Implement OnGetNetworks for net.mojom

components/arc/net/arc_net_host_impl.cc

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/arc/net/arc_net_host_impl.h"
+
+#include <string>
+#include <vector>
+
+#include "base/logging.h"
+#include "base/posix/eintr_wrapper.h"
+#include "base/thread_task_runner_handle.h"
+#include "base/time/time.h"
+#include "chromeos/network/network_util.h"
+#include "chromeos/network/onc/onc_utils.h"

[stevenjb, 2016/01/20 01:43:42]

This should fail to compile on non chromeos platforms?

[cernekee, 2016/01/22 19:58:41]

Acknowledged.

+#include "components/arc/arc_bridge_service.h"
+#include "third_party/mojo/src/mojo/edk/embedder/embedder.h"
+
+namespace {
+
+const int kGetNetworksListLimit = 100;
+
+}  // namespace
+
+namespace arc {
+
+ArcNetHostImpl::ArcNetHostImpl(ArcBridgeService* arc_bridge_service)
+    : arc_bridge_service_(arc_bridge_service),
+      binding_(this),
+      weak_factory_(this) {
+  arc_bridge_service->AddObserver(this);
+  if (arc_bridge_service->net_instance())
+    OnNetInstanceReady();
+}
+
+ArcNetHostImpl::~ArcNetHostImpl() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  arc_bridge_service_->RemoveObserver(this);
+}
+
+void ArcNetHostImpl::OnNetInstanceReady() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  NetHostPtr host;
+  binding_.Bind(GetProxy(&host));
+  arc_bridge_service_->net_instance()->Init(std::move(host));
+}
+
+void ArcNetHostImpl::GetNetworks(bool configured_only,
+                                 bool visible_only,
+                                 const GetNetworksCallback& callback) {
+  NetworkDataPtr data = NetworkData::New();
+  data->status = NETWORK_RESULT_SUCCESS;
+
+  // Retrieve list of nearby wifi networks
+  chromeos::NetworkTypePattern network_pattern =
+      chromeos::onc::NetworkTypePatternFromOncType(onc::network_type::kWiFi);
+  scoped_ptr<base::ListValue> network_properties_list =
+      chromeos::network_util::TranslateNetworkListToONC(

[dcheng, 2016/01/22 07:17:43]

Can we just call GetNetworkListByType() directly? It seems like it'd be more
straightforward (and type safe) than having to extract everything from
base::Value.

[cernekee, 2016/01/22 19:58:41]

Not sure - I think abhishekbh and stevenjb made a decision early-on to stick
with ONC interfaces.  Possibly because ONC is our published API so it's less
likely to break ARC++ if the underlying implementation changes.

[stevenjb, 2016/01/22 21:08:28]

ONC is preferred for high level communication between processes. It is
(reasonably) well documented and stable. It is definitely a better choice.

Ideally we should be passing this ListValue directly to the caller, i.e. there
ought to be a translation utility that can convert base::ListValue ->
NetworkData.networks. (Does Mojo have a way to distinguish required properties
from optional ones?).

In the short term, this seems fine as-is. GetInteger and GetString do type
checking so there shouldn't be any type safety issues here.

[dcheng, 2016/01/23 05:12:41]

They can fail though (for example, if the format of the underlying data ever
changes), and there's no asserts that GetString() or GetInteger succeed.
Obviously this should "never happen" but still...

+          network_pattern, configured_only, visible_only,
+          kGetNetworksListLimit);
+
+  // Extract info for each network and add it to the list.
+  for (base::Value* value : *network_properties_list) {
+    WifiConfigurationPtr wc = WifiConfiguration::New();
+
+    base::DictionaryValue* network_dict = nullptr;
+    value->GetAsDictionary(&network_dict);
+    DCHECK(network_dict);
+
+    // kName is a post-processed version of kHexSSID.
+    std::string tmp;
+    network_dict->GetString(onc::network_config::kName, &tmp);
+    wc->ssid = tmp;
+
+    base::DictionaryValue* wifi_dict = nullptr;
+    network_dict->GetDictionary(onc::network_config::kWiFi, &wifi_dict);
+    DCHECK(wifi_dict);
+
+    wifi_dict->GetInteger(onc::wifi::kFrequency, &wc->frequency);
+    wifi_dict->GetInteger(onc::wifi::kSignalStrength, &wc->signal_strength);
+    wifi_dict->GetString(onc::wifi::kSecurity, &tmp);
+    wc->security = tmp;
+    wifi_dict->GetString(onc::wifi::kBSSID, &tmp);
+    wc->bssid = tmp;
+
+    data->networks.push_back(std::move(wc));
+  }
+
+  callback.Run(std::move(data));
+}
+
+}  // namespace arc