xref: /freebsd/sys/netgraph/ng_pppoe.c (revision b601c69bdbe8755d26570261d7fd4c02ee4eff74)
1 
2 /*
3  * ng_pppoe.c
4  *
5  * Copyright (c) 1996-1999 Whistle Communications, Inc.
6  * All rights reserved.
7  *
8  * Subject to the following obligations and disclaimer of warranty, use and
9  * redistribution of this software, in source or object code forms, with or
10  * without modifications are expressly permitted by Whistle Communications;
11  * provided, however, that:
12  * 1. Any and all reproductions of the source or object code must include the
13  *    copyright notice above and the following disclaimer of warranties; and
14  * 2. No rights are granted, in any manner or form, to use Whistle
15  *    Communications, Inc. trademarks, including the mark "WHISTLE
16  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
17  *    such appears in the above copyright notice or in the software.
18  *
19  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
20  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
21  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
22  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
23  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
24  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
25  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
26  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
27  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
28  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
29  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
30  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
31  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
35  * OF SUCH DAMAGE.
36  *
37  * Author: Julian Elischer <julian@whistle.com>
38  *
39  * $FreeBSD$
40  * $Whistle: ng_pppoe.c,v 1.10 1999/11/01 09:24:52 julian Exp $
41  */
42 #if 0
43 #define AAA printf("pppoe: %s\n", __FUNCTION__ );
44 #define BBB printf("-%d-", __LINE__ );
45 #else
46 #define AAA
47 #define BBB
48 #endif
49 
50 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/kernel.h>
53 #include <sys/mbuf.h>
54 #include <sys/malloc.h>
55 #include <sys/errno.h>
56 #include <net/ethernet.h>
57 
58 #include <netgraph/ng_message.h>
59 #include <netgraph/netgraph.h>
60 #include <netgraph/ng_pppoe.h>
61 
62 #define SIGNOFF "session closed"
63 
64 /*
65  * This section contains the netgraph method declarations for the
66  * sample node. These methods define the netgraph 'type'.
67  */
68 
69 static ng_constructor_t	ng_pppoe_constructor;
70 static ng_rcvmsg_t	ng_pppoe_rcvmsg;
71 static ng_shutdown_t	ng_pppoe_rmnode;
72 static ng_newhook_t	ng_pppoe_newhook;
73 static ng_connect_t	ng_pppoe_connect;
74 static ng_rcvdata_t	ng_pppoe_rcvdata;
75 static ng_disconnect_t	ng_pppoe_disconnect;
76 
77 /* Netgraph node type descriptor */
78 static struct ng_type typestruct = {
79 	NG_VERSION,
80 	NG_PPPOE_NODE_TYPE,
81 	NULL,
82 	ng_pppoe_constructor,
83 	ng_pppoe_rcvmsg,
84 	ng_pppoe_rmnode,
85 	ng_pppoe_newhook,
86 	NULL,
87 	ng_pppoe_connect,
88 	ng_pppoe_rcvdata,
89 	ng_pppoe_rcvdata,
90 	ng_pppoe_disconnect,
91 	NULL
92 };
93 NETGRAPH_INIT(pppoe, &typestruct);
94 
95 /*
96  * States for the session state machine.
97  * These have no meaning if there is no hook attached yet.
98  */
99 enum state {
100     PPPOE_SNONE=0,	/* [both] Initial state */
101     PPPOE_LISTENING,	/* [Daemon] Listening for discover initiation pkt */
102     PPPOE_SINIT,	/* [Client] Sent discovery initiation */
103     PPPOE_PRIMED,	/* [Server] Awaiting PADI from daemon */
104     PPPOE_SOFFER,	/* [Server] Sent offer message  (got PADI)*/
105     PPPOE_SREQ,		/* [Client] Sent a Request */
106     PPPOE_NEWCONNECTED,	/* [Server] Connection established, No data received */
107     PPPOE_CONNECTED,	/* [Both] Connection established, Data received */
108     PPPOE_DEAD		/* [Both] */
109 };
110 
111 #define NUMTAGS 20 /* number of tags we are set up to work with */
112 
113 /*
114  * Information we store for each hook on each node for negotiating the
115  * session. The mbuf and cluster are freed once negotiation has completed.
116  * The whole negotiation block is then discarded.
117  */
118 
119 struct sess_neg {
120 	struct mbuf 		*m; /* holds cluster with last sent packet */
121 	union	packet		*pkt; /* points within the above cluster */
122 	struct callout_handle	timeout_handle;   /* see timeout(9) */
123 	u_int			timeout; /* 0,1,2,4,8,16 etc. seconds */
124 	u_int			numtags;
125 	struct pppoe_tag	*tags[NUMTAGS];
126 	u_int			service_len;
127 	u_int			ac_name_len;
128 
129 	struct datatag		service;
130 	struct datatag		ac_name;
131 };
132 typedef struct sess_neg *negp;
133 
134 /*
135  * Session information that is needed after connection.
136  */
137 struct session {
138 	hook_p  		hook;
139 	u_int16_t		Session_ID;
140 	struct session		*hash_next; /* not yet uesed */
141 	enum state		state;
142 	char			creator[NG_NODELEN + 1]; /* who to notify */
143 	struct pppoe_full_hdr	pkt_hdr;	/* used when connected */
144 	negp			neg;		/* used when negotiating */
145 };
146 typedef struct session *sessp;
147 
148 /*
149  * Information we store for each node
150  */
151 struct PPPOE {
152 	node_p		node;		/* back pointer to node */
153 	hook_p  	ethernet_hook;
154 	hook_p  	debug_hook;
155 	u_int   	packets_in;	/* packets in from ethernet */
156 	u_int   	packets_out;	/* packets out towards ethernet */
157 	u_int32_t	flags;
158 	/*struct session *buckets[HASH_SIZE];*/	/* not yet used */
159 };
160 typedef struct PPPOE *priv_p;
161 
162 const struct ether_header eh_prototype =
163 	{{0xff,0xff,0xff,0xff,0xff,0xff},
164 	 {0x00,0x00,0x00,0x00,0x00,0x00},
165 	 ETHERTYPE_PPPOE_DISC};
166 
167 union uniq {
168 	char bytes[sizeof(void *)];
169 	void * pointer;
170 	};
171 
172 #define	LEAVE(x) do { error = x; goto quit; } while(0)
173 static void	pppoe_start(sessp sp);
174 static void	sendpacket(sessp sp);
175 static void	pppoe_ticker(void *arg);
176 static struct pppoe_tag* scan_tags(sessp	sp, struct pppoe_hdr* ph);
177 static	int	pppoe_send_event(sessp sp, enum cmd cmdid);
178 
179 /*************************************************************************
180  * Some basic utilities  from the Linux version with author's permission.*
181  * Author:	Michal Ostrowski <mostrows@styx.uwaterloo.ca>		 *
182  ************************************************************************/
183 
184 /*
185  * Generate a new session id
186  * XXX find out the FreeBSD locking scheme.
187  */
188 static u_int16_t
189 get_new_sid(node_p node)
190 {
191 	static int pppoe_sid = 10;
192 	sessp sp;
193 	hook_p	hook;
194 	u_int16_t val;
195 	priv_p privp = node->private;
196 
197 AAA
198 restart:
199 	val = pppoe_sid++;
200 	/*
201 	 * Spec says 0xFFFF is reserved.
202 	 * Also don't use 0x0000
203 	 */
204 	if (val == 0xffff) {
205 		pppoe_sid = 20;
206 		goto restart;
207 	}
208 
209 	/* Check it isn't already in use */
210 	LIST_FOREACH(hook, &node->hooks, hooks) {
211 		/* don't check special hooks */
212 		if ((hook->private == &privp->debug_hook)
213 		||  (hook->private == &privp->ethernet_hook))
214 			continue;
215 		sp = hook->private;
216 		if (sp->Session_ID == val)
217 			goto restart;
218 	}
219 
220 	return val;
221 }
222 
223 
224 /*
225  * Return the location where the next tag can be put
226  */
227 static __inline struct pppoe_tag*
228 next_tag(struct pppoe_hdr* ph)
229 {
230 	return (struct pppoe_tag*)(((char*)&ph->tag[0]) + ntohs(ph->length));
231 }
232 
233 /*
234  * Look for a tag of a specific type
235  * Don't trust any length the other end says.
236  * but assume we already sanity checked ph->length.
237  */
238 static struct pppoe_tag*
239 get_tag(struct pppoe_hdr* ph, u_int16_t idx)
240 {
241 	char *end = (char *)next_tag(ph);
242 	char *ptn;
243 	struct pppoe_tag *pt = &ph->tag[0];
244 	/*
245 	 * Keep processing tags while a tag header will still fit.
246 	 */
247 AAA
248 	while((char*)(pt + 1) <= end) {
249 	    /*
250 	     * If the tag data would go past the end of the packet, abort.
251 	     */
252 	    ptn = (((char *)(pt + 1)) + ntohs(pt->tag_len));
253 	    if(ptn > end)
254 		return NULL;
255 
256 	    if(pt->tag_type == idx)
257 		return pt;
258 
259 	    pt = (struct pppoe_tag*)ptn;
260 	}
261 	return NULL;
262 }
263 
264 /**************************************************************************
265  * inlines to initialise or add tags to a session's tag list,
266  **************************************************************************/
267 /*
268  * Initialise the session's tag list
269  */
270 static void
271 init_tags(sessp sp)
272 {
273 AAA
274 	if(sp->neg == NULL) {
275 		printf("pppoe: asked to init NULL neg pointer\n");
276 		return;
277 	}
278 	sp->neg->numtags = 0;
279 }
280 
281 static void
282 insert_tag(sessp sp, struct pppoe_tag *tp)
283 {
284 	int	i;
285 	negp neg;
286 
287 AAA
288 	if((neg = sp->neg) == NULL) {
289 		printf("pppoe: asked to use NULL neg pointer\n");
290 		return;
291 	}
292 	if ((i = neg->numtags++) < NUMTAGS) {
293 		neg->tags[i] = tp;
294 	} else {
295 		printf("pppoe: asked to add too many tags to packet\n");
296 		neg->numtags--;
297 	}
298 }
299 
300 /*
301  * Make up a packet, using the tags filled out for the session.
302  *
303  * Assume that the actual pppoe header and ethernet header
304  * are filled out externally to this routine.
305  * Also assume that neg->wh points to the correct
306  * location at the front of the buffer space.
307  */
308 static void
309 make_packet(sessp sp) {
310 	struct pppoe_full_hdr *wh = &sp->neg->pkt->pkt_header;
311 	struct pppoe_tag **tag;
312 	char *dp;
313 	int count;
314 	int tlen;
315 	u_int16_t length = 0;
316 
317 AAA
318 	if ((sp->neg == NULL) || (sp->neg->m == NULL)) {
319 		printf("pppoe: make_packet called from wrong state\n");
320 	}
321 	dp = (char *)wh->ph.tag;
322 	for (count = 0, tag = sp->neg->tags;
323 	    ((count < sp->neg->numtags) && (count < NUMTAGS));
324 	    tag++, count++) {
325 		tlen = ntohs((*tag)->tag_len) + sizeof(**tag);
326 		if ((length + tlen) > (ETHER_MAX_LEN - 4 - sizeof(*wh))) {
327 			printf("pppoe: tags too long\n");
328 			sp->neg->numtags = count;
329 			break;	/* XXX chop off what's too long */
330 		}
331 		bcopy((char *)*tag, (char *)dp, tlen);
332 		length += tlen;
333 		dp += tlen;
334 	}
335  	wh->ph.length = htons(length);
336 	sp->neg->m->m_len = length + sizeof(*wh);
337 	sp->neg->m->m_pkthdr.len = length + sizeof(*wh);
338 }
339 
340 /**************************************************************************
341  * Routine to match a service offered					  *
342  **************************************************************************/
343 /*
344  * Find a hook that has a service string that matches that
345  * we are seeking. for now use a simple string.
346  * In the future we may need something like regexp().
347  * for testing allow a null string to match 1st found and a null service
348  * to match all requests. Also make '*' do the same.
349  */
350 static hook_p
351 pppoe_match_svc(node_p node, char *svc_name, int svc_len)
352 {
353 	sessp	sp	= NULL;
354 	negp	neg	= NULL;
355 	priv_p	privp	= node->private;
356 	hook_p hook;
357 
358 AAA
359 	LIST_FOREACH(hook, &node->hooks, hooks) {
360 
361 		/* skip any hook that is debug or ethernet */
362 		if ((hook->private == &privp->debug_hook)
363 		||  (hook->private == &privp->ethernet_hook))
364 			continue;
365 		sp = hook->private;
366 
367 		/* Skip any sessions which are not in LISTEN mode. */
368 		if ( sp->state != PPPOE_LISTENING)
369 			continue;
370 
371 		neg = sp->neg;
372 		/* XXX check validity of this */
373 		/* special case, NULL request. match 1st found. */
374 		if (svc_len == 0)
375 			break;
376 
377 		/* XXX check validity of this */
378 		/* Special case for a blank or "*" service name (wildcard) */
379 		if ((neg->service_len == 0)
380 		||  ((neg->service_len == 1)
381 		  && (neg->service.data[0] == '*'))) {
382 			break;
383 		}
384 
385 		/* If the lengths don't match, that aint it. */
386 		if (neg->service_len != svc_len)
387 			continue;
388 
389 		/* An exact match? */
390 		if (strncmp(svc_name, neg->service.data, svc_len) == 0)
391 			break;
392 	}
393 	return (hook);
394 }
395 /**************************************************************************
396  * Routine to find a particular session that matches an incoming packet	  *
397  **************************************************************************/
398 static hook_p
399 pppoe_findsession(node_p node, struct pppoe_full_hdr *wh)
400 {
401 	sessp	sp = NULL;
402 	hook_p hook = NULL;
403 	priv_p	privp = node->private;
404 	u_int16_t	session = ntohs(wh->ph.sid);
405 
406 	/*
407 	 * find matching peer/session combination.
408 	 */
409 AAA
410 	LIST_FOREACH(hook, &node->hooks, hooks) {
411 		/* don't check special hooks */
412 		if ((hook->private == &privp->debug_hook)
413 		||  (hook->private == &privp->ethernet_hook)) {
414 			continue;
415 		}
416 		sp = hook->private;
417 		if ( ( (sp->state == PPPOE_CONNECTED)
418 		    || (sp->state == PPPOE_NEWCONNECTED) )
419 		&& (sp->Session_ID == session)
420 		&& (bcmp(sp->pkt_hdr.eh.ether_dhost,
421 		    wh->eh.ether_shost,
422 		    ETHER_ADDR_LEN)) == 0) {
423 			break;
424 		}
425 	}
426 	return (hook);
427 }
428 
429 static hook_p
430 pppoe_finduniq(node_p node, struct pppoe_tag *tag)
431 {
432 	hook_p hook = NULL;
433 	priv_p	privp = node->private;
434 	union uniq		uniq;
435 
436 AAA
437 	bcopy(tag->tag_data, uniq.bytes, sizeof(void *));
438 	/* cycle through all known hooks */
439 	LIST_FOREACH(hook, &node->hooks, hooks) {
440 		/* don't check special hooks */
441 		if ((hook->private == &privp->debug_hook)
442 		||  (hook->private == &privp->ethernet_hook))
443 			continue;
444 		if (uniq.pointer == hook->private)
445 			break;
446 	}
447 	return (hook);
448 }
449 
450 /**************************************************************************
451  * start of Netgraph entrypoints					  *
452  **************************************************************************/
453 
454 /*
455  * Allocate the private data structure and the generic node
456  * and link them together.
457  *
458  * ng_make_node_common() returns with a generic node struct
459  * with a single reference for us.. we transfer it to the
460  * private structure.. when we free the private struct we must
461  * unref the node so it gets freed too.
462  *
463  * If this were a device node than this work would be done in the attach()
464  * routine and the constructor would return EINVAL as you should not be able
465  * to creatednodes that depend on hardware (unless you can add the hardware :)
466  */
467 static int
468 ng_pppoe_constructor(node_p *nodep)
469 {
470 	priv_p privdata;
471 	int error;
472 
473 AAA
474 	/* Initialize private descriptor */
475 	MALLOC(privdata, priv_p, sizeof(*privdata), M_NETGRAPH, M_WAITOK);
476 	if (privdata == NULL)
477 		return (ENOMEM);
478 	bzero(privdata, sizeof(*privdata));
479 
480 	/* Call the 'generic' (ie, superclass) node constructor */
481 	if ((error = ng_make_node_common(&typestruct, nodep))) {
482 		FREE(privdata, M_NETGRAPH);
483 		return (error);
484 	}
485 
486 	/* Link structs together; this counts as our one reference to *nodep */
487 	(*nodep)->private = privdata;
488 	privdata->node = *nodep;
489 	return (0);
490 }
491 
492 /*
493  * Give our ok for a hook to be added...
494  * point the hook's private info to the hook structure.
495  *
496  * The following hook names are special:
497  *  Ethernet:  the hook that should be connected to a NIC.
498  *  debug:	copies of data sent out here  (when I write the code).
499  */
500 static int
501 ng_pppoe_newhook(node_p node, hook_p hook, const char *name)
502 {
503 	const priv_p privp = node->private;
504 	sessp sp;
505 
506 AAA
507 	if (strcmp(name, NG_PPPOE_HOOK_ETHERNET) == 0) {
508 		privp->ethernet_hook = hook;
509 		hook->private = &privp->ethernet_hook;
510 	} else if (strcmp(name, NG_PPPOE_HOOK_DEBUG) == 0) {
511 		privp->debug_hook = hook;
512 		hook->private = &privp->debug_hook;
513 	} else {
514 		/*
515 		 * Any other unique name is OK.
516 		 * The infrastructure has already checked that it's unique,
517 		 * so just allocate it and hook it in.
518 		 */
519 		MALLOC(sp, sessp, sizeof(*sp), M_NETGRAPH, M_WAITOK);
520 		if (sp == NULL) {
521 				return (ENOMEM);
522 		}
523 		bzero(sp, sizeof(*sp));
524 
525 		hook->private = sp;
526 		sp->hook = hook;
527 	}
528 	return(0);
529 }
530 
531 /*
532  * Get a netgraph control message.
533  * Check it is one we understand. If needed, send a response.
534  * We sometimes save the address for an async action later.
535  * Always free the message.
536  */
537 static int
538 ng_pppoe_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
539 		struct ng_mesg **rptr, hook_p lasthook)
540 {
541 	priv_p privp = node->private;
542 	struct ngpppoe_init_data *ourmsg = NULL;
543 	struct ng_mesg *resp = NULL;
544 	int error = 0;
545 	hook_p hook = NULL;
546 	sessp sp = NULL;
547 	negp neg = NULL;
548 
549 AAA
550 	/* Deal with message according to cookie and command */
551 	switch (msg->header.typecookie) {
552 	case NGM_PPPOE_COOKIE:
553 		switch (msg->header.cmd) {
554 		case NGM_PPPOE_CONNECT:
555 		case NGM_PPPOE_LISTEN:
556 		case NGM_PPPOE_OFFER:
557 			ourmsg = (struct ngpppoe_init_data *)msg->data;
558 			if (( sizeof(*ourmsg) > msg->header.arglen)
559 			|| ((sizeof(*ourmsg) + ourmsg->data_len)
560 			    > msg->header.arglen)) {
561 				printf("pppoe_rcvmsg: bad arg size");
562 				LEAVE(EMSGSIZE);
563 			}
564 			if (ourmsg->data_len > PPPOE_SERVICE_NAME_SIZE) {
565 				printf("pppoe: init data too long (%d)\n",
566 							ourmsg->data_len);
567 				LEAVE(EMSGSIZE);
568 			}
569 			/* make sure strcmp will terminate safely */
570 			ourmsg->hook[sizeof(ourmsg->hook) - 1] = '\0';
571 
572 			/* cycle through all known hooks */
573 			LIST_FOREACH(hook, &node->hooks, hooks) {
574 				if (hook->name
575 				&& strcmp(hook->name, ourmsg->hook) == 0)
576 					break;
577 			}
578 			if (hook == NULL) {
579 				LEAVE(ENOENT);
580 			}
581 			if ((hook->private == &privp->debug_hook)
582 			||  (hook->private == &privp->ethernet_hook)) {
583 				LEAVE(EINVAL);
584 			}
585 			sp = hook->private;
586 			if (sp->state |= PPPOE_SNONE) {
587 				printf("pppoe: Session already active\n");
588 				LEAVE(EISCONN);
589 			}
590 
591 			/*
592 			 * set up prototype header
593 			 */
594 			MALLOC(neg, negp, sizeof(*neg), M_NETGRAPH, M_WAITOK);
595 
596 			if (neg == NULL) {
597 				printf("pppoe: Session out of memory\n");
598 				LEAVE(ENOMEM);
599 			}
600 			bzero(neg, sizeof(*neg));
601 			MGETHDR(neg->m, M_DONTWAIT, MT_DATA);
602 			if(neg->m == NULL) {
603 				printf("pppoe: Session out of mbufs\n");
604 				FREE(neg, M_NETGRAPH);
605 				LEAVE(ENOBUFS);
606 			}
607 			neg->m->m_pkthdr.rcvif = NULL;
608 			MCLGET(neg->m, M_DONTWAIT);
609 			if ((neg->m->m_flags & M_EXT) == 0) {
610 				printf("pppoe: Session out of mcls\n");
611 				m_freem(neg->m);
612 				FREE(neg, M_NETGRAPH);
613 				LEAVE(ENOBUFS);
614 			}
615 			sp->neg = neg;
616 			callout_handle_init( &neg->timeout_handle);
617 			neg->m->m_len = sizeof(struct pppoe_full_hdr);
618 			neg->pkt = mtod(neg->m, union packet*);
619 			neg->pkt->pkt_header.eh = eh_prototype;
620 			neg->pkt->pkt_header.ph.ver = 0x1;
621 			neg->pkt->pkt_header.ph.type = 0x1;
622 			neg->pkt->pkt_header.ph.sid = 0x0000;
623 			neg->timeout = 0;
624 
625 			strncpy(sp->creator, retaddr, NG_NODELEN);
626 			sp->creator[NG_NODELEN] = '\0';
627 		}
628 		switch (msg->header.cmd) {
629 		case NGM_PPPOE_GET_STATUS:
630 		    {
631 			struct ngpppoestat *stats;
632 
633 			NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT);
634 			if (!resp) {
635 				LEAVE(ENOMEM);
636 			}
637 			stats = (struct ngpppoestat *) resp->data;
638 			stats->packets_in = privp->packets_in;
639 			stats->packets_out = privp->packets_out;
640 			break;
641 		    }
642 		case NGM_PPPOE_CONNECT:
643 			/*
644 			 * Check the hook exists and is Uninitialised.
645 			 * Send a PADI request, and start the timeout logic.
646 			 * Store the originator of this message so we can send
647 			 * a success of fail message to them later.
648 			 * Move the session to SINIT
649 			 * Set up the session to the correct state and
650 			 * start it.
651 			 */
652 			neg->service.hdr.tag_type = PTT_SRV_NAME;
653 			neg->service.hdr.tag_len =
654 					htons((u_int16_t)ourmsg->data_len);
655 			if (ourmsg->data_len) {
656 				bcopy(ourmsg->data,
657 					neg->service.data, ourmsg->data_len);
658 			}
659 			neg->service_len = ourmsg->data_len;
660 			pppoe_start(sp);
661 			break;
662 		case NGM_PPPOE_LISTEN:
663 			/*
664 			 * Check the hook exists and is Uninitialised.
665 			 * Install the service matching string.
666 			 * Store the originator of this message so we can send
667 			 * a success of fail message to them later.
668 			 * Move the hook to 'LISTENING'
669 
670 			 */
671 			neg->service.hdr.tag_type = PTT_SRV_NAME;
672 			neg->service.hdr.tag_len =
673 					htons((u_int16_t)ourmsg->data_len);
674 
675 			if (ourmsg->data_len) {
676 				bcopy(ourmsg->data,
677 					neg->service.data, ourmsg->data_len);
678 			}
679 			neg->service_len = ourmsg->data_len;
680 			neg->pkt->pkt_header.ph.code = PADT_CODE;
681 			/*
682 			 * wait for PADI packet coming from ethernet
683 			 */
684 			sp->state = PPPOE_LISTENING;
685 			break;
686 		case NGM_PPPOE_OFFER:
687 			/*
688 			 * Check the hook exists and is Uninitialised.
689 			 * Store the originator of this message so we can send
690 			 * a success of fail message to them later.
691 			 * Store the AC-Name given and go to PRIMED.
692 			 */
693 			neg->ac_name.hdr.tag_type = PTT_AC_NAME;
694 			neg->ac_name.hdr.tag_len =
695 					htons((u_int16_t)ourmsg->data_len);
696 			if (ourmsg->data_len) {
697 				bcopy(ourmsg->data,
698 					neg->ac_name.data, ourmsg->data_len);
699 			}
700 			neg->ac_name_len = ourmsg->data_len;
701 			neg->pkt->pkt_header.ph.code = PADO_CODE;
702 			/*
703 			 * Wait for PADI packet coming from hook
704 			 */
705 			sp->state = PPPOE_PRIMED;
706 			break;
707 		default:
708 			LEAVE(EINVAL);
709 		}
710 		break;
711 	default:
712 		LEAVE(EINVAL);
713 	}
714 
715 	/* Take care of synchronous response, if any */
716 	if (rptr)
717 		*rptr = resp;
718 	else if (resp)
719 		FREE(resp, M_NETGRAPH);
720 
721 	/* Free the message and return */
722 quit:
723 	FREE(msg, M_NETGRAPH);
724 	return(error);
725 }
726 
727 /*
728  * Start a client into the first state. A separate function because
729  * it can be needed if the negotiation times out.
730  */
731 static void
732 pppoe_start(sessp sp)
733 {
734 	struct {
735 		struct pppoe_tag hdr;
736 		union	uniq	data;
737 	} uniqtag;
738 
739 	/*
740 	 * kick the state machine into starting up
741 	 */
742 AAA
743 	sp->state = PPPOE_SINIT;
744 	/* reset the packet header to broadcast */
745 	sp->neg->pkt->pkt_header.eh = eh_prototype;
746 	sp->neg->pkt->pkt_header.ph.code = PADI_CODE;
747 	uniqtag.hdr.tag_type = PTT_HOST_UNIQ;
748 	uniqtag.hdr.tag_len = htons((u_int16_t)sizeof(uniqtag.data));
749 	uniqtag.data.pointer = sp;
750 	init_tags(sp);
751 	insert_tag(sp, &sp->neg->service.hdr);
752 	insert_tag(sp, &uniqtag.hdr);
753 	make_packet(sp);
754 	sendpacket(sp);
755 }
756 
757 /*
758  * Receive data, and do something with it.
759  * The caller will never free m or meta, so
760  * if we use up this data or abort we must free BOTH of these.
761  */
762 static int
763 ng_pppoe_rcvdata(hook_p hook, struct mbuf *m, meta_p meta,
764 		struct mbuf **ret_m, meta_p *ret_meta)
765 {
766 	node_p			node = hook->node;
767 	const priv_p		privp = node->private;
768 	sessp			sp = hook->private;
769 	struct pppoe_full_hdr	*wh;
770 	struct pppoe_hdr	*ph;
771 	int			error = 0;
772 	u_int16_t		session;
773 	u_int16_t		length;
774 	u_int8_t		code;
775 	struct pppoe_tag	*utag = NULL, *tag = NULL;
776 	hook_p 			sendhook;
777 	struct {
778 		struct pppoe_tag hdr;
779 		union	uniq	data;
780 	} uniqtag;
781 	negp			neg = NULL;
782 
783 AAA
784 	if (hook->private == &privp->debug_hook) {
785 		/*
786 		 * Data from the debug hook gets sent without modification
787 		 * straight to the ethernet.
788 		 */
789 		NG_SEND_DATA( error, privp->ethernet_hook, m, meta);
790 	 	privp->packets_out++;
791 	} else if (hook->private == &privp->ethernet_hook) {
792 		/*
793 		 * Incoming data.
794 		 * Dig out various fields from the packet.
795 		 * use them to decide where to send it.
796 		 */
797 
798  		privp->packets_in++;
799 		if( m->m_len < sizeof(*wh)) {
800 			m = m_pullup(m, sizeof(*wh)); /* Checks length */
801 			if (m == NULL) {
802 				printf("couldn't m_pullup\n");
803 				LEAVE(ENOBUFS);
804 			}
805 		}
806 		wh = mtod(m, struct pppoe_full_hdr *);
807 		ph = &wh->ph;
808 		session = ntohs(wh->ph.sid);
809 		length = ntohs(wh->ph.length);
810 		code = wh->ph.code;
811 		switch(wh->eh.ether_type) {
812 		case	ETHERTYPE_PPPOE_DISC:
813 			/*
814 			 * We need to try to make sure that the tag area
815 			 * is contiguous, or we could wander off the end
816 			 * of a buffer and make a mess.
817 			 * (Linux wouldn't have this problem).
818 			 */
819 /*XXX fix this mess */
820 
821 			if (m->m_pkthdr.len <= MHLEN) {
822 				if( m->m_len < m->m_pkthdr.len) {
823 					m = m_pullup(m, m->m_pkthdr.len);
824 					if (m == NULL) {
825 						printf("couldn't m_pullup\n");
826 						LEAVE(ENOBUFS);
827 					}
828 				}
829 			}
830 			if (m->m_len != m->m_pkthdr.len) {
831 				/*
832 				 * It's not all in one piece.
833 				 * We need to do extra work.
834 				 */
835 				printf("packet fragmented\n");
836 				LEAVE(EMSGSIZE);
837 			}
838 
839 			switch(code) {
840 			case	PADI_CODE:
841 				/*
842 				 * We are a server:
843 				 * Look for a hook with the required service
844 				 * and send the ENTIRE packet up there.
845 				 * It should come back to a new hook in
846 				 * PRIMED state. Look there for further
847 				 * processing.
848 				 */
849 				tag = get_tag(ph, PTT_SRV_NAME);
850 				if (tag == NULL) {
851 					printf("no service tag\n");
852 					LEAVE(ENETUNREACH);
853 				}
854 				sendhook = pppoe_match_svc(hook->node,
855 			    		tag->tag_data, ntohs(tag->tag_len));
856 				if (sendhook) {
857 					NG_SEND_DATA(error, sendhook, m, meta);
858 				} else {
859 					printf("no such service\n");
860 					LEAVE(ENETUNREACH);
861 				}
862 				break;
863 			case	PADO_CODE:
864 				/*
865 				 * We are a client:
866 				 * Use the host_uniq tag to find the
867 				 * hook this is in response to.
868 				 * Received #2, now send #3
869 				 * For now simply accept the first we receive.
870 				 */
871 				utag = get_tag(ph, PTT_HOST_UNIQ);
872 				if ((utag == NULL)
873 				|| (ntohs(utag->tag_len) != sizeof(sp))) {
874 					printf("no host unique field\n");
875 					LEAVE(ENETUNREACH);
876 				}
877 
878 				sendhook = pppoe_finduniq(node, utag);
879 				if (sendhook == NULL) {
880 					printf("no matching session\n");
881 					LEAVE(ENETUNREACH);
882 				}
883 
884 				/*
885 				 * Check the session is in the right state.
886 				 * It needs to be in PPPOE_SINIT.
887 				 */
888 				sp = sendhook->private;
889 				if (sp->state != PPPOE_SINIT) {
890 					printf("session in wrong state\n");
891 					LEAVE(ENETUNREACH);
892 				}
893 				neg = sp->neg;
894 				untimeout(pppoe_ticker, sendhook,
895 				    neg->timeout_handle);
896 
897 				/*
898 				 * This is the first time we hear
899 				 * from the server, so note it's
900 				 * unicast address, replacing the
901 				 * broadcast address .
902 				 */
903 				bcopy(wh->eh.ether_shost,
904 					neg->pkt->pkt_header.eh.ether_dhost,
905 					ETHER_ADDR_LEN);
906 				neg->timeout = 0;
907 				neg->pkt->pkt_header.ph.code = PADR_CODE;
908 				init_tags(sp);
909 				insert_tag(sp, &neg->service.hdr); /* Service */
910 				if ((tag = get_tag(ph, PTT_AC_COOKIE)))
911 					insert_tag(sp, tag); /* return cookie */
912 				if ((tag = get_tag(ph, PTT_AC_NAME)))
913 					insert_tag(sp, tag); /* return it */
914 				insert_tag(sp, utag);      /* Host Unique */
915 				scan_tags(sp, ph);
916 				make_packet(sp);
917 				sp->state = PPPOE_SREQ;
918 				sendpacket(sp);
919 				break;
920 			case	PADR_CODE:
921 
922 				/*
923 				 * We are a server:
924 				 * Use the ac_cookie tag to find the
925 				 * hook this is in response to.
926 				 */
927 				utag = get_tag(ph, PTT_AC_COOKIE);
928 				if ((utag == NULL)
929 				|| (ntohs(utag->tag_len) != sizeof(sp))) {
930 					LEAVE(ENETUNREACH);
931 				}
932 
933 				sendhook = pppoe_finduniq(node, utag);
934 				if (sendhook == NULL) {
935 					LEAVE(ENETUNREACH);
936 				}
937 
938 				/*
939 				 * Check the session is in the right state.
940 				 * It needs to be in PPPOE_SOFFER
941 				 * or PPPOE_NEWCONNECTED. If the latter,
942 				 * then this is a retry by the client.
943 				 * so be nice, and resend.
944 				 */
945 				sp = sendhook->private;
946 				if (sp->state == PPPOE_NEWCONNECTED) {
947 					/*
948 					 * Whoa! drop back to resend that
949 					 * PADS packet.
950 					 * We should still have a copy of it.
951 					 */
952 					sp->state = PPPOE_SOFFER;
953 				}
954 				if (sp->state != PPPOE_SOFFER) {
955 					LEAVE (ENETUNREACH);
956 					break;
957 				}
958 				neg = sp->neg;
959 				untimeout(pppoe_ticker, sendhook,
960 				    neg->timeout_handle);
961 				neg->pkt->pkt_header.ph.code = PADS_CODE;
962 				if (sp->Session_ID == 0)
963 					neg->pkt->pkt_header.ph.sid =
964 					    htons(sp->Session_ID
965 						= get_new_sid(node));
966 				neg->timeout = 0;
967 				/*
968 				 * start working out the tags to respond with.
969 				 */
970 				init_tags(sp);
971 				insert_tag(sp, &neg->ac_name.hdr); /* AC_NAME */
972 				if ((tag = get_tag(ph, PTT_SRV_NAME)))
973 					insert_tag(sp, tag);/* return service */
974 				if ((tag = get_tag(ph, PTT_HOST_UNIQ)))
975 					insert_tag(sp, tag); /* return it */
976 				insert_tag(sp, utag);	/* ac_cookie */
977 				scan_tags(sp, ph);
978 				make_packet(sp);
979 				sp->state = PPPOE_NEWCONNECTED;
980 				sendpacket(sp);
981 				/*
982 				 * Having sent the last Negotiation header,
983 				 * Set up the stored packet header to
984 				 * be correct for the actual session.
985 				 * But keep the negotialtion stuff
986 				 * around in case we need to resend this last
987 				 * packet. We'll discard it when we move
988 				 * from NEWCONNECTED to CONNECTED
989 				 */
990 				sp->pkt_hdr = neg->pkt->pkt_header;
991 				sp->pkt_hdr.eh.ether_type
992 						= ETHERTYPE_PPPOE_SESS;
993 				sp->pkt_hdr.ph.code = 0;
994 				pppoe_send_event(sp, NGM_PPPOE_SUCCESS);
995 				break;
996 			case	PADS_CODE:
997 				/*
998 				 * We are a client:
999 				 * Use the host_uniq tag to find the
1000 				 * hook this is in response to.
1001 				 * take the session ID and store it away.
1002 				 * Also make sure the pre-made header is
1003 				 * correct and set us into Session mode.
1004 				 */
1005 				utag = get_tag(ph, PTT_HOST_UNIQ);
1006 				if ((utag == NULL)
1007 				|| (ntohs(utag->tag_len) != sizeof(sp))) {
1008 					LEAVE (ENETUNREACH);
1009 					break;
1010 				}
1011 				sendhook = pppoe_finduniq(node, utag);
1012 				if (sendhook == NULL) {
1013 					LEAVE(ENETUNREACH);
1014 				}
1015 
1016 				/*
1017 				 * Check the session is in the right state.
1018 				 * It needs to be in PPPOE_SREQ.
1019 				 */
1020 				sp = sendhook->private;
1021 				if (sp->state != PPPOE_SREQ) {
1022 					LEAVE(ENETUNREACH);
1023 				}
1024 				neg = sp->neg;
1025 				untimeout(pppoe_ticker, sendhook,
1026 				    neg->timeout_handle);
1027 				neg->pkt->pkt_header.ph.sid = wh->ph.sid;
1028 				sp->Session_ID = ntohs(wh->ph.sid);
1029 				neg->timeout = 0;
1030 				sp->state = PPPOE_CONNECTED;
1031 				/*
1032 				 * Now we have gone to Connected mode,
1033 				 * Free all resources needed for
1034 				 * negotiation.
1035 				 * Keep a copy of the header we will be using.
1036 				 */
1037 				sp->pkt_hdr = neg->pkt->pkt_header;
1038 				sp->pkt_hdr.eh.ether_type
1039 						= ETHERTYPE_PPPOE_SESS;
1040 				sp->pkt_hdr.ph.code = 0;
1041 				m_freem(neg->m);
1042 				FREE(sp->neg, M_NETGRAPH);
1043 				sp->neg = NULL;
1044 				pppoe_send_event(sp, NGM_PPPOE_SUCCESS);
1045 				break;
1046 			case	PADT_CODE:
1047 				/*
1048 				 * Send a 'close' message to the controlling
1049 				 * process (the one that set us up);
1050 				 * And then tear everything down.
1051 				 *
1052 				 * Find matching peer/session combination.
1053 				 */
1054 				sendhook = pppoe_findsession(node, wh);
1055 				NG_FREE_DATA(m, meta); /* no longer needed */
1056 				if (sendhook == NULL) {
1057 					LEAVE(ENETUNREACH);
1058 				}
1059 				/* send message to creator */
1060 				/* close hook */
1061 				if (sendhook) {
1062 					ng_destroy_hook(sendhook);
1063 				}
1064 				break;
1065 			default:
1066 				LEAVE(EPFNOSUPPORT);
1067 			}
1068 			break;
1069 		case	ETHERTYPE_PPPOE_SESS:
1070 			/*
1071 			 * find matching peer/session combination.
1072 			 */
1073 			sendhook = pppoe_findsession(node, wh);
1074 			if (sendhook == NULL) {
1075 				LEAVE (ENETUNREACH);
1076 				break;
1077 			}
1078 			sp = sendhook->private;
1079 			m_adj(m, sizeof(*wh));
1080 			if (m->m_pkthdr.len < length) {
1081 				/* Packet too short, dump it */
1082 				LEAVE(EMSGSIZE);
1083 			}
1084 
1085 			/* Also need to trim excess at the end */
1086 			if (m->m_pkthdr.len > length) {
1087 				m_adj(m, -((int)(m->m_pkthdr.len - length)));
1088 			}
1089 			if ( sp->state != PPPOE_CONNECTED) {
1090 				if (sp->state == PPPOE_NEWCONNECTED) {
1091 					sp->state = PPPOE_CONNECTED;
1092 					/*
1093 					 * Now we have gone to Connected mode,
1094 					 * Free all resources needed for
1095 					 * negotiation. Be paranoid about
1096 					 * whether there may be a timeout.
1097 					 */
1098 					m_freem(sp->neg->m);
1099 					untimeout(pppoe_ticker, sendhook,
1100 				    		sp->neg->timeout_handle);
1101 					FREE(sp->neg, M_NETGRAPH);
1102 					sp->neg = NULL;
1103 				} else {
1104 					LEAVE (ENETUNREACH);
1105 					break;
1106 				}
1107 			}
1108 			NG_SEND_DATA( error, sendhook, m, meta);
1109 			break;
1110 		default:
1111 			LEAVE(EPFNOSUPPORT);
1112 		}
1113 	} else {
1114 		/*
1115 		 * 	Not ethernet or debug hook..
1116 		 *
1117 		 * The packet has come in on a normal hook.
1118 		 * We need to find out what kind of hook,
1119 		 * So we can decide how to handle it.
1120 		 * Check the hook's state.
1121 		 */
1122 		sp = hook->private;
1123 		switch (sp->state) {
1124 		case	PPPOE_NEWCONNECTED:
1125 		case	PPPOE_CONNECTED: {
1126 			struct pppoe_full_hdr *wh;
1127 			/*
1128 			 * Bang in a pre-made header, and set the length up
1129 			 * to be correct. Then send it to the ethernet driver.
1130 			 * But first correct the length.
1131 			 */
1132 			sp->pkt_hdr.ph.length = htons((short)(m->m_pkthdr.len));
1133 			M_PREPEND(m, sizeof(*wh), M_DONTWAIT);
1134 			if (m == NULL) {
1135 				LEAVE(ENOBUFS);
1136 			}
1137 			wh = mtod(m, struct pppoe_full_hdr *);
1138 			bcopy(&sp->pkt_hdr, wh, sizeof(*wh));
1139 			NG_SEND_DATA( error, privp->ethernet_hook, m, meta);
1140 			privp->packets_out++;
1141 			break;
1142 			}
1143 		case	PPPOE_PRIMED:
1144 			/*
1145 			 * A PADI packet is being returned by the application
1146 			 * that has set up this hook. This indicates that it
1147 			 * wants us to offer service.
1148 			 */
1149 			neg = sp->neg;
1150 			if (m->m_len < sizeof(*wh)) {
1151 				m = m_pullup(m, sizeof(*wh));
1152 				if (m == NULL) {
1153 					LEAVE(ENOBUFS);
1154 				}
1155 			}
1156 			wh = mtod(m, struct pppoe_full_hdr *);
1157 			ph = &wh->ph;
1158 			session = ntohs(wh->ph.sid);
1159 			length = ntohs(wh->ph.length);
1160 			code = wh->ph.code;
1161 			if ( code != PADI_CODE) {
1162 				LEAVE(EINVAL);
1163 			};
1164 			untimeout(pppoe_ticker, hook,
1165 				    neg->timeout_handle);
1166 
1167 			/*
1168 			 * This is the first time we hear
1169 			 * from the client, so note it's
1170 			 * unicast address, replacing the
1171 			 * broadcast address.
1172 			 */
1173 			bcopy(wh->eh.ether_shost,
1174 				neg->pkt->pkt_header.eh.ether_dhost,
1175 				ETHER_ADDR_LEN);
1176 			sp->state = PPPOE_SOFFER;
1177 			neg->timeout = 0;
1178 			neg->pkt->pkt_header.ph.code = PADO_CODE;
1179 
1180 			/*
1181 			 * start working out the tags to respond with.
1182 			 */
1183 			uniqtag.hdr.tag_type = PTT_AC_COOKIE;
1184 			uniqtag.hdr.tag_len = htons((u_int16_t)sizeof(sp));
1185 			uniqtag.data.pointer = sp;
1186 			init_tags(sp);
1187 			insert_tag(sp, &neg->ac_name.hdr); /* AC_NAME */
1188 			if ((tag = get_tag(ph, PTT_SRV_NAME)))
1189 				insert_tag(sp, tag);	  /* return service */
1190 			if ((tag = get_tag(ph, PTT_HOST_UNIQ)))
1191 				insert_tag(sp, tag); /* returned hostunique */
1192 			insert_tag(sp, &uniqtag.hdr);
1193 			/* XXX maybe put the tag in the session store */
1194 			scan_tags(sp, ph);
1195 			make_packet(sp);
1196 			sendpacket(sp);
1197 			break;
1198 
1199 		/*
1200 		 * Packets coming from the hook make no sense
1201 		 * to sessions in these states. Throw them away.
1202 		 */
1203 		case	PPPOE_SINIT:
1204 		case	PPPOE_SREQ:
1205 		case	PPPOE_SOFFER:
1206 		case	PPPOE_SNONE:
1207 		case	PPPOE_LISTENING:
1208 		case	PPPOE_DEAD:
1209 		default:
1210 			LEAVE(ENETUNREACH);
1211 		}
1212 	}
1213 quit:
1214 	NG_FREE_DATA(m, meta);
1215 	return error;
1216 }
1217 
1218 /*
1219  * Do local shutdown processing..
1220  * If we are a persistant device, we might refuse to go away, and
1221  * we'd only remove our links and reset ourself.
1222  */
1223 static int
1224 ng_pppoe_rmnode(node_p node)
1225 {
1226 	const priv_p privdata = node->private;
1227 
1228 AAA
1229 	node->flags |= NG_INVALID;
1230 	ng_cutlinks(node);
1231 	ng_unname(node);
1232 	node->private = NULL;
1233 	ng_unref(privdata->node);
1234 	FREE(privdata, M_NETGRAPH);
1235 	return (0);
1236 }
1237 
1238 /*
1239  * This is called once we've already connected a new hook to the other node.
1240  * It gives us a chance to balk at the last minute.
1241  */
1242 static int
1243 ng_pppoe_connect(hook_p hook)
1244 {
1245 	/* be really amiable and just say "YUP that's OK by me! " */
1246 	return (0);
1247 }
1248 
1249 /*
1250  * Hook disconnection
1251  *
1252  * Clean up all dangling links and information about the session/hook.
1253  * For this type, removal of the last link destroys the node
1254  */
1255 static int
1256 ng_pppoe_disconnect(hook_p hook)
1257 {
1258 	node_p node = hook->node;
1259 	priv_p privp = node->private;
1260 	sessp	sp;
1261 	int 	hooks;
1262 
1263 AAA
1264 	hooks = node->numhooks; /* this one already not counted */
1265 	if (hook->private == &privp->debug_hook) {
1266 		privp->debug_hook = NULL;
1267 	} else if (hook->private == &privp->ethernet_hook) {
1268 		privp->ethernet_hook = NULL;
1269 		ng_rmnode(node);
1270 	} else {
1271 		sp = hook->private;
1272 		if (sp->state != PPPOE_SNONE ) {
1273 			pppoe_send_event(sp, NGM_PPPOE_CLOSE);
1274 		}
1275 		/*
1276 		 * According to the spec, if we are connected,
1277 		 * we should send a DISC packet if we are shutting down
1278 		 * a session.
1279 		 */
1280 		if ((privp->ethernet_hook)
1281 		&& ((sp->state == PPPOE_CONNECTED)
1282 		 || (sp->state == PPPOE_NEWCONNECTED))) {
1283 			struct mbuf *m;
1284 			struct pppoe_full_hdr *wh;
1285 			struct pppoe_tag *tag;
1286 			int	msglen = strlen(SIGNOFF);
1287 			void *dummy = NULL;
1288 			int error = 0;
1289 
1290 			/* revert the stored header to DISC/PADT mode */
1291 		 	wh = &sp->pkt_hdr;
1292 			wh->ph.code = PADT_CODE;
1293 			wh->eh.ether_type = ETHERTYPE_PPPOE_DISC;
1294 
1295 			/* generate a packet of that type */
1296 			MGETHDR(m, M_DONTWAIT, MT_DATA);
1297 			if(m == NULL)
1298 				printf("pppoe: Session out of mbufs\n");
1299 			else {
1300 				m->m_pkthdr.rcvif = NULL;
1301 				m->m_pkthdr.len = m->m_len = sizeof(*wh);
1302 				bcopy((caddr_t)wh, mtod(m, caddr_t),
1303 				    sizeof(*wh));
1304 				/*
1305 				 * Add a General error message and adjust
1306 				 * sizes
1307 				 */
1308 				wh = mtod(m, struct pppoe_full_hdr *);
1309 				tag = wh->ph.tag;
1310 				tag->tag_type = PTT_GEN_ERR;
1311 				tag->tag_len = htons((u_int16_t)msglen);
1312 				strncpy(tag->tag_data, SIGNOFF, msglen);
1313 				m->m_pkthdr.len = (m->m_len += sizeof(*tag) +
1314 				    msglen);
1315 				wh->ph.length = htons(sizeof(*tag) + msglen);
1316 				NG_SEND_DATA(error, privp->ethernet_hook, m,
1317 				    dummy);
1318 			}
1319 		}
1320 		/*
1321 		 * As long as we have somewhere to store the timeout handle,
1322 		 * we may have a timeout pending.. get rid of it.
1323 		 */
1324 		if (sp->neg) {
1325 			untimeout(pppoe_ticker, hook, sp->neg->timeout_handle);
1326 			if (sp->neg->m)
1327 				m_freem(sp->neg->m);
1328 			FREE(sp->neg, M_NETGRAPH);
1329 		}
1330 		FREE(sp, M_NETGRAPH);
1331 		hook->private = NULL;
1332 		/* work out how many session hooks there are */
1333 		/* Node goes away on last session hook removal */
1334 		if (privp->ethernet_hook) hooks -= 1;
1335 		if (privp->debug_hook) hooks -= 1;
1336 	}
1337 	if (node->numhooks == 0)
1338 		ng_rmnode(node);
1339 	return (0);
1340 }
1341 
1342 /*
1343  * timeouts come here.
1344  */
1345 static void
1346 pppoe_ticker(void *arg)
1347 {
1348 	int s = splnet();
1349 	hook_p hook = arg;
1350 	sessp	sp = hook->private;
1351 	negp	neg = sp->neg;
1352 	int	error = 0;
1353 	struct mbuf *m0 = NULL;
1354 	priv_p privp = hook->node->private;
1355 	meta_p dummy = NULL;
1356 
1357 AAA
1358 	switch(sp->state) {
1359 		/*
1360 		 * resend the last packet, using an exponential backoff.
1361 		 * After a period of time, stop growing the backoff,
1362 		 * and either leave it, or revert to the start.
1363 		 */
1364 	case	PPPOE_SINIT:
1365 	case	PPPOE_SREQ:
1366 		/* timeouts on these produce resends */
1367 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1368 		NG_SEND_DATA( error, privp->ethernet_hook, m0, dummy);
1369 		neg->timeout_handle = timeout(pppoe_ticker,
1370 					hook, neg->timeout * hz);
1371 		if ((neg->timeout <<= 1) > PPPOE_TIMEOUT_LIMIT) {
1372 			if (sp->state == PPPOE_SREQ) {
1373 				/* revert to SINIT mode */
1374 				pppoe_start(sp);
1375 			} else {
1376 				neg->timeout = PPPOE_TIMEOUT_LIMIT;
1377 			}
1378 		}
1379 		break;
1380 	case	PPPOE_PRIMED:
1381 	case	PPPOE_SOFFER:
1382 		/* a timeout on these says "give up" */
1383 		ng_destroy_hook(hook);
1384 		break;
1385 	default:
1386 		/* timeouts have no meaning in other states */
1387 		printf("pppoe: unexpected timeout\n");
1388 	}
1389 	splx(s);
1390 }
1391 
1392 
1393 static void
1394 sendpacket(sessp sp)
1395 {
1396 	int	error = 0;
1397 	struct mbuf *m0 = NULL;
1398 	hook_p hook = sp->hook;
1399 	negp	neg = sp->neg;
1400 	priv_p	privp = hook->node->private;
1401 	meta_p dummy = NULL;
1402 
1403 AAA
1404 	switch(sp->state) {
1405 	case	PPPOE_LISTENING:
1406 	case	PPPOE_DEAD:
1407 	case	PPPOE_SNONE:
1408 	case	PPPOE_CONNECTED:
1409 		printf("pppoe: sendpacket: unexpected state\n");
1410 		break;
1411 
1412 	case	PPPOE_NEWCONNECTED:
1413 		/* send the PADS without a timeout - we're now connected */
1414 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1415 		NG_SEND_DATA( error, privp->ethernet_hook, m0, dummy);
1416 		break;
1417 
1418 	case	PPPOE_PRIMED:
1419 		/* No packet to send, but set up the timeout */
1420 		neg->timeout_handle = timeout(pppoe_ticker,
1421 					hook, PPPOE_OFFER_TIMEOUT * hz);
1422 		break;
1423 
1424 	case	PPPOE_SOFFER:
1425 		/*
1426 		 * send the offer but if they don't respond
1427 		 * in PPPOE_OFFER_TIMEOUT seconds, forget about it.
1428 		 */
1429 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1430 		NG_SEND_DATA( error, privp->ethernet_hook, m0, dummy);
1431 		neg->timeout_handle = timeout(pppoe_ticker,
1432 					hook, PPPOE_OFFER_TIMEOUT * hz);
1433 		break;
1434 
1435 	case	PPPOE_SINIT:
1436 	case	PPPOE_SREQ:
1437 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1438 		NG_SEND_DATA( error, privp->ethernet_hook, m0, dummy);
1439 		neg->timeout_handle = timeout(pppoe_ticker, hook,
1440 					(hz * PPPOE_INITIAL_TIMEOUT));
1441 		neg->timeout = PPPOE_INITIAL_TIMEOUT * 2;
1442 		break;
1443 
1444 	default:
1445 		error = EINVAL;
1446 		printf("pppoe: timeout: bad state\n");
1447 	}
1448 	/* return (error); */
1449 }
1450 
1451 /*
1452  * Parse an incoming packet to see if any tags should be copied to the
1453  * output packet. Don't do any tags that have been handled in the main
1454  * state machine.
1455  */
1456 static struct pppoe_tag*
1457 scan_tags(sessp	sp, struct pppoe_hdr* ph)
1458 {
1459 	char *end = (char *)next_tag(ph);
1460 	char *ptn;
1461 	struct pppoe_tag *pt = &ph->tag[0];
1462 	/*
1463 	 * Keep processing tags while a tag header will still fit.
1464 	 */
1465 AAA
1466 	while((char*)(pt + 1) <= end) {
1467 		/*
1468 		 * If the tag data would go past the end of the packet, abort.
1469 		 */
1470 		ptn = (((char *)(pt + 1)) + ntohs(pt->tag_len));
1471 		if(ptn > end)
1472 			return NULL;
1473 
1474 		switch (pt->tag_type) {
1475 		case	PTT_RELAY_SID:
1476 			insert_tag(sp, pt);
1477 			break;
1478 		case	PTT_EOL:
1479 			return NULL;
1480 		case	PTT_SRV_NAME:
1481 		case	PTT_AC_NAME:
1482 		case	PTT_HOST_UNIQ:
1483 		case	PTT_AC_COOKIE:
1484 		case	PTT_VENDOR:
1485 		case	PTT_SRV_ERR:
1486 		case	PTT_SYS_ERR:
1487 		case	PTT_GEN_ERR:
1488 			break;
1489 		}
1490 		pt = (struct pppoe_tag*)ptn;
1491 	}
1492 	return NULL;
1493 }
1494 
1495 static	int
1496 pppoe_send_event(sessp sp, enum cmd cmdid)
1497 {
1498 	int error;
1499 	struct ng_mesg *msg;
1500 	struct ngpppoe_sts *sts;
1501 
1502 AAA
1503 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, cmdid,
1504 			sizeof(struct ngpppoe_sts), M_NOWAIT);
1505 	sts = (struct ngpppoe_sts *)msg->data;
1506 	strncpy(sts->hook, sp->hook->name, NG_HOOKLEN + 1);
1507 	error = ng_send_msg(sp->hook->node, msg, sp->creator, NULL);
1508 	return (error);
1509 }
1510