RTP: give meaningful error messages if something fails

In fact, it should probably be better to silently ignore all those
errors as opposed to aborting the entire processing queue?  But that's
for another patch...

1 files changed, 24 insertions, 8 deletions

diff --git a/src/pq_rtp.c b/src/pq_rtp.c
index 6860506..1a7edde 100644
--- a/src/pq_rtp.c
+++ b/src/pq_rtp.c
@@ -98,36 +98,52 @@ pq_cb_rtp_input(void *_state, uint8_t *out, const uint8_t *in)
 	int rv, x_len, payload_len;
 
 	rv = read(state->fd, buf, sizeof(buf));
-	if (rv <= 0)
+	if (rv <= 0) {
+		perror("RTP read");
 		return -1;
+	}
 
-	if (rv < sizeof(struct rtp_hdr))
+	if (rv < sizeof(struct rtp_hdr)) {
+		fprintf(stderr, "%d smaller than rtp header\n", rv);
 		return -1;
+	}
 
-	if (rtph->version != RTP_VERSION)
+	if (rtph->version != RTP_VERSION) {
+		fprintf(stderr, "unknown RTP version %u\n", rtph->version);
 		return -1;
+	}
 
 	payload = buf + sizeof(struct rtp_hdr) + (rtph->csrc_count << 2);
 	payload_len = rv - sizeof(struct rtp_hdr) - (rtph->csrc_count << 2);
-	if (payload_len < 0)
+	if (payload_len < 0) {
+		fprintf(stderr, "non-existant RTP payload length %d\n", payload_len);
 		return -1;
+	}
 
 	if (rtph->extension) {
-		if (payload_len < sizeof(struct rtp_x_hdr))
+		if (payload_len < sizeof(struct rtp_x_hdr)) {
+			fprintf(stderr, "short extension header: %d\n", payload_len);
 			return -1;
+		}
 		rtpxh = (struct rtp_x_hdr *)payload;
 		x_len = ntohs(rtpxh->length) * 4 + sizeof(struct rtp_x_hdr);
 		payload += x_len;
 		payload_len -= x_len;
-		if (payload_len < 0)
+		if (payload_len < 0) {
+			fprintf(stderr, "short RTP payload length %d\n", payload_len);
 			return -1;
+		}
 	}
 	if (rtph->padding) {
-		if (payload_len < 0)
+		if (payload_len < 0) {
+			fprintf(stderr, "padding but no payload length %d\n", payload_len);
 			return -1;
+		}
 		payload_len -= payload[payload_len -1];
-		if (payload_len < 0)
+		if (payload_len < 0) {
+			fprintf(stderr, "no payload left after padding %d\n", payload_len);
 			return -1;
+		}
 	}
 
 	state->ssrc = ntohl(rtph->ssrc);