src/linux/adjtime.c

   1 #define _GNU_SOURCE
   2 #include <sys/time.h>
   3 #include <sys/timex.h>
   4 #include <errno.h>
   5 #include "syscall.h"
   6
   7 int adjtime(const struct timeval *in, struct timeval *out)
   8 {
   9         struct timex tx = { 0 };
  10         if (in) {
  11                 if (in->tv_sec > 1000 || in->tv_usec > 1000000000) {
  12                         errno = EINVAL;
  13                         return -1;
  14                 }
  15                 tx.offset = in->tv_sec*1000000 + in->tv_usec;
  16                 tx.modes = ADJ_OFFSET_SINGLESHOT;
  17         }
  18         if (syscall(SYS_adjtimex, &tx) < 0) return -1;
  19         if (out) {
  20                 out->tv_sec = tx.offset / 1000000;
  21                 if ((out->tv_usec = tx.offset % 1000000) < 0) {
  22                         out->tv_sec--;
  23                         out->tv_usec += 1000000;
  24                 }
  25         }
  26         return 0;
  27 }