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extern crate libc;
extern crate unix_socket;
mod platform;
pub mod fs;
use std::{io, process, mem};
use std::collections::BTreeMap;
use std::path::Path;
use unix_socket::UnixStream;
pub struct RunningSandbox {
pid: libc::c_int,
pub socket: UnixStream,
}
impl RunningSandbox {
pub fn wait(self) -> io::Result<RunningSandbox> {
let mut status = 0;
unsafe { libc::waitpid(self.pid, &mut status, 0) };
if status == 0 {
Ok(self)
} else {
Err(io::Error::new(io::ErrorKind::Other, "Sandboxed child process exited with non-zero status"))
}
}
}
pub struct SandboxContext {
dirs: BTreeMap<String, fs::Directory>,
}
impl SandboxContext {
pub fn directory(&self, key: &str) -> Option<&fs::Directory> {
self.dirs.get(key)
}
}
pub struct Sandbox {
dirs: BTreeMap<String, fs::Directory>,
}
impl Sandbox {
pub fn new() -> Sandbox {
Sandbox {
dirs: BTreeMap::new()
}
}
pub fn add_directory<P: AsRef<Path>>(&mut self, key: &str, path: P) -> &mut Sandbox {
if let Some(dir) = fs::Directory::new(path) {
self.dirs.insert(key.to_owned(), dir);
}
self
}
pub fn sandbox_this_process(&self) -> Result<SandboxContext, ()> {
if platform::enter_sandbox(Box::new(self.dirs.values())) {
Ok(self.context())
} else {
Err(())
}
}
pub fn sandboxed_fork<F>(&self, fun: F) -> io::Result<RunningSandbox>
where F: Fn(&mut SandboxContext, &mut UnixStream) -> () {
let (parent_socket, child_socket) = try!(UnixStream::pair());
let pid = unsafe { libc::fork() };
if pid < 0 {
Err(io::Error::new(io::ErrorKind::Other, "fork() failed"))
} else if pid > 0 { Ok(RunningSandbox {
pid: pid,
socket: parent_socket,
})
} else { mem::drop(parent_socket);
platform::enter_sandbox(Box::new(self.dirs.values()));
let mut socket = child_socket;
fun(&mut self.context(), &mut socket);
process::exit(0);
}
}
fn context(&self) -> SandboxContext {
SandboxContext {
dirs: self.dirs.to_owned(),
}
}
}
#[cfg(test)]
mod tests {
use super::*;
use std::net;
use std::fs::File;
use std::io::{Read, Write, BufRead, BufReader};
#[test]
fn test_socket() {
let mut process = Sandbox::new()
.sandboxed_fork(|_, socket| {
let msg = BufReader::new(socket.try_clone().unwrap()).lines().next().unwrap().unwrap() + " > from sandbox\n";
socket.write_all(msg.as_bytes()).unwrap();
socket.flush().unwrap();
})
.unwrap();
process.socket.write_all(b"from parent\n").unwrap();
process.socket.flush().unwrap();
let msg = BufReader::new(process.socket.try_clone().unwrap()).lines().next().unwrap().unwrap();
assert_eq!(msg, "from parent > from sandbox");
process.wait().unwrap();
}
#[test]
fn test_preopened_file() {
let mut f = File::open("UNLICENSE").unwrap();
let mut process = Sandbox::new()
.sandboxed_fork(|_, socket| {
let mut buf = String::new();
BufReader::new(&f).read_line(&mut buf).unwrap();
let msg = buf.replace("\n", "") + " from sandbox\n";
socket.write_all(msg.as_bytes()).unwrap();
socket.flush().unwrap();
})
.unwrap();
let msg = BufReader::new(process.socket.try_clone().unwrap()).lines().next().unwrap().unwrap();
assert_eq!(msg, "This is free and unencumbered software released into the public domain. from sandbox");
process.wait().unwrap();
}
#[cfg(not(target_os = "openbsd"))]
#[test]
fn test_directory() {
Sandbox::new()
.add_directory("temp", "/tmp")
.sandboxed_fork(|ctx, _| {
let mut file = ctx.directory("temp").unwrap()
.open_options().write(true).create(true)
.open("hello_rusty_sandbox").unwrap();
file.write_all(b"Hello World").unwrap();
}).unwrap().wait().unwrap();
let mut buf = Vec::new();
let mut f = File::open("/tmp/hello_rusty_sandbox").unwrap();
f.read_to_end(&mut buf).unwrap();
assert_eq!(&buf[..], b"Hello World");
}
#[cfg(not(target_os = "openbsd"))]
#[test]
fn test_forbidden_file() {
let process = Sandbox::new()
.sandboxed_fork(|_, socket| {
socket.write_all(match File::open("README.md") {
Ok(_) => b"ok",
Err(_) => b"err",
}).unwrap();
socket.flush().unwrap();
})
.unwrap();
let msg = BufReader::new(process.socket.try_clone().unwrap()).lines().next().unwrap().unwrap();
assert_eq!(msg, "err");
process.wait().unwrap();
}
#[cfg(not(target_os = "openbsd"))]
#[test]
fn test_forbidden_socket() {
let process = Sandbox::new()
.sandboxed_fork(|_, socket| {
socket.write_all(match net::TcpStream::connect("8.8.8.8:53") { Ok(_) => b"ok",
Err(_) => b"err",
}).unwrap();
socket.flush().unwrap();
})
.unwrap();
let msg = BufReader::new(process.socket.try_clone().unwrap()).lines().next().unwrap().unwrap();
assert_eq!(msg, "err");
process.wait().unwrap();
}
}
