apkdmverity: dm-verity over apk
apkdmverity is a program that create a dm-verity block device over an
apk that is signed with the APK signature scheme V4. The merkle tree
comes from the *.idsig file generated as part of the signing scheme.
In the context of Microdroid, this program will be used to keep the
integrity of APK inside Microdroid because the APK is stored in a
filesystem that is served by the host Android. Any tampering happening
outside of Microdroid is manifested as an IO error inside Microdroid.
The dm-verity block device will then be mounted at /mnt/apk by zipfuse.
It is not yet decided to merge apkdmverity into zipfuse. It might be
good for saving storage and memory, but right now let's keep them
separate for easy testing.
This CL doesn't have Android.bp. Building and and testing for Android
will be the next step once this lands.
Bug: 189785765
Test: cargo test
Change-Id: I482028a7350162dc55d1cdb35183cd34ea8c18fe
diff --git a/apkverity/src/dm/sys.rs b/apkverity/src/dm/sys.rs
new file mode 100644
index 0000000..f623a2b
--- /dev/null
+++ b/apkverity/src/dm/sys.rs
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+use bitflags::bitflags;
+
+// UAPI for device mapper can be found at include/uapi/linux/dm-ioctl.h
+
+pub const DM_IOCTL: u8 = 0xfd;
+
+#[repr(u16)]
+#[allow(non_camel_case_types)]
+#[allow(dead_code)]
+pub enum Cmd {
+ DM_VERSION = 0,
+ DM_REMOVE_ALL,
+ DM_LIST_DEVICES,
+ DM_DEV_CREATE,
+ DM_DEV_REMOVE,
+ DM_DEV_RENAME,
+ DM_DEV_SUSPEND,
+ DM_DEV_STATUS,
+ DM_DEV_WAIT,
+ DM_TABLE_LOAD,
+ DM_TABLE_CLEAR,
+ DM_TABLE_DEPS,
+ DM_TABLE_STATUS,
+ DM_LIST_VERSIONS,
+ DM_TARGET_MSG,
+ DM_DEV_SET_GEOMETRY,
+}
+
+#[repr(C)]
+pub struct DmIoctl {
+ pub version: [u32; 3],
+ pub data_size: u32,
+ pub data_start: u32,
+ pub target_count: u32,
+ pub open_count: i32,
+ pub flags: Flag,
+ pub event_nr: u32,
+ pub padding: u32,
+ pub dev: u64,
+ pub name: [u8; DM_NAME_LEN],
+ pub uuid: [u8; DM_UUID_LEN],
+ pub data: [u8; 7],
+}
+
+pub const DM_VERSION_MAJOR: u32 = 4;
+pub const DM_VERSION_MINOR: u32 = 0;
+pub const DM_VERSION_PATCHLEVEL: u32 = 0;
+
+pub const DM_NAME_LEN: usize = 128;
+pub const DM_UUID_LEN: usize = 129;
+pub const DM_MAX_TYPE_NAME: usize = 16;
+
+bitflags! {
+ pub struct Flag: u32 {
+ const DM_READONLY_FLAG = 1 << 0;
+ const DM_SUSPEND_FLAG = 1 << 1;
+ const DM_PERSISTENT_DEV_FLAG = 1 << 3;
+ const DM_STATUS_TABLE_FLAG = 1 << 4;
+ const DM_ACTIVE_PRESENT_FLAG = 1 << 5;
+ const DM_INACTIVE_PRESENT_FLAG = 1 << 6;
+ const DM_BUFFER_FULL_FLAG = 1 << 8;
+ const DM_SKIP_BDGET_FLAG = 1 << 9;
+ const DM_SKIP_LOCKFS_FLAG = 1 << 10;
+ const DM_NOFLUSH_FLAG = 1 << 11;
+ const DM_QUERY_INACTIVE_TABLE_FLAG = 1 << 12;
+ const DM_UEVENT_GENERATED_FLAG = 1 << 13;
+ const DM_UUID_FLAG = 1 << 14;
+ const DM_SECURE_DATA_FLAG = 1 << 15;
+ const DM_DATA_OUT_FLAG = 1 << 16;
+ const DM_DEFERRED_REMOVE = 1 << 17;
+ const DM_INTERNAL_SUSPEND_FLAG = 1 << 18;
+ }
+}