diff options
Diffstat (limited to 'src/timesync/timesyncd-manager.c')
| -rw-r--r-- | src/timesync/timesyncd-manager.c | 1141 |
1 files changed, 0 insertions, 1141 deletions
diff --git a/src/timesync/timesyncd-manager.c b/src/timesync/timesyncd-manager.c deleted file mode 100644 index a9e91c4d60..0000000000 --- a/src/timesync/timesyncd-manager.c +++ /dev/null @@ -1,1141 +0,0 @@ -/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ - -/*** - This file is part of systemd. - - 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 - the Free Software Foundation; either version 2.1 of the License, or - (at your option) any later version. - - systemd is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public License - along with systemd; If not, see <http://www.gnu.org/licenses/>. -***/ - -#include <stdlib.h> -#include <errno.h> -#include <time.h> -#include <math.h> -#include <netinet/in.h> -#include <netinet/ip.h> -#include <sys/timerfd.h> -#include <sys/timex.h> -#include <sys/socket.h> -#include <resolv.h> -#include <sys/types.h> - -#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 "sd-daemon.h" -#include "network-util.h" -#include "timesyncd-conf.h" -#include "timesyncd-manager.h" -#include "time-util.h" - -#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)) - -/* Maximum acceptable root distance in seconds. */ -#define NTP_MAX_ROOT_DISTANCE 5.0 - -/* Maximum number of missed replies before selecting another source. */ -#define NTP_MAX_MISSED_REPLIES 2 - -/* - * "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 UINT64_C(2208988800) - -#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; -} _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_; - -static int manager_arm_timer(Manager *m, usec_t next); -static int manager_clock_watch_setup(Manager *m); -static int manager_listen_setup(Manager *m); -static void manager_listen_stop(Manager *m); - -static double ntp_ts_short_to_d(const struct ntp_ts_short *ts) { - return be16toh(ts->sec) + (be16toh(ts->frac) / 65536.0); -} - -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 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); - - server_address_pretty(m->current_server_address, &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; - - assert(m); - assert(m->current_server_name); - assert(m->current_server_address); - - m->event_timeout = sd_event_source_unref(m->event_timeout); - - r = manager_listen_setup(m); - if (r < 0) - return log_warning_errno(r, "Failed to setup connection socket: %m"); - - /* - * Set transmit timestamp, remember it; the server will send that back - * as the origin timestamp and we have an indication that this is the - * matching answer to our request. - * - * The actual value does not matter, We do not care about the correct - * NTP UINT_MAX fraction; we just pass the plain nanosecond value. - */ - 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.frac = htobe32(m->trans_time.tv_nsec); - - server_address_pretty(m->current_server_address, &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 (%s).", strna(pretty), m->current_server_name->string); - } else { - log_debug_errno(errno, "Sending NTP request to %s (%s) failed: %m", strna(pretty), m->current_server_name->string); - return manager_connect(m); - } - - /* 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 = manager_arm_timer(m, m->retry_interval); - if (r < 0) - return log_error_errno(r, "Failed to rearm timer: %m"); - - m->missed_replies++; - if (m->missed_replies > NTP_MAX_MISSED_REPLIES) { - r = sd_event_add_time( - m->event, - &m->event_timeout, - clock_boottime_or_monotonic(), - now(clock_boottime_or_monotonic()) + TIMEOUT_USEC, 0, - manager_timeout, m); - if (r < 0) - return log_error_errno(r, "Failed to arm timeout timer: %m"); - } - - return 0; -} - -static int manager_timer(sd_event_source *source, usec_t usec, void *userdata) { - Manager *m = userdata; - - assert(m); - - return manager_send_request(m); -} - -static int manager_arm_timer(Manager *m, usec_t next) { - int r; - - assert(m); - - if (next == 0) { - m->event_timer = sd_event_source_unref(m->event_timer); - return 0; - } - - if (m->event_timer) { - r = sd_event_source_set_time(m->event_timer, now(clock_boottime_or_monotonic()) + next); - if (r < 0) - return r; - - return sd_event_source_set_enabled(m->event_timer, SD_EVENT_ONESHOT); - } - - return sd_event_add_time( - m->event, - &m->event_timer, - clock_boottime_or_monotonic(), - now(clock_boottime_or_monotonic()) + next, 0, - manager_timer, m); -} - -static int manager_clock_watch(sd_event_source *source, int fd, uint32_t revents, void *userdata) { - Manager *m = userdata; - - assert(m); - - /* rearm timer */ - manager_clock_watch_setup(m); - - /* skip our own jumps */ - if (m->jumped) { - m->jumped = false; - return 0; - } - - /* resync */ - log_debug("System time changed. Resyncing."); - m->poll_resync = true; - - return manager_send_request(m); -} - -/* wake up when the system time changes underneath us */ -static int manager_clock_watch_setup(Manager *m) { - - struct itimerspec its = { - .it_value.tv_sec = TIME_T_MAX - }; - - int r; - - assert(m); - - 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) - return log_error_errno(errno, "Failed to create timerfd: %m"); - - if (timerfd_settime(m->clock_watch_fd, TFD_TIMER_ABSTIME|TFD_TIMER_CANCEL_ON_SET, &its, NULL) < 0) - return log_error_errno(errno, "Failed to set up timerfd: %m"); - - r = sd_event_add_io(m->event, &m->event_clock_watch, m->clock_watch_fd, EPOLLIN, manager_clock_watch, m); - if (r < 0) - return log_error_errno(r, "Failed to create clock watch event source: %m"); - - return 0; -} - -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. - */ - if (fabs(offset) < NTP_MAX_ADJUST) { - tmx.modes = ADJ_STATUS | ADJ_NANO | ADJ_OFFSET | ADJ_TIMECONST | ADJ_MAXERROR | ADJ_ESTERROR; - tmx.status = STA_PLL; - 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", offset); - } else { - tmx.modes = ADJ_STATUS | ADJ_NANO | ADJ_SETOFFSET; - - /* 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", offset); - } - - /* - * An unset STA_UNSYNC will enable the kernel's 11-minute mode, - * which syncs the system time periodically to the RTC. - * - * In case the RTC runs in local time, never touch the RTC, - * we have no way to properly handle daylight saving changes and - * mobile devices moving between time zones. - */ - if (m->rtc_local_time) - tmx.status |= STA_UNSYNC; - - switch (leap_sec) { - case 1: - tmx.status |= STA_INS; - break; - case -1: - tmx.status |= STA_DEL; - break; - } - - r = clock_adjtime(CLOCK_REALTIME, &tmx); - if (r < 0) - return r; - - touch("/var/lib/systemd/clock"); - - m->drift_ppm = tmx.freq / 65536; - - log_debug(" status : %04i %s\n" - " time now : %li.%03llu\n" - " constant : %li\n" - " offset : %+.3f sec\n" - " freq offset : %+li (%i ppm)\n", - tmx.status, tmx.status & STA_UNSYNC ? "unsync" : "sync", - tmx.time.tv_sec, (unsigned long long) (tmx.time.tv_usec / NSEC_PER_MSEC), - tmx.constant, - (double)tmx.offset / NSEC_PER_SEC, - tmx.freq, m->drift_ppm); - - return 0; -} - -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 */ - if (m->packet_count == 1) - return false; - - /* store the current data in our samples array */ - idx_cur = m->samples_idx; - idx_new = (idx_cur + 1) % ELEMENTSOF(m->samples); - m->samples_idx = idx_new; - m->samples[idx_new].offset = offset; - m->samples[idx_new].delay = delay; - - /* calculate new jitter value from the RMS differences relative to the lowest delay sample */ - jitter = m->samples_jitter; - for (idx_min = idx_cur, i = 0; i < ELEMENTSOF(m->samples); i++) - if (m->samples[i].delay > 0 && m->samples[i].delay < m->samples[idx_min].delay) - idx_min = i; - - j = 0; - for (i = 0; i < ELEMENTSOF(m->samples); i++) - j += pow(m->samples[i].offset - m->samples[idx_min].offset, 2); - m->samples_jitter = sqrt(j / (ELEMENTSOF(m->samples) - 1)); - - /* ignore samples when resyncing */ - if (m->poll_resync) - return false; - - /* always accept offset if we are farther off than the round-trip delay */ - if (fabs(offset) > delay) - return false; - - /* we need a few samples before looking at them */ - if (m->packet_count < 4) - return false; - - /* do not accept anything worse than the maximum possible error of the best sample */ - if (fabs(offset) > m->samples[idx_min].delay) - return true; - - /* compare the difference between the current offset to the previous offset and jitter */ - return fabs(offset - m->samples[idx_cur].offset) > 3 * jitter; -} - -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; - return; - } - - /* set to minimal poll interval */ - if (!spike && fabs(offset) > NTP_ACCURACY_SEC) { - m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC; - return; - } - - /* increase polling interval */ - if (fabs(offset) < NTP_ACCURACY_SEC * 0.25) { - if (m->poll_interval_usec < NTP_POLL_INTERVAL_MAX_SEC * USEC_PER_SEC) - m->poll_interval_usec *= 2; - return; - } - - /* decrease polling interval */ - if (spike || fabs(offset) > NTP_ACCURACY_SEC * 0.75) { - if (m->poll_interval_usec > NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC) - m->poll_interval_usec /= 2; - return; - } -} - -static int manager_receive_response(sd_event_source *source, int fd, uint32_t revents, void *userdata) { - Manager *m = userdata; - struct ntp_msg ntpmsg; - - struct iovec iov = { - .iov_base = &ntpmsg, - .iov_len = sizeof(ntpmsg), - }; - union { - struct cmsghdr cmsghdr; - uint8_t buf[CMSG_SPACE(sizeof(struct timeval))]; - } control; - union sockaddr_union server_addr; - struct msghdr msghdr = { - .msg_iov = &iov, - .msg_iovlen = 1, - .msg_control = &control, - .msg_controllen = sizeof(control), - .msg_name = &server_addr, - .msg_namelen = sizeof(server_addr), - }; - struct cmsghdr *cmsg; - struct timespec *recv_time; - ssize_t len; - double origin, receive, trans, dest; - double delay, offset; - double root_distance; - bool spike; - int leap_sec; - int r; - - assert(source); - assert(m); - - if (revents & (EPOLLHUP|EPOLLERR)) { - log_warning("Server connection returned error."); - return manager_connect(m); - } - - len = recvmsg(fd, &msghdr, MSG_DONTWAIT); - if (len < 0) { - if (errno == EAGAIN) - return 0; - - log_warning("Error receiving message. Disconnecting."); - return manager_connect(m); - } - - /* Too short or too long packet? */ - if (iov.iov_len < sizeof(struct ntp_msg) || (msghdr.msg_flags & MSG_TRUNC)) { - log_warning("Invalid response from server. Disconnecting."); - return manager_connect(m); - } - - 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; - for (cmsg = CMSG_FIRSTHDR(&msghdr); cmsg; cmsg = CMSG_NXTHDR(&msghdr, cmsg)) { - if (cmsg->cmsg_level != SOL_SOCKET) - continue; - - switch (cmsg->cmsg_type) { - case SCM_TIMESTAMPNS: - recv_time = (struct timespec *) CMSG_DATA(cmsg); - break; - } - } - if (!recv_time) { - log_error("Invalid packet timestamp."); - return -EINVAL; - } - - if (!m->pending) { - log_debug("Unexpected reply. Ignoring."); - return 0; - } - - 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 || - be32toh(ntpmsg.origin_time.frac) != m->trans_time.tv_nsec) { - log_debug("Invalid reply; not our transmit time. Ignoring."); - return 0; - } - - 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 || - ntpmsg.stratum == 0 || ntpmsg.stratum >= 16) { - log_debug("Server is not synchronized. Disconnecting."); - return manager_connect(m); - } - - 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 manager_connect(m); - } - - root_distance = ntp_ts_short_to_d(&ntpmsg.root_delay) / 2 + ntp_ts_short_to_d(&ntpmsg.root_dispersion); - if (root_distance > NTP_MAX_ROOT_DISTANCE) { - log_debug("Server has too large root distance. Disconnecting."); - return manager_connect(m); - } - - /* valid packet */ - m->pending = false; - m->retry_interval = 0; - - /* Stop listening */ - manager_listen_stop(m); - - /* announce leap seconds */ - if (NTP_FIELD_LEAP(ntpmsg.field) & NTP_LEAP_PLUSSEC) - leap_sec = 1; - else if (NTP_FIELD_LEAP(ntpmsg.field) & NTP_LEAP_MINUSSEC) - leap_sec = -1; - else - leap_sec = 0; - - /* - * "Timestamp Name ID When Generated - * ------------------------------------------------------------ - * Originate Timestamp T1 time request sent by client - * Receive Timestamp T2 time request received by server - * Transmit Timestamp T3 time reply sent by server - * Destination Timestamp T4 time reply received by client - * - * The round-trip delay, d, and system clock offset, t, are defined as: - * d = (T4 - T1) - (T3 - T2) t = ((T2 - T1) + (T3 - T4)) / 2" - */ - origin = ts_to_d(&m->trans_time) + OFFSET_1900_1970; - receive = ntp_ts_to_d(&ntpmsg.recv_time); - trans = ntp_ts_to_d(&ntpmsg.trans_time); - dest = ts_to_d(recv_time) + OFFSET_1900_1970; - - offset = ((receive - origin) + (trans - dest)) / 2; - delay = (dest - origin) - (trans - receive); - - spike = manager_sample_spike_detection(m, offset, delay); - - manager_adjust_poll(m, offset, spike); - - log_debug("NTP response:\n" - " leap : %u\n" - " version : %u\n" - " mode : %u\n" - " stratum : %u\n" - " precision : %.6f sec (%d)\n" - " root distance: %.6f sec\n" - " reference : %.4s\n" - " origin : %.3f\n" - " receive : %.3f\n" - " transmit : %.3f\n" - " dest : %.3f\n" - " offset : %+.3f sec\n" - " delay : %+.3f sec\n" - " packet count : %"PRIu64"\n" - " jitter : %.3f%s\n" - " poll interval: " USEC_FMT "\n", - NTP_FIELD_LEAP(ntpmsg.field), - NTP_FIELD_VERSION(ntpmsg.field), - NTP_FIELD_MODE(ntpmsg.field), - ntpmsg.stratum, - exp2(ntpmsg.precision), ntpmsg.precision, - root_distance, - ntpmsg.stratum == 1 ? ntpmsg.refid : "n/a", - origin - OFFSET_1900_1970, - receive - OFFSET_1900_1970, - trans - OFFSET_1900_1970, - dest - OFFSET_1900_1970, - offset, delay, - m->packet_count, - m->samples_jitter, spike ? " spike" : "", - m->poll_interval_usec / USEC_PER_SEC); - - if (!spike) { - m->sync = true; - r = manager_adjust_clock(m, offset, leap_sec); - if (r < 0) - log_error_errno(errno, "Failed to call clock_adjtime(): %m"); - } - - log_debug("interval/delta/delay/jitter/drift " USEC_FMT "s/%+.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) - return log_error_errno(r, "Failed to rearm timer: %m"); - - return 0; -} - -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); - - if (m->server_socket >= 0) - return 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; - - r = setsockopt(m->server_socket, SOL_SOCKET, SO_TIMESTAMPNS, &on, sizeof(on)); - if (r < 0) - return -errno; - - (void) 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 void manager_listen_stop(Manager *m) { - assert(m); - - m->event_receive = sd_event_source_unref(m->event_receive); - m->server_socket = safe_close(m->server_socket); -} - -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->missed_replies = NTP_MAX_MISSED_REPLIES; - if (m->poll_interval_usec == 0) - m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC; - - server_address_pretty(m->current_server_address, &pretty); - log_debug("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_clock_watch_setup(m); - if (r < 0) - return r; - - return manager_send_request(m); -} - -void manager_set_server_name(Manager *m, ServerName *n) { - assert(m); - - if (m->current_server_name == n) - return; - - m->current_server_name = n; - m->current_server_address = NULL; - - manager_disconnect(m); - - if (n) - log_debug("Selected server %s.", n->string); -} - -void manager_set_server_address(Manager *m, ServerAddress *a) { - assert(m); - - if (m->current_server_address == a) - return; - - m->current_server_address = a; - /* If a is NULL, we are just clearing the address, without - * changing the name. Keep the existing name in that case. */ - if (a) - m->current_server_name = a->name; - - manager_disconnect(m); - - if (a) { - _cleanup_free_ char *pretty = NULL; - server_address_pretty(a, &pretty); - log_debug("Selected address %s of server %s.", strna(pretty), a->name->string); - } -} - -static int manager_resolve_handler(sd_resolve_query *q, int ret, const struct addrinfo *ai, void *userdata) { - Manager *m = userdata; - int r; - - assert(q); - assert(m); - assert(m->current_server_name); - - m->resolve_query = sd_resolve_query_unref(m->resolve_query); - - if (ret != 0) { - log_debug("Failed to resolve %s: %s", m->current_server_name->string, gai_strerror(ret)); - - /* Try next host */ - return manager_connect(m); - } - - for (; ai; ai = ai->ai_next) { - _cleanup_free_ char *pretty = NULL; - ServerAddress *a; - - assert(ai->ai_addr); - assert(ai->ai_addrlen >= offsetof(struct sockaddr, sa_data)); - - 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; - } - - r = server_address_new(m->current_server_name, &a, (const union sockaddr_union*) ai->ai_addr, ai->ai_addrlen); - if (r < 0) - return log_error_errno(r, "Failed to add server address: %m"); - - server_address_pretty(a, &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); - } - - manager_set_server_address(m, m->current_server_name->addresses); - - return manager_begin(m); -} - -static int manager_retry_connect(sd_event_source *source, usec_t usec, void *userdata) { - Manager *m = userdata; - - assert(m); - - return manager_connect(m); -} - -int manager_connect(Manager *m) { - int r; - - assert(m); - - manager_disconnect(m); - - m->event_retry = sd_event_source_unref(m->event_retry); - if (!ratelimit_test(&m->ratelimit)) { - log_debug("Slowing down attempts to contact servers."); - - r = sd_event_add_time(m->event, &m->event_retry, clock_boottime_or_monotonic(), now(clock_boottime_or_monotonic()) + RETRY_USEC, 0, manager_retry_connect, m); - if (r < 0) - return log_error_errno(r, "Failed to create retry timer: %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) - manager_set_server_address(m, m->current_server_address->addresses_next); - else { - struct addrinfo hints = { - .ai_flags = AI_NUMERICSERV|AI_ADDRCONFIG, - .ai_socktype = SOCK_DGRAM, - }; - - /* Hmm, we are through all addresses, let's look for the next host instead */ - if (m->current_server_name && m->current_server_name->names_next) - manager_set_server_name(m, m->current_server_name->names_next); - else { - ServerName *f; - bool restart = true; - - /* Our current server name list is exhausted, - * let's find the next one to iterate. First - * we try the system list, then the link list. - * After having processed the link list we - * jump back to the system list. However, if - * both lists are empty, we change to the - * fallback list. */ - if (!m->current_server_name || m->current_server_name->type == SERVER_LINK) { - f = m->system_servers; - if (!f) - f = m->link_servers; - } else { - f = m->link_servers; - if (!f) - f = m->system_servers; - else - restart = false; - } - - if (!f) - f = m->fallback_servers; - - if (!f) { - manager_set_server_name(m, NULL); - log_debug("No server found."); - return 0; - } - - if (restart && !m->exhausted_servers && m->poll_interval_usec) { - log_debug("Waiting after exhausting servers."); - r = sd_event_add_time(m->event, &m->event_retry, clock_boottime_or_monotonic(), now(clock_boottime_or_monotonic()) + m->poll_interval_usec, 0, manager_retry_connect, m); - if (r < 0) - return log_error_errno(r, "Failed to create retry timer: %m"); - - m->exhausted_servers = true; - - /* Increase the polling interval */ - if (m->poll_interval_usec < NTP_POLL_INTERVAL_MAX_SEC * USEC_PER_SEC) - m->poll_interval_usec *= 2; - - return 0; - } - - m->exhausted_servers = false; - - manager_set_server_name(m, f); - } - - /* Tell the resolver to reread /etc/resolv.conf, in - * case it changed. */ - res_init(); - - /* Flush out any previously resolved addresses */ - server_name_flush_addresses(m->current_server_name); - - log_debug("Resolving %s...", m->current_server_name->string); - - r = sd_resolve_getaddrinfo(m->resolve, &m->resolve_query, m->current_server_name->string, "123", &hints, manager_resolve_handler, m); - if (r < 0) - return log_error_errno(r, "Failed to create resolver: %m"); - - return 1; - } - - r = manager_begin(m); - if (r < 0) - return r; - - return 1; -} - -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); - - manager_listen_stop(m); - - 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."); -} - -void manager_flush_server_names(Manager *m, ServerType t) { - assert(m); - - if (t == SERVER_SYSTEM) - while (m->system_servers) - server_name_free(m->system_servers); - - if (t == SERVER_LINK) - while (m->link_servers) - server_name_free(m->link_servers); - - if (t == SERVER_FALLBACK) - while (m->fallback_servers) - server_name_free(m->fallback_servers); -} - -void manager_free(Manager *m) { - if (!m) - return; - - manager_disconnect(m); - manager_flush_server_names(m, SERVER_SYSTEM); - manager_flush_server_names(m, SERVER_LINK); - manager_flush_server_names(m, SERVER_FALLBACK); - - 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); -} - -static int manager_network_read_link_servers(Manager *m) { - _cleanup_strv_free_ char **ntp = NULL; - ServerName *n, *nx; - char **i; - int r; - - assert(m); - - r = sd_network_get_ntp(&ntp); - if (r < 0) - goto clear; - - LIST_FOREACH(names, n, m->link_servers) - n->marked = true; - - STRV_FOREACH(i, ntp) { - bool found = false; - - LIST_FOREACH(names, n, m->link_servers) - if (streq(n->string, *i)) { - n->marked = false; - found = true; - break; - } - - if (!found) { - r = server_name_new(m, NULL, SERVER_LINK, *i); - if (r < 0) - goto clear; - } - } - - LIST_FOREACH_SAFE(names, n, nx, m->link_servers) - if (n->marked) - server_name_free(n); - - return 0; - -clear: - manager_flush_server_names(m, SERVER_LINK); - return r; -} - -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); - - sd_network_monitor_flush(m->network_monitor); - - manager_network_read_link_servers(m); - - /* check if the machine is online */ - online = network_is_online(); - - /* check if the client is currently connected */ - connected = m->server_socket >= 0 || m->resolve_query || m->exhausted_servers; - - if (connected && !online) { - log_info("No network connectivity, watching for changes."); - manager_disconnect(m); - - } else if (!connected && online) { - log_info("Network configuration changed, trying to establish connection."); - - if (m->current_server_address) - r = manager_begin(m); - else - r = manager_connect(m); - if (r < 0) - return r; - } - - return 0; -} - -static int manager_network_monitor_listen(Manager *m) { - int r, fd, events; - - assert(m); - - r = sd_network_monitor_new(&m->network_monitor, NULL); - if (r < 0) - return r; - - fd = sd_network_monitor_get_fd(m->network_monitor); - if (fd < 0) - return fd; - - events = sd_network_monitor_get_events(m->network_monitor); - if (events < 0) - return events; - - r = sd_event_add_io(m->event, &m->network_event_source, fd, events, manager_network_event_handler, m); - if (r < 0) - return r; - - return 0; -} - -int manager_new(Manager **ret) { - _cleanup_(manager_freep) Manager *m = NULL; - int r; - - assert(ret); - - m = new0(Manager, 1); - if (!m) - return -ENOMEM; - - m->server_socket = m->clock_watch_fd = -1; - - RATELIMIT_INIT(m->ratelimit, RATELIMIT_INTERVAL_USEC, RATELIMIT_BURST); - - r = manager_parse_server_string(m, SERVER_FALLBACK, NTP_SERVERS); - if (r < 0) - return r; - - r = sd_event_default(&m->event); - if (r < 0) - return r; - - sd_event_add_signal(m->event, NULL, SIGTERM, NULL, NULL); - sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL); - - sd_event_set_watchdog(m->event, true); - - r = sd_resolve_default(&m->resolve); - if (r < 0) - return r; - - r = sd_resolve_attach_event(m->resolve, m->event, 0); - if (r < 0) - return r; - - r = manager_network_monitor_listen(m); - if (r < 0) - return r; - - manager_network_read_link_servers(m); - - *ret = m; - m = NULL; - - return 0; -} |