Class: OverSIP::WebSocket::TcpServer

Inherits:
EM::Connection
  • Object
show all
Includes:
Logger, DefaultPolicy
Defined in:
lib/oversip/websocket/listeners/tcp_server.rb

Constant Summary collapse

HEADERS_MAX_SIZE =

Max size (bytes) of the buffered data when receiving message headers (avoid DoS attacks).

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WS_MAGIC_GUID_04 = 
"258EAFA5-E914-47DA-95CA-C5AB0DC85B11".freeze
WS_VERSIONS = 
{ 7=>true, 8=>true, 13=>true }
HDR_SUPPORTED_WEBSOCKET_VERSIONS = 
[ "X-Supported-WebSocket-Versions: #{WS_VERSIONS.keys.join(", ")}" ]

Constants included from Logger

Logger::SYSLOG_POSIXMQ_MAPPING

Class Attribute Summary collapse

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from DefaultPolicy

#check_hostport, #check_origin, #check_request_uri

Methods included from Logger

close, #fatal, fg_system_msg2str, init_logger_mq, load_methods, #log_id, syslog_system_msg2str, syslog_user_msg2str

Constructor Details

#initialize ⇒ TcpServer

Returns a new instance of TcpServer.



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# File 'lib/oversip/websocket/listeners/tcp_server.rb', line 26

def initialize
  @http_parser = ::OverSIP::WebSocket::HttpRequestParser.new
  @buffer = ::IO::Buffer.new
  @state = :init
end

Class Attribute Details

.ip_type ⇒ Object

Returns the value of attribute ip_type.



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# File 'lib/oversip/websocket/listeners/tcp_server.rb', line 19

def ip_type
  @ip_type
end

.transport ⇒ Object

Returns the value of attribute transport.



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# File 'lib/oversip/websocket/listeners/tcp_server.rb', line 19

def transport
  @transport
end

Instance Attribute Details

#connection_log_id ⇒ Object (readonly)

Returns the value of attribute connection_log_id.



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# File 'lib/oversip/websocket/listeners/tcp_server.rb', line 23

def connection_log_id
  @connection_log_id
end

#remote_ip ⇒ Object (readonly)

Returns the value of attribute remote_ip.



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# File 'lib/oversip/websocket/listeners/tcp_server.rb', line 23

def remote_ip
  @remote_ip
end

#remote_ip_type ⇒ Object (readonly)

Returns the value of attribute remote_ip_type.



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# File 'lib/oversip/websocket/listeners/tcp_server.rb', line 23

def remote_ip_type
  @remote_ip_type
end

#remote_port ⇒ Object (readonly)

Returns the value of attribute remote_port.



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# File 'lib/oversip/websocket/listeners/tcp_server.rb', line 23

def remote_port
  @remote_port
end

#ws_app_klass ⇒ Object

Returns the value of attribute ws_app_klass.



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# File 'lib/oversip/websocket/listeners/tcp_server.rb', line 22

def ws_app_klass
  @ws_app_klass
end

#ws_protocol ⇒ Object

Returns the value of attribute ws_protocol.



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# File 'lib/oversip/websocket/listeners/tcp_server.rb', line 22

def ws_protocol
  @ws_protocol
end

Instance Method Details

#accept_ws_handshake ⇒ Object 



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# File 'lib/oversip/websocket/listeners/tcp_server.rb', line 222

def accept_ws_handshake
  sec_websocket_accept = Digest::SHA1::base64digest @http_request.hdr_sec_websocket_key + WS_MAGIC_GUID_04

  extra_headers = [
    "Upgrade: websocket",
    "Connection: Upgrade",
    "Sec-WebSocket-Accept: #{sec_websocket_accept}"
  ]

  if @websocket_protocol_negotiated
    extra_headers << "Sec-WebSocket-Protocol: #{@ws_protocol}"
  end

  if @websocket_extensions
    extra_headers << "Sec-WebSocket-Extensions: #{@websocket_extensions.to_s}"
  end

  @http_request.reply 101, nil, extra_headers

  # Set the WS framming layer and WS application layer.
  @ws_framing = ::OverSIP::WebSocket::WsFraming.new(self, @buffer)
  @ws_framing.ws_app = @ws_app_klass.new(self, @ws_framing)

  @state = :websocket_frames
  true
end

#check_http_request ⇒ Object 



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# File 'lib/oversip/websocket/listeners/tcp_server.rb', line 145

def check_http_request

  # HTTP method must be GET.
  if @http_request.http_method != :GET
    log_system_notice "rejecting HTTP #{@http_request.http_method} request => 405"
    http_reject 405
    return false
  end

  # "Sec-WebSocket-Version" must be 8.
  unless WS_VERSIONS[@http_request.hdr_sec_websocket_version]
    if @http_request.hdr_sec_websocket_version
      log_system_notice "WebSocket version #{@http_request.hdr_sec_websocket_version} not implemented => 426"
    else
      log_system_notice "WebSocket version header not present => 426"
    end
    http_reject 426, nil, HDR_SUPPORTED_WEBSOCKET_VERSIONS
    return false
  end

  # Connection header must include "upgrade".
  unless @http_request.hdr_connection and @http_request.hdr_connection.include? "upgrade"
    log_system_notice "Connection header must include \"upgrade\" => 400"
    http_reject 400, "Connection header must include \"upgrade\""
    return false
  end

  # "Upgrade: websocket" is required.
  unless @http_request.hdr_upgrade == "websocket"
    log_system_notice "Upgrade header must be \"websocket\" => 400"
    http_reject 400, "Upgrade header must be \"websocket\""
    return false
  end

  # Sec-WebSocket-Key is required.
  unless @http_request.hdr_sec_websocket_key
    log_system_notice "Sec-WebSocket-Key header not present => 400"
    http_reject 400, "Sec-WebSocket-Key header not present"
    return false
  end

  # Check Sec-WebSocket-Protocol.
  if @http_request.hdr_sec_websocket_protocol
    if @http_request.hdr_sec_websocket_protocol.include? @ws_protocol
      @websocket_protocol_negotiated = true
    else
      log_system_notice "Sec-WebSocket-Protocol does not contain a supported protocol but #{@http_request.hdr_sec_websocket_protocol} => 501"
      http_reject 501, "No Suitable WebSocket Protocol"
      return false
    end
  end

  # Check WebSocket policy.

  unless check_hostport(@http_request.host, @http_request.port)
    log_system_notice "host/port policy not satisfied (host=#{@http_request.host.inspect}, port=#{@http_request.port.inspect}) => 403"
    http_reject 403, "request host/port not satisfied"
    return false
  end

  unless check_origin(@http_request.hdr_origin)
    log_system_notice "'Origin' policy not satisfied (origin=#{@http_request.hdr_origin.inspect}) => 403"
    http_reject 403, "request 'Origin' not satisfied"
    return false
  end

  unless check_request_uri(@http_request.uri_path, @http_request.uri_query)
    log_system_notice "request URI path/query not satisfied (path=#{@http_request.uri_path.inspect}, query=#{@http_request.uri_query.inspect}) => 403"
    http_reject 403, "request URI path/query not satisfied"
    return false
  end

  @state = :accept_ws_handshake
  true
end

#http_reject(status_code, reason_phrase = nil, extra_headers = nil) ⇒ Object 



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# File 'lib/oversip/websocket/listeners/tcp_server.rb', line 250

def http_reject status_code, reason_phrase=nil, extra_headers=nil
  @http_request.reply(status_code, reason_phrase, extra_headers)
  close_connection_after_writing
  @state = :ignore
end

#ignore_incoming_data ⇒ Object 



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# File 'lib/oversip/websocket/listeners/tcp_server.rb', line 257

def ignore_incoming_data
  @state = :ignore  # The WS application needs to set the connection in :ignore state
                    # after sending a close frame to the client.
end

#parse_http_headers ⇒ Object 



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# File 'lib/oversip/websocket/listeners/tcp_server.rb', line 110

def parse_http_headers
  return false if @buffer.empty?

  # Parse the currently buffered data. If parsing fails @http_parser_nbytes gets nil value.
  unless @http_parser_nbytes = @http_parser.execute(@http_request, @buffer.to_str, @http_parser_nbytes)
    log_system_warn "parsing error: \"#{@http_parser.error}\""
    close_connection_after_writing
    @state = :ignore
    return false
  end

  # Avoid flood attacks in TCP (very long headers).
  if @http_parser_nbytes > HEADERS_MAX_SIZE
    log_system_warn "DoS attack detected: headers size exceedes #{HEADERS_MAX_SIZE} bytes, closing connection with #{remote_desc}"
    close_connection
    @state = :ignore
    return false
  end

  return false  unless @http_parser.finished?

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

  @http_request.connection = self
  @http_request.transport = self.class.transport
  @http_request.source_ip = @remote_ip
  @http_request.source_port = @remote_port
  @http_request.source_ip_type = @remote_ip_type ||= self.class.ip_type

  @state = :check_http_request
  true
end

#post_connection ⇒ Object 



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# File 'lib/oversip/websocket/listeners/tcp_server.rb', line 33

def post_connection
  begin
    @remote_port, @remote_ip = ::Socket.unpack_sockaddr_in(get_peername)
  rescue => e
    log_system_error "error obtaining remote IP/port (#{e.class}: #{e.message}), closing connection"
    close_connection
    @state = :ignore
    return
  end
  @connection_log_id = ::SecureRandom.hex(4)

  log_system_info "connection opened from " << remote_desc
end

#receive_data(data) ⇒ Object 



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# File 'lib/oversip/websocket/listeners/tcp_server.rb', line 75

def receive_data data
  @state == :ignore and return
  @buffer << data

  while (case @state
    when :init
      @http_request = ::OverSIP::WebSocket::HttpRequest.new
      @http_parser.reset
      @http_parser_nbytes = 0
      @bytes_remaining = 0
      @state = :http_headers

    when :http_headers
      parse_http_headers

    when :check_http_request
      check_http_request

    when :accept_ws_handshake
      accept_ws_handshake

    when :websocket_frames
      return false  if @buffer.size.zero?

      @ws_framing.receive_data
      false

    when :ignore
      false
    end)
  end  # while

end

#remote_desc(force = nil) ⇒ Object 



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# File 'lib/oversip/websocket/listeners/tcp_server.rb', line 48

def remote_desc force=nil
  if force
    @remote_desc = case @remote_ip_type
      when :ipv4  ; "#{@remote_ip}:#{@remote_port.to_s}"
      when :ipv6  ; "[#{@remote_ip}]:#{@remote_port.to_s}"
      end
  else
    @remote_desc ||= case self.class.ip_type
      when :ipv4  ; "#{@remote_ip}:#{@remote_port.to_s}"
      when :ipv6  ; "[#{@remote_ip}]:#{@remote_port.to_s}"
      end
  end
end

#unbind(cause = nil) ⇒ Object 



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# File 'lib/oversip/websocket/listeners/tcp_server.rb', line 63

def unbind cause=nil
  @local_closed = true  if cause == ::Errno::ETIMEDOUT

  log_msg = "connection from #{remote_desc} "
  log_msg << ( @local_closed ? "locally closed" : "remotely closed" )
  log_msg << " (cause: #{cause.inspect})"  if cause
  log_system_debug log_msg  if $oversip_debug

  @ws_framing.tcp_closed  if @ws_framing
end