ppp_io.c

eCos/RedBoot for勤研ARM AnywhereII(4510) 含全部源代码

//==========================================================================
//
//      src/ppp_io.c
//
//==========================================================================
// This file is part of eCos, the Embedded Configurable Operating System.
// Portions created by Nick Garnett are
// Copyright (C) 2003, 2004 eCosCentric Ltd.
//####BSDCOPYRIGHTBEGIN####
//
// -------------------------------------------
//
// Portions of this software may have been derived from OpenBSD, 
// FreeBSD or other sources, and are covered by the appropriate
// copyright disclaimers included herein.
//
// -------------------------------------------
//
//####BSDCOPYRIGHTEND####
//==========================================================================

/*
 * ppp_tty.c - Point-to-Point Protocol (PPP) driver for asynchronous
 * 	       tty devices.
 *
 * 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,
 * 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]).
 */

/* $FreeBSD: src/sys/net/ppp_tty.c,v 1.43 2000/01/29 16:56:24 peter Exp $ */

#include <pkgconf/system.h>
#include <pkgconf/net.h>
#include <pkgconf/ppp.h>

#define _KERNEL

#define VJC			/* XXX for ppp_defs.h */

#include <sys/param.h>
#define suser(x) 0
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/uio.h>

#ifdef PPP_FILTER
#include <net/bpf.h>
#endif
#include <cyg/ppp/net/if_ppp.h>
#include <cyg/ppp/net/if_pppvar.h>

//==========================================================================

#ifdef __ECOS

#include "cyg/ppp/ppp_io.h"

//#define db_printf diag_printf
#define db_printf(fmt, ... )

#define spltty(x) splsoftnet(x)

#define ENOIOCTL ENOSYS

#endif

//==========================================================================

static u_short	pppfcs __P((u_short fcs, u_char *cp, int len));
static void	pppasyncstart __P((struct ppp_softc *));
static void	pppasyncctlp __P((struct ppp_softc *));
static void	pppasyncrelinq __P((struct ppp_softc *));
static void	pppasyncsetmtu __P((struct ppp_softc *));
static void	pppgetm __P((struct ppp_softc *sc));
static void	ppplogchar __P((struct ppp_softc *, int));

/* XXX called from if_ppp.c - layering violation */
void		pppasyncattach __P((void *));

//==========================================================================
/*
 * 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)

//==========================================================================
/*
 * Does c need to be escaped?
 */
#define ESCAPE_P(c)	(sc->sc_asyncmap[(c) >> 5] & (1 << ((c) & 0x1F)))

//==========================================================================
/*
 * Procedures for using an async tty interface for PPP.
 */

/* This is a FreeBSD-2.X kernel. */
//#define CCOUNT(q)	((q)->c_cc)
//#define PPP_LOWAT	100	/* Process more output when < LOWAT on queue */
//#define	PPP_HIWAT	400	/* Don't start a new packet if HIWAT on que */


//==========================================================================
/*
 * Line specific open routine for async tty devices.
 * Attach the given tty to the first available ppp unit.
 * Called from device open routine or ttioctl() at >= splsofttty()
 */
/* ARGSUSED */

int
cyg_ppp_pppopen(tp)
    struct tty *tp;
{
    register struct ppp_softc *sc;
    int error, s;

    if ((error = suser(p)) != 0)
	return (error);

    s = spltty();

    if ((sc = pppalloc(0)) == NULL) {
	splx(s);
	return ENXIO;
    }
    
    if (sc->sc_relinq)
	(*sc->sc_relinq)(sc);	/* get previous owner to relinquish the unit */

    sc->sc_ilen = 0;
    sc->sc_m = NULL;
    bzero(sc->sc_asyncmap, sizeof(sc->sc_asyncmap));
    sc->sc_asyncmap[0] = 0xffffffff;
    sc->sc_asyncmap[3] = 0x60000000;
    sc->sc_rasyncmap = 0;
    sc->sc_devp = (void *) tp;
    sc->sc_start = pppasyncstart;
    sc->sc_ctlp = pppasyncctlp;
    sc->sc_relinq = pppasyncrelinq;
    sc->sc_setmtu = pppasyncsetmtu;
    sc->sc_outm = NULL;
    pppgetm(sc);
    sc->sc_if.if_flags |= IFF_RUNNING;
    getmicrotime(&sc->sc_if.if_lastchange);
    tp->t_sc = (caddr_t) sc;
    
    splx(s);

    return (0);
}

//==========================================================================
/*
 * Line specific close routine, called from device close routine
 * and from ttioctl at >= splsofttty().
 * Detach the tty from the ppp unit.
 * Mimics part of ttyclose().
 */

int
cyg_ppp_pppclose(tp, flag)
    struct tty *tp;
    int flag;
{
    register struct ppp_softc *sc;
    int s;

    db_printf("%s called\n", __PRETTY_FUNCTION__);
    s = spltty();

    sc = (struct ppp_softc *) tp->t_sc;
    if (sc != NULL) {
	tp->t_sc = NULL;
	if (tp == (struct tty *) sc->sc_devp) {
	    pppasyncrelinq(sc);
	    pppdealloc(sc);
	}
    }
    splx(s);
    return 0;
}

//==========================================================================
/*
 * Relinquish the interface unit to another device.
 */

static void
pppasyncrelinq(sc)
    struct ppp_softc *sc;
{
    int s;

    s = spltty();
    if (sc->sc_outm) {
	m_freem(sc->sc_outm);
	sc->sc_outm = NULL;
    }
    if (sc->sc_m) {
	m_freem(sc->sc_m);
	sc->sc_m = NULL;
    }
    if (sc->sc_flags & SC_TIMEOUT) {
	sc->sc_flags &= ~SC_TIMEOUT;
    }
    splx(s);
}

//==========================================================================
/*
 * This gets called from the upper layer to notify a mtu change
 */

static void
pppasyncsetmtu(sc)
register struct ppp_softc *sc;
{
    db_printf("%s called\n", __PRETTY_FUNCTION__);
}



//==========================================================================
/*
 * function to check if data is available
 */
 
int
cyg_ppp_pppcheck(tp)
    register struct tty *tp;
{
    register struct ppp_softc *sc = (struct ppp_softc *)tp->t_sc;	
    int status = 0;  
    register int s;    
	
    s = spltty();

    if (tp != (struct tty *) sc->sc_devp ) {
        splx(s);
        return 0;
    }
    if (sc->sc_inq.ifq_head == NULL)
    {
        splx(s);
        return 0;
    }	
	
    // if the queue is not empty
    if ( IF_IS_EMPTY(&sc->sc_inq) == false)
        status = 1;
	
    splx(s);

    return(status);
}


//==========================================================================
/*
 * Line specific (tty) read routine.
 * called at zero spl from the device driver in the response to user-level
 * reads on the tty file descriptor (ie: pppd).
 */

int
cyg_ppp_pppread(tp, uio, flag)
    register struct tty *tp;
    struct uio *uio;
    int flag;
{
    register struct ppp_softc *sc = (struct ppp_softc *)tp->t_sc;
    struct mbuf *m, *m0;
    register int s;
    int error = 0;

    db_printf("%s called\n", __PRETTY_FUNCTION__);

    if (sc == NULL)
	return 0;

    // Look for input. If there is none return EWOULDBLOCK, otherwise
    // dequeue the next packet and return it.
    
    s = spltty();

    if (tp != (struct tty *) sc->sc_devp ) {
        splx(s);
        return 0;
    }
    if (sc->sc_inq.ifq_head == NULL)
    {
        splx(s);
        return EWOULDBLOCK;
    }

    /* Get the packet from the input queue */
    IF_DEQUEUE(&sc->sc_inq, m0);
    splx(s);

 
    for (m = m0; m && uio->uio_resid; m = m->m_next)
    {
	if ((error = uiomove(mtod(m, u_char *), m->m_len, uio)) != 0)
	    break;
    }
    m_freem(m0);
    
    return (error);    
}