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