libs/sys-util: add wrappers for mount and fs

Add some wrappers for mount and fs syscall.

Signed-off-by: Liu Jiang <gerry@linux.alibaba.com>
Signed-off-by: Bin Liu <bin@hyper.sh>
Signed-off-by: Fupan Li <lifupan@gmail.com>
Signed-off-by: Huamin Tang <huamin.thm@alibaba-inc.com>
Signed-off-by: Lei Wang <wllenyj@linux.alibaba.com>
Signed-off-by: Quanwei Zhou <quanweiZhou@linux.alibaba.com>

src/libs/Cargo.lock

@@ -36,9 +36,9 @@ dependencies = [
 
 [[package]]
 name = "autocfg"
-version = "1.0.1"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cdb031dd78e28731d87d56cc8ffef4a8f36ca26c38fe2de700543e627f8a464a"
+checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
 
 [[package]]
 name = "bitflags"
@@ -92,6 +92,12 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "common-path"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2382f75942f4b3be3690fe4f86365e9c853c1587d6ee58212cebf6e2a9ccd101"
+
 [[package]]
 name = "crossbeam-channel"
 version = "0.5.2"
@@ -129,6 +135,17 @@ version = "1.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e78d4f1cc4ae33bbfc157ed5d5a5ef3bc29227303d595861deb238fcec4e9457"
 
+[[package]]
+name = "fail"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec3245a0ca564e7f3c797d20d833a6870f57a728ac967d5225b3ffdef4465011"
+dependencies = [
+ "lazy_static",
+ "log",
+ "rand",
+]
+
 [[package]]
 name = "fastrand"
 version = "1.6.0"
@@ -233,6 +250,17 @@ dependencies = [
  "slab",
 ]
 
+[[package]]
+name = "getrandom"
+version = "0.2.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9be70c98951c83b8d2f8f60d7065fa6d5146873094452a1008da8c2f1e4205ad"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi 0.10.2+wasi-snapshot-preview1",
+]
+
 [[package]]
 name = "glob"
 version = "0.3.0"
@@ -309,6 +337,18 @@ checksum = "1aab8fc367588b89dcee83ab0fd66b72b50b72fa1904d7095045ace2b0c81c35"
 [[package]]
 name = "kata-sys-util"
 version = "0.1.0"
+dependencies = [
+ "common-path",
+ "fail",
+ "kata-types",
+ "lazy_static",
+ "libc",
+ "nix 0.23.1",
+ "slog",
+ "slog-scope",
+ "tempfile",
+ "thiserror",
+]
 
 [[package]]
 name = "kata-types"
@@ -385,7 +425,7 @@ dependencies = [
  "log",
  "miow",
  "ntapi",
- "wasi",
+ "wasi 0.11.0+wasi-snapshot-preview1",
  "winapi",
 ]
 
@@ -506,6 +546,12 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
 
+[[package]]
+name = "ppv-lite86"
+version = "0.2.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eb9f9e6e233e5c4a35559a617bf40a4ec447db2e84c20b55a6f83167b7e57872"
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.37"
@@ -616,6 +662,36 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "rand"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
+dependencies = [
+ "libc",
+ "rand_chacha",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
+dependencies = [
+ "ppv-lite86",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.6.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d34f1408f55294453790c48b2f1ebbb1c5b4b7563eb1f418bcfcfdbb06ebb4e7"
+dependencies = [
+ "getrandom",
+]
+
 [[package]]
 name = "redox_syscall"
 version = "0.2.10"
@@ -667,18 +743,18 @@ dependencies = [
 
 [[package]]
 name = "serde"
-version = "1.0.135"
+version = "1.0.136"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2cf9235533494ea2ddcdb794665461814781c53f19d87b76e571a1c35acbad2b"
+checksum = "ce31e24b01e1e524df96f1c2fdd054405f8d7376249a5110886fb4b658484789"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.135"
+version = "1.0.136"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8dcde03d87d4c973c04be249e7d8f0b35db1c848c487bd43032808e59dd8328d"
+checksum = "08597e7152fcd306f41838ed3e37be9eaeed2b61c42e2117266a554fab4662f9"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -806,9 +882,9 @@ dependencies = [
 
 [[package]]
 name = "thread_local"
-version = "1.1.3"
+version = "1.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8018d24e04c95ac8790716a5987d0fec4f8b27249ffa0f7d33f1369bdfb88cbd"
+checksum = "5516c27b78311c50bf42c071425c560ac799b11c30b31f87e3081965fe5e0180"
 dependencies = [
  "once_cell",
 ]
@@ -930,6 +1006,12 @@ dependencies = [
  "nix 0.23.1",
 ]
 
+[[package]]
+name = "wasi"
+version = "0.10.2+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd6fbd9a79829dd1ad0cc20627bf1ed606756a7f77edff7b66b7064f9cb327c6"
+
 [[package]]
 name = "wasi"
 version = "0.11.0+wasi-snapshot-preview1"

src/libs/kata-sys-util/Cargo.toml

@@ -11,3 +11,16 @@ license = "Apache-2.0"
 edition = "2018"
 
 [dependencies]
+common-path = "=1.0.0"
+fail = "0.5.0"
+lazy_static = "1.4.0"
+libc = "0.2.100"
+nix = "0.23.0"
+slog = "2.5.2"
+slog-scope = "4.4.0"
+thiserror = "1.0.30"
+
+kata-types = { path = "../kata-types" }
+
+[dev-dependencies]
+tempfile = "3.2.0"

src/libs/kata-sys-util/src/fs.rs

@@ -0,0 +1,111 @@
+// Copyright (c) 2019-2021 Alibaba Cloud
+// Copyright (c) 2019-2021 Ant Group
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+use std::ffi::OsString;
+use std::fs;
+use std::io::Result;
+use std::path::{Path, PathBuf};
+
+use crate::eother;
+
+// from linux.git/fs/fuse/inode.c: #define FUSE_SUPER_MAGIC 0x65735546
+const FUSE_SUPER_MAGIC: u32 = 0x65735546;
+
+/// Get bundle path (current working directory).
+pub fn get_bundle_path() -> Result<PathBuf> {
+    std::env::current_dir()
+}
+
+/// Get the basename of the canonicalized path
+pub fn get_base_name<P: AsRef<Path>>(src: P) -> Result<OsString> {
+    let s = src.as_ref().canonicalize()?;
+    s.file_name().map(|v| v.to_os_string()).ok_or_else(|| {
+        eother!(
+            "failed to get base name of path {}",
+            src.as_ref().to_string_lossy()
+        )
+    })
+}
+
+/// Check whether `path` is on a fuse filesystem.
+pub fn is_fuse_fs<P: AsRef<Path>>(path: P) -> bool {
+    if let Ok(st) = nix::sys::statfs::statfs(path.as_ref()) {
+        if st.filesystem_type().0 == FUSE_SUPER_MAGIC as i64 {
+            return true;
+        }
+    }
+    false
+}
+
+/// Check whether `path` is on a overlay filesystem.
+pub fn is_overlay_fs<P: AsRef<Path>>(path: P) -> bool {
+    if let Ok(st) = nix::sys::statfs::statfs(path.as_ref()) {
+        if st.filesystem_type() == nix::sys::statfs::OVERLAYFS_SUPER_MAGIC {
+            return true;
+        }
+    }
+    false
+}
+
+/// Check whether the given path is a symlink.
+pub fn is_symlink<P: AsRef<Path>>(path: P) -> std::io::Result<bool> {
+    let path = path.as_ref();
+    let meta = fs::symlink_metadata(path)?;
+
+    Ok(meta.file_type().is_symlink())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::mount::umount_all;
+    use std::process::Command;
+    use thiserror::private::PathAsDisplay;
+
+    #[test]
+    fn test_get_base_name() {
+        assert_eq!(&get_base_name("/etc/hostname").unwrap(), "hostname");
+        assert_eq!(&get_base_name("/bin").unwrap(), "bin");
+        assert!(&get_base_name("/").is_err());
+        assert!(&get_base_name("").is_err());
+        assert!(get_base_name("/no/such/path________yeah").is_err());
+    }
+
+    #[test]
+    fn test_is_symlink() {
+        let tmpdir = tempfile::tempdir().unwrap();
+        let path = tmpdir.path();
+
+        std::os::unix::fs::symlink(path, path.join("a")).unwrap();
+        assert!(is_symlink(path.join("a")).unwrap());
+    }
+
+    #[test]
+    fn test_is_overlayfs() {
+        let tmpdir1 = tempfile::tempdir().unwrap();
+        let tmpdir2 = tempfile::tempdir().unwrap();
+        let tmpdir3 = tempfile::tempdir().unwrap();
+        let tmpdir4 = tempfile::tempdir().unwrap();
+
+        let option = format!(
+            "-o lowerdir={},upperdir={},workdir={}",
+            tmpdir1.path().as_display(),
+            tmpdir2.path().display(),
+            tmpdir3.path().display()
+        );
+        let target = format!("{}", tmpdir4.path().display());
+
+        Command::new("/bin/mount")
+            .arg("-t overlay")
+            .arg(option)
+            .arg("overlay")
+            .arg(target)
+            .output()
+            .unwrap();
+        assert!(is_overlay_fs(tmpdir4.path()));
+        umount_all(tmpdir4.path(), false).unwrap();
+    }
+}

src/libs/kata-sys-util/src/lib.rs

@@ -2,3 +2,25 @@
 //
 // SPDX-License-Identifier: Apache-2.0
 //
+
+#[macro_use]
+extern crate slog;
+
+pub mod fs;
+pub mod mount;
+
+// Convenience macro to obtain the scoped logger
+#[macro_export]
+macro_rules! sl {
+    () => {
+        slog_scope::logger()
+    };
+}
+
+#[macro_export]
+macro_rules! eother {
+    () => (std::io::Error::new(std::io::ErrorKind::Other, ""));
+    ($fmt:expr, $($arg:tt)*) => ({
+        std::io::Error::new(std::io::ErrorKind::Other, format!($fmt, $($arg)*))
+    })
+}