system_update_configurator/
bridge.rs

1// Copyright 2022 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5//! Interface and impls to read/write the persistent storage for an [`OptOutPreference`].
6
7use async_trait::async_trait;
8use thiserror::Error;
9
10#[cfg(test)]
11pub mod testing;
12
13mod vx_ta;
14
15/// A user's preference for which updates to automatically fetch and apply.
16#[derive(Debug, Clone, Copy, PartialEq, Eq)]
17pub enum OptOutPreference {
18    /// Allow all published updates to be automatically fetched and applied.
19    AllowAllUpdates = 0,
20
21    /// Allow only critical security updates to be automatically fetched and applied.
22    AllowOnlySecurityUpdates,
23}
24
25/// An error encountered while accessing the underlying storage for the opt-out setting.
26#[derive(Debug, Error)]
27#[allow(missing_docs)]
28pub enum BridgeError {
29    #[error("TEE Internal Error")]
30    Internal(#[from] vx_ta::TeeError),
31    #[error("TEE Busy")]
32    Busy,
33}
34
35/// Interface to read/write the persistent storage for an [`OptOutPreference`].
36#[async_trait(?Send)]
37pub trait Bridge {
38    /// Reads the current persisted opt-out preference.
39    ///
40    /// Defaults to [`OptOutPreference::AllowAllUpdates`] if no preference is set.
41    async fn get_opt_out(&self) -> Result<OptOutPreference, BridgeError>;
42
43    /// Sets the persisted opt-out preference to `value`, or returns the error encountered while
44    /// attempting to do so.
45    async fn set_opt_out(&mut self, value: OptOutPreference) -> Result<(), BridgeError>;
46}
47
48/// Implementation of [`Bridge`] that interacts with secure storage on a device.
49#[derive(Debug)]
50pub struct OptOutStorage;
51
52#[async_trait(?Send)]
53impl Bridge for OptOutStorage {
54    async fn get_opt_out(&self) -> Result<OptOutPreference, BridgeError> {
55        let default_value = OptOutPreference::AllowAllUpdates;
56        let value = match vx_ta::ota_config_get(default_value as u32).map_err(map_tee_error)? {
57            0 => OptOutPreference::AllowAllUpdates,
58            _ => OptOutPreference::AllowOnlySecurityUpdates,
59        };
60        Ok(value)
61    }
62
63    async fn set_opt_out(&mut self, value: OptOutPreference) -> Result<(), BridgeError> {
64        vx_ta::ota_config_set(value as u32).map_err(map_tee_error)?;
65        Ok(())
66    }
67}
68
69fn map_tee_error(err: vx_ta::TeeError) -> BridgeError {
70    match err {
71        vx_ta::TeeError::Busy => BridgeError::Busy,
72        vx_ta::TeeError::General(_) => BridgeError::Internal(err),
73    }
74}
system_update_configurator/bridge.rs

system_update_configurator/
bridge.rs
