util: clone: add spawn() helper, use in runner

2 files changed, 21 insertions, 8 deletions

diff --git a/src/runner/container/mod.rs b/src/runner/container/mod.rs
index 70c76cc..58823a6 100644
--- a/src/runner/container/mod.rs
+++ b/src/runner/container/mod.rs
@@ -70,16 +70,16 @@ impl ContainerRunner {
 
 		let (tx, rx) = ipc::channel().expect("IPC channel creation failed");
 
-		match clone::clone(CloneFlags::CLONE_NEWUSER | CloneFlags::CLONE_NEWNS).expect("clone()") {
-			unistd::ForkResult::Parent { .. } => {
-				drop(rx);
-			}
-			unistd::ForkResult::Child => {
+		let (_, (tx, _rx)) = clone::spawn(
+			CloneFlags::CLONE_NEWUSER | CloneFlags::CLONE_NEWNS,
+			(tx, rx),
+			|(tx, rx)| {
 				drop(tx);
 				runner(uid, gid, rx);
 				/* Not reached */
-			}
-		};
+			},
+		)
+		.expect("clone()");
 
 		Ok(ContainerRunner { channel: tx })
 	}
diff --git a/src/util/clone.rs b/src/util/clone.rs
index 93b7b24..de3175c 100644
--- a/src/util/clone.rs
+++ b/src/util/clone.rs
@@ -1,4 +1,4 @@
-use std::mem;
+use std::{mem, process};
 
 use nix::{errno, sched, unistd};
 
@@ -34,3 +34,16 @@ pub unsafe fn clone(flags: sched::CloneFlags) -> nix::Result<unistd::ForkResult>
 		})
 	}
 }
+
+pub unsafe fn spawn<T, F>(flags: sched::CloneFlags, arg: T, f: F) -> nix::Result<(unistd::Pid, T)>
+where
+	F: FnOnce(T),
+{
+	match clone(flags)? {
+		unistd::ForkResult::Parent { child } => Ok((child, arg)),
+		unistd::ForkResult::Child => {
+			f(arg);
+			process::exit(0)
+		}
+	}
+}