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try:
try:
from berkeleydb import db
except:
from bsddb3 import db
class DB(object):
def open(self,fname,mode):
if mode == 'r': flags = db.DB_RDONLY
else: raise RuntimeException('unsupported mode')
self.f = db.DB()
self.f.open(fname,flags=flags)
def __contains__(self,key):
return not not self.f.get(key)
def __getitem__(self,key):
v = self.f.get(key)
if not v: raise KeyError(key)
return v
def close(self):
self.f.close()
def dbmopen(fname,mode):
f = DB()
f.open(fname,mode)
return f
except ModuleNotFoundError: raise
except:
import anydbm as dbm
dbmopen = dbm.open
class MTAPolicy(object):
"Get SPF policy by result from sendmail style access file."
def __init__(self,sender,conf,access_file=None):
if not access_file:
access_file = conf.access_file
self.use_nulls = conf.access_file_nulls
try:
self.use_colon = conf.access_file_colon
except:
self.use_colon = True
self.sender = sender
self.domain = sender.split('@')[-1].lower()
self.acf = None
self.access_file = access_file
def close(self):
if self.acf:
self.acf.close()
def __enter__(self):
self.acf = None
if self.access_file:
try:
self.acf = dbmopen(self.access_file,'r')
except:
print('%s: Cannot open for reading'%self.access_file)
raise
return self
def __exit__(self,t,v,b): self.close()
def getPolicy(self,pfx):
acf = self.acf
if not acf: return None
if self.use_nulls: sfx = b'\x00'
else: sfx = b''
if self.use_colon:
sep = b':'
else:
sep = b'!'
pfx = pfx.encode() + sep
try: # try with localpart@domain
return acf[pfx + self.sender.encode() + sfx].rstrip(b'\x00').decode()
except KeyError:
try: # try with domain
d = self.domain.encode()
k = pfx + d + sfx
while not k in acf and b'.' in d:
# check partial domains
d = b'.'.join(d.split(b'.')[1:])
k = pfx + b'.' + d + sfx
return acf[k].rstrip(b'\x00').decode()
except KeyError:
try: # try bare prefix
return acf[pfx + sfx].rstrip(b'\x00').decode()
except KeyError:
try:
return acf[pfx[:-1] + sfx].rstrip(b'\x00').decode()
except KeyError:
return None
|
