SPC and Crossbow John DeHart jdd@arl.wustl.edu January 10, 2001 WUGS Kits Workshop Washington 1 Acknowledgements Special Thanks to: Sumi Choi Anshul Kantawala Fred Kuhns Samphel Norden Jyoti Parwatikar Ed Spitznagel Tilman Wolf Ken Wong Also: Tom Chaney Dave Richard Berkley Shands January 10, 2001 WUGS Kits Workshop Washington 2 page 1
Crossbow Tutorial (Tuesday) January 10, 2001 WUGS Kits Workshop Washington 3 Status 18 Participants in the Crossbow Tutorial Morning talks to introduce NetBSD kernel topics Kernel programming guidelines Crossbow system architecture Anatomy of a plugin Utitilies Afternoon of Exercises Start with a pre-built plugin that printed the received packet Step-by-step build up to an Monitoring Protocol (MonP) plugin» Using some WU-provided utility functions for manipulating packets Used MonP plugin to create 2 instances to monitor in two directions Multiple people/groups got through all the exercises January 10, 2001 WUGS Kits Workshop Washington 4 page 2
Example: Processing with a Plugin Does this packet Match the Filter? Vers HLen TOS Total length ID Socket Flags Fragment Offset TTL Protocol Header Checksum Layer Source Address Destination Address Source Port Destination Port... Packet Payload TCP Processing User Kernel Input Filter (Intf,P,SA,DA,SP,DP) Forward NO Output Gate YES Queue Interface Plugin Code January 10, 2001 WUGS Kits Workshop Washington 5 Review: Router Plugins Vocabulary 6-tuple: src_addr, dest_addr, protocol, interface, src_port, dst_port flow: packet stream that is identified by a specific 6-tuple flow table: cache of existing flow information loadable kernel module: executable code which can be dynamically loaded into the NetBSD kernel and subsequently executed. gate: spot in the NetBSD processing code where Router Plugin modules can be executed. plugin: A loadable kernel module (lkm) that can be associated with a Router Plugin gate. instance: An instantiation of a plugin. filter: A 6-tuple, possibly containing wildcards. filter table: For each dynamic gate, there may be a number of filters. The collection of these filters is referred to as a filter table. dag: Filter tables are implemented as a directed acyclic graph (dag). January 10, 2001 WUGS Kits Workshop Washington 6 page 3
Router Plugins Router Plugins = = Crossbow This is NOT Commercial Software Router Plugins is Kernel level programming Currently works with NetBSD 1.4.1 Moving to a new version of NetBSD takes about 2 weeks for us Linux Port Distribution Plans? Initial distribution» NetBSD install CD» non-install CD» tar files via web pages Updates» tar files» cvs January 10, 2001 WUGS Kits Workshop Washington 7 Router Plugins Issues, Questions, Problems Ports? Port to NetBSD 1.5.x Port to Linux Distribution plans? Options processing options processing is done BEFORE our first gate» and then calls ip_forward() without getting to our first gate new gate before options new gate specifically when there are options» U. Kentucky cm print_filter it has problems, we ll look into it freeing instances before deregistering filters crashed for one group, we ll try to reproduce it and fix it. January 10, 2001 WUGS Kits Workshop Washington 8 page 4
Router Plugins Issues, Questions, Problems cm utility has a painful interface we are already working on a perl-based interface Misconception about forwarding being dependent on your plugin and filter General filters pick up packets accordingly Our gate and hence our plugin was in ip_forward We did not process packets destined for the router host When you rebuild your plugin, you still have to reload it changing it on disk, doesn t change it in the kernel!! Crossbow does work with the APIC and the SPC. January 10, 2001 WUGS Kits Workshop Washington 9 SPC Tutorial (Monday) January 10, 2001 WUGS Kits Workshop Washington 10 page 5
SPC Hardware: SPC as a PC» How do they each boot? SPC Hardware Components The Smart Port Card» What roles do they play? SPC Software SPC Specific Kernel Modifications Building a Kernel Loading Kernel onto SPC to execute it Initiating Kernel execution Configuring Devices January 10, 2001 WUGS Kits Workshop Washington 11 Tutorial Recap 16 Participants in the SPC Tutorial Morning talks to introduce SPC Hardware SPC Software SPC Utilities Afternoon of Exercises Download and boot a pre-built kernel Build your own kernel Build your own file system and kernel Configure your PC and SPC for Route between your SPC and a neighboring group s SPC Multiple groups got through all the exercises January 10, 2001 WUGS Kits Workshop Washington 12 page 6
SPC Architecture Addr/Data Ctrl Cache CPU Ctrl North- Bridge Addr/Data/Ctrl DRAM Intel Embedded Module PCI Bus INIT NMI Intr RTC PIC PIT APIC UART1 UART2 UART1 Interface UART2 Interface BIOS ROM System FPGA Link Interface Switch Interface January 10, 2001 WUGS Kits Workshop Washington 13 SPC Components APIC» PCI Bus Master Pentium Embedded Module 166 MHz MMX Pentium Processor» L1 Cache: 16KB Data, 16KB Code L2 cache: 512 KB NorthBridge - 33 MHz, 32 bit PCI Bus» PCI Bus Master System FPGA» PCI Bus Slave Xilinx XC4020XLA-1 FPGA 20K Equivalent Gates ~ 75% used January 10, 2001 WUGS Kits Workshop Washington 14 page 7
SPC Components (continued) Memory EDO DRAM 64MB (Max for current design) SO DIMM Switch Interface - 1 Gb Utopia Link Interface - 1 Gb Utopia UART Two Serial Ports» NetBSD system console» TTY port January 10, 2001 WUGS Kits Workshop Washington 15 SPC Tutorial Issues, Questions, Problems Working with SPC includes working with WUGS previous experience with GBNSC/Jammer was limited for some Serial cables and what would happen with 8 SPCs? Utilities for debugging netstat tcpdump APIC readcounts Jammer: read vcxtcc Can we run Linux on the SPC? discussion? January 10, 2001 WUGS Kits Workshop Washington 16 page 8