Files
DECNET/templates/tftp/server.py
anti cf1e00af28 Add per-service customization, stealth hardening, and BYOS support
- HTTP: configurable server_header, response_code, fake_app presets
  (apache/nginx/wordpress/phpmyadmin/iis), extra_headers, custom_body,
  static files directory mount
- SSH/Cowrie: configurable kernel_version, hardware_platform, ssh_banner,
  and users/passwords via COWRIE_USERDB_ENTRIES; switched to build mode
  so cowrie.cfg.j2 persona fields and userdb.txt generation work
- SMTP: configurable banner and MTA hostname
- MySQL: configurable version string in protocol greeting
- Redis: configurable redis_version and os string in INFO response
- BYOS: [custom-*] INI sections define bring-your-own Docker services
- Stealth: rename all *_honeypot.py → server.py; replace HONEYPOT_NAME
  env var with NODE_NAME across all 22+ service templates and plugins;
  strip "honeypot" from all in-container file content
- Config: DeckyConfig.service_config dict; INI [decky-N.svc] subsections;
  composer passes service_cfg to compose_fragment
- 350 tests passing (100%)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-04 04:08:27 -03:00

97 lines
2.6 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
NODE_NAME = os.environ.get("NODE_NAME", "tftpserver")
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 _forward(event: dict) -> None:
if not LOG_TARGET:
return
try:
host, port = LOG_TARGET.rsplit(":", 1)
with socket.create_connection((host, int(port)), timeout=3) as s:
s.sendall((json.dumps(event) + "\n").encode())
except Exception:
pass
def _log(event_type: str, **kwargs) -> None:
event = {
"ts": datetime.now(timezone.utc).isoformat(),
"service": "tftp",
"host": NODE_NAME,
"event": event_type,
**kwargs,
}
print(json.dumps(event), flush=True)
_forward(event)
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())