[ALSA] seq_midi_event: fix parsing of missing data bytes

Reorganize the encoder logic to prevent status bytes that appear where
data bytes are expected from being interpreted as data bytes.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
This commit is contained in:
Clemens Ladisch 2007-08-10 09:40:09 +02:00 committed by Jaroslav Kysela
parent 0b664f7206
commit bf8c1382c0
1 changed files with 41 additions and 39 deletions

View File

@ -65,32 +65,32 @@ static struct status_event_list {
void (*decode)(struct snd_seq_event *ev, unsigned char *buf);
} status_event[] = {
/* 0x80 - 0xef */
{SNDRV_SEQ_EVENT_NOTEOFF, 2, note_event, note_decode},
{SNDRV_SEQ_EVENT_NOTEON, 2, note_event, note_decode},
{SNDRV_SEQ_EVENT_KEYPRESS, 2, note_event, note_decode},
{SNDRV_SEQ_EVENT_CONTROLLER, 2, two_param_ctrl_event, two_param_decode},
{SNDRV_SEQ_EVENT_PGMCHANGE, 1, one_param_ctrl_event, one_param_decode},
{SNDRV_SEQ_EVENT_CHANPRESS, 1, one_param_ctrl_event, one_param_decode},
{SNDRV_SEQ_EVENT_PITCHBEND, 2, pitchbend_ctrl_event, pitchbend_decode},
{SNDRV_SEQ_EVENT_NOTEOFF, 2, note_event, note_decode},
{SNDRV_SEQ_EVENT_NOTEON, 2, note_event, note_decode},
{SNDRV_SEQ_EVENT_KEYPRESS, 2, note_event, note_decode},
{SNDRV_SEQ_EVENT_CONTROLLER, 2, two_param_ctrl_event, two_param_decode},
{SNDRV_SEQ_EVENT_PGMCHANGE, 1, one_param_ctrl_event, one_param_decode},
{SNDRV_SEQ_EVENT_CHANPRESS, 1, one_param_ctrl_event, one_param_decode},
{SNDRV_SEQ_EVENT_PITCHBEND, 2, pitchbend_ctrl_event, pitchbend_decode},
/* invalid */
{SNDRV_SEQ_EVENT_NONE, 0, NULL, NULL},
{SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL},
/* 0xf0 - 0xff */
{SNDRV_SEQ_EVENT_SYSEX, 1, NULL, NULL}, /* sysex: 0xf0 */
{SNDRV_SEQ_EVENT_QFRAME, 1, one_param_event, one_param_decode}, /* 0xf1 */
{SNDRV_SEQ_EVENT_SONGPOS, 2, songpos_event, songpos_decode}, /* 0xf2 */
{SNDRV_SEQ_EVENT_SONGSEL, 1, one_param_event, one_param_decode}, /* 0xf3 */
{SNDRV_SEQ_EVENT_NONE, 0, NULL, NULL}, /* 0xf4 */
{SNDRV_SEQ_EVENT_NONE, 0, NULL, NULL}, /* 0xf5 */
{SNDRV_SEQ_EVENT_TUNE_REQUEST, 0, NULL, NULL}, /* 0xf6 */
{SNDRV_SEQ_EVENT_NONE, 0, NULL, NULL}, /* 0xf7 */
{SNDRV_SEQ_EVENT_CLOCK, 0, NULL, NULL}, /* 0xf8 */
{SNDRV_SEQ_EVENT_NONE, 0, NULL, NULL}, /* 0xf9 */
{SNDRV_SEQ_EVENT_START, 0, NULL, NULL}, /* 0xfa */
{SNDRV_SEQ_EVENT_CONTINUE, 0, NULL, NULL}, /* 0xfb */
{SNDRV_SEQ_EVENT_STOP, 0, NULL, NULL}, /* 0xfc */
{SNDRV_SEQ_EVENT_NONE, 0, NULL, NULL}, /* 0xfd */
{SNDRV_SEQ_EVENT_SENSING, 0, NULL, NULL}, /* 0xfe */
{SNDRV_SEQ_EVENT_RESET, 0, NULL, NULL}, /* 0xff */
{SNDRV_SEQ_EVENT_SYSEX, 1, NULL, NULL}, /* sysex: 0xf0 */
{SNDRV_SEQ_EVENT_QFRAME, 1, one_param_event, one_param_decode}, /* 0xf1 */
{SNDRV_SEQ_EVENT_SONGPOS, 2, songpos_event, songpos_decode}, /* 0xf2 */
{SNDRV_SEQ_EVENT_SONGSEL, 1, one_param_event, one_param_decode}, /* 0xf3 */
{SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xf4 */
{SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xf5 */
{SNDRV_SEQ_EVENT_TUNE_REQUEST, 0, NULL, NULL}, /* 0xf6 */
{SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xf7 */
{SNDRV_SEQ_EVENT_CLOCK, 0, NULL, NULL}, /* 0xf8 */
{SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xf9 */
{SNDRV_SEQ_EVENT_START, 0, NULL, NULL}, /* 0xfa */
{SNDRV_SEQ_EVENT_CONTINUE, 0, NULL, NULL}, /* 0xfb */
{SNDRV_SEQ_EVENT_STOP, 0, NULL, NULL}, /* 0xfc */
{SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xfd */
{SNDRV_SEQ_EVENT_SENSING, 0, NULL, NULL}, /* 0xfe */
{SNDRV_SEQ_EVENT_RESET, 0, NULL, NULL}, /* 0xff */
};
static int extra_decode_ctrl14(struct snd_midi_event *dev, unsigned char *buf, int len,
@ -256,25 +256,27 @@ int snd_midi_event_encode_byte(struct snd_midi_event *dev, int c,
}
spin_lock_irqsave(&dev->lock, flags);
if (dev->qlen > 0) {
/* rest of command */
dev->buf[dev->read++] = c;
if (dev->type != ST_SYSEX)
dev->qlen--;
} else {
if ((c & 0x80) &&
(c != MIDI_CMD_COMMON_SYSEX_END || dev->type != ST_SYSEX)) {
/* new command */
dev->buf[0] = c;
if ((c & 0xf0) == 0xf0) /* system messages */
dev->type = (c & 0x0f) + ST_SPECIAL;
else
dev->type = (c >> 4) & 0x07;
dev->read = 1;
if (c & 0x80) {
dev->buf[0] = c;
if ((c & 0xf0) == 0xf0) /* special events */
dev->type = (c & 0x0f) + ST_SPECIAL;
else
dev->type = (c >> 4) & 0x07;
dev->qlen = status_event[dev->type].qlen;
} else {
/* process this byte as argument */
dev->qlen = status_event[dev->type].qlen;
} else {
if (dev->qlen > 0) {
/* rest of command */
dev->buf[dev->read++] = c;
if (dev->type != ST_SYSEX)
dev->qlen--;
} else {
/* running status */
dev->buf[1] = c;
dev->qlen = status_event[dev->type].qlen - 1;
dev->read = 2;
}
}
if (dev->qlen == 0) {