$NetBSD: patch-ap,v 1.1.1.1 1999/10/08 04:34:43 dbj Exp $

--- /dev/null	Sat Sep 18 04:00:15 1999
+++ netbsd-1.4/if_ppp.c	Sat Sep 18 04:06:21 1999
@@ -0,0 +1,1616 @@
+/*	NetBSD: if_ppp.c,v 1.55 1999/07/30 10:35:38 itojun Exp 	*/
+/*	Id: if_ppp.c,v 1.6 1997/03/04 03:33:00 paulus Exp 	*/
+
+/*
+ * if_ppp.c - Point-to-Point Protocol (PPP) Asynchronous driver.
+ *
+ * Copyright (c) 1989 Carnegie Mellon University.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that the above copyright notice and this paragraph are
+ * duplicated in all such forms and that any documentation,
+ * advertising materials, and other materials related to such
+ * distribution and use acknowledge that the software was developed
+ * by Carnegie Mellon University.  The name of the
+ * University may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * Drew D. Perkins
+ * Carnegie Mellon University
+ * 4910 Forbes Ave.
+ * Pittsburgh, PA 15213
+ * (412) 268-8576
+ * ddp@andrew.cmu.edu
+ *
+ * Based on:
+ *	@(#)if_sl.c	7.6.1.2 (Berkeley) 2/15/89
+ *
+ * Copyright (c) 1987 Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that the above copyright notice and this paragraph are
+ * duplicated in all such forms and that any documentation,
+ * advertising materials, and other materials related to such
+ * distribution and use acknowledge that the software was developed
+ * by the University of California, Berkeley.  The name of the
+ * University may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * Serial Line interface
+ *
+ * Rick Adams
+ * Center for Seismic Studies
+ * 1300 N 17th Street, Suite 1450
+ * Arlington, Virginia 22209
+ * (703)276-7900
+ * rick@seismo.ARPA
+ * seismo!rick
+ *
+ * Pounded on heavily by Chris Torek (chris@mimsy.umd.edu, umcp-cs!chris).
+ * Converted to 4.3BSD Beta by Chris Torek.
+ * Other changes made at Berkeley, based in part on code by Kirk Smith.
+ *
+ * Converted to 4.3BSD+ 386BSD by Brad Parker (brad@cayman.com)
+ * Added VJ tcp header compression; more unified ioctls
+ *
+ * Extensively modified by Paul Mackerras (paulus@cs.anu.edu.au).
+ * Cleaned up a lot of the mbuf-related code to fix bugs that
+ * caused system crashes and packet corruption.  Changed pppstart
+ * so that it doesn't just give up with a collision if the whole
+ * packet doesn't fit in the output ring buffer.
+ *
+ * Added priority queueing for interactive IP packets, following
+ * the model of if_sl.c, plus hooks for bpf.
+ * Paul Mackerras (paulus@cs.anu.edu.au).
+ */
+
+/* from if_sl.c,v 1.11 84/10/04 12:54:47 rick Exp */
+/* from NetBSD: if_ppp.c,v 1.15.2.2 1994/07/28 05:17:58 cgd Exp */
+
+#include "ppp.h"
+#if NPPP > 0
+
+#define VJC
+#define PPP_COMPRESS
+
+#include "opt_inet.h"
+#include "opt_gateway.h"
+#include "opt_ppp.h"
+
+#include <sys/param.h>
+#include <sys/proc.h>
+#include <sys/mbuf.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <sys/kernel.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/malloc.h>
+
+#include <net/if.h>
+#include <net/if_types.h>
+#include <net/netisr.h>
+#include <net/route.h>
+#ifdef PPP_FILTER
+#include <net/bpf.h>
+#endif
+
+#ifdef INET
+#include <netinet/in.h>
+#include <netinet/in_systm.h>
+#include <netinet/in_var.h>
+#include <netinet/ip.h>
+#else
+#ifdef _KERNEL
+#ifdef VJC
+#error ppp device with VJC assumes INET
+#endif
+#endif
+#endif
+
+#include "bpfilter.h"
+#if NBPFILTER > 0
+#include <sys/time.h>
+#include <net/bpf.h>
+#endif
+
+#if defined(PPP_FILTER) || NBPFILTER > 0
+#include <net/slip.h>
+#endif
+
+#ifdef VJC
+#include <net/slcompress.h>
+#endif
+
+#include <net/ppp_defs.h>
+#include <net/if_ppp.h>
+#include <net/if_pppvar.h>
+#include <machine/cpu.h>
+
+#ifdef PPP_COMPRESS
+#define PACKETPTR	struct mbuf *
+#include <net/ppp-comp.h>
+#endif
+
+static int	pppsioctl __P((struct ifnet *, u_long, caddr_t));
+static void	ppp_requeue __P((struct ppp_softc *));
+static void	ppp_ccp __P((struct ppp_softc *, struct mbuf *m, int rcvd));
+static void	ppp_ccp_closed __P((struct ppp_softc *));
+static void	ppp_inproc __P((struct ppp_softc *, struct mbuf *));
+static void	pppdumpm __P((struct mbuf *m0));
+
+/*
+ * Some useful mbuf macros not in mbuf.h.
+ */
+#define M_IS_CLUSTER(m)	((m)->m_flags & M_EXT)
+
+#define M_DATASTART(m)	\
+	(M_IS_CLUSTER(m) ? (m)->m_ext.ext_buf : \
+	    (m)->m_flags & M_PKTHDR ? (m)->m_pktdat : (m)->m_dat)
+
+#define M_DATASIZE(m)	\
+	(M_IS_CLUSTER(m) ? (m)->m_ext.ext_size : \
+	    (m)->m_flags & M_PKTHDR ? MHLEN: MLEN)
+
+/*
+ * We define two link layer specific mbuf flags, to mark high-priority
+ * packets for output, and received packets following lost/corrupted
+ * packets.
+ */
+#define	M_HIGHPRI	M_LINK0	/* output packet for sc_fastq */
+#define	M_ERRMARK	M_LINK1	/* rx packet following lost/corrupted pkt */
+
+#ifdef PPP_COMPRESS
+/*
+ * List of compressors we know about.
+ * We leave some space so maybe we can modload compressors.
+ */
+
+extern struct compressor ppp_bsd_compress;
+extern struct compressor ppp_deflate, ppp_deflate_draft;
+
+struct compressor *ppp_compressors[8] = {
+#if DO_BSD_COMPRESS && defined(PPP_BSDCOMP)
+    &ppp_bsd_compress,
+#endif
+#if DO_DEFLATE && defined(PPP_DEFLATE)
+    &ppp_deflate,
+    &ppp_deflate_draft,
+#endif
+    NULL
+};
+#endif /* PPP_COMPRESS */
+
+
+/*
+ * Called from boot code to establish ppp interfaces.
+ */
+void
+pppattach()
+{
+    register struct ppp_softc *sc;
+    register int i = 0;
+
+    for (sc = ppp_softc; i < NPPP; sc++) {
+	sc->sc_unit = i;	/* XXX */
+	sprintf(sc->sc_if.if_xname, "ppp%d", i++);
+	sc->sc_if.if_softc = sc;
+	sc->sc_if.if_mtu = PPP_MTU;
+	sc->sc_if.if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
+	sc->sc_if.if_type = IFT_PPP;
+	sc->sc_if.if_hdrlen = PPP_HDRLEN;
+	sc->sc_if.if_ioctl = pppsioctl;
+	sc->sc_if.if_output = pppoutput;
+	sc->sc_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
+	sc->sc_inq.ifq_maxlen = IFQ_MAXLEN;
+	sc->sc_fastq.ifq_maxlen = IFQ_MAXLEN;
+	sc->sc_rawq.ifq_maxlen = IFQ_MAXLEN;
+	if_attach(&sc->sc_if);
+#if NBPFILTER > 0
+	bpfattach(&sc->sc_bpf, &sc->sc_if, DLT_NULL, 0);
+#endif
+    }
+}
+
+/*
+ * Allocate a ppp interface unit and initialize it.
+ */
+struct ppp_softc *
+pppalloc(pid)
+    pid_t pid;
+{
+    int nppp, i;
+    struct ppp_softc *sc;
+
+    for (nppp = 0, sc = ppp_softc; nppp < NPPP; nppp++, sc++)
+	if (sc->sc_xfer == pid) {
+	    sc->sc_xfer = 0;
+	    return sc;
+	}
+    for (nppp = 0, sc = ppp_softc; nppp < NPPP; nppp++, sc++)
+	if (sc->sc_devp == NULL)
+	    break;
+    if (nppp >= NPPP)
+	return NULL;
+
+    sc->sc_flags = 0;
+    sc->sc_mru = PPP_MRU;
+    sc->sc_relinq = NULL;
+    bzero((char *)&sc->sc_stats, sizeof(sc->sc_stats));
+#ifdef VJC
+    MALLOC(sc->sc_comp, struct slcompress *, sizeof(struct slcompress),
+	   M_DEVBUF, M_NOWAIT);
+    if (sc->sc_comp)
+	sl_compress_init(sc->sc_comp);
+#endif
+#ifdef PPP_COMPRESS
+    sc->sc_xc_state = NULL;
+    sc->sc_rc_state = NULL;
+#endif /* PPP_COMPRESS */
+    for (i = 0; i < NUM_NP; ++i)
+	sc->sc_npmode[i] = NPMODE_ERROR;
+    sc->sc_npqueue = NULL;
+    sc->sc_npqtail = &sc->sc_npqueue;
+    sc->sc_last_sent = sc->sc_last_recv = time.tv_sec;
+
+    return sc;
+}
+
+/*
+ * Deallocate a ppp unit.  Must be called at splsoftnet or higher.
+ */
+void
+pppdealloc(sc)
+    struct ppp_softc *sc;
+{
+    struct mbuf *m;
+
+    if_down(&sc->sc_if);
+    sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
+    sc->sc_devp = NULL;
+    sc->sc_xfer = 0;
+    for (;;) {
+	IF_DEQUEUE(&sc->sc_rawq, m);
+	if (m == NULL)
+	    break;
+	m_freem(m);
+    }
+    for (;;) {
+	IF_DEQUEUE(&sc->sc_inq, m);
+	if (m == NULL)
+	    break;
+	m_freem(m);
+    }
+    for (;;) {
+	IF_DEQUEUE(&sc->sc_fastq, m);
+	if (m == NULL)
+	    break;
+	m_freem(m);
+    }
+    while ((m = sc->sc_npqueue) != NULL) {
+	sc->sc_npqueue = m->m_nextpkt;
+	m_freem(m);
+    }
+    if (sc->sc_togo != NULL) {
+	m_freem(sc->sc_togo);
+	sc->sc_togo = NULL;
+    }
+#ifdef PPP_COMPRESS
+    ppp_ccp_closed(sc);
+    sc->sc_xc_state = NULL;
+    sc->sc_rc_state = NULL;
+#endif /* PPP_COMPRESS */
+#ifdef PPP_FILTER
+    if (sc->sc_pass_filt_in.bf_insns != 0) {
+	FREE(sc->sc_pass_filt_in.bf_insns, M_DEVBUF);
+	sc->sc_pass_filt_in.bf_insns = 0;
+	sc->sc_pass_filt_in.bf_len = 0;
+    }
+    if (sc->sc_pass_filt_out.bf_insns != 0) {
+	FREE(sc->sc_pass_filt_out.bf_insns, M_DEVBUF);
+	sc->sc_pass_filt_out.bf_insns = 0;
+	sc->sc_pass_filt_out.bf_len = 0;
+    }
+    if (sc->sc_active_filt_in.bf_insns != 0) {
+	FREE(sc->sc_active_filt_in.bf_insns, M_DEVBUF);
+	sc->sc_active_filt_in.bf_insns = 0;
+	sc->sc_active_filt_in.bf_len = 0;
+    }
+    if (sc->sc_active_filt_out.bf_insns != 0) {
+	FREE(sc->sc_active_filt_out.bf_insns, M_DEVBUF);
+	sc->sc_active_filt_out.bf_insns = 0;
+	sc->sc_active_filt_out.bf_len = 0;
+    }
+#endif /* PPP_FILTER */
+#ifdef VJC
+    if (sc->sc_comp != 0) {
+	FREE(sc->sc_comp, M_DEVBUF);
+	sc->sc_comp = 0;
+    }
+#endif
+}
+
+/*
+ * Ioctl routine for generic ppp devices.
+ */
+int
+pppioctl(sc, cmd, data, flag, p)
+    struct ppp_softc *sc;
+    u_long cmd;
+    caddr_t data;
+    int flag;
+    struct proc *p;
+{
+    int s, error, flags, mru, nb, npx;
+    struct ppp_option_data *odp;
+    struct compressor **cp;
+    struct npioctl *npi;
+    time_t t;
+#ifdef PPP_FILTER
+    struct bpf_program *bp, *nbp;
+    struct bpf_insn *newcode, *oldcode;
+    int newcodelen;
+#endif /* PPP_FILTER */
+#ifdef	PPP_COMPRESS
+    u_char ccp_option[CCP_MAX_OPTION_LENGTH];
+#endif
+
+    switch (cmd) {
+    case FIONREAD:
+	*(int *)data = sc->sc_inq.ifq_len;
+	break;
+
+    case PPPIOCGUNIT:
+	*(int *)data = sc->sc_unit;	/* XXX */
+	break;
+
+    case PPPIOCGFLAGS:
+	*(u_int *)data = sc->sc_flags;
+	break;
+
+    case PPPIOCSFLAGS:
+	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
+	    return (error);
+	flags = *(int *)data & SC_MASK;
+	s = splsoftnet();
+#ifdef PPP_COMPRESS
+	if (sc->sc_flags & SC_CCP_OPEN && !(flags & SC_CCP_OPEN))
+	    ppp_ccp_closed(sc);
+#endif
+	splimp();
+	sc->sc_flags = (sc->sc_flags & ~SC_MASK) | flags;
+	splx(s);
+	break;
+
+    case PPPIOCSMRU:
+	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
+	    return (error);
+	mru = *(int *)data;
+	if (mru >= PPP_MRU && mru <= PPP_MAXMRU)
+	    sc->sc_mru = mru;
+	break;
+
+    case PPPIOCGMRU:
+	*(int *)data = sc->sc_mru;
+	break;
+
+#ifdef VJC
+    case PPPIOCSMAXCID:
+	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
+	    return (error);
+	if (sc->sc_comp) {
+	    s = splsoftnet();
+	    sl_compress_setup(sc->sc_comp, *(int *)data);
+	    splx(s);
+	}
+	break;
+#endif
+
+    case PPPIOCXFERUNIT:
+	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
+	    return (error);
+	sc->sc_xfer = p->p_pid;
+	break;
+
+#ifdef PPP_COMPRESS
+    case PPPIOCSCOMPRESS:
+	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
+	    return (error);
+	odp = (struct ppp_option_data *) data;
+	nb = odp->length;
+	if (nb > sizeof(ccp_option))
+	    nb = sizeof(ccp_option);
+	if ((error = copyin(odp->ptr, ccp_option, nb)) != 0)
+	    return (error);
+	if (ccp_option[1] < 2)	/* preliminary check on the length byte */
+	    return (EINVAL);
+	for (cp = ppp_compressors; *cp != NULL; ++cp)
+	    if ((*cp)->compress_proto == ccp_option[0]) {
+		/*
+		 * Found a handler for the protocol - try to allocate
+		 * a compressor or decompressor.
+		 */
+		error = 0;
+		if (odp->transmit) {
+		    s = splsoftnet();
+		    if (sc->sc_xc_state != NULL)
+			(*sc->sc_xcomp->comp_free)(sc->sc_xc_state);
+		    sc->sc_xcomp = *cp;
+		    sc->sc_xc_state = (*cp)->comp_alloc(ccp_option, nb);
+		    if (sc->sc_xc_state == NULL) {
+			if (sc->sc_flags & SC_DEBUG)
+			    printf("%s: comp_alloc failed\n",
+				sc->sc_if.if_xname);
+			error = ENOBUFS;
+		    }
+		    splimp();
+		    sc->sc_flags &= ~SC_COMP_RUN;
+		    splx(s);
+		} else {
+		    s = splsoftnet();
+		    if (sc->sc_rc_state != NULL)
+			(*sc->sc_rcomp->decomp_free)(sc->sc_rc_state);
+		    sc->sc_rcomp = *cp;
+		    sc->sc_rc_state = (*cp)->decomp_alloc(ccp_option, nb);
+		    if (sc->sc_rc_state == NULL) {
+			if (sc->sc_flags & SC_DEBUG)
+			    printf("%s: decomp_alloc failed\n",
+				sc->sc_if.if_xname);
+			error = ENOBUFS;
+		    }
+		    splimp();
+		    sc->sc_flags &= ~SC_DECOMP_RUN;
+		    splx(s);
+		}
+		return (error);
+	    }
+	if (sc->sc_flags & SC_DEBUG)
+	    printf("%s: no compressor for [%x %x %x], %x\n",
+		sc->sc_if.if_xname, ccp_option[0], ccp_option[1],
+		ccp_option[2], nb);
+	return (EINVAL);	/* no handler found */
+#endif /* PPP_COMPRESS */
+
+    case PPPIOCGNPMODE:
+    case PPPIOCSNPMODE:
+	npi = (struct npioctl *) data;
+	switch (npi->protocol) {
+	case PPP_IP:
+	    npx = NP_IP;
+	    break;
+	case PPP_IPV6:
+	    npx = NP_IPV6;
+	    break;
+	default:
+	    return EINVAL;
+	}
+	if (cmd == PPPIOCGNPMODE) {
+	    npi->mode = sc->sc_npmode[npx];
+	} else {
+	    if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
+		return (error);
+	    if (npi->mode != sc->sc_npmode[npx]) {
+		s = splimp();
+		sc->sc_npmode[npx] = npi->mode;
+		if (npi->mode != NPMODE_QUEUE) {
+		    ppp_requeue(sc);
+		    ppp_restart(sc);
+		}
+		splx(s);
+	    }
+	}
+	break;
+
+    case PPPIOCGIDLE:
+	s = splsoftnet();
+	t = time.tv_sec;
+	((struct ppp_idle *)data)->xmit_idle = t - sc->sc_last_sent;
+	((struct ppp_idle *)data)->recv_idle = t - sc->sc_last_recv;
+	splx(s);
+	break;
+
+#ifdef PPP_FILTER
+    case PPPIOCSPASS:
+    case PPPIOCSACTIVE:
+	/* These are no longer supported. */
+	return EOPNOTSUPP;
+
+    case PPPIOCSIPASS:
+    case PPPIOCSOPASS:
+    case PPPIOCSIACTIVE:
+    case PPPIOCSOACTIVE:
+	nbp = (struct bpf_program *) data;
+	if ((unsigned) nbp->bf_len > BPF_MAXINSNS)
+	    return EINVAL;
+	newcodelen = nbp->bf_len * sizeof(struct bpf_insn);
+	if (newcodelen != 0) {
+	    newcode = malloc(newcodelen, M_DEVBUF, M_WAITOK);
+	    /* WAITOK -- malloc() never fails. */
+	    if ((error = copyin((caddr_t)nbp->bf_insns, (caddr_t)newcode,
+			       newcodelen)) != 0) {
+		free(newcode, M_DEVBUF);
+		return error;
+	    }
+	    if (!bpf_validate(newcode, nbp->bf_len)) {
+		free(newcode, M_DEVBUF);
+		return EINVAL;
+	    }
+	} else
+	    newcode = 0;
+	switch (cmd) {
+	case PPPIOCSIPASS:
+	    bp = &sc->sc_pass_filt_in;
+	    break;
+
+	case PPPIOCSOPASS:
+	    bp = &sc->sc_pass_filt_out;
+	    break;
+
+	case PPPIOCSIACTIVE:
+	    bp = &sc->sc_active_filt_in;
+	    break;
+
+	case PPPIOCSOACTIVE:
+	    bp = &sc->sc_active_filt_out;
+	    break;
+	}
+	oldcode = bp->bf_insns;
+	s = splimp();
+	bp->bf_len = nbp->bf_len;
+	bp->bf_insns = newcode;
+	splx(s);
+	if (oldcode != 0)
+	    free(oldcode, M_DEVBUF);
+	break;
+#endif /* PPP_FILTER */
+
+    default:
+	return (-1);
+    }
+    return (0);
+}
+
+/*
+ * Process an ioctl request to the ppp network interface.
+ */
+static int
+pppsioctl(ifp, cmd, data)
+    register struct ifnet *ifp;
+    u_long cmd;
+    caddr_t data;
+{
+    register struct proc *p = curproc;	/* XXX */
+    register struct ppp_softc *sc = ifp->if_softc;
+    register struct ifaddr *ifa = (struct ifaddr *)data;
+    register struct ifreq *ifr = (struct ifreq *)data;
+    struct ppp_stats *psp;
+#ifdef	PPP_COMPRESS
+    struct ppp_comp_stats *pcp;
+#endif
+    int s = splimp(), error = 0;
+
+    switch (cmd) {
+    case SIOCSIFFLAGS:
+	if ((ifp->if_flags & IFF_RUNNING) == 0)
+	    ifp->if_flags &= ~IFF_UP;
+	break;
+
+    case SIOCSIFADDR:
+	switch (ifa->ifa_addr->sa_family) {
+#ifdef INET
+	case AF_INET:
+	    break;
+#endif
+#ifdef INET6
+	case AF_INET6:
+	    break;
+#endif
+	default:
+	    error = EAFNOSUPPORT;
+	    break;
+	}
+	break;
+
+    case SIOCSIFDSTADDR:
+	switch (ifa->ifa_addr->sa_family) {
+#ifdef INET
+	case AF_INET:
+	    break;
+#endif
+#ifdef INET6
+	case AF_INET6:
+	    break;
+#endif
+	default:
+	    error = EAFNOSUPPORT;
+	    break;
+	}
+	break;
+
+    case SIOCSIFMTU:
+	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
+	    break;
+	sc->sc_if.if_mtu = ifr->ifr_mtu;
+	break;
+
+    case SIOCGIFMTU:
+	ifr->ifr_mtu = sc->sc_if.if_mtu;
+	break;
+
+    case SIOCADDMULTI:
+    case SIOCDELMULTI:
+	if (ifr == 0) {
+	    error = EAFNOSUPPORT;
+	    break;
+	}
+	switch(ifr->ifr_addr.sa_family) {
+#ifdef INET
+	case AF_INET:
+	    break;
+#endif
+#ifdef INET6
+	case AF_INET6:
+	    break;
+#endif
+	default:
+	    error = EAFNOSUPPORT;
+	    break;
+	}
+	break;
+
+    case SIOCGPPPSTATS:
+	psp = &((struct ifpppstatsreq *) data)->stats;
+	bzero(psp, sizeof(*psp));
+	psp->p = sc->sc_stats;
+#if defined(VJC) && !defined(SL_NO_STATS)
+	if (sc->sc_comp) {
+	    psp->vj.vjs_packets = sc->sc_comp->sls_packets;
+	    psp->vj.vjs_compressed = sc->sc_comp->sls_compressed;
+	    psp->vj.vjs_searches = sc->sc_comp->sls_searches;
+	    psp->vj.vjs_misses = sc->sc_comp->sls_misses;
+	    psp->vj.vjs_uncompressedin = sc->sc_comp->sls_uncompressedin;
+	    psp->vj.vjs_compressedin = sc->sc_comp->sls_compressedin;
+	    psp->vj.vjs_errorin = sc->sc_comp->sls_errorin;
+	    psp->vj.vjs_tossed = sc->sc_comp->sls_tossed;
+	}
+#endif /* VJC */
+	break;
+
+#ifdef PPP_COMPRESS
+    case SIOCGPPPCSTATS:
+	pcp = &((struct ifpppcstatsreq *) data)->stats;
+	bzero(pcp, sizeof(*pcp));
+	if (sc->sc_xc_state != NULL)
+	    (*sc->sc_xcomp->comp_stat)(sc->sc_xc_state, &pcp->c);
+	if (sc->sc_rc_state != NULL)
+	    (*sc->sc_rcomp->decomp_stat)(sc->sc_rc_state, &pcp->d);
+	break;
+#endif /* PPP_COMPRESS */
+
+    default:
+	error = EINVAL;
+    }
+    splx(s);
+    return (error);
+}
+
+/*
+ * Queue a packet.  Start transmission if not active.
+ * Packet is placed in Information field of PPP frame.
+ */
+int
+pppoutput(ifp, m0, dst, rtp)
+    struct ifnet *ifp;
+    struct mbuf *m0;
+    struct sockaddr *dst;
+    struct rtentry *rtp;
+{
+    register struct ppp_softc *sc = ifp->if_softc;
+    int protocol, address, control;
+    u_char *cp;
+    int s, error;
+    struct ip *ip;
+    struct ifqueue *ifq;
+    enum NPmode mode;
+    int len;
+    struct mbuf *m;
+
+    if (sc->sc_devp == NULL || (ifp->if_flags & IFF_RUNNING) == 0
+	|| ((ifp->if_flags & IFF_UP) == 0 && dst->sa_family != AF_UNSPEC)) {
+	error = ENETDOWN;	/* sort of */
+	goto bad;
+    }
+
+    /*
+     * Compute PPP header.
+     */
+    m0->m_flags &= ~M_HIGHPRI;
+    switch (dst->sa_family) {
+#ifdef INET
+    case AF_INET:
+	address = PPP_ALLSTATIONS;
+	control = PPP_UI;
+	protocol = PPP_IP;
+	mode = sc->sc_npmode[NP_IP];
+
+	/*
+	 * If this packet has the "low delay" bit set in the IP header,
+	 * put it on the fastq instead.
+	 */
+	ip = mtod(m0, struct ip *);
+	if (ip->ip_tos & IPTOS_LOWDELAY)
+	    m0->m_flags |= M_HIGHPRI;
+	break;
+#endif
+#ifdef INET6
+    case AF_INET6:
+	address = PPP_ALLSTATIONS;	/*XXX*/
+	control = PPP_UI;		/*XXX*/
+	protocol = PPP_IPV6;
+	mode = sc->sc_npmode[NP_IPV6];
+
+#if 0	/* XXX flowinfo/traffic class, maybe? */
+	/*
+	 * If this packet has the "low delay" bit set in the IP header,
+	 * put it on the fastq instead.
+	 */
+	ip = mtod(m0, struct ip *);
+	if (ip->ip_tos & IPTOS_LOWDELAY)
+	    m0->m_flags |= M_HIGHPRI;
+	break;
+#endif
+#endif
+    case AF_UNSPEC:
+	address = PPP_ADDRESS(dst->sa_data);
+	control = PPP_CONTROL(dst->sa_data);
+	protocol = PPP_PROTOCOL(dst->sa_data);
+	mode = NPMODE_PASS;
+	break;
+    default:
+	printf("%s: af%d not supported\n", ifp->if_xname, dst->sa_family);
+	error = EAFNOSUPPORT;
+	goto bad;
+    }
+
+    /*
+     * Drop this packet, or return an error, if necessary.
+     */
+    if (mode == NPMODE_ERROR) {
+	error = ENETDOWN;
+	goto bad;
+    }
+    if (mode == NPMODE_DROP) {
+	error = 0;
+	goto bad;
+    }
+
+    /*
+     * Add PPP header.  If no space in first mbuf, allocate another.
+     * (This assumes M_LEADINGSPACE is always 0 for a cluster mbuf.)
+     */
+    if (M_LEADINGSPACE(m0) < PPP_HDRLEN) {
+	m0 = m_prepend(m0, PPP_HDRLEN, M_DONTWAIT);
+	if (m0 == 0) {
+	    error = ENOBUFS;
+	    goto bad;
+	}
+	m0->m_len = 0;
+    } else
+	m0->m_data -= PPP_HDRLEN;
+
+    cp = mtod(m0, u_char *);
+    *cp++ = address;
+    *cp++ = control;
+    *cp++ = protocol >> 8;
+    *cp++ = protocol & 0xff;
+    m0->m_len += PPP_HDRLEN;
+
+    len = 0;
+    for (m = m0; m != 0; m = m->m_next)
+	len += m->m_len;
+
+    if (sc->sc_flags & SC_LOG_OUTPKT) {
+	printf("%s output: ", ifp->if_xname);
+	pppdumpm(m0);
+    }
+
+    if ((protocol & 0x8000) == 0) {
+#ifdef PPP_FILTER
+	/*
+	 * Apply the pass and active filters to the packet,
+	 * but only if it is a data packet.
+	 */
+	if (sc->sc_pass_filt_out.bf_insns != 0
+	    && bpf_filter(sc->sc_pass_filt_out.bf_insns, (u_char *) m0,
+			  len, 0) == 0) {
+	    error = 0;		/* drop this packet */
+	    goto bad;
+	}
+
+	/*
+	 * Update the time we sent the most recent packet.
+	 */
+	if (sc->sc_active_filt_out.bf_insns == 0
+	    || bpf_filter(sc->sc_active_filt_out.bf_insns, (u_char *) m0,
+	    		  len, 0))
+	    sc->sc_last_sent = time.tv_sec;
+#else
+	/*
+	 * Update the time we sent the most recent packet.
+	 */
+	sc->sc_last_sent = time.tv_sec;
+#endif /* PPP_FILTER */
+    }
+
+#if NBPFILTER > 0
+    /*
+     * See if bpf wants to look at the packet.
+     */
+    if (sc->sc_bpf)
+	bpf_mtap(sc->sc_bpf, m0);
+#endif
+
+    /*
+     * Put the packet on the appropriate queue.
+     */
+    s = splimp();
+    if (mode == NPMODE_QUEUE) {
+	/* XXX we should limit the number of packets on this queue */
+	*sc->sc_npqtail = m0;
+	m0->m_nextpkt = NULL;
+	sc->sc_npqtail = &m0->m_nextpkt;
+    } else {
+	ifq = (m0->m_flags & M_HIGHPRI)? &sc->sc_fastq: &ifp->if_snd;
+	if (IF_QFULL(ifq) && dst->sa_family != AF_UNSPEC) {
+	    IF_DROP(ifq);
+	    splx(s);
+	    sc->sc_if.if_oerrors++;
+	    sc->sc_stats.ppp_oerrors++;
+	    error = ENOBUFS;
+	    goto bad;
+	}
+	IF_ENQUEUE(ifq, m0);
+	ppp_restart(sc);
+    }
+    ifp->if_lastchange = time;
+    ifp->if_opackets++;
+    ifp->if_obytes += len;
+
+    splx(s);
+    return (0);
+
+bad:
+    m_freem(m0);
+    return (error);
+}
+
+/*
+ * After a change in the NPmode for some NP, move packets from the
+ * npqueue to the send queue or the fast queue as appropriate.
+ * Should be called at splimp, since we muck with the queues.
+ */
+static void
+ppp_requeue(sc)
+    struct ppp_softc *sc;
+{
+    struct mbuf *m, **mpp;
+    struct ifqueue *ifq;
+    enum NPmode mode;
+
+    for (mpp = &sc->sc_npqueue; (m = *mpp) != NULL; ) {
+	switch (PPP_PROTOCOL(mtod(m, u_char *))) {
+	case PPP_IP:
+	    mode = sc->sc_npmode[NP_IP];
+	    break;
+	case PPP_IPV6:
+	    mode = sc->sc_npmode[NP_IPV6];
+	    break;
+	default:
+	    mode = NPMODE_PASS;
+	}
+
+	switch (mode) {
+	case NPMODE_PASS:
+	    /*
+	     * This packet can now go on one of the queues to be sent.
+	     */
+	    *mpp = m->m_nextpkt;
+	    m->m_nextpkt = NULL;
+	    ifq = (m->m_flags & M_HIGHPRI)? &sc->sc_fastq: &sc->sc_if.if_snd;
+	    if (IF_QFULL(ifq)) {
+		IF_DROP(ifq);
+		sc->sc_if.if_oerrors++;
+		sc->sc_stats.ppp_oerrors++;
+	    } else
+		IF_ENQUEUE(ifq, m);
+	    break;
+
+	case NPMODE_DROP:
+	case NPMODE_ERROR:
+	    *mpp = m->m_nextpkt;
+	    m_freem(m);
+	    break;
+
+	case NPMODE_QUEUE:
+	    mpp = &m->m_nextpkt;
+	    break;
+	}
+    }
+    sc->sc_npqtail = mpp;
+}
+
+/*
+ * Transmitter has finished outputting some stuff;
+ * remember to call sc->sc_start later at splsoftnet.
+ */
+void
+ppp_restart(sc)
+    struct ppp_softc *sc;
+{
+    int s = splimp();
+
+    sc->sc_flags &= ~SC_TBUSY;
+    schednetisr(NETISR_PPP);
+    splx(s);
+}
+
+/*
+ * Get a packet to send.  This procedure is intended to be called at
+ * splsoftnet, since it may involve time-consuming operations such as
+ * applying VJ compression, packet compression, address/control and/or
+ * protocol field compression to the packet.
+ */
+struct mbuf *
+ppp_dequeue(sc)
+    struct ppp_softc *sc;
+{
+    struct mbuf *m, *mp;
+    u_char *cp;
+    int address, control, protocol;
+    int s;
+
+    /*
+     * Grab a packet to send: first try the fast queue, then the
+     * normal queue.
+     */
+    s = splimp();    
+    IF_DEQUEUE(&sc->sc_fastq, m);
+    if (m == NULL)
+	IF_DEQUEUE(&sc->sc_if.if_snd, m);
+    splx(s);
+    
+    if (m == NULL)
+	return NULL;
+
+    ++sc->sc_stats.ppp_opackets;
+
+    /*
+     * Extract the ppp header of the new packet.
+     * The ppp header will be in one mbuf.
+     */
+    cp = mtod(m, u_char *);
+    address = PPP_ADDRESS(cp);
+    control = PPP_CONTROL(cp);
+    protocol = PPP_PROTOCOL(cp);
+
+    switch (protocol) {
+    case PPP_IP:
+#ifdef VJC
+	/*
+	 * If the packet is a TCP/IP packet, see if we can compress it.
+	 */
+	if ((sc->sc_flags & SC_COMP_TCP) && sc->sc_comp != NULL) {
+	    struct ip *ip;
+	    int type;
+
+	    mp = m;
+	    ip = (struct ip *) (cp + PPP_HDRLEN);
+	    if (mp->m_len <= PPP_HDRLEN) {
+		mp = mp->m_next;
+		if (mp == NULL)
+		    break;
+		ip = mtod(mp, struct ip *);
+	    }
+	    /* this code assumes the IP/TCP header is in one non-shared mbuf */
+	    if (ip->ip_p == IPPROTO_TCP) {
+		type = sl_compress_tcp(mp, ip, sc->sc_comp,
+				       !(sc->sc_flags & SC_NO_TCP_CCID));
+		switch (type) {
+		case TYPE_UNCOMPRESSED_TCP:
+		    protocol = PPP_VJC_UNCOMP;
+		    break;
+		case TYPE_COMPRESSED_TCP:
+		    protocol = PPP_VJC_COMP;
+		    cp = mtod(m, u_char *);
+		    cp[0] = address;	/* header has moved */
+		    cp[1] = control;
+		    cp[2] = 0;
+		    break;
+		}
+		cp[3] = protocol;	/* update protocol in PPP header */
+	    }
+	}
+#endif	/* VJC */
+	break;
+
+#ifdef PPP_COMPRESS
+    case PPP_CCP:
+	ppp_ccp(sc, m, 0);
+	break;
+#endif	/* PPP_COMPRESS */
+    }
+
+#ifdef PPP_COMPRESS
+    if (protocol != PPP_LCP && protocol != PPP_CCP
+	&& sc->sc_xc_state && (sc->sc_flags & SC_COMP_RUN)) {
+	struct mbuf *mcomp = NULL;
+	int slen, clen;
+
+	slen = 0;
+	for (mp = m; mp != NULL; mp = mp->m_next)
+	    slen += mp->m_len;
+	clen = (*sc->sc_xcomp->compress)
+	    (sc->sc_xc_state, &mcomp, m, slen, sc->sc_if.if_mtu + PPP_HDRLEN);
+	if (mcomp != NULL) {
+	    if (sc->sc_flags & SC_CCP_UP) {
+		/* Send the compressed packet instead of the original. */
+		m_freem(m);
+		m = mcomp;
+		cp = mtod(m, u_char *);
+		protocol = cp[3];
+	    } else {
+		/* Can't transmit compressed packets until CCP is up. */
+		m_freem(mcomp);
+	    }
+	}
+    }
+#endif	/* PPP_COMPRESS */
+
+    /*
+     * Compress the address/control and protocol, if possible.
+     */
+    if (sc->sc_flags & SC_COMP_AC && address == PPP_ALLSTATIONS &&
+	control == PPP_UI && protocol != PPP_ALLSTATIONS &&
+	protocol != PPP_LCP) {
+	/* can compress address/control */
+	m->m_data += 2;
+	m->m_len -= 2;
+    }
+    if (sc->sc_flags & SC_COMP_PROT && protocol < 0xFF) {
+	/* can compress protocol */
+	if (mtod(m, u_char *) == cp) {
+	    cp[2] = cp[1];	/* move address/control up */
+	    cp[1] = cp[0];
+	}
+	++m->m_data;
+	--m->m_len;
+    }
+
+    return m;
+}
+
+/*
+ * Software interrupt routine, called at splsoftnet.
+ */
+void
+pppintr()
+{
+    struct ppp_softc *sc;
+    int i, s, s2;
+    struct mbuf *m;
+
+    sc = ppp_softc;
+    s = splsoftnet();
+    for (i = 0; i < NPPP; ++i, ++sc) {
+	if (!(sc->sc_flags & SC_TBUSY)
+	    && (sc->sc_if.if_snd.ifq_head || sc->sc_fastq.ifq_head
+		|| sc->sc_outm)) {
+	    s2 = splimp();
+	    sc->sc_flags |= SC_TBUSY;
+	    splx(s2);
+	    (*sc->sc_start)(sc);
+	}
+	for (;;) {
+	    s2 = splimp();
+	    IF_DEQUEUE(&sc->sc_rawq, m);
+	    splx(s2);
+	    if (m == NULL)
+		break;
+	    ppp_inproc(sc, m);
+	}
+    }
+    splx(s);
+}
+
+#ifdef PPP_COMPRESS
+/*
+ * Handle a CCP packet.  `rcvd' is 1 if the packet was received,
+ * 0 if it is about to be transmitted.
+ */
+static void
+ppp_ccp(sc, m, rcvd)
+    struct ppp_softc *sc;
+    struct mbuf *m;
+    int rcvd;
+{
+    u_char *dp, *ep;
+    struct mbuf *mp;
+    int slen, s;
+
+    /*
+     * Get a pointer to the data after the PPP header.
+     */
+    if (m->m_len <= PPP_HDRLEN) {
+	mp = m->m_next;
+	if (mp == NULL)
+	    return;
+	dp = (mp != NULL)? mtod(mp, u_char *): NULL;
+    } else {
+	mp = m;
+	dp = mtod(mp, u_char *) + PPP_HDRLEN;
+    }
+
+    ep = mtod(mp, u_char *) + mp->m_len;
+    if (dp + CCP_HDRLEN > ep)
+	return;
+    slen = CCP_LENGTH(dp);
+    if (dp + slen > ep) {
+	if (sc->sc_flags & SC_DEBUG)
+	    printf("if_ppp/ccp: not enough data in mbuf (%p+%x > %p+%x)\n",
+		dp, slen, mtod(mp, u_char *), mp->m_len);
+	return;
+    }
+
+    switch (CCP_CODE(dp)) {
+    case CCP_CONFREQ:
+    case CCP_TERMREQ:
+    case CCP_TERMACK:
+	/* CCP must be going down - disable compression */
+	if (sc->sc_flags & SC_CCP_UP) {
+	    s = splimp();
+	    sc->sc_flags &= ~(SC_CCP_UP | SC_COMP_RUN | SC_DECOMP_RUN);
+	    splx(s);
+	}
+	break;
+
+    case CCP_CONFACK:
+	if (sc->sc_flags & SC_CCP_OPEN && !(sc->sc_flags & SC_CCP_UP)
+	    && slen >= CCP_HDRLEN + CCP_OPT_MINLEN
+	    && slen >= CCP_OPT_LENGTH(dp + CCP_HDRLEN) + CCP_HDRLEN) {
+	    if (!rcvd) {
+		/* we're agreeing to send compressed packets. */
+		if (sc->sc_xc_state != NULL
+		    && (*sc->sc_xcomp->comp_init)
+			(sc->sc_xc_state, dp + CCP_HDRLEN, slen - CCP_HDRLEN,
+			 sc->sc_unit, 0, sc->sc_flags & SC_DEBUG)) {
+		    s = splimp();
+		    sc->sc_flags |= SC_COMP_RUN;
+		    splx(s);
+		}
+	    } else {
+		/* peer is agreeing to send compressed packets. */
+		if (sc->sc_rc_state != NULL
+		    && (*sc->sc_rcomp->decomp_init)
+			(sc->sc_rc_state, dp + CCP_HDRLEN, slen - CCP_HDRLEN,
+			 sc->sc_unit, 0, sc->sc_mru,
+			 sc->sc_flags & SC_DEBUG)) {
+		    s = splimp();
+		    sc->sc_flags |= SC_DECOMP_RUN;
+		    sc->sc_flags &= ~(SC_DC_ERROR | SC_DC_FERROR);
+		    splx(s);
+		}
+	    }
+	}
+	break;
+
+    case CCP_RESETACK:
+	if (sc->sc_flags & SC_CCP_UP) {
+	    if (!rcvd) {
+		if (sc->sc_xc_state && (sc->sc_flags & SC_COMP_RUN))
+		    (*sc->sc_xcomp->comp_reset)(sc->sc_xc_state);
+	    } else {
+		if (sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)) {
+		    (*sc->sc_rcomp->decomp_reset)(sc->sc_rc_state);
+		    s = splimp();
+		    sc->sc_flags &= ~SC_DC_ERROR;
+		    splx(s);
+		}
+	    }
+	}
+	break;
+    }
+}
+
+/*
+ * CCP is down; free (de)compressor state if necessary.
+ */
+static void
+ppp_ccp_closed(sc)
+    struct ppp_softc *sc;
+{
+    if (sc->sc_xc_state) {
+	(*sc->sc_xcomp->comp_free)(sc->sc_xc_state);
+	sc->sc_xc_state = NULL;
+    }
+    if (sc->sc_rc_state) {
+	(*sc->sc_rcomp->decomp_free)(sc->sc_rc_state);
+	sc->sc_rc_state = NULL;
+    }
+}
+#endif /* PPP_COMPRESS */
+
+/*
+ * PPP packet input routine.
+ * The caller has checked and removed the FCS and has inserted
+ * the address/control bytes and the protocol high byte if they
+ * were omitted.
+ */
+void
+ppppktin(sc, m, lost)
+    struct ppp_softc *sc;
+    struct mbuf *m;
+    int lost;
+{
+    int s = splimp();
+
+    if (lost)
+	m->m_flags |= M_ERRMARK;
+    IF_ENQUEUE(&sc->sc_rawq, m);
+    schednetisr(NETISR_PPP);
+    splx(s);
+}
+
+/*
+ * Process a received PPP packet, doing decompression as necessary.
+ * Should be called at splsoftnet.
+ */
+#define COMPTYPE(proto)	((proto) == PPP_VJC_COMP? TYPE_COMPRESSED_TCP: \
+			 TYPE_UNCOMPRESSED_TCP)
+
+static void
+ppp_inproc(sc, m)
+    struct ppp_softc *sc;
+    struct mbuf *m;
+{
+    struct ifnet *ifp = &sc->sc_if;
+    struct ifqueue *inq;
+    int s, ilen, xlen, proto, rv;
+    u_char *cp, adrs, ctrl;
+    struct mbuf *mp, *dmp = NULL;
+    u_char *iphdr;
+    u_int hlen;
+
+    sc->sc_stats.ppp_ipackets++;
+
+    if (sc->sc_flags & SC_LOG_INPKT) {
+	ilen = 0;
+	for (mp = m; mp != NULL; mp = mp->m_next)
+	    ilen += mp->m_len;
+	printf("%s: got %d bytes\n", ifp->if_xname, ilen);
+	pppdumpm(m);
+    }
+
+    cp = mtod(m, u_char *);
+    adrs = PPP_ADDRESS(cp);
+    ctrl = PPP_CONTROL(cp);
+    proto = PPP_PROTOCOL(cp);
+
+    if (m->m_flags & M_ERRMARK) {
+	m->m_flags &= ~M_ERRMARK;
+	s = splimp();
+	sc->sc_flags |= SC_VJ_RESET;
+	splx(s);
+    }
+
+#ifdef PPP_COMPRESS
+    /*
+     * Decompress this packet if necessary, update the receiver's
+     * dictionary, or take appropriate action on a CCP packet.
+     */
+    if (proto == PPP_COMP && sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)
+	&& !(sc->sc_flags & SC_DC_ERROR) && !(sc->sc_flags & SC_DC_FERROR)) {
+	/* decompress this packet */
+	rv = (*sc->sc_rcomp->decompress)(sc->sc_rc_state, m, &dmp);
+	if (rv == DECOMP_OK) {
+	    m_freem(m);
+	    if (dmp == NULL) {
+		/* no error, but no decompressed packet produced */
+		return;
+	    }
+	    m = dmp;
+	    cp = mtod(m, u_char *);
+	    proto = PPP_PROTOCOL(cp);
+
+	} else {
+	    /*
+	     * An error has occurred in decompression.
+	     * Pass the compressed packet up to pppd, which may take
+	     * CCP down or issue a Reset-Req.
+	     */
+	    if (sc->sc_flags & SC_DEBUG)
+		printf("%s: decompress failed %d\n", ifp->if_xname, rv);
+	    s = splimp();
+	    sc->sc_flags |= SC_VJ_RESET;
+	    if (rv == DECOMP_ERROR)
+		sc->sc_flags |= SC_DC_ERROR;
+	    else
+		sc->sc_flags |= SC_DC_FERROR;
+	    splx(s);
+	}
+
+    } else {
+	if (sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)) {
+	    (*sc->sc_rcomp->incomp)(sc->sc_rc_state, m);
+	}
+	if (proto == PPP_CCP) {
+	    ppp_ccp(sc, m, 1);
+	}
+    }
+#endif
+
+    ilen = 0;
+    for (mp = m; mp != NULL; mp = mp->m_next)
+	ilen += mp->m_len;
+
+#ifdef VJC
+    if (sc->sc_flags & SC_VJ_RESET) {
+	/*
+	 * If we've missed a packet, we must toss subsequent compressed
+	 * packets which don't have an explicit connection ID.
+	 */
+	if (sc->sc_comp)
+	    sl_uncompress_tcp(NULL, 0, TYPE_ERROR, sc->sc_comp);
+	s = splimp();
+	sc->sc_flags &= ~SC_VJ_RESET;
+	splx(s);
+    }
+
+    /*
+     * See if we have a VJ-compressed packet to uncompress.
+     */
+    if (proto == PPP_VJC_COMP) {
+	if ((sc->sc_flags & SC_REJ_COMP_TCP) || sc->sc_comp == 0)
+	    goto bad;
+
+	xlen = sl_uncompress_tcp_core(cp + PPP_HDRLEN, m->m_len - PPP_HDRLEN,
+				      ilen - PPP_HDRLEN, TYPE_COMPRESSED_TCP,
+				      sc->sc_comp, &iphdr, &hlen);
+
+	if (xlen <= 0) {
+	    if (sc->sc_flags & SC_DEBUG)
+		printf("%s: VJ uncompress failed on type comp\n",
+		    ifp->if_xname);
+	    goto bad;
+	}
+
+	/* Copy the PPP and IP headers into a new mbuf. */
+	MGETHDR(mp, M_DONTWAIT, MT_DATA);
+	if (mp == NULL)
+	    goto bad;
+	mp->m_len = 0;
+	mp->m_next = NULL;
+	if (hlen + PPP_HDRLEN > MHLEN) {
+	    MCLGET(mp, M_DONTWAIT);
+	    if (M_TRAILINGSPACE(mp) < hlen + PPP_HDRLEN) {
+		m_freem(mp);
+		goto bad;	/* lose if big headers and no clusters */
+	    }
+	}
+	cp = mtod(mp, u_char *);
+	cp[0] = adrs;
+	cp[1] = ctrl;
+	cp[2] = 0;
+	cp[3] = PPP_IP;
+	proto = PPP_IP;
+	bcopy(iphdr, cp + PPP_HDRLEN, hlen);
+	mp->m_len = hlen + PPP_HDRLEN;
+
+	/*
+	 * Trim the PPP and VJ headers off the old mbuf
+	 * and stick the new and old mbufs together.
+	 */
+	m->m_data += PPP_HDRLEN + xlen;
+	m->m_len -= PPP_HDRLEN + xlen;
+	if (m->m_len <= M_TRAILINGSPACE(mp)) {
+	    bcopy(mtod(m, u_char *), mtod(mp, u_char *) + mp->m_len, m->m_len);
+	    mp->m_len += m->m_len;
+	    MFREE(m, mp->m_next);
+	} else
+	    mp->m_next = m;
+	m = mp;
+	ilen += hlen - xlen;
+
+    } else if (proto == PPP_VJC_UNCOMP) {
+	if ((sc->sc_flags & SC_REJ_COMP_TCP) || sc->sc_comp == 0)
+	    goto bad;
+
+	xlen = sl_uncompress_tcp_core(cp + PPP_HDRLEN, m->m_len - PPP_HDRLEN,
+				      ilen - PPP_HDRLEN, TYPE_UNCOMPRESSED_TCP,
+				      sc->sc_comp, &iphdr, &hlen);
+
+	if (xlen < 0) {
+	    if (sc->sc_flags & SC_DEBUG)
+		printf("%s: VJ uncompress failed on type uncomp\n",
+		    ifp->if_xname);
+	    goto bad;
+	}
+
+	proto = PPP_IP;
+	cp[3] = PPP_IP;
+    }
+#endif /* VJC */
+
+    /*
+     * If the packet will fit in a header mbuf, don't waste a
+     * whole cluster on it.
+     */
+    if (ilen <= MHLEN && M_IS_CLUSTER(m)) {
+	MGETHDR(mp, M_DONTWAIT, MT_DATA);
+	if (mp != NULL) {
+	    m_copydata(m, 0, ilen, mtod(mp, caddr_t));
+	    m_freem(m);
+	    m = mp;
+	    m->m_len = ilen;
+	}
+    }
+    m->m_pkthdr.len = ilen;
+    m->m_pkthdr.rcvif = ifp;
+
+    if ((proto & 0x8000) == 0) {
+#ifdef PPP_FILTER
+	/*
+	 * See whether we want to pass this packet, and
+	 * if it counts as link activity.
+	 */
+	if (sc->sc_pass_filt_in.bf_insns != 0
+	    && bpf_filter(sc->sc_pass_filt_in.bf_insns, (u_char *) m,
+			  ilen, 0) == 0) {
+	    /* drop this packet */
+	    m_freem(m);
+	    return;
+	}
+	if (sc->sc_active_filt_in.bf_insns == 0
+	    || bpf_filter(sc->sc_active_filt_in.bf_insns, (u_char *) m,
+	    		  ilen, 0))
+	    sc->sc_last_recv = time.tv_sec;
+#else
+	/*
+	 * Record the time that we received this packet.
+	 */
+	sc->sc_last_recv = time.tv_sec;
+#endif /* PPP_FILTER */
+    }
+
+#if NBPFILTER > 0
+    /* See if bpf wants to look at the packet. */
+    if (sc->sc_bpf)
+	bpf_mtap(sc->sc_bpf, m);
+#endif
+
+    rv = 0;
+    switch (proto) {
+#ifdef INET
+    case PPP_IP:
+	/*
+	 * IP packet - take off the ppp header and pass it up to IP.
+	 */
+	if ((ifp->if_flags & IFF_UP) == 0
+	    || sc->sc_npmode[NP_IP] != NPMODE_PASS) {
+	    /* interface is down - drop the packet. */
+	    m_freem(m);
+	    return;
+	}
+	m->m_pkthdr.len -= PPP_HDRLEN;
+	m->m_data += PPP_HDRLEN;
+	m->m_len -= PPP_HDRLEN;
+#ifdef GATEWAY
+	if (ipflow_fastforward(m))
+		return;
+#endif
+	schednetisr(NETISR_IP);
+	inq = &ipintrq;
+	break;
+#endif
+
+#ifdef INET6
+    case PPP_IPV6:
+	/*
+	 * IPv6 packet - take off the ppp header and pass it up to IPv6.
+	 */
+	if ((ifp->if_flags & IFF_UP) == 0
+	    || sc->sc_npmode[NP_IPV6] != NPMODE_PASS) {
+	    /* interface is down - drop the packet. */
+	    m_freem(m);
+	    return;
+	}
+	m->m_pkthdr.len -= PPP_HDRLEN;
+	m->m_data += PPP_HDRLEN;
+	m->m_len -= PPP_HDRLEN;
+	schednetisr(NETISR_IPV6);
+	inq = &ip6intrq;
+	break;
+#endif
+
+    default:
+	/*
+	 * Some other protocol - place on input queue for read().
+	 */
+	inq = &sc->sc_inq;
+	rv = 1;
+	break;
+    }
+
+    /*
+     * Put the packet on the appropriate input queue.
+     */
+    s = splimp();
+    if (IF_QFULL(inq)) {
+	IF_DROP(inq);
+	splx(s);
+	if (sc->sc_flags & SC_DEBUG)
+	    printf("%s: input queue full\n", ifp->if_xname);
+	ifp->if_iqdrops++;
+	goto bad;
+    }
+    IF_ENQUEUE(inq, m);
+    splx(s);
+    ifp->if_ipackets++;
+    ifp->if_ibytes += ilen;
+    ifp->if_lastchange = time;
+
+    if (rv)
+	(*sc->sc_ctlp)(sc);
+
+    return;
+
+ bad:
+    m_freem(m);
+    sc->sc_if.if_ierrors++;
+    sc->sc_stats.ppp_ierrors++;
+}
+
+#define MAX_DUMP_BYTES	128
+
+static void
+pppdumpm(m0)
+    struct mbuf *m0;
+{
+    char buf[3*MAX_DUMP_BYTES+4];
+    char *bp = buf;
+    struct mbuf *m;
+    static char digits[] = "0123456789abcdef";
+
+    for (m = m0; m; m = m->m_next) {
+	int l = m->m_len;
+	u_char *rptr = (u_char *)m->m_data;
+
+	while (l--) {
+	    if (bp > buf + sizeof(buf) - 4)
+		goto done;
+	    *bp++ = digits[*rptr >> 4]; /* convert byte to ascii hex */
+	    *bp++ = digits[*rptr++ & 0xf];
+	}
+
+	if (m->m_next) {
+	    if (bp > buf + sizeof(buf) - 3)
+		goto done;
+	    *bp++ = '|';
+	} else
+	    *bp++ = ' ';
+    }
+done:
+    if (m)
+	*bp++ = '>';
+    *bp = 0;
+    printf("%s\n", buf);
+}
+
+#endif	/* NPPP > 0 */
