FreeBSD devfs

FreeBSD's devfs is where the kernel exposes attached hardware.
Rules can be defined to manage access, permissions, and automatic behaviour.

These rules can also be managed using the devfs command.

Documentation

man devfs

https://www.freebsd.org/cgi/man.cgi?query=devfs

Locations

/etc/devfs.conf	configure devfs rules loaded at boot
/etc/devfs.rules	configure devfs rules
/etc/defaults/devfs.conf	default devfs rules

Rules

NOTE:

careful to choose a high number, low numbers may conflict with freebsd's own rulesets, and may not load correctly

Rules get assigned a unique rule name/number within [devfsrules_*={rulenum}] blocks.
For example, [devfsrules_jail=100] is ruleset 100.

Custom rules are set within /etc/devfs.conf, and the default rules are established in /etc/defaults/devfs.conf.
Be sure to check the defaults before assigning rule numbers so you do not override them.

# ============
# Example Rule
# ============

# unhides common devices within jails
# if jail is configured to use this devfs rule
[devfsrules_jail=100]
add include $devfsrules_hide_all
add include $devfsrules_unhide_basic
add include $devfsrules_unhide_login
add path fuse unhide
add path zfs unhide