diff options
Diffstat (limited to 'package/openntpd/src')
-rw-r--r-- | package/openntpd/src/openbsd-compat/port-linux.c | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/package/openntpd/src/openbsd-compat/port-linux.c b/package/openntpd/src/openbsd-compat/port-linux.c new file mode 100644 index 000000000..f210d4a6d --- /dev/null +++ b/package/openntpd/src/openbsd-compat/port-linux.c @@ -0,0 +1,107 @@ +/* $Id: port-linux.c 1793 2007-01-28 20:55:08Z tg $ */ + +/* part of the adjtime-linux patch */ + +/* + * Copyright (c) 2004 Darren Tucker <dtucker at zip com au> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include "includes.h" + +#ifdef USE_ADJTIMEX +#include <sys/timex.h> +#include <errno.h> +#ifdef adjtime +# undef adjtime +#endif + +#include "ntpd.h" + +/* scale factor used by adjtimex freq param. 1 ppm = 65536 */ +#define ADJTIMEX_FREQ_SCALE 65536 + +/* maximum change to skew per adjustment, in PPM */ +#define MAX_SKEW_DELTA 5.0 + +int +_compat_adjtime(const struct timeval *delta, struct timeval *olddelta) +{ + static struct timeval tlast = {0,0}; + static double tskew = 0; + static int synced = -1; + struct timeval tnow, tdelta; + double skew = 0, newskew, deltaskew, adjust, interval = 0; + struct timex tmx; + int result, saved_errno; + + gettimeofday(&tnow, NULL); + adjust = (double)delta->tv_sec; + adjust += (double)delta->tv_usec / 1000000; + + /* Even if the caller doesn't care about the olddelta, we do */ + if (olddelta == NULL) + olddelta = &tdelta; + + result = adjtime(delta, olddelta); + saved_errno = errno; + + if (olddelta->tv_sec == 0 && olddelta->tv_usec == 0 && + synced != INT_MAX) + synced++; + else + synced = 0; + + /* + * do skew calculations if we have synced + */ + if (synced == 0 ) { + tmx.modes = 0; + if (adjtimex(&tmx) == -1) + log_warn("adjtimex get failed"); + else + tskew = (double)tmx.freq / ADJTIMEX_FREQ_SCALE; + } else if (synced >= 1) { + interval = (double)(tnow.tv_sec - tlast.tv_sec); + interval += (double)(tnow.tv_usec - tlast.tv_usec) / 1000000; + + skew = (adjust * 1000000) / interval; + newskew = ((tskew * synced) + skew) / synced; + deltaskew = newskew - tskew; + + if (deltaskew > MAX_SKEW_DELTA) { + log_info("skew change %0.3lf exceeds limit", deltaskew); + tskew += MAX_SKEW_DELTA; + } else if (deltaskew < -MAX_SKEW_DELTA) { + log_info("skew change %0.3lf exceeds limit", deltaskew); + tskew -= MAX_SKEW_DELTA; + } else { + tskew = newskew; + } + + /* Adjust the kernel skew. */ + tmx.freq = (long)(tskew * ADJTIMEX_FREQ_SCALE); + tmx.modes = ADJ_FREQUENCY; + if (adjtimex(&tmx) == -1) + log_warn("adjtimex set freq failed"); + } + + log_debug("interval %0.3lf skew %0.3lf total skew %0.3lf", interval, + skew, tskew); + + tlast = tnow; + errno = saved_errno; + return result; +} +#endif |