/* GIO - GLib Input, Output and Streaming Library

 *

 * Copyright (C) 2010 Collabora, Ltd.

 *

 * SPDX-License-Identifier: LGPL-2.1-or-later

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General

 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.

 *

 * Author: Nicolas Dufresne <nicolas.dufresne@collabora.co.uk>

 */

#include "config.h"

#include "gproxyresolver.h"

#include <glib.h>

#include "glibintl.h"

#include "gasyncresult.h"

#include "gcancellable.h"

#include "gtask.h"

#include "giomodule.h"

#include "gioerror.h"

#include "giomodule-priv.h"

#include "gnetworkingprivate.h"

/**

 * SECTION:gproxyresolver

 * @short_description: Asynchronous and cancellable network proxy resolver

 * @include: gio/gio.h

 *

 * #GProxyResolver provides synchronous and asynchronous network proxy

 * resolution. #GProxyResolver is used within #GSocketClient through

 * the method g_socket_connectable_proxy_enumerate().

 *

 * Implementations of #GProxyResolver based on libproxy and GNOME settings can

 * be found in glib-networking. GIO comes with an implementation for use inside

 * Flatpak portals.

 */

/**

 * GProxyResolverInterface:

 * @g_iface: The parent interface.

 * @is_supported: the virtual function pointer for g_proxy_resolver_is_supported()

 * @lookup: the virtual function pointer for g_proxy_resolver_lookup()

 * @lookup_async: the virtual function pointer for

 *  g_proxy_resolver_lookup_async()

 * @lookup_finish: the virtual function pointer for

 *  g_proxy_resolver_lookup_finish()

 *

 * The virtual function table for #GProxyResolver.

 */

G_DEFINE_INTERFACE (GProxyResolver, g_proxy_resolver, G_TYPE_OBJECT)

static void

g_proxy_resolver_default_init (GProxyResolverInterface *iface)

{

}

static GProxyResolver *proxy_resolver_default_singleton = NULL;  /* (owned) (atomic) */

/**

 * g_proxy_resolver_get_default:

 *

 * Gets the default #GProxyResolver for the system.

 *

 * Returns: (not nullable) (transfer none): the default #GProxyResolver, which

 *     will be a dummy object if no proxy resolver is available

 *

 * Since: 2.26

 */

GProxyResolver *

g_proxy_resolver_get_default (void)

{

  if (g_once_init_enter (&proxy_resolver_default_singleton))

    {

      GProxyResolver *singleton;

      singleton = _g_io_module_get_default (G_PROXY_RESOLVER_EXTENSION_POINT_NAME,

                                            "GIO_USE_PROXY_RESOLVER",

                                            (GIOModuleVerifyFunc) g_proxy_resolver_is_supported);

      g_once_init_leave (&proxy_resolver_default_singleton, singleton);

    }

  return proxy_resolver_default_singleton;

}

/**

 * g_proxy_resolver_is_supported:

 * @resolver: a #GProxyResolver

 *

 * Checks if @resolver can be used on this system. (This is used

 * internally; g_proxy_resolver_get_default() will only return a proxy

 * resolver that returns %TRUE for this method.)

 *

 * Returns: %TRUE if @resolver is supported.

 *

 * Since: 2.26

 */

gboolean

g_proxy_resolver_is_supported (GProxyResolver *resolver)

{

  GProxyResolverInterface *iface;

  g_return_val_if_fail (G_IS_PROXY_RESOLVER (resolver), FALSE);

  iface = G_PROXY_RESOLVER_GET_IFACE (resolver);

  return (* iface->is_supported) (resolver);

}

/**

 * g_proxy_resolver_lookup:

 * @resolver: a #GProxyResolver

 * @uri: a URI representing the destination to connect to

 * @cancellable: (nullable): a #GCancellable, or %NULL

 * @error: return location for a #GError, or %NULL

 *

 * Looks into the system proxy configuration to determine what proxy,

 * if any, to use to connect to @uri. The returned proxy URIs are of

 * the form `<protocol>://[user[:password]@]host[:port]` or

 * `direct://`, where <protocol> could be http, rtsp, socks

 * or other proxying protocol.

 *

 * If you don't know what network protocol is being used on the

 * socket, you should use `none` as the URI protocol.

 * In this case, the resolver might still return a generic proxy type

 * (such as SOCKS), but would not return protocol-specific proxy types

 * (such as http).

 *

 * `direct://` is used when no proxy is needed.

 * Direct connection should not be attempted unless it is part of the

 * returned array of proxies.

 *

 * Returns: (transfer full) (array zero-terminated=1): A

 *               NULL-terminated array of proxy URIs. Must be freed

 *               with g_strfreev().

 *

 * Since: 2.26

 */

gchar **

g_proxy_resolver_lookup (GProxyResolver  *resolver,

       const gchar     *uri,

       GCancellable    *cancellable,

       GError         **error)

{

  GProxyResolverInterface *iface;

  gchar **proxy_uris;

  g_return_val_if_fail (G_IS_PROXY_RESOLVER (resolver), NULL);

  g_return_val_if_fail (uri != NULL, NULL);

  if (!g_uri_is_valid (uri, G_URI_FLAGS_NONE, NULL))

    {

      g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,

                   "Invalid URI ‘%s’", uri);

      return NULL;

    }

  iface = G_PROXY_RESOLVER_GET_IFACE (resolver);

  proxy_uris = (* iface->lookup) (resolver, uri, cancellable, error);

  if (proxy_uris == NULL && error != NULL)

    g_assert (*error != NULL);

  return proxy_uris;

}

/**

 * g_proxy_resolver_lookup_async:

 * @resolver: a #GProxyResolver

 * @uri: a URI representing the destination to connect to

 * @cancellable: (nullable): a #GCancellable, or %NULL

 * @callback: (scope async): callback to call after resolution completes

 * @user_data: data for @callback

 *

 * Asynchronous lookup of proxy. See g_proxy_resolver_lookup() for more

 * details.

 *

 * Since: 2.26

 */

void

g_proxy_resolver_lookup_async (GProxyResolver      *resolver,

             const gchar         *uri,

             GCancellable        *cancellable,

             GAsyncReadyCallback  callback,

             gpointer             user_data)

{

  GProxyResolverInterface *iface;

  GError *error = NULL;

  g_return_if_fail (G_IS_PROXY_RESOLVER (resolver));

  g_return_if_fail (uri != NULL);

  if (!g_uri_is_valid (uri, G_URI_FLAGS_NONE, NULL))

    {

      g_set_error (&error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,

                   "Invalid URI ‘%s’", uri);

      g_task_report_error (resolver, callback, user_data,

                           g_proxy_resolver_lookup_async,

                           g_steal_pointer (&error));

      return;

    }

  iface = G_PROXY_RESOLVER_GET_IFACE (resolver);

  (* iface->lookup_async) (resolver, uri, cancellable, callback, user_data);

}

/**

 * g_proxy_resolver_lookup_finish:

 * @resolver: a #GProxyResolver

 * @result: the result passed to your #GAsyncReadyCallback

 * @error: return location for a #GError, or %NULL

 *

 * Call this function to obtain the array of proxy URIs when

 * g_proxy_resolver_lookup_async() is complete. See

 * g_proxy_resolver_lookup() for more details.

 *

 * Returns: (transfer full) (array zero-terminated=1): A

 *               NULL-terminated array of proxy URIs. Must be freed

 *               with g_strfreev().

 *

 * Since: 2.26

 */

gchar **

g_proxy_resolver_lookup_finish (GProxyResolver     *resolver,

        GAsyncResult       *result,

        GError            **error)

{

  GProxyResolverInterface *iface;

  gchar **proxy_uris;

  g_return_val_if_fail (G_IS_PROXY_RESOLVER (resolver), NULL);

  if (g_async_result_is_tagged (result, g_proxy_resolver_lookup_async))

    return g_task_propagate_pointer (G_TASK (result), error);

  iface = G_PROXY_RESOLVER_GET_IFACE (resolver);

  proxy_uris = (* iface->lookup_finish) (resolver, result, error);

  if (proxy_uris == NULL && error != NULL)

    g_assert (*error != NULL);

  return proxy_uris;

}