//===--- Implementation of the Linux specialization of File ---------------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// #include "file.h" #include "hdr/stdio_macros.h" #include "hdr/types/off_t.h" #include "src/__support/CPP/new.h" #include "src/__support/File/file.h" #include "src/__support/File/linux/lseekImpl.h" #include "src/__support/OSUtil/fcntl.h" #include "src/__support/OSUtil/syscall.h" // For internal syscall function. #include "src/__support/macros/config.h" #include "src/errno/libc_errno.h" // For error macros #include "hdr/fcntl_macros.h" // For mode_t and other flags to the open syscall #include // For S_IS*, S_IF*, and S_IR* flags. #include // For syscall numbers namespace LIBC_NAMESPACE_DECL { FileIOResult linux_file_write(File *f, const void *data, size_t size) { auto *lf = reinterpret_cast(f); int ret = LIBC_NAMESPACE::syscall_impl(SYS_write, lf->get_fd(), data, size); if (ret < 0) { return {0, -ret}; } return ret; } FileIOResult linux_file_read(File *f, void *buf, size_t size) { auto *lf = reinterpret_cast(f); int ret = LIBC_NAMESPACE::syscall_impl(SYS_read, lf->get_fd(), buf, size); if (ret < 0) { return {0, -ret}; } return ret; } ErrorOr linux_file_seek(File *f, off_t offset, int whence) { auto *lf = reinterpret_cast(f); auto result = internal::lseekimpl(lf->get_fd(), offset, whence); if (!result.has_value()) return result.error(); return result.value(); } int linux_file_close(File *f) { auto *lf = reinterpret_cast(f); int ret = LIBC_NAMESPACE::syscall_impl(SYS_close, lf->get_fd()); if (ret < 0) { return -ret; } delete lf; return 0; } ErrorOr openfile(const char *path, const char *mode) { using ModeFlags = File::ModeFlags; auto modeflags = File::mode_flags(mode); if (modeflags == 0) { // return {nullptr, EINVAL}; return Error(EINVAL); } long open_flags = 0; if (modeflags & ModeFlags(File::OpenMode::APPEND)) { open_flags = O_CREAT | O_APPEND; if (modeflags & ModeFlags(File::OpenMode::PLUS)) open_flags |= O_RDWR; else open_flags |= O_WRONLY; } else if (modeflags & ModeFlags(File::OpenMode::WRITE)) { open_flags = O_CREAT | O_TRUNC; if (modeflags & ModeFlags(File::OpenMode::PLUS)) open_flags |= O_RDWR; else open_flags |= O_WRONLY; } else { if (modeflags & ModeFlags(File::OpenMode::PLUS)) open_flags |= O_RDWR; else open_flags |= O_RDONLY; } // File created will have 0666 permissions. constexpr long OPEN_MODE = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH; #ifdef SYS_open int fd = LIBC_NAMESPACE::syscall_impl(SYS_open, path, open_flags, OPEN_MODE); #elif defined(SYS_openat) int fd = LIBC_NAMESPACE::syscall_impl(SYS_openat, AT_FDCWD, path, open_flags, OPEN_MODE); #else #error "open and openat syscalls not available." #endif if (fd < 0) return Error(-fd); uint8_t *buffer; { AllocChecker ac; buffer = new (ac) uint8_t[File::DEFAULT_BUFFER_SIZE]; if (!ac) return Error(ENOMEM); } AllocChecker ac; auto *file = new (ac) LinuxFile(fd, buffer, File::DEFAULT_BUFFER_SIZE, _IOFBF, true, modeflags); if (!ac) return Error(ENOMEM); return file; } ErrorOr create_file_from_fd(int fd, const char *mode) { using ModeFlags = File::ModeFlags; ModeFlags modeflags = File::mode_flags(mode); if (modeflags == 0) { return Error(EINVAL); } int fd_flags = internal::fcntl(fd, F_GETFL); if (fd_flags == -1) { return Error(EBADF); } using OpenMode = File::OpenMode; if (((fd_flags & O_ACCMODE) == O_RDONLY && !(modeflags & static_cast(OpenMode::READ))) || ((fd_flags & O_ACCMODE) == O_WRONLY && !(modeflags & static_cast(OpenMode::WRITE)))) { return Error(EINVAL); } bool do_seek = false; if ((modeflags & static_cast(OpenMode::APPEND)) && !(fd_flags & O_APPEND)) { do_seek = true; if (internal::fcntl(fd, F_SETFL, reinterpret_cast(fd_flags | O_APPEND)) == -1) { return Error(EBADF); } } uint8_t *buffer; { AllocChecker ac; buffer = new (ac) uint8_t[File::DEFAULT_BUFFER_SIZE]; if (!ac) { return Error(ENOMEM); } } AllocChecker ac; auto *file = new (ac) LinuxFile(fd, buffer, File::DEFAULT_BUFFER_SIZE, _IOFBF, true, modeflags); if (!ac) { return Error(ENOMEM); } if (do_seek) { auto result = file->seek(0, SEEK_END); if (!result.has_value()) { free(file); return Error(result.error()); } } return file; } int get_fileno(File *f) { auto *lf = reinterpret_cast(f); return lf->get_fd(); } } // namespace LIBC_NAMESPACE_DECL