asterinas/kernel/src/syscall/chmod.rs

92 lines
2.5 KiB
Rust

// SPDX-License-Identifier: MPL-2.0
use super::SyscallReturn;
use crate::{
fs,
fs::{
file_table::{FileDesc, get_file_fast},
path::{AT_FDCWD, FsPath},
utils::{InodeMode, PATH_MAX},
},
prelude::*,
};
pub fn sys_fchmod(fd: FileDesc, mode: u16, ctx: &Context) -> Result<SyscallReturn> {
debug!("fd = {}, mode = 0o{:o}", fd, mode);
let mut file_table = ctx.thread_local.borrow_file_table_mut();
let file = get_file_fast!(&mut file_table, fd);
file.path().set_mode(InodeMode::from_bits_truncate(mode))?;
fs::notify::on_attr_change(file.path());
Ok(SyscallReturn::Return(0))
}
pub fn sys_chmod(path_ptr: Vaddr, mode: u16, ctx: &Context) -> Result<SyscallReturn> {
do_fchmodat(AT_FDCWD, path_ptr, mode, ChmodFlags::empty(), ctx)
}
pub fn sys_fchmodat(
dirfd: FileDesc,
path_ptr: Vaddr,
mode: u16,
ctx: &Context,
) -> Result<SyscallReturn> {
do_fchmodat(dirfd, path_ptr, mode, ChmodFlags::empty(), ctx)
}
pub fn sys_fchmodat2(
dirfd: FileDesc,
path_ptr: Vaddr,
mode: u16,
flags: u32,
ctx: &Context,
) -> Result<SyscallReturn> {
let flags = ChmodFlags::from_bits(flags)
.ok_or_else(|| Error::with_message(Errno::EINVAL, "invalid chmod flags"))?;
do_fchmodat(dirfd, path_ptr, mode, flags, ctx)
}
fn do_fchmodat(
dirfd: FileDesc,
path_ptr: Vaddr,
mode: u16,
flags: ChmodFlags,
ctx: &Context,
) -> Result<SyscallReturn> {
let path_name = ctx.user_space().read_cstring(path_ptr, PATH_MAX)?;
debug!(
"dirfd = {}, path_name = {:?}, mode = 0o{:o}, flags = {:?}",
dirfd, path_name, mode, flags,
);
let path = {
let path_name = path_name.to_string_lossy();
let fs_path = if flags.contains(ChmodFlags::AT_EMPTY_PATH) && path_name.is_empty() {
FsPath::from_fd(dirfd)?
} else {
FsPath::from_fd_and_path(dirfd, &path_name)?
};
let fs_ref = ctx.thread_local.borrow_fs();
let path_resolver = fs_ref.resolver().read();
if flags.contains(ChmodFlags::AT_SYMLINK_NOFOLLOW) {
path_resolver.lookup_no_follow(&fs_path)?
} else {
path_resolver.lookup(&fs_path)?
}
};
path.set_mode(InodeMode::from_bits_truncate(mode))?;
fs::notify::on_attr_change(&path);
Ok(SyscallReturn::Return(0))
}
bitflags::bitflags! {
struct ChmodFlags: u32 {
const AT_EMPTY_PATH = 1 << 12;
const AT_SYMLINK_NOFOLLOW = 1 << 8;
}
}