SHISA: The IPv6 Mobility Framework for BSD Operating Systems

Transcription

1 SHISA: The IPv6 Mobility Framework for BSD Operating Systems IPv6 Today Workshop 2nd August Bucharest, Romania Keiichi Shima / Internet Initiative Japan Inc. Ryuji Wakikawa, Koshiro Mitsuya and Keisuke Uehara / Keio Univeristy Tsuyoshi Momose / NEC Corporation

2 Contents Objectives SHISA Design Goals Implementation Conclusion

3 Objectives Deploy IPv6 mobility A free working code as a reference code is important for deployment ex1) the TCP/IP code by UCB ex2) the KAME IPv6 code This presentation introduces our implementation and its design

4 Mobile IPv6 Overview Mobile Node moves to a foreign network

5 Mobile IPv6 Overview Binds CoA and HoA and creates bi-dir tunnel

6 Mobile IPv6 Overview Traffic goes though the tunnel

7 Mobile IPv6 Overview Confirms ownership of HoA/CoA and sends Update

8 NEMO BS Overview Registers both HoA and Mobile Network Prefix

9 SHISA Design Goals Separation of signaling and data forwarding processing Flexibility of network device selection Adaptability to various movement scenarios Extensibility Minimum modification of the kernel

10 Implementation Supported Features System Configuration Program Organization, Node Configuration and Diagram Message Passing System Movement Detector Extensions

11 Supported Features Mobile IPv6 (RFC3775 and RFC3776) functions as Mobile Host, Home Agent with Route Optimization NEMO BS (RFC3963) functions as Mobile Router and Home Agent Multiple Care-of Addresses Registration IPv4 Mobile Network Prefix Registration

12 Program Organization SHISA consists of 6 programs mnd had cnd babymdd mrd nemonetd Mobile Host Functions Home Agent Functions (for both Mobile IPv6 and NEMO BS) Route Optimization Function A simple movement detector Mobile Router Functions Tunnel setup for NEMO BS

13 Node Configuration Selection of running programs decides the node type For Mobile Host mnd, babymdd and cnd (if RO as a CN is required) For Home Agent had, cnd (if RO as a CN is required) and nemonetd (if NEMO BS is required)

14 Node Configuration Required programs mnd mrd Mobile Host Mobile Router Home Agent babymdd Correspondent Node had nemonetd cnd Required for CN functions Required for NEMO functions

15 Diagram mnd babymdd mrd nemonetd cnd had user space kernel space Mobility Socket Routing Socket Forwarding Neighbor Discovery Address Routing Update Database Cache Database Routing Table

16 Diagram mnd babymdd mrd nemonetd cnd had user space kernel space Mobility Socket Routing Socket Forwarding Neighbor Discovery Address Routing Update Database Cache Database Routing Table Added modules Modified modules

17 Virtual Interfaces To hide the actual network interface from the mobility stack we introduced the following two virtual interfaces Mobility Interface (mip Interface) Represents Home Network NEMO tunnel Interface (nemo Interface) Represents NEMO bi-dir tunnel

18 Virtual Interfaces Mobile Host/Router just binds the logical home address and the current care-of address No specific information of the specific network I/F is used NEMO BS tunnel interface uses the current care-of address as its end-point address Can have multiple nemo I/Fs when multiple CoA is supported Home Address is assigned here mip0 Home Address is assigned here mip0 Unnumbered tunnel to the Home Agent via the current CoA nemo0 Mobile Host Mobile Router Physical Addresses (CoAs) are assigned here wi0 ed0 Physical Addresses (CoAs) are assigned here wi0 ed0

19 Message Passing A new communication domain socket (Mobility Socket) is designed Similar to the Routing Socket Mobility Socket provides 1. Kernel interface to application programs 2. Communication method between application programs

20 Message Passing The benefit of Mobility Socket Simple and Extensible interface using legacy socket interface Common and easy to use in BSD operating systems (and probably in other OSes too)

21 Message Passing Currently defined messages NODETYPE_INFO BC_ADD BC_UPDATE BC_REMOVE BC_FLUSH BUL_ADD BUL_UPDATE BUL_REMOVE BUL_FLUSH MD_INFO HOME_HINT RR_HINT BE_HINT DAD Configure the type of node (MN, MR, HA, CN) Add a Cache entry (same as above) Remove a Cache entry Clear all Cache entry Add a Update List entry (same as above) Remove a Update List entry Clear all Update List entry Movement information A hint message that a node returns home A hint message that a node receives a bi-directional tunneled packet A control message from kernel to send a Error message A control message to kernel to perform DAD for a specified address

22 Message Passing Ex. 1 Creating a Update List entry kernel mnd babymdd MD_INFO message with a new CoA Detect movement BU / BA exchange with Home Agent BUL_ADD message BUL entry creation

23 Message Passing Ex. 2 Creating a BUL entry in the NEMO BS case kernel mrd babymdd nemonetd MD_INFO message with a new CoA Detect Movement BUL_ADD message BU / BA exchange with Home Agent BUL_ADD message BUL entry creation NEMO tunnel setup

24 Message Passing Ex. 3 Notification from the kernel kernel mnd Receive tunneled packet RR_HINT message with the CN's address BUL_ADD message Perform the RR procedure BU (/ BA) exchange with the CN BUL entry creation

25 Message Passing mnd babymdd mrd nemonetd cnd had user space kernel space Mobility Socket Routing Socket Forwarding Neighbor Discovery Address Routing Update Database Cache Database Routing Table

26 Message Passing detect movement mnd babymdd mrd nemonetd cnd had user space kernel space Mobility Socket Routing Socket Forwarding Neighbor Discovery Address Routing Update Database Cache Database Routing Table

27 Message Passing BU/BA exchange mnd babymdd mrd nemonetd cnd had user space kernel space Mobility Socket Routing Socket Forwarding Neighbor Discovery Address Routing Update Database Cache Database Routing Table

28 Message Passing mnd babymdd mrd nemonetd cnd had user space kernel space Mobility Socket Routing Socket Forwarding Neighbor Discovery Address Routing Update Database Cache Database Routing Table

29 Message Passing mnd babymdd mrd nemonetd cnd had user space kernel space Mobility Socket Routing Socket Forwarding Neighbor Discovery Address Routing Update Database BUL creation Cache Database Routing Table

30 Message Passing mnd babymdd mrd nemonetd cnd had user space kernel space Mobility Socket Routing Socket Forwarding Neighbor Discovery Address Routing Update Database Cache Database Routing Table tunnel creation

31 Movement Detector SHISA only provides a simple movement detector implementation as babymdd Just perform NUD (Neighbor Unreachability Detection) against the router that sent the prefix information of the current care-of address (CoA) Sends MD_INFO message if the router becomes unreachable Movement detector can be replaceable based on the requirements of service providers

32 Extensions Multiple Care-of Addresses Registration based on draft-wakikawa-mobileipmultiplecoa-04 Assign a unique identifier to each NEMO tunnel and use multiple NEMO tunnel I/Fs IPv4 Network Prefix Registration based on draft-shima-nemo-v4prefix-01 Implemented by extending nemonetd program

33 Conclusion Designed the mobility stack as to provide the following characteristics Signal/Data processing separation Flexible network adapter usage using virtual I/Fs Adaptive movement detection mechanism Extensible system design Small kernel modification Implemented the stack to satisfy the above requirements The code is freely available from the KAME project Future plans Be compliant with the IPv6 Forum Logo program More advanced features, e.g. DSMIPv6, HA-HA