Vendor things

third-party/vendor/nix/test/test_mount.rs

@@ -0,0 +1,271 @@
+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: {}. Are unprivileged user namespaces available?",
+                     e).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 {} 1\n", uid).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() {}