summaryrefslogtreecommitdiffstats
path: root/sys/netgraph/ng_rfc1490.c
blob: 061faa29fdef61bb6840daf3ddb3309fcfc45964 (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
/*
 * ng_rfc1490.c
 */

/*-
 * Copyright (c) 1996-1999 Whistle Communications, Inc.
 * All rights reserved.
 * 
 * Subject to the following obligations and disclaimer of warranty, use and
 * redistribution of this software, in source or object code forms, with or
 * without modifications are expressly permitted by Whistle Communications;
 * provided, however, that:
 * 1. Any and all reproductions of the source or object code must include the
 *    copyright notice above and the following disclaimer of warranties; and
 * 2. No rights are granted, in any manner or form, to use Whistle
 *    Communications, Inc. trademarks, including the mark "WHISTLE
 *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
 *    such appears in the above copyright notice or in the software.
 * 
 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * Author: Julian Elischer <julian@freebsd.org>
 *
 * $FreeBSD$
 * $Whistle: ng_rfc1490.c,v 1.22 1999/11/01 09:24:52 julian Exp $
 */

/*
 * This node does RFC 1490 multiplexing.
 *
 * NOTE: RFC 1490 is updated by RFC 2427.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/errno.h>
#include <sys/socket.h>

#include <net/if.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>

#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_parse.h>
#include <netgraph/ng_rfc1490.h>

/*
 * DEFINITIONS
 */

/* Q.922 stuff -- see RFC 1490 */
#define HDLC_UI		0x03

#define NLPID_IP	0xCC
#define NLPID_PPP	0xCF
#define NLPID_SNAP	0x80
#define NLPID_Q933	0x08
#define NLPID_CLNP	0x81
#define NLPID_ESIS	0x82
#define NLPID_ISIS	0x83

#define ERROUT(x)	do { error = (x); goto done; } while (0)

/* Encapsulation methods we understand */
enum {
	NG_RFC1490_ENCAP_IETF_IP = 1,	/* see RFC2427, chapter 7, table 1 */
	NG_RFC1490_ENCAP_IETF_SNAP,	/* see RFC2427, chapter 7, table 2 */
	NG_RFC1490_ENCAP_CISCO,		/* Cisco's proprietary encapsulation */
};

struct ng_rfc1490_encap_t {
	u_int8_t	method;
	const char	*name;
};

static const struct ng_rfc1490_encap_t ng_rfc1490_encaps[] = {
	{ NG_RFC1490_ENCAP_IETF_IP,	"ietf-ip" },
	{ NG_RFC1490_ENCAP_IETF_SNAP,	"ietf-snap" },
	{ NG_RFC1490_ENCAP_CISCO,	"cisco" },
	{ 0, NULL},
};

/* Node private data */
struct ng_rfc1490_private {
	hook_p  downlink;
	hook_p  ppp;
	hook_p  inet;
	hook_p  ethernet;
	const struct ng_rfc1490_encap_t *enc;
};
typedef struct ng_rfc1490_private *priv_p;

/* Netgraph node methods */
static ng_constructor_t	ng_rfc1490_constructor;
static ng_rcvmsg_t	ng_rfc1490_rcvmsg;
static ng_shutdown_t	ng_rfc1490_shutdown;
static ng_newhook_t	ng_rfc1490_newhook;
static ng_rcvdata_t	ng_rfc1490_rcvdata;
static ng_disconnect_t	ng_rfc1490_disconnect;

/* List of commands and how to convert arguments to/from ASCII */
static const struct ng_cmdlist ng_rfc1490_cmds[] = {
	{
	  NGM_RFC1490_COOKIE,
	  NGM_RFC1490_SET_ENCAP,
	  "setencap",
	  &ng_parse_string_type,
	  NULL
	},
	{
	  NGM_RFC1490_COOKIE,
	  NGM_RFC1490_GET_ENCAP,
	  "getencap",
	  NULL,
	  &ng_parse_string_type
	},
	{ 0 }
};

/* Node type descriptor */
static struct ng_type typestruct = {
	.version =	NG_ABI_VERSION,
	.name =		NG_RFC1490_NODE_TYPE,
	.constructor =	ng_rfc1490_constructor,
	.rcvmsg =	ng_rfc1490_rcvmsg,
	.shutdown =	ng_rfc1490_shutdown,
	.newhook =	ng_rfc1490_newhook,
	.rcvdata =	ng_rfc1490_rcvdata,
	.disconnect =	ng_rfc1490_disconnect,
	.cmdlist =	ng_rfc1490_cmds,
};
NETGRAPH_INIT(rfc1490, &typestruct);

/************************************************************************
			NETGRAPH NODE STUFF
 ************************************************************************/

/*
 * Node constructor
 */
static int
ng_rfc1490_constructor(node_p node)
{
	priv_p priv;

	/* Allocate private structure */
	priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);

	/* Initialize to default encapsulation method - ietf-ip */
	priv->enc = ng_rfc1490_encaps;

	NG_NODE_SET_PRIVATE(node, priv);

	/* Done */
	return (0);
}

/*
 * Give our ok for a hook to be added
 */
static int
ng_rfc1490_newhook(node_p node, hook_p hook, const char *name)
{
	const priv_p priv = NG_NODE_PRIVATE(node);

	if (!strcmp(name, NG_RFC1490_HOOK_DOWNSTREAM)) {
		if (priv->downlink)
			return (EISCONN);
		priv->downlink = hook;
	} else if (!strcmp(name, NG_RFC1490_HOOK_PPP)) {
		if (priv->ppp)
			return (EISCONN);
		priv->ppp = hook;
	} else if (!strcmp(name, NG_RFC1490_HOOK_INET)) {
		if (priv->inet)
			return (EISCONN);
		priv->inet = hook;
	} else if (!strcmp(name, NG_RFC1490_HOOK_ETHERNET)) {
		if (priv->ethernet)
			return (EISCONN);
		priv->ethernet = hook;
	} else
		return (EINVAL);
	return (0);
}

/*
 * Receive a control message.
 */
static int
ng_rfc1490_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
	const priv_p priv = NG_NODE_PRIVATE(node);
	struct ng_mesg *msg;
	struct ng_mesg *resp = NULL;
	int error = 0;

	NGI_GET_MSG(item, msg);

	if (msg->header.typecookie == NGM_RFC1490_COOKIE) {
		switch (msg->header.cmd) {
		case NGM_RFC1490_SET_ENCAP:
		{
			const struct ng_rfc1490_encap_t *enc;
			char *s;
			size_t len;

			if (msg->header.arglen == 0)
				ERROUT(EINVAL);

			s = (char *)msg->data;
			len = msg->header.arglen - 1;

			/* Search for matching encapsulation method */
			for (enc = ng_rfc1490_encaps; enc->method != 0; enc++ )
				if ((strlen(enc->name) == len) &&
				    !strncmp(enc->name, s, len))
					break;	/* found */

			if (enc->method != 0)
				priv->enc = enc;
			else
				error = EINVAL;
			break;
		}
		case NGM_RFC1490_GET_ENCAP:

			NG_MKRESPONSE(resp, msg, strlen(priv->enc->name) + 1, M_NOWAIT);
			if (resp == NULL)
				ERROUT(ENOMEM);

			strlcpy((char *)resp->data, priv->enc->name,
			    strlen(priv->enc->name) + 1);
			break;

		default:
			error = EINVAL;
			break;
		}
	} else
		error = EINVAL;

done:
	NG_RESPOND_MSG(error, node, item, resp);
	NG_FREE_MSG(msg);
	return (error);
}

/*
 * Receive data on a hook and encapsulate according to RFC 1490.
 * Only those nodes marked (*) are supported by this routine so far.
 *
 *                            Q.922 control
 *                                 |
 *                                 |
 *            ---------------------------------------------------------------------
 *            | 0x03                                     |                        |
 *           UI                                       I Frame                   Cisco
 *            |                                          |                  Encapsulation
 *      ---------------------------------         --------------                  |
 *      | 0x08  | 0x81  |0xCC   |0xCF   | 0x00    |..01....    |..10....   --------------
 *      |       |       |       |       | 0x80    |            |           |0x800       |
 *     Q.933   CLNP    IP(*)   PPP(*)  SNAP     ISO 8208    ISO 8208       |            |
 *      |                    (rfc1973)  |       Modulo 8    Modulo 128     IP(*)     Others
 *      |                               |
 *      --------------------           OUI
 *      |                  |            |
 *     L2 ID              L3 ID      -------------------------
 *      |               User         |00-80-C2               |00-00-00
 *      |               specified    |                       |
 *      |               0x70        PID                     Ethertype
 *      |                            |                       |
 *      -------------------        -----------------...     ----------
 *      |0x51 |0x4E |     |0x4C    |0x7      |0xB  |        |0x806   |
 *      |     |     |     |        |         |     |        |        |
 *     7776  Q.922 Others 802.2   802.3(*)  802.6 Others    IP(*)   Others
 *
 *
 */

#define MAX_ENCAPS_HDR	8
#define OUICMP(P,A,B,C)	((P)[0]==(A) && (P)[1]==(B) && (P)[2]==(C))

static int
ng_rfc1490_rcvdata(hook_p hook, item_p item)
{
	const node_p node = NG_HOOK_NODE(hook);
	const priv_p priv = NG_NODE_PRIVATE(node);
	int error = 0;
	struct mbuf *m;

	NGI_GET_M(item, m);
	if (hook == priv->downlink) {
		const u_char *start;
		const u_char *ptr;

		if (m->m_len < MAX_ENCAPS_HDR
		    && !(m = m_pullup(m, MAX_ENCAPS_HDR)))
			ERROUT(ENOBUFS);
		ptr = start = mtod(m, const u_char *);

		if (priv->enc->method == NG_RFC1490_ENCAP_CISCO)
			goto switch_on_etype;

		/* Must be UI frame */
		if (*ptr++ != HDLC_UI)
			ERROUT(0);

		/* Eat optional zero pad byte */
		if (*ptr == 0x00)
			ptr++;

		/* Multiplex on NLPID */
		switch (*ptr++) {
		case NLPID_SNAP:
			if (OUICMP(ptr, 0, 0, 0)) {	/* It's an ethertype */
				u_int16_t etype;

				ptr += 3;
switch_on_etype:		etype = ntohs(*((const u_int16_t *)ptr));
				ptr += 2;
				m_adj(m, ptr - start);
				switch (etype) {
				case ETHERTYPE_IP:
					NG_FWD_NEW_DATA(error, item,
					    priv->inet, m);
					break;
				case ETHERTYPE_ARP:
				case ETHERTYPE_REVARP:
				default:
					ERROUT(0);
				}
			} else if (OUICMP(ptr, 0x00, 0x80, 0xc2)) {
				/* 802.1 bridging */
				ptr += 3;
				if (*ptr++ != 0x00)
					ERROUT(0);	/* unknown PID octet 0 */
				if (*ptr++ != 0x07)
					ERROUT(0);	/* not FCS-less 802.3 */
				m_adj(m, ptr - start);
				NG_FWD_NEW_DATA(error, item, priv->ethernet, m);
			} else	/* Other weird stuff... */
				ERROUT(0);
			break;
		case NLPID_IP:
			m_adj(m, ptr - start);
			NG_FWD_NEW_DATA(error, item, priv->inet, m);
			break;
		case NLPID_PPP:
			m_adj(m, ptr - start);
			NG_FWD_NEW_DATA(error, item, priv->ppp, m);
			break;
		case NLPID_Q933:
		case NLPID_CLNP:
		case NLPID_ESIS:
		case NLPID_ISIS:
			ERROUT(0);
		default:	/* Try PPP (see RFC 1973) */
			ptr--;	/* NLPID becomes PPP proto */
			if ((*ptr & 0x01) == 0x01)
				ERROUT(0);
			m_adj(m, ptr - start);
			NG_FWD_NEW_DATA(error, item, priv->ppp, m);
			break;
		}
	} else if (hook == priv->ppp) {
		M_PREPEND(m, 2, M_NOWAIT);	/* Prepend PPP NLPID */
		if (!m)
			ERROUT(ENOBUFS);
		mtod(m, u_char *)[0] = HDLC_UI;
		mtod(m, u_char *)[1] = NLPID_PPP;
		NG_FWD_NEW_DATA(error, item, priv->downlink, m);
	} else if (hook == priv->inet) {
		switch (priv->enc->method) {
		case NG_RFC1490_ENCAP_IETF_IP:
			M_PREPEND(m, 2, M_NOWAIT);	/* Prepend IP NLPID */
			if (!m)
				ERROUT(ENOBUFS);
			mtod(m, u_char *)[0] = HDLC_UI;
			mtod(m, u_char *)[1] = NLPID_IP;
			break;
		case NG_RFC1490_ENCAP_IETF_SNAP:
			/*
			 *  According to RFC2427 frame should begin with
			 *  HDLC_UI  PAD  NLIPID  OUI      PID
			 *  03      00   80      00 00 00  08 00
			 */
			M_PREPEND(m, 8, M_NOWAIT);
			if (!m)
				ERROUT(ENOBUFS);
			mtod(m, u_char *)[0] = HDLC_UI;
			mtod(m, u_char *)[1] = 0x00;			/* PAD */
			mtod(m, u_char *)[2] = NLPID_SNAP;
			bzero((char *)(mtod(m, u_char *) + 3), 3);	/* OUI 0-0-0 */
			*((u_int16_t *)mtod(m, u_int16_t *) + 6/sizeof(u_int16_t))
			    = htons(ETHERTYPE_IP);  /* PID */
			break;
		case NG_RFC1490_ENCAP_CISCO:
			M_PREPEND(m, 2, M_NOWAIT);	/* Prepend IP ethertype */
			if (!m)
				ERROUT(ENOBUFS);
			*((u_int16_t *)mtod(m, u_int16_t *)) = htons(ETHERTYPE_IP);
			break;
		}
		NG_FWD_NEW_DATA(error, item, priv->downlink, m);
	} else if (hook == priv->ethernet) {
		M_PREPEND(m, 8, M_NOWAIT);	/* Prepend NLPID, OUI, PID */
		if (!m)
			ERROUT(ENOBUFS);
		mtod(m, u_char *)[0] = HDLC_UI;
		mtod(m, u_char *)[1] = 0x00;		/* pad */
		mtod(m, u_char *)[2] = NLPID_SNAP;
		mtod(m, u_char *)[3] = 0x00;		/* OUI */
		mtod(m, u_char *)[4] = 0x80;
		mtod(m, u_char *)[5] = 0xc2;
		mtod(m, u_char *)[6] = 0x00;		/* PID */
		mtod(m, u_char *)[7] = 0x07;
		NG_FWD_NEW_DATA(error, item, priv->downlink, m);
	} else
		panic("%s", __func__);

done:
	if (item)
		NG_FREE_ITEM(item);
	NG_FREE_M(m);
	return (error);
}

/*
 * Nuke node
 */
static int
ng_rfc1490_shutdown(node_p node)
{
	const priv_p priv = NG_NODE_PRIVATE(node);

	/* Take down netgraph node */
	bzero(priv, sizeof(*priv));
	free(priv, M_NETGRAPH);
	NG_NODE_SET_PRIVATE(node, NULL);
	NG_NODE_UNREF(node);		/* let the node escape */
	return (0);
}

/*
 * Hook disconnection
 */
static int
ng_rfc1490_disconnect(hook_p hook)
{
	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));

	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
	&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
		ng_rmnode_self(NG_HOOK_NODE(hook));
	else if (hook == priv->downlink)
		priv->downlink = NULL;
	else if (hook == priv->inet)
		priv->inet = NULL;
	else if (hook == priv->ppp)
		priv->ppp = NULL;
	else if (hook == priv->ethernet)
		priv->ethernet = NULL;
	else
		panic("%s", __func__);
	return (0);
}

OpenPOWER on IntegriCloud