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 <cstddef>
18 #include <iostream>
19 #include <limits>
20 #include <random>
21 
22 #include <android-base/logging.h>
23 #include <android-base/macros.h>
24 #include <private/android_filesystem_config.h>
25 
26 #undef NAN
27 #include "wifi_iface_util.h"
28 
29 namespace {
30 // Constants to set the local bit & clear the multicast bit.
31 constexpr uint8_t kMacAddressMulticastMask = 0x01;
32 constexpr uint8_t kMacAddressLocallyAssignedMask = 0x02;
33 }  // namespace
34 
35 namespace android {
36 namespace hardware {
37 namespace wifi {
38 namespace V1_3 {
39 namespace implementation {
40 namespace iface_util {
41 
WifiIfaceUtil(const std::weak_ptr<wifi_system::InterfaceTool> iface_tool)42 WifiIfaceUtil::WifiIfaceUtil(
43     const std::weak_ptr<wifi_system::InterfaceTool> iface_tool)
44     : iface_tool_(iface_tool),
45       random_mac_address_(nullptr),
46       event_handlers_map_() {}
47 
getFactoryMacAddress(const std::string & iface_name)48 std::array<uint8_t, 6> WifiIfaceUtil::getFactoryMacAddress(
49     const std::string& iface_name) {
50     return iface_tool_.lock()->GetFactoryMacAddress(iface_name.c_str());
51 }
52 
setMacAddress(const std::string & iface_name,const std::array<uint8_t,6> & mac)53 bool WifiIfaceUtil::setMacAddress(const std::string& iface_name,
54                                   const std::array<uint8_t, 6>& mac) {
55     if (!iface_tool_.lock()->SetUpState(iface_name.c_str(), false)) {
56         LOG(ERROR) << "SetUpState(false) failed.";
57         return false;
58     }
59     if (!iface_tool_.lock()->SetMacAddress(iface_name.c_str(), mac)) {
60         LOG(ERROR) << "SetMacAddress failed.";
61         return false;
62     }
63     if (!iface_tool_.lock()->SetUpState(iface_name.c_str(), true)) {
64         LOG(ERROR) << "SetUpState(true) failed.";
65         return false;
66     }
67     IfaceEventHandlers event_handlers = {};
68     const auto it = event_handlers_map_.find(iface_name);
69     if (it != event_handlers_map_.end()) {
70         event_handlers = it->second;
71     }
72     if (event_handlers.on_state_toggle_off_on != nullptr) {
73         event_handlers.on_state_toggle_off_on(iface_name);
74     }
75     LOG(DEBUG) << "Successfully SetMacAddress.";
76     return true;
77 }
78 
getOrCreateRandomMacAddress()79 std::array<uint8_t, 6> WifiIfaceUtil::getOrCreateRandomMacAddress() {
80     if (random_mac_address_) {
81         return *random_mac_address_.get();
82     }
83     random_mac_address_ =
84         std::make_unique<std::array<uint8_t, 6>>(createRandomMacAddress());
85     return *random_mac_address_.get();
86 }
87 
registerIfaceEventHandlers(const std::string & iface_name,IfaceEventHandlers handlers)88 void WifiIfaceUtil::registerIfaceEventHandlers(const std::string& iface_name,
89                                                IfaceEventHandlers handlers) {
90     event_handlers_map_[iface_name] = handlers;
91 }
92 
unregisterIfaceEventHandlers(const std::string & iface_name)93 void WifiIfaceUtil::unregisterIfaceEventHandlers(
94     const std::string& iface_name) {
95     event_handlers_map_.erase(iface_name);
96 }
97 
createRandomMacAddress()98 std::array<uint8_t, 6> WifiIfaceUtil::createRandomMacAddress() {
99     std::array<uint8_t, 6> address = {};
100     std::random_device rd;
101     std::default_random_engine engine(rd());
102     std::uniform_int_distribution<uint8_t> dist(
103         std::numeric_limits<uint8_t>::min(),
104         std::numeric_limits<uint8_t>::max());
105     for (size_t i = 0; i < address.size(); i++) {
106         address[i] = dist(engine);
107     }
108     // Set the local bit and clear the multicast bit.
109     address[0] |= kMacAddressLocallyAssignedMask;
110     address[0] &= ~kMacAddressMulticastMask;
111     return address;
112 }
113 }  // namespace iface_util
114 }  // namespace implementation
115 }  // namespace V1_3
116 }  // namespace wifi
117 }  // namespace hardware
118 }  // namespace android
119