xref: /openbmc/linux/sound/core/seq/seq_clientmgr.c (revision c2cd9d04)
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 char client_requested[SNDRV_SEQ_GLOBAL_CLIENTS];
125 		static char card_requested[SNDRV_CARDS];
126 		if (clientid < SNDRV_SEQ_GLOBAL_CLIENTS) {
127 			int idx;
128 
129 			if (!client_requested[clientid]) {
130 				client_requested[clientid] = 1;
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 (! card_requested[card]) {
146 					card_requested[card] = 1;
147 					snd_request_card(card);
148 				}
149 				snd_seq_device_load_drivers();
150 			}
151 		}
152 		spin_lock_irqsave(&clients_lock, flags);
153 		client = clientptr(clientid);
154 		if (client)
155 			goto __lock;
156 		spin_unlock_irqrestore(&clients_lock, flags);
157 	}
158 #endif
159 	return NULL;
160 
161       __lock:
162 	snd_use_lock_use(&client->use_lock);
163 	spin_unlock_irqrestore(&clients_lock, flags);
164 	return client;
165 }
166 
167 /* Take refcount and perform ioctl_mutex lock on the given client;
168  * used only for OSS sequencer
169  * Unlock via snd_seq_client_ioctl_unlock() below
170  */
171 bool snd_seq_client_ioctl_lock(int clientid)
172 {
173 	struct snd_seq_client *client;
174 
175 	client = snd_seq_client_use_ptr(clientid);
176 	if (!client)
177 		return false;
178 	mutex_lock(&client->ioctl_mutex);
179 	/* The client isn't unrefed here; see snd_seq_client_ioctl_unlock() */
180 	return true;
181 }
182 EXPORT_SYMBOL_GPL(snd_seq_client_ioctl_lock);
183 
184 /* Unlock and unref the given client; for OSS sequencer use only */
185 void snd_seq_client_ioctl_unlock(int clientid)
186 {
187 	struct snd_seq_client *client;
188 
189 	client = snd_seq_client_use_ptr(clientid);
190 	if (WARN_ON(!client))
191 		return;
192 	mutex_unlock(&client->ioctl_mutex);
193 	/* The doubly unrefs below are intentional; the first one releases the
194 	 * leftover from snd_seq_client_ioctl_lock() above, and the second one
195 	 * is for releasing snd_seq_client_use_ptr() in this function
196 	 */
197 	snd_seq_client_unlock(client);
198 	snd_seq_client_unlock(client);
199 }
200 EXPORT_SYMBOL_GPL(snd_seq_client_ioctl_unlock);
201 
202 static void usage_alloc(struct snd_seq_usage *res, int num)
203 {
204 	res->cur += num;
205 	if (res->cur > res->peak)
206 		res->peak = res->cur;
207 }
208 
209 static void usage_free(struct snd_seq_usage *res, int num)
210 {
211 	res->cur -= num;
212 }
213 
214 /* initialise data structures */
215 int __init client_init_data(void)
216 {
217 	/* zap out the client table */
218 	memset(&clienttablock, 0, sizeof(clienttablock));
219 	memset(&clienttab, 0, sizeof(clienttab));
220 	return 0;
221 }
222 
223 
224 static struct snd_seq_client *seq_create_client1(int client_index, int poolsize)
225 {
226 	int c;
227 	struct snd_seq_client *client;
228 
229 	/* init client data */
230 	client = kzalloc(sizeof(*client), GFP_KERNEL);
231 	if (client == NULL)
232 		return NULL;
233 	client->pool = snd_seq_pool_new(poolsize);
234 	if (client->pool == NULL) {
235 		kfree(client);
236 		return NULL;
237 	}
238 	client->type = NO_CLIENT;
239 	snd_use_lock_init(&client->use_lock);
240 	rwlock_init(&client->ports_lock);
241 	mutex_init(&client->ports_mutex);
242 	INIT_LIST_HEAD(&client->ports_list_head);
243 	mutex_init(&client->ioctl_mutex);
244 
245 	/* find free slot in the client table */
246 	spin_lock_irq(&clients_lock);
247 	if (client_index < 0) {
248 		for (c = SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN;
249 		     c < SNDRV_SEQ_MAX_CLIENTS;
250 		     c++) {
251 			if (clienttab[c] || clienttablock[c])
252 				continue;
253 			clienttab[client->number = c] = client;
254 			spin_unlock_irq(&clients_lock);
255 			return client;
256 		}
257 	} else {
258 		if (clienttab[client_index] == NULL && !clienttablock[client_index]) {
259 			clienttab[client->number = client_index] = client;
260 			spin_unlock_irq(&clients_lock);
261 			return client;
262 		}
263 	}
264 	spin_unlock_irq(&clients_lock);
265 	snd_seq_pool_delete(&client->pool);
266 	kfree(client);
267 	return NULL;	/* no free slot found or busy, return failure code */
268 }
269 
270 
271 static int seq_free_client1(struct snd_seq_client *client)
272 {
273 	if (!client)
274 		return 0;
275 	spin_lock_irq(&clients_lock);
276 	clienttablock[client->number] = 1;
277 	clienttab[client->number] = NULL;
278 	spin_unlock_irq(&clients_lock);
279 	snd_seq_delete_all_ports(client);
280 	snd_seq_queue_client_leave(client->number);
281 	snd_use_lock_sync(&client->use_lock);
282 	snd_seq_queue_client_termination(client->number);
283 	if (client->pool)
284 		snd_seq_pool_delete(&client->pool);
285 	spin_lock_irq(&clients_lock);
286 	clienttablock[client->number] = 0;
287 	spin_unlock_irq(&clients_lock);
288 	return 0;
289 }
290 
291 
292 static void seq_free_client(struct snd_seq_client * client)
293 {
294 	mutex_lock(&register_mutex);
295 	switch (client->type) {
296 	case NO_CLIENT:
297 		pr_warn("ALSA: seq: Trying to free unused client %d\n",
298 			client->number);
299 		break;
300 	case USER_CLIENT:
301 	case KERNEL_CLIENT:
302 		seq_free_client1(client);
303 		usage_free(&client_usage, 1);
304 		break;
305 
306 	default:
307 		pr_err("ALSA: seq: Trying to free client %d with undefined type = %d\n",
308 			   client->number, client->type);
309 	}
310 	mutex_unlock(&register_mutex);
311 
312 	snd_seq_system_client_ev_client_exit(client->number);
313 }
314 
315 
316 
317 /* -------------------------------------------------------- */
318 
319 /* create a user client */
320 static int snd_seq_open(struct inode *inode, struct file *file)
321 {
322 	int c, mode;			/* client id */
323 	struct snd_seq_client *client;
324 	struct snd_seq_user_client *user;
325 	int err;
326 
327 	err = stream_open(inode, file);
328 	if (err < 0)
329 		return err;
330 
331 	mutex_lock(&register_mutex);
332 	client = seq_create_client1(-1, SNDRV_SEQ_DEFAULT_EVENTS);
333 	if (!client) {
334 		mutex_unlock(&register_mutex);
335 		return -ENOMEM;	/* failure code */
336 	}
337 
338 	mode = snd_seq_file_flags(file);
339 	if (mode & SNDRV_SEQ_LFLG_INPUT)
340 		client->accept_input = 1;
341 	if (mode & SNDRV_SEQ_LFLG_OUTPUT)
342 		client->accept_output = 1;
343 
344 	user = &client->data.user;
345 	user->fifo = NULL;
346 	user->fifo_pool_size = 0;
347 
348 	if (mode & SNDRV_SEQ_LFLG_INPUT) {
349 		user->fifo_pool_size = SNDRV_SEQ_DEFAULT_CLIENT_EVENTS;
350 		user->fifo = snd_seq_fifo_new(user->fifo_pool_size);
351 		if (user->fifo == NULL) {
352 			seq_free_client1(client);
353 			kfree(client);
354 			mutex_unlock(&register_mutex);
355 			return -ENOMEM;
356 		}
357 	}
358 
359 	usage_alloc(&client_usage, 1);
360 	client->type = USER_CLIENT;
361 	mutex_unlock(&register_mutex);
362 
363 	c = client->number;
364 	file->private_data = client;
365 
366 	/* fill client data */
367 	user->file = file;
368 	sprintf(client->name, "Client-%d", c);
369 	client->data.user.owner = get_pid(task_pid(current));
370 
371 	/* make others aware this new client */
372 	snd_seq_system_client_ev_client_start(c);
373 
374 	return 0;
375 }
376 
377 /* delete a user client */
378 static int snd_seq_release(struct inode *inode, struct file *file)
379 {
380 	struct snd_seq_client *client = file->private_data;
381 
382 	if (client) {
383 		seq_free_client(client);
384 		if (client->data.user.fifo)
385 			snd_seq_fifo_delete(&client->data.user.fifo);
386 		put_pid(client->data.user.owner);
387 		kfree(client);
388 	}
389 
390 	return 0;
391 }
392 
393 
394 /* handle client read() */
395 /* possible error values:
396  *	-ENXIO	invalid client or file open mode
397  *	-ENOSPC	FIFO overflow (the flag is cleared after this error report)
398  *	-EINVAL	no enough user-space buffer to write the whole event
399  *	-EFAULT	seg. fault during copy to user space
400  */
401 static ssize_t snd_seq_read(struct file *file, char __user *buf, size_t count,
402 			    loff_t *offset)
403 {
404 	struct snd_seq_client *client = file->private_data;
405 	struct snd_seq_fifo *fifo;
406 	int err;
407 	long result = 0;
408 	struct snd_seq_event_cell *cell;
409 
410 	if (!(snd_seq_file_flags(file) & SNDRV_SEQ_LFLG_INPUT))
411 		return -ENXIO;
412 
413 	if (!access_ok(buf, count))
414 		return -EFAULT;
415 
416 	/* check client structures are in place */
417 	if (snd_BUG_ON(!client))
418 		return -ENXIO;
419 
420 	if (!client->accept_input || (fifo = client->data.user.fifo) == NULL)
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 		if ((err = snd_seq_fifo_cell_out(fifo, &cell, nonblock)) < 0) {
440 			break;
441 		}
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);
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 	if ((err = snd_seq_enqueue_event(cell, atomic, hop)) < 0) {
975 		snd_seq_cell_free(cell);
976 		return err;
977 	}
978 
979 	return 0;
980 }
981 
982 
983 /*
984  * check validity of event type and data length.
985  * return non-zero if invalid.
986  */
987 static int check_event_type_and_length(struct snd_seq_event *ev)
988 {
989 	switch (snd_seq_ev_length_type(ev)) {
990 	case SNDRV_SEQ_EVENT_LENGTH_FIXED:
991 		if (snd_seq_ev_is_variable_type(ev))
992 			return -EINVAL;
993 		break;
994 	case SNDRV_SEQ_EVENT_LENGTH_VARIABLE:
995 		if (! snd_seq_ev_is_variable_type(ev) ||
996 		    (ev->data.ext.len & ~SNDRV_SEQ_EXT_MASK) >= SNDRV_SEQ_MAX_EVENT_LEN)
997 			return -EINVAL;
998 		break;
999 	case SNDRV_SEQ_EVENT_LENGTH_VARUSR:
1000 		if (! snd_seq_ev_is_direct(ev))
1001 			return -EINVAL;
1002 		break;
1003 	}
1004 	return 0;
1005 }
1006 
1007 
1008 /* handle write() */
1009 /* possible error values:
1010  *	-ENXIO	invalid client or file open mode
1011  *	-ENOMEM	malloc failed
1012  *	-EFAULT	seg. fault during copy from user space
1013  *	-EINVAL	invalid event
1014  *	-EAGAIN	no space in output pool
1015  *	-EINTR	interrupts while sleep
1016  *	-EMLINK	too many hops
1017  *	others	depends on return value from driver callback
1018  */
1019 static ssize_t snd_seq_write(struct file *file, const char __user *buf,
1020 			     size_t count, loff_t *offset)
1021 {
1022 	struct snd_seq_client *client = file->private_data;
1023 	int written = 0, len;
1024 	int err;
1025 	struct snd_seq_event event;
1026 
1027 	if (!(snd_seq_file_flags(file) & SNDRV_SEQ_LFLG_OUTPUT))
1028 		return -ENXIO;
1029 
1030 	/* check client structures are in place */
1031 	if (snd_BUG_ON(!client))
1032 		return -ENXIO;
1033 
1034 	if (!client->accept_output || client->pool == NULL)
1035 		return -ENXIO;
1036 
1037 	/* allocate the pool now if the pool is not allocated yet */
1038 	mutex_lock(&client->ioctl_mutex);
1039 	if (client->pool->size > 0 && !snd_seq_write_pool_allocated(client)) {
1040 		err = snd_seq_pool_init(client->pool);
1041 		if (err < 0)
1042 			goto out;
1043 	}
1044 
1045 	/* only process whole events */
1046 	err = -EINVAL;
1047 	while (count >= sizeof(struct snd_seq_event)) {
1048 		/* Read in the event header from the user */
1049 		len = sizeof(event);
1050 		if (copy_from_user(&event, buf, len)) {
1051 			err = -EFAULT;
1052 			break;
1053 		}
1054 		event.source.client = client->number;	/* fill in client number */
1055 		/* Check for extension data length */
1056 		if (check_event_type_and_length(&event)) {
1057 			err = -EINVAL;
1058 			break;
1059 		}
1060 
1061 		/* check for special events */
1062 		if (event.type == SNDRV_SEQ_EVENT_NONE)
1063 			goto __skip_event;
1064 		else if (snd_seq_ev_is_reserved(&event)) {
1065 			err = -EINVAL;
1066 			break;
1067 		}
1068 
1069 		if (snd_seq_ev_is_variable(&event)) {
1070 			int extlen = event.data.ext.len & ~SNDRV_SEQ_EXT_MASK;
1071 			if ((size_t)(extlen + len) > count) {
1072 				/* back out, will get an error this time or next */
1073 				err = -EINVAL;
1074 				break;
1075 			}
1076 			/* set user space pointer */
1077 			event.data.ext.len = extlen | SNDRV_SEQ_EXT_USRPTR;
1078 			event.data.ext.ptr = (char __force *)buf
1079 						+ sizeof(struct snd_seq_event);
1080 			len += extlen; /* increment data length */
1081 		} else {
1082 #ifdef CONFIG_COMPAT
1083 			if (client->convert32 && snd_seq_ev_is_varusr(&event)) {
1084 				void *ptr = (void __force *)compat_ptr(event.data.raw32.d[1]);
1085 				event.data.ext.ptr = ptr;
1086 			}
1087 #endif
1088 		}
1089 
1090 		/* ok, enqueue it */
1091 		err = snd_seq_client_enqueue_event(client, &event, file,
1092 						   !(file->f_flags & O_NONBLOCK),
1093 						   0, 0, &client->ioctl_mutex);
1094 		if (err < 0)
1095 			break;
1096 
1097 	__skip_event:
1098 		/* Update pointers and counts */
1099 		count -= len;
1100 		buf += len;
1101 		written += len;
1102 	}
1103 
1104  out:
1105 	mutex_unlock(&client->ioctl_mutex);
1106 	return written ? written : err;
1107 }
1108 
1109 
1110 /*
1111  * handle polling
1112  */
1113 static __poll_t snd_seq_poll(struct file *file, poll_table * wait)
1114 {
1115 	struct snd_seq_client *client = file->private_data;
1116 	__poll_t mask = 0;
1117 
1118 	/* check client structures are in place */
1119 	if (snd_BUG_ON(!client))
1120 		return EPOLLERR;
1121 
1122 	if ((snd_seq_file_flags(file) & SNDRV_SEQ_LFLG_INPUT) &&
1123 	    client->data.user.fifo) {
1124 
1125 		/* check if data is available in the outqueue */
1126 		if (snd_seq_fifo_poll_wait(client->data.user.fifo, file, wait))
1127 			mask |= EPOLLIN | EPOLLRDNORM;
1128 	}
1129 
1130 	if (snd_seq_file_flags(file) & SNDRV_SEQ_LFLG_OUTPUT) {
1131 
1132 		/* check if data is available in the pool */
1133 		if (!snd_seq_write_pool_allocated(client) ||
1134 		    snd_seq_pool_poll_wait(client->pool, file, wait))
1135 			mask |= EPOLLOUT | EPOLLWRNORM;
1136 	}
1137 
1138 	return mask;
1139 }
1140 
1141 
1142 /*-----------------------------------------------------*/
1143 
1144 static int snd_seq_ioctl_pversion(struct snd_seq_client *client, void *arg)
1145 {
1146 	int *pversion = arg;
1147 
1148 	*pversion = SNDRV_SEQ_VERSION;
1149 	return 0;
1150 }
1151 
1152 static int snd_seq_ioctl_client_id(struct snd_seq_client *client, void *arg)
1153 {
1154 	int *client_id = arg;
1155 
1156 	*client_id = client->number;
1157 	return 0;
1158 }
1159 
1160 /* SYSTEM_INFO ioctl() */
1161 static int snd_seq_ioctl_system_info(struct snd_seq_client *client, void *arg)
1162 {
1163 	struct snd_seq_system_info *info = arg;
1164 
1165 	memset(info, 0, sizeof(*info));
1166 	/* fill the info fields */
1167 	info->queues = SNDRV_SEQ_MAX_QUEUES;
1168 	info->clients = SNDRV_SEQ_MAX_CLIENTS;
1169 	info->ports = SNDRV_SEQ_MAX_PORTS;
1170 	info->channels = 256;	/* fixed limit */
1171 	info->cur_clients = client_usage.cur;
1172 	info->cur_queues = snd_seq_queue_get_cur_queues();
1173 
1174 	return 0;
1175 }
1176 
1177 
1178 /* RUNNING_MODE ioctl() */
1179 static int snd_seq_ioctl_running_mode(struct snd_seq_client *client, void  *arg)
1180 {
1181 	struct snd_seq_running_info *info = arg;
1182 	struct snd_seq_client *cptr;
1183 	int err = 0;
1184 
1185 	/* requested client number */
1186 	cptr = snd_seq_client_use_ptr(info->client);
1187 	if (cptr == NULL)
1188 		return -ENOENT;		/* don't change !!! */
1189 
1190 #ifdef SNDRV_BIG_ENDIAN
1191 	if (!info->big_endian) {
1192 		err = -EINVAL;
1193 		goto __err;
1194 	}
1195 #else
1196 	if (info->big_endian) {
1197 		err = -EINVAL;
1198 		goto __err;
1199 	}
1200 
1201 #endif
1202 	if (info->cpu_mode > sizeof(long)) {
1203 		err = -EINVAL;
1204 		goto __err;
1205 	}
1206 	cptr->convert32 = (info->cpu_mode < sizeof(long));
1207  __err:
1208 	snd_seq_client_unlock(cptr);
1209 	return err;
1210 }
1211 
1212 /* CLIENT_INFO ioctl() */
1213 static void get_client_info(struct snd_seq_client *cptr,
1214 			    struct snd_seq_client_info *info)
1215 {
1216 	info->client = cptr->number;
1217 
1218 	/* fill the info fields */
1219 	info->type = cptr->type;
1220 	strcpy(info->name, cptr->name);
1221 	info->filter = cptr->filter;
1222 	info->event_lost = cptr->event_lost;
1223 	memcpy(info->event_filter, cptr->event_filter, 32);
1224 	info->num_ports = cptr->num_ports;
1225 
1226 	if (cptr->type == USER_CLIENT)
1227 		info->pid = pid_vnr(cptr->data.user.owner);
1228 	else
1229 		info->pid = -1;
1230 
1231 	if (cptr->type == KERNEL_CLIENT)
1232 		info->card = cptr->data.kernel.card ? cptr->data.kernel.card->number : -1;
1233 	else
1234 		info->card = -1;
1235 
1236 	memset(info->reserved, 0, sizeof(info->reserved));
1237 }
1238 
1239 static int snd_seq_ioctl_get_client_info(struct snd_seq_client *client,
1240 					 void *arg)
1241 {
1242 	struct snd_seq_client_info *client_info = arg;
1243 	struct snd_seq_client *cptr;
1244 
1245 	/* requested client number */
1246 	cptr = snd_seq_client_use_ptr(client_info->client);
1247 	if (cptr == NULL)
1248 		return -ENOENT;		/* don't change !!! */
1249 
1250 	get_client_info(cptr, client_info);
1251 	snd_seq_client_unlock(cptr);
1252 
1253 	return 0;
1254 }
1255 
1256 
1257 /* CLIENT_INFO ioctl() */
1258 static int snd_seq_ioctl_set_client_info(struct snd_seq_client *client,
1259 					 void *arg)
1260 {
1261 	struct snd_seq_client_info *client_info = arg;
1262 
1263 	/* it is not allowed to set the info fields for an another client */
1264 	if (client->number != client_info->client)
1265 		return -EPERM;
1266 	/* also client type must be set now */
1267 	if (client->type != client_info->type)
1268 		return -EINVAL;
1269 
1270 	/* fill the info fields */
1271 	if (client_info->name[0])
1272 		strscpy(client->name, client_info->name, sizeof(client->name));
1273 
1274 	client->filter = client_info->filter;
1275 	client->event_lost = client_info->event_lost;
1276 	memcpy(client->event_filter, client_info->event_filter, 32);
1277 
1278 	return 0;
1279 }
1280 
1281 
1282 /*
1283  * CREATE PORT ioctl()
1284  */
1285 static int snd_seq_ioctl_create_port(struct snd_seq_client *client, void *arg)
1286 {
1287 	struct snd_seq_port_info *info = arg;
1288 	struct snd_seq_client_port *port;
1289 	struct snd_seq_port_callback *callback;
1290 	int port_idx;
1291 
1292 	/* it is not allowed to create the port for an another client */
1293 	if (info->addr.client != client->number)
1294 		return -EPERM;
1295 
1296 	port = snd_seq_create_port(client, (info->flags & SNDRV_SEQ_PORT_FLG_GIVEN_PORT) ? info->addr.port : -1);
1297 	if (port == NULL)
1298 		return -ENOMEM;
1299 
1300 	if (client->type == USER_CLIENT && info->kernel) {
1301 		port_idx = port->addr.port;
1302 		snd_seq_port_unlock(port);
1303 		snd_seq_delete_port(client, port_idx);
1304 		return -EINVAL;
1305 	}
1306 	if (client->type == KERNEL_CLIENT) {
1307 		if ((callback = info->kernel) != NULL) {
1308 			if (callback->owner)
1309 				port->owner = callback->owner;
1310 			port->private_data = callback->private_data;
1311 			port->private_free = callback->private_free;
1312 			port->event_input = callback->event_input;
1313 			port->c_src.open = callback->subscribe;
1314 			port->c_src.close = callback->unsubscribe;
1315 			port->c_dest.open = callback->use;
1316 			port->c_dest.close = callback->unuse;
1317 		}
1318 	}
1319 
1320 	info->addr = port->addr;
1321 
1322 	snd_seq_set_port_info(port, info);
1323 	snd_seq_system_client_ev_port_start(port->addr.client, port->addr.port);
1324 	snd_seq_port_unlock(port);
1325 
1326 	return 0;
1327 }
1328 
1329 /*
1330  * DELETE PORT ioctl()
1331  */
1332 static int snd_seq_ioctl_delete_port(struct snd_seq_client *client, void *arg)
1333 {
1334 	struct snd_seq_port_info *info = arg;
1335 	int err;
1336 
1337 	/* it is not allowed to remove the port for an another client */
1338 	if (info->addr.client != client->number)
1339 		return -EPERM;
1340 
1341 	err = snd_seq_delete_port(client, info->addr.port);
1342 	if (err >= 0)
1343 		snd_seq_system_client_ev_port_exit(client->number, info->addr.port);
1344 	return err;
1345 }
1346 
1347 
1348 /*
1349  * GET_PORT_INFO ioctl() (on any client)
1350  */
1351 static int snd_seq_ioctl_get_port_info(struct snd_seq_client *client, void *arg)
1352 {
1353 	struct snd_seq_port_info *info = arg;
1354 	struct snd_seq_client *cptr;
1355 	struct snd_seq_client_port *port;
1356 
1357 	cptr = snd_seq_client_use_ptr(info->addr.client);
1358 	if (cptr == NULL)
1359 		return -ENXIO;
1360 
1361 	port = snd_seq_port_use_ptr(cptr, info->addr.port);
1362 	if (port == NULL) {
1363 		snd_seq_client_unlock(cptr);
1364 		return -ENOENT;			/* don't change */
1365 	}
1366 
1367 	/* get port info */
1368 	snd_seq_get_port_info(port, info);
1369 	snd_seq_port_unlock(port);
1370 	snd_seq_client_unlock(cptr);
1371 
1372 	return 0;
1373 }
1374 
1375 
1376 /*
1377  * SET_PORT_INFO ioctl() (only ports on this/own client)
1378  */
1379 static int snd_seq_ioctl_set_port_info(struct snd_seq_client *client, void *arg)
1380 {
1381 	struct snd_seq_port_info *info = arg;
1382 	struct snd_seq_client_port *port;
1383 
1384 	if (info->addr.client != client->number) /* only set our own ports ! */
1385 		return -EPERM;
1386 	port = snd_seq_port_use_ptr(client, info->addr.port);
1387 	if (port) {
1388 		snd_seq_set_port_info(port, info);
1389 		snd_seq_port_unlock(port);
1390 	}
1391 	return 0;
1392 }
1393 
1394 
1395 /*
1396  * port subscription (connection)
1397  */
1398 #define PERM_RD		(SNDRV_SEQ_PORT_CAP_READ|SNDRV_SEQ_PORT_CAP_SUBS_READ)
1399 #define PERM_WR		(SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_SUBS_WRITE)
1400 
1401 static int check_subscription_permission(struct snd_seq_client *client,
1402 					 struct snd_seq_client_port *sport,
1403 					 struct snd_seq_client_port *dport,
1404 					 struct snd_seq_port_subscribe *subs)
1405 {
1406 	if (client->number != subs->sender.client &&
1407 	    client->number != subs->dest.client) {
1408 		/* connection by third client - check export permission */
1409 		if (check_port_perm(sport, SNDRV_SEQ_PORT_CAP_NO_EXPORT))
1410 			return -EPERM;
1411 		if (check_port_perm(dport, SNDRV_SEQ_PORT_CAP_NO_EXPORT))
1412 			return -EPERM;
1413 	}
1414 
1415 	/* check read permission */
1416 	/* if sender or receiver is the subscribing client itself,
1417 	 * no permission check is necessary
1418 	 */
1419 	if (client->number != subs->sender.client) {
1420 		if (! check_port_perm(sport, PERM_RD))
1421 			return -EPERM;
1422 	}
1423 	/* check write permission */
1424 	if (client->number != subs->dest.client) {
1425 		if (! check_port_perm(dport, PERM_WR))
1426 			return -EPERM;
1427 	}
1428 	return 0;
1429 }
1430 
1431 /*
1432  * send an subscription notify event to user client:
1433  * client must be user client.
1434  */
1435 int snd_seq_client_notify_subscription(int client, int port,
1436 				       struct snd_seq_port_subscribe *info,
1437 				       int evtype)
1438 {
1439 	struct snd_seq_event event;
1440 
1441 	memset(&event, 0, sizeof(event));
1442 	event.type = evtype;
1443 	event.data.connect.dest = info->dest;
1444 	event.data.connect.sender = info->sender;
1445 
1446 	return snd_seq_system_notify(client, port, &event);  /* non-atomic */
1447 }
1448 
1449 
1450 /*
1451  * add to port's subscription list IOCTL interface
1452  */
1453 static int snd_seq_ioctl_subscribe_port(struct snd_seq_client *client,
1454 					void *arg)
1455 {
1456 	struct snd_seq_port_subscribe *subs = arg;
1457 	int result = -EINVAL;
1458 	struct snd_seq_client *receiver = NULL, *sender = NULL;
1459 	struct snd_seq_client_port *sport = NULL, *dport = NULL;
1460 
1461 	if ((receiver = snd_seq_client_use_ptr(subs->dest.client)) == NULL)
1462 		goto __end;
1463 	if ((sender = snd_seq_client_use_ptr(subs->sender.client)) == NULL)
1464 		goto __end;
1465 	if ((sport = snd_seq_port_use_ptr(sender, subs->sender.port)) == NULL)
1466 		goto __end;
1467 	if ((dport = snd_seq_port_use_ptr(receiver, subs->dest.port)) == NULL)
1468 		goto __end;
1469 
1470 	result = check_subscription_permission(client, sport, dport, subs);
1471 	if (result < 0)
1472 		goto __end;
1473 
1474 	/* connect them */
1475 	result = snd_seq_port_connect(client, sender, sport, receiver, dport, subs);
1476 	if (! result) /* broadcast announce */
1477 		snd_seq_client_notify_subscription(SNDRV_SEQ_ADDRESS_SUBSCRIBERS, 0,
1478 						   subs, SNDRV_SEQ_EVENT_PORT_SUBSCRIBED);
1479       __end:
1480       	if (sport)
1481 		snd_seq_port_unlock(sport);
1482 	if (dport)
1483 		snd_seq_port_unlock(dport);
1484 	if (sender)
1485 		snd_seq_client_unlock(sender);
1486 	if (receiver)
1487 		snd_seq_client_unlock(receiver);
1488 	return result;
1489 }
1490 
1491 
1492 /*
1493  * remove from port's subscription list
1494  */
1495 static int snd_seq_ioctl_unsubscribe_port(struct snd_seq_client *client,
1496 					  void *arg)
1497 {
1498 	struct snd_seq_port_subscribe *subs = arg;
1499 	int result = -ENXIO;
1500 	struct snd_seq_client *receiver = NULL, *sender = NULL;
1501 	struct snd_seq_client_port *sport = NULL, *dport = NULL;
1502 
1503 	if ((receiver = snd_seq_client_use_ptr(subs->dest.client)) == NULL)
1504 		goto __end;
1505 	if ((sender = snd_seq_client_use_ptr(subs->sender.client)) == NULL)
1506 		goto __end;
1507 	if ((sport = snd_seq_port_use_ptr(sender, subs->sender.port)) == NULL)
1508 		goto __end;
1509 	if ((dport = snd_seq_port_use_ptr(receiver, subs->dest.port)) == NULL)
1510 		goto __end;
1511 
1512 	result = check_subscription_permission(client, sport, dport, subs);
1513 	if (result < 0)
1514 		goto __end;
1515 
1516 	result = snd_seq_port_disconnect(client, sender, sport, receiver, dport, subs);
1517 	if (! result) /* broadcast announce */
1518 		snd_seq_client_notify_subscription(SNDRV_SEQ_ADDRESS_SUBSCRIBERS, 0,
1519 						   subs, SNDRV_SEQ_EVENT_PORT_UNSUBSCRIBED);
1520       __end:
1521       	if (sport)
1522 		snd_seq_port_unlock(sport);
1523 	if (dport)
1524 		snd_seq_port_unlock(dport);
1525 	if (sender)
1526 		snd_seq_client_unlock(sender);
1527 	if (receiver)
1528 		snd_seq_client_unlock(receiver);
1529 	return result;
1530 }
1531 
1532 
1533 /* CREATE_QUEUE ioctl() */
1534 static int snd_seq_ioctl_create_queue(struct snd_seq_client *client, void *arg)
1535 {
1536 	struct snd_seq_queue_info *info = arg;
1537 	struct snd_seq_queue *q;
1538 
1539 	q = snd_seq_queue_alloc(client->number, info->locked, info->flags);
1540 	if (IS_ERR(q))
1541 		return PTR_ERR(q);
1542 
1543 	info->queue = q->queue;
1544 	info->locked = q->locked;
1545 	info->owner = q->owner;
1546 
1547 	/* set queue name */
1548 	if (!info->name[0])
1549 		snprintf(info->name, sizeof(info->name), "Queue-%d", q->queue);
1550 	strscpy(q->name, info->name, sizeof(q->name));
1551 	snd_use_lock_free(&q->use_lock);
1552 
1553 	return 0;
1554 }
1555 
1556 /* DELETE_QUEUE ioctl() */
1557 static int snd_seq_ioctl_delete_queue(struct snd_seq_client *client, void *arg)
1558 {
1559 	struct snd_seq_queue_info *info = arg;
1560 
1561 	return snd_seq_queue_delete(client->number, info->queue);
1562 }
1563 
1564 /* GET_QUEUE_INFO ioctl() */
1565 static int snd_seq_ioctl_get_queue_info(struct snd_seq_client *client,
1566 					void *arg)
1567 {
1568 	struct snd_seq_queue_info *info = arg;
1569 	struct snd_seq_queue *q;
1570 
1571 	q = queueptr(info->queue);
1572 	if (q == NULL)
1573 		return -EINVAL;
1574 
1575 	memset(info, 0, sizeof(*info));
1576 	info->queue = q->queue;
1577 	info->owner = q->owner;
1578 	info->locked = q->locked;
1579 	strlcpy(info->name, q->name, sizeof(info->name));
1580 	queuefree(q);
1581 
1582 	return 0;
1583 }
1584 
1585 /* SET_QUEUE_INFO ioctl() */
1586 static int snd_seq_ioctl_set_queue_info(struct snd_seq_client *client,
1587 					void *arg)
1588 {
1589 	struct snd_seq_queue_info *info = arg;
1590 	struct snd_seq_queue *q;
1591 
1592 	if (info->owner != client->number)
1593 		return -EINVAL;
1594 
1595 	/* change owner/locked permission */
1596 	if (snd_seq_queue_check_access(info->queue, client->number)) {
1597 		if (snd_seq_queue_set_owner(info->queue, client->number, info->locked) < 0)
1598 			return -EPERM;
1599 		if (info->locked)
1600 			snd_seq_queue_use(info->queue, client->number, 1);
1601 	} else {
1602 		return -EPERM;
1603 	}
1604 
1605 	q = queueptr(info->queue);
1606 	if (! q)
1607 		return -EINVAL;
1608 	if (q->owner != client->number) {
1609 		queuefree(q);
1610 		return -EPERM;
1611 	}
1612 	strscpy(q->name, info->name, sizeof(q->name));
1613 	queuefree(q);
1614 
1615 	return 0;
1616 }
1617 
1618 /* GET_NAMED_QUEUE ioctl() */
1619 static int snd_seq_ioctl_get_named_queue(struct snd_seq_client *client,
1620 					 void *arg)
1621 {
1622 	struct snd_seq_queue_info *info = arg;
1623 	struct snd_seq_queue *q;
1624 
1625 	q = snd_seq_queue_find_name(info->name);
1626 	if (q == NULL)
1627 		return -EINVAL;
1628 	info->queue = q->queue;
1629 	info->owner = q->owner;
1630 	info->locked = q->locked;
1631 	queuefree(q);
1632 
1633 	return 0;
1634 }
1635 
1636 /* GET_QUEUE_STATUS ioctl() */
1637 static int snd_seq_ioctl_get_queue_status(struct snd_seq_client *client,
1638 					  void *arg)
1639 {
1640 	struct snd_seq_queue_status *status = arg;
1641 	struct snd_seq_queue *queue;
1642 	struct snd_seq_timer *tmr;
1643 
1644 	queue = queueptr(status->queue);
1645 	if (queue == NULL)
1646 		return -EINVAL;
1647 	memset(status, 0, sizeof(*status));
1648 	status->queue = queue->queue;
1649 
1650 	tmr = queue->timer;
1651 	status->events = queue->tickq->cells + queue->timeq->cells;
1652 
1653 	status->time = snd_seq_timer_get_cur_time(tmr);
1654 	status->tick = snd_seq_timer_get_cur_tick(tmr);
1655 
1656 	status->running = tmr->running;
1657 
1658 	status->flags = queue->flags;
1659 	queuefree(queue);
1660 
1661 	return 0;
1662 }
1663 
1664 
1665 /* GET_QUEUE_TEMPO ioctl() */
1666 static int snd_seq_ioctl_get_queue_tempo(struct snd_seq_client *client,
1667 					 void *arg)
1668 {
1669 	struct snd_seq_queue_tempo *tempo = arg;
1670 	struct snd_seq_queue *queue;
1671 	struct snd_seq_timer *tmr;
1672 
1673 	queue = queueptr(tempo->queue);
1674 	if (queue == NULL)
1675 		return -EINVAL;
1676 	memset(tempo, 0, sizeof(*tempo));
1677 	tempo->queue = queue->queue;
1678 
1679 	tmr = queue->timer;
1680 
1681 	tempo->tempo = tmr->tempo;
1682 	tempo->ppq = tmr->ppq;
1683 	tempo->skew_value = tmr->skew;
1684 	tempo->skew_base = tmr->skew_base;
1685 	queuefree(queue);
1686 
1687 	return 0;
1688 }
1689 
1690 
1691 /* SET_QUEUE_TEMPO ioctl() */
1692 int snd_seq_set_queue_tempo(int client, struct snd_seq_queue_tempo *tempo)
1693 {
1694 	if (!snd_seq_queue_check_access(tempo->queue, client))
1695 		return -EPERM;
1696 	return snd_seq_queue_timer_set_tempo(tempo->queue, client, tempo);
1697 }
1698 EXPORT_SYMBOL(snd_seq_set_queue_tempo);
1699 
1700 static int snd_seq_ioctl_set_queue_tempo(struct snd_seq_client *client,
1701 					 void *arg)
1702 {
1703 	struct snd_seq_queue_tempo *tempo = arg;
1704 	int result;
1705 
1706 	result = snd_seq_set_queue_tempo(client->number, tempo);
1707 	return result < 0 ? result : 0;
1708 }
1709 
1710 
1711 /* GET_QUEUE_TIMER ioctl() */
1712 static int snd_seq_ioctl_get_queue_timer(struct snd_seq_client *client,
1713 					 void *arg)
1714 {
1715 	struct snd_seq_queue_timer *timer = arg;
1716 	struct snd_seq_queue *queue;
1717 	struct snd_seq_timer *tmr;
1718 
1719 	queue = queueptr(timer->queue);
1720 	if (queue == NULL)
1721 		return -EINVAL;
1722 
1723 	mutex_lock(&queue->timer_mutex);
1724 	tmr = queue->timer;
1725 	memset(timer, 0, sizeof(*timer));
1726 	timer->queue = queue->queue;
1727 
1728 	timer->type = tmr->type;
1729 	if (tmr->type == SNDRV_SEQ_TIMER_ALSA) {
1730 		timer->u.alsa.id = tmr->alsa_id;
1731 		timer->u.alsa.resolution = tmr->preferred_resolution;
1732 	}
1733 	mutex_unlock(&queue->timer_mutex);
1734 	queuefree(queue);
1735 
1736 	return 0;
1737 }
1738 
1739 
1740 /* SET_QUEUE_TIMER ioctl() */
1741 static int snd_seq_ioctl_set_queue_timer(struct snd_seq_client *client,
1742 					 void *arg)
1743 {
1744 	struct snd_seq_queue_timer *timer = arg;
1745 	int result = 0;
1746 
1747 	if (timer->type != SNDRV_SEQ_TIMER_ALSA)
1748 		return -EINVAL;
1749 
1750 	if (snd_seq_queue_check_access(timer->queue, client->number)) {
1751 		struct snd_seq_queue *q;
1752 		struct snd_seq_timer *tmr;
1753 
1754 		q = queueptr(timer->queue);
1755 		if (q == NULL)
1756 			return -ENXIO;
1757 		mutex_lock(&q->timer_mutex);
1758 		tmr = q->timer;
1759 		snd_seq_queue_timer_close(timer->queue);
1760 		tmr->type = timer->type;
1761 		if (tmr->type == SNDRV_SEQ_TIMER_ALSA) {
1762 			tmr->alsa_id = timer->u.alsa.id;
1763 			tmr->preferred_resolution = timer->u.alsa.resolution;
1764 		}
1765 		result = snd_seq_queue_timer_open(timer->queue);
1766 		mutex_unlock(&q->timer_mutex);
1767 		queuefree(q);
1768 	} else {
1769 		return -EPERM;
1770 	}
1771 
1772 	return result;
1773 }
1774 
1775 
1776 /* GET_QUEUE_CLIENT ioctl() */
1777 static int snd_seq_ioctl_get_queue_client(struct snd_seq_client *client,
1778 					  void *arg)
1779 {
1780 	struct snd_seq_queue_client *info = arg;
1781 	int used;
1782 
1783 	used = snd_seq_queue_is_used(info->queue, client->number);
1784 	if (used < 0)
1785 		return -EINVAL;
1786 	info->used = used;
1787 	info->client = client->number;
1788 
1789 	return 0;
1790 }
1791 
1792 
1793 /* SET_QUEUE_CLIENT ioctl() */
1794 static int snd_seq_ioctl_set_queue_client(struct snd_seq_client *client,
1795 					  void *arg)
1796 {
1797 	struct snd_seq_queue_client *info = arg;
1798 	int err;
1799 
1800 	if (info->used >= 0) {
1801 		err = snd_seq_queue_use(info->queue, client->number, info->used);
1802 		if (err < 0)
1803 			return err;
1804 	}
1805 
1806 	return snd_seq_ioctl_get_queue_client(client, arg);
1807 }
1808 
1809 
1810 /* GET_CLIENT_POOL ioctl() */
1811 static int snd_seq_ioctl_get_client_pool(struct snd_seq_client *client,
1812 					 void *arg)
1813 {
1814 	struct snd_seq_client_pool *info = arg;
1815 	struct snd_seq_client *cptr;
1816 
1817 	cptr = snd_seq_client_use_ptr(info->client);
1818 	if (cptr == NULL)
1819 		return -ENOENT;
1820 	memset(info, 0, sizeof(*info));
1821 	info->client = cptr->number;
1822 	info->output_pool = cptr->pool->size;
1823 	info->output_room = cptr->pool->room;
1824 	info->output_free = info->output_pool;
1825 	info->output_free = snd_seq_unused_cells(cptr->pool);
1826 	if (cptr->type == USER_CLIENT) {
1827 		info->input_pool = cptr->data.user.fifo_pool_size;
1828 		info->input_free = info->input_pool;
1829 		if (cptr->data.user.fifo)
1830 			info->input_free = snd_seq_unused_cells(cptr->data.user.fifo->pool);
1831 	} else {
1832 		info->input_pool = 0;
1833 		info->input_free = 0;
1834 	}
1835 	snd_seq_client_unlock(cptr);
1836 
1837 	return 0;
1838 }
1839 
1840 /* SET_CLIENT_POOL ioctl() */
1841 static int snd_seq_ioctl_set_client_pool(struct snd_seq_client *client,
1842 					 void *arg)
1843 {
1844 	struct snd_seq_client_pool *info = arg;
1845 	int rc;
1846 
1847 	if (client->number != info->client)
1848 		return -EINVAL; /* can't change other clients */
1849 
1850 	if (info->output_pool >= 1 && info->output_pool <= SNDRV_SEQ_MAX_EVENTS &&
1851 	    (! snd_seq_write_pool_allocated(client) ||
1852 	     info->output_pool != client->pool->size)) {
1853 		if (snd_seq_write_pool_allocated(client)) {
1854 			/* is the pool in use? */
1855 			if (atomic_read(&client->pool->counter))
1856 				return -EBUSY;
1857 			/* remove all existing cells */
1858 			snd_seq_pool_mark_closing(client->pool);
1859 			snd_seq_pool_done(client->pool);
1860 		}
1861 		client->pool->size = info->output_pool;
1862 		rc = snd_seq_pool_init(client->pool);
1863 		if (rc < 0)
1864 			return rc;
1865 	}
1866 	if (client->type == USER_CLIENT && client->data.user.fifo != NULL &&
1867 	    info->input_pool >= 1 &&
1868 	    info->input_pool <= SNDRV_SEQ_MAX_CLIENT_EVENTS &&
1869 	    info->input_pool != client->data.user.fifo_pool_size) {
1870 		/* change pool size */
1871 		rc = snd_seq_fifo_resize(client->data.user.fifo, info->input_pool);
1872 		if (rc < 0)
1873 			return rc;
1874 		client->data.user.fifo_pool_size = info->input_pool;
1875 	}
1876 	if (info->output_room >= 1 &&
1877 	    info->output_room <= client->pool->size) {
1878 		client->pool->room  = info->output_room;
1879 	}
1880 
1881 	return snd_seq_ioctl_get_client_pool(client, arg);
1882 }
1883 
1884 
1885 /* REMOVE_EVENTS ioctl() */
1886 static int snd_seq_ioctl_remove_events(struct snd_seq_client *client,
1887 				       void *arg)
1888 {
1889 	struct snd_seq_remove_events *info = arg;
1890 
1891 	/*
1892 	 * Input mostly not implemented XXX.
1893 	 */
1894 	if (info->remove_mode & SNDRV_SEQ_REMOVE_INPUT) {
1895 		/*
1896 		 * No restrictions so for a user client we can clear
1897 		 * the whole fifo
1898 		 */
1899 		if (client->type == USER_CLIENT && client->data.user.fifo)
1900 			snd_seq_fifo_clear(client->data.user.fifo);
1901 	}
1902 
1903 	if (info->remove_mode & SNDRV_SEQ_REMOVE_OUTPUT)
1904 		snd_seq_queue_remove_cells(client->number, info);
1905 
1906 	return 0;
1907 }
1908 
1909 
1910 /*
1911  * get subscription info
1912  */
1913 static int snd_seq_ioctl_get_subscription(struct snd_seq_client *client,
1914 					  void *arg)
1915 {
1916 	struct snd_seq_port_subscribe *subs = arg;
1917 	int result;
1918 	struct snd_seq_client *sender = NULL;
1919 	struct snd_seq_client_port *sport = NULL;
1920 
1921 	result = -EINVAL;
1922 	if ((sender = snd_seq_client_use_ptr(subs->sender.client)) == NULL)
1923 		goto __end;
1924 	if ((sport = snd_seq_port_use_ptr(sender, subs->sender.port)) == NULL)
1925 		goto __end;
1926 	result = snd_seq_port_get_subscription(&sport->c_src, &subs->dest,
1927 					       subs);
1928       __end:
1929       	if (sport)
1930 		snd_seq_port_unlock(sport);
1931 	if (sender)
1932 		snd_seq_client_unlock(sender);
1933 
1934 	return result;
1935 }
1936 
1937 
1938 /*
1939  * get subscription info - check only its presence
1940  */
1941 static int snd_seq_ioctl_query_subs(struct snd_seq_client *client, void *arg)
1942 {
1943 	struct snd_seq_query_subs *subs = arg;
1944 	int result = -ENXIO;
1945 	struct snd_seq_client *cptr = NULL;
1946 	struct snd_seq_client_port *port = NULL;
1947 	struct snd_seq_port_subs_info *group;
1948 	struct list_head *p;
1949 	int i;
1950 
1951 	if ((cptr = snd_seq_client_use_ptr(subs->root.client)) == NULL)
1952 		goto __end;
1953 	if ((port = snd_seq_port_use_ptr(cptr, subs->root.port)) == NULL)
1954 		goto __end;
1955 
1956 	switch (subs->type) {
1957 	case SNDRV_SEQ_QUERY_SUBS_READ:
1958 		group = &port->c_src;
1959 		break;
1960 	case SNDRV_SEQ_QUERY_SUBS_WRITE:
1961 		group = &port->c_dest;
1962 		break;
1963 	default:
1964 		goto __end;
1965 	}
1966 
1967 	down_read(&group->list_mutex);
1968 	/* search for the subscriber */
1969 	subs->num_subs = group->count;
1970 	i = 0;
1971 	result = -ENOENT;
1972 	list_for_each(p, &group->list_head) {
1973 		if (i++ == subs->index) {
1974 			/* found! */
1975 			struct snd_seq_subscribers *s;
1976 			if (subs->type == SNDRV_SEQ_QUERY_SUBS_READ) {
1977 				s = list_entry(p, struct snd_seq_subscribers, src_list);
1978 				subs->addr = s->info.dest;
1979 			} else {
1980 				s = list_entry(p, struct snd_seq_subscribers, dest_list);
1981 				subs->addr = s->info.sender;
1982 			}
1983 			subs->flags = s->info.flags;
1984 			subs->queue = s->info.queue;
1985 			result = 0;
1986 			break;
1987 		}
1988 	}
1989 	up_read(&group->list_mutex);
1990 
1991       __end:
1992    	if (port)
1993 		snd_seq_port_unlock(port);
1994 	if (cptr)
1995 		snd_seq_client_unlock(cptr);
1996 
1997 	return result;
1998 }
1999 
2000 
2001 /*
2002  * query next client
2003  */
2004 static int snd_seq_ioctl_query_next_client(struct snd_seq_client *client,
2005 					   void *arg)
2006 {
2007 	struct snd_seq_client_info *info = arg;
2008 	struct snd_seq_client *cptr = NULL;
2009 
2010 	/* search for next client */
2011 	if (info->client < INT_MAX)
2012 		info->client++;
2013 	if (info->client < 0)
2014 		info->client = 0;
2015 	for (; info->client < SNDRV_SEQ_MAX_CLIENTS; info->client++) {
2016 		cptr = snd_seq_client_use_ptr(info->client);
2017 		if (cptr)
2018 			break; /* found */
2019 	}
2020 	if (cptr == NULL)
2021 		return -ENOENT;
2022 
2023 	get_client_info(cptr, info);
2024 	snd_seq_client_unlock(cptr);
2025 
2026 	return 0;
2027 }
2028 
2029 /*
2030  * query next port
2031  */
2032 static int snd_seq_ioctl_query_next_port(struct snd_seq_client *client,
2033 					 void *arg)
2034 {
2035 	struct snd_seq_port_info *info = arg;
2036 	struct snd_seq_client *cptr;
2037 	struct snd_seq_client_port *port = NULL;
2038 
2039 	cptr = snd_seq_client_use_ptr(info->addr.client);
2040 	if (cptr == NULL)
2041 		return -ENXIO;
2042 
2043 	/* search for next port */
2044 	info->addr.port++;
2045 	port = snd_seq_port_query_nearest(cptr, info);
2046 	if (port == NULL) {
2047 		snd_seq_client_unlock(cptr);
2048 		return -ENOENT;
2049 	}
2050 
2051 	/* get port info */
2052 	info->addr = port->addr;
2053 	snd_seq_get_port_info(port, info);
2054 	snd_seq_port_unlock(port);
2055 	snd_seq_client_unlock(cptr);
2056 
2057 	return 0;
2058 }
2059 
2060 /* -------------------------------------------------------- */
2061 
2062 static const struct ioctl_handler {
2063 	unsigned int cmd;
2064 	int (*func)(struct snd_seq_client *client, void *arg);
2065 } ioctl_handlers[] = {
2066 	{ SNDRV_SEQ_IOCTL_PVERSION, snd_seq_ioctl_pversion },
2067 	{ SNDRV_SEQ_IOCTL_CLIENT_ID, snd_seq_ioctl_client_id },
2068 	{ SNDRV_SEQ_IOCTL_SYSTEM_INFO, snd_seq_ioctl_system_info },
2069 	{ SNDRV_SEQ_IOCTL_RUNNING_MODE, snd_seq_ioctl_running_mode },
2070 	{ SNDRV_SEQ_IOCTL_GET_CLIENT_INFO, snd_seq_ioctl_get_client_info },
2071 	{ SNDRV_SEQ_IOCTL_SET_CLIENT_INFO, snd_seq_ioctl_set_client_info },
2072 	{ SNDRV_SEQ_IOCTL_CREATE_PORT, snd_seq_ioctl_create_port },
2073 	{ SNDRV_SEQ_IOCTL_DELETE_PORT, snd_seq_ioctl_delete_port },
2074 	{ SNDRV_SEQ_IOCTL_GET_PORT_INFO, snd_seq_ioctl_get_port_info },
2075 	{ SNDRV_SEQ_IOCTL_SET_PORT_INFO, snd_seq_ioctl_set_port_info },
2076 	{ SNDRV_SEQ_IOCTL_SUBSCRIBE_PORT, snd_seq_ioctl_subscribe_port },
2077 	{ SNDRV_SEQ_IOCTL_UNSUBSCRIBE_PORT, snd_seq_ioctl_unsubscribe_port },
2078 	{ SNDRV_SEQ_IOCTL_CREATE_QUEUE, snd_seq_ioctl_create_queue },
2079 	{ SNDRV_SEQ_IOCTL_DELETE_QUEUE, snd_seq_ioctl_delete_queue },
2080 	{ SNDRV_SEQ_IOCTL_GET_QUEUE_INFO, snd_seq_ioctl_get_queue_info },
2081 	{ SNDRV_SEQ_IOCTL_SET_QUEUE_INFO, snd_seq_ioctl_set_queue_info },
2082 	{ SNDRV_SEQ_IOCTL_GET_NAMED_QUEUE, snd_seq_ioctl_get_named_queue },
2083 	{ SNDRV_SEQ_IOCTL_GET_QUEUE_STATUS, snd_seq_ioctl_get_queue_status },
2084 	{ SNDRV_SEQ_IOCTL_GET_QUEUE_TEMPO, snd_seq_ioctl_get_queue_tempo },
2085 	{ SNDRV_SEQ_IOCTL_SET_QUEUE_TEMPO, snd_seq_ioctl_set_queue_tempo },
2086 	{ SNDRV_SEQ_IOCTL_GET_QUEUE_TIMER, snd_seq_ioctl_get_queue_timer },
2087 	{ SNDRV_SEQ_IOCTL_SET_QUEUE_TIMER, snd_seq_ioctl_set_queue_timer },
2088 	{ SNDRV_SEQ_IOCTL_GET_QUEUE_CLIENT, snd_seq_ioctl_get_queue_client },
2089 	{ SNDRV_SEQ_IOCTL_SET_QUEUE_CLIENT, snd_seq_ioctl_set_queue_client },
2090 	{ SNDRV_SEQ_IOCTL_GET_CLIENT_POOL, snd_seq_ioctl_get_client_pool },
2091 	{ SNDRV_SEQ_IOCTL_SET_CLIENT_POOL, snd_seq_ioctl_set_client_pool },
2092 	{ SNDRV_SEQ_IOCTL_GET_SUBSCRIPTION, snd_seq_ioctl_get_subscription },
2093 	{ SNDRV_SEQ_IOCTL_QUERY_NEXT_CLIENT, snd_seq_ioctl_query_next_client },
2094 	{ SNDRV_SEQ_IOCTL_QUERY_NEXT_PORT, snd_seq_ioctl_query_next_port },
2095 	{ SNDRV_SEQ_IOCTL_REMOVE_EVENTS, snd_seq_ioctl_remove_events },
2096 	{ SNDRV_SEQ_IOCTL_QUERY_SUBS, snd_seq_ioctl_query_subs },
2097 	{ 0, NULL },
2098 };
2099 
2100 static long snd_seq_ioctl(struct file *file, unsigned int cmd,
2101 			  unsigned long arg)
2102 {
2103 	struct snd_seq_client *client = file->private_data;
2104 	/* To use kernel stack for ioctl data. */
2105 	union {
2106 		int pversion;
2107 		int client_id;
2108 		struct snd_seq_system_info	system_info;
2109 		struct snd_seq_running_info	running_info;
2110 		struct snd_seq_client_info	client_info;
2111 		struct snd_seq_port_info	port_info;
2112 		struct snd_seq_port_subscribe	port_subscribe;
2113 		struct snd_seq_queue_info	queue_info;
2114 		struct snd_seq_queue_status	queue_status;
2115 		struct snd_seq_queue_tempo	tempo;
2116 		struct snd_seq_queue_timer	queue_timer;
2117 		struct snd_seq_queue_client	queue_client;
2118 		struct snd_seq_client_pool	client_pool;
2119 		struct snd_seq_remove_events	remove_events;
2120 		struct snd_seq_query_subs	query_subs;
2121 	} buf;
2122 	const struct ioctl_handler *handler;
2123 	unsigned long size;
2124 	int err;
2125 
2126 	if (snd_BUG_ON(!client))
2127 		return -ENXIO;
2128 
2129 	for (handler = ioctl_handlers; handler->cmd > 0; ++handler) {
2130 		if (handler->cmd == cmd)
2131 			break;
2132 	}
2133 	if (handler->cmd == 0)
2134 		return -ENOTTY;
2135 
2136 	memset(&buf, 0, sizeof(buf));
2137 
2138 	/*
2139 	 * All of ioctl commands for ALSA sequencer get an argument of size
2140 	 * within 13 bits. We can safely pick up the size from the command.
2141 	 */
2142 	size = _IOC_SIZE(handler->cmd);
2143 	if (handler->cmd & IOC_IN) {
2144 		if (copy_from_user(&buf, (const void __user *)arg, size))
2145 			return -EFAULT;
2146 	}
2147 
2148 	mutex_lock(&client->ioctl_mutex);
2149 	err = handler->func(client, &buf);
2150 	mutex_unlock(&client->ioctl_mutex);
2151 	if (err >= 0) {
2152 		/* Some commands includes a bug in 'dir' field. */
2153 		if (handler->cmd == SNDRV_SEQ_IOCTL_SET_QUEUE_CLIENT ||
2154 		    handler->cmd == SNDRV_SEQ_IOCTL_SET_CLIENT_POOL ||
2155 		    (handler->cmd & IOC_OUT))
2156 			if (copy_to_user((void __user *)arg, &buf, size))
2157 				return -EFAULT;
2158 	}
2159 
2160 	return err;
2161 }
2162 
2163 #ifdef CONFIG_COMPAT
2164 #include "seq_compat.c"
2165 #else
2166 #define snd_seq_ioctl_compat	NULL
2167 #endif
2168 
2169 /* -------------------------------------------------------- */
2170 
2171 
2172 /* exported to kernel modules */
2173 int snd_seq_create_kernel_client(struct snd_card *card, int client_index,
2174 				 const char *name_fmt, ...)
2175 {
2176 	struct snd_seq_client *client;
2177 	va_list args;
2178 
2179 	if (snd_BUG_ON(in_interrupt()))
2180 		return -EBUSY;
2181 
2182 	if (card && client_index >= SNDRV_SEQ_CLIENTS_PER_CARD)
2183 		return -EINVAL;
2184 	if (card == NULL && client_index >= SNDRV_SEQ_GLOBAL_CLIENTS)
2185 		return -EINVAL;
2186 
2187 	mutex_lock(&register_mutex);
2188 
2189 	if (card) {
2190 		client_index += SNDRV_SEQ_GLOBAL_CLIENTS
2191 			+ card->number * SNDRV_SEQ_CLIENTS_PER_CARD;
2192 		if (client_index >= SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN)
2193 			client_index = -1;
2194 	}
2195 
2196 	/* empty write queue as default */
2197 	client = seq_create_client1(client_index, 0);
2198 	if (client == NULL) {
2199 		mutex_unlock(&register_mutex);
2200 		return -EBUSY;	/* failure code */
2201 	}
2202 	usage_alloc(&client_usage, 1);
2203 
2204 	client->accept_input = 1;
2205 	client->accept_output = 1;
2206 	client->data.kernel.card = card;
2207 
2208 	va_start(args, name_fmt);
2209 	vsnprintf(client->name, sizeof(client->name), name_fmt, args);
2210 	va_end(args);
2211 
2212 	client->type = KERNEL_CLIENT;
2213 	mutex_unlock(&register_mutex);
2214 
2215 	/* make others aware this new client */
2216 	snd_seq_system_client_ev_client_start(client->number);
2217 
2218 	/* return client number to caller */
2219 	return client->number;
2220 }
2221 EXPORT_SYMBOL(snd_seq_create_kernel_client);
2222 
2223 /* exported to kernel modules */
2224 int snd_seq_delete_kernel_client(int client)
2225 {
2226 	struct snd_seq_client *ptr;
2227 
2228 	if (snd_BUG_ON(in_interrupt()))
2229 		return -EBUSY;
2230 
2231 	ptr = clientptr(client);
2232 	if (ptr == NULL)
2233 		return -EINVAL;
2234 
2235 	seq_free_client(ptr);
2236 	kfree(ptr);
2237 	return 0;
2238 }
2239 EXPORT_SYMBOL(snd_seq_delete_kernel_client);
2240 
2241 /*
2242  * exported, called by kernel clients to enqueue events (w/o blocking)
2243  *
2244  * RETURN VALUE: zero if succeed, negative if error
2245  */
2246 int snd_seq_kernel_client_enqueue(int client, struct snd_seq_event *ev,
2247 				  struct file *file, bool blocking)
2248 {
2249 	struct snd_seq_client *cptr;
2250 	int result;
2251 
2252 	if (snd_BUG_ON(!ev))
2253 		return -EINVAL;
2254 
2255 	if (ev->type == SNDRV_SEQ_EVENT_NONE)
2256 		return 0; /* ignore this */
2257 	if (ev->type == SNDRV_SEQ_EVENT_KERNEL_ERROR)
2258 		return -EINVAL; /* quoted events can't be enqueued */
2259 
2260 	/* fill in client number */
2261 	ev->source.client = client;
2262 
2263 	if (check_event_type_and_length(ev))
2264 		return -EINVAL;
2265 
2266 	cptr = snd_seq_client_use_ptr(client);
2267 	if (cptr == NULL)
2268 		return -EINVAL;
2269 
2270 	if (!cptr->accept_output) {
2271 		result = -EPERM;
2272 	} else { /* send it */
2273 		mutex_lock(&cptr->ioctl_mutex);
2274 		result = snd_seq_client_enqueue_event(cptr, ev, file, blocking,
2275 						      false, 0,
2276 						      &cptr->ioctl_mutex);
2277 		mutex_unlock(&cptr->ioctl_mutex);
2278 	}
2279 
2280 	snd_seq_client_unlock(cptr);
2281 	return result;
2282 }
2283 EXPORT_SYMBOL(snd_seq_kernel_client_enqueue);
2284 
2285 /*
2286  * exported, called by kernel clients to dispatch events directly to other
2287  * clients, bypassing the queues.  Event time-stamp will be updated.
2288  *
2289  * RETURN VALUE: negative = delivery failed,
2290  *		 zero, or positive: the number of delivered events
2291  */
2292 int snd_seq_kernel_client_dispatch(int client, struct snd_seq_event * ev,
2293 				   int atomic, int hop)
2294 {
2295 	struct snd_seq_client *cptr;
2296 	int result;
2297 
2298 	if (snd_BUG_ON(!ev))
2299 		return -EINVAL;
2300 
2301 	/* fill in client number */
2302 	ev->queue = SNDRV_SEQ_QUEUE_DIRECT;
2303 	ev->source.client = client;
2304 
2305 	if (check_event_type_and_length(ev))
2306 		return -EINVAL;
2307 
2308 	cptr = snd_seq_client_use_ptr(client);
2309 	if (cptr == NULL)
2310 		return -EINVAL;
2311 
2312 	if (!cptr->accept_output)
2313 		result = -EPERM;
2314 	else
2315 		result = snd_seq_deliver_event(cptr, ev, atomic, hop);
2316 
2317 	snd_seq_client_unlock(cptr);
2318 	return result;
2319 }
2320 EXPORT_SYMBOL(snd_seq_kernel_client_dispatch);
2321 
2322 /**
2323  * snd_seq_kernel_client_ctl - operate a command for a client with data in
2324  *			       kernel space.
2325  * @clientid:	A numerical ID for a client.
2326  * @cmd:	An ioctl(2) command for ALSA sequencer operation.
2327  * @arg:	A pointer to data in kernel space.
2328  *
2329  * Against its name, both kernel/application client can be handled by this
2330  * kernel API. A pointer of 'arg' argument should be in kernel space.
2331  *
2332  * Return: 0 at success. Negative error code at failure.
2333  */
2334 int snd_seq_kernel_client_ctl(int clientid, unsigned int cmd, void *arg)
2335 {
2336 	const struct ioctl_handler *handler;
2337 	struct snd_seq_client *client;
2338 
2339 	client = clientptr(clientid);
2340 	if (client == NULL)
2341 		return -ENXIO;
2342 
2343 	for (handler = ioctl_handlers; handler->cmd > 0; ++handler) {
2344 		if (handler->cmd == cmd)
2345 			return handler->func(client, arg);
2346 	}
2347 
2348 	pr_debug("ALSA: seq unknown ioctl() 0x%x (type='%c', number=0x%02x)\n",
2349 		 cmd, _IOC_TYPE(cmd), _IOC_NR(cmd));
2350 	return -ENOTTY;
2351 }
2352 EXPORT_SYMBOL(snd_seq_kernel_client_ctl);
2353 
2354 /* exported (for OSS emulator) */
2355 int snd_seq_kernel_client_write_poll(int clientid, struct file *file, poll_table *wait)
2356 {
2357 	struct snd_seq_client *client;
2358 
2359 	client = clientptr(clientid);
2360 	if (client == NULL)
2361 		return -ENXIO;
2362 
2363 	if (! snd_seq_write_pool_allocated(client))
2364 		return 1;
2365 	if (snd_seq_pool_poll_wait(client->pool, file, wait))
2366 		return 1;
2367 	return 0;
2368 }
2369 EXPORT_SYMBOL(snd_seq_kernel_client_write_poll);
2370 
2371 /*---------------------------------------------------------------------------*/
2372 
2373 #ifdef CONFIG_SND_PROC_FS
2374 /*
2375  *  /proc interface
2376  */
2377 static void snd_seq_info_dump_subscribers(struct snd_info_buffer *buffer,
2378 					  struct snd_seq_port_subs_info *group,
2379 					  int is_src, char *msg)
2380 {
2381 	struct list_head *p;
2382 	struct snd_seq_subscribers *s;
2383 	int count = 0;
2384 
2385 	down_read(&group->list_mutex);
2386 	if (list_empty(&group->list_head)) {
2387 		up_read(&group->list_mutex);
2388 		return;
2389 	}
2390 	snd_iprintf(buffer, msg);
2391 	list_for_each(p, &group->list_head) {
2392 		if (is_src)
2393 			s = list_entry(p, struct snd_seq_subscribers, src_list);
2394 		else
2395 			s = list_entry(p, struct snd_seq_subscribers, dest_list);
2396 		if (count++)
2397 			snd_iprintf(buffer, ", ");
2398 		snd_iprintf(buffer, "%d:%d",
2399 			    is_src ? s->info.dest.client : s->info.sender.client,
2400 			    is_src ? s->info.dest.port : s->info.sender.port);
2401 		if (s->info.flags & SNDRV_SEQ_PORT_SUBS_TIMESTAMP)
2402 			snd_iprintf(buffer, "[%c:%d]", ((s->info.flags & SNDRV_SEQ_PORT_SUBS_TIME_REAL) ? 'r' : 't'), s->info.queue);
2403 		if (group->exclusive)
2404 			snd_iprintf(buffer, "[ex]");
2405 	}
2406 	up_read(&group->list_mutex);
2407 	snd_iprintf(buffer, "\n");
2408 }
2409 
2410 #define FLAG_PERM_RD(perm) ((perm) & SNDRV_SEQ_PORT_CAP_READ ? ((perm) & SNDRV_SEQ_PORT_CAP_SUBS_READ ? 'R' : 'r') : '-')
2411 #define FLAG_PERM_WR(perm) ((perm) & SNDRV_SEQ_PORT_CAP_WRITE ? ((perm) & SNDRV_SEQ_PORT_CAP_SUBS_WRITE ? 'W' : 'w') : '-')
2412 #define FLAG_PERM_EX(perm) ((perm) & SNDRV_SEQ_PORT_CAP_NO_EXPORT ? '-' : 'e')
2413 
2414 #define FLAG_PERM_DUPLEX(perm) ((perm) & SNDRV_SEQ_PORT_CAP_DUPLEX ? 'X' : '-')
2415 
2416 static void snd_seq_info_dump_ports(struct snd_info_buffer *buffer,
2417 				    struct snd_seq_client *client)
2418 {
2419 	struct snd_seq_client_port *p;
2420 
2421 	mutex_lock(&client->ports_mutex);
2422 	list_for_each_entry(p, &client->ports_list_head, list) {
2423 		snd_iprintf(buffer, "  Port %3d : \"%s\" (%c%c%c%c)\n",
2424 			    p->addr.port, p->name,
2425 			    FLAG_PERM_RD(p->capability),
2426 			    FLAG_PERM_WR(p->capability),
2427 			    FLAG_PERM_EX(p->capability),
2428 			    FLAG_PERM_DUPLEX(p->capability));
2429 		snd_seq_info_dump_subscribers(buffer, &p->c_src, 1, "    Connecting To: ");
2430 		snd_seq_info_dump_subscribers(buffer, &p->c_dest, 0, "    Connected From: ");
2431 	}
2432 	mutex_unlock(&client->ports_mutex);
2433 }
2434 
2435 
2436 /* exported to seq_info.c */
2437 void snd_seq_info_clients_read(struct snd_info_entry *entry,
2438 			       struct snd_info_buffer *buffer)
2439 {
2440 	int c;
2441 	struct snd_seq_client *client;
2442 
2443 	snd_iprintf(buffer, "Client info\n");
2444 	snd_iprintf(buffer, "  cur  clients : %d\n", client_usage.cur);
2445 	snd_iprintf(buffer, "  peak clients : %d\n", client_usage.peak);
2446 	snd_iprintf(buffer, "  max  clients : %d\n", SNDRV_SEQ_MAX_CLIENTS);
2447 	snd_iprintf(buffer, "\n");
2448 
2449 	/* list the client table */
2450 	for (c = 0; c < SNDRV_SEQ_MAX_CLIENTS; c++) {
2451 		client = snd_seq_client_use_ptr(c);
2452 		if (client == NULL)
2453 			continue;
2454 		if (client->type == NO_CLIENT) {
2455 			snd_seq_client_unlock(client);
2456 			continue;
2457 		}
2458 
2459 		snd_iprintf(buffer, "Client %3d : \"%s\" [%s]\n",
2460 			    c, client->name,
2461 			    client->type == USER_CLIENT ? "User" : "Kernel");
2462 		snd_seq_info_dump_ports(buffer, client);
2463 		if (snd_seq_write_pool_allocated(client)) {
2464 			snd_iprintf(buffer, "  Output pool :\n");
2465 			snd_seq_info_pool(buffer, client->pool, "    ");
2466 		}
2467 		if (client->type == USER_CLIENT && client->data.user.fifo &&
2468 		    client->data.user.fifo->pool) {
2469 			snd_iprintf(buffer, "  Input pool :\n");
2470 			snd_seq_info_pool(buffer, client->data.user.fifo->pool, "    ");
2471 		}
2472 		snd_seq_client_unlock(client);
2473 	}
2474 }
2475 #endif /* CONFIG_SND_PROC_FS */
2476 
2477 /*---------------------------------------------------------------------------*/
2478 
2479 
2480 /*
2481  *  REGISTRATION PART
2482  */
2483 
2484 static const struct file_operations snd_seq_f_ops =
2485 {
2486 	.owner =	THIS_MODULE,
2487 	.read =		snd_seq_read,
2488 	.write =	snd_seq_write,
2489 	.open =		snd_seq_open,
2490 	.release =	snd_seq_release,
2491 	.llseek =	no_llseek,
2492 	.poll =		snd_seq_poll,
2493 	.unlocked_ioctl =	snd_seq_ioctl,
2494 	.compat_ioctl =	snd_seq_ioctl_compat,
2495 };
2496 
2497 static struct device seq_dev;
2498 
2499 /*
2500  * register sequencer device
2501  */
2502 int __init snd_sequencer_device_init(void)
2503 {
2504 	int err;
2505 
2506 	snd_device_initialize(&seq_dev, NULL);
2507 	dev_set_name(&seq_dev, "seq");
2508 
2509 	mutex_lock(&register_mutex);
2510 	err = snd_register_device(SNDRV_DEVICE_TYPE_SEQUENCER, NULL, 0,
2511 				  &snd_seq_f_ops, NULL, &seq_dev);
2512 	mutex_unlock(&register_mutex);
2513 	if (err < 0) {
2514 		put_device(&seq_dev);
2515 		return err;
2516 	}
2517 
2518 	return 0;
2519 }
2520 
2521 
2522 
2523 /*
2524  * unregister sequencer device
2525  */
2526 void snd_sequencer_device_done(void)
2527 {
2528 	snd_unregister_device(&seq_dev);
2529 	put_device(&seq_dev);
2530 }
2531