mgcp: Do not detect the initial package as a wrap around
The Annex A code has a probation period but we don't have it. When
starting with seq_no==0 do not assume that the sequence numbers
have wrapped. Do it by moving the entire checking code into the
else.
diff --git a/openbsc/include/openbsc/mgcp_internal.h b/openbsc/include/openbsc/mgcp_internal.h
index 0ec18cd..434b46c 100644
--- a/openbsc/include/openbsc/mgcp_internal.h
+++ b/openbsc/include/openbsc/mgcp_internal.h
@@ -248,6 +248,11 @@
const char**subtype_name,
const char**fmtp_extra);
+/* internal RTP Annex A counting */
+void mgcp_rtp_annex_count(struct mgcp_endpoint *endp, struct mgcp_rtp_state *state,
+ const uint16_t seq, const int32_t transit,
+ const uint32_t ssrc);
+
enum {
MGCP_DEST_NET = 0,
MGCP_DEST_BTS,
diff --git a/openbsc/src/libmgcp/mgcp_network.c b/openbsc/src/libmgcp/mgcp_network.c
index 888ec6e..9def94e 100644
--- a/openbsc/src/libmgcp/mgcp_network.c
+++ b/openbsc/src/libmgcp/mgcp_network.c
@@ -336,7 +336,6 @@
const uint16_t seq, const int32_t transit,
const uint32_t ssrc)
{
- uint16_t udelta;
int32_t d;
/* initialize or re-initialize */
@@ -348,25 +347,27 @@
state->stats_jitter = 0;
state->stats_transit = transit;
state->stats_cycles = 0;
- }
+ } else {
+ uint16_t udelta;
- /*
- * The below takes the shape of the validation of
- * Appendix A. Check if there is something weird with
- * the sequence number, otherwise check for a wrap
- * around in the sequence number.
- * It can't wrap during the initialization so let's
- * skip it here. The Appendix A probably doesn't have
- * this issue because of the probation.
- */
- udelta = seq - state->stats_max_seq;
- if (udelta < RTP_MAX_DROPOUT) {
- if (seq < state->stats_max_seq)
- state->stats_cycles += RTP_SEQ_MOD;
- } else if (udelta <= RTP_SEQ_MOD - RTP_MAX_MISORDER) {
- LOGP(DMGCP, LOGL_NOTICE,
- "RTP seqno made a very large jump on 0x%x delta: %u\n",
- ENDPOINT_NUMBER(endp), udelta);
+ /*
+ * The below takes the shape of the validation of
+ * Appendix A. Check if there is something weird with
+ * the sequence number, otherwise check for a wrap
+ * around in the sequence number.
+ * It can't wrap during the initialization so let's
+ * skip it here. The Appendix A probably doesn't have
+ * this issue because of the probation.
+ */
+ udelta = seq - state->stats_max_seq;
+ if (udelta < RTP_MAX_DROPOUT) {
+ if (seq < state->stats_max_seq)
+ state->stats_cycles += RTP_SEQ_MOD;
+ } else if (udelta <= RTP_SEQ_MOD - RTP_MAX_MISORDER) {
+ LOGP(DMGCP, LOGL_NOTICE,
+ "RTP seqno made a very large jump on 0x%x delta: %u\n",
+ ENDPOINT_NUMBER(endp), udelta);
+ }
}
/*
diff --git a/openbsc/tests/mgcp/mgcp_test.c b/openbsc/tests/mgcp/mgcp_test.c
index e145c6a..db2f4b3 100644
--- a/openbsc/tests/mgcp/mgcp_test.c
+++ b/openbsc/tests/mgcp/mgcp_test.c
@@ -998,6 +998,45 @@
talloc_free(cfg);
}
+static void test_no_cycle(void)
+{
+ struct mgcp_config *cfg;
+ struct mgcp_endpoint *endp;
+
+ printf("Testing no sequence flow on initial packet\n");
+
+ cfg = mgcp_config_alloc();
+ cfg->trunk.number_endpoints = 64;
+ mgcp_endpoints_allocate(&cfg->trunk);
+
+ endp = &cfg->trunk.endpoints[1];
+ OSMO_ASSERT(endp->net_state.stats_initialized == 0);
+
+ mgcp_rtp_annex_count(endp, &endp->net_state, 0, 0, 2342);
+ OSMO_ASSERT(endp->net_state.stats_initialized == 1);
+ OSMO_ASSERT(endp->net_state.stats_cycles == 0);
+ OSMO_ASSERT(endp->net_state.stats_max_seq == 0);
+
+ mgcp_rtp_annex_count(endp, &endp->net_state, 1, 0, 2342);
+ OSMO_ASSERT(endp->net_state.stats_initialized == 1);
+ OSMO_ASSERT(endp->net_state.stats_cycles == 0);
+ OSMO_ASSERT(endp->net_state.stats_max_seq == 1);
+
+ /* now jump.. */
+ mgcp_rtp_annex_count(endp, &endp->net_state, UINT16_MAX, 0, 2342);
+ OSMO_ASSERT(endp->net_state.stats_initialized == 1);
+ OSMO_ASSERT(endp->net_state.stats_cycles == 0);
+ OSMO_ASSERT(endp->net_state.stats_max_seq == UINT16_MAX);
+
+ /* and wrap */
+ mgcp_rtp_annex_count(endp, &endp->net_state, 0, 0, 2342);
+ OSMO_ASSERT(endp->net_state.stats_initialized == 1);
+ OSMO_ASSERT(endp->net_state.stats_cycles == UINT16_MAX + 1);
+ OSMO_ASSERT(endp->net_state.stats_max_seq == 0);
+
+ talloc_free(cfg);
+}
+
int main(int argc, char **argv)
{
osmo_init_logging(&log_info);
@@ -1014,6 +1053,7 @@
test_packet_error_detection(0, 1);
test_packet_error_detection(1, 1);
test_multilple_codec();
+ test_no_cycle();
printf("Done\n");
return EXIT_SUCCESS;
diff --git a/openbsc/tests/mgcp/mgcp_test.ok b/openbsc/tests/mgcp/mgcp_test.ok
index a25bed4..6ca82af 100644
--- a/openbsc/tests/mgcp/mgcp_test.ok
+++ b/openbsc/tests/mgcp/mgcp_test.ok
@@ -475,4 +475,5 @@
Out TS change: 160, dTS: 160, Seq change: 1, TS Err change: in +0, out +0
Stats: Jitter = 6810, Transit = -144000
Testing multiple payload types
+Testing no sequence flow on initial packet
Done