1 /*
2  * Copyright (C) 2021 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 "ServiceManagerHost.h"
18 
19 #include <android-base/parseint.h>
20 #include <android-base/strings.h>
21 #include <binder/IServiceManager.h>
22 #include <binder/RpcSession.h>
23 
24 #include "UtilsHost.h"
25 
26 namespace android {
27 
28 namespace {
29 
30 const void* kDeviceServiceExtraId = "DeviceServiceExtra";
31 
32 // Parse stdout of program execution to string. If any error, return 0.
parsePortNumber(const std::string & out,const std::string & what)33 unsigned int parsePortNumber(const std::string& out, const std::string& what) {
34     auto trimmed = android::base::Trim(out);
35     unsigned int port = 0;
36     if (!android::base::ParseUint(trimmed, &port)) {
37         int savedErrno = errno;
38         ALOGE("%s is not a valid %s: %s", trimmed.c_str(), what.c_str(), strerror(savedErrno));
39         return 0;
40     }
41     if (port == 0) {
42         ALOGE("0 is not a valid %s", what.c_str());
43         return 0; // explicitly
44     }
45     return port;
46 }
47 
48 // RAII object for adb forwarding
49 class AdbForwarder {
50 public:
51     AdbForwarder() = default;
52     static std::optional<AdbForwarder> forward(unsigned int devicePort);
AdbForwarder(AdbForwarder && other)53     AdbForwarder(AdbForwarder&& other) noexcept { (*this) = std::move(other); }
54     AdbForwarder& operator=(AdbForwarder&&) noexcept;
55     ~AdbForwarder();
hostPort() const56     [[nodiscard]] const std::optional<unsigned int>& hostPort() const { return mPort; }
57 
58 private:
59     AdbForwarder(const AdbForwarder&) = delete;
60     void operator=(const AdbForwarder&) = delete;
AdbForwarder(unsigned int port)61     explicit AdbForwarder(unsigned int port) : mPort(port) {}
62     std::optional<unsigned int> mPort;
63 };
forward(unsigned int devicePort)64 std::optional<AdbForwarder> AdbForwarder::forward(unsigned int devicePort) {
65     auto result =
66             execute({"adb", "forward", "tcp:0", "tcp:" + std::to_string(devicePort)}, nullptr);
67     if (!result.has_value()) {
68         ALOGE("Unable to run `adb forward tcp:0 tcp:%d`", devicePort);
69         return std::nullopt;
70     }
71     // Must end with exit code 0 (`has_value() && value() == 0`)
72     if (result->exitCode.value_or(1) != 0) {
73         ALOGE("Unable to run `adb forward tcp:0 tcp:%d`, command exits with %s", devicePort,
74               result->toString().c_str());
75         return std::nullopt;
76     }
77     if (!result->stderrStr.empty()) {
78         LOG_HOST("`adb forward tcp:0 tcp:%d` writes to stderr: %s", devicePort,
79                  result->stderrStr.c_str());
80     }
81 
82     unsigned int hostPort = parsePortNumber(result->stdoutStr, "host port");
83     if (hostPort == 0) return std::nullopt;
84 
85     return AdbForwarder(hostPort);
86 }
87 
operator =(AdbForwarder && other)88 AdbForwarder& AdbForwarder::operator=(AdbForwarder&& other) noexcept {
89     std::swap(mPort, other.mPort);
90     return *this;
91 }
92 
~AdbForwarder()93 AdbForwarder::~AdbForwarder() {
94     if (!mPort.has_value()) return;
95 
96     auto result = execute({"adb", "forward", "--remove", "tcp:" + std::to_string(*mPort)}, nullptr);
97     if (!result.has_value()) {
98         ALOGE("Unable to run `adb forward --remove tcp:%d`", *mPort);
99         return;
100     }
101     // Must end with exit code 0 (`has_value() && value() == 0`)
102     if (result->exitCode.value_or(1) != 0) {
103         ALOGE("Unable to run `adb forward --remove tcp:%d`, command exits with %s", *mPort,
104               result->toString().c_str());
105         return;
106     }
107     if (!result->stderrStr.empty()) {
108         LOG_HOST("`adb forward --remove tcp:%d` writes to stderr: %s", *mPort,
109                  result->stderrStr.c_str());
110     }
111 
112     LOG_HOST("Successfully run `adb forward --remove tcp:%d`", *mPort);
113 }
114 
cleanupCommandResult(const void * id,void * obj,void *)115 void cleanupCommandResult(const void* id, void* obj, void* /* cookie */) {
116     LOG_ALWAYS_FATAL_IF(id != kDeviceServiceExtraId,
117                         "cleanupCommandResult invoked with mismatched ID %p, "
118                         "expected %p",
119                         id, kDeviceServiceExtraId);
120     auto ptr = static_cast<CommandResult*>(obj);
121     delete ptr;
122 }
123 
124 } // namespace
125 
getDeviceService(std::vector<std::string> && serviceDispatcherArgs,const RpcDelegateServiceManagerOptions & options)126 sp<IBinder> getDeviceService(std::vector<std::string>&& serviceDispatcherArgs,
127                              const RpcDelegateServiceManagerOptions& options) {
128     std::vector<std::string> prefix{"adb", "shell", "servicedispatcher"};
129     serviceDispatcherArgs.insert(serviceDispatcherArgs.begin(), prefix.begin(), prefix.end());
130 
131     auto result = execute(std::move(serviceDispatcherArgs), &CommandResult::stdoutEndsWithNewLine);
132     if (!result.has_value()) {
133         return nullptr;
134     }
135 
136     // `servicedispatcher` process must be alive to keep the port open.
137     if (result->exitCode.has_value()) {
138         ALOGE("Command exits with: %s", result->toString().c_str());
139         return nullptr;
140     }
141     if (!result->stderrStr.empty()) {
142         LOG_HOST("servicedispatcher writes to stderr: %s", result->stderrStr.c_str());
143     }
144 
145     if (!result->stdoutEndsWithNewLine()) {
146         ALOGE("Unexpected command result: %s", result->toString().c_str());
147         return nullptr;
148     }
149 
150     unsigned int devicePort = parsePortNumber(result->stdoutStr, "device port");
151     if (devicePort == 0) return nullptr;
152 
153     auto forwardResult = AdbForwarder::forward(devicePort);
154     if (!forwardResult.has_value()) {
155         return nullptr;
156     }
157     LOG_ALWAYS_FATAL_IF(!forwardResult->hostPort().has_value());
158 
159     auto rpcSession = RpcSession::make();
160     if (options.maxOutgoingConnections.has_value()) {
161         rpcSession->setMaxOutgoingConnections(*options.maxOutgoingConnections);
162     }
163 
164     if (status_t status = rpcSession->setupInetClient("127.0.0.1", *forwardResult->hostPort());
165         status != OK) {
166         ALOGE("Unable to set up inet client on host port %u: %s", *forwardResult->hostPort(),
167               statusToString(status).c_str());
168         return nullptr;
169     }
170     auto binder = rpcSession->getRootObject();
171     if (binder == nullptr) {
172         ALOGE("RpcSession::getRootObject returns nullptr");
173         return nullptr;
174     }
175 
176     LOG_ALWAYS_FATAL_IF(
177             nullptr !=
178             binder->attachObject(kDeviceServiceExtraId,
179                                  static_cast<void*>(new CommandResult(std::move(*result))), nullptr,
180                                  &cleanupCommandResult));
181     return binder;
182 }
183 
184 } // namespace android
185