Class: OverSIP::SIP::UdpConnection

Inherits:
Connection
  • Object
show all
Defined in:
lib/oversip/sip/listeners/udp_connection.rb

Direct Known Subclasses

IPv4UdpServer, IPv6UdpServer

Constant Summary

Constants included from MessageProcessor

MessageProcessor::MSG_TYPE

Instance Attribute Summary

Attributes inherited from Connection

#cvars

Instance Method Summary collapse

Methods inherited from Connection

#initialize, #open?, outbound_listener?, #receive_senderror, reliable_transport_listener?, #transport

Methods included from Logger

fg_system_msg2str, load_methods, #log_id

Constructor Details

This class inherits a constructor from OverSIP::SIP::Connection

Instance Method Details

#parse_message ⇒ Object 



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# File 'lib/oversip/sip/listeners/udp_connection.rb', line 29

def parse_message
  return false if @buffer.empty?

  buffer_str = @buffer.to_str

  # Quikly ignore single CRLF (widely used by SIP UDP clients as keep-alive).
  if buffer_str == CRLF
    @buffer.clear
    @state = :init
    return false
  end

  begin
    source_port, source_ip = ::Socket.unpack_sockaddr_in(get_peername)
  rescue => e
    log_system_crit "error obtaining remote IP/port (#{e.class}: #{e.message})"
    @buffer.clear
    @state = :init
    return false
  end

  case stun_res = ::OverSIP::Stun.parse_request(buffer_str, source_ip, source_port)
    # Not a STUN request so continue with SIP parsing.
    when nil
    # An invalid STUN request, log it and drop it.
    when false
      log_system_debug "invalid STUN message received (not a valid STUN Binding Request)"  if $oversip_debug
      @buffer.clear
      @state = :init
      return false
    # A valid STUN Binding Request so we get a response to be sent.
    when ::String
      log_system_debug "STUN Binding Request received, replying to it"  if $oversip_debug
      send_data stun_res
      @buffer.clear
      @state = :init
      return false
    end

  # Parse the currently buffered data. If parsing fails @parser_nbytes gets nil value.
  unless @parser_nbytes = @parser.execute(buffer_str, @parser_nbytes)
    # The parsed data is invalid, however some data could be parsed so @parsed.parsed
    # can be:
    # - SIP::Request
    # - SIP::Response
    # - nil (the message is so wrong that cannot be neither a request or response).
    if wrong_message = @parser.parsed
      log_system_warn "parsing error for #{MSG_TYPE[wrong_message.class]}: \"#{@parser.error}\""
    else
      log_system_warn "parsing error: \"#{@parser.error}\""
    end

    @buffer.clear
    @state = :init
    return false
  end

  unless @parser.finished?
    # The parsing has not finished.
    # If UDP it's invalid as per RFC 3261 a UDP datagram MUST contain an entire
    # SIP request or response. Note we also allow double CRLF in UDP. If just a
    # single CRLF arrives ignore it and clear the buffer.
    # Maybe the parser has gone enought data to determine if the unfinished
    # message is a SIP request or response, log it if so.
    # If not, then @parser.parsed returns nil and nothing is logged.
    unfinished_msg = @parser.parsed
    log_system_warn "ignoring not finished #{MSG_TYPE[unfinished_msg.class]} via UDP" if
      unfinished_msg.is_a? ::OverSIP::SIP::Request or unfinished_msg.is_a? ::OverSIP::SIP::Response
    # Clear the buffer, set :init state and wait for new messages.
    @buffer.clear
    @state = :init
    return false
  end

  # At this point we've got a SIP::Request, SIP::Response or :outbound_keepalive symbol.
  @msg = @parser.parsed

  # Clear parsed data from the buffer.
  @buffer.read(@parser_nbytes)

  # Received data is a Outbound keealive (also allowed in UDP however). Reply single CRLF.
  if @msg == :outbound_keepalive
    log_system_debug "Outbound keepalive received, replying single CRLF"  if $oversip_debug
    # Reply a single CRLF over the same connection.
    send_data CRLF
    # If UDP there could be invalid data after double CRLF CRLF, just ignore it
    # and clear the buffer. Set :init state and return false so we leave receive_data()
    # method.
    @buffer.clear
    @state = :init
    return false
  end

  @parser.post_parsing

  # Here we have received the entire headers of a SIP request or response. Fill some
  # attributes.
  @msg.connection = self
  @msg.transport = :udp
  @msg.source_ip = source_ip
  @msg.source_port = source_port
  @msg.source_ip_type = self.class.ip_type

  unless valid_message? @parser
    @buffer.clear
    @state = :init
    return false
  end

  add_via_received_rport if @msg.request?

  unless check_via_branch
    @buffer.clear
    @state = :init
    return false
  end

  # Examine Content-Length header.
  # There is Content-Length header.
  if cl = @msg.content_length and cl > 0
    # Body size is correct. Read it and clear the buffer.
    # Set :finished state and return true so message will be processed.
    if cl == @buffer.size
      @msg.body = @buffer.read.force_encoding(::Encoding::UTF_8)
      @buffer.clear
      @state = :finished
      return true
    # In UDP the remaining data after headers must be the entire body
    # and fill exactly Content-Length bytes. If not it's invalid. Reply
    # 400 and clear the buffer.
    else
      if @msg.request?
        unless @msg.sip_method == :ACK
          log_system_warn "request body size doesn't match Content-Length => 400"
          @msg.reply 400, "Body size doesn't match Content-Length"
        else
          log_system_warn "ACK body size doesn't match Content-Length, ignoring it"
        end
      else
        log_system_warn "response body size doesn't match Content-Length, ignoring it"
      end
      @buffer.clear
      @state = :init
      return false
    end
  # No Content-Length header or 0 value. However it could occur that the datagram
  # contains remaining unuseful data, in this case reply 400. If not
  # set :finished state and return true so message will be processed.
  else
    # Ensure there is no more data in the buffer. If it's ok set :finished
    # state and return true so message will be processed.
    if @buffer.size.zero?
      @state = :finished
      return true
    # Non valid remaining data in the UDP datagram. Reply 400.
    else
      if @msg.request?
        log_system_warn "request contains body but Content-Length is zero or not present => 400"
        @msg.reply 400, "request contains body but Content-Length is zero or not present"
      else
        log_system_warn "response contains body but Content-Length is zero or not present, ignoring it"
      end
      @buffer.clear
      @state = :init
      return false
    end
  end

end

#receive_data(data) ⇒ Object 



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# File 'lib/oversip/sip/listeners/udp_connection.rb', line 5

def receive_data data
  @buffer << data

  while (case @state
    when :init
      @parser.reset
      @parser_nbytes = 0
      @state = :message

    when :message
      parse_message

    when :finished
      if @msg.request?
        process_request
      else
        process_response
      end
      @state = :init
      false
    end)
  end  # while
end

#send_sip_msg(msg, ip, port) ⇒ Object

parse_headers



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# File 'lib/oversip/sip/listeners/udp_connection.rb', line 199

def send_sip_msg msg, ip, port
  send_datagram msg, ip, port
  true
end

#unbind(cause = nil) ⇒ Object 



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# File 'lib/oversip/sip/listeners/udp_connection.rb', line 205

def unbind cause=nil
  unless $!
    log_system_crit "UDP socket closed!!! cause: #{cause.inspect}"
  end
end