Moved sshuttle/tests into tests to.

Having the tests in a `tests` directory in root is the most common
approach. Also moved pytest's conftest.py into `tests` making the
fixture available for client and server tests.

tests/client/test_methods_nat.py

@@ -0,0 +1,162 @@
+import pytest
+from mock import Mock, patch, call
+import socket
+from socket import AF_INET, AF_INET6
+import struct
+
+from sshuttle.helpers import Fatal
+from sshuttle.methods import get_method
+
+
+def test_get_supported_features():
+    method = get_method('nat')
+    features = method.get_supported_features()
+    assert not features.ipv6
+    assert not features.udp
+    assert features.dns
+
+
+def test_get_tcp_dstip():
+    sock = Mock()
+    sock.getsockopt.return_value = struct.pack(
+        '!HHBBBB', socket.ntohs(AF_INET), 1024, 127, 0, 0, 1)
+    method = get_method('nat')
+    assert method.get_tcp_dstip(sock) == ('127.0.0.1', 1024)
+    assert sock.mock_calls == [call.getsockopt(0, 80, 16)]
+
+
+def test_recv_udp():
+    sock = Mock()
+    sock.recvfrom.return_value = "11111", "127.0.0.1"
+    method = get_method('nat')
+    result = method.recv_udp(sock, 1024)
+    assert sock.mock_calls == [call.recvfrom(1024)]
+    assert result == ("127.0.0.1", None, "11111")
+
+
+def test_send_udp():
+    sock = Mock()
+    method = get_method('nat')
+    method.send_udp(sock, None, "127.0.0.1", "22222")
+    assert sock.mock_calls == [call.sendto("22222", "127.0.0.1")]
+
+
+def test_setup_tcp_listener():
+    listener = Mock()
+    method = get_method('nat')
+    method.setup_tcp_listener(listener)
+    assert listener.mock_calls == []
+
+
+def test_setup_udp_listener():
+    listener = Mock()
+    method = get_method('nat')
+    method.setup_udp_listener(listener)
+    assert listener.mock_calls == []
+
+
+def test_assert_features():
+    method = get_method('nat')
+    features = method.get_supported_features()
+    method.assert_features(features)
+
+    features.udp = True
+    with pytest.raises(Fatal):
+        method.assert_features(features)
+
+    features.ipv6 = True
+    with pytest.raises(Fatal):
+        method.assert_features(features)
+
+
+def test_firewall_command():
+    method = get_method('nat')
+    assert not method.firewall_command("somthing")
+
+
+@patch('sshuttle.methods.nat.ipt')
+@patch('sshuttle.methods.nat.ipt_ttl')
+@patch('sshuttle.methods.nat.ipt_chain_exists')
+def test_setup_firewall(mock_ipt_chain_exists, mock_ipt_ttl, mock_ipt):
+    mock_ipt_chain_exists.return_value = True
+    method = get_method('nat')
+    assert method.name == 'nat'
+
+    with pytest.raises(Exception) as excinfo:
+        method.setup_firewall(
+            1024, 1026,
+            [(AF_INET6, u'2404:6800:4004:80c::33')],
+            AF_INET6,
+            [(AF_INET6, 64, False, u'2404:6800:4004:80c::', 0, 0),
+                (AF_INET6, 128, True, u'2404:6800:4004:80c::101f', 80, 80)],
+            True,
+            None)
+    assert str(excinfo.value) \
+        == 'Address family "AF_INET6" unsupported by nat method_name'
+    assert mock_ipt_chain_exists.mock_calls == []
+    assert mock_ipt_ttl.mock_calls == []
+    assert mock_ipt.mock_calls == []
+
+    with pytest.raises(Exception) as excinfo:
+        method.setup_firewall(
+            1025, 1027,
+            [(AF_INET, u'1.2.3.33')],
+            AF_INET,
+            [(AF_INET, 24, False, u'1.2.3.0', 8000, 9000),
+                (AF_INET, 32, True, u'1.2.3.66', 8080, 8080)],
+            True,
+            None)
+    assert str(excinfo.value) == 'UDP not supported by nat method_name'
+    assert mock_ipt_chain_exists.mock_calls == []
+    assert mock_ipt_ttl.mock_calls == []
+    assert mock_ipt.mock_calls == []
+
+    method.setup_firewall(
+        1025, 1027,
+        [(AF_INET, u'1.2.3.33')],
+        AF_INET,
+        [(AF_INET, 24, False, u'1.2.3.0', 8000, 9000),
+            (AF_INET, 32, True, u'1.2.3.66', 8080, 8080)],
+        False,
+        None)
+    assert mock_ipt_chain_exists.mock_calls == [
+        call(AF_INET, 'nat', 'sshuttle-1025')
+    ]
+    assert mock_ipt_ttl.mock_calls == [
+        call(AF_INET, 'nat', '-A', 'sshuttle-1025', '-j', 'REDIRECT',
+            '--dest', u'1.2.3.0/24', '-p', 'tcp', '--dport', '8000:9000',
+             '--to-ports', '1025'),
+        call(AF_INET, 'nat', '-A', 'sshuttle-1025', '-j', 'REDIRECT',
+             '--dest', u'1.2.3.33/32', '-p', 'udp',
+             '--dport', '53', '--to-ports', '1027')
+    ]
+    assert mock_ipt.mock_calls == [
+        call(AF_INET, 'nat', '-D', 'OUTPUT', '-j', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-D', 'PREROUTING', '-j', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-F', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-X', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-N', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-F', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-I', 'OUTPUT', '1', '-j', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-I', 'PREROUTING', '1', '-j', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-A', 'sshuttle-1025', '-j', 'RETURN',
+            '--dest', u'1.2.3.66/32', '-p', 'tcp', '--dport', '8080:8080')
+    ]
+    mock_ipt_chain_exists.reset_mock()
+    mock_ipt_ttl.reset_mock()
+    mock_ipt.reset_mock()
+
+    method.restore_firewall(1025, AF_INET, False, None)
+    assert mock_ipt_chain_exists.mock_calls == [
+        call(AF_INET, 'nat', 'sshuttle-1025')
+    ]
+    assert mock_ipt_ttl.mock_calls == []
+    assert mock_ipt.mock_calls == [
+        call(AF_INET, 'nat', '-D', 'OUTPUT', '-j', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-D', 'PREROUTING', '-j', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-F', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-X', 'sshuttle-1025')
+    ]
+    mock_ipt_chain_exists.reset_mock()
+    mock_ipt_ttl.reset_mock()
+    mock_ipt.reset_mock()