Add bounty 3/4: disabling IPv4 in OS kernels

content/u/projects/jobs-hacks-bounties/contents.lr

@@ -90,3 +90,32 @@ wget/curl need to have IPv6 support to retrieve files via IPv6.
 Present a short video that successfully shows the updated upstream
 installer working in an IPv6 only network to install Alpine
 Linux. Bounty is __100 CHF__.
+
+### Bounty 3: Enable IPv6 only in the Linux kernel
+
+As you might remember, we created
+[a challenge to disable
+IPv4](https://ungleich.ch/en-us/cms/blog/2019/01/09/die-ipv4-die/) in
+your operating system. It turns out that as of 2020-05-01, the only
+operating system that truly can turn off IPv4, is FreeBSD.
+
+If you are into hacking the Linux kernel, we offer a __300 CHF__
+bounty to disable IPv4 in the Linux kernel. The bounty includes:
+
+* Create a patch against Linux mainline that completely disables IPv4
+* Ensure that make menuconfig/config can turn IPv4 off
+* Preparing the patch so that it can be included
+* Submission to LKML
+* Polishing patch so that it can be accepted
+* Patch is included in the Linux kernel source git repo
+* Show a short proof of concept that there is truly no more IPv4
+
+### Bounty 4: Enable IPv6 only in the OpenBSD kernel
+
+Very similar to bounty 3, we offer another __300 CHF__ bounty, if you
+can patch OpenBSD to fully disable IPv4. Requirements for collecting
+the bounty:
+
+* Create the necessary kernel patch
+* Get it included into the OpenBSD source tree
+* Show a short proof of concept that there is truly no more IPv4