A dedicated OML router program (osmobts-omlrouter)

The idea of this OML router is to be the entity that connects
the OML link to the BSC.  osmo-bts as well as other programs like
sysmobts-mgr and possibly more will then connect to the OML-router
rather than the BSC.

The point is that those "OML clients" can then register for certain
OML messages (particularly the managed objects like TRX, etc.) which
then get routed to them.

This is particularly useful in the context of 'stacked' multi-TRX
BTSs, where we will have two osmo-bts processes, one on each of the
TRX, both connecting OML to the oml-router.  Through their respective
subscription of the baseband transceiver OML object, they will get
routed the IPA CONNECT RSL message from the BSC, and both osmo-bts
processes will establish independent RSL connections to the BSC.

1 files changed, 294 insertions, 0 deletions

diff --git a/src/common/oml_routing.c b/src/common/oml_routing.c
new file mode 100644
index 00000000..3cab76ee
--- /dev/null
+++ b/src/common/oml_routing.c
@@ -0,0 +1,294 @@
+/* OML Message routing for osmo-bts */
+
+/* (C) 2014 by Harald Welte <laforge@gnumonks.org>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <stdint.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/utils.h>
+
+#include <osmocom/gsm/abis_nm.h>
+#include <osmocom/gsm/protocol/gsm_12_21.h>
+
+#include <osmocom/vty/vty.h>
+#include <osmocom/vty/command.h>
+
+#include <osmo-bts/logging.h>
+#include <osmo-bts/oml_routing.h>
+
+
+/* an OML router instance */
+struct oml_routing_inst {
+	struct llist_head routes;
+	void *priv;
+};
+
+/* FIXME: This must go! */
+static struct oml_routing_inst *g_inst;
+
+/* match given routing key against given route */
+static int oml_route_match(const struct oml_routing_key *key,
+			   const struct oml_route *route)
+{
+	if (route->flags & OML_RTF_MDISC)
+		if (route->key.mdisc != key->mdisc)
+			return 0;
+
+	if (route->flags & OML_RTF_OBJ_CLASS) {
+		if (route->key.obj_class != key->obj_class)
+			return 0;
+		if (route->key.obj_class == ABIS_OM_MDISC_MANUF &&
+		    route->flags & OML_RTF_VENDOR) {
+			if (route->key.vendor_lv[0] != key->vendor_lv[0])
+				return 0;
+			if (memcmp(route->key.vendor_lv+1, key->vendor_lv+1,
+				   OSMO_MIN(sizeof(route->key.vendor_lv)-1,
+					    route->key.vendor_lv[0])))
+				return 0;
+		}
+	}
+
+	if (route->flags & OML_RTF_BTS_NR)
+		if (route->key.obj_inst.bts_nr != key->obj_inst.bts_nr)
+			return 0;
+
+	if (route->flags & OML_RTF_TRX_NR)
+		if (route->key.obj_inst.trx_nr != key->obj_inst.trx_nr)
+			return 0;
+
+	if (route->flags & OML_RTF_TS_NR)
+		if (route->key.obj_inst.ts_nr != key->obj_inst.ts_nr)
+			return 0;
+
+	return 1;
+}
+
+/* are two given routes identical? */
+static int oml_route_ident(const struct oml_route *a, const struct oml_route *b)
+{
+	if (a->flags != b->flags)
+		return 0;
+
+	return oml_route_match(&a->key, b);
+}
+
+/* add a route from a router instance */
+int oml_route_add(struct oml_routing_inst *inst, const struct oml_route *route,
+		  struct oml_client *client)
+{
+	struct oml_route_entry *e;
+
+	llist_for_each_entry(e, &inst->routes, list) {
+		if (oml_route_ident(route, &e->route))
+			return -EEXIST;
+	}
+
+	e = talloc_zero(inst, struct oml_route_entry);
+	memcpy(&e->route, route, sizeof(e->route));
+	e->client = client;
+	/* FIXME: insert in order of integer of routing_flags */
+	llist_add(&e->list, &inst->routes);
+
+	return 0;
+}
+
+/* delete a route from a router instance */
+int oml_route_del(struct oml_routing_inst *inst, const struct oml_route *route)
+{
+	struct oml_route_entry *e;
+
+	/* no safe iteration needed as we stop at first match */
+	llist_for_each_entry(e, &inst->routes, list) {
+		if (oml_route_ident(route, &e->route)) {
+			llist_del(&e->list);
+			talloc_free(e);
+			return 1;
+		}
+	}
+
+	return -ENODEV;
+}
+
+int oml_route_del_client(struct oml_routing_inst *inst,
+			 const struct oml_client *client)
+{
+	struct oml_route_entry *e, *f;
+	int num = 0;
+
+	/* no safe iteration needed as we stop at first match */
+	llist_for_each_entry_safe(e, f, &inst->routes, list) {
+		if (e->client == client) {
+			llist_del(&e->list);
+			talloc_free(e);
+			num++;
+		}
+	}
+	return num;
+}
+
+
+/* perform routing of 'key' against router instance */
+void *oml_route(struct oml_routing_inst *inst,
+		const struct oml_routing_key *key)
+{
+	struct oml_route_entry *e;
+
+	llist_for_each_entry(e, &inst->routes, list) {
+		if (oml_route_match(key, &e->route))
+			return e->client;
+	}
+
+	return NULL;
+}
+
+DEFUN(show_oml_routing, show_oml_routing_cmd,
+	"show oml-routes",
+	SHOW_STR "Show the currently configured OML routing")
+{
+	struct oml_route_entry *e;
+
+	llist_for_each_entry(e, &g_inst->routes, list) {
+		struct oml_route *rt = &e->route;
+
+		vty_out(vty, " %s OC=%s INST=(%02x/%02x/%02x) -> %s/%s%s",
+			rt->flags & OML_RTF_MDISC ?
+				get_value_string(abis_nm_msg_disc_names,
+						 rt->key.mdisc) : "ANY",
+			rt->flags & OML_RTF_OBJ_CLASS ?
+				get_value_string(abis_nm_obj_class_names,
+						 rt->key.obj_class) : "ANY",
+			rt->flags & OML_RTF_BTS_NR ? rt->key.obj_inst.bts_nr : 255,
+			rt->flags & OML_RTF_TRX_NR ? rt->key.obj_inst.trx_nr : 255,
+			rt->flags & OML_RTF_TS_NR ? rt->key.obj_inst.ts_nr : 255,
+			oml_route_client_addr(e->client),
+			oml_route_client_name(e->client), VTY_NEWLINE);
+	}
+	return CMD_SUCCESS;
+}
+
+#define MDISC_STR "(any|fom|mmi|trau|manuf|<0-255>)"
+#define CLASS_STR "(any|site-manager|bts|radio-carrier|baseband-transceiver|channel|gprs-nse|gprs-cell|gprs-nsvc|<0-255>)"
+
+#define OMLROUTE_CMD "oml-route (add|del) mdisc "MDISC_STR" class "CLASS_STR" bts (any|<0-255>) trx (any|<0-255>]) ts (any|<0-255>) DEST"
+
+#define OMLROUTE_HELP	\
+	"OML-Routing\n"	\
+	"Add a route\n"	\
+	"Delete a route\n" \
+	"Message Discriminator\n" \
+	"Message Discriminator: Match any message discriminator\n" \
+	"Message Discriminator: Formatted OML messages\n" \
+	"Message Discriminator: Man-Machine-Interface OML messages\n" \
+	"Message Discriminator: Transcoder OML Message\n" \
+	"Message Discriminator: Manufacturer-specific OML messages\n" \
+	"Message Discriminator: Specific numeric message discrimniator\n" \
+	"Object Class\n" \
+	"Object Class: Match any object class\n" \
+	"Object Class: Site Manager\n" \
+	"Object Class: Base Transceiver Station\n" \
+	"Object Class: Radio Carrier\n" \
+	"Object Class: Baseband Transceiver\n" \
+	"Object Class: Channel (Um Timeslot)\n" \
+	"Object Class: GPRS NS Entity\n" \
+	"Object Class: GPRS Cell\n" \
+	"Object Class: GPRS NS Virtual Circuit\n" \
+	"Object Class: Specific numeric object class\n" \
+	"Object Instance(BTS)\n" \
+	"Object Instance(BTS): Any BTS number\n" \
+	"Object Instance(BTS): Specific BTS number\n" \
+	"Object Instance(TRX)\n" \
+	"Object Instance(TRX): Any TRX number\n" \
+	"Object Instance(TRX): Specific TRX number\n" \
+	"Object Instance(TS)\n" \
+	"Object Instance(TS): Any TS number\n" \
+	"Object Instance(TS): Specific TS number\n" \
+	"Name of destination for this route\n"
+
+DEFUN(cfg_omlr_route, cfg_omlr_route_cmd,
+	OMLROUTE_CMD, OMLROUTE_HELP)
+{
+	struct oml_route _r, *r = &_r;
+	int rc;
+
+	memset(r, 0, sizeof(*r));
+
+	if (strcmp(argv[1], "any")) {
+		r->flags |= OML_RTF_MDISC;
+		rc = get_string_value(abis_nm_msg_disc_names, argv[1]);
+		if (rc < 0)
+			rc = atoi(argv[1]);
+		r->key.mdisc = rc;
+	}
+
+	if (strcmp(argv[2], "any")) {
+		r->flags |= OML_RTF_OBJ_CLASS;
+		rc = get_string_value(abis_nm_obj_class_names, argv[2]);
+		if (rc < 0)
+			rc = atoi(argv[2]);
+		r->key.obj_class = rc;
+	}
+
+	if (strcmp(argv[3], "any")) {
+		r->flags |= OML_RTF_BTS_NR;
+		r->key.obj_inst.bts_nr = atoi(argv[3]);
+	};
+
+	if (strcmp(argv[4], "any")) {
+		r->flags |= OML_RTF_TRX_NR;
+		r->key.obj_inst.trx_nr = atoi(argv[4]);
+	};
+
+	if (strcmp(argv[5], "any")) {
+		r->flags |= OML_RTF_TS_NR;
+		r->key.obj_inst.ts_nr = atoi(argv[5]);
+	};
+
+	if (!strcmp(argv[0], "add"))
+		rc = oml_route_add(g_inst, r, NULL);
+	else
+		rc = oml_route_del(g_inst, r);
+
+	if (rc < 0) {
+		vty_out(vty, "Error %sing route: %d%s",
+			!strcmp(argv[0], "add") ? "add" : "delet",
+			rc, VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	return CMD_SUCCESS;
+}
+
+struct oml_routing_inst *oml_route_init(void *ctx, void *priv)
+{
+	g_inst = talloc_zero(ctx, struct oml_routing_inst);
+
+	INIT_LLIST_HEAD(&g_inst->routes);
+
+	g_inst->priv = priv;
+
+	/* FIXME: add separate node, as this is the only way to make settings
+	 * persistent via the node-specific save callback */
+	install_element_ve(&show_oml_routing_cmd);
+	install_element(ENABLE_NODE, &cfg_omlr_route_cmd);
+
+	return g_inst;
+}