Home Networking (homenet) L. Ruminski
Internet-Draft M. Kutzner
Intended status: Informational A. Dymek
Expires: November 1, 2012 S. Kwiatkowski
M. Langa
Nicolaus
Copernicus
University
Faculty of
Mathematics
and Computer
Science
April 30, 2012
Grazed and Lightweight Open Protocol (GaLOP), v. 1.0
draft-ruminski-homenet-galop-proto-01
Status of this Memo
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This Internet-Draft will expire on November 1, 2012.
Abstract
This informational memo specifies a Grazed and Lightweight Open
Protocol (GaLOP), designed to exchange information within the
Hackney project [HACKNEY]. The document describes messages'
structures, defined message types used in the communication and
standard connection scenarios.
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Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with
respect to this document.
Introduction
The main goal for the protocol is to provide fast and reliable
communication between mobile devices (client software) and
Personal Computer (server software) via Bluetooth with minimal
data size needed to realize full functionality of the project.
The protocol was designed to be easy to extend - adding new
features and developing clients for other mobile platforms
should be as easy as possible.
Conventions used in this document
In examples, "CL:" and "SR:" indicate lines sent by the client
and server respectively.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL",
"SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
and "OPTIONAL" in this document are to be interpreted as
described in RFC-2119.
The following acronyms are used in this document:
SID - Session Identifier
GID - Gamepad functionality Identifier
DID - Device Identifier
UUID - Universally Unique Identifier
RFCOMM - Radio frequency communication protocol
J2ME - Java Platform, Micro Edition
MT - Message Data Type
PL - Payload
GaLOP in Bluetooth architecture model
By default, protocol uses the communication provided by RFCOMM.
It is assigned to the same middleware layer, as RFCOMM and to
application layer.
Message data definition
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The basic unit of the communication in Hackney project is the
message specified by MessageData class. The data is an array of
bytes.
Each message consists of 2-byte header and at least 2-byte
payload.
Byte 0 specifies the MT, byte 1 describes the SID in case of
already established connection or DID instead. Header length is
constant.
30-byte payload is intended for use only by messages of type
STRING_EXCHANGE. Other messages use 2-byte payload.
0
0 1 2 3 4
+-+-+-+-+-+-+-+-+
|MT |SID| PL |
+-+-+-+-+-+-+-+-+
Default message structure
0
0 1 2 3 4 5 6 7 8
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|MT |SID| PL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type STRING_EXCHANGE message structure
Message data types with description
General messages
CONNECTION_HELLO - 1
Description: Message used for connection
establishment.
Byte 1: DID, in case the message sent by client
or SID as a response from a server.
Payload: Ignored.
CONNECTION_GOODBYE - 2
Description: Connection termination.
Byte 1: Ignored.
Payload: Ignored.
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Mouse handler messages
MOUSE_NUMPAD_START_MOVE - 10
Description: Pressing a mouse button or starting
to move the mouse using the keypad or joystick.
Action is performed until message of type
MOUSE_NUMPAD_STOP is received.
Byte 1: SID.
Payload:
Byte 2: Key code as shown in Appendix A.
MOUSE_NUMPAD_STOP - 11
Description: Stopping the action associated with
the message of type MOUSE_NUMPAD_START_MOVE.
Byte 1: SID.
Payload:
Byte 2: Key code as shown in Appendix A.
MOUSE_SCREEN_PRESSED - 12
Description: Touching the screen before the
proper mouse action.
Byte 1: SID.
Payload:
Byte 2: 1,
Byte 3: Ignored.
MOUSE_SCREEN_MOVE - 13
Description: Moving the mouse, using touch
screen.
Byte 1: SID.
Payload:
Byte 2: Abscissa of the direction vector
in which the motion is performed,
Byte 3: Ordinate of the direction vector
in which the motion is performed.
MOUSE_SCREEN_RELEASED - 14
Description: Releasing the screen.
Byte 1: SID.
Payload:
Byte 2: 1,
Byte 3: Ignored.
Keyboard handler messages
KEYBOARD_PRESSED - 20
Description: Pressing the keyboard.
Byte 1: SID.
Payload:
Byte 2: ASCII of key value (in the case of
letters - ASCII code of capital letter),
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Byte 3: Modifiers.
Modifier is a special key, which change
the standard function of keys.
Available modifiers, with the values:
SHIFT: 2^0,
CTRL: 2^1,
ALT: 2^2,
ALTGR: 2^3,
SUPER/META/WIN: 2^4.
The combination of modifiers is
possible as the sum of their values -
for example, SHIFT and
ALT: 2^0 + 2^2 = 1 + 4 = 5.
It's not expected to use more than three
modifiers at the same time.
Hotkeys (keyboard shortcuts) and application management messages
HOTKEY_APPLIST_REQUEST - 30
Description: Requesting a list of applications
that have keyboard shortcuts defined on the
server side.
Byte 1: SID.
Payload:
Byte 2: 1,
Byte 3: Ignored.
HOTKEY_APPLIST_COUNT - 31
Description: Count of the items on application
list which is sent by the server to client.
Byte 1: SID.
Payload:
Byte 2: Count of items on the list of
apps,
Byte 3: Ignored.
HOTKEY_APP_CHOSED - 32
Description: Application selection from a list
received from the server.
Byte 1: SID.
Payload:
Byte 2: Number of the item from the list,
Byte 3: Ignored.
HOTKEY_APPHOTKEY_REQUEST - 33
Description: Requesting a list of keyboard
shortcuts for the chosed application.
Byte 1: SID.
Payload:
Byte 2: 1,
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Byte 3: Ignored.
HOTKEY_APPHOTKEY_COUNT - 34
Description: Count of the items on keyboard
shortcuts list which is sent by the server to
client.
Byte 1: SID.
Payload:
Byte 2: Count of items on the list of
hotkeys,
Byte 3: Ignored.
HOTKEY_USED - 35
Description: Number of used shortcut.
Byte 1: SID.
Payload:
Byte 2: Number of item from the list
of hotkeys,
Byte 3: Ignored.
STRING_EXCHANGE - 39
Description: The message used to transfer
applications and hotkeys descriptions. Is used
with HOTKEY_APPLIST_COUNT and
HOTKEY_APPHOTKEY_COUNT types messages.
As the only type uses extended payload, with
a length of 30 bytes.
Byte 1: SID.
Payload:
Bytes from 2 to 30: String encoded in
UTF-8 (15 characters, each encoded by
2 bytes).
Gamepad handler messages
GAMEPAD_ACCEL_MOVE - 40
Description: Begin action/motion by changing
the orientation
of the device against its default settings.
Measurement is
made by the accelerometer.
Byte 1: SID.
Payload:
Byte 2: the code corresponding to a
change in
orientation against the default
settings (landscape position):
Tilt the device to the left - 2,
Tilt the device to the right - 4,
Tilt the device to the left against
to its height - 8,
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Tilt the device to the right against
to its height - 16,
Tilt the device to the front - 32,
Tilt the device to the back - 64,
Byte 3: GID set by GAMEPAD_PLAYER_SET
type message.
GAMEPAD_ACCEL_STOP - 41
Description: Stopping the action performed by
GAMEPAD_ACCEL_MOVE type message.
Byte 1: SID.
Payload:
Byte 2: the code of the action which
should be terminated.
Values are identical to values
defined for GAMEPAD_ACCEL_MOVE type
message.
Byte 3: GID set by GAMEPAD_PLAYER_SET
type message.
GAMEPAD_KEY_PRESSED - 42
Description: The message used when special
function key is pressed. These keys work with
the accelerometer, together performing the
functionality of a gamepad controller.
Byte 1: SID.
Payload:
Byte 2: code of a special function key:
'A' button - 2,
'B' button - 4,
'C' button - 8,
'D' button - 16,
'E' button - 32,
'F' button - 64,
Byte 3: GID set by GAMEPAD_PLAYER_SET
type message.
GAMEPAD_KEY_RELEASED - 43
Description: Releasing a special function key.
Byte 1: SID.
Payload:
Byte 2: code of a special function key.
Values are identical to values defined
for GAMEPAD_KEY_PRESSED type message,
Byte 3: GID set by GAMEPAD_PLAYER_SET
type message.
GAMEPAD_PLAYER_SET - 44
Description: Message used to assign a set of
keys to
player actions or release a set by the player.
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Byte 1: SID.
Payload:
Byte 2: actual GID, or 0 if message
is a response,
Byte 3: new/proposed GID.
Defined Client Device Identifiers
Java Platform, Micro Edition - 1,
Android - 2.
Values from 3 to 9 are reserved for future clients for other
mobile platforms.
Usage scenarios
Connection establishment ("handshake")
CL: CONNECTION_HELLO with DID at byte 1 as above
SR: CONNECTION_HELLO with SID at byte 1 or
CONNECTION_GOODBYE
If Client was identified as Android Device:
SR: GAMEPAD_PLAYER_SET
Interaction with the server without response being sent by
the Server
CL: MOUSE_NUMPAD_START_MOVE or
MOUSE_NUMPAD_STOP or
MOUSE_SCREEN_PRESSED or
MOUSE_SCREEN_MOVE or
MOUSE_SCREEN_RELEASED or
KEYBOARD_PRESSED or
GAMEPAD_ACCEL_MOVE or
GAMEPAD_ACCEL_STOP or
GAMEPAD_KEY_PRESSED or
GAMEPAD_KEY_RELEASED
Hotkey usage
CL: HOTKEY_APPLIST_REQUEST
SR: HOTKEY_APPLIST_COUNT with count at byte 2 as LC
SR: STRING_EXCHANGE (LC times)
CL: HOTKEY_APP_CHOSED
CL: HOTKEY_APPHOTKEY_REQUEST
SR: HOTKEY_APPHOTKEY_COUNT w/count at byte 2 as HC
SR: STRING_EXCHANGE (HC times)
CL: HOTKEY_USED
Changing assigned player set
CL: GAMEPAD_PLAYER_SET with actual GID at byte 2 and
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proposed GID at byte 3
SR: GAMEPAD_PLAYER_SET with 0 at byte 2 and new GID
at byte 3, if available; 0 otherwise
Connection termination
CL: CONNECTION_GOODBYE
SR: CONNECTION_GOODBYE
Security Considerations
The Protocol was designed to be simple and lightweight.
The safety of its use depends on the security mechanisms
used by Bluetooth Technology and implementation of Hackney
Server.
The connection between client applications and server is not
possible if the UUIDs on both sides are not identical.
The computer must be discoverable. This forces a conscious
interaction from the user while using a computer.
Android-based devices require pairing with a computer before
connection will be made. Pairing J2ME-enabled devices depends
on Bluetooth implementation for Java virtual machine (but
still UUIDs must be the same). Default Hackney server
implementation uses so-called allow-list, allowing user to
control client access to the server (for example, prohibit
access to devices other than actually connected).
IANA Considerations
This specification makes no request of the IANA.
References
Informative References
[HACKNEY] <http://hackney.pl>
Acknowledgments
This document was prepared using 2-Word-v2.0.template.dot.
Appendix A. Keycodes with assigned Actions for 10 and 11 Message Types
49 - Left Mouse Button,
51 - Right Mouse Button,
53 or -1 - Move up,
56 or -2 - Move down,
52 or -3 - Move left,
54 or -4 - Move right.
Appendix B. Change History
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Changes from April 19, 2012 version to April 30, 2012 version:
Added default keycodes for 10 and 11 Message Types.
Author's Addresses
Lukasz Ruminski
Nicolaus Copernicus University
Faculty of Mathematics and Computer Science
Chopin Street 12/18
87-100 Torun
PL
Email: protazy@mat.umk.pl
Michal Kutzner
Nicolaus Copernicus University
Faculty of Mathematics and Computer Science
Chopin Street 12/18
87-100 Torun
PL
Email: kucyk@mat.umk.pl
Adrian Dymek
Nicolaus Copernicus University
Faculty of Mathematics and Computer Science
Chopin Street 12/18
87-100 Torun
PL
Email: include@mat.umk.pl
Szymon Kwiatkowski
Nicolaus Copernicus University
Faculty of Mathematics and Computer Science
Chopin Street 12/18
87-100 Torun
PL
Email: szymonk@mat.umk.pl
Marcin Langa
Nicolaus Copernicus University
Faculty of Mathematics and Computer Science
Chopin Street 12/18
87-100 Torun
PL
Email: iglis@mat.umk.pl
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