kern: net80211: export sta assoc/disassoc via devctl

[kevans]

Summary

This sets up some new devd notify goodies. We don't seem to have any
net80211-related goodies, so I've structured it such that we have
net80211 as the overarching system, with the intention that subsystem
may be sta/ap/ibss/etc.

The only notifications currently added are:

net80211:sta:assoc, providing $vap, $ssid, $bssid
net80211:sta:disassoc, providing $vap, $ssid, $bssid

A potential use for this is triggering a backup script once a laptop
returns its home wifi network, for instance.

[adrian]

I'll +1 it to commit once they're moved to ieee80211_freebsd.c

sys/net80211/ieee80211_node.c

834

this should live in ieee80211_freebsd.c :-)

874

same as these; so the other OSes that consume our stack can just stub it out in their OS code.

[kevans]

Move platform-specific bits to ieee80211_freebsd.c

[kevans]

sys/net80211/ieee80211_proto.h

443

I might s/devctl/userland/ or something to that effect.

[imp]

this needs to at the very least be documented in devd.conf.5.
But the code otherwise looks decent... One real comment and one 'oh, yea, I should provide a better interface here' musing for future archaeologists

sys/net80211/ieee80211_freebsd.c

798

why the mixture of ' ' and 0x7e? shouldn't that be < 0x20 too?

807

I've often wanted a key value pair interface for this... But for another time.

[kevans]

sys/net80211/ieee80211_freebsd.c

798

I lifted it from elsewhere that ssids are printed, no objection to making it consistent.

807

Yeah, that'd be nice. I have another couple changes that add a devctl_notifyf that simplify a number of callers that just needed simple concatenation that can be expressed as a format string:

sys/arm/ti/am335x/am335x_pmic.c |  4 +---
sys/dev/acpica/acpi.c           |  5 ++---
sys/dev/asmc/asmc.c             |  4 +---
sys/dev/usb/usb_device.c        | 13 ++-----------
sys/geom/geom_dev.c             | 29 +++++++++++------------------
sys/geom/geom_disk.c            |  4 +---
sys/kern/kern_conf.c            | 13 +------------
sys/net/if.c                    |  6 +++---
sys/powerpc/powermac/pmu.c      |  6 ++----
9 files changed, 24 insertions(+), 60 deletions(-)

I -think- it's probably worth it? It's a modest win, at least.

[imp]

toss it up for review.