NetworkManager/src/libnm-core-impl/nm-setting-user.c

/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2017 Red Hat, Inc.
 */

#include "libnm-core-impl/nm-default-libnm-core.h"

#include "nm-setting-user.h"

#include "nm-setting.h"
#include "nm-setting-private.h"
#include "nm-utils-private.h"

/**
 * SECTION:nm-setting-user
 * @short_description: Describes user properties
 *
 * The #NMSettingUser object is a #NMSetting subclass that allow to attach
 * arbitrary user data to #NMConnection objects.
 **/

#define MAX_NUM_KEYS 256

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

NM_GOBJECT_PROPERTIES_DEFINE(NMSettingUser, PROP_DATA, );

typedef struct {
    GHashTable  *data;
    GHashTable  *data_invalid;
    const char **keys;
} NMSettingUserPrivate;

/**
 * NMSettingUser:
 *
 * General User Profile Settings
 *
 * Since: 1.8
 */
struct _NMSettingUser {
    NMSetting            parent;
    NMSettingUserPrivate _priv;
};

struct _NMSettingUserClass {
    NMSettingClass parent;
};

G_DEFINE_TYPE(NMSettingUser, nm_setting_user, NM_TYPE_SETTING)

#define NM_SETTING_USER_GET_PRIVATE(self) _NM_GET_PRIVATE(self, NMSettingUser, NM_IS_SETTING_USER)

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

static gboolean
_key_char_is_regular(char ch)
{
    /* allow words of printable characters, plus some
     * special characters, for example to support base64 encoding. */
    return (ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z') || (ch >= '0' && ch <= '9')
           || NM_IN_SET(ch, '-', '_', '+', '/', '=');
}

/**
 * nm_setting_user_check_key:
 * @key: the key to check
 * @error: a #GError, %NULL to ignore.
 *
 * Checks whether @key is a valid user data key. This means,
 * key is not %NULL, not too large and valid ASCII. Also,
 * only digits and numbers are allowed with a few special
 * characters. The key must contain at least one '.' and
 * look like a fully qualified DNS name.
 *
 * Since: 1.8
 *
 * Returns: %TRUE if @key is a valid user data key.
 */
gboolean
nm_setting_user_check_key(const char *key, GError **error)
{
    gsize    len;
    gboolean has_dot;
    char     ch;

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

    if (!key || !key[0]) {
        g_set_error_literal(error,
                            NM_CONNECTION_ERROR,
                            NM_CONNECTION_ERROR_INVALID_PROPERTY,
                            _("missing key"));
        return FALSE;
    }
    len = strlen(key);
    if (len > 255) {
        g_set_error_literal(error,
                            NM_CONNECTION_ERROR,
                            NM_CONNECTION_ERROR_INVALID_PROPERTY,
                            _("key is too long"));
        return FALSE;
    }
    if (!g_utf8_validate(key, len, NULL)) {
        g_set_error_literal(error,
                            NM_CONNECTION_ERROR,
                            NM_CONNECTION_ERROR_INVALID_PROPERTY,
                            _("key must be UTF8"));
        return FALSE;
    }

    has_dot = FALSE;
    while (TRUE) {
        ch = (key++)[0];

        /* Allow something that looks like a FQN, separating namespaces by a single '.'
         * We want to print the keys nicely in nmcli requiring escaping.
         *
         * If a user really has to encode special values in the name, he may base64 encode it. */

        if (!_key_char_is_regular(ch))
            break;

        while (_key_char_is_regular(key[0]))
            key++;

        ch = key[0];
        if (ch == '\0') {
            if (!has_dot) {
                g_set_error_literal(error,
                                    NM_CONNECTION_ERROR,
                                    NM_CONNECTION_ERROR_INVALID_PROPERTY,
                                    _("key requires a '.' for a namespace"));
                return FALSE;
            }
            return TRUE;
        }

        if (ch != '.')
            break;

        has_dot = TRUE;
        ch      = (++key)[0];
        if (ch == '.') {
            g_set_error_literal(error,
                                NM_CONNECTION_ERROR,
                                NM_CONNECTION_ERROR_INVALID_PROPERTY,
                                _("key cannot contain \"..\""));
            return FALSE;
        }
    }
    g_set_error_literal(error,
                        NM_CONNECTION_ERROR,
                        NM_CONNECTION_ERROR_INVALID_PROPERTY,
                        _("key contains invalid characters"));
    return FALSE;
}

/**
 * nm_setting_user_check_val:
 * @val: the value to check
 * @error: a #GError, %NULL to ignore.
 *
 * Checks whether @val is a valid user data value. This means,
 * value is not %NULL, not too large and valid UTF-8.
 *
 * Since: 1.8
 *
 * Returns: %TRUE if @val is a valid user data value.
 */
gboolean
nm_setting_user_check_val(const char *val, GError **error)
{
    gsize len;

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

    if (!val) {
        g_set_error_literal(error,
                            NM_CONNECTION_ERROR,
                            NM_CONNECTION_ERROR_INVALID_PROPERTY,
                            _("value is missing"));
        return FALSE;
    }

    len = strlen(val);
    if (len > 8 * 1024) {
        g_set_error_literal(error,
                            NM_CONNECTION_ERROR,
                            NM_CONNECTION_ERROR_INVALID_PROPERTY,
                            _("value is too large"));
        return FALSE;
    }

    if (!g_utf8_validate(val, len, NULL)) {
        g_set_error_literal(error,
                            NM_CONNECTION_ERROR,
                            NM_CONNECTION_ERROR_INVALID_PROPERTY,
                            _("value is not valid UTF8"));
        return FALSE;
    }

    return TRUE;
}

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

static GHashTable *
_create_data_hash(void)
{
    return g_hash_table_new_full(nm_str_hash, g_str_equal, g_free, g_free);
}

/**
 * nm_setting_user_get_keys:
 * @setting: the #NMSettingUser
 * @out_len: (out): the length of the returned array
 *
 * Returns: (array length=out_len) (transfer none): a
 *   %NULL-terminated array containing each key from the table.
 *
 * Since: 1.8
  **/
const char *const *
nm_setting_user_get_keys(NMSettingUser *setting, guint *out_len)
{
    NMSettingUser        *self = setting;
    NMSettingUserPrivate *priv;

    g_return_val_if_fail(NM_IS_SETTING_USER(self), NULL);

    priv = NM_SETTING_USER_GET_PRIVATE(self);

    if (priv->keys) {
        NM_SET_OUT(out_len, g_hash_table_size(priv->data));
        return priv->keys;
    }

    priv->keys = nm_strdict_get_keys(priv->data, TRUE, out_len);

    /* don't return %NULL, but hijack the @keys fields as a pseudo
     * empty strv array. */
    return priv->keys ?: ((const char **) &priv->keys);
}

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

/**
 * nm_setting_user_get_data:
 * @setting: the #NMSettingUser instance
 * @key: the key to lookup
 *
 * Since: 1.8
 *
 * Returns: (transfer none): the value associated with @key or %NULL if no such
 *   value exists.
 */
const char *
nm_setting_user_get_data(NMSettingUser *setting, const char *key)
{
    g_return_val_if_fail(NM_IS_SETTING_USER(setting), NULL);
    g_return_val_if_fail(key, NULL);

    return nm_g_hash_table_lookup(NM_SETTING_USER_GET_PRIVATE(setting)->data, key);
}

/**
 * nm_setting_user_set_data:
 * @setting: the #NMSettingUser instance
 * @key: the key to set
 * @val: (nullable): the value to set or %NULL to clear a key.
 * @error: optional error argument
 *
 * Since: 1.8
 *
 * Returns: %TRUE if the operation was successful. The operation
 *   can fail if @key or @val are not valid strings according
 *   to nm_setting_user_check_key() and nm_setting_user_check_val().
 */
gboolean
nm_setting_user_set_data(NMSettingUser *setting, const char *key, const char *val, GError **error)
{
    NMSettingUser        *self = setting;
    NMSettingUserPrivate *priv;
    gboolean              changed = FALSE;

    g_return_val_if_fail(NM_IS_SETTING_USER(self), FALSE);
    g_return_val_if_fail(!error || !*error, FALSE);

    if (!nm_setting_user_check_key(key, error))
        return FALSE;

    if (val && !nm_setting_user_check_val(val, error))
        return FALSE;

    priv = NM_SETTING_USER_GET_PRIVATE(self);

    if (!val) {
        if (priv->data && g_hash_table_remove(priv->data, key)) {
            nm_clear_g_free(&priv->keys);
            changed = TRUE;
        }
        goto out;
    }

    if (priv->data) {
        const char *key2, *val2;

        if (g_hash_table_lookup_extended(priv->data, key, (gpointer *) &key2, (gpointer *) &val2)) {
            if (nm_streq(val, val2))
                goto out;
        } else {
            if (g_hash_table_size(priv->data) >= MAX_NUM_KEYS) {
                /* limit the number of valid keys */
                g_set_error_literal(error,
                                    NM_CONNECTION_ERROR,
                                    NM_CONNECTION_ERROR_INVALID_PROPERTY,
                                    _("maximum number of user data entries reached"));
                return FALSE;
            }

            nm_clear_g_free(&priv->keys);
        }
    } else
        priv->data = _create_data_hash();

    g_hash_table_insert(priv->data, g_strdup(key), g_strdup(val));
    changed = TRUE;

out:
    if (priv->data_invalid) {
        /* setting a value purges all invalid values that were set
         * via GObject property. */
        changed = TRUE;
        nm_clear_pointer(&priv->data_invalid, g_hash_table_unref);
    }
    if (changed)
        _notify(self, PROP_DATA);
    return TRUE;
}

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

static gboolean
verify(NMSetting *setting, NMConnection *connection, GError **error)
{
    NMSettingUser        *self = NM_SETTING_USER(setting);
    NMSettingUserPrivate *priv = NM_SETTING_USER_GET_PRIVATE(self);

    if (priv->data_invalid) {
        const char           *key, *val;
        GHashTableIter        iter;
        gs_free_error GError *local = NULL;

        g_hash_table_iter_init(&iter, priv->data_invalid);
        while (g_hash_table_iter_next(&iter, (gpointer *) &key, (gpointer *) &val)) {
            if (!nm_setting_user_check_key(key, &local)) {
                g_set_error(error,
                            NM_CONNECTION_ERROR,
                            NM_CONNECTION_ERROR_FAILED,
                            _("invalid key \"%s\": %s"),
                            key,
                            local->message);
            } else if (!nm_setting_user_check_val(val, &local)) {
                g_set_error(error,
                            NM_CONNECTION_ERROR,
                            NM_CONNECTION_ERROR_FAILED,
                            _("invalid value for \"%s\": %s"),
                            key,
                            local->message);
            } else {
                nm_assert_not_reached();
                continue;
            }
            g_prefix_error(error, "%s.%s: ", NM_SETTING_USER_SETTING_NAME, NM_SETTING_USER_DATA);
            return FALSE;
        }
        nm_assert_not_reached();
    }

    if (priv->data && g_hash_table_size(priv->data) > MAX_NUM_KEYS) {
        g_set_error(error,
                    NM_CONNECTION_ERROR,
                    NM_CONNECTION_ERROR_INVALID_PROPERTY,
                    _("maximum number of user data entries reached (%u instead of %u)"),
                    g_hash_table_size(priv->data),
                    (unsigned) MAX_NUM_KEYS);
        g_prefix_error(error, "%s.%s: ", NM_SETTING_USER_SETTING_NAME, NM_SETTING_USER_DATA);
        return FALSE;
    }

    return TRUE;
}

static NMTernary
compare_fcn_data(_NM_SETT_INFO_PROP_COMPARE_FCN_ARGS _nm_nil)
{
    NMSettingUserPrivate *priv;
    NMSettingUserPrivate *pri2;

    if (NM_FLAGS_HAS(flags, NM_SETTING_COMPARE_FLAG_INFERRABLE))
        return NM_TERNARY_DEFAULT;

    if (!set_b)
        return TRUE;

    priv = NM_SETTING_USER_GET_PRIVATE(NM_SETTING_USER(set_a));
    pri2 = NM_SETTING_USER_GET_PRIVATE(NM_SETTING_USER(set_b));
    return nm_utils_hashtable_equal(priv->data, pri2->data, TRUE, g_str_equal)
           && nm_utils_hashtable_equal(priv->data_invalid, pri2->data_invalid, TRUE, g_str_equal);
}

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

static void
get_property(GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
{
    NMSettingUser        *self = NM_SETTING_USER(object);
    NMSettingUserPrivate *priv = NM_SETTING_USER_GET_PRIVATE(self);
    GHashTableIter        iter;
    GHashTable           *data;
    const char           *key, *val;

    switch (prop_id) {
    case PROP_DATA:
        data = _create_data_hash();
        if (priv->data) {
            g_hash_table_iter_init(&iter, priv->data);
            while (g_hash_table_iter_next(&iter, (gpointer *) &key, (gpointer *) &val))
                g_hash_table_insert(data, g_strdup(key), g_strdup(val));
        }
        if (priv->data_invalid) {
            g_hash_table_iter_init(&iter, priv->data_invalid);
            while (g_hash_table_iter_next(&iter, (gpointer *) &key, (gpointer *) &val))
                g_hash_table_insert(data, g_strdup(key), g_strdup(val));
        }
        g_value_take_boxed(value, data);
        break;
    default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
        break;
    }
}

static void
set_property(GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
{
    NMSettingUser        *self = NM_SETTING_USER(object);
    NMSettingUserPrivate *priv = NM_SETTING_USER_GET_PRIVATE(self);
    GHashTableIter        iter;
    GHashTable           *data;
    const char           *key, *val;

    switch (prop_id) {
    case PROP_DATA:
        nm_clear_g_free(&priv->keys);

        data = g_value_get_boxed(value);
        if (!data || !g_hash_table_size(data)) {
            nm_clear_pointer(&priv->data, g_hash_table_unref);
            nm_clear_pointer(&priv->data_invalid, g_hash_table_unref);
            return;
        }

        if (priv->data)
            g_hash_table_remove_all(priv->data);
        else
            priv->data = _create_data_hash();

        if (priv->data_invalid)
            g_hash_table_remove_all(priv->data_invalid);

        g_hash_table_iter_init(&iter, data);
        while (g_hash_table_iter_next(&iter, (gpointer *) &key, (gpointer *) &val)) {
            if (nm_setting_user_check_key(key, NULL) && nm_setting_user_check_val(val, NULL))
                g_hash_table_insert(priv->data, g_strdup(key), g_strdup(val));
            else {
                if (!priv->data_invalid)
                    priv->data_invalid = _create_data_hash();
                g_hash_table_insert(priv->data_invalid, g_strdup(key), g_strdup(val));
            }
        }
        if (priv->data_invalid && !g_hash_table_size(priv->data_invalid))
            nm_clear_pointer(&priv->data_invalid, g_hash_table_unref);

        break;
    default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
        break;
    }
}

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

static void
nm_setting_user_init(NMSettingUser *self)
{}

/**
 * nm_setting_user_new:
 *
 * Creates a new #NMSettingUser object with default values.
 *
 * Returns: the new empty #NMSettingUser object
 *
 * Since: 1.8
 **/
NMSetting *
nm_setting_user_new(void)
{
    return g_object_new(NM_TYPE_SETTING_USER, NULL);
}

static void
finalize(GObject *object)
{
    NMSettingUser        *self = NM_SETTING_USER(object);
    NMSettingUserPrivate *priv = NM_SETTING_USER_GET_PRIVATE(self);

    g_free(priv->keys);
    if (priv->data)
        g_hash_table_unref(priv->data);
    if (priv->data_invalid)
        g_hash_table_unref(priv->data_invalid);

    G_OBJECT_CLASS(nm_setting_user_parent_class)->finalize(object);
}

static void
nm_setting_user_class_init(NMSettingUserClass *klass)
{
    GObjectClass   *object_class        = G_OBJECT_CLASS(klass);
    NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
    GArray         *properties_override = _nm_sett_info_property_override_create_array();

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

    setting_class->verify = verify;

    /**
     * NMSettingUser:data: (type GHashTable(utf8,utf8))
     *
     * A dictionary of key/value pairs with user data. This data is ignored by NetworkManager
     * and can be used at the users discretion. The keys only support a strict ascii format,
     * but the values can be arbitrary UTF8 strings up to a certain length.
     *
     * Since: 1.8
     **/
    /* ---ifcfg-rh---
     * property: data
     * variable: NM_USER_*
     * description: each key/value pair is stored as a separate variable with
     *   name composed by concatenating NM_USER_ with the encoded key. The key is
     *   encoded by substituting lowercase letters with uppercase and prepending
     *   uppercase letters with an underscore. A dot is encoded as a double
     *   underscore. Remaining characters are encoded as underscore followed by a
     *   3 digit octal representation of the character.
     * example: NM_USER_FOO__BAR=something
     * ---end---
     */
    obj_properties[PROP_DATA] = g_param_spec_boxed(NM_SETTING_USER_DATA,
                                                   "",
                                                   "",
                                                   G_TYPE_HASH_TABLE,
                                                   G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
    _nm_properties_override_gobj(
        properties_override,
        obj_properties[PROP_DATA],
        NM_SETT_INFO_PROPERT_TYPE_GPROP(NM_G_VARIANT_TYPE("a{ss}"),
                                        .typdata_from_dbus.gprop_fcn = _nm_utils_strdict_from_dbus,
                                        .typdata_to_dbus.gprop_type =
                                            NM_SETTING_PROPERTY_TO_DBUS_FCN_GPROP_TYPE_STRDICT,
                                        .compare_fcn   = compare_fcn_data,
                                        .from_dbus_fcn = _nm_setting_property_from_dbus_fcn_gprop,
                                        .from_dbus_is_full = TRUE));

    g_object_class_install_properties(object_class, _PROPERTY_ENUMS_LAST, obj_properties);

    _nm_setting_class_commit(setting_class,
                             NM_META_SETTING_TYPE_USER,
                             NULL,
                             properties_override,
                             0);
}