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-rw-r--r--net/netfilter/xt_hashlimit.c847
1 files changed, 847 insertions, 0 deletions
diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c
new file mode 100644
index 00000000..9228ee0d
--- /dev/null
+++ b/net/netfilter/xt_hashlimit.c
@@ -0,0 +1,847 @@
+/*
+ * xt_hashlimit - Netfilter module to limit the number of packets per time
+ * separately for each hashbucket (sourceip/sourceport/dstip/dstport)
+ *
+ * (C) 2003-2004 by Harald Welte <laforge@netfilter.org>
+ * Copyright © CC Computer Consultants GmbH, 2007 - 2008
+ *
+ * Development of this code was funded by Astaro AG, http://www.astaro.com/
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#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/mm.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
+#include <linux/ipv6.h>
+#include <net/ipv6.h>
+#endif
+
+#include <net/net_namespace.h>
+#include <net/netns/generic.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_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
+MODULE_DESCRIPTION("Xtables: per hash-bucket rate-limit match");
+MODULE_ALIAS("ipt_hashlimit");
+MODULE_ALIAS("ip6t_hashlimit");
+
+struct hashlimit_net {
+ struct hlist_head htables;
+ struct proc_dir_entry *ipt_hashlimit;
+ struct proc_dir_entry *ip6t_hashlimit;
+};
+
+static int hashlimit_net_id;
+static inline struct hashlimit_net *hashlimit_pernet(struct net *net)
+{
+ return net_generic(net, hashlimit_net_id);
+}
+
+/* need to declare this at the top */
+static const struct file_operations dl_file_ops;
+
+/* hash table crap */
+struct dsthash_dst {
+ union {
+ struct {
+ __be32 src;
+ __be32 dst;
+ } ip;
+#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
+ struct {
+ __be32 src[4];
+ __be32 dst[4];
+ } ip6;
+#endif
+ };
+ __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 */
+ spinlock_t lock;
+ unsigned long expires; /* precalculated expiry time */
+ struct {
+ unsigned long prev; /* last modification */
+ u_int32_t credit;
+ u_int32_t credit_cap, cost;
+ } rateinfo;
+ struct rcu_head rcu;
+};
+
+struct xt_hashlimit_htable {
+ struct hlist_node node; /* global list of all htables */
+ int use;
+ u_int8_t family;
+ bool rnd_initialized;
+
+ struct hashlimit_cfg1 cfg; /* config */
+
+ /* used internally */
+ spinlock_t lock; /* lock for list_head */
+ u_int32_t rnd; /* random seed for hash */
+ unsigned int count; /* number entries in table */
+ struct timer_list timer; /* timer for gc */
+
+ /* seq_file stuff */
+ struct proc_dir_entry *pde;
+ struct net *net;
+
+ struct hlist_head hash[0]; /* hashtable itself */
+};
+
+static DEFINE_MUTEX(hashlimit_mutex); /* protects htables list */
+static struct kmem_cache *hashlimit_cachep __read_mostly;
+
+static inline bool dst_cmp(const struct dsthash_ent *ent,
+ const 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)
+{
+ u_int32_t hash = jhash2((const u32 *)dst,
+ sizeof(*dst)/sizeof(u32),
+ ht->rnd);
+ /*
+ * Instead of returning hash % ht->cfg.size (implying a divide)
+ * we return the high 32 bits of the (hash * ht->cfg.size) that will
+ * give results between [0 and cfg.size-1] and same hash distribution,
+ * but using a multiply, less expensive than a divide
+ */
+ return ((u64)hash * ht->cfg.size) >> 32;
+}
+
+static struct dsthash_ent *
+dsthash_find(const struct xt_hashlimit_htable *ht,
+ const 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_rcu(ent, pos, &ht->hash[hash], node)
+ if (dst_cmp(ent, dst)) {
+ spin_lock(&ent->lock);
+ 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,
+ const struct dsthash_dst *dst)
+{
+ struct dsthash_ent *ent;
+
+ spin_lock(&ht->lock);
+ /* initialize hash with random val at the time we allocate
+ * the first hashtable entry */
+ if (unlikely(!ht->rnd_initialized)) {
+ get_random_bytes(&ht->rnd, sizeof(ht->rnd));
+ ht->rnd_initialized = true;
+ }
+
+ if (ht->cfg.max && ht->count >= ht->cfg.max) {
+ /* FIXME: do something. question is what.. */
+ if (net_ratelimit())
+ pr_err("max count of %u reached\n", ht->cfg.max);
+ ent = NULL;
+ } else
+ ent = kmem_cache_alloc(hashlimit_cachep, GFP_ATOMIC);
+ if (!ent) {
+ if (net_ratelimit())
+ pr_err("cannot allocate dsthash_ent\n");
+ } else {
+ memcpy(&ent->dst, dst, sizeof(ent->dst));
+ spin_lock_init(&ent->lock);
+
+ spin_lock(&ent->lock);
+ hlist_add_head_rcu(&ent->node, &ht->hash[hash_dst(ht, dst)]);
+ ht->count++;
+ }
+ spin_unlock(&ht->lock);
+ return ent;
+}
+
+static void dsthash_free_rcu(struct rcu_head *head)
+{
+ struct dsthash_ent *ent = container_of(head, struct dsthash_ent, rcu);
+
+ kmem_cache_free(hashlimit_cachep, ent);
+}
+
+static inline void
+dsthash_free(struct xt_hashlimit_htable *ht, struct dsthash_ent *ent)
+{
+ hlist_del_rcu(&ent->node);
+ call_rcu_bh(&ent->rcu, dsthash_free_rcu);
+ ht->count--;
+}
+static void htable_gc(unsigned long htlong);
+
+static int htable_create(struct net *net, struct xt_hashlimit_mtinfo1 *minfo,
+ u_int8_t family)
+{
+ struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
+ struct xt_hashlimit_htable *hinfo;
+ unsigned int size;
+ unsigned int i;
+
+ if (minfo->cfg.size) {
+ size = minfo->cfg.size;
+ } else {
+ size = (totalram_pages << PAGE_SHIFT) / 16384 /
+ sizeof(struct list_head);
+ if (totalram_pages > 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 == NULL)
+ return -ENOMEM;
+ 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 == 0)
+ 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]);
+
+ hinfo->use = 1;
+ hinfo->count = 0;
+ hinfo->family = family;
+ hinfo->rnd_initialized = false;
+ spin_lock_init(&hinfo->lock);
+
+ hinfo->pde = proc_create_data(minfo->name, 0,
+ (family == NFPROTO_IPV4) ?
+ hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit,
+ &dl_file_ops, hinfo);
+ if (hinfo->pde == NULL) {
+ vfree(hinfo);
+ return -ENOMEM;
+ }
+ hinfo->net = net;
+
+ setup_timer(&hinfo->timer, htable_gc, (unsigned long)hinfo);
+ hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
+ add_timer(&hinfo->timer);
+
+ hlist_add_head(&hinfo->node, &hashlimit_net->htables);
+
+ return 0;
+}
+
+static bool select_all(const struct xt_hashlimit_htable *ht,
+ const struct dsthash_ent *he)
+{
+ return 1;
+}
+
+static bool select_gc(const struct xt_hashlimit_htable *ht,
+ const struct dsthash_ent *he)
+{
+ return time_after_eq(jiffies, he->expires);
+}
+
+static void htable_selective_cleanup(struct xt_hashlimit_htable *ht,
+ bool (*select)(const struct xt_hashlimit_htable *ht,
+ const 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)
+{
+ struct hashlimit_net *hashlimit_net = hashlimit_pernet(hinfo->net);
+ struct proc_dir_entry *parent;
+
+ del_timer_sync(&hinfo->timer);
+
+ if (hinfo->family == NFPROTO_IPV4)
+ parent = hashlimit_net->ipt_hashlimit;
+ else
+ parent = hashlimit_net->ip6t_hashlimit;
+ remove_proc_entry(hinfo->pde->name, parent);
+ htable_selective_cleanup(hinfo, select_all);
+ vfree(hinfo);
+}
+
+static struct xt_hashlimit_htable *htable_find_get(struct net *net,
+ const char *name,
+ u_int8_t family)
+{
+ struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
+ struct xt_hashlimit_htable *hinfo;
+ struct hlist_node *pos;
+
+ hlist_for_each_entry(hinfo, pos, &hashlimit_net->htables, node) {
+ if (!strcmp(name, hinfo->pde->name) &&
+ hinfo->family == family) {
+ hinfo->use++;
+ return hinfo;
+ }
+ }
+ return NULL;
+}
+
+static void htable_put(struct xt_hashlimit_htable *hinfo)
+{
+ mutex_lock(&hashlimit_mutex);
+ if (--hinfo->use == 0) {
+ hlist_del(&hinfo->node);
+ htable_destroy(hinfo);
+ }
+ mutex_unlock(&hashlimit_mutex);
+}
+
+/* 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 inline __be32 maskl(__be32 a, unsigned int l)
+{
+ return l ? htonl(ntohl(a) & ~0 << (32 - l)) : 0;
+}
+
+#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
+static void hashlimit_ipv6_mask(__be32 *i, unsigned int p)
+{
+ switch (p) {
+ case 0 ... 31:
+ 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;
+ break;
+ 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;
+ int poff;
+
+ 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;
+ }
+
+ poff = proto_ports_offset(nexthdr);
+ if (poff >= 0) {
+ ports = skb_header_pointer(skb, protoff + poff, sizeof(_ports),
+ &_ports);
+ } else {
+ _ports[0] = _ports[1] = 0;
+ ports = _ports;
+ }
+ 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(const struct sk_buff *skb, struct xt_action_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;
+
+ rcu_read_lock_bh();
+ dh = dsthash_find(hinfo, &dst);
+ if (dh == NULL) {
+ dh = dsthash_alloc_init(hinfo, &dst);
+ if (dh == NULL) {
+ rcu_read_unlock_bh();
+ 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(&dh->lock);
+ rcu_read_unlock_bh();
+ return !(info->cfg.mode & XT_HASHLIMIT_INVERT);
+ }
+
+ spin_unlock(&dh->lock);
+ rcu_read_unlock_bh();
+ /* 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 int hashlimit_mt_check(const struct xt_mtchk_param *par)
+{
+ struct net *net = par->net;
+ struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
+ int ret;
+
+ /* Check for overflow. */
+ if (info->cfg.burst == 0 ||
+ user2credits(info->cfg.avg * info->cfg.burst) <
+ user2credits(info->cfg.avg)) {
+ pr_info("overflow, try lower: %u/%u\n",
+ info->cfg.avg, info->cfg.burst);
+ return -ERANGE;
+ }
+ if (info->cfg.gc_interval == 0 || info->cfg.expire == 0)
+ return -EINVAL;
+ if (info->name[sizeof(info->name)-1] != '\0')
+ return -EINVAL;
+ if (par->family == NFPROTO_IPV4) {
+ if (info->cfg.srcmask > 32 || info->cfg.dstmask > 32)
+ return -EINVAL;
+ } else {
+ if (info->cfg.srcmask > 128 || info->cfg.dstmask > 128)
+ return -EINVAL;
+ }
+
+ mutex_lock(&hashlimit_mutex);
+ info->hinfo = htable_find_get(net, info->name, par->family);
+ if (info->hinfo == NULL) {
+ ret = htable_create(net, info, par->family);
+ if (ret < 0) {
+ mutex_unlock(&hashlimit_mutex);
+ return ret;
+ }
+ }
+ mutex_unlock(&hashlimit_mutex);
+ return 0;
+}
+
+static void hashlimit_mt_destroy(const struct xt_mtdtor_param *par)
+{
+ const struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
+
+ htable_put(info->hinfo);
+}
+
+static struct xt_match hashlimit_mt_reg[] __read_mostly = {
+ {
+ .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",
+ .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 xt_hashlimit_htable *htable = s->private;
+ 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 xt_hashlimit_htable *htable = s->private;
+ 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 xt_hashlimit_htable *htable = s->private;
+ unsigned int *bucket = (unsigned int *)v;
+
+ if (!IS_ERR(bucket))
+ 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)
+{
+ int res;
+
+ spin_lock(&ent->lock);
+ /* recalculate to show accurate numbers */
+ rateinfo_recalc(ent, jiffies);
+
+ switch (family) {
+ case NFPROTO_IPV4:
+ res = 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);
+ break;
+#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
+ case NFPROTO_IPV6:
+ res = 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);
+ break;
+#endif
+ default:
+ BUG();
+ res = 0;
+ }
+ spin_unlock(&ent->lock);
+ return res;
+}
+
+static int dl_seq_show(struct seq_file *s, void *v)
+{
+ struct xt_hashlimit_htable *htable = s->private;
+ 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)->data;
+ }
+ 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 __net_init hashlimit_proc_net_init(struct net *net)
+{
+ struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
+
+ hashlimit_net->ipt_hashlimit = proc_mkdir("ipt_hashlimit", net->proc_net);
+ if (!hashlimit_net->ipt_hashlimit)
+ return -ENOMEM;
+#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
+ hashlimit_net->ip6t_hashlimit = proc_mkdir("ip6t_hashlimit", net->proc_net);
+ if (!hashlimit_net->ip6t_hashlimit) {
+ proc_net_remove(net, "ipt_hashlimit");
+ return -ENOMEM;
+ }
+#endif
+ return 0;
+}
+
+static void __net_exit hashlimit_proc_net_exit(struct net *net)
+{
+ proc_net_remove(net, "ipt_hashlimit");
+#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
+ proc_net_remove(net, "ip6t_hashlimit");
+#endif
+}
+
+static int __net_init hashlimit_net_init(struct net *net)
+{
+ struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
+
+ INIT_HLIST_HEAD(&hashlimit_net->htables);
+ return hashlimit_proc_net_init(net);
+}
+
+static void __net_exit hashlimit_net_exit(struct net *net)
+{
+ struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
+
+ BUG_ON(!hlist_empty(&hashlimit_net->htables));
+ hashlimit_proc_net_exit(net);
+}
+
+static struct pernet_operations hashlimit_net_ops = {
+ .init = hashlimit_net_init,
+ .exit = hashlimit_net_exit,
+ .id = &hashlimit_net_id,
+ .size = sizeof(struct hashlimit_net),
+};
+
+static int __init hashlimit_mt_init(void)
+{
+ int err;
+
+ err = register_pernet_subsys(&hashlimit_net_ops);
+ if (err < 0)
+ return 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) {
+ pr_warning("unable to create slab cache\n");
+ goto err2;
+ }
+ return 0;
+
+err2:
+ xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
+err1:
+ unregister_pernet_subsys(&hashlimit_net_ops);
+ return err;
+
+}
+
+static void __exit hashlimit_mt_exit(void)
+{
+ xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
+ unregister_pernet_subsys(&hashlimit_net_ops);
+
+ rcu_barrier_bh();
+ kmem_cache_destroy(hashlimit_cachep);
+}
+
+module_init(hashlimit_mt_init);
+module_exit(hashlimit_mt_exit);
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-06 22:58:55 +0000