## $Id: nnrpd_access.py 10282 2018-05-14 12:42:14Z iulius $ ## ## This is a sample access module for the Python nnrpd hook. ## ## See the INN Python Filtering and Authentication Hooks documentation ## for more information. ## The python_access: parameter in readers.conf is used to load this script. ## ## An instance of ACCESS class is passed to nnrpd via the set_auth_hook() ## function imported from nnrpd. The following methods of that class ## are known to nnrpd: ## ## __init__() - Use this method to initialize your ## general variables or open a common ## database connection. May be omitted. ## access_init() - Init function specific to access ## control. May be omitted. ## access(attributes) - Called when a python_access ## statement is reached in the ## processing of readers.conf. Returns ## a dictionary of values representing ## statements to be included in an ## access group. ## access_close() - Called on nnrpd termination. Save ## your state variables or close a ## database connection. May be omitted. ## ## If there is a problem with return codes from any of these methods, ## then nnrpd will die and syslog the exact reason. ## ## There are also a few Python functions defined in nnrpd: ## ## set_auth_hook() - Called by nnrpd as this module is loaded. ## It is used to pass a reference to an ## instance of authentication class to nnrpd. ## syslog() - An equivalent replacement for regular syslog. ## One consideration for using it is to ## uniform nnrpd logging. ## Sample access class. It defines all access methods known to nnrpd. class ACCESS: """Provide access callbacks to nnrpd.""" def __init__(self): """This is a good place to initialize variables or open a database connection.""" syslog('notice', 'nnrpd access class instance created') def access_init(self): """Called when this script is initialized.""" pass def access(self, attributes): """Called when python_access: is encountered in readers.conf.""" # Just for debugging purposes (in Python 3.x syntax). # syslog('notice', 'n_a access() invoked: hostname %s, ipaddress %s, port %lu, interface %s, intipaddr %s, intport %lu, user %s' % ( \ # attributes['hostname'].tobytes(), \ # attributes['ipaddress'].tobytes(), \ # attributes['port'], \ # attributes['interface'].tobytes(), \ # attributes['intipaddr'].tobytes(), \ # attributes['intport'], \ # (attributes['user'].tobytes() if attributes['user'] else "-"))) # Allow newsreading from specific host only. # Python 2.x syntax: # if '127.0.0.1' == str(attributes['ipaddress']): # Python 3.x syntax: # if b'127.0.0.1' == attributes['ipaddress'].tobytes(): # syslog('notice', 'authentication access by IP address succeeded') # return {'read':'*', 'post':'*'} syslog('notice', 'authentication access by IP address failed') return {'read':'!*', 'post':'!*'} def access_close(self): """Called on nnrpd termination.""" pass ## The rest is used to hook up the access module on nnrpd. It is unlikely ## you will ever need to modify this. ## Import functions exposed by nnrpd. This import must succeed, or nothing ## will work! from nnrpd import * ## Create a class instance. myaccess = ACCESS() ## ...and try to hook up on nnrpd. This would make auth object methods visible ## to nnrpd. import sys try: set_auth_hook(myaccess) syslog('notice', "access module successfully hooked into nnrpd") except Exception: # Syntax valid in both Python 2.x and 3.x. e = sys.exc_info()[1] syslog('error', "Cannot obtain nnrpd hook for access method: %s" % e.args[0])