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

1 files changed, 16 insertions, 55 deletions

diff --git a/sys/net80211/ieee80211_ioctl.c b/sys/net80211/ieee80211_ioctl.c
index 54ab390..1c7ddb9 100644
--- a/sys/net80211/ieee80211_ioctl.c
+++ b/sys/net80211/ieee80211_ioctl.c
@@ -1329,13 +1329,12 @@ static int
 setmlme_dropsta(struct ieee80211vap *vap,
 	const uint8_t mac[IEEE80211_ADDR_LEN], struct mlmeop *mlmeop)
 {
-	struct ieee80211com *ic = vap->iv_ic;
-	struct ieee80211_node_table *nt = &ic->ic_sta;
+	struct ieee80211_node_table *nt = &vap->iv_ic->ic_sta;
 	struct ieee80211_node *ni;
 	int error = 0;
 
 	/* NB: the broadcast address means do 'em all */
-	if (!IEEE80211_ADDR_EQ(mac, ic->ic_ifp->if_broadcastaddr)) {
+	if (!IEEE80211_ADDR_EQ(mac, vap->iv_ifp->if_broadcastaddr)) {
 		IEEE80211_NODE_LOCK(nt);
 		ni = ieee80211_find_node_locked(nt, mac);
 		IEEE80211_NODE_UNLOCK(nt);
@@ -2529,14 +2528,9 @@ ieee80211_scanreq(struct ieee80211vap *vap, struct ieee80211_scan_req *sr)
 static __noinline int
 ieee80211_ioctl_scanreq(struct ieee80211vap *vap, struct ieee80211req *ireq)
 {
-	struct ieee80211com *ic = vap->iv_ic;
 	struct ieee80211_scan_req sr;		/* XXX off stack? */
 	int error;
 
-	/* NB: parent must be running */
-	if ((ic->ic_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
-		return ENXIO;
-
 	if (ireq->i_len != sizeof(sr))
 		return EINVAL;
 	error = copyin(ireq->i_data, &sr, sizeof(sr));
@@ -3300,41 +3294,6 @@ ieee80211_ioctl_set80211(struct ieee80211vap *vap, u_long cmd, struct ieee80211r
 	return error;
 }
 
-/*
- * Rebuild the parent's multicast address list after an add/del
- * of a multicast address for a vap.  We have no way to tell
- * what happened above to optimize the work so we purge the entire
- * list and rebuild from scratch.  This is way expensive.
- * Note also the half-baked workaround for if_addmulti calling
- * back to the parent device; there's no way to insert mcast
- * entries quietly and/or cheaply.
- */
-static void
-ieee80211_ioctl_updatemulti(struct ieee80211com *ic)
-{
-	struct ifnet *parent = ic->ic_ifp;
-	struct ieee80211vap *vap;
-	void *ioctl;
-
-	IEEE80211_LOCK(ic);
-	if_delallmulti(parent);
-	ioctl = parent->if_ioctl;	/* XXX WAR if_allmulti */
-	parent->if_ioctl = NULL;
-	TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) {
-		struct ifnet *ifp = vap->iv_ifp;
-		struct ifmultiaddr *ifma;
-
-		TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
-			if (ifma->ifma_addr->sa_family != AF_LINK)
-				continue;
-			(void) if_addmulti(parent, ifma->ifma_addr, NULL);
-		}
-	}
-	parent->if_ioctl = ioctl;
-	ieee80211_runtask(ic, &ic->ic_mcast_task);
-	IEEE80211_UNLOCK(ic);
-}
-
 int
 ieee80211_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 {
@@ -3347,8 +3306,11 @@ ieee80211_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 	switch (cmd) {
 	case SIOCSIFFLAGS:
 		IEEE80211_LOCK(ic);
-		ieee80211_syncifflag_locked(ic, IFF_PROMISC);
-		ieee80211_syncifflag_locked(ic, IFF_ALLMULTI);
+		if ((ifp->if_flags ^ vap->iv_ifflags) & IFF_PROMISC)
+			ieee80211_promisc(vap, ifp->if_flags & IFF_PROMISC);
+		if ((ifp->if_flags ^ vap->iv_ifflags) & IFF_ALLMULTI)
+			ieee80211_allmulti(vap, ifp->if_flags & IFF_ALLMULTI);
+		vap->iv_ifflags = ifp->if_flags;
 		if (ifp->if_flags & IFF_UP) {
 			/*
 			 * Bring ourself up unless we're already operational.
@@ -3371,7 +3333,7 @@ ieee80211_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 		break;
 	case SIOCADDMULTI:
 	case SIOCDELMULTI:
-		ieee80211_ioctl_updatemulti(ic);
+		ieee80211_runtask(ic, &ic->ic_mcast_task);
 		break;
 	case SIOCSIFMEDIA:
 	case SIOCGIFMEDIA:
@@ -3427,17 +3389,16 @@ ieee80211_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 			break;
 		}
 		break;
-	/* Pass NDIS ioctls up to the driver */
-	case SIOCGDRVSPEC:
-	case SIOCSDRVSPEC:
-	case SIOCGPRIVATE_0: {
-		struct ifnet *parent = vap->iv_ic->ic_ifp;
-		error = parent->if_ioctl(parent, cmd, data);
-		break;
-	}
 	default:
+		/*
+		 * Pass unknown ioctls first to the driver, and if it
+		 * returns ENOTTY, then to the generic Ethernet handler.
+		 */
+		if (ic->ic_ioctl != NULL &&
+		    (error = ic->ic_ioctl(ic, cmd, data)) != ENOTTY)
+			break;
 		error = ether_ioctl(ifp, cmd, data);
 		break;
 	}
-	return error;
+	return (error);
 }