The tsdelta computation and error detection didn't handle the intialisation phase properly.
This patches fixes this by skipping the output timing validation when the SSRCs don't match.
Sponsored-by: On-Waves ehf --- openbsc/src/libmgcp/mgcp_network.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/openbsc/src/libmgcp/mgcp_network.c b/openbsc/src/libmgcp/mgcp_network.c index 75d39c1..06452a6 100644 --- a/openbsc/src/libmgcp/mgcp_network.c +++ b/openbsc/src/libmgcp/mgcp_network.c @@ -237,6 +237,15 @@ void mgcp_patch_and_count(struct mgcp_endpoint *endp, struct mgcp_rtp_state *sta state->jitter = 0; state->transit = arrival_time - timestamp; state->out_stream = state->in_stream; + state->out_stream.last_timestamp = timestamp; + state->out_stream.ssrc = rtp_hdr->ssrc - 1; /* SSRC change <=> initialisation */ + LOGP(DMGCP, LOGL_INFO, + "Initializing stream on 0x%x SSRC: %u timestamp: %u " + "from %s:%d in %d\n", + ENDPOINT_NUMBER(endp), state->in_stream.ssrc, + state->seq_offset, + inet_ntoa(addr->sin_addr), ntohs(addr->sin_port), + endp->conn_mode); } else if (state->in_stream.ssrc != rtp_hdr->ssrc) { int32_t tsdelta = state->out_stream.last_tsdelta; if (tsdelta == 0) { @@ -286,9 +295,10 @@ void mgcp_patch_and_count(struct mgcp_endpoint *endp, struct mgcp_rtp_state *sta }
/* Check again, whether the timestamps are still valid */ - check_rtp_timestamp(endp, &state->out_stream, rtp_end, addr, - seq, timestamp, "output", - &state->out_stream.last_tsdelta); + if (state->out_stream.ssrc == rtp_hdr->ssrc) + check_rtp_timestamp(endp, &state->out_stream, rtp_end, addr, + seq, timestamp, "output", + &state->out_stream.last_tsdelta);
/* * The below takes the shape of the validation from Appendix A. Check