1152 lines
38 KiB
C
1152 lines
38 KiB
C
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
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/***
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This file is part of systemd.
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Copyright 2014 Kay Sievers, Lennart Poettering
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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#include <stdlib.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <string.h>
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#include <time.h>
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#include <math.h>
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#include <arpa/inet.h>
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#include <netinet/in.h>
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#include <netinet/ip.h>
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#include <sys/timerfd.h>
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#include <sys/timex.h>
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#include <sys/socket.h>
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#include <resolv.h>
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#include <sys/prctl.h>
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#include <sys/types.h>
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#include <grp.h>
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#include "missing.h"
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#include "util.h"
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#include "sparse-endian.h"
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#include "log.h"
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#include "socket-util.h"
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#include "list.h"
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#include "ratelimit.h"
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#include "strv.h"
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#include "conf-parser.h"
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#include "sd-daemon.h"
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#include "event-util.h"
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#include "network-util.h"
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#include "clock-util.h"
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#include "capability.h"
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#include "mkdir.h"
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#include "timesyncd-conf.h"
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#include "timesyncd-manager.h"
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#include "time-util.h"
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#ifndef ADJ_SETOFFSET
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#define ADJ_SETOFFSET 0x0100 /* add 'time' to current time */
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#endif
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/* expected accuracy of time synchronization; used to adjust the poll interval */
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#define NTP_ACCURACY_SEC 0.2
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/*
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* "A client MUST NOT under any conditions use a poll interval less
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* than 15 seconds."
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*/
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#define NTP_POLL_INTERVAL_MIN_SEC 32
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#define NTP_POLL_INTERVAL_MAX_SEC 2048
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/*
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* Maximum delta in seconds which the system clock is gradually adjusted
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* (slew) to approach the network time. Deltas larger that this are set by
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* letting the system time jump. The kernel's limit for adjtime is 0.5s.
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*/
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#define NTP_MAX_ADJUST 0.4
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/* NTP protocol, packet header */
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#define NTP_LEAP_PLUSSEC 1
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#define NTP_LEAP_MINUSSEC 2
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#define NTP_LEAP_NOTINSYNC 3
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#define NTP_MODE_CLIENT 3
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#define NTP_MODE_SERVER 4
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#define NTP_FIELD_LEAP(f) (((f) >> 6) & 3)
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#define NTP_FIELD_VERSION(f) (((f) >> 3) & 7)
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#define NTP_FIELD_MODE(f) ((f) & 7)
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#define NTP_FIELD(l, v, m) (((l) << 6) | ((v) << 3) | (m))
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/* Maximum acceptable root distance in seconds. */
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#define NTP_MAX_ROOT_DISTANCE 5.0
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/* Maximum number of missed replies before selecting another source. */
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#define NTP_MAX_MISSED_REPLIES 2
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/*
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* "NTP timestamps are represented as a 64-bit unsigned fixed-point number,
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* in seconds relative to 0h on 1 January 1900."
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*/
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#define OFFSET_1900_1970 2208988800UL
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#define RETRY_USEC (30*USEC_PER_SEC)
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#define RATELIMIT_INTERVAL_USEC (10*USEC_PER_SEC)
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#define RATELIMIT_BURST 10
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#define TIMEOUT_USEC (10*USEC_PER_SEC)
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struct ntp_ts {
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be32_t sec;
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be32_t frac;
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} _packed_;
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struct ntp_ts_short {
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be16_t sec;
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be16_t frac;
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} _packed_;
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struct ntp_msg {
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uint8_t field;
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uint8_t stratum;
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int8_t poll;
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int8_t precision;
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struct ntp_ts_short root_delay;
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struct ntp_ts_short root_dispersion;
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char refid[4];
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struct ntp_ts reference_time;
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struct ntp_ts origin_time;
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struct ntp_ts recv_time;
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struct ntp_ts trans_time;
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} _packed_;
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static int manager_arm_timer(Manager *m, usec_t next);
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static int manager_clock_watch_setup(Manager *m);
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static int manager_listen_setup(Manager *m);
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static void manager_listen_stop(Manager *m);
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static double ntp_ts_short_to_d(const struct ntp_ts_short *ts) {
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return be16toh(ts->sec) + (be16toh(ts->frac) / 65536.0);
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}
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static double ntp_ts_to_d(const struct ntp_ts *ts) {
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return be32toh(ts->sec) + ((double)be32toh(ts->frac) / UINT_MAX);
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}
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static double ts_to_d(const struct timespec *ts) {
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return ts->tv_sec + (1.0e-9 * ts->tv_nsec);
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}
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static int manager_timeout(sd_event_source *source, usec_t usec, void *userdata) {
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_cleanup_free_ char *pretty = NULL;
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Manager *m = userdata;
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assert(m);
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assert(m->current_server_name);
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assert(m->current_server_address);
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server_address_pretty(m->current_server_address, &pretty);
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log_info("Timed out waiting for reply from %s (%s).", strna(pretty), m->current_server_name->string);
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return manager_connect(m);
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}
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static int manager_send_request(Manager *m) {
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_cleanup_free_ char *pretty = NULL;
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struct ntp_msg ntpmsg = {
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/*
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* "The client initializes the NTP message header, sends the request
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* to the server, and strips the time of day from the Transmit
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* Timestamp field of the reply. For this purpose, all the NTP
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* header fields are set to 0, except the Mode, VN, and optional
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* Transmit Timestamp fields."
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*/
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.field = NTP_FIELD(0, 4, NTP_MODE_CLIENT),
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};
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ssize_t len;
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int r;
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assert(m);
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assert(m->current_server_name);
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assert(m->current_server_address);
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m->event_timeout = sd_event_source_unref(m->event_timeout);
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r = manager_listen_setup(m);
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if (r < 0)
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return log_warning_errno(r, "Failed to setup connection socket: %m");
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/*
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* Set transmit timestamp, remember it; the server will send that back
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* as the origin timestamp and we have an indication that this is the
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* matching answer to our request.
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*
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* The actual value does not matter, We do not care about the correct
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* NTP UINT_MAX fraction; we just pass the plain nanosecond value.
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*/
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assert_se(clock_gettime(clock_boottime_or_monotonic(), &m->trans_time_mon) >= 0);
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assert_se(clock_gettime(CLOCK_REALTIME, &m->trans_time) >= 0);
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ntpmsg.trans_time.sec = htobe32(m->trans_time.tv_sec + OFFSET_1900_1970);
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ntpmsg.trans_time.frac = htobe32(m->trans_time.tv_nsec);
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server_address_pretty(m->current_server_address, &pretty);
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len = sendto(m->server_socket, &ntpmsg, sizeof(ntpmsg), MSG_DONTWAIT, &m->current_server_address->sockaddr.sa, m->current_server_address->socklen);
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if (len == sizeof(ntpmsg)) {
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m->pending = true;
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log_debug("Sent NTP request to %s (%s).", strna(pretty), m->current_server_name->string);
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} else {
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log_debug_errno(errno, "Sending NTP request to %s (%s) failed: %m", strna(pretty), m->current_server_name->string);
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return manager_connect(m);
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}
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/* re-arm timer with increasing timeout, in case the packets never arrive back */
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if (m->retry_interval > 0) {
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if (m->retry_interval < NTP_POLL_INTERVAL_MAX_SEC * USEC_PER_SEC)
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m->retry_interval *= 2;
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} else
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m->retry_interval = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC;
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r = manager_arm_timer(m, m->retry_interval);
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if (r < 0)
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return log_error_errno(r, "Failed to rearm timer: %m");
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m->missed_replies++;
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if (m->missed_replies > NTP_MAX_MISSED_REPLIES) {
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r = sd_event_add_time(
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m->event,
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&m->event_timeout,
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clock_boottime_or_monotonic(),
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now(clock_boottime_or_monotonic()) + TIMEOUT_USEC, 0,
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manager_timeout, m);
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if (r < 0)
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return log_error_errno(r, "Failed to arm timeout timer: %m");
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}
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return 0;
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}
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static int manager_timer(sd_event_source *source, usec_t usec, void *userdata) {
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Manager *m = userdata;
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assert(m);
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return manager_send_request(m);
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}
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static int manager_arm_timer(Manager *m, usec_t next) {
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int r;
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assert(m);
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if (next == 0) {
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m->event_timer = sd_event_source_unref(m->event_timer);
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return 0;
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}
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if (m->event_timer) {
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r = sd_event_source_set_time(m->event_timer, now(clock_boottime_or_monotonic()) + next);
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if (r < 0)
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return r;
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return sd_event_source_set_enabled(m->event_timer, SD_EVENT_ONESHOT);
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}
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return sd_event_add_time(
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m->event,
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&m->event_timer,
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clock_boottime_or_monotonic(),
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now(clock_boottime_or_monotonic()) + next, 0,
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manager_timer, m);
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}
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static int manager_clock_watch(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
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Manager *m = userdata;
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assert(m);
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/* rearm timer */
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manager_clock_watch_setup(m);
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/* skip our own jumps */
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if (m->jumped) {
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m->jumped = false;
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return 0;
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}
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/* resync */
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log_info("System time changed. Resyncing.");
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m->poll_resync = true;
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return manager_send_request(m);
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}
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/* wake up when the system time changes underneath us */
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static int manager_clock_watch_setup(Manager *m) {
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struct itimerspec its = {
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.it_value.tv_sec = TIME_T_MAX
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};
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int r;
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assert(m);
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m->event_clock_watch = sd_event_source_unref(m->event_clock_watch);
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safe_close(m->clock_watch_fd);
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m->clock_watch_fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC);
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if (m->clock_watch_fd < 0)
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return log_error_errno(errno, "Failed to create timerfd: %m");
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if (timerfd_settime(m->clock_watch_fd, TFD_TIMER_ABSTIME|TFD_TIMER_CANCEL_ON_SET, &its, NULL) < 0)
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return log_error_errno(errno, "Failed to set up timerfd: %m");
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r = sd_event_add_io(m->event, &m->event_clock_watch, m->clock_watch_fd, EPOLLIN, manager_clock_watch, m);
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if (r < 0)
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return log_error_errno(r, "Failed to create clock watch event source: %m");
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return 0;
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}
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static int manager_adjust_clock(Manager *m, double offset, int leap_sec) {
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struct timex tmx = {};
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int r;
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assert(m);
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/*
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* For small deltas, tell the kernel to gradually adjust the system
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* clock to the NTP time, larger deltas are just directly set.
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*/
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if (fabs(offset) < NTP_MAX_ADJUST) {
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tmx.modes = ADJ_STATUS | ADJ_NANO | ADJ_OFFSET | ADJ_TIMECONST | ADJ_MAXERROR | ADJ_ESTERROR;
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tmx.status = STA_PLL;
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tmx.offset = offset * NSEC_PER_SEC;
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tmx.constant = log2i(m->poll_interval_usec / USEC_PER_SEC) - 4;
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tmx.maxerror = 0;
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tmx.esterror = 0;
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log_debug(" adjust (slew): %+.3f sec", offset);
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} else {
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tmx.modes = ADJ_STATUS | ADJ_NANO | ADJ_SETOFFSET;
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/* ADJ_NANO uses nanoseconds in the microseconds field */
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tmx.time.tv_sec = (long)offset;
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tmx.time.tv_usec = (offset - tmx.time.tv_sec) * NSEC_PER_SEC;
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/* the kernel expects -0.3s as {-1, 7000.000.000} */
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if (tmx.time.tv_usec < 0) {
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tmx.time.tv_sec -= 1;
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tmx.time.tv_usec += NSEC_PER_SEC;
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}
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m->jumped = true;
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log_debug(" adjust (jump): %+.3f sec", offset);
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}
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/*
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* An unset STA_UNSYNC will enable the kernel's 11-minute mode,
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* which syncs the system time periodically to the RTC.
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*
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* In case the RTC runs in local time, never touch the RTC,
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* we have no way to properly handle daylight saving changes and
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* mobile devices moving between time zones.
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*/
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if (m->rtc_local_time)
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tmx.status |= STA_UNSYNC;
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switch (leap_sec) {
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case 1:
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tmx.status |= STA_INS;
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break;
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case -1:
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tmx.status |= STA_DEL;
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break;
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}
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r = clock_adjtime(CLOCK_REALTIME, &tmx);
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if (r < 0)
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return r;
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touch("/var/lib/systemd/clock");
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m->drift_ppm = tmx.freq / 65536;
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log_debug(" status : %04i %s\n"
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" time now : %li.%03llu\n"
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" constant : %li\n"
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" offset : %+.3f sec\n"
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" freq offset : %+li (%i ppm)\n",
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tmx.status, tmx.status & STA_UNSYNC ? "unsync" : "sync",
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tmx.time.tv_sec, (unsigned long long) (tmx.time.tv_usec / NSEC_PER_MSEC),
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tmx.constant,
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(double)tmx.offset / NSEC_PER_SEC,
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tmx.freq, m->drift_ppm);
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return 0;
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}
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static bool manager_sample_spike_detection(Manager *m, double offset, double delay) {
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unsigned int i, idx_cur, idx_new, idx_min;
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double jitter;
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double j;
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assert(m);
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m->packet_count++;
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/* ignore initial sample */
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if (m->packet_count == 1)
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return false;
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/* store the current data in our samples array */
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idx_cur = m->samples_idx;
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idx_new = (idx_cur + 1) % ELEMENTSOF(m->samples);
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m->samples_idx = idx_new;
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m->samples[idx_new].offset = offset;
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m->samples[idx_new].delay = delay;
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/* calculate new jitter value from the RMS differences relative to the lowest delay sample */
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jitter = m->samples_jitter;
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for (idx_min = idx_cur, i = 0; i < ELEMENTSOF(m->samples); i++)
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if (m->samples[i].delay > 0 && m->samples[i].delay < m->samples[idx_min].delay)
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idx_min = i;
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j = 0;
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for (i = 0; i < ELEMENTSOF(m->samples); i++)
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j += pow(m->samples[i].offset - m->samples[idx_min].offset, 2);
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m->samples_jitter = sqrt(j / (ELEMENTSOF(m->samples) - 1));
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/* ignore samples when resyncing */
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if (m->poll_resync)
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return false;
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/* always accept offset if we are farther off than the round-trip delay */
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if (fabs(offset) > delay)
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return false;
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/* we need a few samples before looking at them */
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if (m->packet_count < 4)
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return false;
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/* do not accept anything worse than the maximum possible error of the best sample */
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if (fabs(offset) > m->samples[idx_min].delay)
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return true;
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/* compare the difference between the current offset to the previous offset and jitter */
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return fabs(offset - m->samples[idx_cur].offset) > 3 * jitter;
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}
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static void manager_adjust_poll(Manager *m, double offset, bool spike) {
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assert(m);
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if (m->poll_resync) {
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m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC;
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m->poll_resync = false;
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return;
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}
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/* set to minimal poll interval */
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if (!spike && fabs(offset) > NTP_ACCURACY_SEC) {
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m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC;
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return;
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}
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/* increase polling interval */
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if (fabs(offset) < NTP_ACCURACY_SEC * 0.25) {
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if (m->poll_interval_usec < NTP_POLL_INTERVAL_MAX_SEC * USEC_PER_SEC)
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m->poll_interval_usec *= 2;
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return;
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}
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/* decrease polling interval */
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if (spike || fabs(offset) > NTP_ACCURACY_SEC * 0.75) {
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if (m->poll_interval_usec > NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC)
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m->poll_interval_usec /= 2;
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return;
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}
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}
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static int manager_receive_response(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
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Manager *m = userdata;
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struct ntp_msg ntpmsg;
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struct iovec iov = {
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.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);
|
|
}
|
|
|
|
if (iov.iov_len < sizeof(struct ntp_msg)) {
|
|
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_info("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_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_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;
|
|
}
|