blob: 2c5f964bf83741d5988977f3346d6e0c96f854fd [file] [log] [blame]
/* dnsmasq is Copyright (c) 2000-2009 Simon Kelley
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 dated June, 1991, or
(at your option) version 3 dated 29 June, 2007.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <>.
#define COPYRIGHT "Copyright (C) 2000-2009 Simon Kelley"
/* Ensure we can use files >2GB (log files may grow this big) */
#define _FILE_OFFSET_BITS 64
/* Get linux C library versions. */
#ifdef __linux__
#ifndef __ANDROID__
#define _GNU_SOURCE
#include <features.h>
/* get these before config.h for IPv6 stuff... */
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/types.h>
#ifdef __APPLE__
#include <arpa/nameser_compat.h>
#include <nameser.h>
#ifdef __ANDROID__
#include "nameser.h"
#include <arpa/nameser.h>
/* and this. */
#include <getopt.h>
#include "config.h"
#define gettext_noop(S) (S)
#define _(S) (S)
#include <libintl.h>
#include <locale.h>
#define _(S) gettext(S)
#include <arpa/inet.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <limits.h>
#include <net/if.h>
#include <pwd.h>
#include <signal.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/select.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>
#if defined(__OpenBSD__) || defined(__NetBSD__) || defined(__sun__) || defined(__sun) || \
#include <netinet/if_ether.h>
#include <net/ethernet.h>
#include <dirent.h>
#include <net/if_arp.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <sys/uio.h>
#include <syslog.h>
#include <net/if_dl.h>
#include <linux/capability.h>
/* There doesn't seem to be a universally-available
userpace header for these. */
extern int capset(cap_user_header_t header, cap_user_data_t data);
extern int capget(cap_user_header_t header, cap_user_data_t data);
#define LINUX_CAPABILITY_VERSION_1 0x19980330
#define LINUX_CAPABILITY_VERSION_2 0x20071026
#define LINUX_CAPABILITY_VERSION_3 0x20080522
#include <sys/prctl.h>
/* daemon is function in the C library.... */
#define daemon dnsmasq_daemon
/* Async event queue */
struct event_desc {
int event, data;
#define EVENT_RELOAD 1
#define EVENT_DUMP 2
#define EVENT_ALARM 3
#define EVENT_TERM 4
#define EVENT_CHILD 5
#define EVENT_REOPEN 6
#define EVENT_EXITED 7
#define EVENT_KILLED 8
#define EVENT_EXEC_ERR 9
#define EVENT_PIPE_ERR 10
#define EVENT_USER_ERR 11
#define EVENT_CAP_ERR 12
#define EVENT_PIDFILE 13
#define EVENT_HUSER_ERR 14
#define EVENT_GROUP_ERR 15
#define EVENT_DIE 16
#define EVENT_LOG_ERR 17
#define EVENT_FORK_ERR 18
/* Exit codes. */
#define EC_GOOD 0
#define EC_BADCONF 1
#define EC_BADNET 2
#define EC_FILE 3
#define EC_NOMEM 4
#define EC_MISC 5
#define EC_INIT_OFFSET 10
/* Min buffer size: we check after adding each record, so there must be
memory for the largest packet, and the largest record so the
min for DNS is PACKETSZ+MAXDNAME+RRFIXEDSZ which is < 1000.
This might be increased is EDNS packet size if greater than the minimum.
#define OPT_BOGUSPRIV (1u << 0)
#define OPT_FILTER (1u << 1)
#define OPT_LOG (1u << 2)
#define OPT_SELFMX (1u << 3)
#define OPT_NO_HOSTS (1u << 4)
#define OPT_NO_POLL (1u << 5)
#define OPT_DEBUG (1u << 6)
#define OPT_ORDER (1u << 7)
#define OPT_NO_RESOLV (1u << 8)
#define OPT_EXPAND (1u << 9)
#define OPT_LOCALMX (1u << 10)
#define OPT_NO_NEG (1u << 11)
#define OPT_NODOTS_LOCAL (1u << 12)
#define OPT_NOWILD (1u << 13)
#define OPT_RESOLV_DOMAIN (1u << 15)
#define OPT_NO_FORK (1u << 16)
#define OPT_AUTHORITATIVE (1u << 17)
#define OPT_LOCALISE (1u << 18)
#define OPT_DBUS (1u << 19)
#define OPT_DHCP_FQDN (1u << 20)
#define OPT_NO_PING (1u << 21)
#define OPT_LEASE_RO (1u << 22)
#define OPT_ALL_SERVERS (1u << 23)
#define OPT_RELOAD (1u << 24)
#define OPT_TFTP (1u << 25)
#define OPT_TFTP_SECURE (1u << 26)
#define OPT_TFTP_NOBLOCK (1u << 27)
#define OPT_LOG_OPTS (1u << 28)
#define OPT_TFTP_APREF (1u << 29)
#define OPT_NO_OVERRIDE (1u << 30)
#define OPT_NO_REBIND (1u << 31)
/* extra flags for my_syslog, we use a couple of facilities since they are known
not to occupy the same bits as priorities, no matter how syslog.h is set up. */
struct all_addr {
union {
struct in_addr addr4;
#ifdef HAVE_IPV6
struct in6_addr addr6;
} addr;
struct bogus_addr {
struct in_addr addr;
struct bogus_addr* next;
/* dns doctor param */
struct doctor {
struct in_addr in, end, out, mask;
struct doctor* next;
struct mx_srv_record {
char *name, *target;
int issrv, srvport, priority, weight;
unsigned int offset;
struct mx_srv_record* next;
struct naptr {
char *name, *replace, *regexp, *services, *flags;
unsigned int order, pref;
struct naptr* next;
struct txt_record {
char *name, *txt;
unsigned short class, len;
struct txt_record* next;
struct ptr_record {
char *name, *ptr;
struct ptr_record* next;
struct cname {
char *alias, *target;
struct cname* next;
struct interface_name {
char* name; /* domain name */
char* intr; /* interface name */
struct interface_name* next;
union bigname {
char name[MAXDNAME];
union bigname* next; /* freelist */
struct crec {
struct crec *next, *prev, *hash_next;
time_t ttd; /* time to die */
int uid;
union {
struct all_addr addr;
struct {
struct crec* cache;
int uid;
} cname;
} addr;
unsigned short flags;
union {
char sname[SMALLDNAME];
union bigname* bname;
char* namep;
} name;
#define F_IMMORTAL 1
#define F_CONFIG 2
#define F_REVERSE 4
#define F_FORWARD 8
#define F_DHCP 16
#define F_NEG 32
#define F_HOSTS 64
#define F_IPV4 128
#define F_IPV6 256
#define F_BIGNAME 512
#define F_UPSTREAM 1024
#define F_SERVER 2048
#define F_NXDOMAIN 4096
#define F_QUERY 8192
#define F_CNAME 16384
#define F_NOERR 32768
/* struct sockaddr is not large enough to hold any address,
and specifically not big enough to hold an IPv6 address.
Blech. Roll our own. */
union mysockaddr {
struct sockaddr sa;
struct sockaddr_in in;
#if defined(HAVE_IPV6)
struct sockaddr_in6 in6;
#define SERV_FROM_RESOLV 1 /* 1 for servers from resolv, 0 for command line. */
#define SERV_NO_ADDR 2 /* no server, this domain is local only */
#define SERV_LITERAL_ADDRESS 4 /* addr is the answer, not the server */
#define SERV_HAS_DOMAIN 8 /* server for one domain only */
#define SERV_HAS_SOURCE 16 /* source address defined */
#define SERV_FOR_NODOTS 32 /* server for names with no domain part only */
#define SERV_WARNED_RECURSIVE 64 /* avoid warning spam */
#define SERV_FROM_DBUS 128 /* 1 if source is DBus */
#define SERV_MARK 256 /* for mark-and-delete */
#define SERV_COUNTED 512 /* workspace for log code */
struct serverfd {
int fd;
union mysockaddr source_addr;
char interface[IF_NAMESIZE + 1];
struct serverfd* next;
uint32_t mark;
struct randfd {
int fd;
unsigned short refcount, family;
struct server {
union mysockaddr addr, source_addr;
char interface[IF_NAMESIZE + 1];
struct serverfd* sfd;
char* domain; /* set if this server only handles a domain. */
int flags, tcpfd;
unsigned int queries, failed_queries;
uint32_t mark;
struct server* next;
struct irec {
union mysockaddr addr;
struct in_addr netmask; /* only valid for IPv4 */
int dhcp_ok, mtu;
struct irec* next;
struct listener {
int fd, tcpfd, family;
struct irec* iface; /* only valid for non-wildcard */
struct listener* next;
/* interface and address parms from command line. */
struct iname {
char* name;
union mysockaddr addr;
int isloop, used;
struct iname* next;
/* resolv-file parms from command-line */
struct resolvc {
struct resolvc* next;
int is_default, logged;
time_t mtime;
char* name;
/* adn-hosts parms from command-line */
#define AH_DIR 1
#define AH_INACTIVE 2
struct hostsfile {
struct hostsfile* next;
int flags;
char* fname;
int index; /* matches to cache entries for logging */
struct frec {
union mysockaddr source;
struct all_addr dest;
struct server* sentto; /* NULL means free */
struct randfd* rfd4;
#ifdef HAVE_IPV6
struct randfd* rfd6;
unsigned int iface;
unsigned short orig_id, new_id;
int fd, forwardall;
unsigned int crc;
time_t time;
struct frec* next;
/* actions in the daemon->helper RPC */
#define ACTION_DEL 1
#define ACTION_OLD 3
#define ACTION_ADD 4
#define DHCP_CHADDR_MAX 16
struct dhcp_lease {
int clid_len; /* length of client identifier */
unsigned char* clid; /* clientid */
char *hostname, *fqdn; /* name from client-hostname option or config */
char* old_hostname; /* hostname before it moved to another lease */
char auth_name; /* hostname came from config, not from client */
char new; /* newly created */
char changed; /* modified */
char aux_changed; /* CLID or expiry changed */
time_t expires; /* lease expiry */
unsigned int length;
int hwaddr_len, hwaddr_type;
unsigned char hwaddr[DHCP_CHADDR_MAX];
struct in_addr addr, override, giaddr;
unsigned char *vendorclass, *userclass, *supplied_hostname;
unsigned int vendorclass_len, userclass_len, supplied_hostname_len;
int last_interface;
struct dhcp_lease* next;
struct dhcp_netid {
char* net;
struct dhcp_netid* next;
struct dhcp_netid_list {
struct dhcp_netid* list;
struct dhcp_netid_list* next;
struct hwaddr_config {
int hwaddr_len, hwaddr_type;
unsigned char hwaddr[DHCP_CHADDR_MAX];
unsigned int wildcard_mask;
struct hwaddr_config* next;
struct dhcp_config {
unsigned int flags;
int clid_len; /* length of client identifier */
unsigned char* clid; /* clientid */
char *hostname, *domain;
struct dhcp_netid netid;
struct in_addr addr;
time_t decline_time;
unsigned int lease_time;
struct hwaddr_config* hwaddr;
struct dhcp_config* next;
#define CONFIG_CLID 2
#define CONFIG_TIME 8
#define CONFIG_NAME 16
#define CONFIG_ADDR 32
#define CONFIG_NETID 64
#define CONFIG_NOCLID 128
#define CONFIG_ADDR_HOSTS 512 /* address added by from /etc/hosts */
#define CONFIG_DECLINED 1024 /* address declined by client */
#define CONFIG_BANK 2048 /* from dhcp hosts file */
struct dhcp_opt {
int opt, len, flags;
union {
int encap;
unsigned int wildcard_mask;
unsigned char* vendor_class;
} u;
unsigned char* val;
struct dhcp_netid* netid;
struct dhcp_opt* next;
#define DHOPT_ADDR 1
#define DHOPT_STRING 2
#define DHOPT_FORCE 16
#define DHOPT_BANK 32
#define DHOPT_MATCH 128
#define DHOPT_VENDOR 256
#define DHOPT_HEX 512
struct dhcp_boot {
char *file, *sname;
struct in_addr next_server;
struct dhcp_netid* netid;
struct dhcp_boot* next;
struct pxe_service {
unsigned short CSA, type;
char *menu, *basename;
struct in_addr server;
struct dhcp_netid* netid;
struct pxe_service* next;
#define MATCH_VENDOR 1
#define MATCH_USER 2
#define MATCH_REMOTE 4
/* vendorclass, userclass, remote-id or cicuit-id */
struct dhcp_vendor {
int len, match_type, option;
char* data;
struct dhcp_netid netid;
struct dhcp_vendor* next;
struct dhcp_mac {
unsigned int mask;
int hwaddr_len, hwaddr_type;
unsigned char hwaddr[DHCP_CHADDR_MAX];
struct dhcp_netid netid;
struct dhcp_mac* next;
struct dhcp_bridge {
char iface[IF_NAMESIZE];
struct dhcp_bridge *alias, *next;
struct cond_domain {
char* domain;
struct in_addr start, end;
struct cond_domain* next;
struct dhcp_context {
unsigned int lease_time, addr_epoch;
struct in_addr netmask, broadcast;
struct in_addr local, router;
struct in_addr start, end; /* range of available addresses */
int flags;
struct dhcp_netid netid, *filter;
struct dhcp_context *next, *current;
typedef unsigned char u8;
typedef unsigned short u16;
typedef unsigned int u32;
struct dhcp_packet {
u8 op, htype, hlen, hops;
u32 xid;
u16 secs, flags;
struct in_addr ciaddr, yiaddr, siaddr, giaddr;
u8 chaddr[DHCP_CHADDR_MAX], sname[64], file[128];
u8 options[312];
struct ping_result {
struct in_addr addr;
time_t time;
struct ping_result* next;
extern struct daemon {
/* datastuctures representing the command-line and
config file arguments. All set (including defaults)
in option.c */
unsigned int options;
struct resolvc default_resolv, *resolv_files;
time_t last_resolv;
struct mx_srv_record* mxnames;
struct naptr* naptr;
struct txt_record* txt;
struct ptr_record* ptr;
struct cname* cnames;
struct interface_name* int_names;
char* mxtarget;
char* lease_file;
char *username, *groupname, *scriptuser;
int group_set, osport;
char* domain_suffix;
struct cond_domain* cond_domain;
char* runfile;
char* lease_change_command;
struct iname *if_names, *if_addrs, *if_except, *dhcp_except;
struct bogus_addr* bogus_addr;
struct server* servers;
int log_fac; /* log facility */
char* log_file; /* optional log file */
int max_logs; /* queue limit */
int cachesize, ftabsize;
int port, query_port, min_port;
unsigned long local_ttl, neg_ttl;
struct hostsfile* addn_hosts;
struct dhcp_context* dhcp;
struct dhcp_config* dhcp_conf;
struct dhcp_opt *dhcp_opts, *dhcp_match;
struct dhcp_vendor* dhcp_vendors;
struct dhcp_mac* dhcp_macs;
struct dhcp_boot* boot_config;
struct pxe_service* pxe_services;
int enable_pxe;
struct dhcp_netid_list *dhcp_ignore, *dhcp_ignore_names, *force_broadcast, *bootp_dynamic;
char *dhcp_hosts_file, *dhcp_opts_file;
int dhcp_max;
int dhcp_server_port, dhcp_client_port;
unsigned int min_leasetime;
struct doctor* doctors;
unsigned short edns_pktsz;
uint32_t listen_mark;
/* globally used stuff for DNS */
char* packet; /* packet buffer */
int packet_buff_sz; /* size of above */
char* namebuff; /* MAXDNAME size buffer */
unsigned int local_answer, queries_forwarded;
struct frec* frec_list;
struct serverfd* sfds;
struct irec* interfaces;
struct listener* listeners;
struct server* last_server;
time_t forwardtime;
int forwardcount;
struct server* srv_save; /* Used for resend on DoD */
size_t packet_len; /* " " */
struct randfd* rfd_save; /* " " */
pid_t tcp_pids[MAX_PROCS];
struct randfd randomsocks[RANDOM_SOCKS];
/* DHCP state */
int dhcpfd, helperfd;
int netlinkfd;
struct iovec dhcp_packet;
char *dhcp_buff, *dhcp_buff2;
struct ping_result* ping_results;
FILE* lease_stream;
struct dhcp_bridge* bridges;
} * daemon;
/* cache.c */
void cache_init(void);
void log_query(unsigned short flags, char* name, struct all_addr* addr, char* arg);
char* record_source(int index);
void querystr(char* str, unsigned short type);
struct crec* cache_find_by_addr(struct crec* crecp, struct all_addr* addr, time_t now,
unsigned short prot);
struct crec* cache_find_by_name(struct crec* crecp, char* name, time_t now, unsigned short prot);
void cache_end_insert(void);
void cache_start_insert(void);
struct crec* cache_insert(char* name, struct all_addr* addr, time_t now, unsigned long ttl,
unsigned short flags);
void cache_reload(void);
void cache_add_dhcp_entry(char* host_name, struct in_addr* host_address, time_t ttd);
void cache_unhash_dhcp(void);
void dump_cache(time_t now);
char* cache_get_name(struct crec* crecp);
char* get_domain(struct in_addr addr);
/* rfc1035.c */
unsigned short extract_request(HEADER* header, size_t qlen, char* name, unsigned short* typep);
size_t setup_reply(HEADER* header, size_t qlen, struct all_addr* addrp, unsigned short flags,
unsigned long local_ttl);
int extract_addresses(HEADER* header, size_t qlen, char* namebuff, time_t now);
size_t answer_request(HEADER* header, char* limit, size_t qlen, struct in_addr local_addr,
struct in_addr local_netmask, time_t now);
int check_for_bogus_wildcard(HEADER* header, size_t qlen, char* name, struct bogus_addr* addr,
time_t now);
unsigned char* find_pseudoheader(HEADER* header, size_t plen, size_t* len, unsigned char** p,
int* is_sign);
int check_for_local_domain(char* name, time_t now);
unsigned int questions_crc(HEADER* header, size_t plen, char* buff);
size_t resize_packet(HEADER* header, size_t plen, unsigned char* pheader, size_t hlen);
/* util.c */
void rand_init(void);
unsigned short rand16(void);
int legal_hostname(char* c);
char* canonicalise(char* s, int* nomem);
unsigned char* do_rfc1035_name(unsigned char* p, char* sval);
void* safe_malloc(size_t size);
void safe_pipe(int* fd, int read_noblock);
void* whine_malloc(size_t size);
int sa_len(union mysockaddr* addr);
int sockaddr_isequal(union mysockaddr* s1, union mysockaddr* s2);
int hostname_isequal(char* a, char* b);
time_t dnsmasq_time(void);
int is_same_net(struct in_addr a, struct in_addr b, struct in_addr mask);
int retry_send(void);
int parse_addr(int family, const char* addrstr, union mysockaddr* addr);
void prettyprint_time(char* buf, unsigned int t);
int prettyprint_addr(const union mysockaddr* addr, char* buf);
int parse_hex(char* in, unsigned char* out, int maxlen, unsigned int* wildcard_mask, int* mac_type);
int memcmp_masked(unsigned char* a, unsigned char* b, int len, unsigned int mask);
int expand_buf(struct iovec* iov, size_t size);
char* print_mac(char* buff, unsigned char* mac, int len);
void bump_maxfd(int fd, int* max);
int read_write(int fd, unsigned char* packet, int size, int rw);
/* log.c */
void die(char* message, char* arg1, int exit_code);
int log_start(struct passwd* ent_pw, int errfd);
int log_reopen(char* log_file);
void my_syslog(int priority, const char* format, ...);
void set_log_writer(fd_set* set, int* maxfdp);
void check_log_writer(fd_set* set);
void flush_log(void);
/* option.c */
void read_opts(int argc, char** argv, char* compile_opts);
char* option_string(unsigned char opt, int* is_ip, int* is_name);
void reread_dhcp(void);
/* forward.c */
void reply_query(int fd, int family, time_t now);
void receive_query(struct listener* listen, time_t now);
unsigned char* tcp_request(int confd, time_t now, struct in_addr local_addr, struct in_addr netmask);
void server_gone(struct server* server);
struct frec* get_new_frec(time_t now, int* wait);
/* network.c */
int indextoname(int fd, int index, char* name);
int local_bind(int fd, union mysockaddr* addr, char* intname, uint32_t mark, int is_tcp);
int random_sock(int family);
void pre_allocate_sfds(void);
int reload_servers(char* fname);
#ifdef __ANDROID__
int set_servers(const char* servers);
void set_interfaces(const char* interfaces);
void check_servers(void);
int enumerate_interfaces();
struct listener* create_wildcard_listeners(void);
struct listener* create_bound_listeners(void);
int iface_check(int family, struct all_addr* addr, char* name, int* indexp);
int fix_fd(int fd);
struct in_addr get_ifaddr(char* intr);
/* dhcp.c */
#ifdef HAVE_DHCP
void dhcp_init(void);
void dhcp_packet(time_t now);
struct dhcp_context* address_available(struct dhcp_context* context, struct in_addr addr,
struct dhcp_netid* netids);
struct dhcp_context* narrow_context(struct dhcp_context* context, struct in_addr taddr,
struct dhcp_netid* netids);
int match_netid(struct dhcp_netid* check, struct dhcp_netid* pool, int negonly);
int address_allocate(struct dhcp_context* context, struct in_addr* addrp, unsigned char* hwaddr,
int hw_len, struct dhcp_netid* netids, time_t now);
int config_has_mac(struct dhcp_config* config, unsigned char* hwaddr, int len, int type);
struct dhcp_config* find_config(struct dhcp_config* configs, struct dhcp_context* context,
unsigned char* clid, int clid_len, unsigned char* hwaddr,
int hw_len, int hw_type, char* hostname);
void dhcp_update_configs(struct dhcp_config* configs);
void check_dhcp_hosts(int fatal);
struct dhcp_config* config_find_by_address(struct dhcp_config* configs, struct in_addr addr);
char* strip_hostname(char* hostname);
char* host_from_dns(struct in_addr addr);
char* get_domain(struct in_addr addr);
/* lease.c */
#ifdef HAVE_DHCP
void lease_update_file(time_t now);
void lease_update_dns();
void lease_init(time_t now);
struct dhcp_lease* lease_allocate(struct in_addr addr);
void lease_set_hwaddr(struct dhcp_lease* lease, unsigned char* hwaddr, unsigned char* clid,
int hw_len, int hw_type, int clid_len);
void lease_set_hostname(struct dhcp_lease* lease, char* name, int auth);
void lease_set_expires(struct dhcp_lease* lease, unsigned int len, time_t now);
void lease_set_interface(struct dhcp_lease* lease, int interface);
struct dhcp_lease* lease_find_by_client(unsigned char* hwaddr, int hw_len, int hw_type,
unsigned char* clid, int clid_len);
struct dhcp_lease* lease_find_by_addr(struct in_addr addr);
void lease_prune(struct dhcp_lease* target, time_t now);
void lease_update_from_configs(void);
int do_script_run(time_t now);
void rerun_scripts(void);
/* rfc2131.c */
#ifdef HAVE_DHCP
size_t dhcp_reply(struct dhcp_context* context, char* iface_name, int int_index, size_t sz,
time_t now, int unicast_dest, int* is_inform);
unsigned char* extended_hwaddr(int hwtype, int hwlen, unsigned char* hwaddr, int clid_len,
unsigned char* clid, int* len_out);
/* dnsmasq.c */
#ifdef HAVE_DHCP
int make_icmp_sock(void);
int icmp_ping(struct in_addr addr);
void send_event(int fd, int event, int data);
void clear_cache_and_reload(time_t now);
/* netlink.c */
void netlink_init(void);
void netlink_multicast(void);
/* bpf.c or netlink.c */
int iface_enumerate(void* parm, int (*ipv4_callback)(), int (*ipv6_callback)());
/* helper.c */
#if defined(HAVE_DHCP) && !defined(NO_FORK)
int create_helper(int event_fd, int err_fd, uid_t uid, gid_t gid, long max_fd);
void helper_write(void);
void queue_script(int action, struct dhcp_lease* lease, char* hostname, time_t now);
int helper_buf_empty(void);