ntpdate.c

网络时间协议NTP 源码 版本v4.2.0b 该源码用于linux平台下

/*
 * ntpdate - set the time of day by polling one or more NTP servers
 */

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

#ifdef HAVE_NETINFO
#include <netinfo/ni.h>
#endif

#include "ntp_machine.h"
#include "ntp_fp.h"
#include "ntp.h"
#include "ntp_io.h"
#include "ntp_unixtime.h"
#include "ntpdate.h"
#include "ntp_string.h"
#include "ntp_syslog.h"
#include "ntp_select.h"
#include "ntp_stdlib.h"

/* Don't include ISC's version of IPv6 variables and structures */
#define ISC_IPV6_H 1
#include "isc/net.h"
#include "isc/result.h"
#include "isc/sockaddr.h"

#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif

#include <stdio.h>
#include <signal.h>
#include <ctype.h>
#ifdef HAVE_POLL_H
# include <poll.h>
#endif
#ifndef SYS_WINNT
# ifdef HAVE_SYS_SIGNAL_H
#  include <sys/signal.h>
# else
#  include <signal.h>
# endif
# ifdef HAVE_SYS_IOCTL_H
#  include <sys/ioctl.h>
# endif
#endif /* SYS_WINNT */
#ifdef HAVE_SYS_RESOURCE_H
# include <sys/resource.h>
#endif /* HAVE_SYS_RESOURCE_H */

#include <arpa/inet.h>

#ifdef __QNXNTO__
# include "adjtime.h"
#endif

#ifdef SYS_VXWORKS
# include "ioLib.h"
# include "sockLib.h"
# include "timers.h"

/* select wants a zero structure ... */
struct timeval timeout = {0,0};
#elif defined(SYS_WINNT)
/*
 * Windows does not abort a select select call if SIGALRM goes off
 * so a 200 ms timeout is needed
 */
struct timeval timeout = {0,1000000/TIMER_HZ};
#else
struct timeval timeout = {60,0};
#endif

#ifdef HAVE_NETINFO
#include <netinfo/ni.h>
#endif

#include "recvbuff.h"

#ifdef SYS_WINNT
#define EPROTONOSUPPORT WSAEPROTONOSUPPORT
#define EAFNOSUPPORT	WSAEAFNOSUPPORT
#define EPFNOSUPPORT	WSAEPFNOSUPPORT
#define TARGET_RESOLUTION 1  /* Try for 1-millisecond accuracy
				on Windows NT timers. */
#pragma comment(lib, "winmm")
isc_boolean_t ntp_port_inuse(int af, u_short port);
#endif /* SYS_WINNT */

/*
 * Scheduling priority we run at
 */
#ifndef SYS_VXWORKS
# define	NTPDATE_PRIO	(-12)
#else
# define	NTPDATE_PRIO	(100)
#endif

#if defined(HAVE_TIMER_SETTIME) || defined (HAVE_TIMER_CREATE)
/* POSIX TIMERS - vxWorks doesn't have itimer - casey */
static timer_t ntpdate_timerid;
#endif

/*
 * Compatibility stuff for Version 2
 */
#define NTP_MAXSKW	0x28f	/* 0.01 sec in fp format */
#define NTP_MINDIST 0x51f	/* 0.02 sec in fp format */
#define PEER_MAXDISP	(64*FP_SECOND)	/* maximum dispersion (fp 64) */
#define NTP_INFIN	15	/* max stratum, infinity a la Bellman-Ford */
#define NTP_MAXWGT	(8*FP_SECOND)	/* maximum select weight 8 seconds */
#define NTP_MAXLIST 5	/* maximum select list size */
#define PEER_SHIFT	8	/* 8 suitable for crystal time base */

/*
 * Debugging flag
 */
volatile int debug = 0;

/*
 * File descriptor masks etc. for call to select
 */

int ai_fam_templ;
int nbsock;
SOCKET fd[MAX_AF];	/* support up to 2 sockets */
int fd_family[MAX_AF];	/* to remember the socket family */
#ifdef HAVE_POLL_H
struct pollfd fdmask[MAX_AF];
#else
fd_set fdmask;
SOCKET maxfd;
#endif
int polltest = 0;

/*
 * Initializing flag.  All async routines watch this and only do their
 * thing when it is clear.
 */
int initializing = 1;

/*
 * Alarm flag.	Set when an alarm occurs
 */
volatile int alarm_flag = 0;

/*
 * Simple query flag.
 */
int simple_query = 0;

/*
 * Unpriviledged port flag.
 */
int unpriv_port = 0;

/*
 * Time to spend measuring drift rate
 */
int rate = 0;

/*
 * Program name.
 */
char *progname;

/*
 * Systemwide parameters and flags
 */
int sys_samples = DEFSAMPLES;	/* number of samples/server */
u_long sys_timeout = DEFTIMEOUT; /* timeout time, in TIMER_HZ units */
struct server *sys_servers;	/* the server list */
int sys_numservers = 0; 	/* number of servers to poll */
int sys_authenticate = 0;	/* true when authenticating */
u_int32 sys_authkey = 0;	/* set to authentication key in use */
u_long sys_authdelay = 0;	/* authentication delay */
int sys_version = NTP_VERSION;	/* version to poll with */

/*
 * The current internal time
 */
u_long current_time = 0;

/*
 * Counter for keeping track of completed servers
 */
int complete_servers = 0;

/*
 * File of encryption keys
 */

#ifndef KEYFILE
# ifndef SYS_WINNT
#define KEYFILE 	"/etc/ntp.keys"
# else
#define KEYFILE 	"%windir%\\ntp.keys"
# endif /* SYS_WINNT */
#endif /* KEYFILE */

#ifndef SYS_WINNT
const char *key_file = KEYFILE;
#else
char key_file_storage[MAX_PATH+1], *key_file ;
#endif	 /* SYS_WINNT */

/*
 * Miscellaneous flags
 */
int verbose = 0;
int always_step = 0;
int never_step = 0;

int 	ntpdatemain P((int, char **));

static	void	transmit	P((struct server *));
static	void	receive 	P((struct recvbuf *));
static	void	server_data P((struct server *, s_fp, l_fp *, u_fp));
static	void	clock_filter	P((struct server *));
static	struct server *clock_select P((void));
static	int clock_adjust	P((void));
static	void	addserver	P((char *));
static	struct server *findserver P((struct sockaddr_storage *));
		void	timer		P((void));
static	void	init_alarm	P((void));
#ifndef SYS_WINNT
static	RETSIGTYPE alarming P((int));
#endif /* SYS_WINNT */
static	void	init_io 	P((void));
static	void	sendpkt 	P((struct sockaddr_storage *, struct pkt *, int));
void	input_handler	P((void));

static	int l_adj_systime	P((l_fp *));
static	int l_step_systime	P((l_fp *));

static	void	printserver P((struct server *, FILE *));

#ifdef SYS_WINNT
int 	on = 1;
WORD	wVersionRequested;
WSADATA wsaData;
HANDLE	TimerThreadHandle = NULL;
#endif /* SYS_WINNT */

#ifdef NO_MAIN_ALLOWED
CALL(ntpdate,"ntpdate",ntpdatemain);

void clear_globals()
{
  /*
   * Debugging flag
   */
  debug = 0;

  ntp_optind = 0;
  /*
   * Initializing flag.  All async routines watch this and only do their
   * thing when it is clear.
   */
  initializing = 1;

  /*
   * Alarm flag.  Set when an alarm occurs
   */
  alarm_flag = 0;

  /*
   * Simple query flag.
   */
  simple_query = 0;

  /*
   * Unpriviledged port flag.
   */
  unpriv_port = 0;

  /*
   * Time to spend measuring drift rate
   */
  rate = 0;
  /*
   * Systemwide parameters and flags
   */
  sys_numservers = 0;	  /* number of servers to poll */
  sys_authenticate = 0;   /* true when authenticating */
  sys_authkey = 0;	   /* set to authentication key in use */
  sys_authdelay = 0;   /* authentication delay */
  sys_version = NTP_VERSION;  /* version to poll with */

  /*
   * The current internal time
   */
  current_time = 0;

  /*
   * Counter for keeping track of completed servers
   */
  complete_servers = 0;
  verbose = 0;
  always_step = 0;
  never_step = 0;
}
#endif

#ifdef HAVE_NETINFO
static ni_namelist *getnetinfoservers P((void));
#endif

/*
 * Main program.  Initialize us and loop waiting for I/O and/or
 * timer expiries.
 */
#ifndef NO_MAIN_ALLOWED
int
main(
	int argc,
	char *argv[]
	)
{
	return ntpdatemain (argc, argv);
}
#endif /* NO_MAIN_ALLOWED */

int
ntpdatemain (
	int argc,
	char *argv[]
	)
{
	int was_alarmed;
	struct recvbuf *rbuflist;
	struct recvbuf *rbuf;
	l_fp tmp;
	int errflg;
	int c;
	int nfound;

#ifdef HAVE_NETINFO
	ni_namelist *netinfoservers;
#endif
#ifdef SYS_WINNT
	HANDLE process_handle;

	wVersionRequested = MAKEWORD(1,1);
	if (WSAStartup(wVersionRequested, &wsaData)) {
		netsyslog(LOG_ERR, "No useable winsock.dll: %m");
		exit(1);
	}

	key_file = key_file_storage;

	if (!ExpandEnvironmentStrings(KEYFILE, key_file, MAX_PATH))
	{
		msyslog(LOG_ERR, "ExpandEnvironmentStrings(KEYFILE) failed: %m\n");
	}
#endif /* SYS_WINNT */

#ifdef NO_MAIN_ALLOWED
	clear_globals();
#endif


	/* Check to see if we have IPv6. Otherwise force the -4 flag */
	if (isc_net_probeipv6() != ISC_R_SUCCESS) {
		ai_fam_templ = AF_INET;
	}

	errflg = 0;
	progname = argv[0];
	syslogit = 0;

	/*
	 * Decode argument list
	 */
	while ((c = ntp_getopt(argc, argv, "46a:bBde:k:o:p:qr:st:uv")) != EOF)
		switch (c)
		{
		case '4':
			ai_fam_templ = AF_INET;
			break;
		case '6':
			ai_fam_templ = AF_INET6;
			break;
		case 'a':
			c = atoi(ntp_optarg);
			sys_authenticate = 1;
			sys_authkey = c;
			break;
		case 'b':
			always_step++;
			never_step = 0;
			break;
		case 'B':
			never_step++;
			always_step = 0;
			break;
		case 'd':
			++debug;
			break;
		case 'e':
			if (!atolfp(ntp_optarg, &tmp)
			|| tmp.l_ui != 0) {
				(void) fprintf(stderr,
					   "%s: encryption delay %s is unlikely\n",
					   progname, ntp_optarg);
				errflg++;
			} else {
				sys_authdelay = tmp.l_uf;
			}
			break;
		case 'k':
			key_file = ntp_optarg;
			break;
		case 'o':
			sys_version = atoi(ntp_optarg);
			break;
		case 'p':
			c = atoi(ntp_optarg);
			if (c <= 0 || c > NTP_SHIFT) {
				(void) fprintf(stderr,
					   "%s: number of samples (%d) is invalid\n",
					   progname, c);
				errflg++;
			} else {
				sys_samples = c;
			}
			break;
		case 'q':
			simple_query = 1;
			break;
		case 'r':
			c = atoi(ntp_optarg);
			if (c <= 0 || c > (60 * 60)) {
				(void) fprintf(stderr,
					   "%s: rate (%d) is invalid: 0 - %d\n",
					   progname, c, (60 * 60));
				errflg++;
			} else {
				rate = c;
			}
			break;
		case 's':
			syslogit = 1;
			break;
		case 't':
			if (!atolfp(ntp_optarg, &tmp)) {
				(void) fprintf(stderr,
					   "%s: timeout %s is undecodeable\n",
					   progname, ntp_optarg);
				errflg++;
			} else {
				sys_timeout = ((LFPTOFP(&tmp) * TIMER_HZ)
					   + 0x8000) >> 16;
				if (sys_timeout == 0)
				sys_timeout = 1;
			}
			break;
		case 'v':
			verbose = 1;
			break;
		case 'u':
			unpriv_port = 1;
			break;
		case '?':
			++errflg;
			break;
		default:
			break;
	    }
	
	if (errflg) {
		(void) fprintf(stderr,
		    "usage: %s [-46bBdqsuv] [-a key#] [-e delay] [-k file] [-p samples] [-o version#] [-r rate] [-t timeo] server ...\n",
		    progname);
		exit(2);
	}

	if (debug || simple_query) {
#ifdef HAVE_SETVBUF
		static char buf[BUFSIZ];
#ifdef SYS_WINNT
		/* Win32 does not implement line bufferibg */
		setvbuf(stdout, NULL, _IONBF, BUFSIZ);
#else
		setvbuf(stdout, buf, _IOLBF, BUFSIZ);
#endif	/* SYS_WINNT */
#else
		setlinebuf(stdout);
#endif
	}

	/*
	 * Logging.  Open the syslog if we have to
	 */
	if (syslogit) {
#if !defined (SYS_WINNT) && !defined (SYS_VXWORKS) && !defined SYS_CYGWIN32
# ifndef	LOG_DAEMON
		openlog("ntpdate", LOG_PID);
# else

#  ifndef	LOG_NTP
#	define	LOG_NTP LOG_DAEMON
#  endif
		openlog("ntpdate", LOG_PID | LOG_NDELAY, LOG_NTP);
		if (debug)
			setlogmask(LOG_UPTO(LOG_DEBUG));
		else
			setlogmask(LOG_UPTO(LOG_INFO));
# endif /* LOG_DAEMON */
#endif	/* SYS_WINNT */
	}

	if (debug || verbose)
		msyslog(LOG_NOTICE, "%s", Version);

	/*
	 * Add servers we are going to be polling
	 */
#ifdef HAVE_NETINFO
	netinfoservers = getnetinfoservers();
#endif

	for ( ; ntp_optind < argc; ntp_optind++)
		addserver(argv[ntp_optind]);

#ifdef HAVE_NETINFO
	if (netinfoservers) {
		if ( netinfoservers->ni_namelist_len &&
		    *netinfoservers->ni_namelist_val ) {
			u_int servercount = 0;
			while (servercount < netinfoservers->ni_namelist_len) {
				if (debug) msyslog(LOG_DEBUG,
						   "Adding time server %s from NetInfo configuration.",
						   netinfoservers->ni_namelist_val[servercount]);
				addserver(netinfoservers->ni_namelist_val[servercount++]);
			}
		}
		ni_namelist_free(netinfoservers);
		free(netinfoservers);
	}
#endif

	if (sys_numservers == 0) {
		msyslog(LOG_ERR, "no servers can be used, exiting");
		exit(1);
	}

	/*
	 * Initialize the time of day routines and the I/O subsystem
	 */
	if (sys_authenticate) {
		init_auth();
		if (!authreadkeys(key_file)) {
			msyslog(LOG_ERR, "no key file <%s>, exiting", key_file);
			exit(1);
		}
		authtrust(sys_authkey, 1);
		if (!authistrusted(sys_authkey)) {
			char buf[10];

			(void) sprintf(buf, "%lu", (unsigned long)sys_authkey);
			msyslog(LOG_ERR, "authentication key %s unknown", buf);
			exit(1);
		}
	}
	init_io();
	init_alarm();

	/*
	 * Set the priority.
	 */
#ifdef SYS_VXWORKS
	taskPrioritySet( taskIdSelf(), NTPDATE_PRIO);
#endif
#if defined(HAVE_ATT_NICE)
	nice (NTPDATE_PRIO);
#endif
#if defined(HAVE_BSD_NICE)
	(void) setpriority(PRIO_PROCESS, 0, NTPDATE_PRIO);
#endif