shill: Provide notification callbacks on DHCP configuration updates.

BUG=chromium-os:16257
TEST=unit tests

Change-Id: Ifef3eb4e295bea21a05bce4af440536472953a8b
Reviewed-on: http://gerrit.chromium.org/gerrit/2273
Tested-by: Darin Petkov <petkov@chromium.org>
Reviewed-by: Chris Masone <cmasone@chromium.org>
diff --git a/ipconfig.cc b/ipconfig.cc
index b386c46..12c20f0 100644
--- a/ipconfig.cc
+++ b/ipconfig.cc
@@ -34,7 +34,14 @@
 
 void IPConfig::UpdateProperties(const Properties &properties) {
   properties_ = properties;
-  // TODO(petkov): Notify listeners about the new properties.
+  if (update_callback_.get()) {
+    update_callback_->Run(this);
+  }
+}
+
+void IPConfig::RegisterUpdateCallback(
+    Callback1<IPConfigRefPtr>::Type *callback) {
+  update_callback_.reset(callback);
 }
 
 }  // namespace shill
diff --git a/ipconfig.h b/ipconfig.h
index 78ace70..5e2ae32 100644
--- a/ipconfig.h
+++ b/ipconfig.h
@@ -8,12 +8,19 @@
 #include <string>
 #include <vector>
 
+#include <base/callback_old.h>
 #include <base/memory/ref_counted.h>
+#include <base/memory/scoped_ptr.h>
+#include <gtest/gtest_prod.h>  // for FRIEND_TEST
 
 #include "shill/device.h"
 
 namespace shill {
 
+class IPConfig;
+
+typedef scoped_refptr<IPConfig> IPConfigRefPtr;
+
 // IPConfig superclass. Individual IP configuration types will inherit from this
 // class.
 class IPConfig : public base::RefCounted<IPConfig> {
@@ -37,9 +44,11 @@
   DeviceConstRefPtr device() const { return device_; }
   const std::string &GetDeviceName() const;
 
-  // Updates the IP configuration properties and notifies registered listeners
-  // about the event.
-  void UpdateProperties(const Properties &properties);
+  // Registers a callback that's executed every time the configuration
+  // properties change. Takes ownership of |callback|. Pass NULL to remove a
+  // callback. The callback's argument is a pointer to this IP configuration
+  // instance allowing clients to more easily manage multiple IP configurations.
+  void RegisterUpdateCallback(Callback1<IPConfigRefPtr>::Type *callback);
 
   const Properties &properties() const { return properties_; }
 
@@ -49,9 +58,18 @@
   virtual bool Request();
   virtual bool Renew();
 
+ protected:
+  // Updates the IP configuration properties and notifies registered listeners
+  // about the event.
+  void UpdateProperties(const Properties &properties);
+
  private:
+  FRIEND_TEST(IPConfigTest, UpdateCallback);
+  FRIEND_TEST(IPConfigTest, UpdateProperties);
+
   DeviceConstRefPtr device_;
   Properties properties_;
+  scoped_ptr<Callback1<IPConfigRefPtr>::Type> update_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(IPConfig);
 };
diff --git a/ipconfig_unittest.cc b/ipconfig_unittest.cc
index e6854b1..d5e9d35 100644
--- a/ipconfig_unittest.cc
+++ b/ipconfig_unittest.cc
@@ -2,26 +2,92 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <base/callback_old.h>
+
 #include "shill/ipconfig.h"
 #include "shill/mock_control.h"
 #include "shill/mock_device.h"
 
+using testing::Test;
+
 namespace shill {
-using ::testing::Test;
 
 class IPConfigTest : public Test {
  public:
-  IPConfigTest() :
-      device_(new MockDevice(&control_interface_, NULL, NULL, "testname", 0)) {}
+  IPConfigTest()
+      : device_(new MockDevice(&control_interface_, NULL, NULL, "testname", 0)),
+        ipconfig_(new IPConfig(device_)) {}
 
  protected:
   MockControl control_interface_;
   scoped_refptr<const MockDevice> device_;
+  IPConfigRefPtr ipconfig_;
 };
 
-TEST_F(IPConfigTest, GetDeviceNameTest) {
-  scoped_refptr<IPConfig> ipconfig(new IPConfig(device_));
-  EXPECT_EQ("testname", ipconfig->GetDeviceName());
+TEST_F(IPConfigTest, GetDeviceName) {
+  EXPECT_EQ("testname", ipconfig_->GetDeviceName());
+}
+
+TEST_F(IPConfigTest, Request) {
+  EXPECT_FALSE(ipconfig_->Request());
+}
+
+TEST_F(IPConfigTest, Renew) {
+  EXPECT_FALSE(ipconfig_->Renew());
+}
+
+TEST_F(IPConfigTest, UpdateProperties) {
+  IPConfig::Properties properties;
+  properties.address = "1.2.3.4";
+  properties.subnet_cidr = 24;
+  properties.broadcast_address = "11.22.33.44";
+  properties.gateway = "5.6.7.8";
+  properties.dns_servers.push_back("10.20.30.40");
+  properties.dns_servers.push_back("20.30.40.50");
+  properties.domain_name = "foo.org";
+  properties.domain_search.push_back("zoo.org");
+  properties.domain_search.push_back("zoo.com");
+  properties.mtu = 700;
+  ipconfig_->UpdateProperties(properties);
+  EXPECT_EQ("1.2.3.4", ipconfig_->properties().address);
+  EXPECT_EQ(24, ipconfig_->properties().subnet_cidr);
+  EXPECT_EQ("11.22.33.44", ipconfig_->properties().broadcast_address);
+  EXPECT_EQ("5.6.7.8", ipconfig_->properties().gateway);
+  ASSERT_EQ(2, ipconfig_->properties().dns_servers.size());
+  EXPECT_EQ("10.20.30.40", ipconfig_->properties().dns_servers[0]);
+  EXPECT_EQ("20.30.40.50", ipconfig_->properties().dns_servers[1]);
+  ASSERT_EQ(2, ipconfig_->properties().domain_search.size());
+  EXPECT_EQ("zoo.org", ipconfig_->properties().domain_search[0]);
+  EXPECT_EQ("zoo.com", ipconfig_->properties().domain_search[1]);
+  EXPECT_EQ("foo.org", ipconfig_->properties().domain_name);
+  EXPECT_EQ(700, ipconfig_->properties().mtu);
+}
+
+class UpdateCallbackTest {
+ public:
+  UpdateCallbackTest(IPConfigRefPtr ipconfig)
+      : ipconfig_(ipconfig),
+        called_(false) {}
+
+  void Callback(IPConfigRefPtr ipconfig) {
+    called_ = true;
+    EXPECT_EQ(ipconfig.get(), ipconfig_.get());
+  }
+
+  bool called() const { return called_; }
+
+ private:
+  IPConfigRefPtr ipconfig_;
+  bool called_;
+};
+
+TEST_F(IPConfigTest, UpdateCallback) {
+  UpdateCallbackTest callback_test(ipconfig_);
+  ASSERT_FALSE(callback_test.called());
+  ipconfig_->RegisterUpdateCallback(
+      NewCallback(&callback_test, &UpdateCallbackTest::Callback));
+  ipconfig_->UpdateProperties(IPConfig::Properties());
+  EXPECT_TRUE(callback_test.called());
 }
 
 }  // namespace shill