feat:添加chown系统调用 (#962)

* 添加chown系统调用

---------

Co-authored-by: sparkzky <sparkhhhhhhhhh@outlook.com>
Co-authored-by: longjin <longjin@DragonOS.org>

user/apps/test-chown/src/main.rs

@@ -0,0 +1,160 @@
+use core::ffi::{c_char, c_void};
+use libc::{
+    chown, fchown, fchownat, getgrnam, getpwnam, gid_t, lchown, mount, uid_t, umount, AT_FDCWD,
+    AT_SYMLINK_NOFOLLOW,
+};
+use nix::errno::Errno;
+use std::{
+    ffi::CString,
+    fs::{self, metadata, File},
+    io::{self, Error, Write},
+    os::unix::{
+        fs::{MetadataExt, PermissionsExt},
+        io::AsRawFd,
+    },
+    path::Path,
+};
+
+fn print_file_owner_group(filename: &str) -> Result<(), Error> {
+    let metadata = std::fs::metadata(filename)?;
+    let uid = metadata.uid();
+    let gid = metadata.gid();
+
+    // 确保 UID 和 GID 打印正确
+    assert!(uid > 0, "UID should be greater than 0");
+    assert!(gid > 0, "GID should be greater than 0");
+
+    Ok(())
+}
+
+fn test_fchownat(filename: &str, new_uid: uid_t, new_gid: gid_t, flags: i32) -> Result<(), Error> {
+    let c_filename = CString::new(filename)?;
+    let result = unsafe { fchownat(AT_FDCWD, c_filename.as_ptr(), new_uid, new_gid, flags) };
+
+    // 确保 fchownat 成功
+    assert!(result != -1, "fchownat failed");
+
+    print_file_owner_group(filename)?;
+    Ok(())
+}
+
+fn test_chown(filename: &str, new_uid: uid_t, new_gid: gid_t) -> Result<(), Error> {
+    let c_filename = CString::new(filename)?;
+    let result = unsafe { chown(c_filename.as_ptr(), new_uid, new_gid) };
+
+    // 确保 chown 成功
+    assert!(result != -1, "chown failed");
+
+    print_file_owner_group(filename)?;
+    Ok(())
+}
+
+fn test_fchown(fd: i32, new_uid: uid_t, new_gid: gid_t) -> Result<(), Error> {
+    let result = unsafe { fchown(fd, new_uid, new_gid) };
+
+    // 确保 fchown 成功
+    assert!(result != -1, "fchown failed");
+
+    Ok(())
+}
+
+fn test_lchown(symlink_name: &str, new_uid: uid_t, new_gid: gid_t) -> Result<(), Error> {
+    let c_symlink = CString::new(symlink_name)?;
+    let result = unsafe { lchown(c_symlink.as_ptr(), new_uid, new_gid) };
+
+    // 确保 lchown 成功
+    assert!(result != -1, "lchown failed");
+
+    print_file_owner_group(symlink_name)?;
+    Ok(())
+}
+
+fn main() -> Result<(), Error> {
+    mount_test_ramfs();
+
+    let filename = "/mnt/myramfs/testfile.txt";
+    let symlink_name = "/mnt/myramfs/testsymlink";
+    let new_owner = "nobody"; // 替换为你测试系统中的有效用户名
+    let new_group = "nogroup"; // 替换为你测试系统中的有效组名
+
+    // 获取新的 UID 和 GID
+    let pw = unsafe { getpwnam(CString::new(new_owner)?.as_ptr()) };
+    let gr = unsafe { getgrnam(CString::new(new_group)?.as_ptr()) };
+
+    assert!(!pw.is_null(), "Invalid user name");
+    assert!(!gr.is_null(), "Invalid group name");
+
+    let new_uid = unsafe { (*pw).pw_uid };
+    let new_gid = unsafe { (*gr).gr_gid };
+
+    // 创建测试文件
+    let mut file = File::create(filename)?;
+    println!("Created test file: {}", filename);
+    writeln!(file, "This is a test file for chown system call")?;
+
+    // 创建符号链接
+    std::os::unix::fs::symlink(filename, symlink_name)?;
+    println!("Created symlink: {}", symlink_name);
+
+    // 打开文件以测试 fchown
+    let fd = file.as_raw_fd();
+
+    // 测试 chown
+    test_chown(filename, new_uid, new_gid)?;
+
+    // 测试 fchown
+    test_fchown(fd, new_uid, new_gid)?;
+
+    // 测试 lchown
+    test_lchown(symlink_name, new_uid, new_gid)?;
+
+    // 测试 fchownat，带 AT_SYMLINK_NOFOLLOW 标志（不会跟随符号链接）
+    test_fchownat(symlink_name, new_uid, new_gid, AT_SYMLINK_NOFOLLOW)?;
+
+    // 清理测试文件
+    std::fs::remove_file(filename)?;
+
+    umount_test_ramfs();
+
+    println!("All tests passed!");
+
+    Ok(())
+}
+
+fn mount_test_ramfs() {
+    let path = Path::new("mnt/myramfs");
+    let dir = fs::create_dir_all(path);
+    assert!(dir.is_ok(), "mkdir /mnt/myramfs failed");
+
+    let source = b"\0".as_ptr() as *const c_char;
+    let target = b"/mnt/myramfs\0".as_ptr() as *const c_char;
+    let fstype = b"ramfs\0".as_ptr() as *const c_char;
+    // let flags = MS_BIND;
+    let flags = 0;
+    let data = std::ptr::null() as *const c_void;
+    let result = unsafe { mount(source, target, fstype, flags, data) };
+
+    assert_eq!(
+        result,
+        0,
+        "Mount myramfs failed, errno: {}",
+        Errno::last().desc()
+    );
+    println!("Mount myramfs for test success!");
+}
+
+fn umount_test_ramfs() {
+    let path = b"/mnt/myramfs\0".as_ptr() as *const c_char;
+    let result = unsafe { umount(path) };
+    if result != 0 {
+        let err = Errno::last();
+        println!("Errno: {}", err);
+        println!("Infomation: {}", err.desc());
+    } else {
+        // 删除mnt/myramfs
+        let path = Path::new("mnt/myramfs");
+        let _ = fs::remove_dir(path);
+    }
+    assert_eq!(result, 0, "Umount myramfs failed");
+    println!("Umount myramfs for test success!");
+}