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author | Lorry Tar Creator <lorry-tar-importer@lorry> | 2016-01-20 10:55:18 +0000 |
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committer | Lorry Tar Creator <lorry-tar-importer@lorry> | 2016-01-20 10:55:18 +0000 |
commit | 70e9163c9c18e995515598085cb824e554eb7ae7 (patch) | |
tree | a42dc8b2a6c031354bf31472de888bfc8a060132 /lib/at-func.c | |
parent | cbf5993c43f49281173f185863577d86bfac6eae (diff) | |
download | coreutils-tarball-70e9163c9c18e995515598085cb824e554eb7ae7.tar.gz |
coreutils-8.25HEADcoreutils-8.25master
Diffstat (limited to 'lib/at-func.c')
-rw-r--r-- | lib/at-func.c | 130 |
1 files changed, 95 insertions, 35 deletions
diff --git a/lib/at-func.c b/lib/at-func.c index f98c207..5a8894a 100644 --- a/lib/at-func.c +++ b/lib/at-func.c @@ -1,10 +1,10 @@ -/* Define an at-style functions like fstatat, unlinkat, fchownat, etc. - Copyright (C) 2006 Free Software Foundation, Inc. +/* Define at-style functions like fstatat, unlinkat, fchownat, etc. + Copyright (C) 2006, 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 @@ -12,67 +12,123 @@ 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 */ -#define CALL_FUNC(F) \ - (AT_FUNC_USE_F1_COND \ - ? AT_FUNC_F1 (F AT_FUNC_POST_FILE_ARGS) \ +#include "dosname.h" /* solely for definition of IS_ABSOLUTE_FILE_NAME */ + +#ifdef GNULIB_SUPPORT_ONLY_AT_FDCWD +# include <errno.h> +# ifndef ENOTSUP +# define ENOTSUP EINVAL +# endif +#else +# include "openat.h" +# include "openat-priv.h" +# include "save-cwd.h" +#endif + +#ifdef AT_FUNC_USE_F1_COND +# define CALL_FUNC(F) \ + (flag == AT_FUNC_USE_F1_COND \ + ? AT_FUNC_F1 (F AT_FUNC_POST_FILE_ARGS) \ : AT_FUNC_F2 (F AT_FUNC_POST_FILE_ARGS)) +# define VALIDATE_FLAG(F) \ + if (flag & ~AT_FUNC_USE_F1_COND) \ + { \ + errno = EINVAL; \ + return FUNC_FAIL; \ + } +#else +# define CALL_FUNC(F) (AT_FUNC_F1 (F AT_FUNC_POST_FILE_ARGS)) +# define VALIDATE_FLAG(F) /* empty */ +#endif + +#ifdef AT_FUNC_RESULT +# define FUNC_RESULT AT_FUNC_RESULT +#else +# define FUNC_RESULT int +#endif -/* Call AT_FUNC_F1 or AT_FUNC_F2 (testing AT_FUNC_USE_F1_COND to - determine which) to operate on FILE, which is in the directory - open on descriptor FD. If possible, do it without changing the +#ifdef AT_FUNC_FAIL +# define FUNC_FAIL AT_FUNC_FAIL +#else +# define FUNC_FAIL -1 +#endif + +/* Call AT_FUNC_F1 to operate on FILE, which is in the directory + open on descriptor FD. If AT_FUNC_USE_F1_COND is defined to a value, + AT_FUNC_POST_FILE_PARAM_DECLS must include a parameter named flag; + call AT_FUNC_F2 if FLAG is 0 or fail if FLAG contains more bits than + AT_FUNC_USE_F1_COND. Return int and fail with -1 unless AT_FUNC_RESULT + or AT_FUNC_FAIL are defined. If possible, do it without changing the working directory. Otherwise, resort to using save_cwd/fchdir, then AT_FUNC_F?/restore_cwd. If either the save_cwd or the restore_cwd fails, then give a diagnostic and exit nonzero. */ -int +FUNC_RESULT AT_FUNC_NAME (int fd, char const *file AT_FUNC_POST_FILE_PARAM_DECLS) { - struct saved_cwd saved_cwd; - int saved_errno; - int err; + VALIDATE_FLAG (flag); if (fd == AT_FDCWD || IS_ABSOLUTE_FILE_NAME (file)) return CALL_FUNC (file); +#ifdef GNULIB_SUPPORT_ONLY_AT_FDCWD + errno = ENOTSUP; + return FUNC_FAIL; +#else { - char buf[OPENAT_BUFFER_SIZE]; - char *proc_file = openat_proc_name (buf, fd, file); + /* Be careful to choose names unlikely to conflict with + AT_FUNC_POST_FILE_PARAM_DECLS. */ + struct saved_cwd saved_cwd; + int saved_errno; + FUNC_RESULT err; + + { + char proc_buf[OPENAT_BUFFER_SIZE]; + char *proc_file = openat_proc_name (proc_buf, fd, file); if (proc_file) { - int proc_result = CALL_FUNC (proc_file); - int proc_errno = errno; - if (proc_file != buf) - free (proc_file); - /* If the syscall succeeds, or if it fails with an unexpected - errno value, then return right away. Otherwise, fall through - and resort to using save_cwd/restore_cwd. */ - if (0 <= proc_result) - return proc_result; - if (! EXPECTED_ERRNO (proc_errno)) - { - errno = proc_errno; - return proc_result; - } + FUNC_RESULT proc_result = CALL_FUNC (proc_file); + int proc_errno = errno; + if (proc_file != proc_buf) + free (proc_file); + /* If the syscall succeeds, or if it fails with an unexpected + errno value, then return right away. Otherwise, fall through + and resort to using save_cwd/restore_cwd. */ + if (FUNC_FAIL != proc_result) + return proc_result; + if (! EXPECTED_ERRNO (proc_errno)) + { + errno = proc_errno; + return proc_result; + } } } if (save_cwd (&saved_cwd) != 0) openat_save_fail (errno); + if (0 <= fd && fd == saved_cwd.desc) + { + /* If saving the working directory collides with the user's + requested fd, then the user's fd must have been closed to + begin with. */ + free_cwd (&saved_cwd); + errno = EBADF; + return FUNC_FAIL; + } if (fchdir (fd) != 0) { saved_errno = errno; free_cwd (&saved_cwd); errno = saved_errno; - return -1; + return FUNC_FAIL; } err = CALL_FUNC (file); - saved_errno = (err < 0 ? errno : 0); + saved_errno = (err == FUNC_FAIL ? errno : 0); if (restore_cwd (&saved_cwd) != 0) openat_restore_fail (errno); @@ -82,5 +138,9 @@ AT_FUNC_NAME (int fd, char const *file AT_FUNC_POST_FILE_PARAM_DECLS) if (saved_errno) errno = saved_errno; return err; + } +#endif } #undef CALL_FUNC +#undef FUNC_RESULT +#undef FUNC_FAIL |