summaryrefslogtreecommitdiffstats
path: root/src/gsm/ipa.c
blob: fa6a8b0d9c6ea4a27abf021c682855cf92d9e19f (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
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
/* OpenBSC Abis input driver for ip.access */

/* (C) 2009-2017 by Harald Welte <laforge@gnumonks.org>
 * (C) 2010 by Holger Hans Peter Freyther
 * (C) 2010 by On-Waves
 *
 * 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, see <http://www.gnu.org/licenses/>.
 *
 */

#include "config.h"

#include <unistd.h>
#include <stdint.h>
#include <errno.h>
#include <stdlib.h>

#include <sys/types.h>

#include <osmocom/core/byteswap.h>
#include <osmocom/core/msgb.h>
#include <osmocom/core/talloc.h>
#include <osmocom/core/logging.h>
#include <osmocom/core/macaddr.h>
#include <osmocom/core/select.h>

#include <osmocom/gsm/tlv.h>
#include <osmocom/gsm/protocol/ipaccess.h>
#include <osmocom/gsm/ipa.h>

#define IPA_ALLOC_SIZE 1200

/*
 * Common propietary IPA messages:
 *      - PONG: in reply to PING.
 *      - ID_REQUEST: first messages once OML has been established.
 *      - ID_ACK: in reply to ID_ACK.
 */
static const uint8_t ipa_pong_msg[] = {
	0, 1, IPAC_PROTO_IPACCESS, IPAC_MSGT_PONG
};

static const uint8_t ipa_id_ack_msg[] = {
	0, 1, IPAC_PROTO_IPACCESS, IPAC_MSGT_ID_ACK
};

static const uint8_t ipa_id_req_msg[] = {
	0, 17, IPAC_PROTO_IPACCESS, IPAC_MSGT_ID_GET,
	0x01, IPAC_IDTAG_UNIT,
	0x01, IPAC_IDTAG_MACADDR,
	0x01, IPAC_IDTAG_LOCATION1,
	0x01, IPAC_IDTAG_LOCATION2,
	0x01, IPAC_IDTAG_EQUIPVERS,
	0x01, IPAC_IDTAG_SWVERSION,
	0x01, IPAC_IDTAG_UNITNAME,
	0x01, IPAC_IDTAG_SERNR,
};


static const char *idtag_names[] = {
	[IPAC_IDTAG_SERNR]	= "Serial_Number",
	[IPAC_IDTAG_UNITNAME]	= "Unit_Name",
	[IPAC_IDTAG_LOCATION1]	= "Location_1",
	[IPAC_IDTAG_LOCATION2]	= "Location_2",
	[IPAC_IDTAG_EQUIPVERS]	= "Equipment_Version",
	[IPAC_IDTAG_SWVERSION]	= "Software_Version",
	[IPAC_IDTAG_IPADDR]	= "IP_Address",
	[IPAC_IDTAG_MACADDR]	= "MAC_Address",
	[IPAC_IDTAG_UNIT]	= "Unit_ID",
};

const char *ipa_ccm_idtag_name(uint8_t tag)
{
	if (tag >= ARRAY_SIZE(idtag_names))
		return "unknown";

	return idtag_names[tag];
}

int ipa_ccm_idtag_parse(struct tlv_parsed *dec, unsigned char *buf, int len)
{
	return ipa_ccm_idtag_parse_off(dec, buf, len, 0);
}

int ipa_ccm_idtag_parse_off(struct tlv_parsed *dec, unsigned char *buf, int len, const int len_offset)
{
	uint8_t t_len;
	uint8_t t_tag;
	uint8_t *cur = buf;

	memset(dec, 0, sizeof(*dec));

	while (len >= 2) {
		len -= 2;
		t_len = *cur++;
		t_tag = *cur++;

		if (t_len < len_offset) {
			LOGP(DLMI, LOGL_ERROR, "minimal offset not included: %d < %d\n", t_len, len_offset);
			return -EINVAL;
		}

		if (t_len > len + 1) {
			LOGP(DLMI, LOGL_ERROR, "The tag does not fit: %d > %d\n", t_len, len + 1);
			return -EINVAL;
		}

		DEBUGPC(DLMI, "%s='%s' ", ipa_ccm_idtag_name(t_tag), cur);

		dec->lv[t_tag].len = t_len - len_offset;
		dec->lv[t_tag].val = cur;

		cur += t_len - len_offset;
		len -= t_len - len_offset;
	}
	return 0;
}

int ipa_parse_unitid(const char *str, struct ipaccess_unit *unit_data)
{
	unsigned long ul;
	char *endptr;
	const char *nptr;

	nptr = str;
	ul = strtoul(nptr, &endptr, 10);
	if (endptr <= nptr)
		return -EINVAL;
	unit_data->site_id = ul & 0xffff;

	if (*endptr++ != '/')
		return -EINVAL;

	nptr = endptr;
	ul = strtoul(nptr, &endptr, 10);
	if (endptr <= nptr)
		return -EINVAL;
	unit_data->bts_id = ul & 0xffff;

	if (*endptr++ != '/')
		return -EINVAL;

	nptr = endptr;
	ul = strtoul(nptr, &endptr, 10);
	if (endptr <= nptr)
		return -EINVAL;
	unit_data->trx_id = ul & 0xffff;

	return 0;
}

int ipa_ccm_tlv_to_unitdata(struct ipaccess_unit *ud,
			     const struct tlv_parsed *tp)
{
	int rc = 0;

	if (TLVP_PRES_LEN(tp, IPAC_IDTAG_SERNR, 1))
		ud->serno = talloc_strdup(ud, (char *)
					TLVP_VAL(tp, IPAC_IDTAG_SERNR));

	if (TLVP_PRES_LEN(tp, IPAC_IDTAG_UNITNAME, 1))
		ud->unit_name = talloc_strdup(ud, (char *)
					TLVP_VAL(tp, IPAC_IDTAG_UNITNAME));

	if (TLVP_PRES_LEN(tp, IPAC_IDTAG_LOCATION1, 1))
		ud->location1 = talloc_strdup(ud, (char *)
					TLVP_VAL(tp, IPAC_IDTAG_LOCATION1));

	if (TLVP_PRES_LEN(tp, IPAC_IDTAG_LOCATION2, 1))
		ud->location2 = talloc_strdup(ud, (char *)
					TLVP_VAL(tp, IPAC_IDTAG_LOCATION2));

	if (TLVP_PRES_LEN(tp, IPAC_IDTAG_EQUIPVERS, 1))
		ud->equipvers = talloc_strdup(ud, (char *)
					TLVP_VAL(tp, IPAC_IDTAG_EQUIPVERS));

	if (TLVP_PRES_LEN(tp, IPAC_IDTAG_SWVERSION, 1))
		ud->swversion = talloc_strdup(ud, (char *)
					TLVP_VAL(tp, IPAC_IDTAG_SWVERSION));

	if (TLVP_PRES_LEN(tp, IPAC_IDTAG_MACADDR, 17)) {
		rc = osmo_macaddr_parse(ud->mac_addr, (char *)
					TLVP_VAL(tp, IPAC_IDTAG_MACADDR));
		if (rc < 0)
			goto out;
	}

	if (TLVP_PRES_LEN(tp, IPAC_IDTAG_UNIT, 1))
		rc = ipa_parse_unitid((char *)
					TLVP_VAL(tp, IPAC_IDTAG_UNIT), ud);

out:
	return rc;
}

#define IPA_STRING_MAX 64

/*! \brief Generate IPA CCM ID RESP based on list of IEs
 *  \param[in] dev Descriptor describing identity data for response
 *  \param[in] ies_req List of IEIs to include in response
 *  \param[in] num_ies_req Number of IEIs in \a ies_req
 *  \returns Message buffer with IPA CCM ID RESP */
struct msgb *ipa_ccm_make_id_resp(const struct ipaccess_unit *dev,
				  const uint8_t *ies_req, unsigned int num_ies_req)
{
	struct msgb *msg = ipa_msg_alloc(16);
	char str[IPA_STRING_MAX];
	unsigned int i;

	if (!msg)
		return NULL;

	*msgb_put(msg, 1) = IPAC_MSGT_ID_RESP;

	for (i = 0; i < num_ies_req; i++) {
		uint8_t *tag;

		str[0] = '\0';
		switch (ies_req[i]) {
		case IPAC_IDTAG_UNIT:
			snprintf(str, sizeof(str), "%u/%u/%u",
				dev->site_id, dev->bts_id, dev->trx_id);
			break;
		case IPAC_IDTAG_MACADDR:
			snprintf(str, sizeof(str),
				 "%02x:%02x:%02x:%02x:%02x:%02x",
				 dev->mac_addr[0], dev->mac_addr[1],
				 dev->mac_addr[2], dev->mac_addr[3],
				 dev->mac_addr[4], dev->mac_addr[5]);
			break;
		case IPAC_IDTAG_LOCATION1:
			if (dev->location1)
				strncpy(str, dev->location1, IPA_STRING_MAX);
			break;
		case IPAC_IDTAG_LOCATION2:
			if (dev->location2)
				strncpy(str, dev->location2, IPA_STRING_MAX);
			break;
		case IPAC_IDTAG_EQUIPVERS:
			if (dev->equipvers)
				strncpy(str, dev->equipvers, IPA_STRING_MAX);
			break;
		case IPAC_IDTAG_SWVERSION:
			if (dev->swversion)
				strncpy(str, dev->swversion, IPA_STRING_MAX);
			break;
		case IPAC_IDTAG_UNITNAME:
			if (dev->unit_name) {
				snprintf(str, sizeof(str), dev->unit_name, IPA_STRING_MAX);
			} else {
				snprintf(str, sizeof(str),
					 "%02x-%02x-%02x-%02x-%02x-%02x",
					 dev->mac_addr[0], dev->mac_addr[1],
					 dev->mac_addr[2], dev->mac_addr[3],
					 dev->mac_addr[4], dev->mac_addr[5]);
			}
			break;
		case IPAC_IDTAG_SERNR:
			if (dev->serno)
				strncpy(str, dev->serno, IPA_STRING_MAX);
			break;
		default:
			LOGP(DLINP, LOGL_NOTICE,
				"Unknown ipaccess tag 0x%02x\n", ies_req[i]);
			msgb_free(msg);
			return NULL;
		}
		str[IPA_STRING_MAX-1] = '\0';

		LOGP(DLINP, LOGL_INFO, " tag %d: %s\n", ies_req[i], str);
		tag = msgb_put(msg, 3 + strlen(str) + 1);
		tag[0] = 0x00;
		tag[1] = 1 + strlen(str) + 1;
		tag[2] = ies_req[1];
		memcpy(tag + 3, str, strlen(str) + 1);
	}
	ipa_prepend_header(msg, IPAC_PROTO_IPACCESS);
	return msg;
}

/*! \brief Generate IPA CCM ID RESP based on requets payload
 *  \param[in] dev Descriptor describing identity data for response
 *  \param[in] data Payload of the IPA CCM ID GET request
 *  \param[in] len Length of \a data in octets
 *  \returns Message buffer with IPA CCM ID RESP */
struct msgb *ipa_ccm_make_id_resp_from_req(const struct ipaccess_unit *dev,
					   const uint8_t *data, unsigned int len)
{
	uint8_t ies[len/2];
	unsigned int num_ies = 0;
	const uint8_t *cur = data;

	memset(ies, 0, sizeof(ies));

	/* build a array of the IEIs */
	while (len >= 2) {
		uint8_t t_len, t_tag;
		len -= 2;
		t_len = *cur++;
		t_tag = *cur++;

		if (t_len > len + 1) {
			LOGP(DLINP, LOGL_ERROR, "IPA CCM tage 0x%02x does not fit\n", t_tag);
			break;
		}

		ies[num_ies++] = t_tag;

		cur += t_len;
		len -= t_len;
	}
	return ipa_ccm_make_id_resp(dev, ies, num_ies);
}

int ipa_send(int fd, const void *msg, size_t msglen)
{
	int ret;

	ret = write(fd, msg, msglen);
	if (ret < 0)
		return -errno;
	if (ret < msglen) {
		LOGP(DLINP, LOGL_ERROR, "ipa_send: short write\n");
		return -EIO;
	}
	return ret;
}

int ipa_ccm_send_pong(int fd)
{
	return ipa_send(fd, ipa_pong_msg, sizeof(ipa_pong_msg));
}

int ipa_ccm_send_id_ack(int fd)
{
	return ipa_send(fd, ipa_id_ack_msg, sizeof(ipa_id_ack_msg));
}

int ipa_ccm_send_id_req(int fd)
{
	return ipa_send(fd, ipa_id_req_msg, sizeof(ipa_id_req_msg));
}

/* base handling of the ip.access protocol */
int ipa_ccm_rcvmsg_base(struct msgb *msg, struct osmo_fd *bfd)
{
	uint8_t msg_type = *(msg->l2h);
	int ret;

	switch (msg_type) {
	case IPAC_MSGT_PING:
		ret = ipa_ccm_send_pong(bfd->fd);
		if (ret < 0) {
			LOGP(DLINP, LOGL_ERROR, "Cannot send PING "
			     "message. Reason: %s\n", strerror(errno));
			break;
		}
		ret = 1;
		break;
	case IPAC_MSGT_PONG:
		DEBUGP(DLMI, "PONG!\n");
		ret = 1;
		break;
	case IPAC_MSGT_ID_ACK:
		DEBUGP(DLMI, "ID_ACK? -> ACK!\n");
		ret = ipa_ccm_send_id_ack(bfd->fd);
		if (ret < 0) {
			LOGP(DLINP, LOGL_ERROR, "Cannot send ID_ACK "
			     "message. Reason: %s\n", strerror(errno));
			break;
		}
		ret = 1;
		break;
	default:
		/* This is not an IPA PING, PONG or ID_ACK message */
		ret = 0;
		break;
	}
	return ret;
}

/* base handling of the ip.access protocol */
int ipa_ccm_rcvmsg_bts_base(struct msgb *msg, struct osmo_fd *bfd)
{
	uint8_t msg_type = *(msg->l2h);
	int ret = 0;

	switch (msg_type) {
	case IPAC_MSGT_PING:
		ret = ipa_ccm_send_pong(bfd->fd);
		if (ret < 0) {
			LOGP(DLINP, LOGL_ERROR, "Cannot send PONG "
			     "message. Reason: %s\n", strerror(errno));
		}
		break;
	case IPAC_MSGT_PONG:
		DEBUGP(DLMI, "PONG!\n");
		break;
	case IPAC_MSGT_ID_ACK:
		DEBUGP(DLMI, "ID_ACK\n");
		break;
	}
	return ret;
}


void ipa_prepend_header_ext(struct msgb *msg, int proto)
{
	struct ipaccess_head_ext *hh_ext;

	/* prepend the osmo ip.access header extension */
	hh_ext = (struct ipaccess_head_ext *) msgb_push(msg, sizeof(*hh_ext));
	hh_ext->proto = proto;
}

void ipa_prepend_header(struct msgb *msg, int proto)
{
	struct ipaccess_head *hh;

	/* prepend the ip.access header */
	hh = (struct ipaccess_head *) msgb_push(msg, sizeof(*hh));
	hh->len = osmo_htons(msg->len - sizeof(*hh));
	hh->proto = proto;
}

#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>

int ipa_msg_recv(int fd, struct msgb **rmsg)
{
	int rc = ipa_msg_recv_buffered(fd, rmsg, NULL);
	if (rc < 0) {
		errno = -rc;
		rc = -1;
	}
	return rc;
}

int ipa_msg_recv_buffered(int fd, struct msgb **rmsg, struct msgb **tmp_msg)
{
	struct msgb *msg = tmp_msg ? *tmp_msg : NULL;
	struct ipaccess_head *hh;
	int len, ret;
	int needed;

	if (msg == NULL) {
		msg = ipa_msg_alloc(0);
		if (msg == NULL) {
			ret = -ENOMEM;
			goto discard_msg;
		}
		msg->l1h = msg->tail;
	}

	if (msg->l2h == NULL) {
		/* first read our 3-byte header */
		needed = sizeof(*hh) - msg->len;
		ret = recv(fd, msg->tail, needed, 0);
		if (ret == 0)
		       goto discard_msg;

		if (ret < 0) {
			if (errno == EAGAIN || errno == EINTR)
				ret = 0;
			else {
				ret = -errno;
				goto discard_msg;
			}
		}

		msgb_put(msg, ret);

		if (ret < needed) {
			if (msg->len == 0) {
				ret = -EAGAIN;
				goto discard_msg;
			}

			LOGP(DLINP, LOGL_INFO,
			     "Received part of IPA message header (%d/%zu)\n",
			     msg->len, sizeof(*hh));
			if (!tmp_msg) {
				ret = -EIO;
				goto discard_msg;
			}
			*tmp_msg = msg;
			return -EAGAIN;
		}

		msg->l2h = msg->tail;
	}

	hh = (struct ipaccess_head *) msg->data;

	/* then read the length as specified in header */
	len = osmo_ntohs(hh->len);

	if (len < 0 || IPA_ALLOC_SIZE < len + sizeof(*hh)) {
		LOGP(DLINP, LOGL_ERROR, "bad message length of %d bytes, "
					"received %d bytes\n", len, msg->len);
		ret = -EIO;
		goto discard_msg;
	}

	needed = len - msgb_l2len(msg);

	if (needed > 0) {
		ret = recv(fd, msg->tail, needed, 0);

		if (ret == 0)
			goto discard_msg;

		if (ret < 0) {
			if (errno == EAGAIN || errno == EINTR)
				ret = 0;
			else {
				ret = -errno;
				goto discard_msg;
			}
		}

		msgb_put(msg, ret);

		if (ret < needed) {
			LOGP(DLINP, LOGL_INFO,
			     "Received part of IPA message L2 data (%d/%d)\n",
			    msgb_l2len(msg), len);
			if (!tmp_msg) {
				ret = -EIO;
				goto discard_msg;
			}
			*tmp_msg = msg;
			return -EAGAIN;
		}
	}

	ret = msgb_l2len(msg);

	if (ret == 0) {
		LOGP(DLINP, LOGL_INFO,
		     "Discarding IPA message without payload\n");
		ret = -EAGAIN;
		goto discard_msg;
	}

	if (tmp_msg)
		*tmp_msg = NULL;
	*rmsg = msg;
	return ret;

discard_msg:
	if (tmp_msg)
		*tmp_msg = NULL;
	msgb_free(msg);
	return ret;
}

#endif /* SYS_SOCKET_H */

struct msgb *ipa_msg_alloc(int headroom)
{
	struct msgb *nmsg;

	headroom += sizeof(struct ipaccess_head);

	nmsg = msgb_alloc_headroom(1200 + headroom, headroom, "Abis/IP");
	if (!nmsg)
		return NULL;
	return nmsg;
}