/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Copyright (C) 2011 Red Hat, Inc.
 * Copyright (C) 2013 Thomas Bechtold <thomasbechtold@jpberlin.de>
 */

#include "src/core/nm-default-daemon.h"

#include "nm-config.h"

#include <stdio.h>

#include "nm-utils.h"
#include "devices/nm-device.h"
#include "NetworkManagerUtils.h"
#include "libnm-core-intern/nm-core-internal.h"
#include "libnm-core-intern/nm-keyfile-internal.h"
#include "libnm-core-intern/nm-keyfile-utils.h"

#define DEFAULT_CONFIG_MAIN_FILE     NMCONFDIR "/NetworkManager.conf"
#define DEFAULT_CONFIG_DIR           NMCONFDIR "/conf.d"
#define DEFAULT_CONFIG_MAIN_FILE_OLD NMCONFDIR "/nm-system-settings.conf"
#define DEFAULT_SYSTEM_CONFIG_DIR    NMLIBDIR "/conf.d"
#define RUN_CONFIG_DIR               NMRUNDIR "/conf.d"
#define DEFAULT_NO_AUTO_DEFAULT_FILE NMSTATEDIR "/no-auto-default.state"
#define DEFAULT_INTERN_CONFIG_FILE   NMSTATEDIR "/NetworkManager-intern.conf"
#define DEFAULT_STATE_FILE           NMSTATEDIR "/NetworkManager.state"

/*****************************************************************************/

struct NMConfigCmdLineOptions {
    char *                       config_main_file;
    char *                       intern_config_file;
    char *                       config_dir;
    char *                       system_config_dir;
    char *                       state_file;
    char *                       no_auto_default_file;
    char *                       plugins;
    NMConfigConfigureAndQuitType configure_and_quit;

    gboolean is_debug;
    char *   connectivity_uri;

    /* We store interval as signed internally to track whether it's
     * set or not via GOptionEntry
     */
    int   connectivity_interval;
    char *connectivity_response;

    /* @first_start is not provided by command line. It is a convenient hack
     * to pass in an argument to NMConfig. This makes NMConfigCmdLineOptions a
     * misnomer.
     *
     * It is true, if NM is started the first time -- contrary to a restart
     * during the same boot up. That is determined by the content of the
     * /run/NetworManager state directory. */
    bool first_start;
};

typedef struct {
    NMConfigState p;
} State;

/*****************************************************************************/

NM_GOBJECT_PROPERTIES_DEFINE_BASE(PROP_CMD_LINE_OPTIONS, PROP_ATOMIC_SECTION_PREFIXES, );

enum {
    SIGNAL_CONFIG_CHANGED,
    LAST_SIGNAL,
};

static guint signals[LAST_SIGNAL] = {0};

typedef struct {
    NMConfigCmdLineOptions cli;

    NMConfigData *config_data;
    NMConfigData *config_data_orig;

    char *config_dir;
    char *system_config_dir;
    char *no_auto_default_file;
    char *intern_config_file;

    char *log_level;
    char *log_domains;

    NMConfigConfigureAndQuitType configure_and_quit;

    char **atomic_section_prefixes;

    /* The state. This is actually a mutable data member and it makes sense:
     * The regular config is immutable (NMConfigData) and can old be swapped
     * as a whole (via nm_config_set_values() or during reload). Thus, it can
     * be changed, but it is still immutable and is swapped atomically as a
     * whole. Also, we emit a config-changed signal on that occasion.
     *
     * For state, there are no events. You can query it and set it.
     * It only gets read *once* at startup, and later is cached and only
     * written out to disk. Hence, no need for the immutable dance here
     * because the state changes only on explicit actions from the daemon
     * itself. */
    State *state;

    /* the hash table of device states. It is only loaded from disk
     * once and kept immutable afterwards.
     *
     * We also read all state file at once. We don't want to support
     * that they are changed outside of NM (at least not while NM is running).
     * Hence, we read them once, that's it. */
    GHashTable *device_states;

    char **warnings;
} NMConfigPrivate;

struct _NMConfig {
    GObject         parent;
    NMConfigPrivate _priv;
};

struct _NMConfigClass {
    GObjectClass parent;
};

static void nm_config_initable_iface_init(GInitableIface *iface);

G_DEFINE_TYPE_WITH_CODE(NMConfig,
                        nm_config,
                        G_TYPE_OBJECT,
                        G_IMPLEMENT_INTERFACE(G_TYPE_INITABLE, nm_config_initable_iface_init);)

#define NM_CONFIG_GET_PRIVATE(self) _NM_GET_PRIVATE(self, NMConfig, NM_IS_CONFIG)

/*****************************************************************************/

#define _NMLOG_DOMAIN      LOGD_CORE
#define _NMLOG(level, ...) __NMLOG_DEFAULT(level, _NMLOG_DOMAIN, "config", __VA_ARGS__)

/*****************************************************************************/

static void
_set_config_data(NMConfig *self, NMConfigData *new_data, NMConfigChangeFlags reload_flags);

/*****************************************************************************/

int
nm_config_parse_boolean(const char *str, int default_value)
{
    return _nm_utils_ascii_str_to_bool(str, default_value);
}

int
nm_config_keyfile_get_boolean(const GKeyFile *keyfile,
                              const char *    section,
                              const char *    key,
                              int             default_value)
{
    gs_free char *str = NULL;

    g_return_val_if_fail(keyfile != NULL, default_value);
    g_return_val_if_fail(section != NULL, default_value);
    g_return_val_if_fail(key != NULL, default_value);

    str = g_key_file_get_value((GKeyFile *) keyfile, section, key, NULL);
    return nm_config_parse_boolean(str, default_value);
}

gint64
nm_config_keyfile_get_int64(const GKeyFile *keyfile,
                            const char *    section,
                            const char *    key,
                            guint           base,
                            gint64          min,
                            gint64          max,
                            gint64          fallback)
{
    gint64 v;
    int    errsv;
    char * str;

    g_return_val_if_fail(keyfile, fallback);
    g_return_val_if_fail(section, fallback);
    g_return_val_if_fail(key, fallback);

    str = g_key_file_get_value((GKeyFile *) keyfile, section, key, NULL);
    v   = _nm_utils_ascii_str_to_int64(str, base, min, max, fallback);
    if (str) {
        errsv = errno;
        g_free(str);
        errno = errsv;
    }
    return v;
}

char *
nm_config_keyfile_get_value(const GKeyFile *      keyfile,
                            const char *          section,
                            const char *          key,
                            NMConfigGetValueFlags flags)
{
    char *value;

    if (NM_FLAGS_HAS(flags, NM_CONFIG_GET_VALUE_RAW))
        value = g_key_file_get_value((GKeyFile *) keyfile, section, key, NULL);
    else
        value = g_key_file_get_string((GKeyFile *) keyfile, section, key, NULL);

    if (!value)
        return NULL;

    if (NM_FLAGS_HAS(flags, NM_CONFIG_GET_VALUE_STRIP))
        g_strstrip(value);

    if (NM_FLAGS_HAS(flags, NM_CONFIG_GET_VALUE_NO_EMPTY) && !*value) {
        g_free(value);
        return NULL;
    }

    return value;
}

void
nm_config_keyfile_set_string_list(GKeyFile *         keyfile,
                                  const char *       group,
                                  const char *       key,
                                  const char *const *strv,
                                  gssize             len)
{
    gsize l;
    char *new_value;

    if (len < 0)
        len = strv ? g_strv_length((char **) strv) : 0;

    g_key_file_set_string_list(keyfile, group, key, strv, len);

    /* g_key_file_set_string_list() appends a trailing separator to the value.
     * We don't like that, get rid of it. */

    new_value = g_key_file_get_value(keyfile, group, key, NULL);
    if (!new_value)
        return;

    l = strlen(new_value);
    if (l > 0 && new_value[l - 1] == NM_CONFIG_KEYFILE_LIST_SEPARATOR) {
        /* Maybe we should check that value doesn't end with "\\,", i.e.
         * with an escaped separator. But the way g_key_file_set_string_list()
         * is implemented (currently), it always adds a trailing separator. */
        new_value[l - 1] = '\0';
        g_key_file_set_value(keyfile, group, key, new_value);
    }
    g_free(new_value);
}

/*****************************************************************************/

const char *const *
nm_config_get_warnings(NMConfig *config)
{
    return (const char *const *) NM_CONFIG_GET_PRIVATE(config)->warnings;
}

void
nm_config_clear_warnings(NMConfig *config)
{
    nm_clear_pointer(&NM_CONFIG_GET_PRIVATE(config)->warnings, g_strfreev);
}

NMConfigData *
nm_config_get_data(NMConfig *config)
{
    g_return_val_if_fail(config != NULL, NULL);

    return NM_CONFIG_GET_PRIVATE(config)->config_data;
}

/* The NMConfigData instance is reloadable and will be swapped on reload.
 * nm_config_get_data_orig() returns the original configuration, when the NMConfig
 * instance was created. */
NMConfigData *
nm_config_get_data_orig(NMConfig *config)
{
    g_return_val_if_fail(config != NULL, NULL);

    return NM_CONFIG_GET_PRIVATE(config)->config_data_orig;
}

const char *
nm_config_get_log_level(NMConfig *config)
{
    g_return_val_if_fail(config != NULL, NULL);

    return NM_CONFIG_GET_PRIVATE(config)->log_level;
}

const char *
nm_config_get_log_domains(NMConfig *config)
{
    g_return_val_if_fail(config != NULL, NULL);

    return NM_CONFIG_GET_PRIVATE(config)->log_domains;
}

NMConfigConfigureAndQuitType
nm_config_get_configure_and_quit(NMConfig *config)
{
    return NM_CONFIG_GET_PRIVATE(config)->configure_and_quit;
}

gboolean
nm_config_get_is_debug(NMConfig *config)
{
    return NM_CONFIG_GET_PRIVATE(config)->cli.is_debug;
}

gboolean
nm_config_get_first_start(NMConfig *config)
{
    return NM_CONFIG_GET_PRIVATE(config)->cli.first_start;
}

const char *
nm_config_get_no_auto_default_file(NMConfig *config)
{
    return NM_CONFIG_GET_PRIVATE(config)->no_auto_default_file;
}

/*****************************************************************************/

static char **
no_auto_default_from_file(const char *no_auto_default_file)
{
    gs_free char *data = NULL;
    const char ** list = NULL;
    gsize         i;

    if (no_auto_default_file && g_file_get_contents(no_auto_default_file, &data, NULL, NULL))
        list = nm_utils_strsplit_set(data, "\n");

    if (list) {
        for (i = 0; list[i]; i++)
            list[i] = nm_utils_str_utf8safe_unescape_cp(list[i], NM_UTILS_STR_UTF8_SAFE_FLAG_NONE);
    }

    /* The returned buffer here is not at all compact. That means, it has additional
     * memory allocations and is larger than needed. That means, you should not keep
     * this result around, only process it further and free it. */
    return (char **) list;
}

static gboolean
no_auto_default_to_file(const char *       no_auto_default_file,
                        const char *const *no_auto_default,
                        GError **          error)
{
    nm_auto_free_gstring GString *data = NULL;
    gsize                         i;

    data = g_string_new("");
    for (i = 0; no_auto_default && no_auto_default[i]; i++) {
        gs_free char *s_to_free = NULL;
        const char *  s         = no_auto_default[i];

        s = nm_utils_str_utf8safe_escape(s,
                                         NM_UTILS_STR_UTF8_SAFE_FLAG_ESCAPE_CTRL
                                             | NM_UTILS_STR_UTF8_SAFE_FLAG_ESCAPE_NON_ASCII,
                                         &s_to_free);
        g_string_append(data, s);
        g_string_append_c(data, '\n');
    }
    return g_file_set_contents(no_auto_default_file, data->str, data->len, error);
}

gboolean
nm_config_get_no_auto_default_for_device(NMConfig *self, NMDevice *device)
{
    NMConfigPrivate *priv;

    g_return_val_if_fail(NM_IS_CONFIG(self), FALSE);

    priv = NM_CONFIG_GET_PRIVATE(self);

    if (priv->configure_and_quit == NM_CONFIG_CONFIGURE_AND_QUIT_INITRD)
        return TRUE;

    return nm_config_data_get_no_auto_default_for_device(priv->config_data, device);
}

void
nm_config_set_no_auto_default_for_device(NMConfig *self, NMDevice *device)
{
    NMConfigPrivate *    priv;
    GError *             error        = NULL;
    NMConfigData *       new_data     = NULL;
    gs_free char *       spec_to_free = NULL;
    const char *         ifname;
    const char *         hw_address;
    const char *         spec;
    const char *const *  no_auto_default_current;
    gs_free const char **no_auto_default_new = NULL;
    gboolean             is_fake;
    gsize                len;
    gssize               idx;

    g_return_if_fail(NM_IS_CONFIG(self));
    g_return_if_fail(NM_IS_DEVICE(device));

    priv = NM_CONFIG_GET_PRIVATE(self);

    hw_address = nm_device_get_permanent_hw_address_full(device, TRUE, &is_fake);

    if (!hw_address) {
        /* No MAC address, not even a fake one. We don't do anything for this device. */
        return;
    }

    if (is_fake) {
        /* A fake MAC address, no point in storing it to the file.
         * Also, nm_match_spec_device() would ignore fake MAC addresses.
         *
         * Instead, try the interface-name...  */
        ifname = nm_device_get_ip_iface(device);
        if (!nm_utils_ifname_valid_kernel(ifname, NULL))
            return;

        spec_to_free = g_strdup_printf(NM_MATCH_SPEC_INTERFACE_NAME_TAG "=%s", ifname);
        spec         = spec_to_free;
    } else
        spec = hw_address;

    no_auto_default_current = nm_config_data_get_no_auto_default(priv->config_data);

    len = NM_PTRARRAY_LEN(no_auto_default_current);

    idx = nm_utils_strv_find_binary_search(no_auto_default_current, len, spec);
    if (idx >= 0) {
        /* @spec is already blocked. We don't have to update our in-memory representation.
         * Maybe we should write to no_auto_default_file anew, but let's save that too. */
        return;
    }

    idx = ~idx;

    no_auto_default_new = g_new(const char *, len + 2);
    if (idx > 0)
        memcpy(no_auto_default_new, no_auto_default_current, sizeof(const char *) * idx);
    no_auto_default_new[idx] = spec;
    if (idx < len)
        memcpy(&no_auto_default_new[idx + 1],
               &no_auto_default_current[idx],
               sizeof(const char *) * (len - idx));
    no_auto_default_new[len + 1] = NULL;

    if (!no_auto_default_to_file(priv->no_auto_default_file, no_auto_default_new, &error)) {
        _LOGW("Could not update no-auto-default.state file: %s", error->message);
        g_error_free(error);
    }

    new_data = nm_config_data_new_update_no_auto_default(priv->config_data, no_auto_default_new);

    _set_config_data(self, new_data, NM_CONFIG_CHANGE_CAUSE_NO_AUTO_DEFAULT);
}

/*****************************************************************************/

static void
_nm_config_cmd_line_options_clear(NMConfigCmdLineOptions *cli)
{
    nm_clear_g_free(&cli->config_main_file);
    nm_clear_g_free(&cli->config_dir);
    nm_clear_g_free(&cli->system_config_dir);
    nm_clear_g_free(&cli->no_auto_default_file);
    nm_clear_g_free(&cli->intern_config_file);
    nm_clear_g_free(&cli->state_file);
    nm_clear_g_free(&cli->plugins);
    cli->configure_and_quit = NM_CONFIG_CONFIGURE_AND_QUIT_DISABLED;
    cli->is_debug           = FALSE;
    nm_clear_g_free(&cli->connectivity_uri);
    nm_clear_g_free(&cli->connectivity_response);
    cli->connectivity_interval = -1;
    cli->first_start           = FALSE;
}

static void
_nm_config_cmd_line_options_copy(const NMConfigCmdLineOptions *cli, NMConfigCmdLineOptions *dst)
{
    g_return_if_fail(cli);
    g_return_if_fail(dst);
    g_return_if_fail(cli != dst);

    _nm_config_cmd_line_options_clear(dst);
    dst->config_dir            = g_strdup(cli->config_dir);
    dst->system_config_dir     = g_strdup(cli->system_config_dir);
    dst->config_main_file      = g_strdup(cli->config_main_file);
    dst->no_auto_default_file  = g_strdup(cli->no_auto_default_file);
    dst->intern_config_file    = g_strdup(cli->intern_config_file);
    dst->state_file            = g_strdup(cli->state_file);
    dst->plugins               = g_strdup(cli->plugins);
    dst->configure_and_quit    = cli->configure_and_quit;
    dst->is_debug              = cli->is_debug;
    dst->connectivity_uri      = g_strdup(cli->connectivity_uri);
    dst->connectivity_response = g_strdup(cli->connectivity_response);
    dst->connectivity_interval = cli->connectivity_interval;
    dst->first_start           = cli->first_start;
}

NMConfigCmdLineOptions *
nm_config_cmd_line_options_new(gboolean first_start)
{
    NMConfigCmdLineOptions *cli = g_new0(NMConfigCmdLineOptions, 1);

    _nm_config_cmd_line_options_clear(cli);

    cli->first_start = first_start;

    return cli;
}

void
nm_config_cmd_line_options_free(NMConfigCmdLineOptions *cli)
{
    g_return_if_fail(cli);

    _nm_config_cmd_line_options_clear(cli);
    g_free(cli);
}

static NMConfigConfigureAndQuitType
string_to_configure_and_quit(const char *value, GError **error)
{
    NMConfigConfigureAndQuitType ret;

    if (value == NULL)
        return NM_CONFIG_CONFIGURE_AND_QUIT_DISABLED;

    if (nm_streq(value, "initrd"))
        return NM_CONFIG_CONFIGURE_AND_QUIT_INITRD;

    ret = nm_config_parse_boolean(value, NM_CONFIG_CONFIGURE_AND_QUIT_INVALID);
    if (ret == NM_CONFIG_CONFIGURE_AND_QUIT_INVALID)
        g_set_error(error, 1, 0, N_("'%s' is not valid"), value);

    return ret;
}

static gboolean
parse_configure_and_quit(const char *option_name,
                         const char *value,
                         gpointer    user_data,
                         GError **   error)
{
    NMConfigCmdLineOptions *cli = user_data;

    if (value == NULL)
        cli->configure_and_quit = NM_CONFIG_CONFIGURE_AND_QUIT_ENABLED;
    else
        cli->configure_and_quit = string_to_configure_and_quit(value, error);

    if (cli->configure_and_quit == NM_CONFIG_CONFIGURE_AND_QUIT_INVALID) {
        g_prefix_error(error, N_("Bad '%s' option: "), option_name);
        return FALSE;
    }

    return TRUE;
}

void
nm_config_cmd_line_options_add_to_entries(NMConfigCmdLineOptions *cli, GOptionContext *opt_ctx)
{
    GOptionGroup *group;
    GOptionEntry  config_options[] = {
        {"config",
         0,
         0,
         G_OPTION_ARG_FILENAME,
         &cli->config_main_file,
         N_("Config file location"),
         DEFAULT_CONFIG_MAIN_FILE},
        {"config-dir",
         0,
         0,
         G_OPTION_ARG_FILENAME,
         &cli->config_dir,
         N_("Config directory location"),
         DEFAULT_CONFIG_DIR},
        {"system-config-dir",
         0,
         0,
         G_OPTION_ARG_FILENAME,
         &cli->system_config_dir,
         N_("System config directory location"),
         DEFAULT_SYSTEM_CONFIG_DIR},
        {"intern-config",
         0,
         0,
         G_OPTION_ARG_FILENAME,
         &cli->intern_config_file,
         N_("Internal config file location"),
         DEFAULT_INTERN_CONFIG_FILE},
        {"state-file",
         0,
         0,
         G_OPTION_ARG_FILENAME,
         &cli->state_file,
         N_("State file location"),
         DEFAULT_STATE_FILE},
        {"no-auto-default",
         0,
         G_OPTION_FLAG_HIDDEN,
         G_OPTION_ARG_FILENAME,
         &cli->no_auto_default_file,
         N_("State file for no-auto-default devices"),
         DEFAULT_NO_AUTO_DEFAULT_FILE},
        {"plugins",
         0,
         0,
         G_OPTION_ARG_STRING,
         &cli->plugins,
         N_("List of plugins separated by ','"),
         NM_CONFIG_DEFAULT_MAIN_PLUGINS},
        {"configure-and-quit",
         0,
         G_OPTION_FLAG_OPTIONAL_ARG,
         G_OPTION_ARG_CALLBACK,
         parse_configure_and_quit,
         N_("Quit after initial configuration"),
         NULL},
        {"debug",
         'd',
         0,
         G_OPTION_ARG_NONE,
         &cli->is_debug,
         N_("Don't become a daemon, and log to stderr"),
         NULL},

        /* These three are hidden for now, and should eventually just go away. */
        {"connectivity-uri",
         0,
         G_OPTION_FLAG_HIDDEN,
         G_OPTION_ARG_STRING,
         &cli->connectivity_uri,
         N_("An http(s) address for checking internet connectivity"),
         "http://example.com"},
        {"connectivity-interval",
         0,
         G_OPTION_FLAG_HIDDEN,
         G_OPTION_ARG_INT,
         &cli->connectivity_interval,
         N_("The interval between connectivity checks (in seconds)"),
         G_STRINGIFY(NM_CONFIG_DEFAULT_CONNECTIVITY_INTERVAL)},
        {"connectivity-response",
         0,
         G_OPTION_FLAG_HIDDEN,
         G_OPTION_ARG_STRING,
         &cli->connectivity_response,
         N_("The expected start of the response"),
         NM_CONFIG_DEFAULT_CONNECTIVITY_RESPONSE},
        {0},
    };

    g_return_if_fail(opt_ctx);
    g_return_if_fail(cli);

    group = g_option_group_new("nm",
                               N_("NetworkManager options"),
                               N_("Show NetworkManager options"),
                               cli,
                               NULL);

    g_option_group_add_entries(group, config_options);
    g_option_context_add_group(opt_ctx, group);
}

/*****************************************************************************/

GKeyFile *
nm_config_create_keyfile()
{
    GKeyFile *keyfile;

    keyfile = g_key_file_new();
    g_key_file_set_list_separator(keyfile, NM_CONFIG_KEYFILE_LIST_SEPARATOR);
    return keyfile;
}

/* this is an external variable, to make loading testable. Other then that,
 * no code is supposed to change this. */
guint _nm_config_match_nm_version = NM_VERSION;
char *_nm_config_match_env        = NULL;

static gboolean
ignore_config_snippet(GKeyFile *keyfile, gboolean is_base_config)
{
    GSList *             specs;
    gboolean             as_bool;
    NMMatchSpecMatchType match_type;

    if (is_base_config)
        return FALSE;

    if (!g_key_file_has_key(keyfile,
                            NM_CONFIG_KEYFILE_GROUP_CONFIG,
                            NM_CONFIG_KEYFILE_KEY_CONFIG_ENABLE,
                            NULL))
        return FALSE;

    /* first, let's try to parse the value as plain boolean. If that is possible, we don't treat
     * the value as match-spec. */
    as_bool = nm_config_keyfile_get_boolean(keyfile,
                                            NM_CONFIG_KEYFILE_GROUP_CONFIG,
                                            NM_CONFIG_KEYFILE_KEY_CONFIG_ENABLE,
                                            -1);
    if (as_bool != -1)
        return !as_bool;

    if (G_UNLIKELY(!_nm_config_match_env)) {
        const char *e;

        e                    = g_getenv("NM_CONFIG_ENABLE_TAG");
        _nm_config_match_env = g_strdup(e ?: "");
    }

    /* second, interpret the value as match-spec. */
    specs      = nm_config_get_match_spec(keyfile,
                                     NM_CONFIG_KEYFILE_GROUP_CONFIG,
                                     NM_CONFIG_KEYFILE_KEY_CONFIG_ENABLE,
                                     NULL);
    match_type = nm_match_spec_config(specs, _nm_config_match_nm_version, _nm_config_match_env);
    g_slist_free_full(specs, g_free);

    return match_type != NM_MATCH_SPEC_MATCH;
}

static int
_sort_groups_cmp(const char **pa, const char **pb, gpointer dummy)
{
    const char *a = *pa;
    const char *b = *pb;
    gboolean    a_is_connection, b_is_connection;
    gboolean    a_is_device, b_is_device;

    a_is_connection = NM_STR_HAS_PREFIX(a, NM_CONFIG_KEYFILE_GROUPPREFIX_CONNECTION);
    b_is_connection = NM_STR_HAS_PREFIX(b, NM_CONFIG_KEYFILE_GROUPPREFIX_CONNECTION);

    if (a_is_connection != b_is_connection) {
        /* one is a [connection*] entry, the other not. We sort [connection*] entries
         * after.  */
        if (a_is_connection)
            return 1;
        return -1;
    }
    if (a_is_connection) {
        /* both are [connection.\+] entries. Reverse their order.
         * One of the sections might be literally [connection]. That section
         * is special and its order will be fixed later. It doesn't actually
         * matter here how it compares with [connection.\+] sections. */
        return pa > pb ? -1 : 1;
    }

    a_is_device = NM_STR_HAS_PREFIX(a, NM_CONFIG_KEYFILE_GROUPPREFIX_DEVICE);
    b_is_device = NM_STR_HAS_PREFIX(b, NM_CONFIG_KEYFILE_GROUPPREFIX_DEVICE);

    if (a_is_device != b_is_device) {
        /* one is a [device*] entry, the other not. We sort [device*] entries
         * after.  */
        if (a_is_device)
            return 1;
        return -1;
    }
    if (a_is_device) {
        /* both are [device.\+] entries. Reverse their order.
         * One of the sections might be literally [device]. That section
         * is special and its order will be fixed later. It doesn't actually
         * matter here how it compares with [device.\+] sections. */
        return pa > pb ? -1 : 1;
    }

    /* don't reorder the rest. */
    return 0;
}

void
_nm_config_sort_groups(char **groups, gsize ngroups)
{
    if (ngroups > 1) {
        g_qsort_with_data(groups,
                          ngroups,
                          sizeof(char *),
                          (GCompareDataFunc) _sort_groups_cmp,
                          NULL);
    }
}

static gboolean
_setting_is_device_spec(const char *group, const char *key)
{
#define _IS(group_v, key_v) (nm_streq(group, "" group_v "") && nm_streq(key, "" key_v ""))

    return _IS(NM_CONFIG_KEYFILE_GROUP_MAIN, NM_CONFIG_KEYFILE_KEY_MAIN_NO_AUTO_DEFAULT)
           || _IS(NM_CONFIG_KEYFILE_GROUP_MAIN, NM_CONFIG_KEYFILE_KEY_MAIN_IGNORE_CARRIER)
           || _IS(NM_CONFIG_KEYFILE_GROUP_MAIN, NM_CONFIG_KEYFILE_KEY_MAIN_ASSUME_IPV6LL_ONLY)
           || _IS(NM_CONFIG_KEYFILE_GROUP_KEYFILE, NM_CONFIG_KEYFILE_KEY_KEYFILE_UNMANAGED_DEVICES)
           || (NM_STR_HAS_PREFIX(group, NM_CONFIG_KEYFILE_GROUPPREFIX_CONNECTION)
               && nm_streq(key, NM_CONFIG_KEYFILE_KEY_MATCH_DEVICE))
           || (NM_STR_HAS_PREFIX(group, NM_CONFIG_KEYFILE_GROUPPREFIX_DEVICE)
               && nm_streq(key, NM_CONFIG_KEYFILE_KEY_MATCH_DEVICE));
}

static gboolean
_setting_is_connection_spec(const char *group, const char *key)
{
    return NM_STR_HAS_PREFIX(group, NM_CONFIG_KEYFILE_GROUPPREFIX_DEVICE)
           && nm_streq(key, NM_CONFIG_KEYFILE_KEY_DEVICE_ALLOWED_CONNECTIONS);
}

static gboolean
_setting_is_string_list(const char *group, const char *key)
{
    return _IS(NM_CONFIG_KEYFILE_GROUP_MAIN, NM_CONFIG_KEYFILE_KEY_MAIN_PLUGINS)
           || _IS(NM_CONFIG_KEYFILE_GROUP_MAIN, NM_CONFIG_KEYFILE_KEY_MAIN_DEBUG)
           || _IS(NM_CONFIG_KEYFILE_GROUP_LOGGING, NM_CONFIG_KEYFILE_KEY_LOGGING_DOMAINS)
           || NM_STR_HAS_PREFIX(group, NM_CONFIG_KEYFILE_GROUPPREFIX_TEST_APPEND_STRINGLIST);
#undef _IS
}

typedef struct {
    char *             group;
    const char *const *keys;
    bool               is_prefix : 1;
    bool               is_connection : 1;
} ConfigGroup;

/* The following comment is used by check-config-options.sh, don't remove it. */
/* START OPTION LIST */

static const ConfigGroup config_groups[] = {
    {
        .group = NM_CONFIG_KEYFILE_GROUP_MAIN,
        .keys  = NM_MAKE_STRV(NM_CONFIG_KEYFILE_KEY_MAIN_ASSUME_IPV6LL_ONLY,
                             NM_CONFIG_KEYFILE_KEY_MAIN_AUTH_POLKIT,
                             NM_CONFIG_KEYFILE_KEY_MAIN_AUTOCONNECT_RETRIES_DEFAULT,
                             NM_CONFIG_KEYFILE_KEY_MAIN_CONFIGURE_AND_QUIT,
                             NM_CONFIG_KEYFILE_KEY_MAIN_DEBUG,
                             NM_CONFIG_KEYFILE_KEY_MAIN_DHCP,
                             NM_CONFIG_KEYFILE_KEY_MAIN_DNS,
                             NM_CONFIG_KEYFILE_KEY_MAIN_FIREWALL_BACKEND,
                             NM_CONFIG_KEYFILE_KEY_MAIN_HOSTNAME_MODE,
                             NM_CONFIG_KEYFILE_KEY_MAIN_IGNORE_CARRIER,
                             NM_CONFIG_KEYFILE_KEY_MAIN_IWD_CONFIG_PATH,
                             NM_CONFIG_KEYFILE_KEY_MAIN_MONITOR_CONNECTION_FILES,
                             NM_CONFIG_KEYFILE_KEY_MAIN_NO_AUTO_DEFAULT,
                             NM_CONFIG_KEYFILE_KEY_MAIN_PLUGINS,
                             NM_CONFIG_KEYFILE_KEY_MAIN_RC_MANAGER,
                             NM_CONFIG_KEYFILE_KEY_MAIN_SLAVES_ORDER,
                             NM_CONFIG_KEYFILE_KEY_MAIN_SYSTEMD_RESOLVED, ),
    },
    {
        .group = NM_CONFIG_KEYFILE_GROUP_LOGGING,
        .keys  = NM_MAKE_STRV(NM_CONFIG_KEYFILE_KEY_LOGGING_AUDIT,
                             NM_CONFIG_KEYFILE_KEY_LOGGING_BACKEND,
                             NM_CONFIG_KEYFILE_KEY_LOGGING_DOMAINS,
                             NM_CONFIG_KEYFILE_KEY_LOGGING_LEVEL, ),
    },
    {
        .group = NM_CONFIG_KEYFILE_GROUP_CONNECTIVITY,
        .keys  = NM_MAKE_STRV(NM_CONFIG_KEYFILE_KEY_CONNECTIVITY_ENABLED,
                             NM_CONFIG_KEYFILE_KEY_CONNECTIVITY_INTERVAL,
                             NM_CONFIG_KEYFILE_KEY_CONNECTIVITY_RESPONSE,
                             NM_CONFIG_KEYFILE_KEY_CONNECTIVITY_URI, ),
    },
    {
        .group = NM_CONFIG_KEYFILE_GROUP_KEYFILE,
        .keys  = NM_MAKE_STRV(NM_CONFIG_KEYFILE_KEY_KEYFILE_HOSTNAME,
                             NM_CONFIG_KEYFILE_KEY_KEYFILE_PATH,
                             NM_CONFIG_KEYFILE_KEY_KEYFILE_UNMANAGED_DEVICES, ),
    },
    {
        .group = NM_CONFIG_KEYFILE_GROUP_IFUPDOWN,
        .keys  = NM_MAKE_STRV(NM_CONFIG_KEYFILE_KEY_IFUPDOWN_MANAGED, ),
    },
    {
        .group     = NM_CONFIG_KEYFILE_GROUPPREFIX_DEVICE,
        .is_prefix = TRUE,
        .keys      = NM_MAKE_STRV(NM_CONFIG_KEYFILE_KEY_DEVICE_CARRIER_WAIT_TIMEOUT,
                             NM_CONFIG_KEYFILE_KEY_DEVICE_IGNORE_CARRIER,
                             NM_CONFIG_KEYFILE_KEY_DEVICE_MANAGED,
                             NM_CONFIG_KEYFILE_KEY_DEVICE_SRIOV_NUM_VFS,
                             NM_CONFIG_KEYFILE_KEY_DEVICE_KEEP_CONFIGURATION,
                             NM_CONFIG_KEYFILE_KEY_DEVICE_ALLOWED_CONNECTIONS,
                             NM_CONFIG_KEYFILE_KEY_DEVICE_WIFI_BACKEND,
                             NM_CONFIG_KEYFILE_KEY_DEVICE_WIFI_SCAN_RAND_MAC_ADDRESS,
                             NM_CONFIG_KEYFILE_KEY_DEVICE_WIFI_SCAN_GENERATE_MAC_ADDRESS_MASK,
                             NM_CONFIG_KEYFILE_KEY_DEVICE_WIFI_IWD_AUTOCONNECT,
                             NM_CONFIG_KEYFILE_KEY_MATCH_DEVICE,
                             NM_CONFIG_KEYFILE_KEY_STOP_MATCH, ),
    },
    {
        .group = NM_CONFIG_KEYFILE_GROUP_GLOBAL_DNS,
        .keys  = NM_MAKE_STRV(NM_CONFIG_KEYFILE_KEY_GLOBAL_DNS_OPTIONS,
                             NM_CONFIG_KEYFILE_KEY_GLOBAL_DNS_SEARCHES, ),
    },
    {
        .group     = NM_CONFIG_KEYFILE_GROUPPREFIX_GLOBAL_DNS_DOMAIN,
        .is_prefix = TRUE,
        .keys      = NM_MAKE_STRV(NM_CONFIG_KEYFILE_KEY_GLOBAL_DNS_DOMAIN_SERVERS,
                             NM_CONFIG_KEYFILE_KEY_GLOBAL_DNS_DOMAIN_OPTIONS, ),
    },
    {
        .group         = NM_CONFIG_KEYFILE_GROUPPREFIX_CONNECTION,
        .is_prefix     = TRUE,
        .is_connection = TRUE,
        .keys =
            NM_MAKE_STRV(NM_CONFIG_KEYFILE_KEY_MATCH_DEVICE, NM_CONFIG_KEYFILE_KEY_STOP_MATCH, ),
    },
    {} /* sentinel */
};

/* The following comment is used by check-config-options.sh, don't remove it. */
/* END OPTION LIST */

static gboolean
check_config_key(const char *group, const char *key)
{
    const ConfigGroup *g;
    const char *const *k;
    const char **      ptr;

#if NM_MORE_ASSERTS > 10
    {
        static gboolean checked = FALSE;
        const char **   ptr1, **ptr2;

        /* check for duplicate elements in the static list */

        if (!checked) {
            for (ptr1 = __start_connection_defaults; ptr1 < __stop_connection_defaults; ptr1++) {
                for (ptr2 = ptr1 + 1; ptr2 < __stop_connection_defaults; ptr2++)
                    nm_assert(!nm_streq(*ptr1, *ptr2));
            }
            checked = TRUE;
        }
    }
#endif

    for (g = config_groups; g->group; g++) {
        if ((!g->is_prefix && nm_streq(group, g->group))
            || (g->is_prefix && g_str_has_prefix(group, g->group)))
            break;
    }

    if (!g->group)
        return FALSE;

    for (k = g->keys; *k; k++) {
        if (nm_streq(key, *k))
            return TRUE;
    }

    if (g->is_connection) {
        for (ptr = __start_connection_defaults; ptr < __stop_connection_defaults; ptr++) {
            if (nm_streq(key, *ptr))
                return TRUE;
        }
        return FALSE;
    }

    return FALSE;
}

static gboolean
read_config(GKeyFile *  keyfile,
            gboolean    is_base_config,
            const char *dirname,
            const char *path,
            GPtrArray * warnings,
            GError **   error)
{
    nm_auto_unref_keyfile GKeyFile *kf        = NULL;
    gs_strfreev char **             groups    = NULL;
    gs_free char *                  path_free = NULL;
    gsize                           ngroups;
    gsize                           nkeys;
    int                             g;
    int                             k;

    g_return_val_if_fail(keyfile, FALSE);
    g_return_val_if_fail(path, FALSE);
    g_return_val_if_fail(!error || !*error, FALSE);

    if (dirname) {
        path_free = g_build_filename(dirname, path, NULL);
        path      = path_free;
    }

    if (g_file_test(path, G_FILE_TEST_EXISTS) == FALSE) {
        g_set_error(error, G_KEY_FILE_ERROR, G_KEY_FILE_ERROR_NOT_FOUND, "file %s not found", path);
        return FALSE;
    }

    _LOGD("Reading config file '%s'", path);

    kf = nm_config_create_keyfile();
    if (!g_key_file_load_from_file(kf, path, G_KEY_FILE_NONE, error)) {
        g_prefix_error(error, "%s: ", path);
        return FALSE;
    }

    if (ignore_config_snippet(kf, is_base_config))
        return TRUE;

    /* the config-group is internal to every configuration snippets. It doesn't make sense
     * to merge it into the global configuration, and it doesn't make sense to preserve the
     * group beyond this point. */
    g_key_file_remove_group(kf, NM_CONFIG_KEYFILE_GROUP_CONFIG, NULL);

    /* Override the current settings with the new ones */
    groups = g_key_file_get_groups(kf, &ngroups);
    if (!groups)
        ngroups = 0;

    /* Within one file we reverse the order of the '[connection.\+] sections.
     * Here we merge the current file (@kf) into @keyfile. As we merge multiple
     * files, earlier sections (with lower priority) will be added first.
     * But within one file, we want a top-to-bottom order. This means we
     * must reverse the order within each file.
     * At the very end, we will revert the order of all sections again and
     * get thus the right behavior. This final reversing is done in
     * NMConfigData:_get_connection_infos().  */
    _nm_config_sort_groups(groups, ngroups);

    for (g = 0; groups && groups[g]; g++) {
        const char *       group = groups[g];
        gs_strfreev char **keys  = NULL;

        if (NM_STR_HAS_PREFIX(group, NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN)) {
            /* internal groups cannot be set by user configuration. */
            continue;
        }
        keys = g_key_file_get_keys(kf, group, &nkeys, NULL);
        if (!keys)
            continue;
        for (k = 0; keys[k]; k++) {
            gs_free char *new_value = NULL;
            const char *  key;
            char          last_char;
            gsize         key_len;

            key = keys[k];
            nm_assert(key && *key);

            if (NM_STR_HAS_PREFIX_WITH_MORE(key, NM_CONFIG_KEYFILE_KEYPREFIX_WAS)
                || NM_STR_HAS_PREFIX_WITH_MORE(key, NM_CONFIG_KEYFILE_KEYPREFIX_SET)) {
                /* these keys are protected. We ignore them if the user sets them. */
                continue;
            }

            if (nm_streq(key, NM_CONFIG_KEYFILE_KEY_ATOMIC_SECTION_WAS)) {
                /* the "was" key is protected and it cannot be set by user configuration. */
                continue;
            }

            key_len   = strlen(key);
            last_char = key[key_len - 1];
            if (key_len > 1 && (last_char == '+' || last_char == '-')) {
                gs_free char *base_key = g_strndup(key, key_len - 1);
                gboolean      is_string_list;
                gboolean      old_val_was_set = FALSE;

                is_string_list = _setting_is_string_list(group, base_key);

                if (is_string_list || _setting_is_device_spec(group, base_key)
                    || _setting_is_connection_spec(group, base_key)) {
                    gs_unref_ptrarray  GPtrArray *new = g_ptr_array_new_with_free_func(g_free);
                    char **            iter_val;
                    gs_strfreev char **old_val = NULL;
                    gs_free char **    new_val = NULL;

                    if (is_string_list) {
                        gs_free_error GError *old_error = NULL;

                        old_val =
                            g_key_file_get_string_list(keyfile, group, base_key, NULL, &old_error);
                        new_val = g_key_file_get_string_list(kf, group, key, NULL, NULL);
                        if (nm_streq(group, NM_CONFIG_KEYFILE_GROUP_MAIN)
                            && nm_streq(base_key, "plugins")) {
                            old_val_was_set = !nm_keyfile_error_is_not_found(old_error);
                            if (!old_val && !old_val_was_set) {
                                /* we must fill the unspecified value with the compile-time default. */
                                g_key_file_set_value(keyfile,
                                                     group,
                                                     base_key,
                                                     NM_CONFIG_DEFAULT_MAIN_PLUGINS);
                                old_val         = g_key_file_get_string_list(keyfile,
                                                                     group,
                                                                     base_key,
                                                                     NULL,
                                                                     NULL);
                                old_val_was_set = TRUE;
                            }
                        }
                    } else {
                        gs_free char *old_sval =
                            nm_config_keyfile_get_value(keyfile,
                                                        group,
                                                        base_key,
                                                        NM_CONFIG_GET_VALUE_TYPE_SPEC);
                        gs_free char *new_sval =
                            nm_config_keyfile_get_value(kf,
                                                        group,
                                                        key,
                                                        NM_CONFIG_GET_VALUE_TYPE_SPEC);
                        nm_auto_free_slist GSList *old_specs = nm_match_spec_split(old_sval);
                        nm_auto_free_slist GSList *new_specs = nm_match_spec_split(new_sval);

                        /* the key is a device spec. This is a special kind of string-list, that
                         * we must split differently. */
                        old_val = _nm_utils_slist_to_strv(old_specs, FALSE);
                        new_val = _nm_utils_slist_to_strv(new_specs, FALSE);
                    }

                    /* merge the string lists, by omitting duplicates. */

                    for (iter_val = old_val; iter_val && *iter_val; iter_val++) {
                        if (last_char != '-'
                            || nm_utils_strv_find_first(new_val, -1, *iter_val) < 0)
                            g_ptr_array_add(new, g_strdup(*iter_val));
                    }
                    for (iter_val = new_val; iter_val && *iter_val; iter_val++) {
                        /* don't add duplicates. That means an "option=a,b"; "option+=a,c" results in "option=a,b,c" */
                        if (last_char == '+'
                            && nm_utils_strv_find_first(old_val, -1, *iter_val) < 0)
                            g_ptr_array_add(new, *iter_val);
                        else
                            g_free(*iter_val);
                    }

                    if (new->len > 0) {
                        if (is_string_list)
                            nm_config_keyfile_set_string_list(keyfile,
                                                              group,
                                                              base_key,
                                                              (const char *const *) new->pdata,
                                                              new->len);
                        else {
                            nm_auto_free_slist GSList *specs        = NULL;
                            gs_free char *             specs_joined = NULL;

                            g_ptr_array_add(new, NULL);
                            specs = _nm_utils_strv_to_slist((char **) new->pdata, FALSE);

                            specs_joined = nm_match_spec_join(specs);

                            g_key_file_set_value(keyfile, group, base_key, specs_joined);
                        }
                    } else {
                        if (is_string_list && !old_val_was_set)
                            g_key_file_remove_key(keyfile, group, base_key, NULL);
                        else
                            g_key_file_set_value(keyfile, group, base_key, "");
                    }
                } else {
                    /* For any other settings we don't support extending the option with +/-.
                     * Just drop the key. */
                }
                continue;
            }

            new_value = g_key_file_get_value(kf, group, key, NULL);
            g_key_file_set_value(keyfile, group, key, new_value);

            if (!check_config_key(group, key)) {
                g_ptr_array_add(warnings,
                                g_strdup_printf("unknown key '%s' in section [%s] of file '%s'",
                                                key,
                                                group,
                                                path));
            }
        }
    }

    return TRUE;
}

static gboolean
read_base_config(GKeyFile *  keyfile,
                 const char *cli_config_main_file,
                 char **     out_config_main_file,
                 GPtrArray * warnings,
                 GError **   error)
{
    GError *my_error = NULL;

    g_return_val_if_fail(keyfile, FALSE);
    g_return_val_if_fail(out_config_main_file && !*out_config_main_file, FALSE);
    g_return_val_if_fail(!error || !*error, FALSE);

    /* Try a user-specified config file first */
    if (cli_config_main_file) {
        /* Bad user-specific config file path is a hard error */
        if (read_config(keyfile, TRUE, NULL, cli_config_main_file, warnings, error)) {
            *out_config_main_file = g_strdup(cli_config_main_file);
            return TRUE;
        } else
            return FALSE;
    }

    /* Even though we prefer NetworkManager.conf, we need to check the
     * old nm-system-settings.conf first to preserve compat with older
     * setups.  In package managed systems dropping a NetworkManager.conf
     * onto the system would make NM use it instead of nm-system-settings.conf,
     * changing behavior during an upgrade.  We don't want that.
     */

    /* Try deprecated nm-system-settings.conf first */
    if (read_config(keyfile, TRUE, NULL, DEFAULT_CONFIG_MAIN_FILE_OLD, warnings, &my_error)) {
        *out_config_main_file = g_strdup(DEFAULT_CONFIG_MAIN_FILE_OLD);
        return TRUE;
    }

    if (!g_error_matches(my_error, G_KEY_FILE_ERROR, G_KEY_FILE_ERROR_NOT_FOUND)) {
        _LOGW("Old default config file invalid: %s", my_error->message);
    }
    g_clear_error(&my_error);

    /* Try the standard config file location next */
    if (read_config(keyfile, TRUE, NULL, DEFAULT_CONFIG_MAIN_FILE, warnings, &my_error)) {
        *out_config_main_file = g_strdup(DEFAULT_CONFIG_MAIN_FILE);
        return TRUE;
    }

    if (!g_error_matches(my_error, G_KEY_FILE_ERROR, G_KEY_FILE_ERROR_NOT_FOUND)) {
        _LOGW("Default config file invalid: %s", my_error->message);
        g_propagate_error(error, my_error);
        return FALSE;
    }
    g_clear_error(&my_error);

    /* If for some reason no config file exists, use the default
     * config file path.
     */
    *out_config_main_file = g_strdup(DEFAULT_CONFIG_MAIN_FILE);
    _LOGI("No config file found or given; using %s", DEFAULT_CONFIG_MAIN_FILE);
    return TRUE;
}

static GPtrArray *
_get_config_dir_files(const char *config_dir)
{
    GFile *          dir;
    GFileEnumerator *direnum;
    GFileInfo *      info;
    GPtrArray *      confs;
    const char *     name;

    g_return_val_if_fail(config_dir, NULL);

    confs = g_ptr_array_new_with_free_func(g_free);
    if (!*config_dir)
        return confs;

    dir     = g_file_new_for_path(config_dir);
    direnum = g_file_enumerate_children(dir, G_FILE_ATTRIBUTE_STANDARD_NAME, 0, NULL, NULL);
    if (direnum) {
        while ((info = g_file_enumerator_next_file(direnum, NULL, NULL))) {
            name = g_file_info_get_name(info);
            if (NM_STR_HAS_SUFFIX(name, ".conf"))
                g_ptr_array_add(confs, g_strdup(name));
            g_object_unref(info);
        }
        g_object_unref(direnum);
    }
    g_object_unref(dir);

    g_ptr_array_sort(confs, nm_strcmp_p);
    return confs;
}

static void
_confs_to_description(GString *str, const GPtrArray *confs, const char *name)
{
    guint i;

    if (!confs->len)
        return;

    for (i = 0; i < confs->len; i++) {
        if (i == 0)
            g_string_append_printf(str, " (%s: ", name);
        else
            g_string_append(str, ", ");
        g_string_append(str, confs->pdata[i]);
    }
    g_string_append(str, ")");
}

static GKeyFile *
read_entire_config(const NMConfigCmdLineOptions *cli,
                   const char *                  config_dir,
                   const char *                  system_config_dir,
                   char **                       out_config_main_file,
                   char **                       out_config_description,
                   GPtrArray *                   warnings,
                   GError **                     error)
{
    nm_auto_unref_keyfile GKeyFile *keyfile   = NULL;
    gs_unref_ptrarray GPtrArray *system_confs = NULL;
    gs_unref_ptrarray GPtrArray *confs        = NULL;
    gs_unref_ptrarray GPtrArray *run_confs    = NULL;
    guint                        i;
    gs_free char *               o_config_main_file = NULL;
    const char *                 run_config_dir     = "";

    nm_assert(config_dir);
    nm_assert(system_config_dir);
    nm_assert(!out_config_main_file || !*out_config_main_file);
    nm_assert(!out_config_description || !*out_config_description);
    nm_assert(!error || !*error);
    nm_assert(warnings);

    if (("" RUN_CONFIG_DIR)[0] == '/' && !nm_streq(RUN_CONFIG_DIR, system_config_dir)
        && !nm_streq(RUN_CONFIG_DIR, config_dir))
        run_config_dir = RUN_CONFIG_DIR;

    /* create a default configuration file. */
    keyfile = nm_config_create_keyfile();

    system_confs = _get_config_dir_files(system_config_dir);
    confs        = _get_config_dir_files(config_dir);
    run_confs    = _get_config_dir_files(run_config_dir);

    for (i = 0; i < system_confs->len;) {
        const char *filename = system_confs->pdata[i];

        /* if a same named file exists in config_dir or run_config_dir, skip it. */
        if (nm_utils_strv_find_first((char **) confs->pdata, confs->len, filename) >= 0
            || nm_utils_strv_find_first((char **) run_confs->pdata, run_confs->len, filename)
                   >= 0) {
            g_ptr_array_remove_index(system_confs, i);
            continue;
        }

        if (!read_config(keyfile, FALSE, system_config_dir, filename, warnings, error))
            return NULL;
        i++;
    }

    for (i = 0; i < run_confs->len;) {
        const char *filename = run_confs->pdata[i];

        /* if a same named file exists in config_dir, skip it. */
        if (nm_utils_strv_find_first((char **) confs->pdata, confs->len, filename) >= 0) {
            g_ptr_array_remove_index(run_confs, i);
            continue;
        }

        if (!read_config(keyfile, FALSE, run_config_dir, filename, warnings, error))
            return NULL;
        i++;
    }

    /* First read the base config file */
    if (!read_base_config(keyfile,
                          cli ? cli->config_main_file : NULL,
                          &o_config_main_file,
                          warnings,
                          error))
        return NULL;

    g_assert(o_config_main_file);

    for (i = 0; i < confs->len; i++) {
        if (!read_config(keyfile, FALSE, config_dir, confs->pdata[i], warnings, error))
            return NULL;
    }

    /* Merge settings from command line. They overwrite everything read from
     * config files. */

    if (cli) {
        if (cli->plugins) {
            /* plugins is a string list. Set the value directly, so the user has to do proper escaping
             * on the command line. */
            g_key_file_set_value(keyfile, NM_CONFIG_KEYFILE_GROUP_MAIN, "plugins", cli->plugins);
        }

        switch (cli->configure_and_quit) {
        case NM_CONFIG_CONFIGURE_AND_QUIT_INVALID:
            g_assert_not_reached();
            break;
        case NM_CONFIG_CONFIGURE_AND_QUIT_DISABLED:
            /* do nothing */
            break;
        case NM_CONFIG_CONFIGURE_AND_QUIT_ENABLED:
            g_key_file_set_boolean(keyfile,
                                   NM_CONFIG_KEYFILE_GROUP_MAIN,
                                   "configure-and-quit",
                                   TRUE);
            break;
        case NM_CONFIG_CONFIGURE_AND_QUIT_INITRD:
            g_key_file_set_string(keyfile,
                                  NM_CONFIG_KEYFILE_GROUP_MAIN,
                                  "configure-and-quit",
                                  "initrd");
            break;
        }

        if (cli->connectivity_uri && cli->connectivity_uri[0])
            g_key_file_set_string(keyfile,
                                  NM_CONFIG_KEYFILE_GROUP_CONNECTIVITY,
                                  "uri",
                                  cli->connectivity_uri);
        if (cli->connectivity_interval >= 0)
            g_key_file_set_integer(keyfile,
                                   NM_CONFIG_KEYFILE_GROUP_CONNECTIVITY,
                                   "interval",
                                   cli->connectivity_interval);
        if (cli->connectivity_response && cli->connectivity_response[0])
            g_key_file_set_string(keyfile,
                                  NM_CONFIG_KEYFILE_GROUP_CONNECTIVITY,
                                  "response",
                                  cli->connectivity_response);
    }

    if (out_config_description) {
        GString *str;

        str = g_string_new(o_config_main_file);
        _confs_to_description(str, system_confs, "lib");
        _confs_to_description(str, run_confs, "run");
        _confs_to_description(str, confs, "etc");
        *out_config_description = g_string_free(str, FALSE);
    }
    NM_SET_OUT(out_config_main_file, g_steal_pointer(&o_config_main_file));

    return g_steal_pointer(&keyfile);
}

static gboolean
_is_atomic_section(const char *const *atomic_section_prefixes, const char *group)
{
    if (atomic_section_prefixes) {
        for (; *atomic_section_prefixes; atomic_section_prefixes++) {
            if (**atomic_section_prefixes && g_str_has_prefix(group, *atomic_section_prefixes))
                return TRUE;
        }
    }
    return FALSE;
}

static void
_string_append_val(GString *str, const char *value)
{
    if (!value)
        return;
    g_string_append_c(str, '+');
    while (TRUE) {
        switch (*value) {
        case '\0':
            return;
        case '\\':
        case '+':
        case '#':
        case ':':
            g_string_append_c(str, '+');
            /* fall-through */
        default:
            g_string_append_c(str, *value);
        }
        value++;
    }
}

static char *
_keyfile_serialize_section(GKeyFile *keyfile, const char *group)
{
    gs_strfreev char **keys = NULL;
    GString *          str;
    guint              k;

    if (keyfile)
        keys = g_key_file_get_keys(keyfile, group, NULL, NULL);
    if (!keys)
        return g_strdup("0#");

    /* prepend a version. */
    str = g_string_new("1#");

    for (k = 0; keys[k]; k++) {
        const char *  key   = keys[k];
        gs_free char *value = NULL;

        _string_append_val(str, key);
        g_string_append_c(str, ':');

        value = g_key_file_get_value(keyfile, group, key, NULL);
        _string_append_val(str, value);
        g_string_append_c(str, '#');
    }
    return g_string_free(str, FALSE);
}

gboolean
nm_config_keyfile_has_global_dns_config(GKeyFile *keyfile, gboolean internal)
{
    gs_strfreev char **groups = NULL;
    guint              g;
    const char *       prefix;

    if (!keyfile)
        return FALSE;
    if (g_key_file_has_group(keyfile,
                             internal ? NM_CONFIG_KEYFILE_GROUP_GLOBAL_DNS
                                      : NM_CONFIG_KEYFILE_GROUP_INTERN_GLOBAL_DNS))
        return TRUE;

    groups = g_key_file_get_groups(keyfile, NULL);
    if (!groups)
        return FALSE;

    prefix = internal ? NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN_GLOBAL_DNS_DOMAIN
                      : NM_CONFIG_KEYFILE_GROUPPREFIX_GLOBAL_DNS_DOMAIN;

    for (g = 0; groups[g]; g++) {
        if (g_str_has_prefix(groups[g], prefix))
            return TRUE;
    }
    return FALSE;
}

/**
 * intern_config_read:
 * @filename: the filename where to store the internal config
 * @keyfile_conf: the merged configuration from user (/etc/NM/NetworkManager.conf).
 * @out_needs_rewrite: (allow-none): whether the read keyfile contains inconsistent
 *   data (compared to @keyfile_conf). If %TRUE, you might want to rewrite
 *   the file.
 *
 * Does the opposite of intern_config_write(). It reads the internal configuration.
 * Note that the actual format of how the configuration is saved in @filename
 * is different then what we return here. NMConfig manages what is written internally
 * by having it inside a keyfile_intern. But we don't write that to disk as is.
 * Especially, we also store parts of @keyfile_conf as ".was" and on read we compare
 * what we have, with what ".was".
 *
 * Returns: a #GKeyFile instance with the internal configuration.
 */
static GKeyFile *
intern_config_read(const char *       filename,
                   GKeyFile *         keyfile_conf,
                   const char *const *atomic_section_prefixes,
                   gboolean *         out_needs_rewrite)
{
    GKeyFile *         keyfile_intern;
    GKeyFile *         keyfile;
    gboolean           needs_rewrite = FALSE;
    gs_strfreev char **groups        = NULL;
    guint              g, k;
    gboolean           has_intern = FALSE;

    g_return_val_if_fail(filename, NULL);

    if (!*filename) {
        if (out_needs_rewrite)
            *out_needs_rewrite = FALSE;
        return NULL;
    }

    keyfile_intern = nm_config_create_keyfile();

    keyfile = nm_config_create_keyfile();
    if (!g_key_file_load_from_file(keyfile, filename, G_KEY_FILE_NONE, NULL)) {
        needs_rewrite = TRUE;
        goto out;
    }

    groups = g_key_file_get_groups(keyfile, NULL);
    for (g = 0; groups && groups[g]; g++) {
        gs_strfreev char **keys  = NULL;
        const char *       group = groups[g];
        gboolean           is_intern, is_atomic;

        if (nm_streq(group, NM_CONFIG_KEYFILE_GROUP_CONFIG))
            continue;

        keys = g_key_file_get_keys(keyfile, group, NULL, NULL);
        if (!keys)
            continue;

        is_intern = NM_STR_HAS_PREFIX(group, NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN);
        is_atomic = !is_intern && _is_atomic_section(atomic_section_prefixes, group);

        if (is_atomic) {
            gs_free char *conf_section_was = NULL;
            gs_free char *conf_section_is  = NULL;

            conf_section_is  = _keyfile_serialize_section(keyfile_conf, group);
            conf_section_was = g_key_file_get_string(keyfile,
                                                     group,
                                                     NM_CONFIG_KEYFILE_KEY_ATOMIC_SECTION_WAS,
                                                     NULL);

            if (!nm_streq0(conf_section_was, conf_section_is)) {
                /* the section no longer matches. Skip it entirely. */
                needs_rewrite = TRUE;
                continue;
            }
            /* we must set the "was" marker in our keyfile, so that we know that the section
             * from user config is overwritten. The value doesn't matter, it's just a marker
             * that this section is present. */
            g_key_file_set_value(keyfile_intern,
                                 group,
                                 NM_CONFIG_KEYFILE_KEY_ATOMIC_SECTION_WAS,
                                 "");
        }

        for (k = 0; keys[k]; k++) {
            gs_free char *value_set = NULL;
            const char *  key       = keys[k];

            value_set = g_key_file_get_value(keyfile, group, key, NULL);

            if (is_intern) {
                has_intern = TRUE;
                g_key_file_set_value(keyfile_intern, group, key, value_set);
            } else if (is_atomic) {
                if (nm_streq(key, NM_CONFIG_KEYFILE_KEY_ATOMIC_SECTION_WAS))
                    continue;
                g_key_file_set_value(keyfile_intern, group, key, value_set);
            } else if (NM_STR_HAS_PREFIX_WITH_MORE(key, NM_CONFIG_KEYFILE_KEYPREFIX_SET)) {
                const char *  key_base   = &key[NM_STRLEN(NM_CONFIG_KEYFILE_KEYPREFIX_SET)];
                gs_free char *value_was  = NULL;
                gs_free char *value_conf = NULL;
                gs_free char *key_was =
                    g_strdup_printf(NM_CONFIG_KEYFILE_KEYPREFIX_WAS "%s", key_base);

                if (keyfile_conf)
                    value_conf = g_key_file_get_value(keyfile_conf, group, key_base, NULL);
                value_was = g_key_file_get_value(keyfile, group, key_was, NULL);

                if (!nm_streq0(value_conf, value_was)) {
                    /* if value_was is no longer the same as @value_conf, it means the user
                     * changed the configuration since the last write. In this case, we
                     * drop the value. It also means our file is out-of-date, and we should
                     * rewrite it. */
                    needs_rewrite = TRUE;
                    continue;
                }
                has_intern = TRUE;
                g_key_file_set_value(keyfile_intern, group, key_base, value_set);
            } else if (NM_STR_HAS_PREFIX_WITH_MORE(key, NM_CONFIG_KEYFILE_KEYPREFIX_WAS)) {
                const char *  key_base = &key[NM_STRLEN(NM_CONFIG_KEYFILE_KEYPREFIX_WAS)];
                gs_free char *key_set =
                    g_strdup_printf(NM_CONFIG_KEYFILE_KEYPREFIX_SET "%s", key_base);
                gs_free char *value_was  = NULL;
                gs_free char *value_conf = NULL;

                if (g_key_file_has_key(keyfile, group, key_set, NULL)) {
                    /* we have a matching "set" key too. Handle the "was" key there. */
                    continue;
                }

                if (keyfile_conf)
                    value_conf = g_key_file_get_value(keyfile_conf, group, key_base, NULL);
                value_was = g_key_file_get_value(keyfile, group, key, NULL);

                if (!nm_streq0(value_conf, value_was)) {
                    /* if value_was is no longer the same as @value_conf, it means the user
                     * changed the configuration since the last write. In this case, we
                     * don't overwrite the user-provided value. It also means our file is
                     * out-of-date, and we should rewrite it. */
                    needs_rewrite = TRUE;
                    continue;
                }
                has_intern = TRUE;
                /* signal the absence of the value. That means, we must propagate the
                 * "was" key to NMConfigData, so that it knows to hide the corresponding
                 * user key. */
                g_key_file_set_value(keyfile_intern, group, key, "");
            } else
                needs_rewrite = TRUE;
        }
    }

out:
    /*
     * If user configuration specifies global DNS options, the DNS
     * options in internal configuration must be deleted. Otherwise, a
     * deletion of options from user configuration may cause the
     * internal options to appear again.
     */
    if (nm_config_keyfile_has_global_dns_config(keyfile_conf, FALSE)) {
        if (g_key_file_remove_group(keyfile_intern,
                                    NM_CONFIG_KEYFILE_GROUP_INTERN_GLOBAL_DNS,
                                    NULL))
            needs_rewrite = TRUE;
        for (g = 0; groups && groups[g]; g++) {
            if (NM_STR_HAS_PREFIX(groups[g], NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN_GLOBAL_DNS_DOMAIN)
                && groups[g][NM_STRLEN(NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN_GLOBAL_DNS_DOMAIN)]) {
                g_key_file_remove_group(keyfile_intern, groups[g], NULL);
                needs_rewrite = TRUE;
            }
        }
    }

    g_key_file_unref(keyfile);

    if (out_needs_rewrite)
        *out_needs_rewrite = needs_rewrite;

    _LOGD("intern config file \"%s\"", filename);

    if (!has_intern) {
        g_key_file_unref(keyfile_intern);
        return NULL;
    }
    return keyfile_intern;
}

static int
_intern_config_write_sort_fcn(const char **      a,
                              const char **      b,
                              const char *const *atomic_section_prefixes)
{
    const char *g_a = *a;
    const char *g_b = *b;
    gboolean    a_is, b_is;

    a_is = NM_STR_HAS_PREFIX(g_a, NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN);
    b_is = NM_STR_HAS_PREFIX(g_b, NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN);

    if (a_is != b_is) {
        if (a_is)
            return 1;
        return -1;
    }
    if (!a_is) {
        a_is = _is_atomic_section(atomic_section_prefixes, g_a);
        b_is = _is_atomic_section(atomic_section_prefixes, g_b);

        if (a_is != b_is) {
            if (a_is)
                return 1;
            return -1;
        }
    }
    return g_strcmp0(g_a, g_b);
}

static gboolean
intern_config_write(const char *       filename,
                    GKeyFile *         keyfile_intern,
                    GKeyFile *         keyfile_conf,
                    const char *const *atomic_section_prefixes,
                    GError **          error)
{
    GKeyFile *         keyfile;
    gs_strfreev char **groups = NULL;
    guint              g, k;
    gboolean           success = FALSE;
    GError *           local   = NULL;

    g_return_val_if_fail(filename, FALSE);

    if (!*filename) {
        g_set_error(error,
                    G_KEY_FILE_ERROR,
                    G_KEY_FILE_ERROR_NOT_FOUND,
                    "no filename to write (use --intern-config?)");
        return FALSE;
    }

    keyfile = nm_config_create_keyfile();

    if (keyfile_intern) {
        groups = g_key_file_get_groups(keyfile_intern, NULL);
        if (groups && groups[0]) {
            g_qsort_with_data(groups,
                              g_strv_length(groups),
                              sizeof(char *),
                              (GCompareDataFunc) _intern_config_write_sort_fcn,
                              (gpointer) atomic_section_prefixes);
        }
    }
    for (g = 0; groups && groups[g]; g++) {
        gs_strfreev char **keys  = NULL;
        const char *       group = groups[g];
        gboolean           is_intern, is_atomic;

        keys = g_key_file_get_keys(keyfile_intern, group, NULL, NULL);
        if (!keys)
            continue;

        is_intern = NM_STR_HAS_PREFIX(group, NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN);
        is_atomic = !is_intern && _is_atomic_section(atomic_section_prefixes, group);

        if (is_atomic) {
            if ((!keys[0]
                 || (!keys[1] && strcmp(keys[0], NM_CONFIG_KEYFILE_KEY_ATOMIC_SECTION_WAS) == 0))
                && !g_key_file_has_group(keyfile_conf, group)) {
                /* we are about to save an atomic section. However, we don't have any additional
                 * keys on our own and there is no user-provided (overlapping) section either.
                 * We don't have to write an empty section (i.e. skip the useless ".was=0#"). */
                continue;
            } else {
                gs_free char *conf_section_is = NULL;

                conf_section_is = _keyfile_serialize_section(keyfile_conf, group);
                g_key_file_set_string(keyfile,
                                      group,
                                      NM_CONFIG_KEYFILE_KEY_ATOMIC_SECTION_WAS,
                                      conf_section_is);
                g_key_file_set_comment(keyfile,
                                       group,
                                       NULL,
                                       " Overwrites entire section from 'NetworkManager.conf'",
                                       NULL);
            }
        }

        for (k = 0; keys[k]; k++) {
            const char *  key       = keys[k];
            gs_free char *value_set = NULL;
            gs_free char *key_set   = NULL;

            if (!is_intern && strcmp(key, NM_CONFIG_KEYFILE_KEY_ATOMIC_SECTION_WAS) == 0) {
                g_warn_if_fail(is_atomic);
                continue;
            }

            value_set = g_key_file_get_value(keyfile_intern, group, key, NULL);

            if (is_intern || is_atomic)
                g_key_file_set_value(keyfile, group, key, value_set);
            else {
                gs_free char *value_was = NULL;

                if (NM_STR_HAS_PREFIX_WITH_MORE(key, NM_CONFIG_KEYFILE_KEYPREFIX_SET)) {
                    /* Setting a key with .set prefix has no meaning, as these keys
                     * are protected. Just set the value you want to set instead.
                     * Why did this happen?? */
                    g_warn_if_reached();
                } else if (NM_STR_HAS_PREFIX_WITH_MORE(key, NM_CONFIG_KEYFILE_KEYPREFIX_WAS)) {
                    const char *key_base = &key[NM_STRLEN(NM_CONFIG_KEYFILE_KEYPREFIX_WAS)];

                    if (NM_STR_HAS_PREFIX_WITH_MORE(key_base, NM_CONFIG_KEYFILE_KEYPREFIX_SET)
                        || NM_STR_HAS_PREFIX_WITH_MORE(key_base, NM_CONFIG_KEYFILE_KEYPREFIX_WAS)) {
                        g_warn_if_reached();
                        continue;
                    }

                    if (g_key_file_has_key(keyfile_intern, group, key_base, NULL)) {
                        /* There is also a matching key_base entry. Skip processing
                         * the .was. key ad handle the key_base in the other else branch. */
                        continue;
                    }

                    if (keyfile_conf) {
                        value_was = g_key_file_get_value(keyfile_conf, group, key_base, NULL);
                        if (value_was)
                            g_key_file_set_value(keyfile, group, key, value_was);
                    }
                } else {
                    if (keyfile_conf) {
                        value_was = g_key_file_get_value(keyfile_conf, group, key, NULL);
                        if (nm_streq0(value_set, value_was)) {
                            /* there is no point in storing the identical value as we have via
                             * user configuration. Skip it. */
                            continue;
                        }
                        if (value_was) {
                            gs_free char *key_was = NULL;

                            key_was = g_strdup_printf(NM_CONFIG_KEYFILE_KEYPREFIX_WAS "%s", key);
                            g_key_file_set_value(keyfile, group, key_was, value_was);
                        }
                    }
                    key = key_set = g_strdup_printf(NM_CONFIG_KEYFILE_KEYPREFIX_SET "%s", key);
                    g_key_file_set_value(keyfile, group, key, value_set);
                }
            }
        }
        if (is_intern && g_key_file_has_group(keyfile, group)) {
            g_key_file_set_comment(keyfile,
                                   group,
                                   NULL,
                                   " Internal section. Not overwritable via user configuration in "
                                   "'NetworkManager.conf'",
                                   NULL);
        }
    }

    g_key_file_set_comment(
        keyfile,
        NULL,
        NULL,
        " Internal configuration file. This file is written and read\n"
        " by NetworkManager and its configuration values are merged\n"
        " with the configuration from 'NetworkManager.conf'.\n"
        "\n"
        " Keys with a \"" NM_CONFIG_KEYFILE_KEYPREFIX_SET "\" prefix specify the value to set.\n"
        " A corresponding key with a \"" NM_CONFIG_KEYFILE_KEYPREFIX_WAS
        "\" prefix records the value\n"
        " of the user configuration at the time of storing the file.\n"
        " The value from internal configuration is rejected if the corresponding\n"
        " \"" NM_CONFIG_KEYFILE_KEYPREFIX_WAS
        "\" key no longer matches the configuration from 'NetworkManager.conf'.\n"
        " That means, if you modify a value in 'NetworkManager.conf', the internal\n"
        " overwrite no longer matches and is ignored.\n"
        "\n"
        " Certain sections can only be overwritten whole, not on a per key basis.\n"
        " Such sections are marked with a \"" NM_CONFIG_KEYFILE_KEY_ATOMIC_SECTION_WAS
        "\" key that records the user configuration\n"
        " at the time of writing.\n"
        "\n"
        " Internal sections of the form [" NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN "*] cannot\n"
        " be set by user configuration.\n"
        "\n"
        " CHANGES TO THIS FILE WILL BE OVERWRITTEN",
        NULL);

    success = g_key_file_save_to_file(keyfile, filename, &local);

    _LOGD("write intern config file \"%s\"%s%s",
          filename,
          success ? "" : ": ",
          success ? "" : local->message);
    g_key_file_unref(keyfile);
    if (!success)
        g_propagate_error(error, local);
    return success;
}

/*****************************************************************************/

GSList *
nm_config_get_match_spec(const GKeyFile *keyfile,
                         const char *    group,
                         const char *    key,
                         gboolean *      out_has_key)
{
    gs_free char *value = NULL;

    /* nm_match_spec_split() already supports full escaping and is basically
     * a modified version of g_key_file_parse_value_as_string(). So we first read
     * the raw value (g_key_file_get_value()), and do the parsing ourselves. */
    value = g_key_file_get_value((GKeyFile *) keyfile, group, key, NULL);
    if (out_has_key)
        *out_has_key = !!value;
    return nm_match_spec_split(value);
}

/*****************************************************************************/

gboolean
nm_config_set_global_dns(NMConfig *self, NMGlobalDnsConfig *global_dns, GError **error)
{
    NMConfigPrivate *        priv;
    GKeyFile *               keyfile;
    char **                  groups;
    const NMGlobalDnsConfig *old_global_dns;
    guint                    i;

    g_return_val_if_fail(NM_IS_CONFIG(self), FALSE);

    priv = NM_CONFIG_GET_PRIVATE(self);
    g_return_val_if_fail(priv->config_data, FALSE);

    old_global_dns = nm_config_data_get_global_dns_config(priv->config_data);
    if (old_global_dns && !nm_global_dns_config_is_internal(old_global_dns)) {
        g_set_error_literal(error,
                            1,
                            0,
                            "Global DNS configuration already set via configuration file");
        return FALSE;
    }

    keyfile = nm_config_data_clone_keyfile_intern(priv->config_data);

    /* Remove existing groups */
    g_key_file_remove_group(keyfile, NM_CONFIG_KEYFILE_GROUP_INTERN_GLOBAL_DNS, NULL);
    groups = g_key_file_get_groups(keyfile, NULL);
    for (i = 0; groups[i]; i++) {
        if (NM_STR_HAS_PREFIX(groups[i], NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN_GLOBAL_DNS_DOMAIN))
            g_key_file_remove_group(keyfile, groups[i], NULL);
    }
    g_strfreev(groups);

    /* An empty configuration removes everything from internal configuration file */
    if (nm_global_dns_config_is_empty(global_dns))
        goto done;

    /* Set new values */
    nm_config_keyfile_set_string_list(keyfile,
                                      NM_CONFIG_KEYFILE_GROUP_INTERN_GLOBAL_DNS,
                                      NM_CONFIG_KEYFILE_KEY_GLOBAL_DNS_SEARCHES,
                                      nm_global_dns_config_get_searches(global_dns),
                                      -1);

    nm_config_keyfile_set_string_list(keyfile,
                                      NM_CONFIG_KEYFILE_GROUP_INTERN_GLOBAL_DNS,
                                      NM_CONFIG_KEYFILE_KEY_GLOBAL_DNS_OPTIONS,
                                      nm_global_dns_config_get_options(global_dns),
                                      -1);

    for (i = 0; i < nm_global_dns_config_get_num_domains(global_dns); i++) {
        NMGlobalDnsDomain *domain     = nm_global_dns_config_get_domain(global_dns, i);
        gs_free char *     group_name = NULL;

        group_name = g_strdup_printf(NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN_GLOBAL_DNS_DOMAIN "%s",
                                     nm_global_dns_domain_get_name(domain));

        nm_config_keyfile_set_string_list(keyfile,
                                          group_name,
                                          NM_CONFIG_KEYFILE_KEY_GLOBAL_DNS_DOMAIN_SERVERS,
                                          nm_global_dns_domain_get_servers(domain),
                                          -1);
        nm_config_keyfile_set_string_list(keyfile,
                                          group_name,
                                          NM_CONFIG_KEYFILE_KEY_GLOBAL_DNS_DOMAIN_OPTIONS,
                                          nm_global_dns_domain_get_options(domain),
                                          -1);
    }

done:
    nm_config_set_values(self, keyfile, TRUE, FALSE);
    g_key_file_unref(keyfile);

    return TRUE;
}

/*****************************************************************************/

void
nm_config_set_connectivity_check_enabled(NMConfig *self, gboolean enabled)
{
    NMConfigPrivate *priv;
    GKeyFile *       keyfile;

    g_return_if_fail(NM_IS_CONFIG(self));

    priv = NM_CONFIG_GET_PRIVATE(self);
    g_return_if_fail(priv->config_data);

    keyfile = nm_config_data_clone_keyfile_intern(priv->config_data);

    /* Remove existing groups */
    g_key_file_remove_group(keyfile, NM_CONFIG_KEYFILE_GROUP_CONNECTIVITY, NULL);

    g_key_file_set_value(keyfile,
                         NM_CONFIG_KEYFILE_GROUP_CONNECTIVITY,
                         "enabled",
                         enabled ? "true" : "false");

    nm_config_set_values(self, keyfile, TRUE, FALSE);
    g_key_file_unref(keyfile);
}

/**
 * nm_config_set_values:
 * @self: the NMConfig instance
 * @keyfile_intern_new: (allow-none): the new internal settings to set.
 *   If %NULL, it is equal to an empty keyfile.
 * @allow_write: only if %TRUE, allow writing the changes to file. Otherwise,
 *   do the changes in-memory only.
 * @force_rewrite: if @allow_write is %FALSE, this has no effect. If %FALSE,
 *   only write the configuration to file, if there are any actual changes.
 *   If %TRUE, always write the configuration to file, even if tere are seemingly
 *   no changes.
 *
 *  This is the most flexible function to set values. It all depends on the
 *  keys and values you set in @keyfile_intern_new. You basically reset all
 *  internal configuration values to what is in @keyfile_intern_new.
 *
 *  There are 3 types of settings:
 *    - all groups/sections with a prefix [.intern.*] are taken as is. As these
 *      groups are separate from user configuration, there is no conflict. You set
 *      them, that's it.
 *    - there are atomic sections, i.e. sections whose name start with one of
 *      NM_CONFIG_ATOMIC_SECTION_PREFIXES. If you put values in these sections,
 *      it means you completely replace the section from user configuration.
 *      You can also hide a user provided section by only putting the special
 *      key NM_CONFIG_KEYFILE_KEY_ATOMIC_SECTION_WAS into that section.
 *    - otherwise you can overwrite individual values from user-configuration.
 *      Just set the value. Keys with a prefix NM_CONFIG_KEYFILE_KEYPREFIX_*
 *      are protected -- as they are not value user keys.
 *      You can also hide a certain user setting by putting only a key
 *      NM_CONFIG_KEYFILE_KEYPREFIX_WAS"keyname" into the keyfile.
 */
void
nm_config_set_values(NMConfig *self,
                     GKeyFile *keyfile_intern_new,
                     gboolean  allow_write,
                     gboolean  force_rewrite)
{
    NMConfigPrivate *  priv;
    GKeyFile *         keyfile_intern_current;
    GKeyFile *         keyfile_user;
    GKeyFile *         keyfile_new;
    GError *           local    = NULL;
    NMConfigData *     new_data = NULL;
    gs_strfreev char **groups   = NULL;
    int                g;

    g_return_if_fail(NM_IS_CONFIG(self));

    priv = NM_CONFIG_GET_PRIVATE(self);

    keyfile_intern_current = _nm_config_data_get_keyfile_intern(priv->config_data);

    keyfile_new = nm_config_create_keyfile();
    if (keyfile_intern_new)
        _nm_keyfile_copy(keyfile_new, keyfile_intern_new);

    /* ensure that every atomic section has a .was entry. */
    groups = g_key_file_get_groups(keyfile_new, NULL);
    for (g = 0; groups && groups[g]; g++) {
        if (_is_atomic_section((const char *const *) priv->atomic_section_prefixes, groups[g]))
            g_key_file_set_value(keyfile_new,
                                 groups[g],
                                 NM_CONFIG_KEYFILE_KEY_ATOMIC_SECTION_WAS,
                                 "");
    }

    if (!_nm_keyfile_equal(keyfile_intern_current, keyfile_new, TRUE))
        new_data = nm_config_data_new_update_keyfile_intern(priv->config_data, keyfile_new);

    _LOGD("set values(): %s", new_data ? "has changes" : "no changes");

    if (allow_write && (new_data || force_rewrite)) {
        /* We write the internal config file based on the user configuration from
         * the last load/reload. That is correct, because the intern properties might
         * be in accordance to what NM thinks is currently configured. Even if the files
         * on disk changed in the meantime.
         * But if they changed, on the next reload with might throw away our just
         * written data. That is correct, because from NM's point of view, those
         * changes on disk happened in any case *after* now. */
        if (*priv->intern_config_file) {
            keyfile_user = _nm_config_data_get_keyfile_user(priv->config_data);
            if (!intern_config_write(priv->intern_config_file,
                                     keyfile_new,
                                     keyfile_user,
                                     (const char *const *) priv->atomic_section_prefixes,
                                     &local)) {
                _LOGW("error saving internal configuration \"%s\": %s",
                      priv->intern_config_file,
                      local->message);
                g_clear_error(&local);
            }
        } else
            _LOGD("don't persist internal configuration (no file set, use --intern-config?)");
    }
    if (new_data)
        _set_config_data(self, new_data, NM_CONFIG_CHANGE_CAUSE_SET_VALUES);

    g_key_file_unref(keyfile_new);
}

/******************************************************************************
 * State
 ******************************************************************************/

static const char *
state_get_filename(const NMConfigCmdLineOptions *cli)
{
    /* For an empty filename, we assume the user wants to disable
     * state. NMConfig will not try to read it nor write it out. */
    if (!cli->state_file)
        return DEFAULT_STATE_FILE;
    return cli->state_file[0] ? cli->state_file : NULL;
}

static State *
state_new(void)
{
    State *state;

    state                 = g_slice_new0(State);
    state->p.net_enabled  = TRUE;
    state->p.wifi_enabled = TRUE;
    state->p.wwan_enabled = TRUE;

    return state;
}

static void
state_free(State *state)
{
    if (!state)
        return;
    g_slice_free(State, state);
}

static State *
state_new_from_file(const char *filename)
{
    GKeyFile *    keyfile;
    gs_free_error GError *error = NULL;
    State *               state;

    state = state_new();

    if (!filename)
        return state;

    keyfile = g_key_file_new();
    g_key_file_set_list_separator(keyfile, ',');
    if (!g_key_file_load_from_file(keyfile, filename, G_KEY_FILE_NONE, &error)) {
        if (g_error_matches(error, G_FILE_ERROR, G_FILE_ERROR_NOENT))
            _LOGD("state: missing state file \"%s\": %s", filename, error->message);
        else
            _LOGW("state: error reading state file \"%s\": %s", filename, error->message);
        goto out;
    }

    _LOGD("state: successfully read state file \"%s\"", filename);

    state->p.net_enabled =
        nm_config_keyfile_get_boolean(keyfile, "main", "NetworkingEnabled", state->p.net_enabled);
    state->p.wifi_enabled =
        nm_config_keyfile_get_boolean(keyfile, "main", "WirelessEnabled", state->p.wifi_enabled);
    state->p.wwan_enabled =
        nm_config_keyfile_get_boolean(keyfile, "main", "WWANEnabled", state->p.wwan_enabled);

out:
    g_key_file_unref(keyfile);
    return state;
}

const NMConfigState *
nm_config_state_get(NMConfig *self)
{
    NMConfigPrivate *priv;

    g_return_val_if_fail(NM_IS_CONFIG(self), NULL);

    priv = NM_CONFIG_GET_PRIVATE(self);

    if (G_UNLIKELY(!priv->state)) {
        /* read the state from file lazy on first access. The reason is that
         * we want to log a failure to read the file via nm-logging.
         *
         * So we cannot read the state during construction of NMConfig,
         * because at that time nm-logging is not yet configured.
         */
        priv->state = state_new_from_file(state_get_filename(&priv->cli));
    }

    return &priv->state->p;
}

static void
state_write(NMConfig *self)
{
    NMConfigPrivate *priv = NM_CONFIG_GET_PRIVATE(self);
    const char *     filename;
    GString *        str;
    GError *         error = NULL;

    if (priv->configure_and_quit != NM_CONFIG_CONFIGURE_AND_QUIT_DISABLED)
        return;

    filename = state_get_filename(&priv->cli);

    if (!filename) {
        priv->state->p.dirty = FALSE;
        return;
    }

    str = g_string_sized_new(256);

    /* Let's construct the keyfile data by hand. */

    g_string_append(str, "[main]\n");
    g_string_append_printf(str,
                           "NetworkingEnabled=%s\n",
                           priv->state->p.net_enabled ? "true" : "false");
    g_string_append_printf(str,
                           "WirelessEnabled=%s\n",
                           priv->state->p.wifi_enabled ? "true" : "false");
    g_string_append_printf(str, "WWANEnabled=%s\n", priv->state->p.wwan_enabled ? "true" : "false");

    if (!g_file_set_contents(filename, str->str, str->len, &error)) {
        _LOGD("state: error writing state file \"%s\": %s", filename, error->message);
        g_clear_error(&error);
        /* we leave the state dirty. That potentially means, that we try to
         * write the file over and over again, although it isn't possible. */
        priv->state->p.dirty = TRUE;
    } else
        priv->state->p.dirty = FALSE;

    _LOGT("state: success writing state file \"%s\"", filename);

    g_string_free(str, TRUE);
}

void
_nm_config_state_set(NMConfig *self, gboolean allow_persist, gboolean force_persist, ...)
{
    NMConfigPrivate *            priv;
    va_list                      ap;
    NMConfigRunStatePropertyType property_type;

    g_return_if_fail(NM_IS_CONFIG(self));

    priv = NM_CONFIG_GET_PRIVATE(self);

    va_start(ap, force_persist);

    /* We expect that the NMConfigRunStatePropertyType is an integer type <= sizeof (int).
     * Smaller would be fine, since the variadic arguments get promoted to int.
     * Larger would be a problem, also, because we want that "0" is a valid sentinel. */
    G_STATIC_ASSERT_EXPR(sizeof(NMConfigRunStatePropertyType) <= sizeof(int));

    while ((property_type = va_arg(ap, int)) != NM_CONFIG_STATE_PROPERTY_NONE) {
        bool *p_bool, v_bool;

        switch (property_type) {
        case NM_CONFIG_STATE_PROPERTY_NETWORKING_ENABLED:
            p_bool = &priv->state->p.net_enabled;
            break;
        case NM_CONFIG_STATE_PROPERTY_WIFI_ENABLED:
            p_bool = &priv->state->p.wifi_enabled;
            break;
        case NM_CONFIG_STATE_PROPERTY_WWAN_ENABLED:
            p_bool = &priv->state->p.wwan_enabled;
            break;
        default:
            va_end(ap);
            g_return_if_reached();
        }

        v_bool = va_arg(ap, gboolean);
        if (*p_bool == v_bool)
            continue;
        *p_bool              = v_bool;
        priv->state->p.dirty = TRUE;
    }

    va_end(ap);

    if (allow_persist && (force_persist || priv->state->p.dirty))
        state_write(self);
}

/*****************************************************************************/

#define DEVICE_RUN_STATE_KEYFILE_GROUP_DEVICE                 "device"
#define DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_MANAGED           "managed"
#define DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_PERM_HW_ADDR_FAKE "perm-hw-addr-fake"
#define DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_CONNECTION_UUID   "connection-uuid"
#define DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_NM_OWNED          "nm-owned"
#define DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_ROUTE_METRIC_DEFAULT_ASPIRED \
    "route-metric-default-aspired"
#define DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_ROUTE_METRIC_DEFAULT_EFFECTIVE \
    "route-metric-default-effective"
#define DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_ROOT_PATH     "root-path"
#define DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_NEXT_SERVER   "next-server"
#define DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_DHCP_BOOTFILE "dhcp-bootfile"

static NM_UTILS_LOOKUP_STR_DEFINE(
    _device_state_managed_type_to_str,
    NMConfigDeviceStateManagedType,
    NM_UTILS_LOOKUP_DEFAULT_NM_ASSERT("unknown"),
    NM_UTILS_LOOKUP_STR_ITEM(NM_CONFIG_DEVICE_STATE_MANAGED_TYPE_UNKNOWN, "unknown"),
    NM_UTILS_LOOKUP_STR_ITEM(NM_CONFIG_DEVICE_STATE_MANAGED_TYPE_UNMANAGED, "unmanaged"),
    NM_UTILS_LOOKUP_STR_ITEM(NM_CONFIG_DEVICE_STATE_MANAGED_TYPE_MANAGED, "managed"), );

static NMConfigDeviceStateData *
_config_device_state_data_new(int ifindex, GKeyFile *kf)
{
    NMConfigDeviceStateData *      device_state;
    NMConfigDeviceStateManagedType managed_type      = NM_CONFIG_DEVICE_STATE_MANAGED_TYPE_UNKNOWN;
    gs_free char *                 connection_uuid   = NULL;
    gs_free char *                 perm_hw_addr_fake = NULL;
    gsize                          connection_uuid_len;
    gsize                          perm_hw_addr_fake_len;
    NMTernary                      nm_owned;
    char *                         p;
    guint32                        route_metric_default_effective;
    guint32                        route_metric_default_aspired;

    nm_assert(kf);
    nm_assert(ifindex > 0);

    switch (nm_config_keyfile_get_boolean(kf,
                                          DEVICE_RUN_STATE_KEYFILE_GROUP_DEVICE,
                                          DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_MANAGED,
                                          -1)) {
    case TRUE:
        managed_type = NM_CONFIG_DEVICE_STATE_MANAGED_TYPE_MANAGED;
        connection_uuid =
            nm_config_keyfile_get_value(kf,
                                        DEVICE_RUN_STATE_KEYFILE_GROUP_DEVICE,
                                        DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_CONNECTION_UUID,
                                        NM_CONFIG_GET_VALUE_STRIP | NM_CONFIG_GET_VALUE_NO_EMPTY);
        break;
    case FALSE:
        managed_type = NM_CONFIG_DEVICE_STATE_MANAGED_TYPE_UNMANAGED;
        break;
    case -1:
        /* missing property in keyfile. */
        break;
    }

    perm_hw_addr_fake =
        nm_config_keyfile_get_value(kf,
                                    DEVICE_RUN_STATE_KEYFILE_GROUP_DEVICE,
                                    DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_PERM_HW_ADDR_FAKE,
                                    NM_CONFIG_GET_VALUE_STRIP | NM_CONFIG_GET_VALUE_NO_EMPTY);
    if (perm_hw_addr_fake) {
        char *normalized;

        normalized = nm_utils_hwaddr_canonical(perm_hw_addr_fake, -1);
        g_free(perm_hw_addr_fake);
        perm_hw_addr_fake = normalized;
    }

    nm_owned = nm_config_keyfile_get_boolean(kf,
                                             DEVICE_RUN_STATE_KEYFILE_GROUP_DEVICE,
                                             DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_NM_OWNED,
                                             NM_TERNARY_DEFAULT);

    /* metric zero is not a valid metric. While zero valid for IPv4, for IPv6 it is an alias
     * for 1024. Since we handle here IPv4 and IPv6 the same, we cannot allow zero. */
    route_metric_default_effective = nm_config_keyfile_get_int64(
        kf,
        DEVICE_RUN_STATE_KEYFILE_GROUP_DEVICE,
        DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_ROUTE_METRIC_DEFAULT_EFFECTIVE,
        10,
        1,
        G_MAXUINT32,
        0);
    if (route_metric_default_effective) {
        route_metric_default_aspired = nm_config_keyfile_get_int64(
            kf,
            DEVICE_RUN_STATE_KEYFILE_GROUP_DEVICE,
            DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_ROUTE_METRIC_DEFAULT_EFFECTIVE,
            10,
            1,
            route_metric_default_effective,
            route_metric_default_effective);
    } else
        route_metric_default_aspired = 0;

    connection_uuid_len   = connection_uuid ? strlen(connection_uuid) + 1 : 0;
    perm_hw_addr_fake_len = perm_hw_addr_fake ? strlen(perm_hw_addr_fake) + 1 : 0;

    device_state =
        g_malloc(sizeof(NMConfigDeviceStateData) + connection_uuid_len + perm_hw_addr_fake_len);

    device_state->ifindex                        = ifindex;
    device_state->managed                        = managed_type;
    device_state->connection_uuid                = NULL;
    device_state->perm_hw_addr_fake              = NULL;
    device_state->nm_owned                       = nm_owned;
    device_state->route_metric_default_aspired   = route_metric_default_aspired;
    device_state->route_metric_default_effective = route_metric_default_effective;

    p = (char *) (&device_state[1]);
    if (connection_uuid) {
        memcpy(p, connection_uuid, connection_uuid_len);
        device_state->connection_uuid = p;
        p += connection_uuid_len;
    }
    if (perm_hw_addr_fake) {
        memcpy(p, perm_hw_addr_fake, perm_hw_addr_fake_len);
        device_state->perm_hw_addr_fake = p;
        p += perm_hw_addr_fake_len;
    }

    return device_state;
}

#define DEVICE_STATE_FILENAME_LEN_MAX 60

/**
 * nm_config_device_state_load:
 * @ifindex: the ifindex for which the state is to load
 *
 * Returns: (transfer full): a run state object.
 *   Must be freed with g_free().
 */
NMConfigDeviceStateData *
nm_config_device_state_load(int ifindex)
{
    NMConfigDeviceStateData *device_state;
    char path[NM_STRLEN(NM_CONFIG_DEVICE_STATE_DIR "/") + DEVICE_STATE_FILENAME_LEN_MAX + 1];
    nm_auto_unref_keyfile GKeyFile *kf = NULL;
    const char *                    nm_owned_str;

    g_return_val_if_fail(ifindex > 0, NULL);

    nm_sprintf_buf(path, "%s/%d", NM_CONFIG_DEVICE_STATE_DIR, ifindex);

    kf = nm_config_create_keyfile();
    if (!g_key_file_load_from_file(kf, path, G_KEY_FILE_NONE, NULL))
        return NULL;

    device_state = _config_device_state_data_new(ifindex, kf);
    nm_owned_str = device_state->nm_owned == NM_TERNARY_TRUE
                       ? ", nm-owned=1"
                       : (device_state->nm_owned == NM_TERNARY_FALSE ? ", nm-owned=0" : "");

    _LOGT("device-state: %s #%d (%s); managed=%s%s%s%s%s%s%s%s, "
          "route-metric-default=%" G_GUINT32_FORMAT "-%" G_GUINT32_FORMAT "",
          kf ? "read" : "miss",
          ifindex,
          path,
          _device_state_managed_type_to_str(device_state->managed),
          NM_PRINT_FMT_QUOTED(device_state->connection_uuid,
                              ", connection-uuid=",
                              device_state->connection_uuid,
                              "",
                              ""),
          NM_PRINT_FMT_QUOTED(device_state->perm_hw_addr_fake,
                              ", perm-hw-addr-fake=",
                              device_state->perm_hw_addr_fake,
                              "",
                              ""),
          nm_owned_str,
          device_state->route_metric_default_aspired,
          device_state->route_metric_default_effective);

    return device_state;
}

static int
_device_state_parse_filename(const char *filename)
{
    if (!filename || !filename[0])
        return 0;
    if (!NM_STRCHAR_ALL(filename, ch, g_ascii_isdigit(ch)))
        return 0;
    return _nm_utils_ascii_str_to_int64(filename, 10, 1, G_MAXINT, 0);
}

GHashTable *
nm_config_device_state_load_all(void)
{
    GHashTable *states;
    GDir *      dir;
    const char *fn;
    int         ifindex;

    states = g_hash_table_new_full(nm_direct_hash, NULL, NULL, g_free);

    dir = g_dir_open(NM_CONFIG_DEVICE_STATE_DIR, 0, NULL);
    if (!dir)
        return states;

    while ((fn = g_dir_read_name(dir))) {
        NMConfigDeviceStateData *state;

        ifindex = _device_state_parse_filename(fn);
        if (ifindex <= 0)
            continue;

        state = nm_config_device_state_load(ifindex);
        if (!state)
            continue;

        if (!g_hash_table_insert(states, GINT_TO_POINTER(ifindex), state))
            nm_assert_not_reached();
    }
    g_dir_close(dir);

    return states;
}

gboolean
nm_config_device_state_write(int                            ifindex,
                             NMConfigDeviceStateManagedType managed,
                             const char *                   perm_hw_addr_fake,
                             const char *                   connection_uuid,
                             NMTernary                      nm_owned,
                             guint32                        route_metric_default_aspired,
                             guint32                        route_metric_default_effective,
                             const char *                   next_server,
                             const char *                   root_path,
                             const char *                   dhcp_bootfile)
{
    char    path[NM_STRLEN(NM_CONFIG_DEVICE_STATE_DIR "/") + DEVICE_STATE_FILENAME_LEN_MAX + 1];
    GError *local                      = NULL;
    nm_auto_unref_keyfile GKeyFile *kf = NULL;

    g_return_val_if_fail(ifindex > 0, FALSE);
    g_return_val_if_fail(!connection_uuid || *connection_uuid, FALSE);
    g_return_val_if_fail(managed == NM_CONFIG_DEVICE_STATE_MANAGED_TYPE_MANAGED || !connection_uuid,
                         FALSE);

    nm_assert(!perm_hw_addr_fake || nm_utils_hwaddr_valid(perm_hw_addr_fake, -1));

    nm_sprintf_buf(path, "%s/%d", NM_CONFIG_DEVICE_STATE_DIR, ifindex);

    kf = nm_config_create_keyfile();
    if (NM_IN_SET(managed,
                  NM_CONFIG_DEVICE_STATE_MANAGED_TYPE_MANAGED,
                  NM_CONFIG_DEVICE_STATE_MANAGED_TYPE_UNMANAGED)) {
        g_key_file_set_boolean(kf,
                               DEVICE_RUN_STATE_KEYFILE_GROUP_DEVICE,
                               DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_MANAGED,
                               managed == NM_CONFIG_DEVICE_STATE_MANAGED_TYPE_MANAGED);
    }
    if (perm_hw_addr_fake) {
        g_key_file_set_string(kf,
                              DEVICE_RUN_STATE_KEYFILE_GROUP_DEVICE,
                              DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_PERM_HW_ADDR_FAKE,
                              perm_hw_addr_fake);
    }
    if (connection_uuid) {
        g_key_file_set_string(kf,
                              DEVICE_RUN_STATE_KEYFILE_GROUP_DEVICE,
                              DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_CONNECTION_UUID,
                              connection_uuid);
    }
    if (nm_owned != NM_TERNARY_DEFAULT) {
        g_key_file_set_boolean(kf,
                               DEVICE_RUN_STATE_KEYFILE_GROUP_DEVICE,
                               DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_NM_OWNED,
                               nm_owned);
    }

    if (route_metric_default_effective != 0) {
        g_key_file_set_int64(kf,
                             DEVICE_RUN_STATE_KEYFILE_GROUP_DEVICE,
                             DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_ROUTE_METRIC_DEFAULT_EFFECTIVE,
                             route_metric_default_effective);
        if (route_metric_default_aspired != route_metric_default_effective) {
            g_key_file_set_int64(kf,
                                 DEVICE_RUN_STATE_KEYFILE_GROUP_DEVICE,
                                 DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_ROUTE_METRIC_DEFAULT_ASPIRED,
                                 route_metric_default_aspired);
        }
    }
    if (next_server) {
        g_key_file_set_string(kf,
                              DEVICE_RUN_STATE_KEYFILE_GROUP_DEVICE,
                              DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_NEXT_SERVER,
                              next_server);
    }
    if (root_path) {
        g_key_file_set_string(kf,
                              DEVICE_RUN_STATE_KEYFILE_GROUP_DEVICE,
                              DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_ROOT_PATH,
                              root_path);
    }
    if (dhcp_bootfile) {
        g_key_file_set_string(kf,
                              DEVICE_RUN_STATE_KEYFILE_GROUP_DEVICE,
                              DEVICE_RUN_STATE_KEYFILE_KEY_DEVICE_DHCP_BOOTFILE,
                              dhcp_bootfile);
    }

    if (!g_key_file_save_to_file(kf, path, &local)) {
        _LOGW("device-state: write #%d (%s) failed: %s", ifindex, path, local->message);
        g_error_free(local);
        return FALSE;
    }
    _LOGT("device-state: write #%d (%s); managed=%s%s%s%s%s%s%s, "
          "route-metric-default=%" G_GUINT32_FORMAT "-%" G_GUINT32_FORMAT "%s%s%s"
          "%s%s%s"
          "%s%s%s",
          ifindex,
          path,
          _device_state_managed_type_to_str(managed),
          NM_PRINT_FMT_QUOTED(connection_uuid, ", connection-uuid=", connection_uuid, "", ""),
          NM_PRINT_FMT_QUOTED(perm_hw_addr_fake, ", perm-hw-addr-fake=", perm_hw_addr_fake, "", ""),
          route_metric_default_aspired,
          route_metric_default_effective,
          NM_PRINT_FMT_QUOTED(next_server, ", next-server=", next_server, "", ""),
          NM_PRINT_FMT_QUOTED(root_path, ", root-path=", root_path, "", ""),
          NM_PRINT_FMT_QUOTED(dhcp_bootfile, ", dhcp-bootfile=", dhcp_bootfile, "", ""));
    return TRUE;
}

void
nm_config_device_state_prune_stale(GHashTable *preserve_ifindexes, NMPlatform *preserve_in_platform)
{
    GDir *      dir;
    const char *fn;
    char        buf[NM_STRLEN(NM_CONFIG_DEVICE_STATE_DIR "/") + DEVICE_STATE_FILENAME_LEN_MAX + 1] =
        NM_CONFIG_DEVICE_STATE_DIR "/";
    char *buf_p = &buf[NM_STRLEN(NM_CONFIG_DEVICE_STATE_DIR "/")];

    dir = g_dir_open(NM_CONFIG_DEVICE_STATE_DIR, 0, NULL);
    if (!dir)
        return;

    while ((fn = g_dir_read_name(dir))) {
        int   ifindex;
        gsize fn_len;

        ifindex = _device_state_parse_filename(fn);
        if (ifindex <= 0)
            continue;

        if (preserve_ifindexes
            && g_hash_table_contains(preserve_ifindexes, GINT_TO_POINTER(ifindex)))
            continue;

        if (preserve_in_platform && nm_platform_link_get(preserve_in_platform, ifindex))
            continue;

        fn_len = strlen(fn);
        nm_assert(fn_len > 0);
        nm_assert(&buf_p[fn_len] < &buf[G_N_ELEMENTS(buf)]);
        memcpy(buf_p, fn, fn_len + 1u);
        nm_assert(({
            char bb[30];

            nm_streq0(nm_sprintf_buf(bb, "%d", ifindex), buf_p);
        }));
        _LOGT("device-state: prune #%d (%s)", ifindex, buf);
        (void) unlink(buf);
    }

    g_dir_close(dir);
}

/*****************************************************************************/

static GHashTable *
_device_state_get_all(NMConfig *self)
{
    NMConfigPrivate *priv = NM_CONFIG_GET_PRIVATE(self);

    if (G_UNLIKELY(!priv->device_states))
        priv->device_states = nm_config_device_state_load_all();
    return priv->device_states;
}

/**
 * nm_config_device_state_get_all:
 * @self: the #NMConfig
 *
 * This function exists to give convenient access to all
 * device states. Do not ever try to modify the returned
 * hash, it's supposed to be immutable.
 *
 * Returns: the internal #GHashTable object with all device states.
 */
const GHashTable *
nm_config_device_state_get_all(NMConfig *self)
{
    g_return_val_if_fail(NM_IS_CONFIG(self), NULL);

    return _device_state_get_all(self);
}

const NMConfigDeviceStateData *
nm_config_device_state_get(NMConfig *self, int ifindex)
{
    g_return_val_if_fail(NM_IS_CONFIG(self), NULL);
    g_return_val_if_fail(ifindex > 0, NULL);

    return g_hash_table_lookup(_device_state_get_all(self), GINT_TO_POINTER(ifindex));
}

/*****************************************************************************/

void
nm_config_reload(NMConfig *self, NMConfigChangeFlags reload_flags, gboolean emit_warnings)
{
    NMConfigPrivate *  priv;
    GError *           error = NULL;
    GKeyFile *         keyfile, *keyfile_intern;
    NMConfigData *     new_data           = NULL;
    char *             config_main_file   = NULL;
    char *             config_description = NULL;
    gs_strfreev char **no_auto_default    = NULL;
    gboolean           intern_config_needs_rewrite;
    gs_unref_ptrarray GPtrArray *warnings = NULL;
    guint                        i;

    g_return_if_fail(NM_IS_CONFIG(self));
    g_return_if_fail(reload_flags && !NM_FLAGS_ANY(reload_flags, ~NM_CONFIG_CHANGE_CAUSES)
                     && !NM_FLAGS_ANY(reload_flags,
                                      NM_CONFIG_CHANGE_CAUSE_NO_AUTO_DEFAULT
                                          | NM_CONFIG_CHANGE_CAUSE_SET_VALUES));

    priv = NM_CONFIG_GET_PRIVATE(self);

    if (!NM_FLAGS_ANY(reload_flags, NM_CONFIG_CHANGE_CAUSE_SIGHUP | NM_CONFIG_CHANGE_CAUSE_CONF)) {
        /* unless SIGHUP is specified, we don't reload the configuration from disc. */
        _set_config_data(self, NULL, reload_flags);
        return;
    }

    warnings = g_ptr_array_new_with_free_func(g_free);

    /* pass on the original command line options. This means, that
     * options specified at command line cannot ever be reloaded from
     * file. That seems desirable.
     */
    keyfile = read_entire_config(&priv->cli,
                                 priv->config_dir,
                                 priv->system_config_dir,
                                 &config_main_file,
                                 &config_description,
                                 warnings,
                                 &error);
    if (!keyfile) {
        _LOGE("Failed to reload the configuration: %s", error->message);
        g_clear_error(&error);
        _set_config_data(self, NULL, reload_flags);
        return;
    }

    no_auto_default = no_auto_default_from_file(priv->no_auto_default_file);

    keyfile_intern = intern_config_read(priv->intern_config_file,
                                        keyfile,
                                        (const char *const *) priv->atomic_section_prefixes,
                                        &intern_config_needs_rewrite);
    if (intern_config_needs_rewrite) {
        intern_config_write(priv->intern_config_file,
                            keyfile_intern,
                            keyfile,
                            (const char *const *) priv->atomic_section_prefixes,
                            NULL);
    }

    new_data = nm_config_data_new(config_main_file,
                                  config_description,
                                  (const char *const *) no_auto_default,
                                  keyfile,
                                  keyfile_intern);

    if (emit_warnings) {
        nm_config_data_get_warnings(priv->config_data_orig, warnings);
        for (i = 0; i < warnings->len; i++)
            _LOGW("%s", (const char *) warnings->pdata[i]);
    }

    g_free(config_main_file);
    g_free(config_description);
    g_key_file_unref(keyfile);
    if (keyfile_intern)
        g_key_file_unref(keyfile_intern);

    _set_config_data(self, new_data, reload_flags);
}

NM_UTILS_FLAGS2STR_DEFINE(nm_config_change_flags_to_string,
                          NMConfigChangeFlags,

                          NM_UTILS_FLAGS2STR(NM_CONFIG_CHANGE_CAUSE_CONF, "CONF"),
                          NM_UTILS_FLAGS2STR(NM_CONFIG_CHANGE_CAUSE_DNS_RC, "DNS_RC"),
                          NM_UTILS_FLAGS2STR(NM_CONFIG_CHANGE_CAUSE_DNS_FULL, "DNS_FULL"),
                          NM_UTILS_FLAGS2STR(NM_CONFIG_CHANGE_CAUSE_SIGHUP, "SIGHUP"),
                          NM_UTILS_FLAGS2STR(NM_CONFIG_CHANGE_CAUSE_SIGUSR1, "SIGUSR1"),
                          NM_UTILS_FLAGS2STR(NM_CONFIG_CHANGE_CAUSE_SIGUSR2, "SIGUSR2"),
                          NM_UTILS_FLAGS2STR(NM_CONFIG_CHANGE_CAUSE_NO_AUTO_DEFAULT,
                                             "NO_AUTO_DEFAULT"),
                          NM_UTILS_FLAGS2STR(NM_CONFIG_CHANGE_CAUSE_SET_VALUES, "SET_VALUES"),

                          NM_UTILS_FLAGS2STR(NM_CONFIG_CHANGE_CONFIG_FILES, "config-files"),
                          NM_UTILS_FLAGS2STR(NM_CONFIG_CHANGE_VALUES, "values"),
                          NM_UTILS_FLAGS2STR(NM_CONFIG_CHANGE_VALUES_USER, "values-user"),
                          NM_UTILS_FLAGS2STR(NM_CONFIG_CHANGE_VALUES_INTERN, "values-intern"),
                          NM_UTILS_FLAGS2STR(NM_CONFIG_CHANGE_CONNECTIVITY, "connectivity"),
                          NM_UTILS_FLAGS2STR(NM_CONFIG_CHANGE_NO_AUTO_DEFAULT, "no-auto-default"),
                          NM_UTILS_FLAGS2STR(NM_CONFIG_CHANGE_DNS_MODE, "dns-mode"),
                          NM_UTILS_FLAGS2STR(NM_CONFIG_CHANGE_RC_MANAGER, "rc-manager"),
                          NM_UTILS_FLAGS2STR(NM_CONFIG_CHANGE_GLOBAL_DNS_CONFIG,
                                             "global-dns-config"), );

static void
_set_config_data(NMConfig *self, NMConfigData *new_data, NMConfigChangeFlags reload_flags)
{
    NMConfigPrivate *   priv     = NM_CONFIG_GET_PRIVATE(self);
    NMConfigData *      old_data = priv->config_data;
    NMConfigChangeFlags changes, changes_diff;
    gboolean            had_new_data = !!new_data;

    nm_assert(reload_flags);
    nm_assert(!NM_FLAGS_ANY(reload_flags, ~NM_CONFIG_CHANGE_CAUSES));
    nm_assert(NM_IN_SET(reload_flags,
                        NM_CONFIG_CHANGE_CAUSE_NO_AUTO_DEFAULT,
                        NM_CONFIG_CHANGE_CAUSE_SET_VALUES)
              || !NM_FLAGS_ANY(reload_flags,
                               NM_CONFIG_CHANGE_CAUSE_NO_AUTO_DEFAULT
                                   | NM_CONFIG_CHANGE_CAUSE_SET_VALUES));

    changes = reload_flags;

    if (new_data) {
        changes_diff = nm_config_data_diff(old_data, new_data);
        if (changes_diff == NM_CONFIG_CHANGE_NONE)
            g_clear_object(&new_data);
        else
            changes |= changes_diff;
    }

    if (NM_IN_SET(reload_flags,
                  NM_CONFIG_CHANGE_CAUSE_NO_AUTO_DEFAULT,
                  NM_CONFIG_CHANGE_CAUSE_SET_VALUES,
                  NM_CONFIG_CHANGE_CAUSE_CONF)
        && !new_data) {
        /* no relevant changes that should be propagated. Return silently. */
        return;
    }

    if (new_data) {
        _LOGI("signal: %s (%s)",
              nm_config_change_flags_to_string(changes, NULL, 0),
              nm_config_data_get_config_description(new_data));
        nm_config_data_log(new_data, "CONFIG: ", "  ", priv->no_auto_default_file, NULL);
        priv->config_data = new_data;
    } else if (had_new_data)
        _LOGI("signal: %s (no changes from disk)",
              nm_config_change_flags_to_string(changes, NULL, 0));
    else
        _LOGI("signal: %s", nm_config_change_flags_to_string(changes, NULL, 0));
    g_signal_emit(self, signals[SIGNAL_CONFIG_CHANGED], 0, new_data ?: old_data, changes, old_data);
    if (new_data)
        g_object_unref(old_data);
}

NM_DEFINE_SINGLETON_REGISTER(NMConfig);

NMConfig *
nm_config_get(void)
{
    g_assert(singleton_instance);
    return singleton_instance;
}

NMConfig *
nm_config_setup(const NMConfigCmdLineOptions *cli, char **atomic_section_prefixes, GError **error)
{
    g_assert(!singleton_instance);

    singleton_instance = nm_config_new(cli, atomic_section_prefixes, error);
    if (singleton_instance) {
        nm_singleton_instance_register();

        /* usually, you would not see this logging line because when creating the
         * NMConfig instance, the logging is not yet set up to print debug message. */
        nm_log_dbg(LOGD_CORE,
                   "setup %s singleton (" NM_HASH_OBFUSCATE_PTR_FMT ")",
                   "NMConfig",
                   NM_HASH_OBFUSCATE_PTR(singleton_instance));
    }
    return singleton_instance;
}

/*****************************************************************************/

static void
set_property(GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
{
    NMConfig *              self = NM_CONFIG(object);
    NMConfigPrivate *       priv = NM_CONFIG_GET_PRIVATE(self);
    NMConfigCmdLineOptions *cli;
    char **                 strv;

    switch (prop_id) {
    case PROP_CMD_LINE_OPTIONS:
        /* construct-only */
        cli = g_value_get_pointer(value);
        if (!cli)
            _nm_config_cmd_line_options_clear(&priv->cli);
        else
            _nm_config_cmd_line_options_copy(cli, &priv->cli);
        break;
    case PROP_ATOMIC_SECTION_PREFIXES:
        /* construct-only */
        strv = g_value_get_boxed(value);
        if (strv && !strv[0])
            strv = NULL;
        priv->atomic_section_prefixes = g_strdupv(strv);
        break;
    default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
        break;
    }
}

/*****************************************************************************/

static gboolean
init_sync(GInitable *initable, GCancellable *cancellable, GError **error)
{
    NMConfig *            self                         = NM_CONFIG(initable);
    NMConfigPrivate *     priv                         = NM_CONFIG_GET_PRIVATE(self);
    nm_auto_unref_keyfile GKeyFile *keyfile            = NULL;
    nm_auto_unref_keyfile GKeyFile *keyfile_intern     = NULL;
    gs_free char *                  config_main_file   = NULL;
    gs_free char *                  config_description = NULL;
    gs_strfreev char **             no_auto_default    = NULL;
    gs_unref_ptrarray GPtrArray *warnings              = NULL;
    gs_free char *               configure_and_quit    = NULL;
    gboolean                     intern_config_needs_rewrite;
    const char *                 s;

    if (priv->config_dir) {
        /* Object is already initialized. */
        if (priv->config_data)
            return TRUE;
        g_set_error(error, G_KEY_FILE_ERROR, G_KEY_FILE_ERROR_NOT_FOUND, "unspecified error");
        g_return_val_if_reached(FALSE);
    }

    s                = priv->cli.config_dir ?: "" DEFAULT_CONFIG_DIR;
    priv->config_dir = g_strdup(s[0] == '/' ? s : "");

    s = priv->cli.system_config_dir ?: "" DEFAULT_SYSTEM_CONFIG_DIR;
    if (s[0] != '/' || nm_streq(s, priv->config_dir))
        s = "";
    priv->system_config_dir = g_strdup(s);

    if (priv->cli.intern_config_file)
        priv->intern_config_file = g_strdup(priv->cli.intern_config_file);
    else
        priv->intern_config_file = g_strdup(DEFAULT_INTERN_CONFIG_FILE);

    warnings = g_ptr_array_new_with_free_func(g_free);

    keyfile = read_entire_config(&priv->cli,
                                 priv->config_dir,
                                 priv->system_config_dir,
                                 &config_main_file,
                                 &config_description,
                                 warnings,
                                 error);
    if (!keyfile)
        return FALSE;

    /* Initialize read-only private members */

    if (priv->cli.no_auto_default_file)
        priv->no_auto_default_file = g_strdup(priv->cli.no_auto_default_file);
    else
        priv->no_auto_default_file = g_strdup(DEFAULT_NO_AUTO_DEFAULT_FILE);

    priv->log_level   = nm_strstrip(g_key_file_get_string(keyfile,
                                                        NM_CONFIG_KEYFILE_GROUP_LOGGING,
                                                        NM_CONFIG_KEYFILE_KEY_LOGGING_LEVEL,
                                                        NULL));
    priv->log_domains = nm_strstrip(g_key_file_get_string(keyfile,
                                                          NM_CONFIG_KEYFILE_GROUP_LOGGING,
                                                          NM_CONFIG_KEYFILE_KEY_LOGGING_DOMAINS,
                                                          NULL));
    configure_and_quit =
        nm_strstrip(g_key_file_get_string(keyfile,
                                          NM_CONFIG_KEYFILE_GROUP_MAIN,
                                          NM_CONFIG_KEYFILE_KEY_MAIN_CONFIGURE_AND_QUIT,
                                          NULL));
    priv->configure_and_quit = string_to_configure_and_quit(configure_and_quit, error);
    if (priv->configure_and_quit == NM_CONFIG_CONFIGURE_AND_QUIT_INVALID)
        return FALSE;

    no_auto_default = no_auto_default_from_file(priv->no_auto_default_file);

    keyfile_intern = intern_config_read(priv->intern_config_file,
                                        keyfile,
                                        (const char *const *) priv->atomic_section_prefixes,
                                        &intern_config_needs_rewrite);
    if (intern_config_needs_rewrite
        && priv->configure_and_quit == NM_CONFIG_CONFIGURE_AND_QUIT_DISABLED) {
        intern_config_write(priv->intern_config_file,
                            keyfile_intern,
                            keyfile,
                            (const char *const *) priv->atomic_section_prefixes,
                            NULL);
    }

    priv->config_data_orig = nm_config_data_new(config_main_file,
                                                config_description,
                                                (const char *const *) no_auto_default,
                                                keyfile,
                                                keyfile_intern);

    nm_config_data_get_warnings(priv->config_data_orig, warnings);

    priv->config_data = g_object_ref(priv->config_data_orig);
    if (warnings->len > 0) {
        g_ptr_array_add(warnings, NULL);
        priv->warnings = (char **) g_ptr_array_free(g_steal_pointer(&warnings), FALSE);
    }
    return TRUE;
}

/*****************************************************************************/

static void
nm_config_init(NMConfig *config)
{}

NMConfig *
nm_config_new(const NMConfigCmdLineOptions *cli, char **atomic_section_prefixes, GError **error)
{
    return NM_CONFIG(g_initable_new(NM_TYPE_CONFIG,
                                    NULL,
                                    error,
                                    NM_CONFIG_CMD_LINE_OPTIONS,
                                    cli,
                                    NM_CONFIG_ATOMIC_SECTION_PREFIXES,
                                    atomic_section_prefixes,
                                    NULL));
}

static void
finalize(GObject *gobject)
{
    NMConfigPrivate *priv = NM_CONFIG_GET_PRIVATE(gobject);

    state_free(priv->state);

    g_free(priv->config_dir);
    g_free(priv->system_config_dir);
    g_free(priv->no_auto_default_file);
    g_free(priv->intern_config_file);
    g_free(priv->log_level);
    g_free(priv->log_domains);
    g_strfreev(priv->atomic_section_prefixes);
    g_strfreev(priv->warnings);

    _nm_config_cmd_line_options_clear(&priv->cli);

    g_clear_object(&priv->config_data);
    g_clear_object(&priv->config_data_orig);

    G_OBJECT_CLASS(nm_config_parent_class)->finalize(gobject);
}

static void
nm_config_class_init(NMConfigClass *config_class)
{
    GObjectClass *object_class = G_OBJECT_CLASS(config_class);

    object_class->finalize     = finalize;
    object_class->set_property = set_property;

    obj_properties[PROP_CMD_LINE_OPTIONS] =
        g_param_spec_pointer(NM_CONFIG_CMD_LINE_OPTIONS,
                             "",
                             "",
                             G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS);

    obj_properties[PROP_ATOMIC_SECTION_PREFIXES] =
        g_param_spec_boxed(NM_CONFIG_ATOMIC_SECTION_PREFIXES,
                           "",
                           "",
                           G_TYPE_STRV,
                           G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS);

    g_object_class_install_properties(object_class, _PROPERTY_ENUMS_LAST, obj_properties);

    signals[SIGNAL_CONFIG_CHANGED] =
        g_signal_new(NM_CONFIG_SIGNAL_CONFIG_CHANGED,
                     G_OBJECT_CLASS_TYPE(object_class),
                     G_SIGNAL_RUN_FIRST,
                     0,
                     NULL,
                     NULL,
                     NULL,
                     G_TYPE_NONE,
                     3,
                     NM_TYPE_CONFIG_DATA,
                     /* Use plain guint type for changes argument. This avoids
                      * glib/ffi bug https://bugzilla.redhat.com/show_bug.cgi?id=1260577 */
                     /* NM_TYPE_CONFIG_CHANGE_FLAGS, */
                     G_TYPE_UINT,
                     NM_TYPE_CONFIG_DATA);

    G_STATIC_ASSERT_EXPR(sizeof(guint) == sizeof(NMConfigChangeFlags));
    G_STATIC_ASSERT_EXPR(((gint64) ((NMConfigChangeFlags) -1)) > ((gint64) 0));
}

static void
nm_config_initable_iface_init(GInitableIface *iface)
{
    iface->init = init_sync;
}
