# = net/telnet.rb - Simple Telnet Client Library
#
# Author:: Wakou Aoyama <wakou@ruby-lang.org>
# Documentation:: William Webber and Wakou Aoyama
#
# This file holds the class Net::Telnet, which provides client-side
# telnet functionality.
#
# For documentation, see Net::Telnet.
#
require "socket"
require "timeout"
require "English"
module Net
#
# == Net::Telnet
#
# Provides telnet client functionality.
#
# This class also has, through delegation, all the methods of a
# socket object (by default, a +TCPSocket+, but can be set by the
# +Proxy+ option to <tt>new()</tt>). This provides methods such as
# <tt>close()</tt> to end the session and <tt>sysread()</tt> to read
# data directly from the host, instead of via the <tt>waitfor()</tt>
# mechanism. Note that if you do use <tt>sysread()</tt> directly
# when in telnet mode, you should probably pass the output through
# <tt>preprocess()</tt> to extract telnet command sequences.
#
# == Overview
#
# The telnet protocol allows a client to login remotely to a user
# account on a server and execute commands via a shell. The equivalent
# is done by creating a Net::Telnet class with the +Host+ option
# set to your host, calling #login() with your user and password,
# issuing one or more #cmd() calls, and then calling #close()
# to end the session. The #waitfor(), #print(), #puts(), and
# #write() methods, which #cmd() is implemented on top of, are
# only needed if you are doing something more complicated.
#
# A Net::Telnet object can also be used to connect to non-telnet
# services, such as SMTP or HTTP. In this case, you normally
# want to provide the +Port+ option to specify the port to
# connect to, and set the +Telnetmode+ option to false to prevent
# the client from attempting to interpret telnet command sequences.
# Generally, #login() will not work with other protocols, and you
# have to handle authentication yourself.
#
# For some protocols, it will be possible to specify the +Prompt+
# option once when you create the Telnet object and use #cmd() calls;
# for others, you will have to specify the response sequence to
# look for as the Match option to every #cmd() call, or call
# #puts() and #waitfor() directly; for yet others, you will have
# to use #sysread() instead of #waitfor() and parse server
# responses yourself.
#
# It is worth noting that when you create a new Net::Telnet object,
# you can supply a proxy IO channel via the Proxy option. This
# can be used to attach the Telnet object to other Telnet objects,
# to already open sockets, or to any read-write IO object. This
# can be useful, for instance, for setting up a test fixture for
# unit testing.
#
# == Examples
#
# === Log in and send a command, echoing all output to stdout
#
# localhost = Net::Telnet::new("Host" => "localhost",
# "Timeout" => 10,
# "Prompt" => /[$%#>] \z/n)
# localhost.login("username", "password") { |c| print c }
# localhost.cmd("command") { |c| print c }
# localhost.close
#
#
# === Check a POP server to see if you have mail
#
# pop = Net::Telnet::new("Host" => "your_destination_host_here",
# "Port" => 110,
# "Telnetmode" => false,
# "Prompt" => /^\+OK/n)
# pop.cmd("user " + "your_username_here") { |c| print c }
# pop.cmd("pass " + "your_password_here") { |c| print c }
# pop.cmd("list") { |c| print c }
#
# == References
#
# There are a large number of RFCs relevant to the Telnet protocol.
# RFCs 854-861 define the base protocol. For a complete listing
# of relevant RFCs, see
# http://www.omnifarious.org/~hopper/technical/telnet-rfc.html
#
class Telnet
# :stopdoc:
IAC = 255.chr # "\377" # "\xff" # interpret as command
DONT = 254.chr # "\376" # "\xfe" # you are not to use option
DO = 253.chr # "\375" # "\xfd" # please, you use option
WONT = 252.chr # "\374" # "\xfc" # I won't use option
WILL = 251.chr # "\373" # "\xfb" # I will use option
SB = 250.chr # "\372" # "\xfa" # interpret as subnegotiation
GA = 249.chr # "\371" # "\xf9" # you may reverse the line
EL = 248.chr # "\370" # "\xf8" # erase the current line
EC = 247.chr # "\367" # "\xf7" # erase the current character
AYT = 246.chr # "\366" # "\xf6" # are you there
AO = 245.chr # "\365" # "\xf5" # abort output--but let prog finish
IP = 244.chr # "\364" # "\xf4" # interrupt process--permanently
BREAK = 243.chr # "\363" # "\xf3" # break
DM = 242.chr # "\362" # "\xf2" # data mark--for connect. cleaning
NOP = 241.chr # "\361" # "\xf1" # nop
SE = 240.chr # "\360" # "\xf0" # end sub negotiation
EOR = 239.chr # "\357" # "\xef" # end of record (transparent mode)
ABORT = 238.chr # "\356" # "\xee" # Abort process
SUSP = 237.chr # "\355" # "\xed" # Suspend process
EOF = 236.chr # "\354" # "\xec" # End of file
SYNCH = 242.chr # "\362" # "\xf2" # for telfunc calls
OPT_BINARY = 0.chr # "\000" # "\x00" # Binary Transmission
OPT_ECHO = 1.chr # "\001" # "\x01" # Echo
OPT_RCP = 2.chr # "\002" # "\x02" # Reconnection
OPT_SGA = 3.chr # "\003" # "\x03" # Suppress Go Ahead
OPT_NAMS = 4.chr # "\004" # "\x04" # Approx Message Size Negotiation
OPT_STATUS = 5.chr # "\005" # "\x05" # Status
OPT_TM = 6.chr # "\006" # "\x06" # Timing Mark
OPT_RCTE = 7.chr # "\a" # "\x07" # Remote Controlled Trans and Echo
OPT_NAOL = 8.chr # "\010" # "\x08" # Output Line Width
OPT_NAOP = 9.chr # "\t" # "\x09" # Output Page Size
OPT_NAOCRD = 10.chr # "\n" # "\x0a" # Output Carriage-Return Disposition
OPT_NAOHTS = 11.chr # "\v" # "\x0b" # Output Horizontal Tab Stops
OPT_NAOHTD = 12.chr # "\f" # "\x0c" # Output Horizontal Tab Disposition
OPT_NAOFFD = 13.chr # "\r" # "\x0d" # Output Formfeed Disposition
OPT_NAOVTS = 14.chr # "\016" # "\x0e" # Output Vertical Tabstops
OPT_NAOVTD = 15.chr # "\017" # "\x0f" # Output Vertical Tab Disposition
OPT_NAOLFD = 16.chr # "\020" # "\x10" # Output Linefeed Disposition
OPT_XASCII = 17.chr # "\021" # "\x11" # Extended ASCII
OPT_LOGOUT = 18.chr # "\022" # "\x12" # Logout
OPT_BM = 19.chr # "\023" # "\x13" # Byte Macro
OPT_DET = 20.chr # "\024" # "\x14" # Data Entry Terminal
OPT_SUPDUP = 21.chr # "\025" # "\x15" # SUPDUP
OPT_SUPDUPOUTPUT = 22.chr # "\026" # "\x16" # SUPDUP Output
OPT_SNDLOC = 23.chr # "\027" # "\x17" # Send Location
OPT_TTYPE = 24.chr # "\030" # "\x18" # Terminal Type
OPT_EOR = 25.chr # "\031" # "\x19" # End of Record
OPT_TUID = 26.chr # "\032" # "\x1a" # TACACS User Identification
OPT_OUTMRK = 27.chr # "\e" # "\x1b" # Output Marking
OPT_TTYLOC = 28.chr # "\034" # "\x1c" # Terminal Location Number
OPT_3270REGIME = 29.chr # "\035" # "\x1d" # Telnet 3270 Regime
OPT_X3PAD = 30.chr # "\036" # "\x1e" # X.3 PAD
OPT_NAWS = 31.chr # "\037" # "\x1f" # Negotiate About Window Size
OPT_TSPEED = 32.chr # " " # "\x20" # Terminal Speed
OPT_LFLOW = 33.chr # "!" # "\x21" # Remote Flow Control
OPT_LINEMODE = 34.chr # "\"" # "\x22" # Linemode
OPT_XDISPLOC = 35.chr # "#" # "\x23" # X Display Location
OPT_OLD_ENVIRON = 36.chr # "$" # "\x24" # Environment Option
OPT_AUTHENTICATION = 37.chr # "%" # "\x25" # Authentication Option
OPT_ENCRYPT = 38.chr # "&" # "\x26" # Encryption Option
OPT_NEW_ENVIRON = 39.chr # "'" # "\x27" # New Environment Option
OPT_EXOPL = 255.chr # "\377" # "\xff" # Extended-Options-List
NULL = "\000"
CR = "\015"
LF = "\012"
EOL = CR + LF
REVISION = '$Id$'
# :startdoc:
#
# Creates a new Net::Telnet object.
#
# Attempts to connect to the host (unless the Proxy option is
# provided: see below). If a block is provided, it is yielded
# status messages on the attempt to connect to the server, of
# the form:
#
# Trying localhost...
# Connected to localhost.
#
# +options+ is a hash of options. The following example lists
# all options and their default values.
#
# host = Net::Telnet::new(
# "Host" => "localhost", # default: "localhost"
# "Port" => 23, # default: 23
# "Binmode" => false, # default: false
# "Output_log" => "output_log", # default: nil (no output)
# "Dump_log" => "dump_log", # default: nil (no output)
# "Prompt" => /[$%#>] \z/n, # default: /[$%#>] \z/n
# "Telnetmode" => true, # default: true
# "Timeout" => 10, # default: 10
# # if ignore timeout then set "Timeout" to false.
# "Waittime" => 0, # default: 0
# "Proxy" => proxy # default: nil
# # proxy is Net::Telnet or IO object
# )
#
# The options have the following meanings:
#
# Host:: the hostname or IP address of the host to connect to, as a String.
# Defaults to "localhost".
#
# Port:: the port to connect to. Defaults to 23.
#
# Binmode:: if false (the default), newline substitution is performed.
# Outgoing LF is
# converted to CRLF, and incoming CRLF is converted to LF. If
# true, this substitution is not performed. This value can
# also be set with the #binmode() method. The
# outgoing conversion only applies to the #puts() and #print()
# methods, not the #write() method. The precise nature of
# the newline conversion is also affected by the telnet options
# SGA and BIN.
#
# Output_log:: the name of the file to write connection status messages
# and all received traffic to. In the case of a proper
# Telnet session, this will include the client input as
# echoed by the host; otherwise, it only includes server
# responses. Output is appended verbatim to this file.
# By default, no output log is kept.
#
# Dump_log:: as for Output_log, except that output is written in hexdump
# format (16 bytes per line as hex pairs, followed by their
# printable equivalent), with connection status messages
# preceded by '#', sent traffic preceded by '>', and
# received traffic preceded by '<'. By default, not dump log
# is kept.
#
# Prompt:: a regular expression matching the host's command-line prompt
# sequence. This is needed by the Telnet class to determine
# when the output from a command has finished and the host is
# ready to receive a new command. By default, this regular
# expression is /[$%#>] \z/n.
#
# Telnetmode:: a boolean value, true by default. In telnet mode,
# traffic received from the host is parsed for special
# command sequences, and these sequences are escaped
# in outgoing traffic sent using #puts() or #print()
# (but not #write()). If you are using the Net::Telnet
# object to connect to a non-telnet service (such as
# SMTP or POP), this should be set to "false" to prevent
# undesired data corruption. This value can also be set
# by the #telnetmode() method.
#
# Timeout:: the number of seconds to wait before timing out both the
# initial attempt to connect to host (in this constructor),
# and all attempts to read data from the host (in #waitfor(),
# #cmd(), and #login()). Exceeding this timeout causes a
# TimeoutError to be raised. The default value is 10 seconds.
# You can disable the timeout by setting this value to false.
# In this case, the connect attempt will eventually timeout
# on the underlying connect(2) socket call with an
# Errno::ETIMEDOUT error (but generally only after a few
# minutes), but other attempts to read data from the host
# will hand indefinitely if no data is forthcoming.
#
# Waittime:: the amount of time to wait after seeing what looks like a
# prompt (that is, received data that matches the Prompt
# option regular expression) to see if more data arrives.
# If more data does arrive in this time, Net::Telnet assumes
# that what it saw was not really a prompt. This is to try to
# avoid false matches, but it can also lead to missing real
# prompts (if, for instance, a background process writes to
# the terminal soon after the prompt is displayed). By
# default, set to 0, meaning not to wait for more data.
#
# Proxy:: a proxy object to used instead of opening a direct connection
# to the host. Must be either another Net::Telnet object or
# an IO object. If it is another Net::Telnet object, this
# instance will use that one's socket for communication. If an
# IO object, it is used directly for communication. Any other
# kind of object will cause an error to be raised.
#
def initialize(options) # :yield: mesg
@options = options
@options["Host"] = "localhost" unless @options.has_key?("Host")
@options["Port"] = 23 unless @options.has_key?("Port")
@options["Prompt"] = /[$%#>] \z/n unless @options.has_key?("Prompt")
@options["Timeout"] = 10 unless @options.has_key?("Timeout")
@options["Waittime"] = 0 unless @options.has_key?("Waittime")
unless @options.has_key?("Binmode")
@options["Binmode"] = false
else
unless (true == @options["Binmode"] or false == @options["Binmode"])
raise ArgumentError, "Binmode option must be true or false"
end
end
unless @options.has_key?("Telnetmode")
@options["Telnetmode"] = true
else
unless (true == @options["Telnetmode"] or false == @options["Telnetmode"])
raise ArgumentError, "Telnetmode option must be true or false"
end
end
@telnet_option = { "SGA" => false, "BINARY" => false }
if @options.has_key?("Output_log")
@log = File.open(@options["Output_log"], 'a+')
@log.sync = true
@log.binmode
end
if @options.has_key?("Dump_log")
@dumplog = File.open(@options["Dump_log"], 'a+')
@dumplog.sync = true
@dumplog.binmode
def @dumplog.log_dump(dir, x) # :nodoc:
len = x.length
addr = 0
offset = 0
while 0 < len
if len < 16
line = x[offset, len]
else
line = x[offset, 16]
end
hexvals = line.unpack('H*')[0]
hexvals += ' ' * (32 - hexvals.length)
hexvals = format("%s %s %s %s " * 4, *hexvals.unpack('a2' * 16))
line = line.gsub(/[\000-\037\177-\377]/n, '.')
printf "%s 0x%5.5x: %s%s\n", dir, addr, hexvals, line
addr += 16
offset += 16
len -= 16
end
print "\n"
end
end
if @options.has_key?("Proxy")
if @options["Proxy"].kind_of?(Net::Telnet)
@sock = @options["Proxy"].sock
elsif @options["Proxy"].kind_of?(IO)
@sock = @options["Proxy"]
else
raise "Error: Proxy must be an instance of Net::Telnet or IO."
end
else
message = "Trying " + @options["Host"] + "...\n"
yield(message) if block_given?
@log.write(message) if @options.has_key?("Output_log")
@dumplog.log_dump('#', message) if @options.has_key?("Dump_log")
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