Change KPI of how device drivers that provide wireless connectivity interact

with the net80211 stack.

Historical background: originally wireless devices created an interface,
just like Ethernet devices do. Name of an interface matched the name of
the driver that created. Later, wlan(4) layer was introduced, and the
wlanX interfaces become the actual interface, leaving original ones as
"a parent interface" of wlanX. Kernelwise, the KPI between net80211 layer
and a driver became a mix of methods that pass a pointer to struct ifnet
as identifier and methods that pass pointer to struct ieee80211com. From
user point of view, the parent interface just hangs on in the ifconfig
list, and user can't do anything useful with it.

Now, the struct ifnet goes away. The struct ieee80211com is the only
KPI between a device driver and net80211. Details:

- The struct ieee80211com is embedded into drivers softc.
- Packets are sent via new ic_transmit method, which is very much like
  the previous if_transmit.
- Bringing parent up/down is done via new ic_parent method, which notifies
  driver about any changes: number of wlan(4) interfaces, number of them
  in promisc or allmulti state.
- Device specific ioctls (if any) are received on new ic_ioctl method.
- Packets/errors accounting are done by the stack. In certain cases, when
  driver experiences errors and can not attribute them to any specific
  interface, driver updates ic_oerrors or ic_ierrors counters.

Details on interface configuration with new world order:
- A sequence of commands needed to bring up wireless DOESN"T change.
- /etc/rc.conf parameters DON'T change.
- List of devices that can be used to create wlan(4) interfaces is
  now provided by net.wlan.devices sysctl.

Most drivers in this change were converted by me, except of wpi(4),
that was done by Andriy Voskoboinyk. Big thanks to Kevin Lo for testing
changes to at least 8 drivers. Thanks to Olivier Cochard, gjb@, mmoll@,
op@ and lev@, who also participated in testing. Details here:

https://wiki.freebsd.org/projects/ifnet/net80211

Still, drivers: ndis, wtap, mwl, ipw, bwn, wi, upgt, uath were not
tested. Changes to mwl, ipw, bwn, wi, upgt are trivial and chances
of problems are low. The wtap wasn't compilable even before this change.
But the ndis driver is complex, and it is likely to be broken with this
commit. Help with testing and debugging it is appreciated.

Differential Revision:	D2655, D2740
Sponsored by:	Nginx, Inc.
Sponsored by:	Netflix

2 files changed, 79 insertions, 0 deletions

diff --git a/etc/network.subr b/etc/network.subr
index 73ed575..5087a93 100644
--- a/etc/network.subr
+++ b/etc/network.subr
@@ -1249,6 +1249,70 @@ ifscript_down()
 	fi
 }
 
+# wlan_up
+#	Create IEEE802.3 interfaces.
+#
+wlan_up()
+{
+	local _list _iflist wlan parent ifn
+	_list=
+	_iflist=$*
+
+	for wlan in `set | egrep ^wlans_[a-z]+[0-9]+=[a-z]+[0-9]+`; do
+		# Parse wlans_$parent=$ifn
+		wlan=`echo $wlan | sed -E 's/wlans_([a-z]+[0-9]+)=([a-z]+[0-9]+)/\1:\2/'`
+		OIFS=$IFS; IFS=:; set -- $wlan; parent=$1; ifn=$2; IFS=$OIFS
+		case $_iflist in
+		""|$ifn|$ifn\ *|*\ $ifn\ *|*\ $ifn)	;;
+		*)	continue ;;
+		esac
+		# Skip if ${ifn} already exists.
+		if ${IFCONFIG_CMD} $ifn > /dev/null 2>&1; then
+			continue
+		fi
+		${IFCONFIG_CMD} ${ifn} create wlandev ${parent}
+		if [ $? -eq 0 ]; then
+			_list="$_list $ifn"
+		fi
+	done
+	if [ -n "${_list# }" ]; then
+		echo "Created wlan(4) interfaces: ${_list# }."
+	fi
+	debug "Created wlan(4)s: ${_list# }"
+}
+
+# wlan_down
+#	Destroy IEEE802.3 interfaces.
+#
+wlan_down()
+{
+	local _list _iflist wlan parent ifn
+	_list=
+	_iflist=$*
+
+	for wlan in `set | egrep ^wlans_[a-z]+[0-9]+=[a-z]+[0-9]+`; do
+		# Parse wlans_$parent=$ifn
+		wlan=`echo $wlan | sed -E 's/wlans_([a-z]+[0-9]+)=([a-z]+[0-9]+)/\1:\2/'`
+		OIFS=$IFS; IFS=:; set -- $wlan; parent=$1; ifn=$2; IFS=$OIFS
+		case $_iflist in
+		""|$ifn|$ifn\ *|*\ $ifn\ *|*\ $ifn)	;;
+		*)	continue ;;
+		esac
+		# Skip if ${ifn} doesn't exists.
+		if ! ${IFCONFIG_CMD} $ifn > /dev/null 2>&1; then
+			continue
+		fi
+		${IFCONFIG_CMD} -n ${ifn} destroy
+		if [ $? -eq 0 ]; then
+			_list="$_list $ifn"
+		fi
+	done
+	if [ -n "${_list# }" ]; then
+		echo "Destroyed wlan(4) interfaces: ${_list# }."
+	fi
+	debug "Destroyed wlan(4)s: ${_list# }"
+}
+
 # clone_up
 #	Create cloneable interfaces.
 #
@@ -1398,6 +1462,9 @@ clone_down()
 #	Create and configure child interfaces.  Return 0 if child
 #	interfaces are created.
 #
+#	XXXGL: the wlan code in this functions is superseded by wlan_up(),
+#	and will go away soon.
+#
 childif_create()
 {
 	local cfg child child_vlans child_wlans create_args debug_flags ifn i
diff --git a/etc/rc.d/netif b/etc/rc.d/netif
index 0915b28..c7b84b9 100755
--- a/etc/rc.d/netif
+++ b/etc/rc.d/netif
@@ -37,6 +37,8 @@ name="netif"
 rcvar="${name}_enable"
 start_cmd="netif_start"
 stop_cmd="netif_stop"
+wlanup_cmd="wlan_up"
+wlandown_cmd="wlan_down"
 cloneup_cmd="clone_up"
 clonedown_cmd="clone_down"
 clear_cmd="doclear"
@@ -65,6 +67,9 @@ netif_start()
 		trap : 2
 	fi
 
+	# Create IEEE802.3 interface
+	wlan_up $cmdifn
+
 	# Create cloned interfaces
 	clone_up $cmdifn
 
@@ -91,12 +96,14 @@ netif_start()
 netif_stop()
 {
 	_clone_down=1
+	_wlan_down=1
 	netif_stop0 $*
 }
 
 doclear()
 {
 	_clone_down=
+	_wlan_down=
 	netif_stop0 $*
 }
 
@@ -111,6 +118,11 @@ netif_stop0()
 	# Deconfigure the interface(s)
 	netif_common ifn_stop $cmdifn
 
+	# Destroy wlan interfaces
+	if [ -n "$_wlan_down" ]; then
+		wlan_down $cmdifn
+	fi
+
 	# Destroy cloned interfaces
 	if [ -n "$_clone_down" ]; then
 		clone_down $cmdifn