diff options
Diffstat (limited to 'src/libmsc/a_iface.c')
-rw-r--r-- | src/libmsc/a_iface.c | 582 |
1 files changed, 560 insertions, 22 deletions
diff --git a/src/libmsc/a_iface.c b/src/libmsc/a_iface.c index caf9d4b06..93e8ab5e9 100644 --- a/src/libmsc/a_iface.c +++ b/src/libmsc/a_iface.c @@ -1,9 +1,8 @@ -/* A-interface implementation, from MSC to BSC */ - -/* (C) 2016 by sysmocom s.m.f.c GmbH <info@sysmocom.de> - * +/* (C) 2017 by sysmocom s.f.m.c. GmbH * 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 @@ -19,35 +18,574 @@ * */ +#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 <openbsc/debug.h> - -#include <openbsc/gsm_data.h> #include <openbsc/msc_ifaces.h> -#include <openbsc/debug.h> +#include <openbsc/a_iface.h> +#include <openbsc/a_iface_bssap.h> +#include <openbsc/transaction.h> +#include <openbsc/mgcpgw_client.h> +#include <osmocom/core/byteswap.h> +#include <osmocom/sccp/sccp_types.h> +#include <openbsc/a_reset.h> +#include <openbsc/osmo_msc.h> + +/* 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 */ +}; + +/* 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, uint32_t conn_id) +{ + struct bsc_conn *conn; + + conn = talloc_zero(ctx, struct bsc_conn); + OSMO_ASSERT(conn); + + conn->conn_id = conn_id; + + 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; + + LOGP(DMSC, LOGL_DEBUG, + "Removing connection from active sccp-connection list (conn_id=%i)\n", + conn_id); + + llist_for_each_entry_safe(conn, conn_temp, &active_connections, list) { + if (conn->conn_id == conn_id) { + llist_del(&conn->list); + talloc_free(conn); + } + } +} + +/* Check if a specified connection id has an active SCCP connection */ +static bool check_connection_active(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 true; + } + } + + return false; +} -int a_tx(struct msgb *msg) +/* Get the reset context for a specifiec calling (BSC) address */ +static struct a_reset_ctx *get_reset_ctx_by_sccp_addr(const struct osmo_sccp_addr *addr) { - LOGP(DMSC, LOGL_ERROR, "message to be sent to BSC, but A-interface" - " not implemented.\n%s\n", osmo_hexdump(msg->data, msg->len)); - return -1; + 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->reset; + } + + ss7 = osmo_ss7_instance_find(gsm_network->a.cs7_instance); + OSMO_ASSERT(ss7); + LOGP(DMSC, LOGL_ERROR, "The calling BSC (%s) is unknown to this MSC ...\n", + osmo_sccp_addr_name(ss7, addr)); + return NULL; } -int a_page(const char *imsi, uint32_t tmsi, uint16_t lac) +/* Send DTAP message via A-interface */ +int a_iface_tx_dtap(struct msgb *msg) { - LOGP(DMSC, LOGL_ERROR, "Paging to be sent to BSC, but A-interface" - " not implemented: IMSI %s TMSI 0x%08x LAC %u\n", - imsi, tmsi, lac); - return -1; + struct gsm_subscriber_connection *conn; + struct msgb *msg_resp; + + /* FIXME: Set this to some meaninful value! */ + uint8_t link_id = 0x00; + OSMO_ASSERT(msg); + conn = (struct gsm_subscriber_connection *)msg->dst; + OSMO_ASSERT(conn); + OSMO_ASSERT(conn->a.scu); + + LOGP(DMSC, LOGL_DEBUG, "Passing DTAP message from MSC to BSC (conn_id=%i)\n", conn->a.conn_id); + + msg->l3h = msg->data; + msg_resp = gsm0808_create_dtap(msg, link_id); + if (!msg_resp) { + LOGP(DMSC, LOGL_ERROR, "Unable to generate BSSMAP DTAP message!\n"); + return -EINVAL; + } else + LOGP(DMSC, LOGL_DEBUG, "Massage will be sent as BSSMAP DTAP message!\n"); + + LOGP(DMSC, LOGL_DEBUG, "N-DATA.req(%u, %s)\n", conn->a.conn_id, osmo_hexdump(msg_resp->data, msg_resp->len)); + return osmo_sccp_tx_data_msg(conn->a.scu, conn->a.conn_id, msg_resp); } -int msc_gsm0808_tx_cipher_mode(struct gsm_subscriber_connection *conn, int cipher, - const uint8_t *key, int len, int include_imeisv) +/* Send Cipher mode command via A-interface */ +int a_iface_tx_cipher_mode(const struct gsm_subscriber_connection *conn, + int cipher, const const uint8_t *key, int len, int include_imeisv) { /* TODO generalize for A- and Iu interfaces, don't name after 08.08 */ - LOGP(DMSC, LOGL_ERROR, "gsm0808_cipher_mode(): message to be sent to" - " BSC, but A interface not yet implemented.\n"); - return -1; + struct msgb *msg_resp; + struct gsm0808_encrypt_info ei; + + OSMO_ASSERT(conn); + + LOGP(DMSC, LOGL_DEBUG, "Passing Cipher mode command message from MSC to BSC (conn_id=%i)\n", conn->a.conn_id); + uint8_t crm = 0x01; + uint8_t *crm_ptr = NULL; + + /* Setup encryption information */ + if (len > ENCRY_INFO_KEY_MAXLEN || !key) { + LOGP(DMSC, LOGL_ERROR, + "Cipher mode command message could not be generated due to invalid key! (conn_id=%i)\n", + conn->a.conn_id); + return -EINVAL; + } else { + memcpy(&ei.key, key, len); + ei.key_len = len; + } + + if (include_imeisv) + crm_ptr = &crm; + + ei.perm_algo[0] = (uint8_t) (1 << cipher); + ei.perm_algo_len = 1; + + msg_resp = gsm0808_create_cipher(&ei, crm_ptr); + LOGP(DMSC, LOGL_DEBUG, "N-DATA.req(%u, %s)\n", conn->a.conn_id, osmo_hexdump(msg_resp->data, msg_resp->len)); + + return osmo_sccp_tx_data_msg(conn->a.scu, conn->a.conn_id, 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_list 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_lac[0] = 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)) { + LOGP(DMSC, LOGL_DEBUG, + "Passing 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_paging(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(DMSC, 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(DMSC, 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_Abis_sv_to_A_sv(int speech_ver) +{ + /* The speech versions that are transmitted in the Bearer capability + * information element, that is transmitted on the Abis interfece + * 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; + break; + case GSM48_BCAP_SV_HR: + return GSM0808_PERM_HR1; + break; + case GSM48_BCAP_SV_EFR: + return GSM0808_PERM_FR2; + break; + case GSM48_BCAP_SV_AMR_F: + return GSM0808_PERM_FR3; + break; + case GSM48_BCAP_SV_AMR_H: + return GSM0808_PERM_HR3; + break; + case GSM48_BCAP_SV_AMR_OFW: + return GSM0808_PERM_FR4; + break; + case GSM48_BCAP_SV_AMR_OHW: + return GSM0808_PERM_HR4; + break; + case GSM48_BCAP_SV_AMR_FW: + return GSM0808_PERM_FR5; + break; + case GSM48_BCAP_SV_AMR_OH: + return GSM0808_PERM_HR6; + break; + } + + /* If nothing matches, tag the result as invalid */ + LOGP(DMSC, LOGL_ERROR, "Invalid permitted speech version / rate detected, discarding.\n"); + return 0xFF; +} + +/* Convert speech preference field */ +static uint8_t convert_Abis_prev_to_A_pref(int radio) +{ + /* The Radio channel requirement field that is transmitted in the + * Bearer capability information element, that is transmitted on the + * Abis interfece 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(DMSC, LOGL_ERROR, "Invalid speech version / rate combination preference, defaulting to full rate.\n"); + 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_Abis_sv_to_A_sv(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_Abis_prev_to_A_pref(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) +{ + struct gsm_subscriber_connection *conn; + struct gsm0808_channel_type ct; + struct gsm0808_speech_codec_list scl; + uint32_t *ci_ptr = NULL; + 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); + + LOGP(DMSC, LOGL_ERROR, "Sending assignment command to BSC (conn_id %u)\n", conn->a.conn_id); + + /* Channel type */ + rc = enc_channel_type(&ct, &trans->bearer_cap); + if (rc < 0) { + LOGP(DMSC, LOGL_ERROR, "Faild to generate channel type -- assignment not sent!\n"); + return -EINVAL; + } + + /* Speech codec list */ + rc = enc_speech_codec_list(&scl, &ct); + if (rc < 0) { + LOGP(DMSC, LOGL_ERROR, "Faild to generate Speech codec list -- assignment not sent!\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.port_subscr); + rtp_addr_in.sin_addr.s_addr = osmo_htonl(mgcpgw_client_remote_addr_n(gsm_network->mgcpgw.client)); + + 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, ci_ptr); + + LOGP(DMSC, LOGL_DEBUG, "N-DATA.req(%u, %s)\n", conn->a.conn_id, osmo_hexdump(msg->data, msg->len)); + return osmo_sccp_tx_data_msg(conn->a.scu, conn->a.conn_id, msg); +} + +/* Send clear command via A-interface */ +int a_iface_tx_clear_cmd(struct gsm_subscriber_connection *conn) +{ + struct msgb *msg; + + LOGP(DMSC, LOGL_NOTICE, "Sending clear command to BSC (conn_id=%u)\n", conn->a.conn_id); + + msg = gsm0808_create_clear_command(GSM0808_CAUSE_CALL_CONTROL); + return osmo_sccp_tx_data_msg(conn->a.scu, conn->a.conn_id, 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 subscriber 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(DMSC, LOGL_NOTICE, "Sending 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 void 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; + + OSMO_ASSERT(bsc_addr); + OSMO_ASSERT(msc_addr); + OSMO_ASSERT(scu); + + /* Check if we already know this BSC, if yes, skip adding it. */ + if (get_reset_ctx_by_sccp_addr(bsc_addr)) + return; + + ss7 = osmo_ss7_instance_find(gsm_network->a.cs7_instance); + OSMO_ASSERT(ss7); + LOGP(DMSC, 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); + + /* Start reset procedure to make the new connection active */ + bsc_ctx->reset = a_reset_alloc(bsc_ctx, osmo_sccp_addr_name(ss7, bsc_addr), a_reset_cb, bsc_ctx); +} + +/* 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; + memset(&a_conn_info, 0, sizeof(a_conn_info)); + a_conn_info.network = gsm_network; + a_conn_info.reset = NULL; + + switch (OSMO_PRIM_HDR(&scu_prim->oph)) { + case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_INDICATION): + /* Handle inbound connection indication */ + add_bsc(&scu_prim->u.connect.called_addr, &scu_prim->u.connect.calling_addr, scu); + a_conn_info.conn_id = scu_prim->u.connect.conn_id; + a_conn_info.msc_addr = &scu_prim->u.connect.called_addr; + a_conn_info.bsc_addr = &scu_prim->u.connect.calling_addr; + a_conn_info.reset = get_reset_ctx_by_sccp_addr(&scu_prim->u.unitdata.calling_addr); + + if (a_reset_conn_ready(a_conn_info.reset) == false) { + rc = osmo_sccp_tx_disconn(scu, a_conn_info.conn_id, a_conn_info.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(DMSC, LOGL_DEBUG, "N-CONNECT.ind(%u, %s)\n", + scu_prim->u.connect.conn_id, osmo_hexdump(msgb_l2(oph->msg), msgb_l2len(oph->msg))); + rc = sccp_rx_dt(scu, &a_conn_info, oph->msg); + } else + LOGP(DMSC, LOGL_DEBUG, "N-CONNECT.ind(%u)\n", scu_prim->u.connect.conn_id); + + record_bsc_con(scu, scu_prim->u.connect.conn_id); + break; + + case OSMO_PRIM(OSMO_SCU_PRIM_N_DATA, PRIM_OP_INDICATION): + /* Handle incoming connection oriented data */ + a_conn_info.conn_id = scu_prim->u.data.conn_id; + LOGP(DMSC, LOGL_DEBUG, "N-DATA.ind(%u, %s)\n", + scu_prim->u.data.conn_id, osmo_hexdump(msgb_l2(oph->msg), msgb_l2len(oph->msg))); + sccp_rx_dt(scu, &a_conn_info, oph->msg); + break; + + case OSMO_PRIM(OSMO_SCU_PRIM_N_UNITDATA, PRIM_OP_INDICATION): + /* Handle inbound UNITDATA */ + add_bsc(&scu_prim->u.unitdata.called_addr, &scu_prim->u.unitdata.calling_addr, scu); + a_conn_info.msc_addr = &scu_prim->u.unitdata.called_addr; + a_conn_info.bsc_addr = &scu_prim->u.unitdata.calling_addr; + a_conn_info.reset = get_reset_ctx_by_sccp_addr(&scu_prim->u.unitdata.calling_addr); + DEBUGP(DMSC, "N-UNITDATA.ind(%s)\n", osmo_hexdump(msgb_l2(oph->msg), msgb_l2len(oph->msg))); + sccp_rx_udt(scu, &a_conn_info, oph->msg); + break; + + default: + LOGP(DMSC, LOGL_ERROR, "Unhandled SIGTRAN primitive: %u:%u\n", oph->primitive, oph->operation); + break; + } + + return rc; +} + +/* Clear all subscriber connections on a specified BSC */ +void a_clear_all(struct osmo_sccp_user *scu, const struct osmo_sccp_addr *bsc_addr) +{ + struct gsm_subscriber_connection *conn; + struct gsm_subscriber_connection *conn_temp; + struct gsm_network *network = gsm_network; + + OSMO_ASSERT(scu); + OSMO_ASSERT(bsc_addr); + + llist_for_each_entry_safe(conn, conn_temp, &network->subscr_conns, entry) { + /* Clear only A connections and connections that actually + * belong to the specified BSC */ + if (conn->via_ran == RAN_GERAN_A && memcmp(bsc_addr, &conn->a.bsc_addr, sizeof(conn->a.bsc_addr)) == 0) { + LOGP(DMSC, LOGL_NOTICE, "Dropping orphaned subscriber connection (conn_id %i)\n", + conn->a.conn_id); + msc_clear_request(conn, GSM48_CC_CAUSE_SWITCH_CONG); + + /* If there is still an SCCP connection active, remove it now */ + if (check_connection_active(conn->a.conn_id)) { + osmo_sccp_tx_disconn(scu, conn->a.conn_id, bsc_addr, + SCCP_RELEASE_CAUSE_END_USER_ORIGINATED); + a_delete_bsc_con(conn->a.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(DMSC, 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; } |