ntpd.c

网络时间协议NTP 源码 版本v4.2.0b 该源码用于linux平台下

/*
 * ntpd.c - main program for the fixed point NTP daemon
 */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include "ntp_machine.h"
#include "ntpd.h"
#include "ntp_io.h"
#include "ntp_stdlib.h"
#include <ntp_random.h>

#ifdef SIM
#include "ntpsim.h"
#endif

#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#ifdef HAVE_SYS_STAT_H
# include <sys/stat.h>
#endif
#include <stdio.h>
#ifndef SYS_WINNT
# if !defined(VMS)	/*wjm*/
#  ifdef HAVE_SYS_PARAM_H
#   include <sys/param.h>
#  endif
# endif /* VMS */
# ifdef HAVE_SYS_SIGNAL_H
#  include <sys/signal.h>
# else
#  include <signal.h>
# endif
# ifdef HAVE_SYS_IOCTL_H
#  include <sys/ioctl.h>
# endif /* HAVE_SYS_IOCTL_H */
# ifdef HAVE_SYS_RESOURCE_H
#  include <sys/resource.h>
# endif /* HAVE_SYS_RESOURCE_H */
#else
# include <signal.h>
# include <process.h>
# include <io.h>
# include <clockstuff.h>
#include "ntp_iocompletionport.h"
#endif /* SYS_WINNT */
#if defined(HAVE_RTPRIO)
# ifdef HAVE_SYS_RESOURCE_H
#  include <sys/resource.h>
# endif
# ifdef HAVE_SYS_LOCK_H
#  include <sys/lock.h>
# endif
# include <sys/rtprio.h>
#else
# ifdef HAVE_PLOCK
#  ifdef HAVE_SYS_LOCK_H
#	include <sys/lock.h>
#  endif
# endif
#endif
#if defined(HAVE_SCHED_SETSCHEDULER)
# ifdef HAVE_SCHED_H
#  include <sched.h>
# else
#  ifdef HAVE_SYS_SCHED_H
#   include <sys/sched.h>
#  endif
# endif
#endif
#if defined(HAVE_SYS_MMAN_H)
# include <sys/mman.h>
#endif

#ifdef HAVE_TERMIOS_H
# include <termios.h>
#endif

#ifdef SYS_DOMAINOS
# include <apollo/base.h>
#endif /* SYS_DOMAINOS */

#include "recvbuff.h"  
#include "ntp_cmdargs.h"  

#if 0				/* HMS: I don't think we need this. 961223 */
#ifdef LOCK_PROCESS
# ifdef SYS_SOLARIS
#  include <sys/mman.h>
# else
#  include <sys/lock.h>
# endif
#endif
#endif

#ifdef _AIX
# include <ulimit.h>
#endif /* _AIX */

#ifdef SCO5_CLOCK
# include <sys/ci/ciioctl.h>
#endif

#ifdef HAVE_DROPROOT
# include <ctype.h>
# include <grp.h>
# include <pwd.h>
#ifdef HAVE_LINUX_CAPABILITIES
# include <sys/capability.h>
# include <sys/prctl.h>
#endif
#endif

/*
 * Signals we catch for debugging.	If not debugging we ignore them.
 */
#define MOREDEBUGSIG	SIGUSR1
#define LESSDEBUGSIG	SIGUSR2

/*
 * Signals which terminate us gracefully.
 */
#ifndef SYS_WINNT
# define SIGDIE1 	SIGHUP
# define SIGDIE3 	SIGQUIT
# define SIGDIE2 	SIGINT
# define SIGDIE4 	SIGTERM
#endif /* SYS_WINNT */

#ifdef HAVE_DNSREGISTRATION
#include <dns_sd.h>
DNSServiceRef mdns;
#endif

/*
 * Scheduling priority we run at
 */
#define NTPD_PRIO	(-12)

int priority_done = 2;		/* 0 - Set priority */
				/* 1 - priority is OK where it is */
				/* 2 - Don't set priority */
				/* 1 and 2 are pretty much the same */

/*
 * Debugging flag
 */
volatile int debug;

/*
 * Set the processing not to be in the forground
 */
int forground_process = FALSE;

/*
 * No-fork flag.  If set, we do not become a background daemon.
 */
int nofork;

#ifdef HAVE_DROPROOT
int droproot = 0;
char *user = NULL;		/* User to switch to */
char *group = NULL;		/* group to switch to */
char *chrootdir = NULL;		/* directory to chroot to */
int sw_uid;
int sw_gid;
char *endp;  
struct group *gr;
struct passwd *pw; 
#endif /* HAVE_DROPROOT */

/*
 * Initializing flag.  All async routines watch this and only do their
 * thing when it is clear.
 */
int initializing;

/*
 * Version declaration
 */
extern const char *Version;

int was_alarmed;

#ifdef DECL_SYSCALL
/*
 * We put this here, since the argument profile is syscall-specific
 */
extern int syscall	P((int, ...));
#endif /* DECL_SYSCALL */


#ifdef	SIGDIE2
static	RETSIGTYPE	finish		P((int));
#endif	/* SIGDIE2 */

#ifdef	DEBUG
#ifndef SYS_WINNT
static	RETSIGTYPE	moredebug	P((int));
static	RETSIGTYPE	lessdebug	P((int));
#endif
#else /* not DEBUG */
static	RETSIGTYPE	no_debug	P((int));
#endif	/* not DEBUG */

int 		ntpdmain		P((int, char **));
static void	set_process_priority	P((void));
static void init_logging P((char *));

/*
 * Initialize the logging
 */
void
init_logging(char *name)
{
	char *cp;

	/*
	 * Logging.  This may actually work on the gizmo board.  Find a name
	 * to log with by using the basename
	 */
	cp = strrchr(name, '/');
	if (cp == 0)
		cp = name;
	else
		cp++;

#if !defined(VMS)

# ifndef LOG_DAEMON
	openlog(cp, LOG_PID);
# else /* LOG_DAEMON */

#  ifndef LOG_NTP
#	define	LOG_NTP LOG_DAEMON
#  endif
	openlog(cp, LOG_PID | LOG_NDELAY, LOG_NTP);
#  ifdef DEBUG
	if (debug)
		setlogmask(LOG_UPTO(LOG_DEBUG));
	else
#  endif /* DEBUG */
		setlogmask(LOG_UPTO(LOG_DEBUG)); /* @@@ was INFO */
# endif /* LOG_DAEMON */
#endif	/* !SYS_WINNT && !VMS */

	NLOG(NLOG_SYSINFO) /* conditional if clause for conditional syslog */
		msyslog(LOG_NOTICE, "%s", Version);
}

#ifdef SIM
int
main(
	int argc,
	char *argv[]
	)
{
	return ntpsim(argc, argv);
}
#else /* SIM */
#ifdef NO_MAIN_ALLOWED
CALL(ntpd,"ntpd",ntpdmain);
#else
#ifndef SYS_WINNT
int
main(
	int argc,
	char *argv[]
	)
{
	return ntpdmain(argc, argv);
}
#endif /* SYS_WINNT */
#endif /* NO_MAIN_ALLOWED */
#endif /* SIM */

#ifdef _AIX
/*
 * OK. AIX is different than solaris in how it implements plock().
 * If you do NOT adjust the stack limit, you will get the MAXIMUM
 * stack size allocated and PINNED with you program. To check the 
 * value, use ulimit -a. 
 *
 * To fix this, we create an automatic variable and set our stack limit 
 * to that PLUS 32KB of extra space (we need some headroom).
 *
 * This subroutine gets the stack address.
 *
 * Grover Davidson and Matt Ladendorf
 *
 */
static char *
get_aix_stack(void)
{
	char ch;
	return (&ch);
}

/*
 * Signal handler for SIGDANGER.
 */
static void
catch_danger(int signo)
{
	msyslog(LOG_INFO, "ntpd: setpgid(): %m");
	/* Make the system believe we'll free something, but don't do it! */
	return;
}
#endif /* _AIX */

/*
 * Set the process priority
 */
static void
set_process_priority(void)
{

#ifdef DEBUG
	if (debug > 1)
		msyslog(LOG_DEBUG, "set_process_priority: %s: priority_done is <%d>",
			((priority_done)
			 ? "Leave priority alone"
			 : "Attempt to set priority"
				),
			priority_done);
#endif /* DEBUG */

#ifdef SYS_WINNT
	priority_done += NT_set_process_priority();
#endif

#if defined(HAVE_SCHED_SETSCHEDULER)
	if (!priority_done) {
		extern int config_priority_override, config_priority;
		int pmax, pmin;
		struct sched_param sched;

		pmax = sched_get_priority_max(SCHED_FIFO);
		sched.sched_priority = pmax;
		if ( config_priority_override ) {
			pmin = sched_get_priority_min(SCHED_FIFO);
			if ( config_priority > pmax )
				sched.sched_priority = pmax;
			else if ( config_priority < pmin )
				sched.sched_priority = pmin;
			else
				sched.sched_priority = config_priority;
		}
		if ( sched_setscheduler(0, SCHED_FIFO, &sched) == -1 )
			msyslog(LOG_ERR, "sched_setscheduler(): %m");
		else
			++priority_done;
	}
#endif /* HAVE_SCHED_SETSCHEDULER */
#if defined(HAVE_RTPRIO)
# ifdef RTP_SET
	if (!priority_done) {
		struct rtprio srtp;

		srtp.type = RTP_PRIO_REALTIME;	/* was: RTP_PRIO_NORMAL */
		srtp.prio = 0;		/* 0 (hi) -> RTP_PRIO_MAX (31,lo) */

		if (rtprio(RTP_SET, getpid(), &srtp) < 0)
			msyslog(LOG_ERR, "rtprio() error: %m");
		else
			++priority_done;
	}
# else /* not RTP_SET */
	if (!priority_done) {
		if (rtprio(0, 120) < 0)
			msyslog(LOG_ERR, "rtprio() error: %m");
		else
			++priority_done;
	}
# endif /* not RTP_SET */
#endif  /* HAVE_RTPRIO */
#if defined(NTPD_PRIO) && NTPD_PRIO != 0
# ifdef HAVE_ATT_NICE
	if (!priority_done) {
		errno = 0;
		if (-1 == nice (NTPD_PRIO) && errno != 0)
			msyslog(LOG_ERR, "nice() error: %m");
		else
			++priority_done;
	}
# endif /* HAVE_ATT_NICE */
# ifdef HAVE_BSD_NICE
	if (!priority_done) {
		if (-1 == setpriority(PRIO_PROCESS, 0, NTPD_PRIO))
			msyslog(LOG_ERR, "setpriority() error: %m");
		else
			++priority_done;
	}
# endif /* HAVE_BSD_NICE */
#endif /* NTPD_PRIO && NTPD_PRIO != 0 */
	if (!priority_done)
		msyslog(LOG_ERR, "set_process_priority: No way found to improve our priority");
}


/*
 * Main program.  Initialize us, disconnect us from the tty if necessary,
 * and loop waiting for I/O and/or timer expiries.
 */
int
ntpdmain(
	int argc,
	char *argv[]
	)
{
	l_fp now;
	struct recvbuf *rbuflist;
	struct recvbuf *rbuf;
#ifdef _AIX			/* HMS: ifdef SIGDANGER? */
	struct sigaction sa;
#endif

	initializing = 1;		/* mark that we are initializing */
	debug = 0;			/* no debugging by default */
	nofork = 0;			/* will fork by default */

	init_logging(argv[0]);		/* Open the log file */

#ifdef HAVE_UMASK
	{
		mode_t uv;

		uv = umask(0);
		if(uv)
			(void) umask(uv);
		else
			(void) umask(022);
	}
#endif

#if defined(HAVE_GETUID) && !defined(MPE) /* MPE lacks the concept of root */
	{
		uid_t uid;

		uid = getuid();
		if (uid)
		{
			msyslog(LOG_ERR, "ntpd: must be run as root, not uid %ld", (long)uid);
			exit(1);
		}
	}
#endif

#ifdef OPENSSL
	if ((SSLeay() ^ OPENSSL_VERSION_NUMBER) & ~0xff0L) {
		msyslog(LOG_ERR,
		    "ntpd: OpenSSL version mismatch. Built against %lx, you have %lx\n",
		    OPENSSL_VERSION_NUMBER, SSLeay());
		exit(1);
	}
#endif

#ifdef SYS_WINNT
	/*
	 * Initialize the time structures and variables
	 */
	init_winnt_time();

#endif
	getstartup(argc, argv); /* startup configuration, may set debug */

	if (debug)
	    printf("%s\n", Version);

	/*
	 * Initialize random generator and public key pair
	 */
	get_systime(&now);
	ntp_srandom((int)(now.l_i * now.l_uf));

#ifdef HAVE_DNSREGISTRATION
	msyslog(LOG_INFO, "Attemping to register mDNS\n");
	if ( DNSServiceRegister (&mdns, 0, 0, NULL, "_ntp._udp", NULL, NULL, htons(NTP_PORT), 0, NULL, NULL, NULL) != kDNSServiceErr_NoError ) {
		msyslog(LOG_ERR, "Unable to register mDNS\n");
	}
#endif

#if !defined(VMS)
# ifndef NODETACH
	/*
	 * Detach us from the terminal.  May need an #ifndef GIZMO.
	 */
#  ifdef DEBUG
	if (!debug && !nofork)
#  else /* DEBUG */
	if (!nofork)
#  endif /* DEBUG */
	{
#  ifndef SYS_WINNT
#   ifdef HAVE_DAEMON
		daemon(0, 0);
#   else /* not HAVE_DAEMON */
		if (fork())	/* HMS: What about a -1? */
			exit(0);

		{
#if !defined(F_CLOSEM)
			u_long s;
			int max_fd;
#endif /* not F_CLOSEM */

#if defined(F_CLOSEM)
			/*
			 * From 'Writing Reliable AIX Daemons,' SG24-4946-00,
			 * by Eric Agar (saves us from doing 32767 system
			 * calls)
			 */
			if (fcntl(0, F_CLOSEM, 0) == -1)
			    msyslog(LOG_ERR, "ntpd: failed to close open files(): %m");
#else  /* not F_CLOSEM */

# if defined(HAVE_SYSCONF) && defined(_SC_OPEN_MAX)
			max_fd = sysconf(_SC_OPEN_MAX);
# else /* HAVE_SYSCONF && _SC_OPEN_MAX */
			max_fd = getdtablesize();
# endif /* HAVE_SYSCONF && _SC_OPEN_MAX */
			for (s = 0; s < max_fd; s++)
				(void) close((int)s);
#endif /* not F_CLOSEM */
			(void) open("/", 0);
			(void) dup2(0, 1);
			(void) dup2(0, 2);
#ifdef SYS_DOMAINOS
			{
				uid_$t puid;
				status_$t st;

				proc2_$who_am_i(&puid);