1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * OSS compatible sequencer driver
4  *
5  * synth device handlers
6  *
7  * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
8  */
9 
10 #include "seq_oss_synth.h"
11 #include "seq_oss_midi.h"
12 #include "../seq_lock.h"
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/nospec.h>
17 
18 /*
19  * constants
20  */
21 #define SNDRV_SEQ_OSS_MAX_SYNTH_NAME	30
22 #define MAX_SYSEX_BUFLEN		128
23 
24 
25 /*
26  * definition of synth info records
27  */
28 
29 /* sysex buffer */
30 struct seq_oss_synth_sysex {
31 	int len;
32 	int skip;
33 	unsigned char buf[MAX_SYSEX_BUFLEN];
34 };
35 
36 /* synth info */
37 struct seq_oss_synth {
38 	int seq_device;
39 
40 	/* for synth_info */
41 	int synth_type;
42 	int synth_subtype;
43 	int nr_voices;
44 
45 	char name[SNDRV_SEQ_OSS_MAX_SYNTH_NAME];
46 	struct snd_seq_oss_callback oper;
47 
48 	int opened;
49 
50 	void *private_data;
51 	snd_use_lock_t use_lock;
52 };
53 
54 
55 /*
56  * device table
57  */
58 static int max_synth_devs;
59 static struct seq_oss_synth *synth_devs[SNDRV_SEQ_OSS_MAX_SYNTH_DEVS];
60 static struct seq_oss_synth midi_synth_dev = {
61 	.seq_device = -1,
62 	.synth_type = SYNTH_TYPE_MIDI,
63 	.synth_subtype = 0,
64 	.nr_voices = 16,
65 	.name = "MIDI",
66 };
67 
68 static DEFINE_SPINLOCK(register_lock);
69 
70 /*
71  * prototypes
72  */
73 static struct seq_oss_synth *get_synthdev(struct seq_oss_devinfo *dp, int dev);
74 static void reset_channels(struct seq_oss_synthinfo *info);
75 
76 /*
77  * global initialization
78  */
79 void __init
snd_seq_oss_synth_init(void)80 snd_seq_oss_synth_init(void)
81 {
82 	snd_use_lock_init(&midi_synth_dev.use_lock);
83 }
84 
85 /*
86  * registration of the synth device
87  */
88 int
snd_seq_oss_synth_probe(struct device * _dev)89 snd_seq_oss_synth_probe(struct device *_dev)
90 {
91 	struct snd_seq_device *dev = to_seq_dev(_dev);
92 	int i;
93 	struct seq_oss_synth *rec;
94 	struct snd_seq_oss_reg *reg = SNDRV_SEQ_DEVICE_ARGPTR(dev);
95 	unsigned long flags;
96 
97 	rec = kzalloc(sizeof(*rec), GFP_KERNEL);
98 	if (!rec)
99 		return -ENOMEM;
100 	rec->seq_device = -1;
101 	rec->synth_type = reg->type;
102 	rec->synth_subtype = reg->subtype;
103 	rec->nr_voices = reg->nvoices;
104 	rec->oper = reg->oper;
105 	rec->private_data = reg->private_data;
106 	rec->opened = 0;
107 	snd_use_lock_init(&rec->use_lock);
108 
109 	/* copy and truncate the name of synth device */
110 	strscpy(rec->name, dev->name, sizeof(rec->name));
111 
112 	/* registration */
113 	spin_lock_irqsave(&register_lock, flags);
114 	for (i = 0; i < max_synth_devs; i++) {
115 		if (synth_devs[i] == NULL)
116 			break;
117 	}
118 	if (i >= max_synth_devs) {
119 		if (max_synth_devs >= SNDRV_SEQ_OSS_MAX_SYNTH_DEVS) {
120 			spin_unlock_irqrestore(&register_lock, flags);
121 			pr_err("ALSA: seq_oss: no more synth slot\n");
122 			kfree(rec);
123 			return -ENOMEM;
124 		}
125 		max_synth_devs++;
126 	}
127 	rec->seq_device = i;
128 	synth_devs[i] = rec;
129 	spin_unlock_irqrestore(&register_lock, flags);
130 	dev->driver_data = rec;
131 #ifdef SNDRV_OSS_INFO_DEV_SYNTH
132 	if (i < SNDRV_CARDS)
133 		snd_oss_info_register(SNDRV_OSS_INFO_DEV_SYNTH, i, rec->name);
134 #endif
135 	return 0;
136 }
137 
138 
139 int
snd_seq_oss_synth_remove(struct device * _dev)140 snd_seq_oss_synth_remove(struct device *_dev)
141 {
142 	struct snd_seq_device *dev = to_seq_dev(_dev);
143 	int index;
144 	struct seq_oss_synth *rec = dev->driver_data;
145 	unsigned long flags;
146 
147 	spin_lock_irqsave(&register_lock, flags);
148 	for (index = 0; index < max_synth_devs; index++) {
149 		if (synth_devs[index] == rec)
150 			break;
151 	}
152 	if (index >= max_synth_devs) {
153 		spin_unlock_irqrestore(&register_lock, flags);
154 		pr_err("ALSA: seq_oss: can't unregister synth\n");
155 		return -EINVAL;
156 	}
157 	synth_devs[index] = NULL;
158 	if (index == max_synth_devs - 1) {
159 		for (index--; index >= 0; index--) {
160 			if (synth_devs[index])
161 				break;
162 		}
163 		max_synth_devs = index + 1;
164 	}
165 	spin_unlock_irqrestore(&register_lock, flags);
166 #ifdef SNDRV_OSS_INFO_DEV_SYNTH
167 	if (rec->seq_device < SNDRV_CARDS)
168 		snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_SYNTH, rec->seq_device);
169 #endif
170 
171 	snd_use_lock_sync(&rec->use_lock);
172 	kfree(rec);
173 
174 	return 0;
175 }
176 
177 
178 /*
179  */
180 static struct seq_oss_synth *
get_sdev(int dev)181 get_sdev(int dev)
182 {
183 	struct seq_oss_synth *rec;
184 	unsigned long flags;
185 
186 	spin_lock_irqsave(&register_lock, flags);
187 	rec = synth_devs[dev];
188 	if (rec)
189 		snd_use_lock_use(&rec->use_lock);
190 	spin_unlock_irqrestore(&register_lock, flags);
191 	return rec;
192 }
193 
194 
195 /*
196  * set up synth tables
197  */
198 
199 void
snd_seq_oss_synth_setup(struct seq_oss_devinfo * dp)200 snd_seq_oss_synth_setup(struct seq_oss_devinfo *dp)
201 {
202 	int i;
203 	struct seq_oss_synth *rec;
204 	struct seq_oss_synthinfo *info;
205 
206 	dp->max_synthdev = max_synth_devs;
207 	dp->synth_opened = 0;
208 	memset(dp->synths, 0, sizeof(dp->synths));
209 	for (i = 0; i < dp->max_synthdev; i++) {
210 		rec = get_sdev(i);
211 		if (rec == NULL)
212 			continue;
213 		if (rec->oper.open == NULL || rec->oper.close == NULL) {
214 			snd_use_lock_free(&rec->use_lock);
215 			continue;
216 		}
217 		info = &dp->synths[i];
218 		info->arg.app_index = dp->port;
219 		info->arg.file_mode = dp->file_mode;
220 		info->arg.seq_mode = dp->seq_mode;
221 		if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_SYNTH)
222 			info->arg.event_passing = SNDRV_SEQ_OSS_PROCESS_EVENTS;
223 		else
224 			info->arg.event_passing = SNDRV_SEQ_OSS_PASS_EVENTS;
225 		info->opened = 0;
226 		if (!try_module_get(rec->oper.owner)) {
227 			snd_use_lock_free(&rec->use_lock);
228 			continue;
229 		}
230 		if (rec->oper.open(&info->arg, rec->private_data) < 0) {
231 			module_put(rec->oper.owner);
232 			snd_use_lock_free(&rec->use_lock);
233 			continue;
234 		}
235 		info->nr_voices = rec->nr_voices;
236 		if (info->nr_voices > 0) {
237 			info->ch = kcalloc(info->nr_voices, sizeof(struct seq_oss_chinfo), GFP_KERNEL);
238 			if (!info->ch) {
239 				rec->oper.close(&info->arg);
240 				module_put(rec->oper.owner);
241 				snd_use_lock_free(&rec->use_lock);
242 				continue;
243 			}
244 			reset_channels(info);
245 		}
246 		info->opened++;
247 		rec->opened++;
248 		dp->synth_opened++;
249 		snd_use_lock_free(&rec->use_lock);
250 	}
251 }
252 
253 
254 /*
255  * set up synth tables for MIDI emulation - /dev/music mode only
256  */
257 
258 void
snd_seq_oss_synth_setup_midi(struct seq_oss_devinfo * dp)259 snd_seq_oss_synth_setup_midi(struct seq_oss_devinfo *dp)
260 {
261 	int i;
262 
263 	if (dp->max_synthdev >= SNDRV_SEQ_OSS_MAX_SYNTH_DEVS)
264 		return;
265 
266 	for (i = 0; i < dp->max_mididev; i++) {
267 		struct seq_oss_synthinfo *info;
268 		info = &dp->synths[dp->max_synthdev];
269 		if (snd_seq_oss_midi_open(dp, i, dp->file_mode) < 0)
270 			continue;
271 		info->arg.app_index = dp->port;
272 		info->arg.file_mode = dp->file_mode;
273 		info->arg.seq_mode = dp->seq_mode;
274 		info->arg.private_data = info;
275 		info->is_midi = 1;
276 		info->midi_mapped = i;
277 		info->arg.event_passing = SNDRV_SEQ_OSS_PASS_EVENTS;
278 		snd_seq_oss_midi_get_addr(dp, i, &info->arg.addr);
279 		info->opened = 1;
280 		midi_synth_dev.opened++;
281 		dp->max_synthdev++;
282 		if (dp->max_synthdev >= SNDRV_SEQ_OSS_MAX_SYNTH_DEVS)
283 			break;
284 	}
285 }
286 
287 
288 /*
289  * clean up synth tables
290  */
291 
292 void
snd_seq_oss_synth_cleanup(struct seq_oss_devinfo * dp)293 snd_seq_oss_synth_cleanup(struct seq_oss_devinfo *dp)
294 {
295 	int i;
296 	struct seq_oss_synth *rec;
297 	struct seq_oss_synthinfo *info;
298 
299 	if (snd_BUG_ON(dp->max_synthdev > SNDRV_SEQ_OSS_MAX_SYNTH_DEVS))
300 		return;
301 	for (i = 0; i < dp->max_synthdev; i++) {
302 		info = &dp->synths[i];
303 		if (! info->opened)
304 			continue;
305 		if (info->is_midi) {
306 			if (midi_synth_dev.opened > 0) {
307 				snd_seq_oss_midi_close(dp, info->midi_mapped);
308 				midi_synth_dev.opened--;
309 			}
310 		} else {
311 			rec = get_sdev(i);
312 			if (rec == NULL)
313 				continue;
314 			if (rec->opened > 0) {
315 				rec->oper.close(&info->arg);
316 				module_put(rec->oper.owner);
317 				rec->opened = 0;
318 			}
319 			snd_use_lock_free(&rec->use_lock);
320 		}
321 		kfree(info->sysex);
322 		info->sysex = NULL;
323 		kfree(info->ch);
324 		info->ch = NULL;
325 	}
326 	dp->synth_opened = 0;
327 	dp->max_synthdev = 0;
328 }
329 
330 static struct seq_oss_synthinfo *
get_synthinfo_nospec(struct seq_oss_devinfo * dp,int dev)331 get_synthinfo_nospec(struct seq_oss_devinfo *dp, int dev)
332 {
333 	if (dev < 0 || dev >= dp->max_synthdev)
334 		return NULL;
335 	dev = array_index_nospec(dev, SNDRV_SEQ_OSS_MAX_SYNTH_DEVS);
336 	return &dp->synths[dev];
337 }
338 
339 /*
340  * return synth device information pointer
341  */
342 static struct seq_oss_synth *
get_synthdev(struct seq_oss_devinfo * dp,int dev)343 get_synthdev(struct seq_oss_devinfo *dp, int dev)
344 {
345 	struct seq_oss_synth *rec;
346 	struct seq_oss_synthinfo *info = get_synthinfo_nospec(dp, dev);
347 
348 	if (!info)
349 		return NULL;
350 	if (!info->opened)
351 		return NULL;
352 	if (info->is_midi) {
353 		rec = &midi_synth_dev;
354 		snd_use_lock_use(&rec->use_lock);
355 	} else {
356 		rec = get_sdev(dev);
357 		if (!rec)
358 			return NULL;
359 	}
360 	if (! rec->opened) {
361 		snd_use_lock_free(&rec->use_lock);
362 		return NULL;
363 	}
364 	return rec;
365 }
366 
367 
368 /*
369  * reset note and velocity on each channel.
370  */
371 static void
reset_channels(struct seq_oss_synthinfo * info)372 reset_channels(struct seq_oss_synthinfo *info)
373 {
374 	int i;
375 	if (info->ch == NULL || ! info->nr_voices)
376 		return;
377 	for (i = 0; i < info->nr_voices; i++) {
378 		info->ch[i].note = -1;
379 		info->ch[i].vel = 0;
380 	}
381 }
382 
383 
384 /*
385  * reset synth device:
386  * call reset callback.  if no callback is defined, send a heartbeat
387  * event to the corresponding port.
388  */
389 void
snd_seq_oss_synth_reset(struct seq_oss_devinfo * dp,int dev)390 snd_seq_oss_synth_reset(struct seq_oss_devinfo *dp, int dev)
391 {
392 	struct seq_oss_synth *rec;
393 	struct seq_oss_synthinfo *info;
394 
395 	info = get_synthinfo_nospec(dp, dev);
396 	if (!info || !info->opened)
397 		return;
398 	if (info->sysex)
399 		info->sysex->len = 0; /* reset sysex */
400 	reset_channels(info);
401 	if (info->is_midi) {
402 		if (midi_synth_dev.opened <= 0)
403 			return;
404 		snd_seq_oss_midi_reset(dp, info->midi_mapped);
405 		/* reopen the device */
406 		snd_seq_oss_midi_close(dp, dev);
407 		if (snd_seq_oss_midi_open(dp, info->midi_mapped,
408 					  dp->file_mode) < 0) {
409 			midi_synth_dev.opened--;
410 			info->opened = 0;
411 			kfree(info->sysex);
412 			info->sysex = NULL;
413 			kfree(info->ch);
414 			info->ch = NULL;
415 		}
416 		return;
417 	}
418 
419 	rec = get_sdev(dev);
420 	if (rec == NULL)
421 		return;
422 	if (rec->oper.reset) {
423 		rec->oper.reset(&info->arg);
424 	} else {
425 		struct snd_seq_event ev;
426 		memset(&ev, 0, sizeof(ev));
427 		snd_seq_oss_fill_addr(dp, &ev, info->arg.addr.client,
428 				      info->arg.addr.port);
429 		ev.type = SNDRV_SEQ_EVENT_RESET;
430 		snd_seq_oss_dispatch(dp, &ev, 0, 0);
431 	}
432 	snd_use_lock_free(&rec->use_lock);
433 }
434 
435 
436 /*
437  * load a patch record:
438  * call load_patch callback function
439  */
440 int
snd_seq_oss_synth_load_patch(struct seq_oss_devinfo * dp,int dev,int fmt,const char __user * buf,int p,int c)441 snd_seq_oss_synth_load_patch(struct seq_oss_devinfo *dp, int dev, int fmt,
442 			    const char __user *buf, int p, int c)
443 {
444 	struct seq_oss_synth *rec;
445 	struct seq_oss_synthinfo *info;
446 	int rc;
447 
448 	info = get_synthinfo_nospec(dp, dev);
449 	if (!info)
450 		return -ENXIO;
451 
452 	if (info->is_midi)
453 		return 0;
454 	rec = get_synthdev(dp, dev);
455 	if (!rec)
456 		return -ENXIO;
457 
458 	if (rec->oper.load_patch == NULL)
459 		rc = -ENXIO;
460 	else
461 		rc = rec->oper.load_patch(&info->arg, fmt, buf, p, c);
462 	snd_use_lock_free(&rec->use_lock);
463 	return rc;
464 }
465 
466 /*
467  * check if the device is valid synth device and return the synth info
468  */
469 struct seq_oss_synthinfo *
snd_seq_oss_synth_info(struct seq_oss_devinfo * dp,int dev)470 snd_seq_oss_synth_info(struct seq_oss_devinfo *dp, int dev)
471 {
472 	struct seq_oss_synth *rec;
473 
474 	rec = get_synthdev(dp, dev);
475 	if (rec) {
476 		snd_use_lock_free(&rec->use_lock);
477 		return get_synthinfo_nospec(dp, dev);
478 	}
479 	return NULL;
480 }
481 
482 
483 /*
484  * receive OSS 6 byte sysex packet:
485  * the full sysex message will be sent if it reaches to the end of data
486  * (0xff).
487  */
488 int
snd_seq_oss_synth_sysex(struct seq_oss_devinfo * dp,int dev,unsigned char * buf,struct snd_seq_event * ev)489 snd_seq_oss_synth_sysex(struct seq_oss_devinfo *dp, int dev, unsigned char *buf, struct snd_seq_event *ev)
490 {
491 	int i, send;
492 	unsigned char *dest;
493 	struct seq_oss_synth_sysex *sysex;
494 	struct seq_oss_synthinfo *info;
495 
496 	info = snd_seq_oss_synth_info(dp, dev);
497 	if (!info)
498 		return -ENXIO;
499 
500 	sysex = info->sysex;
501 	if (sysex == NULL) {
502 		sysex = kzalloc(sizeof(*sysex), GFP_KERNEL);
503 		if (sysex == NULL)
504 			return -ENOMEM;
505 		info->sysex = sysex;
506 	}
507 
508 	send = 0;
509 	dest = sysex->buf + sysex->len;
510 	/* copy 6 byte packet to the buffer */
511 	for (i = 0; i < 6; i++) {
512 		if (buf[i] == 0xff) {
513 			send = 1;
514 			break;
515 		}
516 		dest[i] = buf[i];
517 		sysex->len++;
518 		if (sysex->len >= MAX_SYSEX_BUFLEN) {
519 			sysex->len = 0;
520 			sysex->skip = 1;
521 			break;
522 		}
523 	}
524 
525 	if (sysex->len && send) {
526 		if (sysex->skip) {
527 			sysex->skip = 0;
528 			sysex->len = 0;
529 			return -EINVAL; /* skip */
530 		}
531 		/* copy the data to event record and send it */
532 		ev->flags = SNDRV_SEQ_EVENT_LENGTH_VARIABLE;
533 		if (snd_seq_oss_synth_addr(dp, dev, ev))
534 			return -EINVAL;
535 		ev->data.ext.len = sysex->len;
536 		ev->data.ext.ptr = sysex->buf;
537 		sysex->len = 0;
538 		return 0;
539 	}
540 
541 	return -EINVAL; /* skip */
542 }
543 
544 /*
545  * fill the event source/destination addresses
546  */
547 int
snd_seq_oss_synth_addr(struct seq_oss_devinfo * dp,int dev,struct snd_seq_event * ev)548 snd_seq_oss_synth_addr(struct seq_oss_devinfo *dp, int dev, struct snd_seq_event *ev)
549 {
550 	struct seq_oss_synthinfo *info = snd_seq_oss_synth_info(dp, dev);
551 
552 	if (!info)
553 		return -EINVAL;
554 	snd_seq_oss_fill_addr(dp, ev, info->arg.addr.client,
555 			      info->arg.addr.port);
556 	return 0;
557 }
558 
559 
560 /*
561  * OSS compatible ioctl
562  */
563 int
snd_seq_oss_synth_ioctl(struct seq_oss_devinfo * dp,int dev,unsigned int cmd,unsigned long addr)564 snd_seq_oss_synth_ioctl(struct seq_oss_devinfo *dp, int dev, unsigned int cmd, unsigned long addr)
565 {
566 	struct seq_oss_synth *rec;
567 	struct seq_oss_synthinfo *info;
568 	int rc;
569 
570 	info = get_synthinfo_nospec(dp, dev);
571 	if (!info || info->is_midi)
572 		return -ENXIO;
573 	rec = get_synthdev(dp, dev);
574 	if (!rec)
575 		return -ENXIO;
576 	if (rec->oper.ioctl == NULL)
577 		rc = -ENXIO;
578 	else
579 		rc = rec->oper.ioctl(&info->arg, cmd, addr);
580 	snd_use_lock_free(&rec->use_lock);
581 	return rc;
582 }
583 
584 
585 /*
586  * send OSS raw events - SEQ_PRIVATE and SEQ_VOLUME
587  */
588 int
snd_seq_oss_synth_raw_event(struct seq_oss_devinfo * dp,int dev,unsigned char * data,struct snd_seq_event * ev)589 snd_seq_oss_synth_raw_event(struct seq_oss_devinfo *dp, int dev, unsigned char *data, struct snd_seq_event *ev)
590 {
591 	struct seq_oss_synthinfo *info;
592 
593 	info = snd_seq_oss_synth_info(dp, dev);
594 	if (!info || info->is_midi)
595 		return -ENXIO;
596 	ev->type = SNDRV_SEQ_EVENT_OSS;
597 	memcpy(ev->data.raw8.d, data, 8);
598 	return snd_seq_oss_synth_addr(dp, dev, ev);
599 }
600 
601 
602 /*
603  * create OSS compatible synth_info record
604  */
605 int
snd_seq_oss_synth_make_info(struct seq_oss_devinfo * dp,int dev,struct synth_info * inf)606 snd_seq_oss_synth_make_info(struct seq_oss_devinfo *dp, int dev, struct synth_info *inf)
607 {
608 	struct seq_oss_synth *rec;
609 	struct seq_oss_synthinfo *info = get_synthinfo_nospec(dp, dev);
610 
611 	if (!info)
612 		return -ENXIO;
613 
614 	if (info->is_midi) {
615 		struct midi_info minf;
616 		if (snd_seq_oss_midi_make_info(dp, info->midi_mapped, &minf))
617 			return -ENXIO;
618 		inf->synth_type = SYNTH_TYPE_MIDI;
619 		inf->synth_subtype = 0;
620 		inf->nr_voices = 16;
621 		inf->device = dev;
622 		strscpy(inf->name, minf.name, sizeof(inf->name));
623 	} else {
624 		rec = get_synthdev(dp, dev);
625 		if (!rec)
626 			return -ENXIO;
627 		inf->synth_type = rec->synth_type;
628 		inf->synth_subtype = rec->synth_subtype;
629 		inf->nr_voices = rec->nr_voices;
630 		inf->device = dev;
631 		strscpy(inf->name, rec->name, sizeof(inf->name));
632 		snd_use_lock_free(&rec->use_lock);
633 	}
634 	return 0;
635 }
636 
637 
638 #ifdef CONFIG_SND_PROC_FS
639 /*
640  * proc interface
641  */
642 void
snd_seq_oss_synth_info_read(struct snd_info_buffer * buf)643 snd_seq_oss_synth_info_read(struct snd_info_buffer *buf)
644 {
645 	int i;
646 	struct seq_oss_synth *rec;
647 
648 	snd_iprintf(buf, "\nNumber of synth devices: %d\n", max_synth_devs);
649 	for (i = 0; i < max_synth_devs; i++) {
650 		snd_iprintf(buf, "\nsynth %d: ", i);
651 		rec = get_sdev(i);
652 		if (rec == NULL) {
653 			snd_iprintf(buf, "*empty*\n");
654 			continue;
655 		}
656 		snd_iprintf(buf, "[%s]\n", rec->name);
657 		snd_iprintf(buf, "  type 0x%x : subtype 0x%x : voices %d\n",
658 			    rec->synth_type, rec->synth_subtype,
659 			    rec->nr_voices);
660 		snd_iprintf(buf, "  capabilities : ioctl %s / load_patch %s\n",
661 			    enabled_str((long)rec->oper.ioctl),
662 			    enabled_str((long)rec->oper.load_patch));
663 		snd_use_lock_free(&rec->use_lock);
664 	}
665 }
666 #endif /* CONFIG_SND_PROC_FS */
667