Class: Nl::Raw::Protocol

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

Overview

Socket-wide wire behavior for a classic (netlink-raw) protocol.

Direct Known Subclasses

Genl::Protocol

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(protonum) ⇒ Protocol

Returns a new instance of Protocol.



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# File 'nl/lib/nl/raw/protocol.rb', line 37

def initialize(protonum)
  @protonum = protonum
end

Instance Attribute Details

#protonum ⇒ Object (readonly)

Returns the value of attribute protonum.



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# File 'nl/lib/nl/raw/protocol.rb', line 35

def protonum
  @protonum
end

Instance Method Details

#build_request(endpoint, kind, request_class, args) ⇒ Object 



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# File 'nl/lib/nl/raw/protocol.rb', line 87

def build_request(endpoint, kind, request_class, args)
  flags = Raw::NLM_F_REQUEST
  flags |= kind == :dump ? Raw::NLM_F_DUMP : Raw::NLM_F_ACK

  message = request_class.from_params(args)
  Request.new(type: endpoint.frame_type(request_class), flags:, message:)
end

#decode_frame(_endpoint, header, payload, message_class) ⇒ Object

Decodes one frame using the reply class associated with its sequence.



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# File 'nl/lib/nl/raw/protocol.rb', line 50

def decode_frame(_endpoint, header, payload, message_class)
  decoder = Decoder.new(payload)
  if header.type < Raw::NLMSG_MIN_TYPE
    case header.type
    when Raw::NLMSG_ERROR
      errno = decoder.get_value(Endian::Host::SINT)
      if errno.positive?
        raise ProtocolViolation, "expected zero or negative NLMSG_ERROR errno, got #{errno}"
      end

      errno.zero? ? AckFrame.new(header:) : ErrorFrame.new(header:, errno: -errno)
    when Raw::NLMSG_DONE
      return DoneFrame.new(header:, errno: nil) unless decoder.available?

      errno = decoder.get_value(Endian::Host::SINT)
      if errno.positive?
        raise ProtocolViolation, "expected zero or negative NLMSG_DONE errno, got #{errno}"
      end

      DoneFrame.new(header:, errno: errno.negative? ? -errno : nil)
    else
      UnknownFrame.new(header:)
    end
  else
    raise ArgumentError, 'reply class is required for a data message' unless message_class

    DataFrame.new(header:, message: message_class.decode(decoder, type: header.type))
  end
end

#decode_notification(endpoint, header, payload, message_class) ⇒ Object 



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# File 'nl/lib/nl/raw/protocol.rb', line 107

def decode_notification(endpoint, header, payload, message_class)
  decode_frame(endpoint, header, payload, message_class).message
end

#encode_message(encoder, _endpoint, request, seq:, pid:) ⇒ Object 



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# File 'nl/lib/nl/raw/protocol.rb', line 41

def encode_message(encoder, _endpoint, request, seq:, pid:)
  header = Raw::NlMsgHdr.new(0, request.type, request.flags, seq, pid)
  encoder.measure(Endian::Host::U16) do
    header.encode(encoder)
    request.message.encode(encoder)
  end
end

#notification_channel_key(endpoint) ⇒ Object 



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# File 'nl/lib/nl/raw/protocol.rb', line 95

def notification_channel_key(endpoint) = endpoint.definition

#notification_class(_endpoint, header, _payload, classes) ⇒ Object 



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# File 'nl/lib/nl/raw/protocol.rb', line 103

def notification_class(_endpoint, header, _payload, classes)
  classes[header.type]
end

#notification_frame?(_endpoint, header, _payload) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'nl/lib/nl/raw/protocol.rb', line 99

def notification_frame?(_endpoint, header, _payload)
  header.type >= Raw::NLMSG_MIN_TYPE
end

#notification_frame_key(header) ⇒ Object 



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# File 'nl/lib/nl/raw/protocol.rb', line 97

def notification_frame_key(header) = header.type

#notification_route_keys(_endpoint, classes) ⇒ Object 



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# File 'nl/lib/nl/raw/protocol.rb', line 96

def notification_route_keys(_endpoint, classes) = classes.keys

#send_message(socket, endpoint, request, seq:, pid:) ⇒ Object 



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

def send_message(socket, endpoint, request, seq:, pid:)
  encoder = Encoder.new
  encode_message(encoder, endpoint, request, seq:, pid:)
  socket.sendmsg(encoder.buffer.get_string, 0, Socket.sockaddr_nl(0, 0))
  nil
end