[NETFILTER]: x_tables: add port of hashlimit match for IPv4 and IPv6

Signed-off-by: Patrick McHardy <kaber@trash.net>

5 files changed, 290 insertions, 251 deletions

diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index 4ac5b5c4678d..bc298a3f236f 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -326,20 +326,6 @@ config IP_NF_MATCH_ADDRTYPE
           If you want to compile it as a module, say M here and read
           <file:Documentation/modules.txt>.  If unsure, say `N'.
 
-config IP_NF_MATCH_HASHLIMIT
-        tristate  'hashlimit match support'
-        depends on IP_NF_IPTABLES
-        help
-          This option adds a new iptables `hashlimit' match.  
-
-          As opposed to `limit', this match dynamically creates a hash table
-          of limit buckets, based on your selection of source/destination
-          ip addresses and/or ports.
-
-          It enables you to express policies like `10kpps for any given
-          destination IP' or `500pps from any given source IP'  with a single
-          IPtables rule.
-
 # `filter', generic and specific targets
 config IP_NF_FILTER
         tristate "Packet filtering"
diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile
index 4ce20ebc4d6c..21359d83f0c7 100644
--- a/net/ipv4/netfilter/Makefile
+++ b/net/ipv4/netfilter/Makefile
@@ -53,7 +53,6 @@ obj-$(CONFIG_IP_NF_NAT) += iptable_nat.o
 obj-$(CONFIG_IP_NF_RAW) += iptable_raw.o
 
 # matches
-obj-$(CONFIG_IP_NF_MATCH_HASHLIMIT) += ipt_hashlimit.o
 obj-$(CONFIG_IP_NF_MATCH_IPRANGE) += ipt_iprange.o
 obj-$(CONFIG_IP_NF_MATCH_OWNER) += ipt_owner.o
 obj-$(CONFIG_IP_NF_MATCH_TOS) += ipt_tos.o
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index f619c6527266..7e6125467c12 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -464,5 +464,19 @@ config NETFILTER_XT_MATCH_TCPMSS
 
           To compile it as a module, choose M here.  If unsure, say N.
 
+config NETFILTER_XT_MATCH_HASHLIMIT
+        tristate '"hashlimit" match support'
+        depends on NETFILTER_XTABLES
+        help
+          This option adds a `hashlimit' match.
+
+          As opposed to `limit', this match dynamically creates a hash table
+          of limit buckets, based on your selection of source/destination
+          addresses and/or ports.
+
+          It enables you to express policies like `10kpps for any given
+          destination address' or `500pps from any given source address'
+          with a single rule.
+
 endmenu
 
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 84d529ded952..f85811bfcfe5 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -59,3 +59,4 @@ obj-$(CONFIG_NETFILTER_XT_MATCH_STATISTIC) += xt_statistic.o
 obj-$(CONFIG_NETFILTER_XT_MATCH_STRING) += xt_string.o
 obj-$(CONFIG_NETFILTER_XT_MATCH_TCPMSS) += xt_tcpmss.o
 obj-$(CONFIG_NETFILTER_XT_MATCH_PHYSDEV) += xt_physdev.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_HASHLIMIT) += xt_hashlimit.o
diff --git a/net/ipv4/netfilter/ipt_hashlimit.c b/net/netfilter/xt_hashlimit.c
index 33ccdbf8e794..46de566d3721 100644
--- a/net/ipv4/netfilter/ipt_hashlimit.c
+++ b/net/netfilter/xt_hashlimit.c
@@ -6,23 +6,8 @@
  * $Id: ipt_hashlimit.c 3244 2004-10-20 16:24:29Z laforge@netfilter.org $
  *
  * Development of this code was funded by Astaro AG, http://www.astaro.com/
- *
- * based on ipt_limit.c by:
- * Jérôme de Vivie      <devivie@info.enserb.u-bordeaux.fr>
- * Hervé Eychenne       <eychenne@info.enserb.u-bordeaux.fr>
- * Rusty Russell        <rusty@rustcorp.com.au>
- *
- * The general idea is to create a hash table for every dstip and have a
- * seperate limit counter per tuple.  This way you can do something like 'limit
- * the number of syn packets for each of my internal addresses.
- *
- * Ideally this would just be implemented as a general 'hash' match, which would
- * allow us to attach any iptables target to it's hash buckets.  But this is
- * not possible in the current iptables architecture.  As always, pkttables for
- * 2.7.x will help ;)
  */
 #include <linux/module.h>
-#include <linux/skbuff.h>
 #include <linux/spinlock.h>
 #include <linux/random.h>
 #include <linux/jhash.h>
@@ -31,28 +16,40 @@
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/list.h>
+#include <linux/skbuff.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
 
+#include <linux/netfilter/x_tables.h>
 #include <linux/netfilter_ipv4/ip_tables.h>
-#include <linux/netfilter_ipv4/ipt_hashlimit.h>
-
-/* FIXME: this is just for IP_NF_ASSERRT */
-#include <linux/netfilter_ipv4/ip_conntrack.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+#include <linux/netfilter/xt_hashlimit.h>
 #include <linux/mutex.h>
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
 MODULE_DESCRIPTION("iptables match for limiting per hash-bucket");
+MODULE_ALIAS("ipt_hashlimit");
+MODULE_ALIAS("ip6t_hashlimit");
 
 /* need to declare this at the top */
-static struct proc_dir_entry *hashlimit_procdir;
+static struct proc_dir_entry *hashlimit_procdir4;
+static struct proc_dir_entry *hashlimit_procdir6;
 static struct file_operations dl_file_ops;
 
 /* hash table crap */
-
 struct dsthash_dst {
-        __be32 src_ip;
-        __be32 dst_ip;
-        /* ports have to be consecutive !!! */
+        union {
+                struct {
+                        __be32 src;
+                        __be32 dst;
+                } ip;
+                struct {
+                        __be32 src[4];
+                        __be32 dst[4];
+                } ip6;
+        } addr;
         __be16 src_port;
         __be16 dst_port;
 };
@@ -71,9 +68,10 @@ struct dsthash_ent {
         } rateinfo;
 };
 
-struct ipt_hashlimit_htable {
+struct xt_hashlimit_htable {
         struct hlist_node node;         /* global list of all htables */
         atomic_t use;
+        int family;
 
         struct hashlimit_cfg cfg;       /* config */
 
@@ -81,8 +79,8 @@ struct ipt_hashlimit_htable {
         spinlock_t lock;                /* lock for list_head */
         u_int32_t rnd;                  /* random seed for hash */
         int rnd_initialized;
+        unsigned int count;             /* number entries in table */
         struct timer_list timer;        /* timer for gc */
-        atomic_t count;                 /* number entries in table */
 
         /* seq_file stuff */
         struct proc_dir_entry *pde;
@@ -97,41 +95,33 @@ static kmem_cache_t *hashlimit_cachep __read_mostly;
 
 static inline int dst_cmp(const struct dsthash_ent *ent, struct dsthash_dst *b)
 {
-        return (ent->dst.dst_ip == b->dst_ip 
-                && ent->dst.dst_port == b->dst_port
-                && ent->dst.src_port == b->src_port
-                && ent->dst.src_ip == b->src_ip);
+        return !memcmp(&ent->dst, b, sizeof(ent->dst));
 }
 
-static inline u_int32_t
-hash_dst(const struct ipt_hashlimit_htable *ht, const struct dsthash_dst *dst)
+static u_int32_t
+hash_dst(const struct xt_hashlimit_htable *ht, const struct dsthash_dst *dst)
 {
-        return (jhash_3words((__force u32)dst->dst_ip,
-                            ((__force u32)dst->dst_port<<16 |
-                             (__force u32)dst->src_port),
-                             (__force u32)dst->src_ip, ht->rnd) % ht->cfg.size);
+        return jhash(dst, sizeof(*dst), ht->rnd) % ht->cfg.size;
 }
 
-static inline struct dsthash_ent *
-__dsthash_find(const struct ipt_hashlimit_htable *ht, struct dsthash_dst *dst)
+static struct dsthash_ent *
+dsthash_find(const struct xt_hashlimit_htable *ht, struct dsthash_dst *dst)
 {
         struct dsthash_ent *ent;
         struct hlist_node *pos;
         u_int32_t hash = hash_dst(ht, dst);
 
-        if (!hlist_empty(&ht->hash[hash]))
-                hlist_for_each_entry(ent, pos, &ht->hash[hash], node) {
-                        if (dst_cmp(ent, dst)) {
+        if (!hlist_empty(&ht->hash[hash])) {
+                hlist_for_each_entry(ent, pos, &ht->hash[hash], node)
+                        if (dst_cmp(ent, dst))
                                 return ent;
-                        }
-                }
-        
+        }
         return NULL;
 }
 
 /* allocate dsthash_ent, initialize dst, put in htable and lock it */
 static struct dsthash_ent *
-__dsthash_alloc_init(struct ipt_hashlimit_htable *ht, struct dsthash_dst *dst)
+dsthash_alloc_init(struct xt_hashlimit_htable *ht, struct dsthash_dst *dst)
 {
         struct dsthash_ent *ent;
 
@@ -142,12 +132,11 @@ __dsthash_alloc_init(struct ipt_hashlimit_htable *ht, struct dsthash_dst *dst)
                 ht->rnd_initialized = 1;
         }
 
-        if (ht->cfg.max &&
-            atomic_read(&ht->count) >= ht->cfg.max) {
+        if (ht->cfg.max && ht->count >= ht->cfg.max) {
                 /* FIXME: do something. question is what.. */
                 if (net_ratelimit())
-                        printk(KERN_WARNING 
-                                "ipt_hashlimit: max count of %u reached\n", 
+                        printk(KERN_WARNING
+                                "xt_hashlimit: max count of %u reached\n",
                                 ht->cfg.max);
                 return NULL;
         }
@@ -155,53 +144,47 @@ __dsthash_alloc_init(struct ipt_hashlimit_htable *ht, struct dsthash_dst *dst)
         ent = kmem_cache_alloc(hashlimit_cachep, GFP_ATOMIC);
         if (!ent) {
                 if (net_ratelimit())
-                        printk(KERN_ERR 
-                                "ipt_hashlimit: can't allocate dsthash_ent\n");
+                        printk(KERN_ERR
+                                "xt_hashlimit: can't allocate dsthash_ent\n");
                 return NULL;
         }
-
-        atomic_inc(&ht->count);
-
-        ent->dst.dst_ip = dst->dst_ip;
-        ent->dst.dst_port = dst->dst_port;
-        ent->dst.src_ip = dst->src_ip;
-        ent->dst.src_port = dst->src_port;
+        memcpy(&ent->dst, dst, sizeof(ent->dst));
 
         hlist_add_head(&ent->node, &ht->hash[hash_dst(ht, dst)]);
-
+        ht->count++;
         return ent;
 }
 
-static inline void 
-__dsthash_free(struct ipt_hashlimit_htable *ht, struct dsthash_ent *ent)
+static inline void
+dsthash_free(struct xt_hashlimit_htable *ht, struct dsthash_ent *ent)
 {
         hlist_del(&ent->node);
         kmem_cache_free(hashlimit_cachep, ent);
-        atomic_dec(&ht->count);
+        ht->count--;
 }
 static void htable_gc(unsigned long htlong);
 
-static int htable_create(struct ipt_hashlimit_info *minfo)
+static int htable_create(struct xt_hashlimit_info *minfo, int family)
 {
-        int i;
+        struct xt_hashlimit_htable *hinfo;
         unsigned int size;
-        struct ipt_hashlimit_htable *hinfo;
+        unsigned int i;
 
         if (minfo->cfg.size)
                 size = minfo->cfg.size;
         else {
-                size = (((num_physpages << PAGE_SHIFT) / 16384)
-                         / sizeof(struct list_head));
+                size = ((num_physpages << PAGE_SHIFT) / 16384) /
+                       sizeof(struct list_head);
                 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
                         size = 8192;
                 if (size < 16)
                         size = 16;
         }
         /* FIXME: don't use vmalloc() here or anywhere else -HW */
-        hinfo = vmalloc(sizeof(struct ipt_hashlimit_htable)
-                        + (sizeof(struct list_head) * size));
+        hinfo = vmalloc(sizeof(struct xt_hashlimit_htable) +
+                        sizeof(struct list_head) * size);
         if (!hinfo) {
-                printk(KERN_ERR "ipt_hashlimit: Unable to create hashtable\n");
+                printk(KERN_ERR "xt_hashlimit: unable to create hashtable\n");
                 return -1;
         }
         minfo->hinfo = hinfo;
@@ -217,11 +200,14 @@ static int htable_create(struct ipt_hashlimit_info *minfo)
         for (i = 0; i < hinfo->cfg.size; i++)
                 INIT_HLIST_HEAD(&hinfo->hash[i]);
 
-        atomic_set(&hinfo->count, 0);
         atomic_set(&hinfo->use, 1);
+        hinfo->count = 0;
+        hinfo->family = family;
         hinfo->rnd_initialized = 0;
         spin_lock_init(&hinfo->lock);
-        hinfo->pde = create_proc_entry(minfo->name, 0, hashlimit_procdir);
+        hinfo->pde = create_proc_entry(minfo->name, 0,
+                                       family == AF_INET ? hashlimit_procdir4 :
+                                                           hashlimit_procdir6);
         if (!hinfo->pde) {
                 vfree(hinfo);
                 return -1;
@@ -242,23 +228,21 @@ static int htable_create(struct ipt_hashlimit_info *minfo)
         return 0;
 }
 
-static int select_all(struct ipt_hashlimit_htable *ht, struct dsthash_ent *he)
+static int select_all(struct xt_hashlimit_htable *ht, struct dsthash_ent *he)
 {
         return 1;
 }
 
-static int select_gc(struct ipt_hashlimit_htable *ht, struct dsthash_ent *he)
+static int select_gc(struct xt_hashlimit_htable *ht, struct dsthash_ent *he)
 {
         return (jiffies >= he->expires);
 }
 
-static void htable_selective_cleanup(struct ipt_hashlimit_htable *ht,
-                                int (*select)(struct ipt_hashlimit_htable *ht, 
+static void htable_selective_cleanup(struct xt_hashlimit_htable *ht,
+                                int (*select)(struct xt_hashlimit_htable *ht,
                                               struct dsthash_ent *he))
 {
-        int i;
-
-        IP_NF_ASSERT(ht->cfg.size && ht->cfg.max);
+        unsigned int i;
 
         /* lock hash table and iterate over it */
         spin_lock_bh(&ht->lock);
@@ -267,7 +251,7 @@ static void htable_selective_cleanup(struct ipt_hashlimit_htable *ht,
                 struct hlist_node *pos, *n;
                 hlist_for_each_entry_safe(dh, pos, n, &ht->hash[i], node) {
                         if ((*select)(ht, dh))
-                                __dsthash_free(ht, dh);
+                                dsthash_free(ht, dh);
                 }
         }
         spin_unlock_bh(&ht->lock);
@@ -276,7 +260,7 @@ static void htable_selective_cleanup(struct ipt_hashlimit_htable *ht,
 /* hash table garbage collector, run by timer */
 static void htable_gc(unsigned long htlong)
 {
-        struct ipt_hashlimit_htable *ht = (struct ipt_hashlimit_htable *)htlong;
+        struct xt_hashlimit_htable *ht = (struct xt_hashlimit_htable *)htlong;
 
         htable_selective_cleanup(ht, select_gc);
 
@@ -285,38 +269,39 @@ static void htable_gc(unsigned long htlong)
         add_timer(&ht->timer);
 }
 
-static void htable_destroy(struct ipt_hashlimit_htable *hinfo)
+static void htable_destroy(struct xt_hashlimit_htable *hinfo)
 {
         /* remove timer, if it is pending */
         if (timer_pending(&hinfo->timer))
                 del_timer(&hinfo->timer);
 
         /* remove proc entry */
-        remove_proc_entry(hinfo->pde->name, hashlimit_procdir);
-
+        remove_proc_entry(hinfo->pde->name,
+                          hinfo->family == AF_INET ? hashlimit_procdir4 :
+                                                     hashlimit_procdir6);
         htable_selective_cleanup(hinfo, select_all);
         vfree(hinfo);
 }
 
-static struct ipt_hashlimit_htable *htable_find_get(char *name)
+static struct xt_hashlimit_htable *htable_find_get(char *name, int family)
 {
-        struct ipt_hashlimit_htable *hinfo;
+        struct xt_hashlimit_htable *hinfo;
         struct hlist_node *pos;
 
         spin_lock_bh(&hashlimit_lock);
         hlist_for_each_entry(hinfo, pos, &hashlimit_htables, node) {
-                if (!strcmp(name, hinfo->pde->name)) {
+                if (!strcmp(name, hinfo->pde->name) &&
+                    hinfo->family == family) {
                         atomic_inc(&hinfo->use);
                         spin_unlock_bh(&hashlimit_lock);
                         return hinfo;
                 }
         }
         spin_unlock_bh(&hashlimit_lock);
-
         return NULL;
 }
 
-static void htable_put(struct ipt_hashlimit_htable *hinfo)
+static void htable_put(struct xt_hashlimit_htable *hinfo)
 {
         if (atomic_dec_and_test(&hinfo->use)) {
                 spin_lock_bh(&hashlimit_lock);
@@ -326,7 +311,6 @@ static void htable_put(struct ipt_hashlimit_htable *hinfo)
         }
 }
 
-
 /* The algorithm used is the Simple Token Bucket Filter (TBF)
  * see net/sched/sch_tbf.c in the linux source tree
  */
@@ -370,17 +354,82 @@ user2credits(u_int32_t user)
         /* If multiplying would overflow... */
         if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY))
                 /* Divide first. */
-                return (user / IPT_HASHLIMIT_SCALE) * HZ * CREDITS_PER_JIFFY;
+                return (user / XT_HASHLIMIT_SCALE) * HZ * CREDITS_PER_JIFFY;
 
-        return (user * HZ * CREDITS_PER_JIFFY) / IPT_HASHLIMIT_SCALE;
+        return (user * HZ * CREDITS_PER_JIFFY) / XT_HASHLIMIT_SCALE;
 }
 
 static inline void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now)
 {
-        dh->rateinfo.credit += (now - xchg(&dh->rateinfo.prev, now)) 
-                                        * CREDITS_PER_JIFFY;
+        dh->rateinfo.credit += (now - dh->rateinfo.prev) * CREDITS_PER_JIFFY;
         if (dh->rateinfo.credit > dh->rateinfo.credit_cap)
                 dh->rateinfo.credit = dh->rateinfo.credit_cap;
+        dh->rateinfo.prev = now;
+}
+
+static int
+hashlimit_init_dst(struct xt_hashlimit_htable *hinfo, struct dsthash_dst *dst,
+                   const struct sk_buff *skb, unsigned int protoff)
+{
+        __be16 _ports[2], *ports;
+        int nexthdr;
+
+        memset(dst, 0, sizeof(*dst));
+
+        switch (hinfo->family) {
+        case AF_INET:
+                if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP)
+                        dst->addr.ip.dst = skb->nh.iph->daddr;
+                if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP)
+                        dst->addr.ip.src = skb->nh.iph->saddr;
+
+                if (!(hinfo->cfg.mode &
+                      (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT)))
+                        return 0;
+                nexthdr = skb->nh.iph->protocol;
+                break;
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+        case AF_INET6:
+                if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP)
+                        memcpy(&dst->addr.ip6.dst, &skb->nh.ipv6h->daddr,
+                               sizeof(dst->addr.ip6.dst));
+                if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP)
+                        memcpy(&dst->addr.ip6.src, &skb->nh.ipv6h->saddr,
+                               sizeof(dst->addr.ip6.src));
+
+                if (!(hinfo->cfg.mode &
+                      (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT)))
+                        return 0;
+                nexthdr = ipv6_find_hdr(skb, &protoff, -1, NULL);
+                if (nexthdr < 0)
+                        return -1;
+                break;
+#endif
+        default:
+                BUG();
+                return 0;
+        }
+
+        switch (nexthdr) {
+        case IPPROTO_TCP:
+        case IPPROTO_UDP:
+        case IPPROTO_SCTP:
+        case IPPROTO_DCCP:
+                ports = skb_header_pointer(skb, protoff, sizeof(_ports),
+                                           &_ports);
+                break;
+        default:
+                _ports[0] = _ports[1] = 0;
+                ports = _ports;
+                break;
+        }
+        if (!ports)
+                return -1;
+        if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SPT)
+                dst->src_port = ports[0];
+        if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DPT)
+                dst->dst_port = ports[1];
+        return 0;
 }
 
 static int
@@ -393,68 +442,31 @@ hashlimit_match(const struct sk_buff *skb,
                 unsigned int protoff,
                 int *hotdrop)
 {
-        struct ipt_hashlimit_info *r = 
-                ((struct ipt_hashlimit_info *)matchinfo)->u.master;
-        struct ipt_hashlimit_htable *hinfo = r->hinfo;
+        struct xt_hashlimit_info *r =
+                ((struct xt_hashlimit_info *)matchinfo)->u.master;
+        struct xt_hashlimit_htable *hinfo = r->hinfo;
         unsigned long now = jiffies;
         struct dsthash_ent *dh;
         struct dsthash_dst dst;
 
-        /* build 'dst' according to hinfo->cfg and current packet */
-        memset(&dst, 0, sizeof(dst));
-        if (hinfo->cfg.mode & IPT_HASHLIMIT_HASH_DIP)
-                dst.dst_ip = skb->nh.iph->daddr;
-        if (hinfo->cfg.mode & IPT_HASHLIMIT_HASH_SIP)
-                dst.src_ip = skb->nh.iph->saddr;
-        if (hinfo->cfg.mode & IPT_HASHLIMIT_HASH_DPT
-            ||hinfo->cfg.mode & IPT_HASHLIMIT_HASH_SPT) {
-                __be16 _ports[2], *ports;
-
-                switch (skb->nh.iph->protocol) {
-                case IPPROTO_TCP:
-                case IPPROTO_UDP:
-                case IPPROTO_SCTP:
-                case IPPROTO_DCCP:
-                        ports = skb_header_pointer(skb, skb->nh.iph->ihl*4,
-                                                   sizeof(_ports), &_ports);
-                        break;
-                default:
-                        _ports[0] = _ports[1] = 0;
-                        ports = _ports;
-                        break;
-                }
-                if (!ports) {
-                        /* We've been asked to examine this packet, and we
-                          can't.  Hence, no choice but to drop. */
-                        *hotdrop = 1;
-                        return 0;
-                }
-                if (hinfo->cfg.mode & IPT_HASHLIMIT_HASH_SPT)
-                        dst.src_port = ports[0];
-                if (hinfo->cfg.mode & IPT_HASHLIMIT_HASH_DPT)
-                        dst.dst_port = ports[1];
-        } 
+        if (hashlimit_init_dst(hinfo, &dst, skb, protoff) < 0)
+                goto hotdrop;
 
         spin_lock_bh(&hinfo->lock);
-        dh = __dsthash_find(hinfo, &dst);
+        dh = dsthash_find(hinfo, &dst);
         if (!dh) {
-                dh = __dsthash_alloc_init(hinfo, &dst);
-
+                dh = dsthash_alloc_init(hinfo, &dst);
                 if (!dh) {
-                        /* enomem... don't match == DROP */
-                        if (net_ratelimit())
-                                printk(KERN_ERR "%s: ENOMEM\n", __FUNCTION__);
                         spin_unlock_bh(&hinfo->lock);
-                        return 0;
+                        goto hotdrop;
                 }
 
                 dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire);
-
                 dh->rateinfo.prev = jiffies;
-                dh->rateinfo.credit = user2credits(hinfo->cfg.avg * 
-                                                        hinfo->cfg.burst);
-                dh->rateinfo.credit_cap = user2credits(hinfo->cfg.avg * 
-                                                        hinfo->cfg.burst);
+                dh->rateinfo.credit = user2credits(hinfo->cfg.avg *
+                                                   hinfo->cfg.burst);
+                dh->rateinfo.credit_cap = user2credits(hinfo->cfg.avg *
+                                                       hinfo->cfg.burst);
                 dh->rateinfo.cost = user2credits(hinfo->cfg.avg);
         } else {
                 /* update expiration timeout */
@@ -473,6 +485,10 @@ hashlimit_match(const struct sk_buff *skb,
 
         /* default case: we're overlimit, thus don't match */
         return 0;
+
+hotdrop:
+        *hotdrop = 1;
+        return 0;
 }
 
 static int
@@ -482,42 +498,37 @@ hashlimit_checkentry(const char *tablename,
                      void *matchinfo,
                      unsigned int hook_mask)
 {
-        struct ipt_hashlimit_info *r = matchinfo;
+        struct xt_hashlimit_info *r = matchinfo;
 
         /* Check for overflow. */
-        if (r->cfg.burst == 0
-            || user2credits(r->cfg.avg * r->cfg.burst) < 
-                                        user2credits(r->cfg.avg)) {
-                printk(KERN_ERR "ipt_hashlimit: Overflow, try lower: %u/%u\n",
+        if (r->cfg.burst == 0 ||
+            user2credits(r->cfg.avg * r->cfg.burst) < user2credits(r->cfg.avg)) {
+                printk(KERN_ERR "xt_hashlimit: overflow, try lower: %u/%u\n",
                        r->cfg.avg, r->cfg.burst);
                 return 0;
         }
-
-        if (r->cfg.mode == 0 
-            || r->cfg.mode > (IPT_HASHLIMIT_HASH_DPT
-                          |IPT_HASHLIMIT_HASH_DIP
-                          |IPT_HASHLIMIT_HASH_SIP
-                          |IPT_HASHLIMIT_HASH_SPT))
+        if (r->cfg.mode == 0 ||
+            r->cfg.mode > (XT_HASHLIMIT_HASH_DPT |
+                           XT_HASHLIMIT_HASH_DIP |
+                           XT_HASHLIMIT_HASH_SIP |
+                           XT_HASHLIMIT_HASH_SPT))
                 return 0;
-
         if (!r->cfg.gc_interval)
                 return 0;
-        
         if (!r->cfg.expire)
                 return 0;
-
         if (r->name[sizeof(r->name) - 1] != '\0')
                 return 0;
 
         /* This is the best we've got: We cannot release and re-grab lock,
-         * since checkentry() is called before ip_tables.c grabs ipt_mutex.  
-         * We also cannot grab the hashtable spinlock, since htable_create will 
+         * since checkentry() is called before x_tables.c grabs xt_mutex.
+         * We also cannot grab the hashtable spinlock, since htable_create will
          * call vmalloc, and that can sleep.  And we cannot just re-search
          * the list of htable's in htable_create(), since then we would
          * create duplicate proc files. -HW */
         mutex_lock(&hlimit_mutex);
-        r->hinfo = htable_find_get(r->name);
-        if (!r->hinfo && (htable_create(r) != 0)) {
+        r->hinfo = htable_find_get(r->name, match->family);
+        if (!r->hinfo && htable_create(r, match->family) != 0) {
                 mutex_unlock(&hlimit_mutex);
                 return 0;
         }
@@ -525,20 +536,19 @@ hashlimit_checkentry(const char *tablename,
 
         /* Ugly hack: For SMP, we only want to use one set */
         r->u.master = r;
-
         return 1;
 }
 
 static void
 hashlimit_destroy(const struct xt_match *match, void *matchinfo)
 {
-        struct ipt_hashlimit_info *r = matchinfo;
+        struct xt_hashlimit_info *r = matchinfo;
 
         htable_put(r->hinfo);
 }
 
 #ifdef CONFIG_COMPAT
-struct compat_ipt_hashlimit_info {
+struct compat_xt_hashlimit_info {
         char name[IFNAMSIZ];
         struct hashlimit_cfg cfg;
         compat_uptr_t hinfo;
@@ -547,40 +557,56 @@ struct compat_ipt_hashlimit_info {
 
 static void compat_from_user(void *dst, void *src)
 {
-        int off = offsetof(struct compat_ipt_hashlimit_info, hinfo);
+        int off = offsetof(struct compat_xt_hashlimit_info, hinfo);
 
         memcpy(dst, src, off);
-        memset(dst + off, 0, sizeof(struct compat_ipt_hashlimit_info) - off);
+        memset(dst + off, 0, sizeof(struct compat_xt_hashlimit_info) - off);
 }
 
 static int compat_to_user(void __user *dst, void *src)
 {
-        int off = offsetof(struct compat_ipt_hashlimit_info, hinfo);
+        int off = offsetof(struct compat_xt_hashlimit_info, hinfo);
 
         return copy_to_user(dst, src, off) ? -EFAULT : 0;
 }
 #endif
 
-static struct ipt_match ipt_hashlimit = {
-        .name           = "hashlimit",
-        .match          = hashlimit_match,
-        .matchsize      = sizeof(struct ipt_hashlimit_info),
+static struct xt_match xt_hashlimit[] = {
+        {
+                .name           = "hashlimit",
+                .family         = AF_INET,
+                .match          = hashlimit_match,
+                .matchsize      = sizeof(struct xt_hashlimit_info),
+#ifdef CONFIG_COMPAT
+                .compatsize     = sizeof(struct compat_xt_hashlimit_info),
+                .compat_from_user = compat_from_user,
+                .compat_to_user = compat_to_user,
+#endif
+                .checkentry     = hashlimit_checkentry,
+                .destroy        = hashlimit_destroy,
+                .me             = THIS_MODULE
+        },
+        {
+                .name           = "hashlimit",
+                .family         = AF_INET6,
+                .match          = hashlimit_match,
+                .matchsize      = sizeof(struct xt_hashlimit_info),
 #ifdef CONFIG_COMPAT
-        .compatsize     = sizeof(struct compat_ipt_hashlimit_info),
-        .compat_from_user = compat_from_user,
-        .compat_to_user = compat_to_user,
+                .compatsize     = sizeof(struct compat_xt_hashlimit_info),
+                .compat_from_user = compat_from_user,
+                .compat_to_user = compat_to_user,
 #endif
-        .checkentry     = hashlimit_checkentry,
-        .destroy        = hashlimit_destroy,
-        .me             = THIS_MODULE
+                .checkentry     = hashlimit_checkentry,
+                .destroy        = hashlimit_destroy,
+                .me             = THIS_MODULE
+        },
 };
 
 /* PROC stuff */
-
 static void *dl_seq_start(struct seq_file *s, loff_t *pos)
 {
         struct proc_dir_entry *pde = s->private;
-        struct ipt_hashlimit_htable *htable = pde->data;
+        struct xt_hashlimit_htable *htable = pde->data;
         unsigned int *bucket;
 
         spin_lock_bh(&htable->lock);
@@ -598,7 +624,7 @@ static void *dl_seq_start(struct seq_file *s, loff_t *pos)
 static void *dl_seq_next(struct seq_file *s, void *v, loff_t *pos)
 {
         struct proc_dir_entry *pde = s->private;
-        struct ipt_hashlimit_htable *htable = pde->data;
+        struct xt_hashlimit_htable *htable = pde->data;
         unsigned int *bucket = (unsigned int *)v;
 
         *pos = ++(*bucket);
@@ -612,43 +638,59 @@ static void *dl_seq_next(struct seq_file *s, void *v, loff_t *pos)
 static void dl_seq_stop(struct seq_file *s, void *v)
 {
         struct proc_dir_entry *pde = s->private;
-        struct ipt_hashlimit_htable *htable = pde->data;
+        struct xt_hashlimit_htable *htable = pde->data;
         unsigned int *bucket = (unsigned int *)v;
 
         kfree(bucket);
-
         spin_unlock_bh(&htable->lock);
 }
 
-static inline int dl_seq_real_show(struct dsthash_ent *ent, struct seq_file *s)
+static int dl_seq_real_show(struct dsthash_ent *ent, int family,
+                                   struct seq_file *s)
 {
         /* recalculate to show accurate numbers */
         rateinfo_recalc(ent, jiffies);
 
-        return seq_printf(s, "%ld %u.%u.%u.%u:%u->%u.%u.%u.%u:%u %u %u %u\n",
-                        (long)(ent->expires - jiffies)/HZ,
-                        NIPQUAD(ent->dst.src_ip), ntohs(ent->dst.src_port),
-                        NIPQUAD(ent->dst.dst_ip), ntohs(ent->dst.dst_port),
-                        ent->rateinfo.credit, ent->rateinfo.credit_cap,
-                        ent->rateinfo.cost);
+        switch (family) {
+        case AF_INET:
+                return seq_printf(s, "%ld %u.%u.%u.%u:%u->"
+                                     "%u.%u.%u.%u:%u %u %u %u\n",
+                                 (long)(ent->expires - jiffies)/HZ,
+                                 NIPQUAD(ent->dst.addr.ip.src),
+                                 ntohs(ent->dst.src_port),
+                                 NIPQUAD(ent->dst.addr.ip.dst),
+                                 ntohs(ent->dst.dst_port),
+                                 ent->rateinfo.credit, ent->rateinfo.credit_cap,
+                                 ent->rateinfo.cost);
+        case AF_INET6:
+                return seq_printf(s, "%ld " NIP6_FMT ":%u->"
+                                     NIP6_FMT ":%u %u %u %u\n",
+                                 (long)(ent->expires - jiffies)/HZ,
+                                 NIP6(*(struct in6_addr *)&ent->dst.addr.ip6.src),
+                                 ntohs(ent->dst.src_port),
+                                 NIP6(*(struct in6_addr *)&ent->dst.addr.ip6.dst),
+                                 ntohs(ent->dst.dst_port),
+                                 ent->rateinfo.credit, ent->rateinfo.credit_cap,
+                                 ent->rateinfo.cost);
+        default:
+                BUG();
+                return 0;
+        }
 }
 
 static int dl_seq_show(struct seq_file *s, void *v)
 {
         struct proc_dir_entry *pde = s->private;
-        struct ipt_hashlimit_htable *htable = pde->data;
+        struct xt_hashlimit_htable *htable = pde->data;
         unsigned int *bucket = (unsigned int *)v;
         struct dsthash_ent *ent;
         struct hlist_node *pos;
 
-        if (!hlist_empty(&htable->hash[*bucket]))
-                hlist_for_each_entry(ent, pos, &htable->hash[*bucket], node) {
-                        if (dl_seq_real_show(ent, s)) {
-                                /* buffer was filled and unable to print that tuple */
+        if (!hlist_empty(&htable->hash[*bucket])) {
+                hlist_for_each_entry(ent, pos, &htable->hash[*bucket], node)
+                        if (dl_seq_real_show(ent, htable->family, s))
                                 return 1;
-                        }
-                }
-        
+        }
         return 0;
 }
 
@@ -678,56 +720,53 @@ static struct file_operations dl_file_ops = {
         .release = seq_release
 };
 
-static int init_or_fini(int fini)
+static int __init xt_hashlimit_init(void)
 {
-        int ret = 0;
-
-        if (fini)
-                goto cleanup;
+        int err;
 
-        if (ipt_register_match(&ipt_hashlimit)) {
-                ret = -EINVAL;
-                goto cleanup_nothing;
-        }
+        err = xt_register_matches(xt_hashlimit, ARRAY_SIZE(xt_hashlimit));
+        if (err < 0)
+                goto err1;
 
-        hashlimit_cachep = kmem_cache_create("ipt_hashlimit",
-                                            sizeof(struct dsthash_ent), 0,
-                                            0, NULL, NULL);
+        err = -ENOMEM;
+        hashlimit_cachep = kmem_cache_create("xt_hashlimit",
+                                            sizeof(struct dsthash_ent), 0, 0,
+                                            NULL, NULL);
         if (!hashlimit_cachep) {
-                printk(KERN_ERR "Unable to create ipt_hashlimit slab cache\n");
-                ret = -ENOMEM;
-                goto cleanup_unreg_match;
+                printk(KERN_ERR "xt_hashlimit: unable to create slab cache\n");
+                goto err2;
         }
-
-        hashlimit_procdir = proc_mkdir("ipt_hashlimit", proc_net);
-        if (!hashlimit_procdir) {
-                printk(KERN_ERR "Unable to create proc dir entry\n");
-                ret = -ENOMEM;
-                goto cleanup_free_slab;
+        hashlimit_procdir4 = proc_mkdir("ipt_hashlimit", proc_net);
+        if (!hashlimit_procdir4) {
+                printk(KERN_ERR "xt_hashlimit: unable to create proc dir "
+                                "entry\n");
+                goto err3;
         }
-
-        return ret;
-
-cleanup:
+        hashlimit_procdir6 = proc_mkdir("ip6t_hashlimit", proc_net);
+        if (!hashlimit_procdir6) {
+                printk(KERN_ERR "xt_hashlimit: tnable to create proc dir "
+                                "entry\n");
+                goto err4;
+        }
+        return 0;
+err4:
         remove_proc_entry("ipt_hashlimit", proc_net);
-cleanup_free_slab:
+err3:
         kmem_cache_destroy(hashlimit_cachep);
-cleanup_unreg_match:
-        ipt_unregister_match(&ipt_hashlimit);
-cleanup_nothing:
-        return ret;
-        
-}
+err2:
+        xt_unregister_matches(xt_hashlimit, ARRAY_SIZE(xt_hashlimit));
+err1:
+        return err;
 
-static int __init ipt_hashlimit_init(void)
-{
-        return init_or_fini(0);
 }
 
-static void __exit ipt_hashlimit_fini(void)
+static void __exit xt_hashlimit_fini(void)
 {
-        init_or_fini(1);
+        remove_proc_entry("ipt_hashlimit", proc_net);
+        remove_proc_entry("ip6t_hashlimit", proc_net);
+        kmem_cache_destroy(hashlimit_cachep);
+        xt_unregister_matches(xt_hashlimit, ARRAY_SIZE(xt_hashlimit));
 }
 
-module_init(ipt_hashlimit_init);
-module_exit(ipt_hashlimit_fini);
+module_init(xt_hashlimit_init);
+module_exit(xt_hashlimit_fini);