Add reverse dns lookup as a method on InternetAddress.

runtime/bin/socket.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "bin/io_buffer.h"
 #include "bin/socket.h"
 #include "bin/dartutils.h"
 #include "bin/thread.h"
 #include "bin/utils.h"
 
@@ skipping 468 matching lines @@
     } else {
       result = CObject::NewOSError(os_error);
       delete os_error;
     }
     return result;
   }
   return CObject::IllegalArgumentError();
 }
 
 
+static CObject* ReverseLookupRequest(const CObjectArray& request) {
+  if (request.Length() == 2 &&
+      request[1]->IsTypedData()) {
+    CObjectExternalUint8Array addr_object(request[1]);
+    RawAddr addr;
+    memmove(reinterpret_cast<void *>(&addr),
+            addr_object.Data(),
+            addr_object.Length());
+    OSError* os_error = NULL;

[Søren Gjesse, 2013/06/25 10:26:16]

How about this:

char host[MAX_HOST_LEN];  // NI_MAXHOST not avaialable here.
bool ok = Socket::ReverseLookup(addr, host, &os_error);
if (ok) {
  ...

Then you avoid "delete host" both here and in all platform implementations when
there is an error.

You could of cause pass MAX_HOST_LEN

bool ok = Socket::ReverseLookup(addr, host, MAX_HOST_LEN, &os_error);

And then assert it is at least NI_MAXHOST in the platform code.

[Anders Johnsen, 2013/06/25 11:27:36]

Done.

+    const char* host = Socket::ReverseLookup(addr, &os_error);
+    CObject* result = NULL;
+    if (host != NULL) {
+      result = new CObjectString(CObject::NewString(host));
+      delete[] host;
+    } else {
+      result = CObject::NewOSError(os_error);
+      delete os_error;
+    }
+    return result;
+  }
+  return CObject::IllegalArgumentError();
+}
+
+
+
 static CObject* ListInterfacesRequest(const CObjectArray& request) {
   if (request.Length() == 2 &&
       request[1]->IsInt32()) {
     CObjectInt32 type(request[1]);
     CObject* result = NULL;
     OSError* os_error = NULL;
     AddressList<InterfaceSocketAddress>* addresses = Socket::ListInterfaces(
         type.Value(), &os_error);
     if (addresses != NULL) {
       CObjectArray* array = new CObjectArray(
@@ skipping 46 matching lines @@
   if (message->type == Dart_CObject_kArray) {
     if (request.Length() > 1 && request[0]->IsInt32()) {
       CObjectInt32 request_type(request[0]);
       switch (request_type.Value()) {
         case Socket::kLookupRequest:
           response = LookupRequest(request);
           break;
         case Socket::kListInterfacesRequest:
           response = ListInterfacesRequest(request);
           break;
+        case Socket::kReverseLookupRequest:
+          response = ReverseLookupRequest(request);
+          break;
         default:
           UNREACHABLE();
       }
     }
   }
 
   Dart_PostCObject(reply_port_id, response->AsApiCObject());
 }
 
 
@@ skipping 66 matching lines @@
   return Dart_SetNativeInstanceField(socket, kSocketIdNativeField, id);
 }
 
 
 Dart_Handle Socket::GetSocketIdNativeField(Dart_Handle socket, intptr_t* id) {
   return Dart_GetNativeInstanceField(socket, kSocketIdNativeField, id);
 }
 
 }  // namespace bin
 }  // namespace dart