1 /*
2 * Copyright (C) 2016 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 #include "rotate_logs.h"
18
19 #include <stdio.h>
20 #include <string.h>
21 #include <sys/types.h>
22
23 #include <string>
24
25 #include <android-base/file.h>
26 #include <android-base/logging.h>
27 #include <android-base/parseint.h>
28 #include <android-base/stringprintf.h>
29 #include <private/android_logger.h> /* private pmsg functions */
30
31 static const std::string LAST_KMSG_FILTER = "recovery/last_kmsg";
32 static const std::string LAST_LOG_FILTER = "recovery/last_log";
33
logbasename(log_id_t,char,const char * filename,const char *,size_t len,void * arg)34 ssize_t logbasename(
35 log_id_t /* logId */,
36 char /* prio */,
37 const char *filename,
38 const char * /* buf */, size_t len,
39 void *arg) {
40 bool* doRotate = static_cast<bool*>(arg);
41 if (LAST_KMSG_FILTER.find(filename) != std::string::npos ||
42 LAST_LOG_FILTER.find(filename) != std::string::npos) {
43 *doRotate = true;
44 }
45 return len;
46 }
47
logrotate(log_id_t logId,char prio,const char * filename,const char * buf,size_t len,void * arg)48 ssize_t logrotate(
49 log_id_t logId,
50 char prio,
51 const char *filename,
52 const char *buf, size_t len,
53 void *arg) {
54 bool* doRotate = static_cast<bool*>(arg);
55 if (!*doRotate) {
56 return __android_log_pmsg_file_write(logId, prio, filename, buf, len);
57 }
58
59 std::string name(filename);
60 size_t dot = name.find_last_of('.');
61 std::string sub = name.substr(0, dot);
62
63 if (LAST_KMSG_FILTER.find(sub) == std::string::npos &&
64 LAST_LOG_FILTER.find(sub) == std::string::npos) {
65 return __android_log_pmsg_file_write(logId, prio, filename, buf, len);
66 }
67
68 // filename rotation
69 if (dot == std::string::npos) {
70 name += ".1";
71 } else {
72 std::string number = name.substr(dot + 1);
73 if (!isdigit(number[0])) {
74 name += ".1";
75 } else {
76 size_t i;
77 if (!android::base::ParseUint(number, &i)) {
78 LOG(ERROR) << "failed to parse uint in " << number;
79 return -1;
80 }
81 name = sub + "." + std::to_string(i + 1);
82 }
83 }
84
85 return __android_log_pmsg_file_write(logId, prio, name.c_str(), buf, len);
86 }
87
88 // Rename last_log -> last_log.1 -> last_log.2 -> ... -> last_log.$max.
89 // Similarly rename last_kmsg -> last_kmsg.1 -> ... -> last_kmsg.$max.
90 // Overwrite any existing last_log.$max and last_kmsg.$max.
rotate_logs(const char * last_log_file,const char * last_kmsg_file)91 void rotate_logs(const char* last_log_file, const char* last_kmsg_file) {
92 // Logs should only be rotated once.
93 static bool rotated = false;
94 if (rotated) {
95 return;
96 }
97 rotated = true;
98
99 for (int i = KEEP_LOG_COUNT - 1; i >= 0; --i) {
100 std::string old_log = android::base::StringPrintf("%s", last_log_file);
101 if (i > 0) {
102 old_log += "." + std::to_string(i);
103 }
104 std::string new_log = android::base::StringPrintf("%s.%d", last_log_file, i+1);
105 // Ignore errors if old_log doesn't exist.
106 rename(old_log.c_str(), new_log.c_str());
107
108 std::string old_kmsg = android::base::StringPrintf("%s", last_kmsg_file);
109 if (i > 0) {
110 old_kmsg += "." + std::to_string(i);
111 }
112 std::string new_kmsg = android::base::StringPrintf("%s.%d", last_kmsg_file, i+1);
113 rename(old_kmsg.c_str(), new_kmsg.c_str());
114 }
115 }
116