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Initial commit to git.

pull/1/head
Martin Pärtel 11 years ago
commit
2135ad723d
  1. 32
      .gitignore
  2. 340
      COPYING
  3. 135
      ChangeLog
  4. 6
      Makefile.am
  5. 41
      README
  6. 22
      TODO
  7. 57
      autogen.sh
  8. 42
      configure.ac
  9. 11
      src/Makefile.am
  10. 338
      src/bindfs.1
  11. 1329
      src/bindfs.c
  12. 33
      src/debug.h
  13. 83
      src/misc.c
  14. 40
      src/misc.h
  15. 325
      src/permchain.c
  16. 55
      src/permchain.h
  17. 177
      src/userinfo.c
  18. 39
      src/userinfo.h
  19. 2
      tests/Makefile.am
  20. 154
      tests/common.rb
  21. 206
      tests/test_bindfs.rb
  22. 45
      tests/test_concurrent.rb

32
.gitignore vendored

@ -0,0 +1,32 @@
# Autotools stuff
Makefile.in
Makefile
/autom4te.cache
/aclocal.m4
/compile
/configure
/depcomp
/install-sh
/missing
/config.log
/config.sub
/config.guess
/config.status
/config.h.in
/config.h
/libtool
/ltmain.sh
/stamp-h1
# C stuff
*.o
.libs
.deps
# Products
src/bindfs

340
COPYING

@ -0,0 +1,340 @@
GNU GENERAL PUBLIC LICENSE
Version 2, June 1991
Copyright (C) 1989, 1991 Free Software Foundation, Inc.
59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
Preamble
The licenses for most software are designed to take away your
freedom to share and change it. By contrast, the GNU General Public
License is intended to guarantee your freedom to share and change free
software--to make sure the software is free for all its users. This
General Public License applies to most of the Free Software
Foundation's software and to any other program whose authors commit to
using it. (Some other Free Software Foundation software is covered by
the GNU Library General Public License instead.) You can apply it to
your programs, too.
When we speak of free software, we are referring to freedom, not
price. Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
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To protect your rights, we need to make restrictions that forbid
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We protect your rights with two steps: (1) copyright the software, and
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Finally, any free program is threatened constantly by software
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The precise terms and conditions for copying, distribution and
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GNU GENERAL PUBLIC LICENSE
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
0. This License applies to any program or other work which contains
a notice placed by the copyright holder saying it may be distributed
under the terms of this General Public License. The "Program", below,
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either verbatim or with modifications and/or translated into another
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the term "modification".) Each licensee is addressed as "you".
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is covered only if its contents constitute a work based on the
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Whether that is true depends on what the Program does.
1. You may copy and distribute verbatim copies of the Program's
source code as you receive it, in any medium, provided that you
conspicuously and appropriately publish on each copy an appropriate
copyright notice and disclaimer of warranty; keep intact all the
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and give any other recipients of the Program a copy of this License
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You may charge a fee for the physical act of transferring a copy, and
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NO WARRANTY
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END OF TERMS AND CONDITIONS
How to Apply These Terms to Your New Programs
If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.
To do so, attach the following notices to the program. It is safest
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convey the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.
<one line to give the program's name and a brief idea of what it does.>
Copyright (C) <year> <name of author>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Also add information on how to contact you by electronic and paper mail.
If the program is interactive, make it output a short notice like this
when it starts in an interactive mode:
Gnomovision version 69, Copyright (C) year name of author
Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
This is free software, and you are welcome to redistribute it
under certain conditions; type `show c' for details.
The hypothetical commands `show w' and `show c' should show the appropriate
parts of the General Public License. Of course, the commands you use may
be called something other than `show w' and `show c'; they could even be
mouse-clicks or menu items--whatever suits your program.
You should also get your employer (if you work as a programmer) or your
school, if any, to sign a "copyright disclaimer" for the program, if
necessary. Here is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright interest in the program
`Gnomovision' (which makes passes at compilers) written by James Hacker.
<signature of Ty Coon>, 1 April 1989
Ty Coon, President of Vice
This General Public License does not permit incorporating your program into
proprietary programs. If your program is a subroutine library, you may
consider it more useful to permit linking proprietary applications with the
library. If this is what you want to do, use the GNU Library General
Public License instead of this License.

135
ChangeLog

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2010-08-07 Martin Pärtel <martin dot partel at gmail dot com>
* Improved --help and manpage.
* Disabled FUSE attribute cache when using mirroring to avoid
caching the owner of files when observed by a mirrored user.
* Added a testcase for the above.
* Released 1.9
2010-01-17 Martin Pärtel <martin dot partel at gmail dot com>
* Added options to control the behavior of chown and chgrp.
* Released 1.8.4
2009-03-28 Martin Pärtel <martin dot partel at gmail dot com>
* Added --ctime-from-mtime. Contributed by Shez.
* Added --chmod-allow-x.
* Released 1.8.3
2008-12-14 Martin Pärtel <martin dot partel at gmail dot com>
* Converted ChangeLog to UTF-8.
2008-12-13 Martin Pärtel <martin dot partel at gmail dot com>
* Specified that the license is GPL v2 or later in all source files
and in the README file.
* Released 1.8.2 with no functional changes.
2008-12-12 Martin Pärtel <martin dot partel at gmail dot com>
* Made xattr-rw the default instead of xattr-ro,
which returned a "permission denied" that could mislead some programs.
* Released 1.8.1
2008-08-17 Martin Pärtel <martin dot partel at gmail dot com>
* Fixed segfault in option parsing on platforms where
sizeof(int) != sizeof(long), such as amd64.
* Released 1.8
2008-07-08 Martin Pärtel <martin dot partel at gmail dot com>
* Symlinks to absolute paths didn't work. Now they do.
Reported by rpfuller. Thanks!
* Ownership of symlinks weren't set. Now they are.
Again, reported by rpfuller. Thanks again!
* Released 1.7
2008-06-26 Martin Pärtel <martin dot partel at gmail dot com>
* --create-as-* and --create-for-* weren't applied for mknod().
Bug report and patch by rpfuller. Thanks!
* Released 1.6.2
2008-06-25 Martin Pärtel <martin dot partel at gmail dot com>
* Added copyright messages to each source file.
* Escaped man-page dashes, since unescaped dashes are treated as
hyphens.
2008-06-19 Martin Pärtel <martin dot partel at gmail dot com>
* Fixed missing '=' signs in the man-page.
2008-05-14 Martin Pärtel <martin dot partel at gmail dot com>
* If the mount source and destination directories are the same
then we no longer require that the directory be empty.
(-ononempty is added implicitly)
* Released 1.6.1
2008-05-10 Martin Pärtel <martin dot partel at gmail dot com>
* Added --create-with-perms.
* Added a little automated test suite.
* Moved the project to code.google.com.
* Released 1.6
2008-01-26 Martin Pärtel <martin dot partel at gmail dot com>
* Fixed an embarrassing segfault while parsing --mirror arguments.
Thanks to Stefan Kost for reporting it!
* Released 1.5
2007-12-31 Martin Pärtel <martin dot partel at gmail dot com>
* Made compatible with Mac OS X with the help of Theocharis Athanasakis.
* Released 1.4.2
2007-11-09 Martin Pärtel <martin dot partel at gmail dot com>
* Fixed a bug in userinfo.c that could prevent using numeric
user or group IDs when /etc/passwd or /etc/group have long records.
* Released 1.4.1
2007-10-31 Martin Pärtel <martin dot partel at gmail dot com>
* Applied another patch from Joel Daniels to fix a bug that
occurred when /etc/passwd or /etc/group had long records.
Thanks!
* Released 1.4
2007-07-17 Martin Pärtel <martin dot partel at gmail dot com>
* Renamed the new options added by Joel
to --create-for-user and --create-for-group.
* Made it an error to use --create-as-user as non-root.
* Released 1.3
2007-07-17 Joel Daniels <jdaniel4 at uiuc dot e d u>
* Added the user_for_create and group_for_create options
2007-03-24 Martin Pärtel <martin dot partel at gmail dot com>
* Fixed minor errors in man-page.
* Released 1.2.1
2007-03-03 Martin Pärtel <martin dot partel at gmail dot com>
* Michael Roitzsch pointed out incorrect permission checks
for symlinks and fixed unlink() to correctly check for write permission
to the the directory (instead of the file). Thanks!
* Removed check_access() altogether. Will now rely on the kernel for
all permission checks by always enabling -o default_permissions.
* Released 1.2
2007-01-14 Martin Pärtel <martin dot partel at gmail dot com>
* Changed -o no_allow_others to -o no_allow_other.
* Added a way to specify group members in -m and -M.
* Released 1.1

6
Makefile.am

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# not a GNU package. You can remove this line, if
# have all needed files, that a GNU package needs
AUTOMAKE_OPTIONS = foreign
SUBDIRS = src tests

41
README

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bindfs - http://code.google.com/p/bindfs/
-- Overview --
bindfs is a FUSE filesystem for mirroring a directory to another
directory, similarly to mount --bind. The permissions of the mirrored
directory can be altered in various ways.
Some things bindfs can be used for:
- Making a directory read-only.
- Making all executables non-executable.
- Sharing a directory with a list of users (or groups).
- Modifying permission bits using rules with chmod-like syntax.
- Changing the permissions with which files are created.
Non-root users can use almost all features, but most interesting
use-cases need user_allow_other to be defined in /etc/fuse.conf
-- Installation --
Make sure fuse 2.5.3 or above is installed (http://fuse.sf.net/).
Then compile and install as usual:
./configure
make
make install
If you want the mounts made by non-root users to be visible to other users,
you may have to add the line user_allow_other to /etc/fuse.conf.
-- Usage --
See the bindfs --help or the man-page for instructions and examples.
-- License --
GNU General Public License version 2 or any later version.
See the file COPYING.

22
TODO

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Major (i.e. probably not very soon):
- Applying options to a subset of all files;
something like --if-file-matches '*.md5' { -u checksummer -p u+rw }
- This would make for some new useful options like --hide or --deny
- We could also have special xattrs like 'bindfs:perms' that
don't get propagated to the base directory but control bindfs behaviour
instead.
- All this leads to the thought of an integrated minilanguage.
Taken to the extreme, would this make bindfs almost yet another scripting
language binding for FUSE?
- Stackable/pluggable scripts? Any benefit over a remount?
Minor:
- Decide what to do with the fuse options uid=N and gid=N, or at least
mention them in the docs.
- Look at capabilities instead of uid==0 when checking for special privileges.
Do this in a portable way and fall back to uid==0 if not available.

57
autogen.sh

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#!/bin/bash
# Enable environment variables to override tool commands.
: ${AUTOCONF=autoconf}
: ${AUTOHEADER=autoheader}
: ${AUTOMAKE=automake}
: ${ACLOCAL=aclocal}
: ${LIBTOOLIZE=libtoolize}
# Apple calls the GNU libtoolize "glibtoolize"
if [[ ! -x `which "$LIBTOOLIZE"` ]]; then
LIBTOOLIZE=glibtoolize
fi
if [[ ! -x `which "$LIBTOOLIZE"` ]]; then
echo "Cannot find libtoolize"
exit 1
fi
# Add /usr/local/share/aclocal to aclocal's search path
if [[ -d /usr/local/share/aclocal ]]; then
ACLOCAL="$ACLOCAL -I /usr/local/share/aclocal"
fi
rm -rf autom4te.cache
rm -f aclocal.m4
rm -f missing mkinstalldirs depcomp install-sh libtool
echo "Running $ACLOCAL..."
$ACLOCAL || exit 1
echo "Running $AUTOHEADER..."
$AUTOHEADER || exit 1
echo "Running $AUTOCONF..."
$AUTOCONF || exit 1
echo "Running $LIBTOOLIZE..."
$LIBTOOLIZE --automake --copy --force || exit 1
echo "Running $AUTOMAKE..."
$AUTOMAKE -a -c || exit 1
if [ "$1" == "-d" ]; then
echo "Running configure --enable-debug"
echo
sleep 1s
./configure --enable-debug
elif [ -n "$1" ]; then
echo
echo "./configure $@"
./configure $@
else
echo
echo "autogen.sh completed successfully."
echo "Now run ./configure with the appropriate flags and then make."
fi

42
configure.ac

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AC_INIT([bindfs],[1.9],[martin.partel@gmail.com])
AM_INIT_AUTOMAKE
AM_CONFIG_HEADER(config.h)
AC_PROG_CC
AC_LANG(C)
AC_PROG_LIBTOOL
# --enable and --with options
AC_ARG_ENABLE([debug],
[AS_HELP_STRING([--enable-debug], [enable extra debug output])])
AC_ARG_WITH([core-foundation],
AS_HELP_STRING([--with-core-foundation], [link against Core Foundation (OS X only) @<:@default=no@:>@]))
if test x"$enable_debug" == "xyes" ; then
CFLAGS="${CFLAGS} -g -O0 -DMALLOC_CHECK_=2"
AC_DEFINE([BINDFS_DEBUG], [1], [Define to 1 to enable debugging messages])
else
CFLAGS="${CFLAGS} -O2"
fi
if test x"$with_core_foundation" == "xyes" ; then
AC_MSG_NOTICE([Linking with Core Foundation])
LDFLAGS="${LDFLAGS} -framework CoreFoundation"
fi
CFLAGS="${CFLAGS} -Wall -D_REENTRANT -D_FILE_OFFSET_BITS=64 -DFUSE_USE_VERSION=25"
# Check for xattrs
AC_CHECK_FUNCS([setxattr getxattr listxattr removexattr])
AC_CHECK_FUNCS([lsetxattr lgetxattr llistxattr lremovexattr])
# Check for fuse
PKG_CHECK_MODULES([fuse], [fuse >= 2.5.3])
AC_CONFIG_FILES([Makefile \
src/Makefile \
tests/Makefile])
AC_OUTPUT

11
src/Makefile.am

@ -0,0 +1,11 @@
## Process this file with automake to produce Makefile.in
bin_PROGRAMS = bindfs
noinst_HEADERS = debug.h permchain.h userinfo.h misc.h
bindfs_SOURCES = bindfs.c permchain.c userinfo.c misc.c
AM_CFLAGS = $(fuse_CFLAGS)
bindfs_LDADD = $(fuse_LIBS)
man_MANS = bindfs.1

338
src/bindfs.1

@ -0,0 +1,338 @@
.TH BINDFS 1
.SH NAME
bindfs \(hy mount \-\-bind in user\-space
.SH SYNOPSIS
\fBbindfs\fP [\fIoptions\fP]\fI dir mountpoint
.SH DESCRIPTION
A FUSE filesystem for mirroring the contents of a directory to another
directory. Additionally, one can change the permissions
of files in the mirrored directory.
.SH OPTIONS
.TP
.B \-h, \-\-help
Displays a help message and exits.
.TP
.B \-V, \-\-version
Displays version information and exits.
.TP
.B \-u, \-\-user, \-\-owner=\fIuser\fP, \-o owner=...
Makes all files owned by the specified user.
Also causes chown on the mounted filesystem to always fail.
.TP
.B \-g, \-\-group=\fIgroup\fP, \-o group=...
Makes all files owned by the specified group.
Also causes chgrp on the mounted filesystem to always fail.
.TP
.B \-p, \-\-perms=\fIpermissions\fP, \-o perms=...
Takes a comma\- or colon\-separated list of chmod\-like permission
specifications to be applied to the permission bits in order.
See \fB\%PERMISSION \%SPECIFICATION\fP below for details.
This only affects how the permission bits of existing files are altered
when shown in the mounted directory. You can use \-\-create\-with\-perms to
change the permissions that newly created files get in the source directory.
Note that, as usual, the root user isn't bound by the permissions set here.
You can get a truly read-only mount by using \fB-r\fP.
.TP
.B \-m, \-\-mirror=\fIusers\fP, \-o mirror=...
Takes a comma\- or colon\-separated list of users who will see themselves as
the owners of all files. Users who are not listed here will still be able
to access the mount if the permissions otherwise allow them to.
You can also give a group name prefixed with an '@' to mirror all members of
a group. This will not change which group the files are shown to have.
.TP
.B \-M, \-\-mirror\-only=\fIusers\fP, \-o mirror\-only=...
Like \fB\-\-mirror\fP but disallows access for all other users (except root).
.TP
.B \-n, \-\-no\-allow\-other, \-o no\-allow\-other
Does not add \fB\-o allow_other\fP to FUSE options.
This causes the mount to be accessible only by the current user.
.SH FILE CREATION POLICY
New files and directories are created so they are owned by the mounter.
bindfs can let this happen (the default for normal users),
or it can try to change the owner to the uid/gid of the process that
wants to create the file (the default for root). It is also possible to
have bindfs try to change the owner to a particular user or group.
.TP
.B \-\-create\-as\-user, \-o create\-as\-user
Tries to change the owner and group of new files and directories to the
uid and gid of the caller. This can work only if the mounter is root.
It is also the default behavior (mimicing mount \-\-bind) if the mounter is root.
.TP
.B \-\-create\-as\-mounter, \-o create\-as\-mounter
All new files and directories will be owned by the mounter.
This is the default behavior for non\-root mounters.
.TP
.B \-\-create\-for\-user=\fIuser\fP, \-o create\-for\-user=...
Tries to change the owner of new files and directories to the user
specified here. This can work only if the mounter is root. This
option overrides the \-\-create\-as\-user and \-\-create\-as\-mounter options.
.TP
.B \-\-create\-for\-group=\fIgroup\fP, \-o create\-for\-group=...
Tries to change the owning group of new files and directories to the
group specified here. This can work only if the mounter is root. This
option overrides the \-\-create\-as\-user and \-\-create\-as\-mounter options.
.TP
.B \-\-create\-with\-perms=\fIpermissions\fP, \-o create\-with\-perms=...
Works like \-\-perms but is applied to the permission bits of new files
get in the source directory.
Normally the permissions of new files depend on the creating process's
preferences and umask.
This option can be used to modify those permissions or override
them completely.
See \fB\%PERMISSION \%SPECIFICATION\fP below for details.
.SH CHOWN/CHGRP POLICY
The behaviour on chown/chgrp calls can be changed. By default they are passed
through to the source directory even if bindfs is set to show
a fake owner/group. A chown/chgrp call will only succeed if the user has
enough mirrored permissions to chmod the mirrored file AND
the mounter has enough permissions to chmod the real file.
.TP
.B \-\-chown\-normal, \-o chown\-normal
Tries to chown the underlying file. This is the default.
.TP
.B \-\-chown\-ignore, \-o chown\-ignore
Lets chown succeed (if the user has enough mirrored permissions)
but actually does nothing. A combined chown/chgrp is effectively turned
into a chgrp-only request.
.TP
.B \-\-chown\-deny, \-o chown\-deny
Makes chown always fail with a 'permission denied' error.
A combined chown/chgrp request will fail as well.
.TP
.B \-\-chgrp\-normal, \-o chgrp\-normal
Tries to chgrp the underlying file. This is the default.
.TP
.B \-\-chgrp\-ignore, \-o chgrp\-ignore
Lets chgrp succeed (if the user has enough mirrored permissions)
but actually does nothing. A combined chown/chgrp is effectively turned into a
chown-only request.
.TP
.B \-\-chgrp\-deny, \-o chgrp\-deny
Makes chgrp always fail with a 'permission denied' error.
A combined chown/chgrp request will fail as well.
.SH CHMOD POLICY
Chmod calls are forwarded to the source directory by default.
This may cause unexpected behaviour if bindfs is altering permission bits.
.TP
.B \-\-chmod\-normal, \-o chmod\-normal
Tries to chmod the underlying file. This will succeed if the user has
the appropriate mirrored permissions to chmod the mirrored file AND
the mounter has enough permissions to chmod the real file.
This is the default (in order to behave like mount \-\-bind by default).
.TP
.B \-\-chmod\-ignore, \-o chmod\-ignore
Lets chmod succeed (if the user has enough mirrored permissions)
but actually does nothing.
.TP
.B \-\-chmod\-deny, \-o chmod\-deny
Makes chmod always fail with a 'permission denied' error.
.TP
.B \-\-chmod\-allow\-x, \-o chmod\-allow\-x
Allows setting and clearing the executable attribute on files
(but not directories). When used with \-\-chmod\-ignore,
chmods will only affect execute bits on files and changes to other bits are
discarded.
With \-\-chmod\-deny, all chmods that would change any bits except
excecute bits on files will still fail with a 'permission denied'.
This option does nothing with \-\-chmod\-normal.
.SH XATTR POLICY
Extended attributes are mirrored by default,
though not all underlying file systems support xattrs.
.TP
.B \-\-xattr\-none, \-o xattr\-none
Disable extended attributes altogether. All operations will
return 'Operation not supported'.
.TP
.B \-\-xattr\-ro, \-o xattr\-ro
Let extended attributes be read\-only.
.TP
.B \-\-xattr\-rw, \-o xattr\-rw
Let extended attributes be read\-write (the default).
The read/write permissions are checked against the (possibly modified)
file permissions inside the mount.
.SH TIME-RELATED OPTIONS
Recall that a unix file has three standard timestamps:
\fBatime\fP (last access i.e. read time),
\fBmtime\fP (last content modification time)
\fBctime\fP (last content or metadata (inode) change time)
It may sometimes be useful to alter these timestamps, but care should be taken
not to cause programs (e.g. backup jobs) to miss important changes.
.TP
.B \-\-ctime\-from-mtime, \-o ctime\-from\-mtime
Reads the ctime of each file and directory from its mtime.
In other words, only content modifications (as opposed to metadata changes)
will be reflected in a mirrored file's ctime.
(The underlying file's ctime will still be updated normally.)
.SH FUSE OPTIONS
.TP
.B \-o \fIoptions
Fuse options.
.TP
.B \-r, \-o ro
Make the mount strictly read-only.
This even prevents root from writing to it.
If this is all you need, then (since Linux 2.6.26) you can get a
more efficent mount with \fBmount \-\-bind\fP and then \fBmount \-o remount,ro\fP.
.TP
.B \-d, \-o debug
Enable debug output (implies \-f).
.TP
.B \-f
Foreground operation.
.TP
.B \-s
Disable multithreaded operation. bindfs should be thread-safe.
.SH PERMISSION SPECIFICATION
The \fB\-p\fP option takes a comma\- or colon\-separated list of either octal
numeric permission bits or symbolic representations of permission bit
operations.
The symbolic representation is based on that of the \fBchmod\fP(1) command.
setuid, setgid and sticky bits are ignored.
This program extends the chmod symbolic representation with the following
operands:
`\fBD\fP' (right hand side)
Works like \fBX\fP but applies only to directories (not to executables).
`\fBd\fP' and `\fBf\fP' (left hand side)
Makes this directive only apply to directories (d) or files (f).
e.g. \fBgd\-w\fP would remove the group write bit from all directories.
`\fBu\fP', `\fBg\fP', `\fBo\fP' (right hand side)
Uses the user (u), group (g) or others (o) permission bits of
the original file.
e.g. \fBg=u\fP would copy the user's permission bits to the group.
\fBug+o\fP would add the others' permissions to the owner and group.
.I Examples
.TP
.B o\-rwx
Removes all permission bits from others.
.TP
.B g=rD
Allows group to read all files and enter all directories, but nothing else.
.TP
.B 0644,a+X
Sets permission bits to 0644 and adds the execute bit for everyone
to all directories and executables.
.TP
.B og\-x:og+rD:u=rwX:g+rw
Removes execute bit for others and group,
adds read and directory execute for others and group,
sets user permissions to read, write and execute directory/executable,
adds read and write for group.
.SH EXAMPLES
.BR
.TP
.B bindfs \-u www \-g nogroup \-p 0000,u=rD ~/mywebsite ~/public_html/mysite
Publishes a website in public_html so that only the 'www' user can
read the site.
.TP
.B bindfs \-M foo,bar,1007,@mygroup \-p 0600,u+X dir mnt
Gives access to 'foo', 'bar', the user with the UID 1007 as well as
everyone in the group 'mygroup'. Sets the permission bits to 0600,
thus giving the specified users read/write access,
and adds the user execute bit for directories and executables.
.TP
.B bindfs \-ono\-allow\-other,perms=a\-w somedir somedir
Makes a directory read\-only and accessable only by the current user.
.TP
.B bindfs#/home/bob/shared /var/www/shared/bob fuse perms=0000:u+rD 0 0
An example \fI/etc/fstab\fP entry. Note that the colon must be used to
separate arguments to perms, because the comma is an option separator in
\fI/etc/fstab\fP.
.SH NOTES
Setuid and setgid bits have no effect inside the mount.
This is a necessary security feature of FUSE.
MacFuse caches file contents by default.
This means that changes in source files are not always immediately visible under the mount point.
\fB\-o nolocalcaches\fP can be used to disable the cache.
.SH BUGS
Please report to the issue tracker on the project home page at
http://code.google.com/p/bindfs/
.SH AUTHOR
Martin P\[:a]rtel <martin dot partel at gmail dot com>
.SH SEE ALSO
\fBchmod\fP(1), \fBfusermount\fP(1)

1329
src/bindfs.c

@ -0,0 +1,1329 @@
/*
Copyright 2006,2007,2008,2009,2010 Martin Pärtel <martin.partel@gmail.com>
This file is part of bindfs.
bindfs is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
bindfs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with bindfs. If not, see <http://www.gnu.org/licenses/>.
This file is based on fusexmp_fh.c from FUSE 2.5.3,
which had the following notice:
---
FUSE: Filesystem in Userspace
Copyright (C) 2001-2006 Miklos Szeredi <miklos@szeredi.hu>
This program can be distributed under the terms of the GNU GPL.
See the file COPYING.
---
*/
#include <config.h>
/* For pread/pwrite */
#define _XOPEN_SOURCE 500
#include <stdlib.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#include <sys/statvfs.h>
#include <unistd.h>
#include <fcntl.h>
#include <dirent.h>
#include <errno.h>
#include <getopt.h>
#include <assert.h>
#include <pwd.h>
#include <grp.h>
#ifdef HAVE_SETXATTR
#include <sys/xattr.h>
#endif
#include <fuse.h>
#include <fuse_opt.h>
#include "debug.h"
#include "permchain.h"
#include "userinfo.h"
#include "misc.h"
/* SETTINGS */
static struct settings {
const char *progname;
struct permchain *permchain; /* permission bit rules. see permchain.h */
uid_t new_uid; /* user-specified uid */
gid_t new_gid; /* user-specified gid */
uid_t create_for_uid;
gid_t create_for_gid;
const char *mntsrc;
const char *mntdest;
int mntsrc_fd;
enum CreatePolicy {
CREATE_AS_USER,
CREATE_AS_MOUNTER
} create_policy;
struct permchain *create_permchain; /* the --create-with-perms option */
enum ChownPolicy {
CHOWN_NORMAL,
CHOWN_IGNORE,
CHOWN_DENY
} chown_policy;
enum ChgrpPolicy {
CHGRP_NORMAL,
CHGRP_IGNORE,
CHGRP_DENY
} chgrp_policy;
enum ChmodPolicy {
CHMOD_NORMAL,
CHMOD_IGNORE,
CHMOD_DENY
} chmod_policy;
int chmod_allow_x;
enum XAttrPolicy {
XATTR_UNIMPLEMENTED,
XATTR_READ_ONLY,
XATTR_READ_WRITE
} xattr_policy;
int mirrored_users_only;
uid_t* mirrored_users;
int num_mirrored_users;
gid_t *mirrored_members;
int num_mirrored_members;
int ctime_from_mtime;
} settings;
/* PROTOTYPES */
static int is_mirroring_enabled();
/* Checks whether the uid is to be the mirrored owner of all files. */
static int is_mirrored_user(uid_t uid);
/* Processes the virtual path to a real path. Don't free() the result. */
static const char *process_path(const char *path);
/* The common parts of getattr and fgetattr */
static int getattr_common(const char *path, struct stat *stbuf);
/* FUSE callbacks */
static void *bindfs_init();
static void bindfs_destroy(void *private_data);
static int bindfs_getattr(const char *path, struct stat *stbuf);
static int bindfs_fgetattr(const char *path, struct stat *stbuf,
struct fuse_file_info *fi);
static int bindfs_readlink(const char *path, char *buf, size_t size);
static int bindfs_opendir(const char *path, struct fuse_file_info *fi);
static inline DIR *get_dirp(struct fuse_file_info *fi);
static int bindfs_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
off_t offset, struct fuse_file_info *fi);
static int bindfs_releasedir(const char *path, struct fuse_file_info *fi);
static int bindfs_mknod(const char *path, mode_t mode, dev_t rdev);
static int bindfs_mkdir(const char *path, mode_t mode);
static int bindfs_unlink(const char *path);
static int bindfs_rmdir(const char *path);
static int bindfs_symlink(const char *from, const char *to);
static int bindfs_rename(const char *from, const char *to);
static int bindfs_link(const char *from, const char *to);
static int bindfs_chmod(const char *path, mode_t mode);
static int bindfs_chown(const char *path, uid_t uid, gid_t gid);
static int bindfs_truncate(const char *path, off_t size);
static int bindfs_ftruncate(const char *path, off_t size,
struct fuse_file_info *fi);
static int bindfs_utime(const char *path, struct utimbuf *buf);
static int bindfs_create(const char *path, mode_t mode, struct fuse_file_info *fi);
static int bindfs_open(const char *path, struct fuse_file_info *fi);
static int bindfs_read(const char *path, char *buf, size_t size, off_t offset,
struct fuse_file_info *fi);
static int bindfs_write(const char *path, const char *buf, size_t size,
off_t offset, struct fuse_file_info *fi);
static int bindfs_statfs(const char *path, struct statvfs *stbuf);
static int bindfs_release(const char *path, struct fuse_file_info *fi);
static int bindfs_fsync(const char *path, int isdatasync,
struct fuse_file_info *fi);
static void print_usage(const char *progname);
static void atexit_func();
static int process_option(void *data, const char *arg, int key,
struct fuse_args *outargs);
static int is_mirroring_enabled()
{
return settings.num_mirrored_users + settings.num_mirrored_members > 0;
}
static int is_mirrored_user(uid_t uid)
{
int i;
for (i = 0; i < settings.num_mirrored_users; ++i) {
if (settings.mirrored_users[i] == uid)
break;
}
if (i < settings.num_mirrored_users) { /* found in mirrored_users */
return 1;
} else {
for (i = 0; i < settings.num_mirrored_members; ++i) {
if (user_belongs_to_group(uid, settings.mirrored_members[i]))
break;
}
if (i < settings.num_mirrored_members) /* found in mirrored_members */
return 1;
}
return 0;
}
static const char *process_path(const char *path)
{
if (path == NULL) /* possible? */
return NULL;
while (*path == '/')
++path;
if (*path == '\0')
return ".";
else
return path;
}
static int getattr_common(const char *procpath, struct stat *stbuf)
{
struct fuse_context *fc = fuse_get_context();
/* Copy mtime (file content modification time)
to ctime (inode/status change time)
if the user asked for that */
if (settings.ctime_from_mtime)
stbuf->st_ctime = stbuf->st_mtime;
/* Report user-defined owner/group if specified */
if (settings.new_uid != -1)
stbuf->st_uid = settings.new_uid;
if (settings.new_gid != -1)
stbuf->st_gid = settings.new_gid;
/* Mirrored user? */
if (is_mirroring_enabled() && is_mirrored_user(fc->uid)) {
stbuf->st_uid = fc->uid;
} else if (settings.mirrored_users_only && fc->uid != 0) {
stbuf->st_mode &= ~0777; /* Deny all access if mirror-only and not root */
return 0;
}
if ((stbuf->st_mode & S_IFLNK) == S_IFLNK)
return 0; /* don't bother with symlink permissions -- they don't matter */
/* Apply user-defined permission bit modifications */
stbuf->st_mode = permchain_apply(settings.permchain, stbuf->st_mode);
/* Check that we can really do what we promise */
if (access(procpath, R_OK) == -1)
stbuf->st_mode &= ~0444;
if (access(procpath, W_OK) == -1)
stbuf->st_mode &= ~0222;
if (access(procpath, X_OK) == -1)
stbuf->st_mode &= ~0111;
return 0;
}
static void *bindfs_init()
{
assert(settings.permchain != NULL);
assert(settings.mntsrc_fd > 0);
if (fchdir(settings.mntsrc_fd) != 0) {
fprintf(
stderr,
"Could not change working directory to '%s': %s\n",
settings.mntsrc,
strerror(errno)
);
fuse_exit(fuse_get_context()->fuse);
}
return NULL;
}
static void bindfs_destroy(void *private_data)
{
}
static int bindfs_getattr(const char *path, struct stat *stbuf)
{
path = process_path(path);
if (lstat(path, stbuf) == -1)
return -errno;
return getattr_common(path, stbuf);
}
static int bindfs_fgetattr(const char *path, struct stat *stbuf,
struct fuse_file_info *fi)
{
path = process_path(path);
if (fstat(fi->fh, stbuf) == -1)
return -errno;
return getattr_common(path, stbuf);
}
static int bindfs_readlink(const char *path, char *buf, size_t size)
{
int res;
path = process_path(path);
/* No need to check for access to the link itself, since symlink
permissions don't matter. Access to the path components of the symlink
are automatically queried by FUSE. */
res = readlink(path, buf, size - 1);
if (res == -1)
return -errno;
buf[res] = '\0';
return 0;
}
static int bindfs_opendir(const char *path, struct fuse_file_info *fi)
{
DIR *dp;
path = process_path(path);
dp = opendir(path);
if (dp == NULL)
return -errno;
fi->fh = (unsigned long) dp;
return 0;
}
static inline DIR *get_dirp(struct fuse_file_info *fi)
{
return (DIR *) (uintptr_t) fi->fh;
}
static int bindfs_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
off_t offset, struct fuse_file_info *fi)
{
DIR *dp = get_dirp(fi);
struct dirent *de;
(void) path;
seekdir(dp, offset);
while ((de = readdir(dp)) != NULL) {
struct stat st;
memset(&st, 0, sizeof(st));
st.st_ino = de->d_ino;
st.st_mode = de->d_type << 12;
if (filler(buf, de->d_name, &st, telldir(dp)))
break;
}
return 0;
}
static int bindfs_releasedir(const char *path, struct fuse_file_info *fi)
{
DIR *dp = get_dirp(fi);
(void) path;
closedir(dp);
return 0;
}
static int bindfs_mknod(const char *path, mode_t mode, dev_t rdev)
{
int res;
struct fuse_context *fc;
uid_t file_owner = -1;
gid_t file_group = -1;
path = process_path(path);
mode = permchain_apply(settings.create_permchain, mode);
if (S_ISFIFO(mode))
res = mkfifo(path, mode);
else
res = mknod(path, mode, rdev);
if (res == -1)
return -errno;
if (settings.create_policy == CREATE_AS_USER) {
fc = fuse_get_context();
file_owner = fc->uid;
file_group = fc->gid;
}
if (settings.create_for_uid != -1)
file_owner = settings.create_for_uid;
if (settings.create_for_gid != -1)
file_group = settings.create_for_gid;
if ((file_owner != -1) || (file_group != -1)) {
if (chown(path, file_owner, file_group) == -1) {
DPRINTF("Failed to chown new device node (%d)", errno);
}
}
return 0;
}
static int bindfs_mkdir(const char *path, mode_t mode)
{
int res;
struct fuse_context *fc;
uid_t file_owner = -1;
gid_t file_group = -1;
path = process_path(path);
mode |= S_IFDIR; /* tell permchain_apply this is a directory */
mode = permchain_apply(settings.create_permchain, mode);
res = mkdir(path, mode & 0777);
if (res == -1)
return -errno;
if (settings.create_policy == CREATE_AS_USER) {
fc = fuse_get_context();
file_owner = fc->uid;
file_group = fc->gid;
}
if (settings.create_for_uid != -1)
file_owner = settings.create_for_uid;
if (settings.create_for_gid != -1)
file_group = settings.create_for_gid;
if ((file_owner != -1) || (file_group != -1)) {
if (chown(path, file_owner, file_group) == -1) {
DPRINTF("Failed to chown new directory (%d)", errno);
}
}
return 0;
}
static int bindfs_unlink(const char *path)
{
int res;
path = process_path(path);
res = unlink(path);
if (res == -1)
return -errno;
return 0;
}
static int bindfs_rmdir(const char *path)
{
int res;
path = process_path(path);
res = rmdir(path);
if (res == -1)
return -errno;
return 0;
}
static int bindfs_symlink(const char *from, const char *to)
{
int res;
struct fuse_context *fc;
uid_t file_owner = -1;
gid_t file_group = -1;
to = process_path(to);
res = symlink(from, to);
if (res == -1)
return -errno;
if (settings.create_policy == CREATE_AS_USER) {
fc = fuse_get_context();
file_owner = fc->uid;
file_group = fc->gid;
}
if (settings.create_for_uid != -1)
file_owner = settings.create_for_uid;
if (settings.create_for_gid != -1)
file_group = settings.create_for_gid;
if ((file_owner != -1) || (file_group != -1)) {
if (lchown(to, file_owner, file_group) == -1) {
DPRINTF("Failed to lchown new symlink (%d)", errno);
}
}
return 0;
}
static int bindfs_rename(const char *from, const char *to)
{
int res;
from = process_path(from);
to = process_path(to);
res = rename(from, to);
if (res == -1)
return -errno;
return 0;
}
static int bindfs_link(const char *from, const char *to)
{
int res;
from = process_path(from);
to = process_path(to);
res = link(from, to);
if (res == -1)
return -errno;
return 0;
}
static int bindfs_chmod(const char *path,