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|
use crate::model::Trojan;
use anyhow::{Context, Result, ensure};
use serde_json::{Value, json};
use std::{
fs,
os::unix::fs::{MetadataExt, PermissionsExt},
path::Path,
process::Stdio,
time::Duration,
};
use tokio::process::Command;
pub const RUNTIME_DIR: &str = "/run/roentgen";
pub fn identity() -> Result<(u32, u32)> {
let mut buffer = vec![0u8; 65536];
let mut record = std::mem::MaybeUninit::<libc::passwd>::uninit();
let mut result = std::ptr::null_mut();
// SAFETY: the output record and buffer are writable and remain alive while
// the reentrant account lookup fills them. The returned IDs are copied.
let error = unsafe {
libc::getpwnam_r(
c"roentgen-xray".as_ptr(),
record.as_mut_ptr(),
buffer.as_mut_ptr().cast(),
buffer.len(),
&mut result,
)
};
ensure!(
error == 0 && !result.is_null(),
"Missing roentgen-xray service account; run roentgen install"
);
let record = unsafe { record.assume_init() };
ensure!(
record.pw_uid != 0 && record.pw_gid != 0,
"Xray must use a dedicated non-root account and group"
);
Ok((record.pw_uid, record.pw_gid))
}
pub async fn preflight() -> Result<()> {
let metadata =
fs::metadata("/usr/bin/xray").context("Install ALT's current xray package first")?;
ensure!(
metadata.uid() == 0 && metadata.permissions().mode() & 0o022 == 0,
"System Xray must be root-owned and not writable by other users"
);
let output = tokio::time::timeout(
Duration::from_secs(5),
Command::new("/usr/bin/xray").arg("version").output(),
)
.await??;
ensure!(
output.status.success(),
"Could not read system Xray version"
);
let version = String::from_utf8_lossy(&output.stdout);
let version = version.split_whitespace().nth(1).unwrap_or("");
// Native TUN routing behavior is pinned to the researched release family.
ensure!(
matches!(version, "26.10.29"),
"Unsupported Xray release; this build requires validated Xray 26.10.29 capabilities"
);
ensure!(
Path::new("/dev/net/tun").exists(),
"Linux TUN is unavailable"
);
Ok(())
}
pub fn configuration(connection: &Trojan, tun: bool) -> Value {
let mut inbounds = vec![];
if tun {
inbounds.push(json!({"tag":"host-tun","protocol":"tun","settings":{"name":"roentgen0","MTU":1500,"gateway":["198.18.0.1/30","fdfe:726f:656e::1/126"],"autoSystemRoutingTable":[],"autoOutboundsInterface":"","autoSystemDnsToGateway":false}}));
}
let mut tls = json!({"serverName":connection.server_name,"allowInsecure":false});
if !connection.alpn.is_empty() {
tls["alpn"] = json!(connection.alpn);
}
if let Some(fingerprint) = &connection.fingerprint {
tls["fingerprint"] = json!(fingerprint);
}
json!({"log":{"loglevel":"none"},"inbounds":inbounds,"outbounds":[{"tag":"proxy","protocol":"trojan","settings":{"servers":[{"address":connection.host,"port":connection.port,"password":connection.password}]},"streamSettings":{"network":"tcp","security":"tls","tlsSettings":tls}}]})
}
pub fn write_config(path: &Path, value: &Value) -> Result<()> {
let (_, gid) = identity()?;
fs::create_dir_all(RUNTIME_DIR)?;
let directory = Path::new(RUNTIME_DIR);
fs::set_permissions(directory, fs::Permissions::from_mode(0o750))?;
std::os::unix::fs::chown(directory, Some(0), Some(gid))?;
crate::storage::atomic_private_write(path, &serde_json::to_vec(value)?)?;
std::os::unix::fs::chown(path, Some(0), Some(gid))?;
fs::set_permissions(path, fs::Permissions::from_mode(0o640))?;
Ok(())
}
pub async fn systemctl(args: &[&str]) -> Result<()> {
let status = tokio::time::timeout(
Duration::from_secs(30),
Command::new("/usr/bin/systemctl")
.args(args)
.stdin(Stdio::null())
.stdout(Stdio::null())
.stderr(Stdio::null())
.status(),
)
.await??;
ensure!(
status.success(),
"Service operation failed; inspect systemctl status for Roentgen"
);
Ok(())
}
pub struct Probe {
unit: String,
path: std::path::PathBuf,
pub proxy: String,
pub certificate: String,
active: bool,
}
impl Probe {
pub async fn start(connection: &Trojan, duration: u64) -> Result<Self> {
preflight().await?;
let listener = std::net::TcpListener::bind("127.0.0.1:0")?;
let port = listener.local_addr()?.port();
let token = uuid::Uuid::new_v4().simple().to_string();
let unit = format!("roentgen-probe-{token}");
let path = Path::new(RUNTIME_DIR).join(format!("{unit}.json"));
let certified = rcgen::generate_simple_self_signed(vec!["127.0.0.1".into()])?;
let certificate = certified.cert.pem();
let key = certified.key_pair.serialize_pem();
let mut configuration = configuration(connection, false);
configuration["inbounds"] = json!([{
"tag":"probe", "listen":"127.0.0.1", "port":port, "protocol":"http",
"settings":{"accounts":[{"user":"roentgen","pass":token}]},
"streamSettings":{"network":"tcp","security":"tls","tlsSettings":{"certificates":[{
"certificate":certificate.lines().collect::<Vec<_>>(), "key":key.lines().collect::<Vec<_>>()
}]}}
}]);
write_config(&path, &configuration)?;
drop(listener);
let runtime_limit = format!("RuntimeMaxSec={}", duration.saturating_add(10));
let probe = Self {
unit,
path,
proxy: format!("https://roentgen:{token}@127.0.0.1:{port}"),
certificate,
active: true,
};
let result = Command::new("/usr/bin/systemd-run")
.args([
"--quiet",
"--collect",
"--unit",
&probe.unit,
"--uid=roentgen-xray",
"--property=NoNewPrivileges=yes",
"--property=PrivateTmp=yes",
"--property=ProtectSystem=strict",
"--property=ProtectHome=yes",
"--property",
&runtime_limit,
"/usr/bin/xray",
"run",
"-config",
])
.arg(&probe.path)
.stdout(Stdio::null())
.stderr(Stdio::null())
.status()
.await;
if !result?.success() {
probe.stop().await;
anyhow::bail!("Could not launch protected Xray probe");
}
for _ in 0..50 {
if tokio::net::TcpStream::connect(("127.0.0.1", port))
.await
.is_ok()
{
return Ok(probe);
}
tokio::time::sleep(Duration::from_millis(20)).await;
}
probe.stop().await;
anyhow::bail!("Protected Xray probe did not start")
}
pub async fn stop(mut self) {
self.active = false;
let _ = systemctl(&["stop", &self.unit]).await;
let _ = fs::remove_file(&self.path);
}
}
impl Drop for Probe {
fn drop(&mut self) {
if !self.active {
return;
}
let unit = self.unit.clone();
let path = self.path.clone();
if let Ok(runtime) = tokio::runtime::Handle::try_current() {
runtime.spawn(async move {
let _ = systemctl(&["stop", &unit]).await;
let _ = fs::remove_file(path);
});
}
// systemd RuntimeMaxSec also bounds the process after controller death.
}
}
|
