Add is_host_valid util (#76589)

homeassistant/components/braviatv/config_flow.py

@@ -1,9 +1,6 @@
 """Config flow to configure the Bravia TV integration."""
 from __future__ import annotations
 
-from contextlib import suppress
-import ipaddress
-import re
 from typing import Any
 
 from aiohttp import CookieJar
@@ -17,6 +14,7 @@ from homeassistant.core import callback
 from homeassistant.data_entry_flow import FlowResult
 from homeassistant.helpers.aiohttp_client import async_create_clientsession
 import homeassistant.helpers.config_validation as cv
+from homeassistant.util.network import is_host_valid
 
 from . import BraviaTVCoordinator
 from .const import (
@@ -30,15 +28,6 @@ from .const import (
 )
 
 
-def host_valid(host: str) -> bool:
-    """Return True if hostname or IP address is valid."""
-    with suppress(ValueError):
-        if ipaddress.ip_address(host).version in [4, 6]:
-            return True
-    disallowed = re.compile(r"[^a-zA-Z\d\-]")
-    return all(x and not disallowed.search(x) for x in host.split("."))
-
-
 class BraviaTVConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
     """Handle a config flow for Bravia TV integration."""
 
@@ -82,7 +71,7 @@ class BraviaTVConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
 
         if user_input is not None:
             host = user_input[CONF_HOST]
-            if host_valid(host):
+            if is_host_valid(host):
                 session = async_create_clientsession(
                     self.hass,
                     cookie_jar=CookieJar(unsafe=True, quote_cookie=False),

homeassistant/components/brother/config_flow.py

@@ -1,8 +1,6 @@
 """Adds config flow for Brother Printer."""
 from __future__ import annotations
 
-import ipaddress
-import re
 from typing import Any
 
 from brother import Brother, SnmpError, UnsupportedModel
@@ -12,6 +10,7 @@ from homeassistant import config_entries, exceptions
 from homeassistant.components import zeroconf
 from homeassistant.const import CONF_HOST, CONF_TYPE
 from homeassistant.data_entry_flow import FlowResult
+from homeassistant.util.network import is_host_valid
 
 from .const import DOMAIN, PRINTER_TYPES
 from .utils import get_snmp_engine
@@ -24,17 +23,6 @@ DATA_SCHEMA = vol.Schema(
 )
 
 
-def host_valid(host: str) -> bool:
-    """Return True if hostname or IP address is valid."""
-    try:
-        if ipaddress.ip_address(host).version in [4, 6]:
-            return True
-    except ValueError:
-        pass
-    disallowed = re.compile(r"[^a-zA-Z\d\-]")
-    return all(x and not disallowed.search(x) for x in host.split("."))
-
-
 class BrotherConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
     """Handle a config flow for Brother Printer."""
 
@@ -53,7 +41,7 @@ class BrotherConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
 
         if user_input is not None:
             try:
-                if not host_valid(user_input[CONF_HOST]):
+                if not is_host_valid(user_input[CONF_HOST]):
                     raise InvalidHost()
 
                 snmp_engine = get_snmp_engine(self.hass)

homeassistant/components/dunehd/config_flow.py

@@ -1,8 +1,6 @@
 """Adds config flow for Dune HD integration."""
 from __future__ import annotations
 
-import ipaddress
-import re
 from typing import Any
 
 from pdunehd import DuneHDPlayer
@@ -11,23 +9,11 @@ import voluptuous as vol
 from homeassistant import config_entries, exceptions
 from homeassistant.const import CONF_HOST
 from homeassistant.data_entry_flow import FlowResult
+from homeassistant.util.network import is_host_valid
 
 from .const import DOMAIN
 
 
-def host_valid(host: str) -> bool:
-    """Return True if hostname or IP address is valid."""
-    try:
-        if ipaddress.ip_address(host).version in (4, 6):
-            return True
-    except ValueError:
-        pass
-    if len(host) > 253:
-        return False
-    allowed = re.compile(r"(?!-)[A-Z\d\-\_]{1,63}(?<!-)$", re.IGNORECASE)
-    return all(allowed.match(x) for x in host.split("."))
-
-
 class DuneHDConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
     """Handle a config flow for Dune HD integration."""
 
@@ -47,7 +33,7 @@ class DuneHDConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
         errors = {}
 
         if user_input is not None:
-            if host_valid(user_input[CONF_HOST]):
+            if is_host_valid(user_input[CONF_HOST]):
                 host: str = user_input[CONF_HOST]
 
                 try:

homeassistant/components/vilfo/config_flow.py

@@ -1,7 +1,5 @@
 """Config flow for Vilfo Router integration."""
-import ipaddress
 import logging
-import re
 
 from vilfo import Client as VilfoClient
 from vilfo.exceptions import (
@@ -12,6 +10,7 @@ import voluptuous as vol
 
 from homeassistant import config_entries, core, exceptions
 from homeassistant.const import CONF_ACCESS_TOKEN, CONF_HOST, CONF_ID, CONF_MAC
+from homeassistant.util.network import is_host_valid
 
 from .const import DOMAIN, ROUTER_DEFAULT_HOST
 
@@ -29,16 +28,6 @@ RESULT_CANNOT_CONNECT = "cannot_connect"
 RESULT_INVALID_AUTH = "invalid_auth"
 
 
-def host_valid(host):
-    """Return True if hostname or IP address is valid."""
-    try:
-        if ipaddress.ip_address(host).version in (4, 6):
-            return True
-    except ValueError:
-        disallowed = re.compile(r"[^a-zA-Z\d\-]")
-        return all(x and not disallowed.search(x) for x in host.split("."))
-
-
 def _try_connect_and_fetch_basic_info(host, token):
     """Attempt to connect and call the ping endpoint and, if successful, fetch basic information."""
 
@@ -80,7 +69,7 @@ async def validate_input(hass: core.HomeAssistant, data):
     """
 
     # Validate the host before doing anything else.
-    if not host_valid(data[CONF_HOST]):
+    if not is_host_valid(data[CONF_HOST]):
         raise InvalidHost
 
     config = {}

homeassistant/util/network.py

@@ -2,6 +2,7 @@
 from __future__ import annotations
 
 from ipaddress import IPv4Address, IPv6Address, ip_address, ip_network
+import re
 
 import yarl
 
@@ -86,6 +87,20 @@ def is_ipv6_address(address: str) -> bool:
     return True
 
 
+def is_host_valid(host: str) -> bool:
+    """Check if a given string is an IP address or valid hostname."""
+    if is_ip_address(host):
+        return True
+    if len(host) > 255:
+        return False
+    if re.match(r"^[0-9\.]+$", host):  # reject invalid IPv4
+        return False
+    if host.endswith("."):  # dot at the end is correct
+        host = host[:-1]
+    allowed = re.compile(r"(?!-)[A-Z\d\-]{1,63}(?<!-)$", re.IGNORECASE)
+    return all(allowed.match(x) for x in host.split("."))
+
+
 def normalize_url(address: str) -> str:
     """Normalize a given URL."""
     url = yarl.URL(address.rstrip("/"))

tests/util/test_network.py

@@ -80,6 +80,30 @@ def test_is_ipv6_address():
     assert network_util.is_ipv6_address("8.8.8.8") is False
 
 
+def test_is_valid_host():
+    """Test if strings are IPv6 addresses."""
+    assert network_util.is_host_valid("::1")
+    assert network_util.is_host_valid("::ffff:127.0.0.0")
+    assert network_util.is_host_valid("2001:0db8:85a3:0000:0000:8a2e:0370:7334")
+    assert network_util.is_host_valid("8.8.8.8")
+    assert network_util.is_host_valid("local")
+    assert network_util.is_host_valid("host-host")
+    assert network_util.is_host_valid("example.com")
+    assert network_util.is_host_valid("example.com.")
+    assert network_util.is_host_valid("Example123.com")
+    assert not network_util.is_host_valid("")
+    assert not network_util.is_host_valid("192.168.0.1:8080")
+    assert not network_util.is_host_valid("192.168.0.999")
+    assert not network_util.is_host_valid("2001:hb8::1:0:0:1")
+    assert not network_util.is_host_valid("-host-host")
+    assert not network_util.is_host_valid("host-host-")
+    assert not network_util.is_host_valid("host_host")
+    assert not network_util.is_host_valid("example.com/path")
+    assert not network_util.is_host_valid("example.com:8080")
+    assert not network_util.is_host_valid("verylonghostname" * 4)
+    assert not network_util.is_host_valid("verydeepdomain." * 18)
+
+
 def test_normalize_url():
     """Test the normalizing of URLs."""
     assert network_util.normalize_url("http://example.com") == "http://example.com"