Move lu_operation into separate file

Create luop.(c|h) and move lu_operation and corresponding TX
functions there to facilitate re-use in upcoming control interface.

Change-Id: Ic55a45d56b37be2ba43d96f7da2af43b46af9813
Related: OS#1645
diff --git a/src/luop.c b/src/luop.c
new file mode 100644
index 0000000..ecf31b4
--- /dev/null
+++ b/src/luop.c
@@ -0,0 +1,268 @@
+/* OsmoHLR TX/RX lu operations */
+
+/* (C) 2017 sysmocom s.f.m.c. GmbH <info@sysmocom.de>
+ * All Rights Reserved
+ *
+ * Author: Harald Welte <laforge@gnumonks.org>
+ *
+ * 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 Affero 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 <stdbool.h>
+#include <string.h>
+#include <errno.h>
+
+#include <osmocom/core/logging.h>
+#include <osmocom/gsm/gsm48_ie.h>
+#include <osmocom/gsm/gsup.h>
+#include <osmocom/gsm/apn.h>
+
+#include "gsup_server.h"
+#include "gsup_router.h"
+#include "logging.h"
+#include "luop.h"
+
+const struct value_string lu_state_names[] = {
+	{ LU_S_NULL,			"NULL" },
+	{ LU_S_LU_RECEIVED,		"LU RECEIVED" },
+	{ LU_S_CANCEL_SENT,		"CANCEL SENT" },
+	{ LU_S_CANCEL_ACK_RECEIVED,	"CANCEL-ACK RECEIVED" },
+	{ LU_S_ISD_SENT,		"ISD SENT" },
+	{ LU_S_ISD_ACK_RECEIVED,	"ISD-ACK RECEIVED" },
+	{ LU_S_COMPLETE,		"COMPLETE" },
+	{ 0, NULL }
+};
+
+/* Transmit a given GSUP message for the given LU operation */
+static void _luop_tx_gsup(struct lu_operation *luop,
+			  const struct osmo_gsup_message *gsup)
+{
+	struct msgb *msg_out;
+
+	msg_out = msgb_alloc_headroom(1024+16, 16, "GSUP LUOP");
+	osmo_gsup_encode(msg_out, gsup);
+
+	osmo_gsup_addr_send(luop->gsup_server, luop->peer,
+			    talloc_total_size(luop->peer),
+			    msg_out);
+}
+
+static inline void fill_gsup_msg(struct osmo_gsup_message *out,
+				 const struct lu_operation *lu,
+				 enum osmo_gsup_message_type mt)
+{
+	memset(out, 0, sizeof(struct osmo_gsup_message));
+	if (lu)
+		osmo_strlcpy(out->imsi, lu->subscr.imsi,
+			     GSM23003_IMSI_MAX_DIGITS + 1);
+	out->message_type = mt;
+}
+
+/* timer call-back in case LU operation doesn't receive an response */
+static void lu_op_timer_cb(void *data)
+{
+	struct lu_operation *luop = data;
+
+	DEBUGP(DMAIN, "LU OP timer expired in state %s\n",
+		get_value_string(lu_state_names, luop->state));
+
+	switch (luop->state) {
+	case LU_S_CANCEL_SENT:
+		break;
+	case LU_S_ISD_SENT:
+		break;
+	default:
+		break;
+	}
+
+	lu_op_tx_error(luop, GMM_CAUSE_NET_FAIL);
+}
+
+bool lu_op_fill_subscr(struct lu_operation *luop, struct db_context *dbc,
+		       const char *imsi)
+{
+	struct hlr_subscriber *subscr = &luop->subscr;
+
+	if (db_subscr_get(dbc, imsi, subscr) < 0)
+		return false;
+
+	return true;
+}
+
+struct lu_operation *lu_op_alloc(struct osmo_gsup_server *srv)
+{
+	struct lu_operation *luop;
+
+	luop = talloc_zero(srv, struct lu_operation);
+	OSMO_ASSERT(luop);
+	luop->gsup_server = srv;
+	luop->timer.cb = lu_op_timer_cb;
+	luop->timer.data = luop;
+
+	return luop;
+}
+
+struct lu_operation *lu_op_alloc_conn(struct osmo_gsup_conn *conn)
+{
+	uint8_t *peer_addr;
+	struct lu_operation *luop = lu_op_alloc(conn->server);
+	int rc = osmo_gsup_conn_ccm_get(conn, &peer_addr, IPAC_IDTAG_SERNR);
+	if (rc < 0)
+		return NULL;
+
+	luop->peer = talloc_memdup(luop, peer_addr, rc);
+
+	return luop;
+}
+
+/* FIXME: this doesn't seem to work at all */
+struct lu_operation *lu_op_by_imsi(const char *imsi,
+				   const struct llist_head *lst)
+{
+	struct lu_operation *luop;
+
+	llist_for_each_entry(luop, lst, list) {
+		if (!strcmp(imsi, luop->subscr.imsi))
+			return luop;
+	}
+	return NULL;
+}
+
+void lu_op_statechg(struct lu_operation *luop, enum lu_state new_state)
+{
+	enum lu_state old_state = luop->state;
+
+	DEBUGP(DMAIN, "LU OP state change: %s -> ",
+		get_value_string(lu_state_names, old_state));
+	DEBUGPC(DMAIN, "%s\n",
+		get_value_string(lu_state_names, new_state));
+
+	luop->state = new_state;
+}
+
+/* Send a msgb to a given address using routing */
+int osmo_gsup_addr_send(struct osmo_gsup_server *gs,
+			const uint8_t *addr, size_t addrlen,
+			struct msgb *msg)
+{
+	struct osmo_gsup_conn *conn;
+
+	conn = gsup_route_find(gs, addr, addrlen);
+	if (!conn) {
+		DEBUGP(DMAIN, "Cannot find route for addr %s\n", addr);
+		msgb_free(msg);
+		return -ENODEV;
+	}
+
+	return osmo_gsup_conn_send(conn, msg);
+}
+
+/*! Transmit UPD_LOC_ERROR and destroy lu_operation */
+void lu_op_tx_error(struct lu_operation *luop, enum gsm48_gmm_cause cause)
+{
+	struct osmo_gsup_message gsup;
+
+	DEBUGP(DMAIN, "%s: LU OP Tx Error (cause %s)\n",
+	       luop->subscr.imsi, get_value_string(gsm48_gmm_cause_names,
+						   cause));
+
+	fill_gsup_msg(&gsup, luop, OSMO_GSUP_MSGT_UPDATE_LOCATION_ERROR);
+	gsup.cause = cause;
+
+	_luop_tx_gsup(luop, &gsup);
+
+	llist_del(&luop->list);
+	talloc_free(luop);
+}
+
+/*! Transmit UPD_LOC_RESULT and destroy lu_operation */
+void lu_op_tx_ack(struct lu_operation *luop)
+{
+	struct osmo_gsup_message gsup;
+
+	fill_gsup_msg(&gsup, luop, OSMO_GSUP_MSGT_UPDATE_LOCATION_RESULT);
+	//FIXME gsup.hlr_enc;
+
+	_luop_tx_gsup(luop, &gsup);
+
+	llist_del(&luop->list);
+	talloc_free(luop);
+}
+
+/*! Send Cancel Location to old VLR/SGSN */
+void lu_op_tx_cancel_old(struct lu_operation *luop)
+{
+	struct osmo_gsup_message gsup;
+
+	OSMO_ASSERT(luop->state == LU_S_LU_RECEIVED);
+
+	fill_gsup_msg(&gsup, NULL, OSMO_GSUP_MSGT_LOCATION_CANCEL_REQUEST);
+	//gsup.cause = FIXME;
+	//gsup.cancel_type = FIXME;
+
+	_luop_tx_gsup(luop, &gsup);
+
+	lu_op_statechg(luop, LU_S_CANCEL_SENT);
+	osmo_timer_schedule(&luop->timer, CANCEL_TIMEOUT_SECS, 0);
+}
+
+/*! Transmit Insert Subscriber Data to new VLR/SGSN */
+void lu_op_tx_insert_subscr_data(struct lu_operation *luop)
+{
+	struct osmo_gsup_message gsup;
+	uint8_t apn[APN_MAXLEN];
+	uint8_t msisdn_enc[43]; /* TODO use constant; TS 24.008 10.5.4.7 */
+	int l;
+
+	OSMO_ASSERT(luop->state == LU_S_LU_RECEIVED ||
+		    luop->state == LU_S_CANCEL_ACK_RECEIVED);
+
+	fill_gsup_msg(&gsup, luop, OSMO_GSUP_MSGT_INSERT_DATA_REQUEST);
+
+	l = gsm48_encode_bcd_number(msisdn_enc, sizeof(msisdn_enc), 0,
+				    luop->subscr.msisdn);
+	if (l < 1) {
+		LOGP(DMAIN, LOGL_ERROR,
+		     "%s: Error: cannot encode MSISDN '%s'\n",
+		     luop->subscr.imsi, luop->subscr.msisdn);
+		lu_op_tx_error(luop, GMM_CAUSE_PROTO_ERR_UNSPEC);
+		return;
+	}
+	gsup.msisdn_enc = msisdn_enc;
+	gsup.msisdn_enc_len = l;
+
+	/* FIXME: deal with encoding the following data */
+	gsup.hlr_enc;
+
+	if (luop->is_ps) {
+		/* FIXME: PDP infos - use more fine-grained access control
+		   instead of wildcard APN */
+		l = osmo_apn_from_str(apn, sizeof(apn), "*");
+		if (l > 0) {
+			gsup.pdp_infos[0].apn_enc = apn;
+			gsup.pdp_infos[0].apn_enc_len = l;
+			gsup.pdp_infos[0].have_info = 1;
+			gsup.num_pdp_infos = 1;
+			/* FIXME: use real value: */
+			gsup.pdp_infos[0].context_id = 1;
+		}
+	}
+
+	/* Send ISD to new VLR/SGSN */
+	_luop_tx_gsup(luop, &gsup);
+
+	lu_op_statechg(luop, LU_S_ISD_SENT);
+	osmo_timer_schedule(&luop->timer, ISD_TIMEOUT_SECS, 0);
+}