Merge "fs_mgr: Add support for at-boot verification" (82db553d) · Commits · e / os / android_system_core

fs_mgr/fs_mgr_verity.cpp

+57 −3

Original line number	Diff line number	Diff line
		@@ -31,6 +31,7 @@

		#include <android-base/file.h>
		#include <android-base/strings.h>
		#include <android-base/unique_fd.h>
		#include <crypto_utils/android_pubkey.h>
		#include <cutils/properties.h>
		#include <logwrap/logwrap.h>
		@@ -73,6 +74,8 @@
		#define VERITY_KMSG_RESTART "dm-verity device corrupted"
		#define VERITY_KMSG_BUFSIZE 1024

		#define READ_BUF_SIZE 4096

		#define __STRINGIFY(x) #x
		#define STRINGIFY(x) __STRINGIFY(x)

		@@ -205,6 +208,16 @@ static int create_verity_device(struct dm_ioctl io, char name, int fd)
		return 0;
		}

		static int destroy_verity_device(struct dm_ioctl io, char name, int fd)
		{
		verity_ioctl_init(io, name, 0);
		if (ioctl(fd, DM_DEV_REMOVE, io)) {
		ERROR("Error removing device mapping (%s)", strerror(errno));
		return -1;
		}
		return 0;
		}

		static int get_verity_device_name(struct dm_ioctl io, char name, int fd, char **dev_name)
		{
		verity_ioctl_init(io, name, 0);
		@@ -606,6 +619,30 @@ out:
		return rc;
		}

		static int read_partition(const char *path, uint64_t size)
		{
		char buf[READ_BUF_SIZE];
		ssize_t size_read;
		android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(path, O_RDONLY \| O_CLOEXEC)));

		if (fd == -1) {
		ERROR("Failed to open %s: %s\n", path, strerror(errno));
		return -errno;
		}

		while (size) {
		size_read = TEMP_FAILURE_RETRY(read(fd, buf, READ_BUF_SIZE));
		if (size_read == -1) {
		ERROR("Error in reading partition %s: %s\n", path,
		strerror(errno));
		return -errno;
		}
		size -= size_read;
		}

		return 0;
		}

		static int compare_last_signature(struct fstab_rec fstab, int match)
		{
		char tag[METADATA_TAG_MAX_LENGTH + 1];
		@@ -904,6 +941,7 @@ int fs_mgr_setup_verity(struct fstab_rec *fstab, bool verify_dev)
		alignas(dm_ioctl) char buffer[DM_BUF_SIZE];
		struct dm_ioctl io = (struct dm_ioctl ) buffer;
		char *mount_point = basename(fstab->mount_point);
		bool verified_at_boot = false;

		if (fec_open(&f, fstab->blk_device, O_RDONLY, FEC_VERITY_DISABLE,
		FEC_DEFAULT_ROOTS) < 0) {
		@@ -1037,10 +1075,26 @@ loaded:
		// mark the underlying block device as read-only
		fs_mgr_set_blk_ro(fstab->blk_device);

		// Verify the entire partition in one go
		// If there is an error, allow it to mount as a normal verity partition.
		if (fstab->fs_mgr_flags & MF_VERIFYATBOOT) {
		INFO("Verifying partition %s at boot\n", fstab->blk_device);
		int err = read_partition(verity_blk_name, verity.data_size);
		if (!err) {
		INFO("Verified verity partition %s at boot\n", fstab->blk_device);
		verified_at_boot = true;
		}
		}

		// assign the new verity block device as the block device
		if (!verified_at_boot) {
		free(fstab->blk_device);
		fstab->blk_device = verity_blk_name;
		verity_blk_name = 0;
		} else if (destroy_verity_device(io, mount_point, fd) < 0) {
		ERROR("Failed to remove verity device %s\n", mount_point);
		goto out;
		}

		// make sure we've set everything up properly
		if (verify_dev && test_access(fstab->blk_device) < 0) {