xref: /netbsd-src/sys/net/if_ppp.c (revision 7cc2f76925f078d01ddc9e640a98f4ccfc9f8c3b)
1 /*	$NetBSD: if_ppp.c,v 1.63 2000/12/12 18:00:27 thorpej Exp $	*/
2 /*	Id: if_ppp.c,v 1.6 1997/03/04 03:33:00 paulus Exp 	*/
3 
4 /*
5  * if_ppp.c - Point-to-Point Protocol (PPP) Asynchronous driver.
6  *
7  * Copyright (c) 1989 Carnegie Mellon University.
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms are permitted
11  * provided that the above copyright notice and this paragraph are
12  * duplicated in all such forms and that any documentation,
13  * advertising materials, and other materials related to such
14  * distribution and use acknowledge that the software was developed
15  * by Carnegie Mellon University.  The name of the
16  * University may not be used to endorse or promote products derived
17  * from this software without specific prior written permission.
18  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
20  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
21  *
22  * Drew D. Perkins
23  * Carnegie Mellon University
24  * 4910 Forbes Ave.
25  * Pittsburgh, PA 15213
26  * (412) 268-8576
27  * ddp@andrew.cmu.edu
28  *
29  * Based on:
30  *	@(#)if_sl.c	7.6.1.2 (Berkeley) 2/15/89
31  *
32  * Copyright (c) 1987 Regents of the University of California.
33  * All rights reserved.
34  *
35  * Redistribution and use in source and binary forms are permitted
36  * provided that the above copyright notice and this paragraph are
37  * duplicated in all such forms and that any documentation,
38  * advertising materials, and other materials related to such
39  * distribution and use acknowledge that the software was developed
40  * by the University of California, Berkeley.  The name of the
41  * University may not be used to endorse or promote products derived
42  * from this software without specific prior written permission.
43  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
44  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
45  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
46  *
47  * Serial Line interface
48  *
49  * Rick Adams
50  * Center for Seismic Studies
51  * 1300 N 17th Street, Suite 1450
52  * Arlington, Virginia 22209
53  * (703)276-7900
54  * rick@seismo.ARPA
55  * seismo!rick
56  *
57  * Pounded on heavily by Chris Torek (chris@mimsy.umd.edu, umcp-cs!chris).
58  * Converted to 4.3BSD Beta by Chris Torek.
59  * Other changes made at Berkeley, based in part on code by Kirk Smith.
60  *
61  * Converted to 4.3BSD+ 386BSD by Brad Parker (brad@cayman.com)
62  * Added VJ tcp header compression; more unified ioctls
63  *
64  * Extensively modified by Paul Mackerras (paulus@cs.anu.edu.au).
65  * Cleaned up a lot of the mbuf-related code to fix bugs that
66  * caused system crashes and packet corruption.  Changed pppstart
67  * so that it doesn't just give up with a collision if the whole
68  * packet doesn't fit in the output ring buffer.
69  *
70  * Added priority queueing for interactive IP packets, following
71  * the model of if_sl.c, plus hooks for bpf.
72  * Paul Mackerras (paulus@cs.anu.edu.au).
73  */
74 
75 /* from if_sl.c,v 1.11 84/10/04 12:54:47 rick Exp */
76 /* from NetBSD: if_ppp.c,v 1.15.2.2 1994/07/28 05:17:58 cgd Exp */
77 
78 #include "ppp.h"
79 
80 #if NPPP > 0
81 
82 #include "opt_inet.h"
83 #include "opt_gateway.h"
84 #include "opt_ppp.h"
85 
86 #ifdef INET
87 #define VJC
88 #endif
89 #define PPP_COMPRESS
90 
91 #include <sys/param.h>
92 #include <sys/proc.h>
93 #include <sys/mbuf.h>
94 #include <sys/socket.h>
95 #include <sys/ioctl.h>
96 #include <sys/kernel.h>
97 #include <sys/systm.h>
98 #include <sys/time.h>
99 #include <sys/malloc.h>
100 
101 #include <net/if.h>
102 #include <net/if_types.h>
103 #include <net/netisr.h>
104 #include <net/route.h>
105 #ifdef PPP_FILTER
106 #include <net/bpf.h>
107 #endif
108 
109 #include <netinet/in.h>
110 #include <netinet/in_systm.h>
111 #include <netinet/in_var.h>
112 #ifdef INET
113 #include <netinet/ip.h>
114 #endif
115 
116 #include "bpfilter.h"
117 #if NBPFILTER > 0
118 #include <sys/time.h>
119 #include <net/bpf.h>
120 #endif
121 
122 #if defined(PPP_FILTER) || NBPFILTER > 0
123 #include <net/slip.h>
124 #endif
125 
126 #ifdef VJC
127 #include <net/slcompress.h>
128 #endif
129 
130 #include <net/ppp_defs.h>
131 #include <net/if_ppp.h>
132 #include <net/if_pppvar.h>
133 #include <machine/cpu.h>
134 
135 #ifdef PPP_COMPRESS
136 #define PACKETPTR	struct mbuf *
137 #include <net/ppp-comp.h>
138 #endif
139 
140 static int	pppsioctl __P((struct ifnet *, u_long, caddr_t));
141 static void	ppp_requeue __P((struct ppp_softc *));
142 static void	ppp_ccp __P((struct ppp_softc *, struct mbuf *m, int rcvd));
143 static void	ppp_ccp_closed __P((struct ppp_softc *));
144 static void	ppp_inproc __P((struct ppp_softc *, struct mbuf *));
145 static void	pppdumpm __P((struct mbuf *m0));
146 
147 /*
148  * Some useful mbuf macros not in mbuf.h.
149  */
150 #define M_IS_CLUSTER(m)	((m)->m_flags & M_EXT)
151 
152 #define M_DATASTART(m)	\
153 	(M_IS_CLUSTER(m) ? (m)->m_ext.ext_buf : \
154 	    (m)->m_flags & M_PKTHDR ? (m)->m_pktdat : (m)->m_dat)
155 
156 #define M_DATASIZE(m)	\
157 	(M_IS_CLUSTER(m) ? (m)->m_ext.ext_size : \
158 	    (m)->m_flags & M_PKTHDR ? MHLEN: MLEN)
159 
160 /*
161  * We define two link layer specific mbuf flags, to mark high-priority
162  * packets for output, and received packets following lost/corrupted
163  * packets.
164  */
165 #define	M_HIGHPRI	M_LINK0	/* output packet for sc_fastq */
166 #define	M_ERRMARK	M_LINK1	/* rx packet following lost/corrupted pkt */
167 
168 #ifdef PPP_COMPRESS
169 /*
170  * List of compressors we know about.
171  * We leave some space so maybe we can modload compressors.
172  */
173 
174 extern struct compressor ppp_bsd_compress;
175 extern struct compressor ppp_deflate, ppp_deflate_draft;
176 
177 struct compressor *ppp_compressors[8] = {
178 #if DO_BSD_COMPRESS && defined(PPP_BSDCOMP)
179     &ppp_bsd_compress,
180 #endif
181 #if DO_DEFLATE && defined(PPP_DEFLATE)
182     &ppp_deflate,
183     &ppp_deflate_draft,
184 #endif
185     NULL
186 };
187 #endif /* PPP_COMPRESS */
188 
189 
190 /*
191  * Called from boot code to establish ppp interfaces.
192  */
193 void
194 pppattach()
195 {
196     struct ppp_softc *sc;
197     int i = 0;
198 
199     for (sc = ppp_softc; i < NPPP; sc++) {
200 	sc->sc_unit = i;	/* XXX */
201 	sprintf(sc->sc_if.if_xname, "ppp%d", i++);
202 	callout_init(&sc->sc_timo_ch);
203 	sc->sc_if.if_softc = sc;
204 	sc->sc_if.if_mtu = PPP_MTU;
205 	sc->sc_if.if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
206 	sc->sc_if.if_type = IFT_PPP;
207 	sc->sc_if.if_hdrlen = PPP_HDRLEN;
208 	sc->sc_if.if_ioctl = pppsioctl;
209 	sc->sc_if.if_output = pppoutput;
210 	sc->sc_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
211 	sc->sc_inq.ifq_maxlen = IFQ_MAXLEN;
212 	sc->sc_fastq.ifq_maxlen = IFQ_MAXLEN;
213 	sc->sc_rawq.ifq_maxlen = IFQ_MAXLEN;
214 	if_attach(&sc->sc_if);
215 #if NBPFILTER > 0
216 	bpfattach(&sc->sc_if, DLT_NULL, 0);
217 #endif
218     }
219 }
220 
221 /*
222  * Allocate a ppp interface unit and initialize it.
223  */
224 struct ppp_softc *
225 pppalloc(pid)
226     pid_t pid;
227 {
228     int nppp, i;
229     struct ppp_softc *sc;
230 
231     for (nppp = 0, sc = ppp_softc; nppp < NPPP; nppp++, sc++)
232 	if (sc->sc_xfer == pid) {
233 	    sc->sc_xfer = 0;
234 	    return sc;
235 	}
236     for (nppp = 0, sc = ppp_softc; nppp < NPPP; nppp++, sc++)
237 	if (sc->sc_devp == NULL)
238 	    break;
239     if (nppp >= NPPP)
240 	return NULL;
241 
242     sc->sc_flags = 0;
243     sc->sc_mru = PPP_MRU;
244     sc->sc_relinq = NULL;
245     bzero((char *)&sc->sc_stats, sizeof(sc->sc_stats));
246 #ifdef VJC
247     MALLOC(sc->sc_comp, struct slcompress *, sizeof(struct slcompress),
248 	   M_DEVBUF, M_NOWAIT);
249     if (sc->sc_comp)
250 	sl_compress_init(sc->sc_comp);
251 #endif
252 #ifdef PPP_COMPRESS
253     sc->sc_xc_state = NULL;
254     sc->sc_rc_state = NULL;
255 #endif /* PPP_COMPRESS */
256     for (i = 0; i < NUM_NP; ++i)
257 	sc->sc_npmode[i] = NPMODE_ERROR;
258     sc->sc_npqueue = NULL;
259     sc->sc_npqtail = &sc->sc_npqueue;
260     sc->sc_last_sent = sc->sc_last_recv = time.tv_sec;
261 
262     return sc;
263 }
264 
265 /*
266  * Deallocate a ppp unit.  Must be called at splsoftnet or higher.
267  */
268 void
269 pppdealloc(sc)
270     struct ppp_softc *sc;
271 {
272     struct mbuf *m;
273 
274     if_down(&sc->sc_if);
275     sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
276     sc->sc_devp = NULL;
277     sc->sc_xfer = 0;
278     for (;;) {
279 	IF_DEQUEUE(&sc->sc_rawq, m);
280 	if (m == NULL)
281 	    break;
282 	m_freem(m);
283     }
284     for (;;) {
285 	IF_DEQUEUE(&sc->sc_inq, m);
286 	if (m == NULL)
287 	    break;
288 	m_freem(m);
289     }
290     for (;;) {
291 	IF_DEQUEUE(&sc->sc_fastq, m);
292 	if (m == NULL)
293 	    break;
294 	m_freem(m);
295     }
296     while ((m = sc->sc_npqueue) != NULL) {
297 	sc->sc_npqueue = m->m_nextpkt;
298 	m_freem(m);
299     }
300     if (sc->sc_togo != NULL) {
301 	m_freem(sc->sc_togo);
302 	sc->sc_togo = NULL;
303     }
304 #ifdef PPP_COMPRESS
305     ppp_ccp_closed(sc);
306     sc->sc_xc_state = NULL;
307     sc->sc_rc_state = NULL;
308 #endif /* PPP_COMPRESS */
309 #ifdef PPP_FILTER
310     if (sc->sc_pass_filt_in.bf_insns != 0) {
311 	FREE(sc->sc_pass_filt_in.bf_insns, M_DEVBUF);
312 	sc->sc_pass_filt_in.bf_insns = 0;
313 	sc->sc_pass_filt_in.bf_len = 0;
314     }
315     if (sc->sc_pass_filt_out.bf_insns != 0) {
316 	FREE(sc->sc_pass_filt_out.bf_insns, M_DEVBUF);
317 	sc->sc_pass_filt_out.bf_insns = 0;
318 	sc->sc_pass_filt_out.bf_len = 0;
319     }
320     if (sc->sc_active_filt_in.bf_insns != 0) {
321 	FREE(sc->sc_active_filt_in.bf_insns, M_DEVBUF);
322 	sc->sc_active_filt_in.bf_insns = 0;
323 	sc->sc_active_filt_in.bf_len = 0;
324     }
325     if (sc->sc_active_filt_out.bf_insns != 0) {
326 	FREE(sc->sc_active_filt_out.bf_insns, M_DEVBUF);
327 	sc->sc_active_filt_out.bf_insns = 0;
328 	sc->sc_active_filt_out.bf_len = 0;
329     }
330 #endif /* PPP_FILTER */
331 #ifdef VJC
332     if (sc->sc_comp != 0) {
333 	FREE(sc->sc_comp, M_DEVBUF);
334 	sc->sc_comp = 0;
335     }
336 #endif
337 }
338 
339 /*
340  * Ioctl routine for generic ppp devices.
341  */
342 int
343 pppioctl(sc, cmd, data, flag, p)
344     struct ppp_softc *sc;
345     u_long cmd;
346     caddr_t data;
347     int flag;
348     struct proc *p;
349 {
350     int s, error, flags, mru, nb, npx;
351     struct ppp_option_data *odp;
352     struct compressor **cp;
353     struct npioctl *npi;
354     time_t t;
355 #ifdef PPP_FILTER
356     struct bpf_program *bp, *nbp;
357     struct bpf_insn *newcode, *oldcode;
358     int newcodelen;
359 #endif /* PPP_FILTER */
360 #ifdef	PPP_COMPRESS
361     u_char ccp_option[CCP_MAX_OPTION_LENGTH];
362 #endif
363 
364     switch (cmd) {
365     case FIONREAD:
366 	*(int *)data = sc->sc_inq.ifq_len;
367 	break;
368 
369     case PPPIOCGUNIT:
370 	*(int *)data = sc->sc_unit;	/* XXX */
371 	break;
372 
373     case PPPIOCGFLAGS:
374 	*(u_int *)data = sc->sc_flags;
375 	break;
376 
377     case PPPIOCSFLAGS:
378 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
379 	    return (error);
380 	flags = *(int *)data & SC_MASK;
381 	s = splsoftnet();
382 #ifdef PPP_COMPRESS
383 	if (sc->sc_flags & SC_CCP_OPEN && !(flags & SC_CCP_OPEN))
384 	    ppp_ccp_closed(sc);
385 #endif
386 	splimp();
387 	sc->sc_flags = (sc->sc_flags & ~SC_MASK) | flags;
388 	splx(s);
389 	break;
390 
391     case PPPIOCSMRU:
392 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
393 	    return (error);
394 	mru = *(int *)data;
395 	if (mru >= PPP_MINMRU && mru <= PPP_MAXMRU)
396 	    sc->sc_mru = mru;
397 	break;
398 
399     case PPPIOCGMRU:
400 	*(int *)data = sc->sc_mru;
401 	break;
402 
403 #ifdef VJC
404     case PPPIOCSMAXCID:
405 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
406 	    return (error);
407 	if (sc->sc_comp) {
408 	    s = splsoftnet();
409 	    sl_compress_setup(sc->sc_comp, *(int *)data);
410 	    splx(s);
411 	}
412 	break;
413 #endif
414 
415     case PPPIOCXFERUNIT:
416 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
417 	    return (error);
418 	sc->sc_xfer = p->p_pid;
419 	break;
420 
421 #ifdef PPP_COMPRESS
422     case PPPIOCSCOMPRESS:
423 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
424 	    return (error);
425 	odp = (struct ppp_option_data *) data;
426 	nb = odp->length;
427 	if (nb > sizeof(ccp_option))
428 	    nb = sizeof(ccp_option);
429 	if ((error = copyin(odp->ptr, ccp_option, nb)) != 0)
430 	    return (error);
431 	if (ccp_option[1] < 2)	/* preliminary check on the length byte */
432 	    return (EINVAL);
433 	for (cp = ppp_compressors; *cp != NULL; ++cp)
434 	    if ((*cp)->compress_proto == ccp_option[0]) {
435 		/*
436 		 * Found a handler for the protocol - try to allocate
437 		 * a compressor or decompressor.
438 		 */
439 		error = 0;
440 		if (odp->transmit) {
441 		    s = splsoftnet();
442 		    if (sc->sc_xc_state != NULL)
443 			(*sc->sc_xcomp->comp_free)(sc->sc_xc_state);
444 		    sc->sc_xcomp = *cp;
445 		    sc->sc_xc_state = (*cp)->comp_alloc(ccp_option, nb);
446 		    if (sc->sc_xc_state == NULL) {
447 			if (sc->sc_flags & SC_DEBUG)
448 			    printf("%s: comp_alloc failed\n",
449 				sc->sc_if.if_xname);
450 			error = ENOBUFS;
451 		    }
452 		    splimp();
453 		    sc->sc_flags &= ~SC_COMP_RUN;
454 		    splx(s);
455 		} else {
456 		    s = splsoftnet();
457 		    if (sc->sc_rc_state != NULL)
458 			(*sc->sc_rcomp->decomp_free)(sc->sc_rc_state);
459 		    sc->sc_rcomp = *cp;
460 		    sc->sc_rc_state = (*cp)->decomp_alloc(ccp_option, nb);
461 		    if (sc->sc_rc_state == NULL) {
462 			if (sc->sc_flags & SC_DEBUG)
463 			    printf("%s: decomp_alloc failed\n",
464 				sc->sc_if.if_xname);
465 			error = ENOBUFS;
466 		    }
467 		    splimp();
468 		    sc->sc_flags &= ~SC_DECOMP_RUN;
469 		    splx(s);
470 		}
471 		return (error);
472 	    }
473 	if (sc->sc_flags & SC_DEBUG)
474 	    printf("%s: no compressor for [%x %x %x], %x\n",
475 		sc->sc_if.if_xname, ccp_option[0], ccp_option[1],
476 		ccp_option[2], nb);
477 	return (EINVAL);	/* no handler found */
478 #endif /* PPP_COMPRESS */
479 
480     case PPPIOCGNPMODE:
481     case PPPIOCSNPMODE:
482 	npi = (struct npioctl *) data;
483 	switch (npi->protocol) {
484 	case PPP_IP:
485 	    npx = NP_IP;
486 	    break;
487 	case PPP_IPV6:
488 	    npx = NP_IPV6;
489 	    break;
490 	default:
491 	    return EINVAL;
492 	}
493 	if (cmd == PPPIOCGNPMODE) {
494 	    npi->mode = sc->sc_npmode[npx];
495 	} else {
496 	    if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
497 		return (error);
498 	    if (npi->mode != sc->sc_npmode[npx]) {
499 		s = splimp();
500 		sc->sc_npmode[npx] = npi->mode;
501 		if (npi->mode != NPMODE_QUEUE) {
502 		    ppp_requeue(sc);
503 		    ppp_restart(sc);
504 		}
505 		splx(s);
506 	    }
507 	}
508 	break;
509 
510     case PPPIOCGIDLE:
511 	s = splsoftnet();
512 	t = time.tv_sec;
513 	((struct ppp_idle *)data)->xmit_idle = t - sc->sc_last_sent;
514 	((struct ppp_idle *)data)->recv_idle = t - sc->sc_last_recv;
515 	splx(s);
516 	break;
517 
518 #ifdef PPP_FILTER
519     case PPPIOCSPASS:
520     case PPPIOCSACTIVE:
521 	/* These are no longer supported. */
522 	return EOPNOTSUPP;
523 
524     case PPPIOCSIPASS:
525     case PPPIOCSOPASS:
526     case PPPIOCSIACTIVE:
527     case PPPIOCSOACTIVE:
528 	nbp = (struct bpf_program *) data;
529 	if ((unsigned) nbp->bf_len > BPF_MAXINSNS)
530 	    return EINVAL;
531 	newcodelen = nbp->bf_len * sizeof(struct bpf_insn);
532 	if (newcodelen != 0) {
533 	    newcode = malloc(newcodelen, M_DEVBUF, M_WAITOK);
534 	    /* WAITOK -- malloc() never fails. */
535 	    if ((error = copyin((caddr_t)nbp->bf_insns, (caddr_t)newcode,
536 			       newcodelen)) != 0) {
537 		free(newcode, M_DEVBUF);
538 		return error;
539 	    }
540 	    if (!bpf_validate(newcode, nbp->bf_len)) {
541 		free(newcode, M_DEVBUF);
542 		return EINVAL;
543 	    }
544 	} else
545 	    newcode = 0;
546 	switch (cmd) {
547 	case PPPIOCSIPASS:
548 	    bp = &sc->sc_pass_filt_in;
549 	    break;
550 
551 	case PPPIOCSOPASS:
552 	    bp = &sc->sc_pass_filt_out;
553 	    break;
554 
555 	case PPPIOCSIACTIVE:
556 	    bp = &sc->sc_active_filt_in;
557 	    break;
558 
559 	case PPPIOCSOACTIVE:
560 	    bp = &sc->sc_active_filt_out;
561 	    break;
562 	}
563 	oldcode = bp->bf_insns;
564 	s = splimp();
565 	bp->bf_len = nbp->bf_len;
566 	bp->bf_insns = newcode;
567 	splx(s);
568 	if (oldcode != 0)
569 	    free(oldcode, M_DEVBUF);
570 	break;
571 #endif /* PPP_FILTER */
572 
573     default:
574 	return (-1);
575     }
576     return (0);
577 }
578 
579 /*
580  * Process an ioctl request to the ppp network interface.
581  */
582 static int
583 pppsioctl(ifp, cmd, data)
584     struct ifnet *ifp;
585     u_long cmd;
586     caddr_t data;
587 {
588     struct proc *p = curproc;	/* XXX */
589     struct ppp_softc *sc = ifp->if_softc;
590     struct ifaddr *ifa = (struct ifaddr *)data;
591     struct ifreq *ifr = (struct ifreq *)data;
592     struct ppp_stats *psp;
593 #ifdef	PPP_COMPRESS
594     struct ppp_comp_stats *pcp;
595 #endif
596     int s = splimp(), error = 0;
597 
598     switch (cmd) {
599     case SIOCSIFFLAGS:
600 	if ((ifp->if_flags & IFF_RUNNING) == 0)
601 	    ifp->if_flags &= ~IFF_UP;
602 	break;
603 
604     case SIOCSIFADDR:
605 	switch (ifa->ifa_addr->sa_family) {
606 #ifdef INET
607 	case AF_INET:
608 	    break;
609 #endif
610 #ifdef INET6
611 	case AF_INET6:
612 	    break;
613 #endif
614 	default:
615 	    error = EAFNOSUPPORT;
616 	    break;
617 	}
618 	break;
619 
620     case SIOCSIFDSTADDR:
621 	switch (ifa->ifa_addr->sa_family) {
622 #ifdef INET
623 	case AF_INET:
624 	    break;
625 #endif
626 #ifdef INET6
627 	case AF_INET6:
628 	    break;
629 #endif
630 	default:
631 	    error = EAFNOSUPPORT;
632 	    break;
633 	}
634 	break;
635 
636     case SIOCSIFMTU:
637 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
638 	    break;
639 	sc->sc_if.if_mtu = ifr->ifr_mtu;
640 	break;
641 
642     case SIOCGIFMTU:
643 	ifr->ifr_mtu = sc->sc_if.if_mtu;
644 	break;
645 
646     case SIOCADDMULTI:
647     case SIOCDELMULTI:
648 	if (ifr == 0) {
649 	    error = EAFNOSUPPORT;
650 	    break;
651 	}
652 	switch(ifr->ifr_addr.sa_family) {
653 #ifdef INET
654 	case AF_INET:
655 	    break;
656 #endif
657 #ifdef INET6
658 	case AF_INET6:
659 	    break;
660 #endif
661 	default:
662 	    error = EAFNOSUPPORT;
663 	    break;
664 	}
665 	break;
666 
667     case SIOCGPPPSTATS:
668 	psp = &((struct ifpppstatsreq *) data)->stats;
669 	bzero(psp, sizeof(*psp));
670 	psp->p = sc->sc_stats;
671 #if defined(VJC) && !defined(SL_NO_STATS)
672 	if (sc->sc_comp) {
673 	    psp->vj.vjs_packets = sc->sc_comp->sls_packets;
674 	    psp->vj.vjs_compressed = sc->sc_comp->sls_compressed;
675 	    psp->vj.vjs_searches = sc->sc_comp->sls_searches;
676 	    psp->vj.vjs_misses = sc->sc_comp->sls_misses;
677 	    psp->vj.vjs_uncompressedin = sc->sc_comp->sls_uncompressedin;
678 	    psp->vj.vjs_compressedin = sc->sc_comp->sls_compressedin;
679 	    psp->vj.vjs_errorin = sc->sc_comp->sls_errorin;
680 	    psp->vj.vjs_tossed = sc->sc_comp->sls_tossed;
681 	}
682 #endif /* VJC */
683 	break;
684 
685 #ifdef PPP_COMPRESS
686     case SIOCGPPPCSTATS:
687 	pcp = &((struct ifpppcstatsreq *) data)->stats;
688 	bzero(pcp, sizeof(*pcp));
689 	if (sc->sc_xc_state != NULL)
690 	    (*sc->sc_xcomp->comp_stat)(sc->sc_xc_state, &pcp->c);
691 	if (sc->sc_rc_state != NULL)
692 	    (*sc->sc_rcomp->decomp_stat)(sc->sc_rc_state, &pcp->d);
693 	break;
694 #endif /* PPP_COMPRESS */
695 
696     default:
697 	error = EINVAL;
698     }
699     splx(s);
700     return (error);
701 }
702 
703 /*
704  * Queue a packet.  Start transmission if not active.
705  * Packet is placed in Information field of PPP frame.
706  */
707 int
708 pppoutput(ifp, m0, dst, rtp)
709     struct ifnet *ifp;
710     struct mbuf *m0;
711     struct sockaddr *dst;
712     struct rtentry *rtp;
713 {
714     struct ppp_softc *sc = ifp->if_softc;
715     int protocol, address, control;
716     u_char *cp;
717     int s, error;
718 #ifdef INET
719     struct ip *ip;
720 #endif
721     struct ifqueue *ifq;
722     enum NPmode mode;
723     int len;
724     struct mbuf *m;
725 
726     if (sc->sc_devp == NULL || (ifp->if_flags & IFF_RUNNING) == 0
727 	|| ((ifp->if_flags & IFF_UP) == 0 && dst->sa_family != AF_UNSPEC)) {
728 	error = ENETDOWN;	/* sort of */
729 	goto bad;
730     }
731 
732     /*
733      * Compute PPP header.
734      */
735     m0->m_flags &= ~M_HIGHPRI;
736     switch (dst->sa_family) {
737 #ifdef INET
738     case AF_INET:
739 	address = PPP_ALLSTATIONS;
740 	control = PPP_UI;
741 	protocol = PPP_IP;
742 	mode = sc->sc_npmode[NP_IP];
743 
744 	/*
745 	 * If this packet has the "low delay" bit set in the IP header,
746 	 * put it on the fastq instead.
747 	 */
748 	ip = mtod(m0, struct ip *);
749 	if (ip->ip_tos & IPTOS_LOWDELAY)
750 	    m0->m_flags |= M_HIGHPRI;
751 	break;
752 #endif
753 #ifdef INET6
754     case AF_INET6:
755 	address = PPP_ALLSTATIONS;	/*XXX*/
756 	control = PPP_UI;		/*XXX*/
757 	protocol = PPP_IPV6;
758 	mode = sc->sc_npmode[NP_IPV6];
759 
760 #if 0	/* XXX flowinfo/traffic class, maybe? */
761 	/*
762 	 * If this packet has the "low delay" bit set in the IP header,
763 	 * put it on the fastq instead.
764 	 */
765 	ip = mtod(m0, struct ip *);
766 	if (ip->ip_tos & IPTOS_LOWDELAY)
767 	    m0->m_flags |= M_HIGHPRI;
768 #endif
769 	break;
770 #endif
771     case AF_UNSPEC:
772 	address = PPP_ADDRESS(dst->sa_data);
773 	control = PPP_CONTROL(dst->sa_data);
774 	protocol = PPP_PROTOCOL(dst->sa_data);
775 	mode = NPMODE_PASS;
776 	break;
777     default:
778 	printf("%s: af%d not supported\n", ifp->if_xname, dst->sa_family);
779 	error = EAFNOSUPPORT;
780 	goto bad;
781     }
782 
783     /*
784      * Drop this packet, or return an error, if necessary.
785      */
786     if (mode == NPMODE_ERROR) {
787 	error = ENETDOWN;
788 	goto bad;
789     }
790     if (mode == NPMODE_DROP) {
791 	error = 0;
792 	goto bad;
793     }
794 
795     /*
796      * Add PPP header.  If no space in first mbuf, allocate another.
797      * (This assumes M_LEADINGSPACE is always 0 for a cluster mbuf.)
798      */
799     if (M_LEADINGSPACE(m0) < PPP_HDRLEN) {
800 	m0 = m_prepend(m0, PPP_HDRLEN, M_DONTWAIT);
801 	if (m0 == 0) {
802 	    error = ENOBUFS;
803 	    goto bad;
804 	}
805 	m0->m_len = 0;
806     } else
807 	m0->m_data -= PPP_HDRLEN;
808 
809     cp = mtod(m0, u_char *);
810     *cp++ = address;
811     *cp++ = control;
812     *cp++ = protocol >> 8;
813     *cp++ = protocol & 0xff;
814     m0->m_len += PPP_HDRLEN;
815 
816     len = 0;
817     for (m = m0; m != 0; m = m->m_next)
818 	len += m->m_len;
819 
820     if (sc->sc_flags & SC_LOG_OUTPKT) {
821 	printf("%s output: ", ifp->if_xname);
822 	pppdumpm(m0);
823     }
824 
825     if ((protocol & 0x8000) == 0) {
826 #ifdef PPP_FILTER
827 	/*
828 	 * Apply the pass and active filters to the packet,
829 	 * but only if it is a data packet.
830 	 */
831 	if (sc->sc_pass_filt_out.bf_insns != 0
832 	    && bpf_filter(sc->sc_pass_filt_out.bf_insns, (u_char *) m0,
833 			  len, 0) == 0) {
834 	    error = 0;		/* drop this packet */
835 	    goto bad;
836 	}
837 
838 	/*
839 	 * Update the time we sent the most recent packet.
840 	 */
841 	if (sc->sc_active_filt_out.bf_insns == 0
842 	    || bpf_filter(sc->sc_active_filt_out.bf_insns, (u_char *) m0,
843 	    		  len, 0))
844 	    sc->sc_last_sent = time.tv_sec;
845 #else
846 	/*
847 	 * Update the time we sent the most recent packet.
848 	 */
849 	sc->sc_last_sent = time.tv_sec;
850 #endif /* PPP_FILTER */
851     }
852 
853 #if NBPFILTER > 0
854     /*
855      * See if bpf wants to look at the packet.
856      */
857     if (sc->sc_if.if_bpf)
858 	bpf_mtap(sc->sc_if.if_bpf, m0);
859 #endif
860 
861     /*
862      * Put the packet on the appropriate queue.
863      */
864     s = splimp();
865     if (mode == NPMODE_QUEUE) {
866 	/* XXX we should limit the number of packets on this queue */
867 	*sc->sc_npqtail = m0;
868 	m0->m_nextpkt = NULL;
869 	sc->sc_npqtail = &m0->m_nextpkt;
870     } else {
871 	ifq = (m0->m_flags & M_HIGHPRI)? &sc->sc_fastq: &ifp->if_snd;
872 	if (IF_QFULL(ifq) && dst->sa_family != AF_UNSPEC) {
873 	    IF_DROP(ifq);
874 	    splx(s);
875 	    sc->sc_if.if_oerrors++;
876 	    sc->sc_stats.ppp_oerrors++;
877 	    error = ENOBUFS;
878 	    goto bad;
879 	}
880 	IF_ENQUEUE(ifq, m0);
881 	ppp_restart(sc);
882     }
883     ifp->if_lastchange = time;
884     ifp->if_opackets++;
885     ifp->if_obytes += len;
886 
887     splx(s);
888     return (0);
889 
890 bad:
891     m_freem(m0);
892     return (error);
893 }
894 
895 /*
896  * After a change in the NPmode for some NP, move packets from the
897  * npqueue to the send queue or the fast queue as appropriate.
898  * Should be called at splimp, since we muck with the queues.
899  */
900 static void
901 ppp_requeue(sc)
902     struct ppp_softc *sc;
903 {
904     struct mbuf *m, **mpp;
905     struct ifqueue *ifq;
906     enum NPmode mode;
907 
908     for (mpp = &sc->sc_npqueue; (m = *mpp) != NULL; ) {
909 	switch (PPP_PROTOCOL(mtod(m, u_char *))) {
910 	case PPP_IP:
911 	    mode = sc->sc_npmode[NP_IP];
912 	    break;
913 	case PPP_IPV6:
914 	    mode = sc->sc_npmode[NP_IPV6];
915 	    break;
916 	default:
917 	    mode = NPMODE_PASS;
918 	}
919 
920 	switch (mode) {
921 	case NPMODE_PASS:
922 	    /*
923 	     * This packet can now go on one of the queues to be sent.
924 	     */
925 	    *mpp = m->m_nextpkt;
926 	    m->m_nextpkt = NULL;
927 	    ifq = (m->m_flags & M_HIGHPRI)? &sc->sc_fastq: &sc->sc_if.if_snd;
928 	    if (IF_QFULL(ifq)) {
929 		IF_DROP(ifq);
930 		sc->sc_if.if_oerrors++;
931 		sc->sc_stats.ppp_oerrors++;
932 	    } else
933 		IF_ENQUEUE(ifq, m);
934 	    break;
935 
936 	case NPMODE_DROP:
937 	case NPMODE_ERROR:
938 	    *mpp = m->m_nextpkt;
939 	    m_freem(m);
940 	    break;
941 
942 	case NPMODE_QUEUE:
943 	    mpp = &m->m_nextpkt;
944 	    break;
945 	}
946     }
947     sc->sc_npqtail = mpp;
948 }
949 
950 /*
951  * Transmitter has finished outputting some stuff;
952  * remember to call sc->sc_start later at splsoftnet.
953  */
954 void
955 ppp_restart(sc)
956     struct ppp_softc *sc;
957 {
958     int s = splimp();
959 
960     sc->sc_flags &= ~SC_TBUSY;
961     schednetisr(NETISR_PPP);
962     splx(s);
963 }
964 
965 /*
966  * Get a packet to send.  This procedure is intended to be called at
967  * splsoftnet, since it may involve time-consuming operations such as
968  * applying VJ compression, packet compression, address/control and/or
969  * protocol field compression to the packet.
970  */
971 struct mbuf *
972 ppp_dequeue(sc)
973     struct ppp_softc *sc;
974 {
975     struct mbuf *m, *mp;
976     u_char *cp;
977     int address, control, protocol;
978     int s;
979 
980     /*
981      * Grab a packet to send: first try the fast queue, then the
982      * normal queue.
983      */
984     s = splimp();
985     IF_DEQUEUE(&sc->sc_fastq, m);
986     if (m == NULL)
987 	IF_DEQUEUE(&sc->sc_if.if_snd, m);
988     splx(s);
989 
990     if (m == NULL)
991 	return NULL;
992 
993     ++sc->sc_stats.ppp_opackets;
994 
995     /*
996      * Extract the ppp header of the new packet.
997      * The ppp header will be in one mbuf.
998      */
999     cp = mtod(m, u_char *);
1000     address = PPP_ADDRESS(cp);
1001     control = PPP_CONTROL(cp);
1002     protocol = PPP_PROTOCOL(cp);
1003 
1004     switch (protocol) {
1005     case PPP_IP:
1006 #ifdef VJC
1007 	/*
1008 	 * If the packet is a TCP/IP packet, see if we can compress it.
1009 	 */
1010 	if ((sc->sc_flags & SC_COMP_TCP) && sc->sc_comp != NULL) {
1011 	    struct ip *ip;
1012 	    int type;
1013 
1014 	    mp = m;
1015 	    ip = (struct ip *) (cp + PPP_HDRLEN);
1016 	    if (mp->m_len <= PPP_HDRLEN) {
1017 		mp = mp->m_next;
1018 		if (mp == NULL)
1019 		    break;
1020 		ip = mtod(mp, struct ip *);
1021 	    }
1022 	    /* this code assumes the IP/TCP header is in one non-shared mbuf */
1023 	    if (ip->ip_p == IPPROTO_TCP) {
1024 		type = sl_compress_tcp(mp, ip, sc->sc_comp,
1025 				       !(sc->sc_flags & SC_NO_TCP_CCID));
1026 		switch (type) {
1027 		case TYPE_UNCOMPRESSED_TCP:
1028 		    protocol = PPP_VJC_UNCOMP;
1029 		    break;
1030 		case TYPE_COMPRESSED_TCP:
1031 		    protocol = PPP_VJC_COMP;
1032 		    cp = mtod(m, u_char *);
1033 		    cp[0] = address;	/* header has moved */
1034 		    cp[1] = control;
1035 		    cp[2] = 0;
1036 		    break;
1037 		}
1038 		cp[3] = protocol;	/* update protocol in PPP header */
1039 	    }
1040 	}
1041 #endif	/* VJC */
1042 	break;
1043 
1044 #ifdef PPP_COMPRESS
1045     case PPP_CCP:
1046 	ppp_ccp(sc, m, 0);
1047 	break;
1048 #endif	/* PPP_COMPRESS */
1049     }
1050 
1051 #ifdef PPP_COMPRESS
1052     if (protocol != PPP_LCP && protocol != PPP_CCP
1053 	&& sc->sc_xc_state && (sc->sc_flags & SC_COMP_RUN)) {
1054 	struct mbuf *mcomp = NULL;
1055 	int slen, clen;
1056 
1057 	slen = 0;
1058 	for (mp = m; mp != NULL; mp = mp->m_next)
1059 	    slen += mp->m_len;
1060 	clen = (*sc->sc_xcomp->compress)
1061 	    (sc->sc_xc_state, &mcomp, m, slen, sc->sc_if.if_mtu + PPP_HDRLEN);
1062 	if (mcomp != NULL) {
1063 	    if (sc->sc_flags & SC_CCP_UP) {
1064 		/* Send the compressed packet instead of the original. */
1065 		m_freem(m);
1066 		m = mcomp;
1067 		cp = mtod(m, u_char *);
1068 		protocol = cp[3];
1069 	    } else {
1070 		/* Can't transmit compressed packets until CCP is up. */
1071 		m_freem(mcomp);
1072 	    }
1073 	}
1074     }
1075 #endif	/* PPP_COMPRESS */
1076 
1077     /*
1078      * Compress the address/control and protocol, if possible.
1079      */
1080     if (sc->sc_flags & SC_COMP_AC && address == PPP_ALLSTATIONS &&
1081 	control == PPP_UI && protocol != PPP_ALLSTATIONS &&
1082 	protocol != PPP_LCP) {
1083 	/* can compress address/control */
1084 	m->m_data += 2;
1085 	m->m_len -= 2;
1086     }
1087     if (sc->sc_flags & SC_COMP_PROT && protocol < 0xFF) {
1088 	/* can compress protocol */
1089 	if (mtod(m, u_char *) == cp) {
1090 	    cp[2] = cp[1];	/* move address/control up */
1091 	    cp[1] = cp[0];
1092 	}
1093 	++m->m_data;
1094 	--m->m_len;
1095     }
1096 
1097     return m;
1098 }
1099 
1100 /*
1101  * Software interrupt routine, called at splsoftnet.
1102  */
1103 void
1104 pppintr()
1105 {
1106     struct ppp_softc *sc;
1107     int i, s, s2;
1108     struct mbuf *m;
1109 
1110     sc = ppp_softc;
1111     s = splsoftnet();
1112     for (i = 0; i < NPPP; ++i, ++sc) {
1113 	if (!(sc->sc_flags & SC_TBUSY)
1114 	    && (sc->sc_if.if_snd.ifq_head || sc->sc_fastq.ifq_head
1115 		|| sc->sc_outm)) {
1116 	    s2 = splimp();
1117 	    sc->sc_flags |= SC_TBUSY;
1118 	    splx(s2);
1119 	    (*sc->sc_start)(sc);
1120 	}
1121 	for (;;) {
1122 	    s2 = splimp();
1123 	    IF_DEQUEUE(&sc->sc_rawq, m);
1124 	    splx(s2);
1125 	    if (m == NULL)
1126 		break;
1127 	    ppp_inproc(sc, m);
1128 	}
1129     }
1130     splx(s);
1131 }
1132 
1133 #ifdef PPP_COMPRESS
1134 /*
1135  * Handle a CCP packet.  `rcvd' is 1 if the packet was received,
1136  * 0 if it is about to be transmitted.
1137  */
1138 static void
1139 ppp_ccp(sc, m, rcvd)
1140     struct ppp_softc *sc;
1141     struct mbuf *m;
1142     int rcvd;
1143 {
1144     u_char *dp, *ep;
1145     struct mbuf *mp;
1146     int slen, s;
1147 
1148     /*
1149      * Get a pointer to the data after the PPP header.
1150      */
1151     if (m->m_len <= PPP_HDRLEN) {
1152 	mp = m->m_next;
1153 	if (mp == NULL)
1154 	    return;
1155 	dp = (mp != NULL)? mtod(mp, u_char *): NULL;
1156     } else {
1157 	mp = m;
1158 	dp = mtod(mp, u_char *) + PPP_HDRLEN;
1159     }
1160 
1161     ep = mtod(mp, u_char *) + mp->m_len;
1162     if (dp + CCP_HDRLEN > ep)
1163 	return;
1164     slen = CCP_LENGTH(dp);
1165     if (dp + slen > ep) {
1166 	if (sc->sc_flags & SC_DEBUG)
1167 	    printf("if_ppp/ccp: not enough data in mbuf (%p+%x > %p+%x)\n",
1168 		dp, slen, mtod(mp, u_char *), mp->m_len);
1169 	return;
1170     }
1171 
1172     switch (CCP_CODE(dp)) {
1173     case CCP_CONFREQ:
1174     case CCP_TERMREQ:
1175     case CCP_TERMACK:
1176 	/* CCP must be going down - disable compression */
1177 	if (sc->sc_flags & SC_CCP_UP) {
1178 	    s = splimp();
1179 	    sc->sc_flags &= ~(SC_CCP_UP | SC_COMP_RUN | SC_DECOMP_RUN);
1180 	    splx(s);
1181 	}
1182 	break;
1183 
1184     case CCP_CONFACK:
1185 	if (sc->sc_flags & SC_CCP_OPEN && !(sc->sc_flags & SC_CCP_UP)
1186 	    && slen >= CCP_HDRLEN + CCP_OPT_MINLEN
1187 	    && slen >= CCP_OPT_LENGTH(dp + CCP_HDRLEN) + CCP_HDRLEN) {
1188 	    if (!rcvd) {
1189 		/* we're agreeing to send compressed packets. */
1190 		if (sc->sc_xc_state != NULL
1191 		    && (*sc->sc_xcomp->comp_init)
1192 			(sc->sc_xc_state, dp + CCP_HDRLEN, slen - CCP_HDRLEN,
1193 			 sc->sc_unit, 0, sc->sc_flags & SC_DEBUG)) {
1194 		    s = splimp();
1195 		    sc->sc_flags |= SC_COMP_RUN;
1196 		    splx(s);
1197 		}
1198 	    } else {
1199 		/* peer is agreeing to send compressed packets. */
1200 		if (sc->sc_rc_state != NULL
1201 		    && (*sc->sc_rcomp->decomp_init)
1202 			(sc->sc_rc_state, dp + CCP_HDRLEN, slen - CCP_HDRLEN,
1203 			 sc->sc_unit, 0, sc->sc_mru,
1204 			 sc->sc_flags & SC_DEBUG)) {
1205 		    s = splimp();
1206 		    sc->sc_flags |= SC_DECOMP_RUN;
1207 		    sc->sc_flags &= ~(SC_DC_ERROR | SC_DC_FERROR);
1208 		    splx(s);
1209 		}
1210 	    }
1211 	}
1212 	break;
1213 
1214     case CCP_RESETACK:
1215 	if (sc->sc_flags & SC_CCP_UP) {
1216 	    if (!rcvd) {
1217 		if (sc->sc_xc_state && (sc->sc_flags & SC_COMP_RUN))
1218 		    (*sc->sc_xcomp->comp_reset)(sc->sc_xc_state);
1219 	    } else {
1220 		if (sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)) {
1221 		    (*sc->sc_rcomp->decomp_reset)(sc->sc_rc_state);
1222 		    s = splimp();
1223 		    sc->sc_flags &= ~SC_DC_ERROR;
1224 		    splx(s);
1225 		}
1226 	    }
1227 	}
1228 	break;
1229     }
1230 }
1231 
1232 /*
1233  * CCP is down; free (de)compressor state if necessary.
1234  */
1235 static void
1236 ppp_ccp_closed(sc)
1237     struct ppp_softc *sc;
1238 {
1239     if (sc->sc_xc_state) {
1240 	(*sc->sc_xcomp->comp_free)(sc->sc_xc_state);
1241 	sc->sc_xc_state = NULL;
1242     }
1243     if (sc->sc_rc_state) {
1244 	(*sc->sc_rcomp->decomp_free)(sc->sc_rc_state);
1245 	sc->sc_rc_state = NULL;
1246     }
1247 }
1248 #endif /* PPP_COMPRESS */
1249 
1250 /*
1251  * PPP packet input routine.
1252  * The caller has checked and removed the FCS and has inserted
1253  * the address/control bytes and the protocol high byte if they
1254  * were omitted.
1255  */
1256 void
1257 ppppktin(sc, m, lost)
1258     struct ppp_softc *sc;
1259     struct mbuf *m;
1260     int lost;
1261 {
1262     int s = splimp();
1263 
1264     if (lost)
1265 	m->m_flags |= M_ERRMARK;
1266     IF_ENQUEUE(&sc->sc_rawq, m);
1267     schednetisr(NETISR_PPP);
1268     splx(s);
1269 }
1270 
1271 /*
1272  * Process a received PPP packet, doing decompression as necessary.
1273  * Should be called at splsoftnet.
1274  */
1275 #define COMPTYPE(proto)	((proto) == PPP_VJC_COMP? TYPE_COMPRESSED_TCP: \
1276 			 TYPE_UNCOMPRESSED_TCP)
1277 
1278 static void
1279 ppp_inproc(sc, m)
1280     struct ppp_softc *sc;
1281     struct mbuf *m;
1282 {
1283     struct ifnet *ifp = &sc->sc_if;
1284     struct ifqueue *inq;
1285     int s, ilen, proto, rv;
1286     u_char *cp, adrs, ctrl;
1287     struct mbuf *mp, *dmp = NULL;
1288 #ifdef VJC
1289     int xlen;
1290     u_char *iphdr;
1291     u_int hlen;
1292 #endif
1293 
1294     sc->sc_stats.ppp_ipackets++;
1295 
1296     if (sc->sc_flags & SC_LOG_INPKT) {
1297 	ilen = 0;
1298 	for (mp = m; mp != NULL; mp = mp->m_next)
1299 	    ilen += mp->m_len;
1300 	printf("%s: got %d bytes\n", ifp->if_xname, ilen);
1301 	pppdumpm(m);
1302     }
1303 
1304     cp = mtod(m, u_char *);
1305     adrs = PPP_ADDRESS(cp);
1306     ctrl = PPP_CONTROL(cp);
1307     proto = PPP_PROTOCOL(cp);
1308 
1309     if (m->m_flags & M_ERRMARK) {
1310 	m->m_flags &= ~M_ERRMARK;
1311 	s = splimp();
1312 	sc->sc_flags |= SC_VJ_RESET;
1313 	splx(s);
1314     }
1315 
1316 #ifdef PPP_COMPRESS
1317     /*
1318      * Decompress this packet if necessary, update the receiver's
1319      * dictionary, or take appropriate action on a CCP packet.
1320      */
1321     if (proto == PPP_COMP && sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)
1322 	&& !(sc->sc_flags & SC_DC_ERROR) && !(sc->sc_flags & SC_DC_FERROR)) {
1323 	/* decompress this packet */
1324 	rv = (*sc->sc_rcomp->decompress)(sc->sc_rc_state, m, &dmp);
1325 	if (rv == DECOMP_OK) {
1326 	    m_freem(m);
1327 	    if (dmp == NULL) {
1328 		/* no error, but no decompressed packet produced */
1329 		return;
1330 	    }
1331 	    m = dmp;
1332 	    cp = mtod(m, u_char *);
1333 	    proto = PPP_PROTOCOL(cp);
1334 
1335 	} else {
1336 	    /*
1337 	     * An error has occurred in decompression.
1338 	     * Pass the compressed packet up to pppd, which may take
1339 	     * CCP down or issue a Reset-Req.
1340 	     */
1341 	    if (sc->sc_flags & SC_DEBUG)
1342 		printf("%s: decompress failed %d\n", ifp->if_xname, rv);
1343 	    s = splimp();
1344 	    sc->sc_flags |= SC_VJ_RESET;
1345 	    if (rv == DECOMP_ERROR)
1346 		sc->sc_flags |= SC_DC_ERROR;
1347 	    else
1348 		sc->sc_flags |= SC_DC_FERROR;
1349 	    splx(s);
1350 	}
1351 
1352     } else {
1353 	if (sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)) {
1354 	    (*sc->sc_rcomp->incomp)(sc->sc_rc_state, m);
1355 	}
1356 	if (proto == PPP_CCP) {
1357 	    ppp_ccp(sc, m, 1);
1358 	}
1359     }
1360 #endif
1361 
1362     ilen = 0;
1363     for (mp = m; mp != NULL; mp = mp->m_next)
1364 	ilen += mp->m_len;
1365 
1366 #ifdef VJC
1367     if (sc->sc_flags & SC_VJ_RESET) {
1368 	/*
1369 	 * If we've missed a packet, we must toss subsequent compressed
1370 	 * packets which don't have an explicit connection ID.
1371 	 */
1372 	if (sc->sc_comp)
1373 	    sl_uncompress_tcp(NULL, 0, TYPE_ERROR, sc->sc_comp);
1374 	s = splimp();
1375 	sc->sc_flags &= ~SC_VJ_RESET;
1376 	splx(s);
1377     }
1378 
1379     /*
1380      * See if we have a VJ-compressed packet to uncompress.
1381      */
1382     if (proto == PPP_VJC_COMP) {
1383 	if ((sc->sc_flags & SC_REJ_COMP_TCP) || sc->sc_comp == 0)
1384 	    goto bad;
1385 
1386 	xlen = sl_uncompress_tcp_core(cp + PPP_HDRLEN, m->m_len - PPP_HDRLEN,
1387 				      ilen - PPP_HDRLEN, TYPE_COMPRESSED_TCP,
1388 				      sc->sc_comp, &iphdr, &hlen);
1389 
1390 	if (xlen <= 0) {
1391 	    if (sc->sc_flags & SC_DEBUG)
1392 		printf("%s: VJ uncompress failed on type comp\n",
1393 		    ifp->if_xname);
1394 	    goto bad;
1395 	}
1396 
1397 	/* Copy the PPP and IP headers into a new mbuf. */
1398 	MGETHDR(mp, M_DONTWAIT, MT_DATA);
1399 	if (mp == NULL)
1400 	    goto bad;
1401 	mp->m_len = 0;
1402 	mp->m_next = NULL;
1403 	if (hlen + PPP_HDRLEN > MHLEN) {
1404 	    MCLGET(mp, M_DONTWAIT);
1405 	    if (M_TRAILINGSPACE(mp) < hlen + PPP_HDRLEN) {
1406 		m_freem(mp);
1407 		goto bad;	/* lose if big headers and no clusters */
1408 	    }
1409 	}
1410 	cp = mtod(mp, u_char *);
1411 	cp[0] = adrs;
1412 	cp[1] = ctrl;
1413 	cp[2] = 0;
1414 	cp[3] = PPP_IP;
1415 	proto = PPP_IP;
1416 	bcopy(iphdr, cp + PPP_HDRLEN, hlen);
1417 	mp->m_len = hlen + PPP_HDRLEN;
1418 
1419 	/*
1420 	 * Trim the PPP and VJ headers off the old mbuf
1421 	 * and stick the new and old mbufs together.
1422 	 */
1423 	m->m_data += PPP_HDRLEN + xlen;
1424 	m->m_len -= PPP_HDRLEN + xlen;
1425 	if (m->m_len <= M_TRAILINGSPACE(mp)) {
1426 	    bcopy(mtod(m, u_char *), mtod(mp, u_char *) + mp->m_len, m->m_len);
1427 	    mp->m_len += m->m_len;
1428 	    MFREE(m, mp->m_next);
1429 	} else
1430 	    mp->m_next = m;
1431 	m = mp;
1432 	ilen += hlen - xlen;
1433 
1434     } else if (proto == PPP_VJC_UNCOMP) {
1435 	if ((sc->sc_flags & SC_REJ_COMP_TCP) || sc->sc_comp == 0)
1436 	    goto bad;
1437 
1438 	xlen = sl_uncompress_tcp_core(cp + PPP_HDRLEN, m->m_len - PPP_HDRLEN,
1439 				      ilen - PPP_HDRLEN, TYPE_UNCOMPRESSED_TCP,
1440 				      sc->sc_comp, &iphdr, &hlen);
1441 
1442 	if (xlen < 0) {
1443 	    if (sc->sc_flags & SC_DEBUG)
1444 		printf("%s: VJ uncompress failed on type uncomp\n",
1445 		    ifp->if_xname);
1446 	    goto bad;
1447 	}
1448 
1449 	proto = PPP_IP;
1450 	cp[3] = PPP_IP;
1451     }
1452 #endif /* VJC */
1453 
1454     /*
1455      * If the packet will fit in a header mbuf, don't waste a
1456      * whole cluster on it.
1457      */
1458     if (ilen <= MHLEN && M_IS_CLUSTER(m)) {
1459 	MGETHDR(mp, M_DONTWAIT, MT_DATA);
1460 	if (mp != NULL) {
1461 	    m_copydata(m, 0, ilen, mtod(mp, caddr_t));
1462 	    m_freem(m);
1463 	    m = mp;
1464 	    m->m_len = ilen;
1465 	}
1466     }
1467     m->m_pkthdr.len = ilen;
1468     m->m_pkthdr.rcvif = ifp;
1469 
1470     if ((proto & 0x8000) == 0) {
1471 #ifdef PPP_FILTER
1472 	/*
1473 	 * See whether we want to pass this packet, and
1474 	 * if it counts as link activity.
1475 	 */
1476 	if (sc->sc_pass_filt_in.bf_insns != 0
1477 	    && bpf_filter(sc->sc_pass_filt_in.bf_insns, (u_char *) m,
1478 			  ilen, 0) == 0) {
1479 	    /* drop this packet */
1480 	    m_freem(m);
1481 	    return;
1482 	}
1483 	if (sc->sc_active_filt_in.bf_insns == 0
1484 	    || bpf_filter(sc->sc_active_filt_in.bf_insns, (u_char *) m,
1485 	    		  ilen, 0))
1486 	    sc->sc_last_recv = time.tv_sec;
1487 #else
1488 	/*
1489 	 * Record the time that we received this packet.
1490 	 */
1491 	sc->sc_last_recv = time.tv_sec;
1492 #endif /* PPP_FILTER */
1493     }
1494 
1495 #if NBPFILTER > 0
1496     /* See if bpf wants to look at the packet. */
1497     if (sc->sc_if.if_bpf)
1498 	bpf_mtap(sc->sc_if.if_bpf, m);
1499 #endif
1500 
1501     rv = 0;
1502     switch (proto) {
1503 #ifdef INET
1504     case PPP_IP:
1505 	/*
1506 	 * IP packet - take off the ppp header and pass it up to IP.
1507 	 */
1508 	if ((ifp->if_flags & IFF_UP) == 0
1509 	    || sc->sc_npmode[NP_IP] != NPMODE_PASS) {
1510 	    /* interface is down - drop the packet. */
1511 	    m_freem(m);
1512 	    return;
1513 	}
1514 	m->m_pkthdr.len -= PPP_HDRLEN;
1515 	m->m_data += PPP_HDRLEN;
1516 	m->m_len -= PPP_HDRLEN;
1517 #ifdef GATEWAY
1518 	if (ipflow_fastforward(m))
1519 		return;
1520 #endif
1521 	schednetisr(NETISR_IP);
1522 	inq = &ipintrq;
1523 	break;
1524 #endif
1525 
1526 #ifdef INET6
1527     case PPP_IPV6:
1528 	/*
1529 	 * IPv6 packet - take off the ppp header and pass it up to IPv6.
1530 	 */
1531 	if ((ifp->if_flags & IFF_UP) == 0
1532 	    || sc->sc_npmode[NP_IPV6] != NPMODE_PASS) {
1533 	    /* interface is down - drop the packet. */
1534 	    m_freem(m);
1535 	    return;
1536 	}
1537 	m->m_pkthdr.len -= PPP_HDRLEN;
1538 	m->m_data += PPP_HDRLEN;
1539 	m->m_len -= PPP_HDRLEN;
1540 	schednetisr(NETISR_IPV6);
1541 	inq = &ip6intrq;
1542 	break;
1543 #endif
1544 
1545     default:
1546 	/*
1547 	 * Some other protocol - place on input queue for read().
1548 	 */
1549 	inq = &sc->sc_inq;
1550 	rv = 1;
1551 	break;
1552     }
1553 
1554     /*
1555      * Put the packet on the appropriate input queue.
1556      */
1557     s = splimp();
1558     if (IF_QFULL(inq)) {
1559 	IF_DROP(inq);
1560 	splx(s);
1561 	if (sc->sc_flags & SC_DEBUG)
1562 	    printf("%s: input queue full\n", ifp->if_xname);
1563 	ifp->if_iqdrops++;
1564 	goto bad;
1565     }
1566     IF_ENQUEUE(inq, m);
1567     splx(s);
1568     ifp->if_ipackets++;
1569     ifp->if_ibytes += ilen;
1570     ifp->if_lastchange = time;
1571 
1572     if (rv)
1573 	(*sc->sc_ctlp)(sc);
1574 
1575     return;
1576 
1577  bad:
1578     m_freem(m);
1579     sc->sc_if.if_ierrors++;
1580     sc->sc_stats.ppp_ierrors++;
1581 }
1582 
1583 #define MAX_DUMP_BYTES	128
1584 
1585 static void
1586 pppdumpm(m0)
1587     struct mbuf *m0;
1588 {
1589     char buf[3*MAX_DUMP_BYTES+4];
1590     char *bp = buf;
1591     struct mbuf *m;
1592     static char digits[] = "0123456789abcdef";
1593 
1594     for (m = m0; m; m = m->m_next) {
1595 	int l = m->m_len;
1596 	u_char *rptr = (u_char *)m->m_data;
1597 
1598 	while (l--) {
1599 	    if (bp > buf + sizeof(buf) - 4)
1600 		goto done;
1601 	    *bp++ = digits[*rptr >> 4]; /* convert byte to ascii hex */
1602 	    *bp++ = digits[*rptr++ & 0xf];
1603 	}
1604 
1605 	if (m->m_next) {
1606 	    if (bp > buf + sizeof(buf) - 3)
1607 		goto done;
1608 	    *bp++ = '|';
1609 	} else
1610 	    *bp++ = ' ';
1611     }
1612 done:
1613     if (m)
1614 	*bp++ = '>';
1615     *bp = 0;
1616     printf("%s\n", buf);
1617 }
1618 
1619 #endif	/* NPPP > 0 */
1620