Class: Nl::Protocols::Raw

Inherits:
Object
  • Object
show all
Defined in:
lib/nl/protocols/raw.rb

Overview

The raw Netlink protocol

Direct Known Subclasses

Genl

Defined Under Namespace

Modules: DataTypes Classes: Ack, AttributeSet, Done, Message

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, protonum) ⇒ Raw

Returns a new instance of Raw.



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# File 'lib/nl/protocols/raw.rb', line 15

def initialize(name, protonum)
  @name = name
  @protonum = protonum
end

Instance Attribute Details

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/nl/protocols/raw.rb', line 13

def name
  @name
end

#protonum ⇒ Object (readonly)

Returns the value of attribute protonum.



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# File 'lib/nl/protocols/raw.rb', line 13

def protonum
  @protonum
end

Instance Method Details

#decode_message(decoder, message_class) ⇒ Object 



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# File 'lib/nl/protocols/raw.rb', line 24

def decode_message(decoder, message_class)
  header = NlMsgHdr.decode(decoder)
  decoder.limit(header.len - Core::NLMSG_HDRLEN) do
    message_class.decode(decoder, header)
  end
end

#encode_message(encoder, message) ⇒ Object 



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# File 'lib/nl/protocols/raw.rb', line 20

def encode_message(encoder, message)
  message.encode(encoder)
end

#exchange_message(socket, type, request_class, reply_class, args) ⇒ Object

Parameters:

  • socket (Socket) —

    Netlink socket

  • type (:do, :dump) —

    Request type

  • request_class (Class) —

    Request message class

  • reply_class (Class) —

    Reply message class

  • args (Hash) —

    Request arguments



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# File 'lib/nl/protocols/raw.rb', line 80

def exchange_message(socket, type, request_class, reply_class, args)
  flags = Core::NLM_F_REQUEST
  flags |= type == :dump ? Core::NLM_F_DUMP : Core::NLM_F_ACK

  request = request_class.from_params(args)
  request.nlmsg_header.flags = flags
  seq_pid = send_message(socket, request)

  result = [] unless block_given?

  done = false
  begin
    recv_message(socket, seq_pid, reply_class) do |message|
      case message
      when Done, Ack
        done = true
      when Exception
        raise message
      else
        if block_given?
          yield message
        else
          result << message
        end
      end
    end
  end until done

  unless block_given?
    type == :dump ? result : result.first
  end
end

#recv_message(socket, seq_pid, message_class) ⇒ Object 



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# File 'lib/nl/protocols/raw.rb', line 39

def recv_message(socket, seq_pid, message_class)
  data, = socket.recvmsg

  decoder = Decoder.new(IO::Buffer.for(data))
  while decoder.available?(Core::NLMSG_HDRLEN)
    header = Core::NlMsgHdr.decode(decoder)
    decoder.align_to(Core::NLMSG_ALIGNTO)
    raise binding.irb unless [header.seq, header.pid] == seq_pid
    if header.type < Core::NLMSG_MIN_TYPE
      # Control messages
      case header.type
      when Core::NLMSG_ERROR
        errno = decoder.get_value(Endian::Host::SINT)
        if errno == 0
          yield Ack.new
        else
          yield SystemCallError.new(-errno)
        end
        decoder.skip(header.len - Core::NLMSG_HDRLEN - 4)
      when Core::NLMSG_DONE
        yield Done.new
        decoder.skip(header.len - Core::NLMSG_HDRLEN)
      else
        # just ignore NLMSG_NOOP and other unknown control messages
        decoder.skip(header.len - Core::NLMSG_HDRLEN)
      end
    else
      # Subsystem-specific messages
      decoder.limit(header.len - Core::NLMSG_HDRLEN) do
        decoder.align_to(Core::NLMSG_ALIGNTO)
        yield message_class.decode(decoder, header)
      end
    end
  end
end

#send_message(socket, message) ⇒ Object 



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# File 'lib/nl/protocols/raw.rb', line 31

def send_message(socket, message)
  seq_pid = socket.complete(message.nlmsg_header)
  encoder = Encoder.new
  encode_message(encoder, message)
  socket.sendmsg(encoder.buffer.get_string, 0, Socket.sockaddr_nl(0, 0))
  seq_pid
end