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 struct dhcp
00026 {
00027   /** transaction identifier of last sent request */ 
00028   u32_t xid;
00029   /** our connection to the DHCP server */ 
00030   struct udp_pcb *pcb;
00031   /** incoming msg */
00032   struct dhcp_msg *msg_in;
00033   /** incoming msg options */
00034   void *options_in; 
00035   /** ingoing msg options length */
00036   u16_t options_in_len;
00037   /** current DHCP state machine state */
00038   u8_t state;
00039   /** retries of current request */
00040   u8_t tries;
00041 
00042   struct pbuf *p_out; /* pbuf of outcoming msg */
00043   struct dhcp_msg *msg_out; /* outgoing msg */
00044   u16_t options_out_len; /* outgoing msg options length */
00045   u16_t request_timeout; /* #ticks with period DHCP_FINE_TIMER_SECS for request timeout */
00046   u16_t t1_timeout;  /* #ticks with period DHCP_COARSE_TIMER_SECS for renewal time */
00047   u16_t t2_timeout;  /* #ticks with period DHCP_COARSE_TIMER_SECS for rebind time */
00048   struct ip_addr server_ip_addr; /* dhcp server address that offered this lease */
00049   struct ip_addr offered_ip_addr;
00050   struct ip_addr offered_sn_mask;
00051   struct ip_addr offered_gw_addr;
00052   struct ip_addr offered_bc_addr;
00053 #define DHCP_MAX_DNS 2
00054   u32_t dns_count; /* actual number of DNS servers obtained */
00055   struct ip_addr offered_dns_addr[DHCP_MAX_DNS]; /* DNS server addresses */
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 #if LWIP_DHCP_AUTOIP_COOP
00061   u8_t autoip_coop_state;
00062 #endif
00063 /** Patch #1308
00064  *  TODO: See dhcp.c "TODO"s
00065  */
00066 #if 0
00067   struct ip_addr offered_si_addr;
00068   u8_t *boot_file_name;
00069 #endif
00070 };
00071 
00072 /* MUST be compiled with "pack structs" or equivalent! */
00073 #ifdef PACK_STRUCT_USE_INCLUDES
00074 #  include "arch/bpstruct.h"
00075 #endif
00076 PACK_STRUCT_BEGIN
00077 /** minimum set of fields of any DHCP message */
00078 struct dhcp_msg
00079 {
00080   PACK_STRUCT_FIELD(u8_t op);
00081   PACK_STRUCT_FIELD(u8_t htype);
00082   PACK_STRUCT_FIELD(u8_t hlen);
00083   PACK_STRUCT_FIELD(u8_t hops);
00084   PACK_STRUCT_FIELD(u32_t xid);
00085   PACK_STRUCT_FIELD(u16_t secs);
00086   PACK_STRUCT_FIELD(u16_t flags);
00087   PACK_STRUCT_FIELD(struct ip_addr ciaddr);
00088   PACK_STRUCT_FIELD(struct ip_addr yiaddr);
00089   PACK_STRUCT_FIELD(struct ip_addr siaddr);
00090   PACK_STRUCT_FIELD(struct ip_addr giaddr);
00091 #define DHCP_CHADDR_LEN 16U
00092   PACK_STRUCT_FIELD(u8_t chaddr[DHCP_CHADDR_LEN]);
00093 #define DHCP_SNAME_LEN 64U
00094   PACK_STRUCT_FIELD(u8_t sname[DHCP_SNAME_LEN]);
00095 #define DHCP_FILE_LEN 128U
00096   PACK_STRUCT_FIELD(u8_t file[DHCP_FILE_LEN]);
00097   PACK_STRUCT_FIELD(u32_t cookie);
00098 #define DHCP_MIN_OPTIONS_LEN 68U
00099 /** make sure user does not configure this too small */
00100 #if ((defined(DHCP_OPTIONS_LEN)) && (DHCP_OPTIONS_LEN < DHCP_MIN_OPTIONS_LEN))
00101 #  undef DHCP_OPTIONS_LEN
00102 #endif
00103 /** allow this to be configured in lwipopts.h, but not too small */
00104 #if (!defined(DHCP_OPTIONS_LEN))
00105 /** set this to be sufficient for your options in outgoing DHCP msgs */
00106 #  define DHCP_OPTIONS_LEN DHCP_MIN_OPTIONS_LEN
00107 #endif
00108   PACK_STRUCT_FIELD(u8_t options[DHCP_OPTIONS_LEN]);
00109 } PACK_STRUCT_STRUCT;
00110 PACK_STRUCT_END
00111 #ifdef PACK_STRUCT_USE_INCLUDES
00112 #  include "arch/epstruct.h"
00113 #endif
00114 
00115 /** start DHCP configuration */
00116 err_t dhcp_start(struct netif *netif);
00117 /** enforce early lease renewal (not needed normally)*/
00118 err_t dhcp_renew(struct netif *netif);
00119 /** release the DHCP lease, usually called before dhcp_stop()*/
00120 err_t dhcp_release(struct netif *netif);
00121 /** stop DHCP configuration */
00122 void dhcp_stop(struct netif *netif);
00123 /** inform server of our manual IP address */
00124 void dhcp_inform(struct netif *netif);
00125 /** Handle a possible change in the network configuration */
00126 void dhcp_network_changed(struct netif *netif);
00127 
00128 /** if enabled, check whether the offered IP address is not in use, using ARP */
00129 #if DHCP_DOES_ARP_CHECK
00130 void dhcp_arp_reply(struct netif *netif, struct ip_addr *addr);
00131 #endif
00132 
00133 /** to be called every minute */
00134 void dhcp_coarse_tmr(void);
00135 /** to be called every half second */
00136 void dhcp_fine_tmr(void);
00137  
00138 /** DHCP message item offsets and length */
00139 #define DHCP_MSG_OFS (UDP_DATA_OFS)  
00140   #define DHCP_OP_OFS (DHCP_MSG_OFS + 0)
00141   #define DHCP_HTYPE_OFS (DHCP_MSG_OFS + 1)
00142   #define DHCP_HLEN_OFS (DHCP_MSG_OFS + 2)
00143   #define DHCP_HOPS_OFS (DHCP_MSG_OFS + 3)
00144   #define DHCP_XID_OFS (DHCP_MSG_OFS + 4)
00145   #define DHCP_SECS_OFS (DHCP_MSG_OFS + 8)
00146   #define DHCP_FLAGS_OFS (DHCP_MSG_OFS + 10)
00147   #define DHCP_CIADDR_OFS (DHCP_MSG_OFS + 12)
00148   #define DHCP_YIADDR_OFS (DHCP_MSG_OFS + 16)
00149   #define DHCP_SIADDR_OFS (DHCP_MSG_OFS + 20)
00150   #define DHCP_GIADDR_OFS (DHCP_MSG_OFS + 24)
00151   #define DHCP_CHADDR_OFS (DHCP_MSG_OFS + 28)
00152   #define DHCP_SNAME_OFS (DHCP_MSG_OFS + 44)
00153   #define DHCP_FILE_OFS (DHCP_MSG_OFS + 108)
00154 #define DHCP_MSG_LEN 236
00155 
00156 #define DHCP_COOKIE_OFS (DHCP_MSG_OFS + DHCP_MSG_LEN)
00157 #define DHCP_OPTIONS_OFS (DHCP_MSG_OFS + DHCP_MSG_LEN + 4)
00158 
00159 #define DHCP_CLIENT_PORT 68  
00160 #define DHCP_SERVER_PORT 67
00161 
00162 /** DHCP client states */
00163 #define DHCP_REQUESTING 1
00164 #define DHCP_INIT 2
00165 #define DHCP_REBOOTING 3
00166 #define DHCP_REBINDING 4
00167 #define DHCP_RENEWING 5
00168 #define DHCP_SELECTING 6
00169 #define DHCP_INFORMING 7
00170 #define DHCP_CHECKING 8
00171 #define DHCP_PERMANENT 9
00172 #define DHCP_BOUND 10
00173 /** not yet implemented #define DHCP_RELEASING 11 */
00174 #define DHCP_BACKING_OFF 12
00175 #define DHCP_OFF 13
00176 
00177 /** AUTOIP cooperatation flags */
00178 #define DHCP_AUTOIP_COOP_STATE_OFF 0
00179 #define DHCP_AUTOIP_COOP_STATE_ON 1
00180  
00181 #define DHCP_BOOTREQUEST 1
00182 #define DHCP_BOOTREPLY 2
00183 
00184 #define DHCP_DISCOVER 1
00185 #define DHCP_OFFER 2
00186 #define DHCP_REQUEST 3
00187 #define DHCP_DECLINE 4
00188 #define DHCP_ACK 5
00189 #define DHCP_NAK 6
00190 #define DHCP_RELEASE 7
00191 #define DHCP_INFORM 8
00192 
00193 #define DHCP_HTYPE_ETH 1
00194 
00195 #define DHCP_HLEN_ETH 6
00196 
00197 #define DHCP_BROADCAST_FLAG 15
00198 #define DHCP_BROADCAST_MASK (1 << DHCP_FLAG_BROADCAST)
00199 
00200 /** BootP options */
00201 #define DHCP_OPTION_PAD 0
00202 #define DHCP_OPTION_SUBNET_MASK 1 /* RFC 2132 3.3 */
00203 #define DHCP_OPTION_ROUTER 3
00204 #define DHCP_OPTION_DNS_SERVER 6 
00205 #define DHCP_OPTION_HOSTNAME 12
00206 #define DHCP_OPTION_IP_TTL 23
00207 #define DHCP_OPTION_MTU 26
00208 #define DHCP_OPTION_BROADCAST 28
00209 #define DHCP_OPTION_TCP_TTL 37
00210 #define DHCP_OPTION_END 255
00211 
00212 /** DHCP options */
00213 #define DHCP_OPTION_REQUESTED_IP 50 /* RFC 2132 9.1, requested IP address */
00214 #define DHCP_OPTION_LEASE_TIME 51 /* RFC 2132 9.2, time in seconds, in 4 bytes */
00215 #define DHCP_OPTION_OVERLOAD 52 /* RFC2132 9.3, use file and/or sname field for options */
00216 
00217 #define DHCP_OPTION_MESSAGE_TYPE 53 /* RFC 2132 9.6, important for DHCP */
00218 #define DHCP_OPTION_MESSAGE_TYPE_LEN 1
00219 
00220 
00221 #define DHCP_OPTION_SERVER_ID 54 /* RFC 2132 9.7, server IP address */
00222 #define DHCP_OPTION_PARAMETER_REQUEST_LIST 55 /* RFC 2132 9.8, requested option types */
00223 
00224 #define DHCP_OPTION_MAX_MSG_SIZE 57 /* RFC 2132 9.10, message size accepted >= 576 */
00225 #define DHCP_OPTION_MAX_MSG_SIZE_LEN 2
00226 
00227 #define DHCP_OPTION_T1 58 /* T1 renewal time */
00228 #define DHCP_OPTION_T2 59 /* T2 rebinding time */
00229 #define DHCP_OPTION_US 60
00230 #define DHCP_OPTION_CLIENT_ID 61
00231 #define DHCP_OPTION_TFTP_SERVERNAME 66
00232 #define DHCP_OPTION_BOOTFILE 67
00233 
00234 /** possible combinations of overloading the file and sname fields with options */
00235 #define DHCP_OVERLOAD_NONE 0
00236 #define DHCP_OVERLOAD_FILE 1
00237 #define DHCP_OVERLOAD_SNAME  2
00238 #define DHCP_OVERLOAD_SNAME_FILE 3
00239 
00240 #ifdef __cplusplus
00241 }
00242 #endif
00243 
00244 #endif /* LWIP_DHCP */
00245 
00246 #endif /*__LWIP_DHCP_H__*/