ppp.c

lwip-1.4.0

/*****************************************************************************
* ppp.c - Network Point to Point Protocol program file.
*
* Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
* portions Copyright (c) 1997 by Global Election Systems Inc.
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice and the following disclaimer are included verbatim in any 
* distributions. No written agreement, license, or royalty fee is required
* for any of the authorized uses.
*
* THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
* IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
******************************************************************************
* REVISION HISTORY
*
* 03-01-01 Marc Boucher <[e-mail]>
*   Ported to lwIP.
* 97-11-05 Guy Lancaster <[e-mail]>, Global Election Systems Inc.
*   Original.
*****************************************************************************/

/*
 * ppp_defs.h - PPP definitions.
 *
 * if_pppvar.h - private structures and declarations for PPP.
 *
 * Copyright (c) 1994 The Australian National University.
 * All rights reserved.
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation is hereby granted, provided that the above copyright
 * notice appears in all copies.  This software is provided without any
 * warranty, express or implied. The Australian National University
 * makes no representations about the suitability of this software for
 * any purpose.
 *
 * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
 * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
 * THE AUSTRALIAN NATIONAL UNIVERSITY HAVE BEEN ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
 * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
 * OR MODIFICATIONS.
 */

/*
 * if_ppp.h - Point-to-Point Protocol definitions.
 *
 * 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 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include "lwip/opt.h"

#if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */

#include "lwip/ip.h" /* for ip_input() */

#include "ppp.h"
#include "pppdebug.h"

#include "randm.h"
#include "fsm.h"
#if PAP_SUPPORT
#include "pap.h"
#endif /* PAP_SUPPORT */
#if CHAP_SUPPORT
#include "chap.h"
#endif /* CHAP_SUPPORT */
#include "ipcp.h"
#include "lcp.h"
#include "magic.h"
#include "auth.h"
#if VJ_SUPPORT
#include "vj.h"
#endif /* VJ_SUPPORT */
#if PPPOE_SUPPORT
#include "netif/ppp_oe.h"
#endif /* PPPOE_SUPPORT */

#include "lwip/tcpip.h"
#include "lwip/api.h"
#include "lwip/snmp.h"

#include <string.h>

/*************************/
/*** LOCAL DEFINITIONS ***/
/*************************/

/** PPP_INPROC_MULTITHREADED==1 call pppInput using tcpip_callback().
 * Set this to 0 if pppInProc is called inside tcpip_thread or with NO_SYS==1.
 * Default is 1 for NO_SYS==0 (multithreaded) and 0 for NO_SYS==1 (single-threaded).
 */
#ifndef PPP_INPROC_MULTITHREADED
#define PPP_INPROC_MULTITHREADED (NO_SYS==0)
#endif

/** PPP_INPROC_OWNTHREAD==1: start a dedicated RX thread per PPP session.
 * Default is 0: call pppos_input() for received raw characters, charcater
 * reception is up to the port */
#ifndef PPP_INPROC_OWNTHREAD
#define PPP_INPROC_OWNTHREAD      PPP_INPROC_MULTITHREADED
#endif

#if PPP_INPROC_OWNTHREAD && !PPP_INPROC_MULTITHREADED
  #error "PPP_INPROC_OWNTHREAD needs PPP_INPROC_MULTITHREADED==1"
#endif

/*
 * The basic PPP frame.
 */
#define PPP_ADDRESS(p)  (((u_char *)(p))[0])
#define PPP_CONTROL(p)  (((u_char *)(p))[1])
#define PPP_PROTOCOL(p) ((((u_char *)(p))[2] << 8) + ((u_char *)(p))[3])

/* PPP packet parser states.  Current state indicates operation yet to be
 * completed. */
typedef enum {
  PDIDLE = 0,  /* Idle state - waiting. */
  PDSTART,     /* Process start flag. */
  PDADDRESS,   /* Process address field. */
  PDCONTROL,   /* Process control field. */
  PDPROTOCOL1, /* Process protocol field 1. */
  PDPROTOCOL2, /* Process protocol field 2. */
  PDDATA       /* Process data byte. */
} PPPDevStates;

#define ESCAPE_P(accm, c) ((accm)[(c) >> 3] & pppACCMMask[c & 0x07])

/************************/
/*** LOCAL DATA TYPES ***/
/************************/

/** RX buffer size: this may be configured smaller! */
#ifndef PPPOS_RX_BUFSIZE
#define PPPOS_RX_BUFSIZE    (PPP_MRU + PPP_HDRLEN)
#endif

typedef struct PPPControlRx_s {
  /** unit number / ppp descriptor */
  int pd;
  /** the rx file descriptor */
  sio_fd_t fd;
  /** receive buffer - encoded data is stored here */
  u_char rxbuf[PPPOS_RX_BUFSIZE];

  /* The input packet. */
  struct pbuf *inHead, *inTail;

#if PPPOS_SUPPORT
  u16_t inProtocol;             /* The input protocol code. */
  u16_t inFCS;                  /* Input Frame Check Sequence value. */
#endif /* PPPOS_SUPPORT */
  PPPDevStates inState;         /* The input process state. */
  char inEscaped;               /* Escape next character. */
  ext_accm inACCM;              /* Async-Ctl-Char-Map for input. */
} PPPControlRx;

/*
 * PPP interface control block.
 */
typedef struct PPPControl_s {
  PPPControlRx rx;
  char openFlag;                /* True when in use. */
#if PPPOE_SUPPORT
  struct netif *ethif;
  struct pppoe_softc *pppoe_sc;
#endif /* PPPOE_SUPPORT */
  int  if_up;                   /* True when the interface is up. */
  int  errCode;                 /* Code indicating why interface is down. */
#if PPPOS_SUPPORT
  sio_fd_t fd;                  /* File device ID of port. */
#endif /* PPPOS_SUPPORT */
  u16_t mtu;                    /* Peer's mru */
  int  pcomp;                   /* Does peer accept protocol compression? */
  int  accomp;                  /* Does peer accept addr/ctl compression? */
  u_long lastXMit;              /* Time of last transmission. */
  ext_accm outACCM;             /* Async-Ctl-Char-Map for output. */
#if PPPOS_SUPPORT && VJ_SUPPORT
  int  vjEnabled;               /* Flag indicating VJ compression enabled. */
  struct vjcompress vjComp;     /* Van Jacobson compression header. */
#endif /* PPPOS_SUPPORT && VJ_SUPPORT */

  struct netif netif;

  struct ppp_addrs addrs;

  void (*linkStatusCB)(void *ctx, int errCode, void *arg);
  void *linkStatusCtx;

} PPPControl;


/*
 * Ioctl definitions.
 */

struct npioctl {
  int         protocol; /* PPP procotol, e.g. PPP_IP */
  enum NPmode mode;
};



/***********************************/
/*** LOCAL FUNCTION DECLARATIONS ***/
/***********************************/
#if PPPOS_SUPPORT
#if PPP_INPROC_OWNTHREAD
static void pppInputThread(void *arg);
#endif /* PPP_INPROC_OWNTHREAD */
static void pppDrop(PPPControlRx *pcrx);
static void pppInProc(PPPControlRx *pcrx, u_char *s, int l);
#endif /* PPPOS_SUPPORT */


/******************************/
/*** PUBLIC DATA STRUCTURES ***/
/******************************/
u_long subnetMask;

static PPPControl pppControl[NUM_PPP]; /* The PPP interface control blocks. */

/*
 * PPP Data Link Layer "protocol" table.
 * One entry per supported protocol.
 * The last entry must be NULL.
 */
struct protent *ppp_protocols[] = {
  &lcp_protent,
#if PAP_SUPPORT
  &pap_protent,
#endif /* PAP_SUPPORT */
#if CHAP_SUPPORT
  &chap_protent,
#endif /* CHAP_SUPPORT */
#if CBCP_SUPPORT
  &cbcp_protent,
#endif /* CBCP_SUPPORT */
  &ipcp_protent,
#if CCP_SUPPORT
  &ccp_protent,
#endif /* CCP_SUPPORT */
  NULL
};


/*
 * Buffers for outgoing packets.  This must be accessed only from the appropriate
 * PPP task so that it doesn't need to be protected to avoid collisions.
 */
u_char outpacket_buf[NUM_PPP][PPP_MRU+PPP_HDRLEN];


/*****************************/
/*** LOCAL DATA STRUCTURES ***/
/*****************************/

#if PPPOS_SUPPORT
/*
 * FCS lookup table as calculated by genfcstab.
 * @todo: smaller, slower implementation for lower memory footprint?
 */
static const u_short fcstab[256] = {
  0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
  0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
  0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
  0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
  0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
  0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
  0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
  0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
  0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
  0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
  0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
  0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
  0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
  0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
  0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
  0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
  0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
  0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
  0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
  0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
  0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
  0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
  0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
  0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
  0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
  0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
  0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
  0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
  0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
  0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
  0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
  0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
};

/* PPP's Asynchronous-Control-Character-Map.  The mask array is used
 * to select the specific bit for a character. */
static u_char pppACCMMask[] = {
  0x01,
  0x02,
  0x04,
  0x08,
  0x10,
  0x20,
  0x40,
  0x80
};

/** Wake up the task blocked in reading from serial line (if any) */
static void
pppRecvWakeup(int pd)
{
  PPPDEBUG(LOG_DEBUG, ("pppRecvWakeup: unit %d\n", pd));
  if (pppControl[pd].openFlag != 0) {
    sio_read_abort(pppControl[pd].fd);
  }
}
#endif /* PPPOS_SUPPORT */

void
pppLinkTerminated(int pd)
{
  PPPDEBUG(LOG_DEBUG, ("pppLinkTerminated: unit %d\n", pd));

#if PPPOE_SUPPORT
  if (pppControl[pd].ethif) {
    pppoe_disconnect(pppControl[pd].pppoe_sc);
  } else
#endif /* PPPOE_SUPPORT */
  {
#if PPPOS_SUPPORT
    PPPControl* pc;
    pppRecvWakeup(pd);
    pc = &pppControl[pd];

    PPPDEBUG(LOG_DEBUG, ("pppLinkTerminated: unit %d: linkStatusCB=%p errCode=%d\n", pd, pc->linkStatusCB, pc->errCode));
    if (pc->linkStatusCB) {
      pc->linkStatusCB(pc->linkStatusCtx, pc->errCode ? pc->errCode : PPPERR_PROTOCOL, NULL);
    }

    pc->openFlag = 0;/**/
#endif /* PPPOS_SUPPORT */
  }
  PPPDEBUG(LOG_DEBUG, ("pppLinkTerminated: finished.\n"));
}

void
pppLinkDown(int pd)
{
  PPPDEBUG(LOG_DEBUG, ("pppLinkDown: unit %d\n", pd));

#if PPPOE_SUPPORT
  if (pppControl[pd].ethif) {
    pppoe_disconnect(pppControl[pd].pppoe_sc);
  } else
#endif /* PPPOE_SUPPORT */
  {
#if PPPOS_SUPPORT
    pppRecvWakeup(pd);
#endif /* PPPOS_SUPPORT */
  }
}

/** Initiate LCP open request */
static void
pppStart(int pd)
{
  PPPDEBUG(LOG_DEBUG, ("pppStart: unit %d\n", pd));
  lcp_lowerup(pd);
  lcp_open(pd); /* Start protocol */
  PPPDEBUG(LOG_DEBUG, ("pppStart: finished\n"));
}

/** LCP close request */
static void
pppStop(int pd)
{
  PPPDEBUG(LOG_DEBUG, ("pppStop: unit %d\n", pd));
  lcp_close(pd, "User request");
}

/** Called when carrier/link is lost */
static void
pppHup(int pd)
{
  PPPDEBUG(LOG_DEBUG, ("pppHupCB: unit %d\n", pd));
  lcp_lowerdown(pd);
  link_terminated(pd);
}

/***********************************/
/*** PUBLIC FUNCTION DEFINITIONS ***/
/***********************************/
/* Initialize the PPP subsystem. */

struct ppp_settings ppp_settings;

void
pppInit(void)
{
  struct protent *protp;
  int i, j;

  memset(&ppp_settings, 0, sizeof(ppp_settings));
  ppp_settings.usepeerdns = 1;
  pppSetAuth(PPPAUTHTYPE_NONE, NULL, NULL);

  magicInit();

  subnetMask = PP_HTONL(0xffffff00UL);

  for (i = 0; i < NUM_PPP; i++) {
    /* Initialize each protocol to the standard option set. */
    for (j = 0; (protp = ppp_protocols[j]) != NULL; ++j) {
      (*protp->init)(i);
    }
  }
}

void
pppSetAuth(enum pppAuthType authType, const char *user, const char *passwd)
{
  switch(authType) {
    case PPPAUTHTYPE_NONE:
    default:
#ifdef LWIP_PPP_STRICT_PAP_REJECT
      ppp_settings.refuse_pap = 1;
#else  /* LWIP_PPP_STRICT_PAP_REJECT */
      /* some providers request pap and accept an empty login/pw */
      ppp_settings.refuse_pap = 0;
#endif /* LWIP_PPP_STRICT_PAP_REJECT */
      ppp_settings.refuse_chap = 1;
      break;

    case PPPAUTHTYPE_ANY:
      /* Warning: Using PPPAUTHTYPE_ANY might have security consequences.
       * RFC 1994 says:
       *
       * In practice, within or associated with each PPP server, there is a
       * database which associates "user" names with authentication
       * information ("secrets").  It is not anticipated that a particular
       * named user would be authenticated by multiple methods.  This would
       * make the user vulnerable to attacks which negotiate the least secure
       * method from among a set (such as PAP rather than CHAP).  If the same
       * secret was used, PAP would reveal the secret to be used later with
       * CHAP.
       *
       * Instead, for each user name there should be an indication of exactly
       * one method used to authenticate that user name.  If a user needs to
       * make use of different authentication methods under different
       * circumstances, then distinct user names SHOULD be employed, each of
       * which identifies exactly one authentication method.
       *
       */
      ppp_settings.refuse_pap = 0;
      ppp_settings.refuse_chap = 0;
      break;

    case PPPAUTHTYPE_PAP:
      ppp_settings.refuse_pap = 0;
      ppp_settings.refuse_chap = 1;
      break;

    case PPPAUTHTYPE_CHAP:
      ppp_settings.refuse_pap = 1;
      ppp_settings.refuse_chap = 0;
      break;
  }

  if(user) {
    strncpy(ppp_settings.user, user, sizeof(ppp_settings.user)-1);
    ppp_settings.user[sizeof(ppp_settings.user)-1] = '\0';
  } else {