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 11#include "libbb.h" 12#include <netinet/udp.h> 13#include <netinet/ip.h> 14 15PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN 16 17extern const uint8_t MAC_BCAST_ADDR[6] ALIGN2; /* six all-ones */ 18 19 20/*** DHCP packet ***/ 21 22/* DHCP protocol. See RFC 2131 */ 23#define DHCP_MAGIC 0x63825363 24#define DHCP_OPTIONS_BUFSIZE 308 25#define BOOTREQUEST 1 26#define BOOTREPLY 2 27 28//TODO: rename ciaddr/yiaddr/chaddr 29struct dhcp_packet { 30 uint8_t op; /* BOOTREQUEST or BOOTREPLY */ 31 uint8_t htype; /* hardware address type. 1 = 10mb ethernet */ 32 uint8_t hlen; /* hardware address length */ 33 uint8_t hops; /* used by relay agents only */ 34 uint32_t xid; /* unique id */ 35 uint16_t secs; /* elapsed since client began acquisition/renewal */ 36 uint16_t flags; /* only one flag so far: */ 37#define BROADCAST_FLAG 0x8000 /* "I need broadcast replies" */ 38 uint32_t ciaddr; /* client IP (if client is in BOUND, RENEW or REBINDING state) */ 39 uint32_t yiaddr; /* 'your' (client) IP address */ 40 /* IP address of next server to use in bootstrap, returned in DHCPOFFER, DHCPACK by server */ 41 uint32_t siaddr_nip; 42 uint32_t gateway_nip; /* relay agent IP address */ 43 uint8_t chaddr[16]; /* link-layer client hardware address (MAC) */ 44 uint8_t sname[64]; /* server host name (ASCIZ) */ 45 uint8_t file[128]; /* boot file name (ASCIZ) */ 46 uint32_t cookie; /* fixed first four option bytes (99,130,83,99 dec) */ 47 uint8_t options[DHCP_OPTIONS_BUFSIZE + CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS]; 48} PACKED; 49#define DHCP_PKT_SNAME_LEN 64 50#define DHCP_PKT_FILE_LEN 128 51#define DHCP_PKT_SNAME_LEN_STR "64" 52#define DHCP_PKT_FILE_LEN_STR "128" 53 54struct ip_udp_dhcp_packet { 55 struct iphdr ip; 56 struct udphdr udp; 57 struct dhcp_packet data; 58} PACKED; 59 60struct udp_dhcp_packet { 61 struct udphdr udp; 62 struct dhcp_packet data; 63} PACKED; 64 65enum { 66 IP_UDP_DHCP_SIZE = sizeof(struct ip_udp_dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS, 67 UDP_DHCP_SIZE = sizeof(struct udp_dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS, 68 DHCP_SIZE = sizeof(struct dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS, 69}; 70 71/* Let's see whether compiler understood us right */ 72struct BUG_bad_sizeof_struct_ip_udp_dhcp_packet { 73 char c[IP_UDP_DHCP_SIZE == 576 ? 1 : -1]; 74}; 75 76 77/*** Options ***/ 78 79enum { 80 OPTION_IP = 1, 81 OPTION_IP_PAIR, 82 OPTION_STRING, 83 /* Opts of STRING_HOST type will be sanitized before they are passed 84 * to udhcpc script's environment: */ 85 OPTION_STRING_HOST, 86// OPTION_BOOLEAN, 87 OPTION_U8, 88 OPTION_U16, 89// OPTION_S16, 90 OPTION_U32, 91 OPTION_S32, 92 OPTION_BIN, 93 OPTION_STATIC_ROUTES, 94#if ENABLE_FEATURE_IPV6 95 OPTION_6RD, 96#endif 97#if ENABLE_FEATURE_UDHCP_RFC3397 98 OPTION_DNS_STRING, /* RFC1035 compressed domain name list */ 99 OPTION_SIP_SERVERS, 100#endif 101 102 OPTION_TYPE_MASK = 0x0f, 103 /* Client requests this option by default */ 104 OPTION_REQ = 0x10, 105 /* There can be a list of 1 or more of these */ 106 OPTION_LIST = 0x20, 107}; 108 109/* DHCP option codes (partial list). See RFC 2132 and 110 * http://www.iana.org/assignments/bootp-dhcp-parameters/ 111 * Commented out options are handled by common option machinery, 112 * uncommented ones have special cases (grep for them to see). 113 */ 114#define DHCP_PADDING 0x00 115#define DHCP_SUBNET 0x01 116//#define DHCP_TIME_OFFSET 0x02 /* (localtime - UTC_time) in seconds. signed */ 117//#define DHCP_ROUTER 0x03 118//#define DHCP_TIME_SERVER 0x04 /* RFC 868 time server (32-bit, 0 = 1.1.1900) */ 119//#define DHCP_NAME_SERVER 0x05 /* IEN 116 _really_ ancient kind of NS */ 120//#define DHCP_DNS_SERVER 0x06 121//#define DHCP_LOG_SERVER 0x07 /* port 704 UDP log (not syslog) 122//#define DHCP_COOKIE_SERVER 0x08 /* "quote of the day" server */ 123//#define DHCP_LPR_SERVER 0x09 124#define DHCP_HOST_NAME 0x0c /* either client informs server or server gives name to client */ 125//#define DHCP_BOOT_SIZE 0x0d 126//#define DHCP_DOMAIN_NAME 0x0f /* server gives domain suffix */ 127//#define DHCP_SWAP_SERVER 0x10 128//#define DHCP_ROOT_PATH 0x11 129//#define DHCP_IP_TTL 0x17 130//#define DHCP_MTU 0x1a 131//#define DHCP_BROADCAST 0x1c 132//#define DHCP_ROUTES 0x21 133//#define DHCP_NIS_DOMAIN 0x28 134//#define DHCP_NIS_SERVER 0x29 135//#define DHCP_NTP_SERVER 0x2a 136//#define DHCP_WINS_SERVER 0x2c 137#define DHCP_REQUESTED_IP 0x32 /* sent by client if specific IP is wanted */ 138#define DHCP_LEASE_TIME 0x33 139#define DHCP_OPTION_OVERLOAD 0x34 140#define DHCP_MESSAGE_TYPE 0x35 141#define DHCP_SERVER_ID 0x36 /* by default server's IP */ 142#define DHCP_PARAM_REQ 0x37 /* list of options client wants */ 143//#define DHCP_ERR_MESSAGE 0x38 /* error message when sending NAK etc */ 144#define DHCP_MAX_SIZE 0x39 145#define DHCP_VENDOR 0x3c /* client's vendor (a string) */ 146#define DHCP_CLIENT_ID 0x3d /* by default client's MAC addr, but may be arbitrarily long */ 147//#define DHCP_TFTP_SERVER_NAME 0x42 /* same as 'sname' field */ 148//#define DHCP_BOOT_FILE 0x43 /* same as 'file' field */ 149//#define DHCP_USER_CLASS 0x4d /* RFC 3004. set of LASCII strings. "I am a printer" etc */ 150#define DHCP_FQDN 0x51 /* client asks to update DNS to map its FQDN to its new IP */ 151//#define DHCP_DOMAIN_SEARCH 0x77 /* RFC 3397. set of ASCIZ string, DNS-style compressed */ 152//#define DHCP_SIP_SERVERS 0x78 /* RFC 3361. flag byte, then: 0: domain names, 1: IP addrs */ 153//#define DHCP_STATIC_ROUTES 0x79 /* RFC 3442. (mask,ip,router) tuples */ 154//#define DHCP_VLAN_ID 0x84 /* 802.1P VLAN ID */ 155//#define DHCP_VLAN_PRIORITY 0x85 /* 802.1Q VLAN priority */ 156//#define DHCP_PXE_CONF_FILE 0xd1 /* RFC 5071 Configuration File */ 157//#define DHCP_PXE_PATH_PREFIX 0xd2 /* RFC 5071 Configuration File */ 158//#define DHCP_6RD 0xd4 /* RFC 5969 6RD option */ 159//#define DHCP_COMCAST_6RD 0x96 /* Comcast ISP RFC 5969 compatible 6RD option */ 160//#define DHCP_MS_STATIC_ROUTES 0xf9 /* Microsoft's pre-RFC 3442 code for 0x79? */ 161//#define DHCP_WPAD 0xfc /* MSIE's Web Proxy Autodiscovery Protocol */ 162#define DHCP_END 0xff 163 164/* Offsets in option byte sequence */ 165#define OPT_CODE 0 166#define OPT_LEN 1 167#define OPT_DATA 2 168/* Bits in "overload" option */ 169#define OPTION_FIELD 0 170#define FILE_FIELD 1 171#define SNAME_FIELD 2 172 173/* DHCP_MESSAGE_TYPE values */ 174#define DHCPDISCOVER 1 /* client -> server */ 175#define DHCPOFFER 2 /* client <- server */ 176#define DHCPREQUEST 3 /* client -> server */ 177#define DHCPDECLINE 4 /* client -> server */ 178#define DHCPACK 5 /* client <- server */ 179#define DHCPNAK 6 /* client <- server */ 180#define DHCPRELEASE 7 /* client -> server */ 181#define DHCPINFORM 8 /* client -> server */ 182#define DHCP_MINTYPE DHCPDISCOVER 183#define DHCP_MAXTYPE DHCPINFORM 184 185struct dhcp_optflag { 186 uint8_t flags; 187 uint8_t code; 188}; 189 190struct option_set { 191 uint8_t *data; 192 struct option_set *next; 193}; 194 195extern const struct dhcp_optflag dhcp_optflags[]; 196extern const char dhcp_option_strings[] ALIGN1; 197extern const uint8_t dhcp_option_lengths[] ALIGN1; 198 199unsigned FAST_FUNC udhcp_option_idx(const char *name); 200 201uint8_t *udhcp_get_option(struct dhcp_packet *packet, int code) FAST_FUNC; 202int udhcp_end_option(uint8_t *optionptr) FAST_FUNC; 203void udhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt) FAST_FUNC; 204void udhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code, uint32_t data) FAST_FUNC; 205#if ENABLE_FEATURE_UDHCP_RFC3397 206char *dname_dec(const uint8_t *cstr, int clen, const char *pre) FAST_FUNC; 207uint8_t *dname_enc(const uint8_t *cstr, int clen, const char *src, int *retlen) FAST_FUNC; 208#endif 209struct option_set *udhcp_find_option(struct option_set *opt_list, uint8_t code) FAST_FUNC; 210 211 212// RFC 2131 Table 5: Fields and options used by DHCP clients 213// 214// Fields 'hops', 'yiaddr', 'siaddr', 'giaddr' are always zero 215// 216// Field DHCPDISCOVER DHCPINFORM DHCPREQUEST DHCPDECLINE DHCPRELEASE 217// ----- ------------ ------------ ----------- ----------- ----------- 218// 'xid' selected by client selected by client 'xid' from server selected by client selected by client 219// DHCPOFFER message 220// 'secs' 0 or seconds since 0 or seconds since 0 or seconds since 0 0 221// DHCP process started DHCP process started DHCP process started 222// 'flags' Set 'BROADCAST' Set 'BROADCAST' Set 'BROADCAST' 0 0 223// flag if client flag if client flag if client 224// requires broadcast requires broadcast requires broadcast 225// reply reply reply 226// 'ciaddr' 0 client's IP 0 or client's IP 0 client's IP 227// (BOUND/RENEW/REBIND) 228// 'chaddr' client's MAC client's MAC client's MAC client's MAC client's MAC 229// 'sname' options or sname options or sname options or sname (unused) (unused) 230// 'file' options or file options or file options or file (unused) (unused) 231// 'options' options options options message type opt message type opt 232// 233// Option DHCPDISCOVER DHCPINFORM DHCPREQUEST DHCPDECLINE DHCPRELEASE 234// ------ ------------ ---------- ----------- ----------- ----------- 235// Requested IP address MAY MUST NOT MUST (in MUST MUST NOT 236// SELECTING or 237// INIT-REBOOT) 238// MUST NOT (in 239// BOUND or 240// RENEWING) 241// IP address lease time MAY MUST NOT MAY MUST NOT MUST NOT 242// Use 'file'/'sname' fields MAY MAY MAY MAY MAY 243// Client identifier MAY MAY MAY MAY MAY 244// Vendor class identifier MAY MAY MAY MUST NOT MUST NOT 245// Server identifier MUST NOT MUST NOT MUST (after MUST MUST 246// SELECTING) 247// MUST NOT (after 248// INIT-REBOOT, 249// BOUND, RENEWING 250// or REBINDING) 251// Parameter request list MAY MAY MAY MUST NOT MUST NOT 252// Maximum message size MAY MAY MAY MUST NOT MUST NOT 253// Message SHOULD NOT SHOULD NOT SHOULD NOT SHOULD SHOULD 254// Site-specific MAY MAY MAY MUST NOT MUST NOT 255// All others MAY MAY MAY MUST NOT MUST NOT 256 257 258/*** Logging ***/ 259 260#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1 261# define IF_UDHCP_VERBOSE(...) __VA_ARGS__ 262extern unsigned dhcp_verbose; 263# define log1(...) do { if (dhcp_verbose >= 1) bb_info_msg(__VA_ARGS__); } while (0) 264# if CONFIG_UDHCP_DEBUG >= 2 265void udhcp_dump_packet(struct dhcp_packet *packet) FAST_FUNC; 266# define log2(...) do { if (dhcp_verbose >= 2) bb_info_msg(__VA_ARGS__); } while (0) 267# else 268# define udhcp_dump_packet(...) ((void)0) 269# define log2(...) ((void)0) 270# endif 271# if CONFIG_UDHCP_DEBUG >= 3 272# define log3(...) do { if (dhcp_verbose >= 3) bb_info_msg(__VA_ARGS__); } while (0) 273# else 274# define log3(...) ((void)0) 275# endif 276#else 277# define IF_UDHCP_VERBOSE(...) 278# define udhcp_dump_packet(...) ((void)0) 279# define log1(...) ((void)0) 280# define log2(...) ((void)0) 281# define log3(...) ((void)0) 282#endif 283 284 285/*** Other shared functions ***/ 286 287/* 2nd param is "uint32_t*" */ 288int FAST_FUNC udhcp_str2nip(const char *str, void *arg); 289/* 2nd param is "struct option_set**" */ 290int FAST_FUNC udhcp_str2optset(const char *str, void *arg); 291 292void udhcp_init_header(struct dhcp_packet *packet, char type) FAST_FUNC; 293 294int udhcp_recv_kernel_packet(struct dhcp_packet *packet, int fd) FAST_FUNC; 295 296int udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt, 297 uint32_t source_nip, int source_port, 298 uint32_t dest_nip, int dest_port, const uint8_t *dest_arp, 299 int ifindex) FAST_FUNC; 300 301int udhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt, 302 uint32_t source_nip, int source_port, 303 uint32_t dest_nip, int dest_port) FAST_FUNC; 304 305void udhcp_sp_setup(void) FAST_FUNC; 306int udhcp_sp_fd_set(fd_set *rfds, int extra_fd) FAST_FUNC; 307int udhcp_sp_read(const fd_set *rfds) FAST_FUNC; 308 309int udhcp_read_interface(const char *interface, int *ifindex, 310 uint32_t *nip, uint8_t *mac, uint16_t *mtu) FAST_FUNC; 311 312int udhcp_listen_socket(/*uint32_t ip,*/ int port, const char *inf) FAST_FUNC; 313 314/* Returns 1 if no reply received */ 315int arpping(uint32_t test_nip, 316 const uint8_t *safe_mac, 317 uint32_t from_ip, 318 uint8_t *from_mac, 319 const char *interface, 320 unsigned timeo) FAST_FUNC; 321 322/* note: ip is a pointer to an IPv6 in network order, possibly misaliged */ 323int sprint_nip6(char *dest, /*const char *pre,*/ const uint8_t *ip) FAST_FUNC; 324 325POP_SAVED_FUNCTION_VISIBILITY 326 327#endif 328