diff options
Diffstat (limited to 'lib/libavb/avb_slot_verify.h')
| -rw-r--r-- | lib/libavb/avb_slot_verify.h | 59 |
1 files changed, 50 insertions, 9 deletions
diff --git a/lib/libavb/avb_slot_verify.h b/lib/libavb/avb_slot_verify.h index 73fd70d..8d0fa53 100644 --- a/lib/libavb/avb_slot_verify.h +++ b/lib/libavb/avb_slot_verify.h @@ -51,12 +51,25 @@ typedef enum { * be used ONLY for diagnostics and debugging. It cannot be used * unless AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR is also * used. + * + * AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO means that either + * AVB_HASHTREE_ERROR_MODE_RESTART or AVB_HASHTREE_ERROR_MODE_EIO is used + * depending on state. This mode implements a state machine whereby + * AVB_HASHTREE_ERROR_MODE_RESTART is used by default and when + * AVB_SLOT_VERIFY_FLAGS_RESTART_CAUSED_BY_HASHTREE_CORRUPTION is passed the + * mode transitions to AVB_HASHTREE_ERROR_MODE_EIO. When a new OS has been + * detected the device transitions back to the AVB_HASHTREE_ERROR_MODE_RESTART + * mode. To do this persistent storage is needed - specifically this means that + * the passed in AvbOps will need to have the read_persistent_value() and + * write_persistent_value() operations implemented. The name of the persistent + * value used is "avb.managed_verity_mode" and 32 bytes of storage is needed. */ typedef enum { AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE, AVB_HASHTREE_ERROR_MODE_RESTART, AVB_HASHTREE_ERROR_MODE_EIO, - AVB_HASHTREE_ERROR_MODE_LOGGING + AVB_HASHTREE_ERROR_MODE_LOGGING, + AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO } AvbHashtreeErrorMode; /* Flags that influence how avb_slot_verify() works. @@ -80,10 +93,26 @@ typedef enum { * contents loaded from |requested_partition| will be the contents of * the entire partition instead of just the size specified in the hash * descriptor. + * + * The AVB_SLOT_VERIFY_FLAGS_RESTART_CAUSED_BY_HASHTREE_CORRUPTION flag + * should be set if using AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO + * and the reason the boot loader is running is because the device + * was restarted by the dm-verity driver. + * + * If the AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION flag is set then + * data won't be loaded from the "vbmeta" partition and the + * |validate_vbmeta_public_key| operation is never called. Instead, the + * vbmeta structs in |requested_partitions| are loaded and processed and the + * |validate_public_key_for_partition| operation is called for each of these + * vbmeta structs. This flag is useful when booting into recovery on a device + * not using A/B - see section "Booting into recovery" in README.md for + * more information. */ typedef enum { AVB_SLOT_VERIFY_FLAGS_NONE = 0, - AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR = (1 << 0) + AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR = (1 << 0), + AVB_SLOT_VERIFY_FLAGS_RESTART_CAUSED_BY_HASHTREE_CORRUPTION = (1 << 1), + AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION = (1 << 2), } AvbSlotVerifyFlags; /* Get a textual representation of |result|. */ @@ -188,6 +217,10 @@ typedef struct { * set to AVB_HASHTREE_ERROR_MODE_EIO, and 'logging' if it's set to * AVB_HASHTREE_ERROR_MODE_LOGGING. * + * androidboot.veritymode.managed: This is set to 'yes' only + * if hashtree validation isn't disabled and the passed-in hashtree + * error mode is AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO. + * * androidboot.vbmeta.invalidate_on_error: This is set to 'yes' only * if hashtree validation isn't disabled and the passed-in hashtree * error mode is AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE. @@ -203,7 +236,9 @@ typedef struct { * PARTUUID=$(ANDROID_VBMETA_PARTUUID) before substitution so it * will end up pointing to the vbmeta partition for the verified * slot. If there is no vbmeta partition it will point to the boot - * partition of the verified slot. + * partition of the verified slot. If the flag + * AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION is used, this is not + * set. * * androidboot.vbmeta.avb_version: This is set to the decimal value * of AVB_VERSION_MAJOR followed by a dot followed by the decimal @@ -228,6 +263,15 @@ typedef struct { * appropriate system partition is substituted in. Note that none of * the androidboot.* options mentioned above will be set. * + * The |resolved_hashtree_error_mode| is the the value of the passed + * avb_slot_verify()'s |hashtree_error_mode| parameter except that it never has + * the value AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO. If this value was + * passed in, then the restart/eio state machine is used resulting in + * |resolved_hashtree_error_mode| being set to either + * AVB_HASHTREE_ERROR_MODE_RESTART or AVB_HASHTREE_ERROR_MODE_EIO. If set to + * AVB_HASHTREE_ERROR_MODE_EIO the boot loader should present a RED warning + * screen for the user to click through before continuing to boot. + * * This struct may grow in the future without it being considered an * ABI break. */ @@ -239,6 +283,7 @@ typedef struct { size_t num_loaded_partitions; char* cmdline; uint64_t rollback_indexes[AVB_MAX_NUMBER_OF_ROLLBACK_INDEX_LOCATIONS]; + AvbHashtreeErrorMode resolved_hashtree_error_mode; } AvbSlotVerifyData; /* Calculates a digest of all vbmeta images in |data| using @@ -282,12 +327,8 @@ void avb_slot_verify_data_free(AvbSlotVerifyData* data); * ignore verification errors which is something needed in the * UNLOCKED state. See the AvbSlotVerifyFlags enumeration for details. * - * The |hashtree_error_mode| parameter should be set to the desired - * error handling mode when hashtree validation fails inside the - * HLOS. This value isn't used by libavb per se - it is forwarded to - * the HLOS through the androidboot.veritymode and - * androidboot.vbmeta.invalidate_on_error cmdline parameters. See the - * AvbHashtreeErrorMode enumeration for details. + * The |hashtree_error_mode| parameter should be set to the desired error + * handling mode. See the AvbHashtreeErrorMode enumeration for details. * * Also note that |out_data| is never set if * AVB_SLOT_VERIFY_RESULT_ERROR_OOM, AVB_SLOT_VERIFY_RESULT_ERROR_IO, |