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References: <20200622234051.206800-1-abhishekpandit@chromium.org> <20200622164003.BlueZ.v5.3.I1b0ff04f458fdaec2a193d27c2b94ce8f2cc4138@changeid>
In-Reply-To: <20200622164003.BlueZ.v5.3.I1b0ff04f458fdaec2a193d27c2b94ce8f2cc4138@changeid>
From:   Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Date:   Mon, 22 Jun 2020 17:10:55 -0700
Message-ID: <CABBYNZKvDtAM4CjQ1=Dwt8jbUU3r2m0V1uNxD3ZL9Mi2EpC2LQ@mail.gmail.com>
Subject: Re: [BlueZ PATCH v5 3/6] device: Support marking a device with wake allowed
To:     Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Cc:     "linux-bluetooth@vger.kernel.org" <linux-bluetooth@vger.kernel.org>,
        Alain Michaud <alainm@chromium.org>,
        Marcel Holtmann <marcel@holtmann.org>,
        ChromeOS Bluetooth Upstreaming 
        <chromeos-bluetooth-upstreaming@chromium.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-bluetooth-owner@vger.kernel.org
Precedence: bulk

Hi Abhishek,

On Mon, Jun 22, 2020 at 4:41 PM Abhishek Pandit-Subedi
<abhishekpandit@chromium.org> wrote:
>
> If a device is allowed to wake the host system from suspend, it should
> be marked as wake allowed. We add support for a new property that is
> sent to the kernel via set device flags mgmt op. We also add the dbus
> endpoint to allow the wake allowed setting to be controlled.
>
> In order for wake allowed to be set, the profile must also support wake.
> This setting isn't exposed to the user but must be set by profiles that
> intend to support wake from suspend.
>
> If a device is connecting for the first time, it will be marked
> WakeAllowed if the profile supports it. On subsequent reloads of bluez,
> the stored setting "WakeAllowed" will be used to override any other
> setting.
>
> ---
>
> Changes in v5:
> * Refactor to use set_wake_flags and respond to device flags changed
> * Add wake_override so we can keep track of user/profile configuration
>   vs what is currently active
>
> Changes in v4:
> * Renamed wake_capable to wake_allowed
> * Removed set_wake_capable mgmt op and updated add_device to accept
>   flags to set whether a device is wakeable
> * Refactored adapter_whitelist_add and adapter_auto_connect_add to call
>   adapter_add_device
>
> Changes in v3:
> * Added profile_wake_support and made wake_capable dependent on it
>
> Changes in v2:
> * Added dbus api "WakeCapable" to set value
> * Update device_set_wake_capable to be called by
>   adapter_set_wake_capable_complete so we can emit property changed
>
>  lib/mgmt.h    |   2 +
>  src/adapter.c |  98 +++++++++++++++++++++++++++
>  src/adapter.h |   3 +-
>  src/device.c  | 184 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  src/device.h  |   9 +++
>  5 files changed, 295 insertions(+), 1 deletion(-)
>
> diff --git a/lib/mgmt.h b/lib/mgmt.h
> index 525c4dd62..a800bcab4 100644
> --- a/lib/mgmt.h
> +++ b/lib/mgmt.h
> @@ -665,6 +665,8 @@ struct mgmt_rp_get_device_flags {
>         uint32_t current_flags;
>  } __packed;
>
> +#define DEVICE_FLAG_REMOTE_WAKEUP      (1 << 0)
> +
>  #define MGMT_OP_SET_DEVICE_FLAGS       0x0050
>  #define MGMT_SET_DEVICE_FLAGS_SIZE     11
>  struct mgmt_cp_set_device_flags {
> diff --git a/src/adapter.c b/src/adapter.c
> index 9ce351893..0ab1f85a8 100644
> --- a/src/adapter.c
> +++ b/src/adapter.c
> @@ -5102,6 +5102,99 @@ void adapter_auto_connect_add(struct btd_adapter *adapter,
>         adapter->connect_list = g_slist_append(adapter->connect_list, device);
>  }
>
> +static void set_device_wakeable_complete(uint8_t status, uint16_t length,
> +                                        const void *param, void *user_data)
> +{
> +       const struct mgmt_rp_set_device_flags *rp = param;
> +       struct btd_adapter *adapter = user_data;
> +       struct btd_device *dev;
> +       char addr[18];
> +
> +       if (status != MGMT_STATUS_SUCCESS) {
> +               btd_error(adapter->dev_id, "Set device flags return status: %s",
> +                         mgmt_errstr(status));

Should you return here, or just move the other if statement down this
function here since it seems a little pointless to try to find the
device if the status is an error, that said perhaps we do indeed need
to notify the status on complete so we can actually report back to the
D-Bus client if it cannot be set, apparently this cannot fail now it
seems to be wrong.

> +       }
> +
> +       if (length < sizeof(*rp)) {
> +               btd_error(adapter->dev_id,
> +                         "Too small Set Device Flags complete event: %d",
> +                         length);
> +               return;
> +       }
> +
> +       ba2str(&rp->addr.bdaddr, addr);
> +
> +       dev = btd_adapter_find_device(adapter, &rp->addr.bdaddr, rp->addr.type);
> +       if (!dev) {
> +               btd_error(adapter->dev_id,
> +                       "Set Device Flags complete for unknown device %s", addr);
> +               return;
> +       }
> +
> +       if (status != MGMT_STATUS_SUCCESS) {
> +               btd_error(adapter->dev_id,
> +                       "Failed to configure wakeable %s (%u): %s (0x%02x)",
> +                       addr, rp->addr.type, mgmt_errstr(status), status);
> +               return;
> +       }
> +
> +       device_set_wake_allowed_complete(dev);
> +}
> +
> +void adapter_set_device_wakeable(struct btd_adapter *adapter,
> +                                struct btd_device *device, bool wakeable)
> +{
> +       struct mgmt_cp_set_device_flags cp;
> +       const bdaddr_t *bdaddr;
> +       uint8_t bdaddr_type;
> +
> +       if (!kernel_conn_control)
> +               return;
> +
> +       bdaddr = device_get_address(device);
> +       bdaddr_type = btd_device_get_bdaddr_type(device);
> +
> +       memset(&cp, 0, sizeof(cp));
> +       bacpy(&cp.addr.bdaddr, bdaddr);
> +       cp.addr.type = bdaddr_type;
> +       cp.current_flags = btd_device_get_current_flags(device);
> +       if (wakeable)
> +               cp.current_flags |= DEVICE_FLAG_REMOTE_WAKEUP;
> +       else
> +               cp.current_flags &= ~DEVICE_FLAG_REMOTE_WAKEUP;
> +
> +       mgmt_send(adapter->mgmt, MGMT_OP_SET_DEVICE_FLAGS, adapter->dev_id,
> +                 sizeof(cp), &cp, set_device_wakeable_complete, adapter, NULL);
> +}
> +
> +static void device_flags_changed_callback(uint16_t index, uint16_t length,
> +                                         const void *param, void *user_data)
> +{
> +       const struct mgmt_ev_device_flags_changed *ev = param;
> +       struct btd_adapter *adapter = user_data;
> +       struct btd_device *dev;
> +       char addr[18];
> +
> +       if (length < sizeof(*ev)) {
> +               btd_error(adapter->dev_id,
> +                         "Too small Device Flags Changed event: %d",
> +                         length);
> +               return;
> +       }
> +
> +       ba2str(&ev->addr.bdaddr, addr);
> +
> +       dev = btd_adapter_find_device(adapter, &ev->addr.bdaddr, ev->addr.type);
> +       if (!dev) {
> +               btd_error(adapter->dev_id,
> +                       "Device Flags Changed for unknown device %s", addr);
> +               return;
> +       }
> +
> +       btd_device_flags_changed(dev, ev->supported_flags, ev->current_flags);
> +}
> +
> +
>  static void remove_device_complete(uint8_t status, uint16_t length,
>                                         const void *param, void *user_data)
>  {
> @@ -8544,6 +8637,11 @@ static int adapter_register(struct btd_adapter *adapter)
>                                                         adapter, NULL);
>
>  load:
> +       mgmt_register(adapter->mgmt, MGMT_EV_DEVICE_FLAGS_CHANGED,
> +                                               adapter->dev_id,
> +                                               device_flags_changed_callback,
> +                                               adapter, NULL);
> +
>         load_config(adapter);
>         fix_storage(adapter);
>         load_drivers(adapter);
> diff --git a/src/adapter.h b/src/adapter.h
> index d0a5253bd..f8ac20261 100644
> --- a/src/adapter.h
> +++ b/src/adapter.h
> @@ -213,6 +213,8 @@ int adapter_connect_list_add(struct btd_adapter *adapter,
>                                         struct btd_device *device);
>  void adapter_connect_list_remove(struct btd_adapter *adapter,
>                                                 struct btd_device *device);
> +void adapter_set_device_wakeable(struct btd_adapter *adapter,
> +                                struct btd_device *dev, bool wakeable);
>  void adapter_auto_connect_add(struct btd_adapter *adapter,
>                                         struct btd_device *device);
>  void adapter_auto_connect_remove(struct btd_adapter *adapter,
> @@ -231,4 +233,3 @@ void btd_adapter_for_each_device(struct btd_adapter *adapter,
>                         void *data);
>
>  bool btd_le_connect_before_pairing(void);
> -
> diff --git a/src/device.c b/src/device.c
> index 7b0eb256e..cd25111b8 100644
> --- a/src/device.c
> +++ b/src/device.c
> @@ -177,6 +177,12 @@ struct csrk_info {
>         uint32_t counter;
>  };
>
> +typedef enum {
> +       WAKE_FLAG_DEFAULT = 0,
> +       WAKE_FLAG_ENABLED,
> +       WAKE_FLAG_DISABLED,
> +} wake_flag_t;
> +
>  struct btd_device {
>         int ref_count;
>
> @@ -189,6 +195,20 @@ struct btd_device {
>         bool            le;
>         bool            pending_paired;         /* "Paired" waiting for SDP */
>         bool            svc_refreshed;
> +
> +       /* Manage whether this device can wake the system from suspend.
> +        * - wake_support: Requires a profile that supports wake (i.e. HID)
> +        * - wake_allowed: Is wake currently allowed?
> +        * - pending_wake_allowed - Wake flag sent via set_device_flags
> +        * - wake_override - User configured wake setting
> +        */
> +       bool            wake_support;
> +       bool            wake_allowed;
> +       bool            pending_wake_allowed;
> +       wake_flag_t     wake_override;
> +
> +       uint32_t        supported_flags;
> +       uint32_t        current_flags;
>         GSList          *svc_callbacks;
>         GSList          *eir_uuids;
>         struct bt_ad    *ad;
> @@ -415,6 +435,12 @@ static gboolean store_device_info_cb(gpointer user_data)
>         g_key_file_set_boolean(key_file, "General", "Blocked",
>                                                         device->blocked);
>
> +       if (device->wake_override != WAKE_FLAG_DEFAULT) {
> +               g_key_file_set_boolean(key_file, "General", "WakeAllowed",
> +                                      device->wake_override ==
> +                                              WAKE_FLAG_ENABLED);
> +       }
> +
>         if (device->uuids) {
>                 GSList *l;
>                 int i;
> @@ -1318,6 +1344,105 @@ dev_property_advertising_data_exist(const GDBusPropertyTable *property,
>         return bt_ad_has_data(device->ad, NULL);
>  }
>
> +bool device_get_wake_support(struct btd_device *device)
> +{
> +       return device->wake_support;
> +}
> +
> +void device_set_wake_support(struct btd_device *device, bool wake_support)
> +{
> +       device->wake_support = wake_support;
> +
> +       /* If wake configuration has not been made yet, set the initial
> +        * configuration.
> +        */
> +       if (device->wake_override == WAKE_FLAG_DEFAULT) {
> +               device_set_wake_override(device, wake_support);
> +               device_set_wake_allowed(device, wake_support);
> +       }
> +}
> +
> +bool device_get_wake_allowed(struct btd_device *device)
> +{
> +       return device->wake_allowed;
> +}
> +
> +void device_set_wake_override(struct btd_device *device, bool wake_override)
> +{
> +       if (wake_override) {
> +               device->wake_override = WAKE_FLAG_ENABLED;
> +               device->current_flags |= DEVICE_FLAG_REMOTE_WAKEUP;
> +       } else {
> +               device->wake_override = WAKE_FLAG_DISABLED;
> +               device->current_flags &= ~DEVICE_FLAG_REMOTE_WAKEUP;
> +       }
> +}
> +
> +void device_set_wake_allowed(struct btd_device *device, bool wake_allowed)
> +{

I guess it would be a good idea to add a check if there is already a
device->pending_wake_allowed set, since there could be multiple
clients attempting to set it, also if device->wake_allowed is already
the same there is probably no reason to call
adapter_set_device_wakeable either.

> +       device->pending_wake_allowed = wake_allowed;
> +       adapter_set_device_wakeable(device_get_adapter(device), device,
> +                                   wake_allowed);
> +}
> +
> +void device_set_wake_allowed_complete(struct btd_device *device)
> +{
> +       device->wake_allowed = device->pending_wake_allowed;
> +       g_dbus_emit_property_changed(dbus_conn, device->path,
> +                                       DEVICE_INTERFACE, "WakeAllowed");
> +
> +       store_device_info(device);
> +}
> +
> +
> +static gboolean
> +dev_property_get_wake_allowed(const GDBusPropertyTable *property,
> +                            DBusMessageIter *iter, void *data)
> +{
> +       struct btd_device *device = data;
> +       dbus_bool_t wake_allowed = device_get_wake_allowed(device);
> +
> +       dbus_message_iter_append_basic(iter, DBUS_TYPE_BOOLEAN, &wake_allowed);
> +
> +       return TRUE;
> +}
> +
> +static void dev_property_set_wake_allowed(const GDBusPropertyTable *property,
> +                                        DBusMessageIter *value,
> +                                        GDBusPendingPropertySet id, void *data)
> +{
> +       struct btd_device *device = data;
> +       dbus_bool_t b;
> +
> +       if (dbus_message_iter_get_arg_type(value) != DBUS_TYPE_BOOLEAN) {
> +               g_dbus_pending_property_error(id,
> +                                       ERROR_INTERFACE ".InvalidArguments",
> +                                       "Invalid arguments in method call");
> +               return;
> +       }
> +
> +       if (device->temporary) {
> +               g_dbus_pending_property_error(id,
> +                                       ERROR_INTERFACE ".Unsupported",
> +                                       "Cannot set property while temporary");
> +               return;
> +       }
> +
> +       dbus_message_iter_get_basic(value, &b);
> +       device_set_wake_override(device, b);
> +       device_set_wake_allowed(device, b);

We should probably store the id here and only invoke
g_dbus_pendin_property* on complete that way the client is notified
even if the command fails.

> +       g_dbus_pending_property_success(id);
> +}
> +
> +static gboolean dev_property_wake_allowed_exist(
> +               const GDBusPropertyTable *property, void *data)
> +{
> +       struct btd_device *device = data;
> +
> +       return device_get_wake_support(device);
> +}
> +
> +
>  static gboolean disconnect_all(gpointer user_data)
>  {
>         struct btd_device *device = user_data;
> @@ -2790,6 +2915,9 @@ static const GDBusPropertyTable device_properties[] = {
>         { "AdvertisingData", "a{yv}", dev_property_get_advertising_data,
>                                 NULL, dev_property_advertising_data_exist,
>                                 G_DBUS_PROPERTY_FLAG_EXPERIMENTAL },
> +       { "WakeAllowed", "b", dev_property_get_wake_allowed,
> +                               dev_property_set_wake_allowed,
> +                               dev_property_wake_allowed_exist },
>         { }
>  };
>
> @@ -3038,9 +3166,11 @@ static void convert_info(struct btd_device *device, GKeyFile *key_file)
>  static void load_info(struct btd_device *device, const char *local,
>                         const char *peer, GKeyFile *key_file)
>  {
> +       GError *gerr = NULL;
>         char *str;
>         gboolean store_needed = FALSE;
>         gboolean blocked;
> +       gboolean wake_allowed;
>         char **uuids;
>         int source, vendor, product, version;
>         char **techno, **t;
> @@ -3152,6 +3282,17 @@ next:
>                 btd_device_set_pnpid(device, source, vendor, product, version);
>         }
>
> +       /* Wake allowed is only configured and stored if user changed it.
> +        * Otherwise, we enable if profile supports it. */
> +       wake_allowed = g_key_file_get_boolean(key_file, "General",
> +                                             "WakeAllowed", &gerr);
> +       if (!gerr) {
> +               device_set_wake_override(device, wake_allowed);
> +       } else {
> +               g_error_free(gerr);
> +               gerr = NULL;
> +       }
> +
>         if (store_needed)
>                 store_device_info(device);
>  }
> @@ -6558,6 +6699,49 @@ void btd_device_set_pnpid(struct btd_device *device, uint16_t source,
>         store_device_info(device);
>  }
>
> +uint32_t btd_device_get_current_flags(struct btd_device *dev) {
> +       return dev->current_flags;
> +}
> +
> +/* This event is sent immediately after add device on all mgmt sockets.
> + * Afterwards, it is only sent to mgmt sockets other than the one which called
> + * set_device_flags.
> + */
> +void btd_device_flags_changed(struct btd_device *dev, uint32_t supported_flags,
> +                             uint32_t current_flags)
> +{
> +       int i;
> +       const uint32_t changed_flags = dev->current_flags ^ current_flags;
> +       bool flag_value;
> +
> +       dev->supported_flags = supported_flags;
> +       dev->current_flags = current_flags;
> +
> +       if (!changed_flags)
> +               return;
> +
> +       if (changed_flags & DEVICE_FLAG_REMOTE_WAKEUP) {
> +               flag_value = !!(current_flags & DEVICE_FLAG_REMOTE_WAKEUP);
> +               dev->pending_wake_allowed = flag_value;
> +
> +               /* If an override exists and doesn't match the current state,
> +                * apply it. This logic will run after Add Device only and will
> +                * enable wake for previously paired devices.
> +                */
> +               if (dev->wake_override != WAKE_FLAG_DEFAULT) {
> +                       bool wake_allowed =
> +                               dev->wake_override == WAKE_FLAG_ENABLED;
> +                       if (flag_value != wake_allowed) {
> +                               device_set_wake_allowed(dev, wake_allowed);
> +                       } else {
> +                               device_set_wake_allowed_complete(dev);
> +                       }
> +               } else {
> +                       device_set_wake_allowed_complete(dev);
> +               }
> +       }
> +}
> +
>  static void service_state_changed(struct btd_service *service,
>                                                 btd_service_state_t old_state,
>                                                 btd_service_state_t new_state,
> diff --git a/src/device.h b/src/device.h
> index 06b100499..104e3f1dd 100644
> --- a/src/device.h
> +++ b/src/device.h
> @@ -33,6 +33,7 @@ struct btd_device *device_create_from_storage(struct btd_adapter *adapter,
>  char *btd_device_get_storage_path(struct btd_device *device,
>                                 const char *filename);
>
> +
>  void btd_device_device_set_name(struct btd_device *device, const char *name);
>  void device_store_cached_name(struct btd_device *dev, const char *name);
>  void device_get_name(struct btd_device *device, char *name, size_t len);
> @@ -139,6 +140,10 @@ void device_store_svc_chng_ccc(struct btd_device *device, uint8_t bdaddr_type,
>                                                                 uint16_t value);
>  void device_load_svc_chng_ccc(struct btd_device *device, uint16_t *ccc_le,
>                                                         uint16_t *ccc_bredr);
> +void device_set_wake_support(struct btd_device *device, bool wake_support);
> +void device_set_wake_override(struct btd_device *device, bool wake_override);
> +void device_set_wake_allowed(struct btd_device *device, bool wake_allowed);
> +void device_set_wake_allowed_complete(struct btd_device *device);
>
>  typedef void (*disconnect_watch) (struct btd_device *device, gboolean removal,
>                                         void *user_data);
> @@ -176,5 +181,9 @@ struct btd_service *btd_device_get_service(struct btd_device *dev,
>  int device_discover_services(struct btd_device *device);
>  int btd_device_connect_services(struct btd_device *dev, GSList *services);
>
> +uint32_t btd_device_get_current_flags(struct btd_device *dev);
> +void btd_device_flags_changed(struct btd_device *dev, uint32_t supported_flags,
> +                             uint32_t current_flags);
> +
>  void btd_device_init(void);
>  void btd_device_cleanup(void);
> --
> 2.27.0.111.gc72c7da667-goog
>


-- 
Luiz Augusto von Dentz