Collect and send kernel crash diagnostics

crash_collector.cc

+// 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/crash_collector.h"
+
+#include <pwd.h>  // For struct passwd.
+#include <sys/types.h>  // for mode_t.
+
+#include "base/file_util.h"
+#include "base/logging.h"
+#include "base/string_util.h"
+#include "crash-reporter/system_logging.h"
+
+static const char kDefaultUserName[] = "chronos";
+static const char kSystemCrashPath[] = "/var/spool/crash";
+static const char kUserCrashPath[] = "/home/chronos/user/crash";
+
+// Directory mode of the user crash spool directory.
+static const mode_t kUserCrashPathMode = 0755;
+
+// Directory mode of the system crash spool directory.
+static const mode_t kSystemCrashPathMode = 01755;
+
+static const uid_t kRootOwner = 0;
+static const uid_t kRootGroup = 0;
+
+CrashCollector::CrashCollector() : forced_crash_directory_(NULL) {
+}
+
+CrashCollector::~CrashCollector() {
+}
+
+void CrashCollector::Initialize(
+    CrashCollector::CountCrashFunction count_crash_function,
+    CrashCollector::IsFeedbackAllowedFunction is_feedback_allowed_function,
+    SystemLogging *logger) {
+  CHECK(count_crash_function != NULL);
+  CHECK(is_feedback_allowed_function != NULL);
+  CHECK(logger != NULL);
+
+  count_crash_function_ = count_crash_function;
+  is_feedback_allowed_function_ = is_feedback_allowed_function;
+  logger_ = logger;
+}
+
+std::string CrashCollector::FormatDumpBasename(const std::string &exec_name,
+                                               time_t timestamp,
+                                               pid_t pid) {
+  struct tm tm;
+  localtime_r(&timestamp, &tm);
+  return StringPrintf("%s.%04d%02d%02d.%02d%02d%02d.%d",
+                      exec_name.c_str(),
+                      tm.tm_year + 1900,
+                      tm.tm_mon + 1,
+                      tm.tm_mday,
+                      tm.tm_hour,
+                      tm.tm_min,
+                      tm.tm_sec,
+                      pid);
+}
+
+FilePath CrashCollector::GetCrashDirectoryInfo(
+    uid_t process_euid,
+    uid_t default_user_id,
+    gid_t default_user_group,
+    mode_t *mode,
+    uid_t *directory_owner,
+    gid_t *directory_group) {
+  if (process_euid == default_user_id) {
+    *mode = kUserCrashPathMode;
+    *directory_owner = default_user_id;
+    *directory_group = default_user_group;
+    return FilePath(kUserCrashPath);
+  } else {
+    *mode = kSystemCrashPathMode;
+    *directory_owner = kRootOwner;
+    *directory_group = kRootGroup;
+    return FilePath(kSystemCrashPath);
+  }
+}
+
+bool CrashCollector::GetUserInfoFromName(const std::string &name,
+                                         uid_t *uid,
+                                         gid_t *gid) {
+  char storage[256];
+  struct passwd passwd_storage;
+  struct passwd *passwd_result = NULL;
+
+  if (getpwnam_r(name.c_str(), &passwd_storage, storage, sizeof(storage),
+                 &passwd_result) != 0 || passwd_result == NULL) {
+    logger_->LogError("Cannot find user named %s", name.c_str());
+    return false;
+  }
+
+  *uid = passwd_result->pw_uid;
+  *gid = passwd_result->pw_gid;
+  return true;
+}
+
+bool CrashCollector::GetCreatedCrashDirectoryByEuid(uid_t euid,
+                                                    FilePath *crash_directory) {
+  uid_t default_user_id;
+  gid_t default_user_group;
+
+  // For testing.
+  if (forced_crash_directory_ != NULL) {
+    *crash_directory = FilePath(forced_crash_directory_);
+    return true;
+  }
+
+  if (!GetUserInfoFromName(kDefaultUserName,
+                           &default_user_id,
+                           &default_user_group)) {
+    logger_->LogError("Could not find default user info");
+    return false;
+  }
+  mode_t directory_mode;
+  uid_t directory_owner;
+  gid_t directory_group;
+  *crash_directory =
+      GetCrashDirectoryInfo(euid,
+                            default_user_id,
+                            default_user_group,
+                            &directory_mode,
+                            &directory_owner,
+                            &directory_group);
+
+  if (!file_util::PathExists(*crash_directory)) {
+    // Create the spool directory with the appropriate mode (regardless of
+    // umask) and ownership.
+    mode_t old_mask = umask(0);
+    if (mkdir(crash_directory->value().c_str(), directory_mode) < 0 ||
+        chown(crash_directory->value().c_str(),
+              directory_owner,
+              directory_group) < 0) {
+      logger_->LogError("Unable to create appropriate crash directory");
+      return false;
+    }
+    umask(old_mask);
+  }
+
+  if (!file_util::PathExists(*crash_directory)) {
+    logger_->LogError("Unable to create crash directory %s",
+                      crash_directory->value().c_str());
+    return false;
+  }
+
+  return true;
+}