Class: Mu::Pcap::SCTP::Chunk::Init

Inherits:
Mu::Pcap::SCTP::Chunk show all
Defined in:
lib/mu/pcap/sctp/chunk/init.rb

Direct Known Subclasses

InitAck

Constant Summary

Constants inherited from Packet

Packet::IGNORE_UDP_PORTS

Instance Attribute Summary collapse

Attributes inherited from Mu::Pcap::SCTP::Chunk

#flags, #size, #type

Attributes inherited from Packet

#payload, #payload_raw

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Mu::Pcap::SCTP::Chunk

dummy_chunk, #padded_size

Methods inherited from Packet

#==, #deepdup, #flow_id, isolate_l7, normalize, #payload_bytes, #to_bytes

Constructor Details

#initialize ⇒ Init

Returns a new instance of Init.



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# File 'lib/mu/pcap/sctp/chunk/init.rb', line 13

def initialize
    super
    
    @type        = CHUNK_INIT
    @init_tag    = 0
    @a_rwnd      = 0
    @o_streams   = 0
    @i_streams   = 0
    @init_tsn    = 0
    @payload     = []
end

Instance Attribute Details

#a_rwnd ⇒ Object

Returns the value of attribute a_rwnd.



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# File 'lib/mu/pcap/sctp/chunk/init.rb', line 11

def a_rwnd
  @a_rwnd
end

#i_streams ⇒ Object

Returns the value of attribute i_streams.



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# File 'lib/mu/pcap/sctp/chunk/init.rb', line 11

def i_streams
  @i_streams
end

#init_tag ⇒ Object

Returns the value of attribute init_tag.



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# File 'lib/mu/pcap/sctp/chunk/init.rb', line 11

def init_tag
  @init_tag
end

#init_tsn ⇒ Object

Returns the value of attribute init_tsn.



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# File 'lib/mu/pcap/sctp/chunk/init.rb', line 11

def init_tsn
  @init_tsn
end

#o_streams ⇒ Object

Returns the value of attribute o_streams.



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# File 'lib/mu/pcap/sctp/chunk/init.rb', line 11

def o_streams
  @o_streams
end

Class Method Details

.from_bytes(flags, size, bytes) ⇒ Object 



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# File 'lib/mu/pcap/sctp/chunk/init.rb', line 25

def self.from_bytes flags, size, bytes
    # Basic validation
    Pcap.assert(bytes.length >= 16,
                "Truncated init chunk header: 16 > #{bytes.length}")
    
    # Read init chunk header
    init_tag, a_rwnd, o_streams, i_streams, init_tsn = bytes.unpack('NNnnN')
    
    # Create init chunk
    init           = Init.new
    init.flags     = flags
    init.size      = size
    init.init_tag  = init_tag
    init.a_rwnd    = a_rwnd
    init.o_streams = o_streams
    init.i_streams = i_streams
    init.init_tsn  = init_tsn
    
    # Initialize the counter
    length = 16
    
    # Collect the chunks
    while length < bytes.length
        # Parse new parameter from the bytes
        parameter = Parameter.from_bytes(bytes[length..-1])
        
        # Get parameter size with padding
        length += parameter.padded_size
        
        # Add chunk to the list
        init << parameter
    end
    
    # Return the result
    return init
end

Instance Method Details

#<<(parameter) ⇒ Object 



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# File 'lib/mu/pcap/sctp/chunk/init.rb', line 80

def << parameter
    @payload << parameter
end

#to_s ⇒ Object 



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# File 'lib/mu/pcap/sctp/chunk/init.rb', line 84

def to_s
    return "init(%d, %d, %d, %d, %d, %d, %s)" % [@size,
                                                 @init_tag,
                                                 @a_rwnd,
                                                 @o_streams,
                                                 @i_streams,
                                                 @init_tsn,
                                                 @payload.join(", ")]
end

#write(io, ip) ⇒ Object 



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# File 'lib/mu/pcap/sctp/chunk/init.rb', line 62

def write io, ip
    chunk_header = [@type, @flags, @size].pack('CCn')
    init_header  = [@init_tag,
                    @a_rwnd,
                    @o_streams,
                    @i_streams,
                    @init_tsn].pack('NNnnN')
    
    # Write Chunk header followed by the Init chunk header
    io.write(chunk_header)
    io.write(init_header)
    
    # Write each parameter
    @payload.each do |parameter|
        parameter.write(io, ip)
    end
end