#include "Python.h"

#include "osdefs.h"

#include <locale.h>

#ifdef MS_WINDOWS

# include <malloc.h>

# include <windows.h>

extern int winerror_to_errno(int);

#endif

#ifdef HAVE_LANGINFO_H

#include <langinfo.h>

#endif

#ifdef HAVE_SYS_IOCTL_H

#include <sys/ioctl.h>

#endif

#ifdef HAVE_FCNTL_H

#include <fcntl.h>

#endif /* HAVE_FCNTL_H */

extern wchar_t* _Py_DecodeUTF8_surrogateescape(const char *s, Py_ssize_t size,

size_t *p_wlen);

extern char* _Py_EncodeUTF8_surrogateescape(const wchar_t *text,

size_t *error_pos);

#ifdef O_CLOEXEC

/* Does open() support the O_CLOEXEC flag? Possible values:

-1: unknown

0: open() ignores O_CLOEXEC flag, ex: Linux kernel older than 2.6.23

1: open() supports O_CLOEXEC flag, close-on-exec is set

The flag is used by _Py_open(), _Py_open_noraise(), io.FileIO

and os.open(). */

int _Py_open_cloexec_works = -1;

#endif

PyObject *

_Py_device_encoding(int fd)

{

#if defined(MS_WINDOWS)

UINT cp;

#endif

int valid;

_Py_BEGIN_SUPPRESS_IPH

valid = isatty(fd);

_Py_END_SUPPRESS_IPH

if (!valid)

Py_RETURN_NONE;

#if defined(MS_WINDOWS)

if (fd == 0)

cp = GetConsoleCP();

else if (fd == 1 || fd == 2)

cp = GetConsoleOutputCP();

else

cp = 0;

/* GetConsoleCP() and GetConsoleOutputCP() return 0 if the application

has no console */

if (cp != 0)

return PyUnicode_FromFormat("cp%u", (unsigned int)cp);

#elif defined(CODESET)

{

char *codeset = nl_langinfo(CODESET);

if (codeset != NULL && codeset[0] != 0)

return PyUnicode_FromString(codeset);

}

#endif

Py_RETURN_NONE;

}

#if !defined(__APPLE__) && !defined(MS_WINDOWS)

extern int _Py_normalize_encoding(const char *, char *, size_t);

/* Workaround FreeBSD and OpenIndiana locale encoding issue with the C locale.

On these operating systems, nl_langinfo(CODESET) announces an alias of the

ASCII encoding, whereas mbstowcs() and wcstombs() functions use the

ISO-8859-1 encoding. The problem is that os.fsencode() and os.fsdecode() use

locale.getpreferredencoding() codec. For example, if command line arguments

are decoded by mbstowcs() and encoded back by os.fsencode(), we get a

UnicodeEncodeError instead of retrieving the original byte string.

The workaround is enabled if setlocale(LC_CTYPE, NULL) returns "C",

nl_langinfo(CODESET) announces "ascii" (or an alias to ASCII), and at least

one byte in range 0x80-0xff can be decoded from the locale encoding. The

workaround is also enabled on error, for example if getting the locale

failed.

Values of force_ascii:

1: the workaround is used: Py_EncodeLocale() uses

encode_ascii_surrogateescape() and Py_DecodeLocale() uses

decode_ascii_surrogateescape()

0: the workaround is not used: Py_EncodeLocale() uses wcstombs() and

Py_DecodeLocale() uses mbstowcs()

-1: unknown, need to call check_force_ascii() to get the value

*/

static int force_ascii = -1;

static int

check_force_ascii(void)

{

char *loc;

#if defined(HAVE_LANGINFO_H) && defined(CODESET)

char *codeset, **alias;

char encoding[20]; /* longest name: "iso_646.irv_1991\0" */

int is_ascii;

unsigned int i;

char* ascii_aliases[] = {

"ascii",

/* Aliases from Lib/encodings/aliases.py */

"646",

"ansi_x3.4_1968",

"ansi_x3.4_1986",

"ansi_x3_4_1968",

"cp367",

"csascii",

"ibm367",

"iso646_us",

"iso_646.irv_1991",

"iso_ir_6",

"us",

"us_ascii",

NULL

};

#endif

loc = setlocale(LC_CTYPE, NULL);

if (loc == NULL)

goto error;

if (strcmp(loc, "C") != 0) {

/* the LC_CTYPE locale is different than C */

return 0;

}

#if defined(HAVE_LANGINFO_H) && defined(CODESET)

codeset = nl_langinfo(CODESET);

if (!codeset || codeset[0] == '\0') {

/* CODESET is not set or empty */

goto error;

}

if (!_Py_normalize_encoding(codeset, encoding, sizeof(encoding)))

goto error;

is_ascii = 0;

for (alias=ascii_aliases; *alias != NULL; alias++) {

if (strcmp(encoding, *alias) == 0) {

is_ascii = 1;

break;

}

}

if (!is_ascii) {

/* nl_langinfo(CODESET) is not "ascii" or an alias of ASCII */

return 0;

}

for (i=0x80; i<0xff; i++) {

unsigned char ch;

wchar_t wch;

size_t res;

ch = (unsigned char)i;

res = mbstowcs(&wch, (char*)&ch, 1);

if (res != (size_t)-1) {

/* decoding a non-ASCII character from the locale encoding succeed:

the locale encoding is not ASCII, force ASCII */

return 1;

}

}

/* None of the bytes in the range 0x80-0xff can be decoded from the locale

encoding: the locale encoding is really ASCII */

return 0;

#else

/* nl_langinfo(CODESET) is not available: always force ASCII */

return 1;

#endif

error:

/* if an error occurred, force the ASCII encoding */

return 1;

}

static char*

encode_ascii_surrogateescape(const wchar_t *text, size_t *error_pos)

{

char *result = NULL, *out;

size_t len, i;

wchar_t ch;

if (error_pos != NULL)

*error_pos = (size_t)-1;

len = wcslen(text);

result = PyMem_Malloc(len + 1); /* +1 for NUL byte */

if (result == NULL)

return NULL;

out = result;

for (i=0; i<len; i++) {

ch = text[i];

if (ch <= 0x7f) {

/* ASCII character */

*out++ = (char)ch;

}

else if (0xdc80 <= ch && ch <= 0xdcff) {

/* UTF-8b surrogate */

*out++ = (char)(ch - 0xdc00);

}

else {

if (error_pos != NULL)

*error_pos = i;

PyMem_Free(result);

return NULL;

}

}

*out = '\0';

return result;

}

#endif /* !defined(__APPLE__) && !defined(MS_WINDOWS) */

#if !defined(__APPLE__) && (!defined(MS_WINDOWS) || !defined(HAVE_MBRTOWC))

static wchar_t*

decode_ascii_surrogateescape(const char *arg, size_t *size)

{

wchar_t *res;

unsigned char *in;

wchar_t *out;

size_t argsize = strlen(arg) + 1;

if (argsize > PY_SSIZE_T_MAX/sizeof(wchar_t))

return NULL;

res = PyMem_RawMalloc(argsize*sizeof(wchar_t));

if (!res)

return NULL;

in = (unsigned char*)arg;

out = res;

while(*in)

if(*in < 128)

*out++ = *in++;

else

*out++ = 0xdc00 + *in++;

*out = 0;

if (size != NULL)

*size = out - res;

return res;

}

#endif

#if !defined(__APPLE__) && !defined(__ANDROID__)

static wchar_t*

decode_locale(const char* arg, size_t *size)

{

wchar_t *res;

size_t argsize;

size_t count;

#ifdef HAVE_MBRTOWC

unsigned char *in;

wchar_t *out;

mbstate_t mbs;

#endif

#ifdef HAVE_BROKEN_MBSTOWCS

/* Some platforms have a broken implementation of

* mbstowcs which does not count the characters that

* would result from conversion. Use an upper bound.

*/

argsize = strlen(arg);

#else

argsize = mbstowcs(NULL, arg, 0);

#endif

if (argsize != (size_t)-1) {

if (argsize == PY_SSIZE_T_MAX)

goto oom;

argsize += 1;

if (argsize > PY_SSIZE_T_MAX/sizeof(wchar_t))

goto oom;

res = (wchar_t *)PyMem_RawMalloc(argsize*sizeof(wchar_t));

if (!res)

goto oom;

count = mbstowcs(res, arg, argsize);

if (count != (size_t)-1) {

wchar_t *tmp;

/* Only use the result if it contains no

surrogate characters. */

for (tmp = res; *tmp != 0 &&

!Py_UNICODE_IS_SURROGATE(*tmp); tmp++)

;

if (*tmp == 0) {

if (size != NULL)

*size = count;

return res;

}

}

PyMem_RawFree(res);

}

/* Conversion failed. Fall back to escaping with surrogateescape. */

#ifdef HAVE_MBRTOWC

/* Try conversion with mbrtwoc (C99), and escape non-decodable bytes. */

/* Overallocate; as multi-byte characters are in the argument, the

actual output could use less memory. */

argsize = strlen(arg) + 1;

if (argsize > PY_SSIZE_T_MAX/sizeof(wchar_t))

goto oom;

res = (wchar_t*)PyMem_RawMalloc(argsize*sizeof(wchar_t));

if (!res)

goto oom;

in = (unsigned char*)arg;

out = res;

memset(&mbs, 0, sizeof mbs);

while (argsize) {

size_t converted = mbrtowc(out, (char*)in, argsize, &mbs);

if (converted == 0)

/* Reached end of string; null char stored. */

break;

if (converted == (size_t)-2) {

/* Incomplete character. This should never happen,

since we provide everything that we have -

unless there is a bug in the C library, or I

misunderstood how mbrtowc works. */

PyMem_RawFree(res);

if (size != NULL)

*size = (size_t)-2;

return NULL;

}

if (converted == (size_t)-1) {

/* Conversion error. Escape as UTF-8b, and start over

in the initial shift state. */

*out++ = 0xdc00 + *in++;

argsize--;

memset(&mbs, 0, sizeof mbs);

continue;

}

if (Py_UNICODE_IS_SURROGATE(*out)) {

/* Surrogate character. Escape the original

byte sequence with surrogateescape. */

argsize -= converted;

while (converted--)

*out++ = 0xdc00 + *in++;

continue;

}

/* successfully converted some bytes */

in += converted;

argsize -= converted;

out++;

}

if (size != NULL)

*size = out - res;

#else /* HAVE_MBRTOWC */

/* Cannot use C locale for escaping; manually escape as if charset

is ASCII (i.e. escape all bytes > 128. This will still roundtrip

correctly in the locale's charset, which must be an ASCII superset. */

res = decode_ascii_surrogateescape(arg, size);

if (res == NULL)

goto oom;

#endif /* HAVE_MBRTOWC */

return res;

oom:

if (size != NULL) {

*size = (size_t)-1;

}

return NULL;

}

#endif

/* Decode a byte string from the locale encoding with the

surrogateescape error handler: undecodable bytes are decoded as characters

in range U+DC80..U+DCFF. If a byte sequence can be decoded as a surrogate

character, escape the bytes using the surrogateescape error handler instead

of decoding them.

Return a pointer to a newly allocated wide character string, use

PyMem_RawFree() to free the memory. If size is not NULL, write the number of

wide characters excluding the null character into *size

Return NULL on decoding error or memory allocation error. If *size* is not

NULL, *size is set to (size_t)-1 on memory error or set to (size_t)-2 on

decoding error.

Decoding errors should never happen, unless there is a bug in the C

library.

Use the Py_EncodeLocale() function to encode the character string back to a

byte string. */

wchar_t*

Py_DecodeLocale(const char* arg, size_t *size)

{

#if defined(__APPLE__) || defined(__ANDROID__)

return _Py_DecodeUTF8_surrogateescape(arg, strlen(arg), size);

#else

if (Py_UTF8Mode == 1) {

return _Py_DecodeUTF8_surrogateescape(arg, strlen(arg), size);

}

#ifndef MS_WINDOWS

if (force_ascii == -1)

force_ascii = check_force_ascii();

if (force_ascii) {

/* force ASCII encoding to workaround mbstowcs() issue */

wchar_t *wstr = decode_ascii_surrogateescape(arg, size);

if (wstr == NULL) {

if (size != NULL) {

*size = (size_t)-1;

}

return NULL;

}

return wstr;

}

#endif

return decode_locale(arg, size);

#endif /* __APPLE__ or __ANDROID__ */

}

#if !defined(__APPLE__) && !defined(__ANDROID__)

static char*

encode_locale(const wchar_t *text, size_t *error_pos)

{

const size_t len = wcslen(text);

char *result = NULL, *bytes = NULL;

size_t i, size, converted;

wchar_t c, buf[2];

/* The function works in two steps:

1. compute the length of the output buffer in bytes (size)

2. outputs the bytes */

size = 0;

buf[1] = 0;

while (1) {

for (i=0; i < len; i++) {

c = text[i];

if (c >= 0xdc80 && c <= 0xdcff) {

/* UTF-8b surrogate */

if (bytes != NULL) {

*bytes++ = c - 0xdc00;

size--;

}

else

size++;

continue;

}

else {

buf[0] = c;

if (bytes != NULL)

converted = wcstombs(bytes, buf, size);

else

converted = wcstombs(NULL, buf, 0);

if (converted == (size_t)-1) {

if (result != NULL)

PyMem_Free(result);

if (error_pos != NULL)

*error_pos = i;

return NULL;

}

if (bytes != NULL) {

bytes += converted;

size -= converted;

}

else

size += converted;

}

}

if (result != NULL) {

*bytes = '\0';

break;

}

size += 1; /* nul byte at the end */

result = PyMem_Malloc(size);

if (result == NULL) {

if (error_pos != NULL)

*error_pos = (size_t)-1;

return NULL;

}

bytes = result;

}

return result;

}

#endif

/* Encode a wide character string to the locale encoding with the

surrogateescape error handler: surrogate characters in the range

U+DC80..U+DCFF are converted to bytes 0x80..0xFF.

Return a pointer to a newly allocated byte string, use PyMem_Free() to free

the memory. Return NULL on encoding or memory allocation error.

If error_pos is not NULL, *error_pos is set to (size_t)-1 on success, or set

to the index of the invalid character on encoding error.

Use the Py_DecodeLocale() function to decode the bytes string back to a wide

character string. */

char*

Py_EncodeLocale(const wchar_t *text, size_t *error_pos)

{

#if defined(__APPLE__) || defined(__ANDROID__)

return _Py_EncodeUTF8_surrogateescape(text, error_pos);

#else /* __APPLE__ */

if (Py_UTF8Mode == 1) {

return _Py_EncodeUTF8_surrogateescape(text, error_pos);

}

#ifndef MS_WINDOWS

if (force_ascii == -1)

force_ascii = check_force_ascii();

if (force_ascii)

return encode_ascii_surrogateescape(text, error_pos);

#endif

return encode_locale(text, error_pos);

#endif /* __APPLE__ or __ANDROID__ */

}

#ifdef MS_WINDOWS

static __int64 secs_between_epochs = 11644473600; /* Seconds between 1.1.1601 and 1.1.1970 */

static void

FILE_TIME_to_time_t_nsec(FILETIME *in_ptr, time_t *time_out, int* nsec_out)

{

/* XXX endianness. Shouldn't matter, as all Windows implementations are little-endian */

/* Cannot simply cast and dereference in_ptr,

since it might not be aligned properly */

__int64 in;

memcpy(&in, in_ptr, sizeof(in));

*nsec_out = (int)(in % 10000000) * 100; /* FILETIME is in units of 100 nsec. */

*time_out = Py_SAFE_DOWNCAST((in / 10000000) - secs_between_epochs, __int64, time_t);

}

void

_Py_time_t_to_FILE_TIME(time_t time_in, int nsec_in, FILETIME *out_ptr)

{

/* XXX endianness */

__int64 out;

out = time_in + secs_between_epochs;

out = out * 10000000 + nsec_in / 100;

memcpy(out_ptr, &out, sizeof(out));

}

/* Below, we *know* that ugo+r is 0444 */

#if _S_IREAD != 0400

#error Unsupported C library

#endif

static int

attributes_to_mode(DWORD attr)

{

int m = 0;

if (attr & FILE_ATTRIBUTE_DIRECTORY)

m |= _S_IFDIR | 0111; /* IFEXEC for user,group,other */

else

m |= _S_IFREG;

if (attr & FILE_ATTRIBUTE_READONLY)

m |= 0444;

else

m |= 0666;

return m;

}

void

_Py_attribute_data_to_stat(BY_HANDLE_FILE_INFORMATION *info, ULONG reparse_tag,

struct _Py_stat_struct *result)

{

memset(result, 0, sizeof(*result));

result->st_mode = attributes_to_mode(info->dwFileAttributes);

result->st_size = (((__int64)info->nFileSizeHigh)<<32) + info->nFileSizeLow;

result->st_dev = info->dwVolumeSerialNumber;

result->st_rdev = result->st_dev;

FILE_TIME_to_time_t_nsec(&info->ftCreationTime, &result->st_ctime, &result->st_ctime_nsec);

FILE_TIME_to_time_t_nsec(&info->ftLastWriteTime, &result->st_mtime, &result->st_mtime_nsec);

FILE_TIME_to_time_t_nsec(&info->ftLastAccessTime, &result->st_atime, &result->st_atime_nsec);

result->st_nlink = info->nNumberOfLinks;

result->st_ino = (((uint64_t)info->nFileIndexHigh) << 32) + info->nFileIndexLow;

if (reparse_tag == IO_REPARSE_TAG_SYMLINK) {

/* first clear the S_IFMT bits */

result->st_mode ^= (result->st_mode & S_IFMT);

/* now set the bits that make this a symlink */

result->st_mode |= S_IFLNK;

}

result->st_file_attributes = info->dwFileAttributes;

}

#endif

/* Return information about a file.

On POSIX, use fstat().

On Windows, use GetFileType() and GetFileInformationByHandle() which support

files larger than 2 GiB. fstat() may fail with EOVERFLOW on files larger

than 2 GiB because the file size type is a signed 32-bit integer: see issue

#23152.

On Windows, set the last Windows error and return nonzero on error. On

POSIX, set errno and return nonzero on error. Fill status and return 0 on

success. */

int

_Py_fstat_noraise(int fd, struct _Py_stat_struct *status)

{

#ifdef MS_WINDOWS

BY_HANDLE_FILE_INFORMATION info;

HANDLE h;

int type;

_Py_BEGIN_SUPPRESS_IPH

h = (HANDLE)_get_osfhandle(fd);

_Py_END_SUPPRESS_IPH

if (h == INVALID_HANDLE_VALUE) {

/* errno is already set by _get_osfhandle, but we also set

the Win32 error for callers who expect that */

SetLastError(ERROR_INVALID_HANDLE);

return -1;

}

memset(status, 0, sizeof(*status));

type = GetFileType(h);

if (type == FILE_TYPE_UNKNOWN) {

DWORD error = GetLastError();

if (error != 0) {

errno = winerror_to_errno(error);

return -1;

}

/* else: valid but unknown file */

}

if (type != FILE_TYPE_DISK) {

if (type == FILE_TYPE_CHAR)

status->st_mode = _S_IFCHR;

else if (type == FILE_TYPE_PIPE)

status->st_mode = _S_IFIFO;

return 0;

}

if (!GetFileInformationByHandle(h, &info)) {

/* The Win32 error is already set, but we also set errno for

callers who expect it */

errno = winerror_to_errno(GetLastError());

return -1;

}

_Py_attribute_data_to_stat(&info, 0, status);

/* specific to fstat() */

status->st_ino = (((uint64_t)info.nFileIndexHigh) << 32) + info.nFileIndexLow;

return 0;

#else

return fstat(fd, status);

#endif

}

/* Return information about a file.

On POSIX, use fstat().

On Windows, use GetFileType() and GetFileInformationByHandle() which support

files larger than 2 GiB. fstat() may fail with EOVERFLOW on files larger

than 2 GiB because the file size type is a signed 32-bit integer: see issue

#23152.

Raise an exception and return -1 on error. On Windows, set the last Windows

error on error. On POSIX, set errno on error. Fill status and return 0 on

success.

Release the GIL to call GetFileType() and GetFileInformationByHandle(), or

to call fstat(). The caller must hold the GIL. */

int

_Py_fstat(int fd, struct _Py_stat_struct *status)

{

int res;

assert(PyGILState_Check());

Py_BEGIN_ALLOW_THREADS

res = _Py_fstat_noraise(fd, status);

Py_END_ALLOW_THREADS

if (res != 0) {

#ifdef MS_WINDOWS

PyErr_SetFromWindowsErr(0);

#else

PyErr_SetFromErrno(PyExc_OSError);

#endif

return -1;

}

return 0;

}

/* Call _wstat() on Windows, or encode the path to the filesystem encoding and

call stat() otherwise. Only fill st_mode attribute on Windows.

Return 0 on success, -1 on _wstat() / stat() error, -2 if an exception was

raised. */

int

_Py_stat(PyObject *path, struct stat *statbuf)

{

#ifdef MS_WINDOWS

int err;

struct _stat wstatbuf;

const wchar_t *wpath;

wpath = _PyUnicode_AsUnicode(path);

if (wpath == NULL)

return -2;

err = _wstat(wpath, &wstatbuf);

if (!err)

statbuf->st_mode = wstatbuf.st_mode;

return err;

#else

int ret;

PyObject *bytes;

char *cpath;

bytes = PyUnicode_EncodeFSDefault(path);

if (bytes == NULL)

return -2;

/* check for embedded null bytes */

if (PyBytes_AsStringAndSize(bytes, &cpath, NULL) == -1) {

Py_DECREF(bytes);

return -2;

}

ret = stat(cpath, statbuf);

Py_DECREF(bytes);

return ret;

#endif

}

static int

get_inheritable(int fd, int raise)

{

#ifdef MS_WINDOWS

HANDLE handle;

DWORD flags;

_Py_BEGIN_SUPPRESS_IPH

handle = (HANDLE)_get_osfhandle(fd);

_Py_END_SUPPRESS_IPH

if (handle == INVALID_HANDLE_VALUE) {

if (raise)

PyErr_SetFromErrno(PyExc_OSError);

return -1;

}

if (!GetHandleInformation(handle, &flags)) {

if (raise)

PyErr_SetFromWindowsErr(0);

return -1;

}

return (flags & HANDLE_FLAG_INHERIT);

#else

int flags;

flags = fcntl(fd, F_GETFD, 0);

if (flags == -1) {

if (raise)

PyErr_SetFromErrno(PyExc_OSError);

return -1;

}

return !(flags & FD_CLOEXEC);

#endif

}

/* Get the inheritable flag of the specified file descriptor.

Return 1 if the file descriptor can be inherited, 0 if it cannot,

raise an exception and return -1 on error. */

int

_Py_get_inheritable(int fd)

{

return get_inheritable(fd, 1);

}

static int

set_inheritable(int fd, int inheritable, int raise, int *atomic_flag_works)

{

#ifdef MS_WINDOWS

HANDLE handle;

DWORD flags;

#else

#if defined(HAVE_SYS_IOCTL_H) && defined(FIOCLEX) && defined(FIONCLEX)

static int ioctl_works = -1;

int request;

int err;

#endif

int flags, new_flags;

int res;

#endif

/* atomic_flag_works can only be used to make the file descriptor

non-inheritable */

assert(!(atomic_flag_works != NULL && inheritable));

if (atomic_flag_works != NULL && !inheritable) {

if (*atomic_flag_works == -1) {

int isInheritable = get_inheritable(fd, raise);

if (isInheritable == -1)

return -1;

*atomic_flag_works = !isInheritable;

}

if (*atomic_flag_works)

return 0;

}

#ifdef MS_WINDOWS

_Py_BEGIN_SUPPRESS_IPH

handle = (HANDLE)_get_osfhandle(fd);

_Py_END_SUPPRESS_IPH

if (handle == INVALID_HANDLE_VALUE) {

if (raise)

PyErr_SetFromErrno(PyExc_OSError);

return -1;

}

if (inheritable)

flags = HANDLE_FLAG_INHERIT;

else

flags = 0;

if (!SetHandleInformation(handle, HANDLE_FLAG_INHERIT, flags)) {

if (raise)

PyErr_SetFromWindowsErr(0);

return -1;

}

return 0;

#else

#if defined(HAVE_SYS_IOCTL_H) && defined(FIOCLEX) && defined(FIONCLEX)

if (ioctl_works != 0) {

/* fast-path: ioctl() only requires one syscall */

if (inheritable)

request = FIONCLEX;

else

request = FIOCLEX;

err = ioctl(fd, request, NULL);

if (!err) {

ioctl_works = 1;

return 0;

}

if (errno != ENOTTY && errno != EACCES) {

if (raise)

PyErr_SetFromErrno(PyExc_OSError);

return -1;

}

else {

/* Issue #22258: Here, ENOTTY means "Inappropriate ioctl for

device". The ioctl is declared but not supported by the kernel.

Remember that ioctl() doesn't work. It is the case on

Illumos-based OS for example.

Issue #27057: When SELinux policy disallows ioctl it will fail

with EACCES. While FIOCLEX is safe operation it may be

unavailable because ioctl was denied altogether.

This can be the case on Android. */

ioctl_works = 0;

}

/* fallback to fcntl() if ioctl() does not work */

}

#endif

/* slow-path: fcntl() requires two syscalls */

flags = fcntl(fd, F_GETFD);

if (flags < 0) {

if (raise)

PyErr_SetFromErrno(PyExc_OSError);

return -1;

}

if (inheritable) {

new_flags = flags & ~FD_CLOEXEC;

}

else {

new_flags = flags | FD_CLOEXEC;

}

if (new_flags == flags) {

/* FD_CLOEXEC flag already set/cleared: nothing to do */

return 0;

}

res = fcntl(fd, F_SETFD, new_flags);

if (res < 0) {

if (raise)

PyErr_SetFromErrno(PyExc_OSError);

return -1;

}

return 0;

#endif

}

/* Make the file descriptor non-inheritable.

Return 0 on success, set errno and return -1 on error. */

static int

make_non_inheritable(int fd)

{

return set_inheritable(fd, 0, 0, NULL);

}

/* Set the inheritable flag of the specified file descriptor.

On success: return 0, on error: raise an exception if raise is nonzero

and return -1.

If atomic_flag_works is not NULL:

* if *atomic_flag_works==-1, check if the inheritable is set on the file

descriptor: if yes, set *atomic_flag_works to 1, otherwise set to 0 and

set the inheritable flag

* if *atomic_flag_works==1: do nothing

* if *atomic_flag_works==0: set inheritable flag to False

Set atomic_flag_works to NULL if no atomic flag was used to create the

file descriptor.

atomic_flag_works can only be used to make a file descriptor

non-inheritable: atomic_flag_works must be NULL if inheritable=1. */

int

_Py_set_inheritable(int fd, int inheritable, int *atomic_flag_works)

{

return set_inheritable(fd, inheritable, 1, atomic_flag_works);

}

static int

_Py_open_impl(const char *pathname, int flags, int gil_held)

{

int fd;

int async_err = 0;

#ifndef MS_WINDOWS

int *atomic_flag_works;

#endif

#ifdef MS_WINDOWS

flags |= O_NOINHERIT;

#elif defined(O_CLOEXEC)

atomic_flag_works = &_Py_open_cloexec_works;

flags |= O_CLOEXEC;

#else

atomic_flag_works = NULL;

#endif

if (gil_held) {

do {

Py_BEGIN_ALLOW_THREADS

fd = open(pathname, flags);

Py_END_ALLOW_THREADS

} while (fd < 0

&& errno == EINTR && !(async_err = PyErr_CheckSignals()));

if (async_err)

return -1;

if (fd < 0) {

PyErr_SetFromErrnoWithFilename(PyExc_OSError, pathname);

return -1;

}

}

else {

fd = open(pathname, flags);

if (fd < 0)

return -1;

}

#ifndef MS_WINDOWS

if (set_inheritable(fd, 0, gil_held, atomic_flag_works) < 0) {

close(fd);

return -1;

}

#endif

return fd;

}

/* Open a file with the specified flags (wrapper to open() function).

Return a file descriptor on success. Raise an exception and return -1 on

error.

The file descriptor is created non-inheritable.

When interrupted by a signal (open() fails with EINTR), retry the syscall,

except if the Python signal handler raises an exception.

Release the GIL to call open(). The caller must hold the GIL. */

int

_Py_open(const char *pathname, int flags)

{

/* _Py_open() must be called with the GIL held. */

assert(PyGILState_Check());

return _Py_open_impl(pathname, flags, 1);

}