header-y += xt_DSCP.h
header-y += xt_esp.h
header-y += xt_helper.h
+header-y += xt_hashlimit.h
header-y += xt_length.h
header-y += xt_limit.h
header-y += xt_mac.h
--- /dev/null
+#ifndef _XT_HASHLIMIT_H
+#define _XT_HASHLIMIT_H
+
+/* timings are in milliseconds. */
+#define XT_HASHLIMIT_SCALE 10000
+/* 1/10,000 sec period => max of 10,000/sec. Min rate is then 429490
+ seconds, or one every 59 hours. */
+
+/* details of this structure hidden by the implementation */
+struct xt_hashlimit_htable;
+
+#define XT_HASHLIMIT_HASH_DIP 0x0001
+#define XT_HASHLIMIT_HASH_DPT 0x0002
+#define XT_HASHLIMIT_HASH_SIP 0x0004
+#define XT_HASHLIMIT_HASH_SPT 0x0008
+
+struct hashlimit_cfg {
+ u_int32_t mode; /* bitmask of IPT_HASHLIMIT_HASH_* */
+ u_int32_t avg; /* Average secs between packets * scale */
+ u_int32_t burst; /* Period multiplier for upper limit. */
+
+ /* user specified */
+ u_int32_t size; /* how many buckets */
+ u_int32_t max; /* max number of entries */
+ u_int32_t gc_interval; /* gc interval */
+ u_int32_t expire; /* when do entries expire? */
+};
+
+struct xt_hashlimit_info {
+ char name [IFNAMSIZ]; /* name */
+ struct hashlimit_cfg cfg;
+ struct xt_hashlimit_htable *hinfo;
+
+ /* Used internally by the kernel */
+ union {
+ void *ptr;
+ struct xt_hashlimit_info *master;
+ } u;
+};
+#endif /*_XT_HASHLIMIT_H*/
#ifndef _IPT_HASHLIMIT_H
#define _IPT_HASHLIMIT_H
-/* timings are in milliseconds. */
-#define IPT_HASHLIMIT_SCALE 10000
-/* 1/10,000 sec period => max of 10,000/sec. Min rate is then 429490
- seconds, or one every 59 hours. */
+#include <linux/netfilter/xt_hashlimit.h>
-/* details of this structure hidden by the implementation */
-struct ipt_hashlimit_htable;
+#define IPT_HASHLIMIT_SCALE XT_HASHLIMIT_SCALE
+#define IPT_HASHLIMIT_HASH_DIP XT_HASHLIMIT_HASH_DIP
+#define IPT_HASHLIMIT_HASH_DPT XT_HASHLIMIT_HASH_DPT
+#define IPT_HASHLIMIT_HASH_SIP XT_HASHLIMIT_HASH_SIP
+#define IPT_HASHLIMIT_HASH_SPT XT_HASHLIMIT_HASH_SPT
-#define IPT_HASHLIMIT_HASH_DIP 0x0001
-#define IPT_HASHLIMIT_HASH_DPT 0x0002
-#define IPT_HASHLIMIT_HASH_SIP 0x0004
-#define IPT_HASHLIMIT_HASH_SPT 0x0008
+#define ipt_hashlimit_info xt_hashlimit_info
-struct hashlimit_cfg {
- u_int32_t mode; /* bitmask of IPT_HASHLIMIT_HASH_* */
- u_int32_t avg; /* Average secs between packets * scale */
- u_int32_t burst; /* Period multiplier for upper limit. */
-
- /* user specified */
- u_int32_t size; /* how many buckets */
- u_int32_t max; /* max number of entries */
- u_int32_t gc_interval; /* gc interval */
- u_int32_t expire; /* when do entries expire? */
-};
-
-struct ipt_hashlimit_info {
- char name [IFNAMSIZ]; /* name */
- struct hashlimit_cfg cfg;
- struct ipt_hashlimit_htable *hinfo;
-
- /* Used internally by the kernel */
- union {
- void *ptr;
- struct ipt_hashlimit_info *master;
- } u;
-};
-#endif /*_IPT_HASHLIMIT_H*/
+#endif /* _IPT_HASHLIMIT_H */
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"
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
+++ /dev/null
-/* 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/
- *
- * 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>
-#include <linux/slab.h>
-#include <linux/vmalloc.h>
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
-#include <linux/list.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/mutex.h>
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
-MODULE_DESCRIPTION("iptables match for limiting per hash-bucket");
-
-/* need to declare this at the top */
-static struct proc_dir_entry *hashlimit_procdir;
-static struct file_operations dl_file_ops;
-
-/* hash table crap */
-
-struct dsthash_dst {
- __be32 src_ip;
- __be32 dst_ip;
- /* ports have to be consecutive !!! */
- __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 ipt_hashlimit_htable {
- struct hlist_node node; /* global list of all htables */
- atomic_t use;
-
- 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;
- struct timer_list timer; /* timer for gc */
- atomic_t count; /* number entries in table */
-
- /* 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 (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);
-}
-
-static inline u_int32_t
-hash_dst(const struct ipt_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);
-}
-
-static inline struct dsthash_ent *
-__dsthash_find(const struct ipt_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 ipt_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 &&
- atomic_read(&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",
- ht->cfg.max);
- return NULL;
- }
-
- ent = kmem_cache_alloc(hashlimit_cachep, GFP_ATOMIC);
- if (!ent) {
- if (net_ratelimit())
- printk(KERN_ERR
- "ipt_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;
-
- hlist_add_head(&ent->node, &ht->hash[hash_dst(ht, dst)]);
-
- return ent;
-}
-
-static inline void
-__dsthash_free(struct ipt_hashlimit_htable *ht, struct dsthash_ent *ent)
-{
- hlist_del(&ent->node);
- kmem_cache_free(hashlimit_cachep, ent);
- atomic_dec(&ht->count);
-}
-static void htable_gc(unsigned long htlong);
-
-static int htable_create(struct ipt_hashlimit_info *minfo)
-{
- int i;
- unsigned int size;
- struct ipt_hashlimit_htable *hinfo;
-
- 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 ipt_hashlimit_htable)
- + (sizeof(struct list_head) * size));
- if (!hinfo) {
- printk(KERN_ERR "ipt_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->count, 0);
- atomic_set(&hinfo->use, 1);
- hinfo->rnd_initialized = 0;
- spin_lock_init(&hinfo->lock);
- hinfo->pde = create_proc_entry(minfo->name, 0, hashlimit_procdir);
- 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 ipt_hashlimit_htable *ht, struct dsthash_ent *he)
-{
- return 1;
-}
-
-static int select_gc(struct ipt_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,
- struct dsthash_ent *he))
-{
- int i;
-
- IP_NF_ASSERT(ht->cfg.size && ht->cfg.max);
-
- /* 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 ipt_hashlimit_htable *ht = (struct ipt_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 ipt_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);
-
- htable_selective_cleanup(hinfo, select_all);
- vfree(hinfo);
-}
-
-static struct ipt_hashlimit_htable *htable_find_get(char *name)
-{
- struct ipt_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)) {
- 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)
-{
- 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 / IPT_HASHLIMIT_SCALE) * HZ * CREDITS_PER_JIFFY;
-
- return (user * HZ * CREDITS_PER_JIFFY) / IPT_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;
- if (dh->rateinfo.credit > dh->rateinfo.credit_cap)
- dh->rateinfo.credit = dh->rateinfo.credit_cap;
-}
-
-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 ipt_hashlimit_info *r =
- ((struct ipt_hashlimit_info *)matchinfo)->u.master;
- struct ipt_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];
- }
-
- spin_lock_bh(&hinfo->lock);
- dh = __dsthash_find(hinfo, &dst);
- if (!dh) {
- 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;
- }
-
- 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;
-}
-
-static int
-hashlimit_checkentry(const char *tablename,
- const void *inf,
- const struct xt_match *match,
- void *matchinfo,
- unsigned int hook_mask)
-{
- struct ipt_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",
- 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))
- 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
- * 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)) {
- 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 ipt_hashlimit_info *r = matchinfo;
-
- htable_put(r->hinfo);
-}
-
-#ifdef CONFIG_COMPAT
-struct compat_ipt_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_ipt_hashlimit_info, hinfo);
-
- memcpy(dst, src, off);
- memset(dst + off, 0, sizeof(struct compat_ipt_hashlimit_info) - off);
-}
-
-static int compat_to_user(void __user *dst, void *src)
-{
- int off = offsetof(struct compat_ipt_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),
-#ifdef CONFIG_COMPAT
- .compatsize = sizeof(struct compat_ipt_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 ipt_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 ipt_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 ipt_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)
-{
- /* 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);
-}
-
-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;
- 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 */
- 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_or_fini(int fini)
-{
- int ret = 0;
-
- if (fini)
- goto cleanup;
-
- if (ipt_register_match(&ipt_hashlimit)) {
- ret = -EINVAL;
- goto cleanup_nothing;
- }
-
- hashlimit_cachep = kmem_cache_create("ipt_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;
- }
-
- 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;
- }
-
- return ret;
-
-cleanup:
- remove_proc_entry("ipt_hashlimit", proc_net);
-cleanup_free_slab:
- kmem_cache_destroy(hashlimit_cachep);
-cleanup_unreg_match:
- ipt_unregister_match(&ipt_hashlimit);
-cleanup_nothing:
- return ret;
-
-}
-
-static int __init ipt_hashlimit_init(void)
-{
- return init_or_fini(0);
-}
-
-static void __exit ipt_hashlimit_fini(void)
-{
- init_or_fini(1);
-}
-
-module_init(ipt_hashlimit_init);
-module_exit(ipt_hashlimit_fini);
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
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
--- /dev/null
+/* 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);
projects / powerpc.git / commitdiff