_SEQ_ADDRESS_BROADCAST) {
942 			event->dest.client = SNDRV_SEQ_ADDRESS_BROADCAST;
943 			event->queue = SNDRV_SEQ_QUEUE_DIRECT;
944 		}
945 #endif
946 	if (event->dest.client == SNDRV_SEQ_ADDRESS_SUBSCRIBERS) {
947 		/* check presence of source port */
948 		struct snd_seq_client_port *src_port = snd_seq_port_use_ptr(client, event->source.port);
949 		if (src_port == NULL)
950 			return -EINVAL;
951 		snd_seq_port_unlock(src_port);
952 	}
953 
954 	/* direct event processing without enqueued */
955 	if (snd_seq_ev_is_direct(event)) {
956 		if (event->type == SNDRV_SEQ_EVENT_NOTE)
957 			return -EINVAL; /* this event must be enqueued! */
958 		return snd_seq_deliver_event(client, event, atomic, hop);
959 	}
960 
961 	/* Not direct, normal queuing */
962 	if (snd_seq_queue_is_used(event->queue, client->number) <= 0)
963 		return -EINVAL;  /* invalid queue */
964 	if (! snd_seq_write_pool_allocated(client))
965 		return -ENXIO; /* queue is not allocated */
966 
967 	/* allocate an event cell */
968 	err = snd_seq_event_dup(client->pool, event, &cell, !blocking || atomic,
969 				file, mutexp);
970 	if (err < 0)
971 		return err;
972 
973 	/* we got a cell. enqueue it. */
974 	err = snd_seq_enqueue_event(cell, atomic, hop);
975 	if (err < 0) {
976 		snd_seq_cell_free(cell);
977 		return err;
978 	}
979 
980 	return 0;
981 }
982 
983 
984 /*
985  * check validity of event type and data length.
986  * return non-zero if invalid.
987  */
988 static int check_event_type_and_length(struct snd_seq_event *ev)
989 {
990 	switch (snd_seq_ev_length_type(ev)) {
991 	case SNDRV_SEQ_EVENT_LENGTH_FIXED:
992 		if (snd_seq_ev_is_variable_type(ev))
993 			return -EINVAL;
994 		break;
995 	case SNDRV_SEQ_EVENT_LENGTH_VARIABLE:
996 		if (! snd_seq_ev_is_variable_type(ev) ||
997 		    (ev->data.ext.len & ~SNDRV_SEQ_EXT_MASK) >= SNDRV_SEQ_MAX_EVENT_LEN)
998 			return -EINVAL;
999 		break;
1000 	case SNDRV_SEQ_EVENT_LENGTH_VARUSR:
1001 		if (! snd_seq_ev_is_direct(ev))
1002 			return -EINVAL;
1003 		break;
1004 	}
1005 	return 0;
1006 }
1007 
1008 
1009 /* handle write() */
1010 /* possible error values:
1011  *	-ENXIO	invalid client or file open mode
1012  *	-ENOMEM	malloc failed
1013  *	-EFAULT	seg. fault during copy from user space
1014  *	-EINVAL	invalid event
1015  *	-EAGAIN	no space in output pool
1016  *	-EINTR	interrupts while sleep
1017  *	-EMLINK	too many hops
1018  *	others	depends on return value from driver callback
1019  */
1020 static ssize_t snd_seq_write(struct file *file, const char __user *buf,
1021 			     size_t count, loff_t *offset)
1022 {
1023 	struct snd_seq_client *client = file->private_data;
1024 	int written = 0, len;
1025 	int err, handled;
1026 	struct snd_seq_event event;
1027 
1028 	if (!(snd_seq_file_flags(file) & SNDRV_SEQ_LFLG_OUTPUT))
1029 		return -ENXIO;
1030 
1031 	/* check client structures are in place */
1032 	if (snd_BUG_ON(!client))
1033 		return -ENXIO;
1034 
1035 	if (!client->accept_output || client->pool == NULL)
1036 		return -ENXIO;
1037 
1038  repeat:
1039 	handled = 0;
1040 	/* allocate the pool now if the pool is not allocated yet */
1041 	mutex_lock(&client->ioctl_mutex);
1042 	if (client->pool->size > 0 && !snd_seq_write_pool_allocated(client)) {
1043 		err = snd_seq_pool_init(client->pool);
1044 		if (err < 0)
1045 			goto out;
1046 	}
1047 
1048 	/* only process whole events */
1049 	err = -EINVAL;
1050 	while (count >= sizeof(struct snd_seq_event)) {
1051 		/* Read in the event header from the user */
1052 		len = sizeof(event);
1053 		if (copy_from_user(&event, buf, len)) {
1054 			err = -EFAULT;
1055 			break;
1056 		}
1057 		event.source.client = client->number;	/* fill in client number */
1058 		/* Check for extension data length */
1059 		if (check_event_type_and_length(&event)) {
1060 			err = -EINVAL;
1061 			break;
1062 		}
1063 
1064 		/* check for special events */
1065 		if (event.type == SNDRV_SEQ_EVENT_NONE)
1066 			goto __skip_event;
1067 		else if (snd_seq_ev_is_reserved(&event)) {
1068 			err = -EINVAL;
1069 			break;
1070 		}
1071 
1072 		if (snd_seq_ev_is_variable(&event)) {
1073 			int extlen = event.data.ext.len & ~SNDRV_SEQ_EXT_MASK;
1074 			if ((size_t)(extlen + len) > count) {
1075 				/* back out, will get an error this time or next */
1076 				err = -EINVAL;
1077 				break;
1078 			}
1079 			/* set user space pointer */
1080 			event.data.ext.len = extlen | SNDRV_SEQ_EXT_USRPTR;
1081 			event.data.ext.ptr = (char __force *)buf
1082 						+ sizeof(struct snd_seq_event);
1083 			len += extlen; /* increment data length */
1084 		} else {
1085 #ifdef CONFIG_COMPAT
1086 			if (client->convert32 && snd_seq_ev_is_varusr(&event)) {
1087 				void *ptr = (void __force *)compat_ptr(event.data.raw32.d[1]);
1088 				event.data.ext.ptr = ptr;
1089 			}
1090 #endif
1091 		}
1092 
1093 		/* ok, enqueue it */
1094 		err = snd_seq_client_enqueue_event(client, &event, file,
1095 						   !(file->f_flags & O_NONBLOCK),
1096 						   0, 0, &client->ioctl_mutex);
1097 		if (err < 0)
1098 			break;
1099 		handled++;
1100 
1101 	__skip_event:
1102 		/* Update pointers and counts */
1103 		count -= len;
1104 		buf += len;
1105 		written += len;
1106 
1107 		/* let's have a coffee break if too many events are queued */
1108 		if (++handled >= 200) {
1109 			mutex_unlock(&client->ioctl_mutex);
1110 			goto repeat;
1111 		}
1112 	}
1113 
1114  out:
1115 	mutex_unlock(&client->ioctl_mutex);
1116 	return written ? written : err;
1117 }
1118 
1119 
1120 /*
1121  * handle polling
1122  */
1123 static __poll_t snd_seq_poll(struct file *file, poll_table * wait)
1124 {
1125 	struct snd_seq_client *client = file->private_data;
1126 	__poll_t mask = 0;
1127 
1128 	/* check client structures are in place */
1129 	if (snd_BUG_ON(!client))
1130 		return EPOLLERR;
1131 
1132 	if ((snd_seq_file_flags(file) & SNDRV_SEQ_LFLG_INPUT) &&
1133 	    client->data.user.fifo) {
1134 
1135 		/* check if data is available in the outqueue */
1136 		if (snd_seq_fifo_poll_wait(client->data.user.fifo, file, wait))
1137 			mask |= EPOLLIN | EPOLLRDNORM;
1138 	}
1139 
1140 	if (snd_seq_file_flags(file) & SNDRV_SEQ_LFLG_OUTPUT) {
1141 
1142 		/* check if data is available in the pool */
1143 		if (!snd_seq_write_pool_allocated(client) ||
1144 		    snd_seq_pool_poll_wait(client->pool, file, wait))
1145 			mask |= EPOLLOUT | EPOLLWRNORM;
1146 	}
1147 
1148 	return mask;
1149 }
1150 
1151 
1152 /*-----------------------------------------------------*/
1153 
1154 static int snd_seq_ioctl_pversion(struct snd_seq_client *client, void *arg)
1155 {
1156 	int *pversion = arg;
1157 
1158 	*pversion = SNDRV_SEQ_VERSION;
1159 	return 0;
1160 }
1161 
1162 static int snd_seq_ioctl_client_id(struct snd_seq_client *client, void *arg)
1163 {
1164 	int *client_id = arg;
1165 
1166 	*client_id = client->number;
1167 	return 0;
1168 }
1169 
1170 /* SYSTEM_INFO ioctl() */
1171 static int snd_seq_ioctl_system_info(struct snd_seq_client *client, void *arg)
1172 {
1173 	struct snd_seq_system_info *info = arg;
1174 
1175 	memset(info, 0, sizeof(*info));
1176 	/* fill the info fields */
1177 	info->queues = SNDRV_SEQ_MAX_QUEUES;
1178 	info->clients = SNDRV_SEQ_MAX_CLIENTS;
1179 	info->ports = SNDRV_SEQ_MAX_PORTS;
1180 	info->channels = 256;	/* fixed limit */
1181 	info->cur_clients = client_usage.cur;
1182 	info->cur_queues = snd_seq_queue_get_cur_queues();
1183 
1184 	return 0;
1185 }
1186 
1187 
1188 /* RUNNING_MODE ioctl() */
1189 static int snd_seq_ioctl_running_mode(struct snd_seq_client *client, void  *arg)
1190 {
1191 	struct snd_seq_running_info *info = arg;
1192 	struct snd_seq_client *cptr;
1193 	int err = 0;
1194 
1195 	/* requested client number */
1196 	cptr = snd_seq_client_use_ptr(info->client);
1197 	if (cptr == NULL)
1198 		return -ENOENT;		/* don't change !!! */
1199 
1200 #ifdef SNDRV_BIG_ENDIAN
1201 	if (!info->big_endian) {
1202 		err = -EINVAL;
1203 		goto __err;
1204 	}
1205 #else
1206 	if (info->big_endian) {
1207 		err = -EINVAL;
1208 		goto __err;
1209 	}
1210 
1211 #endif
1212 	if (info->cpu_mode > sizeof(long)) {
1213 		err = -EINVAL;
1214 		goto __err;
1215 	}
1216 	cptr->convert32 = (info->cpu_mode < sizeof(long));
1217  __err:
1218 	snd_seq_client_unlock(cptr);
1219 	return err;
1220 }
1221 
1222 /* CLIENT_INFO ioctl() */
1223 static void get_client_info(struct snd_seq_client *cptr,
1224 			    struct snd_seq_client_info *info)
1225 {
1226 	info->client = cptr->number;
1227 
1228 	/* fill the info fields */
1229 	info->type = cptr->type;
1230 	strcpy(info->name, cptr->name);
1231 	info->filter = cptr->filter;
1232 	info->event_lost = cptr->event_lost;
1233 	memcpy(info->event_filter, cptr->event_filter, 32);
1234 	info->num_ports = cptr->num_ports;
1235 
1236 	if (cptr->type == USER_CLIENT)
1237 		info->pid = pid_vnr(cptr->data.user.owner);
1238 	else
1239 		info->pid = -1;
1240 
1241 	if (cptr->type == KERNEL_CLIENT)
1242 		info->card = cptr->data.kernel.card ? cptr->data.kernel.card->number : -1;
1243 	else
1244 		info->card = -1;
1245 
1246 	memset(info->reserved, 0, sizeof(info->reserved));
1247 }
1248 
1249 static int snd_seq_ioctl_get_client_info(struct snd_seq_client *client,
1250 					 void *arg)
1251 {
1252 	struct snd_seq_client_info *client_info = arg;
1253 	struct snd_seq_client *cptr;
1254 
1255 	/* requested client number */
1256 	cptr = snd_seq_client_use_ptr(client_info->client);
1257 	if (cptr == NULL)
1258 		return -ENOENT;		/* don't change !!! */
1259 
1260 	get_client_info(cptr, client_info);
1261 	snd_seq_client_unlock(cptr);
1262 
1263 	return 0;
1264 }
1265 
1266 
1267 /* CLIENT_INFO ioctl() */
1268 static int snd_seq_ioctl_set_client_info(struct snd_seq_client *client,
1269 					 void *arg)
1270 {
1271 	struct snd_seq_client_info *client_info = arg;
1272 
1273 	/* it is not allowed to set the info fields for an another client */
1274 	if (client->number != client_info->client)
1275 		return -EPERM;
1276 	/* also client type must be set now */
1277 	if (client->type != client_info->type)
1278 		return -EINVAL;
1279 
1280 	/* fill the info fields */
1281 	if (client_info->name[0])
1282 		strscpy(client->name, client_info->name, sizeof(client->name));
1283 
1284 	client->filter = client_info->filter;
1285 	client->event_lost = client_info->event_lost;
1286 	memcpy(client->event_filter, client_info->event_filter, 32);
1287 
1288 	return 0;
1289 }
1290 
1291 
1292 /*
1293  * CREATE PORT ioctl()
1294  */
1295 static int snd_seq_ioctl_create_port(struct snd_seq_client *client, void *arg)
1296 {
1297 	struct snd_seq_port_info *info = arg;
1298 	struct snd_seq_client_port *port;
1299 	struct snd_seq_port_callback *callback;
1300 	int port_idx;
1301 
1302 	/* it is not allowed to create the port for an another client */
1303 	if (info->addr.client != client->number)
1304 		return -EPERM;
1305 
1306 	port = snd_seq_create_port(client, (info->flags & SNDRV_SEQ_PORT_FLG_GIVEN_PORT) ? info->addr.port : -1);
1307 	if (port == NULL)
1308 		return -ENOMEM;
1309 
1310 	if (client->type == USER_CLIENT && info->kernel) {
1311 		port_idx = port->addr.port;
1312 		snd_seq_port_unlock(port);
1313 		snd_seq_delete_port(client, port_idx);
1314 		return -EINVAL;
1315 	}
1316 	if (client->type == KERNEL_CLIENT) {
1317 		callback = info->kernel;
1318 		if (callback) {
1319 			if (callback->owner)
1320 				port->owner = callback->owner;
1321 			port->private_data = callback->private_data;
1322 			port->private_free = callback->private_free;
1323 			port->event_input = callback->event_input;
1324 			port->c_src.open = callback->subscribe;
1325 			port->c_src.close = callback->unsubscribe;
1326 			port->c_dest.open = callback->use;
1327 			port->c_dest.close = callback->unuse;
1328 		}
1329 	}
1330 
1331 	info->addr = port->addr;
1332 
1333 	snd_seq_set_port_info(port, info);
1334 	snd_seq_system_client_ev_port_start(port->addr.client, port->addr.port);
1335 	snd_seq_port_unlock(port);
1336 
1337 	return 0;
1338 }
1339 
1340 /*
1341  * DELETE PORT ioctl()
1342  */
1343 static int snd_seq_ioctl_delete_port(struct snd_seq_client *client, void *arg)
1344 {
1345 	struct snd_seq_port_info *info = arg;
1346 	int err;
1347 
1348 	/* it is not allowed to remove the port for an another client */
1349 	if (info->addr.client != client->number)
1350 		return -EPERM;
1351 
1352 	err = snd_seq_delete_port(client, info->addr.port);
1353 	if (err >= 0)
1354 		snd_seq_system_client_ev_port_exit(client->number, info->addr.port);
1355 	return err;
1356 }
1357 
1358 
1359 /*
1360  * GET_PORT_INFO ioctl() (on any client)
1361  */
1362 static int snd_seq_ioctl_get_port_info(struct snd_seq_client *client, void *arg)
1363 {
1364 	struct snd_seq_port_info *info = arg;
1365 	struct snd_seq_client *cptr;
1366 	struct snd_seq_client_port *port;
1367 
1368 	cptr = snd_seq_client_use_ptr(info->addr.client);
1369 	if (cptr == NULL)
1370 		return -ENXIO;
1371 
1372 	port = snd_seq_port_use_ptr(cptr, info->addr.port);
1373 	if (port == NULL) {
1374 		snd_seq_client_unlock(cptr);
1375 		return -ENOENT;			/* don't change */
1376 	}
1377 
1378 	/* get port info */
1379 	snd_seq_get_port_info(port, info);
1380 	snd_seq_port_unlock(port);
1381 	snd_seq_client_unlock(cptr);
1382 
1383 	return 0;
1384 }
1385 
1386 
1387 /*
1388  * SET_PORT_INFO ioctl() (only ports on this/own client)
1389  */
1390 static int snd_seq_ioctl_set_port_info(struct snd_seq_client *client, void *arg)
1391 {
1392 	struct snd_seq_port_info *info = arg;
1393 	struct snd_seq_client_port *port;
1394 
1395 	if (info->addr.client != client->number) /* only set our own ports ! */
1396 		return -EPERM;
1397 	port = snd_seq_port_use_ptr(client, info->addr.port);
1398 	if (port) {
1399 		snd_seq_set_port_info(port, info);
1400 		snd_seq_port_unlock(port);
1401 	}
1402 	return 0;
1403 }
1404 
1405 
1406 /*
1407  * port subscription (connection)
1408  */
1409 #define PERM_RD		(SNDRV_SEQ_PORT_CAP_READ|SNDRV_SEQ_PORT_CAP_SUBS_READ)
1410 #define PERM_WR		(SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_SUBS_WRITE)
1411 
1412 static int check_subscription_permission(struct snd_seq_client *client,
1413 					 struct snd_seq_client_port *sport,
1414 					 struct snd_seq_client_port *dport,
1415 					 struct snd_seq_port_subscribe *subs)
1416 {
1417 	if (client->number != subs->sender.client &&
1418 	    client->number != subs->dest.client) {
1419 		/* connection by third client - check export permission */
1420 		if (check_port_perm(sport, SNDRV_SEQ_PORT_CAP_NO_EXPORT))
1421 			return -EPERM;
1422 		if (check_port_perm(dport, SNDRV_SEQ_PORT_CAP_NO_EXPORT))
1423 			return -EPERM;
1424 	}
1425 
1426 	/* check read permission */
1427 	/* if sender or receiver is the subscribing client itself,
1428 	 * no permission check is necessary
1429 	 */
1430 	if (client->number != subs->sender.client) {
1431 		if (! check_port_perm(sport, PERM_RD))
1432 			return -EPERM;
1433 	}
1434 	/* check write permission */
1435 	if (client->number != subs->dest.client) {
1436 		if (! check_port_perm(dport, PERM_WR))
1437 			return -EPERM;
1438 	}
1439 	return 0;
1440 }
1441 
1442 /*
1443  * send an subscription notify event to user client:
1444  * client must be user client.
1445  */
1446 int snd_seq_client_notify_subscription(int client, int port,
1447 				       struct snd_seq_port_subscribe *info,
1448 				       int evtype)
1449 {
1450 	struct snd_seq_event event;
1451 
1452 	memset(&event, 0, sizeof(event));
1453 	event.type = evtype;
1454 	event.data.connect.dest = info->dest;
1455 	event.data.connect.sender = info->sender;
1456 
1457 	return snd_seq_system_notify(client, port, &event);  /* non-atomic */
1458 }
1459 
1460 
1461 /*
1462  * add to port's subscription list IOCTL interface
1463  */
1464 static int snd_seq_ioctl_subscribe_port(struct snd_seq_client *client,
1465 					void *arg)
1466 {
1467 	struct snd_seq_port_subscribe *subs = arg;
1468 	int result = -EINVAL;
1469 	struct snd_seq_client *receiver = NULL, *sender = NULL;
1470 	struct snd_seq_client_port *sport = NULL, *dport = NULL;
1471 
1472 	receiver = snd_seq_client_use_ptr(subs->dest.client);
1473 	if (!receiver)
1474 		goto __end;
1475 	sender = snd_seq_client_use_ptr(subs->sender.client);
1476 	if (!sender)
1477 		goto __end;
1478 	sport = snd_seq_port_use_ptr(sender, subs->sender.port);
1479 	if (!sport)
1480 		goto __end;
1481 	dport = snd_seq_port_use_ptr(receiver, subs->dest.port);
1482 	if (!dport)
1483 		goto __end;
1484 
1485 	result = check_subscription_permission(client, sport, dport, subs);
1486 	if (result < 0)
1487 		goto __end;
1488 
1489 	/* connect them */
1490 	result = snd_seq_port_connect(client, sender, sport, receiver, dport, subs);
1491 	if (! result) /* broadcast announce */
1492 		snd_seq_client_notify_subscription(SNDRV_SEQ_ADDRESS_SUBSCRIBERS, 0,
1493 						   subs, SNDRV_SEQ_EVENT_PORT_SUBSCRIBED);
1494       __end:
1495       	if (sport)
1496 		snd_seq_port_unlock(sport);
1497 	if (dport)
1498 		snd_seq_port_unlock(dport);
1499 	if (sender)
1500 		snd_seq_client_unlock(sender);
1501 	if (receiver)
1502 		snd_seq_client_unlock(receiver);
1503 	return result;
1504 }
1505 
1506 
1507 /*
1508  * remove from port's subscription list
1509  */
1510 static int snd_seq_ioctl_unsubscribe_port(struct snd_seq_client *client,
1511 					  void *arg)
1512 {
1513 	struct snd_seq_port_subscribe *subs = arg;
1514 	int result = -ENXIO;
1515 	struct snd_seq_client *receiver = NULL, *sender = NULL;
1516 	struct snd_seq_client_port *sport = NULL, *dport = NULL;
1517 
1518 	receiver = snd_seq_client_use_ptr(subs->dest.client);
1519 	if (!receiver)
1520 		goto __end;
1521 	sender = snd_seq_client_use_ptr(subs->sender.client);
1522 	if (!sender)
1523 		goto __end;
1524 	sport = snd_seq_port_use_ptr(sender, subs->sender.port);
1525 	if (!sport)
1526 		goto __end;
1527 	dport = snd_seq_port_use_ptr(receiver, subs->dest.port);
1528 	if (!dport)
1529 		goto __end;
1530 
1531 	result = check_subscription_permission(client, sport, dport, subs);
1532 	if (result < 0)
1533 		goto __end;
1534 
1535 	result = snd_seq_port_disconnect(client, sender, sport, receiver, dport, subs);
1536 	if (! result) /* broadcast announce */
1537 		snd_seq_client_notify_subscription(SNDRV_SEQ_ADDRESS_SUBSCRIBERS, 0,
1538 						   subs, SNDRV_SEQ_EVENT_PORT_UNSUBSCRIBED);
1539       __end:
1540       	if (sport)
1541 		snd_seq_port_unlock(sport);
1542 	if (dport)
1543 		snd_seq_port_unlock(dport);
1544 	if (sender)
1545 		snd_seq_client_unlock(sender);
1546 	if (receiver)
1547 		snd_seq_client_unlock(receiver);
1548 	return result;
1549 }
1550 
1551 
1552 /* CREATE_QUEUE ioctl() */
1553 static int snd_seq_ioctl_create_queue(struct snd_seq_client *client, void *arg)
1554 {
1555 	struct snd_seq_queue_info *info = arg;
1556 	struct snd_seq_queue *q;
1557 
1558 	q = snd_seq_queue_alloc(client->number, info->locked, info->flags);
1559 	if (IS_ERR(q))
1560 		return PTR_ERR(q);
1561 
1562 	info->queue = q->queue;
1563 	info->locked = q->locked;
1564 	info->owner = q->owner;
1565 
1566 	/* set queue name */
1567 	if (!info->name[0])
1568 		snprintf(info->name, sizeof(info->name), "Queue-%d", q->queue);
1569 	strscpy(q->name, info->name, sizeof(q->name));
1570 	snd_use_lock_free(&q->use_lock);
1571 
1572 	return 0;
1573 }
1574 
1575 /* DELETE_QUEUE ioctl() */
1576 static int snd_seq_ioctl_delete_queue(struct snd_seq_client *client, void *arg)
1577 {
1578 	struct snd_seq_queue_info *info = arg;
1579 
1580 	return snd_seq_queue_delete(client->number, info->queue);
1581 }
1582 
1583 /* GET_QUEUE_INFO ioctl() */
1584 static int snd_seq_ioctl_get_queue_info(struct snd_seq_client *client,
1585 					void *arg)
1586 {
1587 	struct snd_seq_queue_info *info = arg;
1588 	struct snd_seq_queue *q;
1589 
1590 	q = queueptr(info->queue);
1591 	if (q == NULL)
1592 		return -EINVAL;
1593 
1594 	memset(info, 0, sizeof(*info));
1595 	info->queue = q->queue;
1596 	info->owner = q->owner;
1597 	info->locked = q->locked;
1598 	strscpy(info->name, q->name, sizeof(info->name));
1599 	queuefree(q);
1600 
1601 	return 0;
1602 }
1603 
1604 /* SET_QUEUE_INFO ioctl() */
1605 static int snd_seq_ioctl_set_queue_info(struct snd_seq_client *client,
1606 					void *arg)
1607 {
1608 	struct snd_seq_queue_info *info = arg;
1609 	struct snd_seq_queue *q;
1610 
1611 	if (info->owner != client->number)
1612 		return -EINVAL;
1613 
1614 	/* change owner/locked permission */
1615 	if (snd_seq_queue_check_access(info->queue, client->number)) {
1616 		if (snd_seq_queue_set_owner(info->queue, client->number, info->locked) < 0)
1617 			return -EPERM;
1618 		if (info->locked)
1619 			snd_seq_queue_use(info->queue, client->number, 1);
1620 	} else {
1621 		return -EPERM;
1622 	}
1623 
1624 	q = queueptr(info->queue);
1625 	if (! q)
1626 		return -EINVAL;
1627 	if (q->owner != client->number) {
1628 		queuefree(q);
1629 		return -EPERM;
1630 	}
1631 	strscpy(q->name, info->name, sizeof(q->name));
1632 	queuefree(q);
1633 
1634 	return 0;
1635 }
1636 
1637 /* GET_NAMED_QUEUE ioctl() */
1638 static int snd_seq_ioctl_get_named_queue(struct snd_seq_client *client,
1639 					 void *arg)
1640 {
1641 	struct snd_seq_queue_info *info = arg;
1642 	struct snd_seq_queue *q;
1643 
1644 	q = snd_seq_queue_find_name(info->name);
1645 	if (q == NULL)
1646 		return -EINVAL;
1647 	info->queue = q->queue;
1648 	info->owner = q->owner;
1649 	info->locked = q->locked;
1650 	queuefree(q);
1651 
1652 	return 0;
1653 }
1654 
1655 /* GET_QUEUE_STATUS ioctl() */
1656 static int snd_seq_ioctl_get_queue_status(struct snd_seq_client *client,
1657 					  void *arg)
1658 {
1659 	struct snd_seq_queue_status *status = arg;
1660 	struct snd_seq_queue *queue;
1661 	struct snd_seq_timer *tmr;
1662 
1663 	queue = queueptr(status->queue);
1664 	if (queue == NULL)
1665 		return -EINVAL;
1666 	memset(status, 0, sizeof(*status));
1667 	status->queue = queue->queue;
1668 
1669 	tmr = queue->timer;
1670 	status->events = queue->tickq->cells + queue->timeq->cells;
1671 
1672 	status->time = snd_seq_timer_get_cur_time(tmr, true);
1673 	status->tick = snd_seq_timer_get_cur_tick(tmr);
1674 
1675 	status->running = tmr->running;
1676 
1677 	status->flags = queue->flags;
1678 	queuefree(queue);
1679 
1680 	return 0;
1681 }
1682 
1683 
1684 /* GET_QUEUE_TEMPO ioctl() */
1685 static int snd_seq_ioctl_get_queue_tempo(struct snd_seq_client *client,
1686 					 void *arg)
1687 {
1688 	struct snd_seq_queue_tempo *tempo = arg;
1689 	struct snd_seq_queue *queue;
1690 	struct snd_seq_timer *tmr;
1691 
1692 	queue = queueptr(tempo->queue);
1693 	if (queue == NULL)
1694 		return -EINVAL;
1695 	memset(tempo, 0, sizeof(*tempo));
1696 	tempo->queue = queue->queue;
1697 
1698 	tmr = queue->timer;
1699 
1700 	tempo->tempo = tmr->tempo;
1701 	tempo->ppq = tmr->ppq;
1702 	tempo->skew_value = tmr->skew;
1703 	tempo->skew_base = tmr->skew_base;
1704 	queuefree(queue);
1705 
1706 	return 0;
1707 }
1708 
1709 
1710 /* SET_QUEUE_TEMPO ioctl() */
1711 int snd_seq_set_queue_tempo(int client, struct snd_seq_queue_tempo *tempo)
1712 {
1713 	if (!snd_seq_queue_check_access(tempo->queue, client))
1714 		return -EPERM;
1715 	return snd_seq_queue_timer_set_tempo(tempo->queue, client, tempo);
1716 }
1717 EXPORT_SYMBOL(snd_seq_set_queue_tempo);
1718 
1719 static int snd_seq_ioctl_set_queue_tempo(struct snd_seq_client *client,
1720 					 void *arg)
1721 {
1722 	struct snd_seq_queue_tempo *tempo = arg;
1723 	int result;
1724 
1725 	result = snd_seq_set_queue_tempo(client->number, tempo);
1726 	return result < 0 ? result : 0;
1727 }
1728 
1729 
1730 /* GET_QUEUE_TIMER ioctl() */
1731 static int snd_seq_ioctl_get_queue_timer(struct snd_seq_client *client,
1732 					 void *arg)
1733 {
1734 	struct snd_seq_queue_timer *timer = arg;
1735 	struct snd_seq_queue *queue;
1736 	struct snd_seq_timer *tmr;
1737 
1738 	queue = queueptr(timer->queue);
1739 	if (queue == NULL)
1740 		return -EINVAL;
1741 
1742 	mutex_lock(&queue->timer_mutex);
1743 	tmr = queue->timer;
1744 	memset(timer, 0, sizeof(*timer));
1745 	timer->queue = queue->queue;
1746 
1747 	timer->type = tmr->type;
1748 	if (tmr->type == SNDRV_SEQ_TIMER_ALSA) {
1749 		timer->u.alsa.id = tmr->alsa_id;
1750 		timer->u.alsa.resolution = tmr->preferred_resolution;
1751 	}
1752 	mutex_unlock(&queue->timer_mutex);
1753 	queuefree(queue);
1754 
1755 	return 0;
1756 }
1757 
1758 
1759 /* SET_QUEUE_TIMER ioctl() */
1760 static int snd_seq_ioctl_set_queue_timer(struct snd_seq_client *client,
1761 					 void *arg)
1762 {
1763 	struct snd_seq_queue_timer *timer = arg;
1764 	int result = 0;
1765 
1766 	if (timer->type != SNDRV_SEQ_TIMER_ALSA)
1767 		return -EINVAL;
1768 
1769 	if (snd_seq_queue_check_access(timer->queue, client->number)) {
1770 		struct snd_seq_queue *q;
1771 		struct snd_seq_timer *tmr;
1772 
1773 		q = queueptr(timer->queue);
1774 		if (q == NULL)
1775 			return -ENXIO;
1776 		mutex_lock(&q->timer_mutex);
1777 		tmr = q->timer;
1778 		snd_seq_queue_timer_close(timer->queue);
1779 		tmr->type = timer->type;
1780 		if (tmr->type == SNDRV_SEQ_TIMER_ALSA) {
1781 			tmr->alsa_id = timer->u.alsa.id;
1782 			tmr->preferred_resolution = timer->u.alsa.resolution;
1783 		}
1784 		result = snd_seq_queue_timer_open(timer->queue);
1785 		mutex_unlock(&q->timer_mutex);
1786 		queuefree(q);
1787 	} else {
1788 		return -EPERM;
1789 	}
1790 
1791 	return result;
1792 }
1793 
1794 
1795 /* GET_QUEUE_CLIENT ioctl() */
1796 static int snd_seq_ioctl_get_queue_client(struct snd_seq_client *client,
1797 					  void *arg)
1798 {
1799 	struct snd_seq_queue_client *info = arg;
1800 	int used;
1801 
1802 	used = snd_seq_queue_is_used(info->queue, client->number);
1803 	if (used < 0)
1804 		return -EINVAL;
1805 	info->used = used;
1806 	info->client = client->number;
1807 
1808 	return 0;
1809 }
1810 
1811 
1812 /* SET_QUEUE_CLIENT ioctl() */
1813 static int snd_seq_ioctl_set_queue_client(struct snd_seq_client *client,
1814 					  void *arg)
1815 {
1816 	struct snd_seq_queue_client *info = arg;
1817 	int err;
1818 
1819 	if (info->used >= 0) {
1820 		err = snd_seq_queue_use(info->queue, client->number, info->used);
1821 		if (err < 0)
1822 			return err;
1823 	}
1824 
1825 	return snd_seq_ioctl_get_queue_client(client, arg);
1826 }
1827 
1828 
1829 /* GET_CLIENT_POOL ioctl() */
1830 static int snd_seq_ioctl_get_client_pool(struct snd_seq_client *client,
1831 					 void *arg)
1832 {
1833 	struct snd_seq_client_pool *info = arg;
1834 	struct snd_seq_client *cptr;
1835 
1836 	cptr = snd_seq_client_use_ptr(info->client);
1837 	if (cptr == NULL)
1838 		return -ENOENT;
1839 	memset(info, 0, sizeof(*info));
1840 	info->client = cptr->number;
1841 	info->output_pool = cptr->pool->size;
1842 	info->output_room = cptr->pool->room;
1843 	info->output_free = info->output_pool;
1844 	info->output_free = snd_seq_unused_cells(cptr->pool);
1845 	if (cptr->type == USER_CLIENT) {
1846 		info->input_pool = cptr->data.user.fifo_pool_size;
1847 		info->input_free = info->input_pool;
1848 		info->input_free = snd_seq_fifo_unused_cells(cptr->data.user.fifo);
1849 	} else {
1850 		info->input_pool = 0;
1851 		info->input_free = 0;
1852 	}
1853 	snd_seq_client_unlock(cptr);
1854 
1855 	return 0;
1856 }
1857 
1858 /* SET_CLIENT_POOL ioctl() */
1859 static int snd_seq_ioctl_set_client_pool(struct snd_seq_client *client,
1860 					 void *arg)
1861 {
1862 	struct snd_seq_client_pool *info = arg;
1863 	int rc;
1864 
1865 	if (client->number != info->client)
1866 		return -EINVAL; /* can't change other clients */
1867 
1868 	if (info->output_pool >= 1 && info->output_pool <= SNDRV_SEQ_MAX_EVENTS &&
1869 	    (! snd_seq_write_pool_allocated(client) ||
1870 	     info->output_pool != client->pool->size)) {
1871 		if (snd_seq_write_pool_allocated(client)) {
1872 			/* is the pool in use? */
1873 			if (atomic_read(&client->pool->counter))
1874 				return -EBUSY;
1875 			/* remove all existing cells */
1876 			snd_seq_pool_mark_closing(client->pool);
1877 			snd_seq_pool_done(client->pool);
1878 		}
1879 		client->pool->size = info->output_pool;
1880 		rc = snd_seq_pool_init(client->pool);
1881 		if (rc < 0)
1882 			return rc;
1883 	}
1884 	if (client->type == USER_CLIENT && client->data.user.fifo != NULL &&
1885 	    info->input_pool >= 1 &&
1886 	    info->input_pool <= SNDRV_SEQ_MAX_CLIENT_EVENTS &&
1887 	    info->input_pool != client->data.user.fifo_pool_size) {
1888 		/* change pool size */
1889 		rc = snd_seq_fifo_resize(client->data.user.fifo, info->input_pool);
1890 		if (rc < 0)
1891 			return rc;
1892 		client->data.user.fifo_pool_size = info->input_pool;
1893 	}
1894 	if (info->output_room >= 1 &&
1895 	    info->output_room <= client->pool->size) {
1896 		client->pool->room  = info->output_room;
1897 	}
1898 
1899 	return snd_seq_ioctl_get_client_pool(client, arg);
1900 }
1901 
1902 
1903 /* REMOVE_EVENTS ioctl() */
1904 static int snd_seq_ioctl_remove_events(struct snd_seq_client *client,
1905 				       void *arg)
1906 {
1907 	struct snd_seq_remove_events *info = arg;
1908 
1909 	/*
1910 	 * Input mostly not implemented XXX.
1911 	 */
1912 	if (info->remove_mode & SNDRV_SEQ_REMOVE_INPUT) {
1913 		/*
1914 		 * No restrictions so for a user client we can clear
1915 		 * the whole fifo
1916 		 */
1917 		if (client->type == USER_CLIENT && client->data.user.fifo)
1918 			snd_seq_fifo_clear(client->data.user.fifo);
1919 	}
1920 
1921 	if (info->remove_mode & SNDRV_SEQ_REMOVE_OUTPUT)
1922 		snd_seq_queue_remove_cells(client->number, info);
1923 
1924 	return 0;
1925 }
1926 
1927 
1928 /*
1929  * get subscription info
1930  */
1931 static int snd_seq_ioctl_get_subscription(struct snd_seq_client *client,
1932 					  void *arg)
1933 {
1934 	struct snd_seq_port_subscribe *subs = arg;
1935 	int result;
1936 	struct snd_seq_client *sender = NULL;
1937 	struct snd_seq_client_port *sport = NULL;
1938 
1939 	result = -EINVAL;
1940 	sender = snd_seq_client_use_ptr(subs->sender.client);
1941 	if (!sender)
1942 		goto __end;
1943 	sport = snd_seq_port_use_ptr(sender, subs->sender.port);
1944 	if (!sport)
1945 		goto __end;
1946 	result = snd_seq_port_get_subscription(&sport->c_src, &subs->dest,
1947 					       subs);
1948       __end:
1949       	if (sport)
1950 		snd_seq_port_unlock(sport);
1951 	if (sender)
1952 		snd_seq_client_unlock(sender);
1953 
1954 	return result;
1955 }
1956 
1957 
1958 /*
1959  * get subscription info - check only its presence
1960  */
1961 static int snd_seq_ioctl_query_subs(struct snd_seq_client *client, void *arg)
1962 {
1963 	struct snd_seq_query_subs *subs = arg;
1964 	int result = -ENXIO;
1965 	struct snd_seq_client *cptr = NULL;
1966 	struct snd_seq_client_port *port = NULL;
1967 	struct snd_seq_port_subs_info *group;
1968 	struct list_head *p;
1969 	int i;
1970 
1971 	cptr = snd_seq_client_use_ptr(subs->root.client);
1972 	if (!cptr)
1973 		goto __end;
1974 	port = snd_seq_port_use_ptr(cptr, subs->root.port);
1975 	if (!port)
1976 		goto __end;
1977 
1978 	switch (subs->type) {
1979 	case SNDRV_SEQ_QUERY_SUBS_READ:
1980 		group = &port->c_src;
1981 		break;
1982 	case SNDRV_SEQ_QUERY_SUBS_WRITE:
1983 		group = &port->c_dest;
1984 		break;
1985 	default:
1986 		goto __end;
1987 	}
1988 
1989 	down_read(&group->list_mutex);
1990 	/* search for the subscriber */
1991 	subs->num_subs = group->count;
1992 	i = 0;
1993 	result = -ENOENT;
1994 	list_for_each(p, &group->list_head) {
1995 		if (i++ == subs->index) {
1996 			/* found! */
1997 			struct snd_seq_subscribers *s;
1998 			if (subs->type == SNDRV_SEQ_QUERY_SUBS_READ) {
1999 				s = list_entry(p, struct snd_seq_subscribers, src_list);
2000 				subs->addr = s->info.dest;
2001 			} else {
2002 				s = list_entry(p, struct snd_seq_subscribers, dest_list);
2003 				subs->addr = s->info.sender;
2004 			}
2005 			subs->flags = s->info.flags;
2006 			subs->queue = s->info.queue;
2007 			result = 0;
2008 			break;
2009 		}
2010 	}
2011 	up_read(&group->list_mutex);
2012 
2013       __end:
2014    	if (port)
2015 		snd_seq_port_unlock(port);
2016 	if (cptr)
2017 		snd_seq_client_unlock(cptr);
2018 
2019 	return result;
2020 }
2021 
2022 
2023 /*
2024  * query next client
2025  */
2026 static int snd_seq_ioctl_query_next_client(struct snd_seq_client *client,
2027 					   void *arg)
2028 {
2029 	struct snd_seq_client_info *info = arg;
2030 	struct snd_seq_client *cptr = NULL;
2031 
2032 	/* search for next client */
2033 	if (info->client < INT_MAX)
2034 		info->client++;
2035 	if (info->client < 0)
2036 		info->client = 0;
2037 	for (; info->client < SNDRV_SEQ_MAX_CLIENTS; info->client++) {
2038 		cptr = snd_seq_client_use_ptr(info->client);
2039 		if (cptr)
2040 			break; /* found */
2041 	}
2042 	if (cptr == NULL)
2043 		return -ENOENT;
2044 
2045 	get_client_info(cptr, info);
2046 	snd_seq_client_unlock(cptr);
2047 
2048 	return 0;
2049 }
2050 
2051 /*
2052  * query next port
2053  */
2054 static int snd_seq_ioctl_query_next_port(struct snd_seq_client *client,
2055 					 void *arg)
2056 {
2057 	struct snd_seq_port_info *info = arg;
2058 	struct snd_seq_client *cptr;
2059 	struct snd_seq_client_port *port = NULL;
2060 
2061 	cptr = snd_seq_client_use_ptr(info->addr.client);
2062 	if (cptr == NULL)
2063 		return -ENXIO;
2064 
2065 	/* search for next port */
2066 	info->addr.port++;
2067 	port = snd_seq_port_query_nearest(cptr, info);
2068 	if (port == NULL) {
2069 		snd_seq_client_unlock(cptr);
2070 		return -ENOENT;
2071 	}
2072 
2073 	/* get port info */
2074 	info->addr = port->addr;
2075 	snd_seq_get_port_info(port, info);
2076 	snd_seq_port_unlock(port);
2077 	snd_seq_client_unlock(cptr);
2078 
2079 	return 0;
2080 }
2081 
2082 /* -------------------------------------------------------- */
2083 
2084 static const struct ioctl_handler {
2085 	unsigned int cmd;
2086 	int (*func)(struct snd_seq_client *client, void *arg);
2087 } ioctl_handlers[] = {
2088 	{ SNDRV_SEQ_IOCTL_PVERSION, snd_seq_ioctl_pversion },
2089 	{ SNDRV_SEQ_IOCTL_CLIENT_ID, snd_seq_ioctl_client_id },
2090 	{ SNDRV_SEQ_IOCTL_SYSTEM_INFO, snd_seq_ioctl_system_info },
2091 	{ SNDRV_SEQ_IOCTL_RUNNING_MODE, snd_seq_ioctl_running_mode },
2092 	{ SNDRV_SEQ_IOCTL_GET_CLIENT_INFO, snd_seq_ioctl_get_client_info },
2093 	{ SNDRV_SEQ_IOCTL_SET_CLIENT_INFO, snd_seq_ioctl_set_client_info },
2094 	{ SNDRV_SEQ_IOCTL_CREATE_PORT, snd_seq_ioctl_create_port },
2095 	{ SNDRV_SEQ_IOCTL_DELETE_PORT, snd_seq_ioctl_delete_port },
2096 	{ SNDRV_SEQ_IOCTL_GET_PORT_INFO, snd_seq_ioctl_get_port_info },
2097 	{ SNDRV_SEQ_IOCTL_SET_PORT_INFO, snd_seq_ioctl_set_port_info },
2098 	{ SNDRV_SEQ_IOCTL_SUBSCRIBE_PORT, snd_seq_ioctl_subscribe_port },
2099 	{ SNDRV_SEQ_IOCTL_UNSUBSCRIBE_PORT, snd_seq_ioctl_unsubscribe_port },
2100 	{ SNDRV_SEQ_IOCTL_CREATE_QUEUE, snd_seq_ioctl_create_queue },
2101 	{ SNDRV_SEQ_IOCTL_DELETE_QUEUE, snd_seq_ioctl_delete_queue },
2102 	{ SNDRV_SEQ_IOCTL_GET_QUEUE_INFO, snd_seq_ioctl_get_queue_info },
2103 	{ SNDRV_SEQ_IOCTL_SET_QUEUE_INFO, snd_seq_ioctl_set_queue_info },
2104 	{ SNDRV_SEQ_IOCTL_GET_NAMED_QUEUE, snd_seq_ioctl_get_named_queue },
2105 	{ SNDRV_SEQ_IOCTL_GET_QUEUE_STATUS, snd_seq_ioctl_get_queue_status },
2106 	{ SNDRV_SEQ_IOCTL_GET_QUEUE_TEMPO, snd_seq_ioctl_get_queue_tempo },
2107 	{ SNDRV_SEQ_IOCTL_SET_QUEUE_TEMPO, snd_seq_ioctl_set_queue_tempo },
2108 	{ SNDRV_SEQ_IOCTL_GET_QUEUE_TIMER, snd_seq_ioctl_get_queue_timer },
2109 	{ SNDRV_SEQ_IOCTL_SET_QUEUE_TIMER, snd_seq_ioctl_set_queue_timer },
2110 	{ SNDRV_SEQ_IOCTL_GET_QUEUE_CLIENT, snd_seq_ioctl_get_queue_client },
2111 	{ SNDRV_SEQ_IOCTL_SET_QUEUE_CLIENT, snd_seq_ioctl_set_queue_client },
2112 	{ SNDRV_SEQ_IOCTL_GET_CLIENT_POOL, snd_seq_ioctl_get_client_pool },
2113 	{ SNDRV_SEQ_IOCTL_SET_CLIENT_POOL, snd_seq_ioctl_set_client_pool },
2114 	{ SNDRV_SEQ_IOCTL_GET_SUBSCRIPTION, snd_seq_ioctl_get_subscription },
2115 	{ SNDRV_SEQ_IOCTL_QUERY_NEXT_CLIENT, snd_seq_ioctl_query_next_client },
2116 	{ SNDRV_SEQ_IOCTL_QUERY_NEXT_PORT, snd_seq_ioctl_query_next_port },
2117 	{ SNDRV_SEQ_IOCTL_REMOVE_EVENTS, snd_seq_ioctl_remove_events },
2118 	{ SNDRV_SEQ_IOCTL_QUERY_SUBS, snd_seq_ioctl_query_subs },
2119 	{ 0, NULL },
2120 };
2121 
2122 static long snd_seq_ioctl(struct file *file, unsigned int cmd,
2123 			  unsigned long arg)
2124 {
2125 	struct snd_seq_client *client = file->private_data;
2126 	/* To use kernel stack for ioctl data. */
2127 	union {
2128 		int pversion;
2129 		int client_id;
2130 		struct snd_seq_system_info	system_info;
2131 		struct snd_seq_running_info	running_info;
2132 		struct snd_seq_client_info	client_info;
2133 		struct snd_seq_port_info	port_info;
2134 		struct snd_seq_port_subscribe	port_subscribe;
2135 		struct snd_seq_queue_info	queue_info;
2136 		struct snd_seq_queue_status	queue_status;
2137 		struct snd_seq_queue_tempo	tempo;
2138 		struct snd_seq_queue_timer	queue_timer;
2139 		struct snd_seq_queue_client	queue_client;
2140 		struct snd_seq_client_pool	client_pool;
2141 		struct snd_seq_remove_events	remove_events;
2142 		struct snd_seq_query_subs	query_subs;
2143 	} buf;
2144 	const struct ioctl_handler *handler;
2145 	unsigned long size;
2146 	int err;
2147 
2148 	if (snd_BUG_ON(!client))
2149 		return -ENXIO;
2150 
2151 	for (handler = ioctl_handlers; handler->cmd > 0; ++handler) {
2152 		if (handler->cmd == cmd)
2153 			break;
2154 	}
2155 	if (handler->cmd == 0)
2156 		return -ENOTTY;
2157 
2158 	memset(&buf, 0, sizeof(buf));
2159 
2160 	/*
2161 	 * All of ioctl commands for ALSA sequencer get an argument of size
2162 	 * within 13 bits. We can safely pick up the size from the command.
2163 	 */
2164 	size = _IOC_SIZE(handler->cmd);
2165 	if (handler->cmd & IOC_IN) {
2166 		if (copy_from_user(&buf, (const void __user *)arg, size))
2167 			return -EFAULT;
2168 	}
2169 
2170 	mutex_lock(&client->ioctl_mutex);
2171 	err = handler->func(client, &buf);
2172 	mutex_unlock(&client->ioctl_mutex);
2173 	if (err >= 0) {
2174 		/* Some commands includes a bug in 'dir' field. */
2175 		if (handler->cmd == SNDRV_SEQ_IOCTL_SET_QUEUE_CLIENT ||
2176 		    handler->cmd == SNDRV_SEQ_IOCTL_SET_CLIENT_POOL ||
2177 		    (handler->cmd & IOC_OUT))
2178 			if (copy_to_user((void __user *)arg, &buf, size))
2179 				return -EFAULT;
2180 	}
2181 
2182 	return err;
2183 }
2184 
2185 #ifdef CONFIG_COMPAT
2186 #include "seq_compat.c"
2187 #else
2188 #define snd_seq_ioctl_compat	NULL
2189 #endif
2190 
2191 /* -------------------------------------------------------- */
2192 
2193 
2194 /* exported to kernel modules */
2195 int snd_seq_create_kernel_client(struct snd_card *card, int client_index,
2196 				 const char *name_fmt, ...)
2197 {
2198 	struct snd_seq_client *client;
2199 	va_list args;
2200 
2201 	if (snd_BUG_ON(in_interrupt()))
2202 		return -EBUSY;
2203 
2204 	if (card && client_index >= SNDRV_SEQ_CLIENTS_PER_CARD)
2205 		return -EINVAL;
2206 	if (card == NULL && client_index >= SNDRV_SEQ_GLOBAL_CLIENTS)
2207 		return -EINVAL;
2208 
2209 	mutex_lock(&register_mutex);
2210 
2211 	if (card) {
2212 		client_index += SNDRV_SEQ_GLOBAL_CLIENTS
2213 			+ card->number * SNDRV_SEQ_CLIENTS_PER_CARD;
2214 		if (client_index >= SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN)
2215 			client_index = -1;
2216 	}
2217 
2218 	/* empty write queue as default */
2219 	client = seq_create_client1(client_index, 0);
2220 	if (client == NULL) {
2221 		mutex_unlock(&register_mutex);
2222 		return -EBUSY;	/* failure code */
2223 	}
2224 	usage_alloc(&client_usage, 1);
2225 
2226 	client->accept_input = 1;
2227 	client->accept_output = 1;
2228 	client->data.kernel.card = card;
2229 
2230 	va_start(args, name_fmt);
2231 	vsnprintf(client->name, sizeof(client->name), name_fmt, args);
2232 	va_end(args);
2233 
2234 	client->type = KERNEL_CLIENT;
2235 	mutex_unlock(&register_mutex);
2236 
2237 	/* make others aware this new client */
2238 	snd_seq_system_client_ev_client_start(client->number);
2239 
2240 	/* return client number to caller */
2241 	return client->number;
2242 }
2243 EXPORT_SYMBOL(snd_seq_create_kernel_client);
2244 
2245 /* exported to kernel modules */
2246 int snd_seq_delete_kernel_client(int client)
2247 {
2248 	struct snd_seq_client *ptr;
2249 
2250 	if (snd_BUG_ON(in_interrupt()))
2251 		return -EBUSY;
2252 
2253 	ptr = clientptr(client);
2254 	if (ptr == NULL)
2255 		return -EINVAL;
2256 
2257 	seq_free_client(ptr);
2258 	kfree(ptr);
2259 	return 0;
2260 }
2261 EXPORT_SYMBOL(snd_seq_delete_kernel_client);
2262 
2263 /*
2264  * exported, called by kernel clients to enqueue events (w/o blocking)
2265  *
2266  * RETURN VALUE: zero if succeed, negative if error
2267  */
2268 int snd_seq_kernel_client_enqueue(int client, struct snd_seq_event *ev,
2269 				  struct file *file, bool blocking)
2270 {
2271 	struct snd_seq_client *cptr;
2272 	int result;
2273 
2274 	if (snd_BUG_ON(!ev))
2275 		return -EINVAL;
2276 
2277 	if (ev->type == SNDRV_SEQ_EVENT_NONE)
2278 		return 0; /* ignore this */
2279 	if (ev->type == SNDRV_SEQ_EVENT_KERNEL_ERROR)
2280 		return -EINVAL; /* quoted events can't be enqueued */
2281 
2282 	/* fill in client number */
2283 	ev->source.client = client;
2284 
2285 	if (check_event_type_and_length(ev))
2286 		return -EINVAL;
2287 
2288 	cptr = snd_seq_client_use_ptr(client);
2289 	if (cptr == NULL)
2290 		return -EINVAL;
2291 
2292 	if (!cptr->accept_output) {
2293 		result = -EPERM;
2294 	} else { /* send it */
2295 		mutex_lock(&cptr->ioctl_mutex);
2296 		result = snd_seq_client_enqueue_event(cptr, ev, file, blocking,
2297 						      false, 0,
2298 						      &cptr->ioctl_mutex);
2299 		mutex_unlock(&cptr->ioctl_mutex);
2300 	}
2301 
2302 	snd_seq_client_unlock(cptr);
2303 	return result;
2304 }
2305 EXPORT_SYMBOL(snd_seq_kernel_client_enqueue);
2306 
2307 /*
2308  * exported, called by kernel clients to dispatch events directly to other
2309  * clients, bypassing the queues.  Event time-stamp will be updated.
2310  *
2311  * RETURN VALUE: negative = delivery failed,
2312  *		 zero, or positive: the number of delivered events
2313  */
2314 int snd_seq_kernel_client_dispatch(int client, struct snd_seq_event * ev,
2315 				   int atomic, int hop)
2316 {
2317 	struct snd_seq_client *cptr;
2318 	int result;
2319 
2320 	if (snd_BUG_ON(!ev))
2321 		return -EINVAL;
2322 
2323 	/* fill in client number */
2324 	ev->queue = SNDRV_SEQ_QUEUE_DIRECT;
2325 	ev->source.client = client;
2326 
2327 	if (check_event_type_and_length(ev))
2328 		return -EINVAL;
2329 
2330 	cptr = snd_seq_client_use_ptr(client);
2331 	if (cptr == NULL)
2332 		return -EINVAL;
2333 
2334 	if (!cptr->accept_output)
2335 		result = -EPERM;
2336 	else
2337 		result = snd_seq_deliver_event(cptr, ev, atomic, hop);
2338 
2339 	snd_seq_client_unlock(cptr);
2340 	return result;
2341 }
2342 EXPORT_SYMBOL(snd_seq_kernel_client_dispatch);
2343 
2344 /**
2345  * snd_seq_kernel_client_ctl - operate a command for a client with data in
2346  *			       kernel space.
2347  * @clientid:	A numerical ID for a client.
2348  * @cmd:	An ioctl(2) command for ALSA sequencer operation.
2349  * @arg:	A pointer to data in kernel space.
2350  *
2351  * Against its name, both kernel/application client can be handled by this
2352  * kernel API. A pointer of 'arg' argument should be in kernel space.
2353  *
2354  * Return: 0 at success. Negative error code at failure.
2355  */
2356 int snd_seq_kernel_client_ctl(int clientid, unsigned int cmd, void *arg)
2357 {
2358 	const struct ioctl_handler *handler;
2359 	struct snd_seq_client *client;
2360 
2361 	client = clientptr(clientid);
2362 	if (client == NULL)
2363 		return -ENXIO;
2364 
2365 	for (handler = ioctl_handlers; handler->cmd > 0; ++handler) {
2366 		if (handler->cmd == cmd)
2367 			return handler->func(client, arg);
2368 	}
2369 
2370 	pr_debug("ALSA: seq unknown ioctl() 0x%x (type='%c', number=0x%02x)\n",
2371 		 cmd, _IOC_TYPE(cmd), _IOC_NR(cmd));
2372 	return -ENOTTY;
2373 }
2374 EXPORT_SYMBOL(snd_seq_kernel_client_ctl);
2375 
2376 /* exported (for OSS emulator) */
2377 int snd_seq_kernel_client_write_poll(int clientid, struct file *file, poll_table *wait)
2378 {
2379 	struct snd_seq_client *client;
2380 
2381 	client = clientptr(clientid);
2382 	if (client == NULL)
2383 		return -ENXIO;
2384 
2385 	if (! snd_seq_write_pool_allocated(client))
2386 		return 1;
2387 	if (snd_seq_pool_poll_wait(client->pool, file, wait))
2388 		return 1;
2389 	return 0;
2390 }
2391 EXPORT_SYMBOL(snd_seq_kernel_client_write_poll);
2392 
2393 /*---------------------------------------------------------------------------*/
2394 
2395 #ifdef CONFIG_SND_PROC_FS
2396 /*
2397  *  /proc interface
2398  */
2399 static void snd_seq_info_dump_subscribers(struct snd_info_buffer *buffer,
2400 					  struct snd_seq_port_subs_info *group,
2401 					  int is_src, char *msg)
2402 {
2403 	struct list_head *p;
2404 	struct snd_seq_subscribers *s;
2405 	int count = 0;
2406 
2407 	down_read(&group->list_mutex);
2408 	if (list_empty(&group->list_head)) {
2409 		up_read(&group->list_mutex);
2410 		return;
2411 	}
2412 	snd_iprintf(buffer, msg);
2413 	list_for_each(p, &group->list_head) {
2414 		if (is_src)
2415 			s = list_entry(p, struct snd_seq_subscribers, src_list);
2416 		else
2417 			s = list_entry(p, struct snd_seq_subscribers, dest_list);
2418 		if (count++)
2419 			snd_iprintf(buffer, ", ");
2420 		snd_iprintf(buffer, "%d:%d",
2421 			    is_src ? s->info.dest.client : s->info.sender.client,
2422 			    is_src ? s->info.dest.port : s->info.sender.port);
2423 		if (s->info.flags & SNDRV_SEQ_PORT_SUBS_TIMESTAMP)
2424 			snd_iprintf(buffer, "[%c:%d]", ((s->info.flags & SNDRV_SEQ_PORT_SUBS_TIME_REAL) ? 'r' : 't'), s->info.queue);
2425 		if (group->exclusive)
2426 			snd_iprintf(buffer, "[ex]");
2427 	}
2428 	up_read(&group->list_mutex);
2429 	snd_iprintf(buffer, "\n");
2430 }
2431 
2432 #define FLAG_PERM_RD(perm) ((perm) & SNDRV_SEQ_PORT_CAP_READ ? ((perm) & SNDRV_SEQ_PORT_CAP_SUBS_READ ? 'R' : 'r') : '-')
2433 #define FLAG_PERM_WR(perm) ((perm) & SNDRV_SEQ_PORT_CAP_WRITE ? ((perm) & SNDRV_SEQ_PORT_CAP_SUBS_WRITE ? 'W' : 'w') : '-')
2434 #define FLAG_PERM_EX(perm) ((perm) & SNDRV_SEQ_PORT_CAP_NO_EXPORT ? '-' : 'e')
2435 
2436 #define FLAG_PERM_DUPLEX(perm) ((perm) & SNDRV_SEQ_PORT_CAP_DUPLEX ? 'X' : '-')
2437 
2438 static void snd_seq_info_dump_ports(struct snd_info_buffer *buffer,
2439 				    struct snd_seq_client *client)
2440 {
2441 	struct snd_seq_client_port *p;
2442 
2443 	mutex_lock(&client->ports_mutex);
2444 	list_for_each_entry(p, &client->ports_list_head, list) {
2445 		snd_iprintf(buffer, "  Port %3d : \"%s\" (%c%c%c%c)\n",
2446 			    p->addr.port, p->name,
2447 			    FLAG_PERM_RD(p->capability),
2448 			    FLAG_PERM_WR(p->capability),
2449 			    FLAG_PERM_EX(p->capability),
2450 			    FLAG_PERM_DUPLEX(p->capability));
2451 		snd_seq_info_dump_subscribers(buffer, &p->c_src, 1, "    Connecting To: ");
2452 		snd_seq_info_dump_subscribers(buffer, &p->c_dest, 0, "    Connected From: ");
2453 	}
2454 	mutex_unlock(&client->ports_mutex);
2455 }
2456 
2457 
2458 /* exported to seq_info.c */
2459 void snd_seq_info_clients_read(struct snd_info_entry *entry,
2460 			       struct snd_info_buffer *buffer)
2461 {
2462 	int c;
2463 	struct snd_seq_client *client;
2464 
2465 	snd_iprintf(buffer, "Client info\n");
2466 	snd_iprintf(buffer, "  cur  clients : %d\n", client_usage.cur);
2467 	snd_iprintf(buffer, "  peak clients : %d\n", client_usage.peak);
2468 	snd_iprintf(buffer, "  max  clients : %d\n", SNDRV_SEQ_MAX_CLIENTS);
2469 	snd_iprintf(buffer, "\n");
2470 
2471 	/* list the client table */
2472 	for (c = 0; c < SNDRV_SEQ_MAX_CLIENTS; c++) {
2473 		client = snd_seq_client_use_ptr(c);
2474 		if (client == NULL)
2475 			continue;
2476 		if (client->type == NO_CLIENT) {
2477 			snd_seq_client_unlock(client);
2478 			continue;
2479 		}
2480 
2481 		snd_iprintf(buffer, "Client %3d : \"%s\" [%s]\n",
2482 			    c, client->name,
2483 			    client->type == USER_CLIENT ? "User" : "Kernel");
2484 		snd_seq_info_dump_ports(buffer, client);
2485 		if (snd_seq_write_pool_allocated(client)) {
2486 			snd_iprintf(buffer, "  Output pool :\n");
2487 			snd_seq_info_pool(buffer, client->pool, "    ");
2488 		}
2489 		if (client->type == USER_CLIENT && client->data.user.fifo &&
2490 		    client->data.user.fifo->pool) {
2491 			snd_iprintf(buffer, "  Input pool :\n");
2492 			snd_seq_info_pool(buffer, client->data.user.fifo->pool, "    ");
2493 		}
2494 		snd_seq_client_unlock(client);
2495 	}
2496 }
2497 #endif /* CONFIG_SND_PROC_FS */
2498 
2499 /*---------------------------------------------------------------------------*/
2500 
2501 
2502 /*
2503  *  REGISTRATION PART
2504  */
2505 
2506 static const struct file_operations snd_seq_f_ops =
2507 {
2508 	.owner =	THIS_MODULE,
2509 	.read =		snd_seq_read,
2510 	.write =	snd_seq_write,
2511 	.open =		snd_seq_open,
2512 	.release =	snd_seq_release,
2513 	.llseek =	no_llseek,
2514 	.poll =		snd_seq_poll,
2515 	.unlocked_ioctl =	snd_seq_ioctl,
2516 	.compat_ioctl =	snd_seq_ioctl_compat,
2517 };
2518 
2519 static struct device seq_dev;
2520 
2521 /*
2522  * register sequencer device
2523  */
2524 int __init snd_sequencer_device_init(void)
2525 {
2526 	int err;
2527 
2528 	snd_device_initialize(&seq_dev, NULL);
2529 	dev_set_name(&seq_dev, "seq");
2530 
2531 	mutex_lock(&register_mutex);
2532 	err = snd_register_device(SNDRV_DEVICE_TYPE_SEQUENCER, NULL, 0,
2533 				  &snd_seq_f_ops, NULL, &seq_dev);
2534 	mutex_unlock(&register_mutex);
2535 	if (err < 0) {
2536 		put_device(&seq_dev);
2537 		return err;
2538 	}
2539 
2540 	return 0;
2541 }
2542 
2543 
2544 
2545 /*
2546  * unregister sequencer device
2547  */
2548 void snd_sequencer_device_done(void)
2549 {
2550 	snd_unregister_device(&seq_dev);
2551 	put_device(&seq_dev);
2552 }
2553