nuVistA/protoswitch.py

72 lines
2.4 KiB
Python

#!/usr/bin/env python3
import socket
import io
from werkzeug.serving import WSGIRequestHandler
from typing import Iterator
import logging
logger = logging.getLogger(__name__)
handler = logging.StreamHandler()
handler.setFormatter(logging.Formatter('%(asctime)s:%(levelname)s\t%(message)s'))
logger.addHandler(handler)
logger.setLevel(logging.DEBUG)
bEOT = b'\x04'
class SwitchingRequestHandler(WSGIRequestHandler):
def parse_request(self):
if self.raw_requestline.startswith(b'[XWB]'):
logger.info(f"{self.client_address[0]}:{self.client_address[1]} VistA OPEN")
proxy_vista(read_from_file(self.rfile, self.raw_requestline), self.wfile, self.client_address, ('test.northport.med.va.gov', 19009))
logger.info(f"{self.client_address[0]}:{self.client_address[1]} VistA CLOSE")
return False
return WSGIRequestHandler.parse_request(self)
def proxy_vista(rfilegen: Iterator[bytes], wfile: io.BufferedWriter, localaddr: tuple, remoteaddr: tuple) -> None:
remotesock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
remotesock.connect(remoteaddr)
recipient = recv_from_socket(remotesock)
for n, req in enumerate(rfilegen):
logger.debug(f"{localaddr[0]}:{localaddr[1]} #{n}{req.decode('latin-1').encode('unicode-escape').decode()}")
remotesock.send(req + bEOT)
res = next(recipient)
for line in res.decode('latin-1').splitlines(keepends=True):
logger.debug(f"{localaddr[0]}:{localaddr[1]} #{n}{line.encode('unicode-escape').decode()}")
wfile.write(res + bEOT)
remotesock.shutdown(socket.SHUT_RDWR)
remotesock.close()
def read_from_file(rfile: io.BufferedReader, buf: bytes=b'', end: bytes=bEOT, minsz: int=1024, maxsz: int=32768) -> Iterator[bytes]:
if len(buf) > 0:
while (idx := buf.find(end)) >= 0:
if idx > 0:
yield buf[:idx]
buf = buf[idx + 1:]
bufsz = minsz
while len(data := rfile.read1(bufsz)) > 0:
buf += data
while (idx := buf.find(end)) >= 0:
if idx > 0:
yield buf[:idx]
bufsz = minsz
elif bufsz < maxsz:
bufsz = _x if (_x := bufsz << 1) < maxsz else maxsz
buf = buf[idx + 1:]
def recv_from_socket(sock: socket.socket, end: bytes=bEOT, minsz: int=1024, maxsz: int=32768) -> Iterator[bytes]:
buf = b''
bufsz = minsz
while True:
if len(data := sock.recv(bufsz)) > 0:
buf += data
while (idx := buf.find(end)) >= 0:
if idx > 0:
yield buf[:idx]
bufsz = minsz
elif bufsz < maxsz:
bufsz = _x if (_x := bufsz << 1) < maxsz else maxsz
buf = buf[idx + 1:]