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version 1.1.1.2, 2014/06/15 16:31:38	version 1.1.1.5, 2023/09/27 11:02:07
Line 1	Line 1
/* dnsmasq is Copyright (c) 2000-2014 Simon Kelley	/* dnsmasq is Copyright (c) 2000-2022 Simon Kelley

This program is free software; you can redistribute it and/or modify	This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by	it under the terms of the GNU General Public License as published by
Line 17	Line 17
/* Declare static char compiler_opts in config.h /	/* Declare static char compiler_opts in config.h /
#define DNSMASQ_COMPILE_OPTS	#define DNSMASQ_COMPILE_OPTS

	/* dnsmasq.h has to be included first as it sources config.h */
#include "dnsmasq.h"	#include "dnsmasq.h"

	#if defined(HAVE_IDN) \|\| defined(HAVE_LIBIDN2) \|\| defined(LOCALEDIR)
	#include <locale.h>
	#endif

struct daemon *daemon;	struct daemon *daemon;

static volatile pid_t pid = 0;	static volatile pid_t pid = 0;
static volatile int pipewrite;	static volatile int pipewrite;

static int set_dns_listeners(time_t now, fd_set set, int maxfdp);	static void set_dns_listeners(void);
static void check_dns_listeners(fd_set *set, time_t now);	static void check_dns_listeners(time_t now);
static void sig_handler(int sig);	static void sig_handler(int sig);
static void async_event(int pipe, time_t now);	static void async_event(int pipe, time_t now);
static void fatal_event(struct event_desc ev, char msg);	static void fatal_event(struct event_desc ev, char msg);
static int read_event(int fd, struct event_desc evp, char *msg);	static int read_event(int fd, struct event_desc evp, char *msg);
	static void poll_resolv(int force, int do_reload, time_t now);

int main (int argc, char **argv)	int main (int argc, char **argv)
{	{
int bind_fallback = 0;
time_t now;	time_t now;
struct sigaction sigact;	struct sigaction sigact;
struct iname *if_tmp;	struct iname *if_tmp;
Line 47 int main (int argc, char **argv)	Line 52 int main (int argc, char **argv)
long i, max_fd = sysconf(_SC_OPEN_MAX);	long i, max_fd = sysconf(_SC_OPEN_MAX);
char *baduser = NULL;	char *baduser = NULL;
int log_err;	int log_err;
	int chown_warn = 0;
#if defined(HAVE_LINUX_NETWORK)	#if defined(HAVE_LINUX_NETWORK)
cap_user_header_t hdr = NULL;	cap_user_header_t hdr = NULL;
cap_user_data_t data = NULL;	cap_user_data_t data = NULL;
	int need_cap_net_admin = 0;
	int need_cap_net_raw = 0;
	int need_cap_net_bind_service = 0;
char *bound_device = NULL;	char *bound_device = NULL;
int did_bind = 0;	int did_bind = 0;
	struct server *serv;
	char *netlink_warn;
	#else
	int bind_fallback = 0;
#endif	#endif
#if defined(HAVE_DHCP) \|\| defined(HAVE_DHCP6)	#if defined(HAVE_DHCP) \|\| defined(HAVE_DHCP6)
struct dhcp_context *context;	struct dhcp_context *context;
struct dhcp_relay *relay;	struct dhcp_relay *relay;
#endif	#endif
	#ifdef HAVE_TFTP
	int tftp_prefix_missing = 0;
	#endif

#ifdef LOCALEDIR	#if defined(HAVE_IDN) \|\| defined(HAVE_LIBIDN2) \|\| defined(LOCALEDIR)
setlocale(LC_ALL, "");	setlocale(LC_ALL, "");
	#endif
	#ifdef LOCALEDIR
bindtextdomain("dnsmasq", LOCALEDIR);	bindtextdomain("dnsmasq", LOCALEDIR);
textdomain("dnsmasq");	textdomain("dnsmasq");
#endif	#endif
Line 73 int main (int argc, char **argv)	Line 91 int main (int argc, char **argv)
sigaction(SIGTERM, &sigact, NULL);	sigaction(SIGTERM, &sigact, NULL);
sigaction(SIGALRM, &sigact, NULL);	sigaction(SIGALRM, &sigact, NULL);
sigaction(SIGCHLD, &sigact, NULL);	sigaction(SIGCHLD, &sigact, NULL);
	sigaction(SIGINT, &sigact, NULL);

/* ignore SIGPIPE */	/* ignore SIGPIPE */
sigact.sa_handler = SIG_IGN;	sigact.sa_handler = SIG_IGN;
sigaction(SIGPIPE, &sigact, NULL);	sigaction(SIGPIPE, &sigact, NULL);

umask(022); /* known umask, create leases and pid files as 0644 */	umask(022); /* known umask, create leases and pid files as 0644 */

	rand_init(); /* Must precede read_opts() */

read_opts(argc, argv, compile_opts);	read_opts(argc, argv, compile_opts);

	#ifdef HAVE_LINUX_NETWORK
	daemon->kernel_version = kernel_version();
	#endif

if (daemon->edns_pktsz < PACKETSZ)	if (daemon->edns_pktsz < PACKETSZ)
daemon->edns_pktsz = PACKETSZ;	daemon->edns_pktsz = PACKETSZ;
#ifdef HAVE_DNSSEC
/* Enforce min packet big enough for DNSSEC */
if (option_bool(OPT_DNSSEC_VALID) && daemon->edns_pktsz < EDNS_PKTSZ)
daemon->edns_pktsz = EDNS_PKTSZ;
#endif

daemon->packet_buff_sz = daemon->edns_pktsz > DNSMASQ_PACKETSZ ?	/* Min buffer size: we check after adding each record, so there must be
daemon->edns_pktsz : DNSMASQ_PACKETSZ;	memory for the largest packet, and the largest record so the
	min for DNS is PACKETSZ+MAXDNAME+RRFIXEDSZ which is < 1000.
	This might be increased is EDNS packet size if greater than the minimum. */
	daemon->packet_buff_sz = daemon->edns_pktsz + MAXDNAME + RRFIXEDSZ;
daemon->packet = safe_malloc(daemon->packet_buff_sz);	daemon->packet = safe_malloc(daemon->packet_buff_sz);

daemon->addrbuff = safe_malloc(ADDRSTRLEN);	if (option_bool(OPT_EXTRALOG))
	daemon->addrbuff2 = safe_malloc(ADDRSTRLEN);

#ifdef HAVE_DNSSEC	#ifdef HAVE_DNSSEC
if (option_bool(OPT_DNSSEC_VALID))	if (option_bool(OPT_DNSSEC_VALID))
{	{
daemon->keyname = safe_malloc(MAXDNAME);	/* Note that both /000 and '.' are allowed within labels. These get
daemon->workspacename = safe_malloc(MAXDNAME);	represented in presentation format using NAME_ESCAPE as an escape
	character when in DNSSEC mode.
	In theory, if all the characters in a name were /000 or
	'.' or NAME_ESCAPE then all would have to be escaped, so the
	presentation format would be twice as long as the spec.

	daemon->namebuff was previously allocated by the option-reading
	code before we knew if we're in DNSSEC mode, so reallocate here. */
	free(daemon->namebuff);
	daemon->namebuff = safe_malloc(MAXDNAME * 2);
	daemon->keyname = safe_malloc(MAXDNAME * 2);
	daemon->workspacename = safe_malloc(MAXDNAME * 2);
	/* one char flag per possible RR in answer section (may get extended). */
	daemon->rr_status_sz = 64;
	daemon->rr_status = safe_malloc(sizeof(daemon->rr_status) daemon->rr_status_sz);
}	}
#endif	#endif

	#if defined(HAVE_CONNTRACK) && defined(HAVE_UBUS)
	/* CONNTRACK UBUS code uses this buffer, so if not allocated above,
	we need to allocate it here. */
	if (option_bool(OPT_CMARK_ALST_EN) && !daemon->workspacename)
	daemon->workspacename = safe_malloc(MAXDNAME);
	#endif

#ifdef HAVE_DHCP	#ifdef HAVE_DHCP
if (!daemon->lease_file)	if (!daemon->lease_file)
{	{
Line 112 int main (int argc, char **argv)	Line 157 int main (int argc, char **argv)
}	}
#endif	#endif

/* Close any file descriptors we inherited apart from std{in\|out\|err}	/* Ensure that at least stdin, stdout and stderr (fd 0, 1, 2) exist,

Ensure that at least stdin, stdout and stderr (fd 0, 1, 2) exist,
otherwise file descriptors we create can end up being 0, 1, or 2	otherwise file descriptors we create can end up being 0, 1, or 2
and then get accidentally closed later when we make 0, 1, and 2	and then get accidentally closed later when we make 0, 1, and 2
open to /dev/null. Normally we'll be started with 0, 1 and 2 open,	open to /dev/null. Normally we'll be started with 0, 1 and 2 open,
but it's not guaranteed. By opening /dev/null three times, we	but it's not guaranteed. By opening /dev/null three times, we
ensure that we're not using those fds for real stuff. */	ensure that we're not using those fds for real stuff. */
for (i = 0; i < max_fd; i++)	for (i = 0; i < 3; i++)
if (i != STDOUT_FILENO && i != STDERR_FILENO && i != STDIN_FILENO)	open("/dev/null", O_RDWR);
close(i);
else	/* Close any file descriptors we inherited apart from std{in\|out\|err} */
open("/dev/null", O_RDWR);	close_fds(max_fd, -1, -1, -1);

#ifndef HAVE_LINUX_NETWORK	#ifndef HAVE_LINUX_NETWORK
# if !(defined(IP_RECVDSTADDR) && defined(IP_RECVIF) && defined(IP_SENDSRCADDR))	# if !(defined(IP_RECVDSTADDR) && defined(IP_RECVIF) && defined(IP_SENDSRCADDR))
if (!option_bool(OPT_NOWILD))	if (!option_bool(OPT_NOWILD))
Line 143 int main (int argc, char **argv)	Line 186 int main (int argc, char **argv)
reset_option_bool(OPT_CLEVERBIND);	reset_option_bool(OPT_CLEVERBIND);
}	}
#endif	#endif

	#ifndef HAVE_INOTIFY
	if (daemon->dynamic_dirs)
	die(_("dhcp-hostsdir, dhcp-optsdir and hostsdir are not supported on this platform"), NULL, EC_BADCONF);
	#endif

if (option_bool(OPT_DNSSEC_VALID))	if (option_bool(OPT_DNSSEC_VALID))
{	{
#ifdef HAVE_DNSSEC	#ifdef HAVE_DNSSEC
if (!daemon->ds)	struct ds_config *ds;
die(_("No trust anchors provided for DNSSEC"), NULL, EC_BADCONF);
	/* Must have at least a root trust anchor, or the DNSSEC code
	can loop forever. */
	for (ds = daemon->ds; ds; ds = ds->next)
	if (ds->name[0] == 0)
	break;

	if (!ds)
	die(_("no root trust anchor provided for DNSSEC"), NULL, EC_BADCONF);

if (daemon->cachesize < CACHESIZ)	if (daemon->cachesize < CACHESIZ)
die(_("Cannot reduce cache size from default when DNSSEC enabled"), NULL, EC_BADCONF);	die(_("cannot reduce cache size from default when DNSSEC enabled"), NULL, EC_BADCONF);
#else	#else
die(_("DNSSEC not available: set HAVE_DNSSEC in src/config.h"), NULL, EC_BADCONF);	die(_("DNSSEC not available: set HAVE_DNSSEC in src/config.h"), NULL, EC_BADCONF);
#endif	#endif
Line 163 int main (int argc, char **argv)	Line 219 int main (int argc, char **argv)
#endif	#endif

#ifdef HAVE_CONNTRACK	#ifdef HAVE_CONNTRACK
if (option_bool(OPT_CONNTRACK) && (daemon->query_port != 0 \|\| daemon->osport))	if (option_bool(OPT_CONNTRACK))
die (_("Cannot use --conntrack AND --query-port"), NULL, EC_BADCONF);	{
	if (daemon->query_port != 0 \|\| daemon->osport)
	die (_("cannot use --conntrack AND --query-port"), NULL, EC_BADCONF);

	need_cap_net_admin = 1;
	}
#else	#else
if (option_bool(OPT_CONNTRACK))	if (option_bool(OPT_CONNTRACK))
die(_("Conntrack support not available: set HAVE_CONNTRACK in src/config.h"), NULL, EC_BADCONF);	die(_("conntrack support not available: set HAVE_CONNTRACK in src/config.h"), NULL, EC_BADCONF);
#endif	#endif

#ifdef HAVE_SOLARIS_NETWORK	#ifdef HAVE_SOLARIS_NETWORK
if (daemon->max_logs != 0)	if (daemon->max_logs != 0)
die(_("asychronous logging is not available under Solaris"), NULL, EC_BADCONF);	die(_("asynchronous logging is not available under Solaris"), NULL, EC_BADCONF);
#endif	#endif

#ifdef __ANDROID__	#ifdef __ANDROID__
if (daemon->max_logs != 0)	if (daemon->max_logs != 0)
die(_("asychronous logging is not available under Android"), NULL, EC_BADCONF);	die(_("asynchronous logging is not available under Android"), NULL, EC_BADCONF);
#endif	#endif

#ifndef HAVE_AUTH	#ifndef HAVE_AUTH
if (daemon->authserver)	if (daemon->auth_zones)
die(_("authoritative DNS not available: set HAVE_AUTH in src/config.h"), NULL, EC_BADCONF);	die(_("authoritative DNS not available: set HAVE_AUTH in src/config.h"), NULL, EC_BADCONF);
#endif	#endif

rand_init();	#ifndef HAVE_LOOP
	if (option_bool(OPT_LOOP_DETECT))
	die(_("loop detection not available: set HAVE_LOOP in src/config.h"), NULL, EC_BADCONF);
	#endif

	#ifndef HAVE_UBUS
	if (option_bool(OPT_UBUS))
	die(_("Ubus not available: set HAVE_UBUS in src/config.h"), NULL, EC_BADCONF);
	#endif

	/* Handle only one of min_port/max_port being set. */
	if (daemon->min_port != 0 && daemon->max_port == 0)
	daemon->max_port = MAX_PORT;

	if (daemon->max_port != 0 && daemon->min_port == 0)
	daemon->min_port = MIN_PORT;

	if (daemon->max_port < daemon->min_port)
	die(_("max_port cannot be smaller than min_port"), NULL, EC_BADCONF);

	if (daemon->max_port != 0 &&
	daemon->max_port - daemon->min_port + 1 < daemon->randport_limit)
	die(_("port_limit must not be larger than available port range"), NULL, EC_BADCONF);

now = dnsmasq_time();	now = dnsmasq_time();

/* Create a serial at startup if not configured. */	if (daemon->auth_zones)
if (daemon->authinterface && daemon->soa_sn == 0)	{
	if (!daemon->authserver)
	die(_("--auth-server required when an auth zone is defined."), NULL, EC_BADCONF);

	/* Create a serial at startup if not configured. */
#ifdef HAVE_BROKEN_RTC	#ifdef HAVE_BROKEN_RTC
die(_("zone serial must be configured in --auth-soa"), NULL, EC_BADCONF);	if (daemon->soa_sn == 0)
	die(_("zone serial must be configured in --auth-soa"), NULL, EC_BADCONF);
#else	#else
daemon->soa_sn = now;	if (daemon->soa_sn == 0)
	daemon->soa_sn = now;
#endif	#endif
	}

#ifdef HAVE_DHCP6	#ifdef HAVE_DHCP6
if (daemon->dhcp6)	if (daemon->dhcp6)
Line 220 int main (int argc, char **argv)	Line 310 int main (int argc, char **argv)
/* Note that order matters here, we must call lease_init before	/* Note that order matters here, we must call lease_init before
creating any file descriptors which shouldn't be leaked	creating any file descriptors which shouldn't be leaked
to the lease-script init process. We need to call common_init	to the lease-script init process. We need to call common_init
before lease_init to allocate buffers it uses.*/	before lease_init to allocate buffers it uses.
if (daemon->dhcp \|\| daemon->doing_dhcp6 \|\| daemon->relay4 \|\| daemon->relay6)	The script subsystem relies on DHCP buffers, hence the last two
	conditions below. */
	if (daemon->dhcp \|\| daemon->doing_dhcp6 \|\| daemon->relay4 \|\|
	daemon->relay6 \|\| option_bool(OPT_TFTP) \|\| option_bool(OPT_SCRIPT_ARP))
{	{
dhcp_common_init();	dhcp_common_init();
if (daemon->dhcp \|\| daemon->doing_dhcp6)	if (daemon->dhcp \|\| daemon->doing_dhcp6)
Line 229 int main (int argc, char **argv)	Line 322 int main (int argc, char **argv)
}	}

if (daemon->dhcp \|\| daemon->relay4)	if (daemon->dhcp \|\| daemon->relay4)
dhcp_init();	{
	dhcp_init();
	# ifdef HAVE_LINUX_NETWORK
	if (!option_bool(OPT_NO_PING))
	need_cap_net_raw = 1;
	need_cap_net_admin = 1;
	# endif
	}

# ifdef HAVE_DHCP6	# ifdef HAVE_DHCP6
if (daemon->doing_ra \|\| daemon->doing_dhcp6 \|\| daemon->relay6)	if (daemon->doing_ra \|\| daemon->doing_dhcp6 \|\| daemon->relay6)
ra_init(now);	{
	ra_init(now);
	# ifdef HAVE_LINUX_NETWORK
	need_cap_net_raw = 1;
	need_cap_net_admin = 1;
	# endif
	}

if (daemon->doing_dhcp6 \|\| daemon->relay6)	if (daemon->doing_dhcp6 \|\| daemon->relay6)
dhcp6_init();	dhcp6_init();
Line 243 int main (int argc, char **argv)	Line 349 int main (int argc, char **argv)

#ifdef HAVE_IPSET	#ifdef HAVE_IPSET
if (daemon->ipsets)	if (daemon->ipsets)
ipset_init();	{
	ipset_init();
	# ifdef HAVE_LINUX_NETWORK
	need_cap_net_admin = 1;
	# endif
	}
#endif	#endif

	#ifdef HAVE_NFTSET
	if (daemon->nftsets)
	{
	nftset_init();
	# ifdef HAVE_LINUX_NETWORK
	need_cap_net_admin = 1;
	# endif
	}
	#endif

#if defined(HAVE_LINUX_NETWORK)	#if defined(HAVE_LINUX_NETWORK)
netlink_init();	netlink_warn = netlink_init();
#elif defined(HAVE_BSD_NETWORK)	#elif defined(HAVE_BSD_NETWORK)
route_init();	route_init();
#endif	#endif
Line 270 int main (int argc, char **argv)	Line 391 int main (int argc, char **argv)
#if defined(HAVE_LINUX_NETWORK) && defined(HAVE_DHCP)	#if defined(HAVE_LINUX_NETWORK) && defined(HAVE_DHCP)
/* after enumerate_interfaces() */	/* after enumerate_interfaces() */
bound_device = whichdevice();	bound_device = whichdevice();

if (daemon->dhcp)
{
if (!daemon->relay4 && bound_device)
{
bindtodevice(bound_device, daemon->dhcpfd);
did_bind = 1;
}
if (daemon->enable_pxe && bound_device)
{
bindtodevice(bound_device, daemon->pxefd);
did_bind = 1;
}
}
#endif

#if defined(HAVE_LINUX_NETWORK) && defined(HAVE_DHCP6)	if ((did_bind = bind_dhcp_devices(bound_device)) & 2)
if (daemon->doing_dhcp6 && !daemon->relay6 && bound_device)	die(_("failed to set SO_BINDTODEVICE on DHCP socket: %s"), NULL, EC_BADNET);
{
bindtodevice(bound_device, daemon->dhcp6fd);
did_bind = 1;
}
#endif	#endif
}	}
else	else
Line 309 int main (int argc, char **argv)	Line 411 int main (int argc, char **argv)
if (daemon->port != 0)	if (daemon->port != 0)
{	{
cache_init();	cache_init();
#ifdef HAVE_DNSSEC
blockdata_init();	blockdata_init();
#endif	hash_questions_init();

	/* Scale random socket pool by ftabsize, but
	limit it based on available fds. */
	daemon->numrrand = daemon->ftabsize/2;
	if (daemon->numrrand > max_fd/3)
	daemon->numrrand = max_fd/3;
	/* safe_malloc returns zero'd memory */
	daemon->randomsocks = safe_malloc(daemon->numrrand * sizeof(struct randfd));
}	}

	#ifdef HAVE_INOTIFY
	if ((daemon->port != 0 \|\| daemon->dhcp \|\| daemon->doing_dhcp6)
	&& (!option_bool(OPT_NO_RESOLV) \|\| daemon->dynamic_dirs))
	inotify_dnsmasq_init();
	else
	daemon->inotifyfd = -1;
	#endif

	if (daemon->dump_file)
	#ifdef HAVE_DUMPFILE
	dump_init();
	else
	daemon->dumpfd = -1;
	#else
	die(_("Packet dumps not available: set HAVE_DUMP in src/config.h"), NULL, EC_BADCONF);
	#endif

if (option_bool(OPT_DBUS))	if (option_bool(OPT_DBUS))
#ifdef HAVE_DBUS	#ifdef HAVE_DBUS
{	{
char *err;	char *err;
daemon->dbus = NULL;
daemon->watches = NULL;
if ((err = dbus_init()))	if ((err = dbus_init()))
die(_("DBus error: %s"), err, EC_MISC);	die(_("DBus error: %s"), err, EC_MISC);
}	}
#else	#else
die(_("DBus not available: set HAVE_DBUS in src/config.h"), NULL, EC_BADCONF);	die(_("DBus not available: set HAVE_DBUS in src/config.h"), NULL, EC_BADCONF);
#endif	#endif

	if (option_bool(OPT_UBUS))
	#ifdef HAVE_UBUS
	{
	char *err;
	if ((err = ubus_init()))
	die(_("UBus error: %s"), err, EC_MISC);
	}
	#else
	die(_("UBus not available: set HAVE_UBUS in src/config.h"), NULL, EC_BADCONF);
	#endif

if (daemon->port != 0)	if (daemon->port != 0)
pre_allocate_sfds();	pre_allocate_sfds();

Line 336 int main (int argc, char **argv)	Line 471 int main (int argc, char **argv)
daemon->scriptuser &&	daemon->scriptuser &&
(daemon->lease_change_command \|\| daemon->luascript))	(daemon->lease_change_command \|\| daemon->luascript))
{	{
if ((ent_pw = getpwnam(daemon->scriptuser)))	struct passwd *scr_pw;

	if ((scr_pw = getpwnam(daemon->scriptuser)))
{	{
script_uid = ent_pw->pw_uid;	script_uid = scr_pw->pw_uid;
script_gid = ent_pw->pw_gid;	script_gid = scr_pw->pw_gid;
}	}
else	else
baduser = daemon->scriptuser;	baduser = daemon->scriptuser;
Line 353 int main (int argc, char **argv)	Line 490 int main (int argc, char **argv)

if (baduser)	if (baduser)
die(_("unknown user or group: %s"), baduser, EC_BADCONF);	die(_("unknown user or group: %s"), baduser, EC_BADCONF);

/* implement group defaults, "dip" if available, or group associated with uid */	/* implement group defaults, "dip" if available, or group associated with uid */
if (!daemon->group_set && !gp)	if (!daemon->group_set && !gp)
{	{
Line 366 int main (int argc, char **argv)	Line 503 int main (int argc, char **argv)
}	}

#if defined(HAVE_LINUX_NETWORK)	#if defined(HAVE_LINUX_NETWORK)
	/* We keep CAP_NETADMIN (for ARP-injection) and
	CAP_NET_RAW (for icmp) if we're doing dhcp,
	if we have yet to bind ports because of DAD,
	or we're doing it dynamically, we need CAP_NET_BIND_SERVICE. */
	if ((is_dad_listeners() \|\| option_bool(OPT_CLEVERBIND)) &&
	(option_bool(OPT_TFTP) \|\| (daemon->port != 0 && daemon->port <= 1024)))
	need_cap_net_bind_service = 1;

	/* usptream servers which bind to an interface call SO_BINDTODEVICE
	for each TCP connection, so need CAP_NET_RAW */
	for (serv = daemon->servers; serv; serv = serv->next)
	if (serv->interface[0] != 0)
	need_cap_net_raw = 1;

	/* If we're doing Dbus or UBus, the above can be set dynamically,
	(as can ports) so always (potentially) needed. */
	#ifdef HAVE_DBUS
	if (option_bool(OPT_DBUS))
	{
	need_cap_net_bind_service = 1;
	need_cap_net_raw = 1;
	}
	#endif

	#ifdef HAVE_UBUS
	if (option_bool(OPT_UBUS))
	{
	need_cap_net_bind_service = 1;
	need_cap_net_raw = 1;
	}
	#endif

/* determine capability API version here, while we can still	/* determine capability API version here, while we can still
call safe_malloc */	call safe_malloc */
if (ent_pw && ent_pw->pw_uid != 0)	int capsize = 1; /* for header version 1 */
	char *fail = NULL;

	hdr = safe_malloc(sizeof(*hdr));

	/* find version supported by kernel */
	memset(hdr, 0, sizeof(*hdr));
	capget(hdr, NULL);

	if (hdr->version != LINUX_CAPABILITY_VERSION_1)
{	{
int capsize = 1; /* for header version 1 */	/* if unknown version, use largest supported version (3) */
hdr = safe_malloc(sizeof(*hdr));	if (hdr->version != LINUX_CAPABILITY_VERSION_2)
	hdr->version = LINUX_CAPABILITY_VERSION_3;
/* find version supported by kernel */	capsize = 2;
memset(hdr, 0, sizeof(*hdr));
capget(hdr, NULL);

if (hdr->version != LINUX_CAPABILITY_VERSION_1)
{
/* if unknown version, use largest supported version (3) */
if (hdr->version != LINUX_CAPABILITY_VERSION_2)
hdr->version = LINUX_CAPABILITY_VERSION_3;
capsize = 2;
}

data = safe_malloc(sizeof(data) capsize);
memset(data, 0, sizeof(data) capsize);
}	}

	data = safe_malloc(sizeof(data) capsize);
	capget(hdr, data); /* Get current values, for verification */

	if (need_cap_net_admin && !(data->permitted & (1 << CAP_NET_ADMIN)))
	fail = "NET_ADMIN";
	else if (need_cap_net_raw && !(data->permitted & (1 << CAP_NET_RAW)))
	fail = "NET_RAW";
	else if (need_cap_net_bind_service && !(data->permitted & (1 << CAP_NET_BIND_SERVICE)))
	fail = "NET_BIND_SERVICE";

	if (fail)
	die(_("process is missing required capability %s"), fail, EC_MISC);

	/* Now set bitmaps to set caps after daemonising */
	memset(data, 0, sizeof(data) capsize);

	if (need_cap_net_admin)
	data->effective \|= (1 << CAP_NET_ADMIN);
	if (need_cap_net_raw)
	data->effective \|= (1 << CAP_NET_RAW);
	if (need_cap_net_bind_service)
	data->effective \|= (1 << CAP_NET_BIND_SERVICE);

	data->permitted = data->effective;
#endif	#endif

/* Use a pipe to carry signals and other events back to the event loop	/* Use a pipe to carry signals and other events back to the event loop
Line 409 int main (int argc, char **argv)	Line 599 int main (int argc, char **argv)
if (chdir("/") != 0)	if (chdir("/") != 0)
die(_("cannot chdir to filesystem root: %s"), NULL, EC_MISC);	die(_("cannot chdir to filesystem root: %s"), NULL, EC_MISC);

#ifndef NO_FORK
if (!option_bool(OPT_NO_FORK))	if (!option_bool(OPT_NO_FORK))
{	{
pid_t pid;	pid_t pid;
Line 449 int main (int argc, char **argv)	Line 638 int main (int argc, char **argv)
if (pid != 0)	if (pid != 0)
_exit(0);	_exit(0);
}	}
#endif

/* write pidfile _after_ forking ! */	/* write pidfile _after_ forking ! */
if (daemon->runfile)	if (daemon->runfile)
Line 464 int main (int argc, char **argv)	Line 652 int main (int argc, char **argv)
extent that an attacker running as the unprivileged user could replace the pidfile with a	extent that an attacker running as the unprivileged user could replace the pidfile with a
symlink, and have the target of that symlink overwritten as root next time dnsmasq starts.	symlink, and have the target of that symlink overwritten as root next time dnsmasq starts.

The folowing code first deletes any existing file, and then opens it with the O_EXCL flag,	The following code first deletes any existing file, and then opens it with the O_EXCL flag,
ensuring that the open() fails should there be any existing file (because the unlink() failed,	ensuring that the open() fails should there be any existing file (because the unlink() failed,
or an attacker exploited the race between unlink() and open()). This ensures that no symlink	or an attacker exploited the race between unlink() and open()). This ensures that no symlink
attack can succeed.	attack can succeed.
Line 487 int main (int argc, char **argv)	Line 675 int main (int argc, char **argv)
}	}
else	else
{	{
	/* We're still running as root here. Change the ownership of the PID file
	to the user we will be running as. Note that this is not to allow
	us to delete the file, since that depends on the permissions
	of the directory containing the file. That directory will
	need to by owned by the dnsmasq user, and the ownership of the
	file has to match, to keep systemd >273 happy. */
	if (getuid() == 0 && ent_pw && ent_pw->pw_uid != 0 && fchown(fd, ent_pw->pw_uid, ent_pw->pw_gid) == -1)
	chown_warn = errno;

if (!read_write(fd, (unsigned char *)daemon->namebuff, strlen(daemon->namebuff), 0))	if (!read_write(fd, (unsigned char *)daemon->namebuff, strlen(daemon->namebuff), 0))
err = 1;	err = 1;
	else
while (!err && close(fd) == -1)	{
if (!retry_send())	if (close(fd) == -1)
err = 1;	err = 1;
	}
}	}

if (err)	if (err)
Line 509 int main (int argc, char **argv)	Line 707 int main (int argc, char **argv)
{	{
/* open stdout etc to /dev/null */	/* open stdout etc to /dev/null */
int nullfd = open("/dev/null", O_RDWR);	int nullfd = open("/dev/null", O_RDWR);
dup2(nullfd, STDOUT_FILENO);	if (nullfd != -1)
dup2(nullfd, STDERR_FILENO);	{
dup2(nullfd, STDIN_FILENO);	dup2(nullfd, STDOUT_FILENO);
close(nullfd);	dup2(nullfd, STDERR_FILENO);
	dup2(nullfd, STDIN_FILENO);
	close(nullfd);
	}
}	}

/* if we are to run scripts, we need to fork a helper before dropping root. */	/* if we are to run scripts, we need to fork a helper before dropping root. */
daemon->helperfd = -1;	daemon->helperfd = -1;
#ifdef HAVE_SCRIPT	#ifdef HAVE_SCRIPT
if ((daemon->dhcp \|\| daemon->dhcp6) && (daemon->lease_change_command \|\| daemon->luascript))	if ((daemon->dhcp \|\|
daemon->helperfd = create_helper(pipewrite, err_pipe[1], script_uid, script_gid, max_fd);	daemon->dhcp6 \|\|
	daemon->relay6 \|\|
	option_bool(OPT_TFTP) \|\|
	option_bool(OPT_SCRIPT_ARP)) &&
	(daemon->lease_change_command \|\| daemon->luascript))
	daemon->helperfd = create_helper(pipewrite, err_pipe[1], script_uid, script_gid, max_fd);
#endif	#endif

if (!option_bool(OPT_DEBUG) && getuid() == 0)	if (!option_bool(OPT_DEBUG) && getuid() == 0)
Line 527 int main (int argc, char **argv)	Line 733 int main (int argc, char **argv)
int bad_capabilities = 0;	int bad_capabilities = 0;
gid_t dummy;	gid_t dummy;

/* remove all supplimentary groups */	/* remove all supplementary groups */
if (gp &&	if (gp &&
(setgroups(0, &dummy) == -1 \|\|	(setgroups(0, &dummy) == -1 \|\|
setgid(gp->gr_gid) == -1))	setgid(gp->gr_gid) == -1))
Line 539 int main (int argc, char **argv)	Line 745 int main (int argc, char **argv)
if (ent_pw && ent_pw->pw_uid != 0)	if (ent_pw && ent_pw->pw_uid != 0)
{	{
#if defined(HAVE_LINUX_NETWORK)	#if defined(HAVE_LINUX_NETWORK)
/* On linux, we keep CAP_NETADMIN (for ARP-injection) and	/* Need to be able to drop root. */
CAP_NET_RAW (for icmp) if we're doing dhcp. If we have yet to bind	data->effective \|= (1 << CAP_SETUID);
ports because of DAD, or we're doing it dynamically,	data->permitted \|= (1 << CAP_SETUID);
we need CAP_NET_BIND_SERVICE too. */
if (is_dad_listeners() \|\| option_bool(OPT_CLEVERBIND))
data->effective = data->permitted = data->inheritable =
(1 << CAP_NET_ADMIN) \| (1 << CAP_NET_RAW) \|
(1 << CAP_SETUID) \| (1 << CAP_NET_BIND_SERVICE);
else
data->effective = data->permitted = data->inheritable =
(1 << CAP_NET_ADMIN) \| (1 << CAP_NET_RAW) \| (1 << CAP_SETUID);

/* Tell kernel to not clear capabilities when dropping root */	/* Tell kernel to not clear capabilities when dropping root */
if (capset(hdr, data) == -1 \|\| prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1)	if (capset(hdr, data) == -1 \|\| prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1)
bad_capabilities = errno;	bad_capabilities = errno;
Line 591 int main (int argc, char **argv)	Line 788 int main (int argc, char **argv)
}	}

#ifdef HAVE_LINUX_NETWORK	#ifdef HAVE_LINUX_NETWORK
if (is_dad_listeners() \|\| option_bool(OPT_CLEVERBIND))	data->effective &= ~(1 << CAP_SETUID);
data->effective = data->permitted =	data->permitted &= ~(1 << CAP_SETUID);
(1 << CAP_NET_ADMIN) \| (1 << CAP_NET_RAW) \| (1 << CAP_NET_BIND_SERVICE);
else
data->effective = data->permitted =
(1 << CAP_NET_ADMIN) \| (1 << CAP_NET_RAW);
data->inheritable = 0;

/* lose the setuid and setgid capbilities */	/* lose the setuid capability */
if (capset(hdr, data) == -1)	if (capset(hdr, data) == -1)
{	{
send_event(err_pipe[1], EVENT_CAP_ERR, errno, NULL);	send_event(err_pipe[1], EVENT_CAP_ERR, errno, NULL);
Line 611 int main (int argc, char **argv)	Line 803 int main (int argc, char **argv)
}	}

#ifdef HAVE_LINUX_NETWORK	#ifdef HAVE_LINUX_NETWORK
	free(hdr);
	free(data);
if (option_bool(OPT_DEBUG))	if (option_bool(OPT_DEBUG))
prctl(PR_SET_DUMPABLE, 1, 0, 0, 0);	prctl(PR_SET_DUMPABLE, 1, 0, 0, 0);
#endif	#endif

#ifdef HAVE_TFTP	#ifdef HAVE_TFTP
if (option_bool(OPT_TFTP))	if (option_bool(OPT_TFTP))
{	{
DIR *dir;	DIR *dir;
struct tftp_prefix *p;	struct tftp_prefix *p;
Line 625 int main (int argc, char **argv)	Line 819 int main (int argc, char **argv)
{	{
if (!((dir = opendir(daemon->tftp_prefix))))	if (!((dir = opendir(daemon->tftp_prefix))))
{	{
send_event(err_pipe[1], EVENT_TFTP_ERR, errno, daemon->tftp_prefix);	tftp_prefix_missing = 1;
_exit(0);	if (!option_bool(OPT_TFTP_NO_FAIL))
	{
	send_event(err_pipe[1], EVENT_TFTP_ERR, errno, daemon->tftp_prefix);
	_exit(0);
	}
}	}
closedir(dir);	else
	closedir(dir);
}	}

for (p = daemon->if_prefix; p; p = p->next)	for (p = daemon->if_prefix; p; p = p->next)
{	{
	p->missing = 0;
if (!((dir = opendir(p->prefix))))	if (!((dir = opendir(p->prefix))))
{	{
send_event(err_pipe[1], EVENT_TFTP_ERR, errno, p->prefix);	p->missing = 1;
_exit(0);	if (!option_bool(OPT_TFTP_NO_FAIL))
}	{
closedir(dir);	send_event(err_pipe[1], EVENT_TFTP_ERR, errno, p->prefix);
	_exit(0);
	}
	}
	else
	closedir(dir);
}	}
}	}
#endif	#endif

if (daemon->port == 0)	if (daemon->port == 0)
my_syslog(LOG_INFO, _("started, version %s DNS disabled"), VERSION);	my_syslog(LOG_INFO, _("started, version %s DNS disabled"), VERSION);
else if (daemon->cachesize != 0)	else
my_syslog(LOG_INFO, _("started, version %s cachesize %d"), VERSION, daemon->cachesize);	{
else	if (daemon->cachesize != 0)
my_syslog(LOG_INFO, _("started, version %s cache disabled"), VERSION);	{
	my_syslog(LOG_INFO, _("started, version %s cachesize %d"), VERSION, daemon->cachesize);
	if (daemon->cachesize > 10000)
	my_syslog(LOG_WARNING, _("cache size greater than 10000 may cause performance issues, and is unlikely to be useful."));
	}
	else
	my_syslog(LOG_INFO, _("started, version %s cache disabled"), VERSION);

	if (option_bool(OPT_LOCAL_SERVICE))
	my_syslog(LOG_INFO, _("DNS service limited to local subnets"));
	}

my_syslog(LOG_INFO, _("compile time options: %s"), compile_opts);	my_syslog(LOG_INFO, _("compile time options: %s"), compile_opts);

	if (chown_warn != 0)
	my_syslog(LOG_WARNING, "chown of PID file %s failed: %s", daemon->runfile, strerror(chown_warn));

#ifdef HAVE_DBUS	#ifdef HAVE_DBUS
if (option_bool(OPT_DBUS))	if (option_bool(OPT_DBUS))
Line 662 int main (int argc, char **argv)	Line 880 int main (int argc, char **argv)
}	}
#endif	#endif

if (option_bool(OPT_LOCAL_SERVICE))	#ifdef HAVE_UBUS
my_syslog(LOG_INFO, _("DNS service limited to local subnets"));	if (option_bool(OPT_UBUS))
	{
	if (daemon->ubus)
	my_syslog(LOG_INFO, _("UBus support enabled: connected to system bus"));
	else
	my_syslog(LOG_INFO, _("UBus support enabled: bus connection pending"));
	}
	#endif

#ifdef HAVE_DNSSEC	#ifdef HAVE_DNSSEC
if (option_bool(OPT_DNSSEC_VALID))	if (option_bool(OPT_DNSSEC_VALID))
{	{
my_syslog(LOG_INFO, _("DNSSEC validation enabled"));	int rc;
if (option_bool(OPT_DNSSEC_TIME))	struct ds_config *ds;
my_syslog(LOG_INFO, _("DNSSEC signature timestamps not checked until first cache reload"));
	/* Delay creating the timestamp file until here, after we've changed user, so that
	it has the correct owner to allow updating the mtime later.
	This means we have to report fatal errors via the pipe. */
	if ((rc = setup_timestamp()) == -1)
	{
	send_event(err_pipe[1], EVENT_TIME_ERR, errno, daemon->timestamp_file);
	_exit(0);
	}

	if (option_bool(OPT_DNSSEC_IGN_NS))
	my_syslog(LOG_INFO, _("DNSSEC validation enabled but all unsigned answers are trusted"));
	else
	my_syslog(LOG_INFO, _("DNSSEC validation enabled"));

	daemon->dnssec_no_time_check = option_bool(OPT_DNSSEC_TIME);
	if (option_bool(OPT_DNSSEC_TIME) && !daemon->back_to_the_future)
	my_syslog(LOG_INFO, _("DNSSEC signature timestamps not checked until receipt of SIGINT"));

	if (rc == 1)
	my_syslog(LOG_INFO, _("DNSSEC signature timestamps not checked until system time valid"));

	for (ds = daemon->ds; ds; ds = ds->next)
	my_syslog(LOG_INFO, _("configured with trust anchor for %s keytag %u"),
	ds->name[0] == 0 ? "<root>" : ds->name, ds->keytag);
}	}
#endif	#endif

Line 678 int main (int argc, char **argv)	Line 927 int main (int argc, char **argv)
my_syslog(LOG_WARNING, _("warning: failed to change owner of %s: %s"),	my_syslog(LOG_WARNING, _("warning: failed to change owner of %s: %s"),
daemon->log_file, strerror(log_err));	daemon->log_file, strerror(log_err));

	#ifndef HAVE_LINUX_NETWORK
if (bind_fallback)	if (bind_fallback)
my_syslog(LOG_WARNING, _("setting --bind-interfaces option because of OS limitations"));	my_syslog(LOG_WARNING, _("setting --bind-interfaces option because of OS limitations"));
	#endif

if (option_bool(OPT_NOWILD))	if (option_bool(OPT_NOWILD))
warn_bound_listeners();	warn_bound_listeners();
	else if (!option_bool(OPT_CLEVERBIND))
	warn_wild_labels();

warn_int_names();	warn_int_names();

Line 728 int main (int argc, char **argv)	Line 981 int main (int argc, char **argv)
# ifdef HAVE_LINUX_NETWORK	# ifdef HAVE_LINUX_NETWORK
if (did_bind)	if (did_bind)
my_syslog(MS_DHCP \| LOG_INFO, _("DHCP, sockets bound exclusively to interface %s"), bound_device);	my_syslog(MS_DHCP \| LOG_INFO, _("DHCP, sockets bound exclusively to interface %s"), bound_device);

	if (netlink_warn)
	my_syslog(LOG_WARNING, netlink_warn);
# endif	# endif

/* after dhcp_contruct_contexts */	/* after dhcp_construct_contexts */
if (daemon->dhcp \|\| daemon->doing_dhcp6)	if (daemon->dhcp \|\| daemon->doing_dhcp6)
lease_find_interfaces(now);	lease_find_interfaces(now);
#endif	#endif

#ifdef HAVE_TFTP	#ifdef HAVE_TFTP
if (option_bool(OPT_TFTP))	if (option_bool(OPT_TFTP))
{	{
#ifdef FD_SETSIZE	struct tftp_prefix *p;
if (FD_SETSIZE < (unsigned)max_fd)
max_fd = FD_SETSIZE;
#endif

my_syslog(MS_TFTP \| LOG_INFO, "TFTP %s%s %s",	my_syslog(MS_TFTP \| LOG_INFO, "TFTP %s%s %s %s",
daemon->tftp_prefix ? _("root is ") : _("enabled"),	daemon->tftp_prefix ? _("root is ") : _("enabled"),
daemon->tftp_prefix ? daemon->tftp_prefix: "",	daemon->tftp_prefix ? daemon->tftp_prefix : "",
option_bool(OPT_TFTP_SECURE) ? _("secure mode") : "");	option_bool(OPT_TFTP_SECURE) ? _("secure mode") : "",
	option_bool(OPT_SINGLE_PORT) ? _("single port mode") : "");

	if (tftp_prefix_missing)
	my_syslog(MS_TFTP \| LOG_WARNING, _("warning: %s inaccessible"), daemon->tftp_prefix);

	for (p = daemon->if_prefix; p; p = p->next)
	if (p->missing)
	my_syslog(MS_TFTP \| LOG_WARNING, _("warning: TFTP directory %s inaccessible"), p->prefix);

/* This is a guess, it assumes that for small limits,	/* This is a guess, it assumes that for small limits,
disjoint files might be served, but for large limits,	disjoint files might be served, but for large limits,
a single file will be sent to may clients (the file only needs	a single file will be sent to may clients (the file only needs
one fd). */	one fd). */

max_fd -= 30; /* use other than TFTP */	max_fd -= 30 + daemon->numrrand; /* use other than TFTP */

if (max_fd < 0)	if (max_fd < 0)
max_fd = 5;	max_fd = 5;
else if (max_fd < 100)	else if (max_fd < 100 && !option_bool(OPT_SINGLE_PORT))
max_fd = max_fd/2;	max_fd = max_fd/2;
else	else
max_fd = max_fd - 20;	max_fd = max_fd - 20;
Line 783 int main (int argc, char **argv)	Line 1044 int main (int argc, char **argv)
close(err_pipe[1]);	close(err_pipe[1]);

if (daemon->port != 0)	if (daemon->port != 0)
check_servers();	check_servers(0);

pid = getpid();	pid = getpid();

	daemon->pipe_to_parent = -1;
	for (i = 0; i < MAX_PROCS; i++)
	daemon->tcp_pipes[i] = -1;

	#ifdef HAVE_INOTIFY
	/* Using inotify, have to select a resolv file at startup */
	poll_resolv(1, 0, now);
	#endif

while (1)	while (1)
{	{
int maxfd = -1;	int timeout = fast_retry(now);
struct timeval t, *tp = NULL;
fd_set rset, wset, eset;

FD_ZERO(&rset);	poll_reset();
FD_ZERO(&wset);
FD_ZERO(&eset);

/* if we are out of resources, find how long we have to wait
for some to come free, we'll loop around then and restart
listening for queries */
if ((t.tv_sec = set_dns_listeners(now, &rset, &maxfd)) != 0)
{
t.tv_usec = 0;
tp = &t;
}

/* Whilst polling for the dbus, or doing a tftp transfer, wake every quarter second */	/* Whilst polling for the dbus, or doing a tftp transfer, wake every quarter second */
if (daemon->tftp_trans \|\|	if ((daemon->tftp_trans \|\| (option_bool(OPT_DBUS) && !daemon->dbus)) &&
(option_bool(OPT_DBUS) && !daemon->dbus))	(timeout == -1 \|\| timeout > 250))
{	timeout = 250;
t.tv_sec = 0;
t.tv_usec = 250000;
tp = &t;
}
/* Wake every second whilst waiting for DAD to complete */	/* Wake every second whilst waiting for DAD to complete */
else if (is_dad_listeners())	else if (is_dad_listeners() &&
{	(timeout == -1 \|\| timeout > 1000))
t.tv_sec = 1;	timeout = 1000;
t.tv_usec = 0;
tp = &t;	set_dns_listeners();
}

#ifdef HAVE_DBUS	#ifdef HAVE_DBUS
set_dbus_listeners(&maxfd, &rset, &wset, &eset);	if (option_bool(OPT_DBUS))
#endif	set_dbus_listeners();
	#endif

	#ifdef HAVE_UBUS
	if (option_bool(OPT_UBUS))
	set_ubus_listeners();
	#endif

#ifdef HAVE_DHCP	#ifdef HAVE_DHCP
if (daemon->dhcp \|\| daemon->relay4)	# if defined(HAVE_LINUX_NETWORK)
	if (bind_dhcp_devices(bound_device) & 2)
{	{
FD_SET(daemon->dhcpfd, &rset);	static int warned = 0;
bump_maxfd(daemon->dhcpfd, &maxfd);	if (!warned)
if (daemon->pxefd != -1)
{	{
FD_SET(daemon->pxefd, &rset);	my_syslog(LOG_ERR, _("error binding DHCP socket to device %s"), bound_device);
bump_maxfd(daemon->pxefd, &maxfd);	warned = 1;
}	}
}	}
	# endif
	if (daemon->dhcp \|\| daemon->relay4)
	{
	poll_listen(daemon->dhcpfd, POLLIN);
	if (daemon->pxefd != -1)
	poll_listen(daemon->pxefd, POLLIN);
	}
#endif	#endif

#ifdef HAVE_DHCP6	#ifdef HAVE_DHCP6
if (daemon->doing_dhcp6 \|\| daemon->relay6)	if (daemon->doing_dhcp6 \|\| daemon->relay6)
{	poll_listen(daemon->dhcp6fd, POLLIN);
FD_SET(daemon->dhcp6fd, &rset);
bump_maxfd(daemon->dhcp6fd, &maxfd);
}

if (daemon->doing_ra)	if (daemon->doing_ra)
{	poll_listen(daemon->icmp6fd, POLLIN);
FD_SET(daemon->icmp6fd, &rset);
bump_maxfd(daemon->icmp6fd, &maxfd);
}
#endif	#endif

	#ifdef HAVE_INOTIFY
	if (daemon->inotifyfd != -1)
	poll_listen(daemon->inotifyfd, POLLIN);
	#endif

#if defined(HAVE_LINUX_NETWORK)	#if defined(HAVE_LINUX_NETWORK)
FD_SET(daemon->netlinkfd, &rset);	poll_listen(daemon->netlinkfd, POLLIN);
bump_maxfd(daemon->netlinkfd, &maxfd);
#elif defined(HAVE_BSD_NETWORK)	#elif defined(HAVE_BSD_NETWORK)
FD_SET(daemon->routefd, &rset);	poll_listen(daemon->routefd, POLLIN);
bump_maxfd(daemon->routefd, &maxfd);
#endif	#endif

	poll_listen(piperead, POLLIN);

FD_SET(piperead, &rset);	#ifdef HAVE_SCRIPT
bump_maxfd(piperead, &maxfd);	# ifdef HAVE_DHCP
	while (helper_buf_empty() && do_script_run(now));
	# endif

#ifdef HAVE_DHCP	/* Refresh cache */
# ifdef HAVE_SCRIPT	if (option_bool(OPT_SCRIPT_ARP))
while (helper_buf_empty() && do_script_run(now));	find_mac(NULL, NULL, 0, now);
	while (helper_buf_empty() && do_arp_script_run());

# ifdef HAVE_TFTP	# ifdef HAVE_TFTP
while (helper_buf_empty() && do_tftp_script_run());	while (helper_buf_empty() && do_tftp_script_run());
# endif	# endif

	# ifdef HAVE_DHCP6
	while (helper_buf_empty() && do_snoop_script_run());
	# endif

if (!helper_buf_empty())	if (!helper_buf_empty())
{	poll_listen(daemon->helperfd, POLLOUT);
FD_SET(daemon->helperfd, &wset);	#else
bump_maxfd(daemon->helperfd, &maxfd);
}
# else
/* need this for other side-effects */	/* need this for other side-effects */
	# ifdef HAVE_DHCP
while (do_script_run(now));	while (do_script_run(now));
	# endif

	while (do_arp_script_run());

# ifdef HAVE_TFTP	# ifdef HAVE_TFTP
while (do_tftp_script_run());	while (do_tftp_script_run());
# endif	# endif

# endif
#endif	#endif


/* must do this just before select(), when we know no	/* must do this just before do_poll(), when we know no
more calls to my_syslog() can occur */	more calls to my_syslog() can occur */
set_log_writer(&wset, &maxfd);	set_log_writer();

if (select(maxfd+1, &rset, &wset, &eset, tp) < 0)	if (do_poll(timeout) < 0)
{	continue;
/* otherwise undefined after error */
FD_ZERO(&rset); FD_ZERO(&wset); FD_ZERO(&eset);
}

now = dnsmasq_time();	now = dnsmasq_time();

check_log_writer(&wset);	check_log_writer(0);

/* prime. */	/* prime. */
enumerate_interfaces(1);	enumerate_interfaces(1);
Line 916 int main (int argc, char **argv)	Line 1186 int main (int argc, char **argv)
}	}

#if defined(HAVE_LINUX_NETWORK)	#if defined(HAVE_LINUX_NETWORK)
if (FD_ISSET(daemon->netlinkfd, &rset))	if (poll_check(daemon->netlinkfd, POLLIN))
netlink_multicast(now);	netlink_multicast();
#elif defined(HAVE_BSD_NETWORK)	#elif defined(HAVE_BSD_NETWORK)
if (FD_ISSET(daemon->routefd, &rset))	if (poll_check(daemon->routefd, POLLIN))
route_sock(now);	route_sock();
#endif	#endif

	#ifdef HAVE_INOTIFY
	if (daemon->inotifyfd != -1 && poll_check(daemon->inotifyfd, POLLIN) && inotify_check(now))
	{
	if (daemon->port != 0 && !option_bool(OPT_NO_POLL))
	poll_resolv(1, 1, now);
	}
	#else
/* Check for changes to resolv files once per second max. */	/* Check for changes to resolv files once per second max. */
/* Don't go silent for long periods if the clock goes backwards. */	/* Don't go silent for long periods if the clock goes backwards. */
if (daemon->last_resolv == 0 \|\|	if (daemon->last_resolv == 0 \|\|
Line 935 int main (int argc, char **argv)	Line 1212 int main (int argc, char **argv)
poll_resolv(0, daemon->last_resolv != 0, now);	poll_resolv(0, daemon->last_resolv != 0, now);
daemon->last_resolv = now;	daemon->last_resolv = now;
}	}
	#endif
if (FD_ISSET(piperead, &rset))
	if (poll_check(piperead, POLLIN))
async_event(piperead, now);	async_event(piperead, now);

#ifdef HAVE_DBUS	#ifdef HAVE_DBUS
/* if we didn't create a DBus connection, retry now. */	/* if we didn't create a DBus connection, retry now. */
if (option_bool(OPT_DBUS) && !daemon->dbus)	if (option_bool(OPT_DBUS))
{	{
char *err;	if (!daemon->dbus)
if ((err = dbus_init()))	{
my_syslog(LOG_WARNING, _("DBus error: %s"), err);	char *err = dbus_init();
if (daemon->dbus)
my_syslog(LOG_INFO, _("connected to system DBus"));	if (daemon->dbus)
	my_syslog(LOG_INFO, _("connected to system DBus"));
	else if (err)
	{
	my_syslog(LOG_ERR, _("DBus error: %s"), err);
	reset_option_bool(OPT_DBUS); /* fatal error, stop trying. */
	}
	}

	check_dbus_listeners();
}	}
check_dbus_listeners(&rset, &wset, &eset);
#endif	#endif

check_dns_listeners(&rset, now);

	#ifdef HAVE_UBUS
	/* if we didn't create a UBus connection, retry now. */
	if (option_bool(OPT_UBUS))
	{
	if (!daemon->ubus)
	{
	char *err = ubus_init();

	if (daemon->ubus)
	my_syslog(LOG_INFO, _("connected to system UBus"));
	else if (err)
	{
	my_syslog(LOG_ERR, _("UBus error: %s"), err);
	reset_option_bool(OPT_UBUS); /* fatal error, stop trying. */
	}
	}

	check_ubus_listeners();
	}
	#endif

	check_dns_listeners(now);

#ifdef HAVE_TFTP	#ifdef HAVE_TFTP
check_tftp_listeners(&rset, now);	check_tftp_listeners(now);
#endif	#endif

#ifdef HAVE_DHCP	#ifdef HAVE_DHCP
if (daemon->dhcp \|\| daemon->relay4)	if (daemon->dhcp \|\| daemon->relay4)
{	{
if (FD_ISSET(daemon->dhcpfd, &rset))	if (poll_check(daemon->dhcpfd, POLLIN))
dhcp_packet(now, 0);	dhcp_packet(now, 0);
if (daemon->pxefd != -1 && FD_ISSET(daemon->pxefd, &rset))	if (daemon->pxefd != -1 && poll_check(daemon->pxefd, POLLIN))
dhcp_packet(now, 1);	dhcp_packet(now, 1);
}	}

#ifdef HAVE_DHCP6	#ifdef HAVE_DHCP6
if ((daemon->doing_dhcp6 \|\| daemon->relay6) && FD_ISSET(daemon->dhcp6fd, &rset))	if ((daemon->doing_dhcp6 \|\| daemon->relay6) && poll_check(daemon->dhcp6fd, POLLIN))
dhcp6_packet(now);	dhcp6_packet(now);

if (daemon->doing_ra && FD_ISSET(daemon->icmp6fd, &rset))	if (daemon->doing_ra && poll_check(daemon->icmp6fd, POLLIN))
icmp6_packet(now);	icmp6_packet(now);
#endif	#endif

# ifdef HAVE_SCRIPT	# ifdef HAVE_SCRIPT
if (daemon->helperfd != -1 && FD_ISSET(daemon->helperfd, &wset))	if (daemon->helperfd != -1 && poll_check(daemon->helperfd, POLLOUT))
helper_write();	helper_write();
# endif	# endif
#endif	#endif
Line 990 static void sig_handler(int sig)	Line 1297 static void sig_handler(int sig)
{	{
/* ignore anything other than TERM during startup	/* ignore anything other than TERM during startup
and in helper proc. (helper ignore TERM too) */	and in helper proc. (helper ignore TERM too) */
if (sig == SIGTERM)	if (sig == SIGTERM \|\| sig == SIGINT)
exit(EC_MISC);	exit(EC_MISC);
}	}
else if (pid != getpid())	else if (pid != getpid())
Line 1016 static void sig_handler(int sig)	Line 1323 static void sig_handler(int sig)
event = EVENT_DUMP;	event = EVENT_DUMP;
else if (sig == SIGUSR2)	else if (sig == SIGUSR2)
event = EVENT_REOPEN;	event = EVENT_REOPEN;
	else if (sig == SIGINT)
	{
	/* Handle SIGINT normally in debug mode, so
	ctrl-c continues to operate. */
	if (option_bool(OPT_DEBUG))
	exit(EC_MISC);
	else
	event = EVENT_TIME;
	}
else	else
return;	return;

Line 1037 void send_alarm(time_t event, time_t now)	Line 1353 void send_alarm(time_t event, time_t now)
}	}
}	}

	void queue_event(int event)
	{
	send_event(pipewrite, event, 0, NULL);
	}

void send_event(int fd, int event, int data, char *msg)	void send_event(int fd, int event, int data, char *msg)
{	{
struct event_desc ev;	struct event_desc ev;
Line 1093 static void fatal_event(struct event_desc ev, char m	Line 1414 static void fatal_event(struct event_desc ev, char m

case EVENT_FORK_ERR:	case EVENT_FORK_ERR:
die(_("cannot fork into background: %s"), NULL, EC_MISC);	die(_("cannot fork into background: %s"), NULL, EC_MISC);

	/* fall through */
case EVENT_PIPE_ERR:	case EVENT_PIPE_ERR:
die(_("failed to create helper: %s"), NULL, EC_MISC);	die(_("failed to create helper: %s"), NULL, EC_MISC);

	/* fall through */
case EVENT_CAP_ERR:	case EVENT_CAP_ERR:
die(_("setting capabilities failed: %s"), NULL, EC_MISC);	die(_("setting capabilities failed: %s"), NULL, EC_MISC);

	/* fall through */
case EVENT_USER_ERR:	case EVENT_USER_ERR:
die(_("failed to change user-id to %s: %s"), msg, EC_MISC);	die(_("failed to change user-id to %s: %s"), msg, EC_MISC);

	/* fall through */
case EVENT_GROUP_ERR:	case EVENT_GROUP_ERR:
die(_("failed to change group-id to %s: %s"), msg, EC_MISC);	die(_("failed to change group-id to %s: %s"), msg, EC_MISC);

	/* fall through */
case EVENT_PIDFILE:	case EVENT_PIDFILE:
die(_("failed to open pidfile %s: %s"), msg, EC_FILE);	die(_("failed to open pidfile %s: %s"), msg, EC_FILE);

	/* fall through */
case EVENT_LOG_ERR:	case EVENT_LOG_ERR:
die(_("cannot open log %s: %s"), msg, EC_FILE);	die(_("cannot open log %s: %s"), msg, EC_FILE);

	/* fall through */
case EVENT_LUA_ERR:	case EVENT_LUA_ERR:
die(_("failed to load Lua script: %s"), msg, EC_MISC);	die(_("failed to load Lua script: %s"), msg, EC_MISC);

	/* fall through */
case EVENT_TFTP_ERR:	case EVENT_TFTP_ERR:
die(_("TFTP directory %s inaccessible: %s"), msg, EC_FILE);	die(_("TFTP directory %s inaccessible: %s"), msg, EC_FILE);

	/* fall through */
	case EVENT_TIME_ERR:
	die(_("cannot create timestamp file %s: %s" ), msg, EC_BADCONF);
}	}
}	}

Line 1134 static void async_event(int pipe, time_t now)	Line 1467 static void async_event(int pipe, time_t now)
switch (ev.event)	switch (ev.event)
{	{
case EVENT_RELOAD:	case EVENT_RELOAD:
#ifdef HAVE_DNSSEC	daemon->soa_sn++; /* Bump zone serial, as it may have changed. */
if (option_bool(OPT_DNSSEC_VALID) && option_bool(OPT_DNSSEC_TIME))
{
my_syslog(LOG_INFO, _("now checking DNSSEC signature timestamps"));
reset_option_bool(OPT_DNSSEC_TIME);
}
#endif
/* fall through */	/* fall through */

case EVENT_INIT:	case EVENT_INIT:
Line 1161 static void async_event(int pipe, time_t now)	Line 1489 static void async_event(int pipe, time_t now)
}	}

if (check)	if (check)
check_servers();	check_servers(0);
}	}

#ifdef HAVE_DHCP	#ifdef HAVE_DHCP
Line 1203 static void async_event(int pipe, time_t now)	Line 1531 static void async_event(int pipe, time_t now)
daemon->tcp_pids[i] = 0;	daemon->tcp_pids[i] = 0;
break;	break;

	#if defined(HAVE_SCRIPT)
case EVENT_KILLED:	case EVENT_KILLED:
my_syslog(LOG_WARNING, _("script process killed by signal %d"), ev.data);	my_syslog(LOG_WARNING, _("script process killed by signal %d"), ev.data);
break;	break;
Line 1216 static void async_event(int pipe, time_t now)	Line 1545 static void async_event(int pipe, time_t now)
daemon->lease_change_command, strerror(ev.data));	daemon->lease_change_command, strerror(ev.data));
break;	break;

	case EVENT_SCRIPT_LOG:
	my_syslog(MS_SCRIPT \| LOG_DEBUG, "%s", msg ? msg : "");
	free(msg);
	msg = NULL;
	break;

/* necessary for fatal errors in helper */	/* necessary for fatal errors in helper */
case EVENT_USER_ERR:	case EVENT_USER_ERR:
case EVENT_DIE:	case EVENT_DIE:
case EVENT_LUA_ERR:	case EVENT_LUA_ERR:
fatal_event(&ev, msg);	fatal_event(&ev, msg);
break;	break;
	#endif

case EVENT_REOPEN:	case EVENT_REOPEN:
/* Note: this may leave TCP-handling processes with the old file still open.	/* Note: this may leave TCP-handling processes with the old file still open.
Line 1230 static void async_event(int pipe, time_t now)	Line 1566 static void async_event(int pipe, time_t now)
if (daemon->log_file != NULL)	if (daemon->log_file != NULL)
log_reopen(daemon->log_file);	log_reopen(daemon->log_file);
break;	break;

	case EVENT_NEWADDR:
	newaddress(now);
	break;

	case EVENT_NEWROUTE:
	resend_query();
	/* Force re-reading resolv file right now, for luck. */
	poll_resolv(0, 1, now);
	break;

	case EVENT_TIME:
	#ifdef HAVE_DNSSEC
	if (daemon->dnssec_no_time_check && option_bool(OPT_DNSSEC_VALID) && option_bool(OPT_DNSSEC_TIME))
	{
	my_syslog(LOG_INFO, _("now checking DNSSEC signature timestamps"));
	daemon->dnssec_no_time_check = 0;
	clear_cache_and_reload(now);
	}
	#endif
	break;

case EVENT_TERM:	case EVENT_TERM:
/* Knock all our children on the head. */	/* Knock all our children on the head. */
Line 1237 static void async_event(int pipe, time_t now)	Line 1594 static void async_event(int pipe, time_t now)
if (daemon->tcp_pids[i] != 0)	if (daemon->tcp_pids[i] != 0)
kill(daemon->tcp_pids[i], SIGALRM);	kill(daemon->tcp_pids[i], SIGALRM);

#if defined(HAVE_SCRIPT)	#if defined(HAVE_SCRIPT) && defined(HAVE_DHCP)
/* handle pending lease transitions */	/* handle pending lease transitions */
if (daemon->helperfd != -1)	if (daemon->helperfd != -1)
{	{
/* block in writes until all done */	/* block in writes until all done */
if ((i = fcntl(daemon->helperfd, F_GETFL)) != -1)	if ((i = fcntl(daemon->helperfd, F_GETFL)) != -1)
fcntl(daemon->helperfd, F_SETFL, i & ~O_NONBLOCK);	while(retry_send(fcntl(daemon->helperfd, F_SETFL, i & ~O_NONBLOCK)));
do {	do {
helper_write();	helper_write();
} while (!helper_buf_empty() \|\| do_script_run(now));	} while (!helper_buf_empty() \|\| do_script_run(now));
Line 1254 static void async_event(int pipe, time_t now)	Line 1611 static void async_event(int pipe, time_t now)
if (daemon->lease_stream)	if (daemon->lease_stream)
fclose(daemon->lease_stream);	fclose(daemon->lease_stream);

	#ifdef HAVE_DNSSEC
	/* update timestamp file on TERM if time is considered valid */
	if (daemon->back_to_the_future)
	{
	if (utimes(daemon->timestamp_file, NULL) == -1)
	my_syslog(LOG_ERR, _("failed to update mtime on %s: %s"), daemon->timestamp_file, strerror(errno));
	}
	#endif

if (daemon->runfile)	if (daemon->runfile)
unlink(daemon->runfile);	unlink(daemon->runfile);

	#ifdef HAVE_DUMPFILE
	if (daemon->dumpfd != -1)
	close(daemon->dumpfd);
	#endif

my_syslog(LOG_INFO, _("exiting on receipt of SIGTERM"));	my_syslog(LOG_INFO, _("exiting on receipt of SIGTERM"));
flush_log();	flush_log();
Line 1263 static void async_event(int pipe, time_t now)	Line 1634 static void async_event(int pipe, time_t now)
}	}
}	}

void poll_resolv(int force, int do_reload, time_t now)	static void poll_resolv(int force, int do_reload, time_t now)
{	{
struct resolvc res, latest;	struct resolvc res, latest;
struct stat statbuf;	struct stat statbuf;
Line 1299 void poll_resolv(int force, int do_reload, time_t now)	Line 1670 void poll_resolv(int force, int do_reload, time_t now)
else	else
{	{
res->logged = 0;	res->logged = 0;
if (force \|\| (statbuf.st_mtime != res->mtime))	if (force \|\| (statbuf.st_mtime != res->mtime \|\| statbuf.st_ino != res->ino))
{	{
res->mtime = statbuf.st_mtime;	res->mtime = statbuf.st_mtime;
	res->ino = statbuf.st_ino;
if (difftime(statbuf.st_mtime, last_change) > 0.0)	if (difftime(statbuf.st_mtime, last_change) > 0.0)
{	{
last_change = statbuf.st_mtime;	last_change = statbuf.st_mtime;
Line 1317 void poll_resolv(int force, int do_reload, time_t now)	Line 1689 void poll_resolv(int force, int do_reload, time_t now)
{	{
my_syslog(LOG_INFO, _("reading %s"), latest->name);	my_syslog(LOG_INFO, _("reading %s"), latest->name);
warned = 0;	warned = 0;
check_servers();	check_servers(0);
if (option_bool(OPT_RELOAD) && do_reload)	if (option_bool(OPT_RELOAD) && do_reload)
clear_cache_and_reload(now);	clear_cache_and_reload(now);
}	}
else	else
{	{
	/* If we're delaying things, we don't call check_servers(), but
	reload_servers() may have deleted some servers, rendering the server_array
	invalid, so just rebuild that here. Once reload_servers() succeeds,
	we call check_servers() above, which calls build_server_array itself. */
	build_server_array();
latest->mtime = 0;	latest->mtime = 0;
if (!warned)	if (!warned)
{	{
Line 1360 void clear_cache_and_reload(time_t now)	Line 1737 void clear_cache_and_reload(time_t now)
#endif	#endif
}	}

static int set_dns_listeners(time_t now, fd_set set, int maxfdp)	static void set_dns_listeners(void)
{	{
struct serverfd *serverfdp;	struct serverfd *serverfdp;
struct listener *listener;	struct listener *listener;
int wait = 0, i;	struct randfd_list *rfl;
	int i;

#ifdef HAVE_TFTP	#ifdef HAVE_TFTP
int tftp = 0;	int tftp = 0;
struct tftp_transfer *transfer;	struct tftp_transfer *transfer;
for (transfer = daemon->tftp_trans; transfer; transfer = transfer->next)	if (!option_bool(OPT_SINGLE_PORT))
{	for (transfer = daemon->tftp_trans; transfer; transfer = transfer->next)
tftp++;	{
FD_SET(transfer->sockfd, set);	tftp++;
bump_maxfd(transfer->sockfd, maxfdp);	poll_listen(transfer->sockfd, POLLIN);
}	}
#endif	#endif

/* will we be able to get memory? */
if (daemon->port != 0)
get_new_frec(now, &wait, 0);

for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next)	for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next)
{	poll_listen(serverfdp->fd, POLLIN);
FD_SET(serverfdp->fd, set);
bump_maxfd(serverfdp->fd, maxfdp);	for (i = 0; i < daemon->numrrand; i++)
}	if (daemon->randomsocks[i].refcount != 0)
	poll_listen(daemon->randomsocks[i].fd, POLLIN);

if (daemon->port != 0 && !daemon->osport)	/* Check overflow random sockets too. */
for (i = 0; i < RANDOM_SOCKS; i++)	for (rfl = daemon->rfl_poll; rfl; rfl = rfl->next)
if (daemon->randomsocks[i].refcount != 0)	poll_listen(rfl->rfd->fd, POLLIN);
{
FD_SET(daemon->randomsocks[i].fd, set);
bump_maxfd(daemon->randomsocks[i].fd, maxfdp);
}

	/* check to see if we have free tcp process slots. */
	for (i = MAX_PROCS - 1; i >= 0; i--)
	if (daemon->tcp_pids[i] == 0 && daemon->tcp_pipes[i] == -1)
	break;

for (listener = daemon->listeners; listener; listener = listener->next)	for (listener = daemon->listeners; listener; listener = listener->next)
{	{
/* only listen for queries if we have resources */	if (listener->fd != -1)
if (listener->fd != -1 && wait == 0)	poll_listen(listener->fd, POLLIN);
{
FD_SET(listener->fd, set);	/* Only listen for TCP connections when a process slot
bump_maxfd(listener->fd, maxfdp);	is available. Death of a child goes through the select loop, so
}	we don't need to explicitly arrange to wake up here,
	we'll be called again when a slot becomes available. */
/* death of a child goes through the select loop, so	if (listener->tcpfd != -1 && i >= 0)
we don't need to explicitly arrange to wake up here */	poll_listen(listener->tcpfd, POLLIN);
if (listener->tcpfd != -1)
for (i = 0; i < MAX_PROCS; i++)
if (daemon->tcp_pids[i] == 0)
{
FD_SET(listener->tcpfd, set);
bump_maxfd(listener->tcpfd, maxfdp);
break;
}

#ifdef HAVE_TFTP	#ifdef HAVE_TFTP
	/* tftp == 0 in single-port mode. */
if (tftp <= daemon->tftp_max && listener->tftpfd != -1)	if (tftp <= daemon->tftp_max && listener->tftpfd != -1)
{	poll_listen(listener->tftpfd, POLLIN);
FD_SET(listener->tftpfd, set);
bump_maxfd(listener->tftpfd, maxfdp);
}
#endif	#endif

}	}

return wait;	if (!option_bool(OPT_DEBUG))
	for (i = 0; i < MAX_PROCS; i++)
	if (daemon->tcp_pipes[i] != -1)
	poll_listen(daemon->tcp_pipes[i], POLLIN);
}	}

static void check_dns_listeners(fd_set *set, time_t now)	static void check_dns_listeners(time_t now)
{	{
struct serverfd *serverfdp;	struct serverfd *serverfdp;
struct listener *listener;	struct listener *listener;
	struct randfd_list *rfl;
int i;	int i;
	int pipefd[2];

for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next)	for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next)
if (FD_ISSET(serverfdp->fd, set))	if (poll_check(serverfdp->fd, POLLIN))
reply_query(serverfdp->fd, serverfdp->source_addr.sa.sa_family, now);	reply_query(serverfdp->fd, now);

if (daemon->port != 0 && !daemon->osport)	for (i = 0; i < daemon->numrrand; i++)
for (i = 0; i < RANDOM_SOCKS; i++)	if (daemon->randomsocks[i].refcount != 0 &&
if (daemon->randomsocks[i].refcount != 0 &&	poll_check(daemon->randomsocks[i].fd, POLLIN))
FD_ISSET(daemon->randomsocks[i].fd, set))	reply_query(daemon->randomsocks[i].fd, now);
reply_query(daemon->randomsocks[i].fd, daemon->randomsocks[i].family, now);
	/* Check overflow random sockets too. */
	for (rfl = daemon->rfl_poll; rfl; rfl = rfl->next)
	if (poll_check(rfl->rfd->fd, POLLIN))
	reply_query(rfl->rfd->fd, now);

	/* Races. The child process can die before we read all of the data from the
	pipe, or vice versa. Therefore send tcp_pids to zero when we wait() the
	process, and tcp_pipes to -1 and close the FD when we read the last
	of the data - indicated by cache_recv_insert returning zero.
	The order of these events is indeterminate, and both are needed
	to free the process slot. Once the child process has gone, poll()
	returns POLLHUP, not POLLIN, so have to check for both here. */
	if (!option_bool(OPT_DEBUG))
	for (i = 0; i < MAX_PROCS; i++)
	if (daemon->tcp_pipes[i] != -1 &&
	poll_check(daemon->tcp_pipes[i], POLLIN \| POLLHUP) &&
	!cache_recv_insert(now, daemon->tcp_pipes[i]))
	{
	close(daemon->tcp_pipes[i]);
	daemon->tcp_pipes[i] = -1;
	}

for (listener = daemon->listeners; listener; listener = listener->next)	for (listener = daemon->listeners; listener; listener = listener->next)
{	{
if (listener->fd != -1 && FD_ISSET(listener->fd, set))	if (listener->fd != -1 && poll_check(listener->fd, POLLIN))
receive_query(listener, now);	receive_query(listener, now);

#ifdef HAVE_TFTP	#ifdef HAVE_TFTP
if (listener->tftpfd != -1 && FD_ISSET(listener->tftpfd, set))	if (listener->tftpfd != -1 && poll_check(listener->tftpfd, POLLIN))
tftp_request(listener, now);	tftp_request(listener, now);
#endif	#endif

if (listener->tcpfd != -1 && FD_ISSET(listener->tcpfd, set))	/* check to see if we have a free tcp process slot.
	Note that we can't assume that because we had
	at least one a poll() time, that we still do.
	There may be more waiting connections after
	poll() returns then free process slots. */
	for (i = MAX_PROCS - 1; i >= 0; i--)
	if (daemon->tcp_pids[i] == 0 && daemon->tcp_pipes[i] == -1)
	break;

	if (listener->tcpfd != -1 && i >= 0 && poll_check(listener->tcpfd, POLLIN))
{	{
int confd, client_ok = 1;	int confd, client_ok = 1;
struct irec *iface = NULL;	struct irec *iface = NULL;
Line 1497 static void check_dns_listeners(fd_set *set, time_t no	Line 1897 static void check_dns_listeners(fd_set *set, time_t no
if ((if_index = tcp_interface(confd, tcp_addr.sa.sa_family)) != 0 &&	if ((if_index = tcp_interface(confd, tcp_addr.sa.sa_family)) != 0 &&
indextoname(listener->tcpfd, if_index, intr_name))	indextoname(listener->tcpfd, if_index, intr_name))
{	{
struct all_addr addr;	union all_addr addr;
addr.addr.addr4 = tcp_addr.in.sin_addr;
#ifdef HAVE_IPV6
if (tcp_addr.sa.sa_family == AF_INET6)	if (tcp_addr.sa.sa_family == AF_INET6)
addr.addr.addr6 = tcp_addr.in6.sin6_addr;	addr.addr6 = tcp_addr.in6.sin6_addr;
#endif	else
	addr.addr4 = tcp_addr.in.sin_addr;

for (iface = daemon->interfaces; iface; iface = iface->next)	for (iface = daemon->interfaces; iface; iface = iface->next)
if (iface->index == if_index)	if (iface->index == if_index &&
	iface->addr.sa.sa_family == tcp_addr.sa.sa_family)
break;	break;

if (!iface && !loopback_exception(listener->tcpfd, tcp_addr.sa.sa_family, &addr, intr_name))	if (!iface && !loopback_exception(listener->tcpfd, tcp_addr.sa.sa_family, &addr, intr_name))
Line 1536 static void check_dns_listeners(fd_set *set, time_t no	Line 1937 static void check_dns_listeners(fd_set *set, time_t no
shutdown(confd, SHUT_RDWR);	shutdown(confd, SHUT_RDWR);
close(confd);	close(confd);
}	}
#ifndef NO_FORK	else if (!option_bool(OPT_DEBUG) && pipe(pipefd) == 0 && (p = fork()) != 0)
else if (!option_bool(OPT_DEBUG) && (p = fork()) != 0)
{	{
if (p != -1)	close(pipefd[1]); /* parent needs read pipe end. */
	if (p == -1)
	close(pipefd[0]);
	else
{	{
int i;	#ifdef HAVE_LINUX_NETWORK
for (i = 0; i < MAX_PROCS; i++)	/* The child process inherits the netlink socket,
if (daemon->tcp_pids[i] == 0)	which it never uses, but when the parent (us)
{	uses it in the future, the answer may go to the
daemon->tcp_pids[i] = p;	child, resulting in the parent blocking
break;	forever awaiting the result. To avoid this
}	the child closes the netlink socket, but there's
	a nasty race, since the parent may use netlink
	before the child has done the close.

	To avoid this, the parent blocks here until a
	single byte comes back up the pipe, which
	is sent by the child after it has closed the
	netlink socket. */

	unsigned char a;
	read_write(pipefd[0], &a, 1, 1);
	#endif

	/* i holds index of free slot */
	daemon->tcp_pids[i] = p;
	daemon->tcp_pipes[i] = pipefd[0];
}	}
close(confd);	close(confd);

	/* The child can use up to TCP_MAX_QUERIES ids, so skip that many. */
	daemon->log_id += TCP_MAX_QUERIES;
}	}
#endif
else	else
{	{
unsigned char *buff;	unsigned char *buff;
Line 1559 static void check_dns_listeners(fd_set *set, time_t no	Line 1979 static void check_dns_listeners(fd_set *set, time_t no
int flags;	int flags;
struct in_addr netmask;	struct in_addr netmask;
int auth_dns;	int auth_dns;

if (iface)	if (iface)
{	{
netmask = iface->netmask;	netmask = iface->netmask;
Line 1571 static void check_dns_listeners(fd_set *set, time_t no	Line 1991 static void check_dns_listeners(fd_set *set, time_t no
auth_dns = 0;	auth_dns = 0;
}	}

#ifndef NO_FORK	/* Arrange for SIGALRM after CHILD_LIFETIME seconds to
/* Arrange for SIGALARM after CHILD_LIFETIME seconds to
terminate the process. */	terminate the process. */
if (!option_bool(OPT_DEBUG))	if (!option_bool(OPT_DEBUG))
alarm(CHILD_LIFETIME);	{
#endif	#ifdef HAVE_LINUX_NETWORK
	/* See comment above re: netlink socket. */
	unsigned char a = 0;

	close(daemon->netlinkfd);
	read_write(pipefd[1], &a, 1, 0);
	#endif
	alarm(CHILD_LIFETIME);
	close(pipefd[0]); /* close read end in child. */
	daemon->pipe_to_parent = pipefd[1];
	}

/* start with no upstream connections. */	/* start with no upstream connections. */
for (s = daemon->servers; s; s = s->next)	for (s = daemon->servers; s; s = s->next)
s->tcpfd = -1;	s->tcpfd = -1;
Line 1586 static void check_dns_listeners(fd_set *set, time_t no	Line 2015 static void check_dns_listeners(fd_set *set, time_t no
attribute from the listening socket.	attribute from the listening socket.
Reset that here. */	Reset that here. */
if ((flags = fcntl(confd, F_GETFL, 0)) != -1)	if ((flags = fcntl(confd, F_GETFL, 0)) != -1)
fcntl(confd, F_SETFL, flags & ~O_NONBLOCK);	while(retry_send(fcntl(confd, F_SETFL, flags & ~O_NONBLOCK)));

buff = tcp_request(confd, now, &tcp_addr, netmask, auth_dns);	buff = tcp_request(confd, now, &tcp_addr, netmask, auth_dns);

shutdown(confd, SHUT_RDWR);
close(confd);

if (buff)	if (buff)
free(buff);	free(buff);

Line 1602 static void check_dns_listeners(fd_set *set, time_t no	Line 2028 static void check_dns_listeners(fd_set *set, time_t no
shutdown(s->tcpfd, SHUT_RDWR);	shutdown(s->tcpfd, SHUT_RDWR);
close(s->tcpfd);	close(s->tcpfd);
}	}
#ifndef NO_FORK
if (!option_bool(OPT_DEBUG))	if (!option_bool(OPT_DEBUG))
{	{
	close(daemon->pipe_to_parent);
flush_log();	flush_log();
_exit(0);	_exit(0);
}	}
#endif
}	}
}	}
}	}
Line 1637 int icmp_ping(struct in_addr addr)	Line 2063 int icmp_ping(struct in_addr addr)
{	{
/* Try and get an ICMP echo from a machine. */	/* Try and get an ICMP echo from a machine. */

/* Note that whilst in the three second wait, we check for
(and service) events on the DNS and TFTP sockets, (so doing that
better not use any resources our caller has in use...)
but we remain deaf to signals or further DHCP packets. */

int fd;	int fd;
struct sockaddr_in saddr;	struct sockaddr_in saddr;
struct {	struct {
Line 1651 int icmp_ping(struct in_addr addr)	Line 2072 int icmp_ping(struct in_addr addr)
unsigned short id = rand16();	unsigned short id = rand16();
unsigned int i, j;	unsigned int i, j;
int gotreply = 0;	int gotreply = 0;
time_t start, now;

#if defined(HAVE_LINUX_NETWORK) \|\| defined (HAVE_SOLARIS_NETWORK)	#if defined(HAVE_LINUX_NETWORK) \|\| defined (HAVE_SOLARIS_NETWORK)
if ((fd = make_icmp_sock()) == -1)	if ((fd = make_icmp_sock()) == -1)
Line 1678 int icmp_ping(struct in_addr addr)	Line 2098 int icmp_ping(struct in_addr addr)
j = (j & 0xffff) + (j >> 16);	j = (j & 0xffff) + (j >> 16);
packet.icmp.icmp_cksum = (j == 0xffff) ? j : ~j;	packet.icmp.icmp_cksum = (j == 0xffff) ? j : ~j;

while (sendto(fd, (char *)&packet.icmp, sizeof(struct icmp), 0,	while (retry_send(sendto(fd, (char *)&packet.icmp, sizeof(struct icmp), 0,
(struct sockaddr *)&saddr, sizeof(saddr)) == -1 &&	(struct sockaddr *)&saddr, sizeof(saddr))));
retry_send());

for (now = start = dnsmasq_time();	gotreply = delay_dhcp(dnsmasq_time(), PING_WAIT, fd, addr.s_addr, id);
difftime(now, start) < (float)PING_WAIT;)
	#if defined(HAVE_LINUX_NETWORK) \|\| defined(HAVE_SOLARIS_NETWORK)
	close(fd);
	#else
	opt = 1;
	setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt));
	#endif

	return gotreply;
	}

	int delay_dhcp(time_t start, int sec, int fd, uint32_t addr, unsigned short id)
	{
	/* Delay processing DHCP packets for "sec" seconds counting from "start".
	If "fd" is not -1 it will stop waiting if an ICMP echo reply is received
	from "addr" with ICMP ID "id" and return 1 */

	/* Note that whilst waiting, we check for
	(and service) events on the DNS and TFTP sockets, (so doing that
	better not use any resources our caller has in use...)
	but we remain deaf to signals or further DHCP packets. */

	/* There can be a problem using dnsmasq_time() to end the loop, since
	it's not monotonic, and can go backwards if the system clock is
	tweaked, leading to the code getting stuck in this loop and
	ignoring DHCP requests. To fix this, we check to see if select returned
	as a result of a timeout rather than a socket becoming available. We
	only allow this to happen as many times as it takes to get to the wait time
	in quarter-second chunks. This provides a fallback way to end loop. */

	int rc, timeout_count;
	time_t now;

	for (now = dnsmasq_time(), timeout_count = 0;
	(difftime(now, start) <= (float)sec) && (timeout_count < sec * 4);)
{	{
struct timeval tv;	poll_reset();
fd_set rset, wset;	if (fd != -1)
struct sockaddr_in faddr;	poll_listen(fd, POLLIN);
int maxfd = fd;	set_dns_listeners();
socklen_t len = sizeof(faddr);	set_log_writer();

tv.tv_usec = 250000;
tv.tv_sec = 0;

FD_ZERO(&rset);
FD_ZERO(&wset);
FD_SET(fd, &rset);
set_dns_listeners(now, &rset, &maxfd);
set_log_writer(&wset, &maxfd);

#ifdef HAVE_DHCP6	#ifdef HAVE_DHCP6
if (daemon->doing_ra)	if (daemon->doing_ra)
{	poll_listen(daemon->icmp6fd, POLLIN);
FD_SET(daemon->icmp6fd, &rset);
bump_maxfd(daemon->icmp6fd, &maxfd);
}
#endif	#endif

if (select(maxfd+1, &rset, &wset, NULL, &tv) < 0)	rc = do_poll(250);
{
FD_ZERO(&rset);	if (rc < 0)
FD_ZERO(&wset);	continue;
}	else if (rc == 0)
	timeout_count++;

now = dnsmasq_time();	now = dnsmasq_time();

check_log_writer(&wset);	check_log_writer(0);
check_dns_listeners(&rset, now);	check_dns_listeners(now);

#ifdef HAVE_DHCP6	#ifdef HAVE_DHCP6
if (daemon->doing_ra && FD_ISSET(daemon->icmp6fd, &rset))	if (daemon->doing_ra && poll_check(daemon->icmp6fd, POLLIN))
icmp6_packet(now);	icmp6_packet(now);
#endif	#endif

#ifdef HAVE_TFTP	#ifdef HAVE_TFTP
check_tftp_listeners(&rset, now);	check_tftp_listeners(now);
#endif	#endif

if (FD_ISSET(fd, &rset) &&	if (fd != -1)
recvfrom(fd, &packet, sizeof(packet), 0,	{
(struct sockaddr *)&faddr, &len) == sizeof(packet) &&	struct {
saddr.sin_addr.s_addr == faddr.sin_addr.s_addr &&	struct ip ip;
packet.icmp.icmp_type == ICMP_ECHOREPLY &&	struct icmp icmp;
packet.icmp.icmp_seq == 0 &&	} packet;
packet.icmp.icmp_id == id)	struct sockaddr_in faddr;
{	socklen_t len = sizeof(faddr);
gotreply = 1;
break;	if (poll_check(fd, POLLIN) &&
	recvfrom(fd, &packet, sizeof(packet), 0, (struct sockaddr *)&faddr, &len) == sizeof(packet) &&
	addr == faddr.sin_addr.s_addr &&
	packet.icmp.icmp_type == ICMP_ECHOREPLY &&
	packet.icmp.icmp_seq == 0 &&
	packet.icmp.icmp_id == id)
	return 1;
}	}
}	}

#if defined(HAVE_LINUX_NETWORK) \|\| defined(HAVE_SOLARIS_NETWORK)
close(fd);
#else
opt = 1;
setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt));
#endif

return gotreply;	return 0;
}	}
#endif	#endif /* HAVE_DHCP */

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