dhcp.h

00001 /** @file
00002  */
00003 
00004 #ifndef __LWIP_DHCP_H__
00005 #define __LWIP_DHCP_H__
00006 
00007 #include "lwip/opt.h"
00008 
00009 #if LWIP_DHCP /* don't build if not configured for use in lwipopts.h */
00010 
00011 #include "lwip/netif.h"
00012 #include "lwip/udp.h"
00013 
00014 #ifdef __cplusplus
00015 extern "C" {
00016 #endif
00017 
00018 /** period (in seconds) of the application calling dhcp_coarse_tmr() */
00019 #define DHCP_COARSE_TIMER_SECS 60 
00020 /** period (in milliseconds) of the application calling dhcp_coarse_tmr() */
00021 #define DHCP_COARSE_TIMER_MSECS (DHCP_COARSE_TIMER_SECS * 1000UL)
00022 /** period (in milliseconds) of the application calling dhcp_fine_tmr() */
00023 #define DHCP_FINE_TIMER_MSECS 500 
00024 
00025 #define DHCP_CHADDR_LEN 16U
00026 #define DHCP_SNAME_LEN  64U
00027 #define DHCP_FILE_LEN   128U
00028 
00029 struct dhcp
00030 {
00031   /** transaction identifier of last sent request */ 
00032   u32_t xid;
00033   /** our connection to the DHCP server */ 
00034   struct udp_pcb *pcb;
00035   /** incoming msg */
00036   struct dhcp_msg *msg_in;
00037   /** current DHCP state machine state */
00038   u8_t state;
00039   /** retries of current request */
00040   u8_t tries;
00041 #if LWIP_DHCP_AUTOIP_COOP
00042   u8_t autoip_coop_state;
00043 #endif
00044   u8_t subnet_mask_given;
00045 
00046   struct pbuf *p_out; /* pbuf of outcoming msg */
00047   struct dhcp_msg *msg_out; /* outgoing msg */
00048   u16_t options_out_len; /* outgoing msg options length */
00049   u16_t request_timeout; /* #ticks with period DHCP_FINE_TIMER_SECS for request timeout */
00050   u16_t t1_timeout;  /* #ticks with period DHCP_COARSE_TIMER_SECS for renewal time */
00051   u16_t t2_timeout;  /* #ticks with period DHCP_COARSE_TIMER_SECS for rebind time */
00052   ip_addr_t server_ip_addr; /* dhcp server address that offered this lease */
00053   ip_addr_t offered_ip_addr;
00054   ip_addr_t offered_sn_mask;
00055   ip_addr_t offered_gw_addr;
00056  
00057   u32_t offered_t0_lease; /* lease period (in seconds) */
00058   u32_t offered_t1_renew; /* recommended renew time (usually 50% of lease period) */
00059   u32_t offered_t2_rebind; /* recommended rebind time (usually 66% of lease period)  */
00060   /* @todo: LWIP_DHCP_BOOTP_FILE configuration option?
00061      integrate with possible TFTP-client for booting? */
00062 #if LWIP_DHCP_BOOTP_FILE
00063   ip_addr_t offered_si_addr;
00064   char boot_file_name[DHCP_FILE_LEN];
00065 #endif /* LWIP_DHCP_BOOTPFILE */
00066 };
00067 
00068 /* MUST be compiled with "pack structs" or equivalent! */
00069 #ifdef PACK_STRUCT_USE_INCLUDES
00070 #  include "arch/bpstruct.h"
00071 #endif
00072 PACK_STRUCT_BEGIN
00073 /** minimum set of fields of any DHCP message */
00074 struct dhcp_msg
00075 {
00076   PACK_STRUCT_FIELD(u8_t op);
00077   PACK_STRUCT_FIELD(u8_t htype);
00078   PACK_STRUCT_FIELD(u8_t hlen);
00079   PACK_STRUCT_FIELD(u8_t hops);
00080   PACK_STRUCT_FIELD(u32_t xid);
00081   PACK_STRUCT_FIELD(u16_t secs);
00082   PACK_STRUCT_FIELD(u16_t flags);
00083   PACK_STRUCT_FIELD(ip_addr_p_t ciaddr);
00084   PACK_STRUCT_FIELD(ip_addr_p_t yiaddr);
00085   PACK_STRUCT_FIELD(ip_addr_p_t siaddr);
00086   PACK_STRUCT_FIELD(ip_addr_p_t giaddr);
00087   PACK_STRUCT_FIELD(u8_t chaddr[DHCP_CHADDR_LEN]);
00088   PACK_STRUCT_FIELD(u8_t sname[DHCP_SNAME_LEN]);
00089   PACK_STRUCT_FIELD(u8_t file[DHCP_FILE_LEN]);
00090   PACK_STRUCT_FIELD(u32_t cookie);
00091 #define DHCP_MIN_OPTIONS_LEN 68U
00092 /** make sure user does not configure this too small */
00093 #if ((defined(DHCP_OPTIONS_LEN)) && (DHCP_OPTIONS_LEN < DHCP_MIN_OPTIONS_LEN))
00094 #  undef DHCP_OPTIONS_LEN
00095 #endif
00096 /** allow this to be configured in lwipopts.h, but not too small */
00097 #if (!defined(DHCP_OPTIONS_LEN))
00098 /** set this to be sufficient for your options in outgoing DHCP msgs */
00099 #  define DHCP_OPTIONS_LEN DHCP_MIN_OPTIONS_LEN
00100 #endif
00101   PACK_STRUCT_FIELD(u8_t options[DHCP_OPTIONS_LEN]);
00102 } PACK_STRUCT_STRUCT;
00103 PACK_STRUCT_END
00104 #ifdef PACK_STRUCT_USE_INCLUDES
00105 #  include "arch/epstruct.h"
00106 #endif
00107 
00108 void dhcp_set_struct(struct netif *netif, struct dhcp *dhcp);
00109 /** start DHCP configuration */
00110 err_t dhcp_start(struct netif *netif);
00111 /** enforce early lease renewal (not needed normally)*/
00112 err_t dhcp_renew(struct netif *netif);
00113 /** release the DHCP lease, usually called before dhcp_stop()*/
00114 err_t dhcp_release(struct netif *netif);
00115 /** stop DHCP configuration */
00116 void dhcp_stop(struct netif *netif);
00117 /** inform server of our manual IP address */
00118 void dhcp_inform(struct netif *netif);
00119 /** Handle a possible change in the network configuration */
00120 void dhcp_network_changed(struct netif *netif);
00121 
00122 /** if enabled, check whether the offered IP address is not in use, using ARP */
00123 #if DHCP_DOES_ARP_CHECK
00124 void dhcp_arp_reply(struct netif *netif, ip_addr_t *addr);
00125 #endif
00126 
00127 /** to be called every minute */
00128 void dhcp_coarse_tmr(void);
00129 /** to be called every half second */
00130 void dhcp_fine_tmr(void);
00131  
00132 /** DHCP message item offsets and length */
00133 #define DHCP_OP_OFS       0
00134 #define DHCP_HTYPE_OFS    1
00135 #define DHCP_HLEN_OFS     2
00136 #define DHCP_HOPS_OFS     3
00137 #define DHCP_XID_OFS      4
00138 #define DHCP_SECS_OFS     8
00139 #define DHCP_FLAGS_OFS    10
00140 #define DHCP_CIADDR_OFS   12
00141 #define DHCP_YIADDR_OFS   16
00142 #define DHCP_SIADDR_OFS   20
00143 #define DHCP_GIADDR_OFS   24
00144 #define DHCP_CHADDR_OFS   28
00145 #define DHCP_SNAME_OFS    44
00146 #define DHCP_FILE_OFS     108
00147 #define DHCP_MSG_LEN      236
00148 
00149 #define DHCP_COOKIE_OFS   DHCP_MSG_LEN
00150 #define DHCP_OPTIONS_OFS  (DHCP_MSG_LEN + 4)
00151 
00152 #define DHCP_CLIENT_PORT  68  
00153 #define DHCP_SERVER_PORT  67
00154 
00155 /** DHCP client states */
00156 #define DHCP_OFF          0
00157 #define DHCP_REQUESTING   1
00158 #define DHCP_INIT         2
00159 #define DHCP_REBOOTING    3
00160 #define DHCP_REBINDING    4
00161 #define DHCP_RENEWING     5
00162 #define DHCP_SELECTING    6
00163 #define DHCP_INFORMING    7
00164 #define DHCP_CHECKING     8
00165 #define DHCP_PERMANENT    9
00166 #define DHCP_BOUND        10
00167 /** not yet implemented #define DHCP_RELEASING 11 */
00168 #define DHCP_BACKING_OFF  12
00169 
00170 /** AUTOIP cooperatation flags */
00171 #define DHCP_AUTOIP_COOP_STATE_OFF  0
00172 #define DHCP_AUTOIP_COOP_STATE_ON   1
00173  
00174 #define DHCP_BOOTREQUEST  1
00175 #define DHCP_BOOTREPLY    2
00176 
00177 /** DHCP message types */
00178 #define DHCP_DISCOVER 1
00179 #define DHCP_OFFER    2
00180 #define DHCP_REQUEST  3
00181 #define DHCP_DECLINE  4
00182 #define DHCP_ACK      5
00183 #define DHCP_NAK      6
00184 #define DHCP_RELEASE  7
00185 #define DHCP_INFORM   8
00186 
00187 /** DHCP hardware type, currently only ethernet is supported */
00188 #define DHCP_HTYPE_ETH 1
00189 
00190 #define DHCP_MAGIC_COOKIE 0x63825363UL
00191 
00192 /* This is a list of options for BOOTP and DHCP, see RFC 2132 for descriptions */
00193 
00194 /** BootP options */
00195 #define DHCP_OPTION_PAD 0
00196 #define DHCP_OPTION_SUBNET_MASK 1 /* RFC 2132 3.3 */
00197 #define DHCP_OPTION_ROUTER 3
00198 #define DHCP_OPTION_DNS_SERVER 6 
00199 #define DHCP_OPTION_HOSTNAME 12
00200 #define DHCP_OPTION_IP_TTL 23
00201 #define DHCP_OPTION_MTU 26
00202 #define DHCP_OPTION_BROADCAST 28
00203 #define DHCP_OPTION_TCP_TTL 37
00204 #define DHCP_OPTION_END 255
00205 
00206 /** DHCP options */
00207 #define DHCP_OPTION_REQUESTED_IP 50 /* RFC 2132 9.1, requested IP address */
00208 #define DHCP_OPTION_LEASE_TIME 51 /* RFC 2132 9.2, time in seconds, in 4 bytes */
00209 #define DHCP_OPTION_OVERLOAD 52 /* RFC2132 9.3, use file and/or sname field for options */
00210 
00211 #define DHCP_OPTION_MESSAGE_TYPE 53 /* RFC 2132 9.6, important for DHCP */
00212 #define DHCP_OPTION_MESSAGE_TYPE_LEN 1
00213 
00214 #define DHCP_OPTION_SERVER_ID 54 /* RFC 2132 9.7, server IP address */
00215 #define DHCP_OPTION_PARAMETER_REQUEST_LIST 55 /* RFC 2132 9.8, requested option types */
00216 
00217 #define DHCP_OPTION_MAX_MSG_SIZE 57 /* RFC 2132 9.10, message size accepted >= 576 */
00218 #define DHCP_OPTION_MAX_MSG_SIZE_LEN 2
00219 
00220 #define DHCP_OPTION_T1 58 /* T1 renewal time */
00221 #define DHCP_OPTION_T2 59 /* T2 rebinding time */
00222 #define DHCP_OPTION_US 60
00223 #define DHCP_OPTION_CLIENT_ID 61
00224 #define DHCP_OPTION_TFTP_SERVERNAME 66
00225 #define DHCP_OPTION_BOOTFILE 67
00226 
00227 /** possible combinations of overloading the file and sname fields with options */
00228 #define DHCP_OVERLOAD_NONE 0
00229 #define DHCP_OVERLOAD_FILE 1
00230 #define DHCP_OVERLOAD_SNAME  2
00231 #define DHCP_OVERLOAD_SNAME_FILE 3
00232 
00233 #ifdef __cplusplus
00234 }
00235 #endif
00236 
00237 #endif /* LWIP_DHCP */
00238 
00239 #endif /*__LWIP_DHCP_H__*/