xref: /freebsd/sys/netgraph/ng_pppoe.c (revision 6af83ee0d2941d18880b6aaa2b4facd1d30c6106)
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 
185 /*
186  * States for the session state machine.
187  * These have no meaning if there is no hook attached yet.
188  */
189 enum state {
190     PPPOE_SNONE=0,	/* [both] Initial state */
191     PPPOE_LISTENING,	/* [Daemon] Listening for discover initiation pkt */
192     PPPOE_SINIT,	/* [Client] Sent discovery initiation */
193     PPPOE_PRIMED,	/* [Server] Awaiting PADI from daemon */
194     PPPOE_SOFFER,	/* [Server] Sent offer message  (got PADI)*/
195     PPPOE_SREQ,		/* [Client] Sent a Request */
196     PPPOE_NEWCONNECTED,	/* [Server] Connection established, No data received */
197     PPPOE_CONNECTED,	/* [Both] Connection established, Data received */
198     PPPOE_DEAD		/* [Both] */
199 };
200 
201 #define NUMTAGS 20 /* number of tags we are set up to work with */
202 
203 /*
204  * Information we store for each hook on each node for negotiating the
205  * session. The mbuf and cluster are freed once negotiation has completed.
206  * The whole negotiation block is then discarded.
207  */
208 
209 struct sess_neg {
210 	struct mbuf 		*m; /* holds cluster with last sent packet */
211 	union	packet		*pkt; /* points within the above cluster */
212 	struct callout		handle;   /* see timeout(9) */
213 	u_int			timeout; /* 0,1,2,4,8,16 etc. seconds */
214 	u_int			numtags;
215 	const struct pppoe_tag	*tags[NUMTAGS];
216 	u_int			service_len;
217 	u_int			ac_name_len;
218 
219 	struct datatag		service;
220 	struct datatag		ac_name;
221 };
222 typedef struct sess_neg *negp;
223 
224 /*
225  * Session information that is needed after connection.
226  */
227 struct sess_con {
228 	hook_p  		hook;
229 	u_int16_t		Session_ID;
230 	enum state		state;
231 	ng_ID_t			creator;		/* who to notify */
232 	struct pppoe_full_hdr	pkt_hdr;	/* used when connected */
233 	negp			neg;		/* used when negotiating */
234 	/*struct sess_con	*hash_next;*/	/* not yet used */
235 };
236 typedef struct sess_con *sessp;
237 
238 #define	NG_PPPOE_SESSION_NODE(sp) NG_HOOK_NODE(sp->hook)
239 
240 enum {
241 	PPPOE_STANDARD	= 1,	/* standard RFC2516 mode */
242 	PPPOE_NONSTANDARD,	/* 3Com proprietary mode */
243 };
244 
245 struct ng_pppoe_mode_t {
246 	u_int8_t        		id;
247 	const struct ether_header	*eh_prototype;
248 	const char      		*name;
249 };
250 
251 static const struct ether_header eh_standard =
252 	{{0xff,0xff,0xff,0xff,0xff,0xff},
253 	{0x00,0x00,0x00,0x00,0x00,0x00},
254 	ETHERTYPE_PPPOE_DISC};
255 
256 static const struct ether_header eh_3Com =
257 	{{0xff,0xff,0xff,0xff,0xff,0xff},
258 	{0x00,0x00,0x00,0x00,0x00,0x00},
259 	ETHERTYPE_PPPOE_STUPID_DISC};
260 
261 static const struct ng_pppoe_mode_t ng_pppoe_modes[] = {
262 	{ PPPOE_STANDARD,	&eh_standard,	NG_PPPOE_STANDARD },
263 	{ PPPOE_NONSTANDARD,	&eh_3Com,	NG_PPPOE_NONSTANDARD },
264 	{ 0, NULL},
265 };
266 
267 /*
268  * Information we store for each node
269  */
270 struct PPPOE {
271 	node_p		node;		/* back pointer to node */
272 	hook_p  	ethernet_hook;
273 	hook_p  	debug_hook;
274 	u_int   	packets_in;	/* packets in from ethernet */
275 	u_int   	packets_out;	/* packets out towards ethernet */
276 	u_int32_t	flags;
277 	const struct ng_pppoe_mode_t	*mode;	/* standard PPPoE or 3Com? */
278 	/*struct sess_con *buckets[HASH_SIZE];*/	/* not yet used */
279 };
280 typedef struct PPPOE *priv_p;
281 
282 /* Deprecated sysctl, leaved here to keep compatibility for some time */
283 #define PPPOE_SYSCTL_KEEPSTANDARD	-1
284 #define PPPOE_SYSCTL_STANDARD		0
285 #define PPPOE_SYSCTL_NONSTANDARD	1
286 static int pppoe_mode = PPPOE_SYSCTL_KEEPSTANDARD;
287 static const struct ng_pppoe_mode_t *sysctl_mode = ng_pppoe_modes;
288 
289 static int
290 ngpppoe_set_ethertype(SYSCTL_HANDLER_ARGS)
291 {
292 	int error;
293 	int val;
294 
295 	val = pppoe_mode;
296 	error = sysctl_handle_int(oidp, &val, sizeof(int), req);
297 	if (error != 0 || req->newptr == NULL)
298 		return (error);
299 	switch (val) {
300 	case PPPOE_SYSCTL_NONSTANDARD:
301 		sysctl_mode = ng_pppoe_modes + 1;
302 		break;
303 	case PPPOE_SYSCTL_STANDARD:
304 	case PPPOE_SYSCTL_KEEPSTANDARD:
305 		sysctl_mode = ng_pppoe_modes;
306 		break;
307 	default:
308 		return (EINVAL);
309 	}
310 
311 	pppoe_mode = val;
312 	printf("net.graph.nonstandard_pppoe is deprecated. See ng_pppoe(4), ppp(8).\n");
313 	return (0);
314 }
315 
316 SYSCTL_PROC(_net_graph, OID_AUTO, nonstandard_pppoe, CTLTYPE_INT | CTLFLAG_RW,
317     0, sizeof(int), ngpppoe_set_ethertype, "I", "select normal or stupid ISP");
318 
319 union uniq {
320 	char bytes[sizeof(void *)];
321 	void * pointer;
322 	};
323 
324 #define	LEAVE(x) do { error = x; goto quit; } while(0)
325 static void	pppoe_start(sessp sp);
326 static void	sendpacket(sessp sp);
327 static void	pppoe_ticker(node_p node, hook_p hook, void *arg1, int arg2);
328 static const	struct pppoe_tag *scan_tags(sessp sp,
329 			const struct pppoe_hdr* ph);
330 static	int	pppoe_send_event(sessp sp, enum cmd cmdid);
331 
332 /*************************************************************************
333  * Some basic utilities  from the Linux version with author's permission.*
334  * Author:	Michal Ostrowski <mostrows@styx.uwaterloo.ca>		 *
335  ************************************************************************/
336 
337 /*
338  * Generate a new session id
339  * XXX find out the FreeBSD locking scheme.
340  */
341 static u_int16_t
342 get_new_sid(node_p node)
343 {
344 	static int pppoe_sid = 10;
345 	sessp sp;
346 	hook_p	hook;
347 	u_int16_t val;
348 	priv_p privp = NG_NODE_PRIVATE(node);
349 
350 	DBG;
351 restart:
352 	val = pppoe_sid++;
353 	/*
354 	 * Spec says 0xFFFF is reserved.
355 	 * Also don't use 0x0000
356 	 */
357 	if (val == 0xffff) {
358 		pppoe_sid = 20;
359 		goto restart;
360 	}
361 
362 	/* Check it isn't already in use */
363 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
364 		/* don't check special hooks */
365 		if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook)
366 		||  (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook))
367 			continue;
368 		sp = NG_HOOK_PRIVATE(hook);
369 		if (sp->Session_ID == val)
370 			goto restart;
371 	}
372 
373 	return val;
374 }
375 
376 
377 /*
378  * Return the location where the next tag can be put
379  */
380 static __inline const struct pppoe_tag*
381 next_tag(const struct pppoe_hdr* ph)
382 {
383 	return (const struct pppoe_tag*)(((const char*)&ph->tag[0])
384 	    + ntohs(ph->length));
385 }
386 
387 /*
388  * Look for a tag of a specific type
389  * Don't trust any length the other end says.
390  * but assume we already sanity checked ph->length.
391  */
392 static const struct pppoe_tag*
393 get_tag(const struct pppoe_hdr* ph, u_int16_t idx)
394 {
395 	const char *const end = (const char *)next_tag(ph);
396 	const char *ptn;
397 	const struct pppoe_tag *pt = &ph->tag[0];
398 	/*
399 	 * Keep processing tags while a tag header will still fit.
400 	 */
401 	DBG;
402 	while((const char*)(pt + 1) <= end) {
403 	    /*
404 	     * If the tag data would go past the end of the packet, abort.
405 	     */
406 	    ptn = (((const char *)(pt + 1)) + ntohs(pt->tag_len));
407 	    if(ptn > end)
408 		return NULL;
409 
410 	    if(pt->tag_type == idx)
411 		return pt;
412 
413 	    pt = (const struct pppoe_tag*)ptn;
414 	}
415 	return NULL;
416 }
417 
418 /**************************************************************************
419  * inlines to initialise or add tags to a session's tag list,
420  **************************************************************************/
421 /*
422  * Initialise the session's tag list
423  */
424 static void
425 init_tags(sessp sp)
426 {
427 	DBG;
428 	if(sp->neg == NULL) {
429 		printf("pppoe: asked to init NULL neg pointer\n");
430 		return;
431 	}
432 	sp->neg->numtags = 0;
433 }
434 
435 static void
436 insert_tag(sessp sp, const struct pppoe_tag *tp)
437 {
438 	int	i;
439 	negp neg;
440 
441 	DBG;
442 	if((neg = sp->neg) == NULL) {
443 		printf("pppoe: asked to use NULL neg pointer\n");
444 		return;
445 	}
446 	if ((i = neg->numtags++) < NUMTAGS) {
447 		neg->tags[i] = tp;
448 	} else {
449 		printf("pppoe: asked to add too many tags to packet\n");
450 		neg->numtags--;
451 	}
452 }
453 
454 /*
455  * Make up a packet, using the tags filled out for the session.
456  *
457  * Assume that the actual pppoe header and ethernet header
458  * are filled out externally to this routine.
459  * Also assume that neg->wh points to the correct
460  * location at the front of the buffer space.
461  */
462 static void
463 make_packet(sessp sp) {
464 	struct pppoe_full_hdr *wh = &sp->neg->pkt->pkt_header;
465 	const struct pppoe_tag **tag;
466 	char *dp;
467 	int count;
468 	int tlen;
469 	u_int16_t length = 0;
470 
471 	DBG;
472 	if ((sp->neg == NULL) || (sp->neg->m == NULL)) {
473 		printf("pppoe: make_packet called from wrong state\n");
474 	}
475 	dp = (char *)wh->ph.tag;
476 	for (count = 0, tag = sp->neg->tags;
477 	    ((count < sp->neg->numtags) && (count < NUMTAGS));
478 	    tag++, count++) {
479 		tlen = ntohs((*tag)->tag_len) + sizeof(**tag);
480 		if ((length + tlen) > (ETHER_MAX_LEN - 4 - sizeof(*wh))) {
481 			printf("pppoe: tags too long\n");
482 			sp->neg->numtags = count;
483 			break;	/* XXX chop off what's too long */
484 		}
485 		bcopy(*tag, (char *)dp, tlen);
486 		length += tlen;
487 		dp += tlen;
488 	}
489  	wh->ph.length = htons(length);
490 	sp->neg->m->m_len = length + sizeof(*wh);
491 	sp->neg->m->m_pkthdr.len = length + sizeof(*wh);
492 }
493 
494 /**************************************************************************
495  * Routine to match a service offered					  *
496  **************************************************************************/
497 /*
498  * Find a hook that has a service string that matches that
499  * we are seeking. for now use a simple string.
500  * In the future we may need something like regexp().
501  * for testing allow a null string to match 1st found and a null service
502  * to match all requests. Also make '*' do the same.
503  */
504 
505 #define NG_MATCH_EXACT	1
506 #define NG_MATCH_ANY	2
507 
508 static hook_p
509 pppoe_match_svc(node_p node, const char *svc_name, int svc_len, int match)
510 {
511 	sessp	sp	= NULL;
512 	negp	neg	= NULL;
513 	priv_p	privp	= NG_NODE_PRIVATE(node);
514 	hook_p	allhook	= NULL;
515 	hook_p	hook;
516 
517 	DBG;
518 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
519 
520 		/* skip any hook that is debug or ethernet */
521 		if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook)
522 		||  (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook))
523 			continue;
524 		sp = NG_HOOK_PRIVATE(hook);
525 
526 		/* Skip any sessions which are not in LISTEN mode. */
527 		if ( sp->state != PPPOE_LISTENING)
528 			continue;
529 
530 		neg = sp->neg;
531 
532 		/* Special case for a blank or "*" service name (wildcard) */
533 		if (match == NG_MATCH_ANY && neg->service_len == 1 &&
534 		    neg->service.data[0] == '*') {
535 			allhook = hook;
536 			continue;
537 		}
538 
539 		/* If the lengths don't match, that aint it. */
540 		if (neg->service_len != svc_len)
541 			continue;
542 
543 		/* An exact match? */
544 		if (svc_len == 0)
545 			break;
546 
547 		if (strncmp(svc_name, neg->service.data, svc_len) == 0)
548 			break;
549 	}
550 	return (hook ? hook : allhook);
551 }
552 /**************************************************************************
553  * Routine to find a particular session that matches an incoming packet	  *
554  **************************************************************************/
555 static hook_p
556 pppoe_findsession(node_p node, const struct pppoe_full_hdr *wh)
557 {
558 	sessp	sp = NULL;
559 	hook_p hook = NULL;
560 	priv_p	privp = NG_NODE_PRIVATE(node);
561 	u_int16_t	session = ntohs(wh->ph.sid);
562 
563 	/*
564 	 * find matching peer/session combination.
565 	 */
566 	DBG;
567 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
568 		/* don't check special hooks */
569 		if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook)
570 		||  (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook)) {
571 			continue;
572 		}
573 		sp = NG_HOOK_PRIVATE(hook);
574 		if ( ( (sp->state == PPPOE_CONNECTED)
575 		    || (sp->state == PPPOE_NEWCONNECTED) )
576 		&& (sp->Session_ID == session)
577 		&& (bcmp(sp->pkt_hdr.eh.ether_dhost,
578 		    wh->eh.ether_shost,
579 		    ETHER_ADDR_LEN)) == 0) {
580 			break;
581 		}
582 	}
583 	return (hook);
584 }
585 
586 static hook_p
587 pppoe_finduniq(node_p node, const struct pppoe_tag *tag)
588 {
589 	hook_p hook = NULL;
590 	priv_p	privp = NG_NODE_PRIVATE(node);
591 	union uniq		uniq;
592 
593 	DBG;
594 	bcopy(tag->tag_data, uniq.bytes, sizeof(void *));
595 	/* cycle through all known hooks */
596 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
597 		/* don't check special hooks */
598 		if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook)
599 		||  (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook))
600 			continue;
601 		if (uniq.pointer == NG_HOOK_PRIVATE(hook))
602 			break;
603 	}
604 	return (hook);
605 }
606 
607 /**************************************************************************
608  * start of Netgraph entrypoints					  *
609  **************************************************************************/
610 
611 /*
612  * Allocate the private data structure and the generic node
613  * and link them together.
614  *
615  * ng_make_node_common() returns with a generic node struct
616  * with a single reference for us.. we transfer it to the
617  * private structure.. when we free the private struct we must
618  * unref the node so it gets freed too.
619  */
620 static int
621 ng_pppoe_constructor(node_p node)
622 {
623 	priv_p privdata;
624 
625 	DBG;
626 	/* Initialize private descriptor */
627 	MALLOC(privdata, priv_p, sizeof(*privdata), M_NETGRAPH_PPPOE,
628 	    M_NOWAIT | M_ZERO);
629 	if (privdata == NULL)
630 		return (ENOMEM);
631 
632 	/* Link structs together; this counts as our one reference to *nodep */
633 	NG_NODE_SET_PRIVATE(node, privdata);
634 	privdata->node = node;
635 
636 	/* Initialize to standard mode (the first one in ng_pppoe_modes[]). */
637 	privdata->mode = sysctl_mode;
638 
639 	return (0);
640 }
641 
642 /*
643  * Give our ok for a hook to be added...
644  * point the hook's private info to the hook structure.
645  *
646  * The following hook names are special:
647  *  Ethernet:  the hook that should be connected to a NIC.
648  *  debug:	copies of data sent out here  (when I write the code).
649  * All other hook names need only be unique. (the framework checks this).
650  */
651 static int
652 ng_pppoe_newhook(node_p node, hook_p hook, const char *name)
653 {
654 	const priv_p privp = NG_NODE_PRIVATE(node);
655 	sessp sp;
656 
657 	DBG;
658 	if (strcmp(name, NG_PPPOE_HOOK_ETHERNET) == 0) {
659 		privp->ethernet_hook = hook;
660 		NG_HOOK_SET_PRIVATE(hook, &privp->ethernet_hook);
661 	} else if (strcmp(name, NG_PPPOE_HOOK_DEBUG) == 0) {
662 		privp->debug_hook = hook;
663 		NG_HOOK_SET_PRIVATE(hook, &privp->debug_hook);
664 	} else {
665 		/*
666 		 * Any other unique name is OK.
667 		 * The infrastructure has already checked that it's unique,
668 		 * so just allocate it and hook it in.
669 		 */
670 		MALLOC(sp, sessp, sizeof(*sp), M_NETGRAPH_PPPOE, M_NOWAIT | M_ZERO);
671 		if (sp == NULL) {
672 				return (ENOMEM);
673 		}
674 
675 		NG_HOOK_SET_PRIVATE(hook, sp);
676 		sp->hook = hook;
677 	}
678 	return(0);
679 }
680 
681 /*
682  * Get a netgraph control message.
683  * Check it is one we understand. If needed, send a response.
684  * We sometimes save the address for an async action later.
685  * Always free the message.
686  */
687 static int
688 ng_pppoe_rcvmsg(node_p node, item_p item, hook_p lasthook)
689 {
690 	priv_p privp = NG_NODE_PRIVATE(node);
691 	struct ngpppoe_init_data *ourmsg = NULL;
692 	struct ng_mesg *resp = NULL;
693 	int error = 0;
694 	hook_p hook = NULL;
695 	sessp sp = NULL;
696 	negp neg = NULL;
697 	struct ng_mesg *msg;
698 
699 	DBG;
700 	NGI_GET_MSG(item, msg);
701 	/* Deal with message according to cookie and command */
702 	switch (msg->header.typecookie) {
703 	case NGM_PPPOE_COOKIE:
704 		switch (msg->header.cmd) {
705 		case NGM_PPPOE_CONNECT:
706 		case NGM_PPPOE_LISTEN:
707 		case NGM_PPPOE_OFFER:
708 		case NGM_PPPOE_SERVICE:
709 			ourmsg = (struct ngpppoe_init_data *)msg->data;
710 			if (msg->header.arglen < sizeof(*ourmsg)) {
711 				printf("pppoe: init data too small\n");
712 				LEAVE(EMSGSIZE);
713 			}
714 			if (msg->header.arglen - sizeof(*ourmsg) >
715 			    PPPOE_SERVICE_NAME_SIZE) {
716 				printf("pppoe_rcvmsg: service name too big");
717 				LEAVE(EMSGSIZE);
718 			}
719 			if (msg->header.arglen - sizeof(*ourmsg) <
720 			    ourmsg->data_len) {
721 				printf("pppoe: init data has bad length,"
722 				    " %d should be %zd\n", ourmsg->data_len,
723 				    msg->header.arglen - sizeof (*ourmsg));
724 				LEAVE(EMSGSIZE);
725 			}
726 
727 			/* make sure strcmp will terminate safely */
728 			ourmsg->hook[sizeof(ourmsg->hook) - 1] = '\0';
729 
730 			/* cycle through all known hooks */
731 			LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
732 				if (NG_HOOK_NAME(hook)
733 				&& strcmp(NG_HOOK_NAME(hook), ourmsg->hook) == 0)
734 					break;
735 			}
736 			if (hook == NULL) {
737 				LEAVE(ENOENT);
738 			}
739 			if ((NG_HOOK_PRIVATE(hook) == &privp->debug_hook)
740 			||  (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook)) {
741 				LEAVE(EINVAL);
742 			}
743 			sp = NG_HOOK_PRIVATE(hook);
744 
745 			if (msg->header.cmd == NGM_PPPOE_LISTEN) {
746 				/*
747 				 * Ensure we aren't already listening for this
748 				 * service.
749 				 */
750 				if (pppoe_match_svc(node, ourmsg->data,
751 				    ourmsg->data_len, NG_MATCH_EXACT) != NULL) {
752 					LEAVE(EEXIST);
753 				}
754 			}
755 
756 			/*
757 			 * PPPOE_SERVICE advertisments are set up
758 			 * on sessions that are in PRIMED state.
759 			 */
760 			if (msg->header.cmd == NGM_PPPOE_SERVICE) {
761 				break;
762 			}
763 			if (sp->state |= PPPOE_SNONE) {
764 				printf("pppoe: Session already active\n");
765 				LEAVE(EISCONN);
766 			}
767 
768 			/*
769 			 * set up prototype header
770 			 */
771 			MALLOC(neg, negp, sizeof(*neg), M_NETGRAPH_PPPOE,
772 			    M_NOWAIT | M_ZERO);
773 
774 			if (neg == NULL) {
775 				printf("pppoe: Session out of memory\n");
776 				LEAVE(ENOMEM);
777 			}
778 			MGETHDR(neg->m, M_DONTWAIT, MT_DATA);
779 			if(neg->m == NULL) {
780 				printf("pppoe: Session out of mbufs\n");
781 				FREE(neg, M_NETGRAPH_PPPOE);
782 				LEAVE(ENOBUFS);
783 			}
784 			neg->m->m_pkthdr.rcvif = NULL;
785 			MCLGET(neg->m, M_DONTWAIT);
786 			if ((neg->m->m_flags & M_EXT) == 0) {
787 				printf("pppoe: Session out of mcls\n");
788 				m_freem(neg->m);
789 				FREE(neg, M_NETGRAPH_PPPOE);
790 				LEAVE(ENOBUFS);
791 			}
792 			sp->neg = neg;
793 			ng_callout_init(&neg->handle);
794 			neg->m->m_len = sizeof(struct pppoe_full_hdr);
795 			neg->pkt = mtod(neg->m, union packet*);
796 			memcpy((void *)&neg->pkt->pkt_header.eh,
797 			    (const void *)privp->mode->eh_prototype,
798 			    sizeof(struct ether_header));
799 			neg->pkt->pkt_header.ph.ver = 0x1;
800 			neg->pkt->pkt_header.ph.type = 0x1;
801 			neg->pkt->pkt_header.ph.sid = 0x0000;
802 			neg->timeout = 0;
803 
804 			sp->creator = NGI_RETADDR(item);
805 		}
806 		switch (msg->header.cmd) {
807 		case NGM_PPPOE_GET_STATUS:
808 		    {
809 			struct ngpppoestat *stats;
810 
811 			NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT);
812 			if (!resp) {
813 				LEAVE(ENOMEM);
814 			}
815 			stats = (struct ngpppoestat *) resp->data;
816 			stats->packets_in = privp->packets_in;
817 			stats->packets_out = privp->packets_out;
818 			break;
819 		    }
820 		case NGM_PPPOE_CONNECT:
821 			/*
822 			 * Check the hook exists and is Uninitialised.
823 			 * Send a PADI request, and start the timeout logic.
824 			 * Store the originator of this message so we can send
825 			 * a success of fail message to them later.
826 			 * Move the session to SINIT
827 			 * Set up the session to the correct state and
828 			 * start it.
829 			 */
830 			neg->service.hdr.tag_type = PTT_SRV_NAME;
831 			neg->service.hdr.tag_len =
832 			    htons((u_int16_t)ourmsg->data_len);
833 			if (ourmsg->data_len)
834 				bcopy(ourmsg->data, neg->service.data,
835 				    ourmsg->data_len);
836 			neg->service_len = ourmsg->data_len;
837 			pppoe_start(sp);
838 			break;
839 		case NGM_PPPOE_LISTEN:
840 			/*
841 			 * Check the hook exists and is Uninitialised.
842 			 * Install the service matching string.
843 			 * Store the originator of this message so we can send
844 			 * a success of fail message to them later.
845 			 * Move the hook to 'LISTENING'
846 			 */
847 			neg->service.hdr.tag_type = PTT_SRV_NAME;
848 			neg->service.hdr.tag_len =
849 			    htons((u_int16_t)ourmsg->data_len);
850 
851 			if (ourmsg->data_len)
852 				bcopy(ourmsg->data, neg->service.data,
853 				    ourmsg->data_len);
854 			neg->service_len = ourmsg->data_len;
855 			neg->pkt->pkt_header.ph.code = PADT_CODE;
856 			/*
857 			 * wait for PADI packet coming from ethernet
858 			 */
859 			sp->state = PPPOE_LISTENING;
860 			break;
861 		case NGM_PPPOE_OFFER:
862 			/*
863 			 * Check the hook exists and is Uninitialised.
864 			 * Store the originator of this message so we can send
865 			 * a success of fail message to them later.
866 			 * Store the AC-Name given and go to PRIMED.
867 			 */
868 			neg->ac_name.hdr.tag_type = PTT_AC_NAME;
869 			neg->ac_name.hdr.tag_len =
870 			    htons((u_int16_t)ourmsg->data_len);
871 			if (ourmsg->data_len)
872 				bcopy(ourmsg->data, neg->ac_name.data,
873 				    ourmsg->data_len);
874 			neg->ac_name_len = ourmsg->data_len;
875 			neg->pkt->pkt_header.ph.code = PADO_CODE;
876 			/*
877 			 * Wait for PADI packet coming from hook
878 			 */
879 			sp->state = PPPOE_PRIMED;
880 			break;
881 		case NGM_PPPOE_SERVICE:
882 			/*
883 			 * Check the session is primed.
884 			 * for now just allow ONE service to be advertised.
885 			 * If you do it twice you just overwrite.
886 			 */
887 			if (sp->state != PPPOE_PRIMED) {
888 				printf("pppoe: Session not primed\n");
889 				LEAVE(EISCONN);
890 			}
891 			neg = sp->neg;
892 			neg->service.hdr.tag_type = PTT_SRV_NAME;
893 			neg->service.hdr.tag_len =
894 			    htons((u_int16_t)ourmsg->data_len);
895 
896 			if (ourmsg->data_len)
897 				bcopy(ourmsg->data, neg->service.data,
898 				    ourmsg->data_len);
899 			neg->service_len = ourmsg->data_len;
900 			break;
901 		case NGM_PPPOE_SETMODE:
902 		    {
903 			const struct ng_pppoe_mode_t *mode;
904 			char *s;
905 			size_t len;
906 
907 			if (msg->header.arglen == 0)
908 				LEAVE(EINVAL);
909 
910 			s = (char *)msg->data;
911 			len = msg->header.arglen - 1;
912 
913 			/* Search for matching mode string */
914 			for (mode = ng_pppoe_modes; mode->id != 0; mode++ )
915 				if ((strlen(mode->name) == len) &&
916 				    !strncmp(mode->name, s, len))
917 					break;	/* found */
918 
919 			if (mode->id != 0)
920 				privp->mode = mode;
921 			else
922 				LEAVE(EINVAL);
923 			break;
924 		    }
925 		case NGM_PPPOE_GETMODE:
926 			NG_MKRESPONSE(resp, msg, strlen(privp->mode->name) + 1,
927 			    M_NOWAIT);
928 			if (resp == NULL)
929 				LEAVE(ENOMEM);
930 			strlcpy((char *)resp->data, privp->mode->name,
931 			    strlen(privp->mode->name) + 1);
932 			break;
933 		default:
934 			LEAVE(EINVAL);
935 		}
936 		break;
937 	default:
938 		LEAVE(EINVAL);
939 	}
940 
941 	/* Take care of synchronous response, if any */
942 quit:
943 	NG_RESPOND_MSG(error, node, item, resp);
944 	/* Free the message and return */
945 	NG_FREE_MSG(msg);
946 	return(error);
947 }
948 
949 /*
950  * Start a client into the first state. A separate function because
951  * it can be needed if the negotiation times out.
952  */
953 static void
954 pppoe_start(sessp sp)
955 {
956 	priv_p	privp = NG_NODE_PRIVATE(NG_PPPOE_SESSION_NODE(sp));
957 	struct {
958 		struct pppoe_tag hdr;
959 		union	uniq	data;
960 	} __packed uniqtag;
961 
962 	/*
963 	 * kick the state machine into starting up
964 	 */
965 	DBG;
966 	sp->state = PPPOE_SINIT;
967 	/* Reset the packet header to broadcast. Since we are in a client
968 	 * mode use configured ethertype. */
969 	memcpy((void *)&sp->neg->pkt->pkt_header.eh,
970 	    (const void *)privp->mode->eh_prototype,
971 	    sizeof(struct ether_header));
972 	sp->neg->pkt->pkt_header.ph.code = PADI_CODE;
973 	uniqtag.hdr.tag_type = PTT_HOST_UNIQ;
974 	uniqtag.hdr.tag_len = htons((u_int16_t)sizeof(uniqtag.data));
975 	uniqtag.data.pointer = sp;
976 	init_tags(sp);
977 	insert_tag(sp, &uniqtag.hdr);
978 	insert_tag(sp, &sp->neg->service.hdr);
979 	make_packet(sp);
980 	sendpacket(sp);
981 }
982 
983 static int
984 send_acname(sessp sp, const struct pppoe_tag *tag)
985 {
986 	int error, tlen;
987 	struct ng_mesg *msg;
988 	struct ngpppoe_sts *sts;
989 
990 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_ACNAME,
991 	    sizeof(struct ngpppoe_sts), M_NOWAIT);
992 	if (msg == NULL)
993 		return (ENOMEM);
994 
995 	sts = (struct ngpppoe_sts *)msg->data;
996 	tlen = min(NG_HOOKSIZ - 1, ntohs(tag->tag_len));
997 	strncpy(sts->hook, tag->tag_data, tlen);
998 	sts->hook[tlen] = '\0';
999 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, 0);
1000 
1001 	return (error);
1002 }
1003 
1004 static int
1005 send_sessionid(sessp sp)
1006 {
1007 	int error;
1008 	struct ng_mesg *msg;
1009 
1010 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_SESSIONID,
1011 	    sizeof(u_int16_t), M_NOWAIT);
1012 	if (msg == NULL)
1013 		return (ENOMEM);
1014 
1015 	*(u_int16_t *)msg->data = sp->Session_ID;
1016 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, 0);
1017 
1018 	return (error);
1019 }
1020 
1021 /*
1022  * Receive data, and do something with it.
1023  * The caller will never free m, so if we use up this data
1024  * or abort we must free it.
1025  */
1026 static int
1027 ng_pppoe_rcvdata(hook_p hook, item_p item)
1028 {
1029 	node_p			node = NG_HOOK_NODE(hook);
1030 	const priv_p		privp = NG_NODE_PRIVATE(node);
1031 	sessp			sp = NG_HOOK_PRIVATE(hook);
1032 	const struct pppoe_full_hdr *wh;
1033 	const struct pppoe_hdr	*ph;
1034 	int			error = 0;
1035 	u_int16_t		session;
1036 	u_int16_t		length;
1037 	u_int8_t		code;
1038 	const struct pppoe_tag	*utag = NULL, *tag = NULL;
1039 	hook_p 			sendhook;
1040 	struct {
1041 		struct pppoe_tag hdr;
1042 		union	uniq	data;
1043 	} __packed uniqtag;
1044 	negp			neg = NULL;
1045 	struct mbuf		*m;
1046 
1047 	DBG;
1048 	NGI_GET_M(item, m);
1049 	if (NG_HOOK_PRIVATE(hook) == &privp->debug_hook) {
1050 		/*
1051 		 * Data from the debug hook gets sent without modification
1052 		 * straight to the ethernet.
1053 		 */
1054 		NG_FWD_ITEM_HOOK( error, item, privp->ethernet_hook);
1055 	 	privp->packets_out++;
1056 	} else if (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook) {
1057 		/*
1058 		 * Incoming data.
1059 		 * Dig out various fields from the packet.
1060 		 * use them to decide where to send it.
1061 		 */
1062 
1063  		privp->packets_in++;
1064 		if( m->m_len < sizeof(*wh)) {
1065 			m = m_pullup(m, sizeof(*wh)); /* Checks length */
1066 			if (m == NULL) {
1067 				printf("couldn't m_pullup\n");
1068 				LEAVE(ENOBUFS);
1069 			}
1070 		}
1071 		wh = mtod(m, struct pppoe_full_hdr *);
1072 		length = ntohs(wh->ph.length);
1073 		switch(wh->eh.ether_type) {
1074 		case	ETHERTYPE_PPPOE_STUPID_DISC: /* fall through */
1075 		case	ETHERTYPE_PPPOE_DISC:
1076 			/*
1077 			 * We need to try to make sure that the tag area
1078 			 * is contiguous, or we could wander off the end
1079 			 * of a buffer and make a mess.
1080 			 * (Linux wouldn't have this problem).
1081 			 */
1082 			if (m->m_pkthdr.len <= MHLEN) {
1083 				if( m->m_len < m->m_pkthdr.len) {
1084 					m = m_pullup(m, m->m_pkthdr.len);
1085 					if (m == NULL) {
1086 						printf("couldn't m_pullup\n");
1087 						LEAVE(ENOBUFS);
1088 					}
1089 				}
1090 			}
1091 			if (m->m_len != m->m_pkthdr.len) {
1092 				/*
1093 				 * It's not all in one piece.
1094 				 * We need to do extra work.
1095 				 * Put it into a cluster.
1096 				 */
1097 				struct mbuf *n;
1098 				n = m_dup(m, M_DONTWAIT);
1099 				m_freem(m);
1100 				m = n;
1101 				if (m) {
1102 					/* just check we got a cluster */
1103 					if (m->m_len != m->m_pkthdr.len) {
1104 						m_freem(m);
1105 						m = NULL;
1106 					}
1107 				}
1108 				if (m == NULL) {
1109 					printf("packet fragmented\n");
1110 					LEAVE(EMSGSIZE);
1111 				}
1112 			}
1113 			wh = mtod(m, struct pppoe_full_hdr *);
1114 			length = ntohs(wh->ph.length);
1115 			ph = &wh->ph;
1116 			session = ntohs(wh->ph.sid);
1117 			code = wh->ph.code;
1118 
1119 			switch(code) {
1120 			case	PADI_CODE:
1121 				/*
1122 				 * We are a server:
1123 				 * Look for a hook with the required service
1124 				 * and send the ENTIRE packet up there.
1125 				 * It should come back to a new hook in
1126 				 * PRIMED state. Look there for further
1127 				 * processing.
1128 				 */
1129 				tag = get_tag(ph, PTT_SRV_NAME);
1130 				if (tag == NULL) {
1131 					printf("no service tag\n");
1132 					LEAVE(ENETUNREACH);
1133 				}
1134 				sendhook = pppoe_match_svc(NG_HOOK_NODE(hook),
1135 			    		tag->tag_data, ntohs(tag->tag_len),
1136 					NG_MATCH_ANY);
1137 				if (sendhook) {
1138 					NG_FWD_NEW_DATA(error, item,
1139 								sendhook, m);
1140 				} else {
1141 					LEAVE(ENETUNREACH);
1142 				}
1143 				break;
1144 			case	PADO_CODE:
1145 				/*
1146 				 * We are a client:
1147 				 * Use the host_uniq tag to find the
1148 				 * hook this is in response to.
1149 				 * Received #2, now send #3
1150 				 * For now simply accept the first we receive.
1151 				 */
1152 				utag = get_tag(ph, PTT_HOST_UNIQ);
1153 				if ((utag == NULL)
1154 				|| (ntohs(utag->tag_len) != sizeof(sp))) {
1155 					printf("no host unique field\n");
1156 					LEAVE(ENETUNREACH);
1157 				}
1158 
1159 				sendhook = pppoe_finduniq(node, utag);
1160 				if (sendhook == NULL) {
1161 					printf("no matching session\n");
1162 					LEAVE(ENETUNREACH);
1163 				}
1164 
1165 				/*
1166 				 * Check the session is in the right state.
1167 				 * It needs to be in PPPOE_SINIT.
1168 				 */
1169 				sp = NG_HOOK_PRIVATE(sendhook);
1170 				if (sp->state != PPPOE_SINIT) {
1171 					printf("session in wrong state\n");
1172 					LEAVE(ENETUNREACH);
1173 				}
1174 				neg = sp->neg;
1175 				ng_uncallout(&neg->handle, node);
1176 
1177 				/*
1178 				 * This is the first time we hear
1179 				 * from the server, so note it's
1180 				 * unicast address, replacing the
1181 				 * broadcast address .
1182 				 */
1183 				bcopy(wh->eh.ether_shost,
1184 					neg->pkt->pkt_header.eh.ether_dhost,
1185 					ETHER_ADDR_LEN);
1186 				neg->timeout = 0;
1187 				neg->pkt->pkt_header.ph.code = PADR_CODE;
1188 				init_tags(sp);
1189 				insert_tag(sp, utag);      /* Host Unique */
1190 				if ((tag = get_tag(ph, PTT_AC_COOKIE)))
1191 					insert_tag(sp, tag); /* return cookie */
1192 				if ((tag = get_tag(ph, PTT_AC_NAME))) {
1193 					insert_tag(sp, tag); /* return it */
1194 					send_acname(sp, tag);
1195 				}
1196 				insert_tag(sp, &neg->service.hdr); /* Service */
1197 				scan_tags(sp, ph);
1198 				make_packet(sp);
1199 				sp->state = PPPOE_SREQ;
1200 				sendpacket(sp);
1201 				break;
1202 			case	PADR_CODE:
1203 
1204 				/*
1205 				 * We are a server:
1206 				 * Use the ac_cookie tag to find the
1207 				 * hook this is in response to.
1208 				 */
1209 				utag = get_tag(ph, PTT_AC_COOKIE);
1210 				if ((utag == NULL)
1211 				|| (ntohs(utag->tag_len) != sizeof(sp))) {
1212 					LEAVE(ENETUNREACH);
1213 				}
1214 
1215 				sendhook = pppoe_finduniq(node, utag);
1216 				if (sendhook == NULL) {
1217 					LEAVE(ENETUNREACH);
1218 				}
1219 
1220 				/*
1221 				 * Check the session is in the right state.
1222 				 * It needs to be in PPPOE_SOFFER
1223 				 * or PPPOE_NEWCONNECTED. If the latter,
1224 				 * then this is a retry by the client.
1225 				 * so be nice, and resend.
1226 				 */
1227 				sp = NG_HOOK_PRIVATE(sendhook);
1228 				if (sp->state == PPPOE_NEWCONNECTED) {
1229 					/*
1230 					 * Whoa! drop back to resend that
1231 					 * PADS packet.
1232 					 * We should still have a copy of it.
1233 					 */
1234 					sp->state = PPPOE_SOFFER;
1235 				}
1236 				if (sp->state != PPPOE_SOFFER) {
1237 					LEAVE (ENETUNREACH);
1238 					break;
1239 				}
1240 				neg = sp->neg;
1241 				ng_uncallout(&neg->handle, node);
1242 				neg->pkt->pkt_header.ph.code = PADS_CODE;
1243 				if (sp->Session_ID == 0)
1244 					neg->pkt->pkt_header.ph.sid =
1245 					    htons(sp->Session_ID
1246 						= get_new_sid(node));
1247 				send_sessionid(sp);
1248 				neg->timeout = 0;
1249 				/*
1250 				 * start working out the tags to respond with.
1251 				 */
1252 				init_tags(sp);
1253 				insert_tag(sp, &neg->ac_name.hdr); /* AC_NAME */
1254 				if ((tag = get_tag(ph, PTT_SRV_NAME)))
1255 					insert_tag(sp, tag);/* return service */
1256 				if ((tag = get_tag(ph, PTT_HOST_UNIQ)))
1257 					insert_tag(sp, tag); /* return it */
1258 				insert_tag(sp, utag);	/* ac_cookie */
1259 				scan_tags(sp, ph);
1260 				make_packet(sp);
1261 				sp->state = PPPOE_NEWCONNECTED;
1262 				sendpacket(sp);
1263 				/*
1264 				 * Having sent the last Negotiation header,
1265 				 * Set up the stored packet header to
1266 				 * be correct for the actual session.
1267 				 * But keep the negotialtion stuff
1268 				 * around in case we need to resend this last
1269 				 * packet. We'll discard it when we move
1270 				 * from NEWCONNECTED to CONNECTED
1271 				 */
1272 				sp->pkt_hdr = neg->pkt->pkt_header;
1273 				/* Configure ethertype depending on what
1274 				 * ethertype was used at discovery phase */
1275 				if (sp->pkt_hdr.eh.ether_type ==
1276 				    ETHERTYPE_PPPOE_STUPID_DISC)
1277 					sp->pkt_hdr.eh.ether_type
1278 						= ETHERTYPE_PPPOE_STUPID_SESS;
1279 				else
1280 					sp->pkt_hdr.eh.ether_type
1281 						= ETHERTYPE_PPPOE_SESS;
1282 				sp->pkt_hdr.ph.code = 0;
1283 				pppoe_send_event(sp, NGM_PPPOE_SUCCESS);
1284 				break;
1285 			case	PADS_CODE:
1286 				/*
1287 				 * We are a client:
1288 				 * Use the host_uniq tag to find the
1289 				 * hook this is in response to.
1290 				 * take the session ID and store it away.
1291 				 * Also make sure the pre-made header is
1292 				 * correct and set us into Session mode.
1293 				 */
1294 				utag = get_tag(ph, PTT_HOST_UNIQ);
1295 				if ((utag == NULL)
1296 				|| (ntohs(utag->tag_len) != sizeof(sp))) {
1297 					LEAVE (ENETUNREACH);
1298 					break;
1299 				}
1300 				sendhook = pppoe_finduniq(node, utag);
1301 				if (sendhook == NULL) {
1302 					LEAVE(ENETUNREACH);
1303 				}
1304 
1305 				/*
1306 				 * Check the session is in the right state.
1307 				 * It needs to be in PPPOE_SREQ.
1308 				 */
1309 				sp = NG_HOOK_PRIVATE(sendhook);
1310 				if (sp->state != PPPOE_SREQ) {
1311 					LEAVE(ENETUNREACH);
1312 				}
1313 				neg = sp->neg;
1314 				ng_uncallout(&neg->handle, node);
1315 				neg->pkt->pkt_header.ph.sid = wh->ph.sid;
1316 				sp->Session_ID = ntohs(wh->ph.sid);
1317 				send_sessionid(sp);
1318 				neg->timeout = 0;
1319 				sp->state = PPPOE_CONNECTED;
1320 				/*
1321 				 * Now we have gone to Connected mode,
1322 				 * Free all resources needed for
1323 				 * negotiation.
1324 				 * Keep a copy of the header we will be using.
1325 				 */
1326 				sp->pkt_hdr = neg->pkt->pkt_header;
1327 				if (privp->mode->id == PPPOE_NONSTANDARD)
1328 					sp->pkt_hdr.eh.ether_type
1329 						= ETHERTYPE_PPPOE_STUPID_SESS;
1330 				else
1331 					sp->pkt_hdr.eh.ether_type
1332 						= ETHERTYPE_PPPOE_SESS;
1333 				sp->pkt_hdr.ph.code = 0;
1334 				m_freem(neg->m);
1335 				FREE(sp->neg, M_NETGRAPH_PPPOE);
1336 				sp->neg = NULL;
1337 				pppoe_send_event(sp, NGM_PPPOE_SUCCESS);
1338 				break;
1339 			case	PADT_CODE:
1340 				/*
1341 				 * Send a 'close' message to the controlling
1342 				 * process (the one that set us up);
1343 				 * And then tear everything down.
1344 				 *
1345 				 * Find matching peer/session combination.
1346 				 */
1347 				sendhook = pppoe_findsession(node, wh);
1348 				if (sendhook == NULL) {
1349 					LEAVE(ENETUNREACH);
1350 				}
1351 				/* send message to creator */
1352 				/* close hook */
1353 				if (sendhook) {
1354 					ng_rmhook_self(sendhook);
1355 				}
1356 				break;
1357 			default:
1358 				LEAVE(EPFNOSUPPORT);
1359 			}
1360 			break;
1361 		case	ETHERTYPE_PPPOE_STUPID_SESS:
1362 		case	ETHERTYPE_PPPOE_SESS:
1363 			/*
1364 			 * find matching peer/session combination.
1365 			 */
1366 			sendhook = pppoe_findsession(node, wh);
1367 			if (sendhook == NULL) {
1368 				LEAVE (ENETUNREACH);
1369 				break;
1370 			}
1371 			sp = NG_HOOK_PRIVATE(sendhook);
1372 			m_adj(m, sizeof(*wh));
1373 			if (m->m_pkthdr.len < length) {
1374 				/* Packet too short, dump it */
1375 				LEAVE(EMSGSIZE);
1376 			}
1377 
1378 			/* Also need to trim excess at the end */
1379 			if (m->m_pkthdr.len > length) {
1380 				m_adj(m, -((int)(m->m_pkthdr.len - length)));
1381 			}
1382 			if ( sp->state != PPPOE_CONNECTED) {
1383 				if (sp->state == PPPOE_NEWCONNECTED) {
1384 					sp->state = PPPOE_CONNECTED;
1385 					/*
1386 					 * Now we have gone to Connected mode,
1387 					 * Free all resources needed for
1388 					 * negotiation. Be paranoid about
1389 					 * whether there may be a timeout.
1390 					 */
1391 					m_freem(sp->neg->m);
1392 					ng_uncallout(&sp->neg->handle, node);
1393 					FREE(sp->neg, M_NETGRAPH_PPPOE);
1394 					sp->neg = NULL;
1395 				} else {
1396 					LEAVE (ENETUNREACH);
1397 					break;
1398 				}
1399 			}
1400 			NG_FWD_NEW_DATA( error, item, sendhook, m);
1401 			break;
1402 		default:
1403 			LEAVE(EPFNOSUPPORT);
1404 		}
1405 	} else {
1406 		/*
1407 		 * 	Not ethernet or debug hook..
1408 		 *
1409 		 * The packet has come in on a normal hook.
1410 		 * We need to find out what kind of hook,
1411 		 * So we can decide how to handle it.
1412 		 * Check the hook's state.
1413 		 */
1414 		sp = NG_HOOK_PRIVATE(hook);
1415 		switch (sp->state) {
1416 		case	PPPOE_NEWCONNECTED:
1417 		case	PPPOE_CONNECTED: {
1418 			static const u_char addrctrl[] = { 0xff, 0x03 };
1419 			struct pppoe_full_hdr *wh;
1420 
1421 			/*
1422 			 * Remove PPP address and control fields, if any.
1423 			 * For example, ng_ppp(4) always sends LCP packets
1424 			 * with address and control fields as required by
1425 			 * generic PPP. PPPoE is an exception to the rule.
1426 			 */
1427 			if (m->m_pkthdr.len >= 2) {
1428 				if (m->m_len < 2 && !(m = m_pullup(m, 2)))
1429 					LEAVE(ENOBUFS);
1430 				if (bcmp(mtod(m, u_char *), addrctrl, 2) == 0)
1431 					m_adj(m, 2);
1432 			}
1433 			/*
1434 			 * Bang in a pre-made header, and set the length up
1435 			 * to be correct. Then send it to the ethernet driver.
1436 			 * But first correct the length.
1437 			 */
1438 			sp->pkt_hdr.ph.length = htons((short)(m->m_pkthdr.len));
1439 			M_PREPEND(m, sizeof(*wh), M_DONTWAIT);
1440 			if (m == NULL) {
1441 				LEAVE(ENOBUFS);
1442 			}
1443 			wh = mtod(m, struct pppoe_full_hdr *);
1444 			bcopy(&sp->pkt_hdr, wh, sizeof(*wh));
1445 			NG_FWD_NEW_DATA( error, item, privp->ethernet_hook, m);
1446 			privp->packets_out++;
1447 			break;
1448 			}
1449 		case	PPPOE_PRIMED:
1450 			/*
1451 			 * A PADI packet is being returned by the application
1452 			 * that has set up this hook. This indicates that it
1453 			 * wants us to offer service.
1454 			 */
1455 			neg = sp->neg;
1456 			if (m->m_len < sizeof(*wh)) {
1457 				m = m_pullup(m, sizeof(*wh));
1458 				if (m == NULL) {
1459 					LEAVE(ENOBUFS);
1460 				}
1461 			}
1462 			wh = mtod(m, struct pppoe_full_hdr *);
1463 			ph = &wh->ph;
1464 			session = ntohs(wh->ph.sid);
1465 			length = ntohs(wh->ph.length);
1466 			code = wh->ph.code;
1467 			/* Use peers mode in session */
1468 			neg->pkt->pkt_header.eh.ether_type = wh->eh.ether_type;
1469 			if ( code != PADI_CODE) {
1470 				LEAVE(EINVAL);
1471 			};
1472 			ng_uncallout(&neg->handle, node);
1473 
1474 			/*
1475 			 * This is the first time we hear
1476 			 * from the client, so note it's
1477 			 * unicast address, replacing the
1478 			 * broadcast address.
1479 			 */
1480 			bcopy(wh->eh.ether_shost,
1481 				neg->pkt->pkt_header.eh.ether_dhost,
1482 				ETHER_ADDR_LEN);
1483 			sp->state = PPPOE_SOFFER;
1484 			neg->timeout = 0;
1485 			neg->pkt->pkt_header.ph.code = PADO_CODE;
1486 
1487 			/*
1488 			 * start working out the tags to respond with.
1489 			 */
1490 			uniqtag.hdr.tag_type = PTT_AC_COOKIE;
1491 			uniqtag.hdr.tag_len = htons((u_int16_t)sizeof(sp));
1492 			uniqtag.data.pointer = sp;
1493 			init_tags(sp);
1494 			insert_tag(sp, &neg->ac_name.hdr); /* AC_NAME */
1495 			if ((tag = get_tag(ph, PTT_SRV_NAME)))
1496 				insert_tag(sp, tag);	  /* return service */
1497 			/*
1498 			 * If we have a NULL service request
1499 			 * and have an extra service defined in this hook,
1500 			 * then also add a tag for the extra service.
1501 			 * XXX this is a hack. eventually we should be able
1502 			 * to support advertising many services, not just one
1503 			 */
1504 			if (((tag == NULL) || (tag->tag_len == 0))
1505 			&& (neg->service.hdr.tag_len != 0)) {
1506 				insert_tag(sp, &neg->service.hdr); /* SERVICE */
1507 			}
1508 			if ((tag = get_tag(ph, PTT_HOST_UNIQ)))
1509 				insert_tag(sp, tag); /* returned hostunique */
1510 			insert_tag(sp, &uniqtag.hdr);
1511 			scan_tags(sp, ph);
1512 			make_packet(sp);
1513 			sendpacket(sp);
1514 			break;
1515 
1516 		/*
1517 		 * Packets coming from the hook make no sense
1518 		 * to sessions in these states. Throw them away.
1519 		 */
1520 		case	PPPOE_SINIT:
1521 		case	PPPOE_SREQ:
1522 		case	PPPOE_SOFFER:
1523 		case	PPPOE_SNONE:
1524 		case	PPPOE_LISTENING:
1525 		case	PPPOE_DEAD:
1526 		default:
1527 			LEAVE(ENETUNREACH);
1528 		}
1529 	}
1530 quit:
1531 	if (item)
1532 		NG_FREE_ITEM(item);
1533 	NG_FREE_M(m);
1534 	return error;
1535 }
1536 
1537 /*
1538  * Do local shutdown processing..
1539  * If we are a persistant device, we might refuse to go away, and
1540  * we'd only remove our links and reset ourself.
1541  */
1542 static int
1543 ng_pppoe_shutdown(node_p node)
1544 {
1545 	const priv_p privdata = NG_NODE_PRIVATE(node);
1546 
1547 	DBG;
1548 	NG_NODE_SET_PRIVATE(node, NULL);
1549 	NG_NODE_UNREF(privdata->node);
1550 	FREE(privdata, M_NETGRAPH_PPPOE);
1551 	return (0);
1552 }
1553 
1554 /*
1555  * This is called once we've already connected a new hook to the other node.
1556  * It gives us a chance to balk at the last minute.
1557  */
1558 static int
1559 ng_pppoe_connect(hook_p hook)
1560 {
1561 	/* be really amiable and just say "YUP that's OK by me! " */
1562 	return (0);
1563 }
1564 
1565 /*
1566  * Hook disconnection
1567  *
1568  * Clean up all dangling links and information about the session/hook.
1569  * For this type, removal of the last link destroys the node
1570  */
1571 static int
1572 ng_pppoe_disconnect(hook_p hook)
1573 {
1574 	node_p node = NG_HOOK_NODE(hook);
1575 	priv_p privp = NG_NODE_PRIVATE(node);
1576 	sessp	sp;
1577 	int 	hooks;
1578 
1579 	DBG;
1580 	hooks = NG_NODE_NUMHOOKS(node); /* this one already not counted */
1581 	if (NG_HOOK_PRIVATE(hook) == &privp->debug_hook) {
1582 		privp->debug_hook = NULL;
1583 	} else if (NG_HOOK_PRIVATE(hook) == &privp->ethernet_hook) {
1584 		privp->ethernet_hook = NULL;
1585 		if (NG_NODE_IS_VALID(node))
1586 			ng_rmnode_self(node);
1587 	} else {
1588 		sp = NG_HOOK_PRIVATE(hook);
1589 		if (sp->state != PPPOE_SNONE ) {
1590 			pppoe_send_event(sp, NGM_PPPOE_CLOSE);
1591 		}
1592 		/*
1593 		 * According to the spec, if we are connected,
1594 		 * we should send a DISC packet if we are shutting down
1595 		 * a session.
1596 		 */
1597 		if ((privp->ethernet_hook)
1598 		&& ((sp->state == PPPOE_CONNECTED)
1599 		 || (sp->state == PPPOE_NEWCONNECTED))) {
1600 			struct mbuf *m;
1601 			struct pppoe_full_hdr *wh;
1602 			struct pppoe_tag *tag;
1603 			int	msglen = strlen(SIGNOFF);
1604 			int error = 0;
1605 
1606 			/* revert the stored header to DISC/PADT mode */
1607 		 	wh = &sp->pkt_hdr;
1608 			wh->ph.code = PADT_CODE;
1609 			/* Configure ethertype depending on what was used during
1610 			 * sessions stage. */
1611 			if (sp->pkt_hdr.eh.ether_type ==
1612 			    ETHERTYPE_PPPOE_STUPID_SESS)
1613 				wh->eh.ether_type = ETHERTYPE_PPPOE_STUPID_DISC;
1614 			else
1615 				wh->eh.ether_type = ETHERTYPE_PPPOE_DISC;
1616 
1617 			/* generate a packet of that type */
1618 			MGETHDR(m, M_DONTWAIT, MT_DATA);
1619 			if(m == NULL)
1620 				printf("pppoe: Session out of mbufs\n");
1621 			else {
1622 				m->m_pkthdr.rcvif = NULL;
1623 				m->m_pkthdr.len = m->m_len = sizeof(*wh);
1624 				bcopy((caddr_t)wh, mtod(m, caddr_t),
1625 				    sizeof(*wh));
1626 				/*
1627 				 * Add a General error message and adjust
1628 				 * sizes
1629 				 */
1630 				wh = mtod(m, struct pppoe_full_hdr *);
1631 				tag = wh->ph.tag;
1632 				tag->tag_type = PTT_GEN_ERR;
1633 				tag->tag_len = htons((u_int16_t)msglen);
1634 				strncpy(tag->tag_data, SIGNOFF, msglen);
1635 				m->m_pkthdr.len = (m->m_len += sizeof(*tag) +
1636 				    msglen);
1637 				wh->ph.length = htons(sizeof(*tag) + msglen);
1638 				NG_SEND_DATA_ONLY(error,
1639 					privp->ethernet_hook, m);
1640 			}
1641 		}
1642 		/*
1643 		 * As long as we have somewhere to store the timeout handle,
1644 		 * we may have a timeout pending.. get rid of it.
1645 		 */
1646 		if (sp->neg) {
1647 			ng_uncallout(&sp->neg->handle, node);
1648 			if (sp->neg->m)
1649 				m_freem(sp->neg->m);
1650 			FREE(sp->neg, M_NETGRAPH_PPPOE);
1651 		}
1652 		FREE(sp, M_NETGRAPH_PPPOE);
1653 		NG_HOOK_SET_PRIVATE(hook, NULL);
1654 		/* work out how many session hooks there are */
1655 		/* Node goes away on last session hook removal */
1656 		if (privp->ethernet_hook) hooks -= 1;
1657 		if (privp->debug_hook) hooks -= 1;
1658 	}
1659 	if ((NG_NODE_NUMHOOKS(node) == 0)
1660 	&& (NG_NODE_IS_VALID(node)))
1661 		ng_rmnode_self(node);
1662 	return (0);
1663 }
1664 
1665 /*
1666  * timeouts come here.
1667  */
1668 static void
1669 pppoe_ticker(node_p node, hook_p hook, void *arg1, int arg2)
1670 {
1671 	sessp	sp = NG_HOOK_PRIVATE(hook);
1672 	negp	neg = sp->neg;
1673 	int	error = 0;
1674 	struct mbuf *m0 = NULL;
1675 	priv_p privp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
1676 
1677 	DBG;
1678 	switch(sp->state) {
1679 		/*
1680 		 * resend the last packet, using an exponential backoff.
1681 		 * After a period of time, stop growing the backoff,
1682 		 * and either leave it, or revert to the start.
1683 		 */
1684 	case	PPPOE_SINIT:
1685 	case	PPPOE_SREQ:
1686 		/* timeouts on these produce resends */
1687 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1688 		NG_SEND_DATA_ONLY( error, privp->ethernet_hook, m0);
1689 		ng_callout(&neg->handle, node, hook, neg->timeout * hz,
1690 		    pppoe_ticker, NULL, 0);
1691 		if ((neg->timeout <<= 1) > PPPOE_TIMEOUT_LIMIT) {
1692 			if (sp->state == PPPOE_SREQ) {
1693 				/* revert to SINIT mode */
1694 				pppoe_start(sp);
1695 			} else {
1696 				neg->timeout = PPPOE_TIMEOUT_LIMIT;
1697 			}
1698 		}
1699 		break;
1700 	case	PPPOE_PRIMED:
1701 	case	PPPOE_SOFFER:
1702 		/* a timeout on these says "give up" */
1703 		ng_rmhook_self(hook);
1704 		break;
1705 	default:
1706 		/* timeouts have no meaning in other states */
1707 		printf("pppoe: unexpected timeout\n");
1708 	}
1709 }
1710 
1711 
1712 static void
1713 sendpacket(sessp sp)
1714 {
1715 	struct	mbuf *m0 = NULL;
1716 	hook_p	hook = sp->hook;
1717 	node_p	node = NG_HOOK_NODE(hook);
1718 	priv_p	privp = NG_NODE_PRIVATE(node);
1719 	negp	neg = sp->neg;
1720 	int	error = 0;
1721 
1722 	DBG;
1723 	switch(sp->state) {
1724 	case	PPPOE_LISTENING:
1725 	case	PPPOE_DEAD:
1726 	case	PPPOE_SNONE:
1727 	case	PPPOE_CONNECTED:
1728 		printf("pppoe: sendpacket: unexpected state\n");
1729 		break;
1730 
1731 	case	PPPOE_NEWCONNECTED:
1732 		/* send the PADS without a timeout - we're now connected */
1733 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1734 		NG_SEND_DATA_ONLY( error, privp->ethernet_hook, m0);
1735 		break;
1736 
1737 	case	PPPOE_PRIMED:
1738 		/* No packet to send, but set up the timeout */
1739 		ng_callout(&neg->handle, node, hook, PPPOE_OFFER_TIMEOUT * hz,
1740 		    pppoe_ticker, NULL, 0);
1741 		break;
1742 
1743 	case	PPPOE_SOFFER:
1744 		/*
1745 		 * send the offer but if they don't respond
1746 		 * in PPPOE_OFFER_TIMEOUT seconds, forget about it.
1747 		 */
1748 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1749 		NG_SEND_DATA_ONLY( error, privp->ethernet_hook, m0);
1750 		ng_callout(&neg->handle, node, hook, PPPOE_OFFER_TIMEOUT * hz,
1751 		    pppoe_ticker, NULL, 0);
1752 		break;
1753 
1754 	case	PPPOE_SINIT:
1755 	case	PPPOE_SREQ:
1756 		m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1757 		NG_SEND_DATA_ONLY( error, privp->ethernet_hook, m0);
1758 		ng_callout(&neg->handle, node, hook, PPPOE_INITIAL_TIMEOUT * hz,
1759 		    pppoe_ticker, NULL, 0);
1760 		neg->timeout = PPPOE_INITIAL_TIMEOUT * 2;
1761 		break;
1762 
1763 	default:
1764 		error = EINVAL;
1765 		printf("pppoe: timeout: bad state\n");
1766 	}
1767 	/* return (error); */
1768 }
1769 
1770 /*
1771  * Parse an incoming packet to see if any tags should be copied to the
1772  * output packet. Don't do any tags that have been handled in the main
1773  * state machine.
1774  */
1775 static const struct pppoe_tag*
1776 scan_tags(sessp	sp, const struct pppoe_hdr* ph)
1777 {
1778 	const char *const end = (const char *)next_tag(ph);
1779 	const char *ptn;
1780 	const struct pppoe_tag *pt = &ph->tag[0];
1781 	/*
1782 	 * Keep processing tags while a tag header will still fit.
1783 	 */
1784 	DBG;
1785 	while((const char*)(pt + 1) <= end) {
1786 		/*
1787 		 * If the tag data would go past the end of the packet, abort.
1788 		 */
1789 		ptn = (((const char *)(pt + 1)) + ntohs(pt->tag_len));
1790 		if(ptn > end)
1791 			return NULL;
1792 
1793 		switch (pt->tag_type) {
1794 		case	PTT_RELAY_SID:
1795 			insert_tag(sp, pt);
1796 			break;
1797 		case	PTT_EOL:
1798 			return NULL;
1799 		case	PTT_SRV_NAME:
1800 		case	PTT_AC_NAME:
1801 		case	PTT_HOST_UNIQ:
1802 		case	PTT_AC_COOKIE:
1803 		case	PTT_VENDOR:
1804 		case	PTT_SRV_ERR:
1805 		case	PTT_SYS_ERR:
1806 		case	PTT_GEN_ERR:
1807 			break;
1808 		}
1809 		pt = (const struct pppoe_tag*)ptn;
1810 	}
1811 	return NULL;
1812 }
1813 
1814 static	int
1815 pppoe_send_event(sessp sp, enum cmd cmdid)
1816 {
1817 	int error;
1818 	struct ng_mesg *msg;
1819 	struct ngpppoe_sts *sts;
1820 
1821 	DBG;
1822 	NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, cmdid,
1823 			sizeof(struct ngpppoe_sts), M_NOWAIT);
1824 	if (msg == NULL)
1825 		return (ENOMEM);
1826 	sts = (struct ngpppoe_sts *)msg->data;
1827 	strncpy(sts->hook, NG_HOOK_NAME(sp->hook), NG_HOOKSIZ);
1828 	NG_SEND_MSG_ID(error, NG_HOOK_NODE(sp->hook), msg, sp->creator, 0);
1829 	return (error);
1830 }
1831