glib/gio/gtlsinteraction.c

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/* GIO - GLib Input, Output and Streaming Library
*
* Copyright (C) 2011 Collabora, Ltd.
*
* 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 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, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*
* Author: Stef Walter <stefw@collabora.co.uk>
*/
#include "config.h"
#include <string.h>
#include "gtlsinteraction.h"
#include "gtlspassword.h"
#include "gasyncresult.h"
#include "gcancellable.h"
#include "gtask.h"
#include "gioenumtypes.h"
#include "glibintl.h"
/**
* SECTION:gtlsinteraction
* @short_description: Interaction with the user during TLS operations.
* @include: gio/gio.h
*
* #GTlsInteraction provides a mechanism for the TLS connection and database
* code to interact with the user. It can be used to ask the user for passwords.
*
* To use a #GTlsInteraction with a TLS connection use
* g_tls_connection_set_interaction().
*
* Callers should instantiate a derived class that implements the various
* interaction methods to show the required dialogs.
*
* Callers should use the 'invoke' functions like
* g_tls_interaction_invoke_ask_password() to run interaction methods. These
* functions make sure that the interaction is invoked in the main loop
* and not in the current thread, if the current thread is not running the
* main loop.
*
* Derived classes can choose to implement whichever interactions methods they'd
* like to support by overriding those virtual methods in their class
* initialization function. Any interactions not implemented will return
* %G_TLS_INTERACTION_UNHANDLED. If a derived class implements an async method,
* it must also implement the corresponding finish method.
*/
/**
* GTlsInteraction:
*
* An object representing interaction that the TLS connection and database
* might have with the user.
*
* Since: 2.30
*/
/**
* GTlsInteractionClass:
* @ask_password: ask for a password synchronously. If the implementation
* returns %G_TLS_INTERACTION_HANDLED, then the password argument should
* have been filled in by using g_tls_password_set_value() or a similar
* function.
* @ask_password_async: ask for a password asynchronously.
* @ask_password_finish: complete operation to ask for a password asynchronously.
* If the implementation returns %G_TLS_INTERACTION_HANDLED, then the
* password argument of the async method should have been filled in by using
* g_tls_password_set_value() or a similar function.
*
* The class for #GTlsInteraction. Derived classes implement the various
* virtual interaction methods to handle TLS interactions.
*
* Derived classes can choose to implement whichever interactions methods they'd
* like to support by overriding those virtual methods in their class
* initialization function. If a derived class implements an async method,
* it must also implement the corresponding finish method.
*
* The synchronous interaction methods should implement to display modal dialogs,
* and the asynchronous methods to display modeless dialogs.
*
* If the user cancels an interaction, then the result should be
* %G_TLS_INTERACTION_FAILED and the error should be set with a domain of
* %G_IO_ERROR and code of %G_IO_ERROR_CANCELLED.
*
* Since: 2.30
*/
struct _GTlsInteractionPrivate {
GMainContext *context;
};
G_DEFINE_TYPE_WITH_PRIVATE (GTlsInteraction, g_tls_interaction, G_TYPE_OBJECT)
typedef struct {
GMutex mutex;
/* Input arguments */
GTlsInteraction *interaction;
GObject *argument;
GCancellable *cancellable;
/* Used when we're invoking async interactions */
GAsyncReadyCallback callback;
gpointer user_data;
/* Used when we expect results */
GTlsInteractionResult result;
GError *error;
gboolean complete;
GCond cond;
} InvokeClosure;
static void
invoke_closure_free (gpointer data)
{
InvokeClosure *closure = data;
g_assert (closure);
g_object_unref (closure->interaction);
g_clear_object (&closure->argument);
g_clear_object (&closure->cancellable);
g_cond_clear (&closure->cond);
g_mutex_clear (&closure->mutex);
g_clear_error (&closure->error);
/* Insurance that we've actually used these before freeing */
g_assert (closure->callback == NULL);
g_assert (closure->user_data == NULL);
g_free (closure);
}
static InvokeClosure *
invoke_closure_new (GTlsInteraction *interaction,
GObject *argument,
GCancellable *cancellable)
{
InvokeClosure *closure = g_new0 (InvokeClosure, 1);
closure->interaction = g_object_ref (interaction);
closure->argument = argument ? g_object_ref (argument) : NULL;
closure->cancellable = cancellable ? g_object_ref (cancellable) : NULL;
g_mutex_init (&closure->mutex);
g_cond_init (&closure->cond);
closure->result = G_TLS_INTERACTION_UNHANDLED;
return closure;
}
static GTlsInteractionResult
invoke_closure_wait_and_free (InvokeClosure *closure,
GError **error)
{
GTlsInteractionResult result;
g_mutex_lock (&closure->mutex);
while (!closure->complete)
g_cond_wait (&closure->cond, &closure->mutex);
g_mutex_unlock (&closure->mutex);
if (closure->error)
{
g_propagate_error (error, closure->error);
closure->error = NULL;
}
result = closure->result;
invoke_closure_free (closure);
return result;
}
static void
g_tls_interaction_init (GTlsInteraction *interaction)
{
interaction->priv = g_tls_interaction_get_instance_private (interaction);
interaction->priv->context = g_main_context_ref_thread_default ();
}
static void
g_tls_interaction_finalize (GObject *object)
{
GTlsInteraction *interaction = G_TLS_INTERACTION (object);
g_main_context_unref (interaction->priv->context);
G_OBJECT_CLASS (g_tls_interaction_parent_class)->finalize (object);
}
static void
g_tls_interaction_class_init (GTlsInteractionClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->finalize = g_tls_interaction_finalize;
}
static gboolean
on_invoke_ask_password_sync (gpointer user_data)
{
InvokeClosure *closure = user_data;
GTlsInteractionClass *klass;
g_mutex_lock (&closure->mutex);
klass = G_TLS_INTERACTION_GET_CLASS (closure->interaction);
g_assert (klass->ask_password);
closure->result = klass->ask_password (closure->interaction,
G_TLS_PASSWORD (closure->argument),
closure->cancellable,
&closure->error);
closure->complete = TRUE;
g_cond_signal (&closure->cond);
g_mutex_unlock (&closure->mutex);
return FALSE; /* don't call again */
}
static void
on_async_as_sync_complete (GObject *source,
GAsyncResult *result,
gpointer user_data)
{
InvokeClosure *closure = user_data;
GTlsInteractionClass *klass;
g_mutex_lock (&closure->mutex);
klass = G_TLS_INTERACTION_GET_CLASS (closure->interaction);
g_assert (klass->ask_password_finish);
closure->result = klass->ask_password_finish (closure->interaction,
result,
&closure->error);
closure->complete = TRUE;
g_cond_signal (&closure->cond);
g_mutex_unlock (&closure->mutex);
}
static gboolean
on_invoke_ask_password_async_as_sync (gpointer user_data)
{
InvokeClosure *closure = user_data;
GTlsInteractionClass *klass;
g_mutex_lock (&closure->mutex);
klass = G_TLS_INTERACTION_GET_CLASS (closure->interaction);
g_assert (klass->ask_password_async);
klass->ask_password_async (closure->interaction,
G_TLS_PASSWORD (closure->argument),
closure->cancellable,
on_async_as_sync_complete,
closure);
/* Note that we've used these */
closure->callback = NULL;
closure->user_data = NULL;
g_mutex_unlock (&closure->mutex);
return FALSE; /* don't call again */
}
/**
* g_tls_interaction_invoke_ask_password:
* @interaction: a #GTlsInteraction object
* @password: a #GTlsPassword object
* @cancellable: an optional #GCancellable cancellation object
* @error: an optional location to place an error on failure
*
* Invoke the interaction to ask the user for a password. It invokes this
* interaction in the main loop, specifically the #GMainContext returned by
* g_main_context_get_thread_default() when the interaction is created. This
* is called by called by #GTlsConnection or #GTlsDatabase to ask the user
* for a password.
*
* Derived subclasses usually implement a password prompt, although they may
* also choose to provide a password from elsewhere. The @password value will
* be filled in and then @callback will be called. Alternatively the user may
* abort this password request, which will usually abort the TLS connection.
*
* The implementation can either be a synchronous (eg: modal dialog) or an
* asynchronous one (eg: modeless dialog). This function will take care of
* calling which ever one correctly.
*
* If the interaction is cancelled by the cancellation object, or by the
* user then %G_TLS_INTERACTION_FAILED will be returned with an error that
* contains a %G_IO_ERROR_CANCELLED error code. Certain implementations may
* not support immediate cancellation.
*
* Returns: The status of the ask password interaction.
*
* Since: 2.30
*/
GTlsInteractionResult
g_tls_interaction_invoke_ask_password (GTlsInteraction *interaction,
GTlsPassword *password,
GCancellable *cancellable,
GError **error)
{
GTlsInteractionResult result;
InvokeClosure *closure;
GTlsInteractionClass *klass;
gboolean complete;
g_return_val_if_fail (G_IS_TLS_INTERACTION (interaction), G_TLS_INTERACTION_UNHANDLED);
g_return_val_if_fail (G_IS_TLS_PASSWORD (password), G_TLS_INTERACTION_UNHANDLED);
g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable), G_TLS_INTERACTION_UNHANDLED);
closure = invoke_closure_new (interaction, G_OBJECT (password), cancellable);
klass = G_TLS_INTERACTION_GET_CLASS (interaction);
if (klass->ask_password)
{
g_main_context_invoke (interaction->priv->context,
on_invoke_ask_password_sync, closure);
result = invoke_closure_wait_and_free (closure, error);
}
else if (klass->ask_password_async)
{
g_return_val_if_fail (klass->ask_password_finish, G_TLS_INTERACTION_UNHANDLED);
g_main_context_invoke (interaction->priv->context,
on_invoke_ask_password_async_as_sync, closure);
/*
* Handle the case where we've been called from within the main context
* or in the case where the main context is not running. This approximates
* the behavior of a modal dialog.
*/
if (g_main_context_acquire (interaction->priv->context))
{
for (;;)
{
g_mutex_lock (&closure->mutex);
complete = closure->complete;
g_mutex_unlock (&closure->mutex);
if (complete)
break;
g_main_context_iteration (interaction->priv->context, TRUE);
}
g_main_context_release (interaction->priv->context);
if (closure->error)
{
g_propagate_error (error, closure->error);
closure->error = NULL;
}
result = closure->result;
invoke_closure_free (closure);
}
/*
* Handle the case where we're in a different thread than the main
* context and a main loop is running.
*/
else
{
result = invoke_closure_wait_and_free (closure, error);
}
}
else
{
result = G_TLS_INTERACTION_UNHANDLED;
invoke_closure_free (closure);
}
return result;
}
/**
* g_tls_interaction_ask_password:
* @interaction: a #GTlsInteraction object
* @password: a #GTlsPassword object
* @cancellable: an optional #GCancellable cancellation object
* @error: an optional location to place an error on failure
*
* Run synchronous interaction to ask the user for a password. In general,
* g_tls_interaction_invoke_ask_password() should be used instead of this
* function.
*
* Derived subclasses usually implement a password prompt, although they may
* also choose to provide a password from elsewhere. The @password value will
* be filled in and then @callback will be called. Alternatively the user may
* abort this password request, which will usually abort the TLS connection.
*
* If the interaction is cancelled by the cancellation object, or by the
* user then %G_TLS_INTERACTION_FAILED will be returned with an error that
* contains a %G_IO_ERROR_CANCELLED error code. Certain implementations may
* not support immediate cancellation.
*
* Returns: The status of the ask password interaction.
*
* Since: 2.30
*/
GTlsInteractionResult
g_tls_interaction_ask_password (GTlsInteraction *interaction,
GTlsPassword *password,
GCancellable *cancellable,
GError **error)
{
GTlsInteractionClass *klass;
g_return_val_if_fail (G_IS_TLS_INTERACTION (interaction), G_TLS_INTERACTION_UNHANDLED);
g_return_val_if_fail (G_IS_TLS_PASSWORD (password), G_TLS_INTERACTION_UNHANDLED);
g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable), G_TLS_INTERACTION_UNHANDLED);
klass = G_TLS_INTERACTION_GET_CLASS (interaction);
if (klass->ask_password)
return (klass->ask_password) (interaction, password, cancellable, error);
else
return G_TLS_INTERACTION_UNHANDLED;
}
/**
* g_tls_interaction_ask_password_async:
* @interaction: a #GTlsInteraction object
* @password: a #GTlsPassword object
* @cancellable: an optional #GCancellable cancellation object
* @callback: (allow-none): will be called when the interaction completes
* @user_data: (allow-none): data to pass to the @callback
*
* Run asynchronous interaction to ask the user for a password. In general,
* g_tls_interaction_invoke_ask_password() should be used instead of this
* function.
*
* Derived subclasses usually implement a password prompt, although they may
* also choose to provide a password from elsewhere. The @password value will
* be filled in and then @callback will be called. Alternatively the user may
* abort this password request, which will usually abort the TLS connection.
*
* If the interaction is cancelled by the cancellation object, or by the
* user then %G_TLS_INTERACTION_FAILED will be returned with an error that
* contains a %G_IO_ERROR_CANCELLED error code. Certain implementations may
* not support immediate cancellation.
*
* Certain implementations may not support immediate cancellation.
*
* Since: 2.30
*/
void
g_tls_interaction_ask_password_async (GTlsInteraction *interaction,
GTlsPassword *password,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
GTlsInteractionClass *klass;
GTask *task;
g_return_if_fail (G_IS_TLS_INTERACTION (interaction));
g_return_if_fail (G_IS_TLS_PASSWORD (password));
g_return_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable));
klass = G_TLS_INTERACTION_GET_CLASS (interaction);
if (klass->ask_password_async)
{
g_return_if_fail (klass->ask_password_finish);
(klass->ask_password_async) (interaction, password, cancellable,
callback, user_data);
}
else
{
task = g_task_new (interaction, cancellable, callback, user_data);
g_task_set_source_tag (task, g_tls_interaction_ask_password_async);
g_task_return_int (task, G_TLS_INTERACTION_UNHANDLED);
g_object_unref (task);
}
}
/**
* g_tls_interaction_ask_password_finish:
* @interaction: a #GTlsInteraction object
* @result: the result passed to the callback
* @error: an optional location to place an error on failure
*
* Complete an ask password user interaction request. This should be once
* the g_tls_interaction_ask_password_async() completion callback is called.
*
* If %G_TLS_INTERACTION_HANDLED is returned, then the #GTlsPassword passed
* to g_tls_interaction_ask_password() will have its password filled in.
*
* If the interaction is cancelled by the cancellation object, or by the
* user then %G_TLS_INTERACTION_FAILED will be returned with an error that
* contains a %G_IO_ERROR_CANCELLED error code.
*
* Returns: The status of the ask password interaction.
*
* Since: 2.30
*/
GTlsInteractionResult
g_tls_interaction_ask_password_finish (GTlsInteraction *interaction,
GAsyncResult *result,
GError **error)
{
GTlsInteractionClass *klass;
g_return_val_if_fail (G_IS_TLS_INTERACTION (interaction), G_TLS_INTERACTION_UNHANDLED);
g_return_val_if_fail (G_IS_ASYNC_RESULT (result), G_TLS_INTERACTION_UNHANDLED);
klass = G_TLS_INTERACTION_GET_CLASS (interaction);
if (klass->ask_password_finish)
{
g_return_val_if_fail (klass->ask_password_async != NULL, G_TLS_INTERACTION_UNHANDLED);
return (klass->ask_password_finish) (interaction, result, error);
}
else
{
g_return_val_if_fail (g_async_result_is_tagged (result, g_tls_interaction_ask_password_async), G_TLS_INTERACTION_UNHANDLED);
return g_task_propagate_int (G_TASK (result), error);
}
}