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Diffstat (limited to 'adjtimed/adjtimed.c')
| -rw-r--r-- | adjtimed/adjtimed.c | 491 |
1 files changed, 491 insertions, 0 deletions
diff --git a/adjtimed/adjtimed.c b/adjtimed/adjtimed.c new file mode 100644 index 0000000..f38e66d --- /dev/null +++ b/adjtimed/adjtimed.c @@ -0,0 +1,491 @@ +/*************************************************************************/ +/* (c) Copyright Tai Jin, 1988. All Rights Reserved. */ +/* Hewlett-Packard Laboratories. */ +/* */ +/* Permission is hereby granted for unlimited modification, use, and */ +/* distribution. This software is made available with no warranty of */ +/* any kind, express or implied. This copyright notice must remain */ +/* intact in all versions of this software. */ +/* */ +/* The author would appreciate it if any bug fixes and enhancements were */ +/* to be sent back to him for incorporation into future versions of this */ +/* software. Please send changes to tai@iag.hp.com or ken@sdd.hp.com. */ +/*************************************************************************/ + +#ifndef lint +static char RCSid[] = "adjtimed.c,v 3.1 1993/07/06 01:04:45 jbj Exp"; +#endif + +/* + * Adjust time daemon. + * This daemon adjusts the rate of the system clock a la BSD's adjtime(). + * The adjtime() routine uses SYSV messages to communicate with this daemon. + * + * Caveat: This emulation uses an undocumented kernel variable. As such, it + * cannot be guaranteed to work in future HP-UX releases. Fortunately, + * it will no longer be needed in HPUX 10.01 and later. + */ + +#include <sys/param.h> +#include <sys/types.h> +#include <sys/ipc.h> +#include <sys/msg.h> +#include <sys/lock.h> +#include <time.h> +#include <signal.h> +#include <nlist.h> +#include <fcntl.h> +#include <stdio.h> +#include <unistd.h> + +#include "ntp_syslog.h" +#include "ntp_stdlib.h" + +#include "adjtime.h" + +double atof (const char *); + +int InitClockRate (void); +int AdjustClockRate (register struct timeval *delta, register struct timeval *olddelta); +long GetClockRate (void); +int SetClockRate (long); +void ResetClockRate (void); +void Cleanup (void); +void Exit (int); + +#define MILLION 1000000L + +/* emacs cc-mode goes nuts if we split the next line... */ +#define tvtod(tv) ((double)tv.tv_sec + ((double)tv.tv_usec / (double)MILLION)) + +char *progname = NULL; +int verbose = 0; +int sysdebug = 0; +static int mqid; +static double oldrate = 0.0; + +int +main( + int argc, + char *argv[] + ) +{ + struct timeval remains; + struct sigvec vec; + MsgBuf msg; + char ch; + int nofork = 0; + int fd; + + progname = argv[0]; + +#ifdef LOG_LOCAL6 + openlog("adjtimed", LOG_PID, LOG_LOCAL6); +#else + openlog("adjtimed", LOG_PID); +#endif + + while ((ch = ntp_getopt(argc, argv, "hkrvdfp:")) != EOF) { + switch (ch) { + case 'k': + case 'r': + if ((mqid = msgget(KEY, 0)) != -1) { + if (msgctl(mqid, IPC_RMID, (struct msqid_ds *)0) == -1) { + msyslog(LOG_ERR, "remove old message queue: %m"); + perror("adjtimed: remove old message queue"); + exit(1); + } + } + + if (ch == 'k') + exit(0); + + break; + + case 'v': + ++verbose, nofork = 1; + break; + + case 'd': + ++sysdebug; + break; + + case 'f': + nofork = 1; + break; + + case 'p': + fputs("adjtimed: -p option ignored\n", stderr); + break; + + default: + puts("usage: adjtimed -hkrvdf"); + puts("-h\thelp"); + puts("-k\tkill existing adjtimed, if any"); + puts("-r\trestart (kills existing adjtimed, if any)"); + puts("-v\tdebug output (repeat for more output)"); + puts("-d\tsyslog output (repeat for more output)"); + puts("-f\tno fork"); + msyslog(LOG_ERR, "usage error"); + exit(1); + } /* switch */ + } /* while */ + + if (!nofork) { + switch (fork()) { + case 0: + close(fileno(stdin)); + close(fileno(stdout)); + close(fileno(stderr)); + +#ifdef TIOCNOTTY + if ((fd = open("/dev/tty")) != -1) { + ioctl(fd, TIOCNOTTY, 0); + close(fd); + } +#else + setpgrp(); +#endif + break; + + case -1: + msyslog(LOG_ERR, "fork: %m"); + perror("adjtimed: fork"); + exit(1); + + default: + exit(0); + } /* switch */ + } /* if */ + + if (nofork) { + setvbuf(stdout, NULL, _IONBF, BUFSIZ); + setvbuf(stderr, NULL, _IONBF, BUFSIZ); + } + + msyslog(LOG_INFO, "started"); + if (verbose) printf("adjtimed: started\n"); + + if (InitClockRate() == -1) + Exit(2); + + (void)signal(SIGHUP, SIG_IGN); + (void)signal(SIGINT, SIG_IGN); + (void)signal(SIGQUIT, SIG_IGN); + (void)signal(SIGTERM, Cleanup); + + vec.sv_handler = ResetClockRate; + vec.sv_flags = 0; + vec.sv_mask = ~0; + sigvector(SIGALRM, &vec, (struct sigvec *)0); + + if (msgget(KEY, IPC_CREAT|IPC_EXCL) == -1) { + if (errno == EEXIST) { + msyslog(LOG_ERR, "message queue already exists, use -r to remove it"); + fputs("adjtimed: message queue already exists, use -r to remove it\n", + stderr); + Exit(1); + } + + msyslog(LOG_ERR, "create message queue: %m"); + perror("adjtimed: create message queue"); + Exit(1); + } + + if ((mqid = msgget(KEY, 0)) == -1) { + msyslog(LOG_ERR, "get message queue id: %m"); + perror("adjtimed: get message queue id"); + Exit(1); + } + + /* Lock process in memory to improve response time */ + if (plock(PROCLOCK)) { + msyslog(LOG_ERR, "plock: %m"); + perror("adjtimed: plock"); + Cleanup(); + } + + /* Also raise process priority. + * If we do not get run when we want, this leads to bad timekeeping + * and "Previous time adjustment didn't complete" gripes from xntpd. + */ + if (nice(-10) == -1) { + msyslog(LOG_ERR, "nice: %m"); + perror("adjtimed: nice"); + Cleanup(); + } + + for (;;) { + if (msgrcv(mqid, &msg.msgp, MSGSIZE, CLIENT, 0) == -1) { + if (errno == EINTR) continue; + msyslog(LOG_ERR, "read message: %m"); + perror("adjtimed: read message"); + Cleanup(); + } + + switch (msg.msgb.code) { + case DELTA1: + case DELTA2: + AdjustClockRate(&msg.msgb.tv, &remains); + + if (msg.msgb.code == DELTA2) { + msg.msgb.tv = remains; + msg.msgb.mtype = SERVER; + + while (msgsnd(mqid, &msg.msgp, MSGSIZE, 0) == -1) { + if (errno == EINTR) continue; + msyslog(LOG_ERR, "send message: %m"); + perror("adjtimed: send message"); + Cleanup(); + } + } + + if (remains.tv_sec + remains.tv_usec != 0L) { + if (verbose) { + printf("adjtimed: previous correction remaining %.6fs\n", + tvtod(remains)); + } + if (sysdebug) { + msyslog(LOG_INFO, "previous correction remaining %.6fs", + tvtod(remains)); + } + } + break; + + default: + fprintf(stderr, "adjtimed: unknown message code %d\n", msg.msgb.code); + msyslog(LOG_ERR, "unknown message code %d", msg.msgb.code); + } /* switch */ + } /* loop */ +} /* main */ + +/* + * Default clock rate (old_tick). + */ +#define DEFAULT_RATE (MILLION / HZ) +#define UNKNOWN_RATE 0L +#define TICK_ADJ 5 /* standard adjustment rate, microsec/tick */ + +static long default_rate = DEFAULT_RATE; +static long tick_rate = HZ; /* ticks per sec */ +static long slew_rate = TICK_ADJ * HZ; /* in microsec/sec */ + +int +AdjustClockRate( + register struct timeval *delta, + register struct timeval *olddelta + ) +{ + register long rate, dt, leftover; + struct itimerval period, remains; + + dt = (delta->tv_sec * MILLION) + delta->tv_usec; + + if (verbose) + printf("adjtimed: new correction %.6fs\n", (double)dt / (double)MILLION); + if (sysdebug) + msyslog(LOG_INFO, "new correction %.6fs", (double)dt / (double)MILLION); + if (verbose > 2) printf("adjtimed: leftover %ldus\n", leftover); + if (sysdebug > 2) msyslog(LOG_INFO, "leftover %ldus", leftover); + rate = dt; + + /* + * Apply a slew rate of slew_rate over a period of dt/slew_rate seconds. + */ + if (dt > 0) { + rate = slew_rate; + } else { + rate = -slew_rate; + dt = -dt; + } + period.it_value.tv_sec = dt / slew_rate; + period.it_value.tv_usec = (dt % slew_rate) * (MILLION / slew_rate); + /* + * Note: we assume the kernel will convert the specified period into ticks + * using the modified clock rate rather than an assumed nominal clock rate, + * and therefore will generate the timer interrupt after the specified + * number of true seconds, not skewed seconds. + */ + + if (verbose > 1) + printf("adjtimed: will be complete in %lds %ldus\n", + period.it_value.tv_sec, period.it_value.tv_usec); + if (sysdebug > 1) + msyslog(LOG_INFO, "will be complete in %lds %ldus", + period.it_value.tv_sec, period.it_value.tv_usec); + /* + * adjust the clock rate + */ + if (dt) { + if (SetClockRate((rate / tick_rate) + default_rate) == -1) { + msyslog(LOG_ERR, "set clock rate: %m"); + perror("adjtimed: set clock rate"); + } + } + /* + * start the timer + * (do this after changing the rate because the period has been rounded down) + */ + period.it_interval.tv_sec = period.it_interval.tv_usec = 0L; + setitimer(ITIMER_REAL, &period, &remains); + /* + * return old delta + */ + if (olddelta) { + dt = ((remains.it_value.tv_sec * MILLION) + remains.it_value.tv_usec) * + oldrate; + olddelta->tv_sec = dt / MILLION; + olddelta->tv_usec = dt - (olddelta->tv_sec * MILLION); + } + + oldrate = (double)rate / (double)MILLION; + return(0); +} /* AdjustClockRate */ + +static struct nlist nl[] = { +#ifdef __hp9000s800 +#ifdef PRE7_0 + { "tick" }, +#else + { "old_tick" }, +#endif +#else + { "_old_tick" }, +#endif + { "" } +}; + +static int kmem; + +/* + * The return value is the clock rate in old_tick units or -1 if error. + */ +long +GetClockRate(void) +{ + long rate, mask; + + if (lseek(kmem, (off_t)nl[0].n_value, 0) == -1L) + return (-1L); + + mask = sigblock(sigmask(SIGALRM)); + + if (read(kmem, (caddr_t)&rate, sizeof(rate)) != sizeof(rate)) + rate = UNKNOWN_RATE; + + sigsetmask(mask); + return (rate); +} /* GetClockRate */ + +/* + * The argument is the new rate in old_tick units. + */ +int +SetClockRate( + long rate + ) +{ + long mask; + + if (lseek(kmem, (off_t)nl[0].n_value, 0) == -1L) + return (-1); + + mask = sigblock(sigmask(SIGALRM)); + + if (write(kmem, (caddr_t)&rate, sizeof(rate)) != sizeof(rate)) { + sigsetmask(mask); + return (-1); + } + + sigsetmask(mask); + + if (rate != default_rate) { + if (verbose > 3) { + printf("adjtimed: clock rate (%lu) %ldus/s\n", rate, + (rate - default_rate) * tick_rate); + } + if (sysdebug > 3) { + msyslog(LOG_INFO, "clock rate (%lu) %ldus/s", rate, + (rate - default_rate) * tick_rate); + } + } + + return (0); +} /* SetClockRate */ + +int +InitClockRate(void) +{ + if ((kmem = open("/dev/kmem", O_RDWR)) == -1) { + msyslog(LOG_ERR, "open(/dev/kmem): %m"); + perror("adjtimed: open(/dev/kmem)"); + return (-1); + } + + nlist("/hp-ux", nl); + + if (nl[0].n_type == 0) { + fputs("adjtimed: /hp-ux has no symbol table\n", stderr); + msyslog(LOG_ERR, "/hp-ux has no symbol table"); + return (-1); + } + /* + * Set the default to the system's original value + */ + default_rate = GetClockRate(); + if (default_rate == UNKNOWN_RATE) default_rate = DEFAULT_RATE; + tick_rate = (MILLION / default_rate); + slew_rate = TICK_ADJ * tick_rate; + fprintf(stderr,"default_rate=%ld, tick_rate=%ld, slew_rate=%ld\n",default_rate,tick_rate,slew_rate); + + return (0); +} /* InitClockRate */ + +/* + * Reset the clock rate to the default value. + */ +void +ResetClockRate(void) +{ + struct itimerval it; + + it.it_value.tv_sec = it.it_value.tv_usec = 0L; + setitimer(ITIMER_REAL, &it, (struct itimerval *)0); + + if (verbose > 2) puts("adjtimed: resetting the clock"); + if (sysdebug > 2) msyslog(LOG_INFO, "resetting the clock"); + + if (GetClockRate() != default_rate) { + if (SetClockRate(default_rate) == -1) { + msyslog(LOG_ERR, "set clock rate: %m"); + perror("adjtimed: set clock rate"); + } + } + + oldrate = 0.0; +} /* ResetClockRate */ + +void +Cleanup(void) +{ + ResetClockRate(); + + if (msgctl(mqid, IPC_RMID, (struct msqid_ds *)0) == -1) { + if (errno != EINVAL) { + msyslog(LOG_ERR, "remove message queue: %m"); + perror("adjtimed: remove message queue"); + } + } + + Exit(2); +} /* Cleanup */ + +void +Exit(status) + int status; +{ + msyslog(LOG_ERR, "terminated"); + closelog(); + if (kmem != -1) close(kmem); + exit(status); +} /* Exit */ |