[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>
diff --git a/sound/core/seq/seq_midi_event.c b/sound/core/seq/seq_midi_event.c
index 45ba6fc..a15f5e6 100644
--- a/sound/core/seq/seq_midi_event.c
+++ b/sound/core/seq/seq_midi_event.c
@@ -65,32 +65,32 @@
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 @@
}
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) {