Files
DECNET/templates/mysql/server.py
anti 8335c5dc4c fix: remove duplicate print() in _log() across all service templates
Every service's _log() called print() then write_syslog_file() which also
calls print(), causing every log line to appear twice in Docker logs. The
collector streamed both copies, doubling ingested events. Removed the
redundant print() from all 22 service server.py files.
2026-04-14 00:16:18 -04:00

112 lines
4.1 KiB
Python

#!/usr/bin/env python3
"""
MySQLserver.
Sends a realistic MySQL 5.7 server handshake, reads the client login
packet, extracts username, then closes with Access Denied. Logs auth
attempts as JSON.
"""
import asyncio
import os
import struct
from decnet_logging import syslog_line, write_syslog_file, forward_syslog
NODE_NAME = os.environ.get("NODE_NAME", "dbserver")
SERVICE_NAME = "mysql"
LOG_TARGET = os.environ.get("LOG_TARGET", "")
PORT = int(os.environ.get("PORT", "3306"))
_MYSQL_VER = os.environ.get("MYSQL_VERSION", "5.7.38-log")
# Minimal MySQL server greeting (protocol v10) — version string is configurable
_GREETING = (
b"\x0a" # protocol version 10
+ _MYSQL_VER.encode() + b"\x00" # server version + NUL
+ b"\x01\x00\x00\x00" # connection id = 1
+ b"\x70\x76\x21\x6d\x61\x67\x69\x63" # auth-plugin-data part 1
+ b"\x00" # filler
+ b"\xff\xf7" # capability flags low
+ b"\x21" # charset utf8
+ b"\x02\x00" # status flags
+ b"\xff\x81" # capability flags high
+ b"\x15" # auth plugin data length
+ b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" # reserved (10 bytes)
+ b"\x21\x4f\x7d\x25\x3e\x55\x4d\x7c\x67\x75\x5e\x31\x00" # auth part 2
+ b"mysql_native_password\x00" # auth plugin name
)
def _make_packet(payload: bytes, seq: int = 0) -> bytes:
length = len(payload)
return struct.pack("<I", length)[:3] + bytes([seq]) + payload
def _log(event_type: str, severity: int = 6, **kwargs) -> None:
line = syslog_line(SERVICE_NAME, NODE_NAME, event_type, severity, **kwargs)
write_syslog_file(line)
forward_syslog(line, LOG_TARGET)
class MySQLProtocol(asyncio.Protocol):
def __init__(self):
self._transport = None
self._peer = None
self._buf = b""
self._greeted = False
def connection_made(self, transport):
self._transport = transport
self._peer = transport.get_extra_info("peername", ("?", 0))
_log("connect", src=self._peer[0], src_port=self._peer[1])
transport.write(_make_packet(_GREETING, seq=0))
self._greeted = True
def data_received(self, data):
self._buf += data
# MySQL packets: 3-byte length + 1-byte seq + payload
while len(self._buf) >= 4:
length = struct.unpack("<I", self._buf[:3] + b"\x00")[0]
if length > 1024 * 1024:
self._transport.close()
self._buf = b""
return
if len(self._buf) < 4 + length:
break
payload = self._buf[4:4 + length]
self._buf = self._buf[4 + length:]
self._handle_packet(payload)
def _handle_packet(self, payload: bytes):
if not payload:
return
# Login packet: capability flags (4), max_packet (4), charset (1), reserved (23), username (NUL-terminated)
if len(payload) > 32:
try:
# skip capability(4) + max_pkt(4) + charset(1) + reserved(23) = 32 bytes
username_start = 32
nul = payload.index(b"\x00", username_start)
username = payload[username_start:nul].decode(errors="replace")
except (ValueError, IndexError):
username = "<parse_error>"
_log("auth", src=self._peer[0], username=username)
# Send Access Denied error
err = b"\xff" + struct.pack("<H", 1045) + b"#28000Access denied for user\x00"
self._transport.write(_make_packet(err, seq=2))
self._transport.close()
def connection_lost(self, exc):
_log("disconnect", src=self._peer[0] if self._peer else "?")
async def main():
_log("startup", msg=f"MySQL server starting as {NODE_NAME}")
loop = asyncio.get_running_loop()
server = await loop.create_server(MySQLProtocol, "0.0.0.0", PORT) # nosec B104
async with server:
await server.serve_forever()
if __name__ == "__main__":
asyncio.run(main())