fs_mgr: Add support for at-boot verification (863442bb) · Commits · e / os / android_system_core

fs_mgr/fs_mgr_fstab.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -72,6 +72,7 @@ static struct flag_list fs_mgr_flags[] = {
		{ "recoveryonly",MF_RECOVERYONLY },
		{ "swapprio=", MF_SWAPPRIO },
		{ "zramsize=", MF_ZRAMSIZE },
		{ "verifyatboot", MF_VERIFYATBOOT },
		{ "verify", MF_VERIFY },
		{ "noemulatedsd", MF_NOEMULATEDSD },
		{ "notrim", MF_NOTRIM },

fs_mgr/fs_mgr_priv.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -85,6 +85,7 @@ __BEGIN_DECLS
		#define MF_FORCEFDEORFBE 0x10000
		#define MF_LATEMOUNT 0x20000
		#define MF_NOFAIL 0x40000
		#define MF_VERIFYATBOOT 0x80000

		#define DM_BUF_SIZE 4096

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 <cutils/properties.h>
		#include <logwrap/logwrap.h>

		@@ -72,6 +73,8 @@
		#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)

		@@ -213,6 +216,16 @@ 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);
		@@ -614,6 +627,30 @@ 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];
		@@ -908,6 +945,7 @@ int fs_mgr_setup_verity(struct fstab_rec *fstab)
		struct fec_handle *f = NULL;
		struct fec_verity_metadata verity;
		struct verity_table_params params = { .table = NULL };
		bool verified_at_boot = false;

		alignas(dm_ioctl) char buffer[DM_BUF_SIZE];
		struct dm_ioctl io = (struct dm_ioctl ) buffer;
		@@ -1045,10 +1083,26 @@ 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 (test_access(fstab->blk_device) < 0) {