diff options
Diffstat (limited to 'src/timedate/timedate-sntp.c')
| -rw-r--r-- | src/timedate/timedate-sntp.c | 178 |
1 files changed, 147 insertions, 31 deletions
diff --git a/src/timedate/timedate-sntp.c b/src/timedate/timedate-sntp.c index 861bcb151f..98a2172198 100644 --- a/src/timedate/timedate-sntp.c +++ b/src/timedate/timedate-sntp.c @@ -42,15 +42,19 @@ #include <arpa/inet.h> #include <netinet/in.h> #include <netinet/ip.h> +#include <sys/timerfd.h> #include <sys/timex.h> #include <sys/socket.h> +#include "missing.h" #include "util.h" #include "sparse-endian.h" #include "log.h" #include "sd-event.h" #include "timedate-sntp.h" +#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 @@ -114,29 +118,42 @@ struct ntp_msg { } _packed_; struct SNTPContext { + /* peer */ sd_event_source *event_receive; - sd_event_source *event_timer; - char *server; struct sockaddr_in server_addr; 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; + bool poll_resync; + /* statistics data */ struct { double offset; double delay; } samples[8]; unsigned int samples_idx; double samples_jitter; + + /* last change */ + bool jumped; + + /* watch for time changes */ + sd_event_source *event_clock_watch; + int clock_watch_fd; }; -static int sntp_arm_timer(SNTPContext *sntp); +static int sntp_arm_timer(SNTPContext *sntp, usec_t next); +static int sntp_clock_watch_setup(SNTPContext *sntp); static double ntp_ts_to_d(const struct ntp_ts *ts) { return be32toh(ts->sec) + ((double)be32toh(ts->frac) / UINT_MAX); @@ -197,19 +214,22 @@ static int sntp_send_request(SNTPContext *sntp) { addr.sin_port = htobe16(123); addr.sin_addr.s_addr = inet_addr(sntp->server); len = sendto(sntp->server_socket, &ntpmsg, sizeof(ntpmsg), MSG_DONTWAIT, &addr, sizeof(addr)); - if (len < 0) { - log_debug("Sending NTP request to %s failed: %m", sntp->server); - return -errno; - } - - sntp->pending = true; - - /* re-arm timer for next poll interval, in case the packet never arrives back */ - r = sntp_arm_timer(sntp); + if (len == sizeof(ntpmsg)) { + sntp->pending = true; + log_debug("Sent NTP request to: %s", sntp->server); + } else + log_info("Sending NTP request to %s failed: %m", sntp->server); + + /* re-arm timer with incresing timeout, in case the packets never arrive back */ + if (sntp->retry_interval > 0) { + if (sntp->retry_interval < NTP_POLL_INTERVAL_MAX_SEC * USEC_PER_SEC) + sntp->retry_interval *= 2; + } else + sntp->retry_interval = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC; + r = sntp_arm_timer(sntp, sntp->retry_interval); if (r < 0) return r; - log_debug("Sent NTP request to: %s", sntp->server); return 0; } @@ -222,20 +242,20 @@ static int sntp_timer(sd_event_source *source, usec_t usec, void *userdata) { return 0; } -static int sntp_arm_timer(SNTPContext *sntp) { +static int sntp_arm_timer(SNTPContext *sntp, usec_t next) { sd_event *e; int r; assert(sntp); assert(sntp->event_receive); - if (sntp->poll_interval <= 0) { + if (next == 0) { sntp->event_timer = sd_event_source_unref(sntp->event_timer); return 0; } if (sntp->event_timer) { - r = sd_event_source_set_time(sntp->event_timer, now(CLOCK_MONOTONIC) + sntp->poll_interval); + r = sd_event_source_set_time(sntp->event_timer, now(CLOCK_MONOTONIC) + next); if (r < 0) return r; @@ -243,13 +263,76 @@ static int sntp_arm_timer(SNTPContext *sntp) { } e = sd_event_source_get_event(sntp->event_receive); - r = sd_event_add_monotonic(e, &sntp->event_timer, now(CLOCK_MONOTONIC) + sntp->poll_interval, 0, sntp_timer, sntp); + r = sd_event_add_monotonic(e, &sntp->event_timer, now(CLOCK_MONOTONIC) + next, 0, sntp_timer, sntp); if (r < 0) return r; return 0; } +static int sntp_clock_watch(sd_event_source *source, int fd, uint32_t revents, void *userdata) { + SNTPContext *sntp = userdata; + + assert(sntp); + assert(sntp->event_receive); + + /* rearm timer */ + sntp_clock_watch_setup(sntp); + + /* skip our own jumps */ + if (sntp->jumped) { + sntp->jumped = false; + return 0; + } + + /* resync */ + log_info("System time changed, resyncing."); + sntp->poll_resync = true; + sntp_send_request(sntp); + + return 0; +} + +/* wake up when the system time changes underneath us */ +static int sntp_clock_watch_setup(SNTPContext *sntp) { + struct itimerspec its = { .it_value.tv_sec = TIME_T_MAX }; + _cleanup_close_ int fd = -1; + sd_event *e; + sd_event_source *source; + int r; + + assert(sntp); + assert(sntp->event_receive); + + fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC); + if (fd < 0) { + log_error("Failed to create timerfd: %m"); + return -errno; + } + + if (timerfd_settime(fd, TFD_TIMER_ABSTIME|TFD_TIMER_CANCEL_ON_SET, &its, NULL) < 0) { + log_error("Failed to set up timerfd: %m"); + return -errno; + } + + e = sd_event_source_get_event(sntp->event_receive); + r = sd_event_add_io(e, &source, fd, EPOLLIN, sntp_clock_watch, sntp); + if (r < 0) { + log_error("Failed to create clock watch event source: %s", strerror(-r)); + return r; + } + + sd_event_source_unref(sntp->event_clock_watch); + sntp->event_clock_watch = source; + + if (sntp->clock_watch_fd >= 0) + close(sntp->clock_watch_fd); + sntp->clock_watch_fd = fd; + fd = -1; + + return 0; +} + static int sntp_adjust_clock(SNTPContext *sntp, double offset, int leap_sec) { struct timex tmx = {}; int r; @@ -270,11 +353,12 @@ static int sntp_adjust_clock(SNTPContext *sntp, double offset, int leap_sec) { tmx.status = STA_PLL; tmx.offset = offset * 1000 * 1000; tmx.constant = constant; - log_debug(" adjust (slew): %+f sec\n", (double)tmx.offset / USEC_PER_SEC); } else { tmx.modes = ADJ_SETOFFSET; d_to_tv(offset, &tmx.time); + + sntp->jumped = true; log_debug(" adjust (jump): %+f sec\n", tv_to_d(&tmx.time)); } @@ -320,10 +404,12 @@ static bool sntp_sample_spike_detection(SNTPContext *sntp, double offset, double sntp->packet_count++; /* - * Spike detection; compare the difference between the - * current offset to the previous offset and jitter. + * Spike detection; compare the difference between the current offset to + * the previous offset and jitter. */ - spike = sntp->packet_count > 2 && fabs(offset - sntp->samples[idx_cur].offset) > sntp->samples_jitter * 3; + spike = !sntp->poll_resync && + sntp->packet_count > 2 && + fabs(offset - sntp->samples[idx_cur].offset) > sntp->samples_jitter * 3; /* calculate new jitter value from the RMS differences relative to the lowest delay sample */ for (idx_min = idx_cur, i = 0; i < ELEMENTSOF(sntp->samples); i++) @@ -340,6 +426,12 @@ static bool sntp_sample_spike_detection(SNTPContext *sntp, double offset, double static void sntp_adjust_poll(SNTPContext *sntp, double offset, bool spike) { double delta; + if (sntp->poll_resync) { + sntp->poll_interval = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC; + sntp->poll_resync = false; + return; + } + if (spike) { if (sntp->poll_interval > NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC) sntp->poll_interval /= 2; @@ -443,7 +535,6 @@ static int sntp_receive_response(sd_event_source *source, int fd, uint32_t reven log_debug("Unexpected reply, ignoring"); return 0; } - sntp->pending = false; /* check our "time cookie" (we just stored nanoseconds in the fraction field) */ if (be32toh(ntpmsg->origin_time.sec) != sntp->trans_time.tv_sec + OFFSET_1900_1970|| @@ -467,6 +558,10 @@ static int sntp_receive_response(sd_event_source *source, int fd, uint32_t reven return -EINVAL; } + /* valid packet */ + sntp->pending = false; + sntp->retry_interval = 0; + /* announce leap seconds */ if (NTP_FIELD_LEAP(ntpmsg->field) & NTP_LEAP_PLUSSEC) leap_sec = 1; @@ -539,7 +634,7 @@ static int sntp_receive_response(sd_event_source *source, int fd, uint32_t reven log_error("Failed to call clock_adjtime(): %m"); } - r = sntp_arm_timer(sntp); + r = sntp_arm_timer(sntp, sntp->poll_interval); if (r < 0) return r; @@ -575,27 +670,29 @@ void sntp_server_disconnect(SNTPContext *sntp) { return; sntp->event_timer = sd_event_source_unref(sntp->event_timer); + + sntp->event_clock_watch = sd_event_source_unref(sntp->event_clock_watch); + if (sntp->clock_watch_fd > 0) + close(sntp->clock_watch_fd); + sntp->clock_watch_fd = -1; + sntp->event_receive = sd_event_source_unref(sntp->event_receive); if (sntp->server_socket > 0) close(sntp->server_socket); sntp->server_socket = -1; + zero(sntp->server_addr); free(sntp->server); sntp->server = NULL; } -int sntp_new(SNTPContext **sntp, sd_event *e) { - _cleanup_free_ SNTPContext *c; +static int sntp_listen_setup(SNTPContext *sntp, sd_event *e) { _cleanup_close_ int fd = -1; struct sockaddr_in addr; const int on = 1; const int tos = IPTOS_LOWDELAY; int r; - c = new0(SNTPContext, 1); - if (!c) - return -ENOMEM; - fd = socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0); if (fd < 0) return -errno; @@ -614,13 +711,32 @@ int sntp_new(SNTPContext **sntp, sd_event *e) { if (r < 0) return -errno; - r = sd_event_add_io(e, &c->event_receive, fd, EPOLLIN, sntp_receive_response, c); + r = sd_event_add_io(e, &sntp->event_receive, fd, EPOLLIN, sntp_receive_response, sntp); if (r < 0) return r; - c->server_socket = fd; + sntp->server_socket = fd; fd = -1; + return 0; +} + +int sntp_new(SNTPContext **sntp, sd_event *e) { + _cleanup_free_ SNTPContext *c; + int r; + + c = new0(SNTPContext, 1); + if (!c) + return -ENOMEM; + + r = sntp_listen_setup(c, e); + if (r < 0) + return r; + + r = sntp_clock_watch_setup(c); + if (r < 0) + return r; + *sntp = c; c = NULL; |