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java.lang.Object
   |
   +----edu.utah.janos.nodeos.pj_DemultiplexKey
           |
           +----edu.utah.janos.nodeos.DemultiplexKey

Summary

public class  DemultiplexKey
     extends edu.utah.janos.nodeos.pj_DemultiplexKey
{
          // Constructors 1
     public DemultiplexKey(Flow);

          // Methods 8
     pj_DemultiplexKey getNativeKey();
     public void match(int, int, byte[], boolean[]);
     public void matchANEP(int, byte, boolean, short);
     public void matchIPv4(int, int, int, int);
     public void matchTCP(int, int, int);
     public void matchUDP(int, int, int);
     public final int matches(byte[], int, int);
     public String toString();
}

A key for matching incoming packets.

Author:

Janos Ministry of Development

See Also: InChannel, CutThroughChannel

Cross Reference

Extended By:

ANEPDemultiplexKey, StdinTest.StdinDemultiplexKey, SimpleDemultiplexKey

   public DemultiplexKey(Flow flow) 

Create a new demultiplex key. By default, the key is empty (matches anything, or everything, I don't remember.)

   public void match(int offset, 
                     int length, 
                     byte[] sequence, 
                     boolean[] mask) 

Add a segment that matches the given sequence of bytes at the given offset in the packet. The mask says which bytes of sequence are relevant. If mask is null, all bytes are relevant.

XXX currently mask must be null.

XXX should throw a real exception for bogon parameters (vs. Error).

Parameter	Description
offset	The offset from the previous segment to start matching
length	The length of the bytes to match
sequence	The sequence of bytes to match
mask	If non-null, its a bit mask that indicates which bytes in `sequence' should be matched.

Overrides:

match in class pj_DemultiplexKey

   public void matchIPv4(int offset, 
                         int source, 
                         int dest, 
                         int protocol) 

Add a segment to match an IPv4 header. Offset is the expected offset of the IPv4 header in the packet.

Use this instead of the vanilla match() to get a "payloadOffset" in the deliver func that will skip IP options. (A vanilla match() call will leave payloadOffset in the first byte after the "protocol" byte, which is not necessairly the first byte of the payload in an IP packet (e.g., one with options).

XXX need well-defined wildcards for addresses and protocols.

Parameter	Description
offset	the offset of the IPv4 header in the packet.
source	the 32-bit IPv4 source address to match in the header.
dest	the 32-bit IPv4 destination address to match in the header.
protocol	the 16-bit IPv4 protocol identifier.

Overrides:

matchIPv4 in class pj_DemultiplexKey

   public void matchUDP(int offset, 
                        int srcPort, 
                        int destPort) 

Add a segment to match a UDP header, needs to be preceded by a call to matchIPv4.

XXX the exact semantics of 'offset' are not worked out yet.

Overrides:

matchUDP in class pj_DemultiplexKey

   public void matchTCP(int offset, 
                        int srcPort, 
                        int destPort) 

Add a segment to match a TCP header, needs to be preceded by a call to matchIPv4

XXX the exact semantics of 'offset' are not worked out yet.

Overrides:

matchTCP in class pj_DemultiplexKey

   public void matchANEP(int offset, 
                         byte version, 
                         boolean allVersions, 
                         short protocolID) 

Add a segment that matches an ANEP header

Parameter	Description
offset	The offset from the previous segment
version	The ANEP version number to match
allVersions	Match any version of ANEP
protocolID	The protocolID to match

Overrides:

matchANEP in class pj_DemultiplexKey

   public final int matches(byte[] payload, 
                            int payloadStart, 
                            int payloadLength) 

Test a packet to see if this key matches.

XXX payloadLength has odd semantics. Either explain why, or fix the callers of this method.

Parameter	Description
payload	The packet data
payloadStart	The place to start matching in `payload'
payloadLength	The length of data in payload, including bytes up to payloadStart.

Returns:

0 if there was an error otherwise the index of the first byte after the end of the key.

Overrides:

matches in class pj_DemultiplexKey

   pj_DemultiplexKey getNativeKey() 

   public String toString() 

Overrides:

toString in class pj_DemultiplexKey

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