xref: /netbsd/sys/net/if_pppoe.c (revision bf9ec67e)
1 /* $NetBSD: if_pppoe.c,v 1.24 2002/04/14 12:24:28 martin Exp $ */
2 
3 /*-
4  * Copyright (c) 2002 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Martin Husemann <martin@netbsd.org>.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 __KERNEL_RCSID(0, "$NetBSD: if_pppoe.c,v 1.24 2002/04/14 12:24:28 martin Exp $");
41 
42 #include "pppoe.h"
43 #include "bpfilter.h"
44 
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/kernel.h>
48 #include <sys/callout.h>
49 #include <sys/malloc.h>
50 #include <sys/mbuf.h>
51 #include <sys/socket.h>
52 #include <sys/proc.h>
53 #include <sys/ioctl.h>
54 #include <net/if.h>
55 #include <net/if_types.h>
56 #include <net/if_ether.h>
57 #include <net/if_sppp.h>
58 #include <net/if_spppvar.h>
59 #include <net/if_pppoe.h>
60 
61 #if NBPFILTER > 0
62 #include <net/bpf.h>
63 #endif
64 
65 #include <machine/intr.h>
66 
67 #undef PPPOE_DEBUG		/* XXX - remove this or make it an option */
68 /* #define PPPOE_DEBUG 1 */
69 
70 #define PPPOE_HEADERLEN	6
71 #define	PPPOE_VERTYPE	0x11	/* VER=1, TYPE = 1 */
72 
73 #define	PPPOE_TAG_EOL		0x0000		/* end of list */
74 #define	PPPOE_TAG_SNAME		0x0101		/* service name */
75 #define	PPPOE_TAG_ACNAME	0x0102		/* access concentrator name */
76 #define	PPPOE_TAG_HUNIQUE	0x0103		/* host unique */
77 #define	PPPOE_TAG_ACCOOKIE	0x0104		/* AC cookie */
78 #define	PPPOE_TAG_VENDOR	0x0105		/* vendor specific */
79 #define	PPPOE_TAG_RELAYSID	0x0110		/* relay session id */
80 #define	PPPOE_TAG_SNAME_ERR	0x0201		/* service name error */
81 #define	PPPOE_TAG_ACSYS_ERR	0x0202		/* AC system error */
82 #define	PPPOE_TAG_GENERIC_ERR	0x0203		/* gerneric error */
83 
84 #define PPPOE_CODE_PADI		0x09		/* Active Discovery Initiation */
85 #define	PPPOE_CODE_PADO		0x07		/* Active Discovery Offer */
86 #define	PPPOE_CODE_PADR		0x19		/* Active Discovery Request */
87 #define	PPPOE_CODE_PADS		0x65		/* Active Discovery Session confirmation */
88 #define	PPPOE_CODE_PADT		0xA7		/* Active Discovery Terminate */
89 
90 /* two byte PPP protocol discriminator, then IP data */
91 #define	PPPOE_MAXMTU	(ETHERMTU-PPPOE_HEADERLEN-2)
92 
93 /* Read a 16 bit unsigned value from a buffer */
94 #define PPPOE_READ_16(PTR, VAL)				\
95 		(VAL) = ((PTR)[0] << 8) | (PTR)[1];	\
96 		(PTR)+=2
97 
98 /* Add a 16 bit unsigned value to a buffer pointed to by PTR */
99 #define	PPPOE_ADD_16(PTR, VAL)			\
100 		*(PTR)++ = (VAL) / 256;		\
101 		*(PTR)++ = (VAL) % 256
102 
103 /* Add a complete PPPoE header to the buffer pointed to by PTR */
104 #define PPPOE_ADD_HEADER(PTR, CODE, SESS, LEN)	\
105 		*(PTR)++ = PPPOE_VERTYPE;	\
106 		*(PTR)++ = (CODE);		\
107 		PPPOE_ADD_16(PTR, SESS);	\
108 		PPPOE_ADD_16(PTR, LEN)
109 
110 #define	PPPOE_DISC_TIMEOUT	(hz*5)	/* base for quick timeout calculation */
111 #define	PPPOE_SLOW_RETRY	(hz*60)	/* persistent retry interval */
112 #define PPPOE_DISC_MAXPADI	4	/* retry PADI four times (quickly) */
113 #define	PPPOE_DISC_MAXPADR	2	/* retry PADR twice */
114 
115 struct pppoe_softc {
116 	struct sppp sc_sppp;		/* contains a struct ifnet as first element */
117 	LIST_ENTRY(pppoe_softc) sc_list;
118 	struct ifnet *sc_eth_if;	/* ethernet interface we are using */
119 
120 	int sc_state;			/* discovery phase or session connected */
121 	struct ether_addr sc_dest;	/* hardware address of concentrator */
122 	u_int16_t sc_session;		/* PPPoE session id */
123 
124 	char *sc_service_name;		/* if != NULL: requested name of service */
125 	char *sc_concentrator_name;	/* if != NULL: requested concentrator id */
126 	u_int8_t *sc_ac_cookie;		/* content of AC cookie we must echo back */
127 	size_t sc_ac_cookie_len;	/* length of cookie data */
128 	struct callout sc_timeout;	/* timeout while not in session state */
129 	int sc_padi_retried;		/* number of PADI retries already done */
130 	int sc_padr_retried;		/* number of PADR retries already done */
131 };
132 
133 /* incoming traffic will be queued here */
134 struct ifqueue ppoediscinq = { NULL };
135 struct ifqueue ppoeinq = { NULL };
136 
137 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
138 void * pppoe_softintr = NULL;
139 static void pppoe_softintr_handler(void *);
140 #else
141 struct callout pppoe_softintr = CALLOUT_INITIALIZER;
142 void pppoe_softintr_handler(void*);
143 #endif
144 
145 extern int sppp_ioctl(struct ifnet *ifp, unsigned long cmd, void *data);
146 
147 /* input routines */
148 static void pppoe_input(void);
149 static void pppoe_disc_input(struct mbuf *m);
150 static void pppoe_dispatch_disc_pkt(u_int8_t *p, size_t size, struct ifnet *rcvif, struct ether_header *eh);
151 static void pppoe_data_input(struct mbuf *m);
152 
153 /* management routines */
154 void pppoeattach(int count);
155 static int pppoe_connect(struct pppoe_softc *sc);
156 static int pppoe_disconnect(struct pppoe_softc *sc);
157 static void pppoe_abort_connect(struct pppoe_softc *sc);
158 static int pppoe_ioctl(struct ifnet *ifp, unsigned long cmd, caddr_t data);
159 static void pppoe_tls(struct sppp *sp);
160 static void pppoe_tlf(struct sppp *sp);
161 static void pppoe_start(struct ifnet *ifp);
162 
163 /* internal timeout handling */
164 static void pppoe_timeout(void*);
165 
166 /* sending actual protocol controll packets */
167 static int pppoe_send_padi(struct pppoe_softc *sc);
168 static int pppoe_send_padr(struct pppoe_softc *sc);
169 static int pppoe_send_padt(struct pppoe_softc *sc);
170 
171 /* raw output */
172 static int pppoe_output(struct pppoe_softc *sc, struct mbuf *m);
173 
174 /* internal helper functions */
175 static struct pppoe_softc * pppoe_find_softc_by_session(u_int session, struct ifnet *rcvif);
176 static struct pppoe_softc * pppoe_find_softc_by_hunique(u_int8_t *token, size_t len, struct ifnet *rcvif);
177 
178 LIST_HEAD(pppoe_softc_head, pppoe_softc) pppoe_softc_list;
179 
180 int     pppoe_clone_create __P((struct if_clone *, int));
181 void    pppoe_clone_destroy __P((struct ifnet *));
182 
183 struct if_clone pppoe_cloner =
184     IF_CLONE_INITIALIZER("pppoe", pppoe_clone_create, pppoe_clone_destroy);
185 
186 /* ARGSUSED */
187 void
188 pppoeattach(count)
189 	int count;
190 {
191 	LIST_INIT(&pppoe_softc_list);
192 	if_clone_attach(&pppoe_cloner);
193 
194 	ppoediscinq.ifq_maxlen = IFQ_MAXLEN;
195 	ppoeinq.ifq_maxlen = IFQ_MAXLEN;
196 
197 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
198 	pppoe_softintr = softintr_establish(IPL_SOFTNET, pppoe_softintr_handler, NULL);
199 #endif
200 }
201 
202 int
203 pppoe_clone_create(ifc, unit)
204 	struct if_clone *ifc;
205 	int unit;
206 {
207 	struct pppoe_softc *sc;
208 
209 	sc = malloc(sizeof(struct pppoe_softc), M_DEVBUF, M_WAITOK);
210 	memset(sc, 0, sizeof(struct pppoe_softc));
211 
212 	sprintf(sc->sc_sppp.pp_if.if_xname, "pppoe%d", unit);
213 	sc->sc_sppp.pp_if.if_softc = sc;
214 	sc->sc_sppp.pp_if.if_mtu = PPPOE_MAXMTU;
215 	sc->sc_sppp.pp_if.if_flags = IFF_SIMPLEX|IFF_POINTOPOINT|IFF_MULTICAST;
216 	sc->sc_sppp.pp_if.if_type = IFT_PPP;
217 	sc->sc_sppp.pp_if.if_hdrlen = sizeof(struct ether_header)+PPPOE_HEADERLEN;
218 	sc->sc_sppp.pp_if.if_dlt = DLT_PPP_ETHER;
219 	sc->sc_sppp.pp_flags |= PP_KEEPALIVE|	/* use LCP keepalive */
220 				PP_NOFRAMING;	/* no serial encapsulation */
221 	sc->sc_sppp.pp_if.if_ioctl = pppoe_ioctl;
222 	IFQ_SET_MAXLEN(&sc->sc_sppp.pp_if.if_snd, IFQ_MAXLEN);
223 	IFQ_SET_READY(&sc->sc_sppp.pp_if.if_snd);
224 
225 	/* changed to real address later */
226 	memcpy(&sc->sc_dest, etherbroadcastaddr, sizeof(sc->sc_dest));
227 
228 	callout_init(&sc->sc_timeout);
229 
230 	sc->sc_sppp.pp_if.if_start = pppoe_start;
231 	sc->sc_sppp.pp_tls = pppoe_tls;
232 	sc->sc_sppp.pp_tlf = pppoe_tlf;
233 	sc->sc_sppp.pp_framebytes = PPPOE_HEADERLEN;	/* framing added to ppp packets */
234 
235 	if_attach(&sc->sc_sppp.pp_if);
236 	sppp_attach(&sc->sc_sppp.pp_if);
237 
238 #if NBPFILTER > 0
239 	bpfattach(&sc->sc_sppp.pp_if, DLT_PPP_ETHER, 0);
240 #endif
241 	LIST_INSERT_HEAD(&pppoe_softc_list, sc, sc_list);
242 	return 0;
243 }
244 
245 void
246 pppoe_clone_destroy(ifp)
247 	struct ifnet *ifp;
248 {
249 	struct pppoe_softc * sc = ifp->if_softc;
250 
251 	LIST_REMOVE(sc, sc_list);
252 #if NBPFILTER > 0
253 	bpfdetach(ifp);
254 #endif
255 	sppp_detach(&sc->sc_sppp.pp_if);
256 	if_detach(ifp);
257 	free(sc, M_DEVBUF);
258 }
259 
260 /*
261  * Find the interface handling the specified session.
262  * Note: O(number of sessions open), this is a client-side only, mean
263  * and lean implementation, so number of open sessions typically should
264  * be 1.
265  */
266 static struct pppoe_softc *
267 pppoe_find_softc_by_session(u_int session, struct ifnet *rcvif)
268 {
269 	struct pppoe_softc *sc;
270 
271 	if (session == 0) return NULL;
272 
273 	LIST_FOREACH(sc, &pppoe_softc_list, sc_list) {
274 		if (sc->sc_state == PPPOE_STATE_SESSION
275 		    && sc->sc_session == session) {
276 			if (sc->sc_eth_if == rcvif)
277 				return sc;
278 			else
279 				return NULL;
280 		}
281 	}
282 	return NULL;
283 }
284 
285 /* Check host unique token passed and return appropriate softc pointer,
286  * or NULL if token is bogus. */
287 static struct pppoe_softc *
288 pppoe_find_softc_by_hunique(u_int8_t *token, size_t len, struct ifnet *rcvif)
289 {
290 	struct pppoe_softc *sc, *t;
291 
292 	if (LIST_EMPTY(&pppoe_softc_list)) return NULL;
293 
294 	if (len != sizeof sc) return NULL;
295 	memcpy(&t, token, len);
296 
297 	LIST_FOREACH(sc, &pppoe_softc_list, sc_list)
298 		if (sc == t) break;
299 
300 	if (sc != t) {
301 #ifdef PPPOE_DEBUG
302 		printf("pppoe: alien host unique tag, no session found\n");
303 #endif
304 		return NULL;
305 	}
306 
307 	/* should be safe to access *sc now */
308 	if (sc->sc_state < PPPOE_STATE_PADI_SENT || sc->sc_state >= PPPOE_STATE_SESSION) {
309 		printf("%s: host unique tag found, but it belongs to a connection in state %d\n",
310 			sc->sc_sppp.pp_if.if_xname, sc->sc_state);
311 		return NULL;
312 	}
313 	if (sc->sc_eth_if != rcvif) {
314 		printf("%s: wrong interface, not accepting host unique\n",
315 			sc->sc_sppp.pp_if.if_xname);
316 		return NULL;
317 	}
318 	return sc;
319 }
320 
321 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
322 static void pppoe_softintr_handler(void *dummy)
323 {
324 	/* called at splsoftnet() */
325 	pppoe_input();
326 }
327 #else
328 void pppoe_softintr_handler(void *dummy)
329 {
330 	int s = splnet();
331 	pppoe_input();
332 	callout_deactivate(&pppoe_softintr);
333 	splx(s);
334 }
335 #endif
336 
337 /* called at appropriate protection level */
338 static void
339 pppoe_input()
340 {
341 	struct mbuf *m;
342 	int s, disc_done, data_done;
343 
344 	do {
345 		disc_done = 0;
346 		data_done = 0;
347 		for (;;) {
348 			s = splnet();
349 			IF_DEQUEUE(&ppoediscinq, m);
350 			splx(s);
351 			if (m == NULL) break;
352 			disc_done = 1;
353 			pppoe_disc_input(m);
354 		}
355 
356 		for (;;) {
357 			s = splnet();
358 			IF_DEQUEUE(&ppoeinq, m);
359 			splx(s);
360 			if (m == NULL) break;
361 			data_done = 1;
362 			pppoe_data_input(m);
363 		}
364 	} while (disc_done || data_done);
365 }
366 
367 /* analyze and handle a single received packet while not in session state */
368 static void pppoe_dispatch_disc_pkt(u_int8_t *p, size_t size, struct ifnet *rcvif, struct ether_header *eh)
369 {
370 	u_int16_t tag, len;
371 	u_int8_t vertype, code;
372 	u_int16_t session, plen;
373 	struct pppoe_softc *sc;
374 	const char *err_msg = NULL;
375 	u_int8_t * ac_cookie;
376 	size_t ac_cookie_len;
377 
378 	ac_cookie = NULL;
379 	ac_cookie_len = 0;
380 	session = 0;
381 	if (size <= PPPOE_HEADERLEN) {
382 		printf("pppoe: packet too short: %ld\n", (long)size);
383 		return;
384 	}
385 	vertype = *p++;
386 	if (vertype != PPPOE_VERTYPE) {
387 		printf("pppoe: unknown version/type packet: 0x%x\n", vertype);
388 		return;
389 	}
390 	code = *p++;
391 	PPPOE_READ_16(p, session);
392 	PPPOE_READ_16(p, plen);
393 	size -= PPPOE_HEADERLEN;
394 
395 	if (plen > size) {
396 		printf("pppoe: packet content does not fit: data available = %ld, packet size = %ld\n",
397 			(long)size, (long)plen);
398 		return;
399 	}
400 	size = plen;	/* ignore trailing garbage */
401 	tag = 0;
402 	len = 0;
403 	sc = NULL;
404 	while (size > 4) {
405 		PPPOE_READ_16(p, tag);
406 		PPPOE_READ_16(p, len);
407 		if (len > size) {
408 			printf("pppoe: tag 0x%x len 0x%x is too long\n", tag, len);
409 			return;
410 		}
411 		switch (tag) {
412 		case PPPOE_TAG_EOL:
413 			size = 0; break;
414 		case PPPOE_TAG_SNAME:
415 			break;	/* ignored */
416 		case PPPOE_TAG_ACNAME:
417 			break;	/* ignored */
418 		case PPPOE_TAG_HUNIQUE:
419 			if (sc == NULL)
420 				sc = pppoe_find_softc_by_hunique(p, len, rcvif);
421 			break;
422 		case PPPOE_TAG_ACCOOKIE:
423 			if (ac_cookie == NULL) {
424 				ac_cookie = p;
425 				ac_cookie_len = len;
426 			}
427 			break;
428 		case PPPOE_TAG_SNAME_ERR:
429 			err_msg = "SERVICE NAME ERROR";
430 			break;
431 		case PPPOE_TAG_ACSYS_ERR:
432 			err_msg = "AC SYSTEM ERROR";
433 			break;
434 		case PPPOE_TAG_GENERIC_ERR:
435 			err_msg = "GENERIC ERROR";
436 			break;
437 		}
438 		if (err_msg) {
439 			printf("%s: %s\n", sc? sc->sc_sppp.pp_if.if_xname : "pppoe",
440 					err_msg);
441 			return;
442 		}
443 		if (size >= 0) {
444 			size -= 4 + len;
445 			if (len > 0)
446 				p += len;
447 		}
448 	}
449 	switch (code) {
450 	case PPPOE_CODE_PADI:
451 	case PPPOE_CODE_PADR:
452 		/* ignore, we are no access concentrator */
453 		return;
454 	case PPPOE_CODE_PADO:
455 		if (sc == NULL) {
456 			/* be quiete if there is not a single pppoe instance */
457 			if (!LIST_EMPTY(&pppoe_softc_list))
458 				printf("pppoe: received PADO but could not find request for it\n");
459 			return;
460 		}
461 		if (sc->sc_state != PPPOE_STATE_PADI_SENT) {
462 			printf("%s: received unexpected PADO\n", sc->sc_sppp.pp_if.if_xname);
463 			return;
464 		}
465 		if (ac_cookie) {
466 			sc->sc_ac_cookie = malloc(ac_cookie_len, M_DEVBUF, M_DONTWAIT);
467 			if (sc->sc_ac_cookie == NULL)
468 				return;
469 			sc->sc_ac_cookie_len = ac_cookie_len;
470 			memcpy(sc->sc_ac_cookie, ac_cookie, ac_cookie_len);
471 		}
472 		memcpy(&sc->sc_dest, eh->ether_shost, sizeof sc->sc_dest);
473 		callout_stop(&sc->sc_timeout);
474 		sc->sc_padr_retried = 0;
475 		sc->sc_state = PPPOE_STATE_PADR_SENT;
476 		if (pppoe_send_padr(sc) == 0)
477 			callout_reset(&sc->sc_timeout, PPPOE_DISC_TIMEOUT*(1+sc->sc_padr_retried), pppoe_timeout, sc);
478 		else
479 			pppoe_abort_connect(sc);
480 		break;
481 	case PPPOE_CODE_PADS:
482 		if (sc == NULL)
483 			return;
484 		sc->sc_session = session;
485 		callout_stop(&sc->sc_timeout);
486 		if (sc->sc_sppp.pp_if.if_flags & IFF_DEBUG)
487 			printf("%s: session 0x%x connected\n", sc->sc_sppp.pp_if.if_xname, session);
488 		sc->sc_state = PPPOE_STATE_SESSION;
489 		sc->sc_sppp.pp_up(&sc->sc_sppp);	/* notify upper layers */
490 		break;
491 	case PPPOE_CODE_PADT:
492 		if (sc == NULL)
493 			return;
494                 /* stop timer (we might be about to transmit a PADT ourself) */
495                 callout_stop(&sc->sc_timeout);
496                 if (sc->sc_sppp.pp_if.if_flags & IFF_DEBUG)
497 	                printf("%s: session 0x%x terminated, received PADT\n", sc->sc_sppp.pp_if.if_xname, session);
498                 /* clean up softc */
499                 sc->sc_state = PPPOE_STATE_INITIAL;
500                 memcpy(&sc->sc_dest, etherbroadcastaddr, sizeof(sc->sc_dest));
501                 if (sc->sc_ac_cookie) {
502                         free(sc->sc_ac_cookie, M_MBUF);
503                         sc->sc_ac_cookie = NULL;
504                 }
505                 sc->sc_ac_cookie_len = 0;
506                 sc->sc_session = 0;
507                 /* signal upper layer */
508                 sc->sc_sppp.pp_down(&sc->sc_sppp);
509                 break;
510         default:
511                 printf("%s: unknown code (0x%04x) session = 0x%04x\n",
512                     sc? sc->sc_sppp.pp_if.if_xname : "pppoe",
513                     code, session);
514                 break;
515         }
516 }
517 
518 static void
519 pppoe_disc_input(struct mbuf *m)
520 {
521         u_int8_t *p;
522         struct ether_header *eh;
523 
524         /* avoid error messages if there is not a single pppoe instance */
525         if (!LIST_EMPTY(&pppoe_softc_list)) {
526 	        eh = mtod(m, struct ether_header*);
527         	m_adj(m, sizeof(struct ether_header));
528 	        p = mtod(m, u_int8_t*);
529         	KASSERT(m->m_flags & M_PKTHDR);
530 	        pppoe_dispatch_disc_pkt(p, m->m_len, m->m_pkthdr.rcvif, eh);
531 	}
532         m_free(m);
533 }
534 
535 static void
536 pppoe_data_input(struct mbuf *m)
537 {
538         u_int8_t *p, vertype;
539         u_int16_t session, plen, code;
540         struct pppoe_softc *sc;
541 
542         KASSERT(m->m_flags & M_PKTHDR);
543 
544         m_adj(m, sizeof(struct ether_header));
545         if (m->m_pkthdr.len <= PPPOE_HEADERLEN) {
546                 printf("pppoe (data): dropping too short packet: %ld bytes\n", (long)m->m_pkthdr.len);
547                 goto drop;
548         }
549 
550         p = mtod(m, u_int8_t*);
551 
552         vertype = *p++;
553         if (vertype != PPPOE_VERTYPE) {
554                 printf("pppoe (data): unknown version/type packet: 0x%x\n", vertype);
555                 goto drop;
556         }
557 
558         code = *p++;
559         if (code != 0)
560                 goto drop;
561 
562         PPPOE_READ_16(p, session);
563         sc = pppoe_find_softc_by_session(session, m->m_pkthdr.rcvif);
564         if (sc == NULL)
565                 goto drop;
566 
567         PPPOE_READ_16(p, plen);
568 
569 #if NBPFILTER > 0
570         if(sc->sc_sppp.pp_if.if_bpf)
571                 bpf_mtap(sc->sc_sppp.pp_if.if_bpf, m);
572 #endif
573 
574         m_adj(m, PPPOE_HEADERLEN);
575 
576 #ifdef PPPOE_DEBUG
577         {
578                 struct mbuf *p;
579 
580                 printf("%s: pkthdr.len=%d, pppoe.len=%d",
581                         sc->sc_sppp.pp_if.if_xname,
582                         m->m_pkthdr.len, plen);
583                 p = m;
584                 while (p) {
585                         printf(" l=%d", p->m_len);
586                         p = p->m_next;
587                 }
588                 printf("\n");
589         }
590 #endif
591 
592         if (m->m_pkthdr.len < plen)
593                 goto drop;
594 
595         /* fix incoming interface pointer (not the raw ethernet interface anymore) */
596         m->m_pkthdr.rcvif = &sc->sc_sppp.pp_if;
597 
598         /* pass packet up and account for it */
599         sc->sc_sppp.pp_if.if_ipackets++;
600         sppp_input(&sc->sc_sppp.pp_if, m);
601         return;
602 
603 drop:
604         m_free(m);
605 }
606 
607 static int
608 pppoe_output(struct pppoe_softc *sc, struct mbuf *m)
609 {
610         struct sockaddr dst;
611         struct ether_header *eh;
612         u_int16_t etype;
613 
614         if (sc->sc_eth_if == NULL)
615                 return EIO;
616 
617         memset(&dst, 0, sizeof dst);
618         dst.sa_family = AF_UNSPEC;
619         eh = (struct ether_header*)&dst.sa_data;
620         etype = sc->sc_state == PPPOE_STATE_SESSION? ETHERTYPE_PPPOE : ETHERTYPE_PPPOEDISC;
621         eh->ether_type = htons(etype);
622         memcpy(&eh->ether_dhost, &sc->sc_dest, sizeof sc->sc_dest);
623 
624 #ifdef PPPOE_DEBUG
625         printf("%s (%x) state=%d, session=0x%x output -> %s, len=%d\n",
626             sc->sc_sppp.pp_if.if_xname, etype,
627             sc->sc_state, sc->sc_session,
628 	    ether_sprintf((const unsigned char *)&sc->sc_dest), m->m_pkthdr.len);
629 #endif
630 
631 	m->m_flags &= ~(M_BCAST|M_MCAST);
632 	sc->sc_sppp.pp_if.if_opackets++;
633 	return sc->sc_eth_if->if_output(sc->sc_eth_if, m, &dst, NULL);
634 }
635 
636 static int
637 pppoe_ioctl(struct ifnet *ifp, unsigned long cmd, caddr_t data)
638 {
639 	struct proc *p = curproc;	/* XXX */
640 	struct pppoe_softc *sc = (struct pppoe_softc*)ifp;
641 	int error = 0;
642 
643 	switch (cmd) {
644 	case PPPOESETPARMS:
645 	{
646 		struct pppoediscparms *parms = (struct pppoediscparms*)data;
647 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
648 			return error;
649 		if (parms->eth_ifname[0] != 0) {
650 			sc->sc_eth_if = ifunit(parms->eth_ifname);
651 			if (sc->sc_eth_if == NULL)
652 				return ENXIO;
653 		}
654 		if (parms->ac_name) {
655 			size_t s;
656 			char * p = malloc(parms->ac_name_len + 1, M_DEVBUF, M_WAITOK);
657 			copyinstr(parms->ac_name, p, parms->ac_name_len, &s);
658 			if (sc->sc_concentrator_name)
659 				free(sc->sc_concentrator_name, M_DEVBUF);
660 			sc->sc_concentrator_name = p;
661 		}
662 		if (parms->service_name) {
663 			size_t s;
664 			char * p = malloc(parms->service_name_len + 1, M_DEVBUF, M_WAITOK);
665 			copyinstr(parms->service_name, p, parms->service_name_len, &s);
666 			if (sc->sc_service_name)
667 				free(sc->sc_service_name, M_DEVBUF);
668 			sc->sc_service_name = p;
669 		}
670 		return 0;
671 	}
672 	break;
673 	case PPPOEGETPARMS:
674 	{
675 		struct pppoediscparms *parms = (struct pppoediscparms*)data;
676 		memset(parms, 0, sizeof *parms);
677 		if (sc->sc_eth_if)
678 			strncpy(parms->ifname, sc->sc_eth_if->if_xname, IFNAMSIZ);
679 		return 0;
680 	}
681 	break;
682 	case PPPOEGETSESSION:
683 	{
684 		struct pppoeconnectionstate *state = (struct pppoeconnectionstate*)data;
685 		state->state = sc->sc_state;
686 		state->session_id = sc->sc_session;
687 		state->padi_retry_no = sc->sc_padi_retried;
688 		state->padr_retry_no = sc->sc_padr_retried;
689 		return 0;
690 	}
691 	break;
692 	case SIOCSIFFLAGS:
693 	{
694 		struct ifreq *ifr = (struct ifreq*) data;
695 		/*
696 		 * Prevent running re-establishment timers overriding
697 		 * administrators choice.
698 		 */
699 		if ((ifr->ifr_flags & IFF_UP) == 0
700 		     && sc->sc_state >= PPPOE_STATE_PADI_SENT
701 		     && sc->sc_state < PPPOE_STATE_SESSION) {
702 			callout_stop(&sc->sc_timeout);
703 			sc->sc_state = PPPOE_STATE_INITIAL;
704 			sc->sc_padi_retried = 0;
705 			sc->sc_padr_retried = 0;
706 			memcpy(&sc->sc_dest, etherbroadcastaddr, sizeof(sc->sc_dest));
707 		}
708 		return sppp_ioctl(ifp, cmd, data);
709 	}
710 	case SIOCSIFMTU:
711 	{
712 		struct ifreq *ifr = (struct ifreq*) data;
713 
714 		if (ifr->ifr_mtu > PPPOE_MAXMTU)
715 			return EINVAL;
716 		return sppp_ioctl(ifp, cmd, data);
717 	}
718 	default:
719 		return sppp_ioctl(ifp, cmd, data);
720 	}
721 	return 0;
722 }
723 
724 /*
725  * Allocate a mbuf/cluster with space to store the given data length
726  * of payload, leaving space for prepending an ethernet header
727  * in front.
728  */
729 static struct mbuf *
730 pppoe_get_mbuf(size_t len)
731 {
732 	struct mbuf *m;
733 
734 	MGETHDR(m, M_DONTWAIT, MT_DATA);
735 	if (m == NULL)
736 		return NULL;
737 	if (len+sizeof(struct ether_header) > MHLEN) {
738 		MCLGET(m, M_DONTWAIT);
739 		if ((m->m_flags & M_EXT) == 0) {
740 			struct mbuf *n;
741 			MFREE(m, n);
742 			return 0;
743 		}
744 	}
745 	m->m_data += sizeof(struct ether_header);
746 	m->m_len = len;
747 	m->m_pkthdr.len = len;
748 	m->m_pkthdr.rcvif = NULL;
749 
750 	return m;
751 }
752 
753 static int
754 pppoe_send_padi(struct pppoe_softc *sc)
755 {
756 	struct mbuf *m0;
757 	int len, l1, l2;
758 	u_int8_t *p;
759 
760 	if (sc->sc_state >PPPOE_STATE_PADI_SENT)
761 		panic("pppoe_send_padi in state %d", sc->sc_state);
762 
763 	/* calculate length of frame (excluding ethernet header + pppoe header) */
764 	len = 2+2+2+2+sizeof sc;	/* service name tag is required, host unique is send too */
765 	if (sc->sc_service_name != NULL) {
766 		l1 = strlen(sc->sc_service_name);
767 		len += l1;
768 	}
769 	if (sc->sc_concentrator_name != NULL) {
770 		l2 = strlen(sc->sc_concentrator_name);
771 		len += 2+2+l2;
772 	}
773 
774 	/* allocate a buffer */
775 	m0 = pppoe_get_mbuf(len+PPPOE_HEADERLEN);	/* header len + payload len */
776 	if (!m0) return ENOBUFS;
777 
778 	/* fill in pkt */
779 	p = mtod(m0, u_int8_t*);
780 	PPPOE_ADD_HEADER(p, PPPOE_CODE_PADI, 0, len);
781 	PPPOE_ADD_16(p, PPPOE_TAG_SNAME);
782 	if (sc->sc_service_name != NULL) {
783 		PPPOE_ADD_16(p, l1);
784 		memcpy(p, sc->sc_service_name, l1);
785 		p += l1;
786 	} else {
787 		PPPOE_ADD_16(p, 0);
788 	}
789 	if (sc->sc_concentrator_name != NULL) {
790 		PPPOE_ADD_16(p, PPPOE_TAG_ACNAME);
791 		PPPOE_ADD_16(p, l2);
792 		memcpy(p, sc->sc_concentrator_name, l2);
793 		p += l2;
794 	}
795 	PPPOE_ADD_16(p, PPPOE_TAG_HUNIQUE);
796 	PPPOE_ADD_16(p, sizeof(sc));
797 	memcpy(p, &sc, sizeof sc);
798 
799 #ifdef PPPOE_DEBUG
800 	p += sizeof sc;
801 	if (p - mtod(m0, u_int8_t*) != len + PPPOE_HEADERLEN)
802 		panic("pppoe_send_padi: garbled output len, should be %ld, is %ld",
803 		    (long)(len + PPPOE_HEADERLEN), (long)(p - mtod(m0, u_int8_t*)));
804 #endif
805 
806 	/* send pkt */
807 	return pppoe_output(sc, m0);
808 }
809 
810 static void
811 pppoe_timeout(void *arg)
812 {
813 	int x, retry_wait;
814 	struct pppoe_softc *sc = (struct pppoe_softc*)arg;
815 
816 #ifdef PPPOE_DEBUG
817 	printf("%s: timeout\n", sc->sc_sppp.pp_if.if_xname);
818 #endif
819 
820 	switch (sc->sc_state) {
821 	case PPPOE_STATE_PADI_SENT:
822 		/*
823 		 * We have two basic ways of retrying:
824 		 *  - Quick retry mode: try a few times in short sequence
825 		 *  - Slow retry mode: we already had a connection successfully
826 		 *    established and will try infinitely (without user
827 		 *    intervention)
828 		 * We only enter slow retry mode if IFF_LINK1 (aka autodial)
829 		 * is not set and we already had a successfull connection.
830 		 */
831 
832 		/* initialize for quick retry mode */
833 		retry_wait = PPPOE_DISC_TIMEOUT*(1+sc->sc_padi_retried);
834 
835 		x = splnet();
836 		sc->sc_padi_retried++;
837 		if (sc->sc_padi_retried >= PPPOE_DISC_MAXPADI) {
838 			if ((sc->sc_sppp.pp_if.if_flags & IFF_LINK1) == 0
839 			   && sc->sc_sppp.pp_if.if_ibytes) {
840 			    /* slow retry mode */
841 			    retry_wait = PPPOE_SLOW_RETRY;
842 			} else {
843 			    pppoe_abort_connect(sc);
844 			    splx(x);
845 			    return;
846 			}
847 		}
848 		if (pppoe_send_padi(sc) == 0)
849 			callout_reset(&sc->sc_timeout, retry_wait, pppoe_timeout, sc);
850 		else
851 			pppoe_abort_connect(sc);
852 		splx(x);
853 		break;
854 
855 	case PPPOE_STATE_PADR_SENT:
856 		x = splnet();
857 		sc->sc_padr_retried++;
858 		if (sc->sc_padr_retried >= PPPOE_DISC_MAXPADR) {
859 			memcpy(&sc->sc_dest, etherbroadcastaddr, sizeof(sc->sc_dest));
860 			sc->sc_state = PPPOE_STATE_PADI_SENT;
861 			sc->sc_padr_retried = 0;
862 			if (pppoe_send_padi(sc) == 0)
863 				callout_reset(&sc->sc_timeout, PPPOE_DISC_TIMEOUT*(1+sc->sc_padi_retried), pppoe_timeout, sc);
864 			else
865 				pppoe_abort_connect(sc);
866 			splx(x);
867 			return;
868 		}
869 		if (pppoe_send_padr(sc) == 0)
870 			callout_reset(&sc->sc_timeout, PPPOE_DISC_TIMEOUT*(1+sc->sc_padr_retried), pppoe_timeout, sc);
871 		else
872 			pppoe_abort_connect(sc);
873 		splx(x);
874 		break;
875 	case PPPOE_STATE_CLOSING:
876 		pppoe_disconnect(sc);
877 		break;
878 	default:
879 		return;	/* all done, work in peace */
880 	}
881 }
882 
883 /* Start a connection (i.e. initiate discovery phase) */
884 static int
885 pppoe_connect(struct pppoe_softc *sc)
886 {
887 	int x, err;
888 
889 	if (sc->sc_state != PPPOE_STATE_INITIAL)
890 		return EBUSY;
891 
892 	x = splnet();
893 	sc->sc_state = PPPOE_STATE_PADI_SENT;
894 	sc->sc_padr_retried = 0;
895 	err = pppoe_send_padi(sc);
896 	if (err == 0)
897 		callout_reset(&sc->sc_timeout, PPPOE_DISC_TIMEOUT, pppoe_timeout, sc);
898 	else
899 		pppoe_abort_connect(sc);
900 	splx(x);
901 	return err;
902 }
903 
904 /* disconnect */
905 static int
906 pppoe_disconnect(struct pppoe_softc *sc)
907 {
908 	int err, x;
909 
910 	x = splnet();
911 
912 	if (sc->sc_state < PPPOE_STATE_SESSION)
913 		err = EBUSY;
914 	else {
915 		if (sc->sc_sppp.pp_if.if_flags & IFF_DEBUG)
916 			printf("%s: disconnecting\n", sc->sc_sppp.pp_if.if_xname);
917 		err = pppoe_send_padt(sc);
918 	}
919 
920 	/* cleanup softc */
921 	sc->sc_state = PPPOE_STATE_INITIAL;
922 	memcpy(&sc->sc_dest, etherbroadcastaddr, sizeof(sc->sc_dest));
923 	if (sc->sc_ac_cookie) {
924 		free(sc->sc_ac_cookie, M_MBUF);
925 		sc->sc_ac_cookie = NULL;
926 	}
927 	sc->sc_ac_cookie_len = 0;
928 	sc->sc_session = 0;
929 
930 	/* notify upper layer */
931 	sc->sc_sppp.pp_down(&sc->sc_sppp);
932 
933 	splx(x);
934 
935 	return err;
936 }
937 
938 /* Connection attempt aborted */
939 static void
940 pppoe_abort_connect(struct pppoe_softc *sc)
941 {
942 	printf("%s: could not establish connection\n",
943 		sc->sc_sppp.pp_if.if_xname);
944 	sc->sc_state = PPPOE_STATE_INITIAL;
945 	memcpy(&sc->sc_dest, etherbroadcastaddr, sizeof(sc->sc_dest));
946 
947 	/* notify upper layer */
948 	sc->sc_sppp.pp_down(&sc->sc_sppp);
949 }
950 
951 /* Send a PADR packet */
952 static int
953 pppoe_send_padr(struct pppoe_softc *sc)
954 {
955 	struct mbuf *m0;
956 	u_int8_t *p;
957 	size_t len, l1;
958 
959 	if (sc->sc_state != PPPOE_STATE_PADR_SENT)
960 		return EIO;
961 
962 	len = 2+2+2+2+sizeof(sc);			/* service name, host unique */
963 	if (sc->sc_service_name != NULL) {		/* service name tag maybe empty */
964 		l1 = strlen(sc->sc_service_name);
965 		len += l1;
966 	}
967 	if (sc->sc_ac_cookie_len > 0)
968 		len += 2+2+sc->sc_ac_cookie_len;	/* AC cookie */
969 	m0 = pppoe_get_mbuf(len+PPPOE_HEADERLEN);
970 	if (!m0) return ENOBUFS;
971 	p = mtod(m0, u_int8_t*);
972 	PPPOE_ADD_HEADER(p, PPPOE_CODE_PADR, 0, len);
973 	PPPOE_ADD_16(p, PPPOE_TAG_SNAME);
974 	if (sc->sc_service_name != NULL) {
975 		PPPOE_ADD_16(p, l1);
976 		memcpy(p, sc->sc_service_name, l1);
977 		p += l1;
978 	} else {
979 		PPPOE_ADD_16(p, 0);
980 	}
981 	if (sc->sc_ac_cookie_len > 0) {
982 		PPPOE_ADD_16(p, PPPOE_TAG_ACCOOKIE);
983 		PPPOE_ADD_16(p, sc->sc_ac_cookie_len);
984 		memcpy(p, sc->sc_ac_cookie, sc->sc_ac_cookie_len);
985 		p += sc->sc_ac_cookie_len;
986 	}
987 	PPPOE_ADD_16(p, PPPOE_TAG_HUNIQUE);
988 	PPPOE_ADD_16(p, sizeof(sc));
989 	memcpy(p, &sc, sizeof sc);
990 
991 #ifdef PPPOE_DEBUG
992 	p += sizeof sc;
993 	if (p - mtod(m0, u_int8_t*) != len + PPPOE_HEADERLEN)
994 		panic("pppoe_send_padr: garbled output len, should be %ld, is %ld",
995 			(long)(len + PPPOE_HEADERLEN), (long)(p - mtod(m0, u_int8_t*)));
996 #endif
997 
998 	return pppoe_output(sc, m0);
999 }
1000 
1001 /* send a PADT packet */
1002 static int
1003 pppoe_send_padt(struct pppoe_softc *sc)
1004 {
1005 	struct mbuf *m0;
1006 	u_int8_t *p;
1007 
1008 	if (sc->sc_state < PPPOE_STATE_SESSION)
1009 		return EIO;
1010 
1011 #ifdef PPPOE_DEBUG
1012 	printf("%s: sending PADT\n", sc->sc_sppp.pp_if.if_xname);
1013 #endif
1014 	m0 = pppoe_get_mbuf(PPPOE_HEADERLEN);
1015 	if (!m0) return ENOBUFS;
1016 	p = mtod(m0, u_int8_t*);
1017 	PPPOE_ADD_HEADER(p, PPPOE_CODE_PADT, sc->sc_session, 0);
1018 	return pppoe_output(sc, m0);
1019 }
1020 
1021 static void
1022 pppoe_tls(struct sppp *sp)
1023 {
1024 	struct pppoe_softc *sc = (void*)sp;
1025 	if (sc->sc_state != PPPOE_STATE_INITIAL)
1026 		return;
1027 	pppoe_connect(sc);
1028 }
1029 
1030 static void
1031 pppoe_tlf(struct sppp *sp)
1032 {
1033 	struct pppoe_softc *sc = (void*)sp;
1034 	if (sc->sc_state < PPPOE_STATE_SESSION)
1035 		return;
1036 	/*
1037 	 * Do not call pppoe_disconnect here, the upper layer state
1038 	 * machine gets confused by this. We must return from this
1039 	 * function and defer disconnecting to the timeout handler.
1040 	 */
1041 	sc->sc_state = PPPOE_STATE_CLOSING;
1042 	callout_reset(&sc->sc_timeout, hz/50, pppoe_timeout, sc);
1043 }
1044 
1045 static void
1046 pppoe_start(struct ifnet *ifp)
1047 {
1048 	struct pppoe_softc *sc = (void*)ifp;
1049 	struct mbuf *m;
1050 	u_int8_t *p;
1051 	size_t len;
1052 
1053 	if (sppp_isempty(ifp))
1054 		return;
1055 
1056 	/* are we ready to proccess data yet? */
1057 	if (sc->sc_state < PPPOE_STATE_SESSION) {
1058 		sppp_flush(&sc->sc_sppp.pp_if);
1059 		return;
1060 	}
1061 
1062 	while ((m = sppp_dequeue(ifp)) != NULL) {
1063 		len = m->m_pkthdr.len;
1064 		M_PREPEND(m, PPPOE_HEADERLEN, M_DONTWAIT);
1065 		if (m == NULL) {
1066 			m_free(m);
1067 			break;
1068 		}
1069 		p = mtod(m, u_int8_t*);
1070 		PPPOE_ADD_HEADER(p, 0, sc->sc_session, len);
1071 
1072 #if NBPFILTER > 0
1073 		if(sc->sc_sppp.pp_if.if_bpf)
1074 			bpf_mtap(sc->sc_sppp.pp_if.if_bpf, m);
1075 #endif
1076 
1077 		pppoe_output(sc, m);
1078 	}
1079 }
1080