Add reverse dns lookup as a method on InternetAddress.

runtime/bin/socket.cc

Index: runtime/bin/socket.cc
diff --git a/runtime/bin/socket.cc b/runtime/bin/socket.cc
index a5e64dd2095f712c06bc49b5ae86eb603353494e..ee40ec8d4d3fa1810c3fd6658f6c0acef0d76b06 100644
--- a/runtime/bin/socket.cc
+++ b/runtime/bin/socket.cc
@@ -486,6 +486,31 @@ static CObject* LookupRequest(const CObjectArray& request) {
 }
 
 
+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()) {
@@ -552,6 +577,9 @@ void SocketService(Dart_Port dest_port_id,
         case Socket::kListInterfacesRequest:
           response = ListInterfacesRequest(request);
           break;
+        case Socket::kReverseLookupRequest:
+          response = ReverseLookupRequest(request);
+          break;
         default:
           UNREACHABLE();
       }