From 26a029d407be480d791972afb5975cf62c9360a6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 02:47:55 +0200 Subject: Adding upstream version 124.0.1. Signed-off-by: Daniel Baumann --- third_party/rust/nix/test/test_mount.rs | 267 ++++++++++++++++++++++++++++++++ 1 file changed, 267 insertions(+) create mode 100644 third_party/rust/nix/test/test_mount.rs (limited to 'third_party/rust/nix/test/test_mount.rs') diff --git a/third_party/rust/nix/test/test_mount.rs b/third_party/rust/nix/test/test_mount.rs new file mode 100644 index 0000000000..5cf00408e8 --- /dev/null +++ b/third_party/rust/nix/test/test_mount.rs @@ -0,0 +1,267 @@ +mod common; + +// Implementation note: to allow unprivileged users to run it, this test makes +// use of user and mount namespaces. On systems that allow unprivileged user +// namespaces (Linux >= 3.8 compiled with CONFIG_USER_NS), the test should run +// without root. + +#[cfg(target_os = "linux")] +mod test_mount { + use std::fs::{self, File}; + use std::io::{self, Read, Write}; + use std::os::unix::fs::OpenOptionsExt; + use std::os::unix::fs::PermissionsExt; + use std::process::{self, Command}; + + use libc::{EACCES, EROFS}; + + use nix::errno::Errno; + use nix::mount::{mount, umount, MsFlags}; + use nix::sched::{unshare, CloneFlags}; + use nix::sys::stat::{self, Mode}; + use nix::unistd::getuid; + + static SCRIPT_CONTENTS: &[u8] = b"#!/bin/sh +exit 23"; + + const EXPECTED_STATUS: i32 = 23; + + const NONE: Option<&'static [u8]> = None; + #[allow(clippy::bind_instead_of_map)] // False positive + pub fn test_mount_tmpfs_without_flags_allows_rwx() { + let tempdir = tempfile::tempdir().unwrap(); + + mount( + NONE, + tempdir.path(), + Some(b"tmpfs".as_ref()), + MsFlags::empty(), + NONE, + ) + .unwrap_or_else(|e| panic!("mount failed: {e}")); + + let test_path = tempdir.path().join("test"); + + // Verify write. + fs::OpenOptions::new() + .create(true) + .write(true) + .mode((Mode::S_IRWXU | Mode::S_IRWXG | Mode::S_IRWXO).bits()) + .open(&test_path) + .or_else(|e| { + if Errno::from_i32(e.raw_os_error().unwrap()) + == Errno::EOVERFLOW + { + // Skip tests on certain Linux kernels which have a bug + // regarding tmpfs in namespaces. + // Ubuntu 14.04 and 16.04 are known to be affected; 16.10 is + // not. There is no legitimate reason for open(2) to return + // EOVERFLOW here. + // https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1659087 + let stderr = io::stderr(); + let mut handle = stderr.lock(); + writeln!( + handle, + "Buggy Linux kernel detected. Skipping test." + ) + .unwrap(); + process::exit(0); + } else { + panic!("open failed: {e}"); + } + }) + .and_then(|mut f| f.write(SCRIPT_CONTENTS)) + .unwrap_or_else(|e| panic!("write failed: {e}")); + + // Verify read. + let mut buf = Vec::new(); + File::open(&test_path) + .and_then(|mut f| f.read_to_end(&mut buf)) + .unwrap_or_else(|e| panic!("read failed: {e}")); + assert_eq!(buf, SCRIPT_CONTENTS); + + // Verify execute. + assert_eq!( + EXPECTED_STATUS, + Command::new(&test_path) + .status() + .unwrap_or_else(|e| panic!("exec failed: {e}")) + .code() + .unwrap_or_else(|| panic!("child killed by signal")) + ); + + umount(tempdir.path()).unwrap_or_else(|e| panic!("umount failed: {e}")); + } + + pub fn test_mount_rdonly_disallows_write() { + let tempdir = tempfile::tempdir().unwrap(); + + mount( + NONE, + tempdir.path(), + Some(b"tmpfs".as_ref()), + MsFlags::MS_RDONLY, + NONE, + ) + .unwrap_or_else(|e| panic!("mount failed: {e}")); + + // EROFS: Read-only file system + assert_eq!( + EROFS, + File::create(tempdir.path().join("test")) + .unwrap_err() + .raw_os_error() + .unwrap() + ); + + umount(tempdir.path()).unwrap_or_else(|e| panic!("umount failed: {e}")); + } + + pub fn test_mount_noexec_disallows_exec() { + let tempdir = tempfile::tempdir().unwrap(); + + mount( + NONE, + tempdir.path(), + Some(b"tmpfs".as_ref()), + MsFlags::MS_NOEXEC, + NONE, + ) + .unwrap_or_else(|e| panic!("mount failed: {e}")); + + let test_path = tempdir.path().join("test"); + + fs::OpenOptions::new() + .create(true) + .write(true) + .mode((Mode::S_IRWXU | Mode::S_IRWXG | Mode::S_IRWXO).bits()) + .open(&test_path) + .and_then(|mut f| f.write(SCRIPT_CONTENTS)) + .unwrap_or_else(|e| panic!("write failed: {e}")); + + // Verify that we cannot execute despite a+x permissions being set. + let mode = stat::Mode::from_bits_truncate( + fs::metadata(&test_path) + .map(|md| md.permissions().mode()) + .unwrap_or_else(|e| panic!("metadata failed: {e}")), + ); + + assert!( + mode.contains(Mode::S_IXUSR | Mode::S_IXGRP | Mode::S_IXOTH), + "{:?} did not have execute permissions", + &test_path + ); + + // EACCES: Permission denied + assert_eq!( + EACCES, + Command::new(&test_path) + .status() + .unwrap_err() + .raw_os_error() + .unwrap() + ); + + umount(tempdir.path()).unwrap_or_else(|e| panic!("umount failed: {e}")); + } + + pub fn test_mount_bind() { + let tempdir = tempfile::tempdir().unwrap(); + let file_name = "test"; + + { + let mount_point = tempfile::tempdir().unwrap(); + + mount( + Some(tempdir.path()), + mount_point.path(), + NONE, + MsFlags::MS_BIND, + NONE, + ) + .unwrap_or_else(|e| panic!("mount failed: {e}")); + + fs::OpenOptions::new() + .create(true) + .write(true) + .mode((Mode::S_IRWXU | Mode::S_IRWXG | Mode::S_IRWXO).bits()) + .open(mount_point.path().join(file_name)) + .and_then(|mut f| f.write(SCRIPT_CONTENTS)) + .unwrap_or_else(|e| panic!("write failed: {e}")); + + umount(mount_point.path()) + .unwrap_or_else(|e| panic!("umount failed: {e}")); + } + + // Verify the file written in the mount shows up in source directory, even + // after unmounting. + + let mut buf = Vec::new(); + File::open(tempdir.path().join(file_name)) + .and_then(|mut f| f.read_to_end(&mut buf)) + .unwrap_or_else(|e| panic!("read failed: {e}")); + assert_eq!(buf, SCRIPT_CONTENTS); + } + + pub fn setup_namespaces() { + // Hold on to the uid in the parent namespace. + let uid = getuid(); + + unshare(CloneFlags::CLONE_NEWNS | CloneFlags::CLONE_NEWUSER).unwrap_or_else(|e| { + let stderr = io::stderr(); + let mut handle = stderr.lock(); + writeln!(handle, + "unshare failed: {e}. Are unprivileged user namespaces available?").unwrap(); + writeln!(handle, "mount is not being tested").unwrap(); + // Exit with success because not all systems support unprivileged user namespaces, and + // that's not what we're testing for. + process::exit(0); + }); + + // Map user as uid 1000. + fs::OpenOptions::new() + .write(true) + .open("/proc/self/uid_map") + .and_then(|mut f| f.write(format!("1000 {uid} 1\n").as_bytes())) + .unwrap_or_else(|e| panic!("could not write uid map: {e}")); + } +} + +// Test runner + +/// Mimic normal test output (hackishly). +#[cfg(target_os = "linux")] +macro_rules! run_tests { + ( $($test_fn:ident),* ) => {{ + println!(); + + $( + print!("test test_mount::{} ... ", stringify!($test_fn)); + $test_fn(); + println!("ok"); + )* + + println!(); + }} +} + +#[cfg(target_os = "linux")] +fn main() { + use test_mount::{ + setup_namespaces, test_mount_bind, test_mount_noexec_disallows_exec, + test_mount_rdonly_disallows_write, + test_mount_tmpfs_without_flags_allows_rwx, + }; + skip_if_cirrus!("Fails for an unknown reason Cirrus CI. Bug #1351"); + setup_namespaces(); + + run_tests!( + test_mount_tmpfs_without_flags_allows_rwx, + test_mount_rdonly_disallows_write, + test_mount_noexec_disallows_exec, + test_mount_bind + ); +} + +#[cfg(not(target_os = "linux"))] +fn main() {} -- cgit v1.2.3