Files
DECNET/templates/tftp/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

81 lines
2.3 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 os
import struct
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)
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) # nosec B104
)
try:
await asyncio.sleep(float("inf"))
finally:
transport.close()
if __name__ == "__main__":
asyncio.run(main())