common.h 14 KB

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  1. /* vi: set sw=4 ts=4: */
  2. /*
  3. * Russ Dill <Russ.Dill@asu.edu> September 2001
  4. * Rewritten by Vladimir Oleynik <dzo@simtreas.ru> (C) 2003
  5. *
  6. * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  7. */
  8. #ifndef UDHCP_COMMON_H
  9. #define UDHCP_COMMON_H 1
  10. #include "libbb.h"
  11. #include <netinet/udp.h>
  12. #include <netinet/ip.h>
  13. PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
  14. extern const uint8_t MAC_BCAST_ADDR[6] ALIGN2; /* six all-ones */
  15. /*** DHCP packet ***/
  16. /* DHCP protocol. See RFC 2131 */
  17. #define DHCP_MAGIC 0x63825363
  18. #define DHCP_OPTIONS_BUFSIZE 308
  19. #define BOOTREQUEST 1
  20. #define BOOTREPLY 2
  21. //TODO: rename ciaddr/yiaddr/chaddr
  22. struct dhcp_packet {
  23. uint8_t op; /* BOOTREQUEST or BOOTREPLY */
  24. uint8_t htype; /* hardware address type. 1 = 10mb ethernet */
  25. uint8_t hlen; /* hardware address length */
  26. uint8_t hops; /* used by relay agents only */
  27. uint32_t xid; /* unique id */
  28. uint16_t secs; /* elapsed since client began acquisition/renewal */
  29. uint16_t flags; /* only one flag so far: */
  30. #define BROADCAST_FLAG 0x8000 /* "I need broadcast replies" */
  31. uint32_t ciaddr; /* client IP (if client is in BOUND, RENEW or REBINDING state) */
  32. uint32_t yiaddr; /* 'your' (client) IP address */
  33. /* IP address of next server to use in bootstrap, returned in DHCPOFFER, DHCPACK by server */
  34. uint32_t siaddr_nip;
  35. uint32_t gateway_nip; /* relay agent IP address */
  36. uint8_t chaddr[16]; /* link-layer client hardware address (MAC) */
  37. uint8_t sname[64]; /* server host name (ASCIZ) */
  38. uint8_t file[128]; /* boot file name (ASCIZ) */
  39. uint32_t cookie; /* fixed first four option bytes (99,130,83,99 dec) */
  40. uint8_t options[DHCP_OPTIONS_BUFSIZE + CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS];
  41. } PACKED;
  42. #define DHCP_PKT_SNAME_LEN 64
  43. #define DHCP_PKT_FILE_LEN 128
  44. #define DHCP_PKT_SNAME_LEN_STR "64"
  45. #define DHCP_PKT_FILE_LEN_STR "128"
  46. struct ip_udp_dhcp_packet {
  47. struct iphdr ip;
  48. struct udphdr udp;
  49. struct dhcp_packet data;
  50. } PACKED;
  51. struct udp_dhcp_packet {
  52. struct udphdr udp;
  53. struct dhcp_packet data;
  54. } PACKED;
  55. enum {
  56. IP_UDP_DHCP_SIZE = sizeof(struct ip_udp_dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS,
  57. UDP_DHCP_SIZE = sizeof(struct udp_dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS,
  58. DHCP_SIZE = sizeof(struct dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS,
  59. };
  60. /* Let's see whether compiler understood us right */
  61. struct BUG_bad_sizeof_struct_ip_udp_dhcp_packet {
  62. char c[IP_UDP_DHCP_SIZE == 576 ? 1 : -1];
  63. };
  64. /*** Options ***/
  65. enum {
  66. OPTION_IP = 1,
  67. OPTION_IP_PAIR,
  68. OPTION_STRING,
  69. /* Opts of STRING_HOST type will be sanitized before they are passed
  70. * to udhcpc script's environment: */
  71. OPTION_STRING_HOST,
  72. // OPTION_BOOLEAN,
  73. OPTION_U8,
  74. OPTION_U16,
  75. // OPTION_S16,
  76. OPTION_U32,
  77. OPTION_S32,
  78. OPTION_BIN,
  79. OPTION_STATIC_ROUTES,
  80. OPTION_6RD,
  81. #if ENABLE_FEATURE_UDHCP_RFC3397
  82. OPTION_DNS_STRING, /* RFC1035 compressed domain name list */
  83. OPTION_SIP_SERVERS,
  84. #endif
  85. OPTION_TYPE_MASK = 0x0f,
  86. /* Client requests this option by default */
  87. OPTION_REQ = 0x10,
  88. /* There can be a list of 1 or more of these */
  89. OPTION_LIST = 0x20,
  90. };
  91. /* DHCP option codes (partial list). See RFC 2132 and
  92. * http://www.iana.org/assignments/bootp-dhcp-parameters/
  93. * Commented out options are handled by common option machinery,
  94. * uncommented ones have special cases (grep for them to see).
  95. */
  96. #define DHCP_PADDING 0x00
  97. #define DHCP_SUBNET 0x01
  98. //#define DHCP_TIME_OFFSET 0x02 /* (localtime - UTC_time) in seconds. signed */
  99. //#define DHCP_ROUTER 0x03
  100. //#define DHCP_TIME_SERVER 0x04 /* RFC 868 time server (32-bit, 0 = 1.1.1900) */
  101. //#define DHCP_NAME_SERVER 0x05 /* IEN 116 _really_ ancient kind of NS */
  102. //#define DHCP_DNS_SERVER 0x06
  103. //#define DHCP_LOG_SERVER 0x07 /* port 704 UDP log (not syslog)
  104. //#define DHCP_COOKIE_SERVER 0x08 /* "quote of the day" server */
  105. //#define DHCP_LPR_SERVER 0x09
  106. #define DHCP_HOST_NAME 0x0c /* either client informs server or server gives name to client */
  107. //#define DHCP_BOOT_SIZE 0x0d
  108. //#define DHCP_DOMAIN_NAME 0x0f /* server gives domain suffix */
  109. //#define DHCP_SWAP_SERVER 0x10
  110. //#define DHCP_ROOT_PATH 0x11
  111. //#define DHCP_IP_TTL 0x17
  112. //#define DHCP_MTU 0x1a
  113. //#define DHCP_BROADCAST 0x1c
  114. //#define DHCP_ROUTES 0x21
  115. //#define DHCP_NIS_DOMAIN 0x28
  116. //#define DHCP_NIS_SERVER 0x29
  117. //#define DHCP_NTP_SERVER 0x2a
  118. //#define DHCP_WINS_SERVER 0x2c
  119. #define DHCP_REQUESTED_IP 0x32 /* sent by client if specific IP is wanted */
  120. #define DHCP_LEASE_TIME 0x33
  121. #define DHCP_OPTION_OVERLOAD 0x34
  122. #define DHCP_MESSAGE_TYPE 0x35
  123. #define DHCP_SERVER_ID 0x36 /* by default server's IP */
  124. #define DHCP_PARAM_REQ 0x37 /* list of options client wants */
  125. //#define DHCP_ERR_MESSAGE 0x38 /* error message when sending NAK etc */
  126. #define DHCP_MAX_SIZE 0x39
  127. #define DHCP_VENDOR 0x3c /* client's vendor (a string) */
  128. #define DHCP_CLIENT_ID 0x3d /* by default client's MAC addr, but may be arbitrarily long */
  129. //#define DHCP_TFTP_SERVER_NAME 0x42 /* same as 'sname' field */
  130. //#define DHCP_BOOT_FILE 0x43 /* same as 'file' field */
  131. //#define DHCP_USER_CLASS 0x4d /* RFC 3004. set of LASCII strings. "I am a printer" etc */
  132. #define DHCP_FQDN 0x51 /* client asks to update DNS to map its FQDN to its new IP */
  133. //#define DHCP_DOMAIN_SEARCH 0x77 /* RFC 3397. set of ASCIZ string, DNS-style compressed */
  134. //#define DHCP_SIP_SERVERS 0x78 /* RFC 3361. flag byte, then: 0: domain names, 1: IP addrs */
  135. //#define DHCP_STATIC_ROUTES 0x79 /* RFC 3442. (mask,ip,router) tuples */
  136. //#define DHCP_VLAN_ID 0x84 /* 802.1P VLAN ID */
  137. //#define DHCP_VLAN_PRIORITY 0x85 /* 802.1Q VLAN priority */
  138. //#define DHCP_PXE_CONF_FILE 0xd1 /* RFC 5071 Configuration File */
  139. //#define DHCP_PXE_PATH_PREFIX 0xd2 /* RFC 5071 Configuration File */
  140. //#define DHCP_MS_STATIC_ROUTES 0xf9 /* Microsoft's pre-RFC 3442 code for 0x79? */
  141. //#define DHCP_WPAD 0xfc /* MSIE's Web Proxy Autodiscovery Protocol */
  142. #define DHCP_END 0xff
  143. /* Offsets in option byte sequence */
  144. #define OPT_CODE 0
  145. #define OPT_LEN 1
  146. #define OPT_DATA 2
  147. /* Bits in "overload" option */
  148. #define OPTION_FIELD 0
  149. #define FILE_FIELD 1
  150. #define SNAME_FIELD 2
  151. /* DHCP_MESSAGE_TYPE values */
  152. #define DHCPDISCOVER 1 /* client -> server */
  153. #define DHCPOFFER 2 /* client <- server */
  154. #define DHCPREQUEST 3 /* client -> server */
  155. #define DHCPDECLINE 4 /* client -> server */
  156. #define DHCPACK 5 /* client <- server */
  157. #define DHCPNAK 6 /* client <- server */
  158. #define DHCPRELEASE 7 /* client -> server */
  159. #define DHCPINFORM 8 /* client -> server */
  160. #define DHCP_MINTYPE DHCPDISCOVER
  161. #define DHCP_MAXTYPE DHCPINFORM
  162. struct dhcp_optflag {
  163. uint8_t flags;
  164. uint8_t code;
  165. };
  166. struct option_set {
  167. uint8_t *data;
  168. struct option_set *next;
  169. };
  170. extern const struct dhcp_optflag dhcp_optflags[];
  171. extern const char dhcp_option_strings[] ALIGN1;
  172. extern const uint8_t dhcp_option_lengths[] ALIGN1;
  173. unsigned FAST_FUNC udhcp_option_idx(const char *name);
  174. uint8_t *udhcp_get_option(struct dhcp_packet *packet, int code) FAST_FUNC;
  175. int udhcp_end_option(uint8_t *optionptr) FAST_FUNC;
  176. void udhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt) FAST_FUNC;
  177. void udhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code, uint32_t data) FAST_FUNC;
  178. #if ENABLE_FEATURE_UDHCP_RFC3397
  179. char *dname_dec(const uint8_t *cstr, int clen, const char *pre) FAST_FUNC;
  180. uint8_t *dname_enc(const uint8_t *cstr, int clen, const char *src, int *retlen) FAST_FUNC;
  181. #endif
  182. struct option_set *udhcp_find_option(struct option_set *opt_list, uint8_t code) FAST_FUNC;
  183. // RFC 2131 Table 5: Fields and options used by DHCP clients
  184. //
  185. // Fields 'hops', 'yiaddr', 'siaddr', 'giaddr' are always zero
  186. //
  187. // Field DHCPDISCOVER DHCPINFORM DHCPREQUEST DHCPDECLINE DHCPRELEASE
  188. // ----- ------------ ------------ ----------- ----------- -----------
  189. // 'xid' selected by client selected by client 'xid' from server selected by client selected by client
  190. // DHCPOFFER message
  191. // 'secs' 0 or seconds since 0 or seconds since 0 or seconds since 0 0
  192. // DHCP process started DHCP process started DHCP process started
  193. // 'flags' Set 'BROADCAST' Set 'BROADCAST' Set 'BROADCAST' 0 0
  194. // flag if client flag if client flag if client
  195. // requires broadcast requires broadcast requires broadcast
  196. // reply reply reply
  197. // 'ciaddr' 0 client's IP 0 or client's IP 0 client's IP
  198. // (BOUND/RENEW/REBIND)
  199. // 'chaddr' client's MAC client's MAC client's MAC client's MAC client's MAC
  200. // 'sname' options or sname options or sname options or sname (unused) (unused)
  201. // 'file' options or file options or file options or file (unused) (unused)
  202. // 'options' options options options message type opt message type opt
  203. //
  204. // Option DHCPDISCOVER DHCPINFORM DHCPREQUEST DHCPDECLINE DHCPRELEASE
  205. // ------ ------------ ---------- ----------- ----------- -----------
  206. // Requested IP address MAY MUST NOT MUST (in MUST MUST NOT
  207. // SELECTING or
  208. // INIT-REBOOT)
  209. // MUST NOT (in
  210. // BOUND or
  211. // RENEWING)
  212. // IP address lease time MAY MUST NOT MAY MUST NOT MUST NOT
  213. // Use 'file'/'sname' fields MAY MAY MAY MAY MAY
  214. // Client identifier MAY MAY MAY MAY MAY
  215. // Vendor class identifier MAY MAY MAY MUST NOT MUST NOT
  216. // Server identifier MUST NOT MUST NOT MUST (after MUST MUST
  217. // SELECTING)
  218. // MUST NOT (after
  219. // INIT-REBOOT,
  220. // BOUND, RENEWING
  221. // or REBINDING)
  222. // Parameter request list MAY MAY MAY MUST NOT MUST NOT
  223. // Maximum message size MAY MAY MAY MUST NOT MUST NOT
  224. // Message SHOULD NOT SHOULD NOT SHOULD NOT SHOULD SHOULD
  225. // Site-specific MAY MAY MAY MUST NOT MUST NOT
  226. // All others MAY MAY MAY MUST NOT MUST NOT
  227. /*** Logging ***/
  228. #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
  229. # define IF_UDHCP_VERBOSE(...) __VA_ARGS__
  230. extern unsigned dhcp_verbose;
  231. # define log1(...) do { if (dhcp_verbose >= 1) bb_info_msg(__VA_ARGS__); } while (0)
  232. # if CONFIG_UDHCP_DEBUG >= 2
  233. void udhcp_dump_packet(struct dhcp_packet *packet) FAST_FUNC;
  234. # define log2(...) do { if (dhcp_verbose >= 2) bb_info_msg(__VA_ARGS__); } while (0)
  235. # else
  236. # define udhcp_dump_packet(...) ((void)0)
  237. # define log2(...) ((void)0)
  238. # endif
  239. # if CONFIG_UDHCP_DEBUG >= 3
  240. # define log3(...) do { if (dhcp_verbose >= 3) bb_info_msg(__VA_ARGS__); } while (0)
  241. # else
  242. # define log3(...) ((void)0)
  243. # endif
  244. #else
  245. # define IF_UDHCP_VERBOSE(...)
  246. # define udhcp_dump_packet(...) ((void)0)
  247. # define log1(...) ((void)0)
  248. # define log2(...) ((void)0)
  249. # define log3(...) ((void)0)
  250. #endif
  251. /*** Other shared functions ***/
  252. /* 2nd param is "uint32_t*" */
  253. int FAST_FUNC udhcp_str2nip(const char *str, void *arg);
  254. /* 2nd param is "struct option_set**" */
  255. int FAST_FUNC udhcp_str2optset(const char *str, void *arg);
  256. void udhcp_init_header(struct dhcp_packet *packet, char type) FAST_FUNC;
  257. int udhcp_recv_kernel_packet(struct dhcp_packet *packet, int fd) FAST_FUNC;
  258. int udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,
  259. uint32_t source_nip, int source_port,
  260. uint32_t dest_nip, int dest_port, const uint8_t *dest_arp,
  261. int ifindex) FAST_FUNC;
  262. int udhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt,
  263. uint32_t source_nip, int source_port,
  264. uint32_t dest_nip, int dest_port) FAST_FUNC;
  265. void udhcp_sp_setup(void) FAST_FUNC;
  266. int udhcp_sp_fd_set(fd_set *rfds, int extra_fd) FAST_FUNC;
  267. int udhcp_sp_read(const fd_set *rfds) FAST_FUNC;
  268. int udhcp_read_interface(const char *interface, int *ifindex, uint32_t *nip, uint8_t *mac) FAST_FUNC;
  269. int udhcp_listen_socket(/*uint32_t ip,*/ int port, const char *inf) FAST_FUNC;
  270. /* Returns 1 if no reply received */
  271. int arpping(uint32_t test_nip,
  272. const uint8_t *safe_mac,
  273. uint32_t from_ip,
  274. uint8_t *from_mac,
  275. const char *interface,
  276. unsigned timeo) FAST_FUNC;
  277. /* note: ip is a pointer to an IPv6 in network order, possibly misaliged */
  278. int sprint_nip6(char *dest, /*const char *pre,*/ const uint8_t *ip) FAST_FUNC;
  279. POP_SAVED_FUNCTION_VISIBILITY
  280. #endif