Check for ip address in dns_cares.lookup

lib/dns_cares.js

@@ -95,19 +95,30 @@ exports.getHostByName = function (domain, callback) {
 
 // Easy DNS A/AAAA look up
 exports.lookup = function (domain, callback) {
-  channel.getHostByName(domain, dns.AF_INET, function (err, domains4) {
+  var addressType = dns.isIP(domain);
-    if (domains4 && domains4.length) {
+  if (addressType) {
-      callback(null, domains4[0], 4);
+    process.nextTick(function () {
-    } else {
+      callback(null, domain, addressType);
-      channel.getHostByName(domain, dns.AF_INET6, function (err, domains6) {
+    });
-        if (domains6 && domains6.length) {
+  } else {
-          callback(null, domains6[0], 6);
+    sys.puts('AF_INET look up ' + domain);
-        } else {
+    channel.getHostByName(domain, dns.AF_INET, function (err, domains4) {
-          callback(err, []);
+      sys.puts('AF_INET result ' + domain + ' ' + sys.inspect(domains4));
-        }
+      if (domains4 && domains4.length) {
-      });
+        callback(null, domains4[0], 4);
-    }
+      } else {
-  });
+        sys.puts('AF_INET6 look up ' + domain);
+        channel.getHostByName(domain, dns.AF_INET6, function (err, domains6) {
+          sys.puts('AF_INET6 result ' + domain + ' ' + sys.inspect(domains6));
+          if (domains6 && domains6.length) {
+            callback(null, domains6[0], 6);
+          } else {
+            callback(err, []);
+          }
+        });
+      }
+    });
+  }
 };
 
 

src/node_cares.cc

@@ -13,6 +13,31 @@ namespace node {
 using namespace v8;
 
 
+static Handle<Value> IsIP(const Arguments& args) {
+  HandleScope scope;
+  
+  if (!args[0]->IsString()) {
+    return scope.Close(Integer::New(4));
+  }
+
+  String::Utf8Value s(args[0]->ToString());
+
+  // avoiding buffer overflows in the following strcat
+  // 2001:0db8:85a3:08d3:1319:8a2e:0370:7334
+  // 39 = max ipv6 address.
+  if (s.length() > INET6_ADDRSTRLEN) {
+    return scope.Close(Integer::New(0));
+  }
+
+  struct sockaddr_in6 a;
+
+  if (inet_pton(AF_INET, *s, &(a.sin6_addr)) > 0) return scope.Close(Integer::New(4));
+  if (inet_pton(AF_INET6, *s, &(a.sin6_addr)) > 0) return scope.Close(Integer::New(6));
+
+  return scope.Close(Integer::New(0));
+}
+
+
 class Channel : public ObjectWrap {
  public:
   static void Initialize(Handle<Object> target);
@@ -104,6 +129,8 @@ void Cares::Initialize(Handle<Object> target) {
   target->Set(String::NewSymbol("EREFUSED"), Integer::New(ARES_EREFUSED));
   target->Set(String::NewSymbol("SERVFAIL"), Integer::New(ARES_ESERVFAIL));
 
+  NODE_SET_METHOD(target, "isIP", IsIP);
+
   Channel::Initialize(target);
 }
 
@@ -657,4 +684,6 @@ void Channel::SockStateCb(void *data, int sock, int read, int write) {
 }
 
 
+
+
 }  // namespace node

test/simple/test-c-ares.js

@@ -15,14 +15,24 @@ dns.getHostByName('127.0.0.1', function (error, result) {
    assert.deepEqual(['127.0.0.1'], result);
 });
 
-dns.lookup('127.0.0.1', function (error, result, ipVersion) {
+dns.lookup(null, function (error, result, addressType) {
-   assert.deepEqual('127.0.0.1', result);
+   assert.equal(null, result);
-   assert.equal(4, ipVersion);
+   assert.equal(4, addressType);
 });
 
-dns.lookup('ipv6.google.com', function (error, result, ipVersion) {
+dns.lookup('127.0.0.1', function (error, result, addressType) {
+   assert.equal('127.0.0.1', result);
+   assert.equal(4, addressType);
+});
+
+dns.lookup('::1', function (error, result, addressType) {
+   assert.equal('::1', result);
+   assert.equal(6, addressType);
+});
+
+dns.lookup('ipv6.google.com', function (error, result, addressType) {
    if (error) throw error;
    p(arguments);
    //assert.equal('string', typeof result);
-   assert.equal(6, ipVersion);
+   assert.equal(6, addressType);
 });