1 /*
2  * Copyright (C) 2012-2014 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 #ifndef _LOGD_LOG_BUFFER_ELEMENT_H__
18 #define _LOGD_LOG_BUFFER_ELEMENT_H__
19 
20 #include <stdatomic.h>
21 #include <stdlib.h>
22 #include <sys/types.h>
23 
24 #include <log/log.h>
25 #include <sysutils/SocketClient.h>
26 
27 class LogBuffer;
28 
29 #define EXPIRE_HOUR_THRESHOLD 24  // Only expire chatty UID logs to preserve
30                                   // non-chatty UIDs less than this age in hours
31 #define EXPIRE_THRESHOLD 10       // A smaller expire count is considered too
32                                   // chatty for the temporal expire messages
33 #define EXPIRE_RATELIMIT 10  // maximum rate in seconds to report expiration
34 
35 class __attribute__((packed)) LogBufferElement {
36     friend LogBuffer;
37 
38     // sized to match reality of incoming log packets
39     const uint32_t mUid;
40     const uint32_t mPid;
41     const uint32_t mTid;
42     log_time mRealTime;
43     char* mMsg;
44     union {
45         const uint16_t mMsgLen;  // mDropped == false
46         uint16_t mDroppedCount;  // mDropped == true
47     };
48     const uint8_t mLogId;
49     bool mDropped;
50 
51     static atomic_int_fast64_t sequence;
52 
53     // assumption: mDropped == true
54     size_t populateDroppedMessage(char*& buffer, LogBuffer* parent,
55                                   bool lastSame);
56 
57    public:
58     LogBufferElement(log_id_t log_id, log_time realtime, uid_t uid, pid_t pid,
59                      pid_t tid, const char* msg, unsigned short len);
60     LogBufferElement(const LogBufferElement& elem);
61     ~LogBufferElement();
62 
isBinary(void)63     bool isBinary(void) const {
64         return (mLogId == LOG_ID_EVENTS) || (mLogId == LOG_ID_SECURITY);
65     }
66 
getLogId()67     log_id_t getLogId() const {
68         return static_cast<log_id_t>(mLogId);
69     }
getUid(void)70     uid_t getUid(void) const {
71         return mUid;
72     }
getPid(void)73     pid_t getPid(void) const {
74         return mPid;
75     }
getTid(void)76     pid_t getTid(void) const {
77         return mTid;
78     }
79     uint32_t getTag() const;
getDropped(void)80     unsigned short getDropped(void) const {
81         return mDropped ? mDroppedCount : 0;
82     }
83     unsigned short setDropped(unsigned short value);
getMsgLen()84     unsigned short getMsgLen() const {
85         return mDropped ? 0 : mMsgLen;
86     }
getMsg()87     const char* getMsg() const {
88         return mDropped ? nullptr : mMsg;
89     }
getRealTime(void)90     log_time getRealTime(void) const {
91         return mRealTime;
92     }
93 
94     static const log_time FLUSH_ERROR;
95     log_time flushTo(SocketClient* writer, LogBuffer* parent, bool privileged,
96                      bool lastSame);
97 };
98 
99 #endif
100