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author | caoxia <caoxia2008cxx@126.com> | 2021-01-28 20:50:08 +0800 |
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committer | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2021-03-12 17:35:57 +0100 |
commit | 02e9679cceeaa8f2fd7a9f2370f222be969ea1da (patch) | |
tree | f4410e82057131aad732b0ed2b3f498b8042f8ed | |
parent | 4649b044d05f217bd756639161e6f7955a1c7f6b (diff) | |
download | systemd-02e9679cceeaa8f2fd7a9f2370f222be969ea1da.tar.gz |
trans_time sec is int32,it will overflow if local system time is later than 2038.
(cherry picked from commit 370d3c31b4637d1b2faeec555da3283e49a6744f)
-rw-r--r-- | src/timesync/timesyncd-manager.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/src/timesync/timesyncd-manager.c b/src/timesync/timesyncd-manager.c index 93ba4ef87d..e83ae5ec1e 100644 --- a/src/timesync/timesyncd-manager.c +++ b/src/timesync/timesyncd-manager.c @@ -73,6 +73,13 @@ static double ts_to_d(const struct timespec *ts) { return ts->tv_sec + (1.0e-9 * ts->tv_nsec); } +static uint32_t graceful_add_offset_1900_1970(time_t t) { + /* Adds OFFSET_1900_1970 to t and returns it as 32bit value. This is handles overflows + * gracefully in a deterministic and well-defined way by cutting off the top bits. */ + uint64_t a = (uint64_t) t + OFFSET_1900_1970; + return (uint32_t) (a & UINT64_C(0xFFFFFFFF)); +} + static int manager_timeout(sd_event_source *source, usec_t usec, void *userdata) { _cleanup_free_ char *pretty = NULL; Manager *m = userdata; @@ -122,7 +129,7 @@ static int manager_send_request(Manager *m) { */ assert_se(clock_gettime(clock_boottime_or_monotonic(), &m->trans_time_mon) >= 0); assert_se(clock_gettime(CLOCK_REALTIME, &m->trans_time) >= 0); - ntpmsg.trans_time.sec = htobe32(m->trans_time.tv_sec + OFFSET_1900_1970); + ntpmsg.trans_time.sec = htobe32(graceful_add_offset_1900_1970(m->trans_time.tv_sec)); ntpmsg.trans_time.frac = htobe32(m->trans_time.tv_nsec); server_address_pretty(m->current_server_address, &pretty); @@ -477,7 +484,7 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re m->missed_replies = 0; /* check our "time cookie" (we just stored nanoseconds in the fraction field) */ - if (be32toh(ntpmsg.origin_time.sec) != m->trans_time.tv_sec + OFFSET_1900_1970 || + if (be32toh(ntpmsg.origin_time.sec) != graceful_add_offset_1900_1970(m->trans_time.tv_sec) || be32toh(ntpmsg.origin_time.frac) != (unsigned long) m->trans_time.tv_nsec) { log_debug("Invalid reply; not our transmit time. Ignoring."); return 0; |