CMPUT 379代写、代写C/C++编程设计

日期：2022-03-23 11:05

Copyright Notice: Copyright by CMPUT 379. All rights reserved. Do not post any part on a

publicly-available Web site.

CMPUT 379 - Assignment #3 (10%)

Communicating Peer Processes using TCP Sockets and FIFOs (first draft)

Due: Monday, March 21, 2022, 09:00 PM

(electronic submission)

Objectives

This programming assignment is intended to give you experience in developing client-server programs

that utilize TCP sockets for communication over the Internet, FIFOs for communication

among peers, and I/O multiplexing (select or poll) for nonblocking I/O.

Details

In this assignment, you are asked to write a C/C++, called a3w22, that implements the transactions

performed by the simplified hypothetical data center network described in Assignment 2. As in

Assignment 2, each switch communicates with its neighbour switches using FIFOs. However,

unlike Assignment 2, the packet switches communicate with the master switch over TCP sockets.

The program can be invoked as a TCP server (simulating a master switch), or a TCP client (simulating

a packet switch) using:

% a3w22 master nSwitch portNumber

% a3w22 pswi dataFile (null|pswj) (null|pswk) IPlow-IPhigh serverAddress portNumber

where, in addition to the command line arguments in Assignment 2, the program uses the following

arguments:

• portNumber specifies the TCP port used by the server to listen to incoming connections.

(To minimize the chance of port number conflicts when running servers in the lab, use port

number 9xxx where xxx is the last 3 digits of your student ID number.)

• serverAddress is the IP address of the server’s host specified either as a symbolic name

(e.g., ui11.cs.ualberta.ca, or localhost), or in dotted-decimal notation (e.g.,

127.0.0.1).

Features from Assignment 2

Your a3w22 program should implement the following features (detailed in Assignment 2).

1. Data transmission among adjacent packet switches uses FIFOs. Each FIFO is named as

fifo-x-y where x 6= y, and x, y ∈ [1, MAX NSW] and MAX NSW = 7 switches. Such a FIFO

carries packets in the direction from switch x to switch y. For simplicity, you may create the

needed FIFOs before running the program.

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Copyright Notice: Copyright by CMPUT 379, U. of Alberta, course instructor (E. Elmallah). All rights reserved. Do not post any part on a

publicly-available Web site.

2. Each switch handles data from hosts in the specified IP range [IPlow-IPhigh], and each

IP address is ≤ MAXIP (= 1000).

3. Each row in a switch’s forwarding table stores a pattern-plus-action rule composed of the

following fields:

srcIP lo srcIP hi destIP lo destIP hi actionType actionVal pktCount

where actionType can be either forward or drop a matched packet.

4. Communication between switches uses messages stored in formatted packets. Each packet

has a type, and carries a message (except HELLO ACK packets). Your program should support

the packet types described in Assignment 2: HELLO, HELLO ACK, ASK, ADD, and RELAY.

5. When a3w22 is invoked to simulate a device (a packet switch or a master switch), the program

uses I/O multiplexing (e.g., select() or poll()) to handle I/O from the keyboard,

and the attached devices in a nonblocking manner. Each iteration of the main loop of a

device polls the keyboard for the info or exit commands, and polls other attached devices.

Executing the info and exit commands are done as in Assignment 2.

6. When a3w22 is invoked to simulate a packet switch, the program installs an initial rule in

its forwarding table:

srcIP lo srcIP hi destIP lo destIP hi actionType actionVal pktCount

= 0 = MAXIP = IPlow = IPhigh = FORWARD = 3 = 0

7. Upon receiving signal SIGUSR1, a switch displays the information specified in the info

command.

8. Data File: Each iteration of the main loop of a switch reads and processes a single line

from the data file (if the EOF has not been reached yet). The switch ignores empty lines,

comment lines, and lines specifying other handling switches. A packet header in the input

file is considered admitted if the line specifies the current switch. A delay line of the form

"pswi delay interval" where interval is an integer in milliseconds, specifies

that packet switch i should delay reading (and processing) the remaining part of the data file

for the specified time interval.

Note 1: During a delay period, the switch should continue monitoring and processing

keyboard commands and packets received from the attached devices.

Note 2: After reading all lines in the data file, the program continues to monitor

and process keyboard commands, and the incoming packets from neighbouring

devices.

New Features

In addition to implementing the above features from Assignment 2, your program should implement

the following new features.

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Copyright Notice: Copyright by CMPUT 379, U. of Alberta, course instructor (E. Elmallah). All rights reserved. Do not post any part on a

publicly-available Web site.

1. The master switch should detect if an attached packet switch closes its end of the socket

(e.g., because a switch has terminated unexpectedly). When such an event occurs, the master

switch should write a suitable message, e.g., "lost connection to psw3".

2. Unexpected termination of a packet switch should not cause any other device to stop functioning

properly in the new configuration.

3. Output: In addition to printing the output specified in Assignment 2 when the info, or

exit commands are issued to a switch, each device should print all received and transmitted

packets, as shown in Example output 3 of Assignment 2. Also as shown in Example 3, a

switch entering a delay interval (as may be specified by a line in the data file) should print a

message to this effect, e.g., "Entering a delay period for 300 millisec".

More Details

1. This is an individual assignment. Do not work in groups.

2. Only standard include files and libraries provided when you compile the program using gcc

or g++ should be used.

3. Although many details about this assignment are given in this description, there are many

other design decisions that are left for you to make. In such cases, you should make reasonable

design decisions that do not contradict what we have said and do not significantly

change the purpose of the assignment. Document such design decisions in your source code,

and discuss them in your report. Of course, you may ask questions about this assignment

(e.g., in the Discussion Forum) and we may choose to provide more information or provide

some clarification. However, the basic requirements of this assignment will not change.

4. When developing and testing your program, make sure you clean up all processes before

you logout of a workstation. Marks will be deducted for processes left on workstations.

Deliverables

1. All programs should compile and run on the lab machines (e.g., ug[00 to 34].cs.ualberta.ca)

using only standard libraries (e.g., standard I/O library, math, and pthread libraries are allowed).

2. Make sure your programs compile and run in a fresh directory.

3. Your work (including a Makefile) should be combined into a single tar archive ‘submit.tar’,

or ‘submit.tar.gz’.

(a) Executing ‘make’ or ‘make a3w22’ should produce the a3w22 executable file.

(b) Executing ‘make clean’ should remove unneeded files produced in compilation.

(c) Executing ‘make tar’ should produce the tar archive.

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Copyright Notice: Copyright by CMPUT 379, U. of Alberta, course instructor (E. Elmallah). All rights reserved. Do not post any part on a

publicly-available Web site.

(d) Your code should include suitable internal documentation of the key functions. If you

use code from the textbooks, or code posted on eclass, acknowledge the use of the

code in the internal documentation. Make sure to place such acknowledgments in close

proximity of the code used.

4. Typeset a project report (e.g., one to three pages either in HTML or PDF) with the following

(minimal set of) sections:

– Objectives: state the project objectives and value from your point of view (which may be

different from the one mentioned above)

– Design Overview: highlight in point-form the important features of your design

– Project Status: describe the status of your project; mention difficulties encountered in

the implementation

– Testing and Results: comment on how you tested your implementation

– Acknowledgments: acknowledge sources of assistance

5. Upload your tar archive using the Assignment #3 submission/feedback link on the course’s

web page. Late submission is available for 24 hours for a penalty of 10% of the points

assigned to the phase.

6. It is strongly suggested that you submit early and submit often. Only your last successful

submission will be used for grading.

Marking

Roughly speaking, the breakdown of marks is as follows:

20% : successful compilation of reasonably complete program that is: modular, logically organized,

easy to read and understand, includes error checking after important function calls,

and acknowledges code used from the textbooks or the posted lab material

05% : ease of managing the project using the makefile

65% : correctness of implementing the master switch and the switch modules and displaying the

specified outputs.

10% : quality of the information provided in the project report

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