dhcpcd.c

/* 
 * dhcpcd - DHCP client daemon
 * Copyright 2006-2008 Roy Marples <roy@marples.name>
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */

const char copyright[] = "Copyright (c) 2006-2008 Roy Marples";

#include <sys/file.h>
#include <sys/stat.h>
#include <sys/types.h>

#include <arpa/inet.h>

#include <ctype.h>
#include <errno.h>
#include <getopt.h>
#include <paths.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <time.h>

#include "config.h"
#include "client.h"
#include "dhcpcd.h"
#include "dhcp.h"
#include "net.h"
#include "logger.h"

#ifdef ANDROID
#include <linux/capability.h>
#include <linux/prctl.h>
#include <cutils/properties.h>
#include <private/android_filesystem_config.h>
#endif

/* Don't set any optional arguments here so we retain POSIX
 * compatibility with getopt */
#define OPTS "bc:df:h:i:kl:m:no:pqr:s:t:u:v:xABC:DEF:GI:KLO:Q:TVX:"

static int doversion = 0;
static int dohelp = 0;
static const struct option longopts[] = {
	{"background",    no_argument,        NULL, 'b'},
	{"script",        required_argument,  NULL, 'c'},
	{"debug",         no_argument,        NULL, 'd'},
	{"config",        required_argument,  NULL, 'f'},
	{"hostname",      optional_argument,  NULL, 'h'},
	{"vendorclassid", optional_argument,  NULL, 'i'},
	{"release",       no_argument,        NULL, 'k'},
	{"leasetime",     required_argument,  NULL, 'l'},
	{"metric",        required_argument,  NULL, 'm'},
	{"rebind",        no_argument,        NULL, 'n'},
	{"option",        required_argument,  NULL, 'o'},
	{"persistent",    no_argument,        NULL, 'p'},
	{"quiet",         no_argument,        NULL, 'q'},
	{"request",       optional_argument,  NULL, 'r'},
	{"inform",        optional_argument,  NULL, 's'},
	{"timeout",       required_argument,  NULL, 't'},
	{"userclass",     required_argument,  NULL, 'u'},
	{"vendor",        required_argument,  NULL, 'v'},
	{"exit",          no_argument,        NULL, 'x'},
	{"noarp",         no_argument,        NULL, 'A'},
	{"nobackground",  no_argument,        NULL, 'B'},
	{"nohook",	  required_argument,  NULL, 'C'},
	{"duid",          no_argument,        NULL, 'D'},
	{"lastlease",     no_argument,        NULL, 'E'},
	{"fqdn",          optional_argument,  NULL, 'F'},
	{"nogateway",     no_argument,        NULL, 'G'},
	{"clientid",      optional_argument,  NULL, 'I'},
	{"nolink",        no_argument,        NULL, 'K'},
	{"noipv4ll",      no_argument,        NULL, 'L'},
	{"nooption",      optional_argument,  NULL, 'O'},
	{"require",       required_argument,  NULL, 'Q'},
	{"test",          no_argument,        NULL, 'T'},
	{"variables",     no_argument,        NULL, 'V'},
	{"blacklist",     required_argument,  NULL, 'X'},
	{"help",          no_argument,        &dohelp, 1},
	{"version",       no_argument,        &doversion, 1},
#ifdef CMDLINE_COMPAT
	{"classid",       optional_argument,  NULL, 'i'},
	{"renew",         no_argument,        NULL, 'n'},
	{"nohostname",    no_argument,        NULL, 'H'},
	{"nomtu",         no_argument,        NULL, 'M'},
	{"nontp",         no_argument,        NULL, 'N'},
	{"nodns",         no_argument,        NULL, 'R'},
	{"msscr",         no_argument,        NULL, 'S'},
	{"nonis",         no_argument,        NULL, 'Y'},
#endif
	{NULL,          0,                  NULL, '\0'}
};

#ifdef CMDLINE_COMPAT
# define EXTRA_OPTS "HMNRSY"
#endif

#ifndef EXTRA_OPTS
# define EXTRA_OPTS
#endif

static int
atoint(const char *s)
{
	char *t;
	long n;

	errno = 0;
	n = strtol(s, &t, 0);
	if ((errno != 0 && n == 0) || s == t ||
	    (errno == ERANGE && (n == LONG_MAX || n == LONG_MIN)))
	{
		logger(LOG_ERR, "`%s' out of range", s);
		return -1;
	}

	return (int)n;
}

static pid_t
read_pid(const char *pidfile)
{
	FILE *fp;
	pid_t pid;

	if ((fp = fopen(pidfile, "r")) == NULL) {
		errno = ENOENT;
		return 0;
	}

	if (fscanf(fp, "%d", &pid) != 1)
		pid = 0;
	fclose(fp);

	return pid;
}

static void
usage(void)
{
	printf("usage: "PACKAGE" [-dknpqxADEGHKLOTV] [-c script] [-f file ] [-h hostname]\n"
	       "              [-i classID ] [-l leasetime] [-m metric] [-o option] [-r ipaddr]\n"
	       "              [-s ipaddr] [-t timeout] [-u userclass] [-F none|ptr|both]\n"
	       "              [-I clientID] [-C hookscript] [-Q option] [-X ipaddr] <interface>\n");
}

static char * 
add_environ(struct options *options, const char *value, int uniq)
{
	char **newlist;
	char **lst = options->environ;
	size_t i = 0, l, lv;
	char *match = NULL, *p;

	match = xstrdup(value);
	p = strchr(match, '=');
	if (p)
		*p++ = '\0';
	l = strlen(match);

	while (lst && lst[i]) {
		if (match && strncmp(lst[i], match, l) == 0) {
			if (uniq) {
				free(lst[i]);
				lst[i] = xstrdup(value);
			} else {
				/* Append a space and the value to it */
				l = strlen(lst[i]);
				lv = strlen(p);
				lst[i] = xrealloc(lst[i], l + lv + 2);
				lst[i][l] = ' ';
				memcpy(lst[i] + l + 1, p, lv);
				lst[i][l + lv + 1] = '\0';
			}
			free(match);
			return lst[i];
		}
		i++;
	}

	newlist = xrealloc(lst, sizeof(char *) * (i + 2));
	newlist[i] = xstrdup(value);
	newlist[i + 1] = NULL;
	options->environ = newlist;
	free(match);
	return newlist[i];
}

#define parse_string(buf, len, arg) parse_string_hwaddr(buf, len, arg, 0)
static ssize_t
parse_string_hwaddr(char *sbuf, ssize_t slen, char *str, int clid)
{
	ssize_t l;
	char *p;
	int i;
	char c[4];

	/* If surrounded by quotes then it's a string */
	if (*str == '"') {
		str++;
		l = strlen(str);
		p = str + l - 1;
		if (*p == '"')
			*p = '\0';
	} else {
		l = hwaddr_aton(NULL, str);
		if (l > 1) {
			if (l > slen) {
				errno = ENOBUFS;
				return -1;
			}
			hwaddr_aton((uint8_t *)sbuf, str);
			return l;
		}
	}

	/* Process escapes */
	l = 0;
	/* If processing a string on the clientid, first byte should be
	 * 0 to indicate a non hardware type */
	if (clid && *str) {
		*sbuf++ = 0;
		l++;
	}
	c[3] = '\0';
	while (*str) {
		if (++l > slen) {
			errno = ENOBUFS;
			return -1;
		}
		if (*str == '\\') {
			str++;
			switch(*str++) {
			case '\0':
				break;
			case 'b':
				*sbuf++ = '\b';
				break;
			case 'n':
				*sbuf++ = '\n';
				break;
			case 'r':
				*sbuf++ = '\r';
				break;
			case 't':
				*sbuf++ = '\t';
				break;
			case 'x':
				/* Grab a hex code */
				c[1] = '\0';
				for (i = 0; i < 2; i++) {
					if (isxdigit((unsigned char)*str) == 0)
						break;
					c[i] = *str++;
				}
				if (c[1] != '\0') {
					c[2] = '\0';
					*sbuf++ = strtol(c, NULL, 16);
				} else
					l--;
				break;
			case '0':
				/* Grab an octal code */
				c[2] = '\0';
				for (i = 0; i < 3; i++) {
					if (*str < '0' || *str > '7')
						break;
					c[i] = *str++;
				}
				if (c[2] != '\0') {
					i = strtol(c, NULL, 8);
					if (i > 255)
						i = 255;
					*sbuf ++= i;
				} else
					l--;
				break;
			default:
				*sbuf++ = *str++;
			}
		} else
			*sbuf++ = *str++;
	}
	return l;
}

static int
parse_option(int opt, char *oarg, struct options *options)
{
	int i;
	char *p;
	ssize_t s;
	struct in_addr addr;

	switch(opt) {
	case 'b':
		options->options |= DHCPCD_BACKGROUND;
		break;
	case 'c':
		strlcpy(options->script, oarg, sizeof(options->script));
		break;
	case 'h':
		if (oarg)
			s = parse_string(options->hostname,
					 HOSTNAME_MAX_LEN, oarg);
		else
			s = 0;
		if (s == -1) {
			logger(LOG_ERR, "hostname: %s", strerror(errno));
			return -1;
		}
		if (s != 0 && options->hostname[0] == '.') {
			logger(LOG_ERR, "hostname cannot begin with a .");
			return -1;
		}
		options->hostname[s] = '\0';
		break;
	case 'i':
		if (oarg)
			s = parse_string((char *)options->vendorclassid + 1,
					 VENDORCLASSID_MAX_LEN, oarg);
		else
			s = 0;
		if (s == -1) {
			logger(LOG_ERR, "vendorclassid: %s", strerror(errno));
			return -1;
		}
		*options->vendorclassid = (uint8_t)s;
		break;
	case 'l':
		if (*oarg == '-') {
			logger(LOG_ERR,
			       "leasetime must be a positive value");
			return -1;
		}
		errno = 0;
		options->leasetime = (uint32_t)strtol(oarg, NULL, 0);
		if (errno == EINVAL || errno == ERANGE) {
			logger(LOG_ERR, "`%s' out of range", oarg);
			return -1;
		}
		break;
	case 'm':
		options->metric = atoint(oarg);
		if (options->metric < 0) {
			logger(LOG_ERR, "metric must be a positive value");
			return -1;
		}
		break;
	case 'o':
		if (make_option_mask(options->requestmask, &oarg, 1) != 0) {
			logger(LOG_ERR, "unknown option `%s'", oarg);
			return -1;
		}
		break;
	case 'p':
		options->options |= DHCPCD_PERSISTENT;
		break;
	case 'q':
		setloglevel(LOG_WARNING);
		break;
	case 's':
		options->options |= DHCPCD_INFORM;
		options->options |= DHCPCD_PERSISTENT;
		options->options &= ~DHCPCD_ARP;
		if (!oarg || *oarg == '\0') {
			options->request_address.s_addr = 0;
			break;
		} else {
			if ((p = strchr(oarg, '/'))) {
				/* nullify the slash, so the -r option
				 * can read the address */
				*p++ = '\0';
				if (sscanf(p, "%d", &i) != 1 ||
				    inet_cidrtoaddr(i, &options->request_netmask) != 0)
				{
					logger(LOG_ERR,
					       "`%s' is not a valid CIDR",
					       p);
					return -1;
				}
			}
		}
		/* FALLTHROUGH */
	case 'r':
		if (!(options->options & DHCPCD_INFORM))
			options->options |= DHCPCD_REQUEST;
		if (oarg && !inet_aton(oarg, &options->request_address)) {
			logger(LOG_ERR, "`%s' is not a valid IP address",
			       oarg);
			return -1;
		}
		break;
	case 't':
		options->timeout = atoint(oarg);
		if (options->timeout < 0) {
			logger (LOG_ERR, "timeout must be a positive value");
			return -1;
		}
		break;
	case 'u':
		s = USERCLASS_MAX_LEN - options->userclass[0] - 1;
		s = parse_string((char *)options->userclass + options->userclass[0] + 2,
				 s, oarg);
		if (s == -1) {
			logger(LOG_ERR, "userclass: %s", strerror(errno));
			return -1;
		}
		if (s != 0) {
			options->userclass[options->userclass[0] + 1] = s;
			options->userclass[0] += s + 1;
		}
		break;
	case 'v':
		p = strchr(oarg, ',');
		if (!p || !p[1]) {
			logger(LOG_ERR, "invalid vendor format");
			return -1;
		}
		*p = '\0';
		i = atoint(oarg);
		oarg = p + 1;
		if (i < 1 || i > 254) {
			logger(LOG_ERR, "vendor option should be between"
					" 1 and 254 inclusive");
			return -1;
		}
		s = VENDOR_MAX_LEN - options->vendor[0] - 2;
		if (inet_aton(oarg, &addr) == 1) {
			if (s < 6) {
				s = -1;
				errno = ENOBUFS;
			} else
				memcpy(options->vendor + options->vendor[0] + 3,
				       &addr.s_addr, sizeof(addr.s_addr));
		} else {
			s = parse_string((char *)options->vendor + options->vendor[0] + 3,
					 s, oarg);
		}
		if (s == -1) {
			logger(LOG_ERR, "vendor: %s", strerror(errno));
			return -1;
		}
		if (s != 0) {
			options->vendor[options->vendor[0] + 1] = i;
			options->vendor[options->vendor[0] + 2] = s;
			options->vendor[0] += s + 2;
		}
		break;
	case 'A':
		options->options &= ~DHCPCD_ARP;
		/* IPv4LL requires ARP */
		options->options &= ~DHCPCD_IPV4LL;
		break;
	case 'B':
		options->options &= ~DHCPCD_DAEMONISE;
		break;
	case 'C':
		/* Commas to spaces for shell */
		while ((p = strchr(oarg, ',')))
			*p = ' ';
		s = strlen("skip_hooks=") + strlen(oarg) + 1;
		p = xmalloc(sizeof(char) * s);
		snprintf(p, s, "skip_hooks=%s", oarg);
		add_environ(options, p, 0);
		free(p);
		break;
	case 'D':
		options->options |= DHCPCD_DUID;
		break;
	case 'E':
		options->options |= DHCPCD_LASTLEASE;
		break;
	case 'F':
		if (!oarg) {
			options->fqdn = FQDN_BOTH;
			break;
		}
		if (strcmp(oarg, "none") == 0)
			options->fqdn = FQDN_NONE;
		else if (strcmp(oarg, "ptr") == 0)
			options->fqdn = FQDN_PTR;
		else if (strcmp(oarg, "both") == 0)
			options->fqdn = FQDN_BOTH;
		else if (strcmp(oarg, "disable") == 0)
			options->fqdn = FQDN_DISABLE;
		else {
			logger(LOG_ERR, "invalid value `%s' for FQDN",
			       oarg);
			return -1;
		}
		break;
	case 'G':
		options->options &= ~DHCPCD_GATEWAY;
		break;
	case 'I':
		/* Strings have a type of 0 */;
		options->clientid[1] = 0;
		if (oarg)
			s = parse_string_hwaddr((char *)options->clientid + 1,
						CLIENTID_MAX_LEN, oarg, 1);
		else
			s = 0;
		if (s == -1) {
			logger(LOG_ERR, "clientid: %s", strerror(errno));
			return -1;
		}
		options->clientid[0] = (uint8_t)s;
#ifdef CMDLINE_COMPAT
		if (s == 0) {
			options->options &= ~DHCPCD_DUID;
			options->options &= ~DHCPCD_CLIENTID;
		}
#else
		options->options |= DHCPCD_CLIENTID;
#endif
		break;
	case 'K':
		options->options &= ~DHCPCD_LINK;
		break;
	case 'L':
		options->options &= ~DHCPCD_IPV4LL;
		break;
	case 'O':
		if (make_option_mask(options->requestmask, &oarg, -1) != 0 ||
		    make_option_mask(options->requiremask, &oarg, -1) != 0 ||
		    make_option_mask(options->nomask, &oarg, 1) != 0)
		{
			logger(LOG_ERR, "unknown option `%s'", oarg);
			return -1;
		}
		break;
	case 'Q':
		if (make_option_mask(options->requiremask, &oarg, 1) != 0 ||
		    make_option_mask(options->requestmask, &oarg, 1) != 0)
		{
			logger(LOG_ERR, "unknown option `%s'", oarg);
			return -1;
		}
		break;
	case 'X':
		if (!inet_aton(oarg, &addr)) {
			logger(LOG_ERR, "`%s' is not a valid IP address",
			       oarg);
			return -1;
		}
		options->blacklist = xrealloc(options->blacklist,
		    sizeof(in_addr_t) * (options->blacklist_len + 1));
		options->blacklist[options->blacklist_len] = addr.s_addr;
		options->blacklist_len++;
		break;
	default:
		return 0;
	}

	return 1;
}

static int
parse_config_line(const char *opt, char *line, struct options *options)
{
	unsigned int i;

	for (i = 0; i < sizeof(longopts) / sizeof(longopts[0]); i++) {
		if (!longopts[i].name ||
		    strcmp(longopts[i].name, opt) != 0)
			continue;

		if (longopts[i].has_arg == required_argument && !line) {
			fprintf(stderr,
				PACKAGE ": option requires an argument -- %s\n",
				opt);
			return -1;
		}

		return parse_option(longopts[i].val, line, options);
	}

	fprintf(stderr, PACKAGE ": unknown option -- %s\n", opt);
	return -1;
}

#ifdef ANDROID
void switchUser() {
	gid_t groups[] = { AID_INET, AID_SHELL };
	setgroups(sizeof(groups)/sizeof(groups[0]), groups);

	prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0);

	setgid(AID_DHCP);
	setuid(AID_DHCP);

	struct __user_cap_header_struct header;
	struct __user_cap_data_struct cap;
	header.version = _LINUX_CAPABILITY_VERSION;
	header.pid = 0;
	cap.effective = cap.permitted =
		(1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) |
                (1 << CAP_NET_BROADCAST) | (1 << CAP_NET_BIND_SERVICE);
	cap.inheritable = 0;
	capset(&header, &cap);
}
#endif /* ANDROID */

int
main(int argc, char **argv)
{
	struct options *options;
	int opt;
	int option_index = 0;
	char *prefix;
	pid_t pid;
	int debug = 0;
	int i, r;
	int pid_fd = -1;
	int sig = 0;
	int retval = EXIT_FAILURE;
	char *line, *option, *p, *buffer = NULL;
	size_t len = 0;
	FILE *f;
	char *cf = NULL;
	char *intf = NULL;
	struct timespec ts;

#ifdef ANDROID
	switchUser();
#endif
	closefrom(3);
	/* Saves calling fflush(stream) in the logger */
	setlinebuf(stdout);
	openlog(PACKAGE, LOG_PID, LOG_DAEMON);
	setlogprefix(PACKAGE ": ");

	options = xzalloc(sizeof(*options));
	options->options |= DHCPCD_GATEWAY | DHCPCD_DAEMONISE;
	options->options |= DHCPCD_ARP | DHCPCD_IPV4LL | DHCPCD_LINK;
	options->timeout = DEFAULT_TIMEOUT;
	strlcpy(options->script, SCRIPT, sizeof(options->script));

	options->vendorclassid[0] = snprintf((char *)options->vendorclassid + 1,
					     VENDORCLASSID_MAX_LEN,
					     "%s %s", PACKAGE, VERSION);

	/* Explicitly include DNS in the list of parameters requested in the DNS request.
	 * Without this some DHCP servers may skip the DNS entries in the DHCP replies.*/
	add_option_mask(options->requestmask, DHO_DNSSERVER);
	add_option_mask(options->requestmask, DHO_DNSDOMAIN);
	add_option_mask(options->requestmask, DHO_DNSSEARCH);

#ifdef CMDLINE_COMPAT
	options->options |= DHCPCD_CLIENTID;
	add_option_mask(options->requestmask, DHO_NISSERVER);
	add_option_mask(options->requestmask, DHO_NISDOMAIN);
	add_option_mask(options->requestmask, DHO_NTPSERVER);

	/* If the duid file exists, then enable duid by default
	 * This means we don't break existing clients that easily :) */
	if ((f = fopen(DUID, "r"))) {
		options->options |= DHCPCD_DUID;
		fclose(f);
	}
#endif

	gethostname(options->hostname, HOSTNAME_MAX_LEN);
	/* Ensure that the hostname is NULL terminated */ 
	options->hostname[HOSTNAME_MAX_LEN] = '\0';
	if (strcmp(options->hostname, "(none)") == 0 ||
	    strcmp(options->hostname, "localhost") == 0)
		options->hostname[0] = '\0';

	while ((opt = getopt_long(argc, argv, OPTS EXTRA_OPTS,
				  longopts, &option_index)) != -1)
	{
		switch (opt) {
		case 0:
			if (longopts[option_index].flag)
				break;
			logger(LOG_ERR,	"option `%s' should set a flag",
			       longopts[option_index].name);
			goto abort;
		case 'f':
			cf = optarg;
			break;
		case 'V':
			print_options();
			goto abort;
		case '?':
			usage();
			goto abort;
		}
	}

	if (doversion)
		printf(""PACKAGE" "VERSION"\n%s\n", copyright);

	if (dohelp)
		usage();

	if (optind < argc) {
		if (strlen(argv[optind]) >= IF_NAMESIZE) {
			logger(LOG_ERR,
			       "`%s' too long for an interface name (max=%d)",
			       argv[optind], IF_NAMESIZE);
			goto abort;
		}
		strlcpy(options->interface, argv[optind],
			sizeof(options->interface));
	} else {
		/* If only version was requested then exit now */
		if (doversion || dohelp) {
			retval = 0;
			goto abort;
		}

		logger(LOG_ERR, "no interface specified");
		goto abort;
	}

	/* Parse our options file */
	f = fopen(cf ? cf : CONFIG, "r");
	if (f) {
		r = 1;
		while ((get_line(&buffer, &len, f))) {
			line = buffer;
			while ((option = strsep(&line, " \t")))
				if (*option != '\0')
					break;
			if (!option || *option == '\0' || *option == '#')
				continue;
			/* Trim leading whitespace */
			if (line) {
				while (*line != '\0' && (*line == ' ' || *line == '\t'))
					line++;
			}
			/* Trim trailing whitespace */
			if (line && *line) {
				p = line + strlen(line) - 1;
				while (p != line &&
				       (*p == ' ' || *p == '\t') &&
				       *(p - 1) != '\\')
					*p-- = '\0';
			}
			if (strcmp(option, "interface") == 0) {
				free(intf);
				intf = xstrdup(line);
				continue;
			}
			/* If we're in an interface block don't use these
			 * options unless it's for us */
			if (intf && strcmp(intf, options->interface) != 0)
				continue;
			r = parse_config_line(option, line, options);
			if (r != 1)
				break;
		}
		free(buffer);
		free(intf);
		fclose(f);
		if (r == 0)
			usage();
		if (r != 1)
			goto abort;
	} else {
		if (errno != ENOENT || cf) {
			logger(LOG_ERR, "fopen `%s': %s", cf ? cf : CONFIG,
			       strerror(errno));
			goto abort;
		}
	}

	optind = 0;
	while ((opt = getopt_long(argc, argv, OPTS EXTRA_OPTS,
				  longopts, &option_index)) != -1)
	{
		switch (opt) {
		case 'd':
			debug++;
			switch (debug) {
			case 1:
				setloglevel(LOG_DEBUG);
				break;
			case 2:
				options->options &= ~DHCPCD_DAEMONISE;
				break;
			}
			break;
		case 'f':
			break;
		case 'k':
			sig = SIGHUP;
			break;
		case 'n':
			sig = SIGALRM;
			break;
		case 'x':
			sig = SIGTERM;
			break;
		case 'T':
			options->options |= DHCPCD_TEST | DHCPCD_PERSISTENT;
			break;
#ifdef CMDLINE_COMPAT
		case 'H': /* FALLTHROUGH */
		case 'M':
			del_option_mask(options->requestmask, DHO_MTU);
			add_environ(options, "skip_hooks=mtu", 0);
			break;
		case 'N':
			del_option_mask(options->requestmask, DHO_NTPSERVER);
			add_environ(options, "skip_hooks=ntp.conf", 0);
			break;
		case 'R':
			del_option_mask(options->requestmask, DHO_DNSSERVER);
			del_option_mask(options->requestmask, DHO_DNSDOMAIN);
			del_option_mask(options->requestmask, DHO_DNSSEARCH);
			add_environ(options, "skip_hooks=resolv.conf", 0);
			break;
		case 'S':
			add_option_mask(options->requestmask, DHO_MSCSR);
			break;
		case 'Y':
			del_option_mask(options->requestmask, DHO_NISSERVER);
			del_option_mask(options->requestmask, DHO_NISDOMAIN);
			add_environ(options, "skip_hooks=yp.conf", 0);
			break;
#endif
		default:
			i = parse_option(opt, optarg, options);
			if (i == 1)
				break;
			if (i == 0)
				usage();
			goto abort;
		}
	}

#ifdef THERE_IS_NO_FORK
	options->options &= ~DHCPCD_DAEMONISE;
#endif

#ifndef ANDROID
        /* android runs us as user "dhcp" */
	if (geteuid())
		logger(LOG_WARNING, PACKAGE " will not work correctly unless"
		       " run as root");
#endif

	if (options->options & DHCPCD_TEST) {
		if (options->options & DHCPCD_REQUEST ||
		    options->options & DHCPCD_INFORM) {
			logger(LOG_ERR,
			       "cannot test with --inform or --request");
			goto abort;
		}

		if (options->options & DHCPCD_LASTLEASE) {
			logger(LOG_ERR, "cannot test with --lastlease");
			goto abort;
		}

		if (sig != 0) {
			logger(LOG_ERR,
			       "cannot test with --release or --renew");
			goto abort;
		}
	}

	prefix = xmalloc(sizeof(char) * (IF_NAMESIZE + 3));
	snprintf(prefix, IF_NAMESIZE, "%s: ", options->interface);
	setlogprefix(prefix);
	snprintf(options->pidfile, sizeof(options->pidfile), PIDFILE,
		 options->interface);
	free(prefix);

	if (options->request_address.s_addr == 0 &&
	    (options->options & DHCPCD_INFORM ||
	     options->options & DHCPCD_REQUEST))
	{
		errno = 0;
		if (get_address(options->interface,
				&options->request_address,
				&options->request_netmask) != 1)
		{
			if (errno)
				logger(LOG_ERR, "get_address: %s",
				       strerror(errno));
			else
				logger(LOG_ERR, "no existing address");
			goto abort;
		}
	}
	if (IN_LINKLOCAL(ntohl(options->request_address.s_addr))) {
		logger(LOG_ERR,
		       "you are not allowed to request a link local address");
		goto abort;
	}

	if (chdir("/") == -1)
		logger(LOG_ERR, "chdir `/': %s", strerror(errno));
	umask(022);

	if (sig != 0 && !(options->options & DHCPCD_DAEMONISED)) {
#ifdef ANDROID
                char pidpropname[PROPERTY_KEY_MAX];
                char pidpropval[PROPERTY_VALUE_MAX];

		i = -1;
                if (snprintf(pidpropname,
                             sizeof(pidpropname),
                             "dhcp.%s.pid", options->interface) >= PROPERTY_KEY_MAX) {
                    goto abort;
                }
                property_get(pidpropname, pidpropval, NULL);
                if (strlen(pidpropval) == 0) {
                    goto abort;
                }
                pid = atoi(pidpropval);
#else
		i = -1;
		pid = read_pid(options->pidfile);
#endif
		if (pid != 0)
			logger(LOG_INFO, "sending signal %d to pid %d",
			       sig, pid);

		if (!pid || (i = kill(pid, sig))) {
			if (sig != SIGALRM)
				logger(LOG_ERR, ""PACKAGE" not running");
			unlink(options->pidfile);
		}
		if (i == 0) {
			if (sig == SIGALRM) {
				retval = EXIT_SUCCESS;
				goto abort;
			}
			/* Spin until it exits */
			logger(LOG_INFO, "waiting for pid %d to exit", pid);
			ts.tv_sec = 0;
			ts.tv_nsec = 100000000; /* 10th of a second */
			for(i = 0; i < 100; i++) {
				nanosleep(&ts, NULL);
				if (read_pid(options->pidfile) == 0) {
					retval = EXIT_SUCCESS;
					break;
				}
			}
			if (retval != EXIT_SUCCESS)
				logger(LOG_ERR, "pid %d failed to exit", pid);
			goto abort;
		}
		if (sig != SIGALRM)
			goto abort;	
	}

	if (!(options->options & DHCPCD_TEST) &&
	    !(options->options & DHCPCD_DAEMONISED))
	{
#ifdef ANDROID
                char pidpropname[PROPERTY_KEY_MAX];
                char pidpropval[PROPERTY_VALUE_MAX];
#endif
#ifndef ANDROID
		if ((pid = read_pid(options->pidfile)) > 0 &&
		    kill(pid, 0) == 0)
		{
			logger(LOG_ERR, ""PACKAGE
			       " already running on pid %d (%s)",
			       pid, options->pidfile);
			goto abort;
		}
#endif
		pid_fd = open(options->pidfile,
			     O_WRONLY | O_CREAT | O_NONBLOCK, 0664);
		if (pid_fd == -1) {
			logger(LOG_ERR, "open `%s': %s",
			       options->pidfile, strerror(errno));
			goto abort;
		}

		/* Lock the file so that only one instance of dhcpcd runs
		 * on an interface */
		if (flock(pid_fd, LOCK_EX | LOCK_NB) == -1) {
			logger(LOG_ERR, "flock `%s': %s",
			       options->pidfile, strerror(errno));
			goto abort;
		}

		if (set_cloexec(pid_fd) == -1)
			goto abort;
#ifdef ANDROID
                if (snprintf(pidpropname,
                             sizeof(pidpropname),
                             "dhcp.%s.pid", options->interface) >= PROPERTY_KEY_MAX) {
                    goto abort;
                }
                if (snprintf(pidpropval, sizeof(pidpropval), "%d", getpid()) >= PROPERTY_VALUE_MAX) {
                    goto abort;
                }
		property_set(pidpropname, pidpropval);
#else
		writepid(pid_fd, getpid());
#endif
		logger(LOG_INFO, PACKAGE " " VERSION " starting");
	}

	/* Terminate the encapsulated options */
	if (options->vendor[0]) {
		options->vendor[0]++;
		options->vendor[options->vendor[0]] = DHO_END;
	}

	if (dhcp_run(options, &pid_fd) == 0)
		retval = EXIT_SUCCESS;

abort:
	/* If we didn't daemonise then we need to punt the pidfile now */
	if (pid_fd > -1) {
		close(pid_fd);
		unlink(options->pidfile);
	}
	if (options->environ) {
		len = 0;
		while (options->environ[len])
			free(options->environ[len++]);
		free(options->environ);
	}
	free(options->blacklist);
	free(options);
	exit(retval);
	/* NOTREACHED */
}