src VS frr

The OpenBSD project released 7.4 of their OS on 16 Oct 2023 as their 55th release 💫

Well since https://www.openbsd.org/ still says

> Only two remote holes in the default install, in a heck of a long time!

I'm assuming not, but I could always be mistaken.

> building a cat from scratch

> That would be an interesting project.

Here is the source code of the OpenBSD implementation of cat:

> https://github.com/openbsd/src/blob/master/bin/cat/cat.c

and here of the GNU coreutils implementation:

> https://github.com/coreutils/coreutils/blob/master/src/cat.c

Thus: I don't think building a cat from scratch or creating a tutorial about that topic is particularly hard (even though the HN audience would likely be interested in it). :-)

> I don't know how they define `MAX`, but I'm guessing it's a typical "a>b?a:b"

Indeed: https://github.com/openbsd/src/blob/master/sys/sys/param.h#L...

> Then `SYS_kbind` seems to be a signed int.

It's an untyped #define: https://github.com/openbsd/src/blob/master/sys/sys/syscall.h...

I believe your whole analysis is correct, that running an elf file with an openbsd.syscalls entry with .sysno > INT_MAX will allow an out-of-bounds write.

I can reproduce it. And this is the commit that causes the issue: https://github.com/openbsd/src/commit/d21788ce70be80e9c4ed0c52c149e01147c4a823

This doesn’t really change your conclusion, but I think that’s the wrong file. This is the real doas afaict: https://github.com/openbsd/src/blob/master/usr.bin/doas/doas...

Still just a tidy 1072 lines in that folder though.

I spent 5 minutes staring at your file trying to understand how on earth it does the things in the man page, but of course it doesn’t.

OpenBSD developers are making serious effort to kill off indirect syscalls, the base system is completely clean, take a look at the work Andrew Fresh did to adapt Perl. He write a complete syscall "dispatcher" or emulator for the Perl syscall function so that it calls the libc stubs.

https://github.com/openbsd/src/commit/312e26c80be876012ae979...

The ports tree is also being cleansed of syscall(2) usage, until they're all gone.

msyscall, pinsyscall, recent mandatory IBT/BTI, xonly. OpenBSD is making waves, but people aren't really seeing them yet.

Actually, I got it wrong, too many vulnerabilities in flight. They did fix it: https://github.com/openbsd/src/commit/375ccafb2eb77de6cf240e...

FRR https://frrouting.org/ is another open source tool for a more Cisco style CLI syntax. You’d install that on top of most Linux distros.

Use a decent PC or three, use https://frrouting.org/ and see fast bgp convergence 8-)

Open source, check out freerouter (https://wiki.geant.org/display/RARE/Home) and FRR (https://frrouting.org/)

u/GamerLymx The setup goal was, originally, to set this up as a desktop testing router using FRRouting so I could experiment with some technologies I work with, namely OpenFabric without having to buy a $6k switch (Extreme Networks) as well as OSPF and EIGRP. However, I ran into some issues with setting up FRRouting and could not find sufficient information out there to overcome those. So I decided to just turn it into a plain router using NFTables, etc., when I ran into the issues with Netplan.

Has anyone ever setup FRRouting to connect to a consumer VPN such as NordVPN? I have been Googling but have come up empty so I am assuming it is not something that can be done. Just the same, I thought I would ask in case I am asking the question wrong in my searches.

Linux machine with 96G RAM, can do full internet table IPv4/IPv6 (dual stack) with FRR (https://frrouting.org)

Right, so it turns out that FRR (the routing plugin for opnsense) doesn't support multiple address familys in ospfv3. It is down as a feature request here and is closed as issue #303.