Files
DECNET/templates/tftp/server.py
anti 55896b0caa Add RFC 5424 syslog logging to all service templates
- decnet/logging/syslog_formatter.py: RFC 5424 formatter (local0 facility,
  decnet@55555 SD element ID, full escaping per §6.3.3)
- decnet/logging/file_handler.py: rotating file handler (10 MB / 5 backups),
  path configurable via DECNET_LOG_FILE env var
- templates/decnet_logging.py: combined syslog_line / write_syslog_file /
  forward_syslog helper distributed to all 22 service template dirs
- All templates/*/server.py: replaced ad-hoc JSON _forward/_log with RFC 5424
  syslog_line + write_syslog_file + forward_syslog
- All templates/*/Dockerfile: COPY decnet_logging.py /opt/
- DecnetConfig: added log_file field; CLI: --log-file flag;
  composer injects DECNET_LOG_FILE env var into service containers
- tests/test_syslog_formatter.py + tests/test_file_handler.py: 25 new tests

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-04 04:31:00 -03:00

85 lines
2.4 KiB
Python

#!/usr/bin/env python3
"""
TFTP server (UDP 69).
Parses RRQ (read) and WRQ (write) requests, logs filename and transfer mode,
then responds with an error packet. Logs all requests as JSON.
"""
import asyncio
import json
import os
import socket
import struct
from datetime import datetime, timezone
from decnet_logging import syslog_line, write_syslog_file, forward_syslog
NODE_NAME = os.environ.get("NODE_NAME", "tftpserver")
SERVICE_NAME = "tftp"
LOG_TARGET = os.environ.get("LOG_TARGET", "")
# TFTP opcodes
_RRQ = 1
_WRQ = 2
_ERROR = 5
# TFTP Error packet: opcode(2) + error_code(2) + error_msg + NUL
def _error_pkt(code: int, msg: str) -> bytes:
return struct.pack(">HH", _ERROR, code) + msg.encode() + b"\x00"
def _log(event_type: str, severity: int = 6, **kwargs) -> None:
line = syslog_line(SERVICE_NAME, NODE_NAME, event_type, severity, **kwargs)
print(line, flush=True)
write_syslog_file(line)
forward_syslog(line, LOG_TARGET)
class TFTPProtocol(asyncio.DatagramProtocol):
def __init__(self):
self._transport = None
def connection_made(self, transport):
self._transport = transport
def datagram_received(self, data: bytes, addr):
if len(data) < 4:
return
opcode = struct.unpack(">H", data[:2])[0]
if opcode in (_RRQ, _WRQ):
# Filename and mode are NUL-terminated strings after the opcode
parts = data[2:].split(b"\x00")
filename = parts[0].decode(errors="replace") if parts else ""
mode = parts[1].decode(errors="replace") if len(parts) > 1 else ""
_log(
"request",
src=addr[0],
src_port=addr[1],
op="RRQ" if opcode == _RRQ else "WRQ",
filename=filename,
mode=mode,
)
self._transport.sendto(_error_pkt(2, "Access violation"), addr)
else:
_log("unknown_opcode", src=addr[0], opcode=opcode, data=data[:32].hex())
def error_received(self, exc):
pass
async def main():
_log("startup", msg=f"TFTP server starting as {NODE_NAME}")
loop = asyncio.get_running_loop()
transport, _ = await loop.create_datagram_endpoint(
TFTPProtocol, local_addr=("0.0.0.0", 69)
)
try:
await asyncio.sleep(float("inf"))
finally:
transport.close()
if __name__ == "__main__":
asyncio.run(main())