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netfilter: connlimit: split xt_connlimit into front and backend 

This allows to reuse xt_connlimit infrastructure from nf_tables.
The upcoming nf_tables frontend can just pass in an nftables register
as input key, this allows limiting by any nft-supported key, including
concatenations.

For xt_connlimit, pass in the zone and the ip/ipv6 address.

With help from Yi-Hung Wei.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Yi-Hung Wei <yihung.wei@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Florian Westphal 2017-12-09 21:01:08 +01:00 committed by Pablo Neira Ayuso
parent c2f9eafee9
commit 625c556118
6 changed files with 420 additions and 346 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
include/net/netfilter/nf_conntrack_count.h Normal file
View File

@ -0,0 +1,17 @@
#ifndef _NF_CONNTRACK_COUNT_H
#define _NF_CONNTRACK_COUNT_H
struct nf_conncount_data;
struct nf_conncount_data *nf_conncount_init(struct net *net, unsigned int family,
unsigned int keylen);
void nf_conncount_destroy(struct net *net, unsigned int family,
struct nf_conncount_data *data);
unsigned int nf_conncount_count(struct net *net,
struct nf_conncount_data *data,
const u32 *key,
unsigned int family,
const struct nf_conntrack_tuple *tuple,
const struct nf_conntrack_zone *zone);
#endif

2
include/uapi/linux/netfilter/xt_connlimit.h
View File

@ -27,7 +27,7 @@ struct xt_connlimit_info {
__u32 flags;
/* Used internally by the kernel */
struct xt_connlimit_data *data __attribute__((aligned(8)));
struct nf_conncount_data *data __attribute__((aligned(8)));
};
#endif /* _XT_CONNLIMIT_H */

3
net/netfilter/Kconfig
View File

@ -68,6 +68,8 @@ config NF_LOG_NETDEV
select NF_LOG_COMMON
if NF_CONNTRACK
config NETFILTER_CONNCOUNT
tristate
config NF_CONNTRACK_MARK
bool 'Connection mark tracking support'
@ -1126,6 +1128,7 @@ config NETFILTER_XT_MATCH_CONNLIMIT
tristate '"connlimit" match support'
depends on NF_CONNTRACK
depends on NETFILTER_ADVANCED
select NETFILTER_CONNCOUNT
---help---
This match allows you to match against the number of parallel
connections to a server per client IP address (or address block).

2
net/netfilter/Makefile
View File

@ -67,6 +67,8 @@ obj-$(CONFIG_NF_NAT_TFTP) += nf_nat_tftp.o
# SYNPROXY
obj-$(CONFIG_NETFILTER_SYNPROXY) += nf_synproxy_core.o
obj-$(CONFIG_NETFILTER_CONNCOUNT) += nf_conncount.o
# generic packet duplication from netdev family
obj-$(CONFIG_NF_DUP_NETDEV) += nf_dup_netdev.o

373
net/netfilter/nf_conncount.c Normal file
View File

@ -0,0 +1,373 @@
/*
* count the number of connections matching an arbitrary key.
*
* (C) 2017 Red Hat GmbH
* Author: Florian Westphal <fw@strlen.de>
*
* split from xt_connlimit.c:
* (c) 2000 Gerd Knorr <kraxel@bytesex.org>
* Nov 2002: Martin Bene <martin.bene@icomedias.com>:
* only ignore TIME_WAIT or gone connections
* (C) CC Computer Consultants GmbH, 2007
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/jhash.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/rbtree.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/netfilter/nf_conntrack_tcp.h>
#include <linux/netfilter/x_tables.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_count.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_tuple.h>
#include <net/netfilter/nf_conntrack_zones.h>
#define CONNCOUNT_SLOTS 256U
#ifdef CONFIG_LOCKDEP
#define CONNCOUNT_LOCK_SLOTS 8U
#else
#define CONNCOUNT_LOCK_SLOTS 256U
#endif
#define CONNCOUNT_GC_MAX_NODES 8
#define MAX_KEYLEN 5
/* we will save the tuples of all connections we care about */
struct nf_conncount_tuple {
struct hlist_node node;
struct nf_conntrack_tuple tuple;
};
struct nf_conncount_rb {
struct rb_node node;
struct hlist_head hhead; /* connections/hosts in same subnet */
u32 key[MAX_KEYLEN];
};
static spinlock_t nf_conncount_locks[CONNCOUNT_LOCK_SLOTS] __cacheline_aligned_in_smp;
struct nf_conncount_data {
unsigned int keylen;
struct rb_root root[CONNCOUNT_SLOTS];
};
static u_int32_t conncount_rnd __read_mostly;
static struct kmem_cache *conncount_rb_cachep __read_mostly;
static struct kmem_cache *conncount_conn_cachep __read_mostly;
static inline bool already_closed(const struct nf_conn *conn)
{
if (nf_ct_protonum(conn) == IPPROTO_TCP)
return conn->proto.tcp.state == TCP_CONNTRACK_TIME_WAIT ||
conn->proto.tcp.state == TCP_CONNTRACK_CLOSE;
else
return 0;
}
static int key_diff(const u32 *a, const u32 *b, unsigned int klen)
{
return memcmp(a, b, klen * sizeof(u32));
}
static bool add_hlist(struct hlist_head *head,
const struct nf_conntrack_tuple *tuple)
{
struct nf_conncount_tuple *conn;
conn = kmem_cache_alloc(conncount_conn_cachep, GFP_ATOMIC);
if (conn == NULL)
return false;
conn->tuple = *tuple;
hlist_add_head(&conn->node, head);
return true;
}
static unsigned int check_hlist(struct net *net,
struct hlist_head *head,
const struct nf_conntrack_tuple *tuple,
const struct nf_conntrack_zone *zone,
bool *addit)
{
const struct nf_conntrack_tuple_hash *found;
struct nf_conncount_tuple *conn;
struct hlist_node *n;
struct nf_conn *found_ct;
unsigned int length = 0;
*addit = true;
/* check the saved connections */
hlist_for_each_entry_safe(conn, n, head, node) {
found = nf_conntrack_find_get(net, zone, &conn->tuple);
if (found == NULL) {
hlist_del(&conn->node);
kmem_cache_free(conncount_conn_cachep, conn);
continue;
}
found_ct = nf_ct_tuplehash_to_ctrack(found);
if (nf_ct_tuple_equal(&conn->tuple, tuple)) {
/*
* Just to be sure we have it only once in the list.
* We should not see tuples twice unless someone hooks
* this into a table without "-p tcp --syn".
*/
*addit = false;
} else if (already_closed(found_ct)) {
/*
* we do not care about connections which are
* closed already -> ditch it
*/
nf_ct_put(found_ct);
hlist_del(&conn->node);
kmem_cache_free(conncount_conn_cachep, conn);
continue;
}
nf_ct_put(found_ct);
length++;
}
return length;
}
static void tree_nodes_free(struct rb_root *root,
struct nf_conncount_rb *gc_nodes[],
unsigned int gc_count)
{
struct nf_conncount_rb *rbconn;
while (gc_count) {
rbconn = gc_nodes[--gc_count];
rb_erase(&rbconn->node, root);
kmem_cache_free(conncount_rb_cachep, rbconn);
}
}
static unsigned int
count_tree(struct net *net, struct rb_root *root,
const u32 *key, u8 keylen,
u8 family,
const struct nf_conntrack_tuple *tuple,
const struct nf_conntrack_zone *zone)
{
struct nf_conncount_rb *gc_nodes[CONNCOUNT_GC_MAX_NODES];
struct rb_node **rbnode, *parent;
struct nf_conncount_rb *rbconn;
struct nf_conncount_tuple *conn;
unsigned int gc_count;
bool no_gc = false;
restart:
gc_count = 0;
parent = NULL;
rbnode = &(root->rb_node);
while (*rbnode) {
int diff;
bool addit;
rbconn = rb_entry(*rbnode, struct nf_conncount_rb, node);
parent = *rbnode;
diff = key_diff(key, rbconn->key, keylen);
if (diff < 0) {
rbnode = &((*rbnode)->rb_left);
} else if (diff > 0) {
rbnode = &((*rbnode)->rb_right);
} else {
/* same source network -> be counted! */
unsigned int count;
count = check_hlist(net, &rbconn->hhead, tuple, zone, &addit);
tree_nodes_free(root, gc_nodes, gc_count);
if (!addit)
return count;
if (!add_hlist(&rbconn->hhead, tuple))
return 0; /* hotdrop */
return count + 1;
}
if (no_gc || gc_count >= ARRAY_SIZE(gc_nodes))
continue;
/* only used for GC on hhead, retval and 'addit' ignored */
check_hlist(net, &rbconn->hhead, tuple, zone, &addit);
if (hlist_empty(&rbconn->hhead))
gc_nodes[gc_count++] = rbconn;
}
if (gc_count) {
no_gc = true;
tree_nodes_free(root, gc_nodes, gc_count);
/* tree_node_free before new allocation permits
* allocator to re-use newly free'd object.
*
* This is a rare event; in most cases we will find
* existing node to re-use. (or gc_count is 0).
*/
goto restart;
}
/* no match, need to insert new node */
rbconn = kmem_cache_alloc(conncount_rb_cachep, GFP_ATOMIC);
if (rbconn == NULL)
return 0;
conn = kmem_cache_alloc(conncount_conn_cachep, GFP_ATOMIC);
if (conn == NULL) {
kmem_cache_free(conncount_rb_cachep, rbconn);
return 0;
}
conn->tuple = *tuple;
memcpy(rbconn->key, key, sizeof(u32) * keylen);
INIT_HLIST_HEAD(&rbconn->hhead);
hlist_add_head(&conn->node, &rbconn->hhead);
rb_link_node(&rbconn->node, parent, rbnode);
rb_insert_color(&rbconn->node, root);
return 1;
}
unsigned int nf_conncount_count(struct net *net,
struct nf_conncount_data *data,
const u32 *key,
unsigned int family,
const struct nf_conntrack_tuple *tuple,
const struct nf_conntrack_zone *zone)
{
struct rb_root *root;
int count;
u32 hash;
hash = jhash2(key, data->keylen, conncount_rnd) % CONNCOUNT_SLOTS;
root = &data->root[hash];
spin_lock_bh(&nf_conncount_locks[hash % CONNCOUNT_LOCK_SLOTS]);
count = count_tree(net, root, key, data->keylen, family, tuple, zone);
spin_unlock_bh(&nf_conncount_locks[hash % CONNCOUNT_LOCK_SLOTS]);
return count;
}
EXPORT_SYMBOL_GPL(nf_conncount_count);
struct nf_conncount_data *nf_conncount_init(struct net *net, unsigned int family,
unsigned int keylen)
{
struct nf_conncount_data *data;
int ret, i;
if (keylen % sizeof(u32) ||
keylen / sizeof(u32) > MAX_KEYLEN ||
keylen == 0)
return ERR_PTR(-EINVAL);
net_get_random_once(&conncount_rnd, sizeof(conncount_rnd));
data = kmalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return ERR_PTR(-ENOMEM);
ret = nf_ct_netns_get(net, family);
if (ret < 0) {
kfree(data);
return ERR_PTR(ret);
}
for (i = 0; i < ARRAY_SIZE(data->root); ++i)
data->root[i] = RB_ROOT;
data->keylen = keylen / sizeof(u32);
return data;
}
EXPORT_SYMBOL_GPL(nf_conncount_init);
static void destroy_tree(struct rb_root *r)
{
struct nf_conncount_tuple *conn;
struct nf_conncount_rb *rbconn;
struct hlist_node *n;
struct rb_node *node;
while ((node = rb_first(r)) != NULL) {
rbconn = rb_entry(node, struct nf_conncount_rb, node);
rb_erase(node, r);
hlist_for_each_entry_safe(conn, n, &rbconn->hhead, node)
kmem_cache_free(conncount_conn_cachep, conn);
kmem_cache_free(conncount_rb_cachep, rbconn);
}
}
void nf_conncount_destroy(struct net *net, unsigned int family,
struct nf_conncount_data *data)
{
unsigned int i;
nf_ct_netns_put(net, family);
for (i = 0; i < ARRAY_SIZE(data->root); ++i)
destroy_tree(&data->root[i]);
kfree(data);
}
EXPORT_SYMBOL_GPL(nf_conncount_destroy);
static int __init nf_conncount_modinit(void)
{
int i;
BUILD_BUG_ON(CONNCOUNT_LOCK_SLOTS > CONNCOUNT_SLOTS);
BUILD_BUG_ON((CONNCOUNT_SLOTS % CONNCOUNT_LOCK_SLOTS) != 0);
for (i = 0; i < CONNCOUNT_LOCK_SLOTS; ++i)
spin_lock_init(&nf_conncount_locks[i]);
conncount_conn_cachep = kmem_cache_create("nf_conncount_tuple",
sizeof(struct nf_conncount_tuple),
0, 0, NULL);
if (!conncount_conn_cachep)
return -ENOMEM;
conncount_rb_cachep = kmem_cache_create("nf_conncount_rb",
sizeof(struct nf_conncount_rb),
0, 0, NULL);
if (!conncount_rb_cachep) {
kmem_cache_destroy(conncount_conn_cachep);
return -ENOMEM;
}
return 0;
}
static void __exit nf_conncount_modexit(void)
{
kmem_cache_destroy(conncount_conn_cachep);
kmem_cache_destroy(conncount_rb_cachep);
}
module_init(nf_conncount_modinit);
module_exit(nf_conncount_modexit);
MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
MODULE_DESCRIPTION("netfilter: count number of connections matching a key");
MODULE_LICENSE("GPL");

369
net/netfilter/xt_connlimit.c
View File

@ -12,292 +12,30 @@
* GPL (C) 1999 Rusty Russell (rusty@rustcorp.com.au).
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/jhash.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/rbtree.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/netfilter/nf_conntrack_tcp.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_connlimit.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_tuple.h>
#include <net/netfilter/nf_conntrack_zones.h>
#define CONNLIMIT_SLOTS 256U
#ifdef CONFIG_LOCKDEP
#define CONNLIMIT_LOCK_SLOTS 8U
#else
#define CONNLIMIT_LOCK_SLOTS 256U
#endif
#define CONNLIMIT_GC_MAX_NODES 8
/* we will save the tuples of all connections we care about */
struct xt_connlimit_conn {
struct hlist_node node;
struct nf_conntrack_tuple tuple;
};
struct xt_connlimit_rb {
struct rb_node node;
struct hlist_head hhead; /* connections/hosts in same subnet */
union nf_inet_addr addr; /* search key */
};
static spinlock_t xt_connlimit_locks[CONNLIMIT_LOCK_SLOTS] __cacheline_aligned_in_smp;
struct xt_connlimit_data {
struct rb_root climit_root[CONNLIMIT_SLOTS];
};
static u_int32_t connlimit_rnd __read_mostly;
static struct kmem_cache *connlimit_rb_cachep __read_mostly;
static struct kmem_cache *connlimit_conn_cachep __read_mostly;
static inline unsigned int connlimit_iphash(__be32 addr)
{
return jhash_1word((__force __u32)addr,
connlimit_rnd) % CONNLIMIT_SLOTS;
}
static inline unsigned int
connlimit_iphash6(const union nf_inet_addr *addr)
{
return jhash2((u32 *)addr->ip6, ARRAY_SIZE(addr->ip6),
connlimit_rnd) % CONNLIMIT_SLOTS;
}
static inline bool already_closed(const struct nf_conn *conn)
{
if (nf_ct_protonum(conn) == IPPROTO_TCP)
return conn->proto.tcp.state == TCP_CONNTRACK_TIME_WAIT ||
conn->proto.tcp.state == TCP_CONNTRACK_CLOSE;
else
return 0;
}
static int
same_source(const union nf_inet_addr *addr,
const union nf_inet_addr *u3, u_int8_t family)
{
if (family == NFPROTO_IPV4)
return ntohl(addr->ip) - ntohl(u3->ip);
return memcmp(addr->ip6, u3->ip6, sizeof(addr->ip6));
}
static bool add_hlist(struct hlist_head *head,
const struct nf_conntrack_tuple *tuple,
const union nf_inet_addr *addr)
{
struct xt_connlimit_conn *conn;
conn = kmem_cache_alloc(connlimit_conn_cachep, GFP_ATOMIC);
if (conn == NULL)
return false;
conn->tuple = *tuple;
hlist_add_head(&conn->node, head);
return true;
}
static unsigned int check_hlist(struct net *net,
struct hlist_head *head,
const struct nf_conntrack_tuple *tuple,
const struct nf_conntrack_zone *zone,
bool *addit)
{
const struct nf_conntrack_tuple_hash *found;
struct xt_connlimit_conn *conn;
struct hlist_node *n;
struct nf_conn *found_ct;
unsigned int length = 0;
*addit = true;
/* check the saved connections */
hlist_for_each_entry_safe(conn, n, head, node) {
found = nf_conntrack_find_get(net, zone, &conn->tuple);
if (found == NULL) {
hlist_del(&conn->node);
kmem_cache_free(connlimit_conn_cachep, conn);
continue;
}
found_ct = nf_ct_tuplehash_to_ctrack(found);
if (nf_ct_tuple_equal(&conn->tuple, tuple)) {
/*
* Just to be sure we have it only once in the list.
* We should not see tuples twice unless someone hooks
* this into a table without "-p tcp --syn".
*/
*addit = false;
} else if (already_closed(found_ct)) {
/*
* we do not care about connections which are
* closed already -> ditch it
*/
nf_ct_put(found_ct);
hlist_del(&conn->node);
kmem_cache_free(connlimit_conn_cachep, conn);
continue;
}
nf_ct_put(found_ct);
length++;
}
return length;
}
static void tree_nodes_free(struct rb_root *root,
struct xt_connlimit_rb *gc_nodes[],
unsigned int gc_count)
{
struct xt_connlimit_rb *rbconn;
while (gc_count) {
rbconn = gc_nodes[--gc_count];
rb_erase(&rbconn->node, root);
kmem_cache_free(connlimit_rb_cachep, rbconn);
}
}
static unsigned int
count_tree(struct net *net, struct rb_root *root,
const struct nf_conntrack_tuple *tuple,
const union nf_inet_addr *addr,
u8 family, const struct nf_conntrack_zone *zone)
{
struct xt_connlimit_rb *gc_nodes[CONNLIMIT_GC_MAX_NODES];
struct rb_node **rbnode, *parent;
struct xt_connlimit_rb *rbconn;
struct xt_connlimit_conn *conn;
unsigned int gc_count;
bool no_gc = false;
restart:
gc_count = 0;
parent = NULL;
rbnode = &(root->rb_node);
while (*rbnode) {
int diff;
bool addit;
rbconn = rb_entry(*rbnode, struct xt_connlimit_rb, node);
parent = *rbnode;
diff = same_source(addr, &rbconn->addr, family);
if (diff < 0) {
rbnode = &((*rbnode)->rb_left);
} else if (diff > 0) {
rbnode = &((*rbnode)->rb_right);
} else {
/* same source network -> be counted! */
unsigned int count;
count = check_hlist(net, &rbconn->hhead, tuple, zone, &addit);
tree_nodes_free(root, gc_nodes, gc_count);
if (!addit)
return count;
if (!add_hlist(&rbconn->hhead, tuple, addr))
return 0; /* hotdrop */
return count + 1;
}
if (no_gc || gc_count >= ARRAY_SIZE(gc_nodes))
continue;
/* only used for GC on hhead, retval and 'addit' ignored */
check_hlist(net, &rbconn->hhead, tuple, zone, &addit);
if (hlist_empty(&rbconn->hhead))
gc_nodes[gc_count++] = rbconn;
}
if (gc_count) {
no_gc = true;
tree_nodes_free(root, gc_nodes, gc_count);
/* tree_node_free before new allocation permits
* allocator to re-use newly free'd object.
*
* This is a rare event; in most cases we will find
* existing node to re-use. (or gc_count is 0).
*/
goto restart;
}
/* no match, need to insert new node */
rbconn = kmem_cache_alloc(connlimit_rb_cachep, GFP_ATOMIC);
if (rbconn == NULL)
return 0;
conn = kmem_cache_alloc(connlimit_conn_cachep, GFP_ATOMIC);
if (conn == NULL) {
kmem_cache_free(connlimit_rb_cachep, rbconn);
return 0;
}
conn->tuple = *tuple;
rbconn->addr = *addr;
INIT_HLIST_HEAD(&rbconn->hhead);
hlist_add_head(&conn->node, &rbconn->hhead);
rb_link_node(&rbconn->node, parent, rbnode);
rb_insert_color(&rbconn->node, root);
return 1;
}
static int count_them(struct net *net,
struct xt_connlimit_data *data,
const struct nf_conntrack_tuple *tuple,
const union nf_inet_addr *addr,
u_int8_t family,
const struct nf_conntrack_zone *zone)
{
struct rb_root *root;
int count;
u32 hash;
if (family == NFPROTO_IPV6)
hash = connlimit_iphash6(addr);
else
hash = connlimit_iphash(addr->ip);
root = &data->climit_root[hash];
spin_lock_bh(&xt_connlimit_locks[hash % CONNLIMIT_LOCK_SLOTS]);
count = count_tree(net, root, tuple, addr, family, zone);
spin_unlock_bh(&xt_connlimit_locks[hash % CONNLIMIT_LOCK_SLOTS]);
return count;
}
#include <net/netfilter/nf_conntrack_count.h>
static bool
connlimit_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
struct net *net = xt_net(par);
const struct xt_connlimit_info *info = par->matchinfo;
union nf_inet_addr addr;
struct nf_conntrack_tuple tuple;
const struct nf_conntrack_tuple *tuple_ptr = &tuple;
const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
enum ip_conntrack_info ctinfo;
const struct nf_conn *ct;
unsigned int connections;
u32 key[5];
ct = nf_ct_get(skb, &ctinfo);
if (ct != NULL) {
@ -310,6 +48,7 @@ connlimit_mt(const struct sk_buff *skb, struct xt_action_param *par)
if (xt_family(par) == NFPROTO_IPV6) {
const struct ipv6hdr *iph = ipv6_hdr(skb);
union nf_inet_addr addr;
unsigned int i;
memcpy(&addr.ip6, (info->flags & XT_CONNLIMIT_DADDR) ?
@ -317,22 +56,24 @@ connlimit_mt(const struct sk_buff *skb, struct xt_action_param *par)
for (i = 0; i < ARRAY_SIZE(addr.ip6); ++i)
addr.ip6[i] &= info->mask.ip6[i];
memcpy(key, &addr, sizeof(addr.ip6));
key[4] = zone->id;
} else {
const struct iphdr *iph = ip_hdr(skb);
addr.ip = (info->flags & XT_CONNLIMIT_DADDR) ?
key[0] = (info->flags & XT_CONNLIMIT_DADDR) ?
iph->daddr : iph->saddr;
addr.ip &= info->mask.ip;
key[0] &= info->mask.ip;
key[1] = zone->id;
}
connections = count_them(net, info->data, tuple_ptr, &addr,
xt_family(par), zone);
connections = nf_conncount_count(net, info->data, key,
xt_family(par), tuple_ptr, zone);
if (connections == 0)
/* kmalloc failed, drop it entirely */
goto hotdrop;
return (connections > info->limit) ^
!!(info->flags & XT_CONNLIMIT_INVERT);
return (connections > info->limit) ^ !!(info->flags & XT_CONNLIMIT_INVERT);
hotdrop:
par->hotdrop = true;
@ -342,61 +83,27 @@ connlimit_mt(const struct sk_buff *skb, struct xt_action_param *par)
static int connlimit_mt_check(const struct xt_mtchk_param *par)
{
struct xt_connlimit_info *info = par->matchinfo;
unsigned int i;
int ret;
unsigned int keylen;
net_get_random_once(&connlimit_rnd, sizeof(connlimit_rnd));
ret = nf_ct_netns_get(par->net, par->family);
if (ret < 0) {
pr_info("cannot load conntrack support for "
"address family %u\n", par->family);
return ret;
}
keylen = sizeof(u32);
if (par->family == NFPROTO_IPV6)
keylen += sizeof(struct in6_addr);
else
keylen += sizeof(struct in_addr);
/* init private data */
info->data = kmalloc(sizeof(struct xt_connlimit_data), GFP_KERNEL);
if (info->data == NULL) {
nf_ct_netns_put(par->net, par->family);
return -ENOMEM;
}
for (i = 0; i < ARRAY_SIZE(info->data->climit_root); ++i)
info->data->climit_root[i] = RB_ROOT;
info->data = nf_conncount_init(par->net, par->family, keylen);
if (IS_ERR(info->data))
return PTR_ERR(info->data);
return 0;
}
static void destroy_tree(struct rb_root *r)
{
struct xt_connlimit_conn *conn;
struct xt_connlimit_rb *rbconn;
struct hlist_node *n;
struct rb_node *node;
while ((node = rb_first(r)) != NULL) {
rbconn = rb_entry(node, struct xt_connlimit_rb, node);
rb_erase(node, r);
hlist_for_each_entry_safe(conn, n, &rbconn->hhead, node)
kmem_cache_free(connlimit_conn_cachep, conn);
kmem_cache_free(connlimit_rb_cachep, rbconn);
}
}
static void connlimit_mt_destroy(const struct xt_mtdtor_param *par)
{
const struct xt_connlimit_info *info = par->matchinfo;
unsigned int i;
nf_ct_netns_put(par->net, par->family);
for (i = 0; i < ARRAY_SIZE(info->data->climit_root); ++i)
destroy_tree(&info->data->climit_root[i]);
kfree(info->data);
nf_conncount_destroy(par->net, par->family, info->data);
}
static struct xt_match connlimit_mt_reg __read_mostly = {
@ -413,40 +120,12 @@ static struct xt_match connlimit_mt_reg __read_mostly = {
static int __init connlimit_mt_init(void)
{
int ret, i;
BUILD_BUG_ON(CONNLIMIT_LOCK_SLOTS > CONNLIMIT_SLOTS);
BUILD_BUG_ON((CONNLIMIT_SLOTS % CONNLIMIT_LOCK_SLOTS) != 0);
for (i = 0; i < CONNLIMIT_LOCK_SLOTS; ++i)
spin_lock_init(&xt_connlimit_locks[i]);
connlimit_conn_cachep = kmem_cache_create("xt_connlimit_conn",
sizeof(struct xt_connlimit_conn),
0, 0, NULL);
if (!connlimit_conn_cachep)
return -ENOMEM;
connlimit_rb_cachep = kmem_cache_create("xt_connlimit_rb",
sizeof(struct xt_connlimit_rb),
0, 0, NULL);
if (!connlimit_rb_cachep) {
kmem_cache_destroy(connlimit_conn_cachep);
return -ENOMEM;
}
ret = xt_register_match(&connlimit_mt_reg);
if (ret != 0) {
kmem_cache_destroy(connlimit_conn_cachep);
kmem_cache_destroy(connlimit_rb_cachep);
}
return ret;
return xt_register_match(&connlimit_mt_reg);
}
static void __exit connlimit_mt_exit(void)
{
xt_unregister_match(&connlimit_mt_reg);
kmem_cache_destroy(connlimit_conn_cachep);
kmem_cache_destroy(connlimit_rb_cachep);
}
module_init(connlimit_mt_init);