New upstream version 1.29.90 upstream/1.29.90

10 files changed, 5027 insertions, 0 deletions

diff --git a/src/core/dns/nm-dns-dnsmasq.c b/src/core/dns/nm-dns-dnsmasq.c
new file mode 100644
index 00000000..dcff98e9
--- /dev/null
+++ b/src/core/dns/nm-dns-dnsmasq.c
@@ -0,0 +1,1203 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2010 Dan Williams <dcbw@redhat.com>
+ */
+
+#include "src/core/nm-default-daemon.h"
+
+#include "nm-dns-dnsmasq.h"
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <arpa/inet.h>
+#include <sys/stat.h>
+#include <linux/if.h>
+
+#include "nm-glib-aux/nm-dbus-aux.h"
+#include "nm-core-internal.h"
+#include "platform/nm-platform.h"
+#include "nm-utils.h"
+#include "nm-ip4-config.h"
+#include "nm-ip6-config.h"
+#include "nm-dbus-manager.h"
+#include "NetworkManagerUtils.h"
+
+#define PIDFILE NMRUNDIR "/dnsmasq.pid"
+#define CONFDIR NMCONFDIR "/dnsmasq.d"
+
+#define DNSMASQ_DBUS_SERVICE "org.freedesktop.NetworkManager.dnsmasq"
+#define DNSMASQ_DBUS_PATH    "/uk/org/thekelleys/dnsmasq"
+
+#define RATELIMIT_INTERVAL_MSEC 30000
+#define RATELIMIT_BURST         5
+
+#define _NMLOG_DOMAIN LOGD_DNS
+
+/*****************************************************************************/
+
+#define _NMLOG(level, ...) __NMLOG_DEFAULT(level, _NMLOG_DOMAIN, "dnsmasq", __VA_ARGS__)
+
+#define WAIT_MSEC_AFTER_SIGTERM 1000
+G_STATIC_ASSERT(WAIT_MSEC_AFTER_SIGTERM <= NM_SHUTDOWN_TIMEOUT_MS);
+
+#define WAIT_MSEC_AFTER_SIGKILL 400
+G_STATIC_ASSERT(WAIT_MSEC_AFTER_SIGKILL + 100 <= NM_SHUTDOWN_TIMEOUT_MS_WATCHDOG);
+
+typedef void (*GlPidSpawnAsyncNotify)(GCancellable *cancellable,
+                                      GPid          pid,
+                                      const int *   p_exit_code,
+                                      GError *      error,
+                                      gpointer      notify_user_data);
+
+typedef struct {
+    NMShutdownWaitObjHandle *shutdown_wait_handle;
+    guint64                  p_start_time;
+    gint64                   started_at;
+    GPid                     pid;
+    bool                     sigkilled : 1;
+} GlPidKillExternalData;
+
+typedef struct {
+    const char *          dm_binary;
+    GlPidSpawnAsyncNotify notify;
+    gpointer              notify_user_data;
+    GCancellable *        cancellable;
+} GlPidSpawnAsyncData;
+
+static struct {
+    GlPidKillExternalData *kill_external_data;
+
+    GlPidSpawnAsyncData *spawn_data;
+
+    NMShutdownWaitObjHandle *terminate_handle;
+
+    GPid pid;
+
+    guint terminate_timeout_id;
+
+    guint watch_id;
+
+    /* whether the external process (with the pid from PIDFILE) was already killed.
+     * This only happens once, once we do that, we remember to not do it again.
+     * The reason is that later one, when we want to kill the process it's a
+     * child process. So, we wait for the exit code. */
+    bool kill_external_done : 1;
+
+    bool terminate_sigkill : 1;
+} gl_pid;
+
+/*****************************************************************************/
+
+static void _gl_pid_spawn_next_step(void);
+static void _gl_pid_spawn_cancelled_cb(GCancellable *cancellable, GlPidSpawnAsyncData *sdata);
+
+/*****************************************************************************/
+
+static gboolean
+_gl_pid_unlink_pidfile(gboolean do_unlink)
+{
+    int errsv;
+
+    if (do_unlink) {
+        if (unlink(PIDFILE) == 0)
+            _LOGD("spawn: delete PID file %s", PIDFILE);
+        else {
+            errsv = errno;
+            if (errsv != ENOENT)
+                _LOGD("spawn: delete PID file %s failed: %s (%d)",
+                      PIDFILE,
+                      nm_strerror_native(errsv),
+                      errsv);
+        }
+    }
+    return TRUE;
+}
+
+static gboolean
+_gl_pid_kill_external_timeout_cb(gpointer user_data)
+{
+    guint64 p_start_time;
+    char    p_state = '\0';
+    gint64  now;
+
+    p_start_time = nm_utils_get_start_time_for_pid(gl_pid.kill_external_data->pid, &p_state, NULL);
+    if (p_start_time == 0 || p_start_time != gl_pid.kill_external_data->p_start_time
+        || nm_utils_process_state_is_dead(p_state)) {
+        _LOGD("spawn: process %" G_PID_FORMAT " from pidfile %s is gone",
+              gl_pid.kill_external_data->pid,
+              PIDFILE);
+        goto process_gone;
+    }
+
+    now = nm_utils_get_monotonic_timestamp_msec();
+
+    if (gl_pid.kill_external_data->started_at + WAIT_MSEC_AFTER_SIGTERM < now) {
+        if (!gl_pid.kill_external_data->sigkilled) {
+            _LOGD("spawn: send SIGKILL to process %" G_PID_FORMAT " from pidfile %s",
+                  gl_pid.kill_external_data->pid,
+                  PIDFILE);
+            gl_pid.kill_external_data->sigkilled = TRUE;
+            kill(gl_pid.kill_external_data->pid, SIGKILL);
+        } else if (gl_pid.kill_external_data->started_at + WAIT_MSEC_AFTER_SIGTERM
+                       + WAIT_MSEC_AFTER_SIGKILL
+                   < now) {
+            _LOGW("spawn: process %" G_PID_FORMAT
+                  " from pidfile %s is still here after trying to kill it. Wait no longer",
+                  gl_pid.kill_external_data->pid,
+                  PIDFILE);
+            goto process_gone;
+        }
+    }
+
+    return G_SOURCE_CONTINUE;
+
+process_gone:
+    nm_shutdown_wait_obj_unregister(gl_pid.kill_external_data->shutdown_wait_handle);
+    g_slice_free(GlPidKillExternalData, g_steal_pointer(&gl_pid.kill_external_data));
+
+    _gl_pid_unlink_pidfile(TRUE);
+
+    _gl_pid_spawn_next_step();
+
+    return G_SOURCE_REMOVE;
+}
+
+static gboolean
+_gl_pid_kill_external(void)
+{
+    gs_free char *contents         = NULL;
+    gs_free char *cmdline_contents = NULL;
+    gs_free_error GError *error    = NULL;
+    gint64                pid64;
+    GPid                  pid          = 0;
+    guint64               p_start_time = 0;
+    char                  proc_path[256];
+    gboolean              do_kill   = FALSE;
+    char                  p_state   = '\0';
+    gboolean              do_unlink = TRUE;
+    int                   errsv;
+
+    if (gl_pid.kill_external_done) {
+        if (gl_pid.kill_external_data) {
+            _LOGD("spawn: waiting for external process %" G_PID_FORMAT " from pidfile %s quit",
+                  gl_pid.kill_external_data->pid,
+                  PIDFILE);
+            return FALSE;
+        }
+        return TRUE;
+    }
+
+    if (!g_file_get_contents(PIDFILE, &contents, NULL, &error)) {
+        if (g_error_matches(error, G_FILE_ERROR, G_FILE_ERROR_NOENT))
+            do_unlink = FALSE;
+        _LOGD("spawn: failure to read pidfile %s: %s", PIDFILE, error->message);
+        g_clear_error(&error);
+        goto handle_kill;
+    }
+
+    pid64 = _nm_utils_ascii_str_to_int64(contents, 10, 2, G_MAXINT64, -1);
+    if (pid64 == -1 || (pid = (GPid) pid64) != pid64) {
+        _LOGD("spawn: pidfile %s does not contain a valid process identifier", PIDFILE);
+        goto handle_kill;
+    }
+
+    G_STATIC_ASSERT_EXPR(sizeof(pid) == sizeof(pid_t));
+
+    p_start_time = nm_utils_get_start_time_for_pid(pid, &p_state, NULL);
+    if (p_start_time == 0) {
+        _LOGD("spawn: process %" G_PID_FORMAT " from pidfile %s seems to no longer exist",
+              pid,
+              PIDFILE);
+        goto handle_kill;
+    }
+
+    nm_sprintf_buf(proc_path, "/proc/%" G_PID_FORMAT "/cmdline", pid);
+    if (!g_file_get_contents(proc_path, &cmdline_contents, NULL, NULL)) {
+        _LOGD("spawn: process %" G_PID_FORMAT " from pidfile %s seems to no longer exist",
+              pid,
+              PIDFILE);
+        goto handle_kill;
+    }
+
+    if (!strstr(cmdline_contents, "/dnsmasq")) {
+        _LOGD("spawn: process %" G_PID_FORMAT
+              " from pidfile %s seems to no longer to be a dnsmasq process",
+              pid,
+              PIDFILE);
+        goto handle_kill;
+    }
+
+    do_kill = TRUE;
+
+handle_kill:
+
+    gl_pid.kill_external_done = TRUE;
+
+    if (!do_kill)
+        return _gl_pid_unlink_pidfile(do_unlink);
+
+    if (nm_utils_process_state_is_dead(p_state)) {
+        _LOGD("spawn: process %" G_PID_FORMAT " from pidfile %s is already a zombie", pid, PIDFILE);
+        return _gl_pid_unlink_pidfile(do_unlink);
+    }
+
+    if (kill(pid, SIGTERM) != 0) {
+        errsv = errno;
+        if (errsv == ESRCH)
+            _LOGD("spawn: process %" G_PID_FORMAT " from pidfile %s no longer exists",
+                  pid,
+                  PIDFILE);
+        else
+            _LOGD("spawn: process %" G_PID_FORMAT " from pidfile %s failed with \"%s\" (%d)",
+                  pid,
+                  PIDFILE,
+                  nm_strerror_native(errsv),
+                  errsv);
+        return _gl_pid_unlink_pidfile(do_unlink);
+    }
+
+    _LOGD("spawn: waiting for process %" G_PID_FORMAT " from pidfile %s to terminate after SIGTERM",
+          pid,
+          PIDFILE);
+
+    gl_pid.kill_external_data  = g_slice_new(GlPidKillExternalData);
+    *gl_pid.kill_external_data = (GlPidKillExternalData){
+        .shutdown_wait_handle = nm_shutdown_wait_obj_register_handle_full(
+            g_strdup_printf("kill-external-dnsmasq-process-%" G_PID_FORMAT, pid),
+            TRUE),
+        .started_at   = nm_utils_get_monotonic_timestamp_msec(),
+        .pid          = pid,
+        .p_start_time = p_start_time,
+    };
+    g_timeout_add(50, _gl_pid_kill_external_timeout_cb, NULL);
+    return FALSE;
+}
+
+/*****************************************************************************/
+
+static gboolean
+_gl_pid_spawn_clear_pid(void)
+{
+    gboolean was_stopping = !!gl_pid.terminate_handle;
+
+    gl_pid.pid               = 0;
+    gl_pid.terminate_sigkill = FALSE;
+    nm_clear_g_source(&gl_pid.watch_id);
+    nm_clear_g_source(&gl_pid.terminate_timeout_id);
+    nm_clear_pointer(&gl_pid.terminate_handle, nm_shutdown_wait_obj_unregister);
+    return was_stopping;
+}
+
+static void
+_gl_pid_spawn_register_for_termination(void)
+{
+    if (gl_pid.pid > 0 && !gl_pid.terminate_handle) {
+        /* Create a shutdown handle as a reminder that the currently running process must be terminated
+         * first. This also happens to block shutdown... */
+        gl_pid.terminate_handle = nm_shutdown_wait_obj_register_handle_full(
+            g_strdup_printf("kill-dnsmasq-process-%" G_PID_FORMAT, gl_pid.pid),
+            TRUE);
+    }
+}
+
+/**
+ * _gl_pid_spawn_notify:
+ * @sdata: the notify data. @sdata might be destroyed by the function,
+ *   depending on the other arguments (which indicate whether the
+ *   task is complete).
+ * @pid: the PID to notify (argument for GlPidSpawnAsyncNotify)
+ * @p_exit_code: the exit code to notify (argument for GlPidSpawnAsyncNotify)
+ * @error: error reason to notify (argument for GlPidSpawnAsyncNotify)
+ *
+ * The GlPidSpawnAsyncNotify callback passed to _gl_pid_spawn() is used
+ * for two purposes:
+ *
+ *  - signal that the dnsmasq process was spawned (or failed to be spawned).
+ *  - signal that the dnsmasq process quit (if it was spawned successfully before).
+ *
+ * Depending on the arguments, the callee can see what's the case.
+ */
+static void
+_gl_pid_spawn_notify(GlPidSpawnAsyncData *sdata, GPid pid, const int *p_exit_code, GError *error)
+{
+    gboolean destroy = TRUE;
+
+    nm_assert(sdata);
+
+    if (error) {
+        nm_assert(pid == 0);
+        nm_assert(!p_exit_code);
+        if (!nm_utils_error_is_cancelled(error))
+            _LOGD("spawn: dnsmasq failed: %s", error->message);
+    } else if (p_exit_code) {
+        /* the only caller already logged about this condition extensively. */
+        nm_assert(pid > 0);
+    } else {
+        nm_assert(pid > 0);
+        _LOGD("spawn: dnsmasq started with pid %" G_PID_FORMAT, pid);
+        destroy = FALSE;
+    }
+
+    nm_assert((!!destroy) == (sdata != gl_pid.spawn_data));
+
+    if (destroy)
+        g_signal_handlers_disconnect_by_func(sdata->cancellable, _gl_pid_spawn_cancelled_cb, sdata);
+
+    sdata->notify(sdata->cancellable, pid, p_exit_code, error, sdata->notify_user_data);
+
+    if (destroy) {
+        g_clear_object(&sdata->cancellable);
+        nm_g_slice_free(sdata);
+    }
+}
+
+static void
+_gl_pid_spawn_cancelled_cb(GCancellable *cancellable, GlPidSpawnAsyncData *sdata)
+{
+    gs_free_error GError *error = NULL;
+
+    if (sdata == gl_pid.spawn_data) {
+        gl_pid.spawn_data = NULL;
+
+        /* When the cancellable gets cancelled, we terminate the current dnsmasq instance
+         * in the background. The only way for keeping dnsmasq running while unregistering
+         * the callback is by calling _gl_pid_spawn() without a new callback. */
+        _gl_pid_spawn_register_for_termination();
+    } else
+        nm_assert_not_reached();
+
+    if (!g_cancellable_set_error_if_cancelled(cancellable, &error))
+        nm_assert_not_reached();
+
+    _gl_pid_spawn_notify(sdata, 0, NULL, error);
+
+    _gl_pid_spawn_next_step();
+}
+
+static gboolean
+_gl_pid_spawn_terminate_timeout_cb(gpointer user_data)
+{
+    nm_assert(gl_pid.terminate_timeout_id != 0);
+    nm_assert(gl_pid.pid > 0);
+    nm_assert(gl_pid.terminate_handle);
+    nm_assert(gl_pid.watch_id != 0);
+
+    gl_pid.terminate_timeout_id = 0;
+
+    if (!gl_pid.terminate_sigkill) {
+        gl_pid.terminate_sigkill = TRUE;
+        _LOGD("spawn: send SIGKILL signal to dnsmasq process %" G_PID_FORMAT
+              " as it did not exit yet",
+              gl_pid.pid);
+        kill(gl_pid.pid, SIGKILL);
+        gl_pid.terminate_timeout_id =
+            g_timeout_add(WAIT_MSEC_AFTER_SIGKILL, _gl_pid_spawn_terminate_timeout_cb, NULL);
+    } else {
+        _LOGE("spawn: process %" G_PID_FORMAT " did not exit even after SIGTERM and SIGKILL",
+              gl_pid.pid);
+
+        /* we don't unregister the watch. Just forget about it. We still want to reap the child eventually. */
+        gl_pid.watch_id = 0;
+
+        _gl_pid_spawn_clear_pid();
+        _gl_pid_spawn_next_step();
+    }
+
+    return G_SOURCE_REMOVE;
+}
+
+static void
+_gl_pid_spawn_watch_cb(GPid pid, int status, gpointer user_data)
+{
+    int      err;
+    gboolean was_stopping;
+
+    nm_assert(pid > 0);
+
+    if (WIFEXITED(status)) {
+        err = WEXITSTATUS(status);
+        if (err) {
+            char sbuf[100];
+
+            _LOGW("spawn: dnsmasq process %" G_PID_FORMAT " exited with error: %s",
+                  pid,
+                  nm_utils_dnsmasq_status_to_string(err, sbuf, sizeof(sbuf)));
+        } else
+            _LOGD("spawn: dnsmasq process %" G_PID_FORMAT " exited normally", pid);
+    } else if (WIFSTOPPED(status))
+        _LOGW("spawn: dnsmasq process %" G_PID_FORMAT " stopped unexpectedly with signal %d",
+              pid,
+              WSTOPSIG(status));
+    else if (WIFSIGNALED(status))
+        _LOGW("spawn: dnsmasq process %" G_PID_FORMAT " died with signal %d",
+              pid,
+              WTERMSIG(status));
+    else
+        _LOGW("spawn: dnsmasq process %" G_PID_FORMAT " died from an unknown cause (status %d)",
+              pid,
+              status);
+
+    if (gl_pid.pid != pid) {
+        /* this can only happen, if we timed out and no longer care about this PID.
+         * We still kept the watch-id active, to reap the process. Nothing to do. */
+        return;
+    }
+
+    nm_assert(gl_pid.watch_id != 0);
+
+    gl_pid.watch_id = 0;
+
+    _gl_pid_unlink_pidfile(TRUE);
+
+    was_stopping = _gl_pid_spawn_clear_pid();
+
+    if (gl_pid.spawn_data) {
+        if (was_stopping) {
+            /* The current process was scheduled to be terminated. That means the pending
+             * spawn_data is not for that former instance, but for starting a new one.
+             * This spawn-request is not yet complete, instead it's just about to start. */
+        } else
+            _gl_pid_spawn_notify(g_steal_pointer(&gl_pid.spawn_data), pid, &status, NULL);
+    }
+
+    _gl_pid_spawn_next_step();
+}
+
+/**
+ * _gl_pid_spawn_next_step:
+ *
+ * The state about a running dnsmasq process is tracked in @gl_pid. There are
+ * various things that can happen
+ *
+ *   - user calls _gl_pid_spawn() -- which might terminate an existing run first.
+ *   - user might cancel the GCancellable -- which would abort the spawning or
+ *     kill the current instance.
+ *   - the child process might exit.
+ *
+ * In all these cases, we call _gl_pid_spawn_next_step() to check what to do next.
+ */
+static void
+_gl_pid_spawn_next_step(void)
+{
+    gs_free_error GError *error = NULL;
+    const char *          argv[15];
+    GPid                  pid = 0;
+    guint                 argv_idx;
+
+    if (!_gl_pid_kill_external()) {
+        /* we need to wait to kill the instance from the PID file first. */
+        return;
+    }
+
+    if (gl_pid.terminate_handle) {
+        nm_assert(gl_pid.pid > 0);
+
+        if (gl_pid.terminate_timeout_id == 0) {
+            _LOGD("spawn: send SIGTERM signal to process %" G_PID_FORMAT, gl_pid.pid);
+            gl_pid.terminate_timeout_id =
+                g_timeout_add(WAIT_MSEC_AFTER_SIGTERM, _gl_pid_spawn_terminate_timeout_cb, NULL);
+            kill(gl_pid.pid, SIGTERM);
+        }
+
+        /* we can only wait for the process to exit. */
+        return;
+    }
+
+    if (!gl_pid.spawn_data) {
+        /* we are not requested to spawn another process. */
+        nm_assert(gl_pid.pid == 0);
+        return;
+    }
+
+    if (gl_pid.pid > 0) {
+        /* the process we desire is already running. All good. */
+        return;
+    }
+
+    argv_idx         = 0;
+    argv[argv_idx++] = gl_pid.spawn_data->dm_binary;
+    argv[argv_idx++] = "--no-resolv"; /* Use only commandline */
+    argv[argv_idx++] = "--keep-in-foreground";
+    argv[argv_idx++] = "--no-hosts"; /* don't use /etc/hosts to resolve */
+    argv[argv_idx++] = "--bind-interfaces";
+    argv[argv_idx++] = "--pid-file=" PIDFILE;
+    argv[argv_idx++] = "--listen-address=127.0.0.1"; /* Should work for both 4 and 6 */
+    argv[argv_idx++] = "--cache-size=400";
+    argv[argv_idx++] = "--clear-on-reload";     /* clear cache when dns server changes */
+    argv[argv_idx++] = "--conf-file=/dev/null"; /* avoid loading /etc/dnsmasq.conf */
+    argv[argv_idx++] = "--proxy-dnssec";        /* Allow DNSSEC to pass through */
+    argv[argv_idx++] = "--enable-dbus=" DNSMASQ_DBUS_SERVICE;
+
+    /* dnsmasq exits if the conf dir is not present */
+    if (g_file_test(CONFDIR, G_FILE_TEST_IS_DIR))
+        argv[argv_idx++] = "--conf-dir=" CONFDIR;
+
+    argv[argv_idx++] = NULL;
+    nm_assert(argv_idx <= G_N_ELEMENTS(argv));
+
+    if (!_LOGD_ENABLED())
+        _LOGI("starting %s", gl_pid.spawn_data->dm_binary);
+    else {
+        gs_free char *cmdline = NULL;
+
+        _LOGD("spawn: starting dnsmasq: %s", (cmdline = g_strjoinv(" ", (char **) argv)));
+    }
+
+    if (!g_spawn_async(NULL,
+                       (char **) argv,
+                       NULL,
+                       G_SPAWN_DO_NOT_REAP_CHILD,
+                       nm_utils_setpgid,
+                       NULL,
+                       &pid,
+                       &error)) {
+        _gl_pid_spawn_notify(g_steal_pointer(&gl_pid.spawn_data), 0, NULL, error);
+        return;
+    }
+
+    gl_pid.pid      = pid;
+    gl_pid.watch_id = g_child_watch_add(pid, _gl_pid_spawn_watch_cb, NULL);
+
+    _gl_pid_spawn_notify(gl_pid.spawn_data, pid, NULL, NULL);
+}
+
+/**
+ * _gl_pid_spawn:
+ * @dm_binary: the binary name for dnsmasq to spawn. We could
+ *   detect it ad-hoc right when needing it. But that would be
+ *   asynchronously, and if dnsmasq is not in $PATH, we want to
+ *   fail right away (synchronously). Hence, @dm_binary is
+ *   an argument.
+ * @cancellable: abort the operation. This will invoke the callback
+ *   a last time. Also, if the dnsmasq process is currently running,
+ *   it will be terminated in the background. To unregister a notify
+ *   call without killing the dnsmasq process, call _gl_pid_spawn()
+ *   again with all arguments %NULL.
+ * @notify: the callback when the process is started successfully
+ *   and when the process terminates.
+ * @notify_user_data: user-data for callback.
+ *
+ * If a dnsmasq process is already running (from a previous call of
+ * _gl_pid_spawn()), that one will be replaced. Meaning, the other notify
+ * callback will be invoked with NM_UTILS_ERROR/NM_UTILS_ERROR_CANCELLED_DISPOSING.
+ * If you the @dm_binary argument, the previously running process will
+ * also be terminated first, before spawning a new instance.
+ * However, you may also pass all arguments as %NULL. In that case, the
+ * previous @notify will be completed (and forgotten), but the dnsmasq
+ * process will be left running in the background.
+ *
+ * So, you can:
+ *
+ *   - call _gl_pid_spawn() with a @dm_binary argument. The previous
+ *     notify() completes with NM_UTILS_ERROR_CANCELLED_DISPOSING and
+ *     the dnsmasq process gets killed.
+ *   - cancel the GCancellable, in this case the notify() completes
+ *     with G_IO_ERROR_CANCELLED and the dnsmasq process gets killed.
+ *   - call _gl_pid_spawn() with all arguments %NULL. In that case
+ *     the previous notify() completes with NM_UTILS_ERROR_CANCELLED_DISPOSING
+ *     but the dnsmasq process keeps running in the background.
+ *
+ * The callback is used in two cases.
+ * - When spawning the process it will be invoked always exactly once.
+ *   In this case the callback might be invoked synchronously or
+ *   asynchronously.
+ *   This either provides a PID or a failure reason. In case of a
+ *   failure, that's the end and the process is not running.
+ * - if the process could be spawned, the child process with the
+ *   provided PID gets monitored. When the process exits, the callback
+ *   will be invoked again, with a failure reason. This is always done
+ *   asynchronously.
+ */
+static void
+_gl_pid_spawn(const char *          dm_binary,
+              GCancellable *        cancellable,
+              GlPidSpawnAsyncNotify notify,
+              gpointer              notify_user_data)
+{
+    GlPidSpawnAsyncData *sdata_replace;
+
+    sdata_replace = g_steal_pointer(&gl_pid.spawn_data);
+
+    if (dm_binary) {
+        nm_assert(notify);
+        nm_assert(G_IS_CANCELLABLE(cancellable));
+        gl_pid.spawn_data  = g_slice_new(GlPidSpawnAsyncData);
+        *gl_pid.spawn_data = (GlPidSpawnAsyncData){
+            .dm_binary        = dm_binary,
+            .notify           = notify,
+            .notify_user_data = notify_user_data,
+            .cancellable      = g_object_ref(cancellable),
+        };
+        g_signal_connect(cancellable,
+                         "cancelled",
+                         G_CALLBACK(_gl_pid_spawn_cancelled_cb),
+                         gl_pid.spawn_data);
+
+        /* If dnsmasq is running, we terminate it and start a new instance.
+         *
+         * If the user would not provide a new callback, this would mean to fail/abort
+         * the currently subscribed notification (below). But it would leave the dnsmasq
+         * instance running in the background.
+         * This allows the user to say to not care about the current instance
+         * anymore, but still leave it running.
+         *
+         * To kill the dnsmasq process without scheduling a new one, cancel the cancellable
+         * instead. */
+        _gl_pid_spawn_register_for_termination();
+    } else {
+        nm_assert(!notify);
+        nm_assert(!cancellable);
+        nm_assert(!notify_user_data);
+    }
+
+    if (sdata_replace) {
+        gs_free_error GError *error = NULL;
+
+        /* we don't mark the error as G_IO_ERROR/G_IO_ERROR_CANCELLED. That
+         * is reserved for cancelling the cancellable. However, the current
+         * request was obsoleted/replaced by a new one, so we fail it with
+         * NM_UTILS_ERROR/NM_UTILS_ERROR_CANCELLED_DISPOSING. */
+        nm_utils_error_set_cancelled(&error, TRUE, NULL);
+        _gl_pid_spawn_notify(sdata_replace, 0, NULL, error);
+    }
+
+    _gl_pid_spawn_next_step();
+}
+
+/*****************************************************************************/
+
+typedef struct {
+    GDBusConnection *dbus_connection;
+
+    GVariant *set_server_ex_args;
+
+    GCancellable *update_cancellable;
+
+    GCancellable *main_cancellable;
+
+    char *name_owner;
+
+    gint64 burst_start_at;
+
+    GPid process_pid;
+
+    guint name_owner_changed_id;
+    guint main_timeout_id;
+
+    guint burst_retry_timeout_id;
+
+    guint8 burst_count;
+
+    bool is_stopped : 1;
+
+} NMDnsDnsmasqPrivate;
+
+struct _NMDnsDnsmasq {
+    NMDnsPlugin         parent;
+    NMDnsDnsmasqPrivate _priv;
+};
+
+struct _NMDnsDnsmasqClass {
+    NMDnsPluginClass parent;
+};
+
+G_DEFINE_TYPE(NMDnsDnsmasq, nm_dns_dnsmasq, NM_TYPE_DNS_PLUGIN)
+
+#define NM_DNS_DNSMASQ_GET_PRIVATE(self) _NM_GET_PRIVATE(self, NMDnsDnsmasq, NM_IS_DNS_DNSMASQ)
+
+/*****************************************************************************/
+
+#undef _NMLOG
+#define _NMLOG(level, ...) __NMLOG_DEFAULT_WITH_ADDR(level, _NMLOG_DOMAIN, "dnsmasq", __VA_ARGS__)
+
+/*****************************************************************************/
+
+static gboolean start_dnsmasq(NMDnsDnsmasq *self, gboolean force_start, GError **error);
+
+/*****************************************************************************/
+
+static void
+add_dnsmasq_nameserver(NMDnsDnsmasq *   self,
+                       GVariantBuilder *servers,
+                       const char *     ip,
+                       const char *     domain)
+{
+    g_return_if_fail(ip);
+
+    _LOGD("adding nameserver '%s'%s%s%s",
+          ip,
+          NM_PRINT_FMT_QUOTED(domain, " for domain \"", domain, "\"", ""));
+
+    g_variant_builder_open(servers, G_VARIANT_TYPE("as"));
+
+    g_variant_builder_add(servers, "s", ip);
+    if (domain)
+        g_variant_builder_add(servers, "s", domain);
+
+    g_variant_builder_close(servers);
+}
+
+#define IP_ADDR_TO_STRING_BUFLEN (NM_UTILS_INET_ADDRSTRLEN + 1 + IFNAMSIZ)
+
+static const char *
+ip_addr_to_string(int addr_family, gconstpointer addr, const char *iface, char *out_buf)
+{
+    int         n_written;
+    char        buf2[NM_UTILS_INET_ADDRSTRLEN];
+    const char *separator;
+
+    nm_assert_addr_family(addr_family);
+    nm_assert(addr);
+    nm_assert(out_buf);
+
+    if (addr_family == AF_INET) {
+        nm_utils_inet_ntop(addr_family, addr, buf2);
+        separator = "@";
+    } else {
+        if (IN6_IS_ADDR_V4MAPPED(addr))
+            _nm_utils_inet4_ntop(((const struct in6_addr *) addr)->s6_addr32[3], buf2);
+        else
+            _nm_utils_inet6_ntop(addr, buf2);
+        /* Need to scope link-local addresses with %<zone-id>. Before dnsmasq 2.58,
+         * only '@' was supported as delimiter. Since 2.58, '@' and '%' are
+         * supported. Due to a bug, since 2.73 only '%' works properly as "server"
+         * address.
+         */
+        separator = IN6_IS_ADDR_LINKLOCAL(addr) ? "%" : "@";
+    }
+
+    n_written = g_snprintf(out_buf,
+                           IP_ADDR_TO_STRING_BUFLEN,
+                           "%s%s%s",
+                           buf2,
+                           iface ? separator : "",
+                           iface ?: "");
+    nm_assert(n_written < IP_ADDR_TO_STRING_BUFLEN);
+    return out_buf;
+}
+
+static void
+add_global_config(NMDnsDnsmasq *           self,
+                  GVariantBuilder *        dnsmasq_servers,
+                  const NMGlobalDnsConfig *config)
+{
+    guint i, j;
+
+    g_return_if_fail(config);
+
+    for (i = 0; i < nm_global_dns_config_get_num_domains(config); i++) {
+        NMGlobalDnsDomain *domain  = nm_global_dns_config_get_domain(config, i);
+        const char *const *servers = nm_global_dns_domain_get_servers(domain);
+        const char *       name    = nm_global_dns_domain_get_name(domain);
+
+        g_return_if_fail(name);
+
+        for (j = 0; servers && servers[j]; j++) {
+            if (!strcmp(name, "*"))
+                add_dnsmasq_nameserver(self, dnsmasq_servers, servers[j], NULL);
+            else
+                add_dnsmasq_nameserver(self, dnsmasq_servers, servers[j], name);
+        }
+    }
+}
+
+static void
+add_ip_config(NMDnsDnsmasq *self, GVariantBuilder *servers, const NMDnsConfigIPData *ip_data)
+{
+    NMIPConfig *  ip_config = ip_data->ip_config;
+    gconstpointer addr;
+    const char *  iface, *domain;
+    char          ip_addr_to_string_buf[IP_ADDR_TO_STRING_BUFLEN];
+    int           addr_family;
+    guint         i, j, num;
+
+    iface       = nm_platform_link_get_name(NM_PLATFORM_GET, ip_data->data->ifindex);
+    addr_family = nm_ip_config_get_addr_family(ip_config);
+
+    num = nm_ip_config_get_num_nameservers(ip_config);
+    for (i = 0; i < num; i++) {
+        addr = nm_ip_config_get_nameserver(ip_config, i);
+        ip_addr_to_string(addr_family, addr, iface, ip_addr_to_string_buf);
+
+        if (!ip_data->domains.has_default_route_explicit && ip_data->domains.has_default_route)
+            add_dnsmasq_nameserver(self, servers, ip_addr_to_string_buf, NULL);
+        if (ip_data->domains.search) {
+            for (j = 0; ip_data->domains.search[j]; j++) {
+                domain = nm_utils_parse_dns_domain(ip_data->domains.search[j], NULL);
+                add_dnsmasq_nameserver(self,
+                                       servers,
+                                       ip_addr_to_string_buf,
+                                       domain[0] ? domain : NULL);
+            }
+        }
+        if (ip_data->domains.reverse) {
+            for (j = 0; ip_data->domains.reverse[j]; j++) {
+                add_dnsmasq_nameserver(self,
+                                       servers,
+                                       ip_addr_to_string_buf,
+                                       ip_data->domains.reverse[j]);
+            }
+        }
+    }
+}
+
+static GVariant *
+create_update_args(NMDnsDnsmasq *           self,
+                   const NMGlobalDnsConfig *global_config,
+                   const CList *            ip_config_lst_head,
+                   const char *             hostname)
+{
+    GVariantBuilder          servers;
+    const NMDnsConfigIPData *ip_data;
+
+    g_variant_builder_init(&servers, G_VARIANT_TYPE("aas"));
+
+    if (global_config)
+        add_global_config(self, &servers, global_config);
+    else {
+        c_list_for_each_entry (ip_data, ip_config_lst_head, ip_config_lst)
+            add_ip_config(self, &servers, ip_data);
+    }
+
+    return g_variant_new("(aas)", &servers);
+}
+
+/*****************************************************************************/
+
+static void
+dnsmasq_update_done(GObject *source_object, GAsyncResult *res, gpointer user_data)
+{
+    NMDnsDnsmasq *self;
+    gs_free_error GError *error         = NULL;
+    gs_unref_variant GVariant *response = NULL;
+
+    response = g_dbus_connection_call_finish(G_DBUS_CONNECTION(source_object), res, &error);
+
+    if (nm_utils_error_is_cancelled(error))
+        return;
+
+    self = user_data;
+    if (!response)
+        _LOGW("dnsmasq update failed: %s", error->message);
+    else
+        _LOGD("dnsmasq update successful");
+}
+
+static void
+send_dnsmasq_update(NMDnsDnsmasq *self)
+{
+    NMDnsDnsmasqPrivate *priv = NM_DNS_DNSMASQ_GET_PRIVATE(self);
+
+    if (!priv->name_owner || !priv->set_server_ex_args)
+        return;
+
+    _LOGD("trying to update dnsmasq nameservers");
+
+    nm_clear_g_cancellable(&priv->update_cancellable);
+    priv->update_cancellable = g_cancellable_new();
+
+    g_dbus_connection_call(priv->dbus_connection,
+                           priv->name_owner,
+                           DNSMASQ_DBUS_PATH,
+                           DNSMASQ_DBUS_SERVICE,
+                           "SetServersEx",
+                           priv->set_server_ex_args,
+                           NULL,
+                           G_DBUS_CALL_FLAGS_NO_AUTO_START,
+                           20000,
+                           priv->update_cancellable,
+                           dnsmasq_update_done,
+                           self);
+}
+
+/*****************************************************************************/
+
+static void
+_main_cleanup(NMDnsDnsmasq *self, gboolean emit_failed)
+{
+    NMDnsDnsmasqPrivate *priv = NM_DNS_DNSMASQ_GET_PRIVATE(self);
+
+    if (!priv->main_cancellable)
+        return;
+
+    priv->process_pid = 0;
+    nm_clear_g_free(&priv->name_owner);
+
+    nm_clear_g_dbus_connection_signal(priv->dbus_connection, &priv->name_owner_changed_id);
+
+    nm_clear_g_source(&priv->main_timeout_id);
+    nm_clear_g_cancellable(&priv->update_cancellable);
+
+    /* cancelling the main_cancellable will also cause _gl_pid_spawn*() to terminate the
+     * process in the background. */
+    nm_clear_g_cancellable(&priv->main_cancellable);
+
+    if (!priv->is_stopped && priv->burst_retry_timeout_id == 0) {
+        start_dnsmasq(self, FALSE, NULL);
+        send_dnsmasq_update(self);
+    }
+}
+
+static void
+name_owner_changed(NMDnsDnsmasq *self, const char *name_owner)
+{
+    NMDnsDnsmasqPrivate *priv = NM_DNS_DNSMASQ_GET_PRIVATE(self);
+
+    name_owner = nm_str_not_empty(name_owner);
+
+    if (nm_streq0(priv->name_owner, name_owner))
+        return;
+
+    g_free(priv->name_owner);
+    priv->name_owner = g_strdup(name_owner);
+
+    if (!name_owner) {
+        _LOGT("D-Bus name for dnsmasq disappeared");
+        _main_cleanup(self, TRUE);
+        return;
+    }
+
+    _LOGT("D-Bus name for dnsmasq got owner %s", name_owner);
+    nm_clear_g_source(&priv->main_timeout_id);
+    send_dnsmasq_update(self);
+}
+
+static void
+name_owner_changed_cb(GDBusConnection *connection,
+                      const char *     sender_name,
+                      const char *     object_path,
+                      const char *     interface_name,
+                      const char *     signal_name,
+                      GVariant *       parameters,
+                      gpointer         user_data)
+{
+    NMDnsDnsmasq *self = user_data;
+    const char *  new_owner;
+
+    if (!g_variant_is_of_type(parameters, G_VARIANT_TYPE("(sss)")))
+        return;
+
+    g_variant_get(parameters, "(&s&s&s)", NULL, NULL, &new_owner);
+
+    name_owner_changed(self, new_owner);
+}
+
+static void
+get_name_owner_cb(const char *name_owner, GError *error, gpointer user_data)
+{
+    if (!name_owner && g_error_matches(error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+        return;
+
+    name_owner_changed(user_data, name_owner);
+}
+
+static gboolean
+spawn_timeout_cb(gpointer user_data)
+{
+    NMDnsDnsmasq *self = user_data;
+
+    _LOGW("timeout waiting for dnsmasq to appear on D-Bus");
+    _main_cleanup(self, TRUE);
+    return G_SOURCE_REMOVE;
+}
+
+static void
+spawn_notify(GCancellable *cancellable,
+             GPid          pid,
+             const int *   p_exit_code,
+             GError *      error,
+             gpointer      notify_user_data)
+{
+    NMDnsDnsmasq *       self;
+    NMDnsDnsmasqPrivate *priv;
+
+    if (nm_utils_error_is_cancelled(error))
+        return;
+
+    self = notify_user_data;
+    priv = NM_DNS_DNSMASQ_GET_PRIVATE(self);
+    if (error || p_exit_code) {
+        _main_cleanup(self, TRUE);
+        return;
+    }
+
+    nm_assert(pid > 0);
+    priv->process_pid = pid;
+
+    priv->name_owner_changed_id =
+        nm_dbus_connection_signal_subscribe_name_owner_changed(priv->dbus_connection,
+                                                               DNSMASQ_DBUS_SERVICE,
+                                                               name_owner_changed_cb,
+                                                               self,
+                                                               NULL);
+    nm_dbus_connection_call_get_name_owner(priv->dbus_connection,
+                                           DNSMASQ_DBUS_SERVICE,
+                                           -1,
+                                           priv->main_cancellable,
+                                           get_name_owner_cb,
+                                           self);
+}
+
+static gboolean
+_burst_retry_timeout_cb(gpointer user_data)
+{
+    NMDnsDnsmasq *       self = user_data;
+    NMDnsDnsmasqPrivate *priv = NM_DNS_DNSMASQ_GET_PRIVATE(self);
+
+    priv->burst_retry_timeout_id = 0;
+
+    start_dnsmasq(self, TRUE, NULL);
+    send_dnsmasq_update(self);
+    return G_SOURCE_REMOVE;
+}
+
+static gboolean
+start_dnsmasq(NMDnsDnsmasq *self, gboolean force_start, GError **error)
+{
+    NMDnsDnsmasqPrivate *priv = NM_DNS_DNSMASQ_GET_PRIVATE(self);
+    const char *         dm_binary;
+    gint64               now;
+
+    if (G_LIKELY(priv->main_cancellable)) {
+        /* The process is already running or about to be started. Nothing to do. */
+        return TRUE;
+    }
+
+    dm_binary = nm_utils_find_helper("dnsmasq", DNSMASQ_PATH, NULL);
+    if (!dm_binary) {
+        /* We resolve the binary name before trying to start it asynchronously.
+         * The reason is, that if dnsmasq is not installed, we want to fail early,
+         * so that NMDnsManager can fallback to a non-caching implementation. */
+        nm_utils_error_set(error, NM_UTILS_ERROR_UNKNOWN, "could not find dnsmasq binary");
+        return FALSE;
+    }
+
+    if (!priv->dbus_connection) {
+        priv->dbus_connection = nm_g_object_ref(NM_MAIN_DBUS_CONNECTION_GET);
+        if (!priv->dbus_connection) {
+            nm_utils_error_set(error,
+                               NM_UTILS_ERROR_UNKNOWN,
+                               "no D-Bus connection available to talk to dnsmasq");
+            return FALSE;
+        }
+    }
+
+    now = nm_utils_get_monotonic_timestamp_msec();
+    if (force_start || priv->burst_start_at == 0
+        || priv->burst_start_at + RATELIMIT_INTERVAL_MSEC <= now) {
+        priv->burst_start_at = now;
+        priv->burst_count    = 1;
+        nm_clear_g_source(&priv->burst_retry_timeout_id);
+        _LOGT("rate-limit: start burst interval of %d seconds %s",
+              RATELIMIT_INTERVAL_MSEC / 1000,
+              force_start ? " (force)" : "");
+    } else if (priv->burst_count < RATELIMIT_BURST) {
+        nm_assert(priv->burst_retry_timeout_id == 0);
+        priv->burst_count++;
+        _LOGT("rate-limit: %u try within burst interval of %d seconds",
+              (guint) priv->burst_count,
+              RATELIMIT_INTERVAL_MSEC / 1000);
+    } else {
+        if (priv->burst_retry_timeout_id == 0) {
+            _LOGW("dnsmasq dies and gets respawned too quickly. Back off. Something is very wrong");
+            priv->burst_retry_timeout_id =
+                g_timeout_add_seconds((2 * RATELIMIT_INTERVAL_MSEC) / 1000,
+                                      _burst_retry_timeout_cb,
+                                      self);
+        } else
+            _LOGT("rate-limit: currently rate-limited from restart");
+        return TRUE;
+    }
+
+    priv->main_timeout_id = g_timeout_add(10000, spawn_timeout_cb, self);
+
+    priv->main_cancellable = g_cancellable_new();
+
+    _gl_pid_spawn(dm_binary, priv->main_cancellable, spawn_notify, self);
+    return TRUE;
+}
+
+static gboolean
+update(NMDnsPlugin *            plugin,
+       const NMGlobalDnsConfig *global_config,
+       const CList *            ip_config_lst_head,
+       const char *             hostname,
+       GError **                error)
+{
+    NMDnsDnsmasq *       self = NM_DNS_DNSMASQ(plugin);
+    NMDnsDnsmasqPrivate *priv = NM_DNS_DNSMASQ_GET_PRIVATE(self);
+
+    if (!start_dnsmasq(self, TRUE, error))
+        return FALSE;
+
+    nm_clear_pointer(&priv->set_server_ex_args, g_variant_unref);
+    priv->set_server_ex_args =
+        g_variant_ref_sink(create_update_args(self, global_config, ip_config_lst_head, hostname));
+
+    send_dnsmasq_update(self);
+    return TRUE;
+}
+
+/*****************************************************************************/
+
+static void
+stop(NMDnsPlugin *plugin)
+{
+    NMDnsDnsmasq *       self = NM_DNS_DNSMASQ(plugin);
+    NMDnsDnsmasqPrivate *priv = NM_DNS_DNSMASQ_GET_PRIVATE(self);
+
+    priv->is_stopped     = TRUE;
+    priv->burst_start_at = 0;
+    nm_clear_g_source(&priv->burst_retry_timeout_id);
+
+    /* Cancelling the cancellable will also terminate the
+     * process (in the background). */
+    _main_cleanup(self, FALSE);
+}
+
+/*****************************************************************************/
+
+static void
+nm_dns_dnsmasq_init(NMDnsDnsmasq *self)
+{}
+
+NMDnsPlugin *
+nm_dns_dnsmasq_new(void)
+{
+    return g_object_new(NM_TYPE_DNS_DNSMASQ, NULL);
+}
+
+static void
+dispose(GObject *object)
+{
+    NMDnsDnsmasq *       self = NM_DNS_DNSMASQ(object);
+    NMDnsDnsmasqPrivate *priv = NM_DNS_DNSMASQ_GET_PRIVATE(self);
+
+    priv->is_stopped = TRUE;
+
+    nm_clear_g_source(&priv->burst_retry_timeout_id);
+
+    _main_cleanup(self, FALSE);
+
+    nm_clear_pointer(&priv->set_server_ex_args, g_variant_unref);
+
+    G_OBJECT_CLASS(nm_dns_dnsmasq_parent_class)->dispose(object);
+
+    g_clear_object(&priv->dbus_connection);
+}
+
+static void
+nm_dns_dnsmasq_class_init(NMDnsDnsmasqClass *dns_class)
+{
+    NMDnsPluginClass *plugin_class = NM_DNS_PLUGIN_CLASS(dns_class);
+    GObjectClass *    object_class = G_OBJECT_CLASS(dns_class);
+
+    object_class->dispose = dispose;
+
+    plugin_class->plugin_name = "dnsmasq";
+    plugin_class->is_caching  = TRUE;
+    plugin_class->stop        = stop;
+    plugin_class->update      = update;
+}
diff --git a/src/core/dns/nm-dns-dnsmasq.h b/src/core/dns/nm-dns-dnsmasq.h
new file mode 100644
index 00000000..bd6d4c60
--- /dev/null
+++ b/src/core/dns/nm-dns-dnsmasq.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2010 Red Hat, Inc.
+ */
+
+#ifndef __NETWORKMANAGER_DNS_DNSMASQ_H__
+#define __NETWORKMANAGER_DNS_DNSMASQ_H__
+
+#include "nm-dns-plugin.h"
+
+#define NM_TYPE_DNS_DNSMASQ (nm_dns_dnsmasq_get_type())
+#define NM_DNS_DNSMASQ(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), NM_TYPE_DNS_DNSMASQ, NMDnsDnsmasq))
+#define NM_DNS_DNSMASQ_CLASS(klass) \
+    (G_TYPE_CHECK_CLASS_CAST((klass), NM_TYPE_DNS_DNSMASQ, NMDnsDnsmasqClass))
+#define NM_IS_DNS_DNSMASQ(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj), NM_TYPE_DNS_DNSMASQ))
+#define NM_IS_DNS_DNSMASQ_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), NM_TYPE_DNS_DNSMASQ))
+#define NM_DNS_DNSMASQ_GET_CLASS(obj) \
+    (G_TYPE_INSTANCE_GET_CLASS((obj), NM_TYPE_DNS_DNSMASQ, NMDnsDnsmasqClass))
+
+typedef struct _NMDnsDnsmasq      NMDnsDnsmasq;
+typedef struct _NMDnsDnsmasqClass NMDnsDnsmasqClass;
+
+GType nm_dns_dnsmasq_get_type(void);
+
+NMDnsPlugin *nm_dns_dnsmasq_new(void);
+
+#endif /* __NETWORKMANAGER_DNS_DNSMASQ_H__ */
diff --git a/src/core/dns/nm-dns-manager.c b/src/core/dns/nm-dns-manager.c
new file mode 100644
index 00000000..f318b9b8
--- /dev/null
+++ b/src/core/dns/nm-dns-manager.c
@@ -0,0 +1,2676 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2004 - 2005 Colin Walters <walters@redhat.com>
+ * Copyright (C) 2004 - 2017 Red Hat, Inc.
+ * Copyright (C) 2005 - 2008 Novell, Inc.
+ */
+
+#include "src/core/nm-default-daemon.h"
+
+#include <fcntl.h>
+#include <resolv.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include <linux/fs.h>
+
+#if WITH_LIBPSL
+    #include <libpsl.h>
+#endif
+
+#include "nm-utils.h"
+#include "nm-core-internal.h"
+#include "nm-dns-manager.h"
+#include "nm-ip4-config.h"
+#include "nm-ip6-config.h"
+#include "NetworkManagerUtils.h"
+#include "nm-config.h"
+#include "nm-dbus-object.h"
+#include "devices/nm-device.h"
+#include "nm-manager.h"
+
+#include "nm-dns-plugin.h"
+#include "nm-dns-dnsmasq.h"
+#include "nm-dns-systemd-resolved.h"
+#include "nm-dns-unbound.h"
+
+#define HASH_LEN NM_UTILS_CHECKSUM_LENGTH_SHA1
+
+#ifndef RESOLVCONF_PATH
+    #define RESOLVCONF_PATH "/sbin/resolvconf"
+    #define HAS_RESOLVCONF  0
+#else
+    #define HAS_RESOLVCONF 1
+#endif
+
+#ifndef NETCONFIG_PATH
+    #define NETCONFIG_PATH "/sbin/netconfig"
+    #define HAS_NETCONFIG  0
+#else
+    #define HAS_NETCONFIG 1
+#endif
+
+/*****************************************************************************/
+
+typedef enum { SR_SUCCESS, SR_NOTFOUND, SR_ERROR } SpawnResult;
+
+typedef struct {
+    GPtrArray * nameservers;
+    GPtrArray * searches;
+    GPtrArray * options;
+    const char *nis_domain;
+    GPtrArray * nis_servers;
+    NMTernary   has_trust_ad;
+} NMResolvConfData;
+
+/*****************************************************************************/
+
+enum {
+    CONFIG_CHANGED,
+
+    LAST_SIGNAL
+};
+
+NM_GOBJECT_PROPERTIES_DEFINE(NMDnsManager, PROP_MODE, PROP_RC_MANAGER, PROP_CONFIGURATION, );
+
+static guint signals[LAST_SIGNAL] = {0};
+
+typedef struct {
+    GHashTable *configs_dict;
+    CList       configs_lst_head;
+
+    CList     ip_configs_lst_head;
+    GVariant *config_variant;
+
+    NMDnsConfigIPData *best_ip_config_4;
+    NMDnsConfigIPData *best_ip_config_6;
+
+    bool ip_configs_lst_need_sort : 1;
+
+    bool configs_lst_need_sort : 1;
+
+    bool dns_touched : 1;
+    bool is_stopped : 1;
+
+    char *hostname;
+    guint updates_queue;
+
+    guint8 hash[HASH_LEN];      /* SHA1 hash of current DNS config */
+    guint8 prev_hash[HASH_LEN]; /* Hash when begin_updates() was called */
+
+    NMDnsManagerResolvConfManager rc_manager;
+    char *                        mode;
+    NMDnsPlugin *                 sd_resolve_plugin;
+    NMDnsPlugin *                 plugin;
+
+    NMConfig *config;
+
+    struct {
+        guint64 ts;
+        guint   num_restarts;
+        guint   timer;
+    } plugin_ratelimit;
+} NMDnsManagerPrivate;
+
+struct _NMDnsManager {
+    NMDBusObject        parent;
+    NMDnsManagerPrivate _priv;
+};
+
+struct _NMDnsManagerClass {
+    NMDBusObjectClass parent;
+};
+
+G_DEFINE_TYPE(NMDnsManager, nm_dns_manager, NM_TYPE_DBUS_OBJECT)
+
+#define NM_DNS_MANAGER_GET_PRIVATE(self) _NM_GET_PRIVATE(self, NMDnsManager, NM_IS_DNS_MANAGER)
+
+NM_DEFINE_SINGLETON_GETTER(NMDnsManager, nm_dns_manager_get, NM_TYPE_DNS_MANAGER);
+
+/*****************************************************************************/
+
+#define _NMLOG_PREFIX_NAME "dns-mgr"
+#define _NMLOG_DOMAIN      LOGD_DNS
+#define _NMLOG(level, ...)                                           \
+    G_STMT_START                                                     \
+    {                                                                \
+        const NMLogLevel __level = (level);                          \
+                                                                     \
+        if (nm_logging_enabled(__level, _NMLOG_DOMAIN)) {            \
+            char                      __prefix[20];                  \
+            const NMDnsManager *const __self = (self);               \
+                                                                     \
+            _nm_log(__level,                                         \
+                    _NMLOG_DOMAIN,                                   \
+                    0,                                               \
+                    NULL,                                            \
+                    NULL,                                            \
+                    "%s%s: " _NM_UTILS_MACRO_FIRST(__VA_ARGS__),     \
+                    _NMLOG_PREFIX_NAME,                              \
+                    ((!__self || __self == singleton_instance)       \
+                         ? ""                                        \
+                         : nm_sprintf_buf(__prefix, "[%p]", __self)) \
+                        _NM_UTILS_MACRO_REST(__VA_ARGS__));          \
+        }                                                            \
+    }                                                                \
+    G_STMT_END
+
+/*****************************************************************************/
+
+static void
+_ip_config_dns_priority_changed(gpointer config, GParamSpec *pspec, NMDnsConfigIPData *ip_data);
+
+/*****************************************************************************/
+
+static gboolean
+domain_is_valid(const char *domain, gboolean check_public_suffix)
+{
+    if (*domain == '\0')
+        return FALSE;
+#if WITH_LIBPSL
+    if (check_public_suffix && psl_is_public_suffix(psl_builtin(), domain))
+        return FALSE;
+#endif
+    return TRUE;
+}
+
+static gboolean
+domain_is_routing(const char *domain)
+{
+    return domain[0] == '~';
+}
+
+/*****************************************************************************/
+
+static NM_UTILS_LOOKUP_STR_DEFINE(
+    _rc_manager_to_string,
+    NMDnsManagerResolvConfManager,
+    NM_UTILS_LOOKUP_DEFAULT_WARN(NULL),
+    NM_UTILS_LOOKUP_STR_ITEM(NM_DNS_MANAGER_RESOLV_CONF_MAN_AUTO, "auto"),
+    NM_UTILS_LOOKUP_STR_ITEM(NM_DNS_MANAGER_RESOLV_CONF_MAN_UNKNOWN, "unknown"),
+    NM_UTILS_LOOKUP_STR_ITEM(NM_DNS_MANAGER_RESOLV_CONF_MAN_UNMANAGED, "unmanaged"),
+    NM_UTILS_LOOKUP_STR_ITEM(NM_DNS_MANAGER_RESOLV_CONF_MAN_IMMUTABLE, "immutable"),
+    NM_UTILS_LOOKUP_STR_ITEM(NM_DNS_MANAGER_RESOLV_CONF_MAN_SYMLINK, "symlink"),
+    NM_UTILS_LOOKUP_STR_ITEM(NM_DNS_MANAGER_RESOLV_CONF_MAN_FILE, "file"),
+    NM_UTILS_LOOKUP_STR_ITEM(NM_DNS_MANAGER_RESOLV_CONF_MAN_RESOLVCONF, "resolvconf"),
+    NM_UTILS_LOOKUP_STR_ITEM(NM_DNS_MANAGER_RESOLV_CONF_MAN_NETCONFIG, "netconfig"), );
+
+static NM_UTILS_LOOKUP_STR_DEFINE(
+    _config_type_to_string,
+    NMDnsIPConfigType,
+    NM_UTILS_LOOKUP_DEFAULT_WARN("<unknown>"),
+    NM_UTILS_LOOKUP_STR_ITEM(NM_DNS_IP_CONFIG_TYPE_REMOVED, "removed"),
+    NM_UTILS_LOOKUP_STR_ITEM(NM_DNS_IP_CONFIG_TYPE_DEFAULT, "default"),
+    NM_UTILS_LOOKUP_STR_ITEM(NM_DNS_IP_CONFIG_TYPE_BEST_DEVICE, "best"),
+    NM_UTILS_LOOKUP_STR_ITEM(NM_DNS_IP_CONFIG_TYPE_VPN, "vpn"), );
+
+/*****************************************************************************/
+
+static void
+_ASSERT_dns_config_data(const NMDnsConfigData *data)
+{
+    nm_assert(data);
+    nm_assert(NM_IS_DNS_MANAGER(data->self));
+    nm_assert(data->ifindex > 0);
+}
+
+static void
+_ASSERT_dns_config_ip_data(const NMDnsConfigIPData *ip_data)
+{
+    nm_assert(ip_data);
+    _ASSERT_dns_config_data(ip_data->data);
+    nm_assert(NM_IS_IP_CONFIG(ip_data->ip_config));
+    nm_assert(c_list_contains(&ip_data->data->data_lst_head, &ip_data->data_lst));
+    nm_assert(ip_data->data->ifindex == nm_ip_config_get_ifindex(ip_data->ip_config));
+#if NM_MORE_ASSERTS > 5
+    {
+        gboolean has_default = FALSE;
+        gsize    i;
+
+        for (i = 0; ip_data->domains.search && ip_data->domains.search; i++) {
+            const char *d = ip_data->domains.search[i];
+
+            d = nm_utils_parse_dns_domain(d, NULL);
+            nm_assert(d);
+            if (d[0] == '\0')
+                has_default = TRUE;
+        }
+        nm_assert(has_default == ip_data->domains.has_default_route_explicit);
+        if (ip_data->domains.has_default_route_explicit)
+            nm_assert(ip_data->domains.has_default_route_exclusive);
+        if (ip_data->domains.has_default_route_exclusive)
+            nm_assert(ip_data->domains.has_default_route);
+    }
+#endif
+}
+
+static NMDnsConfigIPData *
+_dns_config_ip_data_new(NMDnsConfigData * data,
+                        NMIPConfig *      ip_config,
+                        NMDnsIPConfigType ip_config_type)
+{
+    NMDnsConfigIPData *ip_data;
+
+    _ASSERT_dns_config_data(data);
+    nm_assert(NM_IS_IP_CONFIG(ip_config));
+    nm_assert(ip_config_type != NM_DNS_IP_CONFIG_TYPE_REMOVED);
+
+    ip_data  = g_slice_new(NMDnsConfigIPData);
+    *ip_data = (NMDnsConfigIPData){
+        .data           = data,
+        .ip_config      = g_object_ref(ip_config),
+        .ip_config_type = ip_config_type,
+    };
+    c_list_link_tail(&data->data_lst_head, &ip_data->data_lst);
+    c_list_link_tail(&NM_DNS_MANAGER_GET_PRIVATE(data->self)->ip_configs_lst_head,
+                     &ip_data->ip_config_lst);
+
+    g_signal_connect(ip_config,
+                     NM_IS_IP4_CONFIG(ip_config) ? "notify::" NM_IP4_CONFIG_DNS_PRIORITY
+                                                 : "notify::" NM_IP6_CONFIG_DNS_PRIORITY,
+                     (GCallback) _ip_config_dns_priority_changed,
+                     ip_data);
+
+    _ASSERT_dns_config_ip_data(ip_data);
+    return ip_data;
+}
+
+static void
+_dns_config_ip_data_free(NMDnsConfigIPData *ip_data)
+{
+    _ASSERT_dns_config_ip_data(ip_data);
+
+    c_list_unlink_stale(&ip_data->data_lst);
+    c_list_unlink_stale(&ip_data->ip_config_lst);
+
+    g_free(ip_data->domains.search);
+    g_strfreev(ip_data->domains.reverse);
+
+    g_signal_handlers_disconnect_by_func(ip_data->ip_config,
+                                         _ip_config_dns_priority_changed,
+                                         ip_data);
+
+    g_object_unref(ip_data->ip_config);
+    nm_g_slice_free(ip_data);
+}
+
+static NMDnsConfigIPData *
+_dns_config_data_find_ip_config(NMDnsConfigData *data, NMIPConfig *ip_config)
+{
+    NMDnsConfigIPData *ip_data;
+
+    _ASSERT_dns_config_data(data);
+
+    c_list_for_each_entry (ip_data, &data->data_lst_head, data_lst) {
+        _ASSERT_dns_config_ip_data(ip_data);
+
+        if (ip_data->ip_config == ip_config)
+            return ip_data;
+    }
+    return NULL;
+}
+
+static void
+_dns_config_data_free(NMDnsConfigData *data)
+{
+    _ASSERT_dns_config_data(data);
+
+    nm_assert(c_list_is_empty(&data->data_lst_head));
+    c_list_unlink_stale(&data->configs_lst);
+    nm_g_slice_free(data);
+}
+
+static int
+_mgr_get_ip_configs_lst_cmp(const CList *a_lst, const CList *b_lst, const void *user_data)
+{
+    const NMDnsConfigIPData *a = c_list_entry(a_lst, NMDnsConfigIPData, ip_config_lst);
+    const NMDnsConfigIPData *b = c_list_entry(b_lst, NMDnsConfigIPData, ip_config_lst);
+
+    /* Configurations with lower priority value first */
+    NM_CMP_DIRECT(nm_ip_config_get_dns_priority(a->ip_config),
+                  nm_ip_config_get_dns_priority(b->ip_config));
+
+    /* Sort according to type (descendingly) */
+    NM_CMP_FIELD(b, a, ip_config_type);
+
+    return 0;
+}
+
+static CList *
+_mgr_get_ip_configs_lst_head(NMDnsManager *self)
+{
+    NMDnsManagerPrivate *priv = NM_DNS_MANAGER_GET_PRIVATE(self);
+
+    if (G_UNLIKELY(priv->ip_configs_lst_need_sort)) {
+        priv->ip_configs_lst_need_sort = FALSE;
+        c_list_sort(&priv->ip_configs_lst_head, _mgr_get_ip_configs_lst_cmp, NULL);
+    }
+
+    return &priv->ip_configs_lst_head;
+}
+
+static int
+_mgr_get_configs_lst_cmp(const CList *a_lst, const CList *b_lst, const void *user_data)
+{
+    const NMDnsConfigData *a = c_list_entry(a_lst, NMDnsConfigData, configs_lst);
+    const NMDnsConfigData *b = c_list_entry(b_lst, NMDnsConfigData, configs_lst);
+
+    NM_CMP_FIELD(b, a, ifindex);
+    return nm_assert_unreachable_val(0);
+}
+
+_nm_unused static CList *
+_mgr_get_configs_lst_head(NMDnsManager *self)
+{
+    NMDnsManagerPrivate *priv = NM_DNS_MANAGER_GET_PRIVATE(self);
+
+    if (G_UNLIKELY(priv->configs_lst_need_sort)) {
+        priv->configs_lst_need_sort = FALSE;
+        c_list_sort(&priv->configs_lst_head, _mgr_get_configs_lst_cmp, NULL);
+    }
+
+    return &priv->configs_lst_head;
+}
+
+/*****************************************************************************/
+
+gboolean
+nm_dns_manager_has_systemd_resolved(NMDnsManager *self)
+{
+    NMDnsManagerPrivate * priv;
+    NMDnsSystemdResolved *plugin = NULL;
+
+    g_return_val_if_fail(NM_IS_DNS_MANAGER(self), FALSE);
+
+    priv = NM_DNS_MANAGER_GET_PRIVATE(self);
+
+    if (priv->sd_resolve_plugin) {
+        nm_assert(!NM_IS_DNS_SYSTEMD_RESOLVED(priv->plugin));
+        plugin = NM_DNS_SYSTEMD_RESOLVED(priv->sd_resolve_plugin);
+    } else if (NM_IS_DNS_SYSTEMD_RESOLVED(priv->plugin))
+        plugin = NM_DNS_SYSTEMD_RESOLVED(priv->plugin);
+
+    return plugin && nm_dns_systemd_resolved_is_running(plugin);
+}
+
+/*****************************************************************************/
+
+static void
+add_string_item(GPtrArray *array, const char *str, gboolean dup)
+{
+    int i;
+
+    g_return_if_fail(array != NULL);
+    g_return_if_fail(str != NULL);
+
+    /* Check for dupes before adding */
+    for (i = 0; i < array->len; i++) {
+        const char *candidate = g_ptr_array_index(array, i);
+
+        if (candidate && !strcmp(candidate, str))
+            return;
+    }
+
+    /* No dupes, add the new item */
+    g_ptr_array_add(array, dup ? g_strdup(str) : (gpointer) str);
+}
+
+static void
+add_dns_option_item(GPtrArray *array, const char *str)
+{
+    if (_nm_utils_dns_option_find_idx(array, str) < 0)
+        g_ptr_array_add(array, g_strdup(str));
+}
+
+static void
+add_dns_domains(GPtrArray *       array,
+                const NMIPConfig *ip_config,
+                gboolean          include_routing,
+                gboolean          dup)
+{
+    guint       num_domains, num_searches, i;
+    const char *str;
+
+    num_domains  = nm_ip_config_get_num_domains(ip_config);
+    num_searches = nm_ip_config_get_num_searches(ip_config);
+
+    for (i = 0; i < num_searches; i++) {
+        str = nm_ip_config_get_search(ip_config, i);
+        if (!include_routing && domain_is_routing(str))
+            continue;
+        if (!domain_is_valid(nm_utils_parse_dns_domain(str, NULL), FALSE))
+            continue;
+        add_string_item(array, str, dup);
+    }
+    if (num_domains > 1 || !num_searches) {
+        for (i = 0; i < num_domains; i++) {
+            str = nm_ip_config_get_domain(ip_config, i);
+            if (!include_routing && domain_is_routing(str))
+                continue;
+            if (!domain_is_valid(nm_utils_parse_dns_domain(str, NULL), FALSE))
+                continue;
+            add_string_item(array, str, dup);
+        }
+    }
+}
+
+static void
+merge_one_ip_config(NMResolvConfData *rc, int ifindex, const NMIPConfig *ip_config)
+{
+    int      addr_family;
+    char     buf[NM_UTILS_INET_ADDRSTRLEN + 50];
+    gboolean has_trust_ad;
+    guint    num_nameservers;
+    guint    num;
+    guint    i;
+
+    addr_family = nm_ip_config_get_addr_family(ip_config);
+
+    nm_assert_addr_family(addr_family);
+    nm_assert(ifindex > 0);
+    nm_assert(ifindex == nm_ip_config_get_ifindex(ip_config));
+
+    num_nameservers = nm_ip_config_get_num_nameservers(ip_config);
+    for (i = 0; i < num_nameservers; i++) {
+        const NMIPAddr *addr;
+
+        addr = nm_ip_config_get_nameserver(ip_config, i);
+        if (addr_family == AF_INET)
+            nm_utils_inet_ntop(addr_family, addr, buf);
+        else if (IN6_IS_ADDR_V4MAPPED(addr))
+            _nm_utils_inet4_ntop(addr->addr6.s6_addr32[3], buf);
+        else {
+            _nm_utils_inet6_ntop(&addr->addr6, buf);
+            if (IN6_IS_ADDR_LINKLOCAL(addr)) {
+                const char *ifname;
+
+                ifname = nm_platform_link_get_name(NM_PLATFORM_GET, ifindex);
+                if (ifname) {
+                    g_strlcat(buf, "%", sizeof(buf));
+                    g_strlcat(buf, ifname, sizeof(buf));
+                }
+            }
+        }
+
+        add_string_item(rc->nameservers, buf, TRUE);
+    }
+
+    add_dns_domains(rc->searches, ip_config, FALSE, TRUE);
+
+    has_trust_ad = FALSE;
+    num          = nm_ip_config_get_num_dns_options(ip_config);
+    for (i = 0; i < num; i++) {
+        const char *option = nm_ip_config_get_dns_option(ip_config, i);
+
+        if (nm_streq(option, NM_SETTING_DNS_OPTION_TRUST_AD)) {
+            has_trust_ad = TRUE;
+            continue;
+        }
+        add_dns_option_item(rc->options, nm_ip_config_get_dns_option(ip_config, i));
+    }
+    if (num_nameservers == 0) {
+        /* If the @ip_config contributes no DNS servers, ignore whether trust-ad is set or unset
+         * for this @ip_config. */
+    } else if (has_trust_ad) {
+        /* We only set has_trust_ad to TRUE, if all IP configs agree (or don't contribute).
+         * Once set to FALSE, it doesn't get reset. */
+        if (rc->has_trust_ad == NM_TERNARY_DEFAULT)
+            rc->has_trust_ad = NM_TERNARY_TRUE;
+    } else
+        rc->has_trust_ad = NM_TERNARY_FALSE;
+
+    if (addr_family == AF_INET) {
+        const NMIP4Config *ip4_config = (const NMIP4Config *) ip_config;
+
+        /* NIS stuff */
+        num = nm_ip4_config_get_num_nis_servers(ip4_config);
+        for (i = 0; i < num; i++) {
+            add_string_item(rc->nis_servers,
+                            _nm_utils_inet4_ntop(nm_ip4_config_get_nis_server(ip4_config, i), buf),
+                            TRUE);
+        }
+
+        if (nm_ip4_config_get_nis_domain(ip4_config)) {
+            /* FIXME: handle multiple domains */
+            if (!rc->nis_domain)
+                rc->nis_domain = nm_ip4_config_get_nis_domain(ip4_config);
+        }
+    }
+}
+
+static GPid
+run_netconfig(NMDnsManager *self, GError **error, int *stdin_fd)
+{
+    char *        argv[5];
+    gs_free char *tmp = NULL;
+    GPid          pid = -1;
+
+    argv[0] = NETCONFIG_PATH;
+    argv[1] = "modify";
+    argv[2] = "--service";
+    argv[3] = "NetworkManager";
+    argv[4] = NULL;
+
+    _LOGD("spawning '%s'", (tmp = g_strjoinv(" ", argv)));
+
+    if (!g_spawn_async_with_pipes(NULL,
+                                  argv,
+                                  NULL,
+                                  G_SPAWN_DO_NOT_REAP_CHILD,
+                                  NULL,
+                                  NULL,
+                                  &pid,
+                                  stdin_fd,
+                                  NULL,
+                                  NULL,
+                                  error))
+        return -1;
+
+    return pid;
+}
+
+static void
+netconfig_construct_str(NMDnsManager *self, GString *str, const char *key, const char *value)
+{
+    if (value) {
+        _LOGD("writing to netconfig: %s='%s'", key, value);
+        g_string_append_printf(str, "%s='%s'\n", key, value);
+    }
+}
+
+static void
+netconfig_construct_strv(NMDnsManager *     self,
+                         GString *          str,
+                         const char *       key,
+                         const char *const *values)
+{
+    if (values) {
+        gs_free char *value = NULL;
+
+        value = g_strjoinv(" ", (char **) values);
+        netconfig_construct_str(self, str, key, value);
+    }
+}
+
+static SpawnResult
+dispatch_netconfig(NMDnsManager *     self,
+                   const char *const *searches,
+                   const char *const *nameservers,
+                   const char *       nis_domain,
+                   const char *const *nis_servers,
+                   GError **          error)
+{
+    GPid                 pid;
+    int                  fd;
+    int                  errsv;
+    int                  status;
+    gssize               l;
+    nm_auto_free_gstring GString *str = NULL;
+
+    pid = run_netconfig(self, error, &fd);
+    if (pid <= 0)
+        return SR_NOTFOUND;
+
+    str = g_string_new("");
+
+    /* NM is writing already-merged DNS information to netconfig, so it
+     * does not apply to a specific network interface.
+     */
+    netconfig_construct_str(self, str, "INTERFACE", "NetworkManager");
+    netconfig_construct_strv(self, str, "DNSSEARCH", searches);
+    netconfig_construct_strv(self, str, "DNSSERVERS", nameservers);
+    netconfig_construct_str(self, str, "NISDOMAIN", nis_domain);
+    netconfig_construct_strv(self, str, "NISSERVERS", nis_servers);
+
+again:
+    l = write(fd, str->str, str->len);
+    if (l == -1) {
+        if (errno == EINTR)
+            goto again;
+    }
+
+    nm_close(fd);
+
+    /* FIXME: don't write to netconfig synchronously. */
+
+    /* Wait until the process exits */
+    if (!nm_utils_kill_child_sync(pid, 0, LOGD_DNS, "netconfig", &status, 1000, 0)) {
+        errsv = errno;
+        g_set_error(error,
+                    NM_MANAGER_ERROR,
+                    NM_MANAGER_ERROR_FAILED,
+                    "Error waiting for netconfig to exit: %s",
+                    nm_strerror_native(errsv));
+        return SR_ERROR;
+    }
+    if (!WIFEXITED(status) || WEXITSTATUS(status) != EXIT_SUCCESS) {
+        g_set_error(error,
+                    NM_MANAGER_ERROR,
+                    NM_MANAGER_ERROR_FAILED,
+                    "Error calling netconfig: %s %d",
+                    WIFEXITED(status) ? "exited with status"
+                                      : (WIFSIGNALED(status) ? "exited with signal"
+                                                             : "exited with unknown reason"),
+                    WIFEXITED(status) ? WEXITSTATUS(status)
+                                      : (WIFSIGNALED(status) ? WTERMSIG(status) : status));
+        return SR_ERROR;
+    }
+    return SR_SUCCESS;
+}
+
+static char *
+create_resolv_conf(const char *const *searches,
+                   const char *const *nameservers,
+                   const char *const *options)
+{
+    GString *str;
+    gsize    i;
+
+    str = g_string_new_len(NULL, 245);
+
+    g_string_append(str, "# Generated by NetworkManager\n");
+
+    if (searches && searches[0]) {
+        gsize search_base_idx;
+
+        g_string_append(str, "search");
+        search_base_idx = str->len;
+
+        for (i = 0; searches[i]; i++) {
+            const char *s = searches[i];
+            gsize       l = strlen(s);
+
+            if (l == 0 || NM_STRCHAR_ANY(s, ch, NM_IN_SET(ch, ' ', '\t', '\n'))) {
+                /* there should be no such characters in the search entry. Also,
+                 * because glibc parser would treat them as line/word separator.
+                 *
+                 * Skip the value silently. */
+                continue;
+            }
+
+            if (search_base_idx > 0) {
+                if (str->len - search_base_idx + 1 + l > 254) {
+                    /* this entry crosses the 256 character boundary. Older glibc versions
+                     * would truncate the entry at this point.
+                     *
+                     * Fill the line with spaces to cross the 256 char boundary and continue
+                     * afterwards. This way, the truncation happens between two search entries. */
+                    while (str->len - search_base_idx < 257)
+                        g_string_append_c(str, ' ');
+                    search_base_idx = 0;
+                }
+            }
+
+            g_string_append_c(str, ' ');
+            g_string_append_len(str, s, l);
+        }
+        g_string_append_c(str, '\n');
+    }
+
+    if (nameservers && nameservers[0]) {
+        for (i = 0; nameservers[i]; i++) {
+            if (i == 3) {
+                g_string_append(
+                    str,
+                    "# NOTE: the libc resolver may not support more than 3 nameservers.\n");
+                g_string_append(str, "# The nameservers listed below may not be recognized.\n");
+            }
+            g_string_append(str, "nameserver ");
+            g_string_append(str, nameservers[i]);
+            g_string_append_c(str, '\n');
+        }
+    }
+
+    if (options && options[0]) {
+        g_string_append(str, "options");
+        for (i = 0; options[i]; i++) {
+            g_string_append_c(str, ' ');
+            g_string_append(str, options[i]);
+        }
+        g_string_append_c(str, '\n');
+    }
+
+    return g_string_free(str, FALSE);
+}
+
+char *
+nmtst_dns_create_resolv_conf(const char *const *searches,
+                             const char *const *nameservers,
+                             const char *const *options)
+{
+    return create_resolv_conf(searches, nameservers, options);
+}
+
+static gboolean
+write_resolv_conf_contents(FILE *f, const char *content, GError **error)
+{
+    int errsv;
+
+    if (fprintf(f, "%s", content) < 0) {
+        errsv = errno;
+        g_set_error(error,
+                    NM_MANAGER_ERROR,
+                    NM_MANAGER_ERROR_FAILED,
+                    "Could not write " _PATH_RESCONF ": %s",
+                    nm_strerror_native(errsv));
+        errno = errsv;
+        return FALSE;
+    }
+
+    return TRUE;
+}
+
+static gboolean
+write_resolv_conf(FILE *             f,
+                  const char *const *searches,
+                  const char *const *nameservers,
+                  const char *const *options,
+                  GError **          error)
+{
+    gs_free char *content = NULL;
+
+    content = create_resolv_conf(searches, nameservers, options);
+    return write_resolv_conf_contents(f, content, error);
+}
+
+static SpawnResult
+dispatch_resolvconf(NMDnsManager *self,
+                    char **       searches,
+                    char **       nameservers,
+                    char **       options,
+                    GError **     error)
+{
+    gs_free char *cmd = NULL;
+    FILE *        f;
+    gboolean      success = FALSE;
+    int           errsv;
+    int           err;
+    char *        argv[] = {RESOLVCONF_PATH, "-d", "NetworkManager", NULL};
+    int           status;
+
+    if (!g_file_test(RESOLVCONF_PATH, G_FILE_TEST_IS_EXECUTABLE)) {
+        g_set_error_literal(error,
+                            NM_MANAGER_ERROR,
+                            NM_MANAGER_ERROR_FAILED,
+                            RESOLVCONF_PATH " is not executable");
+        return SR_NOTFOUND;
+    }
+
+    if (!searches && !nameservers) {
+        _LOGI("Removing DNS information from %s", RESOLVCONF_PATH);
+
+        if (!g_spawn_sync("/", argv, NULL, 0, NULL, NULL, NULL, NULL, &status, error))
+            return SR_ERROR;
+
+        if (status != 0) {
+            g_set_error(error,
+                        NM_MANAGER_ERROR,
+                        NM_MANAGER_ERROR_FAILED,
+                        "%s returned error code",
+                        RESOLVCONF_PATH);
+            return SR_ERROR;
+        }
+
+        return SR_SUCCESS;
+    }
+
+    _LOGI("Writing DNS information to %s", RESOLVCONF_PATH);
+
+    /* FIXME: don't write to resolvconf synchronously. */
+
+    cmd = g_strconcat(RESOLVCONF_PATH, " -a ", "NetworkManager", NULL);
+    if ((f = popen(cmd, "w")) == NULL) {
+        errsv = errno;
+        g_set_error(error,
+                    NM_MANAGER_ERROR,
+                    NM_MANAGER_ERROR_FAILED,
+                    "Could not write to %s: %s",
+                    RESOLVCONF_PATH,
+                    nm_strerror_native(errsv));
+        return SR_ERROR;
+    }
+
+    success = write_resolv_conf(f,
+                                NM_CAST_STRV_CC(searches),
+                                NM_CAST_STRV_CC(nameservers),
+                                NM_CAST_STRV_CC(options),
+                                error);
+    err     = pclose(f);
+    if (err < 0) {
+        errsv = errno;
+        g_clear_error(error);
+        g_set_error(error,
+                    G_IO_ERROR,
+                    g_io_error_from_errno(errsv),
+                    "Failed to close pipe to resolvconf: %d",
+                    errsv);
+        return SR_ERROR;
+    } else if (err > 0) {
+        _LOGW("resolvconf failed with status %d", err);
+        g_clear_error(error);
+        g_set_error(error, G_IO_ERROR, G_IO_ERROR_FAILED, "resolvconf failed with status %d", err);
+        return SR_ERROR;
+    }
+
+    return success ? SR_SUCCESS : SR_ERROR;
+}
+
+static const char *
+_read_link_cached(const char *path, gboolean *is_cached, char **cached)
+{
+    nm_assert(is_cached);
+    nm_assert(cached);
+
+    if (*is_cached)
+        return *cached;
+
+    nm_assert(!*cached);
+    *is_cached = TRUE;
+    return (*cached = g_file_read_link(path, NULL));
+}
+
+#define MY_RESOLV_CONF     NMRUNDIR "/resolv.conf"
+#define MY_RESOLV_CONF_TMP MY_RESOLV_CONF ".tmp"
+#define RESOLV_CONF_TMP    "/etc/.resolv.conf.NetworkManager"
+
+#define NO_STUB_RESOLV_CONF NMRUNDIR "/no-stub-resolv.conf"
+
+static void
+update_resolv_conf_no_stub(NMDnsManager *     self,
+                           const char *const *searches,
+                           const char *const *nameservers,
+                           const char *const *options)
+{
+    gs_free char *content = NULL;
+    GError *      local   = NULL;
+
+    content = create_resolv_conf(searches, nameservers, options);
+
+    if (!g_file_set_contents(NO_STUB_RESOLV_CONF, content, -1, &local)) {
+        _LOGD("update-resolv-no-stub: failure to write file: %s", local->message);
+        g_error_free(local);
+        return;
+    }
+
+    _LOGT("update-resolv-no-stub: '%s' successfully written", NO_STUB_RESOLV_CONF);
+}
+
+static SpawnResult
+update_resolv_conf(NMDnsManager *                self,
+                   const char *const *           searches,
+                   const char *const *           nameservers,
+                   const char *const *           options,
+                   GError **                     error,
+                   NMDnsManagerResolvConfManager rc_manager)
+{
+    FILE *        f;
+    gboolean      success;
+    gs_free char *content           = NULL;
+    SpawnResult   write_file_result = SR_SUCCESS;
+    int           errsv;
+    gboolean      resconf_link_cached = FALSE;
+    gs_free char *resconf_link        = NULL;
+
+    content = create_resolv_conf(searches, nameservers, options);
+
+    if (rc_manager == NM_DNS_MANAGER_RESOLV_CONF_MAN_FILE
+        || (rc_manager == NM_DNS_MANAGER_RESOLV_CONF_MAN_SYMLINK
+            && !_read_link_cached(_PATH_RESCONF, &resconf_link_cached, &resconf_link))) {
+        gs_free char *     rc_path_syml = NULL;
+        nm_auto_free char *rc_path_real = NULL;
+        const char *       rc_path      = _PATH_RESCONF;
+        GError *           local        = NULL;
+
+        if (rc_manager == NM_DNS_MANAGER_RESOLV_CONF_MAN_FILE) {
+            rc_path_real = realpath(_PATH_RESCONF, NULL);
+            if (rc_path_real)
+                rc_path = rc_path_real;
+            else {
+                /* realpath did not resolve a path-name. That either means,
+                 * _PATH_RESCONF:
+                 *   - does not exist
+                 *   - is a plain file
+                 *   - is a dangling symlink
+                 *
+                 * Handle the case, where it is a dangling symlink... */
+                rc_path_syml = nm_utils_read_link_absolute(_PATH_RESCONF, NULL);
+                if (rc_path_syml)
+                    rc_path = rc_path_syml;
+            }
+        }
+
+        /* we first write to /etc/resolv.conf directly. If that fails,
+         * we still continue to write to runstatedir but remember the
+         * error. */
+        if (!g_file_set_contents(rc_path, content, -1, &local)) {
+            _LOGT("update-resolv-conf: write to %s failed (rc-manager=%s, %s)",
+                  rc_path,
+                  _rc_manager_to_string(rc_manager),
+                  local->message);
+            g_propagate_error(error, local);
+            /* clear @error, so that we don't try reset it. This is the error
+             * we want to propagate to the caller. */
+            error             = NULL;
+            write_file_result = SR_ERROR;
+        } else {
+            _LOGT("update-resolv-conf: write to %s succeeded (rc-manager=%s)",
+                  rc_path,
+                  _rc_manager_to_string(rc_manager));
+        }
+    }
+
+    if ((f = fopen(MY_RESOLV_CONF_TMP, "we")) == NULL) {
+        errsv = errno;
+        g_set_error(error,
+                    NM_MANAGER_ERROR,
+                    NM_MANAGER_ERROR_FAILED,
+                    "Could not open %s: %s",
+                    MY_RESOLV_CONF_TMP,
+                    nm_strerror_native(errsv));
+        _LOGT("update-resolv-conf: open temporary file %s failed (%s)",
+              MY_RESOLV_CONF_TMP,
+              nm_strerror_native(errsv));
+        return SR_ERROR;
+    }
+
+    success = write_resolv_conf_contents(f, content, error);
+    if (!success) {
+        errsv = errno;
+        _LOGT("update-resolv-conf: write temporary file %s failed (%s)",
+              MY_RESOLV_CONF_TMP,
+              nm_strerror_native(errsv));
+    }
+
+    if (fclose(f) < 0) {
+        if (success) {
+            errsv = errno;
+            /* only set an error here if write_resolv_conf() was successful,
+             * since its error is more important.
+             */
+            g_set_error(error,
+                        NM_MANAGER_ERROR,
+                        NM_MANAGER_ERROR_FAILED,
+                        "Could not close %s: %s",
+                        MY_RESOLV_CONF_TMP,
+                        nm_strerror_native(errsv));
+            _LOGT("update-resolv-conf: close temporary file %s failed (%s)",
+                  MY_RESOLV_CONF_TMP,
+                  nm_strerror_native(errsv));
+        }
+        return SR_ERROR;
+    } else if (!success)
+        return SR_ERROR;
+
+    if (rename(MY_RESOLV_CONF_TMP, MY_RESOLV_CONF) < 0) {
+        errsv = errno;
+        g_set_error(error,
+                    NM_MANAGER_ERROR,
+                    NM_MANAGER_ERROR_FAILED,
+                    "Could not replace %s: %s",
+                    MY_RESOLV_CONF,
+                    nm_strerror_native(errsv));
+        _LOGT("update-resolv-conf: failed to rename temporary file %s to %s (%s)",
+              MY_RESOLV_CONF_TMP,
+              MY_RESOLV_CONF,
+              nm_strerror_native(errsv));
+        return SR_ERROR;
+    }
+
+    if (rc_manager == NM_DNS_MANAGER_RESOLV_CONF_MAN_FILE) {
+        _LOGT("update-resolv-conf: write internal file %s succeeded (rc-manager=%s)",
+              MY_RESOLV_CONF,
+              _rc_manager_to_string(rc_manager));
+        return write_file_result;
+    }
+
+    if (rc_manager != NM_DNS_MANAGER_RESOLV_CONF_MAN_SYMLINK
+        || !_read_link_cached(_PATH_RESCONF, &resconf_link_cached, &resconf_link)) {
+        _LOGT("update-resolv-conf: write internal file %s succeeded", MY_RESOLV_CONF);
+        return write_file_result;
+    }
+
+    if (!nm_streq0(_read_link_cached(_PATH_RESCONF, &resconf_link_cached, &resconf_link),
+                   MY_RESOLV_CONF)) {
+        _LOGT("update-resolv-conf: write internal file %s succeeded (don't touch symlink %s "
+              "linking to %s)",
+              MY_RESOLV_CONF,
+              _PATH_RESCONF,
+              _read_link_cached(_PATH_RESCONF, &resconf_link_cached, &resconf_link));
+        return write_file_result;
+    }
+
+    /* By this point, /etc/resolv.conf exists and is a symlink to our internal
+     * resolv.conf. We update the symlink so that applications get an inotify
+     * notification.
+     */
+    if (unlink(RESOLV_CONF_TMP) != 0 && ((errsv = errno) != ENOENT)) {
+        g_set_error(error,
+                    NM_MANAGER_ERROR,
+                    NM_MANAGER_ERROR_FAILED,
+                    "Could not unlink %s: %s",
+                    RESOLV_CONF_TMP,
+                    nm_strerror_native(errsv));
+        _LOGT("update-resolv-conf: write internal file %s succeeded "
+              "but cannot delete temporary file %s: %s",
+              MY_RESOLV_CONF,
+              RESOLV_CONF_TMP,
+              nm_strerror_native(errsv));
+        return SR_ERROR;
+    }
+
+    if (symlink(MY_RESOLV_CONF, RESOLV_CONF_TMP) == -1) {
+        errsv = errno;
+        g_set_error(error,
+                    NM_MANAGER_ERROR,
+                    NM_MANAGER_ERROR_FAILED,
+                    "Could not create symlink %s pointing to %s: %s",
+                    RESOLV_CONF_TMP,
+                    MY_RESOLV_CONF,
+                    nm_strerror_native(errsv));
+        _LOGT("update-resolv-conf: write internal file %s succeeded "
+              "but failed to symlink %s: %s",
+              MY_RESOLV_CONF,
+              RESOLV_CONF_TMP,
+              nm_strerror_native(errsv));
+        return SR_ERROR;
+    }
+
+    if (rename(RESOLV_CONF_TMP, _PATH_RESCONF) == -1) {
+        errsv = errno;
+        g_set_error(error,
+                    NM_MANAGER_ERROR,
+                    NM_MANAGER_ERROR_FAILED,
+                    "Could not rename %s to %s: %s",
+                    RESOLV_CONF_TMP,
+                    _PATH_RESCONF,
+                    nm_strerror_native(errsv));
+        _LOGT("update-resolv-conf: write internal file %s succeeded "
+              "but failed to rename temporary symlink %s to %s: %s",
+              MY_RESOLV_CONF,
+              RESOLV_CONF_TMP,
+              _PATH_RESCONF,
+              nm_strerror_native(errsv));
+        return SR_ERROR;
+    }
+
+    _LOGT("update-resolv-conf: write internal file %s succeeded and update symlink %s",
+          MY_RESOLV_CONF,
+          _PATH_RESCONF);
+    return write_file_result;
+}
+
+static void
+compute_hash(NMDnsManager *self, const NMGlobalDnsConfig *global, guint8 buffer[HASH_LEN])
+{
+    nm_auto_free_checksum GChecksum *sum = NULL;
+    NMDnsConfigIPData *              ip_data;
+
+    sum = g_checksum_new(G_CHECKSUM_SHA1);
+    nm_assert(HASH_LEN == g_checksum_type_get_length(G_CHECKSUM_SHA1));
+
+    if (global)
+        nm_global_dns_config_update_checksum(global, sum);
+    else {
+        const CList *head;
+
+        /* FIXME(ip-config-checksum): this relies on the fact that an IP
+         * configuration without DNS parameters gives a zero checksum. */
+        head = _mgr_get_ip_configs_lst_head(self);
+        c_list_for_each_entry (ip_data, head, ip_config_lst)
+            nm_ip_config_hash(ip_data->ip_config, sum, TRUE);
+    }
+
+    nm_utils_checksum_get_digest_len(sum, buffer, HASH_LEN);
+}
+
+static gboolean
+merge_global_dns_config(NMResolvConfData *rc, NMGlobalDnsConfig *global_conf)
+{
+    NMGlobalDnsDomain *default_domain;
+    const char *const *searches;
+    const char *const *options;
+    const char *const *servers;
+    guint              i;
+
+    if (!global_conf)
+        return FALSE;
+
+    searches = nm_global_dns_config_get_searches(global_conf);
+    if (searches) {
+        for (i = 0; searches[i]; i++) {
+            if (domain_is_routing(searches[i]))
+                continue;
+            if (!domain_is_valid(searches[i], FALSE))
+                continue;
+            add_string_item(rc->searches, searches[i], TRUE);
+        }
+    }
+
+    options = nm_global_dns_config_get_options(global_conf);
+    if (options) {
+        for (i = 0; options[i]; i++)
+            add_string_item(rc->options, options[i], TRUE);
+    }
+
+    default_domain = nm_global_dns_config_lookup_domain(global_conf, "*");
+    nm_assert(default_domain);
+
+    servers = nm_global_dns_domain_get_servers(default_domain);
+    if (servers) {
+        for (i = 0; servers[i]; i++)
+            add_string_item(rc->nameservers, servers[i], TRUE);
+    }
+
+    return TRUE;
+}
+
+static const char *
+get_nameserver_list(const NMIPConfig *config, GString **str)
+{
+    guint num, i;
+    char  buf[NM_UTILS_INET_ADDRSTRLEN];
+    int   addr_family;
+
+    if (*str)
+        g_string_truncate(*str, 0);
+    else
+        *str = g_string_sized_new(64);
+
+    addr_family = nm_ip_config_get_addr_family(config);
+    num         = nm_ip_config_get_num_nameservers(config);
+    for (i = 0; i < num; i++) {
+        nm_utils_inet_ntop(addr_family, nm_ip_config_get_nameserver(config, i), buf);
+        if (i > 0)
+            g_string_append_c(*str, ' ');
+        g_string_append(*str, buf);
+    }
+
+    return (*str)->str;
+}
+
+static char **
+_ptrarray_to_strv(GPtrArray *parray)
+{
+    if (parray->len > 0)
+        g_ptr_array_add(parray, NULL);
+    return (char **) g_ptr_array_free(parray, parray->len == 0);
+}
+
+static void
+_collect_resolv_conf_data(NMDnsManager *     self,
+                          NMGlobalDnsConfig *global_config,
+                          char ***           out_searches,
+                          char ***           out_options,
+                          char ***           out_nameservers,
+                          char ***           out_nis_servers,
+                          const char **      out_nis_domain)
+{
+    NMDnsManagerPrivate *priv;
+    NMResolvConfData     rc = {
+        .nameservers  = g_ptr_array_new(),
+        .searches     = g_ptr_array_new(),
+        .options      = g_ptr_array_new(),
+        .nis_domain   = NULL,
+        .nis_servers  = g_ptr_array_new(),
+        .has_trust_ad = NM_TERNARY_DEFAULT,
+    };
+
+    priv = NM_DNS_MANAGER_GET_PRIVATE(self);
+
+    if (global_config)
+        merge_global_dns_config(&rc, global_config);
+    else {
+        nm_auto_free_gstring GString *tmp_gstring = NULL;
+        int                           prio, first_prio = 0;
+        const NMDnsConfigIPData *     ip_data;
+        const CList *                 head;
+        gboolean                      is_first = TRUE;
+
+        head = _mgr_get_ip_configs_lst_head(self);
+        c_list_for_each_entry (ip_data, head, ip_config_lst) {
+            gboolean skip = FALSE;
+
+            _ASSERT_dns_config_ip_data(ip_data);
+
+            prio = nm_ip_config_get_dns_priority(ip_data->ip_config);
+
+            if (is_first) {
+                is_first   = FALSE;
+                first_prio = prio;
+            } else if (first_prio < 0 && first_prio != prio)
+                skip = TRUE;
+
+            if (nm_ip_config_get_num_nameservers(ip_data->ip_config)) {
+                _LOGT(
+                    "config: %8d %-7s v%c %-5d %s: %s",
+                    prio,
+                    _config_type_to_string(ip_data->ip_config_type),
+                    nm_utils_addr_family_to_char(nm_ip_config_get_addr_family(ip_data->ip_config)),
+                    ip_data->data->ifindex,
+                    skip ? "<SKIP>" : "",
+                    get_nameserver_list(ip_data->ip_config, &tmp_gstring));
+            }
+
+            if (!skip)
+                merge_one_ip_config(&rc, ip_data->data->ifindex, ip_data->ip_config);
+        }
+    }
+
+    /* If the hostname is a FQDN ("dcbw.example.com"), then add the domain part of it
+     * ("example.com") to the searches list, to ensure that we can still resolve its
+     * non-FQ form ("dcbw") too. (Also, if there are no other search domains specified,
+     * this makes a good default.) However, if the hostname is the top level of a domain
+     * (eg, "example.com"), then use the hostname itself as the search (since the user is
+     * unlikely to want "com" as a search domain).
+     */
+    if (priv->hostname) {
+        const char *hostdomain = strchr(priv->hostname, '.');
+
+        if (hostdomain && !nm_utils_ipaddr_is_valid(AF_UNSPEC, priv->hostname)) {
+            hostdomain++;
+            if (domain_is_valid(hostdomain, TRUE))
+                add_string_item(rc.searches, hostdomain, TRUE);
+            else if (domain_is_valid(priv->hostname, TRUE))
+                add_string_item(rc.searches, priv->hostname, TRUE);
+        }
+    }
+
+    if (rc.has_trust_ad == NM_TERNARY_TRUE)
+        g_ptr_array_add(rc.options, g_strdup(NM_SETTING_DNS_OPTION_TRUST_AD));
+
+    *out_searches    = _ptrarray_to_strv(rc.searches);
+    *out_options     = _ptrarray_to_strv(rc.options);
+    *out_nameservers = _ptrarray_to_strv(rc.nameservers);
+    *out_nis_servers = _ptrarray_to_strv(rc.nis_servers);
+    *out_nis_domain  = rc.nis_domain;
+}
+
+/*****************************************************************************/
+
+static char **
+get_ip_rdns_domains(NMIPConfig *ip_config)
+{
+    int                        addr_family = nm_ip_config_get_addr_family(ip_config);
+    char **                    strv;
+    GPtrArray *                domains;
+    NMDedupMultiIter           ipconf_iter;
+    const NMPlatformIPAddress *address;
+    const NMPlatformIPRoute *  route;
+
+    nm_assert_addr_family(addr_family);
+
+    domains = g_ptr_array_sized_new(5);
+
+    nm_ip_config_iter_ip_address_for_each (&ipconf_iter, ip_config, &address) {
+        nm_utils_get_reverse_dns_domains_ip(addr_family,
+                                            address->address_ptr,
+                                            address->plen,
+                                            domains);
+    }
+
+    nm_ip_config_iter_ip_route_for_each (&ipconf_iter, ip_config, &route) {
+        if (!NM_PLATFORM_IP_ROUTE_IS_DEFAULT(route)) {
+            nm_utils_get_reverse_dns_domains_ip(addr_family,
+                                                route->network_ptr,
+                                                route->plen,
+                                                domains);
+        }
+    }
+
+    /* Terminating NULL so we can use g_strfreev() to free it */
+    g_ptr_array_add(domains, NULL);
+
+    /* Free the array and return NULL if the only element was the ending NULL */
+    strv = (char **) g_ptr_array_free(domains, (domains->len == 1));
+
+    return _nm_utils_strv_cleanup(strv, FALSE, FALSE, TRUE);
+}
+
+static gboolean
+_domain_track_get_priority(GHashTable *ht, const char *domain, int *out_priority)
+{
+    gpointer ptr;
+
+    if (!ht || !g_hash_table_lookup_extended(ht, domain, NULL, &ptr)) {
+        *out_priority = 0;
+        return FALSE;
+    }
+    *out_priority = GPOINTER_TO_INT(ptr);
+    return TRUE;
+}
+
+/* Check if the domain is shadowed by a parent domain with more negative priority */
+static gboolean
+_domain_track_is_shadowed(GHashTable * ht,
+                          const char * domain,
+                          int          priority,
+                          const char **out_parent,
+                          int *        out_parent_priority)
+{
+    char *parent;
+    int   parent_priority;
+
+    if (!ht)
+        return FALSE;
+
+    nm_assert(!g_hash_table_contains(ht, domain));
+
+    if (_domain_track_get_priority(ht, "", &parent_priority)) {
+        nm_assert(parent_priority <= priority);
+        if (parent_priority < 0 && parent_priority < priority) {
+            *out_parent          = "";
+            *out_parent_priority = parent_priority;
+            return TRUE;
+        }
+    }
+
+    parent = strchr(domain, '.');
+    while (parent && parent[1]) {
+        parent++;
+        if (_domain_track_get_priority(ht, parent, &parent_priority)) {
+            nm_assert(parent_priority <= priority);
+            if (parent_priority < 0 && parent_priority < priority) {
+                *out_parent          = parent;
+                *out_parent_priority = parent_priority;
+                return TRUE;
+            }
+        }
+        parent = strchr(parent, '.');
+    }
+
+    return FALSE;
+}
+
+static void
+_mgr_configs_data_construct(NMDnsManager *self)
+{
+    NMDnsConfigIPData *ip_data;
+    gs_unref_hashtable GHashTable *ht               = NULL;
+    gs_unref_hashtable GHashTable *wildcard_entries = NULL;
+    CList *                        head;
+    int                            prev_priority = G_MININT;
+
+    head = _mgr_get_ip_configs_lst_head(self);
+
+#if NM_MORE_ASSERTS
+    /* we call _mgr_configs_data_clear() at the end of update. We
+     * don't expect any domain settings here. */
+    c_list_for_each_entry (ip_data, head, ip_config_lst) {
+        nm_assert(!ip_data->domains.search);
+        nm_assert(!ip_data->domains.reverse);
+        nm_assert(!ip_data->domains.has_default_route_explicit);
+        nm_assert(!ip_data->domains.has_default_route_exclusive);
+        nm_assert(!ip_data->domains.has_default_route);
+    }
+#endif
+
+    c_list_for_each_entry (ip_data, head, ip_config_lst) {
+        NMIPConfig *ip_config    = ip_data->ip_config;
+        gboolean    add_wildcard = FALSE;
+
+        if (!nm_ip_config_get_num_nameservers(ip_config))
+            continue;
+        if (nm_ip_config_best_default_route_get(ip_config))
+            add_wildcard = TRUE;
+        else {
+            /* If a VPN has never-default=no but doesn't get a default
+             * route (this can happen for example when the server
+             * pushes routes with openconnect), and there are no
+             * search or routing domains, then the name servers pushed
+             * by the server would be unused. It is preferable in this
+             * case to use the VPN DNS server for all queries. */
+            if (ip_data->ip_config_type == NM_DNS_IP_CONFIG_TYPE_VPN
+                && !nm_ip_config_get_never_default(ip_data->ip_config)
+                && nm_ip_config_get_num_searches(ip_data->ip_config) == 0
+                && nm_ip_config_get_num_domains(ip_data->ip_config) == 0)
+                add_wildcard = TRUE;
+        }
+
+        if (add_wildcard) {
+            if (!wildcard_entries)
+                wildcard_entries = g_hash_table_new(nm_direct_hash, NULL);
+            g_hash_table_add(wildcard_entries, ip_data);
+        }
+    }
+
+    c_list_for_each_entry (ip_data, head, ip_config_lst) {
+        NMIPConfig * ip_config = ip_data->ip_config;
+        int          priority;
+        const char **domains;
+        guint        n_searches;
+        guint        n_domains;
+        guint        num_dom1;
+        guint        num_dom2;
+        guint        n_domains_allocated;
+        guint        i;
+        gboolean     has_default_route_maybe    = FALSE;
+        gboolean     has_default_route_explicit = FALSE;
+        gboolean     has_default_route_auto     = FALSE;
+
+        if (!nm_ip_config_get_num_nameservers(ip_config))
+            continue;
+
+        n_searches = nm_ip_config_get_num_searches(ip_config);
+        n_domains  = nm_ip_config_get_num_domains(ip_config);
+
+        priority = nm_ip_config_get_dns_priority(ip_config);
+
+        nm_assert(priority != 0);
+        nm_assert(prev_priority <= priority);
+        prev_priority = priority;
+
+        /* Add wildcard lookup domain to connections with the default route.
+         * If there is no default route, add the wildcard domain to all non-VPN
+         * connections */
+        if (wildcard_entries) {
+            /* FIXME: this heuristic of which device has a default route does
+             * not work with policy routing (as used by default with WireGuard).
+             * We should have a more stable mechanism where an NMIPConfig indicates
+             * whether it is suitable for certain operations (like having an automatically
+             * added "~" domain). */
+            if (g_hash_table_contains(wildcard_entries, ip_data))
+                has_default_route_maybe = TRUE;
+        } else {
+            if (ip_data->ip_config_type != NM_DNS_IP_CONFIG_TYPE_VPN)
+                has_default_route_maybe = TRUE;
+        }
+
+        n_domains_allocated = (n_searches > 0 ? n_searches : n_domains) + 1u;
+        domains             = g_new(const char *, n_domains_allocated);
+
+        num_dom1 = 0;
+
+        /* searches are preferred over domains */
+        if (n_searches > 0) {
+            for (i = 0; i < n_searches; i++)
+                domains[num_dom1++] = nm_ip_config_get_search(ip_config, i);
+        } else {
+            for (i = 0; i < n_domains; i++)
+                domains[num_dom1++] = nm_ip_config_get_domain(ip_config, i);
+        }
+
+        nm_assert(num_dom1 < n_domains_allocated);
+
+        num_dom2 = 0;
+        for (i = 0; TRUE; i++) {
+            const char *domain_full;
+            const char *domain_clean;
+            const char *parent;
+            int         old_priority;
+            int         parent_priority;
+            gboolean    check_default_route;
+
+            if (i < num_dom1) {
+                check_default_route = FALSE;
+                domain_full         = domains[i];
+                domain_clean        = nm_utils_parse_dns_domain(domains[i], NULL);
+            } else if (i == num_dom1) {
+                if (!has_default_route_maybe)
+                    continue;
+                if (has_default_route_explicit)
+                    continue;
+                check_default_route = TRUE;
+                domain_full         = "~";
+                domain_clean        = "";
+            } else
+                break;
+
+            /* Remove domains with lower priority */
+            if (_domain_track_get_priority(ht, domain_clean, &old_priority)) {
+                nm_assert(old_priority <= priority);
+                if (old_priority < priority) {
+                    _LOGT("plugin: drop domain %s%s%s (i=%d, p=%d) because it already exists "
+                          "with p=%d",
+                          NM_PRINT_FMT_QUOTED(!check_default_route,
+                                              "'",
+                                              domain_full,
+                                              "'",
+                                              "<auto-default>"),
+                          ip_data->data->ifindex,
+                          priority,
+                          old_priority);
+                    continue;
+                }
+            } else if (_domain_track_is_shadowed(ht,
+                                                 domain_clean,
+                                                 priority,
+                                                 &parent,
+                                                 &parent_priority)) {
+                _LOGT("plugin: drop domain %s%s%s (i=%d, p=%d) shadowed by '%s' (p=%d)",
+                      NM_PRINT_FMT_QUOTED(!check_default_route,
+                                          "'",
+                                          domain_full,
+                                          "'",
+                                          "<auto-default>"),
+                      ip_data->data->ifindex,
+                      priority,
+                      parent,
+                      parent_priority);
+                continue;
+            }
+
+            _LOGT(
+                "plugin: add domain %s%s%s (i=%d, p=%d)",
+                NM_PRINT_FMT_QUOTED(!check_default_route, "'", domain_full, "'", "<auto-default>"),
+                ip_data->data->ifindex,
+                priority);
+
+            if (!ht)
+                ht = g_hash_table_new(nm_str_hash, g_str_equal);
+            g_hash_table_insert(ht, (gpointer) domain_clean, GINT_TO_POINTER(priority));
+
+            if (check_default_route)
+                has_default_route_auto = TRUE;
+            else {
+                nm_assert(num_dom2 <= num_dom1);
+                nm_assert(num_dom2 < n_domains_allocated);
+                domains[num_dom2++] = domain_full;
+                if (domain_clean[0] == '\0')
+                    has_default_route_explicit = TRUE;
+            }
+        }
+        nm_assert(num_dom2 < n_domains_allocated);
+        domains[num_dom2] = NULL;
+
+        nm_assert(!ip_data->domains.search);
+        nm_assert(!ip_data->domains.reverse);
+        ip_data->domains.search                     = domains;
+        ip_data->domains.reverse                    = get_ip_rdns_domains(ip_config);
+        ip_data->domains.has_default_route_explicit = has_default_route_explicit;
+        ip_data->domains.has_default_route_exclusive =
+            has_default_route_explicit || (priority < 0 && has_default_route_auto);
+        ip_data->domains.has_default_route =
+            ip_data->domains.has_default_route_exclusive || has_default_route_auto;
+
+        {
+            gs_free char *str1 = NULL;
+            gs_free char *str2 = NULL;
+
+            _LOGT("plugin: settings: ifindex=%d, priority=%d, default-route=%d%s, search=%s, "
+                  "reverse=%s",
+                  ip_data->data->ifindex,
+                  priority,
+                  ip_data->domains.has_default_route,
+                  ip_data->domains.has_default_route_explicit
+                      ? " (explicit)"
+                      : (ip_data->domains.has_default_route_exclusive ? " (exclusive)" : ""),
+                  (str1 = g_strjoinv(",", (char **) ip_data->domains.search)),
+                  (ip_data->domains.reverse ? (str2 = g_strjoinv(",", ip_data->domains.reverse))
+                                            : ""));
+        }
+    }
+}
+
+static void
+_mgr_configs_data_clear(NMDnsManager *self)
+{
+    NMDnsConfigIPData *ip_data;
+    CList *            head;
+
+    head = _mgr_get_ip_configs_lst_head(self);
+    c_list_for_each_entry (ip_data, head, ip_config_lst) {
+        nm_clear_g_free(&ip_data->domains.search);
+        nm_clear_pointer(&ip_data->domains.reverse, g_strfreev);
+        ip_data->domains.has_default_route_explicit  = FALSE;
+        ip_data->domains.has_default_route_exclusive = FALSE;
+        ip_data->domains.has_default_route           = FALSE;
+    }
+}
+
+/*****************************************************************************/
+
+static gboolean
+update_dns(NMDnsManager *self, gboolean no_caching, GError **error)
+{
+    NMDnsManagerPrivate *priv                = NM_DNS_MANAGER_GET_PRIVATE(self);
+    const char *         nis_domain          = NULL;
+    gs_strfreev char **  searches            = NULL;
+    gs_strfreev char **  options             = NULL;
+    gs_strfreev char **  nameservers         = NULL;
+    gs_strfreev char **  nis_servers         = NULL;
+    gboolean             caching             = FALSE;
+    gboolean             do_update           = TRUE;
+    gboolean             resolv_conf_updated = FALSE;
+    SpawnResult          result              = SR_SUCCESS;
+    NMConfigData *       data;
+    NMGlobalDnsConfig *  global_config;
+    gs_free_error GError *local_error   = NULL;
+    GError **const        p_local_error = error ? &local_error : NULL;
+
+    nm_assert(!error || !*error);
+
+    if (priv->is_stopped) {
+        _LOGD("update-dns: not updating resolv.conf (is stopped)");
+        return TRUE;
+    }
+
+    nm_clear_g_source(&priv->plugin_ratelimit.timer);
+
+    if (NM_IN_SET(priv->rc_manager,
+                  NM_DNS_MANAGER_RESOLV_CONF_MAN_UNMANAGED,
+                  NM_DNS_MANAGER_RESOLV_CONF_MAN_IMMUTABLE)) {
+        do_update = FALSE;
+        _LOGD("update-dns: not updating resolv.conf");
+    } else {
+        priv->dns_touched = TRUE;
+        _LOGD("update-dns: updating resolv.conf");
+    }
+
+    data          = nm_config_get_data(priv->config);
+    global_config = nm_config_data_get_global_dns_config(data);
+
+    /* Update hash with config we're applying */
+    compute_hash(self, global_config, priv->hash);
+
+    _collect_resolv_conf_data(self,
+                              global_config,
+                              &searches,
+                              &options,
+                              &nameservers,
+                              &nis_servers,
+                              &nis_domain);
+
+    if (priv->plugin || priv->sd_resolve_plugin)
+        _mgr_configs_data_construct(self);
+
+    if (priv->sd_resolve_plugin) {
+        nm_dns_plugin_update(priv->sd_resolve_plugin,
+                             global_config,
+                             _mgr_get_ip_configs_lst_head(self),
+                             priv->hostname,
+                             NULL);
+    }
+
+    /* Let any plugins do their thing first */
+    if (priv->plugin) {
+        NMDnsPlugin * plugin               = priv->plugin;
+        const char *  plugin_name          = nm_dns_plugin_get_name(plugin);
+        gs_free_error GError *plugin_error = NULL;
+
+        if (nm_dns_plugin_is_caching(plugin)) {
+            if (no_caching) {
+                _LOGD("update-dns: plugin %s ignored (caching disabled)", plugin_name);
+                goto plugin_skip;
+            }
+            caching = TRUE;
+        }
+
+        _LOGD("update-dns: updating plugin %s", plugin_name);
+        if (!nm_dns_plugin_update(plugin,
+                                  global_config,
+                                  _mgr_get_ip_configs_lst_head(self),
+                                  priv->hostname,
+                                  &plugin_error)) {
+            _LOGW("update-dns: plugin %s update failed: %s", plugin_name, plugin_error->message);
+
+            /* If the plugin failed to update, we shouldn't write out a local
+             * caching DNS configuration to resolv.conf.
+             */
+            caching = FALSE;
+        }
+
+plugin_skip:;
+    }
+
+    /* Clear the generated search list as it points to
+     * strings owned by IP configurations and we can't
+     * guarantee they stay alive. */
+    _mgr_configs_data_clear(self);
+
+    update_resolv_conf_no_stub(self,
+                               NM_CAST_STRV_CC(searches),
+                               NM_CAST_STRV_CC(nameservers),
+                               NM_CAST_STRV_CC(options));
+
+    /* If caching was successful, we only send 127.0.0.1 to /etc/resolv.conf
+     * to ensure that the glibc resolver doesn't try to round-robin nameservers,
+     * but only uses the local caching nameserver.
+     */
+    if (caching) {
+        const char *lladdr = "127.0.0.1";
+        gboolean    need_edns0;
+        gboolean    need_trust;
+
+        if (NM_IS_DNS_SYSTEMD_RESOLVED(priv->plugin)) {
+            /* systemd-resolved uses a different link-local address */
+            lladdr = "127.0.0.53";
+        }
+
+        g_strfreev(nameservers);
+        nameservers    = g_new0(char *, 2);
+        nameservers[0] = g_strdup(lladdr);
+
+        need_edns0 = nm_utils_strv_find_first(options, -1, NM_SETTING_DNS_OPTION_EDNS0) < 0;
+        need_trust = nm_utils_strv_find_first(options, -1, NM_SETTING_DNS_OPTION_TRUST_AD) < 0;
+
+        if (need_edns0 || need_trust) {
+            gsize len;
+
+            len     = NM_PTRARRAY_LEN(options);
+            options = g_realloc(options, sizeof(char *) * (len + 3u));
+            if (need_edns0)
+                options[len++] = g_strdup(NM_SETTING_DNS_OPTION_EDNS0);
+            if (need_trust)
+                options[len++] = g_strdup(NM_SETTING_DNS_OPTION_TRUST_AD);
+            options[len] = NULL;
+        }
+    }
+
+    if (do_update) {
+        switch (priv->rc_manager) {
+        case NM_DNS_MANAGER_RESOLV_CONF_MAN_SYMLINK:
+        case NM_DNS_MANAGER_RESOLV_CONF_MAN_FILE:
+            result              = update_resolv_conf(self,
+                                        NM_CAST_STRV_CC(searches),
+                                        NM_CAST_STRV_CC(nameservers),
+                                        NM_CAST_STRV_CC(options),
+                                        p_local_error,
+                                        priv->rc_manager);
+            resolv_conf_updated = TRUE;
+            /* If we have ended with no nameservers avoid updating again resolv.conf
+             * on stop, as some external changes may be applied to it in the meanwhile */
+            if (!nameservers && !options)
+                priv->dns_touched = FALSE;
+            break;
+        case NM_DNS_MANAGER_RESOLV_CONF_MAN_RESOLVCONF:
+            result = dispatch_resolvconf(self, searches, nameservers, options, p_local_error);
+            break;
+        case NM_DNS_MANAGER_RESOLV_CONF_MAN_NETCONFIG:
+            result = dispatch_netconfig(self,
+                                        (const char *const *) searches,
+                                        (const char *const *) nameservers,
+                                        nis_domain,
+                                        (const char *const *) nis_servers,
+                                        p_local_error);
+            break;
+        default:
+            nm_assert_not_reached();
+        }
+
+        if (result == SR_NOTFOUND) {
+            _LOGD("update-dns: program not available, writing to resolv.conf");
+            g_clear_error(&local_error);
+            result              = update_resolv_conf(self,
+                                        NM_CAST_STRV_CC(searches),
+                                        NM_CAST_STRV_CC(nameservers),
+                                        NM_CAST_STRV_CC(options),
+                                        p_local_error,
+                                        NM_DNS_MANAGER_RESOLV_CONF_MAN_SYMLINK);
+            resolv_conf_updated = TRUE;
+        }
+    }
+
+    /* Unless we've already done it, update private resolv.conf in NMRUNDIR
+     * ignoring any errors */
+    if (!resolv_conf_updated) {
+        update_resolv_conf(self,
+                           NM_CAST_STRV_CC(searches),
+                           NM_CAST_STRV_CC(nameservers),
+                           NM_CAST_STRV_CC(options),
+                           NULL,
+                           NM_DNS_MANAGER_RESOLV_CONF_MAN_UNMANAGED);
+    }
+
+    /* signal that resolv.conf was changed */
+    if (do_update && result == SR_SUCCESS)
+        g_signal_emit(self, signals[CONFIG_CHANGED], 0);
+
+    nm_clear_pointer(&priv->config_variant, g_variant_unref);
+    _notify(self, PROP_CONFIGURATION);
+
+    if (result != SR_SUCCESS) {
+        if (error)
+            g_propagate_error(error, g_steal_pointer(&local_error));
+        return FALSE;
+    }
+
+    nm_assert(!local_error);
+    return TRUE;
+}
+
+/*****************************************************************************/
+
+static void
+_ip_config_dns_priority_changed(gpointer config, GParamSpec *pspec, NMDnsConfigIPData *ip_data)
+{
+    _ASSERT_dns_config_ip_data(ip_data);
+
+    NM_DNS_MANAGER_GET_PRIVATE(ip_data->data->self)->ip_configs_lst_need_sort = TRUE;
+}
+
+gboolean
+nm_dns_manager_set_ip_config(NMDnsManager *    self,
+                             NMIPConfig *      ip_config,
+                             NMDnsIPConfigType ip_config_type)
+{
+    NMDnsManagerPrivate *priv;
+    NMDnsConfigIPData *  ip_data;
+    NMDnsConfigData *    data;
+    int                  ifindex;
+    NMDnsConfigIPData ** p_best;
+
+    g_return_val_if_fail(NM_IS_DNS_MANAGER(self), FALSE);
+    g_return_val_if_fail(NM_IS_IP_CONFIG(ip_config), FALSE);
+
+    ifindex = nm_ip_config_get_ifindex(ip_config);
+    g_return_val_if_fail(ifindex > 0, FALSE);
+
+    priv = NM_DNS_MANAGER_GET_PRIVATE(self);
+
+    data = g_hash_table_lookup(priv->configs_dict, &ifindex);
+    if (!data)
+        ip_data = NULL;
+    else
+        ip_data = _dns_config_data_find_ip_config(data, ip_config);
+
+    if (ip_config_type == NM_DNS_IP_CONFIG_TYPE_REMOVED) {
+        if (!ip_data)
+            return FALSE;
+        if (priv->best_ip_config_4 == ip_data)
+            priv->best_ip_config_4 = NULL;
+        if (priv->best_ip_config_6 == ip_data)
+            priv->best_ip_config_6 = NULL;
+        /* deleting a config doesn't invalidate the configs' sort order. */
+        _dns_config_ip_data_free(ip_data);
+        if (c_list_is_empty(&data->data_lst_head))
+            g_hash_table_remove(priv->configs_dict, &ifindex);
+        goto changed;
+    }
+
+    if (ip_data && ip_data->ip_config_type == ip_config_type) {
+        /* nothing to do. */
+        return FALSE;
+    }
+
+    if (!data) {
+        data  = g_slice_new(NMDnsConfigData);
+        *data = (NMDnsConfigData){
+            .ifindex       = ifindex,
+            .self          = self,
+            .data_lst_head = C_LIST_INIT(data->data_lst_head),
+        };
+        _ASSERT_dns_config_data(data);
+        g_hash_table_add(priv->configs_dict, data);
+        c_list_link_tail(&priv->configs_lst_head, &data->configs_lst);
+        priv->configs_lst_need_sort = TRUE;
+    }
+
+    if (!ip_data)
+        ip_data = _dns_config_ip_data_new(data, ip_config, ip_config_type);
+    else
+        ip_data->ip_config_type = ip_config_type;
+
+    priv->ip_configs_lst_need_sort = TRUE;
+
+    p_best = NM_IS_IP4_CONFIG(ip_config) ? &priv->best_ip_config_4 : &priv->best_ip_config_6;
+
+    if (ip_config_type == NM_DNS_IP_CONFIG_TYPE_BEST_DEVICE) {
+        /* Only one best-device per IP version is allowed */
+        if (*p_best != ip_data) {
+            if (*p_best)
+                (*p_best)->ip_config_type = NM_DNS_IP_CONFIG_TYPE_DEFAULT;
+            *p_best = ip_data;
+        }
+    } else {
+        if (*p_best == ip_data)
+            *p_best = NULL;
+    }
+
+changed:
+    if (!priv->updates_queue) {
+        gs_free_error GError *error = NULL;
+
+        if (!update_dns(self, FALSE, &error))
+            _LOGW("could not commit DNS changes: %s", error->message);
+    }
+
+    return TRUE;
+}
+
+void
+nm_dns_manager_set_initial_hostname(NMDnsManager *self, const char *hostname)
+{
+    NMDnsManagerPrivate *priv = NM_DNS_MANAGER_GET_PRIVATE(self);
+
+    g_free(priv->hostname);
+    priv->hostname = g_strdup(hostname);
+}
+
+void
+nm_dns_manager_set_hostname(NMDnsManager *self, const char *hostname, gboolean skip_update)
+{
+    NMDnsManagerPrivate *priv     = NM_DNS_MANAGER_GET_PRIVATE(self);
+    const char *         filtered = NULL;
+
+    /* Certain hostnames we don't want to include in resolv.conf 'searches' */
+    if (hostname && nm_utils_is_specific_hostname(hostname) && !strstr(hostname, ".in-addr.arpa")
+        && strchr(hostname, '.')) {
+        filtered = hostname;
+    }
+
+    if ((!priv->hostname && !filtered)
+        || (priv->hostname && filtered && !strcmp(priv->hostname, filtered)))
+        return;
+
+    g_free(priv->hostname);
+    priv->hostname = g_strdup(filtered);
+
+    if (skip_update)
+        return;
+
+    if (!priv->updates_queue) {
+        gs_free_error GError *error = NULL;
+
+        if (!update_dns(self, FALSE, &error))
+            _LOGW("could not commit DNS changes: %s", error->message);
+    }
+}
+
+void
+nm_dns_manager_begin_updates(NMDnsManager *self, const char *func)
+{
+    NMDnsManagerPrivate *priv;
+
+    g_return_if_fail(self != NULL);
+    priv = NM_DNS_MANAGER_GET_PRIVATE(self);
+
+    /* Save current hash when starting a new batch */
+    if (priv->updates_queue == 0)
+        memcpy(priv->prev_hash, priv->hash, sizeof(priv->hash));
+
+    priv->updates_queue++;
+
+    _LOGD("(%s): queueing DNS updates (%d)", func, priv->updates_queue);
+}
+
+void
+nm_dns_manager_end_updates(NMDnsManager *self, const char *func)
+{
+    NMDnsManagerPrivate *priv;
+    gs_free_error GError *error = NULL;
+    gboolean              changed;
+    guint8 new[HASH_LEN];
+
+    g_return_if_fail(self != NULL);
+
+    priv = NM_DNS_MANAGER_GET_PRIVATE(self);
+    g_return_if_fail(priv->updates_queue > 0);
+
+    compute_hash(self, nm_config_data_get_global_dns_config(nm_config_get_data(priv->config)), new);
+    changed = (memcmp(new, priv->prev_hash, sizeof(new)) != 0) ? TRUE : FALSE;
+    _LOGD("(%s): DNS configuration %s", func, changed ? "changed" : "did not change");
+
+    priv->updates_queue--;
+    if ((priv->updates_queue > 0) || (changed == FALSE)) {
+        _LOGD("(%s): no DNS changes to commit (%d)", func, priv->updates_queue);
+        return;
+    }
+
+    /* Commit all the outstanding changes */
+    _LOGD("(%s): committing DNS changes (%d)", func, priv->updates_queue);
+    if (!update_dns(self, FALSE, &error))
+        _LOGW("could not commit DNS changes: %s", error->message);
+
+    memset(priv->prev_hash, 0, sizeof(priv->prev_hash));
+}
+
+void
+nm_dns_manager_stop(NMDnsManager *self)
+{
+    NMDnsManagerPrivate *priv;
+
+    priv = NM_DNS_MANAGER_GET_PRIVATE(self);
+
+    if (priv->is_stopped)
+        g_return_if_reached();
+
+    _LOGT("stopping...");
+
+    /* If we're quitting, leave a valid resolv.conf in place, not one
+     * pointing to 127.0.0.1 if dnsmasq was active.  But if we haven't
+     * done any DNS updates yet, there's no reason to touch resolv.conf
+     * on shutdown.
+     */
+    if (priv->dns_touched && priv->plugin && NM_IS_DNS_DNSMASQ(priv->plugin)) {
+        gs_free_error GError *error = NULL;
+
+        if (!update_dns(self, TRUE, &error))
+            _LOGW("could not commit DNS changes on shutdown: %s", error->message);
+
+        priv->dns_touched = FALSE;
+    }
+
+    priv->is_stopped = TRUE;
+}
+
+/*****************************************************************************/
+
+static gboolean
+_clear_plugin(NMDnsManager *self)
+{
+    NMDnsManagerPrivate *priv = NM_DNS_MANAGER_GET_PRIVATE(self);
+
+    priv->plugin_ratelimit.ts = 0;
+    nm_clear_g_source(&priv->plugin_ratelimit.timer);
+
+    if (priv->plugin) {
+        nm_dns_plugin_stop(priv->plugin);
+        g_clear_object(&priv->plugin);
+        return TRUE;
+    }
+    return FALSE;
+}
+
+static NMDnsManagerResolvConfManager
+_check_resconf_immutable(NMDnsManagerResolvConfManager rc_manager)
+{
+    struct stat st;
+    int         fd, flags;
+    bool        immutable = FALSE;
+
+    switch (rc_manager) {
+    case NM_DNS_MANAGER_RESOLV_CONF_MAN_UNKNOWN:
+    case NM_DNS_MANAGER_RESOLV_CONF_MAN_IMMUTABLE:
+        nm_assert_not_reached();
+        /* fall-through */
+    case NM_DNS_MANAGER_RESOLV_CONF_MAN_UNMANAGED:
+        return NM_DNS_MANAGER_RESOLV_CONF_MAN_UNMANAGED;
+    default:
+
+        if (lstat(_PATH_RESCONF, &st) != 0)
+            return rc_manager;
+
+        if (S_ISLNK(st.st_mode)) {
+            /* only regular files and directories can have extended file attributes. */
+            switch (rc_manager) {
+            case NM_DNS_MANAGER_RESOLV_CONF_MAN_SYMLINK:
+                /* we don't care whether the link-target is immutable.
+                 * If the symlink points to another file, rc-manager=symlink anyway backs off.
+                 * Otherwise, we would only check whether our internal resolv.conf is immutable. */
+                return NM_DNS_MANAGER_RESOLV_CONF_MAN_SYMLINK;
+            case NM_DNS_MANAGER_RESOLV_CONF_MAN_UNKNOWN:
+            case NM_DNS_MANAGER_RESOLV_CONF_MAN_UNMANAGED:
+            case NM_DNS_MANAGER_RESOLV_CONF_MAN_IMMUTABLE:
+                nm_assert_not_reached();
+                /* fall-through */
+            case NM_DNS_MANAGER_RESOLV_CONF_MAN_FILE:
+            case NM_DNS_MANAGER_RESOLV_CONF_MAN_RESOLVCONF:
+            case NM_DNS_MANAGER_RESOLV_CONF_MAN_NETCONFIG:
+            case NM_DNS_MANAGER_RESOLV_CONF_MAN_AUTO:
+                break;
+            }
+        }
+
+        fd = open(_PATH_RESCONF, O_RDONLY | O_CLOEXEC);
+        if (fd != -1) {
+            if (ioctl(fd, FS_IOC_GETFLAGS, &flags) != -1)
+                immutable = NM_FLAGS_HAS(flags, FS_IMMUTABLE_FL);
+            nm_close(fd);
+        }
+        return immutable ? NM_DNS_MANAGER_RESOLV_CONF_MAN_IMMUTABLE : rc_manager;
+    }
+}
+
+static gboolean
+_resolvconf_resolved_managed(void)
+{
+    static const char *const RESOLVED_PATHS[] = {
+        "../run/systemd/resolve/stub-resolv.conf",
+        "../run/systemd/resolve/resolv.conf",
+        "../lib/systemd/resolv.conf",
+        "../usr/lib/systemd/resolv.conf",
+        "/run/systemd/resolve/stub-resolv.conf",
+        "/run/systemd/resolve/resolv.conf",
+        "/lib/systemd/resolv.conf",
+        "/usr/lib/systemd/resolv.conf",
+    };
+    struct stat st, st_test;
+    guint       i;
+
+    if (lstat(_PATH_RESCONF, &st) != 0)
+        return FALSE;
+
+    if (S_ISLNK(st.st_mode)) {
+        gs_free char *     full_path = NULL;
+        nm_auto_free char *real_path = NULL;
+
+        /* see if resolv.conf is a symlink with a target that is
+         * exactly like one of the candidates.
+         *
+         * This check will work for symlinks, even if the target
+         * does not exist and realpath() cannot resolve anything.
+         *
+         * We want to handle that, because systemd-resolved might not
+         * have started yet. */
+        full_path = g_file_read_link(_PATH_RESCONF, NULL);
+        if (nm_utils_strv_find_first((char **) RESOLVED_PATHS,
+                                     G_N_ELEMENTS(RESOLVED_PATHS),
+                                     full_path)
+            >= 0)
+            return TRUE;
+
+        /* see if resolv.conf is a symlink that resolves exactly one
+         * of the candidate paths.
+         *
+         * This check will work for symlinks that can be resolved
+         * to a realpath, but the actual file might not exist.
+         *
+         * We want to handle that, because systemd-resolved might not
+         * have started yet. */
+        real_path = realpath(_PATH_RESCONF, NULL);
+        if (nm_utils_strv_find_first((char **) RESOLVED_PATHS,
+                                     G_N_ELEMENTS(RESOLVED_PATHS),
+                                     real_path)
+            >= 0)
+            return TRUE;
+
+        /* fall-through and resolve the symlink, to check the file
+         * it points to (below).
+         *
+         * This check is the most reliable, but it only works if
+         * systemd-resolved already started and created the file. */
+        if (stat(_PATH_RESCONF, &st) != 0)
+            return FALSE;
+    }
+
+    /* see if resolv.conf resolves to one of the candidate
+     * paths (or whether it is hard-linked). */
+    for (i = 0; i < G_N_ELEMENTS(RESOLVED_PATHS); i++) {
+        const char *p = RESOLVED_PATHS[i];
+
+        if (p[0] == '/' && stat(p, &st_test) == 0 && st.st_dev == st_test.st_dev
+            && st.st_ino == st_test.st_ino)
+            return TRUE;
+    }
+
+    return FALSE;
+}
+
+static void
+init_resolv_conf_mode(NMDnsManager *self, gboolean force_reload_plugin)
+{
+    NMDnsManagerPrivate *         priv = NM_DNS_MANAGER_GET_PRIVATE(self);
+    NMDnsManagerResolvConfManager rc_manager;
+    const char *                  mode;
+    gboolean                      systemd_resolved;
+    gboolean                      param_changed            = FALSE;
+    gboolean                      plugin_changed           = FALSE;
+    gboolean                      systemd_resolved_changed = FALSE;
+    gboolean                      rc_manager_was_auto      = FALSE;
+
+    mode             = nm_config_data_get_dns_mode(nm_config_get_data(priv->config));
+    systemd_resolved = nm_config_data_get_systemd_resolved(nm_config_get_data(priv->config));
+
+    if (nm_streq0(mode, "none"))
+        rc_manager = NM_DNS_MANAGER_RESOLV_CONF_MAN_UNMANAGED;
+    else {
+        const char *man;
+
+        rc_manager = NM_DNS_MANAGER_RESOLV_CONF_MAN_UNKNOWN;
+        man        = nm_config_data_get_rc_manager(nm_config_get_data(priv->config));
+
+again:
+        if (!man) {
+            /* nop */
+        } else if (nm_streq(man, "auto"))
+            rc_manager = NM_DNS_MANAGER_RESOLV_CONF_MAN_AUTO;
+        else if (NM_IN_STRSET(man, "symlink", "none"))
+            rc_manager = NM_DNS_MANAGER_RESOLV_CONF_MAN_SYMLINK;
+        else if (nm_streq(man, "file"))
+            rc_manager = NM_DNS_MANAGER_RESOLV_CONF_MAN_FILE;
+        else if (nm_streq(man, "resolvconf"))
+            rc_manager = NM_DNS_MANAGER_RESOLV_CONF_MAN_RESOLVCONF;
+        else if (nm_streq(man, "netconfig"))
+            rc_manager = NM_DNS_MANAGER_RESOLV_CONF_MAN_NETCONFIG;
+        else if (nm_streq(man, "unmanaged"))
+            rc_manager = NM_DNS_MANAGER_RESOLV_CONF_MAN_UNMANAGED;
+
+        if (rc_manager == NM_DNS_MANAGER_RESOLV_CONF_MAN_UNKNOWN) {
+            if (man) {
+                _LOGW("init: unknown resolv.conf manager \"%s\", fallback to \"%s\"",
+                      man,
+                      "" NM_CONFIG_DEFAULT_MAIN_RC_MANAGER);
+            }
+            man        = "" NM_CONFIG_DEFAULT_MAIN_RC_MANAGER;
+            rc_manager = NM_DNS_MANAGER_RESOLV_CONF_MAN_AUTO;
+            goto again;
+        }
+    }
+
+    rc_manager = _check_resconf_immutable(rc_manager);
+
+    if ((!mode && _resolvconf_resolved_managed()) || nm_streq0(mode, "systemd-resolved")) {
+        if (force_reload_plugin || !NM_IS_DNS_SYSTEMD_RESOLVED(priv->plugin)) {
+            _clear_plugin(self);
+            priv->plugin   = nm_dns_systemd_resolved_new();
+            plugin_changed = TRUE;
+        }
+        mode             = "systemd-resolved";
+        systemd_resolved = FALSE;
+    } else if (nm_streq0(mode, "dnsmasq")) {
+        if (force_reload_plugin || !NM_IS_DNS_DNSMASQ(priv->plugin)) {
+            _clear_plugin(self);
+            priv->plugin   = nm_dns_dnsmasq_new();
+            plugin_changed = TRUE;
+        }
+    } else if (nm_streq0(mode, "unbound")) {
+        if (force_reload_plugin || !NM_IS_DNS_UNBOUND(priv->plugin)) {
+            _clear_plugin(self);
+            priv->plugin   = nm_dns_unbound_new();
+            plugin_changed = TRUE;
+        }
+    } else {
+        if (!NM_IN_STRSET(mode, "none", "default")) {
+            if (mode)
+                _LOGW("init: unknown dns mode '%s'", mode);
+            mode = "default";
+        }
+        if (_clear_plugin(self))
+            plugin_changed = TRUE;
+    }
+
+    if (rc_manager == NM_DNS_MANAGER_RESOLV_CONF_MAN_AUTO) {
+        rc_manager_was_auto = TRUE;
+        if (nm_streq(mode, "systemd-resolved"))
+            rc_manager = NM_DNS_MANAGER_RESOLV_CONF_MAN_UNMANAGED;
+        else if (HAS_RESOLVCONF && g_file_test(RESOLVCONF_PATH, G_FILE_TEST_IS_EXECUTABLE)) {
+            /* We detect /sbin/resolvconf only at this stage. That means, if you install
+             * or uninstall openresolv afterwards, you need to reload the DNS settings
+             * (with SIGHUP or `systemctl reload NetworkManager.service`).
+             *
+             * We only accept resolvconf if NetworkManager was built with --with-resolvconf.
+             * For example, on Fedora the systemd package provides a compat resolvconf
+             * implementation for systemd-resolved. But using that never makes sense, because
+             * there we either use full systemd-resolved mode or not. In no case does it
+             * make sense to call that resolvconf implementation. */
+            rc_manager = NM_DNS_MANAGER_RESOLV_CONF_MAN_RESOLVCONF;
+        } else if (HAS_NETCONFIG && g_file_test(NETCONFIG_PATH, G_FILE_TEST_IS_EXECUTABLE)) {
+            /* Like for resolvconf, we detect only once. We only autoenable this
+             * option, if NetworkManager was built with netconfig explicitly enabled. */
+            rc_manager = NM_DNS_MANAGER_RESOLV_CONF_MAN_NETCONFIG;
+        } else
+            rc_manager = NM_DNS_MANAGER_RESOLV_CONF_MAN_SYMLINK;
+    }
+
+    /* The systemd-resolved plugin is special. We typically always want to keep
+     * systemd-resolved up to date even if the configured plugin is different. */
+    if (systemd_resolved) {
+        if (!priv->sd_resolve_plugin) {
+            priv->sd_resolve_plugin  = nm_dns_systemd_resolved_new();
+            systemd_resolved_changed = TRUE;
+        }
+    } else if (nm_clear_g_object(&priv->sd_resolve_plugin))
+        systemd_resolved_changed = TRUE;
+
+    g_object_freeze_notify(G_OBJECT(self));
+
+    if (!nm_streq0(priv->mode, mode)) {
+        g_free(priv->mode);
+        priv->mode    = g_strdup(mode);
+        param_changed = TRUE;
+        _notify(self, PROP_MODE);
+    }
+
+    if (priv->rc_manager != rc_manager) {
+        priv->rc_manager = rc_manager;
+        param_changed    = TRUE;
+        _notify(self, PROP_RC_MANAGER);
+    }
+
+    if (param_changed || plugin_changed || systemd_resolved_changed) {
+        _LOGI("init: dns=%s%s rc-manager=%s%s%s%s%s",
+              mode,
+              (systemd_resolved ? ",systemd-resolved" : ""),
+              _rc_manager_to_string(rc_manager),
+              rc_manager_was_auto ? " (auto)" : "",
+              NM_PRINT_FMT_QUOTED(priv->plugin,
+                                  ", plugin=",
+                                  nm_dns_plugin_get_name(priv->plugin),
+                                  "",
+                                  ""));
+    }
+
+    g_object_thaw_notify(G_OBJECT(self));
+}
+
+static void
+config_changed_cb(NMConfig *          config,
+                  NMConfigData *      config_data,
+                  NMConfigChangeFlags changes,
+                  NMConfigData *      old_data,
+                  NMDnsManager *      self)
+{
+    if (NM_FLAGS_ANY(changes,
+                     NM_CONFIG_CHANGE_DNS_MODE | NM_CONFIG_CHANGE_RC_MANAGER
+                         | NM_CONFIG_CHANGE_CAUSE_SIGHUP | NM_CONFIG_CHANGE_CAUSE_DNS_FULL)) {
+        /* reload the resolv-conf mode also on SIGHUP (when DNS_MODE didn't change).
+         * The reason is, that the configuration also depends on whether resolv.conf
+         * is immutable, thus, without the configuration changing, we always want to
+         * re-configure the mode. */
+        init_resolv_conf_mode(
+            self,
+            NM_FLAGS_ANY(changes, NM_CONFIG_CHANGE_CAUSE_SIGHUP | NM_CONFIG_CHANGE_CAUSE_DNS_FULL));
+    }
+
+    if (NM_FLAGS_ANY(changes,
+                     NM_CONFIG_CHANGE_CAUSE_SIGHUP | NM_CONFIG_CHANGE_CAUSE_SIGUSR1
+                         | NM_CONFIG_CHANGE_CAUSE_DNS_RC | NM_CONFIG_CHANGE_CAUSE_DNS_FULL
+                         | NM_CONFIG_CHANGE_DNS_MODE | NM_CONFIG_CHANGE_RC_MANAGER
+                         | NM_CONFIG_CHANGE_GLOBAL_DNS_CONFIG)) {
+        gs_free_error GError *error = NULL;
+
+        if (!update_dns(self, FALSE, &error))
+            _LOGW("could not commit DNS changes: %s", error->message);
+    }
+}
+
+static GVariant *
+_get_global_config_variant(NMGlobalDnsConfig *global)
+{
+    NMGlobalDnsDomain *domain;
+    GVariantBuilder    builder;
+    guint              i, num;
+
+    g_variant_builder_init(&builder, G_VARIANT_TYPE("aa{sv}"));
+    num = nm_global_dns_config_get_num_domains(global);
+    for (i = 0; i < num; i++) {
+        GVariantBuilder    conf_builder;
+        GVariantBuilder    item_builder;
+        const char *       domain_name;
+        const char *const *servers;
+
+        g_variant_builder_init(&conf_builder, G_VARIANT_TYPE("a{sv}"));
+
+        domain      = nm_global_dns_config_get_domain(global, i);
+        domain_name = nm_global_dns_domain_get_name(domain);
+
+        if (domain_name && !nm_streq0(domain_name, "*")) {
+            g_variant_builder_init(&item_builder, G_VARIANT_TYPE("as"));
+            g_variant_builder_add(&item_builder, "s", domain_name);
+            g_variant_builder_add(&conf_builder,
+                                  "{sv}",
+                                  "domains",
+                                  g_variant_builder_end(&item_builder));
+        }
+
+        g_variant_builder_init(&item_builder, G_VARIANT_TYPE("as"));
+        for (servers = nm_global_dns_domain_get_servers(domain); *servers; servers++) {
+            g_variant_builder_add(&item_builder, "s", *servers);
+        }
+        g_variant_builder_add(&conf_builder,
+                              "{sv}",
+                              "nameservers",
+                              g_variant_builder_end(&item_builder));
+
+        g_variant_builder_add(&conf_builder,
+                              "{sv}",
+                              "priority",
+                              g_variant_new_int32(NM_DNS_PRIORITY_DEFAULT_NORMAL));
+
+        g_variant_builder_add(&builder, "a{sv}", &conf_builder);
+    }
+
+    return g_variant_ref_sink(g_variant_builder_end(&builder));
+}
+
+static GVariant *
+_get_config_variant(NMDnsManager *self)
+{
+    NMDnsManagerPrivate *priv = NM_DNS_MANAGER_GET_PRIVATE(self);
+    NMGlobalDnsConfig *  global_config;
+    gs_free char *       str = NULL;
+    GVariantBuilder      builder;
+    NMDnsConfigIPData *  ip_data;
+    const CList *        head;
+    gs_unref_ptrarray GPtrArray *array_domains = NULL;
+
+    if (priv->config_variant)
+        return priv->config_variant;
+
+    global_config = nm_config_data_get_global_dns_config(nm_config_get_data(priv->config));
+    if (global_config) {
+        priv->config_variant = _get_global_config_variant(global_config);
+        _LOGT("current configuration: %s", (str = g_variant_print(priv->config_variant, TRUE)));
+        return priv->config_variant;
+    }
+
+    g_variant_builder_init(&builder, G_VARIANT_TYPE("aa{sv}"));
+
+    head = _mgr_get_ip_configs_lst_head(self);
+    c_list_for_each_entry (ip_data, head, ip_config_lst) {
+        const NMIPConfig *ip_config = ip_data->ip_config;
+        GVariantBuilder   entry_builder;
+        GVariantBuilder   strv_builder;
+        guint             i, num;
+        const int         addr_family = nm_ip_config_get_addr_family(ip_config);
+        char              buf[NM_UTILS_INET_ADDRSTRLEN];
+        const NMIPAddr *  addr;
+        const char *      ifname;
+
+        num = nm_ip_config_get_num_nameservers(ip_config);
+        if (!num)
+            continue;
+
+        g_variant_builder_init(&entry_builder, G_VARIANT_TYPE("a{sv}"));
+
+        g_variant_builder_init(&strv_builder, G_VARIANT_TYPE("as"));
+        for (i = 0; i < num; i++) {
+            addr = nm_ip_config_get_nameserver(ip_config, i);
+            g_variant_builder_add(&strv_builder, "s", nm_utils_inet_ntop(addr_family, addr, buf));
+        }
+        g_variant_builder_add(&entry_builder,
+                              "{sv}",
+                              "nameservers",
+                              g_variant_builder_end(&strv_builder));
+
+        num = nm_ip_config_get_num_domains(ip_config);
+        num += nm_ip_config_get_num_searches(ip_config);
+        if (num > 0) {
+            if (!array_domains)
+                array_domains = g_ptr_array_sized_new(num);
+            else
+                g_ptr_array_set_size(array_domains, 0);
+
+            add_dns_domains(array_domains, ip_config, TRUE, FALSE);
+            if (array_domains->len) {
+                g_variant_builder_init(&strv_builder, G_VARIANT_TYPE("as"));
+                for (i = 0; i < array_domains->len; i++) {
+                    g_variant_builder_add(&strv_builder, "s", array_domains->pdata[i]);
+                }
+                g_variant_builder_add(&entry_builder,
+                                      "{sv}",
+                                      "domains",
+                                      g_variant_builder_end(&strv_builder));
+            }
+        }
+
+        ifname = nm_platform_link_get_name(NM_PLATFORM_GET, ip_data->data->ifindex);
+        if (ifname) {
+            g_variant_builder_add(&entry_builder,
+                                  "{sv}",
+                                  "interface",
+                                  g_variant_new_string(ifname));
+        }
+
+        g_variant_builder_add(&entry_builder,
+                              "{sv}",
+                              "priority",
+                              g_variant_new_int32(nm_ip_config_get_dns_priority(ip_config)));
+
+        g_variant_builder_add(
+            &entry_builder,
+            "{sv}",
+            "vpn",
+            g_variant_new_boolean(ip_data->ip_config_type == NM_DNS_IP_CONFIG_TYPE_VPN));
+
+        g_variant_builder_add(&builder, "a{sv}", &entry_builder);
+    }
+
+    priv->config_variant = g_variant_ref_sink(g_variant_builder_end(&builder));
+    _LOGT("current configuration: %s", (str = g_variant_print(priv->config_variant, TRUE)));
+
+    return priv->config_variant;
+}
+
+static void
+get_property(GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
+{
+    NMDnsManager *       self = NM_DNS_MANAGER(object);
+    NMDnsManagerPrivate *priv = NM_DNS_MANAGER_GET_PRIVATE(self);
+
+    switch (prop_id) {
+    case PROP_MODE:
+        g_value_set_string(value, priv->mode);
+        break;
+    case PROP_RC_MANAGER:
+        g_value_set_string(value, _rc_manager_to_string(priv->rc_manager));
+        break;
+    case PROP_CONFIGURATION:
+        g_value_set_variant(value, _get_config_variant(self));
+        break;
+    default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
+        break;
+    }
+}
+
+static void
+nm_dns_manager_init(NMDnsManager *self)
+{
+    NMDnsManagerPrivate *priv = NM_DNS_MANAGER_GET_PRIVATE(self);
+
+    _LOGT("creating...");
+
+    c_list_init(&priv->configs_lst_head);
+    c_list_init(&priv->ip_configs_lst_head);
+
+    priv->config = g_object_ref(nm_config_get());
+
+    G_STATIC_ASSERT_EXPR(G_STRUCT_OFFSET(NMDnsConfigData, ifindex) == 0);
+    priv->configs_dict = g_hash_table_new_full(nm_pint_hash,
+                                               nm_pint_equals,
+                                               (GDestroyNotify) _dns_config_data_free,
+                                               NULL);
+
+    /* Set the initial hash */
+    compute_hash(self, NULL, NM_DNS_MANAGER_GET_PRIVATE(self)->hash);
+
+    g_signal_connect(G_OBJECT(priv->config),
+                     NM_CONFIG_SIGNAL_CONFIG_CHANGED,
+                     G_CALLBACK(config_changed_cb),
+                     self);
+    init_resolv_conf_mode(self, TRUE);
+}
+
+static void
+dispose(GObject *object)
+{
+    NMDnsManager *       self = NM_DNS_MANAGER(object);
+    NMDnsManagerPrivate *priv = NM_DNS_MANAGER_GET_PRIVATE(self);
+    NMDnsConfigIPData *  ip_data, *ip_data_safe;
+
+    _LOGT("disposing");
+
+    if (!priv->is_stopped)
+        nm_dns_manager_stop(self);
+
+    if (priv->config)
+        g_signal_handlers_disconnect_by_func(priv->config, config_changed_cb, self);
+
+    g_clear_object(&priv->sd_resolve_plugin);
+    _clear_plugin(self);
+
+    priv->best_ip_config_4 = NULL;
+    priv->best_ip_config_6 = NULL;
+
+    c_list_for_each_entry_safe (ip_data, ip_data_safe, &priv->ip_configs_lst_head, ip_config_lst)
+        _dns_config_ip_data_free(ip_data);
+
+    nm_clear_pointer(&priv->configs_dict, g_hash_table_destroy);
+    nm_assert(c_list_is_empty(&priv->configs_lst_head));
+
+    nm_clear_g_source(&priv->plugin_ratelimit.timer);
+
+    g_clear_object(&priv->config);
+
+    G_OBJECT_CLASS(nm_dns_manager_parent_class)->dispose(object);
+
+    nm_clear_pointer(&priv->config_variant, g_variant_unref);
+}
+
+static void
+finalize(GObject *object)
+{
+    NMDnsManager *       self = NM_DNS_MANAGER(object);
+    NMDnsManagerPrivate *priv = NM_DNS_MANAGER_GET_PRIVATE(self);
+
+    g_free(priv->hostname);
+    g_free(priv->mode);
+
+    G_OBJECT_CLASS(nm_dns_manager_parent_class)->finalize(object);
+}
+
+static const NMDBusInterfaceInfoExtended interface_info_dns_manager = {
+    .parent = NM_DEFINE_GDBUS_INTERFACE_INFO_INIT(
+        NM_DBUS_INTERFACE_DNS_MANAGER,
+        .properties = NM_DEFINE_GDBUS_PROPERTY_INFOS(
+            NM_DEFINE_DBUS_PROPERTY_INFO_EXTENDED_READABLE_L("Mode", "s", NM_DNS_MANAGER_MODE),
+            NM_DEFINE_DBUS_PROPERTY_INFO_EXTENDED_READABLE_L("RcManager",
+                                                             "s",
+                                                             NM_DNS_MANAGER_RC_MANAGER),
+            NM_DEFINE_DBUS_PROPERTY_INFO_EXTENDED_READABLE_L("Configuration",
+                                                             "aa{sv}",
+                                                             NM_DNS_MANAGER_CONFIGURATION), ), ),
+};
+
+static void
+nm_dns_manager_class_init(NMDnsManagerClass *klass)
+{
+    GObjectClass *     object_class      = G_OBJECT_CLASS(klass);
+    NMDBusObjectClass *dbus_object_class = NM_DBUS_OBJECT_CLASS(klass);
+
+    object_class->dispose      = dispose;
+    object_class->finalize     = finalize;
+    object_class->get_property = get_property;
+
+    dbus_object_class->export_path     = NM_DBUS_EXPORT_PATH_STATIC(NM_DBUS_PATH "/DnsManager");
+    dbus_object_class->interface_infos = NM_DBUS_INTERFACE_INFOS(&interface_info_dns_manager);
+    dbus_object_class->export_on_construction = TRUE;
+
+    obj_properties[PROP_MODE] = g_param_spec_string(NM_DNS_MANAGER_MODE,
+                                                    "",
+                                                    "",
+                                                    NULL,
+                                                    G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);
+
+    obj_properties[PROP_RC_MANAGER] =
+        g_param_spec_string(NM_DNS_MANAGER_RC_MANAGER,
+                            "",
+                            "",
+                            NULL,
+                            G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);
+
+    obj_properties[PROP_CONFIGURATION] =
+        g_param_spec_variant(NM_DNS_MANAGER_CONFIGURATION,
+                             "",
+                             "",
+                             G_VARIANT_TYPE("aa{sv}"),
+                             NULL,
+                             G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);
+
+    g_object_class_install_properties(object_class, _PROPERTY_ENUMS_LAST, obj_properties);
+
+    signals[CONFIG_CHANGED] = g_signal_new(NM_DNS_MANAGER_CONFIG_CHANGED,
+                                           G_OBJECT_CLASS_TYPE(object_class),
+                                           G_SIGNAL_RUN_FIRST,
+                                           0,
+                                           NULL,
+                                           NULL,
+                                           g_cclosure_marshal_VOID__VOID,
+                                           G_TYPE_NONE,
+                                           0);
+}
diff --git a/src/core/dns/nm-dns-manager.h b/src/core/dns/nm-dns-manager.h
new file mode 100644
index 00000000..937ba62a
--- /dev/null
+++ b/src/core/dns/nm-dns-manager.h
@@ -0,0 +1,159 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2004 - 2005 Colin Walters <walters@redhat.com>
+ * Copyright (C) 2004 - 2013 Red Hat, Inc.
+ * Copyright (C) 2005 - 2008 Novell, Inc.
+ */
+
+#ifndef __NETWORKMANAGER_DNS_MANAGER_H__
+#define __NETWORKMANAGER_DNS_MANAGER_H__
+
+#include "nm-ip4-config.h"
+#include "nm-ip6-config.h"
+#include "nm-setting-connection.h"
+
+typedef enum {
+    NM_DNS_IP_CONFIG_TYPE_REMOVED = -1,
+
+    NM_DNS_IP_CONFIG_TYPE_DEFAULT = 0,
+    NM_DNS_IP_CONFIG_TYPE_BEST_DEVICE,
+    NM_DNS_IP_CONFIG_TYPE_VPN,
+} NMDnsIPConfigType;
+
+enum {
+    NM_DNS_PRIORITY_DEFAULT_NORMAL = 100,
+    NM_DNS_PRIORITY_DEFAULT_VPN    = 50,
+};
+
+/*****************************************************************************/
+
+struct _NMDnsConfigData;
+struct _NMDnsManager;
+
+typedef struct {
+    struct _NMDnsConfigData *data;
+    NMIPConfig *             ip_config;
+    CList                    data_lst;
+    CList                    ip_config_lst;
+    NMDnsIPConfigType        ip_config_type;
+    struct {
+        const char **search;
+        char **      reverse;
+
+        /* Whether "search" explicitly contains a default route "~"
+         * or "". It is redundant information, but for faster lookup. */
+        bool has_default_route_explicit : 1;
+
+        /* Whether an explicit "~" search domain should be added.
+         * For systemd-resolved, this configured an explicit wildcard
+         * search domain, and should be used for profiles with negative
+         * DNS priority.
+         *
+         * If "has_default_route_explicit", this is always TRUE and implied.
+         *
+         * With systemd-resolved, if TRUE we will set a "." search domain.
+         */
+        bool has_default_route_exclusive : 1;
+
+        /* Whether the device should be used for any domains "~".
+         *
+         * If "has_default_route_exclusive", this is always TRUE and implied.
+         *
+         * With systemd-resolved, this is the value for SetLinkDefaultRoute(). */
+        bool has_default_route : 1;
+    } domains;
+} NMDnsConfigIPData;
+
+typedef struct _NMDnsConfigData {
+    int                   ifindex;
+    struct _NMDnsManager *self;
+    CList                 data_lst_head;
+    CList                 configs_lst;
+} NMDnsConfigData;
+
+/*****************************************************************************/
+
+#define NM_TYPE_DNS_MANAGER (nm_dns_manager_get_type())
+#define NM_DNS_MANAGER(o)   (G_TYPE_CHECK_INSTANCE_CAST((o), NM_TYPE_DNS_MANAGER, NMDnsManager))
+#define NM_DNS_MANAGER_CLASS(k) \
+    (G_TYPE_CHECK_CLASS_CAST((k), NM_TYPE_DNS_MANAGER, NMDnsManagerClass))
+#define NM_IS_DNS_MANAGER(o)       (G_TYPE_CHECK_INSTANCE_TYPE((o), NM_TYPE_DNS_MANAGER))
+#define NM_IS_DNS_MANAGER_CLASS(k) (G_TYPE_CHECK_CLASS_TYPE((k), NM_TYPE_DNS_MANAGER))
+#define NM_DNS_MANAGER_GET_CLASS(o) \
+    (G_TYPE_INSTANCE_GET_CLASS((o), NM_TYPE_DNS_MANAGER, NMDnsManagerClass))
+
+/* properties */
+#define NM_DNS_MANAGER_MODE          "mode"
+#define NM_DNS_MANAGER_RC_MANAGER    "rc-manager"
+#define NM_DNS_MANAGER_CONFIGURATION "configuration"
+
+/* internal signals */
+#define NM_DNS_MANAGER_CONFIG_CHANGED "config-changed"
+
+typedef struct _NMDnsManager      NMDnsManager;
+typedef struct _NMDnsManagerClass NMDnsManagerClass;
+
+GType nm_dns_manager_get_type(void);
+
+NMDnsManager *nm_dns_manager_get(void);
+
+/* Allow changes to be batched together */
+void nm_dns_manager_begin_updates(NMDnsManager *self, const char *func);
+void nm_dns_manager_end_updates(NMDnsManager *self, const char *func);
+
+gboolean nm_dns_manager_set_ip_config(NMDnsManager *    self,
+                                      NMIPConfig *      ip_config,
+                                      NMDnsIPConfigType ip_config_type);
+
+void nm_dns_manager_set_initial_hostname(NMDnsManager *self, const char *hostname);
+void nm_dns_manager_set_hostname(NMDnsManager *self, const char *hostname, gboolean skip_update);
+
+/**
+ * NMDnsManagerResolvConfManager
+ * @NM_DNS_MANAGER_RESOLV_CONF_MAN_UNKNOWN: unspecified rc-manager.
+ * @NM_DNS_MANAGER_RESOLV_CONF_MAN_UNMANAGED: do not touch /etc/resolv.conf
+ *   (but still write the internal copy -- unless it is symlinked by
+ *   /etc/resolv.conf)
+ * @NM_DNS_MANAGER_RESOLV_CONF_MAN_AUTO: if /etc/resolv.conf is marked
+ *   as an immutable file, use "unmanaged" and don't touch /etc/resolv.conf.
+ *   Otherwise, if "systemd-resolved" is enabled (or detected), configure systemd-resolved via D-Bus
+ *   and don't touch /etc/resolv.conf.
+ *   Otherwise, if "resolvconf" application is found, use it.
+ *   As last resort, fallback to "symlink" which writes to /etc/resolv.conf
+ *   if (and only if) the file is missing or not a symlink.
+ * @NM_DNS_MANAGER_RESOLV_CONF_MAN_IMMUTABLE: similar to "unmanaged",
+ *   but indicates that resolv.conf cannot be modified.
+ * @NM_DNS_MANAGER_RESOLV_CONF_MAN_SYMLINK: NM writes /etc/resolv.conf
+ *   if the file is missing or not a symlink. An existing symlink is
+ *   left untouched.
+ * @NM_DNS_MANAGER_RESOLV_CONF_MAN_FILE: Write to /etc/resolv.conf directly.
+ *   If it is a file, write it as file, otherwise follow symlinks.
+ * @NM_DNS_MANAGER_RESOLV_CONF_MAN_RESOLVCONF: NM is managing resolv.conf
+     through resolvconf
+ * @NM_DNS_MANAGER_RESOLV_CONF_MAN_NETCONFIG: NM is managing resolv.conf
+     through netconfig
+ *
+ * NMDnsManager's management of resolv.conf
+ */
+typedef enum {
+    NM_DNS_MANAGER_RESOLV_CONF_MAN_UNKNOWN,
+    NM_DNS_MANAGER_RESOLV_CONF_MAN_AUTO,
+    NM_DNS_MANAGER_RESOLV_CONF_MAN_UNMANAGED,
+    NM_DNS_MANAGER_RESOLV_CONF_MAN_IMMUTABLE,
+    NM_DNS_MANAGER_RESOLV_CONF_MAN_SYMLINK,
+    NM_DNS_MANAGER_RESOLV_CONF_MAN_FILE,
+    NM_DNS_MANAGER_RESOLV_CONF_MAN_RESOLVCONF,
+    NM_DNS_MANAGER_RESOLV_CONF_MAN_NETCONFIG,
+} NMDnsManagerResolvConfManager;
+
+void nm_dns_manager_stop(NMDnsManager *self);
+
+gboolean nm_dns_manager_has_systemd_resolved(NMDnsManager *self);
+
+/*****************************************************************************/
+
+char *nmtst_dns_create_resolv_conf(const char *const *searches,
+                                   const char *const *nameservers,
+                                   const char *const *options);
+
+#endif /* __NETWORKMANAGER_DNS_MANAGER_H__ */
diff --git a/src/core/dns/nm-dns-plugin.c b/src/core/dns/nm-dns-plugin.c
new file mode 100644
index 00000000..74d4eb2b
--- /dev/null
+++ b/src/core/dns/nm-dns-plugin.c
@@ -0,0 +1,113 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2010 - 2012 Red Hat, Inc.
+ */
+
+#include "src/core/nm-default-daemon.h"
+
+#include "nm-dns-plugin.h"
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include "nm-core-internal.h"
+#include "NetworkManagerUtils.h"
+
+/*****************************************************************************/
+
+typedef struct _NMDnsPluginPrivate {
+    GPid  pid;
+    guint watch_id;
+    char *progname;
+    char *pidfile;
+} NMDnsPluginPrivate;
+
+G_DEFINE_ABSTRACT_TYPE(NMDnsPlugin, nm_dns_plugin, G_TYPE_OBJECT)
+
+#define NM_DNS_PLUGIN_GET_PRIVATE(self) _NM_GET_PRIVATE_PTR(self, NMDnsPlugin, NM_IS_DNS_PLUGIN)
+
+/*****************************************************************************/
+
+#define _NMLOG_PREFIX_NAME "dns-plugin"
+#define _NMLOG_DOMAIN      LOGD_DNS
+#define _NMLOG(level, ...)                                                    \
+    G_STMT_START                                                              \
+    {                                                                         \
+        const NMLogLevel __level = (level);                                   \
+                                                                              \
+        if (nm_logging_enabled(__level, _NMLOG_DOMAIN)) {                     \
+            char                     __prefix[20];                            \
+            const NMDnsPlugin *const __self = (self);                         \
+                                                                              \
+            _nm_log(__level,                                                  \
+                    _NMLOG_DOMAIN,                                            \
+                    0,                                                        \
+                    NULL,                                                     \
+                    NULL,                                                     \
+                    "%s%s: " _NM_UTILS_MACRO_FIRST(__VA_ARGS__),              \
+                    _NMLOG_PREFIX_NAME,                                       \
+                    (!__self ? "" : nm_sprintf_buf(__prefix, "[%p]", __self)) \
+                        _NM_UTILS_MACRO_REST(__VA_ARGS__));                   \
+        }                                                                     \
+    }                                                                         \
+    G_STMT_END
+
+/*****************************************************************************/
+
+gboolean
+nm_dns_plugin_update(NMDnsPlugin *            self,
+                     const NMGlobalDnsConfig *global_config,
+                     const CList *            ip_config_lst_head,
+                     const char *             hostname,
+                     GError **                error)
+{
+    g_return_val_if_fail(NM_DNS_PLUGIN_GET_CLASS(self)->update != NULL, FALSE);
+
+    return NM_DNS_PLUGIN_GET_CLASS(self)->update(self,
+                                                 global_config,
+                                                 ip_config_lst_head,
+                                                 hostname,
+                                                 error);
+}
+
+gboolean
+nm_dns_plugin_is_caching(NMDnsPlugin *self)
+{
+    return NM_DNS_PLUGIN_GET_CLASS(self)->is_caching;
+}
+
+const char *
+nm_dns_plugin_get_name(NMDnsPlugin *self)
+{
+    NMDnsPluginClass *klass;
+
+    g_return_val_if_fail(NM_IS_DNS_PLUGIN(self), NULL);
+
+    klass = NM_DNS_PLUGIN_GET_CLASS(self);
+    nm_assert(klass->plugin_name);
+    return klass->plugin_name;
+}
+
+void
+nm_dns_plugin_stop(NMDnsPlugin *self)
+{
+    NMDnsPluginClass *klass;
+
+    g_return_if_fail(NM_IS_DNS_PLUGIN(self));
+
+    klass = NM_DNS_PLUGIN_GET_CLASS(self);
+    if (klass->stop)
+        klass->stop(self);
+}
+
+/*****************************************************************************/
+
+static void
+nm_dns_plugin_init(NMDnsPlugin *self)
+{}
+
+static void
+nm_dns_plugin_class_init(NMDnsPluginClass *plugin_class)
+{}
diff --git a/src/core/dns/nm-dns-plugin.h b/src/core/dns/nm-dns-plugin.h
new file mode 100644
index 00000000..644d01e5
--- /dev/null
+++ b/src/core/dns/nm-dns-plugin.h
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2010 Red Hat, Inc.
+ */
+
+#ifndef __NM_DNS_PLUGIN_H__
+#define __NM_DNS_PLUGIN_H__
+
+#include "nm-dns-manager.h"
+#include "nm-config-data.h"
+
+#define NM_TYPE_DNS_PLUGIN (nm_dns_plugin_get_type())
+#define NM_DNS_PLUGIN(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), NM_TYPE_DNS_PLUGIN, NMDnsPlugin))
+#define NM_DNS_PLUGIN_CLASS(klass) \
+    (G_TYPE_CHECK_CLASS_CAST((klass), NM_TYPE_DNS_PLUGIN, NMDnsPluginClass))
+#define NM_IS_DNS_PLUGIN(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj), NM_TYPE_DNS_PLUGIN))
+#define NM_IS_DNS_PLUGIN_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), NM_TYPE_DNS_PLUGIN))
+#define NM_DNS_PLUGIN_GET_CLASS(obj) \
+    (G_TYPE_INSTANCE_GET_CLASS((obj), NM_TYPE_DNS_PLUGIN, NMDnsPluginClass))
+
+typedef struct {
+    GObject parent;
+} NMDnsPlugin;
+
+typedef struct {
+    GObjectClass parent;
+
+    /* Called when DNS information is changed.  'configs' is an array
+     * of pointers to NMDnsConfigIPData sorted by priority.
+     * 'global_config' is the optional global DNS
+     * configuration.
+     */
+    gboolean (*update)(NMDnsPlugin *            self,
+                       const NMGlobalDnsConfig *global_config,
+                       const CList *            ip_config_lst_head,
+                       const char *             hostname,
+                       GError **                error);
+
+    void (*stop)(NMDnsPlugin *self);
+
+    const char *plugin_name;
+
+    /* Types should set to TRUE if they start a local caching nameserver
+     * that listens on localhost and would block any other local caching
+     * nameserver from operating.
+     */
+    bool is_caching : 1;
+
+} NMDnsPluginClass;
+
+GType nm_dns_plugin_get_type(void);
+
+gboolean nm_dns_plugin_is_caching(NMDnsPlugin *self);
+
+const char *nm_dns_plugin_get_name(NMDnsPlugin *self);
+
+gboolean nm_dns_plugin_update(NMDnsPlugin *            self,
+                              const NMGlobalDnsConfig *global_config,
+                              const CList *            ip_config_lst_head,
+                              const char *             hostname,
+                              GError **                error);
+
+void nm_dns_plugin_stop(NMDnsPlugin *self);
+
+#endif /* __NM_DNS_PLUGIN_H__ */
diff --git a/src/core/dns/nm-dns-systemd-resolved.c b/src/core/dns/nm-dns-systemd-resolved.c
new file mode 100644
index 00000000..f6e116f3
--- /dev/null
+++ b/src/core/dns/nm-dns-systemd-resolved.c
@@ -0,0 +1,640 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2010 Dan Williams <dcbw@redhat.com>
+ * Copyright (C) 2016 Sjoerd Simons <sjoerd@luon.net>
+ */
+
+#include "src/core/nm-default-daemon.h"
+
+#include "nm-dns-systemd-resolved.h"
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <arpa/inet.h>
+#include <sys/stat.h>
+#include <linux/if.h>
+
+#include "nm-glib-aux/nm-c-list.h"
+#include "nm-glib-aux/nm-dbus-aux.h"
+#include "nm-core-internal.h"
+#include "platform/nm-platform.h"
+#include "nm-utils.h"
+#include "nm-ip4-config.h"
+#include "nm-ip6-config.h"
+#include "nm-dbus-manager.h"
+#include "nm-manager.h"
+#include "nm-setting-connection.h"
+#include "devices/nm-device.h"
+#include "NetworkManagerUtils.h"
+#include "nm-std-aux/nm-dbus-compat.h"
+
+#define SYSTEMD_RESOLVED_DBUS_SERVICE  "org.freedesktop.resolve1"
+#define SYSTEMD_RESOLVED_MANAGER_IFACE "org.freedesktop.resolve1.Manager"
+#define SYSTEMD_RESOLVED_DBUS_PATH     "/org/freedesktop/resolve1"
+
+/* define a variable, so that we can compare the operation with pointer equality. */
+static const char *const DBUS_OP_SET_LINK_DEFAULT_ROUTE = "SetLinkDefaultRoute";
+
+/*****************************************************************************/
+
+typedef struct {
+    int   ifindex;
+    CList configs_lst_head;
+} InterfaceConfig;
+
+typedef struct {
+    CList                 request_queue_lst;
+    const char *          operation;
+    GVariant *            argument;
+    NMDnsSystemdResolved *self;
+    int                   ifindex;
+} RequestItem;
+
+/*****************************************************************************/
+
+typedef struct {
+    GDBusConnection *dbus_connection;
+    GHashTable *     dirty_interfaces;
+    GCancellable *   cancellable;
+    CList            request_queue_lst_head;
+    guint            name_owner_changed_id;
+    bool             send_updates_warn_ratelimited : 1;
+    bool             try_start_blocked : 1;
+    bool             dbus_has_owner : 1;
+    bool             dbus_initied : 1;
+    bool             request_queue_to_send : 1;
+    NMTernary        has_link_default_route : 3;
+} NMDnsSystemdResolvedPrivate;
+
+struct _NMDnsSystemdResolved {
+    NMDnsPlugin                 parent;
+    NMDnsSystemdResolvedPrivate _priv;
+};
+
+struct _NMDnsSystemdResolvedClass {
+    NMDnsPluginClass parent;
+};
+
+G_DEFINE_TYPE(NMDnsSystemdResolved, nm_dns_systemd_resolved, NM_TYPE_DNS_PLUGIN)
+
+#define NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE(self) \
+    _NM_GET_PRIVATE(self, NMDnsSystemdResolved, NM_IS_DNS_SYSTEMD_RESOLVED)
+
+/*****************************************************************************/
+
+#define _NMLOG_DOMAIN LOGD_DNS
+#define _NMLOG(level, ...) \
+    __NMLOG_DEFAULT_WITH_ADDR(level, _NMLOG_DOMAIN, "dns-sd-resolved", __VA_ARGS__)
+
+/*****************************************************************************/
+
+static void
+_request_item_free(RequestItem *request_item)
+{
+    c_list_unlink_stale(&request_item->request_queue_lst);
+    g_variant_unref(request_item->argument);
+    nm_g_slice_free(request_item);
+}
+
+static void
+_request_item_append(NMDnsSystemdResolved *self,
+                     const char *          operation,
+                     int                   ifindex,
+                     GVariant *            argument)
+{
+    NMDnsSystemdResolvedPrivate *priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE(self);
+    RequestItem *                request_item;
+
+    request_item  = g_slice_new(RequestItem);
+    *request_item = (RequestItem){
+        .operation = operation,
+        .argument  = g_variant_ref_sink(argument),
+        .self      = self,
+        .ifindex   = ifindex,
+    };
+    c_list_link_tail(&priv->request_queue_lst_head, &request_item->request_queue_lst);
+}
+
+/*****************************************************************************/
+
+static void
+_interface_config_free(InterfaceConfig *config)
+{
+    nm_c_list_elem_free_all(&config->configs_lst_head, NULL);
+    g_slice_free(InterfaceConfig, config);
+}
+
+static void
+call_done(GObject *source, GAsyncResult *r, gpointer user_data)
+{
+    gs_unref_variant GVariant *v       = NULL;
+    gs_free_error GError *       error = NULL;
+    NMDnsSystemdResolved *       self;
+    NMDnsSystemdResolvedPrivate *priv;
+    RequestItem *                request_item;
+    NMLogLevel                   log_level;
+
+    v = g_dbus_connection_call_finish(G_DBUS_CONNECTION(source), r, &error);
+    if (nm_utils_error_is_cancelled(error))
+        return;
+
+    request_item = user_data;
+    self         = request_item->self;
+    priv         = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE(self);
+
+    if (v) {
+        if (request_item->operation == DBUS_OP_SET_LINK_DEFAULT_ROUTE
+            && priv->has_link_default_route == NM_TERNARY_DEFAULT) {
+            priv->has_link_default_route = NM_TERNARY_TRUE;
+            _LOGD("systemd-resolved support for SetLinkDefaultRoute(): API supported");
+        }
+        priv->send_updates_warn_ratelimited = FALSE;
+        return;
+    }
+
+    if (request_item->operation == DBUS_OP_SET_LINK_DEFAULT_ROUTE
+        && nm_g_error_matches(error, G_DBUS_ERROR, G_DBUS_ERROR_UNKNOWN_METHOD)) {
+        if (priv->has_link_default_route == NM_TERNARY_DEFAULT) {
+            priv->has_link_default_route = NM_TERNARY_FALSE;
+            _LOGD("systemd-resolved support for SetLinkDefaultRoute(): API not supported");
+        }
+        return;
+    }
+
+    log_level = LOGL_DEBUG;
+    if (!priv->send_updates_warn_ratelimited) {
+        priv->send_updates_warn_ratelimited = TRUE;
+        log_level                           = LOGL_WARN;
+    }
+    _NMLOG(log_level,
+           "send-updates %s@%d failed: %s",
+           request_item->operation,
+           request_item->ifindex,
+           error->message);
+}
+
+static gboolean
+update_add_ip_config(NMDnsSystemdResolved *self,
+                     GVariantBuilder *     dns,
+                     GVariantBuilder *     domains,
+                     NMDnsConfigIPData *   data)
+{
+    int         addr_family;
+    gsize       addr_size;
+    guint       i, n;
+    gboolean    is_routing;
+    const char *domain;
+    gboolean    has_config = FALSE;
+
+    addr_family = nm_ip_config_get_addr_family(data->ip_config);
+    addr_size   = nm_utils_addr_family_to_size(addr_family);
+
+    if ((!data->domains.search || !data->domains.search[0])
+        && !data->domains.has_default_route_exclusive && !data->domains.has_default_route)
+        return FALSE;
+
+    n = nm_ip_config_get_num_nameservers(data->ip_config);
+    for (i = 0; i < n; i++) {
+        g_variant_builder_open(dns, G_VARIANT_TYPE("(iay)"));
+        g_variant_builder_add(dns, "i", addr_family);
+        g_variant_builder_add_value(
+            dns,
+            g_variant_new_fixed_array(G_VARIANT_TYPE_BYTE,
+                                      nm_ip_config_get_nameserver(data->ip_config, i),
+                                      addr_size,
+                                      1));
+        g_variant_builder_close(dns);
+        has_config = TRUE;
+    }
+
+    if (!data->domains.has_default_route_explicit && data->domains.has_default_route_exclusive) {
+        g_variant_builder_add(domains, "(sb)", ".", TRUE);
+        has_config = TRUE;
+    }
+    if (data->domains.search) {
+        for (i = 0; data->domains.search[i]; i++) {
+            domain = nm_utils_parse_dns_domain(data->domains.search[i], &is_routing);
+            g_variant_builder_add(domains, "(sb)", domain[0] ? domain : ".", is_routing);
+            has_config = TRUE;
+        }
+    }
+
+    return has_config;
+}
+
+static void
+free_pending_updates(NMDnsSystemdResolved *self)
+{
+    NMDnsSystemdResolvedPrivate *priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE(self);
+    RequestItem *                request_item;
+
+    while ((request_item =
+                c_list_first_entry(&priv->request_queue_lst_head, RequestItem, request_queue_lst)))
+        _request_item_free(request_item);
+}
+
+static gboolean
+prepare_one_interface(NMDnsSystemdResolved *self, InterfaceConfig *ic)
+{
+    GVariantBuilder          dns;
+    GVariantBuilder          domains;
+    NMCListElem *            elem;
+    NMSettingConnectionMdns  mdns     = NM_SETTING_CONNECTION_MDNS_DEFAULT;
+    NMSettingConnectionLlmnr llmnr    = NM_SETTING_CONNECTION_LLMNR_DEFAULT;
+    const char *             mdns_arg = NULL, *llmnr_arg = NULL;
+    gboolean                 has_config        = FALSE;
+    gboolean                 has_default_route = FALSE;
+
+    g_variant_builder_init(&dns, G_VARIANT_TYPE("(ia(iay))"));
+    g_variant_builder_add(&dns, "i", ic->ifindex);
+    g_variant_builder_open(&dns, G_VARIANT_TYPE("a(iay)"));
+
+    g_variant_builder_init(&domains, G_VARIANT_TYPE("(ia(sb))"));
+    g_variant_builder_add(&domains, "i", ic->ifindex);
+    g_variant_builder_open(&domains, G_VARIANT_TYPE("a(sb)"));
+
+    c_list_for_each_entry (elem, &ic->configs_lst_head, lst) {
+        NMDnsConfigIPData *data      = elem->data;
+        NMIPConfig *       ip_config = data->ip_config;
+
+        has_config |= update_add_ip_config(self, &dns, &domains, data);
+
+        if (data->domains.has_default_route)
+            has_default_route = TRUE;
+
+        if (NM_IS_IP4_CONFIG(ip_config)) {
+            mdns  = NM_MAX(mdns, nm_ip4_config_mdns_get(NM_IP4_CONFIG(ip_config)));
+            llmnr = NM_MAX(llmnr, nm_ip4_config_llmnr_get(NM_IP4_CONFIG(ip_config)));
+        }
+    }
+
+    g_variant_builder_close(&dns);
+    g_variant_builder_close(&domains);
+
+    switch (mdns) {
+    case NM_SETTING_CONNECTION_MDNS_NO:
+        mdns_arg = "no";
+        break;
+    case NM_SETTING_CONNECTION_MDNS_RESOLVE:
+        mdns_arg = "resolve";
+        break;
+    case NM_SETTING_CONNECTION_MDNS_YES:
+        mdns_arg = "yes";
+        break;
+    case NM_SETTING_CONNECTION_MDNS_DEFAULT:
+        mdns_arg = "";
+        break;
+    }
+    nm_assert(mdns_arg);
+
+    switch (llmnr) {
+    case NM_SETTING_CONNECTION_LLMNR_NO:
+        llmnr_arg = "no";
+        break;
+    case NM_SETTING_CONNECTION_LLMNR_RESOLVE:
+        llmnr_arg = "resolve";
+        break;
+    case NM_SETTING_CONNECTION_LLMNR_YES:
+        llmnr_arg = "yes";
+        break;
+    case NM_SETTING_CONNECTION_LLMNR_DEFAULT:
+        llmnr_arg = "";
+        break;
+    }
+    nm_assert(llmnr_arg);
+
+    if (!nm_str_is_empty(mdns_arg) || !nm_str_is_empty(llmnr_arg))
+        has_config = TRUE;
+
+    _request_item_append(self, "SetLinkDomains", ic->ifindex, g_variant_builder_end(&domains));
+    _request_item_append(self,
+                         DBUS_OP_SET_LINK_DEFAULT_ROUTE,
+                         ic->ifindex,
+                         g_variant_new("(ib)", ic->ifindex, has_default_route));
+    _request_item_append(self,
+                         "SetLinkMulticastDNS",
+                         ic->ifindex,
+                         g_variant_new("(is)", ic->ifindex, mdns_arg ?: ""));
+    _request_item_append(self,
+                         "SetLinkLLMNR",
+                         ic->ifindex,
+                         g_variant_new("(is)", ic->ifindex, llmnr_arg ?: ""));
+    _request_item_append(self, "SetLinkDNS", ic->ifindex, g_variant_builder_end(&dns));
+
+    return has_config;
+}
+
+static void
+send_updates(NMDnsSystemdResolved *self)
+{
+    NMDnsSystemdResolvedPrivate *priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE(self);
+    RequestItem *                request_item;
+
+    if (!priv->request_queue_to_send) {
+        /* nothing to do. */
+        return;
+    }
+
+    if (!priv->dbus_initied) {
+        _LOGT("send-updates: D-Bus connection not ready");
+        return;
+    }
+
+    if (!priv->dbus_has_owner) {
+        if (priv->try_start_blocked) {
+            /* we have no name owner and we already tried poking the service to
+             * autostart. */
+            _LOGT("send-updates: no name owner");
+            return;
+        }
+
+        _LOGT("send-updates: no name owner. Try start service...");
+        priv->try_start_blocked = TRUE;
+
+        nm_dbus_connection_call_start_service_by_name(priv->dbus_connection,
+                                                      SYSTEMD_RESOLVED_DBUS_SERVICE,
+                                                      -1,
+                                                      NULL,
+                                                      NULL,
+                                                      NULL);
+        return;
+    }
+
+    nm_clear_g_cancellable(&priv->cancellable);
+
+    if (c_list_is_empty(&priv->request_queue_lst_head)) {
+        _LOGT("send-updates: no requests to send");
+        priv->request_queue_to_send = FALSE;
+        return;
+    }
+
+    _LOGT("send-updates: start %lu requests", c_list_length(&priv->request_queue_lst_head));
+
+    priv->cancellable = g_cancellable_new();
+
+    priv->request_queue_to_send = FALSE;
+
+    c_list_for_each_entry (request_item, &priv->request_queue_lst_head, request_queue_lst) {
+        if (request_item->operation == DBUS_OP_SET_LINK_DEFAULT_ROUTE
+            && priv->has_link_default_route == NM_TERNARY_FALSE) {
+            /* The "SetLinkDefaultRoute" API is only supported since v240.
+             * We detected that it is not supported, and skip the call. There
+             * is no special workaround, because in this case we rely on systemd-resolved
+             * to do the right thing automatically. */
+            continue;
+        }
+
+        /* Above we explicitly call "StartServiceByName" trying to avoid D-Bus activating systmd-resolved
+         * multiple times. There is still a race, were we might hit this line although actually
+         * the service just quit this very moment. In that case, we would try to D-Bus activate the
+         * service multiple times during each call (something we wanted to avoid).
+         *
+         * But this is hard to avoid, because we'd have to check the error failure to detect the reason
+         * and retry. The race is not critical, because at worst it results in logging a warning
+         * about failure to start systemd.resolved. */
+        g_dbus_connection_call(priv->dbus_connection,
+                               SYSTEMD_RESOLVED_DBUS_SERVICE,
+                               SYSTEMD_RESOLVED_DBUS_PATH,
+                               SYSTEMD_RESOLVED_MANAGER_IFACE,
+                               request_item->operation,
+                               request_item->argument,
+                               NULL,
+                               G_DBUS_CALL_FLAGS_NONE,
+                               -1,
+                               priv->cancellable,
+                               call_done,
+                               request_item);
+    }
+}
+
+static gboolean
+update(NMDnsPlugin *            plugin,
+       const NMGlobalDnsConfig *global_config,
+       const CList *            ip_config_lst_head,
+       const char *             hostname,
+       GError **                error)
+{
+    NMDnsSystemdResolved *       self         = NM_DNS_SYSTEMD_RESOLVED(plugin);
+    NMDnsSystemdResolvedPrivate *priv         = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE(self);
+    gs_unref_hashtable GHashTable *interfaces = NULL;
+    gs_free gpointer * interfaces_keys        = NULL;
+    guint              interfaces_len;
+    int                ifindex;
+    gpointer           pointer;
+    NMDnsConfigIPData *ip_data;
+    GHashTableIter     iter;
+    guint              i;
+
+    interfaces =
+        g_hash_table_new_full(nm_direct_hash, NULL, NULL, (GDestroyNotify) _interface_config_free);
+
+    c_list_for_each_entry (ip_data, ip_config_lst_head, ip_config_lst) {
+        InterfaceConfig *ic = NULL;
+
+        ifindex = ip_data->data->ifindex;
+        nm_assert(ifindex == nm_ip_config_get_ifindex(ip_data->ip_config));
+
+        ic = g_hash_table_lookup(interfaces, GINT_TO_POINTER(ifindex));
+        if (!ic) {
+            ic          = g_slice_new(InterfaceConfig);
+            ic->ifindex = ifindex;
+            c_list_init(&ic->configs_lst_head);
+            g_hash_table_insert(interfaces, GINT_TO_POINTER(ifindex), ic);
+        }
+
+        c_list_link_tail(&ic->configs_lst_head, &nm_c_list_elem_new_stale(ip_data)->lst);
+    }
+
+    free_pending_updates(self);
+
+    interfaces_keys =
+        nm_utils_hash_keys_to_array(interfaces, nm_cmp_int2ptr_p_with_data, NULL, &interfaces_len);
+    for (i = 0; i < interfaces_len; i++) {
+        InterfaceConfig *ic = g_hash_table_lookup(interfaces, GINT_TO_POINTER(interfaces_keys[i]));
+
+        if (prepare_one_interface(self, ic))
+            g_hash_table_add(priv->dirty_interfaces, GINT_TO_POINTER(ic->ifindex));
+        else
+            g_hash_table_remove(priv->dirty_interfaces, GINT_TO_POINTER(ic->ifindex));
+    }
+
+    /* If we previously configured an ifindex with non-empty values in
+     * resolved, and the current update doesn't contain that interface,
+     * reset the resolved configuration for that ifindex. */
+    g_hash_table_iter_init(&iter, priv->dirty_interfaces);
+    while (g_hash_table_iter_next(&iter, (gpointer *) &pointer, NULL)) {
+        ifindex = GPOINTER_TO_INT(pointer);
+        if (!g_hash_table_contains(interfaces, GINT_TO_POINTER(ifindex))) {
+            InterfaceConfig ic;
+
+            _LOGT("clear previously configured ifindex %d", ifindex);
+            ic = (InterfaceConfig){
+                .ifindex          = ifindex,
+                .configs_lst_head = C_LIST_INIT(ic.configs_lst_head),
+            };
+            prepare_one_interface(self, &ic);
+            g_hash_table_iter_remove(&iter);
+        }
+    }
+
+    priv->request_queue_to_send = TRUE;
+    send_updates(self);
+    return TRUE;
+}
+
+/*****************************************************************************/
+
+static void
+name_owner_changed(NMDnsSystemdResolved *self, const char *owner)
+{
+    NMDnsSystemdResolvedPrivate *priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE(self);
+
+    owner = nm_str_not_empty(owner);
+
+    if (!owner)
+        _LOGT("D-Bus name for systemd-resolved has no owner");
+    else
+        _LOGT("D-Bus name for systemd-resolved has owner %s", owner);
+
+    priv->dbus_has_owner = !!owner;
+    if (owner) {
+        priv->try_start_blocked     = FALSE;
+        priv->request_queue_to_send = TRUE;
+    } else
+        priv->has_link_default_route = NM_TERNARY_DEFAULT;
+
+    send_updates(self);
+}
+
+static void
+name_owner_changed_cb(GDBusConnection *connection,
+                      const char *     sender_name,
+                      const char *     object_path,
+                      const char *     interface_name,
+                      const char *     signal_name,
+                      GVariant *       parameters,
+                      gpointer         user_data)
+{
+    NMDnsSystemdResolved *       self = user_data;
+    NMDnsSystemdResolvedPrivate *priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE(self);
+    const char *                 new_owner;
+
+    if (!g_variant_is_of_type(parameters, G_VARIANT_TYPE("(sss)")))
+        return;
+
+    g_variant_get(parameters, "(&s&s&s)", NULL, NULL, &new_owner);
+
+    if (!priv->dbus_initied) {
+        /* There was a race and we got a NameOwnerChanged signal before GetNameOwner
+         * returns. */
+        priv->dbus_initied = TRUE;
+        nm_clear_g_cancellable(&priv->cancellable);
+    }
+
+    name_owner_changed(user_data, new_owner);
+}
+
+static void
+get_name_owner_cb(const char *name_owner, GError *error, gpointer user_data)
+{
+    NMDnsSystemdResolved *       self;
+    NMDnsSystemdResolvedPrivate *priv;
+
+    if (!name_owner && g_error_matches(error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+        return;
+
+    self = user_data;
+    priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE(self);
+
+    g_clear_object(&priv->cancellable);
+
+    priv->dbus_initied = TRUE;
+
+    name_owner_changed(self, name_owner);
+}
+
+/*****************************************************************************/
+
+gboolean
+nm_dns_systemd_resolved_is_running(NMDnsSystemdResolved *self)
+{
+    NMDnsSystemdResolvedPrivate *priv;
+
+    g_return_val_if_fail(NM_IS_DNS_SYSTEMD_RESOLVED(self), FALSE);
+
+    priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE(self);
+
+    return priv->dbus_initied && (priv->dbus_has_owner || !priv->try_start_blocked);
+}
+
+/*****************************************************************************/
+
+static void
+nm_dns_systemd_resolved_init(NMDnsSystemdResolved *self)
+{
+    NMDnsSystemdResolvedPrivate *priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE(self);
+
+    priv->has_link_default_route = NM_TERNARY_DEFAULT;
+
+    c_list_init(&priv->request_queue_lst_head);
+    priv->dirty_interfaces = g_hash_table_new(nm_direct_hash, NULL);
+
+    priv->dbus_connection = nm_g_object_ref(NM_MAIN_DBUS_CONNECTION_GET);
+    if (!priv->dbus_connection) {
+        _LOGD("no D-Bus connection");
+        return;
+    }
+
+    priv->name_owner_changed_id =
+        nm_dbus_connection_signal_subscribe_name_owner_changed(priv->dbus_connection,
+                                                               SYSTEMD_RESOLVED_DBUS_SERVICE,
+                                                               name_owner_changed_cb,
+                                                               self,
+                                                               NULL);
+    priv->cancellable = g_cancellable_new();
+    nm_dbus_connection_call_get_name_owner(priv->dbus_connection,
+                                           SYSTEMD_RESOLVED_DBUS_SERVICE,
+                                           -1,
+                                           priv->cancellable,
+                                           get_name_owner_cb,
+                                           self);
+}
+
+NMDnsPlugin *
+nm_dns_systemd_resolved_new(void)
+{
+    return g_object_new(NM_TYPE_DNS_SYSTEMD_RESOLVED, NULL);
+}
+
+static void
+dispose(GObject *object)
+{
+    NMDnsSystemdResolved *       self = NM_DNS_SYSTEMD_RESOLVED(object);
+    NMDnsSystemdResolvedPrivate *priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE(self);
+
+    free_pending_updates(self);
+
+    nm_clear_g_dbus_connection_signal(priv->dbus_connection, &priv->name_owner_changed_id);
+
+    nm_clear_g_cancellable(&priv->cancellable);
+
+    g_clear_object(&priv->dbus_connection);
+    nm_clear_pointer(&priv->dirty_interfaces, g_hash_table_unref);
+
+    G_OBJECT_CLASS(nm_dns_systemd_resolved_parent_class)->dispose(object);
+}
+
+static void
+nm_dns_systemd_resolved_class_init(NMDnsSystemdResolvedClass *dns_class)
+{
+    NMDnsPluginClass *plugin_class = NM_DNS_PLUGIN_CLASS(dns_class);
+    GObjectClass *    object_class = G_OBJECT_CLASS(dns_class);
+
+    object_class->dispose = dispose;
+
+    plugin_class->plugin_name = "systemd-resolved";
+    plugin_class->is_caching  = TRUE;
+    plugin_class->update      = update;
+}
diff --git a/src/core/dns/nm-dns-systemd-resolved.h b/src/core/dns/nm-dns-systemd-resolved.h
new file mode 100644
index 00000000..4ab04ab4
--- /dev/null
+++ b/src/core/dns/nm-dns-systemd-resolved.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2010 Red Hat, Inc.
+ * Copyright (C) 2016 Sjoerd Simons <sjoerd@luon.net>
+ */
+
+#ifndef __NETWORKMANAGER_DNS_SYSTEMD_RESOLVED_H__
+#define __NETWORKMANAGER_DNS_SYSTEMD_RESOLVED_H__
+
+#include "nm-dns-plugin.h"
+
+#define NM_TYPE_DNS_SYSTEMD_RESOLVED (nm_dns_systemd_resolved_get_type())
+#define NM_DNS_SYSTEMD_RESOLVED(obj) \
+    (G_TYPE_CHECK_INSTANCE_CAST((obj), NM_TYPE_DNS_SYSTEMD_RESOLVED, NMDnsSystemdResolved))
+#define NM_DNS_SYSTEMD_RESOLVED_CLASS(klass) \
+    (G_TYPE_CHECK_CLASS_CAST((klass), NM_TYPE_DNS_SYSTEMD_RESOLVED, NMDnsSystemdResolvedClass))
+#define NM_IS_DNS_SYSTEMD_RESOLVED(obj) \
+    (G_TYPE_CHECK_INSTANCE_TYPE((obj), NM_TYPE_DNS_SYSTEMD_RESOLVED))
+#define NM_IS_DNS_SYSTEMD_RESOLVED_CLASS(klass) \
+    (G_TYPE_CHECK_CLASS_TYPE((klass), NM_TYPE_DNS_SYSTEMD_RESOLVED))
+#define NM_DNS_SYSTEMD_RESOLVED_GET_CLASS(obj) \
+    (G_TYPE_INSTANCE_GET_CLASS((obj), NM_TYPE_DNS_SYSTEMD_RESOLVED, NMDnsSystemdResolvedClass))
+
+typedef struct _NMDnsSystemdResolved      NMDnsSystemdResolved;
+typedef struct _NMDnsSystemdResolvedClass NMDnsSystemdResolvedClass;
+
+GType nm_dns_systemd_resolved_get_type(void);
+
+NMDnsPlugin *nm_dns_systemd_resolved_new(void);
+
+gboolean nm_dns_systemd_resolved_is_running(NMDnsSystemdResolved *self);
+
+#endif /* __NETWORKMANAGER_DNS_SYSTEMD_RESOLVED_H__ */
diff --git a/src/core/dns/nm-dns-unbound.c b/src/core/dns/nm-dns-unbound.c
new file mode 100644
index 00000000..15df3acf
--- /dev/null
+++ b/src/core/dns/nm-dns-unbound.c
@@ -0,0 +1,84 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2014 Red Hat, Inc.
+ * Author: Pavel Šimerda <psimerda@redhat.com>
+ */
+
+#include "src/core/nm-default-daemon.h"
+
+#include "nm-dns-unbound.h"
+
+#include "NetworkManagerUtils.h"
+
+/*****************************************************************************/
+
+struct _NMDnsUnbound {
+    NMDnsPlugin parent;
+};
+
+struct _NMDnsUnboundClass {
+    NMDnsPluginClass parent;
+};
+
+G_DEFINE_TYPE(NMDnsUnbound, nm_dns_unbound, NM_TYPE_DNS_PLUGIN)
+
+/*****************************************************************************/
+
+static gboolean
+update(NMDnsPlugin *            plugin,
+       const NMGlobalDnsConfig *global_config,
+       const CList *            ip_config_lst_head,
+       const char *             hostname,
+       GError **                error)
+{
+    char *        argv[]        = {DNSSEC_TRIGGER_PATH, "--async", "--update", NULL};
+    gs_free_error GError *local = NULL;
+    int                   status;
+
+    /* TODO: We currently call a script installed with the dnssec-trigger
+     * package that queries all information itself. Later, the dependency
+     * on that package will be optional and the only hard dependency will
+     * be unbound.
+     *
+     * Unbound configuration should be later handled by this plugin directly,
+     * without calling custom scripts. The dnssec-trigger functionality
+     * may be eventually merged into NetworkManager.
+     */
+    if (!g_spawn_sync("/", argv, NULL, 0, NULL, NULL, NULL, NULL, &status, &local)) {
+        nm_utils_error_set(error,
+                           NM_UTILS_ERROR_UNKNOWN,
+                           "error spawning dns-trigger: %s",
+                           local->message);
+        return FALSE;
+    }
+    if (status != 0) {
+        nm_utils_error_set(error,
+                           NM_UTILS_ERROR_UNKNOWN,
+                           "dns-trigger exited with error code %d",
+                           status);
+        return FALSE;
+    }
+    return TRUE;
+}
+
+/*****************************************************************************/
+
+static void
+nm_dns_unbound_init(NMDnsUnbound *unbound)
+{}
+
+NMDnsPlugin *
+nm_dns_unbound_new(void)
+{
+    return g_object_new(NM_TYPE_DNS_UNBOUND, NULL);
+}
+
+static void
+nm_dns_unbound_class_init(NMDnsUnboundClass *klass)
+{
+    NMDnsPluginClass *plugin_class = NM_DNS_PLUGIN_CLASS(klass);
+
+    plugin_class->plugin_name = "unbound";
+    plugin_class->is_caching  = TRUE;
+    plugin_class->update      = update;
+}
diff --git a/src/core/dns/nm-dns-unbound.h b/src/core/dns/nm-dns-unbound.h
new file mode 100644
index 00000000..feb33099
--- /dev/null
+++ b/src/core/dns/nm-dns-unbound.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2014 Red Hat, Inc.
+ */
+
+#ifndef __NETWORKMANAGER_DNS_UNBOUND_H__
+#define __NETWORKMANAGER_DNS_UNBOUND_H__
+
+#include "nm-dns-plugin.h"
+
+#define NM_TYPE_DNS_UNBOUND (nm_dns_unbound_get_type())
+#define NM_DNS_UNBOUND(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), NM_TYPE_DNS_UNBOUND, NMDnsUnbound))
+#define NM_DNS_UNBOUND_CLASS(klass) \
+    (G_TYPE_CHECK_CLASS_CAST((klass), NM_TYPE_DNS_UNBOUND, NMDnsUnboundClass))
+#define NM_IS_DNS_UNBOUND(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj), NM_TYPE_DNS_UNBOUND))
+#define NM_IS_DNS_UNBOUND_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), NM_TYPE_DNS_UNBOUND))
+#define NM_DNS_UNBOUND_GET_CLASS(obj) \
+    (G_TYPE_INSTANCE_GET_CLASS((obj), NM_TYPE_DNS_UNBOUND, NMDnsUnboundClass))
+
+typedef struct _NMDnsUnbound      NMDnsUnbound;
+typedef struct _NMDnsUnboundClass NMDnsUnboundClass;
+
+GType nm_dns_unbound_get_type(void);
+
+NMDnsPlugin *nm_dns_unbound_new(void);
+
+#endif /* __NETWORKMANAGER_DNS_UNBOUND_H__ */