Class: TFTP::Handler::RWSimple

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

Overview

Basic read-write session over a ‘physical’ directory.

Instance Method Summary collapse

Methods inherited from Base

#log, #recv, #send

Constructor Details

#initialize(path, opts = {}) ⇒ RWSimple

Initialize the handler.

Options:

  • :no_read => deny read access if true
  • :no_write => deny write access if true

Parameters:

  • path (String) —

    Path to serving root directory

  • opts (Hash) (defaults to: {}) —

    Options



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# File 'lib/tftp/tftp.rb', line 212

def initialize(path, opts = {})
  @path = path
  super(opts)
end

Instance Method Details

#run!(tag, req, sock, src) ⇒ Object

Handle a session.

Has to close the socket (and any other resources). Note that the current version ‘guards’ against path traversal by a simple substitution of ‘..’ with ‘‘.

Parameters:

  • tag (String) —

    Tag used for logging

  • req (Packet) —

    The initial request packet

  • sock (UDPSocket) —

    Connected socket

  • src (UDPSource) —

    Initial connection information



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# File 'lib/tftp/tftp.rb', line 227

def run!(tag, req, sock, src)
  name = req.filename.gsub('..', '__')
  path = File.join(@path, name)

  case req
  when Packet::RRQ
    if @opts[:no_read]
      log :info, "#{tag} Denied read request for #{req.filename}"
      sock.send(Packet::ERROR.new(2, 'Access denied.').encode, 0)
      sock.close
      return
    end
    log :info, "#{tag} Read request for #{req.filename} (#{req.mode})"
    unless File.exist? path
      log :warn, "#{tag} File not found"
      sock.send(Packet::ERROR.new(1, 'File not found.').encode, 0)
      sock.close
      return
    end
    mode = 'r'
    mode += 'b' if req.mode == :octet
    io = File.open(path, mode)
    send(tag, sock, io)
    sock.close
    io.close
  when Packet::WRQ
    if @opts[:no_write]
      log :info, "#{tag} Denied write request for #{req.filename}"
      sock.send(Packet::ERROR.new(2, 'Access denied.').encode, 0)
      sock.close
      return
    end
    log :info, "#{tag} Write request for #{req.filename} (#{req.mode})"
    mode = 'w'
    mode += 'b' if req.mode == :octet
    io = File.open(path, mode)
    ok = recv(tag, sock, io)
    sock.close
    io.close
    unless ok
      log :warn, "#{tag} Removing partial file #{req.filename}"
      File.delete(path)
    end
  end
end