res_rtp_asterisk: Free payload when error on insertion to data buffer

When the ast_data_buffer_put rejects to add a packet, for example because
the buffer already contains a packet with the same sequence number, the
payload will never be freed, resulting in a memory leak.

The data buffer will now return an error if this situation occurs
allowing the caller to free the payload. The res_rtp_asterisk module
has also been updated to do this.

ASTERISK-28826

Change-Id: Ie6c49495d1c921d5f997651c7d0f79646f095cf1

main/data_buffer.c

@@ -254,7 +254,7 @@ int ast_data_buffer_put(struct ast_data_buffer *buffer, size_t pos, void *payloa
 	AST_LIST_TRAVERSE_SAFE_END;
 
 	if (inserted == -1) {
-		return 0;
+		return -1;
 	}
 
 	if (!inserted) {

res/res_rtp_asterisk.c

@@ -4991,7 +4991,9 @@ static int rtp_raw_write(struct ast_rtp_instance *instance, struct ast_frame *fr
 			if (payload) {
 				payload->size = packet_len;
 				memcpy(payload->buf, rtpheader, packet_len);
-				ast_data_buffer_put(rtp->send_buffer, rtp->seqno, payload);
+				if (ast_data_buffer_put(rtp->send_buffer, rtp->seqno, payload) == -1) {
+					ast_free(payload);
+				}
 			}
 		}
 
@@ -7938,7 +7940,9 @@ static struct ast_frame *ast_rtp_read(struct ast_rtp_instance *instance, int rtc
 
 		payload->size = res;
 		memcpy(payload->buf, rtpheader, res);
-		ast_data_buffer_put(rtp->recv_buffer, seqno, payload);
+		if (ast_data_buffer_put(rtp->recv_buffer, seqno, payload) == -1) {
+			ast_free(payload);
+		}
 
 		/* If this sequence number is removed that means we had a gap and this packet has filled it in
 		 * some. Since it was part of the gap we will have already added any other missing sequence numbers