2005-04-16 22:20:36 +00:00
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/* iptables match extension to limit the number of packets per second
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* seperately for each hashbucket (sourceip/sourceport/dstip/dstport)
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*
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* (C) 2003-2004 by Harald Welte <laforge@netfilter.org>
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*
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* $Id: ipt_hashlimit.c 3244 2004-10-20 16:24:29Z laforge@netfilter.org $
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*
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* Development of this code was funded by Astaro AG, http://www.astaro.com/
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*
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* based on ipt_limit.c by:
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* J<EFBFBD>r<EFBFBD>me de Vivie <devivie@info.enserb.u-bordeaux.fr>
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* Herv<EFBFBD> Eychenne <eychenne@info.enserb.u-bordeaux.fr>
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* Rusty Russell <rusty@rustcorp.com.au>
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*
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* The general idea is to create a hash table for every dstip and have a
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* seperate limit counter per tuple. This way you can do something like 'limit
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* the number of syn packets for each of my internal addresses.
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*
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* Ideally this would just be implemented as a general 'hash' match, which would
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* allow us to attach any iptables target to it's hash buckets. But this is
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* not possible in the current iptables architecture. As always, pkttables for
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* 2.7.x will help ;)
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*/
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/spinlock.h>
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#include <linux/random.h>
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#include <linux/jhash.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <linux/tcp.h>
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#include <linux/udp.h>
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#include <linux/sctp.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/list.h>
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#include <linux/netfilter_ipv4/ip_tables.h>
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#include <linux/netfilter_ipv4/ipt_hashlimit.h>
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/* FIXME: this is just for IP_NF_ASSERRT */
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#include <linux/netfilter_ipv4/ip_conntrack.h>
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2006-03-26 09:37:14 +00:00
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#include <linux/mutex.h>
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2005-04-16 22:20:36 +00:00
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
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MODULE_DESCRIPTION("iptables match for limiting per hash-bucket");
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/* need to declare this at the top */
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static struct proc_dir_entry *hashlimit_procdir;
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static struct file_operations dl_file_ops;
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/* hash table crap */
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struct dsthash_dst {
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u_int32_t src_ip;
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u_int32_t dst_ip;
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/* ports have to be consecutive !!! */
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u_int16_t src_port;
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u_int16_t dst_port;
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};
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struct dsthash_ent {
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/* static / read-only parts in the beginning */
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struct hlist_node node;
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struct dsthash_dst dst;
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/* modified structure members in the end */
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unsigned long expires; /* precalculated expiry time */
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struct {
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unsigned long prev; /* last modification */
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u_int32_t credit;
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u_int32_t credit_cap, cost;
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} rateinfo;
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};
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struct ipt_hashlimit_htable {
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struct hlist_node node; /* global list of all htables */
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atomic_t use;
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struct hashlimit_cfg cfg; /* config */
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/* used internally */
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spinlock_t lock; /* lock for list_head */
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u_int32_t rnd; /* random seed for hash */
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struct timer_list timer; /* timer for gc */
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atomic_t count; /* number entries in table */
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/* seq_file stuff */
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struct proc_dir_entry *pde;
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struct hlist_head hash[0]; /* hashtable itself */
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};
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2005-06-21 21:01:30 +00:00
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static DEFINE_SPINLOCK(hashlimit_lock); /* protects htables list */
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2006-03-26 09:37:14 +00:00
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static DEFINE_MUTEX(hlimit_mutex); /* additional checkentry protection */
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2005-04-16 22:20:36 +00:00
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static HLIST_HEAD(hashlimit_htables);
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2005-08-26 19:05:31 +00:00
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static kmem_cache_t *hashlimit_cachep __read_mostly;
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2005-04-16 22:20:36 +00:00
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static inline int dst_cmp(const struct dsthash_ent *ent, struct dsthash_dst *b)
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{
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return (ent->dst.dst_ip == b->dst_ip
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&& ent->dst.dst_port == b->dst_port
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&& ent->dst.src_port == b->src_port
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&& ent->dst.src_ip == b->src_ip);
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}
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static inline u_int32_t
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hash_dst(const struct ipt_hashlimit_htable *ht, const struct dsthash_dst *dst)
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{
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return (jhash_3words(dst->dst_ip, (dst->dst_port<<16 | dst->src_port),
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dst->src_ip, ht->rnd) % ht->cfg.size);
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}
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static inline struct dsthash_ent *
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__dsthash_find(const struct ipt_hashlimit_htable *ht, struct dsthash_dst *dst)
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{
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struct dsthash_ent *ent;
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struct hlist_node *pos;
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u_int32_t hash = hash_dst(ht, dst);
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if (!hlist_empty(&ht->hash[hash]))
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hlist_for_each_entry(ent, pos, &ht->hash[hash], node) {
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if (dst_cmp(ent, dst)) {
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return ent;
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}
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}
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return NULL;
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}
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/* allocate dsthash_ent, initialize dst, put in htable and lock it */
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static struct dsthash_ent *
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__dsthash_alloc_init(struct ipt_hashlimit_htable *ht, struct dsthash_dst *dst)
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{
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struct dsthash_ent *ent;
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/* initialize hash with random val at the time we allocate
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* the first hashtable entry */
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if (!ht->rnd)
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get_random_bytes(&ht->rnd, 4);
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if (ht->cfg.max &&
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atomic_read(&ht->count) >= ht->cfg.max) {
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/* FIXME: do something. question is what.. */
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if (net_ratelimit())
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printk(KERN_WARNING
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"ipt_hashlimit: max count of %u reached\n",
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ht->cfg.max);
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return NULL;
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}
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ent = kmem_cache_alloc(hashlimit_cachep, GFP_ATOMIC);
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if (!ent) {
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if (net_ratelimit())
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printk(KERN_ERR
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"ipt_hashlimit: can't allocate dsthash_ent\n");
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return NULL;
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}
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atomic_inc(&ht->count);
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ent->dst.dst_ip = dst->dst_ip;
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ent->dst.dst_port = dst->dst_port;
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ent->dst.src_ip = dst->src_ip;
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ent->dst.src_port = dst->src_port;
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hlist_add_head(&ent->node, &ht->hash[hash_dst(ht, dst)]);
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return ent;
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}
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static inline void
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__dsthash_free(struct ipt_hashlimit_htable *ht, struct dsthash_ent *ent)
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{
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hlist_del(&ent->node);
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kmem_cache_free(hashlimit_cachep, ent);
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atomic_dec(&ht->count);
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}
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static void htable_gc(unsigned long htlong);
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static int htable_create(struct ipt_hashlimit_info *minfo)
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{
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int i;
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unsigned int size;
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struct ipt_hashlimit_htable *hinfo;
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if (minfo->cfg.size)
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size = minfo->cfg.size;
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else {
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size = (((num_physpages << PAGE_SHIFT) / 16384)
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/ sizeof(struct list_head));
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if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
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size = 8192;
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if (size < 16)
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size = 16;
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}
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/* FIXME: don't use vmalloc() here or anywhere else -HW */
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hinfo = vmalloc(sizeof(struct ipt_hashlimit_htable)
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+ (sizeof(struct list_head) * size));
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if (!hinfo) {
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printk(KERN_ERR "ipt_hashlimit: Unable to create hashtable\n");
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return -1;
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}
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minfo->hinfo = hinfo;
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/* copy match config into hashtable config */
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memcpy(&hinfo->cfg, &minfo->cfg, sizeof(hinfo->cfg));
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hinfo->cfg.size = size;
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if (!hinfo->cfg.max)
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hinfo->cfg.max = 8 * hinfo->cfg.size;
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else if (hinfo->cfg.max < hinfo->cfg.size)
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hinfo->cfg.max = hinfo->cfg.size;
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for (i = 0; i < hinfo->cfg.size; i++)
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INIT_HLIST_HEAD(&hinfo->hash[i]);
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atomic_set(&hinfo->count, 0);
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atomic_set(&hinfo->use, 1);
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hinfo->rnd = 0;
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spin_lock_init(&hinfo->lock);
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hinfo->pde = create_proc_entry(minfo->name, 0, hashlimit_procdir);
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if (!hinfo->pde) {
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vfree(hinfo);
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return -1;
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}
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hinfo->pde->proc_fops = &dl_file_ops;
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hinfo->pde->data = hinfo;
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init_timer(&hinfo->timer);
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hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
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hinfo->timer.data = (unsigned long )hinfo;
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hinfo->timer.function = htable_gc;
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add_timer(&hinfo->timer);
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2005-06-21 21:01:30 +00:00
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spin_lock_bh(&hashlimit_lock);
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2005-04-16 22:20:36 +00:00
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hlist_add_head(&hinfo->node, &hashlimit_htables);
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2005-06-21 21:01:30 +00:00
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spin_unlock_bh(&hashlimit_lock);
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2005-04-16 22:20:36 +00:00
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return 0;
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}
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static int select_all(struct ipt_hashlimit_htable *ht, struct dsthash_ent *he)
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{
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return 1;
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}
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static int select_gc(struct ipt_hashlimit_htable *ht, struct dsthash_ent *he)
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{
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return (jiffies >= he->expires);
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}
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static void htable_selective_cleanup(struct ipt_hashlimit_htable *ht,
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int (*select)(struct ipt_hashlimit_htable *ht,
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struct dsthash_ent *he))
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{
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int i;
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IP_NF_ASSERT(ht->cfg.size && ht->cfg.max);
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/* lock hash table and iterate over it */
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spin_lock_bh(&ht->lock);
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for (i = 0; i < ht->cfg.size; i++) {
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struct dsthash_ent *dh;
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struct hlist_node *pos, *n;
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hlist_for_each_entry_safe(dh, pos, n, &ht->hash[i], node) {
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if ((*select)(ht, dh))
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__dsthash_free(ht, dh);
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}
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}
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spin_unlock_bh(&ht->lock);
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}
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/* hash table garbage collector, run by timer */
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static void htable_gc(unsigned long htlong)
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{
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struct ipt_hashlimit_htable *ht = (struct ipt_hashlimit_htable *)htlong;
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htable_selective_cleanup(ht, select_gc);
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/* re-add the timer accordingly */
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ht->timer.expires = jiffies + msecs_to_jiffies(ht->cfg.gc_interval);
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add_timer(&ht->timer);
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}
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static void htable_destroy(struct ipt_hashlimit_htable *hinfo)
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{
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/* remove timer, if it is pending */
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if (timer_pending(&hinfo->timer))
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del_timer(&hinfo->timer);
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/* remove proc entry */
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remove_proc_entry(hinfo->pde->name, hashlimit_procdir);
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htable_selective_cleanup(hinfo, select_all);
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vfree(hinfo);
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}
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static struct ipt_hashlimit_htable *htable_find_get(char *name)
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{
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struct ipt_hashlimit_htable *hinfo;
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struct hlist_node *pos;
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|
2005-06-21 21:01:30 +00:00
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spin_lock_bh(&hashlimit_lock);
|
2005-04-16 22:20:36 +00:00
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hlist_for_each_entry(hinfo, pos, &hashlimit_htables, node) {
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if (!strcmp(name, hinfo->pde->name)) {
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atomic_inc(&hinfo->use);
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2005-06-21 21:01:30 +00:00
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spin_unlock_bh(&hashlimit_lock);
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2005-04-16 22:20:36 +00:00
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|
|
return hinfo;
|
|
|
|
|
}
|
|
|
|
|
}
|
2005-06-21 21:01:30 +00:00
|
|
|
|
spin_unlock_bh(&hashlimit_lock);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void htable_put(struct ipt_hashlimit_htable *hinfo)
|
|
|
|
|
{
|
|
|
|
|
if (atomic_dec_and_test(&hinfo->use)) {
|
2005-06-21 21:01:30 +00:00
|
|
|
|
spin_lock_bh(&hashlimit_lock);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
hlist_del(&hinfo->node);
|
2005-06-21 21:01:30 +00:00
|
|
|
|
spin_unlock_bh(&hashlimit_lock);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
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 inline int get_ports(const struct sk_buff *skb, int offset,
|
|
|
|
|
u16 ports[2])
|
|
|
|
|
{
|
|
|
|
|
union {
|
|
|
|
|
struct tcphdr th;
|
|
|
|
|
struct udphdr uh;
|
|
|
|
|
sctp_sctphdr_t sctph;
|
|
|
|
|
} hdr_u, *ptr_u;
|
|
|
|
|
|
|
|
|
|
/* Must not be a fragment. */
|
|
|
|
|
if (offset)
|
|
|
|
|
return 1;
|
|
|
|
|
|
|
|
|
|
/* Must be big enough to read ports (both UDP and TCP have
|
|
|
|
|
them at the start). */
|
|
|
|
|
ptr_u = skb_header_pointer(skb, skb->nh.iph->ihl*4, 8, &hdr_u);
|
|
|
|
|
if (!ptr_u)
|
|
|
|
|
return 1;
|
|
|
|
|
|
|
|
|
|
switch (skb->nh.iph->protocol) {
|
|
|
|
|
case IPPROTO_TCP:
|
|
|
|
|
ports[0] = ptr_u->th.source;
|
|
|
|
|
ports[1] = ptr_u->th.dest;
|
|
|
|
|
break;
|
|
|
|
|
case IPPROTO_UDP:
|
|
|
|
|
ports[0] = ptr_u->uh.source;
|
|
|
|
|
ports[1] = ptr_u->uh.dest;
|
|
|
|
|
break;
|
|
|
|
|
case IPPROTO_SCTP:
|
|
|
|
|
ports[0] = ptr_u->sctph.source;
|
|
|
|
|
ports[1] = ptr_u->sctph.dest;
|
|
|
|
|
break;
|
|
|
|
|
default:
|
|
|
|
|
/* all other protocols don't supprot per-port hash
|
|
|
|
|
* buckets */
|
|
|
|
|
ports[0] = ports[1] = 0;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
static int
|
|
|
|
|
hashlimit_match(const struct sk_buff *skb,
|
|
|
|
|
const struct net_device *in,
|
|
|
|
|
const struct net_device *out,
|
2006-03-21 02:02:56 +00:00
|
|
|
|
const struct xt_match *match,
|
2005-04-16 22:20:36 +00:00
|
|
|
|
const void *matchinfo,
|
|
|
|
|
int offset,
|
[NETFILTER] x_tables: Abstraction layer for {ip,ip6,arp}_tables
This monster-patch tries to do the best job for unifying the data
structures and backend interfaces for the three evil clones ip_tables,
ip6_tables and arp_tables. In an ideal world we would never have
allowed this kind of copy+paste programming... but well, our world
isn't (yet?) ideal.
o introduce a new x_tables module
o {ip,arp,ip6}_tables depend on this x_tables module
o registration functions for tables, matches and targets are only
wrappers around x_tables provided functions
o all matches/targets that are used from ip_tables and ip6_tables
are now implemented as xt_FOOBAR.c files and provide module aliases
to ipt_FOOBAR and ip6t_FOOBAR
o header files for xt_matches are in include/linux/netfilter/,
include/linux/netfilter_{ipv4,ipv6} contains compatibility wrappers
around the xt_FOOBAR.h headers
Based on this patchset we're going to further unify the code,
gradually getting rid of all the layer 3 specific assumptions.
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-12 21:30:04 +00:00
|
|
|
|
unsigned int protoff,
|
2005-04-16 22:20:36 +00:00
|
|
|
|
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) {
|
|
|
|
|
u_int16_t ports[2];
|
|
|
|
|
if (get_ports(skb, offset, 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);
|
|
|
|
|
|
|
|
|
|
spin_unlock_bh(&hinfo->lock);
|
|
|
|
|
return 1;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* 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,
|
[NETFILTER] x_tables: Abstraction layer for {ip,ip6,arp}_tables
This monster-patch tries to do the best job for unifying the data
structures and backend interfaces for the three evil clones ip_tables,
ip6_tables and arp_tables. In an ideal world we would never have
allowed this kind of copy+paste programming... but well, our world
isn't (yet?) ideal.
o introduce a new x_tables module
o {ip,arp,ip6}_tables depend on this x_tables module
o registration functions for tables, matches and targets are only
wrappers around x_tables provided functions
o all matches/targets that are used from ip_tables and ip6_tables
are now implemented as xt_FOOBAR.c files and provide module aliases
to ipt_FOOBAR and ip6t_FOOBAR
o header files for xt_matches are in include/linux/netfilter/,
include/linux/netfilter_{ipv4,ipv6} contains compatibility wrappers
around the xt_FOOBAR.h headers
Based on this patchset we're going to further unify the code,
gradually getting rid of all the layer 3 specific assumptions.
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-12 21:30:04 +00:00
|
|
|
|
const void *inf,
|
2006-03-21 02:02:56 +00:00
|
|
|
|
const struct xt_match *match,
|
2005-04-16 22:20:36 +00:00
|
|
|
|
void *matchinfo,
|
|
|
|
|
unsigned int matchsize,
|
|
|
|
|
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;
|
|
|
|
|
|
|
|
|
|
/* 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 */
|
2006-03-26 09:37:14 +00:00
|
|
|
|
mutex_lock(&hlimit_mutex);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
r->hinfo = htable_find_get(r->name);
|
|
|
|
|
if (!r->hinfo && (htable_create(r) != 0)) {
|
2006-03-26 09:37:14 +00:00
|
|
|
|
mutex_unlock(&hlimit_mutex);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
return 0;
|
|
|
|
|
}
|
2006-03-26 09:37:14 +00:00
|
|
|
|
mutex_unlock(&hlimit_mutex);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
|
|
/* Ugly hack: For SMP, we only want to use one set */
|
|
|
|
|
r->u.master = r;
|
|
|
|
|
|
|
|
|
|
return 1;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void
|
2006-03-21 02:02:56 +00:00
|
|
|
|
hashlimit_destroy(const struct xt_match *match, void *matchinfo,
|
|
|
|
|
unsigned int matchsize)
|
2005-04-16 22:20:36 +00:00
|
|
|
|
{
|
|
|
|
|
struct ipt_hashlimit_info *r = (struct ipt_hashlimit_info *) matchinfo;
|
|
|
|
|
|
|
|
|
|
htable_put(r->hinfo);
|
|
|
|
|
}
|
|
|
|
|
|
2006-03-21 02:01:14 +00:00
|
|
|
|
static struct ipt_match ipt_hashlimit = {
|
|
|
|
|
.name = "hashlimit",
|
|
|
|
|
.match = hashlimit_match,
|
|
|
|
|
.matchsize = sizeof(struct ipt_hashlimit_info),
|
|
|
|
|
.checkentry = hashlimit_checkentry,
|
|
|
|
|
.destroy = hashlimit_destroy,
|
|
|
|
|
.me = THIS_MODULE
|
2005-04-16 22:20:36 +00:00
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
/* 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 init(void)
|
|
|
|
|
{
|
|
|
|
|
return init_or_fini(0);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void __exit fini(void)
|
|
|
|
|
{
|
|
|
|
|
init_or_fini(1);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
module_init(init);
|
|
|
|
|
module_exit(fini);
|