| // Copyright (c) 2010 The Chromium OS Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "crash-reporter/user_collector.h" |
| |
| #include <grp.h> // For struct group. |
| #include <pwd.h> // For struct passwd. |
| #include <sys/types.h> // For getpwuid_r, getgrnam_r, WEXITSTATUS. |
| |
| #include <string> |
| #include <vector> |
| |
| #include "base/file_util.h" |
| #include "base/logging.h" |
| #include "base/string_util.h" |
| #include "crash-reporter/system_logging.h" |
| #include "gflags/gflags.h" |
| |
| #pragma GCC diagnostic ignored "-Wstrict-aliasing" |
| DEFINE_bool(core2md_failure_test, false, "Core2md failure test"); |
| DEFINE_bool(directory_failure_test, false, "Spool directory failure test"); |
| DEFINE_string(filter_in, "", |
| "Ignore all crashes but this for testing"); |
| #pragma GCC diagnostic error "-Wstrict-aliasing" |
| |
| static const char kCollectionErrorSignature[] = |
| "crash_reporter-user-collection"; |
| // This procfs file is used to cause kernel core file writing to |
| // instead pipe the core file into a user space process. See |
| // core(5) man page. |
| static const char kCorePatternFile[] = "/proc/sys/kernel/core_pattern"; |
| static const char kCoreToMinidumpConverterPath[] = "/usr/bin/core2md"; |
| static const char kLeaveCoreFile[] = "/root/.leave_core"; |
| |
| const char *UserCollector::kUserId = "Uid:\t"; |
| const char *UserCollector::kGroupId = "Gid:\t"; |
| |
| UserCollector::UserCollector() |
| : generate_diagnostics_(false), |
| core_pattern_file_(kCorePatternFile), |
| initialized_(false) { |
| } |
| |
| void UserCollector::Initialize( |
| UserCollector::CountCrashFunction count_crash_function, |
| const std::string &our_path, |
| UserCollector::IsFeedbackAllowedFunction is_feedback_allowed_function, |
| SystemLogging *logger, |
| bool generate_diagnostics) { |
| CrashCollector::Initialize(count_crash_function, |
| is_feedback_allowed_function, |
| logger); |
| our_path_ = our_path; |
| initialized_ = true; |
| generate_diagnostics_ = generate_diagnostics; |
| } |
| |
| UserCollector::~UserCollector() { |
| } |
| |
| std::string UserCollector::GetPattern(bool enabled) const { |
| if (enabled) { |
| return StringPrintf("|%s --signal=%%s --pid=%%p", our_path_.c_str()); |
| } else { |
| return "core"; |
| } |
| } |
| |
| bool UserCollector::SetUpInternal(bool enabled) { |
| CHECK(initialized_); |
| logger_->LogInfo("%s user crash handling", |
| enabled ? "Enabling" : "Disabling"); |
| std::string pattern = GetPattern(enabled); |
| if (file_util::WriteFile(FilePath(core_pattern_file_), |
| pattern.c_str(), |
| pattern.length()) != |
| static_cast<int>(pattern.length())) { |
| logger_->LogError("Unable to write %s", core_pattern_file_.c_str()); |
| return false; |
| } |
| return true; |
| } |
| |
| FilePath UserCollector::GetProcessPath(pid_t pid) { |
| return FilePath(StringPrintf("/proc/%d", pid)); |
| } |
| |
| bool UserCollector::GetSymlinkTarget(const FilePath &symlink, |
| FilePath *target) { |
| int max_size = 32; |
| scoped_array<char> buffer; |
| while (true) { |
| buffer.reset(new char[max_size + 1]); |
| ssize_t size = readlink(symlink.value().c_str(), buffer.get(), max_size); |
| if (size < 0) { |
| return false; |
| } |
| buffer[size] = 0; |
| if (size == max_size) { |
| // Avoid overflow when doubling. |
| if (max_size * 2 > max_size) { |
| max_size *= 2; |
| continue; |
| } else { |
| return false; |
| } |
| } |
| break; |
| } |
| |
| *target = FilePath(buffer.get()); |
| return true; |
| } |
| |
| bool UserCollector::GetExecutableBaseNameFromPid(uid_t pid, |
| std::string *base_name) { |
| FilePath target; |
| if (!GetSymlinkTarget(GetProcessPath(pid).Append("exe"), &target)) |
| return false; |
| *base_name = target.BaseName().value(); |
| return true; |
| } |
| |
| bool UserCollector::GetIdFromStatus(const char *prefix, |
| IdKind kind, |
| const std::string &status_contents, |
| int *id) { |
| // From fs/proc/array.c:task_state(), this file contains: |
| // \nUid:\t<uid>\t<euid>\t<suid>\t<fsuid>\n |
| std::vector<std::string> status_lines; |
| SplitString(status_contents, '\n', &status_lines); |
| std::vector<std::string>::iterator line_iterator; |
| for (line_iterator = status_lines.begin(); |
| line_iterator != status_lines.end(); |
| ++line_iterator) { |
| if (line_iterator->find(prefix) == 0) |
| break; |
| } |
| if (line_iterator == status_lines.end()) { |
| return false; |
| } |
| std::string id_substring = line_iterator->substr(strlen(prefix), |
| std::string::npos); |
| std::vector<std::string> ids; |
| SplitString(id_substring, '\t', &ids); |
| if (ids.size() != kIdMax || kind < 0 || kind >= kIdMax) { |
| return false; |
| } |
| const char *number = ids[kind].c_str(); |
| char *end_number = NULL; |
| *id = strtol(number, &end_number, 10); |
| if (*end_number != '\0') |
| return false; |
| return true; |
| } |
| |
| void UserCollector::LogCollectionError(const std::string &error_message) { |
| error_log_.append(error_message.c_str()); |
| error_log_.append("\n"); |
| logger_->LogError(error_message.c_str()); |
| } |
| |
| void UserCollector::EnqueueCollectionErrorLog(pid_t pid, |
| const std::string &exec) { |
| FilePath crash_path; |
| logger_->LogInfo("Writing conversion problems as separate crash report."); |
| if (!GetCreatedCrashDirectoryByEuid(0, &crash_path, NULL)) { |
| logger_->LogError("Could not even get log directory; out of space?"); |
| return; |
| } |
| std::string dump_basename = FormatDumpBasename(exec, time(NULL), pid); |
| FilePath log_path = GetCrashPath(crash_path, dump_basename, "log"); |
| FilePath meta_path = GetCrashPath(crash_path, dump_basename, "meta"); |
| // We must use WriteNewFile instead of file_util::WriteFile as we do |
| // not want to write with root access to a symlink that an attacker |
| // might have created. |
| WriteNewFile(log_path, error_log_.data(), error_log_.length()); |
| AddCrashMetaData("sig", kCollectionErrorSignature); |
| WriteCrashMetaData(meta_path, exec, log_path.value()); |
| } |
| |
| bool UserCollector::CopyOffProcFiles(pid_t pid, |
| const FilePath &container_dir) { |
| if (!file_util::CreateDirectory(container_dir)) { |
| LogCollectionError(StringPrintf("Could not create %s", |
| container_dir.value().c_str())); |
| return false; |
| } |
| FilePath process_path = GetProcessPath(pid); |
| if (!file_util::PathExists(process_path)) { |
| LogCollectionError(StringPrintf("Path %s does not exist", |
| process_path.value().c_str())); |
| return false; |
| } |
| static const char *proc_files[] = { |
| "auxv", |
| "cmdline", |
| "environ", |
| "maps", |
| "status" |
| }; |
| for (unsigned i = 0; i < arraysize(proc_files); ++i) { |
| if (!file_util::CopyFile(process_path.Append(proc_files[i]), |
| container_dir.Append(proc_files[i]))) { |
| LogCollectionError(StringPrintf("Could not copy %s file", |
| proc_files[i])); |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| bool UserCollector::GetCreatedCrashDirectory(pid_t pid, |
| FilePath *crash_file_path, |
| bool *out_of_capacity) { |
| FilePath process_path = GetProcessPath(pid); |
| std::string status; |
| if (FLAGS_directory_failure_test) { |
| LogCollectionError("Purposefully failing to create spool directory"); |
| return false; |
| } |
| if (!file_util::ReadFileToString(process_path.Append("status"), |
| &status)) { |
| LogCollectionError("Could not read status file"); |
| return false; |
| } |
| int process_euid; |
| if (!GetIdFromStatus(kUserId, kIdEffective, status, &process_euid)) { |
| LogCollectionError("Could not find euid in status file"); |
| return false; |
| } |
| if (!GetCreatedCrashDirectoryByEuid(process_euid, |
| crash_file_path, |
| out_of_capacity)) { |
| LogCollectionError("Could not create crash directory"); |
| return false; |
| } |
| return true; |
| } |
| |
| bool UserCollector::CopyStdinToCoreFile(const FilePath &core_path) { |
| // Copy off all stdin to a core file. |
| FilePath stdin_path("/dev/fd/0"); |
| if (file_util::CopyFile(stdin_path, core_path)) { |
| return true; |
| } |
| |
| LogCollectionError("Could not write core file"); |
| // If the file system was full, make sure we remove any remnants. |
| file_util::Delete(core_path, false); |
| return false; |
| } |
| |
| bool UserCollector::RunCoreToMinidump(const FilePath &core_path, |
| const FilePath &procfs_directory, |
| const FilePath &minidump_path, |
| const FilePath &temp_directory) { |
| FilePath output_path = temp_directory.Append("output"); |
| std::vector<const char *> core2md_arguments; |
| core2md_arguments.push_back(kCoreToMinidumpConverterPath); |
| core2md_arguments.push_back(core_path.value().c_str()); |
| core2md_arguments.push_back(procfs_directory.value().c_str()); |
| core2md_arguments.push_back(minidump_path.value().c_str()); |
| |
| if (FLAGS_core2md_failure_test) { |
| // To test how core2md errors are propagaged, cause an error |
| // by forgetting a required argument. |
| core2md_arguments.pop_back(); |
| } |
| |
| int errorlevel = ForkExecAndPipe(core2md_arguments, |
| output_path.value().c_str()); |
| |
| std::string output; |
| file_util::ReadFileToString(output_path, &output); |
| if (errorlevel != 0) { |
| LogCollectionError(StringPrintf("Problem during %s [result=%d]: %s", |
| kCoreToMinidumpConverterPath, |
| errorlevel, |
| output.c_str())); |
| return false; |
| } |
| |
| if (!file_util::PathExists(minidump_path)) { |
| LogCollectionError(StringPrintf("Minidump file %s was not created", |
| minidump_path.value().c_str())); |
| return false; |
| } |
| return true; |
| } |
| |
| bool UserCollector::ConvertCoreToMinidump(pid_t pid, |
| const FilePath &container_dir, |
| const FilePath &core_path, |
| const FilePath &minidump_path) { |
| if (!CopyOffProcFiles(pid, container_dir)) { |
| return false; |
| } |
| |
| if (!CopyStdinToCoreFile(core_path)) { |
| return false; |
| } |
| |
| bool conversion_result = RunCoreToMinidump( |
| core_path, |
| container_dir, // procfs directory |
| minidump_path, |
| container_dir); // temporary directory |
| |
| if (conversion_result) { |
| logger_->LogInfo("Stored minidump to %s", minidump_path.value().c_str()); |
| } |
| |
| return conversion_result; |
| } |
| |
| bool UserCollector::ConvertAndEnqueueCrash(int pid, |
| const std::string &exec, |
| bool *out_of_capacity) { |
| FilePath crash_path; |
| if (!GetCreatedCrashDirectory(pid, &crash_path, out_of_capacity)) { |
| LogCollectionError("Unable to find/create process-specific crash path"); |
| return false; |
| } |
| |
| // Directory like /tmp/crash_reporter.1234 which contains the |
| // procfs entries and other temporary files used during conversion. |
| FilePath container_dir = FilePath("/tmp").Append( |
| StringPrintf("crash_reporter.%d", pid)); |
| std::string dump_basename = FormatDumpBasename(exec, time(NULL), pid); |
| FilePath core_path = GetCrashPath(crash_path, dump_basename, "core"); |
| FilePath meta_path = GetCrashPath(crash_path, dump_basename, "meta"); |
| FilePath minidump_path = GetCrashPath(crash_path, dump_basename, "dmp"); |
| |
| if (!ConvertCoreToMinidump(pid, container_dir, core_path, |
| minidump_path)) { |
| logger_->LogInfo("Leaving core file at %s due to conversion error", |
| core_path.value().c_str()); |
| return false; |
| } |
| |
| // Here we commit to sending this file. We must not return false |
| // after this point or we will generate a log report as well as a |
| // crash report. |
| WriteCrashMetaData(meta_path, |
| exec, |
| minidump_path.value()); |
| |
| if (!file_util::PathExists(FilePath(kLeaveCoreFile))) { |
| file_util::Delete(core_path, false); |
| } else { |
| logger_->LogInfo("Leaving core file at %s due to developer image", |
| core_path.value().c_str()); |
| } |
| |
| file_util::Delete(container_dir, true); |
| return true; |
| } |
| |
| bool UserCollector::HandleCrash(int signal, int pid, const char *force_exec) { |
| CHECK(initialized_); |
| std::string exec; |
| if (force_exec) { |
| exec.assign(force_exec); |
| } else if (!GetExecutableBaseNameFromPid(pid, &exec)) { |
| // If for some reason we don't have the base name, avoid completely |
| // failing by indicating an unknown name. |
| exec = "unknown"; |
| } |
| |
| // Allow us to test the crash reporting mechanism successfully even if |
| // other parts of the system crash. |
| if (!FLAGS_filter_in.empty() && |
| (FLAGS_filter_in == "none" || |
| FLAGS_filter_in != exec)) { |
| // We use a different format message to make it more obvious in tests |
| // which crashes are test generated and which are real. |
| logger_->LogWarning("Ignoring crash from %s[%d] while filter_in=%s", |
| exec.c_str(), pid, FLAGS_filter_in.c_str()); |
| return true; |
| } |
| |
| bool feedback = is_feedback_allowed_function_(); |
| logger_->LogWarning("Received crash notification for %s[%d] sig %d (%s)", |
| exec.c_str(), pid, signal, |
| feedback ? "handling" : "ignoring - no consent"); |
| |
| if (feedback) { |
| count_crash_function_(); |
| |
| if (generate_diagnostics_) { |
| bool out_of_capacity = false; |
| if (!ConvertAndEnqueueCrash(pid, exec, &out_of_capacity)) { |
| if (!out_of_capacity) |
| EnqueueCollectionErrorLog(pid, exec); |
| return false; |
| } |
| } |
| } |
| |
| return true; |
| } |