tls: reapply servername on happy eyeballs connect

When establishing a TLS connection to a server with `autoSelectFamily`
set to `true`, the `net.Socket` will call `[kWrapConnectedHandle]()` to
reinitialize the socket (in case if it got broken during previous
connect attempts). Unfortunately, prior to this patch this resulted in a
brand new `TLSWrap` instance being created for the socket. While most of
the configuration of `TLSWrap` is restored, the `servername` was sadly
dropped and not reinitalized.
With this patch `servername` will be reinitialized if there are
`tls.connect` options present on the `TLSSocket` instance, making it
possible to connect with "Happy Eyeballs" to TLS servers that require
the servername extension.
PR-URL: #48255
Reviewed-By: Paolo Insogna <paolo@cowtech.it>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Minwoo Jung <nodecorelab@gmail.com>

Author: indutny

lib/_tls_wrap.js

@@ -814,6 +814,14 @@ TLSSocket.prototype._init = function(socket, wrap) {
 }
 }
 
+// We can only come here via [kWrapConnectedHandle]() call that happens
+// if the connection is established with `autoSelectFamily` set to `true`.
+constconnectOptions=this[kConnectOptions];
+if(!options.isServer&&connectOptions){
+if(connectOptions.servername){
+this.setServername(connectOptions.servername);
+}
+}
 
 if(options.handshakeTimeout>0)
 this.setTimeout(options.handshakeTimeout,this._handleTimeout);

test/parallel/test-https-happy-eyeballs.js

@@ -80,7 +80,8 @@ function createDnsServer(ipv6Addr, ipv4Addr, cb) {
 // Test that IPV4 is reached if IPV6 is not reachable
 {
 createDnsServer('::1','127.0.0.1',common.mustCall(function({ dnsServer, lookup }){
-constipv4Server=createServer(options,common.mustCall((_,res)=>{
+constipv4Server=createServer(options,common.mustCall((req,res)=>{
+assert.strictEqual(req.socket.servername,'example.org');
 res.writeHead(200,{Connection: 'close'});
 res.end('response-ipv4');
 }));
@@ -92,7 +93,8 @@ function createDnsServer(ipv6Addr, ipv4Addr, cb) {
  lookup,
 rejectUnauthorized: false,
 autoSelectFamily: true,
- autoSelectFamilyAttemptTimeout
+ autoSelectFamilyAttemptTimeout,
+servername: 'example.org',
 },
 (res)=>{
 assert.strictEqual(res.statusCode,200);
@@ -118,12 +120,14 @@ function createDnsServer(ipv6Addr, ipv4Addr, cb) {
 // Test that IPV4 is NOT reached if IPV6 is reachable
 if(common.hasIPv6){
 createDnsServer('::1','127.0.0.1',common.mustCall(function({ dnsServer, lookup }){
-constipv4Server=createServer(options,common.mustNotCall((_,res)=>{
+constipv4Server=createServer(options,common.mustNotCall((req,res)=>{
+assert.strictEqual(req.socket.servername,'example.org');
 res.writeHead(200,{Connection: 'close'});
 res.end('response-ipv4');
 }));
 
-constipv6Server=createServer(options,common.mustCall((_,res)=>{
+constipv6Server=createServer(options,common.mustCall((req,res)=>{
+assert.strictEqual(req.socket.servername,'example.org');
 res.writeHead(200,{Connection: 'close'});
 res.end('response-ipv6');
 }));
@@ -139,6 +143,7 @@ if (common.hasIPv6) {
 rejectUnauthorized: false,
 autoSelectFamily: true,
  autoSelectFamilyAttemptTimeout,
+servername: 'example.org',
 },
 (res)=>{
 assert.strictEqual(res.statusCode,200);