netfilter: don't use INIT_RCU_HEAD()
[linux-2.6.git] / net / netfilter / xt_limit.c
index e8d5e7a..2773be6 100644 (file)
@@ -1,12 +1,5 @@
-/* Kernel module to control the rate
- *
- * 2 September 1999: Changed from the target RATE to the match
- *                   `limit', removed logging.  Did I mention that
- *                   Alexey is a fucking genius?
- *                   Rusty Russell (rusty@rustcorp.com.au).  */
-
-/* (C) 1999 Jérôme de Vivie <devivie@info.enserb.u-bordeaux.fr>
- * (C) 1999 Hervé Eychenne <eychenne@info.enserb.u-bordeaux.fr>
+/* (C) 1999 Jérôme de Vivie <devivie@info.enserb.u-bordeaux.fr>
+ * (C) 1999 Hervé Eychenne <eychenne@info.enserb.u-bordeaux.fr>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
 #include <linux/netfilter/x_tables.h>
 #include <linux/netfilter/xt_limit.h>
 
+struct xt_limit_priv {
+       unsigned long prev;
+       uint32_t credit;
+};
+
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Herve Eychenne <rv@wallfire.org>");
-MODULE_DESCRIPTION("iptables rate limit match");
+MODULE_DESCRIPTION("Xtables: rate-limit match");
 MODULE_ALIAS("ipt_limit");
 MODULE_ALIAS("ip6t_limit");
 
@@ -64,33 +62,27 @@ static DEFINE_SPINLOCK(limit_lock);
 
 #define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ)
 
-static int
-ipt_limit_match(const struct sk_buff *skb,
-               const struct net_device *in,
-               const struct net_device *out,
-               const struct xt_match *match,
-               const void *matchinfo,
-               int offset,
-               unsigned int protoff,
-               int *hotdrop)
+static bool
+limit_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 {
-       struct xt_rateinfo *r = ((struct xt_rateinfo *)matchinfo)->master;
+       const struct xt_rateinfo *r = par->matchinfo;
+       struct xt_limit_priv *priv = r->master;
        unsigned long now = jiffies;
 
        spin_lock_bh(&limit_lock);
-       r->credit += (now - xchg(&r->prev, now)) * CREDITS_PER_JIFFY;
-       if (r->credit > r->credit_cap)
-               r->credit = r->credit_cap;
+       priv->credit += (now - xchg(&priv->prev, now)) * CREDITS_PER_JIFFY;
+       if (priv->credit > r->credit_cap)
+               priv->credit = r->credit_cap;
 
-       if (r->credit >= r->cost) {
+       if (priv->credit >= r->cost) {
                /* We're not limited. */
-               r->credit -= r->cost;
+               priv->credit -= r->cost;
                spin_unlock_bh(&limit_lock);
-               return 1;
+               return true;
        }
 
-               spin_unlock_bh(&limit_lock);
-       return 0;
+       spin_unlock_bh(&limit_lock);
+       return false;
 }
 
 /* Precision saver. */
@@ -105,65 +97,112 @@ user2credits(u_int32_t user)
        return (user * HZ * CREDITS_PER_JIFFY) / XT_LIMIT_SCALE;
 }
 
-static int
-ipt_limit_checkentry(const char *tablename,
-                    const void *inf,
-                    const struct xt_match *match,
-                    void *matchinfo,
-                    unsigned int matchsize,
-                    unsigned int hook_mask)
+static bool limit_mt_check(const struct xt_mtchk_param *par)
 {
-       struct xt_rateinfo *r = matchinfo;
+       struct xt_rateinfo *r = par->matchinfo;
+       struct xt_limit_priv *priv;
 
        /* Check for overflow. */
        if (r->burst == 0
            || user2credits(r->avg * r->burst) < user2credits(r->avg)) {
                printk("Overflow in xt_limit, try lower: %u/%u\n",
                       r->avg, r->burst);
-               return 0;
+               return false;
        }
 
-       /* User avg in seconds * XT_LIMIT_SCALE: convert to jiffies *
-          128. */
-       r->prev = jiffies;
-       r->credit = user2credits(r->avg * r->burst);     /* Credits full. */
-       r->credit_cap = user2credits(r->avg * r->burst); /* Credits full. */
-       r->cost = user2credits(r->avg);
+       priv = kmalloc(sizeof(*priv), GFP_KERNEL);
+       if (priv == NULL)
+               return false;
+
+       /* For SMP, we only want to use one set of state. */
+       r->master = priv;
+       if (r->cost == 0) {
+               /* User avg in seconds * XT_LIMIT_SCALE: convert to jiffies *
+                  128. */
+               priv->prev = jiffies;
+               priv->credit = user2credits(r->avg * r->burst); /* Credits full. */
+               r->credit_cap = user2credits(r->avg * r->burst); /* Credits full. */
+               r->cost = user2credits(r->avg);
+       }
+       return true;
+}
+
+static void limit_mt_destroy(const struct xt_mtdtor_param *par)
+{
+       const struct xt_rateinfo *info = par->matchinfo;
+
+       kfree(info->master);
+}
+
+#ifdef CONFIG_COMPAT
+struct compat_xt_rateinfo {
+       u_int32_t avg;
+       u_int32_t burst;
+
+       compat_ulong_t prev;
+       u_int32_t credit;
+       u_int32_t credit_cap, cost;
 
-       /* For SMP, we only want to use one set of counters. */
-       r->master = r;
+       u_int32_t master;
+};
 
-       return 1;
+/* To keep the full "prev" timestamp, the upper 32 bits are stored in the
+ * master pointer, which does not need to be preserved. */
+static void limit_mt_compat_from_user(void *dst, void *src)
+{
+       const struct compat_xt_rateinfo *cm = src;
+       struct xt_rateinfo m = {
+               .avg            = cm->avg,
+               .burst          = cm->burst,
+               .prev           = cm->prev | (unsigned long)cm->master << 32,
+               .credit         = cm->credit,
+               .credit_cap     = cm->credit_cap,
+               .cost           = cm->cost,
+       };
+       memcpy(dst, &m, sizeof(m));
 }
 
-static struct xt_match xt_limit_match[] = {
-       {
-               .name           = "limit",
-               .family         = AF_INET,
-               .checkentry     = ipt_limit_checkentry,
-               .match          = ipt_limit_match,
-               .matchsize      = sizeof(struct xt_rateinfo),
-               .me             = THIS_MODULE,
-       },
-       {
-               .name           = "limit",
-               .family         = AF_INET6,
-               .checkentry     = ipt_limit_checkentry,
-               .match          = ipt_limit_match,
-               .matchsize      = sizeof(struct xt_rateinfo),
-               .me             = THIS_MODULE,
-       },
+static int limit_mt_compat_to_user(void __user *dst, void *src)
+{
+       const struct xt_rateinfo *m = src;
+       struct compat_xt_rateinfo cm = {
+               .avg            = m->avg,
+               .burst          = m->burst,
+               .prev           = m->prev,
+               .credit         = m->credit,
+               .credit_cap     = m->credit_cap,
+               .cost           = m->cost,
+               .master         = m->prev >> 32,
+       };
+       return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0;
+}
+#endif /* CONFIG_COMPAT */
+
+static struct xt_match limit_mt_reg __read_mostly = {
+       .name             = "limit",
+       .revision         = 0,
+       .family           = NFPROTO_UNSPEC,
+       .match            = limit_mt,
+       .checkentry       = limit_mt_check,
+       .destroy          = limit_mt_destroy,
+       .matchsize        = sizeof(struct xt_rateinfo),
+#ifdef CONFIG_COMPAT
+       .compatsize       = sizeof(struct compat_xt_rateinfo),
+       .compat_from_user = limit_mt_compat_from_user,
+       .compat_to_user   = limit_mt_compat_to_user,
+#endif
+       .me               = THIS_MODULE,
 };
 
-static int __init xt_limit_init(void)
+static int __init limit_mt_init(void)
 {
-       return xt_register_matches(xt_limit_match, ARRAY_SIZE(xt_limit_match));
+       return xt_register_match(&limit_mt_reg);
 }
 
-static void __exit xt_limit_fini(void)
+static void __exit limit_mt_exit(void)
 {
-       xt_unregister_matches(xt_limit_match, ARRAY_SIZE(xt_limit_match));
+       xt_unregister_match(&limit_mt_reg);
 }
 
-module_init(xt_limit_init);
-module_exit(xt_limit_fini);
+module_init(limit_mt_init);
+module_exit(limit_mt_exit);