dhcpd.h 4.7 KB

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  1. /* vi: set sw=4 ts=4: */
  2. /*
  3. * Licensed under GPLv2, see file LICENSE in this tarball for details.
  4. */
  5. #ifndef UDHCP_DHCPD_H
  6. #define UDHCP_DHCPD_H 1
  7. PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
  8. /* Defaults you may want to tweak */
  9. /* Default max_lease_sec */
  10. #define DEFAULT_LEASE_TIME (60*60*24 * 10)
  11. #define LEASES_FILE CONFIG_DHCPD_LEASES_FILE
  12. /* Where to find the DHCP server configuration file */
  13. #define DHCPD_CONF_FILE "/etc/udhcpd.conf"
  14. struct static_lease {
  15. struct static_lease *next;
  16. uint32_t nip;
  17. uint8_t mac[6];
  18. };
  19. struct server_config_t {
  20. char *interface; /* interface to use */
  21. //TODO: ifindex, server_nip, server_mac
  22. // are obtained from interface name.
  23. // Instead of querying them *once*, create update_server_network_data_cache()
  24. // and call it before any usage of these fields.
  25. // update_server_network_data_cache() must re-query data
  26. // if more than N seconds have passed after last use.
  27. int ifindex;
  28. uint32_t server_nip;
  29. #if ENABLE_FEATURE_UDHCP_PORT
  30. uint16_t port;
  31. #endif
  32. uint8_t server_mac[6]; /* our MAC address (used only for ARP probing) */
  33. struct option_set *options; /* list of DHCP options loaded from the config file */
  34. /* start,end are in host order: we need to compare start <= ip <= end */
  35. uint32_t start_ip; /* start address of leases, in host order */
  36. uint32_t end_ip; /* end of leases, in host order */
  37. uint32_t max_lease_sec; /* maximum lease time (host order) */
  38. uint32_t min_lease_sec; /* minimum lease time a client can request */
  39. uint32_t max_leases; /* maximum number of leases (including reserved addresses) */
  40. uint32_t auto_time; /* how long should udhcpd wait before writing a config file.
  41. * if this is zero, it will only write one on SIGUSR1 */
  42. uint32_t decline_time; /* how long an address is reserved if a client returns a
  43. * decline message */
  44. uint32_t conflict_time; /* how long an arp conflict offender is leased for */
  45. uint32_t offer_time; /* how long an offered address is reserved */
  46. uint32_t siaddr_nip; /* "next server" bootp option */
  47. char *lease_file;
  48. char *pidfile;
  49. char *notify_file; /* what to run whenever leases are written */
  50. char *sname; /* bootp server name */
  51. char *boot_file; /* bootp boot file option */
  52. struct static_lease *static_leases; /* List of ip/mac pairs to assign static leases */
  53. } FIX_ALIASING;
  54. #define server_config (*(struct server_config_t*)&bb_common_bufsiz1)
  55. /* client_config sits in 2nd half of bb_common_bufsiz1 */
  56. #if ENABLE_FEATURE_UDHCP_PORT
  57. #define SERVER_PORT (server_config.port)
  58. #else
  59. #define SERVER_PORT 67
  60. #endif
  61. typedef uint32_t leasetime_t;
  62. typedef int32_t signed_leasetime_t;
  63. struct dyn_lease {
  64. /* Unix time when lease expires. Kept in memory in host order.
  65. * When written to file, converted to network order
  66. * and adjusted (current time subtracted) */
  67. leasetime_t expires;
  68. /* "nip": IP in network order */
  69. uint32_t lease_nip;
  70. /* We use lease_mac[6], since e.g. ARP probing uses
  71. * only 6 first bytes anyway. We check received dhcp packets
  72. * that their hlen == 6 and thus chaddr has only 6 significant bytes
  73. * (dhcp packet has chaddr[16], not [6])
  74. */
  75. uint8_t lease_mac[6];
  76. char hostname[20];
  77. uint8_t pad[2];
  78. /* total size is a multiply of 4 */
  79. } PACKED;
  80. extern struct dyn_lease *g_leases;
  81. struct dyn_lease *add_lease(
  82. const uint8_t *chaddr, uint32_t yiaddr,
  83. leasetime_t leasetime,
  84. const char *hostname, int hostname_len
  85. ) FAST_FUNC;
  86. int is_expired_lease(struct dyn_lease *lease) FAST_FUNC;
  87. struct dyn_lease *find_lease_by_mac(const uint8_t *mac) FAST_FUNC;
  88. struct dyn_lease *find_lease_by_nip(uint32_t nip) FAST_FUNC;
  89. uint32_t find_free_or_expired_nip(const uint8_t *safe_mac) FAST_FUNC;
  90. /* Config file parser will pass static lease info to this function
  91. * which will add it to a data structure that can be searched later */
  92. void add_static_lease(struct static_lease **st_lease_pp, uint8_t *mac, uint32_t nip) FAST_FUNC;
  93. /* Find static lease IP by mac */
  94. uint32_t get_static_nip_by_mac(struct static_lease *st_lease, void *arg) FAST_FUNC;
  95. /* Check to see if an IP is reserved as a static IP */
  96. int is_nip_reserved(struct static_lease *st_lease, uint32_t nip) FAST_FUNC;
  97. /* Print out static leases just to check what's going on (debug code) */
  98. #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
  99. void log_static_leases(struct static_lease **st_lease_pp) FAST_FUNC;
  100. #else
  101. # define log_static_leases(st_lease_pp) ((void)0)
  102. #endif
  103. void read_config(const char *file) FAST_FUNC;
  104. void write_leases(void) FAST_FUNC;
  105. void read_leases(const char *file) FAST_FUNC;
  106. POP_SAVED_FUNCTION_VISIBILITY
  107. #endif