ostp/ostp-tun/src/linux.rs

107 lines
4.2 KiB
Rust

use crate::{OstpTunInterface, OstpTunOptions};
use anyhow::{anyhow, Result};
use std::process::Command;
struct LinuxRouteGuard {
server_ip: String,
bypass_routes: Vec<String>,
real_gw: Option<String>,
real_dev: Option<String>,
kill_switch: bool,
}
impl Drop for LinuxRouteGuard {
fn drop(&mut self) {
let _ = Command::new("ip").args(["route", "del", "0.0.0.0/1", "dev", "ostp_tun"]).output();
let _ = Command::new("ip").args(["route", "del", "128.0.0.0/1", "dev", "ostp_tun"]).output();
let _ = Command::new("ip").args(["route", "del", "default", "dev", "ostp_tun"]).output();
let _ = Command::new("ip").args(["route", "del", &format!("{}/32", self.server_ip)]).output();
for route in &self.bypass_routes {
let _ = Command::new("ip").args(["route", "del", route]).output();
}
tracing::info!("Removed Linux bypass routes.");
if self.kill_switch {
if let (Some(ref gw), Some(ref dev)) = (&self.real_gw, &self.real_dev) {
let _ = Command::new("ip").args(["route", "add", "default", "via", gw, "dev", dev]).output();
tracing::info!("Restored original default route via {} dev {}", gw, dev);
}
}
}
}
pub async fn create(opts: OstpTunOptions) -> Result<OstpTunInterface> {
let mut tun_cfg = tun::Configuration::default();
tun_cfg
.tun_name("ostp_tun")
.address((10, 1, 0, 2))
.netmask((255, 255, 255, 0))
.destination((10, 1, 0, 1))
.mtu(opts.mtu)
.up();
let dev = tun::create(&tun_cfg).map_err(|e| anyhow!("Failed to create TUN device: {}", e))?;
let dev = tun::AsyncDevice::new(dev).map_err(|e| anyhow!("TUN device async failed: {}", e))?;
tracing::info!("TUN device 'ostp_tun' created.");
let gw_out = Command::new("ip")
.args(["route", "show", "default"])
.output()
.ok()
.and_then(|o| String::from_utf8(o.stdout).ok());
let real_gw = gw_out.as_deref().and_then(|s| {
s.split_whitespace().skip_while(|w| *w != "via").nth(1).map(|s| s.to_string())
});
let real_dev = gw_out.as_deref().and_then(|s| {
s.split_whitespace().skip_while(|w| *w != "dev").nth(1).map(|s| s.to_string())
});
let mut bypass_routes = Vec::new();
if let (Some(ref gw), Some(ref dev_name)) = (&real_gw, &real_dev) {
let server_ip_str = opts.server_ip.to_string();
let _ = Command::new("ip")
.args(["route", "add", &format!("{}/32", server_ip_str), "via", gw, "dev", dev_name])
.output();
tracing::info!("Added bypass route for server {} via {}", server_ip_str, gw);
for ip in &opts.bypass_ips {
let route = format!("{}/32", ip);
let _ = Command::new("ip").args(["route", "add", &route, "via", gw, "dev", dev_name]).output();
bypass_routes.push(route);
}
// Override default route gracefully by adding more specific /1 routes
let _ = Command::new("ip").args(["route", "add", "0.0.0.0/1", "dev", "ostp_tun"]).output();
let _ = Command::new("ip").args(["route", "add", "128.0.0.0/1", "dev", "ostp_tun"]).output();
if opts.kill_switch {
tracing::info!("Kill Switch: deleting original default route to prevent leakage.");
let _ = Command::new("ip").args(["route", "del", "default", "via", gw, "dev", dev_name]).output();
}
} else {
tracing::warn!("Could not detect physical default gateway. Tunnel routing might not work correctly.");
}
if let Some(ref dns) = opts.dns_server {
if !dns.is_empty() {
let _ = Command::new("resolvectl").args(["dns", "ostp_tun", dns]).output();
let _ = Command::new("resolvectl").args(["domain", "ostp_tun", "~."]).output();
let _ = Command::new("resolvectl").args(["default-route", "ostp_tun", "true"]).output();
tracing::info!("Configured DNS via resolvectl for ostp_tun: {}", dns);
}
}
Ok(OstpTunInterface {
device: dev,
guard: Box::new(LinuxRouteGuard {
server_ip: opts.server_ip.to_string(),
bypass_routes,
real_gw,
real_dev,
kill_switch: opts.kill_switch,
}),
})
}