@@ -212,6 +212,7 @@ export CHECKBASHISMS_PROG="$(type -P checkbashisms)"
export XFS_INFO_PROG="$(type -P xfs_info)"
export DUPEREMOVE_PROG="$(type -P duperemove)"
export CC_PROG="$(type -P cc)"
+export FSVERITY_PROG="$(type -P fsverity)"
# use 'udevadm settle' or 'udevsettle' to wait for lv to be settled.
# newer systems have udevadm command but older systems like RHEL5 don't.
new file mode 100644
@@ -0,0 +1,189 @@
+# SPDX-License-Identifier: GPL-2.0
+# Copyright 2018 Google LLC
+#
+# Functions for setting up and testing fs-verity
+
+_require_scratch_verity()
+{
+ _require_scratch
+ _require_command "$FSVERITY_PROG" fsverity
+
+ if ! _scratch_mkfs_verity &>>$seqres.full; then
+ # ext4: need e2fsprogs v1.44.5 or later (but actually v1.45.2+
+ # is needed for some tests to pass, due to an e2fsck bug)
+ # f2fs: need f2fs-tools v1.11.0 or later
+ _notrun "$FSTYP userspace tools don't support fs-verity"
+ fi
+
+ # Try to mount the filesystem. If this fails then either the kernel
+ # isn't aware of fs-verity, or the mkfs options were not compatible with
+ # verity (e.g. ext4 with block size != PAGE_SIZE).
+ if ! _try_scratch_mount &>>$seqres.full; then
+ _notrun "kernel is unaware of $FSTYP verity feature," \
+ "or mkfs options are not compatible with verity"
+ fi
+ _scratch_unmount
+
+ # The filesystem may be aware of fs-verity but have it disabled by
+ # CONFIG_FS_VERITY=n. Detect support via sysfs.
+ if [ ! -e /sys/fs/$FSTYP/features/verity ]; then
+ _notrun "kernel $FSTYP isn't configured with verity support"
+ fi
+
+ # Merkle tree block size. Currently all filesystems only support
+ # PAGE_SIZE for this. This is also the default for 'fsverity enable'.
+ FSV_BLOCK_SIZE=$(get_page_size)
+}
+
+_scratch_mkfs_verity()
+{
+ case $FSTYP in
+ ext4|f2fs)
+ _scratch_mkfs -O verity
+ ;;
+ *)
+ _notrun "No verity support for $FSTYP"
+ ;;
+ esac
+}
+
+_scratch_mkfs_encrypted_verity()
+{
+ case $FSTYP in
+ ext4)
+ _scratch_mkfs -O encrypt,verity
+ ;;
+ f2fs)
+ # f2fs-tools as of v1.11.0 doesn't allow comma-separated
+ # features with -O. Instead -O must be supplied multiple times.
+ _scratch_mkfs -O encrypt -O verity
+ ;;
+ *)
+ _notrun "$FSTYP not supported in _scratch_mkfs_encrypted_verity"
+ ;;
+ esac
+}
+
+_fsv_scratch_begin_subtest()
+{
+ local msg=$1
+
+ rm -rf "${SCRATCH_MNT:?}"/*
+ echo -e "\n# $msg"
+}
+
+_fsv_enable()
+{
+ $FSVERITY_PROG enable "$@"
+}
+
+_fsv_measure()
+{
+ $FSVERITY_PROG measure "$@" | awk '{print $1}'
+}
+
+# Generate a file, then enable verity on it.
+_fsv_create_enable_file()
+{
+ local file=$1
+ shift
+
+ head -c $((FSV_BLOCK_SIZE * 2)) /dev/zero > "$file"
+ _fsv_enable "$file" "$@"
+}
+
+_fsv_have_hash_algorithm()
+{
+ local hash_alg=$1
+ local test_file=$2
+
+ rm -f $test_file
+ head -c 4096 /dev/zero > $test_file
+ if ! _fsv_enable --hash-alg=$hash_alg $test_file &>> $seqres.full; then
+ # no kernel support
+ return 1
+ fi
+ rm -f $test_file
+ return 0
+}
+
+#
+# _fsv_scratch_corrupt_bytes - Write some bytes to a file, bypassing the filesystem
+#
+# Write the bytes sent on stdin to the given offset in the given file, but do so
+# by writing directly to the extents on the block device, with the filesystem
+# unmounted. This can be used to corrupt a verity file for testing purposes,
+# bypassing the restrictions imposed by the filesystem.
+#
+# The file is assumed to be located on $SCRATCH_DEV.
+#
+_fsv_scratch_corrupt_bytes()
+{
+ local file=$1
+ local offset=$2
+ local lstart lend pstart pend
+ local dd_cmds=()
+ local cmd
+
+ sync # Sync to avoid unwritten extents
+
+ cat > $tmp.bytes
+ local end=$(( offset + $(stat -c %s $tmp.bytes ) ))
+
+ # For each extent that intersects the requested range in order, add a
+ # command that writes the next part of the data to that extent.
+ while read -r lstart lend pstart pend; do
+ lstart=$((lstart * 512))
+ lend=$(((lend + 1) * 512))
+ pstart=$((pstart * 512))
+ pend=$(((pend + 1) * 512))
+
+ if (( lend - lstart != pend - pstart )); then
+ _fail "Logical and physical extent lengths differ for file '$file'"
+ elif (( offset < lstart )); then
+ _fail "Hole in file '$file' at byte $offset. Next extent begins at byte $lstart"
+ elif (( offset < lend )); then
+ local len=$((lend - offset))
+ local seek=$((pstart + (offset - lstart)))
+ dd_cmds+=("head -c $len | dd of=$SCRATCH_DEV oflag=seek_bytes seek=$seek status=none")
+ (( offset += len ))
+ fi
+ done < <($XFS_IO_PROG -r -c "fiemap $offset $((end - offset))" "$file" \
+ | _filter_xfs_io_fiemap)
+
+ if (( offset < end )); then
+ _fail "Extents of file '$file' ended at byte $offset, but needed until $end"
+ fi
+
+ # Execute the commands to write the data
+ _scratch_unmount
+ for cmd in "${dd_cmds[@]}"; do
+ eval "$cmd"
+ done < $tmp.bytes
+ sync # Sync to flush the block device's pagecache
+ _scratch_mount
+}
+
+#
+# _fsv_scratch_corrupt_merkle_tree - Corrupt a file's Merkle tree
+#
+# Like _fsv_scratch_corrupt_bytes(), but this corrupts the file's fs-verity
+# Merkle tree. The offset is given as a byte offset into the Merkle tree.
+#
+_fsv_scratch_corrupt_merkle_tree()
+{
+ local file=$1
+ local offset=$2
+
+ case $FSTYP in
+ ext4|f2fs)
+ # ext4 and f2fs store the Merkle tree after the file contents
+ # itself, starting at the next 65536-byte aligned boundary.
+ (( offset += ($(stat -c %s $file) + 65535) & ~65535 ))
+ _fsv_scratch_corrupt_bytes $file $offset
+ ;;
+ *)
+ _fail "_fsv_scratch_corrupt_merkle_tree() unimplemented on $FSTYP"
+ ;;
+ esac
+}