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Commit 807f4700 authored by Mohamad Ayyash's avatar Mohamad Ayyash
Browse files

fs_mgr_verity: Add support for squashfs 



- Cleanup the code to get filesystem size in a block device
- Add support to reading size of squashfs in a block device

Change-Id: I3848a705ed4dc2fc9afad20331f0fdecfee545c5
Signed-off-by: default avatarMohamad Ayyash <mkayyash@google.com>
parent 33c2ad37

fs_mgr/Android.mk

+3 −3
Original line number Diff line number Diff line
@@ -8,8 +8,8 @@ LOCAL_SRC_FILES:= fs_mgr.c fs_mgr_verity.c fs_mgr_fstab.c 
LOCAL_C_INCLUDES := $(LOCAL_PATH)/include



LOCAL_MODULE:= libfs_mgr

LOCAL_STATIC_LIBRARIES := liblogwrap libmincrypt libext4_utils_static

LOCAL_C_INCLUDES += system/extras/ext4_utils

LOCAL_STATIC_LIBRARIES := liblogwrap libmincrypt libext4_utils_static libsquashfs_utils

LOCAL_C_INCLUDES += system/extras/ext4_utils system/extras/squashfs_utils

LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include

LOCAL_CFLAGS := -Werror
@@ -34,7 +34,7 @@ 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

LOCAL_STATIC_LIBRARIES := libfs_mgr liblogwrap libcutils liblog libc libmincrypt libext4_utils_static libsquashfs_utils

LOCAL_CXX_STL := libc++_static



LOCAL_CFLAGS := -Werror

fs_mgr/fs_mgr_verity.c

+36 −23
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ 
#include "mincrypt/sha256.h"



#include "ext4_sb.h"

#include "squashfs_utils.h"



#include "fs_mgr_priv.h"

#include "fs_mgr_priv_verity.h"
@@ -138,7 +139,19 @@ out: 
    return retval;

}



static int get_target_device_size(char *blk_device, uint64_t *device_size)

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;
@@ -171,11 +184,11 @@ static int get_target_device_size(char *blk_device, uint64_t *device_size) 
    return 0;

}



static int read_verity_metadata(char *block_device, char **signature, char **table)

static int read_verity_metadata(uint64_t device_size, char *block_device, char **signature,

        char **table)

{

    unsigned magic_number;

    unsigned table_length;

    uint64_t device_length;

    int protocol_version;

    int device;

    int retval = FS_MGR_SETUP_VERITY_FAIL;
@@ -188,12 +201,7 @@ static int read_verity_metadata(char *block_device, char **signature, char **tab 
        goto out;

    }



    // find the start of the verity metadata

    if (get_target_device_size(block_device, &device_length) < 0) {

        ERROR("Could not get target device size.\n");

        goto out;

    }

    if (TEMP_FAILURE_RETRY(lseek64(device, device_length, SEEK_SET)) < 0) {

    if (TEMP_FAILURE_RETRY(lseek64(device, device_size, SEEK_SET)) < 0) {

        ERROR("Could not seek to start of verity metadata block.\n");

        goto out;

    }
@@ -214,8 +222,7 @@ static int read_verity_metadata(char *block_device, char **signature, char **tab 
#endif



    if (magic_number != VERITY_METADATA_MAGIC_NUMBER) {

        ERROR("Couldn't find verity metadata at offset %"PRIu64"!\n",

              device_length);

        ERROR("Couldn't find verity metadata at offset %"PRIu64"!\n", device_size);

        goto out;

    }
@@ -316,17 +323,12 @@ 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, char *blockdev, int fd, char *table,

static int load_verity_table(struct dm_ioctl *io, char *name, uint64_t device_size, int fd, char *table,

        int mode)

{

    char *verity_params;

    char *buffer = (char*) io;

    size_t bufsize;

    uint64_t device_size = 0;



    if (get_target_device_size(blockdev, &device_size) < 0) {

        return -1;

    }



    verity_ioctl_init(io, name, DM_STATUS_TABLE_FLAG);
@@ -798,6 +800,7 @@ int fs_mgr_setup_verity(struct fstab_rec *fstab) { 
    char *verity_blk_name = 0;

    char *verity_table = 0;

    char *verity_table_signature = 0;

    uint64_t device_size = 0;



    _Alignas(struct dm_ioctl) char buffer[DM_BUF_SIZE];

    struct dm_ioctl *io = (struct dm_ioctl *) buffer;
@@ -807,16 +810,26 @@ int fs_mgr_setup_verity(struct fstab_rec *fstab) { 
    io->flags |= 1;

    io->target_count = 1;



    // check to ensure that the verity device is ext4

    // TODO: support non-ext4 filesystems

    if (strcmp(fstab->fs_type, "ext4")) {

        ERROR("Cannot verify non-ext4 device (%s)", fstab->fs_type);

    // check the verity device's filesystem

    if (!strcmp(fstab->fs_type, "ext4")) {

        if (ext4_get_target_device_size(fstab->blk_device, &device_size) < 0) {

            ERROR("Failed to get ext4 fs size on %s.", fstab->blk_device);

            return retval;

        }

    } else if (!strcmp(fstab->fs_type, "squashfs")) {

        if (squashfs_get_target_device_size(fstab->blk_device, &device_size) < 0) {

            ERROR("Failed to get squashfs fs size on %s.", fstab->blk_device);

            return retval;

        }

    } else {

        ERROR("%s: Unsupported filesystem for verity.", fstab->fs_type);

        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(fstab->blk_device,

    retval = read_verity_metadata(device_size,

                                  fstab->blk_device,

                                  &verity_table_signature,

                                  &verity_table);

    if (retval < 0) {
@@ -861,7 +874,7 @@ int fs_mgr_setup_verity(struct fstab_rec *fstab) { 
    INFO("Enabling dm-verity for %s (mode %d)\n",  mount_point, mode);



    // load the verity mapping table

    if (load_verity_table(io, mount_point, fstab->blk_device, fd, verity_table,

    if (load_verity_table(io, mount_point, device_size, fd, verity_table,

            mode) < 0) {

        goto out;

    }

init/Android.mk

+1 −0
Original line number Diff line number Diff line
@@ -58,6 +58,7 @@ LOCAL_UNSTRIPPED_PATH := $(TARGET_ROOT_OUT_UNSTRIPPED) 
LOCAL_STATIC_LIBRARIES := \

    libinit \

    libfs_mgr \

    libsquashfs_utils \

    liblogwrap \

    libcutils \

    libbase \