Expand network util to check for link local addresses (#33499)

Author: bdraco

homeassistant/components/axis/config_flow.py

@@ -1,5 +1,7 @@
 """Config flow to configure Axis devices."""
 
+from ipaddress import ip_address
+
 import voluptuous as vol
 
 from homeassistant import config_entries
@@ -11,6 +13,7 @@
     CONF_PORT,
     CONF_USERNAME,
 )
+from homeassistant.util.network import is_link_local
 
 from .const import CONF_MODEL, DOMAIN
 from .device import get_device
@@ -129,7 +132,7 @@ async def async_step_zeroconf(self, discovery_info):
         if serial_number[:6] not in AXIS_OUI:
             return self.async_abort(reason="not_axis_device")
 
-        if discovery_info[CONF_HOST].startswith("169.254"):
+        if is_link_local(ip_address(discovery_info[CONF_HOST])):
             return self.async_abort(reason="link_local_address")
 
         await self.async_set_unique_id(serial_number)

homeassistant/components/doorbird/config_flow.py

@@ -1,4 +1,5 @@
 """Config flow for DoorBird integration."""
+from ipaddress import ip_address
 import logging
 import urllib
 
@@ -8,6 +9,7 @@
 from homeassistant import config_entries, core, exceptions
 from homeassistant.const import CONF_HOST, CONF_NAME, CONF_PASSWORD, CONF_USERNAME
 from homeassistant.core import callback
+from homeassistant.util.network import is_link_local
 
 from .const import CONF_EVENTS, DOORBIRD_OUI
 from .const import DOMAIN  # pylint:disable=unused-import
@@ -90,7 +92,7 @@ async def async_step_zeroconf(self, discovery_info):
 
         if macaddress[:6] != DOORBIRD_OUI:
             return self.async_abort(reason="not_doorbird_device")
-        if discovery_info[CONF_HOST].startswith("169.254"):
+        if is_link_local(ip_address(discovery_info[CONF_HOST])):
             return self.async_abort(reason="link_local_address")
 
         await self.async_set_unique_id(macaddress)

homeassistant/util/network.py

@@ -1,18 +1,41 @@
 """Network utilities."""
-from ipaddress import IPv4Address, IPv6Address, ip_address, ip_network
+from ipaddress import IPv4Address, IPv6Address, ip_network
 from typing import Union
 
-# IP addresses of loopback interfaces
-LOCAL_IPS = (ip_address("127.0.0.1"), ip_address("::1"))
+# RFC6890 - IP addresses of loopback interfaces
+LOOPBACK_NETWORKS = (
+    ip_network("127.0.0.0/8"),
+    ip_network("::1/128"),
+    ip_network("::ffff:127.0.0.0/104"),
+)
 
-# RFC1918 - Address allocation for Private Internets
-LOCAL_NETWORKS = (
+# RFC6890 - Address allocation for Private Internets
+PRIVATE_NETWORKS = (
+    ip_network("fd00::/8"),
     ip_network("10.0.0.0/8"),
     ip_network("172.16.0.0/12"),
     ip_network("192.168.0.0/16"),
 )
 
+# RFC6890 - Link local ranges
+LINK_LOCAL_NETWORK = ip_network("169.254.0.0/16")
+
+
+def is_loopback(address: Union[IPv4Address, IPv6Address]) -> bool:
+    """Check if an address is a loopback address."""
+    return any(address in network for network in LOOPBACK_NETWORKS)
+
+
+def is_private(address: Union[IPv4Address, IPv6Address]) -> bool:
+    """Check if an address is a private address."""
+    return any(address in network for network in PRIVATE_NETWORKS)
+
+
+def is_link_local(address: Union[IPv4Address, IPv6Address]) -> bool:
+    """Check if an address is link local."""
+    return address in LINK_LOCAL_NETWORK
+
 
 def is_local(address: Union[IPv4Address, IPv6Address]) -> bool:
-    """Check if an address is local."""
-    return address in LOCAL_IPS or any(address in network for network in LOCAL_NETWORKS)
+    """Check if an address is loopback or private."""
+    return is_loopback(address) or is_private(address)

tests/util/test_network.py

@@ -0,0 +1,40 @@
+"""Test Home Assistant volume utility functions."""
+
+from ipaddress import ip_address
+
+import homeassistant.util.network as network_util
+
+
+def test_is_loopback():
+    """Test loopback addresses."""
+    assert network_util.is_loopback(ip_address("127.0.0.2"))
+    assert network_util.is_loopback(ip_address("127.0.0.1"))
+    assert network_util.is_loopback(ip_address("::1"))
+    assert network_util.is_loopback(ip_address("::ffff:127.0.0.0"))
+    assert network_util.is_loopback(ip_address("0:0:0:0:0:0:0:1"))
+    assert network_util.is_loopback(ip_address("0:0:0:0:0:ffff:7f00:1"))
+    assert not network_util.is_loopback(ip_address("104.26.5.238"))
+    assert not network_util.is_loopback(ip_address("2600:1404:400:1a4::356e"))
+
+
+def test_is_private():
+    """Test private addresses."""
+    assert network_util.is_private(ip_address("192.168.0.1"))
+    assert network_util.is_private(ip_address("172.16.12.0"))
+    assert network_util.is_private(ip_address("10.5.43.3"))
+    assert network_util.is_private(ip_address("fd12:3456:789a:1::1"))
+    assert not network_util.is_private(ip_address("127.0.0.1"))
+    assert not network_util.is_private(ip_address("::1"))
+
+
+def test_is_link_local():
+    """Test link local addresses."""
+    assert network_util.is_link_local(ip_address("169.254.12.3"))
+    assert not network_util.is_link_local(ip_address("127.0.0.1"))
+
+
+def test_is_local():
+    """Test local addresses."""
+    assert network_util.is_local(ip_address("192.168.0.1"))
+    assert network_util.is_local(ip_address("127.0.0.1"))
+    assert not network_util.is_local(ip_address("208.5.4.2"))