X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fopenat.c;h=9d2f7d49c2946b5d710a9fee85bacbeef973d9bd;hb=1276a2c5f24c0c932426aca9c899fa524d2443f2;hp=7e46a2672be613f948bae41dd30b78de4ed63b45;hpb=4c45e93c58de6532275c22a9153ecdfe516928ff;p=gnulib.git diff --git a/lib/openat.c b/lib/openat.c index 7e46a2672..9d2f7d49c 100644 --- a/lib/openat.c +++ b/lib/openat.c @@ -1,5 +1,5 @@ /* provide a replacement openat function - Copyright (C) 2004-2009 Free Software Foundation, Inc. + Copyright (C) 2004-2014 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 @@ -16,23 +16,40 @@ /* written by Jim Meyering */ +/* If the user's config.h happens to include , let it include only + the system's here, so that orig_openat doesn't recurse to + rpl_openat. */ +#define __need_system_fcntl_h #include +/* Get the original definition of open. It might be defined as a macro. */ +#include +#include +#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 , otherwise OSF/1 5.1 DTK cc eliminates + this include because of the preliminary #include above. */ +#include "fcntl.h" + #include "openat.h" #include +#include #include #include #include - -#include "dirname.h" /* solely for definition of IS_ABSOLUTE_FILE_NAME */ -#include "openat-priv.h" -#include "save-cwd.h" +#include #if HAVE_OPENAT -# undef openat - /* Like openat, but work around Solaris 9 bugs with trailing slash. */ int rpl_openat (int dfd, char const *filename, int flags, ...) @@ -47,13 +64,13 @@ rpl_openat (int dfd, char const *filename, int flags, ...) 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); } -#if OPEN_TRAILING_SLASH_BUG +# 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 @@ -79,16 +96,16 @@ rpl_openat (int dfd, char const *filename, int flags, ...) { size_t len = strlen (filename); if (len > 0 && filename[len - 1] == '/') - { - errno = EISDIR; - return -1; - } + { + errno = EISDIR; + return -1; + } } -#endif +# endif - fd = openat (dfd, filename, flags, mode); + fd = orig_openat (dfd, filename, flags, mode); -#if OPEN_TRAILING_SLASH_BUG +# if OPEN_TRAILING_SLASH_BUG /* If the filename ends in a slash and fd does not refer to a directory, then fail. Rationale: POSIX @@ -103,26 +120,31 @@ rpl_openat (int dfd, char const *filename, int flags, ...) with ENOTDIR. */ if (fd >= 0) { + /* We know len is positive, since open did not fail with ENOENT. */ size_t len = strlen (filename); - if (len > 0 && filename[len - 1] == '/') - { - struct stat statbuf; - - if (fstat (fd, &statbuf) >= 0 && !S_ISDIR (statbuf.st_mode)) - { - close (fd); - errno = ENOTDIR; - return -1; - } - } + if (filename[len - 1] == '/') + { + struct stat statbuf; + + if (fstat (fd, &statbuf) >= 0 && !S_ISDIR (statbuf.st_mode)) + { + close (fd); + errno = ENOTDIR; + return -1; + } + } } -#endif +# 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. First, try to simulate it via open ("/proc/self/fd/FD/FILE"). @@ -142,7 +164,7 @@ openat (int fd, char const *file, int flags, ...) 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); @@ -158,13 +180,13 @@ openat (int fd, char const *file, int flags, ...) 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; @@ -179,18 +201,18 @@ openat_permissive (int fd, char const *file, int flags, mode_t mode, 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; + } } } @@ -198,9 +220,18 @@ openat_permissive (int fd, char const *file, int flags, mode_t mode, 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; @@ -210,17 +241,17 @@ openat_permissive (int fd, char const *file, int flags, mode_t mode, err = open (file, flags, mode); saved_errno = errno; if (save_ok && restore_cwd (&saved_cwd) != 0) - { - 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; - } + { + 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); @@ -234,18 +265,18 @@ bool 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); }