---

packets_operations.c

Go to the documentation of this file.

/*! \file packets_operations.c
          This file implements output packet mechanism (OFFER, ACK or INFORM).
 */

#include "server_config.h" 
#include "packets_operations.h"
#include "dhcp.h"




static void clear_profile (struct opt *options);
static int add_option_to_profile (struct opt *mprofile, int option, char *type, char *value, int len);
static int remove_option_from_profile (struct opt *mprofile, int option);
static void context2profile (struct opt *profile, struct mysql_tables *mysql_tables);





/*! \brief Global DHCP configuration handler.
 */

extern struct global_config configuration_globale;

/*! \brief Reset option profile to "all zeros".
    \author Denis BEURIVE
    \param options Pointer to a destination 'opt' data structure to reset.
    \warning The pointer 'options' should point to an array which contains at least MAX_PROFILE_OPTIONS
             (which should be greater than 256) elements.
 */

static void clear_profile (struct opt *options)
{
  int i;

  for (i=0; i<MAX_PROFILE_OPTIONS; i++)
  {
    options[i].code = 0;
    options[i].len  = 0;
    memset ((void*)(options[i]).value, 0, VALUE_MAX_SIZE);
  }
}

/*! \brief Add an option to the loaded profile.
    \author Denis BEURIVE
    \param mprofile Pointer to an array of 'opt' data structures that represents the profile to manipulate.
    \param option Option's code (between 1 and 254 included).
    \param type Pointer to a zero terminated string of characters the represents the type of value.
           Type could be:
                <UL>
                    <LI>"UINT32" (values are separated by ':')
                    <LI>"UINT16" (values are separated by ':')
                    <LI>"IP" (values are separated by ':')
                    <LI>"HEXA-BYTE"
                    <LI>"ASCII-BYTE"
                </UL>
    \param value Pointer to the value. The format of the value depends on its type.
    \param len Number of bytes of the value.
    \return Upon successful completion, the function returns the value 0.
            Otherwize, the function returns the value 1.
 */

static int add_option_to_profile (struct opt *mprofile, int option, char *type, char *value, int len)
{
    int         converted;

    /* ------------------------------------------------- */
    /* Sanity check                                      */
    /* ------------------------------------------------- */

    if ((option > 254) || (option < 1))
    {
       my_syslog (configuration_globale.log_file,
                  "[INTERNAL ERROR] [%s:%d] add_option_to_profile: invalid option's value (%d)",
                  __FILE__, __LINE__,
                  option);
       return 1;
    }

    converted = 0;

    if (strcmp(type, "UINT32") == 0)
    {
      int rc = uint32_to_network_byte_order (value, (mprofile[option]).value, VALUE_MAX_SIZE);
      if (rc == -1) { return 1; }
      (mprofile[option]).len = rc * 4;
      (mprofile[option]).code = option;
      converted = 1;
    }

    if (strcmp(type, "UINT16") == 0)
    {
      int rc = uint16_to_network_byte_order (value, (mprofile[option]).value, VALUE_MAX_SIZE);
      if (rc == -1) { return 1; }
      (mprofile[option]).len = rc * 2;
      (mprofile[option]).code = option;
      converted = 1;
    }

    if (strcmp(type, "HEXA-BYTE") == 0)
    {
      int rc = hexa_to_binary (value, (mprofile[option]).value, VALUE_MAX_SIZE);
      if (rc == -1) { return 1; }
      (mprofile[option]).len = rc;
      (mprofile[option]).code = option;
      converted = 1;
    }

    if (strcmp(type, "ASCII-BYTE") == 0)
    {
      int rc = ascii_to_binary (value, (mprofile[option]).value, len, VALUE_MAX_SIZE);
      if (rc == -1) { return 1; }
      (mprofile[option]).len = rc;
      (mprofile[option]).code = option;
      converted = 1;
    }

    if (strcmp(type, "IP") == 0)
    {
      int rc = ip_to_network_byte_order (value, (mprofile[option]).value, VALUE_MAX_SIZE);
      if (rc == -1) { return 1; }
      (mprofile[option]).len = rc * 4;
      (mprofile[option]).code = option;
      converted = 1;
    }

    if (converted == 0)
    {
      my_syslog (configuration_globale.log_file,
                 "[ERROR] [%s:%d] Invalid option type (%s) for option", __FILE__, __LINE__, type);
      return 1;
    }

    return 0;
}

/*! \brief Remove an option from the loaded profile.
    \author Denis BEURIVE
    \param mprofile Pointer to an array of 'opt' data structures that represents the profile to manipulate.
    \param option Option's code (between 1 and 254 included).
    \return Upon successful completion, the function returns the value 0.
            Otherwize, the function returns the value 1.
 */

static int remove_option_from_profile (struct opt *mprofile, int option)
{
    if ((option > 254) || (option < 1))
    {
       my_syslog (configuration_globale.log_file,
       "[INTERNAL ERROR] [%s:%d] remove_option_from_profile: invalid option's value (%d)",
       __FILE__, __LINE__,
       option);
       return 1;
    }

    (mprofile[option]).code = 0;
    (mprofile[option]).len  = 0;

    memset ((void*)(mprofile[option]).value, 0, VALUE_MAX_SIZE);

    return 0;
}

/*! \brief Copy the options' profile extracted from the client's context into a 'opt' data structure (used
           to assemble the output DHCP packet).
    \author Denis BEURIVE
    \param profile Pointer to a destination 'opt' data structure.
    \param mysql_tables Pointer to a 'mysql_tables' data structure that contains the client's context (loaded
           form the database).
    \remark Types of options' values can be:
            <UL>
                <LI>"UINT32" (one or more values, separated by ':')
                <LI>"UINT16" (one or more values, separated by ':')
                <LI>"IP" (one or more values, separated by ':')
                <LI>"HEXA-BYTE"
                <LI>"ASCII-BYTE"
            </UL>
    \warning The pointer 'options' should point to an array which contains at least MAX_PROFILE_OPTIONS
             (which should be greater than 256) elements.
 */

static void context2profile (struct opt *profile, struct mysql_tables *mysql_tables)
{
  int  i, code, converted;
  char *type;
  char *value;


  clear_profile (profile);

  /* --------------------------------------------------- */
  /* Convert all values to the correct internal format   */
  /* --------------------------------------------------- */

  for (i=0; i<mysql_tables->option_number; i++)
  {
    code = (int)(((mysql_tables->options)[i]).option_code);

    /* ------------------------------------------------- */
    /* Sanity check                                      */
    /* ------------------------------------------------- */

    if ((code > 254) || (code < 1))
    {
      my_syslog (configuration_globale.log_file,
                 "[WARNING] [%s:%d] Invalid option code (%u) for profile_optionnel=[%s], SKIP",
                 __FILE__, __LINE__,
                 code,
                 ((mysql_tables->options)[i]).profile_optionnel);
      continue;
    }

    /* ------------------------------------------------- */
    /* 'option_value' needs to be interpreted depending  */
    /* on the value of 'option_type'.                    */
    /* The following code set the following values :     */
    /*      + (profile[code]).code                       */ 
    /*      + (profile[code]).len                        */
    /*      + (profile[code]).value.                     */
    /* ------------------------------------------------- */

    type  = ((mysql_tables->options)[i]).option_type;
    value = ((mysql_tables->options)[i]).option_value;

    converted = 0;

    if (strcmp(type, "UINT32") == 0)
    {
      int rc = uint32_to_network_byte_order (value, (profile[code]).value, VALUE_MAX_SIZE);
      if (rc == -1) { continue; }
      (profile[code]).len = rc * 4;
      (profile[code]).code = code;
      converted = 1;
    }

    if (strcmp(type, "UINT16") == 0)
    {
      int rc = uint16_to_network_byte_order (value, (profile[code]).value, VALUE_MAX_SIZE);
      if (rc == -1) { continue; }
      (profile[code]).len = rc * 2;
      (profile[code]).code = code;
      converted = 1;
    }

    if (strcmp(type, "HEXA-BYTE") == 0)
    {
      int rc = hexa_to_binary (value, (profile[code]).value, VALUE_MAX_SIZE);
      if (rc == -1) { continue; }
      (profile[code]).len = rc;
      (profile[code]).code = code;
      converted = 1;
    }

    if (strcmp(type, "ASCII-BYTE") == 0)
    {
      int rc = ascii_to_binary (value, (profile[code]).value, strlen(value), VALUE_MAX_SIZE);
      if (rc == -1) { continue; }
      (profile[code]).len = rc;
      (profile[code]).code = code;
      converted = 1;
    }

    if (strcmp(type, "IP") == 0)
    {
      int rc = ip_to_network_byte_order (value, (profile[code]).value, VALUE_MAX_SIZE);
      if (rc == -1) { continue; }
      (profile[code]).len = rc * 4;
      (profile[code]).code = code;
      converted = 1;
    }

    if (converted == 0)
    {
      my_syslog (configuration_globale.log_file,
                 "[WARNING] [%s:%d] Invalid option type (%s) for profile [%s], ignore",
                 __FILE__, __LINE__,
                 type,
                 ((mysql_tables->options)[i]).profile_optionnel);
      continue;
    }
  }
}

/*! \brief Send a DHCPOFFER and log the output packet.
    \author Denis BEURIVE
    \param p Pointer to the incoming packet (should be a DHCP DISCOVER).
    \param mysql_tables pointer to a 'mysql_tables' data structure that contains the loaded client's context.
    \param ip Pointer to a zero terminated string of characters that represents the IP address of the user.
    \param broadcast 4 bytes long integer that contains the binary representation (in network byte order)
           of the broadcast IP address.
    \param server_ip 4 bytes long integer that contains the binary representation (in network byte order)
           of the server IP address.
    \param socket_desc Socket descriptor of the DHCP server.
    \param client_address Pointer to a 'sockaddr_in' data structure that contains the internet address
           of the incoming packet's sender.
           If the configuration tag 'enable-broadcast-responses' is set to "yes", then the parameter
           'client_address' is never used (since the server always send broadcasts).
    \param tip Flag that indicates wether the IP address should be taken from the STATIC pool or the
           dynamic pool. Values can be:
           <ul>
              <li>STATIC_IP (extracted from mysql_tables->abonne_ip.)
              <li>DYNAMIC_IP (extracted from mysql_tables->ip_lease.)
           </ul>
    \return Upon successful completion, the function returns the value 0.
            Otherwise, the function returns the value 1.
 */

int packets_send_offer (
                         struct dhcp_packet    *p,
                         struct mysql_tables   *mysql_tables,
                         char                  *ip,
                         unsigned long int     broadcast,
                         unsigned long int     server_ip,
                         int                   socket_desc,
                         struct sockaddr_in    *client_address,
                         int                   tip)
{
  struct dhcp_packet     packet_out;
  struct sockaddr_in     addr_target;
  int                    adress_size, rc, i;
  char                   *serverip;
  struct opt             options[MAX_PROFILE_OPTIONS];



  packets_clear (&packet_out);
  serverip = configuration_globale.server_ip_seen_by_client;

  /* ------------------------------------------------------------ */
  /* Transfert options from loaded profile (from database) into   */
  /* internal profile representation.                             */
  /* ------------------------------------------------------------ */

  context2profile (options, mysql_tables);

  /* ------------------------------------------------------------ */
  /* Format the OFFER                                             */
  /* Notes:                                                       */
  /* - We don't set 'ciaddr' -> This field will be all zero.      */
  /* - We don't set, 'sname' and 'file' are all zero.             */
  /* ------------------------------------------------------------ */

  packets_set_op           (&packet_out, BOOTREPLY);
  packets_set_htype        (&packet_out, packets_get_htype(p));
  packets_set_hlen         (&packet_out, packets_get_hlen(p));
  packets_set_hops         (&packet_out, 0);
  packets_set_xid          (&packet_out, packets_get_xid(p));
  packets_set_secs         (&packet_out, packets_get_secs(p));
  packets_set_flags        (&packet_out, packets_get_flags(p));
  packets_set_yiaddr       (&packet_out, ip);
  packets_set_siaddr       (&packet_out, configuration_globale.server_ip_seen_by_client);
  packets_set_bin_giaddr   (&packet_out, packets_get_bin_giaddr(p));
  packets_set_chaddr       (&packet_out, packets_get_bin_chaddr(p));

  /* ------------------------------------------------------------ */
  /* Set the correct options' profile                             */
  /*    - lease (already in loaded profile)                       */
  /*    - routers (already in loaded profile)                     */
  /*    - domain name (already in loaded profile)                 */
  /*    - domain name server (already in loaded profile)          */
  /*    - subnet mask (already in loaded profile)                 */
  /*    - message type (added)                                    */
  /*    - server identifier (added)                               */
  /* ------------------------------------------------------------ */

  if (configuration_globale.debug > 1)
  {
    my_syslog (configuration_globale.log_file,
    "[DEBUG] [%s:%d] Add options to DHCP packets", __FILE__, __LINE__);
  }

  /* Message type */
  add_option_to_profile (options, 53, "HEXA-BYTE", DHCPOFFER_HEXA,     strlen(DHCPOFFER_HEXA)); 

  /* Server identifier */
  add_option_to_profile (options, 54, "IP",        serverip,           strlen(serverip)); 

  /* ------------------------------------------------------------ */
  /* if STATIC,                                                   */
  /* get gateway from "mysql_tables->abonne_ip.gateway"           */
  /* if DYNAMIC,                                                  */
  /* get gateway from "mysql_tables->ip_lease.gateway"            */
  /* ------------------------------------------------------------ */

  if (configuration_globale.debug > 1)
  { my_syslog (configuration_globale.log_file,
    "[DEBUG] [%s:%d] tip = %d",
    __FILE__, __LINE__,
    tip);
  }

  if (tip == STATIC_IP)
  {
    add_option_to_profile (options, 3, "IP", mysql_tables->abonne_ip.gateway, 
                           strlen(mysql_tables->abonne_ip.gateway)); 
    add_option_to_profile (options, 1, "IP", mysql_tables->abonne_ip.subnet,
                           strlen(mysql_tables->abonne_ip.subnet));

    if (configuration_globale.debug > 1) 
    { my_syslog (configuration_globale.log_file,
      "[DEBUG] [%s:%d] packets_send_offer: Add gateway and subnet %s %s", 
      __FILE__, __LINE__,
      mysql_tables->abonne_ip.gateway,
      mysql_tables->abonne_ip.subnet); }
  }

  if (tip == DYNAMIC_IP)
  {
    add_option_to_profile (options, 3, "IP", mysql_tables->ip_lease.gateway,
                           strlen(mysql_tables->ip_lease.gateway));
    add_option_to_profile (options, 1, "IP", mysql_tables->ip_lease.subnet,
                           strlen(mysql_tables->ip_lease.subnet));
    if (configuration_globale.debug > 1)
    { my_syslog (configuration_globale.log_file,
      "[DEBUG] [%s:%d] packets_send_offer: Add gateway and subnet %s %s",
      __FILE__, __LINE__,
      mysql_tables->ip_lease.gateway,
      mysql_tables->ip_lease.subnet); }
  }

  /* ------------------------------------------------------------ */
  /* Write packet's options                                       */
  /* ------------------------------------------------------------ */

  for (i=1; i<255; i++)
  {
    if ((options[i]).code != 0)
    {
       packets_set_option (&packet_out, i, (options[i]).value, (options[i]).len);
       if (configuration_globale.debug > 1)
       { my_syslog (configuration_globale.log_file,
         "[DEBUG] [%s:%d] packets_send_offer: Adding option %d", __FILE__, __LINE__, i); }
    }
  }

  packets_close_option (&packet_out);

  /* ------------------------------------------------------------ */
  /* Send it                                                      */
  /* ------------------------------------------------------------ */

  adress_size = sizeof (struct sockaddr);
  memset ((void*)&addr_target, 0, sizeof(struct sockaddr_in));

  if (configuration_globale.broadcast_mode == 1)
  {
    addr_target.sin_family        = AF_INET;
    addr_target.sin_port          = htons(TARGET_PORT);
    (addr_target.sin_addr).s_addr = broadcast;
  }
  else
  { memcpy ((void*)&addr_target, (void*)client_address, sizeof(struct sockaddr_in)); }

  if (configuration_globale.debug > 0)
  { my_syslog (configuration_globale.log_file,
    "[DEBUG] [%s:%d] packets_send_offer: Sending DHCP OFFER for xid %u",
    __FILE__, __LINE__, packets_get_xid(p)); }

  if (configuration_globale.dumper_mode > 0)
  { packet_dump (&packet_out, configuration_globale.debug_file, configuration_globale.csv_file, NULL, &addr_target); }

  #ifndef READ_PACKET_FROM_FILE

    rc = sendto (
                  socket_desc,
                  (void*)&packet_out,
                  packet_out.ctrl.taille,
                  0,
                  (struct sockaddr*)&addr_target,
                  adress_size
                );
  
    if (rc == -1)
    {
      my_syslog (configuration_globale.log_file,
                 "[WARNING] [%s:%d] Could not send OFFER for xid %u - %s",
                 __FILE__, __LINE__,
                 packets_get_xid(p),
                 strerror(errno));
      return 1;
    }

  #else

    my_syslog (configuration_globale.log_file,
               "[INFO] [%s:%d] Reading packet from file => packet no sent (this is normal)",
               __FILE__, __LINE__);

  #endif

  return 0;
}

/*! \brief Send a DHCPACK in response to a REQUEST and log the output packet.
    \author Denis BEURIVE
    \param p Pointer to the incoming packet (should be a DHCP REQUEST).
    \param mysql_tables pointer to a 'mysql_tables' data structure that contains the loaded client's
           context.
    \param ip Pointer to a zero terminated string of characters that represents the client's IP address. 
    \param broadcast 4 bytes long integer that contains the binary representation (in network byte order) of
           the broadcast IP address.
    \param server_ip 4 bytes long integer that contains the binary representation (in network byte order) of
           the server IP address.
    \param socket_desc Socket descriptor of the DHCP server.
    \param client_address Pointer to a 'sockaddr_in' data structure that contains the internet address of the
           incoming packet's sender.
           If the configuration tag 'enable-broadcast-responses' is set to "yes", then the parameter
           'client_address' is never used (since the server always sends broadcasts).
    \param tip Flag that indicates wether the IP address should be taken from the STATIC pool or the
           dynamic pool. Values can be:
           <ul>
              <li>STATIC_IP (extracted from mysql_tables->abonne_ip.)
              <li>DYNAMIC_IP (extracted from mysql_tables->ip_lease.)
           </ul>
    \return Upon successful completion, the function returns the value 0.
            Otherwise, the function returns the value 1.
 */

int packets_send_ack (
                         struct dhcp_packet    *p,
                         struct mysql_tables   *mysql_tables,
                         char                  *ip,
                         unsigned long int     broadcast,
                         unsigned long int     server_ip,
                         int                   socket_desc,
                         struct sockaddr_in    *client_address,
                         int                   tip)
{
  struct dhcp_packet     packet_out;
  struct sockaddr_in     addr_target;
  int                    adress_size, rc, i;
  char                   *serverip;
  struct opt             options[MAX_PROFILE_OPTIONS];


  packets_clear (&packet_out);
  serverip = configuration_globale.server_ip_seen_by_client;

  /* ------------------------------------------------------------ */
  /* Transfert options from loaded profile (from database) into   */
  /* internal profile representation.                             */
  /* ------------------------------------------------------------ */

  context2profile (options, mysql_tables);

  /* ------------------------------------------------------------ */
  /* Format the ACK                                               */
  /* Notes:                                                       */
  /* - We don't set, 'sname' and 'file' are all zero.             */
  /* ------------------------------------------------------------ */

  packets_set_op           (&packet_out, BOOTREPLY);
  packets_set_htype        (&packet_out, packets_get_htype(p));
  packets_set_hlen         (&packet_out, packets_get_hlen(p));
  packets_set_hops         (&packet_out, 0);
  packets_set_xid          (&packet_out, packets_get_xid(p));
  packets_set_secs         (&packet_out, packets_get_secs(p));
  packets_set_flags        (&packet_out, packets_get_flags(p));
  packets_set_yiaddr       (&packet_out, ip);
  packets_set_siaddr       (&packet_out, configuration_globale.server_ip_seen_by_client);
  packets_set_bin_giaddr   (&packet_out, packets_get_bin_giaddr(p));
  packets_set_bin_ciaddr   (&packet_out, packets_get_bin_ciaddr(p));
  packets_set_chaddr       (&packet_out, packets_get_bin_chaddr(p));

  /* ------------------------------------------------------------ */
  /* Set the correct options' profile                             */
  /*    - lease (already in loaded profile)                       */
  /*    - routers (already in loaded profile)                     */
  /*    - domain name (already in loaded profile)                 */
  /*    - domain name server (already in loaded profile)          */
  /*    - subnet mask (already in loaded profile)                 */
  /*    - message type (added)                                    */
  /*    - server identifier (added)                               */
  /* ------------------------------------------------------------ */

  if (configuration_globale.debug > 1)
  { my_syslog (configuration_globale.log_file,
               "[DEBUG] [%s:%d] packets_send_ack: Add option 53 (message type) = 3",
               __FILE__, __LINE__); }

  /* Message type */ 
  add_option_to_profile (options, 53, "HEXA-BYTE", DHCPACK_HEXA, strlen(DHCPACK_HEXA)); 

  if (configuration_globale.debug > 1)
  { my_syslog (configuration_globale.log_file,
               "[DEBUG] [%s:%d] packets_send_ack: Add option 54 (server ID) %s",
               __FILE__, __LINE__, serverip); }

  /* Server Identifier */
  add_option_to_profile (options, 54, "IP", serverip, strlen(serverip)); 

  /* ------------------------------------------------------------ */
  /* if STATIC,                                                   */
  /* get gateway from "mysql_tables->abonne_ip.gateway"           */
  /* if DYNAMIC,                                                  */
  /* get gateway from "mysql_tables->ip_lease.gateway"            */
  /* ------------------------------------------------------------ */

  if (configuration_globale.debug > 1)
  { my_syslog (configuration_globale.log_file,
    "[DEBUG] [%s:%d] tip = %d",
    __FILE__, __LINE__,
    tip);
  }

  if (tip == STATIC_IP)
  {
    add_option_to_profile (options, 3, "IP", mysql_tables->abonne_ip.gateway,
                           strlen(mysql_tables->abonne_ip.gateway));
    add_option_to_profile (options, 1, "IP", mysql_tables->abonne_ip.subnet,
                           strlen(mysql_tables->abonne_ip.subnet));

    if (configuration_globale.debug > 1)
    { my_syslog (configuration_globale.log_file,
      "[DEBUG] [%s:%d] packets_send_offer: Add gateway and subnet %s %s",
      __FILE__, __LINE__,
      mysql_tables->abonne_ip.gateway,
      mysql_tables->abonne_ip.subnet); }
  }

  if (tip == DYNAMIC_IP)
  {
    add_option_to_profile (options, 3, "IP", mysql_tables->ip_lease.gateway,
                           strlen(mysql_tables->ip_lease.gateway));
    add_option_to_profile (options, 1, "IP", mysql_tables->ip_lease.subnet,
                           strlen(mysql_tables->ip_lease.subnet));
    if (configuration_globale.debug > 1)
    { my_syslog (configuration_globale.log_file,
      "[DEBUG] [%s:%d] packets_send_offer: Add gateway and subnet %s %s",
      __FILE__, __LINE__,
      mysql_tables->ip_lease.gateway,
      mysql_tables->ip_lease.subnet); }
  }

  /* ------------------------------------------------------------ */
  /* Write packet's options                                       */
  /* ------------------------------------------------------------ */

  for (i=1; i<255; i++)
  {
    if ((options[i]).code != 0)
    {
       if (configuration_globale.debug > 1)
       { my_syslog (configuration_globale.log_file,
         "[DEBUG] [%s:%d] packets_send_ack: Adding option %d", __FILE__, __LINE__, i); }
       packets_set_option (&packet_out, i, (options[i]).value, (options[i]).len);
    }
  }

  packets_close_option (&packet_out);

  /* ------------------------------------------------------------ */
  /* Send it                                                      */
  /* ------------------------------------------------------------ */

  memset ((void*)&addr_target, 0, sizeof(struct sockaddr_in));
  adress_size = sizeof (struct sockaddr);

  if (configuration_globale.broadcast_mode == 1)
  {
     addr_target.sin_family        = AF_INET;
     addr_target.sin_port          = htons(TARGET_PORT);
     (addr_target.sin_addr).s_addr = broadcast;
  }
  else
  { memcpy ((void*)&addr_target, (void*)client_address, sizeof(struct sockaddr_in)); }

  if (configuration_globale.debug > 0)
  { my_syslog (configuration_globale.log_file,
    "[DEBUG] [%s:%d] packets_send_ack: Sending DHCP ACK for xid %u",
    __FILE__, __LINE__, packets_get_xid(p)); }


  if (configuration_globale.dumper_mode > 0)
  { packet_dump (&packet_out, configuration_globale.debug_file, configuration_globale.csv_file, NULL, &addr_target); }

  #ifndef READ_PACKET_FROM_FILE

  rc = sendto (
                socket_desc,
                (void*)&packet_out,
                packet_out.ctrl.taille,
                0,
                (struct sockaddr*)&addr_target,
                adress_size
              );

  if (rc == -1)
  {
    my_syslog (configuration_globale.log_file, "[WARNING] [%s:%d] Could not send ACK for xid %u - %s",
               __FILE__, __LINE__,
               packets_get_xid(p),
               strerror(errno));
    return 1;
  }

  #else

    my_syslog (configuration_globale.log_file,
               "[INFO] [%s:%d] Reading packet from file => packet no sent (this is normal)",
               __FILE__, __LINE__);

  #endif

  return 0;
}

/*! \brief Log a packet's profile (list of options) in a human readables format.
    \author Denis BEURIVE
    \param file Pointer to a zero terminated string of characters that represents the path to the log file.
    \param mes Pointer to a zero terminated string of characters that represents a text that will be printed
           before the profile.
    \param profile pointer to a opt data structure that contains the profile to print.
    \return Upon successful completion, the function returns the value 0. Othrwise, the function returns the
            value 1.
 */

int log_profile (const char *file, const char *mes, const struct opt *profile)
{
        int             i, l;
        FILE            *fd;
        unsigned char   *c;

        fd = fopen (file, "a");
        if (fd == NULL) { return 1; }

        fprintf (fd, "%s %s ", dater(), mes);

        for (i=0; i<256; i++)
        {
          if ((profile[i]).code != 0)
          {
            fprintf (fd, "(%d) %d [", (profile[i]).code, (profile[i]).len);
            c = (unsigned char*)(profile[i]).value;
            for (l=0; l<(profile[i]).len; l++)
            {
              fprintf (fd, "%c%c", int_to_char (((*c) & 0xF0) >> 4), int_to_char ((*c) & 0x0F));
              if (l < (profile[i]).len - 1) { fprintf (fd, "."); }
              c += 1;
            }
            fprintf (fd, "]  ");
          }
        }
        fprintf (fd, "\n");

        fclose (fd);
        return 0;
}


/*! \brief Send a DHCPACK as response to an INFORM.
    \author Denis BEURIVE
    \param p Pointer to the incoming packet (should be a DHCP INFORM).
    \param mysql_tables pointer to a 'mysql_tables' data structure that contains the loaded client's context.
    \param broadcast 4 bytes long integer that contains the binary representation (in network byte order)
           of the broadcast IP address.
    \param server_ip 4 bytes long integer that contains the binary representation (in network byte order)
           of the server IP address.
    \param socket_desc Socket descriptor of the DHCP server.
    \param client_address Pointer to a 'sockaddr_in' data structure that contains the internet address of
           the incoming packet's sender.
           If the configuration tag 'enable-broadcast-responses' is set to "yes", then the parameter
           'client_address' is never used (since the server always send broadcasts).
    \return Upon successful completion, the function returns the value 0.
            Otherwise, the function returns the value 1.
 */

int reply_to_inform (
                      struct dhcp_packet    *p,
                      struct mysql_tables   *mysql_tables,
                      unsigned long int     broadcast,
                      unsigned long int     server_ip,
                      int                   socket_desc,
                      struct sockaddr_in    *client_address)
{
  struct dhcp_packet     packet_out;
  struct sockaddr_in     addr_target;
  int                    adress_size, rc, i;
  char                   *serverip;
  struct opt             options[MAX_PROFILE_OPTIONS];

  packets_clear (&packet_out);
  serverip = configuration_globale.server_ip_seen_by_client;

  /* ------------------------------------------------------------ */
  /* Transfert options from loaded profile (from database) into   */
  /* internal profile representation.                             */
  /* ------------------------------------------------------------ */

  context2profile (options, mysql_tables);

  /* ------------------------------------------------------------ */
  /* Format the ACK                                               */
  /* Notes:                                                       */
  /* - We don't set  'yiaddr' -> This field will be all zero.     */
  /* - We don't set, 'sname' and 'file' are all zero.             */
  /* ------------------------------------------------------------ */

  packets_set_op           (&packet_out, BOOTREPLY);
  packets_set_htype        (&packet_out, packets_get_htype(p));
  packets_set_hlen         (&packet_out, packets_get_hlen(p));
  packets_set_hops         (&packet_out, 0);
  packets_set_xid          (&packet_out, packets_get_xid(p));
  packets_set_secs         (&packet_out, packets_get_secs(p));
  packets_set_flags        (&packet_out, packets_get_flags(p));
  packets_set_siaddr       (&packet_out, configuration_globale.server_ip_seen_by_client);
  packets_set_bin_giaddr   (&packet_out, packets_get_bin_giaddr(p));
  packets_set_bin_ciaddr   (&packet_out, packets_get_bin_ciaddr(p));
  packets_set_chaddr       (&packet_out, packets_get_bin_chaddr(p));

  /* ------------------------------------------------------------ */
  /* Set the correct options' profile                             */
  /*    - routers (already in loaded profile)                     */
  /*    - domain name (already in loaded profile)                 */
  /*    - domain name server (already in loaded profile)          */
  /*    - subnet mask (already in loaded profile)                 */
  /*    - message type (added)                                    */
  /*    - server identifier (added)                               */
  /*                                                              */
  /* Note: remove lease from option's profile.                    */
  /* ------------------------------------------------------------ */

  add_option_to_profile (options, 53, "HEXA-BYTE", DHCPACK_HEXA, strlen(DHCPACK_HEXA)); /* Message type       */
  add_option_to_profile (options, 54, "IP",        serverip,     strlen(serverip));     /* Server Identifier  */
  
  remove_option_from_profile (options, 51);

  /* ------------------------------------------------------------ */
  /* Write packet's options                                       */
  /* ------------------------------------------------------------ */

  for (i=1; i<255; i++)
  {
    if ((options[i]).code != 0)
    {
       packets_set_option (&packet_out, i, (options[i]).value, (options[i]).len);
       if (configuration_globale.debug > 1)
       { my_syslog (configuration_globale.log_file,
         "[DEBUG] [%s:%d] packets_send_ack: Adding option %d", __FILE__, __LINE__, i); }
    }
  }

  packets_close_option (&packet_out);

  /* ------------------------------------------------------------ */
  /* Send it                                                      */
  /* ------------------------------------------------------------ */

  adress_size = sizeof (struct sockaddr);
  memset ((void*)&addr_target, 0, sizeof(struct sockaddr_in));

  if (configuration_globale.broadcast_mode == 1)
  {
    addr_target.sin_family        = AF_INET;
    addr_target.sin_port          = htons(TARGET_PORT);
    (addr_target.sin_addr).s_addr = broadcast;
  }
  else
  { memcpy ((void*)&addr_target, (void*)client_address, sizeof(struct sockaddr_in)); }

  if (configuration_globale.debug > 0)
  { my_syslog (configuration_globale.log_file,
    "[DEBUG] [%s:%d] packets_send_offer: Sending DHCP OFFER for xid %u",
    __FILE__, __LINE__, packets_get_xid(p)); }

  if (configuration_globale.dumper_mode > 0)
  { packet_dump (&packet_out, configuration_globale.debug_file, configuration_globale.csv_file, NULL, &addr_target); }

  #ifndef READ_PACKET_FROM_FILE

  rc = sendto (
                socket_desc,
                (void*)&packet_out,
                packet_out.ctrl.taille,
                0,
                (struct sockaddr*)&addr_target,
                adress_size
              );

  if (rc == -1)
  {
    my_syslog (configuration_globale.log_file,
               "[WARNING] [%s:%d] Could not send OFFER for xid %u - %s",
               __FILE__, __LINE__,
               packets_get_xid(p),
               strerror(errno));
    return 1;
  }

  #else

    my_syslog (configuration_globale.log_file,
               "[INFO] [%s:%d] Reading packet from file => packet no sent (this is normal)",
               __FILE__, __LINE__);

  #endif

  return 0;
}

/*! \brief Send a DHCPNAK in response to a REQUEST and log the output packet.
    \author Denis BEURIVE
    \param p Pointer to the incoming packet (should be a DHCP REQUEST).
    \param mysql_tables pointer to a 'mysql_tables' data structure that contains the loaded client's
           context.
    \param ip Pointer to a zero terminated string of characters that represents the client's IP address.
    \param broadcast 4 bytes long integer that contains the binary representation (in network byte order) of
           the broadcast IP address.
    \param server_ip 4 bytes long integer that contains the binary representation (in network byte order) of
           the server IP address.
    \param socket_desc Socket descriptor of the DHCP server.
    \param client_address Pointer to a 'sockaddr_in' data structure that contains the internet address of the
           incoming packet's sender.
           If the configuration tag 'enable-broadcast-responses' is set to "yes", then the parameter
           'client_address' is never used (since the server always sends broadcasts).
    \return Upon successful completion, the function returns the value 0.
            Otherwise, the function returns the value 1.
 */

int packets_send_nack (
                         struct dhcp_packet    *p,
                         struct mysql_tables   *mysql_tables,
                         char                  *ip,
                         unsigned long int     broadcast,
                         unsigned long int     server_ip,
                         int                   socket_desc,
                         struct sockaddr_in    *client_address)
{
  struct dhcp_packet     packet_out;
  struct sockaddr_in     addr_target;
  int                    adress_size, rc, i;
  char                   *serverip;
  struct opt             options[MAX_PROFILE_OPTIONS];

  packets_clear (&packet_out);
  serverip = configuration_globale.server_ip_seen_by_client;

  /* ------------------------------------------------------------ */
  /* Initialize the list of options                               */
  /* ------------------------------------------------------------ */

  clear_profile(options);

  /* ------------------------------------------------------------ */
  /* Format the NAK                                               */
  /* ------------------------------------------------------------ */

  packets_set_op           (&packet_out, BOOTREPLY);
  packets_set_htype        (&packet_out, packets_get_htype(p));
  packets_set_hlen         (&packet_out, packets_get_hlen(p));
  packets_set_hops         (&packet_out, 0);
  packets_set_xid          (&packet_out, packets_get_xid(p));
  packets_set_secs         (&packet_out, packets_get_secs(p));
  packets_set_flags        (&packet_out, packets_get_flags(p));
  packets_set_yiaddr       (&packet_out, ip);
  packets_set_siaddr       (&packet_out, configuration_globale.server_ip_seen_by_client);
  packets_set_bin_giaddr   (&packet_out, packets_get_bin_giaddr(p));
  packets_set_bin_ciaddr   (&packet_out, packets_get_bin_ciaddr(p));
  packets_set_chaddr       (&packet_out, packets_get_bin_chaddr(p));

  /* ------------------------------------------------------------ */
  /* Set the type of the response (in this case, a DHCPNAK)       */
  /* ------------------------------------------------------------ */

  if (configuration_globale.debug > 1)
  { my_syslog (configuration_globale.log_file,
               "[DEBUG] [%s:%d] packets_send_nack: Add option 53 (message type) = 6",
               __FILE__, __LINE__); }

  add_option_to_profile (options, 53, "HEXA-BYTE", DHCPNAK_HEXA, strlen(DHCPNAK_HEXA)); 

  /* ------------------------------------------------------------ */
  /* Set the IP address of the DHCP server (for futur requests)   */
  /* ------------------------------------------------------------ */

  if (configuration_globale.debug > 1)
  { my_syslog (configuration_globale.log_file,
               "[DEBUG] [%s:%d] packets_send_nack: Add option 54 (server ID) %s",
               __FILE__, __LINE__, serverip); }

  add_option_to_profile (options, 54, "IP", serverip, strlen(serverip)); 

  /* ------------------------------------------------------------ */
  /* Write packet's options                                       */
  /* ------------------------------------------------------------ */

  for (i=1; i<255; i++)
  {
    if ((options[i]).code != 0)
    {
       if (configuration_globale.debug > 1)
       { my_syslog (configuration_globale.log_file,
         "[DEBUG] [%s:%d] packets_send_nack: Adding option %d", __FILE__, __LINE__, i); }
       packets_set_option (&packet_out, i, (options[i]).value, (options[i]).len);
    }
  }

  /* ------------------------------------------------------------ */
  /* Send it                                                      */
  /* ------------------------------------------------------------ */

  packets_close_option (&packet_out);

  memset ((void*)&addr_target, 0, sizeof(struct sockaddr_in));
  adress_size = sizeof (struct sockaddr);

  if (configuration_globale.broadcast_mode == 1)
  {
     addr_target.sin_family        = AF_INET;
     addr_target.sin_port          = htons(TARGET_PORT);
     (addr_target.sin_addr).s_addr = broadcast;
  }
  else
  { memcpy ((void*)&addr_target, (void*)client_address, sizeof(struct sockaddr_in)); }

  if (configuration_globale.debug > 0)
  { my_syslog (configuration_globale.log_file,
    "[DEBUG] [%s:%d] packets_send_nack: Sending DHCP NACK for xid %u",
    __FILE__, __LINE__, packets_get_xid(p)); }

  if (configuration_globale.dumper_mode > 0)
  { packet_dump (&packet_out, configuration_globale.debug_file, configuration_globale.csv_file, NULL, &addr_target); }

  #ifndef READ_PACKET_FROM_FILE

    /* ---------------------------------------------------------- */
    /* This is not a simulation, send the response                */
    /* ---------------------------------------------------------- */

    rc = sendto (
                  socket_desc,
                  (void*)&packet_out,
                  packet_out.ctrl.taille,
                  0,
                  (struct sockaddr*)&addr_target,
                  adress_size
                );
  
    if (rc == -1)
    {
      my_syslog (configuration_globale.log_file,
                 "[WARNING] [%s:%d] Could not send NAK for xid %u - %s",
                 __FILE__, __LINE__,
                 packets_get_xid(p),
                 strerror(errno));
      return 1;
    }

  #else

    /* ---------------------------------------------------------- */
    /* This is a simulation, do not send any response             */
    /* ---------------------------------------------------------- */

    my_syslog (configuration_globale.log_file,
               "[INFO] [%s:%d] Reading packet from file => packet (NAK) not sent (simulation)",
               __FILE__, __LINE__);

  #endif

  return 0;
}

/*! \brief Send a dummy DHCPNAK and log the output packet.
    \author Denis BEURIVE
    \param p Pointer to the incoming packet (should be a DHCP REQUEST).
    \param mysql_tables pointer to a 'mysql_tables' data structure that contains the loaded client's
           context.
    \param ip Pointer to a zero terminated string of characters that represents the client's IP address.
    \param broadcast 4 bytes long integer that contains the binary representation (in network byte order) of
           the broadcast IP address.
    \param server_ip 4 bytes long integer that contains the binary representation (in network byte order) of
           the server IP address.
    \param socket_desc Socket descriptor of the DHCP server.
    \param client_address Pointer to a 'sockaddr_in' data structure that contains the internet address of the
           incoming packet's sender.
           If the configuration tag 'enable-broadcast-responses' is set to "yes", then the parameter
           'client_address' is never used (since the server always sends broadcasts).
    \return Upon successful completion, the function returns the value 0.
            Otherwise, the function returns the value 1.
 */

int packets_send_dummy_nak (
                             struct dhcp_packet    *p,
                             struct mysql_tables   *mysql_tables,
                             char                  *ip,
                             unsigned long int     broadcast,
                             unsigned long int     server_ip,
                             int                   socket_desc,
                             struct sockaddr_in    *client_address)
{
  int cr;

  my_syslog (configuration_globale.log_file,
             "[DUMMY RESPONSE] [%s:%d] packets_send_dummy_nak: Sending DUMMY DHCPNAK",
             __FILE__, __LINE__);

  cr = packets_send_nack ( p,
                           mysql_tables,
                           ip,
                           broadcast,
                           server_ip,
                           socket_desc,
                           client_address);

  if (cr == 1)
  {
    my_syslog (configuration_globale.log_file,
               "[ERROR] [%s:%d] packets_send_dummy_nak: Could not send the DUMMY DHCPNAK",
               __FILE__, __LINE__);
    return 1;
  }

  return 0;
}

---