Initial version of remsim-server

Change-Id: I1caadc528d5e61a4129c32c53283250cd37f3a3c
diff --git a/.gitignore b/.gitignore
index d543602..2ec5f9f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -33,3 +33,4 @@
 src/remsim-bankd
 src/remsim-client
 src/simtrace2-remsim-client
+src/server/remsim-server
diff --git a/configure.ac b/configure.ac
index 2c30dfb..7a07f6b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -41,6 +41,8 @@
 PKG_CHECK_MODULES(OSMOSIM, libosmosim)
 PKG_CHECK_MODULES(PCSC, libpcsclite)
 PKG_CHECK_MODULES(USB, libusb-1.0)
+PKG_CHECK_MODULES(ULFIUS, libulfius)
+PKG_CHECK_MODULES(JANSSON, jansson)
 
 AC_CONFIG_MACRO_DIR([m4])
 
@@ -87,6 +89,7 @@
 	Makefile
 	src/Makefile
 	src/rspro/Makefile
+	src/server/Makefile
 	include/Makefile
 	include/osmocom/Makefile
 	include/osmocom/rspro/Makefile
diff --git a/src/Makefile.am b/src/Makefile.am
index a44906b..f8aebfe 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,4 +1,4 @@
-SUBDIRS = rspro
+SUBDIRS = rspro server
 
 AM_CFLAGS = -Wall -I$(top_srcdir)/include -I$(top_builddir)/include \
 	    $(OSMOCORE_CFLAGS) $(OSMOGSM_CFLAGS) $(OSMOABIS_CFLAGS) \
diff --git a/src/rspro_util.c b/src/rspro_util.c
index ed0678e..2f2e2d1 100644
--- a/src/rspro_util.c
+++ b/src/rspro_util.c
@@ -93,8 +93,10 @@
 
 void string_fromOCTET_STRING(char *out, size_t out_size, const OCTET_STRING_t *in)
 {
-	if (!in)
+	if (!in) {
 		out[0] = '\0';
+		return;
+	}
 	memcpy(out, in->buf, out_size < in->size ? out_size : in->size);
 	if (in->size < out_size)
 		out[in->size] = '\0';
@@ -155,6 +157,19 @@
 	return pdu;
 }
 
+RsproPDU_t *rspro_gen_ConnectBankRes(const struct app_comp_id *a_cid, e_ResultCode res)
+{
+	RsproPDU_t *pdu = CALLOC(1, sizeof(*pdu));
+	if (!pdu)
+		return NULL;
+	pdu->version = 2;
+	pdu->msg.present = RsproPDUchoice_PR_connectBankRes;
+	fill_comp_id(&pdu->msg.choice.connectBankRes.identity, a_cid);
+	pdu->msg.choice.connectBankRes.result = res;
+
+	return pdu;
+}
+
 RsproPDU_t *rspro_gen_ConnectClientReq(const struct app_comp_id *a_cid, const ClientSlot_t *client)
 {
 	RsproPDU_t *pdu = CALLOC(1, sizeof(*pdu));
diff --git a/src/rspro_util.h b/src/rspro_util.h
index 26b3883..945d4f7 100644
--- a/src/rspro_util.h
+++ b/src/rspro_util.h
@@ -22,6 +22,7 @@
 RsproPDU_t *rspro_dec_msg(struct msgb *msg);
 RsproPDU_t *rspro_gen_ConnectBankReq(const struct app_comp_id *a_cid,
 					uint16_t bank_id, uint16_t num_slots);
+RsproPDU_t *rspro_gen_ConnectBankRes(const struct app_comp_id *a_cid, e_ResultCode res);
 RsproPDU_t *rspro_gen_ConnectClientReq(const struct app_comp_id *a_cid, const ClientSlot_t *client);
 RsproPDU_t *rspro_gen_ConnectClientRes(const struct app_comp_id *a_cid, e_ResultCode res);
 RsproPDU_t *rspro_gen_CreateMappingReq(const ClientSlot_t *client, const BankSlot_t *bank);
diff --git a/src/server/Makefile.am b/src/server/Makefile.am
new file mode 100644
index 0000000..ce7843b
--- /dev/null
+++ b/src/server/Makefile.am
@@ -0,0 +1,14 @@
+
+AM_CFLAGS = -Wall -I$(top_srcdir)/include -I$(top_builddir)/include -I$(top_srcdir)/src \
+	    -I$(top_srcdir)/include/osmocom/rspro \
+	    $(OSMOCORE_CFLAGS) $(OSMOGSM_CFLAGS) $(OSMOABIS_CFLAGS) \
+	    $(ULFIUS_CFLAGS) $(JANSSON_CFLAGS)
+
+noinst_HEADERS = rspro_server.h rest_api.h
+
+bin_PROGRAMS = remsim-server
+
+remsim_server_SOURCES = remsim_server.c rspro_server.c rest_api.c ../rspro_util.c ../slotmap.c ../debug.c
+remsim_server_LDADD = $(OSMOCORE_LIBS) $(OSMOGSM_LIBS) $(OSMOABIS_LIBS) \
+		      $(ULFIUS_LIBS) $(JANSSON_LIBS) \
+		      ../libosmo-rspro.la
diff --git a/src/server/remsim_server.c b/src/server/remsim_server.c
new file mode 100644
index 0000000..29ac582
--- /dev/null
+++ b/src/server/remsim_server.c
@@ -0,0 +1,67 @@
+#include <unistd.h>
+
+#include <sys/eventfd.h>
+
+#include <osmocom/core/utils.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/application.h>
+#include <osmocom/core/select.h>
+
+#include "debug.h"
+#include "slotmap.h"
+#include "rest_api.h"
+#include "rspro_server.h"
+
+struct rspro_server *g_rps;
+void *g_tall_ctx;
+struct osmo_fd g_event_ofd;
+
+int main(int argc, char **argv)
+{
+	int rc;
+
+	g_tall_ctx = talloc_named_const(NULL, 0, "global");
+
+	osmo_init_logging2(g_tall_ctx, &log_info);
+
+	g_rps = rspro_server_create(g_tall_ctx, "0.0.0.0", 9998);
+	if (!g_rps)
+		exit(1);
+	g_rps->slotmaps = slotmap_init(g_rps);
+	if (!g_rps->slotmaps)
+		goto out_rspro;
+
+	g_rps->comp_id.type = ComponentType_remsimServer;
+	OSMO_STRLCPY_ARRAY(g_rps->comp_id.name, "fixme-name");
+	OSMO_STRLCPY_ARRAY(g_rps->comp_id.software, "remsim-server");
+	OSMO_STRLCPY_ARRAY(g_rps->comp_id.sw_version, PACKAGE_VERSION);
+	/* FIXME: other members of app_comp_id */
+
+	rc = eventfd(0, 0);
+	if (rc < 0)
+		goto out_rps;
+	osmo_fd_setup(&g_event_ofd, rc, BSC_FD_READ, event_fd_cb, g_rps, 0);
+	osmo_fd_register(&g_event_ofd);
+
+	rc = rest_api_init(9997);
+	if (rc < 0)
+		goto out_eventfd;
+
+	while (1) {
+		osmo_select_main(0);
+	}
+
+	rest_api_fini();
+
+	exit(0);
+
+out_eventfd:
+	close(g_event_ofd.fd);
+out_rps:
+	talloc_free(g_rps->slotmaps);
+	talloc_free(g_rps);
+out_rspro:
+	rspro_server_destroy(g_rps);
+
+	exit(1);
+}
diff --git a/src/server/rest_api.c b/src/server/rest_api.c
new file mode 100644
index 0000000..a1c5718
--- /dev/null
+++ b/src/server/rest_api.c
@@ -0,0 +1,486 @@
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+
+#include <jansson.h>
+#include <ulfius.h>
+
+#include <osmocom/core/utils.h>
+#include <osmocom/core/linuxlist.h>
+
+#define PREFIX	"/api/backend/v1"
+
+#include "debug.h"
+#include "rest_api.h"
+#include "slotmap.h"
+#include "rspro_server.h"
+
+static json_t *comp_id2json(const struct app_comp_id *comp_id)
+{
+	json_t *ret = json_object();
+
+	static const char *type_names[] = {
+		[ComponentType_remsimClient] = "remsimClient",
+		[ComponentType_remsimServer] = "remsimServer",
+		[ComponentType_remsimBankd] = "remsimBankd"
+	};
+
+	json_object_set_new(ret, "type_", json_string(type_names[comp_id->type]));
+	json_object_set_new(ret, "name", json_string(comp_id->name));
+	json_object_set_new(ret, "software", json_string(comp_id->software));
+	json_object_set_new(ret, "swVersion", json_string(comp_id->sw_version));
+	if (strlen(comp_id->hw_manufacturer))
+		json_object_set_new(ret, "hwManufacturer", json_string(comp_id->hw_manufacturer));
+	if (strlen(comp_id->hw_model))
+		json_object_set_new(ret, "hwModel", json_string(comp_id->hw_model));
+	if (strlen(comp_id->hw_serial_nr))
+		json_object_set_new(ret, "hwSerialNr", json_string(comp_id->hw_serial_nr));
+	if (strlen(comp_id->hw_version))
+		json_object_set_new(ret, "hwVersion", json_string(comp_id->hw_version));
+	if (strlen(comp_id->fw_version))
+		json_object_set_new(ret, "fwVersion", json_string(comp_id->fw_version));
+
+	return ret;
+}
+
+static json_t *client2json(const struct rspro_client_conn *conn)
+{
+	json_t *ret = json_object();
+
+	json_object_set_new(ret, "peer", json_string(conn->fi->id));
+	json_object_set_new(ret, "state", json_string(osmo_fsm_inst_state_name(conn->fi)));
+	/* FIXME: only in the right state */
+	json_object_set_new(ret, "component_id", comp_id2json(&conn->comp_id));
+
+	return ret;
+}
+
+static json_t *bank2json(const struct rspro_client_conn *conn)
+{
+	json_t *ret = client2json(conn);
+	json_object_set_new(ret, "bankId", json_integer(conn->bank.bank_id));
+	json_object_set_new(ret, "numberOfSlots", json_integer(conn->bank.num_slots));
+	return ret;
+}
+
+static json_t *bank_slot2json(const struct bank_slot *bslot)
+{
+	json_t *ret = json_object();
+	json_object_set_new(ret, "bankId", json_integer(bslot->bank_id));
+	json_object_set_new(ret, "slotNr", json_integer(bslot->slot_nr));
+	return ret;
+}
+static int json2bank_slot(struct bank_slot *bslot, json_t *in)
+{
+	json_t *jbank_id, *jslot_nr;
+
+	if (!json_is_object(in))
+		return -EINVAL;
+	jbank_id = json_object_get(in, "bankId");
+	if (!jbank_id || !json_is_integer(jbank_id))
+		return -EINVAL;
+	jslot_nr = json_object_get(in, "slotNr");
+	if (!jslot_nr || !json_is_integer(jslot_nr))
+		return -EINVAL;
+	bslot->bank_id = json_integer_value(jbank_id);
+	bslot->slot_nr = json_integer_value(jslot_nr);
+	return 0;
+}
+
+static json_t *client_slot2json(const struct client_slot *bslot)
+{
+	json_t *ret = json_object();
+	json_object_set_new(ret, "clientId", json_integer(bslot->client_id));
+	json_object_set_new(ret, "slotNr", json_integer(bslot->slot_nr));
+	return ret;
+}
+static int json2client_slot(struct client_slot *cslot, json_t *in)
+{
+	json_t *jclient_id, *jslot_nr;
+
+	if (!json_is_object(in))
+		return -EINVAL;
+	jclient_id = json_object_get(in, "clientId");
+	if (!jclient_id || !json_is_integer(jclient_id))
+		return -EINVAL;
+	jslot_nr = json_object_get(in, "slotNr");
+	if (!jslot_nr || !json_is_integer(jslot_nr))
+		return -EINVAL;
+	cslot->client_id = json_integer_value(jclient_id);
+	cslot->slot_nr = json_integer_value(jslot_nr);
+	return 0;
+}
+
+static json_t *slotmap2json(const struct slot_mapping *slotmap)
+{
+	json_t *ret = json_object();
+	json_object_set_new(ret, "bank", bank_slot2json(&slotmap->bank));
+	json_object_set_new(ret, "client", client_slot2json(&slotmap->client));
+	json_object_set_new(ret, "state", json_string(slotmap_state_name(slotmap->state)));
+	return ret;
+}
+static int json2slotmap(struct slot_mapping *out, json_t *in)
+{
+	json_t *jbank, *jclient;
+	int rc;
+
+	if (!json_is_object(in))
+		return -EINVAL;
+	jbank = json_object_get(in, "bank");
+	if (!jbank || !json_is_object(jbank))
+		return -EINVAL;
+	jclient = json_object_get(in, "client");
+	if (!jclient || !json_is_object(jclient))
+		return -EINVAL;
+
+	rc = json2bank_slot(&out->bank, jbank);
+	if (rc < 0)
+		return rc;
+	return json2client_slot(&out->client, jclient);
+}
+
+
+extern struct rspro_server *g_rps;
+
+static int api_cb_rest_ctr_get(const struct _u_request *req, struct _u_response *resp, void *user_data)
+{
+	return U_CALLBACK_CONTINUE;
+}
+
+static int api_cb_banks_get(const struct _u_request *req, struct _u_response *resp, void *user_data)
+{
+	struct rspro_client_conn *conn;
+	json_t *json_body = json_object();
+	json_t *json_banks = json_array();
+
+	pthread_rwlock_rdlock(&g_rps->rwlock);
+	llist_for_each_entry(conn, &g_rps->banks, list) {
+		json_array_append_new(json_banks, bank2json(conn));
+	}
+	pthread_rwlock_unlock(&g_rps->rwlock);
+
+	json_object_set_new(json_body, "banks", json_banks);
+	ulfius_set_json_body_response(resp, 200, json_body);
+	json_decref(json_body);
+
+	return U_CALLBACK_COMPLETE;
+}
+
+static int api_cb_bank_get(const struct _u_request *req, struct _u_response *resp, void *user_data)
+{
+	const char *bank_id_str = u_map_get(req->map_url, "bank_id");
+	struct rspro_client_conn *conn;
+	json_t *json_body = NULL;
+	unsigned long bank_id;
+	int status;
+
+	if (!bank_id_str) {
+		status = 400;
+		goto out_err;
+	}
+
+	bank_id = strtoul(bank_id_str, NULL, 10);
+	if (bank_id > 0xffff) {
+		status = 400;
+		goto out_err;
+	}
+
+	pthread_rwlock_rdlock(&g_rps->rwlock);
+	llist_for_each_entry(conn, &g_rps->banks, list) {
+		if (conn->bank.bank_id == bank_id) {
+			json_body = bank2json(conn);
+			break;
+		}
+	}
+	pthread_rwlock_unlock(&g_rps->rwlock);
+
+	if (json_body) {
+		ulfius_set_json_body_response(resp, 200, json_body);
+		json_decref(json_body);
+	} else {
+		ulfius_set_json_body_response(resp, 404, json_body);
+	}
+
+	return U_CALLBACK_COMPLETE;
+
+out_err:
+	ulfius_set_empty_body_response(resp, status);
+	return U_CALLBACK_COMPLETE;
+}
+
+
+static int api_cb_clients_get(const struct _u_request *req, struct _u_response *resp, void *user_data)
+{
+	struct rspro_client_conn *conn;
+	json_t *json_body = json_object();
+	json_t *json_clients = json_array();
+
+	pthread_rwlock_rdlock(&g_rps->rwlock);
+	llist_for_each_entry(conn, &g_rps->clients, list) {
+		json_array_append_new(json_clients, client2json(conn));
+	}
+	pthread_rwlock_unlock(&g_rps->rwlock);
+
+	json_object_set_new(json_body, "clients", json_clients);
+	ulfius_set_json_body_response(resp, 200, json_body);
+	json_decref(json_body);
+
+	return U_CALLBACK_COMPLETE;
+}
+
+static int api_cb_client_get(const struct _u_request *req, struct _u_response *resp, void *user_data)
+{
+	const char *client_id_str = u_map_get(req->map_url, "client_id");
+	struct rspro_client_conn *conn;
+	json_t *json_body = NULL;
+	unsigned long client_id;
+	int status;
+
+	if (!client_id_str) {
+		status = 400;
+		goto out_err;
+	}
+
+	client_id = strtoul(client_id_str, NULL, 10);
+	if (client_id > 0xffff) {
+		status = 400;
+		goto out_err;
+	}
+
+	pthread_rwlock_rdlock(&g_rps->rwlock);
+	llist_for_each_entry(conn, &g_rps->clients, list) {
+		if (conn->bank.bank_id == client_id) { /* FIXME */
+			json_body = client2json(conn);
+			break;
+		}
+	}
+	pthread_rwlock_unlock(&g_rps->rwlock);
+
+	if (json_body) {
+		ulfius_set_json_body_response(resp, 200, json_body);
+		json_decref(json_body);
+	} else {
+		ulfius_set_json_body_response(resp, 404, json_body);
+	}
+
+	return U_CALLBACK_COMPLETE;
+
+out_err:
+	ulfius_set_empty_body_response(resp, status);
+	return U_CALLBACK_COMPLETE;
+}
+
+static int api_cb_slotmaps_get(const struct _u_request *req, struct _u_response *resp, void *user_data)
+{
+	struct slot_mapping *map;
+	json_t *json_body = json_object();
+	json_t *json_maps = json_array();
+
+	slotmaps_rdlock(g_rps->slotmaps);
+	llist_for_each_entry(map, &g_rps->slotmaps->mappings, list) {
+		json_array_append_new(json_maps, slotmap2json(map));
+	}
+	slotmaps_unlock(g_rps->slotmaps);
+
+	json_object_set_new(json_body, "slotmaps", json_maps);
+	ulfius_set_json_body_response(resp, 200, json_body);
+	json_decref(json_body);
+
+	return U_CALLBACK_COMPLETE;
+}
+
+extern struct osmo_fd g_event_ofd;
+/* trigger our main thread select() loop */
+static void trigger_main_thread_via_eventfd(void)
+{
+	uint64_t one = 1;
+	int rc;
+
+	rc = write(g_event_ofd.fd, &one, sizeof(one));
+	if (rc < 8)
+		fprintf(stderr, "Error writing to eventfd(): %d\n", rc);
+}
+
+static int api_cb_slotmaps_post(const struct _u_request *req, struct _u_response *resp, void *user_data)
+{
+	struct rspro_server *srv = g_rps;
+	struct slot_mapping slotmap, *map;
+	struct rspro_client_conn *conn;
+	json_error_t json_err;
+	json_t *json_req;
+	int rc;
+
+	json_req = ulfius_get_json_body_request(req, &json_err);
+	if (!json_req) {
+		fprintf(stderr, "REST: No JSON Body\n");
+		goto err;
+	}
+
+	rc = json2slotmap(&slotmap, json_req);
+	if (rc < 0)
+		goto err;
+	map = slotmap_add(g_rps->slotmaps, &slotmap.bank, &slotmap.client);
+	if (!map) {
+		fprintf(stderr, "REST: Cannot add slotmap\n");
+		goto err;
+	}
+	slotmap_state_change(map, SLMAP_S_NEW, NULL);
+
+	/* check if any already-connected bankd matches this new map. If yes, associate it */
+	pthread_rwlock_rdlock(&srv->rwlock);
+	llist_for_each_entry(conn, &srv->banks, list) {
+		if (conn->bank.bank_id == slotmap.bank.bank_id) {
+			slotmap_state_change(map, SLMAP_S_NEW, &conn->bank.maps_new);
+			/* FIXME: Notify the conn FSM about some new maps being available */
+			trigger_main_thread_via_eventfd();
+			break;
+		}
+	}
+	pthread_rwlock_unlock(&srv->rwlock);
+
+
+	ulfius_set_empty_body_response(resp, 201);
+
+	return U_CALLBACK_COMPLETE;
+err:
+	ulfius_set_empty_body_response(resp, 400);
+	return U_CALLBACK_COMPLETE;
+}
+
+/* caller is holding a write lock on slotmaps->rwlock */
+static void _slotmap_mark_deleted(struct slot_mapping *map)
+{
+	struct rspro_client_conn *conn = bankd_conn_by_id(g_rps, map->bank.bank_id);
+
+	/* delete map from global list to ensure it's not found by further lookups,
+	 * particularly in case somebody wants to create a new map for the same bank/slot */
+	llist_del(&map->list);
+	/* safely initialize list head to avoid trouble when del_slotmap() does another llist_del() */
+	INIT_LLIST_HEAD(&map->list);
+
+	switch (map->state) {
+	case SLMAP_S_NEW:
+		/* new map, not yet sent to bank: we can remove it immediately */
+		/* delete from bank list (if any) */
+		llist_del(&map->bank_list);
+		/* safely initialize list head to avoid trouble when del_slotmap() does another llist_del() */
+		INIT_LLIST_HEAD(&map->bank_list);
+		_slotmap_del(map->maps, map);
+		break;
+	case SLMAP_S_UNACKNOWLEDGED:
+		/* map has been sent to bank already, but wasn't acknowledged yet */
+		/* FIXME: what to do now? If we keep it unchanged, it will not be deleted.  If we
+		 * move it to DELETE_REQ, */
+		break;
+	case SLMAP_S_ACTIVE:
+		/* map is fully active. Need to move it to DELETE_REQ state + trigger rspro thread,
+		 * so the deletion can propagate to the bankd */
+		_slotmap_state_change(map, SLMAP_S_DELETE_REQ, &conn->bank.maps_delreq);
+		trigger_main_thread_via_eventfd();
+		break;
+	case SLMAP_S_DELETE_REQ:
+		/* REST had already requested deletion, but RSPRO thread hasn't issued the delete
+		 * command to the bankd yet: Do nothing */
+		break;
+	case SLMAP_S_DELETING:
+		/* we had already requested deletion of this map previously: Do nothing */
+		break;
+	default:
+		OSMO_ASSERT(0);
+	}
+}
+
+static int api_cb_slotmaps_del(const struct _u_request *req, struct _u_response *resp, void *user_data)
+{
+	const char *slotmap_id_str = u_map_get(req->map_url, "slotmap_id");
+	struct slot_mapping *map;
+	int status = 404;
+	unsigned long map_id;
+
+	if (!slotmap_id_str) {
+		status = 400;
+		goto err;
+	}
+	map_id = strtoul(slotmap_id_str, NULL, 10);
+	if (map_id < 0) {
+		status = 400;
+		goto err;
+	}
+
+	slotmaps_wrlock(g_rps->slotmaps);
+	llist_for_each_entry(map, &g_rps->slotmaps->mappings, list) {
+		if (slotmap_get_id(map) == map_id) {
+			_slotmap_mark_deleted(map);
+			status = 200;
+			break;
+		}
+	}
+	slotmaps_unlock(g_rps->slotmaps);
+	trigger_main_thread_via_eventfd();
+
+
+	ulfius_set_empty_body_response(resp, status);
+	return U_CALLBACK_COMPLETE;
+err:
+	ulfius_set_empty_body_response(resp, status);
+	return U_CALLBACK_COMPLETE;
+}
+
+static int api_cb_global_reset_post(const struct _u_request *req, struct _u_response *resp, void *user_data)
+{
+	struct slot_mapping *map, *map2;
+
+	LOGP(DMAIN, LOGL_NOTICE, "Global RESET from REST API\n");
+
+	/* mark all slot mappings as deleted */
+	slotmaps_wrlock(g_rps->slotmaps);
+	llist_for_each_entry_safe(map, map2, &g_rps->slotmaps->mappings, list) {
+		_slotmap_mark_deleted(map);
+	}
+	slotmaps_unlock(g_rps->slotmaps);
+	trigger_main_thread_via_eventfd();
+
+	ulfius_set_empty_body_response(resp, 200);
+	return U_CALLBACK_COMPLETE;
+}
+
+static const struct _u_endpoint api_endpoints[] = {
+	/* get the current restart counter */
+	{ "GET",  PREFIX, "/restart-counter", 0, &api_cb_rest_ctr_get, NULL },
+	/* get a list of SIM banks */
+	{ "GET",  PREFIX, "/banks", 0, &api_cb_banks_get, NULL },
+	{ "GET",  PREFIX, "/banks/:bank_id", 0, &api_cb_bank_get, NULL },
+	/* get a list of SIM clients */
+	{ "GET",  PREFIX, "/clients", 0, &api_cb_clients_get, NULL },
+	{ "GET",  PREFIX, "/clients/:client_id", 0, &api_cb_client_get, NULL },
+	/* get a list of mappings */
+	{ "GET",  PREFIX, "/slotmaps", 0, &api_cb_slotmaps_get, NULL },
+	{ "POST",  PREFIX, "/slotmaps", 0, &api_cb_slotmaps_post, NULL },
+	{ "DELETE",  PREFIX, "/slotmaps/:slotmap_id", 0, &api_cb_slotmaps_del, NULL },
+	{ "POST",  PREFIX, "/global-reset", 0, &api_cb_global_reset_post, NULL },
+};
+
+static struct _u_instance g_instance;
+
+int rest_api_init(uint16_t port)
+{
+	int i;
+
+	if (ulfius_init_instance(&g_instance, port, NULL, NULL) != U_OK)
+		return -1;
+
+	for (i = 0; i < ARRAY_SIZE(api_endpoints); i++)
+		ulfius_add_endpoint(&g_instance, &api_endpoints[i]);
+
+	if (ulfius_start_framework(&g_instance) != U_OK) {
+		fprintf(stderr, "Cannot start REST API on port %u\n", port);
+		return -1;
+	}
+	return 0;
+}
+
+void rest_api_fini(void)
+{
+	ulfius_stop_framework(&g_instance);
+	ulfius_clean_instance(&g_instance);
+}
diff --git a/src/server/rest_api.h b/src/server/rest_api.h
new file mode 100644
index 0000000..87269e8
--- /dev/null
+++ b/src/server/rest_api.h
@@ -0,0 +1,5 @@
+#pragma once
+#include <stdint.h>
+
+int rest_api_init(uint16_t port);
+void rest_api_fini(void);
diff --git a/src/server/rspro_server.c b/src/server/rspro_server.c
new file mode 100644
index 0000000..27a0272
--- /dev/null
+++ b/src/server/rspro_server.c
@@ -0,0 +1,603 @@
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+#include <pthread.h>
+
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/select.h>
+#include <osmocom/core/fsm.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/socket.h>
+#include <osmocom/gsm/protocol/ipaccess.h>
+#include <osmocom/abis/ipa.h>
+
+#include <osmocom/rspro/RsproPDU.h>
+
+#include "debug.h"
+#include "rspro_util.h"
+#include "rspro_server.h"
+
+#define S(x)	(1 << (x))
+
+static void client_slot2rspro(ClientSlot_t *out, const struct client_slot *in)
+{
+	out->clientId = in->client_id;
+	out->slotNr = in->slot_nr;
+}
+
+static void bank_slot2rspro(BankSlot_t *out, const struct bank_slot *in)
+{
+	out->bankId = in->bank_id;
+	out->slotNr = in->slot_nr;
+}
+
+static RsproPDU_t *slotmap2CreateMappingReq(const struct slot_mapping *slotmap)
+{
+	ClientSlot_t clslot;
+	BankSlot_t bslot;
+
+	client_slot2rspro(&clslot, &slotmap->client);
+	bank_slot2rspro(&bslot, &slotmap->bank);
+
+	return rspro_gen_CreateMappingReq(&clslot, &bslot);
+}
+
+static RsproPDU_t *slotmap2RemoveMappingReq(const struct slot_mapping *slotmap)
+{
+	ClientSlot_t clslot;
+	BankSlot_t bslot;
+
+	client_slot2rspro(&clslot, &slotmap->client);
+	bank_slot2rspro(&bslot, &slotmap->bank);
+
+	return rspro_gen_RemoveMappingReq(&clslot, &bslot);
+}
+
+
+static void client_conn_send(struct rspro_client_conn *conn, RsproPDU_t *pdu)
+{
+	struct msgb *msg_tx = rspro_enc_msg(pdu);
+	if (!msg_tx) {
+		ASN_STRUCT_FREE(asn_DEF_RsproPDU, pdu);
+		return;
+	}
+	ipa_prepend_header_ext(msg_tx, IPAC_PROTO_EXT_RSPRO);
+	ipa_msg_push_header(msg_tx, IPAC_PROTO_OSMO);
+	ipa_server_conn_send(conn->peer, msg_tx);
+}
+
+
+/***********************************************************************
+ * per-client connection FSM
+ ***********************************************************************/
+
+static void rspro_client_conn_destroy(struct rspro_client_conn *conn);
+
+enum remsim_server_client_fsm_state {
+	CLNTC_ST_INIT,
+	CLNTC_ST_ESTABLISHED,
+	CLNTC_ST_CONNECTED,
+};
+
+enum remsim_server_client_event {
+	CLNTC_E_TCP_UP,
+	CLNTC_E_CLIENT_CONN,	/* Connect{Client,Bank}Req received */
+	CLNTC_E_BANK_CONN,
+	CLNTC_E_TCP_DOWN,
+	CLNTC_E_CREATE_MAP_RES,	/* CreateMappingRes received */
+	CLNTC_E_REMOVE_MAP_RES,	/* RemoveMappingRes received */
+	CLNTC_E_PUSH,		/* drain maps_new or maps_delreq */
+};
+
+static const struct value_string server_client_event_names[] = {
+	OSMO_VALUE_STRING(CLNTC_E_TCP_UP),
+	OSMO_VALUE_STRING(CLNTC_E_CLIENT_CONN),
+	OSMO_VALUE_STRING(CLNTC_E_BANK_CONN),
+	OSMO_VALUE_STRING(CLNTC_E_TCP_DOWN),
+	OSMO_VALUE_STRING(CLNTC_E_CREATE_MAP_RES),
+	OSMO_VALUE_STRING(CLNTC_E_REMOVE_MAP_RES),
+	OSMO_VALUE_STRING(CLNTC_E_PUSH),
+	{ 0, NULL }
+};
+
+static void clnt_st_init(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+	switch (event) {
+	case CLNTC_E_TCP_UP:
+		osmo_fsm_inst_state_chg(fi, CLNTC_ST_ESTABLISHED, 10, 1);
+		break;
+	default:
+		OSMO_ASSERT(0);
+	}
+}
+
+static void clnt_st_established(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+	struct rspro_client_conn *conn = fi->priv;
+	const RsproPDU_t *pdu = data;
+	const ConnectClientReq_t *cclreq = NULL;
+	const ConnectBankReq_t *cbreq = NULL;
+	RsproPDU_t *resp = NULL;
+
+	switch (event) {
+	case CLNTC_E_CLIENT_CONN:
+		cclreq = &pdu->msg.choice.connectClientReq;
+		/* save the [remote] component identity in 'conn' */
+		rspro_comp_id_retrieve(&conn->comp_id, &cclreq->identity);
+		if (conn->comp_id.type != ComponentType_remsimClient) {
+			LOGPFSM(fi, "ConnectClientReq from identity != Client ?!?\n");
+			osmo_fsm_inst_term(fi, OSMO_FSM_TERM_ERROR, NULL);
+		}
+		/* FIXME: determine client ID */
+		//osmo_fsm_inst_update_id_f(fi, "C%u:%u", conn->bank.bank_id);
+
+		/* reparent us from srv->connections to srv->clients */
+		pthread_rwlock_wrlock(&conn->srv->rwlock);
+		llist_del(&conn->list);
+		llist_add_tail(&conn->list, &conn->srv->clients);
+		pthread_rwlock_unlock(&conn->srv->rwlock);
+
+		osmo_fsm_inst_state_chg(fi, CLNTC_ST_CONNECTED, 0, 0);
+
+		resp = rspro_gen_ConnectClientRes(&conn->srv->comp_id, ResultCode_ok);
+		client_conn_send(conn, resp);
+		break;
+	case CLNTC_E_BANK_CONN:
+		cbreq = &pdu->msg.choice.connectBankReq;
+		/* save the [remote] component identity in 'conn' */
+		rspro_comp_id_retrieve(&conn->comp_id, &cbreq->identity);
+		if (conn->comp_id.type != ComponentType_remsimBankd) {
+			LOGPFSM(fi, "ConnectBankReq from identity != Bank ?!?\n");
+			osmo_fsm_inst_term(fi, OSMO_FSM_TERM_ERROR, NULL);
+		}
+		conn->bank.bank_id = cbreq->bankId;
+		conn->bank.num_slots = cbreq->numberOfSlots;
+		osmo_fsm_inst_update_id_f(fi, "B%u", conn->bank.bank_id);
+
+		/* reparent us from srv->connections to srv->banks */
+		pthread_rwlock_wrlock(&conn->srv->rwlock);
+		llist_del(&conn->list);
+		llist_add_tail(&conn->list, &conn->srv->banks);
+		pthread_rwlock_unlock(&conn->srv->rwlock);
+
+		/* send response to bank first */
+		resp = rspro_gen_ConnectBankRes(&conn->srv->comp_id, ResultCode_ok);
+		client_conn_send(conn, resp);
+
+		/* the state change will associate any pre-existing slotmaps */
+		osmo_fsm_inst_state_chg(fi, CLNTC_ST_CONNECTED, 0, 0);
+
+		osmo_fsm_inst_dispatch(fi, CLNTC_E_PUSH, NULL);
+		break;
+	default:
+		OSMO_ASSERT(0);
+	}
+}
+
+
+static void clnt_st_connected_cl_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
+{
+#if 0
+	struct rspro_client_conn *conn = fi->priv;
+	ClientSlot_t clslot;
+	RsproPDU_t *pdu;
+
+	/* send configuration to this new client */
+	client_slot2rspro(&clslot, FIXME);
+	pdu = rspro_gen_ConfigClientReq(&clslot, bankd_ip, bankd_port);
+	client_conn_send(conn, pdu);
+#endif
+}
+
+static void clnt_st_connected_bk_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
+{
+	struct rspro_client_conn *conn = fi->priv;
+	struct slotmaps *slotmaps = conn->srv->slotmaps;
+	struct slot_mapping *map;
+
+	LOGPFSM(fi, "Associating pre-existing slotmaps (if any)\n");
+	/* Link all known mappings to this new bank */
+	slotmaps_wrlock(slotmaps);
+	llist_for_each_entry(map, &slotmaps->mappings, list) {
+		if (map->bank.bank_id == conn->bank.bank_id)
+			_slotmap_state_change(map, SLMAP_S_NEW, &conn->bank.maps_new);
+	}
+	slotmaps_unlock(slotmaps);
+}
+
+static void clnt_st_connected_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
+{
+	struct rspro_client_conn *conn = fi->priv;
+	switch (conn->comp_id.type) {
+	case ComponentType_remsimClient:
+		clnt_st_connected_cl_onenter(fi, prev_state);
+		break;
+	case ComponentType_remsimBankd:
+		clnt_st_connected_bk_onenter(fi, prev_state);
+		break;
+	default:
+		OSMO_ASSERT(0);
+	}
+}
+
+static void clnt_st_connected(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+	struct rspro_client_conn *conn = fi->priv;
+	struct slotmaps *slotmaps = conn->srv->slotmaps;
+	const struct RsproPDU_t *rx = NULL;
+	struct slot_mapping *map, *map2;
+
+	switch (event) {
+	case CLNTC_E_CREATE_MAP_RES:
+		rx = data;
+		slotmaps_wrlock(slotmaps);
+		/* FIXME: resolve map by pdu->tag */
+		/* as hack use first element of conn->maps_unack */
+		map = llist_first_entry(&conn->bank.maps_unack, struct slot_mapping, bank_list);
+		if (!map) {
+			slotmaps_unlock(slotmaps);
+			LOGPFSM(fi, "CreateMapRes but no unacknowledged map");
+			break;
+		}
+		_slotmap_state_change(map, SLMAP_S_ACTIVE, &conn->bank.maps_active);
+		slotmaps_unlock(slotmaps);
+		break;
+	case CLNTC_E_REMOVE_MAP_RES:
+		rx = data;
+		slotmaps_wrlock(slotmaps);
+		/* FIXME: resolve map by pdu->tag */
+		/* as hack use first element of conn->maps_deleting */
+		map = llist_first_entry(&conn->bank.maps_deleting, struct slot_mapping, bank_list);
+		if (!map) {
+			slotmaps_unlock(slotmaps);
+			LOGPFSM(fi, "RemoveMapRes but no unacknowledged map");
+			break;
+		}
+		slotmaps_unlock(slotmaps);
+		/* slotmap_del() will remove it from both global and bank list */
+		slotmap_del(map->maps, map);
+		break;
+	case CLNTC_E_PUSH:
+		slotmaps_wrlock(slotmaps);
+		/* send any pending create requests */
+		llist_for_each_entry_safe(map, map2, &conn->bank.maps_new, bank_list) {
+			RsproPDU_t *pdu = slotmap2CreateMappingReq(map);
+			client_conn_send(conn, pdu);
+			_slotmap_state_change(map, SLMAP_S_UNACKNOWLEDGED, &conn->bank.maps_unack);
+		}
+		/* send any pending delete requests */
+		llist_for_each_entry_safe(map, map2, &conn->bank.maps_delreq, bank_list) {
+			RsproPDU_t *pdu = slotmap2RemoveMappingReq(map);
+			client_conn_send(conn, pdu);
+			_slotmap_state_change(map, SLMAP_S_DELETING, &conn->bank.maps_deleting);
+		}
+		slotmaps_unlock(slotmaps);
+		break;
+	default:
+		OSMO_ASSERT(0);
+	}
+}
+
+static void clnt_allstate_action(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+	struct rspro_client_conn *conn = fi->priv;
+
+	switch (event) {
+	case CLNTC_E_TCP_DOWN:
+		osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, NULL);
+		break;
+	default:
+		OSMO_ASSERT(0);
+	}
+}
+
+static int server_client_fsm_timer_cb(struct osmo_fsm_inst *fi)
+{
+	struct rspro_client_conn *conn = fi->priv;
+
+	switch (fi->T) {
+	case 1:
+		/* No ClientConnectReq received:disconnect */
+		return 1; /* ask core to terminate FSM */
+	default:
+		OSMO_ASSERT(0);
+	}
+	return 0;
+}
+
+static void server_client_cleanup(struct osmo_fsm_inst *fi, enum osmo_fsm_term_cause cause)
+{
+	struct rspro_client_conn *conn = fi->priv;
+	/* this call will destroy the IPA connection, which will in turn call closed_cb()
+	 * which will try to deliver a E_TCP_DOWN event. Clear conn->fi to avoid that loop */
+	conn->fi = NULL;
+	rspro_client_conn_destroy(conn);
+}
+
+static const struct osmo_fsm_state server_client_fsm_states[] = {
+	[CLNTC_ST_INIT] = {
+		.name = "INIT",
+		.in_event_mask = S(CLNTC_E_TCP_UP),
+		.out_state_mask = S(CLNTC_ST_ESTABLISHED),
+		.action = clnt_st_init,
+	},
+	[CLNTC_ST_ESTABLISHED] = {
+		.name = "ESTABLISHED",
+		.in_event_mask = S(CLNTC_E_CLIENT_CONN) | S(CLNTC_E_BANK_CONN),
+		.out_state_mask = S(CLNTC_ST_CONNECTED),
+		.action = clnt_st_established,
+	},
+	[CLNTC_ST_CONNECTED] = {
+		.name = "CONNECTED",
+		.in_event_mask = S(CLNTC_E_CREATE_MAP_RES) | S(CLNTC_E_REMOVE_MAP_RES) |
+				 S(CLNTC_E_PUSH),
+		.action = clnt_st_connected,
+		.onenter = clnt_st_connected_onenter,
+	},
+};
+
+static struct osmo_fsm remsim_server_client_fsm = {
+	.name = "SERVER_CONN",
+	.states = server_client_fsm_states,
+	.num_states = ARRAY_SIZE(server_client_fsm_states),
+	.allstate_event_mask = S(CLNTC_E_TCP_DOWN),
+	.allstate_action = clnt_allstate_action,
+	.cleanup = server_client_cleanup,
+	.timer_cb = server_client_fsm_timer_cb,
+	.log_subsys = DMAIN,
+	.event_names = server_client_event_names,
+};
+
+struct osmo_fsm_inst *server_client_fsm_alloc(void *ctx, struct rspro_client_conn *conn)
+{
+	//const char *id = osmo_sock_get_name2(conn->peer->ofd.fd);
+	return osmo_fsm_inst_alloc(&remsim_server_client_fsm, ctx, conn, LOGL_DEBUG, NULL);
+}
+
+
+static __attribute__((constructor)) void on_dso_load(void)
+{
+	osmo_fsm_register(&remsim_server_client_fsm);
+}
+
+
+/***********************************************************************
+ * IPA RSPRO Server
+ ***********************************************************************/
+
+struct rspro_client_conn *_bankd_conn_by_id(struct rspro_server *srv, uint16_t bank_id)
+{
+	struct rspro_client_conn *conn;
+	llist_for_each_entry(conn, &srv->banks, list) {
+		if (conn->bank.bank_id == bank_id)
+			return conn;
+	}
+	return NULL;
+}
+struct rspro_client_conn *bankd_conn_by_id(struct rspro_server *srv, uint16_t bank_id)
+{
+	struct rspro_client_conn *conn;
+	pthread_rwlock_rdlock(&srv->rwlock);
+	conn = _bankd_conn_by_id(srv, bank_id);
+	pthread_rwlock_unlock(&srv->rwlock);
+	return conn;
+}
+
+static int handle_rx_rspro(struct rspro_client_conn *conn, const RsproPDU_t *pdu)
+{
+	switch (pdu->msg.present) {
+	case RsproPDUchoice_PR_connectClientReq:
+		osmo_fsm_inst_dispatch(conn->fi, CLNTC_E_CLIENT_CONN, (void *)pdu);
+		break;
+	case RsproPDUchoice_PR_connectBankReq:
+		osmo_fsm_inst_dispatch(conn->fi, CLNTC_E_BANK_CONN, (void *)pdu);
+		break;
+	case RsproPDUchoice_PR_createMappingRes:
+		osmo_fsm_inst_dispatch(conn->fi, CLNTC_E_CREATE_MAP_RES, (void *)pdu);
+		break;
+	case RsproPDUchoice_PR_removeMappingRes:
+		osmo_fsm_inst_dispatch(conn->fi, CLNTC_E_REMOVE_MAP_RES, (void *)pdu);
+		break;
+	default:
+		LOGPFSML(conn->fi, LOGL_ERROR, "Received unknown/unimplemented RSPRO msg_type %d\n",
+			 pdu->msg.present);
+		return -1;
+	}
+	return 0;
+}
+
+/* data was received from one of the client connections to the RSPRO socket */
+static int sock_read_cb(struct ipa_server_conn *peer, struct msgb *msg)
+{
+	struct ipaccess_head *hh = (struct ipaccess_head *) msg->data;
+	struct ipaccess_head_ext *he = (struct ipaccess_head_ext *) msgb_l2(msg);
+	struct rspro_client_conn *conn = peer->data;
+	RsproPDU_t *pdu;
+	int rc;
+
+	if (msgb_length(msg) < sizeof(*hh))
+		goto invalid;
+	msg->l2h = &hh->data[0];
+	if (hh->proto != IPAC_PROTO_OSMO)
+		goto invalid;
+	if (!he || msgb_l2len(msg)< sizeof(*he))
+		goto invalid;
+	msg->l2h = &he->data[0];
+
+	if (he->proto!= IPAC_PROTO_EXT_RSPRO)
+		goto invalid;
+
+	pdu = rspro_dec_msg(msg);
+	if (!pdu)
+		goto invalid;
+
+	rc = handle_rx_rspro(conn, pdu);
+	ASN_STRUCT_FREE(asn_DEF_RsproPDU, pdu);
+	return rc;
+
+invalid:
+	msgb_free(msg);
+	return -1;
+}
+
+static int sock_closed_cb(struct ipa_server_conn *peer)
+{
+	struct rspro_client_conn *conn = peer->data;
+	if (conn->fi)
+		osmo_fsm_inst_dispatch(conn->fi, CLNTC_E_TCP_DOWN, NULL);
+	/* FIXME: who cleans up conn? */
+	/* ipa server code relases 'peer' just after this */
+	return 0;
+}
+
+/* a new TCP connection was accepted on the RSPRO server socket */
+static int accept_cb(struct ipa_server_link *link, int fd)
+{
+	struct rspro_server *srv = link->data;
+	struct rspro_client_conn *conn;
+
+	conn = talloc_zero(srv, struct rspro_client_conn);
+	OSMO_ASSERT(conn);
+
+	conn->srv = srv;
+	/* don't allocate peer under 'conn', as it must survive 'conn' during teardown */
+	conn->peer = ipa_server_conn_create(link, link, fd, sock_read_cb, sock_closed_cb, conn);
+	if (!conn->peer)
+		goto out_err;
+
+	/* don't allocate 'fi' as slave from 'conn', as 'fi' needs to survive 'conn' during
+	 * teardown */
+	conn->fi = server_client_fsm_alloc(srv, conn);
+	if (!conn->fi)
+		goto out_err_conn;
+
+	INIT_LLIST_HEAD(&conn->bank.maps_new);
+	INIT_LLIST_HEAD(&conn->bank.maps_unack);
+	INIT_LLIST_HEAD(&conn->bank.maps_active);
+	INIT_LLIST_HEAD(&conn->bank.maps_delreq);
+	INIT_LLIST_HEAD(&conn->bank.maps_deleting);
+
+	pthread_rwlock_wrlock(&conn->srv->rwlock);
+	llist_add_tail(&conn->list, &srv->connections);
+	pthread_rwlock_unlock(&conn->srv->rwlock);
+
+	osmo_fsm_inst_dispatch(conn->fi, CLNTC_E_TCP_UP, NULL);
+	return 0;
+
+out_err_conn:
+	ipa_server_conn_destroy(conn->peer);
+	/* the above will free 'conn' down the chain */
+	return -1;
+out_err:
+	talloc_free(conn);
+	return -1;
+}
+
+/* call-back if we were triggered by a rest_api thread */
+int event_fd_cb(struct osmo_fd *ofd, unsigned int what)
+{
+	struct rspro_server *srv = ofd->data;
+	struct rspro_client_conn *conn;
+	bool non_empty_new, non_empty_del;
+	uint64_t value;
+	int rc;
+
+	/* read from the socket to "confirm" the event and make it non-readable again */
+	rc = read(ofd->fd, &value, 8);
+	if (rc < 8) {
+		fprintf(stderr, "Error reading eventfd: %d\n", rc);
+		return rc;
+	}
+
+	printf("rspro_server: Event FD arrived, checking for any pending work\n");
+
+	pthread_rwlock_rdlock(&srv->rwlock);
+	llist_for_each_entry(conn, &srv->banks, list) {
+		slotmaps_rdlock(srv->slotmaps);
+		non_empty_new = llist_empty(&conn->bank.maps_new);
+		non_empty_del = llist_empty(&conn->bank.maps_delreq);
+		slotmaps_unlock(srv->slotmaps);
+
+		/* trigger FSM to send any pending new/deleted maps */
+		if (non_empty_new || non_empty_del)
+			osmo_fsm_inst_dispatch(conn->fi, CLNTC_E_PUSH, NULL);
+	}
+	pthread_rwlock_unlock(&srv->rwlock);
+
+	return 0;
+}
+
+/* unlink all slotmaps from any of the lists of this conn->bank.maps_* */
+static void _unlink_all_slotmaps(struct rspro_client_conn *conn)
+{
+	struct slot_mapping *smap, *smap2;
+
+	llist_for_each_entry_safe(smap, smap2, &conn->bank.maps_new, bank_list) {
+		/* unlink from list and keep in state NEW */
+		_slotmap_state_change(smap, SLMAP_S_NEW, NULL);
+	}
+	llist_for_each_entry_safe(smap, smap2, &conn->bank.maps_unack, bank_list) {
+		/* unlink from list and change to state NEW */
+		_slotmap_state_change(smap, SLMAP_S_NEW, NULL);
+	}
+	llist_for_each_entry_safe(smap, smap2, &conn->bank.maps_active, bank_list) {
+		/* unlink from list and change to state NEW */
+		_slotmap_state_change(smap, SLMAP_S_NEW, NULL);
+	}
+	llist_for_each_entry_safe(smap, smap2, &conn->bank.maps_delreq, bank_list) {
+		/* unlink from list and delete */
+		_slotmap_del(smap->maps, smap);
+	}
+	llist_for_each_entry_safe(smap, smap2, &conn->bank.maps_deleting, bank_list) {
+		/* unlink from list and delete */
+		_slotmap_del(smap->maps, smap);
+	}
+}
+
+/* only to be used by the FSM cleanup. */
+static void rspro_client_conn_destroy(struct rspro_client_conn *conn)
+{
+	/* this will internally call closed_cb() which will dispatch a TCP_DOWN event */
+	ipa_server_conn_destroy(conn->peer);
+	conn->peer = NULL;
+
+	/* ensure all slotmaps are unlinked + returned to NEW or deleted */
+	slotmaps_wrlock(conn->srv->slotmaps);
+	_unlink_all_slotmaps(conn);
+	slotmaps_unlock(conn->srv->slotmaps);
+
+	pthread_rwlock_wrlock(&conn->srv->rwlock);
+	llist_del(&conn->list);
+	pthread_rwlock_unlock(&conn->srv->rwlock);
+
+	talloc_free(conn);
+}
+
+
+struct rspro_server *rspro_server_create(void *ctx, const char *host, uint16_t port)
+
+{
+	struct rspro_server *srv = talloc_zero(ctx, struct rspro_server);
+	OSMO_ASSERT(srv);
+
+	pthread_rwlock_init(&srv->rwlock, NULL);
+	pthread_rwlock_wrlock(&srv->rwlock);
+	INIT_LLIST_HEAD(&srv->connections);
+	INIT_LLIST_HEAD(&srv->clients);
+	INIT_LLIST_HEAD(&srv->banks);
+	pthread_rwlock_unlock(&srv->rwlock);
+
+	srv->link = ipa_server_link_create(ctx, NULL, host, port, accept_cb, srv);
+	ipa_server_link_open(srv->link);
+
+	return srv;
+}
+
+void rspro_server_destroy(struct rspro_server *srv)
+{
+	/* FIXME: clear all lists */
+
+	ipa_server_link_destroy(srv->link);
+	srv->link = NULL;
+	talloc_free(srv);
+}
diff --git a/src/server/rspro_server.h b/src/server/rspro_server.h
new file mode 100644
index 0000000..9001192
--- /dev/null
+++ b/src/server/rspro_server.h
@@ -0,0 +1,55 @@
+#pragma once
+#include <pthread.h>
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/select.h>
+#include <osmocom/core/fsm.h>
+#include <osmocom/abis/ipa.h>
+
+#include "rspro_util.h"
+#include "slotmap.h"
+
+struct rspro_server {
+	struct ipa_server_link *link;
+	/* list of rspro_client_conn */
+	struct llist_head connections;
+	struct llist_head clients;
+	struct llist_head banks;
+	/* rwlock protecting any of the lists above */
+	pthread_rwlock_t rwlock;
+
+	struct slotmaps *slotmaps;
+
+	/* our own (server) component identity */
+	struct app_comp_id comp_id;
+};
+
+/* representing a single client connection to an RSPRO server */
+struct rspro_client_conn {
+	/* global list of connections */
+	struct llist_head list;
+	/* back-pointer to rspro_server */
+	struct rspro_server *srv;
+	/* reference to the underlying IPA server connection */
+	struct ipa_server_conn *peer;
+	/* FSM instance for this connection */
+	struct osmo_fsm_inst *fi;
+	/* remote component identity (after it has been received) */
+	struct app_comp_id comp_id;
+
+	struct {
+		struct llist_head maps_new;
+		struct llist_head maps_unack;
+		struct llist_head maps_active;
+		struct llist_head maps_delreq;
+		struct llist_head maps_deleting;
+		uint16_t bank_id;
+		uint16_t num_slots;
+	} bank;
+};
+
+struct rspro_server *rspro_server_create(void *ctx, const char *host, uint16_t port);
+void rspro_server_destroy(struct rspro_server *srv);
+int event_fd_cb(struct osmo_fd *ofd, unsigned int what);
+
+struct rspro_client_conn *_bankd_conn_by_id(struct rspro_server *srv, uint16_t bank_id);
+struct rspro_client_conn *bankd_conn_by_id(struct rspro_server *srv, uint16_t bank_id);