module EventMachine
class FileNotFoundException < Exception # :nodoc:
end
# EventMachine::Connection is a class that is instantiated
# by EventMachine's processing loop whenever a new connection
# is created. (New connections can be either initiated locally
# to a remote server or accepted locally from a remote client.)
# When a Connection object is instantiated, it mixes in
# the functionality contained in the user-defined module
# specified in calls to EventMachine#connect or EventMachine#start_server.
# User-defined handler modules may redefine any or all of the standard
# methods defined here, as well as add arbitrary additional code
# that will also be mixed in.
#
# EventMachine manages one object inherited from EventMachine::Connection
# (and containing the mixed-in user code) for every network connection
# that is active at any given time.
# The event loop will automatically call methods on EventMachine::Connection
# objects whenever specific events occur on the corresponding connections,
# as described below.
#
# This class is never instantiated by user code, and does not publish an
# initialize method. The instance methods of EventMachine::Connection
# which may be called by the event loop are: post_init, receive_data,
# and unbind. All of the other instance methods defined here are called
# only by user code.
#
class Connection
attr_accessor :signature # :nodoc:
# Override .new so subclasses don't have to call super and can ignore
# connection-specific arguments
#
def self.new(sig, *args) #:nodoc:
allocate.instance_eval do
# Store signature
@signature = sig
associate_callback_target sig
# Call a superclass's #initialize if it has one
initialize(*args)
# post initialize callback
post_init
self
end
end
# Stubbed initialize so legacy superclasses can safely call super
#
def initialize(*args) #:nodoc:
end
def associate_callback_target(sig) #:nodoc:
# no-op for the time being, to match similar no-op in rubymain.cpp
end
# EventMachine::Connection#post_init is called by the event loop
# immediately after the network connection has been established,
# and before resumption of the network loop.
# This method is generally not called by user code, but is called automatically
# by the event loop. The base-class implementation is a no-op.
# This is a very good place to initialize instance variables that will
# be used throughout the lifetime of the network connection.
#
def post_init
end
# EventMachine::Connection#receive_data is called by the event loop
# whenever data has been received by the network connection.
# It is never called by user code.
# receive_data is called with a single parameter, a String containing
# the network protocol data, which may of course be binary. You will
# generally redefine this method to perform your own processing of the incoming data.
#
# Here's a key point which is essential to understanding the event-driven
# programming model: EventMachine knows absolutely nothing about the protocol
# which your code implements. You must not make any assumptions about
# the size of the incoming data packets, or about their alignment on any
# particular intra-message or PDU boundaries (such as line breaks).
# receive_data can and will send you arbitrary chunks of data, with the
# only guarantee being that the data is presented to your code in the order
# it was collected from the network. Don't even assume that the chunks of
# data will correspond to network packets, as EventMachine can and will coalesce
# several incoming packets into one, to improve performance. The implication for your
# code is that you generally will need to implement some kind of a state machine
# in your redefined implementation of receive_data. For a better understanding
# of this, read through the examples of specific protocol handlers in EventMachine::Protocols
#
# The base-class implementation of receive_data (which will be invoked if
# you don't redefine it) simply prints the size of each incoming data packet
# to stdout.
#
def receive_data data
puts "............>>>#{data.length}"
end
# #ssl_handshake_completed is called by EventMachine when the SSL/TLS handshake has
# been completed, as a result of calling #start_tls to initiate SSL/TLS on the connection.
#
# This callback exists because #post_init and #connection_completed are not reliable
# for indicating when an SSL/TLS connection is ready to have it's certificate queried for.
#
# See #get_peer_cert for application and example.
def ssl_handshake_completed
end
# #ssl_verify_peer is called by EventMachine when :verify_peer => true has been passed to #start_tls.
# It will be called with each certificate in the certificate chain provided by the remote peer.
# The cert will be passed as a String in PEM format, the same as in #get_peer_cert. It is up to user defined
# code to perform a check on the certificates. The return value from this callback is used to accept or deny the peer.
# A return value that is not nil or false triggers acceptance. If the peer is not accepted, the connection
# will be subsequently closed. See 'tests/test_ssl_verify.rb' for a simple example.
def ssl_verify_peer(cert)
end
# EventMachine::Connection#unbind is called by the framework whenever a connection
# (either a server or client connection) is closed. The close can occur because
# your code intentionally closes it (see close_connection and close_connection_after_writing),
# because the remote peer closed the connection, or because of a network error.
# You may not assume that the network connection is still open and able to send or
# receive data when the callback to unbind is made. This is intended only to give
# you a chance to clean up associations your code may have made to the connection
# object while it was open.
#
def unbind
end
# EventMachine::Connection#proxy_target_unbound is called by the reactor after attempting
# to relay incoming data to a descriptor (set as a proxy target descriptor with
# EventMachine::enable_proxy) that has already been closed.
def proxy_target_unbound
end
# EventMachine::Connection#proxy_incoming_to is called only by user code. It sets up
# a low-level proxy relay for all data inbound for this connection, to the connection given
# as the argument. This is essentially just a helper method for enable_proxy.
# See EventMachine::enable_proxy documentation for details.
def proxy_incoming_to(conn)
EventMachine::enable_proxy(self, conn)
end
# Helper method for EventMachine::disable_proxy(self)
def stop_proxying
EventMachine::disable_proxy(self)
end
# EventMachine::Connection#close_connection is called only by user code, and never
# by the event loop. You may call this method against a connection object in any
# callback handler, whether or not the callback was made against the connection
# you want to close. close_connection schedules the connection to be closed
# at the next available opportunity within the event loop. You may not assume that
# the connection is closed when close_connection returns. In particular, the framework
# will callback the unbind method for the particular connection at a point shortly
# after you call close_connection. You may assume that the unbind callback will
# take place sometime after your call to close_connection completes. In other words,
# the unbind callback will not re-enter your code "inside" of your call to close_connection.
# However, it's not guaranteed that a future version of EventMachine will not change
# this behavior.
#
# close_connection will silently discard any outbound data which you have
# sent to the connection using EventMachine::Connection#send_data but which has not
# yet been sent across the network. If you want to avoid this behavior, use
# EventMachine::Connection#close_connection_after_writing.
#
def close_connection after_writing = false
EventMachine::close_connection @signature, after_writing
end
# EventMachine::Connection#detach will remove the given connection from the event loop.
# The connection's socket remains open and its file descriptor number is returned
def detach
EventMachine::detach_fd @signature
end
def get_sock_opt level, option
EventMachine::get_sock_opt @signature, level, option
end
# EventMachine::Connection#close_connection_after_writing is a variant of close_connection.
# All of the descriptive comments given for close_connection also apply to
# close_connection_after_writing, with one exception: If the connection has
# outbound data sent using send_dat but which has not yet been sent across the network,
# close_connection_after_writing will schedule the connection to be closed after
# all of the outbound data has been safely written to the remote peer.
#
# Depending on the amount of outgoing data and the speed of the network,
# considerable time may elapse between your call to close_connection_after_writing
# and the actual closing of the socket (at which time the unbind callback will be called
# by the event loop). During this time, you may not call send_data to transmit
# additional data (that is, the connection is closed for further writes). In very
# rare cases, you may experience a receive_data callback after your call to close_connection_after_writing,
# depending on whether incoming data was in the process of being received on the connection
# at the moment when you called close_connection_after_writing. Your protocol handler must
# be prepared to properly deal with such data (probably by ignoring it).
#
def close_connection_after_writing
close_connection true
end
# EventMachine::Connection#send_data is only called by user code, never by
# the event loop. You call this method to send data to the remote end of the
# network connection. send_data is called with a single String argument, which
# may of course contain binary data. You can call send_data any number of times.
# send_data is an instance method of an object derived from EventMachine::Connection
# and containing your mixed-in handler code), so if you call it without qualification
# within a callback function, the data will be sent to the same network connection
# that generated the callback. Calling self.send_data is exactly equivalent.
#
# You can also call send_data to write to a connection other than the one
# whose callback you are calling send_data from. This is done by recording
# the value of the connection in any callback function (the value self), in any
# variable visible to other callback invocations on the same or different
# connection objects. (Need an example to make that clear.)
#
def send_data data
data = data.to_s
size = data.bytesize if data.respond_to?(:bytesize)
size ||= data.size
EventMachine::send_data @signature, data, size
end
# Returns true if the connection is in an error state, false otherwise.
# In general, you can detect the occurrence of communication errors or unexpected
# disconnection by the remote peer by handing the #unbind method. In some cases, however,
# it's useful to check the status of the connection using #error? before attempting to send data.
# This function is synchronous: it will return immediately without blocking.
#
#
def error?
EventMachine::report_connection_error_status(@signature) != 0
end
# #connection_completed is called by the event loop when a remote TCP connection
# attempt completes successfully. You can expect to get this notification after calls
# to EventMachine#connect. Remember that EventMachine makes remote connections
# asynchronously, just as with any other kind of network event. #connection_completed
# is intended primarily to assist with network diagnostics. For normal protocol
# handling, use #post_init to perform initial work on a new connection (such as
# send an initial set of data).
# #post_init will always be called. #connection_completed will only be called in case
# of a successful completion. A connection-attempt which fails will receive a call
# to #unbind after the failure.
def connection_completed
end
# Call #start_tls at any point to initiate TLS encryption on connected streams.
# The method is smart enough to know whether it should perform a server-side
# or a client-side handshake. An appropriate place to call #start_tls is in
# your redefined #post_init method, or in the #connection_completed handler for
# an outbound connection.
#
# #start_tls takes an optional parameter hash that allows you to specify certificate
# and other options to be used with this Connection object. Here are the currently-supported
# options:
#
# * :cert_chain_file :
# takes a String, which is interpreted as the name of a readable file in the
# local filesystem. The file is expected to contain a chain of X509 certificates in
# PEM format, with the most-resolved certificate at the top of the file, successive
# intermediate certs in the middle, and the root (or CA) cert at the bottom.
#
# * :private_key_file :
# takes a String, which is interpreted as the name of a readable file in the
# local filesystem. The file must contain a private key in PEM format.
#
# * :verify_peer :
# takes either true or false. Default is false. This indicates whether a server should request a
# certificate from a peer, to be verified by user code. If true, the #ssl_verify_peer callback
# on the Connection object is called with each certificate in the certificate chain provided by
# the peer. See documentation on #ssl_verify_peer for how to use this.
#
# === Usage example:
#
# require 'rubygems'
# require 'eventmachine'
#
# module Handler
# def post_init
# start_tls(:private_key_file => '/tmp/server.key', :cert_chain_file => '/tmp/server.crt', :verify_peer => false)
# end
# end
#
# EM.run {
# EM.start_server("127.0.0.1", 9999, Handler)
# }
#
#--
# TODO: support passing an encryption parameter, which can be string or Proc, to get a passphrase
# for encrypted private keys.
# TODO: support passing key material via raw strings or Procs that return strings instead of
# just filenames.
# What will get nasty is whether we have to define a location for storing this stuff as files.
# In general, the OpenSSL interfaces for dealing with certs and keys in files are much better
# behaved than the ones for raw chunks of memory.
#
def start_tls args={}
priv_key, cert_chain, verify_peer = args.values_at(:private_key_file, :cert_chain_file, :verify_peer)
[priv_key, cert_chain].each do |file|
next if file.nil? or file.empty?
raise FileNotFoundException,
"Could not find #{file} for start_tls" unless File.exists? file
end
EventMachine::set_tls_parms(@signature, priv_key || '', cert_chain || '', verify_peer)
EventMachine::start_tls @signature
end
# If SSL/TLS is active on the connection, #get_peer_cert returns the remote X509 certificate
# as a String, in the popular PEM format. This can then be used for arbitrary validation
# of a peer's certificate in your code.
#
# This should be called in/after the #ssl_handshake_completed callback, which indicates
# that SSL/TLS is active. Using this callback is important, because the certificate may not
# be available until the time it is executed. Using #post_init or #connection_completed is
# not adequate, because the SSL handshake may still be taking place.
#
# #get_peer_cert will return nil if:
#
# * EventMachine is not built with OpenSSL support
# * SSL/TLS is not active on the connection
# * SSL/TLS handshake is not yet complete
# * Remote peer for any other reason has not presented a certificate
#
# === Example:
#
# module Handler
#
# def post_init
# puts "Starting TLS"
# start_tls
# end
#
# def ssl_handshake_completed
# puts get_peer_cert
# close_connection
# end
#
# def unbind
# EventMachine::stop_event_loop
# end
#
# end
#
# EM.run {
# EventMachine::connect "mail.google.com", 443, Handler
# }
#
# Output:
# -----BEGIN CERTIFICATE-----
# MIIDIjCCAougAwIBAgIQbldpChBPqv+BdPg4iwgN8TANBgkqhkiG9w0BAQUFADBM
# MQswCQYDVQQGEwJaQTElMCMGA1UEChMcVGhhd3RlIENvbnN1bHRpbmcgKFB0eSkg
# THRkLjEWMBQGA1UEAxMNVGhhd3RlIFNHQyBDQTAeFw0wODA1MDIxNjMyNTRaFw0w
# OTA1MDIxNjMyNTRaMGkxCzAJBgNVBAYTAlVTMRMwEQYDVQQIEwpDYWxpZm9ybmlh
# MRYwFAYDVQQHEw1Nb3VudGFpbiBWaWV3MRMwEQYDVQQKEwpHb29nbGUgSW5jMRgw
# FgYDVQQDEw9tYWlsLmdvb2dsZS5jb20wgZ8wDQYJKoZIhvcNAQEBBQADgY0AMIGJ
# AoGBALlkxdh2QXegdElukCSOV2+8PKiONIS+8Tu9K7MQsYpqtLNC860zwOPQ2NLI
# 3Zp4jwuXVTrtzGuiqf5Jioh35Ig3CqDXtLyZoypjZUQcq4mlLzHlhIQ4EhSjDmA7
# Ffw9y3ckSOQgdBQWNLbquHh9AbEUjmhkrYxIqKXeCnRKhv6nAgMBAAGjgecwgeQw
# KAYDVR0lBCEwHwYIKwYBBQUHAwEGCCsGAQUFBwMCBglghkgBhvhCBAEwNgYDVR0f
# BC8wLTAroCmgJ4YlaHR0cDovL2NybC50aGF3dGUuY29tL1RoYXd0ZVNHQ0NBLmNy
# bDByBggrBgEFBQcBAQRmMGQwIgYIKwYBBQUHMAGGFmh0dHA6Ly9vY3NwLnRoYXd0
# ZS5jb20wPgYIKwYBBQUHMAKGMmh0dHA6Ly93d3cudGhhd3RlLmNvbS9yZXBvc2l0
# b3J5L1RoYXd0ZV9TR0NfQ0EuY3J0MAwGA1UdEwEB/wQCMAAwDQYJKoZIhvcNAQEF
# BQADgYEAsRwpLg1dgCR1gYDK185MFGukXMeQFUvhGqF8eT/CjpdvezyKVuz84gSu
# 6ccMXgcPQZGQN/F4Xug+Q01eccJjRSVfdvR5qwpqCj+6BFl5oiKDBsveSkrmL5dz
# s2bn7TdTSYKcLeBkjXxDLHGBqLJ6TNCJ3c4/cbbG5JhGvoema94=
# -----END CERTIFICATE-----
#
# You can do whatever you want with the certificate String, such as load it
# as a certificate object using the OpenSSL library, and check it's fields.
def get_peer_cert
EventMachine::get_peer_cert @signature
end
# send_datagram is for sending UDP messages.
# This method may be called from any Connection object that refers
# to an open datagram socket (see EventMachine#open_datagram_socket).
# The method sends a UDP (datagram) packet containing the data you specify,
# to a remote peer specified by the IP address and port that you give
# as parameters to the method.
# Observe that you may send a zero-length packet (empty string).
# However, you may not send an arbitrarily-large data packet because
# your operating system will enforce a platform-specific limit on
# the size of the outbound packet. (Your kernel
# will respond in a platform-specific way if you send an overlarge
# packet: some will send a truncated packet, some will complain, and
# some will silently drop your request).
# On LANs, it's usually OK to send datagrams up to about 4000 bytes in length,
# but to be really safe, send messages smaller than the Ethernet-packet
# size (typically about 1400 bytes). Some very restrictive WANs
# will either drop or truncate packets larger than about 500 bytes.
#--
# Added the Integer wrapper around the port parameter per suggestion by
# Matthieu Riou, after he passed a String and spent hours tearing his hair out.
#
def send_datagram data, recipient_address, recipient_port
data = data.to_s
EventMachine::send_datagram @signature, data, data.length, recipient_address, Integer(recipient_port)
end
# #get_peername is used with stream-connections to obtain the identity
# of the remotely-connected peer. If a peername is available, this method
# returns a sockaddr structure. The method returns nil if no peername is available.
# You can use Socket.unpack_sockaddr_in and its variants to obtain the
# values contained in the peername structure returned from #get_peername.
#
# require 'socket'
# module Handler
# def receive_data data
# port, ip = Socket.unpack_sockaddr_in(get_peername)
# puts "got #{data.inspect} from #{ip}:#{port}"
# end
# end
def get_peername
EventMachine::get_peername @signature
end
# #get_sockname is used with stream-connections to obtain the identity
# of the local side of the connection. If a local name is available, this method
# returns a sockaddr structure. The method returns nil if no local name is available.
# You can use Socket#unpack_sockaddr_in and its variants to obtain the
# values contained in the local-name structure returned from #get_sockname.
def get_sockname
EventMachine::get_sockname @signature
end
# Returns the PID (kernel process identifier) of a subprocess
# associated with this Connection object. For use with EventMachine#popen
# and similar methods. Returns nil when there is no meaningful subprocess.
#--
#
def get_pid
EventMachine::get_subprocess_pid @signature
end
# Returns a subprocess exit status. Only useful for #popen. Call it in your
# #unbind handler.
#
def get_status
EventMachine::get_subprocess_status @signature
end
# comm_inactivity_timeout returns the current value (float in seconds) of the inactivity-timeout
# property of network-connection and datagram-socket objects. A nonzero value
# indicates that the connection or socket will automatically be closed if no read or write
# activity takes place for at least that number of seconds.
# A zero value (the default) specifies that no automatic timeout will take place.
def comm_inactivity_timeout
EventMachine::get_comm_inactivity_timeout @signature
end
# Alias for #set_comm_inactivity_timeout.
def comm_inactivity_timeout= value
self.set_comm_inactivity_timeout value
end
# comm_inactivity_timeout= allows you to set the inactivity-timeout property for
# a network connection or datagram socket. Specify a non-negative float value in seconds.
# If the value is greater than zero, the connection or socket will automatically be closed
# if no read or write activity takes place for at least that number of seconds.
# Specify a value of zero to indicate that no automatic timeout should take place.
# Zero is the default value.
def set_comm_inactivity_timeout value
EventMachine::set_comm_inactivity_timeout @signature, value.to_f
end
# pending_connect_timeout is the duration after which a TCP connection in the connecting
# state will fail. It is important to distinguish this value from comm_inactivity_timeout,
# which looks at how long since data was passed on an already established connection.
# The value is a float in seconds.
def pending_connect_timeout
EventMachine::get_pending_connect_timeout @signature
end
# Alias for #set_pending_connect_timeout.
def pending_connect_timeout= value
self.set_pending_connect_timeout value
end
# set_pending_connect_timeout sets the duration after which a TCP connection in a
# connecting state will fail. Takes a float in seconds.
def set_pending_connect_timeout value
EventMachine::set_pending_connect_timeout @signature, value.to_f
end
# Reconnect to a given host/port with the current EventMachine::Connection instance
def reconnect server, port
EventMachine::reconnect server, port, self
end
# Like EventMachine::Connection#send_data, this sends data to the remote end of
# the network connection. EventMachine::Connection@send_file_data takes a
# filename as an argument, though, and sends the contents of the file, in one
# chunk. Contributed by Kirk Haines.
#
def send_file_data filename
EventMachine::send_file_data @signature, filename
end
# Open a file on the filesystem and send it to the remote peer. This returns an
# object of type EventMachine::Deferrable. The object's callbacks will be executed
# on the reactor main thread when the file has been completely scheduled for
# transmission to the remote peer. Its errbacks will be called in case of an error
# (such as file-not-found). #stream_file_data employs various strategems to achieve
# the fastest possible performance, balanced against minimum consumption of memory.
#
# You can control the behavior of #stream_file_data with the optional arguments parameter.
# Currently-supported arguments are:
# :http_chunks, a boolean flag which defaults false. If true, this flag streams the
# file data in a format compatible with the HTTP chunked-transfer encoding.
#
# Warning: this feature has an implicit dependency on an outboard extension,
# evma_fastfilereader. You must install this extension in order to use #stream_file_data
# with files larger than a certain size (currently 8192 bytes).
#
def stream_file_data filename, args={}
EventMachine::FileStreamer.new( self, filename, args )
end
# Enable notify_readable callbacks on this connection. Only possible if the connection was created
# using EM.attach and had notify_readable/notify_writable defined on the handler.
def notify_readable= mode
EventMachine::set_notify_readable @signature, mode
end
# Returns true if the connection is being watched for readability.
def notify_readable?
EventMachine::is_notify_readable @signature
end
# Enable notify_writable callbacks on this connection. Only possible if the connection was created
# using EM.attach and had notify_readable/notify_writable defined on the handler.
def notify_writable= mode
EventMachine::set_notify_writable @signature, mode
end
# Returns true if the connection is being watched for writability.
def notify_writable?
EventMachine::is_notify_writable @signature
end
# Pause a connection so that #send_data and #receive_data events are not fired until #resume is called.
def pause
EventMachine::pause_connection @signature
end
# Resume a connection's #send_data and #receive_data events.
def resume
EventMachine::resume_connection @signature
end
# True if the connect was paused using #pause.
def paused?
EventMachine::connection_paused? @signature
end
end
end