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 #define LOG_TAG "recovery-refresh"
18
19 //
20 // Strictly to deal with reboot into system after OTA, then
21 // reboot while in system before boot complete landing us back
22 // into recovery to continue with any mitigations with retained
23 // log history. This simply refreshes the pmsg files from
24 // the last pmsg file contents.
25 //
26 // Usage:
27 // recovery-refresh [--force-rotate|--rotate]
28 //
29 // All file content representing in the recovery/ directory stored in
30 // /sys/fs/pstore/pmsg-ramoops-0 in logger format that reside in the
31 // LOG_ID_SYSTEM buffer at ANDROID_LOG_INFO priority or higher is
32 // refreshed into /dev/pmsg0. This ensures that an unexpected reboot
33 // before recovery-persist is run will still contain the associated
34 // pmsg Android Logger content.
35 //
36 // --force-rotate recovery/last_kmsg and recovery.last_log files are
37 // rotated with .<number> suffixes upwards.
38 // --rotate rotated only if rocovery/last_msg or recovery/last_log
39 // exist, otherwise perform 1:1 refresh.
40 //
41
42 #include <string.h>
43
44 #include <string>
45
46 #include <android/log.h> /* Android Log Priority Tags */
47 #include <log/logger.h> /* Android Log packet format */
48 #include <private/android_logger.h> /* private pmsg functions */
49
50 static const char LAST_KMSG_FILE[] = "recovery/last_kmsg";
51 static const char LAST_LOG_FILE[] = "recovery/last_log";
52
logbasename(log_id_t,char,const char * filename,const char *,size_t len,void * arg)53 static ssize_t logbasename(
54 log_id_t /* logId */,
55 char /* prio */,
56 const char *filename,
57 const char * /* buf */, size_t len,
58 void *arg) {
59 if (strstr(LAST_KMSG_FILE, filename) ||
60 strstr(LAST_LOG_FILE, filename)) {
61 bool *doRotate = reinterpret_cast<bool *>(arg);
62 *doRotate = true;
63 }
64 return len;
65 }
66
logrotate(log_id_t logId,char prio,const char * filename,const char * buf,size_t len,void * arg)67 static ssize_t logrotate(
68 log_id_t logId,
69 char prio,
70 const char *filename,
71 const char *buf, size_t len,
72 void *arg) {
73 bool *doRotate = reinterpret_cast<bool *>(arg);
74 if (!*doRotate) {
75 return __android_log_pmsg_file_write(logId, prio, filename, buf, len);
76 }
77
78 std::string name(filename);
79 size_t dot = name.find_last_of(".");
80 std::string sub = name.substr(0, dot);
81
82 if (!strstr(LAST_KMSG_FILE, sub.c_str()) &&
83 !strstr(LAST_LOG_FILE, sub.c_str())) {
84 return __android_log_pmsg_file_write(logId, prio, filename, buf, len);
85 }
86
87 // filename rotation
88 if (dot == std::string::npos) {
89 name += ".1";
90 } else {
91 std::string number = name.substr(dot + 1);
92 if (!isdigit(number.data()[0])) {
93 name += ".1";
94 } else {
95 unsigned long long i = std::stoull(number);
96 name = sub + "." + std::to_string(i + 1);
97 }
98 }
99
100 return __android_log_pmsg_file_write(logId, prio, name.c_str(), buf, len);
101 }
102
main(int argc,char ** argv)103 int main(int argc, char **argv) {
104 static const char filter[] = "recovery/";
105 static const char force_rotate_flag[] = "--force-rotate";
106 static const char rotate_flag[] = "--rotate";
107 ssize_t ret;
108 bool doRotate = false;
109
110 // Take last pmsg contents and rewrite it to the current pmsg session.
111 if ((argc <= 1) || !argv[1] ||
112 (((doRotate = strcmp(argv[1], rotate_flag))) &&
113 strcmp(argv[1], force_rotate_flag))) {
114 doRotate = false;
115 } else if (!doRotate) {
116 // Do we need to rotate?
117 __android_log_pmsg_file_read(
118 LOG_ID_SYSTEM, ANDROID_LOG_INFO, filter,
119 logbasename, &doRotate);
120 }
121
122 // Take action to refresh pmsg contents
123 ret = __android_log_pmsg_file_read(
124 LOG_ID_SYSTEM, ANDROID_LOG_INFO, filter,
125 logrotate, &doRotate);
126
127 return (ret < 0) ? ret : 0;
128 }
129