adb: use libfec in disable-verity (8ad80763) · Commits · e / os / android_system_core

adb/Android.mk

+4 −0

Original line number	Diff line number	Diff line
		@@ -294,11 +294,15 @@ LOCAL_STATIC_LIBRARIES := \
		libadbd \
		libbase \
		libfs_mgr \
		libfec \
		libfec_rs \
		liblog \
		libmincrypt \
		libselinux \
		libext4_utils_static \
		libsquashfs_utils \
		libcutils \
		libbase \
		libcrypto_static

		include $(BUILD_EXECUTABLE)

adb/set_verity_enable_state_service.cpp

+19 −83

Original line number	Diff line number	Diff line
		@@ -28,10 +28,11 @@

		#include "adb.h"
		#include "adb_io.h"
		#include "ext4_sb.h"
		#include "fs_mgr.h"
		#include "remount_service.h"

		#include "fec/io.h"

		#define FSTAB_PREFIX "/fstab."
		struct fstab *fstab;

		@@ -41,115 +42,50 @@ static const bool kAllowDisableVerity = true;
		static const bool kAllowDisableVerity = false;
		#endif

		static int get_target_device_size(int fd, const 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 = adb_open(blk_device, O_RDONLY \| O_CLOEXEC);
		if (data_device < 0) {
		WriteFdFmt(fd, "Error opening block device (%s)\n", strerror(errno));
		return -1;
		}

		if (lseek64(data_device, 1024, SEEK_SET) < 0) {
		WriteFdFmt(fd, "Error seeking to superblock\n");
		adb_close(data_device);
		return -1;
		}

		if (adb_read(data_device, &sb, sizeof(sb)) != sizeof(sb)) {
		WriteFdFmt(fd, "Error reading superblock\n");
		adb_close(data_device);
		return -1;
		}

		ext4_parse_sb(&sb, &info);
		*device_size = info.len;

		adb_close(data_device);
		return 0;
		}

		/* Turn verity on/off */
		static int set_verity_enabled_state(int fd, const char *block_device,
		const char* mount_point, bool enable)
		{
		uint32_t magic_number;
		const uint32_t new_magic = enable ? VERITY_METADATA_MAGIC_NUMBER
		: VERITY_METADATA_MAGIC_DISABLE;
		uint64_t device_length = 0;
		int device = -1;
		int retval = -1;

		if (!make_block_device_writable(block_device)) {
		WriteFdFmt(fd, "Could not make block device %s writable (%s).\n",
		block_device, strerror(errno));
		goto errout;
		return -1;
		}

		device = adb_open(block_device, O_RDWR \| O_CLOEXEC);
		if (device == -1) {
		WriteFdFmt(fd, "Could not open block device %s (%s).\n", block_device, strerror(errno));
		WriteFdFmt(fd, "Maybe run adb remount?\n");
		goto errout;
		}
		fec::io fh(block_device, O_RDWR);

		// find the start of the verity metadata
		if (get_target_device_size(fd, (char*)block_device, &device_length) < 0) {
		WriteFdFmt(fd, "Could not get target device size.\n");
		goto errout;
		if (!fh) {
		WriteFdFmt(fd, "Could not open block device %s (%s).\n", block_device, strerror(errno));
		WriteFdFmt(fd, "Maybe run adb root?\n");
		return -1;
		}

		if (lseek64(device, device_length, SEEK_SET) < 0) {
		WriteFdFmt(fd, "Could not seek to start of verity metadata block.\n");
		goto errout;
		}
		fec_verity_metadata metadata;

		// check the magic number
		if (adb_read(device, &magic_number, sizeof(magic_number)) != sizeof(magic_number)) {
		WriteFdFmt(fd, "Couldn't read magic number!\n");
		goto errout;
		if (!fh.get_verity_metadata(metadata)) {
		WriteFdFmt(fd, "Couldn't find verity metadata!\n");
		return -1;
		}

		if (!enable && magic_number == VERITY_METADATA_MAGIC_DISABLE) {
		if (!enable && metadata.disabled) {
		WriteFdFmt(fd, "Verity already disabled on %s\n", mount_point);
		goto errout;
		return -1;
		}

		if (enable && magic_number == VERITY_METADATA_MAGIC_NUMBER) {
		if (enable && !metadata.disabled) {
		WriteFdFmt(fd, "Verity already enabled on %s\n", mount_point);
		goto errout;
		}

		if (magic_number != VERITY_METADATA_MAGIC_NUMBER
		&& magic_number != VERITY_METADATA_MAGIC_DISABLE) {
		WriteFdFmt(fd, "Couldn't find verity metadata at offset %" PRIu64 "!\n", device_length);
		goto errout;
		}

		if (lseek64(device, device_length, SEEK_SET) < 0) {
		WriteFdFmt(fd, "Could not seek to start of verity metadata block.\n");
		goto errout;
		return -1;
		}

		if (adb_write(device, &new_magic, sizeof(new_magic)) != sizeof(new_magic)) {
		if (!fh.set_verity_status(enable)) {
		WriteFdFmt(fd, "Could not set verity %s flag on device %s with error %s\n",
		enable ? "enabled" : "disabled",
		block_device, strerror(errno));
		goto errout;
		return -1;
		}

		WriteFdFmt(fd, "Verity %s on %s\n", enable ? "enabled" : "disabled", mount_point);
		retval = 0;
		errout:
		if (device != -1)
		adb_close(device);
		return retval;
		return 0;
		}

		void set_verity_enabled_state_service(int fd, void* cookie)