mac80211: rework debug settings and make debugging safer

This patch reworks the mac80211 debug settings making them more focused
and adding help text for those that didn't have one. It also removes a
number of printks that can be triggered remotely and add no value, e.g.
"too short deauthentication frame received - ignoring".

If somebody really needs to debug that they should just add a monitor
interface and look at the frames in wireshark.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 2891127..6a88e8f 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -613,11 +613,6 @@
 		rx->key->tx_rx_count++;
 		/* TODO: add threshold stuff again */
 	} else {
-#ifdef CONFIG_MAC80211_DEBUG
-		if (net_ratelimit())
-			printk(KERN_DEBUG "%s: RX protected frame,"
-			       " but have no key\n", rx->dev->name);
-#endif /* CONFIG_MAC80211_DEBUG */
 		return RX_DROP_MONITOR;
 	}
 
@@ -789,7 +784,7 @@
 		sdata->fragment_next = 0;
 
 	if (!skb_queue_empty(&entry->skb_list)) {
-#ifdef CONFIG_MAC80211_DEBUG
+#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 		struct ieee80211_hdr *hdr =
 			(struct ieee80211_hdr *) entry->skb_list.next->data;
 		DECLARE_MAC_BUF(mac);
@@ -801,7 +796,7 @@
 		       jiffies - entry->first_frag_time, entry->seq,
 		       entry->last_frag, print_mac(mac, hdr->addr1),
 		       print_mac(mac2, hdr->addr2));
-#endif /* CONFIG_MAC80211_DEBUG */
+#endif
 		__skb_queue_purge(&entry->skb_list);
 	}
 
@@ -922,18 +917,8 @@
 				break;
 		}
 		rpn = rx->key->u.ccmp.rx_pn[rx->queue];
-		if (memcmp(pn, rpn, CCMP_PN_LEN) != 0) {
-			if (net_ratelimit())
-				printk(KERN_DEBUG "%s: defrag: CCMP PN not "
-				       "sequential A2=%s"
-				       " PN=%02x%02x%02x%02x%02x%02x "
-				       "(expected %02x%02x%02x%02x%02x%02x)\n",
-				       rx->dev->name, print_mac(mac, hdr->addr2),
-				       rpn[0], rpn[1], rpn[2], rpn[3], rpn[4],
-				       rpn[5], pn[0], pn[1], pn[2], pn[3],
-				       pn[4], pn[5]);
+		if (memcmp(pn, rpn, CCMP_PN_LEN))
 			return RX_DROP_UNUSABLE;
-		}
 		memcpy(entry->last_pn, pn, CCMP_PN_LEN);
 	}
 
@@ -1037,7 +1022,7 @@
 		 *	  have nothing buffered for it?
 		 */
 		printk(KERN_DEBUG "%s: STA %s sent PS Poll even "
-		       "though there is no buffered frames for it\n",
+		       "though there are no buffered frames for it\n",
 		       rx->dev->name, print_mac(mac, rx->sta->addr));
 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 	}
@@ -1073,14 +1058,8 @@
 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
 {
 	if (unlikely(!rx->sta ||
-	    !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED))) {
-#ifdef CONFIG_MAC80211_DEBUG
-		if (net_ratelimit())
-			printk(KERN_DEBUG "%s: dropped frame "
-			       "(unauthorized port)\n", rx->dev->name);
-#endif /* CONFIG_MAC80211_DEBUG */
+	    !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
 		return -EACCES;
-	}
 
 	return 0;
 }
@@ -1160,16 +1139,8 @@
 		memcpy(src, hdr->addr2, ETH_ALEN);
 
 		if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_AP &&
-			     sdata->vif.type != IEEE80211_IF_TYPE_VLAN)) {
-			if (net_ratelimit())
-				printk(KERN_DEBUG "%s: dropped ToDS frame "
-				       "(BSSID=%s SA=%s DA=%s)\n",
-				       dev->name,
-				       print_mac(mac, hdr->addr1),
-				       print_mac(mac2, hdr->addr2),
-				       print_mac(mac3, hdr->addr3));
+			     sdata->vif.type != IEEE80211_IF_TYPE_VLAN))
 			return -1;
-		}
 		break;
 	case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
 		/* RA TA DA SA */
@@ -1177,17 +1148,8 @@
 		memcpy(src, hdr->addr4, ETH_ALEN);
 
 		 if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_WDS &&
-			     sdata->vif.type != IEEE80211_IF_TYPE_MESH_POINT)) {
-			 if (net_ratelimit())
-				 printk(KERN_DEBUG "%s: dropped FromDS&ToDS "
-				       "frame (RA=%s TA=%s DA=%s SA=%s)\n",
-				       rx->dev->name,
-				       print_mac(mac, hdr->addr1),
-				       print_mac(mac2, hdr->addr2),
-				       print_mac(mac3, hdr->addr3),
-				       print_mac(mac4, hdr->addr4));
+			     sdata->vif.type != IEEE80211_IF_TYPE_MESH_POINT))
 			return -1;
-		}
 		break;
 	case IEEE80211_FCTL_FROMDS:
 		/* DA BSSID SA */
@@ -1204,27 +1166,13 @@
 		memcpy(dst, hdr->addr1, ETH_ALEN);
 		memcpy(src, hdr->addr2, ETH_ALEN);
 
-		if (sdata->vif.type != IEEE80211_IF_TYPE_IBSS) {
-			if (net_ratelimit()) {
-				printk(KERN_DEBUG "%s: dropped IBSS frame "
-				       "(DA=%s SA=%s BSSID=%s)\n",
-				       dev->name,
-				       print_mac(mac, hdr->addr1),
-				       print_mac(mac2, hdr->addr2),
-				       print_mac(mac3, hdr->addr3));
-			}
+		if (sdata->vif.type != IEEE80211_IF_TYPE_IBSS)
 			return -1;
-		}
 		break;
 	}
 
-	if (unlikely(skb->len - hdrlen < 8)) {
-		if (net_ratelimit()) {
-			printk(KERN_DEBUG "%s: RX too short data frame "
-			       "payload\n", dev->name);
-		}
+	if (unlikely(skb->len - hdrlen < 8))
 		return -1;
-	}
 
 	payload = skb->data + hdrlen;
 	ethertype = (payload[6] << 8) | payload[7];
@@ -1416,10 +1364,8 @@
 
 		padding = ((4 - subframe_len) & 0x3);
 		/* the last MSDU has no padding */
-		if (subframe_len > remaining) {
-			printk(KERN_DEBUG "%s: wrong buffer size\n", dev->name);
+		if (subframe_len > remaining)
 			return RX_DROP_UNUSABLE;
-		}
 
 		skb_pull(skb, sizeof(struct ethhdr));
 		/* if last subframe reuse skb */
@@ -1440,8 +1386,6 @@
 			eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
 							padding);
 			if (!eth) {
-				printk(KERN_DEBUG "%s: wrong buffer size\n",
-				       dev->name);
 				dev_kfree_skb(frame);
 				return RX_DROP_UNUSABLE;
 			}
@@ -1593,31 +1537,16 @@
 	else
 		keyidx = -1;
 
-	if (net_ratelimit())
-		printk(KERN_DEBUG "%s: TKIP hwaccel reported Michael MIC "
-		       "failure from %s to %s keyidx=%d\n",
-		       dev->name, print_mac(mac, hdr->addr2),
-		       print_mac(mac2, hdr->addr1), keyidx);
-
 	if (!rx->sta) {
 		/*
 		 * Some hardware seem to generate incorrect Michael MIC
 		 * reports; ignore them to avoid triggering countermeasures.
 		 */
-		if (net_ratelimit())
-			printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
-			       "error for unknown address %s\n",
-			       dev->name, print_mac(mac, hdr->addr2));
 		goto ignore;
 	}
 
-	if (!(rx->fc & IEEE80211_FCTL_PROTECTED)) {
-		if (net_ratelimit())
-			printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
-			       "error for a frame with no PROTECTED flag (src "
-			       "%s)\n", dev->name, print_mac(mac, hdr->addr2));
+	if (!(rx->fc & IEEE80211_FCTL_PROTECTED))
 		goto ignore;
-	}
 
 	if (rx->sdata->vif.type == IEEE80211_IF_TYPE_AP && keyidx) {
 		/*
@@ -1626,24 +1555,13 @@
 		 * group keys and only the AP is sending real multicast
 		 * frames in the BSS.
 		 */
-		if (net_ratelimit())
-			printk(KERN_DEBUG "%s: ignored Michael MIC error for "
-			       "a frame with non-zero keyidx (%d)"
-			       " (src %s)\n", dev->name, keyidx,
-			       print_mac(mac, hdr->addr2));
 		goto ignore;
 	}
 
 	if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
 	    ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
-	     (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH)) {
-		if (net_ratelimit())
-			printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
-			       "error for a frame that cannot be encrypted "
-			       "(fc=0x%04x) (src %s)\n",
-			       dev->name, rx->fc, print_mac(mac, hdr->addr2));
+	     (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH))
 		goto ignore;
-	}
 
 	mac80211_ev_michael_mic_failure(rx->dev, keyidx, hdr);
  ignore: