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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:11:47 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:11:47 +0000 |
commit | 758f820bcc0f68aeebac1717e537ca13a320b909 (patch) | |
tree | 48111ece75cf4f98316848b37a7e26356e00669e /lib/dirchownmod.c | |
parent | Initial commit. (diff) | |
download | coreutils-758f820bcc0f68aeebac1717e537ca13a320b909.tar.xz coreutils-758f820bcc0f68aeebac1717e537ca13a320b909.zip |
Adding upstream version 9.1.upstream/9.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/dirchownmod.c')
-rw-r--r-- | lib/dirchownmod.c | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/lib/dirchownmod.c b/lib/dirchownmod.c new file mode 100644 index 0000000..2bc7076 --- /dev/null +++ b/lib/dirchownmod.c @@ -0,0 +1,141 @@ +/* Change the ownership and mode bits of a directory. + + Copyright (C) 2006-2022 Free Software Foundation, Inc. + + 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 3 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, see <https://www.gnu.org/licenses/>. */ + +/* Written by Paul Eggert. */ + +#include <config.h> + +#include "dirchownmod.h" + +#include <errno.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <unistd.h> + +#include "stat-macros.h" + +#ifndef HAVE_FCHMOD +# define HAVE_FCHMOD 0 +# undef fchmod +# define fchmod(fd, mode) (-1) +#endif + +/* Change the ownership and mode bits of a directory. If FD is + nonnegative, it should be a file descriptor associated with the + directory; close it before returning. DIR is the name of the + directory. + + If MKDIR_MODE is not (mode_t) -1, mkdir (DIR, MKDIR_MODE) has just + been executed successfully with umask zero, so DIR should be a + directory (not a symbolic link). + + First, set the file's owner to OWNER and group to GROUP, but leave + the owner alone if OWNER is (uid_t) -1, and similarly for GROUP. + + Then, set the file's mode bits to MODE, except preserve any of the + bits that correspond to zero bits in MODE_BITS. In other words, + MODE_BITS is a mask that specifies which of the file's mode bits + should be set or cleared. MODE should be a subset of MODE_BITS, + which in turn should be a subset of CHMOD_MODE_BITS. + + This implementation assumes the current umask is zero. + + Return 0 if successful, -1 (setting errno) otherwise. Unsuccessful + calls may do the chown but not the chmod. */ + +int +dirchownmod (int fd, char const *dir, mode_t mkdir_mode, + uid_t owner, gid_t group, + mode_t mode, mode_t mode_bits) +{ + struct stat st; + int result = (fd < 0 ? stat (dir, &st) : fstat (fd, &st)); + + if (result == 0) + { + mode_t dir_mode = st.st_mode; + + /* Check whether DIR is a directory. If FD is nonnegative, this + check avoids changing the ownership and mode bits of the + wrong file in many cases. This doesn't fix all the race + conditions, but it is better than nothing. */ + if (! S_ISDIR (dir_mode)) + { + errno = ENOTDIR; + result = -1; + } + else + { + /* If at least one of the S_IXUGO bits are set, chown might + clear the S_ISUID and S_SGID bits. Keep track of any + file mode bits whose values are indeterminate due to this + issue. */ + mode_t indeterminate = 0; + + /* On some systems, chown clears S_ISUID and S_ISGID, so do + chown before chmod. On older System V hosts, ordinary + users can give their files away via chown; don't worry + about that here, since users shouldn't do that. */ + + if ((owner != (uid_t) -1 && owner != st.st_uid) + || (group != (gid_t) -1 && group != st.st_gid)) + { + result = (0 <= fd + ? fchown (fd, owner, group) + : mkdir_mode != (mode_t) -1 + ? lchown (dir, owner, group) + : chown (dir, owner, group)); + + /* Either the user cares about an indeterminate bit and + it'll be set properly by chmod below, or the user + doesn't care and it's OK to use the bit's pre-chown + value. So there's no need to re-stat DIR here. */ + + if (result == 0 && (dir_mode & S_IXUGO)) + indeterminate = dir_mode & (S_ISUID | S_ISGID); + } + + /* If the file mode bits might not be right, use chmod to + change them. Don't change bits the user doesn't care + about. */ + if (result == 0 && (((dir_mode ^ mode) | indeterminate) & mode_bits)) + { + mode_t chmod_mode = + mode | (dir_mode & CHMOD_MODE_BITS & ~mode_bits); + result = (HAVE_FCHMOD && 0 <= fd + ? fchmod (fd, chmod_mode) + : mkdir_mode != (mode_t) -1 + ? lchmod (dir, chmod_mode) + : chmod (dir, chmod_mode)); + } + } + } + + if (0 <= fd) + { + if (result == 0) + result = close (fd); + else + { + int e = errno; + close (fd); + errno = e; + } + } + + return result; +} |