xref: /freebsd/sys/netgraph/ng_lmi.c (revision f9218d3d4fd34f082473b3a021c6d4d109fb47cf)
1 
2 /*
3  * ng_lmi.c
4  *
5  * Copyright (c) 1996-1999 Whistle Communications, Inc.
6  * All rights reserved.
7  *
8  * Subject to the following obligations and disclaimer of warranty, use and
9  * redistribution of this software, in source or object code forms, with or
10  * without modifications are expressly permitted by Whistle Communications;
11  * provided, however, that:
12  * 1. Any and all reproductions of the source or object code must include the
13  *    copyright notice above and the following disclaimer of warranties; and
14  * 2. No rights are granted, in any manner or form, to use Whistle
15  *    Communications, Inc. trademarks, including the mark "WHISTLE
16  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
17  *    such appears in the above copyright notice or in the software.
18  *
19  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
20  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
21  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
22  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
23  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
24  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
25  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
26  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
27  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
28  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
29  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
30  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
31  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
35  * OF SUCH DAMAGE.
36  *
37  * Author: Julian Elischer <julian@freebsd.org>
38  *
39  * $FreeBSD$
40  * $Whistle: ng_lmi.c,v 1.38 1999/11/01 09:24:52 julian Exp $
41  */
42 
43 /*
44  * This node performs the frame relay LMI protocol. It knows how
45  * to do ITU Annex A, ANSI Annex D, and "Group-of-Four" variants
46  * of the protocol.
47  *
48  * A specific protocol can be forced by connecting the corresponding
49  * hook to DLCI 0 or 1023 (as appropriate) of a frame relay link.
50  *
51  * Alternately, this node can do auto-detection of the LMI protocol
52  * by connecting hook "auto0" to DLCI 0 and "auto1023" to DLCI 1023.
53  */
54 
55 #include <sys/param.h>
56 #include <sys/systm.h>
57 #include <sys/errno.h>
58 #include <sys/kernel.h>
59 #include <sys/malloc.h>
60 #include <sys/mbuf.h>
61 #include <sys/syslog.h>
62 #include <netgraph/ng_message.h>
63 #include <netgraph/netgraph.h>
64 #include <netgraph/ng_lmi.h>
65 
66 /*
67  * Human readable names for LMI
68  */
69 #define NAME_ANNEXA	NG_LMI_HOOK_ANNEXA
70 #define NAME_ANNEXD	NG_LMI_HOOK_ANNEXD
71 #define NAME_GROUP4	NG_LMI_HOOK_GROUPOF4
72 #define NAME_NONE	"None"
73 
74 #define MAX_DLCIS	128
75 #define MAXDLCI		1023
76 
77 /*
78  * DLCI states
79  */
80 #define DLCI_NULL	0
81 #define DLCI_UP		1
82 #define DLCI_DOWN	2
83 
84 /*
85  * Any received LMI frame should be at least this long
86  */
87 #define LMI_MIN_LENGTH	8	/* XXX verify */
88 
89 /*
90  * Netgraph node methods and type descriptor
91  */
92 static ng_constructor_t	nglmi_constructor;
93 static ng_rcvmsg_t	nglmi_rcvmsg;
94 static ng_shutdown_t	nglmi_shutdown;
95 static ng_newhook_t	nglmi_newhook;
96 static ng_rcvdata_t	nglmi_rcvdata;
97 static ng_disconnect_t	nglmi_disconnect;
98 static int	nglmi_checkdata(hook_p hook, struct mbuf *m);
99 
100 static struct ng_type typestruct = {
101 	NG_ABI_VERSION,
102 	NG_LMI_NODE_TYPE,
103 	NULL,
104 	nglmi_constructor,
105 	nglmi_rcvmsg,
106 	nglmi_shutdown,
107 	nglmi_newhook,
108 	NULL,
109 	NULL,
110 	nglmi_rcvdata,
111 	nglmi_disconnect,
112 	NULL
113 };
114 NETGRAPH_INIT(lmi, &typestruct);
115 
116 /*
117  * Info and status per node
118  */
119 struct nglmi_softc {
120 	node_p  node;		/* netgraph node */
121 	int     flags;		/* state */
122 	int     poll_count;	/* the count of times for autolmi */
123 	int     poll_state;	/* state of auto detect machine */
124 	u_char  remote_seq;	/* sequence number the remote sent */
125 	u_char  local_seq;	/* last sequence number we sent */
126 	u_char  protoID;	/* 9 for group of 4, 8 otherwise */
127 	u_long  seq_retries;	/* sent this how many time so far */
128 	struct callout_handle handle;	/* see timeout(9) */
129 	int     liv_per_full;
130 	int     liv_rate;
131 	int     livs;
132 	int     need_full;
133 	hook_p  lmi_channel;	/* whatever we ended up using */
134 	hook_p  lmi_annexA;
135 	hook_p  lmi_annexD;
136 	hook_p  lmi_group4;
137 	hook_p  lmi_channel0;	/* auto-detect on DLCI 0 */
138 	hook_p  lmi_channel1023;/* auto-detect on DLCI 1023 */
139 	char   *protoname;	/* cache protocol name */
140 	u_char  dlci_state[MAXDLCI + 1];
141 	int     invalidx;	/* next dlci's to invalidate */
142 };
143 typedef struct nglmi_softc *sc_p;
144 
145 /*
146  * Other internal functions
147  */
148 static void	LMI_ticker(void *arg);
149 static void	nglmi_startup_fixed(sc_p sc, hook_p hook);
150 static void	nglmi_startup_auto(sc_p sc);
151 static void	nglmi_startup(sc_p sc);
152 static void	nglmi_inquire(sc_p sc, int full);
153 static void	ngauto_state_machine(sc_p sc);
154 
155 /*
156  * Values for 'flags' field
157  * NB: the SCF_CONNECTED flag is set if and only if the timer is running.
158  */
159 #define	SCF_CONNECTED	0x01	/* connected to something */
160 #define	SCF_AUTO	0x02	/* we are auto-detecting */
161 #define	SCF_FIXED	0x04	/* we are fixed from the start */
162 
163 #define	SCF_LMITYPE	0x18	/* mask for determining Annex mode */
164 #define	SCF_NOLMI	0x00	/* no LMI type selected yet */
165 #define	SCF_ANNEX_A	0x08	/* running annex A mode */
166 #define	SCF_ANNEX_D	0x10	/* running annex D mode */
167 #define	SCF_GROUP4	0x18	/* running group of 4 */
168 
169 #define SETLMITYPE(sc, annex)						\
170 do {									\
171 	(sc)->flags &= ~SCF_LMITYPE;					\
172 	(sc)->flags |= (annex);						\
173 } while (0)
174 
175 #define NOPROTO(sc) (((sc)->flags & SCF_LMITYPE) == SCF_NOLMI)
176 #define ANNEXA(sc) (((sc)->flags & SCF_LMITYPE) == SCF_ANNEX_A)
177 #define ANNEXD(sc) (((sc)->flags & SCF_LMITYPE) == SCF_ANNEX_D)
178 #define GROUP4(sc) (((sc)->flags & SCF_LMITYPE) == SCF_GROUP4)
179 
180 #define LMIPOLLSIZE	3
181 #define LMI_PATIENCE	8	/* declare all DLCI DOWN after N LMI failures */
182 
183 /*
184  * Node constructor
185  */
186 static int
187 nglmi_constructor(node_p node)
188 {
189 	sc_p sc;
190 
191 	MALLOC(sc, sc_p, sizeof(*sc), M_NETGRAPH, M_NOWAIT | M_ZERO);
192 	if (sc == NULL)
193 		return (ENOMEM);
194 	callout_handle_init(&sc->handle);
195 	NG_NODE_SET_PRIVATE(node, sc);
196 	sc->protoname = NAME_NONE;
197 	sc->node = node;
198 	sc->liv_per_full = NG_LMI_SEQ_PER_FULL;	/* make this dynamic */
199 	sc->liv_rate = NG_LMI_KEEPALIVE_RATE;
200 	return (0);
201 }
202 
203 /*
204  * The LMI channel has a private pointer which is the same as the
205  * node private pointer. The debug channel has a NULL private pointer.
206  */
207 static int
208 nglmi_newhook(node_p node, hook_p hook, const char *name)
209 {
210 	sc_p sc = NG_NODE_PRIVATE(node);
211 
212 	if (strcmp(name, NG_LMI_HOOK_DEBUG) == 0) {
213 		NG_HOOK_SET_PRIVATE(hook, NULL);
214 		return (0);
215 	}
216 	if (sc->flags & SCF_CONNECTED) {
217 		/* already connected, return an error */
218 		return (EINVAL);
219 	}
220 	if (strcmp(name, NG_LMI_HOOK_ANNEXA) == 0) {
221 		sc->lmi_annexA = hook;
222 		NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
223 		sc->protoID = 8;
224 		SETLMITYPE(sc, SCF_ANNEX_A);
225 		sc->protoname = NAME_ANNEXA;
226 		nglmi_startup_fixed(sc, hook);
227 	} else if (strcmp(name, NG_LMI_HOOK_ANNEXD) == 0) {
228 		sc->lmi_annexD = hook;
229 		NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
230 		sc->protoID = 8;
231 		SETLMITYPE(sc, SCF_ANNEX_D);
232 		sc->protoname = NAME_ANNEXD;
233 		nglmi_startup_fixed(sc, hook);
234 	} else if (strcmp(name, NG_LMI_HOOK_GROUPOF4) == 0) {
235 		sc->lmi_group4 = hook;
236 		NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
237 		sc->protoID = 9;
238 		SETLMITYPE(sc, SCF_GROUP4);
239 		sc->protoname = NAME_GROUP4;
240 		nglmi_startup_fixed(sc, hook);
241 	} else if (strcmp(name, NG_LMI_HOOK_AUTO0) == 0) {
242 		/* Note this, and if B is already installed, we're complete */
243 		sc->lmi_channel0 = hook;
244 		sc->protoname = NAME_NONE;
245 		NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
246 		if (sc->lmi_channel1023)
247 			nglmi_startup_auto(sc);
248 	} else if (strcmp(name, NG_LMI_HOOK_AUTO1023) == 0) {
249 		/* Note this, and if A is already installed, we're complete */
250 		sc->lmi_channel1023 = hook;
251 		sc->protoname = NAME_NONE;
252 		NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
253 		if (sc->lmi_channel0)
254 			nglmi_startup_auto(sc);
255 	} else
256 		return (EINVAL);		/* unknown hook */
257 	return (0);
258 }
259 
260 /*
261  * We have just attached to a live (we hope) node.
262  * Fire out a LMI inquiry, and then start up the timers.
263  */
264 static void
265 LMI_ticker(void *arg)
266 {
267 	sc_p sc = arg;
268 	int s = splnet();
269 
270 	if (sc->flags & SCF_AUTO) {
271 		ngauto_state_machine(sc);
272 		sc->handle = timeout(LMI_ticker, sc, NG_LMI_POLL_RATE * hz);
273 	} else {
274 		if (sc->livs++ >= sc->liv_per_full) {
275 			nglmi_inquire(sc, 1);
276 			/* sc->livs = 0; *//* do this when we get the answer! */
277 		} else {
278 			nglmi_inquire(sc, 0);
279 		}
280 		sc->handle = timeout(LMI_ticker, sc, sc->liv_rate * hz);
281 	}
282 	splx(s);
283 }
284 
285 static void
286 nglmi_startup_fixed(sc_p sc, hook_p hook)
287 {
288 	sc->flags |= (SCF_FIXED | SCF_CONNECTED);
289 	sc->lmi_channel = hook;
290 	nglmi_startup(sc);
291 }
292 
293 static void
294 nglmi_startup_auto(sc_p sc)
295 {
296 	sc->flags |= (SCF_AUTO | SCF_CONNECTED);
297 	sc->poll_state = 0;	/* reset state machine */
298 	sc->poll_count = 0;
299 	nglmi_startup(sc);
300 }
301 
302 static void
303 nglmi_startup(sc_p sc)
304 {
305 	sc->remote_seq = 0;
306 	sc->local_seq = 1;
307 	sc->seq_retries = 0;
308 	sc->livs = sc->liv_per_full - 1;
309 	/* start off the ticker in 1 sec */
310 	sc->handle = timeout(LMI_ticker, sc, hz);
311 }
312 
313 #define META_PAD 16
314 static void
315 nglmi_inquire(sc_p sc, int full)
316 {
317 	struct mbuf *m;
318 	char   *cptr, *start;
319 	int     error;
320 	meta_p  meta = NULL;
321 
322 	if (sc->lmi_channel == NULL)
323 		return;
324 	MGETHDR(m, M_DONTWAIT, MT_DATA);
325 	if (m == NULL) {
326 		log(LOG_ERR, "nglmi: unable to start up LMI processing\n");
327 		return;
328 	}
329 	m->m_pkthdr.rcvif = NULL;
330 	/* Allocate a meta struct (and leave some slop for options to be
331 	 * added by other modules). */
332 	MALLOC(meta, meta_p, sizeof(*meta) + META_PAD, M_NETGRAPH_META, M_NOWAIT);
333 	if (meta != NULL) {	/* if it failed, well, it was optional anyhow */
334 		meta->used_len = (u_short) sizeof(struct ng_meta);
335 		meta->allocated_len
336 		    = (u_short) sizeof(struct ng_meta) + META_PAD;
337 		meta->flags = 0;
338 		meta->priority = NG_LMI_LMI_PRIORITY;
339 		meta->discardability = -1;
340 	}
341 	m->m_data += 4;		/* leave some room for a header */
342 	cptr = start = mtod(m, char *);
343 	/* add in the header for an LMI inquiry. */
344 	*cptr++ = 0x03;		/* UI frame */
345 	if (GROUP4(sc))
346 		*cptr++ = 0x09;	/* proto discriminator */
347 	else
348 		*cptr++ = 0x08;	/* proto discriminator */
349 	*cptr++ = 0x00;		/* call reference */
350 	*cptr++ = 0x75;		/* inquiry */
351 
352 	/* If we are Annex-D, there is this extra thing.. */
353 	if (ANNEXD(sc))
354 		*cptr++ = 0x95;	/* ??? */
355 	/* Add a request type */
356 	if (ANNEXA(sc))
357 		*cptr++ = 0x51;	/* report type */
358 	else
359 		*cptr++ = 0x01;	/* report type */
360 	*cptr++ = 0x01;		/* size = 1 */
361 	if (full)
362 		*cptr++ = 0x00;	/* full */
363 	else
364 		*cptr++ = 0x01;	/* partial */
365 
366 	/* Add a link verification IE */
367 	if (ANNEXA(sc))
368 		*cptr++ = 0x53;	/* verification IE */
369 	else
370 		*cptr++ = 0x03;	/* verification IE */
371 	*cptr++ = 0x02;		/* 2 extra bytes */
372 	*cptr++ = sc->local_seq;
373 	*cptr++ = sc->remote_seq;
374 	sc->seq_retries++;
375 
376 	/* Send it */
377 	m->m_len = m->m_pkthdr.len = cptr - start;
378 	NG_SEND_DATA(error, sc->lmi_channel, m, meta);
379 
380 	/* If we've been sending requests for long enough, and there has
381 	 * been no response, then mark as DOWN, any DLCIs that are UP. */
382 	if (sc->seq_retries == LMI_PATIENCE) {
383 		int     count;
384 
385 		for (count = 0; count < MAXDLCI; count++)
386 			if (sc->dlci_state[count] == DLCI_UP)
387 				sc->dlci_state[count] = DLCI_DOWN;
388 	}
389 }
390 
391 /*
392  * State machine for LMI auto-detect. The transitions are ordered
393  * to try the more likely possibilities first.
394  */
395 static void
396 ngauto_state_machine(sc_p sc)
397 {
398 	if ((sc->poll_count <= 0) || (sc->poll_count > LMIPOLLSIZE)) {
399 		/* time to change states in the auto probe machine */
400 		/* capture wild values of poll_count while we are at it */
401 		sc->poll_count = LMIPOLLSIZE;
402 		sc->poll_state++;
403 	}
404 	switch (sc->poll_state) {
405 	case 7:
406 		log(LOG_WARNING, "nglmi: no response from exchange\n");
407 	default:		/* capture bad states */
408 		sc->poll_state = 1;
409 	case 1:
410 		sc->lmi_channel = sc->lmi_channel0;
411 		SETLMITYPE(sc, SCF_ANNEX_D);
412 		break;
413 	case 2:
414 		sc->lmi_channel = sc->lmi_channel1023;
415 		SETLMITYPE(sc, SCF_ANNEX_D);
416 		break;
417 	case 3:
418 		sc->lmi_channel = sc->lmi_channel0;
419 		SETLMITYPE(sc, SCF_ANNEX_A);
420 		break;
421 	case 4:
422 		sc->lmi_channel = sc->lmi_channel1023;
423 		SETLMITYPE(sc, SCF_GROUP4);
424 		break;
425 	case 5:
426 		sc->lmi_channel = sc->lmi_channel1023;
427 		SETLMITYPE(sc, SCF_ANNEX_A);
428 		break;
429 	case 6:
430 		sc->lmi_channel = sc->lmi_channel0;
431 		SETLMITYPE(sc, SCF_GROUP4);
432 		break;
433 	}
434 
435 	/* send an inquirey encoded appropriatly */
436 	nglmi_inquire(sc, 0);
437 	sc->poll_count--;
438 }
439 
440 /*
441  * Receive a netgraph control message.
442  */
443 static int
444 nglmi_rcvmsg(node_p node, item_p item, hook_p lasthook)
445 {
446 	sc_p    sc = NG_NODE_PRIVATE(node);
447 	struct ng_mesg *resp = NULL;
448 	int     error = 0;
449 	struct ng_mesg *msg;
450 
451 	NGI_GET_MSG(item, msg);
452 	switch (msg->header.typecookie) {
453 	case NGM_GENERIC_COOKIE:
454 		switch (msg->header.cmd) {
455 		case NGM_TEXT_STATUS:
456 		    {
457 			char   *arg;
458 			int     pos, count;
459 
460 			NG_MKRESPONSE(resp, msg, NG_TEXTRESPONSE, M_NOWAIT);
461 			if (resp == NULL) {
462 				error = ENOMEM;
463 				break;
464 			}
465 			arg = resp->data;
466 			pos = sprintf(arg, "protocol %s ", sc->protoname);
467 			if (sc->flags & SCF_FIXED)
468 				pos += sprintf(arg + pos, "fixed\n");
469 			else if (sc->flags & SCF_AUTO)
470 				pos += sprintf(arg + pos, "auto-detecting\n");
471 			else
472 				pos += sprintf(arg + pos, "auto on dlci %d\n",
473 				    (sc->lmi_channel == sc->lmi_channel0) ?
474 				    0 : 1023);
475 			pos += sprintf(arg + pos,
476 			    "keepalive period: %d seconds\n", sc->liv_rate);
477 			pos += sprintf(arg + pos,
478 			    "unacknowledged keepalives: %ld\n",
479 			    sc->seq_retries);
480 			for (count = 0;
481 			     ((count <= MAXDLCI)
482 			      && (pos < (NG_TEXTRESPONSE - 20)));
483 			     count++) {
484 				if (sc->dlci_state[count]) {
485 					pos += sprintf(arg + pos,
486 					       "dlci %d %s\n", count,
487 					       (sc->dlci_state[count]
488 					== DLCI_UP) ? "up" : "down");
489 				}
490 			}
491 			resp->header.arglen = pos + 1;
492 			break;
493 		    }
494 		default:
495 			error = EINVAL;
496 			break;
497 		}
498 		break;
499 	case NGM_LMI_COOKIE:
500 		switch (msg->header.cmd) {
501 		case NGM_LMI_GET_STATUS:
502 		    {
503 			struct nglmistat *stat;
504 			int k;
505 
506 			NG_MKRESPONSE(resp, msg, sizeof(*stat), M_NOWAIT);
507 			if (!resp) {
508 				error = ENOMEM;
509 				break;
510 			}
511 			stat = (struct nglmistat *) resp->data;
512 			strncpy(stat->proto,
513 			     sc->protoname, sizeof(stat->proto) - 1);
514 			strncpy(stat->hook,
515 			      sc->protoname, sizeof(stat->hook) - 1);
516 			stat->autod = !!(sc->flags & SCF_AUTO);
517 			stat->fixed = !!(sc->flags & SCF_FIXED);
518 			for (k = 0; k <= MAXDLCI; k++) {
519 				switch (sc->dlci_state[k]) {
520 				case DLCI_UP:
521 					stat->up[k / 8] |= (1 << (k % 8));
522 					/* fall through */
523 				case DLCI_DOWN:
524 					stat->seen[k / 8] |= (1 << (k % 8));
525 					break;
526 				}
527 			}
528 			break;
529 		    }
530 		default:
531 			error = EINVAL;
532 			break;
533 		}
534 		break;
535 	default:
536 		error = EINVAL;
537 		break;
538 	}
539 
540 	NG_RESPOND_MSG(error, node, item, resp);
541 	NG_FREE_MSG(msg);
542 	return (error);
543 }
544 
545 #define STEPBY(stepsize)			\
546 	do {					\
547 		packetlen -= (stepsize);	\
548 		data += (stepsize);		\
549 	} while (0)
550 
551 /*
552  * receive data, and use it to update our status.
553  * Anything coming in on the debug port is discarded.
554  */
555 static int
556 nglmi_rcvdata(hook_p hook, item_p item)
557 {
558 	sc_p    sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
559 	const	u_char *data;
560 	unsigned short dlci;
561 	u_short packetlen;
562 	int     resptype_seen = 0;
563 	int     seq_seen = 0;
564 	struct mbuf *m;
565 
566 	NGI_GET_M(item, m);
567 	NG_FREE_ITEM(item);
568 	if (NG_HOOK_PRIVATE(hook) == NULL) {
569 		goto drop;
570 	}
571 	packetlen = m->m_hdr.mh_len;
572 
573 	/* XXX what if it's more than 1 mbuf? */
574 	if ((packetlen > MHLEN) && !(m->m_flags & M_EXT)) {
575 		log(LOG_WARNING, "nglmi: packetlen (%d) too big\n", packetlen);
576 		goto drop;
577 	}
578 	if (m->m_len < packetlen && (m = m_pullup(m, packetlen)) == NULL) {
579 		log(LOG_WARNING,
580 		    "nglmi: m_pullup failed for %d bytes\n", packetlen);
581 		return (0);
582 	}
583 	if (nglmi_checkdata(hook, m) == 0)
584 		return (0);
585 
586 	/* pass the first 4 bytes (already checked in the nglmi_checkdata()) */
587 	data = mtod(m, const u_char *);
588 	STEPBY(4);
589 
590 	/* Now check if there is a 'locking shift'. This is only seen in
591 	 * Annex D frames. don't bother checking, we already did that. Don't
592 	 * increment immediatly as it might not be there. */
593 	if (ANNEXD(sc))
594 		STEPBY(1);
595 
596 	/* If we get this far we should consider that it is a legitimate
597 	 * frame and we know what it is. */
598 	if (sc->flags & SCF_AUTO) {
599 		/* note the hook that this valid channel came from and drop
600 		 * out of auto probe mode. */
601 		if (ANNEXA(sc))
602 			sc->protoname = NAME_ANNEXA;
603 		else if (ANNEXD(sc))
604 			sc->protoname = NAME_ANNEXD;
605 		else if (GROUP4(sc))
606 			sc->protoname = NAME_GROUP4;
607 		else {
608 			log(LOG_ERR, "nglmi: No known type\n");
609 			goto drop;
610 		}
611 		sc->lmi_channel = hook;
612 		sc->flags &= ~SCF_AUTO;
613 		log(LOG_INFO, "nglmi: auto-detected %s LMI on DLCI %d\n",
614 		    sc->protoname, hook == sc->lmi_channel0 ? 0 : 1023);
615 	}
616 
617 	/* While there is more data in the status packet, keep processing
618 	 * status items. First make sure there is enough data for the
619 	 * segment descriptor's length field. */
620 	while (packetlen >= 2) {
621 		u_int   segtype = data[0];
622 		u_int   segsize = data[1];
623 
624 		/* Now that we know how long it claims to be, make sure
625 		 * there is enough data for the next seg. */
626 		if (packetlen < segsize + 2)
627 			break;
628 		switch (segtype) {
629 		case 0x01:
630 		case 0x51:
631 			if (resptype_seen) {
632 				log(LOG_WARNING, "nglmi: dup MSGTYPE\n");
633 				goto nextIE;
634 			}
635 			resptype_seen++;
636 			/* The remote end tells us what kind of response
637 			 * this is. Only expect a type 0 or 1. if we are a
638 			 * full status, invalidate a few DLCIs just to see
639 			 * that they are still ok. */
640 			if (segsize != 1)
641 				goto nextIE;
642 			switch (data[2]) {
643 			case 1:
644 				/* partial status, do no extra processing */
645 				break;
646 			case 0:
647 			    {
648 				int     count = 0;
649 				int     idx = sc->invalidx;
650 
651 				for (count = 0; count < 10; count++) {
652 					if (idx > MAXDLCI)
653 						idx = 0;
654 					if (sc->dlci_state[idx] == DLCI_UP)
655 						sc->dlci_state[idx] = DLCI_DOWN;
656 					idx++;
657 				}
658 				sc->invalidx = idx;
659 				/* we got and we wanted one. relax
660 				 * now.. but don't reset to 0 if it
661 				 * was unrequested. */
662 				if (sc->livs > sc->liv_per_full)
663 					sc->livs = 0;
664 				break;
665 			    }
666 			}
667 			break;
668 		case 0x03:
669 		case 0x53:
670 			/* The remote tells us what it thinks the sequence
671 			 * numbers are. If it's not size 2, it must be a
672 			 * duplicate to have gotten this far, skip it. */
673 			if (seq_seen != 0)	/* already seen seq numbers */
674 				goto nextIE;
675 			if (segsize != 2)
676 				goto nextIE;
677 			sc->remote_seq = data[2];
678 			if (sc->local_seq == data[3]) {
679 				sc->local_seq++;
680 				sc->seq_retries = 0;
681 				/* Note that all 3 Frame protocols seem to
682 				 * not like 0 as a sequence number. */
683 				if (sc->local_seq == 0)
684 					sc->local_seq = 1;
685 			}
686 			break;
687 		case 0x07:
688 		case 0x57:
689 			/* The remote tells us about a DLCI that it knows
690 			 * about. There may be many of these in a single
691 			 * status response */
692 			switch (segsize) {
693 			case 6:/* only on 'group of 4' */
694 				dlci = ((u_short) data[2] & 0xff) << 8;
695 				dlci |= (data[3] & 0xff);
696 				if ((dlci < 1024) && (dlci > 0)) {
697 				  /* XXX */
698 				}
699 				break;
700 			case 3:
701 				dlci = ((u_short) data[2] & 0x3f) << 4;
702 				dlci |= ((data[3] & 0x78) >> 3);
703 				if ((dlci < 1024) && (dlci > 0)) {
704 					/* set up the bottom half of the
705 					 * support for that dlci if it's not
706 					 * already been done */
707 					/* store this information somewhere */
708 				}
709 				break;
710 			default:
711 				goto nextIE;
712 			}
713 			if (sc->dlci_state[dlci] != DLCI_UP) {
714 				/* bring new DLCI to life */
715 				/* may do more here some day */
716 				if (sc->dlci_state[dlci] != DLCI_DOWN)
717 					log(LOG_INFO,
718 					    "nglmi: DLCI %d became active\n",
719 					    dlci);
720 				sc->dlci_state[dlci] = DLCI_UP;
721 			}
722 			break;
723 		}
724 nextIE:
725 		STEPBY(segsize + 2);
726 	}
727 	NG_FREE_M(m);
728 	return (0);
729 
730 drop:
731 	NG_FREE_M(m);
732 	return (EINVAL);
733 }
734 
735 /*
736  * Check that a packet is entirely kosha.
737  * return 1 of ok, and 0 if not.
738  * All data is discarded if a 0 is returned.
739  */
740 static int
741 nglmi_checkdata(hook_p hook, struct mbuf *m)
742 {
743 	sc_p    sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
744 	const	u_char *data;
745 	u_short packetlen;
746 	unsigned short dlci;
747 	u_char  type;
748 	u_char  nextbyte;
749 	int     seq_seen = 0;
750 	int     resptype_seen = 0;	/* 0 , 1 (partial) or 2 (full) */
751 	int     highest_dlci = 0;
752 
753 	packetlen = m->m_hdr.mh_len;
754 	data = mtod(m, const u_char *);
755 	if (*data != 0x03) {
756 		log(LOG_WARNING, "nglmi: unexpected value in LMI(%d)\n", 1);
757 		goto reject;
758 	}
759 	STEPBY(1);
760 
761 	/* look at the protocol ID */
762 	nextbyte = *data;
763 	if (sc->flags & SCF_AUTO) {
764 		SETLMITYPE(sc, SCF_NOLMI);	/* start with a clean slate */
765 		switch (nextbyte) {
766 		case 0x8:
767 			sc->protoID = 8;
768 			break;
769 		case 0x9:
770 			SETLMITYPE(sc, SCF_GROUP4);
771 			sc->protoID = 9;
772 			break;
773 		default:
774 			log(LOG_WARNING, "nglmi: bad Protocol ID(%d)\n",
775 			    (int) nextbyte);
776 			goto reject;
777 		}
778 	} else {
779 		if (nextbyte != sc->protoID) {
780 			log(LOG_WARNING, "nglmi: unexpected Protocol ID(%d)\n",
781 			    (int) nextbyte);
782 			goto reject;
783 		}
784 	}
785 	STEPBY(1);
786 
787 	/* check call reference (always null in non ISDN frame relay) */
788 	if (*data != 0x00) {
789 		log(LOG_WARNING, "nglmi: unexpected Call Reference (0x%x)\n",
790 		    data[-1]);
791 		goto reject;
792 	}
793 	STEPBY(1);
794 
795 	/* check message type */
796 	switch ((type = *data)) {
797 	case 0x75:		/* Status enquiry */
798 		log(LOG_WARNING, "nglmi: unexpected message type(0x%x)\n",
799 		    data[-1]);
800 		goto reject;
801 	case 0x7D:		/* Status message */
802 		break;
803 	default:
804 		log(LOG_WARNING,
805 		    "nglmi: unexpected msg type(0x%x) \n", (int) type);
806 		goto reject;
807 	}
808 	STEPBY(1);
809 
810 	/* Now check if there is a 'locking shift'. This is only seen in
811 	 * Annex D frames. Don't increment immediately as it might not be
812 	 * there. */
813 	nextbyte = *data;
814 	if (sc->flags & SCF_AUTO) {
815 		if (!(GROUP4(sc))) {
816 			if (nextbyte == 0x95) {
817 				SETLMITYPE(sc, SCF_ANNEX_D);
818 				STEPBY(1);
819 			} else
820 				SETLMITYPE(sc, SCF_ANNEX_A);
821 		} else if (nextbyte == 0x95) {
822 			log(LOG_WARNING, "nglmi: locking shift seen in G4\n");
823 			goto reject;
824 		}
825 	} else {
826 		if (ANNEXD(sc)) {
827 			if (*data == 0x95)
828 				STEPBY(1);
829 			else {
830 				log(LOG_WARNING,
831 				    "nglmi: locking shift missing\n");
832 				goto reject;
833 			}
834 		} else if (*data == 0x95) {
835 			log(LOG_WARNING, "nglmi: locking shift seen\n");
836 			goto reject;
837 		}
838 	}
839 
840 	/* While there is more data in the status packet, keep processing
841 	 * status items. First make sure there is enough data for the
842 	 * segment descriptor's length field. */
843 	while (packetlen >= 2) {
844 		u_int   segtype = data[0];
845 		u_int   segsize = data[1];
846 
847 		/* Now that we know how long it claims to be, make sure
848 		 * there is enough data for the next seg. */
849 		if (packetlen < (segsize + 2)) {
850 			log(LOG_WARNING, "nglmi: IE longer than packet\n");
851 			break;
852 		}
853 		switch (segtype) {
854 		case 0x01:
855 		case 0x51:
856 			/* According to MCI's HP analyser, we should just
857 			 * ignore if there is mor ethan one of these (?). */
858 			if (resptype_seen) {
859 				log(LOG_WARNING, "nglmi: dup MSGTYPE\n");
860 				goto nextIE;
861 			}
862 			if (segsize != 1) {
863 				log(LOG_WARNING, "nglmi: MSGTYPE wrong size\n");
864 				goto reject;
865 			}
866 			/* The remote end tells us what kind of response
867 			 * this is. Only expect a type 0 or 1. if it was a
868 			 * full (type 0) check we just asked for a type
869 			 * full. */
870 			switch (data[2]) {
871 			case 1:/* partial */
872 				if (sc->livs > sc->liv_per_full) {
873 					log(LOG_WARNING,
874 					  "nglmi: LIV when FULL expected\n");
875 					goto reject;	/* need full */
876 				}
877 				resptype_seen = 1;
878 				break;
879 			case 0:/* full */
880 				/* Full response is always acceptable */
881 				resptype_seen = 2;
882 				break;
883 			default:
884 				log(LOG_WARNING,
885 				 "nglmi: Unknown report type %d\n", data[2]);
886 				goto reject;
887 			}
888 			break;
889 		case 0x03:
890 		case 0x53:
891 			/* The remote tells us what it thinks the sequence
892 			 * numbers are. I would have thought that there
893 			 * needs to be one and only one of these, but MCI
894 			 * want us to just ignore extras. (?) */
895 			if (resptype_seen == 0) {
896 				log(LOG_WARNING, "nglmi: no TYPE before SEQ\n");
897 				goto reject;
898 			}
899 			if (seq_seen != 0)	/* already seen seq numbers */
900 				goto nextIE;
901 			if (segsize != 2) {
902 				log(LOG_WARNING, "nglmi: bad SEQ sts size\n");
903 				goto reject;
904 			}
905 			if (sc->local_seq != data[3]) {
906 				log(LOG_WARNING, "nglmi: unexpected SEQ\n");
907 				goto reject;
908 			}
909 			seq_seen = 1;
910 			break;
911 		case 0x07:
912 		case 0x57:
913 			/* The remote tells us about a DLCI that it knows
914 			 * about. There may be many of these in a single
915 			 * status response */
916 			if (seq_seen != 1) {	/* already seen seq numbers? */
917 				log(LOG_WARNING,
918 				    "nglmi: No sequence before DLCI\n");
919 				goto reject;
920 			}
921 			if (resptype_seen != 2) {	/* must be full */
922 				log(LOG_WARNING,
923 				    "nglmi: No resp type before DLCI\n");
924 				goto reject;
925 			}
926 			if (GROUP4(sc)) {
927 				if (segsize != 6) {
928 					log(LOG_WARNING,
929 					    "nglmi: wrong IE segsize\n");
930 					goto reject;
931 				}
932 				dlci = ((u_short) data[2] & 0xff) << 8;
933 				dlci |= (data[3] & 0xff);
934 			} else {
935 				if (segsize != 3) {
936 					log(LOG_WARNING,
937 					    "nglmi: DLCI headersize of %d"
938 					    " not supported\n", segsize - 1);
939 					goto reject;
940 				}
941 				dlci = ((u_short) data[2] & 0x3f) << 4;
942 				dlci |= ((data[3] & 0x78) >> 3);
943 			}
944 			/* async can only have one of these */
945 #if 0				/* async not yet accepted */
946 			if (async && highest_dlci) {
947 				log(LOG_WARNING,
948 				    "nglmi: Async with > 1 DLCI\n");
949 				goto reject;
950 			}
951 #endif
952 			/* Annex D says these will always be Ascending, but
953 			 * the HP test for G4 says we should accept
954 			 * duplicates, so for now allow that. ( <= vs. < ) */
955 #if 0
956 			/* MCI tests want us to accept out of order for AnxD */
957 			if ((!GROUP4(sc)) && (dlci < highest_dlci)) {
958 				/* duplicate or mis-ordered dlci */
959 				/* (spec says they will increase in number) */
960 				log(LOG_WARNING, "nglmi: DLCI out of order\n");
961 				goto reject;
962 			}
963 #endif
964 			if (dlci > 1023) {
965 				log(LOG_WARNING, "nglmi: DLCI out of range\n");
966 				goto reject;
967 			}
968 			highest_dlci = dlci;
969 			break;
970 		default:
971 			log(LOG_WARNING,
972 			    "nglmi: unknown LMI segment type %d\n", segtype);
973 		}
974 nextIE:
975 		STEPBY(segsize + 2);
976 	}
977 	if (packetlen != 0) {	/* partial junk at end? */
978 		log(LOG_WARNING,
979 		    "nglmi: %d bytes extra at end of packet\n", packetlen);
980 		goto print;
981 	}
982 	if (resptype_seen == 0) {
983 		log(LOG_WARNING, "nglmi: No response type seen\n");
984 		goto reject;	/* had no response type */
985 	}
986 	if (seq_seen == 0) {
987 		log(LOG_WARNING, "nglmi: No sequence numbers seen\n");
988 		goto reject;	/* had no sequence numbers */
989 	}
990 	return (1);
991 
992 print:
993 	{
994 		int     i, j, k, pos;
995 		char    buf[100];
996 		int     loc;
997 		const	u_char *bp = mtod(m, const u_char *);
998 
999 		k = i = 0;
1000 		loc = (m->m_hdr.mh_len - packetlen);
1001 		log(LOG_WARNING, "nglmi: error at location %d\n", loc);
1002 		while (k < m->m_hdr.mh_len) {
1003 			pos = 0;
1004 			j = 0;
1005 			while ((j++ < 16) && k < m->m_hdr.mh_len) {
1006 				pos += sprintf(buf + pos, "%c%02x",
1007 					       ((loc == k) ? '>' : ' '),
1008 					       bp[k]);
1009 				k++;
1010 			}
1011 			if (i == 0)
1012 				log(LOG_WARNING, "nglmi: packet data:%s\n", buf);
1013 			else
1014 				log(LOG_WARNING, "%04d              :%s\n", k, buf);
1015 			i++;
1016 		}
1017 	}
1018 	return (1);
1019 reject:
1020 	{
1021 		int     i, j, k, pos;
1022 		char    buf[100];
1023 		int     loc;
1024 		const	u_char *bp = mtod(m, const u_char *);
1025 
1026 		k = i = 0;
1027 		loc = (m->m_hdr.mh_len - packetlen);
1028 		log(LOG_WARNING, "nglmi: error at location %d\n", loc);
1029 		while (k < m->m_hdr.mh_len) {
1030 			pos = 0;
1031 			j = 0;
1032 			while ((j++ < 16) && k < m->m_hdr.mh_len) {
1033 				pos += sprintf(buf + pos, "%c%02x",
1034 					       ((loc == k) ? '>' : ' '),
1035 					       bp[k]);
1036 				k++;
1037 			}
1038 			if (i == 0)
1039 				log(LOG_WARNING, "nglmi: packet data:%s\n", buf);
1040 			else
1041 				log(LOG_WARNING, "%04d              :%s\n", k, buf);
1042 			i++;
1043 		}
1044 	}
1045 	NG_FREE_M(m);
1046 	return (0);
1047 }
1048 
1049 /*
1050  * Do local shutdown processing..
1051  * Cut any remaining links and free our local resources.
1052  */
1053 static int
1054 nglmi_shutdown(node_p node)
1055 {
1056 	const sc_p sc = NG_NODE_PRIVATE(node);
1057 
1058 	NG_NODE_SET_PRIVATE(node, NULL);
1059 	NG_NODE_UNREF(sc->node);
1060 	FREE(sc, M_NETGRAPH);
1061 	return (0);
1062 }
1063 
1064 /*
1065  * Hook disconnection
1066  * For this type, removal of any link except "debug" destroys the node.
1067  */
1068 static int
1069 nglmi_disconnect(hook_p hook)
1070 {
1071 	const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
1072 
1073 	/* OK to remove debug hook(s) */
1074 	if (NG_HOOK_PRIVATE(hook) == NULL)
1075 		return (0);
1076 
1077 	/* Stop timer if it's currently active */
1078 	if (sc->flags & SCF_CONNECTED)
1079 		untimeout(LMI_ticker, sc, sc->handle);
1080 
1081 	/* Self-destruct */
1082 	if (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
1083 		ng_rmnode_self(NG_HOOK_NODE(hook));
1084 	return (0);
1085 }
1086 
1087