Embed Size (px)
Citation preview
11/13/00 2
Home networking - Applications
Computer Interconnection
Control
11/13/00 3
Home networking technologies – Physical layer
Phoneline Powerline Ethernet Wireless
11/13/00 4
We wanted …
A Dynamic network Configuration Sharing resources Maintanence Control - from anywhere, anytime
11/13/00 5
Design issues
System Software
Hardware
Integrating hardware with software
11/13/00 6
Connection Technology
Jini
UPnP
11/13/00 7
Choices – Operating system
Linux
Unix variants
Windows
Guiding principle - Source availability, Synopsys’ network
11/13/00 8
Choices - Hardware
Verilog - Popular in North America
VHDL - Popular in Europe
Guiding principle - Time to Market
11/13/00 9
Verification
11/13/00 10
Co-verification using Eaglei
Link models
Instruction set simulator (ISS)
Live Target
11/13/00 11
GenericVSPRead32()
Eaglei
VSPMemory
/registers
1. Function call
2. Reaches VSP core thru eaglei
3. I/O bound instructions are
executed
Link model
Full visibility into the s/w execution process
Can test functionality of the design
11/13/00 12
ISS model
BFMISS
Actual Instructions
Full visibility into the processor and can execute assembly instrs
Good for debugging device drivers
11/13/00 13
Finally, each device
Application using Jini
JVM
Java Native Interface
Eaglei
Verilog Model
11/13/00 14
The Network
The services register their proxies with the lookup service, which is queried by the servlet for servicing the request from the client.
DEVICES
WWWCLIENT SERVLET
The Client clicks on the link leading to his URL requesting a service
Jini Lookup
1. Ask for the service
2. Get the service proxy
3. Interact with device
11/13/00 15
Jini Connection Technology
Java centric, distributed system designed for simplicity, flexibility and federation
Members of the federation agree on basic notions of trust, administration, identification and policy
Components - Services, Infrastructure and programming model
11/13/00 16
Components
Infrastructure Programming model
Services
JVM, RMI, Discovery/Join, Lookup service,
Java security
Java API,
Leasing, Transactions,
events
Printer, Refrigerator,
…
11/13/00 17
Key concepts
Lookup Service - Central bootstrapping mechanism for the system; helps find and resolve available services; service added to a lookup service by a pair of protocols - Discovery and Join
Leasing - Grant of guaranteed services over a time period
Security – JDK 1.2 Security model
11/13/00 18
Key concepts
Service object contains the Java programming language interface for the service, including the methods that users and applications will invoke to execute the service along with any other descriptive attributes.
11/13/00 19
Service Provider
Lookup Service
Lookup’s proxy
Service Provider
Lookup Service
Lookup’s proxy
11/13/00 20
Service Provider
Lookup Service
Lookup’s proxy
Lookup’s proxy
1. Get Lookup’s proxy from the lookup
DISCOVERY
11/13/00 21
Service Provider
Service Attributes
Lookup Service
Service Object
Service Attributes
Service Object
Lookup’s proxy
1. Get Lookup’s proxy from the lookup
2. Register service object with lookup
Lookup’s proxy
JOIN
11/13/00 22
Service Provider
Service Object
Service Attributes
Client
Lookup Service
Service Object
Service Attributes
3b. Interact with service
2b. Gets Service Proxy
1b. Query the Lookup service
11/13/00 23
Discovery and Join
Discovery - Process by which Jini applications find the lookup services that serve their communities.
Two forms - Serendipitous and hard wired.
Service initiated discovery, Lookup initiated discovery and direct discovery
11/13/00 24
Multicast Request (Service Initiated Discovery
Discoverer Lookup Service
1. Request Message (sent via UDP Multicast) IP Address - 224.0.1.85 port:4160via UDP Multicast) IP Address - 224.0.1.85 port:4160
2. Response Message – Service Proxy sent (Sent via TCP unicast)
11/13/00 25
Protocol Characteristics
Multicast UDP to IP - 224.0.1.85, port 4160
Interval - 5 secs. Seven rounds of multicast requests is recommended
Switch over to listening for announcements
Multicast Packet length never to exceed 512 bytes
11/13/00 26
Multicast Announcement (Lookup initiated discovery)
Discoverer Lookup Service
1. Announcements (sent via UDP
Multicast) IP Address - 224.0.1.84port:4160
3. Response Message(Sent via TCP unicast)
2. Request Message (sent via TCP unicast)
11/13/00 27
Protocol Characteristics
Multicast UDP to IP - 224.0.1.84, port 4160
Interval - 120 secs.
Multicast Packet length never to exceed 512 bytes.
11/13/00 28
Unicast Discovery (Direct Discovery)
Discoverer Lookup Service
1. Request Message (sent via TCP Unicast)
2. Response Message(Sent via TCP unicast,connects to 4160)
11/13/00 29
Join Protocol
Registering with the lookup service
The service object for the service is loaded into the lookup service
Get a lease - a period of time during which the lease grantor ensures that the holder of the lease will have access to some resource
11/13/00 30
Join Protocol
Client
Service Object
Service Attributes
Service Provider
Service Object
Service Attributes
Client
Lookup Service
Service Object
Service Attributes
11/13/00 31
Lookup Service Specification`
Programs that need a particular type of service can use the lookup service to find an instance.
Lookup service may provide a set of methods to enable incremental exploration of the collection.
Users are allowed to explore a collection of items down each of the major axes: attribute value and service type.
11/13/00 32
Lookup Service
Service Provider
Service Object
Service Attributes
Client
Lookup Service
Service Object
Service Attributes
3. Interact with service
2. Gets Service Proxy
1. Query the Lookup service
11/13/00 33
Device Architecture Alternatives
Device with computing power, memory, full JVM
Devices with specialized JVMs - need not include security manager, code verifier, or a number of other components
Clustering of devices with a Shared Virtual Machine
11/13/00 34
Full Jini Capable Device
Network
Proxy
Client
Service client
JVM
Hardware Implementation
Service Provider
Communication via RMI protocol
Private Protocol
11/13/00 35
Clustering of devices with a Jini capable proxy on the network
Network
Client
Service client Network Proxy
Communication via RMI protocol
ProxyJVM
Private Protocol
Dev 1
Dev 2
Dev 3
11/13/00 36
Conclusions
Encouraging Easy to put together
Discouraging Bad response time Jini + JVM (+ OS) is very heavy
11/13/00 37
The Network
The services register their proxies with the lookup service, which is queried by the servlet for servicing the request from the client.
DEVICES
WWWCLIENT SERVLET
The Client clicks on the link leading to his URL requesting a service
Jini Lookup
1. Ask for the service
2. Get the service proxy
3. Interact with deviceRefrigerator SmartPhone Printer
11/13/00 38
Finally, each device
Application using Jini
JVM
Java Native Interface
Eaglei
Verilog Model
11/13/00 39
Danger – if proxy overrides deserialization method
public class HostileFileClassifier2 implements FileClassifier, java.io.Externalizable {
public void readExternal(java.io.ObjectInput in) { if (java.io.File.pathSeparator.equals("/")) { // Unix - don't uncomment the next line! // Runtime.getRuntime().exec("/bin/rm -rf /"); } else { // DOS - don't uncomment the next line! // Runtime.getRuntime().exec("format c: /u"); } } public void writeExternal(java.io.ObjectOutput out) throws java.io.IOException{ out.writeObject(this); } } // HostileFileClassifier2
11/13/00 40
Security - Service
Specify Policy File as command line argument java –Djava.security.policy=“filename”
Sample Policy Filegrant { permission net.jini.discovery.DiscoveryPermission “printers"; // multicast request address permission java.net.SocketPermission "224.0.1.85", "connect,accept"; // multicast announcement address permission java.net.SocketPermission "224.0.1.84", "connect,accept";
// RMI connections permission java.net.SocketPermission "*.cs.wisc.edu:1024-", "connect,accept"; permission java.net.SocketPermission "130.102.176.249:1024-", "connect,accept"; permission java.net.SocketPermission "127.0.0.1:1024-", "connect,accept";};
11/13/00 41
Security - Client
grant { permission net.jini.discovery.DiscoveryPermission "*"; // multicast request address permission java.net.SocketPermission "224.0.1.85", "connect,accept"; // multicast announcement address permission java.net.SocketPermission "224.0.1.84", "connect,accept";
// RMI connections - DANGER // HTTP connections - this is where external code may come in - careful!!! permission java.net.SocketPermission "127.0.0.1:1024-", "connect,accept"; permission java.net.SocketPermission "*.cs.wisc.edu:1024-", "connect,accept"; permission java.net.SocketPermission "130.102.176.249:1024-", "connect,accept";
// HTTP connections - this is where external code may come in - careful!!! permission java.net.SocketPermission "127.0.0.1:80", "connect,accept"; permission java.net.SocketPermission "*.cs.wisc.edu:80", "connect,accept";
};
11/13/00 42
Bluetooth v/s Jini
Bluetooth - transport layer, allowing devices to find each other, to form a local network. It does not say what they do then
Jini - application layer, allowing services and clients to use each other
Complementary
11/13/00 43
Co-verification
11/13/00 44
Clustering of multiple devices (physical option)
Network
Service client
Communication via RMI protocol
Proxy
Client
Service Provider
JVM
Private Protocol
Dev 1
Dev 2
Dev 3
11/13/00 45
Leasing Characteristics
A lease is a period of time during which the lease grantor ensures that the holder of the lease will have access to some resource
A lease holder can request that a lease be renewed. If not renewed, the lease simply expires
