ng_lmi.c revision 184205
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: head/sys/netgraph/ng_lmi.c 184205 2008-10-23 15:53:51Z des $
41 * $Whistle: ng_lmi.c,v 1.38 1999/11/01 09:24:52 julian Exp $
42 */
43
44/*
45 * This node performs the frame relay LMI protocol. It knows how
46 * to do ITU Annex A, ANSI Annex D, and "Group-of-Four" variants
47 * of the protocol.
48 *
49 * A specific protocol can be forced by connecting the corresponding
50 * hook to DLCI 0 or 1023 (as appropriate) of a frame relay link.
51 *
52 * Alternately, this node can do auto-detection of the LMI protocol
53 * by connecting hook "auto0" to DLCI 0 and "auto1023" to DLCI 1023.
54 */
55
56#include <sys/param.h>
57#include <sys/systm.h>
58#include <sys/errno.h>
59#include <sys/kernel.h>
60#include <sys/malloc.h>
61#include <sys/mbuf.h>
62#include <sys/syslog.h>
63#include <netgraph/ng_message.h>
64#include <netgraph/netgraph.h>
65#include <netgraph/ng_lmi.h>
66
67/*
68 * Human readable names for LMI
69 */
70#define NAME_ANNEXA	NG_LMI_HOOK_ANNEXA
71#define NAME_ANNEXD	NG_LMI_HOOK_ANNEXD
72#define NAME_GROUP4	NG_LMI_HOOK_GROUPOF4
73#define NAME_NONE	"None"
74
75#define MAX_DLCIS	128
76#define MAXDLCI		1023
77
78/*
79 * DLCI states
80 */
81#define DLCI_NULL	0
82#define DLCI_UP		1
83#define DLCI_DOWN	2
84
85/*
86 * Any received LMI frame should be at least this long
87 */
88#define LMI_MIN_LENGTH	8	/* XXX verify */
89
90/*
91 * Netgraph node methods and type descriptor
92 */
93static ng_constructor_t	nglmi_constructor;
94static ng_rcvmsg_t	nglmi_rcvmsg;
95static ng_shutdown_t	nglmi_shutdown;
96static ng_newhook_t	nglmi_newhook;
97static ng_rcvdata_t	nglmi_rcvdata;
98static ng_disconnect_t	nglmi_disconnect;
99static int	nglmi_checkdata(hook_p hook, struct mbuf *m);
100
101static struct ng_type typestruct = {
102	.version =	NG_ABI_VERSION,
103	.name =		NG_LMI_NODE_TYPE,
104	.constructor =	nglmi_constructor,
105	.rcvmsg	=	nglmi_rcvmsg,
106	.shutdown =	nglmi_shutdown,
107	.newhook =	nglmi_newhook,
108	.rcvdata =	nglmi_rcvdata,
109	.disconnect =	nglmi_disconnect,
110};
111NETGRAPH_INIT(lmi, &typestruct);
112
113/*
114 * Info and status per node
115 */
116struct nglmi_softc {
117	node_p  node;		/* netgraph node */
118	int     flags;		/* state */
119	int     poll_count;	/* the count of times for autolmi */
120	int     poll_state;	/* state of auto detect machine */
121	u_char  remote_seq;	/* sequence number the remote sent */
122	u_char  local_seq;	/* last sequence number we sent */
123	u_char  protoID;	/* 9 for group of 4, 8 otherwise */
124	u_long  seq_retries;	/* sent this how many time so far */
125	struct	callout	handle;	/* see timeout(9) */
126	int     liv_per_full;
127	int     liv_rate;
128	int     livs;
129	int     need_full;
130	hook_p  lmi_channel;	/* whatever we ended up using */
131	hook_p  lmi_annexA;
132	hook_p  lmi_annexD;
133	hook_p  lmi_group4;
134	hook_p  lmi_channel0;	/* auto-detect on DLCI 0 */
135	hook_p  lmi_channel1023;/* auto-detect on DLCI 1023 */
136	char   *protoname;	/* cache protocol name */
137	u_char  dlci_state[MAXDLCI + 1];
138	int     invalidx;	/* next dlci's to invalidate */
139};
140typedef struct nglmi_softc *sc_p;
141
142/*
143 * Other internal functions
144 */
145static void	LMI_ticker(node_p node, hook_p hook, void *arg1, int arg2);
146static void	nglmi_startup_fixed(sc_p sc, hook_p hook);
147static void	nglmi_startup_auto(sc_p sc);
148static void	nglmi_startup(sc_p sc);
149static void	nglmi_inquire(sc_p sc, int full);
150static void	ngauto_state_machine(sc_p sc);
151
152/*
153 * Values for 'flags' field
154 * NB: the SCF_CONNECTED flag is set if and only if the timer is running.
155 */
156#define	SCF_CONNECTED	0x01	/* connected to something */
157#define	SCF_AUTO	0x02	/* we are auto-detecting */
158#define	SCF_FIXED	0x04	/* we are fixed from the start */
159
160#define	SCF_LMITYPE	0x18	/* mask for determining Annex mode */
161#define	SCF_NOLMI	0x00	/* no LMI type selected yet */
162#define	SCF_ANNEX_A	0x08	/* running annex A mode */
163#define	SCF_ANNEX_D	0x10	/* running annex D mode */
164#define	SCF_GROUP4	0x18	/* running group of 4 */
165
166#define SETLMITYPE(sc, annex)						\
167do {									\
168	(sc)->flags &= ~SCF_LMITYPE;					\
169	(sc)->flags |= (annex);						\
170} while (0)
171
172#define NOPROTO(sc) (((sc)->flags & SCF_LMITYPE) == SCF_NOLMI)
173#define ANNEXA(sc) (((sc)->flags & SCF_LMITYPE) == SCF_ANNEX_A)
174#define ANNEXD(sc) (((sc)->flags & SCF_LMITYPE) == SCF_ANNEX_D)
175#define GROUP4(sc) (((sc)->flags & SCF_LMITYPE) == SCF_GROUP4)
176
177#define LMIPOLLSIZE	3
178#define LMI_PATIENCE	8	/* declare all DLCI DOWN after N LMI failures */
179
180/*
181 * Node constructor
182 */
183static int
184nglmi_constructor(node_p node)
185{
186	sc_p sc;
187
188	sc = malloc(sizeof(*sc), M_NETGRAPH, M_NOWAIT | M_ZERO);
189	if (sc == NULL)
190		return (ENOMEM);
191
192	NG_NODE_SET_PRIVATE(node, sc);
193	sc->node = node;
194
195	ng_callout_init(&sc->handle);
196	sc->protoname = NAME_NONE;
197	sc->liv_per_full = NG_LMI_SEQ_PER_FULL;	/* make this dynamic */
198	sc->liv_rate = NG_LMI_KEEPALIVE_RATE;
199	return (0);
200}
201
202/*
203 * The LMI channel has a private pointer which is the same as the
204 * node private pointer. The debug channel has a NULL private pointer.
205 */
206static int
207nglmi_newhook(node_p node, hook_p hook, const char *name)
208{
209	sc_p sc = NG_NODE_PRIVATE(node);
210
211	if (strcmp(name, NG_LMI_HOOK_DEBUG) == 0) {
212		NG_HOOK_SET_PRIVATE(hook, NULL);
213		return (0);
214	}
215	if (sc->flags & SCF_CONNECTED) {
216		/* already connected, return an error */
217		return (EINVAL);
218	}
219	if (strcmp(name, NG_LMI_HOOK_ANNEXA) == 0) {
220		sc->lmi_annexA = hook;
221		NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
222		sc->protoID = 8;
223		SETLMITYPE(sc, SCF_ANNEX_A);
224		sc->protoname = NAME_ANNEXA;
225		nglmi_startup_fixed(sc, hook);
226	} else if (strcmp(name, NG_LMI_HOOK_ANNEXD) == 0) {
227		sc->lmi_annexD = hook;
228		NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
229		sc->protoID = 8;
230		SETLMITYPE(sc, SCF_ANNEX_D);
231		sc->protoname = NAME_ANNEXD;
232		nglmi_startup_fixed(sc, hook);
233	} else if (strcmp(name, NG_LMI_HOOK_GROUPOF4) == 0) {
234		sc->lmi_group4 = hook;
235		NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
236		sc->protoID = 9;
237		SETLMITYPE(sc, SCF_GROUP4);
238		sc->protoname = NAME_GROUP4;
239		nglmi_startup_fixed(sc, hook);
240	} else if (strcmp(name, NG_LMI_HOOK_AUTO0) == 0) {
241		/* Note this, and if B is already installed, we're complete */
242		sc->lmi_channel0 = hook;
243		sc->protoname = NAME_NONE;
244		NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
245		if (sc->lmi_channel1023)
246			nglmi_startup_auto(sc);
247	} else if (strcmp(name, NG_LMI_HOOK_AUTO1023) == 0) {
248		/* Note this, and if A is already installed, we're complete */
249		sc->lmi_channel1023 = hook;
250		sc->protoname = NAME_NONE;
251		NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
252		if (sc->lmi_channel0)
253			nglmi_startup_auto(sc);
254	} else
255		return (EINVAL);		/* unknown hook */
256	return (0);
257}
258
259/*
260 * We have just attached to a live (we hope) node.
261 * Fire out a LMI inquiry, and then start up the timers.
262 */
263static void
264LMI_ticker(node_p node, hook_p hook, void *arg1, int arg2)
265{
266	sc_p sc = NG_NODE_PRIVATE(node);
267
268	if (sc->flags & SCF_AUTO) {
269		ngauto_state_machine(sc);
270		ng_callout(&sc->handle, node, NULL, NG_LMI_POLL_RATE * hz,
271		    LMI_ticker, NULL, 0);
272	} else {
273		if (sc->livs++ >= sc->liv_per_full) {
274			nglmi_inquire(sc, 1);
275			/* sc->livs = 0; *//* do this when we get the answer! */
276		} else {
277			nglmi_inquire(sc, 0);
278		}
279		ng_callout(&sc->handle, node, NULL, sc->liv_rate * hz,
280		    LMI_ticker, NULL, 0);
281	}
282}
283
284static void
285nglmi_startup_fixed(sc_p sc, hook_p hook)
286{
287	sc->flags |= (SCF_FIXED | SCF_CONNECTED);
288	sc->lmi_channel = hook;
289	nglmi_startup(sc);
290}
291
292static void
293nglmi_startup_auto(sc_p sc)
294{
295	sc->flags |= (SCF_AUTO | SCF_CONNECTED);
296	sc->poll_state = 0;	/* reset state machine */
297	sc->poll_count = 0;
298	nglmi_startup(sc);
299}
300
301static void
302nglmi_startup(sc_p sc)
303{
304	sc->remote_seq = 0;
305	sc->local_seq = 1;
306	sc->seq_retries = 0;
307	sc->livs = sc->liv_per_full - 1;
308	/* start off the ticker in 1 sec */
309	ng_callout(&sc->handle, sc->node, NULL, hz, LMI_ticker, NULL, 0);
310}
311
312static void
313nglmi_inquire(sc_p sc, int full)
314{
315	struct mbuf *m;
316	struct ng_tag_prio *ptag;
317	char   *cptr, *start;
318	int     error;
319
320	if (sc->lmi_channel == NULL)
321		return;
322	MGETHDR(m, M_DONTWAIT, MT_DATA);
323	if (m == NULL) {
324		log(LOG_ERR, "nglmi: unable to start up LMI processing\n");
325		return;
326	}
327	m->m_pkthdr.rcvif = NULL;
328
329	/* Attach a tag to packet, marking it of link level state priority, so
330	 * that device driver would put it in the beginning of queue */
331
332	ptag = (struct ng_tag_prio *)m_tag_alloc(NGM_GENERIC_COOKIE, NG_TAG_PRIO,
333	    (sizeof(struct ng_tag_prio) - sizeof(struct m_tag)), M_NOWAIT);
334	if (ptag != NULL) {	/* if it failed, well, it was optional anyhow */
335		ptag->priority = NG_PRIO_LINKSTATE;
336		ptag->discardability = -1;
337		m_tag_prepend(m, &ptag->tag);
338	}
339
340	m->m_data += 4;		/* leave some room for a header */
341	cptr = start = mtod(m, char *);
342	/* add in the header for an LMI inquiry. */
343	*cptr++ = 0x03;		/* UI frame */
344	if (GROUP4(sc))
345		*cptr++ = 0x09;	/* proto discriminator */
346	else
347		*cptr++ = 0x08;	/* proto discriminator */
348	*cptr++ = 0x00;		/* call reference */
349	*cptr++ = 0x75;		/* inquiry */
350
351	/* If we are Annex-D, add locking shift to codeset 5. */
352	if (ANNEXD(sc))
353		*cptr++ = 0x95;	/* locking shift */
354	/* Add a request type */
355	if (ANNEXA(sc))
356		*cptr++ = 0x51;	/* report type */
357	else
358		*cptr++ = 0x01;	/* report type */
359	*cptr++ = 0x01;		/* size = 1 */
360	if (full)
361		*cptr++ = 0x00;	/* full */
362	else
363		*cptr++ = 0x01;	/* partial */
364
365	/* Add a link verification IE */
366	if (ANNEXA(sc))
367		*cptr++ = 0x53;	/* verification IE */
368	else
369		*cptr++ = 0x03;	/* verification IE */
370	*cptr++ = 0x02;		/* 2 extra bytes */
371	*cptr++ = sc->local_seq;
372	*cptr++ = sc->remote_seq;
373	sc->seq_retries++;
374
375	/* Send it */
376	m->m_len = m->m_pkthdr.len = cptr - start;
377	NG_SEND_DATA_ONLY(error, sc->lmi_channel, m);
378
379	/* If we've been sending requests for long enough, and there has
380	 * been no response, then mark as DOWN, any DLCIs that are UP. */
381	if (sc->seq_retries == LMI_PATIENCE) {
382		int     count;
383
384		for (count = 0; count < MAXDLCI; count++)
385			if (sc->dlci_state[count] == DLCI_UP)
386				sc->dlci_state[count] = DLCI_DOWN;
387	}
388}
389
390/*
391 * State machine for LMI auto-detect. The transitions are ordered
392 * to try the more likely possibilities first.
393 */
394static void
395ngauto_state_machine(sc_p sc)
396{
397	if ((sc->poll_count <= 0) || (sc->poll_count > LMIPOLLSIZE)) {
398		/* time to change states in the auto probe machine */
399		/* capture wild values of poll_count while we are at it */
400		sc->poll_count = LMIPOLLSIZE;
401		sc->poll_state++;
402	}
403	switch (sc->poll_state) {
404	case 7:
405		log(LOG_WARNING, "nglmi: no response from exchange\n");
406	default:		/* capture bad states */
407		sc->poll_state = 1;
408	case 1:
409		sc->lmi_channel = sc->lmi_channel0;
410		SETLMITYPE(sc, SCF_ANNEX_D);
411		break;
412	case 2:
413		sc->lmi_channel = sc->lmi_channel1023;
414		SETLMITYPE(sc, SCF_ANNEX_D);
415		break;
416	case 3:
417		sc->lmi_channel = sc->lmi_channel0;
418		SETLMITYPE(sc, SCF_ANNEX_A);
419		break;
420	case 4:
421		sc->lmi_channel = sc->lmi_channel1023;
422		SETLMITYPE(sc, SCF_GROUP4);
423		break;
424	case 5:
425		sc->lmi_channel = sc->lmi_channel1023;
426		SETLMITYPE(sc, SCF_ANNEX_A);
427		break;
428	case 6:
429		sc->lmi_channel = sc->lmi_channel0;
430		SETLMITYPE(sc, SCF_GROUP4);
431		break;
432	}
433
434	/* send an inquirey encoded appropriatly */
435	nglmi_inquire(sc, 0);
436	sc->poll_count--;
437}
438
439/*
440 * Receive a netgraph control message.
441 */
442static int
443nglmi_rcvmsg(node_p node, item_p item, hook_p lasthook)
444{
445	sc_p    sc = NG_NODE_PRIVATE(node);
446	struct ng_mesg *resp = NULL;
447	int     error = 0;
448	struct ng_mesg *msg;
449
450	NGI_GET_MSG(item, msg);
451	switch (msg->header.typecookie) {
452	case NGM_GENERIC_COOKIE:
453		switch (msg->header.cmd) {
454		case NGM_TEXT_STATUS:
455		    {
456			char   *arg;
457			int     pos, count;
458
459			NG_MKRESPONSE(resp, msg, NG_TEXTRESPONSE, M_NOWAIT);
460			if (resp == NULL) {
461				error = ENOMEM;
462				break;
463			}
464			arg = resp->data;
465			pos = sprintf(arg, "protocol %s ", sc->protoname);
466			if (sc->flags & SCF_FIXED)
467				pos += sprintf(arg + pos, "fixed\n");
468			else if (sc->flags & SCF_AUTO)
469				pos += sprintf(arg + pos, "auto-detecting\n");
470			else
471				pos += sprintf(arg + pos, "auto on dlci %d\n",
472				    (sc->lmi_channel == sc->lmi_channel0) ?
473				    0 : 1023);
474			pos += sprintf(arg + pos,
475			    "keepalive period: %d seconds\n", sc->liv_rate);
476			pos += sprintf(arg + pos,
477			    "unacknowledged keepalives: %ld\n",
478			    sc->seq_retries);
479			for (count = 0;
480			     ((count <= MAXDLCI)
481			      && (pos < (NG_TEXTRESPONSE - 20)));
482			     count++) {
483				if (sc->dlci_state[count]) {
484					pos += sprintf(arg + pos,
485					       "dlci %d %s\n", count,
486					       (sc->dlci_state[count]
487					== DLCI_UP) ? "up" : "down");
488				}
489			}
490			resp->header.arglen = pos + 1;
491			break;
492		    }
493		default:
494			error = EINVAL;
495			break;
496		}
497		break;
498	case NGM_LMI_COOKIE:
499		switch (msg->header.cmd) {
500		case NGM_LMI_GET_STATUS:
501		    {
502			struct nglmistat *stat;
503			int k;
504
505			NG_MKRESPONSE(resp, msg, sizeof(*stat), M_NOWAIT);
506			if (!resp) {
507				error = ENOMEM;
508				break;
509			}
510			stat = (struct nglmistat *) resp->data;
511			strncpy(stat->proto,
512			     sc->protoname, sizeof(stat->proto) - 1);
513			strncpy(stat->hook,
514			      sc->protoname, sizeof(stat->hook) - 1);
515			stat->autod = !!(sc->flags & SCF_AUTO);
516			stat->fixed = !!(sc->flags & SCF_FIXED);
517			for (k = 0; k <= MAXDLCI; k++) {
518				switch (sc->dlci_state[k]) {
519				case DLCI_UP:
520					stat->up[k / 8] |= (1 << (k % 8));
521					/* fall through */
522				case DLCI_DOWN:
523					stat->seen[k / 8] |= (1 << (k % 8));
524					break;
525				}
526			}
527			break;
528		    }
529		default:
530			error = EINVAL;
531			break;
532		}
533		break;
534	default:
535		error = EINVAL;
536		break;
537	}
538
539	NG_RESPOND_MSG(error, node, item, resp);
540	NG_FREE_MSG(msg);
541	return (error);
542}
543
544#define STEPBY(stepsize)			\
545	do {					\
546		packetlen -= (stepsize);	\
547		data += (stepsize);		\
548	} while (0)
549
550/*
551 * receive data, and use it to update our status.
552 * Anything coming in on the debug port is discarded.
553 */
554static int
555nglmi_rcvdata(hook_p hook, item_p item)
556{
557	sc_p    sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
558	const	u_char *data;
559	unsigned short dlci;
560	u_short packetlen;
561	int     resptype_seen = 0;
562	struct mbuf *m;
563
564	NGI_GET_M(item, m);
565	NG_FREE_ITEM(item);
566	if (NG_HOOK_PRIVATE(hook) == NULL) {
567		goto drop;
568	}
569	packetlen = m->m_len;
570
571	/* XXX what if it's more than 1 mbuf? */
572	if ((packetlen > MHLEN) && !(m->m_flags & M_EXT)) {
573		log(LOG_WARNING, "nglmi: packetlen (%d) too big\n", packetlen);
574		goto drop;
575	}
576	if (m->m_len < packetlen && (m = m_pullup(m, packetlen)) == NULL) {
577		log(LOG_WARNING,
578		    "nglmi: m_pullup failed for %d bytes\n", packetlen);
579		return (0);
580	}
581	if (nglmi_checkdata(hook, m) == 0)
582		return (0);
583
584	/* pass the first 4 bytes (already checked in the nglmi_checkdata()) */
585	data = mtod(m, const u_char *);
586	STEPBY(4);
587
588	/* Now check if there is a 'locking shift'. This is only seen in
589	 * Annex D frames. don't bother checking, we already did that. Don't
590	 * increment immediatly as it might not be there. */
591	if (ANNEXD(sc))
592		STEPBY(1);
593
594	/* If we get this far we should consider that it is a legitimate
595	 * frame and we know what it is. */
596	if (sc->flags & SCF_AUTO) {
597		/* note the hook that this valid channel came from and drop
598		 * out of auto probe mode. */
599		if (ANNEXA(sc))
600			sc->protoname = NAME_ANNEXA;
601		else if (ANNEXD(sc))
602			sc->protoname = NAME_ANNEXD;
603		else if (GROUP4(sc))
604			sc->protoname = NAME_GROUP4;
605		else {
606			log(LOG_ERR, "nglmi: No known type\n");
607			goto drop;
608		}
609		sc->lmi_channel = hook;
610		sc->flags &= ~SCF_AUTO;
611		log(LOG_INFO, "nglmi: auto-detected %s LMI on DLCI %d\n",
612		    sc->protoname, hook == sc->lmi_channel0 ? 0 : 1023);
613	}
614
615	/* While there is more data in the status packet, keep processing
616	 * status items. First make sure there is enough data for the
617	 * segment descriptor's length field. */
618	while (packetlen >= 2) {
619		u_int   segtype = data[0];
620		u_int   segsize = data[1];
621
622		/* Now that we know how long it claims to be, make sure
623		 * there is enough data for the next seg. */
624		if (packetlen < segsize + 2)
625			break;
626		switch (segtype) {
627		case 0x01:
628		case 0x51:
629			if (resptype_seen) {
630				log(LOG_WARNING, "nglmi: dup MSGTYPE\n");
631				goto nextIE;
632			}
633			resptype_seen++;
634			/* The remote end tells us what kind of response
635			 * this is. Only expect a type 0 or 1. if we are a
636			 * full status, invalidate a few DLCIs just to see
637			 * that they are still ok. */
638			if (segsize != 1)
639				goto nextIE;
640			switch (data[2]) {
641			case 1:
642				/* partial status, do no extra processing */
643				break;
644			case 0:
645			    {
646				int     count = 0;
647				int     idx = sc->invalidx;
648
649				for (count = 0; count < 10; count++) {
650					if (idx > MAXDLCI)
651						idx = 0;
652					if (sc->dlci_state[idx] == DLCI_UP)
653						sc->dlci_state[idx] = DLCI_DOWN;
654					idx++;
655				}
656				sc->invalidx = idx;
657				/* we got and we wanted one. relax
658				 * now.. but don't reset to 0 if it
659				 * was unrequested. */
660				if (sc->livs > sc->liv_per_full)
661					sc->livs = 0;
662				break;
663			    }
664			}
665			break;
666		case 0x03:
667		case 0x53:
668			/* The remote tells us what it thinks the sequence
669			 * numbers are. If it's not size 2, it must be a
670			 * duplicate to have gotten this far, skip it. */
671			if (segsize != 2)
672				goto nextIE;
673			sc->remote_seq = data[2];
674			if (sc->local_seq == data[3]) {
675				sc->local_seq++;
676				sc->seq_retries = 0;
677				/* Note that all 3 Frame protocols seem to
678				 * not like 0 as a sequence number. */
679				if (sc->local_seq == 0)
680					sc->local_seq = 1;
681			}
682			break;
683		case 0x07:
684		case 0x57:
685			/* The remote tells us about a DLCI that it knows
686			 * about. There may be many of these in a single
687			 * status response */
688			switch (segsize) {
689			case 6:/* only on 'group of 4' */
690				dlci = ((u_short) data[2] & 0xff) << 8;
691				dlci |= (data[3] & 0xff);
692				if ((dlci < 1024) && (dlci > 0)) {
693				  /* XXX */
694				}
695				break;
696			case 3:
697				dlci = ((u_short) data[2] & 0x3f) << 4;
698				dlci |= ((data[3] & 0x78) >> 3);
699				if ((dlci < 1024) && (dlci > 0)) {
700					/* set up the bottom half of the
701					 * support for that dlci if it's not
702					 * already been done */
703					/* store this information somewhere */
704				}
705				break;
706			default:
707				goto nextIE;
708			}
709			if (sc->dlci_state[dlci] != DLCI_UP) {
710				/* bring new DLCI to life */
711				/* may do more here some day */
712				if (sc->dlci_state[dlci] != DLCI_DOWN)
713					log(LOG_INFO,
714					    "nglmi: DLCI %d became active\n",
715					    dlci);
716				sc->dlci_state[dlci] = DLCI_UP;
717			}
718			break;
719		}
720nextIE:
721		STEPBY(segsize + 2);
722	}
723	NG_FREE_M(m);
724	return (0);
725
726drop:
727	NG_FREE_M(m);
728	return (EINVAL);
729}
730
731/*
732 * Check that a packet is entirely kosha.
733 * return 1 of ok, and 0 if not.
734 * All data is discarded if a 0 is returned.
735 */
736static int
737nglmi_checkdata(hook_p hook, struct mbuf *m)
738{
739	sc_p    sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
740	const	u_char *data;
741	u_short packetlen;
742	unsigned short dlci;
743	u_char  type;
744	u_char  nextbyte;
745	int     seq_seen = 0;
746	int     resptype_seen = 0;	/* 0 , 1 (partial) or 2 (full) */
747	int     highest_dlci = 0;
748
749	packetlen = m->m_len;
750	data = mtod(m, const u_char *);
751	if (*data != 0x03) {
752		log(LOG_WARNING, "nglmi: unexpected value in LMI(%d)\n", 1);
753		goto reject;
754	}
755	STEPBY(1);
756
757	/* look at the protocol ID */
758	nextbyte = *data;
759	if (sc->flags & SCF_AUTO) {
760		SETLMITYPE(sc, SCF_NOLMI);	/* start with a clean slate */
761		switch (nextbyte) {
762		case 0x8:
763			sc->protoID = 8;
764			break;
765		case 0x9:
766			SETLMITYPE(sc, SCF_GROUP4);
767			sc->protoID = 9;
768			break;
769		default:
770			log(LOG_WARNING, "nglmi: bad Protocol ID(%d)\n",
771			    (int) nextbyte);
772			goto reject;
773		}
774	} else {
775		if (nextbyte != sc->protoID) {
776			log(LOG_WARNING, "nglmi: unexpected Protocol ID(%d)\n",
777			    (int) nextbyte);
778			goto reject;
779		}
780	}
781	STEPBY(1);
782
783	/* check call reference (always null in non ISDN frame relay) */
784	if (*data != 0x00) {
785		log(LOG_WARNING, "nglmi: unexpected Call Reference (0x%x)\n",
786		    data[-1]);
787		goto reject;
788	}
789	STEPBY(1);
790
791	/* check message type */
792	switch ((type = *data)) {
793	case 0x75:		/* Status enquiry */
794		log(LOG_WARNING, "nglmi: unexpected message type(0x%x)\n",
795		    data[-1]);
796		goto reject;
797	case 0x7D:		/* Status message */
798		break;
799	default:
800		log(LOG_WARNING,
801		    "nglmi: unexpected msg type(0x%x) \n", (int) type);
802		goto reject;
803	}
804	STEPBY(1);
805
806	/* Now check if there is a 'locking shift'. This is only seen in
807	 * Annex D frames. Don't increment immediately as it might not be
808	 * there. */
809	nextbyte = *data;
810	if (sc->flags & SCF_AUTO) {
811		if (!(GROUP4(sc))) {
812			if (nextbyte == 0x95) {
813				SETLMITYPE(sc, SCF_ANNEX_D);
814				STEPBY(1);
815			} else
816				SETLMITYPE(sc, SCF_ANNEX_A);
817		} else if (nextbyte == 0x95) {
818			log(LOG_WARNING, "nglmi: locking shift seen in G4\n");
819			goto reject;
820		}
821	} else {
822		if (ANNEXD(sc)) {
823			if (*data == 0x95)
824				STEPBY(1);
825			else {
826				log(LOG_WARNING,
827				    "nglmi: locking shift missing\n");
828				goto reject;
829			}
830		} else if (*data == 0x95) {
831			log(LOG_WARNING, "nglmi: locking shift seen\n");
832			goto reject;
833		}
834	}
835
836	/* While there is more data in the status packet, keep processing
837	 * status items. First make sure there is enough data for the
838	 * segment descriptor's length field. */
839	while (packetlen >= 2) {
840		u_int   segtype = data[0];
841		u_int   segsize = data[1];
842
843		/* Now that we know how long it claims to be, make sure
844		 * there is enough data for the next seg. */
845		if (packetlen < (segsize + 2)) {
846			log(LOG_WARNING, "nglmi: IE longer than packet\n");
847			break;
848		}
849		switch (segtype) {
850		case 0x01:
851		case 0x51:
852			/* According to MCI's HP analyser, we should just
853			 * ignore if there is mor ethan one of these (?). */
854			if (resptype_seen) {
855				log(LOG_WARNING, "nglmi: dup MSGTYPE\n");
856				goto nextIE;
857			}
858			if (segsize != 1) {
859				log(LOG_WARNING, "nglmi: MSGTYPE wrong size\n");
860				goto reject;
861			}
862			/* The remote end tells us what kind of response
863			 * this is. Only expect a type 0 or 1. if it was a
864			 * full (type 0) check we just asked for a type
865			 * full. */
866			switch (data[2]) {
867			case 1:/* partial */
868				if (sc->livs > sc->liv_per_full) {
869					log(LOG_WARNING,
870					  "nglmi: LIV when FULL expected\n");
871					goto reject;	/* need full */
872				}
873				resptype_seen = 1;
874				break;
875			case 0:/* full */
876				/* Full response is always acceptable */
877				resptype_seen = 2;
878				break;
879			default:
880				log(LOG_WARNING,
881				 "nglmi: Unknown report type %d\n", data[2]);
882				goto reject;
883			}
884			break;
885		case 0x03:
886		case 0x53:
887			/* The remote tells us what it thinks the sequence
888			 * numbers are. I would have thought that there
889			 * needs to be one and only one of these, but MCI
890			 * want us to just ignore extras. (?) */
891			if (resptype_seen == 0) {
892				log(LOG_WARNING, "nglmi: no TYPE before SEQ\n");
893				goto reject;
894			}
895			if (seq_seen != 0)	/* already seen seq numbers */
896				goto nextIE;
897			if (segsize != 2) {
898				log(LOG_WARNING, "nglmi: bad SEQ sts size\n");
899				goto reject;
900			}
901			if (sc->local_seq != data[3]) {
902				log(LOG_WARNING, "nglmi: unexpected SEQ\n");
903				goto reject;
904			}
905			seq_seen = 1;
906			break;
907		case 0x07:
908		case 0x57:
909			/* The remote tells us about a DLCI that it knows
910			 * about. There may be many of these in a single
911			 * status response */
912			if (seq_seen != 1) {	/* already seen seq numbers? */
913				log(LOG_WARNING,
914				    "nglmi: No sequence before DLCI\n");
915				goto reject;
916			}
917			if (resptype_seen != 2) {	/* must be full */
918				log(LOG_WARNING,
919				    "nglmi: No resp type before DLCI\n");
920				goto reject;
921			}
922			if (GROUP4(sc)) {
923				if (segsize != 6) {
924					log(LOG_WARNING,
925					    "nglmi: wrong IE segsize\n");
926					goto reject;
927				}
928				dlci = ((u_short) data[2] & 0xff) << 8;
929				dlci |= (data[3] & 0xff);
930			} else {
931				if (segsize != 3) {
932					log(LOG_WARNING,
933					    "nglmi: DLCI headersize of %d"
934					    " not supported\n", segsize - 1);
935					goto reject;
936				}
937				dlci = ((u_short) data[2] & 0x3f) << 4;
938				dlci |= ((data[3] & 0x78) >> 3);
939			}
940			/* async can only have one of these */
941#if 0				/* async not yet accepted */
942			if (async && highest_dlci) {
943				log(LOG_WARNING,
944				    "nglmi: Async with > 1 DLCI\n");
945				goto reject;
946			}
947#endif
948			/* Annex D says these will always be Ascending, but
949			 * the HP test for G4 says we should accept
950			 * duplicates, so for now allow that. ( <= vs. < ) */
951#if 0
952			/* MCI tests want us to accept out of order for AnxD */
953			if ((!GROUP4(sc)) && (dlci < highest_dlci)) {
954				/* duplicate or mis-ordered dlci */
955				/* (spec says they will increase in number) */
956				log(LOG_WARNING, "nglmi: DLCI out of order\n");
957				goto reject;
958			}
959#endif
960			if (dlci > 1023) {
961				log(LOG_WARNING, "nglmi: DLCI out of range\n");
962				goto reject;
963			}
964			highest_dlci = dlci;
965			break;
966		default:
967			log(LOG_WARNING,
968			    "nglmi: unknown LMI segment type %d\n", segtype);
969		}
970nextIE:
971		STEPBY(segsize + 2);
972	}
973	if (packetlen != 0) {	/* partial junk at end? */
974		log(LOG_WARNING,
975		    "nglmi: %d bytes extra at end of packet\n", packetlen);
976		goto print;
977	}
978	if (resptype_seen == 0) {
979		log(LOG_WARNING, "nglmi: No response type seen\n");
980		goto reject;	/* had no response type */
981	}
982	if (seq_seen == 0) {
983		log(LOG_WARNING, "nglmi: No sequence numbers seen\n");
984		goto reject;	/* had no sequence numbers */
985	}
986	return (1);
987
988print:
989	{
990		int     i, j, k, pos;
991		char    buf[100];
992		int     loc;
993		const	u_char *bp = mtod(m, const u_char *);
994
995		k = i = 0;
996		loc = (m->m_len - packetlen);
997		log(LOG_WARNING, "nglmi: error at location %d\n", loc);
998		while (k < m->m_len) {
999			pos = 0;
1000			j = 0;
1001			while ((j++ < 16) && k < m->m_len) {
1002				pos += sprintf(buf + pos, "%c%02x",
1003					       ((loc == k) ? '>' : ' '),
1004					       bp[k]);
1005				k++;
1006			}
1007			if (i == 0)
1008				log(LOG_WARNING, "nglmi: packet data:%s\n", buf);
1009			else
1010				log(LOG_WARNING, "%04d              :%s\n", k, buf);
1011			i++;
1012		}
1013	}
1014	return (1);
1015reject:
1016	{
1017		int     i, j, k, pos;
1018		char    buf[100];
1019		int     loc;
1020		const	u_char *bp = mtod(m, const u_char *);
1021
1022		k = i = 0;
1023		loc = (m->m_len - packetlen);
1024		log(LOG_WARNING, "nglmi: error at location %d\n", loc);
1025		while (k < m->m_len) {
1026			pos = 0;
1027			j = 0;
1028			while ((j++ < 16) && k < m->m_len) {
1029				pos += sprintf(buf + pos, "%c%02x",
1030					       ((loc == k) ? '>' : ' '),
1031					       bp[k]);
1032				k++;
1033			}
1034			if (i == 0)
1035				log(LOG_WARNING, "nglmi: packet data:%s\n", buf);
1036			else
1037				log(LOG_WARNING, "%04d              :%s\n", k, buf);
1038			i++;
1039		}
1040	}
1041	NG_FREE_M(m);
1042	return (0);
1043}
1044
1045/*
1046 * Do local shutdown processing..
1047 * Cut any remaining links and free our local resources.
1048 */
1049static int
1050nglmi_shutdown(node_p node)
1051{
1052	const sc_p sc = NG_NODE_PRIVATE(node);
1053
1054	NG_NODE_SET_PRIVATE(node, NULL);
1055	NG_NODE_UNREF(sc->node);
1056	free(sc, M_NETGRAPH);
1057	return (0);
1058}
1059
1060/*
1061 * Hook disconnection
1062 * For this type, removal of any link except "debug" destroys the node.
1063 */
1064static int
1065nglmi_disconnect(hook_p hook)
1066{
1067	const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
1068
1069	/* OK to remove debug hook(s) */
1070	if (NG_HOOK_PRIVATE(hook) == NULL)
1071		return (0);
1072
1073	/* Stop timer if it's currently active */
1074	if (sc->flags & SCF_CONNECTED)
1075		ng_uncallout(&sc->handle, sc->node);
1076
1077	/* Self-destruct */
1078	if (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
1079		ng_rmnode_self(NG_HOOK_NODE(hook));
1080	return (0);
1081}
1082
1083