/* vi: set sw=4 ts=4: */ /* * Russ Dill <Russ.Dill@asu.edu> September 2001 * Rewritten by Vladimir Oleynik <dzo@simtreas.ru> (C) 2003 * * Licensed under GPLv2 or later, see file LICENSE in this source tree. */ #ifndef UDHCP_COMMON_H #define UDHCP_COMMON_H 1 #include "libbb.h" #include <netinet/udp.h> #include <netinet/ip.h> PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN extern const uint8_t MAC_BCAST_ADDR[6]; /* six all-ones */ /*** DHCP packet ***/ /* DHCP protocol. See RFC 2131 */ #define DHCP_MAGIC 0x63825363 #define DHCP_OPTIONS_BUFSIZE 308 #define BOOTREQUEST 1 #define BOOTREPLY 2 //TODO: rename ciaddr/yiaddr/chaddr struct dhcp_packet { uint8_t op; /* BOOTREQUEST or BOOTREPLY */ uint8_t htype; /* hardware address type. 1 = 10mb ethernet */ uint8_t hlen; /* hardware address length */ uint8_t hops; /* used by relay agents only */ uint32_t xid; /* unique id */ uint16_t secs; /* elapsed since client began acquisition/renewal */ uint16_t flags; /* only one flag so far: */ #define BROADCAST_FLAG 0x8000 /* "I need broadcast replies" */ uint32_t ciaddr; /* client IP (if client is in BOUND, RENEW or REBINDING state) */ uint32_t yiaddr; /* 'your' (client) IP address */ /* IP address of next server to use in bootstrap, returned in DHCPOFFER, DHCPACK by server */ uint32_t siaddr_nip; uint32_t gateway_nip; /* relay agent IP address */ uint8_t chaddr[16]; /* link-layer client hardware address (MAC) */ uint8_t sname[64]; /* server host name (ASCIZ) */ uint8_t file[128]; /* boot file name (ASCIZ) */ uint32_t cookie; /* fixed first four option bytes (99,130,83,99 dec) */ uint8_t options[DHCP_OPTIONS_BUFSIZE + CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS]; } PACKED; #define DHCP_PKT_SNAME_LEN 64 #define DHCP_PKT_FILE_LEN 128 #define DHCP_PKT_SNAME_LEN_STR "64" #define DHCP_PKT_FILE_LEN_STR "128" struct ip_udp_dhcp_packet { struct iphdr ip; struct udphdr udp; struct dhcp_packet data; } PACKED; struct udp_dhcp_packet { struct udphdr udp; struct dhcp_packet data; } PACKED; enum { IP_UDP_DHCP_SIZE = sizeof(struct ip_udp_dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS, UDP_DHCP_SIZE = sizeof(struct udp_dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS, DHCP_SIZE = sizeof(struct dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS, }; /* Let's see whether compiler understood us right */ struct BUG_bad_sizeof_struct_ip_udp_dhcp_packet { char c[IP_UDP_DHCP_SIZE == 576 ? 1 : -1]; }; /*** Options ***/ enum { OPTION_IP = 1, OPTION_IP_PAIR, OPTION_STRING, // OPTION_BOOLEAN, OPTION_U8, OPTION_U16, // OPTION_S16, OPTION_U32, OPTION_S32, OPTION_BIN, OPTION_STATIC_ROUTES, #if ENABLE_FEATURE_UDHCP_RFC3397 OPTION_DNS_STRING, /* RFC1035 compressed domain name list */ OPTION_SIP_SERVERS, #endif OPTION_TYPE_MASK = 0x0f, /* Client requests this option by default */ OPTION_REQ = 0x10, /* There can be a list of 1 or more of these */ OPTION_LIST = 0x20, }; /* DHCP option codes (partial list). See RFC 2132 and * http://www.iana.org/assignments/bootp-dhcp-parameters/ * Commented out options are handled by common option machinery, * uncommented ones have spacial cases (grep for them to see). */ #define DHCP_PADDING 0x00 #define DHCP_SUBNET 0x01 //#define DHCP_TIME_OFFSET 0x02 /* (localtime - UTC_time) in seconds. signed */ //#define DHCP_ROUTER 0x03 //#define DHCP_TIME_SERVER 0x04 /* RFC 868 time server (32-bit, 0 = 1.1.1900) */ //#define DHCP_NAME_SERVER 0x05 /* IEN 116 _really_ ancient kind of NS */ //#define DHCP_DNS_SERVER 0x06 //#define DHCP_LOG_SERVER 0x07 /* port 704 UDP log (not syslog) //#define DHCP_COOKIE_SERVER 0x08 /* "quote of the day" server */ //#define DHCP_LPR_SERVER 0x09 #define DHCP_HOST_NAME 0x0c /* either client informs server or server gives name to client */ //#define DHCP_BOOT_SIZE 0x0d //#define DHCP_DOMAIN_NAME 0x0f /* server gives domain suffix */ //#define DHCP_SWAP_SERVER 0x10 //#define DHCP_ROOT_PATH 0x11 //#define DHCP_IP_TTL 0x17 //#define DHCP_MTU 0x1a //#define DHCP_BROADCAST 0x1c //#define DHCP_ROUTES 0x21 //#define DHCP_NIS_DOMAIN 0x28 //#define DHCP_NIS_SERVER 0x29 //#define DHCP_NTP_SERVER 0x2a //#define DHCP_WINS_SERVER 0x2c #define DHCP_REQUESTED_IP 0x32 /* sent by client if specific IP is wanted */ #define DHCP_LEASE_TIME 0x33 #define DHCP_OPTION_OVERLOAD 0x34 #define DHCP_MESSAGE_TYPE 0x35 #define DHCP_SERVER_ID 0x36 /* by default server's IP */ #define DHCP_PARAM_REQ 0x37 /* list of options client wants */ //#define DHCP_ERR_MESSAGE 0x38 /* error message when sending NAK etc */ #define DHCP_MAX_SIZE 0x39 #define DHCP_VENDOR 0x3c /* client's vendor (a string) */ #define DHCP_CLIENT_ID 0x3d /* by default client's MAC addr, but may be arbitrarily long */ //#define DHCP_TFTP_SERVER_NAME 0x42 /* same as 'sname' field */ //#define DHCP_BOOT_FILE 0x43 /* same as 'file' field */ //#define DHCP_USER_CLASS 0x4d /* RFC 3004. set of LASCII strings. "I am a printer" etc */ #define DHCP_FQDN 0x51 /* client asks to update DNS to map its FQDN to its new IP */ //#define DHCP_DOMAIN_SEARCH 0x77 /* RFC 3397. set of ASCIZ string, DNS-style compressed */ //#define DHCP_SIP_SERVERS 0x78 /* RFC 3361. flag byte, then: 0: domain names, 1: IP addrs */ //#define DHCP_STATIC_ROUTES 0x79 /* RFC 3442. (mask,ip,router) tuples */ //#define DHCP_MS_STATIC_ROUTES 0xf9 /* Microsoft's pre-RFC 3442 code for 0x79? */ //#define DHCP_WPAD 0xfc /* MSIE's Web Proxy Autodiscovery Protocol */ #define DHCP_END 0xff /* Offsets in option byte sequence */ #define OPT_CODE 0 #define OPT_LEN 1 #define OPT_DATA 2 /* Bits in "overload" option */ #define OPTION_FIELD 0 #define FILE_FIELD 1 #define SNAME_FIELD 2 /* DHCP_MESSAGE_TYPE values */ #define DHCPDISCOVER 1 /* client -> server */ #define DHCPOFFER 2 /* client <- server */ #define DHCPREQUEST 3 /* client -> server */ #define DHCPDECLINE 4 /* client -> server */ #define DHCPACK 5 /* client <- server */ #define DHCPNAK 6 /* client <- server */ #define DHCPRELEASE 7 /* client -> server */ #define DHCPINFORM 8 /* client -> server */ #define DHCP_MINTYPE DHCPDISCOVER #define DHCP_MAXTYPE DHCPINFORM struct dhcp_optflag { uint8_t flags; uint8_t code; }; struct option_set { uint8_t *data; struct option_set *next; }; extern const struct dhcp_optflag dhcp_optflags[]; extern const char dhcp_option_strings[]; extern const uint8_t dhcp_option_lengths[]; unsigned FAST_FUNC udhcp_option_idx(const char *name); uint8_t *udhcp_get_option(struct dhcp_packet *packet, int code) FAST_FUNC; int udhcp_end_option(uint8_t *optionptr) FAST_FUNC; void udhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt) FAST_FUNC; void udhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code, uint32_t data) FAST_FUNC; #if ENABLE_FEATURE_UDHCP_RFC3397 char *dname_dec(const uint8_t *cstr, int clen, const char *pre) FAST_FUNC; uint8_t *dname_enc(const uint8_t *cstr, int clen, const char *src, int *retlen) FAST_FUNC; #endif struct option_set *udhcp_find_option(struct option_set *opt_list, uint8_t code) FAST_FUNC; // RFC 2131 Table 5: Fields and options used by DHCP clients // // Fields 'hops', 'yiaddr', 'siaddr', 'giaddr' are always zero // // Field DHCPDISCOVER DHCPINFORM DHCPREQUEST DHCPDECLINE DHCPRELEASE // ----- ------------ ------------ ----------- ----------- ----------- // 'xid' selected by client selected by client 'xid' from server selected by client selected by client // DHCPOFFER message // 'secs' 0 or seconds since 0 or seconds since 0 or seconds since 0 0 // DHCP process started DHCP process started DHCP process started // 'flags' Set 'BROADCAST' Set 'BROADCAST' Set 'BROADCAST' 0 0 // flag if client flag if client flag if client // requires broadcast requires broadcast requires broadcast // reply reply reply // 'ciaddr' 0 client's IP 0 or client's IP 0 client's IP // (BOUND/RENEW/REBIND) // 'chaddr' client's MAC client's MAC client's MAC client's MAC client's MAC // 'sname' options or sname options or sname options or sname (unused) (unused) // 'file' options or file options or file options or file (unused) (unused) // 'options' options options options message type opt message type opt // // Option DHCPDISCOVER DHCPINFORM DHCPREQUEST DHCPDECLINE DHCPRELEASE // ------ ------------ ---------- ----------- ----------- ----------- // Requested IP address MAY MUST NOT MUST (in MUST MUST NOT // SELECTING or // INIT-REBOOT) // MUST NOT (in // BOUND or // RENEWING) // IP address lease time MAY MUST NOT MAY MUST NOT MUST NOT // Use 'file'/'sname' fields MAY MAY MAY MAY MAY // Client identifier MAY MAY MAY MAY MAY // Vendor class identifier MAY MAY MAY MUST NOT MUST NOT // Server identifier MUST NOT MUST NOT MUST (after MUST MUST // SELECTING) // MUST NOT (after // INIT-REBOOT, // BOUND, RENEWING // or REBINDING) // Parameter request list MAY MAY MAY MUST NOT MUST NOT // Maximum message size MAY MAY MAY MUST NOT MUST NOT // Message SHOULD NOT SHOULD NOT SHOULD NOT SHOULD SHOULD // Site-specific MAY MAY MAY MUST NOT MUST NOT // All others MAY MAY MAY MUST NOT MUST NOT /*** Logging ***/ #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1 extern unsigned dhcp_verbose; # define log1(...) do { if (dhcp_verbose >= 1) bb_info_msg(__VA_ARGS__); } while (0) # if CONFIG_UDHCP_DEBUG >= 2 void udhcp_dump_packet(struct dhcp_packet *packet) FAST_FUNC; # define log2(...) do { if (dhcp_verbose >= 2) bb_info_msg(__VA_ARGS__); } while (0) # else # define udhcp_dump_packet(...) ((void)0) # define log2(...) ((void)0) # endif # if CONFIG_UDHCP_DEBUG >= 3 # define log3(...) do { if (dhcp_verbose >= 3) bb_info_msg(__VA_ARGS__); } while (0) # else # define log3(...) ((void)0) # endif #else # define udhcp_dump_packet(...) ((void)0) # define log1(...) ((void)0) # define log2(...) ((void)0) # define log3(...) ((void)0) #endif /*** Other shared functions ***/ /* 2nd param is "uint32_t*" */ int FAST_FUNC udhcp_str2nip(const char *str, void *arg); /* 2nd param is "struct option_set**" */ int FAST_FUNC udhcp_str2optset(const char *str, void *arg); uint16_t udhcp_checksum(void *addr, int count) FAST_FUNC; void udhcp_init_header(struct dhcp_packet *packet, char type) FAST_FUNC; int udhcp_recv_kernel_packet(struct dhcp_packet *packet, int fd) FAST_FUNC; int udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt, uint32_t source_nip, int source_port, uint32_t dest_nip, int dest_port, const uint8_t *dest_arp, int ifindex) FAST_FUNC; int udhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt, uint32_t source_nip, int source_port, uint32_t dest_nip, int dest_port) FAST_FUNC; void udhcp_sp_setup(void) FAST_FUNC; int udhcp_sp_fd_set(fd_set *rfds, int extra_fd) FAST_FUNC; int udhcp_sp_read(const fd_set *rfds) FAST_FUNC; int udhcp_read_interface(const char *interface, int *ifindex, uint32_t *nip, uint8_t *mac) FAST_FUNC; int udhcp_listen_socket(/*uint32_t ip,*/ int port, const char *inf) FAST_FUNC; /* Returns 1 if no reply received */ int arpping(uint32_t test_nip, const uint8_t *safe_mac, uint32_t from_ip, uint8_t *from_mac, const char *interface) FAST_FUNC; POP_SAVED_FUNCTION_VISIBILITY #endif