summaryrefslogtreecommitdiffstats
path: root/openbsc/src/e1_input.c
blob: 2d0c1340fffa48c20b0c14cbdb0a270767b224e7 (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
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
/* OpenBSC Abis interface to E1 */

/* (C) 2008-2009 by Harald Welte <laforge@gnumonks.org>
 *
 * All Rights Reserved
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <time.h>
#include <sys/fcntl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <arpa/inet.h>
#include <mISDNif.h>

//#define AF_COMPATIBILITY_FUNC
//#include <compat_af_isdn.h>
#ifndef AF_ISDN
#define AF_ISDN 34
#define PF_ISDN AF_ISDN
#endif

#include <openbsc/select.h>
#include <openbsc/msgb.h>
#include <openbsc/debug.h>
#include <openbsc/gsm_data.h>
#include <openbsc/e1_input.h>
#include <openbsc/abis_nm.h>
#include <openbsc/abis_rsl.h>
#include <openbsc/linuxlist.h>
#include <openbsc/subchan_demux.h>
#include <openbsc/trau_frame.h>
#include <openbsc/trau_mux.h>
#include <openbsc/talloc.h>

#define NUM_E1_TS	32

/* list of all E1 drivers */
LLIST_HEAD(e1inp_driver_list);

/* list of all E1 lines */
LLIST_HEAD(e1inp_line_list);

static void *tall_sigl_ctx;

/* to be implemented, e.g. by bsc_hack.c */
void input_event(int event, enum e1inp_sign_type type, struct gsm_bts_trx *trx);

/*
 * pcap writing of the misdn load
 * pcap format is from http://wiki.wireshark.org/Development/LibpcapFileFormat
 */
#define DLT_LINUX_LAPD		177
#define PCAP_INPUT		0
#define PCAP_OUTPUT		1

struct pcap_hdr {
	u_int32_t magic_number;
	u_int16_t version_major;
	u_int16_t version_minor;
	int32_t  thiszone;
	u_int32_t sigfigs;
	u_int32_t snaplen;
	u_int32_t network;
} __attribute__((packed));

struct pcaprec_hdr {
	u_int32_t ts_sec;
	u_int32_t ts_usec;
	u_int32_t incl_len;
	u_int32_t orig_len;
} __attribute__((packed));

struct fake_linux_lapd_header {
        u_int16_t pkttype;
	u_int16_t hatype;
	u_int16_t halen;
	u_int64_t addr;
	int16_t protocol;
} __attribute__((packed));

struct lapd_header {
	u_int8_t ea1 : 1;
	u_int8_t cr : 1;
	u_int8_t sapi : 6;
	u_int8_t ea2 : 1;
	u_int8_t tei : 7;
	u_int8_t control_foo; /* fake UM's ... */
} __attribute__((packed));

static_assert((int)&((struct fake_linux_lapd_header*)NULL)->hatype == 2,	hatype_offset);
static_assert((int)&((struct fake_linux_lapd_header*)NULL)->halen == 4,		halen_offset);
static_assert((int)&((struct fake_linux_lapd_header*)NULL)->addr == 6,		addr_offset);
static_assert((int)&((struct fake_linux_lapd_header*)NULL)->protocol == 14,	proto_offset);
static_assert(sizeof(struct fake_linux_lapd_header) == 16,			lapd_header_size);


static int pcap_fd = -1;

void e1_set_pcap_fd(int fd)
{
	int ret;
	struct pcap_hdr header = {
		.magic_number	= 0xa1b2c3d4,
		.version_major	= 2,
		.version_minor	= 4,
		.thiszone	= 0,
		.sigfigs	= 0,
		.snaplen	= 65535,
		.network	= DLT_LINUX_LAPD,
	};

	pcap_fd = fd;
	ret = write(pcap_fd, &header, sizeof(header));
}

/* This currently only works for the D-Channel */
static void write_pcap_packet(int direction, int sapi, int tei,
			      struct msgb *msg) {
	if (pcap_fd < 0)
		return;

	int ret;
	time_t cur_time;
	struct tm *tm;
	int mi_head = (direction==PCAP_INPUT) ? MISDN_HEADER_LEN : 0;

	struct fake_linux_lapd_header header = {
		.pkttype	= 4,
		.hatype		= 0,
		.halen		= 0,
		.addr		= direction == PCAP_OUTPUT ? 0x0 : 0x1,
		.protocol	= ntohs(48),
	};

	struct lapd_header lapd_header = {
		.ea1		= 0,
		.cr		= direction == PCAP_OUTPUT ? 1 : 0,
		.sapi		= sapi & 0x3F,
		.ea2		= 1,
		.tei		= tei & 0x7F,
		.control_foo	= 0x03 /* UI */,
	};	

	struct pcaprec_hdr payload_header = {
		.ts_sec	    = 0,
		.ts_usec    = 0,
		.incl_len   = msg->len + sizeof(struct fake_linux_lapd_header)
				+ sizeof(struct lapd_header)
				- mi_head,
		.orig_len   = msg->len + sizeof(struct fake_linux_lapd_header)
				+ sizeof(struct lapd_header)
				- mi_head,
	};


        printf("Packet of: %d\n", direction);

	cur_time = time(NULL);
	tm = localtime(&cur_time);
	payload_header.ts_sec = mktime(tm);

	ret = write(pcap_fd, &payload_header, sizeof(payload_header));
	ret = write(pcap_fd, &header, sizeof(header));
	ret = write(pcap_fd, &lapd_header, sizeof(lapd_header));
	ret = write(pcap_fd, msg->data + mi_head,
			msg->len - mi_head);
}

static const char *sign_types[] = {
	[E1INP_SIGN_NONE]	= "None",
	[E1INP_SIGN_OML]	= "OML",
	[E1INP_SIGN_RSL]	= "RSL",
};
const char *e1inp_signtype_name(enum e1inp_sign_type tp)
{
	if (tp >= ARRAY_SIZE(sign_types))
		return "undefined";
	return sign_types[tp];
}

static const char *ts_types[] = {
	[E1INP_TS_TYPE_NONE]	= "None",
	[E1INP_TS_TYPE_SIGN]	= "Signalling",
	[E1INP_TS_TYPE_TRAU]	= "TRAU",
};

const char *e1inp_tstype_name(enum e1inp_ts_type tp)
{
	if (tp >= ARRAY_SIZE(ts_types))
		return "undefined";
	return ts_types[tp];
}

/* callback when a TRAU frame was received */
static int subch_cb(struct subch_demux *dmx, int ch, u_int8_t *data, int len,
		    void *_priv)
{
	struct e1inp_ts *e1i_ts = _priv;
	struct gsm_e1_subslot src_ss;

	src_ss.e1_nr = e1i_ts->line->num;
	src_ss.e1_ts = e1i_ts->num;
	src_ss.e1_ts_ss = ch;

	return trau_mux_input(&src_ss, data, len);
}

int abis_rsl_sendmsg(struct msgb *msg)
{
	struct e1inp_sign_link *sign_link;
	struct e1inp_driver *e1inp_driver;
	struct e1inp_ts *e1i_ts;

	msg->l2h = msg->data;

	if (!msg->trx || !msg->trx->rsl_link) {
		fprintf(stderr, "rsl_sendmsg: msg->trx == NULL\n");
		talloc_free(msg);
		return -EINVAL;
	}

	sign_link = msg->trx->rsl_link;
	e1i_ts = sign_link->ts;
	if (!bsc_timer_pending(&e1i_ts->sign.tx_timer)) {
		/* notify the driver we have something to write */
		e1inp_driver = sign_link->ts->line->driver;
		e1inp_driver->want_write(e1i_ts);
	}
	msgb_enqueue(&sign_link->tx_list, msg);

	/* dump it */
	write_pcap_packet(PCAP_OUTPUT, sign_link->sapi, sign_link->tei, msg);

	return 0;
}

int _abis_nm_sendmsg(struct msgb *msg)
{
	struct e1inp_sign_link *sign_link;
	struct e1inp_driver *e1inp_driver;
	struct e1inp_ts *e1i_ts;

	msg->l2h = msg->data;

	if (!msg->trx || !msg->trx->bts || !msg->trx->bts->oml_link) {
		fprintf(stderr, "nm_sendmsg: msg->trx == NULL\n");
		return -EINVAL;
	}

	sign_link = msg->trx->bts->oml_link;
	e1i_ts = sign_link->ts;
	if (!bsc_timer_pending(&e1i_ts->sign.tx_timer)) {
		/* notify the driver we have something to write */
		e1inp_driver = sign_link->ts->line->driver;
		e1inp_driver->want_write(e1i_ts);
	}
	msgb_enqueue(&sign_link->tx_list, msg);

	/* dump it */
	write_pcap_packet(PCAP_OUTPUT, sign_link->sapi, sign_link->tei, msg);

	return 0;
}

/* Timeslot */

/* configure and initialize one e1inp_ts */
int e1inp_ts_config(struct e1inp_ts *ts, struct e1inp_line *line,
		    enum e1inp_ts_type type)
{
	ts->type = type;
	ts->line = line;

	switch (type) {
	case E1INP_TS_TYPE_SIGN:
		INIT_LLIST_HEAD(&ts->sign.sign_links);
		break;
	case E1INP_TS_TYPE_TRAU:
		subchan_mux_init(&ts->trau.mux);
		ts->trau.demux.out_cb = subch_cb;
		ts->trau.demux.data = ts;
		subch_demux_init(&ts->trau.demux);
		break;
	default:
		fprintf(stderr, "unsupported E1 timeslot type %u\n",
			ts->type);
		return -EINVAL;
	}
	return 0;
}

static struct e1inp_line *e1inp_line_get(u_int8_t e1_nr)
{
	struct e1inp_line *e1i_line;

	/* iterate over global list of e1 lines */
	llist_for_each_entry(e1i_line, &e1inp_line_list, list) {
		if (e1i_line->num == e1_nr)
			return e1i_line;
	}
	return NULL;
}

static struct e1inp_ts *e1inp_ts_get(u_int8_t e1_nr, u_int8_t ts_nr)
{
	struct e1inp_line *e1i_line;

	e1i_line = e1inp_line_get(e1_nr);
	if (!e1i_line)
		return NULL;

	return &e1i_line->ts[ts_nr-1];
}

struct subch_mux *e1inp_get_mux(u_int8_t e1_nr, u_int8_t ts_nr)
{
	struct e1inp_ts *e1i_ts = e1inp_ts_get(e1_nr, ts_nr);

	if (!e1i_ts)
		return NULL;

	return &e1i_ts->trau.mux;
}

/* Signalling Link */

struct e1inp_sign_link *e1inp_lookup_sign_link(struct e1inp_ts *e1i,
					 	u_int8_t tei, u_int8_t sapi)
{
	struct e1inp_sign_link *link;

	llist_for_each_entry(link, &e1i->sign.sign_links, list) {
		if (link->sapi == sapi && link->tei == tei)
			return link;
	}

	return NULL;
}

/* create a new signalling link in a E1 timeslot */

struct e1inp_sign_link *
e1inp_sign_link_create(struct e1inp_ts *ts, enum e1inp_sign_type type,
			struct gsm_bts_trx *trx, u_int8_t tei,
			u_int8_t sapi)
{
	struct e1inp_sign_link *link;

	if (ts->type != E1INP_TS_TYPE_SIGN)
		return NULL;

	if (!tall_sigl_ctx)
		tall_sigl_ctx = talloc_named_const(tall_bsc_ctx, 1,
						   "e1inp_sign_link");

	link = talloc_zero(tall_sigl_ctx, struct e1inp_sign_link);
	if (!link)
		return NULL;

	link->ts = ts;
	link->type = type;
	INIT_LLIST_HEAD(&link->tx_list);
	link->trx = trx;
	link->tei = tei;
	link->sapi = sapi;

	llist_add_tail(&link->list, &ts->sign.sign_links);

	return link;
}

/* the E1 driver tells us he has received something on a TS */
int e1inp_rx_ts(struct e1inp_ts *ts, struct msgb *msg,
		u_int8_t tei, u_int8_t sapi)
{
	struct e1inp_sign_link *link;
	int ret;

	switch (ts->type) {
	case E1INP_TS_TYPE_SIGN:
		/* consult the list of signalling links */
		write_pcap_packet(PCAP_INPUT, sapi, tei, msg);
		link = e1inp_lookup_sign_link(ts, tei, sapi);
		if (!link) {
			fprintf(stderr, "didn't find singalling link for "
				"tei %d, sapi %d\n", tei, sapi);
			return -EINVAL;
		}
		switch (link->type) {
		case E1INP_SIGN_OML:
			msg->trx = link->trx;
			ret = abis_nm_rcvmsg(msg);
			break;
		case E1INP_SIGN_RSL:
			msg->trx = link->trx;
			ret = abis_rsl_rcvmsg(msg);
			break;
		default:
			ret = -EINVAL;
			fprintf(stderr, "unknown link type %u\n", link->type);
			break;
		}
		break;
	case E1INP_TS_TYPE_TRAU:
		ret = subch_demux_in(&ts->trau.demux, msg->l2h, msgb_l2len(msg));
		break;
	default:
		ret = -EINVAL;
		fprintf(stderr, "unknown TS type %u\n", ts->type);
		break;
	}

	return ret;
}

#define TSX_ALLOC_SIZE 4096

/* called by driver if it wants to transmit on a given TS */
struct msgb *e1inp_tx_ts(struct e1inp_ts *e1i_ts,
			 struct e1inp_sign_link **sign_link)
{
	struct e1inp_sign_link *link;
	struct msgb *msg = NULL;
	int len;

	switch (e1i_ts->type) {
	case E1INP_TS_TYPE_SIGN:
		/* FIXME: implement this round robin */
		llist_for_each_entry(link, &e1i_ts->sign.sign_links, list) {
			msg = msgb_dequeue(&link->tx_list);
			if (msg) {
				if (sign_link)
					*sign_link = link;
				break;
			}
		}
		break;
	case E1INP_TS_TYPE_TRAU:
		msg = msgb_alloc(TSX_ALLOC_SIZE, "TRAU_TX");
		if (!msg)
			return NULL;
		len = subchan_mux_out(&e1i_ts->trau.mux, msg->data, 40);
		msgb_put(msg, 40);
		break;
	default:
		fprintf(stderr, "unsupported E1 TS type %u\n", e1i_ts->type);
		return NULL;
	}
	return msg;
}

/* called by driver in case some kind of link state event */
int e1inp_event(struct e1inp_ts *ts, int evt, u_int8_t tei, u_int8_t sapi)
{
	struct e1inp_sign_link *link;

	link = e1inp_lookup_sign_link(ts, tei, sapi);
	if (!link)
		return -EINVAL;

	/* FIXME: report further upwards */
	input_event(evt, link->type, link->trx);
	return 0;
}

/* register a driver with the E1 core */
int e1inp_driver_register(struct e1inp_driver *drv)
{
	llist_add_tail(&drv->list, &e1inp_driver_list);
	return 0;
}

/* register a line with the E1 core */
int e1inp_line_register(struct e1inp_line *line)
{
	int i;

	for (i = 0; i < NUM_E1_TS; i++) {
		line->ts[i].num = i+1;
		line->ts[i].line = line;
	}

	llist_add_tail(&line->list, &e1inp_line_list);
	
	return 0;
}