use std::io;
use std::ffi::{CString, OsStr, OsString};
use std::os::unix::io::RawFd;
use std::os::unix::ffi::{OsStrExt, OsStringExt};
use std::path::Path;
use std::mem;
use libc::{c_char, ssize_t, size_t, c_int, c_void, EPERM};
use util::{path_to_c, allocate_loop};
const EXTATTR_NAMESPACE_USER_STRING: &'static str = "user";
const EXTATTR_NAMESPACE_SYSTEM_STRING: &'static str = "system";
const EXTATTR_NAMESPACE_NAMES: [&'static str; 3] =
["empty", EXTATTR_NAMESPACE_USER_STRING, EXTATTR_NAMESPACE_SYSTEM_STRING];
const EXTATTR_NAMESPACE_USER: c_int = 1;
const EXTATTR_NAMESPACE_SYSTEM: c_int = 2;
extern "C" {
pub fn extattr_list_fd(fd: c_int,
attrnamespace: c_int,
data: *mut c_void,
nbytes: size_t)
-> ssize_t;
pub fn extattr_get_fd(fd: c_int,
attrnamespace: c_int,
attrname: *const c_char,
data: *mut c_void,
nbytes: size_t)
-> ssize_t;
pub fn extattr_delete_fd(fd: c_int, attrname: c_int, attrname: *const c_char) -> c_int;
pub fn extattr_set_fd(fd: c_int,
attrname: c_int,
attrname: *const c_char,
data: *const c_void,
nbytes: size_t)
-> ssize_t;
pub fn extattr_list_link(path: *const c_char,
attrnamespace: c_int,
data: *mut c_void,
nbytes: size_t)
-> ssize_t;
pub fn extattr_get_link(path: *const c_char,
attrnamespace: c_int,
attrname: *const c_char,
data: *mut c_void,
nbytes: size_t)
-> ssize_t;
pub fn extattr_delete_link(path: *const c_char,
attrname: c_int,
attrname: *const c_char)
-> c_int;
pub fn extattr_set_link(path: *const c_char,
attrname: c_int,
attrname: *const c_char,
data: *const c_void,
nbytes: size_t)
-> ssize_t;
}
pub struct XAttrs {
user_attrs: Box<[u8]>,
system_attrs: Box<[u8]>,
offset: usize,
}
impl Clone for XAttrs {
fn clone(&self) -> Self {
XAttrs {
user_attrs: Vec::from(&*self.user_attrs).into_boxed_slice(),
system_attrs: Vec::from(&*self.system_attrs).into_boxed_slice(),
offset: self.offset,
}
}
fn clone_from(&mut self, other: &XAttrs) {
self.offset = other.offset;
let mut data = mem::replace(&mut self.user_attrs, Box::new([])).into_vec();
data.extend(other.user_attrs.iter().cloned());
self.user_attrs = data.into_boxed_slice();
data = mem::replace(&mut self.system_attrs, Box::new([])).into_vec();
data.extend(other.system_attrs.iter().cloned());
self.system_attrs = data.into_boxed_slice();
}
}
impl Iterator for XAttrs {
type Item = OsString;
fn next(&mut self) -> Option<OsString> {
if self.user_attrs.is_empty() && self.system_attrs.is_empty() {
return None;
}
if self.offset == self.user_attrs.len() + self.system_attrs.len() {
return None;
}
let data = if self.offset < self.system_attrs.len() {
&self.system_attrs[self.offset..]
} else {
&self.user_attrs[self.offset - self.system_attrs.len()..]
};
let siz = data[0] as usize;
self.offset += siz + 1;
if self.offset < self.system_attrs.len() {
Some(prefix_namespace(OsStr::from_bytes(&data[1..siz + 1]),
EXTATTR_NAMESPACE_SYSTEM))
} else {
Some(prefix_namespace(OsStr::from_bytes(&data[1..siz + 1]), EXTATTR_NAMESPACE_USER))
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
if self.user_attrs.len() + self.system_attrs.len() == self.offset {
(0, Some(0))
} else {
(1, None)
}
}
}
fn name_to_ns(name: &OsStr) -> io::Result<(c_int, CString)> {
let mut groups = name.as_bytes().splitn(2, |&b| b == b'.').take(2);
let nsname = match groups.next() {
Some(s) => s,
None => return Err(io::Error::new(io::ErrorKind::InvalidInput, "couldn't find namespace")),
};
let propname = match groups.next() {
Some(s) => s,
None => return Err(io::Error::new(io::ErrorKind::InvalidInput, "couldn't find attribute")),
};
let ns_int = match EXTATTR_NAMESPACE_NAMES.iter().position(|&s| s.as_bytes() == nsname) {
Some(i) => i,
None => return Err(io::Error::new(io::ErrorKind::InvalidInput, "no matching namespace")),
};
Ok((ns_int as c_int, try!(CString::new(propname))))
}
fn prefix_namespace(attr: &OsStr, ns: c_int) -> OsString {
let nsname = EXTATTR_NAMESPACE_NAMES[ns as usize];
let mut v = Vec::with_capacity(nsname.as_bytes().len() + attr.as_bytes().len() + 1);
v.extend(nsname.as_bytes());
v.extend(".".as_bytes());
v.extend(attr.as_bytes());
OsString::from_vec(v)
}
pub fn get_fd(fd: RawFd, name: &OsStr) -> io::Result<Vec<u8>> {
let (ns, name) = try!(name_to_ns(name));
unsafe {
allocate_loop(|buf, len| {
extattr_get_fd(fd, ns, name.as_ptr(), buf as *mut c_void, len as size_t)
})
}
}
pub fn set_fd(fd: RawFd, name: &OsStr, value: &[u8]) -> io::Result<()> {
let (ns, name) = try!(name_to_ns(name));
let ret = unsafe {
extattr_set_fd(fd,
ns,
name.as_ptr(),
value.as_ptr() as *const c_void,
value.len() as size_t)
};
if ret == -1 {
Err(io::Error::last_os_error())
} else {
Ok(())
}
}
pub fn remove_fd(fd: RawFd, name: &OsStr) -> io::Result<()> {
let (ns, name) = try!(name_to_ns(name));
let ret = unsafe { extattr_delete_fd(fd, ns, name.as_ptr()) };
if ret != 0 {
Err(io::Error::last_os_error())
} else {
Ok(())
}
}
pub fn list_fd(fd: RawFd) -> io::Result<XAttrs> {
let sysvec = unsafe {
let res = allocate_loop(|buf, len| {
extattr_list_fd(fd,
EXTATTR_NAMESPACE_SYSTEM,
buf as *mut c_void,
len as size_t)
});
match res {
Ok(v) => v,
Err(err) => {
if err.raw_os_error() == Some(EPERM) {
Vec::new()
} else {
return Err(err);
}
}
}
};
let uservec = unsafe {
let res = allocate_loop(|buf, len| {
extattr_list_fd(fd,
EXTATTR_NAMESPACE_USER,
buf as *mut c_void,
len as size_t)
});
match res {
Ok(v) => v,
Err(err) => return Err(err),
}
};
Ok(XAttrs {
system_attrs: sysvec.into_boxed_slice(),
user_attrs: uservec.into_boxed_slice(),
offset: 0,
})
}
pub fn get_path(path: &Path, name: &OsStr) -> io::Result<Vec<u8>> {
let (ns, name) = try!(name_to_ns(name));
let path = try!(path_to_c(path));
unsafe {
allocate_loop(|buf, len| {
extattr_get_link(path.as_ptr(),
ns,
name.as_ptr(),
buf as *mut c_void,
len as size_t)
})
}
}
pub fn set_path(path: &Path, name: &OsStr, value: &[u8]) -> io::Result<()> {
let (ns, name) = try!(name_to_ns(name));
let path = try!(path_to_c(path));
let ret = unsafe {
extattr_set_link(path.as_ptr(),
ns,
name.as_ptr(),
value.as_ptr() as *const c_void,
value.len() as size_t)
};
if ret == -1 {
Err(io::Error::last_os_error())
} else {
Ok(())
}
}
pub fn remove_path(path: &Path, name: &OsStr) -> io::Result<()> {
let (ns, name) = try!(name_to_ns(name));
let path = try!(path_to_c(path));
let ret = unsafe { extattr_delete_link(path.as_ptr(), ns, name.as_ptr()) };
if ret != 0 {
Err(io::Error::last_os_error())
} else {
Ok(())
}
}
pub fn list_path(path: &Path) -> io::Result<XAttrs> {
let path = try!(path_to_c(path));
let sysvec = unsafe {
let res = allocate_loop(|buf, len| {
extattr_list_link(path.as_ptr(),
EXTATTR_NAMESPACE_SYSTEM,
buf as *mut c_void,
len as size_t)
});
match res {
Ok(v) => v,
Err(err) => {
if err.raw_os_error() == Some(EPERM) {
Vec::new()
} else {
return Err(err);
}
}
}
};
let uservec = unsafe {
let res = allocate_loop(|buf, len| {
extattr_list_link(path.as_ptr(),
EXTATTR_NAMESPACE_USER,
buf as *mut c_void,
len as size_t)
});
match res {
Ok(v) => v,
Err(err) => return Err(err),
}
};
Ok(XAttrs {
system_attrs: sysvec.into_boxed_slice(),
user_attrs: uservec.into_boxed_slice(),
offset: 0,
})
}