-
-#define TIME_T_MAX (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
-
-#ifndef ADJ_SETOFFSET
-#define ADJ_SETOFFSET 0x0100 /* add 'time' to current time */
-#endif
-
-/* expected accuracy of time synchronization; used to adjust the poll interval */
-#define NTP_ACCURACY_SEC 0.2
-
-/*
- * "A client MUST NOT under any conditions use a poll interval less
- * than 15 seconds."
- */
-#define NTP_POLL_INTERVAL_MIN_SEC 32
-#define NTP_POLL_INTERVAL_MAX_SEC 2048
-
-/*
- * Maximum delta in seconds which the system clock is gradually adjusted
- * (slew) to approach the network time. Deltas larger that this are set by
- * letting the system time jump. The kernel's limit for adjtime is 0.5s.
- */
-#define NTP_MAX_ADJUST 0.4
-
-/* NTP protocol, packet header */
-#define NTP_LEAP_PLUSSEC 1
-#define NTP_LEAP_MINUSSEC 2
-#define NTP_LEAP_NOTINSYNC 3
-#define NTP_MODE_CLIENT 3
-#define NTP_MODE_SERVER 4
-#define NTP_FIELD_LEAP(f) (((f) >> 6) & 3)
-#define NTP_FIELD_VERSION(f) (((f) >> 3) & 7)
-#define NTP_FIELD_MODE(f) ((f) & 7)
-#define NTP_FIELD(l, v, m) (((l) << 6) | ((v) << 3) | (m))
-
-/*
- * "NTP timestamps are represented as a 64-bit unsigned fixed-point number,
- * in seconds relative to 0h on 1 January 1900."
- */
-#define OFFSET_1900_1970 2208988800UL
-
-#define RETRY_USEC (30*USEC_PER_SEC)
-#define RATELIMIT_INTERVAL_USEC (10*USEC_PER_SEC)
-#define RATELIMIT_BURST 10
-
-struct ntp_ts {
- be32_t sec;
- be32_t frac;
-} _packed_;
-
-struct ntp_ts_short {
- be16_t sec;
- be16_t frac;
-} _packed_;
-
-struct ntp_msg {
- uint8_t field;
- uint8_t stratum;
- int8_t poll;
- int8_t precision;
- struct ntp_ts_short root_delay;
- struct ntp_ts_short root_dispersion;
- char refid[4];
- struct ntp_ts reference_time;
- struct ntp_ts origin_time;
- struct ntp_ts recv_time;
- struct ntp_ts trans_time;
-} _packed_;
-
-typedef struct Manager Manager;
-typedef struct ServerAddress ServerAddress;
-typedef struct ServerName ServerName;
-
-struct ServerAddress {
- union sockaddr_union sockaddr;
- socklen_t socklen;
- LIST_FIELDS(ServerAddress, addresses);
-};
-
-struct ServerName {
- char *string;
- LIST_HEAD(ServerAddress, addresses);
- LIST_FIELDS(ServerName, names);
-};
-
-struct Manager {
- sd_event *event;
- sd_resolve *resolve;
-
- LIST_HEAD(ServerName, servers);
-
- RateLimit ratelimit;
-
- /* peer */
- sd_resolve_query *resolve_query;
- sd_event_source *event_receive;
- ServerName *current_server_name;
- ServerAddress *current_server_address;
- int server_socket;
- uint64_t packet_count;
-
- /* last sent packet */
- struct timespec trans_time_mon;
- struct timespec trans_time;
- usec_t retry_interval;
- bool pending;
-
- /* poll timer */
- sd_event_source *event_timer;
- usec_t poll_interval_usec;
- bool poll_resync;
-
- /* history data */
- struct {
- double offset;
- double delay;
- } samples[8];
- unsigned int samples_idx;
- double samples_jitter;
-
- /* last change */
- bool jumped;
- int drift_ppm;
-
- /* watch for time changes */
- sd_event_source *event_clock_watch;
- int clock_watch_fd;
-
- /* Retry connections */
- sd_event_source *event_retry;
-
- /* Handle SIGINT/SIGTERM */
- sd_event_source *sigterm, *sigint;
-};
-
-static void manager_free(Manager *m);
-DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free);
-#define _cleanup_manager_free_ _cleanup_(manager_freep)
-
-static int manager_arm_timer(Manager *m, usec_t next);
-static int manager_clock_watch_setup(Manager *m);
-static int manager_connect(Manager *m);
-static void manager_disconnect(Manager *m);
-
-static double ntp_ts_to_d(const struct ntp_ts *ts) {
- return be32toh(ts->sec) + ((double)be32toh(ts->frac) / UINT_MAX);
-}
-
-static double ts_to_d(const struct timespec *ts) {
- return ts->tv_sec + (1.0e-9 * ts->tv_nsec);
-}
-
-static double tv_to_d(const struct timeval *tv) {
- return tv->tv_sec + (1.0e-6 * tv->tv_usec);
-}
-
-static double square(double d) {
- return d * d;
-}
-
-static int manager_send_request(Manager *m) {
- _cleanup_free_ char *pretty = NULL;
- struct ntp_msg ntpmsg = {
- /*
- * "The client initializes the NTP message header, sends the request
- * to the server, and strips the time of day from the Transmit
- * Timestamp field of the reply. For this purpose, all the NTP
- * header fields are set to 0, except the Mode, VN, and optional
- * Transmit Timestamp fields."
- */
- .field = NTP_FIELD(0, 4, NTP_MODE_CLIENT),
- };
- ssize_t len;