/* Open a descriptor to a file.
- Copyright (C) 2007 Free Software Foundation, Inc.
+ Copyright (C) 2007-2013 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 Bruno Haible <bruno@clisp.org>, 2007. */
+/* If the user's config.h happens to include <fcntl.h>, let it include only
+ the system's <fcntl.h> here, so that orig_open doesn't recurse to
+ rpl_open. */
+#define __need_system_fcntl_h
#include <config.h>
-/* Specification. */
+/* 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
+
+static int
+orig_open (const char *filename, int flags, mode_t mode)
+{
+ return open (filename, flags, mode);
+}
+
+/* Specification. */
+/* 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"
-/* If the fchdir replacement is used, open() is defined in fchdir.c. */
-#ifndef FCHDIR_REPLACEMENT
+#include <errno.h>
+#include <stdarg.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
-# include <stdarg.h>
-# include <string.h>
-# include <sys/types.h>
-# include <sys/stat.h>
+#ifndef REPLACE_OPEN_DIRECTORY
+# define REPLACE_OPEN_DIRECTORY 0
+#endif
int
open (const char *filename, int flags, ...)
-# undef open
{
mode_t mode;
+ int fd;
mode = 0;
if (flags & O_CREAT)
va_list arg;
va_start (arg, flags);
- /* If mode_t is narrower than int, use the promoted type (int),
- not mode_t. Use sizeof to guess whether mode_t is narrower;
- we don't know of any practical counterexamples. */
- mode = (sizeof (mode_t) < sizeof (int)
- ? va_arg (arg, int)
- : va_arg (arg, mode_t));
+ /* 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 (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+#if GNULIB_defined_O_NONBLOCK
+ /* The only known platform that lacks O_NONBLOCK is mingw, but it
+ also lacks named pipes and Unix sockets, which are the only two
+ file types that require non-blocking handling in open().
+ Therefore, it is safe to ignore O_NONBLOCK here. It is handy
+ that mingw also lacks openat(), so that is also covered here. */
+ flags &= ~O_NONBLOCK;
+#endif
+
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
if (strcmp (filename, "/dev/null") == 0)
filename = "NUL";
-# endif
+#endif
- return open (filename, flags, mode);
-}
+#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_open (filename, flags, mode);
+
+#if REPLACE_FCHDIR
+ /* Implementing fchdir and fdopendir requires the ability to open a
+ directory file descriptor. If open doesn't support that (as on
+ mingw), we use a dummy file that behaves the same as directories
+ on Linux (ie. always reports EOF on attempts to read()), and
+ override fstat() in fchdir.c to hide the fact that we have a
+ dummy. */
+ if (REPLACE_OPEN_DIRECTORY && fd < 0 && errno == EACCES
+ && ((flags & O_ACCMODE) == O_RDONLY
+ || (O_SEARCH != O_RDONLY && (flags & O_ACCMODE) == O_SEARCH)))
+ {
+ struct stat statbuf;
+ if (stat (filename, &statbuf) == 0 && S_ISDIR (statbuf.st_mode))
+ {
+ /* Maximum recursion depth of 1. */
+ fd = open ("/dev/null", flags, mode);
+ if (0 <= fd)
+ fd = _gl_register_fd (fd, filename);
+ }
+ else
+ errno = EACCES;
+ }
+#endif
+
+#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
+
+#if REPLACE_FCHDIR
+ if (!REPLACE_OPEN_DIRECTORY && 0 <= fd)
+ fd = _gl_register_fd (fd, filename);
+#endif
+
+ return fd;
+}
projects / gnulib.git / blobdiff