[CrOS Tether] Add the notion of a tether DeviceState.

chromeos/network/network_state_handler.cc

Index: chromeos/network/network_state_handler.cc
diff --git a/chromeos/network/network_state_handler.cc b/chromeos/network/network_state_handler.cc
index 3268f9f37cebeed3a274114d90df2188b9624889..6bfc3ab3c0339a25469b53e808a3b5c5ea94b62d 100644
--- a/chromeos/network/network_state_handler.cc
+++ b/chromeos/network/network_state_handler.cc
@@ -21,7 +21,9 @@
 #include "base/values.h"
 #include "chromeos/chromeos_switches.h"
 #include "chromeos/network/device_state.h"
+#include "chromeos/network/network_connection_handler.h"
 #include "chromeos/network/network_event_log.h"
+#include "chromeos/network/network_handler_callbacks.h"
 #include "chromeos/network/network_state.h"
 #include "chromeos/network/network_state_handler_observer.h"
 #include "chromeos/network/tether_constants.h"
@@ -126,9 +128,7 @@ NetworkStateHandler::TechnologyState NetworkStateHandler::GetTechnologyState(
   std::string technology = GetTechnologyForType(type);
 
   if (technology == kTypeTether) {
-    bool is_tether_enabled = base::CommandLine::ForCurrentProcess()->HasSwitch(
-        chromeos::switches::kEnableTether);
-    return is_tether_enabled ? TECHNOLOGY_ENABLED : TECHNOLOGY_UNAVAILABLE;
+    return tether_technology_state_;
   }
 
   TechnologyState state;
@@ -154,6 +154,28 @@ void NetworkStateHandler::SetTechnologyEnabled(
     const network_handler::ErrorCallback& error_callback) {
   std::vector<std::string> technologies = GetTechnologiesForType(type);
   for (const std::string& technology : technologies) {
+    if (technology == kTypeTether) {
+      if (tether_technology_state_ != TECHNOLOGY_ENABLED &&
+          tether_technology_state_ != TECHNOLOGY_AVAILABLE) {
+        // SetTechnologyEnabled() should only be called if the device is already
+        // in either the TECHNOLOGY_ENABLED or TECHNOLOGY_AVAILABLE states. If
+        // this is not the case, invoke the error callback.

[stevenjb, 2017/04/20 20:01:11]

nit: I think this is clear from the code (i..e the comment doesn't seem to add
anything)

[Kyle Horimoto, 2017/04/20 20:49:20]

Done.

+        NET_LOG(ERROR) << "SetTechnologyEnabled() called for the Tether "
+                       << "DeviceState, but the current state was not "
+                       << "TECHNOLOGY_ENABLED or TECHNOLOGY_AVAILABLE.";
+        network_handler::RunErrorCallback(
+            error_callback, kTetherDevicePath,
+            NetworkConnectionHandler::kEnabledOrDisabledWhenNotAvailable, "");
+        continue;
+      }
+
+      // Tether does not exist in Shill, so set |tether_technology_state_| and
+      // skip the below interactions with |shill_property_handler_|.
+      tether_technology_state_ =
+          enabled ? TECHNOLOGY_ENABLED : TECHNOLOGY_AVAILABLE;
+      continue;
+    }
+
     if (!shill_property_handler_->IsTechnologyAvailable(technology))
       continue;
     NET_LOG_USER("SetTechnologyEnabled",
@@ -165,11 +187,53 @@ void NetworkStateHandler::SetTechnologyEnabled(
   NotifyDeviceListChanged();
 }
 
+void NetworkStateHandler::SetTetherTechnologyState(
+    TechnologyState technology_state) {
+  if (tether_technology_state_ == technology_state)
+    return;
+
+  tether_technology_state_ = technology_state;
+
+  // Signal Device/Technology state changed.

[stevenjb, 2017/04/20 20:01:11]

I would actually call EnsureTetherDeviceState() explicitly here; this is the
only place that should affect whether or not a device state exists.

[Kyle Horimoto, 2017/04/20 20:49:20]

Done.

+  NotifyDeviceListChanged();
+}
+
+void NetworkStateHandler::SetTetherScanState(bool is_scanning) {
+  DeviceState* tether_device_state =
+      GetModifiableDeviceState(kTetherDevicePath);
+  DCHECK(tether_device_state);
+
+  bool was_scanning = tether_device_state->scanning();
+  tether_device_state->set_scanning(is_scanning);
+
+  if (was_scanning && !is_scanning) {
+    // If a scan was in progress but has completed, notify observers.
+    NotifyScanCompleted(tether_device_state);
+  }
+}
+
 void NetworkStateHandler::SetProhibitedTechnologies(
     const std::vector<std::string>& prohibited_technologies,
     const network_handler::ErrorCallback& error_callback) {
-  shill_property_handler_->SetProhibitedTechnologies(prohibited_technologies,
-                                                     error_callback);
+  // Make a copy of |prohibited_technologies| since the list may be edited
+  // within this function.
+  std::vector<std::string> prohibited_technologies_copy =
+      prohibited_technologies;
+
+  for (auto it = prohibited_technologies_copy.begin();
+       it < prohibited_technologies_copy.end(); ++it) {
+    if (*it == kTypeTether) {
+      // If Tether networks are prohibited, set |tether_technology_state_| and
+      // remove |kTypeTether| from the list before passing it to
+      // |shill_property_handler_| below. Shill does not have a concept of
+      // Tether networks, so it cannot prohibit that technology type.
+      tether_technology_state_ = TECHNOLOGY_PROHIBITED;
+      it = prohibited_technologies_copy.erase(it);
+    }
+  }
+
+  shill_property_handler_->SetProhibitedTechnologies(
+      prohibited_technologies_copy, error_callback);
   // Signal Device/Technology state changed.
   NotifyDeviceListChanged();
 }
@@ -300,7 +364,7 @@ const NetworkState* NetworkStateHandler::FirstNetworkByType(
   if (!network_list_sorted_)
     SortNetworkList();  // Sort to ensure visible networks are listed first.
 
-  // If |type| matches tether networks and at least one tether network is
+  // If |type| matches Tether networks and at least one Tether network is
   // present, return the first network (since it has been sorted already).
   if (type.MatchesPattern(NetworkTypePattern::Tether()) &&
       !tether_network_list_.empty()) {
@@ -323,9 +387,14 @@ const NetworkState* NetworkStateHandler::FirstNetworkByType(
 std::string NetworkStateHandler::FormattedHardwareAddressForType(
     const NetworkTypePattern& type) const {
   const NetworkState* network = ConnectedNetworkByType(type);
+  if (network && network->type() == kTypeTether) {
+    // If this is a Tether network, get the MAC address corresponding to that
+    // network instead.
+    network = GetNetworkStateFromGuid(network->tether_guid());
+  }
   const DeviceState* device = network ? GetDeviceState(network->device_path())
                                       : GetDeviceStateByType(type);
-  if (!device)
+  if (!device || device->mac_address().empty())
     return std::string();
   return network_util::FormattedMacAddress(device->mac_address());
 }
@@ -361,7 +430,7 @@ void NetworkStateHandler::GetNetworkListByType(const NetworkTypePattern& type,
 
   if (type.Equals(NetworkTypePattern::Tether()) ||
       (limit != 0 && count >= limit)) {
-    // If only searching for tether networks, there is no need to continue
+    // If only searching for Tether networks, there is no need to continue
     // searching through other network types; likewise, if the limit has already
     // been reached, there is no need to continue searching.
     return;
@@ -432,6 +501,12 @@ void NetworkStateHandler::AddTetherNetworkState(const std::string& guid,
   DCHECK(battery_percentage >= 0 && battery_percentage <= 100);
   DCHECK(signal_strength >= 0 && signal_strength <= 100);
 
+  if (tether_technology_state_ != TECHNOLOGY_ENABLED) {
+    NET_LOG(ERROR) << "AddTetherNetworkState() called when Tether networks "
+                   << "are not enabled. Cannot add NetworkState.";
+    return;
+  }
+
   // If the network already exists, do nothing.
   if (GetNetworkStateFromGuid(guid)) {
     NET_LOG(ERROR) << "AddTetherNetworkState: " << name
@@ -463,6 +538,12 @@ bool NetworkStateHandler::UpdateTetherNetworkProperties(
     const std::string& carrier,
     int battery_percentage,
     int signal_strength) {
+  if (tether_technology_state_ != TECHNOLOGY_ENABLED) {
+    NET_LOG(ERROR) << "UpdateTetherNetworkProperties() called when Tether "
+                   << "networks are not enabled. Cannot update.";
+    return false;
+  }
+
   NetworkState* tether_network_state = GetModifiableNetworkStateFromGuid(guid);
   if (!tether_network_state)
     return false;
@@ -494,6 +575,13 @@ void NetworkStateHandler::RemoveTetherNetworkState(const std::string& guid) {
 bool NetworkStateHandler::AssociateTetherNetworkStateWithWifiNetwork(
     const std::string& tether_network_guid,
     const std::string& wifi_network_guid) {
+  if (tether_technology_state_ != TECHNOLOGY_ENABLED) {
+    NET_LOG(ERROR) << "AssociateTetherNetworkStateWithWifiNetwork() called "
+                   << "when Tether networks are not enabled. Cannot "
+                   << "associate.";
+    return false;
+  }
+
   NetworkState* tether_network =
       GetModifiableNetworkStateFromGuid(tether_network_guid);
   if (!tether_network) {
@@ -525,14 +613,14 @@ bool NetworkStateHandler::AssociateTetherNetworkStateWithWifiNetwork(
 
 void NetworkStateHandler::SetTetherNetworkStateDisconnected(
     const std::string& guid) {
-  // TODO(khorimoto): Remove the tether network as the default network, and
+  // TODO(khorimoto): Remove the Tether network as the default network, and
   // send a connection status change.
   SetTetherNetworkStateConnectionState(guid, shill::kStateDisconnect);
 }
 
 void NetworkStateHandler::SetTetherNetworkStateConnecting(
     const std::string& guid) {
-  // TODO(khorimoto): Set the tether network as the default network, and send
+  // TODO(khorimoto): Set the Tether network as the default network, and send
   // a connection status change.
   SetTetherNetworkStateConnectionState(guid, shill::kStateConfiguration);
 }
@@ -564,6 +652,42 @@ void NetworkStateHandler::SetTetherNetworkStateConnectionState(
   NotifyNetworkListChanged();
 }
 
+void NetworkStateHandler::EnsureTetherDeviceState() {
+  bool should_be_present =
+      tether_technology_state_ != TechnologyState::TECHNOLOGY_UNAVAILABLE;
+
+  for (auto it = device_list_.begin(); it < device_list_.end(); ++it) {
+    std::string path = (*it)->path();
+    if (path == kTetherDevicePath) {
+      // If the Tether DeviceState is in the list and it should not be, remove
+      // it and return. If it is in the list and it should be, the list is
+      // already valid, so return without removing it.
+      if (!should_be_present) {
+        device_list_.erase(it);
+      }

[stevenjb, 2017/04/20 20:01:11]

nit: no {}

[Kyle Horimoto, 2017/04/20 20:49:20]

Done.

+      return;
+    }
+  }
+
+  if (!should_be_present) {
+    // If the Tether DeviceState was not in the list and it should not be, the
+    // list is already valid, so return.
+    return;
+  }
+
+  // The Tether DeviceState is not present in the list, but it should be. Since
+  // Tether networks are not recognized by Shill, they will never receive an
+  // update, so set properties on the state here.
+  std::unique_ptr<ManagedState> tether_device_state = ManagedState::Create(
+      ManagedState::ManagedType::MANAGED_TYPE_DEVICE, kTetherDevicePath);
+  tether_device_state->set_update_received();
+  tether_device_state->set_update_requested(false);
+  tether_device_state->set_name(kTetherDeviceName);
+  tether_device_state->set_type(kTypeTether);
+
+  device_list_.push_back(std::move(tether_device_state));
+}
+
 void NetworkStateHandler::GetDeviceList(DeviceStateList* list) const {
   GetDeviceListByType(NetworkTypePattern::Default(), list);
 }
@@ -572,6 +696,7 @@ void NetworkStateHandler::GetDeviceListByType(const NetworkTypePattern& type,
                                               DeviceStateList* list) const {
   DCHECK(list);
   list->clear();
+
   for (auto iter = device_list_.begin(); iter != device_list_.end(); ++iter) {
     const DeviceState* device = (*iter)->AsDeviceState();
     DCHECK(device);
@@ -726,6 +851,10 @@ void NetworkStateHandler::UpdateManagedList(ManagedState::ManagedType type,
     list_entries.insert(path);
   }
 
+  if (type == ManagedState::ManagedType::MANAGED_TYPE_DEVICE) {
+    EnsureTetherDeviceState();

[stevenjb, 2017/04/20 20:01:11]

Rather than re-creating the tether state here, you could do:

// Move any existing Tether device to |managed_list|.
auto iter = managed_map.find(Tether);
if (iter != managed_map.end()) {
  managed_list->push_back(std::move(iter->second));
  managed_map.erase(iter);
}

[Kyle Horimoto, 2017/04/20 20:49:19]

Done.

+  }
+
   if (type != ManagedState::ManagedType::MANAGED_TYPE_NETWORK)
     return;
 
@@ -971,7 +1100,7 @@ void NetworkStateHandler::ManagedStateListChanged(
   }
 }
 
-// TODO(khorimoto): Add sorting for the tether network list as well.
+// TODO(khorimoto): Add sorting for the Tether network list as well.
 void NetworkStateHandler::SortNetworkList() {
   // Note: usually active networks will precede inactive networks, however
   // this may briefly be untrue during state transitions (e.g. a network may
@@ -1106,6 +1235,7 @@ void NetworkStateHandler::NotifyDeviceListChanged() {
   SCOPED_NET_LOG_IF_SLOW();
   NET_LOG_DEBUG("NOTIFY:DeviceListChanged",
                 base::StringPrintf("Size:%" PRIuS, device_list_.size()));
+  EnsureTetherDeviceState();
   for (auto& observer : observers_)
     observer.DeviceListChanged();
 }
@@ -1275,6 +1405,8 @@ std::vector<std::string> NetworkStateHandler::GetTechnologiesForType(
     technologies.emplace_back(shill::kTypeBluetooth);
   if (type.MatchesType(shill::kTypeVPN))
     technologies.emplace_back(shill::kTypeVPN);
+  if (type.MatchesType(kTypeTether))
+    technologies.emplace_back(kTypeTether);
 
   CHECK_GT(technologies.size(), 0ul);
   return technologies;