Initial commit

src/lib.rs

@@ -1 +0,0 @@
-

src/main.rs

@@ -1,3 +1,33 @@
+use std::os::fd::FromRawFd;
+
 fn main() {
-	println!("Hello, world!");
+	let file = if std::fs::metadata("target/release/testexec").is_ok() {
+		std::fs::File::open("target/release/testexec").unwrap()
+	} else if std::fs::metadata("target/debug/testexec").is_ok() {
+		std::fs::File::open("target/debug/testexec").unwrap()
+	} else {
+		panic!("testexec not found");
+	};
+	let filename = "testexec";
+	let name = std::ffi::CString::new(filename).unwrap();
+	let name = name.as_ptr();
+	let mem_file_fd = unsafe { libc::memfd_create(name, 0) };
+	let mem_file = unsafe { std::fs::File::from_raw_fd(mem_file_fd) };
+	let mut reader = std::io::BufReader::new(file);
+	let mut writer = std::io::BufWriter::new(&mem_file);
+	std::io::copy(&mut reader, &mut writer).unwrap();
+
+	let filepath = std::ffi::CString::new(format!("/proc/self/fd/{}", mem_file_fd)).unwrap();
+	let filepath = filepath.as_ptr();
+	let argv_owned = vec![std::ffi::CString::new(filename).unwrap()];
+	let argv: Vec<*const libc::c_char> = argv_owned.iter().map(|x| x.as_ptr()).chain(std::iter::once(std::ptr::null())).collect();
+	let envp_owned = std::env::vars_os()
+		.map(|(k, v)| {
+			let mut kv = k.into_string().unwrap();
+			kv.push('=');
+			kv.push_str(&v.into_string().unwrap());
+			std::ffi::CString::new(kv).unwrap()
+		}).collect::<Vec<_>>();
+	let envp: Vec<*const libc::c_char> = envp_owned.iter().map(|x| x.as_ptr()).chain(std::iter::once(std::ptr::null())).collect();
+	unsafe { libc::execve(filepath, argv.as_ptr(), envp.as_ptr()) };
 }