Re: [alsa-devel] [PATCH] amidi: add delay option

Felipe F. Tonello wrote:

This patch adds a new options to amidi tool to add a delay (in milliseconds) to each MIDI message.

This is very useful when sending firmware updates to a remote device via SysEx or any other use that requires this delay in between messages.

• case 0xf4:
• case 0xf5:

• return 0; /* ignore */
  

• case 0xf7:

• return 0; /* ignore */
  

Silent data loss is bad.

• case 0x00 ... 0x7f:

• return rstate_len ?: rstate_len - 1;
  

rstate_len - 1 == -1

• 		int len = message_length(*data);
  

• 		/* check for variable length */
  

• 		if (len == -1) {
  

• 			int i = 0;
  

• 			while (data[i++] != 0xf7);
  

Possible buffer overflow.

• 		if (len > 0 &&
  

• 		    (err = snd_rawmidi_write(output, data, len)) < 0) {
  

Same here.

The most robust way to find message boundaries probably would be a state machine. However, there is actually no requirement to find all message boundaries; the _actual_ requirement is to insert pauses between SysEx messages. So don't bother to try to parse everything; just search for F0 or F7.

Regards, Clemens