From 76ac602c3d79bb39c133c81a38425a77bc0b8b1f Mon Sep 17 00:00:00 2001
From: Chuyan Zhang <me@zcy.moe>
Date: Sat, 25 Nov 2023 02:13:22 -0800
Subject: Some FUSE callbacks, some POSIX interface implementation
---
src/utils/constants.rs | 1 +
src/utils/mod.rs | 61 ++++++++++++++++++++++++++++++++++++++++++++++-
src/utils/permissions.rs | 62 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 123 insertions(+), 1 deletion(-)
create mode 100644 src/utils/constants.rs
create mode 100644 src/utils/permissions.rs
(limited to 'src/utils')
diff --git a/src/utils/constants.rs b/src/utils/constants.rs
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/src/utils/constants.rs
@@ -0,0 +1 @@
+
diff --git a/src/utils/mod.rs b/src/utils/mod.rs
index 60b09f2..0a9b825 100644
--- a/src/utils/mod.rs
+++ b/src/utils/mod.rs
@@ -1,7 +1,10 @@
+mod constants;
+pub mod permissions;
+
use crate::block_device::BLOCK_SIZE;
use crate::disk::inode::{Inode, INODE_SIZE};
use crate::{AyaFS, INODE_PER_BLOCK};
-use fuser::FileAttr;
+use fuser::{FileAttr, FileType};
use std::time::{Duration, SystemTime, UNIX_EPOCH};
pub(crate) fn time_now() -> u32 {
@@ -42,6 +45,62 @@ pub(crate) fn to_systime(time: u32) -> SystemTime {
UNIX_EPOCH + Duration::from_secs(time as u64)
}
+// File type code, one of:
+// 0x0 Unknown.
+// 0x1 Regular file.
+// 0x2 Directory.
+// 0x3 Character device file.
+// 0x4 Block device file.
+// 0x5 FIFO.
+// 0x6 Socket.
+// 0x7 Symbolic link.
+
+pub(crate) fn from_filetype(file_type: FileType) -> u8 {
+ match file_type {
+ FileType::NamedPipe => 0x5,
+ FileType::CharDevice => 0x3,
+ FileType::BlockDevice => 0x4,
+ FileType::Directory => 0x2,
+ FileType::RegularFile => 0x1,
+ FileType::Symlink => 0x7,
+ FileType::Socket => 0x6,
+ }
+}
+
+pub(crate) fn to_filetype(file_type: u8) -> Option<FileType> {
+ match file_type {
+ 0x0 => None,
+ 0x1 => Some(FileType::RegularFile),
+ 0x2 => Some(FileType::Directory),
+ 0x3 => Some(FileType::CharDevice),
+ 0x4 => Some(FileType::BlockDevice),
+ 0x5 => Some(FileType::NamedPipe),
+ 0x6 => Some(FileType::Socket),
+ 0x7 => Some(FileType::Symlink),
+ _ => panic!("bad filetype"),
+ }
+}
+
+pub(crate) fn to_fileattr(inode_index: usize, inode: &Inode) -> FileAttr {
+ FileAttr {
+ ino: inode_index as u64,
+ size: inode.size as u64,
+ blocks: inode.n_blocks as u64,
+ atime: to_systime(inode.atime),
+ mtime: to_systime(inode.mtime),
+ ctime: to_systime(inode.ctime),
+ crtime: to_systime(inode.crtime),
+ kind: inode.mode.into(),
+ perm: inode.mode.perm(),
+ nlink: inode.n_links as u32,
+ uid: inode.uid,
+ gid: inode.gid,
+ rdev: 0,
+ blksize: BLOCK_SIZE as u32,
+ flags: inode.flags,
+ }
+}
+
impl AyaFS {
/// 输入 inode 编号, 返回它对应的 block number 和 block 内 offset
pub(crate) fn locate_inode(&self, inode_index: usize) -> (usize, usize) {
diff --git a/src/utils/permissions.rs b/src/utils/permissions.rs
new file mode 100644
index 0000000..a3afe77
--- /dev/null
+++ b/src/utils/permissions.rs
@@ -0,0 +1,62 @@
+use std::fs::File;
+use std::io::BufRead;
+use libc::{F_OK, S_ISGID, S_ISUID, S_IXGRP, X_OK};
+use crate::disk::inode::InodeMode;
+
+pub(crate) fn get_groups(pid: u32) -> Vec<u32> {
+ let file = File::open(format!("/proc/{pid}/task/{pid}/status"))
+ .expect(format!("pid {pid} incorrect!").as_str());
+ for line in std::io::BufReader::new(file).lines() {
+ let line = line.unwrap();
+ if line.starts_with("Groups:") {
+ return line["Groups: ".len()..]
+ .split(' ')
+ .filter(|x| !x.trim().is_empty())
+ .map(|x| x.parse::<u32>().unwrap())
+ .collect();
+ }
+ }
+
+ Vec::new()
+}
+
+pub(crate) fn clear_suid_sgid(mut mode: InodeMode) -> InodeMode {
+ mode.0 &= !S_ISUID as u16;
+ if mode.0 & S_IXGRP as u16 != 0 {
+ mode.0 &= !S_ISGID as u16;
+ }
+ mode
+}
+
+pub(crate) fn check_access(
+ incoming_uid: u32,
+ incoming_gid: u32,
+ uid: u32,
+ gid: u32,
+ perm: InodeMode,
+ mut mask: i32,
+) -> bool {
+ if mask == F_OK {
+ return true;
+ }
+
+ let perm = i32::from(perm.0);
+ // root
+ if incoming_uid == 0 {
+ // 读写任何东西都是可以的, 执行只有 IXOTH/IXGRP/IXUSR 之一设置才可以
+ mask &= X_OK;
+ mask -= mask & (perm >> 6);
+ mask -= mask & (perm >> 3);
+ mask -= mask & perm;
+ return mask == 0;
+ }
+
+ if incoming_uid == uid {
+ mask -= mask & (perm >> 6);
+ } else if incoming_gid == gid {
+ mask -= mask & (perm >> 3);
+ } else {
+ mask -= mask & perm;
+ }
+ mask == 0
+}
\ No newline at end of file
--
cgit v1.2.3-70-g09d2