summaryrefslogtreecommitdiffstats
path: root/openbsc/src/libmsc/msc_ifaces.c
blob: d3390fcb2ed9a8869dd953b7f56c029d114c3a3c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
/* Implementation for MSC decisions which interface to send messages out on. */

/* (C) 2016 by sysmocom s.m.f.c GmbH <info@sysmocom.de>
 *
 * All Rights Reserved
 *
 * 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/logging.h>

#include <openbsc/debug.h>
#include <openbsc/gsm_data.h>
#include <openbsc/msc_ifaces.h>
#include <openbsc/iu.h>
#include <openbsc/gsm_subscriber.h>
#include <openbsc/transaction.h>
#include <openbsc/mgcp.h>
#include <openbsc/mgcpgw_client.h>
#include <openbsc/vlr.h>

#include "../../bscconfig.h"

extern struct msgb *ranap_new_msg_rab_assign_voice(uint8_t rab_id,
						   uint32_t rtp_ip,
						   uint16_t rtp_port,
						   bool use_x213_nsap);

static int msc_tx(struct gsm_subscriber_connection *conn, struct msgb *msg)
{
	DEBUGP(DMSC, "msc_tx %u bytes to %s via %s\n",
	       msg->len, vlr_subscr_name(conn->vsub),
	       ran_type_name(conn->via_ran));
	switch (conn->via_ran) {
	case RAN_GERAN_A:
		msg->dst = conn;
		return a_tx(msg);

	case RAN_UTRAN_IU:
		msg->dst = conn->iu.ue_ctx;
		return iu_tx(msg, 0);

	default:
		LOGP(DMSC, LOGL_ERROR,
		     "msc_tx(): conn->via_ran invalid (%d)\n",
		     conn->via_ran);
		return -1;
	}
}


int msc_tx_dtap(struct gsm_subscriber_connection *conn,
		struct msgb *msg)
{
	return msc_tx(conn, msg);
}


/* 9.2.5 CM service accept */
int msc_gsm48_tx_mm_serv_ack(struct gsm_subscriber_connection *conn)
{
	struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 SERV ACC");
	struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));

	gh->proto_discr = GSM48_PDISC_MM;
	gh->msg_type = GSM48_MT_MM_CM_SERV_ACC;

	DEBUGP(DMM, "-> CM SERVICE ACCEPT\n");

	return msc_tx_dtap(conn, msg);
}

/* 9.2.6 CM service reject */
int msc_gsm48_tx_mm_serv_rej(struct gsm_subscriber_connection *conn,
			     enum gsm48_reject_value value)
{
	struct msgb *msg;

	msg = gsm48_create_mm_serv_rej(value);
	if (!msg) {
		LOGP(DMM, LOGL_ERROR, "Failed to allocate CM Service Reject.\n");
		return -1;
	}

	DEBUGP(DMM, "-> CM SERVICE Reject cause: %d\n", value);

	return msc_tx_dtap(conn, msg);
}

int msc_tx_common_id(struct gsm_subscriber_connection *conn)
{
	/* Common ID is only sent over IuCS */
	if (conn->via_ran != RAN_UTRAN_IU) {
		LOGP(DMM, LOGL_INFO,
		     "%s: Asked to transmit Common ID, but skipping"
		     " because this is not on UTRAN\n",
		     vlr_subscr_name(conn->vsub));
		return 0;
	}

#ifdef BUILD_IU
	DEBUGP(DIUCS, "%s: tx CommonID %s\n",
	       vlr_subscr_name(conn->vsub), conn->vsub->imsi);
	return iu_tx_common_id(conn->iu.ue_ctx, conn->vsub->imsi);
#else
	LOGP(DMM, LOGL_ERROR,
	     "Cannot send CommonID: RAN_UTRAN_IU but IuCS support not built\n");
	return -ENOTSUP;
#endif
}

#ifdef BUILD_IU
static void iu_rab_act_cs(struct ue_conn_ctx *uectx, uint8_t rab_id,
			  uint32_t rtp_ip, uint16_t rtp_port)
{
	struct msgb *msg;
	bool use_x213_nsap;
	uint32_t conn_id = uectx->conn_id;

	use_x213_nsap = (uectx->rab_assign_addr_enc == NSAP_ADDR_ENC_X213);

	LOGP(DIUCS, LOGL_DEBUG, "Assigning RAB: conn_id=%u, rab_id=%d,"
	     " rtp=%x:%u, use_x213_nsap=%d\n", conn_id, rab_id, rtp_ip,
	     rtp_port, use_x213_nsap);

	msg = ranap_new_msg_rab_assign_voice(rab_id, rtp_ip, rtp_port,
					     use_x213_nsap);
	msg->l2h = msg->data;

	if (iu_rab_act(uectx, msg))
		LOGP(DIUCS, LOGL_ERROR, "Failed to send RAB Assignment:"
		     " conn_id=%d rab_id=%d rtp=%x:%u\n",
		     conn_id, rab_id, rtp_ip, rtp_port);
}

static void mgcp_response_rab_act_cs_crcx(struct mgcp_response *r, void *priv)
{
	struct gsm_trans *trans = priv;
	struct gsm_subscriber_connection *conn = trans->conn;
	struct ue_conn_ctx *uectx = conn->iu.ue_ctx;
	uint32_t rtp_ip;
	int rc;

	if (r->head.response_code != 200) {
		LOGP(DMGCP, LOGL_ERROR,
		     "MGCPGW response yields error: %d %s\n",
		     r->head.response_code, r->head.comment);
		goto rab_act_cs_error;
	}

	rc = mgcp_response_parse_params(r);
	if (rc) {
		LOGP(DMGCP, LOGL_ERROR,
		     "Cannot parse MGCP response, for %s\n",
		     vlr_subscr_name(trans->vsub));
		goto rab_act_cs_error;
	}

	conn->iu.mgcp_rtp_port_cn = r->audio_port;

	rtp_ip = mgcpgw_client_remote_addr_n(conn->network->mgcpgw.client);
	iu_rab_act_cs(uectx, conn->iu.rab_id, rtp_ip,
		      conn->iu.mgcp_rtp_port_ue);
	/* use_x213_nsap == 0 for ip.access nano3G */

rab_act_cs_error:
	/* FIXME abort call, invalidate conn, ... */
	return;
}

static int conn_iu_rab_act_cs(struct gsm_trans *trans)
{
	struct gsm_subscriber_connection *conn = trans->conn;
	struct mgcpgw_client *mgcp = conn->network->mgcpgw.client;
	struct msgb *msg;

	/* HACK. where to scope the RAB Id? At the conn / subscriber /
	 * ue_conn_ctx? */
	static uint8_t next_rab_id = 1;
	conn->iu.rab_id = next_rab_id ++;

	conn->iu.mgcp_rtp_endpoint =
		mgcpgw_client_next_endpoint(conn->network->mgcpgw.client);
	/* HACK: the addresses should be known from CRCX response
	 * and config. */
	conn->iu.mgcp_rtp_port_ue = 4000 + 2 * conn->iu.mgcp_rtp_endpoint;

	/* Establish the RTP stream first as looping back to the originator.
	 * The MDCX will patch through to the counterpart. TODO: play a ring
	 * tone instead. */
	msg = mgcp_msg_crcx(mgcp, conn->iu.mgcp_rtp_endpoint, trans->callref,
			    MGCP_CONN_LOOPBACK);
	return mgcpgw_client_tx(mgcp, msg, mgcp_response_rab_act_cs_crcx, trans);
}
#endif

int msc_call_assignment(struct gsm_trans *trans)
{
	struct gsm_subscriber_connection *conn = trans->conn;

	switch (conn->via_ran) {
	case RAN_GERAN_A:
		LOGP(DMSC, LOGL_ERROR,
		     "msc_call_assignment(): A-interface BSSMAP Assignment"
		     " Request not yet implemented\n");
		return -ENOTSUP;

	case RAN_UTRAN_IU:
#ifdef BUILD_IU
		return conn_iu_rab_act_cs(trans);
#else
		LOGP(DMSC, LOGL_ERROR,
		     "msc_call_assignment(): IuCS RAB Activation not supported"
		     " in this build\n");
		return -ENOTSUP;
#endif

	default:
		LOGP(DMSC, LOGL_ERROR,
		     "msc_tx(): conn->via_ran invalid (%d)\n",
		     conn->via_ran);
		return -EINVAL;
	}
}

static void mgcp_response_bridge_mdcx(struct mgcp_response *r, void *priv);

static void mgcp_bridge(struct gsm_trans *from, struct gsm_trans *to,
			enum bridge_state state,
			enum mgcp_connection_mode mode)
{
	struct gsm_subscriber_connection *conn1 = from->conn;
	struct gsm_subscriber_connection *conn2 = to->conn;
	struct mgcpgw_client *mgcp = conn1->network->mgcpgw.client;
	const char *ip;
	struct msgb *msg;

	OSMO_ASSERT(mgcp);

	from->bridge.peer = to;
	from->bridge.state = state;

	/* Loop back to the same MGCP GW */
	ip = mgcpgw_client_remote_addr_str(mgcp);

	msg = mgcp_msg_mdcx(mgcp,
			    conn1->iu.mgcp_rtp_endpoint,
			    ip, conn2->iu.mgcp_rtp_port_cn,
			    mode);
	if (mgcpgw_client_tx(mgcp, msg, mgcp_response_bridge_mdcx, from))
		LOGP(DMGCP, LOGL_ERROR,
		     "Failed to send MDCX message for %s\n",
		     vlr_subscr_name(from->vsub));
}

static void mgcp_response_bridge_mdcx(struct mgcp_response *r, void *priv)
{
	struct gsm_trans *trans = priv;
	struct gsm_trans *peer = trans->bridge.peer;

	switch (trans->bridge.state) {
	case BRIDGE_STATE_LOOPBACK_PENDING:
		trans->bridge.state = BRIDGE_STATE_LOOPBACK_ESTABLISHED;

		switch (peer->bridge.state) {
		case BRIDGE_STATE_LOOPBACK_PENDING:
			/* Wait until the other is done as well. */
			return;
		case BRIDGE_STATE_LOOPBACK_ESTABLISHED:
			/* Now that both are in loopback, switch both to
			 * forwarding. */
			mgcp_bridge(trans, peer, BRIDGE_STATE_BRIDGE_PENDING,
				    MGCP_CONN_RECV_SEND);
			mgcp_bridge(peer, trans, BRIDGE_STATE_BRIDGE_PENDING,
				    MGCP_CONN_RECV_SEND);
			break;
		default:
			LOGP(DMGCP, LOGL_ERROR,
			     "Unexpected bridge state: %d for %s\n",
			     trans->bridge.state, vlr_subscr_name(trans->vsub));
			break;
		}
		break;

	case BRIDGE_STATE_BRIDGE_PENDING:
		trans->bridge.state = BRIDGE_STATE_BRIDGE_ESTABLISHED;
		break;

	default:
		LOGP(DMGCP, LOGL_ERROR,
		     "Unexpected bridge state: %d for %s\n",
		     trans->bridge.state, vlr_subscr_name(trans->vsub));
		break;
	}
}

int msc_call_bridge(struct gsm_trans *trans1, struct gsm_trans *trans2)
{
	/* First setup as loopback and configure the counterparts' endpoints,
	 * so that when transmission starts the originating addresses are
	 * already known to be valid. The mgcp callback will continue. */
	mgcp_bridge(trans1, trans2, BRIDGE_STATE_LOOPBACK_PENDING,
		    MGCP_CONN_LOOPBACK);
	mgcp_bridge(trans2, trans1, BRIDGE_STATE_LOOPBACK_PENDING,
		    MGCP_CONN_LOOPBACK);

	return 0;
}