File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/net/wireless/lib80211.c b/net/wireless/lib80211.c
new file mode 100644
index 0000000..4596115
--- /dev/null
+++ b/net/wireless/lib80211.c
@@ -0,0 +1,257 @@
+/*
+ * lib80211 -- common bits for IEEE802.11 drivers
+ *
+ * Copyright(c) 2008 John W. Linville <linville@tuxdriver.com>
+ *
+ * Portions copied from old ieee80211 component, w/ original copyright
+ * notices below:
+ *
+ * Host AP crypto routines
+ *
+ * Copyright (c) 2002-2003, Jouni Malinen <j@w1.fi>
+ * Portions Copyright (C) 2004, Intel Corporation <jketreno@linux.intel.com>
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/ctype.h>
+#include <linux/ieee80211.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include <net/lib80211.h>
+
+#define DRV_NAME        "lib80211"
+
+#define DRV_DESCRIPTION	"common routines for IEEE802.11 drivers"
+
+MODULE_DESCRIPTION(DRV_DESCRIPTION);
+MODULE_AUTHOR("John W. Linville <linville@tuxdriver.com>");
+MODULE_LICENSE("GPL");
+
+struct lib80211_crypto_alg {
+	struct list_head list;
+	struct lib80211_crypto_ops *ops;
+};
+
+static LIST_HEAD(lib80211_crypto_algs);
+static DEFINE_SPINLOCK(lib80211_crypto_lock);
+
+static void lib80211_crypt_deinit_entries(struct lib80211_crypt_info *info,
+					  int force);
+static void lib80211_crypt_quiescing(struct lib80211_crypt_info *info);
+static void lib80211_crypt_deinit_handler(unsigned long data);
+
+int lib80211_crypt_info_init(struct lib80211_crypt_info *info, char *name,
+				spinlock_t *lock)
+{
+	memset(info, 0, sizeof(*info));
+
+	info->name = name;
+	info->lock = lock;
+
+	INIT_LIST_HEAD(&info->crypt_deinit_list);
+	setup_timer(&info->crypt_deinit_timer, lib80211_crypt_deinit_handler,
+			(unsigned long)info);
+
+	return 0;
+}
+EXPORT_SYMBOL(lib80211_crypt_info_init);
+
+void lib80211_crypt_info_free(struct lib80211_crypt_info *info)
+{
+	int i;
+
+        lib80211_crypt_quiescing(info);
+        del_timer_sync(&info->crypt_deinit_timer);
+        lib80211_crypt_deinit_entries(info, 1);
+
+        for (i = 0; i < NUM_WEP_KEYS; i++) {
+                struct lib80211_crypt_data *crypt = info->crypt[i];
+                if (crypt) {
+                        if (crypt->ops) {
+                                crypt->ops->deinit(crypt->priv);
+                                module_put(crypt->ops->owner);
+                        }
+                        kfree(crypt);
+                        info->crypt[i] = NULL;
+                }
+        }
+}
+EXPORT_SYMBOL(lib80211_crypt_info_free);
+
+static void lib80211_crypt_deinit_entries(struct lib80211_crypt_info *info,
+					  int force)
+{
+	struct lib80211_crypt_data *entry, *next;
+	unsigned long flags;
+
+	spin_lock_irqsave(info->lock, flags);
+	list_for_each_entry_safe(entry, next, &info->crypt_deinit_list, list) {
+		if (atomic_read(&entry->refcnt) != 0 && !force)
+			continue;
+
+		list_del(&entry->list);
+
+		if (entry->ops) {
+			entry->ops->deinit(entry->priv);
+			module_put(entry->ops->owner);
+		}
+		kfree(entry);
+	}
+	spin_unlock_irqrestore(info->lock, flags);
+}
+
+/* After this, crypt_deinit_list won't accept new members */
+static void lib80211_crypt_quiescing(struct lib80211_crypt_info *info)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(info->lock, flags);
+	info->crypt_quiesced = 1;
+	spin_unlock_irqrestore(info->lock, flags);
+}
+
+static void lib80211_crypt_deinit_handler(unsigned long data)
+{
+	struct lib80211_crypt_info *info = (struct lib80211_crypt_info *)data;
+	unsigned long flags;
+
+	lib80211_crypt_deinit_entries(info, 0);
+
+	spin_lock_irqsave(info->lock, flags);
+	if (!list_empty(&info->crypt_deinit_list) && !info->crypt_quiesced) {
+		printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
+		       "deletion list\n", info->name);
+		info->crypt_deinit_timer.expires = jiffies + HZ;
+		add_timer(&info->crypt_deinit_timer);
+	}
+	spin_unlock_irqrestore(info->lock, flags);
+}
+
+void lib80211_crypt_delayed_deinit(struct lib80211_crypt_info *info,
+				    struct lib80211_crypt_data **crypt)
+{
+	struct lib80211_crypt_data *tmp;
+	unsigned long flags;
+
+	if (*crypt == NULL)
+		return;
+
+	tmp = *crypt;
+	*crypt = NULL;
+
+	/* must not run ops->deinit() while there may be pending encrypt or
+	 * decrypt operations. Use a list of delayed deinits to avoid needing
+	 * locking. */
+
+	spin_lock_irqsave(info->lock, flags);
+	if (!info->crypt_quiesced) {
+		list_add(&tmp->list, &info->crypt_deinit_list);
+		if (!timer_pending(&info->crypt_deinit_timer)) {
+			info->crypt_deinit_timer.expires = jiffies + HZ;
+			add_timer(&info->crypt_deinit_timer);
+		}
+	}
+	spin_unlock_irqrestore(info->lock, flags);
+}
+EXPORT_SYMBOL(lib80211_crypt_delayed_deinit);
+
+int lib80211_register_crypto_ops(struct lib80211_crypto_ops *ops)
+{
+	unsigned long flags;
+	struct lib80211_crypto_alg *alg;
+
+	alg = kzalloc(sizeof(*alg), GFP_KERNEL);
+	if (alg == NULL)
+		return -ENOMEM;
+
+	alg->ops = ops;
+
+	spin_lock_irqsave(&lib80211_crypto_lock, flags);
+	list_add(&alg->list, &lib80211_crypto_algs);
+	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
+
+	printk(KERN_DEBUG "lib80211_crypt: registered algorithm '%s'\n",
+	       ops->name);
+
+	return 0;
+}
+EXPORT_SYMBOL(lib80211_register_crypto_ops);
+
+int lib80211_unregister_crypto_ops(struct lib80211_crypto_ops *ops)
+{
+	struct lib80211_crypto_alg *alg;
+	unsigned long flags;
+
+	spin_lock_irqsave(&lib80211_crypto_lock, flags);
+	list_for_each_entry(alg, &lib80211_crypto_algs, list) {
+		if (alg->ops == ops)
+			goto found;
+	}
+	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
+	return -EINVAL;
+
+      found:
+	printk(KERN_DEBUG "lib80211_crypt: unregistered algorithm '%s'\n",
+	       ops->name);
+	list_del(&alg->list);
+	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
+	kfree(alg);
+	return 0;
+}
+EXPORT_SYMBOL(lib80211_unregister_crypto_ops);
+
+struct lib80211_crypto_ops *lib80211_get_crypto_ops(const char *name)
+{
+	struct lib80211_crypto_alg *alg;
+	unsigned long flags;
+
+	spin_lock_irqsave(&lib80211_crypto_lock, flags);
+	list_for_each_entry(alg, &lib80211_crypto_algs, list) {
+		if (strcmp(alg->ops->name, name) == 0)
+			goto found;
+	}
+	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
+	return NULL;
+
+      found:
+	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
+	return alg->ops;
+}
+EXPORT_SYMBOL(lib80211_get_crypto_ops);
+
+static void *lib80211_crypt_null_init(int keyidx)
+{
+	return (void *)1;
+}
+
+static void lib80211_crypt_null_deinit(void *priv)
+{
+}
+
+static struct lib80211_crypto_ops lib80211_crypt_null = {
+	.name = "NULL",
+	.init = lib80211_crypt_null_init,
+	.deinit = lib80211_crypt_null_deinit,
+	.owner = THIS_MODULE,
+};
+
+static int __init lib80211_init(void)
+{
+	pr_info(DRV_DESCRIPTION "\n");
+	return lib80211_register_crypto_ops(&lib80211_crypt_null);
+}
+
+static void __exit lib80211_exit(void)
+{
+	lib80211_unregister_crypto_ops(&lib80211_crypt_null);
+	BUG_ON(!list_empty(&lib80211_crypto_algs));
+}
+
+module_init(lib80211_init);
+module_exit(lib80211_exit);