source: MondoRescue/branches/2.2.9/mindi-busybox/networking/udhcp/dhcpd.h@ 3320

/* vi: set sw=4 ts=4: */
/*
 * Licensed under GPLv2, see file LICENSE in this source tree.
 */
#ifndef UDHCP_DHCPD_H
#define UDHCP_DHCPD_H 1

PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN

/* Defaults you may want to tweak */
/* Default max_lease_sec */
#define DEFAULT_LEASE_TIME      (60*60*24 * 10)
#define LEASES_FILE             CONFIG_DHCPD_LEASES_FILE
/* Where to find the DHCP server configuration file */
#define DHCPD_CONF_FILE         "/etc/udhcpd.conf"


struct static_lease {
    struct static_lease *next;
    uint32_t nip;
    uint8_t mac[6];
};

struct server_config_t {
    char *interface;                /* interface to use */
//TODO: ifindex, server_nip, server_mac
// are obtained from interface name.
// Instead of querying them *once*, create update_server_network_data_cache()
// and call it before any usage of these fields.
// update_server_network_data_cache() must re-query data
// if more than N seconds have passed after last use.
    int ifindex;
    uint32_t server_nip;
#if ENABLE_FEATURE_UDHCP_PORT
    uint16_t port;
#endif
    uint8_t server_mac[6];          /* our MAC address (used only for ARP probing) */
    struct option_set *options;     /* list of DHCP options loaded from the config file */
    /* start,end are in host order: we need to compare start <= ip <= end */
    uint32_t start_ip;              /* start address of leases, in host order */
    uint32_t end_ip;                /* end of leases, in host order */
    uint32_t max_lease_sec;         /* maximum lease time (host order) */
    uint32_t min_lease_sec;         /* minimum lease time a client can request */
    uint32_t max_leases;            /* maximum number of leases (including reserved addresses) */
    uint32_t auto_time;             /* how long should udhcpd wait before writing a config file.
                                     * if this is zero, it will only write one on SIGUSR1 */
    uint32_t decline_time;          /* how long an address is reserved if a client returns a
                                     * decline message */
    uint32_t conflict_time;         /* how long an arp conflict offender is leased for */
    uint32_t offer_time;            /* how long an offered address is reserved */
    uint32_t siaddr_nip;            /* "next server" bootp option */
    char *lease_file;
    char *pidfile;
    char *notify_file;              /* what to run whenever leases are written */
    char *sname;                    /* bootp server name */
    char *boot_file;                /* bootp boot file option */
    struct static_lease *static_leases; /* List of ip/mac pairs to assign static leases */
} FIX_ALIASING;

#define server_config (*(struct server_config_t*)&bb_common_bufsiz1)
/* client_config sits in 2nd half of bb_common_bufsiz1 */

#if ENABLE_FEATURE_UDHCP_PORT
#define SERVER_PORT (server_config.port)
#else
#define SERVER_PORT 67
#endif


typedef uint32_t leasetime_t;
typedef int32_t signed_leasetime_t;

struct dyn_lease {
    /* Unix time when lease expires. Kept in memory in host order.
     * When written to file, converted to network order
     * and adjusted (current time subtracted) */
    leasetime_t expires;
    /* "nip": IP in network order */
    uint32_t lease_nip;
    /* We use lease_mac[6], since e.g. ARP probing uses
     * only 6 first bytes anyway. We check received dhcp packets
     * that their hlen == 6 and thus chaddr has only 6 significant bytes
     * (dhcp packet has chaddr[16], not [6])
     */
    uint8_t lease_mac[6];
    char hostname[20];
    uint8_t pad[2];
    /* total size is a multiply of 4 */
} PACKED;

extern struct dyn_lease *g_leases;

struct dyn_lease *add_lease(
        const uint8_t *chaddr, uint32_t yiaddr,
        leasetime_t leasetime,
        const char *hostname, int hostname_len
        ) FAST_FUNC;
int is_expired_lease(struct dyn_lease *lease) FAST_FUNC;
struct dyn_lease *find_lease_by_mac(const uint8_t *mac) FAST_FUNC;
struct dyn_lease *find_lease_by_nip(uint32_t nip) FAST_FUNC;
uint32_t find_free_or_expired_nip(const uint8_t *safe_mac) FAST_FUNC;


/* Config file parser will pass static lease info to this function
 * which will add it to a data structure that can be searched later */
void add_static_lease(struct static_lease **st_lease_pp, uint8_t *mac, uint32_t nip) FAST_FUNC;
/* Find static lease IP by mac */
uint32_t get_static_nip_by_mac(struct static_lease *st_lease, void *arg) FAST_FUNC;
/* Check to see if an IP is reserved as a static IP */
int is_nip_reserved(struct static_lease *st_lease, uint32_t nip) FAST_FUNC;
/* Print out static leases just to check what's going on (debug code) */
#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
void log_static_leases(struct static_lease **st_lease_pp) FAST_FUNC;
#else
# define log_static_leases(st_lease_pp) ((void)0)
#endif


void read_config(const char *file) FAST_FUNC;
void write_leases(void) FAST_FUNC;
void read_leases(const char *file) FAST_FUNC;


POP_SAVED_FUNCTION_VISIBILITY

#endif