1use std::net::SocketAddr;
2
3use hopr_lib::{HoprOffchainKeypair, ServiceId, errors::HoprLibError, transfer_session};
4use hopr_network_types::{prelude::ForeignDataMode, udp::UdpStreamParallelism};
5use hoprd_api::{HOPR_TCP_BUFFER_SIZE, HOPR_UDP_BUFFER_SIZE, HOPR_UDP_QUEUE_SIZE};
6
7use crate::config::SessionIpForwardingConfig;
8
9#[cfg(all(feature = "prometheus", not(test)))]
10lazy_static::lazy_static! {
11 static ref METRIC_ACTIVE_TARGETS: hopr_metrics::MultiGauge = hopr_metrics::MultiGauge::new(
12 "hopr_session_hoprd_target_connections",
13 "Number of currently active HOPR session target connections on this Exit node",
14 &["type"]
15 ).unwrap();
16}
17
18#[derive(Debug, Clone)]
21pub struct HoprServerIpForwardingReactor {
22 keypair: HoprOffchainKeypair,
23 cfg: SessionIpForwardingConfig,
24}
25
26impl HoprServerIpForwardingReactor {
27 pub fn new(keypair: HoprOffchainKeypair, cfg: SessionIpForwardingConfig) -> Self {
28 Self { keypair, cfg }
29 }
30
31 fn all_ips_allowed(&self, addrs: &[SocketAddr]) -> bool {
32 if self.cfg.use_target_allow_list {
33 for addr in addrs {
34 if !self.cfg.target_allow_list.contains(addr) {
35 tracing::error!(%addr, "address not allowed by the target allow list, denying the target");
36 return false;
37 }
38 tracing::debug!(%addr, "address allowed by the target allow list, accepting the target");
39 }
40 }
41 true
42 }
43}
44
45pub const SERVICE_ID_LOOPBACK: ServiceId = 0;
46
47#[hopr_lib::async_trait]
48impl hopr_lib::HoprSessionReactor for HoprServerIpForwardingReactor {
49 #[tracing::instrument(level = "debug", skip(self, session))]
50 async fn process(&self, mut session: hopr_lib::HoprIncomingSession) -> hopr_lib::errors::Result<()> {
51 let session_id = *session.session.id();
52 match session.target {
53 hopr_lib::SessionTarget::UdpStream(udp_target) => {
54 let kp = self.keypair.clone();
55 let udp_target = hopr_parallelize::cpu::spawn_blocking(move || udp_target.unseal(&kp))
56 .await
57 .map_err(|e| HoprLibError::GeneralError(format!("cannot unseal target: {e}")))?;
58
59 tracing::debug!(
60 session_id = ?session_id,
61 %udp_target,
62 "binding socket to the UDP server"
63 );
64
65 let resolved_udp_target = udp_target
68 .clone()
69 .resolve_tokio()
70 .await
71 .map_err(|e| HoprLibError::GeneralError(format!("failed to resolve DNS name {udp_target}: {e}")))?
72 .first()
73 .ok_or(HoprLibError::GeneralError(format!(
74 "failed to resolve DNS name {udp_target}"
75 )))?
76 .to_owned();
77 tracing::debug!(
78 ?session_id,
79 %udp_target,
80 resolution = ?resolved_udp_target,
81 "UDP target resolved"
82 );
83
84 if !self.all_ips_allowed(&[resolved_udp_target]) {
85 return Err(HoprLibError::GeneralError(format!(
86 "denied target address {resolved_udp_target}"
87 )));
88 }
89
90 let mut udp_bridge = hopr_network_types::udp::ConnectedUdpStream::builder()
91 .with_buffer_size(HOPR_UDP_BUFFER_SIZE)
92 .with_counterparty(resolved_udp_target)
93 .with_foreign_data_mode(ForeignDataMode::Error)
94 .with_queue_size(HOPR_UDP_QUEUE_SIZE)
95 .with_receiver_parallelism(UdpStreamParallelism::Auto)
96 .build(("0.0.0.0", 0))
97 .map_err(|e| {
98 HoprLibError::GeneralError(format!(
99 "could not bridge the incoming session to {udp_target}: {e}"
100 ))
101 })?;
102
103 tracing::debug!(
104 ?session_id,
105 %udp_target,
106 "bridging the session to the UDP server"
107 );
108
109 tokio::task::spawn(async move {
110 #[cfg(all(feature = "prometheus", not(test)))]
111 METRIC_ACTIVE_TARGETS.increment(&["udp"], 1.0);
112
113 match transfer_session(&mut session.session, &mut udp_bridge, HOPR_UDP_BUFFER_SIZE, None).await {
116 Ok((session_to_stream_bytes, stream_to_session_bytes)) => tracing::info!(
117 ?session_id,
118 session_to_stream_bytes,
119 stream_to_session_bytes,
120 %udp_target,
121 "server bridged session to UDP ended"
122 ),
123 Err(e) => tracing::error!(
124 ?session_id,
125 %udp_target,
126 error = %e,
127 "UDP server stream is closed"
128 ),
129 }
130
131 #[cfg(all(feature = "prometheus", not(test)))]
132 METRIC_ACTIVE_TARGETS.decrement(&["udp"], 1.0);
133 });
134
135 Ok(())
136 }
137 hopr_lib::SessionTarget::TcpStream(tcp_target) => {
138 let kp = self.keypair.clone();
139 let tcp_target = hopr_parallelize::cpu::spawn_blocking(move || tcp_target.unseal(&kp))
140 .await
141 .map_err(|e| HoprLibError::GeneralError(format!("cannot unseal target: {e}")))?;
142
143 tracing::debug!(?session_id, %tcp_target, "creating a connection to the TCP server");
144
145 let resolved_tcp_targets =
148 tcp_target.clone().resolve_tokio().await.map_err(|e| {
149 HoprLibError::GeneralError(format!("failed to resolve DNS name {tcp_target}: {e}"))
150 })?;
151 tracing::debug!(
152 ?session_id,
153 %tcp_target,
154 resolution = ?resolved_tcp_targets,
155 "TCP target resolved"
156 );
157
158 if !self.all_ips_allowed(&resolved_tcp_targets) {
159 return Err(HoprLibError::GeneralError(format!(
160 "denied target address {resolved_tcp_targets:?}"
161 )));
162 }
163
164 let strategy = tokio_retry::strategy::FixedInterval::new(self.cfg.tcp_target_retry_delay)
165 .take(self.cfg.max_tcp_target_retries as usize);
166
167 let mut tcp_bridge = tokio_retry::Retry::spawn(strategy, || {
168 tokio::net::TcpStream::connect(resolved_tcp_targets.as_slice())
169 })
170 .await
171 .map_err(|e| {
172 HoprLibError::GeneralError(format!("could not bridge the incoming session to {tcp_target}: {e}"))
173 })?;
174
175 tcp_bridge.set_nodelay(true).map_err(|e| {
176 HoprLibError::GeneralError(format!(
177 "could not set the TCP_NODELAY option for the bridged session to {tcp_target}: {e}",
178 ))
179 })?;
180
181 tracing::debug!(
182 ?session_id,
183 %tcp_target,
184 "bridging the session to the TCP server"
185 );
186 tokio::task::spawn(async move {
187 #[cfg(all(feature = "prometheus", not(test)))]
188 METRIC_ACTIVE_TARGETS.increment(&["tcp"], 1.0);
189
190 match transfer_session(&mut session.session, &mut tcp_bridge, HOPR_TCP_BUFFER_SIZE, None).await {
191 Ok((session_to_stream_bytes, stream_to_session_bytes)) => tracing::info!(
192 ?session_id,
193 session_to_stream_bytes,
194 stream_to_session_bytes,
195 %tcp_target,
196 "server bridged session to TCP ended"
197 ),
198 Err(error) => tracing::error!(
199 ?session_id,
200 %tcp_target,
201 %error,
202 "TCP server stream is closed"
203 ),
204 }
205
206 #[cfg(all(feature = "prometheus", not(test)))]
207 METRIC_ACTIVE_TARGETS.decrement(&["tcp"], 1.0);
208 });
209
210 Ok(())
211 }
212 hopr_lib::SessionTarget::ExitNode(SERVICE_ID_LOOPBACK) => {
213 tracing::debug!(?session_id, "bridging the session to the loopback service");
214 let (mut reader, mut writer) = tokio::io::split(session.session);
215
216 #[cfg(all(feature = "prometheus", not(test)))]
217 METRIC_ACTIVE_TARGETS.increment(&["loopback"], 1.0);
218
219 match tokio::io::copy(&mut reader, &mut writer).await {
221 Ok(copied) => tracing::info!(?session_id, copied, "server loopback session service ended"),
222 Err(error) => tracing::error!(
223 ?session_id,
224 %error,
225 "server loopback session service ended with an error"
226 ),
227 }
228
229 #[cfg(all(feature = "prometheus", not(test)))]
230 METRIC_ACTIVE_TARGETS.decrement(&["loopback"], 1.0);
231
232 Ok(())
233 }
234 hopr_lib::SessionTarget::ExitNode(_) => Err(HoprLibError::GeneralError(
235 "server does not support internal session processing".into(),
236 )),
237 }
238 }
239}