Class: Net::Ping::ICMP

### Home Classes Methods

### In Files

- lib/net/ping/icmp.rb

### Parent

Net::Ping

### Methods

- ::new
- #bind
- #data_size=
- #ping
- #ping?
- #pingecho

### Files

- ping.txt

### Class/Module Index

Quicksearch

- Net
- Net::Ping
- Net::Ping::External
- Net::Ping::HTTP
- Net::Ping::ICMP
- Net::Ping::TCP
- Net::Ping::UDP
- Net::Ping::WMI
- Object

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# Net::Ping::ICMP

The Net::Ping::ICMP class encapsulates an icmp ping.

### Constants

ICMP_ECHO
ICMP_ECHOREPLY
ICMP_SUBCODE

### Attributes

data_size[R]

Returns the data size, i.e. number of bytes sent on the ping. The default size is 56.

### Public Class Methods

new(host=nil, port=nil, timeout=5) click to toggle source

Creates and returns a new Ping::ICMP object. This is similar to its superclass constructor, but must be created with root privileges (on UNIX systems), and the port value is ignored.

    # File lib/net/ping/icmp.rb, line 30
    def initialize(host=nil, port=nil, timeout=5)
      raise 'requires root privileges' if Process.euid > 0

      if File::ALT_SEPARATOR
        unless Win32::Security.elevated_security?
          raise 'requires elevated security'
        end
      end

      @seq = 0
      @bind_port = 0
      @bind_host = nil
      @data_size = 56
      @data = ''

      0.upto(@data_size){ |n| @data << (n % 256).chr }

      @ping_id = (Thread.current.object_id ^ Process.pid) & 0xffff

      super(host, port, timeout)
      @port = nil # This value is not used in ICMP pings.
    end

### Public Instance Methods

bind(host, port = 0) click to toggle source

Associates the local end of the socket connection with the given `host` and `port`. The default port is 0.

    # File lib/net/ping/icmp.rb, line 64
    def bind(host, port = 0)
      @bind_host = host
      @bind_port = port
    end

data_size=(size) click to toggle source

Sets the number of bytes sent in the ping method.

    # File lib/net/ping/icmp.rb, line 55
    def data_size=(size)
      @data_size = size
      @data = ''
      0.upto(size){ |n| @data << (n % 256).chr }
    end

ping(host = @host) click to toggle source

Pings the `host` specified in this method or in the constructor. If a host was not specified either here or in the constructor, an ArgumentError is raised.

    # File lib/net/ping/icmp.rb, line 73
    def ping(host = @host)
      super(host)
      bool = false

      socket = Socket.new(
        Socket::PF_INET,
        Socket::SOCK_RAW,
        Socket::IPPROTO_ICMP
      )

      if @bind_host
        saddr = Socket.pack_sockaddr_in(@bind_port, @bind_host)
        socket.bind(saddr)
      end

      @seq = (@seq + 1) % 65536
      pstring = 'C2 n3 A' << @data_size.to_s
      timeout = @timeout

      checksum = 0
      msg = [ICMP_ECHO, ICMP_SUBCODE, checksum, @ping_id, @seq, @data].pack(pstring)

      checksum = checksum(msg)
      msg = [ICMP_ECHO, ICMP_SUBCODE, checksum, @ping_id, @seq, @data].pack(pstring)

      begin
        saddr = Socket.pack_sockaddr_in(0, host)
      rescue Exception
        socket.close unless socket.closed?
        return bool
      end

      start_time = Time.now

      socket.send(msg, 0, saddr) # Send the message

      begin
        Timeout.timeout(@timeout){
          while true
            io_array = select([socket], nil, nil, timeout)

            if io_array.nil? || io_array[0].empty?
              @exception = "timeout" if io_array.nil?
              return false
            end

            ping_id = nil
            seq = nil

            data = socket.recvfrom(1500).first
            type = data[20, 2].unpack('C2').first

            case type
              when ICMP_ECHOREPLY
                if data.length >= 28
                  ping_id, seq = data[24, 4].unpack('n3')
                end
              else
                if data.length > 56
                  ping_id, seq = data[52, 4].unpack('n3')
                end
            end

            if ping_id == @ping_id && seq == @seq && type == ICMP_ECHOREPLY
              bool = true
              break
            end
          end
        }
      rescue Exception => err
        @exception = err
      ensure
        socket.close if socket
      end

      # There is no duration if the ping failed
      @duration = Time.now - start_time if bool

      return bool
    end

Also aliased as: ping?, pingecho
ping?(host = @host) click to toggle source
Alias for: ping
pingecho(host = @host) click to toggle source
Alias for: ping

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