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_H__
18 #define _LOGD_LOG_BUFFER_H__
19
20 #include <sys/types.h>
21
22 #include <list>
23 #include <string>
24
25 #include <log/log.h>
26 #include <sysutils/SocketClient.h>
27
28 #include <private/android_filesystem_config.h>
29
30 #include "LogBufferElement.h"
31 #include "LogTimes.h"
32 #include "LogStatistics.h"
33 #include "LogWhiteBlackList.h"
34
35 //
36 // We are either in 1970ish (MONOTONIC) or 2016+ish (REALTIME) so to
37 // differentiate without prejudice, we use 1972 to delineate, earlier
38 // is likely monotonic, later is real. Otherwise we start using a
39 // dividing line between monotonic and realtime if more than a minute
40 // difference between them.
41 //
42 namespace android {
43
isMonotonic(const log_time & mono)44 static bool isMonotonic(const log_time &mono) {
45 static const uint32_t EPOCH_PLUS_2_YEARS = 2 * 24 * 60 * 60 * 1461 / 4;
46 static const uint32_t EPOCH_PLUS_MINUTE = 60;
47
48 if (mono.tv_sec >= EPOCH_PLUS_2_YEARS) {
49 return false;
50 }
51
52 log_time now(CLOCK_REALTIME);
53
54 /* Timezone and ntp time setup? */
55 if (now.tv_sec >= EPOCH_PLUS_2_YEARS) {
56 return true;
57 }
58
59 /* no way to differentiate realtime from monotonic time */
60 if (now.tv_sec < EPOCH_PLUS_MINUTE) {
61 return false;
62 }
63
64 log_time cpu(CLOCK_MONOTONIC);
65 /* too close to call to differentiate monotonic times from realtime */
66 if ((cpu.tv_sec + EPOCH_PLUS_MINUTE) >= now.tv_sec) {
67 return false;
68 }
69
70 /* dividing line half way between monotonic and realtime */
71 return mono.tv_sec < ((cpu.tv_sec + now.tv_sec) / 2);
72 }
73
74 }
75
76 typedef std::list<LogBufferElement *> LogBufferElementCollection;
77
78 class LogBuffer {
79 LogBufferElementCollection mLogElements;
80 pthread_mutex_t mLogElementsLock;
81
82 LogStatistics stats;
83
84 PruneList mPrune;
85 // watermark for last per log id
86 LogBufferElementCollection::iterator mLast[LOG_ID_MAX];
87 bool mLastSet[LOG_ID_MAX];
88 // watermark of any worst/chatty uid processing
89 typedef std::unordered_map<uid_t,
90 LogBufferElementCollection::iterator>
91 LogBufferIteratorMap;
92 LogBufferIteratorMap mLastWorstUid[LOG_ID_MAX];
93 // watermark of any worst/chatty pid of system processing
94 typedef std::unordered_map<pid_t,
95 LogBufferElementCollection::iterator>
96 LogBufferPidIteratorMap;
97 LogBufferPidIteratorMap mLastWorstPidOfSystem[LOG_ID_MAX];
98
99 unsigned long mMaxSize[LOG_ID_MAX];
100
101 bool monotonic;
102
103 public:
104 LastLogTimes &mTimes;
105
106 LogBuffer(LastLogTimes *times);
107 void init();
isMonotonic()108 bool isMonotonic() { return monotonic; }
109
110 int log(log_id_t log_id, log_time realtime,
111 uid_t uid, pid_t pid, pid_t tid,
112 const char *msg, unsigned short len);
113 uint64_t flushTo(SocketClient *writer, const uint64_t start,
114 bool privileged, bool security,
115 int (*filter)(const LogBufferElement *element, void *arg) = NULL,
116 void *arg = NULL);
117
118 bool clear(log_id_t id, uid_t uid = AID_ROOT);
119 unsigned long getSize(log_id_t id);
120 int setSize(log_id_t id, unsigned long size);
121 unsigned long getSizeUsed(log_id_t id);
122 // *strp uses malloc, use free to release.
123 std::string formatStatistics(uid_t uid, pid_t pid, unsigned int logMask);
124
enableStatistics()125 void enableStatistics() {
126 stats.enableStatistics();
127 }
128
initPrune(const char * cp)129 int initPrune(const char *cp) { return mPrune.init(cp); }
formatPrune()130 std::string formatPrune() { return mPrune.format(); }
131
132 // helper must be protected directly or implicitly by lock()/unlock()
pidToName(pid_t pid)133 const char *pidToName(pid_t pid) { return stats.pidToName(pid); }
pidToUid(pid_t pid)134 uid_t pidToUid(pid_t pid) { return stats.pidToUid(pid); }
uidToName(uid_t uid)135 const char *uidToName(uid_t uid) { return stats.uidToName(uid); }
lock()136 void lock() { pthread_mutex_lock(&mLogElementsLock); }
unlock()137 void unlock() { pthread_mutex_unlock(&mLogElementsLock); }
138
139 private:
140
141 static constexpr size_t minPrune = 4;
142 static constexpr size_t maxPrune = 256;
143
144 void maybePrune(log_id_t id);
145 bool prune(log_id_t id, unsigned long pruneRows, uid_t uid = AID_ROOT);
146 LogBufferElementCollection::iterator erase(
147 LogBufferElementCollection::iterator it, bool coalesce = false);
148 };
149
150 #endif // _LOGD_LOG_BUFFER_H__
151