C++ IPCThreadState类代码示例

void BpBinder::sendObituary()
{
    ALOGV("Sending obituary for proxy %p handle %d, mObitsSent=%s\n",
        this, mHandle, mObitsSent ? "true" : "false");

    mAlive = 0;
    if (mObitsSent) return;

    mLock.lock();
    Vector<Obituary>* obits = mObituaries;
    if(obits != NULL) {
        ALOGV("Clearing sent death notification: %p handle %d\n", this, mHandle);
        IPCThreadState* self = IPCThreadState::self();
        self->clearDeathNotification(mHandle, this);
        self->flushCommands();
        mObituaries = NULL;
    }
    mObitsSent = 1;
    mLock.unlock();

    ALOGV("Reporting death of proxy %p for %d recipients\n",
        this, obits ? obits->size() : 0);

    if (obits != NULL) {
        const size_t N = obits->size();
        for (size_t i=0; i<N; i++) {
            reportOneDeath(obits->itemAt(i));
        }

        delete obits;
    }
}

static void android_os_Parcel_enforceInterface(JNIEnv* env, jclass clazz, jlong nativePtr, jstring name)
{
    Parcel* parcel = reinterpret_cast<Parcel*>(nativePtr);
    if (parcel != NULL) {
        const jchar* str = env->GetStringCritical(name, 0);
        if (str) {
            IPCThreadState* threadState = IPCThreadState::self();
            const int32_t oldPolicy = threadState->getStrictModePolicy();
            const bool isValid = parcel->enforceInterface(
                String16(reinterpret_cast<const char16_t*>(str),
                         env->GetStringLength(name)),
                threadState);
            env->ReleaseStringCritical(name, str);
            if (isValid) {
                const int32_t newPolicy = threadState->getStrictModePolicy();
                if (oldPolicy != newPolicy) {
                    // Need to keep the Java-level thread-local strict
                    // mode policy in sync for the libcore
                    // enforcements, which involves an upcall back
                    // into Java.  (We can't modify the
                    // Parcel.enforceInterface signature, as it's
                    // pseudo-public, and used via AIDL
                    // auto-generation...)
                    set_dalvik_blockguard_policy(env, newPolicy);
                }
                return;     // everything was correct -> return silently
            }
        }
    }

    // all error conditions wind up here
    jniThrowException(env, "java/lang/SecurityException",
            "Binder invocation to an incorrect interface");
}

status_t FakeSurfaceComposer::onTransact(uint32_t code, const Parcel& data,
                                         Parcel* reply, uint32_t flags)
{
    switch (code) {
        case CREATE_CONNECTION:
        case CREATE_DISPLAY:
        case SET_TRANSACTION_STATE:
        case CAPTURE_SCREEN:
        {
            // codes that require permission check
            IPCThreadState* ipc = IPCThreadState::self();
            const int pid = ipc->getCallingPid();
            const int uid = ipc->getCallingUid();
            // Accept request only when uid is root.
            if (uid != AID_ROOT) {
                ALOGE("Permission Denial: "
                        "can't access SurfaceFlinger pid=%d, uid=%d", pid, uid);
                return PERMISSION_DENIED;
            }
            break;
        }
    }

    return BnSurfaceComposer::onTransact(code, data, reply, flags);
}

bool Permission::checkCalling() const
{
    IPCThreadState* ipcState = IPCThreadState::self();
    pid_t pid = ipcState->getCallingPid();
    uid_t uid = ipcState->getCallingUid();
    return doCheckPermission(pid, uid);
}

static bool isProtectedCallAllowed() {
    // M: migration these from ICS
    // TODO
    // Following implementation is just for reference.
    // Each OEM manufacturer should implement/replace with their own solutions.
    bool result = false;

    IPCThreadState* ipcState = IPCThreadState::self();
    uid_t uid = ipcState->getCallingUid();

    for (unsigned int i = 0; i < trustedUids.size(); ++i) {
        if (trustedUids[i] == uid) {
            result = true;
            break;
        }
    }

    // M:
    // for OMA DRM v1 implementation
    // if can't authorize the process by UID, then check the process name.
    if (!result) {
        pid_t pid = ipcState->getCallingPid();
        result = DrmTrustedClient::IsDrmTrustedClient(DrmMtkUtil::getProcessName(pid));
    }

    return result;
}

status_t BpBinder::linkToDeath(
    const sp<DeathRecipient>& recipient, void* cookie, uint32_t flags)
{
    Obituary ob;
    ob.recipient = recipient;
    ob.cookie = cookie;
    ob.flags = flags;

    LOG_ALWAYS_FATAL_IF(recipient == NULL,
                        "linkToDeath(): recipient must be non-NULL");

    {
        AutoMutex _l(mLock);

        if (!mObitsSent) {
            if (!mObituaries) {
                mObituaries = new Vector<Obituary>;
                if (!mObituaries) {
                    return NO_MEMORY;
                }
                ALOGV("Requesting death notification: %p handle %d\n", this, mHandle);
                getWeakRefs()->incWeak(this);
                IPCThreadState* self = IPCThreadState::self();
                self->requestDeathNotification(mHandle, this);
                self->flushCommands();
            }
            ssize_t res = mObituaries->add(ob);
            return res >= (ssize_t)NO_ERROR ? (status_t)NO_ERROR : res;
        }
    }

    return DEAD_OBJECT;
}

status_t BpBinder::unlinkToDeath(
    const wp<DeathRecipient>& recipient, void* cookie, uint32_t flags,
    wp<DeathRecipient>* outRecipient)
{
    AutoMutex _l(mLock);

    if (mObitsSent) {
        return DEAD_OBJECT;
    }

    const size_t N = mObituaries ? mObituaries->size() : 0;
    for (size_t i=0; i<N; i++) {
        const Obituary& obit = mObituaries->itemAt(i);
        if ((obit.recipient == recipient
                    || (recipient == NULL && obit.cookie == cookie))
                && obit.flags == flags) {
            const uint32_t allFlags = obit.flags|flags;
            if (outRecipient != NULL) {
                *outRecipient = mObituaries->itemAt(i).recipient;
            }
            mObituaries->removeAt(i);
            if (mObituaries->size() == 0) {
                ALOGV("Clearing death notification: %p handle %d\n", this, mHandle);
                IPCThreadState* self = IPCThreadState::self();
                self->clearDeathNotification(mHandle, this);
                self->flushCommands();
                delete mObituaries;
                mObituaries = NULL;
            }
            return NO_ERROR;
        }
    }

    return NAME_NOT_FOUND;
}

sp<IBinder> ProcessState::getContextObject(const String16& name, const sp<IBinder>& caller)
{
    mLock.lock();
    sp<IBinder> object(
        mContexts.indexOfKey(name) >= 0 ? mContexts.valueFor(name) : NULL);
    mLock.unlock();
    
    //printf("Getting context object %s for %p\n", String8(name).string(), caller.get());
    
    if (object != NULL) return object;

    // Don't attempt to retrieve contexts if we manage them
    if (mManagesContexts) {
        ALOGE("getContextObject(%s) failed, but we manage the contexts!\n",
            String8(name).string());
        return NULL;
    }
    
    IPCThreadState* ipc = IPCThreadState::self();
    {
        Parcel data, reply;
        // no interface token on this magic transaction
        data.writeString16(name);
        data.writeStrongBinder(caller);
        status_t result = ipc->transact(0 /*magic*/, 0, data, &reply, 0);
        if (result == NO_ERROR) {
            object = reply.readStrongBinder();
        }
    }
    
    ipc->flushCommands();
    
    if (object != NULL) setContextObject(object, name);
    return object;
}

status_t BnQService::onTransact(
    uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
{
    // IPC should be from mediaserver only
    IPCThreadState* ipc = IPCThreadState::self();
    const int callerPid = ipc->getCallingPid();
    const int callerUid = ipc->getCallingUid();

    const bool permission = (callerUid == AID_MEDIA);

    switch(code) {
        case CONNECT: {
            CHECK_INTERFACE(IQService, data, reply);

            sp<IQClient> client =
                interface_cast<IQClient>(data.readStrongBinder());
            connect(client);
            return NO_ERROR;
        } break;
		case SETMEM: {
            CHECK_INTERFACE(IQService, data, reply);

            sp<IMemory> sharedBuffer =
                interface_cast<IMemory>(data.readStrongBinder());
            setMemory(sharedBuffer);
            return NO_ERROR;
        } break;
        default:
            return BBinder::onTransact(code, data, reply, flags);
    }
}

bool checkCallingPermission(const String16& permission, int32_t* outPid, int32_t* outUid)
{
    IPCThreadState* ipcState = IPCThreadState::self();
    pid_t pid = ipcState->getCallingPid();
    uid_t uid = ipcState->getCallingUid();
    if (outPid) *outPid = pid;
    if (outUid) *outUid = uid;
    return checkPermission(permission, pid, uid);
}

    virtual int enroll(uint32_t uid,
            const uint8_t *current_password_handle, uint32_t current_password_handle_length,
            const uint8_t *current_password, uint32_t current_password_length,
            const uint8_t *desired_password, uint32_t desired_password_length,
            uint8_t **enrolled_password_handle, uint32_t *enrolled_password_handle_length) {
        IPCThreadState* ipc = IPCThreadState::self();
        const int calling_pid = ipc->getCallingPid();
        const int calling_uid = ipc->getCallingUid();
        if (!PermissionCache::checkPermission(KEYGUARD_PERMISSION, calling_pid, calling_uid)) {
            return PERMISSION_DENIED;
        }

        // need a desired password to enroll
        if (desired_password_length == 0) return -EINVAL;

        int ret;
        if (device) {
            const gatekeeper::password_handle_t *handle =
                    reinterpret_cast<const gatekeeper::password_handle_t *>(current_password_handle);

            if (handle != NULL && handle->version != 0 && !handle->hardware_backed) {
                // handle is being re-enrolled from a software version. HAL probably won't accept
                // the handle as valid, so we nullify it and enroll from scratch
                current_password_handle = NULL;
                current_password_handle_length = 0;
                current_password = NULL;
                current_password_length = 0;
            }

            ret = device->enroll(device, uid, current_password_handle, current_password_handle_length,
                    current_password, current_password_length,
                    desired_password, desired_password_length,
                    enrolled_password_handle, enrolled_password_handle_length);
        } else {
            ret = soft_device->enroll(uid,
                    current_password_handle, current_password_handle_length,
                    current_password, current_password_length,
                    desired_password, desired_password_length,
                    enrolled_password_handle, enrolled_password_handle_length);
        }

        if (ret == 0) {
            gatekeeper::password_handle_t *handle =
                    reinterpret_cast<gatekeeper::password_handle_t *>(*enrolled_password_handle);
            store_sid(uid, handle->user_id);
            bool rr;

            // immediately verify this password so we don't ask the user to enter it again
            // if they just created it.
            verify(uid, *enrolled_password_handle, sizeof(password_handle_t), desired_password,
                    desired_password_length, &rr);
        }

        return ret;
    }

status_t BatteryPropertiesRegistrar::dump(int fd, const Vector<String16>& /*args*/) {
    IPCThreadState* self = IPCThreadState::self();
    const int pid = self->getCallingPid();
    const int uid = self->getCallingUid();
    if ((uid != AID_SHELL) &&
        !PermissionCache::checkPermission(
                String16("android.permission.DUMP"), pid, uid))
        return PERMISSION_DENIED;

    healthd_dump_battery_state(fd);
    return OK;
}

    virtual void clearSecureUserId(uint32_t uid) {
        IPCThreadState* ipc = IPCThreadState::self();
        const int calling_pid = ipc->getCallingPid();
        const int calling_uid = ipc->getCallingUid();
        if (!PermissionCache::checkPermission(KEYGUARD_PERMISSION, calling_pid, calling_uid)) {
            ALOGE("%s: permission denied for [%d:%d]", __func__, calling_pid, calling_uid);
            return;
        }
        clear_sid(uid);

        if (device != NULL && device->delete_user != NULL) {
            device->delete_user(device, uid);
        }
    }

status_t BnMediaAnalyticsService::onTransact(
    uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
{


    // get calling pid/tid
    IPCThreadState *ipc = IPCThreadState::self();
    int clientPid = ipc->getCallingPid();
    // permission checking

    if(DEBUGGING_FLOW) {
        ALOGD("running in service, code %d, pid %d; called from pid %d",
            code, getpid(), clientPid);
    }

    switch (code) {

        case GENERATE_UNIQUE_SESSIONID: {
            CHECK_INTERFACE(IMediaAnalyticsService, data, reply);

            MediaAnalyticsItem::SessionID_t sessionid = generateUniqueSessionID();
            reply->writeInt64(sessionid);

            return NO_ERROR;
        } break;

        case SUBMIT_ITEM: {
            CHECK_INTERFACE(IMediaAnalyticsService, data, reply);

            bool forcenew;
            MediaAnalyticsItem *item = new MediaAnalyticsItem;

            data.readBool(&forcenew);
            item->readFromParcel(data);

            item->setPid(clientPid);

            // submit() takes over ownership of 'item'
            MediaAnalyticsItem::SessionID_t sessionid = submit(item, forcenew);
            reply->writeInt64(sessionid);

            return NO_ERROR;
        } break;

        default:
            return BBinder::onTransact(code, data, reply, flags);
    }
}

BpBinder::~BpBinder()
{
    ALOGV("Destroying BpBinder %p handle %d\n", this, mHandle);

    IPCThreadState* ipc = IPCThreadState::self();

    if (mTrackedUid >= 0) {
        AutoMutex _l(sTrackingLock);
        uint32_t trackedValue = sTrackingMap[mTrackedUid];
        if (CC_UNLIKELY((trackedValue & COUNTING_VALUE_MASK) == 0)) {
            ALOGE("Unexpected Binder Proxy tracking decrement in %p handle %d\n", this, mHandle);
        } else {
            if (CC_UNLIKELY(
                (trackedValue & LIMIT_REACHED_MASK) &&
                ((trackedValue & COUNTING_VALUE_MASK) <= sBinderProxyCountLowWatermark)
                )) {
                ALOGI("Limit reached bit reset for uid %d (fewer than %d proxies from uid %d held)",
                                   getuid(), mTrackedUid, sBinderProxyCountLowWatermark);
                sTrackingMap[mTrackedUid] &= ~LIMIT_REACHED_MASK;
            }
            if (--sTrackingMap[mTrackedUid] == 0) {
                sTrackingMap.erase(mTrackedUid);
            }
        }
    }

    mLock.lock();
    Vector<Obituary>* obits = mObituaries;
    if(obits != NULL) {
        if (ipc) ipc->clearDeathNotification(mHandle, this);
        mObituaries = NULL;
    }
    mLock.unlock();

    if (obits != NULL) {
        // XXX Should we tell any remaining DeathRecipient
        // objects that the last strong ref has gone away, so they
        // are no longer linked?
        delete obits;
    }

    if (ipc) {
        ipc->expungeHandle(mHandle, this);
        ipc->decWeakHandle(mHandle);
    }
}