From 4565b01eeb5624594e3e1e39ef5aa5b3cc779ea5 Mon Sep 17 00:00:00 2001
From: Pascal Vizeli <pvizeli@syshack.ch>
Date: Thu, 10 Sep 2020 23:51:31 +0200
Subject: [PATCH] Only support IPv4 for DNS (#2040)

---
 supervisor/validate.py |  6 +++++-
 tests/test_validate.py | 15 ++++++++++-----
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/supervisor/validate.py b/supervisor/validate.py
index 76ba41645..1dad79479 100644
--- a/supervisor/validate.py
+++ b/supervisor/validate.py
@@ -74,9 +74,13 @@ def dns_url(url: str) -> str:
         raise vol.Invalid("Doesn't start with dns://") from None
     address: str = url[6:]  # strip the dns:// off
     try:
-        ipaddress.ip_address(address)  # matches ipv4 or ipv6 addresses
+        ip = ipaddress.ip_address(address)  # matches ipv4 or ipv6 addresses
     except ValueError:
         raise vol.Invalid(f"Invalid DNS URL: {url}") from None
+
+    # Currently only IPv4 work with docker network
+    if ip.version != 4:
+        raise vol.Invalid(f"Only IPv4 is working for DNS: {url}") from None
     return url
 
 
diff --git a/tests/test_validate.py b/tests/test_validate.py
index b09ae2b63..c02f43f5e 100644
--- a/tests/test_validate.py
+++ b/tests/test_validate.py
@@ -26,8 +26,9 @@ async def test_dns_url_v4_good():
 
 def test_dns_url_v6_good():
     """Test the DNS validator with known-good ipv6 DNS URLs."""
-    for url in DNS_GOOD_V6:
-        assert validate.dns_url(url)
+    with pytest.raises(vol.error.Invalid):
+        for url in DNS_GOOD_V6:
+            assert validate.dns_url(url)
 
 
 def test_dns_server_list_v4():
@@ -37,16 +38,19 @@ def test_dns_server_list_v4():
 
 def test_dns_server_list_v6():
     """Test a list with v6 addresses."""
-    assert validate.dns_server_list(DNS_GOOD_V6)
+    with pytest.raises(vol.error.Invalid):
+        assert validate.dns_server_list(DNS_GOOD_V6)
 
 
 def test_dns_server_list_combined():
     """Test a list with both v4 and v6 addresses."""
     combined = DNS_GOOD_V4 + DNS_GOOD_V6
     # test the matches
-    assert validate.dns_server_list(combined)
+    with pytest.raises(vol.error.Invalid):
+        validate.dns_server_list(combined)
     # test max_length is OK still
-    assert validate.dns_server_list(combined)
+    with pytest.raises(vol.error.Invalid):
+        validate.dns_server_list(combined)
     # test that it fails when the list is too long
     with pytest.raises(vol.error.Invalid):
         validate.dns_server_list(combined + combined + combined + combined)
@@ -72,6 +76,7 @@ def test_version_complex():
     """Test version simple with good version."""
     for version in (
         "landingpage",
+        "dev",
         "1c002dd",
         "1.1.1",
         "1.0",