Monitor station events for hotspot mode

This enables NetlinkManager to monitor NL80211_CMD_NEW_STATION,
and NL80211_CMD_DEL_STATION.

This could be used for ApInterfaceImpl for monitoring associated
stations.

This also creates a new class LoggingUtils to avoid repeating code.
This also adds corresponding unit tests.

Bug: 36043922
Test: compile, unit tests, manual tests

Change-Id: I060062c0cd6250051da90658b229d786f287fad4

1 files changed, 23 insertions, 0 deletions

diff --git a/ap_interface_impl.cpp b/ap_interface_impl.cpp
index 62fa2ae..44a30b3 100644
--- a/ap_interface_impl.cpp
+++ b/ap_interface_impl.cpp
@@ -21,6 +21,7 @@
 #include "wificond/net/netlink_utils.h"
 
 #include "wificond/ap_interface_binder.h"
+#include "wificond/logging_utils.h"
 
 using android::net::wifi::IApInterface;
 using android::wifi_system::HostapdManager;
@@ -31,6 +32,8 @@ using std::vector;
 
 using EncryptionType = android::wifi_system::HostapdManager::EncryptionType;
 
+using namespace std::placeholders;
+
 namespace android {
 namespace wificond {
 
@@ -48,11 +51,18 @@ ApInterfaceImpl::ApInterfaceImpl(const string& interface_name,
   // This log keeps compiler happy.
   LOG(DEBUG) << "Created ap interface " << interface_name_
              << " with index " << interface_index_;
+
+  netlink_utils_->SubscribeStationEvent(
+      interface_index_,
+      std::bind(&ApInterfaceImpl::OnStationEvent,
+                this,
+                _1, _2));
 }
 
 ApInterfaceImpl::~ApInterfaceImpl() {
   binder_->NotifyImplDead();
   if_tool_->SetUpState(interface_name_.c_str(), false);
+  netlink_utils_->UnsubscribeStationEvent(interface_index_);
 }
 
 sp<IApInterface> ApInterfaceImpl::GetBinder() const {
@@ -104,5 +114,18 @@ bool ApInterfaceImpl::WriteHostapdConfig(const vector<uint8_t>& ssid,
   return hostapd_manager_->WriteHostapdConfig(config);
 }
 
+void ApInterfaceImpl::OnStationEvent(StationEvent event,
+                                     const vector<uint8_t>& mac_address) {
+  if (event == NEW_STATION) {
+    LOG(INFO) << "New station "
+              << LoggingUtils::GetMacString(mac_address)
+              << " associated with hotspot";
+  } else if (event == DEL_STATION) {
+    LOG(INFO) << "Station "
+              << LoggingUtils::GetMacString(mac_address)
+              << " disassociated from hotspot";
+  }
+}
+
 }  // namespace wificond
 }  // namespace android