tickadj.c

网络时间协议NTP 源码 版本v4.2.0b 该源码用于linux平台下

/*
 * tickadj - read, and possibly modify, the kernel `tick' and
 *	     `tickadj' variables, as well as `dosynctodr'.  Note that
 *	     this operates on the running kernel only.  I'd like to be
 *	     able to read and write the binary as well, but haven't
 *	     mastered this yet.
 *
 * HMS: The #includes here are different from those in xntpd/ntp_unixclock.c
 *      These seem "worse".
 */

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

#include "ntp_types.h"
#include "l_stdlib.h"

#include <stdio.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif /* HAVE_UNISTD_H */

#ifdef HAVE___ADJTIMEX		/* Linux */

#include <sys/timex.h>
struct timex txc;

#if 0
int
main(
	int argc,
	char *argv[]
	)
{
	int     c, i;
	int     quiet = 0;
	int     errflg = 0;
	char    *progname;
	extern int ntp_optind;
	extern char *ntp_optarg;

	progname = argv[0];
	if (argc==2 && argv[1][0] != '-') { /* old Linux format, for compatability */
	    if ((i = atoi(argv[1])) > 0) {
		    txc.time_tick = i;
		    txc.modes = ADJ_TIMETICK;
	    } else {
		    fprintf(stderr, "Silly value for tick: %s\n", argv[1]);
		    errflg++;
	    }
	} else {
	    while ((c = ntp_getopt(argc, argv, "a:qt:")) != EOF) {
		switch (c) {
		    case 'a':
			if ((i=atoi(ntp_optarg)) > 0) {
				txc.tickadj = i;
				txc.modes |= ADJ_TICKADJ;
			} else {
				(void) fprintf(stderr,
				       "%s: unlikely value for tickadj: %s\n",
				       progname, ntp_optarg);
				errflg++;
			}
			break;

		    case 'q':
			quiet = 1;
			break;

		    case 't':
			if ((i=atoi(ntp_optarg)) > 0) {
				txc.time_tick = i;
				txc.modes |= ADJ_TIMETICK;
			} else {
				(void) fprintf(stderr,
				       "%s: unlikely value for tick: %s\n",
				       progname, ntp_optarg);
				errflg++;
			}
			break;

		    default:
			fprintf(stderr,
			    "Usage: %s [tick_value]\n-or-   %s [ -q ] [ -t tick ] [ -a tickadj ]\n",
			    progname, progname);
			errflg++;
			break;
		}
	    }
	}

	if (!errflg) {
		if (__adjtimex(&txc) < 0)
			perror("adjtimex");
		else if (!quiet)
			printf("tick     = %ld\ntick_adj = %d\n",
			    txc.time_tick, txc.tickadj);
	}

	exit(errflg ? 1 : 0);
}
#else
int
main(
	int argc,
	char *argv[]
	)
{
	if (argc > 2)
	{
		fprintf(stderr, "Usage: %s [tick_value]\n", argv[0]);
		exit(-1);
	}
	else if (argc == 2)
	{
#ifdef ADJ_TIMETICK
		if ( (txc.time_tick = atoi(argv[1])) < 1 )
#else
		if ( (txc.tick = atoi(argv[1])) < 1 )
#endif
		{
			fprintf(stderr, "Silly value for tick: %s\n", argv[1]);
			exit(-1);
		}
#ifdef ADJ_TIMETICK
		txc.modes = ADJ_TIMETICK;
#else
#ifdef MOD_OFFSET
		txc.modes = ADJ_TICK;
#else
		txc.mode = ADJ_TICK;
#endif
#endif
	}
	else
	{
#ifdef ADJ_TIMETICK
		txc.modes = 0;
#else
#ifdef MOD_OFFSET
		txc.modes = 0;
#else
		txc.mode = 0;
#endif
#endif
	}
    
	if (__adjtimex(&txc) < 0)
	{
		perror("adjtimex");
	}
	else
	{
#ifdef ADJ_TIMETICK
		printf("tick     = %ld\ntick_adj = %ld\n", txc.time_tick, txc.tickadj);
#else
		printf("tick = %ld\n", txc.tick);
#endif
	}

	exit(0);
}
#endif

#else /* not Linux... kmem tweaking: */

#ifdef HAVE_SYS_FILE_H
# include <sys/file.h>
#endif
#include <sys/stat.h>

#ifdef HAVE_SYS_PARAM_H
# include <sys/param.h>
#endif

#ifdef NLIST_STRUCT
# include <nlist.h>
#else /* not NLIST_STRUCT */ /* was defined(SYS_AUX3) || defined(SYS_AUX2) */
# include <sys/resource.h>
# include <sys/file.h>
# include <a.out.h>
# include <sys/var.h>
#endif

#include "ntp_io.h"
#include "ntp_stdlib.h"

#ifdef hz /* Was: RS6000 */
# undef hz
#endif /* hz */

#ifdef HAVE_KVM_OPEN
# include <kvm.h>
#endif

#ifdef SYS_VXWORKS
/* vxWorks needs mode flag -casey*/
#define open(name, flags)   open(name, flags, 0777)
#endif

#ifndef L_SET	/* Was: defined(SYS_PTX) || defined(SYS_IX86OSF1) */
# define L_SET SEEK_SET
#endif

#ifndef HZ
# define HZ	DEFAULT_HZ
#endif

#define	KMEM	"/dev/kmem"
#define	STREQ(a, b)	(*(a) == *(b) && strcmp((a), (b)) == 0)

char *progname;
volatile int debug;

int dokmem = 1;
int writetickadj = 0;
int writeopttickadj = 0;
int unsetdosync = 0;
int writetick = 0;
int quiet = 0;
int setnoprintf = 0;

const char *kmem = KMEM;
const char *file = NULL;
int   fd  = -1;

static	void	getoffsets	P((off_t *, off_t *, off_t *, off_t *));
static	int	openfile	P((const char *, int));
static	void	writevar	P((int, off_t, int));
static	void	readvar		P((int, off_t, int *));

/*
 * main - parse arguments and handle options
 */
int
main(
	int argc,
	char *argv[]
	)
{
	int c;
	int errflg = 0;
	off_t tickadj_offset;
	off_t tick_offset;
	off_t dosync_offset;
	off_t noprintf_offset;
	int tickadj, ktickadj;	/* HMS: Why isn't this u_long? */
	int tick, ktick;	/* HMS: Why isn't this u_long? */
	int dosynctodr;
	int noprintf;
	int hz;
	int hz_int, hz_hundredths;
	int recommend_tickadj;
	long tmp;

	progname = argv[0];
	while ((c = ntp_getopt(argc, argv, "a:Adkpqst:")) != EOF)
	{
		switch (c)
		{
		    case 'a':
			writetickadj = atoi(ntp_optarg);
			if (writetickadj <= 0)
			{
				(void) fprintf(stderr,
					       "%s: unlikely value for tickadj: %s\n",
					       progname, ntp_optarg);
				errflg++;
			}

#if defined SCO5_CLOCK
			if (writetickadj % HZ) 
			{
				writetickadj = (writetickadj / HZ) * HZ;
				(void) fprintf(stderr,
					       "tickadj truncated to: %d\n", writetickadj);
			}
#endif /* SCO5_CLOCK */

			break;
		    case 'A':
			writeopttickadj = 1;
			break;
		    case 'd':
			++debug;
			break;
		    case 'k':
			dokmem = 1;
			break;
		    case 'p':
			setnoprintf = 1;
			break;
		    case 'q':
			quiet = 1;
			break;
		    case 's':
			unsetdosync = 1;
			break;
		    case 't':
			writetick = atoi(ntp_optarg);
			if (writetick <= 0)
			{
				(void) fprintf(stderr,
					       "%s: unlikely value for tick: %s\n",
					       progname, ntp_optarg);
				errflg++;
			}
			break;
		    default:
			errflg++;
			break;
		}
	}
	if (errflg || ntp_optind != argc)
	{
		(void) fprintf(stderr,
			       "usage: %s [-Adkpqs] [-a newadj] [-t newtick]\n", progname);
		exit(2);
	}

	getoffsets(&tick_offset, &tickadj_offset, &dosync_offset, &noprintf_offset);

	if (debug)
	{
		(void) printf("tick offset = %lu\n", (unsigned long)tick_offset);
		(void) printf("tickadj offset = %lu\n", (unsigned long)tickadj_offset);
		(void) printf("dosynctodr offset = %lu\n", (unsigned long)dosync_offset);
		(void) printf("noprintf offset = %lu\n", (unsigned long)noprintf_offset);
	}

	if (writetick && (tick_offset == 0))
	{
		(void) fprintf(stderr, 
			       "No tick kernel variable\n");
		errflg++;
	}
	
	if (writeopttickadj && (tickadj_offset == 0))
	{
		(void) fprintf(stderr, 
			       "No tickadj kernel variable\n");
		errflg++;
	}

	if (unsetdosync && (dosync_offset == 0))
	{
		(void) fprintf(stderr, 
			       "No dosynctodr kernel variable\n");
		errflg++;
	}
	
	if (setnoprintf && (noprintf_offset == 0))
	{
		(void) fprintf(stderr, 
			       "No noprintf kernel variable\n");
		errflg++;
	}

	if (tick_offset != 0)
	{
		readvar(fd, tick_offset, &tick);
#if defined(TICK_NANO) && defined(K_TICK_NAME)
		if (!quiet)
		    (void) printf("KERNEL %s = %d nsec\n", K_TICK_NAME, tick);
#endif /* TICK_NANO && K_TICK_NAME */

#ifdef TICK_NANO
		tick /= 1000;
#endif
	}
	else
	{
		tick = 0;
	}

	if (tickadj_offset != 0)
	{
		readvar(fd, tickadj_offset, &tickadj);

#ifdef SCO5_CLOCK
		/* scale from nsec/sec to usec/tick */
		tickadj /= (1000L * HZ);
#endif /*SCO5_CLOCK */

#if defined(TICKADJ_NANO) && defined(K_TICKADJ_NAME)
		if (!quiet)
		    (void) printf("KERNEL %s = %d nsec\n", K_TICKADJ_NAME, tickadj);
#endif /* TICKADJ_NANO && K_TICKADJ_NAME */

#ifdef TICKADJ_NANO
		tickadj += 999;
		tickadj /= 1000;
#endif
	}
	else
	{
		tickadj = 0;
	}

	if (dosync_offset != 0)
	{
		readvar(fd, dosync_offset, &dosynctodr);
	}

	if (noprintf_offset != 0)
	{
		readvar(fd, noprintf_offset, &noprintf);
	}

	(void) close(fd);

	if (unsetdosync && dosync_offset == 0)
	{
		(void) fprintf(stderr,
			       "%s: can't find %s in namelist\n",
			       progname,
#ifdef K_DOSYNCTODR_NAME
			       K_DOSYNCTODR_NAME
#else /* not K_DOSYNCTODR_NAME */
			       "dosynctodr"
#endif /* not K_DOSYNCTODR_NAME */
			       );
		exit(1);
	}

	hz = HZ;
#if defined(HAVE_SYSCONF) && defined(_SC_CLK_TCK)
	hz = (int) sysconf (_SC_CLK_TCK);
#endif /* not HAVE_SYSCONF && _SC_CLK_TCK */
#ifdef OVERRIDE_HZ
	hz = DEFAULT_HZ;
#endif
	ktick = tick;
#ifdef PRESET_TICK
	tick = PRESET_TICK;
#endif /* PRESET_TICK */
#ifdef TICKADJ_NANO
	tickadj /= 1000;
	if (tickadj == 0)
	    tickadj = 1;
#endif
	ktickadj = tickadj;
#ifdef PRESET_TICKADJ
	tickadj = (PRESET_TICKADJ) ? PRESET_TICKADJ : 1;
#endif /* PRESET_TICKADJ */

	if (!quiet)
	{
		if (tick_offset != 0)
		{
			(void) printf("KERNEL tick = %d usec (from %s kernel variable)\n",