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>

1 files changed, 12 insertions, 94 deletions

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 289112777e9..6a88e8f9bff 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -613,11 +613,6 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 		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 @@ ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
 		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 @@ ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
 		       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 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 				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 @@ ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
 		 *	  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 @@ static int
 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 @@ ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
 		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 @@ ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
 		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 @@ ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
 		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 @@ ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
 
 		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 @@ ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
 			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 @@ static void ieee80211_rx_michael_mic_report(struct net_device *dev,
 	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 @@ static void ieee80211_rx_michael_mic_report(struct net_device *dev,
 		 * 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: