http://ocw.cs.pub.ro/courses/ 2026-05-14T02:59:01+03:00 http://ocw.cs.pub.ro/courses/ http://ocw.cs.pub.ro/courses/lib/tpl/arctic/images/favicon.ico text/html 2026-04-06T21:51:19+03:00 http://ocw.cs.pub.ro/courses/ep/labs/061/contents/tasks/ex1?rev=1775501479&do=diff 01. [20p] Primer / Reminder Pro tip #1man neovim.bashrc .zshrcmanneovim export MANPAGER='nvim +Man!' eBPF — quick recap Both tools in this section rely on eBPF under the hood, so it's worth a 60-second refresher before we start. eBPF (extended Berkeley Packet Filter) is a virtual instruction set built into the Linux kernel. You write a small program, the kernel verifies it for safety (no infinite loops, no bad memory access), JIT-compiles it to native code, and attaches it to a hook … text/html 2026-04-06T01:37:47+03:00 http://ocw.cs.pub.ro/courses/ep/labs/061/contents/tasks/ex2?rev=1775428667&do=diff 02. [20p] Network Exploration [5p] Task A - ARP vs ICMP The Address Resolution Protocol (ARP) resolves layer 2 addresses (MAC) from layer 3 addresses (e.g.: IP). Normally, all hosts are compelled to reply to ARP requests, but this can be fiddled with using tools such as arptables. You can show the currently known neighbors using iproute2. text/html 2026-04-07T02:13:43+03:00 http://ocw.cs.pub.ro/courses/ep/labs/061/contents/tasks/ex3?rev=1775517223&do=diff 03. [30p] Packets, where are you? Earlier in Ex. 1, we mentioned that eBPF is used for more than traffic filtering. Some of you may have heard of the eXpress Data Path (XDP) or the more recent eXpress Resubmission Path (XRP). Both of these are eBPF-powered shunts of kernel data paths that are used to optimize the system for very specific types of workloads. We'll return to these in a future lecture (and maybe a lab as well) since they can be considered advanced topics. For now, we'll focus on t… text/html 2026-04-07T12:47:07+03:00 http://ocw.cs.pub.ro/courses/ep/labs/061/contents/tasks/ex4?rev=1775555227&do=diff 04. [30p] Impact analysis of iptables rules In Lab 05 you used bpftrace exclusively via one-liners (-e flag). That works fine for quick investigations, but as your probes get more complex (multiple hooks, conditionals, helper functions) you'll want to write proper script files (.bt extension). text/html 2026-03-03T10:55:48+03:00 http://ocw.cs.pub.ro/courses/ep/labs/061/contents/tasks/ex5?rev=1772528148&do=diff 05. [10p] Feedback Please take a minute to fill in the feedback form for this lab.