X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fopenat.c;h=18491a6f6d980f83533db563ee0ed4089283e165;hb=f9e83fd48cb5c5a0b5a65751710138d42c814402;hp=7e46a2672be613f948bae41dd30b78de4ed63b45;hpb=4c45e93c58de6532275c22a9153ecdfe516928ff;p=gnulib.git diff --git a/lib/openat.c b/lib/openat.c index 7e46a2672..18491a6f6 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) 2004-2011 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 @@ -25,7 +25,7 @@ #include #include -#include "dirname.h" /* solely for definition of IS_ABSOLUTE_FILE_NAME */ +#include "dosname.h" /* solely for definition of IS_ABSOLUTE_FILE_NAME */ #include "openat-priv.h" #include "save-cwd.h" @@ -47,13 +47,13 @@ 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 +79,16 @@ 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); -#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 @@ -103,20 +103,21 @@ 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; } @@ -142,7 +143,7 @@ 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); @@ -164,7 +165,7 @@ openat (int fd, char const *file, int flags, ...) 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 +180,18 @@ 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 +199,18 @@ 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 +220,17 @@ 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 +244,18 @@ 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); }