text: /**
   * @file
   * DHCP protocol definitions
   */
  
  /*
   * Copyright (c) 2001-2004 Leon Woestenberg <leon.woestenberg@gmx.net>
   * Copyright (c) 2001-2004 Axon Digital Design B.V., The Netherlands.
   * 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. 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.
   *
   * This file is part of the lwIP TCP/IP stack.
   *
   * Author: Leon Woestenberg <leon.woestenberg@gmx.net>
   *
   */
  #ifndef LWIP_HDR_PROT_DHCP_H
  #define LWIP_HDR_PROT_DHCP_H
  
  #include "lwip/opt.h"
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  #define DHCP_CLIENT_PORT  68
  #define DHCP_SERVER_PORT  67
  
  
   /* DHCP message item offsets and length */
  #define DHCP_CHADDR_LEN   16U
  #define DHCP_SNAME_OFS    44U
  #define DHCP_SNAME_LEN    64U
  #define DHCP_FILE_OFS     108U
  #define DHCP_FILE_LEN     128U
  #define DHCP_MSG_LEN      236U
  #define DHCP_OPTIONS_OFS  (DHCP_MSG_LEN + 4U) /* 4 byte: cookie */
  
  #ifdef PACK_STRUCT_USE_INCLUDES
  #  include "arch/bpstruct.h"
  #endif
  PACK_STRUCT_BEGIN
  /** minimum set of fields of any DHCP message */
  struct dhcp_msg
  {
    PACK_STRUCT_FLD_8(u8_t op);
    PACK_STRUCT_FLD_8(u8_t htype);
    PACK_STRUCT_FLD_8(u8_t hlen);
    PACK_STRUCT_FLD_8(u8_t hops);
    PACK_STRUCT_FIELD(u32_t xid);
    PACK_STRUCT_FIELD(u16_t secs);
    PACK_STRUCT_FIELD(u16_t flags);
    PACK_STRUCT_FLD_S(ip4_addr_p_t ciaddr);
    PACK_STRUCT_FLD_S(ip4_addr_p_t yiaddr);
    PACK_STRUCT_FLD_S(ip4_addr_p_t siaddr);
    PACK_STRUCT_FLD_S(ip4_addr_p_t giaddr);
    PACK_STRUCT_FLD_8(u8_t chaddr[DHCP_CHADDR_LEN]);
    PACK_STRUCT_FLD_8(u8_t sname[DHCP_SNAME_LEN]);
    PACK_STRUCT_FLD_8(u8_t file[DHCP_FILE_LEN]);
    PACK_STRUCT_FIELD(u32_t cookie);
  #define DHCP_MIN_OPTIONS_LEN 68U
  /** make sure user does not configure this too small */
  #if ((defined(DHCP_OPTIONS_LEN)) && (DHCP_OPTIONS_LEN < DHCP_MIN_OPTIONS_LEN))
  #  undef DHCP_OPTIONS_LEN
  #endif
  /** allow this to be configured in lwipopts.h, but not too small */
  #if (!defined(DHCP_OPTIONS_LEN))
  /** set this to be sufficient for your options in outgoing DHCP msgs */
  #  define DHCP_OPTIONS_LEN DHCP_MIN_OPTIONS_LEN
  #endif
    PACK_STRUCT_FLD_8(u8_t options[DHCP_OPTIONS_LEN]);
  } PACK_STRUCT_STRUCT;
  PACK_STRUCT_END
  #ifdef PACK_STRUCT_USE_INCLUDES
  #  include "arch/epstruct.h"
  #endif
  
  
  /* DHCP client states */
  typedef enum {
    DHCP_STATE_OFF             = 0,
    DHCP_STATE_REQUESTING      = 1,
    DHCP_STATE_INIT            = 2,
    DHCP_STATE_REBOOTING       = 3,
    DHCP_STATE_REBINDING       = 4,
    DHCP_STATE_RENEWING        = 5,
    DHCP_STATE_SELECTING       = 6,
    DHCP_STATE_INFORMING       = 7,
    DHCP_STATE_CHECKING        = 8,
    DHCP_STATE_PERMANENT       = 9,  /* not yet implemented */
    DHCP_STATE_BOUND           = 10,
    DHCP_STATE_RELEASING       = 11, /* not yet implemented */
    DHCP_STATE_BACKING_OFF     = 12,
  #ifdef DHCP_REBIND_PRE_ADDR
    DHCP_STATE_PRE_REQUESTING = 13,
  #endif
  } dhcp_state_enum_t;
  
  /* DHCP op codes */
  #define DHCP_BOOTREQUEST            1
  #define DHCP_BOOTREPLY              2
  
  /* DHCP message types */
  #define DHCP_DISCOVER               1
  #define DHCP_OFFER                  2
  #define DHCP_REQUEST                3
  #define DHCP_DECLINE                4
  #define DHCP_ACK                    5
  #define DHCP_NAK                    6
  #define DHCP_RELEASE                7
  #define DHCP_INFORM                 8
  
  /** DHCP hardware type, currently only ethernet is supported */
  #define DHCP_HTYPE_ETH              1
  
  #define DHCP_MAGIC_COOKIE           0x63825363UL
  
  /* This is a list of options for BOOTP and DHCP, see RFC 2132 for descriptions */
  
  /* BootP options */
  #define DHCP_OPTION_PAD             0
  #define DHCP_OPTION_SUBNET_MASK     1 /* RFC 2132 3.3 */
  #define DHCP_OPTION_ROUTER          3
  #define DHCP_OPTION_DNS_SERVER      6
  #define DHCP_OPTION_HOSTNAME        12
  #define DHCP_OPTION_IP_TTL          23
  #define DHCP_OPTION_MTU             26
  #define DHCP_OPTION_BROADCAST       28
  #define DHCP_OPTION_TCP_TTL         37
  #define DHCP_OPTION_NTP             42
  #define DHCP_OPTION_END             255
  
  /* DHCP options */
  #define DHCP_OPTION_REQUESTED_IP    50 /* RFC 2132 9.1, requested IP address */
  #define DHCP_OPTION_LEASE_TIME      51 /* RFC 2132 9.2, time in seconds, in 4 bytes */
  #define DHCP_OPTION_OVERLOAD        52 /* RFC2132 9.3, use file and/or sname field for options */
  
  #define DHCP_OPTION_MESSAGE_TYPE    53 /* RFC 2132 9.6, important for DHCP */
  #define DHCP_OPTION_MESSAGE_TYPE_LEN 1
  
  #define DHCP_OPTION_SERVER_ID       54 /* RFC 2132 9.7, server IP address */
  #define DHCP_OPTION_PARAMETER_REQUEST_LIST  55 /* RFC 2132 9.8, requested option types */
  
  #define DHCP_OPTION_MAX_MSG_SIZE    57 /* RFC 2132 9.10, message size accepted >= 576 */
  #define DHCP_OPTION_MAX_MSG_SIZE_LEN 2
  
  #define DHCP_OPTION_T1              58 /* T1 renewal time */
  #define DHCP_OPTION_T2              59 /* T2 rebinding time */
  #define DHCP_OPTION_US              60
  #define DHCP_OPTION_CLIENT_ID       61
  #define DHCP_OPTION_TFTP_SERVERNAME 66
  #define DHCP_OPTION_BOOTFILE        67
  
  /* possible combinations of overloading the file and sname fields with options */
  #define DHCP_OVERLOAD_NONE          0
  #define DHCP_OVERLOAD_FILE          1
  #define DHCP_OVERLOAD_SNAME         2
  #define DHCP_OVERLOAD_SNAME_FILE    3
  
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif /*LWIP_HDR_PROT_DHCP_H*/
  