io.pkts.packet.sip.impl.SipInitialLine Maven / Gradle / Ivy
/**
*
*/
package io.pkts.packet.sip.impl;
import io.pkts.buffer.Buffer;
import io.pkts.buffer.ByteNotFoundException;
import io.pkts.packet.sip.SipMessage;
import io.pkts.packet.sip.SipParseException;
import java.io.IOException;
/**
* @author [email protected]
*/
public abstract class SipInitialLine extends SipParser {
protected SipInitialLine() {
// left empty intentionally
}
/**
* Two initial lines are considered equal if:
*
* - They are both a request or response line
* - If response, their status codes are the same (the human readable
* reason is ignored)
* - If request, the request-uri must be equal according to the rules
* of URI equality
*
* @param other
* @return
*/
public abstract boolean equals(final Object other);
/**
* The request initial line as a raw buffer.
*
* @return
*/
public abstract Buffer getBuffer();
/**
* Simple method to check whether the supplied buffer could be a SIP
* response line. Hence, does it start with SIP/2.0 or not. Note, if this
* method returns false it does not necessarily mean that this is a request
* line but if you have already determined that that the incoming data could
* be a SIP message (e.g. by using the method
* {@link SipFramer#couldBeSipMessage(Buffer)}) then it is very likely that
* it is a request line.
*
* @return
* @throws IOException
* @throws IndexOutOfBoundsException
*/
public static boolean isResponseLine(final Buffer buffer) throws IOException {
if (buffer == null || buffer.getReadableBytes() < 7) {
return false;
}
final byte a = buffer.getByte(0);
final byte b = buffer.getByte(1);
final byte c = buffer.getByte(2);
final byte d = buffer.getByte(3);
final byte e = buffer.getByte(4);
final byte f = buffer.getByte(5);
final byte g = buffer.getByte(6);
return a == 'S' && b == 'I' && c == 'P' && d == '/' && e == '2' && f == '.' && g == '0';
}
/**
* Parse the buffer into a SIP initial line, which either can be a
* {@link SipRequestLine} or a {@link SipResponseLine}.
*
* The parsing will only check so that a few things are correct but in
* general it doesn't do any deeper analysis of the initial line. To make
* sure that the resulting sip message actually is correct, call the
* {@link SipMessage#verify()} method, which will do a deeper analysis of
* the sip message
*
* @param buffer
* @return
*/
public static final SipInitialLine parse(final Buffer buffer) throws SipParseException {
Buffer part1 = null;
Buffer part2 = null;
Buffer part3 = null;
try {
part1 = buffer.readUntil(SipParser.SP);
part2 = buffer.readUntil(SipParser.SP);
part3 = buffer.readLine();
if (SipParser.SIP2_0.equals(part1)) {
final int statusCode = part2.parseToInt();
return new SipResponseLine(statusCode, part3);
}
// not a response so then the last part must be the SIP/2.0
// otherwise this is not a valid SIP initial line
expectSIP2_0(part3);
return new SipRequestLine(part1, part2);
} catch (final NumberFormatException e) {
final int index = buffer.getReaderIndex() - part3.capacity() - part2.capacity() - 1;
throw new SipParseException(index, "unable to parse the SIP response code as an integer");
} catch (final ByteNotFoundException e) {
throw new SipParseException(buffer.getReaderIndex(), "expected space");
} catch (final SipParseException e) {
// is only thrown by the expectSIP2_0. Calculate the correct
// index into the buffer
e.printStackTrace();;
final int index = buffer.getReaderIndex() - part3.capacity() + e.getErrorOffset() - 1;
throw new SipParseException(index, "Wrong SIP version");
} catch (final IOException e) {
throw new SipParseException(buffer.getReaderIndex(), "could not read from stream", e);
}
}
public static final SipInitialLine parse(final Buffer part1, final Buffer part2, final Buffer part3) throws SipParseException {
try {
if (SipParser.SIP2_0.equals(part1)) {
final int statusCode = part2.parseToInt();
return new SipResponseLine(statusCode, part3);
}
// not a response so then the last part must be the SIP/2.0
// otherwise this is not a valid SIP initial line
expectSIP2_0(part3);
return new SipRequestLine(part1, part2);
} catch (final NumberFormatException e) {
throw new SipParseException(part1.capacity() + 1, "unable to parse the SIP response code as an integer");
} catch (final SipParseException e) {
// is only thrown by the expectSIP2_0. Calculate the correct
// index into the buffer
throw new SipParseException(part1.capacity() + 1 + part2.capacity() + 1, "Wrong SIP version");
} catch (final IOException e) {
throw new SipParseException(0, "could not read from stream", e);
}
}
public SipRequestLine toRequestLine() {
throw new ClassCastException("Cannot cast object to " + SipRequestLine.class);
}
public SipResponseLine toResponseLine() {
throw new ClassCastException("Cannot cast object to " + SipResponseLine.class);
}
public boolean isResponseLine() {
return false;
}
public boolean isRequestLine() {
return false;
}
/**
* Write the bytes representing this {@link SipInitialLine} into the
* destination {@link Buffer}.
*
* @param dst
*/
public abstract void getBytes(Buffer dst);
@Override
protected abstract SipInitialLine clone();
}