Merge branch '0.10' into 0.11

fail2ban/server/ipdns.py

@@ -42,6 +42,32 @@ def asip(ip):
 		return ip
 	return IPAddr(ip)
 
+def getfqdn(name=''):
+	"""Get fully-qualified hostname of given host, thereby resolve of an external
+	IPs and name will be preferred before the local domain (or a loopback), see gh-2438
+	"""
+	try:
+		name = name or socket.gethostname()
+		names = (
+			ai[3] for ai in socket.getaddrinfo(
+				name, None, 0, socket.SOCK_DGRAM, 0, socket.AI_CANONNAME
+			) if ai[3]
+		)
+		if names:
+			# first try to find a fqdn starting with the host name like www.domain.tld for www:
+			pref = name+'.'
+			first = None
+			for ai in names:
+				if ai.startswith(pref):
+					return ai
+				if not first: first = ai
+			# not found - simply use first known fqdn:
+			return first
+	except socket.error:
+		pass
+	# fallback to python's own getfqdn routine:
+	return socket.getfqdn(name)
+
 
 ##
 # Utils class for DNS handling.
@@ -132,7 +158,7 @@ class DNSUtils:
 		if name is None:
 			name = ''
 			for hostname in (
-				(socket.getfqdn, socket.gethostname) if fqdn else (socket.gethostname, socket.getfqdn)
+				(getfqdn, socket.gethostname) if fqdn else (socket.gethostname, getfqdn)
 			):
 				try:
 					name = hostname()

fail2ban/tests/filtertestcase.py

@@ -40,7 +40,7 @@ from ..server.jail import Jail
 from ..server.filterpoll import FilterPoll
 from ..server.filter import FailTicket, Filter, FileFilter, FileContainer
 from ..server.failmanager import FailManagerEmpty
-from ..server.ipdns import DNSUtils, IPAddr
+from ..server.ipdns import getfqdn, DNSUtils, IPAddr
 from ..server.mytime import MyTime
 from ..server.utils import Utils, uni_decode
 from .utils import setUpMyTime, tearDownMyTime, mtimesleep, with_tmpdir, LogCaptureTestCase, \
@@ -2028,6 +2028,20 @@ class DNSUtilsNetworkTests(unittest.TestCase):
 		ip1 = IPAddr('93.184.216.34'); ip2 = IPAddr('93.184.216.34'); self.assertEqual(id(ip1), id(ip2))
 		ip1 = IPAddr('2606:2800:220:1:248:1893:25c8:1946'); ip2 = IPAddr('2606:2800:220:1:248:1893:25c8:1946'); self.assertEqual(id(ip1), id(ip2))
 
+	def testFQDN(self):
+		sname = DNSUtils.getHostname(fqdn=False)
+		lname = DNSUtils.getHostname(fqdn=True)
+		# FQDN is not localhost if short hostname is not localhost too (or vice versa):
+		self.assertEqual(lname != 'localhost',
+		                 sname != 'localhost')
+		# FQDN from short name should be long name:
+		self.assertEqual(getfqdn(sname), lname)
+		# FQDN from FQDN is the same:
+		self.assertEqual(getfqdn(lname), lname)
+		# coverage (targeting all branches): FQDN from loopback and DNS blackhole is always the same:
+		self.assertIn(getfqdn('localhost.'), ('localhost', 'localhost.'))
+		self.assertIn(getfqdn('as112.arpa.'), ('as112.arpa.', 'as112.arpa'))
+
 
 class JailTests(unittest.TestCase):