14d5e834f6
Using NIPQUAD() with NIPQUAD_FMT, %d.%d.%d.%d or %u.%u.%u.%u can be replaced with %pI4 Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1019 lines
27 KiB
C
1019 lines
27 KiB
C
/*
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* xt_hashlimit - Netfilter module to limit the number of packets per time
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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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* Copyright © CC Computer Consultants GmbH, 2007 - 2008
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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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#include <linux/module.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/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/skbuff.h>
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#include <linux/mm.h>
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#include <linux/in.h>
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#include <linux/ip.h>
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#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
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#include <linux/ipv6.h>
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#include <net/ipv6.h>
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#endif
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#include <net/net_namespace.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter_ipv4/ip_tables.h>
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#include <linux/netfilter_ipv6/ip6_tables.h>
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#include <linux/netfilter/xt_hashlimit.h>
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#include <linux/mutex.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
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MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
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MODULE_DESCRIPTION("Xtables: per hash-bucket rate-limit match");
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MODULE_ALIAS("ipt_hashlimit");
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MODULE_ALIAS("ip6t_hashlimit");
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/* need to declare this at the top */
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static struct proc_dir_entry *hashlimit_procdir4;
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static struct proc_dir_entry *hashlimit_procdir6;
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static const struct file_operations dl_file_ops;
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/* hash table crap */
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struct dsthash_dst {
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union {
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struct {
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__be32 src;
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__be32 dst;
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} ip;
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#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
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struct {
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__be32 src[4];
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__be32 dst[4];
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} ip6;
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#endif
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};
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__be16 src_port;
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__be16 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 xt_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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u_int8_t family;
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struct hashlimit_cfg1 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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int rnd_initialized;
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unsigned int count; /* number entries in table */
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struct timer_list timer; /* timer for gc */
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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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static DEFINE_SPINLOCK(hashlimit_lock); /* protects htables list */
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static DEFINE_MUTEX(hlimit_mutex); /* additional checkentry protection */
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static HLIST_HEAD(hashlimit_htables);
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static struct kmem_cache *hashlimit_cachep __read_mostly;
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static inline bool dst_cmp(const struct dsthash_ent *ent,
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const struct dsthash_dst *b)
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{
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return !memcmp(&ent->dst, b, sizeof(ent->dst));
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}
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static u_int32_t
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hash_dst(const struct xt_hashlimit_htable *ht, const struct dsthash_dst *dst)
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{
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u_int32_t hash = jhash2((const u32 *)dst,
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sizeof(*dst)/sizeof(u32),
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ht->rnd);
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/*
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* Instead of returning hash % ht->cfg.size (implying a divide)
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* we return the high 32 bits of the (hash * ht->cfg.size) that will
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* give results between [0 and cfg.size-1] and same hash distribution,
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* but using a multiply, less expensive than a divide
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*/
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return ((u64)hash * ht->cfg.size) >> 32;
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}
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static struct dsthash_ent *
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dsthash_find(const struct xt_hashlimit_htable *ht,
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const 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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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 xt_hashlimit_htable *ht,
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const 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_initialized) {
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get_random_bytes(&ht->rnd, 4);
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ht->rnd_initialized = 1;
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}
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if (ht->cfg.max && 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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"xt_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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"xt_hashlimit: can't allocate dsthash_ent\n");
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return NULL;
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}
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memcpy(&ent->dst, dst, sizeof(ent->dst));
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hlist_add_head(&ent->node, &ht->hash[hash_dst(ht, dst)]);
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ht->count++;
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return ent;
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}
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static inline void
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dsthash_free(struct xt_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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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_v0(struct xt_hashlimit_info *minfo, u_int8_t family)
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{
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struct xt_hashlimit_htable *hinfo;
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unsigned int size;
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unsigned int i;
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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 xt_hashlimit_htable) +
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sizeof(struct list_head) * size);
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if (!hinfo) {
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printk(KERN_ERR "xt_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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hinfo->cfg.mode = minfo->cfg.mode;
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hinfo->cfg.avg = minfo->cfg.avg;
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hinfo->cfg.burst = minfo->cfg.burst;
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hinfo->cfg.max = minfo->cfg.max;
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hinfo->cfg.gc_interval = minfo->cfg.gc_interval;
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hinfo->cfg.expire = minfo->cfg.expire;
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if (family == NFPROTO_IPV4)
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hinfo->cfg.srcmask = hinfo->cfg.dstmask = 32;
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else
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hinfo->cfg.srcmask = hinfo->cfg.dstmask = 128;
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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->use, 1);
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hinfo->count = 0;
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hinfo->family = family;
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hinfo->rnd_initialized = 0;
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spin_lock_init(&hinfo->lock);
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hinfo->pde = proc_create_data(minfo->name, 0,
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(family == NFPROTO_IPV4) ?
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hashlimit_procdir4 : hashlimit_procdir6,
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&dl_file_ops, hinfo);
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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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setup_timer(&hinfo->timer, htable_gc, (unsigned long )hinfo);
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hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
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add_timer(&hinfo->timer);
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spin_lock_bh(&hashlimit_lock);
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hlist_add_head(&hinfo->node, &hashlimit_htables);
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spin_unlock_bh(&hashlimit_lock);
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return 0;
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}
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static int htable_create(struct xt_hashlimit_mtinfo1 *minfo, u_int8_t family)
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{
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struct xt_hashlimit_htable *hinfo;
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unsigned int size;
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unsigned int i;
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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 xt_hashlimit_htable) +
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sizeof(struct list_head) * size);
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if (hinfo == NULL) {
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printk(KERN_ERR "xt_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 == 0)
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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->use, 1);
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hinfo->count = 0;
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hinfo->family = family;
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hinfo->rnd_initialized = 0;
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spin_lock_init(&hinfo->lock);
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hinfo->pde = proc_create_data(minfo->name, 0,
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(family == NFPROTO_IPV4) ?
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hashlimit_procdir4 : hashlimit_procdir6,
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&dl_file_ops, hinfo);
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if (hinfo->pde == NULL) {
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vfree(hinfo);
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return -1;
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}
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setup_timer(&hinfo->timer, htable_gc, (unsigned long)hinfo);
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hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
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add_timer(&hinfo->timer);
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spin_lock_bh(&hashlimit_lock);
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hlist_add_head(&hinfo->node, &hashlimit_htables);
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spin_unlock_bh(&hashlimit_lock);
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return 0;
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}
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static bool select_all(const struct xt_hashlimit_htable *ht,
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const struct dsthash_ent *he)
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{
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return 1;
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}
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static bool select_gc(const struct xt_hashlimit_htable *ht,
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const struct dsthash_ent *he)
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{
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return time_after_eq(jiffies, he->expires);
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}
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static void htable_selective_cleanup(struct xt_hashlimit_htable *ht,
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bool (*select)(const struct xt_hashlimit_htable *ht,
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const struct dsthash_ent *he))
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{
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unsigned int i;
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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 xt_hashlimit_htable *ht = (struct xt_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 xt_hashlimit_htable *hinfo)
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{
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del_timer_sync(&hinfo->timer);
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/* remove proc entry */
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remove_proc_entry(hinfo->pde->name,
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hinfo->family == NFPROTO_IPV4 ? hashlimit_procdir4 :
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hashlimit_procdir6);
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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 xt_hashlimit_htable *htable_find_get(const char *name,
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u_int8_t family)
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{
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struct xt_hashlimit_htable *hinfo;
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struct hlist_node *pos;
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spin_lock_bh(&hashlimit_lock);
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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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hinfo->family == family) {
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atomic_inc(&hinfo->use);
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spin_unlock_bh(&hashlimit_lock);
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return hinfo;
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}
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}
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spin_unlock_bh(&hashlimit_lock);
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return NULL;
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}
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static void htable_put(struct xt_hashlimit_htable *hinfo)
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{
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if (atomic_dec_and_test(&hinfo->use)) {
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spin_lock_bh(&hashlimit_lock);
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hlist_del(&hinfo->node);
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spin_unlock_bh(&hashlimit_lock);
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htable_destroy(hinfo);
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}
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}
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/* The algorithm used is the Simple Token Bucket Filter (TBF)
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* see net/sched/sch_tbf.c in the linux source tree
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*/
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/* Rusty: This is my (non-mathematically-inclined) understanding of
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this algorithm. The `average rate' in jiffies becomes your initial
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amount of credit `credit' and the most credit you can ever have
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`credit_cap'. The `peak rate' becomes the cost of passing the
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test, `cost'.
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`prev' tracks the last packet hit: you gain one credit per jiffy.
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If you get credit balance more than this, the extra credit is
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discarded. Every time the match passes, you lose `cost' credits;
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if you don't have that many, the test fails.
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See Alexey's formal explanation in net/sched/sch_tbf.c.
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To get the maximum range, we multiply by this factor (ie. you get N
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credits per jiffy). We want to allow a rate as low as 1 per day
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(slowest userspace tool allows), which means
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CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32 ie.
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*/
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#define MAX_CPJ (0xFFFFFFFF / (HZ*60*60*24))
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/* Repeated shift and or gives us all 1s, final shift and add 1 gives
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* us the power of 2 below the theoretical max, so GCC simply does a
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* shift. */
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#define _POW2_BELOW2(x) ((x)|((x)>>1))
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#define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2))
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#define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4))
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#define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8))
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#define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16))
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#define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1)
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#define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ)
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/* Precision saver. */
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static inline u_int32_t
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user2credits(u_int32_t user)
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{
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/* If multiplying would overflow... */
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if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY))
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/* Divide first. */
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return (user / XT_HASHLIMIT_SCALE) * HZ * CREDITS_PER_JIFFY;
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return (user * HZ * CREDITS_PER_JIFFY) / XT_HASHLIMIT_SCALE;
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}
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static inline void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now)
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{
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dh->rateinfo.credit += (now - dh->rateinfo.prev) * CREDITS_PER_JIFFY;
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if (dh->rateinfo.credit > dh->rateinfo.credit_cap)
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dh->rateinfo.credit = dh->rateinfo.credit_cap;
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dh->rateinfo.prev = now;
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}
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static inline __be32 maskl(__be32 a, unsigned int l)
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{
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return l ? htonl(ntohl(a) & ~0 << (32 - l)) : 0;
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}
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#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
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static void hashlimit_ipv6_mask(__be32 *i, unsigned int p)
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{
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switch (p) {
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case 0 ... 31:
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i[0] = maskl(i[0], p);
|
|
i[1] = i[2] = i[3] = 0;
|
|
break;
|
|
case 32 ... 63:
|
|
i[1] = maskl(i[1], p - 32);
|
|
i[2] = i[3] = 0;
|
|
break;
|
|
case 64 ... 95:
|
|
i[2] = maskl(i[2], p - 64);
|
|
i[3] = 0;
|
|
case 96 ... 127:
|
|
i[3] = maskl(i[3], p - 96);
|
|
break;
|
|
case 128:
|
|
break;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
static int
|
|
hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo,
|
|
struct dsthash_dst *dst,
|
|
const struct sk_buff *skb, unsigned int protoff)
|
|
{
|
|
__be16 _ports[2], *ports;
|
|
u8 nexthdr;
|
|
|
|
memset(dst, 0, sizeof(*dst));
|
|
|
|
switch (hinfo->family) {
|
|
case NFPROTO_IPV4:
|
|
if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP)
|
|
dst->ip.dst = maskl(ip_hdr(skb)->daddr,
|
|
hinfo->cfg.dstmask);
|
|
if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP)
|
|
dst->ip.src = maskl(ip_hdr(skb)->saddr,
|
|
hinfo->cfg.srcmask);
|
|
|
|
if (!(hinfo->cfg.mode &
|
|
(XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT)))
|
|
return 0;
|
|
nexthdr = ip_hdr(skb)->protocol;
|
|
break;
|
|
#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
|
|
case NFPROTO_IPV6:
|
|
if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) {
|
|
memcpy(&dst->ip6.dst, &ipv6_hdr(skb)->daddr,
|
|
sizeof(dst->ip6.dst));
|
|
hashlimit_ipv6_mask(dst->ip6.dst, hinfo->cfg.dstmask);
|
|
}
|
|
if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) {
|
|
memcpy(&dst->ip6.src, &ipv6_hdr(skb)->saddr,
|
|
sizeof(dst->ip6.src));
|
|
hashlimit_ipv6_mask(dst->ip6.src, hinfo->cfg.srcmask);
|
|
}
|
|
|
|
if (!(hinfo->cfg.mode &
|
|
(XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT)))
|
|
return 0;
|
|
nexthdr = ipv6_hdr(skb)->nexthdr;
|
|
protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr);
|
|
if ((int)protoff < 0)
|
|
return -1;
|
|
break;
|
|
#endif
|
|
default:
|
|
BUG();
|
|
return 0;
|
|
}
|
|
|
|
switch (nexthdr) {
|
|
case IPPROTO_TCP:
|
|
case IPPROTO_UDP:
|
|
case IPPROTO_UDPLITE:
|
|
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 bool
|
|
hashlimit_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par)
|
|
{
|
|
const struct xt_hashlimit_info *r =
|
|
((const struct xt_hashlimit_info *)par->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, par->thoff) < 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 true;
|
|
}
|
|
|
|
spin_unlock_bh(&hinfo->lock);
|
|
|
|
/* default case: we're overlimit, thus don't match */
|
|
return false;
|
|
|
|
hotdrop:
|
|
*par->hotdrop = true;
|
|
return false;
|
|
}
|
|
|
|
static bool
|
|
hashlimit_mt(const struct sk_buff *skb, const struct xt_match_param *par)
|
|
{
|
|
const struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
|
|
struct xt_hashlimit_htable *hinfo = info->hinfo;
|
|
unsigned long now = jiffies;
|
|
struct dsthash_ent *dh;
|
|
struct dsthash_dst dst;
|
|
|
|
if (hashlimit_init_dst(hinfo, &dst, skb, par->thoff) < 0)
|
|
goto hotdrop;
|
|
|
|
spin_lock_bh(&hinfo->lock);
|
|
dh = dsthash_find(hinfo, &dst);
|
|
if (dh == NULL) {
|
|
dh = dsthash_alloc_init(hinfo, &dst);
|
|
if (dh == NULL) {
|
|
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) {
|
|
/* below the limit */
|
|
dh->rateinfo.credit -= dh->rateinfo.cost;
|
|
spin_unlock_bh(&hinfo->lock);
|
|
return !(info->cfg.mode & XT_HASHLIMIT_INVERT);
|
|
}
|
|
|
|
spin_unlock_bh(&hinfo->lock);
|
|
/* default match is underlimit - so over the limit, we need to invert */
|
|
return info->cfg.mode & XT_HASHLIMIT_INVERT;
|
|
|
|
hotdrop:
|
|
*par->hotdrop = true;
|
|
return false;
|
|
}
|
|
|
|
static bool hashlimit_mt_check_v0(const struct xt_mtchk_param *par)
|
|
{
|
|
struct xt_hashlimit_info *r = par->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 false;
|
|
}
|
|
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 false;
|
|
if (!r->cfg.gc_interval)
|
|
return false;
|
|
if (!r->cfg.expire)
|
|
return false;
|
|
if (r->name[sizeof(r->name) - 1] != '\0')
|
|
return false;
|
|
|
|
/* 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, par->match->family);
|
|
if (!r->hinfo && htable_create_v0(r, par->match->family) != 0) {
|
|
mutex_unlock(&hlimit_mutex);
|
|
return false;
|
|
}
|
|
mutex_unlock(&hlimit_mutex);
|
|
|
|
/* Ugly hack: For SMP, we only want to use one set */
|
|
r->u.master = r;
|
|
return true;
|
|
}
|
|
|
|
static bool hashlimit_mt_check(const struct xt_mtchk_param *par)
|
|
{
|
|
struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
|
|
|
|
/* Check for overflow. */
|
|
if (info->cfg.burst == 0 ||
|
|
user2credits(info->cfg.avg * info->cfg.burst) <
|
|
user2credits(info->cfg.avg)) {
|
|
printk(KERN_ERR "xt_hashlimit: overflow, try lower: %u/%u\n",
|
|
info->cfg.avg, info->cfg.burst);
|
|
return false;
|
|
}
|
|
if (info->cfg.gc_interval == 0 || info->cfg.expire == 0)
|
|
return false;
|
|
if (info->name[sizeof(info->name)-1] != '\0')
|
|
return false;
|
|
if (par->match->family == NFPROTO_IPV4) {
|
|
if (info->cfg.srcmask > 32 || info->cfg.dstmask > 32)
|
|
return false;
|
|
} else {
|
|
if (info->cfg.srcmask > 128 || info->cfg.dstmask > 128)
|
|
return false;
|
|
}
|
|
|
|
/* 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);
|
|
info->hinfo = htable_find_get(info->name, par->match->family);
|
|
if (!info->hinfo && htable_create(info, par->match->family) != 0) {
|
|
mutex_unlock(&hlimit_mutex);
|
|
return false;
|
|
}
|
|
mutex_unlock(&hlimit_mutex);
|
|
return true;
|
|
}
|
|
|
|
static void
|
|
hashlimit_mt_destroy_v0(const struct xt_mtdtor_param *par)
|
|
{
|
|
const struct xt_hashlimit_info *r = par->matchinfo;
|
|
|
|
htable_put(r->hinfo);
|
|
}
|
|
|
|
static void hashlimit_mt_destroy(const struct xt_mtdtor_param *par)
|
|
{
|
|
const struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
|
|
|
|
htable_put(info->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 hashlimit_mt_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 hashlimit_mt_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 hashlimit_mt_reg[] __read_mostly = {
|
|
{
|
|
.name = "hashlimit",
|
|
.revision = 0,
|
|
.family = NFPROTO_IPV4,
|
|
.match = hashlimit_mt_v0,
|
|
.matchsize = sizeof(struct xt_hashlimit_info),
|
|
#ifdef CONFIG_COMPAT
|
|
.compatsize = sizeof(struct compat_xt_hashlimit_info),
|
|
.compat_from_user = hashlimit_mt_compat_from_user,
|
|
.compat_to_user = hashlimit_mt_compat_to_user,
|
|
#endif
|
|
.checkentry = hashlimit_mt_check_v0,
|
|
.destroy = hashlimit_mt_destroy_v0,
|
|
.me = THIS_MODULE
|
|
},
|
|
{
|
|
.name = "hashlimit",
|
|
.revision = 1,
|
|
.family = NFPROTO_IPV4,
|
|
.match = hashlimit_mt,
|
|
.matchsize = sizeof(struct xt_hashlimit_mtinfo1),
|
|
.checkentry = hashlimit_mt_check,
|
|
.destroy = hashlimit_mt_destroy,
|
|
.me = THIS_MODULE,
|
|
},
|
|
#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
|
|
{
|
|
.name = "hashlimit",
|
|
.family = NFPROTO_IPV6,
|
|
.match = hashlimit_mt_v0,
|
|
.matchsize = sizeof(struct xt_hashlimit_info),
|
|
#ifdef CONFIG_COMPAT
|
|
.compatsize = sizeof(struct compat_xt_hashlimit_info),
|
|
.compat_from_user = hashlimit_mt_compat_from_user,
|
|
.compat_to_user = hashlimit_mt_compat_to_user,
|
|
#endif
|
|
.checkentry = hashlimit_mt_check_v0,
|
|
.destroy = hashlimit_mt_destroy_v0,
|
|
.me = THIS_MODULE
|
|
},
|
|
{
|
|
.name = "hashlimit",
|
|
.revision = 1,
|
|
.family = NFPROTO_IPV6,
|
|
.match = hashlimit_mt,
|
|
.matchsize = sizeof(struct xt_hashlimit_mtinfo1),
|
|
.checkentry = hashlimit_mt_check,
|
|
.destroy = hashlimit_mt_destroy,
|
|
.me = THIS_MODULE,
|
|
},
|
|
#endif
|
|
};
|
|
|
|
/* PROC stuff */
|
|
static void *dl_seq_start(struct seq_file *s, loff_t *pos)
|
|
__acquires(htable->lock)
|
|
{
|
|
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)
|
|
__releases(htable->lock)
|
|
{
|
|
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, u_int8_t family,
|
|
struct seq_file *s)
|
|
{
|
|
/* recalculate to show accurate numbers */
|
|
rateinfo_recalc(ent, jiffies);
|
|
|
|
switch (family) {
|
|
case NFPROTO_IPV4:
|
|
return seq_printf(s, "%ld %pI4:%u->%pI4:%u %u %u %u\n",
|
|
(long)(ent->expires - jiffies)/HZ,
|
|
&ent->dst.ip.src,
|
|
ntohs(ent->dst.src_port),
|
|
&ent->dst.ip.dst,
|
|
ntohs(ent->dst.dst_port),
|
|
ent->rateinfo.credit, ent->rateinfo.credit_cap,
|
|
ent->rateinfo.cost);
|
|
#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
|
|
case NFPROTO_IPV6:
|
|
return seq_printf(s, "%ld %pI6:%u->%pI6:%u %u %u %u\n",
|
|
(long)(ent->expires - jiffies)/HZ,
|
|
&ent->dst.ip6.src,
|
|
ntohs(ent->dst.src_port),
|
|
&ent->dst.ip6.dst,
|
|
ntohs(ent->dst.dst_port),
|
|
ent->rateinfo.credit, ent->rateinfo.credit_cap,
|
|
ent->rateinfo.cost);
|
|
#endif
|
|
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 const 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 const 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 hashlimit_mt_init(void)
|
|
{
|
|
int err;
|
|
|
|
err = xt_register_matches(hashlimit_mt_reg,
|
|
ARRAY_SIZE(hashlimit_mt_reg));
|
|
if (err < 0)
|
|
goto err1;
|
|
|
|
err = -ENOMEM;
|
|
hashlimit_cachep = kmem_cache_create("xt_hashlimit",
|
|
sizeof(struct dsthash_ent), 0, 0,
|
|
NULL);
|
|
if (!hashlimit_cachep) {
|
|
printk(KERN_ERR "xt_hashlimit: unable to create slab cache\n");
|
|
goto err2;
|
|
}
|
|
hashlimit_procdir4 = proc_mkdir("ipt_hashlimit", init_net.proc_net);
|
|
if (!hashlimit_procdir4) {
|
|
printk(KERN_ERR "xt_hashlimit: unable to create proc dir "
|
|
"entry\n");
|
|
goto err3;
|
|
}
|
|
err = 0;
|
|
#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
|
|
hashlimit_procdir6 = proc_mkdir("ip6t_hashlimit", init_net.proc_net);
|
|
if (!hashlimit_procdir6) {
|
|
printk(KERN_ERR "xt_hashlimit: unable to create proc dir "
|
|
"entry\n");
|
|
err = -ENOMEM;
|
|
}
|
|
#endif
|
|
if (!err)
|
|
return 0;
|
|
remove_proc_entry("ipt_hashlimit", init_net.proc_net);
|
|
err3:
|
|
kmem_cache_destroy(hashlimit_cachep);
|
|
err2:
|
|
xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
|
|
err1:
|
|
return err;
|
|
|
|
}
|
|
|
|
static void __exit hashlimit_mt_exit(void)
|
|
{
|
|
remove_proc_entry("ipt_hashlimit", init_net.proc_net);
|
|
#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
|
|
remove_proc_entry("ip6t_hashlimit", init_net.proc_net);
|
|
#endif
|
|
kmem_cache_destroy(hashlimit_cachep);
|
|
xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
|
|
}
|
|
|
|
module_init(hashlimit_mt_init);
|
|
module_exit(hashlimit_mt_exit);
|