Implement support for iwm(4) firmware's missed beacon notification.

Requested by deraadt@
ok mpi@

diff --git a/sys/dev/pci/if_iwm.c b/sys/dev/pci/if_iwm.c
index 18d5c13..5f79097 100644 (file)
--- a/sys/dev/pci/if_iwm.c
+++ b/sys/dev/pci/if_iwm.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if_iwm.c,v 1.184 2017/05/28 11:03:48 stsp Exp $       */
+/*     $OpenBSD: if_iwm.c,v 1.185 2017/05/31 08:14:52 stsp Exp $       */
 
 /*
  * Copyright (c) 2014, 2016 genua gmbh <info@genua.de>
@@ -3535,6 +3535,34 @@ iwm_rx_tx_cmd(struct iwm_softc *sc, struct iwm_rx_packet *pkt,
        }
 }
 
+void
+iwm_rx_bmiss(struct iwm_softc *sc, struct iwm_rx_packet *pkt,
+    struct iwm_rx_data *data)
+{
+       struct ieee80211com *ic = &sc->sc_ic;
+       int bmiss_threshold = ic->ic_bmisstimeout / ic->ic_lintval;
+       struct iwm_missed_beacons_notif *mbn = (void *)pkt->data;
+
+       if ((ic->ic_opmode != IEEE80211_M_STA) ||
+           (ic->ic_state != IEEE80211_S_RUN))
+               return;
+
+       bus_dmamap_sync(sc->sc_dmat, data->map, sizeof(*pkt),
+           sizeof(*mbn), BUS_DMASYNC_POSTREAD);
+
+       if (mbn->consec_missed_beacons_since_last_rx > bmiss_threshold) {
+               /*
+                * Rather than go directly to scan state, try to send a
+                * directed probe request first. If that fails then the
+                * state machine will drop us into scanning after timing
+                * out waiting for a probe response.
+                */
+               IEEE80211_SEND_MGMT(ic, ic->ic_bss,
+                   IEEE80211_FC0_SUBTYPE_PROBE_REQ, 0);
+       }
+
+}
+
 int
 iwm_binding_cmd(struct iwm_softc *sc, struct iwm_node *in, uint32_t action)
 {
@@ -6566,7 +6594,7 @@ iwm_notif_intr(struct iwm_softc *sc)
                        break;
 
                case IWM_MISSED_BEACONS_NOTIFICATION:
-                       /* OpenBSD does not provide ieee80211_beacon_miss() */
+                       iwm_rx_bmiss(sc, pkt, data);
                        break;
 
                case IWM_MFUART_LOAD_NOTIFICATION: