Add update_verifier for A/B OTA update. am: 1171d3a1

    $(LOCAL_PATH)/edify/Android.mk \

    $(LOCAL_PATH)/uncrypt/Android.mk \

    $(LOCAL_PATH)/updater/Android.mk \

    $(LOCAL_PATH)/update_verifier/Android.mk \

    $(LOCAL_PATH)/applypatch/Android.mk

# Copyright (C) 2015 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.

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

LOCAL_CLANG := true

LOCAL_SRC_FILES := update_verifier.cpp

LOCAL_MODULE := update_verifier

LOCAL_SHARED_LIBRARIES := libcutils libhardware

include $(BUILD_EXECUTABLE)

/*

 * Copyright (C) 2015 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.

 */

/*

 * This program verifies the integrity of the partitions after an A/B OTA

 * update. It gets invoked by init, and will only perform the verification if

 * it's the first boot post an A/B OTA update.

 *

 * It relies on dm-verity to capture any corruption on the partitions being

 * verified. dm-verity must be in enforcing mode, so that it will reboot the

 * device on dm-verity failures. When that happens, the bootloader should

 * mark the slot as unbootable and stops trying. We should never see a device

 * started in dm-verity logging mode but with isSlotBootable equals to 0.

 *

 * The current slot will be marked as having booted successfully if the

 * verifier reaches the end after the verification.

 *

 * TODO: The actual verification part will be added later after we have the

 * A/B OTA package format in place.

 */

#include <cutils/klog.h>

#include <string.h>

#include <hardware/boot_control.h>

#define LOG_TAG       "update_verifier"

#define INFO(x...)    KLOG_INFO(LOG_TAG, x)

#define ERROR(x...)   KLOG_ERROR(LOG_TAG, x)

int main(int argc, char** argv) {

  klog_init();

  klog_set_level(6);

  for (int i = 1; i < argc; i++) {

    INFO("Started with arg %d: %s\n", i, argv[i]);

  }

  const hw_module_t* hw_module;

  if (hw_get_module("bootctrl", &hw_module) != 0) {

    ERROR("Error getting bootctrl module.\n");

    return -1;

  }

  boot_control_module_t* module = reinterpret_cast<boot_control_module_t*>(

      const_cast<hw_module_t*>(hw_module));

  module->init(module);

  unsigned current_slot = module->getCurrentSlot(module);

  int bootable = module->isSlotBootable(module, current_slot);

  INFO("Booting slot %u: isSlotBootable=%d\n", current_slot, bootable);

  if (bootable == 0) {

    // The current slot has not booted successfully.

    // TODO: Add the actual verification after we have the A/B OTA package

    // format in place.

    // TODO: Assert the dm-verity mode. Bootloader should never boot a newly

    // flashed slot (isSlotBootable == 0) with dm-verity logging mode.

    int ret = module->markBootSuccessful(module);

    if (ret != 0) {

      ERROR("Error marking booted successfully: %s\n", strerror(-ret));

      return -1;

    }

    INFO("Marked slot %u as booted successfully.\n", current_slot);

  }

  INFO("Leaving update_verifier.\n");

  return 0;

}