Prefer ULA over GUA addresses [IPv6] (#1508)

* On installs with GUA and ULA's we should prefer ULA's as it's been demonstrated that GUA's can and often are rotated by ISPs. Fixes #1473

* Add test for link-local address detection

* Add ULA-only and GUA-only tests

* Add test_IPv6_GUA_ULA_test and test_IPv6_ULA_GUA_test

* Add ""

* Add mock_command_2 command that can mock a command with more than one argument (as "ip -6 address") and result multiple lines of results

* Make mock_command_2 more similar to the original mock_command

* Correct comments

* Fixed remaining comments

* Fixed one last comment...

* Fixed a comment...

test/test_automated_install.py

@@ -402,6 +402,61 @@ def test_FTL_binary_installed_and_responsive_no_errors(Pihole):
 #     assert '644 /run/pihole-FTL.pid' in support_files.stdout
 #     assert '644 /var/log/pihole-FTL.log' in support_files.stdout
 
+def test_IPv6_only_link_local(Pihole):
+    ''' confirms IPv6 blocking is disabled for Link-local address '''
+    # mock ip -6 address to return Link-local address
+    mock_command_2('ip', {'-6 address':('inet6 fe80::d210:52fa:fe00:7ad7/64 scope link', '0')}, Pihole)
+    detectPlatform = Pihole.run('''
+    source /opt/pihole/basic-install.sh
+    useIPv6dialog
+    ''')
+    expected_stdout = 'Found neither IPv6 ULA nor GUA address, blocking IPv6 ads will not be enabled'
+    assert expected_stdout in detectPlatform.stdout
+
+def test_IPv6_only_ULA(Pihole):
+    ''' confirms IPv6 blocking is enabled for ULA addresses '''
+    # mock ip -6 address to return ULA address
+    mock_command_2('ip', {'-6 address':('inet6 fda2:2001:5555:0:d210:52fa:fe00:7ad7/64 scope global', '0')}, Pihole)
+    detectPlatform = Pihole.run('''
+    source /opt/pihole/basic-install.sh
+    useIPv6dialog
+    ''')
+    expected_stdout = 'Found IPv6 ULA address, using it for blocking IPv6 ads'
+    assert expected_stdout in detectPlatform.stdout
+
+def test_IPv6_only_GUA(Pihole):
+    ''' confirms IPv6 blocking is enabled for GUA addresses '''
+    # mock ip -6 address to return GUA address
+    mock_command_2('ip', {'-6 address':('inet6 2003:12:1e43:301:d210:52fa:fe00:7ad7/64 scope global', '0')}, Pihole)
+    detectPlatform = Pihole.run('''
+    source /opt/pihole/basic-install.sh
+    useIPv6dialog
+    ''')
+    expected_stdout = 'Found IPv6 GUA address, using it for blocking IPv6 ads'
+    assert expected_stdout in detectPlatform.stdout
+
+def test_IPv6_GUA_ULA_test(Pihole):
+    ''' confirms IPv6 blocking is enabled for GUA and ULA addresses '''
+    # mock ip -6 address to return GUA and ULA addresses
+    mock_command_2('ip', {'-6 address':('inet6 2003:12:1e43:301:d210:52fa:fe00:7ad7/64 scope global\ninet6 fda2:2001:5555:0:d210:52fa:fe00:7ad7/64 scope global', '0')}, Pihole)
+    detectPlatform = Pihole.run('''
+    source /opt/pihole/basic-install.sh
+    useIPv6dialog
+    ''')
+    expected_stdout = 'Found IPv6 ULA address, using it for blocking IPv6 ads'
+    assert expected_stdout in detectPlatform.stdout
+
+def test_IPv6_ULA_GUA_test(Pihole):
+    ''' confirms IPv6 blocking is enabled for GUA and ULA addresses '''
+    # mock ip -6 address to return ULA and GUA addresses
+    mock_command_2('ip', {'-6 address':('inet6 fda2:2001:5555:0:d210:52fa:fe00:7ad7/64 scope global\ninet6 2003:12:1e43:301:d210:52fa:fe00:7ad7/64 scope global', '0')}, Pihole)
+    detectPlatform = Pihole.run('''
+    source /opt/pihole/basic-install.sh
+    useIPv6dialog
+    ''')
+    expected_stdout = 'Found IPv6 ULA address, using it for blocking IPv6 ads'
+    assert expected_stdout in detectPlatform.stdout
+
 # Helper functions
 def mock_command(script, args, container):
     ''' Allows for setup of commands we don't really want to have to run for real in unit tests '''
@@ -424,6 +479,27 @@ def mock_command(script, args, container):
     chmod +x {script}
     rm -f /var/log/{scriptlog}'''.format(script=full_script_path, content=mock_script, scriptlog=script))
 
+def mock_command_2(script, args, container):
+    ''' Allows for setup of commands we don't really want to have to run for real in unit tests '''
+    full_script_path = '/usr/local/bin/{}'.format(script)
+    mock_script = dedent('''\
+    #!/bin/bash -e
+    echo "\$0 \$@" >> /var/log/{script}
+    case "\$1 \$2" in'''.format(script=script))
+    for k, v in args.iteritems():
+        case = dedent('''
+        \"{arg}\")
+        echo \"{res}\"
+        exit {retcode}
+        ;;'''.format(arg=k, res=v[0], retcode=v[1]))
+        mock_script += case
+    mock_script += dedent('''
+    esac''')
+    container.run('''
+    cat <<EOF> {script}\n{content}\nEOF
+    chmod +x {script}
+    rm -f /var/log/{scriptlog}'''.format(script=full_script_path, content=mock_script, scriptlog=script))
+
 def run_script(Pihole, script):
     result = Pihole.run(script)
     assert result.rc == 0