timesyncd: split up into multiple source file

The source file got much too large, hence split up the sources into
multiple per-object files, similar in style to resolved.

11 files changed, 1315 insertions, 1145 deletions

diff --git a/Makefile.am b/Makefile.am
index 12f0e9138e..9100ff6a93 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -2441,7 +2441,8 @@ libsystemd_internal_la_SOURCES = \
 	src/libsystemd/sd-login/sd-login.c \
 	src/libsystemd/sd-path/sd-path.c \
 	src/libsystemd/sd-network/sd-network.c \
-	src/libsystemd/sd-network/network-util.h
+	src/libsystemd/sd-network/network-util.h \
+	src/libsystemd/sd-network/network-util.c
 
 nodist_libsystemd_internal_la_SOURCES = \
 	src/libsystemd/libsystemd.sym \
@@ -4593,7 +4594,12 @@ EXTRA_DIST += \
 if ENABLE_TIMESYNCD
 systemd_timesyncd_SOURCES = \
 	src/timesync/timesyncd.c \
-	src/timesync/timesyncd.h
+	src/timesync/timesyncd-manager.c \
+	src/timesync/timesyncd-manager.h \
+	src/timesync/timesyncd-conf.c \
+	src/timesync/timesyncd-conf.h \
+	src/timesync/timesyncd-server.c \
+	src/timesync/timesyncd-server.h
 
 nodist_systemd_timesyncd_SOURCES = \
 	src/timesync/timesyncd-gperf.c
diff --git a/src/libsystemd/sd-network/network-util.c b/src/libsystemd/sd-network/network-util.c
new file mode 100644
index 0000000000..48958e8a9f
--- /dev/null
+++ b/src/libsystemd/sd-network/network-util.c
@@ -0,0 +1,37 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2014 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 "strv.h"
+#include "network-util.h"
+
+bool network_is_online(void) {
+        _cleanup_free_ char *state = NULL;
+        int r;
+
+        r = sd_network_get_operational_state(&state);
+        if (r < 0) /* if we don't know anything, we consider the system online */
+                return true;
+
+        if (STR_IN_SET(state, "routable", "degraded"))
+                return true;
+
+        return false;
+}
diff --git a/src/libsystemd/sd-network/network-util.h b/src/libsystemd/sd-network/network-util.h
index 139efc7677..02bd545526 100644
--- a/src/libsystemd/sd-network/network-util.h
+++ b/src/libsystemd/sd-network/network-util.h
@@ -25,5 +25,6 @@
 #include "sd-network.h"
 
 DEFINE_TRIVIAL_CLEANUP_FUNC(sd_network_monitor*, sd_network_monitor_unref);
-
 #define _cleanup_network_monitor_unref_ _cleanup_(sd_network_monitor_unrefp)
+
+bool network_is_online(void);
diff --git a/src/timesync/timesyncd-conf.c b/src/timesync/timesyncd-conf.c
new file mode 100644
index 0000000000..5ec907bb41
--- /dev/null
+++ b/src/timesync/timesyncd-conf.c
@@ -0,0 +1,49 @@
+/*-*- 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 "timesyncd-manager.h"
+#include "timesyncd-conf.h"
+
+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);
+
+        if (isempty(rvalue))
+                manager_flush_names(m);
+
+        manager_add_server_string(m, rvalue);
+
+        return 0;
+}
diff --git a/src/timesync/timesyncd-conf.h b/src/timesync/timesyncd-conf.h
new file mode 100644
index 0000000000..2102599e92
--- /dev/null
+++ b/src/timesync/timesyncd-conf.h
@@ -0,0 +1,28 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  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 "conf-parser.h"
+
+const struct ConfigPerfItem* timesyncd_gperf_lookup(const char *key, unsigned length);
+
+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);
diff --git a/src/timesync/timesyncd-gperf.gperf b/src/timesync/timesyncd-gperf.gperf
index 887dc68b50..b97eec83e1 100644
--- a/src/timesync/timesyncd-gperf.gperf
+++ b/src/timesync/timesyncd-gperf.gperf
@@ -1,7 +1,7 @@
 %{
 #include <stddef.h>
 #include "conf-parser.h"
-#include "timesyncd.h"
+#include "timesyncd-conf.h"
 %}
 struct ConfigPerfItem;
 %null_strings
diff --git a/src/timesync/timesyncd-manager.c b/src/timesync/timesyncd-manager.c
new file mode 100644
index 0000000000..c93937e7be
--- /dev/null
+++ b/src/timesync/timesyncd-manager.c
@@ -0,0 +1,1083 @@
+/*-*- 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 <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+#include <time.h>
+#include <math.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <sys/timerfd.h>
+#include <sys/timex.h>
+#include <sys/socket.h>
+#include <resolv.h>
+#include <sys/prctl.h>
+#include <sys/types.h>
+#include <grp.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 "conf-parser.h"
+#include "sd-daemon.h"
+#include "event-util.h"
+#include "network-util.h"
+#include "clock-util.h"
+#include "capability.h"
+#include "mkdir.h"
+#include "timesyncd-conf.h"
+#include "timesyncd-manager.h"
+
+#define TIME_T_MAX (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
+
+#ifndef ADJ_SETOFFSET
+#define ADJ_SETOFFSET                   0x0100  /* add 'time' to current time */
+#endif
+
+/* expected accuracy of time synchronization; used to adjust the poll interval */
+#define NTP_ACCURACY_SEC                0.2
+
+/*
+ * "A client MUST NOT under any conditions use a poll interval less
+ * than 15 seconds."
+ */
+#define NTP_POLL_INTERVAL_MIN_SEC       32
+#define NTP_POLL_INTERVAL_MAX_SEC       2048
+
+/*
+ * Maximum delta in seconds which the system clock is gradually adjusted
+ * (slew) to approach the network time. Deltas larger that this are set by
+ * letting the system time jump. The kernel's limit for adjtime is 0.5s.
+ */
+#define NTP_MAX_ADJUST                  0.4
+
+/* NTP protocol, packet header */
+#define NTP_LEAP_PLUSSEC                1
+#define NTP_LEAP_MINUSSEC               2
+#define NTP_LEAP_NOTINSYNC              3
+#define NTP_MODE_CLIENT                 3
+#define NTP_MODE_SERVER                 4
+#define NTP_FIELD_LEAP(f)               (((f) >> 6) & 3)
+#define NTP_FIELD_VERSION(f)            (((f) >> 3) & 7)
+#define NTP_FIELD_MODE(f)               ((f) & 7)
+#define NTP_FIELD(l, v, m)              (((l) << 6) | ((v) << 3) | (m))
+
+/*
+ * "NTP timestamps are represented as a 64-bit unsigned fixed-point number,
+ * in seconds relative to 0h on 1 January 1900."
+ */
+#define OFFSET_1900_1970        2208988800UL
+
+#define RETRY_USEC (30*USEC_PER_SEC)
+#define RATELIMIT_INTERVAL_USEC (10*USEC_PER_SEC)
+#define RATELIMIT_BURST 10
+
+#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 double ntp_ts_to_d(const struct ntp_ts *ts) {
+        return be32toh(ts->sec) + ((double)be32toh(ts->frac) / UINT_MAX);
+}
+
+static double ts_to_d(const struct timespec *ts) {
+        return ts->tv_sec + (1.0e-9 * ts->tv_nsec);
+}
+
+static double tv_to_d(const struct timeval *tv) {
+        return tv->tv_sec + (1.0e-6 * tv->tv_usec);
+}
+
+static double square(double d) {
+        return d * d;
+}
+
+static int manager_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);
+
+        /*
+         * 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("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) {
+                log_error("Failed to rearm timer: %s", strerror(-r));
+                return r;
+        }
+
+        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) {
+                log_error("Failed to arm timeout timer: %s", strerror(-r));
+                return r;
+        }
+
+        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);
+        assert(m->event_receive);
+
+        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_info("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) {
+                log_error("Failed to create timerfd: %m");
+                return -errno;
+        }
+
+        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;
+        }
+
+        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;
+        }
+
+        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\n", 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\n", 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 += square(m->samples[i].offset - m->samples[idx_min].offset);
+        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 now_ts;
+        struct timeval *recv_time;
+        ssize_t len;
+        double origin, receive, trans, dest;
+        double delay, offset;
+        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_TIMESTAMP:
+                        recv_time = (struct timeval *) CMSG_DATA(cmsg);
+                        break;
+                }
+        }
+        if (!recv_time) {
+                log_error("Invalid packet timestamp.");
+                return -EINVAL;
+        }
+
+        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) {
+                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) {
+                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);
+        }
+
+        /* valid packet */
+        m->pending = false;
+        m->retry_interval = 0;
+
+        /* 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"
+         */
+        assert_se(clock_gettime(clock_boottime_or_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);
+        dest = tv_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"
+                  "  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,
+                  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("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) {
+                log_error("Failed to rearm timer: %s", strerror(-r));
+                return r;
+        }
+
+        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);
+
+        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;
+
+        r = setsockopt(m->server_socket, SOL_SOCKET, SO_TIMESTAMP, &on, sizeof(on));
+        if (r < 0)
+                return -errno;
+
+        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;
+
+        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_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 server_name_flush_addresses(ServerName *n) {
+        ServerAddress *a;
+
+        assert(n);
+
+        while ((a = n->addresses)) {
+                LIST_REMOVE(addresses, n->addresses, a);
+                free(a);
+        }
+}
+
+void manager_flush_names(Manager *m) {
+        ServerName *n;
+
+        assert(m);
+
+        while ((n = m->servers)) {
+                LIST_REMOVE(names, m->servers, n);
+                free(n->string);
+                server_name_flush_addresses(n);
+                free(n);
+        }
+}
+
+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_debug("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);
+}
+
+int manager_connect(Manager *m) {
+
+        struct addrinfo hints = {
+                .ai_flags = AI_NUMERICSERV|AI_ADDRCONFIG,
+                .ai_socktype = SOCK_DGRAM,
+        };
+        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, m);
+                if (r < 0) {
+                        log_error("Failed to create retry timer: %s", strerror(-r));
+                        return r;
+                }
+
+                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;
+
+        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;
+}
+
+int manager_add_server_string(Manager *m, const char *string) {
+        const char *word, *state;
+        size_t l;
+        int r;
+
+        assert(m);
+        assert(string);
+
+        FOREACH_WORD_QUOTED(word, l, string, state) {
+                char t[l+1];
+
+                memcpy(t, word, 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));
+        }
+        if (!isempty(state))
+                log_warning("Trailing garbage at the end of server list, ignoring.");
+
+        return 0;
+}
+
+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.");
+}
+
+
+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 manager_parse_config_file(Manager *m) {
+        assert(m);
+
+        return config_parse(NULL, "/etc/systemd/timesyncd.conf", NULL,
+                            "Time\0",
+                            config_item_perf_lookup, timesyncd_gperf_lookup,
+                            false, false, true, m);
+}
+
+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);
+
+        /* check if the machine is online */
+        online = network_is_online();
+
+        /* check if the client is currently connected */
+        connected = m->server_socket >= 0;
+
+        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_add_server_string(m, 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;
+
+        *ret = m;
+        m = NULL;
+
+        return 0;
+}
diff --git a/src/timesync/timesyncd.h b/src/timesync/timesyncd-manager.h
index e723404d82..e6dd711f48 100644
--- a/src/timesync/timesyncd.h
+++ b/src/timesync/timesyncd-manager.h
@@ -1,5 +1,7 @@
 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
 
+#pragma once
+
 /***
   This file is part of systemd.
 
@@ -19,38 +21,23 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-#include "list.h"
-#include "socket-util.h"
-#include "ratelimit.h"
 #include "sd-event.h"
 #include "sd-resolve.h"
 #include "sd-network.h"
+#include "list.h"
+#include "socket-util.h"
+#include "ratelimit.h"
+#include "timesyncd-server.h"
 
 typedef struct Manager Manager;
-typedef struct ServerAddress ServerAddress;
-typedef struct ServerName ServerName;
-
-struct ServerAddress {
-        union sockaddr_union sockaddr;
-        socklen_t socklen;
-        LIST_FIELDS(ServerAddress, addresses);
-};
-
-struct ServerName {
-        char *string;
-        LIST_HEAD(ServerAddress, addresses);
-        LIST_FIELDS(ServerName, names);
-};
-
-static inline int server_address_pretty(ServerAddress *a, char **pretty) {
-        return sockaddr_pretty(&a->sockaddr.sa, a->socklen, true, pretty);
-}
 
 struct Manager {
         sd_event *event;
         sd_resolve *resolve;
 
+        LIST_HEAD(ServerName, link_servers);
         LIST_HEAD(ServerName, servers);
+        LIST_HEAD(ServerName, fallback_servers);
 
         RateLimit ratelimit;
 
@@ -102,6 +89,13 @@ struct Manager {
         bool rtc_local_time;
 };
 
-const struct ConfigPerfItem* timesyncd_gperf_lookup(const char *key, unsigned length);
+int manager_new(Manager **ret);
+void manager_free(Manager *m);
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free);
 
-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);
+int manager_parse_config_file(Manager *m);
+int manager_add_server_string(Manager *m, const char *string);
+void manager_flush_names(Manager *m);
+int manager_connect(Manager *m);
+void manager_disconnect(Manager *m);
diff --git a/src/timesync/timesyncd-server.c b/src/timesync/timesyncd-server.c
new file mode 100644
index 0000000000..e3cb1bf1f2
--- /dev/null
+++ b/src/timesync/timesyncd-server.c
@@ -0,0 +1,22 @@
+/*-*- 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 "timesyncd-server.h"
diff --git a/src/timesync/timesyncd-server.h b/src/timesync/timesyncd-server.h
new file mode 100644
index 0000000000..a1312bfe0c
--- /dev/null
+++ b/src/timesync/timesyncd-server.h
@@ -0,0 +1,44 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  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/>.
+***/
+
+typedef struct ServerAddress ServerAddress;
+typedef struct ServerName ServerName;
+
+#include "socket-util.h"
+#include "list.h"
+
+struct ServerAddress {
+        union sockaddr_union sockaddr;
+        socklen_t socklen;
+        LIST_FIELDS(ServerAddress, addresses);
+};
+
+struct ServerName {
+        char *string;
+        LIST_HEAD(ServerAddress, addresses);
+        LIST_FIELDS(ServerName, names);
+};
+
+static inline int server_address_pretty(ServerAddress *a, char **pretty) {
+        return sockaddr_pretty(&a->sockaddr.sa, a->socklen, true, pretty);
+}
diff --git a/src/timesync/timesyncd.c b/src/timesync/timesyncd.c
index 500f83f673..351bfd0236 100644
--- a/src/timesync/timesyncd.c
+++ b/src/timesync/timesyncd.c
@@ -19,138 +19,15 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-#include <stdlib.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <string.h>
-#include <time.h>
-#include <math.h>
-#include <arpa/inet.h>
-#include <netinet/in.h>
-#include <netinet/ip.h>
-#include <sys/timerfd.h>
-#include <sys/timex.h>
-#include <sys/socket.h>
-#include <resolv.h>
-#include <sys/prctl.h>
-#include <sys/types.h>
-#include <grp.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 "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 "clock-util.h"
-#include "capability.h"
 #include "mkdir.h"
-#include "timesyncd.h"
-
-#define TIME_T_MAX (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
-
-#ifndef ADJ_SETOFFSET
-#define ADJ_SETOFFSET                   0x0100  /* add 'time' to current time */
-#endif
-
-/* expected accuracy of time synchronization; used to adjust the poll interval */
-#define NTP_ACCURACY_SEC                0.2
-
-/*
- * "A client MUST NOT under any conditions use a poll interval less
- * than 15 seconds."
- */
-#define NTP_POLL_INTERVAL_MIN_SEC       32
-#define NTP_POLL_INTERVAL_MAX_SEC       2048
-
-/*
- * Maximum delta in seconds which the system clock is gradually adjusted
- * (slew) to approach the network time. Deltas larger that this are set by
- * letting the system time jump. The kernel's limit for adjtime is 0.5s.
- */
-#define NTP_MAX_ADJUST                  0.4
-
-/* NTP protocol, packet header */
-#define NTP_LEAP_PLUSSEC                1
-#define NTP_LEAP_MINUSSEC               2
-#define NTP_LEAP_NOTINSYNC              3
-#define NTP_MODE_CLIENT                 3
-#define NTP_MODE_SERVER                 4
-#define NTP_FIELD_LEAP(f)               (((f) >> 6) & 3)
-#define NTP_FIELD_VERSION(f)            (((f) >> 3) & 7)
-#define NTP_FIELD_MODE(f)               ((f) & 7)
-#define NTP_FIELD(l, v, m)              (((l) << 6) | ((v) << 3) | (m))
-
-/*
- * "NTP timestamps are represented as a 64-bit unsigned fixed-point number,
- * in seconds relative to 0h on 1 January 1900."
- */
-#define OFFSET_1900_1970        2208988800UL
-
-#define RETRY_USEC (30*USEC_PER_SEC)
-#define RATELIMIT_INTERVAL_USEC (10*USEC_PER_SEC)
-#define RATELIMIT_BURST 10
-
-#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 void manager_free(Manager *m);
-DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free);
-#define _cleanup_manager_free_ _cleanup_(manager_freep)
-
-static int manager_arm_timer(Manager *m, usec_t next);
-static int manager_clock_watch_setup(Manager *m);
-static int manager_connect(Manager *m);
-static void manager_disconnect(Manager *m);
-
-static double ntp_ts_to_d(const struct ntp_ts *ts) {
-        return be32toh(ts->sec) + ((double)be32toh(ts->frac) / UINT_MAX);
-}
-
-static double ts_to_d(const struct timespec *ts) {
-        return ts->tv_sec + (1.0e-9 * ts->tv_nsec);
-}
-
-static double tv_to_d(const struct timeval *tv) {
-        return tv->tv_sec + (1.0e-6 * tv->tv_usec);
-}
+#include "capability.h"
+#include "clock-util.h"
+#include "network-util.h"
 
-static double square(double d) {
-        return d * d;
-}
+#include "timesyncd-manager.h"
+#include "timesyncd-conf.h"
 
 static int load_clock_timestamp(uid_t uid, gid_t gid) {
         _cleanup_close_ int fd = -1;
@@ -202,985 +79,13 @@ static int load_clock_timestamp(uid_t uid, gid_t gid) {
         return 0;
 }
 
-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);
-
-        /*
-         * 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("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) {
-                log_error("Failed to rearm timer: %s", strerror(-r));
-                return r;
-        }
-
-        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) {
-                log_error("Failed to arm timeout timer: %s", strerror(-r));
-                return r;
-        }
-
-        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);
-        assert(m->event_receive);
-
-        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_info("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) {
-                log_error("Failed to create timerfd: %m");
-                return -errno;
-        }
-
-        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;
-        }
-
-        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;
-        }
-
-        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\n", 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\n", 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 += square(m->samples[i].offset - m->samples[idx_min].offset);
-        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 now_ts;
-        struct timeval *recv_time;
-        ssize_t len;
-        double origin, receive, trans, dest;
-        double delay, offset;
-        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_TIMESTAMP:
-                        recv_time = (struct timeval *) CMSG_DATA(cmsg);
-                        break;
-                }
-        }
-        if (!recv_time) {
-                log_error("Invalid packet timestamp.");
-                return -EINVAL;
-        }
-
-        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) {
-                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) {
-                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);
-        }
-
-        /* valid packet */
-        m->pending = false;
-        m->retry_interval = 0;
-
-        /* 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"
-         */
-        assert_se(clock_gettime(clock_boottime_or_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);
-        dest = tv_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"
-                  "  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,
-                  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("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) {
-                log_error("Failed to rearm timer: %s", strerror(-r));
-                return r;
-        }
-
-        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);
-
-        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;
-
-        r = setsockopt(m->server_socket, SOL_SOCKET, SO_TIMESTAMP, &on, sizeof(on));
-        if (r < 0)
-                return -errno;
-
-        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;
-
-        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_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 server_name_flush_addresses(ServerName *n) {
-        ServerAddress *a;
-
-        assert(n);
-
-        while ((a = n->addresses)) {
-                LIST_REMOVE(addresses, n->addresses, a);
-                free(a);
-        }
-}
-
-static void manager_flush_names(Manager *m) {
-        ServerName *n;
-
-        assert(m);
-
-        while ((n = m->servers)) {
-                LIST_REMOVE(names, m->servers, n);
-                free(n->string);
-                server_name_flush_addresses(n);
-                free(n);
-        }
-}
-
-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_debug("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;
-
-        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, m);
-                if (r < 0) {
-                        log_error("Failed to create retry timer: %s", strerror(-r));
-                        return r;
-                }
-
-                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;
-
-        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) {
-        const char *word, *state;
-        size_t l;
-        int r;
-
-        assert(m);
-        assert(string);
-
-        FOREACH_WORD_QUOTED(word, l, string, state) {
-                char t[l+1];
-
-                memcpy(t, word, 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));
-        }
-        if (!isempty(state))
-                log_warning("Trailing garbage at the end of server list, ignoring.");
-
-        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;
-
-        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 = sd_event_default(&m->event);
-        if (r < 0)
-                return r;
-
-        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 = sd_resolve_attach_event(m->resolve, m->event, 0);
-        if (r < 0)
-                return r;
-
-        *ret = m;
-        m = NULL;
-
-        return 0;
-}
-
-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) {
-        assert(m);
-
-        return config_parse(NULL, "/etc/systemd/timesyncd.conf", NULL,
-                            "Time\0",
-                            config_item_perf_lookup, timesyncd_gperf_lookup,
-                            false, false, true, m);
-}
-
-static bool network_is_online(void) {
-        _cleanup_free_ char *state = NULL;
-        int r;
-
-        r = sd_network_get_operational_state(&state);
-        if (r < 0) /* if we don't know anything, we consider the system online */
-                return true;
-
-        if (STR_IN_SET(state, "routable", "degraded"))
-                return true;
-
-        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);
-
-        sd_network_monitor_flush(m->network_monitor);
-
-        /* check if the machine is online */
-        online = network_is_online();
-
-        /* check if the client is currently connected */
-        connected = m->server_socket >= 0;
-
-        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 main(int argc, char *argv[]) {
-        _cleanup_manager_free_ Manager *m = NULL;
+        _cleanup_(manager_freep) Manager *m = NULL;
         const char *user = "systemd-timesync";
         uid_t uid;
         gid_t gid;
         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();
@@ -1188,26 +93,32 @@ int main(int argc, char *argv[]) {
 
         umask(0022);
 
+        if (argc != 1) {
+                log_error("This program does not take arguments.");
+                r = -EINVAL;
+                goto finish;
+        }
+
         r = get_user_creds(&user, &uid, &gid, NULL, NULL);
         if (r < 0) {
                 log_error("Cannot resolve user name %s: %s", user, strerror(-r));
-                return r;
+                goto finish;
         }
 
         r = load_clock_timestamp(uid, gid);
         if (r < 0)
-                goto out;
+                goto finish;
 
         r = drop_privileges(uid, gid, (1ULL << CAP_SYS_TIME));
         if (r < 0)
-                goto out;
+                goto finish;
 
         assert_se(sigprocmask_many(SIG_BLOCK, SIGTERM, SIGINT, -1) == 0);
 
         r = manager_new(&m);
         if (r < 0) {
                 log_error("Failed to allocate manager: %s", strerror(-r));
-                goto out;
+                goto finish;
         }
 
         if (clock_is_localtime() > 0) {
@@ -1216,14 +127,9 @@ int main(int argc, char *argv[]) {
                 m->rtc_local_time = true;
         }
 
-        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;
-        }
+        r = manager_parse_config_file(m);
+        if (r < 0)
+                log_warning("Failed to parse configuration file: %s", strerror(-r));
 
         log_debug("systemd-timesyncd running as pid %lu", (unsigned long) getpid());
         sd_notify(false, "READY=1");
@@ -1231,22 +137,22 @@ int main(int argc, char *argv[]) {
         if (network_is_online()) {
                 r = manager_connect(m);
                 if (r < 0)
-                        goto out;
+                        goto finish;
         }
 
         r = sd_event_loop(m->event);
         if (r < 0) {
                 log_error("Failed to run event loop: %s", strerror(-r));
-                goto out;
+                goto finish;
         }
 
-        sd_event_get_exit_code(m->event, &r);
-
         /* if we got an authoritative time, store it in the file system */
         if (m->sync)
                 touch("/var/lib/systemd/clock");
 
-out:
+        sd_event_get_exit_code(m->event, &r);
+
+finish:
         sd_notify(false, "STATUS=Shutting down...");
 
         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;