xref: /freebsd/sys/netgraph/ng_pppoe.c (revision 35a04710d7286aa9538917fd7f8e417dbee95b82)
1 /*
2  * ng_pppoe.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  * $FreeBSD$
41  * $Whistle: ng_pppoe.c,v 1.10 1999/11/01 09:24:52 julian Exp $
42  */
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/ktr.h>
48 #include <sys/mbuf.h>
49 #include <sys/malloc.h>
50 #include <sys/errno.h>
51 #include <sys/syslog.h>
52 #include <net/ethernet.h>
53 
54 #include <netgraph/ng_message.h>
55 #include <netgraph/netgraph.h>
56 #include <netgraph/ng_parse.h>
57 #include <netgraph/ng_pppoe.h>
58 #include <netgraph/ng_ether.h>
59 
60 #ifdef NG_SEPARATE_MALLOC
61 MALLOC_DEFINE(M_NETGRAPH_PPPOE, "netgraph_pppoe", "netgraph pppoe node");
62 #else
63 #define M_NETGRAPH_PPPOE M_NETGRAPH
64 #endif
65 
66 #define SIGNOFF "session closed"
67 #define OFFSETOF(s, e) ((char *)&((s *)0)->e - (char *)((s *)0))
68 
69 /*
70  * This section contains the netgraph method declarations for the
71  * pppoe node. These methods define the netgraph pppoe 'type'.
72  */
73 
74 static ng_constructor_t	ng_pppoe_constructor;
75 static ng_rcvmsg_t	ng_pppoe_rcvmsg;
76 static ng_shutdown_t	ng_pppoe_shutdown;
77 static ng_newhook_t	ng_pppoe_newhook;
78 static ng_connect_t	ng_pppoe_connect;
79 static ng_rcvdata_t	ng_pppoe_rcvdata;
80 static ng_rcvdata_t	ng_pppoe_rcvdata_ether;
81 static ng_rcvdata_t	ng_pppoe_rcvdata_debug;
82 static ng_disconnect_t	ng_pppoe_disconnect;
83 
84 /* Parse type for struct ngpppoe_init_data */
85 static const struct ng_parse_struct_field ngpppoe_init_data_type_fields[]
86 	= NG_PPPOE_INIT_DATA_TYPE_INFO;
87 static const struct ng_parse_type ngpppoe_init_data_state_type = {
88 	&ng_parse_struct_type,
89 	&ngpppoe_init_data_type_fields
90 };
91 
92 /* Parse type for struct ngpppoe_sts */
93 static const struct ng_parse_struct_field ng_pppoe_sts_type_fields[]
94 	= NG_PPPOE_STS_TYPE_INFO;
95 static const struct ng_parse_type ng_pppoe_sts_state_type = {
96 	&ng_parse_struct_type,
97 	&ng_pppoe_sts_type_fields
98 };
99 
100 /* List of commands and how to convert arguments to/from ASCII */
101 static const struct ng_cmdlist ng_pppoe_cmds[] = {
102 	{
103 	  NGM_PPPOE_COOKIE,
104 	  NGM_PPPOE_CONNECT,
105 	  "pppoe_connect",
106 	  &ngpppoe_init_data_state_type,
107 	  NULL
108 	},
109 	{
110 	  NGM_PPPOE_COOKIE,
111 	  NGM_PPPOE_LISTEN,
112 	  "pppoe_listen",
113 	  &ngpppoe_init_data_state_type,
114 	  NULL
115 	},
116 	{
117 	  NGM_PPPOE_COOKIE,
118 	  NGM_PPPOE_OFFER,
119 	  "pppoe_offer",
120 	  &ngpppoe_init_data_state_type,
121 	  NULL
122 	},
123 	{
124 	  NGM_PPPOE_COOKIE,
125 	  NGM_PPPOE_SERVICE,
126 	  "pppoe_service",
127 	  &ngpppoe_init_data_state_type,
128 	  NULL
129 	},
130 	{
131 	  NGM_PPPOE_COOKIE,
132 	  NGM_PPPOE_SUCCESS,
133 	  "pppoe_success",
134 	  &ng_pppoe_sts_state_type,
135 	  NULL
136 	},
137 	{
138 	  NGM_PPPOE_COOKIE,
139 	  NGM_PPPOE_FAIL,
140 	  "pppoe_fail",
141 	  &ng_pppoe_sts_state_type,
142 	  NULL
143 	},
144 	{
145 	  NGM_PPPOE_COOKIE,
146 	  NGM_PPPOE_CLOSE,
147 	  "pppoe_close",
148 	  &ng_pppoe_sts_state_type,
149 	  NULL
150 	},
151 	{
152 	  NGM_PPPOE_COOKIE,
153 	  NGM_PPPOE_SETMODE,
154 	  "pppoe_setmode",
155 	  &ng_parse_string_type,
156 	  NULL
157 	},
158 	{
159 	  NGM_PPPOE_COOKIE,
160 	  NGM_PPPOE_GETMODE,
161 	  "pppoe_getmode",
162 	  NULL,
163 	  &ng_parse_string_type
164 	},
165 	{
166 	  NGM_PPPOE_COOKIE,
167 	  NGM_PPPOE_SETENADDR,
168 	  "setenaddr",
169 	  &ng_parse_enaddr_type,
170 	  NULL
171 	},
172 	{ 0 }
173 };
174 
175 /* Netgraph node type descriptor */
176 static struct ng_type typestruct = {
177 	.version =	NG_ABI_VERSION,
178 	.name =		NG_PPPOE_NODE_TYPE,
179 	.constructor =	ng_pppoe_constructor,
180 	.rcvmsg =	ng_pppoe_rcvmsg,
181 	.shutdown =	ng_pppoe_shutdown,
182 	.newhook =	ng_pppoe_newhook,
183 	.connect =	ng_pppoe_connect,
184 	.rcvdata =	ng_pppoe_rcvdata,
185 	.disconnect =	ng_pppoe_disconnect,
186 	.cmdlist =	ng_pppoe_cmds,
187 };
188 NETGRAPH_INIT(pppoe, &typestruct);
189 
190 /*
191  * States for the session state machine.
192  * These have no meaning if there is no hook attached yet.
193  */
194 enum state {
195     PPPOE_SNONE=0,	/* [both] Initial state */
196     PPPOE_LISTENING,	/* [Daemon] Listening for discover initiation pkt */
197     PPPOE_SINIT,	/* [Client] Sent discovery initiation */
198     PPPOE_PRIMED,	/* [Server] Awaiting PADI from daemon */
199     PPPOE_SOFFER,	/* [Server] Sent offer message  (got PADI)*/
200     PPPOE_SREQ,		/* [Client] Sent a Request */
201     PPPOE_NEWCONNECTED,	/* [Server] Connection established, No data received */
202     PPPOE_CONNECTED,	/* [Both] Connection established, Data received */
203     PPPOE_DEAD		/* [Both] */
204 };
205 
206 #define NUMTAGS 20 /* number of tags we are set up to work with */
207 
208 /*
209  * Information we store for each hook on each node for negotiating the
210  * session. The mbuf and cluster are freed once negotiation has completed.
211  * The whole negotiation block is then discarded.
212  */
213 
214 struct sess_neg {
215 	struct mbuf 		*m; /* holds cluster with last sent packet */
216 	union	packet		*pkt; /* points within the above cluster */
217 	struct callout		handle;   /* see timeout(9) */
218 	u_int			timeout; /* 0,1,2,4,8,16 etc. seconds */
219 	u_int			numtags;
220 	const struct pppoe_tag	*tags[NUMTAGS];
221 	u_int			service_len;
222 	u_int			ac_name_len;
223 
224 	struct datatag		service;
225 	struct datatag		ac_name;
226 };
227 typedef struct sess_neg *negp;
228 
229 /*
230  * Session information that is needed after connection.
231  */
232 struct sess_con {
233 	hook_p  		hook;
234 	uint16_t		Session_ID;
235 	enum state		state;
236 	ng_ID_t			creator;	/* who to notify */
237 	struct pppoe_full_hdr	pkt_hdr;	/* used when connected */
238 	negp			neg;		/* used when negotiating */
239 };
240 typedef struct sess_con *sessp;
241 
242 /*
243  * Information we store for each node
244  */
245 struct PPPoE {
246 	node_p		node;		/* back pointer to node */
247 	hook_p  	ethernet_hook;
248 	hook_p  	debug_hook;
249 	u_int   	packets_in;	/* packets in from ethernet */
250 	u_int   	packets_out;	/* packets out towards ethernet */
251 	uint32_t	flags;
252 #define	COMPAT_3COM	0x00000001
253 #define	COMPAT_DLINK	0x00000002
254 	struct ether_header	eh;
255 };
256 typedef struct PPPoE *priv_p;
257 
258 union uniq {
259 	char bytes[sizeof(void *)];
260 	void *pointer;
261 };
262 
263 #define	LEAVE(x) do { error = x; goto quit; } while(0)
264 static void	pppoe_start(sessp sp);
265 static void	pppoe_ticker(node_p node, hook_p hook, void *arg1, int arg2);
266 static const	struct pppoe_tag *scan_tags(sessp sp,
267 			const struct pppoe_hdr* ph);
268 static	int	pppoe_send_event(sessp sp, enum cmd cmdid);
269 
270 /*************************************************************************
271  * Some basic utilities  from the Linux version with author's permission.*
272  * Author:	Michal Ostrowski <mostrows@styx.uwaterloo.ca>		 *
273  ************************************************************************/
274 
275 /*
276  * Generate a new session id
277  * XXX find out the FreeBSD locking scheme.
278  */
279 static uint16_t
280 get_new_sid(node_p node)
281 {
282 	static int pppoe_sid = 10;
283 	hook_p	hook;
284 	uint16_t val;
285 
286 restart:
287 	val = pppoe_sid++;
288 	/*
289 	 * Spec says 0xFFFF is reserved.
290 	 * Also don't use 0x0000
291 	 */
292 	if (val == 0xffff) {
293 		pppoe_sid = 20;
294 		goto restart;
295 	}
296 
297 	/* Check it isn't already in use. */
298 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
299 		sessp sp = NG_HOOK_PRIVATE(hook);
300 
301 		/* Skip any nonsession hook. */
302 		if (sp == NULL)
303 			continue;
304 		if (sp->Session_ID == val)
305 			goto restart;
306 	}
307 
308 	CTR2(KTR_NET, "%20s: new sid %d", __func__, val);
309 
310 	return (val);
311 }
312 
313 
314 /*
315  * Return the location where the next tag can be put
316  */
317 static __inline const struct pppoe_tag*
318 next_tag(const struct pppoe_hdr* ph)
319 {
320 	return (const struct pppoe_tag*)(((const char*)&ph->tag[0])
321 	    + ntohs(ph->length));
322 }
323 
324 /*
325  * Look for a tag of a specific type.
326  * Don't trust any length the other end says,
327  * but assume we already sanity checked ph->length.
328  */
329 static const struct pppoe_tag*
330 get_tag(const struct pppoe_hdr* ph, uint16_t idx)
331 {
332 	const char *const end = (const char *)next_tag(ph);
333 	const struct pppoe_tag *pt = &ph->tag[0];
334 	const char *ptn;
335 
336 	/*
337 	 * Keep processing tags while a tag header will still fit.
338 	 */
339 	while((const char*)(pt + 1) <= end) {
340 		/*
341 		 * If the tag data would go past the end of the packet, abort.
342 		 */
343 		ptn = (((const char *)(pt + 1)) + ntohs(pt->tag_len));
344 		if (ptn > end) {
345 			CTR2(KTR_NET, "%20s: invalid length for tag %d",
346 			    __func__, idx);
347 			return (NULL);
348 		}
349 		if (pt->tag_type == idx) {
350 			CTR2(KTR_NET, "%20s: found tag %d", __func__, idx);
351 			return (pt);
352 		}
353 
354 		pt = (const struct pppoe_tag*)ptn;
355 	}
356 
357 	CTR2(KTR_NET, "%20s: not found tag %d", __func__, idx);
358 	return (NULL);
359 }
360 
361 /**************************************************************************
362  * Inlines to initialise or add tags to a session's tag list.
363  **************************************************************************/
364 /*
365  * Initialise the session's tag list.
366  */
367 static void
368 init_tags(sessp sp)
369 {
370 	KASSERT(sp->neg != NULL, ("%s: no neg", __func__));
371 	sp->neg->numtags = 0;
372 }
373 
374 static void
375 insert_tag(sessp sp, const struct pppoe_tag *tp)
376 {
377 	negp neg = sp->neg;
378 	int i;
379 
380 	KASSERT(neg != NULL, ("%s: no neg", __func__));
381 	if ((i = neg->numtags++) < NUMTAGS) {
382 		neg->tags[i] = tp;
383 	} else {
384 		log(LOG_NOTICE, "ng_pppoe: asked to add too many tags to "
385 		    "packet\n");
386 		neg->numtags--;
387 	}
388 }
389 
390 /*
391  * Make up a packet, using the tags filled out for the session.
392  *
393  * Assume that the actual pppoe header and ethernet header
394  * are filled out externally to this routine.
395  * Also assume that neg->wh points to the correct
396  * location at the front of the buffer space.
397  */
398 static void
399 make_packet(sessp sp) {
400 	struct pppoe_full_hdr *wh = &sp->neg->pkt->pkt_header;
401 	const struct pppoe_tag **tag;
402 	char *dp;
403 	int count;
404 	int tlen;
405 	uint16_t length = 0;
406 
407 	KASSERT((sp->neg != NULL) && (sp->neg->m != NULL),
408 	    ("%s: called from wrong state", __func__));
409 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
410 
411 	dp = (char *)wh->ph.tag;
412 	for (count = 0, tag = sp->neg->tags;
413 	    ((count < sp->neg->numtags) && (count < NUMTAGS));
414 	    tag++, count++) {
415 		tlen = ntohs((*tag)->tag_len) + sizeof(**tag);
416 		if ((length + tlen) > (ETHER_MAX_LEN - 4 - sizeof(*wh))) {
417 			log(LOG_NOTICE, "ng_pppoe: tags too long\n");
418 			sp->neg->numtags = count;
419 			break;	/* XXX chop off what's too long */
420 		}
421 		bcopy(*tag, (char *)dp, tlen);
422 		length += tlen;
423 		dp += tlen;
424 	}
425  	wh->ph.length = htons(length);
426 	sp->neg->m->m_len = length + sizeof(*wh);
427 	sp->neg->m->m_pkthdr.len = length + sizeof(*wh);
428 }
429 
430 /**************************************************************************
431  * Routines to match a service.						  *
432  **************************************************************************/
433 
434 /*
435  * Find a hook that has a service string that matches that
436  * we are seeking. For now use a simple string.
437  * In the future we may need something like regexp().
438  *
439  * Null string is a wildcard (ANY service), according to RFC2516.
440  * And historical FreeBSD wildcard is also "*".
441  */
442 
443 static hook_p
444 pppoe_match_svc(node_p node, const struct pppoe_tag *tag)
445 {
446 	hook_p hook;
447 
448 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
449 		sessp sp = NG_HOOK_PRIVATE(hook);
450 		negp neg;
451 
452 		/* Skip any nonsession hook. */
453 		if (sp == NULL)
454 			continue;
455 
456 		/* Skip any sessions which are not in LISTEN mode. */
457 		if (sp->state != PPPOE_LISTENING)
458 			continue;
459 
460 		neg = sp->neg;
461 
462 		/* Empty Service-Name matches any service. */
463 		if (neg->service_len == 0)
464 			break;
465 
466 		/* Special case for a blank or "*" service name (wildcard). */
467 		if (neg->service_len == 1 && neg->service.data[0] == '*')
468 			break;
469 
470 		/* If the lengths don't match, that aint it. */
471 		if (neg->service_len != ntohs(tag->tag_len))
472 			continue;
473 
474 		if (strncmp(tag->tag_data, neg->service.data,
475 		    ntohs(tag->tag_len)) == 0)
476 			break;
477 	}
478 	CTR3(KTR_NET, "%20s: matched %p for %s", __func__, hook, tag->tag_data);
479 
480 	return (hook);
481 }
482 
483 /*
484  * Broadcast the PADI packet in m0 to all listening hooks.
485  * This routine is called when a PADI with empty Service-Name
486  * tag is received. Client should receive PADOs with all
487  * available services.
488  */
489 static int
490 pppoe_broadcast_padi(node_p node, struct mbuf *m0)
491 {
492 	hook_p hook;
493 	int error = 0;
494 
495 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
496 		sessp sp = NG_HOOK_PRIVATE(hook);
497 		struct mbuf *m;
498 
499 		/*
500 		 * Go through all listening hooks and
501 		 * broadcast the PADI packet up there
502 		 */
503 		if (sp == NULL)
504 			continue;
505 
506 		if (sp->state != PPPOE_LISTENING)
507 			continue;
508 
509 		m = m_dup(m0, M_DONTWAIT);
510 		if (m == NULL)
511 			return (ENOMEM);
512 		NG_SEND_DATA_ONLY(error, hook, m);
513 		if (error)
514 			return (error);
515 	}
516 
517 	return (0);
518 }
519 
520 /*
521  * Find a hook, which name equals to given service.
522  */
523 static hook_p
524 pppoe_find_svc(node_p node, const char *svc_name, int svc_len)
525 {
526 	hook_p	hook;
527 
528 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
529 		sessp sp = NG_HOOK_PRIVATE(hook);
530 		negp neg;
531 
532 		/* Skip any nonsession hook. */
533 		if (sp == NULL)
534 			continue;
535 
536 		/* Skip any sessions which are not in LISTEN mode. */
537 		if (sp->state != PPPOE_LISTENING)
538 			continue;
539 
540 		neg = sp->neg;
541 
542 		if (neg->service_len == svc_len &&
543 		    strncmp(svc_name, neg->service.data, svc_len == 0))
544 			return (hook);
545 	}
546 
547 	return (NULL);
548 }
549 
550 /**************************************************************************
551  * Routine to find a particular session that matches an incoming packet.  *
552  **************************************************************************/
553 static hook_p
554 pppoe_findsession(node_p node, const struct pppoe_full_hdr *wh)
555 {
556 	hook_p	hook = NULL;
557 	uint16_t session = ntohs(wh->ph.sid);
558 
559 	/*
560 	 * Find matching peer/session combination.
561 	 */
562 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
563 		sessp	sp = NG_HOOK_PRIVATE(hook);
564 
565 		/* Skip any nonsession hook. */
566 		if (sp == NULL)
567 			continue;
568 		if (sp->Session_ID == session &&
569 		    (sp->state == PPPOE_CONNECTED ||
570 		     sp->state == PPPOE_NEWCONNECTED) &&
571 		    bcmp(sp->pkt_hdr.eh.ether_dhost,
572 		     wh->eh.ether_shost, ETHER_ADDR_LEN) == 0) {
573 			break;
574 		}
575 	}
576 	CTR3(KTR_NET, "%20s: matched %p for %d", __func__, hook, session);
577 
578 	return (hook);
579 }
580 
581 static hook_p
582 pppoe_finduniq(node_p node, const struct pppoe_tag *tag)
583 {
584 	hook_p	hook = NULL;
585 	union uniq uniq;
586 
587 	bcopy(tag->tag_data, uniq.bytes, sizeof(void *));
588 	/* Cycle through all known hooks. */
589 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
590 		/* Skip any nonsession hook. */
591 		if (NG_HOOK_PRIVATE(hook) == NULL)
592 			continue;
593 		if (uniq.pointer == NG_HOOK_PRIVATE(hook))
594 			break;
595 	}
596 	CTR3(KTR_NET, "%20s: matched %p for %p", __func__, hook, uniq.pointer);
597 
598 	return (hook);
599 }
600 
601 /**************************************************************************
602  * Start of Netgraph entrypoints.					  *
603  **************************************************************************/
604 
605 /*
606  * Allocate the private data structure and link it with node.
607  */
608 static int
609 ng_pppoe_constructor(node_p node)
610 {
611 	priv_p privp;
612 
613 	/* Initialize private descriptor. */
614 	privp = malloc(sizeof(*privp), M_NETGRAPH_PPPOE, M_NOWAIT | M_ZERO);
615 	if (privp == NULL)
616 		return (ENOMEM);
617 
618 	/* Link structs together; this counts as our one reference to *node. */
619 	NG_NODE_SET_PRIVATE(node, privp);
620 	privp->node = node;
621 
622 	/* Initialize to standard mode. */
623 	memset(&privp->eh.ether_dhost, 0xff, ETHER_ADDR_LEN);
624 	privp->eh.ether_type = ETHERTYPE_PPPOE_DISC;
625 
626 	CTR3(KTR_NET, "%20s: created node [%x] (%p)",
627 	    __func__, node->nd_ID, node);
628 
629 	return (0);
630 }
631 
632 /*
633  * Give our ok for a hook to be added...
634  * point the hook's private info to the hook structure.
635  *
636  * The following hook names are special:
637  *  "ethernet":  the hook that should be connected to a NIC.
638  *  "debug":	copies of data sent out here  (when I write the code).
639  * All other hook names need only be unique. (the framework checks this).
640  */
641 static int
642 ng_pppoe_newhook(node_p node, hook_p hook, const char *name)
643 {
644 	const priv_p privp = NG_NODE_PRIVATE(node);
645 	sessp sp;
646 
647 	if (strcmp(name, NG_PPPOE_HOOK_ETHERNET) == 0) {
648 		privp->ethernet_hook = hook;
649 		NG_HOOK_SET_RCVDATA(hook, ng_pppoe_rcvdata_ether);
650 	} else if (strcmp(name, NG_PPPOE_HOOK_DEBUG) == 0) {
651 		privp->debug_hook = hook;
652 		NG_HOOK_SET_RCVDATA(hook, ng_pppoe_rcvdata_debug);
653 	} else {
654 		/*
655 		 * Any other unique name is OK.
656 		 * The infrastructure has already checked that it's unique,
657 		 * so just allocate it and hook it in.
658 		 */
659 		sp = malloc(sizeof(*sp), M_NETGRAPH_PPPOE, M_NOWAIT | M_ZERO);
660 		if (sp == NULL)
661 			return (ENOMEM);
662 
663 		NG_HOOK_SET_PRIVATE(hook, sp);
664 		sp->hook = hook;
665 	}
666 	CTR5(KTR_NET, "%20s: node [%x] (%p) connected hook %s (%p)",
667 	    __func__, node->nd_ID, node, name, hook);
668 
669 	return(0);
670 }
671 
672 /*
673  * Hook has been added successfully. Request the MAC address of
674  * the underlying Ethernet node.
675  */
676 static int
677 ng_pppoe_connect(hook_p hook)
678 {
679 	const priv_p privp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
680 	struct ng_mesg *msg;
681 	int error;
682 
683 	if (hook != privp->ethernet_hook)
684 		return (0);
685 
686 	/*
687 	 * If this is Ethernet hook, then request MAC address
688 	 * from our downstream.
689 	 */
690 	NG_MKMESSAGE(msg, NGM_ETHER_COOKIE, NGM_ETHER_GET_ENADDR, 0, M_NOWAIT);
691 	if (msg == NULL)
692 		return (ENOBUFS);
693 
694 	/*
695 	 * Our hook and peer hook have HK_INVALID flag set,
696 	 * so we can't use NG_SEND_MSG_HOOK() macro here.
697 	 */
698 	NG_SEND_MSG_ID(error, privp->node, msg,
699 	    NG_NODE_ID(NG_PEER_NODE(privp->ethernet_hook)),
700 	    NG_NODE_ID(privp->node));
701 
702 	return (error);
703 }
704 /*
705  * Get a netgraph control message.
706  * Check it is one we understand. If needed, send a response.
707  * We sometimes save the address for an async action later.
708  * Always free the message.
709  */
710 static int
711 ng_pppoe_rcvmsg(node_p node, item_p item, hook_p lasthook)
712 {
713 	priv_p privp = NG_NODE_PRIVATE(node);
714 	struct ngpppoe_init_data *ourmsg = NULL;
715 	struct ng_mesg *resp = NULL;
716 	int error = 0;
717 	hook_p hook = NULL;
718 	sessp sp = NULL;
719 	negp neg = NULL;
720 	struct ng_mesg *msg;
721 
722 	NGI_GET_MSG(item, msg);
723 	CTR5(KTR_NET, "%20s: node [%x] (%p) got message %d with cookie %d",
724 	    __func__, node->nd_ID, node, msg->header.cmd,
725 	    msg->header.typecookie);
726 
727 	/* Deal with message according to cookie and command. */
728 	switch (msg->header.typecookie) {
729 	case NGM_PPPOE_COOKIE:
730 		switch (msg->header.cmd) {
731 		case NGM_PPPOE_CONNECT:
732 		case NGM_PPPOE_LISTEN:
733 		case NGM_PPPOE_OFFER:
734 		case NGM_PPPOE_SERVICE:
735 			ourmsg = (struct ngpppoe_init_data *)msg->data;
736 			if (msg->header.arglen < sizeof(*ourmsg)) {
737 				log(LOG_ERR, "ng_pppoe[%x]: init data too "
738 				    "small\n", node->nd_ID);
739 				LEAVE(EMSGSIZE);
740 			}
741 			if (msg->header.arglen - sizeof(*ourmsg) >
742 			    PPPOE_SERVICE_NAME_SIZE) {
743 				log(LOG_ERR, "ng_pppoe[%x]: service name "
744 				    "too big\n", node->nd_ID);
745 				LEAVE(EMSGSIZE);
746 			}
747 			if (msg->header.arglen - sizeof(*ourmsg) <
748 			    ourmsg->data_len) {
749 				log(LOG_ERR, "ng_pppoe[%x]: init data has bad "
750 				    "length, %d should be %zd\n", node->nd_ID,
751 				    ourmsg->data_len,
752 				    msg->header.arglen - sizeof (*ourmsg));
753 				LEAVE(EMSGSIZE);
754 			}
755 
756 			/* Make sure strcmp will terminate safely. */
757 			ourmsg->hook[sizeof(ourmsg->hook) - 1] = '\0';
758 
759 			/* Cycle through all known hooks. */
760 			LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
761 				if (NG_HOOK_NAME(hook) &&
762 				    strcmp(NG_HOOK_NAME(hook), ourmsg->hook) ==
763 				    0)
764 					break;
765 			}
766 			if (hook == NULL)
767 				LEAVE(ENOENT);
768 
769 			sp = NG_HOOK_PRIVATE(hook);
770 
771 			if (sp == NULL)
772 				LEAVE(EINVAL);
773 
774 			if (msg->header.cmd == NGM_PPPOE_LISTEN) {
775 				/*
776 				 * Ensure we aren't already listening for this
777 				 * service.
778 				 */
779 				if (pppoe_find_svc(node, ourmsg->data,
780 				    ourmsg->data_len) != NULL)
781 					LEAVE(EEXIST);
782 			}
783 
784 			/*
785 			 * PPPOE_SERVICE advertisments are set up
786 			 * on sessions that are in PRIMED state.
787 			 */
788 			if (msg->header.cmd == NGM_PPPOE_SERVICE)
789 				break;
790 
791 			if (sp->state != PPPOE_SNONE) {
792 				log(LOG_NOTICE, "ng_pppoe[%x]: Session already "
793 				    "active\n", node->nd_ID);
794 				LEAVE(EISCONN);
795 			}
796 
797 			/*
798 			 * Set up prototype header.
799 			 */
800 			neg = malloc(sizeof(*neg), M_NETGRAPH_PPPOE,
801 			    M_NOWAIT | M_ZERO);
802 
803 			if (neg == NULL)
804 				LEAVE(ENOMEM);
805 
806 			neg->m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
807 			if (neg->m == NULL) {
808 				free(neg, M_NETGRAPH_PPPOE);
809 				LEAVE(ENOBUFS);
810 			}
811 			neg->m->m_pkthdr.rcvif = NULL;
812 			sp->neg = neg;
813 			ng_callout_init(&neg->handle);
814 			neg->m->m_len = sizeof(struct pppoe_full_hdr);
815 			neg->pkt = mtod(neg->m, union packet*);
816 			memcpy((void *)&neg->pkt->pkt_header.eh,
817 			    &privp->eh, sizeof(struct ether_header));
818 			neg->pkt->pkt_header.ph.ver = 0x1;
819 			neg->pkt->pkt_header.ph.type = 0x1;
820 			neg->pkt->pkt_header.ph.sid = 0x0000;
821 			neg->timeout = 0;
822 
823 			sp->creator = NGI_RETADDR(item);
824 		}
825 		switch (msg->header.cmd) {
826 		case NGM_PPPOE_GET_STATUS:
827 		    {
828 			struct ngpppoestat *stats;
829 
830 			NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT);
831 			if (!resp)
832 				LEAVE(ENOMEM);
833 
834 			stats = (struct ngpppoestat *) resp->data;
835 			stats->packets_in = privp->packets_in;
836 			stats->packets_out = privp->packets_out;
837 			break;
838 		    }
839 		case NGM_PPPOE_CONNECT:
840 			/*
841 			 * Check the hook exists and is Uninitialised.
842 			 * Send a PADI request, and start the timeout logic.
843 			 * Store the originator of this message so we can send
844 			 * a success of fail message to them later.
845 			 * Move the session to SINIT.
846 			 * Set up the session to the correct state and
847 			 * start it.
848 			 */
849 			neg->service.hdr.tag_type = PTT_SRV_NAME;
850 			neg->service.hdr.tag_len =
851 			    htons((uint16_t)ourmsg->data_len);
852 			if (ourmsg->data_len)
853 				bcopy(ourmsg->data, neg->service.data,
854 				    ourmsg->data_len);
855 			neg->service_len = ourmsg->data_len;
856 			pppoe_start(sp);
857 			break;
858 		case NGM_PPPOE_LISTEN:
859 			/*
860 			 * Check the hook exists and is Uninitialised.
861 			 * Install the service matching string.
862 			 * Store the originator of this message so we can send
863 			 * a success of fail message to them later.
864 			 * Move the hook to 'LISTENING'
865 			 */
866 			neg->service.hdr.tag_type = PTT_SRV_NAME;
867 			neg->service.hdr.tag_len =
868 			    htons((uint16_t)ourmsg->data_len);
869 
870 			if (ourmsg->data_len)
871 				bcopy(ourmsg->data, neg->service.data,
872 				    ourmsg->data_len);
873 			neg->service_len = ourmsg->data_len;
874 			neg->pkt->pkt_header.ph.code = PADT_CODE;
875 			/*
876 			 * Wait for PADI packet coming from Ethernet.
877 			 */
878 			sp->state = PPPOE_LISTENING;
879 			break;
880 		case NGM_PPPOE_OFFER:
881 			/*
882 			 * Check the hook exists and is Uninitialised.
883 			 * Store the originator of this message so we can send
884 			 * a success of fail message to them later.
885 			 * Store the AC-Name given and go to PRIMED.
886 			 */
887 			neg->ac_name.hdr.tag_type = PTT_AC_NAME;
888 			neg->ac_name.hdr.tag_len =
889 			    htons((uint16_t)ourmsg->data_len);
890 			if (ourmsg->data_len)
891 				bcopy(ourmsg->data, neg->ac_name.data,
892 				    ourmsg->data_len);
893 			neg->ac_name_len = ourmsg->data_len;
894 			neg->pkt->pkt_header.ph.code = PADO_CODE;
895 			/*
896 			 * Wait for PADI packet coming from hook.
897 			 */
898 			sp->state = PPPOE_PRIMED;
899 			break;
900 		case NGM_PPPOE_SERVICE:
901 			/*
902 			 * Check the session is primed.
903 			 * for now just allow ONE service to be advertised.
904 			 * If you do it twice you just overwrite.
905 			 */
906 			if (sp->state != PPPOE_PRIMED) {
907 				log(LOG_NOTICE, "ng_pppoe[%x]: session not "
908 				    "primed\n", node->nd_ID);
909 				LEAVE(EISCONN);
910 			}
911 			neg = sp->neg;
912 			neg->service.hdr.tag_type = PTT_SRV_NAME;
913 			neg->service.hdr.tag_len =
914 			    htons((uint16_t)ourmsg->data_len);
915 
916 			if (ourmsg->data_len)
917 				bcopy(ourmsg->data, neg->service.data,
918 				    ourmsg->data_len);
919 			neg->service_len = ourmsg->data_len;
920 			break;
921 		case NGM_PPPOE_SETMODE:
922 		    {
923 			char *s;
924 			size_t len;
925 
926 			if (msg->header.arglen == 0)
927 				LEAVE(EINVAL);
928 
929 			s = (char *)msg->data;
930 			len = msg->header.arglen - 1;
931 
932 			/* Search for matching mode string. */
933 			if (len == strlen(NG_PPPOE_STANDARD) &&
934 			    (strncmp(NG_PPPOE_STANDARD, s, len) == 0)) {
935 				privp->flags = 0;
936 				privp->eh.ether_type = ETHERTYPE_PPPOE_DISC;
937 				break;
938 			}
939 			if (len == strlen(NG_PPPOE_3COM) &&
940 			    (strncmp(NG_PPPOE_3COM, s, len) == 0)) {
941 				privp->flags |= COMPAT_3COM;
942 				privp->eh.ether_type =
943 				    ETHERTYPE_PPPOE_3COM_DISC;
944 				break;
945 			}
946 			if (len == strlen(NG_PPPOE_DLINK) &&
947 			    (strncmp(NG_PPPOE_DLINK, s, len) == 0)) {
948 				privp->flags |= COMPAT_DLINK;
949 				break;
950 			}
951 			error = EINVAL;
952 			break;
953 		    }
954 		case NGM_PPPOE_GETMODE:
955 		    {
956 			char *s;
957 			size_t len = 0;
958 
959 			if (privp->flags == 0)
960 				len += strlen(NG_PPPOE_STANDARD) + 1;
961 			if (privp->flags & COMPAT_3COM)
962 				len += strlen(NG_PPPOE_3COM) + 1;
963 			if (privp->flags & COMPAT_DLINK)
964 				len += strlen(NG_PPPOE_DLINK) + 1;
965 
966 			NG_MKRESPONSE(resp, msg, len, M_NOWAIT);
967 			if (resp == NULL)
968 				LEAVE(ENOMEM);
969 
970 			s = (char *)resp->data;
971 			if (privp->flags == 0) {
972 				len = strlen(NG_PPPOE_STANDARD);
973 				strlcpy(s, NG_PPPOE_STANDARD, len + 1);
974 				break;
975 			}
976 			if (privp->flags & COMPAT_3COM) {
977 				len = strlen(NG_PPPOE_3COM);
978 				strlcpy(s, NG_PPPOE_3COM, len + 1);
979 				s += len;
980 			}
981 			if (privp->flags & COMPAT_DLINK) {
982 				if (s != resp->data)
983 					*s++ = '|';
984 				len = strlen(NG_PPPOE_DLINK);
985 				strlcpy(s, NG_PPPOE_DLINK, len + 1);
986 			}
987 			break;
988 		    }
989 		case NGM_PPPOE_SETENADDR:
990 			if (msg->header.arglen != ETHER_ADDR_LEN)
991 				LEAVE(EINVAL);
992 			bcopy(msg->data, &privp->eh.ether_shost,
993 			    ETHER_ADDR_LEN);
994 			break;
995 		default:
996 			LEAVE(EINVAL);
997 		}
998 		break;
999 	case NGM_ETHER_COOKIE:
1000 		if (!(msg->header.flags & NGF_RESP))
1001 			LEAVE(EINVAL);
1002 		switch (msg->header.cmd) {
1003 		case NGM_ETHER_GET_ENADDR:
1004 			if (msg->header.arglen != ETHER_ADDR_LEN)
1005 				LEAVE(EINVAL);
1006 			bcopy(msg->data, &privp->eh.ether_shost,
1007 			    ETHER_ADDR_LEN);
1008 			break;
1009 		default:
1010 			LEAVE(EINVAL);
1011 		}
1012 		break;
1013 	default:
1014 		LEAVE(EINVAL);
1015 	}
1016 
1017 	/* Take care of synchronous response, if any. */
1018 quit:
1019 	CTR2(KTR_NET, "%20s: returning %d", __func__, error);
1020 	NG_RESPOND_MSG(error, node, item, resp);
1021 	/* Free the message and return. */
1022 	NG_FREE_MSG(msg);
1023 	return(error);
1024 }
1025 
1026 /*
1027  * Start a client into the first state. A separate function because
1028  * it can be needed if the negotiation times out.
1029  */
1030 static void
1031 pppoe_start(sessp sp)
1032 {
1033 	hook_p	hook = sp->hook;
1034 	node_p	node = NG_HOOK_NODE(hook);
1035 	priv_p	privp = NG_NODE_PRIVATE(node);
1036 	negp	neg = sp->neg;
1037 	struct {
1038 		struct pppoe_tag hdr;
1039 		union	uniq	data;
1040 	} __packed uniqtag;
1041 	struct  mbuf *m0;
1042 	int	error;
1043 
1044 	/*
1045 	 * Kick the state machine into starting up.
1046 	 */
1047 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
1048 	sp->state = PPPOE_SINIT;
1049 	/*
1050 	 * Reset the packet header to broadcast. Since we are
1051 	 * in a client mode use configured ethertype.
1052 	 */
1053 	memcpy((void *)&neg->pkt->pkt_header.eh, &privp->eh,
1054 	    sizeof(struct ether_header));
1055 	neg->pkt->pkt_header.ph.code = PADI_CODE;
1056 	uniqtag.hdr.tag_type = PTT_HOST_UNIQ;
1057 	uniqtag.hdr.tag_len = htons((u_int16_t)sizeof(uniqtag.data));
1058 	uniqtag.data.pointer = sp;
1059 	init_tags(sp);
1060 	insert_tag(sp, &uniqtag.hdr);
1061 	insert_tag(sp, &neg->service.hdr);
1062 	make_packet(sp);
1063 	/*
1064 	 * Send packet and prepare to retransmit it after timeout.
1065 	 */
1066 	ng_callout(&neg->handle, node, hook, PPPOE_INITIAL_TIMEOUT * hz,
1067 	    pppoe_ticker, NULL, 0);
1068 	neg->timeout = PPPOE_INITIAL_TIMEOUT * 2;
1069 	m0 = m_copypacket(neg->m, M_DONTWAIT);
1070 	NG_SEND_DATA_ONLY(error, privp->ethernet_hook, m0);
1071 }
1072 
1073 static int
1074 send_acname(sessp sp, const struct pppoe_tag *tag)
1075 {
1076 	int error, tlen;
1077 	struct ng_mesg *msg;
1078 	struct ngpppoe_sts *sts;
1079 
1080 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
1081 
1082 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_ACNAME,
1083 	    sizeof(struct ngpppoe_sts), M_NOWAIT);
1084 	if (msg == NULL)
1085 		return (ENOMEM);
1086 
1087 	sts = (struct ngpppoe_sts *)msg->data;
1088 	tlen = min(NG_HOOKSIZ - 1, ntohs(tag->tag_len));
1089 	strncpy(sts->hook, tag->tag_data, tlen);
1090 	sts->hook[tlen] = '\0';
1091 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, 0);
1092 
1093 	return (error);
1094 }
1095 
1096 static int
1097 send_sessionid(sessp sp)
1098 {
1099 	int error;
1100 	struct ng_mesg *msg;
1101 
1102 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
1103 
1104 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_SESSIONID,
1105 	    sizeof(uint16_t), M_NOWAIT);
1106 	if (msg == NULL)
1107 		return (ENOMEM);
1108 
1109 	*(uint16_t *)msg->data = sp->Session_ID;
1110 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, 0);
1111 
1112 	return (error);
1113 }
1114 
1115 /*
1116  * Receive data from session hook and do something with it.
1117  */
1118 static int
1119 ng_pppoe_rcvdata(hook_p hook, item_p item)
1120 {
1121 	node_p			node = NG_HOOK_NODE(hook);
1122 	const priv_p		privp = NG_NODE_PRIVATE(node);
1123 	sessp			sp = NG_HOOK_PRIVATE(hook);
1124 	struct pppoe_full_hdr	*wh;
1125 	struct mbuf		*m;
1126 	int			error;
1127 
1128 	CTR6(KTR_NET, "%20s: node [%x] (%p) received %p on \"%s\" (%p)",
1129 	    __func__, node->nd_ID, node, item, hook->hk_name, hook);
1130 
1131 	NGI_GET_M(item, m);
1132 	switch (sp->state) {
1133 	case	PPPOE_NEWCONNECTED:
1134 	case	PPPOE_CONNECTED: {
1135 		static const u_char addrctrl[] = { 0xff, 0x03 };
1136 
1137 		/*
1138 		 * Remove PPP address and control fields, if any.
1139 		 * For example, ng_ppp(4) always sends LCP packets
1140 		 * with address and control fields as required by
1141 		 * generic PPP. PPPoE is an exception to the rule.
1142 		 */
1143 		if (m->m_pkthdr.len >= 2) {
1144 			if (m->m_len < 2 && !(m = m_pullup(m, 2)))
1145 				LEAVE(ENOBUFS);
1146 			if (bcmp(mtod(m, u_char *), addrctrl, 2) == 0)
1147 				m_adj(m, 2);
1148 		}
1149 		/*
1150 		 * Bang in a pre-made header, and set the length up
1151 		 * to be correct. Then send it to the ethernet driver.
1152 		 */
1153 		M_PREPEND(m, sizeof(*wh), M_DONTWAIT);
1154 		if (m == NULL)
1155 			LEAVE(ENOBUFS);
1156 
1157 		wh = mtod(m, struct pppoe_full_hdr *);
1158 		bcopy(&sp->pkt_hdr, wh, sizeof(*wh));
1159 		wh->ph.length = htons(m->m_pkthdr.len - sizeof(*wh));
1160 		NG_FWD_NEW_DATA(error, item, privp->ethernet_hook, m);
1161 		privp->packets_out++;
1162 		break;
1163 		}
1164 	case	PPPOE_PRIMED: {
1165 		struct {
1166 			struct pppoe_tag hdr;
1167 			union	uniq	data;
1168 		} __packed 	uniqtag;
1169 		const struct pppoe_tag	*tag;
1170 		struct mbuf 	*m0;
1171 		const struct pppoe_hdr	*ph;
1172 		negp		neg = sp->neg;
1173 	        uint16_t	session;
1174 		uint16_t	length;
1175 		uint8_t		code;
1176 
1177 		/*
1178 		 * A PADI packet is being returned by the application
1179 		 * that has set up this hook. This indicates that it
1180 		 * wants us to offer service.
1181 		 */
1182 		if (m->m_len < sizeof(*wh)) {
1183 			m = m_pullup(m, sizeof(*wh));
1184 			if (m == NULL)
1185 				LEAVE(ENOBUFS);
1186 		}
1187 		wh = mtod(m, struct pppoe_full_hdr *);
1188 		ph = &wh->ph;
1189 		session = ntohs(wh->ph.sid);
1190 		length = ntohs(wh->ph.length);
1191 		code = wh->ph.code;
1192 		/* Use peers mode in session. */
1193 		neg->pkt->pkt_header.eh.ether_type = wh->eh.ether_type;
1194 		if (code != PADI_CODE)
1195 			LEAVE(EINVAL);
1196 		ng_uncallout(&neg->handle, node);
1197 
1198 		/*
1199 		 * This is the first time we hear
1200 		 * from the client, so note it's
1201 		 * unicast address, replacing the
1202 		 * broadcast address.
1203 		 */
1204 		bcopy(wh->eh.ether_shost,
1205 			neg->pkt->pkt_header.eh.ether_dhost,
1206 			ETHER_ADDR_LEN);
1207 		sp->state = PPPOE_SOFFER;
1208 		neg->timeout = 0;
1209 		neg->pkt->pkt_header.ph.code = PADO_CODE;
1210 
1211 		/*
1212 		 * Start working out the tags to respond with.
1213 		 */
1214 		uniqtag.hdr.tag_type = PTT_AC_COOKIE;
1215 		uniqtag.hdr.tag_len = htons((u_int16_t)sizeof(sp));
1216 		uniqtag.data.pointer = sp;
1217 		init_tags(sp);
1218 		insert_tag(sp, &neg->ac_name.hdr); /* AC_NAME */
1219 		if ((tag = get_tag(ph, PTT_SRV_NAME)))
1220 			insert_tag(sp, tag);	  /* return service */
1221 		/*
1222 		 * If we have a NULL service request
1223 		 * and have an extra service defined in this hook,
1224 		 * then also add a tag for the extra service.
1225 		 * XXX this is a hack. eventually we should be able
1226 		 * to support advertising many services, not just one
1227 		 */
1228 		if (((tag == NULL) || (tag->tag_len == 0)) &&
1229 		    (neg->service.hdr.tag_len != 0)) {
1230 			insert_tag(sp, &neg->service.hdr); /* SERVICE */
1231 		}
1232 		if ((tag = get_tag(ph, PTT_HOST_UNIQ)))
1233 			insert_tag(sp, tag); /* returned hostunique */
1234 		insert_tag(sp, &uniqtag.hdr);
1235 		scan_tags(sp, ph);
1236 		make_packet(sp);
1237 		/*
1238 		 * Send the offer but if they don't respond
1239 		 * in PPPOE_OFFER_TIMEOUT seconds, forget about it.
1240 		 */
1241 		ng_callout(&neg->handle, node, hook, PPPOE_OFFER_TIMEOUT * hz,
1242 		    pppoe_ticker, NULL, 0);
1243 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1244 		NG_FWD_NEW_DATA(error, item, privp->ethernet_hook, m0);
1245 		privp->packets_out++;
1246 		break;
1247 		}
1248 
1249 	/*
1250 	 * Packets coming from the hook make no sense
1251 	 * to sessions in the rest of states. Throw them away.
1252 	 */
1253 	default:
1254 		LEAVE(ENETUNREACH);
1255 	}
1256 quit:
1257 	if (item)
1258 		NG_FREE_ITEM(item);
1259 	NG_FREE_M(m);
1260 	return (error);
1261 }
1262 
1263 /*
1264  * Receive data from ether and do something with it.
1265  */
1266 static int
1267 ng_pppoe_rcvdata_ether(hook_p hook, item_p item)
1268 {
1269 	node_p			node = NG_HOOK_NODE(hook);
1270 	const priv_p		privp = NG_NODE_PRIVATE(node);
1271 	sessp			sp = NG_HOOK_PRIVATE(hook);
1272 	const struct pppoe_tag	*utag = NULL, *tag = NULL;
1273 	const struct pppoe_full_hdr *wh;
1274 	const struct pppoe_hdr	*ph;
1275 	negp			neg = NULL;
1276 	struct mbuf		*m;
1277 	hook_p 			sendhook;
1278 	int			error = 0;
1279 	uint16_t		session;
1280 	uint16_t		length;
1281 	uint8_t			code;
1282 	struct	mbuf 		*m0;
1283 
1284 	CTR6(KTR_NET, "%20s: node [%x] (%p) received %p on \"%s\" (%p)",
1285 	    __func__, node->nd_ID, node, item, hook->hk_name, hook);
1286 
1287 	NGI_GET_M(item, m);
1288 	/*
1289 	 * Dig out various fields from the packet.
1290 	 * Use them to decide where to send it.
1291 	 */
1292 	privp->packets_in++;
1293 	if( m->m_len < sizeof(*wh)) {
1294 		m = m_pullup(m, sizeof(*wh)); /* Checks length */
1295 		if (m == NULL) {
1296 			log(LOG_NOTICE, "ng_pppoe[%x]: couldn't "
1297 			    "m_pullup(wh)\n", node->nd_ID);
1298 			LEAVE(ENOBUFS);
1299 		}
1300 	}
1301 	wh = mtod(m, struct pppoe_full_hdr *);
1302 	length = ntohs(wh->ph.length);
1303 	switch(wh->eh.ether_type) {
1304 	case	ETHERTYPE_PPPOE_3COM_DISC: /* fall through */
1305 	case	ETHERTYPE_PPPOE_DISC:
1306 		/*
1307 		 * We need to try to make sure that the tag area
1308 		 * is contiguous, or we could wander off the end
1309 		 * of a buffer and make a mess.
1310 		 * (Linux wouldn't have this problem).
1311 		 */
1312 		if (m->m_pkthdr.len <= MHLEN) {
1313 			if( m->m_len < m->m_pkthdr.len) {
1314 				m = m_pullup(m, m->m_pkthdr.len);
1315 				if (m == NULL) {
1316 					log(LOG_NOTICE, "ng_pppoe[%x]: "
1317 					    "couldn't m_pullup(pkthdr)\n",
1318 					    node->nd_ID);
1319 					LEAVE(ENOBUFS);
1320 				}
1321 			}
1322 		}
1323 		if (m->m_len != m->m_pkthdr.len) {
1324 			/*
1325 			 * It's not all in one piece.
1326 			 * We need to do extra work.
1327 			 * Put it into a cluster.
1328 			 */
1329 			struct mbuf *n;
1330 			n = m_dup(m, M_DONTWAIT);
1331 			m_freem(m);
1332 			m = n;
1333 			if (m) {
1334 				/* just check we got a cluster */
1335 				if (m->m_len != m->m_pkthdr.len) {
1336 					m_freem(m);
1337 					m = NULL;
1338 				}
1339 			}
1340 			if (m == NULL) {
1341 				log(LOG_NOTICE, "ng_pppoe[%x]: packet "
1342 				    "fragmented\n", node->nd_ID);
1343 				LEAVE(EMSGSIZE);
1344 			}
1345 		}
1346 		wh = mtod(m, struct pppoe_full_hdr *);
1347 		length = ntohs(wh->ph.length);
1348 		ph = &wh->ph;
1349 		session = ntohs(wh->ph.sid);
1350 		code = wh->ph.code;
1351 
1352 		switch(code) {
1353 		case	PADI_CODE:
1354 			/*
1355 			 * We are a server:
1356 			 * Look for a hook with the required service and send
1357 			 * the ENTIRE packet up there. It should come back to
1358 			 * a new hook in PRIMED state. Look there for further
1359 			 * processing.
1360 			 */
1361 			tag = get_tag(ph, PTT_SRV_NAME);
1362 			if (tag == NULL) {
1363 				CTR1(KTR_NET, "%20s: PADI w/o Service-Name",
1364 				    __func__);
1365 				LEAVE(ENETUNREACH);
1366 			}
1367 
1368 			/*
1369 			 * First, try to match Service-Name against our
1370 			 * listening hooks. If no success and we are in D-Link
1371 			 * compat mode and Service-Name is empty, then we
1372 			 * broadcast the PADI to all listening hooks.
1373 			 */
1374 			sendhook = pppoe_match_svc(node, tag);
1375 			if (sendhook != NULL)
1376 				NG_FWD_NEW_DATA(error, item, sendhook, m);
1377 			else if (privp->flags & COMPAT_DLINK &&
1378 				 ntohs(tag->tag_len) == 0)
1379 				error = pppoe_broadcast_padi(node, m);
1380 			else
1381 				error = ENETUNREACH;
1382 			break;
1383 		case	PADO_CODE:
1384 			/*
1385 			 * We are a client:
1386 			 * Use the host_uniq tag to find the hook this is in
1387 			 * response to. Received #2, now send #3
1388 			 * For now simply accept the first we receive.
1389 			 */
1390 			utag = get_tag(ph, PTT_HOST_UNIQ);
1391 			if ((utag == NULL) ||
1392 			    (ntohs(utag->tag_len) != sizeof(sp))) {
1393 				log(LOG_NOTICE, "ng_pppoe[%x]: no host "
1394 				    "unique field\n", node->nd_ID);
1395 				LEAVE(ENETUNREACH);
1396 			}
1397 
1398 			sendhook = pppoe_finduniq(node, utag);
1399 			if (sendhook == NULL) {
1400 				log(LOG_NOTICE, "ng_pppoe[%x]: no "
1401 				    "matching session\n", node->nd_ID);
1402 				LEAVE(ENETUNREACH);
1403 			}
1404 
1405 			/*
1406 			 * Check the session is in the right state.
1407 			 * It needs to be in PPPOE_SINIT.
1408 			 */
1409 			sp = NG_HOOK_PRIVATE(sendhook);
1410 			if (sp->state != PPPOE_SINIT) {
1411 				log(LOG_NOTICE, "ng_pppoe[%x]: session "
1412 				    "in wrong state\n", node->nd_ID);
1413 				LEAVE(ENETUNREACH);
1414 			}
1415 			neg = sp->neg;
1416 			ng_uncallout(&neg->handle, node);
1417 
1418 			/*
1419 			 * This is the first time we hear
1420 			 * from the server, so note it's
1421 			 * unicast address, replacing the
1422 			 * broadcast address .
1423 			 */
1424 			bcopy(wh->eh.ether_shost,
1425 				neg->pkt->pkt_header.eh.ether_dhost,
1426 				ETHER_ADDR_LEN);
1427 			neg->timeout = 0;
1428 			neg->pkt->pkt_header.ph.code = PADR_CODE;
1429 			init_tags(sp);
1430 			insert_tag(sp, utag);      	/* Host Unique */
1431 			if ((tag = get_tag(ph, PTT_AC_COOKIE)))
1432 				insert_tag(sp, tag); 	/* return cookie */
1433 			if ((tag = get_tag(ph, PTT_AC_NAME))) {
1434 				insert_tag(sp, tag); 	/* return it */
1435 				send_acname(sp, tag);
1436 			}
1437 			insert_tag(sp, &neg->service.hdr); /* Service */
1438 			scan_tags(sp, ph);
1439 			make_packet(sp);
1440 			sp->state = PPPOE_SREQ;
1441 			ng_callout(&neg->handle, node, sp->hook,
1442 			    PPPOE_INITIAL_TIMEOUT * hz,
1443 			    pppoe_ticker, NULL, 0);
1444 			neg->timeout = PPPOE_INITIAL_TIMEOUT * 2;
1445 			m0 = m_copypacket(neg->m, M_DONTWAIT);
1446 			NG_FWD_NEW_DATA(error, item, privp->ethernet_hook, m0);
1447 			break;
1448 		case	PADR_CODE:
1449 			/*
1450 			 * We are a server:
1451 			 * Use the ac_cookie tag to find the
1452 			 * hook this is in response to.
1453 			 */
1454 			utag = get_tag(ph, PTT_AC_COOKIE);
1455 			if ((utag == NULL) ||
1456 			    (ntohs(utag->tag_len) != sizeof(sp))) {
1457 				LEAVE(ENETUNREACH);
1458 			}
1459 
1460 			sendhook = pppoe_finduniq(node, utag);
1461 			if (sendhook == NULL)
1462 				LEAVE(ENETUNREACH);
1463 
1464 			/*
1465 			 * Check the session is in the right state.
1466 			 * It needs to be in PPPOE_SOFFER or PPPOE_NEWCONNECTED.
1467 			 * If the latter, then this is a retry by the client,
1468 			 * so be nice, and resend.
1469 			 */
1470 			sp = NG_HOOK_PRIVATE(sendhook);
1471 			if (sp->state == PPPOE_NEWCONNECTED) {
1472 				/*
1473 				 * Whoa! drop back to resend that PADS packet.
1474 				 * We should still have a copy of it.
1475 				 */
1476 				sp->state = PPPOE_SOFFER;
1477 			}
1478 			if (sp->state != PPPOE_SOFFER)
1479 				LEAVE (ENETUNREACH);
1480 			neg = sp->neg;
1481 			ng_uncallout(&neg->handle, node);
1482 			neg->pkt->pkt_header.ph.code = PADS_CODE;
1483 			if (sp->Session_ID == 0)
1484 				neg->pkt->pkt_header.ph.sid =
1485 				    htons(sp->Session_ID
1486 					= get_new_sid(node));
1487 			send_sessionid(sp);
1488 			neg->timeout = 0;
1489 			/*
1490 			 * start working out the tags to respond with.
1491 			 */
1492 			init_tags(sp);
1493 			insert_tag(sp, &neg->ac_name.hdr); /* AC_NAME */
1494 			if ((tag = get_tag(ph, PTT_SRV_NAME)))
1495 				insert_tag(sp, tag);/* return service */
1496 			if ((tag = get_tag(ph, PTT_HOST_UNIQ)))
1497 				insert_tag(sp, tag); /* return it */
1498 			insert_tag(sp, utag);	/* ac_cookie */
1499 			scan_tags(sp, ph);
1500 			make_packet(sp);
1501 			sp->state = PPPOE_NEWCONNECTED;
1502 
1503 			/* Send the PADS without a timeout - we're now connected. */
1504 			m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1505 			NG_FWD_NEW_DATA(error, item, privp->ethernet_hook, m0);
1506 
1507 			/*
1508 			 * Having sent the last Negotiation header,
1509 			 * Set up the stored packet header to be correct for
1510 			 * the actual session. But keep the negotialtion stuff
1511 			 * around in case we need to resend this last packet.
1512 			 * We'll discard it when we move from NEWCONNECTED
1513 			 * to CONNECTED
1514 			 */
1515 			sp->pkt_hdr = neg->pkt->pkt_header;
1516 			/* Configure ethertype depending on what
1517 			 * ethertype was used at discovery phase */
1518 			if (sp->pkt_hdr.eh.ether_type ==
1519 			    ETHERTYPE_PPPOE_3COM_DISC)
1520 				sp->pkt_hdr.eh.ether_type
1521 					= ETHERTYPE_PPPOE_3COM_SESS;
1522 			else
1523 				sp->pkt_hdr.eh.ether_type
1524 					= ETHERTYPE_PPPOE_SESS;
1525 			sp->pkt_hdr.ph.code = 0;
1526 			pppoe_send_event(sp, NGM_PPPOE_SUCCESS);
1527 			break;
1528 		case	PADS_CODE:
1529 			/*
1530 			 * We are a client:
1531 			 * Use the host_uniq tag to find the hook this is in
1532 			 * response to. Take the session ID and store it away.
1533 			 * Also make sure the pre-made header is correct and
1534 			 * set us into Session mode.
1535 			 */
1536 			utag = get_tag(ph, PTT_HOST_UNIQ);
1537 			if ((utag == NULL) ||
1538 			    (ntohs(utag->tag_len) != sizeof(sp))) {
1539 				LEAVE (ENETUNREACH);
1540 			}
1541 			sendhook = pppoe_finduniq(node, utag);
1542 			if (sendhook == NULL)
1543 				LEAVE(ENETUNREACH);
1544 
1545 			/*
1546 			 * Check the session is in the right state.
1547 			 * It needs to be in PPPOE_SREQ.
1548 			 */
1549 			sp = NG_HOOK_PRIVATE(sendhook);
1550 			if (sp->state != PPPOE_SREQ)
1551 				LEAVE(ENETUNREACH);
1552 			neg = sp->neg;
1553 			ng_uncallout(&neg->handle, node);
1554 			neg->pkt->pkt_header.ph.sid = wh->ph.sid;
1555 			sp->Session_ID = ntohs(wh->ph.sid);
1556 			send_sessionid(sp);
1557 			neg->timeout = 0;
1558 			sp->state = PPPOE_CONNECTED;
1559 			/*
1560 			 * Now we have gone to Connected mode,
1561 			 * Free all resources needed for negotiation.
1562 			 * Keep a copy of the header we will be using.
1563 			 */
1564 			sp->pkt_hdr = neg->pkt->pkt_header;
1565 			if (privp->flags & COMPAT_3COM)
1566 				sp->pkt_hdr.eh.ether_type
1567 					= ETHERTYPE_PPPOE_3COM_SESS;
1568 			else
1569 				sp->pkt_hdr.eh.ether_type
1570 					= ETHERTYPE_PPPOE_SESS;
1571 			sp->pkt_hdr.ph.code = 0;
1572 			m_freem(neg->m);
1573 			free(sp->neg, M_NETGRAPH_PPPOE);
1574 			sp->neg = NULL;
1575 			pppoe_send_event(sp, NGM_PPPOE_SUCCESS);
1576 			break;
1577 		case	PADT_CODE:
1578 			/*
1579 			 * Find matching peer/session combination.
1580 			 */
1581 			sendhook = pppoe_findsession(node, wh);
1582 			if (sendhook == NULL)
1583 				LEAVE(ENETUNREACH);
1584 			/* Disconnect that hook. */
1585 			ng_rmhook_self(sendhook);
1586 			break;
1587 		default:
1588 			LEAVE(EPFNOSUPPORT);
1589 		}
1590 		break;
1591 	case	ETHERTYPE_PPPOE_3COM_SESS:
1592 	case	ETHERTYPE_PPPOE_SESS:
1593 		/*
1594 		 * Find matching peer/session combination.
1595 		 */
1596 		sendhook = pppoe_findsession(node, wh);
1597 		if (sendhook == NULL)
1598 			LEAVE (ENETUNREACH);
1599 		sp = NG_HOOK_PRIVATE(sendhook);
1600 		m_adj(m, sizeof(*wh));
1601 
1602 		/* If packet too short, dump it. */
1603 		if (m->m_pkthdr.len < length)
1604 			LEAVE(EMSGSIZE);
1605 		/* Also need to trim excess at the end */
1606 		if (m->m_pkthdr.len > length) {
1607 			m_adj(m, -((int)(m->m_pkthdr.len - length)));
1608 		}
1609 		if ( sp->state != PPPOE_CONNECTED) {
1610 			if (sp->state == PPPOE_NEWCONNECTED) {
1611 				sp->state = PPPOE_CONNECTED;
1612 				/*
1613 				 * Now we have gone to Connected mode,
1614 				 * Free all resources needed for negotiation.
1615 				 * Be paranoid about whether there may be
1616 				 * a timeout.
1617 				 */
1618 				m_freem(sp->neg->m);
1619 				ng_uncallout(&sp->neg->handle, node);
1620 				free(sp->neg, M_NETGRAPH_PPPOE);
1621 				sp->neg = NULL;
1622 			} else {
1623 				LEAVE (ENETUNREACH);
1624 			}
1625 		}
1626 		NG_FWD_NEW_DATA(error, item, sendhook, m);
1627 		break;
1628 	default:
1629 		LEAVE(EPFNOSUPPORT);
1630 	}
1631 quit:
1632 	if (item)
1633 		NG_FREE_ITEM(item);
1634 	NG_FREE_M(m);
1635 	return (error);
1636 }
1637 
1638 /*
1639  * Receive data from debug hook and bypass it to ether.
1640  */
1641 static int
1642 ng_pppoe_rcvdata_debug(hook_p hook, item_p item)
1643 {
1644 	node_p		node = NG_HOOK_NODE(hook);
1645 	const priv_p	privp = NG_NODE_PRIVATE(node);
1646 	int		error;
1647 
1648 	CTR6(KTR_NET, "%20s: node [%x] (%p) received %p on \"%s\" (%p)",
1649 	    __func__, node->nd_ID, node, item, hook->hk_name, hook);
1650 
1651 	NG_FWD_ITEM_HOOK(error, item, privp->ethernet_hook);
1652 	privp->packets_out++;
1653 	return (error);
1654 }
1655 
1656 /*
1657  * Do local shutdown processing..
1658  * If we are a persistant device, we might refuse to go away, and
1659  * we'd only remove our links and reset ourself.
1660  */
1661 static int
1662 ng_pppoe_shutdown(node_p node)
1663 {
1664 	const priv_p privdata = NG_NODE_PRIVATE(node);
1665 
1666 	NG_NODE_SET_PRIVATE(node, NULL);
1667 	NG_NODE_UNREF(privdata->node);
1668 	free(privdata, M_NETGRAPH_PPPOE);
1669 	return (0);
1670 }
1671 
1672 /*
1673  * Hook disconnection
1674  *
1675  * Clean up all dangling links and information about the session/hook.
1676  * For this type, removal of the last link destroys the node.
1677  */
1678 static int
1679 ng_pppoe_disconnect(hook_p hook)
1680 {
1681 	node_p node = NG_HOOK_NODE(hook);
1682 	priv_p privp = NG_NODE_PRIVATE(node);
1683 	sessp	sp;
1684 
1685 	if (hook == privp->debug_hook) {
1686 		privp->debug_hook = NULL;
1687 	} else if (hook == privp->ethernet_hook) {
1688 		privp->ethernet_hook = NULL;
1689 		if (NG_NODE_IS_VALID(node))
1690 			ng_rmnode_self(node);
1691 	} else {
1692 		sp = NG_HOOK_PRIVATE(hook);
1693 		if (sp->state != PPPOE_SNONE ) {
1694 			pppoe_send_event(sp, NGM_PPPOE_CLOSE);
1695 		}
1696 		/*
1697 		 * According to the spec, if we are connected,
1698 		 * we should send a DISC packet if we are shutting down
1699 		 * a session.
1700 		 */
1701 		if ((privp->ethernet_hook)
1702 		&& ((sp->state == PPPOE_CONNECTED)
1703 		 || (sp->state == PPPOE_NEWCONNECTED))) {
1704 			struct mbuf *m;
1705 
1706 			/* Generate a packet of that type. */
1707 			MGETHDR(m, M_DONTWAIT, MT_DATA);
1708 			if (m == NULL)
1709 				log(LOG_NOTICE, "ng_pppoe[%x]: session out of "
1710 				    "mbufs\n", node->nd_ID);
1711 			else {
1712 				struct pppoe_full_hdr *wh;
1713 				struct pppoe_tag *tag;
1714 				int	msglen = strlen(SIGNOFF);
1715 				int	error = 0;
1716 
1717 				m->m_pkthdr.rcvif = NULL;
1718 				m->m_pkthdr.len = m->m_len = sizeof(*wh);
1719 				wh = mtod(m, struct pppoe_full_hdr *);
1720 				bcopy(&sp->pkt_hdr, wh, sizeof(*wh));
1721 
1722 				/* Revert the stored header to DISC/PADT mode. */
1723 				wh->ph.code = PADT_CODE;
1724 				/*
1725 				 * Configure ethertype depending on what
1726 				 * was used during sessions stage.
1727 				 */
1728 				if (wh->eh.ether_type ==
1729 				    ETHERTYPE_PPPOE_3COM_SESS)
1730 					wh->eh.ether_type = ETHERTYPE_PPPOE_3COM_DISC;
1731 				else
1732 					wh->eh.ether_type = ETHERTYPE_PPPOE_DISC;
1733 				/*
1734 				 * Add a General error message and adjust
1735 				 * sizes.
1736 				 */
1737 				tag = wh->ph.tag;
1738 				tag->tag_type = PTT_GEN_ERR;
1739 				tag->tag_len = htons((u_int16_t)msglen);
1740 				strncpy(tag->tag_data, SIGNOFF, msglen);
1741 				m->m_pkthdr.len = (m->m_len += sizeof(*tag) +
1742 				    msglen);
1743 				wh->ph.length = htons(sizeof(*tag) + msglen);
1744 				NG_SEND_DATA_ONLY(error,
1745 					privp->ethernet_hook, m);
1746 			}
1747 		}
1748 		/*
1749 		 * As long as we have somewhere to store the timeout handle,
1750 		 * we may have a timeout pending.. get rid of it.
1751 		 */
1752 		if (sp->neg) {
1753 			ng_uncallout(&sp->neg->handle, node);
1754 			if (sp->neg->m)
1755 				m_freem(sp->neg->m);
1756 			free(sp->neg, M_NETGRAPH_PPPOE);
1757 		}
1758 		free(sp, M_NETGRAPH_PPPOE);
1759 		NG_HOOK_SET_PRIVATE(hook, NULL);
1760 	}
1761 	if ((NG_NODE_NUMHOOKS(node) == 0) &&
1762 	    (NG_NODE_IS_VALID(node)))
1763 		ng_rmnode_self(node);
1764 	return (0);
1765 }
1766 
1767 /*
1768  * Timeouts come here.
1769  */
1770 static void
1771 pppoe_ticker(node_p node, hook_p hook, void *arg1, int arg2)
1772 {
1773 	priv_p privp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
1774 	sessp	sp = NG_HOOK_PRIVATE(hook);
1775 	negp	neg = sp->neg;
1776 	struct mbuf *m0 = NULL;
1777 	int	error = 0;
1778 
1779 	CTR6(KTR_NET, "%20s: node [%x] (%p) hook \"%s\" (%p) session %d",
1780 	    __func__, node->nd_ID, node, hook->hk_name, hook, sp->Session_ID);
1781 	switch(sp->state) {
1782 		/*
1783 		 * Resend the last packet, using an exponential backoff.
1784 		 * After a period of time, stop growing the backoff,
1785 		 * And either leave it, or revert to the start.
1786 		 */
1787 	case	PPPOE_SINIT:
1788 	case	PPPOE_SREQ:
1789 		/* Timeouts on these produce resends. */
1790 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1791 		NG_SEND_DATA_ONLY( error, privp->ethernet_hook, m0);
1792 		ng_callout(&neg->handle, node, hook, neg->timeout * hz,
1793 		    pppoe_ticker, NULL, 0);
1794 		if ((neg->timeout <<= 1) > PPPOE_TIMEOUT_LIMIT) {
1795 			if (sp->state == PPPOE_SREQ) {
1796 				/* Revert to SINIT mode. */
1797 				pppoe_start(sp);
1798 			} else {
1799 				neg->timeout = PPPOE_TIMEOUT_LIMIT;
1800 			}
1801 		}
1802 		break;
1803 	case	PPPOE_PRIMED:
1804 	case	PPPOE_SOFFER:
1805 		/* A timeout on these says "give up" */
1806 		ng_rmhook_self(hook);
1807 		break;
1808 	default:
1809 		/* Timeouts have no meaning in other states. */
1810 		log(LOG_NOTICE, "ng_pppoe[%x]: unexpected timeout\n",
1811 		    node->nd_ID);
1812 	}
1813 }
1814 
1815 /*
1816  * Parse an incoming packet to see if any tags should be copied to the
1817  * output packet. Don't do any tags that have been handled in the main
1818  * state machine.
1819  */
1820 static const struct pppoe_tag*
1821 scan_tags(sessp	sp, const struct pppoe_hdr* ph)
1822 {
1823 	const char *const end = (const char *)next_tag(ph);
1824 	const char *ptn;
1825 	const struct pppoe_tag *pt = &ph->tag[0];
1826 
1827 	/*
1828 	 * Keep processing tags while a tag header will still fit.
1829 	 */
1830 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
1831 
1832 	while((const char*)(pt + 1) <= end) {
1833 		/*
1834 		 * If the tag data would go past the end of the packet, abort.
1835 		 */
1836 		ptn = (((const char *)(pt + 1)) + ntohs(pt->tag_len));
1837 		if(ptn > end)
1838 			return NULL;
1839 
1840 		switch (pt->tag_type) {
1841 		case	PTT_RELAY_SID:
1842 			insert_tag(sp, pt);
1843 			break;
1844 		case	PTT_EOL:
1845 			return NULL;
1846 		case	PTT_SRV_NAME:
1847 		case	PTT_AC_NAME:
1848 		case	PTT_HOST_UNIQ:
1849 		case	PTT_AC_COOKIE:
1850 		case	PTT_VENDOR:
1851 		case	PTT_SRV_ERR:
1852 		case	PTT_SYS_ERR:
1853 		case	PTT_GEN_ERR:
1854 			break;
1855 		}
1856 		pt = (const struct pppoe_tag*)ptn;
1857 	}
1858 	return NULL;
1859 }
1860 
1861 static	int
1862 pppoe_send_event(sessp sp, enum cmd cmdid)
1863 {
1864 	int error;
1865 	struct ng_mesg *msg;
1866 	struct ngpppoe_sts *sts;
1867 
1868 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
1869 
1870 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, cmdid,
1871 			sizeof(struct ngpppoe_sts), M_NOWAIT);
1872 	if (msg == NULL)
1873 		return (ENOMEM);
1874 	sts = (struct ngpppoe_sts *)msg->data;
1875 	strncpy(sts->hook, NG_HOOK_NAME(sp->hook), NG_HOOKSIZ);
1876 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, 0);
1877 	return (error);
1878 }
1879