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author | zhang sanshan <sanshan.zhang@nxp.com> | 2017-05-15 10:45:07 +0800 |
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committer | Chen Guoyin <guoyin.chen@nxp.com> | 2017-07-10 15:08:53 +0800 |
commit | 1c79796a523255af5d012fa3cbc5400131b3b8b9 (patch) | |
tree | 671d094845bc787fca67f158f73084db3ee80f49 /lib/avb/libavb_ab/avb_ab_flow.c | |
parent | 893ec7807779aa34ce49866f03e49c592fff9543 (diff) | |
download | u-boot-imx-1c79796a523255af5d012fa3cbc5400131b3b8b9.zip u-boot-imx-1c79796a523255af5d012fa3cbc5400131b3b8b9.tar.gz u-boot-imx-1c79796a523255af5d012fa3cbc5400131b3b8b9.tar.bz2 |
MA-9409-1 enable avb on android things.
Fix issue for API changed from v2017.
porting below patch from v2016.
commit 44834fd12f60a090e3d10ab6f84a75460894d49d
Change-Id: Ifaf0b86dd29648f9150646f00f54502676df9013
Signed-off-by: zhang sanshan <sanshan.zhang@nxp.com>
Diffstat (limited to 'lib/avb/libavb_ab/avb_ab_flow.c')
-rw-r--r-- | lib/avb/libavb_ab/avb_ab_flow.c | 516 |
1 files changed, 516 insertions, 0 deletions
diff --git a/lib/avb/libavb_ab/avb_ab_flow.c b/lib/avb/libavb_ab/avb_ab_flow.c new file mode 100644 index 0000000..3adb927 --- /dev/null +++ b/lib/avb/libavb_ab/avb_ab_flow.c @@ -0,0 +1,516 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "avb_ab_flow.h" + +bool avb_ab_data_verify_and_byteswap(const AvbABData* src, AvbABData* dest) { + /* Ensure magic is correct. */ + if (avb_safe_memcmp(src->magic, AVB_AB_MAGIC, AVB_AB_MAGIC_LEN) != 0) { + avb_error("Magic is incorrect.\n"); + return false; + } + + avb_memcpy(dest, src, sizeof(AvbABData)); + dest->crc32 = avb_be32toh(dest->crc32); + + /* Ensure we don't attempt to access any fields if the major version + * is not supported. + */ + if (dest->version_major > AVB_AB_MAJOR_VERSION) { + avb_error("No support for given major version.\n"); + return false; + } + + /* Bail if CRC32 doesn't match. */ + if (dest->crc32 != + avb_crc32((const uint8_t*)dest, sizeof(AvbABData) - sizeof(uint32_t))) { + avb_error("CRC32 does not match.\n"); + return false; + } + + return true; +} + +void avb_ab_data_update_crc_and_byteswap(const AvbABData* src, + AvbABData* dest) { + avb_memcpy(dest, src, sizeof(AvbABData)); + dest->crc32 = avb_htobe32( + avb_crc32((const uint8_t*)dest, sizeof(AvbABData) - sizeof(uint32_t))); +} + +void avb_ab_data_init(AvbABData* data) { + avb_memset(data, '\0', sizeof(AvbABData)); + avb_memcpy(data->magic, AVB_AB_MAGIC, AVB_AB_MAGIC_LEN); + data->version_major = AVB_AB_MAJOR_VERSION; + data->version_minor = AVB_AB_MINOR_VERSION; + data->slots[0].priority = AVB_AB_MAX_PRIORITY; + data->slots[0].tries_remaining = AVB_AB_MAX_TRIES_REMAINING; + data->slots[0].successful_boot = 0; + data->slots[1].priority = AVB_AB_MAX_PRIORITY - 1; + data->slots[1].tries_remaining = AVB_AB_MAX_TRIES_REMAINING; + data->slots[1].successful_boot = 0; +} + +/* The AvbABData struct is stored 2048 bytes into the 'misc' partition + * following the 'struct bootloader_message' field. The struct is + * compatible with the guidelines in bootable/recovery/bootloader.h - + * e.g. it is stored in the |slot_suffix| field, starts with a + * NUL-byte, and is 32 bytes long. + */ +#define AB_METADATA_MISC_PARTITION_OFFSET 2048 + +AvbIOResult avb_ab_data_read(AvbABOps* ab_ops, AvbABData* data) { + AvbOps* ops = ab_ops->ops; + AvbABData serialized; + AvbIOResult io_ret; + size_t num_bytes_read; + + io_ret = ops->read_from_partition(ops, + "misc", + AB_METADATA_MISC_PARTITION_OFFSET, + sizeof(AvbABData), + &serialized, + &num_bytes_read); + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + return AVB_IO_RESULT_ERROR_OOM; + } else if (io_ret != AVB_IO_RESULT_OK || + num_bytes_read != sizeof(AvbABData)) { + avb_error("Error reading A/B metadata.\n"); + return AVB_IO_RESULT_ERROR_IO; + } + + if (!avb_ab_data_verify_and_byteswap(&serialized, data)) { + avb_error( + "Error validating A/B metadata from disk. " + "Resetting and writing new A/B metadata to disk.\n"); + avb_ab_data_init(data); + return avb_ab_data_write(ab_ops, data); + } + + return AVB_IO_RESULT_OK; +} + +AvbIOResult avb_ab_data_write(AvbABOps* ab_ops, const AvbABData* data) { + AvbOps* ops = ab_ops->ops; + AvbABData serialized; + AvbIOResult io_ret; + + avb_ab_data_update_crc_and_byteswap(data, &serialized); + io_ret = ops->write_to_partition(ops, + "misc", + AB_METADATA_MISC_PARTITION_OFFSET, + sizeof(AvbABData), + &serialized); + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + return AVB_IO_RESULT_ERROR_OOM; + } else if (io_ret != AVB_IO_RESULT_OK) { + avb_error("Error writing A/B metadata.\n"); + return AVB_IO_RESULT_ERROR_IO; + } + return AVB_IO_RESULT_OK; +} + +static bool slot_is_bootable(AvbABSlotData* slot) { + return slot->priority > 0 && + (slot->successful_boot || (slot->tries_remaining > 0)); +} + +static void slot_set_unbootable(AvbABSlotData* slot) { + slot->priority = 0; + slot->tries_remaining = 0; + slot->successful_boot = 0; +} + +/* Ensure all unbootable and/or illegal states are marked as the + * canonical 'unbootable' state, e.g. priority=0, tries_remaining=0, + * and successful_boot=0. + */ +static void slot_normalize(AvbABSlotData* slot) { + if (slot->priority > 0) { + if (slot->tries_remaining == 0 && !slot->successful_boot) { + /* We've exhausted all tries -> unbootable. */ + slot_set_unbootable(slot); + } + if (slot->tries_remaining > 0 && slot->successful_boot) { + /* Illegal state - avb_ab_mark_slot_successful() will clear + * tries_remaining when setting successful_boot. + */ + slot_set_unbootable(slot); + } + } else { + slot_set_unbootable(slot); + } +} + +static const char* slot_suffixes[2] = {"_a", "_b"}; + +/* Helper function to load metadata - returns AVB_IO_RESULT_OK on + * success, error code otherwise. + */ +static AvbIOResult load_metadata(AvbABOps* ab_ops, + AvbABData* ab_data, + AvbABData* ab_data_orig) { + AvbIOResult io_ret; + + io_ret = ab_ops->read_ab_metadata(ab_ops, ab_data); + if (io_ret != AVB_IO_RESULT_OK) { + avb_error("I/O error while loading A/B metadata.\n"); + return io_ret; + } + *ab_data_orig = *ab_data; + + /* Ensure data is normalized, e.g. illegal states will be marked as + * unbootable and all unbootable states are represented with + * (priority=0, tries_remaining=0, successful_boot=0). + */ + slot_normalize(&ab_data->slots[0]); + slot_normalize(&ab_data->slots[1]); + return AVB_IO_RESULT_OK; +} + +/* Writes A/B metadata to disk only if it has changed - returns + * AVB_IO_RESULT_OK on success, error code otherwise. + */ +static AvbIOResult save_metadata_if_changed(AvbABOps* ab_ops, + AvbABData* ab_data, + AvbABData* ab_data_orig) { + if (avb_safe_memcmp(ab_data, ab_data_orig, sizeof(AvbABData)) != 0) { + avb_debug("Writing A/B metadata to disk.\n"); + return ab_ops->write_ab_metadata(ab_ops, ab_data); + } + return AVB_IO_RESULT_OK; +} + +AvbABFlowResult avb_ab_flow(AvbABOps* ab_ops, + const char* const* requested_partitions, + bool allow_verification_error, + AvbSlotVerifyData** out_data) { + AvbOps* ops = ab_ops->ops; + AvbSlotVerifyData* slot_data[2] = {NULL, NULL}; + AvbSlotVerifyData* data = NULL; + AvbABFlowResult ret; + AvbABData ab_data, ab_data_orig; + size_t slot_index_to_boot, n; + AvbIOResult io_ret; + bool saw_and_allowed_verification_error = false; + + io_ret = load_metadata(ab_ops, &ab_data, &ab_data_orig); + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + ret = AVB_AB_FLOW_RESULT_ERROR_OOM; + goto out; + } else if (io_ret != AVB_IO_RESULT_OK) { + ret = AVB_AB_FLOW_RESULT_ERROR_IO; + goto out; + } + + /* Validate all bootable slots. */ + for (n = 0; n < 2; n++) { + if (slot_is_bootable(&ab_data.slots[n])) { + AvbSlotVerifyResult verify_result; + bool set_slot_unbootable = false; + + verify_result = avb_slot_verify(ops, + requested_partitions, + slot_suffixes[n], + allow_verification_error, + &slot_data[n]); + switch (verify_result) { + case AVB_SLOT_VERIFY_RESULT_ERROR_OOM: + ret = AVB_AB_FLOW_RESULT_ERROR_OOM; + goto out; + + case AVB_SLOT_VERIFY_RESULT_ERROR_IO: + ret = AVB_AB_FLOW_RESULT_ERROR_IO; + goto out; + + case AVB_SLOT_VERIFY_RESULT_OK: + break; + + case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA: + case AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION: + /* Even with |allow_verification_error| these mean game over. */ + set_slot_unbootable = true; + break; + + /* explicit fallthrough. */ + case AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION: + case AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX: + case AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED: + if (allow_verification_error) { + /* Do nothing since we allow this. */ + avb_debugv("Allowing slot ", + slot_suffixes[n], + " which verified " + "with result ", + avb_slot_verify_result_to_string(verify_result), + " because |allow_verification_error| is true.\n", + NULL); + saw_and_allowed_verification_error = true; + } else { + set_slot_unbootable = true; + } + break; + } + + if (set_slot_unbootable) { + avb_errorv("Error verifying slot ", + slot_suffixes[n], + " with result ", + avb_slot_verify_result_to_string(verify_result), + " - setting unbootable.\n", + NULL); + slot_set_unbootable(&ab_data.slots[n]); + } + } + } + + if (slot_is_bootable(&ab_data.slots[0]) && + slot_is_bootable(&ab_data.slots[1])) { + if (ab_data.slots[1].priority > ab_data.slots[0].priority) { + slot_index_to_boot = 1; + } else { + slot_index_to_boot = 0; + } + } else if (slot_is_bootable(&ab_data.slots[0])) { + slot_index_to_boot = 0; + } else if (slot_is_bootable(&ab_data.slots[1])) { + slot_index_to_boot = 1; + } else { + /* No bootable slots! */ + avb_error("No bootable slots found.\n"); + ret = AVB_AB_FLOW_RESULT_ERROR_NO_BOOTABLE_SLOTS; + goto out; + } + + /* Update stored rollback index such that the stored rollback index + * is the largest value supporting all currently bootable slots. Do + * this for every rollback index location. + */ + for (n = 0; n < AVB_MAX_NUMBER_OF_ROLLBACK_INDEX_LOCATIONS; n++) { + uint64_t rollback_index_value = 0; + + if (slot_data[0] != NULL && slot_data[1] != NULL) { + uint64_t a_rollback_index = slot_data[0]->rollback_indexes[n]; + uint64_t b_rollback_index = slot_data[1]->rollback_indexes[n]; + rollback_index_value = + (a_rollback_index < b_rollback_index ? a_rollback_index + : b_rollback_index); + } else if (slot_data[0] != NULL) { + rollback_index_value = slot_data[0]->rollback_indexes[n]; + } else if (slot_data[1] != NULL) { + rollback_index_value = slot_data[1]->rollback_indexes[n]; + } + + if (rollback_index_value != 0) { + uint64_t current_rollback_index_value; + io_ret = ops->read_rollback_index(ops, n, ¤t_rollback_index_value); + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + ret = AVB_AB_FLOW_RESULT_ERROR_OOM; + goto out; + } else if (io_ret != AVB_IO_RESULT_OK) { + avb_error("Error getting rollback index for slot.\n"); + ret = AVB_AB_FLOW_RESULT_ERROR_IO; + goto out; + } + if (current_rollback_index_value != rollback_index_value) { + io_ret = ops->write_rollback_index(ops, n, rollback_index_value); + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + ret = AVB_AB_FLOW_RESULT_ERROR_OOM; + goto out; + } else if (io_ret != AVB_IO_RESULT_OK) { + avb_error("Error setting stored rollback index.\n"); + ret = AVB_AB_FLOW_RESULT_ERROR_IO; + goto out; + } + } + } + } + + /* Finally, select this slot. */ + avb_assert(slot_data[slot_index_to_boot] != NULL); + data = slot_data[slot_index_to_boot]; + slot_data[slot_index_to_boot] = NULL; + if (saw_and_allowed_verification_error) { + avb_assert(allow_verification_error); + ret = AVB_AB_FLOW_RESULT_OK_WITH_VERIFICATION_ERROR; + } else { + ret = AVB_AB_FLOW_RESULT_OK; + } + + /* ... and decrement tries remaining, if applicable. */ + if (!ab_data.slots[slot_index_to_boot].successful_boot && + ab_data.slots[slot_index_to_boot].tries_remaining > 0) { + ab_data.slots[slot_index_to_boot].tries_remaining -= 1; + } + +out: + io_ret = save_metadata_if_changed(ab_ops, &ab_data, &ab_data_orig); + if (io_ret != AVB_IO_RESULT_OK) { + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + ret = AVB_AB_FLOW_RESULT_ERROR_OOM; + } else { + ret = AVB_AB_FLOW_RESULT_ERROR_IO; + } + if (data != NULL) { + avb_slot_verify_data_free(data); + data = NULL; + } + } + + for (n = 0; n < 2; n++) { + if (slot_data[n] != NULL) { + avb_slot_verify_data_free(slot_data[n]); + } + } + + if (out_data != NULL) { + *out_data = data; + } else { + if (data != NULL) { + avb_slot_verify_data_free(data); + } + } + + return ret; +} + +AvbIOResult avb_ab_mark_slot_active(AvbABOps* ab_ops, + unsigned int slot_number) { + AvbABData ab_data, ab_data_orig; + unsigned int other_slot_number; + AvbIOResult ret; + + avb_assert(slot_number < 2); + + ret = load_metadata(ab_ops, &ab_data, &ab_data_orig); + if (ret != AVB_IO_RESULT_OK) { + goto out; + } + + /* Make requested slot top priority, unsuccessful, and with max tries. */ + ab_data.slots[slot_number].priority = AVB_AB_MAX_PRIORITY; + ab_data.slots[slot_number].tries_remaining = AVB_AB_MAX_TRIES_REMAINING; + ab_data.slots[slot_number].successful_boot = 0; + + /* Ensure other slot doesn't have as high a priority. */ + other_slot_number = 1 - slot_number; + if (ab_data.slots[other_slot_number].priority == AVB_AB_MAX_PRIORITY) { + ab_data.slots[other_slot_number].priority = AVB_AB_MAX_PRIORITY - 1; + } + + ret = AVB_IO_RESULT_OK; + +out: + if (ret == AVB_IO_RESULT_OK) { + ret = save_metadata_if_changed(ab_ops, &ab_data, &ab_data_orig); + } + return ret; +} + +AvbIOResult avb_ab_mark_slot_unbootable(AvbABOps* ab_ops, + unsigned int slot_number) { + AvbABData ab_data, ab_data_orig; + AvbIOResult ret; + + avb_assert(slot_number < 2); + + ret = load_metadata(ab_ops, &ab_data, &ab_data_orig); + if (ret != AVB_IO_RESULT_OK) { + goto out; + } + + slot_set_unbootable(&ab_data.slots[slot_number]); + + ret = AVB_IO_RESULT_OK; + +out: + if (ret == AVB_IO_RESULT_OK) { + ret = save_metadata_if_changed(ab_ops, &ab_data, &ab_data_orig); + } + return ret; +} + +AvbIOResult avb_ab_mark_slot_successful(AvbABOps* ab_ops, + unsigned int slot_number) { + AvbABData ab_data, ab_data_orig; + AvbIOResult ret; + + avb_assert(slot_number < 2); + + ret = load_metadata(ab_ops, &ab_data, &ab_data_orig); + if (ret != AVB_IO_RESULT_OK) { + goto out; + } + + if (!slot_is_bootable(&ab_data.slots[slot_number])) { + avb_error("Cannot mark unbootable slot as successful.\n"); + ret = AVB_IO_RESULT_OK; + goto out; + } + + ab_data.slots[slot_number].tries_remaining = 0; + ab_data.slots[slot_number].successful_boot = 1; + + ret = AVB_IO_RESULT_OK; + +out: + if (ret == AVB_IO_RESULT_OK) { + ret = save_metadata_if_changed(ab_ops, &ab_data, &ab_data_orig); + } + return ret; +} + +const char* avb_ab_flow_result_to_string(AvbABFlowResult result) { + const char* ret = NULL; + + switch (result) { + case AVB_AB_FLOW_RESULT_OK: + ret = "OK"; + break; + + case AVB_AB_FLOW_RESULT_OK_WITH_VERIFICATION_ERROR: + ret = "OK_WITH_VERIFICATION_ERROR"; + break; + + case AVB_AB_FLOW_RESULT_ERROR_OOM: + ret = "ERROR_OOM"; + break; + + case AVB_AB_FLOW_RESULT_ERROR_IO: + ret = "ERROR_IO"; + break; + + case AVB_AB_FLOW_RESULT_ERROR_NO_BOOTABLE_SLOTS: + ret = "ERROR_NO_BOOTABLE_SLOTS"; + break; + /* Do not add a 'default:' case here because of -Wswitch. */ + } + + if (ret == NULL) { + avb_error("Unknown AvbABFlowResult value.\n"); + ret = "(unknown)"; + } + + return ret; +} |