spicetools/api/resources/python/spiceapi/connection.py

140 lines
4.0 KiB
Python

import os
import socket
from .request import Request
from .response import Response
from .rc4 import rc4
from .exceptions import MalformedRequestException, APIError
class Connection:
""" Container for managing a single connection to the API server.
"""
def __init__(self, host: str, port: int, password: str):
"""Default constructor.
:param host: the host string to connect to
:param port: the port of the host
:param password: the connection password string
"""
self.host = host
self.port = port
self.password = password
self.socket = None
self.cipher = None
self.reconnect()
def reconnect(self, refresh_session=True):
"""Reconnect to the server.
This opens a new connection and closes the previous one, if existing.
"""
# close old socket
self.close()
# create new socket
self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.socket.settimeout(3)
self.socket.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
self.socket.connect((self.host, self.port))
# cipher
self.change_password(self.password)
# refresh session
if refresh_session:
from .control import control_session_refresh
control_session_refresh(self)
def change_password(self, password):
"""Allows to change the password on the fly.
The cipher will be rebuilt.
"""
if len(password) > 0:
self.cipher = rc4(password.encode("UTF-8"))
else:
self.cipher = None
def close(self):
"""Close the active connection, if existing."""
# check if socket is existing
if self.socket:
# close and delete socket
self.socket.close()
self.socket = None
def request(self, request: Request):
"""Send a request to the server and receive the answer.
:param request: request object
:return: response object
"""
# check if disconnected
if not self.socket:
raise RuntimeError("No active connection.")
# build data
data = request.to_json().encode("UTF-8") + b"\x00"
if self.cipher:
data_list = list(data)
data_cipher = []
for b in data_list:
data_cipher.append(b ^ next(self.cipher))
data = bytes(data_cipher)
# send request
if os.name != 'nt':
self.socket.setsockopt(socket.IPPROTO_TCP, socket.TCP_QUICKACK, 1)
self.socket.send(data)
# get answer
answer_data = []
while not len(answer_data) or answer_data[-1] != 0:
# receive data
if os.name != 'nt':
self.socket.setsockopt(socket.IPPROTO_TCP, socket.TCP_QUICKACK, 1)
receive_data = self.socket.recv(4096)
# check length
if len(receive_data):
# check cipher
if self.cipher:
# add decrypted data
for b in receive_data:
answer_data.append(int(b ^ next(self.cipher)))
else:
# add plaintext
for b in receive_data:
answer_data.append(int(b))
else:
raise RuntimeError("Connection was closed.")
# check for empty response
if len(answer_data) <= 1:
# empty response means the JSON couldn't be parsed
raise MalformedRequestException()
# build response
response = Response(bytes(answer_data[:-1]).decode("UTF-8"))
if len(response.get_errors()):
raise APIError(response.get_errors())
# check ID
req_id = request.get_id()
res_id = response.get_id()
if req_id != res_id:
raise RuntimeError(f"Unexpected response ID: {res_id} (expected {req_id})")
# return response object
return response