dhcp.h

00001 /**
00002  * @file
00003  * DHCP protocol definitions
00004  */
00005 
00006 /*
00007  * Copyright (c) 2001-2004 Leon Woestenberg <leon.woestenberg@gmx.net>
00008  * Copyright (c) 2001-2004 Axon Digital Design B.V., The Netherlands.
00009  * All rights reserved.
00010  *
00011  * Redistribution and use in source and binary forms, with or without modification,
00012  * are permitted provided that the following conditions are met:
00013  *
00014  * 1. Redistributions of source code must retain the above copyright notice,
00015  *    this list of conditions and the following disclaimer.
00016  * 2. Redistributions in binary form must reproduce the above copyright notice,
00017  *    this list of conditions and the following disclaimer in the documentation
00018  *    and/or other materials provided with the distribution.
00019  * 3. The name of the author may not be used to endorse or promote products
00020  *    derived from this software without specific prior written permission.
00021  *
00022  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
00023  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
00024  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
00025  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
00026  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
00027  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00028  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
00029  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
00030  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
00031  * OF SUCH DAMAGE.
00032  *
00033  * This file is part of the lwIP TCP/IP stack.
00034  *
00035  * Author: Leon Woestenberg <leon.woestenberg@gmx.net>
00036  *
00037  */
00038 #ifndef LWIP_HDR_PROT_DHCP_H
00039 #define LWIP_HDR_PROT_DHCP_H
00040 
00041 #include "lwip/opt.h"
00042 #include "lwip/arch.h"
00043 #include "lwip/prot/ip4.h"
00044 
00045 #ifdef __cplusplus
00046 extern "C" {
00047 #endif
00048 
00049  /* DHCP message item offsets and length */
00050 #define DHCP_CHADDR_LEN   16U
00051 #define DHCP_SNAME_OFS    44U
00052 #define DHCP_SNAME_LEN    64U
00053 #define DHCP_FILE_OFS     108U
00054 #define DHCP_FILE_LEN     128U
00055 #define DHCP_MSG_LEN      236U
00056 #define DHCP_OPTIONS_OFS  (DHCP_MSG_LEN + 4U) /* 4 byte: cookie */
00057 
00058 #ifdef PACK_STRUCT_USE_INCLUDES
00059 #  include "arch/bpstruct.h"
00060 #endif
00061 PACK_STRUCT_BEGIN
00062 /** minimum set of fields of any DHCP message */
00063 struct dhcp_msg
00064 {
00065   PACK_STRUCT_FLD_8(u8_t op);
00066   PACK_STRUCT_FLD_8(u8_t htype);
00067   PACK_STRUCT_FLD_8(u8_t hlen);
00068   PACK_STRUCT_FLD_8(u8_t hops);
00069   PACK_STRUCT_FIELD(u32_t xid);
00070   PACK_STRUCT_FIELD(u16_t secs);
00071   PACK_STRUCT_FIELD(u16_t flags);
00072   PACK_STRUCT_FLD_S(ip4_addr_p_t ciaddr);
00073   PACK_STRUCT_FLD_S(ip4_addr_p_t yiaddr);
00074   PACK_STRUCT_FLD_S(ip4_addr_p_t siaddr);
00075   PACK_STRUCT_FLD_S(ip4_addr_p_t giaddr);
00076   PACK_STRUCT_FLD_8(u8_t chaddr[DHCP_CHADDR_LEN]);
00077   PACK_STRUCT_FLD_8(u8_t sname[DHCP_SNAME_LEN]);
00078   PACK_STRUCT_FLD_8(u8_t file[DHCP_FILE_LEN]);
00079   PACK_STRUCT_FIELD(u32_t cookie);
00080 #define DHCP_MIN_OPTIONS_LEN 68U
00081 /** make sure user does not configure this too small */
00082 #if ((defined(DHCP_OPTIONS_LEN)) && (DHCP_OPTIONS_LEN < DHCP_MIN_OPTIONS_LEN))
00083 #  undef DHCP_OPTIONS_LEN
00084 #endif
00085 /** allow this to be configured in lwipopts.h, but not too small */
00086 #if (!defined(DHCP_OPTIONS_LEN))
00087 /** set this to be sufficient for your options in outgoing DHCP msgs */
00088 #  define DHCP_OPTIONS_LEN DHCP_MIN_OPTIONS_LEN
00089 #endif
00090   PACK_STRUCT_FLD_8(u8_t options[DHCP_OPTIONS_LEN]);
00091 } PACK_STRUCT_STRUCT;
00092 PACK_STRUCT_END
00093 #ifdef PACK_STRUCT_USE_INCLUDES
00094 #  include "arch/epstruct.h"
00095 #endif
00096 
00097 
00098 /* DHCP client states */
00099 typedef enum {
00100   DHCP_STATE_OFF             = 0,
00101   DHCP_STATE_REQUESTING      = 1,
00102   DHCP_STATE_INIT            = 2,
00103   DHCP_STATE_REBOOTING       = 3,
00104   DHCP_STATE_REBINDING       = 4,
00105   DHCP_STATE_RENEWING        = 5,
00106   DHCP_STATE_SELECTING       = 6,
00107   DHCP_STATE_INFORMING       = 7,
00108   DHCP_STATE_CHECKING        = 8,
00109   DHCP_STATE_PERMANENT       = 9,  /* not yet implemented */
00110   DHCP_STATE_BOUND           = 10,
00111   DHCP_STATE_RELEASING       = 11, /* not yet implemented */
00112   DHCP_STATE_BACKING_OFF     = 12
00113 } dhcp_state_enum_t;
00114 
00115 /* DHCP op codes */
00116 #define DHCP_BOOTREQUEST            1
00117 #define DHCP_BOOTREPLY              2
00118 
00119 /* DHCP message types */
00120 #define DHCP_DISCOVER               1
00121 #define DHCP_OFFER                  2
00122 #define DHCP_REQUEST                3
00123 #define DHCP_DECLINE                4
00124 #define DHCP_ACK                    5
00125 #define DHCP_NAK                    6
00126 #define DHCP_RELEASE                7
00127 #define DHCP_INFORM                 8
00128 
00129 #define DHCP_MAGIC_COOKIE           0x63825363UL
00130 
00131 /* This is a list of options for BOOTP and DHCP, see RFC 2132 for descriptions */
00132 
00133 /* BootP options */
00134 #define DHCP_OPTION_PAD             0
00135 #define DHCP_OPTION_SUBNET_MASK     1 /* RFC 2132 3.3 */
00136 #define DHCP_OPTION_ROUTER          3
00137 #define DHCP_OPTION_DNS_SERVER      6
00138 #define DHCP_OPTION_HOSTNAME        12
00139 #define DHCP_OPTION_IP_TTL          23
00140 #define DHCP_OPTION_MTU             26
00141 #define DHCP_OPTION_BROADCAST       28
00142 #define DHCP_OPTION_TCP_TTL         37
00143 #define DHCP_OPTION_NTP             42
00144 #define DHCP_OPTION_END             255
00145 
00146 /* DHCP options */
00147 #define DHCP_OPTION_REQUESTED_IP    50 /* RFC 2132 9.1, requested IP address */
00148 #define DHCP_OPTION_LEASE_TIME      51 /* RFC 2132 9.2, time in seconds, in 4 bytes */
00149 #define DHCP_OPTION_OVERLOAD        52 /* RFC2132 9.3, use file and/or sname field for options */
00150 
00151 #define DHCP_OPTION_MESSAGE_TYPE    53 /* RFC 2132 9.6, important for DHCP */
00152 #define DHCP_OPTION_MESSAGE_TYPE_LEN 1
00153 
00154 #define DHCP_OPTION_SERVER_ID       54 /* RFC 2132 9.7, server IP address */
00155 #define DHCP_OPTION_PARAMETER_REQUEST_LIST  55 /* RFC 2132 9.8, requested option types */
00156 
00157 #define DHCP_OPTION_MAX_MSG_SIZE    57 /* RFC 2132 9.10, message size accepted >= 576 */
00158 #define DHCP_OPTION_MAX_MSG_SIZE_LEN 2
00159 
00160 #define DHCP_OPTION_T1              58 /* T1 renewal time */
00161 #define DHCP_OPTION_T2              59 /* T2 rebinding time */
00162 #define DHCP_OPTION_US              60
00163 #define DHCP_OPTION_CLIENT_ID       61
00164 #define DHCP_OPTION_TFTP_SERVERNAME 66
00165 #define DHCP_OPTION_BOOTFILE        67
00166 
00167 /* possible combinations of overloading the file and sname fields with options */
00168 #define DHCP_OVERLOAD_NONE          0
00169 #define DHCP_OVERLOAD_FILE          1
00170 #define DHCP_OVERLOAD_SNAME         2
00171 #define DHCP_OVERLOAD_SNAME_FILE    3
00172 
00173 
00174 #ifdef __cplusplus
00175 }
00176 #endif
00177 
00178 #endif /* LWIP_HDR_PROT_DHCP_H */