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 sp<ProcessState> process(); 57 58 status_t clearLastError(); 59 60 /** 61 * Returns the PID of the process which has made the current binder 62 * call. If not in a binder call, this will return getpid. If the 63 * call is oneway, this will return 0. 64 */ 65 pid_t getCallingPid() const; 66 67 /** 68 * Returns the SELinux security identifier of the process which has 69 * made the current binder call. If not in a binder call this will 70 * return nullptr. If this isn't requested with 71 * Binder::setRequestingSid, it will also return nullptr. 72 * 73 * This can't be restored once it's cleared, and it does not return the 74 * context of the current process when not in a binder call. 75 */ 76 const char* getCallingSid() const; 77 78 /** 79 * Returns the UID of the process which has made the current binder 80 * call. If not in a binder call, this will return 0. 81 */ 82 uid_t getCallingUid() const; 83 84 void setStrictModePolicy(int32_t policy); 85 int32_t getStrictModePolicy() const; 86 87 // See Binder#setCallingWorkSourceUid in Binder.java. 88 int64_t setCallingWorkSourceUid(uid_t uid); 89 // Internal only. Use setCallingWorkSourceUid(uid) instead. 90 int64_t setCallingWorkSourceUidWithoutPropagation(uid_t uid); 91 // See Binder#getCallingWorkSourceUid in Binder.java. 92 uid_t getCallingWorkSourceUid() const; 93 // See Binder#clearCallingWorkSource in Binder.java. 94 int64_t clearCallingWorkSource(); 95 // See Binder#restoreCallingWorkSource in Binder.java. 96 void restoreCallingWorkSource(int64_t token); 97 void clearPropagateWorkSource(); 98 bool shouldPropagateWorkSource() const; 99 100 void setLastTransactionBinderFlags(int32_t flags); 101 int32_t getLastTransactionBinderFlags() const; 102 103 void setCallRestriction(CallRestriction restriction); 104 CallRestriction getCallRestriction() const; 105 106 int64_t clearCallingIdentity(); 107 // Restores PID/UID (not SID) 108 void restoreCallingIdentity(int64_t token); 109 110 status_t setupPolling(int* fd); 111 status_t handlePolledCommands(); 112 void flushCommands(); 113 bool flushIfNeeded(); 114 115 void joinThreadPool(bool isMain = true); 116 117 // Stop the local process. 118 void stopProcess(bool immediate = true); 119 120 status_t transact(int32_t handle, 121 uint32_t code, const Parcel& data, 122 Parcel* reply, uint32_t flags); 123 124 void incStrongHandle(int32_t handle, BpBinder *proxy); 125 void decStrongHandle(int32_t handle); 126 void incWeakHandle(int32_t handle, BpBinder *proxy); 127 void decWeakHandle(int32_t handle); 128 status_t attemptIncStrongHandle(int32_t handle); 129 static void expungeHandle(int32_t handle, IBinder* binder); 130 status_t requestDeathNotification( int32_t handle, 131 BpBinder* proxy); 132 status_t clearDeathNotification( int32_t handle, 133 BpBinder* proxy); 134 135 static void shutdown(); 136 137 // Call this to disable switching threads to background scheduling when 138 // receiving incoming IPC calls. This is specifically here for the 139 // Android system process, since it expects to have background apps calling 140 // in to it but doesn't want to acquire locks in its services while in 141 // the background. 142 static void disableBackgroundScheduling(bool disable); 143 bool backgroundSchedulingDisabled(); 144 145 // Call blocks until the number of executing binder threads is less than 146 // the maximum number of binder threads threads allowed for this process. 147 void blockUntilThreadAvailable(); 148 149 // Service manager registration 150 void setTheContextObject(const sp<BBinder>& obj); 151 152 // WARNING: DO NOT USE THIS API 153 // 154 // Returns a pointer to the stack from the last time a transaction 155 // was initiated by the kernel. Used to compare when making nested 156 // calls between multiple different transports. 157 const void* getServingStackPointer() const; 158 159 // The work source represents the UID of the process we should attribute the transaction 160 // to. We use -1 to specify that the work source was not set using #setWorkSource. 161 // 162 // This constant needs to be kept in sync with Binder.UNSET_WORKSOURCE from the Java 163 // side. 164 static const int32_t kUnsetWorkSource = -1; 165 private: 166 IPCThreadState(); 167 ~IPCThreadState(); 168 169 status_t sendReply(const Parcel& reply, uint32_t flags); 170 status_t waitForResponse(Parcel *reply, 171 status_t *acquireResult=nullptr); 172 status_t talkWithDriver(bool doReceive=true); 173 status_t writeTransactionData(int32_t cmd, 174 uint32_t binderFlags, 175 int32_t handle, 176 uint32_t code, 177 const Parcel& data, 178 status_t* statusBuffer); 179 status_t getAndExecuteCommand(); 180 status_t executeCommand(int32_t command); 181 void processPendingDerefs(); 182 void processPostWriteDerefs(); 183 184 void clearCaller(); 185 186 static void threadDestructor(void *st); 187 static void freeBuffer(Parcel* parcel, 188 const uint8_t* data, size_t dataSize, 189 const binder_size_t* objects, size_t objectsSize); 190 191 const sp<ProcessState> mProcess; 192 Vector<BBinder*> mPendingStrongDerefs; 193 Vector<RefBase::weakref_type*> mPendingWeakDerefs; 194 Vector<RefBase*> mPostWriteStrongDerefs; 195 Vector<RefBase::weakref_type*> mPostWriteWeakDerefs; 196 Parcel mIn; 197 Parcel mOut; 198 status_t mLastError; 199 const void* mServingStackPointer; 200 pid_t mCallingPid; 201 const char* mCallingSid; 202 uid_t mCallingUid; 203 // The UID of the process who is responsible for this transaction. 204 // This is used for resource attribution. 205 int32_t mWorkSource; 206 // Whether the work source should be propagated. 207 bool mPropagateWorkSource; 208 bool mIsLooper; 209 bool mIsFlushing; 210 int32_t mStrictModePolicy; 211 int32_t mLastTransactionBinderFlags; 212 CallRestriction mCallRestriction; 213 }; 214 215 } // namespace android 216 217 // --------------------------------------------------------------------------- 218