aboutsummaryrefslogtreecommitdiffstats
path: root/openbsc/src/gprs/sgsn_iu.c
blob: 7b8eb0e5deb82bcc9a171364c92154e13c568f41 (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
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
#include <stdint.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include <osmocom/core/select.h>
#include <osmocom/core/prim.h>
#include <osmocom/core/talloc.h>
#include <osmocom/core/logging.h>
#include <osmocom/core/application.h>
#include <osmocom/vty/logging.h>

#include <osmocom/gsm/gsm48.h>
#include <osmocom/gprs/gprs_msgb.h>

#include <osmocom/sigtran/sua.h>
#include <osmocom/sigtran/sccp_sap.h>

#include <openbsc/gprs_sgsn.h>
#include <openbsc/debug.h>

#include <osmocom/ranap/ranap_ies_defs.h>
#include <osmocom/ranap/ranap_common_cn.h>

int asn1_xer_print = 1;
void *talloc_asn1_ctx;

struct ue_conn_ctx {
	struct llist_head list;
	struct osmo_sua_link *link;
	uint32_t conn_id;
};

static LLIST_HEAD(conn_ctx_list);

struct ue_conn_ctx *ue_conn_ctx_alloc(struct osmo_sua_link *link, uint32_t conn_id)
{
	struct ue_conn_ctx *ctx = talloc_zero(NULL, struct ue_conn_ctx);

	ctx->link = link;
	ctx->conn_id = conn_id;
	llist_add(&ctx->list, &conn_ctx_list);

	return ctx;
}

struct ue_conn_ctx *ue_conn_ctx_find(struct osmo_sua_link *link, uint32_t conn_id)
{
	struct ue_conn_ctx *ctx;

	llist_for_each_entry(ctx, &conn_ctx_list, list) {
		if (ctx->link == link && ctx->conn_id == conn_id)
			return ctx;
	}
	return NULL;
}

/***********************************************************************
 * RANAP handling
 ***********************************************************************/

int gprs_iu_rab_act(struct sgsn_mm_ctx *mm, uint32_t gtp_ip, uint32_t gtp_tei)
{
	struct ue_conn_ctx *uectx;
	struct osmo_scu_prim *prim;
	struct msgb *msg;

	uectx = mm->iu.ue_ctx;

	msg = ranap_new_msg_rab_assign_data(1, gtp_ip, gtp_tei);
	msg->l2h = msg->data;

	/* wrap RANAP message in SCCP N-DATA.req */
	prim = (struct osmo_scu_prim *) msgb_push(msg, sizeof(*prim));
	prim->u.data.conn_id = uectx->conn_id;
	osmo_prim_init(&prim->oph, SCCP_SAP_USER,
			OSMO_SCU_PRIM_N_DATA,
			PRIM_OP_REQUEST, msg);
	osmo_sua_user_link_down(uectx->link, &prim->oph);
}

int gprs_iu_rab_deact(struct sgsn_mm_ctx *mm)
{

}

int gprs_transp_upd_key(struct sgsn_mm_ctx *mm)
{
	struct gsm_auth_tuple *tp = &mm->auth_triplet;

	if (mm->ran_type == MM_CTX_T_UTRAN_Iu) {
		struct ue_conn_ctx *uectx;
		struct osmo_scu_prim *prim;
		struct msgb *msg;
		uint8_t ik[16];
		uint8_t ck[16];
		unsigned int i;

		uectx = mm->iu.ue_ctx;

		/* C4 function to dervie CK from Kc */
		memcpy(ck, tp->kc, 8);
		memcpy(ck+8, tp->kc, 8);

		/* C5 function to derive IK from Kc */
		for (i = 0; i < 4; i++)
			ik[i] = tp->kc[i] ^ tp->kc[i+4];
		memcpy(ik+4, tp->kc, 8);
		for (i = 12; i < 16; i++)
			ik[i] = ik[i-12];

		/* crate RANAP message */
		msg = ranap_new_msg_sec_mod_cmd(ik, NULL);
		msg->l2h = msg->data;
		/* wrap RANAP message in SCCP N-DATA.req */
		prim = (struct osmo_scu_prim *) msgb_push(msg, sizeof(*prim));
		prim->u.data.conn_id = uectx->conn_id;
		osmo_prim_init(&prim->oph, SCCP_SAP_USER,
				OSMO_SCU_PRIM_N_DATA,
				PRIM_OP_REQUEST, msg);
		osmo_sua_user_link_down(uectx->link, &prim->oph);
	}

	return 0;
}

static int ranap_handle_co_initial_ue(void *ctx, RANAP_InitialUE_MessageIEs_t *ies)
{
	struct gprs_ra_id ra_id;
	uint16_t sai;
	struct msgb *msg = msgb_alloc(256, "RANAP->NAS");

	ranap_parse_lai(&ra_id, &ies->lai);
	sai = asn1str_to_u16(&ies->sai.sAC);
	msgb_gmmh(msg) = msgb_put(msg, ies->nas_pdu.size);
	memcpy(msgb_gmmh(msg), ies->nas_pdu.buf, ies->nas_pdu.size);

	/* Feed into the MM layer */
	msg->dst = ctx;
	gsm0408_gprs_rcvmsg_iu(msg, ra_id, sai);

	return 0;
}

static int ranap_handle_co_dt(void *ctx, RANAP_DirectTransferIEs_t *ies)
{
	struct gprs_ra_id _ra_id, *ra_id = NULL;
	uint16_t _sai, *sai = NULL;
	struct msgb *msg = msgb_alloc(256, "RANAP->NAS");

	if (ies->presenceMask & DIRECTTRANSFERIES_RANAP_LAI_PRESENT) {
		ranap_parse_lai(&_ra_id, &ies->lai);
		ra_id = &_ra_id;
		if (ies->presenceMask & DIRECTTRANSFERIES_RANAP_RAC_PRESENT) {
			_ra_id.rac = asn1str_to_u8(&ies->rac);
		}
		if (ies->presenceMask & DIRECTTRANSFERIES_RANAP_SAI_PRESENT) {
			_sai = asn1str_to_u16(&ies->sai.sAC);
			sai = &_sai;
		}
	}

	msgb_gmmh(msg) = msgb_put(msg, ies->nas_pdu.size);
	memcpy(msgb_gmmh(msg), ies->nas_pdu.buf, ies->nas_pdu.size);

	/* Feed into the MM/CC/SMS-CP layer */
	msg->dst = ctx;
	gsm0408_gprs_rcvmsg_iu(msg, ra_id, sai);

	return 0;
}

static int ranap_handle_co_err_ind(void *ctx, RANAP_ErrorIndicationIEs_t *ies)
{
	if (ies->presenceMask & ERRORINDICATIONIES_RANAP_CAUSE_PRESENT)
		LOGP(DRANAP, LOGL_ERROR, "Rx Error Indication (%s)\n",
			ranap_cause_str(&ies->cause));
	else
		LOGP(DRANAP, LOGL_ERROR, "Rx Error Indication\n");

	return 0;
}

int gprs_iu_tx(struct msgb *msg, uint8_t sapi, struct mm_context *mm)
{
	struct ue_conn_ctx *uectx = msg->dst;
	struct osmo_scu_prim *prim;

	LOGP(DRANAP, LOGL_INFO, "Transmitting L3 Message as RANAP DT\n");

	msg = ranap_new_msg_dt(sapi, msg->data, msgb_length(msg));
	msg->l2h = msg->data;
	prim = (struct osmo_scu_prim *) msgb_push(msg, sizeof(*prim));
	prim->u.data.conn_id = uectx->conn_id;
	osmo_prim_init(&prim->oph, SCCP_SAP_USER,
			OSMO_SCU_PRIM_N_DATA,
			PRIM_OP_REQUEST, msg);
	osmo_sua_user_link_down(uectx->link, &prim->oph);
	return 0;
}

static int ranap_handle_co_iu_rel_req(struct ue_conn_ctx *ctx, RANAP_Iu_ReleaseRequestIEs_t *ies)
{
	struct msgb *msg;
	struct osmo_scu_prim *prim;

	LOGP(DRANAP, LOGL_INFO, "Received Iu Release Request, Sending Release Command\n");
	msg = ranap_new_msg_iu_rel_cmd(&ies->cause);
	msg->l2h = msg->data;
	prim = (struct osmo_scu_prim *) msgb_push(msg, sizeof(*prim));
	prim->u.data.conn_id = ctx->conn_id;
	osmo_prim_init(&prim->oph, SCCP_SAP_USER,
			OSMO_SCU_PRIM_N_DATA,
			PRIM_OP_REQUEST, msg);
	osmo_sua_user_link_down(ctx->link, &prim->oph);
	return 0;
}

static int ranap_handle_co_rab_ass_resp(void *ctx, RANAP_RAB_AssignmentResponseIEs_t *ies)
{
	int i, rc;

	LOGP(DRANAP, LOGL_INFO, "RAB Asignment Response:");
	if (ies->presenceMask & RAB_ASSIGNMENTRESPONSEIES_RANAP_RAB_SETUPORMODIFIEDLIST_PRESENT) {
		RANAP_RAB_SetupOrModifiedItemIEs_t setup_ies;
		RANAP_RAB_SetupOrModifiedItem_t *item = &setup_ies.raB_SetupOrModifiedItem;
		rc = ranap_decode_rab_setupormodifieditemies(&setup_ies, &ies->raB_SetupOrModifiedList);
		if (item->transportLayerAddress) {
			uint8_t rab_id = item->rAB_ID.buf[0];
			LOGPC(DRANAP, LOGL_INFO, " Setup: (%u/%s)", osmo_hexdump(item->transportLayerAddress->buf,
									     item->transportLayerAddress->size));
		}
	}

	LOGPC(DRANAP, LOGL_INFO, "\n");

	return rc;
}

/* Entry point for connection-oriented ANAP message */
static void cn_ranap_handle_co(void *ctx, ranap_message *message)
{
	int rc = 0;

	LOGP(DRANAP, LOGL_NOTICE, "handle_co(dir=%u, proc=%u)\n", message->direction, message->procedureCode);

	switch (message->direction) {
	case RANAP_RANAP_PDU_PR_initiatingMessage:
		switch (message->procedureCode) {
		case RANAP_ProcedureCode_id_InitialUE_Message:
			rc = ranap_handle_co_initial_ue(ctx, &message->msg.initialUE_MessageIEs);
			break;
		case RANAP_ProcedureCode_id_DirectTransfer:
			rc = ranap_handle_co_dt(ctx, &message->msg.directTransferIEs);
			break;
		case RANAP_ProcedureCode_id_ErrorIndication:
			rc = ranap_handle_co_err_ind(ctx, &message->msg.errorIndicationIEs);
			break;
		case RANAP_ProcedureCode_id_Iu_ReleaseRequest:
			/* Iu Release Request */
			rc = ranap_handle_co_iu_rel_req(ctx, &message->msg.iu_ReleaseRequestIEs);
			break;
		}
		break;
	case RANAP_RANAP_PDU_PR_successfulOutcome:
		switch (message->procedureCode) {
		case RANAP_ProcedureCode_id_RAB_Assignment:
			/* RAB Assignment Response */
			rc = ranap_handle_co_rab_ass_resp(ctx, &message->msg.raB_AssignmentResponseIEs);
			break;
		case RANAP_ProcedureCode_id_SecurityModeControl:
			/* Security Mode Complete */
			break;
		case RANAP_ProcedureCode_id_Iu_Release:
			/* Iu Release Complete */
			break;
		}
	case RANAP_RANAP_PDU_PR_unsuccessfulOutcome:
	case RANAP_RANAP_PDU_PR_outcome:
	default:
		rc = -1;
		break;
	}
}

static int ranap_handle_cl_reset_req(void *ctx, RANAP_ResetIEs_t *ies)
{
	/* FIXME: send reset response */
}

static int ranap_handle_cl_err_ind(void *ctx, RANAP_ErrorIndicationIEs_t *ies)
{
	if (ies->presenceMask & ERRORINDICATIONIES_RANAP_CAUSE_PRESENT)
		LOGP(DRANAP, LOGL_ERROR, "Rx Error Indication (%s)\n",
			ranap_cause_str(&ies->cause));
	else
		LOGP(DRANAP, LOGL_ERROR, "Rx Error Indication\n");

	return 0;
}

/* Entry point for connection-less RANAP message */
static void cn_ranap_handle_cl(void *ctx, ranap_message *message)
{
	int rc = 0;

	switch (message->direction) {
	case RANAP_RANAP_PDU_PR_initiatingMessage:
		switch (message->procedureCode) {
		case RANAP_ProcedureCode_id_Reset:
			/* received reset.req, send reset.resp */
			rc = ranap_handle_cl_reset_req(ctx, &message->msg.resetIEs);
			break;
		case RANAP_ProcedureCode_id_ErrorIndication:
			rc = ranap_handle_cl_err_ind(ctx, &message->msg.errorIndicationIEs);
			break;
		}
		break;
	case RANAP_RANAP_PDU_PR_successfulOutcome:
	case RANAP_RANAP_PDU_PR_unsuccessfulOutcome:
	case RANAP_RANAP_PDU_PR_outcome:
	default:
		rc = -1;
		break;
	}
}

/***********************************************************************
 *
 ***********************************************************************/

int tx_unitdata(struct osmo_sua_link *link);
int tx_conn_req(struct osmo_sua_link *link, uint32_t conn_id);

struct osmo_prim_hdr *make_conn_req(uint32_t conn_id);
struct osmo_prim_hdr *make_dt1_req(uint32_t conn_id, const uint8_t *data, unsigned int len);

struct osmo_prim_hdr *make_conn_resp(struct osmo_scu_connect_param *param)
{
	struct msgb *msg = msgb_alloc(1024, "conn_resp");
	struct osmo_scu_prim *prim;

	prim = (struct osmo_scu_prim *) msgb_put(msg, sizeof(*prim));
	osmo_prim_init(&prim->oph, SCCP_SAP_USER,
			OSMO_SCU_PRIM_N_CONNECT,
			PRIM_OP_RESPONSE, msg);
	memcpy(&prim->u.connect, param, sizeof(prim->u.connect));
	return &prim->oph;
}

static int sccp_sap_up(struct osmo_prim_hdr *oph, void *link)
{
	struct osmo_scu_prim *prim = (struct osmo_scu_prim *) oph;
	struct osmo_prim_hdr *resp = NULL;
	const uint8_t payload[] = { 0xb1, 0xb2, 0xb3 };
	int rc;
	struct ue_conn_ctx *ue;

	printf("sccp_sap_up(%s)\n", osmo_scu_prim_name(oph));

	switch (OSMO_PRIM_HDR(oph)) {
	case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_CONFIRM):
		/* confirmation of outbound connection */
		break;
	case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_INDICATION):
		/* indication of new inbound connection request*/
		printf("N-CONNECT.ind(X->%u)\n", prim->u.connect.conn_id);
		if (/*  prim->u.connect.called_addr.ssn != OSMO_SCCP_SSN_RANAP || */
		    !msgb_l2(oph->msg) || msgb_l2len(oph->msg) == 0) {
			LOGP(DGPRS, LOGL_NOTICE, "Received invalid N-CONNECT.ind\n");
			return 0;
		}
		/* FIXME: allocate UE context */
		ue = ue_conn_ctx_alloc(link, prim->u.connect.conn_id);
		/* first ensure the local SUA/SCCP socket is ACTIVE */
		resp = make_conn_resp(&prim->u.connect);
		osmo_sua_user_link_down(link, resp);
		/* then handle the RANAP payload */
		rc = ranap_cn_rx_co(cn_ranap_handle_co, ue, msgb_l2(oph->msg), msgb_l2len(oph->msg));
		break;
	case OSMO_PRIM(OSMO_SCU_PRIM_N_DISCONNECT, PRIM_OP_INDICATION):
		/* indication of disconnect */
		printf("N-DISCONNECT.ind(%u)\n", prim->u.disconnect.conn_id);
		ue = ue_conn_ctx_find(link, prim->u.disconnect.conn_id);
		rc = ranap_cn_rx_co(cn_ranap_handle_co, ue, msgb_l2(oph->msg), msgb_l2len(oph->msg));
		break;
	case OSMO_PRIM(OSMO_SCU_PRIM_N_DATA, PRIM_OP_INDICATION):
		/* connection-oriented data received */
		printf("N-DATA.ind(%u, %s)\n", prim->u.data.conn_id,
			osmo_hexdump(msgb_l2(oph->msg), msgb_l2len(oph->msg)));
		/* resolve UE context */
		ue = ue_conn_ctx_find(link, prim->u.data.conn_id);
		rc = ranap_cn_rx_co(cn_ranap_handle_co, ue, msgb_l2(oph->msg), msgb_l2len(oph->msg));
		break;
	case OSMO_PRIM(OSMO_SCU_PRIM_N_UNITDATA, PRIM_OP_INDICATION):
		/* connection-oriented data received */
		printf("N-UNITDATA.ind(%s)\n", 
			osmo_hexdump(msgb_l2(oph->msg), msgb_l2len(oph->msg)));
		rc = ranap_cn_rx_cl(cn_ranap_handle_cl, link, msgb_l2(oph->msg), msgb_l2len(oph->msg));
		break;
	}

	msgb_free(oph->msg);
	return 0;
}

int sgsn_iu_init(void *ctx)
{
	struct osmo_sua_user *user;
	int rc;

	talloc_asn1_ctx = talloc_named_const(ctx, 1, "asn1");

	osmo_sua_set_log_area(DSUA);

	user = osmo_sua_user_create(ctx, sccp_sap_up, ctx);

	rc = osmo_sua_server_listen(user, "127.0.0.2", 14001);
	if (rc < 0) {
		exit(1);
	}
}