xref: /freebsd/sys/netgraph/ng_pppoe.c (revision 0a36787e4c1fa0cf77dcf83be0867178476e372b)
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/epoch.h>
52 #include <sys/syslog.h>
53 #include <net/ethernet.h>
54 
55 #include <netgraph/ng_message.h>
56 #include <netgraph/netgraph.h>
57 #include <netgraph/ng_parse.h>
58 #include <netgraph/ng_pppoe.h>
59 #include <netgraph/ng_ether.h>
60 
61 #ifdef NG_SEPARATE_MALLOC
62 static MALLOC_DEFINE(M_NETGRAPH_PPPOE, "netgraph_pppoe", "netgraph pppoe node");
63 #else
64 #define M_NETGRAPH_PPPOE M_NETGRAPH
65 #endif
66 
67 #define SIGNOFF "session closed"
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 	{
173 	  NGM_PPPOE_COOKIE,
174 	  NGM_PPPOE_SETMAXP,
175 	  "setmaxp",
176 	  &ng_parse_uint16_type,
177 	  NULL
178 	},
179         {
180 	  NGM_PPPOE_COOKIE,
181 	  NGM_PPPOE_SEND_HURL,
182 	  "send_hurl",
183 	  &ngpppoe_init_data_state_type,
184 	  NULL
185         },
186         {
187 	  NGM_PPPOE_COOKIE,
188 	  NGM_PPPOE_SEND_MOTM,
189 	  "send_motm",
190 	  &ngpppoe_init_data_state_type,
191 	  NULL
192         },
193 	{ 0 }
194 };
195 
196 /* Netgraph node type descriptor */
197 static struct ng_type typestruct = {
198 	.version =	NG_ABI_VERSION,
199 	.name =		NG_PPPOE_NODE_TYPE,
200 	.constructor =	ng_pppoe_constructor,
201 	.rcvmsg =	ng_pppoe_rcvmsg,
202 	.shutdown =	ng_pppoe_shutdown,
203 	.newhook =	ng_pppoe_newhook,
204 	.connect =	ng_pppoe_connect,
205 	.rcvdata =	ng_pppoe_rcvdata,
206 	.disconnect =	ng_pppoe_disconnect,
207 	.cmdlist =	ng_pppoe_cmds,
208 };
209 NETGRAPH_INIT(pppoe, &typestruct);
210 
211 /*
212  * States for the session state machine.
213  * These have no meaning if there is no hook attached yet.
214  */
215 enum state {
216     PPPOE_SNONE=0,	/* [both] Initial state */
217     PPPOE_LISTENING,	/* [Daemon] Listening for discover initiation pkt */
218     PPPOE_SINIT,	/* [Client] Sent discovery initiation */
219     PPPOE_PRIMED,	/* [Server] Awaiting PADI from daemon */
220     PPPOE_SOFFER,	/* [Server] Sent offer message  (got PADI)*/
221     PPPOE_SREQ,		/* [Client] Sent a Request */
222     PPPOE_NEWCONNECTED,	/* [Server] Connection established, No data received */
223     PPPOE_CONNECTED,	/* [Both] Connection established, Data received */
224     PPPOE_DEAD		/* [Both] */
225 };
226 
227 #define NUMTAGS 20 /* number of tags we are set up to work with */
228 
229 /*
230  * Information we store for each hook on each node for negotiating the
231  * session. The mbuf and cluster are freed once negotiation has completed.
232  * The whole negotiation block is then discarded.
233  */
234 
235 struct sess_neg {
236 	struct mbuf 		*m; /* holds cluster with last sent packet */
237 	union	packet		*pkt; /* points within the above cluster */
238 	struct callout		handle;   /* see timeout(9) */
239 	u_int			timeout; /* 0,1,2,4,8,16 etc. seconds */
240 	u_int			numtags;
241 	const struct pppoe_tag	*tags[NUMTAGS];
242 	u_int			service_len;
243 	u_int			ac_name_len;
244 	u_int			host_uniq_len;
245 
246 	struct datatag		service;
247 	struct datatag		ac_name;
248 	struct datatag		host_uniq;
249 };
250 typedef struct sess_neg *negp;
251 
252 /*
253  * Session information that is needed after connection.
254  */
255 struct sess_con {
256 	hook_p  		hook;
257 	uint16_t		Session_ID;
258 	enum state		state;
259 	ng_ID_t			creator;	/* who to notify */
260 	struct pppoe_full_hdr	pkt_hdr;	/* used when connected */
261 	negp			neg;		/* used when negotiating */
262 	LIST_ENTRY(sess_con)	sessions;
263 };
264 typedef struct sess_con *sessp;
265 
266 #define SESSHASHSIZE	0x0100
267 #define SESSHASH(x)	(((x) ^ ((x) >> 8)) & (SESSHASHSIZE - 1))
268 
269 struct sess_hash_entry {
270 	struct mtx	mtx;
271 	LIST_HEAD(hhead, sess_con) head;
272 };
273 
274 /*
275  * Information we store for each node
276  */
277 struct PPPoE {
278 	node_p		node;		/* back pointer to node */
279 	hook_p  	ethernet_hook;
280 	hook_p  	debug_hook;
281 	u_int   	packets_in;	/* packets in from ethernet */
282 	u_int   	packets_out;	/* packets out towards ethernet */
283 	uint32_t	flags;
284 #define	COMPAT_3COM	0x00000001
285 #define	COMPAT_DLINK	0x00000002
286 	struct ether_header	eh;
287 	LIST_HEAD(, sess_con) listeners;
288 	struct sess_hash_entry	sesshash[SESSHASHSIZE];
289 	struct maxptag	max_payload;	/* PPP-Max-Payload (RFC4638) */
290 };
291 typedef struct PPPoE *priv_p;
292 
293 union uniq {
294 	char bytes[sizeof(void *)];
295 	void *pointer;
296 };
297 
298 #define	LEAVE(x) do { error = x; goto quit; } while(0)
299 static void	pppoe_start(sessp sp);
300 static void	pppoe_ticker(node_p node, hook_p hook, void *arg1, int arg2);
301 static const	struct pppoe_tag *scan_tags(sessp sp,
302 			const struct pppoe_hdr* ph);
303 static	int	pppoe_send_event(sessp sp, enum cmd cmdid);
304 
305 /*************************************************************************
306  * Some basic utilities  from the Linux version with author's permission.*
307  * Author:	Michal Ostrowski <mostrows@styx.uwaterloo.ca>		 *
308  ************************************************************************/
309 
310 /*
311  * Return the location where the next tag can be put
312  */
313 static __inline const struct pppoe_tag*
314 next_tag(const struct pppoe_hdr* ph)
315 {
316 	return (const struct pppoe_tag*)(((const char*)(ph + 1))
317 	    + ntohs(ph->length));
318 }
319 
320 /*
321  * Look for a tag of a specific type.
322  * Don't trust any length the other end says,
323  * but assume we already sanity checked ph->length.
324  */
325 static const struct pppoe_tag*
326 get_tag(const struct pppoe_hdr* ph, uint16_t idx)
327 {
328 	const char *const end = (const char *)next_tag(ph);
329 	const struct pppoe_tag *pt = (const void *)(ph + 1);
330 	const char *ptn;
331 
332 	/*
333 	 * Keep processing tags while a tag header will still fit.
334 	 */
335 	while((const char*)(pt + 1) <= end) {
336 		/*
337 		 * If the tag data would go past the end of the packet, abort.
338 		 */
339 		ptn = (((const char *)(pt + 1)) + ntohs(pt->tag_len));
340 		if (ptn > end) {
341 			CTR2(KTR_NET, "%20s: invalid length for tag %d",
342 			    __func__, idx);
343 			return (NULL);
344 		}
345 		if (pt->tag_type == idx) {
346 			CTR2(KTR_NET, "%20s: found tag %d", __func__, idx);
347 			return (pt);
348 		}
349 
350 		pt = (const struct pppoe_tag*)ptn;
351 	}
352 
353 	CTR2(KTR_NET, "%20s: not found tag %d", __func__, idx);
354 	return (NULL);
355 }
356 
357 /**************************************************************************
358  * Inlines to initialise or add tags to a session's tag list.
359  **************************************************************************/
360 /*
361  * Initialise the session's tag list.
362  */
363 static void
364 init_tags(sessp sp)
365 {
366 	KASSERT(sp->neg != NULL, ("%s: no neg", __func__));
367 	sp->neg->numtags = 0;
368 }
369 
370 static void
371 insert_tag(sessp sp, const struct pppoe_tag *tp)
372 {
373 	negp neg = sp->neg;
374 	int i;
375 
376 	KASSERT(neg != NULL, ("%s: no neg", __func__));
377 	if ((i = neg->numtags++) < NUMTAGS) {
378 		neg->tags[i] = tp;
379 	} else {
380 		log(LOG_NOTICE, "ng_pppoe: asked to add too many tags to "
381 		    "packet\n");
382 		neg->numtags--;
383 	}
384 }
385 
386 /*
387  * Make up a packet, using the tags filled out for the session.
388  *
389  * Assume that the actual pppoe header and ethernet header
390  * are filled out externally to this routine.
391  * Also assume that neg->wh points to the correct
392  * location at the front of the buffer space.
393  */
394 static void
395 make_packet(sessp sp) {
396 	struct pppoe_full_hdr *wh = &sp->neg->pkt->pkt_header;
397 	const struct pppoe_tag **tag;
398 	char *dp;
399 	int count;
400 	int tlen;
401 	uint16_t length = 0;
402 
403 	KASSERT((sp->neg != NULL) && (sp->neg->m != NULL),
404 	    ("%s: called from wrong state", __func__));
405 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
406 
407 	dp = (char *)(&wh->ph + 1);
408 	for (count = 0, tag = sp->neg->tags;
409 	    ((count < sp->neg->numtags) && (count < NUMTAGS));
410 	    tag++, count++) {
411 		tlen = ntohs((*tag)->tag_len) + sizeof(**tag);
412 		if ((length + tlen) > (ETHER_MAX_LEN - 4 - sizeof(*wh))) {
413 			log(LOG_NOTICE, "ng_pppoe: tags too long\n");
414 			sp->neg->numtags = count;
415 			break;	/* XXX chop off what's too long */
416 		}
417 		bcopy(*tag, (char *)dp, tlen);
418 		length += tlen;
419 		dp += tlen;
420 	}
421  	wh->ph.length = htons(length);
422 	sp->neg->m->m_len = length + sizeof(*wh);
423 	sp->neg->m->m_pkthdr.len = length + sizeof(*wh);
424 }
425 
426 /**************************************************************************
427  * Routines to match a service.						  *
428  **************************************************************************/
429 
430 /*
431  * Find a hook that has a service string that matches that
432  * we are seeking. For now use a simple string.
433  * In the future we may need something like regexp().
434  *
435  * Null string is a wildcard (ANY service), according to RFC2516.
436  * And historical FreeBSD wildcard is also "*".
437  */
438 
439 static hook_p
440 pppoe_match_svc(node_p node, const struct pppoe_tag *tag)
441 {
442 	const priv_p privp = NG_NODE_PRIVATE(node);
443 	sessp sp;
444 
445 	LIST_FOREACH(sp, &privp->listeners, sessions) {
446 		negp neg = sp->neg;
447 
448 		/* Empty Service-Name matches any service. */
449 		if (neg->service_len == 0)
450 			break;
451 
452 		/* Special case for a blank or "*" service name (wildcard). */
453 		if (neg->service_len == 1 && neg->service.data[0] == '*')
454 			break;
455 
456 		/* If the lengths don't match, that aint it. */
457 		if (neg->service_len != ntohs(tag->tag_len))
458 			continue;
459 
460 		if (strncmp((const char *)(tag + 1), neg->service.data,
461 		    ntohs(tag->tag_len)) == 0)
462 			break;
463 	}
464 	CTR3(KTR_NET, "%20s: matched %p for %s", __func__,
465 	    sp?sp->hook:NULL, (const char *)(tag + 1));
466 
467 	return (sp?sp->hook:NULL);
468 }
469 
470 /*
471  * Broadcast the PADI packet in m0 to all listening hooks.
472  * This routine is called when a PADI with empty Service-Name
473  * tag is received. Client should receive PADOs with all
474  * available services.
475  */
476 static int
477 pppoe_broadcast_padi(node_p node, struct mbuf *m0)
478 {
479 	const priv_p privp = NG_NODE_PRIVATE(node);
480 	sessp sp;
481 	int error = 0;
482 
483 	LIST_FOREACH(sp, &privp->listeners, sessions) {
484 		struct mbuf *m;
485 
486 		m = m_dup(m0, M_NOWAIT);
487 		if (m == NULL)
488 			return (ENOMEM);
489 		NG_SEND_DATA_ONLY(error, sp->hook, m);
490 		if (error)
491 			return (error);
492 	}
493 
494 	return (0);
495 }
496 
497 /*
498  * Find a hook, which name equals to given service.
499  */
500 static hook_p
501 pppoe_find_svc(node_p node, const char *svc_name, int svc_len)
502 {
503 	const priv_p privp = NG_NODE_PRIVATE(node);
504 	sessp sp;
505 
506 	LIST_FOREACH(sp, &privp->listeners, sessions) {
507 		negp neg = sp->neg;
508 
509 		if (neg->service_len == svc_len &&
510 		    strncmp(svc_name, neg->service.data, svc_len) == 0)
511 			return (sp->hook);
512 	}
513 
514 	return (NULL);
515 }
516 
517 /**************************************************************************
518  * Routines to find a particular session that matches an incoming packet. *
519  **************************************************************************/
520 /* Find free session and add to hash. */
521 static uint16_t
522 pppoe_getnewsession(sessp sp)
523 {
524 	const priv_p privp = NG_NODE_PRIVATE(NG_HOOK_NODE(sp->hook));
525 	static uint16_t pppoe_sid = 1;
526 	sessp	tsp;
527 	uint16_t val, hash;
528 
529 restart:
530 	/* Atomicity is not needed here as value will be checked. */
531 	val = pppoe_sid++;
532 	/* Spec says 0xFFFF is reserved, also don't use 0x0000. */
533 	if (val == 0xffff || val == 0x0000)
534 		val = pppoe_sid = 1;
535 
536 	/* Check it isn't already in use. */
537 	hash = SESSHASH(val);
538 	mtx_lock(&privp->sesshash[hash].mtx);
539 	LIST_FOREACH(tsp, &privp->sesshash[hash].head, sessions) {
540 		if (tsp->Session_ID == val)
541 			break;
542 	}
543 	if (!tsp) {
544 		sp->Session_ID = val;
545 		LIST_INSERT_HEAD(&privp->sesshash[hash].head, sp, sessions);
546 	}
547 	mtx_unlock(&privp->sesshash[hash].mtx);
548 	if (tsp)
549 		goto restart;
550 
551 	CTR2(KTR_NET, "%20s: new sid %d", __func__, val);
552 
553 	return (val);
554 }
555 
556 /* Add specified session to hash. */
557 static void
558 pppoe_addsession(sessp sp)
559 {
560 	const priv_p	privp = NG_NODE_PRIVATE(NG_HOOK_NODE(sp->hook));
561 	uint16_t	hash = SESSHASH(sp->Session_ID);
562 
563 	mtx_lock(&privp->sesshash[hash].mtx);
564 	LIST_INSERT_HEAD(&privp->sesshash[hash].head, sp, sessions);
565 	mtx_unlock(&privp->sesshash[hash].mtx);
566 }
567 
568 /* Delete specified session from hash. */
569 static void
570 pppoe_delsession(sessp sp)
571 {
572 	const priv_p	privp = NG_NODE_PRIVATE(NG_HOOK_NODE(sp->hook));
573 	uint16_t	hash = SESSHASH(sp->Session_ID);
574 
575 	mtx_lock(&privp->sesshash[hash].mtx);
576 	LIST_REMOVE(sp, sessions);
577 	mtx_unlock(&privp->sesshash[hash].mtx);
578 }
579 
580 /* Find matching peer/session combination. */
581 static sessp
582 pppoe_findsession(priv_p privp, const struct pppoe_full_hdr *wh)
583 {
584 	uint16_t 	session = ntohs(wh->ph.sid);
585 	uint16_t	hash = SESSHASH(session);
586 	sessp		sp = NULL;
587 
588 	mtx_lock(&privp->sesshash[hash].mtx);
589 	LIST_FOREACH(sp, &privp->sesshash[hash].head, sessions) {
590 		if (sp->Session_ID == session &&
591 		    bcmp(sp->pkt_hdr.eh.ether_dhost,
592 		     wh->eh.ether_shost, ETHER_ADDR_LEN) == 0) {
593 			break;
594 		}
595 	}
596 	mtx_unlock(&privp->sesshash[hash].mtx);
597 	CTR3(KTR_NET, "%20s: matched %p for %d", __func__, sp?sp->hook:NULL,
598 	    session);
599 
600 	return (sp);
601 }
602 
603 static hook_p
604 pppoe_finduniq(node_p node, const struct pppoe_tag *tag)
605 {
606 	hook_p	hook = NULL;
607 	sessp	sp;
608 
609 	/* Cycle through all known hooks. */
610 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
611 		/* Skip any nonsession hook. */
612 		if (NG_HOOK_PRIVATE(hook) == NULL)
613 			continue;
614 		sp = NG_HOOK_PRIVATE(hook);
615 		/* Skip already connected sessions. */
616 		if (sp->neg == NULL)
617 			continue;
618 		if (sp->neg->host_uniq_len == ntohs(tag->tag_len) &&
619 		    bcmp(sp->neg->host_uniq.data, (const char *)(tag + 1),
620 		     sp->neg->host_uniq_len) == 0)
621 			break;
622 	}
623 	CTR3(KTR_NET, "%20s: matched %p for %p", __func__, hook, sp);
624 
625 	return (hook);
626 }
627 
628 static hook_p
629 pppoe_findcookie(node_p node, const struct pppoe_tag *tag)
630 {
631 	hook_p	hook = NULL;
632 	union uniq cookie;
633 
634 	bcopy(tag + 1, cookie.bytes, sizeof(void *));
635 	/* Cycle through all known hooks. */
636 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
637 		/* Skip any nonsession hook. */
638 		if (NG_HOOK_PRIVATE(hook) == NULL)
639 			continue;
640 		if (cookie.pointer == NG_HOOK_PRIVATE(hook))
641 			break;
642 	}
643 	CTR3(KTR_NET, "%20s: matched %p for %p", __func__, hook, cookie.pointer);
644 
645 	return (hook);
646 }
647 
648 /**************************************************************************
649  * Start of Netgraph entrypoints.					  *
650  **************************************************************************/
651 
652 /*
653  * Allocate the private data structure and link it with node.
654  */
655 static int
656 ng_pppoe_constructor(node_p node)
657 {
658 	priv_p	privp;
659 	int	i;
660 
661 	/* Initialize private descriptor. */
662 	privp = malloc(sizeof(*privp), M_NETGRAPH_PPPOE, M_WAITOK | M_ZERO);
663 
664 	/* Link structs together; this counts as our one reference to *node. */
665 	NG_NODE_SET_PRIVATE(node, privp);
666 	privp->node = node;
667 
668 	/* Initialize to standard mode. */
669 	memset(&privp->eh.ether_dhost, 0xff, ETHER_ADDR_LEN);
670 	privp->eh.ether_type = ETHERTYPE_PPPOE_DISC;
671 
672 	LIST_INIT(&privp->listeners);
673 	for (i = 0; i < SESSHASHSIZE; i++) {
674 	    mtx_init(&privp->sesshash[i].mtx, "PPPoE hash mutex", NULL, MTX_DEF);
675 	    LIST_INIT(&privp->sesshash[i].head);
676 	}
677 
678 	CTR3(KTR_NET, "%20s: created node [%x] (%p)",
679 	    __func__, node->nd_ID, node);
680 
681 	return (0);
682 }
683 
684 /*
685  * Give our ok for a hook to be added...
686  * point the hook's private info to the hook structure.
687  *
688  * The following hook names are special:
689  *  "ethernet":  the hook that should be connected to a NIC.
690  *  "debug":	copies of data sent out here  (when I write the code).
691  * All other hook names need only be unique. (the framework checks this).
692  */
693 static int
694 ng_pppoe_newhook(node_p node, hook_p hook, const char *name)
695 {
696 	const priv_p privp = NG_NODE_PRIVATE(node);
697 	sessp sp;
698 
699 	if (strcmp(name, NG_PPPOE_HOOK_ETHERNET) == 0) {
700 		privp->ethernet_hook = hook;
701 		NG_HOOK_SET_RCVDATA(hook, ng_pppoe_rcvdata_ether);
702 	} else if (strcmp(name, NG_PPPOE_HOOK_DEBUG) == 0) {
703 		privp->debug_hook = hook;
704 		NG_HOOK_SET_RCVDATA(hook, ng_pppoe_rcvdata_debug);
705 	} else {
706 		/*
707 		 * Any other unique name is OK.
708 		 * The infrastructure has already checked that it's unique,
709 		 * so just allocate it and hook it in.
710 		 */
711 		sp = malloc(sizeof(*sp), M_NETGRAPH_PPPOE, M_NOWAIT | M_ZERO);
712 		if (sp == NULL)
713 			return (ENOMEM);
714 
715 		NG_HOOK_SET_PRIVATE(hook, sp);
716 		sp->hook = hook;
717 	}
718 	CTR5(KTR_NET, "%20s: node [%x] (%p) connected hook %s (%p)",
719 	    __func__, node->nd_ID, node, name, hook);
720 
721 	return(0);
722 }
723 
724 /*
725  * Hook has been added successfully. Request the MAC address of
726  * the underlying Ethernet node.
727  */
728 static int
729 ng_pppoe_connect(hook_p hook)
730 {
731 	const priv_p privp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
732 	struct ng_mesg *msg;
733 	int error;
734 
735 	if (hook != privp->ethernet_hook)
736 		return (0);
737 
738 	/*
739 	 * If this is Ethernet hook, then request MAC address
740 	 * from our downstream.
741 	 */
742 	NG_MKMESSAGE(msg, NGM_ETHER_COOKIE, NGM_ETHER_GET_ENADDR, 0, M_NOWAIT);
743 	if (msg == NULL)
744 		return (ENOBUFS);
745 
746 	/*
747 	 * Our hook and peer hook have HK_INVALID flag set,
748 	 * so we can't use NG_SEND_MSG_HOOK() macro here.
749 	 */
750 	NG_SEND_MSG_ID(error, privp->node, msg,
751 	    NG_NODE_ID(NG_PEER_NODE(privp->ethernet_hook)),
752 	    NG_NODE_ID(privp->node));
753 
754 	return (error);
755 }
756 /*
757  * Get a netgraph control message.
758  * Check it is one we understand. If needed, send a response.
759  * We sometimes save the address for an async action later.
760  * Always free the message.
761  */
762 static int
763 ng_pppoe_rcvmsg(node_p node, item_p item, hook_p lasthook)
764 {
765 	struct epoch_tracker et;
766 	priv_p privp = NG_NODE_PRIVATE(node);
767 	struct ngpppoe_init_data *ourmsg = NULL;
768 	struct ng_mesg *resp = NULL;
769 	int error = 0;
770 	hook_p hook = NULL;
771 	sessp sp = NULL;
772 	negp neg = NULL;
773 	struct ng_mesg *msg;
774 
775 	NGI_GET_MSG(item, msg);
776 	CTR5(KTR_NET, "%20s: node [%x] (%p) got message %d with cookie %d",
777 	    __func__, node->nd_ID, node, msg->header.cmd,
778 	    msg->header.typecookie);
779 
780 	/* Deal with message according to cookie and command. */
781 	switch (msg->header.typecookie) {
782 	case NGM_PPPOE_COOKIE:
783 		switch (msg->header.cmd) {
784 		case NGM_PPPOE_CONNECT:
785 		case NGM_PPPOE_LISTEN:
786 		case NGM_PPPOE_OFFER:
787 		case NGM_PPPOE_SERVICE:
788 		case NGM_PPPOE_SEND_HURL:
789 		case NGM_PPPOE_SEND_MOTM:
790 			ourmsg = (struct ngpppoe_init_data *)msg->data;
791 			if (msg->header.arglen < sizeof(*ourmsg)) {
792 				log(LOG_ERR, "ng_pppoe[%x]: init data too "
793 				    "small\n", node->nd_ID);
794 				LEAVE(EMSGSIZE);
795 			}
796 			if (msg->header.cmd == NGM_PPPOE_SEND_HURL ||
797 			    msg->header.cmd == NGM_PPPOE_SEND_MOTM) {
798 				if (msg->header.arglen - sizeof(*ourmsg) >
799 				    PPPOE_PADM_VALUE_SIZE) {
800 					log(LOG_ERR, "ng_pppoe[%x]: message "
801 					    "too big\n", node->nd_ID);
802 					LEAVE(EMSGSIZE);
803 				}
804 			} else {
805 				if (msg->header.arglen - sizeof(*ourmsg) >
806 				    PPPOE_SERVICE_NAME_SIZE) {
807 					log(LOG_ERR, "ng_pppoe[%x]: service name "
808 					    "too big\n", node->nd_ID);
809 					LEAVE(EMSGSIZE);
810 				}
811 			}
812 			if (msg->header.arglen - sizeof(*ourmsg) <
813 			    ourmsg->data_len) {
814 				log(LOG_ERR, "ng_pppoe[%x]: init data has bad "
815 				    "length, %d should be %zd\n", node->nd_ID,
816 				    ourmsg->data_len,
817 				    msg->header.arglen - sizeof (*ourmsg));
818 				LEAVE(EMSGSIZE);
819 			}
820 
821 			/* Make sure strcmp will terminate safely. */
822 			ourmsg->hook[sizeof(ourmsg->hook) - 1] = '\0';
823 
824 			/* Find hook by name. */
825 			hook = ng_findhook(node, ourmsg->hook);
826 			if (hook == NULL)
827 				LEAVE(ENOENT);
828 
829 			sp = NG_HOOK_PRIVATE(hook);
830 			if (sp == NULL)
831 				LEAVE(EINVAL);
832 
833 			if (msg->header.cmd == NGM_PPPOE_LISTEN) {
834 				/*
835 				 * Ensure we aren't already listening for this
836 				 * service.
837 				 */
838 				if (pppoe_find_svc(node, ourmsg->data,
839 				    ourmsg->data_len) != NULL)
840 					LEAVE(EEXIST);
841 			}
842 
843 			/*
844 			 * PPPOE_SERVICE advertisements are set up
845 			 * on sessions that are in PRIMED state.
846 			 */
847 			if (msg->header.cmd == NGM_PPPOE_SERVICE)
848 				break;
849 
850 			/*
851 			 * PADM messages are set up on active sessions.
852 			 */
853 			if (msg->header.cmd == NGM_PPPOE_SEND_HURL ||
854 			    msg->header.cmd == NGM_PPPOE_SEND_MOTM) {
855 				if (sp->state != PPPOE_NEWCONNECTED &&
856 				    sp->state != PPPOE_CONNECTED) {
857 					log(LOG_NOTICE, "ng_pppoe[%x]: session is not "
858 					    "active\n", node->nd_ID);
859 					LEAVE(EISCONN);
860 				}
861 				break;
862 			}
863 
864 			if (sp->state != PPPOE_SNONE) {
865 				log(LOG_NOTICE, "ng_pppoe[%x]: Session already "
866 				    "active\n", node->nd_ID);
867 				LEAVE(EISCONN);
868 			}
869 
870 			/*
871 			 * Set up prototype header.
872 			 */
873 			neg = malloc(sizeof(*neg), M_NETGRAPH_PPPOE,
874 			    M_NOWAIT | M_ZERO);
875 
876 			if (neg == NULL)
877 				LEAVE(ENOMEM);
878 
879 			neg->m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
880 			if (neg->m == NULL) {
881 				free(neg, M_NETGRAPH_PPPOE);
882 				LEAVE(ENOBUFS);
883 			}
884 			neg->m->m_pkthdr.rcvif = NULL;
885 			sp->neg = neg;
886 			ng_callout_init(&neg->handle);
887 			neg->m->m_len = sizeof(struct pppoe_full_hdr);
888 			neg->pkt = mtod(neg->m, union packet*);
889 			memcpy((void *)&neg->pkt->pkt_header.eh,
890 			    &privp->eh, sizeof(struct ether_header));
891 			neg->pkt->pkt_header.ph.ver = 0x1;
892 			neg->pkt->pkt_header.ph.type = 0x1;
893 			neg->pkt->pkt_header.ph.sid = 0x0000;
894 			neg->timeout = 0;
895 
896 			sp->creator = NGI_RETADDR(item);
897 		}
898 		switch (msg->header.cmd) {
899 		case NGM_PPPOE_GET_STATUS:
900 		    {
901 			struct ngpppoestat *stats;
902 
903 			NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT);
904 			if (!resp)
905 				LEAVE(ENOMEM);
906 
907 			stats = (struct ngpppoestat *) resp->data;
908 			stats->packets_in = privp->packets_in;
909 			stats->packets_out = privp->packets_out;
910 			break;
911 		    }
912 		case NGM_PPPOE_CONNECT:
913 		    {
914 			/*
915 			 * Check the hook exists and is Uninitialised.
916 			 * Send a PADI request, and start the timeout logic.
917 			 * Store the originator of this message so we can send
918 			 * a success or fail message to them later.
919 			 * Move the session to SINIT.
920 			 * Set up the session to the correct state and
921 			 * start it.
922 			 */
923 			int	acnpos, acnlen = 0, acnsep = 0;
924 			int	hupos, hulen = 0, husep = 0;
925 			int	i, srvpos, srvlen;
926 			acnpos = 0;
927 			for (i = 0; i < ourmsg->data_len; i++) {
928 				if (ourmsg->data[i] == '\\') {
929 					acnlen = i;
930 					acnsep = 1;
931 					break;
932 				}
933 			}
934 			hupos = acnlen + acnsep;
935 			for (i = hupos; i < ourmsg->data_len; i++) {
936 				if (ourmsg->data[i] == '|') {
937 					hulen = i - hupos;
938 					husep = 1;
939 					break;
940 				}
941 			}
942 			srvpos = hupos + hulen + husep;
943 			srvlen = ourmsg->data_len - srvpos;
944 
945 			bcopy(ourmsg->data + acnpos, neg->ac_name.data, acnlen);
946 			neg->ac_name_len = acnlen;
947 
948 			neg->host_uniq.hdr.tag_type = PTT_HOST_UNIQ;
949 			if (hulen == 0) {
950 				/* Not provided, generate one */
951 				neg->host_uniq.hdr.tag_len = htons(sizeof(sp));
952 				bcopy(&sp, neg->host_uniq.data, sizeof(sp));
953 				neg->host_uniq_len = sizeof(sp);
954 			} else if (hulen > 2 && ourmsg->data[hupos] == '0' &&
955 			  ourmsg->data[hupos + 1] == 'x' && hulen % 2 == 0) {
956 				/* Hex encoded */
957 				static const char hexdig[16] = "0123456789abcdef";
958 				int j;
959 
960 				neg->host_uniq.hdr.tag_len = htons((uint16_t)(hulen / 2 - 1));
961 				for (i = 0; i < hulen - 2; i++) {
962 					for (j = 0;
963 					     j < 16 &&
964 					     ourmsg->data[hupos + 2 + i] != hexdig[j];
965 					     j++);
966 					if (j == 16)
967 						LEAVE(EINVAL);
968 					if (i % 2 == 0)
969 						neg->host_uniq.data[i / 2] = j << 4;
970 					else
971 						neg->host_uniq.data[i / 2] |= j;
972 				}
973 				neg->host_uniq_len = hulen / 2 - 1;
974 			} else {
975 				/* Plain string */
976 				neg->host_uniq.hdr.tag_len = htons((uint16_t)hulen);
977 				bcopy(ourmsg->data + hupos, neg->host_uniq.data, hulen);
978 				neg->host_uniq_len = hulen;
979 			}
980 
981 			neg->service.hdr.tag_type = PTT_SRV_NAME;
982 			neg->service.hdr.tag_len = htons((uint16_t)srvlen);
983 			bcopy(ourmsg->data + srvpos, neg->service.data, srvlen);
984 			neg->service_len = srvlen;
985 			NET_EPOCH_ENTER(et);
986 			pppoe_start(sp);
987 			NET_EPOCH_EXIT(et);
988 			break;
989 		    }
990 		case NGM_PPPOE_LISTEN:
991 			/*
992 			 * Check the hook exists and is Uninitialised.
993 			 * Install the service matching string.
994 			 * Store the originator of this message so we can send
995 			 * a success or fail message to them later.
996 			 * Move the hook to 'LISTENING'
997 			 */
998 			neg->service.hdr.tag_type = PTT_SRV_NAME;
999 			neg->service.hdr.tag_len =
1000 			    htons((uint16_t)ourmsg->data_len);
1001 
1002 			if (ourmsg->data_len)
1003 				bcopy(ourmsg->data, neg->service.data,
1004 				    ourmsg->data_len);
1005 			neg->service_len = ourmsg->data_len;
1006 			neg->pkt->pkt_header.ph.code = PADT_CODE;
1007 			/*
1008 			 * Wait for PADI packet coming from Ethernet.
1009 			 */
1010 			sp->state = PPPOE_LISTENING;
1011 			LIST_INSERT_HEAD(&privp->listeners, sp, sessions);
1012 			break;
1013 		case NGM_PPPOE_OFFER:
1014 			/*
1015 			 * Check the hook exists and is Uninitialised.
1016 			 * Store the originator of this message so we can send
1017 			 * a success of fail message to them later.
1018 			 * Store the AC-Name given and go to PRIMED.
1019 			 */
1020 			neg->ac_name.hdr.tag_type = PTT_AC_NAME;
1021 			neg->ac_name.hdr.tag_len =
1022 			    htons((uint16_t)ourmsg->data_len);
1023 			if (ourmsg->data_len)
1024 				bcopy(ourmsg->data, neg->ac_name.data,
1025 				    ourmsg->data_len);
1026 			neg->ac_name_len = ourmsg->data_len;
1027 			neg->pkt->pkt_header.ph.code = PADO_CODE;
1028 			/*
1029 			 * Wait for PADI packet coming from hook.
1030 			 */
1031 			sp->state = PPPOE_PRIMED;
1032 			break;
1033 		case NGM_PPPOE_SERVICE:
1034 			/*
1035 			 * Check the session is primed.
1036 			 * for now just allow ONE service to be advertised.
1037 			 * If you do it twice you just overwrite.
1038 			 */
1039 			if (sp->state != PPPOE_PRIMED) {
1040 				log(LOG_NOTICE, "ng_pppoe[%x]: session not "
1041 				    "primed\n", node->nd_ID);
1042 				LEAVE(EISCONN);
1043 			}
1044 			neg = sp->neg;
1045 			neg->service.hdr.tag_type = PTT_SRV_NAME;
1046 			neg->service.hdr.tag_len =
1047 			    htons((uint16_t)ourmsg->data_len);
1048 
1049 			if (ourmsg->data_len)
1050 				bcopy(ourmsg->data, neg->service.data,
1051 				    ourmsg->data_len);
1052 			neg->service_len = ourmsg->data_len;
1053 			break;
1054 		case NGM_PPPOE_SETMODE:
1055 		    {
1056 			char *s;
1057 			size_t len;
1058 
1059 			if (msg->header.arglen == 0)
1060 				LEAVE(EINVAL);
1061 
1062 			s = (char *)msg->data;
1063 			len = msg->header.arglen - 1;
1064 
1065 			/* Search for matching mode string. */
1066 			if (len == strlen(NG_PPPOE_STANDARD) &&
1067 			    (strncmp(NG_PPPOE_STANDARD, s, len) == 0)) {
1068 				privp->flags = 0;
1069 				privp->eh.ether_type = ETHERTYPE_PPPOE_DISC;
1070 				break;
1071 			}
1072 			if (len == strlen(NG_PPPOE_3COM) &&
1073 			    (strncmp(NG_PPPOE_3COM, s, len) == 0)) {
1074 				privp->flags |= COMPAT_3COM;
1075 				privp->eh.ether_type =
1076 				    ETHERTYPE_PPPOE_3COM_DISC;
1077 				break;
1078 			}
1079 			if (len == strlen(NG_PPPOE_DLINK) &&
1080 			    (strncmp(NG_PPPOE_DLINK, s, len) == 0)) {
1081 				privp->flags |= COMPAT_DLINK;
1082 				break;
1083 			}
1084 			error = EINVAL;
1085 			break;
1086 		    }
1087 		case NGM_PPPOE_GETMODE:
1088 		    {
1089 			char *s;
1090 			size_t len = 0;
1091 
1092 			if (privp->flags == 0)
1093 				len += strlen(NG_PPPOE_STANDARD) + 1;
1094 			if (privp->flags & COMPAT_3COM)
1095 				len += strlen(NG_PPPOE_3COM) + 1;
1096 			if (privp->flags & COMPAT_DLINK)
1097 				len += strlen(NG_PPPOE_DLINK) + 1;
1098 
1099 			NG_MKRESPONSE(resp, msg, len, M_NOWAIT);
1100 			if (resp == NULL)
1101 				LEAVE(ENOMEM);
1102 
1103 			s = (char *)resp->data;
1104 			if (privp->flags == 0) {
1105 				len = strlen(NG_PPPOE_STANDARD);
1106 				strlcpy(s, NG_PPPOE_STANDARD, len + 1);
1107 				break;
1108 			}
1109 			if (privp->flags & COMPAT_3COM) {
1110 				len = strlen(NG_PPPOE_3COM);
1111 				strlcpy(s, NG_PPPOE_3COM, len + 1);
1112 				s += len;
1113 			}
1114 			if (privp->flags & COMPAT_DLINK) {
1115 				if (s != resp->data)
1116 					*s++ = '|';
1117 				len = strlen(NG_PPPOE_DLINK);
1118 				strlcpy(s, NG_PPPOE_DLINK, len + 1);
1119 			}
1120 			break;
1121 		    }
1122 		case NGM_PPPOE_SETENADDR:
1123 			if (msg->header.arglen != ETHER_ADDR_LEN)
1124 				LEAVE(EINVAL);
1125 			bcopy(msg->data, &privp->eh.ether_shost,
1126 			    ETHER_ADDR_LEN);
1127 			break;
1128 		case NGM_PPPOE_SETMAXP:
1129 			if (msg->header.arglen != sizeof(uint16_t))
1130 				LEAVE(EINVAL);
1131 			privp->max_payload.hdr.tag_type = PTT_MAX_PAYL;
1132 			privp->max_payload.hdr.tag_len = htons(sizeof(uint16_t));
1133 			privp->max_payload.data = htons(*((uint16_t *)msg->data));
1134 			break;
1135 		case NGM_PPPOE_SEND_HURL:
1136 		    {
1137 			struct mbuf *m;
1138 
1139 			/* Generate a packet of that type. */
1140 			m = m_gethdr(M_NOWAIT, MT_DATA);
1141 			if (m == NULL)
1142 				log(LOG_NOTICE, "ng_pppoe[%x]: session out of "
1143 				    "mbufs\n", node->nd_ID);
1144 			else {
1145 				struct pppoe_full_hdr *wh;
1146 				struct pppoe_tag *tag;
1147 				int     error = 0;
1148 
1149 				wh = mtod(m, struct pppoe_full_hdr *);
1150 				bcopy(&sp->pkt_hdr, wh, sizeof(*wh));
1151 
1152 				/* Revert the stored header to DISC/PADM mode. */
1153 				wh->ph.code = PADM_CODE;
1154 				/*
1155 				 * Configure ethertype depending on what
1156 				 * was used during sessions stage.
1157 				 */
1158 				if (wh->eh.ether_type ==
1159 				    ETHERTYPE_PPPOE_3COM_SESS)
1160 					wh->eh.ether_type = ETHERTYPE_PPPOE_3COM_DISC;
1161 				else
1162 					wh->eh.ether_type = ETHERTYPE_PPPOE_DISC;
1163 				/*
1164 				 * Add PADM message and adjust sizes.
1165 				 */
1166 				tag = (void *)(&wh->ph + 1);
1167 				tag->tag_type = PTT_HURL;
1168 				tag->tag_len = htons(ourmsg->data_len);
1169 				strncpy((char *)(tag + 1), ourmsg->data, ourmsg->data_len);
1170 				m->m_pkthdr.len = m->m_len = sizeof(*wh) + sizeof(*tag) +
1171 				    ourmsg->data_len;
1172 				wh->ph.length = htons(sizeof(*tag) + ourmsg->data_len);
1173 				NET_EPOCH_ENTER(et);
1174 				NG_SEND_DATA_ONLY(error,
1175 				    privp->ethernet_hook, m);
1176 				NET_EPOCH_EXIT(et);
1177 			}
1178 			break;
1179 		    }
1180 		case NGM_PPPOE_SEND_MOTM:
1181 		    {
1182 			struct mbuf *m;
1183 
1184 			/* Generate a packet of that type. */
1185 			m = m_gethdr(M_NOWAIT, MT_DATA);
1186 			if (m == NULL)
1187 				log(LOG_NOTICE, "ng_pppoe[%x]: session out of "
1188 				    "mbufs\n", node->nd_ID);
1189 			else {
1190 				struct pppoe_full_hdr *wh;
1191 				struct pppoe_tag *tag;
1192 				int     error = 0;
1193 
1194 				wh = mtod(m, struct pppoe_full_hdr *);
1195 				bcopy(&sp->pkt_hdr, wh, sizeof(*wh));
1196 
1197 				/* Revert the stored header to DISC/PADM mode. */
1198 				wh->ph.code = PADM_CODE;
1199 				/*
1200 				 * Configure ethertype depending on what
1201 				 * was used during sessions stage.
1202 				 */
1203 				if (wh->eh.ether_type ==
1204 				    ETHERTYPE_PPPOE_3COM_SESS)
1205 					wh->eh.ether_type = ETHERTYPE_PPPOE_3COM_DISC;
1206 				else
1207 					wh->eh.ether_type = ETHERTYPE_PPPOE_DISC;
1208 				/*
1209 				 * Add PADM message and adjust sizes.
1210 				 */
1211 				tag = (void *)(&wh->ph + 1);
1212 				tag->tag_type = PTT_MOTM;
1213 				tag->tag_len = htons(ourmsg->data_len);
1214 				strncpy((char *)(tag + 1), ourmsg->data, ourmsg->data_len);
1215 				m->m_pkthdr.len = m->m_len = sizeof(*wh) + sizeof(*tag) +
1216 				    ourmsg->data_len;
1217 				wh->ph.length = htons(sizeof(*tag) + ourmsg->data_len);
1218 				NET_EPOCH_ENTER(et);
1219 				NG_SEND_DATA_ONLY(error,
1220 				    privp->ethernet_hook, m);
1221 				NET_EPOCH_EXIT(et);
1222 			}
1223 			break;
1224 		    }
1225 		default:
1226 			LEAVE(EINVAL);
1227 		}
1228 		break;
1229 	case NGM_ETHER_COOKIE:
1230 		if (!(msg->header.flags & NGF_RESP))
1231 			LEAVE(EINVAL);
1232 		switch (msg->header.cmd) {
1233 		case NGM_ETHER_GET_ENADDR:
1234 			if (msg->header.arglen != ETHER_ADDR_LEN)
1235 				LEAVE(EINVAL);
1236 			bcopy(msg->data, &privp->eh.ether_shost,
1237 			    ETHER_ADDR_LEN);
1238 			break;
1239 		default:
1240 			LEAVE(EINVAL);
1241 		}
1242 		break;
1243 	default:
1244 		LEAVE(EINVAL);
1245 	}
1246 
1247 	/* Take care of synchronous response, if any. */
1248 quit:
1249 	CTR2(KTR_NET, "%20s: returning %d", __func__, error);
1250 	NG_RESPOND_MSG(error, node, item, resp);
1251 	/* Free the message and return. */
1252 	NG_FREE_MSG(msg);
1253 	return(error);
1254 }
1255 
1256 /*
1257  * Start a client into the first state. A separate function because
1258  * it can be needed if the negotiation times out.
1259  */
1260 static void
1261 pppoe_start(sessp sp)
1262 {
1263 	hook_p	hook = sp->hook;
1264 	node_p	node = NG_HOOK_NODE(hook);
1265 	priv_p	privp = NG_NODE_PRIVATE(node);
1266 	negp	neg = sp->neg;
1267 	struct  mbuf *m0;
1268 	int	error;
1269 
1270 	/*
1271 	 * Kick the state machine into starting up.
1272 	 */
1273 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
1274 	sp->state = PPPOE_SINIT;
1275 	/*
1276 	 * Reset the packet header to broadcast. Since we are
1277 	 * in a client mode use configured ethertype.
1278 	 */
1279 	memcpy((void *)&neg->pkt->pkt_header.eh, &privp->eh,
1280 	    sizeof(struct ether_header));
1281 	neg->pkt->pkt_header.ph.code = PADI_CODE;
1282 	init_tags(sp);
1283 	insert_tag(sp, &neg->host_uniq.hdr);
1284 	insert_tag(sp, &neg->service.hdr);
1285 	if (privp->max_payload.data != 0)
1286 		insert_tag(sp, &privp->max_payload.hdr);
1287 	make_packet(sp);
1288 	/*
1289 	 * Send packet and prepare to retransmit it after timeout.
1290 	 */
1291 	ng_callout(&neg->handle, node, hook, PPPOE_INITIAL_TIMEOUT * hz,
1292 	    pppoe_ticker, NULL, 0);
1293 	neg->timeout = PPPOE_INITIAL_TIMEOUT * 2;
1294 	m0 = m_copypacket(neg->m, M_NOWAIT);
1295 	NG_SEND_DATA_ONLY(error, privp->ethernet_hook, m0);
1296 }
1297 
1298 static int
1299 send_acname(sessp sp, const struct pppoe_tag *tag)
1300 {
1301 	int error, tlen;
1302 	struct ng_mesg *msg;
1303 	struct ngpppoe_sts *sts;
1304 
1305 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
1306 
1307 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_ACNAME,
1308 	    sizeof(struct ngpppoe_sts), M_NOWAIT);
1309 	if (msg == NULL)
1310 		return (ENOMEM);
1311 
1312 	sts = (struct ngpppoe_sts *)msg->data;
1313 	tlen = min(NG_HOOKSIZ - 1, ntohs(tag->tag_len));
1314 	strncpy(sts->hook, (const char *)(tag + 1), tlen);
1315 	sts->hook[tlen] = '\0';
1316 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, 0);
1317 
1318 	return (error);
1319 }
1320 
1321 static int
1322 send_sessionid(sessp sp)
1323 {
1324 	int error;
1325 	struct ng_mesg *msg;
1326 
1327 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
1328 
1329 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_SESSIONID,
1330 	    sizeof(uint16_t), M_NOWAIT);
1331 	if (msg == NULL)
1332 		return (ENOMEM);
1333 
1334 	*(uint16_t *)msg->data = sp->Session_ID;
1335 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, 0);
1336 
1337 	return (error);
1338 }
1339 
1340 static int
1341 send_maxp(sessp sp, const struct pppoe_tag *tag)
1342 {
1343 	int error;
1344 	struct ng_mesg *msg;
1345 	struct ngpppoe_maxp *maxp;
1346 
1347 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
1348 
1349 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_SETMAXP,
1350 	    sizeof(struct ngpppoe_maxp), M_NOWAIT);
1351 	if (msg == NULL)
1352 		return (ENOMEM);
1353 
1354 	maxp = (struct ngpppoe_maxp *)msg->data;
1355 	strncpy(maxp->hook, NG_HOOK_NAME(sp->hook), NG_HOOKSIZ);
1356 	maxp->data = ntohs(((const struct maxptag *)tag)->data);
1357 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, 0);
1358 
1359 	return (error);
1360 }
1361 
1362 static int
1363 send_hurl(sessp sp, const struct pppoe_tag *tag)
1364 {
1365 	int error, tlen;
1366 	struct ng_mesg *msg;
1367 	struct ngpppoe_padm *padm;
1368 
1369 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
1370 
1371 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_HURL,
1372 	    sizeof(struct ngpppoe_padm), M_NOWAIT);
1373 	if (msg == NULL)
1374 		return (ENOMEM);
1375 
1376 	padm = (struct ngpppoe_padm *)msg->data;
1377 	tlen = min(PPPOE_PADM_VALUE_SIZE - 1, ntohs(tag->tag_len));
1378 	strncpy(padm->msg, (const char *)(tag + 1), tlen);
1379 	padm->msg[tlen] = '\0';
1380 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, 0);
1381 
1382 	return (error);
1383 }
1384 
1385 static int
1386 send_motm(sessp sp, const struct pppoe_tag *tag)
1387 {
1388 	int error, tlen;
1389 	struct ng_mesg *msg;
1390 	struct ngpppoe_padm *padm;
1391 
1392 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
1393 
1394 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_MOTM,
1395 	    sizeof(struct ngpppoe_padm), M_NOWAIT);
1396 	if (msg == NULL)
1397 		return (ENOMEM);
1398 
1399 	padm = (struct ngpppoe_padm *)msg->data;
1400 	tlen = min(PPPOE_PADM_VALUE_SIZE - 1, ntohs(tag->tag_len));
1401 	strncpy(padm->msg, (const char *)(tag + 1), tlen);
1402 	padm->msg[tlen] = '\0';
1403 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, 0);
1404 
1405 	return (error);
1406 }
1407 
1408 /*
1409  * Receive data from session hook and do something with it.
1410  */
1411 static int
1412 ng_pppoe_rcvdata(hook_p hook, item_p item)
1413 {
1414 	node_p			node = NG_HOOK_NODE(hook);
1415 	const priv_p		privp = NG_NODE_PRIVATE(node);
1416 	sessp			sp = NG_HOOK_PRIVATE(hook);
1417 	struct pppoe_full_hdr	*wh;
1418 	struct mbuf		*m;
1419 	int			error;
1420 
1421 	CTR6(KTR_NET, "%20s: node [%x] (%p) received %p on \"%s\" (%p)",
1422 	    __func__, node->nd_ID, node, item, hook->hk_name, hook);
1423 
1424 	NGI_GET_M(item, m);
1425 	switch (sp->state) {
1426 	case	PPPOE_NEWCONNECTED:
1427 	case	PPPOE_CONNECTED: {
1428 		/*
1429 		 * Remove PPP address and control fields, if any.
1430 		 * For example, ng_ppp(4) always sends LCP packets
1431 		 * with address and control fields as required by
1432 		 * generic PPP. PPPoE is an exception to the rule.
1433 		 */
1434 		if (m->m_pkthdr.len >= 2) {
1435 			if (m->m_len < 2 && !(m = m_pullup(m, 2)))
1436 				LEAVE(ENOBUFS);
1437 			if (mtod(m, u_char *)[0] == 0xff &&
1438 			    mtod(m, u_char *)[1] == 0x03)
1439 				m_adj(m, 2);
1440 		}
1441 		/*
1442 		 * Bang in a pre-made header, and set the length up
1443 		 * to be correct. Then send it to the ethernet driver.
1444 		 */
1445 		M_PREPEND(m, sizeof(*wh), M_NOWAIT);
1446 		if (m == NULL)
1447 			LEAVE(ENOBUFS);
1448 
1449 		wh = mtod(m, struct pppoe_full_hdr *);
1450 		bcopy(&sp->pkt_hdr, wh, sizeof(*wh));
1451 		wh->ph.length = htons(m->m_pkthdr.len - sizeof(*wh));
1452 		NG_FWD_NEW_DATA(error, item, privp->ethernet_hook, m);
1453 		privp->packets_out++;
1454 		break;
1455 		}
1456 	case	PPPOE_PRIMED: {
1457 		struct {
1458 			struct pppoe_tag hdr;
1459 			union	uniq	data;
1460 		} __packed 	uniqtag;
1461 		const struct pppoe_tag	*tag;
1462 		struct mbuf 	*m0;
1463 		const struct pppoe_hdr	*ph;
1464 		negp		neg = sp->neg;
1465 	        uint16_t	session;
1466 		uint16_t	length;
1467 		uint8_t		code;
1468 
1469 		/*
1470 		 * A PADI packet is being returned by the application
1471 		 * that has set up this hook. This indicates that it
1472 		 * wants us to offer service.
1473 		 */
1474 		if (m->m_len < sizeof(*wh)) {
1475 			m = m_pullup(m, sizeof(*wh));
1476 			if (m == NULL)
1477 				LEAVE(ENOBUFS);
1478 		}
1479 		wh = mtod(m, struct pppoe_full_hdr *);
1480 		ph = &wh->ph;
1481 		session = ntohs(wh->ph.sid);
1482 		length = ntohs(wh->ph.length);
1483 		code = wh->ph.code;
1484 		/* Use peers mode in session. */
1485 		neg->pkt->pkt_header.eh.ether_type = wh->eh.ether_type;
1486 		if (code != PADI_CODE)
1487 			LEAVE(EINVAL);
1488 		ng_uncallout(&neg->handle, node);
1489 
1490 		/*
1491 		 * This is the first time we hear
1492 		 * from the client, so note it's
1493 		 * unicast address, replacing the
1494 		 * broadcast address.
1495 		 */
1496 		bcopy(wh->eh.ether_shost,
1497 			neg->pkt->pkt_header.eh.ether_dhost,
1498 			ETHER_ADDR_LEN);
1499 		sp->state = PPPOE_SOFFER;
1500 		neg->timeout = 0;
1501 		neg->pkt->pkt_header.ph.code = PADO_CODE;
1502 
1503 		/*
1504 		 * Start working out the tags to respond with.
1505 		 */
1506 		uniqtag.hdr.tag_type = PTT_AC_COOKIE;
1507 		uniqtag.hdr.tag_len = htons((u_int16_t)sizeof(sp));
1508 		uniqtag.data.pointer = sp;
1509 		init_tags(sp);
1510 		insert_tag(sp, &neg->ac_name.hdr); /* AC_NAME */
1511 		if ((tag = get_tag(ph, PTT_SRV_NAME)))
1512 			insert_tag(sp, tag);	  /* return service */
1513 		/*
1514 		 * If we have a NULL service request
1515 		 * and have an extra service defined in this hook,
1516 		 * then also add a tag for the extra service.
1517 		 * XXX this is a hack. eventually we should be able
1518 		 * to support advertising many services, not just one
1519 		 */
1520 		if (((tag == NULL) || (tag->tag_len == 0)) &&
1521 		    (neg->service.hdr.tag_len != 0)) {
1522 			insert_tag(sp, &neg->service.hdr); /* SERVICE */
1523 		}
1524 		if ((tag = get_tag(ph, PTT_HOST_UNIQ)))
1525 			insert_tag(sp, tag); /* returned hostunique */
1526 		insert_tag(sp, &uniqtag.hdr);
1527 		scan_tags(sp, ph);
1528 		make_packet(sp);
1529 		/*
1530 		 * Send the offer but if they don't respond
1531 		 * in PPPOE_OFFER_TIMEOUT seconds, forget about it.
1532 		 */
1533 		ng_callout(&neg->handle, node, hook, PPPOE_OFFER_TIMEOUT * hz,
1534 		    pppoe_ticker, NULL, 0);
1535 		m0 = m_copypacket(sp->neg->m, M_NOWAIT);
1536 		NG_FWD_NEW_DATA(error, item, privp->ethernet_hook, m0);
1537 		privp->packets_out++;
1538 		break;
1539 		}
1540 
1541 	/*
1542 	 * Packets coming from the hook make no sense
1543 	 * to sessions in the rest of states. Throw them away.
1544 	 */
1545 	default:
1546 		LEAVE(ENETUNREACH);
1547 	}
1548 quit:
1549 	if (item)
1550 		NG_FREE_ITEM(item);
1551 	NG_FREE_M(m);
1552 	return (error);
1553 }
1554 
1555 /*
1556  * Receive data from ether and do something with it.
1557  */
1558 static int
1559 ng_pppoe_rcvdata_ether(hook_p hook, item_p item)
1560 {
1561 	node_p			node = NG_HOOK_NODE(hook);
1562 	const priv_p		privp = NG_NODE_PRIVATE(node);
1563 	sessp			sp;
1564 	const struct pppoe_tag	*utag = NULL, *tag = NULL;
1565 	const struct pppoe_tag	sntag = { PTT_SRV_NAME, 0 };
1566 	const struct pppoe_full_hdr *wh;
1567 	const struct pppoe_hdr	*ph;
1568 	negp			neg = NULL;
1569 	struct mbuf		*m;
1570 	hook_p 			sendhook;
1571 	int			error = 0;
1572 	uint16_t		session;
1573 	uint16_t		length;
1574 	uint8_t			code;
1575 	struct	mbuf 		*m0;
1576 
1577 	CTR6(KTR_NET, "%20s: node [%x] (%p) received %p on \"%s\" (%p)",
1578 	    __func__, node->nd_ID, node, item, hook->hk_name, hook);
1579 
1580 	NGI_GET_M(item, m);
1581 	/*
1582 	 * Dig out various fields from the packet.
1583 	 * Use them to decide where to send it.
1584 	 */
1585 	privp->packets_in++;
1586 	if( m->m_len < sizeof(*wh)) {
1587 		m = m_pullup(m, sizeof(*wh)); /* Checks length */
1588 		if (m == NULL) {
1589 			log(LOG_NOTICE, "ng_pppoe[%x]: couldn't "
1590 			    "m_pullup(wh)\n", node->nd_ID);
1591 			LEAVE(ENOBUFS);
1592 		}
1593 	}
1594 	wh = mtod(m, struct pppoe_full_hdr *);
1595 	length = ntohs(wh->ph.length);
1596 	switch(wh->eh.ether_type) {
1597 	case	ETHERTYPE_PPPOE_3COM_DISC: /* fall through */
1598 	case	ETHERTYPE_PPPOE_DISC:
1599 		/*
1600 		 * We need to try to make sure that the tag area
1601 		 * is contiguous, or we could wander off the end
1602 		 * of a buffer and make a mess.
1603 		 * (Linux wouldn't have this problem).
1604 		 */
1605 		if (m->m_pkthdr.len <= MHLEN) {
1606 			if( m->m_len < m->m_pkthdr.len) {
1607 				m = m_pullup(m, m->m_pkthdr.len);
1608 				if (m == NULL) {
1609 					log(LOG_NOTICE, "ng_pppoe[%x]: "
1610 					    "couldn't m_pullup(pkthdr)\n",
1611 					    node->nd_ID);
1612 					LEAVE(ENOBUFS);
1613 				}
1614 			}
1615 		}
1616 		if (m->m_len != m->m_pkthdr.len) {
1617 			/*
1618 			 * It's not all in one piece.
1619 			 * We need to do extra work.
1620 			 * Put it into a cluster.
1621 			 */
1622 			struct mbuf *n;
1623 			n = m_dup(m, M_NOWAIT);
1624 			m_freem(m);
1625 			m = n;
1626 			if (m) {
1627 				/* just check we got a cluster */
1628 				if (m->m_len != m->m_pkthdr.len) {
1629 					m_freem(m);
1630 					m = NULL;
1631 				}
1632 			}
1633 			if (m == NULL) {
1634 				log(LOG_NOTICE, "ng_pppoe[%x]: packet "
1635 				    "fragmented\n", node->nd_ID);
1636 				LEAVE(EMSGSIZE);
1637 			}
1638 		}
1639 		wh = mtod(m, struct pppoe_full_hdr *);
1640 		length = ntohs(wh->ph.length);
1641 		ph = &wh->ph;
1642 		session = ntohs(wh->ph.sid);
1643 		code = wh->ph.code;
1644 
1645 		switch(code) {
1646 		case	PADI_CODE:
1647 			/*
1648 			 * We are a server:
1649 			 * Look for a hook with the required service and send
1650 			 * the ENTIRE packet up there. It should come back to
1651 			 * a new hook in PRIMED state. Look there for further
1652 			 * processing.
1653 			 */
1654 			tag = get_tag(ph, PTT_SRV_NAME);
1655 			if (tag == NULL)
1656 				tag = &sntag;
1657 
1658 			/*
1659 			 * First, try to match Service-Name against our
1660 			 * listening hooks. If no success and we are in D-Link
1661 			 * compat mode and Service-Name is empty, then we
1662 			 * broadcast the PADI to all listening hooks.
1663 			 */
1664 			sendhook = pppoe_match_svc(node, tag);
1665 			if (sendhook != NULL)
1666 				NG_FWD_NEW_DATA(error, item, sendhook, m);
1667 			else if (privp->flags & COMPAT_DLINK &&
1668 				 ntohs(tag->tag_len) == 0)
1669 				error = pppoe_broadcast_padi(node, m);
1670 			else
1671 				error = ENETUNREACH;
1672 			break;
1673 		case	PADO_CODE:
1674 			/*
1675 			 * We are a client:
1676 			 * Use the host_uniq tag to find the hook this is in
1677 			 * response to. Received #2, now send #3
1678 			 * For now simply accept the first we receive.
1679 			 */
1680 			utag = get_tag(ph, PTT_HOST_UNIQ);
1681 			if (utag == NULL) {
1682 				log(LOG_NOTICE, "ng_pppoe[%x]: no host "
1683 				    "unique field\n", node->nd_ID);
1684 				LEAVE(ENETUNREACH);
1685 			}
1686 
1687 			sendhook = pppoe_finduniq(node, utag);
1688 			if (sendhook == NULL) {
1689 				log(LOG_NOTICE, "ng_pppoe[%x]: no "
1690 				    "matching session\n", node->nd_ID);
1691 				LEAVE(ENETUNREACH);
1692 			}
1693 
1694 			/*
1695 			 * Check the session is in the right state.
1696 			 * It needs to be in PPPOE_SINIT.
1697 			 */
1698 			sp = NG_HOOK_PRIVATE(sendhook);
1699 			if (sp->state == PPPOE_SREQ ||
1700 			    sp->state == PPPOE_CONNECTED) {
1701 				break;	/* Multiple PADO is OK. */
1702 			}
1703 			if (sp->state != PPPOE_SINIT) {
1704 				log(LOG_NOTICE, "ng_pppoe[%x]: session "
1705 				    "in wrong state\n", node->nd_ID);
1706 				LEAVE(ENETUNREACH);
1707 			}
1708 			neg = sp->neg;
1709 			/* If requested specific AC-name, check it. */
1710 			if (neg->ac_name_len) {
1711 				tag = get_tag(ph, PTT_AC_NAME);
1712 				if (!tag) {
1713 					/* No PTT_AC_NAME in PADO */
1714 					break;
1715 				}
1716 				if (neg->ac_name_len != htons(tag->tag_len) ||
1717 				    strncmp(neg->ac_name.data,
1718 				    (const char *)(tag + 1),
1719 				    neg->ac_name_len) != 0) {
1720 					break;
1721 				}
1722 			}
1723 			sp->state = PPPOE_SREQ;
1724 			ng_uncallout(&neg->handle, node);
1725 
1726 			/*
1727 			 * This is the first time we hear
1728 			 * from the server, so note it's
1729 			 * unicast address, replacing the
1730 			 * broadcast address .
1731 			 */
1732 			bcopy(wh->eh.ether_shost,
1733 				neg->pkt->pkt_header.eh.ether_dhost,
1734 				ETHER_ADDR_LEN);
1735 			neg->timeout = 0;
1736 			neg->pkt->pkt_header.ph.code = PADR_CODE;
1737 			init_tags(sp);
1738 			insert_tag(sp, utag);      	/* Host Unique */
1739 			if ((tag = get_tag(ph, PTT_AC_COOKIE)))
1740 				insert_tag(sp, tag); 	/* return cookie */
1741 			if ((tag = get_tag(ph, PTT_AC_NAME))) {
1742 				insert_tag(sp, tag); 	/* return it */
1743 				send_acname(sp, tag);
1744 			}
1745 			if ((tag = get_tag(ph, PTT_MAX_PAYL)) &&
1746 			    (privp->max_payload.data != 0))
1747 				insert_tag(sp, tag);	/* return it */
1748 			insert_tag(sp, &neg->service.hdr); /* Service */
1749 			scan_tags(sp, ph);
1750 			make_packet(sp);
1751 			sp->state = PPPOE_SREQ;
1752 			ng_callout(&neg->handle, node, sp->hook,
1753 			    PPPOE_INITIAL_TIMEOUT * hz,
1754 			    pppoe_ticker, NULL, 0);
1755 			neg->timeout = PPPOE_INITIAL_TIMEOUT * 2;
1756 			m0 = m_copypacket(neg->m, M_NOWAIT);
1757 			NG_FWD_NEW_DATA(error, item, privp->ethernet_hook, m0);
1758 			break;
1759 		case	PADR_CODE:
1760 			/*
1761 			 * We are a server:
1762 			 * Use the ac_cookie tag to find the
1763 			 * hook this is in response to.
1764 			 */
1765 			utag = get_tag(ph, PTT_AC_COOKIE);
1766 			if ((utag == NULL) ||
1767 			    (ntohs(utag->tag_len) != sizeof(sp))) {
1768 				LEAVE(ENETUNREACH);
1769 			}
1770 
1771 			sendhook = pppoe_findcookie(node, utag);
1772 			if (sendhook == NULL)
1773 				LEAVE(ENETUNREACH);
1774 
1775 			/*
1776 			 * Check the session is in the right state.
1777 			 * It needs to be in PPPOE_SOFFER or PPPOE_NEWCONNECTED.
1778 			 * If the latter, then this is a retry by the client,
1779 			 * so be nice, and resend.
1780 			 */
1781 			sp = NG_HOOK_PRIVATE(sendhook);
1782 			if (sp->state == PPPOE_NEWCONNECTED) {
1783 				/*
1784 				 * Whoa! drop back to resend that PADS packet.
1785 				 * We should still have a copy of it.
1786 				 */
1787 				sp->state = PPPOE_SOFFER;
1788 			} else if (sp->state != PPPOE_SOFFER)
1789 				LEAVE (ENETUNREACH);
1790 			neg = sp->neg;
1791 			ng_uncallout(&neg->handle, node);
1792 			neg->pkt->pkt_header.ph.code = PADS_CODE;
1793 			if (sp->Session_ID == 0) {
1794 				neg->pkt->pkt_header.ph.sid =
1795 				    htons(pppoe_getnewsession(sp));
1796 			}
1797 			send_sessionid(sp);
1798 			neg->timeout = 0;
1799 			/*
1800 			 * start working out the tags to respond with.
1801 			 */
1802 			init_tags(sp);
1803 			insert_tag(sp, &neg->ac_name.hdr); /* AC_NAME */
1804 			if ((tag = get_tag(ph, PTT_SRV_NAME)))
1805 				insert_tag(sp, tag);/* return service */
1806 			if ((tag = get_tag(ph, PTT_HOST_UNIQ)))
1807 				insert_tag(sp, tag); /* return it */
1808 			insert_tag(sp, utag);	/* ac_cookie */
1809 			scan_tags(sp, ph);
1810 			make_packet(sp);
1811 			sp->state = PPPOE_NEWCONNECTED;
1812 
1813 			/* Send the PADS without a timeout - we're now connected. */
1814 			m0 = m_copypacket(sp->neg->m, M_NOWAIT);
1815 			NG_FWD_NEW_DATA(error, item, privp->ethernet_hook, m0);
1816 
1817 			/*
1818 			 * Having sent the last Negotiation header,
1819 			 * Set up the stored packet header to be correct for
1820 			 * the actual session. But keep the negotialtion stuff
1821 			 * around in case we need to resend this last packet.
1822 			 * We'll discard it when we move from NEWCONNECTED
1823 			 * to CONNECTED
1824 			 */
1825 			sp->pkt_hdr = neg->pkt->pkt_header;
1826 			/* Configure ethertype depending on what
1827 			 * ethertype was used at discovery phase */
1828 			if (sp->pkt_hdr.eh.ether_type ==
1829 			    ETHERTYPE_PPPOE_3COM_DISC)
1830 				sp->pkt_hdr.eh.ether_type
1831 					= ETHERTYPE_PPPOE_3COM_SESS;
1832 			else
1833 				sp->pkt_hdr.eh.ether_type
1834 					= ETHERTYPE_PPPOE_SESS;
1835 			sp->pkt_hdr.ph.code = 0;
1836 			pppoe_send_event(sp, NGM_PPPOE_SUCCESS);
1837 			break;
1838 		case	PADS_CODE:
1839 			/*
1840 			 * We are a client:
1841 			 * Use the host_uniq tag to find the hook this is in
1842 			 * response to. Take the session ID and store it away.
1843 			 * Also make sure the pre-made header is correct and
1844 			 * set us into Session mode.
1845 			 */
1846 			utag = get_tag(ph, PTT_HOST_UNIQ);
1847 			if (utag == NULL) {
1848 				LEAVE (ENETUNREACH);
1849 			}
1850 			sendhook = pppoe_finduniq(node, utag);
1851 			if (sendhook == NULL)
1852 				LEAVE(ENETUNREACH);
1853 
1854 			/*
1855 			 * Check the session is in the right state.
1856 			 * It needs to be in PPPOE_SREQ.
1857 			 */
1858 			sp = NG_HOOK_PRIVATE(sendhook);
1859 			if (sp->state != PPPOE_SREQ)
1860 				LEAVE(ENETUNREACH);
1861 			neg = sp->neg;
1862 			ng_uncallout(&neg->handle, node);
1863 			neg->pkt->pkt_header.ph.sid = wh->ph.sid;
1864 			sp->Session_ID = ntohs(wh->ph.sid);
1865 			pppoe_addsession(sp);
1866 			send_sessionid(sp);
1867 			neg->timeout = 0;
1868 			sp->state = PPPOE_CONNECTED;
1869 			/*
1870 			 * Now we have gone to Connected mode,
1871 			 * Free all resources needed for negotiation.
1872 			 * Keep a copy of the header we will be using.
1873 			 */
1874 			sp->pkt_hdr = neg->pkt->pkt_header;
1875 			if (privp->flags & COMPAT_3COM)
1876 				sp->pkt_hdr.eh.ether_type
1877 					= ETHERTYPE_PPPOE_3COM_SESS;
1878 			else
1879 				sp->pkt_hdr.eh.ether_type
1880 					= ETHERTYPE_PPPOE_SESS;
1881 			sp->pkt_hdr.ph.code = 0;
1882 			m_freem(neg->m);
1883 			free(sp->neg, M_NETGRAPH_PPPOE);
1884 			sp->neg = NULL;
1885 			if ((tag = get_tag(ph, PTT_MAX_PAYL)) &&
1886 			    (privp->max_payload.data != 0))
1887 				send_maxp(sp, tag);
1888 			pppoe_send_event(sp, NGM_PPPOE_SUCCESS);
1889 			break;
1890 		case	PADT_CODE:
1891 			/*
1892 			 * Find matching peer/session combination.
1893 			 */
1894 			sp = pppoe_findsession(privp, wh);
1895 			if (sp == NULL)
1896 				LEAVE(ENETUNREACH);
1897 			/* Disconnect that hook. */
1898 			ng_rmhook_self(sp->hook);
1899 			break;
1900 		case	PADM_CODE:
1901 			/*
1902 			 * We are a client:
1903 			 * find matching peer/session combination.
1904 			 */
1905 			sp = pppoe_findsession(privp, wh);
1906 			if (sp == NULL)
1907 				LEAVE (ENETUNREACH);
1908 			if ((tag = get_tag(ph, PTT_HURL)))
1909 				send_hurl(sp, tag);
1910 			if ((tag = get_tag(ph, PTT_MOTM)))
1911 				send_motm(sp, tag);
1912 			break;
1913 		default:
1914 			LEAVE(EPFNOSUPPORT);
1915 		}
1916 		break;
1917 	case	ETHERTYPE_PPPOE_3COM_SESS:
1918 	case	ETHERTYPE_PPPOE_SESS:
1919 		/*
1920 		 * Find matching peer/session combination.
1921 		 */
1922 		sp = pppoe_findsession(privp, wh);
1923 		if (sp == NULL)
1924 			LEAVE (ENETUNREACH);
1925 		m_adj(m, sizeof(*wh));
1926 
1927 		/* If packet too short, dump it. */
1928 		if (m->m_pkthdr.len < length)
1929 			LEAVE(EMSGSIZE);
1930 		/* Also need to trim excess at the end */
1931 		if (m->m_pkthdr.len > length) {
1932 			m_adj(m, -((int)(m->m_pkthdr.len - length)));
1933 		}
1934 		if ( sp->state != PPPOE_CONNECTED) {
1935 			if (sp->state == PPPOE_NEWCONNECTED) {
1936 				sp->state = PPPOE_CONNECTED;
1937 				/*
1938 				 * Now we have gone to Connected mode,
1939 				 * Free all resources needed for negotiation.
1940 				 * Be paranoid about whether there may be
1941 				 * a timeout.
1942 				 */
1943 				m_freem(sp->neg->m);
1944 				ng_uncallout(&sp->neg->handle, node);
1945 				free(sp->neg, M_NETGRAPH_PPPOE);
1946 				sp->neg = NULL;
1947 			} else {
1948 				LEAVE (ENETUNREACH);
1949 			}
1950 		}
1951 		NG_FWD_NEW_DATA(error, item, sp->hook, m);
1952 		break;
1953 	default:
1954 		LEAVE(EPFNOSUPPORT);
1955 	}
1956 quit:
1957 	if (item)
1958 		NG_FREE_ITEM(item);
1959 	NG_FREE_M(m);
1960 	return (error);
1961 }
1962 
1963 /*
1964  * Receive data from debug hook and bypass it to ether.
1965  */
1966 static int
1967 ng_pppoe_rcvdata_debug(hook_p hook, item_p item)
1968 {
1969 	node_p		node = NG_HOOK_NODE(hook);
1970 	const priv_p	privp = NG_NODE_PRIVATE(node);
1971 	int		error;
1972 
1973 	CTR6(KTR_NET, "%20s: node [%x] (%p) received %p on \"%s\" (%p)",
1974 	    __func__, node->nd_ID, node, item, hook->hk_name, hook);
1975 
1976 	NG_FWD_ITEM_HOOK(error, item, privp->ethernet_hook);
1977 	privp->packets_out++;
1978 	return (error);
1979 }
1980 
1981 /*
1982  * Do local shutdown processing..
1983  * If we are a persistent device, we might refuse to go away, and
1984  * we'd only remove our links and reset ourself.
1985  */
1986 static int
1987 ng_pppoe_shutdown(node_p node)
1988 {
1989 	const priv_p privp = NG_NODE_PRIVATE(node);
1990 	int	i;
1991 
1992 	for (i = 0; i < SESSHASHSIZE; i++)
1993 	    mtx_destroy(&privp->sesshash[i].mtx);
1994 	NG_NODE_SET_PRIVATE(node, NULL);
1995 	NG_NODE_UNREF(privp->node);
1996 	free(privp, M_NETGRAPH_PPPOE);
1997 	return (0);
1998 }
1999 
2000 /*
2001  * Hook disconnection
2002  *
2003  * Clean up all dangling links and information about the session/hook.
2004  * For this type, removal of the last link destroys the node.
2005  */
2006 static int
2007 ng_pppoe_disconnect(hook_p hook)
2008 {
2009 	node_p node = NG_HOOK_NODE(hook);
2010 	priv_p privp = NG_NODE_PRIVATE(node);
2011 	sessp	sp;
2012 
2013 	if (hook == privp->debug_hook) {
2014 		privp->debug_hook = NULL;
2015 	} else if (hook == privp->ethernet_hook) {
2016 		privp->ethernet_hook = NULL;
2017 		if (NG_NODE_IS_VALID(node))
2018 			ng_rmnode_self(node);
2019 	} else {
2020 		sp = NG_HOOK_PRIVATE(hook);
2021 		if (sp->state != PPPOE_SNONE ) {
2022 			pppoe_send_event(sp, NGM_PPPOE_CLOSE);
2023 		}
2024 		/*
2025 		 * According to the spec, if we are connected,
2026 		 * we should send a DISC packet if we are shutting down
2027 		 * a session.
2028 		 */
2029 		if ((privp->ethernet_hook)
2030 		&& ((sp->state == PPPOE_CONNECTED)
2031 		 || (sp->state == PPPOE_NEWCONNECTED))) {
2032 			struct mbuf *m;
2033 
2034 			/* Generate a packet of that type. */
2035 			m = m_gethdr(M_NOWAIT, MT_DATA);
2036 			if (m == NULL)
2037 				log(LOG_NOTICE, "ng_pppoe[%x]: session out of "
2038 				    "mbufs\n", node->nd_ID);
2039 			else {
2040 				struct pppoe_full_hdr *wh;
2041 				struct pppoe_tag *tag;
2042 				int	msglen = strlen(SIGNOFF);
2043 				int	error = 0;
2044 
2045 				wh = mtod(m, struct pppoe_full_hdr *);
2046 				bcopy(&sp->pkt_hdr, wh, sizeof(*wh));
2047 
2048 				/* Revert the stored header to DISC/PADT mode. */
2049 				wh->ph.code = PADT_CODE;
2050 				/*
2051 				 * Configure ethertype depending on what
2052 				 * was used during sessions stage.
2053 				 */
2054 				if (wh->eh.ether_type ==
2055 				    ETHERTYPE_PPPOE_3COM_SESS)
2056 					wh->eh.ether_type = ETHERTYPE_PPPOE_3COM_DISC;
2057 				else
2058 					wh->eh.ether_type = ETHERTYPE_PPPOE_DISC;
2059 				/*
2060 				 * Add a General error message and adjust
2061 				 * sizes.
2062 				 */
2063 				tag = (void *)(&wh->ph + 1);
2064 				tag->tag_type = PTT_GEN_ERR;
2065 				tag->tag_len = htons((u_int16_t)msglen);
2066 				strncpy((char *)(tag + 1), SIGNOFF, msglen);
2067 				m->m_pkthdr.len = m->m_len = sizeof(*wh) + sizeof(*tag) +
2068 				    msglen;
2069 				wh->ph.length = htons(sizeof(*tag) + msglen);
2070 				NG_SEND_DATA_ONLY(error,
2071 					privp->ethernet_hook, m);
2072 			}
2073 		}
2074 		if (sp->state == PPPOE_LISTENING)
2075 			LIST_REMOVE(sp, sessions);
2076 		else if (sp->Session_ID)
2077 			pppoe_delsession(sp);
2078 		/*
2079 		 * As long as we have somewhere to store the timeout handle,
2080 		 * we may have a timeout pending.. get rid of it.
2081 		 */
2082 		if (sp->neg) {
2083 			ng_uncallout(&sp->neg->handle, node);
2084 			if (sp->neg->m)
2085 				m_freem(sp->neg->m);
2086 			free(sp->neg, M_NETGRAPH_PPPOE);
2087 		}
2088 		free(sp, M_NETGRAPH_PPPOE);
2089 		NG_HOOK_SET_PRIVATE(hook, NULL);
2090 	}
2091 	if ((NG_NODE_NUMHOOKS(node) == 0) &&
2092 	    (NG_NODE_IS_VALID(node)))
2093 		ng_rmnode_self(node);
2094 	return (0);
2095 }
2096 
2097 /*
2098  * Timeouts come here.
2099  */
2100 static void
2101 pppoe_ticker(node_p node, hook_p hook, void *arg1, int arg2)
2102 {
2103 	priv_p privp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
2104 	sessp	sp = NG_HOOK_PRIVATE(hook);
2105 	negp	neg = sp->neg;
2106 	struct mbuf *m0 = NULL;
2107 	int	error = 0;
2108 
2109 	CTR6(KTR_NET, "%20s: node [%x] (%p) hook \"%s\" (%p) session %d",
2110 	    __func__, node->nd_ID, node, hook->hk_name, hook, sp->Session_ID);
2111 	switch(sp->state) {
2112 		/*
2113 		 * Resend the last packet, using an exponential backoff.
2114 		 * After a period of time, stop growing the backoff,
2115 		 * And either leave it, or revert to the start.
2116 		 */
2117 	case	PPPOE_SINIT:
2118 	case	PPPOE_SREQ:
2119 		/* Timeouts on these produce resends. */
2120 		m0 = m_copypacket(sp->neg->m, M_NOWAIT);
2121 		NG_SEND_DATA_ONLY( error, privp->ethernet_hook, m0);
2122 		ng_callout(&neg->handle, node, hook, neg->timeout * hz,
2123 		    pppoe_ticker, NULL, 0);
2124 		if ((neg->timeout <<= 1) > PPPOE_TIMEOUT_LIMIT) {
2125 			if (sp->state == PPPOE_SREQ) {
2126 				/* Revert to SINIT mode. */
2127 				pppoe_start(sp);
2128 			} else {
2129 				neg->timeout = PPPOE_TIMEOUT_LIMIT;
2130 			}
2131 		}
2132 		break;
2133 	case	PPPOE_PRIMED:
2134 	case	PPPOE_SOFFER:
2135 		/* A timeout on these says "give up" */
2136 		ng_rmhook_self(hook);
2137 		break;
2138 	default:
2139 		/* Timeouts have no meaning in other states. */
2140 		log(LOG_NOTICE, "ng_pppoe[%x]: unexpected timeout\n",
2141 		    node->nd_ID);
2142 	}
2143 }
2144 
2145 /*
2146  * Parse an incoming packet to see if any tags should be copied to the
2147  * output packet. Don't do any tags that have been handled in the main
2148  * state machine.
2149  */
2150 static const struct pppoe_tag*
2151 scan_tags(sessp	sp, const struct pppoe_hdr* ph)
2152 {
2153 	const char *const end = (const char *)next_tag(ph);
2154 	const char *ptn;
2155 	const struct pppoe_tag *pt = (const void *)(ph + 1);
2156 
2157 	/*
2158 	 * Keep processing tags while a tag header will still fit.
2159 	 */
2160 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
2161 
2162 	while((const char*)(pt + 1) <= end) {
2163 		/*
2164 		 * If the tag data would go past the end of the packet, abort.
2165 		 */
2166 		ptn = (((const char *)(pt + 1)) + ntohs(pt->tag_len));
2167 		if(ptn > end)
2168 			return NULL;
2169 
2170 		switch (pt->tag_type) {
2171 		case	PTT_RELAY_SID:
2172 			insert_tag(sp, pt);
2173 			break;
2174 		case	PTT_EOL:
2175 			return NULL;
2176 		case	PTT_SRV_NAME:
2177 		case	PTT_AC_NAME:
2178 		case	PTT_HOST_UNIQ:
2179 		case	PTT_AC_COOKIE:
2180 		case	PTT_VENDOR:
2181 		case	PTT_SRV_ERR:
2182 		case	PTT_SYS_ERR:
2183 		case	PTT_GEN_ERR:
2184 		case	PTT_MAX_PAYL:
2185 		case	PTT_HURL:
2186 		case	PTT_MOTM:
2187 			break;
2188 		}
2189 		pt = (const struct pppoe_tag*)ptn;
2190 	}
2191 	return NULL;
2192 }
2193 
2194 static	int
2195 pppoe_send_event(sessp sp, enum cmd cmdid)
2196 {
2197 	int error;
2198 	struct ng_mesg *msg;
2199 	struct ngpppoe_sts *sts;
2200 
2201 	CTR2(KTR_NET, "%20s: called %d", __func__, sp->Session_ID);
2202 
2203 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, cmdid,
2204 			sizeof(struct ngpppoe_sts), M_NOWAIT);
2205 	if (msg == NULL)
2206 		return (ENOMEM);
2207 	sts = (struct ngpppoe_sts *)msg->data;
2208 	strncpy(sts->hook, NG_HOOK_NAME(sp->hook), NG_HOOKSIZ);
2209 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, 0);
2210 	return (error);
2211 }
2212