[NETFILTER]: x_tables: add port of hashlimit match for IPv4 and IPv6
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c
new file mode 100644
index 0000000..46de566
--- /dev/null
+++ b/net/netfilter/xt_hashlimit.c
@@ -0,0 +1,772 @@
+/* iptables match extension to limit the number of packets per second
+ * seperately for each hashbucket (sourceip/sourceport/dstip/dstport)
+ *
+ * (C) 2003-2004 by Harald Welte <laforge@netfilter.org>
+ *
+ * $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/
+ */
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/random.h>
+#include <linux/jhash.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#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_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_procdir4;
+static struct proc_dir_entry *hashlimit_procdir6;
+static struct file_operations dl_file_ops;
+
+/* hash table crap */
+struct dsthash_dst {
+ union {
+ struct {
+ __be32 src;
+ __be32 dst;
+ } ip;
+ struct {
+ __be32 src[4];
+ __be32 dst[4];
+ } ip6;
+ } addr;
+ __be16 src_port;
+ __be16 dst_port;
+};
+
+struct dsthash_ent {
+ /* static / read-only parts in the beginning */
+ struct hlist_node node;
+ struct dsthash_dst dst;
+
+ /* modified structure members in the end */
+ unsigned long expires; /* precalculated expiry time */
+ struct {
+ unsigned long prev; /* last modification */
+ u_int32_t credit;
+ u_int32_t credit_cap, cost;
+ } rateinfo;
+};
+
+struct xt_hashlimit_htable {
+ struct hlist_node node; /* global list of all htables */
+ atomic_t use;
+ int family;
+
+ struct hashlimit_cfg cfg; /* config */
+
+ /* used internally */
+ 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 */
+
+ /* seq_file stuff */
+ struct proc_dir_entry *pde;
+
+ struct hlist_head hash[0]; /* hashtable itself */
+};
+
+static DEFINE_SPINLOCK(hashlimit_lock); /* protects htables list */
+static DEFINE_MUTEX(hlimit_mutex); /* additional checkentry protection */
+static HLIST_HEAD(hashlimit_htables);
+static kmem_cache_t *hashlimit_cachep __read_mostly;
+
+static inline int dst_cmp(const struct dsthash_ent *ent, struct dsthash_dst *b)
+{
+ return !memcmp(&ent->dst, b, sizeof(ent->dst));
+}
+
+static u_int32_t
+hash_dst(const struct xt_hashlimit_htable *ht, const struct dsthash_dst *dst)
+{
+ return jhash(dst, sizeof(*dst), ht->rnd) % ht->cfg.size;
+}
+
+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))
+ return ent;
+ }
+ return NULL;
+}
+
+/* allocate dsthash_ent, initialize dst, put in htable and lock it */
+static struct dsthash_ent *
+dsthash_alloc_init(struct xt_hashlimit_htable *ht, struct dsthash_dst *dst)
+{
+ struct dsthash_ent *ent;
+
+ /* initialize hash with random val at the time we allocate
+ * the first hashtable entry */
+ if (!ht->rnd_initialized) {
+ get_random_bytes(&ht->rnd, 4);
+ ht->rnd_initialized = 1;
+ }
+
+ if (ht->cfg.max && ht->count >= ht->cfg.max) {
+ /* FIXME: do something. question is what.. */
+ if (net_ratelimit())
+ printk(KERN_WARNING
+ "xt_hashlimit: max count of %u reached\n",
+ ht->cfg.max);
+ return NULL;
+ }
+
+ ent = kmem_cache_alloc(hashlimit_cachep, GFP_ATOMIC);
+ if (!ent) {
+ if (net_ratelimit())
+ printk(KERN_ERR
+ "xt_hashlimit: can't allocate dsthash_ent\n");
+ return NULL;
+ }
+ 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 xt_hashlimit_htable *ht, struct dsthash_ent *ent)
+{
+ hlist_del(&ent->node);
+ kmem_cache_free(hashlimit_cachep, ent);
+ ht->count--;
+}
+static void htable_gc(unsigned long htlong);
+
+static int htable_create(struct xt_hashlimit_info *minfo, int family)
+{
+ struct xt_hashlimit_htable *hinfo;
+ unsigned int size;
+ unsigned int i;
+
+ if (minfo->cfg.size)
+ size = minfo->cfg.size;
+ else {
+ 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 xt_hashlimit_htable) +
+ sizeof(struct list_head) * size);
+ if (!hinfo) {
+ printk(KERN_ERR "xt_hashlimit: unable to create hashtable\n");
+ return -1;
+ }
+ minfo->hinfo = hinfo;
+
+ /* copy match config into hashtable config */
+ memcpy(&hinfo->cfg, &minfo->cfg, sizeof(hinfo->cfg));
+ hinfo->cfg.size = size;
+ if (!hinfo->cfg.max)
+ hinfo->cfg.max = 8 * hinfo->cfg.size;
+ else if (hinfo->cfg.max < hinfo->cfg.size)
+ hinfo->cfg.max = hinfo->cfg.size;
+
+ for (i = 0; i < hinfo->cfg.size; i++)
+ INIT_HLIST_HEAD(&hinfo->hash[i]);
+
+ 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,
+ family == AF_INET ? hashlimit_procdir4 :
+ hashlimit_procdir6);
+ if (!hinfo->pde) {
+ vfree(hinfo);
+ return -1;
+ }
+ hinfo->pde->proc_fops = &dl_file_ops;
+ hinfo->pde->data = hinfo;
+
+ init_timer(&hinfo->timer);
+ hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
+ hinfo->timer.data = (unsigned long )hinfo;
+ hinfo->timer.function = htable_gc;
+ add_timer(&hinfo->timer);
+
+ spin_lock_bh(&hashlimit_lock);
+ hlist_add_head(&hinfo->node, &hashlimit_htables);
+ spin_unlock_bh(&hashlimit_lock);
+
+ return 0;
+}
+
+static int select_all(struct xt_hashlimit_htable *ht, struct dsthash_ent *he)
+{
+ return 1;
+}
+
+static int select_gc(struct xt_hashlimit_htable *ht, struct dsthash_ent *he)
+{
+ return (jiffies >= he->expires);
+}
+
+static void htable_selective_cleanup(struct xt_hashlimit_htable *ht,
+ int (*select)(struct xt_hashlimit_htable *ht,
+ struct dsthash_ent *he))
+{
+ unsigned int i;
+
+ /* lock hash table and iterate over it */
+ spin_lock_bh(&ht->lock);
+ for (i = 0; i < ht->cfg.size; i++) {
+ struct dsthash_ent *dh;
+ 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);
+ }
+ }
+ spin_unlock_bh(&ht->lock);
+}
+
+/* hash table garbage collector, run by timer */
+static void htable_gc(unsigned long htlong)
+{
+ struct xt_hashlimit_htable *ht = (struct xt_hashlimit_htable *)htlong;
+
+ htable_selective_cleanup(ht, select_gc);
+
+ /* re-add the timer accordingly */
+ ht->timer.expires = jiffies + msecs_to_jiffies(ht->cfg.gc_interval);
+ add_timer(&ht->timer);
+}
+
+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,
+ hinfo->family == AF_INET ? hashlimit_procdir4 :
+ hashlimit_procdir6);
+ htable_selective_cleanup(hinfo, select_all);
+ vfree(hinfo);
+}
+
+static struct xt_hashlimit_htable *htable_find_get(char *name, int family)
+{
+ 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) &&
+ 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 xt_hashlimit_htable *hinfo)
+{
+ if (atomic_dec_and_test(&hinfo->use)) {
+ spin_lock_bh(&hashlimit_lock);
+ hlist_del(&hinfo->node);
+ spin_unlock_bh(&hashlimit_lock);
+ htable_destroy(hinfo);
+ }
+}
+
+/* The algorithm used is the Simple Token Bucket Filter (TBF)
+ * see net/sched/sch_tbf.c in the linux source tree
+ */
+
+/* Rusty: This is my (non-mathematically-inclined) understanding of
+ this algorithm. The `average rate' in jiffies becomes your initial
+ amount of credit `credit' and the most credit you can ever have
+ `credit_cap'. The `peak rate' becomes the cost of passing the
+ test, `cost'.
+
+ `prev' tracks the last packet hit: you gain one credit per jiffy.
+ If you get credit balance more than this, the extra credit is
+ discarded. Every time the match passes, you lose `cost' credits;
+ if you don't have that many, the test fails.
+
+ See Alexey's formal explanation in net/sched/sch_tbf.c.
+
+ To get the maximum range, we multiply by this factor (ie. you get N
+ credits per jiffy). We want to allow a rate as low as 1 per day
+ (slowest userspace tool allows), which means
+ CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32 ie.
+*/
+#define MAX_CPJ (0xFFFFFFFF / (HZ*60*60*24))
+
+/* Repeated shift and or gives us all 1s, final shift and add 1 gives
+ * us the power of 2 below the theoretical max, so GCC simply does a
+ * shift. */
+#define _POW2_BELOW2(x) ((x)|((x)>>1))
+#define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2))
+#define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4))
+#define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8))
+#define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16))
+#define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1)
+
+#define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ)
+
+/* Precision saver. */
+static inline u_int32_t
+user2credits(u_int32_t user)
+{
+ /* If multiplying would overflow... */
+ if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY))
+ /* Divide first. */
+ return (user / XT_HASHLIMIT_SCALE) * HZ * CREDITS_PER_JIFFY;
+
+ 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 - 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
+hashlimit_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)
+{
+ 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;
+
+ if (hashlimit_init_dst(hinfo, &dst, skb, protoff) < 0)
+ goto hotdrop;
+
+ spin_lock_bh(&hinfo->lock);
+ dh = dsthash_find(hinfo, &dst);
+ if (!dh) {
+ dh = dsthash_alloc_init(hinfo, &dst);
+ if (!dh) {
+ spin_unlock_bh(&hinfo->lock);
+ 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.cost = user2credits(hinfo->cfg.avg);
+ } else {
+ /* update expiration timeout */
+ dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire);
+ rateinfo_recalc(dh, now);
+ }
+
+ if (dh->rateinfo.credit >= dh->rateinfo.cost) {
+ /* We're underlimit. */
+ dh->rateinfo.credit -= dh->rateinfo.cost;
+ spin_unlock_bh(&hinfo->lock);
+ return 1;
+ }
+
+ spin_unlock_bh(&hinfo->lock);
+
+ /* default case: we're overlimit, thus don't match */
+ return 0;
+
+hotdrop:
+ *hotdrop = 1;
+ return 0;
+}
+
+static int
+hashlimit_checkentry(const char *tablename,
+ const void *inf,
+ const struct xt_match *match,
+ void *matchinfo,
+ unsigned int hook_mask)
+{
+ 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 "xt_hashlimit: overflow, try lower: %u/%u\n",
+ r->cfg.avg, r->cfg.burst);
+ return 0;
+ }
+ 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 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, match->family);
+ if (!r->hinfo && htable_create(r, match->family) != 0) {
+ mutex_unlock(&hlimit_mutex);
+ return 0;
+ }
+ mutex_unlock(&hlimit_mutex);
+
+ /* 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 xt_hashlimit_info *r = matchinfo;
+
+ htable_put(r->hinfo);
+}
+
+#ifdef CONFIG_COMPAT
+struct compat_xt_hashlimit_info {
+ char name[IFNAMSIZ];
+ struct hashlimit_cfg cfg;
+ compat_uptr_t hinfo;
+ compat_uptr_t master;
+};
+
+static void compat_from_user(void *dst, void *src)
+{
+ int off = offsetof(struct compat_xt_hashlimit_info, hinfo);
+
+ memcpy(dst, src, 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_xt_hashlimit_info, hinfo);
+
+ return copy_to_user(dst, src, off) ? -EFAULT : 0;
+}
+#endif
+
+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_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
+ },
+};
+
+/* PROC stuff */
+static void *dl_seq_start(struct seq_file *s, loff_t *pos)
+{
+ struct proc_dir_entry *pde = s->private;
+ struct xt_hashlimit_htable *htable = pde->data;
+ unsigned int *bucket;
+
+ spin_lock_bh(&htable->lock);
+ if (*pos >= htable->cfg.size)
+ return NULL;
+
+ bucket = kmalloc(sizeof(unsigned int), GFP_ATOMIC);
+ if (!bucket)
+ return ERR_PTR(-ENOMEM);
+
+ *bucket = *pos;
+ return bucket;
+}
+
+static void *dl_seq_next(struct seq_file *s, void *v, loff_t *pos)
+{
+ struct proc_dir_entry *pde = s->private;
+ struct xt_hashlimit_htable *htable = pde->data;
+ unsigned int *bucket = (unsigned int *)v;
+
+ *pos = ++(*bucket);
+ if (*pos >= htable->cfg.size) {
+ kfree(v);
+ return NULL;
+ }
+ return bucket;
+}
+
+static void dl_seq_stop(struct seq_file *s, void *v)
+{
+ struct proc_dir_entry *pde = s->private;
+ struct xt_hashlimit_htable *htable = pde->data;
+ unsigned int *bucket = (unsigned int *)v;
+
+ kfree(bucket);
+ spin_unlock_bh(&htable->lock);
+}
+
+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);
+
+ 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 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, htable->family, s))
+ return 1;
+ }
+ return 0;
+}
+
+static struct seq_operations dl_seq_ops = {
+ .start = dl_seq_start,
+ .next = dl_seq_next,
+ .stop = dl_seq_stop,
+ .show = dl_seq_show
+};
+
+static int dl_proc_open(struct inode *inode, struct file *file)
+{
+ int ret = seq_open(file, &dl_seq_ops);
+
+ if (!ret) {
+ struct seq_file *sf = file->private_data;
+ sf->private = PDE(inode);
+ }
+ return ret;
+}
+
+static struct file_operations dl_file_ops = {
+ .owner = THIS_MODULE,
+ .open = dl_proc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release
+};
+
+static int __init xt_hashlimit_init(void)
+{
+ int err;
+
+ err = xt_register_matches(xt_hashlimit, ARRAY_SIZE(xt_hashlimit));
+ if (err < 0)
+ goto err1;
+
+ err = -ENOMEM;
+ hashlimit_cachep = kmem_cache_create("xt_hashlimit",
+ sizeof(struct dsthash_ent), 0, 0,
+ NULL, NULL);
+ if (!hashlimit_cachep) {
+ printk(KERN_ERR "xt_hashlimit: unable to create slab cache\n");
+ goto err2;
+ }
+ 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;
+ }
+ 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);
+err3:
+ kmem_cache_destroy(hashlimit_cachep);
+err2:
+ xt_unregister_matches(xt_hashlimit, ARRAY_SIZE(xt_hashlimit));
+err1:
+ return err;
+
+}
+
+static void __exit xt_hashlimit_fini(void)
+{
+ 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(xt_hashlimit_init);
+module_exit(xt_hashlimit_fini);
