Yo Hal! On Thu, 09 Mar 2017 19:46:46 -0800 Hal Murray <hmur...@megapathdsl.net> wrote:
> g...@rellim.com said: > > Yeah, I see that now. But as you pointed out, NTP time is already > > modulo, so it only fails immediately after the rollover. > > > But that rollover is gonna be rough... > > I think it should be clean if/after we get the code right. > > Assume we have 64 bit Unix/POSIX time_t. The only interesting case > is converting NTP time to Unix time. That should work the same way > that GPS week rollover does. You need to figure out via some > out-of-band source what the time is within 68 years. The build time > of of ntpd is one source. The file system is another, but that can > go crazy if you somehow get the time set way in the future. The > operator is another option. Maybe ntpv5 will provide a way. Maybe > one of the sec options. The npd code is gonna be OK, the problem is that the NTP wire protocol for timestamps is in 32 bits! See RFC 5905, Figure 3: NTP Time Formats https://www.ietf.org/rfc/rfc5905.txt > Does the current code have the right variable? Have you found it? > Is there more than one place that does NTP to Unix conversion? Sort of. The conversion constant is JAN_1970. That is defined in include/ntp_calendar.h. There is a macro to do the conversion from timestamp to NTP Epoch: tspec_stamp_to_lfp(), but it is not always used. There look to be just two places the conversion from NTP Epoch is done: ntpcal_ntp_to_time() and ctl_putfs(). And the later not even using l_fp, it uniquely uses tstamp_t which is seconds based on NTP Epoch. Ah, another extern I can change to static... RGDS GARY --------------------------------------------------------------------------- Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703 g...@rellim.com Tel:+1 541 382 8588 Veritas liberabit vos. -- Quid est veritas? "If you can’t measure it, you can’t improve it." - Lord Kelvin
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