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 "otautil/logging.h" 18 19 #include <dirent.h> 20 #include <errno.h> 21 #include <stdio.h> 22 #include <string.h> 23 #include <sys/klog.h> 24 #include <sys/types.h> 25 26 #include <algorithm> 27 #include <memory> 28 #include <string> 29 30 #include <android-base/file.h> 31 #include <android-base/logging.h> 32 #include <android-base/parseint.h> 33 #include <android-base/stringprintf.h> 34 #include <android-base/unique_fd.h> 35 #include <private/android_filesystem_config.h> /* for AID_SYSTEM */ 36 #include <private/android_logger.h> /* private pmsg functions */ 37 #include <selinux/label.h> 38 39 #include "otautil/dirutil.h" 40 #include "otautil/paths.h" 41 #include "otautil/roots.h" 42 43 constexpr const char* LOG_FILE = "/cache/recovery/log"; 44 constexpr const char* LAST_INSTALL_FILE = "/cache/recovery/last_install"; 45 constexpr const char* LAST_KMSG_FILE = "/cache/recovery/last_kmsg"; 46 constexpr const char* LAST_LOG_FILE = "/cache/recovery/last_log"; 47 48 constexpr const char* LAST_KMSG_FILTER = "recovery/last_kmsg"; 49 constexpr const char* LAST_LOG_FILTER = "recovery/last_log"; 50 51 constexpr const char* CACHE_LOG_DIR = "/cache/recovery"; 52 53 static struct selabel_handle* logging_sehandle; 54 55 void SetLoggingSehandle(selabel_handle* handle) { 56 logging_sehandle = handle; 57 } 58 59 // fopen(3)'s the given file, by mounting volumes and making parent dirs as necessary. Returns the 60 // file pointer, or nullptr on error. 61 static FILE* fopen_path(const std::string& path, const char* mode, const selabel_handle* sehandle) { 62 if (ensure_path_mounted(path) != 0) { 63 LOG(ERROR) << "Can't mount " << path; 64 return nullptr; 65 } 66 67 // When writing, try to create the containing directory, if necessary. Use generous permissions, 68 // the system (init.rc) will reset them. 69 if (strchr("wa", mode[0])) { 70 mkdir_recursively(path, 0777, true, sehandle); 71 } 72 return fopen(path.c_str(), mode); 73 } 74 75 void check_and_fclose(FILE* fp, const std::string& name) { 76 fflush(fp); 77 if (fsync(fileno(fp)) == -1) { 78 PLOG(ERROR) << "Failed to fsync " << name; 79 } 80 if (ferror(fp)) { 81 PLOG(ERROR) << "Error in " << name; 82 } 83 fclose(fp); 84 } 85 86 // close a file, log an error if the error indicator is set 87 ssize_t logbasename(log_id_t /* id */, char /* prio */, const char* filename, const char* /* buf */, 88 size_t len, void* arg) { 89 bool* do_rotate = static_cast<bool*>(arg); 90 if (std::string(LAST_KMSG_FILTER).find(filename) != std::string::npos || 91 std::string(LAST_LOG_FILTER).find(filename) != std::string::npos) { 92 *do_rotate = true; 93 } 94 return len; 95 } 96 97 ssize_t logrotate(log_id_t id, char prio, const char* filename, const char* buf, size_t len, 98 void* arg) { 99 bool* do_rotate = static_cast<bool*>(arg); 100 if (!*do_rotate) { 101 return __android_log_pmsg_file_write(id, prio, filename, buf, len); 102 } 103 104 std::string name(filename); 105 size_t dot = name.find_last_of('.'); 106 std::string sub = name.substr(0, dot); 107 108 if (std::string(LAST_KMSG_FILTER).find(sub) == std::string::npos && 109 std::string(LAST_LOG_FILTER).find(sub) == std::string::npos) { 110 return __android_log_pmsg_file_write(id, prio, filename, buf, len); 111 } 112 113 // filename rotation 114 if (dot == std::string::npos) { 115 name += ".1"; 116 } else { 117 std::string number = name.substr(dot + 1); 118 if (!isdigit(number[0])) { 119 name += ".1"; 120 } else { 121 size_t i; 122 if (!android::base::ParseUint(number, &i)) { 123 LOG(ERROR) << "failed to parse uint in " << number; 124 return -1; 125 } 126 name = sub + "." + std::to_string(i + 1); 127 } 128 } 129 130 return __android_log_pmsg_file_write(id, prio, name.c_str(), buf, len); 131 } 132 133 // Rename last_log -> last_log.1 -> last_log.2 -> ... -> last_log.$max. 134 // Similarly rename last_kmsg -> last_kmsg.1 -> ... -> last_kmsg.$max. 135 // Overwrite any existing last_log.$max and last_kmsg.$max. 136 void rotate_logs(const char* last_log_file, const char* last_kmsg_file) { 137 // Logs should only be rotated once. 138 static bool rotated = false; 139 if (rotated) { 140 return; 141 } 142 rotated = true; 143 144 for (int i = KEEP_LOG_COUNT - 1; i >= 0; --i) { 145 std::string old_log = android::base::StringPrintf("%s", last_log_file); 146 if (i > 0) { 147 old_log += "." + std::to_string(i); 148 } 149 std::string new_log = android::base::StringPrintf("%s.%d", last_log_file, i + 1); 150 // Ignore errors if old_log doesn't exist. 151 rename(old_log.c_str(), new_log.c_str()); 152 153 std::string old_kmsg = android::base::StringPrintf("%s", last_kmsg_file); 154 if (i > 0) { 155 old_kmsg += "." + std::to_string(i); 156 } 157 std::string new_kmsg = android::base::StringPrintf("%s.%d", last_kmsg_file, i + 1); 158 rename(old_kmsg.c_str(), new_kmsg.c_str()); 159 } 160 } 161 162 // Writes content to the current pmsg session. 163 static ssize_t __pmsg_write(const std::string& filename, const std::string& buf) { 164 return __android_log_pmsg_file_write(LOG_ID_SYSTEM, ANDROID_LOG_INFO, filename.c_str(), 165 buf.data(), buf.size()); 166 } 167 168 void copy_log_file_to_pmsg(const std::string& source, const std::string& destination) { 169 std::string content; 170 android::base::ReadFileToString(source, &content); 171 __pmsg_write(destination, content); 172 } 173 174 // How much of the temp log we have copied to the copy in cache. 175 static off_t tmplog_offset = 0; 176 177 void reset_tmplog_offset() { 178 tmplog_offset = 0; 179 } 180 181 static void copy_log_file(const std::string& source, const std::string& destination, bool append, 182 const selabel_handle* sehandle) { 183 FILE* dest_fp = fopen_path(destination, append ? "ae" : "we", sehandle); 184 if (dest_fp == nullptr) { 185 PLOG(ERROR) << "Can't open " << destination; 186 } else { 187 FILE* source_fp = fopen(source.c_str(), "re"); 188 if (source_fp != nullptr) { 189 if (append) { 190 fseeko(source_fp, tmplog_offset, SEEK_SET); // Since last write 191 } 192 char buf[4096]; 193 size_t bytes; 194 while ((bytes = fread(buf, 1, sizeof(buf), source_fp)) != 0) { 195 fwrite(buf, 1, bytes, dest_fp); 196 } 197 if (append) { 198 tmplog_offset = ftello(source_fp); 199 } 200 check_and_fclose(source_fp, source); 201 } 202 check_and_fclose(dest_fp, destination); 203 } 204 } 205 206 void copy_logs(bool save_current_log, bool has_cache, const selabel_handle* sehandle) { 207 // We only rotate and record the log of the current session if explicitly requested. This usually 208 // happens after wipes, installation from BCB or menu selections. This is to avoid unnecessary 209 // rotation (and possible deletion) of log files, if it does not do anything loggable. 210 if (!save_current_log) { 211 return; 212 } 213 214 // Always write to pmsg, this allows the OTA logs to be caught in `logcat -L`. 215 copy_log_file_to_pmsg(Paths::Get().temporary_log_file(), LAST_LOG_FILE); 216 copy_log_file_to_pmsg(Paths::Get().temporary_install_file(), LAST_INSTALL_FILE); 217 218 // We can do nothing for now if there's no /cache partition. 219 if (!has_cache) { 220 return; 221 } 222 223 ensure_path_mounted(LAST_LOG_FILE); 224 ensure_path_mounted(LAST_KMSG_FILE); 225 rotate_logs(LAST_LOG_FILE, LAST_KMSG_FILE); 226 227 // Copy logs to cache so the system can find out what happened. 228 copy_log_file(Paths::Get().temporary_log_file(), LOG_FILE, true, sehandle); 229 copy_log_file(Paths::Get().temporary_log_file(), LAST_LOG_FILE, false, sehandle); 230 copy_log_file(Paths::Get().temporary_install_file(), LAST_INSTALL_FILE, false, sehandle); 231 save_kernel_log(LAST_KMSG_FILE); 232 chmod(LOG_FILE, 0600); 233 chown(LOG_FILE, AID_SYSTEM, AID_SYSTEM); 234 chmod(LAST_KMSG_FILE, 0600); 235 chown(LAST_KMSG_FILE, AID_SYSTEM, AID_SYSTEM); 236 chmod(LAST_LOG_FILE, 0640); 237 chmod(LAST_INSTALL_FILE, 0644); 238 chown(LAST_INSTALL_FILE, AID_SYSTEM, AID_SYSTEM); 239 sync(); 240 } 241 242 // Read from kernel log into buffer and write out to file. 243 void save_kernel_log(const char* destination) { 244 int klog_buf_len = klogctl(KLOG_SIZE_BUFFER, 0, 0); 245 if (klog_buf_len <= 0) { 246 PLOG(ERROR) << "Error getting klog size"; 247 return; 248 } 249 250 std::string buffer(klog_buf_len, 0); 251 int n = klogctl(KLOG_READ_ALL, &buffer[0], klog_buf_len); 252 if (n == -1) { 253 PLOG(ERROR) << "Error in reading klog"; 254 return; 255 } 256 buffer.resize(n); 257 android::base::WriteStringToFile(buffer, destination); 258 } 259 260 std::vector<saved_log_file> ReadLogFilesToMemory() { 261 ensure_path_mounted("/cache"); 262 263 struct dirent* de; 264 std::unique_ptr<DIR, decltype(&closedir)> d(opendir(CACHE_LOG_DIR), closedir); 265 if (!d) { 266 if (errno != ENOENT) { 267 PLOG(ERROR) << "Failed to opendir " << CACHE_LOG_DIR; 268 } 269 return {}; 270 } 271 272 std::vector<saved_log_file> log_files; 273 while ((de = readdir(d.get())) != nullptr) { 274 if (strncmp(de->d_name, "last_", 5) == 0 || strcmp(de->d_name, "log") == 0) { 275 std::string path = android::base::StringPrintf("%s/%s", CACHE_LOG_DIR, de->d_name); 276 277 struct stat sb; 278 if (stat(path.c_str(), &sb) != 0) { 279 PLOG(ERROR) << "Failed to stat " << path; 280 continue; 281 } 282 // Truncate files to 512kb 283 size_t read_size = std::min<size_t>(sb.st_size, 1 << 19); 284 std::string data(read_size, '\0'); 285 286 android::base::unique_fd log_fd(TEMP_FAILURE_RETRY(open(path.c_str(), O_RDONLY))); 287 if (log_fd == -1 || !android::base::ReadFully(log_fd, data.data(), read_size)) { 288 PLOG(ERROR) << "Failed to read log file " << path; 289 continue; 290 } 291 292 log_files.emplace_back(saved_log_file{ path, sb, data }); 293 } 294 } 295 296 return log_files; 297 } 298 299 bool RestoreLogFilesAfterFormat(const std::vector<saved_log_file>& log_files) { 300 // Re-create the log dir and write back the log entries. 301 if (ensure_path_mounted(CACHE_LOG_DIR) != 0) { 302 PLOG(ERROR) << "Failed to mount " << CACHE_LOG_DIR; 303 return false; 304 } 305 306 if (mkdir_recursively(CACHE_LOG_DIR, 0777, false, logging_sehandle) != 0) { 307 PLOG(ERROR) << "Failed to create " << CACHE_LOG_DIR; 308 return false; 309 } 310 311 for (const auto& log : log_files) { 312 if (!android::base::WriteStringToFile(log.data, log.name, log.sb.st_mode, log.sb.st_uid, 313 log.sb.st_gid)) { 314 PLOG(ERROR) << "Failed to write to " << log.name; 315 } 316 } 317 318 // Any part of the log we'd copied to cache is now gone. 319 // Reset the pointer so we copy from the beginning of the temp 320 // log. 321 reset_tmplog_offset(); 322 copy_logs(true /* save_current_log */, true /* has_cache */, logging_sehandle); 323 324 return true; 325 } 326