Manage the HT protection setting if acting as hostap with 11n enabled.

For now we flip-flop only between non-member protection and non-HT protection.
Running a HT network without protection would require monitoring environmental
conditions (e.g. foreign beacons) which make HT protection necessary.

The ic_update_htprot driver function becomes optional because it won't be
needed by all drivers. Only call it if the driver has set a function pointer.

ok tb@

3 files changed, 37 insertions, 5 deletions

diff --git a/sys/net80211/ieee80211_input.c b/sys/net80211/ieee80211_input.c
index f57cdbdbc4c..746f8d8dd21 100644
--- a/sys/net80211/ieee80211_input.c
+++ b/sys/net80211/ieee80211_input.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ieee80211_input.c,v 1.180 2016/09/21 12:21:27 stsp Exp $	*/
+/*	$OpenBSD: ieee80211_input.c,v 1.181 2017/01/09 12:40:00 stsp Exp $	*/
 
 /*-
  * Copyright (c) 2001 Atsushi Onoe
@@ -1612,7 +1612,8 @@ ieee80211_recv_probe_resp(struct ieee80211com *ic, struct mbuf *m,
 				    htprot_last, htprot));
 				ic->ic_stats.is_ht_prot_change++;
 				ic->ic_bss->ni_htop1 = ni->ni_htop1;
-				ic->ic_update_htprot(ic, ic->ic_bss);
+				if (ic->ic_update_htprot)
+					ic->ic_update_htprot(ic, ic->ic_bss);
 			}
 		}
 
diff --git a/sys/net80211/ieee80211_node.c b/sys/net80211/ieee80211_node.c
index f9c2d55c55c..f255e0d1a2a 100644
--- a/sys/net80211/ieee80211_node.c
+++ b/sys/net80211/ieee80211_node.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ieee80211_node.c,v 1.108 2017/01/09 09:31:18 stsp Exp $	*/
+/*	$OpenBSD: ieee80211_node.c,v 1.109 2017/01/09 12:40:00 stsp Exp $	*/
 /*	$NetBSD: ieee80211_node.c,v 1.14 2004/05/09 09:18:47 dyoung Exp $	*/
 
 /*-
@@ -353,6 +353,16 @@ ieee80211_create_ibss(struct ieee80211com* ic, struct ieee80211_channel *chan)
 	ni->ni_capinfo = IEEE80211_CAPINFO_IBSS;
 	if (ic->ic_flags & IEEE80211_F_WEPON)
 		ni->ni_capinfo |= IEEE80211_CAPINFO_PRIVACY;
+	if (ic->ic_flags & IEEE80211_F_HTON) {
+		/* 
+		 * Default to non-member HT protection until we have a way
+		 * of picking up information from the environment (such as
+		 * beacons from other networks) which proves that only HT
+		 * STAs are on the air.
+		 */
+		ni->ni_htop1 = IEEE80211_HTPROT_NONMEMBER;
+		ic->ic_protmode = IEEE80211_PROT_RTSCTS;
+	}
 	if (ic->ic_flags & IEEE80211_F_RSNON) {
 		struct ieee80211_key *k;
 
@@ -1423,7 +1433,15 @@ ieee80211_needs_auth(struct ieee80211com *ic, struct ieee80211_node *ni)
 void
 ieee80211_node_join_ht(struct ieee80211com *ic, struct ieee80211_node *ni)
 {
-	/* TBD */
+	enum ieee80211_htprot;
+
+	/* Update HT protection setting. */
+	if ((ni->ni_flags & IEEE80211_NODE_HT) == 0) {
+		ic->ic_nonhtsta++;
+		ic->ic_bss->ni_htop1 = IEEE80211_HTPROT_NONHT_MIXED;
+		if (ic->ic_update_htprot)
+			ic->ic_update_htprot(ic, ic->ic_bss);
+	}
 }
 
 /*
@@ -1712,6 +1730,16 @@ ieee80211_node_leave(struct ieee80211com *ic, struct ieee80211_node *ni)
 
 	if (ni->ni_flags & IEEE80211_NODE_HT)
 		ieee80211_node_leave_ht(ic, ni);
+	else if (ic->ic_flags & IEEE80211_F_HTON) {
+		if (ic->ic_nonhtsta == 0)
+			panic("bogus non-HT station count %d", ic->ic_nonhtsta);
+		if (--ic->ic_nonhtsta == 0) {
+			/* All associated stations now support HT. */
+			ic->ic_bss->ni_htop1 = IEEE80211_HTPROT_NONMEMBER;
+			if (ic->ic_update_htprot)
+				ic->ic_update_htprot(ic, ic->ic_bss);
+		}
+	}
 
 	if (ic->ic_node_leave != NULL)
 		(*ic->ic_node_leave)(ic, ni);
diff --git a/sys/net80211/ieee80211_var.h b/sys/net80211/ieee80211_var.h
index 08024e7c27c..a43979fd53c 100644
--- a/sys/net80211/ieee80211_var.h
+++ b/sys/net80211/ieee80211_var.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ieee80211_var.h,v 1.73 2016/12/17 18:35:54 stsp Exp $	*/
+/*	$OpenBSD: ieee80211_var.h,v 1.74 2017/01/09 12:40:00 stsp Exp $	*/
 /*	$NetBSD: ieee80211_var.h,v 1.7 2004/05/06 03:07:10 dyoung Exp $	*/
 
 /*-
@@ -310,6 +310,9 @@ struct ieee80211com {
 	u_int			ic_dtim_period;
 	u_int			ic_dtim_count;
 
+#ifndef IEEE80211_STA_ONLY
+	u_int16_t		ic_nonhtsta;	/* # non-HT stations */
+#endif
 	u_int32_t		ic_txbfcaps;
 	u_int16_t		ic_htcaps;
 	u_int8_t		ic_ampdu_params;