ServiceManagement.cpp revision 705e5da46d6f6fa5a2177afe460304668bd9102c 
1/*
2 * Copyright (C) 2016 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#define LOG_TAG "ServiceManagement"
18
19#include <condition_variable>
20#include <dlfcn.h>
21#include <dirent.h>
22#include <unistd.h>
23
24#include <mutex>
25#include <regex>
26
27#include <hidl/HidlBinderSupport.h>
28#include <hidl/ServiceManagement.h>
29#include <hidl/Static.h>
30#include <hidl/Status.h>
31
32#include <android-base/logging.h>
33#include <hidl-util/FQName.h>
34#include <hidl-util/StringHelper.h>
35#include <hwbinder/IPCThreadState.h>
36#include <hwbinder/Parcel.h>
37
38#include <android/hidl/manager/1.0/IServiceManager.h>
39#include <android/hidl/manager/1.0/BpHwServiceManager.h>
40#include <android/hidl/manager/1.0/BnHwServiceManager.h>
41
42#define RE_COMPONENT    "[a-zA-Z_][a-zA-Z_0-9]*"
43#define RE_PATH         RE_COMPONENT "(?:[.]" RE_COMPONENT ")*"
44static const std::regex gLibraryFileNamePattern("(" RE_PATH "@[0-9]+[.][0-9]+)-impl(.*?).so");
45
46using android::hidl::manager::V1_0::IServiceManager;
47using android::hidl::manager::V1_0::IServiceNotification;
48using android::hidl::manager::V1_0::BpHwServiceManager;
49using android::hidl::manager::V1_0::BnHwServiceManager;
50
51namespace android {
52namespace hardware {
53
54sp<IServiceManager> defaultServiceManager() {
55
56    if (gDefaultServiceManager != NULL) return gDefaultServiceManager;
57    if (access("/dev/hwbinder", F_OK|R_OK|W_OK) != 0) {
58        // HwBinder not available on this device or not accessible to
59        // this process.
60        return nullptr;
61    }
62    {
63        AutoMutex _l(gDefaultServiceManagerLock);
64        while (gDefaultServiceManager == NULL) {
65            gDefaultServiceManager = fromBinder<IServiceManager, BpHwServiceManager, BnHwServiceManager>(
66                ProcessState::self()->getContextObject(NULL));
67            if (gDefaultServiceManager == NULL)
68                sleep(1);
69        }
70    }
71
72    return gDefaultServiceManager;
73}
74
75std::vector<std::string> search(const std::string &path,
76                              const std::string &prefix,
77                              const std::string &suffix) {
78    std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(path.c_str()), closedir);
79    if (!dir) return {};
80
81    std::vector<std::string> results{};
82
83    dirent* dp;
84    while ((dp = readdir(dir.get())) != nullptr) {
85        std::string name = dp->d_name;
86
87        if (StringHelper::StartsWith(name, prefix) &&
88                StringHelper::EndsWith(name, suffix)) {
89            results.push_back(name);
90        }
91    }
92
93    return results;
94}
95
96bool matchPackageName(const std::string &lib, std::string *matchedName) {
97    std::smatch match;
98    if (std::regex_match(lib, match, gLibraryFileNamePattern)) {
99        *matchedName = match.str(1) + "::I*";
100        return true;
101    }
102    return false;
103}
104
105static void registerReference(const hidl_string &interfaceName, const hidl_string &instanceName) {
106    sp<IServiceManager> binderizedManager = defaultServiceManager();
107    if (binderizedManager == nullptr) {
108        LOG(WARNING) << "Could not registerReference for "
109                     << interfaceName << "/" << instanceName
110                     << ": null binderized manager.";
111        return;
112    }
113    auto ret = binderizedManager->registerPassthroughClient(interfaceName, instanceName, getpid());
114    if (!ret.isOk()) {
115        LOG(WARNING) << "Could not registerReference for "
116                     << interfaceName << "/" << instanceName
117                     << ": " << ret.description();
118    }
119    LOG(VERBOSE) << "Successfully registerReference for "
120                 << interfaceName << "/" << instanceName;
121}
122
123struct PassthroughServiceManager : IServiceManager {
124    Return<sp<IBase>> get(const hidl_string& fqName,
125                     const hidl_string& name) override {
126        const FQName iface(fqName);
127
128        if (!iface.isValid() ||
129            !iface.isFullyQualified() ||
130            iface.isIdentifier()) {
131            LOG(ERROR) << "Invalid interface name passthrough lookup: " << fqName;
132            return nullptr;
133        }
134
135        const std::string prefix = iface.getPackageAndVersion().string() + "-impl";
136        const std::string sym = "HIDL_FETCH_" + iface.name();
137
138        const int dlMode = RTLD_LAZY;
139        void *handle = nullptr;
140
141        // TODO: lookup in VINTF instead
142        // TODO(b/34135607): Remove HAL_LIBRARY_PATH_SYSTEM
143
144        dlerror(); // clear
145
146        for (const std::string &path : {
147            HAL_LIBRARY_PATH_ODM, HAL_LIBRARY_PATH_VENDOR, HAL_LIBRARY_PATH_SYSTEM
148        }) {
149            std::vector<std::string> libs = search(path, prefix, ".so");
150
151            for (const std::string &lib : libs) {
152                const std::string fullPath = path + lib;
153
154                handle = dlopen(fullPath.c_str(), dlMode);
155                if (handle == nullptr) {
156                    const char* error = dlerror();
157                    LOG(ERROR) << "Failed to dlopen " << lib << ": "
158                               << (error == nullptr ? "unknown error" : error);
159                    continue;
160                }
161
162                IBase* (*generator)(const char* name);
163                *(void **)(&generator) = dlsym(handle, sym.c_str());
164                if(!generator) {
165                    const char* error = dlerror();
166                    LOG(ERROR) << "Passthrough lookup opened " << lib
167                               << " but could not find symbol " << sym << ": "
168                               << (error == nullptr ? "unknown error" : error);
169                    dlclose(handle);
170                    continue;
171                }
172
173                IBase *interface = (*generator)(name);
174
175                if (interface == nullptr) {
176                    dlclose(handle);
177                    continue; // this module doesn't provide this instance name
178                }
179
180                registerReference(fqName, name);
181
182                return interface;
183            }
184        }
185
186        return nullptr;
187    }
188
189    Return<bool> add(const hidl_vec<hidl_string>& /* interfaceChain */,
190                     const hidl_string& /* name */,
191                     const sp<IBase>& /* service */) override {
192        LOG(FATAL) << "Cannot register services with passthrough service manager.";
193        return false;
194    }
195
196    Return<void> list(list_cb /* _hidl_cb */) override {
197        LOG(FATAL) << "Cannot list services with passthrough service manager.";
198        return Void();
199    }
200    Return<void> listByInterface(const hidl_string& /* fqInstanceName */,
201                                 listByInterface_cb /* _hidl_cb */) override {
202        // TODO: add this functionality
203        LOG(FATAL) << "Cannot list services with passthrough service manager.";
204        return Void();
205    }
206
207    Return<bool> registerForNotifications(const hidl_string& /* fqName */,
208                                          const hidl_string& /* name */,
209                                          const sp<IServiceNotification>& /* callback */) override {
210        // This makes no sense.
211        LOG(FATAL) << "Cannot register for notifications with passthrough service manager.";
212        return false;
213    }
214
215    Return<void> debugDump(debugDump_cb _hidl_cb) override {
216        using Arch = ::android::hidl::base::V1_0::DebugInfo::Architecture;
217        static std::vector<std::pair<Arch, std::vector<const char *>>> sAllPaths{
218            {Arch::IS_64BIT, {HAL_LIBRARY_PATH_ODM_64BIT,
219                                      HAL_LIBRARY_PATH_VENDOR_64BIT,
220                                      HAL_LIBRARY_PATH_SYSTEM_64BIT}},
221            {Arch::IS_32BIT, {HAL_LIBRARY_PATH_ODM_32BIT,
222                                      HAL_LIBRARY_PATH_VENDOR_32BIT,
223                                      HAL_LIBRARY_PATH_SYSTEM_32BIT}}
224        };
225        std::vector<InstanceDebugInfo> vec;
226        for (const auto &pair : sAllPaths) {
227            Arch arch = pair.first;
228            for (const auto &path : pair.second) {
229                std::vector<std::string> libs = search(path, "", ".so");
230                for (const std::string &lib : libs) {
231                    std::string matchedName;
232                    if (matchPackageName(lib, &matchedName)) {
233                        vec.push_back({
234                            .interfaceName = matchedName,
235                            .instanceName = "*",
236                            .clientPids = {},
237                            .arch = arch
238                        });
239                    }
240                }
241            }
242        }
243        _hidl_cb(vec);
244        return Void();
245    }
246
247    Return<void> registerPassthroughClient(const hidl_string &, const hidl_string &, int32_t) override {
248        // This makes no sense.
249        LOG(FATAL) << "Cannot call registerPassthroughClient on passthrough service manager. "
250                   << "Call it on defaultServiceManager() instead.";
251        return Void();
252    }
253
254};
255
256sp<IServiceManager> getPassthroughServiceManager() {
257    static sp<PassthroughServiceManager> manager(new PassthroughServiceManager());
258    return manager;
259}
260
261namespace details {
262
263struct Waiter : IServiceNotification {
264    Return<void> onRegistration(const hidl_string& /* fqName */,
265                                const hidl_string& /* name */,
266                                bool /* preexisting */) override {
267        std::unique_lock<std::mutex> lock(mMutex);
268        if (mRegistered) {
269            return Void();
270        }
271        mRegistered = true;
272        lock.unlock();
273
274        mCondition.notify_one();
275        return Void();
276    }
277
278    void wait() {
279        std::unique_lock<std::mutex> lock(mMutex);
280        mCondition.wait(lock, [this]{
281            return mRegistered;
282        });
283    }
284
285private:
286    std::mutex mMutex;
287    std::condition_variable mCondition;
288    bool mRegistered = false;
289};
290
291void waitForHwService(
292        const std::string &interface, const std::string &instanceName) {
293    const sp<IServiceManager> manager = defaultServiceManager();
294
295    if (manager == nullptr) {
296        LOG(ERROR) << "Could not get default service manager.";
297        return;
298    }
299
300    sp<Waiter> waiter = new Waiter();
301    Return<bool> ret = manager->registerForNotifications(interface, instanceName, waiter);
302
303    if (!ret.isOk()) {
304        LOG(ERROR) << "Transport error, " << ret.description()
305            << ", during notification registration for "
306            << interface << "/" << instanceName << ".";
307        return;
308    }
309
310    if (!ret) {
311        LOG(ERROR) << "Could not register for notifications for "
312            << interface << "/" << instanceName << ".";
313        return;
314    }
315
316    waiter->wait();
317}
318
319}; // namespace details
320
321}; // namespace hardware
322}; // namespace android
323