source: ogClient-Git/src/ogClient.py @ cc0d987

#
# Copyright (C) 2020-2021 Soleta Networks <info@soleta.eu>
#
# This program is free software: you can redistribute it and/or modify it under
# the terms of the GNU Affero General Public License as published by the
# Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.

import errno
import select
import socket
import time
import email
import platform
from io import StringIO

from src.restRequest import *
from src.ogRest import *
from enum import Enum

class State(Enum):
        CONNECTING = 0
        RECEIVING = 1
        FORCE_DISCONNECTED = 2

class ogClient:
        OG_PATH = '/opt/opengnsys/'

        def __init__(self, config):
                self.CONFIG = config

                self.mode = self.CONFIG['opengnsys']['mode']
                if self.mode not in {'virtual', 'live'}:
                        raise ValueError('Mode not supported.')

                if self.CONFIG['samba']['activate']:
                        assert('user' in self.CONFIG['samba'])
                        assert('pass' in self.CONFIG['samba'])

                self.ip = self.CONFIG['opengnsys']['ip']
                self.port = self.CONFIG['opengnsys']['port']
                self.ogrest = ogRest(self.CONFIG)

        def get_socket(self):
                return self.sock

        def get_state(self):
                return self.state

        def cleanup(self):
                self.data = ""
                self.content_len = 0
                self.header_len = 0
                self.trailer = False

        def connect(self):
                print('connecting...')
                self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                self.sock.setblocking(0)
                self.sock.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)
                self.sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPIDLE, 60)
                self.sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPINTVL, 30)
                self.sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPCNT, 4)

                self.state = State.CONNECTING
                self.cleanup()

                try:
                        self.sock.connect((self.ip, self.port))
                except socket.error as err:
                        if err.errno == errno.EINPROGRESS:
                                return
                        elif err.errno == errno.ECONNREFUSED:
                                return

        def send(self, msg):
                self.sock.send(bytes(msg, 'utf-8'))
                return len(msg)

        def connect2(self):
                try:
                        self.sock.connect((self.ip, self.port))
                except socket.error as err:
                        if err.errno == errno.EISCONN:
                                print('connected')
                                self.state = State.RECEIVING
                        else:
                                time.sleep(1)
                                print('connection refused, retrying...')
                                self.state = State.CONNECTING
                                self.sock.close()
                                self.connect()

        def receive(self):
                try:
                        data = self.sock.recv(1024).decode('utf-8')
                except socket.error as err:
                        data = ''
                        print('failed to received ' + str(err))

                if len(data) == 0:
                        self.sock.close()
                        self.connect()
                        return

                self.data = self.data + data
                request = restRequest()

                if not self.trailer:
                        header_len = self.data.find("\r\n\r\n")
                        if header_len > 0:
                                # https://stackoverflow.com/questions/4685217/parse-raw-http-headers
                                request_line, headers_alone = self.data.split('\n', 1)
                                headers = email.message_from_file(StringIO(headers_alone))

                                if 'Content-Length' in headers.keys():
                                        self.content_len = int(headers['Content-Length'])

                                self.trailer = True
                                # Add 4 because self.data.find("\r\n\r\n") does not count
                                # "\r\n\r\n" for the length
                                self.header_len = header_len + 4

                if self.trailer and (len(self.data) >= self.content_len + self.header_len):
                        request.parser(self.data)
                        self.ogrest.process_request(request, self)
                        self.cleanup()

        def disconnect(self):
                self.state = State.FORCE_DISCONNECTED
                self.sock.shutdown(socket.SHUT_RDWR)
                self.sock.close()

        def run(self):
                while 1:
                        sock = self.get_socket()
                        state = self.get_state()

                        if state == State.CONNECTING:
                                readset = [ sock ]
                                writeset = [ sock ]
                        elif state == State.FORCE_DISCONNECTED:
                                return 0
                        else:
                                readset = [ sock ]
                                writeset = [ ]

                        readable, writable, exception = select.select(readset, writeset, [ ])
                        if state == State.CONNECTING and sock in writable:
                                self.connect2()
                        elif state == State.RECEIVING and sock in readable:
                                self.receive()
                        else:
                                print('wrong state, not ever happen!' + str(state))