Merge branch 'ticket28141'

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Fixed
 
 - Update python minimal version in setup (#28043)
+- Catch unhandled exception when we fail to resolve a domain name (#28141)
 
 ### Changed
 

sbws/globals.py

@@ -68,8 +68,16 @@ def touch_file(fname, times=None):
 
 def resolve(hostname, ipv4_only=False, ipv6_only=False):
     assert not (ipv4_only and ipv6_only)
+    results = []
+    try:
+        results = socket.getaddrinfo(hostname, 0)
+    except socket.gaierror:
+        log.warn(
+            'Unable to resolve %s hostname. Returning empty list of addresses',
+            hostname)
+        return []
     ret = set()
-    for result in socket.getaddrinfo(hostname, 0):
+    for result in results:
         fam, _, _, _, addr = result
         if fam == socket.AddressFamily.AF_INET6 and not ipv4_only:
             ret.add(addr[0])

sbws/lib/relaylist.py

@@ -120,7 +120,10 @@ class Relay:
             #
             # Also, only use the first ipv4/6 we get even if there is more than
             # one.
-            host = resolve(host)[0]
+            results = resolve(host)
+            if not len(results):
+                return False
+            host = results[0]
         assert is_valid_ipv4_address(host) or is_valid_ipv6_address(host)
         return self.exit_policy.can_exit_to(host, port)