metasploit-framework/lib/rex/io/stream_server.rb

186 lines
3.3 KiB
Ruby

module Rex
module IO
###
#
# This mixin provides the framework and interface for implementing a streaming
# server that can listen for and accept stream client connections. Stream
# servers extend this class and are required to implement the following
# methods:
#
# accept
# fd
#
###
module StreamServer
##
#
# Abstract methods
#
##
##
#
# Default server monitoring and client management implementation follows
# below.
#
##
#
# This callback is notified when a client connects.
#
def on_client_connect(client)
if (on_client_connect_proc)
on_client_connect_proc.call(client)
end
end
#
# This callback is notified when a client connection has data that needs to
# be processed.
#
def on_client_data(client)
if (on_client_data_proc)
on_client_data_proc.call(client)
end
end
#
# This callback is notified when a client connection has closed.
#
def on_client_close(client)
if (on_client_close_proc)
on_client_close_proc.call(client)
end
end
#
# Start monitoring the listener socket for connections and keep track of
# all client connections.
#
def start
self.clients = []
self.listener_thread = Thread.new {
monitor_listener
}
self.clients_thread = Thread.new {
monitor_clients
}
end
#
# Terminates the listener monitoring threads and closes all active clients.
#
def stop
self.listener_thread.kill
self.clients_thread.kill
self.clients.each { |cli|
close_client(cli)
}
end
#
# This method closes a client connection and cleans up the resources
# associated with it.
#
def close_client(client)
if (client)
clients.delete(client)
begin
client.close
rescue IOError
end
end
end
##
#
# Callback procedures.
#
##
#
# This callback procedure can be set and will be called when new clients
# connect.
#
attr_accessor :on_client_connect_proc
#
# This callback procedure can be set and will be called when clients
# have data to be processed.
#
attr_accessor :on_client_data_proc
#
# This callback procedure can be set and will be called when a client
# disconnects from the server.
#
attr_accessor :on_client_close_proc
protected
attr_accessor :clients # :nodoc:
attr_accessor :listener_thread, :clients_thread # :nodoc:
#
# This method monitors the listener socket for new connections and calls
# the +on_client_connect+ callback routine.
#
def monitor_listener
begin
sd = Kernel.select([ fd ])
# Accept the new client connection
if (sd[0].length > 0)
cli = accept
next unless cli
# Insert it into some lists
self.clients << cli
on_client_connect(cli)
end
rescue
elog("Error in stream server listener monitor: #{$!}")
rlog(ExceptionCallStack)
end while true
end
#
# This method monitors client connections for data and calls the
# +on_client_data+ routine when new data arrives.
#
def monitor_clients
begin
if (clients.length == 0)
Rex::ThreadSafe::sleep(0.2)
next
end
sd = Rex::ThreadSafe.select(clients)
sd[0].each { |fd|
begin
on_client_data(fd)
rescue
elog("Error in stream server client monitor: #{$!}")
rlog(ExceptionCallStack)
ensure
close_client(fd)
end
}
rescue
elog("Error in stream server client monitor: #{$!}")
rlog(ExceptionCallStack)
end while true
end
end
end
end