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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-15 19:37:10 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-15 19:37:10 +0000
commitc9addba5cc770d2d231b34f6739f32c6be8690f1 (patch)
treec643da154a95a1d163137135050bb47858a1654e /gl/lib/chown.c
parentInitial commit. (diff)
downloadman-db-c9addba5cc770d2d231b34f6739f32c6be8690f1.tar.xz
man-db-c9addba5cc770d2d231b34f6739f32c6be8690f1.zip
Adding upstream version 2.12.0.upstream/2.12.0
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'gl/lib/chown.c')
-rw-r--r--gl/lib/chown.c150
1 files changed, 150 insertions, 0 deletions
diff --git a/gl/lib/chown.c b/gl/lib/chown.c
new file mode 100644
index 0000000..d735818
--- /dev/null
+++ b/gl/lib/chown.c
@@ -0,0 +1,150 @@
+/* provide consistent interface to chown for systems that don't interpret
+ an ID of -1 as meaning "don't change the corresponding ID".
+
+ Copyright (C) 1997, 2004-2007, 2009-2023 Free Software Foundation, Inc.
+
+ This file is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
+
+ This file 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 Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+/* written by Jim Meyering */
+
+#include <config.h>
+
+/* Specification. */
+#include <unistd.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/stat.h>
+
+#if !HAVE_CHOWN
+
+/* Simple stub that always fails with ENOSYS, for mingw. */
+int
+chown (_GL_UNUSED const char *file, _GL_UNUSED uid_t uid,
+ _GL_UNUSED gid_t gid)
+{
+ errno = ENOSYS;
+ return -1;
+}
+
+#else /* HAVE_CHOWN */
+
+/* Below we refer to the system's chown(). */
+# undef chown
+
+/* Provide a more-closely POSIX-conforming version of chown on
+ systems with one or both of the following problems:
+ - chown doesn't treat an ID of -1 as meaning
+ "don't change the corresponding ID".
+ - chown doesn't dereference symlinks. */
+
+int
+rpl_chown (const char *file, uid_t uid, gid_t gid)
+{
+ struct stat st;
+ bool stat_valid = false;
+ int result;
+
+# if CHOWN_CHANGE_TIME_BUG
+ if (gid != (gid_t) -1 || uid != (uid_t) -1)
+ {
+ if (stat (file, &st))
+ return -1;
+ stat_valid = true;
+ }
+# endif
+
+# if CHOWN_FAILS_TO_HONOR_ID_OF_NEGATIVE_ONE
+ if (gid == (gid_t) -1 || uid == (uid_t) -1)
+ {
+ /* Stat file to get id(s) that should remain unchanged. */
+ if (!stat_valid && stat (file, &st))
+ return -1;
+ if (gid == (gid_t) -1)
+ gid = st.st_gid;
+ if (uid == (uid_t) -1)
+ uid = st.st_uid;
+ }
+# endif
+
+# if CHOWN_MODIFIES_SYMLINK
+ {
+ /* Handle the case in which the system-supplied chown function
+ does *not* follow symlinks. Instead, it changes permissions
+ on the symlink itself. To work around that, we open the
+ file (but this can fail due to lack of read or write permission) and
+ use fchown on the resulting descriptor. */
+ int open_flags = O_NONBLOCK | O_NOCTTY | O_CLOEXEC;
+ int fd = open (file, O_RDONLY | open_flags);
+ if (0 <= fd
+ || (errno == EACCES
+ && 0 <= (fd = open (file, O_WRONLY | open_flags))))
+ {
+ int saved_errno;
+ bool fchown_socket_failure;
+
+ result = fchown (fd, uid, gid);
+ saved_errno = errno;
+
+ /* POSIX says fchown can fail with errno == EINVAL on sockets
+ and pipes, so fall back on chown in that case. */
+ fchown_socket_failure =
+ (result != 0 && saved_errno == EINVAL
+ && fstat (fd, &st) == 0
+ && (S_ISFIFO (st.st_mode) || S_ISSOCK (st.st_mode)));
+
+ close (fd);
+
+ if (! fchown_socket_failure)
+ {
+ errno = saved_errno;
+ return result;
+ }
+ }
+ else if (errno != EACCES)
+ return -1;
+ }
+# endif
+
+# if CHOWN_TRAILING_SLASH_BUG
+ if (!stat_valid)
+ {
+ size_t len = strlen (file);
+ if (len && file[len - 1] == '/' && stat (file, &st))
+ return -1;
+ }
+# endif
+
+ result = chown (file, uid, gid);
+
+# if CHOWN_CHANGE_TIME_BUG
+ if (result == 0 && stat_valid
+ && (uid == st.st_uid || uid == (uid_t) -1)
+ && (gid == st.st_gid || gid == (gid_t) -1))
+ {
+ /* No change in ownership, but at least one argument was not -1,
+ so we are required to update ctime. Since chown succeeded,
+ we assume that chmod will do likewise. Fortunately, on all
+ known systems where a 'no-op' chown skips the ctime update, a
+ 'no-op' chmod still does the trick. */
+ result = chmod (file, st.st_mode & (S_IRWXU | S_IRWXG | S_IRWXO
+ | S_ISUID | S_ISGID | S_ISVTX));
+ }
+# endif
+
+ return result;
+}
+
+#endif /* HAVE_CHOWN */