client: add unified function to generate MGCP messages
currently the only way to generate MGCP messages is to use
mgcp_msg_crcx(), mgcp_msg_mdcx() and mgcp_msg_dlcx(). All
three function take a fixed set of parameters via their
parameter list. There is no way to add or leave away optional
parameters.
add function mgcp_msg_gen(), this function takes a unified
message struct. The struct features a presence bitmask which
allows to enable and disable parameters as needed. It is also
possible to add new parameters in the future without breaking
the API.
Depends: libosmocore I15e1af68616309555d0ed9ac5da027c9833d42e3
Change-Id: I29c5e2fb972896faeb771ba040f015592487fcbe
diff --git a/src/libosmo-mgcp-client/mgcp_client.c b/src/libosmo-mgcp-client/mgcp_client.c
index 1cd37be..c7cc989 100644
--- a/src/libosmo-mgcp-client/mgcp_client.c
+++ b/src/libosmo-mgcp-client/mgcp_client.c
@@ -23,6 +23,7 @@
#include <osmocom/core/write_queue.h>
#include <osmocom/core/msgb.h>
#include <osmocom/core/logging.h>
+#include <osmocom/core/byteswap.h>
#include <osmocom/mgcp_client/mgcp_client.h>
#include <osmocom/mgcp_client/mgcp_client_internal.h>
@@ -614,6 +615,109 @@
"C: %x\r\n", trans_id, rtp_endpoint, call_id);
}
+#define MGCP_CRCX_MANDATORY (MGCP_MSG_PRESENCE_ENDPOINT | \
+ MGCP_MSG_PRESENCE_CALL_ID | \
+ MGCP_MSG_PRESENCE_CONN_ID | \
+ MGCP_MSG_PRESENCE_CONN_MODE)
+#define MGCP_MDCX_MANDATORY (MGCP_MSG_PRESENCE_ENDPOINT | \
+ MGCP_MSG_PRESENCE_CONN_ID)
+#define MGCP_DLCX_MANDATORY (MGCP_MSG_PRESENCE_ENDPOINT)
+#define MGCP_AUEP_MANDATORY (MGCP_MSG_PRESENCE_ENDPOINT)
+#define MGCP_RSIP_MANDATORY 0 /* none */
+
+struct msgb *mgcp_msg_gen(struct mgcp_client *mgcp, struct mgcp_msg *mgcp_msg)
+{
+ mgcp_trans_id_t trans_id = mgcp_client_next_trans_id(mgcp);
+ uint32_t mandatory_mask;
+ struct msgb *msg = msgb_alloc_headroom(4096, 128, "MGCP tx");
+ int rc = 0;
+
+ msg->l2h = msg->data;
+ msg->cb[MSGB_CB_MGCP_TRANS_ID] = trans_id;
+
+ /* Add command verb */
+ switch (mgcp_msg->verb) {
+ case MGCP_VERB_CRCX:
+ mandatory_mask = MGCP_CRCX_MANDATORY;
+ rc += msgb_printf(msg, "CRCX %u", trans_id);
+ break;
+ case MGCP_VERB_MDCX:
+ mandatory_mask = MGCP_MDCX_MANDATORY;
+ rc += msgb_printf(msg, "MDCX %u", trans_id);
+ break;
+ case MGCP_VERB_DLCX:
+ mandatory_mask = MGCP_DLCX_MANDATORY;
+ rc += msgb_printf(msg, "DLCX %u", trans_id);
+ break;
+ case MGCP_VERB_AUEP:
+ mandatory_mask = MGCP_AUEP_MANDATORY;
+ rc += msgb_printf(msg, "AUEP %u", trans_id);
+ break;
+ case MGCP_VERB_RSIP:
+ mandatory_mask = MGCP_RSIP_MANDATORY;
+ rc += msgb_printf(msg, "RSIP %u", trans_id);
+ break;
+ default:
+ LOGP(DLMGCP, LOGL_ERROR,
+ "Invalid command verb, can not generate MGCP message\n");
+ msgb_free(msg);
+ return NULL;
+ }
+
+ /* Check if mandatory fields are missing */
+ if (!((mgcp_msg->presence & mandatory_mask) == mandatory_mask)) {
+ LOGP(DLMGCP, LOGL_ERROR,
+ "One or more missing mandatory fields, can not generate MGCP message\n");
+ msgb_free(msg);
+ return NULL;
+ }
+
+ /* Add endpoint name */
+ if (mgcp_msg->presence & MGCP_MSG_PRESENCE_ENDPOINT)
+ rc += msgb_printf(msg, " %s", mgcp_msg->endpoint);
+
+ /* Add protocol version */
+ rc += msgb_printf(msg, " MGCP 1.0\r\n");
+
+ /* Add call id */
+ if (mgcp_msg->presence & MGCP_MSG_PRESENCE_CALL_ID)
+ rc += msgb_printf(msg, "C: %x\r\n", mgcp_msg->call_id);
+
+ /* Add connection id */
+ if (mgcp_msg->presence & MGCP_MSG_PRESENCE_CONN_ID)
+ rc += msgb_printf(msg, "I: %u\r\n", mgcp_msg->conn_id);
+
+ /* Add local connection options */
+ if (mgcp_msg->presence & MGCP_MSG_PRESENCE_CONN_ID
+ && mgcp_msg->verb == MGCP_VERB_CRCX)
+ rc += msgb_printf(msg, "L: p:20, a:AMR, nt:IN\r\n");
+
+ /* Add mode */
+ if (mgcp_msg->presence & MGCP_MSG_PRESENCE_CONN_MODE)
+ rc +=
+ msgb_printf(msg, "M: %s\r\n",
+ mgcp_client_cmode_name(mgcp_msg->conn_mode));
+
+ /* Add RTP address and port (SDP) */
+ if (mgcp_msg->presence & MGCP_MSG_PRESENCE_AUDIO_IP
+ && mgcp_msg->presence & MGCP_MSG_PRESENCE_AUDIO_PORT) {
+ rc += msgb_printf(msg, "\r\n");
+ rc += msgb_printf(msg, "c=IN IP4 %s\r\n", mgcp_msg->audio_ip);
+ rc +=
+ msgb_printf(msg, "m=audio %u RTP/AVP 255\r\n",
+ mgcp_msg->audio_port);
+ }
+
+ if (rc != 0) {
+ LOGP(DLMGCP, LOGL_ERROR,
+ "message buffer to small, can not generate MGCP message\n");
+ msgb_free(msg);
+ msg = NULL;
+ }
+
+ return msg;
+}
+
struct mgcp_client_conf *mgcp_client_conf_actual(struct mgcp_client *mgcp)
{
return &mgcp->actual;