parser.c

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/*
 *  Embedded SLP Message Parsers
 *
 *  ./software/ch10/emslp/parser.c
 *
 *  [e-mail]
 *
 */

#include <stdio.h>
#include <string.h>
#include "manip.h"
#include "slppriv.h"

/*
 *  slpParseServiceReply()
 *
 *  Parse a service reply message from an SLP message.
 *
 */

int slpParseServiceReply( slpMsgType *slpMsg, slpParsedServiceReplyType *reply )
{
  uint8_t version, messageType;
  uint16_t xid, langLen, numUrls;
  int len;

  if ((slpMsg == NULL) || (reply == NULL)) {
    return -1;
  }

  /*
   *  First, verify that the version is correct and that the response is 
   *  a service reply. 
   */
  getByte(slpMsg, &version);
  getByte(slpMsg, &messageType);
  if (version != 2) {
    return -2;
  }

  getTriOctet(slpMsg, (uint32_t *)&len);

  /* Skip some unused portions of the header */
  getTriOctet(slpMsg, NULL);
  getShort(slpMsg, NULL);

  getShort(slpMsg, &xid);

  getShort(slpMsg, &langLen);
  getString(slpMsg, langLen, NULL);

  if (messageType == SRV_REPLY) {

    /* Store the error code and URL count into the reply */
    getShort( slpMsg, &reply->errorcode );
    getShort( slpMsg, (uint16_t *)&numUrls );

    if ((reply->errorcode != 0) || (numUrls == 0)) return -3;

    while ((numUrls--) && (reply->urlCount < MAX_URLS)) {

      getByte( slpMsg, NULL );			// Reserved Field
      getShort( slpMsg, &reply->urls[reply->urlCount].lifetime );
      getShort( slpMsg, (uint16_t *)&len );
      getString( slpMsg, len, (char *)&reply->urls[reply->urlCount].url[0] );
      getByte( slpMsg, NULL );			// Num Auth Blocks

      reply->urlCount++;

    }

  } else if (messageType == DA_ADVERT) {

    /* Store the error code count into the reply */
    getShort( slpMsg, &reply->errorcode );

    getShort( slpMsg, NULL );
    getShort( slpMsg, NULL );

    /* Get the directory-agent URL */
    getShort( slpMsg, (uint16_t *)&len );
    getString( slpMsg, len, (char *)&reply->urls[reply->urlCount].url[0] );

    if (len) reply->urlCount++;
  }

  return 0;

}


/*
 *  slpParseServiceTypesReply()
 *
 *  Parse a service type reply message from an SLP message.
 *
 */

int slpParseServiceTypesReply( slpMsgType *slpMsg, 
                               slpParsedServiceTypeReplyType *reply )
{
  uint8_t version, messageType;
  uint16_t xid, langLen, serviceOctets;
  int len, curOctet, srvIndex, srvChar;

  if ((slpMsg == NULL) || (reply == NULL)) {
    return -1;
  }

  /*
   *  First, verify that the version is correct and that the response is 
   *  a service-type reply. 
   */
  getByte(slpMsg, &version);
  getByte(slpMsg, &messageType);
  if ((version != 2) || (messageType != SRV_TYPE_REPLY)) {
    return -2;
  }

  getTriOctet(slpMsg, (uint32_t *)&len);

  /* Skip some unused portions of the header */
  getTriOctet(slpMsg, NULL);
  getShort(slpMsg, NULL);

  getShort(slpMsg, &xid);

  getShort(slpMsg, &langLen);
  getString(slpMsg, langLen, NULL);

  /* Store the error code and Services count into the reply */
  getShort( slpMsg, &reply->errorcode );
  getShort( slpMsg, (uint16_t *)&serviceOctets );

  if ((reply->errorcode != 0) || (serviceOctets == 0)) return -3;

  curOctet = 0;
  srvIndex = 0;
  srvChar = 0;

  while ((curOctet < serviceOctets) && (reply->srvCount < MAX_SERVICE_TYPES)) {

    if (slpMsg->buffer[slpMsg->index] == ',') {
      reply->service[srvIndex][srvChar] = 0;
      slpMsg->index++;
      srvChar = 0;
      srvIndex++;
    } else if (slpMsg->buffer[slpMsg->index] == 0) {
      srvIndex++;
      break;
    } else {
      reply->service[srvIndex][srvChar++] = slpMsg->buffer[slpMsg->index++];
    }

  }

  reply->srvCount = srvIndex;

  return 0;
}


/*
 *  slpParseServiceURL()
 *
 *  Parse a URL into its distinct elements.
 *
 */

int slpParseServiceURL ( char *url, 
                         char *serviceType,
                         char *addrSpec, 
                         char *port )
{
  int i, j, len;

  if ((url == NULL) || (serviceType == NULL) || 
      (addrSpec == NULL) || (port == NULL)) {
    return -1;
  }

  serviceType[0] = 0;
  addrSpec[0] = 0;
  port[0] = 0;

  if (strncmp(url, "service:", 8)) return -1;

  len = strlen(url);

  j = 0;
  i = 8;
  while ((i < len) && (url[i] != ':') && (url[i] != 0)) {
    serviceType[j++] = url[i++];
  }
  serviceType[j] = 0;

  if (!((url[i] == ':') && (url[i+1] == '/'))) {
    return -1;
  }

  j = 0;
  i+=3;
  while ((i < len) && (url[i] != ':') && (url[i] != 0)) {
    addrSpec[j++] = url[i++];
  }
  addrSpec[j] = 0;

  if (url[i] == 0) return 0;

  j = 0;
  i++;
  while ((i < len) && (url[i] != 0)) {
    port[j++] = url[i++];
  }
  port[j] = 0;
  
  return 0;
}

/*
 *  Copyright (c) 2002 Charles River Media.  All rights reserved.
 * 
 *  Redistribution and use in source and binary forms, with or 
 *  without modification, is hereby granted without fee 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.  Neither the name of Charles River Media nor the names of 
 *        its contributors may be used to endorse or promote products 
 *        derived from this software without specific prior 
 *        written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY CHARLES RIVER MEDIA AND CONTRIBUTERS 
 * 'AS IS' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS 
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL CHARLES
 * RIVER MEDIA OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
 * INCIDENTAL, SPECIAL, EXEMPLARAY, 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.
 */