xref: /freebsd/sys/netgraph/ng_pppoe.c (revision 3ff369fed2a08f32dda232c10470b949bef9489f)
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  * $FreeBSD$
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", __func__ );
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 <sys/sysctl.h>
57 #include <net/ethernet.h>
58 
59 #include <netgraph/ng_message.h>
60 #include <netgraph/netgraph.h>
61 #include <netgraph/ng_parse.h>
62 #include <netgraph/ng_pppoe.h>
63 
64 #ifdef NG_SEPARATE_MALLOC
65 MALLOC_DEFINE(M_NETGRAPH_PPPOE, "netgraph_pppoe", "netgraph pppoe node");
66 #else
67 #define M_NETGRAPH_PPPOE M_NETGRAPH
68 #endif
69 
70 #define SIGNOFF "session closed"
71 #define OFFSETOF(s, e) ((char *)&((s *)0)->e - (char *)((s *)0))
72 
73 /*
74  * This section contains the netgraph method declarations for the
75  * pppoe node. These methods define the netgraph pppoe 'type'.
76  */
77 
78 static ng_constructor_t	ng_pppoe_constructor;
79 static ng_rcvmsg_t	ng_pppoe_rcvmsg;
80 static ng_shutdown_t	ng_pppoe_shutdown;
81 static ng_newhook_t	ng_pppoe_newhook;
82 static ng_connect_t	ng_pppoe_connect;
83 static ng_rcvdata_t	ng_pppoe_rcvdata;
84 static ng_disconnect_t	ng_pppoe_disconnect;
85 
86 /* Parse type for struct ngpppoe_init_data */
87 static const struct ng_parse_struct_field ngpppoe_init_data_type_fields[]
88 	= NG_PPPOE_INIT_DATA_TYPE_INFO;
89 static const struct ng_parse_type ngpppoe_init_data_state_type = {
90 	&ng_parse_struct_type,
91 	&ngpppoe_init_data_type_fields
92 };
93 
94 /* Parse type for struct ngpppoe_sts */
95 static const struct ng_parse_struct_field ng_pppoe_sts_type_fields[]
96 	= NG_PPPOE_STS_TYPE_INFO;
97 static const struct ng_parse_type ng_pppoe_sts_state_type = {
98 	&ng_parse_struct_type,
99 	&ng_pppoe_sts_type_fields
100 };
101 
102 /* List of commands and how to convert arguments to/from ASCII */
103 static const struct ng_cmdlist ng_pppoe_cmds[] = {
104 	{
105 	  NGM_PPPOE_COOKIE,
106 	  NGM_PPPOE_CONNECT,
107 	  "pppoe_connect",
108 	  &ngpppoe_init_data_state_type,
109 	  NULL
110 	},
111 	{
112 	  NGM_PPPOE_COOKIE,
113 	  NGM_PPPOE_LISTEN,
114 	  "pppoe_listen",
115 	  &ngpppoe_init_data_state_type,
116 	  NULL
117 	},
118 	{
119 	  NGM_PPPOE_COOKIE,
120 	  NGM_PPPOE_OFFER,
121 	  "pppoe_offer",
122 	  &ngpppoe_init_data_state_type,
123 	  NULL
124 	},
125 	{
126 	  NGM_PPPOE_COOKIE,
127 	  NGM_PPPOE_SERVICE,
128 	  "pppoe_service",
129 	  &ngpppoe_init_data_state_type,
130 	  NULL
131 	},
132 	{
133 	  NGM_PPPOE_COOKIE,
134 	  NGM_PPPOE_SUCCESS,
135 	  "pppoe_success",
136 	  &ng_pppoe_sts_state_type,
137 	  NULL
138 	},
139 	{
140 	  NGM_PPPOE_COOKIE,
141 	  NGM_PPPOE_FAIL,
142 	  "pppoe_fail",
143 	  &ng_pppoe_sts_state_type,
144 	  NULL
145 	},
146 	{
147 	  NGM_PPPOE_COOKIE,
148 	  NGM_PPPOE_CLOSE,
149 	  "pppoe_close",
150 	  &ng_pppoe_sts_state_type,
151 	  NULL
152 	},
153 	{ 0 }
154 };
155 
156 /* Netgraph node type descriptor */
157 static struct ng_type typestruct = {
158 	NG_ABI_VERSION,
159 	NG_PPPOE_NODE_TYPE,
160 	NULL,
161 	ng_pppoe_constructor,
162 	ng_pppoe_rcvmsg,
163 	ng_pppoe_shutdown,
164 	ng_pppoe_newhook,
165 	NULL,
166 	ng_pppoe_connect,
167 	ng_pppoe_rcvdata,
168 	ng_pppoe_disconnect,
169 	ng_pppoe_cmds
170 };
171 NETGRAPH_INIT(pppoe, &typestruct);
172 /* Depend on ng_ether so we can use the Ethernet parse type */
173 MODULE_DEPEND(ng_pppoe, ng_ether, 1, 1, 1);
174 
175 /*
176  * States for the session state machine.
177  * These have no meaning if there is no hook attached yet.
178  */
179 enum state {
180     PPPOE_SNONE=0,	/* [both] Initial state */
181     PPPOE_LISTENING,	/* [Daemon] Listening for discover initiation pkt */
182     PPPOE_SINIT,	/* [Client] Sent discovery initiation */
183     PPPOE_PRIMED,	/* [Server] Awaiting PADI from daemon */
184     PPPOE_SOFFER,	/* [Server] Sent offer message  (got PADI)*/
185     PPPOE_SREQ,		/* [Client] Sent a Request */
186     PPPOE_NEWCONNECTED,	/* [Server] Connection established, No data received */
187     PPPOE_CONNECTED,	/* [Both] Connection established, Data received */
188     PPPOE_DEAD		/* [Both] */
189 };
190 
191 #define NUMTAGS 20 /* number of tags we are set up to work with */
192 
193 /*
194  * Information we store for each hook on each node for negotiating the
195  * session. The mbuf and cluster are freed once negotiation has completed.
196  * The whole negotiation block is then discarded.
197  */
198 
199 struct sess_neg {
200 	struct mbuf 		*m; /* holds cluster with last sent packet */
201 	union	packet		*pkt; /* points within the above cluster */
202 	struct callout_handle	timeout_handle;   /* see timeout(9) */
203 	u_int			timeout; /* 0,1,2,4,8,16 etc. seconds */
204 	u_int			numtags;
205 	const struct pppoe_tag	*tags[NUMTAGS];
206 	u_int			service_len;
207 	u_int			ac_name_len;
208 
209 	struct datatag		service;
210 	struct datatag		ac_name;
211 };
212 typedef struct sess_neg *negp;
213 
214 /*
215  * Session information that is needed after connection.
216  */
217 struct sess_con {
218 	hook_p  		hook;
219 	u_int16_t		Session_ID;
220 	enum state		state;
221 	ng_ID_t			creator;		/* who to notify */
222 	struct pppoe_full_hdr	pkt_hdr;	/* used when connected */
223 	negp			neg;		/* used when negotiating */
224 	/*struct sess_con	*hash_next;*/	/* not yet used */
225 };
226 typedef struct sess_con *sessp;
227 
228 /*
229  * Information we store for each node
230  */
231 struct PPPOE {
232 	node_p		node;		/* back pointer to node */
233 	hook_p  	ethernet_hook;
234 	hook_p  	debug_hook;
235 	u_int   	packets_in;	/* packets in from ethernet */
236 	u_int   	packets_out;	/* packets out towards ethernet */
237 	u_int32_t	flags;
238 	/*struct sess_con *buckets[HASH_SIZE];*/	/* not yet used */
239 };
240 typedef struct PPPOE *priv_p;
241 
242 struct ether_header eh_prototype =
243 	{{0xff,0xff,0xff,0xff,0xff,0xff},
244 	 {0x00,0x00,0x00,0x00,0x00,0x00},
245 	 ETHERTYPE_PPPOE_DISC};
246 
247 static int nonstandard;
248 static int
249 ngpppoe_set_ethertype(SYSCTL_HANDLER_ARGS)
250 {
251 	int error;
252 	int val;
253 
254 	val = nonstandard;
255 	error = sysctl_handle_int(oidp, &val, sizeof(int), req);
256 	if (error != 0 || req->newptr == NULL)
257 		return (error);
258 	if (val == 1) {
259 		nonstandard = 1;
260 		eh_prototype.ether_type = ETHERTYPE_PPPOE_STUPID_DISC;
261 	} else {
262 		nonstandard = 0;
263 		eh_prototype.ether_type = ETHERTYPE_PPPOE_DISC;
264 	}
265 	return (0);
266 }
267 
268 SYSCTL_PROC(_net_graph, OID_AUTO, nonstandard_pppoe, CTLTYPE_INT | CTLFLAG_RW,
269     0, sizeof(int), ngpppoe_set_ethertype, "I", "select normal or stupid ISP");
270 
271 union uniq {
272 	char bytes[sizeof(void *)];
273 	void * pointer;
274 	};
275 
276 #define	LEAVE(x) do { error = x; goto quit; } while(0)
277 static void	pppoe_start(sessp sp);
278 static void	sendpacket(sessp sp);
279 static void	pppoe_ticker(void *arg);
280 static const	struct pppoe_tag *scan_tags(sessp sp,
281 			const struct pppoe_hdr* ph);
282 static	int	pppoe_send_event(sessp sp, enum cmd cmdid);
283 
284 /*************************************************************************
285  * Some basic utilities  from the Linux version with author's permission.*
286  * Author:	Michal Ostrowski <mostrows@styx.uwaterloo.ca>		 *
287  ************************************************************************/
288 
289 /*
290  * Generate a new session id
291  * XXX find out the FreeBSD locking scheme.
292  */
293 static u_int16_t
294 get_new_sid(node_p node)
295 {
296 	static int pppoe_sid = 10;
297 	sessp sp;
298 	hook_p	hook;
299 	u_int16_t val;
300 	priv_p privp = NG_NODE_PRIVATE(node);
301 
302 AAA
303 restart:
304 	val = pppoe_sid++;
305 	/*
306 	 * Spec says 0xFFFF is reserved.
307 	 * Also don't use 0x0000
308 	 */
309 	if (val == 0xffff) {
310 		pppoe_sid = 20;
311 		goto restart;
312 	}
313 
314 	/* Check it isn't already in use */
315 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
316 		/* don't check special hooks */
317 		if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook)
318 		||  (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook))
319 			continue;
320 		sp = NG_HOOK_PRIVATE(hook);
321 		if (sp->Session_ID == val)
322 			goto restart;
323 	}
324 
325 	return val;
326 }
327 
328 
329 /*
330  * Return the location where the next tag can be put
331  */
332 static __inline const struct pppoe_tag*
333 next_tag(const struct pppoe_hdr* ph)
334 {
335 	return (const struct pppoe_tag*)(((const char*)&ph->tag[0])
336 	    + ntohs(ph->length));
337 }
338 
339 /*
340  * Look for a tag of a specific type
341  * Don't trust any length the other end says.
342  * but assume we already sanity checked ph->length.
343  */
344 static const struct pppoe_tag*
345 get_tag(const struct pppoe_hdr* ph, u_int16_t idx)
346 {
347 	const char *const end = (const char *)next_tag(ph);
348 	const char *ptn;
349 	const struct pppoe_tag *pt = &ph->tag[0];
350 	/*
351 	 * Keep processing tags while a tag header will still fit.
352 	 */
353 AAA
354 	while((const char*)(pt + 1) <= end) {
355 	    /*
356 	     * If the tag data would go past the end of the packet, abort.
357 	     */
358 	    ptn = (((const char *)(pt + 1)) + ntohs(pt->tag_len));
359 	    if(ptn > end)
360 		return NULL;
361 
362 	    if(pt->tag_type == idx)
363 		return pt;
364 
365 	    pt = (const struct pppoe_tag*)ptn;
366 	}
367 	return NULL;
368 }
369 
370 /**************************************************************************
371  * inlines to initialise or add tags to a session's tag list,
372  **************************************************************************/
373 /*
374  * Initialise the session's tag list
375  */
376 static void
377 init_tags(sessp sp)
378 {
379 AAA
380 	if(sp->neg == NULL) {
381 		printf("pppoe: asked to init NULL neg pointer\n");
382 		return;
383 	}
384 	sp->neg->numtags = 0;
385 }
386 
387 static void
388 insert_tag(sessp sp, const struct pppoe_tag *tp)
389 {
390 	int	i;
391 	negp neg;
392 
393 AAA
394 	if((neg = sp->neg) == NULL) {
395 		printf("pppoe: asked to use NULL neg pointer\n");
396 		return;
397 	}
398 	if ((i = neg->numtags++) < NUMTAGS) {
399 		neg->tags[i] = tp;
400 	} else {
401 		printf("pppoe: asked to add too many tags to packet\n");
402 		neg->numtags--;
403 	}
404 }
405 
406 /*
407  * Make up a packet, using the tags filled out for the session.
408  *
409  * Assume that the actual pppoe header and ethernet header
410  * are filled out externally to this routine.
411  * Also assume that neg->wh points to the correct
412  * location at the front of the buffer space.
413  */
414 static void
415 make_packet(sessp sp) {
416 	struct pppoe_full_hdr *wh = &sp->neg->pkt->pkt_header;
417 	const struct pppoe_tag **tag;
418 	char *dp;
419 	int count;
420 	int tlen;
421 	u_int16_t length = 0;
422 
423 AAA
424 	if ((sp->neg == NULL) || (sp->neg->m == NULL)) {
425 		printf("pppoe: make_packet called from wrong state\n");
426 	}
427 	dp = (char *)wh->ph.tag;
428 	for (count = 0, tag = sp->neg->tags;
429 	    ((count < sp->neg->numtags) && (count < NUMTAGS));
430 	    tag++, count++) {
431 		tlen = ntohs((*tag)->tag_len) + sizeof(**tag);
432 		if ((length + tlen) > (ETHER_MAX_LEN - 4 - sizeof(*wh))) {
433 			printf("pppoe: tags too long\n");
434 			sp->neg->numtags = count;
435 			break;	/* XXX chop off what's too long */
436 		}
437 		bcopy(*tag, (char *)dp, tlen);
438 		length += tlen;
439 		dp += tlen;
440 	}
441  	wh->ph.length = htons(length);
442 	sp->neg->m->m_len = length + sizeof(*wh);
443 	sp->neg->m->m_pkthdr.len = length + sizeof(*wh);
444 }
445 
446 /**************************************************************************
447  * Routine to match a service offered					  *
448  **************************************************************************/
449 /*
450  * Find a hook that has a service string that matches that
451  * we are seeking. for now use a simple string.
452  * In the future we may need something like regexp().
453  * for testing allow a null string to match 1st found and a null service
454  * to match all requests. Also make '*' do the same.
455  */
456 
457 #define NG_MATCH_EXACT	1
458 #define NG_MATCH_ANY	2
459 
460 static hook_p
461 pppoe_match_svc(node_p node, const char *svc_name, int svc_len, int match)
462 {
463 	sessp	sp	= NULL;
464 	negp	neg	= NULL;
465 	priv_p	privp	= NG_NODE_PRIVATE(node);
466 	hook_p	allhook	= NULL;
467 	hook_p	hook;
468 
469 AAA
470 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
471 
472 		/* skip any hook that is debug or ethernet */
473 		if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook)
474 		||  (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook))
475 			continue;
476 		sp = NG_HOOK_PRIVATE(hook);
477 
478 		/* Skip any sessions which are not in LISTEN mode. */
479 		if ( sp->state != PPPOE_LISTENING)
480 			continue;
481 
482 		neg = sp->neg;
483 
484 		/* Special case for a blank or "*" service name (wildcard) */
485 		if (match == NG_MATCH_ANY && neg->service_len == 1 &&
486 		    neg->service.data[0] == '*') {
487 			allhook = hook;
488 			continue;
489 		}
490 
491 		/* If the lengths don't match, that aint it. */
492 		if (neg->service_len != svc_len)
493 			continue;
494 
495 		/* An exact match? */
496 		if (svc_len == 0)
497 			break;
498 
499 		if (strncmp(svc_name, neg->service.data, svc_len) == 0)
500 			break;
501 	}
502 	return (hook ? hook : allhook);
503 }
504 /**************************************************************************
505  * Routine to find a particular session that matches an incoming packet	  *
506  **************************************************************************/
507 static hook_p
508 pppoe_findsession(node_p node, const struct pppoe_full_hdr *wh)
509 {
510 	sessp	sp = NULL;
511 	hook_p hook = NULL;
512 	priv_p	privp = NG_NODE_PRIVATE(node);
513 	u_int16_t	session = ntohs(wh->ph.sid);
514 
515 	/*
516 	 * find matching peer/session combination.
517 	 */
518 AAA
519 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
520 		/* don't check special hooks */
521 		if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook)
522 		||  (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook)) {
523 			continue;
524 		}
525 		sp = NG_HOOK_PRIVATE(hook);
526 		if ( ( (sp->state == PPPOE_CONNECTED)
527 		    || (sp->state == PPPOE_NEWCONNECTED) )
528 		&& (sp->Session_ID == session)
529 		&& (bcmp(sp->pkt_hdr.eh.ether_dhost,
530 		    wh->eh.ether_shost,
531 		    ETHER_ADDR_LEN)) == 0) {
532 			break;
533 		}
534 	}
535 	return (hook);
536 }
537 
538 static hook_p
539 pppoe_finduniq(node_p node, const struct pppoe_tag *tag)
540 {
541 	hook_p hook = NULL;
542 	priv_p	privp = NG_NODE_PRIVATE(node);
543 	union uniq		uniq;
544 
545 AAA
546 	bcopy(tag->tag_data, uniq.bytes, sizeof(void *));
547 	/* cycle through all known hooks */
548 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
549 		/* don't check special hooks */
550 		if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook)
551 		||  (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook))
552 			continue;
553 		if (uniq.pointer == NG_HOOK_PRIVATE(hook))
554 			break;
555 	}
556 	return (hook);
557 }
558 
559 /**************************************************************************
560  * start of Netgraph entrypoints					  *
561  **************************************************************************/
562 
563 /*
564  * Allocate the private data structure and the generic node
565  * and link them together.
566  *
567  * ng_make_node_common() returns with a generic node struct
568  * with a single reference for us.. we transfer it to the
569  * private structure.. when we free the private struct we must
570  * unref the node so it gets freed too.
571  */
572 static int
573 ng_pppoe_constructor(node_p node)
574 {
575 	priv_p privdata;
576 
577 AAA
578 	/* Initialize private descriptor */
579 	MALLOC(privdata, priv_p, sizeof(*privdata), M_NETGRAPH_PPPOE,
580 	    M_NOWAIT | M_ZERO);
581 	if (privdata == NULL)
582 		return (ENOMEM);
583 
584 	/* Link structs together; this counts as our one reference to *nodep */
585 	NG_NODE_SET_PRIVATE(node, privdata);
586 	privdata->node = node;
587 	return (0);
588 }
589 
590 /*
591  * Give our ok for a hook to be added...
592  * point the hook's private info to the hook structure.
593  *
594  * The following hook names are special:
595  *  Ethernet:  the hook that should be connected to a NIC.
596  *  debug:	copies of data sent out here  (when I write the code).
597  * All other hook names need only be unique. (the framework checks this).
598  */
599 static int
600 ng_pppoe_newhook(node_p node, hook_p hook, const char *name)
601 {
602 	const priv_p privp = NG_NODE_PRIVATE(node);
603 	sessp sp;
604 
605 AAA
606 	if (strcmp(name, NG_PPPOE_HOOK_ETHERNET) == 0) {
607 		privp->ethernet_hook = hook;
608 		NG_HOOK_SET_PRIVATE(hook, &privp->ethernet_hook);
609 	} else if (strcmp(name, NG_PPPOE_HOOK_DEBUG) == 0) {
610 		privp->debug_hook = hook;
611 		NG_HOOK_SET_PRIVATE(hook, &privp->debug_hook);
612 	} else {
613 		/*
614 		 * Any other unique name is OK.
615 		 * The infrastructure has already checked that it's unique,
616 		 * so just allocate it and hook it in.
617 		 */
618 		MALLOC(sp, sessp, sizeof(*sp), M_NETGRAPH_PPPOE, M_NOWAIT | M_ZERO);
619 		if (sp == NULL) {
620 				return (ENOMEM);
621 		}
622 
623 		NG_HOOK_SET_PRIVATE(hook, sp);
624 		sp->hook = hook;
625 	}
626 	return(0);
627 }
628 
629 /*
630  * Get a netgraph control message.
631  * Check it is one we understand. If needed, send a response.
632  * We sometimes save the address for an async action later.
633  * Always free the message.
634  */
635 static int
636 ng_pppoe_rcvmsg(node_p node, item_p item, hook_p lasthook)
637 {
638 	priv_p privp = NG_NODE_PRIVATE(node);
639 	struct ngpppoe_init_data *ourmsg = NULL;
640 	struct ng_mesg *resp = NULL;
641 	int error = 0;
642 	hook_p hook = NULL;
643 	sessp sp = NULL;
644 	negp neg = NULL;
645 	struct ng_mesg *msg;
646 
647 AAA
648 	NGI_GET_MSG(item, msg);
649 	/* Deal with message according to cookie and command */
650 	switch (msg->header.typecookie) {
651 	case NGM_PPPOE_COOKIE:
652 		switch (msg->header.cmd) {
653 		case NGM_PPPOE_CONNECT:
654 		case NGM_PPPOE_LISTEN:
655 		case NGM_PPPOE_OFFER:
656 		case NGM_PPPOE_SERVICE:
657 			ourmsg = (struct ngpppoe_init_data *)msg->data;
658 			if (msg->header.arglen < sizeof(*ourmsg)) {
659 				printf("pppoe: init data too small\n");
660 				LEAVE(EMSGSIZE);
661 			}
662 			if (msg->header.arglen - sizeof(*ourmsg) >
663 			    PPPOE_SERVICE_NAME_SIZE) {
664 				printf("pppoe_rcvmsg: service name too big");
665 				LEAVE(EMSGSIZE);
666 			}
667 			if (msg->header.arglen - sizeof(*ourmsg) <
668 			    ourmsg->data_len) {
669 				printf("pppoe: init data has bad length,"
670 				    " %d should be %d\n", ourmsg->data_len,
671 				    msg->header.arglen - sizeof (*ourmsg));
672 				LEAVE(EMSGSIZE);
673 			}
674 
675 			/* make sure strcmp will terminate safely */
676 			ourmsg->hook[sizeof(ourmsg->hook) - 1] = '\0';
677 
678 			/* cycle through all known hooks */
679 			LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
680 				if (NG_HOOK_NAME(hook)
681 				&& strcmp(NG_HOOK_NAME(hook), ourmsg->hook) == 0)
682 					break;
683 			}
684 			if (hook == NULL) {
685 				LEAVE(ENOENT);
686 			}
687 			if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook)
688 			||  (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook)) {
689 				LEAVE(EINVAL);
690 			}
691 			sp = NG_HOOK_PRIVATE(hook);
692 
693 			if (msg->header.cmd == NGM_PPPOE_LISTEN) {
694 				/*
695 				 * Ensure we aren't already listening for this
696 				 * service.
697 				 */
698 				if (pppoe_match_svc(node, ourmsg->data,
699 				    ourmsg->data_len, NG_MATCH_EXACT) != NULL) {
700 					LEAVE(EEXIST);
701 				}
702 			}
703 
704 			/*
705 			 * PPPOE_SERVICE advertisments are set up
706 			 * on sessions that are in PRIMED state.
707 			 */
708 			if (msg->header.cmd == NGM_PPPOE_SERVICE) {
709 				break;
710 			}
711 			if (sp->state |= PPPOE_SNONE) {
712 				printf("pppoe: Session already active\n");
713 				LEAVE(EISCONN);
714 			}
715 
716 			/*
717 			 * set up prototype header
718 			 */
719 			MALLOC(neg, negp, sizeof(*neg), M_NETGRAPH_PPPOE,
720 			    M_NOWAIT | M_ZERO);
721 
722 			if (neg == NULL) {
723 				printf("pppoe: Session out of memory\n");
724 				LEAVE(ENOMEM);
725 			}
726 			MGETHDR(neg->m, M_DONTWAIT, MT_DATA);
727 			if(neg->m == NULL) {
728 				printf("pppoe: Session out of mbufs\n");
729 				FREE(neg, M_NETGRAPH_PPPOE);
730 				LEAVE(ENOBUFS);
731 			}
732 			neg->m->m_pkthdr.rcvif = NULL;
733 			MCLGET(neg->m, M_DONTWAIT);
734 			if ((neg->m->m_flags & M_EXT) == 0) {
735 				printf("pppoe: Session out of mcls\n");
736 				m_freem(neg->m);
737 				FREE(neg, M_NETGRAPH_PPPOE);
738 				LEAVE(ENOBUFS);
739 			}
740 			sp->neg = neg;
741 			callout_handle_init( &neg->timeout_handle);
742 			neg->m->m_len = sizeof(struct pppoe_full_hdr);
743 			neg->pkt = mtod(neg->m, union packet*);
744 			neg->pkt->pkt_header.eh = eh_prototype;
745 			neg->pkt->pkt_header.ph.ver = 0x1;
746 			neg->pkt->pkt_header.ph.type = 0x1;
747 			neg->pkt->pkt_header.ph.sid = 0x0000;
748 			neg->timeout = 0;
749 
750 			sp->creator = NGI_RETADDR(item);
751 		}
752 		switch (msg->header.cmd) {
753 		case NGM_PPPOE_GET_STATUS:
754 		    {
755 			struct ngpppoestat *stats;
756 
757 			NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT);
758 			if (!resp) {
759 				LEAVE(ENOMEM);
760 			}
761 			stats = (struct ngpppoestat *) resp->data;
762 			stats->packets_in = privp->packets_in;
763 			stats->packets_out = privp->packets_out;
764 			break;
765 		    }
766 		case NGM_PPPOE_CONNECT:
767 			/*
768 			 * Check the hook exists and is Uninitialised.
769 			 * Send a PADI request, and start the timeout logic.
770 			 * Store the originator of this message so we can send
771 			 * a success of fail message to them later.
772 			 * Move the session to SINIT
773 			 * Set up the session to the correct state and
774 			 * start it.
775 			 */
776 			neg->service.hdr.tag_type = PTT_SRV_NAME;
777 			neg->service.hdr.tag_len =
778 			    htons((u_int16_t)ourmsg->data_len);
779 			if (ourmsg->data_len)
780 				bcopy(ourmsg->data, neg->service.data,
781 				    ourmsg->data_len);
782 			neg->service_len = ourmsg->data_len;
783 			pppoe_start(sp);
784 			break;
785 		case NGM_PPPOE_LISTEN:
786 			/*
787 			 * Check the hook exists and is Uninitialised.
788 			 * Install the service matching string.
789 			 * Store the originator of this message so we can send
790 			 * a success of fail message to them later.
791 			 * Move the hook to 'LISTENING'
792 			 */
793 			neg->service.hdr.tag_type = PTT_SRV_NAME;
794 			neg->service.hdr.tag_len =
795 			    htons((u_int16_t)ourmsg->data_len);
796 
797 			if (ourmsg->data_len)
798 				bcopy(ourmsg->data, neg->service.data,
799 				    ourmsg->data_len);
800 			neg->service_len = ourmsg->data_len;
801 			neg->pkt->pkt_header.ph.code = PADT_CODE;
802 			/*
803 			 * wait for PADI packet coming from ethernet
804 			 */
805 			sp->state = PPPOE_LISTENING;
806 			break;
807 		case NGM_PPPOE_OFFER:
808 			/*
809 			 * Check the hook exists and is Uninitialised.
810 			 * Store the originator of this message so we can send
811 			 * a success of fail message to them later.
812 			 * Store the AC-Name given and go to PRIMED.
813 			 */
814 			neg->ac_name.hdr.tag_type = PTT_AC_NAME;
815 			neg->ac_name.hdr.tag_len =
816 			    htons((u_int16_t)ourmsg->data_len);
817 			if (ourmsg->data_len)
818 				bcopy(ourmsg->data, neg->ac_name.data,
819 				    ourmsg->data_len);
820 			neg->ac_name_len = ourmsg->data_len;
821 			neg->pkt->pkt_header.ph.code = PADO_CODE;
822 			/*
823 			 * Wait for PADI packet coming from hook
824 			 */
825 			sp->state = PPPOE_PRIMED;
826 			break;
827 		case NGM_PPPOE_SERVICE:
828 			/*
829 			 * Check the session is primed.
830 			 * for now just allow ONE service to be advertised.
831 			 * If you do it twice you just overwrite.
832 			 */
833 			if (sp->state != PPPOE_PRIMED) {
834 				printf("pppoe: Session not primed\n");
835 				LEAVE(EISCONN);
836 			}
837 			neg = sp->neg;
838 			neg->service.hdr.tag_type = PTT_SRV_NAME;
839 			neg->service.hdr.tag_len =
840 			    htons((u_int16_t)ourmsg->data_len);
841 
842 			if (ourmsg->data_len)
843 				bcopy(ourmsg->data, neg->service.data,
844 				    ourmsg->data_len);
845 			neg->service_len = ourmsg->data_len;
846 			break;
847 		default:
848 			LEAVE(EINVAL);
849 		}
850 		break;
851 	default:
852 		LEAVE(EINVAL);
853 	}
854 
855 	/* Take care of synchronous response, if any */
856 quit:
857 	NG_RESPOND_MSG(error, node, item, resp);
858 	/* Free the message and return */
859 	NG_FREE_MSG(msg);
860 	return(error);
861 }
862 
863 /*
864  * Start a client into the first state. A separate function because
865  * it can be needed if the negotiation times out.
866  */
867 static void
868 pppoe_start(sessp sp)
869 {
870 	struct {
871 		struct pppoe_tag hdr;
872 		union	uniq	data;
873 	} __attribute ((packed)) uniqtag;
874 
875 	/*
876 	 * kick the state machine into starting up
877 	 */
878 AAA
879 	sp->state = PPPOE_SINIT;
880 	/* reset the packet header to broadcast */
881 	sp->neg->pkt->pkt_header.eh = eh_prototype;
882 	sp->neg->pkt->pkt_header.ph.code = PADI_CODE;
883 	uniqtag.hdr.tag_type = PTT_HOST_UNIQ;
884 	uniqtag.hdr.tag_len = htons((u_int16_t)sizeof(uniqtag.data));
885 	uniqtag.data.pointer = sp;
886 	init_tags(sp);
887 	insert_tag(sp, &uniqtag.hdr);
888 	insert_tag(sp, &sp->neg->service.hdr);
889 	make_packet(sp);
890 	sendpacket(sp);
891 }
892 
893 static int
894 send_acname(sessp sp, const struct pppoe_tag *tag)
895 {
896 	int error;
897 	struct ng_mesg *msg;
898 	struct ngpppoe_sts *sts;
899 
900 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_ACNAME,
901 	    sizeof(struct ngpppoe_sts), M_NOWAIT);
902 	if (msg == NULL)
903 		return (ENOMEM);
904 
905 	sts = (struct ngpppoe_sts *)msg->data;
906 	strncpy(sts->hook, tag->tag_data,
907 	    min(NG_HOOKLEN + 1, ntohs(tag->tag_len)));
908 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, NULL);
909 
910 	return (error);
911 }
912 
913 static int
914 send_sessionid(sessp sp)
915 {
916 	int error;
917 	struct ng_mesg *msg;
918 
919 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_SESSIONID,
920 	    sizeof(u_int16_t), M_NOWAIT);
921 	if (msg == NULL)
922 		return (ENOMEM);
923 
924 	*(u_int16_t *)msg->data = sp->Session_ID;
925 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, NULL);
926 
927 	return (error);
928 }
929 
930 /*
931  * Receive data, and do something with it.
932  * The caller will never free m or meta, so
933  * if we use up this data or abort we must free BOTH of these.
934  */
935 static int
936 ng_pppoe_rcvdata(hook_p hook, item_p item)
937 {
938 	node_p			node = NG_HOOK_NODE(hook);
939 	const priv_p		privp = NG_NODE_PRIVATE(node);
940 	sessp			sp = NG_HOOK_PRIVATE(hook);
941 	const struct pppoe_full_hdr *wh;
942 	const struct pppoe_hdr	*ph;
943 	int			error = 0;
944 	u_int16_t		session;
945 	u_int16_t		length;
946 	u_int8_t		code;
947 	const struct pppoe_tag	*utag = NULL, *tag = NULL;
948 	hook_p 			sendhook;
949 	struct {
950 		struct pppoe_tag hdr;
951 		union	uniq	data;
952 	} __attribute ((packed)) uniqtag;
953 	negp			neg = NULL;
954 	struct mbuf		*m;
955 
956 AAA
957 	NGI_GET_M(item, m);
958 	if (NG_HOOK_PRIVATE(hook) == &privp->debug_hook) {
959 		/*
960 		 * Data from the debug hook gets sent without modification
961 		 * straight to the ethernet.
962 		 */
963 		NG_FWD_ITEM_HOOK( error, item, privp->ethernet_hook);
964 	 	privp->packets_out++;
965 	} else if (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook) {
966 		/*
967 		 * Incoming data.
968 		 * Dig out various fields from the packet.
969 		 * use them to decide where to send it.
970 		 */
971 
972  		privp->packets_in++;
973 		if( m->m_len < sizeof(*wh)) {
974 			m = m_pullup(m, sizeof(*wh)); /* Checks length */
975 			if (m == NULL) {
976 				printf("couldn't m_pullup\n");
977 				LEAVE(ENOBUFS);
978 			}
979 		}
980 		wh = mtod(m, struct pppoe_full_hdr *);
981 		length = ntohs(wh->ph.length);
982 		switch(wh->eh.ether_type) {
983 		case	ETHERTYPE_PPPOE_STUPID_DISC:
984 			nonstandard = 1;
985 			eh_prototype.ether_type = ETHERTYPE_PPPOE_STUPID_DISC;
986 			/* fall through */
987 		case	ETHERTYPE_PPPOE_DISC:
988 			/*
989 			 * We need to try to make sure that the tag area
990 			 * is contiguous, or we could wander off the end
991 			 * of a buffer and make a mess.
992 			 * (Linux wouldn't have this problem).
993 			 */
994 			if (m->m_pkthdr.len <= MHLEN) {
995 				if( m->m_len < m->m_pkthdr.len) {
996 					m = m_pullup(m, m->m_pkthdr.len);
997 					if (m == NULL) {
998 						printf("couldn't m_pullup\n");
999 						LEAVE(ENOBUFS);
1000 					}
1001 				}
1002 			}
1003 			if (m->m_len != m->m_pkthdr.len) {
1004 				/*
1005 				 * It's not all in one piece.
1006 				 * We need to do extra work.
1007 				 * Put it into a cluster.
1008 				 */
1009 				struct mbuf *n;
1010 				n = m_dup(m, M_DONTWAIT);
1011 				m_freem(m);
1012 				m = n;
1013 				if (m) {
1014 					/* just check we got a cluster */
1015 					if (m->m_len != m->m_pkthdr.len) {
1016 						m_freem(m);
1017 						m = NULL;
1018 					}
1019 				}
1020 				if (m == NULL) {
1021 					printf("packet fragmented\n");
1022 					LEAVE(EMSGSIZE);
1023 				}
1024 			}
1025 			wh = mtod(m, struct pppoe_full_hdr *);
1026 			length = ntohs(wh->ph.length);
1027 			ph = &wh->ph;
1028 			session = ntohs(wh->ph.sid);
1029 			code = wh->ph.code;
1030 
1031 			switch(code) {
1032 			case	PADI_CODE:
1033 				/*
1034 				 * We are a server:
1035 				 * Look for a hook with the required service
1036 				 * and send the ENTIRE packet up there.
1037 				 * It should come back to a new hook in
1038 				 * PRIMED state. Look there for further
1039 				 * processing.
1040 				 */
1041 				tag = get_tag(ph, PTT_SRV_NAME);
1042 				if (tag == NULL) {
1043 					printf("no service tag\n");
1044 					LEAVE(ENETUNREACH);
1045 				}
1046 				sendhook = pppoe_match_svc(NG_HOOK_NODE(hook),
1047 			    		tag->tag_data, ntohs(tag->tag_len),
1048 					NG_MATCH_ANY);
1049 				if (sendhook) {
1050 					NG_FWD_NEW_DATA(error, item,
1051 								sendhook, m);
1052 				} else {
1053 					LEAVE(ENETUNREACH);
1054 				}
1055 				break;
1056 			case	PADO_CODE:
1057 				/*
1058 				 * We are a client:
1059 				 * Use the host_uniq tag to find the
1060 				 * hook this is in response to.
1061 				 * Received #2, now send #3
1062 				 * For now simply accept the first we receive.
1063 				 */
1064 				utag = get_tag(ph, PTT_HOST_UNIQ);
1065 				if ((utag == NULL)
1066 				|| (ntohs(utag->tag_len) != sizeof(sp))) {
1067 					printf("no host unique field\n");
1068 					LEAVE(ENETUNREACH);
1069 				}
1070 
1071 				sendhook = pppoe_finduniq(node, utag);
1072 				if (sendhook == NULL) {
1073 					printf("no matching session\n");
1074 					LEAVE(ENETUNREACH);
1075 				}
1076 
1077 				/*
1078 				 * Check the session is in the right state.
1079 				 * It needs to be in PPPOE_SINIT.
1080 				 */
1081 				sp = NG_HOOK_PRIVATE(sendhook);
1082 				if (sp->state != PPPOE_SINIT) {
1083 					printf("session in wrong state\n");
1084 					LEAVE(ENETUNREACH);
1085 				}
1086 				neg = sp->neg;
1087 				untimeout(pppoe_ticker, sendhook,
1088 				    neg->timeout_handle);
1089 
1090 				/*
1091 				 * This is the first time we hear
1092 				 * from the server, so note it's
1093 				 * unicast address, replacing the
1094 				 * broadcast address .
1095 				 */
1096 				bcopy(wh->eh.ether_shost,
1097 					neg->pkt->pkt_header.eh.ether_dhost,
1098 					ETHER_ADDR_LEN);
1099 				neg->timeout = 0;
1100 				neg->pkt->pkt_header.ph.code = PADR_CODE;
1101 				init_tags(sp);
1102 				insert_tag(sp, utag);      /* Host Unique */
1103 				if ((tag = get_tag(ph, PTT_AC_COOKIE)))
1104 					insert_tag(sp, tag); /* return cookie */
1105 				if ((tag = get_tag(ph, PTT_AC_NAME))) {
1106 					insert_tag(sp, tag); /* return it */
1107 					send_acname(sp, tag);
1108 				}
1109 				insert_tag(sp, &neg->service.hdr); /* Service */
1110 				scan_tags(sp, ph);
1111 				make_packet(sp);
1112 				sp->state = PPPOE_SREQ;
1113 				sendpacket(sp);
1114 				break;
1115 			case	PADR_CODE:
1116 
1117 				/*
1118 				 * We are a server:
1119 				 * Use the ac_cookie tag to find the
1120 				 * hook this is in response to.
1121 				 */
1122 				utag = get_tag(ph, PTT_AC_COOKIE);
1123 				if ((utag == NULL)
1124 				|| (ntohs(utag->tag_len) != sizeof(sp))) {
1125 					LEAVE(ENETUNREACH);
1126 				}
1127 
1128 				sendhook = pppoe_finduniq(node, utag);
1129 				if (sendhook == NULL) {
1130 					LEAVE(ENETUNREACH);
1131 				}
1132 
1133 				/*
1134 				 * Check the session is in the right state.
1135 				 * It needs to be in PPPOE_SOFFER
1136 				 * or PPPOE_NEWCONNECTED. If the latter,
1137 				 * then this is a retry by the client.
1138 				 * so be nice, and resend.
1139 				 */
1140 				sp = NG_HOOK_PRIVATE(sendhook);
1141 				if (sp->state == PPPOE_NEWCONNECTED) {
1142 					/*
1143 					 * Whoa! drop back to resend that
1144 					 * PADS packet.
1145 					 * We should still have a copy of it.
1146 					 */
1147 					sp->state = PPPOE_SOFFER;
1148 				}
1149 				if (sp->state != PPPOE_SOFFER) {
1150 					LEAVE (ENETUNREACH);
1151 					break;
1152 				}
1153 				neg = sp->neg;
1154 				untimeout(pppoe_ticker, sendhook,
1155 				    neg->timeout_handle);
1156 				neg->pkt->pkt_header.ph.code = PADS_CODE;
1157 				if (sp->Session_ID == 0)
1158 					neg->pkt->pkt_header.ph.sid =
1159 					    htons(sp->Session_ID
1160 						= get_new_sid(node));
1161 				send_sessionid(sp);
1162 				neg->timeout = 0;
1163 				/*
1164 				 * start working out the tags to respond with.
1165 				 */
1166 				init_tags(sp);
1167 				insert_tag(sp, &neg->ac_name.hdr); /* AC_NAME */
1168 				if ((tag = get_tag(ph, PTT_SRV_NAME)))
1169 					insert_tag(sp, tag);/* return service */
1170 				if ((tag = get_tag(ph, PTT_HOST_UNIQ)))
1171 					insert_tag(sp, tag); /* return it */
1172 				insert_tag(sp, utag);	/* ac_cookie */
1173 				scan_tags(sp, ph);
1174 				make_packet(sp);
1175 				sp->state = PPPOE_NEWCONNECTED;
1176 				sendpacket(sp);
1177 				/*
1178 				 * Having sent the last Negotiation header,
1179 				 * Set up the stored packet header to
1180 				 * be correct for the actual session.
1181 				 * But keep the negotialtion stuff
1182 				 * around in case we need to resend this last
1183 				 * packet. We'll discard it when we move
1184 				 * from NEWCONNECTED to CONNECTED
1185 				 */
1186 				sp->pkt_hdr = neg->pkt->pkt_header;
1187 				if (nonstandard)
1188 					sp->pkt_hdr.eh.ether_type
1189 						= ETHERTYPE_PPPOE_STUPID_SESS;
1190 				else
1191 					sp->pkt_hdr.eh.ether_type
1192 						= ETHERTYPE_PPPOE_SESS;
1193 				sp->pkt_hdr.ph.code = 0;
1194 				pppoe_send_event(sp, NGM_PPPOE_SUCCESS);
1195 				break;
1196 			case	PADS_CODE:
1197 				/*
1198 				 * We are a client:
1199 				 * Use the host_uniq tag to find the
1200 				 * hook this is in response to.
1201 				 * take the session ID and store it away.
1202 				 * Also make sure the pre-made header is
1203 				 * correct and set us into Session mode.
1204 				 */
1205 				utag = get_tag(ph, PTT_HOST_UNIQ);
1206 				if ((utag == NULL)
1207 				|| (ntohs(utag->tag_len) != sizeof(sp))) {
1208 					LEAVE (ENETUNREACH);
1209 					break;
1210 				}
1211 				sendhook = pppoe_finduniq(node, utag);
1212 				if (sendhook == NULL) {
1213 					LEAVE(ENETUNREACH);
1214 				}
1215 
1216 				/*
1217 				 * Check the session is in the right state.
1218 				 * It needs to be in PPPOE_SREQ.
1219 				 */
1220 				sp = NG_HOOK_PRIVATE(sendhook);
1221 				if (sp->state != PPPOE_SREQ) {
1222 					LEAVE(ENETUNREACH);
1223 				}
1224 				neg = sp->neg;
1225 				untimeout(pppoe_ticker, sendhook,
1226 				    neg->timeout_handle);
1227 				neg->pkt->pkt_header.ph.sid = wh->ph.sid;
1228 				sp->Session_ID = ntohs(wh->ph.sid);
1229 				send_sessionid(sp);
1230 				neg->timeout = 0;
1231 				sp->state = PPPOE_CONNECTED;
1232 				/*
1233 				 * Now we have gone to Connected mode,
1234 				 * Free all resources needed for
1235 				 * negotiation.
1236 				 * Keep a copy of the header we will be using.
1237 				 */
1238 				sp->pkt_hdr = neg->pkt->pkt_header;
1239 				if (nonstandard)
1240 					sp->pkt_hdr.eh.ether_type
1241 						= ETHERTYPE_PPPOE_STUPID_SESS;
1242 				else
1243 					sp->pkt_hdr.eh.ether_type
1244 						= ETHERTYPE_PPPOE_SESS;
1245 				sp->pkt_hdr.ph.code = 0;
1246 				m_freem(neg->m);
1247 				FREE(sp->neg, M_NETGRAPH_PPPOE);
1248 				sp->neg = NULL;
1249 				pppoe_send_event(sp, NGM_PPPOE_SUCCESS);
1250 				break;
1251 			case	PADT_CODE:
1252 				/*
1253 				 * Send a 'close' message to the controlling
1254 				 * process (the one that set us up);
1255 				 * And then tear everything down.
1256 				 *
1257 				 * Find matching peer/session combination.
1258 				 */
1259 				sendhook = pppoe_findsession(node, wh);
1260 				if (sendhook == NULL) {
1261 					LEAVE(ENETUNREACH);
1262 				}
1263 				/* send message to creator */
1264 				/* close hook */
1265 				if (sendhook) {
1266 					ng_rmhook_self(sendhook);
1267 				}
1268 				break;
1269 			default:
1270 				LEAVE(EPFNOSUPPORT);
1271 			}
1272 			break;
1273 		case	ETHERTYPE_PPPOE_STUPID_SESS:
1274 		case	ETHERTYPE_PPPOE_SESS:
1275 			/*
1276 			 * find matching peer/session combination.
1277 			 */
1278 			sendhook = pppoe_findsession(node, wh);
1279 			if (sendhook == NULL) {
1280 				LEAVE (ENETUNREACH);
1281 				break;
1282 			}
1283 			sp = NG_HOOK_PRIVATE(sendhook);
1284 			m_adj(m, sizeof(*wh));
1285 			if (m->m_pkthdr.len < length) {
1286 				/* Packet too short, dump it */
1287 				LEAVE(EMSGSIZE);
1288 			}
1289 
1290 			/* Also need to trim excess at the end */
1291 			if (m->m_pkthdr.len > length) {
1292 				m_adj(m, -((int)(m->m_pkthdr.len - length)));
1293 			}
1294 			if ( sp->state != PPPOE_CONNECTED) {
1295 				if (sp->state == PPPOE_NEWCONNECTED) {
1296 					sp->state = PPPOE_CONNECTED;
1297 					/*
1298 					 * Now we have gone to Connected mode,
1299 					 * Free all resources needed for
1300 					 * negotiation. Be paranoid about
1301 					 * whether there may be a timeout.
1302 					 */
1303 					m_freem(sp->neg->m);
1304 					untimeout(pppoe_ticker, sendhook,
1305 				    		sp->neg->timeout_handle);
1306 					FREE(sp->neg, M_NETGRAPH_PPPOE);
1307 					sp->neg = NULL;
1308 				} else {
1309 					LEAVE (ENETUNREACH);
1310 					break;
1311 				}
1312 			}
1313 			NG_FWD_NEW_DATA( error, item, sendhook, m);
1314 			break;
1315 		default:
1316 			LEAVE(EPFNOSUPPORT);
1317 		}
1318 	} else {
1319 		/*
1320 		 * 	Not ethernet or debug hook..
1321 		 *
1322 		 * The packet has come in on a normal hook.
1323 		 * We need to find out what kind of hook,
1324 		 * So we can decide how to handle it.
1325 		 * Check the hook's state.
1326 		 */
1327 		sp = NG_HOOK_PRIVATE(hook);
1328 		switch (sp->state) {
1329 		case	PPPOE_NEWCONNECTED:
1330 		case	PPPOE_CONNECTED: {
1331 			static const u_char addrctrl[] = { 0xff, 0x03 };
1332 			struct pppoe_full_hdr *wh;
1333 
1334 			/*
1335 			 * Remove PPP address and control fields, if any.
1336 			 * For example, ng_ppp(4) always sends LCP packets
1337 			 * with address and control fields as required by
1338 			 * generic PPP. PPPoE is an exception to the rule.
1339 			 */
1340 			if (m->m_pkthdr.len >= 2) {
1341 				if (m->m_len < 2 && !(m = m_pullup(m, 2)))
1342 					LEAVE(ENOBUFS);
1343 				if (bcmp(mtod(m, u_char *), addrctrl, 2) == 0)
1344 					m_adj(m, 2);
1345 			}
1346 			/*
1347 			 * Bang in a pre-made header, and set the length up
1348 			 * to be correct. Then send it to the ethernet driver.
1349 			 * But first correct the length.
1350 			 */
1351 			sp->pkt_hdr.ph.length = htons((short)(m->m_pkthdr.len));
1352 			M_PREPEND(m, sizeof(*wh), M_DONTWAIT);
1353 			if (m == NULL) {
1354 				LEAVE(ENOBUFS);
1355 			}
1356 			wh = mtod(m, struct pppoe_full_hdr *);
1357 			bcopy(&sp->pkt_hdr, wh, sizeof(*wh));
1358 			NG_FWD_NEW_DATA( error, item, privp->ethernet_hook, m);
1359 			privp->packets_out++;
1360 			break;
1361 			}
1362 		case	PPPOE_PRIMED:
1363 			/*
1364 			 * A PADI packet is being returned by the application
1365 			 * that has set up this hook. This indicates that it
1366 			 * wants us to offer service.
1367 			 */
1368 			neg = sp->neg;
1369 			if (m->m_len < sizeof(*wh)) {
1370 				m = m_pullup(m, sizeof(*wh));
1371 				if (m == NULL) {
1372 					LEAVE(ENOBUFS);
1373 				}
1374 			}
1375 			wh = mtod(m, struct pppoe_full_hdr *);
1376 			ph = &wh->ph;
1377 			session = ntohs(wh->ph.sid);
1378 			length = ntohs(wh->ph.length);
1379 			code = wh->ph.code;
1380 			if ( code != PADI_CODE) {
1381 				LEAVE(EINVAL);
1382 			};
1383 			untimeout(pppoe_ticker, hook,
1384 				    neg->timeout_handle);
1385 
1386 			/*
1387 			 * This is the first time we hear
1388 			 * from the client, so note it's
1389 			 * unicast address, replacing the
1390 			 * broadcast address.
1391 			 */
1392 			bcopy(wh->eh.ether_shost,
1393 				neg->pkt->pkt_header.eh.ether_dhost,
1394 				ETHER_ADDR_LEN);
1395 			sp->state = PPPOE_SOFFER;
1396 			neg->timeout = 0;
1397 			neg->pkt->pkt_header.ph.code = PADO_CODE;
1398 
1399 			/*
1400 			 * start working out the tags to respond with.
1401 			 */
1402 			uniqtag.hdr.tag_type = PTT_AC_COOKIE;
1403 			uniqtag.hdr.tag_len = htons((u_int16_t)sizeof(sp));
1404 			uniqtag.data.pointer = sp;
1405 			init_tags(sp);
1406 			insert_tag(sp, &neg->ac_name.hdr); /* AC_NAME */
1407 			if ((tag = get_tag(ph, PTT_SRV_NAME)))
1408 				insert_tag(sp, tag);	  /* return service */
1409 			/*
1410 			 * If we have a NULL service request
1411 			 * and have an extra service defined in this hook,
1412 			 * then also add a tag for the extra service.
1413 			 * XXX this is a hack. eventually we should be able
1414 			 * to support advertising many services, not just one
1415 			 */
1416 			if (((tag == NULL) || (tag->tag_len == 0))
1417 			&& (neg->service.hdr.tag_len != 0)) {
1418 				insert_tag(sp, &neg->service.hdr); /* SERVICE */
1419 			}
1420 			if ((tag = get_tag(ph, PTT_HOST_UNIQ)))
1421 				insert_tag(sp, tag); /* returned hostunique */
1422 			insert_tag(sp, &uniqtag.hdr);
1423 			scan_tags(sp, ph);
1424 			make_packet(sp);
1425 			sendpacket(sp);
1426 			break;
1427 
1428 		/*
1429 		 * Packets coming from the hook make no sense
1430 		 * to sessions in these states. Throw them away.
1431 		 */
1432 		case	PPPOE_SINIT:
1433 		case	PPPOE_SREQ:
1434 		case	PPPOE_SOFFER:
1435 		case	PPPOE_SNONE:
1436 		case	PPPOE_LISTENING:
1437 		case	PPPOE_DEAD:
1438 		default:
1439 			LEAVE(ENETUNREACH);
1440 		}
1441 	}
1442 quit:
1443 	if (item)
1444 		NG_FREE_ITEM(item);
1445 	NG_FREE_M(m);
1446 	return error;
1447 }
1448 
1449 /*
1450  * Do local shutdown processing..
1451  * If we are a persistant device, we might refuse to go away, and
1452  * we'd only remove our links and reset ourself.
1453  */
1454 static int
1455 ng_pppoe_shutdown(node_p node)
1456 {
1457 	const priv_p privdata = NG_NODE_PRIVATE(node);
1458 
1459 AAA
1460 	NG_NODE_SET_PRIVATE(node, NULL);
1461 	NG_NODE_UNREF(privdata->node);
1462 	FREE(privdata, M_NETGRAPH_PPPOE);
1463 	return (0);
1464 }
1465 
1466 /*
1467  * This is called once we've already connected a new hook to the other node.
1468  * It gives us a chance to balk at the last minute.
1469  */
1470 static int
1471 ng_pppoe_connect(hook_p hook)
1472 {
1473 	/* be really amiable and just say "YUP that's OK by me! " */
1474 	return (0);
1475 }
1476 
1477 /*
1478  * Hook disconnection
1479  *
1480  * Clean up all dangling links and information about the session/hook.
1481  * For this type, removal of the last link destroys the node
1482  */
1483 static int
1484 ng_pppoe_disconnect(hook_p hook)
1485 {
1486 	node_p node = NG_HOOK_NODE(hook);
1487 	priv_p privp = NG_NODE_PRIVATE(node);
1488 	sessp	sp;
1489 	int 	hooks;
1490 
1491 AAA
1492 	hooks = NG_NODE_NUMHOOKS(node); /* this one already not counted */
1493 	if (NG_HOOK_PRIVATE(hook) == &privp->debug_hook) {
1494 		privp->debug_hook = NULL;
1495 	} else if (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook) {
1496 		privp->ethernet_hook = NULL;
1497 		if (NG_NODE_IS_VALID(node))
1498 			ng_rmnode_self(node);
1499 	} else {
1500 		sp = NG_HOOK_PRIVATE(hook);
1501 		if (sp->state != PPPOE_SNONE ) {
1502 			pppoe_send_event(sp, NGM_PPPOE_CLOSE);
1503 		}
1504 		/*
1505 		 * According to the spec, if we are connected,
1506 		 * we should send a DISC packet if we are shutting down
1507 		 * a session.
1508 		 */
1509 		if ((privp->ethernet_hook)
1510 		&& ((sp->state == PPPOE_CONNECTED)
1511 		 || (sp->state == PPPOE_NEWCONNECTED))) {
1512 			struct mbuf *m;
1513 			struct pppoe_full_hdr *wh;
1514 			struct pppoe_tag *tag;
1515 			int	msglen = strlen(SIGNOFF);
1516 			int error = 0;
1517 
1518 			/* revert the stored header to DISC/PADT mode */
1519 		 	wh = &sp->pkt_hdr;
1520 			wh->ph.code = PADT_CODE;
1521 			if (nonstandard)
1522 				wh->eh.ether_type = ETHERTYPE_PPPOE_STUPID_DISC;
1523 			else
1524 				wh->eh.ether_type = ETHERTYPE_PPPOE_DISC;
1525 
1526 			/* generate a packet of that type */
1527 			MGETHDR(m, M_DONTWAIT, MT_DATA);
1528 			if(m == NULL)
1529 				printf("pppoe: Session out of mbufs\n");
1530 			else {
1531 				m->m_pkthdr.rcvif = NULL;
1532 				m->m_pkthdr.len = m->m_len = sizeof(*wh);
1533 				bcopy((caddr_t)wh, mtod(m, caddr_t),
1534 				    sizeof(*wh));
1535 				/*
1536 				 * Add a General error message and adjust
1537 				 * sizes
1538 				 */
1539 				wh = mtod(m, struct pppoe_full_hdr *);
1540 				tag = wh->ph.tag;
1541 				tag->tag_type = PTT_GEN_ERR;
1542 				tag->tag_len = htons((u_int16_t)msglen);
1543 				strncpy(tag->tag_data, SIGNOFF, msglen);
1544 				m->m_pkthdr.len = (m->m_len += sizeof(*tag) +
1545 				    msglen);
1546 				wh->ph.length = htons(sizeof(*tag) + msglen);
1547 				NG_SEND_DATA_ONLY(error,
1548 					privp->ethernet_hook, m);
1549 			}
1550 		}
1551 		/*
1552 		 * As long as we have somewhere to store the timeout handle,
1553 		 * we may have a timeout pending.. get rid of it.
1554 		 */
1555 		if (sp->neg) {
1556 			untimeout(pppoe_ticker, hook, sp->neg->timeout_handle);
1557 			if (sp->neg->m)
1558 				m_freem(sp->neg->m);
1559 			FREE(sp->neg, M_NETGRAPH_PPPOE);
1560 		}
1561 		FREE(sp, M_NETGRAPH_PPPOE);
1562 		NG_HOOK_SET_PRIVATE(hook, NULL);
1563 		/* work out how many session hooks there are */
1564 		/* Node goes away on last session hook removal */
1565 		if (privp->ethernet_hook) hooks -= 1;
1566 		if (privp->debug_hook) hooks -= 1;
1567 	}
1568 	if ((NG_NODE_NUMHOOKS(node) == 0)
1569 	&& (NG_NODE_IS_VALID(node)))
1570 		ng_rmnode_self(node);
1571 	return (0);
1572 }
1573 
1574 /*
1575  * timeouts come here.
1576  */
1577 static void
1578 pppoe_ticker(void *arg)
1579 {
1580 	int s = splnet();
1581 	hook_p hook = arg;
1582 	sessp	sp = NG_HOOK_PRIVATE(hook);
1583 	negp	neg = sp->neg;
1584 	int	error = 0;
1585 	struct mbuf *m0 = NULL;
1586 	priv_p privp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
1587 
1588 AAA
1589 	switch(sp->state) {
1590 		/*
1591 		 * resend the last packet, using an exponential backoff.
1592 		 * After a period of time, stop growing the backoff,
1593 		 * and either leave it, or revert to the start.
1594 		 */
1595 	case	PPPOE_SINIT:
1596 	case	PPPOE_SREQ:
1597 		/* timeouts on these produce resends */
1598 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1599 		NG_SEND_DATA_ONLY( error, privp->ethernet_hook, m0);
1600 		neg->timeout_handle = timeout(pppoe_ticker,
1601 					hook, neg->timeout * hz);
1602 		if ((neg->timeout <<= 1) > PPPOE_TIMEOUT_LIMIT) {
1603 			if (sp->state == PPPOE_SREQ) {
1604 				/* revert to SINIT mode */
1605 				pppoe_start(sp);
1606 			} else {
1607 				neg->timeout = PPPOE_TIMEOUT_LIMIT;
1608 			}
1609 		}
1610 		break;
1611 	case	PPPOE_PRIMED:
1612 	case	PPPOE_SOFFER:
1613 		/* a timeout on these says "give up" */
1614 		ng_rmhook_self(hook);
1615 		break;
1616 	default:
1617 		/* timeouts have no meaning in other states */
1618 		printf("pppoe: unexpected timeout\n");
1619 	}
1620 	splx(s);
1621 }
1622 
1623 
1624 static void
1625 sendpacket(sessp sp)
1626 {
1627 	int	error = 0;
1628 	struct mbuf *m0 = NULL;
1629 	hook_p hook = sp->hook;
1630 	negp	neg = sp->neg;
1631 	priv_p	privp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
1632 
1633 AAA
1634 	switch(sp->state) {
1635 	case	PPPOE_LISTENING:
1636 	case	PPPOE_DEAD:
1637 	case	PPPOE_SNONE:
1638 	case	PPPOE_CONNECTED:
1639 		printf("pppoe: sendpacket: unexpected state\n");
1640 		break;
1641 
1642 	case	PPPOE_NEWCONNECTED:
1643 		/* send the PADS without a timeout - we're now connected */
1644 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1645 		NG_SEND_DATA_ONLY( error, privp->ethernet_hook, m0);
1646 		break;
1647 
1648 	case	PPPOE_PRIMED:
1649 		/* No packet to send, but set up the timeout */
1650 		neg->timeout_handle = timeout(pppoe_ticker,
1651 					hook, PPPOE_OFFER_TIMEOUT * hz);
1652 		break;
1653 
1654 	case	PPPOE_SOFFER:
1655 		/*
1656 		 * send the offer but if they don't respond
1657 		 * in PPPOE_OFFER_TIMEOUT seconds, forget about it.
1658 		 */
1659 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1660 		NG_SEND_DATA_ONLY( error, privp->ethernet_hook, m0);
1661 		neg->timeout_handle = timeout(pppoe_ticker,
1662 					hook, PPPOE_OFFER_TIMEOUT * hz);
1663 		break;
1664 
1665 	case	PPPOE_SINIT:
1666 	case	PPPOE_SREQ:
1667 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1668 		NG_SEND_DATA_ONLY( error, privp->ethernet_hook, m0);
1669 		neg->timeout_handle = timeout(pppoe_ticker, hook,
1670 					(hz * PPPOE_INITIAL_TIMEOUT));
1671 		neg->timeout = PPPOE_INITIAL_TIMEOUT * 2;
1672 		break;
1673 
1674 	default:
1675 		error = EINVAL;
1676 		printf("pppoe: timeout: bad state\n");
1677 	}
1678 	/* return (error); */
1679 }
1680 
1681 /*
1682  * Parse an incoming packet to see if any tags should be copied to the
1683  * output packet. Don't do any tags that have been handled in the main
1684  * state machine.
1685  */
1686 static const struct pppoe_tag*
1687 scan_tags(sessp	sp, const struct pppoe_hdr* ph)
1688 {
1689 	const char *const end = (const char *)next_tag(ph);
1690 	const char *ptn;
1691 	const struct pppoe_tag *pt = &ph->tag[0];
1692 	/*
1693 	 * Keep processing tags while a tag header will still fit.
1694 	 */
1695 AAA
1696 	while((const char*)(pt + 1) <= end) {
1697 		/*
1698 		 * If the tag data would go past the end of the packet, abort.
1699 		 */
1700 		ptn = (((const char *)(pt + 1)) + ntohs(pt->tag_len));
1701 		if(ptn > end)
1702 			return NULL;
1703 
1704 		switch (pt->tag_type) {
1705 		case	PTT_RELAY_SID:
1706 			insert_tag(sp, pt);
1707 			break;
1708 		case	PTT_EOL:
1709 			return NULL;
1710 		case	PTT_SRV_NAME:
1711 		case	PTT_AC_NAME:
1712 		case	PTT_HOST_UNIQ:
1713 		case	PTT_AC_COOKIE:
1714 		case	PTT_VENDOR:
1715 		case	PTT_SRV_ERR:
1716 		case	PTT_SYS_ERR:
1717 		case	PTT_GEN_ERR:
1718 			break;
1719 		}
1720 		pt = (const struct pppoe_tag*)ptn;
1721 	}
1722 	return NULL;
1723 }
1724 
1725 static	int
1726 pppoe_send_event(sessp sp, enum cmd cmdid)
1727 {
1728 	int error;
1729 	struct ng_mesg *msg;
1730 	struct ngpppoe_sts *sts;
1731 
1732 AAA
1733 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, cmdid,
1734 			sizeof(struct ngpppoe_sts), M_NOWAIT);
1735 	if (msg == NULL)
1736 		return (ENOMEM);
1737 	sts = (struct ngpppoe_sts *)msg->data;
1738 	strncpy(sts->hook, NG_HOOK_NAME(sp->hook), NG_HOOKLEN + 1);
1739 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, NULL);
1740 	return (error);
1741 }
1742