Commit f714c4ca authored by JINMEI Tatuya's avatar JINMEI Tatuya
Browse files

[2911] more refactoring: unify xfr command handling into a single method.

parent 4acf3803
......@@ -1518,67 +1518,69 @@ class Xfrin:
continue
th.join()
def __handle_xfr_by_zonemgr(self, args):
# Xfrin receives the refresh/notify command from zone manager.
# notify command maybe has the parameters which
# specify the notifyfrom address and port, according to
# RFC1996, zone transfer should starts first from the
# notifyfrom, but this is a 'TODO' item for now.
# (using the value now, while we can only set one master
# address, would be a security hole. Once we add the ability
# to have multiple master addresses,
# we should check if it matches one of them, and then use it.)
(zone_name, rrclass) = self._parse_zone_name_and_class(args)
zone_str = format_zone_str(zone_name, rrclass)
zone_info = self._get_zone_info(zone_name, rrclass)
notify_addr = self._parse_master_and_port(args, zone_name, rrclass)
def __validate_notify_addr(self, notify_addr, zone_str, zone_info):
"""Validate notify source as a destination for xfr source.
This is called from __handle_xfr_command in case xfr is triggered
by ZoneMgr either due to incoming Notify or periodic refresh event.
"""
if zone_info is None:
# TODO what to do? no info known about zone. defaults?
errmsg = "Got notification to retransfer unknown zone " + zone_str
logger.info(XFRIN_RETRANSFER_UNKNOWN_ZONE, zone_str)
answer = create_answer(1, errmsg)
return create_answer(1, errmsg)
else:
request_type = RRType.AXFR
if zone_info.use_ixfr:
request_type = RRType.IXFR
master_addr = zone_info.get_master_addr_info()
if (notify_addr[0] == master_addr[0] and
notify_addr[2] == master_addr[2]):
ret = self.xfrin_start(zone_name, rrclass, self._get_db_file(),
master_addr, zone_info.get_tsig_key(),
request_type, True)
answer = create_answer(ret[0], ret[1])
else:
if (notify_addr[0] != master_addr[0] or
notify_addr[2] != master_addr[2]):
notify_addr_str = format_addrinfo(notify_addr)
master_addr_str = format_addrinfo(master_addr)
errmsg = "Got notification for " + zone_str\
+ "from unknown address: " + notify_addr_str;
logger.info(XFRIN_NOTIFY_UNKNOWN_MASTER, zone_str,
notify_addr_str, master_addr_str)
answer = create_answer(1, errmsg)
return answer
return create_answer(1, errmsg)
# Notified address is okay
return None
def __handle_xfr_by_user(self, command, args):
# Xfrin receives the retransfer/refresh from cmdctl(sent by
# bindctl). If the command has specified master address, do
# transfer from the master address, or else do transfer from
# the configured masters.
def __handle_xfr_command(self, args, arg_db, check_soa, addr_validator):
"""Common subroutine for handling transfer commands.
This helper method unifies both cases of transfer command from
ZoneMgr or from a user. Depending on who invokes the transfer,
details of validation and parameter selection slightly vary.
These conditions are passed through parameters and handled in the
unified code of this method accordingly.
If this is from the ZoneMgr due to incoming notify, zone transfer
should start from the notify's source address as long as it's
configured as a master address, according to RFC1996. The current
implementation conforms to it in a limited way: we can only set one
master address. Once we add the ability to have multiple master
addresses, we should check if it matches one of them, and then use it.
In case of transfer command from the user, if the command specifies
the master address, use that one; otherwise try to use a configured
master address for the zone.
"""
(zone_name, rrclass) = self._parse_zone_name_and_class(args)
master_addr = self._parse_master_and_port(args, zone_name, rrclass)
zone_info = self._get_zone_info(zone_name, rrclass)
tsig_key = None
request_type = RRType.AXFR
if zone_info:
tsig_key = zone_info.get_tsig_key()
if zone_info.use_ixfr:
request_type = RRType.IXFR
db_file = args.get('db_file') or self._get_db_file()
if zone_info is not None and zone_info.use_ixfr:
request_type = RRType.IXFR
tsig_key = None if zone_info is None else zone_info.get_tsig_key()
db_file = arg_db or self._get_db_file()
zone_str = format_zone_str(zone_name, rrclass) # for logging
answer = addr_validator(master_addr, zone_str, zone_info)
if answer is not None:
return answer
ret = self.xfrin_start(zone_name, rrclass, db_file, master_addr,
tsig_key, request_type,
(False if command == 'retransfer' else True))
answer = create_answer(ret[0], ret[1])
return answer
tsig_key, request_type, check_soa)
return create_answer(ret[0], ret[1])
def command_handler(self, command, args):
logger.debug(DBG_XFRIN_TRACE, XFRIN_RECEIVED_COMMAND, command)
......@@ -1587,9 +1589,22 @@ class Xfrin:
if command == 'shutdown':
self._shutdown_event.set()
elif command == 'notify' or command == REFRESH_FROM_ZONEMGR:
answer = self.__handle_xfr_by_zonemgr(args)
# refresh/notify command from zone manager.
# The address has to be validated, db_file is local only,
# and always perform SOA check.
addr_validator = \
lambda x, y, z: self.__validate_notify_addr(x, y, z)
answer = self.__handle_xfr_command(args, None, True,
addr_validator)
elif command == 'retransfer' or command == 'refresh':
answer = self.__handle_xfr_by_user(command, args)
# retransfer/refresh from cmdctl (sent by bindctl).
# No need for address validation, db_file may be specified
# with the command, and whether to do SOA check depends on
# type of command.
check_soa = False if command == 'retransfer' else True
answer = self.__handle_xfr_command(args, args.get('db_file'),
check_soa,
lambda x, y, z: None)
# return statistics data to the stats daemon
elif command == "getstats":
# The log level is here set to debug in order to avoid
......@@ -1610,7 +1625,8 @@ class Xfrin:
if zone_name_str is None:
raise XfrinException('zone name should be provided')
return (_check_zone_name(zone_name_str), _check_zone_class(args.get('zone_class')))
return (_check_zone_name(zone_name_str),
_check_zone_class(args.get('zone_class')))
def _parse_master_and_port(self, args, zone_name, zone_class):
"""
......
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