Line data Source code
1 : //! Postgres protocol messages serialization-deserialization. See
2 : //! <https://www.postgresql.org/docs/devel/protocol-message-formats.html>
3 : //! on message formats.
4 : #![deny(clippy::undocumented_unsafe_blocks)]
5 :
6 : pub mod framed;
7 :
8 : use byteorder::{BigEndian, ReadBytesExt};
9 : use bytes::{Buf, BufMut, Bytes, BytesMut};
10 : use itertools::Itertools;
11 : use serde::{Deserialize, Serialize};
12 : use std::{borrow::Cow, fmt, io, str};
13 :
14 : // re-export for use in utils pageserver_feedback.rs
15 : pub use postgres_protocol::PG_EPOCH;
16 :
17 : pub type Oid = u32;
18 : pub type SystemId = u64;
19 :
20 : pub const INT8_OID: Oid = 20;
21 : pub const INT4_OID: Oid = 23;
22 : pub const TEXT_OID: Oid = 25;
23 :
24 : #[derive(Debug)]
25 : pub enum FeMessage {
26 : // Simple query.
27 : Query(Bytes),
28 : // Extended query protocol.
29 : Parse(FeParseMessage),
30 : Describe(FeDescribeMessage),
31 : Bind(FeBindMessage),
32 : Execute(FeExecuteMessage),
33 : Close(FeCloseMessage),
34 : Sync,
35 : Terminate,
36 : CopyData(Bytes),
37 : CopyDone,
38 : CopyFail,
39 : PasswordMessage(Bytes),
40 : }
41 :
42 : #[derive(Clone, Copy, PartialEq, PartialOrd)]
43 : pub struct ProtocolVersion(u32);
44 :
45 : impl ProtocolVersion {
46 0 : pub const fn new(major: u16, minor: u16) -> Self {
47 0 : Self((major as u32) << 16 | minor as u32)
48 0 : }
49 0 : pub const fn minor(self) -> u16 {
50 0 : self.0 as u16
51 0 : }
52 24 : pub const fn major(self) -> u16 {
53 24 : (self.0 >> 16) as u16
54 24 : }
55 : }
56 :
57 : impl fmt::Debug for ProtocolVersion {
58 0 : fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
59 0 : f.debug_list()
60 0 : .entry(&self.major())
61 0 : .entry(&self.minor())
62 0 : .finish()
63 0 : }
64 : }
65 :
66 : #[derive(Debug)]
67 : pub enum FeStartupPacket {
68 : CancelRequest(CancelKeyData),
69 : SslRequest {
70 : direct: bool,
71 : },
72 : GssEncRequest,
73 : StartupMessage {
74 : version: ProtocolVersion,
75 : params: StartupMessageParams,
76 : },
77 : }
78 :
79 : #[derive(Debug, Clone, Default)]
80 : pub struct StartupMessageParamsBuilder {
81 : params: BytesMut,
82 : }
83 :
84 : impl StartupMessageParamsBuilder {
85 : /// Set parameter's value by its name.
86 : /// name and value must not contain a \0 byte
87 31 : pub fn insert(&mut self, name: &str, value: &str) {
88 31 : self.params.put(name.as_bytes());
89 31 : self.params.put(&b"\0"[..]);
90 31 : self.params.put(value.as_bytes());
91 31 : self.params.put(&b"\0"[..]);
92 31 : }
93 :
94 23 : pub fn freeze(self) -> StartupMessageParams {
95 23 : StartupMessageParams {
96 23 : params: self.params.freeze(),
97 23 : }
98 23 : }
99 : }
100 :
101 : #[derive(Debug, Clone, Default)]
102 : pub struct StartupMessageParams {
103 : params: Bytes,
104 : }
105 :
106 : impl StartupMessageParams {
107 : /// Get parameter's value by its name.
108 48 : pub fn get(&self, name: &str) -> Option<&str> {
109 64 : self.iter().find_map(|(k, v)| (k == name).then_some(v))
110 48 : }
111 :
112 : /// Split command-line options according to PostgreSQL's logic,
113 : /// taking into account all escape sequences but leaving them as-is.
114 : /// [`None`] means that there's no `options` in [`Self`].
115 30 : pub fn options_raw(&self) -> Option<impl Iterator<Item = &str>> {
116 30 : self.get("options").map(Self::parse_options_raw)
117 30 : }
118 :
119 : /// Split command-line options according to PostgreSQL's logic,
120 : /// applying all escape sequences (using owned strings as needed).
121 : /// [`None`] means that there's no `options` in [`Self`].
122 5 : pub fn options_escaped(&self) -> Option<impl Iterator<Item = Cow<'_, str>>> {
123 5 : self.get("options").map(Self::parse_options_escaped)
124 5 : }
125 :
126 : /// Split command-line options according to PostgreSQL's logic,
127 : /// taking into account all escape sequences but leaving them as-is.
128 30 : pub fn parse_options_raw(input: &str) -> impl Iterator<Item = &str> {
129 30 : // See `postgres: pg_split_opts`.
130 30 : let mut last_was_escape = false;
131 30 : input
132 564 : .split(move |c: char| {
133 : // We split by non-escaped whitespace symbols.
134 564 : let should_split = c.is_ascii_whitespace() && !last_was_escape;
135 564 : last_was_escape = c == '\\' && !last_was_escape;
136 564 : should_split
137 564 : })
138 76 : .filter(|s| !s.is_empty())
139 30 : }
140 :
141 : /// Split command-line options according to PostgreSQL's logic,
142 : /// applying all escape sequences (using owned strings as needed).
143 4 : pub fn parse_options_escaped(input: &str) -> impl Iterator<Item = Cow<'_, str>> {
144 4 : // See `postgres: pg_split_opts`.
145 7 : Self::parse_options_raw(input).map(|s| {
146 7 : let mut preserve_next_escape = false;
147 17 : let escape = |c| {
148 : // We should remove '\\' unless it's preceded by '\\'.
149 17 : let should_remove = c == '\\' && !preserve_next_escape;
150 17 : preserve_next_escape = should_remove;
151 17 : should_remove
152 17 : };
153 :
154 7 : match s.contains('\\') {
155 3 : true => Cow::Owned(s.replace(escape, "")),
156 4 : false => Cow::Borrowed(s),
157 : }
158 7 : })
159 4 : }
160 :
161 : /// Iterate through key-value pairs in an arbitrary order.
162 55 : pub fn iter(&self) -> impl Iterator<Item = (&str, &str)> {
163 55 : let params =
164 55 : std::str::from_utf8(&self.params).expect("should be validated as utf8 already");
165 55 : params.split_terminator('\0').tuples()
166 55 : }
167 :
168 : // This function is mostly useful in tests.
169 : #[doc(hidden)]
170 23 : pub fn new<'a, const N: usize>(pairs: [(&'a str, &'a str); N]) -> Self {
171 23 : let mut b = StartupMessageParamsBuilder::default();
172 54 : for (k, v) in pairs {
173 31 : b.insert(k, v)
174 : }
175 23 : b.freeze()
176 23 : }
177 : }
178 :
179 6 : #[derive(Debug, Hash, PartialEq, Eq, Clone, Copy, Serialize, Deserialize)]
180 : pub struct CancelKeyData {
181 : pub backend_pid: i32,
182 : pub cancel_key: i32,
183 : }
184 :
185 : impl fmt::Display for CancelKeyData {
186 0 : fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
187 0 : let hi = (self.backend_pid as u64) << 32;
188 0 : let lo = self.cancel_key as u64;
189 0 : let id = hi | lo;
190 0 :
191 0 : // This format is more compact and might work better for logs.
192 0 : f.debug_tuple("CancelKeyData")
193 0 : .field(&format_args!("{:x}", id))
194 0 : .finish()
195 0 : }
196 : }
197 :
198 : use rand::distributions::{Distribution, Standard};
199 : impl Distribution<CancelKeyData> for Standard {
200 1 : fn sample<R: rand::Rng + ?Sized>(&self, rng: &mut R) -> CancelKeyData {
201 1 : CancelKeyData {
202 1 : backend_pid: rng.gen(),
203 1 : cancel_key: rng.gen(),
204 1 : }
205 1 : }
206 : }
207 :
208 : // We only support the simple case of Parse on unnamed prepared statement and
209 : // no params
210 : #[derive(Debug)]
211 : pub struct FeParseMessage {
212 : pub query_string: Bytes,
213 : }
214 :
215 : #[derive(Debug)]
216 : pub struct FeDescribeMessage {
217 : pub kind: u8, // 'S' to describe a prepared statement; or 'P' to describe a portal.
218 : // we only support unnamed prepared stmt or portal
219 : }
220 :
221 : // we only support unnamed prepared stmt and portal
222 : #[derive(Debug)]
223 : pub struct FeBindMessage;
224 :
225 : // we only support unnamed prepared stmt or portal
226 : #[derive(Debug)]
227 : pub struct FeExecuteMessage {
228 : /// max # of rows
229 : pub maxrows: i32,
230 : }
231 :
232 : // we only support unnamed prepared stmt and portal
233 : #[derive(Debug)]
234 : pub struct FeCloseMessage;
235 :
236 : /// An error occurred while parsing or serializing raw stream into Postgres
237 : /// messages.
238 0 : #[derive(thiserror::Error, Debug)]
239 : pub enum ProtocolError {
240 : /// Invalid packet was received from the client (e.g. unexpected message
241 : /// type or broken len).
242 : #[error("Protocol error: {0}")]
243 : Protocol(String),
244 : /// Failed to parse or, (unlikely), serialize a protocol message.
245 : #[error("Message parse error: {0}")]
246 : BadMessage(String),
247 : }
248 :
249 : impl ProtocolError {
250 : /// Proxy stream.rs uses only io::Error; provide it.
251 0 : pub fn into_io_error(self) -> io::Error {
252 0 : io::Error::new(io::ErrorKind::Other, self.to_string())
253 0 : }
254 : }
255 :
256 : impl FeMessage {
257 : /// Read and parse one message from the `buf` input buffer. If there is at
258 : /// least one valid message, returns it, advancing `buf`; redundant copies
259 : /// are avoided, as thanks to `bytes` crate ptrs in parsed message point
260 : /// directly into the `buf` (processed data is garbage collected after
261 : /// parsed message is dropped).
262 : ///
263 : /// Returns None if `buf` doesn't contain enough data for a single message.
264 : /// For efficiency, tries to reserve large enough space in `buf` for the
265 : /// next message in this case to save the repeated calls.
266 : ///
267 : /// Returns Error if message is malformed, the only possible ErrorKind is
268 : /// InvalidInput.
269 : //
270 : // Inspired by rust-postgres Message::parse.
271 57 : pub fn parse(buf: &mut BytesMut) -> Result<Option<FeMessage>, ProtocolError> {
272 57 : // Every message contains message type byte and 4 bytes len; can't do
273 57 : // much without them.
274 57 : if buf.len() < 5 {
275 30 : let to_read = 5 - buf.len();
276 30 : buf.reserve(to_read);
277 30 : return Ok(None);
278 27 : }
279 27 :
280 27 : // We shouldn't advance `buf` as probably full message is not there yet,
281 27 : // so can't directly use Bytes::get_u32 etc.
282 27 : let tag = buf[0];
283 27 : let len = (&buf[1..5]).read_u32::<BigEndian>().unwrap();
284 27 : if len < 4 {
285 0 : return Err(ProtocolError::Protocol(format!(
286 0 : "invalid message length {}",
287 0 : len
288 0 : )));
289 27 : }
290 27 :
291 27 : // length field includes itself, but not message type.
292 27 : let total_len = len as usize + 1;
293 27 : if buf.len() < total_len {
294 : // Don't have full message yet.
295 0 : let to_read = total_len - buf.len();
296 0 : buf.reserve(to_read);
297 0 : return Ok(None);
298 27 : }
299 27 :
300 27 : // got the message, advance buffer
301 27 : let mut msg = buf.split_to(total_len).freeze();
302 27 : msg.advance(5); // consume message type and len
303 27 :
304 27 : match tag {
305 2 : b'Q' => Ok(Some(FeMessage::Query(msg))),
306 0 : b'P' => Ok(Some(FeParseMessage::parse(msg)?)),
307 0 : b'D' => Ok(Some(FeDescribeMessage::parse(msg)?)),
308 0 : b'E' => Ok(Some(FeExecuteMessage::parse(msg)?)),
309 0 : b'B' => Ok(Some(FeBindMessage::parse(msg)?)),
310 0 : b'C' => Ok(Some(FeCloseMessage::parse(msg)?)),
311 0 : b'S' => Ok(Some(FeMessage::Sync)),
312 0 : b'X' => Ok(Some(FeMessage::Terminate)),
313 0 : b'd' => Ok(Some(FeMessage::CopyData(msg))),
314 0 : b'c' => Ok(Some(FeMessage::CopyDone)),
315 0 : b'f' => Ok(Some(FeMessage::CopyFail)),
316 25 : b'p' => Ok(Some(FeMessage::PasswordMessage(msg))),
317 0 : tag => Err(ProtocolError::Protocol(format!(
318 0 : "unknown message tag: {tag},'{msg:?}'"
319 0 : ))),
320 : }
321 57 : }
322 : }
323 :
324 : impl FeStartupPacket {
325 : /// Read and parse startup message from the `buf` input buffer. It is
326 : /// different from [`FeMessage::parse`] because startup messages don't have
327 : /// message type byte; otherwise, its comments apply.
328 91 : pub fn parse(buf: &mut BytesMut) -> Result<Option<FeStartupPacket>, ProtocolError> {
329 : /// <https://github.com/postgres/postgres/blob/ca481d3c9ab7bf69ff0c8d71ad3951d407f6a33c/src/include/libpq/pqcomm.h#L118>
330 : const MAX_STARTUP_PACKET_LENGTH: usize = 10000;
331 : const RESERVED_INVALID_MAJOR_VERSION: u16 = 1234;
332 : /// <https://github.com/postgres/postgres/blob/ca481d3c9ab7bf69ff0c8d71ad3951d407f6a33c/src/include/libpq/pqcomm.h#L132>
333 : const CANCEL_REQUEST_CODE: ProtocolVersion = ProtocolVersion::new(1234, 5678);
334 : /// <https://github.com/postgres/postgres/blob/ca481d3c9ab7bf69ff0c8d71ad3951d407f6a33c/src/include/libpq/pqcomm.h#L166>
335 : const NEGOTIATE_SSL_CODE: ProtocolVersion = ProtocolVersion::new(1234, 5679);
336 : /// <https://github.com/postgres/postgres/blob/ca481d3c9ab7bf69ff0c8d71ad3951d407f6a33c/src/include/libpq/pqcomm.h#L167>
337 : const NEGOTIATE_GSS_CODE: ProtocolVersion = ProtocolVersion::new(1234, 5680);
338 :
339 : // <https://github.com/postgres/postgres/blob/04bcf9e19a4261fe9c7df37c777592c2e10c32a7/src/backend/tcop/backend_startup.c#L378-L382>
340 : // First byte indicates standard SSL handshake message
341 : // (It can't be a Postgres startup length because in network byte order
342 : // that would be a startup packet hundreds of megabytes long)
343 91 : if buf.first() == Some(&0x16) {
344 0 : return Ok(Some(FeStartupPacket::SslRequest { direct: true }));
345 91 : }
346 91 :
347 91 : // need at least 4 bytes with packet len
348 91 : if buf.len() < 4 {
349 45 : let to_read = 4 - buf.len();
350 45 : buf.reserve(to_read);
351 45 : return Ok(None);
352 46 : }
353 46 :
354 46 : // We shouldn't advance `buf` as probably full message is not there yet,
355 46 : // so can't directly use Bytes::get_u32 etc.
356 46 : let len = (&buf[0..4]).read_u32::<BigEndian>().unwrap() as usize;
357 46 : // The proposed replacement is `!(8..=MAX_STARTUP_PACKET_LENGTH).contains(&len)`
358 46 : // which is less readable
359 46 : #[allow(clippy::manual_range_contains)]
360 46 : if len < 8 || len > MAX_STARTUP_PACKET_LENGTH {
361 1 : return Err(ProtocolError::Protocol(format!(
362 1 : "invalid startup packet message length {}",
363 1 : len
364 1 : )));
365 45 : }
366 45 :
367 45 : if buf.len() < len {
368 : // Don't have full message yet.
369 0 : let to_read = len - buf.len();
370 0 : buf.reserve(to_read);
371 0 : return Ok(None);
372 45 : }
373 45 :
374 45 : // got the message, advance buffer
375 45 : let mut msg = buf.split_to(len).freeze();
376 45 : msg.advance(4); // consume len
377 45 :
378 45 : let request_code = ProtocolVersion(msg.get_u32());
379 : // StartupMessage, CancelRequest, SSLRequest etc are differentiated by request code.
380 45 : let message = match request_code {
381 : CANCEL_REQUEST_CODE => {
382 0 : if msg.remaining() != 8 {
383 0 : return Err(ProtocolError::BadMessage(
384 0 : "CancelRequest message is malformed, backend PID / secret key missing"
385 0 : .to_owned(),
386 0 : ));
387 0 : }
388 0 : FeStartupPacket::CancelRequest(CancelKeyData {
389 0 : backend_pid: msg.get_i32(),
390 0 : cancel_key: msg.get_i32(),
391 0 : })
392 : }
393 : NEGOTIATE_SSL_CODE => {
394 : // Requested upgrade to SSL (aka TLS)
395 21 : FeStartupPacket::SslRequest { direct: false }
396 : }
397 : NEGOTIATE_GSS_CODE => {
398 : // Requested upgrade to GSSAPI
399 0 : FeStartupPacket::GssEncRequest
400 : }
401 24 : version if version.major() == RESERVED_INVALID_MAJOR_VERSION => {
402 0 : return Err(ProtocolError::Protocol(format!(
403 0 : "Unrecognized request code {}",
404 0 : version.minor()
405 0 : )));
406 : }
407 : // TODO bail if protocol major_version is not 3?
408 24 : version => {
409 : // StartupMessage
410 :
411 24 : let s = str::from_utf8(&msg).map_err(|_e| {
412 0 : ProtocolError::BadMessage("StartupMessage params: invalid utf-8".to_owned())
413 24 : })?;
414 24 : let s = s.strip_suffix('\0').ok_or_else(|| {
415 0 : ProtocolError::Protocol(
416 0 : "StartupMessage params: missing null terminator".to_string(),
417 0 : )
418 24 : })?;
419 :
420 24 : FeStartupPacket::StartupMessage {
421 24 : version,
422 24 : params: StartupMessageParams {
423 24 : params: msg.slice_ref(s.as_bytes()),
424 24 : },
425 24 : }
426 : }
427 : };
428 45 : Ok(Some(message))
429 91 : }
430 : }
431 :
432 : impl FeParseMessage {
433 0 : fn parse(mut buf: Bytes) -> Result<FeMessage, ProtocolError> {
434 : // FIXME: the rust-postgres driver uses a named prepared statement
435 : // for copy_out(). We're not prepared to handle that correctly. For
436 : // now, just ignore the statement name, assuming that the client never
437 : // uses more than one prepared statement at a time.
438 :
439 0 : let _pstmt_name = read_cstr(&mut buf)?;
440 0 : let query_string = read_cstr(&mut buf)?;
441 0 : if buf.remaining() < 2 {
442 0 : return Err(ProtocolError::BadMessage(
443 0 : "Parse message is malformed, nparams missing".to_string(),
444 0 : ));
445 0 : }
446 0 : let nparams = buf.get_i16();
447 0 :
448 0 : if nparams != 0 {
449 0 : return Err(ProtocolError::BadMessage(
450 0 : "query params not implemented".to_string(),
451 0 : ));
452 0 : }
453 0 :
454 0 : Ok(FeMessage::Parse(FeParseMessage { query_string }))
455 0 : }
456 : }
457 :
458 : impl FeDescribeMessage {
459 0 : fn parse(mut buf: Bytes) -> Result<FeMessage, ProtocolError> {
460 0 : let kind = buf.get_u8();
461 0 : let _pstmt_name = read_cstr(&mut buf)?;
462 :
463 : // FIXME: see FeParseMessage::parse
464 0 : if kind != b'S' {
465 0 : return Err(ProtocolError::BadMessage(
466 0 : "only prepared statemement Describe is implemented".to_string(),
467 0 : ));
468 0 : }
469 0 :
470 0 : Ok(FeMessage::Describe(FeDescribeMessage { kind }))
471 0 : }
472 : }
473 :
474 : impl FeExecuteMessage {
475 0 : fn parse(mut buf: Bytes) -> Result<FeMessage, ProtocolError> {
476 0 : let portal_name = read_cstr(&mut buf)?;
477 0 : if buf.remaining() < 4 {
478 0 : return Err(ProtocolError::BadMessage(
479 0 : "FeExecuteMessage message is malformed, maxrows missing".to_string(),
480 0 : ));
481 0 : }
482 0 : let maxrows = buf.get_i32();
483 0 :
484 0 : if !portal_name.is_empty() {
485 0 : return Err(ProtocolError::BadMessage(
486 0 : "named portals not implemented".to_string(),
487 0 : ));
488 0 : }
489 0 : if maxrows != 0 {
490 0 : return Err(ProtocolError::BadMessage(
491 0 : "row limit in Execute message not implemented".to_string(),
492 0 : ));
493 0 : }
494 0 :
495 0 : Ok(FeMessage::Execute(FeExecuteMessage { maxrows }))
496 0 : }
497 : }
498 :
499 : impl FeBindMessage {
500 0 : fn parse(mut buf: Bytes) -> Result<FeMessage, ProtocolError> {
501 0 : let portal_name = read_cstr(&mut buf)?;
502 0 : let _pstmt_name = read_cstr(&mut buf)?;
503 :
504 : // FIXME: see FeParseMessage::parse
505 0 : if !portal_name.is_empty() {
506 0 : return Err(ProtocolError::BadMessage(
507 0 : "named portals not implemented".to_string(),
508 0 : ));
509 0 : }
510 0 :
511 0 : Ok(FeMessage::Bind(FeBindMessage))
512 0 : }
513 : }
514 :
515 : impl FeCloseMessage {
516 0 : fn parse(mut buf: Bytes) -> Result<FeMessage, ProtocolError> {
517 0 : let _kind = buf.get_u8();
518 0 : let _pstmt_or_portal_name = read_cstr(&mut buf)?;
519 :
520 : // FIXME: we do nothing with Close
521 0 : Ok(FeMessage::Close(FeCloseMessage))
522 0 : }
523 : }
524 :
525 : // Backend
526 :
527 : #[derive(Debug)]
528 : pub enum BeMessage<'a> {
529 : AuthenticationOk,
530 : AuthenticationMD5Password([u8; 4]),
531 : AuthenticationSasl(BeAuthenticationSaslMessage<'a>),
532 : AuthenticationCleartextPassword,
533 : BackendKeyData(CancelKeyData),
534 : BindComplete,
535 : CommandComplete(&'a [u8]),
536 : CopyData(&'a [u8]),
537 : CopyDone,
538 : CopyFail,
539 : CopyInResponse,
540 : CopyOutResponse,
541 : CopyBothResponse,
542 : CloseComplete,
543 : // None means column is NULL
544 : DataRow(&'a [Option<&'a [u8]>]),
545 : // None errcode means internal_error will be sent.
546 : ErrorResponse(&'a str, Option<&'a [u8; 5]>),
547 : /// Single byte - used in response to SSLRequest/GSSENCRequest.
548 : EncryptionResponse(bool),
549 : NoData,
550 : ParameterDescription,
551 : ParameterStatus {
552 : name: &'a [u8],
553 : value: &'a [u8],
554 : },
555 : ParseComplete,
556 : ReadyForQuery,
557 : RowDescription(&'a [RowDescriptor<'a>]),
558 : XLogData(XLogDataBody<'a>),
559 : NoticeResponse(&'a str),
560 : NegotiateProtocolVersion {
561 : version: ProtocolVersion,
562 : options: &'a [&'a str],
563 : },
564 : KeepAlive(WalSndKeepAlive),
565 : }
566 :
567 : /// Common shorthands.
568 : impl<'a> BeMessage<'a> {
569 : /// A [`BeMessage::ParameterStatus`] holding the client encoding, i.e. UTF-8.
570 : /// This is a sensible default, given that:
571 : /// * rust strings only support this encoding out of the box.
572 : /// * tokio-postgres, postgres-jdbc (and probably more) mandate it.
573 : ///
574 : /// TODO: do we need to report `server_encoding` as well?
575 : pub const CLIENT_ENCODING: Self = Self::ParameterStatus {
576 : name: b"client_encoding",
577 : value: b"UTF8",
578 : };
579 :
580 : pub const INTEGER_DATETIMES: Self = Self::ParameterStatus {
581 : name: b"integer_datetimes",
582 : value: b"on",
583 : };
584 :
585 : /// Build a [`BeMessage::ParameterStatus`] holding the server version.
586 2 : pub fn server_version(version: &'a str) -> Self {
587 2 : Self::ParameterStatus {
588 2 : name: b"server_version",
589 2 : value: version.as_bytes(),
590 2 : }
591 2 : }
592 : }
593 :
594 : #[derive(Debug)]
595 : pub enum BeAuthenticationSaslMessage<'a> {
596 : Methods(&'a [&'a str]),
597 : Continue(&'a [u8]),
598 : Final(&'a [u8]),
599 : }
600 :
601 : #[derive(Debug)]
602 : pub enum BeParameterStatusMessage<'a> {
603 : Encoding(&'a str),
604 : ServerVersion(&'a str),
605 : }
606 :
607 : // One row description in RowDescription packet.
608 : #[derive(Debug)]
609 : pub struct RowDescriptor<'a> {
610 : pub name: &'a [u8],
611 : pub tableoid: Oid,
612 : pub attnum: i16,
613 : pub typoid: Oid,
614 : pub typlen: i16,
615 : pub typmod: i32,
616 : pub formatcode: i16,
617 : }
618 :
619 : impl Default for RowDescriptor<'_> {
620 0 : fn default() -> RowDescriptor<'static> {
621 0 : RowDescriptor {
622 0 : name: b"",
623 0 : tableoid: 0,
624 0 : attnum: 0,
625 0 : typoid: 0,
626 0 : typlen: 0,
627 0 : typmod: 0,
628 0 : formatcode: 0,
629 0 : }
630 0 : }
631 : }
632 :
633 : impl RowDescriptor<'_> {
634 : /// Convenience function to create a RowDescriptor message for an int8 column
635 0 : pub const fn int8_col(name: &[u8]) -> RowDescriptor {
636 0 : RowDescriptor {
637 0 : name,
638 0 : tableoid: 0,
639 0 : attnum: 0,
640 0 : typoid: INT8_OID,
641 0 : typlen: 8,
642 0 : typmod: 0,
643 0 : formatcode: 0,
644 0 : }
645 0 : }
646 :
647 2 : pub const fn text_col(name: &[u8]) -> RowDescriptor {
648 2 : RowDescriptor {
649 2 : name,
650 2 : tableoid: 0,
651 2 : attnum: 0,
652 2 : typoid: TEXT_OID,
653 2 : typlen: -1,
654 2 : typmod: 0,
655 2 : formatcode: 0,
656 2 : }
657 2 : }
658 : }
659 :
660 : #[derive(Debug)]
661 : pub struct XLogDataBody<'a> {
662 : pub wal_start: u64,
663 : pub wal_end: u64, // current end of WAL on the server
664 : pub timestamp: i64,
665 : pub data: &'a [u8],
666 : }
667 :
668 : #[derive(Debug)]
669 : pub struct WalSndKeepAlive {
670 : pub wal_end: u64, // current end of WAL on the server
671 : pub timestamp: i64,
672 : pub request_reply: bool,
673 : }
674 :
675 : pub static HELLO_WORLD_ROW: BeMessage = BeMessage::DataRow(&[Some(b"hello world")]);
676 :
677 : // single text column
678 : pub static SINGLE_COL_ROWDESC: BeMessage = BeMessage::RowDescription(&[RowDescriptor {
679 : name: b"data",
680 : tableoid: 0,
681 : attnum: 0,
682 : typoid: TEXT_OID,
683 : typlen: -1,
684 : typmod: 0,
685 : formatcode: 0,
686 : }]);
687 :
688 : /// Call f() to write body of the message and prepend it with 4-byte len as
689 : /// prescribed by the protocol.
690 75 : fn write_body<R>(buf: &mut BytesMut, f: impl FnOnce(&mut BytesMut) -> R) -> R {
691 75 : let base = buf.len();
692 75 : buf.extend_from_slice(&[0; 4]);
693 75 :
694 75 : let res = f(buf);
695 75 :
696 75 : let size = i32::try_from(buf.len() - base).expect("message too big to transmit");
697 75 : (&mut buf[base..]).put_slice(&size.to_be_bytes());
698 75 :
699 75 : res
700 75 : }
701 :
702 : /// Safe write of s into buf as cstring (String in the protocol).
703 56 : fn write_cstr(s: impl AsRef<[u8]>, buf: &mut BytesMut) -> Result<(), ProtocolError> {
704 56 : let bytes = s.as_ref();
705 56 : if bytes.contains(&0) {
706 0 : return Err(ProtocolError::BadMessage(
707 0 : "string contains embedded null".to_owned(),
708 0 : ));
709 56 : }
710 56 : buf.put_slice(bytes);
711 56 : buf.put_u8(0);
712 56 : Ok(())
713 56 : }
714 :
715 : /// Read cstring from buf, advancing it.
716 11 : pub fn read_cstr(buf: &mut Bytes) -> Result<Bytes, ProtocolError> {
717 11 : let pos = buf
718 11 : .iter()
719 156 : .position(|x| *x == 0)
720 11 : .ok_or_else(|| ProtocolError::BadMessage("missing cstring terminator".to_owned()))?;
721 11 : let result = buf.split_to(pos);
722 11 : buf.advance(1); // drop the null terminator
723 11 : Ok(result)
724 11 : }
725 :
726 : pub const SQLSTATE_INTERNAL_ERROR: &[u8; 5] = b"XX000";
727 : pub const SQLSTATE_ADMIN_SHUTDOWN: &[u8; 5] = b"57P01";
728 : pub const SQLSTATE_SUCCESSFUL_COMPLETION: &[u8; 5] = b"00000";
729 :
730 : impl BeMessage<'_> {
731 : /// Serialize `message` to the given `buf`.
732 : /// Apart from smart memory managemet, BytesMut is good here as msg len
733 : /// precedes its body and it is handy to write it down first and then fill
734 : /// the length. With Write we would have to either calc it manually or have
735 : /// one more buffer.
736 96 : pub fn write(buf: &mut BytesMut, message: &BeMessage) -> Result<(), ProtocolError> {
737 96 : match message {
738 12 : BeMessage::AuthenticationOk => {
739 12 : buf.put_u8(b'R');
740 12 : write_body(buf, |buf| {
741 12 : buf.put_i32(0); // Specifies that the authentication was successful.
742 12 : });
743 12 : }
744 :
745 2 : BeMessage::AuthenticationCleartextPassword => {
746 2 : buf.put_u8(b'R');
747 2 : write_body(buf, |buf| {
748 2 : buf.put_i32(3); // Specifies that clear text password is required.
749 2 : });
750 2 : }
751 :
752 0 : BeMessage::AuthenticationMD5Password(salt) => {
753 0 : buf.put_u8(b'R');
754 0 : write_body(buf, |buf| {
755 0 : buf.put_i32(5); // Specifies that an MD5-encrypted password is required.
756 0 : buf.put_slice(&salt[..]);
757 0 : });
758 0 : }
759 :
760 30 : BeMessage::AuthenticationSasl(msg) => {
761 30 : buf.put_u8(b'R');
762 30 : write_body(buf, |buf| {
763 : use BeAuthenticationSaslMessage::*;
764 30 : match msg {
765 13 : Methods(methods) => {
766 13 : buf.put_i32(10); // Specifies that SASL auth method is used.
767 25 : for method in methods.iter() {
768 25 : write_cstr(method, buf)?;
769 : }
770 13 : buf.put_u8(0); // zero terminator for the list
771 : }
772 11 : Continue(extra) => {
773 11 : buf.put_i32(11); // Continue SASL auth.
774 11 : buf.put_slice(extra);
775 11 : }
776 6 : Final(extra) => {
777 6 : buf.put_i32(12); // Send final SASL message.
778 6 : buf.put_slice(extra);
779 6 : }
780 : }
781 30 : Ok(())
782 30 : })?;
783 : }
784 :
785 0 : BeMessage::BackendKeyData(key_data) => {
786 0 : buf.put_u8(b'K');
787 0 : write_body(buf, |buf| {
788 0 : buf.put_i32(key_data.backend_pid);
789 0 : buf.put_i32(key_data.cancel_key);
790 0 : });
791 0 : }
792 :
793 0 : BeMessage::BindComplete => {
794 0 : buf.put_u8(b'2');
795 0 : write_body(buf, |_| {});
796 0 : }
797 :
798 0 : BeMessage::CloseComplete => {
799 0 : buf.put_u8(b'3');
800 0 : write_body(buf, |_| {});
801 0 : }
802 :
803 2 : BeMessage::CommandComplete(cmd) => {
804 2 : buf.put_u8(b'C');
805 2 : write_body(buf, |buf| write_cstr(cmd, buf))?;
806 : }
807 :
808 0 : BeMessage::CopyData(data) => {
809 0 : buf.put_u8(b'd');
810 0 : write_body(buf, |buf| {
811 0 : buf.put_slice(data);
812 0 : });
813 0 : }
814 :
815 0 : BeMessage::CopyDone => {
816 0 : buf.put_u8(b'c');
817 0 : write_body(buf, |_| {});
818 0 : }
819 :
820 0 : BeMessage::CopyFail => {
821 0 : buf.put_u8(b'f');
822 0 : write_body(buf, |_| {});
823 0 : }
824 :
825 0 : BeMessage::CopyInResponse => {
826 0 : buf.put_u8(b'G');
827 0 : write_body(buf, |buf| {
828 0 : buf.put_u8(1); // copy_is_binary
829 0 : buf.put_i16(0); // numAttributes
830 0 : });
831 0 : }
832 :
833 0 : BeMessage::CopyOutResponse => {
834 0 : buf.put_u8(b'H');
835 0 : write_body(buf, |buf| {
836 0 : buf.put_u8(0); // copy_is_binary
837 0 : buf.put_i16(0); // numAttributes
838 0 : });
839 0 : }
840 :
841 0 : BeMessage::CopyBothResponse => {
842 0 : buf.put_u8(b'W');
843 0 : write_body(buf, |buf| {
844 0 : // doesn't matter, used only for replication
845 0 : buf.put_u8(0); // copy_is_binary
846 0 : buf.put_i16(0); // numAttributes
847 0 : });
848 0 : }
849 :
850 2 : BeMessage::DataRow(vals) => {
851 2 : buf.put_u8(b'D');
852 2 : write_body(buf, |buf| {
853 2 : buf.put_u16(vals.len() as u16); // num of cols
854 2 : for val_opt in vals.iter() {
855 2 : if let Some(val) = val_opt {
856 2 : buf.put_u32(val.len() as u32);
857 2 : buf.put_slice(val);
858 2 : } else {
859 0 : buf.put_i32(-1);
860 0 : }
861 : }
862 2 : });
863 2 : }
864 :
865 : // ErrorResponse is a zero-terminated array of zero-terminated fields.
866 : // First byte of each field represents type of this field. Set just enough fields
867 : // to satisfy rust-postgres client: 'S' -- severity, 'C' -- error, 'M' -- error
868 : // message text.
869 1 : BeMessage::ErrorResponse(error_msg, pg_error_code) => {
870 1 : // 'E' signalizes ErrorResponse messages
871 1 : buf.put_u8(b'E');
872 1 : write_body(buf, |buf| {
873 1 : buf.put_u8(b'S'); // severity
874 1 : buf.put_slice(b"ERROR\0");
875 1 :
876 1 : buf.put_u8(b'C'); // SQLSTATE error code
877 1 : buf.put_slice(&terminate_code(
878 1 : pg_error_code.unwrap_or(SQLSTATE_INTERNAL_ERROR),
879 1 : ));
880 1 :
881 1 : buf.put_u8(b'M'); // the message
882 1 : write_cstr(error_msg, buf)?;
883 :
884 1 : buf.put_u8(0); // terminator
885 1 : Ok(())
886 1 : })?;
887 : }
888 :
889 : // NoticeResponse has the same format as ErrorResponse. From doc: "The frontend should display the
890 : // message but continue listening for ReadyForQuery or ErrorResponse"
891 0 : BeMessage::NoticeResponse(error_msg) => {
892 0 : // For all the errors set Severity to Error and error code to
893 0 : // 'internal error'.
894 0 :
895 0 : // 'N' signalizes NoticeResponse messages
896 0 : buf.put_u8(b'N');
897 0 : write_body(buf, |buf| {
898 0 : buf.put_u8(b'S'); // severity
899 0 : buf.put_slice(b"NOTICE\0");
900 0 :
901 0 : buf.put_u8(b'C'); // SQLSTATE error code
902 0 : buf.put_slice(&terminate_code(SQLSTATE_INTERNAL_ERROR));
903 0 :
904 0 : buf.put_u8(b'M'); // the message
905 0 : write_cstr(error_msg.as_bytes(), buf)?;
906 :
907 0 : buf.put_u8(0); // terminator
908 0 : Ok(())
909 0 : })?;
910 : }
911 :
912 0 : BeMessage::NoData => {
913 0 : buf.put_u8(b'n');
914 0 : write_body(buf, |_| {});
915 0 : }
916 :
917 21 : BeMessage::EncryptionResponse(should_negotiate) => {
918 21 : let response = if *should_negotiate { b'S' } else { b'N' };
919 21 : buf.put_u8(response);
920 : }
921 :
922 13 : BeMessage::ParameterStatus { name, value } => {
923 13 : buf.put_u8(b'S');
924 13 : write_body(buf, |buf| {
925 13 : write_cstr(name, buf)?;
926 13 : write_cstr(value, buf)
927 13 : })?;
928 : }
929 :
930 0 : BeMessage::ParameterDescription => {
931 0 : buf.put_u8(b't');
932 0 : write_body(buf, |buf| {
933 0 : // we don't support params, so always 0
934 0 : buf.put_i16(0);
935 0 : });
936 0 : }
937 :
938 0 : BeMessage::ParseComplete => {
939 0 : buf.put_u8(b'1');
940 0 : write_body(buf, |_| {});
941 0 : }
942 :
943 11 : BeMessage::ReadyForQuery => {
944 11 : buf.put_u8(b'Z');
945 11 : write_body(buf, |buf| {
946 11 : buf.put_u8(b'I');
947 11 : });
948 11 : }
949 :
950 2 : BeMessage::RowDescription(rows) => {
951 2 : buf.put_u8(b'T');
952 2 : write_body(buf, |buf| {
953 2 : buf.put_i16(rows.len() as i16); // # of fields
954 2 : for row in rows.iter() {
955 2 : write_cstr(row.name, buf)?;
956 2 : buf.put_i32(0); /* table oid */
957 2 : buf.put_i16(0); /* attnum */
958 2 : buf.put_u32(row.typoid);
959 2 : buf.put_i16(row.typlen);
960 2 : buf.put_i32(-1); /* typmod */
961 2 : buf.put_i16(0); /* format code */
962 : }
963 2 : Ok(())
964 2 : })?;
965 : }
966 :
967 0 : BeMessage::XLogData(body) => {
968 0 : buf.put_u8(b'd');
969 0 : write_body(buf, |buf| {
970 0 : buf.put_u8(b'w');
971 0 : buf.put_u64(body.wal_start);
972 0 : buf.put_u64(body.wal_end);
973 0 : buf.put_i64(body.timestamp);
974 0 : buf.put_slice(body.data);
975 0 : });
976 0 : }
977 :
978 0 : BeMessage::KeepAlive(req) => {
979 0 : buf.put_u8(b'd');
980 0 : write_body(buf, |buf| {
981 0 : buf.put_u8(b'k');
982 0 : buf.put_u64(req.wal_end);
983 0 : buf.put_i64(req.timestamp);
984 0 : buf.put_u8(u8::from(req.request_reply));
985 0 : });
986 0 : }
987 :
988 0 : BeMessage::NegotiateProtocolVersion { version, options } => {
989 0 : buf.put_u8(b'v');
990 0 : write_body(buf, |buf| {
991 0 : buf.put_u32(version.0);
992 0 : buf.put_u32(options.len() as u32);
993 0 : for option in options.iter() {
994 0 : write_cstr(option, buf)?;
995 : }
996 0 : Ok(())
997 0 : })?
998 : }
999 : }
1000 96 : Ok(())
1001 96 : }
1002 : }
1003 :
1004 1 : fn terminate_code(code: &[u8; 5]) -> [u8; 6] {
1005 1 : let mut terminated = [0; 6];
1006 5 : for (i, &elem) in code.iter().enumerate() {
1007 5 : terminated[i] = elem;
1008 5 : }
1009 :
1010 1 : terminated
1011 1 : }
1012 :
1013 : #[cfg(test)]
1014 : mod tests {
1015 : use super::*;
1016 :
1017 : #[test]
1018 1 : fn test_startup_message_params_options_escaped() {
1019 4 : fn split_options(params: &StartupMessageParams) -> Vec<Cow<'_, str>> {
1020 4 : params
1021 4 : .options_escaped()
1022 4 : .expect("options are None")
1023 4 : .collect()
1024 4 : }
1025 :
1026 4 : let make_params = |options| StartupMessageParams::new([("options", options)]);
1027 :
1028 1 : let params = StartupMessageParams::new([]);
1029 1 : assert!(params.options_escaped().is_none());
1030 :
1031 1 : let params = make_params("");
1032 1 : assert!(split_options(¶ms).is_empty());
1033 :
1034 1 : let params = make_params("foo");
1035 1 : assert_eq!(split_options(¶ms), ["foo"]);
1036 :
1037 1 : let params = make_params(" foo bar ");
1038 1 : assert_eq!(split_options(¶ms), ["foo", "bar"]);
1039 :
1040 1 : let params = make_params("foo\\ bar \\ \\\\ baz\\ lol");
1041 1 : assert_eq!(split_options(¶ms), ["foo bar", " \\", "baz ", "lol"]);
1042 1 : }
1043 :
1044 : #[test]
1045 1 : fn parse_fe_startup_packet_regression() {
1046 1 : let data = [0, 0, 0, 7, 0, 0, 0, 0];
1047 1 : FeStartupPacket::parse(&mut BytesMut::from_iter(data)).unwrap_err();
1048 1 : }
1049 : }
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