From cf4f71f1e55330e3a34a9dc11f08f489bc9809f3 Mon Sep 17 00:00:00 2001
From: Adrian Chadd <adrian@FreeBSD.org>
Date: Wed, 21 Sep 2016 20:56:10 +0000
Subject: [PATCH] [iwm] use rate control info from the node txrates; use
 mgmtrate for EAPOL frames

This changes the transmit rate control code to do a few things:

* use fixed rates (mcast, ucast, mgmt) where required.
* Don't use a hard-coded 11a or 11bg rate for non-data frames -
  use what net80211 says we should use.
* use mgmtrate for EAPOL frames.

Reviewed by:	avos
Differential Revision:	https://reviews.freebsd.org/D7994
---
 sys/dev/iwm/if_iwm.c | 58 ++++++++++++++++++--------------------------
 1 file changed, 24 insertions(+), 34 deletions(-)

diff --git a/sys/dev/iwm/if_iwm.c b/sys/dev/iwm/if_iwm.c
index 3768af9989b4..f65de23b9c98 100644
--- a/sys/dev/iwm/if_iwm.c
+++ b/sys/dev/iwm/if_iwm.c
@@ -324,7 +324,7 @@ static void	iwm_update_sched(struct iwm_softc *, int, int, uint8_t,
 #endif
 static const struct iwm_rate *
 	iwm_tx_fill_cmd(struct iwm_softc *, struct iwm_node *,
-			struct ieee80211_frame *, struct iwm_tx_cmd *);
+			struct mbuf *, struct iwm_tx_cmd *);
 static int	iwm_tx(struct iwm_softc *, struct mbuf *,
                        struct ieee80211_node *, int);
 static int	iwm_raw_xmit(struct ieee80211_node *, struct mbuf *,
@@ -3197,24 +3197,36 @@ iwm_tx_rateidx_lookup(struct iwm_softc *sc, struct iwm_node *in,
  */
 static const struct iwm_rate *
 iwm_tx_fill_cmd(struct iwm_softc *sc, struct iwm_node *in,
-	struct ieee80211_frame *wh, struct iwm_tx_cmd *tx)
+	struct mbuf *m, struct iwm_tx_cmd *tx)
 {
-	struct ieee80211com *ic = &sc->sc_ic;
 	struct ieee80211_node *ni = &in->in_ni;
+	struct ieee80211_frame *wh;
+	const struct ieee80211_txparam *tp = ni->ni_txparms;
 	const struct iwm_rate *rinfo;
-	int type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
-	int ridx, rate_flags;
+	int type;
+	int ridx, rate_flags, i;
+
+	wh = mtod(m, struct ieee80211_frame *);
+	type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
 
 	tx->rts_retry_limit = IWM_RTS_DFAULT_RETRY_LIMIT;
 	tx->data_retry_limit = IWM_DEFAULT_TX_RETRY;
 
-	/*
-	 * XXX TODO: everything about the rate selection here is terrible!
-	 */
-
-	if (type == IEEE80211_FC0_TYPE_DATA) {
-		int i;
+	if (type == IEEE80211_FC0_TYPE_MGT) {
+		i = iwm_tx_rateidx_lookup(sc, in, tp->mgmtrate);
+		ridx = in->in_ridx[i];
+	} else if (IEEE80211_IS_MULTICAST(wh->i_addr1)) {
+		i = iwm_tx_rateidx_lookup(sc, in, tp->mcastrate);
+		ridx = in->in_ridx[i];
+	} else if (tp->ucastrate != IEEE80211_FIXED_RATE_NONE) {
+		i = iwm_tx_rateidx_lookup(sc, in, tp->ucastrate);
+		ridx = in->in_ridx[i];
+	} else if (m->m_flags & M_EAPOL) {
+		i = iwm_tx_rateidx_lookup(sc, in, tp->mgmtrate);
+		ridx = in->in_ridx[i];
+	} else {
 		/* for data frames, use RS table */
+		/* XXX pass pktlen */
 		(void) ieee80211_ratectl_rate(ni, NULL, 0);
 		i = iwm_tx_rateidx_lookup(sc, in, ni->ni_txrate);
 		ridx = in->in_ridx[i];
@@ -3225,28 +3237,6 @@ iwm_tx_fill_cmd(struct iwm_softc *sc, struct iwm_node *in,
 		IWM_DPRINTF(sc, IWM_DEBUG_XMIT | IWM_DEBUG_TXRATE,
 		    "%s: start with i=%d, txrate %d\n",
 		    __func__, i, iwm_rates[ridx].rate);
-	} else {
-		/*
-		 * For non-data, use the lowest supported rate for the given
-		 * operational mode.
-		 *
-		 * Note: there may not be any rate control information available.
-		 * This driver currently assumes if we're transmitting data
-		 * frames, use the rate control table.  Grr.
-		 *
-		 * XXX TODO: use the configured rate for the traffic type!
-		 * XXX TODO: this should be per-vap, not curmode; as we later
-		 * on we'll want to handle off-channel stuff (eg TDLS).
-		 */
-		if (ic->ic_curmode == IEEE80211_MODE_11A) {
-			/*
-			 * XXX this assumes the mode is either 11a or not 11a;
-			 * definitely won't work for 11n.
-			 */
-			ridx = IWM_RIDX_OFDM;
-		} else {
-			ridx = IWM_RIDX_CCK;
-		}
 	}
 
 	rinfo = &iwm_rates[ridx];
@@ -3308,7 +3298,7 @@ iwm_tx(struct iwm_softc *sc, struct mbuf *m, struct ieee80211_node *ni, int ac)
 	tx = (void *)cmd->data;
 	memset(tx, 0, sizeof(*tx));
 
-	rinfo = iwm_tx_fill_cmd(sc, in, wh, tx);
+	rinfo = iwm_tx_fill_cmd(sc, in, m, tx);
 
 	/* Encrypt the frame if need be. */
 	if (wh->i_fc[1] & IEEE80211_FC1_PROTECTED) {