wifi: send probe requests for hidden ssid

sys/src/9/pc/etheriwl.c

@@ -1846,6 +1846,7 @@ transmit(Wifi *wifi, Wnode *wn, Block *b)
 		return;
 	}
 
+	if(wn != nil)
 	if((wn->channel != ctlr->channel)
 	|| (!ctlr->prom && (wn->aid != ctlr->aid || memcmp(wn->bssid, ctlr->bssid, Eaddrlen) != 0)))
 		rxon(edev, wn);
@@ -2012,6 +2013,7 @@ iwlproc(void *arg)
 			ctlr->aid = 0;
 			rxon(edev, nil);
 			qunlock(ctlr);
+			wifiprobe(ctlr->wifi, ctlr->channel);
 			tsleep(&up->sleep, return0, 0, 1000);
 		}
 
@@ -2023,7 +2025,7 @@ iwlproc(void *arg)
 			tsleep(&up->sleep, return0, 0, 1000);
 		}
 
-		if(bss == nil)
+		if(wifi->bss == nil)
 			continue;
 
 		/* wait for disassociation */

sys/src/9/pc/wifi.c

@@ -132,7 +132,8 @@ wifitx(Wifi *wifi, Wnode *wn, Block *b)
 	Wifipkt *w;
 	uint seq;
 
-	wn->lastsend = MACHP(0)->ticks;
+	if(wn != nil)
+		wn->lastsend = MACHP(0)->ticks;
 	seq = incref(&wifi->txseq);
 	seq <<= 4;
 
@@ -142,7 +143,7 @@ wifitx(Wifi *wifi, Wnode *wn, Block *b)
 	w->seq[0] = seq;
 	w->seq[1] = seq>>8;
 
-	if((w->fc[0] & 0x0c) != 0x00)
+	if((w->fc[0] & 0x0c) != 0x00 && wn != nil)
 		b = wifiencrypt(wifi, wn, b);
 
 	if(b != nil)
@@ -182,6 +183,50 @@ nodelookup(Wifi *wifi, uchar *bssid, int new)
 	return nn;
 }
 
+void
+wifiprobe(Wifi *wifi, int channel)
+{
+	Wifipkt *w;
+	Block *b;
+	uchar *p;
+	int n;
+
+	n = strlen(wifi->essid);
+	if(n == 0)
+		return;
+
+	b = allocb(WIFIHDRSIZE + 512);
+	w = (Wifipkt*)b->wp;
+	w->fc[0] = 0x40;	/* probe request */
+	w->fc[1] = 0x00;	/* STA->STA */
+	memmove(w->a1, wifi->ether->bcast, Eaddrlen);	/* ??? */
+	memmove(w->a2, wifi->ether->ea, Eaddrlen);
+	memmove(w->a3, wifi->ether->bcast, Eaddrlen);
+	b->wp += WIFIHDRSIZE;
+	p = b->wp;
+
+	*p++ = 0x00;	/* set */
+	*p++ = n;
+	memmove(p, wifi->essid, n);
+	p += n;
+
+	*p++ = 1;	/* RATES (BUG: these are all lies!) */
+	*p++ = 4;
+	*p++ = 0x82;
+	*p++ = 0x84;
+	*p++ = 0x8b;
+	*p++ = 0x96;
+
+	if(channel > 0){
+		*p++ = 0x03;	/* ds parameter set */
+		*p++ = 1;
+		*p++ = channel;
+	}
+
+	b->wp = p;
+	wifitx(wifi, nil, b);
+}
+
 static void
 sendauth(Wifi *wifi, Wnode *bss)
 {
@@ -425,6 +470,9 @@ wifiproc(void *arg)
 
 		switch(w->fc[0] & 0xf0){
 		case 0x50:	/* probe response */
+			if(wifi->debug)
+				print("#l%d: got probe from %E\n", wifi->ether->ctlrno, w->a3);
+			/* no break */
 		case 0x80:	/* beacon */
 			if((wn = nodelookup(wifi, w->a3, 1)) == nil)
 				continue;

sys/src/9/pc/wifi.h

@@ -83,3 +83,4 @@ long wifistat(Wifi*, void*, long, ulong);
 long wifictl(Wifi*, void*, long);
 
 int wifichecklink(Wifi*);
+void wifiprobe(Wifi*, int);