class TFTP::Handler::Base

Base handler contains the common methods for real handlers.

Public Class Methods

new(opts = {}) click to toggle source

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.

@param opts [Hash] Options

# File lib/tftp/tftp.rb, line 109
def initialize(opts = {})
  @logger = opts[:logger]
  @timeout = opts[:timeout] || 5
  @opts = opts
end

Public Instance Methods

recv(tag, sock, io) click to toggle source

Receive data over an established connection.

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

@param tag [String] Tag used for logging @param sock [UDPSocket] Connected socket @param io [IO] Object to write data to @return [Boolean]

# 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) click to toggle source

Send data over an established connection.

Doesn't close neither sock nor io.

@param tag [String] Tag used for logging @param sock [UDPSocket] Connected socket @param io [IO] Object to send data from

# 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

Private Instance Methods

log(level, msg) click to toggle source
# File lib/tftp/tftp.rb, line 196
def log(level, msg)
  @logger.send(level, msg) if @logger
end