xref: /dragonfly/sys/netgraph7/lmi/ng_lmi.c (revision fb151170)
1 /*
2  * ng_lmi.c
3  */
4 
5 /*-
6  * Copyright (c) 1996-1999 Whistle Communications, Inc.
7  * All rights reserved.
8  *
9  * Subject to the following obligations and disclaimer of warranty, use and
10  * redistribution of this software, in source or object code forms, with or
11  * without modifications are expressly permitted by Whistle Communications;
12  * provided, however, that:
13  * 1. Any and all reproductions of the source or object code must include the
14  *    copyright notice above and the following disclaimer of warranties; and
15  * 2. No rights are granted, in any manner or form, to use Whistle
16  *    Communications, Inc. trademarks, including the mark "WHISTLE
17  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
18  *    such appears in the above copyright notice or in the software.
19  *
20  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
21  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
22  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
23  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
24  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
25  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
26  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
27  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
28  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
29  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
30  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
31  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
32  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
36  * OF SUCH DAMAGE.
37  *
38  * Author: Julian Elischer <julian@freebsd.org>
39  *
40  * $FreeBSD: src/sys/netgraph/ng_lmi.c,v 1.25 2006/01/14 14:17:27 glebius Exp $
41  * $DragonFly: src/sys/netgraph7/ng_lmi.c,v 1.2 2008/06/26 23:05:35 dillon Exp $
42  * $Whistle: ng_lmi.c,v 1.38 1999/11/01 09:24:52 julian Exp $
43  */
44 
45 /*
46  * This node performs the frame relay LMI protocol. It knows how
47  * to do ITU Annex A, ANSI Annex D, and "Group-of-Four" variants
48  * of the protocol.
49  *
50  * A specific protocol can be forced by connecting the corresponding
51  * hook to DLCI 0 or 1023 (as appropriate) of a frame relay link.
52  *
53  * Alternately, this node can do auto-detection of the LMI protocol
54  * by connecting hook "auto0" to DLCI 0 and "auto1023" to DLCI 1023.
55  */
56 
57 #include <sys/param.h>
58 #include <sys/systm.h>
59 #include <sys/errno.h>
60 #include <sys/kernel.h>
61 #include <sys/malloc.h>
62 #include <sys/mbuf.h>
63 #include <sys/syslog.h>
64 #include <netgraph7/ng_message.h>
65 #include <netgraph7/netgraph.h>
66 #include "ng_lmi.h"
67 
68 /*
69  * Human readable names for LMI
70  */
71 #define NAME_ANNEXA	NG_LMI_HOOK_ANNEXA
72 #define NAME_ANNEXD	NG_LMI_HOOK_ANNEXD
73 #define NAME_GROUP4	NG_LMI_HOOK_GROUPOF4
74 #define NAME_NONE	"None"
75 
76 #define MAX_DLCIS	128
77 #define MAXDLCI		1023
78 
79 /*
80  * DLCI states
81  */
82 #define DLCI_NULL	0
83 #define DLCI_UP		1
84 #define DLCI_DOWN	2
85 
86 /*
87  * Any received LMI frame should be at least this long
88  */
89 #define LMI_MIN_LENGTH	8	/* XXX verify */
90 
91 /*
92  * Netgraph node methods and type descriptor
93  */
94 static ng_constructor_t	nglmi_constructor;
95 static ng_rcvmsg_t	nglmi_rcvmsg;
96 static ng_shutdown_t	nglmi_shutdown;
97 static ng_newhook_t	nglmi_newhook;
98 static ng_rcvdata_t	nglmi_rcvdata;
99 static ng_disconnect_t	nglmi_disconnect;
100 static int	nglmi_checkdata(hook_p hook, struct mbuf *m);
101 
102 static struct ng_type typestruct = {
103 	.version =	NG_ABI_VERSION,
104 	.name =		NG_LMI_NODE_TYPE,
105 	.constructor =	nglmi_constructor,
106 	.rcvmsg	=	nglmi_rcvmsg,
107 	.shutdown =	nglmi_shutdown,
108 	.newhook =	nglmi_newhook,
109 	.rcvdata =	nglmi_rcvdata,
110 	.disconnect =	nglmi_disconnect,
111 };
112 NETGRAPH_INIT(lmi, &typestruct);
113 
114 /*
115  * Info and status per node
116  */
117 struct nglmi_softc {
118 	node_p  node;		/* netgraph node */
119 	int     flags;		/* state */
120 	int     poll_count;	/* the count of times for autolmi */
121 	int     poll_state;	/* state of auto detect machine */
122 	u_char  remote_seq;	/* sequence number the remote sent */
123 	u_char  local_seq;	/* last sequence number we sent */
124 	u_char  protoID;	/* 9 for group of 4, 8 otherwise */
125 	u_long  seq_retries;	/* sent this how many time so far */
126 	struct	callout	handle;	/* see timeout(9) */
127 	int     liv_per_full;
128 	int     liv_rate;
129 	int     livs;
130 	int     need_full;
131 	hook_p  lmi_channel;	/* whatever we ended up using */
132 	hook_p  lmi_annexA;
133 	hook_p  lmi_annexD;
134 	hook_p  lmi_group4;
135 	hook_p  lmi_channel0;	/* auto-detect on DLCI 0 */
136 	hook_p  lmi_channel1023;/* auto-detect on DLCI 1023 */
137 	char   *protoname;	/* cache protocol name */
138 	u_char  dlci_state[MAXDLCI + 1];
139 	int     invalidx;	/* next dlci's to invalidate */
140 };
141 typedef struct nglmi_softc *sc_p;
142 
143 /*
144  * Other internal functions
145  */
146 static void	LMI_ticker(node_p node, hook_p hook, void *arg1, int arg2);
147 static void	nglmi_startup_fixed(sc_p sc, hook_p hook);
148 static void	nglmi_startup_auto(sc_p sc);
149 static void	nglmi_startup(sc_p sc);
150 static void	nglmi_inquire(sc_p sc, int full);
151 static void	ngauto_state_machine(sc_p sc);
152 
153 /*
154  * Values for 'flags' field
155  * NB: the SCF_CONNECTED flag is set if and only if the timer is running.
156  */
157 #define	SCF_CONNECTED	0x01	/* connected to something */
158 #define	SCF_AUTO	0x02	/* we are auto-detecting */
159 #define	SCF_FIXED	0x04	/* we are fixed from the start */
160 
161 #define	SCF_LMITYPE	0x18	/* mask for determining Annex mode */
162 #define	SCF_NOLMI	0x00	/* no LMI type selected yet */
163 #define	SCF_ANNEX_A	0x08	/* running annex A mode */
164 #define	SCF_ANNEX_D	0x10	/* running annex D mode */
165 #define	SCF_GROUP4	0x18	/* running group of 4 */
166 
167 #define SETLMITYPE(sc, annex)						\
168 do {									\
169 	(sc)->flags &= ~SCF_LMITYPE;					\
170 	(sc)->flags |= (annex);						\
171 } while (0)
172 
173 #define NOPROTO(sc) (((sc)->flags & SCF_LMITYPE) == SCF_NOLMI)
174 #define ANNEXA(sc) (((sc)->flags & SCF_LMITYPE) == SCF_ANNEX_A)
175 #define ANNEXD(sc) (((sc)->flags & SCF_LMITYPE) == SCF_ANNEX_D)
176 #define GROUP4(sc) (((sc)->flags & SCF_LMITYPE) == SCF_GROUP4)
177 
178 #define LMIPOLLSIZE	3
179 #define LMI_PATIENCE	8	/* declare all DLCI DOWN after N LMI failures */
180 
181 /*
182  * Node constructor
183  */
184 static int
185 nglmi_constructor(node_p node)
186 {
187 	sc_p sc;
188 
189 	sc = kmalloc(sizeof(*sc), M_NETGRAPH, M_WAITOK | M_NULLOK | M_ZERO);
190 	if (sc == NULL)
191 		return (ENOMEM);
192 
193 	NG_NODE_SET_PRIVATE(node, sc);
194 	sc->node = node;
195 
196 	ng_callout_init(&sc->handle);
197 	sc->protoname = NAME_NONE;
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(node_p node, hook_p hook, void *arg1, int arg2)
266 {
267 	sc_p sc = NG_NODE_PRIVATE(node);
268 
269 	if (sc->flags & SCF_AUTO) {
270 		ngauto_state_machine(sc);
271 		ng_callout(&sc->handle, node, NULL, NG_LMI_POLL_RATE * hz,
272 		    LMI_ticker, NULL, 0);
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 		ng_callout(&sc->handle, node, NULL, sc->liv_rate * hz,
281 		    LMI_ticker, NULL, 0);
282 	}
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 	ng_callout(&sc->handle, sc->node, NULL, hz, LMI_ticker, NULL, 0);
311 }
312 
313 static void
314 nglmi_inquire(sc_p sc, int full)
315 {
316 	struct mbuf *m;
317 	struct ng_tag_prio *ptag;
318 	char   *cptr, *start;
319 	int     error;
320 
321 	if (sc->lmi_channel == NULL)
322 		return;
323 	MGETHDR(m, MB_DONTWAIT, MT_DATA);
324 	if (m == NULL) {
325 		log(LOG_ERR, "nglmi: unable to start up LMI processing\n");
326 		return;
327 	}
328 	m->m_pkthdr.rcvif = NULL;
329 
330 	/* Attach a tag to packet, marking it of link level state priority, so
331 	 * that device driver would put it in the beginning of queue */
332 
333 	ptag = (struct ng_tag_prio *)m_tag_alloc(NGM_GENERIC_COOKIE, NG_TAG_PRIO,
334 	    (sizeof(struct ng_tag_prio) - sizeof(struct m_tag)), MB_DONTWAIT);
335 	if (ptag != NULL) {	/* if it failed, well, it was optional anyhow */
336 		ptag->priority = NG_PRIO_LINKSTATE;
337 		ptag->discardability = -1;
338 		m_tag_prepend(m, &ptag->tag);
339 	}
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, add locking shift to codeset 5. */
353 	if (ANNEXD(sc))
354 		*cptr++ = 0x95;	/* locking shift */
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_ONLY(error, sc->lmi_channel, m);
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_WAITOK | M_NULLOK);
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_WAITOK | M_NULLOK);
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 	struct mbuf *m;
564 
565 	NGI_GET_M(item, m);
566 	NG_FREE_ITEM(item);
567 	if (NG_HOOK_PRIVATE(hook) == NULL) {
568 		goto drop;
569 	}
570 	packetlen = m->m_len;
571 
572 	/* XXX what if it's more than 1 mbuf? */
573 	if ((packetlen > MHLEN) && !(m->m_flags & M_EXT)) {
574 		log(LOG_WARNING, "nglmi: packetlen (%d) too big\n", packetlen);
575 		goto drop;
576 	}
577 	if (m->m_len < packetlen && (m = m_pullup(m, packetlen)) == NULL) {
578 		log(LOG_WARNING,
579 		    "nglmi: m_pullup failed for %d bytes\n", packetlen);
580 		return (0);
581 	}
582 	if (nglmi_checkdata(hook, m) == 0)
583 		return (0);
584 
585 	/* pass the first 4 bytes (already checked in the nglmi_checkdata()) */
586 	data = mtod(m, const u_char *);
587 	STEPBY(4);
588 
589 	/* Now check if there is a 'locking shift'. This is only seen in
590 	 * Annex D frames. don't bother checking, we already did that. Don't
591 	 * increment immediatly as it might not be there. */
592 	if (ANNEXD(sc))
593 		STEPBY(1);
594 
595 	/* If we get this far we should consider that it is a legitimate
596 	 * frame and we know what it is. */
597 	if (sc->flags & SCF_AUTO) {
598 		/* note the hook that this valid channel came from and drop
599 		 * out of auto probe mode. */
600 		if (ANNEXA(sc))
601 			sc->protoname = NAME_ANNEXA;
602 		else if (ANNEXD(sc))
603 			sc->protoname = NAME_ANNEXD;
604 		else if (GROUP4(sc))
605 			sc->protoname = NAME_GROUP4;
606 		else {
607 			log(LOG_ERR, "nglmi: No known type\n");
608 			goto drop;
609 		}
610 		sc->lmi_channel = hook;
611 		sc->flags &= ~SCF_AUTO;
612 		log(LOG_INFO, "nglmi: auto-detected %s LMI on DLCI %d\n",
613 		    sc->protoname, hook == sc->lmi_channel0 ? 0 : 1023);
614 	}
615 
616 	/* While there is more data in the status packet, keep processing
617 	 * status items. First make sure there is enough data for the
618 	 * segment descriptor's length field. */
619 	while (packetlen >= 2) {
620 		u_int   segtype = data[0];
621 		u_int   segsize = data[1];
622 
623 		/* Now that we know how long it claims to be, make sure
624 		 * there is enough data for the next seg. */
625 		if (packetlen < segsize + 2)
626 			break;
627 		switch (segtype) {
628 		case 0x01:
629 		case 0x51:
630 			if (resptype_seen) {
631 				log(LOG_WARNING, "nglmi: dup MSGTYPE\n");
632 				goto nextIE;
633 			}
634 			resptype_seen++;
635 			/* The remote end tells us what kind of response
636 			 * this is. Only expect a type 0 or 1. if we are a
637 			 * full status, invalidate a few DLCIs just to see
638 			 * that they are still ok. */
639 			if (segsize != 1)
640 				goto nextIE;
641 			switch (data[2]) {
642 			case 1:
643 				/* partial status, do no extra processing */
644 				break;
645 			case 0:
646 			    {
647 				int     count = 0;
648 				int     idx = sc->invalidx;
649 
650 				for (count = 0; count < 10; count++) {
651 					if (idx > MAXDLCI)
652 						idx = 0;
653 					if (sc->dlci_state[idx] == DLCI_UP)
654 						sc->dlci_state[idx] = DLCI_DOWN;
655 					idx++;
656 				}
657 				sc->invalidx = idx;
658 				/* we got and we wanted one. relax
659 				 * now.. but don't reset to 0 if it
660 				 * was unrequested. */
661 				if (sc->livs > sc->liv_per_full)
662 					sc->livs = 0;
663 				break;
664 			    }
665 			}
666 			break;
667 		case 0x03:
668 		case 0x53:
669 			/* The remote tells us what it thinks the sequence
670 			 * numbers are. If it's not size 2, it must be a
671 			 * duplicate to have gotten this far, skip it. */
672 			if (segsize != 2)
673 				goto nextIE;
674 			sc->remote_seq = data[2];
675 			if (sc->local_seq == data[3]) {
676 				sc->local_seq++;
677 				sc->seq_retries = 0;
678 				/* Note that all 3 Frame protocols seem to
679 				 * not like 0 as a sequence number. */
680 				if (sc->local_seq == 0)
681 					sc->local_seq = 1;
682 			}
683 			break;
684 		case 0x07:
685 		case 0x57:
686 			/* The remote tells us about a DLCI that it knows
687 			 * about. There may be many of these in a single
688 			 * status response */
689 			switch (segsize) {
690 			case 6:/* only on 'group of 4' */
691 				dlci = ((u_short) data[2] & 0xff) << 8;
692 				dlci |= (data[3] & 0xff);
693 				if ((dlci < 1024) && (dlci > 0)) {
694 				  /* XXX */
695 				}
696 				break;
697 			case 3:
698 				dlci = ((u_short) data[2] & 0x3f) << 4;
699 				dlci |= ((data[3] & 0x78) >> 3);
700 				if ((dlci < 1024) && (dlci > 0)) {
701 					/* set up the bottom half of the
702 					 * support for that dlci if it's not
703 					 * already been done */
704 					/* store this information somewhere */
705 				}
706 				break;
707 			default:
708 				goto nextIE;
709 			}
710 			if (sc->dlci_state[dlci] != DLCI_UP) {
711 				/* bring new DLCI to life */
712 				/* may do more here some day */
713 				if (sc->dlci_state[dlci] != DLCI_DOWN)
714 					log(LOG_INFO,
715 					    "nglmi: DLCI %d became active\n",
716 					    dlci);
717 				sc->dlci_state[dlci] = DLCI_UP;
718 			}
719 			break;
720 		}
721 nextIE:
722 		STEPBY(segsize + 2);
723 	}
724 	NG_FREE_M(m);
725 	return (0);
726 
727 drop:
728 	NG_FREE_M(m);
729 	return (EINVAL);
730 }
731 
732 /*
733  * Check that a packet is entirely kosha.
734  * return 1 of ok, and 0 if not.
735  * All data is discarded if a 0 is returned.
736  */
737 static int
738 nglmi_checkdata(hook_p hook, struct mbuf *m)
739 {
740 	sc_p    sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
741 	const	u_char *data;
742 	u_short packetlen;
743 	unsigned short dlci;
744 	u_char  type;
745 	u_char  nextbyte;
746 	int     seq_seen = 0;
747 	int     resptype_seen = 0;	/* 0 , 1 (partial) or 2 (full) */
748 	int     highest_dlci = 0;
749 
750 	packetlen = m->m_len;
751 	data = mtod(m, const u_char *);
752 	if (*data != 0x03) {
753 		log(LOG_WARNING, "nglmi: unexpected value in LMI(%d)\n", 1);
754 		goto reject;
755 	}
756 	STEPBY(1);
757 
758 	/* look at the protocol ID */
759 	nextbyte = *data;
760 	if (sc->flags & SCF_AUTO) {
761 		SETLMITYPE(sc, SCF_NOLMI);	/* start with a clean slate */
762 		switch (nextbyte) {
763 		case 0x8:
764 			sc->protoID = 8;
765 			break;
766 		case 0x9:
767 			SETLMITYPE(sc, SCF_GROUP4);
768 			sc->protoID = 9;
769 			break;
770 		default:
771 			log(LOG_WARNING, "nglmi: bad Protocol ID(%d)\n",
772 			    (int) nextbyte);
773 			goto reject;
774 		}
775 	} else {
776 		if (nextbyte != sc->protoID) {
777 			log(LOG_WARNING, "nglmi: unexpected Protocol ID(%d)\n",
778 			    (int) nextbyte);
779 			goto reject;
780 		}
781 	}
782 	STEPBY(1);
783 
784 	/* check call reference (always null in non ISDN frame relay) */
785 	if (*data != 0x00) {
786 		log(LOG_WARNING, "nglmi: unexpected Call Reference (0x%x)\n",
787 		    data[-1]);
788 		goto reject;
789 	}
790 	STEPBY(1);
791 
792 	/* check message type */
793 	switch ((type = *data)) {
794 	case 0x75:		/* Status enquiry */
795 		log(LOG_WARNING, "nglmi: unexpected message type(0x%x)\n",
796 		    data[-1]);
797 		goto reject;
798 	case 0x7D:		/* Status message */
799 		break;
800 	default:
801 		log(LOG_WARNING,
802 		    "nglmi: unexpected msg type(0x%x) \n", (int) type);
803 		goto reject;
804 	}
805 	STEPBY(1);
806 
807 	/* Now check if there is a 'locking shift'. This is only seen in
808 	 * Annex D frames. Don't increment immediately as it might not be
809 	 * there. */
810 	nextbyte = *data;
811 	if (sc->flags & SCF_AUTO) {
812 		if (!(GROUP4(sc))) {
813 			if (nextbyte == 0x95) {
814 				SETLMITYPE(sc, SCF_ANNEX_D);
815 				STEPBY(1);
816 			} else
817 				SETLMITYPE(sc, SCF_ANNEX_A);
818 		} else if (nextbyte == 0x95) {
819 			log(LOG_WARNING, "nglmi: locking shift seen in G4\n");
820 			goto reject;
821 		}
822 	} else {
823 		if (ANNEXD(sc)) {
824 			if (*data == 0x95)
825 				STEPBY(1);
826 			else {
827 				log(LOG_WARNING,
828 				    "nglmi: locking shift missing\n");
829 				goto reject;
830 			}
831 		} else if (*data == 0x95) {
832 			log(LOG_WARNING, "nglmi: locking shift seen\n");
833 			goto reject;
834 		}
835 	}
836 
837 	/* While there is more data in the status packet, keep processing
838 	 * status items. First make sure there is enough data for the
839 	 * segment descriptor's length field. */
840 	while (packetlen >= 2) {
841 		u_int   segtype = data[0];
842 		u_int   segsize = data[1];
843 
844 		/* Now that we know how long it claims to be, make sure
845 		 * there is enough data for the next seg. */
846 		if (packetlen < (segsize + 2)) {
847 			log(LOG_WARNING, "nglmi: IE longer than packet\n");
848 			break;
849 		}
850 		switch (segtype) {
851 		case 0x01:
852 		case 0x51:
853 			/* According to MCI's HP analyser, we should just
854 			 * ignore if there is mor ethan one of these (?). */
855 			if (resptype_seen) {
856 				log(LOG_WARNING, "nglmi: dup MSGTYPE\n");
857 				goto nextIE;
858 			}
859 			if (segsize != 1) {
860 				log(LOG_WARNING, "nglmi: MSGTYPE wrong size\n");
861 				goto reject;
862 			}
863 			/* The remote end tells us what kind of response
864 			 * this is. Only expect a type 0 or 1. if it was a
865 			 * full (type 0) check we just asked for a type
866 			 * full. */
867 			switch (data[2]) {
868 			case 1:/* partial */
869 				if (sc->livs > sc->liv_per_full) {
870 					log(LOG_WARNING,
871 					  "nglmi: LIV when FULL expected\n");
872 					goto reject;	/* need full */
873 				}
874 				resptype_seen = 1;
875 				break;
876 			case 0:/* full */
877 				/* Full response is always acceptable */
878 				resptype_seen = 2;
879 				break;
880 			default:
881 				log(LOG_WARNING,
882 				 "nglmi: Unknown report type %d\n", data[2]);
883 				goto reject;
884 			}
885 			break;
886 		case 0x03:
887 		case 0x53:
888 			/* The remote tells us what it thinks the sequence
889 			 * numbers are. I would have thought that there
890 			 * needs to be one and only one of these, but MCI
891 			 * want us to just ignore extras. (?) */
892 			if (resptype_seen == 0) {
893 				log(LOG_WARNING, "nglmi: no TYPE before SEQ\n");
894 				goto reject;
895 			}
896 			if (seq_seen != 0)	/* already seen seq numbers */
897 				goto nextIE;
898 			if (segsize != 2) {
899 				log(LOG_WARNING, "nglmi: bad SEQ sts size\n");
900 				goto reject;
901 			}
902 			if (sc->local_seq != data[3]) {
903 				log(LOG_WARNING, "nglmi: unexpected SEQ\n");
904 				goto reject;
905 			}
906 			seq_seen = 1;
907 			break;
908 		case 0x07:
909 		case 0x57:
910 			/* The remote tells us about a DLCI that it knows
911 			 * about. There may be many of these in a single
912 			 * status response */
913 			if (seq_seen != 1) {	/* already seen seq numbers? */
914 				log(LOG_WARNING,
915 				    "nglmi: No sequence before DLCI\n");
916 				goto reject;
917 			}
918 			if (resptype_seen != 2) {	/* must be full */
919 				log(LOG_WARNING,
920 				    "nglmi: No resp type before DLCI\n");
921 				goto reject;
922 			}
923 			if (GROUP4(sc)) {
924 				if (segsize != 6) {
925 					log(LOG_WARNING,
926 					    "nglmi: wrong IE segsize\n");
927 					goto reject;
928 				}
929 				dlci = ((u_short) data[2] & 0xff) << 8;
930 				dlci |= (data[3] & 0xff);
931 			} else {
932 				if (segsize != 3) {
933 					log(LOG_WARNING,
934 					    "nglmi: DLCI headersize of %d"
935 					    " not supported\n", segsize - 1);
936 					goto reject;
937 				}
938 				dlci = ((u_short) data[2] & 0x3f) << 4;
939 				dlci |= ((data[3] & 0x78) >> 3);
940 			}
941 			/* async can only have one of these */
942 #if 0				/* async not yet accepted */
943 			if (async && highest_dlci) {
944 				log(LOG_WARNING,
945 				    "nglmi: Async with > 1 DLCI\n");
946 				goto reject;
947 			}
948 #endif
949 			/* Annex D says these will always be Ascending, but
950 			 * the HP test for G4 says we should accept
951 			 * duplicates, so for now allow that. ( <= vs. < ) */
952 #if 0
953 			/* MCI tests want us to accept out of order for AnxD */
954 			if ((!GROUP4(sc)) && (dlci < highest_dlci)) {
955 				/* duplicate or mis-ordered dlci */
956 				/* (spec says they will increase in number) */
957 				log(LOG_WARNING, "nglmi: DLCI out of order\n");
958 				goto reject;
959 			}
960 #endif
961 			if (dlci > 1023) {
962 				log(LOG_WARNING, "nglmi: DLCI out of range\n");
963 				goto reject;
964 			}
965 			highest_dlci = dlci;
966 			break;
967 		default:
968 			log(LOG_WARNING,
969 			    "nglmi: unknown LMI segment type %d\n", segtype);
970 		}
971 nextIE:
972 		STEPBY(segsize + 2);
973 	}
974 	if (packetlen != 0) {	/* partial junk at end? */
975 		log(LOG_WARNING,
976 		    "nglmi: %d bytes extra at end of packet\n", packetlen);
977 		goto print;
978 	}
979 	if (resptype_seen == 0) {
980 		log(LOG_WARNING, "nglmi: No response type seen\n");
981 		goto reject;	/* had no response type */
982 	}
983 	if (seq_seen == 0) {
984 		log(LOG_WARNING, "nglmi: No sequence numbers seen\n");
985 		goto reject;	/* had no sequence numbers */
986 	}
987 	return (1);
988 
989 print:
990 	{
991 		int     i, j, k, pos;
992 		char    buf[100];
993 		int     loc;
994 		const	u_char *bp = mtod(m, const u_char *);
995 
996 		k = i = 0;
997 		loc = (m->m_len - packetlen);
998 		log(LOG_WARNING, "nglmi: error at location %d\n", loc);
999 		while (k < m->m_len) {
1000 			pos = 0;
1001 			j = 0;
1002 			while ((j++ < 16) && k < m->m_len) {
1003 				pos += sprintf(buf + pos, "%c%02x",
1004 					       ((loc == k) ? '>' : ' '),
1005 					       bp[k]);
1006 				k++;
1007 			}
1008 			if (i == 0)
1009 				log(LOG_WARNING, "nglmi: packet data:%s\n", buf);
1010 			else
1011 				log(LOG_WARNING, "%04d              :%s\n", k, buf);
1012 			i++;
1013 		}
1014 	}
1015 	return (1);
1016 reject:
1017 	{
1018 		int     i, j, k, pos;
1019 		char    buf[100];
1020 		int     loc;
1021 		const	u_char *bp = mtod(m, const u_char *);
1022 
1023 		k = i = 0;
1024 		loc = (m->m_len - packetlen);
1025 		log(LOG_WARNING, "nglmi: error at location %d\n", loc);
1026 		while (k < m->m_len) {
1027 			pos = 0;
1028 			j = 0;
1029 			while ((j++ < 16) && k < m->m_len) {
1030 				pos += sprintf(buf + pos, "%c%02x",
1031 					       ((loc == k) ? '>' : ' '),
1032 					       bp[k]);
1033 				k++;
1034 			}
1035 			if (i == 0)
1036 				log(LOG_WARNING, "nglmi: packet data:%s\n", buf);
1037 			else
1038 				log(LOG_WARNING, "%04d              :%s\n", k, buf);
1039 			i++;
1040 		}
1041 	}
1042 	NG_FREE_M(m);
1043 	return (0);
1044 }
1045 
1046 /*
1047  * Do local shutdown processing..
1048  * Cut any remaining links and free our local resources.
1049  */
1050 static int
1051 nglmi_shutdown(node_p node)
1052 {
1053 	const sc_p sc = NG_NODE_PRIVATE(node);
1054 
1055 	NG_NODE_SET_PRIVATE(node, NULL);
1056 	NG_NODE_UNREF(sc->node);
1057 	kfree(sc, M_NETGRAPH);
1058 	return (0);
1059 }
1060 
1061 /*
1062  * Hook disconnection
1063  * For this type, removal of any link except "debug" destroys the node.
1064  */
1065 static int
1066 nglmi_disconnect(hook_p hook)
1067 {
1068 	const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
1069 
1070 	/* OK to remove debug hook(s) */
1071 	if (NG_HOOK_PRIVATE(hook) == NULL)
1072 		return (0);
1073 
1074 	/* Stop timer if it's currently active */
1075 	if (sc->flags & SCF_CONNECTED)
1076 		ng_uncallout(&sc->handle, sc->node);
1077 
1078 	/* Self-destruct */
1079 	if (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
1080 		ng_rmnode_self(NG_HOOK_NODE(hook));
1081 	return (0);
1082 }
1083 
1084