X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Ftimesync%2Ftimesyncd.c;h=19e6d67c63d6203c9221455420852b3eb5ce97cc;hp=7b7ec7ae9f5b15e11eb1afae5c7483beef354f78;hb=f864fd1b4b4546244dfb59bb59196598742fa29c;hpb=81c36b3f28103c72e1b1c80a2af0dcc308a07bcf diff --git a/src/timesync/timesyncd.c b/src/timesync/timesyncd.c index 7b7ec7ae9..19e6d67c6 100644 --- a/src/timesync/timesyncd.c +++ b/src/timesync/timesyncd.c @@ -3,7 +3,7 @@ /*** This file is part of systemd. - Copyright 2014 Kay Sievers + Copyright 2014 Kay Sievers, Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by @@ -32,13 +32,28 @@ #include #include #include +#include +#include +#include +#include #include "missing.h" #include "util.h" #include "sparse-endian.h" #include "log.h" +#include "socket-util.h" +#include "list.h" +#include "ratelimit.h" +#include "strv.h" +#include "conf-parser.h" #include "sd-event.h" +#include "sd-resolve.h" #include "sd-daemon.h" +#include "sd-network.h" +#include "event-util.h" +#include "network-util.h" +#include "capability.h" +#include "timesyncd.h" #define TIME_T_MAX (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1) @@ -80,6 +95,12 @@ */ #define OFFSET_1900_1970 2208988800UL +#define RETRY_USEC (30*USEC_PER_SEC) +#define RATELIMIT_INTERVAL_USEC (10*USEC_PER_SEC) +#define RATELIMIT_BURST 10 + +#define TIMEOUT_USEC (10*USEC_PER_SEC) + struct ntp_ts { be32_t sec; be32_t frac; @@ -104,93 +125,65 @@ struct ntp_msg { struct ntp_ts trans_time; } _packed_; -typedef struct Manager Manager; -struct Manager { - sd_event *event; - - /* peer */ - sd_event_source *event_receive; - 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_usec; - bool poll_resync; - - /* history 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 void manager_free(Manager *m); DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free); #define _cleanup_manager_free_ _cleanup_(manager_freep) -static int sntp_arm_timer(Manager *m, usec_t next); -static int sntp_clock_watch_setup(Manager *m); -static void sntp_server_disconnect(Manager *m); +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 tv_to_d(const struct timeval *tv) { - return tv->tv_sec + (1.0e-6 * tv->tv_usec); -} - static double ts_to_d(const struct timespec *ts) { return ts->tv_sec + (1.0e-9 * ts->tv_nsec); } -static void d_to_tv(double d, struct timeval *tv) { - tv->tv_sec = (long)d; - tv->tv_usec = (d - tv->tv_sec) * 1000 * 1000; - - /* the kernel expects -0.3s as {-1, 7000.000} */ - if (tv->tv_usec < 0) { - tv->tv_sec -= 1; - tv->tv_usec += 1000 * 1000; - } +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 sntp_send_request(Manager *m) { - struct ntp_msg ntpmsg = {}; - struct sockaddr_in addr = {}; +static int manager_timeout(sd_event_source *source, usec_t usec, void *userdata) { + _cleanup_free_ char *pretty = NULL; + Manager *m = userdata; + + assert(m); + assert(m->current_server_name); + assert(m->current_server_address); + + sockaddr_pretty(&m->current_server_address->sockaddr.sa, m->current_server_address->socklen, true, &pretty); + log_info("Timed out waiting for reply from %s (%s).", strna(pretty), m->current_server_name->string); + + return manager_connect(m); +} + +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; int r; - /* - * "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." - */ - ntpmsg.field = NTP_FIELD(0, 4, NTP_MODE_CLIENT); + assert(m); + assert(m->current_server_name); + assert(m->current_server_address); + + m->event_timeout = sd_event_source_unref(m->event_timeout); /* * Set transmit timestamp, remember it; the server will send that back @@ -200,44 +193,58 @@ static int sntp_send_request(Manager *m) { * The actual value does not matter, We do not care about the correct * NTP UINT_MAX fraction; we just pass the plain nanosecond value. */ - clock_gettime(CLOCK_MONOTONIC, &m->trans_time_mon); - clock_gettime(CLOCK_REALTIME, &m->trans_time); + assert_se(clock_gettime(CLOCK_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.frac = htobe32(m->trans_time.tv_nsec); - addr.sin_family = AF_INET; - addr.sin_port = htobe16(123); - addr.sin_addr.s_addr = inet_addr(m->server); - len = sendto(m->server_socket, &ntpmsg, sizeof(ntpmsg), MSG_DONTWAIT, &addr, sizeof(addr)); + sockaddr_pretty(&m->current_server_address->sockaddr.sa, m->current_server_address->socklen, true, &pretty); + + len = sendto(m->server_socket, &ntpmsg, sizeof(ntpmsg), MSG_DONTWAIT, &m->current_server_address->sockaddr.sa, m->current_server_address->socklen); if (len == sizeof(ntpmsg)) { m->pending = true; - log_debug("Sent NTP request to: %s", m->server); - } else - log_debug("Sending NTP request to %s failed: %m", m->server); + log_debug("Sent NTP request to %s (%s).", strna(pretty), m->current_server_name->string); + } else { + log_debug("Sending NTP request to %s (%s) failed: %m", strna(pretty), m->current_server_name->string); + return manager_connect(m); + } - /* re-arm timer with incresing timeout, in case the packets never arrive back */ + /* re-arm timer with increasing timeout, in case the packets never arrive back */ if (m->retry_interval > 0) { if (m->retry_interval < NTP_POLL_INTERVAL_MAX_SEC * USEC_PER_SEC) m->retry_interval *= 2; } else m->retry_interval = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC; - r = sntp_arm_timer(m, m->retry_interval); - if (r < 0) + + r = manager_arm_timer(m, m->retry_interval); + if (r < 0) { + log_error("Failed to rearm timer: %s", strerror(-r)); return r; + } + + r = sd_event_add_time( + m->event, + &m->event_timeout, + CLOCK_MONOTONIC, + now(CLOCK_MONOTONIC) + TIMEOUT_USEC, 0, + manager_timeout, m); + if (r < 0) { + log_error("Failed to arm timeout timer: %s", strerror(-r)); + return r; + } return 0; } -static int sntp_timer(sd_event_source *source, usec_t usec, void *userdata) { +static int manager_timer(sd_event_source *source, usec_t usec, void *userdata) { Manager *m = userdata; assert(m); - sntp_send_request(m); - return 0; + return manager_send_request(m); } -static int sntp_arm_timer(Manager *m, usec_t next) { +static int manager_arm_timer(Manager *m, usec_t next) { int r; assert(m); @@ -256,26 +263,21 @@ static int sntp_arm_timer(Manager *m, usec_t next) { return sd_event_source_set_enabled(m->event_timer, SD_EVENT_ONESHOT); } - r = sd_event_add_time( + return sd_event_add_time( m->event, &m->event_timer, CLOCK_MONOTONIC, now(CLOCK_MONOTONIC) + next, 0, - sntp_timer, m); - if (r < 0) - return r; - - return 0; + manager_timer, m); } -static int sntp_clock_watch(sd_event_source *source, int fd, uint32_t revents, void *userdata) { +static int manager_clock_watch(sd_event_source *source, int fd, uint32_t revents, void *userdata) { Manager *m = userdata; assert(m); - assert(m->event_receive); /* rearm timer */ - sntp_clock_watch_setup(m); + manager_clock_watch_setup(m); /* skip our own jumps */ if (m->jumped) { @@ -286,55 +288,49 @@ static int sntp_clock_watch(sd_event_source *source, int fd, uint32_t revents, v /* resync */ log_info("System time changed. Resyncing."); m->poll_resync = true; - sntp_send_request(m); - - return 0; + return manager_send_request(m); } /* wake up when the system time changes underneath us */ -static int sntp_clock_watch_setup(Manager *m) { - struct itimerspec its = { .it_value.tv_sec = TIME_T_MAX }; - _cleanup_close_ int fd = -1; - sd_event *e; - sd_event_source *source; +static int manager_clock_watch_setup(Manager *m) { + + struct itimerspec its = { + .it_value.tv_sec = TIME_T_MAX + }; + int r; assert(m); - assert(m->event_receive); - fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC); - if (fd < 0) { + m->event_clock_watch = sd_event_source_unref(m->event_clock_watch); + safe_close(m->clock_watch_fd); + + m->clock_watch_fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC); + if (m->clock_watch_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) { + if (timerfd_settime(m->clock_watch_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(m->event_receive); - r = sd_event_add_io(e, &source, fd, EPOLLIN, sntp_clock_watch, m); + r = sd_event_add_io(m->event, &m->event_clock_watch, m->clock_watch_fd, EPOLLIN, manager_clock_watch, m); if (r < 0) { log_error("Failed to create clock watch event source: %s", strerror(-r)); return r; } - sd_event_source_unref(m->event_clock_watch); - m->event_clock_watch = source; - - if (m->clock_watch_fd >= 0) - close(m->clock_watch_fd); - m->clock_watch_fd = fd; - fd = -1; - return 0; } -static int sntp_adjust_clock(Manager *m, double offset, int leap_sec) { +static int manager_adjust_clock(Manager *m, double offset, int leap_sec) { struct timex tmx = {}; int r; + assert(m); + /* * For small deltas, tell the kernel to gradually adjust the system * clock to the NTP time, larger deltas are just directly set. @@ -343,19 +339,28 @@ static int sntp_adjust_clock(Manager *m, double offset, int leap_sec) { * syncs the system time periodically to the hardware clock. */ if (fabs(offset) < NTP_MAX_ADJUST) { - tmx.modes = ADJ_STATUS | ADJ_OFFSET | ADJ_TIMECONST | ADJ_MAXERROR | ADJ_ESTERROR; + tmx.modes = ADJ_STATUS | ADJ_NANO | ADJ_OFFSET | ADJ_TIMECONST | ADJ_MAXERROR | ADJ_ESTERROR; tmx.status = STA_PLL; - tmx.offset = offset * USEC_PER_SEC; - tmx.constant = log2i(m->poll_interval_usec / USEC_PER_SEC) - 6; + tmx.offset = offset * NSEC_PER_SEC; + tmx.constant = log2i(m->poll_interval_usec / USEC_PER_SEC) - 4; tmx.maxerror = 0; tmx.esterror = 0; - log_debug(" adjust (slew): %+.3f sec\n", (double)tmx.offset / USEC_PER_SEC); + log_debug(" adjust (slew): %+.3f sec\n", offset); } else { - tmx.modes = ADJ_SETOFFSET; - d_to_tv(offset, &tmx.time); + tmx.modes = ADJ_SETOFFSET | ADJ_NANO; + + /* ADJ_NANO uses nanoseconds in the microseconds field */ + tmx.time.tv_sec = (long)offset; + tmx.time.tv_usec = (offset - tmx.time.tv_sec) * NSEC_PER_SEC; + + /* the kernel expects -0.3s as {-1, 7000.000.000} */ + if (tmx.time.tv_usec < 0) { + tmx.time.tv_sec -= 1; + tmx.time.tv_usec += NSEC_PER_SEC; + } m->jumped = true; - log_debug(" adjust (jump): %+.3f sec\n", tv_to_d(&tmx.time)); + log_debug(" adjust (jump): %+.3f sec\n", offset); } switch (leap_sec) { @@ -371,25 +376,29 @@ static int sntp_adjust_clock(Manager *m, double offset, int leap_sec) { if (r < 0) return r; + m->drift_ppm = tmx.freq / 65536; + log_debug(" status : %04i %s\n" " time now : %li.%03lli\n" " constant : %li\n" " offset : %+.3f sec\n" - " freq offset : %+li (%+.3f ppm)\n", + " freq offset : %+li (%i ppm)\n", tmx.status, tmx.status & STA_UNSYNC ? "" : "sync", - tmx.time.tv_sec, tmx.time.tv_usec / USEC_PER_MSEC, + tmx.time.tv_sec, tmx.time.tv_usec / NSEC_PER_MSEC, tmx.constant, - (double)tmx.offset / USEC_PER_SEC, - tmx.freq, (double)tmx.freq / 65536); + (double)tmx.offset / NSEC_PER_SEC, + tmx.freq, m->drift_ppm); return 0; } -static bool sntp_sample_spike_detection(Manager *m, double offset, double delay) { +static bool manager_sample_spike_detection(Manager *m, double offset, double delay) { unsigned int i, idx_cur, idx_new, idx_min; double jitter; double j; + assert(m); + m->packet_count++; /* ignore initial sample */ @@ -434,7 +443,9 @@ static bool sntp_sample_spike_detection(Manager *m, double offset, double delay) return fabs(offset - m->samples[idx_cur].offset) > 3 * jitter; } -static void sntp_adjust_poll(Manager *m, double offset, bool spike) { +static void manager_adjust_poll(Manager *m, double offset, bool spike) { + assert(m); + if (m->poll_resync) { m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC; m->poll_resync = false; @@ -462,18 +473,35 @@ static void sntp_adjust_poll(Manager *m, double offset, bool spike) { } } -static int sntp_receive_response(sd_event_source *source, int fd, uint32_t revents, void *userdata) { +static bool sockaddr_equal(union sockaddr_union *a, union sockaddr_union *b) { + assert(a); + assert(b); + + if (a->sa.sa_family != b->sa.sa_family) + return false; + + if (a->sa.sa_family == AF_INET) + return a->in.sin_addr.s_addr == b->in.sin_addr.s_addr; + + if (a->sa.sa_family == AF_INET6) + return memcmp(&a->in6.sin6_addr, &b->in6.sin6_addr, sizeof(a->in6.sin6_addr)) == 0; + + return false; +} + +static int manager_receive_response(sd_event_source *source, int fd, uint32_t revents, void *userdata) { Manager *m = userdata; - unsigned char buf[sizeof(struct ntp_msg)]; + struct ntp_msg ntpmsg; + struct iovec iov = { - .iov_base = buf, - .iov_len = sizeof(buf), + .iov_base = &ntpmsg, + .iov_len = sizeof(ntpmsg), }; union { struct cmsghdr cmsghdr; uint8_t buf[CMSG_SPACE(sizeof(struct timeval))]; } control; - struct sockaddr_in server_addr; + union sockaddr_union server_addr; struct msghdr msghdr = { .msg_iov = &iov, .msg_iovlen = 1, @@ -486,33 +514,39 @@ static int sntp_receive_response(sd_event_source *source, int fd, uint32_t reven struct timespec now_ts; struct timeval *recv_time; ssize_t len; - struct ntp_msg *ntpmsg; double origin, receive, trans, dest; double delay, offset; bool spike; int leap_sec; int r; + assert(source); + assert(m); + if (revents & (EPOLLHUP|EPOLLERR)) { - log_debug("Server connection returned error. Closing."); - sntp_server_disconnect(m); - return -ENOTCONN; + log_warning("Server connection returned error."); + return manager_connect(m); } len = recvmsg(fd, &msghdr, MSG_DONTWAIT); if (len < 0) { - log_debug("Error receiving message. Disconnecting."); - return -EINVAL; + if (errno == EAGAIN) + return 0; + + log_warning("Error receiving message. Disconnecting."); + return manager_connect(m); } if (iov.iov_len < sizeof(struct ntp_msg)) { - log_debug("Invalid response from server. Disconnecting."); - return -EINVAL; + log_warning("Invalid response from server. Disconnecting."); + return manager_connect(m); } - if (m->server_addr.sin_addr.s_addr != server_addr.sin_addr.s_addr) { - log_debug("Response from unknown server. Disconnecting."); - return -EINVAL; + if (!m->current_server_name || + !m->current_server_address || + !sockaddr_equal(&server_addr, &m->current_server_address->sockaddr)) { + log_debug("Response from unknown server."); + return 0; } recv_time = NULL; @@ -527,36 +561,43 @@ static int sntp_receive_response(sd_event_source *source, int fd, uint32_t reven } } if (!recv_time) { - log_debug("Invalid packet timestamp. Disconnecting."); + log_error("Invalid packet timestamp."); return -EINVAL; } - ntpmsg = iov.iov_base; if (!m->pending) { log_debug("Unexpected reply. Ignoring."); return 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 || - be32toh(ntpmsg->origin_time.frac) != m->trans_time.tv_nsec) { + if (be32toh(ntpmsg.origin_time.sec) != m->trans_time.tv_sec + OFFSET_1900_1970 || + be32toh(ntpmsg.origin_time.frac) != m->trans_time.tv_nsec) { log_debug("Invalid reply; not our transmit time. Ignoring."); return 0; } - if (NTP_FIELD_LEAP(ntpmsg->field) == NTP_LEAP_NOTINSYNC) { + m->event_timeout = sd_event_source_unref(m->event_timeout); + + if (be32toh(ntpmsg.recv_time.sec) < TIME_EPOCH + OFFSET_1900_1970 || + be32toh(ntpmsg.trans_time.sec) < TIME_EPOCH + OFFSET_1900_1970) { + log_debug("Invalid reply, returned times before epoch. Ignoring."); + return manager_connect(m); + } + + if (NTP_FIELD_LEAP(ntpmsg.field) == NTP_LEAP_NOTINSYNC) { log_debug("Server is not synchronized. Disconnecting."); - return -EINVAL; + return manager_connect(m); } - if (NTP_FIELD_VERSION(ntpmsg->field) != 4) { - log_debug("Response NTPv%d. Disconnecting.", NTP_FIELD_VERSION(ntpmsg->field)); - return -EINVAL; + if (!IN_SET(NTP_FIELD_VERSION(ntpmsg.field), 3, 4)) { + log_debug("Response NTPv%d. Disconnecting.", NTP_FIELD_VERSION(ntpmsg.field)); + return manager_connect(m); } - if (NTP_FIELD_MODE(ntpmsg->field) != NTP_MODE_SERVER) { - log_debug("Unsupported mode %d. Disconnecting.", NTP_FIELD_MODE(ntpmsg->field)); - return -EINVAL; + if (NTP_FIELD_MODE(ntpmsg.field) != NTP_MODE_SERVER) { + log_debug("Unsupported mode %d. Disconnecting.", NTP_FIELD_MODE(ntpmsg.field)); + return manager_connect(m); } /* valid packet */ @@ -564,9 +605,9 @@ static int sntp_receive_response(sd_event_source *source, int fd, uint32_t reven m->retry_interval = 0; /* announce leap seconds */ - if (NTP_FIELD_LEAP(ntpmsg->field) & NTP_LEAP_PLUSSEC) + if (NTP_FIELD_LEAP(ntpmsg.field) & NTP_LEAP_PLUSSEC) leap_sec = 1; - else if (NTP_FIELD_LEAP(ntpmsg->field) & NTP_LEAP_MINUSSEC) + else if (NTP_FIELD_LEAP(ntpmsg.field) & NTP_LEAP_MINUSSEC) leap_sec = -1; else leap_sec = 0; @@ -582,25 +623,25 @@ static int sntp_receive_response(sd_event_source *source, int fd, uint32_t reven * The round-trip delay, d, and system clock offset, t, are defined as: * d = (T4 - T1) - (T3 - T2) t = ((T2 - T1) + (T3 - T4)) / 2" */ - clock_gettime(CLOCK_MONOTONIC, &now_ts); + assert_se(clock_gettime(CLOCK_MONOTONIC, &now_ts) >= 0); origin = tv_to_d(recv_time) - (ts_to_d(&now_ts) - ts_to_d(&m->trans_time_mon)) + OFFSET_1900_1970; - receive = ntp_ts_to_d(&ntpmsg->recv_time); - trans = ntp_ts_to_d(&ntpmsg->trans_time); + receive = ntp_ts_to_d(&ntpmsg.recv_time); + trans = ntp_ts_to_d(&ntpmsg.trans_time); dest = tv_to_d(recv_time) + OFFSET_1900_1970; offset = ((receive - origin) + (trans - dest)) / 2; delay = (dest - origin) - (trans - receive); - spike = sntp_sample_spike_detection(m, offset, delay); + spike = manager_sample_spike_detection(m, offset, delay); - sntp_adjust_poll(m, offset, spike); + manager_adjust_poll(m, offset, spike); log_debug("NTP response:\n" " leap : %u\n" " version : %u\n" " mode : %u\n" " stratum : %u\n" - " precision : %.3f sec (%d)\n" + " precision : %.6f sec (%d)\n" " reference : %.4s\n" " origin : %.3f\n" " receive : %.3f\n" @@ -611,12 +652,12 @@ static int sntp_receive_response(sd_event_source *source, int fd, uint32_t reven " packet count : %"PRIu64"\n" " jitter : %.3f%s\n" " poll interval: %llu\n", - NTP_FIELD_LEAP(ntpmsg->field), - NTP_FIELD_VERSION(ntpmsg->field), - NTP_FIELD_MODE(ntpmsg->field), - ntpmsg->stratum, - exp2(ntpmsg->precision), ntpmsg->precision, - ntpmsg->stratum == 1 ? ntpmsg->refid : "n/a", + NTP_FIELD_LEAP(ntpmsg.field), + NTP_FIELD_VERSION(ntpmsg.field), + NTP_FIELD_MODE(ntpmsg.field), + ntpmsg.stratum, + exp2(ntpmsg.precision), ntpmsg.precision, + ntpmsg.stratum == 1 ? ntpmsg.refid : "n/a", origin - OFFSET_1900_1970, receive - OFFSET_1900_1970, trans - OFFSET_1900_1970, @@ -626,102 +667,299 @@ static int sntp_receive_response(sd_event_source *source, int fd, uint32_t reven m->samples_jitter, spike ? " spike" : "", m->poll_interval_usec / USEC_PER_SEC); - log_info("%s: interval/delta/delay/jitter %llu/%+.3f/%.3f/%.3f%s", - m->server, m->poll_interval_usec / USEC_PER_SEC, offset, delay, m->samples_jitter, spike ? " (ignored)" : ""); - if (!spike) { - r = sntp_adjust_clock(m, offset, leap_sec); + r = manager_adjust_clock(m, offset, leap_sec); if (r < 0) log_error("Failed to call clock_adjtime(): %m"); } - r = sntp_arm_timer(m, m->poll_interval_usec); - if (r < 0) + log_info("interval/delta/delay/jitter/drift %llus/%+.3fs/%.3fs/%.3fs/%+ippm%s", + m->poll_interval_usec / USEC_PER_SEC, offset, delay, m->samples_jitter, m->drift_ppm, + spike ? " (ignored)" : ""); + + r = manager_arm_timer(m, m->poll_interval_usec); + if (r < 0) { + log_error("Failed to rearm timer: %s", strerror(-r)); return r; + } return 0; } -static int sntp_server_connect(Manager *m, const char *server) { - _cleanup_free_ char *s = NULL; +static int manager_listen_setup(Manager *m) { + union sockaddr_union addr = {}; + static const int tos = IPTOS_LOWDELAY; + static const int on = 1; + int r; assert(m); - assert(server); - assert(m->server_socket >= 0); - s = strdup(server); - if (!s) - return -ENOMEM; + assert(m->server_socket < 0); + assert(!m->event_receive); + assert(m->current_server_address); + + addr.sa.sa_family = m->current_server_address->sockaddr.sa.sa_family; + + m->server_socket = socket(addr.sa.sa_family, SOCK_DGRAM | SOCK_CLOEXEC, 0); + if (m->server_socket < 0) + return -errno; + + r = bind(m->server_socket, &addr.sa, m->current_server_address->socklen); + if (r < 0) + return -errno; - free(m->server); - m->server = s; - s = NULL; + r = setsockopt(m->server_socket, SOL_SOCKET, SO_TIMESTAMP, &on, sizeof(on)); + if (r < 0) + return -errno; - zero(m->server_addr); - m->server_addr.sin_family = AF_INET; - m->server_addr.sin_addr.s_addr = inet_addr(server); + setsockopt(m->server_socket, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)); + + return sd_event_add_io(m->event, &m->event_receive, m->server_socket, EPOLLIN, manager_receive_response, m); +} + +static int manager_begin(Manager *m) { + _cleanup_free_ char *pretty = NULL; + int r; + + assert(m); + assert_return(m->current_server_name, -EHOSTUNREACH); + assert_return(m->current_server_address, -EHOSTUNREACH); m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC; - return sntp_send_request(m); + sockaddr_pretty(&m->current_server_address->sockaddr.sa, m->current_server_address->socklen, true, &pretty); + log_info("Using NTP server %s (%s).", strna(pretty), m->current_server_name->string); + sd_notifyf(false, "STATUS=Using Time Server %s (%s).", strna(pretty), m->current_server_name->string); + + r = manager_listen_setup(m); + if (r < 0) { + log_warning("Failed to setup connection socket: %s", strerror(-r)); + return r; + } + + r = manager_clock_watch_setup(m); + if (r < 0) + return r; + + return manager_send_request(m); } -static void sntp_server_disconnect(Manager *m) { - if (!m->server) - return; +static void server_name_flush_addresses(ServerName *n) { + ServerAddress *a; - m->event_timer = sd_event_source_unref(m->event_timer); + assert(n); - m->event_clock_watch = sd_event_source_unref(m->event_clock_watch); - if (m->clock_watch_fd > 0) - close(m->clock_watch_fd); - m->clock_watch_fd = -1; + while ((a = n->addresses)) { + LIST_REMOVE(addresses, n->addresses, a); + free(a); + } +} - m->event_receive = sd_event_source_unref(m->event_receive); - if (m->server_socket > 0) - close(m->server_socket); - m->server_socket = -1; +static void manager_flush_names(Manager *m) { + ServerName *n; + + assert(m); - zero(m->server_addr); - free(m->server); - m->server = NULL; + while ((n = m->servers)) { + LIST_REMOVE(names, m->servers, n); + free(n->string); + server_name_flush_addresses(n); + free(n); + } } -static int sntp_listen_setup(Manager *m) { - _cleanup_close_ int fd = -1; - struct sockaddr_in addr; - const int on = 1; - const int tos = IPTOS_LOWDELAY; +static int manager_resolve_handler(sd_resolve_query *q, int ret, const struct addrinfo *ai, void *userdata) { + Manager *m = userdata; + ServerAddress *a, *last = NULL; + + assert(q); + assert(m); + assert(m->current_server_name); + + m->resolve_query = sd_resolve_query_unref(m->resolve_query); + + if (ret != 0) { + log_info("Failed to resolve %s: %s", m->current_server_name->string, gai_strerror(ret)); + + /* Try next host */ + return manager_connect(m); + } + + server_name_flush_addresses(m->current_server_name); + + for (; ai; ai = ai->ai_next) { + _cleanup_free_ char *pretty = NULL; + + assert(ai->ai_addr); + assert(ai->ai_addrlen >= offsetof(struct sockaddr, sa_data)); + assert(ai->ai_addrlen <= sizeof(union sockaddr_union)); + + if (!IN_SET(ai->ai_addr->sa_family, AF_INET, AF_INET6)) { + log_warning("Unsuitable address protocol for %s", m->current_server_name->string); + continue; + } + + a = new0(ServerAddress, 1); + if (!a) + return log_oom(); + + memcpy(&a->sockaddr, ai->ai_addr, ai->ai_addrlen); + a->socklen = ai->ai_addrlen; + + LIST_INSERT_AFTER(addresses, m->current_server_name->addresses, last, a); + last = a; + + sockaddr_pretty(&a->sockaddr.sa, a->socklen, true, &pretty); + log_debug("Resolved address %s for %s.", pretty, m->current_server_name->string); + } + + if (!m->current_server_name->addresses) { + log_error("Failed to find suitable address for host %s.", m->current_server_name->string); + + /* Try next host */ + return manager_connect(m); + } + + m->current_server_address = m->current_server_name->addresses; + + return manager_begin(m); +} + +static int manager_retry(sd_event_source *source, usec_t usec, void *userdata) { + Manager *m = userdata; + + assert(m); + + return manager_connect(m); +} + +static int manager_connect(Manager *m) { + + struct addrinfo hints = { + .ai_flags = AI_NUMERICSERV|AI_ADDRCONFIG, + .ai_socktype = SOCK_DGRAM, + }; int r; - fd = socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0); - if (fd < 0) - return -errno; + assert(m); - zero(addr); - addr.sin_family = AF_INET; - r = bind(fd, (struct sockaddr *)&addr, sizeof(addr)); - if (r < 0) - return -errno; + manager_disconnect(m); - r = setsockopt(fd, SOL_SOCKET, SO_TIMESTAMP, &on, sizeof(on)); - if (r < 0) - return -errno; + m->event_retry = sd_event_source_unref(m->event_retry); + if (!ratelimit_test(&m->ratelimit)) { + log_debug("Slowing down attempts to contact servers."); - r = setsockopt(fd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)); - if (r < 0) - return -errno; + r = sd_event_add_time(m->event, &m->event_retry, CLOCK_MONOTONIC, now(CLOCK_MONOTONIC) + RETRY_USEC, 0, manager_retry, m); + if (r < 0) { + log_error("Failed to create retry timer: %s", strerror(-r)); + return r; + } - r = sd_event_add_io(m->event, &m->event_receive, fd, EPOLLIN, sntp_receive_response, m); + return 0; + } + + /* If we already are operating on some address, switch to the + * next one. */ + if (m->current_server_address && m->current_server_address->addresses_next) + m->current_server_address = m->current_server_address->addresses_next; + else { + /* Hmm, we are through all addresses, let's look for the next host instead */ + m->current_server_address = NULL; + + if (m->current_server_name && m->current_server_name->names_next) + m->current_server_name = m->current_server_name->names_next; + else { + if (!m->servers) { + m->current_server_name = NULL; + log_debug("No server found."); + return 0; + } + + m->current_server_name = m->servers; + } + + /* Tell the resolver to reread /etc/resolv.conf, in + * case it changed. */ + res_init(); + + r = sd_resolve_getaddrinfo(m->resolve, &m->resolve_query, m->current_server_name->string, "123", &hints, manager_resolve_handler, m); + if (r < 0) { + log_error("Failed to create resolver: %s", strerror(-r)); + return r; + } + + return 1; + } + + r = manager_begin(m); if (r < 0) return r; - m->server_socket = fd; - fd = -1; + return 1; +} + +static int manager_add_server(Manager *m, const char *server) { + ServerName *n, *tail; + + assert(m); + assert(server); + + n = new0(ServerName, 1); + if (!n) + return -ENOMEM; + + n->string = strdup(server); + if (!n->string) { + free(n); + return -ENOMEM; + } + + LIST_FIND_TAIL(names, m->servers, tail); + LIST_INSERT_AFTER(names, m->servers, tail, n); return 0; } +static int manager_add_server_string(Manager *m, const char *string) { + char *w, *state; + size_t l; + int r; + + assert(m); + assert(string); + + FOREACH_WORD_QUOTED(w, l, string, state) { + char t[l+1]; + + memcpy(t, w, l); + t[l] = 0; + + r = manager_add_server(m, t); + if (r < 0) + log_error("Failed to add server %s to configuration, ignoring: %s", t, strerror(-r)); + } + + return 0; +} + +static void manager_disconnect(Manager *m) { + assert(m); + + m->resolve_query = sd_resolve_query_unref(m->resolve_query); + + m->event_timer = sd_event_source_unref(m->event_timer); + + m->event_receive = sd_event_source_unref(m->event_receive); + m->server_socket = safe_close(m->server_socket); + + m->event_clock_watch = sd_event_source_unref(m->event_clock_watch); + m->clock_watch_fd = safe_close(m->clock_watch_fd); + + m->event_timeout = sd_event_source_unref(m->event_timeout); + + sd_notifyf(false, "STATUS=Idle."); +} + static int manager_new(Manager **ret) { _cleanup_manager_free_ Manager *m = NULL; int r; @@ -730,15 +968,28 @@ static int manager_new(Manager **ret) { if (!m) return -ENOMEM; + m->server_socket = m->clock_watch_fd = -1; + + RATELIMIT_INIT(m->ratelimit, RATELIMIT_INTERVAL_USEC, RATELIMIT_BURST); + r = sd_event_default(&m->event); if (r < 0) return r; - r = sntp_listen_setup(m); + sd_event_set_watchdog(m->event, true); + + sd_event_add_signal(m->event, NULL, SIGTERM, NULL, NULL); + sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL); + + r = sd_resolve_default(&m->resolve); if (r < 0) return r; - r = sntp_clock_watch_setup(m); + r = sd_resolve_attach_event(m->resolve, m->event, 0); + if (r < 0) + return r; + + r = manager_clock_watch_setup(m); if (r < 0) return r; @@ -749,44 +1000,277 @@ static int manager_new(Manager **ret) { } static void manager_free(Manager *m) { - if (!m) return; + manager_disconnect(m); + manager_flush_names(m); + + sd_event_source_unref(m->event_retry); + + sd_event_source_unref(m->network_event_source); + sd_network_monitor_unref(m->network_monitor); + + sd_resolve_unref(m->resolve); sd_event_unref(m->event); + free(m); } +int config_parse_servers( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + Manager *m = userdata; + + assert(filename); + assert(lvalue); + assert(rvalue); + + manager_flush_names(m); + manager_add_server_string(m, rvalue); + + return 0; +} + +static int manager_parse_config_file(Manager *m) { + static const char fn[] = "/etc/systemd/timesyncd.conf"; + _cleanup_fclose_ FILE *f = NULL; + int r; + + assert(m); + + f = fopen(fn, "re"); + if (!f) { + if (errno == ENOENT) + return 0; + + log_warning("Failed to open configuration file %s: %m", fn); + return -errno; + } + + r = config_parse(NULL, fn, f, "Time\0", config_item_perf_lookup, + (void*) timesyncd_gperf_lookup, false, false, m); + if (r < 0) + log_warning("Failed to parse configuration file: %s", strerror(-r)); + + return r; +} + +static bool network_is_online(void) { + _cleanup_free_ char *state = NULL; + int r; + + r = sd_network_get_operational_state(&state); + if (r >= 0 && streq("carrier", state)) + return true; + else + return false; +} + +static int manager_network_event_handler(sd_event_source *s, int fd, uint32_t revents, + void *userdata) { + Manager *m = userdata; + bool connected, online; + int r; + + assert(m); + + /* check if the machine is online */ + online = network_is_online(); + + /* check if the client is currently connected */ + connected = (m->server_socket != -1); + + if (connected && !online) { + log_info("No network connectivity. Suspending."); + manager_disconnect(m); + } else if (!connected && online) { + log_info("Network connectivity detected. Resuming."); + if (m->current_server_address) { + r = manager_begin(m); + if (r < 0) + return r; + } else { + r = manager_connect(m); + if (r < 0) + return r; + } + } + + sd_network_monitor_flush(m->network_monitor); + + return 0; +} + +static int manager_network_monitor_listen(Manager *m) { + _cleanup_event_source_unref_ sd_event_source *event_source = NULL; + _cleanup_network_monitor_unref_ sd_network_monitor *monitor = NULL; + int r, fd, events; + + r = sd_network_monitor_new(NULL, &monitor); + if (r < 0) + return r; + + fd = sd_network_monitor_get_fd(monitor); + if (fd < 0) + return fd; + + events = sd_network_monitor_get_events(monitor); + if (events < 0) + return events; + + r = sd_event_add_io(m->event, &event_source, fd, events, + &manager_network_event_handler, m); + if (r < 0) + return r; + + m->network_monitor = monitor; + m->network_event_source = event_source; + monitor = NULL; + event_source = NULL; + + return 0; +} + +static int drop_priviliges(void) { + static const cap_value_t bits[] = { + CAP_SYS_TIME, + }; + + _cleanup_cap_free_ cap_t d = NULL; + const char *name = "systemd-timesync"; + uid_t uid; + gid_t gid; + int r; + + /* Unfortunately we cannot leave privilige dropping to PID 1 + * here, since we want to run as user but want to keep te + * CAP_SYS_TIME capability. Since file capabilities have been + * introduced this cannot be done across exec() anymore, + * unless our binary has the capability configured in the file + * system, which we want to avoid. */ + + r = get_user_creds(&name, &uid, &gid, NULL, NULL); + if (r < 0) { + log_error("Cannot resolve user name %s: %s", name, strerror(-r)); + return r; + } + + if (setresgid(gid, gid, gid) < 0) { + log_error("Failed change group ID: %m"); + return -errno; + } + + if (setgroups(0, NULL) < 0) { + log_error("Failed to drop auxiliary groups list: %m"); + return -errno; + } + + if (prctl(PR_SET_KEEPCAPS, 1) < 0) { + log_error("Failed to enable keep capabilities flag: %m"); + return -errno; + } + + r = setresuid(uid, uid, uid); + if (r < 0) { + log_error("Failed change user ID: %m"); + return -errno; + } + + if (prctl(PR_SET_KEEPCAPS, 0) < 0) { + log_error("Failed to disable keep capabilities flag: %m"); + return -errno; + } + + r = capability_bounding_set_drop(~(1ULL << CAP_SYS_TIME), true); + if (r < 0) { + log_error("Failed to drop capabilities: %s", strerror(-r)); + return r; + } + + d = cap_init(); + if (!d) + return log_oom(); + + if (cap_set_flag(d, CAP_EFFECTIVE, ELEMENTSOF(bits), bits, CAP_SET) < 0 || + cap_set_flag(d, CAP_PERMITTED, ELEMENTSOF(bits), bits, CAP_SET) < 0) { + log_error("Failed to enable capabilities bits: %m"); + return -errno; + } + + if (cap_set_proc(d) < 0) { + log_error("Failed to increase capabilities: %m"); + return -errno; + } + + return 0; +} + int main(int argc, char *argv[]) { _cleanup_manager_free_ Manager *m = NULL; - const char *server; int r; + if (argc > 1) { + log_error("This program does not take arguments."); + return EXIT_FAILURE; + } + log_set_target(LOG_TARGET_AUTO); + log_set_facility(LOG_CRON); log_parse_environment(); log_open(); - r = manager_new(&m); + umask(0022); + + r = drop_priviliges(); if (r < 0) goto out; - server = "216.239.32.15"; /* time1.google.com */ + assert_se(sigprocmask_many(SIG_BLOCK, SIGTERM, SIGINT, -1) == 0); - sd_notifyf(false, - "READY=1\n" - "STATUS=Connecting to %s", server); + r = manager_new(&m); + if (r < 0) { + log_error("Failed to allocate manager: %s", strerror(-r)); + goto out; + } - r = sntp_server_connect(m, server); - if (r < 0) + manager_add_server_string(m, NTP_SERVERS); + manager_parse_config_file(m); + + r = manager_network_monitor_listen(m); + if (r < 0) { + log_error("Failed to listen to networkd events: %s", strerror(-r)); goto out; + } + + log_debug("systemd-timesyncd running as pid %lu", (unsigned long) getpid()); + sd_notify(false, "READY=1"); - sd_notifyf(false, - "STATUS=Connected to %s", server); + if (network_is_online()) { + r = manager_connect(m); + if (r < 0) + goto out; + } r = sd_event_loop(m->event); - if (r < 0) + if (r < 0) { + log_error("Failed to run event loop: %s", strerror(-r)); goto out; + } + + sd_event_get_exit_code(m->event, &r); out: + sd_notify(false, "STATUS=Shutting down..."); + return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; }