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authorPhilipp Maier <pmaier@sysmocom.de>2017-04-12 15:19:45 +0200
committerNeels Hofmeyr <nhofmeyr@sysmocom.de>2017-06-18 17:50:08 +0200
commit76174d9dd94bb88ae63e616e84ae58b9f290e92b (patch)
tree90898e2087f5485041f2da74edcb3ea5596f2123 /openbsc/src/libmsc/a_iface.c
parente3aca93630e7a4572bd0459115b25348e1840c0e (diff)
WIP: Integrate AoIP into MSC
Diffstat (limited to 'openbsc/src/libmsc/a_iface.c')
-rw-r--r--openbsc/src/libmsc/a_iface.c218
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;
}