xref: /dragonfly/sys/netgraph/pppoe/ng_pppoe.c (revision cd1c6085)
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@freebsd.org>
38  *
39  * $FreeBSD: src/sys/netgraph/ng_pppoe.c,v 1.23.2.17 2002/07/02 22:17:18 archie Exp $
40  * $Whistle: ng_pppoe.c,v 1.10 1999/11/01 09:24:52 julian Exp $
41  */
42 #if 0
43 #define AAA kprintf("pppoe: %s\n", __func__ );
44 #define BBB kprintf("-%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 <sys/sysctl.h>
57 #include <sys/syslog.h>
58 #include <sys/thread2.h>
59 
60 #include <net/if_var.h>
61 #include <net/ethernet.h>
62 
63 #include <netgraph/ng_message.h>
64 #include <netgraph/netgraph.h>
65 #include "ng_pppoe.h"
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_rmnode;
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_disconnect_t	ng_pppoe_disconnect;
81 
82 /* Netgraph node type descriptor */
83 static struct ng_type typestruct = {
84 	NG_VERSION,
85 	NG_PPPOE_NODE_TYPE,
86 	NULL,
87 	ng_pppoe_constructor,
88 	ng_pppoe_rcvmsg,
89 	ng_pppoe_rmnode,
90 	ng_pppoe_newhook,
91 	NULL,
92 	ng_pppoe_connect,
93 	ng_pppoe_rcvdata,
94 	ng_pppoe_rcvdata,
95 	ng_pppoe_disconnect,
96 	NULL
97 };
98 NETGRAPH_INIT(pppoe, &typestruct);
99 
100 /*
101  * States for the session state machine.
102  * These have no meaning if there is no hook attached yet.
103  */
104 enum state {
105     PPPOE_SNONE=0,	/* [both] Initial state */
106     PPPOE_LISTENING,	/* [Daemon] Listening for discover initiation pkt */
107     PPPOE_SINIT,	/* [Client] Sent discovery initiation */
108     PPPOE_PRIMED,	/* [Server] Awaiting PADI from daemon */
109     PPPOE_SOFFER,	/* [Server] Sent offer message  (got PADI)*/
110     PPPOE_SREQ,		/* [Client] Sent a Request */
111     PPPOE_NEWCONNECTED,	/* [Server] Connection established, No data received */
112     PPPOE_CONNECTED,	/* [Both] Connection established, Data received */
113     PPPOE_DEAD		/* [Both] */
114 };
115 
116 #define NUMTAGS 20 /* number of tags we are set up to work with */
117 
118 /*
119  * Information we store for each hook on each node for negotiating the
120  * session. The mbuf and cluster are freed once negotiation has completed.
121  * The whole negotiation block is then discarded.
122  */
123 
124 struct sess_neg {
125 	struct mbuf 		*m; /* holds cluster with last sent packet */
126 	union	packet		*pkt; /* points within the above cluster */
127 	struct callout		timeout_ch;
128 	u_int			timeout; /* 0,1,2,4,8,16 etc. seconds */
129 	u_int			numtags;
130 	const struct pppoe_tag	*tags[NUMTAGS];
131 	u_int			service_len;
132 	u_int			ac_name_len;
133 
134 	struct datatag		service;
135 	struct datatag		ac_name;
136 };
137 typedef struct sess_neg *negp;
138 
139 /*
140  * Session information that is needed after connection.
141  */
142 struct sess_con {
143 	hook_p  		hook;
144 	u_int16_t		Session_ID;
145 	enum state		state;
146 	char			creator[NG_NODESIZ]; /* who to notify */
147 	struct pppoe_full_hdr	pkt_hdr;	/* used when connected */
148 	negp			neg;		/* used when negotiating */
149 	/*struct sess_con	*hash_next;*/	/* not yet used */
150 };
151 typedef struct sess_con *sessp;
152 
153 /*
154  * Information we store for each node
155  */
156 struct PPPOE {
157 	node_p		node;		/* back pointer to node */
158 	hook_p  	ethernet_hook;
159 	hook_p  	debug_hook;
160 	u_int   	packets_in;	/* packets in from ethernet */
161 	u_int   	packets_out;	/* packets out towards ethernet */
162 	u_int32_t	flags;
163 	/*struct sess_con *buckets[HASH_SIZE];*/	/* not yet used */
164 };
165 typedef struct PPPOE *priv_p;
166 
167 struct ether_header eh_prototype =
168 	{{0xff,0xff,0xff,0xff,0xff,0xff},
169 	 {0x00,0x00,0x00,0x00,0x00,0x00},
170 	 ETHERTYPE_PPPOE_DISC};
171 
172 #define PPPOE_KEEPSTANDARD	-1	/* never switch to nonstandard mode */
173 #define PPPOE_STANDARD		0	/* try standard mode (dangerous!) */
174 #define PPPOE_NONSTANDARD	1	/* just be in nonstandard mode */
175 static int pppoe_mode = PPPOE_KEEPSTANDARD;
176 
177 static int
178 ngpppoe_set_ethertype(SYSCTL_HANDLER_ARGS)
179 {
180 	int error;
181 	int val;
182 
183 	val = pppoe_mode;
184 	error = sysctl_handle_int(oidp, &val, 0, req);
185 	if (error != 0 || req->newptr == NULL)
186 		return (error);
187 	switch (val) {
188 	case PPPOE_NONSTANDARD:
189 		pppoe_mode = PPPOE_NONSTANDARD;
190 		eh_prototype.ether_type = ETHERTYPE_PPPOE_STUPID_DISC;
191 		break;
192 	case PPPOE_STANDARD:
193 		pppoe_mode = PPPOE_STANDARD;
194 		eh_prototype.ether_type = ETHERTYPE_PPPOE_DISC;
195 		break;
196 	case PPPOE_KEEPSTANDARD:
197 		pppoe_mode = PPPOE_KEEPSTANDARD;
198 		eh_prototype.ether_type = ETHERTYPE_PPPOE_DISC;
199 		break;
200 	default:
201 		return (EINVAL);
202 	}
203 	return (0);
204 }
205 
206 SYSCTL_PROC(_net_graph, OID_AUTO, nonstandard_pppoe, CTLTYPE_INT | CTLFLAG_RW,
207     0, sizeof(int), ngpppoe_set_ethertype, "I", "nonstandard ethertype");
208 
209 union uniq {
210 	char bytes[sizeof(void *)];
211 	void * pointer;
212 	};
213 
214 #define	LEAVE(x) do { error = x; goto quit; } while(0)
215 static void	pppoe_start(sessp sp);
216 static void	sendpacket(sessp sp);
217 static void	pppoe_ticker(void *arg);
218 static const	struct pppoe_tag *scan_tags(sessp sp,
219 			const struct pppoe_hdr* ph);
220 static	int	pppoe_send_event(sessp sp, enum cmd cmdid);
221 
222 /*************************************************************************
223  * Some basic utilities  from the Linux version with author's permission.*
224  * Author:	Michal Ostrowski <mostrows@styx.uwaterloo.ca>		 *
225  ************************************************************************/
226 
227 /*
228  * Generate a new session id
229  * XXX find out the FreeBSD locking scheme.
230  */
231 static u_int16_t
232 get_new_sid(node_p node)
233 {
234 	static int pppoe_sid = 10;
235 	sessp sp;
236 	hook_p	hook;
237 	u_int16_t val;
238 	priv_p privp = node->private;
239 
240 AAA
241 restart:
242 	val = pppoe_sid++;
243 	/*
244 	 * Spec says 0xFFFF is reserved.
245 	 * Also don't use 0x0000
246 	 */
247 	if (val == 0xffff) {
248 		pppoe_sid = 20;
249 		goto restart;
250 	}
251 
252 	/* Check it isn't already in use */
253 	LIST_FOREACH(hook, &node->hooks, hooks) {
254 		/* don't check special hooks */
255 		if ((hook->private == &privp->debug_hook)
256 		||  (hook->private == &privp->ethernet_hook))
257 			continue;
258 		sp = hook->private;
259 		if (sp->Session_ID == val)
260 			goto restart;
261 	}
262 
263 	return val;
264 }
265 
266 
267 /*
268  * Return the location where the next tag can be put
269  */
270 static __inline const struct pppoe_tag*
271 next_tag(const struct pppoe_hdr* ph)
272 {
273 	return (const struct pppoe_tag*)(((const char*)&ph->tag[0])
274 	    + ntohs(ph->length));
275 }
276 
277 /*
278  * Look for a tag of a specific type
279  * Don't trust any length the other end says.
280  * but assume we already sanity checked ph->length.
281  */
282 static const struct pppoe_tag*
283 get_tag(const struct pppoe_hdr* ph, u_int16_t idx)
284 {
285 	const char *const end = (const char *)next_tag(ph);
286 	const char *ptn;
287 	const struct pppoe_tag *pt = &ph->tag[0];
288 	/*
289 	 * Keep processing tags while a tag header will still fit.
290 	 */
291 AAA
292 	while((const char*)(pt + 1) <= end) {
293 	    /*
294 	     * If the tag data would go past the end of the packet, abort.
295 	     */
296 	    ptn = (((const char *)(pt + 1)) + ntohs(pt->tag_len));
297 	    if(ptn > end)
298 		return NULL;
299 
300 	    if(pt->tag_type == idx)
301 		return pt;
302 
303 	    pt = (const struct pppoe_tag*)ptn;
304 	}
305 	return NULL;
306 }
307 
308 /**************************************************************************
309  * inlines to initialise or add tags to a session's tag list,
310  **************************************************************************/
311 /*
312  * Initialise the session's tag list
313  */
314 static void
315 init_tags(sessp sp)
316 {
317 AAA
318 	if(sp->neg == NULL) {
319 		kprintf("pppoe: asked to init NULL neg pointer\n");
320 		return;
321 	}
322 	sp->neg->numtags = 0;
323 }
324 
325 static void
326 insert_tag(sessp sp, const struct pppoe_tag *tp)
327 {
328 	int	i;
329 	negp neg;
330 
331 AAA
332 	if((neg = sp->neg) == NULL) {
333 		kprintf("pppoe: asked to use NULL neg pointer\n");
334 		return;
335 	}
336 	if ((i = neg->numtags++) < NUMTAGS) {
337 		neg->tags[i] = tp;
338 	} else {
339 		kprintf("pppoe: asked to add too many tags to packet\n");
340 		neg->numtags--;
341 	}
342 }
343 
344 /*
345  * Make up a packet, using the tags filled out for the session.
346  *
347  * Assume that the actual pppoe header and ethernet header
348  * are filled out externally to this routine.
349  * Also assume that neg->wh points to the correct
350  * location at the front of the buffer space.
351  */
352 static void
353 make_packet(sessp sp) {
354 	struct pppoe_full_hdr *wh = &sp->neg->pkt->pkt_header;
355 	const struct pppoe_tag **tag;
356 	char *dp;
357 	int count;
358 	int tlen;
359 	u_int16_t length = 0;
360 
361 AAA
362 	if ((sp->neg == NULL) || (sp->neg->m == NULL)) {
363 		kprintf("pppoe: make_packet called from wrong state\n");
364 	}
365 	dp = (char *)wh->ph.tag;
366 	for (count = 0, tag = sp->neg->tags;
367 	    ((count < sp->neg->numtags) && (count < NUMTAGS));
368 	    tag++, count++) {
369 		tlen = ntohs((*tag)->tag_len) + sizeof(**tag);
370 		if ((length + tlen) > (ETHER_MAX_LEN - 4 - sizeof(*wh))) {
371 			kprintf("pppoe: tags too long\n");
372 			sp->neg->numtags = count;
373 			break;	/* XXX chop off what's too long */
374 		}
375 		bcopy(*tag, dp, tlen);
376 		length += tlen;
377 		dp += tlen;
378 	}
379  	wh->ph.length = htons(length);
380 	sp->neg->m->m_len = length + sizeof(*wh);
381 	sp->neg->m->m_pkthdr.len = length + sizeof(*wh);
382 }
383 
384 /**************************************************************************
385  * Routine to match a service offered					  *
386  **************************************************************************/
387 /*
388  * Find a hook that has a service string that matches that
389  * we are seeking. for now use a simple string.
390  * In the future we may need something like regexp().
391  * for testing allow a null string to match 1st found and a null service
392  * to match all requests. Also make '*' do the same.
393  */
394 
395 #define NG_MATCH_EXACT	1
396 #define NG_MATCH_ANY	2
397 
398 static hook_p
399 pppoe_match_svc(node_p node, const char *svc_name, int svc_len, int match)
400 {
401 	sessp	sp	= NULL;
402 	negp	neg	= NULL;
403 	priv_p	privp	= node->private;
404 	hook_p	allhook	= NULL;
405 	hook_p	hook;
406 
407 AAA
408 	LIST_FOREACH(hook, &node->hooks, hooks) {
409 
410 		/* skip any hook that is debug or ethernet */
411 		if ((hook->private == &privp->debug_hook)
412 		||  (hook->private == &privp->ethernet_hook))
413 			continue;
414 		sp = hook->private;
415 
416 		/* Skip any sessions which are not in LISTEN mode. */
417 		if ( sp->state != PPPOE_LISTENING)
418 			continue;
419 
420 		neg = sp->neg;
421 
422 		/* Special case for a blank or "*" service name (wildcard) */
423 		if (match == NG_MATCH_ANY && neg->service_len == 1 &&
424 		    neg->service.data[0] == '*') {
425 			allhook = hook;
426 			continue;
427 		}
428 
429 		/* If the lengths don't match, that aint it. */
430 		if (neg->service_len != svc_len)
431 			continue;
432 
433 		/* An exact match? */
434 		if (svc_len == 0)
435 			break;
436 
437 		if (strncmp(svc_name, neg->service.data, svc_len) == 0)
438 			break;
439 	}
440 	return (hook ? hook : allhook);
441 }
442 /**************************************************************************
443  * Routine to find a particular session that matches an incoming packet	  *
444  **************************************************************************/
445 static hook_p
446 pppoe_findsession(node_p node, const struct pppoe_full_hdr *wh)
447 {
448 	sessp	sp = NULL;
449 	hook_p hook = NULL;
450 	priv_p	privp = node->private;
451 	u_int16_t	session = ntohs(wh->ph.sid);
452 
453 	/*
454 	 * find matching peer/session combination.
455 	 */
456 AAA
457 	LIST_FOREACH(hook, &node->hooks, hooks) {
458 		/* don't check special hooks */
459 		if ((hook->private == &privp->debug_hook)
460 		||  (hook->private == &privp->ethernet_hook)) {
461 			continue;
462 		}
463 		sp = hook->private;
464 		if ( ( (sp->state == PPPOE_CONNECTED)
465 		    || (sp->state == PPPOE_NEWCONNECTED) )
466 		&& (sp->Session_ID == session)
467 		&& (bcmp(sp->pkt_hdr.eh.ether_dhost,
468 		    wh->eh.ether_shost,
469 		    ETHER_ADDR_LEN)) == 0) {
470 			break;
471 		}
472 	}
473 	return (hook);
474 }
475 
476 static hook_p
477 pppoe_finduniq(node_p node, const struct pppoe_tag *tag)
478 {
479 	hook_p hook = NULL;
480 	priv_p	privp = node->private;
481 	union uniq		uniq;
482 
483 AAA
484 	bcopy(tag->tag_data, uniq.bytes, sizeof(void *));
485 	/* cycle through all known hooks */
486 	LIST_FOREACH(hook, &node->hooks, hooks) {
487 		/* don't check special hooks */
488 		if ((hook->private == &privp->debug_hook)
489 		||  (hook->private == &privp->ethernet_hook))
490 			continue;
491 		if (uniq.pointer == hook->private)
492 			break;
493 	}
494 	return (hook);
495 }
496 
497 /**************************************************************************
498  * start of Netgraph entrypoints					  *
499  **************************************************************************/
500 
501 /*
502  * Allocate the private data structure and the generic node
503  * and link them together.
504  *
505  * ng_make_node_common() returns with a generic node struct
506  * with a single reference for us.. we transfer it to the
507  * private structure.. when we free the private struct we must
508  * unref the node so it gets freed too.
509  */
510 static int
511 ng_pppoe_constructor(node_p *nodep)
512 {
513 	priv_p privdata;
514 	int error;
515 
516 AAA
517 	/* Initialize private descriptor */
518 	privdata = kmalloc(sizeof(*privdata), M_NETGRAPH, M_NOWAIT | M_ZERO);
519 	if (privdata == NULL)
520 		return (ENOMEM);
521 
522 	/* Call the 'generic' (ie, superclass) node constructor */
523 	if ((error = ng_make_node_common(&typestruct, nodep))) {
524 		kfree(privdata, M_NETGRAPH);
525 		return (error);
526 	}
527 
528 	/* Link structs together; this counts as our one reference to *nodep */
529 	(*nodep)->private = privdata;
530 	privdata->node = *nodep;
531 	return (0);
532 }
533 
534 /*
535  * Give our ok for a hook to be added...
536  * point the hook's private info to the hook structure.
537  *
538  * The following hook names are special:
539  *  Ethernet:  the hook that should be connected to a NIC.
540  *  debug:	copies of data sent out here  (when I write the code).
541  * All other hook names need only be unique. (the framework checks this).
542  */
543 static int
544 ng_pppoe_newhook(node_p node, hook_p hook, const char *name)
545 {
546 	const priv_p privp = node->private;
547 	sessp sp;
548 
549 AAA
550 	if (strcmp(name, NG_PPPOE_HOOK_ETHERNET) == 0) {
551 		privp->ethernet_hook = hook;
552 		hook->private = &privp->ethernet_hook;
553 	} else if (strcmp(name, NG_PPPOE_HOOK_DEBUG) == 0) {
554 		privp->debug_hook = hook;
555 		hook->private = &privp->debug_hook;
556 	} else {
557 		/*
558 		 * Any other unique name is OK.
559 		 * The infrastructure has already checked that it's unique,
560 		 * so just allocate it and hook it in.
561 		 */
562 		sp = kmalloc(sizeof(*sp), M_NETGRAPH, M_NOWAIT | M_ZERO);
563 		if (sp == NULL)
564 			return (ENOMEM);
565 
566 		hook->private = sp;
567 		sp->hook = hook;
568 	}
569 	return(0);
570 }
571 
572 /*
573  * Get a netgraph control message.
574  * Check it is one we understand. If needed, send a response.
575  * We sometimes save the address for an async action later.
576  * Always free the message.
577  */
578 static int
579 ng_pppoe_rcvmsg(node_p node,
580 	   struct ng_mesg *msg, const char *retaddr, struct ng_mesg **rptr)
581 {
582 	priv_p privp = node->private;
583 	struct ngpppoe_init_data *ourmsg = NULL;
584 	struct ng_mesg *resp = NULL;
585 	int error = 0;
586 	hook_p hook = NULL;
587 	sessp sp = NULL;
588 	negp neg = NULL;
589 
590 AAA
591 	/* Deal with message according to cookie and command */
592 	switch (msg->header.typecookie) {
593 	case NGM_PPPOE_COOKIE:
594 		switch (msg->header.cmd) {
595 		case NGM_PPPOE_CONNECT:
596 		case NGM_PPPOE_LISTEN:
597 		case NGM_PPPOE_OFFER:
598 		case NGM_PPPOE_SERVICE:
599 			ourmsg = (struct ngpppoe_init_data *)msg->data;
600 			if (( sizeof(*ourmsg) > msg->header.arglen)
601 			|| ((sizeof(*ourmsg) + ourmsg->data_len)
602 			    > msg->header.arglen)) {
603 				kprintf("pppoe_rcvmsg: bad arg size");
604 				LEAVE(EMSGSIZE);
605 			}
606 			if (ourmsg->data_len > PPPOE_SERVICE_NAME_SIZE) {
607 				kprintf("pppoe: init data too long (%d)\n",
608 							ourmsg->data_len);
609 				LEAVE(EMSGSIZE);
610 			}
611 			/* make sure strcmp will terminate safely */
612 			ourmsg->hook[sizeof(ourmsg->hook) - 1] = '\0';
613 
614 			/* cycle through all known hooks */
615 			LIST_FOREACH(hook, &node->hooks, hooks) {
616 				if (hook->name
617 				&& strcmp(hook->name, ourmsg->hook) == 0)
618 					break;
619 			}
620 			if (hook == NULL) {
621 				LEAVE(ENOENT);
622 			}
623 			if ((hook->private == &privp->debug_hook)
624 			||  (hook->private == &privp->ethernet_hook)) {
625 				LEAVE(EINVAL);
626 			}
627 			sp = hook->private;
628 
629 			if (msg->header.cmd == NGM_PPPOE_LISTEN) {
630 				/*
631 				 * Ensure we aren't already listening for this
632 				 * service.
633 				 */
634 				if (pppoe_match_svc(node, ourmsg->data,
635 				    ourmsg->data_len, NG_MATCH_EXACT) != NULL) {
636 					LEAVE(EEXIST);
637 				}
638 			}
639 
640 			/*
641 			 * PPPOE_SERVICE advertisments are set up
642 			 * on sessions that are in PRIMED state.
643 			 */
644 			if (msg->header.cmd == NGM_PPPOE_SERVICE) {
645 				break;
646 			}
647 			if (sp->state != PPPOE_SNONE) {
648 				kprintf("pppoe: Session already active\n");
649 				LEAVE(EISCONN);
650 			}
651 
652 			/*
653 			 * set up prototype header
654 			 */
655 			neg = kmalloc(sizeof(*neg), M_NETGRAPH,
656 				      M_NOWAIT | M_ZERO);
657 
658 			if (neg == NULL) {
659 				kprintf("pppoe: Session out of memory\n");
660 				LEAVE(ENOMEM);
661 			}
662 			MGETHDR(neg->m, M_NOWAIT, MT_DATA);
663 			if(neg->m == NULL) {
664 				kprintf("pppoe: Session out of mbufs\n");
665 				kfree(neg, M_NETGRAPH);
666 				LEAVE(ENOBUFS);
667 			}
668 			neg->m->m_pkthdr.rcvif = NULL;
669 			MCLGET(neg->m, M_NOWAIT);
670 			if ((neg->m->m_flags & M_EXT) == 0) {
671 				kprintf("pppoe: Session out of mcls\n");
672 				m_freem(neg->m);
673 				kfree(neg, M_NETGRAPH);
674 				LEAVE(ENOBUFS);
675 			}
676 			sp->neg = neg;
677 			callout_init(&neg->timeout_ch);
678 			neg->m->m_len = sizeof(struct pppoe_full_hdr);
679 			neg->pkt = mtod(neg->m, union packet*);
680 			neg->pkt->pkt_header.eh = eh_prototype;
681 			neg->pkt->pkt_header.ph.ver = 0x1;
682 			neg->pkt->pkt_header.ph.type = 0x1;
683 			neg->pkt->pkt_header.ph.sid = 0x0000;
684 			neg->timeout = 0;
685 
686 			strlcpy(sp->creator, retaddr, NG_NODESIZ);
687 		}
688 		switch (msg->header.cmd) {
689 		case NGM_PPPOE_GET_STATUS:
690 		    {
691 			struct ngpppoestat *stats;
692 
693 			NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT);
694 			if (!resp) {
695 				LEAVE(ENOMEM);
696 			}
697 			stats = (struct ngpppoestat *) resp->data;
698 			stats->packets_in = privp->packets_in;
699 			stats->packets_out = privp->packets_out;
700 			break;
701 		    }
702 		case NGM_PPPOE_CONNECT:
703 			/*
704 			 * Check the hook exists and is Uninitialised.
705 			 * Send a PADI request, and start the timeout logic.
706 			 * Store the originator of this message so we can send
707 			 * a success of fail message to them later.
708 			 * Move the session to SINIT
709 			 * Set up the session to the correct state and
710 			 * start it.
711 			 */
712 			neg->service.hdr.tag_type = PTT_SRV_NAME;
713 			neg->service.hdr.tag_len =
714 					htons((u_int16_t)ourmsg->data_len);
715 			if (ourmsg->data_len) {
716 				bcopy(ourmsg->data,
717 					neg->service.data, ourmsg->data_len);
718 			}
719 			neg->service_len = ourmsg->data_len;
720 			pppoe_start(sp);
721 			break;
722 		case NGM_PPPOE_LISTEN:
723 			/*
724 			 * Check the hook exists and is Uninitialised.
725 			 * Install the service matching string.
726 			 * Store the originator of this message so we can send
727 			 * a success of fail message to them later.
728 			 * Move the hook to 'LISTENING'
729 			 */
730 			neg->service.hdr.tag_type = PTT_SRV_NAME;
731 			neg->service.hdr.tag_len =
732 					htons((u_int16_t)ourmsg->data_len);
733 
734 			if (ourmsg->data_len) {
735 				bcopy(ourmsg->data,
736 					neg->service.data, ourmsg->data_len);
737 			}
738 			neg->service_len = ourmsg->data_len;
739 			neg->pkt->pkt_header.ph.code = PADT_CODE;
740 			/*
741 			 * wait for PADI packet coming from ethernet
742 			 */
743 			sp->state = PPPOE_LISTENING;
744 			break;
745 		case NGM_PPPOE_OFFER:
746 			/*
747 			 * Check the hook exists and is Uninitialised.
748 			 * Store the originator of this message so we can send
749 			 * a success of fail message to them later.
750 			 * Store the AC-Name given and go to PRIMED.
751 			 */
752 			neg->ac_name.hdr.tag_type = PTT_AC_NAME;
753 			neg->ac_name.hdr.tag_len =
754 					htons((u_int16_t)ourmsg->data_len);
755 			if (ourmsg->data_len) {
756 				bcopy(ourmsg->data,
757 					neg->ac_name.data, ourmsg->data_len);
758 			}
759 			neg->ac_name_len = ourmsg->data_len;
760 			neg->pkt->pkt_header.ph.code = PADO_CODE;
761 			/*
762 			 * Wait for PADI packet coming from hook
763 			 */
764 			sp->state = PPPOE_PRIMED;
765 			break;
766 		case NGM_PPPOE_SERVICE:
767 			/*
768 			 * Check the session is primed.
769 			 * for now just allow ONE service to be advertised.
770 			 * If you do it twice you just overwrite.
771 			 */
772 			if (sp->state != PPPOE_PRIMED) {
773 				kprintf("pppoe: Session not primed\n");
774 				LEAVE(EISCONN);
775 			}
776 			neg = sp->neg;
777 			neg->service.hdr.tag_type = PTT_SRV_NAME;
778 			neg->service.hdr.tag_len =
779 			    htons((u_int16_t)ourmsg->data_len);
780 
781 			if (ourmsg->data_len)
782 				bcopy(ourmsg->data, neg->service.data,
783 				    ourmsg->data_len);
784 			neg->service_len = ourmsg->data_len;
785 			break;
786 		default:
787 			LEAVE(EINVAL);
788 		}
789 		break;
790 	default:
791 		LEAVE(EINVAL);
792 	}
793 
794 	/* Take care of synchronous response, if any */
795 	if (rptr)
796 		*rptr = resp;
797 	else if (resp)
798 		kfree(resp, M_NETGRAPH);
799 
800 	/* Free the message and return */
801 quit:
802 	kfree(msg, M_NETGRAPH);
803 	return(error);
804 }
805 
806 /*
807  * Start a client into the first state. A separate function because
808  * it can be needed if the negotiation times out.
809  */
810 static void
811 pppoe_start(sessp sp)
812 {
813 	struct {
814 		struct pppoe_tag hdr;
815 		union	uniq	data;
816 	} __attribute ((packed)) uniqtag;
817 
818 	/*
819 	 * kick the state machine into starting up
820 	 */
821 AAA
822 	sp->state = PPPOE_SINIT;
823 	/* reset the packet header to broadcast */
824 	sp->neg->pkt->pkt_header.eh = eh_prototype;
825 	sp->neg->pkt->pkt_header.ph.code = PADI_CODE;
826 	uniqtag.hdr.tag_type = PTT_HOST_UNIQ;
827 	uniqtag.hdr.tag_len = htons((u_int16_t)sizeof(uniqtag.data));
828 	uniqtag.data.pointer = sp;
829 	init_tags(sp);
830 	insert_tag(sp, &uniqtag.hdr);
831 	insert_tag(sp, &sp->neg->service.hdr);
832 	make_packet(sp);
833 	sendpacket(sp);
834 }
835 
836 static int
837 send_acname(sessp sp, const struct pppoe_tag *tag)
838 {
839 	int error, tlen;
840 	struct ng_mesg *msg;
841 	struct ngpppoe_sts *sts;
842 
843 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_ACNAME,
844 	    sizeof(struct ngpppoe_sts), M_NOWAIT);
845 	if (msg == NULL)
846 		return (ENOMEM);
847 
848 	sts = (struct ngpppoe_sts *)msg->data;
849 	tlen = min(NG_HOOKSIZ - 1, ntohs(tag->tag_len));
850 	strncpy(sts->hook, tag->tag_data, tlen);
851 	sts->hook[tlen] = '\0';
852 	error = ng_send_msg(sp->hook->node, msg, sp->creator, NULL);
853 
854 	return (error);
855 }
856 
857 static int
858 send_sessionid(sessp sp)
859 {
860 	int error;
861 	struct ng_mesg *msg;
862 
863 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_SESSIONID,
864 	    sizeof(u_int16_t), M_NOWAIT);
865 	if (msg == NULL)
866 		return (ENOMEM);
867 
868 	*(u_int16_t *)msg->data = sp->Session_ID;
869 	error = ng_send_msg(sp->hook->node, msg, sp->creator, NULL);
870 
871 	return (error);
872 }
873 
874 /*
875  * Receive data, and do something with it.
876  * The caller will never free m or meta, so
877  * if we use up this data or abort we must free BOTH of these.
878  */
879 static int
880 ng_pppoe_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
881 {
882 	node_p			node = hook->node;
883 	const priv_p		privp = node->private;
884 	sessp			sp = hook->private;
885 	const struct pppoe_full_hdr *wh;
886 	const struct pppoe_hdr	*ph;
887 	int			error = 0;
888 	u_int16_t		length;
889 	u_int8_t		code;
890 	const struct pppoe_tag	*utag = NULL, *tag = NULL;
891 	hook_p 			sendhook;
892 	struct {
893 		struct pppoe_tag hdr;
894 		union	uniq	data;
895 	} __attribute ((packed)) uniqtag;
896 	negp			neg = NULL;
897 	char ethstr[ETHER_ADDRSTRLEN + 1];
898 
899 AAA
900 	if (hook->private == &privp->debug_hook) {
901 		/*
902 		 * Data from the debug hook gets sent without modification
903 		 * straight to the ethernet.
904 		 */
905 		NG_SEND_DATA( error, privp->ethernet_hook, m, meta);
906 	 	privp->packets_out++;
907 	} else if (hook->private == &privp->ethernet_hook) {
908 		/*
909 		 * Incoming data.
910 		 * Dig out various fields from the packet.
911 		 * use them to decide where to send it.
912 		 */
913 
914  		privp->packets_in++;
915 		if( m->m_len < sizeof(*wh)) {
916 			m = m_pullup(m, sizeof(*wh)); /* Checks length */
917 			if (m == NULL) {
918 				kprintf("couldn't m_pullup\n");
919 				LEAVE(ENOBUFS);
920 			}
921 		}
922 		wh = mtod(m, struct pppoe_full_hdr *);
923 		ph = &wh->ph;
924 		length = ntohs(wh->ph.length);
925 		code = wh->ph.code;
926 		switch(wh->eh.ether_type) {
927 		case	ETHERTYPE_PPPOE_STUPID_DISC:
928 			if (pppoe_mode == PPPOE_STANDARD) {
929 				pppoe_mode = PPPOE_NONSTANDARD;
930 				eh_prototype.ether_type =
931 				    ETHERTYPE_PPPOE_STUPID_DISC;
932 				log(LOG_NOTICE,
933 				    "Switched to nonstandard PPPoE mode due to "
934 				    "packet from %s\n",
935 				    kether_ntoa(wh->eh.ether_shost, ethstr));
936 			} else if (pppoe_mode == PPPOE_KEEPSTANDARD)
937 				log(LOG_NOTICE,
938 				    "Ignored nonstandard PPPoE packet "
939 				    "from %s\n",
940 				    kether_ntoa(wh->eh.ether_shost, ethstr));
941 			/* fall through */
942 		case	ETHERTYPE_PPPOE_DISC:
943 			/*
944 			 * We need to try to make sure that the tag area
945 			 * is contiguous, or we could wander off the end
946 			 * of a buffer and make a mess.
947 			 * (Linux wouldn't have this problem).
948 			 */
949 /*XXX fix this mess */
950 
951 			if (m->m_pkthdr.len <= MHLEN) {
952 				if( m->m_len < m->m_pkthdr.len) {
953 					m = m_pullup(m, m->m_pkthdr.len);
954 					if (m == NULL) {
955 						kprintf("couldn't m_pullup\n");
956 						LEAVE(ENOBUFS);
957 					}
958 				}
959 			}
960 			if (m->m_len != m->m_pkthdr.len) {
961 				/*
962 				 * It's not all in one piece.
963 				 * We need to do extra work.
964 				 */
965 				kprintf("packet fragmented\n");
966 				LEAVE(EMSGSIZE);
967 			}
968 
969 			switch(code) {
970 			case	PADI_CODE:
971 				/*
972 				 * We are a server:
973 				 * Look for a hook with the required service
974 				 * and send the ENTIRE packet up there.
975 				 * It should come back to a new hook in
976 				 * PRIMED state. Look there for further
977 				 * processing.
978 				 */
979 				tag = get_tag(ph, PTT_SRV_NAME);
980 				if (tag == NULL) {
981 					kprintf("no service tag\n");
982 					LEAVE(ENETUNREACH);
983 				}
984 				sendhook = pppoe_match_svc(hook->node,
985 			    		tag->tag_data, ntohs(tag->tag_len),
986 					NG_MATCH_ANY);
987 				if (sendhook) {
988 					NG_SEND_DATA(error, sendhook, m, meta);
989 				} else {
990 					LEAVE(ENETUNREACH);
991 				}
992 				break;
993 			case	PADO_CODE:
994 				/*
995 				 * We are a client:
996 				 * Use the host_uniq tag to find the
997 				 * hook this is in response to.
998 				 * Received #2, now send #3
999 				 * For now simply accept the first we receive.
1000 				 */
1001 				utag = get_tag(ph, PTT_HOST_UNIQ);
1002 				if ((utag == NULL)
1003 				|| (ntohs(utag->tag_len) != sizeof(sp))) {
1004 					kprintf("no host unique field\n");
1005 					LEAVE(ENETUNREACH);
1006 				}
1007 
1008 				sendhook = pppoe_finduniq(node, utag);
1009 				if (sendhook == NULL) {
1010 					kprintf("no matching session\n");
1011 					LEAVE(ENETUNREACH);
1012 				}
1013 
1014 				/*
1015 				 * Check the session is in the right state.
1016 				 * It needs to be in PPPOE_SINIT.
1017 				 */
1018 				sp = sendhook->private;
1019 				if (sp->state != PPPOE_SINIT) {
1020 					kprintf("session in wrong state\n");
1021 					LEAVE(ENETUNREACH);
1022 				}
1023 				neg = sp->neg;
1024 				callout_stop(&neg->timeout_ch);
1025 
1026 				/*
1027 				 * This is the first time we hear
1028 				 * from the server, so note it's
1029 				 * unicast address, replacing the
1030 				 * broadcast address .
1031 				 */
1032 				bcopy(wh->eh.ether_shost,
1033 					neg->pkt->pkt_header.eh.ether_dhost,
1034 					ETHER_ADDR_LEN);
1035 				neg->timeout = 0;
1036 				neg->pkt->pkt_header.ph.code = PADR_CODE;
1037 				init_tags(sp);
1038 				insert_tag(sp, utag);      /* Host Unique */
1039 				if ((tag = get_tag(ph, PTT_AC_COOKIE)))
1040 					insert_tag(sp, tag); /* return cookie */
1041 				if ((tag = get_tag(ph, PTT_AC_NAME))) {
1042 					insert_tag(sp, tag); /* return it */
1043 					send_acname(sp, tag);
1044 				}
1045 				insert_tag(sp, &neg->service.hdr); /* Service */
1046 				scan_tags(sp, ph);
1047 				make_packet(sp);
1048 				sp->state = PPPOE_SREQ;
1049 				sendpacket(sp);
1050 				break;
1051 			case	PADR_CODE:
1052 
1053 				/*
1054 				 * We are a server:
1055 				 * Use the ac_cookie tag to find the
1056 				 * hook this is in response to.
1057 				 */
1058 				utag = get_tag(ph, PTT_AC_COOKIE);
1059 				if ((utag == NULL)
1060 				|| (ntohs(utag->tag_len) != sizeof(sp))) {
1061 					LEAVE(ENETUNREACH);
1062 				}
1063 
1064 				sendhook = pppoe_finduniq(node, utag);
1065 				if (sendhook == NULL) {
1066 					LEAVE(ENETUNREACH);
1067 				}
1068 
1069 				/*
1070 				 * Check the session is in the right state.
1071 				 * It needs to be in PPPOE_SOFFER
1072 				 * or PPPOE_NEWCONNECTED. If the latter,
1073 				 * then this is a retry by the client.
1074 				 * so be nice, and resend.
1075 				 */
1076 				sp = sendhook->private;
1077 				if (sp->state == PPPOE_NEWCONNECTED) {
1078 					/*
1079 					 * Whoa! drop back to resend that
1080 					 * PADS packet.
1081 					 * We should still have a copy of it.
1082 					 */
1083 					sp->state = PPPOE_SOFFER;
1084 				}
1085 				if (sp->state != PPPOE_SOFFER) {
1086 					LEAVE (ENETUNREACH);
1087 					break;
1088 				}
1089 				neg = sp->neg;
1090 				callout_stop(&neg->timeout_ch);
1091 				neg->pkt->pkt_header.ph.code = PADS_CODE;
1092 				if (sp->Session_ID == 0)
1093 					neg->pkt->pkt_header.ph.sid =
1094 					    htons(sp->Session_ID
1095 						= get_new_sid(node));
1096 				send_sessionid(sp);
1097 				neg->timeout = 0;
1098 				/*
1099 				 * start working out the tags to respond with.
1100 				 */
1101 				init_tags(sp);
1102 				insert_tag(sp, &neg->ac_name.hdr); /* AC_NAME */
1103 				if ((tag = get_tag(ph, PTT_SRV_NAME)))
1104 					insert_tag(sp, tag);/* return service */
1105 				if ((tag = get_tag(ph, PTT_HOST_UNIQ)))
1106 					insert_tag(sp, tag); /* return it */
1107 				insert_tag(sp, utag);	/* ac_cookie */
1108 				scan_tags(sp, ph);
1109 				make_packet(sp);
1110 				sp->state = PPPOE_NEWCONNECTED;
1111 				sendpacket(sp);
1112 				/*
1113 				 * Having sent the last Negotiation header,
1114 				 * Set up the stored packet header to
1115 				 * be correct for the actual session.
1116 				 * But keep the negotialtion stuff
1117 				 * around in case we need to resend this last
1118 				 * packet. We'll discard it when we move
1119 				 * from NEWCONNECTED to CONNECTED
1120 				 */
1121 				sp->pkt_hdr = neg->pkt->pkt_header;
1122 				if (pppoe_mode == PPPOE_NONSTANDARD)
1123 					sp->pkt_hdr.eh.ether_type
1124 						= ETHERTYPE_PPPOE_STUPID_SESS;
1125 				else
1126 					sp->pkt_hdr.eh.ether_type
1127 						= ETHERTYPE_PPPOE_SESS;
1128 				sp->pkt_hdr.ph.code = 0;
1129 				pppoe_send_event(sp, NGM_PPPOE_SUCCESS);
1130 				break;
1131 			case	PADS_CODE:
1132 				/*
1133 				 * We are a client:
1134 				 * Use the host_uniq tag to find the
1135 				 * hook this is in response to.
1136 				 * take the session ID and store it away.
1137 				 * Also make sure the pre-made header is
1138 				 * correct and set us into Session mode.
1139 				 */
1140 				utag = get_tag(ph, PTT_HOST_UNIQ);
1141 				if ((utag == NULL)
1142 				|| (ntohs(utag->tag_len) != sizeof(sp))) {
1143 					LEAVE (ENETUNREACH);
1144 					break;
1145 				}
1146 				sendhook = pppoe_finduniq(node, utag);
1147 				if (sendhook == NULL) {
1148 					LEAVE(ENETUNREACH);
1149 				}
1150 
1151 				/*
1152 				 * Check the session is in the right state.
1153 				 * It needs to be in PPPOE_SREQ.
1154 				 */
1155 				sp = sendhook->private;
1156 				if (sp->state != PPPOE_SREQ) {
1157 					LEAVE(ENETUNREACH);
1158 				}
1159 				neg = sp->neg;
1160 				callout_stop(&neg->timeout_ch);
1161 				neg->pkt->pkt_header.ph.sid = wh->ph.sid;
1162 				sp->Session_ID = ntohs(wh->ph.sid);
1163 				send_sessionid(sp);
1164 				neg->timeout = 0;
1165 				sp->state = PPPOE_CONNECTED;
1166 				/*
1167 				 * Now we have gone to Connected mode,
1168 				 * Free all resources needed for
1169 				 * negotiation.
1170 				 * Keep a copy of the header we will be using.
1171 				 */
1172 				sp->pkt_hdr = neg->pkt->pkt_header;
1173 				if (pppoe_mode == PPPOE_NONSTANDARD)
1174 					sp->pkt_hdr.eh.ether_type
1175 						= ETHERTYPE_PPPOE_STUPID_SESS;
1176 				else
1177 					sp->pkt_hdr.eh.ether_type
1178 						= ETHERTYPE_PPPOE_SESS;
1179 				sp->pkt_hdr.ph.code = 0;
1180 				m_freem(neg->m);
1181 				kfree(sp->neg, M_NETGRAPH);
1182 				sp->neg = NULL;
1183 				pppoe_send_event(sp, NGM_PPPOE_SUCCESS);
1184 				break;
1185 			case	PADT_CODE:
1186 				/*
1187 				 * Send a 'close' message to the controlling
1188 				 * process (the one that set us up);
1189 				 * And then tear everything down.
1190 				 *
1191 				 * Find matching peer/session combination.
1192 				 */
1193 				sendhook = pppoe_findsession(node, wh);
1194 				NG_FREE_DATA(m, meta); /* no longer needed */
1195 				if (sendhook == NULL) {
1196 					LEAVE(ENETUNREACH);
1197 				}
1198 				/* send message to creator */
1199 				/* close hook */
1200 				if (sendhook) {
1201 					ng_destroy_hook(sendhook);
1202 				}
1203 				break;
1204 			default:
1205 				LEAVE(EPFNOSUPPORT);
1206 			}
1207 			break;
1208 		case	ETHERTYPE_PPPOE_STUPID_SESS:
1209 		case	ETHERTYPE_PPPOE_SESS:
1210 			/*
1211 			 * find matching peer/session combination.
1212 			 */
1213 			sendhook = pppoe_findsession(node, wh);
1214 			if (sendhook == NULL) {
1215 				LEAVE (ENETUNREACH);
1216 				break;
1217 			}
1218 			sp = sendhook->private;
1219 			m_adj(m, sizeof(*wh));
1220 			if (m->m_pkthdr.len < length) {
1221 				/* Packet too short, dump it */
1222 				LEAVE(EMSGSIZE);
1223 			}
1224 
1225 			/* Also need to trim excess at the end */
1226 			if (m->m_pkthdr.len > length) {
1227 				m_adj(m, -((int)(m->m_pkthdr.len - length)));
1228 			}
1229 			if ( sp->state != PPPOE_CONNECTED) {
1230 				if (sp->state == PPPOE_NEWCONNECTED) {
1231 					sp->state = PPPOE_CONNECTED;
1232 					/*
1233 					 * Now we have gone to Connected mode,
1234 					 * Free all resources needed for
1235 					 * negotiation. Be paranoid about
1236 					 * whether there may be a timeout.
1237 					 */
1238 					m_freem(sp->neg->m);
1239 					callout_stop(&sp->neg->timeout_ch);
1240 					kfree(sp->neg, M_NETGRAPH);
1241 					sp->neg = NULL;
1242 				} else {
1243 					LEAVE (ENETUNREACH);
1244 					break;
1245 				}
1246 			}
1247 			NG_SEND_DATA( error, sendhook, m, meta);
1248 			break;
1249 		default:
1250 			LEAVE(EPFNOSUPPORT);
1251 		}
1252 	} else {
1253 		/*
1254 		 * 	Not ethernet or debug hook..
1255 		 *
1256 		 * The packet has come in on a normal hook.
1257 		 * We need to find out what kind of hook,
1258 		 * So we can decide how to handle it.
1259 		 * Check the hook's state.
1260 		 */
1261 		sp = hook->private;
1262 		switch (sp->state) {
1263 		case	PPPOE_NEWCONNECTED:
1264 		case	PPPOE_CONNECTED: {
1265 			static const u_char addrctrl[] = { 0xff, 0x03 };
1266 			struct pppoe_full_hdr *wh;
1267 
1268 			/*
1269 			 * Remove PPP address and control fields, if any.
1270 			 * For example, ng_ppp(4) always sends LCP packets
1271 			 * with address and control fields as required by
1272 			 * generic PPP. PPPoE is an exception to the rule.
1273 			 */
1274 			if (m->m_pkthdr.len >= 2) {
1275 				if (m->m_len < 2 && !(m = m_pullup(m, 2)))
1276 					LEAVE(ENOBUFS);
1277 				if (bcmp(mtod(m, u_char *), addrctrl, 2) == 0)
1278 					m_adj(m, 2);
1279 			}
1280 			/*
1281 			 * Bang in a pre-made header, and set the length up
1282 			 * to be correct. Then send it to the ethernet driver.
1283 			 * But first correct the length.
1284 			 */
1285 			sp->pkt_hdr.ph.length = htons((short)(m->m_pkthdr.len));
1286 			M_PREPEND(m, sizeof(*wh), M_NOWAIT);
1287 			if (m == NULL) {
1288 				LEAVE(ENOBUFS);
1289 			}
1290 			wh = mtod(m, struct pppoe_full_hdr *);
1291 			bcopy(&sp->pkt_hdr, wh, sizeof(*wh));
1292 			NG_SEND_DATA( error, privp->ethernet_hook, m, meta);
1293 			privp->packets_out++;
1294 			break;
1295 			}
1296 		case	PPPOE_PRIMED:
1297 			/*
1298 			 * A PADI packet is being returned by the application
1299 			 * that has set up this hook. This indicates that it
1300 			 * wants us to offer service.
1301 			 */
1302 			neg = sp->neg;
1303 			if (m->m_len < sizeof(*wh)) {
1304 				m = m_pullup(m, sizeof(*wh));
1305 				if (m == NULL) {
1306 					LEAVE(ENOBUFS);
1307 				}
1308 			}
1309 			wh = mtod(m, struct pppoe_full_hdr *);
1310 			ph = &wh->ph;
1311 			length = ntohs(wh->ph.length);
1312 			code = wh->ph.code;
1313 			if ( code != PADI_CODE) {
1314 				LEAVE(EINVAL);
1315 			}
1316 			callout_stop(&neg->timeout_ch);
1317 
1318 			/*
1319 			 * This is the first time we hear
1320 			 * from the client, so note it's
1321 			 * unicast address, replacing the
1322 			 * broadcast address.
1323 			 */
1324 			bcopy(wh->eh.ether_shost,
1325 				neg->pkt->pkt_header.eh.ether_dhost,
1326 				ETHER_ADDR_LEN);
1327 			sp->state = PPPOE_SOFFER;
1328 			neg->timeout = 0;
1329 			neg->pkt->pkt_header.ph.code = PADO_CODE;
1330 
1331 			/*
1332 			 * start working out the tags to respond with.
1333 			 */
1334 			uniqtag.hdr.tag_type = PTT_AC_COOKIE;
1335 			uniqtag.hdr.tag_len = htons((u_int16_t)sizeof(sp));
1336 			uniqtag.data.pointer = sp;
1337 			init_tags(sp);
1338 			insert_tag(sp, &neg->ac_name.hdr); /* AC_NAME */
1339 			if ((tag = get_tag(ph, PTT_SRV_NAME)))
1340 				insert_tag(sp, tag);	  /* return service */
1341 			/*
1342 			 * If we have a NULL service request
1343 			 * and have an extra service defined in this hook,
1344 			 * then also add a tag for the extra service.
1345 			 * XXX this is a hack. eventually we should be able
1346 			 * to support advertising many services, not just one
1347 			 */
1348 			if (((tag == NULL) || (tag->tag_len == 0))
1349 			&& (neg->service.hdr.tag_len != 0)) {
1350 				insert_tag(sp, &neg->service.hdr); /* SERVICE */
1351 			}
1352 			if ((tag = get_tag(ph, PTT_HOST_UNIQ)))
1353 				insert_tag(sp, tag); /* returned hostunique */
1354 			insert_tag(sp, &uniqtag.hdr);
1355 			scan_tags(sp, ph);
1356 			make_packet(sp);
1357 			sendpacket(sp);
1358 			break;
1359 
1360 		/*
1361 		 * Packets coming from the hook make no sense
1362 		 * to sessions in these states. Throw them away.
1363 		 */
1364 		case	PPPOE_SINIT:
1365 		case	PPPOE_SREQ:
1366 		case	PPPOE_SOFFER:
1367 		case	PPPOE_SNONE:
1368 		case	PPPOE_LISTENING:
1369 		case	PPPOE_DEAD:
1370 		default:
1371 			LEAVE(ENETUNREACH);
1372 		}
1373 	}
1374 quit:
1375 	NG_FREE_DATA(m, meta);
1376 	return error;
1377 }
1378 
1379 /*
1380  * Do local shutdown processing..
1381  * If we are a persistant device, we might refuse to go away, and
1382  * we'd only remove our links and reset ourself.
1383  */
1384 static int
1385 ng_pppoe_rmnode(node_p node)
1386 {
1387 	const priv_p privdata = node->private;
1388 
1389 AAA
1390 	node->flags |= NG_INVALID;
1391 	ng_cutlinks(node);
1392 	ng_unname(node);
1393 	node->private = NULL;
1394 	ng_unref(privdata->node);
1395 	kfree(privdata, M_NETGRAPH);
1396 	return (0);
1397 }
1398 
1399 /*
1400  * This is called once we've already connected a new hook to the other node.
1401  * It gives us a chance to balk at the last minute.
1402  */
1403 static int
1404 ng_pppoe_connect(hook_p hook)
1405 {
1406 	/* be really amiable and just say "YUP that's OK by me! " */
1407 	return (0);
1408 }
1409 
1410 /*
1411  * Hook disconnection
1412  *
1413  * Clean up all dangling links and information about the session/hook.
1414  * For this type, removal of the last link destroys the node
1415  */
1416 static int
1417 ng_pppoe_disconnect(hook_p hook)
1418 {
1419 	node_p node = hook->node;
1420 	priv_p privp = node->private;
1421 	sessp	sp;
1422 	int 	hooks;
1423 
1424 AAA
1425 	hooks = node->numhooks; /* this one already not counted */
1426 	if (hook->private == &privp->debug_hook) {
1427 		privp->debug_hook = NULL;
1428 	} else if (hook->private == &privp->ethernet_hook) {
1429 		privp->ethernet_hook = NULL;
1430 		ng_rmnode(node);
1431 	} else {
1432 		sp = hook->private;
1433 		if (sp->state != PPPOE_SNONE ) {
1434 			pppoe_send_event(sp, NGM_PPPOE_CLOSE);
1435 		}
1436 		/*
1437 		 * According to the spec, if we are connected,
1438 		 * we should send a DISC packet if we are shutting down
1439 		 * a session.
1440 		 */
1441 		if ((privp->ethernet_hook)
1442 		&& ((sp->state == PPPOE_CONNECTED)
1443 		 || (sp->state == PPPOE_NEWCONNECTED))) {
1444 			struct mbuf *m;
1445 			struct pppoe_full_hdr *wh;
1446 			struct pppoe_tag *tag;
1447 			int	msglen = strlen(SIGNOFF);
1448 			void *dummy = NULL;
1449 			int error = 0;
1450 
1451 			/* revert the stored header to DISC/PADT mode */
1452 		 	wh = &sp->pkt_hdr;
1453 			wh->ph.code = PADT_CODE;
1454 			if (pppoe_mode == PPPOE_NONSTANDARD)
1455 				wh->eh.ether_type = ETHERTYPE_PPPOE_STUPID_DISC;
1456 			else
1457 				wh->eh.ether_type = ETHERTYPE_PPPOE_DISC;
1458 
1459 			/* generate a packet of that type */
1460 			MGETHDR(m, M_NOWAIT, MT_DATA);
1461 			if(m == NULL)
1462 				kprintf("pppoe: Session out of mbufs\n");
1463 			else {
1464 				m->m_pkthdr.rcvif = NULL;
1465 				m->m_pkthdr.len = m->m_len = sizeof(*wh);
1466 				bcopy((caddr_t)wh, mtod(m, caddr_t),
1467 				    sizeof(*wh));
1468 				/*
1469 				 * Add a General error message and adjust
1470 				 * sizes
1471 				 */
1472 				wh = mtod(m, struct pppoe_full_hdr *);
1473 				tag = wh->ph.tag;
1474 				tag->tag_type = PTT_GEN_ERR;
1475 				tag->tag_len = htons((u_int16_t)msglen);
1476 				strncpy(tag->tag_data, SIGNOFF, msglen);
1477 				m->m_pkthdr.len = (m->m_len += sizeof(*tag) +
1478 				    msglen);
1479 				wh->ph.length = htons(sizeof(*tag) + msglen);
1480 				NG_SEND_DATA(error, privp->ethernet_hook, m,
1481 				    dummy);
1482 			}
1483 		}
1484 		/*
1485 		 * As long as we have somewhere to store the timeout handle,
1486 		 * we may have a timeout pending.. get rid of it.
1487 		 */
1488 		if (sp->neg) {
1489 			callout_stop(&sp->neg->timeout_ch);
1490 			if (sp->neg->m)
1491 				m_freem(sp->neg->m);
1492 			kfree(sp->neg, M_NETGRAPH);
1493 		}
1494 		kfree(sp, M_NETGRAPH);
1495 		hook->private = NULL;
1496 		/* work out how many session hooks there are */
1497 		/* Node goes away on last session hook removal */
1498 		if (privp->ethernet_hook) hooks -= 1;
1499 		if (privp->debug_hook) hooks -= 1;
1500 	}
1501 	if (node->numhooks == 0)
1502 		ng_rmnode(node);
1503 	return (0);
1504 }
1505 
1506 /*
1507  * timeouts come here.
1508  */
1509 static void
1510 pppoe_ticker(void *arg)
1511 {
1512 	hook_p hook = arg;
1513 	sessp	sp = hook->private;
1514 	negp	neg = sp->neg;
1515 	int	error = 0;
1516 	struct mbuf *m0 = NULL;
1517 	priv_p privp = hook->node->private;
1518 	meta_p dummy = NULL;
1519 
1520 	crit_enter();
1521 AAA
1522 	switch(sp->state) {
1523 		/*
1524 		 * resend the last packet, using an exponential backoff.
1525 		 * After a period of time, stop growing the backoff,
1526 		 * and either leave it, or revert to the start.
1527 		 */
1528 	case	PPPOE_SINIT:
1529 	case	PPPOE_SREQ:
1530 		/* timeouts on these produce resends */
1531 		m0 = m_copypacket(sp->neg->m, M_NOWAIT);
1532 		NG_SEND_DATA( error, privp->ethernet_hook, m0, dummy);
1533 		callout_reset(&neg->timeout_ch, neg->timeout * hz,
1534 				pppoe_ticker, hook);
1535 		if ((neg->timeout <<= 1) > PPPOE_TIMEOUT_LIMIT) {
1536 			if (sp->state == PPPOE_SREQ) {
1537 				/* revert to SINIT mode */
1538 				pppoe_start(sp);
1539 			} else {
1540 				neg->timeout = PPPOE_TIMEOUT_LIMIT;
1541 			}
1542 		}
1543 		break;
1544 	case	PPPOE_PRIMED:
1545 	case	PPPOE_SOFFER:
1546 		/* a timeout on these says "give up" */
1547 		ng_destroy_hook(hook);
1548 		break;
1549 	default:
1550 		/* timeouts have no meaning in other states */
1551 		kprintf("pppoe: unexpected timeout\n");
1552 	}
1553 	crit_exit();
1554 }
1555 
1556 
1557 static void
1558 sendpacket(sessp sp)
1559 {
1560 	int	error = 0;
1561 	struct mbuf *m0 = NULL;
1562 	hook_p hook = sp->hook;
1563 	negp	neg = sp->neg;
1564 	priv_p	privp = hook->node->private;
1565 	meta_p dummy = NULL;
1566 
1567 AAA
1568 	switch(sp->state) {
1569 	case	PPPOE_LISTENING:
1570 	case	PPPOE_DEAD:
1571 	case	PPPOE_SNONE:
1572 	case	PPPOE_CONNECTED:
1573 		kprintf("pppoe: sendpacket: unexpected state\n");
1574 		break;
1575 
1576 	case	PPPOE_NEWCONNECTED:
1577 		/* send the PADS without a timeout - we're now connected */
1578 		m0 = m_copypacket(sp->neg->m, M_NOWAIT);
1579 		NG_SEND_DATA( error, privp->ethernet_hook, m0, dummy);
1580 		break;
1581 
1582 	case	PPPOE_PRIMED:
1583 		/* No packet to send, but set up the timeout */
1584 		callout_reset(&neg->timeout_ch, PPPOE_OFFER_TIMEOUT * hz,
1585 				pppoe_ticker, hook);
1586 		break;
1587 
1588 	case	PPPOE_SOFFER:
1589 		/*
1590 		 * send the offer but if they don't respond
1591 		 * in PPPOE_OFFER_TIMEOUT seconds, forget about it.
1592 		 */
1593 		m0 = m_copypacket(sp->neg->m, M_NOWAIT);
1594 		NG_SEND_DATA( error, privp->ethernet_hook, m0, dummy);
1595 		callout_reset(&neg->timeout_ch, PPPOE_OFFER_TIMEOUT * hz,
1596 				pppoe_ticker, hook);
1597 		break;
1598 
1599 	case	PPPOE_SINIT:
1600 	case	PPPOE_SREQ:
1601 		m0 = m_copypacket(sp->neg->m, M_NOWAIT);
1602 		NG_SEND_DATA( error, privp->ethernet_hook, m0, dummy);
1603 		callout_reset(&neg->timeout_ch, PPPOE_INITIAL_TIMEOUT * hz,
1604 				pppoe_ticker, hook);
1605 		neg->timeout = PPPOE_INITIAL_TIMEOUT * 2;
1606 		break;
1607 
1608 	default:
1609 		error = EINVAL;
1610 		kprintf("pppoe: timeout: bad state\n");
1611 	}
1612 	/* return (error); */
1613 }
1614 
1615 /*
1616  * Parse an incoming packet to see if any tags should be copied to the
1617  * output packet. Don't do any tags that have been handled in the main
1618  * state machine.
1619  */
1620 static const struct pppoe_tag*
1621 scan_tags(sessp	sp, const struct pppoe_hdr* ph)
1622 {
1623 	const char *const end = (const char *)next_tag(ph);
1624 	const char *ptn;
1625 	const struct pppoe_tag *pt = &ph->tag[0];
1626 	/*
1627 	 * Keep processing tags while a tag header will still fit.
1628 	 */
1629 AAA
1630 	while((const char*)(pt + 1) <= end) {
1631 		/*
1632 		 * If the tag data would go past the end of the packet, abort.
1633 		 */
1634 		ptn = (((const char *)(pt + 1)) + ntohs(pt->tag_len));
1635 		if(ptn > end)
1636 			return NULL;
1637 
1638 		switch (pt->tag_type) {
1639 		case	PTT_RELAY_SID:
1640 			insert_tag(sp, pt);
1641 			break;
1642 		case	PTT_EOL:
1643 			return NULL;
1644 		case	PTT_SRV_NAME:
1645 		case	PTT_AC_NAME:
1646 		case	PTT_HOST_UNIQ:
1647 		case	PTT_AC_COOKIE:
1648 		case	PTT_VENDOR:
1649 		case	PTT_SRV_ERR:
1650 		case	PTT_SYS_ERR:
1651 		case	PTT_GEN_ERR:
1652 			break;
1653 		}
1654 		pt = (const struct pppoe_tag*)ptn;
1655 	}
1656 	return NULL;
1657 }
1658 
1659 static	int
1660 pppoe_send_event(sessp sp, enum cmd cmdid)
1661 {
1662 	int error;
1663 	struct ng_mesg *msg;
1664 	struct ngpppoe_sts *sts;
1665 
1666 AAA
1667 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, cmdid,
1668 			sizeof(struct ngpppoe_sts), M_NOWAIT);
1669 	if (msg == NULL)
1670 		return (ENOMEM);
1671 	sts = (struct ngpppoe_sts *)msg->data;
1672 	strlcpy(sts->hook, sp->hook->name, NG_HOOKSIZ);
1673 	error = ng_send_msg(sp->hook->node, msg, sp->creator, NULL);
1674 	return (error);
1675 }
1676