[GR-21381] Encode hostnames passed to gethostbyname with IDN

PullRequest: graalpython/827

Author: msimacek

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/SocketModuleBuiltins.java

@@ -42,6 +42,7 @@
 
 import java.io.BufferedReader;
 import java.io.IOException;
+import java.net.IDN;
 import java.net.Inet4Address;
 import java.net.Inet6Address;
 import java.net.InetAddress;
@@ -357,7 +358,7 @@ public abstract static class GetHostByNameNode extends PythonBuiltinNode {
         @Specialization
         Object getHostByName(String name) {
             try {
-                InetAddress[] adresses = getAllByName(name);
+                InetAddress[] adresses = getAllByName(IDNtoASCII(name));
                 if (adresses.length == 0) {
                     return PNone.NONE;
                 }
@@ -366,6 +367,15 @@ Object getHostByName(String name) {
                 throw raise(PythonBuiltinClassType.OSError);
             }
         }
+
+        @TruffleBoundary
+        private String IDNtoASCII(String name) {
+            try {
+                return IDN.toASCII(name);
+            } catch (IllegalArgumentException e) {
+                throw raise(PythonBuiltinClassType.UnicodeError, "IDN encoding failed: %s", e.getMessage());
+            }
+        }
     }
 
     @Builtin(name = "getservbyname", parameterNames = {"servicename", "protocolname"})