mgcp: Only patch the header if we had a change in SSRC
diff --git a/openbsc/include/openbsc/mgcp_internal.h b/openbsc/include/openbsc/mgcp_internal.h
index f6f8d6e..2d9629a 100644
--- a/openbsc/include/openbsc/mgcp_internal.h
+++ b/openbsc/include/openbsc/mgcp_internal.h
@@ -38,6 +38,7 @@
struct mgcp_rtp_state {
int initialized;
+ int patch;
uint32_t orig_ssrc;
uint32_t ssrc;
diff --git a/openbsc/src/mgcp/mgcp_network.c b/openbsc/src/mgcp/mgcp_network.c
index b5e2cdd..2abc6b5 100644
--- a/openbsc/src/mgcp/mgcp_network.c
+++ b/openbsc/src/mgcp/mgcp_network.c
@@ -116,17 +116,20 @@
state->ssrc = rtp_hdr->ssrc;
state->seq_offset = (state->seq_no + 1) - seq;
state->timestamp_offset = state->last_timestamp - timestamp;
+ state->patch = 1;
LOGP(DMGCP, LOGL_NOTICE, "The SSRC changed... SSRC: %u offset: %d\n",
state->ssrc, state->seq_offset);
}
/* apply the offset and store it back to the packet */
- seq += state->seq_offset;
- rtp_hdr->sequence = htons(seq);
- rtp_hdr->ssrc = state->orig_ssrc;
+ if (state->patch) {
+ seq += state->seq_offset;
+ rtp_hdr->sequence = htons(seq);
+ rtp_hdr->ssrc = state->orig_ssrc;
- timestamp += state->timestamp_offset;
- rtp_hdr->timestamp = htonl(timestamp);
+ timestamp += state->timestamp_offset;
+ rtp_hdr->timestamp = htonl(timestamp);
+ }
/* seq changed, now compare if we have lost something */
if (state->seq_no + 1u != seq)