1/*
2 * Copyright (C) 2005 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 "ServiceManager"
18
19#include <binder/IServiceManager.h>
20
21#include <utils/Log.h>
22#include <binder/IPCThreadState.h>
23#include <binder/Parcel.h>
24#include <utils/String8.h>
25#include <utils/SystemClock.h>
26
27#include <private/binder/Static.h>
28
29#include <unistd.h>
30
31namespace android {
32
33sp<IServiceManager> defaultServiceManager()
34{
35    if (gDefaultServiceManager != NULL) return gDefaultServiceManager;
36
37    {
38        AutoMutex _l(gDefaultServiceManagerLock);
39        while (gDefaultServiceManager == NULL) {
40            gDefaultServiceManager = interface_cast<IServiceManager>(
41                ProcessState::self()->getContextObject(NULL));
42            if (gDefaultServiceManager == NULL)
43                sleep(1);
44        }
45    }
46
47    return gDefaultServiceManager;
48}
49
50bool checkCallingPermission(const String16& permission)
51{
52    return checkCallingPermission(permission, NULL, NULL);
53}
54
55static String16 _permission("permission");
56
57
58bool checkCallingPermission(const String16& permission, int32_t* outPid, int32_t* outUid)
59{
60    IPCThreadState* ipcState = IPCThreadState::self();
61    pid_t pid = ipcState->getCallingPid();
62    uid_t uid = ipcState->getCallingUid();
63    if (outPid) *outPid = pid;
64    if (outUid) *outUid = uid;
65    return checkPermission(permission, pid, uid);
66}
67
68bool checkPermission(const String16& permission, pid_t pid, uid_t uid)
69{
70#ifdef __BRILLO__
71    // Brillo doesn't currently run ActivityManager or support framework permissions.
72    return true;
73#endif
74
75    sp<IPermissionController> pc;
76    gDefaultServiceManagerLock.lock();
77    pc = gPermissionController;
78    gDefaultServiceManagerLock.unlock();
79
80    int64_t startTime = 0;
81
82    while (true) {
83        if (pc != NULL) {
84            bool res = pc->checkPermission(permission, pid, uid);
85            if (res) {
86                if (startTime != 0) {
87                    ALOGI("Check passed after %d seconds for %s from uid=%d pid=%d",
88                            (int)((uptimeMillis()-startTime)/1000),
89                            String8(permission).string(), uid, pid);
90                }
91                return res;
92            }
93
94            // Is this a permission failure, or did the controller go away?
95            if (IInterface::asBinder(pc)->isBinderAlive()) {
96                ALOGW("Permission failure: %s from uid=%d pid=%d",
97                        String8(permission).string(), uid, pid);
98                return false;
99            }
100
101            // Object is dead!
102            gDefaultServiceManagerLock.lock();
103            if (gPermissionController == pc) {
104                gPermissionController = NULL;
105            }
106            gDefaultServiceManagerLock.unlock();
107        }
108
109        // Need to retrieve the permission controller.
110        sp<IBinder> binder = defaultServiceManager()->checkService(_permission);
111        if (binder == NULL) {
112            // Wait for the permission controller to come back...
113            if (startTime == 0) {
114                startTime = uptimeMillis();
115                ALOGI("Waiting to check permission %s from uid=%d pid=%d",
116                        String8(permission).string(), uid, pid);
117            }
118            sleep(1);
119        } else {
120            pc = interface_cast<IPermissionController>(binder);
121            // Install the new permission controller, and try again.
122            gDefaultServiceManagerLock.lock();
123            gPermissionController = pc;
124            gDefaultServiceManagerLock.unlock();
125        }
126    }
127}
128
129// ----------------------------------------------------------------------
130
131class BpServiceManager : public BpInterface<IServiceManager>
132{
133public:
134    BpServiceManager(const sp<IBinder>& impl)
135        : BpInterface<IServiceManager>(impl)
136    {
137    }
138
139    virtual sp<IBinder> getService(const String16& name) const
140    {
141        unsigned n;
142        for (n = 0; n < 5; n++){
143            sp<IBinder> svc = checkService(name);
144            if (svc != NULL) return svc;
145            ALOGI("Waiting for service %s...\n", String8(name).string());
146            sleep(1);
147        }
148        return NULL;
149    }
150
151    virtual sp<IBinder> checkService( const String16& name) const
152    {
153        Parcel data, reply;
154        data.writeInterfaceToken(IServiceManager::getInterfaceDescriptor());
155        data.writeString16(name);
156        remote()->transact(CHECK_SERVICE_TRANSACTION, data, &reply);
157        return reply.readStrongBinder();
158    }
159
160    virtual status_t addService(const String16& name, const sp<IBinder>& service,
161            bool allowIsolated)
162    {
163        Parcel data, reply;
164        data.writeInterfaceToken(IServiceManager::getInterfaceDescriptor());
165        data.writeString16(name);
166        data.writeStrongBinder(service);
167        data.writeInt32(allowIsolated ? 1 : 0);
168        status_t err = remote()->transact(ADD_SERVICE_TRANSACTION, data, &reply);
169        return err == NO_ERROR ? reply.readExceptionCode() : err;
170    }
171
172    virtual Vector<String16> listServices()
173    {
174        Vector<String16> res;
175        int n = 0;
176
177        for (;;) {
178            Parcel data, reply;
179            data.writeInterfaceToken(IServiceManager::getInterfaceDescriptor());
180            data.writeInt32(n++);
181            status_t err = remote()->transact(LIST_SERVICES_TRANSACTION, data, &reply);
182            if (err != NO_ERROR)
183                break;
184            res.add(reply.readString16());
185        }
186        return res;
187    }
188};
189
190IMPLEMENT_META_INTERFACE(ServiceManager, "android.os.IServiceManager");
191
192}; // namespace android
193