Networks
This dotted-decimal identifier, e.g., 128 .10 .116 .31, uniquely designates every host on a network.
What is an IP address?
They’re the gateway between a user-space process and the OS kernel—everything from file I/O to fork begins with one of these.
What is a system call?
Fail to use strncpy() (or another bounded copy) and you open your program to this classic memory-safety vulnerability.
What is a buffer overflow?
When compiling code that uses sin() or sqrt(), you add this linker flag so GCC pulls in the math library.
What is -lm?
In a Makefile, every command in the “recipe” section must begin with this single whitespace character—not a space—or make will complain.
What is a tab?
It’s the distributed system that turns human-friendly names like google.com into IP addresses.
What is DNS?
create ↔ terminate ↔ execute ↔ wait are classic examples of this category of system calls.
What is process management?
In the read_login example with char buffer[8], overrunning the buffer lets an attacker overwrite this saved value—so the program never gets back to main().
void read_login(int x, int y) {
char buffer[8];
printf(“Enter login: “);
fscanf(stdin, “%s”, buffer);
printf(“Hello, %s. Code %d.%d\n”, buffer, x, y);
}
What is the return address?
C libraries come in two main forms: one gets baked into the executable at link-time, the other is loaded at run-time and ends in “.so”. Name either form.
What is a static library / shared (dynamic) library?
The GCC flag that tells the compiler to “optimize more, but without inflating code size” is -O followed by this digit.
Building reliability on top of IP, this protocol adds acknowledgments and retransmissions.
What is TCP?
Prototype: int ___(const char *pathname, int flags [, mode_t mode]); —name the system call.
What is open?
Modern OSes randomize stack, heap, and code addresses with this three-letter acronym—making buffer-overflow exploits far less predictable.
What is ASLR (Address Space Layout Randomization)?
A library that is copied into the executable during linking (instead of loaded later) is called this kind of library.
What is a static library?
The function you pass to signal(SIGALRM, …) so it runs whenever an alarm goes off is called a signal _____ (or simply a callback).
What is a handler?
A classic four-call sequence for a TCP server: create an endpoint, give it a name, mark it passive, then accept a connection. Name all four system calls in order.
What are socket(), bind(), listen(), accept()?
Forget to call this descriptor-closing system call and you’ll spring a file-descriptor leak.
What is close?
A quick way to keep a string copy inside its destination buffer is to use this length-limited cousin of strcpy. What function is it?
What is strncpy?
On Unix systems, almost every library file begins with this three-letter prefix—think ___m.so for the math library. What prefix is it?
What is lib?
printf, strcpy, and other standard C functions live in this shared object file—typically found as /usr/lib/____.so.
An endpoint for data exchange is fully identified by this two-part term: a 32-bit network number and a 16-bit local number (<1024 are privileged).
What is a socket address (IP address + port)?)
On x86-64, this single assembly instruction switches the CPU to kernel mode to service a system call.
What is syscall?
Attackers love this classic C function because it copies a string into a buffer without checking its size—perfect for triggering an overflow. Name the function.
What is strcpy?
To stop a header file from being included twice, we wrap its contents with #ifndef, #define, and #endif. What are these duplicate-include guards commonly called?
What are header guards?
In setting up a TCP server, this system call assigns a newly created socket to a local IP address and port before you can listen()
What is bind()?