Introduce support for libosmo-mgcp-client MGW pooling

Change-Id: I7670ba56fe989706579224a364595fdd4b4708ff

include/osmocom/msc/gsm_data.h

@@ -16,6 +16,7 @@
 #include <osmocom/crypt/utran_cipher.h>
 
 #include <osmocom/mgcp_client/mgcp_client.h>
+#include <osmocom/mgcp_client/mgcp_client_pool.h>
 
 #include <osmocom/msc/msc_common.h>
 #include <osmocom/msc/neighbor_ident.h>
@@ -216,7 +217,9 @@ struct gsm_network {
 	struct {
 		struct osmo_tdef *tdefs;
 		struct mgcp_client_conf conf;
-		struct mgcp_client *client;
+		/* MGW pool, also includes the single MGCP client as fallback if no
+		 * pool is configured. */
+		struct mgcp_client_pool *mgw_pool;
 	} mgw;
 
 	struct {

include/osmocom/msc/vty.h

@@ -25,6 +25,7 @@ enum bsc_vty_node {
 	HLR_NODE,
 	CFG_SGS_NODE,
 	SMSC_NODE,
+	MGW_NODE,
 };
 
 int bsc_vty_init_extra(void);

src/libmsc/call_leg.c

@@ -17,6 +17,7 @@
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */
+#include <asm-generic/errno-base.h>
 #include <osmocom/core/fsm.h>
 #include <osmocom/mgcp_client/mgcp_client_endpoint_fsm.h>
 
@@ -275,10 +276,17 @@ int call_leg_ensure_rtp_alloc(struct call_leg *cl, enum rtp_direction dir, uint3
 	if (cl->rtp[dir])
 		return 0;
 
-	if (!cl->mgw_endpoint)
+	if (!cl->mgw_endpoint) {
+		struct mgcp_client *mgcp_client = mgcp_client_pool_get(gsmnet->mgw.mgw_pool);
+		if (!mgcp_client) {
+			LOG_CALL_LEG(cl, LOGL_ERROR,
+				     "cannot ensure MGW endpoint -- no MGW configured, check configuration!\n");
+			return -ENODEV;
+		}
 		cl->mgw_endpoint = osmo_mgcpc_ep_alloc(cl->fi, CALL_LEG_EV_MGW_ENDPOINT_GONE,
-						       gsmnet->mgw.client, gsmnet->mgw.tdefs, cl->fi->id,
-						       "%s", mgcp_client_rtpbridge_wildcard(gsmnet->mgw.client));
+						       mgcp_client, gsmnet->mgw.tdefs, cl->fi->id,
+						       "%s", mgcp_client_rtpbridge_wildcard(mgcp_client));
+	}
 	if (!cl->mgw_endpoint) {
 		LOG_CALL_LEG(cl, LOGL_ERROR, "failed to setup MGW endpoint\n");
 		return -EIO;

src/libmsc/msc_vty.c

@@ -2033,6 +2033,8 @@ void msc_vty_init(struct gsm_network *msc_network)
 	install_element(GSMNET_NODE, &cfg_net_no_per_loc_upd_cmd);
 	install_element(GSMNET_NODE, &cfg_net_call_wait_cmd);
 	install_element(GSMNET_NODE, &cfg_net_no_call_wait_cmd);
+	mgcp_client_pool_vty_init(GSMNET_NODE, MGW_NODE, " ", msc_network->mgw.mgw_pool);
+
 
 	install_element(CONFIG_NODE, &cfg_msc_cmd);
 	install_node(&msc_node, config_write_msc);
@@ -2066,7 +2068,9 @@ void msc_vty_init(struct gsm_network *msc_network)
 	/* Timer configuration commands (generic osmo_tdef API) */
 	osmo_tdef_vty_groups_init(MSC_NODE, msc_tdef_group);
 
+	/* Deprecated: Old MGCP config without pooling support in MSC node: */
 	mgcp_client_vty_init(msc_network, MSC_NODE, &msc_network->mgw.conf);
+
 #ifdef BUILD_IU
 	ranap_iu_vty_init(MSC_NODE, (enum ranap_nsap_addr_enc*)&msc_network->iu.rab_assign_addr_enc);
 #endif

src/osmo-msc/msc_main.c

@@ -256,6 +256,7 @@ struct gsm_network *msc_network_alloc(void *ctx,
 						  MSC_HLR_REMOTE_IP_DEFAULT);
 	net->gsup_server_port = MSC_HLR_REMOTE_PORT_DEFAULT;
 
+	net->mgw.mgw_pool = mgcp_client_pool_alloc(net);
 	mgcp_client_conf_init(&net->mgw.conf);
 	net->call_waiting = true;
 	net->lcls_permitted = false;
@@ -546,6 +547,41 @@ extern void *tall_gsms_ctx;
 extern void *tall_call_ctx;
 extern void *tall_trans_ctx;
 
+static int msc_mgw_setup(void)
+{
+	struct mgcp_client *mgcp_client_single;
+	unsigned int pool_members_initalized;
+
+	/* Initialize MGW pool. This initalizes and connects all MGCP clients that are currently configured in
+	 * the pool. Adding additional MGCP clients to the pool is possible but the user has to configure and
+	 * (re)connect them manually from the VTY. */
+	pool_members_initalized = mgcp_client_pool_connect(msc_network->mgw.mgw_pool);
+	if (pool_members_initalized) {
+		LOGP(DMSC, LOGL_NOTICE,
+		     "MGW pool with %u pool members configured, (ignoring MGW configuration in VTY node 'msc').\n",
+		     pool_members_initalized);
+		return 0;
+	}
+
+	/* Initialize and connect a single MGCP client. This MGCP client will appear as the one and only pool
+	 * member if there is no MGW pool configured. */
+	LOGP(DMSC, LOGL_NOTICE, "No MGW pool configured, using MGW configuration in VTY node 'msc'\n");
+	mgcp_client_single = mgcp_client_init(msc_network, &msc_network->mgw.conf);
+	if (!mgcp_client_single) {
+		LOGP(DMSC, LOGL_ERROR, "MGW (single) client initalization failed\n");
+		return -EINVAL;
+	}
+	if (mgcp_client_connect(mgcp_client_single)) {
+		LOGP(DMSC, LOGL_ERROR, "MGW (single) connect failed at (%s:%u)\n",
+		     msc_network->mgw.conf.remote_addr,
+		     msc_network->mgw.conf.remote_port);
+		return -EINVAL;
+	}
+	mgcp_client_pool_register_single(msc_network->mgw.mgw_pool, mgcp_client_single);
+
+	return 0;
+}
+
 int main(int argc, char **argv)
 {
 	int rc;
@@ -705,13 +741,8 @@ TODO: we probably want some of the _net_ ctrl commands from bsc_base_ctrl_cmds_i
 	if (sms_queue_start(msc_network) != 0)
 		return -1;
 
-	msc_network->mgw.client = mgcp_client_init(
-			msc_network, &msc_network->mgw.conf);
-
-	if (mgcp_client_connect(msc_network->mgw.client)) {
-		fprintf(stderr, "MGCPGW connect failed\n");
+	if (msc_mgw_setup() != 0)
 		return 7;
-	}
 
 	if (ss7_setup(tall_msc_ctx, &sccp_a, &sccp_iu)) {
 		fprintf(stderr, "Setting up SCCP client failed.\n");

tests/msc_vlr/msc_vlr_tests.c

@@ -1136,6 +1136,7 @@ static void run_tests(int nr)
 struct gsm_network *test_net(void *ctx)
 {
 	struct gsm_network *net = gsm_network_init(ctx, mncc_recv);
+	struct mgcp_client *client;
 
 	net->gsup_server_addr_str = talloc_strdup(net, "no_gsup_server");
 	net->gsup_server_port = 0;
@@ -1172,8 +1173,9 @@ struct gsm_network *test_net(void *ctx)
 	net->mgw.tdefs = g_mgw_tdefs;
 	mgcp_client_conf_init(&net->mgw.conf);
 	net->mgw.tdefs = g_mgw_tdefs;
-	net->mgw.client = mgcp_client_init(net, &net->mgw.conf);
-
+	net->mgw.mgw_pool = mgcp_client_pool_alloc(net);
+	client = mgcp_client_init(net, &net->mgw.conf);
+	mgcp_client_pool_register_single(net->mgw.mgw_pool, client);
 	return net;
 }