Home | History | Annotate | Download | only in binder
      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 #include <utils/CallStack.h>
     27 
     28 #include <private/binder/Static.h>
     29 
     30 #include <unistd.h>
     31 
     32 namespace android {
     33 
     34 sp<IServiceManager> defaultServiceManager()
     35 {
     36     if (gDefaultServiceManager != NULL) return gDefaultServiceManager;
     37 
     38     {
     39         AutoMutex _l(gDefaultServiceManagerLock);
     40         while (gDefaultServiceManager == NULL) {
     41             gDefaultServiceManager = interface_cast<IServiceManager>(
     42                 ProcessState::self()->getContextObject(NULL));
     43             if (gDefaultServiceManager == NULL)
     44                 sleep(1);
     45         }
     46     }
     47 
     48     return gDefaultServiceManager;
     49 }
     50 
     51 bool checkCallingPermission(const String16& permission)
     52 {
     53     return checkCallingPermission(permission, NULL, NULL);
     54 }
     55 
     56 static String16 _permission("permission");
     57 
     58 
     59 bool checkCallingPermission(const String16& permission, int32_t* outPid, int32_t* outUid)
     60 {
     61     IPCThreadState* ipcState = IPCThreadState::self();
     62     pid_t pid = ipcState->getCallingPid();
     63     uid_t uid = ipcState->getCallingUid();
     64     if (outPid) *outPid = pid;
     65     if (outUid) *outUid = uid;
     66     return checkPermission(permission, pid, uid);
     67 }
     68 
     69 bool checkPermission(const String16& permission, pid_t pid, uid_t uid)
     70 {
     71     sp<IPermissionController> pc;
     72     gDefaultServiceManagerLock.lock();
     73     pc = gPermissionController;
     74     gDefaultServiceManagerLock.unlock();
     75 
     76     int64_t startTime = 0;
     77 
     78     while (true) {
     79         if (pc != NULL) {
     80             bool res = pc->checkPermission(permission, pid, uid);
     81             if (res) {
     82                 if (startTime != 0) {
     83                     ALOGI("Check passed after %d seconds for %s from uid=%d pid=%d",
     84                             (int)((uptimeMillis()-startTime)/1000),
     85                             String8(permission).string(), uid, pid);
     86                 }
     87                 return res;
     88             }
     89 
     90             // Is this a permission failure, or did the controller go away?
     91             if (IInterface::asBinder(pc)->isBinderAlive()) {
     92                 ALOGW("Permission failure: %s from uid=%d pid=%d",
     93                         String8(permission).string(), uid, pid);
     94                 return false;
     95             }
     96 
     97             // Object is dead!
     98             gDefaultServiceManagerLock.lock();
     99             if (gPermissionController == pc) {
    100                 gPermissionController = NULL;
    101             }
    102             gDefaultServiceManagerLock.unlock();
    103         }
    104 
    105         // Need to retrieve the permission controller.
    106         sp<IBinder> binder = defaultServiceManager()->checkService(_permission);
    107         if (binder == NULL) {
    108             // Wait for the permission controller to come back...
    109             if (startTime == 0) {
    110                 startTime = uptimeMillis();
    111                 ALOGI("Waiting to check permission %s from uid=%d pid=%d",
    112                         String8(permission).string(), uid, pid);
    113             }
    114             sleep(1);
    115         } else {
    116             pc = interface_cast<IPermissionController>(binder);
    117             // Install the new permission controller, and try again.
    118             gDefaultServiceManagerLock.lock();
    119             gPermissionController = pc;
    120             gDefaultServiceManagerLock.unlock();
    121         }
    122     }
    123 }
    124 
    125 // ----------------------------------------------------------------------
    126 
    127 class BpServiceManager : public BpInterface<IServiceManager>
    128 {
    129 public:
    130     explicit BpServiceManager(const sp<IBinder>& impl)
    131         : BpInterface<IServiceManager>(impl)
    132     {
    133     }
    134 
    135     virtual sp<IBinder> getService(const String16& name) const
    136     {
    137         unsigned n;
    138         for (n = 0; n < 5; n++){
    139             if (n > 0) {
    140                 if (!strcmp(ProcessState::self()->getDriverName().c_str(), "/dev/vndbinder")) {
    141                     ALOGI("Waiting for vendor service %s...", String8(name).string());
    142                     CallStack stack(LOG_TAG);
    143                 } else {
    144                     ALOGI("Waiting for service %s...", String8(name).string());
    145                 }
    146                 sleep(1);
    147             }
    148             sp<IBinder> svc = checkService(name);
    149             if (svc != NULL) return svc;
    150         }
    151         return NULL;
    152     }
    153 
    154     virtual sp<IBinder> checkService( const String16& name) const
    155     {
    156         Parcel data, reply;
    157         data.writeInterfaceToken(IServiceManager::getInterfaceDescriptor());
    158         data.writeString16(name);
    159         remote()->transact(CHECK_SERVICE_TRANSACTION, data, &reply);
    160         return reply.readStrongBinder();
    161     }
    162 
    163     virtual status_t addService(const String16& name, const sp<IBinder>& service,
    164             bool allowIsolated)
    165     {
    166         Parcel data, reply;
    167         data.writeInterfaceToken(IServiceManager::getInterfaceDescriptor());
    168         data.writeString16(name);
    169         data.writeStrongBinder(service);
    170         data.writeInt32(allowIsolated ? 1 : 0);
    171         status_t err = remote()->transact(ADD_SERVICE_TRANSACTION, data, &reply);
    172         return err == NO_ERROR ? reply.readExceptionCode() : err;
    173     }
    174 
    175     virtual Vector<String16> listServices()
    176     {
    177         Vector<String16> res;
    178         int n = 0;
    179 
    180         for (;;) {
    181             Parcel data, reply;
    182             data.writeInterfaceToken(IServiceManager::getInterfaceDescriptor());
    183             data.writeInt32(n++);
    184             status_t err = remote()->transact(LIST_SERVICES_TRANSACTION, data, &reply);
    185             if (err != NO_ERROR)
    186                 break;
    187             res.add(reply.readString16());
    188         }
    189         return res;
    190     }
    191 };
    192 
    193 IMPLEMENT_META_INTERFACE(ServiceManager, "android.os.IServiceManager");
    194 
    195 }; // namespace android
    196