diff options
Diffstat (limited to 'lib/fchownat.c')
| -rw-r--r-- | lib/fchownat.c | 108 |
1 files changed, 86 insertions, 22 deletions
diff --git a/lib/fchownat.c b/lib/fchownat.c index 801c92a..7f1c160 100644 --- a/lib/fchownat.c +++ b/lib/fchownat.c @@ -4,12 +4,12 @@ when the buggy fchownat-with-AT_SYMLINK_NOFOLLOW operates on a symlink, it mistakenly affects the symlink referent, rather than the symlink itself. - Copyright (C) 2006-2007 Free Software Foundation, Inc. + Copyright (C) 2006-2007, 2009-2016 Free Software Foundation, Inc. - This program is free software; you can redistribute it and/or modify + 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, or (at your option) - any later version. + 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 @@ -17,34 +17,98 @@ 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + along with this program. If not, see <http://www.gnu.org/licenses/>. */ /* written by Jim Meyering */ #include <config.h> -#include "openat.h" - #include <unistd.h> -#include "dirname.h" /* solely for definition of IS_ABSOLUTE_FILE_NAME */ -#include "lchown.h" -#include "save-cwd.h" -#include "openat-priv.h" +#include <errno.h> +#include <string.h> + +#include "openat.h" + +#if !HAVE_FCHOWNAT /* Replacement for Solaris' function by the same name. Invoke chown or lchown on file, FILE, using OWNER and GROUP, in the directory open on descriptor FD. If FLAG is AT_SYMLINK_NOFOLLOW, then use lchown, otherwise, use chown. If possible, do it without changing the working directory. Otherwise, resort to using save_cwd/fchdir, - then mkdir/restore_cwd. If either the save_cwd or the restore_cwd - fails, then give a diagnostic and exit nonzero. */ - -#define AT_FUNC_NAME fchownat -#define AT_FUNC_F1 lchown -#define AT_FUNC_F2 chown -#define AT_FUNC_USE_F1_COND flag == AT_SYMLINK_NOFOLLOW -#define AT_FUNC_POST_FILE_PARAM_DECLS , uid_t owner, gid_t group, int flag -#define AT_FUNC_POST_FILE_ARGS , owner, group -#include "at-func.c" + then (chown|lchown)/restore_cwd. If either the save_cwd or the + restore_cwd fails, then give a diagnostic and exit nonzero. */ + +# define AT_FUNC_NAME fchownat +# define AT_FUNC_F1 lchown +# define AT_FUNC_F2 chown +# define AT_FUNC_USE_F1_COND AT_SYMLINK_NOFOLLOW +# define AT_FUNC_POST_FILE_PARAM_DECLS , uid_t owner, gid_t group, int flag +# define AT_FUNC_POST_FILE_ARGS , owner, group +# include "at-func.c" +# undef AT_FUNC_NAME +# undef AT_FUNC_F1 +# undef AT_FUNC_F2 +# undef AT_FUNC_USE_F1_COND +# undef AT_FUNC_POST_FILE_PARAM_DECLS +# undef AT_FUNC_POST_FILE_ARGS + +#else /* HAVE_FCHOWNAT */ + +# undef fchownat + +# if FCHOWNAT_NOFOLLOW_BUG + +/* Failure to handle AT_SYMLINK_NOFOLLOW requires the /proc/self/fd or + fchdir workaround to call lchown for lchownat, but there is no need + to penalize chownat. */ +static int +local_lchownat (int fd, char const *file, uid_t owner, gid_t group); + +# define AT_FUNC_NAME local_lchownat +# define AT_FUNC_F1 lchown +# define AT_FUNC_POST_FILE_PARAM_DECLS , uid_t owner, gid_t group +# define AT_FUNC_POST_FILE_ARGS , owner, group +# include "at-func.c" +# undef AT_FUNC_NAME +# undef AT_FUNC_F1 +# undef AT_FUNC_POST_FILE_PARAM_DECLS +# undef AT_FUNC_POST_FILE_ARGS + +# endif + +/* Work around bugs with trailing slash, using the same workarounds as + chown and lchown. */ + +int +rpl_fchownat (int fd, char const *file, uid_t owner, gid_t group, int flag) +{ +# if FCHOWNAT_NOFOLLOW_BUG + if (flag == AT_SYMLINK_NOFOLLOW) + return local_lchownat (fd, file, owner, group); +# endif +# if FCHOWNAT_EMPTY_FILENAME_BUG + if (file[0] == '\0') + { + errno = ENOENT; + return -1; + } +# endif +# if CHOWN_TRAILING_SLASH_BUG + { + size_t len = strlen (file); + struct stat st; + if (len && file[len - 1] == '/') + { + if (statat (fd, file, &st)) + return -1; + if (flag == AT_SYMLINK_NOFOLLOW) + return fchownat (fd, file, owner, group, 0); + } + } +# endif + return fchownat (fd, file, owner, group, flag); +} + +#endif /* HAVE_FCHOWNAT */ |