diff options
Diffstat (limited to 'openbsc/src/libmsc/a_iface.c')
| -rw-r--r-- | openbsc/src/libmsc/a_iface.c | 218 |
1 files changed, 197 insertions, 21 deletions
diff --git a/openbsc/src/libmsc/a_iface.c b/openbsc/src/libmsc/a_iface.c index caf9d4b06..3e5ffca87 100644 --- a/openbsc/src/libmsc/a_iface.c +++ b/openbsc/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 +18,212 @@ * */ +#include <osmocom/core/utils.h> #include <osmocom/core/msgb.h> #include <osmocom/core/logging.h> - +#include <osmocom/sigtran/sccp_helpers.h> +#include <osmocom/gsm/gsm0808.h> +#include <osmocom/gsm/protocol/gsm_08_08.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> +/* 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; + +/* Send DTAP message via A-interface */ int a_tx(struct msgb *msg) { - 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 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); +} + +/* Send Cipher mode command via A-interface */ +int msc_gsm0808_tx_cipher_mode(struct gsm_subscriber_connection *conn, + int cipher, const uint8_t *key, int len, int include_imeisv) +{ + /* TODO generalize for A- and Iu interfaces, don't name after 08.08 */ + struct msgb *msg_resp; + struct gsm0808_encrypt_info ei; + 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_page(const char *imsi, uint32_t tmsi, uint16_t lac) { - 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 a_bsc_addr *addr; + struct llist_head *bsc_addr_list = get_bsc_addr_list(); + struct gsm0808_cell_id_list cil; + int page_count = 0; + + cil.id_discr = CELL_IDENT_LAC; + cil.id_list_lac[0] = lac; + cil.id_list_len = 1; + + /* Deliver paging request to all known BSCs */ + llist_for_each_entry(addr, bsc_addr_list, list) { + LOGP(DMSC, LOGL_DEBUG, "Passing paging message from MSC to BSC %s (imsi=%s, tmsi=0x%08x, lac=%u)\n", + osmo_sccp_addr_dump(&addr->calling_addr), imsi, tmsi, lac); + osmo_sccp_tx_unitdata_msg(addr->scu, &addr->called_addr, &addr->calling_addr, + gsm0808_create_paging(imsi, &tmsi, &cil, NULL)); + page_count++; + } + + if (page_count <= 0) + LOGP(DMSC, LOGL_ERROR, "Could not deliver paging because no BSC is available!\n"); + + return page_count; +} + +/* Send assignment request via A-interface */ +int a_assign(struct gsm_trans *trans) +{ + struct gsm_subscriber_connection *conn; + struct gsm0808_channel_type ct; + uint16_t cic; + uint16_t *cic_ptr = NULL; + struct sockaddr_storage *ss = NULL; + struct gsm0808_speech_codec_list *scl = NULL; + uint32_t *ci_ptr = NULL; + + conn = trans->conn; + OSMO_ASSERT(conn); + struct msgb *msg; + + /* FIXME: This is still work in progress */ + /* Some fake parameters for testing */ + ct.ch_indctr = GSM0808_CHAN_SPEECH; + ct.ch_rate_type = GSM0808_SPEECH_FULL_BM; + ct.perm_spch[0] = GSM0808_PERM_FR1; + ct.perm_spch_len = 1; + + cic = 0x0023; + cic_ptr = &cic; + + msg = gsm0808_create_ass(&ct, cic_ptr, ss, 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); + } -int msc_gsm0808_tx_cipher_mode(struct gsm_subscriber_connection *conn, int cipher, - const uint8_t *key, int len, int include_imeisv) +/* Callback function, called by the SSCP stack when data arrives */ +static int sccp_sap_up(struct osmo_prim_hdr *oph, void *_scu) { - /* 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 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; + + 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.called_addr = &scu_prim->u.connect.called_addr; + a_conn_info.calling_addr = &scu_prim->u.connect.calling_addr; + 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 = msc_handle_dt1(scu, &a_conn_info, oph->msg); + } else + LOGP(DMSC, LOGL_DEBUG, "N-CONNECT.ind(%u)\n", 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))); + msc_handle_dt1(scu, &a_conn_info, oph->msg); + break; + + case OSMO_PRIM(OSMO_SCU_PRIM_N_UNITDATA, PRIM_OP_INDICATION): + /* Handle inbound UNITDATA */ + a_conn_info.called_addr = &scu_prim->u.unitdata.called_addr; + a_conn_info.calling_addr = &scu_prim->u.unitdata.calling_addr; + msc_handle_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; +} + +/* Initalize A interface connection between to MSC and BSC */ +int a_init(void *ctx, const char *name, uint32_t local_pc, + const char *listen_addr, const char *remote_addr, uint16_t local_port, struct gsm_network *network) +{ + /* FIXME: Clean this up! */ + /* FIXME: Don't use the simple_server, use the simple_client instead! */ +#define RECEIVER_PC 23 +#define SSN_BSSAP 254 /* SCCP_SSN_BSSAP */ +#define SENDER_PC 1 + + struct osmo_sccp_instance *sccp; + + gsm_network = network; + osmo_ss7_init(); + + sccp = osmo_sccp_simple_server(NULL, SENDER_PC, OSMO_SS7_ASP_PROT_M3UA, -1, "127.0.0.2"); + + /* Why? */ + osmo_sccp_simple_server_add_clnt(sccp, OSMO_SS7_ASP_PROT_M3UA, "RECEIVER", RECEIVER_PC, -1, 0, NULL); + + osmo_sccp_user_bind(sccp, "MSC", &sccp_sap_up, SSN_BSSAP); + + return 0; } |