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