xref: /netbsd-src/sys/net/if_ppp.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: if_ppp.c,v 1.40 1997/06/16 17:01:36 christos 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 #if NPPP > 0
80 
81 #define VJC
82 #define PPP_COMPRESS
83 
84 #include <sys/param.h>
85 #include <sys/proc.h>
86 #include <sys/mbuf.h>
87 #include <sys/socket.h>
88 #include <sys/ioctl.h>
89 #include <sys/kernel.h>
90 #include <sys/systm.h>
91 #include <sys/time.h>
92 #include <sys/malloc.h>
93 
94 #include <net/if.h>
95 #include <net/if_types.h>
96 #include <net/netisr.h>
97 #include <net/route.h>
98 #ifdef PPP_FILTER
99 #include <net/bpf.h>
100 #endif
101 
102 #if INET
103 #include <netinet/in.h>
104 #include <netinet/in_systm.h>
105 #include <netinet/in_var.h>
106 #include <netinet/ip.h>
107 #endif
108 
109 #include "bpfilter.h"
110 #if NBPFILTER > 0
111 #include <sys/time.h>
112 #include <net/bpf.h>
113 #endif
114 
115 #ifdef VJC
116 #include <net/slcompress.h>
117 #endif
118 
119 #include <net/ppp_defs.h>
120 #include <net/if_ppp.h>
121 #include <net/if_pppvar.h>
122 #include <machine/cpu.h>
123 
124 #ifdef PPP_COMPRESS
125 #define PACKETPTR	struct mbuf *
126 #include <net/ppp-comp.h>
127 #endif
128 
129 static int	pppsioctl __P((struct ifnet *, u_long, caddr_t));
130 static void	ppp_requeue __P((struct ppp_softc *));
131 static void	ppp_ccp __P((struct ppp_softc *, struct mbuf *m, int rcvd));
132 static void	ppp_ccp_closed __P((struct ppp_softc *));
133 static void	ppp_inproc __P((struct ppp_softc *, struct mbuf *));
134 static void	pppdumpm __P((struct mbuf *m0));
135 
136 /*
137  * Some useful mbuf macros not in mbuf.h.
138  */
139 #define M_IS_CLUSTER(m)	((m)->m_flags & M_EXT)
140 
141 #define M_DATASTART(m)	\
142 	(M_IS_CLUSTER(m) ? (m)->m_ext.ext_buf : \
143 	    (m)->m_flags & M_PKTHDR ? (m)->m_pktdat : (m)->m_dat)
144 
145 #define M_DATASIZE(m)	\
146 	(M_IS_CLUSTER(m) ? (m)->m_ext.ext_size : \
147 	    (m)->m_flags & M_PKTHDR ? MHLEN: MLEN)
148 
149 /*
150  * We steal two bits in the mbuf m_flags, to mark high-priority packets
151  * for output, and received packets following lost/corrupted packets.
152  */
153 #define M_HIGHPRI	0x2000	/* output packet for sc_fastq */
154 #define M_ERRMARK	0x4000	/* steal a bit in mbuf m_flags */
155 
156 
157 #ifdef PPP_COMPRESS
158 /*
159  * List of compressors we know about.
160  * We leave some space so maybe we can modload compressors.
161  */
162 
163 extern struct compressor ppp_bsd_compress;
164 extern struct compressor ppp_deflate;
165 
166 struct compressor *ppp_compressors[8] = {
167 #if DO_BSD_COMPRESS && defined(PPP_BSDCOMP)
168     &ppp_bsd_compress,
169 #endif
170 #if DO_DEFLATE && defined(PPP_DEFLATE)
171     &ppp_deflate,
172 #endif
173     NULL
174 };
175 #endif /* PPP_COMPRESS */
176 
177 
178 /*
179  * Called from boot code to establish ppp interfaces.
180  */
181 void
182 pppattach()
183 {
184     register struct ppp_softc *sc;
185     register int i = 0;
186 
187     for (sc = ppp_softc; i < NPPP; sc++) {
188 	sc->sc_unit = i;	/* XXX */
189 	sprintf(sc->sc_if.if_xname, "ppp%d", i++);
190 	sc->sc_if.if_softc = sc;
191 	sc->sc_if.if_mtu = PPP_MTU;
192 	sc->sc_if.if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
193 	sc->sc_if.if_type = IFT_PPP;
194 	sc->sc_if.if_hdrlen = PPP_HDRLEN;
195 	sc->sc_if.if_ioctl = pppsioctl;
196 	sc->sc_if.if_output = pppoutput;
197 	sc->sc_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
198 	sc->sc_inq.ifq_maxlen = IFQ_MAXLEN;
199 	sc->sc_fastq.ifq_maxlen = IFQ_MAXLEN;
200 	sc->sc_rawq.ifq_maxlen = IFQ_MAXLEN;
201 	if_attach(&sc->sc_if);
202 #if NBPFILTER > 0
203 	bpfattach(&sc->sc_bpf, &sc->sc_if, DLT_PPP, PPP_HDRLEN);
204 #endif
205     }
206 }
207 
208 /*
209  * Allocate a ppp interface unit and initialize it.
210  */
211 struct ppp_softc *
212 pppalloc(pid)
213     pid_t pid;
214 {
215     int nppp, i;
216     struct ppp_softc *sc;
217 
218     for (nppp = 0, sc = ppp_softc; nppp < NPPP; nppp++, sc++)
219 	if (sc->sc_xfer == pid) {
220 	    sc->sc_xfer = 0;
221 	    return sc;
222 	}
223     for (nppp = 0, sc = ppp_softc; nppp < NPPP; nppp++, sc++)
224 	if (sc->sc_devp == NULL)
225 	    break;
226     if (nppp >= NPPP)
227 	return NULL;
228 
229     sc->sc_flags = 0;
230     sc->sc_mru = PPP_MRU;
231     sc->sc_relinq = NULL;
232     bzero((char *)&sc->sc_stats, sizeof(sc->sc_stats));
233 #ifdef VJC
234     MALLOC(sc->sc_comp, struct slcompress *, sizeof(struct slcompress),
235 	   M_DEVBUF, M_NOWAIT);
236     if (sc->sc_comp)
237 	sl_compress_init(sc->sc_comp);
238 #endif
239 #ifdef PPP_COMPRESS
240     sc->sc_xc_state = NULL;
241     sc->sc_rc_state = NULL;
242 #endif /* PPP_COMPRESS */
243     for (i = 0; i < NUM_NP; ++i)
244 	sc->sc_npmode[i] = NPMODE_ERROR;
245     sc->sc_npqueue = NULL;
246     sc->sc_npqtail = &sc->sc_npqueue;
247     sc->sc_last_sent = sc->sc_last_recv = time.tv_sec;
248 
249     return sc;
250 }
251 
252 /*
253  * Deallocate a ppp unit.  Must be called at splsoftnet or higher.
254  */
255 void
256 pppdealloc(sc)
257     struct ppp_softc *sc;
258 {
259     struct mbuf *m;
260 
261     if_down(&sc->sc_if);
262     sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
263     sc->sc_devp = NULL;
264     sc->sc_xfer = 0;
265     for (;;) {
266 	IF_DEQUEUE(&sc->sc_rawq, m);
267 	if (m == NULL)
268 	    break;
269 	m_freem(m);
270     }
271     for (;;) {
272 	IF_DEQUEUE(&sc->sc_inq, m);
273 	if (m == NULL)
274 	    break;
275 	m_freem(m);
276     }
277     for (;;) {
278 	IF_DEQUEUE(&sc->sc_fastq, m);
279 	if (m == NULL)
280 	    break;
281 	m_freem(m);
282     }
283     while ((m = sc->sc_npqueue) != NULL) {
284 	sc->sc_npqueue = m->m_nextpkt;
285 	m_freem(m);
286     }
287     if (sc->sc_togo != NULL) {
288 	m_freem(sc->sc_togo);
289 	sc->sc_togo = NULL;
290     }
291 #ifdef PPP_COMPRESS
292     ppp_ccp_closed(sc);
293     sc->sc_xc_state = NULL;
294     sc->sc_rc_state = NULL;
295 #endif /* PPP_COMPRESS */
296 #ifdef PPP_FILTER
297     if (sc->sc_pass_filt.bf_insns != 0) {
298 	FREE(sc->sc_pass_filt.bf_insns, M_DEVBUF);
299 	sc->sc_pass_filt.bf_insns = 0;
300 	sc->sc_pass_filt.bf_len = 0;
301     }
302     if (sc->sc_active_filt.bf_insns != 0) {
303 	FREE(sc->sc_active_filt.bf_insns, M_DEVBUF);
304 	sc->sc_active_filt.bf_insns = 0;
305 	sc->sc_active_filt.bf_len = 0;
306     }
307 #endif /* PPP_FILTER */
308 #ifdef VJC
309     if (sc->sc_comp != 0) {
310 	FREE(sc->sc_comp, M_DEVBUF);
311 	sc->sc_comp = 0;
312     }
313 #endif
314 }
315 
316 /*
317  * Ioctl routine for generic ppp devices.
318  */
319 int
320 pppioctl(sc, cmd, data, flag, p)
321     struct ppp_softc *sc;
322     u_long cmd;
323     caddr_t data;
324     int flag;
325     struct proc *p;
326 {
327     int s, error, flags, mru, nb, npx;
328     struct ppp_option_data *odp;
329     struct compressor **cp;
330     struct npioctl *npi;
331     time_t t;
332 #ifdef PPP_FILTER
333     struct bpf_program *bp, *nbp;
334     struct bpf_insn *newcode, *oldcode;
335     int newcodelen;
336 #endif /* PPP_FILTER */
337 #ifdef	PPP_COMPRESS
338     u_char ccp_option[CCP_MAX_OPTION_LENGTH];
339 #endif
340 
341     switch (cmd) {
342     case FIONREAD:
343 	*(int *)data = sc->sc_inq.ifq_len;
344 	break;
345 
346     case PPPIOCGUNIT:
347 	*(int *)data = sc->sc_unit;	/* XXX */
348 	break;
349 
350     case PPPIOCGFLAGS:
351 	*(u_int *)data = sc->sc_flags;
352 	break;
353 
354     case PPPIOCSFLAGS:
355 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
356 	    return (error);
357 	flags = *(int *)data & SC_MASK;
358 	s = splsoftnet();
359 #ifdef PPP_COMPRESS
360 	if (sc->sc_flags & SC_CCP_OPEN && !(flags & SC_CCP_OPEN))
361 	    ppp_ccp_closed(sc);
362 #endif
363 	splimp();
364 	sc->sc_flags = (sc->sc_flags & ~SC_MASK) | flags;
365 	splx(s);
366 	break;
367 
368     case PPPIOCSMRU:
369 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
370 	    return (error);
371 	mru = *(int *)data;
372 	if (mru >= PPP_MRU && mru <= PPP_MAXMRU)
373 	    sc->sc_mru = mru;
374 	break;
375 
376     case PPPIOCGMRU:
377 	*(int *)data = sc->sc_mru;
378 	break;
379 
380 #ifdef VJC
381     case PPPIOCSMAXCID:
382 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
383 	    return (error);
384 	if (sc->sc_comp) {
385 	    s = splsoftnet();
386 	    sl_compress_setup(sc->sc_comp, *(int *)data);
387 	    splx(s);
388 	}
389 	break;
390 #endif
391 
392     case PPPIOCXFERUNIT:
393 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
394 	    return (error);
395 	sc->sc_xfer = p->p_pid;
396 	break;
397 
398 #ifdef PPP_COMPRESS
399     case PPPIOCSCOMPRESS:
400 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
401 	    return (error);
402 	odp = (struct ppp_option_data *) data;
403 	nb = odp->length;
404 	if (nb > sizeof(ccp_option))
405 	    nb = sizeof(ccp_option);
406 	if ((error = copyin(odp->ptr, ccp_option, nb)) != 0)
407 	    return (error);
408 	if (ccp_option[1] < 2)	/* preliminary check on the length byte */
409 	    return (EINVAL);
410 	for (cp = ppp_compressors; *cp != NULL; ++cp)
411 	    if ((*cp)->compress_proto == ccp_option[0]) {
412 		/*
413 		 * Found a handler for the protocol - try to allocate
414 		 * a compressor or decompressor.
415 		 */
416 		error = 0;
417 		if (odp->transmit) {
418 		    s = splsoftnet();
419 		    if (sc->sc_xc_state != NULL)
420 			(*sc->sc_xcomp->comp_free)(sc->sc_xc_state);
421 		    sc->sc_xcomp = *cp;
422 		    sc->sc_xc_state = (*cp)->comp_alloc(ccp_option, nb);
423 		    if (sc->sc_xc_state == NULL) {
424 			if (sc->sc_flags & SC_DEBUG)
425 			    printf("%s: comp_alloc failed\n",
426 				sc->sc_if.if_xname);
427 			error = ENOBUFS;
428 		    }
429 		    splimp();
430 		    sc->sc_flags &= ~SC_COMP_RUN;
431 		    splx(s);
432 		} else {
433 		    s = splsoftnet();
434 		    if (sc->sc_rc_state != NULL)
435 			(*sc->sc_rcomp->decomp_free)(sc->sc_rc_state);
436 		    sc->sc_rcomp = *cp;
437 		    sc->sc_rc_state = (*cp)->decomp_alloc(ccp_option, nb);
438 		    if (sc->sc_rc_state == NULL) {
439 			if (sc->sc_flags & SC_DEBUG)
440 			    printf("%s: decomp_alloc failed\n",
441 				sc->sc_if.if_xname);
442 			error = ENOBUFS;
443 		    }
444 		    splimp();
445 		    sc->sc_flags &= ~SC_DECOMP_RUN;
446 		    splx(s);
447 		}
448 		return (error);
449 	    }
450 	if (sc->sc_flags & SC_DEBUG)
451 	    printf("%s: no compressor for [%x %x %x], %x\n",
452 		sc->sc_if.if_xname, ccp_option[0], ccp_option[1],
453 		ccp_option[2], nb);
454 	return (EINVAL);	/* no handler found */
455 #endif /* PPP_COMPRESS */
456 
457     case PPPIOCGNPMODE:
458     case PPPIOCSNPMODE:
459 	npi = (struct npioctl *) data;
460 	switch (npi->protocol) {
461 	case PPP_IP:
462 	    npx = NP_IP;
463 	    break;
464 	default:
465 	    return EINVAL;
466 	}
467 	if (cmd == PPPIOCGNPMODE) {
468 	    npi->mode = sc->sc_npmode[npx];
469 	} else {
470 	    if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
471 		return (error);
472 	    if (npi->mode != sc->sc_npmode[npx]) {
473 		s = splsoftnet();
474 		sc->sc_npmode[npx] = npi->mode;
475 		if (npi->mode != NPMODE_QUEUE) {
476 		    ppp_requeue(sc);
477 		    (*sc->sc_start)(sc);
478 		}
479 		splx(s);
480 	    }
481 	}
482 	break;
483 
484     case PPPIOCGIDLE:
485 	s = splsoftnet();
486 	t = time.tv_sec;
487 	((struct ppp_idle *)data)->xmit_idle = t - sc->sc_last_sent;
488 	((struct ppp_idle *)data)->recv_idle = t - sc->sc_last_recv;
489 	splx(s);
490 	break;
491 
492 #ifdef PPP_FILTER
493     case PPPIOCSPASS:
494     case PPPIOCSACTIVE:
495 	nbp = (struct bpf_program *) data;
496 	if ((unsigned) nbp->bf_len > BPF_MAXINSNS)
497 	    return EINVAL;
498 	newcodelen = nbp->bf_len * sizeof(struct bpf_insn);
499 	if (newcodelen != 0) {
500 	    MALLOC(newcode, struct bpf_insn *, newcodelen, M_DEVBUF, M_WAITOK);
501 	    if (newcode == 0) {
502 		return EINVAL;		/* or sumpin */
503 	    }
504 	    if ((error = copyin((caddr_t)nbp->bf_insns, (caddr_t)newcode,
505 			       newcodelen)) != 0) {
506 		FREE(newcode, M_DEVBUF);
507 		return error;
508 	    }
509 	    if (!bpf_validate(newcode, nbp->bf_len)) {
510 		FREE(newcode, M_DEVBUF);
511 		return EINVAL;
512 	    }
513 	} else
514 	    newcode = 0;
515 	bp = (cmd == PPPIOCSPASS)? &sc->sc_pass_filt: &sc->sc_active_filt;
516 	oldcode = bp->bf_insns;
517 	s = splimp();
518 	bp->bf_len = nbp->bf_len;
519 	bp->bf_insns = newcode;
520 	splx(s);
521 	if (oldcode != 0)
522 	    FREE(oldcode, M_DEVBUF);
523 	break;
524 #endif
525 
526     default:
527 	return (-1);
528     }
529     return (0);
530 }
531 
532 /*
533  * Process an ioctl request to the ppp network interface.
534  */
535 static int
536 pppsioctl(ifp, cmd, data)
537     register struct ifnet *ifp;
538     u_long cmd;
539     caddr_t data;
540 {
541     register struct proc *p = curproc;	/* XXX */
542     register struct ppp_softc *sc = ifp->if_softc;
543     register struct ifaddr *ifa = (struct ifaddr *)data;
544     register struct ifreq *ifr = (struct ifreq *)data;
545     struct ppp_stats *psp;
546 #ifdef	PPP_COMPRESS
547     struct ppp_comp_stats *pcp;
548 #endif
549     int s = splimp(), error = 0;
550 
551     switch (cmd) {
552     case SIOCSIFFLAGS:
553 	if ((ifp->if_flags & IFF_RUNNING) == 0)
554 	    ifp->if_flags &= ~IFF_UP;
555 	break;
556 
557     case SIOCSIFADDR:
558 	if (ifa->ifa_addr->sa_family != AF_INET)
559 	    error = EAFNOSUPPORT;
560 	break;
561 
562     case SIOCSIFDSTADDR:
563 	if (ifa->ifa_addr->sa_family != AF_INET)
564 	    error = EAFNOSUPPORT;
565 	break;
566 
567     case SIOCSIFMTU:
568 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
569 	    break;
570 	sc->sc_if.if_mtu = ifr->ifr_mtu;
571 	break;
572 
573     case SIOCGIFMTU:
574 	ifr->ifr_mtu = sc->sc_if.if_mtu;
575 	break;
576 
577     case SIOCADDMULTI:
578     case SIOCDELMULTI:
579 	if (ifr == 0) {
580 	    error = EAFNOSUPPORT;
581 	    break;
582 	}
583 	switch(ifr->ifr_addr.sa_family) {
584 #ifdef INET
585 	case AF_INET:
586 	    break;
587 #endif
588 	default:
589 	    error = EAFNOSUPPORT;
590 	    break;
591 	}
592 	break;
593 
594     case SIOCGPPPSTATS:
595 	psp = &((struct ifpppstatsreq *) data)->stats;
596 	bzero(psp, sizeof(*psp));
597 	psp->p = sc->sc_stats;
598 #if defined(VJC) && !defined(SL_NO_STATS)
599 	if (sc->sc_comp) {
600 	    psp->vj.vjs_packets = sc->sc_comp->sls_packets;
601 	    psp->vj.vjs_compressed = sc->sc_comp->sls_compressed;
602 	    psp->vj.vjs_searches = sc->sc_comp->sls_searches;
603 	    psp->vj.vjs_misses = sc->sc_comp->sls_misses;
604 	    psp->vj.vjs_uncompressedin = sc->sc_comp->sls_uncompressedin;
605 	    psp->vj.vjs_compressedin = sc->sc_comp->sls_compressedin;
606 	    psp->vj.vjs_errorin = sc->sc_comp->sls_errorin;
607 	    psp->vj.vjs_tossed = sc->sc_comp->sls_tossed;
608 	}
609 #endif /* VJC */
610 	break;
611 
612 #ifdef PPP_COMPRESS
613     case SIOCGPPPCSTATS:
614 	pcp = &((struct ifpppcstatsreq *) data)->stats;
615 	bzero(pcp, sizeof(*pcp));
616 	if (sc->sc_xc_state != NULL)
617 	    (*sc->sc_xcomp->comp_stat)(sc->sc_xc_state, &pcp->c);
618 	if (sc->sc_rc_state != NULL)
619 	    (*sc->sc_rcomp->decomp_stat)(sc->sc_rc_state, &pcp->d);
620 	break;
621 #endif /* PPP_COMPRESS */
622 
623     default:
624 	error = EINVAL;
625     }
626     splx(s);
627     return (error);
628 }
629 
630 /*
631  * Queue a packet.  Start transmission if not active.
632  * Packet is placed in Information field of PPP frame.
633  */
634 int
635 pppoutput(ifp, m0, dst, rtp)
636     struct ifnet *ifp;
637     struct mbuf *m0;
638     struct sockaddr *dst;
639     struct rtentry *rtp;
640 {
641     register struct ppp_softc *sc = ifp->if_softc;
642     int protocol, address, control;
643     u_char *cp;
644     int s, error;
645     struct ip *ip;
646     struct ifqueue *ifq;
647     enum NPmode mode;
648     int len;
649     struct mbuf *m;
650 
651     if (sc->sc_devp == NULL || (ifp->if_flags & IFF_RUNNING) == 0
652 	|| ((ifp->if_flags & IFF_UP) == 0 && dst->sa_family != AF_UNSPEC)) {
653 	error = ENETDOWN;	/* sort of */
654 	goto bad;
655     }
656 
657     /*
658      * Compute PPP header.
659      */
660     m0->m_flags &= ~M_HIGHPRI;
661     switch (dst->sa_family) {
662 #ifdef INET
663     case AF_INET:
664 	address = PPP_ALLSTATIONS;
665 	control = PPP_UI;
666 	protocol = PPP_IP;
667 	mode = sc->sc_npmode[NP_IP];
668 
669 	/*
670 	 * If this packet has the "low delay" bit set in the IP header,
671 	 * put it on the fastq instead.
672 	 */
673 	ip = mtod(m0, struct ip *);
674 	if (ip->ip_tos & IPTOS_LOWDELAY)
675 	    m0->m_flags |= M_HIGHPRI;
676 	break;
677 #endif
678     case AF_UNSPEC:
679 	address = PPP_ADDRESS(dst->sa_data);
680 	control = PPP_CONTROL(dst->sa_data);
681 	protocol = PPP_PROTOCOL(dst->sa_data);
682 	mode = NPMODE_PASS;
683 	break;
684     default:
685 	printf("%s: af%d not supported\n", ifp->if_xname, dst->sa_family);
686 	error = EAFNOSUPPORT;
687 	goto bad;
688     }
689 
690     /*
691      * Drop this packet, or return an error, if necessary.
692      */
693     if (mode == NPMODE_ERROR) {
694 	error = ENETDOWN;
695 	goto bad;
696     }
697     if (mode == NPMODE_DROP) {
698 	error = 0;
699 	goto bad;
700     }
701 
702     /*
703      * Add PPP header.  If no space in first mbuf, allocate another.
704      * (This assumes M_LEADINGSPACE is always 0 for a cluster mbuf.)
705      */
706     if (M_LEADINGSPACE(m0) < PPP_HDRLEN) {
707 	m0 = m_prepend(m0, PPP_HDRLEN, M_DONTWAIT);
708 	if (m0 == 0) {
709 	    error = ENOBUFS;
710 	    goto bad;
711 	}
712 	m0->m_len = 0;
713     } else
714 	m0->m_data -= PPP_HDRLEN;
715 
716     cp = mtod(m0, u_char *);
717     *cp++ = address;
718     *cp++ = control;
719     *cp++ = protocol >> 8;
720     *cp++ = protocol & 0xff;
721     m0->m_len += PPP_HDRLEN;
722 
723     len = 0;
724     for (m = m0; m != 0; m = m->m_next)
725 	len += m->m_len;
726 
727     if (sc->sc_flags & SC_LOG_OUTPKT) {
728 	printf("%s output: ", ifp->if_xname);
729 	pppdumpm(m0);
730     }
731 
732     if ((protocol & 0x8000) == 0) {
733 #ifdef PPP_FILTER
734 	/*
735 	 * Apply the pass and active filters to the packet,
736 	 * but only if it is a data packet.
737 	 */
738 	*mtod(m0, u_char *) = 1;	/* indicates outbound */
739 	if (sc->sc_pass_filt.bf_insns != 0
740 	    && bpf_filter(sc->sc_pass_filt.bf_insns, (u_char *) m0,
741 			  len, 0) == 0) {
742 	    error = 0;		/* drop this packet */
743 	    goto bad;
744 	}
745 
746 	/*
747 	 * Update the time we sent the most recent packet.
748 	 */
749 	if (sc->sc_active_filt.bf_insns == 0
750 	    || bpf_filter(sc->sc_active_filt.bf_insns, (u_char *) m0, len, 0))
751 	    sc->sc_last_sent = time.tv_sec;
752 
753 	*mtod(m0, u_char *) = address;
754 #else
755 	/*
756 	 * Update the time we sent the most recent packet.
757 	 */
758 	sc->sc_last_sent = time.tv_sec;
759 #endif /* PPP_FILTER */
760     }
761 
762 #if NBPFILTER > 0
763     /*
764      * See if bpf wants to look at the packet.
765      */
766     if (sc->sc_bpf)
767 	bpf_mtap(sc->sc_bpf, m0);
768 #endif
769 
770     /*
771      * Put the packet on the appropriate queue.
772      */
773     s = splsoftnet();
774     if (mode == NPMODE_QUEUE) {
775 	/* XXX we should limit the number of packets on this queue */
776 	*sc->sc_npqtail = m0;
777 	m0->m_nextpkt = NULL;
778 	sc->sc_npqtail = &m0->m_nextpkt;
779     } else {
780 	ifq = (m0->m_flags & M_HIGHPRI)? &sc->sc_fastq: &ifp->if_snd;
781 	if (IF_QFULL(ifq) && dst->sa_family != AF_UNSPEC) {
782 	    IF_DROP(ifq);
783 	    splx(s);
784 	    sc->sc_if.if_oerrors++;
785 	    sc->sc_stats.ppp_oerrors++;
786 	    error = ENOBUFS;
787 	    goto bad;
788 	}
789 	IF_ENQUEUE(ifq, m0);
790 	(*sc->sc_start)(sc);
791     }
792     ifp->if_lastchange = time;
793     ifp->if_opackets++;
794     ifp->if_obytes += len;
795 
796     splx(s);
797     return (0);
798 
799 bad:
800     m_freem(m0);
801     return (error);
802 }
803 
804 /*
805  * After a change in the NPmode for some NP, move packets from the
806  * npqueue to the send queue or the fast queue as appropriate.
807  * Should be called at splsoftnet.
808  */
809 static void
810 ppp_requeue(sc)
811     struct ppp_softc *sc;
812 {
813     struct mbuf *m, **mpp;
814     struct ifqueue *ifq;
815     enum NPmode mode;
816 
817     for (mpp = &sc->sc_npqueue; (m = *mpp) != NULL; ) {
818 	switch (PPP_PROTOCOL(mtod(m, u_char *))) {
819 	case PPP_IP:
820 	    mode = sc->sc_npmode[NP_IP];
821 	    break;
822 	default:
823 	    mode = NPMODE_PASS;
824 	}
825 
826 	switch (mode) {
827 	case NPMODE_PASS:
828 	    /*
829 	     * This packet can now go on one of the queues to be sent.
830 	     */
831 	    *mpp = m->m_nextpkt;
832 	    m->m_nextpkt = NULL;
833 	    ifq = (m->m_flags & M_HIGHPRI)? &sc->sc_fastq: &sc->sc_if.if_snd;
834 	    if (IF_QFULL(ifq)) {
835 		IF_DROP(ifq);
836 		sc->sc_if.if_oerrors++;
837 		sc->sc_stats.ppp_oerrors++;
838 	    } else
839 		IF_ENQUEUE(ifq, m);
840 	    break;
841 
842 	case NPMODE_DROP:
843 	case NPMODE_ERROR:
844 	    *mpp = m->m_nextpkt;
845 	    m_freem(m);
846 	    break;
847 
848 	case NPMODE_QUEUE:
849 	    mpp = &m->m_nextpkt;
850 	    break;
851 	}
852     }
853     sc->sc_npqtail = mpp;
854 }
855 
856 /*
857  * Transmitter has finished outputting some stuff;
858  * remember to call sc->sc_start later at splsoftnet.
859  */
860 void
861 ppp_restart(sc)
862     struct ppp_softc *sc;
863 {
864     int s = splimp();
865 
866     sc->sc_flags &= ~SC_TBUSY;
867     schednetisr(NETISR_PPP);
868     splx(s);
869 }
870 
871 /*
872  * Get a packet to send.  This procedure is intended to be called at
873  * splsoftnet, since it may involve time-consuming operations such as
874  * applying VJ compression, packet compression, address/control and/or
875  * protocol field compression to the packet.
876  */
877 struct mbuf *
878 ppp_dequeue(sc)
879     struct ppp_softc *sc;
880 {
881     struct mbuf *m, *mp;
882     u_char *cp;
883     int address, control, protocol;
884 
885     /*
886      * Grab a packet to send: first try the fast queue, then the
887      * normal queue.
888      */
889     IF_DEQUEUE(&sc->sc_fastq, m);
890     if (m == NULL)
891 	IF_DEQUEUE(&sc->sc_if.if_snd, m);
892     if (m == NULL)
893 	return NULL;
894 
895     ++sc->sc_stats.ppp_opackets;
896 
897     /*
898      * Extract the ppp header of the new packet.
899      * The ppp header will be in one mbuf.
900      */
901     cp = mtod(m, u_char *);
902     address = PPP_ADDRESS(cp);
903     control = PPP_CONTROL(cp);
904     protocol = PPP_PROTOCOL(cp);
905 
906     switch (protocol) {
907     case PPP_IP:
908 #ifdef VJC
909 	/*
910 	 * If the packet is a TCP/IP packet, see if we can compress it.
911 	 */
912 	if ((sc->sc_flags & SC_COMP_TCP) && sc->sc_comp != NULL) {
913 	    struct ip *ip;
914 	    int type;
915 
916 	    mp = m;
917 	    ip = (struct ip *) (cp + PPP_HDRLEN);
918 	    if (mp->m_len <= PPP_HDRLEN) {
919 		mp = mp->m_next;
920 		if (mp == NULL)
921 		    break;
922 		ip = mtod(mp, struct ip *);
923 	    }
924 	    /* this code assumes the IP/TCP header is in one non-shared mbuf */
925 	    if (ip->ip_p == IPPROTO_TCP) {
926 		type = sl_compress_tcp(mp, ip, sc->sc_comp,
927 				       !(sc->sc_flags & SC_NO_TCP_CCID));
928 		switch (type) {
929 		case TYPE_UNCOMPRESSED_TCP:
930 		    protocol = PPP_VJC_UNCOMP;
931 		    break;
932 		case TYPE_COMPRESSED_TCP:
933 		    protocol = PPP_VJC_COMP;
934 		    cp = mtod(m, u_char *);
935 		    cp[0] = address;	/* header has moved */
936 		    cp[1] = control;
937 		    cp[2] = 0;
938 		    break;
939 		}
940 		cp[3] = protocol;	/* update protocol in PPP header */
941 	    }
942 	}
943 #endif	/* VJC */
944 	break;
945 
946 #ifdef PPP_COMPRESS
947     case PPP_CCP:
948 	ppp_ccp(sc, m, 0);
949 	break;
950 #endif	/* PPP_COMPRESS */
951     }
952 
953 #ifdef PPP_COMPRESS
954     if (protocol != PPP_LCP && protocol != PPP_CCP
955 	&& sc->sc_xc_state && (sc->sc_flags & SC_COMP_RUN)) {
956 	struct mbuf *mcomp = NULL;
957 	int slen, clen;
958 
959 	slen = 0;
960 	for (mp = m; mp != NULL; mp = mp->m_next)
961 	    slen += mp->m_len;
962 	clen = (*sc->sc_xcomp->compress)
963 	    (sc->sc_xc_state, &mcomp, m, slen, sc->sc_if.if_mtu + PPP_HDRLEN);
964 	if (mcomp != NULL) {
965 	    if (sc->sc_flags & SC_CCP_UP) {
966 		/* Send the compressed packet instead of the original. */
967 		m_freem(m);
968 		m = mcomp;
969 		cp = mtod(m, u_char *);
970 		protocol = cp[3];
971 	    } else {
972 		/* Can't transmit compressed packets until CCP is up. */
973 		m_freem(mcomp);
974 	    }
975 	}
976     }
977 #endif	/* PPP_COMPRESS */
978 
979     /*
980      * Compress the address/control and protocol, if possible.
981      */
982     if (sc->sc_flags & SC_COMP_AC && address == PPP_ALLSTATIONS &&
983 	control == PPP_UI && protocol != PPP_ALLSTATIONS &&
984 	protocol != PPP_LCP) {
985 	/* can compress address/control */
986 	m->m_data += 2;
987 	m->m_len -= 2;
988     }
989     if (sc->sc_flags & SC_COMP_PROT && protocol < 0xFF) {
990 	/* can compress protocol */
991 	if (mtod(m, u_char *) == cp) {
992 	    cp[2] = cp[1];	/* move address/control up */
993 	    cp[1] = cp[0];
994 	}
995 	++m->m_data;
996 	--m->m_len;
997     }
998 
999     return m;
1000 }
1001 
1002 /*
1003  * Software interrupt routine, called at splsoftnet.
1004  */
1005 void
1006 pppintr()
1007 {
1008     struct ppp_softc *sc;
1009     int i, s, s2;
1010     struct mbuf *m;
1011 
1012     sc = ppp_softc;
1013     s = splsoftnet();
1014     for (i = 0; i < NPPP; ++i, ++sc) {
1015 	if (!(sc->sc_flags & SC_TBUSY)
1016 	    && (sc->sc_if.if_snd.ifq_head || sc->sc_fastq.ifq_head)) {
1017 	    s2 = splimp();
1018 	    sc->sc_flags |= SC_TBUSY;
1019 	    splx(s2);
1020 	    (*sc->sc_start)(sc);
1021 	}
1022 	for (;;) {
1023 	    s2 = splimp();
1024 	    IF_DEQUEUE(&sc->sc_rawq, m);
1025 	    splx(s2);
1026 	    if (m == NULL)
1027 		break;
1028 	    ppp_inproc(sc, m);
1029 	}
1030     }
1031     splx(s);
1032 }
1033 
1034 #ifdef PPP_COMPRESS
1035 /*
1036  * Handle a CCP packet.  `rcvd' is 1 if the packet was received,
1037  * 0 if it is about to be transmitted.
1038  */
1039 static void
1040 ppp_ccp(sc, m, rcvd)
1041     struct ppp_softc *sc;
1042     struct mbuf *m;
1043     int rcvd;
1044 {
1045     u_char *dp, *ep;
1046     struct mbuf *mp;
1047     int slen, s;
1048 
1049     /*
1050      * Get a pointer to the data after the PPP header.
1051      */
1052     if (m->m_len <= PPP_HDRLEN) {
1053 	mp = m->m_next;
1054 	if (mp == NULL)
1055 	    return;
1056 	dp = (mp != NULL)? mtod(mp, u_char *): NULL;
1057     } else {
1058 	mp = m;
1059 	dp = mtod(mp, u_char *) + PPP_HDRLEN;
1060     }
1061 
1062     ep = mtod(mp, u_char *) + mp->m_len;
1063     if (dp + CCP_HDRLEN > ep)
1064 	return;
1065     slen = CCP_LENGTH(dp);
1066     if (dp + slen > ep) {
1067 	if (sc->sc_flags & SC_DEBUG)
1068 	    printf("if_ppp/ccp: not enough data in mbuf (%p+%x > %p+%x)\n",
1069 		dp, slen, mtod(mp, u_char *), mp->m_len);
1070 	return;
1071     }
1072 
1073     switch (CCP_CODE(dp)) {
1074     case CCP_CONFREQ:
1075     case CCP_TERMREQ:
1076     case CCP_TERMACK:
1077 	/* CCP must be going down - disable compression */
1078 	if (sc->sc_flags & SC_CCP_UP) {
1079 	    s = splimp();
1080 	    sc->sc_flags &= ~(SC_CCP_UP | SC_COMP_RUN | SC_DECOMP_RUN);
1081 	    splx(s);
1082 	}
1083 	break;
1084 
1085     case CCP_CONFACK:
1086 	if (sc->sc_flags & SC_CCP_OPEN && !(sc->sc_flags & SC_CCP_UP)
1087 	    && slen >= CCP_HDRLEN + CCP_OPT_MINLEN
1088 	    && slen >= CCP_OPT_LENGTH(dp + CCP_HDRLEN) + CCP_HDRLEN) {
1089 	    if (!rcvd) {
1090 		/* we're agreeing to send compressed packets. */
1091 		if (sc->sc_xc_state != NULL
1092 		    && (*sc->sc_xcomp->comp_init)
1093 			(sc->sc_xc_state, dp + CCP_HDRLEN, slen - CCP_HDRLEN,
1094 			 sc->sc_unit, 0, sc->sc_flags & SC_DEBUG)) {
1095 		    s = splimp();
1096 		    sc->sc_flags |= SC_COMP_RUN;
1097 		    splx(s);
1098 		}
1099 	    } else {
1100 		/* peer is agreeing to send compressed packets. */
1101 		if (sc->sc_rc_state != NULL
1102 		    && (*sc->sc_rcomp->decomp_init)
1103 			(sc->sc_rc_state, dp + CCP_HDRLEN, slen - CCP_HDRLEN,
1104 			 sc->sc_unit, 0, sc->sc_mru,
1105 			 sc->sc_flags & SC_DEBUG)) {
1106 		    s = splimp();
1107 		    sc->sc_flags |= SC_DECOMP_RUN;
1108 		    sc->sc_flags &= ~(SC_DC_ERROR | SC_DC_FERROR);
1109 		    splx(s);
1110 		}
1111 	    }
1112 	}
1113 	break;
1114 
1115     case CCP_RESETACK:
1116 	if (sc->sc_flags & SC_CCP_UP) {
1117 	    if (!rcvd) {
1118 		if (sc->sc_xc_state && (sc->sc_flags & SC_COMP_RUN))
1119 		    (*sc->sc_xcomp->comp_reset)(sc->sc_xc_state);
1120 	    } else {
1121 		if (sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)) {
1122 		    (*sc->sc_rcomp->decomp_reset)(sc->sc_rc_state);
1123 		    s = splimp();
1124 		    sc->sc_flags &= ~SC_DC_ERROR;
1125 		    splx(s);
1126 		}
1127 	    }
1128 	}
1129 	break;
1130     }
1131 }
1132 
1133 /*
1134  * CCP is down; free (de)compressor state if necessary.
1135  */
1136 static void
1137 ppp_ccp_closed(sc)
1138     struct ppp_softc *sc;
1139 {
1140     if (sc->sc_xc_state) {
1141 	(*sc->sc_xcomp->comp_free)(sc->sc_xc_state);
1142 	sc->sc_xc_state = NULL;
1143     }
1144     if (sc->sc_rc_state) {
1145 	(*sc->sc_rcomp->decomp_free)(sc->sc_rc_state);
1146 	sc->sc_rc_state = NULL;
1147     }
1148 }
1149 #endif /* PPP_COMPRESS */
1150 
1151 /*
1152  * PPP packet input routine.
1153  * The caller has checked and removed the FCS and has inserted
1154  * the address/control bytes and the protocol high byte if they
1155  * were omitted.
1156  */
1157 void
1158 ppppktin(sc, m, lost)
1159     struct ppp_softc *sc;
1160     struct mbuf *m;
1161     int lost;
1162 {
1163     int s = splimp();
1164 
1165     if (lost)
1166 	m->m_flags |= M_ERRMARK;
1167     IF_ENQUEUE(&sc->sc_rawq, m);
1168     schednetisr(NETISR_PPP);
1169     splx(s);
1170 }
1171 
1172 /*
1173  * Process a received PPP packet, doing decompression as necessary.
1174  * Should be called at splsoftnet.
1175  */
1176 #define COMPTYPE(proto)	((proto) == PPP_VJC_COMP? TYPE_COMPRESSED_TCP: \
1177 			 TYPE_UNCOMPRESSED_TCP)
1178 
1179 static void
1180 ppp_inproc(sc, m)
1181     struct ppp_softc *sc;
1182     struct mbuf *m;
1183 {
1184     struct ifnet *ifp = &sc->sc_if;
1185     struct ifqueue *inq;
1186     int s, ilen, xlen, proto, rv;
1187     u_char *cp, adrs, ctrl;
1188     struct mbuf *mp, *dmp = NULL;
1189     u_char *iphdr;
1190     u_int hlen;
1191 
1192     sc->sc_stats.ppp_ipackets++;
1193 
1194     if (sc->sc_flags & SC_LOG_INPKT) {
1195 	ilen = 0;
1196 	for (mp = m; mp != NULL; mp = mp->m_next)
1197 	    ilen += mp->m_len;
1198 	printf("%s: got %d bytes\n", ifp->if_xname, ilen);
1199 	pppdumpm(m);
1200     }
1201 
1202     cp = mtod(m, u_char *);
1203     adrs = PPP_ADDRESS(cp);
1204     ctrl = PPP_CONTROL(cp);
1205     proto = PPP_PROTOCOL(cp);
1206 
1207     if (m->m_flags & M_ERRMARK) {
1208 	m->m_flags &= ~M_ERRMARK;
1209 	s = splimp();
1210 	sc->sc_flags |= SC_VJ_RESET;
1211 	splx(s);
1212     }
1213 
1214 #ifdef PPP_COMPRESS
1215     /*
1216      * Decompress this packet if necessary, update the receiver's
1217      * dictionary, or take appropriate action on a CCP packet.
1218      */
1219     if (proto == PPP_COMP && sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)
1220 	&& !(sc->sc_flags & SC_DC_ERROR) && !(sc->sc_flags & SC_DC_FERROR)) {
1221 	/* decompress this packet */
1222 	rv = (*sc->sc_rcomp->decompress)(sc->sc_rc_state, m, &dmp);
1223 	if (rv == DECOMP_OK) {
1224 	    m_freem(m);
1225 	    if (dmp == NULL) {
1226 		/* no error, but no decompressed packet produced */
1227 		return;
1228 	    }
1229 	    m = dmp;
1230 	    cp = mtod(m, u_char *);
1231 	    proto = PPP_PROTOCOL(cp);
1232 
1233 	} else {
1234 	    /*
1235 	     * An error has occurred in decompression.
1236 	     * Pass the compressed packet up to pppd, which may take
1237 	     * CCP down or issue a Reset-Req.
1238 	     */
1239 	    if (sc->sc_flags & SC_DEBUG)
1240 		printf("%s: decompress failed %d\n", ifp->if_xname, rv);
1241 	    s = splimp();
1242 	    sc->sc_flags |= SC_VJ_RESET;
1243 	    if (rv == DECOMP_ERROR)
1244 		sc->sc_flags |= SC_DC_ERROR;
1245 	    else
1246 		sc->sc_flags |= SC_DC_FERROR;
1247 	    splx(s);
1248 	}
1249 
1250     } else {
1251 	if (sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)) {
1252 	    (*sc->sc_rcomp->incomp)(sc->sc_rc_state, m);
1253 	}
1254 	if (proto == PPP_CCP) {
1255 	    ppp_ccp(sc, m, 1);
1256 	}
1257     }
1258 #endif
1259 
1260     ilen = 0;
1261     for (mp = m; mp != NULL; mp = mp->m_next)
1262 	ilen += mp->m_len;
1263 
1264 #ifdef VJC
1265     if (sc->sc_flags & SC_VJ_RESET) {
1266 	/*
1267 	 * If we've missed a packet, we must toss subsequent compressed
1268 	 * packets which don't have an explicit connection ID.
1269 	 */
1270 	if (sc->sc_comp)
1271 	    sl_uncompress_tcp(NULL, 0, TYPE_ERROR, sc->sc_comp);
1272 	s = splimp();
1273 	sc->sc_flags &= ~SC_VJ_RESET;
1274 	splx(s);
1275     }
1276 
1277     /*
1278      * See if we have a VJ-compressed packet to uncompress.
1279      */
1280     if (proto == PPP_VJC_COMP) {
1281 	if ((sc->sc_flags & SC_REJ_COMP_TCP) || sc->sc_comp == 0)
1282 	    goto bad;
1283 
1284 	xlen = sl_uncompress_tcp_core(cp + PPP_HDRLEN, m->m_len - PPP_HDRLEN,
1285 				      ilen - PPP_HDRLEN, TYPE_COMPRESSED_TCP,
1286 				      sc->sc_comp, &iphdr, &hlen);
1287 
1288 	if (xlen <= 0) {
1289 	    if (sc->sc_flags & SC_DEBUG)
1290 		printf("%s: VJ uncompress failed on type comp\n",
1291 		    ifp->if_xname);
1292 	    goto bad;
1293 	}
1294 
1295 	/* Copy the PPP and IP headers into a new mbuf. */
1296 	MGETHDR(mp, M_DONTWAIT, MT_DATA);
1297 	if (mp == NULL)
1298 	    goto bad;
1299 	mp->m_len = 0;
1300 	mp->m_next = NULL;
1301 	if (hlen + PPP_HDRLEN > MHLEN) {
1302 	    MCLGET(mp, M_DONTWAIT);
1303 	    if (M_TRAILINGSPACE(mp) < hlen + PPP_HDRLEN) {
1304 		m_freem(mp);
1305 		goto bad;	/* lose if big headers and no clusters */
1306 	    }
1307 	}
1308 	cp = mtod(mp, u_char *);
1309 	cp[0] = adrs;
1310 	cp[1] = ctrl;
1311 	cp[2] = 0;
1312 	cp[3] = PPP_IP;
1313 	proto = PPP_IP;
1314 	bcopy(iphdr, cp + PPP_HDRLEN, hlen);
1315 	mp->m_len = hlen + PPP_HDRLEN;
1316 
1317 	/*
1318 	 * Trim the PPP and VJ headers off the old mbuf
1319 	 * and stick the new and old mbufs together.
1320 	 */
1321 	m->m_data += PPP_HDRLEN + xlen;
1322 	m->m_len -= PPP_HDRLEN + xlen;
1323 	if (m->m_len <= M_TRAILINGSPACE(mp)) {
1324 	    bcopy(mtod(m, u_char *), mtod(mp, u_char *) + mp->m_len, m->m_len);
1325 	    mp->m_len += m->m_len;
1326 	    MFREE(m, mp->m_next);
1327 	} else
1328 	    mp->m_next = m;
1329 	m = mp;
1330 	ilen += hlen - xlen;
1331 
1332     } else if (proto == PPP_VJC_UNCOMP) {
1333 	if ((sc->sc_flags & SC_REJ_COMP_TCP) || sc->sc_comp == 0)
1334 	    goto bad;
1335 
1336 	xlen = sl_uncompress_tcp_core(cp + PPP_HDRLEN, m->m_len - PPP_HDRLEN,
1337 				      ilen - PPP_HDRLEN, TYPE_UNCOMPRESSED_TCP,
1338 				      sc->sc_comp, &iphdr, &hlen);
1339 
1340 	if (xlen < 0) {
1341 	    if (sc->sc_flags & SC_DEBUG)
1342 		printf("%s: VJ uncompress failed on type uncomp\n",
1343 		    ifp->if_xname);
1344 	    goto bad;
1345 	}
1346 
1347 	proto = PPP_IP;
1348 	cp[3] = PPP_IP;
1349     }
1350 #endif /* VJC */
1351 
1352     /*
1353      * If the packet will fit in a header mbuf, don't waste a
1354      * whole cluster on it.
1355      */
1356     if (ilen <= MHLEN && M_IS_CLUSTER(m)) {
1357 	MGETHDR(mp, M_DONTWAIT, MT_DATA);
1358 	if (mp != NULL) {
1359 	    m_copydata(m, 0, ilen, mtod(mp, caddr_t));
1360 	    m_freem(m);
1361 	    m = mp;
1362 	    m->m_len = ilen;
1363 	}
1364     }
1365     m->m_pkthdr.len = ilen;
1366     m->m_pkthdr.rcvif = ifp;
1367 
1368     if ((proto & 0x8000) == 0) {
1369 #ifdef PPP_FILTER
1370 	/*
1371 	 * See whether we want to pass this packet, and
1372 	 * if it counts as link activity.
1373 	 */
1374 	adrs = *mtod(m, u_char *);	/* save address field */
1375 	*mtod(m, u_char *) = 0;		/* indicate inbound */
1376 	if (sc->sc_pass_filt.bf_insns != 0
1377 	    && bpf_filter(sc->sc_pass_filt.bf_insns, (u_char *) m,
1378 			  ilen, 0) == 0) {
1379 	    /* drop this packet */
1380 	    m_freem(m);
1381 	    return;
1382 	}
1383 	if (sc->sc_active_filt.bf_insns == 0
1384 	    || bpf_filter(sc->sc_active_filt.bf_insns, (u_char *) m, ilen, 0))
1385 	    sc->sc_last_recv = time.tv_sec;
1386 
1387 	*mtod(m, u_char *) = adrs;
1388 #else
1389 	/*
1390 	 * Record the time that we received this packet.
1391 	 */
1392 	sc->sc_last_recv = time.tv_sec;
1393 #endif /* PPP_FILTER */
1394     }
1395 
1396 #if NBPFILTER > 0
1397     /* See if bpf wants to look at the packet. */
1398     if (sc->sc_bpf)
1399 	bpf_mtap(sc->sc_bpf, m);
1400 #endif
1401 
1402     rv = 0;
1403     switch (proto) {
1404 #ifdef INET
1405     case PPP_IP:
1406 	/*
1407 	 * IP packet - take off the ppp header and pass it up to IP.
1408 	 */
1409 	if ((ifp->if_flags & IFF_UP) == 0
1410 	    || sc->sc_npmode[NP_IP] != NPMODE_PASS) {
1411 	    /* interface is down - drop the packet. */
1412 	    m_freem(m);
1413 	    return;
1414 	}
1415 	m->m_pkthdr.len -= PPP_HDRLEN;
1416 	m->m_data += PPP_HDRLEN;
1417 	m->m_len -= PPP_HDRLEN;
1418 	schednetisr(NETISR_IP);
1419 	inq = &ipintrq;
1420 	break;
1421 #endif
1422 
1423     default:
1424 	/*
1425 	 * Some other protocol - place on input queue for read().
1426 	 */
1427 	inq = &sc->sc_inq;
1428 	rv = 1;
1429 	break;
1430     }
1431 
1432     /*
1433      * Put the packet on the appropriate input queue.
1434      */
1435     s = splimp();
1436     if (IF_QFULL(inq)) {
1437 	IF_DROP(inq);
1438 	splx(s);
1439 	if (sc->sc_flags & SC_DEBUG)
1440 	    printf("%s: input queue full\n", ifp->if_xname);
1441 	ifp->if_iqdrops++;
1442 	goto bad;
1443     }
1444     IF_ENQUEUE(inq, m);
1445     splx(s);
1446     ifp->if_ipackets++;
1447     ifp->if_ibytes += ilen;
1448     ifp->if_lastchange = time;
1449 
1450     if (rv)
1451 	(*sc->sc_ctlp)(sc);
1452 
1453     return;
1454 
1455  bad:
1456     m_freem(m);
1457     sc->sc_if.if_ierrors++;
1458     sc->sc_stats.ppp_ierrors++;
1459 }
1460 
1461 #define MAX_DUMP_BYTES	128
1462 
1463 static void
1464 pppdumpm(m0)
1465     struct mbuf *m0;
1466 {
1467     char buf[3*MAX_DUMP_BYTES+4];
1468     char *bp = buf;
1469     struct mbuf *m;
1470     static char digits[] = "0123456789abcdef";
1471 
1472     for (m = m0; m; m = m->m_next) {
1473 	int l = m->m_len;
1474 	u_char *rptr = (u_char *)m->m_data;
1475 
1476 	while (l--) {
1477 	    if (bp > buf + sizeof(buf) - 4)
1478 		goto done;
1479 	    *bp++ = digits[*rptr >> 4]; /* convert byte to ascii hex */
1480 	    *bp++ = digits[*rptr++ & 0xf];
1481 	}
1482 
1483 	if (m->m_next) {
1484 	    if (bp > buf + sizeof(buf) - 3)
1485 		goto done;
1486 	    *bp++ = '|';
1487 	} else
1488 	    *bp++ = ' ';
1489     }
1490 done:
1491     if (m)
1492 	*bp++ = '>';
1493     *bp = 0;
1494     printf("%s\n", buf);
1495 }
1496 
1497 #endif	/* NPPP > 0 */
1498