xref: /freebsd/sys/netgraph/ng_pppoe.c (revision 87569f75a91f298c52a71823c04d41cf53c88889)
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 <net/ethernet.h>
52 
53 #include <netgraph/ng_message.h>
54 #include <netgraph/netgraph.h>
55 #include <netgraph/ng_parse.h>
56 #include <netgraph/ng_pppoe.h>
57 
58 #ifdef NG_SEPARATE_MALLOC
59 MALLOC_DEFINE(M_NETGRAPH_PPPOE, "netgraph_pppoe", "netgraph pppoe node");
60 #else
61 #define M_NETGRAPH_PPPOE M_NETGRAPH
62 #endif
63 
64 #define SIGNOFF "session closed"
65 #define OFFSETOF(s, e) ((char *)&((s *)0)->e - (char *)((s *)0))
66 
67 /*
68  * This section contains the netgraph method declarations for the
69  * pppoe node. These methods define the netgraph pppoe 'type'.
70  */
71 
72 static ng_constructor_t	ng_pppoe_constructor;
73 static ng_rcvmsg_t	ng_pppoe_rcvmsg;
74 static ng_shutdown_t	ng_pppoe_shutdown;
75 static ng_newhook_t	ng_pppoe_newhook;
76 static ng_rcvdata_t	ng_pppoe_rcvdata;
77 static ng_disconnect_t	ng_pppoe_disconnect;
78 
79 /* Parse type for struct ngpppoe_init_data */
80 static const struct ng_parse_struct_field ngpppoe_init_data_type_fields[]
81 	= NG_PPPOE_INIT_DATA_TYPE_INFO;
82 static const struct ng_parse_type ngpppoe_init_data_state_type = {
83 	&ng_parse_struct_type,
84 	&ngpppoe_init_data_type_fields
85 };
86 
87 /* Parse type for struct ngpppoe_sts */
88 static const struct ng_parse_struct_field ng_pppoe_sts_type_fields[]
89 	= NG_PPPOE_STS_TYPE_INFO;
90 static const struct ng_parse_type ng_pppoe_sts_state_type = {
91 	&ng_parse_struct_type,
92 	&ng_pppoe_sts_type_fields
93 };
94 
95 /* List of commands and how to convert arguments to/from ASCII */
96 static const struct ng_cmdlist ng_pppoe_cmds[] = {
97 	{
98 	  NGM_PPPOE_COOKIE,
99 	  NGM_PPPOE_CONNECT,
100 	  "pppoe_connect",
101 	  &ngpppoe_init_data_state_type,
102 	  NULL
103 	},
104 	{
105 	  NGM_PPPOE_COOKIE,
106 	  NGM_PPPOE_LISTEN,
107 	  "pppoe_listen",
108 	  &ngpppoe_init_data_state_type,
109 	  NULL
110 	},
111 	{
112 	  NGM_PPPOE_COOKIE,
113 	  NGM_PPPOE_OFFER,
114 	  "pppoe_offer",
115 	  &ngpppoe_init_data_state_type,
116 	  NULL
117 	},
118 	{
119 	  NGM_PPPOE_COOKIE,
120 	  NGM_PPPOE_SERVICE,
121 	  "pppoe_service",
122 	  &ngpppoe_init_data_state_type,
123 	  NULL
124 	},
125 	{
126 	  NGM_PPPOE_COOKIE,
127 	  NGM_PPPOE_SUCCESS,
128 	  "pppoe_success",
129 	  &ng_pppoe_sts_state_type,
130 	  NULL
131 	},
132 	{
133 	  NGM_PPPOE_COOKIE,
134 	  NGM_PPPOE_FAIL,
135 	  "pppoe_fail",
136 	  &ng_pppoe_sts_state_type,
137 	  NULL
138 	},
139 	{
140 	  NGM_PPPOE_COOKIE,
141 	  NGM_PPPOE_CLOSE,
142 	  "pppoe_close",
143 	  &ng_pppoe_sts_state_type,
144 	  NULL
145 	},
146 	{
147 	  NGM_PPPOE_COOKIE,
148 	  NGM_PPPOE_SETMODE,
149 	  "pppoe_setmode",
150 	  &ng_parse_string_type,
151 	  NULL
152 	},
153 	{
154 	  NGM_PPPOE_COOKIE,
155 	  NGM_PPPOE_GETMODE,
156 	  "pppoe_getmode",
157 	  NULL,
158 	  &ng_parse_string_type
159 	},
160 	{ 0 }
161 };
162 
163 /* Netgraph node type descriptor */
164 static struct ng_type typestruct = {
165 	.version =	NG_ABI_VERSION,
166 	.name =		NG_PPPOE_NODE_TYPE,
167 	.constructor =	ng_pppoe_constructor,
168 	.rcvmsg =	ng_pppoe_rcvmsg,
169 	.shutdown =	ng_pppoe_shutdown,
170 	.newhook =	ng_pppoe_newhook,
171 	.rcvdata =	ng_pppoe_rcvdata,
172 	.disconnect =	ng_pppoe_disconnect,
173 	.cmdlist =	ng_pppoe_cmds,
174 };
175 NETGRAPH_INIT(pppoe, &typestruct);
176 
177 /*
178  * States for the session state machine.
179  * These have no meaning if there is no hook attached yet.
180  */
181 enum state {
182     PPPOE_SNONE=0,	/* [both] Initial state */
183     PPPOE_LISTENING,	/* [Daemon] Listening for discover initiation pkt */
184     PPPOE_SINIT,	/* [Client] Sent discovery initiation */
185     PPPOE_PRIMED,	/* [Server] Awaiting PADI from daemon */
186     PPPOE_SOFFER,	/* [Server] Sent offer message  (got PADI)*/
187     PPPOE_SREQ,		/* [Client] Sent a Request */
188     PPPOE_NEWCONNECTED,	/* [Server] Connection established, No data received */
189     PPPOE_CONNECTED,	/* [Both] Connection established, Data received */
190     PPPOE_DEAD		/* [Both] */
191 };
192 
193 #define NUMTAGS 20 /* number of tags we are set up to work with */
194 
195 /*
196  * Information we store for each hook on each node for negotiating the
197  * session. The mbuf and cluster are freed once negotiation has completed.
198  * The whole negotiation block is then discarded.
199  */
200 
201 struct sess_neg {
202 	struct mbuf 		*m; /* holds cluster with last sent packet */
203 	union	packet		*pkt; /* points within the above cluster */
204 	struct callout		handle;   /* see timeout(9) */
205 	u_int			timeout; /* 0,1,2,4,8,16 etc. seconds */
206 	u_int			numtags;
207 	const struct pppoe_tag	*tags[NUMTAGS];
208 	u_int			service_len;
209 	u_int			ac_name_len;
210 
211 	struct datatag		service;
212 	struct datatag		ac_name;
213 };
214 typedef struct sess_neg *negp;
215 
216 /*
217  * Session information that is needed after connection.
218  */
219 struct sess_con {
220 	hook_p  		hook;
221 	uint16_t		Session_ID;
222 	enum state		state;
223 	ng_ID_t			creator;	/* who to notify */
224 	struct pppoe_full_hdr	pkt_hdr;	/* used when connected */
225 	negp			neg;		/* used when negotiating */
226 };
227 typedef struct sess_con *sessp;
228 
229 #define	NG_PPPOE_SESSION_NODE(sp) NG_HOOK_NODE(sp->hook)
230 
231 static const struct ether_header eh_standard =
232 	{{0xff,0xff,0xff,0xff,0xff,0xff},
233 	{0x00,0x00,0x00,0x00,0x00,0x00},
234 	ETHERTYPE_PPPOE_DISC};
235 
236 static const struct ether_header eh_3Com =
237 	{{0xff,0xff,0xff,0xff,0xff,0xff},
238 	{0x00,0x00,0x00,0x00,0x00,0x00},
239 	ETHERTYPE_PPPOE_3COM_DISC};
240 
241 /*
242  * Information we store for each node
243  */
244 struct PPPoE {
245 	node_p		node;		/* back pointer to node */
246 	hook_p  	ethernet_hook;
247 	hook_p  	debug_hook;
248 	u_int   	packets_in;	/* packets in from ethernet */
249 	u_int   	packets_out;	/* packets out towards ethernet */
250 	uint32_t	flags;
251 #define	COMPAT_3COM	0x00000001
252 #define	COMPAT_DLINK	0x00000002
253 	const struct	ether_header	*eh;	/* standard PPPoE or 3Com? */
254 };
255 typedef struct PPPoE *priv_p;
256 
257 union uniq {
258 	char bytes[sizeof(void *)];
259 	void *pointer;
260 };
261 
262 #define	LEAVE(x) do { error = x; goto quit; } while(0)
263 static void	pppoe_start(sessp sp);
264 static void	sendpacket(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 	priv_p privp = NG_NODE_PRIVATE(node);
283 	static int pppoe_sid = 10;
284 	sessp sp;
285 	hook_p	hook;
286 	uint16_t val;
287 
288 restart:
289 	val = pppoe_sid++;
290 	/*
291 	 * Spec says 0xFFFF is reserved.
292 	 * Also don't use 0x0000
293 	 */
294 	if (val == 0xffff) {
295 		pppoe_sid = 20;
296 		goto restart;
297 	}
298 
299 	/* Check it isn't already in use. */
300 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
301 		/* Don't check special hooks. */
302 		if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook)
303 		||  (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook))
304 			continue;
305 		sp = NG_HOOK_PRIVATE(hook);
306 		if (sp->Session_ID == val)
307 			goto restart;
308 	}
309 
310 	CTR2(KTR_NET, "%20s: new sid %d", __func__, val);
311 
312 	return (val);
313 }
314 
315 
316 /*
317  * Return the location where the next tag can be put
318  */
319 static __inline const struct pppoe_tag*
320 next_tag(const struct pppoe_hdr* ph)
321 {
322 	return (const struct pppoe_tag*)(((const char*)&ph->tag[0])
323 	    + ntohs(ph->length));
324 }
325 
326 /*
327  * Look for a tag of a specific type.
328  * Don't trust any length the other end says,
329  * but assume we already sanity checked ph->length.
330  */
331 static const struct pppoe_tag*
332 get_tag(const struct pppoe_hdr* ph, uint16_t idx)
333 {
334 	const char *const end = (const char *)next_tag(ph);
335 	const struct pppoe_tag *pt = &ph->tag[0];
336 	const char *ptn;
337 
338 	/*
339 	 * Keep processing tags while a tag header will still fit.
340 	 */
341 	while((const char*)(pt + 1) <= end) {
342 		/*
343 		 * If the tag data would go past the end of the packet, abort.
344 		 */
345 		ptn = (((const char *)(pt + 1)) + ntohs(pt->tag_len));
346 		if (ptn > end) {
347 			CTR2(KTR_NET, "%20s: invalid length for tag %d",
348 			    __func__, idx);
349 			return (NULL);
350 		}
351 		if (pt->tag_type == idx) {
352 			CTR2(KTR_NET, "%20s: found tag %d", __func__, idx);
353 			return (pt);
354 		}
355 
356 		pt = (const struct pppoe_tag*)ptn;
357 	}
358 
359 	CTR2(KTR_NET, "%20s: not found tag %d", __func__, idx);
360 	return (NULL);
361 }
362 
363 /**************************************************************************
364  * Inlines to initialise or add tags to a session's tag list.
365  **************************************************************************/
366 /*
367  * Initialise the session's tag list.
368  */
369 static void
370 init_tags(sessp sp)
371 {
372 	KASSERT(sp->neg != NULL, ("%s: no neg", __func__));
373 	sp->neg->numtags = 0;
374 }
375 
376 static void
377 insert_tag(sessp sp, const struct pppoe_tag *tp)
378 {
379 	negp neg = sp->neg;
380 	int i;
381 
382 	KASSERT(neg != NULL, ("%s: no neg", __func__));
383 	if ((i = neg->numtags++) < NUMTAGS) {
384 		neg->tags[i] = tp;
385 	} else {
386 		printf("pppoe: asked to add too many tags to packet\n");
387 		neg->numtags--;
388 	}
389 }
390 
391 /*
392  * Make up a packet, using the tags filled out for the session.
393  *
394  * Assume that the actual pppoe header and ethernet header
395  * are filled out externally to this routine.
396  * Also assume that neg->wh points to the correct
397  * location at the front of the buffer space.
398  */
399 static void
400 make_packet(sessp sp) {
401 	struct pppoe_full_hdr *wh = &sp->neg->pkt->pkt_header;
402 	const struct pppoe_tag **tag;
403 	char *dp;
404 	int count;
405 	int tlen;
406 	uint16_t length = 0;
407 
408 	KASSERT((sp->neg != NULL) && (sp->neg->m != NULL),
409 	    ("%s: make_packet called from wrong state", __func__));
410 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
411 
412 	dp = (char *)wh->ph.tag;
413 	for (count = 0, tag = sp->neg->tags;
414 	    ((count < sp->neg->numtags) && (count < NUMTAGS));
415 	    tag++, count++) {
416 		tlen = ntohs((*tag)->tag_len) + sizeof(**tag);
417 		if ((length + tlen) > (ETHER_MAX_LEN - 4 - sizeof(*wh))) {
418 			printf("pppoe: tags too long\n");
419 			sp->neg->numtags = count;
420 			break;	/* XXX chop off what's too long */
421 		}
422 		bcopy(*tag, (char *)dp, tlen);
423 		length += tlen;
424 		dp += tlen;
425 	}
426  	wh->ph.length = htons(length);
427 	sp->neg->m->m_len = length + sizeof(*wh);
428 	sp->neg->m->m_pkthdr.len = length + sizeof(*wh);
429 }
430 
431 /**************************************************************************
432  * Routines to match a service.						  *
433  **************************************************************************/
434 
435 /*
436  * Find a hook that has a service string that matches that
437  * we are seeking. For now use a simple string.
438  * In the future we may need something like regexp().
439  *
440  * Null string is a wildcard (ANY service), according to RFC2516.
441  * And historical FreeBSD wildcard is also "*".
442  */
443 
444 static hook_p
445 pppoe_match_svc(node_p node, const struct pppoe_tag *tag)
446 {
447 	priv_p privp = NG_NODE_PRIVATE(node);
448 	hook_p hook;
449 
450 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
451 		sessp sp = NG_HOOK_PRIVATE(hook);
452 		negp neg;
453 
454 		/* Skip any hook that is debug or ethernet. */
455 		if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook) ||
456 		    (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook))
457 			continue;
458 
459 		/* Skip any sessions which are not in LISTEN mode. */
460 		if (sp->state != PPPOE_LISTENING)
461 			continue;
462 
463 		neg = sp->neg;
464 
465 		/* Empty Service-Name matches any service. */
466 		if (neg->service_len == 0)
467 			break;
468 
469 		/* Special case for a blank or "*" service name (wildcard). */
470 		if (neg->service_len == 1 && neg->service.data[0] == '*')
471 			break;
472 
473 		/* If the lengths don't match, that aint it. */
474 		if (neg->service_len != ntohs(tag->tag_len))
475 			continue;
476 
477 		if (strncmp(tag->tag_data, neg->service.data,
478 		    ntohs(tag->tag_len)) == 0)
479 			break;
480 	}
481 	CTR3(KTR_NET, "%20s: matched %p for %s", __func__, hook, tag->tag_data);
482 
483 	return (hook);
484 }
485 
486 /*
487  * Broadcast the PADI packet in m0 to all listening hooks.
488  * This routine is called when a PADI with empty Service-Name
489  * tag is received. Client should receive PADOs with all
490  * available services.
491  */
492 static int
493 pppoe_broadcast_padi(node_p node, struct mbuf *m0)
494 {
495 	priv_p privp = NG_NODE_PRIVATE(node);
496 	hook_p hook;
497 	int error = 0;
498 
499 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
500 		sessp sp = NG_HOOK_PRIVATE(hook);
501 		struct mbuf *m;
502 
503 		/*
504 		 * Go through all listening hooks and
505 		 * broadcast the PADI packet up there
506 		 */
507 		if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook) ||
508 		    (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook))
509 			continue;
510 
511 		if (sp->state != PPPOE_LISTENING)
512 			continue;
513 
514 		m = m_dup(m0, M_DONTWAIT);
515 		if (m == NULL)
516 			return (ENOMEM);
517 		NG_SEND_DATA_ONLY(error, hook, m);
518 		if (error)
519 			return (error);
520 	}
521 
522 	return (0);
523 }
524 
525 /*
526  * Find a hook, which name equals to given service.
527  */
528 static hook_p
529 pppoe_find_svc(node_p node, const char *svc_name, int svc_len)
530 {
531 	priv_p privp = NG_NODE_PRIVATE(node);
532 	hook_p	hook;
533 
534 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
535 		sessp sp = NG_HOOK_PRIVATE(hook);
536 		negp neg;
537 
538 		/* Skip any hook that is debug or ethernet. */
539 		if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook) ||
540 		    (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook))
541 			continue;
542 
543 		/* Skip any sessions which are not in LISTEN mode. */
544 		if (sp->state != PPPOE_LISTENING)
545 			continue;
546 
547 		neg = sp->neg;
548 
549 		if (neg->service_len == svc_len &&
550 		    strncmp(svc_name, neg->service.data, svc_len == 0))
551 			return (hook);
552 	}
553 
554 	return (NULL);
555 }
556 
557 /**************************************************************************
558  * Routine to find a particular session that matches an incoming packet.  *
559  **************************************************************************/
560 static hook_p
561 pppoe_findsession(node_p node, const struct pppoe_full_hdr *wh)
562 {
563 	priv_p	privp = NG_NODE_PRIVATE(node);
564 	sessp	sp = NULL;
565 	hook_p	hook = NULL;
566 	uint16_t session = ntohs(wh->ph.sid);
567 
568 	/*
569 	 * Find matching peer/session combination.
570 	 */
571 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
572 		/* don't check special hooks */
573 		if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook)
574 		||  (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook)) {
575 			continue;
576 		}
577 		sp = NG_HOOK_PRIVATE(hook);
578 		if ( ( (sp->state == PPPOE_CONNECTED)
579 		    || (sp->state == PPPOE_NEWCONNECTED) )
580 		&& (sp->Session_ID == session)
581 		&& (bcmp(sp->pkt_hdr.eh.ether_dhost,
582 		    wh->eh.ether_shost,
583 		    ETHER_ADDR_LEN)) == 0) {
584 			break;
585 		}
586 	}
587 	CTR3(KTR_NET, "%20s: matched %p for %d", __func__, hook, session);
588 
589 	return (hook);
590 }
591 
592 static hook_p
593 pppoe_finduniq(node_p node, const struct pppoe_tag *tag)
594 {
595 	priv_p	privp = NG_NODE_PRIVATE(node);
596 	hook_p	hook = NULL;
597 	union uniq uniq;
598 
599 	bcopy(tag->tag_data, uniq.bytes, sizeof(void *));
600 	/* Cycle through all known hooks. */
601 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
602 		/* Don't check special hooks. */
603 		if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook)
604 		||  (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook))
605 			continue;
606 		if (uniq.pointer == NG_HOOK_PRIVATE(hook))
607 			break;
608 	}
609 	CTR3(KTR_NET, "%20s: matched %p for %p", __func__, hook, uniq.pointer);
610 
611 	return (hook);
612 }
613 
614 /**************************************************************************
615  * Start of Netgraph entrypoints.					  *
616  **************************************************************************/
617 
618 /*
619  * Allocate the private data structure and link it with node.
620  */
621 static int
622 ng_pppoe_constructor(node_p node)
623 {
624 	priv_p privp;
625 
626 	/* Initialize private descriptor. */
627 	privp = malloc(sizeof(*privp), M_NETGRAPH_PPPOE, M_NOWAIT | M_ZERO);
628 	if (privp == NULL)
629 		return (ENOMEM);
630 
631 	/* Link structs together; this counts as our one reference to *node. */
632 	NG_NODE_SET_PRIVATE(node, privp);
633 	privp->node = node;
634 
635 	/* Initialize to standard mode. */
636 	privp->eh = &eh_standard;
637 
638 	CTR3(KTR_NET, "%20s: created node [%x] (%p)",
639 	    __func__, node->nd_ID, node);
640 
641 	return (0);
642 }
643 
644 /*
645  * Give our ok for a hook to be added...
646  * point the hook's private info to the hook structure.
647  *
648  * The following hook names are special:
649  *  "ethernet":  the hook that should be connected to a NIC.
650  *  "debug":	copies of data sent out here  (when I write the code).
651  * All other hook names need only be unique. (the framework checks this).
652  */
653 static int
654 ng_pppoe_newhook(node_p node, hook_p hook, const char *name)
655 {
656 	const priv_p privp = NG_NODE_PRIVATE(node);
657 	sessp sp;
658 
659 	if (strcmp(name, NG_PPPOE_HOOK_ETHERNET) == 0) {
660 		privp->ethernet_hook = hook;
661 		NG_HOOK_SET_PRIVATE(hook, &privp->ethernet_hook);
662 	} else if (strcmp(name, NG_PPPOE_HOOK_DEBUG) == 0) {
663 		privp->debug_hook = hook;
664 		NG_HOOK_SET_PRIVATE(hook, &privp->debug_hook);
665 	} else {
666 		/*
667 		 * Any other unique name is OK.
668 		 * The infrastructure has already checked that it's unique,
669 		 * so just allocate it and hook it in.
670 		 */
671 		sp = malloc(sizeof(*sp), M_NETGRAPH_PPPOE, M_NOWAIT | M_ZERO);
672 		if (sp == NULL)
673 			return (ENOMEM);
674 
675 		NG_HOOK_SET_PRIVATE(hook, sp);
676 		sp->hook = hook;
677 	}
678 	CTR5(KTR_NET, "%20s: node [%x] (%p) connected hook %s (%p)",
679 	    __func__, node->nd_ID, node, name, hook);
680 
681 	return(0);
682 }
683 
684 /*
685  * Get a netgraph control message.
686  * Check it is one we understand. If needed, send a response.
687  * We sometimes save the address for an async action later.
688  * Always free the message.
689  */
690 static int
691 ng_pppoe_rcvmsg(node_p node, item_p item, hook_p lasthook)
692 {
693 	priv_p privp = NG_NODE_PRIVATE(node);
694 	struct ngpppoe_init_data *ourmsg = NULL;
695 	struct ng_mesg *resp = NULL;
696 	int error = 0;
697 	hook_p hook = NULL;
698 	sessp sp = NULL;
699 	negp neg = NULL;
700 	struct ng_mesg *msg;
701 
702 	NGI_GET_MSG(item, msg);
703 	CTR5(KTR_NET, "%20s: node [%x] (%p) got message %d with cookie %d",
704 	    __func__, node->nd_ID, node, msg->header.cmd,
705 	    msg->header.typecookie);
706 
707 	/* Deal with message according to cookie and command. */
708 	switch (msg->header.typecookie) {
709 	case NGM_PPPOE_COOKIE:
710 		switch (msg->header.cmd) {
711 		case NGM_PPPOE_CONNECT:
712 		case NGM_PPPOE_LISTEN:
713 		case NGM_PPPOE_OFFER:
714 		case NGM_PPPOE_SERVICE:
715 			ourmsg = (struct ngpppoe_init_data *)msg->data;
716 			if (msg->header.arglen < sizeof(*ourmsg)) {
717 				printf("pppoe: init data too small\n");
718 				LEAVE(EMSGSIZE);
719 			}
720 			if (msg->header.arglen - sizeof(*ourmsg) >
721 			    PPPOE_SERVICE_NAME_SIZE) {
722 				printf("pppoe_rcvmsg: service name too big");
723 				LEAVE(EMSGSIZE);
724 			}
725 			if (msg->header.arglen - sizeof(*ourmsg) <
726 			    ourmsg->data_len) {
727 				printf("pppoe: init data has bad length,"
728 				    " %d should be %zd\n", ourmsg->data_len,
729 				    msg->header.arglen - sizeof (*ourmsg));
730 				LEAVE(EMSGSIZE);
731 			}
732 
733 			/* Make sure strcmp will terminate safely. */
734 			ourmsg->hook[sizeof(ourmsg->hook) - 1] = '\0';
735 
736 			/* Cycle through all known hooks. */
737 			LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
738 				if (NG_HOOK_NAME(hook) &&
739 				    strcmp(NG_HOOK_NAME(hook), ourmsg->hook) ==
740 				    0)
741 					break;
742 			}
743 			if (hook == NULL)
744 				LEAVE(ENOENT);
745 
746 			if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook) ||
747 			    (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook))
748 				LEAVE(EINVAL);
749 
750 			sp = NG_HOOK_PRIVATE(hook);
751 
752 			if (msg->header.cmd == NGM_PPPOE_LISTEN) {
753 				/*
754 				 * Ensure we aren't already listening for this
755 				 * service.
756 				 */
757 				if (pppoe_find_svc(node, ourmsg->data,
758 				    ourmsg->data_len) != NULL)
759 					LEAVE(EEXIST);
760 			}
761 
762 			/*
763 			 * PPPOE_SERVICE advertisments are set up
764 			 * on sessions that are in PRIMED state.
765 			 */
766 			if (msg->header.cmd == NGM_PPPOE_SERVICE)
767 				break;
768 
769 			if (sp->state != PPPOE_SNONE) {
770 				printf("pppoe: Session already active\n");
771 				LEAVE(EISCONN);
772 			}
773 
774 			/*
775 			 * Set up prototype header.
776 			 */
777 			neg = malloc(sizeof(*neg), M_NETGRAPH_PPPOE,
778 			    M_NOWAIT | M_ZERO);
779 
780 			if (neg == NULL)
781 				LEAVE(ENOMEM);
782 
783 			neg->m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
784 			if (neg->m == NULL) {
785 				free(neg, M_NETGRAPH_PPPOE);
786 				LEAVE(ENOBUFS);
787 			}
788 			neg->m->m_pkthdr.rcvif = NULL;
789 			sp->neg = neg;
790 			ng_callout_init(&neg->handle);
791 			neg->m->m_len = sizeof(struct pppoe_full_hdr);
792 			neg->pkt = mtod(neg->m, union packet*);
793 			memcpy((void *)&neg->pkt->pkt_header.eh,
794 			    (const void *)privp->eh,
795 			    sizeof(struct ether_header));
796 			neg->pkt->pkt_header.ph.ver = 0x1;
797 			neg->pkt->pkt_header.ph.type = 0x1;
798 			neg->pkt->pkt_header.ph.sid = 0x0000;
799 			neg->timeout = 0;
800 
801 			sp->creator = NGI_RETADDR(item);
802 		}
803 		switch (msg->header.cmd) {
804 		case NGM_PPPOE_GET_STATUS:
805 		    {
806 			struct ngpppoestat *stats;
807 
808 			NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT);
809 			if (!resp)
810 				LEAVE(ENOMEM);
811 
812 			stats = (struct ngpppoestat *) resp->data;
813 			stats->packets_in = privp->packets_in;
814 			stats->packets_out = privp->packets_out;
815 			break;
816 		    }
817 		case NGM_PPPOE_CONNECT:
818 			/*
819 			 * Check the hook exists and is Uninitialised.
820 			 * Send a PADI request, and start the timeout logic.
821 			 * Store the originator of this message so we can send
822 			 * a success of fail message to them later.
823 			 * Move the session to SINIT.
824 			 * Set up the session to the correct state and
825 			 * start it.
826 			 */
827 			neg->service.hdr.tag_type = PTT_SRV_NAME;
828 			neg->service.hdr.tag_len =
829 			    htons((uint16_t)ourmsg->data_len);
830 			if (ourmsg->data_len)
831 				bcopy(ourmsg->data, neg->service.data,
832 				    ourmsg->data_len);
833 			neg->service_len = ourmsg->data_len;
834 			pppoe_start(sp);
835 			break;
836 		case NGM_PPPOE_LISTEN:
837 			/*
838 			 * Check the hook exists and is Uninitialised.
839 			 * Install the service matching string.
840 			 * Store the originator of this message so we can send
841 			 * a success of fail message to them later.
842 			 * Move the hook to 'LISTENING'
843 			 */
844 			neg->service.hdr.tag_type = PTT_SRV_NAME;
845 			neg->service.hdr.tag_len =
846 			    htons((uint16_t)ourmsg->data_len);
847 
848 			if (ourmsg->data_len)
849 				bcopy(ourmsg->data, neg->service.data,
850 				    ourmsg->data_len);
851 			neg->service_len = ourmsg->data_len;
852 			neg->pkt->pkt_header.ph.code = PADT_CODE;
853 			/*
854 			 * Wait for PADI packet coming from Ethernet.
855 			 */
856 			sp->state = PPPOE_LISTENING;
857 			break;
858 		case NGM_PPPOE_OFFER:
859 			/*
860 			 * Check the hook exists and is Uninitialised.
861 			 * Store the originator of this message so we can send
862 			 * a success of fail message to them later.
863 			 * Store the AC-Name given and go to PRIMED.
864 			 */
865 			neg->ac_name.hdr.tag_type = PTT_AC_NAME;
866 			neg->ac_name.hdr.tag_len =
867 			    htons((uint16_t)ourmsg->data_len);
868 			if (ourmsg->data_len)
869 				bcopy(ourmsg->data, neg->ac_name.data,
870 				    ourmsg->data_len);
871 			neg->ac_name_len = ourmsg->data_len;
872 			neg->pkt->pkt_header.ph.code = PADO_CODE;
873 			/*
874 			 * Wait for PADI packet coming from hook.
875 			 */
876 			sp->state = PPPOE_PRIMED;
877 			break;
878 		case NGM_PPPOE_SERVICE:
879 			/*
880 			 * Check the session is primed.
881 			 * for now just allow ONE service to be advertised.
882 			 * If you do it twice you just overwrite.
883 			 */
884 			if (sp->state != PPPOE_PRIMED) {
885 				printf("pppoe: Session not primed\n");
886 				LEAVE(EISCONN);
887 			}
888 			neg = sp->neg;
889 			neg->service.hdr.tag_type = PTT_SRV_NAME;
890 			neg->service.hdr.tag_len =
891 			    htons((uint16_t)ourmsg->data_len);
892 
893 			if (ourmsg->data_len)
894 				bcopy(ourmsg->data, neg->service.data,
895 				    ourmsg->data_len);
896 			neg->service_len = ourmsg->data_len;
897 			break;
898 		case NGM_PPPOE_SETMODE:
899 		    {
900 			char *s;
901 			size_t len;
902 
903 			if (msg->header.arglen == 0)
904 				LEAVE(EINVAL);
905 
906 			s = (char *)msg->data;
907 			len = msg->header.arglen - 1;
908 
909 			/* Search for matching mode string. */
910 			if (len == strlen(NG_PPPOE_STANDARD) &&
911 			    (strncmp(NG_PPPOE_STANDARD, s, len) == 0)) {
912 				privp->flags = 0;
913 				privp->eh = &eh_standard;
914 				break;
915 			}
916 			if (len == strlen(NG_PPPOE_3COM) &&
917 			    (strncmp(NG_PPPOE_3COM, s, len) == 0)) {
918 				privp->flags |= COMPAT_3COM;
919 				privp->eh = &eh_3Com;
920 				break;
921 			}
922 			if (len == strlen(NG_PPPOE_DLINK) &&
923 			    (strncmp(NG_PPPOE_DLINK, s, len) == 0)) {
924 				privp->flags |= COMPAT_DLINK;
925 				break;
926 			}
927 			error = EINVAL;
928 			break;
929 		    }
930 		case NGM_PPPOE_GETMODE:
931 		    {
932 			char *s;
933 			size_t len = 0;
934 
935 			if (privp->flags == 0)
936 				len += strlen(NG_PPPOE_STANDARD) + 1;
937 			if (privp->flags & COMPAT_3COM)
938 				len += strlen(NG_PPPOE_3COM) + 1;
939 			if (privp->flags & COMPAT_DLINK)
940 				len += strlen(NG_PPPOE_DLINK) + 1;
941 
942 			NG_MKRESPONSE(resp, msg, len, M_NOWAIT);
943 			if (resp == NULL)
944 				LEAVE(ENOMEM);
945 
946 			s = (char *)resp->data;
947 			if (privp->flags == 0) {
948 				len = strlen(NG_PPPOE_STANDARD);
949 				strlcpy(s, NG_PPPOE_STANDARD, len + 1);
950 				break;
951 			}
952 			if (privp->flags & COMPAT_3COM) {
953 				len = strlen(NG_PPPOE_3COM);
954 				strlcpy(s, NG_PPPOE_3COM, len + 1);
955 				s += len;
956 			}
957 			if (privp->flags & COMPAT_DLINK) {
958 				if (s != resp->data)
959 					*s++ = '|';
960 				len = strlen(NG_PPPOE_DLINK);
961 				strlcpy(s, NG_PPPOE_DLINK, len + 1);
962 			}
963 			break;
964 		    }
965 		default:
966 			LEAVE(EINVAL);
967 		}
968 		break;
969 	default:
970 		LEAVE(EINVAL);
971 	}
972 
973 	/* Take care of synchronous response, if any. */
974 quit:
975 	CTR2(KTR_NET, "%20s: returning %d", __func__, error);
976 	NG_RESPOND_MSG(error, node, item, resp);
977 	/* Free the message and return. */
978 	NG_FREE_MSG(msg);
979 	return(error);
980 }
981 
982 /*
983  * Start a client into the first state. A separate function because
984  * it can be needed if the negotiation times out.
985  */
986 static void
987 pppoe_start(sessp sp)
988 {
989 	priv_p	privp = NG_NODE_PRIVATE(NG_PPPOE_SESSION_NODE(sp));
990 	struct {
991 		struct pppoe_tag hdr;
992 		union	uniq	data;
993 	} __packed uniqtag;
994 
995 	/*
996 	 * Kick the state machine into starting up.
997 	 */
998 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
999 	sp->state = PPPOE_SINIT;
1000 	/*
1001 	 * Reset the packet header to broadcast. Since we are
1002 	 * in a client
1003 	 * mode use configured ethertype.
1004 	 */
1005 	memcpy((void *)&sp->neg->pkt->pkt_header.eh,
1006 	    (const void *)privp->eh, sizeof(struct ether_header));
1007 	sp->neg->pkt->pkt_header.ph.code = PADI_CODE;
1008 	uniqtag.hdr.tag_type = PTT_HOST_UNIQ;
1009 	uniqtag.hdr.tag_len = htons((u_int16_t)sizeof(uniqtag.data));
1010 	uniqtag.data.pointer = sp;
1011 	init_tags(sp);
1012 	insert_tag(sp, &uniqtag.hdr);
1013 	insert_tag(sp, &sp->neg->service.hdr);
1014 	make_packet(sp);
1015 	sendpacket(sp);
1016 }
1017 
1018 static int
1019 send_acname(sessp sp, const struct pppoe_tag *tag)
1020 {
1021 	int error, tlen;
1022 	struct ng_mesg *msg;
1023 	struct ngpppoe_sts *sts;
1024 
1025 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
1026 
1027 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_ACNAME,
1028 	    sizeof(struct ngpppoe_sts), M_NOWAIT);
1029 	if (msg == NULL)
1030 		return (ENOMEM);
1031 
1032 	sts = (struct ngpppoe_sts *)msg->data;
1033 	tlen = min(NG_HOOKSIZ - 1, ntohs(tag->tag_len));
1034 	strncpy(sts->hook, tag->tag_data, tlen);
1035 	sts->hook[tlen] = '\0';
1036 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, 0);
1037 
1038 	return (error);
1039 }
1040 
1041 static int
1042 send_sessionid(sessp sp)
1043 {
1044 	int error;
1045 	struct ng_mesg *msg;
1046 
1047 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
1048 
1049 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_SESSIONID,
1050 	    sizeof(uint16_t), M_NOWAIT);
1051 	if (msg == NULL)
1052 		return (ENOMEM);
1053 
1054 	*(uint16_t *)msg->data = sp->Session_ID;
1055 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, 0);
1056 
1057 	return (error);
1058 }
1059 
1060 /*
1061  * Receive data, and do something with it.
1062  * The caller will never free m, so if we use up this data
1063  * or abort we must free it.
1064  */
1065 static int
1066 ng_pppoe_rcvdata(hook_p hook, item_p item)
1067 {
1068 	node_p			node = NG_HOOK_NODE(hook);
1069 	const priv_p		privp = NG_NODE_PRIVATE(node);
1070 	sessp			sp = NG_HOOK_PRIVATE(hook);
1071 	const struct pppoe_tag	*utag = NULL, *tag = NULL;
1072 	const struct pppoe_full_hdr *wh;
1073 	const struct pppoe_hdr	*ph;
1074 	negp			neg = NULL;
1075 	struct mbuf		*m;
1076 	hook_p 			sendhook;
1077 	int			error = 0;
1078 	uint16_t		session;
1079 	uint16_t		length;
1080 	uint8_t			code;
1081 	struct {
1082 		struct pppoe_tag hdr;
1083 		union	uniq	data;
1084 	} __packed uniqtag;
1085 
1086 	CTR6(KTR_NET, "%20s: node [%x] (%p) received %p on \"%s\" (%p)",
1087 	    __func__, node->nd_ID, node, item, hook->hk_name, hook);
1088 
1089 	NGI_GET_M(item, m);
1090 	if (NG_HOOK_PRIVATE(hook) == &privp->debug_hook) {
1091 		/*
1092 		 * Data from the debug hook gets sent without modification
1093 		 * straight to the ethernet.
1094 		 */
1095 		NG_FWD_ITEM_HOOK( error, item, privp->ethernet_hook);
1096 	 	privp->packets_out++;
1097 	} else if (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook) {
1098 		/*
1099 		 * Incoming data.
1100 		 * Dig out various fields from the packet.
1101 		 * Use them to decide where to send it.
1102 		 */
1103 
1104  		privp->packets_in++;
1105 		if( m->m_len < sizeof(*wh)) {
1106 			m = m_pullup(m, sizeof(*wh)); /* Checks length */
1107 			if (m == NULL) {
1108 				printf("couldn't m_pullup\n");
1109 				LEAVE(ENOBUFS);
1110 			}
1111 		}
1112 		wh = mtod(m, struct pppoe_full_hdr *);
1113 		length = ntohs(wh->ph.length);
1114 		switch(wh->eh.ether_type) {
1115 		case	ETHERTYPE_PPPOE_3COM_DISC: /* fall through */
1116 		case	ETHERTYPE_PPPOE_DISC:
1117 			/*
1118 			 * We need to try to make sure that the tag area
1119 			 * is contiguous, or we could wander off the end
1120 			 * of a buffer and make a mess.
1121 			 * (Linux wouldn't have this problem).
1122 			 */
1123 			if (m->m_pkthdr.len <= MHLEN) {
1124 				if( m->m_len < m->m_pkthdr.len) {
1125 					m = m_pullup(m, m->m_pkthdr.len);
1126 					if (m == NULL) {
1127 						printf("couldn't m_pullup\n");
1128 						LEAVE(ENOBUFS);
1129 					}
1130 				}
1131 			}
1132 			if (m->m_len != m->m_pkthdr.len) {
1133 				/*
1134 				 * It's not all in one piece.
1135 				 * We need to do extra work.
1136 				 * Put it into a cluster.
1137 				 */
1138 				struct mbuf *n;
1139 				n = m_dup(m, M_DONTWAIT);
1140 				m_freem(m);
1141 				m = n;
1142 				if (m) {
1143 					/* just check we got a cluster */
1144 					if (m->m_len != m->m_pkthdr.len) {
1145 						m_freem(m);
1146 						m = NULL;
1147 					}
1148 				}
1149 				if (m == NULL) {
1150 					printf("packet fragmented\n");
1151 					LEAVE(EMSGSIZE);
1152 				}
1153 			}
1154 			wh = mtod(m, struct pppoe_full_hdr *);
1155 			length = ntohs(wh->ph.length);
1156 			ph = &wh->ph;
1157 			session = ntohs(wh->ph.sid);
1158 			code = wh->ph.code;
1159 
1160 			switch(code) {
1161 			case	PADI_CODE:
1162 				/*
1163 				 * We are a server:
1164 				 * Look for a hook with the required service
1165 				 * and send the ENTIRE packet up there.
1166 				 * It should come back to a new hook in
1167 				 * PRIMED state. Look there for further
1168 				 * processing.
1169 				 */
1170 				tag = get_tag(ph, PTT_SRV_NAME);
1171 				if (tag == NULL) {
1172 					CTR1(KTR_NET,
1173 					    "%20s: PADI w/o Service-Name",
1174 					    __func__);
1175 					LEAVE(ENETUNREACH);
1176 				}
1177 
1178 				/*
1179 				 * First, try to match Service-Name
1180 				 * against our listening hooks. If
1181 				 * no success and we are in D-Link
1182 				 * compat mode and Service-Name is
1183 				 * empty, then we broadcast the PADI
1184 				 * to all listening hooks.
1185 				 */
1186 				sendhook = pppoe_match_svc(node, tag);
1187 				if (sendhook != NULL)
1188 					NG_FWD_NEW_DATA(error, item,
1189 					    sendhook, m);
1190 				else if (privp->flags & COMPAT_DLINK &&
1191 					 ntohs(tag->tag_len) == 0)
1192 					error = pppoe_broadcast_padi(node, m);
1193 				else
1194 					error = ENETUNREACH;
1195 				break;
1196 			case	PADO_CODE:
1197 				/*
1198 				 * We are a client:
1199 				 * Use the host_uniq tag to find the
1200 				 * hook this is in response to.
1201 				 * Received #2, now send #3
1202 				 * For now simply accept the first we receive.
1203 				 */
1204 				utag = get_tag(ph, PTT_HOST_UNIQ);
1205 				if ((utag == NULL)
1206 				|| (ntohs(utag->tag_len) != sizeof(sp))) {
1207 					printf("no host unique field\n");
1208 					LEAVE(ENETUNREACH);
1209 				}
1210 
1211 				sendhook = pppoe_finduniq(node, utag);
1212 				if (sendhook == NULL) {
1213 					printf("no matching session\n");
1214 					LEAVE(ENETUNREACH);
1215 				}
1216 
1217 				/*
1218 				 * Check the session is in the right state.
1219 				 * It needs to be in PPPOE_SINIT.
1220 				 */
1221 				sp = NG_HOOK_PRIVATE(sendhook);
1222 				if (sp->state != PPPOE_SINIT) {
1223 					printf("session in wrong state\n");
1224 					LEAVE(ENETUNREACH);
1225 				}
1226 				neg = sp->neg;
1227 				ng_uncallout(&neg->handle, node);
1228 
1229 				/*
1230 				 * This is the first time we hear
1231 				 * from the server, so note it's
1232 				 * unicast address, replacing the
1233 				 * broadcast address .
1234 				 */
1235 				bcopy(wh->eh.ether_shost,
1236 					neg->pkt->pkt_header.eh.ether_dhost,
1237 					ETHER_ADDR_LEN);
1238 				neg->timeout = 0;
1239 				neg->pkt->pkt_header.ph.code = PADR_CODE;
1240 				init_tags(sp);
1241 				insert_tag(sp, utag);      /* Host Unique */
1242 				if ((tag = get_tag(ph, PTT_AC_COOKIE)))
1243 					insert_tag(sp, tag); /* return cookie */
1244 				if ((tag = get_tag(ph, PTT_AC_NAME))) {
1245 					insert_tag(sp, tag); /* return it */
1246 					send_acname(sp, tag);
1247 				}
1248 				insert_tag(sp, &neg->service.hdr); /* Service */
1249 				scan_tags(sp, ph);
1250 				make_packet(sp);
1251 				sp->state = PPPOE_SREQ;
1252 				sendpacket(sp);
1253 				break;
1254 			case	PADR_CODE:
1255 
1256 				/*
1257 				 * We are a server:
1258 				 * Use the ac_cookie tag to find the
1259 				 * hook this is in response to.
1260 				 */
1261 				utag = get_tag(ph, PTT_AC_COOKIE);
1262 				if ((utag == NULL)
1263 				|| (ntohs(utag->tag_len) != sizeof(sp))) {
1264 					LEAVE(ENETUNREACH);
1265 				}
1266 
1267 				sendhook = pppoe_finduniq(node, utag);
1268 				if (sendhook == NULL) {
1269 					LEAVE(ENETUNREACH);
1270 				}
1271 
1272 				/*
1273 				 * Check the session is in the right state.
1274 				 * It needs to be in PPPOE_SOFFER
1275 				 * or PPPOE_NEWCONNECTED. If the latter,
1276 				 * then this is a retry by the client.
1277 				 * so be nice, and resend.
1278 				 */
1279 				sp = NG_HOOK_PRIVATE(sendhook);
1280 				if (sp->state == PPPOE_NEWCONNECTED) {
1281 					/*
1282 					 * Whoa! drop back to resend that
1283 					 * PADS packet.
1284 					 * We should still have a copy of it.
1285 					 */
1286 					sp->state = PPPOE_SOFFER;
1287 				}
1288 				if (sp->state != PPPOE_SOFFER) {
1289 					LEAVE (ENETUNREACH);
1290 					break;
1291 				}
1292 				neg = sp->neg;
1293 				ng_uncallout(&neg->handle, node);
1294 				neg->pkt->pkt_header.ph.code = PADS_CODE;
1295 				if (sp->Session_ID == 0)
1296 					neg->pkt->pkt_header.ph.sid =
1297 					    htons(sp->Session_ID
1298 						= get_new_sid(node));
1299 				send_sessionid(sp);
1300 				neg->timeout = 0;
1301 				/*
1302 				 * start working out the tags to respond with.
1303 				 */
1304 				init_tags(sp);
1305 				insert_tag(sp, &neg->ac_name.hdr); /* AC_NAME */
1306 				if ((tag = get_tag(ph, PTT_SRV_NAME)))
1307 					insert_tag(sp, tag);/* return service */
1308 				if ((tag = get_tag(ph, PTT_HOST_UNIQ)))
1309 					insert_tag(sp, tag); /* return it */
1310 				insert_tag(sp, utag);	/* ac_cookie */
1311 				scan_tags(sp, ph);
1312 				make_packet(sp);
1313 				sp->state = PPPOE_NEWCONNECTED;
1314 				sendpacket(sp);
1315 				/*
1316 				 * Having sent the last Negotiation header,
1317 				 * Set up the stored packet header to
1318 				 * be correct for the actual session.
1319 				 * But keep the negotialtion stuff
1320 				 * around in case we need to resend this last
1321 				 * packet. We'll discard it when we move
1322 				 * from NEWCONNECTED to CONNECTED
1323 				 */
1324 				sp->pkt_hdr = neg->pkt->pkt_header;
1325 				/* Configure ethertype depending on what
1326 				 * ethertype was used at discovery phase */
1327 				if (sp->pkt_hdr.eh.ether_type ==
1328 				    ETHERTYPE_PPPOE_3COM_DISC)
1329 					sp->pkt_hdr.eh.ether_type
1330 						= ETHERTYPE_PPPOE_3COM_SESS;
1331 				else
1332 					sp->pkt_hdr.eh.ether_type
1333 						= ETHERTYPE_PPPOE_SESS;
1334 				sp->pkt_hdr.ph.code = 0;
1335 				pppoe_send_event(sp, NGM_PPPOE_SUCCESS);
1336 				break;
1337 			case	PADS_CODE:
1338 				/*
1339 				 * We are a client:
1340 				 * Use the host_uniq tag to find the
1341 				 * hook this is in response to.
1342 				 * take the session ID and store it away.
1343 				 * Also make sure the pre-made header is
1344 				 * correct and set us into Session mode.
1345 				 */
1346 				utag = get_tag(ph, PTT_HOST_UNIQ);
1347 				if ((utag == NULL)
1348 				|| (ntohs(utag->tag_len) != sizeof(sp))) {
1349 					LEAVE (ENETUNREACH);
1350 					break;
1351 				}
1352 				sendhook = pppoe_finduniq(node, utag);
1353 				if (sendhook == NULL) {
1354 					LEAVE(ENETUNREACH);
1355 				}
1356 
1357 				/*
1358 				 * Check the session is in the right state.
1359 				 * It needs to be in PPPOE_SREQ.
1360 				 */
1361 				sp = NG_HOOK_PRIVATE(sendhook);
1362 				if (sp->state != PPPOE_SREQ) {
1363 					LEAVE(ENETUNREACH);
1364 				}
1365 				neg = sp->neg;
1366 				ng_uncallout(&neg->handle, node);
1367 				neg->pkt->pkt_header.ph.sid = wh->ph.sid;
1368 				sp->Session_ID = ntohs(wh->ph.sid);
1369 				send_sessionid(sp);
1370 				neg->timeout = 0;
1371 				sp->state = PPPOE_CONNECTED;
1372 				/*
1373 				 * Now we have gone to Connected mode,
1374 				 * Free all resources needed for
1375 				 * negotiation.
1376 				 * Keep a copy of the header we will be using.
1377 				 */
1378 				sp->pkt_hdr = neg->pkt->pkt_header;
1379 				if (privp->flags & COMPAT_3COM)
1380 					sp->pkt_hdr.eh.ether_type
1381 						= ETHERTYPE_PPPOE_3COM_SESS;
1382 				else
1383 					sp->pkt_hdr.eh.ether_type
1384 						= ETHERTYPE_PPPOE_SESS;
1385 				sp->pkt_hdr.ph.code = 0;
1386 				m_freem(neg->m);
1387 				free(sp->neg, M_NETGRAPH_PPPOE);
1388 				sp->neg = NULL;
1389 				pppoe_send_event(sp, NGM_PPPOE_SUCCESS);
1390 				break;
1391 			case	PADT_CODE:
1392 				/*
1393 				 * Send a 'close' message to the controlling
1394 				 * process (the one that set us up);
1395 				 * And then tear everything down.
1396 				 *
1397 				 * Find matching peer/session combination.
1398 				 */
1399 				sendhook = pppoe_findsession(node, wh);
1400 				if (sendhook == NULL) {
1401 					LEAVE(ENETUNREACH);
1402 				}
1403 				/* send message to creator */
1404 				/* close hook */
1405 				if (sendhook) {
1406 					ng_rmhook_self(sendhook);
1407 				}
1408 				break;
1409 			default:
1410 				LEAVE(EPFNOSUPPORT);
1411 			}
1412 			break;
1413 		case	ETHERTYPE_PPPOE_3COM_SESS:
1414 		case	ETHERTYPE_PPPOE_SESS:
1415 			/*
1416 			 * Find matching peer/session combination.
1417 			 */
1418 			sendhook = pppoe_findsession(node, wh);
1419 			if (sendhook == NULL) {
1420 				LEAVE (ENETUNREACH);
1421 				break;
1422 			}
1423 			sp = NG_HOOK_PRIVATE(sendhook);
1424 			m_adj(m, sizeof(*wh));
1425 			if (m->m_pkthdr.len < length) {
1426 				/* Packet too short, dump it */
1427 				LEAVE(EMSGSIZE);
1428 			}
1429 
1430 			/* Also need to trim excess at the end */
1431 			if (m->m_pkthdr.len > length) {
1432 				m_adj(m, -((int)(m->m_pkthdr.len - length)));
1433 			}
1434 			if ( sp->state != PPPOE_CONNECTED) {
1435 				if (sp->state == PPPOE_NEWCONNECTED) {
1436 					sp->state = PPPOE_CONNECTED;
1437 					/*
1438 					 * Now we have gone to Connected mode,
1439 					 * Free all resources needed for
1440 					 * negotiation. Be paranoid about
1441 					 * whether there may be a timeout.
1442 					 */
1443 					m_freem(sp->neg->m);
1444 					ng_uncallout(&sp->neg->handle, node);
1445 					free(sp->neg, M_NETGRAPH_PPPOE);
1446 					sp->neg = NULL;
1447 				} else {
1448 					LEAVE (ENETUNREACH);
1449 					break;
1450 				}
1451 			}
1452 			NG_FWD_NEW_DATA( error, item, sendhook, m);
1453 			break;
1454 		default:
1455 			LEAVE(EPFNOSUPPORT);
1456 		}
1457 	} else {
1458 		/*
1459 		 * Not ethernet or debug hook..
1460 		 *
1461 		 * The packet has come in on a normal hook.
1462 		 * We need to find out what kind of hook,
1463 		 * So we can decide how to handle it.
1464 		 * Check the hook's state.
1465 		 */
1466 		sp = NG_HOOK_PRIVATE(hook);
1467 		switch (sp->state) {
1468 		case	PPPOE_NEWCONNECTED:
1469 		case	PPPOE_CONNECTED: {
1470 			static const u_char addrctrl[] = { 0xff, 0x03 };
1471 			struct pppoe_full_hdr *wh;
1472 
1473 			/*
1474 			 * Remove PPP address and control fields, if any.
1475 			 * For example, ng_ppp(4) always sends LCP packets
1476 			 * with address and control fields as required by
1477 			 * generic PPP. PPPoE is an exception to the rule.
1478 			 */
1479 			if (m->m_pkthdr.len >= 2) {
1480 				if (m->m_len < 2 && !(m = m_pullup(m, 2)))
1481 					LEAVE(ENOBUFS);
1482 				if (bcmp(mtod(m, u_char *), addrctrl, 2) == 0)
1483 					m_adj(m, 2);
1484 			}
1485 			/*
1486 			 * Bang in a pre-made header, and set the length up
1487 			 * to be correct. Then send it to the ethernet driver.
1488 			 * But first correct the length.
1489 			 */
1490 			sp->pkt_hdr.ph.length = htons((short)(m->m_pkthdr.len));
1491 			M_PREPEND(m, sizeof(*wh), M_DONTWAIT);
1492 			if (m == NULL)
1493 				LEAVE(ENOBUFS);
1494 
1495 			wh = mtod(m, struct pppoe_full_hdr *);
1496 			bcopy(&sp->pkt_hdr, wh, sizeof(*wh));
1497 			NG_FWD_NEW_DATA( error, item, privp->ethernet_hook, m);
1498 			privp->packets_out++;
1499 			break;
1500 			}
1501 		case	PPPOE_PRIMED:
1502 			/*
1503 			 * A PADI packet is being returned by the application
1504 			 * that has set up this hook. This indicates that it
1505 			 * wants us to offer service.
1506 			 */
1507 			neg = sp->neg;
1508 			if (m->m_len < sizeof(*wh)) {
1509 				m = m_pullup(m, sizeof(*wh));
1510 				if (m == NULL)
1511 					LEAVE(ENOBUFS);
1512 			}
1513 			wh = mtod(m, struct pppoe_full_hdr *);
1514 			ph = &wh->ph;
1515 			session = ntohs(wh->ph.sid);
1516 			length = ntohs(wh->ph.length);
1517 			code = wh->ph.code;
1518 			/* Use peers mode in session. */
1519 			neg->pkt->pkt_header.eh.ether_type = wh->eh.ether_type;
1520 			if (code != PADI_CODE)
1521 				LEAVE(EINVAL);
1522 			ng_uncallout(&neg->handle, node);
1523 
1524 			/*
1525 			 * This is the first time we hear
1526 			 * from the client, so note it's
1527 			 * unicast address, replacing the
1528 			 * broadcast address.
1529 			 */
1530 			bcopy(wh->eh.ether_shost,
1531 				neg->pkt->pkt_header.eh.ether_dhost,
1532 				ETHER_ADDR_LEN);
1533 			sp->state = PPPOE_SOFFER;
1534 			neg->timeout = 0;
1535 			neg->pkt->pkt_header.ph.code = PADO_CODE;
1536 
1537 			/*
1538 			 * Start working out the tags to respond with.
1539 			 */
1540 			uniqtag.hdr.tag_type = PTT_AC_COOKIE;
1541 			uniqtag.hdr.tag_len = htons((u_int16_t)sizeof(sp));
1542 			uniqtag.data.pointer = sp;
1543 			init_tags(sp);
1544 			insert_tag(sp, &neg->ac_name.hdr); /* AC_NAME */
1545 			if ((tag = get_tag(ph, PTT_SRV_NAME)))
1546 				insert_tag(sp, tag);	  /* return service */
1547 			/*
1548 			 * If we have a NULL service request
1549 			 * and have an extra service defined in this hook,
1550 			 * then also add a tag for the extra service.
1551 			 * XXX this is a hack. eventually we should be able
1552 			 * to support advertising many services, not just one
1553 			 */
1554 			if (((tag == NULL) || (tag->tag_len == 0)) &&
1555 			    (neg->service.hdr.tag_len != 0)) {
1556 				insert_tag(sp, &neg->service.hdr); /* SERVICE */
1557 			}
1558 			if ((tag = get_tag(ph, PTT_HOST_UNIQ)))
1559 				insert_tag(sp, tag); /* returned hostunique */
1560 			insert_tag(sp, &uniqtag.hdr);
1561 			scan_tags(sp, ph);
1562 			make_packet(sp);
1563 			sendpacket(sp);
1564 			break;
1565 
1566 		/*
1567 		 * Packets coming from the hook make no sense
1568 		 * to sessions in these states. Throw them away.
1569 		 */
1570 		case	PPPOE_SINIT:
1571 		case	PPPOE_SREQ:
1572 		case	PPPOE_SOFFER:
1573 		case	PPPOE_SNONE:
1574 		case	PPPOE_LISTENING:
1575 		case	PPPOE_DEAD:
1576 		default:
1577 			LEAVE(ENETUNREACH);
1578 		}
1579 	}
1580 quit:
1581 	if (item)
1582 		NG_FREE_ITEM(item);
1583 	NG_FREE_M(m);
1584 	return error;
1585 }
1586 
1587 /*
1588  * Do local shutdown processing..
1589  * If we are a persistant device, we might refuse to go away, and
1590  * we'd only remove our links and reset ourself.
1591  */
1592 static int
1593 ng_pppoe_shutdown(node_p node)
1594 {
1595 	const priv_p privdata = NG_NODE_PRIVATE(node);
1596 
1597 	NG_NODE_SET_PRIVATE(node, NULL);
1598 	NG_NODE_UNREF(privdata->node);
1599 	free(privdata, M_NETGRAPH_PPPOE);
1600 	return (0);
1601 }
1602 
1603 /*
1604  * Hook disconnection
1605  *
1606  * Clean up all dangling links and information about the session/hook.
1607  * For this type, removal of the last link destroys the node.
1608  */
1609 static int
1610 ng_pppoe_disconnect(hook_p hook)
1611 {
1612 	node_p node = NG_HOOK_NODE(hook);
1613 	priv_p privp = NG_NODE_PRIVATE(node);
1614 	sessp	sp;
1615 	int 	hooks;
1616 
1617 	hooks = NG_NODE_NUMHOOKS(node); /* This one already not counted. */
1618 	if (NG_HOOK_PRIVATE(hook) == &privp->debug_hook) {
1619 		privp->debug_hook = NULL;
1620 	} else if (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook) {
1621 		privp->ethernet_hook = NULL;
1622 		if (NG_NODE_IS_VALID(node))
1623 			ng_rmnode_self(node);
1624 	} else {
1625 		sp = NG_HOOK_PRIVATE(hook);
1626 		if (sp->state != PPPOE_SNONE ) {
1627 			pppoe_send_event(sp, NGM_PPPOE_CLOSE);
1628 		}
1629 		/*
1630 		 * According to the spec, if we are connected,
1631 		 * we should send a DISC packet if we are shutting down
1632 		 * a session.
1633 		 */
1634 		if ((privp->ethernet_hook)
1635 		&& ((sp->state == PPPOE_CONNECTED)
1636 		 || (sp->state == PPPOE_NEWCONNECTED))) {
1637 			struct mbuf *m;
1638 			struct pppoe_full_hdr *wh;
1639 			struct pppoe_tag *tag;
1640 			int	msglen = strlen(SIGNOFF);
1641 			int error = 0;
1642 
1643 			/* Revert the stored header to DISC/PADT mode. */
1644 		 	wh = &sp->pkt_hdr;
1645 			wh->ph.code = PADT_CODE;
1646 			/*
1647 			 * Configure ethertype depending on what was used
1648 			 * during sessions stage.
1649 			 */
1650 			if (sp->pkt_hdr.eh.ether_type ==
1651 			    ETHERTYPE_PPPOE_3COM_SESS)
1652 				wh->eh.ether_type = ETHERTYPE_PPPOE_3COM_DISC;
1653 			else
1654 				wh->eh.ether_type = ETHERTYPE_PPPOE_DISC;
1655 
1656 			/* Generate a packet of that type. */
1657 			MGETHDR(m, M_DONTWAIT, MT_DATA);
1658 			if(m == NULL)
1659 				printf("pppoe: Session out of mbufs\n");
1660 			else {
1661 				m->m_pkthdr.rcvif = NULL;
1662 				m->m_pkthdr.len = m->m_len = sizeof(*wh);
1663 				bcopy((caddr_t)wh, mtod(m, caddr_t),
1664 				    sizeof(*wh));
1665 				/*
1666 				 * Add a General error message and adjust
1667 				 * sizes.
1668 				 */
1669 				wh = mtod(m, struct pppoe_full_hdr *);
1670 				tag = wh->ph.tag;
1671 				tag->tag_type = PTT_GEN_ERR;
1672 				tag->tag_len = htons((u_int16_t)msglen);
1673 				strncpy(tag->tag_data, SIGNOFF, msglen);
1674 				m->m_pkthdr.len = (m->m_len += sizeof(*tag) +
1675 				    msglen);
1676 				wh->ph.length = htons(sizeof(*tag) + msglen);
1677 				NG_SEND_DATA_ONLY(error,
1678 					privp->ethernet_hook, m);
1679 			}
1680 		}
1681 		/*
1682 		 * As long as we have somewhere to store the timeout handle,
1683 		 * we may have a timeout pending.. get rid of it.
1684 		 */
1685 		if (sp->neg) {
1686 			ng_uncallout(&sp->neg->handle, node);
1687 			if (sp->neg->m)
1688 				m_freem(sp->neg->m);
1689 			free(sp->neg, M_NETGRAPH_PPPOE);
1690 		}
1691 		free(sp, M_NETGRAPH_PPPOE);
1692 		NG_HOOK_SET_PRIVATE(hook, NULL);
1693 
1694 		/*
1695 		 * Work out how many session hooks there are.
1696 		 * Node goes away on last session hook removal.
1697 		 */
1698 		if (privp->ethernet_hook)
1699 			hooks -= 1;
1700 		if (privp->debug_hook)
1701 			hooks -= 1;
1702 	}
1703 	if ((NG_NODE_NUMHOOKS(node) == 0) &&
1704 	    (NG_NODE_IS_VALID(node)))
1705 		ng_rmnode_self(node);
1706 	return (0);
1707 }
1708 
1709 /*
1710  * Timeouts come here.
1711  */
1712 static void
1713 pppoe_ticker(node_p node, hook_p hook, void *arg1, int arg2)
1714 {
1715 	priv_p privp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
1716 	sessp	sp = NG_HOOK_PRIVATE(hook);
1717 	negp	neg = sp->neg;
1718 	struct mbuf *m0 = NULL;
1719 	int	error = 0;
1720 
1721 	CTR6(KTR_NET, "%20s: node [%x] (%p) hook \"%s\" (%p) session %d",
1722 	    __func__, node->nd_ID, node, hook->hk_name, hook, sp->Session_ID);
1723 	switch(sp->state) {
1724 		/*
1725 		 * Resend the last packet, using an exponential backoff.
1726 		 * After a period of time, stop growing the backoff,
1727 		 * And either leave it, or revert to the start.
1728 		 */
1729 	case	PPPOE_SINIT:
1730 	case	PPPOE_SREQ:
1731 		/* Timeouts on these produce resends. */
1732 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1733 		NG_SEND_DATA_ONLY( error, privp->ethernet_hook, m0);
1734 		ng_callout(&neg->handle, node, hook, neg->timeout * hz,
1735 		    pppoe_ticker, NULL, 0);
1736 		if ((neg->timeout <<= 1) > PPPOE_TIMEOUT_LIMIT) {
1737 			if (sp->state == PPPOE_SREQ) {
1738 				/* Revert to SINIT mode. */
1739 				pppoe_start(sp);
1740 			} else {
1741 				neg->timeout = PPPOE_TIMEOUT_LIMIT;
1742 			}
1743 		}
1744 		break;
1745 	case	PPPOE_PRIMED:
1746 	case	PPPOE_SOFFER:
1747 		/* A timeout on these says "give up" */
1748 		ng_rmhook_self(hook);
1749 		break;
1750 	default:
1751 		/* Timeouts have no meaning in other states. */
1752 		printf("pppoe: unexpected timeout\n");
1753 	}
1754 }
1755 
1756 
1757 static void
1758 sendpacket(sessp sp)
1759 {
1760 	struct	mbuf *m0 = NULL;
1761 	hook_p	hook = sp->hook;
1762 	node_p	node = NG_HOOK_NODE(hook);
1763 	priv_p	privp = NG_NODE_PRIVATE(node);
1764 	negp	neg = sp->neg;
1765 	int	error = 0;
1766 
1767 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
1768 	switch(sp->state) {
1769 	case	PPPOE_LISTENING:
1770 	case	PPPOE_DEAD:
1771 	case	PPPOE_SNONE:
1772 	case	PPPOE_CONNECTED:
1773 		printf("pppoe: sendpacket: unexpected state\n");
1774 		break;
1775 
1776 	case	PPPOE_NEWCONNECTED:
1777 		/* Send the PADS without a timeout - we're now connected. */
1778 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1779 		NG_SEND_DATA_ONLY( error, privp->ethernet_hook, m0);
1780 		break;
1781 
1782 	case	PPPOE_PRIMED:
1783 		/* No packet to send, but set up the timeout. */
1784 		ng_callout(&neg->handle, node, hook, PPPOE_OFFER_TIMEOUT * hz,
1785 		    pppoe_ticker, NULL, 0);
1786 		break;
1787 
1788 	case	PPPOE_SOFFER:
1789 		/*
1790 		 * Send the offer but if they don't respond
1791 		 * in PPPOE_OFFER_TIMEOUT seconds, forget about it.
1792 		 */
1793 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1794 		NG_SEND_DATA_ONLY( error, privp->ethernet_hook, m0);
1795 		ng_callout(&neg->handle, node, hook, PPPOE_OFFER_TIMEOUT * hz,
1796 		    pppoe_ticker, NULL, 0);
1797 		break;
1798 
1799 	case	PPPOE_SINIT:
1800 	case	PPPOE_SREQ:
1801 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1802 		NG_SEND_DATA_ONLY( error, privp->ethernet_hook, m0);
1803 		ng_callout(&neg->handle, node, hook, PPPOE_INITIAL_TIMEOUT * hz,
1804 		    pppoe_ticker, NULL, 0);
1805 		neg->timeout = PPPOE_INITIAL_TIMEOUT * 2;
1806 		break;
1807 
1808 	default:
1809 		error = EINVAL;
1810 		printf("pppoe: timeout: bad state\n");
1811 	}
1812 }
1813 
1814 /*
1815  * Parse an incoming packet to see if any tags should be copied to the
1816  * output packet. Don't do any tags that have been handled in the main
1817  * state machine.
1818  */
1819 static const struct pppoe_tag*
1820 scan_tags(sessp	sp, const struct pppoe_hdr* ph)
1821 {
1822 	const char *const end = (const char *)next_tag(ph);
1823 	const char *ptn;
1824 	const struct pppoe_tag *pt = &ph->tag[0];
1825 
1826 	/*
1827 	 * Keep processing tags while a tag header will still fit.
1828 	 */
1829 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
1830 
1831 	while((const char*)(pt + 1) <= end) {
1832 		/*
1833 		 * If the tag data would go past the end of the packet, abort.
1834 		 */
1835 		ptn = (((const char *)(pt + 1)) + ntohs(pt->tag_len));
1836 		if(ptn > end)
1837 			return NULL;
1838 
1839 		switch (pt->tag_type) {
1840 		case	PTT_RELAY_SID:
1841 			insert_tag(sp, pt);
1842 			break;
1843 		case	PTT_EOL:
1844 			return NULL;
1845 		case	PTT_SRV_NAME:
1846 		case	PTT_AC_NAME:
1847 		case	PTT_HOST_UNIQ:
1848 		case	PTT_AC_COOKIE:
1849 		case	PTT_VENDOR:
1850 		case	PTT_SRV_ERR:
1851 		case	PTT_SYS_ERR:
1852 		case	PTT_GEN_ERR:
1853 			break;
1854 		}
1855 		pt = (const struct pppoe_tag*)ptn;
1856 	}
1857 	return NULL;
1858 }
1859 
1860 static	int
1861 pppoe_send_event(sessp sp, enum cmd cmdid)
1862 {
1863 	int error;
1864 	struct ng_mesg *msg;
1865 	struct ngpppoe_sts *sts;
1866 
1867 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
1868 
1869 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, cmdid,
1870 			sizeof(struct ngpppoe_sts), M_NOWAIT);
1871 	if (msg == NULL)
1872 		return (ENOMEM);
1873 	sts = (struct ngpppoe_sts *)msg->data;
1874 	strncpy(sts->hook, NG_HOOK_NAME(sp->hook), NG_HOOKSIZ);
1875 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, 0);
1876 	return (error);
1877 }
1878