local.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# Copyright 2012-2015 clowwindy
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

from __future__ import absolute_import, division, print_function, \
    with_statement

import sys
import os
import logging
import signal

sys.path.insert(0, os.path.join(os.path.dirname(__file__), '../'))
from shadowsocks import shell, daemon, eventloop, tcprelay, udprelay, asyncdns

@shell.exception_handle(self_=False, exit_code=1)
def main():
    shell.check_python()

    # fix py2exe 检测是不是转为了可执行文件 转化了重新设定操作目录至可执行文件下
    if hasattr(sys, "frozen") and sys.frozen in \
            ("windows_exe", "console_exe"):
        p = os.path.dirname(os.path.abspath(sys.executable))
        os.chdir(p)

    config = shell.get_config(True)#true说明是本地local程序 调用checkconfig 进一步调用encrypt.py相关
    #返回的是字典
    #config['forbidden_ip']在shell.get_config在调用时
    daemon.daemon_exec(config)#生成子进程把父进程kill了，然后写入pidfile，加独占锁，并多次通知父进程kill，成为真正的进程

    logging.info("starting local at %s:%d" %
                 (config['local_address'], config['local_port']))

    dns_resolver = asyncdns.DNSResolver()
    tcp_server = tcprelay.TCPRelay(config, dns_resolver, True)
    udp_server = udprelay.UDPRelay(config, dns_resolver, True)
    loop = eventloop.EventLoop()
    dns_resolver.add_to_loop(loop)
    tcp_server.add_to_loop(loop)
    udp_server.add_to_loop(loop)

    def handler(signum, _):
        logging.warn('received SIGQUIT, doing graceful shutting down..')
        tcp_server.close(next_tick=True)
        udp_server.close(next_tick=True)
    signal.signal(getattr(signal, 'SIGQUIT', signal.SIGTERM), handler)#非阻塞 收到信号执行

    def int_handler(signum, _):
        sys.exit(1)
    signal.signal(signal.SIGINT, int_handler)

    daemon.set_user(config.get('user', None))
    loop.run()

if __name__ == '__main__':
    main()