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1 /** @file
2  */
3 
4 #ifndef __LWIP_DHCP_H__
5 #define __LWIP_DHCP_H__
6 
7 #include "lwip/opt.h"
8 
9 #if LWIP_DHCP /* don't build if not configured for use in lwipopts.h */
10 
11 #include "lwip/netif.h"
12 #include "lwip/udp.h"
13 
14 #ifdef __cplusplus
15 extern "C" {
16 #endif
17 
18 /** period (in seconds) of the application calling dhcp_coarse_tmr() */
19 #define DHCP_COARSE_TIMER_SECS 60
20 /** period (in milliseconds) of the application calling dhcp_coarse_tmr() */
21 #define DHCP_COARSE_TIMER_MSECS (DHCP_COARSE_TIMER_SECS * 1000UL)
22 /** period (in milliseconds) of the application calling dhcp_fine_tmr() */
23 #define DHCP_FINE_TIMER_MSECS 500
24 
25 #define DHCP_CHADDR_LEN 16U
26 #define DHCP_SNAME_LEN  64U
27 #define DHCP_FILE_LEN   128U
28 
29 struct dhcp
30 {
31   /** transaction identifier of last sent request */
32   u32_t xid;
33   /** our connection to the DHCP server */
34   struct udp_pcb *pcb;
35   /** incoming msg */
36   struct dhcp_msg *msg_in;
37   /** current DHCP state machine state */
38   u8_t state;
39   /** retries of current request */
40   u8_t tries;
41 #if LWIP_DHCP_AUTOIP_COOP
42   u8_t autoip_coop_state;
43 #endif
44   u8_t subnet_mask_given;
45 
46   struct pbuf *p_out; /* pbuf of outcoming msg */
47   struct dhcp_msg *msg_out; /* outgoing msg */
48   u16_t options_out_len; /* outgoing msg options length */
49   u16_t request_timeout; /* #ticks with period DHCP_FINE_TIMER_SECS for request timeout */
50   u16_t t1_timeout;  /* #ticks with period DHCP_COARSE_TIMER_SECS for renewal time */
51   u16_t t2_timeout;  /* #ticks with period DHCP_COARSE_TIMER_SECS for rebind time */
52   ip_addr_t server_ip_addr; /* dhcp server address that offered this lease */
53   ip_addr_t offered_ip_addr;
54   ip_addr_t offered_sn_mask;
55   ip_addr_t offered_gw_addr;
56 
57   u32_t offered_t0_lease; /* lease period (in seconds) */
58   u32_t offered_t1_renew; /* recommended renew time (usually 50% of lease period) */
59   u32_t offered_t2_rebind; /* recommended rebind time (usually 66% of lease period)  */
60   /* @todo: LWIP_DHCP_BOOTP_FILE configuration option?
61      integrate with possible TFTP-client for booting? */
62 #if LWIP_DHCP_BOOTP_FILE
63   ip_addr_t offered_si_addr;
64   char boot_file_name[DHCP_FILE_LEN];
65 #endif /* LWIP_DHCP_BOOTPFILE */
66 };
67 
68 /* MUST be compiled with "pack structs" or equivalent! */
69 #ifdef PACK_STRUCT_USE_INCLUDES
70 #  include "arch/bpstruct.h"
71 #endif
72 PACK_STRUCT_BEGIN
73 /** minimum set of fields of any DHCP message */
74 struct dhcp_msg
75 {
76   PACK_STRUCT_FIELD(u8_t op);
77   PACK_STRUCT_FIELD(u8_t htype);
78   PACK_STRUCT_FIELD(u8_t hlen);
79   PACK_STRUCT_FIELD(u8_t hops);
80   PACK_STRUCT_FIELD(u32_t xid);
81   PACK_STRUCT_FIELD(u16_t secs);
82   PACK_STRUCT_FIELD(u16_t flags);
83   PACK_STRUCT_FIELD(ip_addr_p_t ciaddr);
84   PACK_STRUCT_FIELD(ip_addr_p_t yiaddr);
85   PACK_STRUCT_FIELD(ip_addr_p_t siaddr);
86   PACK_STRUCT_FIELD(ip_addr_p_t giaddr);
87   PACK_STRUCT_FIELD(u8_t chaddr[DHCP_CHADDR_LEN]);
88   PACK_STRUCT_FIELD(u8_t sname[DHCP_SNAME_LEN]);
89   PACK_STRUCT_FIELD(u8_t file[DHCP_FILE_LEN]);
90   PACK_STRUCT_FIELD(u32_t cookie);
91 #define DHCP_MIN_OPTIONS_LEN 68U
92 /** make sure user does not configure this too small */
93 #if ((defined(DHCP_OPTIONS_LEN)) && (DHCP_OPTIONS_LEN < DHCP_MIN_OPTIONS_LEN))
94 #  undef DHCP_OPTIONS_LEN
95 #endif
96 /** allow this to be configured in lwipopts.h, but not too small */
97 #if (!defined(DHCP_OPTIONS_LEN))
98 /** set this to be sufficient for your options in outgoing DHCP msgs */
99 #  define DHCP_OPTIONS_LEN DHCP_MIN_OPTIONS_LEN
100 #endif
101   PACK_STRUCT_FIELD(u8_t options[DHCP_OPTIONS_LEN]);
102 } PACK_STRUCT_STRUCT;
103 PACK_STRUCT_END
104 #ifdef PACK_STRUCT_USE_INCLUDES
105 #  include "arch/epstruct.h"
106 #endif
107 
108 void dhcp_set_struct(struct netif *netif, struct dhcp *dhcp);
109 /** Remove a struct dhcp previously set to the netif using dhcp_set_struct() */
110 #define dhcp_remove_struct(netif) do { (netif)->dhcp = NULL; } while(0)
111 void dhcp_cleanup(struct netif *netif);
112 /** start DHCP configuration */
113 err_t dhcp_start(struct netif *netif);
114 /** enforce early lease renewal (not needed normally)*/
115 err_t dhcp_renew(struct netif *netif);
116 /** release the DHCP lease, usually called before dhcp_stop()*/
117 err_t dhcp_release(struct netif *netif);
118 /** stop DHCP configuration */
119 void dhcp_stop(struct netif *netif);
120 /** inform server of our manual IP address */
121 void dhcp_inform(struct netif *netif);
122 /** Handle a possible change in the network configuration */
123 void dhcp_network_changed(struct netif *netif);
124 
125 /** if enabled, check whether the offered IP address is not in use, using ARP */
126 #if DHCP_DOES_ARP_CHECK
127 void dhcp_arp_reply(struct netif *netif, ip_addr_t *addr);
128 #endif
129 
130 /** to be called every minute */
131 void dhcp_coarse_tmr(void);
132 /** to be called every half second */
133 void dhcp_fine_tmr(void);
134 
135 /** DHCP message item offsets and length */
136 #define DHCP_OP_OFS       0
137 #define DHCP_HTYPE_OFS    1
138 #define DHCP_HLEN_OFS     2
139 #define DHCP_HOPS_OFS     3
140 #define DHCP_XID_OFS      4
141 #define DHCP_SECS_OFS     8
142 #define DHCP_FLAGS_OFS    10
143 #define DHCP_CIADDR_OFS   12
144 #define DHCP_YIADDR_OFS   16
145 #define DHCP_SIADDR_OFS   20
146 #define DHCP_GIADDR_OFS   24
147 #define DHCP_CHADDR_OFS   28
148 #define DHCP_SNAME_OFS    44
149 #define DHCP_FILE_OFS     108
150 #define DHCP_MSG_LEN      236
151 
152 #define DHCP_COOKIE_OFS   DHCP_MSG_LEN
153 #define DHCP_OPTIONS_OFS  (DHCP_MSG_LEN + 4)
154 
155 #define DHCP_CLIENT_PORT  68
156 #define DHCP_SERVER_PORT  67
157 
158 /** DHCP client states */
159 #define DHCP_OFF          0
160 #define DHCP_REQUESTING   1
161 #define DHCP_INIT         2
162 #define DHCP_REBOOTING    3
163 #define DHCP_REBINDING    4
164 #define DHCP_RENEWING     5
165 #define DHCP_SELECTING    6
166 #define DHCP_INFORMING    7
167 #define DHCP_CHECKING     8
168 #define DHCP_PERMANENT    9
169 #define DHCP_BOUND        10
170 /** not yet implemented #define DHCP_RELEASING 11 */
171 #define DHCP_BACKING_OFF  12
172 
173 /** AUTOIP cooperatation flags */
174 #define DHCP_AUTOIP_COOP_STATE_OFF  0
175 #define DHCP_AUTOIP_COOP_STATE_ON   1
176 
177 #define DHCP_BOOTREQUEST  1
178 #define DHCP_BOOTREPLY    2
179 
180 /** DHCP message types */
181 #define DHCP_DISCOVER 1
182 #define DHCP_OFFER    2
183 #define DHCP_REQUEST  3
184 #define DHCP_DECLINE  4
185 #define DHCP_ACK      5
186 #define DHCP_NAK      6
187 #define DHCP_RELEASE  7
188 #define DHCP_INFORM   8
189 
190 /** DHCP hardware type, currently only ethernet is supported */
191 #define DHCP_HTYPE_ETH 1
192 
193 #define DHCP_MAGIC_COOKIE 0x63825363UL
194 
195 /* This is a list of options for BOOTP and DHCP, see RFC 2132 for descriptions */
196 
197 /** BootP options */
198 #define DHCP_OPTION_PAD 0
199 #define DHCP_OPTION_SUBNET_MASK 1 /* RFC 2132 3.3 */
200 #define DHCP_OPTION_ROUTER 3
201 #define DHCP_OPTION_DNS_SERVER 6
202 #define DHCP_OPTION_HOSTNAME 12
203 #define DHCP_OPTION_IP_TTL 23
204 #define DHCP_OPTION_MTU 26
205 #define DHCP_OPTION_BROADCAST 28
206 #define DHCP_OPTION_TCP_TTL 37
207 #define DHCP_OPTION_END 255
208 
209 /** DHCP options */
210 #define DHCP_OPTION_REQUESTED_IP 50 /* RFC 2132 9.1, requested IP address */
211 #define DHCP_OPTION_LEASE_TIME 51 /* RFC 2132 9.2, time in seconds, in 4 bytes */
212 #define DHCP_OPTION_OVERLOAD 52 /* RFC2132 9.3, use file and/or sname field for options */
213 
214 #define DHCP_OPTION_MESSAGE_TYPE 53 /* RFC 2132 9.6, important for DHCP */
215 #define DHCP_OPTION_MESSAGE_TYPE_LEN 1
216 
217 #define DHCP_OPTION_SERVER_ID 54 /* RFC 2132 9.7, server IP address */
218 #define DHCP_OPTION_PARAMETER_REQUEST_LIST 55 /* RFC 2132 9.8, requested option types */
219 
220 #define DHCP_OPTION_MAX_MSG_SIZE 57 /* RFC 2132 9.10, message size accepted >= 576 */
221 #define DHCP_OPTION_MAX_MSG_SIZE_LEN 2
222 
223 #define DHCP_OPTION_T1 58 /* T1 renewal time */
224 #define DHCP_OPTION_T2 59 /* T2 rebinding time */
225 #define DHCP_OPTION_US 60
226 #define DHCP_OPTION_CLIENT_ID 61
227 #define DHCP_OPTION_TFTP_SERVERNAME 66
228 #define DHCP_OPTION_BOOTFILE 67
229 
230 /** possible combinations of overloading the file and sname fields with options */
231 #define DHCP_OVERLOAD_NONE 0
232 #define DHCP_OVERLOAD_FILE 1
233 #define DHCP_OVERLOAD_SNAME  2
234 #define DHCP_OVERLOAD_SNAME_FILE 3
235 
236 #ifdef __cplusplus
237 }
238 #endif
239 
240 #endif /* LWIP_DHCP */
241 
242 #endif /*__LWIP_DHCP_H__*/
243