实现系统调用Fstat (#295)

* fstat

* 修改syscall.rs中的verify_area

.vscode/c_cpp_properties.json

@@ -4,6 +4,7 @@
             "name": "DragonOS",
             "includePath": [
                 "${workspaceFolder}/**",
+                "${workspaceFolder}/bin/sysroot/usr/include",
                 "${workspaceFolder}/user/libs/libc/src/include",
                 "${workspaceFolder}/user/libs/libc/src/include/export"
             ],

kernel/src/filesystem/mod.rs

@@ -5,3 +5,4 @@ pub mod procfs;
 pub mod ramfs;
 pub mod sysfs;
 pub mod vfs;
+pub mod syscall;

kernel/src/filesystem/syscall.rs

@@ -0,0 +1,167 @@
+use crate::{
+    arch::asm::current::current_pcb,
+    filesystem::vfs::FileType,
+    kdebug,
+    syscall::{Syscall, SystemError},
+    time::TimeSpec,
+};
+
+bitflags! {
+    /// 文件类型和权限
+    pub struct ModeType: u32 {
+        /// 掩码
+        const S_IFMT = 0o0_170_000;
+        /// 文件类型
+        const S_IFSOCK = 0o140000;
+        const S_IFLNK = 0o120000;
+        const S_IFREG = 0o100000;
+        const S_IFBLK = 0o060000;
+        const S_IFDIR = 0o040000;
+        const S_IFCHR = 0o020000;
+        const S_IFIFO = 0o010000;
+
+        const S_ISUID = 0o004000;
+        const S_ISGID = 0o002000;
+        const S_ISVTX = 0o001000;
+        /// 文件用户权限
+        const S_IRWXU = 0o0700;
+        const S_IRUSR = 0o0400;
+        const S_IWUSR = 0o0200;
+        const S_IXUSR = 0o0100;
+        /// 文件组权限
+        const S_IRWXG = 0o0070;
+        const S_IRGRP = 0o0040;
+        const S_IWGRP = 0o0020;
+        const S_IXGRP = 0o0010;
+        /// 文件其他用户权限
+        const S_IRWXO = 0o0007;
+        const S_IROTH = 0o0004;
+        const S_IWOTH = 0o0002;
+        const S_IXOTH = 0o0001;
+    }
+}
+
+#[repr(C)]
+/// # 文件信息结构体
+pub struct PosixKstat {
+    /// 硬件设备ID
+    dev_id: u64,
+    /// inode号
+    inode: u64,
+    /// 硬链接数
+    nlink: u64,
+    /// 文件权限
+    mode: ModeType,
+    /// 所有者用户ID
+    uid: i32,
+    /// 所有者组ID
+    gid: i32,
+    /// 设备ID
+    rdev: i64,
+    /// 文件大小
+    size: i64,
+    /// 文件系统块大小
+    blcok_size: i64,
+    /// 分配的512B块数
+    blocks: u64,
+    /// 最后访问时间
+    atime: TimeSpec,
+    /// 最后修改时间
+    mtime: TimeSpec,
+    /// 最后状态变化时间
+    ctime: TimeSpec,
+    /// 用于填充结构体大小的空白数据
+    pub _pad: [i8; 24],
+}
+impl PosixKstat {
+    fn new() -> Self {
+        Self {
+            inode: 0,
+            dev_id: 0,
+            mode: ModeType { bits: 0 },
+            nlink: 0,
+            uid: 0,
+            gid: 0,
+            rdev: 0,
+            size: 0,
+            atime: TimeSpec {
+                tv_sec: 0,
+                tv_nsec: 0,
+            },
+            mtime: TimeSpec {
+                tv_sec: 0,
+                tv_nsec: 0,
+            },
+            ctime: TimeSpec {
+                tv_sec: 0,
+                tv_nsec: 0,
+            },
+            blcok_size: 0,
+            blocks: 0,
+            _pad: Default::default(),
+        }
+    }
+}
+impl Syscall {
+    fn do_fstat(fd: i32) -> Result<PosixKstat, SystemError> {
+        let cur = current_pcb();
+        match cur.get_file_ref_by_fd(fd) {
+            Some(file) => {
+                let mut kstat = PosixKstat::new();
+                // 获取文件信息
+                match file.metadata() {
+                    Ok(metadata) => {
+                        kstat.size = metadata.size as i64;
+                        kstat.dev_id = metadata.dev_id as u64;
+                        kstat.inode = metadata.inode_id as u64;
+                        kstat.blcok_size = metadata.blk_size as i64;
+                        kstat.blocks = metadata.blocks as u64;
+
+                        kstat.atime.tv_sec = metadata.atime.tv_sec;
+                        kstat.atime.tv_nsec = metadata.atime.tv_nsec;
+                        kstat.mtime.tv_sec = metadata.mtime.tv_sec;
+                        kstat.mtime.tv_nsec = metadata.mtime.tv_nsec;
+                        kstat.ctime.tv_sec = metadata.ctime.tv_sec;
+                        kstat.ctime.tv_nsec = metadata.ctime.tv_nsec;
+
+                        kstat.nlink = metadata.nlinks as u64;
+                        kstat.uid = metadata.uid as i32;
+                        kstat.gid = metadata.gid as i32;
+                        kstat.rdev = metadata.raw_dev as i64;
+                        kstat.mode.bits = metadata.mode;
+                        match file.file_type() {
+                            FileType::File => kstat.mode.insert(ModeType::S_IFMT),
+                            FileType::Dir => kstat.mode.insert(ModeType::S_IFDIR),
+                            FileType::BlockDevice => kstat.mode.insert(ModeType::S_IFBLK),
+                            FileType::CharDevice => kstat.mode.insert(ModeType::S_IFCHR),
+                            FileType::SymLink => kstat.mode.insert(ModeType::S_IFLNK),
+                            FileType::Socket => kstat.mode.insert(ModeType::S_IFSOCK),
+                            FileType::Pipe => kstat.mode.insert(ModeType::S_IFIFO),
+                        }
+                    }
+                    Err(e) => return Err(e),
+                }
+
+                return Ok(kstat);
+            }
+            None => {
+                kdebug!("file not be opened");
+                return Err(SystemError::EINVAL);
+            }
+        }
+    }
+    pub fn fstat(fd: i32, usr_kstat: *mut PosixKstat) -> Result<usize, SystemError> {
+        match Self::do_fstat(fd) {
+            Ok(kstat) => {
+                if usr_kstat.is_null() {
+                    return Err(SystemError::EFAULT);
+                }
+                unsafe {
+                    *usr_kstat = kstat;
+                }
+                return Ok(0);
+            }
+            Err(e) => return Err(e),
+        }
+    }
+}