netfilter: xtables: deconstify struct xt_action_param for matches

[safe/jmp/linux-2.6] / net / netfilter / xt_limit.c

diff --git a/net/netfilter/xt_limit.c b/net/netfilter/xt_limit.c
index c908d69..32b7a57 100644 (file)
--- a/net/netfilter/xt_limit.c
+++ b/net/netfilter/xt_limit.c
@@ -5,7 +5,9 @@
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/skbuff.h>
 #include <linux/spinlock.h>
@@ -14,6 +16,11 @@
 #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("Xtables: rate-limit match");
@@ -58,20 +65,20 @@ static DEFINE_SPINLOCK(limit_lock);
 #define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ)
 
 static bool
-limit_mt(const struct sk_buff *skb, const struct xt_match_param *par)
+limit_mt(const struct sk_buff *skb, struct xt_action_param *par)
 {
-       struct xt_rateinfo *r =
-               ((const struct xt_rateinfo *)par->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 true;
        }
@@ -92,29 +99,41 @@ user2credits(u_int32_t user)
        return (user * HZ * CREDITS_PER_JIFFY) / XT_LIMIT_SCALE;
 }
 
-static bool limit_mt_check(const struct xt_mtchk_param *par)
+static int limit_mt_check(const struct xt_mtchk_param *par)
 {
        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 false;
+               pr_info("Overflow, try lower: %u/%u\n",
+                       r->avg, r->burst);
+               return -ERANGE;
        }
 
-       /* For SMP, we only want to use one set of counters. */
-       r->master = r;
+       priv = kmalloc(sizeof(*priv), GFP_KERNEL);
+       if (priv == NULL)
+               return -ENOMEM;
+
+       /* 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. */
-               r->prev = jiffies;
-               r->credit = user2credits(r->avg * r->burst);     /* Credits full. */
+               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;
+       return 0;
+}
+
+static void limit_mt_destroy(const struct xt_mtdtor_param *par)
+{
+       const struct xt_rateinfo *info = par->matchinfo;
+
+       kfree(info->master);
 }
 
 #ifdef CONFIG_COMPAT
@@ -131,7 +150,7 @@ struct compat_xt_rateinfo {
 
 /* 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)
+static void limit_mt_compat_from_user(void *dst, const void *src)
 {
        const struct compat_xt_rateinfo *cm = src;
        struct xt_rateinfo m = {
@@ -145,7 +164,7 @@ static void limit_mt_compat_from_user(void *dst, void *src)
        memcpy(dst, &m, sizeof(m));
 }
 
-static int limit_mt_compat_to_user(void __user *dst, void *src)
+static int limit_mt_compat_to_user(void __user *dst, const void *src)
 {
        const struct xt_rateinfo *m = src;
        struct compat_xt_rateinfo cm = {
@@ -167,6 +186,7 @@ static struct xt_match limit_mt_reg __read_mostly = {
        .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),