Quick overview

This file provides a quick summary on how files are organized, and where are the various documents to be read to start on the project.

The first document to read is here: https://perso.telecom-paristech.fr/pacalet/BasicOS/project.html If provides the main specification of the project.

Additionally, this repository contains two documents you ought to read:

• doc/ProjectSpecification.pdf: additional specifications on the project
• doc/Cstructuring.pdf: how to split a C project in different files.

Important note: to complete this project, you will have to modify

• student_client.c and student_server.c (provided files are examples)
• what you want in usrc and uinclude (provided files are examples)
• the Makefile in the root directory (in particular if you add libraries)
• nothing in include, lib, reset, tests, tools (provided files to be used as they are)

Files

Here is a summary of the sub-directories:

• Main dir: contains the main Makefile and this README
• bin/: generated executable files
• doc/: documents to be used to do the project
• include/: contains the provided .h files
• lib/: software libraries. to be used to simplify your coding
• reset/: see below the "reset" target of the Makefile
• tests/ contain a list of useful files to run tests. See below.
• tools/ contain our client and server, in binary format. You can use them to test your own client or your own server
• usrc/, uinclude/ are the C and h sources of an example of packet exchange. YOUR CODE should go there.
• ulib/ contains the library obtained when compiling the content of usrc/

Note: although student_client.h and student_server.h could be in uinclude (as you have to implement these libraries), they are in include as you must not modify these files.

Expected work: A quick summary

IMPLEMENT:

1. implement function student_server in usrc/student_server.c (ideally, this function should always return and should never exit, except if the command line is buggy)

2. implement function student_client in usrc/student_client.c (ideally, this function should always return and never exit, except if the command line is buggy)

   • return 0 makes client exit
   • return non zero makes client restart

Project compilation and execution

Once you have completed the above mentioned functions, do as follows to compile your code:

3. $ make

Then, to run your code:

4. type "./server" in bin/EDserver directory (Don't forget to provide arguments) => the server should print information on:

   • a port. Let's call it p.
   • an IP address. Let's call it a.

5. type "./client a p" in bin/EDclient directory (potentially with available options) where a and p are the address and port obtained at point 4 above. You can also use the name of the server machine as address.

Function student_server in student_server.c

The first parameter "channel" is a file descriptor (an already connected TCP/IP socket) from which you can read and write to communicate with the client.

A small example code is provided using "read" and "write" syscalls. You can also use "send" and "recv" (more complex)

Parameters argv and argc are the ones given as input to the main function of "server". Thus they contain the parameters given as argument to the server (point 4 above). If we wish, you can add new optional arguments to the server. "./server optional student parameters"

Function student_client in student_client.c

The first parameter "channel" is a file descriptor (a connected TCP/IP socket) on which you can read and write to communicate with the server.

A small example code is provided using "read" and "write" syscalls. You can also use "send" and "recv" (more complex)

Parameters argv and argc are the ones given as input to the main of the "client". Thus they contain the parameters given as argument to the client (point 5 above). If we wish, you can add new optional arguments to the server. "./client a p optional student parameters"

Provided functions

A small library is provided, which contains three functions that may be useful for your implementation:

• parse_commandline: you can use it to parse the command lines you get from the user at client side.

• pkt_string: you can use it to obtain a human readable version of the content of a packet header, which can be useful while debugging (useless in the final code).

• sort_dir: you can use it to sort the string describing the directory content (server response to ls) w.r.t. alphabetical order.

These functions are in the "utilities" library (include/utilities.h and lib/utilities.o)

Makefile

Main targets

As usual:

• "make all" builds the whole project, i.e., the client and server binaries in bin/EDclient and bin/EDserver. These binaries are also available in bin/ as links

• "make clean" removes all the files that have been created by the build

Moreover,

• "make bin/EDclient/client" only builds the client

• "make bin/EDserver/server" only builds the server

"test" target

"make test" runs a set of tests and prints OK or KO results on output. Most commands can be evaluated using these tests. However, some of them cannot be fully automatized as the expected result is not totally specified: they require a manual check.

To go further:

• The expected results of the tests are in tests/golden
• The generated results obtained by running the tests are in tests/result
• The results to be manually checked are generated in tests/to_check

The file tests/TESTS_DESCRIPTION.txt provide more information on tests.

"reset" target

"make reset" re-initializes the content of bin/EDclient and bin/EDserver with the content of reset/EDclient and reset/EDserver. Warning: all files that are not in reset/EDclient and reset/EDserver are removed from bin/EDclient and bin/EDserver, except the client and server executable files. This target is useful to easily restore the initial state. reset/EDclient and reset/EDserver directories contain the files to be restored with "reset". If you modify any file in this directory, restore its initial state before running the provided tests (see "test" target).