if_ppp.c

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

/*
 * 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]).
 */

/* $Id: if_ppp.c,v 1.5.2.1 2004/01/30 14:43:05 joel 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

#include <termios.h>
#include <rtems/termiostypes.h>
#include <rtems/rtems_bsdnet.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/kernel.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

#if INET
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#endif

#include "bpfilter.h"
#if NBPFILTER > 0
#include <net/bpf.h>
#endif

#ifdef VJC
#include <net/pppcompress.h>
#endif

#include <net/ppp_defs.h>
#include <net/if_ppp.h>
#include <net/if_pppvar.h>
#include <machine/cpu.h>

#define splsoftnet	splnet

#ifdef PPP_COMPRESS
#define PACKETPTR	struct mbuf *
#include <net/ppp-comp.h>
#endif

static int	pppsioctl __P((struct ifnet *, int, caddr_t));
static void	ppp_requeue __P((struct ppp_softc *));
#ifdef PPP_COMPRESS
static void	ppp_ccp __P((struct ppp_softc *, struct mbuf *m, int rcvd));
static void	ppp_ccp_closed __P((struct ppp_softc *));
#endif
static struct mbuf *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 steal two bits in the mbuf m_flags, to mark high-priority packets
 * for output, and received packets following lost/corrupted packets.
 */
#define M_HIGHPRI	0x2000	/* output packet for sc_fastq */
#define M_ERRMARK	0x4000	/* steal a bit in mbuf m_flags */


#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
    &ppp_bsd_compress,
#endif
#if DO_DEFLATE
    &ppp_deflate,
    &ppp_deflate_draft,
#endif
    NULL
};
#endif /* PPP_COMPRESS */

extern struct ifqueue    ipintrq;
static struct timeval    ppp_time;

#ifndef __rtems__
TEXT_SET(pseudo_set, ppp_rxdaemon);
#endif

static rtems_task ppp_rxdaemon(rtems_task_argument arg)
{
  rtems_event_set             events;
  rtems_interrupt_level       level;
  struct ppp_softc           *sc = (struct ppp_softc *)arg;
  struct mbuf                *mp = (struct mbuf      *)0;
  struct mbuf                *m;

  /* enter processing loop */
  while ( 1 ) {
    /* wait for event */
    rtems_event_receive(RX_PACKET|RX_MBUF|RX_EMPTY,RTEMS_WAIT|RTEMS_EVENT_ANY,RTEMS_NO_TIMEOUT,&events);
    if ( events & RX_EMPTY ) {
      printf("RX: QUEUE is EMPTY\n");
      events &= ~RX_EMPTY;
    }

    if ( events ) {
      /* get the network semaphore */
      rtems_bsdnet_semaphore_obtain();

      /* check to see if new packet was received */
      if ( events & RX_PACKET ) {
        /* get received packet mbuf chain */
        rtems_interrupt_disable(level);
        IF_DEQUEUE(&sc->sc_rawq, m);
        rtems_interrupt_enable(level);

        /* ensure packet was retrieved */
        if ( m != (struct mbuf *)0 ) {
          /* process the received packet */
          mp = ppp_inproc(sc, m);
        }
      }

      /* allocate a new mbuf to replace one */
      if ( mp == NULL ) {
        pppallocmbuf(sc, &mp);
      }

      /* place mbuf on freeq */
      rtems_interrupt_disable(level);
      IF_ENQUEUE(&sc->sc_freeq, mp);
      rtems_interrupt_enable(level);
      mp = (struct mbuf *)0;

      /* release the network semaphore */
      rtems_bsdnet_semaphore_release();

      /* check to see if queue is empty */
      if ( sc->sc_rawq.ifq_head ) {
        /* queue is not empty - post another event */
        rtems_event_send(sc->sc_rxtask, RX_PACKET);
      }
    }
  }
}

static rtems_task ppp_txdaemon(rtems_task_argument arg)
{
  rtems_event_set             events;
  int                         iprocess = (int               )0;
  struct ppp_softc           *sc       = (struct ppp_softc *)arg;
  struct mbuf                *mp;
  struct mbuf                *mf;
  struct mbuf                *m;
  struct rtems_termios_tty   *tp;
  
  int frag;

  /* enter processing loop */
  while ( 1 ) {
    /* wait for event */
    rtems_event_receive(TX_PACKET|TX_TRANSMIT,RTEMS_WAIT|RTEMS_EVENT_ANY,RTEMS_NO_TIMEOUT,&events);
    if ( events & TX_TRANSMIT ) {
      /* received event from interrupt handler - free current mbuf */
      rtems_bsdnet_semaphore_obtain();

      m_freem(sc->sc_outm);
      
      rtems_bsdnet_semaphore_release();

      /* chain is done - clear the values */
      sc->sc_outm  = (struct mbuf *)0;
      sc->sc_outmc = (struct mbuf *)0;

      /* now set flag to fake receive of TX_PACKET event */
      /* this will check to see if we have any pending packets */
      events |= TX_PACKET;
    }

    /* received event from pppasyncstart */
    if ( events & TX_PACKET ) {
      /* ensure we are not busy */
      if ( sc->sc_outm == (struct mbuf *)0 ) {
        /* try dequeuing a packet */
        sc->sc_outm = ppp_dequeue(sc);
        if ( sc->sc_outm == NULL ) {
          /* clear output flags */
          sc->sc_outflag      = 0;
          sc->sc_if.if_flags &= ~IFF_OACTIVE;
        }
        else {
          /* set flag to start process */
          iprocess            = 1;
          sc->sc_outflag      = SC_TX_BUSY;
          sc->sc_if.if_flags |= IFF_OACTIVE;
        }
      }
    }

    /* check to see if there is any processing required */
    if ( iprocess ) {
      /* clear process flag */
      iprocess = (int)0;
      frag=0;

      /* initialize output values */
      sc->sc_outfcs    = PPP_INITFCS;
      sc->sc_outbuf    = (u_char *)0;
      sc->sc_outlen    = (short   )0;
      sc->sc_outoff    = (short   )0;
      sc->sc_outfcslen = (short   )0;

/*	  printf("Start Transmit Packet..\n"); */

      /* loop over all mbufs in chain */
      mf     = NULL;
      mp     = NULL;
      m      = sc->sc_outm;

      sc->sc_outmc  = m;
      sc->sc_outlen = m->m_len;
      sc->sc_outbuf = mtod(m, u_char *);

      while (( m != (struct mbuf *)0 ) && ( m->m_len > 0 )) {
      	frag++;

        /* update the FCS value and then check next packet length */
        if(m->m_len){
       	 sc->sc_outfcs = pppfcs(sc->sc_outfcs, mtod(m, u_char *), m->m_len);
       	}

        if(( m->m_next != NULL ) && ( m->m_next->m_len == 0 )) {
			if(mf){
				printf(" if_ppp.c : MBUF Error !!!!\n");
			}
			else{
            	mf = m->m_next;
	        	m->m_next = NULL;
			}
		}

#ifdef LALL_X
        /* check next packet to see if it is empty */
        while (( m->m_next != NULL ) && ( m->m_next->m_len == 0 )) {
          /* next mbuf is zero length */
          /* add empty mbuf to free chain */
          if ( mp == NULL ) {
            /* item is head of free list */
            mf = m->m_next;
            mp = mf;
          }
          else {
            /* add item to end of the free list */
            mp->m_next = m->m_next;
            mp         = m->m_next;
          }

          /* remove empty item from process chain */
          m->m_next  = m->m_next->m_next;
          mp->m_next = NULL;
        }
#endif
        /* move to next packet */
        m = m->m_next;
      }

      /* ensure there is data to be sent out */
      tp = (struct rtems_termios_tty *)sc->sc_devp;
      if (( tp != NULL ) && ( sc->sc_outmc != (struct mbuf *)0 )) {
        /* place FCS value into buffer */
        sc->sc_outfcsbuf[sc->sc_outfcslen++] = ~sc->sc_outfcs & 0xff;
        sc->sc_outfcsbuf[sc->sc_outfcslen++] = (~sc->sc_outfcs >> 8) & 0xff;
        microtime(&sc->sc_if.if_lastchange);
  
        /* write out frame byte to start the transmission */
		sc->sc_outchar = (u_char)PPP_FLAG;
        (*tp->device.write)(tp->minor, &sc->sc_outchar, 1);
      }

      /* check to see if we need to free some empty mbufs */
      if ( mf != (struct mbuf *)0 ) {
        /* free empty mbufs */
        rtems_bsdnet_semaphore_obtain();
        m_freem(mf);
        rtems_bsdnet_semaphore_release();
      }
    }
  }
}

static void ppp_init(struct ppp_softc *sc)
{
  rtems_status_code   status;
  rtems_unsigned32    priority = 100;

  /* determine priority value */
  if ( rtems_bsdnet_config.network_task_priority ) {
    priority = rtems_bsdnet_config.network_task_priority;
  }

  /* check to see if we need to start up daemons */
  if ( sc->sc_rxtask == 0 ) {
    /* start rx daemon task */
    status = rtems_task_create(rtems_build_name('R','x','P','0'+sc->sc_if.if_unit), priority, 2048,
                               RTEMS_PREEMPT|RTEMS_NO_TIMESLICE|RTEMS_NO_ASR|RTEMS_INTERRUPT_LEVEL(0),
                               RTEMS_NO_FLOATING_POINT|RTEMS_LOCAL,
                               &sc->sc_rxtask);
    if (status != RTEMS_SUCCESSFUL) {
      rtems_fatal_error_occurred(status);
    }
    else {
      status = rtems_task_start(sc->sc_rxtask, ppp_rxdaemon, (rtems_task_argument)sc);
      if (status != RTEMS_SUCCESSFUL) {
        rtems_fatal_error_occurred(status);
      }
    }

    /* start tx daemon task */
    status = rtems_task_create(rtems_build_name('T','x','P','0'+sc->sc_if.if_unit), priority, 2048,
                               RTEMS_PREEMPT|RTEMS_NO_TIMESLICE|RTEMS_NO_ASR|RTEMS_INTERRUPT_LEVEL(0),
                               RTEMS_NO_FLOATING_POINT|RTEMS_LOCAL,
                               &sc->sc_txtask);
    if (status != RTEMS_SUCCESSFUL) {
      rtems_fatal_error_occurred(status);
    }
    else {
      status = rtems_task_start(sc->sc_txtask, ppp_txdaemon, (rtems_task_argument)sc);
      if (status != RTEMS_SUCCESSFUL) {
        rtems_fatal_error_occurred(status);
      }
    }
  }

  /* mark driver running and output inactive */
  /* ilya: IFF_RUNNING flag will be marked after the IPCP goes up */
/*  sc->sc_if.if_flags |= IFF_RUNNING;	*/
}

/*
 * Called from boot code to establish ppp interfaces.
 */
int rtems_ppp_driver_attach(struct rtems_bsdnet_ifconfig *config, int attaching)
{
/*    int                 i = (int)0;	*/
    struct ppp_softc   *sc;
    char               *name;
    int                 number;
    
    
    number = rtems_bsdnet_parse_driver_name (config, &name);
    
    if (!attaching || (number >= NPPP))
        return 0;
	
    sc = &ppp_softc[number];
    
    if (sc->sc_if.if_name != NULL)
	return 0;	/* interface is already attached */
    
/*    for (sc = ppp_softc; i < NPPP; sc++) {	*/
	sc->sc_if.if_name = name /*"ppp"*/;
	sc->sc_if.if_unit = number /*i++*/;
	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;
	sc->sc_freeq.ifq_maxlen = NUM_MBUFQ;

        /* initialize and attach */
	ppp_init(sc);
	if_attach(&sc->sc_if);
#if NBPFILTER > 0
	bpfattach(&sc->sc_bpf, &sc->sc_if, DLT_PPP, PPP_HDRLEN);
#endif
/*    }	*/

    return ( 1 );
}

/*
 * 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 vjcompress *, sizeof(struct vjcompress),
	   M_DEVBUF, M_NOWAIT);
    if (sc->sc_comp)
	vj_compress_init(sc->sc_comp, -1);
#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;
    microtime(&ppp_time);
    sc->sc_last_sent = sc->sc_last_recv = ppp_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;
    rtems_interrupt_level       level;

    if_down(&sc->sc_if);
    sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
    sc->sc_devp = NULL;
    sc->sc_xfer = 0;

    rtems_interrupt_disable(level);
    if ( sc->sc_m != NULL ) {
	m_freem(sc->sc_m);
        sc->sc_m = (struct mbuf *)0;
    }
    if ( sc->sc_outm != NULL ) {
	m_freem(sc->sc_outm);
        sc->sc_outm    = (struct mbuf *)0;
        sc->sc_outmc   = (struct mbuf *)0;
        sc->sc_outflag = 0;
    }
    do {
      IF_DEQUEUE(&sc->sc_freeq, m);
      if (m != NULL) {
        m_freem(m);
      }
    } while ( m != NULL );
    do {
      IF_DEQUEUE(&sc->sc_rawq, m);
      if (m != NULL) {
        m_freem(m);
      }
    } while ( m != NULL );
    rtems_interrupt_enable(level);

    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);
    }
#ifdef PPP_COMPRESS
    ppp_ccp_closed(sc);
    sc->sc_xc_state = NULL;
    sc->sc_rc_state = NULL;
#endif /* PPP_COMPRESS */
#ifdef PPP_FILTER