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 <android/log.h>
26 #include <private/android_filesystem_config.h>
27 #include <sysutils/SocketClient.h>
28
29 #include "LogBufferElement.h"
30 #include "LogBufferInterface.h"
31 #include "LogStatistics.h"
32 #include "LogTags.h"
33 #include "LogTimes.h"
34 #include "LogWhiteBlackList.h"
35
36 //
37 // We are either in 1970ish (MONOTONIC) or 2016+ish (REALTIME) so to
38 // differentiate without prejudice, we use 1972 to delineate, earlier
39 // is likely monotonic, later is real. Otherwise we start using a
40 // dividing line between monotonic and realtime if more than a minute
41 // difference between them.
42 //
43 namespace android {
44
isMonotonic(const log_time & mono)45 static bool isMonotonic(const log_time& mono) {
46 static const uint32_t EPOCH_PLUS_2_YEARS = 2 * 24 * 60 * 60 * 1461 / 4;
47 static const uint32_t EPOCH_PLUS_MINUTE = 60;
48
49 if (mono.tv_sec >= EPOCH_PLUS_2_YEARS) {
50 return false;
51 }
52
53 log_time now(CLOCK_REALTIME);
54
55 /* Timezone and ntp time setup? */
56 if (now.tv_sec >= EPOCH_PLUS_2_YEARS) {
57 return true;
58 }
59
60 /* no way to differentiate realtime from monotonic time */
61 if (now.tv_sec < EPOCH_PLUS_MINUTE) {
62 return false;
63 }
64
65 log_time cpu(CLOCK_MONOTONIC);
66 /* too close to call to differentiate monotonic times from realtime */
67 if ((cpu.tv_sec + EPOCH_PLUS_MINUTE) >= now.tv_sec) {
68 return false;
69 }
70
71 /* dividing line half way between monotonic and realtime */
72 return mono.tv_sec < ((cpu.tv_sec + now.tv_sec) / 2);
73 }
74 }
75
76 typedef std::list<LogBufferElement*> LogBufferElementCollection;
77
78 class LogBuffer : public LogBufferInterface {
79 LogBufferElementCollection mLogElements;
80 pthread_rwlock_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, LogBufferElementCollection::iterator>
90 LogBufferIteratorMap;
91 LogBufferIteratorMap mLastWorst[LOG_ID_MAX];
92 // watermark of any worst/chatty pid of system processing
93 typedef std::unordered_map<pid_t, LogBufferElementCollection::iterator>
94 LogBufferPidIteratorMap;
95 LogBufferPidIteratorMap mLastWorstPidOfSystem[LOG_ID_MAX];
96
97 unsigned long mMaxSize[LOG_ID_MAX];
98
99 bool monotonic;
100
101 LogTags tags;
102
103 LogBufferElement* lastLoggedElements[LOG_ID_MAX];
104 LogBufferElement* droppedElements[LOG_ID_MAX];
105 void log(LogBufferElement* elem);
106
107 public:
108 LastLogTimes& mTimes;
109
110 explicit LogBuffer(LastLogTimes* times);
111 ~LogBuffer() override;
112 void init();
isMonotonic()113 bool isMonotonic() {
114 return monotonic;
115 }
116
117 int log(log_id_t log_id, log_time realtime, uid_t uid, pid_t pid, pid_t tid,
118 const char* msg, uint16_t len) override;
119 // lastTid is an optional context to help detect if the last previous
120 // valid message was from the same source so we can differentiate chatty
121 // filter types (identical or expired)
122 log_time flushTo(SocketClient* writer, const log_time& start,
123 pid_t* lastTid, // &lastTid[LOG_ID_MAX] or nullptr
124 bool privileged, bool security,
125 int (*filter)(const LogBufferElement* element,
126 void* arg) = nullptr,
127 void* arg = nullptr);
128
129 bool clear(log_id_t id, uid_t uid = AID_ROOT);
130 unsigned long getSize(log_id_t id);
131 int setSize(log_id_t id, unsigned long size);
132 unsigned long getSizeUsed(log_id_t id);
133
134 std::string formatStatistics(uid_t uid, pid_t pid, unsigned int logMask);
135
enableStatistics()136 void enableStatistics() {
137 stats.enableStatistics();
138 }
139
initPrune(const char * cp)140 int initPrune(const char* cp) {
141 return mPrune.init(cp);
142 }
formatPrune()143 std::string formatPrune() {
144 return mPrune.format();
145 }
146
formatGetEventTag(uid_t uid,const char * name,const char * format)147 std::string formatGetEventTag(uid_t uid, const char* name,
148 const char* format) {
149 return tags.formatGetEventTag(uid, name, format);
150 }
formatEntry(uint32_t tag,uid_t uid)151 std::string formatEntry(uint32_t tag, uid_t uid) {
152 return tags.formatEntry(tag, uid);
153 }
tagToName(uint32_t tag)154 const char* tagToName(uint32_t tag) {
155 return tags.tagToName(tag);
156 }
157
158 // helper must be protected directly or implicitly by wrlock()/unlock()
pidToName(pid_t pid)159 const char* pidToName(pid_t pid) {
160 return stats.pidToName(pid);
161 }
pidToUid(pid_t pid)162 virtual uid_t pidToUid(pid_t pid) override {
163 return stats.pidToUid(pid);
164 }
tidToPid(pid_t tid)165 virtual pid_t tidToPid(pid_t tid) override {
166 return stats.tidToPid(tid);
167 }
uidToName(uid_t uid)168 const char* uidToName(uid_t uid) {
169 return stats.uidToName(uid);
170 }
wrlock()171 void wrlock() {
172 pthread_rwlock_wrlock(&mLogElementsLock);
173 }
rdlock()174 void rdlock() {
175 pthread_rwlock_rdlock(&mLogElementsLock);
176 }
unlock()177 void unlock() {
178 pthread_rwlock_unlock(&mLogElementsLock);
179 }
180
181 private:
182 static constexpr size_t minPrune = 4;
183 static constexpr size_t maxPrune = 256;
184 static const log_time pruneMargin;
185
186 void maybePrune(log_id_t id);
187 bool isBusy(log_time watermark);
188 void kickMe(LogTimeEntry* me, log_id_t id, unsigned long pruneRows);
189
190 bool prune(log_id_t id, unsigned long pruneRows, uid_t uid = AID_ROOT);
191 LogBufferElementCollection::iterator erase(
192 LogBufferElementCollection::iterator it, bool coalesce = false);
193 };
194
195 #endif // _LOGD_LOG_BUFFER_H__
196