tests: Make proxy_test work on travis servers without IPv6

Github-Pull: #7489
Rebased-From: 7539f1aae3b41279dc5d49e09f448a78a071e114
Cherry-picked-From: 9ca957bcd4

qa/rpc-tests/proxy_test.py

@@ -7,6 +7,7 @@ import socket
 from test_framework.socks5 import Socks5Configuration, Socks5Command, Socks5Server, AddressType
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import *
+from test_framework.netutil import test_ipv6_local
 '''
 Test plan:
 - Start bitcoind's with different proxy configurations
@@ -34,6 +35,7 @@ addnode connect to generic DNS name
 
 class ProxyTest(BitcoinTestFramework):
     def __init__(self):
+        self.have_ipv6 = test_ipv6_local()
         # Create two proxies on different ports
         # ... one unauthenticated
         self.conf1 = Socks5Configuration()
@@ -45,29 +47,36 @@ class ProxyTest(BitcoinTestFramework):
         self.conf2.addr = ('127.0.0.1', 14000 + (os.getpid() % 1000))
         self.conf2.unauth = True
         self.conf2.auth = True
+        if self.have_ipv6:
             # ... one on IPv6 with similar configuration
             self.conf3 = Socks5Configuration()
             self.conf3.af = socket.AF_INET6
             self.conf3.addr = ('::1', 15000 + (os.getpid() % 1000))
             self.conf3.unauth = True
             self.conf3.auth = True
+        else:
+            print "Warning: testing without local IPv6 support"
 
         self.serv1 = Socks5Server(self.conf1)
         self.serv1.start()
         self.serv2 = Socks5Server(self.conf2)
         self.serv2.start()
+        if self.have_ipv6:
             self.serv3 = Socks5Server(self.conf3)
             self.serv3.start()
 
     def setup_nodes(self):
         # Note: proxies are not used to connect to local nodes
         # this is because the proxy to use is based on CService.GetNetwork(), which return NET_UNROUTABLE for localhost
-        return start_nodes(4, self.options.tmpdir, extra_args=[
+        args = [
             ['-listen', '-debug=net', '-debug=proxy', '-proxy=%s:%i' % (self.conf1.addr),'-proxyrandomize=1'], 
             ['-listen', '-debug=net', '-debug=proxy', '-proxy=%s:%i' % (self.conf1.addr),'-onion=%s:%i' % (self.conf2.addr),'-proxyrandomize=0'], 
             ['-listen', '-debug=net', '-debug=proxy', '-proxy=%s:%i' % (self.conf2.addr),'-proxyrandomize=1'], 
-            ['-listen', '-debug=net', '-debug=proxy', '-proxy=[%s]:%i' % (self.conf3.addr),'-proxyrandomize=0', '-noonion']
+            []
-            ])
+            ]
+        if self.have_ipv6:
+            args[3] = ['-listen', '-debug=net', '-debug=proxy', '-proxy=[%s]:%i' % (self.conf3.addr),'-proxyrandomize=0', '-noonion']
+        return start_nodes(4, self.options.tmpdir, extra_args=args)
 
     def node_test(self, node, proxies, auth, test_onion=True):
         rv = []
@@ -84,6 +93,7 @@ class ProxyTest(BitcoinTestFramework):
             assert_equal(cmd.password, None)
         rv.append(cmd)
 
+        if self.have_ipv6:
             # Test: outgoing IPv6 connection through node
             node.addnode("[1233:3432:2434:2343:3234:2345:6546:4534]:5443", "onetry")
             cmd = proxies[1].queue.get()
@@ -135,8 +145,9 @@ class ProxyTest(BitcoinTestFramework):
         rv = self.node_test(self.nodes[2], [self.serv2, self.serv2, self.serv2, self.serv2], True)
         # Check that credentials as used for -proxyrandomize connections are unique
         credentials = set((x.username,x.password) for x in rv)
-        assert_equal(len(credentials), 4)
+        assert_equal(len(credentials), len(rv))
 
+        if self.have_ipv6:
             # proxy on IPv6 localhost
             self.node_test(self.nodes[3], [self.serv3, self.serv3, self.serv3, self.serv3], False, False)
 
@@ -167,6 +178,7 @@ class ProxyTest(BitcoinTestFramework):
             assert_equal(n2[net]['proxy_randomize_credentials'], True)
         assert_equal(n2['onion']['reachable'], True)
 
+        if self.have_ipv6:
             n3 = networks_dict(self.nodes[3].getnetworkinfo())
             for net in ['ipv4','ipv6']:
                 assert_equal(n3[net]['proxy'], '[%s]:%i' % (self.conf3.addr))

qa/rpc-tests/test_framework/netutil.py

@@ -137,3 +137,18 @@ def addr_to_hex(addr):
     else:
         raise ValueError('Could not parse address %s' % addr)
     return binascii.hexlify(bytearray(addr))
+
+def test_ipv6_local():
+    '''
+    Check for (local) IPv6 support.
+    '''
+    import socket
+    # By using SOCK_DGRAM this will not actually make a connection, but it will
+    # fail if there is no route to IPv6 localhost.
+    have_ipv6 = True
+    try:
+        s = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM)
+        s.connect(('::1', 0))
+    except socket.error:
+        have_ipv6 = False
+    return have_ipv6