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GCC Code Coverage Report
Directory:	./		Exec	Total	Coverage
File:	sbin/dhclient/dhclient.c	Lines:	0	1281	0.0 %
Date:	2016-12-06	Branches:	0	898	0.0 %

/*	$OpenBSD: dhclient.c,v 1.379 2016/07/23 15:53:19 stsp Exp $	*/

/*
 * Copyright 2004 Henning Brauer <henning@openbsd.org>
 * Copyright (c) 1995, 1996, 1997, 1998, 1999
 * The Internet Software Consortium.    All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of The Internet Software Consortium nor the names
 *    of its contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * This software has been written for the Internet Software Consortium
 * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
 * Enterprises.  To learn more about the Internet Software Consortium,
 * see ``http://www.vix.com/isc''.  To learn more about Vixie
 * Enterprises, see ``http://www.vix.com''.
 *
 * This client was substantially modified and enhanced by Elliot Poger
 * for use on Linux while he was working on the MosquitoNet project at
 * Stanford.
 *
 * The current version owes much to Elliot's Linux enhancements, but
 * was substantially reorganized and partially rewritten by Ted Lemon
 * so as to use the same networking framework that the Internet Software
 * Consortium DHCP server uses.   Much system-specific configuration code
 * was moved into a shell script so that as support for more operating
 * systems is added, it will not be necessary to port and maintain
 * system-specific configuration code to these operating systems - instead,
 * the shell script can invoke the native tools to accomplish the same
 * purpose.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/uio.h>
#include <sys/queue.h>

#include <net/if.h>
#include <net/route.h>

#include <netinet/in.h>
#include <netinet/if_ether.h>

#include <arpa/inet.h>

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <ifaddrs.h>
#include <imsg.h>
#include <limits.h>
#include <paths.h>
#include <poll.h>
#include <pwd.h>
#include <resolv.h>
#include <signal.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>

#include "dhcp.h"
#include "dhcpd.h"
#include "privsep.h"

char *path_dhclient_conf = _PATH_DHCLIENT_CONF;
char *path_dhclient_db = NULL;

char path_option_db[PATH_MAX];

int log_perror = 1;
int nullfd = -1;
int no_daemon;
int unknown_ok = 1;
int routefd = -1;

volatile sig_atomic_t quit;

struct in_addr deleting;
struct in_addr adding;

const struct in_addr inaddr_any = { INADDR_ANY };
const struct in_addr inaddr_broadcast = { INADDR_BROADCAST };

struct interface_info *ifi;
struct client_state *client;
struct client_config *config;
struct imsgbuf *unpriv_ibuf;

void		 sighdlr(int);
int		 findproto(char *, int);
struct sockaddr	*get_ifa(char *, int);
void		 usage(void);
int		 res_hnok(const char *dn);
int		 res_hnok_list(const char *dn);
int		 addressinuse(struct in_addr, char *);

void		 fork_privchld(int, int);
void		 get_ifname(char *);
char		*resolv_conf_contents(struct option_data  *,
		     struct option_data *, struct option_data *);
void		 write_resolv_conf(u_int8_t *, size_t);
void		 write_option_db(u_int8_t *, size_t);

struct client_lease *apply_defaults(struct client_lease *);
struct client_lease *clone_lease(struct client_lease *);
void		 apply_ignore_list(char *);

void add_direct_route(struct in_addr, struct in_addr, struct in_addr);
void add_default_route(struct in_addr, struct in_addr);
void add_static_routes(struct option_data *, struct in_addr);
void add_classless_static_routes(struct option_data *, struct in_addr);

int compare_lease(struct client_lease *, struct client_lease *);
void set_lease_times(struct client_lease *);

void state_preboot(void);
void state_reboot(void);
void state_init(void);
void state_selecting(void);
void state_bound(void);
void state_panic(void);

void send_discover(void);
void send_request(void);
void send_decline(void);

void bind_lease(void);

void make_discover(struct client_lease *);
void make_request(struct client_lease *);
void make_decline(struct client_lease *);

void rewrite_client_leases(void);
void rewrite_option_db(struct client_lease *, struct client_lease *);
char *lease_as_string(char *, struct client_lease *);

struct client_lease *packet_to_lease(struct in_addr, struct option_data *);
void go_daemon(void);

#define	ROUNDUP(a) \
	    ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
#define	ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))

static FILE *leaseFile;

void
sighdlr(int sig)
{
	quit = sig;
}

int
findproto(char *cp, int n)
{
	struct sockaddr *sa;
	unsigned int i;

	if (n == 0)
		return -1;
	for (i = 1; i; i <<= 1) {
		if (i & n) {
			sa = (struct sockaddr *)cp;
			switch (i) {
			case RTA_IFA:
			case RTA_DST:
			case RTA_GATEWAY:
			case RTA_NETMASK:
				if (sa->sa_family == AF_INET)
					return AF_INET;
				if (sa->sa_family == AF_INET6)
					return AF_INET6;
				break;
			case RTA_IFP:
				break;
			}
			ADVANCE(cp, sa);
		}
	}
	return (-1);
}

struct sockaddr *
get_ifa(char *cp, int n)
{
	struct sockaddr *sa;
	unsigned int i;

	if (n == 0)
		return (NULL);
	for (i = 1; i; i <<= 1)
		if (i & n) {
			sa = (struct sockaddr *)cp;
			if (i == RTA_IFA)
				return (sa);
			ADVANCE(cp, sa);
		}

	return (NULL);
}

void
routehandler(void)
{
	char ntoabuf[INET_ADDRSTRLEN];
	struct in_addr a, b;
	ssize_t n;
	int linkstat, rslt;
	struct ether_addr hw;
	struct rt_msghdr *rtm;
	struct if_msghdr *ifm;
	struct ifa_msghdr *ifam;
	struct if_announcemsghdr *ifan;
	struct sockaddr *sa;
	char *errmsg, *rtmmsg;

	rtmmsg = calloc(1, 2048);
	if (rtmmsg == NULL)
		error("No memory for rtmmsg");

	do {
		n = read(routefd, rtmmsg, 2048);
	} while (n == -1 && errno == EINTR);

	rtm = (struct rt_msghdr *)rtmmsg;
	if (n < sizeof(rtm->rtm_msglen) || n < rtm->rtm_msglen ||
	    rtm->rtm_version != RTM_VERSION)
		goto done;

	switch (rtm->rtm_type) {
	case RTM_DESYNC:
		warning("route socket buffer overflow");
		break;
	case RTM_NEWADDR:
		ifam = (struct ifa_msghdr *)rtm;
		if (ifam->ifam_index != ifi->index)
			break;
		if (findproto((char *)ifam + ifam->ifam_hdrlen,
		    ifam->ifam_addrs) != AF_INET)
			break;
		sa = get_ifa((char *)ifam + ifam->ifam_hdrlen,
		    ifam->ifam_addrs);
		if (sa == NULL)
			goto done;

		memcpy(&a, &((struct sockaddr_in *)sa)->sin_addr, sizeof(a));
		if (a.s_addr == INADDR_ANY)
			break;

		/*
		 * If we are in the process of adding a new address, ignore
		 * messages generated by that process.
		 */
		if (a.s_addr == adding.s_addr) {
			adding.s_addr = INADDR_ANY;
			note("bound to %s -- renewal in %lld seconds.",
			    inet_ntoa(client->active->address),
			    (long long)(client->active->renewal -
			    time(NULL)));
			client->flags |= IS_RESPONSIBLE;
			go_daemon();
			break;
		}
		if ((client->flags & IS_RESPONSIBLE) == 0)
			/* We're not responsible yet! */
			break;
		if (adding.s_addr != INADDR_ANY) {
			strlcpy(ntoabuf, inet_ntoa(a), sizeof(ntoabuf));
			rslt = asprintf(&errmsg, "%s, not %s, added to %s",
			    ntoabuf, inet_ntoa(adding), ifi->name);
		} else
			rslt = asprintf(&errmsg, "%s added to %s",
			    inet_ntoa(a), ifi->name);
		goto die;
	case RTM_DELADDR:
		ifam = (struct ifa_msghdr *)rtm;
		if (ifam->ifam_index != ifi->index)
			break;
		if (findproto((char *)ifam + ifam->ifam_hdrlen,
		    ifam->ifam_addrs) != AF_INET)
			break;
		sa = get_ifa((char *)ifam + ifam->ifam_hdrlen,
		    ifam->ifam_addrs);
		if (sa == NULL)
			goto done;

		memcpy(&a, &((struct sockaddr_in *)sa)->sin_addr, sizeof(a));
		if (a.s_addr == INADDR_ANY)
			break;

		/*
		 * If we are in the process of deleting an address, ignore
		 * messages generated by that process.
		 */
		if (a.s_addr == deleting.s_addr) {
			deleting.s_addr = INADDR_ANY;
			break;
		}
		if ((client->flags & IS_RESPONSIBLE) == 0)
			/* We're not responsible yet! */
			break;
		if (adding.s_addr == INADDR_ANY && client->active &&
		    a.s_addr == client->active->address.s_addr) {
			/* Tell the priv process active_addr is gone. */
			warning("Active address (%s) deleted; exiting",
			    inet_ntoa(client->active->address));
			memset(&b, 0, sizeof(b));
			add_address(b, b);
			/* No need to write resolv.conf now. */
			client->flags &= ~IS_RESPONSIBLE;
			quit = INTERNALSIG;
			break;
		}
		if (deleting.s_addr != INADDR_ANY) {
			strlcpy(ntoabuf, inet_ntoa(a), sizeof(ntoabuf));
			rslt = asprintf(&errmsg, "%s, not %s, deleted from %s",
			    ntoabuf, inet_ntoa(deleting), ifi->name);
		} else
			rslt = asprintf(&errmsg, "%s deleted from %s",
			    inet_ntoa(a), ifi->name);
		goto die;
	case RTM_IFINFO:
		ifm = (struct if_msghdr *)rtm;
		if (ifm->ifm_index != ifi->index)
			break;
		if ((rtm->rtm_flags & RTF_UP) == 0) {
			rslt = asprintf(&errmsg, "%s down", ifi->name);
			goto die;
		}

		if (ifi->flags & IFI_VALID_LLADDR) {
			memcpy(&hw, &ifi->hw_address, sizeof(hw));
			get_hw_address();
			if (memcmp(&hw, &ifi->hw_address, sizeof(hw))) {
				warning("LLADDR changed; restarting");
				ifi->flags |= IFI_NEW_LLADDR;
				quit = SIGHUP;
				goto done;
			}
		}

		linkstat = interface_status(ifi->name);
		if (linkstat != ifi->linkstat) {
#ifdef DEBUG
			debug("link state %s -> %s",
			    ifi->linkstat ? "up" : "down",
			    linkstat ? "up" : "down");
#endif
			ifi->linkstat = linkstat;
			if (ifi->linkstat) {
				if (client->state == S_PREBOOT) {
					state_preboot();
					get_hw_address();
				} else {
					client->state = S_REBOOTING;
					state_reboot();
				}
			} else {
				/* Let monitoring programs see link loss. */
				if (strlen(path_option_db))
					write_option_db("", 0);
				/* No need to wait for anything but link. */
				cancel_timeout();
			}
		}
		break;
	case RTM_IFANNOUNCE:
		ifan = (struct if_announcemsghdr *)rtm;
		if (ifan->ifan_what == IFAN_DEPARTURE &&
		    ifan->ifan_index == ifi->index) {
			rslt = asprintf(&errmsg, "%s departured", ifi->name);
			goto die;
		}
		break;
	default:
		break;
	}

	/* Something has happened. Try to write out the resolv.conf. */
	if (client->active && client->active->resolv_conf &&
	    client->flags & IS_RESPONSIBLE)
		write_resolv_conf(client->active->resolv_conf,
		    strlen(client->active->resolv_conf));

done:
	free(rtmmsg);
	return;

die:
	if (rslt == -1)
		error("no memory for errmsg");
	error("%s; exiting", errmsg);
}

char **saved_argv;

int
main(int argc, char *argv[])
{
	struct stat sb;
	int	 ch, fd, socket_fd[2];
	extern char *__progname;
	struct passwd *pw;
	char *ignore_list = NULL;
	ssize_t tailn;
	int rtfilter, tailfd;

	saved_argv = argv;

	/* Initially, log errors to stderr as well as to syslogd. */
	openlog(__progname, LOG_PID | LOG_NDELAY, LOG_DAEMON);
#ifdef DEBUG
	setlogmask(LOG_UPTO(LOG_DEBUG));
#else
	setlogmask(LOG_UPTO(LOG_INFO));
#endif

	while ((ch = getopt(argc, argv, "c:di:l:L:qu")) != -1)
		switch (ch) {
		case 'c':
			path_dhclient_conf = optarg;
			break;
		case 'd':
			if (log_perror == 0)
				usage();
			no_daemon = log_perror = 1;
			break;
		case 'i':
			ignore_list = optarg;
			break;
		case 'l':
			path_dhclient_db = optarg;
			if (lstat(path_dhclient_db, &sb) != -1) {
				if (!S_ISREG(sb.st_mode))
					error("'%s' is not a regular file",
					    path_dhclient_db);
			}
			break;
		case 'L':
			strlcat(path_option_db, optarg, PATH_MAX);
			if (lstat(path_option_db, &sb) != -1) {
				if (!S_ISREG(sb.st_mode))
					error("'%s' is not a regular file",
					    path_option_db);
			}
			break;
		case 'q':
			if (no_daemon == 1)
				usage();
			no_daemon = log_perror = 0;
			break;
		case 'u':
			unknown_ok = 0;
			break;
		default:
			usage();
		}

	argc -= optind;
	argv += optind;

	if (argc != 1)
		usage();

	ifi = calloc(1, sizeof(struct interface_info));
	if (ifi == NULL)
		error("ifi calloc");
	get_ifname(argv[0]);
	ifi->index = if_nametoindex(ifi->name);
	if (ifi->index == 0)
		error("%s: no such interface", ifi->name);

	tzset();

	/* Put us into the correct rdomain */
	ifi->rdomain = get_rdomain(ifi->name);
	if (setrtable(ifi->rdomain) == -1)
		error("setting routing table to %u: '%s'", ifi->rdomain,
		    strerror(errno));

	if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC,
	    PF_UNSPEC, socket_fd) == -1)
		error("socketpair: %s", strerror(errno));

	fork_privchld(socket_fd[0], socket_fd[1]);

	close(socket_fd[0]);
	if ((unpriv_ibuf = malloc(sizeof(struct imsgbuf))) == NULL)
		error("no memory for unpriv_ibuf");
	imsg_init(unpriv_ibuf, socket_fd[1]);

	config = calloc(1, sizeof(struct client_config));
	if (config == NULL)
		error("config calloc");
	TAILQ_INIT(&config->reject_list);

	client = calloc(1, sizeof(struct client_state));
	if (client == NULL)
		error("client calloc");
	TAILQ_INIT(&client->leases);
	TAILQ_INIT(&client->offered_leases);

	read_client_conf();

	if ((nullfd = open(_PATH_DEVNULL, O_RDWR, 0)) == -1)
		error("cannot open %s: %s", _PATH_DEVNULL, strerror(errno));

	if ((pw = getpwnam("_dhcp")) == NULL)
		error("no such user: _dhcp");

	if (path_dhclient_db == NULL && asprintf(&path_dhclient_db, "%s.%s",
	    _PATH_DHCLIENT_DB, ifi->name) == -1)
		error("asprintf");

	/* 2nd stage (post fork) config setup. */
	if (ignore_list)
		apply_ignore_list(ignore_list);

	tailfd = open("/etc/resolv.conf.tail", O_RDONLY);
	if (tailfd == -1) {
		if (errno != ENOENT)
			error("Cannot open /etc/resolv.conf.tail: %s",
			    strerror(errno));
	} else if (fstat(tailfd, &sb) == -1) {
		error("Cannot stat /etc/resolv.conf.tail: %s",
		    strerror(errno));
	} else {
		if (sb.st_size > 0 && sb.st_size < SIZE_MAX) {
			config->resolv_tail = calloc(1, sb.st_size + 1);
			if (config->resolv_tail == NULL) {
				error("no memory for resolv.conf.tail "
				    "contents: %s", strerror(errno));
			}
			tailn = read(tailfd, config->resolv_tail, sb.st_size);
			if (tailn == -1)
				error("Couldn't read resolv.conf.tail: %s",
				    strerror(errno));
			else if (tailn == 0)
				error("Got no data from resolv.conf.tail");
			else if (tailn != sb.st_size)
				error("Short read of resolv.conf.tail");
		}
		close(tailfd);
	}

	if ((fd = open(path_dhclient_db,
	    O_RDONLY|O_EXLOCK|O_CREAT|O_NOFOLLOW, 0640)) == -1)
		error("can't open and lock %s: %s", path_dhclient_db,
		    strerror(errno));
	read_client_leases();
	if ((leaseFile = fopen(path_dhclient_db, "w")) == NULL)
		error("can't open %s: %s", path_dhclient_db, strerror(errno));
	rewrite_client_leases();
	close(fd);

	/*
	 * Do the initial status check and possible force up before creating
	 * the routing socket. If we bounce the interface down and up while
	 * the routing socket is listening, the RTM_IFINFO message with the
	 * RTF_UP flag reset will cause premature exit.
	 */
	ifi->linkstat = interface_status(ifi->name);
	if (ifi->linkstat == 0)
		interface_link_forceup(ifi->name);

	if ((routefd = socket(PF_ROUTE, SOCK_RAW, 0)) == -1)
		error("socket(PF_ROUTE, SOCK_RAW): %s", strerror(errno));

	rtfilter = ROUTE_FILTER(RTM_NEWADDR) | ROUTE_FILTER(RTM_DELADDR) |
	    ROUTE_FILTER(RTM_IFINFO) | ROUTE_FILTER(RTM_IFANNOUNCE);

	if (setsockopt(routefd, PF_ROUTE, ROUTE_MSGFILTER,
	    &rtfilter, sizeof(rtfilter)) == -1)
		error("setsockopt(ROUTE_MSGFILTER): %s", strerror(errno));
	if (setsockopt(routefd, AF_ROUTE, ROUTE_TABLEFILTER, &ifi->rdomain,
	    sizeof(ifi->rdomain)) == -1)
		error("setsockopt(ROUTE_TABLEFILTER): %s", strerror(errno));

	/* Register the interface. */
	if_register_receive();
	if_register_send();

	if (chroot(_PATH_VAREMPTY) == -1)
		error("chroot");
	if (chdir("/") == -1)
		error("chdir(\"/\")");

	if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1)
		error("setresgid");
	if (setgroups(1, &pw->pw_gid) == -1)
		error("setgroups");
	if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1)
		error("setresuid");

	endpwent();

	if (no_daemon) {
		if (pledge("stdio inet dns route rpath cpath wpath", NULL) == -1)
			error("pledge");
	} else {
		if (pledge("stdio inet dns route proc rpath cpath wpath", NULL) == -1)
			error("pledge");
	}

	setproctitle("%s", ifi->name);
	time(&client->startup_time);

	if (ifi->linkstat) {
		client->state = S_REBOOTING;
		state_reboot();
	} else {
		client->state = S_PREBOOT;
		state_preboot();
	}

	dispatch();

	/* not reached */
	return (0);
}

void
usage(void)
{
	extern char	*__progname;

	fprintf(stderr,
	    "usage: %s [-d | -q] [-u] [-c file] [-i options] [-L file] [-l file] "
	    "interface\n", __progname);
	exit(1);
}

void
state_preboot(void)
{
	static int preamble;
	time_t cur_time;
	int interval;

	time(&cur_time);

	interval = (int)(cur_time - client->startup_time);

	ifi->linkstat = interface_status(ifi->name);

	if (log_perror && interval > 3) {
		if (!preamble && !ifi->linkstat) {
			fprintf(stderr, "%s: no link ....", ifi->name);
			preamble = 1;
		}
		if (preamble) {
			if (ifi->linkstat)
				fprintf(stderr, " got link\n");
			else if (interval > config->link_timeout)
				fprintf(stderr, " sleeping\n");
			else
				fprintf(stderr, ".");
			fflush(stderr);
		}
	}

	if (ifi->linkstat) {
		client->state = S_REBOOTING;
		set_timeout_interval(1, state_reboot);
	} else {
		if (interval > config->link_timeout)
			go_daemon();
		client->state = S_PREBOOT;
		set_timeout_interval(1, state_preboot);
	}
}

/*
 * Called when the interface link becomes active.
 */
void
state_reboot(void)
{
	char ifname[IF_NAMESIZE];
	struct client_lease *lp;
	struct option_data *opt;
	time_t cur_time;

	cancel_timeout();
	deleting.s_addr = INADDR_ANY;
	adding.s_addr = INADDR_ANY;

	get_hw_address();
	opt = &config->send_options[DHO_DHCP_CLIENT_IDENTIFIER];
	/*
	 * Check both len && data so
	 *     send dhcp-client-identifier "";
	 * can be used to suppress sending the default client
	 * identifier.
	 */
	if (opt->len == 0 && opt->data == NULL) {
		/* Build default client identifier. */
		opt->data = calloc(1, ETHER_ADDR_LEN + 1);
		if (opt->data != NULL) {
			opt->data[0] = HTYPE_ETHER;
			memcpy(&opt->data[1], ifi->hw_address.ether_addr_octet,
			    ETHER_ADDR_LEN);
			opt->len = ETHER_ADDR_LEN + 1;
		}
	}

	time(&cur_time);
	if (client->active) {
		if (client->active->expiry <= cur_time)
			client->active = NULL;
		else if (addressinuse(client->active->address, ifname) &&
		    strncmp(ifname, ifi->name, IF_NAMESIZE) != 0)
			client->active = NULL;
	}

	/* Run through the list of leases and see if one can be used. */
	TAILQ_FOREACH(lp, &client->leases, next) {
		if (addressinuse(lp->address, ifname) &&
		    strncmp(ifname, ifi->name, IF_NAMESIZE) != 0)
			continue;
		if (client->active || lp->is_static)
			break;
		if (lp->expiry > cur_time) {
			client->active = lp;
			break;
		}
	}

	/* If we don't remember an active lease, go straight to INIT. */
	if (!client->active || client->active->is_bootp) {
		client->state = S_INIT;
		state_init();
		return;
	}

	client->xid = arc4random();
	make_request(client->active);

	client->destination.s_addr = INADDR_BROADCAST;
	client->first_sending = time(NULL);
	client->interval = 0;

	send_request();
}

/*
 * Called when a lease has completely expired and we've been unable to renew it.
 */
void
state_init(void)
{
	client->xid = arc4random();
	make_discover(client->active);

	client->destination.s_addr = INADDR_BROADCAST;
	client->state = S_SELECTING;
	client->first_sending = time(NULL);
	client->interval = 0;

	send_discover();
}

/*
 * Called when one or more DHCPOFFER packets have been received and a
 * configurable period of time has passed.
 */
void
state_selecting(void)
{
	struct client_lease *lease, *picked;

	cancel_timeout();

	/* Take the first valid DHCPOFFER. */
	TAILQ_FOREACH_SAFE(picked, &client->offered_leases, next, lease) {
		if (picked->is_invalid == 0) {
			TAILQ_REMOVE(&client->offered_leases, picked, next);
			break;
		}
	}
	/* DECLINE the rest of the offers. */
	while (!TAILQ_EMPTY(&client->offered_leases)) {
		lease = TAILQ_FIRST(&client->offered_leases);
		TAILQ_REMOVE(&client->offered_leases, lease, next);
		make_decline(lease);
		send_decline();
		free_client_lease(lease);
	}

	if (!picked) {
		state_panic();
		return;
	}

	/* If it was a BOOTREPLY, we can just take the lease right now. */
	if (!picked->options[DHO_DHCP_MESSAGE_TYPE].len) {
		struct option_data *option;

		client->new = picked;

		/*
		 * Set (unsigned 32 bit) options
		 *
		 * DHO_DHCP_LEASE_TIME (12000 seconds),
		 * DHO_RENEWAL_TIME (8000 seconds)
		 * DHO_REBINDING_TIME (10000 seconds)
		 *
		 * so bind_lease() can set the lease times. Note that the
		 * values must be big-endian.
		 */
		option = &client->new->options[DHO_DHCP_LEASE_TIME];
		option->data = malloc(4);
		if (option->data) {
			option->len = 4;
			memcpy(option->data, "\x00\x00\x2e\xe0", 4);
		}
		option = &client->new->options[DHO_DHCP_RENEWAL_TIME];
		option->data = malloc(4);
		if (option->data) {
			option->len = 4;
			memcpy(option->data, "\x00\x00\x1f\x40", 4);
		}
		option = &client->new->options[DHO_DHCP_REBINDING_TIME];
		option->data = malloc(4);
		if (option->data) {
			option->len = 4;
			memcpy(option->data, "\x00\x00\x27\x10", 4);
		}

		client->state = S_REQUESTING;
		bind_lease();

		return;
	}

	client->destination.s_addr = INADDR_BROADCAST;
	client->state = S_REQUESTING;
	client->first_sending = time(NULL);

	client->interval = 0;

	/*
	 * Make a DHCPREQUEST packet from the lease we picked. Keep
	 * the current xid, as all offers should have had the same
	 * one.
	 */
	make_request(picked);

	/* Toss the lease we picked - we'll get it back in a DHCPACK. */
	free_client_lease(picked);

	send_request();
}

void
dhcpack(struct in_addr client_addr, struct option_data *options, char *info)
{
	struct client_lease *lease;

	if (client->state != S_REBOOTING &&
	    client->state != S_REQUESTING &&
	    client->state != S_RENEWING &&
	    client->state != S_REBINDING) {
#ifdef DEBUG
		debug("Unexpected %s. State #%d", info, client->state);
#endif
		return;
	}

	note("%s", info);

	lease = packet_to_lease(client_addr, options);
	if (lease->is_invalid) {
		note("Unsatisfactory %s", info);
		make_decline(lease);
		send_decline();
		free_client_lease(lease);
		client->state = S_INIT;
		state_init();
		return;
	}

	client->new = lease;

	/* Stop resending DHCPREQUEST. */
	cancel_timeout();

	bind_lease();
}

void
bind_lease(void)
{
	struct in_addr gateway, mask;
	struct option_data *options, *opt;
	struct client_lease *lease, *pl;
	time_t cur_time;
	int seen;

	/*
	 * Clear out any old resolv_conf in case the lease has been here
	 * before (e.g. static lease).
	 */
	free(client->new->resolv_conf);
	client->new->resolv_conf = NULL;

	lease = apply_defaults(client->new);
	options = lease->options;

	set_lease_times(lease);

	client->new->expiry = lease->expiry;
	client->new->renewal = lease->renewal;
	client->new->rebind = lease->rebind;

	/*
	 * A duplicate lease once we are responsible & S_RENEWING means we don't
	 * need to change the interface, routing table or resolv.conf.
	 */
	if ((client->flags & IS_RESPONSIBLE) && client->state == S_RENEWING &&
	    compare_lease(client->active, client->new) == 0) {
		client->new->resolv_conf = client->active->resolv_conf;
		client->active->resolv_conf = NULL;
		client->active = client->new;
		client->new = NULL;
		note("bound to %s -- renewal in %lld seconds.",
		    inet_ntoa(client->active->address),
		    (long long)(client->active->renewal - time(NULL)));
		goto newlease;
	}

	client->new->resolv_conf = resolv_conf_contents(
	    &options[DHO_DOMAIN_NAME], &options[DHO_DOMAIN_NAME_SERVERS],
	    &options[DHO_DOMAIN_SEARCH]);

	/* Replace the old active lease with the new one. */
	client->active = client->new;
	client->new = NULL;

	/* Deleting the addresses also clears out arp entries. */
	delete_addresses();
	flush_routes();

	opt = &options[DHO_INTERFACE_MTU];
	if (opt->len == sizeof(u_int16_t)) {
		u_int16_t mtu;
		memcpy(&mtu, opt->data, sizeof(mtu));
		mtu = ntohs(mtu);
		/* "The minimum legal value for the MTU is 68." */
		if (mtu < 68)
			warning("mtu size %u < 68: ignored", mtu);
		else
			set_interface_mtu(mtu);
	}

	opt = &options[DHO_SUBNET_MASK];
	if (opt->len == sizeof(mask))
		mask.s_addr = ((struct in_addr *)opt->data)->s_addr;
	else
		mask.s_addr = INADDR_ANY;

        /*
	 * Add address and default route last, so we know when the binding
	 * is done by the RTM_NEWADDR message being received.
	 */
	add_address(client->active->address, mask);
	if (options[DHO_CLASSLESS_STATIC_ROUTES].len) {
		add_classless_static_routes(
		    &options[DHO_CLASSLESS_STATIC_ROUTES],
		    client->active->address);
	} else if (options[DHO_CLASSLESS_MS_STATIC_ROUTES].len) {
		add_classless_static_routes(
		    &options[DHO_CLASSLESS_MS_STATIC_ROUTES],
		    client->active->address);
	} else {
		opt = &options[DHO_ROUTERS];
		if (opt->len >= sizeof(gateway)) {
			/* XXX Only use FIRST router address for now. */
			gateway.s_addr = ((struct in_addr *)opt->data)->s_addr;

			/*
			 * To be compatible with ISC DHCP behavior on Linux, if
			 * we were given a /32 IP assignment, then add a /32
			 * direct route for the gateway to make it routable.
			 */
			if (mask.s_addr == INADDR_BROADCAST) {
				add_direct_route(gateway, mask,
				    client->active->address);
			}

			add_default_route(client->active->address, gateway);
		}
		if (options[DHO_STATIC_ROUTES].len)
			add_static_routes(&options[DHO_STATIC_ROUTES],
			    client->active->address);
	}

newlease:
	rewrite_option_db(client->active, lease);
	free_client_lease(lease);

	/*
	 * Remove previous dynamic lease(es) for this address, and any expired
	 * dynamic leases.
	 */
	seen = 0;
	time(&cur_time);
	TAILQ_FOREACH_SAFE(lease, &client->leases, next, pl) {
		if (lease->is_static)
			break;
		if (client->active == lease)
			seen = 1;
		else if (lease->expiry <= cur_time || lease->address.s_addr ==
		    client->active->address.s_addr) {
			TAILQ_REMOVE(&client->leases, lease, next);
			free_client_lease(lease);
		}
	}
	if (!client->active->is_static && !seen)
		TAILQ_INSERT_HEAD(&client->leases, client->active,  next);

	client->state = S_BOUND;

	/* Write out new leases file. */
	rewrite_client_leases();

	/* Set timeout to start the renewal process. */
	set_timeout(client->active->renewal, state_bound);
}

/*
 * Called when we've successfully bound to a particular lease, but the renewal
 * time on that lease has expired.  We are expected to unicast a DHCPREQUEST to
 * the server that gave us our original lease.
 */
void
state_bound(void)
{
	struct option_data *opt;
	struct in_addr *dest;

	client->xid = arc4random();
	make_request(client->active);

	dest = &client->destination;
	opt = &client->active->options[DHO_DHCP_SERVER_IDENTIFIER];

	if (opt->len == sizeof(*dest))
		dest->s_addr = ((struct in_addr *)opt->data)->s_addr;
	else
		dest->s_addr = INADDR_BROADCAST;

	client->first_sending = time(NULL);
	client->interval = 0;
	client->state = S_RENEWING;

	send_request();
}

void
dhcpoffer(struct in_addr client_addr, struct option_data *options, char *info)
{
	struct client_lease *lease, *lp;
	time_t stop_selecting;

	if (client->state != S_SELECTING) {
#ifdef DEBUG
		debug("Unexpected %s. State #%d.", info, client->state);
#endif
		return;
	}

	note("%s", info);

	/* If we've already seen this lease, don't record it again. */
	TAILQ_FOREACH(lp, &client->offered_leases, next) {
		if (!memcmp(&lp->address.s_addr, &client->packet.yiaddr,
		    sizeof(in_addr_t))) {
#ifdef DEBUG
			debug("Duplicate %s.", info);
#endif
			return;
		}
	}

	lease = packet_to_lease(client_addr, options);

	/*
	 * If this lease was acquired through a BOOTREPLY, record that
	 * fact.
	 */
	if (!options[DHO_DHCP_MESSAGE_TYPE].len)
		lease->is_bootp = 1;

	/* Figure out when we're supposed to stop selecting. */
	stop_selecting = client->first_sending + config->select_interval;

	if (TAILQ_EMPTY(&client->offered_leases)) {
		TAILQ_INSERT_HEAD(&client->offered_leases, lease, next);
	} else if (lease->address.s_addr == client->requested_address.s_addr) {
		/* The lease we expected - put it at the head of the list. */
		TAILQ_INSERT_HEAD(&client->offered_leases, lease, next);
	} else {
		/* Not the lease we expected - put it at the end of the list. */
		TAILQ_INSERT_TAIL(&client->offered_leases, lease, next);
	}

	if (stop_selecting <= time(NULL))
		state_selecting();
	else
		set_timeout(stop_selecting, state_selecting);
}

int
addressinuse(struct in_addr address, char *ifname)
{
	struct ifaddrs *ifap, *ifa;
	struct sockaddr_in *sin;
	int used = 0;

	if (getifaddrs(&ifap) != 0) {
		warning("addressinuse: getifaddrs: %s", strerror(errno));
		return (0);
	}

	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
		if (ifa->ifa_addr == NULL ||
		    ifa->ifa_addr->sa_family != AF_INET)
			continue;

		sin = (struct sockaddr_in *)ifa->ifa_addr;
		if (memcmp(&address, &sin->sin_addr, sizeof(address)) == 0) {
			strlcpy(ifname, ifa->ifa_name, IF_NAMESIZE);
			used = 1;
			if (strncmp(ifname, ifi->name, IF_NAMESIZE) != 0)
				break;
		}
	}

	freeifaddrs(ifap);
	return (used);
}

/*
 * Allocate a client_lease structure and initialize it from the
 * parameters in the specified packet.
 */
struct client_lease *
packet_to_lease(struct in_addr client_addr, struct option_data *options)
{
	char ifname[IF_NAMESIZE];
	struct client_lease *lease;
	char *pretty, *buf;
	int i, sz;

	lease = calloc(1, sizeof(struct client_lease));
	if (!lease) {
		warning("dhcpoffer: no memory to create lease.");
		return (NULL);
	}

	/* Copy the lease options. */
	for (i = 0; i < 256; i++) {
		if (options[i].len == 0)
			continue;
		if (!unknown_ok && strncmp("option-",
		    dhcp_options[i].name, 7) != 0) {
			warning("dhcpoffer: unknown option %d", i);
			lease->is_invalid = 1;
		}
		pretty = pretty_print_option(i, &options[i], 0);
		if (strlen(pretty) == 0)
			continue;
		switch (i) {
		case DHO_DOMAIN_SEARCH:
			/* Must decode the option into text to check names. */
			buf = calloc(1, DHCP_DOMAIN_SEARCH_LEN);
			if (buf == NULL)
				error("No memory to decode domain search");
			sz = pretty_print_domain_search(buf,
			    DHCP_DOMAIN_SEARCH_LEN,
			    options[i].data, options[i].len);
			if (strlen(buf) == 0)
				continue;
			if (sz == -1 || !res_hnok_list(buf))
				warning("Bogus data for option %s",
				    dhcp_options[i].name);
			free(buf);
			break;
		case DHO_DOMAIN_NAME:
			/*
			 * Allow deviant but historically blessed
			 * practice of supplying multiple domain names
			 * with DHO_DOMAIN_NAME. Thus allowing multiple
			 * entries in the resolv.conf 'search' statement.
			 */
			if (!res_hnok_list(pretty)) {
				warning("Bogus data for option %s",
				    dhcp_options[i].name);
				continue;
			}
			break;
		case DHO_HOST_NAME:
		case DHO_NIS_DOMAIN:
			if (!res_hnok(pretty)) {
				warning("Bogus data for option %s",
				    dhcp_options[i].name);
				continue;
			}
			break;
		default:
			break;
		}
		lease->options[i] = options[i];
		options[i].data = NULL;
		options[i].len = 0;
	}

	/*
	 * If this lease doesn't supply a required parameter, blow it off.
	 */
	for (i = 0; i < config->required_option_count; i++) {
		if (!lease->options[config->required_options[i]].len) {
			warning("Missing required parameter %s",
			    dhcp_options[i].name);
			lease->is_invalid = 1;
		}
	}

	/*
	 * If this lease is trying to sell us an address we are already
	 * using, blow it off.
	 */
	lease->address.s_addr = client->packet.yiaddr.s_addr;
	memset(ifname, 0, sizeof(ifname));
	if (addressinuse(lease->address, ifname) &&
	    strncmp(ifname, ifi->name, IF_NAMESIZE) != 0) {
		warning("%s already configured on %s",
		    inet_ntoa(lease->address), ifname);
		lease->is_invalid = 1;
	}

	/* Save the siaddr (a.k.a. next-server) info. */
	lease->next_server.s_addr = client->packet.siaddr.s_addr;

	/* If the server name was filled out, copy it. */
	if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
	    !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 2)) &&
	    client->packet.sname[0]) {
		lease->server_name = malloc(DHCP_SNAME_LEN + 1);
		if (!lease->server_name) {
			warning("dhcpoffer: no memory for server name.");
			lease->is_invalid = 1;
		}
		memcpy(lease->server_name, client->packet.sname,
		    DHCP_SNAME_LEN);
		lease->server_name[DHCP_SNAME_LEN] = '\0';
		if (!res_hnok(lease->server_name)) {
			warning("Bogus server name %s", lease->server_name);
			lease->is_invalid = 1;
		}
	}

	/* Ditto for the filename. */
	if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
	    !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 1)) &&
	    client->packet.file[0]) {
		/* Don't count on the NUL terminator. */
		lease->filename = malloc(DHCP_FILE_LEN + 1);
		if (!lease->filename) {
			warning("dhcpoffer: no memory for filename.");
			lease->is_invalid = 1;
		}
		memcpy(lease->filename, client->packet.file, DHCP_FILE_LEN);
		lease->filename[DHCP_FILE_LEN] = '\0';
	}
	return lease;
}

void
dhcpnak(struct in_addr client_addr, struct option_data *options, char *info)
{
	if (client->state != S_REBOOTING &&
	    client->state != S_REQUESTING &&
	    client->state != S_RENEWING &&
	    client->state != S_REBINDING) {
#ifdef DEBUG
		debug("Unexpected %s. State #%d", info, client->state);
#endif
		return;
	}

	if (!client->active) {
#ifdef DEBUG
		debug("Unexpected %s. No active lease.", info);
#endif
		return;
	}

	note("%s", info);

	/* XXX Do we really want to remove a NAK'd lease from the database? */
	if (!client->active->is_static) {
		TAILQ_REMOVE(&client->leases, client->active, next);
		free_client_lease(client->active);
	}

	client->active = NULL;

	/* Stop sending DHCPREQUEST packets. */
	cancel_timeout();

	client->state = S_INIT;
	state_init();
}

/*
 * Send out a DHCPDISCOVER packet, and set a timeout to send out another
 * one after the right interval has expired.  If we don't get an offer by
 * the time we reach the panic interval, call the panic function.
 */
void
send_discover(void)
{
	time_t cur_time;
	ssize_t rslt;
	int interval;

	time(&cur_time);

	/* Figure out how long it's been since we started transmitting. */
	interval = cur_time - client->first_sending;

	if (interval > config->timeout) {
		state_panic();
		return;
	}

	/*
	 * If we're supposed to increase the interval, do so.  If it's
	 * currently zero (i.e., we haven't sent any packets yet), set
	 * it to initial_interval; otherwise, add to it a random
	 * number between zero and two times itself.  On average, this
	 * means that it will double with every transmission.
	 */
	if (!client->interval)
		client->interval = config->initial_interval;
	else {
		client->interval += arc4random_uniform(2 * client->interval);
	}

	/* Don't backoff past cutoff. */
	if (client->interval > config->backoff_cutoff)
		client->interval = (config->backoff_cutoff / 2) +
		    arc4random_uniform(config->backoff_cutoff);

	/* If the backoff would take us to the panic timeout, just use that
	   as the interval. */
	if (cur_time + client->interval >
	    client->first_sending + config->timeout)
		client->interval = (client->first_sending +
			 config->timeout) - cur_time + 1;

	/* Record the number of seconds since we started sending. */
	if (interval < UINT16_MAX)
		client->bootrequest_packet.secs = htons(interval);
	else
		client->bootrequest_packet.secs = htons(UINT16_MAX);
	client->secs = client->bootrequest_packet.secs;

	note("DHCPDISCOVER on %s - interval %lld", ifi->name,
	    (long long)client->interval);

	rslt = send_packet(inaddr_any, inaddr_broadcast);
	if (rslt == -1 && errno == EAFNOSUPPORT) {
		warning("dhclient cannot be used on %s", ifi->name);
		quit = INTERNALSIG;
	} else
		set_timeout_interval(client->interval, send_discover);
}

/*
 * Called if we haven't received any offers in a preset amount of time. When
 * this happens, we try to use existing leases that haven't yet expired.
 */
void
state_panic(void)
{
	char ifname[IF_NAMESIZE];
	struct client_lease *lp;
	time_t cur_time;

	time(&cur_time);
	note("No acceptable DHCPOFFERS received.");

	/* Run through the list of leases and see if one can be used. */
	time(&cur_time);
	TAILQ_FOREACH(lp, &client->leases, next) {
		if (addressinuse(lp->address, ifname) &&
		    strncmp(ifname, ifi->name, IF_NAMESIZE) != 0)
			continue;
		if (lp->is_static) {
			set_lease_times(lp);
			note("Trying static lease %s", inet_ntoa(lp->address));
		} else if (lp->expiry <= cur_time) {
			continue;
		} else
			note("Trying recorded lease %s",
			    inet_ntoa(lp->address));

		client->new = lp;
		client->state = S_REQUESTING;
		bind_lease();

		return;
	}

	/*
	 * No leases were available, or what was available didn't work
	 */
	note("No working leases in persistent database - sleeping.");
	client->state = S_INIT;
	set_timeout_interval(config->retry_interval, state_init);
	go_daemon();
}

void
send_request(void)
{
	struct sockaddr_in destination;
	struct in_addr from;
	time_t cur_time;
	int interval;

	time(&cur_time);

	/* Figure out how long it's been since we started transmitting. */
	interval = (int)(cur_time - client->first_sending);

	/*
	 * If we're in the INIT-REBOOT or REQUESTING state and we're
	 * past the reboot timeout, go to INIT and see if we can
	 * DISCOVER an address.
	 *
	 * XXX In the INIT-REBOOT state, if we don't get an ACK, it
	 * means either that we're on a network with no DHCP server,
	 * or that our server is down.  In the latter case, assuming
	 * that there is a backup DHCP server, DHCPDISCOVER will get
	 * us a new address, but we could also have successfully
	 * reused our old address.  In the former case, we're hosed
	 * anyway.  This is not a win-prone situation.
	 */
	if ((client->state == S_REBOOTING ||
	    client->state == S_REQUESTING) &&
	    interval > config->reboot_timeout) {
		client->state = S_INIT;
		cancel_timeout();
		state_init();
		return;
	}

	/*
	 * If the lease has expired, relinquish the address and go back to the
	 * INIT state.
	 */
	if (client->state != S_REQUESTING &&
	    cur_time > client->active->expiry) {
		if (client->active)
			delete_address(client->active->address);
		client->state = S_INIT;
		state_init();
		return;
	}

	/* Do the exponential backoff. */
	if (!client->interval)
		client->interval = config->initial_interval;
	else
		client->interval += arc4random_uniform(2 * client->interval);

	/* Don't backoff past cutoff. */
	if (client->interval > config->backoff_cutoff)
		client->interval = (config->backoff_cutoff / 2) +
		    arc4random_uniform(client->interval);

	/*
	 * If the backoff would take us to the expiry time, just set the
	 * timeout to the expiry time.
	 */
	if (client->state != S_REQUESTING && cur_time + client->interval >
	    client->active->expiry)
		client->interval = client->active->expiry - cur_time + 1;

	/*
	 * If the reboot timeout has expired, or the lease rebind time has
	 * elapsed, or if we're not yet bound, broadcast the DHCPREQUEST rather
	 * than unicasting.
	 */
	memset(&destination, 0, sizeof(destination));
	if (client->state == S_REQUESTING ||
	    client->state == S_REBOOTING ||
	    cur_time > client->active->rebind ||
	    interval > config->reboot_timeout)
		destination.sin_addr.s_addr = INADDR_BROADCAST;
	else
		destination.sin_addr.s_addr = client->destination.s_addr;

	if (client->state != S_REQUESTING)
		from.s_addr = client->active->address.s_addr;
	else
		from.s_addr = INADDR_ANY;

	/* Record the number of seconds since we started sending. */
	if (client->state == S_REQUESTING)
		client->bootrequest_packet.secs = client->secs;
	else {
		if (interval < UINT16_MAX)
			client->bootrequest_packet.secs = htons(interval);
		else
			client->bootrequest_packet.secs = htons(UINT16_MAX);
	}

	note("DHCPREQUEST on %s to %s", ifi->name,
	    inet_ntoa(destination.sin_addr));

	send_packet(from, destination.sin_addr);

	set_timeout_interval(client->interval, send_request);
}

void
send_decline(void)
{
	note("DHCPDECLINE on %s", ifi->name);

	send_packet(inaddr_any, inaddr_broadcast);
}

void
make_discover(struct client_lease *lease)
{
	struct option_data options[256];
	struct dhcp_packet *packet = &client->bootrequest_packet;
	unsigned char discover = DHCPDISCOVER;
	int i;

	memset(options, 0, sizeof(options));
	memset(packet, 0, sizeof(*packet));

	/* Set DHCP_MESSAGE_TYPE to DHCPDISCOVER */
	i = DHO_DHCP_MESSAGE_TYPE;
	options[i].data = &discover;
	options[i].len = sizeof(discover);

	/* Request the options we want */
	i  = DHO_DHCP_PARAMETER_REQUEST_LIST;
	options[i].data = config->requested_options;
	options[i].len = config->requested_option_count;

	/* If we had an address, try to get it again. */
	if (lease) {
		client->requested_address = lease->address;
		i = DHO_DHCP_REQUESTED_ADDRESS;
		options[i].data = (char *)&lease->address;
		options[i].len = sizeof(lease->address);
	} else
		client->requested_address.s_addr = INADDR_ANY;

	/* Send any options requested in the config file. */
	for (i = 0; i < 256; i++)
		if (!options[i].data &&
		    config->send_options[i].data) {
			options[i].data = config->send_options[i].data;
			options[i].len = config->send_options[i].len;
		}

	/* Set up the option buffer to fit in a minimal UDP packet. */
	i = cons_options(options);
	if (i == -1 || packet->options[i] != DHO_END)
		error("options do not fit in DHCPDISCOVER packet.");
	client->bootrequest_packet_length = DHCP_FIXED_NON_UDP+i+1;
	if (client->bootrequest_packet_length < BOOTP_MIN_LEN)
		client->bootrequest_packet_length = BOOTP_MIN_LEN;

	packet->op = BOOTREQUEST;
	packet->htype = HTYPE_ETHER ;
	packet->hlen = ETHER_ADDR_LEN;
	packet->hops = 0;
	packet->xid = client->xid;
	packet->secs = 0; /* filled in by send_discover. */
	packet->flags = 0;

	packet->ciaddr.s_addr = INADDR_ANY;
	packet->yiaddr.s_addr = INADDR_ANY;
	packet->siaddr.s_addr = INADDR_ANY;
	packet->giaddr.s_addr = INADDR_ANY;

	memcpy(&packet->chaddr, ifi->hw_address.ether_addr_octet,
	    ETHER_ADDR_LEN);
}

void
make_request(struct client_lease * lease)
{
	struct option_data options[256];
	struct dhcp_packet *packet = &client->bootrequest_packet;
	unsigned char request = DHCPREQUEST;
	int i;

	memset(options, 0, sizeof(options));
	memset(packet, 0, sizeof(*packet));

	/* Set DHCP_MESSAGE_TYPE to DHCPREQUEST */
	i = DHO_DHCP_MESSAGE_TYPE;
	options[i].data = &request;
	options[i].len = sizeof(request);

	/* Request the options we want */
	i = DHO_DHCP_PARAMETER_REQUEST_LIST;
	options[i].data = config->requested_options;
	options[i].len = config->requested_option_count;

	/*
	 * If we are requesting an address that hasn't yet been assigned
	 * to us, use the DHCP Requested Address option.
	 */
	if (client->state == S_REQUESTING) {
		/* Send back the server identifier. */
		i = DHO_DHCP_SERVER_IDENTIFIER;
		options[i].data = lease->options[i].data;
		options[i].len = lease->options[i].len;
	}
	if (client->state == S_REQUESTING ||
	    client->state == S_REBOOTING) {
		client->requested_address = lease->address;
		i = DHO_DHCP_REQUESTED_ADDRESS;
		options[i].data = (char *)&lease->address.s_addr;
		options[i].len = sizeof(in_addr_t);
	}

	/* Send any options requested in the config file. */
	for (i = 0; i < 256; i++)
		if (!options[i].data && config->send_options[i].data) {
			options[i].data = config->send_options[i].data;
			options[i].len = config->send_options[i].len;
		}

	/* Set up the option buffer to fit in a minimal UDP packet. */
	i = cons_options(options);
	if (i == -1 || packet->options[i] != DHO_END)
		error("options do not fit in DHCPREQUEST packet.");
	client->bootrequest_packet_length = DHCP_FIXED_NON_UDP+i+1;
	if (client->bootrequest_packet_length < BOOTP_MIN_LEN)
		client->bootrequest_packet_length = BOOTP_MIN_LEN;

	packet->op = BOOTREQUEST;
	packet->htype = HTYPE_ETHER ;
	packet->hlen = ETHER_ADDR_LEN;
	packet->hops = 0;
	packet->xid = client->xid;
	packet->secs = 0; /* Filled in by send_request. */
	packet->flags = 0;

	/*
	 * If we own the address we're requesting, put it in ciaddr. Otherwise
	 * set ciaddr to zero.
	 */
	if (client->state == S_BOUND ||
	    client->state == S_RENEWING ||
	    client->state == S_REBINDING)
		packet->ciaddr.s_addr = lease->address.s_addr;
	else
		packet->ciaddr.s_addr = INADDR_ANY;

	packet->yiaddr.s_addr = INADDR_ANY;
	packet->siaddr.s_addr = INADDR_ANY;
	packet->giaddr.s_addr = INADDR_ANY;

	memcpy(&packet->chaddr, ifi->hw_address.ether_addr_octet,
	    ETHER_ADDR_LEN);
}

void
make_decline(struct client_lease *lease)
{
	struct option_data options[256];
	struct dhcp_packet *packet = &client->bootrequest_packet;
	unsigned char decline = DHCPDECLINE;
	int i;

	memset(options, 0, sizeof(options));
	memset(packet, 0, sizeof(*packet));

	/* Set DHCP_MESSAGE_TYPE to DHCPDECLINE */
	i = DHO_DHCP_MESSAGE_TYPE;
	options[i].data = &decline;
	options[i].len = sizeof(decline);

	/* Send back the server identifier. */
	i = DHO_DHCP_SERVER_IDENTIFIER;
	options[i].data = lease->options[i].data;
	options[i].len = lease->options[i].len;

	/* Send back the address we're declining. */
	i = DHO_DHCP_REQUESTED_ADDRESS;
	options[i].data = (char *)&lease->address.s_addr;
	options[i].len = sizeof(in_addr_t);

	/* Send the uid if the user supplied one. */
	i = DHO_DHCP_CLIENT_IDENTIFIER;
	if (config->send_options[i].len) {
		options[i].data = config->send_options[i].data;
		options[i].len = config->send_options[i].len;
	}

	/* Set up the option buffer to fit in a minimal UDP packet. */
	i = cons_options(options);
	if (i == -1 || packet->options[i] != DHO_END)
		error("options do not fit in DHCPDECLINE packet.");
	client->bootrequest_packet_length = DHCP_FIXED_NON_UDP+i+1;
	if (client->bootrequest_packet_length < BOOTP_MIN_LEN)
		client->bootrequest_packet_length = BOOTP_MIN_LEN;

	packet->op = BOOTREQUEST;
	packet->htype = HTYPE_ETHER ;
	packet->hlen = ETHER_ADDR_LEN;
	packet->hops = 0;
	packet->xid = client->xid;
	packet->secs = 0; /* Filled in by send_request. */
	packet->flags = 0;

	/* ciaddr must always be zero. */
	packet->ciaddr.s_addr = INADDR_ANY;
	packet->yiaddr.s_addr = INADDR_ANY;
	packet->siaddr.s_addr = INADDR_ANY;
	packet->giaddr.s_addr = INADDR_ANY;

	memcpy(&packet->chaddr, ifi->hw_address.ether_addr_octet,
	    ETHER_ADDR_LEN);
}

void
free_client_lease(struct client_lease *lease)
{
	int i;

	/* Static leases are forever. */
	if (lease->is_static)
		return;

	free(lease->server_name);
	free(lease->filename);
	free(lease->resolv_conf);
	for (i = 0; i < 256; i++)
		free(lease->options[i].data);

	free(lease);
}

void
rewrite_client_leases(void)
{
	struct client_lease *lp;
	char *leasestr;
	time_t cur_time;

	if (!leaseFile)	/* XXX */
		error("lease file not open");

	fflush(leaseFile);
	rewind(leaseFile);

	/*
	 * The leases file is kept in chronological order, with the
	 * most recently bound lease last. When the file was read
	 * leases that were not expired were added to the head of the
	 * TAILQ client->leases as they were read. Therefore write out
	 * the leases in client->leases in reverse order to recreate
	 * the chonological order required.
	 */
	time(&cur_time);
	TAILQ_FOREACH_REVERSE(lp, &client->leases, _leases, next) {
		/* Don't write out static leases from dhclient.conf. */
		if (lp->is_static)
			continue;
		if (lp->expiry <= cur_time)
			continue;
		leasestr = lease_as_string("lease", lp);
		if (leasestr)
			fprintf(leaseFile, "%s", leasestr);
		else
			warning("cannot make lease into string");
	}

	fflush(leaseFile);
	ftruncate(fileno(leaseFile), ftello(leaseFile));
	fsync(fileno(leaseFile));
}

void
rewrite_option_db(struct client_lease *offered, struct client_lease *effective)
{
	u_int8_t db[8192];
	char *leasestr;
	size_t n;

	if (strlen(path_option_db) == 0)
		return;

	memset(db, 0, sizeof(db));

	leasestr = lease_as_string("offered", offered);
	if (leasestr) {
		n = strlcat(db, leasestr, sizeof(db));
		if (n >= sizeof(db))
			warning("cannot fit offered lease into option db");
	} else
		warning("cannot make offered lease into string");

	leasestr = lease_as_string("effective", effective);
	if (leasestr) {
		n = strlcat(db, leasestr, sizeof(db));
		if (n >= sizeof(db))
			warning("cannot fit effective lease into option db");
	} else
		warning("cannot make effective lease into string");

	write_option_db(db, strlen(db));
}

char *
lease_as_string(char *type, struct client_lease *lease)
{
	static char leasestr[8192];
	struct option_data *opt;
	char *p;
	size_t sz, rsltsz;
	int i, rslt;

	sz = sizeof(leasestr);
	p = leasestr;
	memset(p, 0, sz);

	rslt = snprintf(p, sz, "%s {\n"
	    "%s  interface \"%s\";\n  fixed-address %s;\n",
	    type, (lease->is_bootp) ? "  bootp;\n" : "", ifi->name,
	    inet_ntoa(lease->address));
	if (rslt == -1 || rslt >= sz)
		return (NULL);
	p += rslt;
	sz -= rslt;

	rslt = snprintf(p, sz, "  next-server %s;\n",
	    inet_ntoa(lease->next_server));
	if (rslt == -1 || rslt >= sz)
		return (NULL);
	p += rslt;
	sz -= rslt;

	if (lease->filename) {
		rslt = snprintf(p, sz, "  filename ");
		if (rslt == -1 || rslt >= sz)
			return (NULL);
		p += rslt;
		sz -= rslt;
		rslt = pretty_print_string(p, sz, lease->filename,
		    strlen(lease->filename), 1);
		if (rslt == -1 || rslt >= sz)
			return (NULL);
		p += rslt;
		sz -= rslt;
		rslt = snprintf(p, sz, ";\n");
		if (rslt == -1 || rslt >= sz)
			return (NULL);
		p += rslt;
		sz -= rslt;
	}
	if (lease->server_name) {
		rslt = snprintf(p, sz, "  server-name ");
		if (rslt == -1 || rslt >= sz)
			return (NULL);
		p += rslt;
		sz -= rslt;
		rslt = pretty_print_string(p, sz, lease->server_name,
		    strlen(lease->server_name), 1);
		if (rslt == -1 || rslt >= sz)
			return (NULL);
		p += rslt;
		sz -= rslt;
		rslt = snprintf(p, sz, ";\n");
		if (rslt == -1 || rslt >= sz)
			return (NULL);
		p += rslt;
		sz -= rslt;
	}

	for (i = 0; i < 256; i++) {
		if (i == DHO_DHCP_CLIENT_IDENTIFIER) {
			/* Ignore any CLIENT_IDENTIFIER from server. */
			opt = &config->send_options[i];
		} else if (lease->options[i].len)
			opt = &lease->options[i];
		else
			continue;

		rslt = snprintf(p, sz, "  option %s %s;\n",
		    dhcp_options[i].name, pretty_print_option(i, opt,  1));
		if (rslt == -1 || rslt >= sz)
			return (NULL);
		p += rslt;
		sz -= rslt;
	}

	rsltsz = strftime(p, sz, "  renew " DB_TIMEFMT ";\n",
	    gmtime(&lease->renewal));
	if (rsltsz == 0)
		return (NULL);
	p += rsltsz;
	sz -= rsltsz;
	rsltsz = strftime(p, sz, "  rebind " DB_TIMEFMT ";\n",
	    gmtime(&lease->rebind));
	if (rsltsz == 0)
		return (NULL);
	p += rsltsz;
	sz -= rsltsz;
	rsltsz = strftime(p, sz, "  expire " DB_TIMEFMT ";\n",
	    gmtime(&lease->expiry));
	if (rsltsz == 0)
		return (NULL);
	p += rsltsz;
	sz -= rsltsz;
	rslt = snprintf(p, sz, "}\n");
	if (rslt == -1 || rslt >= sz)
		return (NULL);

	return (leasestr);
}

void
go_daemon(void)
{
	static int state = 0;

	if (no_daemon || state)
		return;

	state = 1;

	/* Stop logging to stderr. */
	log_perror = 0;

	if (daemon(1, 0) == -1)
		error("daemon");

	/* we are chrooted, daemon(3) fails to open /dev/null */
	if (nullfd != -1) {
		dup2(nullfd, STDIN_FILENO);
		dup2(nullfd, STDOUT_FILENO);
		dup2(nullfd, STDERR_FILENO);
		close(nullfd);
		nullfd = -1;
	}

	/* Catch stuff that might be trying to terminate the program. */
	signal(SIGHUP, sighdlr);
	signal(SIGINT, sighdlr);
	signal(SIGTERM, sighdlr);
	signal(SIGUSR1, sighdlr);
	signal(SIGUSR2, sighdlr);

	signal(SIGPIPE, SIG_IGN);
}

int
res_hnok(const char *name)
{
	const char *dn = name;
	int pch = '.', ch = (unsigned char)*dn++;
	int warn = 0;

	while (ch != '\0') {
		int nch = (unsigned char)*dn++;

		if (ch == '.') {
			;
		} else if (pch == '.' || nch == '.' || nch == '\0') {
			if (!isalnum(ch))
				return (0);
		} else if (!isalnum(ch) && ch != '-' && ch != '_')
				return (0);
		else if (ch == '_' && warn == 0) {
			warning("warning: hostname %s contains an "
			    "underscore which violates RFC 952", name);
			warn++;
		}
		pch = ch, ch = nch;
	}
	return (1);
}

/*
 * resolv_conf(5) says a max of DHCP_DOMAIN_SEARCH_CNT domains and total
 * length of DHCP_DOMAIN_SEARCH_LEN bytes are acceptable for the 'search'
 * statement.
 */
int
res_hnok_list(const char *names)
{
	char *dupnames, *hn, *inputstring;
	int count;

	if (strlen(names) >= DHCP_DOMAIN_SEARCH_LEN)
		return (0);

	dupnames = inputstring = strdup(names);
	if (inputstring == NULL)
		error("Cannot copy domain name list");

	count = 0;
	while ((hn = strsep(&inputstring, " \t")) != NULL) {
		if (strlen(hn) == 0)
			continue;
		if (res_hnok(hn) == 0)
			break;
		count++;
		if (count > DHCP_DOMAIN_SEARCH_CNT)
			break;
	}

	free(dupnames);

	return (count > 0 && count < 7 && hn == NULL);
}

void
fork_privchld(int fd, int fd2)
{
	struct imsg_hup imsg;
	struct pollfd pfd[1];
	struct imsgbuf *priv_ibuf;
	ssize_t n;
	int nfds, rslt;

	switch (fork()) {
	case -1:
		error("cannot fork");
		break;
	case 0:
		break;
	default:
		return;
	}

	if (chdir("/") == -1)
		error("chdir(\"/\")");

	setproctitle("%s [priv]", ifi->name);

	go_daemon();

	close(fd2);

	if ((priv_ibuf = malloc(sizeof(struct imsgbuf))) == NULL)
		error("no memory for priv_ibuf");

	imsg_init(priv_ibuf, fd);

	while (quit == 0) {
		pfd[0].fd = priv_ibuf->fd;
		pfd[0].events = POLLIN;
		if ((nfds = poll(pfd, 1, INFTIM)) == -1) {
			if (errno != EINTR) {
				warning("poll error: %s", strerror(errno));
				quit = INTERNALSIG;
			}
			continue;
		}

		if (nfds == 0 || !(pfd[0].revents & POLLIN))
			continue;

		if ((n = imsg_read(priv_ibuf)) == -1 && errno != EAGAIN) {
			warning("imsg_read(priv_ibuf): %s", strerror(errno));
			quit = INTERNALSIG;
			continue;
		}

		if (n == 0) {
			/* Connection closed -- other end should log message. */
			quit = INTERNALSIG;
			continue;
		}

		dispatch_imsg(priv_ibuf);
	}

	imsg_clear(priv_ibuf);
	close(fd);

	if (strlen(path_option_db)) {
		/* Truncate the file so monitoring process see exit. */
		rslt = truncate(path_option_db, 0);
		if (rslt == -1)
			warning("Unable to truncate '%s': %s", path_option_db,
			    strerror(errno));
	}

	/*
	 * SIGTERM is used by system at shut down. Be nice and don't cleanup
	 * routes, possibly preventing NFS from properly shutting down.
	 */
	if (quit != SIGTERM) {
		memset(&imsg, 0, sizeof(imsg));
		imsg.addr = active_addr;
		priv_cleanup(&imsg);
	}

	if (quit == SIGHUP) {
		if (!(ifi->flags & IFI_HUP) &&
		   (!(ifi->flags & IFI_NEW_LLADDR)))
			warning("%s; restarting.", strsignal(quit));
		signal(SIGHUP, SIG_IGN); /* will be restored after exec */
		execvp(saved_argv[0], saved_argv);
		error("RESTART FAILED: '%s': %s", saved_argv[0],
		    strerror(errno));
	}

	if (quit != INTERNALSIG)
		warning("%s; exiting", strsignal(quit));

	exit(1);
}

void
get_ifname(char *arg)
{
	struct ifgroupreq ifgr;
	struct ifg_req *ifg;
	int s, len;

	if (strcmp(arg, "egress") == 0) {
		s = socket(AF_INET, SOCK_DGRAM, 0);
		if (s == -1)
			error("socket error");
		memset(&ifgr, 0, sizeof(ifgr));
		strlcpy(ifgr.ifgr_name, "egress", sizeof(ifgr.ifgr_name));
		if (ioctl(s, SIOCGIFGMEMB, (caddr_t)&ifgr) == -1) {
			if (errno == ENOENT)
				error("no interface in group egress found");
			error("ioctl SIOCGIFGMEMB: %s", strerror(errno));
		}
		len = ifgr.ifgr_len;
		if ((ifgr.ifgr_groups = calloc(1, len)) == NULL)
			error("get_ifname");
		if (ioctl(s, SIOCGIFGMEMB, (caddr_t)&ifgr) == -1)
			error("ioctl SIOCGIFGMEMB: %s", strerror(errno));

		arg = NULL;
		for (ifg = ifgr.ifgr_groups;
		    ifg && len >= sizeof(struct ifg_req); ifg++) {
			len -= sizeof(struct ifg_req);
			if (arg)
				error("too many interfaces in group egress");
			arg = ifg->ifgrq_member;
		}

		if (strlcpy(ifi->name, arg, IFNAMSIZ) >= IFNAMSIZ)
			error("Interface name too long: %s", strerror(errno));

		free(ifgr.ifgr_groups);
		close(s);
	} else if (strlcpy(ifi->name, arg, IFNAMSIZ) >= IFNAMSIZ)
		error("Interface name too long");
}

/*
 * Update resolv.conf.
 */
char *
resolv_conf_contents(struct option_data  *domainname,
    struct option_data *nameservers, struct option_data *domainsearch)
{
	char *dn, *ns, *nss[MAXNS], *contents, *courtesy, *p, *buf;
	size_t len;
	int i, rslt, sz;

	memset(nss, 0, sizeof(nss));

	if (domainsearch->len) {
		buf = calloc(1, DHCP_DOMAIN_SEARCH_LEN);
		if (buf == NULL)
			error("No memory to decode domain search");
		sz = pretty_print_domain_search(buf, DHCP_DOMAIN_SEARCH_LEN,
		    domainsearch->data, domainsearch->len);
		if (sz == -1)
			dn = strdup("");
		else {
			rslt = asprintf(&dn, "search %s\n", buf);
			if (rslt == -1)
				dn = NULL;
		}
		free(buf);
	} else if (domainname->len) {
		rslt = asprintf(&dn, "search %s\n",
		    pretty_print_option(DHO_DOMAIN_NAME, domainname, 0));
		if (rslt == -1)
			dn = NULL;
	} else
		dn = strdup("");
	if (dn == NULL)
		error("no memory for domainname");

	if (nameservers->len) {
		ns = pretty_print_option(DHO_DOMAIN_NAME_SERVERS, nameservers,
		    0);
		for (i = 0; i < MAXNS; i++) {
			p = strsep(&ns, " ");
			if (p == NULL)
				break;
			if (*p == '\0')
				continue;
			rslt = asprintf(&nss[i], "nameserver %s\n", p);
			if (rslt == -1)
				error("no memory for nameserver");
		}
	}

	len = strlen(dn);
	for (i = 0; i < MAXNS; i++)
		if (nss[i])
			len += strlen(nss[i]);

	if (len > 0 && config->resolv_tail)
		len += strlen(config->resolv_tail);

	if (len == 0) {
		free(dn);
		return (NULL);
	}

	rslt = asprintf(&courtesy, "# Generated by %s dhclient\n", ifi->name);
	if (rslt == -1)
		error("no memory for courtesy line");
	len += strlen(courtesy);

	len++; /* Need room for terminating NUL. */
	contents = calloc(1, len);
	if (contents == NULL)
		error("no memory for resolv.conf contents");

	strlcat(contents, courtesy, len);
	free(courtesy);

	strlcat(contents, dn, len);
	free(dn);

	for (i = 0; i < MAXNS; i++) {
		if (nss[i]) {
			strlcat(contents, nss[i], len);
			free(nss[i]);
		}
	}

	if (config->resolv_tail)
		strlcat(contents, config->resolv_tail, len);

	return (contents);
}

struct client_lease *
apply_defaults(struct client_lease *lease)
{
	struct client_lease *newlease;
	int i, j;

	newlease = clone_lease(lease);
	if (newlease == NULL)
		error("Unable to clone lease");

	if (config->filename) {
		free(newlease->filename);
		newlease->filename = strdup(config->filename);
	}
	if (config->server_name) {
		free(newlease->server_name);
		newlease->server_name = strdup(config->server_name);
	}
	if (config->address.s_addr != INADDR_ANY)
		newlease->address.s_addr = config->address.s_addr;
	if (config->next_server.s_addr != INADDR_ANY)
		newlease->next_server.s_addr = config->next_server.s_addr;

	for (i = 0; i < 256; i++) {
		for (j = 0; j < config->ignored_option_count; j++) {
			if (config->ignored_options[j] == i) {
				free(newlease->options[i].data);
				newlease->options[i].data = NULL;
				newlease->options[i].len = 0;
				break;
			}
		}
		if (j < config->ignored_option_count)
			continue;

		switch (config->default_actions[i]) {
		case ACTION_SUPERSEDE:
			free(newlease->options[i].data);
			newlease->options[i].len = config->defaults[i].len;
			newlease->options[i].data = calloc(1,
			    config->defaults[i].len);
			if (newlease->options[i].data == NULL)
				goto cleanup;
			memcpy(newlease->options[i].data,
			    config->defaults[i].data, config->defaults[i].len);
			break;

		case ACTION_PREPEND:
			free(newlease->options[i].data);
			newlease->options[i].len = config->defaults[i].len +
			    lease->options[i].len;
			newlease->options[i].data = calloc(1,
			    newlease->options[i].len);
			if (newlease->options[i].data == NULL)
				goto cleanup;
			memcpy(newlease->options[i].data,
			    config->defaults[i].data, config->defaults[i].len);
			memcpy(newlease->options[i].data +
			    config->defaults[i].len, lease->options[i].data,
			    lease->options[i].len);
			break;

		case ACTION_APPEND:
			free(newlease->options[i].data);
			newlease->options[i].len = config->defaults[i].len +
			    lease->options[i].len;
			newlease->options[i].data = calloc(1,
			    newlease->options[i].len);
			if (newlease->options[i].data == NULL)
				goto cleanup;
			memcpy(newlease->options[i].data,
			    lease->options[i].data, lease->options[i].len);
			memcpy(newlease->options[i].data +
			    lease->options[i].len, config->defaults[i].data,
			    config->defaults[i].len);
			break;

		case ACTION_DEFAULT:
			if ((newlease->options[i].len == 0) &&
			    (config->defaults[i].len != 0)) {
				newlease->options[i].len =
				    config->defaults[i].len;
				newlease->options[i].data = calloc(1,
				    config->defaults[i].len);
				if (newlease->options[i].data == NULL)
					goto cleanup;
				memcpy(newlease->options[i].data,
				    config->defaults[i].data,
				    config->defaults[i].len);
			}
			break;

		default:
			break;
		}
	}

	return (newlease);

cleanup:
	if (newlease) {
		newlease->is_static = 0;
		free_client_lease(newlease);
	}

	error("Unable to apply defaults");
	/* NOTREACHED */

	return (NULL);
}

struct client_lease *
clone_lease(struct client_lease *oldlease)
{
	struct client_lease *newlease;
	int i;

	newlease = calloc(1, sizeof(struct client_lease));
	if (newlease == NULL)
		goto cleanup;

	newlease->expiry = oldlease->expiry;
	newlease->renewal = oldlease->renewal;
	newlease->rebind = oldlease->rebind;
	newlease->is_static = oldlease->is_static;
	newlease->is_bootp = oldlease->is_bootp;
	newlease->address = oldlease->address;
	newlease->next_server = oldlease->next_server;

	if (oldlease->server_name) {
		newlease->server_name = strdup(oldlease->server_name);
		if (newlease->server_name == NULL)
			goto cleanup;
	}
	if (oldlease->filename) {
		newlease->filename = strdup(oldlease->filename);
		if (newlease->filename == NULL)
			goto cleanup;
	}
	if (oldlease->resolv_conf) {
		newlease->resolv_conf = strdup(oldlease->resolv_conf);
		if (newlease->resolv_conf == NULL)
			goto cleanup;
	}

	for (i = 0; i < 256; i++) {
		if (oldlease->options[i].len == 0)
			continue;
		newlease->options[i].len = oldlease->options[i].len;
		newlease->options[i].data = calloc(1, newlease->options[i].len);
		if (newlease->options[i].data == NULL)
			goto cleanup;
		memcpy(newlease->options[i].data, oldlease->options[i].data,
		    newlease->options[i].len);
	}

	return (newlease);

cleanup:
	if (newlease) {
		newlease->is_static = 0;
		free_client_lease(newlease);
	}

	return (NULL);
}

/*
 * Apply the list of options to be ignored that was provided on the
 * command line. This will override any ignore list obtained from
 * dhclient.conf.
 */
void
apply_ignore_list(char *ignore_list)
{
	u_int8_t list[256];
	char *p;
	int ix, i, j;

	memset(list, 0, sizeof(list));
	ix = 0;

	for (p = strsep(&ignore_list, ", "); p != NULL;
	    p = strsep(&ignore_list, ", ")) {
		if (*p == '\0')
			continue;

		for (i = 1; i < DHO_END; i++)
			if (!strcasecmp(dhcp_options[i].name, p))
				break;

		if (i == DHO_END) {
			note("Invalid option name: '%s'", p);
			return;
		}

		/* Avoid storing duplicate options in the list. */
		for (j = 0; j < ix && list[j] != i; j++)
			;
		if (j == ix)
			list[ix++] = i;
	}

	config->ignored_option_count = ix;
	memcpy(config->ignored_options, list, sizeof(config->ignored_options));
}

void
write_resolv_conf(u_int8_t *contents, size_t sz)
{
	int rslt;

	rslt = imsg_compose(unpriv_ibuf, IMSG_WRITE_RESOLV_CONF,
	    0, 0, -1, contents, sz);
	if (rslt == -1)
		warning("write_resolv_conf: imsg_compose: %s", strerror(errno));

	flush_unpriv_ibuf("write_resolv_conf");
}

void
write_option_db(u_int8_t *contents, size_t sz)
{
	int rslt;

	rslt = imsg_compose(unpriv_ibuf, IMSG_WRITE_OPTION_DB,
	    0, 0, -1, contents, sz);
	if (rslt == -1)
		warning("write_option_db: imsg_compose: %s", strerror(errno));

	flush_unpriv_ibuf("write_option_db");
}

void
priv_write_resolv_conf(struct imsg *imsg)
{
	u_int8_t *contents;
	size_t sz;

	if (imsg->hdr.len < IMSG_HEADER_SIZE) {
		warning("short IMSG_WRITE_RESOLV_CONF");
		return;
	}

	if (!resolv_conf_priority())
		return;

	contents = imsg->data;
	sz = imsg->hdr.len - IMSG_HEADER_SIZE;

	priv_write_file("/etc/resolv.conf",
	    O_WRONLY | O_CREAT | O_TRUNC,
	    S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH, contents, sz);
}

void
priv_write_option_db(struct imsg *imsg)
{
	u_int8_t *contents;
	size_t sz;

	if (imsg->hdr.len < IMSG_HEADER_SIZE) {
		warning("short IMSG_WRITE_OPTION_DB");
		return;
	}

	contents = imsg->data;
	sz = imsg->hdr.len - IMSG_HEADER_SIZE;

	priv_write_file(path_option_db,
	    O_WRONLY | O_CREAT | O_TRUNC | O_NOFOLLOW,
	    S_IRUSR | S_IWUSR | S_IRGRP, contents, sz);
}

void
priv_write_file(char *path, int flags, mode_t mode,
    u_int8_t *contents, size_t sz)
{
	ssize_t n;
	int fd;

	fd = open(path, flags, mode);
	if (fd == -1) {
		note("Couldn't open '%s': %s", path, strerror(errno));
		return;
	}

	n = write(fd, contents, sz);
	if (n == -1)
		note("Couldn't write contents to '%s': %s", path,
		    strerror(errno));
	else if (n < sz)
		note("Short contents write to '%s' (%zd vs %zu)", path,
		    n, sz);

	if (fchown(fd, 0, 0) == -1)
		note("fchown(fd, %d, %d) of '%s' failed (%s)",
		    0, 0, path, strerror(errno));
	if (fchmod(fd, mode) == -1)
		note("fchmod(fd, 0x%x) of '%s' failed (%s)", mode,
		    path, strerror(errno));

	close(fd);
}

/*
 * add_direct_route is the equivalent of
 *
 *     route add -net $dest -netmask $mask -cloning -iface $iface
 */
void
add_direct_route(struct in_addr dest, struct in_addr mask, struct in_addr iface)
{
	struct in_addr ifa = { INADDR_ANY };

	add_route(dest, mask, iface, ifa,
	    RTA_DST | RTA_NETMASK | RTA_GATEWAY, RTF_CLONING | RTF_STATIC);
}

/*
 * add_default_route is the equivalent of
 *
 *	route -q $rdomain add default -iface $router
 *
 *	or
 *
 *	route -q $rdomain add default $router
 */
void
add_default_route(struct in_addr addr, struct in_addr gateway)
{
	struct in_addr netmask, dest;
	int addrs, flags;

	memset(&netmask, 0, sizeof(netmask));
	memset(&dest, 0, sizeof(dest));
	addrs = RTA_DST | RTA_NETMASK;
	flags = 0;

	/*
	 * When 'addr' and 'gateway' are identical the desired behaviour is
	 * to emulate the '-iface' variant of 'route'. This is done by
	 * claiming there is no gateway address to use.
	 */
	if (memcmp(&gateway, &addr, sizeof(addr)) != 0) {
		addrs |= RTA_GATEWAY | RTA_IFA;
		flags |= RTF_GATEWAY | RTF_STATIC;
	}

	add_route(dest, netmask, gateway, addr, addrs, flags);
}

void
add_static_routes(struct option_data *static_routes, struct in_addr iface)
{
	struct in_addr		 dest, netmask, gateway;
	struct in_addr		 *addr;
	int			 i;

	netmask.s_addr = INADDR_ANY;	/* Not used for CLASSFULL! */

	for (i = 0; (i + 2*sizeof(*addr)) <= static_routes->len;
	    i += 2*sizeof(*addr)) {
		addr = (struct in_addr *)&static_routes->data[i];
		if (addr->s_addr == INADDR_ANY)
			continue; /* RFC 2132 says 0.0.0.0 is not allowed. */

		dest.s_addr = addr->s_addr;
		gateway.s_addr = (addr+1)->s_addr;

		/* XXX Order implies priority but we're ignoring that. */
		add_route(dest, netmask, gateway, iface,
		    RTA_DST | RTA_GATEWAY | RTA_IFA, RTF_GATEWAY | RTF_STATIC);
	}
}

void
add_classless_static_routes(struct option_data *opt, struct in_addr iface)
{
	struct in_addr	 dest, netmask, gateway;
	int		 bits, bytes, i;

	i = 0;
	while (i < opt->len) {
		bits = opt->data[i++];
		bytes = (bits + 7) / 8;

		if (bytes > sizeof(netmask))
			return;
		else if (i + bytes > opt->len)
			return;

		if (bits)
			netmask.s_addr = htonl(0xffffffff << (32 - bits));
		else
			netmask.s_addr = INADDR_ANY;

		memcpy(&dest, &opt->data[i], bytes);
		dest.s_addr = dest.s_addr & netmask.s_addr;
		i += bytes;

		if (i + sizeof(gateway) > opt->len)
			return;
		memcpy(&gateway, &opt->data[i], sizeof(gateway));
		i += sizeof(gateway);

		if (gateway.s_addr == INADDR_ANY)
			add_direct_route(dest, netmask, iface);
		else
			add_route(dest, netmask, gateway, iface,
			    RTA_DST | RTA_GATEWAY | RTA_NETMASK | RTA_IFA,
			    RTF_GATEWAY | RTF_STATIC);
	}
}

int
compare_lease(struct client_lease *active, struct client_lease *new)
{
	int i;

	if (active == new)
		return (0);

	if (!new || !active)
		return (1);

	if (active->address.s_addr != new->address.s_addr ||
	    active->is_static != new->is_static ||
	    active->is_bootp != new->is_bootp)
		return (1);

	if (active->server_name != new->server_name) {
		if (!active->server_name || !new->server_name)
			return (1);
		if (strcmp(active->server_name, new->server_name) != 0)
			return (1);
	}

	if (active->filename != new->filename) {
		if (!active->filename || !new->filename)
			return (1);
		if (strcmp(active->filename, new->filename) != 0)
			return (1);
	}

	for (i = 0; i < 256; i++) {
		if (active->options[i].len != new->options[i].len)
			return (1);
		if (memcmp(active->options[i].data, new->options[i].data,
		    active->options[i].len))
			return (1);
	}

	return (0);
}

void
set_lease_times(struct client_lease *lease)
{
	time_t cur_time, time_max;
	u_int32_t uint32val;

	time(&cur_time);

	time_max = LLONG_MAX - cur_time;
	if (time_max > UINT32_MAX)
		time_max = UINT32_MAX;

	/*
	 * Take the server-provided times if available.  Otherwise
	 * figure them out according to the spec.
	 *
	 * expiry  == time to discard lease.
	 * renewal == time to renew lease from server that provided it.
	 * rebind  == time to renew lease from any server.
	 *
	 * 0 <= renewal <= rebind <= expiry <= time_max
	 * &&
	 * expiry >= MIN(time_max, 60)
	 */

	lease->expiry = 43200;	/* Default to 12 hours */
	if (lease->options[DHO_DHCP_LEASE_TIME].len == sizeof(uint32val)) {
		memcpy(&uint32val, lease->options[DHO_DHCP_LEASE_TIME].data,
		    sizeof(uint32val));
		lease->expiry = ntohl(uint32val);
		if (lease->expiry < 60)
			lease->expiry = 60;
	}
	if (lease->expiry > time_max)
		lease->expiry = time_max;

	lease->renewal = lease->expiry / 2;
	if (lease->options[DHO_DHCP_RENEWAL_TIME].len == sizeof(uint32val)) {
		memcpy(&uint32val, lease->options[DHO_DHCP_RENEWAL_TIME].data,
		    sizeof(uint32val));
		lease->renewal = ntohl(uint32val);
		if (lease->renewal > lease->expiry)
			lease->renewal = lease->expiry;
	}

	lease->rebind = (lease->expiry * 7) / 8;
	if (lease->options[DHO_DHCP_REBINDING_TIME].len == sizeof(uint32val)) {
		memcpy(&uint32val, lease->options[DHO_DHCP_REBINDING_TIME].data,
		    sizeof(uint32val));
		lease->rebind = ntohl(uint32val);
		if (lease->rebind > lease->expiry)
			lease->rebind = lease->expiry;
	}
	if (lease->rebind < lease->renewal)
		lease->rebind = lease->renewal;

	/* Convert lease lengths to times. */
	lease->expiry += cur_time;
	lease->renewal += cur_time;
	lease->rebind += cur_time;
}

Generated by: GCOVR (Version 3.3)