nuttx-apps/netutils/pppd/lcp.c

/****************************************************************************
 * netutils/pppd/lcp.c
 * Link Configuration Protocol Handler
 *
 *   Version - 0.1 Original Version June 3, 2000 -
 *   Copyright (C) 2000, Mycal Labs www.mycal.com - -
 *   Copyright (c) 2003, Mike Johnson, Mycal Labs, www.mycal.net
 *   All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    This product includes software developed by Mike Johnson/Mycal Labs
 *    www.mycal.net.
 * 4. The name of the author may not be used to endorse or promote
 *    products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include "ppp_conf.h"
#include "ppp_arch.h"
#include "ppp.h"
#include "ahdlc.h"
#include "lcp.h"

#include <apps/netutils/pppd.h>

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

#if PPP_DEBUG
#  define DEBUG1(x) debug_printf x
#  define DEBUG2(x) debug_printf x
#else
#  define DEBUG1(x)
#  define DEBUG2(x)
#endif

/****************************************************************************
 * Private Types
 ****************************************************************************/

/* We need this when we neg our direction.
   u8_t lcp_tx_options; */

/* Define the supported parameters for this module here. */

static const u8_t lcplist[] =
{
  LPC_MAGICNUMBER,
  LPC_PFC,
  LPC_ACFC,
  LPC_AUTH,
  LPC_ACCM,
  LPC_MRU,
  0
};

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * lcp_init() - Initialize the LCP engine to startup values
 *
 ****************************************************************************/

void lcp_init(struct ppp_context_s *ctx)
{
  ctx->lcp_state = 0;
  ctx->lcp_retry = 0;
}

/****************************************************************************
 * lcp_rx() - Receive an LCP packet and process it.
 *    This routine receives a LCP packet in buffer of length count.
 *    Process it here, support for CONF_REQ, CONF_ACK, CONF_NACK, CONF_REJ or
 *    TERM_REQ.
 *
 ****************************************************************************/

void lcp_rx(struct ppp_context_s *ctx, u8_t *buffer, u16_t count)
{
  u8_t *bptr = buffer, *tptr;
  u8_t error = 0;
  u8_t id;
  u16_t len, j;
  struct pppd_settings_s *pppd_settings = ctx->settings;

  switch (*bptr++)
  {
  case CONF_REQ: /* config request */
    /* Parse request and see if we can ACK it */

    id = *bptr++;
    len = (*bptr++ << 8);
    len |= *bptr++;
    /*len -= 2;*/

    /* In case of new peer connection */

    ipcp_init(ctx);
    ctx->lcp_state &= ~LCP_TX_UP;

    DEBUG1(("received [LCP Config Request id %u\n", id));
    if (scan_packet(ctx, (u16_t)LCP, lcplist, buffer, bptr, (u16_t)(len-4)))
      {
        /* Must do the -4 here, !scan packet */

        DEBUG1((" options were rejected\n"));
      }
    else
      {
        /* Lets try to implement what peer wants */

        tptr = bptr = buffer;
        bptr += 4;            /* skip code, id, len */
        error = 0;

        /* First scan for unknown values */

        while(bptr < (buffer + len))
          {
            switch (*bptr++)
            {
            case LPC_MRU: /* mru */
              j = *bptr++;
              j -= 2;

              if (j == 2)
                {
                  ctx->ppp_tx_mru = ((int)*bptr++) << 8;
                  ctx->ppp_tx_mru |= *bptr++;
                  DEBUG1(("<mru %d> ", ctx->ppp_tx_mru));
                }
              else
                {
                  DEBUG1(("<mru ?? > "));
                }
              break;

            case LPC_ACCM:
              bptr++;  /* skip length */
              j = *bptr++;
              j += *bptr++;
              j += *bptr++;
              j += *bptr++;

              if (j==0)
                {
                  // ok
                  DEBUG1(("<asyncmap sum=0x%04x>",j));
                  //ahdlc_flags |= PPP_TX_ASYNC_MAP;
                }
              else if (j!=0)
                {
                  // ok
                  DEBUG1(("<asyncmap sum=0x%04x>, assume 0xffffffff",j));
                }
              else
                {
                  /* Fail.  We only support default or all zeros */

                  DEBUG1(("We only support default or all zeros for ACCM "));
                  error = 1;
                  *tptr++ = LPC_ACCM;
                  *tptr++ = 0x6;
                  *tptr++ = 0;
                  *tptr++ = 0;
                  *tptr++ = 0;
                  *tptr++ = 0;
                }
              break;

#ifdef CONFIG_NETUTILS_PPPD_PAP
            case LPC_AUTH:
              bptr++;
              if ((*bptr++ == 0xc0) && (*bptr++ == 0x23))
                {
                  /* Negotiate PAP */

                  if (strlen(pppd_settings->pap_username) > 0)
                    {
                      DEBUG1(("<auth pap> "));
                      ctx->lcp_state |= LCP_RX_AUTH;
                    }
                  else
                    {
                      DEBUG1(("<rej auth pap> "));

                      *tptr++ = CONF_REJ;
                      tptr++;             // Keep ID
                      *tptr++ = 0;
                      *tptr++ = 8;
                      *tptr++ = LPC_AUTH;
                      *tptr++ = 0x4;
                      *tptr++ = 0xc0;
                      *tptr++ = 0x23;
                      ahdlc_tx(ctx, LCP, 0, buffer, 0, (u16_t)(tptr-buffer));
                      return;
                    }
                }
              else
                {
                  /* We only support PAP */

                  DEBUG1(("<auth ?? >"));
                  error = 1;
                  *tptr++ = LPC_AUTH;
                  *tptr++ = 0x4;
                  *tptr++ = 0xc0;
                  *tptr++ = 0x23;
                }
              break;
#endif /* CONFIG_NETUTILS_PPPD_PAP */

            case LPC_MAGICNUMBER:
              DEBUG1(("<magic > "));

              /* Compare incoming number to our number (not implemented) */

              bptr++; /* For now just dump */
              bptr++;
              bptr++;
              bptr++;
              bptr++;
              break;

            case LPC_PFC:
              bptr++;
              DEBUG1(("<pcomp> "));
              /*tflag|=PPP_PFC;*/
              break;

            case LPC_ACFC:
              bptr++;
              DEBUG1(("<accomp> "));
              /*tflag|=PPP_ACFC;*/
              break;
            }
          }

        /* Error? if we we need to send a config Reject ++++ this is good
         * for a subroutine.
         */

        if (error)
          {
            /* Write the config NAK packet we've built above, take on the
             * header
             */

            bptr = buffer;
            *bptr++ = CONF_NAK;        /* Write Conf_rej */
            bptr++;/*tptr++;*/        /* skip over ID */

            /* Write new length */

            *bptr++ = 0;
            *bptr = tptr - buffer;

            /* Write the reject frame */

            DEBUG1(("\nWriting NAK frame \n"));
            // Send packet ahdlc_txz(procol,header,data,headerlen,datalen);
            ahdlc_tx(ctx, LCP, 0, buffer, 0, (u16_t)(tptr-buffer));
            DEBUG1(("- end NAK Write frame\n"));
          }
        else
          {
            /* If we get here then we are OK, lets send an ACK and tell the rest
             * of our modules our negotiated config.
             */

            DEBUG1(("\nSend ACK!\n"));
            bptr = buffer;
            *bptr++ = CONF_ACK;  /* Write Conf_ACK */
            bptr++;              /* Skip ID (send same one) */

            /* Set stuff */

            /*ppp_flags|=tflag;*/
            /* DEBUG2("SET- stuff -- are we up? c=%d dif=%d \n", count, (u16_t)(bptr-buffer)); */

            /* Write the ACK frame */

            DEBUG2(("Writing ACK frame \n"));

            /* Send packet ahdlc_txz(procol,header,data,headerlen,datalen); */

            ahdlc_tx(ctx, LCP, 0, buffer, 0, count /*bptr-buffer*/);
            DEBUG2(("- end ACK Write frame\n"));
            ctx->lcp_state |= LCP_RX_UP;
          }
      }
    break;

  case CONF_ACK: /* config Ack   Anytime we do an ack reset the timer to force send. */
    DEBUG1(("LCP-ACK - "));

    /* Check that ID matches one sent */

    if (*bptr++ == ctx->ppp_id)
      {
        /* Change state to PPP up. */

        DEBUG1((">>>>>>>> good ACK id up! %d\n", ctx->ppp_id));

        /* Copy negotiated values over */

        ctx->lcp_state |= LCP_TX_UP;
      }
    else
      {
        DEBUG1(("*************++++++++++ bad id %d\n", ctx->ppp_id));
      }
    break;

  case CONF_NAK: /* Config Nack */
    DEBUG1(("LCP-CONF NAK\n"));
    ctx->ppp_id++;
    break;

  case CONF_REJ: /* Config Reject */
    DEBUG1(("LCP-CONF REJ\n"));
    ctx->ppp_id++;
    break;

  case TERM_REQ: /* Terminate Request */
    DEBUG1(("LCP-TERM-REQ -"));
    bptr = buffer;
    *bptr++ = TERM_ACK; /* Write TERM_ACK */

    /* Write the reject frame */

    DEBUG1(("Writing TERM_ACK frame \n"));

    /* Send packet ahdlc_txz(procol,header,data,headerlen,datalen); */

    ahdlc_tx(ctx, LCP, 0, buffer, 0, count);

    ctx->lcp_state &= ~LCP_TX_UP;
    ctx->lcp_state |= LCP_TERM_PEER;
    break;

  case TERM_ACK:
    DEBUG1(("LCP-TERM ACK\n"));
    break;

  case ECHO_REQ:
    if ((ctx->lcp_state & LCP_TX_UP) && (ctx->lcp_state & LCP_RX_UP))
      {
        bptr = buffer;
        *bptr++ = ECHO_REP;   /* Write ECHO-REPLY */

        bptr += 3;            /* Skip id and length */

        *bptr++ = 0;          /* Zero Magic */
        *bptr++ = 0;
        *bptr++ = 0;
        *bptr++ = 0;

        /* Write the echo reply frame */

        DEBUG1(("\nWriting ECHO-REPLY frame \n"));
        // Send packet ahdlc_txz(procol,header,data,headerlen,datalen);
        ahdlc_tx(ctx, LCP, 0, buffer, 0, count);
        DEBUG1(("- end ECHO-REPLY Write frame\n"));
      }
    break;

  case ECHO_REP:
    DEBUG1(("LCP-ECHO REPLY\n"));
    if ((ctx->lcp_state & LCP_TX_UP) && (ctx->lcp_state & LCP_RX_UP))
      {
        ctx->ppp_id++;
      }
    break;

  default:
    DEBUG1(("LCP unknown packet: %02x", *(bptr-1)));
    break;
  }
}

/****************************************************************************
 * Name: lcp_disconnect
 ****************************************************************************/

void lcp_disconnect(struct ppp_context_s *ctx, u8_t id)
{
  u8_t buffer[4];
  u8_t *bptr = buffer;

  *bptr++ = TERM_REQ;
  *bptr++ = id;
  *bptr++ = 0;
  *bptr++ = 4;

  ahdlc_tx(ctx, LCP, 0, buffer, 0, bptr - buffer);
}

/****************************************************************************
 * Name: lcp_echo_request
 ****************************************************************************/

void lcp_echo_request(struct ppp_context_s *ctx, u8_t *buffer)
{
  u8_t *bptr;
  u16_t t;
  LCPPKT *pkt;

  if ((ctx->lcp_state & LCP_TX_UP) && (ctx->lcp_state & LCP_RX_UP))
  {
    if ((ppp_arch_clock_seconds() - ctx->lcp_prev_seconds) > LCP_ECHO_INTERVAL)
      {
        ctx->lcp_prev_seconds = ppp_arch_clock_seconds();

        pkt = (LCPPKT *)buffer;

        /* Configure-Request only here, write id */

        pkt->code = ECHO_REQ;
        pkt->id = ctx->ppp_id;

        bptr = pkt->data;

        *bptr++ = 0;
        *bptr++ = 0;
        *bptr++ = 0;
        *bptr++ = 0;

        /* Write length */

        t = bptr - buffer;
        pkt->len = htons(t); /* length here -  code and ID + */

        DEBUG1((" len %d\n",t));

        /* Send packet */
        /* Send packet ahdlc_txz(procol,header,data,headerlen,datalen); */

        DEBUG1(("\nWriting ECHO-REQUEST frame \n"));
        ahdlc_tx(ctx, LCP, 0, buffer, 0, t);
        DEBUG1(("- end ECHO-REQUEST Write frame\n"));
      }
  }
}

/****************************************************************************
 * lcp_task(buffer) - This routine see if a lcp request needs to be sent
 *    out.  It uses the passed buffer to form the packet.  This formed LCP
 *    request is what we negotiate for sending options on the link.
 *
 *    Currently we negotiate : Magic Number Only, but this will change.
 *
 ****************************************************************************/

void lcp_task(struct ppp_context_s *ctx, u8_t *buffer)
{
  u8_t *bptr;
  u16_t t;
  LCPPKT *pkt;

  /* lcp tx not up and hasn't timed out then lets see if we need to send a
   * request
   */

  if (!(ctx->lcp_state & LCP_TX_UP) && !(ctx->lcp_state & LCP_TX_TIMEOUT))
    {
      /* Check if we have a request pending */

      if ((ppp_arch_clock_seconds() - ctx->lcp_prev_seconds) > LCP_TIMEOUT)
        {
          ctx->lcp_prev_seconds = ppp_arch_clock_seconds();

          DEBUG1(("\nSending LCP request packet - "));

          /* No pending request, lets build one */

          pkt = (LCPPKT *)buffer;

          /* Configure-Request only here, write id */

          pkt->code = CONF_REQ;
          pkt->id = ctx->ppp_id;

          bptr = pkt->data;

          /* Write options */

          *bptr++ = LPC_ACCM;
          *bptr++ = 0x6;
          *bptr++ = 0xff;
          *bptr++ = 0xff;
          *bptr++ = 0xff;
          *bptr++ = 0xff;

#if 0
          /* Write magic number */

          DEBUG1(("LPC_MAGICNUMBER -"));
          *bptr++ = LPC_MAGICNUMBER;
          *bptr++ = 0x6;

          /*
          *bptr++ = random_rand() & 0xff;
          *bptr++ = random_rand() & 0xff;
          *bptr++ = random_rand() & 0xff;
          *bptr++ = random_rand() & 0xff;
          */

          *bptr++ = 0x11;
          *bptr++ = 0x11;
          *bptr++ = 0x11;
          *bptr++ = 0x11;
#endif

#if 0
          /* Authentication protocol */

          if ((lcp_tx_options & LCP_OPT_AUTH) && 0)
            {
              /* If turned on, we only negotiate PAP */

              *bptr++ = LPC_AUTH;
              *bptr++ = 0x4;
              *bptr++ = 0xc0;
              *bptr++ = 0x23;
            }

          /* PFC */

          if ((lcp_tx_options & LCP_OPT_PFC) && 0)
            {
              /* If turned on, we only negotiate PAP */

              *bptr++ = LPC_PFC;
              *bptr++ = 0x2;
            }

          /* ACFC */

          if ((lcp_tx_options & LCP_OPT_ACFC) && 0)
            {
              /* If turned on, we only negotiate PAP */

              *bptr++ = LPC_ACFC;
              *bptr++ = 0x2;
            }
#endif

          /* Write length */

          t = bptr - buffer;
          pkt->len = htons(t); /* length here -  code and ID + */

          DEBUG1((" len %d\n",t));

          /* Send packet */
          /* Send packet ahdlc_txz(procol,header,data,headerlen,datalen); */

          ahdlc_tx(ctx, LCP, 0, buffer, 0, t);

          /* Inc retry */

          ctx->lcp_retry++;

          /* Have we timed out? */

          if (ctx->lcp_retry > LCP_RETRY_COUNT)
            {
              ctx->lcp_state &= LCP_TX_TIMEOUT;
            }
        }
    }
}