Replace manual dm ioctls with libdm.
This mostly 1:1 replaces manual ioctls to device-mapper with calls to
libdm. There were two exceptions:
(1) There is a very old table-load-retry loop to workaround issues with
umount (b/7220345). This loop has been preserved, however, it now
includes DM_DEV_CREATE as well as DM_TABLE_LOAD.
(2) There was some ancient code to set DM_DEV_GEOMETRY for obb
dm-devices. This never did anything since geometry must be set after
loading a table. When setting it before (as vold was doing), the
subsequent DM_TABLE_LOAD will clear it.
Bug: 132206403
Test: FBE device boots
FBE device w/ metadata encryption boots
FDE device boots
atest StorageManagerIntegrationTest
Change-Id: Ib6db6b47329f093ac7084edaf604eddace8b9ac6
diff --git a/MetadataCrypt.cpp b/MetadataCrypt.cpp
index deb7194..573d4cc 100644
--- a/MetadataCrypt.cpp
+++ b/MetadataCrypt.cpp
@@ -23,19 +23,17 @@
#include <vector>
#include <fcntl.h>
-#include <sys/ioctl.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/types.h>
-#include <linux/dm-ioctl.h>
-
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/properties.h>
#include <android-base/unique_fd.h>
#include <cutils/fs.h>
#include <fs_mgr.h>
+#include <libdm/dm.h>
#include "Checkpoint.h"
#include "EncryptInplace.h"
@@ -45,13 +43,12 @@
#include "Utils.h"
#include "VoldUtil.h"
-#define DM_CRYPT_BUF_SIZE 4096
#define TABLE_LOAD_RETRIES 10
-#define DEFAULT_KEY_TARGET_TYPE "default-key"
using android::fs_mgr::FstabEntry;
using android::fs_mgr::GetEntryForMountPoint;
using android::vold::KeyBuffer;
+using namespace android::dm;
static const std::string kDmNameUserdata = "userdata";
@@ -146,16 +143,6 @@
} // namespace vold
} // namespace android
-static KeyBuffer default_key_params(const std::string& real_blkdev, const KeyBuffer& key) {
- KeyBuffer hex_key;
- if (android::vold::StrToHex(key, hex_key) != android::OK) {
- LOG(ERROR) << "Failed to turn key to hex";
- return KeyBuffer();
- }
- auto res = KeyBuffer() + "AES-256-XTS " + hex_key + " " + real_blkdev.c_str() + " 0";
- return res;
-}
-
static bool get_number_of_sectors(const std::string& real_blkdev, uint64_t* nr_sec) {
if (android::vold::GetBlockDev512Sectors(real_blkdev, nr_sec) != android::OK) {
PLOG(ERROR) << "Unable to measure size of " << real_blkdev;
@@ -164,86 +151,35 @@
return true;
}
-static struct dm_ioctl* dm_ioctl_init(char* buffer, size_t buffer_size, const std::string& dm_name) {
- if (buffer_size < sizeof(dm_ioctl)) {
- LOG(ERROR) << "dm_ioctl buffer too small";
- return nullptr;
- }
-
- memset(buffer, 0, buffer_size);
- struct dm_ioctl* io = (struct dm_ioctl*)buffer;
- io->data_size = buffer_size;
- io->data_start = sizeof(struct dm_ioctl);
- io->version[0] = 4;
- io->version[1] = 0;
- io->version[2] = 0;
- io->flags = 0;
- dm_name.copy(io->name, sizeof(io->name));
- return io;
-}
-
static bool create_crypto_blk_dev(const std::string& dm_name, uint64_t nr_sec,
- const std::string& target_type, const KeyBuffer& crypt_params,
+ const std::string& real_blkdev, const KeyBuffer& key,
std::string* crypto_blkdev) {
- android::base::unique_fd dm_fd(
- TEMP_FAILURE_RETRY(open("/dev/device-mapper", O_RDWR | O_CLOEXEC, 0)));
- if (dm_fd == -1) {
- PLOG(ERROR) << "Cannot open device-mapper";
+ auto& dm = DeviceMapper::Instance();
+
+ KeyBuffer hex_key_buffer;
+ if (android::vold::StrToHex(key, hex_key_buffer) != android::OK) {
+ LOG(ERROR) << "Failed to turn key to hex";
return false;
}
- alignas(struct dm_ioctl) char buffer[DM_CRYPT_BUF_SIZE];
- auto io = dm_ioctl_init(buffer, sizeof(buffer), dm_name);
- if (!io || ioctl(dm_fd.get(), DM_DEV_CREATE, io) != 0) {
- PLOG(ERROR) << "Cannot create dm-crypt device " << dm_name;
- return false;
- }
+ std::string hex_key(hex_key_buffer.data(), hex_key_buffer.size());
- // Get the device status, in particular, the name of its device file
- io = dm_ioctl_init(buffer, sizeof(buffer), dm_name);
- if (ioctl(dm_fd.get(), DM_DEV_STATUS, io) != 0) {
- PLOG(ERROR) << "Cannot retrieve dm-crypt device status " << dm_name;
- return false;
- }
- *crypto_blkdev = std::string() + "/dev/block/dm-" +
- std::to_string((io->dev & 0xff) | ((io->dev >> 12) & 0xfff00));
-
- io = dm_ioctl_init(buffer, sizeof(buffer), dm_name);
- size_t paramix = io->data_start + sizeof(struct dm_target_spec);
- size_t nullix = paramix + crypt_params.size();
- size_t endix = (nullix + 1 + 7) & 8; // Add room for \0 and align to 8 byte boundary
-
- if (endix > sizeof(buffer)) {
- LOG(ERROR) << "crypt_params too big for DM_CRYPT_BUF_SIZE";
- return false;
- }
-
- io->target_count = 1;
- auto tgt = (struct dm_target_spec*)(buffer + io->data_start);
- tgt->status = 0;
- tgt->sector_start = 0;
- tgt->length = nr_sec;
- target_type.copy(tgt->target_type, sizeof(tgt->target_type));
- memcpy(buffer + paramix, crypt_params.data(),
- std::min(crypt_params.size(), sizeof(buffer) - paramix));
- buffer[nullix] = '\0';
- tgt->next = endix;
+ DmTable table;
+ table.Emplace<DmTargetDefaultKey>(0, nr_sec, "AES-256-XTS", hex_key, real_blkdev, 0);
for (int i = 0;; i++) {
- if (ioctl(dm_fd.get(), DM_TABLE_LOAD, io) == 0) {
+ if (dm.CreateDevice(dm_name, table)) {
break;
}
if (i + 1 >= TABLE_LOAD_RETRIES) {
- PLOG(ERROR) << "DM_TABLE_LOAD ioctl failed";
+ LOG(ERROR) << "Could not create default-key device " << dm_name;
return false;
}
- PLOG(INFO) << "DM_TABLE_LOAD ioctl failed, retrying";
+ PLOG(INFO) << "Could not create default-key device, retrying";
usleep(500000);
}
- // Resume this device to activate it
- io = dm_ioctl_init(buffer, sizeof(buffer), dm_name);
- if (ioctl(dm_fd.get(), DM_DEV_SUSPEND, io)) {
- PLOG(ERROR) << "Cannot resume dm-crypt device " << dm_name;
+ if (!dm.GetDmDevicePathByName(dm_name, crypto_blkdev)) {
+ LOG(ERROR) << "Cannot retrieve default-key device status " << dm_name;
return false;
}
return true;
@@ -267,8 +203,7 @@
uint64_t nr_sec;
if (!get_number_of_sectors(data_rec->blk_device, &nr_sec)) return false;
std::string crypto_blkdev;
- if (!create_crypto_blk_dev(kDmNameUserdata, nr_sec, DEFAULT_KEY_TARGET_TYPE,
- default_key_params(data_rec->blk_device, key), &crypto_blkdev))
+ if (!create_crypto_blk_dev(kDmNameUserdata, nr_sec, data_rec->blk_device, key, &crypto_blkdev))
return false;
// FIXME handle the corrupt case
if (needs_encrypt) {