expose linux extended file system attributes (closes #12720)

This commit is contained in:
Benjamin Peterson 2011-08-31 22:15:17 -04:00
parent ab3bea6815
commit 799bd80d8a
6 changed files with 649 additions and 2 deletions

View file

@ -107,6 +107,10 @@ corresponding Unix manual entries for more information on calls.");
#include <sched.h>
#endif
#ifdef HAVE_ATTR_XATTR_H
#include <attr/xattr.h>
#endif
#if defined(__FreeBSD__) || defined(__DragonFly__) || defined(__APPLE__)
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
@ -9950,6 +9954,384 @@ posix_mkfifoat(PyObject *self, PyObject *args)
}
#endif
#ifdef HAVE_ATTR_XATTR_H
static int
try_getxattr(const char *path, const char *name,
ssize_t (*get)(const char *, const char *, void *, size_t),
Py_ssize_t buf_size, PyObject **res)
{
PyObject *value;
Py_ssize_t len;
assert(buf_size <= XATTR_SIZE_MAX);
value = PyBytes_FromStringAndSize(NULL, buf_size);
if (!value)
return 0;
Py_BEGIN_ALLOW_THREADS;
len = get(path, name, PyBytes_AS_STRING(value), buf_size);
Py_END_ALLOW_THREADS;
if (len < 0) {
Py_DECREF(value);
if (errno == ERANGE) {
value = NULL;
}
else {
posix_error();
return 0;
}
}
else if (len != buf_size) {
/* Can only shrink. */
_PyBytes_Resize(&value, len);
}
*res = value;
return 1;
}
static PyObject *
getxattr_common(const char *path, PyObject *name_obj,
ssize_t (*get)(const char *, const char *, void *, size_t))
{
PyObject *value;
const char *name = PyBytes_AS_STRING(name_obj);
/* Try a small value first. */
if (!try_getxattr(path, name, get, 128, &value))
return NULL;
if (value)
return value;
/* Now the maximum possible one. */
if (!try_getxattr(path, name, get, XATTR_SIZE_MAX, &value))
return NULL;
assert(value);
return value;
}
PyDoc_STRVAR(posix_getxattr__doc__,
"getxattr(path, attr) -> value\n\n\
Return the value of extended attribute *name* on *path*.");
static PyObject *
posix_getxattr(PyObject *self, PyObject *args)
{
PyObject *path, *res, *name;
if (!PyArg_ParseTuple(args, "O&O&:getxattr", PyUnicode_FSConverter, &path,
PyUnicode_FSConverter, &name))
return NULL;
res = getxattr_common(PyBytes_AS_STRING(path), name, getxattr);
Py_DECREF(path);
Py_DECREF(name);
return res;
}
PyDoc_STRVAR(posix_lgetxattr__doc__,
"lgetxattr(path, attr) -> value\n\n\
Like getxattr but don't follow symlinks.");
static PyObject *
posix_lgetxattr(PyObject *self, PyObject *args)
{
PyObject *path, *res, *name;
if (!PyArg_ParseTuple(args, "O&O&:lgetxattr", PyUnicode_FSConverter, &path,
PyUnicode_FSConverter, &name))
return NULL;
res = getxattr_common(PyBytes_AS_STRING(path), name, lgetxattr);
Py_DECREF(path);
Py_DECREF(name);
return res;
}
static ssize_t
wrap_fgetxattr(const char *path, const char *name, void *value, size_t size)
{
/* Hack to share code. */
return fgetxattr((int)(Py_uintptr_t)path, name, value, size);
}
PyDoc_STRVAR(posix_fgetxattr__doc__,
"fgetxattr(fd, attr) -> value\n\n\
Like getxattr but operate on a fd instead of a path.");
static PyObject *
posix_fgetxattr(PyObject *self, PyObject *args)
{
PyObject *res, *name;
int fd;
if (!PyArg_ParseTuple(args, "iO&:fgetxattr", &fd, PyUnicode_FSConverter, &name))
return NULL;
res = getxattr_common((const char *)(Py_uintptr_t)fd, name, wrap_fgetxattr);
Py_DECREF(name);
return res;
}
PyDoc_STRVAR(posix_setxattr__doc__,
"setxattr(path, attr, value, flags=0)\n\n\
Set extended attribute *attr* on *path* to *value*.");
static PyObject *
posix_setxattr(PyObject *self, PyObject *args)
{
PyObject *path, *name;
Py_buffer data;
int flags = 0, err;
if (!PyArg_ParseTuple(args, "O&O&y*|i:setxattr", PyUnicode_FSConverter,
&path, PyUnicode_FSConverter, &name, &data, &flags))
return NULL;
Py_BEGIN_ALLOW_THREADS;
err = setxattr(PyBytes_AS_STRING(path), PyBytes_AS_STRING(name),
data.buf, data.len, flags);
Py_END_ALLOW_THREADS;
Py_DECREF(path);
Py_DECREF(name);
PyBuffer_Release(&data);
if (err)
return posix_error();
Py_RETURN_NONE;
}
PyDoc_STRVAR(posix_lsetxattr__doc__,
"lsetxattr(path, attr, value, flags=0)\n\n\
Like setxattr but don't follow symlinks.");
static PyObject *
posix_lsetxattr(PyObject *self, PyObject *args)
{
PyObject *path, *name;
Py_buffer data;
int flags = 0, err;
if (!PyArg_ParseTuple(args, "O&O&y*|i:lsetxattr", PyUnicode_FSConverter,
&path, PyUnicode_FSConverter, &name, &data, &flags))
return NULL;
Py_BEGIN_ALLOW_THREADS;
err = lsetxattr(PyBytes_AS_STRING(path), PyBytes_AS_STRING(name),
data.buf, data.len, flags);
Py_END_ALLOW_THREADS;
Py_DECREF(path);
Py_DECREF(name);
PyBuffer_Release(&data);
if (err)
return posix_error();
Py_RETURN_NONE;
}
PyDoc_STRVAR(posix_fsetxattr__doc__,
"fsetxattr(fd, attr, value, flags=0)\n\n\
Like setxattr but operates on *fd* instead of a path.");
static PyObject *
posix_fsetxattr(PyObject *self, PyObject *args)
{
Py_buffer data;
const char *name;
int fd, flags = 0, err;
if (!PyArg_ParseTuple(args, "iO&y*|i:fsetxattr", &fd, PyUnicode_FSConverter,
&name, &data, &flags))
return NULL;
Py_BEGIN_ALLOW_THREADS;
err = fsetxattr(fd, PyBytes_AS_STRING(name), data.buf, data.len, flags);
Py_END_ALLOW_THREADS;
Py_DECREF(name);
PyBuffer_Release(&data);
if (err)
return posix_error();
Py_RETURN_NONE;
}
PyDoc_STRVAR(posix_removexattr__doc__,
"removexattr(path, attr)\n\n\
Remove extended attribute *attr* on *path*.");
static PyObject *
posix_removexattr(PyObject *self, PyObject *args)
{
PyObject *path, *name;
int err;
if (!PyArg_ParseTuple(args, "O&O&:removexattr", PyUnicode_FSConverter, &path,
PyUnicode_FSConverter, &name))
return NULL;
Py_BEGIN_ALLOW_THREADS;
err = removexattr(PyBytes_AS_STRING(path), PyBytes_AS_STRING(name));
Py_END_ALLOW_THREADS;
Py_DECREF(path);
Py_DECREF(name);
if (err)
return posix_error();
Py_RETURN_NONE;
}
PyDoc_STRVAR(posix_lremovexattr__doc__,
"lremovexattr(path, attr)\n\n\
Like removexattr but don't follow symlinks.");
static PyObject *
posix_lremovexattr(PyObject *self, PyObject *args)
{
PyObject *path, *name;
int err;
if (!PyArg_ParseTuple(args, "O&O&:lremovexattr", PyUnicode_FSConverter, &path,
PyUnicode_FSConverter, &name))
return NULL;
Py_BEGIN_ALLOW_THREADS;
err = lremovexattr(PyBytes_AS_STRING(path), PyBytes_AS_STRING(name));
Py_END_ALLOW_THREADS;
Py_DECREF(path);
Py_DECREF(name);
if (err)
return posix_error();
Py_RETURN_NONE;
}
PyDoc_STRVAR(posix_fremovexattr__doc__,
"fremovexattr(fd, attr)\n\n\
Like removexattr but operates on a file descriptor.");
static PyObject *
posix_fremovexattr(PyObject *self, PyObject *args)
{
PyObject *name;
int fd, err;
if (!PyArg_ParseTuple(args, "iO&:fremovexattr", &fd,
PyUnicode_FSConverter, &name))
return NULL;
Py_BEGIN_ALLOW_THREADS;
err = fremovexattr(fd, PyBytes_AS_STRING(name));
Py_END_ALLOW_THREADS;
Py_DECREF(name);
if (err)
return posix_error();
Py_RETURN_NONE;
}
static Py_ssize_t
try_listxattr(const char *path, ssize_t (*list)(const char *, char *, size_t),
Py_ssize_t buf_size, char **buf)
{
Py_ssize_t len;
*buf = PyMem_MALLOC(buf_size);
if (!*buf) {
PyErr_NoMemory();
return -1;
}
Py_BEGIN_ALLOW_THREADS;
len = list(path, *buf, buf_size);
Py_END_ALLOW_THREADS;
if (len < 0) {
PyMem_FREE(*buf);
if (errno != ERANGE)
posix_error();
return -1;
}
return len;
}
static PyObject *
listxattr_common(const char *path, ssize_t (*list)(const char *, char *, size_t))
{
PyObject *res, *attr;
Py_ssize_t len, err, start, i;
char *buf;
len = try_listxattr(path, list, 256, &buf);
if (len < 0) {
if (PyErr_Occurred())
return NULL;
len = try_listxattr(path, list, XATTR_LIST_MAX, &buf);
if (len < 0)
return NULL;
}
res = PyList_New(0);
if (!res) {
PyMem_FREE(buf);
return NULL;
}
for (start = i = 0; i < len; i++) {
if (!buf[i]) {
attr = PyUnicode_DecodeFSDefaultAndSize(&buf[start], i - start);
if (!attr) {
Py_DECREF(res);
PyMem_FREE(buf);
return NULL;
}
err = PyList_Append(res, attr);
Py_DECREF(attr);
if (err) {
Py_DECREF(res);
PyMem_FREE(buf);
return NULL;
}
start = i + 1;
}
}
PyMem_FREE(buf);
return res;
}
PyDoc_STRVAR(posix_listxattr__doc__,
"listxattr(path)\n\n\
Return a list of extended attributes on *path*.");
static PyObject *
posix_listxattr(PyObject *self, PyObject *args)
{
PyObject *path, *res;
if (!PyArg_ParseTuple(args, "O&:listxattr", PyUnicode_FSConverter, &path))
return NULL;
res = listxattr_common(PyBytes_AS_STRING(path), listxattr);
Py_DECREF(path);
return res;
}
PyDoc_STRVAR(posix_llistxattr__doc__,
"llistxattr(path)\n\n\
Like listxattr but don't follow symlinks..");
static PyObject *
posix_llistxattr(PyObject *self, PyObject *args)
{
PyObject *path, *res;
if (!PyArg_ParseTuple(args, "O&:llistxattr", PyUnicode_FSConverter, &path))
return NULL;
res = listxattr_common(PyBytes_AS_STRING(path), llistxattr);
Py_DECREF(path);
return res;
}
static ssize_t
wrap_flistxattr(const char *path, char *buf, size_t len)
{
/* Hack to share code. */
return flistxattr((int)(Py_uintptr_t)path, buf, len);
}
PyDoc_STRVAR(posix_flistxattr__doc__,
"flistxattr(path)\n\n\
Like flistxattr but operates on a file descriptor.");
static PyObject *
posix_flistxattr(PyObject *self, PyObject *args)
{
long fd;
if (!PyArg_ParseTuple(args, "i:flistxattr", &fd))
return NULL;
return listxattr_common((const char *)(Py_uintptr_t)fd, wrap_flistxattr);
}
#endif /* HAVE_ATTR_XATTR_H */
static PyMethodDef posix_methods[] = {
{"access", posix_access, METH_VARARGS, posix_access__doc__},
#ifdef HAVE_TTYNAME
@ -10398,6 +10780,20 @@ static PyMethodDef posix_methods[] = {
#endif
#ifdef HAVE_MKFIFOAT
{"mkfifoat", posix_mkfifoat, METH_VARARGS, posix_mkfifoat__doc__},
#endif
#ifdef HAVE_ATTR_XATTR_H
{"setxattr", posix_setxattr, METH_VARARGS, posix_setxattr__doc__},
{"lsetxattr", posix_lsetxattr, METH_VARARGS, posix_lsetxattr__doc__},
{"fsetxattr", posix_fsetxattr, METH_VARARGS, posix_fsetxattr__doc__},
{"getxattr", posix_getxattr, METH_VARARGS, posix_getxattr__doc__},
{"lgetxattr", posix_lgetxattr, METH_VARARGS, posix_lgetxattr__doc__},
{"fgetxattr", posix_fgetxattr, METH_VARARGS, posix_fgetxattr__doc__},
{"removexattr", posix_removexattr, METH_VARARGS, posix_removexattr__doc__},
{"lremovexattr", posix_lremovexattr, METH_VARARGS, posix_lremovexattr__doc__},
{"fremovexattr", posix_fremovexattr, METH_VARARGS, posix_fremovexattr__doc__},
{"listxattr", posix_listxattr, METH_VARARGS, posix_listxattr__doc__},
{"llistxattr", posix_llistxattr, METH_VARARGS, posix_llistxattr__doc__},
{"flistxattr", posix_flistxattr, METH_VARARGS, posix_flistxattr__doc__},
#endif
{NULL, NULL} /* Sentinel */
};
@ -10848,6 +11244,12 @@ all_ins(PyObject *d)
#endif
#endif
#ifdef HAVE_ATTR_XATTR_H
if (ins(d, "XATTR_CREATE", (long)XATTR_CREATE)) return -1;
if (ins(d, "XATTR_REPLACE", (long)XATTR_REPLACE)) return -1;
if (ins(d, "XATTR_SIZE_MAX", (long)XATTR_SIZE_MAX)) return -1;
#endif
#if defined(PYOS_OS2)
if (insertvalues(d)) return -1;
#endif