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Diffstat (limited to 'otautil/logging.cpp')
-rw-r--r-- | otautil/logging.cpp | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/otautil/logging.cpp b/otautil/logging.cpp new file mode 100644 index 000000000..7c330ac61 --- /dev/null +++ b/otautil/logging.cpp @@ -0,0 +1,245 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "otautil/logging.h" + +#include <stdio.h> +#include <string.h> +#include <sys/klog.h> +#include <sys/types.h> + +#include <string> + +#include <android-base/file.h> +#include <android-base/logging.h> +#include <android-base/parseint.h> +#include <android-base/stringprintf.h> +#include <private/android_filesystem_config.h> /* for AID_SYSTEM */ +#include <private/android_logger.h> /* private pmsg functions */ +#include <selinux/label.h> + +#include "otautil/dirutil.h" +#include "otautil/paths.h" +#include "otautil/roots.h" + +static constexpr const char* LOG_FILE = "/cache/recovery/log"; +static constexpr const char* LAST_INSTALL_FILE = "/cache/recovery/last_install"; +static constexpr const char* LAST_KMSG_FILE = "/cache/recovery/last_kmsg"; +static constexpr const char* LAST_LOG_FILE = "/cache/recovery/last_log"; + +static const std::string LAST_KMSG_FILTER = "recovery/last_kmsg"; +static const std::string LAST_LOG_FILTER = "recovery/last_log"; + +// fopen(3)'s the given file, by mounting volumes and making parent dirs as necessary. Returns the +// file pointer, or nullptr on error. +static FILE* fopen_path(const std::string& path, const char* mode, const selabel_handle* sehandle) { + if (ensure_path_mounted(path) != 0) { + LOG(ERROR) << "Can't mount " << path; + return nullptr; + } + + // When writing, try to create the containing directory, if necessary. Use generous permissions, + // the system (init.rc) will reset them. + if (strchr("wa", mode[0])) { + mkdir_recursively(path, 0777, true, sehandle); + } + return fopen(path.c_str(), mode); +} + +void check_and_fclose(FILE* fp, const std::string& name) { + fflush(fp); + if (fsync(fileno(fp)) == -1) { + PLOG(ERROR) << "Failed to fsync " << name; + } + if (ferror(fp)) { + PLOG(ERROR) << "Error in " << name; + } + fclose(fp); +} + +// close a file, log an error if the error indicator is set +ssize_t logbasename(log_id_t /* id */, char /* prio */, const char* filename, const char* /* buf */, + size_t len, void* arg) { + bool* do_rotate = static_cast<bool*>(arg); + if (LAST_KMSG_FILTER.find(filename) != std::string::npos || + LAST_LOG_FILTER.find(filename) != std::string::npos) { + *do_rotate = true; + } + return len; +} + +ssize_t logrotate(log_id_t id, char prio, const char* filename, const char* buf, size_t len, + void* arg) { + bool* do_rotate = static_cast<bool*>(arg); + if (!*do_rotate) { + return __android_log_pmsg_file_write(id, prio, filename, buf, len); + } + + std::string name(filename); + size_t dot = name.find_last_of('.'); + std::string sub = name.substr(0, dot); + + if (LAST_KMSG_FILTER.find(sub) == std::string::npos && + LAST_LOG_FILTER.find(sub) == std::string::npos) { + return __android_log_pmsg_file_write(id, prio, filename, buf, len); + } + + // filename rotation + if (dot == std::string::npos) { + name += ".1"; + } else { + std::string number = name.substr(dot + 1); + if (!isdigit(number[0])) { + name += ".1"; + } else { + size_t i; + if (!android::base::ParseUint(number, &i)) { + LOG(ERROR) << "failed to parse uint in " << number; + return -1; + } + name = sub + "." + std::to_string(i + 1); + } + } + + return __android_log_pmsg_file_write(id, prio, name.c_str(), buf, len); +} + +// Rename last_log -> last_log.1 -> last_log.2 -> ... -> last_log.$max. +// Similarly rename last_kmsg -> last_kmsg.1 -> ... -> last_kmsg.$max. +// Overwrite any existing last_log.$max and last_kmsg.$max. +void rotate_logs(const char* last_log_file, const char* last_kmsg_file) { + // Logs should only be rotated once. + static bool rotated = false; + if (rotated) { + return; + } + rotated = true; + + for (int i = KEEP_LOG_COUNT - 1; i >= 0; --i) { + std::string old_log = android::base::StringPrintf("%s", last_log_file); + if (i > 0) { + old_log += "." + std::to_string(i); + } + std::string new_log = android::base::StringPrintf("%s.%d", last_log_file, i + 1); + // Ignore errors if old_log doesn't exist. + rename(old_log.c_str(), new_log.c_str()); + + std::string old_kmsg = android::base::StringPrintf("%s", last_kmsg_file); + if (i > 0) { + old_kmsg += "." + std::to_string(i); + } + std::string new_kmsg = android::base::StringPrintf("%s.%d", last_kmsg_file, i + 1); + rename(old_kmsg.c_str(), new_kmsg.c_str()); + } +} + +// Writes content to the current pmsg session. +static ssize_t __pmsg_write(const std::string& filename, const std::string& buf) { + return __android_log_pmsg_file_write(LOG_ID_SYSTEM, ANDROID_LOG_INFO, filename.c_str(), + buf.data(), buf.size()); +} + +void copy_log_file_to_pmsg(const std::string& source, const std::string& destination) { + std::string content; + android::base::ReadFileToString(source, &content); + __pmsg_write(destination, content); +} + +// How much of the temp log we have copied to the copy in cache. +static off_t tmplog_offset = 0; + +void reset_tmplog_offset() { + tmplog_offset = 0; +} + +static void copy_log_file(const std::string& source, const std::string& destination, bool append, + const selabel_handle* sehandle) { + FILE* dest_fp = fopen_path(destination, append ? "ae" : "we", sehandle); + if (dest_fp == nullptr) { + PLOG(ERROR) << "Can't open " << destination; + } else { + FILE* source_fp = fopen(source.c_str(), "re"); + if (source_fp != nullptr) { + if (append) { + fseeko(source_fp, tmplog_offset, SEEK_SET); // Since last write + } + char buf[4096]; + size_t bytes; + while ((bytes = fread(buf, 1, sizeof(buf), source_fp)) != 0) { + fwrite(buf, 1, bytes, dest_fp); + } + if (append) { + tmplog_offset = ftello(source_fp); + } + check_and_fclose(source_fp, source); + } + check_and_fclose(dest_fp, destination); + } +} + +void copy_logs(bool save_current_log, bool has_cache, const selabel_handle* sehandle) { + // We only rotate and record the log of the current session if explicitly requested. This usually + // happens after wipes, installation from BCB or menu selections. This is to avoid unnecessary + // rotation (and possible deletion) of log files, if it does not do anything loggable. + if (!save_current_log) { + return; + } + + // Always write to pmsg, this allows the OTA logs to be caught in `logcat -L`. + copy_log_file_to_pmsg(Paths::Get().temporary_log_file(), LAST_LOG_FILE); + copy_log_file_to_pmsg(Paths::Get().temporary_install_file(), LAST_INSTALL_FILE); + + // We can do nothing for now if there's no /cache partition. + if (!has_cache) { + return; + } + + ensure_path_mounted(LAST_LOG_FILE); + ensure_path_mounted(LAST_KMSG_FILE); + rotate_logs(LAST_LOG_FILE, LAST_KMSG_FILE); + + // Copy logs to cache so the system can find out what happened. + copy_log_file(Paths::Get().temporary_log_file(), LOG_FILE, true, sehandle); + copy_log_file(Paths::Get().temporary_log_file(), LAST_LOG_FILE, false, sehandle); + copy_log_file(Paths::Get().temporary_install_file(), LAST_INSTALL_FILE, false, sehandle); + save_kernel_log(LAST_KMSG_FILE); + chmod(LOG_FILE, 0600); + chown(LOG_FILE, AID_SYSTEM, AID_SYSTEM); + chmod(LAST_KMSG_FILE, 0600); + chown(LAST_KMSG_FILE, AID_SYSTEM, AID_SYSTEM); + chmod(LAST_LOG_FILE, 0640); + chmod(LAST_INSTALL_FILE, 0644); + chown(LAST_INSTALL_FILE, AID_SYSTEM, AID_SYSTEM); + sync(); +} + +// Read from kernel log into buffer and write out to file. +void save_kernel_log(const char* destination) { + int klog_buf_len = klogctl(KLOG_SIZE_BUFFER, 0, 0); + if (klog_buf_len <= 0) { + PLOG(ERROR) << "Error getting klog size"; + return; + } + + std::string buffer(klog_buf_len, 0); + int n = klogctl(KLOG_READ_ALL, &buffer[0], klog_buf_len); + if (n == -1) { + PLOG(ERROR) << "Error in reading klog"; + return; + } + buffer.resize(n); + android::base::WriteStringToFile(buffer, destination); +} |