1 /* 2 * Copyright (C) 2006 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 <unistd.h> 18 #include <android_runtime/ActivityManager.h> 19 #include <binder/IBinder.h> 20 #include <binder/IServiceManager.h> 21 #include <binder/Parcel.h> 22 #include <utils/String8.h> 23 24 namespace android { 25 26 const uint32_t OPEN_CONTENT_URI_TRANSACTION = IBinder::FIRST_CALL_TRANSACTION + 4; 27 28 // Perform ContentProvider.openFile() on the given URI, returning 29 // the resulting native file descriptor. Returns < 0 on error. 30 int openContentProviderFile(const String16& uri) 31 { 32 int fd = -1; 33 34 sp<IServiceManager> sm = defaultServiceManager(); 35 sp<IBinder> am = sm->getService(String16("activity")); 36 if (am != NULL) { 37 Parcel data, reply; 38 data.writeInterfaceToken(String16("android.app.IActivityManager")); 39 data.writeString16(uri); 40 status_t ret = am->transact(OPEN_CONTENT_URI_TRANSACTION, data, &reply); 41 if (ret == NO_ERROR) { 42 int32_t exceptionCode = reply.readExceptionCode(); 43 if (!exceptionCode) { 44 // Success is indicated here by a nonzero int followed by the fd; 45 // failure by a zero int with no data following. 46 if (reply.readInt32() != 0) { 47 fd = dup(reply.readFileDescriptor()); 48 } 49 } else { 50 // An exception was thrown back; fall through to return failure 51 LOGD("openContentUri(%s) caught exception %d\n", 52 String8(uri).string(), exceptionCode); 53 } 54 } 55 } 56 57 return fd; 58 } 59 60 } /* namespace android */ 61