Line data Source code
1 : /// A stand-alone program that routes connections, e.g. from
2 : /// `aaa--bbb--1234.external.domain` to `aaa.bbb.internal.domain:1234`.
3 : ///
4 : /// This allows connecting to pods/services running in the same Kubernetes cluster from
5 : /// the outside. Similar to an ingress controller for HTTPS.
6 : use std::{net::SocketAddr, sync::Arc};
7 :
8 : use anyhow::{anyhow, bail, ensure, Context};
9 : use clap::Arg;
10 : use futures::future::Either;
11 : use futures::TryFutureExt;
12 : use itertools::Itertools;
13 : use rustls::crypto::ring;
14 : use rustls::pki_types::PrivateKeyDer;
15 : use tokio::io::{AsyncRead, AsyncWrite};
16 : use tokio::net::TcpListener;
17 : use tokio_util::sync::CancellationToken;
18 : use tracing::{error, info, Instrument};
19 : use utils::project_git_version;
20 : use utils::sentry_init::init_sentry;
21 :
22 : use crate::context::RequestContext;
23 : use crate::metrics::{Metrics, ThreadPoolMetrics};
24 : use crate::protocol2::ConnectionInfo;
25 : use crate::proxy::{copy_bidirectional_client_compute, run_until_cancelled, ErrorSource};
26 : use crate::stream::{PqStream, Stream};
27 : use crate::tls::TlsServerEndPoint;
28 :
29 : project_git_version!(GIT_VERSION);
30 :
31 0 : fn cli() -> clap::Command {
32 0 : clap::Command::new("Neon proxy/router")
33 0 : .version(GIT_VERSION)
34 0 : .arg(
35 0 : Arg::new("listen")
36 0 : .short('l')
37 0 : .long("listen")
38 0 : .help("listen for incoming client connections on ip:port")
39 0 : .default_value("127.0.0.1:4432"),
40 0 : )
41 0 : .arg(
42 0 : Arg::new("tls-key")
43 0 : .short('k')
44 0 : .long("tls-key")
45 0 : .help("path to TLS key for client postgres connections")
46 0 : .required(true),
47 0 : )
48 0 : .arg(
49 0 : Arg::new("tls-cert")
50 0 : .short('c')
51 0 : .long("tls-cert")
52 0 : .help("path to TLS cert for client postgres connections")
53 0 : .required(true),
54 0 : )
55 0 : .arg(
56 0 : Arg::new("dest")
57 0 : .short('d')
58 0 : .long("destination")
59 0 : .help("append this domain zone to the SNI hostname to get the destination address")
60 0 : .required(true),
61 0 : )
62 0 : }
63 :
64 0 : pub async fn run() -> anyhow::Result<()> {
65 0 : let _logging_guard = crate::logging::init().await?;
66 0 : let _panic_hook_guard = utils::logging::replace_panic_hook_with_tracing_panic_hook();
67 0 : let _sentry_guard = init_sentry(Some(GIT_VERSION.into()), &[]);
68 0 :
69 0 : Metrics::install(Arc::new(ThreadPoolMetrics::new(0)));
70 0 :
71 0 : let args = cli().get_matches();
72 0 : let destination: String = args
73 0 : .get_one::<String>("dest")
74 0 : .expect("string argument defined")
75 0 : .parse()?;
76 :
77 : // Configure TLS
78 0 : let (tls_config, tls_server_end_point): (Arc<rustls::ServerConfig>, TlsServerEndPoint) = match (
79 0 : args.get_one::<String>("tls-key"),
80 0 : args.get_one::<String>("tls-cert"),
81 : ) {
82 0 : (Some(key_path), Some(cert_path)) => {
83 0 : let key = {
84 0 : let key_bytes = std::fs::read(key_path).context("TLS key file")?;
85 :
86 0 : let mut keys =
87 0 : rustls_pemfile::pkcs8_private_keys(&mut &key_bytes[..]).collect_vec();
88 0 :
89 0 : ensure!(keys.len() == 1, "keys.len() = {} (should be 1)", keys.len());
90 : PrivateKeyDer::Pkcs8(
91 0 : keys.pop()
92 0 : .expect("keys should not be empty")
93 0 : .context(format!("Failed to read TLS keys at '{key_path}'"))?,
94 : )
95 : };
96 :
97 0 : let cert_chain_bytes = std::fs::read(cert_path)
98 0 : .context(format!("Failed to read TLS cert file at '{cert_path}.'"))?;
99 :
100 0 : let cert_chain: Vec<_> = {
101 0 : rustls_pemfile::certs(&mut &cert_chain_bytes[..])
102 0 : .try_collect()
103 0 : .with_context(|| {
104 0 : format!("Failed to read TLS certificate chain from bytes from file at '{cert_path}'.")
105 0 : })?
106 : };
107 :
108 : // needed for channel bindings
109 0 : let first_cert = cert_chain.first().context("missing certificate")?;
110 0 : let tls_server_end_point = TlsServerEndPoint::new(first_cert)?;
111 :
112 0 : let tls_config =
113 0 : rustls::ServerConfig::builder_with_provider(Arc::new(ring::default_provider()))
114 0 : .with_protocol_versions(&[&rustls::version::TLS13, &rustls::version::TLS12])
115 0 : .context("ring should support TLS1.2 and TLS1.3")?
116 0 : .with_no_client_auth()
117 0 : .with_single_cert(cert_chain, key)?
118 0 : .into();
119 0 :
120 0 : (tls_config, tls_server_end_point)
121 : }
122 0 : _ => bail!("tls-key and tls-cert must be specified"),
123 : };
124 :
125 : // Start listening for incoming client connections
126 0 : let proxy_address: SocketAddr = args
127 0 : .get_one::<String>("listen")
128 0 : .expect("string argument defined")
129 0 : .parse()?;
130 0 : info!("Starting sni router on {proxy_address}");
131 0 : let proxy_listener = TcpListener::bind(proxy_address).await?;
132 :
133 0 : let cancellation_token = CancellationToken::new();
134 0 :
135 0 : let main = tokio::spawn(task_main(
136 0 : Arc::new(destination),
137 0 : tls_config,
138 0 : tls_server_end_point,
139 0 : proxy_listener,
140 0 : cancellation_token.clone(),
141 0 : ));
142 0 : let signals_task = tokio::spawn(crate::signals::handle(cancellation_token, || {}));
143 0 :
144 0 : // the signal task cant ever succeed.
145 0 : // the main task can error, or can succeed on cancellation.
146 0 : // we want to immediately exit on either of these cases
147 0 : let signal = match futures::future::select(signals_task, main).await {
148 0 : Either::Left((res, _)) => crate::error::flatten_err(res)?,
149 0 : Either::Right((res, _)) => return crate::error::flatten_err(res),
150 : };
151 :
152 : // maintenance tasks return `Infallible` success values, this is an impossible value
153 : // so this match statically ensures that there are no possibilities for that value
154 : match signal {}
155 0 : }
156 :
157 0 : async fn task_main(
158 0 : dest_suffix: Arc<String>,
159 0 : tls_config: Arc<rustls::ServerConfig>,
160 0 : tls_server_end_point: TlsServerEndPoint,
161 0 : listener: tokio::net::TcpListener,
162 0 : cancellation_token: CancellationToken,
163 0 : ) -> anyhow::Result<()> {
164 0 : // When set for the server socket, the keepalive setting
165 0 : // will be inherited by all accepted client sockets.
166 0 : socket2::SockRef::from(&listener).set_keepalive(true)?;
167 :
168 0 : let connections = tokio_util::task::task_tracker::TaskTracker::new();
169 :
170 0 : while let Some(accept_result) =
171 0 : run_until_cancelled(listener.accept(), &cancellation_token).await
172 : {
173 0 : let (socket, peer_addr) = accept_result?;
174 :
175 0 : let session_id = uuid::Uuid::new_v4();
176 0 : let tls_config = Arc::clone(&tls_config);
177 0 : let dest_suffix = Arc::clone(&dest_suffix);
178 0 :
179 0 : connections.spawn(
180 0 : async move {
181 0 : socket
182 0 : .set_nodelay(true)
183 0 : .context("failed to set socket option")?;
184 :
185 0 : info!(%peer_addr, "serving");
186 0 : let ctx = RequestContext::new(
187 0 : session_id,
188 0 : ConnectionInfo {
189 0 : addr: peer_addr,
190 0 : extra: None,
191 0 : },
192 0 : crate::metrics::Protocol::SniRouter,
193 0 : "sni",
194 0 : );
195 0 : handle_client(ctx, dest_suffix, tls_config, tls_server_end_point, socket).await
196 0 : }
197 0 : .unwrap_or_else(|e| {
198 0 : // Acknowledge that the task has finished with an error.
199 0 : error!("per-client task finished with an error: {e:#}");
200 0 : })
201 0 : .instrument(tracing::info_span!("handle_client", ?session_id)),
202 : );
203 : }
204 :
205 0 : connections.close();
206 0 : drop(listener);
207 0 :
208 0 : connections.wait().await;
209 :
210 0 : info!("all client connections have finished");
211 0 : Ok(())
212 0 : }
213 :
214 : const ERR_INSECURE_CONNECTION: &str = "connection is insecure (try using `sslmode=require`)";
215 :
216 0 : async fn ssl_handshake<S: AsyncRead + AsyncWrite + Unpin>(
217 0 : ctx: &RequestContext,
218 0 : raw_stream: S,
219 0 : tls_config: Arc<rustls::ServerConfig>,
220 0 : tls_server_end_point: TlsServerEndPoint,
221 0 : ) -> anyhow::Result<Stream<S>> {
222 0 : let mut stream = PqStream::new(Stream::from_raw(raw_stream));
223 :
224 0 : let msg = stream.read_startup_packet().await?;
225 : use pq_proto::FeStartupPacket::SslRequest;
226 :
227 0 : match msg {
228 : SslRequest { direct: false } => {
229 0 : stream
230 0 : .write_message(&pq_proto::BeMessage::EncryptionResponse(true))
231 0 : .await?;
232 :
233 : // Upgrade raw stream into a secure TLS-backed stream.
234 : // NOTE: We've consumed `tls`; this fact will be used later.
235 :
236 0 : let (raw, read_buf) = stream.into_inner();
237 0 : // TODO: Normally, client doesn't send any data before
238 0 : // server says TLS handshake is ok and read_buf is empty.
239 0 : // However, you could imagine pipelining of postgres
240 0 : // SSLRequest + TLS ClientHello in one hunk similar to
241 0 : // pipelining in our node js driver. We should probably
242 0 : // support that by chaining read_buf with the stream.
243 0 : if !read_buf.is_empty() {
244 0 : bail!("data is sent before server replied with EncryptionResponse");
245 0 : }
246 0 :
247 0 : Ok(Stream::Tls {
248 0 : tls: Box::new(
249 0 : raw.upgrade(tls_config, !ctx.has_private_peer_addr())
250 0 : .await?,
251 : ),
252 0 : tls_server_end_point,
253 : })
254 : }
255 0 : unexpected => {
256 0 : info!(
257 : ?unexpected,
258 0 : "unexpected startup packet, rejecting connection"
259 : );
260 0 : stream
261 0 : .throw_error_str(ERR_INSECURE_CONNECTION, crate::error::ErrorKind::User)
262 0 : .await?
263 : }
264 : }
265 0 : }
266 :
267 0 : async fn handle_client(
268 0 : ctx: RequestContext,
269 0 : dest_suffix: Arc<String>,
270 0 : tls_config: Arc<rustls::ServerConfig>,
271 0 : tls_server_end_point: TlsServerEndPoint,
272 0 : stream: impl AsyncRead + AsyncWrite + Unpin,
273 0 : ) -> anyhow::Result<()> {
274 0 : let mut tls_stream = ssl_handshake(&ctx, stream, tls_config, tls_server_end_point).await?;
275 :
276 : // Cut off first part of the SNI domain
277 : // We receive required destination details in the format of
278 : // `{k8s_service_name}--{k8s_namespace}--{port}.non-sni-domain`
279 0 : let sni = tls_stream.sni_hostname().ok_or(anyhow!("SNI missing"))?;
280 0 : let dest: Vec<&str> = sni
281 0 : .split_once('.')
282 0 : .context("invalid SNI")?
283 : .0
284 0 : .splitn(3, "--")
285 0 : .collect();
286 0 : let port = dest[2].parse::<u16>().context("invalid port")?;
287 0 : let destination = format!("{}.{}.{}:{}", dest[0], dest[1], dest_suffix, port);
288 0 :
289 0 : info!("destination: {}", destination);
290 :
291 0 : let mut client = tokio::net::TcpStream::connect(destination).await?;
292 :
293 : // doesn't yet matter as pg-sni-router doesn't report analytics logs
294 0 : ctx.set_success();
295 0 : ctx.log_connect();
296 0 :
297 0 : // Starting from here we only proxy the client's traffic.
298 0 : info!("performing the proxy pass...");
299 :
300 0 : match copy_bidirectional_client_compute(&mut tls_stream, &mut client).await {
301 0 : Ok(_) => Ok(()),
302 0 : Err(ErrorSource::Client(err)) => Err(err).context("client"),
303 0 : Err(ErrorSource::Compute(err)) => Err(err).context("compute"),
304 : }
305 0 : }
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