mirror of
https://github.com/bobbimanners/emailler.git
synced 2024-11-18 21:07:03 +00:00
233 lines
9.1 KiB
Ruby
233 lines
9.1 KiB
Ruby
#
|
|
# minimal TFTP server implementation for use with netboot65
|
|
#
|
|
# supports RRQ, WRQ
|
|
# a RRQ for a filename starting with $ is treated as a directory request
|
|
# Jonno Downes (jonno@jamtronix.com) - January, 2009
|
|
#
|
|
# TFTP spec : http://www.ietf.org/rfc/rfc1350.txt
|
|
|
|
require 'socket'
|
|
class Netboot65TFTPServer
|
|
|
|
|
|
|
|
TFTP_OPCODES={
|
|
1=>'RRQ', #read request
|
|
2=>'WRQ', #write request
|
|
3=>'DATA',
|
|
4=>'ACK',
|
|
5=>'ERROR',
|
|
}
|
|
|
|
TFTP_ERRORCODES={
|
|
1 =>'File not found.',
|
|
2 =>'Access violation.',
|
|
3 =>'Disk full or allocation exceeded.',
|
|
4 =>'Illegal TFTP operation.',
|
|
5 =>'Unknown transfer ID.',
|
|
6 =>'File already exists.',
|
|
7 =>'No such user.',
|
|
}
|
|
TFTP_MAX_RESENDS=10
|
|
|
|
attr_reader :bootfile_dir,:port,:server_thread
|
|
def initialize(bootfile_dir,port=69)
|
|
@bootfile_dir=bootfile_dir
|
|
@port=port
|
|
@server_thread=nil
|
|
@current_connection={}
|
|
end
|
|
|
|
def send_error(client_ip,client_port,error_code,error_msg)
|
|
packet=[5,error_code,error_msg,0].pack("nnA#{error_msg.length}c")
|
|
socket=UDPSocket.open.send(packet,0,client_ip,client_port)
|
|
log_msg("sent error #{error_code}:'#{error_msg}' to #{client_ip}:#{client_port}")
|
|
end
|
|
|
|
def send_data(client_ip,client_port,filename,data_to_send)
|
|
|
|
client_sock=UDPSocket.open
|
|
client_sock.connect(client_ip,client_port)
|
|
|
|
blocks_to_send=1+(data_to_send.length.to_f/512.0).floor
|
|
log_msg("sending #{filename} to #{client_ip}:#{client_port} (#{blocks_to_send} blocks)")
|
|
blocks_to_send.times do |block_number|
|
|
block_data=data_to_send[block_number*512,512]
|
|
packet=[3,block_number+1,block_data].pack("nnA*")
|
|
got_ack=false
|
|
TFTP_MAX_RESENDS.times do |attempt_number|
|
|
log_msg("sending block #{block_number+1}/#{blocks_to_send} of #{filename} to #{client_ip}:#{client_port} - #{block_data.length} bytes - attempt #{attempt_number+1}")
|
|
client_sock.send(packet,0,client_ip,client_port)
|
|
if (IO.select([client_sock], nil, nil, 1)) then
|
|
data,addr_info=client_sock.recvfrom(4096)
|
|
client_ip=addr_info[3]
|
|
client_port=addr_info[1]
|
|
opcode=data[0,2].unpack("n")[0]
|
|
opcode_description=TFTP_OPCODES[opcode]
|
|
if opcode==4 then
|
|
acked_block_number=data[2,2].unpack("n")[0]
|
|
log_msg "TFTP: ACK from #{client_ip}:#{client_port} - block #{acked_block_number}"
|
|
got_ack=true if acked_block_number==block_number+1
|
|
else
|
|
opcode_description="[UNK]" if opcode_description.nil?
|
|
log_msg "TFTP: response from #{client_ip}:#{client_port} - opcode #{opcode} : #{opcode_description}"
|
|
end
|
|
end
|
|
break if got_ack
|
|
end
|
|
if !got_ack then
|
|
log_msg "TFTP: timed out waiting for ACK of block #{block_number} from #{client_ip}"
|
|
break
|
|
end
|
|
end
|
|
end
|
|
|
|
|
|
def recv_data(client_ip,client_port,filename,file_handle)
|
|
|
|
client_sock=UDPSocket.open
|
|
client_sock.connect(client_ip,client_port)
|
|
client_id="#{client_ip}:#{client_port}"
|
|
if @current_connection[client_id]==true then
|
|
log_msg("already sending to #{client_id}" )
|
|
end
|
|
@current_connection[client_id]=true
|
|
log_msg("receiving #{filename} from #{client_ip}:#{client_port}")
|
|
got_last_block=false
|
|
finished=false
|
|
block_number=0
|
|
finished
|
|
until finished do
|
|
packet=[4,block_number].pack("nn")
|
|
got_block=false
|
|
TFTP_MAX_RESENDS.times do |attempt_number|
|
|
log_msg("ACKing block #{block_number} of #{filename} from #{client_ip}:#{client_port} - attempt #{attempt_number+1}")
|
|
client_sock.send(packet,0,client_ip,client_port)
|
|
if got_last_block then
|
|
puts "last block received"
|
|
finished=true
|
|
break
|
|
else
|
|
if (IO.select([client_sock], nil, nil, 1)) then
|
|
data,addr_info=client_sock.recvfrom(4096)
|
|
client_ip=addr_info[3]
|
|
client_port=addr_info[1]
|
|
opcode=data[0,2].unpack("n")[0]
|
|
opcode_description=TFTP_OPCODES[opcode]
|
|
if opcode==3 then
|
|
recved_block_number=data[2,2].unpack("n")[0]
|
|
block_data=data[4,512]
|
|
got_last_block=(block_data.length!=512)
|
|
log_msg "TFTP: DATA from #{client_ip}:#{client_port} - block #{recved_block_number} - #{block_data.length} bytes"
|
|
if recved_block_number==block_number+1
|
|
got_block=true
|
|
file_handle<<block_data
|
|
end
|
|
else
|
|
opcode_description="[UNK]" if opcode_description.nil?
|
|
log_msg "TFTP: response from #{client_ip}:#{client_port} - opcode #{opcode} : #{opcode_description}"
|
|
end
|
|
end
|
|
break if got_block
|
|
end
|
|
end
|
|
if !got_block && !finished then
|
|
log_msg "TFTP: timed out waiting for DATA for block #{block_number+1} from #{client_ip}"
|
|
finished=true
|
|
break
|
|
end
|
|
block_number+=1
|
|
end
|
|
file_handle.close
|
|
@current_connection[client_id]=false
|
|
end
|
|
|
|
def start()
|
|
log_msg "TFTP: serving #{bootfile_dir} on port #{port}"
|
|
Socket.do_not_reverse_lookup = true
|
|
@server_thread=Thread.start do
|
|
|
|
loop do
|
|
socket=UDPSocket.open
|
|
socket.setsockopt Socket::SOL_SOCKET, Socket::SO_REUSEADDR, 1
|
|
log_msg "waiting for TFTP client to connect"
|
|
socket.bind("",port)
|
|
data,addr_info=socket.recvfrom(4096)
|
|
client_ip=addr_info[3]
|
|
client_port=addr_info[1]
|
|
opcode=data[0,2].unpack("n")[0]
|
|
opcode_description=TFTP_OPCODES[opcode]
|
|
opcode_description="[UNK]" if opcode_description.nil?
|
|
log_msg "TFTP: connect from #{client_ip}:#{client_port} - opcode #{opcode} : #{opcode_description}"
|
|
case opcode
|
|
when 1 : #READ REQUEST
|
|
opcode,filename_and_mode=data.unpack("nA*")
|
|
filename,mode=filename_and_mode.split(0.chr)
|
|
log_msg "RRQ for #{filename} (#{mode})"
|
|
if filename=~/^\./ || filename=~/\.\./ then #looks like something dodgy - either a dotfile or a directory traversal attempt
|
|
send_error(client_ip,client_port,1,"'#{filename}' invalid filename")
|
|
elsif filename=~/^\$(.*)/ then #it's a directory request
|
|
filemask="/#{$1}"
|
|
filemask="#{filemask}/*.*" unless filemask=~/\*/
|
|
log_msg "DIR for #{filemask}"
|
|
data_to_send=""
|
|
Dir.glob("#{bootfile_dir}#{filemask}").each do |full_filename|
|
|
filename=full_filename.sub(/^#{bootfile_dir}\/*/,'')
|
|
data_to_send<<"#{filename}\000"
|
|
end
|
|
data_to_send<<0.chr
|
|
Thread.new {send_data(client_ip,client_port,"DIR of #{filemask}",data_to_send)}
|
|
else
|
|
full_filename="#{bootfile_dir}/#{filename}"
|
|
if File.file?(full_filename) then
|
|
data_to_send=File.open(full_filename,"rb").read
|
|
Thread.new {send_data(client_ip,client_port,full_filename,data_to_send)}
|
|
else
|
|
send_error(client_ip,client_port,1,"'#{filename}' not found")
|
|
end
|
|
end
|
|
when 2 : #WRITE REQUEST
|
|
opcode,filename_and_mode=data.unpack("nA*")
|
|
filename,mode=filename_and_mode.split(0.chr)
|
|
log_msg "WRQ for #{filename} (#{mode})"
|
|
if filename=~/^\./ || filename=~/\.\./ then #looks like something dodgy - either a dotfile or a directory traversal attempt
|
|
send_error(client_ip,client_port,1,"'#{filename}' invalid filename")
|
|
else
|
|
full_filename="#{bootfile_dir}/#{filename}"
|
|
begin
|
|
file_handle=File.open(full_filename,"wb")
|
|
Thread.new {recv_data(client_ip,client_port,full_filename,file_handle)}
|
|
rescue Exception=>e
|
|
send_error(client_ip,client_port,2,"error writing to '#{filename}':#{e.to_s}")
|
|
end
|
|
end
|
|
when 0x65 : #DIR REQUEST
|
|
opcode,filemask_and_mode=data.unpack("nA*")
|
|
filemask,mode=filemask_and_mode.split(0.chr)
|
|
log_msg "DIR for #{filemask} (#{mode})"
|
|
if filename=~/^\./ || filename=~/\.\./ then #looks like something dodgy - either a dotfile or a directory traversal attempt
|
|
send_error(client_ip,client_port,1,"'#{filemask}' invalid filename")
|
|
else
|
|
data_to_send=""
|
|
Dir.chdir(bootfile_dir) do
|
|
Dir.glob(filemask).each {|filename| data_to_send<<"#{filename}\000"}
|
|
end
|
|
data_to_send<<0.chr
|
|
Thread.new {send_data(client_ip,client_port,"DIR of #{filemask}",data_to_send)}
|
|
end
|
|
else
|
|
send_error(client_ip,client_port,4,"opcode #{opcode} not supported")
|
|
end
|
|
socket.close
|
|
end
|
|
end
|
|
# @server_thread.join
|
|
end
|
|
|
|
def shutdown()
|
|
log_msg "TFTP: stopping"
|
|
server_thread.kill
|
|
end
|
|
|
|
end |