1 //
2 // Copyright (C) 2012 The Android Open Source Project
3 //
4 // Licensed under the Apache License, Version 2.0 (the "License");
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
7 //
8 //      http://www.apache.org/licenses/LICENSE-2.0
9 //
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
15 //
16 
17 #include "update_engine/cros/connection_manager.h"
18 
19 #include <memory>
20 #include <set>
21 #include <string>
22 
23 #include <base/stl_util.h>
24 #include <base/strings/string_util.h>
25 #include <policy/device_policy.h>
26 #include <shill/dbus-constants.h>
27 #include <shill/dbus-proxies.h>
28 
29 #include "update_engine/common/connection_utils.h"
30 #include "update_engine/common/prefs.h"
31 #include "update_engine/common/system_state.h"
32 #include "update_engine/common/utils.h"
33 #include "update_engine/cros/shill_proxy.h"
34 #include "update_engine/cros/update_attempter.h"
35 
36 using org::chromium::flimflam::ManagerProxyInterface;
37 using org::chromium::flimflam::ServiceProxyInterface;
38 using std::set;
39 using std::string;
40 
41 namespace chromeos_update_engine {
42 
43 namespace connection_manager {
CreateConnectionManager()44 std::unique_ptr<ConnectionManagerInterface> CreateConnectionManager() {
45   return std::unique_ptr<ConnectionManagerInterface>(
46       new ConnectionManager(new ShillProxy()));
47 }
48 }  // namespace connection_manager
49 
ConnectionManager(ShillProxyInterface * shill_proxy)50 ConnectionManager::ConnectionManager(ShillProxyInterface* shill_proxy)
51     : shill_proxy_(shill_proxy) {}
52 
IsUpdateAllowedOver(ConnectionType type,ConnectionTethering tethering) const53 bool ConnectionManager::IsUpdateAllowedOver(
54     ConnectionType type, ConnectionTethering tethering) const {
55   if (type != ConnectionType::kCellular) {
56     if (tethering != ConnectionTethering::kConfirmed) {
57       return true;
58     }
59 
60     // Treat this connection as if it is a cellular connection.
61     LOG(INFO)
62         << "Current connection is confirmed tethered, using Cellular setting.";
63   }
64 
65   const policy::DevicePolicy* device_policy =
66       SystemState::Get()->device_policy();
67 
68   // The device_policy is loaded in a lazy way before an update check. Load
69   // it now from the libbrillo cache if it wasn't already loaded.
70   if (!device_policy) {
71     UpdateAttempter* update_attempter = SystemState::Get()->update_attempter();
72     if (update_attempter) {
73       update_attempter->RefreshDevicePolicy();
74       device_policy = SystemState::Get()->device_policy();
75     }
76   }
77 
78   if (!device_policy) {
79     // Device policy fails to be loaded (possibly due to guest account). We
80     // do not check the local user setting here, which should be checked by
81     // |OmahaRequestAction| during checking for update.
82     LOG(INFO) << "Allowing updates over cellular as device policy fails to be "
83                  "loaded.";
84     return true;
85   }
86 
87   set<string> allowed_types;
88   if (device_policy->GetAllowedConnectionTypesForUpdate(&allowed_types)) {
89     // The update setting is enforced by the device policy.
90 
91     // TODO(crbug.com/1054279): Use base::Contains after uprev to r680000.
92     if (allowed_types.find(shill::kTypeCellular) == allowed_types.end()) {
93       LOG(INFO) << "Disabling updates over cellular connection as it's not "
94                    "allowed in the device policy.";
95       return false;
96     }
97 
98     LOG(INFO) << "Allowing updates over cellular per device policy.";
99     return true;
100   }
101 
102   // If there's no update setting in the device policy, we do not check
103   // the local user setting here, which should be checked by
104   // |OmahaRequestAction| during checking for update.
105   LOG(INFO) << "Allowing updates over cellular as device policy does "
106                "not include update setting.";
107   return true;
108 }
109 
IsAllowedConnectionTypesForUpdateSet() const110 bool ConnectionManager::IsAllowedConnectionTypesForUpdateSet() const {
111   const policy::DevicePolicy* device_policy =
112       SystemState::Get()->device_policy();
113   if (!device_policy) {
114     LOG(INFO) << "There's no device policy loaded yet.";
115     return false;
116   }
117 
118   set<string> allowed_types;
119   if (!device_policy->GetAllowedConnectionTypesForUpdate(&allowed_types)) {
120     return false;
121   }
122 
123   return true;
124 }
125 
GetConnectionProperties(ConnectionType * out_type,ConnectionTethering * out_tethering)126 bool ConnectionManager::GetConnectionProperties(
127     ConnectionType* out_type, ConnectionTethering* out_tethering) {
128   dbus::ObjectPath default_service_path;
129   TEST_AND_RETURN_FALSE(GetDefaultServicePath(&default_service_path));
130   if (!default_service_path.IsValid())
131     return false;
132   // Shill uses the "/" service path to indicate that it is not connected.
133   if (default_service_path.value() == "/") {
134     *out_type = ConnectionType::kDisconnected;
135     *out_tethering = ConnectionTethering::kUnknown;
136     return true;
137   }
138   TEST_AND_RETURN_FALSE(
139       GetServicePathProperties(default_service_path, out_type, out_tethering));
140   return true;
141 }
142 
GetDefaultServicePath(dbus::ObjectPath * out_path)143 bool ConnectionManager::GetDefaultServicePath(dbus::ObjectPath* out_path) {
144   brillo::VariantDictionary properties;
145   brillo::ErrorPtr error;
146   ManagerProxyInterface* manager_proxy = shill_proxy_->GetManagerProxy();
147   if (!manager_proxy)
148     return false;
149   TEST_AND_RETURN_FALSE(manager_proxy->GetProperties(&properties, &error));
150 
151   const auto& prop_default_service =
152       properties.find(shill::kDefaultServiceProperty);
153   if (prop_default_service == properties.end())
154     return false;
155 
156   *out_path = prop_default_service->second.TryGet<dbus::ObjectPath>();
157   return out_path->IsValid();
158 }
159 
GetServicePathProperties(const dbus::ObjectPath & path,ConnectionType * out_type,ConnectionTethering * out_tethering)160 bool ConnectionManager::GetServicePathProperties(
161     const dbus::ObjectPath& path,
162     ConnectionType* out_type,
163     ConnectionTethering* out_tethering) {
164   // We create and dispose the ServiceProxyInterface on every request.
165   std::unique_ptr<ServiceProxyInterface> service =
166       shill_proxy_->GetServiceForPath(path);
167 
168   brillo::VariantDictionary properties;
169   brillo::ErrorPtr error;
170   TEST_AND_RETURN_FALSE(service->GetProperties(&properties, &error));
171 
172   // Populate the out_tethering.
173   const auto& prop_tethering = properties.find(shill::kTetheringProperty);
174   if (prop_tethering == properties.end()) {
175     // Set to Unknown if not present.
176     *out_tethering = ConnectionTethering::kUnknown;
177   } else {
178     // If the property doesn't contain a string value, the empty string will
179     // become kUnknown.
180     *out_tethering = connection_utils::ParseConnectionTethering(
181         prop_tethering->second.TryGet<string>());
182   }
183 
184   // Populate the out_type property.
185   const auto& prop_type = properties.find(shill::kTypeProperty);
186   if (prop_type == properties.end()) {
187     // Set to Unknown if not present.
188     *out_type = ConnectionType::kUnknown;
189     return false;
190   }
191 
192   string type_str = prop_type->second.TryGet<string>();
193   if (type_str == shill::kTypeVPN) {
194     const auto& prop_physical =
195         properties.find(shill::kPhysicalTechnologyProperty);
196     if (prop_physical == properties.end()) {
197       LOG(ERROR) << "No PhysicalTechnology property found for a VPN"
198                     " connection (service: "
199                  << path.value() << "). Returning default kUnknown value.";
200       *out_type = ConnectionType::kUnknown;
201     } else {
202       *out_type = connection_utils::ParseConnectionType(
203           prop_physical->second.TryGet<string>());
204     }
205   } else {
206     *out_type = connection_utils::ParseConnectionType(type_str);
207   }
208   return true;
209 }
210 
211 }  // namespace chromeos_update_engine
212