pgwire/pg_message.rs
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// Copyright 2024 RisingWave Labs
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use std::collections::HashMap;
use std::ffi::CStr;
use std::io::{Error, ErrorKind, IoSlice, Result, Write};
use anyhow::anyhow;
use byteorder::{BigEndian, ByteOrder, NetworkEndian};
/// Part of code learned from <https://github.com/zenithdb/zenith/blob/main/zenith_utils/src/pq_proto.rs>.
use bytes::{Buf, BufMut, Bytes, BytesMut};
use tokio::io::{AsyncRead, AsyncReadExt};
use crate::error_or_notice::ErrorOrNoticeMessage;
use crate::pg_field_descriptor::PgFieldDescriptor;
use crate::pg_response::StatementType;
use crate::pg_server::BoxedError;
use crate::types::Row;
/// Messages that can be sent from pg client to server. Implement `read`.
#[derive(Debug)]
pub enum FeMessage {
Ssl,
Gss,
Startup(FeStartupMessage),
Query(FeQueryMessage),
Parse(FeParseMessage),
Password(FePasswordMessage),
Describe(FeDescribeMessage),
Bind(FeBindMessage),
Execute(FeExecuteMessage),
Close(FeCloseMessage),
Sync,
CancelQuery(FeCancelMessage),
Terminate,
Flush,
// special msg to detect health check, which represents the client immediately closes the connection cleanly without sending any data.
HealthCheck,
}
#[derive(Debug)]
pub struct FeStartupMessage {
pub config: HashMap<String, String>,
}
impl FeStartupMessage {
pub fn build_with_payload(payload: &[u8]) -> Result<Self> {
let config = match std::str::from_utf8(payload) {
Ok(v) => Ok(v.trim_end_matches('\0')),
Err(err) => Err(Error::new(
ErrorKind::InvalidInput,
anyhow!(err).context("Input end error"),
)),
}?;
let mut map = HashMap::new();
let config: Vec<&str> = config.split('\0').collect();
if config.len() % 2 == 1 {
return Err(Error::new(
ErrorKind::InvalidInput,
"Invalid input config: odd number of config pairs",
));
}
config.chunks(2).for_each(|chunk| {
map.insert(chunk[0].to_string(), chunk[1].to_string());
});
Ok(FeStartupMessage { config: map })
}
}
/// Query message contains the string sql.
#[derive(Debug)]
pub struct FeQueryMessage {
pub sql_bytes: Bytes,
}
#[derive(Debug)]
pub struct FeBindMessage {
pub param_format_codes: Vec<i16>,
pub result_format_codes: Vec<i16>,
pub params: Vec<Option<Bytes>>,
pub portal_name: Bytes,
pub statement_name: Bytes,
}
#[derive(Debug)]
pub struct FeExecuteMessage {
pub portal_name: Bytes,
pub max_rows: i32,
}
#[derive(Debug)]
pub struct FeParseMessage {
pub statement_name: Bytes,
pub sql_bytes: Bytes,
pub type_ids: Vec<i32>,
}
#[derive(Debug)]
pub struct FePasswordMessage {
pub password: Bytes,
}
#[derive(Debug)]
pub struct FeDescribeMessage {
// 'S' to describe a prepared statement; or 'P' to describe a portal.
pub kind: u8,
pub name: Bytes,
}
#[derive(Debug)]
pub struct FeCloseMessage {
pub kind: u8,
pub name: Bytes,
}
#[derive(Debug)]
pub struct FeCancelMessage {
pub target_process_id: i32,
pub target_secret_key: i32,
}
impl FeCancelMessage {
pub fn parse(mut buf: Bytes) -> Result<FeMessage> {
let target_process_id = buf.get_i32();
let target_secret_key = buf.get_i32();
Ok(FeMessage::CancelQuery(Self {
target_process_id,
target_secret_key,
}))
}
}
impl FeDescribeMessage {
pub fn parse(mut buf: Bytes) -> Result<FeMessage> {
let kind = buf.get_u8();
let name = read_null_terminated(&mut buf)?;
Ok(FeMessage::Describe(FeDescribeMessage { kind, name }))
}
}
impl FeBindMessage {
// Bind Message Header
// +-----+-----------+
// | 'B' | int32 len |
// +-----+-----------+
// Bind Message Body
// +----------------+---------------+
// | str portalname | str statement |
// +----------------+---------------+
// +---------------------+------------------+-------+
// | int16 numFormatCode | int16 FormatCode | ... |
// +---------------------+------------------+-------+
// +-----------------+-------------------+---------------+
// | int16 numParams | int32 valueLength | byte value.. |
// +-----------------+-------------------+---------------+
// +----------------------------------+------------------+-------+
// | int16 numResultColumnFormatCodes | int16 FormatCode | ... |
// +----------------------------------+------------------+-------+
pub fn parse(mut buf: Bytes) -> Result<FeMessage> {
let portal_name = read_null_terminated(&mut buf)?;
let statement_name = read_null_terminated(&mut buf)?;
let len = buf.get_i16();
let param_format_codes = (0..len).map(|_| buf.get_i16()).collect();
// Read Params
let len = buf.get_i16();
let params = (0..len)
.map(|_| {
let val_len = buf.get_i32();
if val_len == -1 {
None
} else {
Some(buf.copy_to_bytes(val_len as usize))
}
})
.collect();
let len = buf.get_i16();
let result_format_codes = (0..len).map(|_| buf.get_i16()).collect();
Ok(FeMessage::Bind(FeBindMessage {
param_format_codes,
result_format_codes,
params,
portal_name,
statement_name,
}))
}
}
impl FeExecuteMessage {
pub fn parse(mut buf: Bytes) -> Result<FeMessage> {
let portal_name = read_null_terminated(&mut buf)?;
let max_rows = buf.get_i32();
Ok(FeMessage::Execute(FeExecuteMessage {
portal_name,
max_rows,
}))
}
}
impl FeParseMessage {
pub fn parse(mut buf: Bytes) -> Result<FeMessage> {
let statement_name = read_null_terminated(&mut buf)?;
let sql_bytes = read_null_terminated(&mut buf)?;
let nparams = buf.get_i16();
let type_ids: Vec<i32> = (0..nparams).map(|_| buf.get_i32()).collect();
Ok(FeMessage::Parse(FeParseMessage {
statement_name,
sql_bytes,
type_ids,
}))
}
}
impl FePasswordMessage {
pub fn parse(mut buf: Bytes) -> Result<FeMessage> {
let password = read_null_terminated(&mut buf)?;
Ok(FeMessage::Password(FePasswordMessage { password }))
}
}
impl FeQueryMessage {
pub fn get_sql(&self) -> Result<&str> {
match CStr::from_bytes_with_nul(&self.sql_bytes) {
Ok(cstr) => cstr.to_str().map_err(|err| {
Error::new(
ErrorKind::InvalidInput,
anyhow!(err).context("Invalid UTF-8 sequence"),
)
}),
Err(err) => Err(Error::new(
ErrorKind::InvalidInput,
anyhow!(err).context("Input end error"),
)),
}
}
}
impl FeCloseMessage {
pub fn parse(mut buf: Bytes) -> Result<FeMessage> {
let kind = buf.get_u8();
let name = read_null_terminated(&mut buf)?;
Ok(FeMessage::Close(FeCloseMessage { kind, name }))
}
}
impl FeMessage {
/// Read one message from the stream.
pub async fn read(stream: &mut (impl AsyncRead + Unpin)) -> Result<FeMessage> {
let val = stream.read_u8().await?;
let len = stream.read_i32().await?;
let payload_len = len - 4;
let mut payload: Vec<u8> = vec![0; payload_len as usize];
if payload_len > 0 {
stream.read_exact(&mut payload).await?;
}
let sql_bytes = Bytes::from(payload);
match val {
b'Q' => Ok(FeMessage::Query(FeQueryMessage { sql_bytes })),
b'P' => FeParseMessage::parse(sql_bytes),
b'D' => FeDescribeMessage::parse(sql_bytes),
b'B' => FeBindMessage::parse(sql_bytes),
b'E' => FeExecuteMessage::parse(sql_bytes),
b'S' => Ok(FeMessage::Sync),
b'X' => Ok(FeMessage::Terminate),
b'C' => FeCloseMessage::parse(sql_bytes),
b'p' => FePasswordMessage::parse(sql_bytes),
b'H' => Ok(FeMessage::Flush),
_ => Err(std::io::Error::new(
ErrorKind::InvalidInput,
format!("Unsupported tag of regular message: {}", val),
)),
}
}
}
impl FeStartupMessage {
/// Read startup message from the stream.
pub async fn read(stream: &mut (impl AsyncRead + Unpin)) -> Result<FeMessage> {
let mut buffer1 = vec![0; 1];
let result = stream.read_exact(&mut buffer1).await;
let filled1 = match result {
Ok(n) => n,
Err(err) => {
// Detect whether it is a health check.
if err.kind() == ErrorKind::UnexpectedEof {
return Ok(FeMessage::HealthCheck);
} else {
return Err(err);
}
}
};
assert_eq!(filled1, 1);
let mut buffer2 = vec![0; 3];
let filled2 = stream.read_exact(&mut buffer2).await?;
assert_eq!(filled2, 3);
let mut buffer3 = BytesMut::with_capacity(4);
buffer3.put_slice(&buffer1);
buffer3.put_slice(&buffer2);
let len = NetworkEndian::read_i32(&buffer3);
let protocol_num = stream.read_i32().await?;
let payload_len = (len - 8) as usize;
if payload_len >= isize::MAX as usize {
return Err(std::io::Error::new(
ErrorKind::InvalidInput,
format!("Payload length has exceed usize::MAX {:?}", payload_len),
));
}
let mut payload = vec![0; payload_len];
if payload_len > 0 {
stream.read_exact(&mut payload).await?;
}
match protocol_num {
// code from: https://www.postgresql.org/docs/current/protocol-message-formats.html
196608 => Ok(FeMessage::Startup(FeStartupMessage::build_with_payload(
&payload,
)?)),
80877104 => Ok(FeMessage::Gss),
80877103 => Ok(FeMessage::Ssl),
// Cancel request code.
80877102 => FeCancelMessage::parse(Bytes::from(payload)),
_ => Err(std::io::Error::new(
ErrorKind::InvalidInput,
format!(
"Unsupported protocol number in start up msg {:?}",
protocol_num
),
)),
}
}
}
/// Continue read until reached a \0. Used in reading string from Bytes.
fn read_null_terminated(buf: &mut Bytes) -> Result<Bytes> {
let mut result = BytesMut::new();
loop {
if !buf.has_remaining() {
panic!("no null-terminator in string");
}
let byte = buf.get_u8();
if byte == 0 {
break;
}
result.put_u8(byte);
}
Ok(result.freeze())
}
/// Message sent from server to psql client. Implement `write` (how to serialize it into psql
/// buffer).
/// Ref: <https://www.postgresql.org/docs/current/protocol-message-formats.html>
#[derive(Debug)]
pub enum BeMessage<'a> {
AuthenticationOk,
AuthenticationCleartextPassword,
AuthenticationMd5Password(&'a [u8; 4]),
CommandComplete(BeCommandCompleteMessage),
NoticeResponse(&'a str),
// Single byte - used in response to SSLRequest/GSSENCRequest.
EncryptionResponseSsl,
EncryptionResponseGss,
EncryptionResponseNo,
EmptyQueryResponse,
ParseComplete,
BindComplete,
PortalSuspended,
// array of parameter oid(i32)
ParameterDescription(&'a [i32]),
NoData,
DataRow(&'a Row),
ParameterStatus(BeParameterStatusMessage<'a>),
ReadyForQuery(TransactionStatus),
RowDescription(&'a [PgFieldDescriptor]),
ErrorResponse(BoxedError),
CloseComplete,
// 0: process ID, 1: secret key
BackendKeyData((i32, i32)),
}
#[derive(Debug)]
pub enum BeParameterStatusMessage<'a> {
ClientEncoding(&'a str),
StandardConformingString(&'a str),
ServerVersion(&'a str),
ApplicationName(&'a str),
}
#[derive(Debug)]
pub struct BeCommandCompleteMessage {
pub stmt_type: StatementType,
pub rows_cnt: i32,
}
#[derive(Debug, Clone, Copy)]
pub enum TransactionStatus {
Idle,
InTransaction,
InFailedTransaction,
}
impl BeMessage<'_> {
/// Write message to the given buf.
pub fn write(buf: &mut BytesMut, message: &BeMessage<'_>) -> Result<()> {
match message {
// AuthenticationOk
// +-----+----------+-----------+
// | 'R' | int32(8) | int32(0) |
// +-----+----------+-----------+
BeMessage::AuthenticationOk => {
buf.put_u8(b'R');
buf.put_i32(8);
buf.put_i32(0);
}
// AuthenticationCleartextPassword
// +-----+----------+-----------+
// | 'R' | int32(8) | int32(3) |
// +-----+----------+-----------+
BeMessage::AuthenticationCleartextPassword => {
buf.put_u8(b'R');
buf.put_i32(8);
buf.put_i32(3);
}
// AuthenticationMD5Password
// +-----+----------+-----------+----------------+
// | 'R' | int32(12) | int32(5) | Byte4(salt) |
// +-----+----------+-----------+----------------+
//
// The 4-byte random salt will be used by client to send encrypted password as
// concat('md5', md5(concat(md5(concat(password, username)), random-salt))).
BeMessage::AuthenticationMd5Password(salt) => {
buf.put_u8(b'R');
buf.put_i32(12);
buf.put_i32(5);
buf.put_slice(&salt[..]);
}
// ParameterStatus
// +-----+-----------+----------+------+-----------+------+
// | 'S' | int32 len | str name | '\0' | str value | '\0' |
// +-----+-----------+----------+------+-----------+------+
BeMessage::ParameterStatus(param) => {
use BeParameterStatusMessage::*;
let [name, value] = match param {
ClientEncoding(val) => [b"client_encoding", val.as_bytes()],
StandardConformingString(val) => {
[b"standard_conforming_strings", val.as_bytes()]
}
ServerVersion(val) => [b"server_version", val.as_bytes()],
ApplicationName(val) => [b"application_name", val.as_bytes()],
};
// Parameter names and values are passed as null-terminated strings
let iov = &mut [name, b"\0", value, b"\0"].map(IoSlice::new);
let mut buffer = vec![];
let cnt = buffer.write_vectored(iov).unwrap();
buf.put_u8(b'S');
write_body(buf, |stream| {
stream.put_slice(&buffer[..cnt]);
Ok(())
})
.unwrap();
}
// CommandComplete
// +-----+-----------+-----------------+
// | 'C' | int32 len | str commandTag |
// +-----+-----------+-----------------+
BeMessage::CommandComplete(cmd) => {
let rows_cnt = cmd.rows_cnt;
let mut stmt_type = cmd.stmt_type;
let mut tag = "".to_owned();
stmt_type = match stmt_type {
StatementType::INSERT_RETURNING => StatementType::INSERT,
StatementType::DELETE_RETURNING => StatementType::DELETE,
StatementType::UPDATE_RETURNING => StatementType::UPDATE,
s => s,
};
tag.push_str(&stmt_type.to_string());
if stmt_type == StatementType::INSERT {
tag.push_str(" 0");
}
if stmt_type.is_command() {
tag.push(' ');
tag.push_str(&rows_cnt.to_string());
}
buf.put_u8(b'C');
write_body(buf, |buf| {
write_cstr(buf, tag.as_bytes())?;
Ok(())
})?;
}
// NoticeResponse
// +-----+-----------+------------------+------------------+
// | 'N' | int32 len | byte1 field type | str field value |
// +-----+-----------+------------------+-+----------------+
// description of the fields can be found here:
// https://www.postgresql.org/docs/current/protocol-error-fields.html
BeMessage::NoticeResponse(notice) => {
buf.put_u8(b'N');
write_err_or_notice(buf, &ErrorOrNoticeMessage::notice(notice))?;
}
// DataRow
// +-----+-----------+--------------+--------+-----+--------+
// | 'D' | int32 len | int16 colNum | column | ... | column |
// +-----+-----------+--------------+----+---+-----+--------+
// |
// +-----------+v------+
// | int32 len | bytes |
// +-----------+-------+
BeMessage::DataRow(vals) => {
buf.put_u8(b'D');
write_body(buf, |buf| {
buf.put_u16(vals.len() as u16); // num of cols
for val_opt in vals.values() {
if let Some(val) = val_opt {
buf.put_u32(val.len() as u32);
buf.put_slice(val);
} else {
buf.put_i32(-1);
}
}
Ok(())
})
.unwrap();
}
// RowDescription
// +-----+-----------+--------------+-------+-----+-------+
// | 'T' | int32 len | int16 colNum | field | ... | field |
// +-----+-----------+--------------+----+--+-----+-------+
// |
// +---------------+-------+-------+-----v-+-------+-------+-------+
// | str fieldName | int32 | int16 | int32 | int16 | int32 | int16 |
// +---------------+---+---+---+---+---+---+----+--+---+---+---+---+
// | | | | | |
// v | v v | v
// tableOID | typeOID typeLen | formatCode
// v v
// colAttrNum typeModifier
BeMessage::RowDescription(row_descs) => {
buf.put_u8(b'T');
write_body(buf, |buf| {
buf.put_i16(row_descs.len() as i16); // # of fields
for pg_field in *row_descs {
write_cstr(buf, pg_field.get_name().as_bytes())?;
buf.put_i32(pg_field.get_table_oid()); // table oid
buf.put_i16(pg_field.get_col_attr_num()); // attnum
buf.put_i32(pg_field.get_type_oid());
buf.put_i16(pg_field.get_type_len());
buf.put_i32(pg_field.get_type_modifier()); // typmod
buf.put_i16(pg_field.get_format_code()); // format code
}
Ok(())
})?;
}
// ReadyForQuery
// +-----+----------+---------------------------+
// | 'Z' | int32(5) | byte1(transaction status) |
// +-----+----------+---------------------------+
BeMessage::ReadyForQuery(txn_status) => {
buf.put_u8(b'Z');
buf.put_i32(5);
// TODO: add transaction status
buf.put_u8(match txn_status {
TransactionStatus::Idle => b'I',
TransactionStatus::InTransaction => b'T',
TransactionStatus::InFailedTransaction => b'E',
});
}
BeMessage::ParseComplete => {
buf.put_u8(b'1');
write_body(buf, |_| Ok(()))?;
}
BeMessage::BindComplete => {
buf.put_u8(b'2');
write_body(buf, |_| Ok(()))?;
}
BeMessage::CloseComplete => {
buf.put_u8(b'3');
write_body(buf, |_| Ok(()))?;
}
BeMessage::PortalSuspended => {
buf.put_u8(b's');
write_body(buf, |_| Ok(()))?;
}
// ParameterDescription
// +-----+-----------+--------------------+---------------+-----+---------------+
// | 't' | int32 len | int16 ParameterNum | int32 typeOID | ... | int32 typeOID |
// +-----+-----------+-----------------+--+---------------+-----+---------------+
BeMessage::ParameterDescription(para_descs) => {
buf.put_u8(b't');
write_body(buf, |buf| {
buf.put_i16(para_descs.len() as i16);
for oid in *para_descs {
buf.put_i32(*oid);
}
Ok(())
})?;
}
BeMessage::NoData => {
buf.put_u8(b'n');
write_body(buf, |_| Ok(())).unwrap();
}
BeMessage::EncryptionResponseSsl => {
buf.put_u8(b'S');
}
BeMessage::EncryptionResponseGss => {
buf.put_u8(b'G');
}
BeMessage::EncryptionResponseNo => {
buf.put_u8(b'N');
}
// EmptyQueryResponse
// +-----+----------+
// | 'I' | int32(4) |
// +-----+----------+
BeMessage::EmptyQueryResponse => {
buf.put_u8(b'I');
buf.put_i32(4);
}
BeMessage::ErrorResponse(error) => {
use thiserror_ext::AsReport;
// For all the errors set Severity to Error and error code to
// 'internal error'.
// 'E' signalizes ErrorResponse messages
buf.put_u8(b'E');
// Format the error as a pretty report.
let msg = error.to_report_string_pretty();
write_err_or_notice(buf, &ErrorOrNoticeMessage::internal_error(&msg))?;
}
BeMessage::BackendKeyData((process_id, secret_key)) => {
buf.put_u8(b'K');
write_body(buf, |buf| {
buf.put_i32(*process_id);
buf.put_i32(*secret_key);
Ok(())
})?;
}
}
Ok(())
}
}
// Safe usize -> i32|i16 conversion, from rust-postgres
trait FromUsize: Sized {
fn from_usize(x: usize) -> Result<Self>;
}
macro_rules! from_usize {
($t:ty) => {
impl FromUsize for $t {
#[inline]
fn from_usize(x: usize) -> Result<$t> {
if x > <$t>::MAX as usize {
Err(Error::new(ErrorKind::InvalidInput, "value too large to transmit").into())
} else {
Ok(x as $t)
}
}
}
};
}
from_usize!(i32);
/// Call f() to write body of the message and prepend it with 4-byte len as
/// prescribed by the protocol. First write out body value and fill length value as i32 in front of
/// it.
fn write_body<F>(buf: &mut BytesMut, f: F) -> Result<()>
where
F: FnOnce(&mut BytesMut) -> Result<()>,
{
let base = buf.len();
buf.extend_from_slice(&[0; 4]);
f(buf)?;
let size = i32::from_usize(buf.len() - base)?;
BigEndian::write_i32(&mut buf[base..], size);
Ok(())
}
/// Safe write of s into buf as cstring (String in the protocol).
fn write_cstr(buf: &mut BytesMut, s: &[u8]) -> Result<()> {
if s.contains(&0) {
return Err(Error::new(
ErrorKind::InvalidInput,
"string contains embedded null",
));
}
buf.put_slice(s);
buf.put_u8(0);
Ok(())
}
/// Safe write error or notice message.
fn write_err_or_notice(buf: &mut BytesMut, msg: &ErrorOrNoticeMessage<'_>) -> Result<()> {
write_body(buf, |buf| {
buf.put_u8(b'S'); // severity
write_cstr(buf, msg.severity.as_str().as_bytes())?;
buf.put_u8(b'C'); // SQLSTATE error code
write_cstr(buf, msg.state.code().as_bytes())?;
buf.put_u8(b'M'); // the message
write_cstr(buf, msg.message.as_bytes())?;
buf.put_u8(0); // terminator
Ok(())
})
}
#[cfg(test)]
mod tests {
use bytes::Bytes;
use crate::pg_message::FeQueryMessage;
#[test]
fn test_get_sql() {
let fe = FeQueryMessage {
sql_bytes: Bytes::from(vec![255, 255, 255, 255, 255, 255, 0]),
};
assert!(fe.get_sql().is_err(), "{}", true);
let fe = FeQueryMessage {
sql_bytes: Bytes::from(vec![1, 2, 3, 4, 5, 6, 7, 8]),
};
assert!(fe.get_sql().is_err(), "{}", true);
}
}