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 #pragma once 18 19 #include <utils/Errors.h> 20 #include <binder/Parcel.h> 21 #include <binder/ProcessState.h> 22 #include <utils/Vector.h> 23 24 #if defined(_WIN32) 25 typedef int uid_t; 26 #endif 27 28 // --------------------------------------------------------------------------- 29 namespace android { 30 31 class IPCThreadState 32 { 33 public: 34 using CallRestriction = ProcessState::CallRestriction; 35 36 static IPCThreadState* self(); 37 static IPCThreadState* selfOrNull(); // self(), but won't instantiate 38 39 // Freeze or unfreeze the binder interface to a specific process. When freezing, this method 40 // will block up to timeout_ms to process pending transactions directed to pid. Unfreeze 41 // is immediate. Transactions to processes frozen via this method won't be delivered and the 42 // driver will return BR_FROZEN_REPLY to the client sending them. After unfreeze, 43 // transactions will be delivered normally. 44 // 45 // pid: id for the process for which the binder interface is to be frozen 46 // enable: freeze (true) or unfreeze (false) 47 // timeout_ms: maximum time this function is allowed to block the caller waiting for pending 48 // binder transactions to be processed. 49 // 50 // returns: 0 in case of success, a value < 0 in case of error 51 static status_t freeze(pid_t pid, bool enabled, uint32_t timeout_ms); 52 53 // Provide information about the state of a frozen process 54 static status_t getProcessFreezeInfo(pid_t pid, bool *sync_received, 55 bool *async_received); 56 57 // TODO: Remove the above legacy duplicated function in next version 58 #ifndef __ANDROID_VNDK__ 59 static status_t getProcessFreezeInfo(pid_t pid, uint32_t *sync_received, 60 uint32_t *async_received); 61 #endif 62 63 sp<ProcessState> process(); 64 65 status_t clearLastError(); 66 67 /** 68 * Returns the PID of the process which has made the current binder 69 * call. If not in a binder call, this will return getpid. If the 70 * call is oneway, this will return 0. 71 */ 72 pid_t getCallingPid() const; 73 74 /** 75 * Returns the SELinux security identifier of the process which has 76 * made the current binder call. If not in a binder call this will 77 * return nullptr. If this isn't requested with 78 * Binder::setRequestingSid, it will also return nullptr. 79 * 80 * This can't be restored once it's cleared, and it does not return the 81 * context of the current process when not in a binder call. 82 */ 83 const char* getCallingSid() const; 84 85 /** 86 * Returns the UID of the process which has made the current binder 87 * call. If not in a binder call, this will return 0. 88 */ 89 uid_t getCallingUid() const; 90 91 void setStrictModePolicy(int32_t policy); 92 int32_t getStrictModePolicy() const; 93 94 // See Binder#setCallingWorkSourceUid in Binder.java. 95 int64_t setCallingWorkSourceUid(uid_t uid); 96 // Internal only. Use setCallingWorkSourceUid(uid) instead. 97 int64_t setCallingWorkSourceUidWithoutPropagation(uid_t uid); 98 // See Binder#getCallingWorkSourceUid in Binder.java. 99 uid_t getCallingWorkSourceUid() const; 100 // See Binder#clearCallingWorkSource in Binder.java. 101 int64_t clearCallingWorkSource(); 102 // See Binder#restoreCallingWorkSource in Binder.java. 103 void restoreCallingWorkSource(int64_t token); 104 void clearPropagateWorkSource(); 105 bool shouldPropagateWorkSource() const; 106 107 void setLastTransactionBinderFlags(int32_t flags); 108 int32_t getLastTransactionBinderFlags() const; 109 110 void setCallRestriction(CallRestriction restriction); 111 CallRestriction getCallRestriction() const; 112 113 int64_t clearCallingIdentity(); 114 // Restores PID/UID (not SID) 115 void restoreCallingIdentity(int64_t token); 116 117 status_t setupPolling(int* fd); 118 status_t handlePolledCommands(); 119 void flushCommands(); 120 bool flushIfNeeded(); 121 122 void joinThreadPool(bool isMain = true); 123 124 // Stop the local process. 125 void stopProcess(bool immediate = true); 126 127 status_t transact(int32_t handle, 128 uint32_t code, const Parcel& data, 129 Parcel* reply, uint32_t flags); 130 131 void incStrongHandle(int32_t handle, BpBinder *proxy); 132 void decStrongHandle(int32_t handle); 133 void incWeakHandle(int32_t handle, BpBinder *proxy); 134 void decWeakHandle(int32_t handle); 135 status_t attemptIncStrongHandle(int32_t handle); 136 static void expungeHandle(int32_t handle, IBinder* binder); 137 status_t requestDeathNotification( int32_t handle, 138 BpBinder* proxy); 139 status_t clearDeathNotification( int32_t handle, 140 BpBinder* proxy); 141 142 static void shutdown(); 143 144 // Call this to disable switching threads to background scheduling when 145 // receiving incoming IPC calls. This is specifically here for the 146 // Android system process, since it expects to have background apps calling 147 // in to it but doesn't want to acquire locks in its services while in 148 // the background. 149 static void disableBackgroundScheduling(bool disable); 150 bool backgroundSchedulingDisabled(); 151 152 // Call blocks until the number of executing binder threads is less than 153 // the maximum number of binder threads threads allowed for this process. 154 void blockUntilThreadAvailable(); 155 156 // Service manager registration 157 void setTheContextObject(const sp<BBinder>& obj); 158 159 // WARNING: DO NOT USE THIS API 160 // 161 // Returns a pointer to the stack from the last time a transaction 162 // was initiated by the kernel. Used to compare when making nested 163 // calls between multiple different transports. 164 const void* getServingStackPointer() const; 165 166 // The work source represents the UID of the process we should attribute the transaction 167 // to. We use -1 to specify that the work source was not set using #setWorkSource. 168 // 169 // This constant needs to be kept in sync with Binder.UNSET_WORKSOURCE from the Java 170 // side. 171 static const int32_t kUnsetWorkSource = -1; 172 private: 173 IPCThreadState(); 174 ~IPCThreadState(); 175 176 status_t sendReply(const Parcel& reply, uint32_t flags); 177 status_t waitForResponse(Parcel *reply, 178 status_t *acquireResult=nullptr); 179 status_t talkWithDriver(bool doReceive=true); 180 status_t writeTransactionData(int32_t cmd, 181 uint32_t binderFlags, 182 int32_t handle, 183 uint32_t code, 184 const Parcel& data, 185 status_t* statusBuffer); 186 status_t getAndExecuteCommand(); 187 status_t executeCommand(int32_t command); 188 void processPendingDerefs(); 189 void processPostWriteDerefs(); 190 191 void clearCaller(); 192 193 static void threadDestructor(void *st); 194 static void freeBuffer(Parcel* parcel, 195 const uint8_t* data, size_t dataSize, 196 const binder_size_t* objects, size_t objectsSize); 197 198 const sp<ProcessState> mProcess; 199 Vector<BBinder*> mPendingStrongDerefs; 200 Vector<RefBase::weakref_type*> mPendingWeakDerefs; 201 Vector<RefBase*> mPostWriteStrongDerefs; 202 Vector<RefBase::weakref_type*> mPostWriteWeakDerefs; 203 Parcel mIn; 204 Parcel mOut; 205 status_t mLastError; 206 const void* mServingStackPointer; 207 pid_t mCallingPid; 208 const char* mCallingSid; 209 uid_t mCallingUid; 210 // The UID of the process who is responsible for this transaction. 211 // This is used for resource attribution. 212 int32_t mWorkSource; 213 // Whether the work source should be propagated. 214 bool mPropagateWorkSource; 215 bool mIsLooper; 216 bool mIsFlushing; 217 int32_t mStrictModePolicy; 218 int32_t mLastTransactionBinderFlags; 219 CallRestriction mCallRestriction; 220 }; 221 222 } // namespace android 223 224 // --------------------------------------------------------------------------- 225