timedated: when performing "SetTime" compensate for program lag

(David: fix up compile-failure and simplify code a bit)

2 files changed, 10 insertions, 2 deletions

diff --git a/TODO b/TODO
index cb83a3eb2b..ca91b123c7 100644
--- a/TODO
+++ b/TODO
@@ -168,8 +168,6 @@ Features:
 
 * in systemctl list-unit-files: show the install value the presets would suggest for a service in a third column
 
-* timedated should compensate on SetTime for the time spent in polkit
-
 * figure out when we can use the coarse timers
 
 * sd-resolve: drop res_query wrapping, people should call via the bus to resolved instead
diff --git a/src/timedate/timedated.c b/src/timedate/timedated.c
index 18dcd18b00..88d57e9d54 100644
--- a/src/timedate/timedated.c
+++ b/src/timedate/timedated.c
@@ -540,6 +540,7 @@ static int method_set_time(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bu
         Context *c = userdata;
         int64_t utc;
         struct timespec ts;
+        usec_t start;
         struct tm* tm;
         int r;
 
@@ -587,6 +588,13 @@ static int method_set_time(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bu
         if (r == 0)
                 return 1;
 
+        /* adjust ts for time spent in program */
+        r = sd_bus_message_get_monotonic_usec(m, &start);
+        if (r < 0 && r != -ENODATA)
+                return r;
+        if (r >= 0)
+                timespec_store(&ts, timespec_load(&ts) + (now(CLOCK_MONOTONIC) - start));
+
         /* Set system clock */
         if (clock_settime(CLOCK_REALTIME, &ts) < 0) {
                 log_error_errno(errno, "Failed to set local time: %m");
@@ -727,6 +735,8 @@ int main(int argc, char *argv[]) {
         if (r < 0)
                 goto finish;
 
+        (void)sd_bus_negotiate_timestamp(bus, true);
+
         r = context_read_data(&context);
         if (r < 0) {
                 log_error_errno(r, "Failed to read time zone data: %m");