Class: Arachni::RPC::Server::Dispatcher::Node

Inherits:
Object
  • Object
show all
Includes:
UI::Output
Defined in:
lib/arachni/rpc/server/dispatcher/node.rb

Overview

Dispatcher node class, helps maintain a list of all available Dispatchers in the grid and announce itself to neighbouring Dispatchers.

As soon as a new Node is fired up it checks-in with its neighbour and grabs a list of all available peers.

As soon as it receives the peer list it then announces itself to them.

Upon convergence there will be a grid of Dispatchers each one with its own copy of all available Dispatcher URLs.

Author:

Constant Summary collapse

DEFAULT_PING_INTERVAL = 
60

Instance Method Summary collapse

Methods included from UI::Output

#debug?, #debug_off, #debug_on, #disable_only_positives, #flush_buffer, #mute, #muted?, old_reset_output_options, #only_positives, #only_positives?, #print_bad, #print_debug, #print_debug_backtrace, #print_debug_pp, #print_error, #print_error_backtrace, #print_info, #print_line, #print_ok, #print_status, #print_verbose, #reroute_to_file, #reroute_to_file?, reset_output_options, #set_buffer_cap, #uncap_buffer, #unmute, #verbose, #verbose?

Constructor Details

#initialize(opts, logfile = nil) ⇒ Node

Initializes the node by:

  • Adding the neighbour (if the user has supplied one) to the peer list

  • Getting the neighbour’s peer list and appending them to its own

  • Announces itself to the neighbour and instructs it to propagate our URL to the others

Parameters:



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# File 'lib/arachni/rpc/server/dispatcher/node.rb', line 51

def initialize( opts, logfile = nil )
    @opts = opts
    @url  = "#{@opts.rpc_address}:#{@opts.rpc_port.to_s}"

    reroute_to_file( logfile ) if logfile

    print_status 'Initing grid node...'

    @dead_nodes = []
    @neighbours = Set.new
    @nodes_info_cache = []

    if neighbour = @opts.neighbour
        # add neighbour and announce him to everyone
        add_neighbour( neighbour, true )

        # grab the neighbour's neighbours
        peer = connect_to_peer( neighbour )
        peer.neighbours do |urls|
            fail "Neighbour '#{neighbour}' is unreachable." if urls.rpc_exception?
            urls.each { |url| @neighbours << url if url != @url }
        end
    end

    print_status( 'Node ready.' )

    log_updated_neighbours

    ::EM.add_periodic_timer( @opts.node_ping_interval || DEFAULT_PING_INTERVAL ) {
        ping
        check_for_comebacks
    }
end

Instance Method Details

#add_neighbour(node_url, propagate = false) ⇒ Object

Adds a neighbour to the peer list

Parameters:

  • node_url (String) —

    URL of a neighbouring node

  • propagate (Boolean) (defaults to: false) —

    wether or not to announce the new node to the ones in the peer list



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# File 'lib/arachni/rpc/server/dispatcher/node.rb', line 92

def add_neighbour( node_url, propagate = false )
    # we don't want ourselves in the Set
    return false if node_url == @url
    return false if @neighbours.include?( node_url )

    print_status 'Adding neighbour: ' + node_url

    @neighbours << node_url
    log_updated_neighbours
    announce( node_url ) if propagate

    connect_to_peer( node_url ).add_neighbour( @url, propagate ) do |res|
        next if !res.rpc_exception?
        add_dead_neighbour( node_url )
        print_status "Neighbour seems dead: #{node_url}"
    end
    true
end

#alive? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/arachni/rpc/server/dispatcher/node.rb', line 173

def alive?
    true
end

#info ⇒ Hash

Returns node specific info:

  • Bandwidth Pipe ID

  • Weight

  • Nickname

  • Cost

Returns:

  • (Hash) 


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# File 'lib/arachni/rpc/server/dispatcher/node.rb', line 163

def info
    {
        'url'        => @url,
        'pipe_id'    => @opts.pipe_id,
        'weight'     => @opts.weight,
        'nickname'   => @opts.nickname,
        'cost'       => @opts.cost
    }
end

#neighbours ⇒ Array

Returns all neighbour/node/peer URLs

Returns:



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# File 'lib/arachni/rpc/server/dispatcher/node.rb', line 116

def neighbours
    @neighbours.to_a
end

#neighbours_with_info(&block) ⇒ Object 



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# File 'lib/arachni/rpc/server/dispatcher/node.rb', line 120

def neighbours_with_info( &block )
    fail "This method requires a block!" if !block_given?

    @neighbours_cmp = ''
    if @nodes_info_cache.empty? || @neighbours_cmp != neighbours.to_s

        @neighbours_cmp = neighbours.to_s

        ::EM::Iterator.new( neighbours ).map( proc {
            |neighbour, iter|

            connect_to_peer( neighbour ).info {
                |info|

                if info.rpc_exception?
                    print_info "Neighbour seems dead: #{neighbour}"
                    add_dead_neighbour( neighbour )
                    log_updated_neighbours

                    iter.return( nil )
                else
                    iter.return( info )
                end
            }
        }, proc {
            |nodes|
            @nodes_info_cache = nodes.compact
            block.call( @nodes_info_cache )
        })
    else
        block.call( @nodes_info_cache )
    end
end