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, 30 deletions

diff --git a/sys/dev/ath/if_ath_rx.c b/sys/dev/ath/if_ath_rx.c
index 2779b7a..600d0a5 100644
--- a/sys/dev/ath/if_ath_rx.c
+++ b/sys/dev/ath/if_ath_rx.c
@@ -154,8 +154,7 @@ __FBSDID("$FreeBSD$");
 u_int32_t
 ath_calcrxfilter(struct ath_softc *sc)
 {
-	struct ifnet *ifp = sc->sc_ifp;
-	struct ieee80211com *ic = ifp->if_l2com;
+	struct ieee80211com *ic = &sc->sc_ic;
 	u_int32_t rfilt;
 
 	rfilt = HAL_RX_FILTER_UCAST | HAL_RX_FILTER_BCAST | HAL_RX_FILTER_MCAST;
@@ -164,7 +163,7 @@ ath_calcrxfilter(struct ath_softc *sc)
 	if (ic->ic_opmode != IEEE80211_M_STA)
 		rfilt |= HAL_RX_FILTER_PROBEREQ;
 	/* XXX ic->ic_monvaps != 0? */
-	if (ic->ic_opmode == IEEE80211_M_MONITOR || (ifp->if_flags & IFF_PROMISC))
+	if (ic->ic_opmode == IEEE80211_M_MONITOR || ic->ic_promisc > 0)
 		rfilt |= HAL_RX_FILTER_PROM;
 
 	/*
@@ -330,7 +329,7 @@ ath_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m,
 	int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf)
 {
 	struct ieee80211vap *vap = ni->ni_vap;
-	struct ath_softc *sc = vap->iv_ic->ic_ifp->if_softc;
+	struct ath_softc *sc = vap->iv_ic->ic_softc;
 	uint64_t tsf_beacon_old, tsf_beacon;
 	uint64_t nexttbtt;
 	int64_t tsf_delta;
@@ -463,10 +462,9 @@ ath_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m,
 
 #ifdef	ATH_ENABLE_RADIOTAP_VENDOR_EXT
 static void
-ath_rx_tap_vendor(struct ifnet *ifp, struct mbuf *m,
+ath_rx_tap_vendor(struct ath_softc *sc, struct mbuf *m,
     const struct ath_rx_status *rs, u_int64_t tsf, int16_t nf)
 {
-	struct ath_softc *sc = ifp->if_softc;
 
 	/* Fill in the extension bitmap */
 	sc->sc_rx_th.wr_ext_bitmap = htole32(1 << ATH_RADIOTAP_VENDOR_HEADER);
@@ -529,14 +527,13 @@ ath_rx_tap_vendor(struct ifnet *ifp, struct mbuf *m,
 #endif	/* ATH_ENABLE_RADIOTAP_VENDOR_EXT */
 
 static void
-ath_rx_tap(struct ifnet *ifp, struct mbuf *m,
+ath_rx_tap(struct ath_softc *sc, struct mbuf *m,
 	const struct ath_rx_status *rs, u_int64_t tsf, int16_t nf)
 {
 #define	CHAN_HT20	htole32(IEEE80211_CHAN_HT20)
 #define	CHAN_HT40U	htole32(IEEE80211_CHAN_HT40U)
 #define	CHAN_HT40D	htole32(IEEE80211_CHAN_HT40D)
 #define	CHAN_HT		(CHAN_HT20|CHAN_HT40U|CHAN_HT40D)
-	struct ath_softc *sc = ifp->if_softc;
 	const HAL_RATE_TABLE *rt;
 	uint8_t rix;
 
@@ -560,7 +557,7 @@ ath_rx_tap(struct ifnet *ifp, struct mbuf *m,
 		else if (IEEE80211_IS_CHAN_HT20(sc->sc_curchan))
 			sc->sc_rx_th.wr_chan_flags |= CHAN_HT20;
 	} else if (sc->sc_rx_th.wr_rate & IEEE80211_RATE_MCS) {	/* HT rate */
-		struct ieee80211com *ic = ifp->if_l2com;
+		struct ieee80211com *ic = &sc->sc_ic;
 
 		if ((rs->rs_flags & HAL_RX_2040) == 0)
 			sc->sc_rx_th.wr_chan_flags |= CHAN_HT20;
@@ -617,8 +614,7 @@ ath_rx_pkt(struct ath_softc *sc, struct ath_rx_status *rs, HAL_STATUS status,
 {
 	uint64_t rstamp;
 	int len, type;
-	struct ifnet *ifp = sc->sc_ifp;
-	struct ieee80211com *ic = ifp->if_l2com;
+	struct ieee80211com *ic = &sc->sc_ic;
 	struct ieee80211_node *ni;
 	int is_good = 0;
 	struct ath_rx_edma *re = &sc->sc_rxedma[qtype];
@@ -704,7 +700,7 @@ ath_rx_pkt(struct ath_softc *sc, struct ath_rx_status *rs, HAL_STATUS status,
 					rs->rs_keyix-32 : rs->rs_keyix);
 			}
 		}
-		if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
+		counter_u64_add(ic->ic_ierrors, 1);
 rx_error:
 		/*
 		 * Cleanup any pending partial frame.
@@ -724,9 +720,9 @@ rx_error:
 			/* NB: bpf needs the mbuf length setup */
 			len = rs->rs_datalen;
 			m->m_pkthdr.len = m->m_len = len;
-			ath_rx_tap(ifp, m, rs, rstamp, nf);
+			ath_rx_tap(sc, m, rs, rstamp, nf);
 #ifdef	ATH_ENABLE_RADIOTAP_VENDOR_EXT
-			ath_rx_tap_vendor(ifp, m, rs, rstamp, nf);
+			ath_rx_tap_vendor(sc, m, rs, rstamp, nf);
 #endif	/* ATH_ENABLE_RADIOTAP_VENDOR_EXT */
 			ieee80211_radiotap_rx_all(ic, m);
 		}
@@ -749,7 +745,6 @@ rx_accept:
 			sc->sc_stats.ast_rx_toobig++;
 			m_freem(re->m_rxpending);
 		}
-		m->m_pkthdr.rcvif = ifp;
 		m->m_pkthdr.len = len;
 		re->m_rxpending = m;
 		m = NULL;
@@ -766,10 +761,8 @@ rx_accept:
 		re->m_rxpending = NULL;
 	} else {
 		/*
-		 * Normal single-descriptor receive; setup
-		 * the rcvif and packet length.
+		 * Normal single-descriptor receive; setup packet length.
 		 */
-		m->m_pkthdr.rcvif = ifp;
 		m->m_pkthdr.len = len;
 	}
 
@@ -830,7 +823,6 @@ rx_accept:
 			rs->rs_antenna |= 0x4;
 	}
 
-	if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
 	sc->sc_stats.ast_ant_rx[rs->rs_antenna]++;
 
 	/*
@@ -841,9 +833,9 @@ rx_accept:
 	 * noise setting is filled in above.
 	 */
 	if (ieee80211_radiotap_active(ic)) {
-		ath_rx_tap(ifp, m, rs, rstamp, nf);
+		ath_rx_tap(sc, m, rs, rstamp, nf);
 #ifdef	ATH_ENABLE_RADIOTAP_VENDOR_EXT
-		ath_rx_tap_vendor(ifp, m, rs, rstamp, nf);
+		ath_rx_tap_vendor(sc, m, rs, rstamp, nf);
 #endif	/* ATH_ENABLE_RADIOTAP_VENDOR_EXT */
 	}
 
@@ -991,10 +983,9 @@ ath_rx_proc(struct ath_softc *sc, int resched)
 	((struct ath_desc *)((caddr_t)(_sc)->sc_rxdma.dd_desc + \
 		((_pa) - (_sc)->sc_rxdma.dd_desc_paddr)))
 	struct ath_buf *bf;
-	struct ifnet *ifp = sc->sc_ifp;
 	struct ath_hal *ah = sc->sc_ah;
 #ifdef IEEE80211_SUPPORT_SUPERG
-	struct ieee80211com *ic = ifp->if_l2com;
+	struct ieee80211com *ic = &sc->sc_ic;
 #endif
 	struct ath_desc *ds;
 	struct ath_rx_status *rs;
@@ -1189,15 +1180,10 @@ rx_proc_next:
 		ATH_PCU_UNLOCK(sc);
 	}
 
-	/* XXX check this inside of IF_LOCK? */
-	if (resched && (ifp->if_drv_flags & IFF_DRV_OACTIVE) == 0) {
 #ifdef IEEE80211_SUPPORT_SUPERG
+	if (resched)
 		ieee80211_ff_age_all(ic, 100);
 #endif
-		if (!IFQ_IS_EMPTY(&ifp->if_snd))
-			ath_tx_kick(sc);
-	}
-#undef PA2DESC
 
 	/*
 	 * Put the hardware to sleep again if we're done with it.
@@ -1219,7 +1205,7 @@ rx_proc_next:
 	sc->sc_rxproc_cnt--;
 	ATH_PCU_UNLOCK(sc);
 }
-
+#undef	PA2DESC
 #undef	ATH_RX_MAX
 
 /*