Three notes on OpenBSD.

README.md

@@ -108,5 +108,26 @@ to remove GCC-specific options. For example, on Solaris:
 The feature test macros on these systems isn't reliable, so you may also
 need to use `-D__EXTENSIONS__` in `CFLAGS`.
 
+### OpenBSD
+
+The man page needs to go into a different path for OpenBSD's `man` command:
+
+```
+diff --git a/Makefile b/Makefile
+index 119347a..dedf69d 100644
+--- a/Makefile
++++ b/Makefile
+@@ -14,8 +14,8 @@ endlessh: endlessh.c
+ install: endlessh
+        install -d $(DESTDIR)$(PREFIX)/bin
+        install -m 755 endlessh $(DESTDIR)$(PREFIX)/bin/
+-       install -d $(DESTDIR)$(PREFIX)/share/man/man1
+-       install -m 644 endlessh.1 $(DESTDIR)$(PREFIX)/share/man/man1/
++       install -d $(DESTDIR)$(PREFIX)/man/man1
++       install -m 644 endlessh.1 $(DESTDIR)$(PREFIX)/man/man1/
+
+ clean:
+        rm -rf endlessh
+```
 
 [np]: https://nullprogram.com/blog/2019/03/22/

util/openbsd/README.md

@@ -0,0 +1,34 @@
+# Running `endlessh` on OpenBSD
+
+## Covering IPv4 and IPv6
+
+If you want to cover both IPv4 and IPv6 you'll need to run *two* instances of
+`endlessh` due to OpenBSD limitations. Here's how I did it:
+
+- copy the `endlessh` script to `rc.d` twice, as `endlessh` and `endlessh6`
+- copy the `config` file to `/etc/endlessh` twice, as `config` and `config6`
+  - use `BindFamily 4` in `config`
+  - use `BindFamily 6` in `config6`
+- in `rc.conf.local` force `endlessh6` to load `config6` like so:
+
+```
+endlessh6_flags=-s -f /etc/endlessh/config6
+endlessh_flags=-s
+```
+
+## Covering more than 128 connections
+
+The defaults in OpenBSD only allow for 128 open file descriptors per process,
+so regardless of the `MaxClients` setting in `/etc/config` you'll end up with
+something like 124 clients at the most.
+You can increase these limits in `/etc/login.conf` for `endlessh` (and
+`endlessh6`) like so:
+
+```
+endlessh:\
+	:openfiles=1024:\
+	:tc=daemon:
+endlessh6:\
+	:openfiles=1024:\
+	:tc=daemon:
+```