From 3236432c39f1d5a1bbbe362c5cfdb088756fd04f Mon Sep 17 00:00:00 2001 From: Florian Schmaus Date: Sun, 8 Jun 2014 13:18:46 +0200 Subject: Make minidns Android agnostic there is really no need for minidns to be Android exclusive. Replacing the Android log API with JUL make minidns available for Android and Java SE. --- src/main/java/de/measite/minidns/Client.java | 290 ++++++++++++ src/main/java/de/measite/minidns/DNSMessage.java | 507 +++++++++++++++++++++ src/main/java/de/measite/minidns/Question.java | 62 +++ src/main/java/de/measite/minidns/Record.java | 297 ++++++++++++ src/main/java/de/measite/minidns/record/A.java | 37 ++ src/main/java/de/measite/minidns/record/AAAA.java | 43 ++ src/main/java/de/measite/minidns/record/CNAME.java | 44 ++ src/main/java/de/measite/minidns/record/Data.java | 16 + src/main/java/de/measite/minidns/record/NS.java | 12 + src/main/java/de/measite/minidns/record/SRV.java | 74 +++ .../java/de/measite/minidns/util/NameUtil.java | 91 ++++ 11 files changed, 1473 insertions(+) create mode 100644 src/main/java/de/measite/minidns/Client.java create mode 100644 src/main/java/de/measite/minidns/DNSMessage.java create mode 100644 src/main/java/de/measite/minidns/Question.java create mode 100644 src/main/java/de/measite/minidns/Record.java create mode 100644 src/main/java/de/measite/minidns/record/A.java create mode 100644 src/main/java/de/measite/minidns/record/AAAA.java create mode 100644 src/main/java/de/measite/minidns/record/CNAME.java create mode 100644 src/main/java/de/measite/minidns/record/Data.java create mode 100644 src/main/java/de/measite/minidns/record/NS.java create mode 100644 src/main/java/de/measite/minidns/record/SRV.java create mode 100644 src/main/java/de/measite/minidns/util/NameUtil.java (limited to 'src/main/java') diff --git a/src/main/java/de/measite/minidns/Client.java b/src/main/java/de/measite/minidns/Client.java new file mode 100644 index 00000000..fb42cd25 --- /dev/null +++ b/src/main/java/de/measite/minidns/Client.java @@ -0,0 +1,290 @@ +package de.measite.minidns; + +import java.io.IOException; +import java.io.InputStream; +import java.io.InputStreamReader; +import java.io.LineNumberReader; +import java.lang.reflect.Method; +import java.net.DatagramPacket; +import java.net.DatagramSocket; +import java.net.InetAddress; +import java.security.NoSuchAlgorithmException; +import java.security.SecureRandom; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.HashSet; +import java.util.Random; +import java.util.logging.Logger; + +import de.measite.minidns.Record.CLASS; +import de.measite.minidns.Record.TYPE; + +/** + * A minimal DNS client for SRV/A/AAAA/NS and CNAME lookups, with IDN support. + * This circumvents the missing javax.naming package on android. + */ +public class Client { + + private static final Logger LOGGER = Logger.getLogger(Client.class.getName()); + + /** + * The internal random class for sequence generation. + */ + protected Random random; + + /** + * The buffer size for dns replies. + */ + protected int bufferSize = 1500; + + /** + * DNS timeout. + */ + protected int timeout = 5000; + + /** + * Create a new DNS client. + */ + public Client() { + try { + random = SecureRandom.getInstance("SHA1PRNG"); + } catch (NoSuchAlgorithmException e1) { + random = new SecureRandom(); + } + } + + /** + * Query a nameserver for a single entry. + * @param name The DNS name to request. + * @param type The DNS type to request (SRV, A, AAAA, ...). + * @param clazz The class of the request (usually IN for Internet). + * @param host The DNS server host. + * @param port The DNS server port. + * @return + * @throws IOException On IO Errors. + */ + public DNSMessage query(String name, TYPE type, CLASS clazz, String host, int port) + throws IOException + { + Question q = new Question(); + q.setClazz(clazz); + q.setType(type); + q.setName(name); + return query(q, host, port); + } + + /** + * Query a nameserver for a single entry. + * @param name The DNS name to request. + * @param type The DNS type to request (SRV, A, AAAA, ...). + * @param clazz The class of the request (usually IN for Internet). + * @param host The DNS server host. + * @return + * @throws IOException On IO Errors. + */ + public DNSMessage query(String name, TYPE type, CLASS clazz, String host) + throws IOException + { + Question q = new Question(); + q.setClazz(clazz); + q.setType(type); + q.setName(name); + return query(q, host); + } + + /** + * Query the system nameserver for a single entry. + * @param name The DNS name to request. + * @param type The DNS type to request (SRV, A, AAAA, ...). + * @param clazz The class of the request (usually IN for Internet). + * @return The DNSMessage reply or null. + */ + public DNSMessage query(String name, TYPE type, CLASS clazz) + { + Question q = new Question(); + q.setClazz(clazz); + q.setType(type); + q.setName(name); + return query(q); + } + + /** + * Query a specific server for one entry. + * @param q The question section of the DNS query. + * @param host The dns server host. + * @throws IOException On IOErrors. + */ + public DNSMessage query(Question q, String host) throws IOException { + return query(q, host, 53); + } + + /** + * Query a specific server for one entry. + * @param q The question section of the DNS query. + * @param host The dns server host. + * @param port the dns port. + * @throws IOException On IOErrors. + */ + public DNSMessage query(Question q, String host, int port) throws IOException { + DNSMessage message = new DNSMessage(); + message.setQuestions(new Question[]{q}); + message.setRecursionDesired(true); + message.setId(random.nextInt()); + byte[] buf = message.toArray(); + DatagramSocket socket = new DatagramSocket(); + DatagramPacket packet = new DatagramPacket( + buf, buf.length, InetAddress.getByName(host), port); + socket.setSoTimeout(timeout); + socket.send(packet); + packet = new DatagramPacket(new byte[bufferSize], bufferSize); + socket.receive(packet); + DNSMessage dnsMessage = DNSMessage.parse(packet.getData()); + if (dnsMessage.getId() != message.getId()) { + return null; + } + return dnsMessage; + } + + /** + * Query the system DNS server for one entry. + * @param q The question section of the DNS query. + */ + public DNSMessage query(Question q) { + String dnsServer[] = findDNS(); + for (String dns : dnsServer) { + try { + DNSMessage message = query(q, dns); + if (message == null) { + continue; + } + if (message.getResponseCode() != + DNSMessage.RESPONSE_CODE.NO_ERROR) { + continue; + } + for (Record record: message.getAnswers()) { + if (record.isAnswer(q)) { + return message; + } + } + } catch (IOException ioe) { + } + } + return null; + } + + /** + * Retrieve a list of currently configured DNS servers. + * @return The server array. + */ + public String[] findDNS() { + String[] result = findDNSByReflection(); + if (result != null) { + LOGGER.fine("Got DNS servers via reflection: " + Arrays.toString(result)); + return result; + } + + result = findDNSByExec(); + if (result != null) { + LOGGER.fine("Got DNS servers via exec: " + Arrays.toString(result)); + return result; + } + + // fallback for ipv4 and ipv6 connectivity + // see https://developers.google.com/speed/public-dns/docs/using + LOGGER.fine("No DNS found? Using fallback [8.8.8.8, [2001:4860:4860::8888]]"); + + return new String[]{"8.8.8.8", "[2001:4860:4860::8888]"}; + } + + /** + * Try to retrieve the list of dns server by executing getprop. + * @return Array of servers, or null on failure. + */ + protected String[] findDNSByExec() { + try { + Process process = Runtime.getRuntime().exec("getprop"); + InputStream inputStream = process.getInputStream(); + LineNumberReader lnr = new LineNumberReader( + new InputStreamReader(inputStream)); + String line = null; + HashSet server = new HashSet(6); + while ((line = lnr.readLine()) != null) { + int split = line.indexOf("]: ["); + if (split == -1) { + continue; + } + String property = line.substring(1, split); + String value = line.substring(split + 4, line.length() - 1); + if (property.endsWith(".dns") || property.endsWith(".dns1") || + property.endsWith(".dns2") || property.endsWith(".dns3") || + property.endsWith(".dns4")) { + + // normalize the address + + InetAddress ip = InetAddress.getByName(value); + + if (ip == null) continue; + + value = ip.getHostAddress(); + + if (value == null) continue; + if (value.length() == 0) continue; + + server.add(value); + } + } + if (server.size() > 0) { + return server.toArray(new String[server.size()]); + } + } catch (IOException e) { + e.printStackTrace(); + } + return null; + } + + /** + * Try to retrieve the list of dns server by calling SystemProperties. + * @return Array of servers, or null on failure. + */ + protected String[] findDNSByReflection() { + try { + Class SystemProperties = + Class.forName("android.os.SystemProperties"); + Method method = SystemProperties.getMethod("get", + new Class[] { String.class }); + + ArrayList servers = new ArrayList(5); + + for (String propKey : new String[] { + "net.dns1", "net.dns2", "net.dns3", "net.dns4"}) { + + String value = (String)method.invoke(null, propKey); + + if (value == null) continue; + if (value.length() == 0) continue; + if (servers.contains(value)) continue; + + InetAddress ip = InetAddress.getByName(value); + + if (ip == null) continue; + + value = ip.getHostAddress(); + + if (value == null) continue; + if (value.length() == 0) continue; + if (servers.contains(value)) continue; + + servers.add(value); + } + + if (servers.size() > 0) { + return servers.toArray(new String[servers.size()]); + } + } catch (Exception e) { + // we might trigger some problems this way + e.printStackTrace(); + } + return null; + } + +} diff --git a/src/main/java/de/measite/minidns/DNSMessage.java b/src/main/java/de/measite/minidns/DNSMessage.java new file mode 100644 index 00000000..14c8f04b --- /dev/null +++ b/src/main/java/de/measite/minidns/DNSMessage.java @@ -0,0 +1,507 @@ +package de.measite.minidns; + +import java.io.ByteArrayInputStream; +import java.io.ByteArrayOutputStream; +import java.io.DataInputStream; +import java.io.DataOutputStream; +import java.io.IOException; +import java.util.Arrays; + +/** + * A DNS message as defined by rfc1035. The message consists of a header and + * 4 sections: question, answer, nameserver and addition resource record + * section. + * A message can either be parsed ({@see #parse(byte[])}) or serialized + * ({@see #toArray()}). + */ +public class DNSMessage { + + /** + * Possible DNS reply codes. + */ + public static enum RESPONSE_CODE { + NO_ERROR(0), FORMAT_ERR(1), SERVER_FAIL(2), NX_DOMAIN(3), + NO_IMP(4), REFUSED(5), YXDOMAIN(6), YXRRSET(7), + NXRRSET(8), NOT_AUTH(9),NOT_ZONE(10); + + /** + * Reverse lookup table for response codes. + */ + private final static RESPONSE_CODE INVERSE_LUT[] = new RESPONSE_CODE[]{ + NO_ERROR, FORMAT_ERR, SERVER_FAIL, NX_DOMAIN, NO_IMP, + REFUSED, YXDOMAIN, YXRRSET, NXRRSET, NOT_AUTH, NOT_ZONE, + null, null, null, null, null + }; + + /** + * The response code value. + */ + private final byte value; + + /** + * Create a new response code. + * @param value The response code value. + */ + private RESPONSE_CODE(int value) { + this.value = (byte)value; + } + + /** + * Retrieve the byte value of the response code. + * @return + */ + public byte getValue() { + return (byte) value; + } + + /** + * Retrieve the response code for a byte value. + * @param value The byte value. + * @return The symbolic response code or null. + * @throws IllegalArgumentException if the value is not in the range of + * 0..15. + */ + public static RESPONSE_CODE getResponseCode(int value) { + if (value < 0 || value > 15) { + throw new IllegalArgumentException(); + } + return INVERSE_LUT[value]; + } + + }; + + /** + * Symbolic DNS Opcode values. + */ + public static enum OPCODE { + QUERY(0), + INVERSE_QUERY(1), + STATUS(2), + NOTIFY(4), + UPDATE(5); + + /** + * Lookup table for for obcode reolution. + */ + private final static OPCODE INVERSE_LUT[] = new OPCODE[]{ + QUERY, INVERSE_QUERY, STATUS, null, NOTIFY, UPDATE, null, + null, null, null, null, null, null, null, null + }; + + /** + * The value of this opcode. + */ + private final byte value; + + /** + * Create a new opcode for a given byte value. + * @param value The byte value of the opcode. + */ + private OPCODE(int value) { + this.value = (byte)value; + } + + /** + * Retrieve the byte value of this opcode. + * @return The byte value of this opcode. + */ + public byte getValue() { + return value; + } + + /** + * Retrieve the symbolic name of an opcode byte. + * @param value The byte value of the opcode. + * @return The symbolic opcode or null. + * @throws IllegalArgumentException If the byte value is not in the + * range 0..15. + */ + public static OPCODE getOpcode(int value) { + if (value < 0 || value > 15) { + throw new IllegalArgumentException(); + } + return INVERSE_LUT[value]; + } + + }; + + /** + * The DNS message id. + */ + protected int id; + + /** + * The DNS message opcode. + */ + protected OPCODE opcode; + + /** + * The response code of this dns message. + */ + protected RESPONSE_CODE responseCode; + + /** + * True if this is a query. + */ + protected boolean query; + + /** + * True if this is a authorative response. + */ + protected boolean authoritativeAnswer; + + /** + * True on truncate, tcp should be used. + */ + protected boolean truncated; + + /** + * True if the server should recurse. + */ + protected boolean recursionDesired; + + /** + * True if recursion is possible. + */ + protected boolean recursionAvailable; + + /** + * True if the server regarded the response as authentic. + */ + protected boolean authenticData; + + /** + * True if the server should not check the replies. + */ + protected boolean checkDisabled; + + /** + * The question section content. + */ + protected Question questions[]; + + /** + * The answers section content. + */ + protected Record answers[]; + + /** + * The nameserver records. + */ + protected Record nameserverRecords[]; + + /** + * Additional resousrce records. + */ + protected Record additionalResourceRecords[]; + + /** + * Retrieve the current DNS message id. + * @return The current DNS message id. + */ + public int getId() { + return id; + } + + /** + * Set the current DNS message id. + * @param id The new DNS message id. + */ + public void setId(int id) { + this.id = id & 0xffff; + } + + /** + * Retrieve the query type (true or false; + * @return True if this DNS message is a query. + */ + public boolean isQuery() { + return query; + } + + /** + * Set the query status of this message. + * @param query The new query status. + */ + public void setQuery(boolean query) { + this.query = query; + } + + /** + * True if the DNS message is an authoritative answer. + * @return True if this an authoritative DNS message. + */ + public boolean isAuthoritativeAnswer() { + return authoritativeAnswer; + } + + /** + * Set the authoritative answer flag. + * @param authoritativeAnswer Tge new authoritative answer value. + */ + public void setAuthoritativeAnswer(boolean authoritativeAnswer) { + this.authoritativeAnswer = authoritativeAnswer; + } + + /** + * Retrieve the truncation status of this message. True means that the + * client should try a tcp lookup. + * @return True if this message was truncated. + */ + public boolean isTruncated() { + return truncated; + } + + /** + * Set the truncation bit on this DNS message. + * @param truncated The new truncated bit status. + */ + public void setTruncated(boolean truncated) { + this.truncated = truncated; + } + + /** + * Check if this message preferes recursion. + * @return True if recursion is desired. + */ + public boolean isRecursionDesired() { + return recursionDesired; + } + + /** + * Set the recursion desired flag on this message. + * @param recursionDesired The new recusrion setting. + */ + public void setRecursionDesired(boolean recursionDesired) { + this.recursionDesired = recursionDesired; + } + + /** + * Retrieve the recursion available flag of this DNS message. + * @return The recursion available flag of this message. + */ + public boolean isRecursionAvailable() { + return recursionAvailable; + } + + /** + * Set the recursion available flog from this DNS message. + * @param recursionAvailable The new recursion available status. + */ + public void setRecursionAvailable(boolean recursionAvailable) { + this.recursionAvailable = recursionAvailable; + } + + /** + * Retrieve the authentic data flag of this message. + * @return The authentic data flag. + */ + public boolean isAuthenticData() { + return authenticData; + } + + /** + * Set the authentic data flag on this DNS message. + * @param authenticData The new authentic data flag value. + */ + public void setAuthenticData(boolean authenticData) { + this.authenticData = authenticData; + } + + /** + * Check if checks are disabled. + * @return The status of the CheckDisabled flag. + */ + public boolean isCheckDisabled() { + return checkDisabled; + } + + /** + * Change the check status of this packet. + * @param checkDisabled + */ + public void setCheckDisabled(boolean checkDisabled) { + this.checkDisabled = checkDisabled; + } + + /** + * Generate a binary dns packet out of this message. + * @return byte[] the binary representation. + * @throws IOException Should never happen. + */ + public byte[] toArray() throws IOException { + ByteArrayOutputStream baos = new ByteArrayOutputStream(512); + DataOutputStream dos = new DataOutputStream(baos); + int header = 0; + if (query) { + header += 1 << 15; + } + if (opcode != null) { + header += opcode.getValue() << 11; + } + if (authoritativeAnswer) { + header += 1 << 10; + } + if (truncated) { + header += 1 << 9; + } + if (recursionDesired) { + header += 1 << 8; + } + if (recursionAvailable) { + header += 1 << 7; + } + if (authenticData) { + header += 1 << 5; + } + if (checkDisabled) { + header += 1 << 4; + } + if (responseCode != null) { + header += responseCode.getValue(); + } + dos.writeShort((short)id); + dos.writeShort((short)header); + if (questions == null) { + dos.writeShort(0); + } else { + dos.writeShort((short)questions.length); + } + if (answers == null) { + dos.writeShort(0); + } else { + dos.writeShort((short)answers.length); + } + if (nameserverRecords == null) { + dos.writeShort(0); + } else { + dos.writeShort((short)nameserverRecords.length); + } + if (additionalResourceRecords == null) { + dos.writeShort(0); + } else { + dos.writeShort((short)additionalResourceRecords.length); + } + for (Question question: questions) { + dos.write(question.toByteArray()); + } + dos.flush(); + return baos.toByteArray(); + } + + /** + * Build a DNS Message based on a binary DNS message. + * @param data The DNS message data. + * @return Parsed DNSMessage message. + * @throws IOException On read errors. + */ + public static DNSMessage parse(byte data[]) throws IOException { + ByteArrayInputStream bis = new ByteArrayInputStream(data); + DataInputStream dis = new DataInputStream(bis); + DNSMessage message = new DNSMessage(); + message.id = dis.readUnsignedShort(); + int header = dis.readUnsignedShort(); + message.query = ((header >> 15) & 1) == 0; + message.opcode = OPCODE.getOpcode((header >> 11) & 0xf); + message.authoritativeAnswer = ((header >> 10) & 1) == 1; + message.truncated = ((header >> 9) & 1) == 1; + message.recursionDesired = ((header >> 8) & 1) == 1; + message.recursionAvailable = ((header >> 7) & 1) == 1; + message.authenticData = ((header >> 5) & 1) == 1; + message.checkDisabled = ((header >> 4) & 1) == 1; + message.responseCode = RESPONSE_CODE.getResponseCode(header & 0xf); + int questionCount = dis.readUnsignedShort(); + int answerCount = dis.readUnsignedShort(); + int nameserverCount = dis.readUnsignedShort(); + int additionalResourceRecordCount = dis.readUnsignedShort(); + message.questions = new Question[questionCount]; + while (questionCount-- > 0) { + Question q = new Question(); + q.parse(dis, data); + message.questions[questionCount] = q; + } + message.answers = new Record[answerCount]; + while (answerCount-- > 0) { + Record rr = new Record(); + rr.parse(dis, data); + message.answers[answerCount] = rr; + } + message.nameserverRecords = new Record[nameserverCount]; + while (nameserverCount-- > 0) { + Record rr = new Record(); + rr.parse(dis, data); + message.nameserverRecords[nameserverCount] = rr; + } + message.additionalResourceRecords = + new Record[additionalResourceRecordCount]; + while (additionalResourceRecordCount-- > 0) { + Record rr = new Record(); + rr.parse(dis, data); + message.additionalResourceRecords[additionalResourceRecordCount] = + rr; + } + return message; + } + + /** + * Set the question part of this message. + * @param questions The questions. + */ + public void setQuestions(Question ... questions) { + this.questions = questions; + } + + /** + * Retrieve the opcode of this message. + * @return The opcode of this message. + */ + public OPCODE getOpcode() { + return opcode; + } + + /** + * Retrieve the response code of this message. + * @return The response code. + */ + public RESPONSE_CODE getResponseCode() { + return responseCode; + } + + /** + * Retrieve the question section of this message. + * @return The DNS question section. + */ + public Question[] getQuestions() { + return questions; + } + + /** + * Retrieve the answer records of this DNS message. + * @return The answer section of this DNS message. + */ + public Record[] getAnswers() { + return answers; + } + + /** + * Retrieve the nameserver records of this DNS message. + * @return The nameserver section of this DNS message. + */ + public Record[] getNameserverRecords() { + return nameserverRecords; + } + + /** + * Retrieve the additional resource records attached to this DNS message. + * @return The additional resource record section of this DNS message. + */ + public Record[] getAdditionalResourceRecords() { + return additionalResourceRecords; + } + + public String toString() { + return "-- DNSMessage " + id + " --\n" + + Arrays.toString(answers); + } + +} diff --git a/src/main/java/de/measite/minidns/Question.java b/src/main/java/de/measite/minidns/Question.java new file mode 100644 index 00000000..9d1e3f56 --- /dev/null +++ b/src/main/java/de/measite/minidns/Question.java @@ -0,0 +1,62 @@ +package de.measite.minidns; + +import java.io.ByteArrayOutputStream; +import java.io.DataInputStream; +import java.io.DataOutputStream; +import java.io.IOException; + +import de.measite.minidns.Record.CLASS; +import de.measite.minidns.Record.TYPE; +import de.measite.minidns.util.NameUtil; + +public class Question { + + private String name; + + private TYPE type; + + private CLASS clazz = CLASS.IN; + + public TYPE getType() { + return type; + } + + public void setType(TYPE type) { + this.type = type; + } + + public CLASS getClazz() { + return clazz; + } + + public void setClazz(CLASS clazz) { + this.clazz = clazz; + } + + public String getName() { + return name; + } + + public void setName(String name) { + this.name = name; + } + + public void parse(DataInputStream dis, byte[] data) throws IOException { + this.name = NameUtil.parse(dis, data); + this.type = TYPE.getType(dis.readUnsignedShort()); + this.clazz = CLASS.getClass(dis.readUnsignedShort()); + } + + public byte[] toByteArray() throws IOException { + ByteArrayOutputStream baos = new ByteArrayOutputStream(512); + DataOutputStream dos = new DataOutputStream(baos); + + dos.write(NameUtil.toByteArray(this.name)); + dos.writeShort(type.getValue()); + dos.writeShort(clazz.getValue()); + + dos.flush(); + return baos.toByteArray(); + } + +} diff --git a/src/main/java/de/measite/minidns/Record.java b/src/main/java/de/measite/minidns/Record.java new file mode 100644 index 00000000..fb0b5d5f --- /dev/null +++ b/src/main/java/de/measite/minidns/Record.java @@ -0,0 +1,297 @@ +package de.measite.minidns; + +import java.io.DataInputStream; +import java.io.IOException; +import java.util.HashMap; + +import de.measite.minidns.record.A; +import de.measite.minidns.record.AAAA; +import de.measite.minidns.record.CNAME; +import de.measite.minidns.record.Data; +import de.measite.minidns.record.NS; +import de.measite.minidns.record.SRV; +import de.measite.minidns.util.NameUtil; + +/** + * A generic DNS record. + */ +public class Record { + + /** + * The record type. + * {@see http://www.iana.org/assignments/dns-parameters} + */ + public static enum TYPE { + A(1), + NS(2), + MD(3), + MF(4), + CNAME(5), + SOA(6), + MB(7), + MG(8), + MR(9), + NULL(10), + WKS(11), + PTR(12), + HINFO(13), + MINFO(14), + MX(15), + TXT(16), + RP(17), + AFSDB(18), + X25(19), + ISDN(20), + RT(21), + NSAP(22), + NSAP_PTR(23), + SIG(24), + KEY(25), + PX(26), + GPOS(27), + AAAA(28), + LOC(29), + NXT(30), + EID(31), + NIMLOC(32), + SRV(33), + ATMA(34), + NAPTR(35), + KX(36), + CERT(37), + A6(38), + DNAME(39), + SINK(40), + OPT(41), + APL(42), + DS(43), + SSHFP(44), + IPSECKEY(45), + RRSIG(46), + NSEC(47), + DNSKEY(48), + DHCID(49), + NSEC3(50), + NSEC3PARAM(51), + HIP(55), + NINFO(56), + RKEY(57), + TALINK(58), + SPF(99), + UINFO(100), + UID(101), + GID(102), + TKEY(249), + TSIG(250), + IXFR(251), + AXFR(252), + MAILB(253), + MAILA(254), + ANY(255), + TA(32768), + DLV(32769); + + /** + * The value of this DNS record type. + */ + private final int value; + + /** + * Internal lookup table to map values to types. + */ + private final static HashMap INVERSE_LUT = + new HashMap(); + + /** + * Initialize the reverse lookup table. + */ + static { + for(TYPE t: TYPE.values()) { + INVERSE_LUT.put(t.getValue(), t); + } + } + + /** + * Create a new record type. + * @param value The binary value of this type. + */ + private TYPE(int value) { + this.value = value; + } + + /** + * Retrieve the binary value of this type. + * @return The binary value. + */ + public int getValue() { + return value; + } + + /** + * Retrieve the symbolic type of the binary value. + * @param value The binary type value. + * @return The symbolic tpye. + */ + public static TYPE getType(int value) { + return INVERSE_LUT.get(value); + } + }; + + /** + * The symbolic class of a DNS record (usually IN for Internet). + */ + public static enum CLASS { + IN(1), + CH(3), + HS(4), + NONE(254), + ANY(255); + + /** + * Internal reverse lookup table to map binary class values to symbolic + * names. + */ + private final static HashMap INVERSE_LUT = + new HashMap(); + + /** + * Initialize the interal reverse lookup table. + */ + static { + for(CLASS c: CLASS.values()) { + INVERSE_LUT.put(c.getValue(), c); + } + } + + /** + * The binary value of this dns class. + */ + private final int value; + + /** + * Create a new DNS class based on a binary value. + * @param value The binary value of this DNS class. + */ + private CLASS(int value) { + this.value = value; + } + + /** + * Retrieve the binary value of this DNS class. + * @return The binary value of this DNS class. + */ + public int getValue() { + return value; + } + + /** + * Retrieve the symbolic DNS class for a binary class value. + * @param value The binary DNS class value. + * @return The symbolic class instance. + */ + public static CLASS getClass(int value) { + return INVERSE_LUT.get(value); + } + + } + + /** + * The generic name of this record. + */ + protected String name; + + /** + * The type (and payload type) of this record. + */ + protected TYPE type; + + /** + * The record class (usually CLASS.IN). + */ + protected CLASS clazz; + + /** + * The ttl of this record. + */ + protected long ttl; + + /** + * The payload object of this record. + */ + protected Data payloadData; + + /** + * Parse a given record based on the full message data and the current + * stream position. + * @param dis The DataInputStream positioned at the first record byte. + * @param data The full message data. + * @throws IOException In case of malformed replies. + */ + public void parse(DataInputStream dis, byte[] data) throws IOException { + this.name = NameUtil.parse(dis, data); + this.type = TYPE.getType(dis.readUnsignedShort()); + this.clazz = CLASS.getClass(dis.readUnsignedShort()); + this.ttl = (((long)dis.readUnsignedShort()) << 32) + + dis.readUnsignedShort(); + int payloadLength = dis.readUnsignedShort(); + switch (this.type) { + case SRV: + this.payloadData = new SRV(); + break; + case AAAA: + this.payloadData = new AAAA(); + break; + case A: + this.payloadData = new A(); + break; + case NS: + this.payloadData = new NS(); + break; + case CNAME: + this.payloadData = new CNAME(); + break; + default: + System.out.println("Unparsed type " + type); + this.payloadData = null; + for (int i = 0; i < payloadLength; i++) { + dis.readByte(); + } + break; + } + if (this.payloadData != null) { + this.payloadData.parse(dis, data, payloadLength); + } + } + + /** + * Retrieve a textual representation of this resource record. + * @return String + */ + @Override + public String toString() { + if (payloadData == null) { + return "RR " + type + "/" + clazz; + } + return "RR " + type + "/" + clazz + ": " + payloadData.toString(); + }; + + /** + * Check if this record answers a given query. + * @param q The query. + * @return True if this record is a valid answer. + */ + public boolean isAnswer(Question q) { + return ((q.getType() == type) || (q.getType() == TYPE.ANY)) && + ((q.getClazz() == clazz) || (q.getClazz() == CLASS.ANY)) && + (q.getName().equals(name)); + } + + public String getName() { + return name; + } + + public Data getPayload() { + return payloadData; + } + +} diff --git a/src/main/java/de/measite/minidns/record/A.java b/src/main/java/de/measite/minidns/record/A.java new file mode 100644 index 00000000..a85a7af0 --- /dev/null +++ b/src/main/java/de/measite/minidns/record/A.java @@ -0,0 +1,37 @@ +package de.measite.minidns.record; + +import java.io.DataInputStream; +import java.io.IOException; + +import de.measite.minidns.Record.TYPE; + +public class A implements Data { + + private byte[] ip; + + @Override + public TYPE getType() { + return TYPE.A; + } + + @Override + public byte[] toByteArray() { + return ip; + } + + @Override + public void parse(DataInputStream dis, byte[] data, int length) + throws IOException { + ip = new byte[4]; + dis.readFully(ip); + } + + @Override + public String toString() { + return Integer.toString(ip[0] & 0xff) + "." + + Integer.toString(ip[1] & 0xff) + "." + + Integer.toString(ip[2] & 0xff) + "." + + Integer.toString(ip[3] & 0xff); + } + +} diff --git a/src/main/java/de/measite/minidns/record/AAAA.java b/src/main/java/de/measite/minidns/record/AAAA.java new file mode 100644 index 00000000..d89147b2 --- /dev/null +++ b/src/main/java/de/measite/minidns/record/AAAA.java @@ -0,0 +1,43 @@ +package de.measite.minidns.record; + +import java.io.DataInputStream; +import java.io.IOException; + +import de.measite.minidns.Record.TYPE; + +public class AAAA implements Data { + + private byte[] ip; + + @Override + public TYPE getType() { + return TYPE.AAAA; + } + + @Override + public byte[] toByteArray() { + return ip; + } + + @Override + public void parse(DataInputStream dis, byte[] data, int length) + throws IOException { + ip = new byte[16]; + dis.readFully(ip); + } + + @Override + public String toString() { + StringBuilder sb = new StringBuilder(); + for (int i = 0; i < ip.length; i += 2) { + if (i != 0) { + sb.append(':'); + } + sb.append(Integer.toHexString( + ((ip[i] & 0xff) << 8) + (ip[i + 1] & 0xff) + )); + } + return sb.toString(); + } + +} diff --git a/src/main/java/de/measite/minidns/record/CNAME.java b/src/main/java/de/measite/minidns/record/CNAME.java new file mode 100644 index 00000000..4657b4a5 --- /dev/null +++ b/src/main/java/de/measite/minidns/record/CNAME.java @@ -0,0 +1,44 @@ +package de.measite.minidns.record; + +import java.io.DataInputStream; +import java.io.IOException; + +import de.measite.minidns.Record.TYPE; +import de.measite.minidns.util.NameUtil; + +public class CNAME implements Data { + + protected String name; + + public String getName() { + return name; + } + + public void setName(String name) { + this.name = name; + } + + @Override + public byte[] toByteArray() { + // TODO Auto-generated method stub + return null; + } + + @Override + public void parse(DataInputStream dis, byte[] data, int length) + throws IOException + { + this.name = NameUtil.parse(dis, data); + } + + @Override + public TYPE getType() { + return TYPE.CNAME; + } + + @Override + public String toString() { + return "to \"" + name + "\""; + } + +} diff --git a/src/main/java/de/measite/minidns/record/Data.java b/src/main/java/de/measite/minidns/record/Data.java new file mode 100644 index 00000000..9cb80374 --- /dev/null +++ b/src/main/java/de/measite/minidns/record/Data.java @@ -0,0 +1,16 @@ +package de.measite.minidns.record; + +import java.io.DataInputStream; +import java.io.IOException; + +import de.measite.minidns.Record.TYPE; + +public interface Data { + + TYPE getType(); + + byte[] toByteArray(); + + void parse(DataInputStream dis, byte data[], int length) throws IOException; + +} diff --git a/src/main/java/de/measite/minidns/record/NS.java b/src/main/java/de/measite/minidns/record/NS.java new file mode 100644 index 00000000..bf07e8c4 --- /dev/null +++ b/src/main/java/de/measite/minidns/record/NS.java @@ -0,0 +1,12 @@ +package de.measite.minidns.record; + +import de.measite.minidns.Record.TYPE; + +public class NS extends CNAME { + + @Override + public TYPE getType() { + return TYPE.NS; + } + +} diff --git a/src/main/java/de/measite/minidns/record/SRV.java b/src/main/java/de/measite/minidns/record/SRV.java new file mode 100644 index 00000000..32b70c4d --- /dev/null +++ b/src/main/java/de/measite/minidns/record/SRV.java @@ -0,0 +1,74 @@ +package de.measite.minidns.record; + +import java.io.DataInputStream; +import java.io.IOException; + +import de.measite.minidns.Record.TYPE; +import de.measite.minidns.util.NameUtil; + +public class SRV implements Data { + + protected int priority; + protected int weight; + protected int port; + protected String name; + + public int getPriority() { + return priority; + } + + public void setPriority(int priority) { + this.priority = priority; + } + + public int getWeight() { + return weight; + } + + public void setWeight(int weight) { + this.weight = weight; + } + + public int getPort() { + return port; + } + + public void setPort(int port) { + this.port = port; + } + + public String getName() { + return name; + } + + public void setName(String name) { + this.name = name; + } + + @Override + public byte[] toByteArray() { + // TODO Auto-generated method stub + return null; + } + + @Override + public void parse(DataInputStream dis, byte[] data, int length) + throws IOException + { + this.priority = dis.readUnsignedShort(); + this.weight = dis.readUnsignedShort(); + this.port = dis.readUnsignedShort(); + this.name = NameUtil.parse(dis, data); + } + + @Override + public String toString() { + return "SRV " + name + ":" + port + " p:" + priority + " w:" + weight; + } + + @Override + public TYPE getType() { + return TYPE.SRV; + } + +} diff --git a/src/main/java/de/measite/minidns/util/NameUtil.java b/src/main/java/de/measite/minidns/util/NameUtil.java new file mode 100644 index 00000000..91a6649d --- /dev/null +++ b/src/main/java/de/measite/minidns/util/NameUtil.java @@ -0,0 +1,91 @@ +package de.measite.minidns.util; + +import java.io.ByteArrayOutputStream; +import java.io.DataInputStream; +import java.io.DataOutputStream; +import java.io.IOException; +import java.net.IDN; +import java.util.HashSet; +import java.util.Arrays; + +public class NameUtil { + + public static int size(String name) { + return name.length() + 2; + } + + public static boolean idnEquals(String name1, String name2) { + if (name1 == name2) return true; // catches null, null + if (name1 == null) return false; + if (name2 == null) return false; + if (name1.equals(name2)) return true; + + try { + return Arrays.equals(toByteArray(name1),toByteArray(name2)); + } catch (IOException e) { + return false; // impossible + } + } + + public static byte[] toByteArray(String name) throws IOException { + ByteArrayOutputStream baos = new ByteArrayOutputStream(64); + DataOutputStream dos = new DataOutputStream(baos); + for (String s: name.split("[.\u3002\uFF0E\uFF61]")) { + byte[] buffer = IDN.toASCII(s).getBytes(); + dos.writeByte(buffer.length); + dos.write(buffer); + } + dos.writeByte(0); + dos.flush(); + return baos.toByteArray(); + } + + public static String parse(DataInputStream dis, byte data[]) + throws IOException + { + int c = dis.readUnsignedByte(); + if ((c & 0xc0) == 0xc0) { + c = ((c & 0x3f) << 8) + dis.readUnsignedByte(); + HashSet jumps = new HashSet(); + jumps.add(c); + return parse(data, c, jumps); + } + if (c == 0) { + return ""; + } + byte b[] = new byte[c]; + dis.readFully(b); + String s = IDN.toUnicode(new String(b)); + String t = parse(dis, data); + if (t.length() > 0) { + s = s + "." + t; + } + return s; + } + + public static String parse( + byte data[], + int offset, + HashSet jumps + ) { + int c = data[offset] & 0xff; + if ((c & 0xc0) == 0xc0) { + c = ((c & 0x3f) << 8) + (data[offset + 1] & 0xff); + if (jumps.contains(c)) { + throw new IllegalStateException("Cyclic offsets detected."); + } + jumps.add(c); + return parse(data, c, jumps); + } + if (c == 0) { + return ""; + } + String s = new String(data,offset + 1, c); + String t = parse(data, offset + 1 + c, jumps); + if (t.length() > 0) { + s = s + "." + t; + } + return s; + } + +} -- cgit v1.2.3 From defe51910153ed6a9aaf6becae9e6484bed609bd Mon Sep 17 00:00:00 2001 From: Florian Schmaus Date: Sun, 8 Jun 2014 13:33:14 +0200 Subject: Close DatagramSocket using try-with-resources --- src/main/java/de/measite/minidns/Client.java | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) (limited to 'src/main/java') diff --git a/src/main/java/de/measite/minidns/Client.java b/src/main/java/de/measite/minidns/Client.java index fb42cd25..e20c007e 100644 --- a/src/main/java/de/measite/minidns/Client.java +++ b/src/main/java/de/measite/minidns/Client.java @@ -131,18 +131,19 @@ public class Client { message.setRecursionDesired(true); message.setId(random.nextInt()); byte[] buf = message.toArray(); - DatagramSocket socket = new DatagramSocket(); - DatagramPacket packet = new DatagramPacket( - buf, buf.length, InetAddress.getByName(host), port); - socket.setSoTimeout(timeout); - socket.send(packet); - packet = new DatagramPacket(new byte[bufferSize], bufferSize); - socket.receive(packet); - DNSMessage dnsMessage = DNSMessage.parse(packet.getData()); - if (dnsMessage.getId() != message.getId()) { - return null; + try (DatagramSocket socket = new DatagramSocket()) { + DatagramPacket packet = new DatagramPacket(buf, buf.length, + InetAddress.getByName(host), port); + socket.setSoTimeout(timeout); + socket.send(packet); + packet = new DatagramPacket(new byte[bufferSize], bufferSize); + socket.receive(packet); + DNSMessage dnsMessage = DNSMessage.parse(packet.getData()); + if (dnsMessage.getId() != message.getId()) { + return null; + } + return dnsMessage; } - return dnsMessage; } /** -- cgit v1.2.3 From 315648382ec2b1fd59c36e388e0fae5d23b3b9a6 Mon Sep 17 00:00:00 2001 From: Florian Schmaus Date: Sun, 8 Jun 2014 13:54:51 +0200 Subject: Remove printStackTrace() calls it's hard to assign those an app in the Android log. Better to use JUL. --- src/main/java/de/measite/minidns/Client.java | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'src/main/java') diff --git a/src/main/java/de/measite/minidns/Client.java b/src/main/java/de/measite/minidns/Client.java index e20c007e..b5712d24 100644 --- a/src/main/java/de/measite/minidns/Client.java +++ b/src/main/java/de/measite/minidns/Client.java @@ -14,6 +14,7 @@ import java.util.ArrayList; import java.util.Arrays; import java.util.HashSet; import java.util.Random; +import java.util.logging.Level; import java.util.logging.Logger; import de.measite.minidns.Record.CLASS; @@ -238,7 +239,7 @@ public class Client { return server.toArray(new String[server.size()]); } } catch (IOException e) { - e.printStackTrace(); + LOGGER.log(Level.WARNING, "Exception in findDNSByExec", e); } return null; } @@ -283,7 +284,7 @@ public class Client { } } catch (Exception e) { // we might trigger some problems this way - e.printStackTrace(); + LOGGER.log(Level.WARNING, "Exception in findDNSByReflection", e); } return null; } -- cgit v1.2.3 From 52807fe7c415e9977cd2d7191b7e1251c9216256 Mon Sep 17 00:00:00 2001 From: Florian Schmaus Date: Sun, 8 Jun 2014 13:57:50 +0200 Subject: Log IOException --- src/main/java/de/measite/minidns/Client.java | 1 + 1 file changed, 1 insertion(+) (limited to 'src/main/java') diff --git a/src/main/java/de/measite/minidns/Client.java b/src/main/java/de/measite/minidns/Client.java index b5712d24..cad3902a 100644 --- a/src/main/java/de/measite/minidns/Client.java +++ b/src/main/java/de/measite/minidns/Client.java @@ -169,6 +169,7 @@ public class Client { } } } catch (IOException ioe) { + LOGGER.log(Level.FINE, "IOException in query", ioe); } } return null; -- cgit v1.2.3