/usr/lib/ruby/vendor_ruby/net/ssh/buffered_io.rb is in ruby-net-ssh 1:3.2.0-1.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 | require 'net/ssh/buffer'
require 'net/ssh/loggable'
require 'net/ssh/ruby_compat'
module Net; module SSH
# This module is used to extend sockets and other IO objects, to allow
# them to be buffered for both read and write. This abstraction makes it
# quite easy to write a select-based event loop
# (see Net::SSH::Connection::Session#listen_to).
#
# The general idea is that instead of calling #read directly on an IO that
# has been extended with this module, you call #fill (to add pending input
# to the internal read buffer), and then #read_available (to read from that
# buffer). Likewise, you don't call #write directly, you call #enqueue to
# add data to the write buffer, and then #send_pending or #wait_for_pending_sends
# to actually send the data across the wire.
#
# In this way you can easily use the object as an argument to IO.select,
# calling #fill when it is available for read, or #send_pending when it is
# available for write, and then call #enqueue and #read_available during
# the idle times.
#
# socket = TCPSocket.new(address, port)
# socket.extend(Net::SSH::BufferedIo)
#
# ssh.listen_to(socket)
#
# ssh.loop do
# if socket.available > 0
# puts socket.read_available
# socket.enqueue("response\n")
# end
# end
#
# Note that this module must be used to extend an instance, and should not
# be included in a class. If you do want to use it via an include, then you
# must make sure to invoke the private #initialize_buffered_io method in
# your class' #initialize method:
#
# class Foo < IO
# include Net::SSH::BufferedIo
#
# def initialize
# initialize_buffered_io
# # ...
# end
# end
module BufferedIo
include Loggable
# Called when the #extend is called on an object, with this module as the
# argument. It ensures that the modules instance variables are all properly
# initialized.
def self.extended(object) #:nodoc:
# need to use __send__ because #send is overridden in Socket
object.__send__(:initialize_buffered_io)
end
# Tries to read up to +n+ bytes of data from the remote end, and appends
# the data to the input buffer. It returns the number of bytes read, or 0
# if no data was available to be read.
def fill(n=8192)
input.consume!
data = recv(n)
debug { "read #{data.length} bytes" }
input.append(data)
return data.length
end
# Read up to +length+ bytes from the input buffer. If +length+ is nil,
# all available data is read from the buffer. (See #available.)
def read_available(length=nil)
input.read(length || available)
end
# Returns the number of bytes available to be read from the input buffer.
# (See #read_available.)
def available
input.available
end
# Enqueues data in the output buffer, to be written when #send_pending
# is called. Note that the data is _not_ sent immediately by this method!
def enqueue(data)
output.append(data)
end
# Returns +true+ if there is data waiting in the output buffer, and
# +false+ otherwise.
def pending_write?
output.length > 0
end
# Sends as much of the pending output as possible. Returns +true+ if any
# data was sent, and +false+ otherwise.
def send_pending
if output.length > 0
sent = send(output.to_s, 0)
debug { "sent #{sent} bytes" }
output.consume!(sent)
return sent > 0
else
return false
end
end
# Calls #send_pending repeatedly, if necessary, blocking until the output
# buffer is empty.
def wait_for_pending_sends
send_pending
while output.length > 0
result = Net::SSH::Compat.io_select(nil, [self]) or next
next unless result[1].any?
send_pending
end
end
public # these methods are primarily for use in tests
def write_buffer #:nodoc:
output.to_s
end
def read_buffer #:nodoc:
input.to_s
end
private
#--
# Can't use attr_reader here (after +private+) without incurring the
# wrath of "ruby -w". We hates it.
#++
def input; @input; end
def output; @output; end
# Initializes the intput and output buffers for this object. This method
# is called automatically when the module is mixed into an object via
# Object#extend (see Net::SSH::BufferedIo.extended), but must be called
# explicitly in the +initialize+ method of any class that uses
# Module#include to add this module.
def initialize_buffered_io
@input = Net::SSH::Buffer.new
@output = Net::SSH::Buffer.new
end
end
# Fixes for two issues by Miklós Fazekas:
#
# * if client closes a forwarded connection, but the server is
# reading, net-ssh terminates with IOError socket closed.
# * if client force closes (RST) a forwarded connection, but
# server is reading, net-ssh terminates with [an exception]
#
# See:
#
# http://net-ssh.lighthouseapp.com/projects/36253/tickets/7
# http://github.com/net-ssh/net-ssh/tree/portfwfix
#
module ForwardedBufferedIo
def fill(n=8192)
begin
super(n)
rescue Errno::ECONNRESET => e
debug { "connection was reset => shallowing exception:#{e}" }
return 0
rescue IOError => e
if e.message =~ /closed/ then
debug { "connection was reset => shallowing exception:#{e}" }
return 0
else
raise
end
end
end
def send_pending
begin
super
rescue Errno::ECONNRESET => e
debug { "connection was reset => shallowing exception:#{e}" }
return 0
rescue IOError => e
if e.message =~ /closed/ then
debug { "connection was reset => shallowing exception:#{e}" }
return 0
else
raise
end
end
end
end
end; end
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