49 lines
1.4 KiB
Rust
49 lines
1.4 KiB
Rust
// SPDX-License-Identifier: MPL-2.0
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use super::SyscallReturn;
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use crate::{
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fs::{
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file_table::FileDesc,
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fs_resolver::{FsPath, AT_FDCWD},
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},
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prelude::*,
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syscall::constants::MAX_FILENAME_LEN,
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};
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pub fn sys_readlinkat(
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dirfd: FileDesc,
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path_addr: Vaddr,
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usr_buf_addr: Vaddr,
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usr_buf_len: usize,
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) -> Result<SyscallReturn> {
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let user_space = CurrentUserSpace::get();
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let path = user_space.read_cstring(path_addr, MAX_FILENAME_LEN)?;
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debug!(
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"dirfd = {}, path = {:?}, usr_buf_addr = 0x{:x}, usr_buf_len = 0x{:x}",
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dirfd, path, usr_buf_addr, usr_buf_len
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);
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let current = current!();
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let dentry = {
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let path = path.to_string_lossy();
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if path.is_empty() {
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return_errno_with_message!(Errno::ENOENT, "path is empty");
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}
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let fs_path = FsPath::new(dirfd, path.as_ref())?;
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current.fs().read().lookup_no_follow(&fs_path)?
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};
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let linkpath = dentry.inode().read_link()?;
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let bytes = linkpath.as_bytes();
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let write_len = bytes.len().min(usr_buf_len);
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user_space.write_bytes(usr_buf_addr, &mut VmReader::from(&bytes[..write_len]))?;
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Ok(SyscallReturn::Return(write_len as _))
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}
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pub fn sys_readlink(
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path_addr: Vaddr,
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usr_buf_addr: Vaddr,
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usr_buf_len: usize,
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) -> Result<SyscallReturn> {
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self::sys_readlinkat(AT_FDCWD, path_addr, usr_buf_addr, usr_buf_len)
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}
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