Finish support for receiving 11n A-MPDUs.

The initial implementation was added by damien@ years ago.
Summary of the changes made in this commit:
 - In ieee80211_input(), process A-MPDUs before duplicate detection.
 - Don't forget to set ba->ba_ni in ieee80211_recv_addba_req()
   so we don't crash in ieee80211_rx_ba_timeout().
 - In ieee80211_recv_addba_req(), tweak the logic to deny BlockAck
   requests if the driver has no callback for doing so.
 - Implement ieee80211_ba_del() which cleans up BlockAck state.
 - Increase the minimum and maximum lifetime for BlockAck agrements.

ok mpi@

3 files changed, 79 insertions, 27 deletions

diff --git a/sys/net80211/ieee80211_input.c b/sys/net80211/ieee80211_input.c
index 2da9eeefc9e..c1b05365d6b 100644
--- a/sys/net80211/ieee80211_input.c
+++ b/sys/net80211/ieee80211_input.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ieee80211_input.c,v 1.142 2015/11/15 11:14:17 stsp Exp $	*/
+/*	$OpenBSD: ieee80211_input.c,v 1.143 2015/12/12 11:25:46 stsp Exp $	*/
 
 /*-
  * Copyright (c) 2001 Atsushi Onoe
@@ -280,6 +280,43 @@ ieee80211_input(struct ifnet *ifp, struct mbuf *m, struct ieee80211_node *ni,
 		tid = 0;
 	}
 
+#ifndef IEEE80211_NO_HT
+	if (type == IEEE80211_FC0_TYPE_DATA && hasqos &&
+	    !(rxi->rxi_flags & IEEE80211_RXI_AMPDU_DONE)) {
+		int ba_state = ni->ni_rx_ba[tid].ba_state;
+
+		/* 
+		 * If Block Ack was explicitly requested, check
+		 * if we have a BA agreement for this RA/TID.
+		 */
+		if ((qos & IEEE80211_QOS_ACK_POLICY_MASK) ==
+		    IEEE80211_QOS_ACK_POLICY_BA &&
+		    ba_state != IEEE80211_BA_AGREED) {
+			DPRINTF(("no BA agreement for %s, TID %d\n",
+			    ether_sprintf(ni->ni_macaddr), tid));
+			/* send a DELBA with reason code UNKNOWN-BA */
+			IEEE80211_SEND_ACTION(ic, ni,
+			    IEEE80211_CATEG_BA, IEEE80211_ACTION_DELBA,
+			    IEEE80211_REASON_SETUP_REQUIRED << 16 | tid);
+			goto err;
+		}
+
+		/* 
+		 * Check if we have an explicit or implicit
+		 * Block Ack Request for a valid BA agreement.
+		 */
+		if (ba_state == IEEE80211_BA_AGREED &&
+		    ((qos & IEEE80211_QOS_ACK_POLICY_MASK) ==
+		    IEEE80211_QOS_ACK_POLICY_BA ||
+		    (qos & IEEE80211_QOS_ACK_POLICY_MASK) ==
+		    IEEE80211_QOS_ACK_POLICY_NORMAL)) {
+			/* go through A-MPDU reordering */
+			ieee80211_input_ba(ifp, m, ni, tid, rxi);
+			return;	/* don't free m! */
+		}
+	}
+#endif
+
 	/* duplicate detection (see 9.2.9) */
 	if (ieee80211_has_seq(wh) &&
 	    ic->ic_state != IEEE80211_S_SCAN) {
@@ -430,27 +467,6 @@ ieee80211_input(struct ifnet *ifp, struct mbuf *m, struct ieee80211_node *ni,
 			goto out;
 		}
 
-#ifndef IEEE80211_NO_HT
-		if (!(rxi->rxi_flags & IEEE80211_RXI_AMPDU_DONE) &&
-		    hasqos && (qos & IEEE80211_QOS_ACK_POLICY_MASK) ==
-		    IEEE80211_QOS_ACK_POLICY_BA) {
-			/* check if we have a BA agreement for this RA/TID */
-			if (ni->ni_rx_ba[tid].ba_state !=
-			    IEEE80211_BA_AGREED) {
-				DPRINTF(("no BA agreement for %s, TID %d\n",
-				    ether_sprintf(ni->ni_macaddr), tid));
-				/* send a DELBA with reason code UNKNOWN-BA */
-				IEEE80211_SEND_ACTION(ic, ni,
-				    IEEE80211_CATEG_BA, IEEE80211_ACTION_DELBA,
-				    IEEE80211_REASON_SETUP_REQUIRED << 16 |
-				    tid);
-				goto err;
-			}
-			/* go through A-MPDU reordering */
-			ieee80211_input_ba(ifp, m, ni, tid, rxi);
-			return;	/* don't free m! */
-		}
-#endif
 		if ((ic->ic_flags & IEEE80211_F_WEPON) ||
 		    ((ic->ic_flags & IEEE80211_F_RSNON) &&
 		     (ni->ni_flags & IEEE80211_NODE_RXPROT))) {
@@ -2449,6 +2465,7 @@ ieee80211_recv_addba_req(struct ieee80211com *ic, struct mbuf *m,
 		ba->ba_timeout_val = IEEE80211_BA_MIN_TIMEOUT;
 	else if (ba->ba_timeout_val > IEEE80211_BA_MAX_TIMEOUT)
 		ba->ba_timeout_val = IEEE80211_BA_MAX_TIMEOUT;
+	ba->ba_ni = ni;
 	timeout_set(&ba->ba_to, ieee80211_rx_ba_timeout, ba);
 	ba->ba_winsize = bufsz;
 	if (ba->ba_winsize == 0 || ba->ba_winsize > IEEE80211_BA_MAX_WINSZ)
@@ -2465,7 +2482,7 @@ ieee80211_recv_addba_req(struct ieee80211com *ic, struct mbuf *m,
 	ba->ba_head = 0;
 
 	/* notify drivers of this new Block Ack agreement */
-	if (ic->ic_ampdu_rx_start != NULL &&
+	if (ic->ic_ampdu_rx_start == NULL ||
 	    ic->ic_ampdu_rx_start(ic, ni, tid) != 0) {
 		/* driver failed to setup, rollback */
 		free(ba->ba_buf, M_DEVBUF, 0);
diff --git a/sys/net80211/ieee80211_node.c b/sys/net80211/ieee80211_node.c
index aa6d5c97a7b..ebe90d16374 100644
--- a/sys/net80211/ieee80211_node.c
+++ b/sys/net80211/ieee80211_node.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ieee80211_node.c,v 1.92 2015/11/24 13:45:06 mpi Exp $	*/
+/*	$OpenBSD: ieee80211_node.c,v 1.93 2015/12/12 11:25:46 stsp Exp $	*/
 /*	$NetBSD: ieee80211_node.c,v 1.14 2004/05/09 09:18:47 dyoung Exp $	*/
 
 /*-
@@ -68,6 +68,9 @@ u_int8_t ieee80211_node_getrssi(struct ieee80211com *,
 void ieee80211_setup_node(struct ieee80211com *, struct ieee80211_node *,
     const u_int8_t *);
 void ieee80211_free_node(struct ieee80211com *, struct ieee80211_node *);
+#ifndef IEEE80211_NO_HT
+void ieee80211_ba_del(struct ieee80211_node *);
+#endif
 struct ieee80211_node *ieee80211_alloc_node_helper(struct ieee80211com *);
 void ieee80211_node_cleanup(struct ieee80211com *, struct ieee80211_node *);
 void ieee80211_needs_auth(struct ieee80211com *, struct ieee80211_node *);
@@ -757,6 +760,9 @@ ieee80211_node_cleanup(struct ieee80211com *ic, struct ieee80211_node *ni)
 		free(ni->ni_rsnie, M_DEVBUF, 0);
 		ni->ni_rsnie = NULL;
 	}
+#ifndef IEEE80211_NO_HT
+	ieee80211_ba_del(ni);
+#endif
 }
 
 void
@@ -1065,6 +1071,32 @@ ieee80211_find_node_for_beacon(struct ieee80211com *ic,
 	return (keep);
 }
 
+#ifndef IEEE80211_NO_HT
+void
+ieee80211_ba_del(struct ieee80211_node *ni)
+{
+	int tid;
+
+	for (tid = 0; tid < nitems(ni->ni_rx_ba); tid++) {
+		struct ieee80211_rx_ba *ba = &ni->ni_rx_ba[tid];
+		if (ba->ba_state == IEEE80211_BA_AGREED) {
+			if (timeout_pending(&ba->ba_to))
+				timeout_del(&ba->ba_to);
+			ba->ba_state = IEEE80211_BA_INIT;
+		}
+	}
+
+	for (tid = 0; tid < nitems(ni->ni_tx_ba); tid++) {
+		struct ieee80211_tx_ba *ba = &ni->ni_tx_ba[tid];
+		if (ba->ba_state == IEEE80211_BA_AGREED) {
+			if (timeout_pending(&ba->ba_to))
+				timeout_del(&ba->ba_to);
+			ba->ba_state = IEEE80211_BA_INIT;
+		}
+	}
+}
+#endif
+
 void
 ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni)
 {
@@ -1079,6 +1111,9 @@ ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni)
 	timeout_del(&ni->ni_sa_query_to);
 	IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap);
 #endif
+#ifndef IEEE80211_NO_HT
+	ieee80211_ba_del(ni);
+#endif
 	RB_REMOVE(ieee80211_tree, &ic->ic_tree, ni);
 	ic->ic_nnodes--;
 #ifndef IEEE80211_STA_ONLY
diff --git a/sys/net80211/ieee80211_node.h b/sys/net80211/ieee80211_node.h
index 59f17633cc4..12341b6c4ea 100644
--- a/sys/net80211/ieee80211_node.h
+++ b/sys/net80211/ieee80211_node.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ieee80211_node.h,v 1.49 2015/11/15 12:34:07 stsp Exp $	*/
+/*	$OpenBSD: ieee80211_node.h,v 1.50 2015/12/12 11:25:46 stsp Exp $	*/
 /*	$NetBSD: ieee80211_node.h,v 1.9 2004/04/30 22:57:32 dyoung Exp $	*/
 
 /*-
@@ -112,8 +112,8 @@ struct ieee80211_tx_ba {
 	struct ieee80211_node	*ba_ni;	/* backpointer for callbacks */
 	struct timeout		ba_to;
 	int			ba_timeout_val;
-#define IEEE80211_BA_MIN_TIMEOUT	(10 * 1000)		/* 10msec */
-#define IEEE80211_BA_MAX_TIMEOUT	(10 * 1000 * 1000)	/* 10sec */
+#define IEEE80211_BA_MIN_TIMEOUT	(10 * 1000 * 1000)	/* 10 sec */
+#define IEEE80211_BA_MAX_TIMEOUT	(60 * 1000 * 1000)	/* 60 sec */
 
 	int			ba_state;
 #define IEEE80211_BA_INIT	0