malcontent/libmalcontent/session-limits.c

621 lines
20 KiB
C
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
*
* Copyright © 2019 Endless Mobile, Inc.
*
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors:
* - Philip Withnall <withnall@endlessm.com>
*/
#include "config.h"
#include <glib.h>
#include <glib-object.h>
#include <glib/gi18n-lib.h>
#include <gio/gio.h>
#include <libmalcontent/manager.h>
#include <libmalcontent/session-limits.h>
#include "libmalcontent/session-limits-private.h"
/* struct _MctSessionLimits is defined in session-limits-private.h */
G_DEFINE_BOXED_TYPE (MctSessionLimits, mct_session_limits,
mct_session_limits_ref, mct_session_limits_unref)
/**
* mct_session_limits_ref:
* @limits: (transfer none): an #MctSessionLimits
*
* Increment the reference count of @limits, and return the same pointer to it.
*
* Returns: (transfer full): the same pointer as @limits
* Since: 0.5.0
*/
MctSessionLimits *
mct_session_limits_ref (MctSessionLimits *limits)
{
g_return_val_if_fail (limits != NULL, NULL);
g_return_val_if_fail (limits->ref_count >= 1, NULL);
g_return_val_if_fail (limits->ref_count <= G_MAXINT - 1, NULL);
limits->ref_count++;
return limits;
}
/**
* mct_session_limits_unref:
* @limits: (transfer full): an #MctSessionLimits
*
* Decrement the reference count of @limits. If the reference count reaches
* zero, free the @limits and all its resources.
*
* Since: 0.5.0
*/
void
mct_session_limits_unref (MctSessionLimits *limits)
{
g_return_if_fail (limits != NULL);
g_return_if_fail (limits->ref_count >= 1);
limits->ref_count--;
if (limits->ref_count <= 0)
{
g_free (limits);
}
}
/**
* mct_session_limits_get_user_id:
* @limits: an #MctSessionLimits
*
* Get the user ID of the user this #MctSessionLimits is for.
*
* Returns: user ID of the relevant user, or `(uid_t) -1` if unknown
* Since: 0.5.0
*/
uid_t
mct_session_limits_get_user_id (MctSessionLimits *limits)
{
g_return_val_if_fail (limits != NULL, (uid_t) -1);
g_return_val_if_fail (limits->ref_count >= 1, (uid_t) -1);
return limits->user_id;
}
/**
* mct_session_limits_is_enabled:
* @limits: an #MctSessionLimits
*
* Check whether any session limits are enabled and are going to impose at least
* one restriction on the user. This gives a high level view of whether session
* limit parental controls are enabled for the given user.
*
* This function is equivalent to the value returned by the
* `time_limit_enabled_out` argument of
* mct_session_limits_check_time_remaining().
*
* Returns: %TRUE if the session limits object contains at least one restrictive
* session limit, %FALSE if there are no limits in place
* Since: 0.7.0
*/
gboolean
mct_session_limits_is_enabled (MctSessionLimits *limits)
{
g_return_val_if_fail (limits != NULL, FALSE);
g_return_val_if_fail (limits->ref_count >= 1, FALSE);
return (limits->limit_type != MCT_SESSION_LIMITS_TYPE_NONE);
}
/**
* mct_session_limits_check_time_remaining:
* @limits: an #MctSessionLimits
* @now_usecs: current time as microseconds since the Unix epoch (UTC),
* typically queried using g_get_real_time()
* @time_remaining_secs_out: (out) (optional): return location for the number
* of seconds remaining before the users session has to end, if limits are
* in force
* @time_limit_enabled_out: (out) (optional): return location for whether time
* limits are enabled for this user
*
* Check whether the user has time remaining in which they are allowed to use
* the computer, assuming that @now_usecs is the current time, and applying the
* session limit policy from @limits to it.
*
* This will return whether the user is allowed to use the computer now; further
* information about the policy and remaining time is provided in
* @time_remaining_secs_out and @time_limit_enabled_out.
*
* Returns: %TRUE if the user this @limits corresponds to is allowed to be in
* an active session at the given time; %FALSE otherwise
* Since: 0.5.0
*/
gboolean
mct_session_limits_check_time_remaining (MctSessionLimits *limits,
guint64 now_usecs,
guint64 *time_remaining_secs_out,
gboolean *time_limit_enabled_out)
{
guint64 time_remaining_secs;
gboolean time_limit_enabled;
gboolean user_allowed_now;
g_autoptr(GDateTime) now_dt = NULL;
guint64 now_time_of_day_secs;
g_return_val_if_fail (limits != NULL, FALSE);
g_return_val_if_fail (limits->ref_count >= 1, FALSE);
/* Helper calculations. */
now_dt = g_date_time_new_from_unix_utc (now_usecs / G_USEC_PER_SEC);
if (now_dt == NULL)
{
time_remaining_secs = 0;
time_limit_enabled = TRUE;
user_allowed_now = FALSE;
goto out;
}
now_time_of_day_secs = ((g_date_time_get_hour (now_dt) * 60 +
g_date_time_get_minute (now_dt)) * 60 +
g_date_time_get_second (now_dt));
/* Work out the limits. */
switch (limits->limit_type)
{
case MCT_SESSION_LIMITS_TYPE_DAILY_SCHEDULE:
user_allowed_now = (now_time_of_day_secs >= limits->daily_start_time &&
now_time_of_day_secs < limits->daily_end_time);
time_remaining_secs = user_allowed_now ? (limits->daily_end_time - now_time_of_day_secs) : 0;
time_limit_enabled = TRUE;
g_debug ("%s: Daily schedule limit allowed in %u%u (now is %"
G_GUINT64_FORMAT "); %" G_GUINT64_FORMAT " seconds remaining",
G_STRFUNC, limits->daily_start_time, limits->daily_end_time,
now_time_of_day_secs, time_remaining_secs);
break;
case MCT_SESSION_LIMITS_TYPE_NONE:
default:
user_allowed_now = TRUE;
time_remaining_secs = G_MAXUINT64;
time_limit_enabled = FALSE;
g_debug ("%s: No limit enabled", G_STRFUNC);
break;
}
out:
/* Postconditions. */
g_assert (!user_allowed_now || time_remaining_secs > 0);
g_assert (user_allowed_now || time_remaining_secs == 0);
g_assert (time_limit_enabled || time_remaining_secs == G_MAXUINT64);
/* Output. */
if (time_remaining_secs_out != NULL)
*time_remaining_secs_out = time_remaining_secs;
if (time_limit_enabled_out != NULL)
*time_limit_enabled_out = time_limit_enabled;
return user_allowed_now;
}
/**
* mct_session_limits_serialize:
* @limits: an #MctSessionLimits
*
* Build a #GVariant which contains the session limits from @limits, in an
* opaque variant format. This format may change in future, but
* mct_session_limits_deserialize() is guaranteed to always be able to load any
* variant produced by the current or any previous version of
* mct_session_limits_serialize().
*
* Returns: (transfer floating): a new, floating #GVariant containing the
* session limits
* Since: 0.7.0
*/
GVariant *
mct_session_limits_serialize (MctSessionLimits *limits)
{
g_auto(GVariantBuilder) builder = G_VARIANT_BUILDER_INIT (G_VARIANT_TYPE ("a{sv}"));
g_autoptr(GVariant) limit_variant = NULL;
const gchar *limit_property_name;
g_return_val_if_fail (limits != NULL, NULL);
g_return_val_if_fail (limits->ref_count >= 1, NULL);
/* The serialisation format is exactly the
* `com.endlessm.ParentalControls.SessionLimits` D-Bus interface. */
switch (limits->limit_type)
{
case MCT_SESSION_LIMITS_TYPE_DAILY_SCHEDULE:
limit_variant = g_variant_new ("(uu)",
limits->daily_start_time,
limits->daily_end_time);
limit_property_name = "DailySchedule";
break;
case MCT_SESSION_LIMITS_TYPE_NONE:
limit_variant = NULL;
limit_property_name = NULL;
break;
default:
g_assert_not_reached ();
}
if (limit_property_name != NULL)
{
g_variant_builder_add (&builder, "{sv}", limit_property_name,
g_steal_pointer (&limit_variant));
}
g_variant_builder_add (&builder, "{sv}", "LimitType",
g_variant_new_uint32 (limits->limit_type));
return g_variant_builder_end (&builder);
}
/**
* mct_session_limits_deserialize:
* @variant: a serialized session limits variant
* @user_id: the ID of the user the session limits relate to
* @error: return location for a #GError, or %NULL
*
* Deserialize a set of session limits previously serialized with
* mct_session_limits_serialize(). This function guarantees to be able to
* deserialize any serialized form from this version or older versions of
* libmalcontent.
*
* If deserialization fails, %MCT_MANAGER_ERROR_INVALID_DATA will be returned.
*
* Returns: (transfer full): deserialized session limits
* Since: 0.7.0
*/
MctSessionLimits *
mct_session_limits_deserialize (GVariant *variant,
uid_t user_id,
GError **error)
{
g_autoptr(MctSessionLimits) session_limits = NULL;
guint32 limit_type;
guint32 daily_start_time, daily_end_time;
g_return_val_if_fail (variant != NULL, NULL);
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
/* Check the overall type. */
if (!g_variant_is_of_type (variant, G_VARIANT_TYPE ("a{sv}")))
{
g_set_error (error, MCT_MANAGER_ERROR,
MCT_MANAGER_ERROR_INVALID_DATA,
_("Session limit for user %u was in an unrecognized format"),
(guint) user_id);
return NULL;
}
/* Extract the properties we care about. The default values here should be
* kept in sync with those in the `com.endlessm.ParentalControls.SessionLimits`
* D-Bus interface. */
if (!g_variant_lookup (variant, "LimitType", "u",
&limit_type))
{
/* Default value. */
limit_type = MCT_SESSION_LIMITS_TYPE_NONE;
}
/* Check that the limit type is something we support. */
G_STATIC_ASSERT (sizeof (limit_type) >= sizeof (MctSessionLimitsType));
if ((guint) limit_type > MCT_SESSION_LIMITS_TYPE_DAILY_SCHEDULE)
{
g_set_error (error, MCT_MANAGER_ERROR,
MCT_MANAGER_ERROR_INVALID_DATA,
_("Session limit for user %u has an unrecognized type %u"),
(guint) user_id, limit_type);
return NULL;
}
if (!g_variant_lookup (variant, "DailySchedule", "(uu)",
&daily_start_time, &daily_end_time))
{
/* Default value. */
daily_start_time = 0;
daily_end_time = 24 * 60 * 60;
}
if (daily_start_time >= daily_end_time ||
daily_end_time > 24 * 60 * 60)
{
g_set_error (error, MCT_MANAGER_ERROR,
MCT_MANAGER_ERROR_INVALID_DATA,
_("Session limit for user %u has invalid daily schedule %u%u"),
(guint) user_id, daily_start_time, daily_end_time);
return NULL;
}
/* Success. Create an #MctSessionLimits object to contain the results. */
session_limits = g_new0 (MctSessionLimits, 1);
session_limits->ref_count = 1;
session_limits->user_id = user_id;
session_limits->limit_type = limit_type;
session_limits->daily_start_time = daily_start_time;
session_limits->daily_end_time = daily_end_time;
return g_steal_pointer (&session_limits);
}
/*
* Actual implementation of #MctSessionLimitsBuilder.
*
* All members are %NULL if un-initialised, cleared, or ended.
*/
typedef struct
{
MctSessionLimitsType limit_type;
/* Which member is used is determined by @limit_type: */
union
{
struct
{
guint start_time; /* seconds since midnight */
guint end_time; /* seconds since midnight */
} daily_schedule;
};
/*< private >*/
gpointer padding[10];
} MctSessionLimitsBuilderReal;
G_STATIC_ASSERT (sizeof (MctSessionLimitsBuilderReal) ==
sizeof (MctSessionLimitsBuilder));
G_STATIC_ASSERT (__alignof__ (MctSessionLimitsBuilderReal) ==
__alignof__ (MctSessionLimitsBuilder));
G_DEFINE_BOXED_TYPE (MctSessionLimitsBuilder, mct_session_limits_builder,
mct_session_limits_builder_copy, mct_session_limits_builder_free)
/**
* mct_session_limits_builder_init:
* @builder: an uninitialised #MctSessionLimitsBuilder
*
* Initialise the given @builder so it can be used to construct a new
* #MctSessionLimits. @builder must have been allocated on the stack, and must
* not already be initialised.
*
* Construct the #MctSessionLimits by calling methods on @builder, followed by
* mct_session_limits_builder_end(). To abort construction, use
* mct_session_limits_builder_clear().
*
* Since: 0.5.0
*/
void
mct_session_limits_builder_init (MctSessionLimitsBuilder *builder)
{
MctSessionLimitsBuilder local_builder = MCT_SESSION_LIMITS_BUILDER_INIT ();
MctSessionLimitsBuilderReal *_builder = (MctSessionLimitsBuilderReal *) builder;
g_return_if_fail (_builder != NULL);
g_return_if_fail (_builder->limit_type == MCT_SESSION_LIMITS_TYPE_NONE);
memcpy (builder, &local_builder, sizeof (local_builder));
}
/**
* mct_session_limits_builder_clear:
* @builder: an #MctSessionLimitsBuilder
*
* Clear @builder, freeing any internal state in it. This will not free the
* top-level storage for @builder itself, which is assumed to be allocated on
* the stack.
*
* If called on an already-cleared #MctSessionLimitsBuilder, this function is
* idempotent.
*
* Since: 0.5.0
*/
void
mct_session_limits_builder_clear (MctSessionLimitsBuilder *builder)
{
MctSessionLimitsBuilderReal *_builder = (MctSessionLimitsBuilderReal *) builder;
g_return_if_fail (_builder != NULL);
/* Nothing to free here for now. */
_builder->limit_type = MCT_SESSION_LIMITS_TYPE_NONE;
}
/**
* mct_session_limits_builder_new:
*
* Construct a new #MctSessionLimitsBuilder on the heap. This is intended for
* language bindings. The returned builder must eventually be freed with
* mct_session_limits_builder_free(), but can be cleared zero or more times with
* mct_session_limits_builder_clear() first.
*
* Returns: (transfer full): a new heap-allocated #MctSessionLimitsBuilder
* Since: 0.5.0
*/
MctSessionLimitsBuilder *
mct_session_limits_builder_new (void)
{
g_autoptr(MctSessionLimitsBuilder) builder = NULL;
builder = g_new0 (MctSessionLimitsBuilder, 1);
mct_session_limits_builder_init (builder);
return g_steal_pointer (&builder);
}
/**
* mct_session_limits_builder_copy:
* @builder: an #MctSessionLimitsBuilder
*
* Copy the given @builder to a newly-allocated #MctSessionLimitsBuilder on the
* heap. This is safe to use with cleared, stack-allocated
* #MctSessionLimitsBuilders.
*
* Returns: (transfer full): a copy of @builder
* Since: 0.5.0
*/
MctSessionLimitsBuilder *
mct_session_limits_builder_copy (MctSessionLimitsBuilder *builder)
{
MctSessionLimitsBuilderReal *_builder = (MctSessionLimitsBuilderReal *) builder;
g_autoptr(MctSessionLimitsBuilder) copy = NULL;
MctSessionLimitsBuilderReal *_copy;
g_return_val_if_fail (builder != NULL, NULL);
copy = mct_session_limits_builder_new ();
_copy = (MctSessionLimitsBuilderReal *) copy;
mct_session_limits_builder_clear (copy);
_copy->limit_type = _builder->limit_type;
switch (_builder->limit_type)
{
case MCT_SESSION_LIMITS_TYPE_DAILY_SCHEDULE:
_copy->daily_schedule.start_time = _builder->daily_schedule.start_time;
_copy->daily_schedule.end_time = _builder->daily_schedule.end_time;
break;
case MCT_SESSION_LIMITS_TYPE_NONE:
default:
break;
}
return g_steal_pointer (&copy);
}
/**
* mct_session_limits_builder_free:
* @builder: a heap-allocated #MctSessionLimitsBuilder
*
* Free an #MctSessionLimitsBuilder originally allocated using
* mct_session_limits_builder_new(). This must not be called on stack-allocated
* builders initialised using mct_session_limits_builder_init().
*
* Since: 0.5.0
*/
void
mct_session_limits_builder_free (MctSessionLimitsBuilder *builder)
{
g_return_if_fail (builder != NULL);
mct_session_limits_builder_clear (builder);
g_free (builder);
}
/**
* mct_session_limits_builder_end:
* @builder: an initialised #MctSessionLimitsBuilder
*
* Finish constructing an #MctSessionLimits with the given @builder, and return
* it. The #MctSessionLimitsBuilder will be cleared as if
* mct_session_limits_builder_clear() had been called.
*
* Returns: (transfer full): a newly constructed #MctSessionLimits
* Since: 0.5.0
*/
MctSessionLimits *
mct_session_limits_builder_end (MctSessionLimitsBuilder *builder)
{
MctSessionLimitsBuilderReal *_builder = (MctSessionLimitsBuilderReal *) builder;
g_autoptr(MctSessionLimits) session_limits = NULL;
g_return_val_if_fail (_builder != NULL, NULL);
/* Build the #MctSessionLimits. */
session_limits = g_new0 (MctSessionLimits, 1);
session_limits->ref_count = 1;
session_limits->user_id = -1;
session_limits->limit_type = _builder->limit_type;
switch (_builder->limit_type)
{
case MCT_SESSION_LIMITS_TYPE_DAILY_SCHEDULE:
session_limits->daily_start_time = _builder->daily_schedule.start_time;
session_limits->daily_end_time = _builder->daily_schedule.end_time;
break;
case MCT_SESSION_LIMITS_TYPE_NONE:
default:
/* Defaults: */
session_limits->daily_start_time = 0;
session_limits->daily_end_time = 24 * 60 * 60;
break;
}
mct_session_limits_builder_clear (builder);
return g_steal_pointer (&session_limits);
}
/**
* mct_session_limits_builder_set_none:
* @builder: an initialised #MctSessionLimitsBuilder
*
* Unset any session limits currently set in the @builder.
*
* Since: 0.5.0
*/
void
mct_session_limits_builder_set_none (MctSessionLimitsBuilder *builder)
{
MctSessionLimitsBuilderReal *_builder = (MctSessionLimitsBuilderReal *) builder;
g_return_if_fail (_builder != NULL);
/* This will need to free other limit types data first in future. */
_builder->limit_type = MCT_SESSION_LIMITS_TYPE_NONE;
}
/**
* mct_session_limits_builder_set_daily_schedule:
* @builder: an initialised #MctSessionLimitsBuilder
* @start_time_secs: number of seconds since midnight when the users session
* can first start
* @end_time_secs: number of seconds since midnight when the users session can
* last end
*
* Set the session limits in @builder to be a daily schedule, where sessions are
* allowed between @start_time_secs and @end_time_secs every day.
* @start_time_secs and @end_time_secs are given as offsets from the start of
* the day, in seconds. @end_time_secs must be greater than @start_time_secs.
* @end_time_secs must be at most `24 * 60 * 60`.
*
* This will overwrite any other session limits.
*
* Since: 0.5.0
*/
void
mct_session_limits_builder_set_daily_schedule (MctSessionLimitsBuilder *builder,
guint start_time_secs,
guint end_time_secs)
{
MctSessionLimitsBuilderReal *_builder = (MctSessionLimitsBuilderReal *) builder;
g_return_if_fail (_builder != NULL);
g_return_if_fail (start_time_secs < end_time_secs);
g_return_if_fail (end_time_secs <= 24 * 60 * 60);
/* This will need to free other limit types data first in future. */
_builder->limit_type = MCT_SESSION_LIMITS_TYPE_DAILY_SCHEDULE;
_builder->daily_schedule.start_time = start_time_secs;
_builder->daily_schedule.end_time = end_time_secs;
}