utmp log file, Linux/glibc version: Java parsing library

KS implementation details

License: CC0-1.0

References

This page hosts a formal specification of utmp log file, Linux/glibc version using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.

Usage

Runtime library

All parsing code for Java generated by Kaitai Struct depends on the Java runtime library. You have to install it before you can parse data.

The Java runtime library is published in the Maven Central Repository. Refer to the artifact page for instructions how to add it into your project with the build tool that you use.

Code

Parse a local file and get structure in memory:

GlibcUtmp data = GlibcUtmp.fromFile("path/to/local/file.utmp log file, Linux/glibc version");

Or parse structure from a byte array:

byte[] someArray = new byte[] { ... };
GlibcUtmp data = new GlibcUtmp(new ByteBufferKaitaiStream(someArray));

After that, one can get various attributes from the structure by invoking getter methods like:

data.records() // => get records

Java source code to parse utmp log file, Linux/glibc version

GlibcUtmp.java

// This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

import io.kaitai.struct.ByteBufferKaitaiStream;
import io.kaitai.struct.KaitaiStruct;
import io.kaitai.struct.KaitaiStream;
import java.io.IOException;
import java.util.Map;
import java.util.HashMap;
import java.util.ArrayList;
import java.nio.charset.Charset;

public class GlibcUtmp extends KaitaiStruct {
    public static GlibcUtmp fromFile(String fileName) throws IOException {
        return new GlibcUtmp(new ByteBufferKaitaiStream(fileName));
    }

    public enum EntryType {
        EMPTY(0),
        RUN_LVL(1),
        BOOT_TIME(2),
        NEW_TIME(3),
        OLD_TIME(4),
        INIT_PROCESS(5),
        LOGIN_PROCESS(6),
        USER_PROCESS(7),
        DEAD_PROCESS(8),
        ACCOUNTING(9);

        private final long id;
        EntryType(long id) { this.id = id; }
        public long id() { return id; }
        private static final Map<Long, EntryType> byId = new HashMap<Long, EntryType>(10);
        static {
            for (EntryType e : EntryType.values())
                byId.put(e.id(), e);
        }
        public static EntryType byId(long id) { return byId.get(id); }
    }

    public GlibcUtmp(KaitaiStream _io) {
        this(_io, null, null);
    }

    public GlibcUtmp(KaitaiStream _io, KaitaiStruct _parent) {
        this(_io, _parent, null);
    }

    public GlibcUtmp(KaitaiStream _io, KaitaiStruct _parent, GlibcUtmp _root) {
        super(_io);
        this._parent = _parent;
        this._root = _root == null ? this : _root;
        _read();
    }
    private void _read() {
        this._raw_records = new ArrayList<byte[]>();
        this.records = new ArrayList<Record>();
        {
            int i = 0;
            while (!this._io.isEof()) {
                this._raw_records.add(this._io.readBytes(384));
                KaitaiStream _io__raw_records = new ByteBufferKaitaiStream(_raw_records.get(_raw_records.size() - 1));
                this.records.add(new Record(_io__raw_records, this, _root));
                i++;
            }
        }
    }
    public static class Record extends KaitaiStruct {
        public static Record fromFile(String fileName) throws IOException {
            return new Record(new ByteBufferKaitaiStream(fileName));
        }

        public Record(KaitaiStream _io) {
            this(_io, null, null);
        }

        public Record(KaitaiStream _io, GlibcUtmp _parent) {
            this(_io, _parent, null);
        }

        public Record(KaitaiStream _io, GlibcUtmp _parent, GlibcUtmp _root) {
            super(_io);
            this._parent = _parent;
            this._root = _root;
            _read();
        }
        private void _read() {
            this.utType = GlibcUtmp.EntryType.byId(this._io.readS4le());
            this.pid = this._io.readU4le();
            this.line = new String(this._io.readBytes(32), Charset.forName("UTF-8"));
            this.id = new String(this._io.readBytes(4), Charset.forName("UTF-8"));
            this.user = new String(this._io.readBytes(32), Charset.forName("UTF-8"));
            this.host = new String(this._io.readBytes(256), Charset.forName("UTF-8"));
            this.exit = this._io.readU4le();
            this.session = this._io.readS4le();
            this.tv = new Timeval(this._io, this, _root);
            this.addrV6 = this._io.readBytes(16);
            this.reserved = this._io.readBytes(20);
        }
        private EntryType utType;
        private long pid;
        private String line;
        private String id;
        private String user;
        private String host;
        private long exit;
        private int session;
        private Timeval tv;
        private byte[] addrV6;
        private byte[] reserved;
        private GlibcUtmp _root;
        private GlibcUtmp _parent;

        /**
         * Type of login
         */
        public EntryType utType() { return utType; }

        /**
         * Process ID of login process
         */
        public long pid() { return pid; }

        /**
         * Devicename
         */
        public String line() { return line; }

        /**
         * Inittab ID
         */
        public String id() { return id; }

        /**
         * Username
         */
        public String user() { return user; }

        /**
         * Hostname for remote login
         */
        public String host() { return host; }

        /**
         * Exit status of a process marked as DEAD_PROCESS
         */
        public long exit() { return exit; }

        /**
         * Session ID, used for windowing
         */
        public int session() { return session; }

        /**
         * Time entry was made
         */
        public Timeval tv() { return tv; }

        /**
         * Internet address of remote host
         */
        public byte[] addrV6() { return addrV6; }
        public byte[] reserved() { return reserved; }
        public GlibcUtmp _root() { return _root; }
        public GlibcUtmp _parent() { return _parent; }
    }
    public static class Timeval extends KaitaiStruct {
        public static Timeval fromFile(String fileName) throws IOException {
            return new Timeval(new ByteBufferKaitaiStream(fileName));
        }

        public Timeval(KaitaiStream _io) {
            this(_io, null, null);
        }

        public Timeval(KaitaiStream _io, GlibcUtmp.Record _parent) {
            this(_io, _parent, null);
        }

        public Timeval(KaitaiStream _io, GlibcUtmp.Record _parent, GlibcUtmp _root) {
            super(_io);
            this._parent = _parent;
            this._root = _root;
            _read();
        }
        private void _read() {
            this.sec = this._io.readS4le();
            this.usec = this._io.readS4le();
        }
        private int sec;
        private int usec;
        private GlibcUtmp _root;
        private GlibcUtmp.Record _parent;

        /**
         * Seconds
         */
        public int sec() { return sec; }

        /**
         * Microseconds
         */
        public int usec() { return usec; }
        public GlibcUtmp _root() { return _root; }
        public GlibcUtmp.Record _parent() { return _parent; }
    }
    private ArrayList<Record> records;
    private GlibcUtmp _root;
    private KaitaiStruct _parent;
    private ArrayList<byte[]> _raw_records;
    public ArrayList<Record> records() { return records; }
    public GlibcUtmp _root() { return _root; }
    public KaitaiStruct _parent() { return _parent; }
    public ArrayList<byte[]> _raw_records() { return _raw_records; }
}