X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fopen.c;h=a0c43eadf9745f686ec74231e8379715fa504080;hb=23eecb48e39afd0d267d64d40ba6bf97aa865e13;hp=48213689669fac8a3bca80fd8a718d1d18b5369e;hpb=8346ecd045f052983f69eb2c1d39e89e911aed87;p=gnulib.git diff --git a/lib/open.c b/lib/open.c index 482136896..a0c43eadf 100644 --- a/lib/open.c +++ b/lib/open.c @@ -1,5 +1,5 @@ /* Open a descriptor to a file. - Copyright (C) 2007-2008 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 @@ -16,25 +16,44 @@ /* Written by Bruno Haible , 2007. */ +/* If the user's config.h happens to include , let it include only + the system's here, so that orig_open doesn't recurse to + rpl_open. */ +#define __need_system_fcntl_h #include -/* Specification. */ +/* Get the original definition of open. It might be defined as a macro. */ #include +#include +#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 , otherwise OSF/1 5.1 DTK cc eliminates + this include because of the preliminary #include above. */ +#include "fcntl.h" -/* If the fchdir replacement is used, open() is defined in fchdir.c. */ -#ifndef FCHDIR_REPLACEMENT +#include +#include +#include +#include +#include +#include -# include -# include -# include -# include -# include +#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) @@ -42,33 +61,121 @@ open (const char *filename, int flags, ...) 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 OPEN_TRAILING_SLASH_BUG +#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 + +#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 + 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 + 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; - } + { + errno = EISDIR; + return -1; + } } -# endif +#endif -# if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ - if (strcmp (filename, "/dev/null") == 0) - filename = "NUL"; -# endif + fd = orig_open (filename, flags, mode); - return 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 + 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; +}