/* provide a replacement openat function
- Copyright (C) 2004-2009 Free Software Foundation, Inc.
+ Copyright (C) 2004-2013 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
/* written by Jim Meyering */
+/* If the user's config.h happens to include <fcntl.h>, let it include only
+ the system's <fcntl.h> here, so that orig_openat doesn't recurse to
+ rpl_openat. */
+#define __need_system_fcntl_h
#include <config.h>
+/* Get the original definition of open. It might be defined as a macro. */
+#include <fcntl.h>
+#include <sys/types.h>
+#undef __need_system_fcntl_h
+
+#if HAVE_OPENAT
+static int
+orig_openat (int fd, char const *filename, int flags, mode_t mode)
+{
+ return openat (fd, filename, flags, mode);
+}
+#endif
+
+/* Write "fcntl.h" here, not <fcntl.h>, otherwise OSF/1 5.1 DTK cc eliminates
+ this include because of the preliminary #include <fcntl.h> above. */
+#include "fcntl.h"
+
#include "openat.h"
#include <stdarg.h>
+#include <stdbool.h>
#include <stddef.h>
+#include <string.h>
#include <sys/stat.h>
+#include <errno.h>
+
+#if HAVE_OPENAT
+
+/* Like openat, but work around Solaris 9 bugs with trailing slash. */
+int
+rpl_openat (int dfd, char const *filename, int flags, ...)
+{
+ mode_t mode;
+ int fd;
+
+ mode = 0;
+ if (flags & O_CREAT)
+ {
+ va_list arg;
+ va_start (arg, flags);
-#include "dirname.h" /* solely for definition of IS_ABSOLUTE_FILE_NAME */
-#include "fcntl--.h"
-#include "openat-priv.h"
-#include "save-cwd.h"
+ /* We have to use PROMOTED_MODE_T instead of mode_t, otherwise GCC 4
+ creates crashing code when 'mode_t' is smaller than 'int'. */
+ mode = va_arg (arg, PROMOTED_MODE_T);
+
+ va_end (arg);
+ }
+
+# if OPEN_TRAILING_SLASH_BUG
+ /* If the filename ends in a slash and one of O_CREAT, O_WRONLY, O_RDWR
+ is specified, then fail.
+ Rationale: POSIX <http://www.opengroup.org/susv3/basedefs/xbd_chap04.html>
+ says that
+ "A pathname that contains at least one non-slash character and that
+ ends with one or more trailing slashes shall be resolved as if a
+ single dot character ( '.' ) were appended to the pathname."
+ and
+ "The special filename dot shall refer to the directory specified by
+ its predecessor."
+ If the named file already exists as a directory, then
+ - if O_CREAT is specified, open() must fail because of the semantics
+ of O_CREAT,
+ - if O_WRONLY or O_RDWR is specified, open() must fail because POSIX
+ <http://www.opengroup.org/susv3/functions/open.html> says that it
+ fails with errno = EISDIR in this case.
+ If the named file does not exist or does not name a directory, then
+ - if O_CREAT is specified, open() must fail since open() cannot create
+ directories,
+ - if O_WRONLY or O_RDWR is specified, open() must fail because the
+ file does not contain a '.' directory. */
+ if (flags & (O_CREAT | O_WRONLY | O_RDWR))
+ {
+ size_t len = strlen (filename);
+ if (len > 0 && filename[len - 1] == '/')
+ {
+ errno = EISDIR;
+ return -1;
+ }
+ }
+# endif
+
+ fd = orig_openat (dfd, filename, flags, mode);
+
+# if OPEN_TRAILING_SLASH_BUG
+ /* If the filename ends in a slash and fd does not refer to a directory,
+ then fail.
+ Rationale: POSIX <http://www.opengroup.org/susv3/basedefs/xbd_chap04.html>
+ says that
+ "A pathname that contains at least one non-slash character and that
+ ends with one or more trailing slashes shall be resolved as if a
+ single dot character ( '.' ) were appended to the pathname."
+ and
+ "The special filename dot shall refer to the directory specified by
+ its predecessor."
+ If the named file without the slash is not a directory, open() must fail
+ with ENOTDIR. */
+ if (fd >= 0)
+ {
+ /* We know len is positive, since open did not fail with ENOENT. */
+ size_t len = strlen (filename);
+ if (filename[len - 1] == '/')
+ {
+ struct stat statbuf;
+
+ if (fstat (fd, &statbuf) >= 0 && !S_ISDIR (statbuf.st_mode))
+ {
+ close (fd);
+ errno = ENOTDIR;
+ return -1;
+ }
+ }
+ }
+# endif
+
+ return fd;
+}
+
+#else /* !HAVE_OPENAT */
+
+# include "dosname.h" /* solely for definition of IS_ABSOLUTE_FILE_NAME */
+# include "openat-priv.h"
+# include "save-cwd.h"
/* Replacement for Solaris' openat function.
<http://www.google.com/search?q=openat+site:docs.sun.com>
va_start (arg, flags);
/* We have to use PROMOTED_MODE_T instead of mode_t, otherwise GCC 4
- creates crashing code when 'mode_t' is smaller than 'int'. */
+ creates crashing code when 'mode_t' is smaller than 'int'. */
mode = va_arg (arg, PROMOTED_MODE_T);
va_end (arg);
directory argument.
If a previous attempt to restore the current working directory
- failed, then we must not even try to access a `.'-relative name.
+ failed, then we must not even try to access a '.'-relative name.
It is the caller's responsibility not to call this function
in that case. */
int
openat_permissive (int fd, char const *file, int flags, mode_t mode,
- int *cwd_errno)
+ int *cwd_errno)
{
struct saved_cwd saved_cwd;
int saved_errno;
char *proc_file = openat_proc_name (buf, fd, file);
if (proc_file)
{
- int open_result = open (proc_file, flags, mode);
- int open_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 <= open_result || ! EXPECTED_ERRNO (open_errno))
- {
- errno = open_errno;
- return open_result;
- }
+ int open_result = open (proc_file, flags, mode);
+ int open_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 <= open_result || ! EXPECTED_ERRNO (open_errno))
+ {
+ errno = open_errno;
+ return open_result;
+ }
}
}
if (! save_ok)
{
if (! cwd_errno)
- openat_save_fail (errno);
+ openat_save_fail (errno);
*cwd_errno = 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 -1;
+ }
err = fchdir (fd);
saved_errno = errno;
err = open (file, flags, mode);
saved_errno = errno;
if (save_ok && restore_cwd (&saved_cwd) != 0)
- {
- if (! cwd_errno)
- openat_restore_fail (errno);
- *cwd_errno = errno;
- }
+ {
+ if (! cwd_errno)
+ {
+ /* Don't write a message to just-created fd 2. */
+ saved_errno = errno;
+ if (err == STDERR_FILENO)
+ close (err);
+ openat_restore_fail (saved_errno);
+ }
+ *cwd_errno = errno;
+ }
}
free_cwd (&saved_cwd);
openat_needs_fchdir (void)
{
bool needs_fchdir = true;
- int fd = open ("/", O_RDONLY);
+ int fd = open ("/", O_SEARCH);
if (0 <= fd)
{
char buf[OPENAT_BUFFER_SIZE];
char *proc_file = openat_proc_name (buf, fd, ".");
if (proc_file)
- {
- needs_fchdir = false;
- if (proc_file != buf)
- free (proc_file);
- }
+ {
+ needs_fchdir = false;
+ if (proc_file != buf)
+ free (proc_file);
+ }
close (fd);
}
return needs_fchdir;
}
-#if !HAVE_FDOPENDIR
-
-/* Replacement for Solaris' function by the same name.
- <http://www.google.com/search?q=fdopendir+site:docs.sun.com>
- First, try to simulate it via opendir ("/proc/self/fd/FD"). Failing
- that, simulate it by doing save_cwd/fchdir/opendir(".")/restore_cwd.
- If either the save_cwd or the restore_cwd fails (relatively unlikely),
- then give a diagnostic and exit nonzero.
- Otherwise, this function works just like Solaris' fdopendir.
-
- W A R N I N G:
- Unlike the other fd-related functions here, this one
- effectively consumes its FD parameter. The caller should not
- close or otherwise manipulate FD if this function returns successfully. */
-DIR *
-fdopendir (int fd)
-{
- struct saved_cwd saved_cwd;
- int saved_errno;
- DIR *dir;
-
- char buf[OPENAT_BUFFER_SIZE];
- char *proc_file = openat_proc_name (buf, fd, ".");
- if (proc_file)
- {
- dir = opendir (proc_file);
- saved_errno = errno;
- }
- else
- {
- dir = NULL;
- saved_errno = EOPNOTSUPP;
- }
-
- /* If the syscall fails with an expected errno value, resort to
- save_cwd/restore_cwd. */
- if (! dir && EXPECTED_ERRNO (saved_errno))
- {
- if (save_cwd (&saved_cwd) != 0)
- openat_save_fail (errno);
-
- if (fchdir (fd) != 0)
- {
- dir = NULL;
- saved_errno = errno;
- }
- else
- {
- dir = opendir (".");
- saved_errno = errno;
-
- if (restore_cwd (&saved_cwd) != 0)
- openat_restore_fail (errno);
- }
-
- free_cwd (&saved_cwd);
- }
-
- if (dir)
- close (fd);
- if (proc_file != buf)
- free (proc_file);
- errno = saved_errno;
- return dir;
-}
-
-#endif
-
-/* Replacement for Solaris' function by the same name.
- <http://www.google.com/search?q=fstatat+site:docs.sun.com>
- First, try to simulate it via l?stat ("/proc/self/fd/FD/FILE").
- Failing that, simulate it via save_cwd/fchdir/(stat|lstat)/restore_cwd.
- If either the save_cwd or the restore_cwd fails (relatively unlikely),
- then give a diagnostic and exit nonzero.
- Otherwise, this function works just like Solaris' fstatat. */
-
-#define AT_FUNC_NAME fstatat
-#define AT_FUNC_F1 lstat
-#define AT_FUNC_F2 stat
-#define AT_FUNC_USE_F1_COND flag == AT_SYMLINK_NOFOLLOW
-#define AT_FUNC_POST_FILE_PARAM_DECLS , struct stat *st, int flag
-#define AT_FUNC_POST_FILE_ARGS , st
-#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
-
-/* Replacement for Solaris' function by the same name.
- <http://www.google.com/search?q=unlinkat+site:docs.sun.com>
- First, try to simulate it via (unlink|rmdir) ("/proc/self/fd/FD/FILE").
- Failing that, simulate it via save_cwd/fchdir/(unlink|rmdir)/restore_cwd.
- If either the save_cwd or the restore_cwd fails (relatively unlikely),
- then give a diagnostic and exit nonzero.
- Otherwise, this function works just like Solaris' unlinkat. */
-
-#define AT_FUNC_NAME unlinkat
-#define AT_FUNC_F1 rmdir
-#define AT_FUNC_F2 unlink
-#define AT_FUNC_USE_F1_COND flag == AT_REMOVEDIR
-#define AT_FUNC_POST_FILE_PARAM_DECLS , int flag
-#define AT_FUNC_POST_FILE_ARGS /* empty */
-#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
+#endif /* !HAVE_OPENAT */
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