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//
// Copyright (C) 2011 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#include "update_engine/cros/omaha_response_handler_action.h"
#include <limits>
#include <string>
#include <base/logging.h>
#include <base/strings/string_number_conversions.h>
#include <base/version.h>
#include <policy/device_policy.h>
#include "update_engine/common/constants.h"
#include "update_engine/common/hardware_interface.h"
#include "update_engine/common/prefs_interface.h"
#include "update_engine/common/system_state.h"
#include "update_engine/common/utils.h"
#include "update_engine/cros/connection_manager_interface.h"
#include "update_engine/cros/omaha_request_params.h"
#include "update_engine/cros/payload_state_interface.h"
#include "update_engine/payload_consumer/delta_performer.h"
#include "update_engine/update_manager/policy.h"
#include "update_engine/update_manager/update_manager.h"
using chromeos_update_manager::kRollforwardInfinity;
using chromeos_update_manager::Policy;
using chromeos_update_manager::UpdateManager;
using std::numeric_limits;
using std::string;
namespace chromeos_update_engine {
OmahaResponseHandlerAction::OmahaResponseHandlerAction()
: deadline_file_(constants::kOmahaResponseDeadlineFile) {}
void OmahaResponseHandlerAction::PerformAction() {
CHECK(HasInputObject());
ScopedActionCompleter completer(processor_, this);
const OmahaResponse& response = GetInputObject();
if (!response.update_exists) {
LOG(INFO) << "There are no updates. Aborting.";
completer.set_code(ErrorCode::kNoUpdate);
return;
}
// All decisions as to which URL should be used have already been done. So,
// make the current URL as the download URL.
string current_url = SystemState::Get()->payload_state()->GetCurrentUrl();
if (current_url.empty()) {
// This shouldn't happen as we should always supply the HTTPS backup URL.
// Handling this anyway, just in case.
LOG(ERROR) << "There are no suitable URLs in the response to use.";
completer.set_code(ErrorCode::kOmahaResponseInvalid);
return;
}
// This is the url to the first package, not all packages.
// (For updates): All |Action|s prior to this must pass in non-excluded URLs
// within the |OmahaResponse|, reference exlusion logic in
// |OmahaRequestAction| and keep the enforcement of exclusions for updates.
install_plan_.download_url = current_url;
install_plan_.version = response.version;
OmahaRequestParams* const params = SystemState::Get()->request_params();
PayloadStateInterface* const payload_state =
SystemState::Get()->payload_state();
// If we're using p2p to download and there is a local peer, use it.
if (payload_state->GetUsingP2PForDownloading() &&
!payload_state->GetP2PUrl().empty()) {
LOG(INFO) << "Replacing URL " << install_plan_.download_url
<< " with local URL " << payload_state->GetP2PUrl()
<< " since p2p is enabled.";
install_plan_.download_url = payload_state->GetP2PUrl();
payload_state->SetUsingP2PForDownloading(true);
}
// Fill up the other properties based on the response.
string update_check_response_hash;
for (const auto& package : response.packages) {
brillo::Blob raw_hash;
if (!base::HexStringToBytes(package.hash, &raw_hash)) {
LOG(ERROR) << "Failed to convert payload hash from hex string to bytes: "
<< package.hash;
completer.set_code(ErrorCode::kOmahaResponseInvalid);
return;
}
install_plan_.payloads.push_back(
{.payload_urls = package.payload_urls,
.size = package.size,
.metadata_size = package.metadata_size,
.metadata_signature = package.metadata_signature,
.hash = raw_hash,
.type = package.is_delta ? InstallPayloadType::kDelta
: InstallPayloadType::kFull,
.fp = package.fp,
.app_id = package.app_id});
update_check_response_hash += package.hash + ":";
}
install_plan_.public_key_rsa = response.public_key_rsa;
install_plan_.hash_checks_mandatory = AreHashChecksMandatory(response);
install_plan_.is_resume = DeltaPerformer::CanResumeUpdate(
SystemState::Get()->prefs(), update_check_response_hash);
if (install_plan_.is_resume) {
payload_state->UpdateResumed();
} else {
payload_state->UpdateRestarted();
LOG_IF(WARNING,
!DeltaPerformer::ResetUpdateProgress(SystemState::Get()->prefs(),
false))
<< "Unable to reset the update progress.";
LOG_IF(WARNING,
!SystemState::Get()->prefs()->SetString(
kPrefsUpdateCheckResponseHash, update_check_response_hash))
<< "Unable to save the update check response hash.";
}
if (params->is_install()) {
install_plan_.target_slot =
SystemState::Get()->boot_control()->GetCurrentSlot();
install_plan_.source_slot = BootControlInterface::kInvalidSlot;
} else {
install_plan_.source_slot =
SystemState::Get()->boot_control()->GetCurrentSlot();
install_plan_.target_slot = install_plan_.source_slot == 0 ? 1 : 0;
}
// The Omaha response doesn't include the channel name for this image, so we
// use the download_channel we used during the request to tag the target slot.
// This will be used in the next boot to know the channel the image was
// downloaded from.
string current_channel_key =
kPrefsChannelOnSlotPrefix + std::to_string(install_plan_.target_slot);
SystemState::Get()->prefs()->SetString(current_channel_key,
params->download_channel());
// Checking whether device is able to boot up the returned rollback image.
if (response.is_rollback) {
if (!params->rollback_allowed()) {
LOG(ERROR) << "Received rollback image but rollback is not allowed.";
completer.set_code(ErrorCode::kOmahaResponseInvalid);
return;
}
// Calculate the values on the version values on current device.
auto min_kernel_key_version = static_cast<uint32_t>(
SystemState::Get()->hardware()->GetMinKernelKeyVersion());
auto min_firmware_key_version = static_cast<uint32_t>(
SystemState::Get()->hardware()->GetMinFirmwareKeyVersion());
uint32_t kernel_key_version =
static_cast<uint32_t>(response.rollback_key_version.kernel_key) << 16 |
static_cast<uint32_t>(response.rollback_key_version.kernel);
uint32_t firmware_key_version =
static_cast<uint32_t>(response.rollback_key_version.firmware_key)
<< 16 |
static_cast<uint32_t>(response.rollback_key_version.firmware);
LOG(INFO) << "Rollback image versions:"
<< " device_kernel_key_version=" << min_kernel_key_version
<< " image_kernel_key_version=" << kernel_key_version
<< " device_firmware_key_version=" << min_firmware_key_version
<< " image_firmware_key_version=" << firmware_key_version;
// Don't attempt a rollback if the versions are incompatible or the
// target image does not specify the version information.
if (kernel_key_version == numeric_limits<uint32_t>::max() ||
firmware_key_version == numeric_limits<uint32_t>::max() ||
kernel_key_version < min_kernel_key_version ||
firmware_key_version < min_firmware_key_version) {
LOG(ERROR) << "Device won't be able to boot up the rollback image.";
completer.set_code(ErrorCode::kRollbackNotPossible);
return;
}
install_plan_.is_rollback = true;
install_plan_.rollback_data_save_requested =
params->rollback_data_save_requested();
}
// Powerwash if either the response requires it or the parameters indicated
// powerwash (usually because there was a channel downgrade) and we are
// downgrading the version. Enterprise rollback, indicated by
// |response.is_rollback| is dealt with separately above.
if (response.powerwash_required) {
install_plan_.powerwash_required = true;
} else if (params->ShouldPowerwash() && !response.is_rollback) {
base::Version new_version(response.version);
base::Version current_version(params->app_version());
if (!new_version.IsValid()) {
LOG(WARNING) << "Not powerwashing,"
<< " the update's version number is unreadable."
<< " Update's version number: " << response.version;
} else if (!current_version.IsValid()) {
LOG(WARNING) << "Not powerwashing,"
<< " the current version number is unreadable."
<< " Current version number: " << params->app_version();
} else if (new_version < current_version) {
install_plan_.powerwash_required = true;
// Always try to preserve enrollment and wifi data for enrolled devices.
install_plan_.rollback_data_save_requested =
SystemState::Get()->device_policy() &&
SystemState::Get()->device_policy()->IsEnterpriseEnrolled();
}
}
TEST_AND_RETURN(HasOutputPipe());
if (HasOutputPipe())
SetOutputObject(install_plan_);
install_plan_.Dump();
// Send the deadline data (if any) to Chrome through a file. This is a pretty
// hacky solution but should be OK for now.
//
// TODO(petkov): Re-architect this to avoid communication through a
// file. Ideally, we would include this information in D-Bus's GetStatus
// method and UpdateStatus signal. A potential issue is that update_engine may
// be unresponsive during an update download.
if (!deadline_file_.empty()) {
if (payload_state->GetRollbackHappened()) {
// Don't do forced update if rollback has happened since the last update
// check where policy was present.
LOG(INFO) << "Not forcing update because a rollback happened.";
utils::WriteFile(deadline_file_.c_str(), nullptr, 0);
} else {
utils::WriteFile(deadline_file_.c_str(),
response.deadline.data(),
response.deadline.size());
}
chmod(deadline_file_.c_str(), S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
}
// Check the generated install-plan with the Policy to confirm that
// it can be applied at this time (or at all).
UpdateManager* const update_manager = SystemState::Get()->update_manager();
CHECK(update_manager);
auto ec = ErrorCode::kSuccess;
update_manager->PolicyRequest(
&Policy::UpdateCanBeApplied, &ec, &install_plan_);
completer.set_code(ec);
const auto allowed_milestones = params->rollback_allowed_milestones();
if (allowed_milestones > 0) {
auto max_firmware_rollforward = numeric_limits<uint32_t>::max();
auto max_kernel_rollforward = numeric_limits<uint32_t>::max();
// Determine the version to update the max rollforward verified boot
// value.
OmahaResponse::RollbackKeyVersion version =
response.past_rollback_key_version;
// Determine the max rollforward values to be set in the TPM.
max_firmware_rollforward = static_cast<uint32_t>(version.firmware_key)
<< 16 |
static_cast<uint32_t>(version.firmware);
max_kernel_rollforward = static_cast<uint32_t>(version.kernel_key) << 16 |
static_cast<uint32_t>(version.kernel);
// In the case that the value is 0xffffffff, log a warning because the
// device should not be installing a rollback image without having version
// information.
if (max_firmware_rollforward == numeric_limits<uint32_t>::max() ||
max_kernel_rollforward == numeric_limits<uint32_t>::max()) {
LOG(WARNING)
<< "Max rollforward values were not sent in rollback response: "
<< " max_kernel_rollforward=" << max_kernel_rollforward
<< " max_firmware_rollforward=" << max_firmware_rollforward
<< " rollback_allowed_milestones="
<< params->rollback_allowed_milestones();
} else {
LOG(INFO) << "Setting the max rollforward values: "
<< " max_kernel_rollforward=" << max_kernel_rollforward
<< " max_firmware_rollforward=" << max_firmware_rollforward
<< " rollback_allowed_milestones="
<< params->rollback_allowed_milestones();
SystemState::Get()->hardware()->SetMaxKernelKeyRollforward(
max_kernel_rollforward);
// TODO(crbug/783998): Set max firmware rollforward when implemented.
}
} else {
LOG(INFO) << "Rollback is not allowed. Setting max rollforward values"
<< " to infinity";
// When rollback is not allowed, explicitly set the max roll forward to
// infinity.
SystemState::Get()->hardware()->SetMaxKernelKeyRollforward(
kRollforwardInfinity);
// TODO(crbug/783998): Set max firmware rollforward when implemented.
}
}
bool OmahaResponseHandlerAction::AreHashChecksMandatory(
const OmahaResponse& response) {
// We sometimes need to waive the hash checks in order to download from
// sources that don't provide hashes, such as dev server.
// At this point UpdateAttempter::IsAnyUpdateSourceAllowed() has already been
// checked, so an unofficial update URL won't get this far unless it's OK to
// use without a hash. Additionally, we want to always waive hash checks on
// unofficial builds (i.e. dev/test images).
// The end result is this:
// * Base image:
// - Official URLs require a hash.
// - Unofficial URLs only get this far if the IsAnyUpdateSourceAllowed()
// devmode/debugd checks pass, in which case the hash is waived.
// * Dev/test image:
// - Any URL is allowed through with no hash checking.
if (!SystemState::Get()->request_params()->IsUpdateUrlOfficial() ||
!SystemState::Get()->hardware()->IsOfficialBuild()) {
// Still do a hash check if a public key is included.
if (!response.public_key_rsa.empty()) {
// The autoupdate_CatchBadSignatures test checks for this string
// in log-files. Keep in sync.
LOG(INFO) << "Mandating payload hash checks since Omaha Response "
<< "for unofficial build includes public RSA key.";
return true;
} else {
LOG(INFO) << "Waiving payload hash checks for unofficial update URL.";
return false;
}
}
LOG(INFO) << "Mandating hash checks for official URL on official build.";
return true;
}
} // namespace chromeos_update_engine