if_ppp.c

unix and linux net driver

/*
 * 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
 * [phone]
 * [e-mail]
 *
 * 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
 * [phone]
 * [e-mail]
 * seismo!rick
 *
 * Pounded on heavily by Chris Torek ([e-mail], 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 ([e-mail])
 * Added VJ tcp header compression; more unified ioctls
 *
 * Extensively modified by Paul Mackerras ([e-mail]).
 * 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 ([e-mail]).
 *
 * Ultrix port by Per Sundstrom <[e-mail]>,
 * Robert Olsson <[e-mail]> and Paul Mackerras.
 */

/* $Id: if_ppp.c,v 1.15 1998/03/25 03:11:35 paulus Exp $ */
/* 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 "../h/param.h"
#include "../h/user.h"
#include "../h/proc.h"
#include "../h/mbuf.h"
#include "../h/buf.h"
#include "../h/socket.h"
#include "../h/ioctl.h"
#include "../h/systm.h"
#include "../h/time.h"

#include "../net/net/if.h"
#include "../net/net/netisr.h"
#include "../net/net/route.h"

#if INET
#include "../net/netinet/in.h"
#include "../net/netinet/in_systm.h"
#include "../net/netinet/in_var.h"
#include "../net/netinet/ip.h"
#endif

#ifdef vax
#include "../machine/mtpr.h"
#endif

#ifdef VJC
#include "slcompress.h"
#endif

#include "ppp_defs.h"
#include "if_ppp.h"
#include "if_pppvar.h"

#ifdef PPP_COMPRESS
#define PACKETPTR	struct mbuf *
#include "ppp-comp.h"
#endif

static int	pppsioctl(struct ifnet *, int, caddr_t);
static void	ppp_requeue __P((struct ppp_softc *));
static void	ppp_outpkt __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_off > MMAXOFF)

#define M_TRAILINGSPACE(m) \
	((M_IS_CLUSTER(m) ? (u_int)(m)->m_clptr + M_CLUSTERSZ : MSIZE) \
	 - ((m)->m_off + (m)->m_len))

#define M_OFFSTART(m)	\
	(M_IS_CLUSTER(m) ? (u_int)(m)->m_clptr : MMINOFF)

#define M_DATASIZE(m)	\
	(M_IS_CLUSTER(m) ? M_CLUSTERSZ : MLEN)

/*
 * The following disgusting hack gets around the problem that IP TOS
 * can't be set yet.  We want to put "interactive" traffic on a high
 * priority queue.  To decide if traffic is interactive, we check that
 * a) it is TCP and b) one of its ports is telnet, rlogin or ftp control.
 */
static u_short interactive_ports[8] = {
	0,	513,	0,	0,
	0,	21,	0,	23,
};
#define INTERACTIVE(p) (interactive_ports[(p) & 7] == (p))

#ifdef PPP_COMPRESS
/*
 * List of compressors we know about.
 */

extern struct compressor ppp_bsd_compress;
extern struct compressor ppp_deflate;
extern struct compressor ppp_deflate_draft;

struct compressor *ppp_compressors[] = {
#if DO_BSD_COMPRESS
    &ppp_bsd_compress,
#endif
#if DO_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_if.if_name = "ppp";
	sc->sc_if.if_unit = i++;
	sc->sc_if.if_mtu = PPP_MTU;
	sc->sc_if.if_flags = IFF_POINTOPOINT;
	sc->sc_if.if_type = IFT_PPP;
	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_PPP, PPP_HDRLEN);
#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
    KM_ALLOC(sc->sc_comp, struct slcompress *, sizeof(struct slcompress),
	   KM_DEVBUF, KM_NOARG);
    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 splnet 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_act;
	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 VJC
    if (sc->sc_comp != 0) {
	KM_FREE(sc->sc_comp, KM_DEVBUF);
	sc->sc_comp = 0;
    }
#endif
}

/*
 * Ioctl routine for generic ppp devices.
 */
int
pppioctl(sc, cmd, data, flag)
    struct ppp_softc *sc;
    caddr_t data;
    int cmd, flag;
{
    struct proc *p = u.u_procp;
    int s, error, flags, mru, mtu, nb, npx;
    struct ppp_option_data *odp;
    struct compressor **cp;
    struct npioctl *npi;
    time_t t;
#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_if.if_unit;
	break;

    case PPPIOCGFLAGS:
	*(u_int *)data = sc->sc_flags;
	break;

    case PPPIOCSFLAGS:
	if (!suser())
	    return EPERM;
	flags = *(int *)data & SC_MASK;
	s = splnet();
#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 (!suser())
	    return EPERM;
	mru = *(int *)data;
	if (mru >= PPP_MRU && mru <= PPP_MAXMRU)
	    sc->sc_mru = mru;
	break;

    case PPPIOCGMRU:
	*(int *)data = sc->sc_mru;
	break;

    /*
     * PPPIOC[GS]MTU are implemented here, instead of supporting
     * SIOC[GS]IFMTU in pppsioctl, because under Ultrix, we can't get an
     * interface ioctl through to the interface until it has an IP
     * address set.
     */
    case PPPIOCSMTU:
	if (!suser())
	    return EPERM;
	mtu = *(int *) data;
	if (mtu <= 0 || mtu > PPP_MAXMRU)
	    return EINVAL;
	s = splimp();
	sc->sc_if.if_mtu = mtu;
	splx(s);
	break;

    case PPPIOCGMTU:
	*(int *) data = sc->sc_if.if_mtu;
	break;

#ifdef VJC
    case PPPIOCSMAXCID:
	if (!suser())
	    return EPERM;
	if (sc->sc_comp) {
	    s = splnet();
	    sl_compress_setup(sc->sc_comp, *(int *)data);
	    splx(s);
	}
	break;
#endif

    case PPPIOCXFERUNIT:
	if (!suser())
	    return EPERM;
	sc->sc_xfer = p->p_pid;
	break;

#ifdef PPP_COMPRESS
    case PPPIOCSCOMPRESS:
	if (!suser())
	    return EPERM;
	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 = splnet();
		    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("ppp%d: comp_alloc failed\n",
			       sc->sc_if.if_unit);
			error = ENOBUFS;
		    }
		    splimp();
		    sc->sc_flags &= ~SC_COMP_RUN;
		    splx(s);
		} else {
		    s = splnet();
		    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("ppp%d: decomp_alloc failed\n",
			       sc->sc_if.if_unit);
			error = ENOBUFS;
		    }
		    splimp();
		    sc->sc_flags &= ~SC_DECOMP_RUN;
		    splx(s);
		}
		return (error);
	    }
	if (sc->sc_flags & SC_DEBUG)
	    printf("ppp%d: no compressor for [%x %x %x], %x\n",
		   sc->sc_if.if_unit, 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;
	default:
	    return EINVAL;
	}
	if (cmd == PPPIOCGNPMODE) {
	    npi->mode = sc->sc_npmode[npx];
	} else {