Line data Source code
1 : use std::io;
2 : use std::net::SocketAddr;
3 : use std::time::Duration;
4 :
5 : use futures::{FutureExt, TryFutureExt};
6 : use itertools::Itertools;
7 : use postgres_client::tls::MakeTlsConnect;
8 : use postgres_client::{CancelToken, RawConnection};
9 : use postgres_protocol::message::backend::NoticeResponseBody;
10 : use pq_proto::StartupMessageParams;
11 : use rustls::pki_types::InvalidDnsNameError;
12 : use thiserror::Error;
13 : use tokio::net::TcpStream;
14 : use tracing::{debug, error, info, warn};
15 :
16 : use crate::auth::backend::ComputeUserInfo;
17 : use crate::auth::parse_endpoint_param;
18 : use crate::cancellation::CancelClosure;
19 : use crate::config::ComputeConfig;
20 : use crate::context::RequestContext;
21 : use crate::control_plane::client::ApiLockError;
22 : use crate::control_plane::errors::WakeComputeError;
23 : use crate::control_plane::messages::MetricsAuxInfo;
24 : use crate::error::{ReportableError, UserFacingError};
25 : use crate::metrics::{Metrics, NumDbConnectionsGuard};
26 : use crate::proxy::neon_option;
27 : use crate::tls::postgres_rustls::MakeRustlsConnect;
28 : use crate::types::Host;
29 :
30 : pub const COULD_NOT_CONNECT: &str = "Couldn't connect to compute node";
31 :
32 : #[derive(Debug, Error)]
33 : pub(crate) enum ConnectionError {
34 : /// This error doesn't seem to reveal any secrets; for instance,
35 : /// `postgres_client::error::Kind` doesn't contain ip addresses and such.
36 : #[error("{COULD_NOT_CONNECT}: {0}")]
37 : Postgres(#[from] postgres_client::Error),
38 :
39 : #[error("{COULD_NOT_CONNECT}: {0}")]
40 : CouldNotConnect(#[from] io::Error),
41 :
42 : #[error("{COULD_NOT_CONNECT}: {0}")]
43 : TlsError(#[from] InvalidDnsNameError),
44 :
45 : #[error("{COULD_NOT_CONNECT}: {0}")]
46 : WakeComputeError(#[from] WakeComputeError),
47 :
48 : #[error("error acquiring resource permit: {0}")]
49 : TooManyConnectionAttempts(#[from] ApiLockError),
50 : }
51 :
52 : impl UserFacingError for ConnectionError {
53 0 : fn to_string_client(&self) -> String {
54 0 : match self {
55 : // This helps us drop irrelevant library-specific prefixes.
56 : // TODO: propagate severity level and other parameters.
57 0 : ConnectionError::Postgres(err) => match err.as_db_error() {
58 0 : Some(err) => {
59 0 : let msg = err.message();
60 0 :
61 0 : if msg.starts_with("unsupported startup parameter: ")
62 0 : || msg.starts_with("unsupported startup parameter in options: ")
63 : {
64 0 : format!("{msg}. Please use unpooled connection or remove this parameter from the startup package. More details: https://neon.tech/docs/connect/connection-errors#unsupported-startup-parameter")
65 : } else {
66 0 : msg.to_owned()
67 : }
68 : }
69 0 : None => err.to_string(),
70 : },
71 0 : ConnectionError::WakeComputeError(err) => err.to_string_client(),
72 : ConnectionError::TooManyConnectionAttempts(_) => {
73 0 : "Failed to acquire permit to connect to the database. Too many database connection attempts are currently ongoing.".to_owned()
74 : }
75 0 : _ => COULD_NOT_CONNECT.to_owned(),
76 : }
77 0 : }
78 : }
79 :
80 : impl ReportableError for ConnectionError {
81 0 : fn get_error_kind(&self) -> crate::error::ErrorKind {
82 0 : match self {
83 0 : ConnectionError::Postgres(e) if e.as_db_error().is_some() => {
84 0 : crate::error::ErrorKind::Postgres
85 : }
86 0 : ConnectionError::Postgres(_) => crate::error::ErrorKind::Compute,
87 0 : ConnectionError::CouldNotConnect(_) => crate::error::ErrorKind::Compute,
88 0 : ConnectionError::TlsError(_) => crate::error::ErrorKind::Compute,
89 0 : ConnectionError::WakeComputeError(e) => e.get_error_kind(),
90 0 : ConnectionError::TooManyConnectionAttempts(e) => e.get_error_kind(),
91 : }
92 0 : }
93 : }
94 :
95 : /// A pair of `ClientKey` & `ServerKey` for `SCRAM-SHA-256`.
96 : pub(crate) type ScramKeys = postgres_client::config::ScramKeys<32>;
97 :
98 : /// A config for establishing a connection to compute node.
99 : /// Eventually, `postgres_client` will be replaced with something better.
100 : /// Newtype allows us to implement methods on top of it.
101 : #[derive(Clone)]
102 : pub(crate) struct ConnCfg(Box<postgres_client::Config>);
103 :
104 : /// Creation and initialization routines.
105 : impl ConnCfg {
106 10 : pub(crate) fn new(host: String, port: u16) -> Self {
107 10 : Self(Box::new(postgres_client::Config::new(host, port)))
108 10 : }
109 :
110 : /// Reuse password or auth keys from the other config.
111 4 : pub(crate) fn reuse_password(&mut self, other: Self) {
112 4 : if let Some(password) = other.get_password() {
113 4 : self.password(password);
114 4 : }
115 :
116 4 : if let Some(keys) = other.get_auth_keys() {
117 0 : self.auth_keys(keys);
118 4 : }
119 4 : }
120 :
121 0 : pub(crate) fn get_host(&self) -> Host {
122 0 : match self.0.get_host() {
123 0 : postgres_client::config::Host::Tcp(s) => s.into(),
124 0 : }
125 0 : }
126 :
127 : /// Apply startup message params to the connection config.
128 0 : pub(crate) fn set_startup_params(
129 0 : &mut self,
130 0 : params: &StartupMessageParams,
131 0 : arbitrary_params: bool,
132 0 : ) {
133 0 : if !arbitrary_params {
134 0 : self.set_param("client_encoding", "UTF8");
135 0 : }
136 0 : for (k, v) in params.iter() {
137 0 : match k {
138 : // Only set `user` if it's not present in the config.
139 : // Console redirect auth flow takes username from the console's response.
140 0 : "user" if self.user_is_set() => {}
141 0 : "database" if self.db_is_set() => {}
142 0 : "options" => {
143 0 : if let Some(options) = filtered_options(v) {
144 0 : self.set_param(k, &options);
145 0 : }
146 : }
147 0 : "user" | "database" | "application_name" | "replication" => {
148 0 : self.set_param(k, v);
149 0 : }
150 :
151 : // if we allow arbitrary params, then we forward them through.
152 : // this is a flag for a period of backwards compatibility
153 0 : k if arbitrary_params => {
154 0 : self.set_param(k, v);
155 0 : }
156 0 : _ => {}
157 : }
158 : }
159 0 : }
160 : }
161 :
162 : impl std::ops::Deref for ConnCfg {
163 : type Target = postgres_client::Config;
164 :
165 8 : fn deref(&self) -> &Self::Target {
166 8 : &self.0
167 8 : }
168 : }
169 :
170 : /// For now, let's make it easier to setup the config.
171 : impl std::ops::DerefMut for ConnCfg {
172 10 : fn deref_mut(&mut self) -> &mut Self::Target {
173 10 : &mut self.0
174 10 : }
175 : }
176 :
177 : impl ConnCfg {
178 : /// Establish a raw TCP connection to the compute node.
179 0 : async fn connect_raw(&self, timeout: Duration) -> io::Result<(SocketAddr, TcpStream, &str)> {
180 : use postgres_client::config::Host;
181 :
182 : // wrap TcpStream::connect with timeout
183 0 : let connect_with_timeout = |host, port| {
184 0 : tokio::time::timeout(timeout, TcpStream::connect((host, port))).map(
185 0 : move |res| match res {
186 0 : Ok(tcpstream_connect_res) => tcpstream_connect_res,
187 0 : Err(_) => Err(io::Error::new(
188 0 : io::ErrorKind::TimedOut,
189 0 : format!("exceeded connection timeout {timeout:?}"),
190 0 : )),
191 0 : },
192 0 : )
193 0 : };
194 :
195 0 : let connect_once = |host, port| {
196 0 : debug!("trying to connect to compute node at {host}:{port}");
197 0 : connect_with_timeout(host, port).and_then(|stream| async {
198 0 : let socket_addr = stream.peer_addr()?;
199 0 : let socket = socket2::SockRef::from(&stream);
200 0 : // Disable Nagle's algorithm to not introduce latency between
201 0 : // client and compute.
202 0 : socket.set_nodelay(true)?;
203 : // This prevents load balancer from severing the connection.
204 0 : socket.set_keepalive(true)?;
205 0 : Ok((socket_addr, stream))
206 0 : })
207 0 : };
208 :
209 : // We can't reuse connection establishing logic from `postgres_client` here,
210 : // because it has no means for extracting the underlying socket which we
211 : // require for our business.
212 0 : let port = self.0.get_port();
213 0 : let host = self.0.get_host();
214 0 :
215 0 : let host = match host {
216 0 : Host::Tcp(host) => host.as_str(),
217 0 : };
218 0 :
219 0 : match connect_once(host, port).await {
220 0 : Ok((sockaddr, stream)) => Ok((sockaddr, stream, host)),
221 0 : Err(err) => {
222 0 : warn!("couldn't connect to compute node at {host}:{port}: {err}");
223 0 : Err(err)
224 : }
225 : }
226 0 : }
227 : }
228 :
229 : type RustlsStream = <MakeRustlsConnect as MakeTlsConnect<tokio::net::TcpStream>>::Stream;
230 :
231 : pub(crate) struct PostgresConnection {
232 : /// Socket connected to a compute node.
233 : pub(crate) stream:
234 : postgres_client::maybe_tls_stream::MaybeTlsStream<tokio::net::TcpStream, RustlsStream>,
235 : /// PostgreSQL connection parameters.
236 : pub(crate) params: std::collections::HashMap<String, String>,
237 : /// Query cancellation token.
238 : pub(crate) cancel_closure: CancelClosure,
239 : /// Labels for proxy's metrics.
240 : pub(crate) aux: MetricsAuxInfo,
241 : /// Notices received from compute after authenticating
242 : pub(crate) delayed_notice: Vec<NoticeResponseBody>,
243 :
244 : _guage: NumDbConnectionsGuard<'static>,
245 : }
246 :
247 : impl ConnCfg {
248 : /// Connect to a corresponding compute node.
249 0 : pub(crate) async fn connect(
250 0 : &self,
251 0 : ctx: &RequestContext,
252 0 : aux: MetricsAuxInfo,
253 0 : config: &ComputeConfig,
254 0 : user_info: ComputeUserInfo,
255 0 : ) -> Result<PostgresConnection, ConnectionError> {
256 0 : let pause = ctx.latency_timer_pause(crate::metrics::Waiting::Compute);
257 0 : let (socket_addr, stream, host) = self.connect_raw(config.timeout).await?;
258 0 : drop(pause);
259 0 :
260 0 : let mut mk_tls = crate::tls::postgres_rustls::MakeRustlsConnect::new(config.tls.clone());
261 0 : let tls = <MakeRustlsConnect as MakeTlsConnect<tokio::net::TcpStream>>::make_tls_connect(
262 0 : &mut mk_tls,
263 0 : host,
264 0 : )?;
265 :
266 : // connect_raw() will not use TLS if sslmode is "disable"
267 0 : let pause = ctx.latency_timer_pause(crate::metrics::Waiting::Compute);
268 0 : let connection = self.0.connect_raw(stream, tls).await?;
269 0 : drop(pause);
270 0 :
271 0 : let RawConnection {
272 0 : stream,
273 0 : parameters,
274 0 : delayed_notice,
275 0 : process_id,
276 0 : secret_key,
277 0 : } = connection;
278 0 :
279 0 : tracing::Span::current().record("pid", tracing::field::display(process_id));
280 0 : let stream = stream.into_inner();
281 0 :
282 0 : // TODO: lots of useful info but maybe we can move it elsewhere (eg traces?)
283 0 : info!(
284 0 : cold_start_info = ctx.cold_start_info().as_str(),
285 0 : "connected to compute node at {host} ({socket_addr}) sslmode={:?}",
286 0 : self.0.get_ssl_mode()
287 : );
288 :
289 : // NB: CancelToken is supposed to hold socket_addr, but we use connect_raw.
290 : // Yet another reason to rework the connection establishing code.
291 0 : let cancel_closure = CancelClosure::new(
292 0 : socket_addr,
293 0 : CancelToken {
294 0 : socket_config: None,
295 0 : ssl_mode: self.0.get_ssl_mode(),
296 0 : process_id,
297 0 : secret_key,
298 0 : },
299 0 : host.to_string(),
300 0 : user_info,
301 0 : );
302 0 :
303 0 : let connection = PostgresConnection {
304 0 : stream,
305 0 : params: parameters,
306 0 : delayed_notice,
307 0 : cancel_closure,
308 0 : aux,
309 0 : _guage: Metrics::get().proxy.db_connections.guard(ctx.protocol()),
310 0 : };
311 0 :
312 0 : Ok(connection)
313 0 : }
314 : }
315 :
316 : /// Retrieve `options` from a startup message, dropping all proxy-secific flags.
317 6 : fn filtered_options(options: &str) -> Option<String> {
318 6 : #[allow(unstable_name_collisions)]
319 6 : let options: String = StartupMessageParams::parse_options_raw(options)
320 14 : .filter(|opt| parse_endpoint_param(opt).is_none() && neon_option(opt).is_none())
321 6 : .intersperse(" ") // TODO: use impl from std once it's stabilized
322 6 : .collect();
323 6 :
324 6 : // Don't even bother with empty options.
325 6 : if options.is_empty() {
326 3 : return None;
327 3 : }
328 3 :
329 3 : Some(options)
330 6 : }
331 :
332 : #[cfg(test)]
333 : mod tests {
334 : use super::*;
335 :
336 : #[test]
337 1 : fn test_filtered_options() {
338 1 : // Empty options is unlikely to be useful anyway.
339 1 : let params = "";
340 1 : assert_eq!(filtered_options(params), None);
341 :
342 : // It's likely that clients will only use options to specify endpoint/project.
343 1 : let params = "project=foo";
344 1 : assert_eq!(filtered_options(params), None);
345 :
346 : // Same, because unescaped whitespaces are no-op.
347 1 : let params = " project=foo ";
348 1 : assert_eq!(filtered_options(params).as_deref(), None);
349 :
350 1 : let params = r"\ project=foo \ ";
351 1 : assert_eq!(filtered_options(params).as_deref(), Some(r"\ \ "));
352 :
353 1 : let params = "project = foo";
354 1 : assert_eq!(filtered_options(params).as_deref(), Some("project = foo"));
355 :
356 1 : let params = "project = foo neon_endpoint_type:read_write neon_lsn:0/2 neon_proxy_params_compat:true";
357 1 : assert_eq!(filtered_options(params).as_deref(), Some("project = foo"));
358 1 : }
359 : }
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