xref: /freebsd/sys/netgraph/ng_pppoe.c (revision 6b806d21d144c25f4fad714e1c0cf780f5e27d7e)
1 /*
2  * ng_pppoe.c
3  */
4 
5 /*-
6  * Copyright (c) 1996-1999 Whistle Communications, Inc.
7  * All rights reserved.
8  *
9  * Subject to the following obligations and disclaimer of warranty, use and
10  * redistribution of this software, in source or object code forms, with or
11  * without modifications are expressly permitted by Whistle Communications;
12  * provided, however, that:
13  * 1. Any and all reproductions of the source or object code must include the
14  *    copyright notice above and the following disclaimer of warranties; and
15  * 2. No rights are granted, in any manner or form, to use Whistle
16  *    Communications, Inc. trademarks, including the mark "WHISTLE
17  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
18  *    such appears in the above copyright notice or in the software.
19  *
20  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
21  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
22  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
23  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
24  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
25  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
26  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
27  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
28  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
29  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
30  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
31  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
32  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
36  * OF SUCH DAMAGE.
37  *
38  * Author: Julian Elischer <julian@freebsd.org>
39  *
40  * $FreeBSD$
41  * $Whistle: ng_pppoe.c,v 1.10 1999/11/01 09:24:52 julian Exp $
42  */
43 #if 0
44 #define	DBG do { printf("ng_device: %s\n", __func__ ); } while (0)
45 #else
46 #define	DBG do {} while (0)
47 #endif
48 
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/kernel.h>
52 #include <sys/mbuf.h>
53 #include <sys/malloc.h>
54 #include <sys/errno.h>
55 #include <sys/sysctl.h>
56 #include <sys/syslog.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 	{
154 	  NGM_PPPOE_COOKIE,
155 	  NGM_PPPOE_SETMODE,
156 	  "pppoe_setmode",
157 	  &ng_parse_string_type,
158 	  NULL
159 	},
160 	{
161 	  NGM_PPPOE_COOKIE,
162 	  NGM_PPPOE_GETMODE,
163 	  "pppoe_getmode",
164 	  NULL,
165 	  &ng_parse_string_type
166 	},
167 	{ 0 }
168 };
169 
170 /* Netgraph node type descriptor */
171 static struct ng_type typestruct = {
172 	.version =	NG_ABI_VERSION,
173 	.name =		NG_PPPOE_NODE_TYPE,
174 	.constructor =	ng_pppoe_constructor,
175 	.rcvmsg =	ng_pppoe_rcvmsg,
176 	.shutdown =	ng_pppoe_shutdown,
177 	.newhook =	ng_pppoe_newhook,
178 	.connect =	ng_pppoe_connect,
179 	.rcvdata =	ng_pppoe_rcvdata,
180 	.disconnect =	ng_pppoe_disconnect,
181 	.cmdlist =	ng_pppoe_cmds,
182 };
183 NETGRAPH_INIT(pppoe, &typestruct);
184 /* Depend on ng_ether so we can use the Ethernet parse type */
185 MODULE_DEPEND(ng_pppoe, ng_ether, 1, 1, 1);
186 
187 /*
188  * States for the session state machine.
189  * These have no meaning if there is no hook attached yet.
190  */
191 enum state {
192     PPPOE_SNONE=0,	/* [both] Initial state */
193     PPPOE_LISTENING,	/* [Daemon] Listening for discover initiation pkt */
194     PPPOE_SINIT,	/* [Client] Sent discovery initiation */
195     PPPOE_PRIMED,	/* [Server] Awaiting PADI from daemon */
196     PPPOE_SOFFER,	/* [Server] Sent offer message  (got PADI)*/
197     PPPOE_SREQ,		/* [Client] Sent a Request */
198     PPPOE_NEWCONNECTED,	/* [Server] Connection established, No data received */
199     PPPOE_CONNECTED,	/* [Both] Connection established, Data received */
200     PPPOE_DEAD		/* [Both] */
201 };
202 
203 #define NUMTAGS 20 /* number of tags we are set up to work with */
204 
205 /*
206  * Information we store for each hook on each node for negotiating the
207  * session. The mbuf and cluster are freed once negotiation has completed.
208  * The whole negotiation block is then discarded.
209  */
210 
211 struct sess_neg {
212 	struct mbuf 		*m; /* holds cluster with last sent packet */
213 	union	packet		*pkt; /* points within the above cluster */
214 	struct callout		handle;   /* see timeout(9) */
215 	u_int			timeout; /* 0,1,2,4,8,16 etc. seconds */
216 	u_int			numtags;
217 	const struct pppoe_tag	*tags[NUMTAGS];
218 	u_int			service_len;
219 	u_int			ac_name_len;
220 
221 	struct datatag		service;
222 	struct datatag		ac_name;
223 };
224 typedef struct sess_neg *negp;
225 
226 /*
227  * Session information that is needed after connection.
228  */
229 struct sess_con {
230 	hook_p  		hook;
231 	u_int16_t		Session_ID;
232 	enum state		state;
233 	ng_ID_t			creator;		/* who to notify */
234 	struct pppoe_full_hdr	pkt_hdr;	/* used when connected */
235 	negp			neg;		/* used when negotiating */
236 	/*struct sess_con	*hash_next;*/	/* not yet used */
237 };
238 typedef struct sess_con *sessp;
239 
240 #define	NG_PPPOE_SESSION_NODE(sp) NG_HOOK_NODE(sp->hook)
241 
242 enum {
243 	PPPOE_STANDARD	= 1,	/* standard RFC2516 mode */
244 	PPPOE_NONSTANDARD,	/* 3Com proprietary mode */
245 };
246 
247 struct ng_pppoe_mode_t {
248 	u_int8_t        		id;
249 	const struct ether_header	*eh_prototype;
250 	const char      		*name;
251 };
252 
253 static const struct ether_header eh_standard =
254 	{{0xff,0xff,0xff,0xff,0xff,0xff},
255 	{0x00,0x00,0x00,0x00,0x00,0x00},
256 	ETHERTYPE_PPPOE_DISC};
257 
258 static const struct ether_header eh_3Com =
259 	{{0xff,0xff,0xff,0xff,0xff,0xff},
260 	{0x00,0x00,0x00,0x00,0x00,0x00},
261 	ETHERTYPE_PPPOE_STUPID_DISC};
262 
263 static const struct ng_pppoe_mode_t ng_pppoe_modes[] = {
264 	{ PPPOE_STANDARD,	&eh_standard,	NG_PPPOE_STANDARD },
265 	{ PPPOE_NONSTANDARD,	&eh_3Com,	NG_PPPOE_NONSTANDARD },
266 	{ 0, NULL},
267 };
268 
269 /*
270  * Information we store for each node
271  */
272 struct PPPOE {
273 	node_p		node;		/* back pointer to node */
274 	hook_p  	ethernet_hook;
275 	hook_p  	debug_hook;
276 	u_int   	packets_in;	/* packets in from ethernet */
277 	u_int   	packets_out;	/* packets out towards ethernet */
278 	u_int32_t	flags;
279 	const struct ng_pppoe_mode_t	*mode;	/* standard PPPoE or 3Com? */
280 	/*struct sess_con *buckets[HASH_SIZE];*/	/* not yet used */
281 };
282 typedef struct PPPOE *priv_p;
283 
284 /* Deprecated sysctl, leaved here to keep compatibility for some time */
285 #define PPPOE_SYSCTL_KEEPSTANDARD	-1
286 #define PPPOE_SYSCTL_STANDARD		0
287 #define PPPOE_SYSCTL_NONSTANDARD	1
288 static int pppoe_mode = PPPOE_SYSCTL_KEEPSTANDARD;
289 static const struct ng_pppoe_mode_t *sysctl_mode = ng_pppoe_modes;
290 
291 static int
292 ngpppoe_set_ethertype(SYSCTL_HANDLER_ARGS)
293 {
294 	int error;
295 	int val;
296 
297 	val = pppoe_mode;
298 	error = sysctl_handle_int(oidp, &val, sizeof(int), req);
299 	if (error != 0 || req->newptr == NULL)
300 		return (error);
301 	switch (val) {
302 	case PPPOE_SYSCTL_NONSTANDARD:
303 		sysctl_mode = ng_pppoe_modes + 1;
304 		break;
305 	case PPPOE_SYSCTL_STANDARD:
306 	case PPPOE_SYSCTL_KEEPSTANDARD:
307 		sysctl_mode = ng_pppoe_modes;
308 		break;
309 	default:
310 		return (EINVAL);
311 	}
312 
313 	pppoe_mode = val;
314 	printf("net.graph.nonstandard_pppoe is deprecated. See ng_pppoe(4), ppp(8).\n");
315 	return (0);
316 }
317 
318 SYSCTL_PROC(_net_graph, OID_AUTO, nonstandard_pppoe, CTLTYPE_INT | CTLFLAG_RW,
319     0, sizeof(int), ngpppoe_set_ethertype, "I", "select normal or stupid ISP");
320 
321 union uniq {
322 	char bytes[sizeof(void *)];
323 	void * pointer;
324 	};
325 
326 #define	LEAVE(x) do { error = x; goto quit; } while(0)
327 static void	pppoe_start(sessp sp);
328 static void	sendpacket(sessp sp);
329 static void	pppoe_ticker(node_p node, hook_p hook, void *arg1, int arg2);
330 static const	struct pppoe_tag *scan_tags(sessp sp,
331 			const struct pppoe_hdr* ph);
332 static	int	pppoe_send_event(sessp sp, enum cmd cmdid);
333 
334 /*************************************************************************
335  * Some basic utilities  from the Linux version with author's permission.*
336  * Author:	Michal Ostrowski <mostrows@styx.uwaterloo.ca>		 *
337  ************************************************************************/
338 
339 /*
340  * Generate a new session id
341  * XXX find out the FreeBSD locking scheme.
342  */
343 static u_int16_t
344 get_new_sid(node_p node)
345 {
346 	static int pppoe_sid = 10;
347 	sessp sp;
348 	hook_p	hook;
349 	u_int16_t val;
350 	priv_p privp = NG_NODE_PRIVATE(node);
351 
352 	DBG;
353 restart:
354 	val = pppoe_sid++;
355 	/*
356 	 * Spec says 0xFFFF is reserved.
357 	 * Also don't use 0x0000
358 	 */
359 	if (val == 0xffff) {
360 		pppoe_sid = 20;
361 		goto restart;
362 	}
363 
364 	/* Check it isn't already in use */
365 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
366 		/* don't check special hooks */
367 		if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook)
368 		||  (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook))
369 			continue;
370 		sp = NG_HOOK_PRIVATE(hook);
371 		if (sp->Session_ID == val)
372 			goto restart;
373 	}
374 
375 	return val;
376 }
377 
378 
379 /*
380  * Return the location where the next tag can be put
381  */
382 static __inline const struct pppoe_tag*
383 next_tag(const struct pppoe_hdr* ph)
384 {
385 	return (const struct pppoe_tag*)(((const char*)&ph->tag[0])
386 	    + ntohs(ph->length));
387 }
388 
389 /*
390  * Look for a tag of a specific type
391  * Don't trust any length the other end says.
392  * but assume we already sanity checked ph->length.
393  */
394 static const struct pppoe_tag*
395 get_tag(const struct pppoe_hdr* ph, u_int16_t idx)
396 {
397 	const char *const end = (const char *)next_tag(ph);
398 	const char *ptn;
399 	const struct pppoe_tag *pt = &ph->tag[0];
400 	/*
401 	 * Keep processing tags while a tag header will still fit.
402 	 */
403 	DBG;
404 	while((const char*)(pt + 1) <= end) {
405 	    /*
406 	     * If the tag data would go past the end of the packet, abort.
407 	     */
408 	    ptn = (((const char *)(pt + 1)) + ntohs(pt->tag_len));
409 	    if(ptn > end)
410 		return NULL;
411 
412 	    if(pt->tag_type == idx)
413 		return pt;
414 
415 	    pt = (const struct pppoe_tag*)ptn;
416 	}
417 	return NULL;
418 }
419 
420 /**************************************************************************
421  * inlines to initialise or add tags to a session's tag list,
422  **************************************************************************/
423 /*
424  * Initialise the session's tag list
425  */
426 static void
427 init_tags(sessp sp)
428 {
429 	DBG;
430 	if(sp->neg == NULL) {
431 		printf("pppoe: asked to init NULL neg pointer\n");
432 		return;
433 	}
434 	sp->neg->numtags = 0;
435 }
436 
437 static void
438 insert_tag(sessp sp, const struct pppoe_tag *tp)
439 {
440 	int	i;
441 	negp neg;
442 
443 	DBG;
444 	if((neg = sp->neg) == NULL) {
445 		printf("pppoe: asked to use NULL neg pointer\n");
446 		return;
447 	}
448 	if ((i = neg->numtags++) < NUMTAGS) {
449 		neg->tags[i] = tp;
450 	} else {
451 		printf("pppoe: asked to add too many tags to packet\n");
452 		neg->numtags--;
453 	}
454 }
455 
456 /*
457  * Make up a packet, using the tags filled out for the session.
458  *
459  * Assume that the actual pppoe header and ethernet header
460  * are filled out externally to this routine.
461  * Also assume that neg->wh points to the correct
462  * location at the front of the buffer space.
463  */
464 static void
465 make_packet(sessp sp) {
466 	struct pppoe_full_hdr *wh = &sp->neg->pkt->pkt_header;
467 	const struct pppoe_tag **tag;
468 	char *dp;
469 	int count;
470 	int tlen;
471 	u_int16_t length = 0;
472 
473 	DBG;
474 	if ((sp->neg == NULL) || (sp->neg->m == NULL)) {
475 		printf("pppoe: make_packet called from wrong state\n");
476 	}
477 	dp = (char *)wh->ph.tag;
478 	for (count = 0, tag = sp->neg->tags;
479 	    ((count < sp->neg->numtags) && (count < NUMTAGS));
480 	    tag++, count++) {
481 		tlen = ntohs((*tag)->tag_len) + sizeof(**tag);
482 		if ((length + tlen) > (ETHER_MAX_LEN - 4 - sizeof(*wh))) {
483 			printf("pppoe: tags too long\n");
484 			sp->neg->numtags = count;
485 			break;	/* XXX chop off what's too long */
486 		}
487 		bcopy(*tag, (char *)dp, tlen);
488 		length += tlen;
489 		dp += tlen;
490 	}
491  	wh->ph.length = htons(length);
492 	sp->neg->m->m_len = length + sizeof(*wh);
493 	sp->neg->m->m_pkthdr.len = length + sizeof(*wh);
494 }
495 
496 /**************************************************************************
497  * Routine to match a service offered					  *
498  **************************************************************************/
499 /*
500  * Find a hook that has a service string that matches that
501  * we are seeking. for now use a simple string.
502  * In the future we may need something like regexp().
503  * for testing allow a null string to match 1st found and a null service
504  * to match all requests. Also make '*' do the same.
505  */
506 
507 #define NG_MATCH_EXACT	1
508 #define NG_MATCH_ANY	2
509 
510 static hook_p
511 pppoe_match_svc(node_p node, const char *svc_name, int svc_len, int match)
512 {
513 	sessp	sp	= NULL;
514 	negp	neg	= NULL;
515 	priv_p	privp	= NG_NODE_PRIVATE(node);
516 	hook_p	allhook	= NULL;
517 	hook_p	hook;
518 
519 	DBG;
520 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
521 
522 		/* skip any hook that is debug or ethernet */
523 		if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook)
524 		||  (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook))
525 			continue;
526 		sp = NG_HOOK_PRIVATE(hook);
527 
528 		/* Skip any sessions which are not in LISTEN mode. */
529 		if ( sp->state != PPPOE_LISTENING)
530 			continue;
531 
532 		neg = sp->neg;
533 
534 		/* Special case for a blank or "*" service name (wildcard) */
535 		if (match == NG_MATCH_ANY && neg->service_len == 1 &&
536 		    neg->service.data[0] == '*') {
537 			allhook = hook;
538 			continue;
539 		}
540 
541 		/* If the lengths don't match, that aint it. */
542 		if (neg->service_len != svc_len)
543 			continue;
544 
545 		/* An exact match? */
546 		if (svc_len == 0)
547 			break;
548 
549 		if (strncmp(svc_name, neg->service.data, svc_len) == 0)
550 			break;
551 	}
552 	return (hook ? hook : allhook);
553 }
554 /**************************************************************************
555  * Routine to find a particular session that matches an incoming packet	  *
556  **************************************************************************/
557 static hook_p
558 pppoe_findsession(node_p node, const struct pppoe_full_hdr *wh)
559 {
560 	sessp	sp = NULL;
561 	hook_p hook = NULL;
562 	priv_p	privp = NG_NODE_PRIVATE(node);
563 	u_int16_t	session = ntohs(wh->ph.sid);
564 
565 	/*
566 	 * find matching peer/session combination.
567 	 */
568 	DBG;
569 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
570 		/* don't check special hooks */
571 		if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook)
572 		||  (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook)) {
573 			continue;
574 		}
575 		sp = NG_HOOK_PRIVATE(hook);
576 		if ( ( (sp->state == PPPOE_CONNECTED)
577 		    || (sp->state == PPPOE_NEWCONNECTED) )
578 		&& (sp->Session_ID == session)
579 		&& (bcmp(sp->pkt_hdr.eh.ether_dhost,
580 		    wh->eh.ether_shost,
581 		    ETHER_ADDR_LEN)) == 0) {
582 			break;
583 		}
584 	}
585 	return (hook);
586 }
587 
588 static hook_p
589 pppoe_finduniq(node_p node, const struct pppoe_tag *tag)
590 {
591 	hook_p hook = NULL;
592 	priv_p	privp = NG_NODE_PRIVATE(node);
593 	union uniq		uniq;
594 
595 	DBG;
596 	bcopy(tag->tag_data, uniq.bytes, sizeof(void *));
597 	/* cycle through all known hooks */
598 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
599 		/* don't check special hooks */
600 		if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook)
601 		||  (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook))
602 			continue;
603 		if (uniq.pointer == NG_HOOK_PRIVATE(hook))
604 			break;
605 	}
606 	return (hook);
607 }
608 
609 /**************************************************************************
610  * start of Netgraph entrypoints					  *
611  **************************************************************************/
612 
613 /*
614  * Allocate the private data structure and the generic node
615  * and link them together.
616  *
617  * ng_make_node_common() returns with a generic node struct
618  * with a single reference for us.. we transfer it to the
619  * private structure.. when we free the private struct we must
620  * unref the node so it gets freed too.
621  */
622 static int
623 ng_pppoe_constructor(node_p node)
624 {
625 	priv_p privdata;
626 
627 	DBG;
628 	/* Initialize private descriptor */
629 	MALLOC(privdata, priv_p, sizeof(*privdata), M_NETGRAPH_PPPOE,
630 	    M_NOWAIT | M_ZERO);
631 	if (privdata == NULL)
632 		return (ENOMEM);
633 
634 	/* Link structs together; this counts as our one reference to *nodep */
635 	NG_NODE_SET_PRIVATE(node, privdata);
636 	privdata->node = node;
637 
638 	/* Initialize to standard mode (the first one in ng_pppoe_modes[]). */
639 	privdata->mode = sysctl_mode;
640 
641 	return (0);
642 }
643 
644 /*
645  * Give our ok for a hook to be added...
646  * point the hook's private info to the hook structure.
647  *
648  * The following hook names are special:
649  *  Ethernet:  the hook that should be connected to a NIC.
650  *  debug:	copies of data sent out here  (when I write the code).
651  * All other hook names need only be unique. (the framework checks this).
652  */
653 static int
654 ng_pppoe_newhook(node_p node, hook_p hook, const char *name)
655 {
656 	const priv_p privp = NG_NODE_PRIVATE(node);
657 	sessp sp;
658 
659 	DBG;
660 	if (strcmp(name, NG_PPPOE_HOOK_ETHERNET) == 0) {
661 		privp->ethernet_hook = hook;
662 		NG_HOOK_SET_PRIVATE(hook, &privp->ethernet_hook);
663 	} else if (strcmp(name, NG_PPPOE_HOOK_DEBUG) == 0) {
664 		privp->debug_hook = hook;
665 		NG_HOOK_SET_PRIVATE(hook, &privp->debug_hook);
666 	} else {
667 		/*
668 		 * Any other unique name is OK.
669 		 * The infrastructure has already checked that it's unique,
670 		 * so just allocate it and hook it in.
671 		 */
672 		MALLOC(sp, sessp, sizeof(*sp), M_NETGRAPH_PPPOE, M_NOWAIT | M_ZERO);
673 		if (sp == NULL) {
674 				return (ENOMEM);
675 		}
676 
677 		NG_HOOK_SET_PRIVATE(hook, sp);
678 		sp->hook = hook;
679 	}
680 	return(0);
681 }
682 
683 /*
684  * Get a netgraph control message.
685  * Check it is one we understand. If needed, send a response.
686  * We sometimes save the address for an async action later.
687  * Always free the message.
688  */
689 static int
690 ng_pppoe_rcvmsg(node_p node, item_p item, hook_p lasthook)
691 {
692 	priv_p privp = NG_NODE_PRIVATE(node);
693 	struct ngpppoe_init_data *ourmsg = NULL;
694 	struct ng_mesg *resp = NULL;
695 	int error = 0;
696 	hook_p hook = NULL;
697 	sessp sp = NULL;
698 	negp neg = NULL;
699 	struct ng_mesg *msg;
700 
701 	DBG;
702 	NGI_GET_MSG(item, msg);
703 	/* Deal with message according to cookie and command */
704 	switch (msg->header.typecookie) {
705 	case NGM_PPPOE_COOKIE:
706 		switch (msg->header.cmd) {
707 		case NGM_PPPOE_CONNECT:
708 		case NGM_PPPOE_LISTEN:
709 		case NGM_PPPOE_OFFER:
710 		case NGM_PPPOE_SERVICE:
711 			ourmsg = (struct ngpppoe_init_data *)msg->data;
712 			if (msg->header.arglen < sizeof(*ourmsg)) {
713 				printf("pppoe: init data too small\n");
714 				LEAVE(EMSGSIZE);
715 			}
716 			if (msg->header.arglen - sizeof(*ourmsg) >
717 			    PPPOE_SERVICE_NAME_SIZE) {
718 				printf("pppoe_rcvmsg: service name too big");
719 				LEAVE(EMSGSIZE);
720 			}
721 			if (msg->header.arglen - sizeof(*ourmsg) <
722 			    ourmsg->data_len) {
723 				printf("pppoe: init data has bad length,"
724 				    " %d should be %zd\n", ourmsg->data_len,
725 				    msg->header.arglen - sizeof (*ourmsg));
726 				LEAVE(EMSGSIZE);
727 			}
728 
729 			/* make sure strcmp will terminate safely */
730 			ourmsg->hook[sizeof(ourmsg->hook) - 1] = '\0';
731 
732 			/* cycle through all known hooks */
733 			LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
734 				if (NG_HOOK_NAME(hook)
735 				&& strcmp(NG_HOOK_NAME(hook), ourmsg->hook) == 0)
736 					break;
737 			}
738 			if (hook == NULL) {
739 				LEAVE(ENOENT);
740 			}
741 			if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook)
742 			||  (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook)) {
743 				LEAVE(EINVAL);
744 			}
745 			sp = NG_HOOK_PRIVATE(hook);
746 
747 			if (msg->header.cmd == NGM_PPPOE_LISTEN) {
748 				/*
749 				 * Ensure we aren't already listening for this
750 				 * service.
751 				 */
752 				if (pppoe_match_svc(node, ourmsg->data,
753 				    ourmsg->data_len, NG_MATCH_EXACT) != NULL) {
754 					LEAVE(EEXIST);
755 				}
756 			}
757 
758 			/*
759 			 * PPPOE_SERVICE advertisments are set up
760 			 * on sessions that are in PRIMED state.
761 			 */
762 			if (msg->header.cmd == NGM_PPPOE_SERVICE) {
763 				break;
764 			}
765 			if (sp->state |= PPPOE_SNONE) {
766 				printf("pppoe: Session already active\n");
767 				LEAVE(EISCONN);
768 			}
769 
770 			/*
771 			 * set up prototype header
772 			 */
773 			MALLOC(neg, negp, sizeof(*neg), M_NETGRAPH_PPPOE,
774 			    M_NOWAIT | M_ZERO);
775 
776 			if (neg == NULL) {
777 				printf("pppoe: Session out of memory\n");
778 				LEAVE(ENOMEM);
779 			}
780 			MGETHDR(neg->m, M_DONTWAIT, MT_DATA);
781 			if(neg->m == NULL) {
782 				printf("pppoe: Session out of mbufs\n");
783 				FREE(neg, M_NETGRAPH_PPPOE);
784 				LEAVE(ENOBUFS);
785 			}
786 			neg->m->m_pkthdr.rcvif = NULL;
787 			MCLGET(neg->m, M_DONTWAIT);
788 			if ((neg->m->m_flags & M_EXT) == 0) {
789 				printf("pppoe: Session out of mcls\n");
790 				m_freem(neg->m);
791 				FREE(neg, M_NETGRAPH_PPPOE);
792 				LEAVE(ENOBUFS);
793 			}
794 			sp->neg = neg;
795 			ng_callout_init(&neg->handle);
796 			neg->m->m_len = sizeof(struct pppoe_full_hdr);
797 			neg->pkt = mtod(neg->m, union packet*);
798 			memcpy((void *)&neg->pkt->pkt_header.eh,
799 			    (const void *)privp->mode->eh_prototype,
800 			    sizeof(struct ether_header));
801 			neg->pkt->pkt_header.ph.ver = 0x1;
802 			neg->pkt->pkt_header.ph.type = 0x1;
803 			neg->pkt->pkt_header.ph.sid = 0x0000;
804 			neg->timeout = 0;
805 
806 			sp->creator = NGI_RETADDR(item);
807 		}
808 		switch (msg->header.cmd) {
809 		case NGM_PPPOE_GET_STATUS:
810 		    {
811 			struct ngpppoestat *stats;
812 
813 			NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT);
814 			if (!resp) {
815 				LEAVE(ENOMEM);
816 			}
817 			stats = (struct ngpppoestat *) resp->data;
818 			stats->packets_in = privp->packets_in;
819 			stats->packets_out = privp->packets_out;
820 			break;
821 		    }
822 		case NGM_PPPOE_CONNECT:
823 			/*
824 			 * Check the hook exists and is Uninitialised.
825 			 * Send a PADI request, and start the timeout logic.
826 			 * Store the originator of this message so we can send
827 			 * a success of fail message to them later.
828 			 * Move the session to SINIT
829 			 * Set up the session to the correct state and
830 			 * start it.
831 			 */
832 			neg->service.hdr.tag_type = PTT_SRV_NAME;
833 			neg->service.hdr.tag_len =
834 			    htons((u_int16_t)ourmsg->data_len);
835 			if (ourmsg->data_len)
836 				bcopy(ourmsg->data, neg->service.data,
837 				    ourmsg->data_len);
838 			neg->service_len = ourmsg->data_len;
839 			pppoe_start(sp);
840 			break;
841 		case NGM_PPPOE_LISTEN:
842 			/*
843 			 * Check the hook exists and is Uninitialised.
844 			 * Install the service matching string.
845 			 * Store the originator of this message so we can send
846 			 * a success of fail message to them later.
847 			 * Move the hook to 'LISTENING'
848 			 */
849 			neg->service.hdr.tag_type = PTT_SRV_NAME;
850 			neg->service.hdr.tag_len =
851 			    htons((u_int16_t)ourmsg->data_len);
852 
853 			if (ourmsg->data_len)
854 				bcopy(ourmsg->data, neg->service.data,
855 				    ourmsg->data_len);
856 			neg->service_len = ourmsg->data_len;
857 			neg->pkt->pkt_header.ph.code = PADT_CODE;
858 			/*
859 			 * wait for PADI packet coming from ethernet
860 			 */
861 			sp->state = PPPOE_LISTENING;
862 			break;
863 		case NGM_PPPOE_OFFER:
864 			/*
865 			 * Check the hook exists and is Uninitialised.
866 			 * Store the originator of this message so we can send
867 			 * a success of fail message to them later.
868 			 * Store the AC-Name given and go to PRIMED.
869 			 */
870 			neg->ac_name.hdr.tag_type = PTT_AC_NAME;
871 			neg->ac_name.hdr.tag_len =
872 			    htons((u_int16_t)ourmsg->data_len);
873 			if (ourmsg->data_len)
874 				bcopy(ourmsg->data, neg->ac_name.data,
875 				    ourmsg->data_len);
876 			neg->ac_name_len = ourmsg->data_len;
877 			neg->pkt->pkt_header.ph.code = PADO_CODE;
878 			/*
879 			 * Wait for PADI packet coming from hook
880 			 */
881 			sp->state = PPPOE_PRIMED;
882 			break;
883 		case NGM_PPPOE_SERVICE:
884 			/*
885 			 * Check the session is primed.
886 			 * for now just allow ONE service to be advertised.
887 			 * If you do it twice you just overwrite.
888 			 */
889 			if (sp->state != PPPOE_PRIMED) {
890 				printf("pppoe: Session not primed\n");
891 				LEAVE(EISCONN);
892 			}
893 			neg = sp->neg;
894 			neg->service.hdr.tag_type = PTT_SRV_NAME;
895 			neg->service.hdr.tag_len =
896 			    htons((u_int16_t)ourmsg->data_len);
897 
898 			if (ourmsg->data_len)
899 				bcopy(ourmsg->data, neg->service.data,
900 				    ourmsg->data_len);
901 			neg->service_len = ourmsg->data_len;
902 			break;
903 		case NGM_PPPOE_SETMODE:
904 		    {
905 			const struct ng_pppoe_mode_t *mode;
906 			char *s;
907 			size_t len;
908 
909 			if (msg->header.arglen == 0)
910 				LEAVE(EINVAL);
911 
912 			s = (char *)msg->data;
913 			len = msg->header.arglen - 1;
914 
915 			/* Search for matching mode string */
916 			for (mode = ng_pppoe_modes; mode->id != 0; mode++ )
917 				if ((strlen(mode->name) == len) &&
918 				    !strncmp(mode->name, s, len))
919 					break;	/* found */
920 
921 			if (mode->id != 0)
922 				privp->mode = mode;
923 			else
924 				LEAVE(EINVAL);
925 			break;
926 		    }
927 		case NGM_PPPOE_GETMODE:
928 			NG_MKRESPONSE(resp, msg, strlen(privp->mode->name) + 1,
929 			    M_NOWAIT);
930 			if (resp == NULL)
931 				LEAVE(ENOMEM);
932 			strlcpy((char *)resp->data, privp->mode->name,
933 			    strlen(privp->mode->name) + 1);
934 			break;
935 		default:
936 			LEAVE(EINVAL);
937 		}
938 		break;
939 	default:
940 		LEAVE(EINVAL);
941 	}
942 
943 	/* Take care of synchronous response, if any */
944 quit:
945 	NG_RESPOND_MSG(error, node, item, resp);
946 	/* Free the message and return */
947 	NG_FREE_MSG(msg);
948 	return(error);
949 }
950 
951 /*
952  * Start a client into the first state. A separate function because
953  * it can be needed if the negotiation times out.
954  */
955 static void
956 pppoe_start(sessp sp)
957 {
958 	priv_p	privp = NG_NODE_PRIVATE(NG_PPPOE_SESSION_NODE(sp));
959 	struct {
960 		struct pppoe_tag hdr;
961 		union	uniq	data;
962 	} __packed uniqtag;
963 
964 	/*
965 	 * kick the state machine into starting up
966 	 */
967 	DBG;
968 	sp->state = PPPOE_SINIT;
969 	/* Reset the packet header to broadcast. Since we are in a client
970 	 * mode use configured ethertype. */
971 	memcpy((void *)&sp->neg->pkt->pkt_header.eh,
972 	    (const void *)privp->mode->eh_prototype,
973 	    sizeof(struct ether_header));
974 	sp->neg->pkt->pkt_header.ph.code = PADI_CODE;
975 	uniqtag.hdr.tag_type = PTT_HOST_UNIQ;
976 	uniqtag.hdr.tag_len = htons((u_int16_t)sizeof(uniqtag.data));
977 	uniqtag.data.pointer = sp;
978 	init_tags(sp);
979 	insert_tag(sp, &uniqtag.hdr);
980 	insert_tag(sp, &sp->neg->service.hdr);
981 	make_packet(sp);
982 	sendpacket(sp);
983 }
984 
985 static int
986 send_acname(sessp sp, const struct pppoe_tag *tag)
987 {
988 	int error, tlen;
989 	struct ng_mesg *msg;
990 	struct ngpppoe_sts *sts;
991 
992 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_ACNAME,
993 	    sizeof(struct ngpppoe_sts), M_NOWAIT);
994 	if (msg == NULL)
995 		return (ENOMEM);
996 
997 	sts = (struct ngpppoe_sts *)msg->data;
998 	tlen = min(NG_HOOKSIZ - 1, ntohs(tag->tag_len));
999 	strncpy(sts->hook, tag->tag_data, tlen);
1000 	sts->hook[tlen] = '\0';
1001 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, 0);
1002 
1003 	return (error);
1004 }
1005 
1006 static int
1007 send_sessionid(sessp sp)
1008 {
1009 	int error;
1010 	struct ng_mesg *msg;
1011 
1012 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_SESSIONID,
1013 	    sizeof(u_int16_t), M_NOWAIT);
1014 	if (msg == NULL)
1015 		return (ENOMEM);
1016 
1017 	*(u_int16_t *)msg->data = sp->Session_ID;
1018 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, 0);
1019 
1020 	return (error);
1021 }
1022 
1023 /*
1024  * Receive data, and do something with it.
1025  * The caller will never free m, so if we use up this data
1026  * or abort we must free it.
1027  */
1028 static int
1029 ng_pppoe_rcvdata(hook_p hook, item_p item)
1030 {
1031 	node_p			node = NG_HOOK_NODE(hook);
1032 	const priv_p		privp = NG_NODE_PRIVATE(node);
1033 	sessp			sp = NG_HOOK_PRIVATE(hook);
1034 	const struct pppoe_full_hdr *wh;
1035 	const struct pppoe_hdr	*ph;
1036 	int			error = 0;
1037 	u_int16_t		session;
1038 	u_int16_t		length;
1039 	u_int8_t		code;
1040 	const struct pppoe_tag	*utag = NULL, *tag = NULL;
1041 	hook_p 			sendhook;
1042 	struct {
1043 		struct pppoe_tag hdr;
1044 		union	uniq	data;
1045 	} __packed uniqtag;
1046 	negp			neg = NULL;
1047 	struct mbuf		*m;
1048 
1049 	DBG;
1050 	NGI_GET_M(item, m);
1051 	if (NG_HOOK_PRIVATE(hook) == &privp->debug_hook) {
1052 		/*
1053 		 * Data from the debug hook gets sent without modification
1054 		 * straight to the ethernet.
1055 		 */
1056 		NG_FWD_ITEM_HOOK( error, item, privp->ethernet_hook);
1057 	 	privp->packets_out++;
1058 	} else if (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook) {
1059 		/*
1060 		 * Incoming data.
1061 		 * Dig out various fields from the packet.
1062 		 * use them to decide where to send it.
1063 		 */
1064 
1065  		privp->packets_in++;
1066 		if( m->m_len < sizeof(*wh)) {
1067 			m = m_pullup(m, sizeof(*wh)); /* Checks length */
1068 			if (m == NULL) {
1069 				printf("couldn't m_pullup\n");
1070 				LEAVE(ENOBUFS);
1071 			}
1072 		}
1073 		wh = mtod(m, struct pppoe_full_hdr *);
1074 		length = ntohs(wh->ph.length);
1075 		switch(wh->eh.ether_type) {
1076 		case	ETHERTYPE_PPPOE_STUPID_DISC: /* fall through */
1077 		case	ETHERTYPE_PPPOE_DISC:
1078 			/*
1079 			 * We need to try to make sure that the tag area
1080 			 * is contiguous, or we could wander off the end
1081 			 * of a buffer and make a mess.
1082 			 * (Linux wouldn't have this problem).
1083 			 */
1084 			if (m->m_pkthdr.len <= MHLEN) {
1085 				if( m->m_len < m->m_pkthdr.len) {
1086 					m = m_pullup(m, m->m_pkthdr.len);
1087 					if (m == NULL) {
1088 						printf("couldn't m_pullup\n");
1089 						LEAVE(ENOBUFS);
1090 					}
1091 				}
1092 			}
1093 			if (m->m_len != m->m_pkthdr.len) {
1094 				/*
1095 				 * It's not all in one piece.
1096 				 * We need to do extra work.
1097 				 * Put it into a cluster.
1098 				 */
1099 				struct mbuf *n;
1100 				n = m_dup(m, M_DONTWAIT);
1101 				m_freem(m);
1102 				m = n;
1103 				if (m) {
1104 					/* just check we got a cluster */
1105 					if (m->m_len != m->m_pkthdr.len) {
1106 						m_freem(m);
1107 						m = NULL;
1108 					}
1109 				}
1110 				if (m == NULL) {
1111 					printf("packet fragmented\n");
1112 					LEAVE(EMSGSIZE);
1113 				}
1114 			}
1115 			wh = mtod(m, struct pppoe_full_hdr *);
1116 			length = ntohs(wh->ph.length);
1117 			ph = &wh->ph;
1118 			session = ntohs(wh->ph.sid);
1119 			code = wh->ph.code;
1120 
1121 			switch(code) {
1122 			case	PADI_CODE:
1123 				/*
1124 				 * We are a server:
1125 				 * Look for a hook with the required service
1126 				 * and send the ENTIRE packet up there.
1127 				 * It should come back to a new hook in
1128 				 * PRIMED state. Look there for further
1129 				 * processing.
1130 				 */
1131 				tag = get_tag(ph, PTT_SRV_NAME);
1132 				if (tag == NULL) {
1133 					printf("no service tag\n");
1134 					LEAVE(ENETUNREACH);
1135 				}
1136 				sendhook = pppoe_match_svc(NG_HOOK_NODE(hook),
1137 			    		tag->tag_data, ntohs(tag->tag_len),
1138 					NG_MATCH_ANY);
1139 				if (sendhook) {
1140 					NG_FWD_NEW_DATA(error, item,
1141 								sendhook, m);
1142 				} else {
1143 					LEAVE(ENETUNREACH);
1144 				}
1145 				break;
1146 			case	PADO_CODE:
1147 				/*
1148 				 * We are a client:
1149 				 * Use the host_uniq tag to find the
1150 				 * hook this is in response to.
1151 				 * Received #2, now send #3
1152 				 * For now simply accept the first we receive.
1153 				 */
1154 				utag = get_tag(ph, PTT_HOST_UNIQ);
1155 				if ((utag == NULL)
1156 				|| (ntohs(utag->tag_len) != sizeof(sp))) {
1157 					printf("no host unique field\n");
1158 					LEAVE(ENETUNREACH);
1159 				}
1160 
1161 				sendhook = pppoe_finduniq(node, utag);
1162 				if (sendhook == NULL) {
1163 					printf("no matching session\n");
1164 					LEAVE(ENETUNREACH);
1165 				}
1166 
1167 				/*
1168 				 * Check the session is in the right state.
1169 				 * It needs to be in PPPOE_SINIT.
1170 				 */
1171 				sp = NG_HOOK_PRIVATE(sendhook);
1172 				if (sp->state != PPPOE_SINIT) {
1173 					printf("session in wrong state\n");
1174 					LEAVE(ENETUNREACH);
1175 				}
1176 				neg = sp->neg;
1177 				ng_uncallout(&neg->handle, node);
1178 
1179 				/*
1180 				 * This is the first time we hear
1181 				 * from the server, so note it's
1182 				 * unicast address, replacing the
1183 				 * broadcast address .
1184 				 */
1185 				bcopy(wh->eh.ether_shost,
1186 					neg->pkt->pkt_header.eh.ether_dhost,
1187 					ETHER_ADDR_LEN);
1188 				neg->timeout = 0;
1189 				neg->pkt->pkt_header.ph.code = PADR_CODE;
1190 				init_tags(sp);
1191 				insert_tag(sp, utag);      /* Host Unique */
1192 				if ((tag = get_tag(ph, PTT_AC_COOKIE)))
1193 					insert_tag(sp, tag); /* return cookie */
1194 				if ((tag = get_tag(ph, PTT_AC_NAME))) {
1195 					insert_tag(sp, tag); /* return it */
1196 					send_acname(sp, tag);
1197 				}
1198 				insert_tag(sp, &neg->service.hdr); /* Service */
1199 				scan_tags(sp, ph);
1200 				make_packet(sp);
1201 				sp->state = PPPOE_SREQ;
1202 				sendpacket(sp);
1203 				break;
1204 			case	PADR_CODE:
1205 
1206 				/*
1207 				 * We are a server:
1208 				 * Use the ac_cookie tag to find the
1209 				 * hook this is in response to.
1210 				 */
1211 				utag = get_tag(ph, PTT_AC_COOKIE);
1212 				if ((utag == NULL)
1213 				|| (ntohs(utag->tag_len) != sizeof(sp))) {
1214 					LEAVE(ENETUNREACH);
1215 				}
1216 
1217 				sendhook = pppoe_finduniq(node, utag);
1218 				if (sendhook == NULL) {
1219 					LEAVE(ENETUNREACH);
1220 				}
1221 
1222 				/*
1223 				 * Check the session is in the right state.
1224 				 * It needs to be in PPPOE_SOFFER
1225 				 * or PPPOE_NEWCONNECTED. If the latter,
1226 				 * then this is a retry by the client.
1227 				 * so be nice, and resend.
1228 				 */
1229 				sp = NG_HOOK_PRIVATE(sendhook);
1230 				if (sp->state == PPPOE_NEWCONNECTED) {
1231 					/*
1232 					 * Whoa! drop back to resend that
1233 					 * PADS packet.
1234 					 * We should still have a copy of it.
1235 					 */
1236 					sp->state = PPPOE_SOFFER;
1237 				}
1238 				if (sp->state != PPPOE_SOFFER) {
1239 					LEAVE (ENETUNREACH);
1240 					break;
1241 				}
1242 				neg = sp->neg;
1243 				ng_uncallout(&neg->handle, node);
1244 				neg->pkt->pkt_header.ph.code = PADS_CODE;
1245 				if (sp->Session_ID == 0)
1246 					neg->pkt->pkt_header.ph.sid =
1247 					    htons(sp->Session_ID
1248 						= get_new_sid(node));
1249 				send_sessionid(sp);
1250 				neg->timeout = 0;
1251 				/*
1252 				 * start working out the tags to respond with.
1253 				 */
1254 				init_tags(sp);
1255 				insert_tag(sp, &neg->ac_name.hdr); /* AC_NAME */
1256 				if ((tag = get_tag(ph, PTT_SRV_NAME)))
1257 					insert_tag(sp, tag);/* return service */
1258 				if ((tag = get_tag(ph, PTT_HOST_UNIQ)))
1259 					insert_tag(sp, tag); /* return it */
1260 				insert_tag(sp, utag);	/* ac_cookie */
1261 				scan_tags(sp, ph);
1262 				make_packet(sp);
1263 				sp->state = PPPOE_NEWCONNECTED;
1264 				sendpacket(sp);
1265 				/*
1266 				 * Having sent the last Negotiation header,
1267 				 * Set up the stored packet header to
1268 				 * be correct for the actual session.
1269 				 * But keep the negotialtion stuff
1270 				 * around in case we need to resend this last
1271 				 * packet. We'll discard it when we move
1272 				 * from NEWCONNECTED to CONNECTED
1273 				 */
1274 				sp->pkt_hdr = neg->pkt->pkt_header;
1275 				/* Configure ethertype depending on what
1276 				 * ethertype was used at discovery phase */
1277 				if (sp->pkt_hdr.eh.ether_type ==
1278 				    ETHERTYPE_PPPOE_STUPID_DISC)
1279 					sp->pkt_hdr.eh.ether_type
1280 						= ETHERTYPE_PPPOE_STUPID_SESS;
1281 				else
1282 					sp->pkt_hdr.eh.ether_type
1283 						= ETHERTYPE_PPPOE_SESS;
1284 				sp->pkt_hdr.ph.code = 0;
1285 				pppoe_send_event(sp, NGM_PPPOE_SUCCESS);
1286 				break;
1287 			case	PADS_CODE:
1288 				/*
1289 				 * We are a client:
1290 				 * Use the host_uniq tag to find the
1291 				 * hook this is in response to.
1292 				 * take the session ID and store it away.
1293 				 * Also make sure the pre-made header is
1294 				 * correct and set us into Session mode.
1295 				 */
1296 				utag = get_tag(ph, PTT_HOST_UNIQ);
1297 				if ((utag == NULL)
1298 				|| (ntohs(utag->tag_len) != sizeof(sp))) {
1299 					LEAVE (ENETUNREACH);
1300 					break;
1301 				}
1302 				sendhook = pppoe_finduniq(node, utag);
1303 				if (sendhook == NULL) {
1304 					LEAVE(ENETUNREACH);
1305 				}
1306 
1307 				/*
1308 				 * Check the session is in the right state.
1309 				 * It needs to be in PPPOE_SREQ.
1310 				 */
1311 				sp = NG_HOOK_PRIVATE(sendhook);
1312 				if (sp->state != PPPOE_SREQ) {
1313 					LEAVE(ENETUNREACH);
1314 				}
1315 				neg = sp->neg;
1316 				ng_uncallout(&neg->handle, node);
1317 				neg->pkt->pkt_header.ph.sid = wh->ph.sid;
1318 				sp->Session_ID = ntohs(wh->ph.sid);
1319 				send_sessionid(sp);
1320 				neg->timeout = 0;
1321 				sp->state = PPPOE_CONNECTED;
1322 				/*
1323 				 * Now we have gone to Connected mode,
1324 				 * Free all resources needed for
1325 				 * negotiation.
1326 				 * Keep a copy of the header we will be using.
1327 				 */
1328 				sp->pkt_hdr = neg->pkt->pkt_header;
1329 				if (privp->mode->id == PPPOE_NONSTANDARD)
1330 					sp->pkt_hdr.eh.ether_type
1331 						= ETHERTYPE_PPPOE_STUPID_SESS;
1332 				else
1333 					sp->pkt_hdr.eh.ether_type
1334 						= ETHERTYPE_PPPOE_SESS;
1335 				sp->pkt_hdr.ph.code = 0;
1336 				m_freem(neg->m);
1337 				FREE(sp->neg, M_NETGRAPH_PPPOE);
1338 				sp->neg = NULL;
1339 				pppoe_send_event(sp, NGM_PPPOE_SUCCESS);
1340 				break;
1341 			case	PADT_CODE:
1342 				/*
1343 				 * Send a 'close' message to the controlling
1344 				 * process (the one that set us up);
1345 				 * And then tear everything down.
1346 				 *
1347 				 * Find matching peer/session combination.
1348 				 */
1349 				sendhook = pppoe_findsession(node, wh);
1350 				if (sendhook == NULL) {
1351 					LEAVE(ENETUNREACH);
1352 				}
1353 				/* send message to creator */
1354 				/* close hook */
1355 				if (sendhook) {
1356 					ng_rmhook_self(sendhook);
1357 				}
1358 				break;
1359 			default:
1360 				LEAVE(EPFNOSUPPORT);
1361 			}
1362 			break;
1363 		case	ETHERTYPE_PPPOE_STUPID_SESS:
1364 		case	ETHERTYPE_PPPOE_SESS:
1365 			/*
1366 			 * find matching peer/session combination.
1367 			 */
1368 			sendhook = pppoe_findsession(node, wh);
1369 			if (sendhook == NULL) {
1370 				LEAVE (ENETUNREACH);
1371 				break;
1372 			}
1373 			sp = NG_HOOK_PRIVATE(sendhook);
1374 			m_adj(m, sizeof(*wh));
1375 			if (m->m_pkthdr.len < length) {
1376 				/* Packet too short, dump it */
1377 				LEAVE(EMSGSIZE);
1378 			}
1379 
1380 			/* Also need to trim excess at the end */
1381 			if (m->m_pkthdr.len > length) {
1382 				m_adj(m, -((int)(m->m_pkthdr.len - length)));
1383 			}
1384 			if ( sp->state != PPPOE_CONNECTED) {
1385 				if (sp->state == PPPOE_NEWCONNECTED) {
1386 					sp->state = PPPOE_CONNECTED;
1387 					/*
1388 					 * Now we have gone to Connected mode,
1389 					 * Free all resources needed for
1390 					 * negotiation. Be paranoid about
1391 					 * whether there may be a timeout.
1392 					 */
1393 					m_freem(sp->neg->m);
1394 					ng_uncallout(&sp->neg->handle, node);
1395 					FREE(sp->neg, M_NETGRAPH_PPPOE);
1396 					sp->neg = NULL;
1397 				} else {
1398 					LEAVE (ENETUNREACH);
1399 					break;
1400 				}
1401 			}
1402 			NG_FWD_NEW_DATA( error, item, sendhook, m);
1403 			break;
1404 		default:
1405 			LEAVE(EPFNOSUPPORT);
1406 		}
1407 	} else {
1408 		/*
1409 		 * 	Not ethernet or debug hook..
1410 		 *
1411 		 * The packet has come in on a normal hook.
1412 		 * We need to find out what kind of hook,
1413 		 * So we can decide how to handle it.
1414 		 * Check the hook's state.
1415 		 */
1416 		sp = NG_HOOK_PRIVATE(hook);
1417 		switch (sp->state) {
1418 		case	PPPOE_NEWCONNECTED:
1419 		case	PPPOE_CONNECTED: {
1420 			static const u_char addrctrl[] = { 0xff, 0x03 };
1421 			struct pppoe_full_hdr *wh;
1422 
1423 			/*
1424 			 * Remove PPP address and control fields, if any.
1425 			 * For example, ng_ppp(4) always sends LCP packets
1426 			 * with address and control fields as required by
1427 			 * generic PPP. PPPoE is an exception to the rule.
1428 			 */
1429 			if (m->m_pkthdr.len >= 2) {
1430 				if (m->m_len < 2 && !(m = m_pullup(m, 2)))
1431 					LEAVE(ENOBUFS);
1432 				if (bcmp(mtod(m, u_char *), addrctrl, 2) == 0)
1433 					m_adj(m, 2);
1434 			}
1435 			/*
1436 			 * Bang in a pre-made header, and set the length up
1437 			 * to be correct. Then send it to the ethernet driver.
1438 			 * But first correct the length.
1439 			 */
1440 			sp->pkt_hdr.ph.length = htons((short)(m->m_pkthdr.len));
1441 			M_PREPEND(m, sizeof(*wh), M_DONTWAIT);
1442 			if (m == NULL) {
1443 				LEAVE(ENOBUFS);
1444 			}
1445 			wh = mtod(m, struct pppoe_full_hdr *);
1446 			bcopy(&sp->pkt_hdr, wh, sizeof(*wh));
1447 			NG_FWD_NEW_DATA( error, item, privp->ethernet_hook, m);
1448 			privp->packets_out++;
1449 			break;
1450 			}
1451 		case	PPPOE_PRIMED:
1452 			/*
1453 			 * A PADI packet is being returned by the application
1454 			 * that has set up this hook. This indicates that it
1455 			 * wants us to offer service.
1456 			 */
1457 			neg = sp->neg;
1458 			if (m->m_len < sizeof(*wh)) {
1459 				m = m_pullup(m, sizeof(*wh));
1460 				if (m == NULL) {
1461 					LEAVE(ENOBUFS);
1462 				}
1463 			}
1464 			wh = mtod(m, struct pppoe_full_hdr *);
1465 			ph = &wh->ph;
1466 			session = ntohs(wh->ph.sid);
1467 			length = ntohs(wh->ph.length);
1468 			code = wh->ph.code;
1469 			/* Use peers mode in session */
1470 			neg->pkt->pkt_header.eh.ether_type = wh->eh.ether_type;
1471 			if ( code != PADI_CODE) {
1472 				LEAVE(EINVAL);
1473 			};
1474 			ng_uncallout(&neg->handle, node);
1475 
1476 			/*
1477 			 * This is the first time we hear
1478 			 * from the client, so note it's
1479 			 * unicast address, replacing the
1480 			 * broadcast address.
1481 			 */
1482 			bcopy(wh->eh.ether_shost,
1483 				neg->pkt->pkt_header.eh.ether_dhost,
1484 				ETHER_ADDR_LEN);
1485 			sp->state = PPPOE_SOFFER;
1486 			neg->timeout = 0;
1487 			neg->pkt->pkt_header.ph.code = PADO_CODE;
1488 
1489 			/*
1490 			 * start working out the tags to respond with.
1491 			 */
1492 			uniqtag.hdr.tag_type = PTT_AC_COOKIE;
1493 			uniqtag.hdr.tag_len = htons((u_int16_t)sizeof(sp));
1494 			uniqtag.data.pointer = sp;
1495 			init_tags(sp);
1496 			insert_tag(sp, &neg->ac_name.hdr); /* AC_NAME */
1497 			if ((tag = get_tag(ph, PTT_SRV_NAME)))
1498 				insert_tag(sp, tag);	  /* return service */
1499 			/*
1500 			 * If we have a NULL service request
1501 			 * and have an extra service defined in this hook,
1502 			 * then also add a tag for the extra service.
1503 			 * XXX this is a hack. eventually we should be able
1504 			 * to support advertising many services, not just one
1505 			 */
1506 			if (((tag == NULL) || (tag->tag_len == 0))
1507 			&& (neg->service.hdr.tag_len != 0)) {
1508 				insert_tag(sp, &neg->service.hdr); /* SERVICE */
1509 			}
1510 			if ((tag = get_tag(ph, PTT_HOST_UNIQ)))
1511 				insert_tag(sp, tag); /* returned hostunique */
1512 			insert_tag(sp, &uniqtag.hdr);
1513 			scan_tags(sp, ph);
1514 			make_packet(sp);
1515 			sendpacket(sp);
1516 			break;
1517 
1518 		/*
1519 		 * Packets coming from the hook make no sense
1520 		 * to sessions in these states. Throw them away.
1521 		 */
1522 		case	PPPOE_SINIT:
1523 		case	PPPOE_SREQ:
1524 		case	PPPOE_SOFFER:
1525 		case	PPPOE_SNONE:
1526 		case	PPPOE_LISTENING:
1527 		case	PPPOE_DEAD:
1528 		default:
1529 			LEAVE(ENETUNREACH);
1530 		}
1531 	}
1532 quit:
1533 	if (item)
1534 		NG_FREE_ITEM(item);
1535 	NG_FREE_M(m);
1536 	return error;
1537 }
1538 
1539 /*
1540  * Do local shutdown processing..
1541  * If we are a persistant device, we might refuse to go away, and
1542  * we'd only remove our links and reset ourself.
1543  */
1544 static int
1545 ng_pppoe_shutdown(node_p node)
1546 {
1547 	const priv_p privdata = NG_NODE_PRIVATE(node);
1548 
1549 	DBG;
1550 	NG_NODE_SET_PRIVATE(node, NULL);
1551 	NG_NODE_UNREF(privdata->node);
1552 	FREE(privdata, M_NETGRAPH_PPPOE);
1553 	return (0);
1554 }
1555 
1556 /*
1557  * This is called once we've already connected a new hook to the other node.
1558  * It gives us a chance to balk at the last minute.
1559  */
1560 static int
1561 ng_pppoe_connect(hook_p hook)
1562 {
1563 	/* be really amiable and just say "YUP that's OK by me! " */
1564 	return (0);
1565 }
1566 
1567 /*
1568  * Hook disconnection
1569  *
1570  * Clean up all dangling links and information about the session/hook.
1571  * For this type, removal of the last link destroys the node
1572  */
1573 static int
1574 ng_pppoe_disconnect(hook_p hook)
1575 {
1576 	node_p node = NG_HOOK_NODE(hook);
1577 	priv_p privp = NG_NODE_PRIVATE(node);
1578 	sessp	sp;
1579 	int 	hooks;
1580 
1581 	DBG;
1582 	hooks = NG_NODE_NUMHOOKS(node); /* this one already not counted */
1583 	if (NG_HOOK_PRIVATE(hook) == &privp->debug_hook) {
1584 		privp->debug_hook = NULL;
1585 	} else if (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook) {
1586 		privp->ethernet_hook = NULL;
1587 		if (NG_NODE_IS_VALID(node))
1588 			ng_rmnode_self(node);
1589 	} else {
1590 		sp = NG_HOOK_PRIVATE(hook);
1591 		if (sp->state != PPPOE_SNONE ) {
1592 			pppoe_send_event(sp, NGM_PPPOE_CLOSE);
1593 		}
1594 		/*
1595 		 * According to the spec, if we are connected,
1596 		 * we should send a DISC packet if we are shutting down
1597 		 * a session.
1598 		 */
1599 		if ((privp->ethernet_hook)
1600 		&& ((sp->state == PPPOE_CONNECTED)
1601 		 || (sp->state == PPPOE_NEWCONNECTED))) {
1602 			struct mbuf *m;
1603 			struct pppoe_full_hdr *wh;
1604 			struct pppoe_tag *tag;
1605 			int	msglen = strlen(SIGNOFF);
1606 			int error = 0;
1607 
1608 			/* revert the stored header to DISC/PADT mode */
1609 		 	wh = &sp->pkt_hdr;
1610 			wh->ph.code = PADT_CODE;
1611 			/* Configure ethertype depending on what was used during
1612 			 * sessions stage. */
1613 			if (sp->pkt_hdr.eh.ether_type ==
1614 			    ETHERTYPE_PPPOE_STUPID_SESS)
1615 				wh->eh.ether_type = ETHERTYPE_PPPOE_STUPID_DISC;
1616 			else
1617 				wh->eh.ether_type = ETHERTYPE_PPPOE_DISC;
1618 
1619 			/* generate a packet of that type */
1620 			MGETHDR(m, M_DONTWAIT, MT_DATA);
1621 			if(m == NULL)
1622 				printf("pppoe: Session out of mbufs\n");
1623 			else {
1624 				m->m_pkthdr.rcvif = NULL;
1625 				m->m_pkthdr.len = m->m_len = sizeof(*wh);
1626 				bcopy((caddr_t)wh, mtod(m, caddr_t),
1627 				    sizeof(*wh));
1628 				/*
1629 				 * Add a General error message and adjust
1630 				 * sizes
1631 				 */
1632 				wh = mtod(m, struct pppoe_full_hdr *);
1633 				tag = wh->ph.tag;
1634 				tag->tag_type = PTT_GEN_ERR;
1635 				tag->tag_len = htons((u_int16_t)msglen);
1636 				strncpy(tag->tag_data, SIGNOFF, msglen);
1637 				m->m_pkthdr.len = (m->m_len += sizeof(*tag) +
1638 				    msglen);
1639 				wh->ph.length = htons(sizeof(*tag) + msglen);
1640 				NG_SEND_DATA_ONLY(error,
1641 					privp->ethernet_hook, m);
1642 			}
1643 		}
1644 		/*
1645 		 * As long as we have somewhere to store the timeout handle,
1646 		 * we may have a timeout pending.. get rid of it.
1647 		 */
1648 		if (sp->neg) {
1649 			ng_uncallout(&sp->neg->handle, node);
1650 			if (sp->neg->m)
1651 				m_freem(sp->neg->m);
1652 			FREE(sp->neg, M_NETGRAPH_PPPOE);
1653 		}
1654 		FREE(sp, M_NETGRAPH_PPPOE);
1655 		NG_HOOK_SET_PRIVATE(hook, NULL);
1656 		/* work out how many session hooks there are */
1657 		/* Node goes away on last session hook removal */
1658 		if (privp->ethernet_hook) hooks -= 1;
1659 		if (privp->debug_hook) hooks -= 1;
1660 	}
1661 	if ((NG_NODE_NUMHOOKS(node) == 0)
1662 	&& (NG_NODE_IS_VALID(node)))
1663 		ng_rmnode_self(node);
1664 	return (0);
1665 }
1666 
1667 /*
1668  * timeouts come here.
1669  */
1670 static void
1671 pppoe_ticker(node_p node, hook_p hook, void *arg1, int arg2)
1672 {
1673 	sessp	sp = NG_HOOK_PRIVATE(hook);
1674 	negp	neg = sp->neg;
1675 	int	error = 0;
1676 	struct mbuf *m0 = NULL;
1677 	priv_p privp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
1678 
1679 	DBG;
1680 	switch(sp->state) {
1681 		/*
1682 		 * resend the last packet, using an exponential backoff.
1683 		 * After a period of time, stop growing the backoff,
1684 		 * and either leave it, or revert to the start.
1685 		 */
1686 	case	PPPOE_SINIT:
1687 	case	PPPOE_SREQ:
1688 		/* timeouts on these produce resends */
1689 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1690 		NG_SEND_DATA_ONLY( error, privp->ethernet_hook, m0);
1691 		ng_callout(&neg->handle, node, hook, neg->timeout * hz,
1692 		    pppoe_ticker, NULL, 0);
1693 		if ((neg->timeout <<= 1) > PPPOE_TIMEOUT_LIMIT) {
1694 			if (sp->state == PPPOE_SREQ) {
1695 				/* revert to SINIT mode */
1696 				pppoe_start(sp);
1697 			} else {
1698 				neg->timeout = PPPOE_TIMEOUT_LIMIT;
1699 			}
1700 		}
1701 		break;
1702 	case	PPPOE_PRIMED:
1703 	case	PPPOE_SOFFER:
1704 		/* a timeout on these says "give up" */
1705 		ng_rmhook_self(hook);
1706 		break;
1707 	default:
1708 		/* timeouts have no meaning in other states */
1709 		printf("pppoe: unexpected timeout\n");
1710 	}
1711 }
1712 
1713 
1714 static void
1715 sendpacket(sessp sp)
1716 {
1717 	struct	mbuf *m0 = NULL;
1718 	hook_p	hook = sp->hook;
1719 	node_p	node = NG_HOOK_NODE(hook);
1720 	priv_p	privp = NG_NODE_PRIVATE(node);
1721 	negp	neg = sp->neg;
1722 	int	error = 0;
1723 
1724 	DBG;
1725 	switch(sp->state) {
1726 	case	PPPOE_LISTENING:
1727 	case	PPPOE_DEAD:
1728 	case	PPPOE_SNONE:
1729 	case	PPPOE_CONNECTED:
1730 		printf("pppoe: sendpacket: unexpected state\n");
1731 		break;
1732 
1733 	case	PPPOE_NEWCONNECTED:
1734 		/* send the PADS without a timeout - we're now connected */
1735 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1736 		NG_SEND_DATA_ONLY( error, privp->ethernet_hook, m0);
1737 		break;
1738 
1739 	case	PPPOE_PRIMED:
1740 		/* No packet to send, but set up the timeout */
1741 		ng_callout(&neg->handle, node, hook, PPPOE_OFFER_TIMEOUT * hz,
1742 		    pppoe_ticker, NULL, 0);
1743 		break;
1744 
1745 	case	PPPOE_SOFFER:
1746 		/*
1747 		 * send the offer but if they don't respond
1748 		 * in PPPOE_OFFER_TIMEOUT seconds, forget about it.
1749 		 */
1750 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1751 		NG_SEND_DATA_ONLY( error, privp->ethernet_hook, m0);
1752 		ng_callout(&neg->handle, node, hook, PPPOE_OFFER_TIMEOUT * hz,
1753 		    pppoe_ticker, NULL, 0);
1754 		break;
1755 
1756 	case	PPPOE_SINIT:
1757 	case	PPPOE_SREQ:
1758 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1759 		NG_SEND_DATA_ONLY( error, privp->ethernet_hook, m0);
1760 		ng_callout(&neg->handle, node, hook, PPPOE_INITIAL_TIMEOUT * hz,
1761 		    pppoe_ticker, NULL, 0);
1762 		neg->timeout = PPPOE_INITIAL_TIMEOUT * 2;
1763 		break;
1764 
1765 	default:
1766 		error = EINVAL;
1767 		printf("pppoe: timeout: bad state\n");
1768 	}
1769 	/* return (error); */
1770 }
1771 
1772 /*
1773  * Parse an incoming packet to see if any tags should be copied to the
1774  * output packet. Don't do any tags that have been handled in the main
1775  * state machine.
1776  */
1777 static const struct pppoe_tag*
1778 scan_tags(sessp	sp, const struct pppoe_hdr* ph)
1779 {
1780 	const char *const end = (const char *)next_tag(ph);
1781 	const char *ptn;
1782 	const struct pppoe_tag *pt = &ph->tag[0];
1783 	/*
1784 	 * Keep processing tags while a tag header will still fit.
1785 	 */
1786 	DBG;
1787 	while((const char*)(pt + 1) <= end) {
1788 		/*
1789 		 * If the tag data would go past the end of the packet, abort.
1790 		 */
1791 		ptn = (((const char *)(pt + 1)) + ntohs(pt->tag_len));
1792 		if(ptn > end)
1793 			return NULL;
1794 
1795 		switch (pt->tag_type) {
1796 		case	PTT_RELAY_SID:
1797 			insert_tag(sp, pt);
1798 			break;
1799 		case	PTT_EOL:
1800 			return NULL;
1801 		case	PTT_SRV_NAME:
1802 		case	PTT_AC_NAME:
1803 		case	PTT_HOST_UNIQ:
1804 		case	PTT_AC_COOKIE:
1805 		case	PTT_VENDOR:
1806 		case	PTT_SRV_ERR:
1807 		case	PTT_SYS_ERR:
1808 		case	PTT_GEN_ERR:
1809 			break;
1810 		}
1811 		pt = (const struct pppoe_tag*)ptn;
1812 	}
1813 	return NULL;
1814 }
1815 
1816 static	int
1817 pppoe_send_event(sessp sp, enum cmd cmdid)
1818 {
1819 	int error;
1820 	struct ng_mesg *msg;
1821 	struct ngpppoe_sts *sts;
1822 
1823 	DBG;
1824 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, cmdid,
1825 			sizeof(struct ngpppoe_sts), M_NOWAIT);
1826 	if (msg == NULL)
1827 		return (ENOMEM);
1828 	sts = (struct ngpppoe_sts *)msg->data;
1829 	strncpy(sts->hook, NG_HOOK_NAME(sp->hook), NG_HOOKSIZ);
1830 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, 0);
1831 	return (error);
1832 }
1833