MFC r310891:

[net80211] add placeholders for the VHT action frame handling.

Upcoming vht support will register send/receive action handlers.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

net80211: fix more compiler warnings.

ieee80211.c:
add_chanlist(): 'error' variable will be uninitialized if
no channels were passed; return '0' instead.
ieee80211_action.c:
ieee80211_send_action_register(): drop 'break' after 'return'.
ieee80211_crypto_none.c:
none_encap(): 'keyid' is not used in non-debug builds; hide it
behind IEEE80211_DEBUG ifdef.
ieee80211_freebsd.c:
Staticize global 'ieee80211_debug' variable (used only in this
file).
ieee80211_hostap.c:
Fix a comment (associatio -> association).
ieee80211_ht.c:
ieee80211_setup_htrates(): initialize 'maxunequalmcs' to 0 to mute
compiler warning.
ieee80211_hwmp.c:
hwmp_recv_preq(): copy 'prep' between conditional blocks to fix
-Wshadow warning.
ieee80211_mesh.c:
mesh_newstate(): remove duplicate 'ni' definition.
mesh_recv_group_data(): fix -Wempty-body warning in non-debug
builds.
ieee80211_phy.c:
ieee80211_compute_duration(): remove 'break' after panic() call.
ieee80211_scan_sta.c:
Hide some TDMA-specific macros under IEEE80211_SUPPORT_TDMA ifdef
adhoc_pick_bss(): remove 'ic' pointer redefinition.
ieee80211_sta.c:
sta_beacon_miss(): remove 'ic' pointer redefinition.
ieee80211_superg.c:
superg_ioctl_set80211(): drop unreachable return.

Tested with clang 3.8.0, gcc 4.6.4 and gcc 5.3.0.

These files were getting sys/malloc.h and vm/uma.h with header pollution
via sys/mbuf.h

The r48589 promised to remove implicit inclusion of if_var.h soon. Prepare
to this event, adding if_var.h to files that do need it. Also, include
all includes that now are included due to implicit pollution via if_var.h

Sponsored by: Netflix
Sponsored by: Nginx, Inc.

Replace the homegrown implementation of nitems() with calls to nitems()
(param.h).

Operating systems that don't have nitems() can easily define it on their own
net80211 OS-specific header file.

Discussed with: adrian

Mesh: management mesh action frames are to be discarded
when not peered.

* Modified ieee80211_recv_action to check if neighbour is peered for
IEEE80211_ACTION_CAT_MESH frames, if not frame is discarded. This is
according to IEEE802.11 2012 standard;
* Removed duplicate checks in each hwmp_recv_* handlers because HWMP
is a subtype of mesh action;

Approved by: adrian (mentor)

Update in ieee80211_action.c for mesh code handlers.

* Removed meshlm_send_action and hwmp_send_action. Introduced one common
for all Mesh Action frames meshaction_send_action. According to 802.11
standard Link Metric and HWMP are all under Mesh Action category;
* Did similar changes to recv_action part;
* The size of meshaction_*_action is set to 12. This is to make room for
the rest of Mesh Action category subtypes;

Approved by: adrian (mentor)

Added Self-protected action category (including MPM).

* Added new action category IEEE80211_ACTION_CAT_SELF_PROT which is used by 11s
for Mesh Peering Management;
* Updated Self protected enum Action codes to start from 1 instead of 0
according to the standard spec;
* Removed old and wrong action categories IEEE80211_ACTION_CAT_MESHPEERING;
* Modified ieee80211_mesh.c and ieee80211_action.c to use the new action
category code;
* Added earlier verification code in ieee80211_input;

Approved by: adrian

* Added IEEE80211_ACTION_CAT_MESH in ieee80211.h as specified amendment spec;
* Moved old categories as specified by D4.0 to be action fields of MESH category
as specified in amendment spec;
* Modified functions to use MESH category and its action fields:
+ ieee80211_send_action_register
+ ieee80211_send_action
+ ieee80211_recv_action_register
+ieee80211_recv_action;
* Modified ieee80211_hwmp_init and hwmp_send_action so they uses correct
action fields as specified in amendment spec;
* Modified ieee80211_parse_action so that it verifies MESH frames.
* Change Mesh Link Metric to use one information element as amendment spec.
Draft 4.0 defined two different information elements for request and response.

Submitted by: monthadar@gmail.com

Fix off by one in ieee80211_send_action_register

Found by: phk's FlexeLint in September
Reviewed by: rpaulo@
MFC after: 1 month

Revert previous commit and add myself to the list of people who should
know better than to commit with a cat in the area.

Add necessary include.

Implementation of the upcoming Wireless Mesh standard, 802.11s, on the
net80211 wireless stack. This work is based on the March 2009 D3.0 draft
standard. This standard is expected to become final next year.
This includes two main net80211 modules, ieee80211_mesh.c
which deals with peer link management, link metric calculation,
routing table control and mesh configuration and ieee80211_hwmp.c
which deals with the actually routing process on the mesh network.
HWMP is the mandatory routing protocol on by the mesh standard, but
others, such as RA-OLSR, can be implemented.

Authentication and encryption are not implemented.

There are several scripts under tools/tools/net80211/scripts that can be
used to test different mesh network topologies and they also teach you
how to setup a mesh vap (for the impatient: ifconfig wlan0 create
wlandev ... wlanmode mesh).

A new build option is available: IEEE80211_SUPPORT_MESH and it's enabled
by default on GENERIC kernels for i386, amd64, sparc64 and pc98.

Drivers that support mesh networks right now are: ath, ral and mwl.

More information at: http://wiki.freebsd.org/WifiMesh

Please note that this work is experimental. Also, please note that
bridging a mesh vap with another network interface is not yet supported.

Many thanks to the FreeBSD Foundation for sponsoring this project and to
Sam Leffler for his support.
Also, I would like to thank Gateworks Corporation for sending me a
Cambria board which was used during the development of this project.

Reviewed by: sam
Approved by: re (kensmith)
Obtained from: projects/mesh11s

Revamp 802.11 action frame handling:
o add a new facility for components to register send+recv handlers
o ieee80211_send_action and ieee80211_recv_action now use the registered
handlers to dispatch operations
o rev ieee80211_send_action api to enable passing arbitrary data
o rev ieee80211_recv_action api to pass the 802.11 frame header as it may
be difficult to locate
o update existing IEEE80211_ACTION_CAT_BA and IEEE80211_ACTION_CAT_HT handling
o update mwl for api rev

Reviewed by: rpaulo
Approved by: re (kensmith)