Extended System Programming Laboratory

In this course we focus on low-level system programming principles. The labs are based on interaction with the LINUX operating system, mostly using C, but also some assembly language. Issues covered in the course are:

1. Processes, memory models, and interaction with the operating system.
2. A programmer’s introduction to C: storage types, pointers, structures.
3. The raw machine: basics of (x86) assembly language, linking to functions written in C.
4. Direct system calls: a programmer’s interface with system services.
5. User’s view of the Linux file system, processes, and access permissions.
6. Command interpreters: Unix “shell”.
7. “Binary” files: formats, manipulation.
8. The ELF format, linking and loading.

LAB 1 - Introduction to C Programming in a Unix (Linux 32 bits) Environment

Lab goals:

• C primer
• Parsing command-line arguments
• Undestanding character (ASCII) and hexadecimal encodings
• Implementing a debug mode for your program
• Introduction to standard streams (stdin, stdout, stderr)
• Simple stream IO library functions

LAB 2 - Program Memory and Pointers, Debugging and Simulating Object Oriented Programming

Lab goals:

• C primer - continued.
• Understanding storage addresses, introduction to pointers.
• Pointers to basic data types, to structures, and to functions.
• Simulating object-like behavior in C.

LAB 3 - C Programming: debugging, dynamic data structures: linked lists, patching binary files.

Lab goals:

• Pointers and dynamically allocated structures and the valgrind utility.
• Understanding data structures: linked lists in C.
• Basic access to "binary" files, with application: simplified virus detection in executable files.

LAB 4 - System calls, working with files

Lab goals:

• To get acquainted with the low-level interface to system calls.
• To understand how programs can work without the standard library.
• Basics of directory listings, through a first attempt at executable file viruses.
• Debugging programs via printouts (the idea of debug mode, continued).

LAB 5 - Implementing a Command Interpreter (Shell)

Lab goals:

• get acquainted with command interpreters ("shell") by implementing a simple command interpreter.
• Understand how Unix/Linux fork() and exec() work.
• Intruduction to Linux signals.

LAB 6 - Standard Input/Output Redirection, Introduction to Pipelines

Lab goals:

• To enrich the set of capabilities of your shell by implementing input/output redirection and pipelines. The shell will then be able to execute non-trivial commands such as "tail -n 2 in.txt| cat > out.txt", demonstrating the power of these simple concept.

LAB 7 - AWK Command

Lab goal:

• Learn awk syntax, records, fileds, line Separator and the overall picture of the awk command.

LAB 8 - ELF-Introduction with Code

Lab goals:

• Learn how to manipulate ELF files by writing a simplified version of the readelf program.
• Parsing the ELF file and extract useful information from it.
• Access the data in the section header table, and in the symbol table.
• Learn to use the mmap system call.

Lab 9: ELF - Virus (Architecture and SPlab)

Lab goal:

• In this lab, You are requested to write and run Proto program which will attach itself to executable files and infect them.