1 /*
2  * Copyright (C) 2019 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 <net/if.h>
18 #include <cstddef>
19 #include <iostream>
20 #include <limits>
21 #include <random>
22 
23 #include <android-base/logging.h>
24 #include <android-base/macros.h>
25 #include <private/android_filesystem_config.h>
26 
27 #undef NAN
28 #include "wifi_iface_util.h"
29 
30 namespace {
31 // Constants to set the local bit & clear the multicast bit.
32 constexpr uint8_t kMacAddressMulticastMask = 0x01;
33 constexpr uint8_t kMacAddressLocallyAssignedMask = 0x02;
34 }  // namespace
35 
36 namespace android {
37 namespace hardware {
38 namespace wifi {
39 namespace V1_4 {
40 namespace implementation {
41 namespace iface_util {
42 
WifiIfaceUtil(const std::weak_ptr<wifi_system::InterfaceTool> iface_tool)43 WifiIfaceUtil::WifiIfaceUtil(
44     const std::weak_ptr<wifi_system::InterfaceTool> iface_tool)
45     : iface_tool_(iface_tool),
46       random_mac_address_(nullptr),
47       event_handlers_map_() {}
48 
getFactoryMacAddress(const std::string & iface_name)49 std::array<uint8_t, 6> WifiIfaceUtil::getFactoryMacAddress(
50     const std::string& iface_name) {
51     return iface_tool_.lock()->GetFactoryMacAddress(iface_name.c_str());
52 }
53 
setMacAddress(const std::string & iface_name,const std::array<uint8_t,6> & mac)54 bool WifiIfaceUtil::setMacAddress(const std::string& iface_name,
55                                   const std::array<uint8_t, 6>& mac) {
56 #ifndef WIFI_AVOID_IFACE_RESET_MAC_CHANGE
57     if (!iface_tool_.lock()->SetUpState(iface_name.c_str(), false)) {
58         LOG(ERROR) << "SetUpState(false) failed.";
59         return false;
60     }
61 #endif
62     if (!iface_tool_.lock()->SetMacAddress(iface_name.c_str(), mac)) {
63         LOG(ERROR) << "SetMacAddress failed.";
64         return false;
65     }
66 #ifndef WIFI_AVOID_IFACE_RESET_MAC_CHANGE
67     if (!iface_tool_.lock()->SetUpState(iface_name.c_str(), true)) {
68         LOG(ERROR) << "SetUpState(true) failed.";
69         return false;
70     }
71 #endif
72     IfaceEventHandlers event_handlers = {};
73     const auto it = event_handlers_map_.find(iface_name);
74     if (it != event_handlers_map_.end()) {
75         event_handlers = it->second;
76     }
77     if (event_handlers.on_state_toggle_off_on != nullptr) {
78         event_handlers.on_state_toggle_off_on(iface_name);
79     }
80     LOG(DEBUG) << "Successfully SetMacAddress.";
81     return true;
82 }
83 
getOrCreateRandomMacAddress()84 std::array<uint8_t, 6> WifiIfaceUtil::getOrCreateRandomMacAddress() {
85     if (random_mac_address_) {
86         return *random_mac_address_.get();
87     }
88     random_mac_address_ =
89         std::make_unique<std::array<uint8_t, 6>>(createRandomMacAddress());
90     return *random_mac_address_.get();
91 }
92 
registerIfaceEventHandlers(const std::string & iface_name,IfaceEventHandlers handlers)93 void WifiIfaceUtil::registerIfaceEventHandlers(const std::string& iface_name,
94                                                IfaceEventHandlers handlers) {
95     event_handlers_map_[iface_name] = handlers;
96 }
97 
unregisterIfaceEventHandlers(const std::string & iface_name)98 void WifiIfaceUtil::unregisterIfaceEventHandlers(
99     const std::string& iface_name) {
100     event_handlers_map_.erase(iface_name);
101 }
102 
createRandomMacAddress()103 std::array<uint8_t, 6> WifiIfaceUtil::createRandomMacAddress() {
104     std::array<uint8_t, 6> address = {};
105     std::random_device rd;
106     std::default_random_engine engine(rd());
107     std::uniform_int_distribution<uint8_t> dist(
108         std::numeric_limits<uint8_t>::min(),
109         std::numeric_limits<uint8_t>::max());
110     for (size_t i = 0; i < address.size(); i++) {
111         address[i] = dist(engine);
112     }
113     // Set the local bit and clear the multicast bit.
114     address[0] |= kMacAddressLocallyAssignedMask;
115     address[0] &= ~kMacAddressMulticastMask;
116     return address;
117 }
118 
setUpState(const std::string & iface_name,bool request_up)119 bool WifiIfaceUtil::setUpState(const std::string& iface_name, bool request_up) {
120     if (!iface_tool_.lock()->SetUpState(iface_name.c_str(), request_up)) {
121         LOG(ERROR) << "SetUpState to " << request_up << " failed";
122         return false;
123     }
124     return true;
125 }
126 
ifNameToIndex(const std::string & iface_name)127 unsigned WifiIfaceUtil::ifNameToIndex(const std::string& iface_name) {
128     return if_nametoindex(iface_name.c_str());
129 }
130 }  // namespace iface_util
131 }  // namespace implementation
132 }  // namespace V1_4
133 }  // namespace wifi
134 }  // namespace hardware
135 }  // namespace android
136