Search
40 results for “jschauma”
-
share/misc: acronyms.comp
jschauma: +RDS Reliable Datagram Sockets
http://cvsweb.netbsd.org/bsdweb.cgi/src/share/misc/acronyms.comp.diff?r1=1.428&r2=1.429
-
Advanced Programming in the #UNIX Environment
Week 01, Segment 01: Introduction
In this video lecture, we provide an introduction, discuss the purpose of the class, the syllabus, student expectations, as well as available resources.
Note: The videos in this series were mostly created in 2020. A few things have changed since then. Specifically, consult the course website for updates regarding the assignments.
-
Advanced Programming in the #UNIX Environment
Week 01, Segment 01: Introduction
In this video lecture, we provide an introduction, discuss the purpose of the class, the syllabus, student expectations, as well as available resources.
Note: The videos in this series were mostly created in 2020. A few things have changed since then. Specifically, consult the course website for updates regarding the assignments.
-
Feels like a Monday when you open the inbox and see "Linux kernel LPEs: ZcopyReaper (CVE-2026-43502) and 20 more".
https://www.openwall.com/lists/oss-security/2026/09/08/1
Various exploits/PoCs here:
https://github.com/NebuSec/CyberMeowfia/tree/main/security-researchWhile I don't know how widespread the use of RDS is, it's the "and 20 more" that kills me. Pretty much assuming shell access == root access at this point.
-
I still don't know how to handle AI in the CS classroom. I despise it, and I know it robs students of the opportunity to learn, but I also know that literally 100% of students _will_ use it in some form, regardless of course policy.
But students also need to learn how to use AI as a tool they supervise, control, and take advantage of instead of functioning as a meat proxy.
-
I still don't know how to handle AI in the CS classroom. I despise it, and I know it robs students of the opportunity to learn, but I also know that literally 100% of students _will_ use it in some form, regardless of course policy.
But students also need to learn how to use AI as a tool they supervise, control, and take advantage of instead of functioning as a meat proxy.
-
I still don't know how to handle AI in the CS classroom. I despise it, and I know it robs students of the opportunity to learn, but I also know that literally 100% of students _will_ use it in some form, regardless of course policy.
But students also need to learn how to use AI as a tool they supervise, control, and take advantage of instead of functioning as a meat proxy.
-
I still don't know how to handle AI in the CS classroom. I despise it, and I know it robs students of the opportunity to learn, but I also know that literally 100% of students _will_ use it in some form, regardless of course policy.
But students also need to learn how to use AI as a tool they supervise, control, and take advantage of instead of functioning as a meat proxy.
-
I still don't know how to handle AI in the CS classroom. I despise it, and I know it robs students of the opportunity to learn, but I also know that literally 100% of students _will_ use it in some form, regardless of course policy.
But students also need to learn how to use AI as a tool they supervise, control, and take advantage of instead of functioning as a meat proxy.
-
Hey kids! It's the start of the Fall semester, and I'm again teaching "Advanced Programming in the UNIX Environment".
The syllabus and all course materials including all code examples are available here:
https://stevens.netmeister.org/631/As usual, we'll be using #NetBSD as our main platform. All video lectures are public and available for free on YouTube:
https://www.youtube.com/playlist?list=PL0qfF8MrJ-jxMfirAdxDs9zIiBg2Wug0zI'll be posting individual lecture videos and related links in this thread throughout the semester.
-
Advanced Programming in the Unix Environment
The entire semester in one 157 slides deck: https://stevens.netmeister.org/631/f25.pdf
Full playlist on youtube of all 72 video lectures: https://www.youtube.com/watch?v=BsB9Cg6yJc4&list=PL0qfF8MrJ-jxMfirAdxDs9zIiBg2Wug0z
-
Advanced Programming in the Unix Environment
Week 13: Restricting Processes: Capabilities, Control Groups, Containers
In this video lecture, we're completing our discussion on how to restrict processes by looking at POSIX Capabilities, Linux Namespaces and Control Groups or "cgroups", and how these and the various other methods we've discussed in the last few videos allow us build containers like Docker or LXC.
-
Advanced Programming in the Unix Environment
Week 13: Restricting Processes: Processor Affinity and CPU Sets
In this video lecture, we discuss how we can restrict a process to a specific CPU or set of CPUs by way of "CPU pinning" or processor affinity and via CPU sets.
This lecture also exists as a blog post version as well:
https://www.netmeister.org/blog/cpu-pinning-and-sets.html -
Advanced Programming in the Unix Environment
Week 13: Restricting Processes: Process Priorities
In this video lecture, we revisit resource utilization by processes and how to set their CPU scheduling priority or "niceness". We discuss dynamic priority scheduling algorithms and the use of the nice(1) and renice(8) utilities.
-
Advanced Programming in the Unix Environment
Week 13: Restricting Processes: Restricted shells, Chroots, Jails
In this video lecture, we cover restricted shells, the chroot(2) syscall, and FreeBSD jails as ways to contain users and processes beyond file access controls.
-
Advanced Programming in the Unix Environment
Week 13: Restricting Processes: eUIDs, file flags, mount options, securelevels
In this video lecture, we look at new ways to restrict processes and even root itself. We revisit how we change effective UIDs using setuid, su(1) and sudo(8), and then cover file flags, certain mount options, and BSD securelevels.
-
Advanced Programming in the Unix Environment
Week 13: Restricting Processes: POSIX ACLs
This week we're diving deeper into ways to restrict processes. We begin with a review of standard Unix file permissions and then show how POSIX.1e Access Control Lists (ACLs) can be used for more fine-grained control.
-
Advanced Programming in the Unix Environment
Week 12: Cryptographic Basics
A segment on where and how cryptography can help solve certain security issues, including a few code examples for how to handle secrets/passwords (and how they linger in memory!), how to hash passwords, and the impact of poor pseudo-random number generators (with a blast from the past via the 2008 Debian weak keys).
Lecture slides:
https://stevens.netmeister.org/631/12-cryptobasics.pdf -
Advanced Programming in the Unix Environment
Week 12: Asynchronous and Memory Mapped I/O
With this video, we conclude our short series on advanced I/O topics with a quick summary of asynchronous (aio(7)) and memory mapped I/O (mmap(2)).
-
Advanced Programming in the Unix Environment
Week 12: Resource Locking
More miscellaneous "advanced I/O" - this time we discuss resource- and record locking using flock(2), lockf(3), and fcntl(2).
-
Advanced Programming in the Unix Environment
Week 12: Non-blocking I/O
Continuing our grab bag of miscellaneous topics, we briefly cover non-blocking I/O, whereby a system call that would normally block, waiting for I/O, returns immediately with an errno of EAGAIN or EWOULDBLOCK. We use the examples of I/O into a pipe (restricted to PIPE_BUF bytes at a time) or over the network using TCP with its buffer.
-
Advanced Programming in the Unix Environment
Week 12: syslog(3)
In this video lecture, we take a look at the standard Unix central logging facility, syslogd(8), and the syslog(3) library function. We show examples of system logs and how to separate messages by priority and level.
Below is an accurate capture of syslogd(8) in action:
-
Advanced Programming in the Unix Environment
I often see students confuse the "sizeof" operator and the "strlen" library function, especially when mixing fixed-sized buffers vs. pointers. So as a brief intermezzo, let's explain the difference between the two.
Based on that, I eventually ended up writing a manual page for 'sizeof', which is now included in #FreeBSD:
-
Advanced Programming in the Unix Environment
Week 11: Of Linkers and Loaders
Picking up where we left off when we talked about the compilation and linking process in Week 05, we now take a look at how a relocatable object file is turned into an executable by the dynamic linker (ld) and how an executable is loaded into memory by the run-time link-editor (ld.so or ld.elf_so).
-
Advanced Programming in the Unix Environment
Week 11: The Executable and Linkable Format
This week, we begin our exploration of shared libraries. We start with a look at the Executable and Linkable Format (ELF) for binary files such as executables, object files, core files and shared libraries. We'll use the hexdump(1) and readelf(1) utilities to better understand the format.
-
Advanced Programming in the Unix Environment
Week 10: Dæmon Processes
In this video lecture, we take a quick look at processes intended to run continuously and in the background: daemon processes. We'll also brush upon system start scripts and daemon/service conventions.
-
Advanced Programming in the Unix Environment
Week 9: I/O Multiplexing
With this video, we complete our discussion of interprocess communication and move from one-to-one communications towards a more typical client-server model with a server side process capable of handling multiple simultaneous clients. We accomplish this by using the select(2) syscall to handle synchronous I/O multiplexing.
-
Advanced Programming in the Unix Environment
Week 9: socket(PF_INET6, SOCK_STREAM, 0)
In this video, we demonstrate sockets using TCP to establish a sequenced, reliable, two-way byte stream over an #IPv6 network. Our good friend tcpdump(8) helps us inspect the packets on the wire to observe the 3-way handshake, data being exchanged, and connection tear down or observing a reset (RST) packet from the server if it's not listening on the port.
-
Advanced Programming in the Unix Environment
Week 9: socket(PF_INET, SOCK_DGRAM, 0)
We're finally moving on to network communications, and show how to communicate between hosts across the internet using datagram sockets in the PF_INET domain, that is, via UDP. We also observe the packets as they are sent by using the tcpdump(8) utility.
