sound/core/seq/oss/seq_oss_rw.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * OSS compatible sequencer driver
   4  *
   5  * read/write/select interface to device file
   6  *
   7  * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
   8  */
   9
  10 #include "seq_oss_device.h"
  11 #include "seq_oss_readq.h"
  12 #include "seq_oss_writeq.h"
  13 #include "seq_oss_synth.h"
  14 #include <sound/seq_oss_legacy.h>
  15 #include "seq_oss_event.h"
  16 #include "seq_oss_timer.h"
  17 #include "../seq_clientmgr.h"
  18
  19
  20 /*
  21  * protoypes
  22  */
  23 static int insert_queue(struct seq_oss_devinfo *dp, union evrec *rec, struct file *opt);
  24
  25
  26 /*
  27  * read interface
  28  */
  29
  30 int
  31 snd_seq_oss_read(struct seq_oss_devinfo *dp, char __user *buf, int count)
  32 {
  33         struct seq_oss_readq *readq = dp->readq;
  34         int result = 0, err = 0;
  35         int ev_len;
  36         union evrec rec;
  37         unsigned long flags;
  38
  39         if (readq == NULL || ! is_read_mode(dp->file_mode))
  40                 return -ENXIO;
  41
  42         while (count >= SHORT_EVENT_SIZE) {
  43                 snd_seq_oss_readq_lock(readq, flags);
  44                 err = snd_seq_oss_readq_pick(readq, &rec);
  45                 if (err == -EAGAIN &&
  46                     !is_nonblock_mode(dp->file_mode) && result == 0) {
  47                         snd_seq_oss_readq_unlock(readq, flags);
  48                         snd_seq_oss_readq_wait(readq);
  49                         snd_seq_oss_readq_lock(readq, flags);
  50                         if (signal_pending(current))
  51                                 err = -ERESTARTSYS;
  52                         else
  53                                 err = snd_seq_oss_readq_pick(readq, &rec);
  54                 }
  55                 if (err < 0) {
  56                         snd_seq_oss_readq_unlock(readq, flags);
  57                         break;
  58                 }
  59                 ev_len = ev_length(&rec);
  60                 if (ev_len < count) {
  61                         snd_seq_oss_readq_unlock(readq, flags);
  62                         break;
  63                 }
  64                 snd_seq_oss_readq_free(readq);
  65                 snd_seq_oss_readq_unlock(readq, flags);
  66                 if (copy_to_user(buf, &rec, ev_len)) {
  67                         err = -EFAULT;
  68                         break;
  69                 }
  70                 result += ev_len;
  71                 buf += ev_len;
  72                 count -= ev_len;
  73         }
  74         return result > 0 ? result : err;
  75 }
  76
  77
  78 /*
  79  * write interface
  80  */
  81
  82 int
  83 snd_seq_oss_write(struct seq_oss_devinfo *dp, const char __user *buf, int count, struct file *opt)
  84 {
  85         int result = 0, err = 0;
  86         int ev_size, fmt;
  87         union evrec rec;
  88
  89         if (! is_write_mode(dp->file_mode) || dp->writeq == NULL)
  90                 return -ENXIO;
  91
  92         while (count >= SHORT_EVENT_SIZE) {
  93                 if (copy_from_user(&rec, buf, SHORT_EVENT_SIZE)) {
  94                         err = -EFAULT;
  95                         break;
  96                 }
  97                 if (rec.s.code == SEQ_FULLSIZE) {
  98                         /* load patch */
  99                         if (result > 0) {
 100                                 err = -EINVAL;
 101                                 break;
 102                         }
 103                         fmt = (*(unsigned short *)rec.c) & 0xffff;
 104                         /* FIXME the return value isn't correct */
 105                         return snd_seq_oss_synth_load_patch(dp, rec.s.dev,
 106                                                             fmt, buf, 0, count);
 107                 }
 108                 if (ev_is_long(&rec)) {
 109                         /* extended code */
 110                         if (rec.s.code == SEQ_EXTENDED &&
 111                             dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC) {
 112                                 err = -EINVAL;
 113                                 break;
 114                         }
 115                         ev_size = LONG_EVENT_SIZE;
 116                         if (count < ev_size)
 117                                 break;
 118                         /* copy the reset 4 bytes */
 119                         if (copy_from_user(rec.c + SHORT_EVENT_SIZE,
 120                                            buf + SHORT_EVENT_SIZE,
 121                                            LONG_EVENT_SIZE - SHORT_EVENT_SIZE)) {
 122                                 err = -EFAULT;
 123                                 break;
 124                         }
 125                 } else {
 126                         /* old-type code */
 127                         if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC) {
 128                                 err = -EINVAL;
 129                                 break;
 130                         }
 131                         ev_size = SHORT_EVENT_SIZE;
 132                 }
 133
 134                 /* insert queue */
 135                 if ((err = insert_queue(dp, &rec, opt)) < 0)
 136                         break;
 137
 138                 result += ev_size;
 139                 buf += ev_size;
 140                 count -= ev_size;
 141         }
 142         return result > 0 ? result : err;
 143 }
 144
 145
 146 /*
 147  * insert event record to write queue
 148  * return: 0 = OK, non-zero = NG
 149  */
 150 static int
 151 insert_queue(struct seq_oss_devinfo *dp, union evrec *rec, struct file *opt)
 152 {
 153         int rc = 0;
 154         struct snd_seq_event event;
 155
 156         /* if this is a timing event, process the current time */
 157         if (snd_seq_oss_process_timer_event(dp->timer, rec))
 158                 return 0; /* no need to insert queue */
 159
 160         /* parse this event */
 161         memset(&event, 0, sizeof(event));
 162         /* set dummy -- to be sure */
 163         event.type = SNDRV_SEQ_EVENT_NOTEOFF;
 164         snd_seq_oss_fill_addr(dp, &event, dp->addr.client, dp->addr.port);
 165
 166         if (snd_seq_oss_process_event(dp, rec, &event))
 167                 return 0; /* invalid event - no need to insert queue */
 168
 169         event.time.tick = snd_seq_oss_timer_cur_tick(dp->timer);
 170         if (dp->timer->realtime || !dp->timer->running)
 171                 snd_seq_oss_dispatch(dp, &event, 0, 0);
 172         else
 173                 rc = snd_seq_kernel_client_enqueue(dp->cseq, &event, opt,
 174                                                    !is_nonblock_mode(dp->file_mode));
 175         return rc;
 176 }
 177
 178
 179 /*
 180  * select / poll
 181  */
 182
 183 __poll_t
 184 snd_seq_oss_poll(struct seq_oss_devinfo *dp, struct file *file, poll_table * wait)
 185 {
 186         __poll_t mask = 0;
 187
 188         /* input */
 189         if (dp->readq && is_read_mode(dp->file_mode)) {
 190                 if (snd_seq_oss_readq_poll(dp->readq, file, wait))
 191                         mask |= EPOLLIN | EPOLLRDNORM;
 192         }
 193
 194         /* output */
 195         if (dp->writeq && is_write_mode(dp->file_mode)) {
 196                 if (snd_seq_kernel_client_write_poll(dp->cseq, file, wait))
 197                         mask |= EPOLLOUT | EPOLLWRNORM;
 198         }
 199         return mask;
 200 }