ALSA: ump: Copy safe string name to rawmidi

The UMP helper didn't set up the rawmidi name string by itself but
left it to the driver.  But since the only user (USB MIDI2 driver)
picks up the UMP info name string to the rawmidi name as default, it's
better to set up in the UMP core side.

Meanwhile, UMP receives the EP name string from the device, and it
might contain garbage letters.  We should purify the string to be
usable for the kernel as done previously for UMP Group names.

This implements the copy of the UMP info name string into the rawmidi
name at the creation of UMP EP object in a safe way to strip the
non-ASCII or non-printable characters.  Also, change the reference
from the legacy rawmidi and other places to rawmidi name field instead
of ump info; this assures the sane strings.

Signed-off-by: Takashi Iwai <[email protected]>
Link: https://patch.msgid.link/[email protected]

Author: tiwai

sound/core/ump.c

@@ -740,6 +740,13 @@ static int ump_handle_device_info_msg(struct snd_ump_endpoint *ump,
 	return 1; /* finished */
 }
 
+/* set up the core rawmidi name from UMP EP name string */
+static void ump_set_rawmidi_name(struct snd_ump_endpoint *ump)
+{
+	safe_copy_string(ump->core.name, sizeof(ump->core.name),
+			 ump->info.name, sizeof(ump->info.name));
+}
+
 /* handle EP name stream message; update the UMP name string */
 static int ump_handle_ep_name_msg(struct snd_ump_endpoint *ump,
 				  const union snd_ump_stream_msg *buf)
@@ -1067,6 +1074,8 @@ int snd_ump_parse_endpoint(struct snd_ump_endpoint *ump)
 	if (err < 0)
 		ump_dbg(ump, "Unable to get UMP EP name string\n");
 
+	ump_set_rawmidi_name(ump);
+
 	/* Request Endpoint Product ID */
 	err = ump_req_msg(ump, msg, UMP_STREAM_MSG_REQUEST_PRODUCT_ID,
 			  UMP_STREAM_MSG_STATUS_PRODUCT_ID);
@@ -1283,7 +1292,7 @@ static void update_legacy_substreams(struct snd_ump_endpoint *ump,
 		idx = ump->legacy_mapping[s->number];
 		name = ump->groups[idx].name;
 		if (!*name)
-			name = ump->info.name;
+			name = ump->core.name;
 		scnprintf(s->name, sizeof(s->name), "Group %d (%.16s)%s",
 			  idx + 1, name,
 			  ump->groups[idx].active ? "" : " [Inactive]");
@@ -1330,7 +1339,7 @@ int snd_ump_attach_legacy_rawmidi(struct snd_ump_endpoint *ump,
 		snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
 				    &snd_ump_legacy_output_ops);
 	snprintf(rmidi->name, sizeof(rmidi->name), "%.68s (MIDI 1.0)",
-		 ump->info.name);
+		 ump->core.name);
 	rmidi->info_flags = ump->core.info_flags & ~SNDRV_RAWMIDI_INFO_UMP;
 	rmidi->ops = &snd_ump_legacy_ops;
 	rmidi->private_data = ump;