add X-Osmo-IGN MGCP header to ignore CallID
The format is
CRCX ...
C: ...
M: ...
X-Osmo-IGN: C
So far the only ignorable element is C, i.e. the CallID. Any other items may be
added in the future.
(I initially intended to also add '@' to ignore the endpoint name's domain
part, but in the osmo-mgw code base the domain part is verified long before any
additional headers are even parsed, so sparing that refactoring for now.)
The intention is that osmo-bsc will issue "X-Osmo-IGN: C" for all SCCPlite
calls, because we are unable to retrieve the CallID that the MSC sends to
osmo-mgw for the network side of the endpoint.
Testing with a specific SCCPlite MSC, I actually observe that all CallIDs are
1, even for concurrent calls. So, an alternative hacky solution would have been
to always pass CallID == 1 for SCCPlite connections from osmo-bsc.
Related: I257ad574d8060fef19afce9798bd8a5a7f8c99fe (osmo-bsc)
Change-Id: Id7ae275ffde8ea9389270cfe3db087ee8db00b51
diff --git a/include/osmocom/mgcp/mgcp_common.h b/include/osmocom/mgcp/mgcp_common.h
index eb6564f..b2c7370 100644
--- a/include/osmocom/mgcp/mgcp_common.h
+++ b/include/osmocom/mgcp/mgcp_common.h
@@ -49,6 +49,14 @@
MGCP_CONN_LOOPBACK = 4 | MGCP_CONN_RECV_SEND,
};
+#define MGCP_X_OSMO_IGN_HEADER "X-Osmo-IGN:"
+
+/* Values should be bitwise-OR-able */
+enum mgcp_x_osmo_ign {
+ MGCP_X_OSMO_IGN_NONE = 0,
+ MGCP_X_OSMO_IGN_CALLID = 1,
+};
+
/* Ensure that the msg->l2h is NUL terminated. */
static inline int mgcp_msg_terminate_nul(struct msgb *msg)
{
diff --git a/include/osmocom/mgcp/mgcp_endp.h b/include/osmocom/mgcp/mgcp_endp.h
index 3876794..d834c09 100644
--- a/include/osmocom/mgcp/mgcp_endp.h
+++ b/include/osmocom/mgcp/mgcp_endp.h
@@ -90,6 +90,9 @@
/*! Memorize if this endpoint was choosen by the MGW (wildcarded, true)
* or if the user has choosen the particular endpoint explicitly. */
bool wildcarded_req;
+
+ /*! MGCP_X_OSMO_IGN_* flags from 'X-Osmo-IGN:' header */
+ uint32_t x_osmo_ign;
};
/*! Extract endpoint number for a given endpoint */
diff --git a/include/osmocom/mgcp_client/mgcp_client.h b/include/osmocom/mgcp_client/mgcp_client.h
index ed2dfb0..6c478e8 100644
--- a/include/osmocom/mgcp_client/mgcp_client.h
+++ b/include/osmocom/mgcp_client/mgcp_client.h
@@ -11,6 +11,8 @@
#define MGCP_CLIENT_REMOTE_ADDR_DEFAULT "127.0.0.1"
#define MGCP_CLIENT_REMOTE_PORT_DEFAULT 2427
+#define MGCP_CLIENT_MGW_STR "Configure MGCP connection to Media Gateway\n"
+
struct msgb;
struct vty;
struct mgcp_client;
@@ -88,6 +90,7 @@
#define MGCP_MSG_PRESENCE_AUDIO_IP 0x0008
#define MGCP_MSG_PRESENCE_AUDIO_PORT 0x0010
#define MGCP_MSG_PRESENCE_CONN_MODE 0x0020
+#define MGCP_MSG_PRESENCE_X_OSMO_IGN 0x8000
struct mgcp_msg {
enum mgcp_verb verb;
@@ -104,6 +107,7 @@
unsigned int codecs_len;
struct ptmap ptmap[MGCP_MAX_CODECS];
unsigned int ptmap_len;
+ uint32_t x_osmo_ign;
};
void mgcp_client_conf_init(struct mgcp_client_conf *conf);
diff --git a/include/osmocom/mgcp_client/mgcp_client_fsm.h b/include/osmocom/mgcp_client/mgcp_client_fsm.h
index 81d3dea..bb07872 100644
--- a/include/osmocom/mgcp_client/mgcp_client_fsm.h
+++ b/include/osmocom/mgcp_client/mgcp_client_fsm.h
@@ -42,6 +42,11 @@
/*! RTP payload type map length (optional, only needed when payload
* types are used that differ from what IANA/3GPP defines) */
unsigned int ptmap_len;
+
+ /*! If nonzero, send 'X-Osmo-IGN:' header. This is useful e.g. for SCCPlite MSCs where the MSC is
+ * known to issue incoherent or unknown CallIDs / to issue CRCX commands with a different domain
+ * name than the BSC. An OsmoMGW will then ignore these and not fail on mismatches. */
+ uint32_t x_osmo_ign;
};
struct osmo_fsm_inst *mgcp_conn_create(struct mgcp_client *mgcp, struct osmo_fsm_inst *parent_fi, uint32_t parent_term_evt,