Merge x11bridge into the server process.

Signed-off-by: Sasha Finkelstein <[email protected]>

Author: WhatAmISupposedToPutHere

crates/muvm/Cargo.toml

@@ -39,7 +39,3 @@ path = "src/guest/bin/muvm-guest.rs"
 [[bin]]
 name = "muvm-hidpipe"
 path = "src/hidpipe/bin/muvm-hidpipe.rs"
-
-[[bin]]
-name = "muvm-x11bridge"
-path = "src/x11bridge/bin/muvm-x11bridge.rs"

crates/muvm/src/guest/bin/muvm-guest.rs

@@ -1,6 +1,6 @@
-use std::cmp;
 use std::os::fd::AsFd;
 use std::process::Command;
+use std::{cmp, env};
 
 use anyhow::{Context, Result};
 use muvm::env::find_muvm_exec;
@@ -12,11 +12,17 @@ use muvm::guest::server::server_main;
 use muvm::guest::socket::setup_socket_proxy;
 use muvm::guest::user::setup_user;
 use muvm::guest::x11::setup_x11_forwarding;
+use muvm::guest::x11bridge::start_x11bridge;
 use rustix::process::{getrlimit, setrlimit, Resource};
 
 fn main() -> Result<()> {
     env_logger::init();
 
+    if let Ok(val) = env::var("__X11BRIDGE_DEBUG") {
+        start_x11bridge(val.parse()?);
+        return Ok(());
+    }
+
     let options = options().run();
 
     {

crates/muvm/src/guest/mod.rs

@@ -7,3 +7,4 @@ pub mod server_worker;
 pub mod socket;
 pub mod user;
 pub mod x11;
+pub mod x11bridge;

crates/muvm/src/guest/x11.rs

@@ -1,13 +1,13 @@
-use std::env;
 use std::fs::File;
 use std::io::{Read, Write};
+use std::panic::catch_unwind;
 use std::path::Path;
-use std::process::Command;
+use std::{env, thread};
 
 use anyhow::{anyhow, Context, Result};
 use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
 
-use crate::env::find_muvm_exec;
+use crate::guest::x11bridge::start_x11bridge;
 
 pub fn setup_x11_forwarding<P>(run_path: P) -> Result<bool>
 where
@@ -24,11 +24,6 @@ where
     }
     let host_display = &host_display[1..];
 
-    let mut cmd = Command::new(find_muvm_exec("muvm-x11bridge")?);
-    cmd.args(["--listen-display", ":1"]);
-
-    cmd.spawn().context("Failed to spawn `muvm-x11bridge`")?;
-
     // SAFETY: Safe if and only if `muvm-guest` program is not multithreaded.
     // See https://doc.rust-lang.org/std/env/fn.set_var.html#safety
     env::set_var("DISPLAY", ":1");
@@ -89,6 +84,11 @@ where
         // See https://doc.rust-lang.org/std/env/fn.set_var.html#safety
         env::set_var("XAUTHORITY", dst_path);
     }
+    thread::spawn(|| {
+        if catch_unwind(|| start_x11bridge(1)).is_err() {
+            eprintln!("x11bridge thread crashed, x11 passthrough will no longer function");
+        }
+    });
 
     Ok(true)
 }

…muvm/src/x11bridge/bin/muvm-x11bridge.rs crates/muvm/src/guest/x11bridge.rscrates/muvm/src/x11bridge/bin/muvm-x11bridge.rs renamed to crates/muvm/src/guest/x11bridge.rs crates/muvm/src/x11bridge/bin/muvm-x11bridge.rs renamed to crates/muvm/src/guest/x11bridge.rs

@@ -1,5 +1,4 @@
 use anyhow::Result;
-use bpaf::{construct, long, OptionParser, Parser};
 use nix::errno::Errno;
 use nix::fcntl::readlink;
 use nix::libc::{
@@ -18,7 +17,7 @@ use nix::sys::socket::{
 use nix::sys::stat::fstat;
 use nix::sys::uio::{process_vm_writev, RemoteIoVec};
 use nix::sys::wait::{waitpid, WaitPidFlag, WaitStatus};
-use nix::unistd::{getresgid, getresuid, mkstemp, read, setegid, seteuid, Pid};
+use nix::unistd::{mkstemp, read, Pid};
 use nix::{cmsg_space, ioctl_read, ioctl_readwrite, ioctl_write_ptr, NixPath};
 use std::borrow::Cow;
 use std::cell::RefCell;
@@ -1445,36 +1444,8 @@ fn find_vdso(pid: Option<Pid>) -> Result<(usize, usize), Errno> {
     Err(Errno::EINVAL)
 }
 
-#[derive(Clone, Debug)]
-pub struct Options {
-    listen_display: String,
-}
-
-pub fn options() -> OptionParser<Options> {
-    let listen_display = long("listen-display")
-        .short('l')
-        .help("The X11 display number to listen on")
-        .argument("DISPLAY")
-        .fallback(":0".into());
-
-    construct!(Options { listen_display }).to_options()
-}
-
-fn main() {
-    let options = options().fallback_to_usage().run();
-
-    let display = if options.listen_display.starts_with(':') {
-        options.listen_display[1..].parse::<u32>().ok()
-    } else {
-        None
-    };
-
-    let sock_path = if let Some(display) = display {
-        format!("/tmp/.X11-unix/X{}", display)
-    } else {
-        eprintln!("Invalid --listen-display value");
-        exit(1)
-    };
+pub fn start_x11bridge(display: u32) {
+    let sock_path = format!("/tmp/.X11-unix/X{}", display);
 
     // Look for a syscall instruction in the vDSO. We assume all processes map
     // the same vDSO (which should be true if they are running under the same
@@ -1495,21 +1466,7 @@ fn main() {
 
     let epoll = Epoll::new(EpollCreateFlags::empty()).unwrap();
     _ = fs::remove_file(&sock_path);
-    let resuid = getresuid().unwrap();
-    let resgid = getresgid().unwrap();
-    if resuid.real != resuid.effective {
-        seteuid(resuid.real).unwrap();
-    }
-    if resgid.real != resgid.effective {
-        setegid(resgid.real).unwrap()
-    }
     let listen_sock = UnixListener::bind(sock_path).unwrap();
-    if resuid.real != resuid.effective {
-        seteuid(resuid.effective).unwrap();
-    }
-    if resgid.real != resgid.effective {
-        setegid(resgid.effective).unwrap()
-    }
     epoll
         .add(
             &listen_sock,
@@ -1640,13 +1597,3 @@ fn main() {
         }
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn check_options() {
-        options().check_invariants(false)
-    }
-}