[systemd-devel] [PATCH] timedated: add LocalTimeUSec via dbus

[Kay Sievers]

On Tue, Mar 24, 2015 at 5:34 AM, Shawn Landden <shawn at churchofgit.com> wrote:
> On Mon, Mar 23, 2015 at 6:52 PM, Zbigniew Jędrzejewski-Szmek
> <zbyszek at in.waw.pl> wrote:
>> On Mon, Mar 23, 2015 at 04:24:38AM -0700, Shawn Landden wrote:
>>> ---
>>>  src/timedate/timedated.c | 24 ++++++++++++++++++++++++
>>>  1 file changed, 24 insertions(+)
>>>
>>> diff --git a/src/timedate/timedated.c b/src/timedate/timedated.c
>>> index ca771d5..f83b99c 100644
>>> --- a/src/timedate/timedated.c
>>> +++ b/src/timedate/timedated.c
>>> @@ -38,6 +38,7 @@
>>>  #include "bus-common-errors.h"
>>>  #include "event-util.h"
>>>  #include "selinux-util.h"
>>> +#include "time-util.h"
>>>
>>>  #define NULL_ADJTIME_UTC "0.0 0 0\n0\nUTC\n"
>>>  #define NULL_ADJTIME_LOCAL "0.0 0 0\n0\nLOCAL\n"
>>> @@ -361,6 +362,28 @@ static int property_get_time(
>>>          return sd_bus_message_append(reply, "t", now(CLOCK_REALTIME));
>>>  }
>>>
>>> +/* gmtime(LocalTimeUSec % USEC_PER_SEC) is useful as long as you ignore GNU
>>> + * extensions of tm_gmtoff and tm_zone, and their ourgrowth in strftime(3)
>>> + */
>>> +static int property_get_local_time(
>>> +                sd_bus *bus,
>>> +                const char *path,
>>> +                const char *interface,
>>> +                const char *property,
>>> +                sd_bus_message *reply,
>>> +                void *userdata,
>>> +                sd_bus_error *error)
>>> +{
>>> +        struct tm tm;
>>> +        struct timespec ts;
>>> +        usec_t t;
>>> +
>>> +        t = now(CLOCK_REALTIME);
>>> +        (void)timespec_store(&ts, t);
>>> +        assert_se(localtime_r(&dummy, &ts.tv_sec));
>>> +        return sd_bus_message_append(reply, "t", t + (tm->tm_gmtoff * USEC_PER_SEC));
>>> +}
>>> +
>>>  static int property_get_ntp_sync(
>>>                  sd_bus *bus,
>>>                  const char *path,
>>> @@ -671,6 +694,7 @@ static const sd_bus_vtable timedate_vtable[] = {
>>>          SD_BUS_PROPERTY("NTP", "b", bus_property_get_bool, offsetof(Context, use_ntp), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
>>>          SD_BUS_PROPERTY("NTPSynchronized", "b", property_get_ntp_sync, 0, 0),
>>>          SD_BUS_PROPERTY("TimeUSec", "t", property_get_time, 0, 0),
>>> +        SD_BUS_PROPERTY("LocalTimeUSec", "t", property_get_local_time, 0, 0),
>>>          SD_BUS_PROPERTY("RTCTimeUSec", "t", property_get_rtc_time, 0, 0),
>>>          SD_BUS_METHOD("SetTime", "xbb", NULL, method_set_time, SD_BUS_VTABLE_UNPRIVILEGED),
>>>          SD_BUS_METHOD("SetTimezone", "sb", NULL, method_set_timezone, SD_BUS_VTABLE_UNPRIVILEGED)
>>
>> This patch seems the most reasonable of the proposed solutions.
>> It answers the question "What does the remote host think local time is?"
>> unambigously.
>>
>> The other patch proposed by Shawn mixes the remote UTC time with local
>> information about timezones, which doesn't seem as clean.
> These are not for the same problem. We need both. I want to ship a
> checksum of the zoneinfo file with the timezone, but its hard to do
> this cleanly as using coreutils from C is a PITA.

Again, systemd is NOT a "remote glibc" API. We are not doing that.

Kay