openwrtv4/package/madwifi/patches/451-ibss_race_fix.patch

--- a/net80211/ieee80211_input.c
+++ b/net80211/ieee80211_input.c
@@ -294,10 +294,10 @@ ieee80211_input(struct ieee80211vap * va
 			break;
 		case IEEE80211_M_IBSS:
 		case IEEE80211_M_AHDEMO:
-			if (!IEEE80211_ADDR_EQ(wh->i_addr3, vap->iv_bssid) ||
+			if ((!IEEE80211_ADDR_EQ(wh->i_addr3, vap->iv_bssid) ||
 			    (!IEEE80211_ADDR_EQ(wh->i_addr1, vap->iv_myaddr) &&
-			     !IEEE80211_IS_MULTICAST(wh->i_addr1) &&
-			     (subtype != IEEE80211_FC0_SUBTYPE_BEACON))) {
+			     !IEEE80211_IS_MULTICAST(wh->i_addr1))) &&
+			     (type == IEEE80211_FC0_TYPE_DATA)) {
 				if (!(vap->iv_dev->flags & IFF_PROMISC)) {
 					IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
 						bssid, NULL, "%s", "not to bss");
@@ -322,22 +322,15 @@ ieee80211_input(struct ieee80211vap * va
 			}
 			/* Do not try to find a node reference if the packet really did come from the BSS */
 			if (type == IEEE80211_FC0_TYPE_DATA && ni == vap->iv_bss &&
-					!IEEE80211_ADDR_EQ(vap->iv_bss->ni_macaddr, wh->i_addr2) &&
 					IEEE80211_ADDR_EQ(vap->iv_bssid, wh->i_addr3)) {
 				/* Try to find sender in local node table. */
-				ni = ieee80211_find_node(&ic->ic_sta, wh->i_addr2);
+				if (!ni_or_null) {
+					ieee80211_unref_node(&ni);
+					ni = ieee80211_find_txnode(vap, wh->i_addr2);
+				}
 				if (ni == NULL) {
-					/*
-					 * Fake up a node for this newly discovered
-					 * member of the IBSS.  This should probably
-					 * done after an ACL check.
-					 */
-					ni = ieee80211_fakeup_adhoc_node(vap,
-							wh->i_addr2);
-					if (ni == NULL) {
-						/* NB: stat kept for alloc failure */
-						goto err;
-					}
+					/* NB: stat kept for alloc failure */
+					goto discard;
 				}
 			}
 			iwspy_event(vap, ni, rssi);
@@ -3553,8 +3546,8 @@ ieee80211_recv_mgmt(struct ieee80211vap 
 				(((vap->iv_opmode == IEEE80211_M_HOSTAP) ||
 				 (vap->iv_opmode == IEEE80211_M_WDS)) &&
 				(scan.capinfo & IEEE80211_CAPINFO_ESS))) {
+			struct ieee80211_node *tni = NULL;
 			struct ieee80211vap *avp = NULL;
-			int do_unref = 0;
 			int found = 0;
 
 			IEEE80211_LOCK_IRQ(vap->iv_ic);
@@ -3568,14 +3561,12 @@ ieee80211_recv_mgmt(struct ieee80211vap 
 					}
 				}
 				if (found)
-					ni = ni_or_null = avp->iv_wdsnode;
+					tni = ieee80211_ref_node(avp->iv_wdsnode);
 			} else if (vap->iv_opmode == IEEE80211_M_WDS) {
 				found = 1;
-				ni = ni_or_null = vap->iv_wdsnode;
-			} else if (vap->iv_opmode == IEEE80211_M_IBSS) {
-				ni_or_null = ieee80211_find_node(&ic->ic_sta, wh->i_addr2);
-				if (ni_or_null)
-					ni = ni_or_null;
+				tni = ieee80211_ref_node(vap->iv_wdsnode);
+			} else if ((vap->iv_opmode == IEEE80211_M_IBSS) && (vap->iv_state == IEEE80211_S_RUN)) {
+				tni = ieee80211_find_node(&ic->ic_sta, wh->i_addr2);
 				found = 1;
 			}
 			IEEE80211_UNLOCK_IRQ(vap->iv_ic);
@@ -3583,20 +3574,21 @@ ieee80211_recv_mgmt(struct ieee80211vap 
 			if (!found)
 				break;
 
-			if (ni_or_null == NULL) {
+			memcpy(&SKB_CB(skb)->beacon_tsf, scan.tstamp, sizeof(u_int64_t));
+
+			if (tni == NULL) {
 				if (avp) {
 					IEEE80211_LOCK_IRQ(ic);
-					ni = ieee80211_add_neighbor(avp, wh, &scan);
+					tni = ieee80211_add_neighbor(avp, wh, &scan);
 					/* force assoc */
-					ni->ni_associd |= 0xc000;
-					avp->iv_wdsnode = ieee80211_ref_node(ni);
+					tni->ni_associd |= 0xc000;
+					avp->iv_wdsnode = ieee80211_ref_node(tni);
 					IEEE80211_UNLOCK_IRQ(ic);
 				} else if ((vap->iv_opmode == IEEE80211_M_IBSS) &&
 				           IEEE80211_ADDR_EQ(wh->i_addr3, vap->iv_bssid)) {
 					/* Create a new entry in the neighbor table. */
-					ni = ieee80211_add_neighbor(vap, wh, &scan);
+					tni = ieee80211_add_neighbor(vap, wh, &scan);
 				}
-				do_unref = 1;
 			} else {
 				/*
 				 * Copy data from beacon to neighbor table.
@@ -3604,39 +3596,38 @@ ieee80211_recv_mgmt(struct ieee80211vap 
 				 * ieee80211_add_neighbor(), so we just copy
 				 * everything over to be safe.
 				 */
-				ni->ni_esslen = scan.ssid[1];
-				memcpy(ni->ni_essid, scan.ssid + 2, scan.ssid[1]);
-				IEEE80211_ADDR_COPY(ni->ni_bssid, wh->i_addr3);
-				memcpy(ni->ni_tstamp.data, scan.tstamp,
-					sizeof(ni->ni_tstamp));
-				ni->ni_inact = ni->ni_inact_reload;
-				ni->ni_intval = 
+				tni->ni_esslen = scan.ssid[1];
+				memcpy(tni->ni_essid, scan.ssid + 2, scan.ssid[1]);
+				IEEE80211_ADDR_COPY(tni->ni_bssid, wh->i_addr3);
+				memcpy(tni->ni_tstamp.data, scan.tstamp,
+					sizeof(tni->ni_tstamp));
+				tni->ni_inact = tni->ni_inact_reload;
+				tni->ni_intval =
 					IEEE80211_BINTVAL_SANITISE(scan.bintval);
-				ni->ni_capinfo = scan.capinfo;
-				ni->ni_chan = ic->ic_curchan;
-				ni->ni_fhdwell = scan.fhdwell;
-				ni->ni_fhindex = scan.fhindex;
-				ni->ni_erp = scan.erp;
-				ni->ni_timoff = scan.timoff;
+				tni->ni_capinfo = scan.capinfo;
+				tni->ni_chan = ic->ic_curchan;
+				tni->ni_fhdwell = scan.fhdwell;
+				tni->ni_fhindex = scan.fhindex;
+				tni->ni_erp = scan.erp;
+				tni->ni_timoff = scan.timoff;
 				if (scan.wme != NULL)
-					ieee80211_saveie(&ni->ni_wme_ie, scan.wme);
+					ieee80211_saveie(&tni->ni_wme_ie, scan.wme);
 				if (scan.wpa != NULL)
-					ieee80211_saveie(&ni->ni_wpa_ie, scan.wpa);
+					ieee80211_saveie(&tni->ni_wpa_ie, scan.wpa);
 				if (scan.rsn != NULL)
-					ieee80211_saveie(&ni->ni_rsn_ie, scan.rsn);
+					ieee80211_saveie(&tni->ni_rsn_ie, scan.rsn);
 				if (scan.ath != NULL)
-					ieee80211_saveath(ni, scan.ath);
+					ieee80211_saveath(tni, scan.ath);
 
 				/* NB: must be after ni_chan is setup */
-				ieee80211_setup_rates(ni, scan.rates,
+				ieee80211_setup_rates(tni, scan.rates,
 					scan.xrates, IEEE80211_F_DOSORT);
 			}
-			if (ni != NULL) {
-				ni->ni_rssi = rssi;
-				ni->ni_rtsf = rtsf;
-				ni->ni_last_rx = jiffies;
-				if (do_unref)
-					ieee80211_unref_node(&ni);
+			if (tni != NULL) {
+				tni->ni_rssi = rssi;
+				tni->ni_rtsf = rtsf;
+				tni->ni_last_rx = jiffies;
+				ieee80211_unref_node(&tni);
 			}
 		}
 		break;
--- a/net80211/ieee80211_node.c
+++ b/net80211/ieee80211_node.c
@@ -53,6 +53,7 @@
 
 #include <net80211/ieee80211_var.h>
 #include <net80211/if_athproto.h>
+#include <net80211/ieee80211_node.h>
 
 /*
  * Association IDs are managed with a bit vector.
@@ -317,16 +318,11 @@ ieee80211_create_ibss(struct ieee80211va
 	/* Check to see if we already have a node for this mac
 	 * NB: we gain a node reference here
 	 */
-	ni = ieee80211_find_txnode(vap, vap->iv_myaddr);
+	ieee80211_node_table_reset(&ic->ic_sta, vap);
+	ni = ieee80211_alloc_node_table(vap, vap->iv_myaddr);
 	if (ni == NULL) {
-		ni = ieee80211_alloc_node_table(vap, vap->iv_myaddr);
-		IEEE80211_DPRINTF(vap, IEEE80211_MSG_ASSOC,
-				  "%s: ni:%p allocated for " MAC_FMT "\n",
-				  __func__, ni, MAC_ADDR(vap->iv_myaddr));
-		if (ni == NULL) {
-			/* XXX recovery? */
-			return;
-		}
+		/* XXX recovery? */
+		return;
 	}
 
 	IEEE80211_ADDR_COPY(ni->ni_bssid, vap->iv_myaddr);
@@ -647,7 +643,7 @@ ieee80211_sta_join1(struct ieee80211_nod
 		(vap->iv_state == IEEE80211_S_RUN) && bssid_equal(obss, selbs)); */
 	vap->iv_bss = selbs;
 	IEEE80211_ADDR_COPY(vap->iv_bssid, selbs->ni_bssid);
-	if (obss != NULL) {
+	if ((obss != NULL) && (obss != selbs)) {
 		if (obss->ni_table)
 			ieee80211_node_leave(obss);
 		ieee80211_unref_node(&obss);
--- a/ath/if_ath.c
+++ b/ath/if_ath.c
@@ -6625,14 +6625,6 @@ ath_recv_mgmt(struct ieee80211vap * vap,
 
 	sc->sc_recv_mgmt(vap, ni_or_null, skb, subtype, rssi, rtsf);
 
-	/* Lookup the new node if any (this grabs a reference to it) */
-	ni = ieee80211_find_rxnode(vap->iv_ic, vap,
-	         (const struct ieee80211_frame_min *)skb->data);
-	if (ni == NULL) {
-		DPRINTF(sc, ATH_DEBUG_BEACON, "Dropping; node unknown.\n");
-		return;
-	}
-
 	switch (subtype) {
 	case IEEE80211_FC0_SUBTYPE_BEACON:
 		/* update RSSI statistics for use by the HAL */
@@ -6654,11 +6646,9 @@ ath_recv_mgmt(struct ieee80211vap * vap,
 			 * we do the IBSS merging in software. Also do not merge
 			 * if the difference it too small. Otherwise we are playing
 			 * tsf-pingpong with other vendors drivers */
-			beacon_tsf = le64_to_cpu(ni->ni_tstamp.tsf);
-			if (beacon_tsf > rtsf + 0xffff) {
+			beacon_tsf = le64_to_cpu(SKB_CB(skb)->beacon_tsf);
+			if (beacon_tsf > rtsf + 0xffff)
 				ath_hal_settsf64(sc->sc_ah, beacon_tsf - rtsf);
-				ieee80211_ibss_merge(ni);
-			}
 			break;
 		}
 		/* NB: Fall Through */
@@ -6680,13 +6670,21 @@ ath_recv_mgmt(struct ieee80211vap * vap,
 			hw_tsf = ath_hal_gettsf64(sc->sc_ah);
 			hw_tu  = hw_tsf >> 10;
 
-			beacon_tsf = le64_to_cpu(ni->ni_tstamp.tsf);
+			beacon_tsf = le64_to_cpu(SKB_CB(skb)->beacon_tsf);
 			beacon_tu  = beacon_tsf >> 10;
 
+			if (!beacon_tsf)
+				break;
+
+			if (IEEE80211_ADDR_EQ(wh->i_addr3, vap->iv_bssid))
+				break;
+
 			DPRINTF(sc, ATH_DEBUG_BEACON,
-					"Beacon transmitted at %10llx, "
+					"Beacon transmitted from "MAC_FMT" ("MAC_FMT") at %10llx, "
 					"received at %10llx(%lld), hw TSF "
 					"%10llx(%lld)\n",
+					MAC_ADDR(wh->i_addr3),
+					MAC_ADDR(vap->iv_bssid),
 					beacon_tsf,
 					rtsf, rtsf - beacon_tsf,
 					hw_tsf, hw_tsf - beacon_tsf);
@@ -6699,39 +6697,13 @@ ath_recv_mgmt(struct ieee80211vap * vap,
 				do_merge = 1;
 			}
 
-			/* Check sc_nexttbtt */
-			if (sc->sc_nexttbtt < hw_tu) {
-				DPRINTF(sc, ATH_DEBUG_BEACON,
-					"sc_nexttbtt (%8x TU) is in the past "
-					"(tsf %8x TU), updating timers\n",
-					sc->sc_nexttbtt, hw_tu);
-				do_merge = 1;
-			}
-
-			intval = ni->ni_intval & HAL_BEACON_PERIOD;
-#if 0
-			/* This code is disabled since it would produce
-			 * unwanted merge. For instance, in a two nodes network
-			 * A & B, A can merge to B and at the same time, B will
-			 * merge to A, still having a split */
-			if (intval != 0) {
-				if ((sc->sc_nexttbtt % intval) !=
-						(beacon_tu % intval)) {
-					DPRINTF(sc, ATH_DEBUG_BEACON,
-							"ibss merge: "
-							"sc_nexttbtt %10x TU "
-							"(%3d) beacon %10x TU "
-							"(%3d)\n",
-							sc->sc_nexttbtt,
-							sc->sc_nexttbtt % intval,
-							beacon_tu,
-							beacon_tu % intval);
-					do_merge = 1;
-				}
-			}
-#endif
-			if (do_merge)
+			if (do_merge) {
+				/* Lookup the new node if any (this grabs a reference to it) */
+				ni = ieee80211_find_txnode(vap, wh->i_addr2);
+				memcpy(ni->ni_bssid, wh->i_addr3, IEEE80211_ADDR_LEN);
 				ieee80211_ibss_merge(ni);
+				ieee80211_unref_node(&ni);
+			}
 
 			if ((sc->sc_opmode == HAL_M_IBSS) &&
 					ath_hw_check_atim(sc, 1, vap->iv_bss->ni_intval))
@@ -6739,8 +6711,6 @@ ath_recv_mgmt(struct ieee80211vap * vap,
 		}
 		break;
 	}
-
-	ieee80211_unref_node(&ni);
 }
 
 static void
--- a/net80211/ieee80211_linux.h
+++ b/net80211/ieee80211_linux.h
@@ -411,7 +411,7 @@ typedef spinlock_t acl_lock_t;
  *     8 bytes so we reserve/avoid it.
  */
 	struct ieee80211_cb {
-	u_int8_t vlan[8];			/* reserve for vlan tag info */
+	u_int64_t beacon_tsf;
 	struct ieee80211_node *ni;
 	u_int32_t flags;
 #define	M_LINK0		0x01			/* frame needs WEP encryption */
--- a/net80211/ieee80211_scan_sta.c
+++ b/net80211/ieee80211_scan_sta.c
@@ -1125,11 +1125,8 @@ adhoc_default_action(struct ieee80211vap
 	u_int8_t zeroMacAddr[IEEE80211_ADDR_LEN];
 
 	memset(&zeroMacAddr, 0, IEEE80211_ADDR_LEN);
-	if (IEEE80211_ADDR_EQ(se->se_bssid, &zeroMacAddr[0])) {
-		ieee80211_create_ibss(vap, se->se_chan);
-		return 1;
-	} else
-		return ieee80211_sta_join(vap, se);
+	ieee80211_create_ibss(vap, se->se_chan);
+	return 1;
 }
 
 static const struct ieee80211_scanner adhoc_default = {