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if_ppp.c revision 1.40
      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 (at) 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 (at) seismo.ARPA
     55  * seismo!rick
     56  *
     57  * Pounded on heavily by Chris Torek (chris (at) 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 (at) cayman.com)
     62  * Added VJ tcp header compression; more unified ioctls
     63  *
     64  * Extensively modified by Paul Mackerras (paulus (at) 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 (at) 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