Lecture # 27 - Systems and Network Programming

1. Demonstrate Dr. Fawcett's C++ directory davigator package (Nav) This is very similar to the Rust (DirNav) package that he discussed and demonstrated in Lecture 26 (Monday 4/20). The Navigator is flexible (i.e. think reuse versus salvage) package for traversing the file system, and enabling the client (the programmer) to define application specific processing on files and directories without requiring a single modification to the Navigator code. Demonstrates polymorphic (Liskov substitutability) behavior using a C++ interface

1. nav.h -- directory navigator package interface
2. nav.cpp - package implementation and test stub

2. Review the MPL code for full duplex (bidirectional TCP socket comm ) The class Sender class encapsulates client-side message passing, while the Receiver and ClientHandler class encapsulate server-side message passing. Full duplex infers a bidirectional communication channel in which both the Sender and (derived) ClientHandler instances support GetMessage() and PostMessage() operations. The following picture illustrates the concept:

A network (file) copy program using the Full duplex MPL is available below: ( i.e. another version a file transfer service and a client have been developed as an example) atop the full duplex version of the MPL. The network file copy service is similar in concept to HW#8 (copyfileBlock), except it sends/receives files across the network one block at a time (as messages)

1. Full Duplex (Synchronous) network file copy server
2. network file copy client

Full Duplex Message Passing Library -- (version 2, libmpl.a)

1. Sender Package - client-side message passing
   • Sender.h - package interface
   • Sender.cpp - package library code + test stub: run ./SenderTest
2. Receiver Package - server-side message passing: listening server and ClientHandler service host
   • Receiver.h - package interface
   • Receiver.cpp - package library code + test stub: run ./ReceiverTest
3. ClientHandler Package - server-side message passing class for defining custom server processing. Register with Receiver
   • ClientHander.h - package interface
   • ClientHandler.cpp - package library code. ** See Receiver.cpp for test stub: run ./ReceiverTest

Download Lecture 27 code examples here

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Project 2 helpers - Please See Project 2 Statement for instructions: Project 2 statement

***Note:*** I’ve given lots of help.
All that you need to do to complete Project 2 is to supply remaining the code required in Messenger.cpp Specifically, you need complete functions:
MessageHandler::AppProc() and
bool SendMessage(const Message &message, const EndPoint &dstPeerEP)

Download Project 2 helper code here

For insight view the test stubs (bottom) of files: Sender.cpp and Receiver.cpp to see how you might implement these functions.
You are not required to use my helper code! You can build all of your own code, but you do need to meet all of requirements specified in the Project statement (see MPL (Sender/Recveiver/ClientHandler) code below).

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File Server code example based on message passing
Demonstrates to how use message passing to support file transfer: sender/receive files a block at time (similar in ways to HW#8 - copyfileBlock) -- Half duplex MPL

1. cse384_file_server_executive.cpp -- concurrent file server
2. cse384_client_executive.cpp -- file server client app
3. README.txt -- getting started (compiling and running) file server example
4. Download File Server example code here

Message Passing Library (libmpl.a) - Half duplex

1. Sender Package - client-side message passing
   • Sender.h - package interface
   • Sender.cpp - package library code + test stub: run ./SenderTest
2. Receiver Package - server-side message passing: listening server and ClientHandler service host
   • Receiver.h - package interface
   • Receiver.cpp - package library code + test stub: run ./ReceiverTest
3. ClientHandler Package - server-side message passing class for defining custom server processing. Register with Receiver
   • ClientHander.h - package interface
   • ClientHandler.cpp - package library code. ** See Receiver.cpp for test stub: run ./ReceiverTest

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Sockets notes:

• Introduction to Sockets
• Sockets Presentation
• Message Passing Layer (concept)
• Resources:
  1. Geeks for Geeks Socket Tutorial
  2. Tutorialspoint: Sockets
  3. Introduction to Socket Programming
  4. Beej's Guide to Network Programming
• Network (TCP/IP) background:
  1. Overview of TCP/IP
  2. TCP 3-way Handshake
  3. TCP versus UDP
• Simple Socket Code Examples:
  1. Example #1: simple (single) client/server example
     1. client.c - simple client-side TCP socket demo
     2. server.c - simple server-side TCP socket demo
  2. Example #2: simple (concurrent) client/server example (using fork to start process to server each client request)
     1. client2.c - simple client-side TCP socket demo
     2. concurrent-server-fork.c - simple (concurrent -- fork) server demo
     3. run_clients.sh - A small bash script used to run multiple client instances
     4. netstat -t in the terminal
• Download socket code examples here

C/C++ examples: System calls, serialization, files and I/O

1. USNA (Systems Programming) lectures
1. User/Kernel space, System call Overview
2. File I/O: read, write, open system calls
3. Process creation and termination: I/O buffering
4. Fork, Exec system calls, Process management
5. Process Scheduling
2. Previous (Lecture 15) Notes and C/C++ Presentation Materials
1. C/C++ Introduction: Mike C. notes
2. C++ Survival Guide (basic syntax notes and important concepts): Dr. Fawcett
3. C and C++ compilation, memory, and computation models
4. Assessment of the C++
5. Discussion on the elements that comprise C and C++
6. Discussion on Packages and Modularity
7. Important linux/system header files
8. The structure and data flow in sytems is often documented with standard UML diagramming: You should be aware of it
3. Code Examples from 03/02 and 03/04
1. Demo stdout/stderr file streams, write system call
2. Demo Pass by value, Pass by reference, basic pointers and memory allocation (new/delete, malloc/free)
3. Demo C-style strings
4. Demo C++ std::strings
5. Demo File I/O in C (fopen/fgetc/fprintf,read lines, memory allocation with malloc etc.) Reading/Writing Text Files: C example
6. Demo File I/O in C++ (ifsteam/ofstream streams: Reading/Writing Text Files: C++ example
7. Demo structs, serialization, reading/writing binary files: C++ example
8. Demo reading/writing binary files in C (glibc: fopen/fread/fwrite/fseek etc) C example
9. Demo reading/writing binary files in C++ (fstream library: command line args, ifstream/oftstream etc.) C example
4. Type Serialization/Deserialization example
• books.h (package) header file
• book.cpp - package implementation file
• serialize.cpp - serialize/deserialize types
• Download serialize/deserialize types example
5. C Package example for HW # 7
• books.h - header ( books package interface)
• book.c - package implementation for books package
• bookutils.h - header (bookutils package interface)
• bookutils.c - code implementation for bookutils package
• executive.c - the client application (uses book and bookutils packages)
• Package example README (compiler build/run commands)
• Package diagram
• Download package example (C version) HW7_cpackage.tar.gz
6. Example of a real C++ package - supports linux file and directory operations (prior to C++ 17 file system)
• FileSystem package interface
• FileSystem package implementation
• Makefile - build(compile) the package
7. Lecture 14 Examples: Download

Note: You will need C and C++ compilers

• I will use GNU C/C++ (gcc/g++). The Linux Minit distro comes with gcc installed by default, but not g++
• Install g++ with the following command (Open terminal and type): sudo apt-get install g++
• You can install and use gcc/g++ on your Mac computer. Use this is option if you don't have a Linux distro

Code (C and C++ tutorial) Resources:

1. Really Nice C tutorial
2. Excellent C Programming Tutorial: Tutorialpoint
3. Another Excellent C Programming Tutorial(divided in basic and advanced topics): Learn-C.org
4. One of the best C++ tutorials I've seen: cpluspluss.com
5. Dr. Fawcett's Page on Getting Started with C++
6. A very good C++ tutorial: LearnCpp.com
7. Program memory layout
8. Pointers Tutorial
9. Stat system call
10. Stat man page
11. Compiling Programs using make (chapter 23): linux command line
12. Lectures from a well thought out systems programming course at USNA
13. Compilation, Linking and Loading article
14. A series of Systems Programming lectures from U.S. Naval Academy (USNA)
    • Introduction to C Programming and C strings
    • Pointers, Arrays, and Structures
    • C Strings, String Library, and Pointer Arithmetic
    • Arrays, Command Line Arguments, and Error Checking
    • Memory Allocation and Program Memory Layout
    • Dynamic Array Allocations and Data Representation Model
    • File Streams

Dr. Fawcett's developed resources:

Dr. Fawcett taught graduate software design courses here at Syracuse from 1990 - Spring 2019. Most of my software training was here at SU in Dr. Fawcett's courses from 2005-2019. In retirement he is continuing to develop (current) software training materials, most of which is hosted in his new github website available via the URLs below.

1. The C++ story provides detailed coverage of the C++ language: specifically how to utilize the language and its features effectively. The intent of the story is to meet people on individual level of experience. Beginning C++ programmers can begin to get handle on using the language, while experienced programmers can get detailed insight into the more advanced aspects.
   View the C++ story here


2. A series of the C++ videos corresponding to the C++ story
   can be viewed here


3. Previously taught (Spring 2019) graduate Object-oriented Design course using C++

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Environment Setup Notes:

1. Install VirtualBox
2. Install Linux Mint (based on Ubuntu -- I prefer MATE desktop, but many people like Cinnamon)
• Desktop Comparisons: MATE versus Cinnamon
• Install Guest Additions - device drivers and system applications that optimize the guest operating system for better performance and usability.
3. Enable "Shared Clipboard and Drag'nDrop": Settings -> Advanced
4. Configure shared folders, then run the following commands..
1. run: sudo usermod -a -G vboxsf `whoami`
2. run: sudo chown -R `whoami`:users name-of-mount-point
3. log out, and log back in
5. Update Mint (run): "sudo apt update && sudo apt upgrade -y"

Interesting Technologies related to Linux:

1. Kernel-based Virtual Machine (KVM) - turn Linux into a Hypervisor
2. Docker (Container Technology)
3. TCPDump & LIBPCAP
4. Extended Berkeley Packet Filter (eBPF)