wifi: handle short preamble and short time slot capabilities

- drivers enable short preamble and sort timeslot depending
  on the ap beacon capinfo field (bss->cap)
- wifi sets short preamble bit in capinfo on association request
- wifi sets short timeslot bit when ap advertized it in beacon

4 files changed, 26 insertions, 9 deletions

diff --git a/sys/src/9/pc/etheriwl.c b/sys/src/9/pc/etheriwl.c
index 6bb902e2c..105bb44cc 100644
--- a/sys/src/9/pc/etheriwl.c
+++ b/sys/src/9/pc/etheriwl.c
@@ -1845,7 +1845,12 @@ rxon(Ether *edev, Wnode *bss)
 			ctlr->channel = bss->channel;
 		bss = nil;
 	}
+	flags = RFlagTSF | RFlagCTSToSelf | RFlag24Ghz | RFlagAuto;
 	if(bss != nil){
+		if(bss->cap & (1<<5))
+			flags |= RFlagShPreamble;
+		if(bss->cap & (1<<10))
+			flags |= RFlagShSlot;
 		ctlr->channel = bss->channel;
 		memmove(ctlr->bssid, bss->bssid, Eaddrlen);
 		ctlr->aid = bss->aid;
@@ -1861,7 +1866,6 @@ rxon(Ether *edev, Wnode *bss)
 		ctlr->bcastnodeid = -1;
 		ctlr->bssnodeid = -1;
 	}
-	flags = RFlagTSF | RFlagCTSToSelf | RFlag24Ghz | RFlagAuto;
 
 	if(ctlr->aid != 0)
 		setled(ctlr, 2, 0, 1);		/* on when associated */
diff --git a/sys/src/9/pc/etherrt2860.c b/sys/src/9/pc/etherrt2860.c
index 7d71d612f..2311611e8 100644
--- a/sys/src/9/pc/etherrt2860.c
+++ b/sys/src/9/pc/etherrt2860.c
@@ -1318,10 +1318,12 @@ rxon(Ether *edev, Wnode *bss)
 {
 	u32int tmp;
 	Ctlr *ctlr;
+	int cap;
 
 	ctlr = edev->ctlr;
 
 	if(bss != nil){
+		cap = bss->cap;
 		ctlr->channel = bss->channel;
 		memmove(ctlr->bssid, bss->bssid, Eaddrlen);
 		ctlr->aid = bss->aid;
@@ -1332,6 +1334,7 @@ rxon(Ether *edev, Wnode *bss)
 		}else
 			ctlr->bcastnodeid = -1;
 	}else{
+		cap = 0;
 		memmove(ctlr->bssid, edev->bcast, Eaddrlen);
 		ctlr->aid = 0;
 		ctlr->bcastnodeid = -1;
@@ -1377,14 +1380,13 @@ rxon(Ether *edev, Wnode *bss)
 	/* update slot */
 	tmp = csr32r(ctlr, BkoffSlotCfg);
 	tmp &= ~0xff;
-	tmp |= /* (ic->ic_flags & IEEE80211_F_SHSLOT) ? 9 : */ 20;
+	tmp |= (cap & (1<<10)) ? 9 : 20;
 	csr32w(ctlr, BkoffSlotCfg, tmp);
 	
 	/* set TX preamble */
 	tmp = csr32r(ctlr, AutoRspCfg);
 	tmp &= ~CckShortEn;
-/*	if(sc->sc_ic.ic_flags & IEEE80211_F_SHPREAMBLE)
-		tmp |= CckShortEn; */
+	if(cap & (1<<5)) tmp |= CckShortEn;	
 	csr32w(ctlr, AutoRspCfg, tmp);
 
 	/* set basic rates */
diff --git a/sys/src/9/pc/etherwpi.c b/sys/src/9/pc/etherwpi.c
index 4dbc65e6d..1663eb31b 100644
--- a/sys/src/9/pc/etherwpi.c
+++ b/sys/src/9/pc/etherwpi.c
@@ -1304,7 +1304,12 @@ rxon(Ether *edev, Wnode *bss)
 			ctlr->channel = bss->channel;
 		bss = nil;
 	}
+	flags = RFlagTSF | RFlag24Ghz | RFlagAuto;
 	if(bss != nil){
+		if(bss->cap & (1<<5))
+			flags |= RFlagShPreamble;
+		if(bss->cap & (1<<10))
+			flags |= RFlagShSlot;
 		ctlr->channel = bss->channel;
 		memmove(ctlr->bssid, bss->bssid, Eaddrlen);
 		ctlr->aid = bss->aid;
@@ -1319,7 +1324,6 @@ rxon(Ether *edev, Wnode *bss)
 		ctlr->bcastnodeid = -1;
 		ctlr->bssnodeid = -1;
 	}
-	flags = RFlagTSF | RFlag24Ghz | RFlagAuto;
 
 	if(ctlr->aid != 0)
 		setled(ctlr, 2, 0, 1);		/* on when associated */
diff --git a/sys/src/9/pc/wifi.c b/sys/src/9/pc/wifi.c
index 8325c0aa7..7cea422f7 100644
--- a/sys/src/9/pc/wifi.c
+++ b/sys/src/9/pc/wifi.c
@@ -320,7 +320,7 @@ sendassoc(Wifi *wifi, Wnode *bss)
 	Wifipkt *w;
 	Block *b;
 	uchar *p;
-	int n;
+	int cap, n;
 
 	b = allocb(WIFIHDRSIZE + 512);
 	w = (Wifipkt*)b->wp;
@@ -331,9 +331,16 @@ sendassoc(Wifi *wifi, Wnode *bss)
 	memmove(w->a3, bss->bssid, Eaddrlen);
 	b->wp += WIFIHDRSIZE;
 	p = b->wp;
-	*p++ = 1;	/* capinfo */
-	*p++ = 0;
-	*p++ = 16;	/* interval */
+
+	/* capinfo */
+	cap = 1;				// ESS
+	cap |= (1<<5);				// Short Preamble
+	cap |= (1<<10) & bss->cap;		// Short Slot Time
+	*p++ = cap;
+	*p++ = cap>>8;
+
+	/* interval */
+	*p++ = 16;
 	*p++ = 16>>8;
 
 	n = strlen(bss->ssid);