1 files changed, 0 insertions, 687 deletions

diff --git a/src/libmsc/a_iface.c b/src/libmsc/a_iface.c
deleted file mode 100644
index 91a2b6a3e..000000000
--- a/src/libmsc/a_iface.c
+++ /dev/null
@@ -1,687 +0,0 @@
-/* (C) 2017 by sysmocom s.f.m.c. GmbH
- * (C) 2018 by Harald Welte <laforge@gnumonks.org>
- * All Rights Reserved
- *
- * Author: Philipp Maier
- *
- * 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 <osmocom/core/utils.h>
-#include <osmocom/core/msgb.h>
-#include <osmocom/core/logging.h>
-#include <osmocom/sigtran/sccp_helpers.h>
-#include <osmocom/sigtran/sccp_sap.h>
-#include <osmocom/sigtran/osmo_ss7.h>
-#include <osmocom/sigtran/protocol/m3ua.h>
-#include <osmocom/gsm/gsm0808.h>
-#include <osmocom/gsm/protocol/gsm_08_08.h>
-#include <osmocom/gsm/protocol/gsm_04_08.h>
-#include <osmocom/gsm/gsm0808_utils.h>
-#include <osmocom/msc/debug.h>
-#include <osmocom/msc/msc_ifaces.h>
-#include <osmocom/msc/a_iface.h>
-#include <osmocom/msc/a_iface_bssap.h>
-#include <osmocom/msc/transaction.h>
-#include <osmocom/mgcp_client/mgcp_client.h>
-#include <osmocom/core/byteswap.h>
-#include <osmocom/sccp/sccp_types.h>
-#include <osmocom/msc/a_reset.h>
-#include <osmocom/msc/vlr.h>
-#include <osmocom/msc/ran_conn.h>
-
-#include <errno.h>
-
-#define LOGPCONN LOG_RAN_CONN
-
-/* A pointer to the GSM network we work with. By the current paradigm,
- * there can only be one gsm_network per MSC. The pointer is set once
- * when calling a_init() */
-static struct gsm_network *gsm_network = NULL;
-
-/* A struct to track currently active connections. We need that information
- * to handle failure sitautions. In case of a problem, we must know which
- * connections are currently open and which BSC is responsible. We also need
- * the data to perform our connection checks (a_reset). All other logic will
- * look at the connection ids and addresses that are supplied by the
- * primitives */
-struct bsc_conn {
-	struct llist_head list;
-	uint32_t conn_id;			/* Connection identifier */
-	struct bsc_context *bsc;
-};
-
-/* Internal list with connections we currently maintain. This
- * list is of type struct bsc_conn (see above) */
-static LLIST_HEAD(active_connections);
-
-/* Record info of a new active connection in the active connection list */
-static void record_bsc_con(const void *ctx, struct bsc_context *bsc, uint32_t conn_id)
-{
-	struct bsc_conn *conn;
-
-	conn = talloc_zero(ctx, struct bsc_conn);
-	OSMO_ASSERT(conn);
-
-	conn->conn_id = conn_id;
-	conn->bsc = bsc;
-
-	llist_add_tail(&conn->list, &active_connections);
-}
-
-/* Delete info of a closed connection from the active connection list */
-void a_delete_bsc_con(uint32_t conn_id)
-{
-	struct bsc_conn *conn;
-	struct bsc_conn *conn_temp;
-
-	llist_for_each_entry_safe(conn, conn_temp, &active_connections, list) {
-		if (conn->conn_id == conn_id) {
-			LOGP(DBSSAP, LOGL_DEBUG, "(conn%u) Removing A-interface conn\n", conn->conn_id);
-			llist_del(&conn->list);
-			talloc_free(conn);
-		}
-	}
-}
-
-/* Find a specified connection id */
-static struct bsc_conn *find_bsc_con(uint32_t conn_id)
-{
-	struct bsc_conn *conn;
-
-	/* Find the address for the current connection id */
-	llist_for_each_entry(conn, &active_connections, list) {
-		if (conn->conn_id == conn_id) {
-			return conn;
-		}
-	}
-
-	return NULL;
-}
-
-/* Check if a specified connection id has an active SCCP connection */
-static bool check_connection_active(uint32_t conn_id)
-{
-	if (find_bsc_con(conn_id))
-		return true;
-	else
-		return false;
-}
-
-/* Get the context for a specific calling (BSC) address */
-static struct bsc_context *get_bsc_context_by_sccp_addr(const struct osmo_sccp_addr *addr)
-{
-	struct bsc_context *bsc_ctx;
-	struct osmo_ss7_instance *ss7;
-
-	if (!addr)
-		return NULL;
-
-	llist_for_each_entry(bsc_ctx, &gsm_network->a.bscs, list) {
-		if (memcmp(&bsc_ctx->bsc_addr, addr, sizeof(*addr)) == 0)
-			return bsc_ctx;
-	}
-
-	ss7 = osmo_ss7_instance_find(gsm_network->a.cs7_instance);
-	OSMO_ASSERT(ss7);
-	LOGP(DBSSAP, LOGL_NOTICE, "The calling BSC (%s) is unknown to this MSC ...\n",
-	     osmo_sccp_addr_name(ss7, addr));
-	return NULL;
-}
-
-/* wrapper around osmo_sccp_tx_data_msg(): Transmit a fully encoded BSSAP (DTAP or BSSMAP) message */
-static int a_iface_tx_bssap(const struct ran_conn *conn, struct msgb *msg)
-{
-	OSMO_ASSERT(conn);
-	OSMO_ASSERT(conn->a.scu);
-
-	LOGPCONN(conn, LOGL_DEBUG, "N-DATA.req(%s)\n", msgb_hexdump_l3(msg));
-
-	/* some consistency checks to ensure we don't send invalid length */
-	switch (msg->l3h[0]) {
-	case BSSAP_MSG_DTAP:
-		OSMO_ASSERT(msgb_l3len(msg) == msg->l3h[2] + 3);
-		break;
-	case BSSAP_MSG_BSS_MANAGEMENT:
-		OSMO_ASSERT(msgb_l3len(msg) == msg->l3h[1] + 2);
-		break;
-	default:
-		break;
-	}
-
-	return osmo_sccp_tx_data_msg(conn->a.scu, conn->a.conn_id, msg);
-}
-
-/* Send DTAP message via A-interface, take ownership of msg */
-int a_iface_tx_dtap(struct msgb *msg)
-{
-	const struct ran_conn *conn;
-	struct msgb *msg_resp;
-
-	uint8_t link_id = OMSC_LINKID_CB(msg);
-	OSMO_ASSERT(msg);
-	conn = (struct ran_conn *)msg->dst;
-	OSMO_ASSERT(conn);
-
-	LOGPCONN(conn, LOGL_DEBUG, "Passing DTAP message (DLCI=0x%02x) from MSC to BSC\n", link_id);
-
-	msg->l3h = msg->data;
-	msg_resp = gsm0808_create_dtap(msg, link_id);
-
-	/* gsm0808_create_dtap() has copied the data to msg_resp,
-	 * so msg has served its purpose now */
-	msgb_free(msg);
-
-	if (!msg_resp) {
-		LOGPCONN(conn, LOGL_ERROR, "Unable to generate BSSMAP DTAP message!\n");
-		return -EINVAL;
-	}
-
-	/* osmo_sccp_tx_data_msg() takes ownership of msg_resp */
-	return a_iface_tx_bssap(conn, msg_resp);
-}
-
-/* Send Cipher mode command via A-interface */
-int a_iface_tx_cipher_mode(const struct ran_conn *conn,
-			   struct gsm0808_encrypt_info *ei, int include_imeisv)
-{
-	/* TODO generalize for A- and Iu interfaces, don't name after 08.08 */
-	struct msgb *msg_resp;
-	uint8_t crm = 0x01;
-
-	OSMO_ASSERT(conn);
-	LOGPCONN(conn, LOGL_DEBUG, "Tx BSSMAP CIPHER MODE COMMAND to BSC, %u ciphers (%s)",
-		 ei->perm_algo_len, osmo_hexdump_nospc(ei->perm_algo, ei->perm_algo_len));
-	LOGPC(DBSSAP, LOGL_DEBUG, " key %s\n", osmo_hexdump_nospc(ei->key, ei->key_len));
-
-	msg_resp = gsm0808_create_cipher(ei, include_imeisv ? &crm : NULL);
-	return a_iface_tx_bssap(conn, msg_resp);
-}
-
-/* Page a subscriber via A-interface */
-int a_iface_tx_paging(const char *imsi, uint32_t tmsi, uint16_t lac)
-{
-	struct bsc_context *bsc_ctx;
-	struct gsm0808_cell_id_list2 cil;
-	struct msgb *msg;
-	int page_count = 0;
-	struct osmo_ss7_instance *ss7;
-
-	OSMO_ASSERT(imsi);
-
-	cil.id_discr = CELL_IDENT_LAC;
-	cil.id_list[0].lac = lac;
-	cil.id_list_len = 1;
-
-	ss7 = osmo_ss7_instance_find(gsm_network->a.cs7_instance);
-	OSMO_ASSERT(ss7);
-
-	/* Deliver paging request to all known BSCs */
-	llist_for_each_entry(bsc_ctx, &gsm_network->a.bscs, list) {
-		if (a_reset_conn_ready(bsc_ctx->reset_fsm)) {
-			LOGP(DBSSAP, LOGL_DEBUG,
-			     "Tx BSSMAP paging message from MSC %s to BSC %s (imsi=%s, tmsi=0x%08x, lac=%u)\n",
-			     osmo_sccp_addr_name(ss7, &bsc_ctx->msc_addr),
-			     osmo_sccp_addr_name(ss7, &bsc_ctx->bsc_addr), imsi, tmsi, lac);
-			msg = gsm0808_create_paging2(imsi, &tmsi, &cil, NULL);
-			osmo_sccp_tx_unitdata_msg(bsc_ctx->sccp_user,
-						  &bsc_ctx->msc_addr, &bsc_ctx->bsc_addr, msg);
-			page_count++;
-		} else {
-			LOGP(DBSSAP, LOGL_DEBUG,
-			     "Connection down, dropping paging from MSC %s to BSC %s (imsi=%s, tmsi=0x%08x, lac=%u)\n",
-			     osmo_sccp_addr_name(ss7, &bsc_ctx->msc_addr),
-			     osmo_sccp_addr_name(ss7, &bsc_ctx->bsc_addr), imsi, tmsi, lac);
-		}
-	}
-
-	if (page_count <= 0)
-		LOGP(DBSSAP, LOGL_ERROR, "Could not deliver paging because none of the associated BSCs is available!\n");
-
-	return page_count;
-}
-
-/* Convert speech version field */
-static uint8_t convert_speech_version_l3_to_A(int speech_ver)
-{
-	/* The speech versions that are transmitted in the Bearer capability
-	 * information element, that is transmitted on the Layer 3 (CC)
-	 * use a different encoding than the permitted speech version
-	 * identifier, that is signalled in the channel type element on the A
-	 * interface. (See also 3GPP TS 48.008, 3.2.2.1 and 3GPP TS 24.008,
-	 * 10.5.103 */
-
-	switch (speech_ver) {
-	case GSM48_BCAP_SV_FR:
-		return GSM0808_PERM_FR1;
-	case GSM48_BCAP_SV_HR:
-		return GSM0808_PERM_HR1;
-	case GSM48_BCAP_SV_EFR:
-		return GSM0808_PERM_FR2;
-	case GSM48_BCAP_SV_AMR_F:
-		return GSM0808_PERM_FR3;
-	case GSM48_BCAP_SV_AMR_H:
-		return GSM0808_PERM_HR3;
-	case GSM48_BCAP_SV_AMR_OFW:
-		return GSM0808_PERM_FR4;
-	case GSM48_BCAP_SV_AMR_OHW:
-		return GSM0808_PERM_HR4;
-	case GSM48_BCAP_SV_AMR_FW:
-		return GSM0808_PERM_FR5;
-	case GSM48_BCAP_SV_AMR_OH:
-		return GSM0808_PERM_HR6;
-	}
-
-	/* If nothing matches, tag the result as invalid */
-	LOGP(DBSSAP, LOGL_ERROR, "Invalid permitted speech version: %d\n", speech_ver);
-	return 0xFF;
-}
-
-/* Convert speech preference field */
-static uint8_t convert_speech_pref_l3_to_A(int radio)
-{
-	/* The Radio channel requirement field that is transmitted in the
-	 * Bearer capability information element, that is transmitted on the
-	 * Layer 3 (CC) uses a different encoding than the Channel rate and
-	 * type field that is signalled in the channel type element on the A
-	 * interface. (See also 3GPP TS 48.008, 3.2.2.1 and 3GPP TS 24.008,
-	 * 10.5.102 */
-
-	switch (radio) {
-	case GSM48_BCAP_RRQ_FR_ONLY:
-		return GSM0808_SPEECH_FULL_BM;
-	case GSM48_BCAP_RRQ_DUAL_FR:
-		return GSM0808_SPEECH_FULL_PREF;
-	case GSM48_BCAP_RRQ_DUAL_HR:
-		return GSM0808_SPEECH_HALF_PREF;
-	}
-
-	LOGP(DBSSAP, LOGL_ERROR, "Invalid radio channel preference: %d; defaulting to full rate.\n",
-	     radio);
-	return GSM0808_SPEECH_FULL_BM;
-}
-
-/* Assemble the channel type field */
-static int enc_channel_type(struct gsm0808_channel_type *ct, const struct gsm_mncc_bearer_cap *bc)
-{
-	unsigned int i;
-	uint8_t sv;
-	unsigned int count = 0;
-	bool only_gsm_hr = true;
-
-	OSMO_ASSERT(ct);
-	OSMO_ASSERT(bc);
-
-	ct->ch_indctr = GSM0808_CHAN_SPEECH;
-
-	for (i = 0; i < ARRAY_SIZE(bc->speech_ver); i++) {
-		if (bc->speech_ver[i] == -1)
-			break;
-		sv = convert_speech_version_l3_to_A(bc->speech_ver[i]);
-		if (sv != 0xFF) {
-			/* Detect if something else than
-			 * GSM HR V1 is supported */
-			if (sv == GSM0808_PERM_HR2 ||
-			    sv == GSM0808_PERM_HR3 || sv == GSM0808_PERM_HR4 || sv == GSM0808_PERM_HR6)
-				only_gsm_hr = false;
-
-			ct->perm_spch[count] = sv;
-			count++;
-		}
-	}
-	ct->perm_spch_len = count;
-
-	if (only_gsm_hr)
-		/* Note: We must avoid the usage of GSM HR1 as this
-		 * codec only offers very poor audio quality. If the
-		 * MS only supports GSM HR1 (and full rate), and has
-		 * a preference for half rate. Then we will ignore the
-		 * preference and assume a preference for full rate. */
-		ct->ch_rate_type = GSM0808_SPEECH_FULL_BM;
-	else
-		ct->ch_rate_type = convert_speech_pref_l3_to_A(bc->radio);
-
-	if (count)
-		return 0;
-	else
-		return -EINVAL;
-}
-
-/* Assemble the speech codec field */
-static int enc_speech_codec_list(struct gsm0808_speech_codec_list *scl, const struct gsm0808_channel_type *ct)
-{
-	unsigned int i;
-	int rc;
-
-	memset(scl, 0, sizeof(*scl));
-	for (i = 0; i < ct->perm_spch_len; i++) {
-		rc = gsm0808_speech_codec_from_chan_type(&scl->codec[i], ct->perm_spch[i]);
-		if (rc != 0)
-			return -EINVAL;
-	}
-	scl->len = i;
-
-	return 0;
-}
-
-/* Send assignment request via A-interface */
-int a_iface_tx_assignment(const struct gsm_trans *trans)
-{
-	const struct ran_conn *conn;
-	struct gsm0808_channel_type ct;
-	struct gsm0808_speech_codec_list scl;
-	struct msgb *msg;
-	struct sockaddr_storage rtp_addr;
-	struct sockaddr_in rtp_addr_in;
-	int rc;
-
-	OSMO_ASSERT(trans);
-	conn = trans->conn;
-	OSMO_ASSERT(conn);
-
-	LOGPCONN(conn, LOGL_DEBUG, "Tx BSSMAP ASSIGNMENT COMMAND to BSC\n");
-
-	/* Channel type */
-	rc = enc_channel_type(&ct, &trans->bearer_cap);
-	if (rc < 0) {
-		LOGPCONN(conn, LOGL_ERROR, "Not sending Assignment to BSC: failed to generate channel type\n");
-		return -EINVAL;
-	}
-
-	/* Speech codec list */
-	rc = enc_speech_codec_list(&scl, &ct);
-	if (rc < 0) {
-		LOGPCONN(conn, LOGL_ERROR, "Not sending Assignment to BSC: failed to generate speech codec list\n");
-		return -EINVAL;
-	}
-
-	/* Package RTP-Address data */
-	memset(&rtp_addr_in, 0, sizeof(rtp_addr_in));
-	rtp_addr_in.sin_family = AF_INET;
-	rtp_addr_in.sin_port = osmo_htons(conn->rtp.local_port_ran);
-	rtp_addr_in.sin_addr.s_addr = inet_addr(conn->rtp.local_addr_ran);
-
-	if (rtp_addr_in.sin_addr.s_addr == INADDR_NONE) {
-		LOGPCONN(conn, LOGL_ERROR, "Invalid RTP-Address -- assignment not sent!\n");
-		return -EINVAL;
-	}
-	if (rtp_addr_in.sin_port == 0) {
-		LOGPCONN(conn, LOGL_ERROR, "Invalid RTP-Port -- assignment not sent!\n");
-		return -EINVAL;
-	}
-
-	memset(&rtp_addr, 0, sizeof(rtp_addr));
-	memcpy(&rtp_addr, &rtp_addr_in, sizeof(rtp_addr_in));
-
-	msg = gsm0808_create_ass(&ct, NULL, &rtp_addr, &scl, NULL);
-	return a_iface_tx_bssap(conn, msg);
-}
-
-/* Send clear command via A-interface */
-int a_iface_tx_clear_cmd(const struct ran_conn *conn)
-{
-	struct msgb *msg;
-	struct vlr_subscr *vsub = conn->vsub;
-	bool csfb_ind = false;
-
-	LOGPCONN(conn, LOGL_INFO, "Tx BSSMAP CLEAR COMMAND to BSC\n");
-
-	if (vsub && vsub->sgs_fsm->state == SGS_UE_ST_ASSOCIATED)
-		csfb_ind = true;
-
-	msg = gsm0808_create_clear_command2(GSM0808_CAUSE_CALL_CONTROL, csfb_ind);
-	return a_iface_tx_bssap(conn, msg);
-}
-
-int a_iface_tx_classmark_request(const struct ran_conn *conn)
-{
-	struct msgb *msg;
-
-	LOGPCONN(conn, LOGL_INFO, "Tx BSSMAP CLASSMARK REQUEST to BSC\n");
-
-	msg = gsm0808_create_classmark_request();
-	return a_iface_tx_bssap(conn, msg);
-}
-
-/* Callback function: Close all open connections */
-static void a_reset_cb(const void *priv)
-{
-	struct msgb *msg;
-	struct bsc_context *bsc_ctx = (struct bsc_context*) priv;
-	struct osmo_ss7_instance *ss7;
-
-	/* Skip if the A interface is not properly initalized yet */
-	if (!gsm_network)
-		return;
-
-	/* Clear all now orphaned RAN connections */
-	a_clear_all(bsc_ctx->sccp_user, &bsc_ctx->bsc_addr);
-
-	/* Send reset to the remote BSC */
-	ss7 = osmo_ss7_instance_find(gsm_network->a.cs7_instance);
-	OSMO_ASSERT(ss7);
-	LOGP(DBSSAP, LOGL_NOTICE, "Tx BSSMAP RESET to BSC %s\n", osmo_sccp_addr_name(ss7, &bsc_ctx->bsc_addr));
-	msg = gsm0808_create_reset();
-	osmo_sccp_tx_unitdata_msg(bsc_ctx->sccp_user, &bsc_ctx->msc_addr,
-				  &bsc_ctx->bsc_addr, msg);
-}
-
-/* Add a new BSC connection to our internal list with known BSCs */
-static struct bsc_context *add_bsc(const struct osmo_sccp_addr *msc_addr,
-				   const struct osmo_sccp_addr *bsc_addr, struct osmo_sccp_user *scu)
-{
-	struct bsc_context *bsc_ctx;
-	struct osmo_ss7_instance *ss7;
-
-	ss7 = osmo_ss7_instance_find(gsm_network->a.cs7_instance);
-	OSMO_ASSERT(ss7);
-	LOGP(DBSSAP, LOGL_NOTICE, "Adding new BSC connection for BSC %s...\n", osmo_sccp_addr_name(ss7, bsc_addr));
-
-	/* Generate and fill up a new bsc context */
-	bsc_ctx = talloc_zero(gsm_network, struct bsc_context);
-	OSMO_ASSERT(bsc_ctx);
-	memcpy(&bsc_ctx->bsc_addr, bsc_addr, sizeof(*bsc_addr));
-	memcpy(&bsc_ctx->msc_addr, msc_addr, sizeof(*msc_addr));
-	bsc_ctx->sccp_user = scu;
-	llist_add_tail(&bsc_ctx->list, &gsm_network->a.bscs);
-
-	return bsc_ctx;
-}
-
-/* start the BSSMAP RESET fsm */
-void a_start_reset(struct bsc_context *bsc_ctx, bool already_connected)
-{
-	char bsc_name[32];
-	OSMO_ASSERT(bsc_ctx->reset_fsm == NULL);
-	/* Start reset procedure to make the new connection active */
-	snprintf(bsc_name, sizeof(bsc_name), "bsc-%i", bsc_ctx->bsc_addr.pc);
-	bsc_ctx->reset_fsm = a_reset_alloc(bsc_ctx, bsc_name, a_reset_cb, bsc_ctx, already_connected);
-}
-
-/* determine if given msg is BSSMAP RESET related (true) or not (false) */
-static bool bssmap_is_reset(struct msgb *msg)
-{
-	struct bssmap_header *bs = (struct bssmap_header *)msgb_l2(msg);
-
-	if (msgb_l2len(msg) < sizeof(*bs))
-		return false;
-
-	if (bs->type != BSSAP_MSG_BSS_MANAGEMENT)
-		return false;
-
-	if (msg->l2h[sizeof(*bs)] == BSS_MAP_MSG_RESET)
-		return true;
-
-	if (msg->l2h[sizeof(*bs)] == BSS_MAP_MSG_RESET_ACKNOWLEDGE)
-		return true;
-
-	return false;
-}
-
-/* Callback function, called by the SSCP stack when data arrives */
-static int sccp_sap_up(struct osmo_prim_hdr *oph, void *_scu)
-{
-	struct osmo_sccp_user *scu = _scu;
-	struct osmo_scu_prim *scu_prim = (struct osmo_scu_prim *)oph;
-	int rc = 0;
-	struct a_conn_info a_conn_info;
-	struct bsc_conn *bsc_con;
-
-	memset(&a_conn_info, 0, sizeof(a_conn_info));
-	a_conn_info.network = gsm_network;
-
-	switch (OSMO_PRIM_HDR(&scu_prim->oph)) {
-	case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_INDICATION):
-		/* Handle inbound connection indication */
-		a_conn_info.conn_id = scu_prim->u.connect.conn_id;
-		a_conn_info.bsc = get_bsc_context_by_sccp_addr(&scu_prim->u.unitdata.calling_addr);
-		if (!a_conn_info.bsc) {
-			/* We haven't heard from this BSC before, allocate it */
-			a_conn_info.bsc = add_bsc(&scu_prim->u.connect.called_addr,
-						  &scu_prim->u.connect.calling_addr, scu);
-			a_start_reset(a_conn_info.bsc, false);
-		} else {
-			/* This BSC is already known to us, check if we have been through reset yet */
-			if (a_reset_conn_ready(a_conn_info.bsc->reset_fsm) == false) {
-				LOGP(DBSSAP, LOGL_NOTICE, "Refusing N-CONNECT.ind(%u, %s), BSC not reset yet\n",
-				     scu_prim->u.connect.conn_id, msgb_hexdump_l2(oph->msg));
-				rc = osmo_sccp_tx_disconn(scu, a_conn_info.conn_id, &a_conn_info.bsc->msc_addr,
-							  SCCP_RETURN_CAUSE_UNQUALIFIED);
-				break;
-			}
-
-			osmo_sccp_tx_conn_resp(scu, scu_prim->u.connect.conn_id, &scu_prim->u.connect.called_addr, NULL, 0);
-			if (msgb_l2len(oph->msg) > 0) {
-				LOGP(DBSSAP, LOGL_DEBUG, "N-CONNECT.ind(%u, %s)\n",
-				     scu_prim->u.connect.conn_id, msgb_hexdump_l2(oph->msg));
-				rc = a_sccp_rx_dt(scu, &a_conn_info, oph->msg);
-			} else {
-				LOGP(DBSSAP, LOGL_DEBUG, "N-CONNECT.ind(%u)\n", scu_prim->u.connect.conn_id);
-				rc = -ENODATA;
-			}
-
-			if (rc < 0) {
-				/* initial message (COMPL L3) caused some error, we didn't allocate
-				 * a subscriber_conn and must close the connection again */
-				rc = osmo_sccp_tx_disconn(scu, a_conn_info.conn_id,
-							  &a_conn_info.bsc->msc_addr,
-							  SCCP_RETURN_CAUSE_UNQUALIFIED);
-			} else
-				record_bsc_con(scu, a_conn_info.bsc, scu_prim->u.connect.conn_id);
-		}
-		break;
-
-	case OSMO_PRIM(OSMO_SCU_PRIM_N_DATA, PRIM_OP_INDICATION):
-		/* Handle incoming connection oriented data */
-		bsc_con = find_bsc_con(scu_prim->u.data.conn_id);
-		if (!bsc_con) {
-			LOGP(DBSSAP, LOGL_ERROR, "N-DATA.ind(%u, %s) for unknown conn_id\n",
-				scu_prim->u.data.conn_id, msgb_hexdump_l2(oph->msg));
-			break;
-		}
-		a_conn_info.conn_id = scu_prim->u.data.conn_id;
-		a_conn_info.bsc = bsc_con->bsc;
-		LOGP(DBSSAP, LOGL_DEBUG, "N-DATA.ind(%u, %s)\n",
-		     scu_prim->u.data.conn_id, msgb_hexdump_l2(oph->msg));
-		a_sccp_rx_dt(scu, &a_conn_info, oph->msg);
-		break;
-
-	case OSMO_PRIM(OSMO_SCU_PRIM_N_UNITDATA, PRIM_OP_INDICATION):
-		/* Handle inbound UNITDATA */
-
-		/* Get BSC context, create a new one if necessary */
-		a_conn_info.bsc = get_bsc_context_by_sccp_addr(&scu_prim->u.unitdata.calling_addr);
-		if (!a_conn_info.bsc) {
-			/* We haven't heard from this BSC before, allocate it */
-			a_conn_info.bsc = add_bsc(&scu_prim->u.unitdata.called_addr,
-						&scu_prim->u.unitdata.calling_addr, scu);
-			/* Make sure that reset procedure is started */
-			a_start_reset(a_conn_info.bsc, false);
-		}
-
-		/* As long as we are in the reset phase, only reset related BSSMAP messages may pass
-		 * beond here. */
-		if (!bssmap_is_reset(oph->msg) && a_reset_conn_ready(a_conn_info.bsc->reset_fsm) == false) {
-			LOGP(DBSSAP, LOGL_NOTICE, "Ignoring N-UNITDATA.ind(%s), BSC not reset yet\n",
-			     msgb_hexdump_l2(oph->msg));
-			break;
-		}
-
-		DEBUGP(DBSSAP, "N-UNITDATA.ind(%s)\n", msgb_hexdump_l2(oph->msg));
-		a_sccp_rx_udt(scu, &a_conn_info, oph->msg);
-		break;
-
-	default:
-		LOGP(DBSSAP, LOGL_ERROR, "Unhandled SIGTRAN operation %s on primitive %u\n",
-		     get_value_string(osmo_prim_op_names, oph->operation), oph->primitive);
-		break;
-	}
-
-	/* We didn't transfer msgb ownership to any downstream functions so we rely on
-	 * this single/central location to free() the msgb wrapping the primitive */
-	msgb_free(oph->msg);
-	return rc;
-}
-
-/* Clear all RAN connections on a specified BSC */
-void a_clear_all(struct osmo_sccp_user *scu, const struct osmo_sccp_addr *bsc_addr)
-{
-	struct ran_conn *conn;
-	struct ran_conn *conn_temp;
-	struct gsm_network *network = gsm_network;
-
-	OSMO_ASSERT(scu);
-	OSMO_ASSERT(bsc_addr);
-
-	llist_for_each_entry_safe(conn, conn_temp, &network->ran_conns, entry) {
-		/* Clear only A connections and connections that actually
-		 * belong to the specified BSC */
-		if (conn->via_ran == OSMO_RAT_GERAN_A && memcmp(bsc_addr, &conn->a.bsc_addr, sizeof(conn->a.bsc_addr)) == 0) {
-			uint32_t conn_id = conn->a.conn_id;
-			LOGPCONN(conn, LOGL_NOTICE, "Dropping orphaned RAN connection\n");
-			/* This call will/may talloc_free(conn), so we must save conn_id above */
-			ran_conn_clear_request(conn, GSM48_CC_CAUSE_SWITCH_CONG);
-
-			/* If there is still an SCCP connection active, remove it now */
-			if (check_connection_active(conn_id)) {
-				osmo_sccp_tx_disconn(scu, conn_id, bsc_addr,
-						     SCCP_RELEASE_CAUSE_END_USER_ORIGINATED);
-				a_delete_bsc_con(conn_id);
-			}
-		}
-	}
-}
-
-/* Initalize A interface connection between to MSC and BSC */
-int a_init(struct osmo_sccp_instance *sccp, struct gsm_network *network)
-{
-	OSMO_ASSERT(sccp);
-	OSMO_ASSERT(network);
-
-	/* FIXME: Remove hardcoded parameters, use parameters in parameter list */
-	LOGP(DBSSAP, LOGL_NOTICE, "Initalizing SCCP connection to stp...\n");
-
-	/* Set GSM network variable, there can only be
-	 * one network by design */
-	if (gsm_network != NULL) {
-		OSMO_ASSERT(gsm_network == network);
-	} else
-		gsm_network = network;
-
-	/* SCCP Protocol stack */
-	osmo_sccp_user_bind(sccp, "OsmoMSC-A", sccp_sap_up, SCCP_SSN_BSSAP);
-
-	return 0;
-}