PERFORCE change 81355 for review

[Sam Leffler]

http://perforce.freebsd.org/chv.cgi?CH=81355

Change 81355 by sam at sam_ebb on 2005/08/02 20:21:36

	count dynamic references and disallow module unload if any exist

Affected files ...

.. //depot/projects/wifi/sys/net80211/ieee80211_crypto_ccmp.c#9 edit
.. //depot/projects/wifi/sys/net80211/ieee80211_crypto_tkip.c#11 edit
.. //depot/projects/wifi/sys/net80211/ieee80211_crypto_wep.c#9 edit
.. //depot/projects/wifi/sys/net80211/ieee80211_scan_ap.c#2 edit
.. //depot/projects/wifi/sys/net80211/ieee80211_scan_sta.c#2 edit

Differences ...

==== //depot/projects/wifi/sys/net80211/ieee80211_crypto_ccmp.c#9 (text+ko) ====

@@ -91,6 +91,9 @@
 static	int ccmp_decrypt(struct ieee80211_key *, u_int64_t pn,
 		struct mbuf *, int hdrlen);
 
+/* number of references from net80211 layer */
+static	int nrefs = 0;
+
 static void *
 ccmp_attach(struct ieee80211com *ic, struct ieee80211_key *k)
 {
@@ -103,6 +106,7 @@
 		return NULL;
 	}
 	ctx->cc_ic = ic;
+	nrefs++;			/* NB: we assume caller locking */
 	return ctx;
 }
 
@@ -112,6 +116,8 @@
 	struct ccmp_ctx *ctx = k->wk_private;
 
 	FREE(ctx, M_DEVBUF);
+	KASSERT(nrefs > 0, ("imbalanced attach/detach"));
+	nrefs--;			/* NB: we assume caller locking */
 }
 
 static int
@@ -637,7 +643,14 @@
 		ieee80211_crypto_register(&ccmp);
 		return 0;
 	case MOD_UNLOAD:
-		ieee80211_crypto_unregister(&ccmp);
+	case MOD_QUIESCE:
+		if (nrefs) {
+			printf("wlan_ccmp: still in use (%u dynamic refs)\n",
+				nrefs);
+			return EBUSY;
+		}
+		if (type == MOD_UNLOAD)
+			ieee80211_crypto_unregister(&ccmp);
 		return 0;
 	}
 	return EINVAL;

==== //depot/projects/wifi/sys/net80211/ieee80211_crypto_tkip.c#11 (text+ko) ====

@@ -106,6 +106,9 @@
 static	int tkip_decrypt(struct tkip_ctx *, struct ieee80211_key *,
 		struct mbuf *, int hdr_len);
 
+/* number of references from net80211 layer */
+static	int nrefs = 0;
+
 static void *
 tkip_attach(struct ieee80211com *ic, struct ieee80211_key *k)
 {
@@ -119,6 +122,7 @@
 	}
 
 	ctx->tc_ic = ic;
+	nrefs++;			/* NB: we assume caller locking */
 	return ctx;
 }
 
@@ -128,6 +132,8 @@
 	struct tkip_ctx *ctx = k->wk_private;
 
 	FREE(ctx, M_DEVBUF);
+	KASSERT(nrefs > 0, ("imbalanced attach/detach"));
+	nrefs--;			/* NB: we assume caller locking */
 }
 
 static int
@@ -976,7 +982,14 @@
 		ieee80211_crypto_register(&tkip);
 		return 0;
 	case MOD_UNLOAD:
-		ieee80211_crypto_unregister(&tkip);
+	case MOD_QUIESCE:
+		if (nrefs) {
+			printf("wlan_tkip: still in use (%u dynamic refs)\n",
+				nrefs);
+			return EBUSY;
+		}
+		if (type == MOD_UNLOAD)
+			ieee80211_crypto_unregister(&tkip);
 		return 0;
 	}
 	return EINVAL;

==== //depot/projects/wifi/sys/net80211/ieee80211_crypto_wep.c#9 (text+ko) ====

@@ -82,6 +82,9 @@
 	u_int32_t	wc_iv;		/* initial vector for crypto */
 };
 
+/* number of references from net80211 layer */
+static	int nrefs = 0;
+
 static void *
 wep_attach(struct ieee80211com *ic, struct ieee80211_key *k)
 {
@@ -96,6 +99,7 @@
 
 	ctx->wc_ic = ic;
 	get_random_bytes(&ctx->wc_iv, sizeof(ctx->wc_iv));
+	nrefs++;			/* NB: we assume caller locking */
 	return ctx;
 }
 
@@ -105,6 +109,8 @@
 	struct wep_ctx *ctx = k->wk_private;
 
 	FREE(ctx, M_DEVBUF);
+	KASSERT(nrefs > 0, ("imbalanced attach/detach"));
+	nrefs--;			/* NB: we assume caller locking */
 }
 
 static int
@@ -481,7 +487,14 @@
 		ieee80211_crypto_register(&wep);
 		return 0;
 	case MOD_UNLOAD:
-		ieee80211_crypto_unregister(&wep);
+	case MOD_QUIESCE:
+		if (nrefs) {
+			printf("wlan_wep: still in use (%u dynamic refs)\n",
+				nrefs);
+			return EBUSY;
+		}
+		if (type == MOD_UNLOAD)
+			ieee80211_crypto_unregister(&wep);
 		return 0;
 	}
 	return EINVAL;

==== //depot/projects/wifi/sys/net80211/ieee80211_scan_ap.c#2 (text+ko) ====

@@ -56,6 +56,9 @@
 
 static int ap_flush(struct ieee80211_scan_state *);
 
+/* number of references from net80211 layer */
+static	int nrefs = 0;
+
 /*
  * Attach prior to any scanning work.
  */
@@ -68,6 +71,7 @@
 		M_80211_SCAN, M_NOWAIT);
 	ss->ss_priv = as;
 	ap_flush(ss);
+	nrefs++;			/* NB: we assume caller locking */
 	return 1;
 }
 
@@ -79,8 +83,11 @@
 {
 	struct ap_state *as = ss->ss_priv;
 
-	if (as != NULL)
+	if (as != NULL) {
+		KASSERT(nrefs > 0, ("imbalanced attach/detach"));
+		nrefs--;		/* NB: we assume caller locking */
 		FREE(as, M_80211_SCAN);
+	}
 	return 1;
 }
 
@@ -378,7 +385,14 @@
 		ieee80211_scanner_register(IEEE80211_M_HOSTAP, &ap_default);
 		return 0;
 	case MOD_UNLOAD:
-		ieee80211_scanner_unregister_all(&ap_default);
+	case MOD_QUIESCE:
+		if (nrefs) {
+			printf("wlan_scan_ap: still in use (%u dynamic refs)\n",
+				nrefs);
+			return EBUSY;
+		}
+		if (type == MOD_UNLOAD)
+			ieee80211_scanner_unregister_all(&ap_default);
 		return 0;
 	}
 	return EINVAL;

==== //depot/projects/wifi/sys/net80211/ieee80211_scan_sta.c#2 (text+ko) ====

@@ -110,6 +110,9 @@
 static int match_bss(struct ieee80211com *,
 	const struct ieee80211_scan_state *, const struct sta_entry *);
 
+/* number of references from net80211 layer */
+static	int nrefs = 0;
+
 /*
  * Attach prior to any scanning work.
  */
@@ -126,6 +129,7 @@
 	mtx_init(&st->st_scanlock, "scangen", "802.11 scangen", MTX_DEF);
 	TAILQ_INIT(&st->st_entry);
 	ss->ss_priv = st;
+	nrefs++;			/* NB: we assume caller locking */
 	return 1;
 }
 
@@ -142,6 +146,8 @@
 		mtx_destroy(&st->st_lock);
 		mtx_destroy(&st->st_scanlock);
 		FREE(st, M_80211_SCAN);
+		KASSERT(nrefs > 0, ("imbalanced attach/detach"));
+		nrefs--;		/* NB: we assume caller locking */
 	}
 	return 1;
 }
@@ -1345,8 +1351,16 @@
 		ieee80211_scanner_register(IEEE80211_M_AHDEMO, &adhoc_default);
 		return 0;
 	case MOD_UNLOAD:
-		ieee80211_scanner_unregister_all(&sta_default);
-		ieee80211_scanner_unregister_all(&adhoc_default);
+	case MOD_QUIESCE:
+		if (nrefs) {
+			printf("wlan_scan_sta: still in use (%u dynamic refs)\n",
+				nrefs);
+			return EBUSY;
+		}
+		if (type == MOD_UNLOAD) {
+			ieee80211_scanner_unregister_all(&sta_default);
+			ieee80211_scanner_unregister_all(&adhoc_default);
+		}
 		return 0;
 	}
 	return EINVAL;