From fddc47368fba6a65e33b14ec8d1a11a755c5f0ab Mon Sep 17 00:00:00 2001 From: Kali Kaneko Date: Wed, 7 May 2014 16:56:56 -0500 Subject: daemonize calls to resolvconf. Closes: #5618 --- pkg/linux/bitmask-root | 202 ++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 181 insertions(+), 21 deletions(-) (limited to 'pkg/linux') diff --git a/pkg/linux/bitmask-root b/pkg/linux/bitmask-root index c1a2adfd..78503af9 100755 --- a/pkg/linux/bitmask-root +++ b/pkg/linux/bitmask-root @@ -32,14 +32,15 @@ The `openvpn start` action is special: it calls exec on openvpn and replaces the current process. """ # TODO should be tested with python3, which can be the default on some distro. - from __future__ import print_function +import atexit import os import re import signal import socket import subprocess import sys +import time import traceback @@ -227,6 +228,135 @@ def get_process_list(): return filter(None, res) +class Daemon(object): + """ + A generic daemon class. + """ + def __init__(self, pidfile, stdin='/dev/null', + stdout='/dev/null', stderr='/dev/null'): + self.stdin = stdin + self.stdout = stdout + self.stderr = stderr + self.pidfile = pidfile + + def daemonize(self): + """ + Do the UNIX double-fork magic, see Stevens' "Advanced + Programming in the UNIX Environment" for details (ISBN 0201563177) + http://www.erlenstar.demon.co.uk/unix/faq_2.html#SEC16 + """ + try: + pid = os.fork() + if pid > 0: + # exit first parent + sys.exit(0) + except OSError, e: + sys.stderr.write( + "fork #1 failed: %d (%s)\n" % (e.errno, e.strerror)) + sys.exit(1) + + # decouple from parent environment + os.chdir("/") + os.setsid() + os.umask(0) + + # do second fork + try: + pid = os.fork() + if pid > 0: + # exit from second parent + sys.exit(0) + except OSError, e: + sys.stderr.write( + "fork #2 failed: %d (%s)\n" % (e.errno, e.strerror)) + sys.exit(1) + + # redirect standard file descriptors + sys.stdout.flush() + sys.stderr.flush() + si = file(self.stdin, 'r') + so = file(self.stdout, 'a+') + se = file(self.stderr, 'a+', 0) + os.dup2(si.fileno(), sys.stdin.fileno()) + os.dup2(so.fileno(), sys.stdout.fileno()) + os.dup2(se.fileno(), sys.stderr.fileno()) + + # write pidfile + atexit.register(self.delpid) + pid = str(os.getpid()) + file(self.pidfile, 'w+').write("%s\n" % pid) + + def delpid(self): + """ + Delete the pidfile. + """ + os.remove(self.pidfile) + + def start(self, *args): + """ + Start the daemon. + """ + # Check for a pidfile to see if the daemon already runs + try: + pf = file(self.pidfile, 'r') + pid = int(pf.read().strip()) + pf.close() + except IOError: + pid = None + + if pid: + message = "pidfile %s already exist. Daemon already running?\n" + sys.stderr.write(message % self.pidfile) + sys.exit(1) + + # Start the daemon + self.daemonize() + self.run(args) + + def stop(self): + """ + Stop the daemon. + """ + # Get the pid from the pidfile + try: + pf = file(self.pidfile, 'r') + pid = int(pf.read().strip()) + pf.close() + except IOError: + pid = None + + if not pid: + message = "pidfile %s does not exist. Daemon not running?\n" + sys.stderr.write(message % self.pidfile) + return # not an error in a restart + + # Try killing the daemon process + try: + while 1: + os.kill(pid, signal.SIGTERM) + time.sleep(0.1) + except OSError, err: + err = str(err) + if err.find("No such process") > 0: + if os.path.exists(self.pidfile): + os.remove(self.pidfile) + else: + print(str(err)) + sys.exit(1) + + def restart(self): + """ + Restart the daemon. + """ + self.stop() + self.start() + + def run(self): + """ + This should be overridden by derived classes. + """ + + def run(command, *args, **options): """ Run an external command. @@ -383,29 +513,59 @@ def openvpn_stop(args): ## -def set_dns_nameserver(ip_address): +class NameserverSetter(Daemon): """ - Add the tunnel DNS server to `resolv.conf` - - :param ip_address: the ip to add to `resolv.conf` - :type ip_address: str + A daemon that will add leap nameserver inside the tunnel + to the system `resolv.conf` """ - if os.path.isfile(RESOLVCONF): - process = run(RESOLVCONF, "-a", "bitmask", input=True) - process.communicate("nameserver %s\n" % ip_address) - else: - bail("ERROR: package openresolv or resolvconf not installed.") + def run(self, *args): + """ + Run when daemonized. + """ + if args: + ip_address = args[0] + self.set_dns_nameserver(ip_address) + + def set_dns_nameserver(self, ip_address): + """ + Add the tunnel DNS server to `resolv.conf` + + :param ip_address: the ip to add to `resolv.conf` + :type ip_address: str + """ + if os.path.isfile(RESOLVCONF): + process = run(RESOLVCONF, "-a", "bitmask", input=True) + process.communicate("nameserver %s\n" % ip_address) + else: + bail("ERROR: package openresolv or resolvconf not installed.") + +nameserver_setter = NameserverSetter('/tmp/leap-dns-up.pid') -def restore_dns_nameserver(): + +class NameserverRestorer(Daemon): """ - Remove tunnel DNS server from `resolv.conf` + A daemon that will restore the previous nameservers. """ - if os.path.isfile(RESOLVCONF): - run(RESOLVCONF, "-d", "bitmask") - else: - print("%s: ERROR: package openresolv or resolvconf not installed." % - (SCRIPT,)) + + def run(self): + """ + Run when daemonized. + """ + self.restore_dns_nameserver() + + def restore_dns_nameserver(self): + """ + Remove tunnel DNS server from `resolv.conf` + """ + if os.path.isfile(RESOLVCONF): + run(RESOLVCONF, "-d", "bitmask") + else: + print("%s: ERROR: package openresolv " + "or resolvconf not installed." % + (SCRIPT,)) + +nameserver_restorer = NameserverRestorer('/tmp/leap-dns-down.pid') ## @@ -619,16 +779,16 @@ def main(): elif command == "firewall_start": try: firewall_start(args) - set_dns_nameserver(NAMESERVER) + nameserver_setter.start(NAMESERVER) except Exception as ex: - restore_dns_nameserver() + nameserver_restorer.start() firewall_stop() bail("ERROR: could not start firewall", ex) elif command == "firewall_stop": try: - restore_dns_nameserver() firewall_stop() + nameserver_restorer.start() except Exception as ex: bail("ERROR: could not stop firewall", ex) -- cgit v1.2.3