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platform_system_core
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am 2dcf97a2: am 234aedfa: am b8cc70a9: Merge "Error correction: Use libfec in fs_mgr" 

* commit '2dcf97a245eb3683bb9a3f213189c80e1b279277':
  Error correction: Use libfec in fs_mgr
This commit is contained in:
Sami Tolvanen 2015-10-16 12:08:20 +00:00 committed by Android Git Automerger
parent 30b893ae9e 2dcf97a245
commit ef9afe4bf8
3 changed files with 212 additions and 278 deletions
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58
fs_mgr/Android.mk
View File

@ -1,49 +1,59 @@
# Copyright 2011 The Android Open Source Project
LOCAL_PATH:= $(call my-dir)
common_static_libraries := \
liblogwrap \
libfec \
libfec_rs \
libbase \
libmincrypt \
libcrypto_static \
libext4_utils_static \
libsquashfs_utils
include $(CLEAR_VARS)
LOCAL_SRC_FILES:= fs_mgr.c fs_mgr_verity.cpp fs_mgr_fstab.c
LOCAL_SRC_FILES += fs_mgr_format.c fs_mgr_slotselect.c
LOCAL_C_INCLUDES := $(LOCAL_PATH)/include \
LOCAL_CLANG := true
LOCAL_SANITIZE := integer
LOCAL_SRC_FILES:= \
fs_mgr.c \
fs_mgr_format.c \
fs_mgr_fstab.c \
fs_mgr_slotselect.c \
fs_mgr_verity.cpp
LOCAL_C_INCLUDES := \
$(LOCAL_PATH)/include \
system/vold \
system/extras/ext4_utils \
external/openssl/include
external/openssl/include \
bootable/recovery
LOCAL_MODULE:= libfs_mgr
LOCAL_STATIC_LIBRARIES := liblogwrap libmincrypt libext4_utils_static libsquashfs_utils libbase
LOCAL_C_INCLUDES += system/extras/ext4_utils system/extras/squashfs_utils \
bootable/recovery
LOCAL_STATIC_LIBRARIES := $(common_static_libraries)
LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
LOCAL_CFLAGS := -Werror
ifneq (,$(filter userdebug,$(TARGET_BUILD_VARIANT)))
LOCAL_CFLAGS += -DALLOW_ADBD_DISABLE_VERITY=1
endif
include $(BUILD_STATIC_LIBRARY)
include $(CLEAR_VARS)
LOCAL_CLANG := true
LOCAL_SANITIZE := integer
LOCAL_SRC_FILES:= fs_mgr_main.c
LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
LOCAL_MODULE:= fs_mgr
LOCAL_MODULE_TAGS := optional
LOCAL_FORCE_STATIC_EXECUTABLE := true
LOCAL_MODULE_PATH := $(TARGET_ROOT_OUT)/sbin
LOCAL_UNSTRIPPED_PATH := $(TARGET_ROOT_OUT_UNSTRIPPED)
LOCAL_STATIC_LIBRARIES := libfs_mgr liblogwrap libcutils liblog libc libmincrypt libext4_utils_static libsquashfs_utils libbase
LOCAL_STATIC_LIBRARIES += libsparse_static libz libselinux
LOCAL_STATIC_LIBRARIES := libfs_mgr \
$(common_static_libraries) \
libcutils \
liblog \
libc \
libsparse_static \
libz \
libselinux
LOCAL_CXX_STL := libc++_static
LOCAL_CFLAGS := -Werror
include $(BUILD_EXECUTABLE)

429
fs_mgr/fs_mgr_verity.cpp
View File

@ -38,8 +38,7 @@
#include "mincrypt/sha.h"
#include "mincrypt/sha256.h"
#include "ext4_sb.h"
#include "squashfs_utils.h"
#include "fec/io.h"
#include "fs_mgr.h"
#include "fs_mgr_priv.h"
@ -47,11 +46,19 @@
#define FSTAB_PREFIX "/fstab."
#define VERITY_METADATA_SIZE 32768
#define VERITY_TABLE_RSA_KEY "/verity_key"
#define VERITY_TABLE_HASH_IDX 8
#define VERITY_TABLE_SALT_IDX 9
#define VERITY_TABLE_OPT_RESTART "restart_on_corruption"
#define VERITY_TABLE_OPT_LOGGING "ignore_corruption"
#define VERITY_TABLE_OPT_IGNZERO "ignore_zero_blocks"
#define VERITY_TABLE_OPT_FEC_FORMAT \
"use_fec_from_device %s fec_start %" PRIu64 " fec_blocks %" PRIu64 \
" fec_roots %u " VERITY_TABLE_OPT_IGNZERO
#define VERITY_TABLE_OPT_FEC_ARGS 9
#define METADATA_MAGIC 0x01564c54
#define METADATA_TAG_MAX_LENGTH 63
#define METADATA_EOD "eod"
@ -92,7 +99,7 @@ static RSAPublicKey *load_key(const char *path)
}
if (!fread(key, sizeof(*key), 1, f)) {
ERROR("Could not read key!");
ERROR("Could not read key!\n");
fclose(f);
free(key);
return NULL;
@ -109,7 +116,8 @@ static RSAPublicKey *load_key(const char *path)
return key;
}
static int verify_table(char *signature, char *table, int table_length)
static int verify_table(const uint8_t *signature, const char *table,
uint32_t table_length)
{
RSAPublicKey *key;
uint8_t hash_buf[SHA256_DIGEST_SIZE];
@ -121,17 +129,17 @@ static int verify_table(char *signature, char *table, int table_length)
// Now get the public key from the keyfile
key = load_key(VERITY_TABLE_RSA_KEY);
if (!key) {
ERROR("Couldn't load verity keys");
ERROR("Couldn't load verity keys\n");
goto out;
}
// verify the result
if (!RSA_verify(key,
(uint8_t*) signature,
signature,
RSANUMBYTES,
(uint8_t*) hash_buf,
SHA256_DIGEST_SIZE)) {
ERROR("Couldn't verify table.");
ERROR("Couldn't verify table\n");
goto out;
}
@ -142,11 +150,11 @@ out:
return retval;
}
static int invalidate_table(char *table, int table_length)
static int invalidate_table(char *table, size_t table_length)
{
int n = 0;
int idx = 0;
int cleared = 0;
size_t n = 0;
size_t idx = 0;
size_t cleared = 0;
while (n < table_length) {
if (table[n++] == ' ') {
@ -169,177 +177,6 @@ static int invalidate_table(char *table, int table_length)
return -1;
}
static int squashfs_get_target_device_size(char *blk_device, uint64_t *device_size)
{
struct squashfs_info sq_info;
if (squashfs_parse_sb(blk_device, &sq_info) >= 0) {
*device_size = sq_info.bytes_used_4K_padded;
return 0;
} else {
return -1;
}
}
static int ext4_get_target_device_size(char *blk_device, uint64_t *device_size)
{
int data_device;
struct ext4_super_block sb;
struct fs_info info;
info.len = 0; /* Only len is set to 0 to ask the device for real size. */
data_device = TEMP_FAILURE_RETRY(open(blk_device, O_RDONLY | O_CLOEXEC));
if (data_device == -1) {
ERROR("Error opening block device (%s)", strerror(errno));
return -1;
}
if (TEMP_FAILURE_RETRY(lseek64(data_device, 1024, SEEK_SET)) < 0) {
ERROR("Error seeking to superblock");
close(data_device);
return -1;
}
if (!android::base::ReadFully(data_device, &sb, sizeof(sb))) {
ERROR("Error reading superblock");
close(data_device);
return -1;
}
ext4_parse_sb(&sb, &info);
*device_size = info.len;
close(data_device);
return 0;
}
static int get_fs_size(char *fs_type, char *blk_device, uint64_t *device_size) {
if (!strcmp(fs_type, "ext4")) {
if (ext4_get_target_device_size(blk_device, device_size) < 0) {
ERROR("Failed to get ext4 fs size on %s.", blk_device);
return -1;
}
} else if (!strcmp(fs_type, "squashfs")) {
if (squashfs_get_target_device_size(blk_device, device_size) < 0) {
ERROR("Failed to get squashfs fs size on %s.", blk_device);
return -1;
}
} else {
ERROR("%s: Unsupported filesystem for verity.", fs_type);
return -1;
}
return 0;
}
static int read_verity_metadata(uint64_t device_size, char *block_device, char **signature,
char **table)
{
unsigned magic_number;
unsigned table_length;
int protocol_version;
int device;
int retval = FS_MGR_SETUP_VERITY_FAIL;
*signature = NULL;
if (table) {
*table = NULL;
}
device = TEMP_FAILURE_RETRY(open(block_device, O_RDONLY | O_CLOEXEC));
if (device == -1) {
ERROR("Could not open block device %s (%s).\n", block_device, strerror(errno));
goto out;
}
if (TEMP_FAILURE_RETRY(lseek64(device, device_size, SEEK_SET)) < 0) {
ERROR("Could not seek to start of verity metadata block.\n");
goto out;
}
// check the magic number
if (!android::base::ReadFully(device, &magic_number, sizeof(magic_number))) {
ERROR("Couldn't read magic number!\n");
goto out;
}
#ifdef ALLOW_ADBD_DISABLE_VERITY
if (magic_number == VERITY_METADATA_MAGIC_DISABLE) {
retval = FS_MGR_SETUP_VERITY_DISABLED;
INFO("Attempt to cleanly disable verity - only works in USERDEBUG");
goto out;
}
#endif
if (magic_number != VERITY_METADATA_MAGIC_NUMBER) {
ERROR("Couldn't find verity metadata at offset %" PRIu64 "!\n", device_size);
goto out;
}
// check the protocol version
if (!android::base::ReadFully(device, &protocol_version,
sizeof(protocol_version))) {
ERROR("Couldn't read verity metadata protocol version!\n");
goto out;
}
if (protocol_version != 0) {
ERROR("Got unknown verity metadata protocol version %d!\n", protocol_version);
goto out;
}
// get the signature
*signature = (char*) malloc(RSANUMBYTES);
if (!*signature) {
ERROR("Couldn't allocate memory for signature!\n");
goto out;
}
if (!android::base::ReadFully(device, *signature, RSANUMBYTES)) {
ERROR("Couldn't read signature from verity metadata!\n");
goto out;
}
if (!table) {
retval = FS_MGR_SETUP_VERITY_SUCCESS;
goto out;
}
// get the size of the table
if (!android::base::ReadFully(device, &table_length, sizeof(table_length))) {
ERROR("Couldn't get the size of the verity table from metadata!\n");
goto out;
}
// get the table + null terminator
*table = static_cast<char*>(malloc(table_length + 1));
if (!*table) {
ERROR("Couldn't allocate memory for verity table!\n");
goto out;
}
if (!android::base::ReadFully(device, *table, table_length)) {
ERROR("Couldn't read the verity table from metadata!\n");
goto out;
}
(*table)[table_length] = 0;
retval = FS_MGR_SETUP_VERITY_SUCCESS;
out:
if (device != -1)
close(device);
if (retval != FS_MGR_SETUP_VERITY_SUCCESS) {
free(*signature);
*signature = NULL;
if (table) {
free(*table);
*table = NULL;
}
}
return retval;
}
static void verity_ioctl_init(struct dm_ioctl *io, char *name, unsigned flags)
{
memset(io, 0, DM_BUF_SIZE);
@ -379,8 +216,76 @@ static int get_verity_device_name(struct dm_ioctl *io, char *name, int fd, char
return 0;
}
static int load_verity_table(struct dm_ioctl *io, char *name, uint64_t device_size, int fd, char *table,
int mode)
struct verity_table_params {
const char *table;
int mode;
struct fec_ecc_metadata ecc;
const char *ecc_dev;
};
typedef bool (*format_verity_table_func)(char *buf, const size_t bufsize,
const struct verity_table_params *params);
static bool format_verity_table(char *buf, const size_t bufsize,
const struct verity_table_params *params)
{
const char *mode_flag = NULL;
int res = -1;
if (params->mode == VERITY_MODE_RESTART) {
mode_flag = VERITY_TABLE_OPT_RESTART;
} else if (params->mode == VERITY_MODE_LOGGING) {
mode_flag = VERITY_TABLE_OPT_LOGGING;
}
if (params->ecc.valid) {
if (mode_flag) {
res = snprintf(buf, bufsize,
"%s %u %s " VERITY_TABLE_OPT_FEC_FORMAT,
params->table, 1 + VERITY_TABLE_OPT_FEC_ARGS, mode_flag, params->ecc_dev,
params->ecc.start / FEC_BLOCKSIZE, params->ecc.blocks, params->ecc.roots);
} else {
res = snprintf(buf, bufsize,
"%s %u " VERITY_TABLE_OPT_FEC_FORMAT,
params->table, VERITY_TABLE_OPT_FEC_ARGS, params->ecc_dev,
params->ecc.start / FEC_BLOCKSIZE, params->ecc.blocks, params->ecc.roots);
}
} else if (mode_flag) {
res = snprintf(buf, bufsize, "%s 2 " VERITY_TABLE_OPT_IGNZERO " %s", params->table,
mode_flag);
} else {
res = strlcpy(buf, params->table, bufsize);
}
if (res < 0 || (size_t)res >= bufsize) {
ERROR("Error building verity table; insufficient buffer size?\n");
return false;
}
return true;
}
static bool format_legacy_verity_table(char *buf, const size_t bufsize,
const struct verity_table_params *params)
{
int res;
if (params->mode == VERITY_MODE_EIO) {
res = strlcpy(buf, params->table, bufsize);
} else {
res = snprintf(buf, bufsize, "%s %d", params->table, params->mode);
}
if (res < 0 || (size_t)res >= bufsize) {
ERROR("Error building verity table; insufficient buffer size?\n");
return false;
}
return true;
}
static int load_verity_table(struct dm_ioctl *io, char *name, uint64_t device_size, int fd,
const struct verity_table_params *params, format_verity_table_func format)
{
char *verity_params;
char *buffer = (char*) io;
@ -390,35 +295,32 @@ static int load_verity_table(struct dm_ioctl *io, char *name, uint64_t device_si
struct dm_target_spec *tgt = (struct dm_target_spec *) &buffer[sizeof(struct dm_ioctl)];
// set tgt arguments here
// set tgt arguments
io->target_count = 1;
tgt->status=0;
tgt->sector_start=0;
tgt->length=device_size/512;
tgt->status = 0;
tgt->sector_start = 0;
tgt->length = device_size / 512;
strcpy(tgt->target_type, "verity");
// build the verity params here
// build the verity params
verity_params = buffer + sizeof(struct dm_ioctl) + sizeof(struct dm_target_spec);
bufsize = DM_BUF_SIZE - (verity_params - buffer);
if (mode == VERITY_MODE_EIO) {
// allow operation with older dm-verity drivers that are unaware
// of the mode parameter by omitting it; this also means that we
// cannot use logging mode with these drivers, they always cause
// an I/O error for corrupted blocks
strcpy(verity_params, table);
} else if (snprintf(verity_params, bufsize, "%s %d", table, mode) < 0) {
if (!format(verity_params, bufsize, params)) {
ERROR("Failed to format verity parameters\n");
return -1;
}
INFO("loading verity table: '%s'", verity_params);
// set next target boundary
verity_params += strlen(verity_params) + 1;
verity_params = (char*) (((unsigned long)verity_params + 7) & ~8);
verity_params = (char*)(((unsigned long)verity_params + 7) & ~8);
tgt->next = verity_params - buffer;
// send the ioctl to load the verity table
if (ioctl(fd, DM_TABLE_LOAD, io)) {
ERROR("Error loading verity table (%s)", strerror(errno));
ERROR("Error loading verity table (%s)\n", strerror(errno));
return -1;
}
@ -703,28 +605,31 @@ out:
static int compare_last_signature(struct fstab_rec *fstab, int *match)
{
char tag[METADATA_TAG_MAX_LENGTH + 1];
char *signature = NULL;
int fd = -1;
int rc = -1;
off64_t offset = 0;
struct fec_handle *f = NULL;
struct fec_verity_metadata verity;
uint8_t curr[SHA256_DIGEST_SIZE];
uint8_t prev[SHA256_DIGEST_SIZE];
off64_t offset = 0;
uint64_t device_size;
*match = 1;
// get verity filesystem size
if (get_fs_size(fstab->fs_type, fstab->blk_device, &device_size) < 0) {
ERROR("Failed to get filesystem size\n");
if (fec_open(&f, fstab->blk_device, O_RDONLY, FEC_VERITY_DISABLE,
FEC_DEFAULT_ROOTS) == -1) {
ERROR("Failed to open '%s' (%s)\n", fstab->blk_device,
strerror(errno));
return rc;
}
// read verity metadata
if (fec_verity_get_metadata(f, &verity) == -1) {
ERROR("Failed to get verity metadata '%s' (%s)\n", fstab->blk_device,
strerror(errno));
goto out;
}
if (read_verity_metadata(device_size, fstab->blk_device, &signature, NULL) < 0) {
ERROR("Failed to read verity signature from %s\n", fstab->mount_point);
goto out;
}
SHA256_hash(signature, RSANUMBYTES, curr);
SHA256_hash(verity.signature, RSANUMBYTES, curr);
if (snprintf(tag, sizeof(tag), VERITY_LASTSIG_TAG "_%s",
basename(fstab->mount_point)) >= (int)sizeof(tag)) {
@ -766,12 +671,7 @@ static int compare_last_signature(struct fstab_rec *fstab, int *match)
rc = 0;
out:
free(signature);
if (fd != -1) {
close(fd);
}
fec_close(f);
return rc;
}
@ -884,6 +784,7 @@ int fs_mgr_update_verity_state(fs_mgr_verity_state_callback callback)
{
alignas(dm_ioctl) char buffer[DM_BUF_SIZE];
bool use_state = true;
bool use_state_for_device = true;
char fstab_filename[PROPERTY_VALUE_MAX + sizeof(FSTAB_PREFIX)];
char *mount_point;
char propbuf[PROPERTY_VALUE_MAX];
@ -928,10 +829,12 @@ int fs_mgr_update_verity_state(fs_mgr_verity_state_callback callback)
continue;
}
use_state_for_device = use_state;
if (use_state) {
if (get_verity_state_offset(&fstab->recs[i], &offset) < 0 ||
read_verity_state(fstab->recs[i].verity_loc, offset, &mode) < 0) {
continue;
use_state_for_device = false;
}
}
@ -946,7 +849,7 @@ int fs_mgr_update_verity_state(fs_mgr_verity_state_callback callback)
status = &buffer[io->data_start + sizeof(struct dm_target_spec)];
if (use_state && *status == 'C') {
if (use_state_for_device && *status == 'C') {
if (write_verity_state(fstab->recs[i].verity_loc, offset,
VERITY_MODE_LOGGING) < 0) {
continue;
@ -972,87 +875,105 @@ out:
return rc;
}
int fs_mgr_setup_verity(struct fstab_rec *fstab) {
int fs_mgr_setup_verity(struct fstab_rec *fstab)
{
int retval = FS_MGR_SETUP_VERITY_FAIL;
int fd = -1;
int mode;
char *verity_blk_name = 0;
char *verity_table = 0;
char *verity_table_signature = 0;
int verity_table_length = 0;
uint64_t device_size = 0;
char *invalid_table = NULL;
char *verity_blk_name = NULL;
struct fec_handle *f = NULL;
struct fec_verity_metadata verity;
struct verity_table_params params;
alignas(dm_ioctl) char buffer[DM_BUF_SIZE];
struct dm_ioctl *io = (struct dm_ioctl *) buffer;
char *mount_point = basename(fstab->mount_point);
// get verity filesystem size
if (get_fs_size(fstab->fs_type, fstab->blk_device, &device_size) < 0) {
if (fec_open(&f, fstab->blk_device, O_RDONLY, FEC_VERITY_DISABLE,
FEC_DEFAULT_ROOTS) < 0) {
ERROR("Failed to open '%s' (%s)\n", fstab->blk_device,
strerror(errno));
return retval;
}
// read the verity block at the end of the block device
// send error code up the chain so we can detect attempts to disable verity
retval = read_verity_metadata(device_size,
fstab->blk_device,
&verity_table_signature,
&verity_table);
if (retval < 0) {
// read verity metadata
if (fec_verity_get_metadata(f, &verity) < 0) {
ERROR("Failed to get verity metadata '%s' (%s)\n", fstab->blk_device,
strerror(errno));
goto out;
}
retval = FS_MGR_SETUP_VERITY_FAIL;
verity_table_length = strlen(verity_table);
#ifdef ALLOW_ADBD_DISABLE_VERITY
if (verity.disabled) {
retval = FS_MGR_SETUP_VERITY_DISABLED;
INFO("Attempt to cleanly disable verity - only works in USERDEBUG\n");
goto out;
}
#endif
// read ecc metadata
if (fec_ecc_get_metadata(f, &params.ecc) < 0) {
params.ecc.valid = false;
}
params.ecc_dev = fstab->blk_device;
// get the device mapper fd
if ((fd = open("/dev/device-mapper", O_RDWR)) < 0) {
ERROR("Error opening device mapper (%s)", strerror(errno));
ERROR("Error opening device mapper (%s)\n", strerror(errno));
goto out;
}
// create the device
if (create_verity_device(io, mount_point, fd) < 0) {
ERROR("Couldn't create verity device!");
ERROR("Couldn't create verity device!\n");
goto out;
}
// get the name of the device file
if (get_verity_device_name(io, mount_point, fd, &verity_blk_name) < 0) {
ERROR("Couldn't get verity device number!");
ERROR("Couldn't get verity device number!\n");
goto out;
}
if (load_verity_state(fstab, &mode) < 0) {
if (load_verity_state(fstab, &params.mode) < 0) {
/* if accessing or updating the state failed, switch to the default
* safe mode. This makes sure the device won't end up in an endless
* restart loop, and no corrupted data will be exposed to userspace
* without a warning. */
mode = VERITY_MODE_EIO;
params.mode = VERITY_MODE_EIO;
}
// verify the signature on the table
if (verify_table(verity_table_signature,
verity_table,
verity_table_length) < 0) {
if (mode == VERITY_MODE_LOGGING) {
if (verify_table(verity.signature, verity.table,
verity.table_length) < 0) {
if (params.mode == VERITY_MODE_LOGGING) {
// the user has been warned, allow mounting without dm-verity
retval = FS_MGR_SETUP_VERITY_SUCCESS;
goto out;
}
// invalidate root hash and salt to trigger device-specific recovery
if (invalidate_table(verity_table, verity_table_length) < 0) {
invalid_table = strdup(verity.table);
if (!invalid_table ||
invalidate_table(invalid_table, verity.table_length) < 0) {
goto out;
}
params.table = invalid_table;
} else {
params.table = verity.table;
}
INFO("Enabling dm-verity for %s (mode %d)\n", mount_point, mode);
INFO("Enabling dm-verity for %s (mode %d)\n", mount_point, params.mode);
// load the verity mapping table
if (load_verity_table(io, mount_point, device_size, fd, verity_table,
mode) < 0) {
if (load_verity_table(io, mount_point, verity.data_size, fd, &params,
format_verity_table) < 0 &&
// try the legacy format for backwards compatibility
load_verity_table(io, mount_point, verity.data_size, fd, &params,
format_legacy_verity_table) < 0) {
goto out;
}
@ -1081,8 +1002,8 @@ out:
close(fd);
}
free(verity_table);
free(verity_table_signature);
fec_close(f);
free(invalid_table);
free(verity_blk_name);
return retval;

3
init/Android.mk
View File

@ -84,6 +84,8 @@ LOCAL_UNSTRIPPED_PATH := $(TARGET_ROOT_OUT_UNSTRIPPED)
LOCAL_STATIC_LIBRARIES := \
libinit \
libfs_mgr \
libfec \
libfec_rs \
libsquashfs_utils \
liblogwrap \
libcutils \
@ -94,6 +96,7 @@ LOCAL_STATIC_LIBRARIES := \
libc \
libselinux \
libmincrypt \
libcrypto_static \
libc++_static \
libdl \
libsparse_static \