net, dns: socket should handle its output as input

As a consequence of #43014 ,
server sockets and others, once connected, report string family
names. But when feeding these to Socket.connect(), it passes
these to host resolution with a string for family while a numeric
family is expected internally. This results in wrong hints flags
to be set and resolution to fail.

As solution, is to add ability to handle both numeric and string
family names when doing lookup and connect.

Fixes: #44003
PR-URL: #44083
Reviewed-By: Paolo Insogna <paolo@cowtech.it>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

lib/net.js

@@ -1103,6 +1103,16 @@ Socket.prototype.connect = function(...args) {
   return this;
 };
 
+function socketToDnsFamily(family) {
+  switch (family) {
+    case 'IPv4':
+      return 4;
+    case 'IPv6':
+      return 6;
+  }
+
+  return family;
+}
 
 function lookupAndConnect(self, options) {
   const { localAddress, localPort } = options;
@@ -1145,7 +1155,7 @@ function lookupAndConnect(self, options) {
 
   if (dns === undefined) dns = require('dns');
   const dnsopts = {
-    family: options.family,
+    family: socketToDnsFamily(options.family),
     hints: options.hints || 0
   };
 

test/parallel/parallel.status

@@ -56,8 +56,6 @@ test-worker-message-port-message-before-close: PASS,FLAKY
 # https://github.com/nodejs/node/issues/43446
 test-net-connect-reset-until-connected: PASS, FLAKY
 
-[$system==aix]
-
 [$system==ibmi]
 # https://github.com/nodejs/node/pull/30819
 test-child-process-fork-net-server: SKIP