Class: TFTP::Handler::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/tftp/tftp.rb

Overview

Base handler contains the common methods for real handlers.

Direct Known Subclasses

RWSimple

Instance Method Summary collapse

Constructor Details

#initialize(opts = {}) ⇒ Base

Initialize the handler.

Options:

  • :logger => logger object (e.g. a Logger instance)
  • :timeout => used while waiting for next DATA/ACK packets (default: 5s)

All given options are saved in @opts.

Parameters:

  • opts (Hash) (defaults to: {}) —

    Options



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# File 'lib/tftp/tftp.rb', line 109

def initialize(opts = {})
  @logger = opts[:logger]
  @timeout = opts[:timeout] || 5
  @opts = opts
end

Instance Method Details

#log(level, msg) ⇒ Object (private) 



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# File 'lib/tftp/tftp.rb', line 196

def log(level, msg)
  @logger.send(level, msg) if @logger
end

#recv(tag, sock, io) ⇒ Boolean

Receive data over an established connection.

Doesn't close neither sock nor io. Returns true if whole file has been received, false otherwise.

Parameters:

  • tag (String) —

    Tag used for logging

  • sock (UDPSocket) —

    Connected socket

  • io (IO) —

    Object to write data to

Returns:

  • (Boolean) 


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# File 'lib/tftp/tftp.rb', line 163

def recv(tag, sock, io)
  sock.send(Packet::ACK.new(0).encode, 0)
  seq = 1
  begin
    loop do
      unless IO.select([sock], nil, nil, @timeout)
        log :warn, "#{tag} Timeout at block ##{seq}"
        return false
      end
      msg, _ = sock.recvfrom(516, 0)
      pkt = Packet.parse(msg)
      if pkt.class != Packet::DATA
        log :warn, "#{tag} Expected DATA but got: #{pkt.class}"
        return false
      end
      if pkt.seq != seq
        log :warn, "#{tag} Seq mismatch: #{seq} != #{pkt.seq}"
        return false
      end
      io.write(pkt.data)
      sock.send(Packet::ACK.new(seq).encode, 0)
      break if pkt.last?
      seq = (seq + 1) & 0xFFFF
    end
  rescue ParseError => e
    log :warn, "#{tag} Packet parse error: #{e.to_s}"
    return false
  end
  log :info, "#{tag} Received file"
  true
end

#send(tag, sock, io) ⇒ Object

Send data over an established connection.

Doesn't close neither sock nor io.

Parameters:

  • tag (String) —

    Tag used for logging

  • sock (UDPSocket) —

    Connected socket

  • io (IO) —

    Object to send data from



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# File 'lib/tftp/tftp.rb', line 122

def send(tag, sock, io)
  seq = 1
  begin
    while not io.eof?
      block = io.read(512)
      sock.send(Packet::DATA.new(seq, block).encode, 0)
      unless IO.select([sock], nil, nil, @timeout)
        log :warn, "#{tag} Timeout at block ##{seq}"
        return
      end
      msg, _ = sock.recvfrom(4, 0)
      pkt = Packet.parse(msg)
      if pkt.class != Packet::ACK
        log :warn, "#{tag} Expected ACK but got: #{pkt.class}"
        return
      end
      if pkt.seq != seq
        log :warn, "#{tag} Seq mismatch: #{seq} != #{pkt.seq}"
        return
      end
      # Increment with wrap around at 16 bit boundary,
      # because of tftp block number field size limit.
      seq = (seq + 1) & 0xFFFF
    end
    sock.send(Packet::DATA.new(seq, '').encode, 0) if io.size % 512 == 0
  rescue ParseError => e
    log :warn, "#{tag} Packet parse error: #{e.to_s}"
    return
  end
  log :info, "#{tag} Sent file"
end