logd: Add klogd

- Add a klogd to collect the kernel logs and place them into a
  new kernel log buffer
- Parse priority, tag and message from the kernel log messages.
- Turn off pruning for worst UID for the kernel log buffer
- Sniff for 'PM: suspend exit', 'PM: suspend enter' and
  'Suspended for' messages and correct the internal definition
  time correction against monotonic dynamically.
- Discern if we have monotonic or real time (delineation 1980) in
  audit messages.
- perform appropriate math to correct the timestamp to be real time
- filter out any external sources of kernel logging

Change-Id: I8d4c7c5ac19f1f3218079ee3a05a50e2ca55f60d
diff --git a/logd/LogKlog.h b/logd/LogKlog.h
new file mode 100644
index 0000000..8de9c87
--- /dev/null
+++ b/logd/LogKlog.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2014 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.
+ */
+
+#ifndef _LOGD_LOG_KLOG_H__
+#define _LOGD_LOG_KLOG_H__
+
+#include <sysutils/SocketListener.h>
+#include <log/log_read.h>
+#include "LogReader.h"
+
+class LogKlog : public SocketListener {
+    LogBuffer *logbuf;
+    LogReader *reader;
+    const log_time signature;
+    const int fdWrite; // /dev/kmsg
+    const int fdRead;  // /proc/kmsg
+    // Set once thread is started, separates KLOG_ACTION_READ_ALL
+    // and KLOG_ACTION_READ phases.
+    bool initialized;
+    // Used during each of the above phases to control logging.
+    bool enableLogging;
+    // set if we are also running auditd, to filter out audit reports from
+    // our copy of the kernel log
+    bool auditd;
+
+    static log_time correction;
+
+public:
+    LogKlog(LogBuffer *buf, LogReader *reader, int fdWrite, int fdRead, bool auditd);
+    int log(const char *buf);
+    void synchronize(const char *buf);
+
+    static void convertMonotonicToReal(log_time &real) { real += correction; }
+
+protected:
+    void sniffTime(log_time &now, const char **buf, bool reverse);
+    void calculateCorrection(const log_time &monotonic, const char *real_string);
+    virtual bool onDataAvailable(SocketClient *cli);
+
+};
+
+#endif