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|
mod init;
mod jobserver;
mod ns;
pub mod paths;
mod tar;
mod task;
mod util;
use std::{fs::File, os::unix::prelude::AsRawFd, path::Path};
use capctl::prctl;
use ipc_channel::ipc;
use nix::{
fcntl,
sched::CloneFlags,
sys::{signal, stat, wait},
unistd::{self, Gid, Uid},
};
use serde::{Deserialize, Serialize};
use common::{error::*, types::*};
use util::fs;
use self::{
jobserver::Jobserver,
util::{clone, unix},
};
#[derive(Debug, Clone)]
pub struct Options {
pub jobs: Option<usize>,
}
#[derive(Debug, Deserialize, Serialize)]
enum Message {
Request(Task, ipc::IpcSender<Result<TaskOutput>>),
}
fn handle_request(
jobserver: Jobserver,
channel: ipc::IpcReceiver<Message>,
task: Task,
reply_channel: ipc::IpcSender<Result<TaskOutput>>,
) -> (Jobserver, ipc::IpcReceiver<Message>) {
let child = |(mut jobserver, channel): (Jobserver, ipc::IpcReceiver<Message>)| {
drop(channel);
unsafe { signal::signal(signal::Signal::SIGCHLD, signal::SigHandler::SigDfl) }.unwrap();
prctl::set_name(&task.label).expect("prctl(PR_SET_NAME)");
let token = jobserver.wait();
let (pid, mut jobserver) = unsafe {
clone::spawn(None, jobserver, |jobserver| {
let result = task::handle(task, jobserver);
reply_channel.send(result).expect("IPC send() failed");
})
}
.expect("fork()");
let wait_res = wait::waitpid(pid, None);
jobserver.post(token);
wait_res.expect("waitpid()");
};
unsafe { clone::spawn(None, (jobserver, channel), child) }
.expect("fork()")
.1
}
fn runner_loop(mut channel: ipc::IpcReceiver<Message>, options: &Options) {
let jobs = options
.jobs
.unwrap_or_else(|| unix::nproc().expect("Failed to get number of available CPUs"));
let mut jobserver = Jobserver::new(jobs).expect("Failed to initialize jobserver pipe");
while let Ok(msg) = channel.recv() {
match msg {
Message::Request(task, reply_channel) => {
let ret = handle_request(jobserver, channel, task, reply_channel);
jobserver = ret.0;
channel = ret.1;
}
}
}
}
fn runner(
uid: Uid,
gid: Gid,
channel: ipc::IpcReceiver<Message>,
_lockfile: File,
options: &Options,
) {
ns::mount_proc();
ns::setup_userns(Uid::from_raw(0), Gid::from_raw(0), uid, gid);
stat::umask(stat::Mode::from_bits_truncate(0o022));
init::init_runner().unwrap();
let msg_handler = unsafe {
clone::spawn(None, (), |()| {
signal::signal(signal::Signal::SIGCHLD, signal::SigHandler::SigIgn).unwrap();
runner_loop(channel, options);
})
}
.expect("fork()")
.0;
loop {
let status = wait::wait().expect("wait()");
if status.pid() == Some(msg_handler) {
break;
}
}
}
pub struct Runner {
channel: ipc::IpcSender<Message>,
}
impl Runner {
/// Creates a new container runner
///
/// Unsafe: Do not call in multithreaded processes
pub unsafe fn new(options: &Options) -> Result<Self> {
let lockfile = Runner::lock()?;
let uid = unistd::geteuid();
let gid = unistd::getegid();
let (tx, rx) = ipc::channel().expect("IPC channel creation failed");
let (tx, _rx) = clone::spawn(
Some(CloneFlags::CLONE_NEWUSER | CloneFlags::CLONE_NEWNS | CloneFlags::CLONE_NEWPID),
(tx, rx),
|(tx, rx)| {
drop(tx);
runner(uid, gid, rx, lockfile, options);
},
)
.expect("clone()")
.1;
Ok(Runner { channel: tx })
}
fn lock() -> Result<File> {
let path = Path::new(paths::LOCKFILE);
fs::mkdir(path.parent().unwrap())?;
let file = fs::create(path)?;
fcntl::flock(file.as_raw_fd(), fcntl::FlockArg::LockExclusiveNonblock)
.context("Failed to get lock on build directory, is another instance running?")?;
Ok(file)
}
pub fn spawn(&self, task: &Task) -> ipc::IpcReceiver<Result<TaskOutput>> {
let (reply_tx, reply_rx) = ipc::channel().expect("IPC channel creation failed");
self.channel
.send(Message::Request(task.clone(), reply_tx))
.expect("ContainerRunner task submission failed");
reply_rx
}
}
|
