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>

net/mac80211/Kconfig

@@ -88,10 +88,16 @@ config MAC80211_DEBUGFS
 
 	  Say N unless you know you need this.
 
+menuconfig MAC80211_DEBUG_MENU
+	bool "Select mac80211 debugging features"
+	depends on MAC80211
+	---help---
+	  This option collects various mac80211 debug settings.
+
 config MAC80211_DEBUG_PACKET_ALIGNMENT
 	bool "Enable packet alignment debugging"
-	depends on MAC80211
-	help
+	depends on MAC80211_DEBUG_MENU
+	---help---
 	  This option is recommended for driver authors and strongly
 	  discouraged for everybody else, it will trigger a warning
 	  when a driver hands mac80211 a buffer that is aligned in
@@ -100,33 +106,95 @@ config MAC80211_DEBUG_PACKET_ALIGNMENT
 
 	  Say N unless you're writing a mac80211 based driver.
 
-config MAC80211_DEBUG
-	bool "Enable debugging output"
-	depends on MAC80211
+config MAC80211_NOINLINE
+	bool "Do not inline TX/RX handlers"
+	depends on MAC80211_DEBUG_MENU
 	---help---
-	  This option will enable debug tracing output for the
-	  ieee80211 network stack.
+	  This option affects code generation in mac80211, when
+	  selected some functions are marked "noinline" to allow
+	  easier debugging of problems in the transmit and receive
+	  paths.
+
+	  This option increases code size a bit and inserts a lot
+	  of function calls in the code, but is otherwise safe to
+	  enable.
 
-	  If you are not trying to debug or develop the ieee80211
-	  subsystem, you most likely want to say N here.
+	  If unsure, say N unless you expect to be finding problems
+	  in mac80211.
+
+config MAC80211_VERBOSE_DEBUG
+	bool "Verbose debugging output"
+	depends on MAC80211_DEBUG_MENU
+	---help---
+	  Selecting this option causes mac80211 to print out
+	  many debugging messages. It should not be selected
+	  on production systems as some of the messages are
+	  remotely triggerable.
+
+	  Do not select this option.
 
 config MAC80211_HT_DEBUG
-	bool "Enable HT debugging output"
-	depends on MAC80211_DEBUG
+	bool "Verbose HT debugging"
+	depends on MAC80211_DEBUG_MENU
 	---help---
 	  This option enables 802.11n High Throughput features
 	  debug tracing output.
 
-	  If you are not trying to debug of develop the ieee80211
-	  subsystem, you most likely want to say N here.
+	  It should not be selected on production systems as some
+	  of the messages are remotely triggerable.
 
-config MAC80211_VERBOSE_DEBUG
-	bool "Verbose debugging output"
-	depends on MAC80211_DEBUG
+	  Do not select this option.
+
+config MAC80211_TKIP_DEBUG
+	bool "Verbose TKIP debugging"
+	depends on MAC80211_DEBUG_MENU
+	---help---
+	  Selecting this option causes mac80211 to print out
+	  very verbose TKIP debugging messages. It should not
+	  be selected on production systems as those messages
+	  are remotely triggerable.
+
+	  Do not select this option.
+
+config MAC80211_IBSS_DEBUG
+	bool "Verbose IBSS debugging"
+	depends on MAC80211_DEBUG_MENU
+	---help---
+	  Selecting this option causes mac80211 to print out
+	  very verbose IBSS debugging messages. It should not
+	  be selected on production systems as those messages
+	  are remotely triggerable.
+
+	  Do not select this option.
+
+config MAC80211_VERBOSE_PS_DEBUG
+	bool "Verbose powersave mode debugging"
+	depends on MAC80211_DEBUG_MENU
+	---help---
+	  Selecting this option causes mac80211 to print out very
+	  verbose power save mode debugging messages (when mac80211
+	  is an AP and has power saving stations.)
+	  It should not be selected on production systems as those
+	  messages are remotely triggerable.
+
+	  Do not select this option.
+
+config MAC80211_VERBOSE_MPL_DEBUG
+	bool "Verbose mesh peer link debugging"
+	depends on MAC80211_DEBUG_MENU
+	depends on MAC80211_MESH
+	---help---
+	  Selecting this option causes mac80211 to print out very
+	  verbose mesh peer link debugging messages (when mac80211
+	  is taking part in a mesh network).
+	  It should not be selected on production systems as those
+	  messages are remotely triggerable.
+
+	  Do not select this option.
 
 config MAC80211_LOWTX_FRAME_DUMP
 	bool "Debug frame dumping"
-	depends on MAC80211_DEBUG
+	depends on MAC80211_DEBUG_MENU
 	---help---
 	  Selecting this option will cause the stack to
 	  print a message for each frame that is handed
@@ -137,33 +205,17 @@ config MAC80211_LOWTX_FRAME_DUMP
 	  If unsure, say N and insert the debugging code
 	  you require into the driver you are debugging.
 
-config MAC80211_TKIP_DEBUG
-	bool "TKIP debugging"
-	depends on MAC80211_DEBUG
-
 config MAC80211_DEBUG_COUNTERS
 	bool "Extra statistics for TX/RX debugging"
 	depends on MAC80211_DEBUG
-
-config MAC80211_IBSS_DEBUG
-	bool "Support for IBSS testing"
-	depends on MAC80211_DEBUG
-	---help---
-	  Say Y here if you intend to debug the IBSS code.
-
-config MAC80211_VERBOSE_PS_DEBUG
-	bool "Verbose powersave mode debugging"
-	depends on MAC80211_DEBUG
+	depends on MAC80211_DEBUG_MENU
+	depends on MAC80211_DEBUGFS
 	---help---
-	  Say Y here to print out verbose powersave
-	  mode debug messages.
+	  Selecting this option causes mac80211 to keep additional
+	  and very verbose statistics about TX and RX handler use
+	  and show them in debugfs.
 
-config MAC80211_VERBOSE_MPL_DEBUG
-	bool "Verbose mesh peer link debugging"
-	depends on MAC80211_DEBUG && MAC80211_MESH
-	---help---
-	  Say Y here to print out verbose mesh peer link
-	  debug messages.
+	  If unsure, say N.
 
 config MAC80211_VERBOSE_SPECT_MGMT_DEBUG
 	bool "Verbose Spectrum Management (IEEE 802.11h)debugging"

net/mac80211/ieee80211_i.h

@@ -954,7 +954,7 @@ int ieee80211_frame_duration(struct ieee80211_local *local, size_t len,
 void mac80211_ev_michael_mic_failure(struct net_device *dev, int keyidx,
 				     struct ieee80211_hdr *hdr);
 
-#ifdef CONFIG_MAC80211_DEBUG
+#ifdef CONFIG_MAC80211_NOINLINE
 #define debug_noinline noinline
 #else
 #define debug_noinline

net/mac80211/iface.c

@@ -184,9 +184,9 @@ void ieee80211_if_set_type(struct net_device *dev, int type)
 		sdata->u.mntr_flags = MONITOR_FLAG_CONTROL |
 				      MONITOR_FLAG_OTHER_BSS;
 		break;
-	default:
-		printk(KERN_WARNING "%s: %s: Unknown interface type 0x%x",
-		       dev->name, __func__, type);
+	case IEEE80211_IF_TYPE_INVALID:
+		BUG();
+		break;
 	}
 	ieee80211_debugfs_change_if_type(sdata, oldtype);
 }

net/mac80211/main.c

@@ -151,9 +151,7 @@ static int ieee80211_change_mtu(struct net_device *dev, int new_mtu)
 	/* FIX: what would be proper limits for MTU?
 	 * This interface uses 802.3 frames. */
 	if (new_mtu < 256 ||
-		new_mtu > IEEE80211_MAX_DATA_LEN - 24 - 6 - meshhdrlen) {
-		printk(KERN_WARNING "%s: invalid MTU %d\n",
-		       dev->name, new_mtu);
+	    new_mtu > IEEE80211_MAX_DATA_LEN - 24 - 6 - meshhdrlen) {
 		return -EINVAL;
 	}
 
@@ -589,7 +587,9 @@ int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
 
 	sta = sta_info_get(local, ra);
 	if (!sta) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
 		printk(KERN_DEBUG "Could not find the station\n");
+#endif
 		ret = -ENOENT;
 		goto exit;
 	}
@@ -617,9 +617,11 @@ int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
 	sta->ampdu_mlme.tid_tx[tid] =
 			kmalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
 	if (!sta->ampdu_mlme.tid_tx[tid]) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
 		if (net_ratelimit())
 			printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
 					tid);
+#endif
 		ret = -ENOMEM;
 		goto err_unlock_sta;
 	}
@@ -689,7 +691,9 @@ int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
 	sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.expires =
 				jiffies + ADDBA_RESP_INTERVAL;
 	add_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
+#ifdef CONFIG_MAC80211_HT_DEBUG
 	printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
+#endif
 	goto exit;
 
 err_unlock_queue:
@@ -771,26 +775,32 @@ void ieee80211_start_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u16 tid)
 	DECLARE_MAC_BUF(mac);
 
 	if (tid >= STA_TID_NUM) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
 		printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 				tid, STA_TID_NUM);
+#endif
 		return;
 	}
 
 	rcu_read_lock();
 	sta = sta_info_get(local, ra);
 	if (!sta) {
 		rcu_read_unlock();
+#ifdef CONFIG_MAC80211_HT_DEBUG
 		printk(KERN_DEBUG "Could not find station: %s\n",
 				print_mac(mac, ra));
+#endif
 		return;
 	}
 
 	state = &sta->ampdu_mlme.tid_state_tx[tid];
 	spin_lock_bh(&sta->lock);
 
 	if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
 		printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
 				*state);
+#endif
 		spin_unlock_bh(&sta->lock);
 		rcu_read_unlock();
 		return;
@@ -801,7 +811,9 @@ void ieee80211_start_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u16 tid)
 	*state |= HT_ADDBA_DRV_READY_MSK;
 
 	if (*state == HT_AGG_STATE_OPERATIONAL) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
 		printk(KERN_DEBUG "Aggregation is on for tid %d \n", tid);
+#endif
 		ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
 	}
 	spin_unlock_bh(&sta->lock);
@@ -818,8 +830,10 @@ void ieee80211_stop_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u8 tid)
 	DECLARE_MAC_BUF(mac);
 
 	if (tid >= STA_TID_NUM) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
 		printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 				tid, STA_TID_NUM);
+#endif
 		return;
 	}
 
@@ -831,8 +845,10 @@ void ieee80211_stop_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u8 tid)
 	rcu_read_lock();
 	sta = sta_info_get(local, ra);
 	if (!sta) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
 		printk(KERN_DEBUG "Could not find station: %s\n",
 				print_mac(mac, ra));
+#endif
 		rcu_read_unlock();
 		return;
 	}
@@ -842,7 +858,9 @@ void ieee80211_stop_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u8 tid)
 	 * ieee80211_stop_tx_ba_session will let only
 	 * one stop call to pass through per sta/tid */
 	if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
 		printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
+#endif
 		rcu_read_unlock();
 		return;
 	}
@@ -884,9 +902,11 @@ void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
 	struct sk_buff *skb = dev_alloc_skb(0);
 
 	if (unlikely(!skb)) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
 		if (net_ratelimit())
 			printk(KERN_WARNING "%s: Not enough memory, "
 			       "dropping start BA session", skb->dev->name);
+#endif
 		return;
 	}
 	ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
@@ -907,9 +927,11 @@ void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
 	struct sk_buff *skb = dev_alloc_skb(0);
 
 	if (unlikely(!skb)) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
 		if (net_ratelimit())
 			printk(KERN_WARNING "%s: Not enough memory, "
 			       "dropping stop BA session", skb->dev->name);
+#endif
 		return;
 	}
 	ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
@@ -1236,9 +1258,8 @@ static void ieee80211_tasklet_handler(unsigned long data)
 						 ra_tid->ra, ra_tid->tid);
 			dev_kfree_skb(skb);
 			break ;
-		default: /* should never get here! */
-			printk(KERN_ERR "%s: Unknown message type (%d)\n",
-			       wiphy_name(local->hw.wiphy), skb->pkt_type);
+		default:
+			WARN_ON(1);
 			dev_kfree_skb(skb);
 			break;
 		}
@@ -1365,12 +1386,14 @@ static void ieee80211_handle_filtered_frame(struct ieee80211_local *local,
 		return;
 	}
 
+#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 	if (net_ratelimit())
 		printk(KERN_DEBUG "%s: dropped TX filtered frame, "
 		       "queue_len=%d PS=%d @%lu\n",
 		       wiphy_name(local->hw.wiphy),
 		       skb_queue_len(&sta->tx_filtered),
 		       !!test_sta_flags(sta, WLAN_STA_PS), jiffies);
+#endif
 	dev_kfree_skb(skb);
 }