1 use core::ffi::CStr; 2 3 use alloc::{ 4 string::{String, ToString}, 5 sync::Arc, 6 vec::Vec, 7 }; 8 use system_error::SystemError; 9 10 use crate::{ 11 driver::base::{block::SeekFrom, device::device_number::DeviceNumber}, 12 filesystem::vfs::file::FileDescriptorVec, 13 kerror, 14 libs::rwlock::RwLockWriteGuard, 15 mm::{verify_area, VirtAddr}, 16 process::ProcessManager, 17 syscall::{ 18 user_access::{check_and_clone_cstr, UserBufferReader, UserBufferWriter}, 19 Syscall, 20 }, 21 time::TimeSpec, 22 }; 23 24 use super::{ 25 core::{do_mkdir, do_remove_dir, do_unlink_at}, 26 fcntl::{AtFlags, FcntlCommand, FD_CLOEXEC}, 27 file::{File, FileMode}, 28 open::{do_faccessat, do_fchmodat, do_sys_open}, 29 utils::{rsplit_path, user_path_at}, 30 Dirent, FileType, IndexNode, MAX_PATHLEN, ROOT_INODE, VFS_MAX_FOLLOW_SYMLINK_TIMES, 31 }; 32 // use crate::kdebug; 33 34 pub const SEEK_SET: u32 = 0; 35 pub const SEEK_CUR: u32 = 1; 36 pub const SEEK_END: u32 = 2; 37 pub const SEEK_MAX: u32 = 3; 38 39 bitflags! { 40 /// 文件类型和权限 41 #[repr(C)] 42 pub struct ModeType: u32 { 43 /// 掩码 44 const S_IFMT = 0o0_170_000; 45 /// 文件类型 46 const S_IFSOCK = 0o140000; 47 const S_IFLNK = 0o120000; 48 const S_IFREG = 0o100000; 49 const S_IFBLK = 0o060000; 50 const S_IFDIR = 0o040000; 51 const S_IFCHR = 0o020000; 52 const S_IFIFO = 0o010000; 53 54 const S_ISUID = 0o004000; 55 const S_ISGID = 0o002000; 56 const S_ISVTX = 0o001000; 57 /// 文件用户权限 58 const S_IRWXU = 0o0700; 59 const S_IRUSR = 0o0400; 60 const S_IWUSR = 0o0200; 61 const S_IXUSR = 0o0100; 62 /// 文件组权限 63 const S_IRWXG = 0o0070; 64 const S_IRGRP = 0o0040; 65 const S_IWGRP = 0o0020; 66 const S_IXGRP = 0o0010; 67 /// 文件其他用户权限 68 const S_IRWXO = 0o0007; 69 const S_IROTH = 0o0004; 70 const S_IWOTH = 0o0002; 71 const S_IXOTH = 0o0001; 72 73 /// 0o777 74 const S_IRWXUGO = Self::S_IRWXU.bits | Self::S_IRWXG.bits | Self::S_IRWXO.bits; 75 /// 0o7777 76 const S_IALLUGO = Self::S_ISUID.bits | Self::S_ISGID.bits | Self::S_ISVTX.bits| Self::S_IRWXUGO.bits; 77 /// 0o444 78 const S_IRUGO = Self::S_IRUSR.bits | Self::S_IRGRP.bits | Self::S_IROTH.bits; 79 /// 0o222 80 const S_IWUGO = Self::S_IWUSR.bits | Self::S_IWGRP.bits | Self::S_IWOTH.bits; 81 /// 0o111 82 const S_IXUGO = Self::S_IXUSR.bits | Self::S_IXGRP.bits | Self::S_IXOTH.bits; 83 84 85 } 86 } 87 88 #[repr(C)] 89 /// # 文件信息结构体 90 pub struct PosixKstat { 91 /// 硬件设备ID 92 dev_id: u64, 93 /// inode号 94 inode: u64, 95 /// 硬链接数 96 nlink: u64, 97 /// 文件权限 98 mode: ModeType, 99 /// 所有者用户ID 100 uid: i32, 101 /// 所有者组ID 102 gid: i32, 103 /// 设备ID 104 rdev: i64, 105 /// 文件大小 106 size: i64, 107 /// 文件系统块大小 108 blcok_size: i64, 109 /// 分配的512B块数 110 blocks: u64, 111 /// 最后访问时间 112 atime: TimeSpec, 113 /// 最后修改时间 114 mtime: TimeSpec, 115 /// 最后状态变化时间 116 ctime: TimeSpec, 117 /// 用于填充结构体大小的空白数据 118 pub _pad: [i8; 24], 119 } 120 impl PosixKstat { 121 fn new() -> Self { 122 Self { 123 inode: 0, 124 dev_id: 0, 125 mode: ModeType { bits: 0 }, 126 nlink: 0, 127 uid: 0, 128 gid: 0, 129 rdev: 0, 130 size: 0, 131 atime: TimeSpec { 132 tv_sec: 0, 133 tv_nsec: 0, 134 }, 135 mtime: TimeSpec { 136 tv_sec: 0, 137 tv_nsec: 0, 138 }, 139 ctime: TimeSpec { 140 tv_sec: 0, 141 tv_nsec: 0, 142 }, 143 blcok_size: 0, 144 blocks: 0, 145 _pad: Default::default(), 146 } 147 } 148 } 149 150 /// 151 /// Arguments for how openat2(2) should open the target path. If only @flags and 152 /// @mode are non-zero, then openat2(2) operates very similarly to openat(2). 153 /// 154 /// However, unlike openat(2), unknown or invalid bits in @flags result in 155 /// -EINVAL rather than being silently ignored. @mode must be zero unless one of 156 /// {O_CREAT, O_TMPFILE} are set. 157 /// 158 /// ## 成员变量 159 /// 160 /// - flags: O_* flags. 161 /// - mode: O_CREAT/O_TMPFILE file mode. 162 /// - resolve: RESOLVE_* flags. 163 #[derive(Debug, Clone, Copy)] 164 #[repr(C)] 165 pub struct PosixOpenHow { 166 pub flags: u64, 167 pub mode: u64, 168 pub resolve: u64, 169 } 170 171 impl PosixOpenHow { 172 #[allow(dead_code)] 173 pub fn new(flags: u64, mode: u64, resolve: u64) -> Self { 174 Self { 175 flags, 176 mode, 177 resolve, 178 } 179 } 180 } 181 182 #[derive(Debug, Clone, Copy)] 183 pub struct OpenHow { 184 pub o_flags: FileMode, 185 pub mode: ModeType, 186 pub resolve: OpenHowResolve, 187 } 188 189 impl OpenHow { 190 pub fn new(mut o_flags: FileMode, mut mode: ModeType, resolve: OpenHowResolve) -> Self { 191 if !o_flags.contains(FileMode::O_CREAT) { 192 mode = ModeType::empty(); 193 } 194 195 if o_flags.contains(FileMode::O_PATH) { 196 o_flags = o_flags.intersection(FileMode::O_PATH_FLAGS); 197 } 198 199 Self { 200 o_flags, 201 mode, 202 resolve, 203 } 204 } 205 } 206 207 impl From<PosixOpenHow> for OpenHow { 208 fn from(posix_open_how: PosixOpenHow) -> Self { 209 let o_flags = FileMode::from_bits_truncate(posix_open_how.flags as u32); 210 let mode = ModeType::from_bits_truncate(posix_open_how.mode as u32); 211 let resolve = OpenHowResolve::from_bits_truncate(posix_open_how.resolve as u64); 212 return Self::new(o_flags, mode, resolve); 213 } 214 } 215 216 bitflags! { 217 pub struct OpenHowResolve: u64{ 218 /// Block mount-point crossings 219 /// (including bind-mounts). 220 const RESOLVE_NO_XDEV = 0x01; 221 222 /// Block traversal through procfs-style 223 /// "magic-links" 224 const RESOLVE_NO_MAGICLINKS = 0x02; 225 226 /// Block traversal through all symlinks 227 /// (implies OEXT_NO_MAGICLINKS) 228 const RESOLVE_NO_SYMLINKS = 0x04; 229 /// Block "lexical" trickery like 230 /// "..", symlinks, and absolute 231 const RESOLVE_BENEATH = 0x08; 232 /// Make all jumps to "/" and ".." 233 /// be scoped inside the dirfd 234 /// (similar to chroot(2)). 235 const RESOLVE_IN_ROOT = 0x10; 236 // Only complete if resolution can be 237 // completed through cached lookup. May 238 // return -EAGAIN if that's not 239 // possible. 240 const RESOLVE_CACHED = 0x20; 241 } 242 } 243 impl Syscall { 244 /// @brief 为当前进程打开一个文件 245 /// 246 /// @param path 文件路径 247 /// @param o_flags 打开文件的标志位 248 /// 249 /// @return 文件描述符编号，或者是错误码 250 pub fn open( 251 path: &str, 252 flags: FileMode, 253 mode: ModeType, 254 follow_symlink: bool, 255 ) -> Result<usize, SystemError> { 256 return do_sys_open(AtFlags::AT_FDCWD.bits(), path, flags, mode, follow_symlink); 257 } 258 259 pub fn openat( 260 dirfd: i32, 261 path: &str, 262 o_flags: FileMode, 263 mode: ModeType, 264 follow_symlink: bool, 265 ) -> Result<usize, SystemError> { 266 return do_sys_open(dirfd, path, o_flags, mode, follow_symlink); 267 } 268 269 /// @brief 关闭文件 270 /// 271 /// @param fd 文件描述符编号 272 /// 273 /// @return 成功返回0，失败返回错误码 274 pub fn close(fd: usize) -> Result<usize, SystemError> { 275 let binding = ProcessManager::current_pcb().fd_table(); 276 let mut fd_table_guard = binding.write(); 277 278 let res = fd_table_guard.drop_fd(fd as i32).map(|_| 0); 279 280 return res; 281 } 282 283 /// @brief 发送命令到文件描述符对应的设备， 284 /// 285 /// @param fd 文件描述符编号 286 /// @param cmd 设备相关的请求类型 287 /// 288 /// @return Ok(usize) 成功返回0 289 /// @return Err(SystemError) 读取失败，返回posix错误码 290 pub fn ioctl(fd: usize, cmd: u32, data: usize) -> Result<usize, SystemError> { 291 let binding = ProcessManager::current_pcb().fd_table(); 292 let fd_table_guard = binding.read(); 293 294 let file = fd_table_guard 295 .get_file_by_fd(fd as i32) 296 .ok_or(SystemError::EBADF)?; 297 298 // drop guard 以避免无法调度的问题 299 drop(fd_table_guard); 300 let r = file.lock_no_preempt().inode().ioctl(cmd, data); 301 return r; 302 } 303 304 /// @brief 根据文件描述符，读取文件数据。尝试读取的数据长度与buf的长度相同。 305 /// 306 /// @param fd 文件描述符编号 307 /// @param buf 输出缓冲区 308 /// 309 /// @return Ok(usize) 成功读取的数据的字节数 310 /// @return Err(SystemError) 读取失败，返回posix错误码 311 pub fn read(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> { 312 let binding = ProcessManager::current_pcb().fd_table(); 313 let fd_table_guard = binding.read(); 314 315 let file = fd_table_guard.get_file_by_fd(fd); 316 if file.is_none() { 317 return Err(SystemError::EBADF); 318 } 319 // drop guard 以避免无法调度的问题 320 drop(fd_table_guard); 321 let file = file.unwrap(); 322 323 return file.lock_no_preempt().read(buf.len(), buf); 324 } 325 326 /// @brief 根据文件描述符，向文件写入数据。尝试写入的数据长度与buf的长度相同。 327 /// 328 /// @param fd 文件描述符编号 329 /// @param buf 输入缓冲区 330 /// 331 /// @return Ok(usize) 成功写入的数据的字节数 332 /// @return Err(SystemError) 写入失败，返回posix错误码 333 pub fn write(fd: i32, buf: &[u8]) -> Result<usize, SystemError> { 334 let binding = ProcessManager::current_pcb().fd_table(); 335 let fd_table_guard = binding.read(); 336 337 let file = fd_table_guard 338 .get_file_by_fd(fd) 339 .ok_or(SystemError::EBADF)?; 340 341 // drop guard 以避免无法调度的问题 342 drop(fd_table_guard); 343 return file.lock_no_preempt().write(buf.len(), buf); 344 } 345 346 /// @brief 调整文件操作指针的位置 347 /// 348 /// @param fd 文件描述符编号 349 /// @param seek 调整的方式 350 /// 351 /// @return Ok(usize) 调整后，文件访问指针相对于文件头部的偏移量 352 /// @return Err(SystemError) 调整失败，返回posix错误码 353 pub fn lseek(fd: i32, seek: SeekFrom) -> Result<usize, SystemError> { 354 let binding = ProcessManager::current_pcb().fd_table(); 355 let fd_table_guard = binding.read(); 356 let file = fd_table_guard 357 .get_file_by_fd(fd) 358 .ok_or(SystemError::EBADF)?; 359 360 // drop guard 以避免无法调度的问题 361 drop(fd_table_guard); 362 return file.lock_no_preempt().lseek(seek); 363 } 364 365 /// # sys_pread64 系统调用的实际执行函数 366 /// 367 /// ## 参数 368 /// - `fd`: 文件描述符 369 /// - `buf`: 读出缓冲区 370 /// - `len`: 要读取的字节数 371 /// - `offset`: 文件偏移量 372 pub fn pread(fd: i32, buf: &mut [u8], len: usize, offset: usize) -> Result<usize, SystemError> { 373 let binding = ProcessManager::current_pcb().fd_table(); 374 let fd_table_guard = binding.read(); 375 376 let file = fd_table_guard.get_file_by_fd(fd); 377 if file.is_none() { 378 return Err(SystemError::EBADF); 379 } 380 // drop guard 以避免无法调度的问题 381 drop(fd_table_guard); 382 let file = file.unwrap(); 383 384 return file.lock_no_preempt().pread(offset, len, buf); 385 } 386 387 /// # sys_pwrite64 系统调用的实际执行函数 388 /// 389 /// ## 参数 390 /// - `fd`: 文件描述符 391 /// - `buf`: 写入缓冲区 392 /// - `len`: 要写入的字节数 393 /// - `offset`: 文件偏移量 394 pub fn pwrite(fd: i32, buf: &[u8], len: usize, offset: usize) -> Result<usize, SystemError> { 395 let binding = ProcessManager::current_pcb().fd_table(); 396 let fd_table_guard = binding.read(); 397 398 let file = fd_table_guard.get_file_by_fd(fd); 399 if file.is_none() { 400 return Err(SystemError::EBADF); 401 } 402 // drop guard 以避免无法调度的问题 403 drop(fd_table_guard); 404 let file = file.unwrap(); 405 406 return file.lock_no_preempt().pwrite(offset, len, buf); 407 } 408 409 /// @brief 切换工作目录 410 /// 411 /// @param dest_path 目标路径 412 /// 413 /// @return 返回码 描述 414 /// 0 | 成功 415 /// 416 /// EACCESS | 权限不足 417 /// 418 /// ELOOP | 解析path时遇到路径循环 419 /// 420 /// ENAMETOOLONG | 路径名过长 421 /// 422 /// ENOENT | 目标文件或目录不存在 423 /// 424 /// ENODIR | 检索期间发现非目录项 425 /// 426 /// ENOMEM | 系统内存不足 427 /// 428 /// EFAULT | 错误的地址 429 /// 430 /// ENAMETOOLONG | 路径过长 431 pub fn chdir(dest_path: &str) -> Result<usize, SystemError> { 432 let proc = ProcessManager::current_pcb(); 433 // Copy path to kernel space to avoid some security issues 434 let path = dest_path.to_string(); 435 let mut new_path = String::from(""); 436 if path.len() > 0 { 437 let cwd = match path.as_bytes()[0] { 438 b'/' => String::from("/"), 439 _ => proc.basic().cwd(), 440 }; 441 let mut cwd_vec: Vec<_> = cwd.split("/").filter(|&x| x != "").collect(); 442 let path_split = path.split("/").filter(|&x| x != ""); 443 for seg in path_split { 444 if seg == ".." { 445 cwd_vec.pop(); 446 } else if seg == "." { 447 // 当前目录 448 } else { 449 cwd_vec.push(seg); 450 } 451 } 452 //proc.basic().set_path(String::from("")); 453 for seg in cwd_vec { 454 new_path.push_str("/"); 455 new_path.push_str(seg); 456 } 457 if new_path == "" { 458 new_path = String::from("/"); 459 } 460 } 461 let inode = 462 match ROOT_INODE().lookup_follow_symlink(&new_path, VFS_MAX_FOLLOW_SYMLINK_TIMES) { 463 Err(e) => { 464 kerror!("Change Directory Failed, Error = {:?}", e); 465 return Err(SystemError::ENOENT); 466 } 467 Ok(i) => i, 468 }; 469 let metadata = inode.metadata()?; 470 if metadata.file_type == FileType::Dir { 471 proc.basic_mut().set_cwd(String::from(new_path)); 472 return Ok(0); 473 } else { 474 return Err(SystemError::ENOTDIR); 475 } 476 } 477 478 /// @brief 获取当前进程的工作目录路径 479 /// 480 /// @param buf 指向缓冲区的指针 481 /// @param size 缓冲区的大小 482 /// 483 /// @return 成功，返回的指针指向包含工作目录路径的字符串 484 /// @return 错误，没有足够的空间 485 pub fn getcwd(buf: &mut [u8]) -> Result<VirtAddr, SystemError> { 486 let proc = ProcessManager::current_pcb(); 487 let cwd = proc.basic().cwd(); 488 489 let cwd_bytes = cwd.as_bytes(); 490 let cwd_len = cwd_bytes.len(); 491 if cwd_len + 1 > buf.len() { 492 return Err(SystemError::ENOMEM); 493 } 494 buf[..cwd_len].copy_from_slice(cwd_bytes); 495 buf[cwd_len] = 0; 496 497 return Ok(VirtAddr::new(buf.as_ptr() as usize)); 498 } 499 500 /// @brief 获取目录中的数据 501 /// 502 /// TODO: 这个函数的语义与Linux不一致，需要修改！！！ 503 /// 504 /// @param fd 文件描述符号 505 /// @param buf 输出缓冲区 506 /// 507 /// @return 成功返回读取的字节数，失败返回错误码 508 pub fn getdents(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> { 509 let dirent = 510 unsafe { (buf.as_mut_ptr() as *mut Dirent).as_mut() }.ok_or(SystemError::EFAULT)?; 511 512 if fd < 0 || fd as usize > FileDescriptorVec::PROCESS_MAX_FD { 513 return Err(SystemError::EBADF); 514 } 515 516 // 获取fd 517 let binding = ProcessManager::current_pcb().fd_table(); 518 let fd_table_guard = binding.read(); 519 let file = fd_table_guard 520 .get_file_by_fd(fd) 521 .ok_or(SystemError::EBADF)?; 522 523 // drop guard 以避免无法调度的问题 524 drop(fd_table_guard); 525 526 let res = file.lock_no_preempt().readdir(dirent).map(|x| x as usize); 527 528 return res; 529 } 530 531 /// @brief 创建文件夹 532 /// 533 /// @param path(r8) 路径 / mode(r9) 模式 534 /// 535 /// @return uint64_t 负数错误码 / 0表示成功 536 pub fn mkdir(path: &str, mode: usize) -> Result<usize, SystemError> { 537 return do_mkdir(path, FileMode::from_bits_truncate(mode as u32)).map(|x| x as usize); 538 } 539 540 /// **删除文件夹、取消文件的链接、删除文件的系统调用** 541 /// 542 /// ## 参数 543 /// 544 /// - `dirfd`：文件夹的文件描述符.目前暂未实现 545 /// - `pathname`：文件夹的路径 546 /// - `flags`：标志位 547 /// 548 /// 549 pub fn unlinkat(dirfd: i32, pathname: &str, flags: u32) -> Result<usize, SystemError> { 550 let flags = AtFlags::from_bits(flags as i32).ok_or(SystemError::EINVAL)?; 551 552 if flags.contains(AtFlags::AT_REMOVEDIR) { 553 // kdebug!("rmdir"); 554 match do_remove_dir(dirfd, &pathname) { 555 Err(err) => { 556 kerror!("Failed to Remove Directory, Error Code = {:?}", err); 557 return Err(err); 558 } 559 Ok(_) => { 560 return Ok(0); 561 } 562 } 563 } 564 565 match do_unlink_at(dirfd, &pathname) { 566 Err(err) => { 567 kerror!("Failed to Remove Directory, Error Code = {:?}", err); 568 return Err(err); 569 } 570 Ok(_) => { 571 return Ok(0); 572 } 573 } 574 } 575 576 pub fn unlink(pathname: *const u8) -> Result<usize, SystemError> { 577 if pathname.is_null() { 578 return Err(SystemError::EFAULT); 579 } 580 let ureader = UserBufferReader::new(pathname, MAX_PATHLEN, true)?; 581 582 let buf: &[u8] = ureader.buffer(0).unwrap(); 583 584 let pathname: &CStr = CStr::from_bytes_until_nul(buf).map_err(|_| SystemError::EINVAL)?; 585 586 let pathname: &str = pathname.to_str().map_err(|_| SystemError::EINVAL)?; 587 if pathname.len() >= MAX_PATHLEN { 588 return Err(SystemError::ENAMETOOLONG); 589 } 590 let pathname = pathname.trim(); 591 592 return do_unlink_at(AtFlags::AT_FDCWD.bits(), pathname).map(|v| v as usize); 593 } 594 595 /// @brief 根据提供的文件描述符的fd，复制对应的文件结构体，并返回新复制的文件结构体对应的fd 596 pub fn dup(oldfd: i32) -> Result<usize, SystemError> { 597 let binding = ProcessManager::current_pcb().fd_table(); 598 let mut fd_table_guard = binding.write(); 599 600 let old_file = fd_table_guard 601 .get_file_by_fd(oldfd) 602 .ok_or(SystemError::EBADF)?; 603 604 let new_file = old_file 605 .lock_no_preempt() 606 .try_clone() 607 .ok_or(SystemError::EBADF)?; 608 // 申请文件描述符，并把文件对象存入其中 609 let res = fd_table_guard.alloc_fd(new_file, None).map(|x| x as usize); 610 return res; 611 } 612 613 /// 根据提供的文件描述符的fd，和指定新fd，复制对应的文件结构体， 614 /// 并返回新复制的文件结构体对应的fd. 615 /// 如果新fd已经打开，则会先关闭新fd. 616 /// 617 /// ## 参数 618 /// 619 /// - `oldfd`：旧文件描述符 620 /// - `newfd`：新文件描述符 621 /// 622 /// ## 返回值 623 /// 624 /// - 成功：新文件描述符 625 /// - 失败：错误码 626 pub fn dup2(oldfd: i32, newfd: i32) -> Result<usize, SystemError> { 627 let binding = ProcessManager::current_pcb().fd_table(); 628 let mut fd_table_guard = binding.write(); 629 return Self::do_dup2(oldfd, newfd, &mut fd_table_guard); 630 } 631 632 fn do_dup2( 633 oldfd: i32, 634 newfd: i32, 635 fd_table_guard: &mut RwLockWriteGuard<'_, FileDescriptorVec>, 636 ) -> Result<usize, SystemError> { 637 // 确认oldfd, newid是否有效 638 if !(FileDescriptorVec::validate_fd(oldfd) && FileDescriptorVec::validate_fd(newfd)) { 639 return Err(SystemError::EBADF); 640 } 641 642 if oldfd == newfd { 643 // 若oldfd与newfd相等 644 return Ok(newfd as usize); 645 } 646 let new_exists = fd_table_guard.get_file_by_fd(newfd).is_some(); 647 if new_exists { 648 // close newfd 649 if let Err(_) = fd_table_guard.drop_fd(newfd) { 650 // An I/O error occurred while attempting to close fildes2. 651 return Err(SystemError::EIO); 652 } 653 } 654 655 let old_file = fd_table_guard 656 .get_file_by_fd(oldfd) 657 .ok_or(SystemError::EBADF)?; 658 let new_file = old_file 659 .lock_no_preempt() 660 .try_clone() 661 .ok_or(SystemError::EBADF)?; 662 // 申请文件描述符，并把文件对象存入其中 663 let res = fd_table_guard 664 .alloc_fd(new_file, Some(newfd)) 665 .map(|x| x as usize); 666 return res; 667 } 668 669 /// # fcntl 670 /// 671 /// ## 参数 672 /// 673 /// - `fd`：文件描述符 674 /// - `cmd`：命令 675 /// - `arg`：参数 676 pub fn fcntl(fd: i32, cmd: FcntlCommand, arg: i32) -> Result<usize, SystemError> { 677 match cmd { 678 FcntlCommand::DupFd => { 679 if arg < 0 || arg as usize >= FileDescriptorVec::PROCESS_MAX_FD { 680 return Err(SystemError::EBADF); 681 } 682 let arg = arg as usize; 683 for i in arg..FileDescriptorVec::PROCESS_MAX_FD { 684 let binding = ProcessManager::current_pcb().fd_table(); 685 let mut fd_table_guard = binding.write(); 686 if fd_table_guard.get_file_by_fd(fd).is_none() { 687 return Self::do_dup2(fd, i as i32, &mut fd_table_guard); 688 } 689 } 690 return Err(SystemError::EMFILE); 691 } 692 FcntlCommand::GetFd => { 693 // Get file descriptor flags. 694 let binding = ProcessManager::current_pcb().fd_table(); 695 let fd_table_guard = binding.read(); 696 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 697 // drop guard 以避免无法调度的问题 698 drop(fd_table_guard); 699 700 if file.lock().close_on_exec() { 701 return Ok(FD_CLOEXEC as usize); 702 } 703 } 704 return Err(SystemError::EBADF); 705 } 706 FcntlCommand::SetFd => { 707 // Set file descriptor flags. 708 let binding = ProcessManager::current_pcb().fd_table(); 709 let fd_table_guard = binding.write(); 710 711 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 712 // drop guard 以避免无法调度的问题 713 drop(fd_table_guard); 714 let arg = arg as u32; 715 if arg & FD_CLOEXEC != 0 { 716 file.lock().set_close_on_exec(true); 717 } else { 718 file.lock().set_close_on_exec(false); 719 } 720 return Ok(0); 721 } 722 return Err(SystemError::EBADF); 723 } 724 725 FcntlCommand::GetFlags => { 726 // Get file status flags. 727 let binding = ProcessManager::current_pcb().fd_table(); 728 let fd_table_guard = binding.read(); 729 730 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 731 // drop guard 以避免无法调度的问题 732 drop(fd_table_guard); 733 return Ok(file.lock_no_preempt().mode().bits() as usize); 734 } 735 736 return Err(SystemError::EBADF); 737 } 738 FcntlCommand::SetFlags => { 739 // Set file status flags. 740 let binding = ProcessManager::current_pcb().fd_table(); 741 let fd_table_guard = binding.write(); 742 743 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 744 let arg = arg as u32; 745 let mode = FileMode::from_bits(arg).ok_or(SystemError::EINVAL)?; 746 // drop guard 以避免无法调度的问题 747 drop(fd_table_guard); 748 file.lock_no_preempt().set_mode(mode)?; 749 return Ok(0); 750 } 751 752 return Err(SystemError::EBADF); 753 } 754 _ => { 755 // TODO: unimplemented 756 // 未实现的命令，返回0，不报错。 757 758 // kwarn!("fcntl: unimplemented command: {:?}, defaults to 0.", cmd); 759 return Ok(0); 760 } 761 } 762 } 763 764 /// # ftruncate 765 /// 766 /// ## 描述 767 /// 768 /// 改变文件大小. 769 /// 如果文件大小大于原来的大小，那么文件的内容将会被扩展到指定的大小，新的空间将会用0填充. 770 /// 如果文件大小小于原来的大小，那么文件的内容将会被截断到指定的大小. 771 /// 772 /// ## 参数 773 /// 774 /// - `fd`：文件描述符 775 /// - `len`：文件大小 776 /// 777 /// ## 返回值 778 /// 779 /// 如果成功，返回0，否则返回错误码. 780 pub fn ftruncate(fd: i32, len: usize) -> Result<usize, SystemError> { 781 let binding = ProcessManager::current_pcb().fd_table(); 782 let fd_table_guard = binding.read(); 783 784 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 785 // drop guard 以避免无法调度的问题 786 drop(fd_table_guard); 787 let r = file.lock_no_preempt().ftruncate(len).map(|_| 0); 788 return r; 789 } 790 791 return Err(SystemError::EBADF); 792 } 793 794 fn do_fstat(fd: i32) -> Result<PosixKstat, SystemError> { 795 let binding = ProcessManager::current_pcb().fd_table(); 796 let fd_table_guard = binding.read(); 797 let file = fd_table_guard 798 .get_file_by_fd(fd) 799 .ok_or(SystemError::EBADF)?; 800 // drop guard 以避免无法调度的问题 801 drop(fd_table_guard); 802 803 let mut kstat = PosixKstat::new(); 804 // 获取文件信息 805 let metadata = file.lock().metadata()?; 806 kstat.size = metadata.size as i64; 807 kstat.dev_id = metadata.dev_id as u64; 808 kstat.inode = metadata.inode_id.into() as u64; 809 kstat.blcok_size = metadata.blk_size as i64; 810 kstat.blocks = metadata.blocks as u64; 811 812 kstat.atime.tv_sec = metadata.atime.tv_sec; 813 kstat.atime.tv_nsec = metadata.atime.tv_nsec; 814 kstat.mtime.tv_sec = metadata.mtime.tv_sec; 815 kstat.mtime.tv_nsec = metadata.mtime.tv_nsec; 816 kstat.ctime.tv_sec = metadata.ctime.tv_sec; 817 kstat.ctime.tv_nsec = metadata.ctime.tv_nsec; 818 819 kstat.nlink = metadata.nlinks as u64; 820 kstat.uid = metadata.uid as i32; 821 kstat.gid = metadata.gid as i32; 822 kstat.rdev = metadata.raw_dev.data() as i64; 823 kstat.mode = metadata.mode; 824 match file.lock().file_type() { 825 FileType::File => kstat.mode.insert(ModeType::S_IFREG), 826 FileType::Dir => kstat.mode.insert(ModeType::S_IFDIR), 827 FileType::BlockDevice => kstat.mode.insert(ModeType::S_IFBLK), 828 FileType::CharDevice => kstat.mode.insert(ModeType::S_IFCHR), 829 FileType::SymLink => kstat.mode.insert(ModeType::S_IFLNK), 830 FileType::Socket => kstat.mode.insert(ModeType::S_IFSOCK), 831 FileType::Pipe => kstat.mode.insert(ModeType::S_IFIFO), 832 FileType::KvmDevice => kstat.mode.insert(ModeType::S_IFCHR), 833 FileType::FramebufferDevice => kstat.mode.insert(ModeType::S_IFCHR), 834 } 835 836 return Ok(kstat); 837 } 838 839 pub fn fstat(fd: i32, usr_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 840 let kstat = Self::do_fstat(fd)?; 841 if usr_kstat.is_null() { 842 return Err(SystemError::EFAULT); 843 } 844 unsafe { 845 *usr_kstat = kstat; 846 } 847 return Ok(0); 848 } 849 850 pub fn stat(path: &str, user_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 851 let fd = Self::open(path, FileMode::O_RDONLY, ModeType::empty(), true)?; 852 let r = Self::fstat(fd as i32, user_kstat); 853 Self::close(fd).ok(); 854 return r; 855 } 856 857 pub fn lstat(path: &str, user_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 858 let fd = Self::open(path, FileMode::O_RDONLY, ModeType::empty(), false)?; 859 let r = Self::fstat(fd as i32, user_kstat); 860 Self::close(fd).ok(); 861 return r; 862 } 863 864 pub fn mknod( 865 path_ptr: *const i8, 866 mode: ModeType, 867 dev_t: DeviceNumber, 868 ) -> Result<usize, SystemError> { 869 // 安全检验 870 let len = unsafe { CStr::from_ptr(path_ptr).to_bytes().len() }; 871 let user_buffer = UserBufferReader::new(path_ptr, len, true)?; 872 let buf = user_buffer.read_from_user::<u8>(0)?; 873 let path = core::str::from_utf8(buf).map_err(|_| SystemError::EINVAL)?; 874 875 // 文件名过长 876 if path.len() > MAX_PATHLEN as usize { 877 return Err(SystemError::ENAMETOOLONG); 878 } 879 880 let inode: Result<Arc<dyn IndexNode>, SystemError> = 881 ROOT_INODE().lookup_follow_symlink(path, VFS_MAX_FOLLOW_SYMLINK_TIMES); 882 883 if inode.is_ok() { 884 return Err(SystemError::EEXIST); 885 } 886 887 let (filename, parent_path) = rsplit_path(path); 888 889 // 查找父目录 890 let parent_inode: Arc<dyn IndexNode> = ROOT_INODE() 891 .lookup_follow_symlink(parent_path.unwrap_or("/"), VFS_MAX_FOLLOW_SYMLINK_TIMES)?; 892 // 创建nod 893 parent_inode.mknod(filename, mode, dev_t)?; 894 895 return Ok(0); 896 } 897 898 pub fn writev(fd: i32, iov: usize, count: usize) -> Result<usize, SystemError> { 899 // IoVecs会进行用户态检验 900 let iovecs = unsafe { IoVecs::from_user(iov as *const IoVec, count, false) }?; 901 902 let data = iovecs.gather(); 903 904 Self::write(fd, &data) 905 } 906 907 pub fn readv(fd: i32, iov: usize, count: usize) -> Result<usize, SystemError> { 908 // IoVecs会进行用户态检验 909 let mut iovecs = unsafe { IoVecs::from_user(iov as *const IoVec, count, true) }?; 910 911 let mut data = Vec::new(); 912 data.resize(iovecs.0.iter().map(|x| x.len()).sum(), 0); 913 914 let len = Self::read(fd, &mut data)?; 915 916 iovecs.scatter(&data[..len]); 917 918 return Ok(len); 919 } 920 921 pub fn readlink_at( 922 dirfd: i32, 923 path: *const u8, 924 user_buf: *mut u8, 925 buf_size: usize, 926 ) -> Result<usize, SystemError> { 927 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 928 let mut user_buf = UserBufferWriter::new(user_buf, buf_size, true)?; 929 930 if path.len() == 0 { 931 return Err(SystemError::EINVAL); 932 } 933 934 let (inode, path) = user_path_at(&ProcessManager::current_pcb(), dirfd, &path)?; 935 936 let inode = inode.lookup(path.as_str())?; 937 if inode.metadata()?.file_type != FileType::SymLink { 938 return Err(SystemError::EINVAL); 939 } 940 941 let ubuf = user_buf.buffer::<u8>(0).unwrap(); 942 943 let mut file = File::new(inode, FileMode::O_RDONLY)?; 944 945 let len = file.read(buf_size, ubuf)?; 946 947 return Ok(len); 948 } 949 950 pub fn readlink( 951 path: *const u8, 952 user_buf: *mut u8, 953 buf_size: usize, 954 ) -> Result<usize, SystemError> { 955 return Self::readlink_at(AtFlags::AT_FDCWD.bits(), path, user_buf, buf_size); 956 } 957 958 pub fn access(pathname: *const u8, mode: u32) -> Result<usize, SystemError> { 959 return do_faccessat( 960 AtFlags::AT_FDCWD.bits(), 961 pathname, 962 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 963 0, 964 ); 965 } 966 967 pub fn faccessat2( 968 dirfd: i32, 969 pathname: *const u8, 970 mode: u32, 971 flags: u32, 972 ) -> Result<usize, SystemError> { 973 return do_faccessat( 974 dirfd, 975 pathname, 976 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 977 flags, 978 ); 979 } 980 981 pub fn chmod(pathname: *const u8, mode: u32) -> Result<usize, SystemError> { 982 return do_fchmodat( 983 AtFlags::AT_FDCWD.bits(), 984 pathname, 985 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 986 ); 987 } 988 989 pub fn fchmodat(dirfd: i32, pathname: *const u8, mode: u32) -> Result<usize, SystemError> { 990 return do_fchmodat( 991 dirfd, 992 pathname, 993 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 994 ); 995 } 996 997 pub fn fchmod(fd: i32, mode: u32) -> Result<usize, SystemError> { 998 let _mode = ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?; 999 let binding = ProcessManager::current_pcb().fd_table(); 1000 let fd_table_guard = binding.read(); 1001 let _file = fd_table_guard 1002 .get_file_by_fd(fd) 1003 .ok_or(SystemError::EBADF)?; 1004 1005 // fchmod没完全实现，因此不修改文件的权限 1006 // todo: 实现fchmod 1007 kwarn!("fchmod not fully implemented"); 1008 return Ok(0); 1009 } 1010 } 1011 1012 #[repr(C)] 1013 #[derive(Debug, Clone, Copy)] 1014 pub struct IoVec { 1015 /// 缓冲区的起始地址 1016 pub iov_base: *mut u8, 1017 /// 缓冲区的长度 1018 pub iov_len: usize, 1019 } 1020 1021 /// 用于存储多个来自用户空间的IoVec 1022 /// 1023 /// 由于目前内核中的文件系统还不支持分散读写，所以暂时只支持将用户空间的IoVec聚合成一个缓冲区，然后进行操作。 1024 /// TODO：支持分散读写 1025 #[derive(Debug)] 1026 pub struct IoVecs(Vec<&'static mut [u8]>); 1027 1028 impl IoVecs { 1029 /// 从用户空间的IoVec中构造IoVecs 1030 /// 1031 /// @param iov 用户空间的IoVec 1032 /// @param iovcnt 用户空间的IoVec的数量 1033 /// @param readv 是否为readv系统调用 1034 /// 1035 /// @return 构造成功返回IoVecs，否则返回错误码 1036 pub unsafe fn from_user( 1037 iov: *const IoVec, 1038 iovcnt: usize, 1039 _readv: bool, 1040 ) -> Result<Self, SystemError> { 1041 // 检查iov指针所在空间是否合法 1042 verify_area( 1043 VirtAddr::new(iov as usize), 1044 iovcnt * core::mem::size_of::<IoVec>(), 1045 ) 1046 .map_err(|_| SystemError::EFAULT)?; 1047 1048 // 将用户空间的IoVec转换为引用（注意：这里的引用是静态的，因为用户空间的IoVec不会被释放） 1049 let iovs: &[IoVec] = core::slice::from_raw_parts(iov, iovcnt); 1050 1051 let mut slices: Vec<&mut [u8]> = vec![]; 1052 slices.reserve(iovs.len()); 1053 1054 for iov in iovs.iter() { 1055 if iov.iov_len == 0 { 1056 continue; 1057 } 1058 1059 verify_area( 1060 VirtAddr::new(iov.iov_base as usize), 1061 iovcnt * core::mem::size_of::<IoVec>(), 1062 ) 1063 .map_err(|_| SystemError::EFAULT)?; 1064 1065 slices.push(core::slice::from_raw_parts_mut(iov.iov_base, iov.iov_len)); 1066 } 1067 1068 return Ok(Self(slices)); 1069 } 1070 1071 /// @brief 将IoVecs中的数据聚合到一个缓冲区中 1072 /// 1073 /// @return 返回聚合后的缓冲区 1074 pub fn gather(&self) -> Vec<u8> { 1075 let mut buf = Vec::new(); 1076 for slice in self.0.iter() { 1077 buf.extend_from_slice(slice); 1078 } 1079 return buf; 1080 } 1081 1082 /// @brief 将给定的数据分散写入到IoVecs中 1083 pub fn scatter(&mut self, data: &[u8]) { 1084 let mut data: &[u8] = data; 1085 for slice in self.0.iter_mut() { 1086 let len = core::cmp::min(slice.len(), data.len()); 1087 if len == 0 { 1088 continue; 1089 } 1090 1091 slice[..len].copy_from_slice(&data[..len]); 1092 data = &data[len..]; 1093 } 1094 } 1095 1096 /// @brief 创建与IoVecs等长的缓冲区 1097 /// 1098 /// @param set_len 是否设置返回的Vec的len。 1099 /// 如果为true，则返回的Vec的len为所有IoVec的长度之和; 1100 /// 否则返回的Vec的len为0，capacity为所有IoVec的长度之和. 1101 /// 1102 /// @return 返回创建的缓冲区 1103 pub fn new_buf(&self, set_len: bool) -> Vec<u8> { 1104 let total_len: usize = self.0.iter().map(|slice| slice.len()).sum(); 1105 let mut buf: Vec<u8> = Vec::with_capacity(total_len); 1106 1107 if set_len { 1108 buf.resize(total_len, 0); 1109 } 1110 return buf; 1111 } 1112 } 1113