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|
//! Glue between tunnel-obfuscation and WireGuard configurations
use super::{Error, Result};
use crate::{CloseMsg, config::Config};
#[cfg(target_os = "android")]
use std::sync::{Arc, Mutex};
use std::{
iter,
net::{Ipv4Addr, Ipv6Addr, SocketAddr},
sync::mpsc as sync_mpsc,
};
#[cfg(target_os = "android")]
use talpid_tunnel::tun_provider::TunProvider;
use talpid_types::{
ErrorExt,
net::obfuscation::{ObfuscatorConfig, Obfuscators},
};
use tunnel_obfuscation::{
Settings as ObfuscationSettings, create_obfuscator, lwo, multiplexer, quic, shadowsocks,
udp2tcp,
};
/// Begin running obfuscation machine, if configured. This function will patch `config`'s endpoint
/// to point to an endpoint on localhost
///
/// # Arguments
///
/// * obfuscation_mtu - "MTU" including obfuscation overhead
pub async fn apply_obfuscation_config(
config: &mut Config,
obfuscation_mtu: u16,
close_msg_sender: sync_mpsc::Sender<CloseMsg>,
#[cfg(target_os = "android")] tun_provider: Arc<Mutex<TunProvider>>,
) -> Result<Option<ObfuscatorHandle>> {
let Some(ref obfuscator_config) = config.obfuscator_config else {
return Ok(None);
};
let settings = settings_from_config(
config,
obfuscator_config,
obfuscation_mtu,
#[cfg(target_os = "linux")]
config.fwmark,
);
log::trace!("Obfuscation settings: {settings:?}");
let obfuscator = create_obfuscator(&settings)
.await
.map_err(Error::ObfuscationError)?;
let packet_overhead = obfuscator.packet_overhead();
#[cfg(target_os = "android")]
bypass_vpn(tun_provider, obfuscator.remote_socket_fd()).await;
patch_endpoint(config, obfuscator.endpoint());
let obfuscation_task = tokio::spawn(async move {
match obfuscator.run().await {
Ok(_) => {
let _ = close_msg_sender.send(CloseMsg::ObfuscatorExpired);
}
Err(error) => {
log::error!(
"{}",
error.display_chain_with_msg("Obfuscation controller failed")
);
let _ = close_msg_sender
.send(CloseMsg::ObfuscatorFailed(Error::ObfuscationError(error)));
}
}
});
Ok(Some(ObfuscatorHandle {
obfuscation_task,
packet_overhead,
}))
}
/// Patch the first peer in the WireGuard configuration to use the local proxy endpoint
fn patch_endpoint(config: &mut Config, endpoint: SocketAddr) {
log::trace!("Patching first WireGuard peer to become {endpoint}");
config.entry_peer.endpoint = endpoint;
}
fn settings_from_config(
config: &Config,
obfuscation_config: &Obfuscators,
mtu: u16,
#[cfg(target_os = "linux")] fwmark: Option<u32>,
) -> ObfuscationSettings {
match obfuscation_config {
Obfuscators::Single(obfuscation_config) => settings_from_single_config(
config,
obfuscation_config,
mtu,
#[cfg(target_os = "linux")]
fwmark,
),
Obfuscators::Multiplexer {
direct,
configs: (first_obfs, remaining_obfs),
} => {
let mut transports = vec![];
if let Some(direct) = direct {
transports.push(multiplexer::Transport::Direct(*direct));
}
for obfs_config in iter::once(first_obfs).chain(remaining_obfs) {
let settings = settings_from_single_config(
config,
obfs_config,
mtu,
#[cfg(target_os = "linux")]
fwmark,
);
transports.push(multiplexer::Transport::Obfuscated(settings));
}
ObfuscationSettings::Multiplexer(multiplexer::Settings {
transports,
#[cfg(target_os = "linux")]
fwmark,
})
}
}
}
fn settings_from_single_config(
config: &Config,
obfuscation_config: &ObfuscatorConfig,
mtu: u16,
#[cfg(target_os = "linux")] fwmark: Option<u32>,
) -> ObfuscationSettings {
match obfuscation_config {
ObfuscatorConfig::Udp2Tcp { endpoint } => ObfuscationSettings::Udp2Tcp(udp2tcp::Settings {
peer: *endpoint,
#[cfg(target_os = "linux")]
fwmark,
}),
ObfuscatorConfig::Shadowsocks { endpoint } => {
ObfuscationSettings::Shadowsocks(shadowsocks::Settings {
shadowsocks_endpoint: *endpoint,
wireguard_endpoint: if endpoint.is_ipv4() {
SocketAddr::from((Ipv4Addr::LOCALHOST, 51820))
} else {
SocketAddr::from((Ipv6Addr::LOCALHOST, 51820))
},
#[cfg(target_os = "linux")]
fwmark,
})
}
ObfuscatorConfig::Quic {
hostname,
endpoint,
auth_token,
} => {
let wireguard_endpoint = SocketAddr::from((Ipv4Addr::LOCALHOST, 51820));
let settings = quic::Settings::new(
*endpoint,
hostname.to_owned(),
auth_token.parse().unwrap(),
wireguard_endpoint,
)
.mtu(mtu);
#[cfg(target_os = "linux")]
if let Some(fwmark) = fwmark {
return ObfuscationSettings::Quic(settings.fwmark(fwmark));
}
ObfuscationSettings::Quic(settings)
}
ObfuscatorConfig::Lwo { endpoint } => ObfuscationSettings::Lwo(lwo::Settings {
server_addr: *endpoint,
client_public_key: config.tunnel.private_key.public_key(),
server_public_key: config.entry_peer.public_key.clone(),
#[cfg(target_os = "linux")]
fwmark,
}),
}
}
/// Route socket outside of the VPN on Android
#[cfg(target_os = "android")]
async fn bypass_vpn(
tun_provider: Arc<Mutex<TunProvider>>,
remote_socket_fd: std::os::unix::io::RawFd,
) {
// Exclude remote obfuscation socket or bridge
log::debug!("Excluding remote socket fd from the tunnel");
let _ = tokio::task::spawn_blocking(move || {
if let Err(error) = tun_provider.lock().unwrap().bypass(&remote_socket_fd) {
log::error!("Failed to exclude remote socket fd: {error}");
}
})
.await;
}
/// Simple wrapper that automatically cancels the future which runs an obfuscator.
pub struct ObfuscatorHandle {
obfuscation_task: tokio::task::JoinHandle<()>,
packet_overhead: u16,
}
impl ObfuscatorHandle {
pub fn abort(&self) {
self.obfuscation_task.abort();
}
pub fn packet_overhead(&self) -> u16 {
self.packet_overhead
}
}
impl Drop for ObfuscatorHandle {
fn drop(&mut self) {
self.obfuscation_task.abort();
}
}
|
