From 34ac18d20c13a78914d447fee83204811a27b1e4 Mon Sep 17 00:00:00 2001
From: Matthias Schiffer <mschiffer@universe-factory.net>
Date: Mon, 25 Oct 2021 00:19:45 +0200
Subject: Move runner into separate crate

---
 crates/runner/src/tar.rs | 87 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 crates/runner/src/tar.rs

(limited to 'crates/runner/src/tar.rs')

diff --git a/crates/runner/src/tar.rs b/crates/runner/src/tar.rs
new file mode 100644
index 0000000..9306775
--- /dev/null
+++ b/crates/runner/src/tar.rs
@@ -0,0 +1,87 @@
+use std::{
+	fs::File,
+	io::{self, Read, Write},
+	os::unix::prelude::CommandExt,
+	path::Path,
+	process::{self, Command, Stdio},
+};
+
+use nix::{
+	mount::{self, MsFlags},
+	sched::CloneFlags,
+	sys::wait,
+};
+
+use common::error::*;
+
+use super::{
+	ns,
+	util::{fs, Checkable},
+};
+use crate::paths;
+
+pub fn pack<W: Write, P: AsRef<Path>>(archive: &mut W, source: P) -> Result<()> {
+	let (mut piper, pipew) = fs::pipe()?;
+
+	let exec_tar = |stdout: File| -> Result<()> {
+		// We are in our own mount namespace, so mounting into the shared ROOTFS_DIR is fine
+		let mount_target = paths::join(&[paths::ROOTFS_DIR, paths::TASK_BUILDDIR]);
+		mount::mount::<_, _, str, str>(
+			Some(source.as_ref()),
+			mount_target.as_str(),
+			None,
+			MsFlags::MS_BIND,
+			None,
+		)?;
+
+		ns::pivot_root(paths::ROOTFS_DIR);
+
+		let err = Command::new("tar")
+			.args(&[
+				"-c",
+				"--sort=name",
+				"--numeric-owner",
+				"--owner=0",
+				"--group=0",
+				"--mtime=@0",
+				".",
+			])
+			.stdin(Stdio::null())
+			.stdout(stdout)
+			.current_dir(paths::TASK_BUILDDIR)
+			.env_clear()
+			.env("PATH", "/usr/sbin:/usr/bin:/sbin:/bin")
+			.exec();
+		eprintln!("{}", err);
+		process::exit(127);
+	};
+
+	let (pid, pipew) = unsafe {
+		ns::spawn(CloneFlags::CLONE_NEWNS, pipew, |pipew| {
+			exec_tar(pipew).unwrap()
+		})
+	}
+	.context("Failed to run tar")?;
+
+	drop(pipew);
+	let result = io::copy(&mut piper, archive).context("Failed to write TAR archive");
+
+	wait::waitpid(pid, None)?
+		.check()
+		.context("tar did not exit successfully")?;
+
+	result?;
+	Ok(())
+}
+
+pub fn unpack<R: Read, P: AsRef<Path>>(archive: R, dest: P) -> Result<()> {
+	fs::mkdir(&dest)?;
+
+	let mut ar = tar::Archive::new(archive);
+	ar.set_preserve_permissions(true);
+	ar.set_preserve_mtime(true);
+	ar.set_unpack_xattrs(true);
+	ar.set_overwrite(false);
+
+	ar.unpack(dest).context("Failed to unpack TAR archive")
+}
-- 
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