[parted-devel] [PATCH v4] dos: improve MBR signature generation
Jim Meyering
jim at meyering.net
Thu Oct 10 03:31:54 UTC 2013
On Wed, Oct 2, 2013 at 3:35 AM, Jonathan Liu <net147 at gmail.com> wrote:
...
> + dos: improve MBR signature generation by extracting the
> + generate_random_uint32 function used for generating FAT serial numbers
> + into a common header and reusing it. Previously tv_usec in struct
> + timeval from gettimeofday() was used which didn't provide enough
> + precision to fill an unsigned 32-bit integer and wasn't really random.
> + A check is also added to avoid returning zero which may be interpreted
> + as no FAT serial number or no MBR signature.
...
Thanks again.
I've tested that patch and shortened/revised your NEWS entry to this:
dos: the range of random MBR signature values was artificially limited
to 0..999999, which mistakenly included 0. Now, we use the full 32-bit
range, but exclude 0.
I'll push the attached tomorrow.
-------------- next part --------------
From 70aa35b2b4d2e723fe82ac3184e5921a52be73ab Mon Sep 17 00:00:00 2001
From: Jonathan Liu <net147 at gmail.com>
Date: Fri, 4 Oct 2013 07:32:12 -0700
Subject: [PATCH 1/2] dos: improve MBR signature generation
Using tv_usec in struct timeval from gettimeofday() doesn't provide
enough precision to fill an unsigned 32-bit integer and isn't really
random. It it always less than one million when using the GNU C library
while an unsigned 32-bit integer ranges between 0 and 4294967295.
In FAT filesystem creation, parted already uses a better random
generator, so move that code into a common function and use it
for MS-DOS MBR signature generation.
* libparted/fs/r/fat/fat.c (_gen_new_serial_number): Remove.
(fat_create): Use generate_random_uint32 instead of
_gen_new_serial_number.
* libparted/labels/dos.c (generate_random_id): Remove.
(msdos_write): Use generate_random_uint32 instead of
generate_random_id.
* libparted/labels/misc.h (generate_random_uint32): New function.
Created from _gen_new_serial_number in libparted/fs/r/fat/fat.c with
additional check to avoid returning zero, which may be interpreted
as no FAT serial number or no MBR signature.
---
NEWS | 4 ++++
libparted/fs/r/fat/fat.c | 19 ++-----------------
libparted/labels/dos.c | 12 +-----------
libparted/labels/misc.h | 21 +++++++++++++++++++++
4 files changed, 28 insertions(+), 28 deletions(-)
diff --git a/NEWS b/NEWS
index 98f7c6e..50faf4d 100644
--- a/NEWS
+++ b/NEWS
@@ -23,6 +23,10 @@ GNU parted NEWS -*- outline -*-
partprobe now tells the kernel to forget about any partitions
on a device that has no recognizable partition table.
+ dos: the range of random MBR signature values was artificially limited
+ to 0..999999, which mistakenly included 0. Now, we use the full 32-bit
+ range, but exclude 0.
+
** Changes in behavior
parted -l no longer lists device-mapper devices other than
diff --git a/libparted/fs/r/fat/fat.c b/libparted/fs/r/fat/fat.c
index 2ab9279..c8e4552 100644
--- a/libparted/fs/r/fat/fat.c
+++ b/libparted/fs/r/fat/fat.c
@@ -18,10 +18,10 @@
#include <config.h>
#include <string.h>
-#include <uuid/uuid.h>
#include "fat.h"
#include "calc.h"
+#include "../../../labels/misc.h"
PedFileSystem*
fat_alloc (const PedGeometry* geom)
@@ -202,21 +202,6 @@ fat_root_dir_clear (PedFileSystem* fs)
fs_info->root_dir_sector_count);
}
-/* hack: use the ext2 uuid library to generate a reasonably random (hopefully
- * with /dev/random) number. Unfortunately, we can only use 4 bytes of it
- */
-static uint32_t
-_gen_new_serial_number (void)
-{
- union {
- uuid_t uuid;
- uint32_t i;
- } uu32;
-
- uuid_generate (uu32.uuid);
- return uu32.i;
-}
-
PedFileSystem*
fat_create (PedGeometry* geom, FatType fat_type, PedTimer* timer)
{
@@ -316,7 +301,7 @@ fat_create (PedGeometry* geom, FatType fat_type, PedTimer* timer)
return 0;
}
- fs_info->serial_number = _gen_new_serial_number ();
+ fs_info->serial_number = generate_random_uint32 ();
if (!fat_boot_sector_set_boot_code (&fs_info->boot_sector))
goto error_free_buffers;
diff --git a/libparted/labels/dos.c b/libparted/labels/dos.c
index b8c161f..6bddd79 100644
--- a/libparted/labels/dos.c
+++ b/libparted/labels/dos.c
@@ -1236,16 +1236,6 @@ write_extended_partitions (const PedDisk* disk)
return write_empty_table (disk, ext_part->geom.start);
}
-static inline uint32_t generate_random_id (void)
-{
- struct timeval tv;
- int rc;
- rc = gettimeofday(&tv, NULL);
- if (rc == -1)
- return 0;
- return (uint32_t)(tv.tv_usec & 0xFFFFFFFFUL);
-}
-
static int
msdos_write (const PedDisk* disk)
{
@@ -1267,7 +1257,7 @@ msdos_write (const PedDisk* disk)
/* If there is no unique identifier, generate a random one */
if (!table->mbr_signature)
- table->mbr_signature = generate_random_id();
+ table->mbr_signature = generate_random_uint32 ();
memset (table->partitions, 0, sizeof (table->partitions));
table->magic = PED_CPU_TO_LE16 (MSDOS_MAGIC);
diff --git a/libparted/labels/misc.h b/libparted/labels/misc.h
index c2ccea1..c039c5f 100644
--- a/libparted/labels/misc.h
+++ b/libparted/labels/misc.h
@@ -16,6 +16,27 @@
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
+#include <inttypes.h>
+#include <uuid/uuid.h>
+
+/* hack: use the ext2 uuid library to generate a reasonably random (hopefully
+ * with /dev/random) number. Unfortunately, we can only use 4 bytes of it.
+ * We make sure to avoid returning zero which may be interpreted as no FAT
+ * serial number or no MBR signature.
+ */
+static inline uint32_t
+generate_random_uint32 (void)
+{
+ union {
+ uuid_t uuid;
+ uint32_t i;
+ } uu32;
+
+ uuid_generate (uu32.uuid);
+
+ return uu32.i > 0 ? uu32.i : 0xffffffff;
+}
+
/* Return nonzero if FS_TYPE_NAME starts with "linux-swap".
This must match the NUL-terminated "linux-swap" as well
as "linux-swap(v0)" and "linux-swap(v1)". */
--
1.8.4.299.gb3e7d24
From 9b8f632e102c0d9e2187f0c8d8205862540cdcd1 Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering at fb.com>
Date: Wed, 9 Oct 2013 17:44:05 -0700
Subject: [PATCH 2/2] bootstrap: update to latest from gnulib
---
bootstrap | 159 ++++++++++++++++++++++++++++++++++----------------------------
1 file changed, 87 insertions(+), 72 deletions(-)
diff --git a/bootstrap b/bootstrap
index 48181c9..e31d17d 100755
--- a/bootstrap
+++ b/bootstrap
@@ -1,6 +1,6 @@
#! /bin/sh
# Print a version string.
-scriptversion=2012-07-19.14; # UTC
+scriptversion=2013-08-15.22; # UTC
# Bootstrap this package from checked-out sources.
@@ -140,20 +140,21 @@ po_download_command_format2=\
"wget --mirror -nd -q -np -A.po -P '%s' \
http://translationproject.org/latest/%s/"
+# Prefer a non-empty tarname (4th argument of AC_INIT if given), else
+# fall back to the package name (1st argument with munging)
extract_package_name='
- /^AC_INIT(/{
- /.*,.*,.*, */{
- s///
- s/[][]//g
- s/)$//
+ /^AC_INIT(\[*/{
+ s///
+ /^[^,]*,[^,]*,[^,]*,[ []*\([^][ ,)]\)/{
+ s//\1/
+ s/[],)].*//
p
q
}
- s/AC_INIT(\[*//
- s/]*,.*//
+ s/[],)].*//
s/^GNU //
y/ABCDEFGHIJKLMNOPQRSTUVWXYZ/abcdefghijklmnopqrstuvwxyz/
- s/[^A-Za-z0-9_]/-/g
+ s/[^abcdefghijklmnopqrstuvwxyz0123456789_]/-/g
p
}
'
@@ -208,12 +209,16 @@ bootstrap_sync=false
# Use git to update gnulib sources
use_git=true
+check_exists() {
+ ($1 --version </dev/null) >/dev/null 2>&1
+ test $? -lt 126
+}
+
# find_tool ENVVAR NAMES...
# -------------------------
# Search for a required program. Use the value of ENVVAR, if set,
-# otherwise find the first of the NAMES that can be run (i.e.,
-# supports --version). If found, set ENVVAR to the program name,
-# die otherwise.
+# otherwise find the first of the NAMES that can be run.
+# If found, set ENVVAR to the program name, die otherwise.
#
# FIXME: code duplication, see also gnu-web-doc-update.
find_tool ()
@@ -223,27 +228,21 @@ find_tool ()
find_tool_names=$@
eval "find_tool_res=\$$find_tool_envvar"
if test x"$find_tool_res" = x; then
- for i
- do
- if ($i --version </dev/null) >/dev/null 2>&1; then
- find_tool_res=$i
- break
+ for i; do
+ if check_exists $i; then
+ find_tool_res=$i
+ break
fi
done
- else
- find_tool_error_prefix="\$$find_tool_envvar: "
fi
- test x"$find_tool_res" != x \
- || die "one of these is required: $find_tool_names"
- ($find_tool_res --version </dev/null) >/dev/null 2>&1 \
- || die "${find_tool_error_prefix}cannot run $find_tool_res --version"
+ if test x"$find_tool_res" = x; then
+ warn_ "one of these is required: $find_tool_names;"
+ die "alternatively set $find_tool_envvar to a compatible tool"
+ fi
eval "$find_tool_envvar=\$find_tool_res"
eval "export $find_tool_envvar"
}
-# Find sha1sum, named gsha1sum on MacPorts, and shasum on Mac OS X 10.6.
-find_tool SHA1SUM sha1sum gsha1sum shasum
-
# Override the default configuration, if necessary.
# Make sure that bootstrap.conf is sourced from the current directory
# if we were invoked as "sh bootstrap".
@@ -255,12 +254,12 @@ esac
# Extra files from gnulib, which override files from other sources.
test -z "${gnulib_extra_files}" && \
gnulib_extra_files="
- $build_aux/install-sh
- $build_aux/mdate-sh
- $build_aux/texinfo.tex
- $build_aux/depcomp
- $build_aux/config.guess
- $build_aux/config.sub
+ build-aux/install-sh
+ build-aux/mdate-sh
+ build-aux/texinfo.tex
+ build-aux/depcomp
+ build-aux/config.guess
+ build-aux/config.sub
doc/INSTALL
"
@@ -306,34 +305,34 @@ if test -n "$checkout_only_file" && test ! -r "$checkout_only_file"; then
die "Bootstrapping from a non-checked-out distribution is risky."
fi
-# Ensure that lines starting with ! sort last, per gitignore conventions
-# for whitelisting exceptions after a more generic blacklist pattern.
-sort_patterns() {
- sort -u "$@" | sed '/^!/ {
- H
- d
- }
- $ {
- P
- x
- s/^\n//
- }' | sed '/^$/d'
+# Strip blank and comment lines to leave significant entries.
+gitignore_entries() {
+ sed '/^#/d; /^$/d' "$@"
}
-# If $STR is not already on a line by itself in $FILE, insert it,
-# sorting the new contents of the file and replacing $FILE with the result.
-insert_sorted_if_absent() {
+# If $STR is not already on a line by itself in $FILE, insert it at the start.
+# Entries are inserted at the start of the ignore list to ensure existing
+# entries starting with ! are not overridden. Such entries support
+# whitelisting exceptions after a more generic blacklist pattern.
+insert_if_absent() {
file=$1
str=$2
test -f $file || touch $file
- echo "$str" | sort_patterns - $file | cmp -s - $file > /dev/null \
- || { echo "$str" | sort_patterns - $file > $file.bak \
- && mv $file.bak $file; } \
- || die "insert_sorted_if_absent $file $str: failed"
+ test -r $file || die "Error: failed to read ignore file: $file"
+ duplicate_entries=$(gitignore_entries $file | sort | uniq -d)
+ if [ "$duplicate_entries" ] ; then
+ die "Error: Duplicate entries in $file: " $duplicate_entries
+ fi
+ linesold=$(gitignore_entries $file | wc -l)
+ linesnew=$( { echo "$str"; cat $file; } | gitignore_entries | sort -u | wc -l)
+ if [ $linesold != $linesnew ] ; then
+ { echo "$str" | cat - $file > $file.bak && mv $file.bak $file; } \
+ || die "insert_if_absent $file $str: failed"
+ fi
}
# Adjust $PATTERN for $VC_IGNORE_FILE and insert it with
-# insert_sorted_if_absent.
+# insert_if_absent.
insert_vc_ignore() {
vc_ignore_file="$1"
pattern="$2"
@@ -344,7 +343,7 @@ insert_vc_ignore() {
# .gitignore entry.
pattern=$(echo "$pattern" | sed s,^,/,);;
esac
- insert_sorted_if_absent "$vc_ignore_file" "$pattern"
+ insert_if_absent "$vc_ignore_file" "$pattern"
}
# Die if there is no AC_CONFIG_AUX_DIR($build_aux) line in configure.ac.
@@ -468,8 +467,7 @@ check_versions() {
if [ "$req_ver" = "-" ]; then
# Merely require app to exist; not all prereq apps are well-behaved
# so we have to rely on $? rather than get_version.
- $app --version >/dev/null 2>&1
- if [ 126 -le $? ]; then
+ if ! check_exists $app; then
warn_ "Error: '$app' not found"
ret=1
fi
@@ -502,6 +500,12 @@ print_versions() {
# can't depend on column -t
}
+# Find sha1sum, named gsha1sum on MacPorts, shasum on Mac OS X 10.6.
+# Also find the compatible sha1 utility on the BSDs
+if test x"$SKIP_PO" = x; then
+ find_tool SHA1SUM sha1sum gsha1sum shasum sha1
+fi
+
use_libtool=0
# We'd like to use grep -E, to see if any of LT_INIT,
# AC_PROG_LIBTOOL, AM_PROG_LIBTOOL is used in configure.ac,
@@ -550,10 +554,10 @@ fi
echo "$0: Bootstrapping from checked-out $package sources..."
# See if we can use gnulib's git-merge-changelog merge driver.
-if test -d .git && (git --version) >/dev/null 2>/dev/null ; then
+if $use_git && test -d .git && check_exists git; then
if git config merge.merge-changelog.driver >/dev/null ; then
:
- elif (git-merge-changelog --version) >/dev/null 2>/dev/null ; then
+ elif check_exists git-merge-changelog; then
echo "$0: initializing git-merge-changelog driver"
git config merge.merge-changelog.name 'GNU-style ChangeLog merge driver'
git config merge.merge-changelog.driver 'git-merge-changelog %O %A %B'
@@ -573,13 +577,17 @@ git_modules_config () {
test -f .gitmodules && git config --file .gitmodules "$@"
}
-gnulib_path=$(git_modules_config submodule.gnulib.path)
-test -z "$gnulib_path" && gnulib_path=gnulib
+if $use_git; then
+ gnulib_path=$(git_modules_config submodule.gnulib.path)
+ test -z "$gnulib_path" && gnulib_path=gnulib
+fi
-# Get gnulib files.
+# Get gnulib files. Populate $GNULIB_SRCDIR, possibly updating a
+# submodule, for use in the rest of the script.
case ${GNULIB_SRCDIR--} in
-)
+ # Note that $use_git is necessarily true in this case.
if git_modules_config submodule.gnulib.url >/dev/null; then
echo "$0: getting gnulib files..."
git submodule init || exit $?
@@ -600,8 +608,8 @@ case ${GNULIB_SRCDIR--} in
GNULIB_SRCDIR=$gnulib_path
;;
*)
- # Use GNULIB_SRCDIR as a reference.
- if test -d "$GNULIB_SRCDIR"/.git && \
+ # Use GNULIB_SRCDIR directly or as a reference.
+ if $use_git && test -d "$GNULIB_SRCDIR"/.git && \
git_modules_config submodule.gnulib.url >/dev/null; then
echo "$0: getting gnulib files..."
if git submodule -h|grep -- --reference > /dev/null; then
@@ -627,12 +635,19 @@ case ${GNULIB_SRCDIR--} in
;;
esac
+# $GNULIB_SRCDIR now points to the version of gnulib to use, and
+# we no longer need to use git or $gnulib_path below here.
+
if $bootstrap_sync; then
cmp -s "$0" "$GNULIB_SRCDIR/build-aux/bootstrap" || {
echo "$0: updating bootstrap and restarting..."
+ case $(sh -c 'echo "$1"' -- a) in
+ a) ignored=--;;
+ *) ignored=ignored;;
+ esac
exec sh -c \
'cp "$1" "$2" && shift && exec "${CONFIG_SHELL-/bin/sh}" "$@"' \
- -- "$GNULIB_SRCDIR/build-aux/bootstrap" \
+ $ignored "$GNULIB_SRCDIR/build-aux/bootstrap" \
"$0" "$@" --no-bootstrap-sync
}
fi
@@ -680,11 +695,10 @@ update_po_files() {
cksum_file="$ref_po_dir/$po.s1"
if ! test -f "$cksum_file" ||
! test -f "$po_dir/$po.po" ||
- ! $SHA1SUM -c --status "$cksum_file" \
- < "$new_po" > /dev/null; then
+ ! $SHA1SUM -c "$cksum_file" < "$new_po" > /dev/null 2>&1; then
echo "$me: updated $po_dir/$po.po..."
cp "$new_po" "$po_dir/$po.po" \
- && $SHA1SUM < "$new_po" > "$cksum_file"
+ && $SHA1SUM < "$new_po" > "$cksum_file" || return
fi
done
}
@@ -889,20 +903,21 @@ find "$m4_base" "$source_base" \
-depth \( -name '*.m4' -o -name '*.[ch]' \) \
-type l -xtype l -delete > /dev/null 2>&1
+# Invoke autoreconf with --force --install to ensure upgrades of tools
+# such as ylwrap.
+AUTORECONFFLAGS="--verbose --install --force -I $m4_base $ACLOCAL_FLAGS"
+
# Some systems (RHEL 5) are using ancient autotools, for which the
# --no-recursive option had not been invented. Detect that lack and
# omit the option when it's not supported. FIXME in 2017: remove this
# hack when RHEL 5 autotools are updated, or when they become irrelevant.
-no_recursive=
case $($AUTORECONF --help) in
- *--no-recursive*) no_recursive=--no-recursive;;
+ *--no-recursive*) AUTORECONFFLAGS="$AUTORECONFFLAGS --no-recursive";;
esac
# Tell autoreconf not to invoke autopoint or libtoolize; they were run above.
-echo "running: AUTOPOINT=true LIBTOOLIZE=true " \
- "$AUTORECONF --verbose --install $no_recursive -I $m4_base $ACLOCAL_FLAGS"
-AUTOPOINT=true LIBTOOLIZE=true \
- $AUTORECONF --verbose --install $no_recursive -I $m4_base $ACLOCAL_FLAGS \
+echo "running: AUTOPOINT=true LIBTOOLIZE=true $AUTORECONF $AUTORECONFFLAGS"
+AUTOPOINT=true LIBTOOLIZE=true $AUTORECONF $AUTORECONFFLAGS \
|| die "autoreconf failed"
# Get some extra files from gnulib, overriding existing files.
--
1.8.4.299.gb3e7d24
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