#!/usr/bin/env python3.1
import configparser, optparse, os, postgresql.api, re, sys, _thread
# wrapper around syslog, can be muted
class Logger:
__slots__ = frozenset(['_syslog'])
def __init__(self):
config.section('log')
if config['silent'] == 'yes':
self._syslog = None
else:
import syslog
self._syslog = syslog
self._syslog.openlog('squidTag')
def info(self, message):
if self._syslog:
self._syslog.syslog(self._syslog.LOG_INFO, message)
def notice(self, message):
if self._syslog:
self._syslog.syslog(self._syslog.LOG_NOTICE, message)
# wrapper around database
class tagDB:
__slots__ = frozenset(('_check_stmt', '_db'))
def __init__(self):
config.section('database')
self._db = postgresql.open(
'pq://{}:{}@{}/{}'.format(
config['user'],
config['password'],
config['host'],
config['database'],
) )
self._check_stmt = self._db.prepare("select redirect_url, regexp from site_rule where site <@ tripdomain($1) and netmask >> $2::text::inet order by array_length(site, 1) desc")
def check(self, site, ip_address):
return(self._check_stmt(site, ip_address))
# abstract class with basic checking functionality
class Checker:
__slots__ = frozenset(['_db', '_log'])
def __init__(self):
self._db = tagDB()
self._log = Logger()
def process(self, id, site, ip_address, url_path, line = None):
self._log.info('trying {}\n'.format(site))
result = self._db.check(site, ip_address)
#reply = '{}://{}/{}'.format(req[4], req[1], req[3])
reply = '-'
for row in result:
if row != None and row[0] != None:
if row[1] != None:
self._log.info('trying regexp "{}" versus "{}"\n'.format(row[1], url_path))
try:
if re.compile(row[1]).match(url_path):
reply = row[0].format(url_path)
break
else:
continue
except:
self._log.info("can't compile regexp")
else:
reply = row[0].format(url_path)
break
self.writeline('{} {}\n'.format(id, reply))
def check(self, line):
request = re.compile('^([0-9]+)\ (http|ftp):\/\/([-\w.:]+)\/([^ ]*)\ ([0-9.]+)\/(-|[\w\.]+)\ (-|\w+)\ (-|GET|HEAD|POST).*$').match(line)
if request:
id = request.group(1)
#proto = request.group(2)
site = request.group(3)
url_path = request.group(4)
ip_address = request.group(5)
self.process(id, site, ip_address, url_path, line)
return(True)
else:
self._log.info('bad request\n')
self.writeline(line)
return(False)
def writeline(self, string):
self._log.info('sending: ' + string)
sys.stdout.write(string)
sys.stdout.flush()
def loop(self):
while True:
line = sys.stdin.readline()
if len(line) == 0:
break
self.check(line)
# threaded checking facility
class CheckerThread(Checker):
__slots__ = frozenset(['_lock', '_lock_exit', '_lock_queue', '_queue'])
def __init__(self):
# basic initialisation
Checker.__init__(self)
# Spin lock. Loop acquires it on start then releases it when holding queue
# lock. This way the thread proceeds without stops while queue has data and
# gets stalled when no data present. The lock is released by queue writer
# after storing something into the queue
self._lock = _thread.allocate_lock()
self._lock_exit = _thread.allocate_lock()
self._lock_queue = _thread.allocate_lock()
self._lock.acquire()
self._queue = []
_thread.start_new_thread(self._start, ())
def _start(self):
while True:
self._lock.acquire()
with self._lock_queue:
# yes this should be written this way, and yes, this is why I hate threading
if len(self._queue) > 1:
if self._lock.locked():
self._lock.release()
req = self._queue.pop(0)
Checker.process(self, req[0], req[1], req[2], req[3])
with self._lock_queue:
if len(self._queue) == 0:
if self._lock_exit.locked():
self._lock_exit.release()
def process(self, id, site, ip_address, url_path, line):
with self._lock_queue:
self._queue.append((id, site, ip_address, url_path))
self._log.info('request {} queued ({})\n'.format(id, line))
if not self._lock_exit.locked():
self._lock_exit.acquire()
if self._lock.locked():
self._lock.release()
def loop(self):
while True:
line = sys.stdin.readline()
if len(line) == 0:
break
self.check(line)
self._lock_exit.acquire()
# kqueue enabled class for BSD's
class CheckerKqueue(Checker):
__slots__ = frozenset(['_kq', '_select', '_queue'])
def __init__(self):
# basic initialisation
Checker.__init__(self)
# importing select module
import select
self._select = select
# kreating kqueue
self._kq = self._select.kqueue()
assert (self._kq.fileno() != -1)
# watching sys.stdin for data
self._kq.control([self._select.kevent(sys.stdin, self._select.KQ_FILTER_READ, self._select.KQ_EV_ADD)], 0)
# creating data queue
self._queue = []
def loop(self):
# Wait for data by default
timeout = None
eof = False
buffer = ''
while True:
# checking if there is any data or witing for data to arrive
kevs = self._kq.control(None, 1, timeout)
if len(kevs) > 0 and kevs[0].filter == self._select.KQ_FILTER_READ and kevs[0].data > 0:
# reading data in
new_buffer = sys.stdin.read(kevs[0].data)
# if no data was sent - we have reached and of file
if len(new_buffer) == 0:
eof = True
else:
# adding current buffer to old buffer remains
buffer += new_buffer
# splitting to lines
lines = buffer.split('\n')
# last line that was not terminate by newline returns to buffer
buffer = lines[-1]
# an only if there was at least one newline
if len(lines) > 1:
for line in lines[:-1]:
# add data to the queue
if self.check(line + '\n'):
# don't wait for more data, start processing
timeout = 0
# if kq reports en of stream refuse to read more of it
if kevs[0].flags >> 15 == 1:
eof = True
else:
if len(self._queue) > 0:
req = self._queue.pop(0)
Checker.process(self, req[0], req[1], req[2], req[3])
if len(self._queue) == 0:
# wait for data - we have nothing to process
timeout = None
elif eof:
break
def process(self, id, site, ip_address, url_path, line):
# simply adding data to the queue
self._queue.append((id, site, ip_address, url_path))
self._log.info('request {} queued ({})\n'.format(id, line))
# this classes processes config file and substitutes default values
class Config:
__slots__ = frozenset(['_config', '_default', '_section'])
_default = {
'reactor': {
'reactor': 'thread',
},
'log': {
'silent': 'no',
},
'database': {
'host': 'localhost',
'database': 'squidTag',
},}
# function to read in config file
def __init__(self):
parser = optparse.OptionParser()
parser.add_option('-c', '--config', dest = 'config',
help = 'config file location', metavar = 'FILE',
default = '/usr/local/etc/squid-tagger.conf')
(options, args) = parser.parse_args()
if not os.access(options.config, os.R_OK):
print("Can't read {}: exitting".format(options.config))
sys.exit(2)
self._config = configparser.ConfigParser()
self._config.readfp(open(options.config))
# function to select config file section or create one
def section(self, section):
if not self._config.has_section(section):
self._config.add_section(section)
self._section = section
# function to get config parameter, if parameter doesn't exists the default
# value or None is substituted
def __getitem__(self, name):
if not self._config.has_option(self._section, name):
if self._section in self._default:
if name in self._default[self._section]:
self._config.set(self._section, name, self._default[self._section][name])
else:
self._config.set(self._section, name, None)
else:
self._config.set(self._section, name, None)
return(self._config.get(self._section, name))
# initializing and reading in config file
config = Config()
config.section('reactor')
if config['reactor'] == 'thread':
checker = CheckerThread()
elif config['reactor'] == 'plain':
checker = Checker()
elif config['reactor'] == 'kqueue':
checker = CheckerKqueue()
checker.loop()