hush/networking/udhcp/options.h
Denys Vlasenko c7dc79e71d udhcpd: untangle incredibly messy handling of DHCPREQUEST
Also fixes attacks possible via DHCPDECLINE / DHCPRELEASE

function                                             old     new   delta
udhcpd_main                                         1846    1949    +103
send_renew                                           105     142     +37
send_NAK                                              61       -     -61
send_ACK                                             180       -    -180
------------------------------------------------------------------------------
(add/remove: 0/2 grow/shrink: 2/0 up/down: 140/-241)         Total: -101 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2010-03-21 06:15:28 +01:00

120 lines
4.6 KiB
C

/* vi: set sw=4 ts=4: */
/* options.h */
#ifndef UDHCP_OPTIONS_H
#define UDHCP_OPTIONS_H 1
PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
enum {
OPTION_IP = 1,
OPTION_IP_PAIR,
OPTION_STRING,
#if ENABLE_FEATURE_UDHCP_RFC3397
OPTION_STR1035, /* RFC1035 compressed domain name list */
#endif
OPTION_BOOLEAN,
OPTION_U8,
OPTION_U16,
OPTION_S16,
OPTION_U32,
OPTION_S32,
OPTION_STATIC_ROUTES,
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_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_STATIC_ROUTES 0x79 /* RFC 3442. (mask,ip,router) tuples */
//#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_option {
uint8_t flags;
uint8_t code;
};
extern const struct dhcp_option dhcp_options[];
extern const char dhcp_option_strings[];
extern const uint8_t dhcp_option_lengths[];
uint8_t *get_option(struct dhcp_packet *packet, int code) FAST_FUNC;
int end_option(uint8_t *optionptr) FAST_FUNC;
void add_option_string(uint8_t *optionptr, uint8_t *string) FAST_FUNC;
void add_simple_option(uint8_t *optionptr, 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
POP_SAVED_FUNCTION_VISIBILITY
#endif