From c9c9f6f450f678a0d5e5b929ba238d4a5254bded Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 30 Apr 2020 13:24:31 +0200 Subject: calendarspec: be more graceful with two kinds of calendar expressions This changes the calendarspec parser to allow expressions such as "00:05..05", i.e. a range where start and end is the same. It also allows expressions such as "00:1-2/3", i.e. where the repetition value does not fit even once in the specified range. With this patch both cases will now be optimized away, i.e. the range is removed and a fixed value is used, which is functionally equivalent. See #15030 for an issue where the inability to parse such expressions caused confusion. I think it's probably better to accept these gracefully and optimizing them away instead of refusing them with a plain EINVAL. With a tool such as "systemd-analyze" calendar it should be easy to figure out the normalized form with the redundant bits optimized away. --- src/shared/calendarspec.c | 16 ++++++++++++++++ src/test/test-calendarspec.c | 4 ++-- 2 files changed, 18 insertions(+), 2 deletions(-) diff --git a/src/shared/calendarspec.c b/src/shared/calendarspec.c index 084965e64e..b162224d9d 100644 --- a/src/shared/calendarspec.c +++ b/src/shared/calendarspec.c @@ -91,6 +91,16 @@ static void normalize_chain(CalendarComponent **c) { if (i->stop > i->start && i->repeat > 0) i->stop -= (i->stop - i->start) % i->repeat; + /* If a repeat value is specified, but it cannot even be triggered once, let's suppress + * it. + * + * Similar, if the stop value is the same as the start value, then let's just make this a + * non-repeating chain element */ + if ((i->stop > i->start && i->repeat > 0 && i->start + i->repeat > i->stop) || + i->start == i->stop) { + i->repeat = 0; + i->stop = -1; + } } if (n <= 1) @@ -645,6 +655,12 @@ static int prepend_component(const char **p, bool usec, unsigned nesting, Calend if (repeat == 0) return -ERANGE; + } else { + /* If no repeat value is specified for the µs component, then let's explicitly refuse ranges + * below 1s because our default repeat granularity is beyond that. */ + + if (usec && stop >= 0 && start + repeat > stop) + return -EINVAL; } if (!IN_SET(*e, 0, ' ', ',', '-', '~', ':')) diff --git a/src/test/test-calendarspec.c b/src/test/test-calendarspec.c index 9c2be7f445..9e2ae55ab6 100644 --- a/src/test/test-calendarspec.c +++ b/src/test/test-calendarspec.c @@ -185,6 +185,8 @@ int main(int argc, char* argv[]) { test_one("@1493187147 UTC", "2017-04-26 06:12:27 UTC"); test_one("@0", "1970-01-01 00:00:00 UTC"); test_one("@0 UTC", "1970-01-01 00:00:00 UTC"); + test_one("*:05..05", "*-*-* *:05:00"); + test_one("*:05..10/6", "*-*-* *:05:00"); test_next("2016-03-27 03:17:00", "", 12345, 1459048620000000); test_next("2016-03-27 03:17:00", "CET", 12345, 1459041420000000); @@ -237,8 +239,6 @@ int main(int argc, char* argv[]) { assert_se(calendar_spec_from_string("*~29", &c) < 0); assert_se(calendar_spec_from_string("*~16..31", &c) < 0); assert_se(calendar_spec_from_string("12..1/2-*", &c) < 0); - assert_se(calendar_spec_from_string("*:05..05", &c) < 0); - assert_se(calendar_spec_from_string("*:05..10/6", &c) < 0); assert_se(calendar_spec_from_string("20/4:00", &c) < 0); assert_se(calendar_spec_from_string("00:00/60", &c) < 0); assert_se(calendar_spec_from_string("00:00:2300", &c) < 0); -- cgit v1.2.1