MFC r366064, r366065, r366215: sbin/fsck_msdosfs: Fix an integer
overflow on 32-bit platforms

MFC r345839, r345894, r345897, r345900-r345901, r345976, r346220, r348602, r348767, r348967,
r349047-r349048, r351204-r351205, r351502, r351623, r352364, r356249-r356250, r356313,
r356434, r356628-r356629, r356636, r356657, r357421, r357716, r360359, r360428:

r345839: Assert that q can't be NULL. 'empty' is always non-NULL when DIREMPTY
r345894: Restore the ability of checking and fixing next free
r345897: Restore lfcl when LOSTDIR's chain was corrupted and overwritten
r345900: Implement checking of `.' and `..' entries of subdirectory.
r345901: Fix build.
r345976: Write string constant differently to improve readability.
r346220: Don't cast result from malloc().
r348602: Don't increment cl after increment.
r348767: preen should work independently with alwaysyes and alwaysno.
r348967: Avoid out of boundary access when checking invalid long filenames.
r349047: Blankspace. No actual code change.
r349048: In ask(): override default option if any of alwaysyes/alwaysno/rdonly is
r351204: Remove redundant check and wrong fix: fat.c checks already take care
r351205: Use calloc().
r351502: Comment boot block checks and perform additional sanity checks:
r351623: Remove unneeded blank line. No functional change.
r352364: Avoid mixing cluster numbers and sector numbers. Makes code more readable.
r356249: Reduce memory footprint of fsck_msdosfs.
r356250: Revert r356249 for now as it broke GCC builds.
r356313: Reduce memory footprint of fsck_msdosfs.
r356434: fsck_msdosfs.8: document -M.
r356628: Require FAT to occupy at least one sector.
r356629: Apply typo fix from NetBSD, we have already applied all NetBSD changes so
r356636: Correct off-by-two issue when determining FAT type.
r356657: Tighten FAT checks and fix off-by-one error in corner case.
r357421: Diff reduction against NetBSD, no functional change.
r357716: Use humanize_number to format available and bad space sizes.
r360359: Fix a bug with dirty file system handling.
r360428: Do not overflow when calculating file system size.

MFC r351802:

Correct overflow logic in fullpath().

Obtained from: OpenBSD

MFC r345647:

Distinguish between lseek errors and read errores.

MFC r336236: Detect and handle invalid number of FATs.

MFC r335696,r335697:

Detect exFAT filesystems and abort if found and tighten BPB sanity
check.

Obtained from: Android https://android-review.googlesource.com/61827

MFC r335655:

Fix division by zero when reading boot block by postponing division
until it is necessary and after we validated bytes per sector is non-
zero.

Obtained from: Android https://android-review.googlesource.com/c/platform/external/fsck_msdos/+/36362

MFC r335559:

Don't bail out when we find primary and secondary bootblocks miscompare.
We do not have code to fix this situation, and the mismatch does not
prevent the kernel driver from consuming the file system, and some factory
formatted SD cards seem to have a garbage backup block.

This makes the code match to its comments (replacing pfatal with pwarn).

Inspired by: NetBSD r1.13
Inspired by: https://android.googlesource.com/platform/external/fsck_msdos/+/b47b16353f3db228711dded9f7c975b820059ddc

MFC r333098:

Don't bail out from the check if readboot() returns !FSFATAL.

This can happen when the fsinfo signature is invalid, and the
user have choose to fix it, in which case the code would return
FSBOOTMOD (not FSOK but not FSFATAL either).

All other (fatal) cases would return FSFATAL.

Obtained from: Android Open Source Project
Obtained from: https://android.googlesource.com/platform/external/fsck_msdos/+/d8775a29ea7eac2e5f1504dd21da3725b93b3036

MFC r326276:

various: general adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.

MFC r326391: Prevent OOB access on corrupted msdos directories.

Submitted by: Veo Zhang <veo live com>

MFC r314655:

bin: normalize paths using SRCTOP-relative paths or :H when possible

This simplifies make logic/output

MFC r306602:
Mention the version of NetBSD the utility originated from.

PR: 212476
Approved by: bcr (mentor)
Differential Revision: https://reviews.freebsd.org/D8105

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

fsck_msdosfs: Adjust a check.

The on-disk FAT array does not include anything before CLUST_FIRST,
compensate in size check.

Obtained from: NetBSD (CVS Rev. 1.20)
MFC after: 2 weeks

Use macro MAX() from sys/param.h.

MFC after: 2 weeks.

fsck_msdosfs: use NULL instead of zero for pointers.

Merge the projects/release-pkg branch to head.

This allows packaging the base system with pkg(8), including
but not limited to providing the ability to provide upstream
binary update possibilities for non-tier-1 architectures.

This merge is a requirement of the 11.0-RELEASE, and as such,
thank you to everyone that has tested the project branch.

Documentation in build(7) etc. is still somewhat sparse, but
updates to those parts will follow.

Sponsored by: The FreeBSD Foundation

fsck_msdosfs(8): Optimimize memsets

Obtained from: NetBSD (bin/50908)
MFC after: 2 weeks

Add META_MODE support.

Off by default, build behaves normally.
WITH_META_MODE we get auto objdir creation, the ability to
start build from anywhere in the tree.

Still need to add real targets under targets/ to build packages.

Differential Revision: D2796
Reviewed by: brooks imp

Make UEFI booting of 4Kn disks work:
- convert boot1.efi to corrrectly calculate the lba for what the
media reports and convert the size based on what FreeBSD uses.
The existing code would use the 512 byte lba and convert the
size using 4K byte size.
- make fsck_msdosfs read the boot block as 4K so the read doesn't
fail on a 4Kn drive since FreeBSD will error out parition reads
of a block. Make the bpbBytesPerSec check a multiple of 512 since
it can be 512 or 4K depending on the disk. This allows fsck to
pass checking the EFI partition on a 4Kn disk.

To create the EFI file system I used:
newfs_msdos -F 32 -S 4096 -c 1 -m 0xf8 <partition>
This works for booting 512 and 4Kn disks.

Caveat is that loader.efi cannot read the 4Kn EFI partition. This isn't
critical right now since boot1.efi will read loader.efi from the ufs
partition. It looks like loader.efi can be fixed via making some of the
512 bytes reads more flexible. loader.efi doesn't have trouble reading
the ufs partition. This is probably a simple fix.

I now have FreeBSD installed on a system with 4Kn drives and tested the
same code works on 512.

MFC after: 1 week

newfs_msdosfs: Respect FSFIXFAT

Fix some whitespace issues while here.

Obtained from: NetBSD (rev. 1.9)
MFC after: 3 days

msdosfs: Assorted fixes from other BSDs.

When truncating cluster chains fix the length of the cluster head.
http://marc.info/?t=140304310700005&r=1&w=2

Avoid infinite loops in cluster chain linked lists.
http://marc.info/?l=openbsd-tech&m=140275150804337&w=2

Avoid off-by-one on FAT12 filesystems.
http://marc.info/?l=openbsd-tech&m=140234174104724&w=2

Obtained from: NetBSD (from OpenBSD)
MFC after: 1 week

fsck_msdosfs: be a bit more permissive

The free space value in the FSInfo block is merely unitialized when it is
0xffffffff. This fixes a bug found in NetBSD.

It must be noted that we never supported all the checks that NetBSD does
as some of them would cause failures with a freshly created FAT32
from MS-Windows.

While here, bring some space fixes.

Obtained from: NetBSD (rev. 1.22)
MFC after: 3 days

Minor (mostly cosmetic) cleanups

Several whitespace fixes
convert *rootDir from external to static.

Obtained from: NetBSD, OpenBSD (partial)
MFC after: 3 days

Print a newline after the error message.

PR: bin/168447
Submitted by: Boris Kochergin

Make fsck and fsck_msdosfs WARNS=6 clean

- sprinkle const
- add volatile qualifier to avoid vfork clobbering

Inspired by: NetBSD
PR: bin/139802
Reviewed by: ed

sbin/fsck: s/perror/perr/ to avoid shadowing

- rename some other vars too
- merge NetBSD license changes

Obtained from: NetBSD
PR: bin/139802
Reviewed by: ed

Make sure that each va_start has one and only one matching va_end,
especially in error cases.

Add missing static keywords for global variables to tools in sbin/.

These tools declare global variables without using the static keyword,
even though their use is limited to a single C-file, or without placing
an extern declaration of them in the proper header file.

Fix some style(9), although there's a lot more issues here.
Fix some casting errors.

PR: 142384
Submitted by: giffunip at tutopia dot com
Obtained from: NetBSD
MFC after: 3 weeks

mdoc: .Ud has attitude, it takes no argument!

Rename fields to match better the msdosfs headers. This work is still
incomplete as some info doesn't really belong to the structs where it is
defined.

Submitted by: Pedro F. Giffuni <giffunip tutopia com>
Reviewed by: bde
MFC after: 2 weeks

Bug fixes from NetBSD
- fix sign-compare issues.
- ANSIfy a couple of functions.
- Remove more duplicate #includes.
- Memory leak found by Coverity on NetBSD.

Submitted by: Pedro F. Giffuni <giffunip tutopia com>
Reviewed by: bde
MFC after: 2 weeks

License changes from NetBSD.
Move to 2 clause license, approved by Wolfgang Solfrank.

Submitted by: Pedro F. Giffuni <giffunip tutopia com>
MFC after: 2 weeks

fsck_msdosfs: accept no-op -C option for compatibilty with fsck

Submitted by: marck
Reviewed by: current@
Approved by: jhb (mentor)
MFC after: 1 week

Spot two more bugs WRT adherence to the local prompt style.

Use consistent style in user prompts: the question is in a new line
and begins with a capital letter. The rest of pwarn/ask pairs here
follows this style.

Requested by: bde

Prevent the `fix?' question from running together
with the problem description on the terminal: use
conventional punctuation.

Prefer the __printflike() macro to GCC's __attribute__ stuff.

Sync program's usage() with manpage's SYNOPSIS.

Sort sections.

Assorted markup, grammar, and spelling fixes.

Only compare the interesting part of the bootblock with its backup.
Allow check to proceed with bad backup boot block if we're doing a
readonly check. Various typos in comments.

Obtained from: NetBSD

style.Makefile(5):
Use WARNS?= instead of WARNS=.

Fixed operation of -f to match its documentation and fsck_ffs. It
has now has no effect except in combination with -p, and plain fsck
checks all file systems instead of skipping clean ones for msdosfs
only.

Renamed the force flag to skipclean and inverted its logic as in
fsck_ffs.

Fixed some bugs in checkdirty(). The check for the clean bit was
combined with the the signature check in a wrong way (basically
(dirty:= signature_recognised() && !clean) instead of
(mightbedirty:= !signature_recognized || !clean), so file systems
with unrecognized signatures were considered clean. Many of the
don't-care and reserved bits were not ignored, so some file systems
with valid signatures were unrecognized. One of my FAT32 file systems
has a signature of f8,ff,ff,ff,ff,ff,ff,f7 when dirty, but only
f8,ff,ff,0f,ff,ff,ff,07 was recognised as dirty for FAT32, so the
fail-unsafeness made my file system always considered clean.

Check the i/o non-error bit in checkdirty(). Its absence would give
an unrecognized signature in code that is unaware of it, but we now
mask it out of the signature so we have to check it explicitly. This
combines naturally with the check of the clean bit.

Reviewed by: rnordier (except for final details)

Document the dirty flag and other bits in the first 2 FAT entries
better. There is a related I/O error flag which we don't support in
the kernel but must support here. (Support for bits that we don't
understand here is mostly automatic by fail-safeness, but checkdirty()
has fail-unsafeness.) There are some reserved and don't-care bits
that weren't fully documented and aren't always masked properly. The
comment about the bits in readfat() will be removed when the masking
is fixed.

Submitted by: rnordier

Prepare to fix checkdirty() by moving it from check.c to fat.c. It is
identical to a subset of readfat(), so it belongs near readfat() if not
in it.

Oops, highly non-KNF indentation is normal for large expressions in
this program. Gnu indentation is used for these. Redo the fix for
the large expression at the end of the previous commit to give gnu
indentation. The original version was gnuish but had 9 bogus extra
characters of indentation in its continuation lines, perfect tab
lossage on every line, and other bugs.

The previous commit log should have claimed to fix style bugs in the
previous-1 commit (1.5), not the forced null previous commit (1.6).

Expanded the comment about the -F flag.

Fixed a nearby style bug (unreachable break).

fsck_msdosfs/main.c:
- Don't use errexit() to (mis)implement usage(). Using errexit() just
gave the bogus exit code 8.
- Fixed 3 other style bugs in usage().

fsck/fsutil.[ch]:
- Garbage-collected errexit(). It is essentially just one of NetBSD's
fsck_ext2fs error printing functions, but we don't have fsck_ext2fs
and the function is unsuitable for use there too (since pfatal() is
also used and it printf to a different stream).

Fixed style bugs in previous commit (unsorting of declarations and poor
wording in a comment).

Fixed quoting of `clean'.

Obtained from: fsck_ffs.8

Fixed some style bugs in previous commit (mainly highly non-KNF indentation).

Fixed style bugs in previous commit (unsorting of the global declarations
and addition of a tab to a blank line).

Make msdosfs support the dirty flag in FAT16 and FAT32.
Enable lockf support.

PR: 55861
Submitted by: Jun Su <junsu@m-net.arbornet.org> (original version)
Reviewed by: make universe

In check.c:
Avoid shadowing declarations.
Avoid compairing signed and unsigned types.

mount_msdos -> mount_msdosfs

Fix some 'SYNOPSIS' and 'usage' messages.

s/filesystem/file system/g as discussed on -developers

mdoc(7) police: Use the .Ud macro.

The .Nm utility

more file system > filesystem

Usage style sweep: spell "usage" with a small 'u'.
Also change one case of blatant __progname abuse (several more remain)
This commit does not touch anything in src/{contrib,crypto,gnu}/.

o __P removed
o ansi function prototypes
o unifdef -D__STDC__
o __dead2 on usage prototype
o remove now-bogus main prototype

Default to WARNS=2.
Binary builds that cannot handle this must explicitly set WARNS=0.

Reviewed by: mike

Document "-F".

Change exit return value to better match fsck_ffs(8).

Recognize the "-F" option which requests whether the filesystem needs to
be cleaned immediately in foreground, or if its cleaning can be deferred
to background.

Submitted by: Maxime Henrion <mux@qualys.com>

mdoc(7) police: fixed markup and program name.

Style tweaks.

Add fsck_msdosfs.

Obtained from: NetBSD