[Asterisk-Dev] stable chan_skinny crash + fix

[Vincent Sweeney]

Hi.

Attached is a patch to fix a crash in the stable branch chan_skinny 
module. I've had no time to see if the problems still exists in the 
lastest HEAD version.

Anyway a situation can occur where sub->rtp is NULL and passed to 
ast_rtp_read (BAD mmkay). No idea *why* it's NULL yet but the simple 
patch is stable for me.

Vince.
-------------- next part --------------
diff -Nru asterisk/channels/chan_skinny.c asterisk.new/channels/chan_skinny.c
--- asterisk/channels/chan_skinny.c	2005-01-23 03:35:40.000000000 +0000
+++ asterisk.new/channels/chan_skinny.c	2005-02-01 16:06:14.517006556 +0000
@@ -1576,16 +1576,20 @@
 static struct ast_frame *skinny_rtp_read(struct skinny_subchannel *sub)
 {
 	/* Retrieve audio/etc from channel.  Assumes sub->lock is already held. */
-	struct ast_frame *f;
-	f = ast_rtp_read(sub->rtp);
-	if (sub->owner) {
-		/* We already hold the channel lock */
-		if (f->frametype == AST_FRAME_VOICE) {
-			if (f->subclass != sub->owner->nativeformats) {
-				ast_log(LOG_DEBUG, "Oooh, format changed to %d\n", f->subclass);
-				sub->owner->nativeformats = f->subclass;
-				ast_set_read_format(sub->owner, sub->owner->readformat);
-				ast_set_write_format(sub->owner, sub->owner->writeformat);
+	static struct ast_frame null_frame = { AST_FRAME_NULL, };
+	struct ast_frame *f = &null_frame;
+	if (sub->rtp)
+	{
+		f = ast_rtp_read(sub->rtp);
+		if (sub->owner) {
+			/* We already hold the channel lock */
+			if (f->frametype == AST_FRAME_VOICE) {
+				if (f->subclass != sub->owner->nativeformats) {
+					ast_log(LOG_DEBUG, "Oooh, format changed to %d\n", f->subclass);
+					sub->owner->nativeformats = f->subclass;
+					ast_set_read_format(sub->owner, sub->owner->readformat);
+					ast_set_write_format(sub->owner, sub->owner->writeformat);
+				}
 			}
 		}
 	}