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
Pablo Neira Ayuso
Родитель
c2f9eafee9
Коммит
625c556118
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@ -0,0 +1,17 @@
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#ifndef _NF_CONNTRACK_COUNT_H
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#define _NF_CONNTRACK_COUNT_H
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struct nf_conncount_data;
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struct nf_conncount_data *nf_conncount_init(struct net *net, unsigned int family,
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unsigned int keylen);
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void nf_conncount_destroy(struct net *net, unsigned int family,
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struct nf_conncount_data *data);
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unsigned int nf_conncount_count(struct net *net,
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struct nf_conncount_data *data,
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const u32 *key,
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unsigned int family,
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const struct nf_conntrack_tuple *tuple,
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const struct nf_conntrack_zone *zone);
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#endif
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@ -27,7 +27,7 @@ struct xt_connlimit_info {
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__u32 flags;
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/* Used internally by the kernel */
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struct xt_connlimit_data *data __attribute__((aligned(8)));
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struct nf_conncount_data *data __attribute__((aligned(8)));
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};
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#endif /* _XT_CONNLIMIT_H */
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@ -68,6 +68,8 @@ config NF_LOG_NETDEV
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select NF_LOG_COMMON
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if NF_CONNTRACK
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config NETFILTER_CONNCOUNT
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tristate
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config NF_CONNTRACK_MARK
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bool 'Connection mark tracking support'
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@ -1126,6 +1128,7 @@ config NETFILTER_XT_MATCH_CONNLIMIT
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tristate '"connlimit" match support'
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depends on NF_CONNTRACK
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depends on NETFILTER_ADVANCED
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select NETFILTER_CONNCOUNT
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---help---
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This match allows you to match against the number of parallel
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connections to a server per client IP address (or address block).
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@ -67,6 +67,8 @@ obj-$(CONFIG_NF_NAT_TFTP) += nf_nat_tftp.o
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# SYNPROXY
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obj-$(CONFIG_NETFILTER_SYNPROXY) += nf_synproxy_core.o
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obj-$(CONFIG_NETFILTER_CONNCOUNT) += nf_conncount.o
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# generic packet duplication from netdev family
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obj-$(CONFIG_NF_DUP_NETDEV) += nf_dup_netdev.o
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@ -0,0 +1,373 @@
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/*
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* count the number of connections matching an arbitrary key.
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*
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* (C) 2017 Red Hat GmbH
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* Author: Florian Westphal <fw@strlen.de>
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*
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* split from xt_connlimit.c:
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* (c) 2000 Gerd Knorr <kraxel@bytesex.org>
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* Nov 2002: Martin Bene <martin.bene@icomedias.com>:
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* only ignore TIME_WAIT or gone connections
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* (C) CC Computer Consultants GmbH, 2007
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/in.h>
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#include <linux/in6.h>
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#include <linux/ip.h>
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#include <linux/ipv6.h>
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#include <linux/jhash.h>
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#include <linux/slab.h>
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#include <linux/list.h>
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#include <linux/rbtree.h>
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#include <linux/module.h>
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#include <linux/random.h>
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#include <linux/skbuff.h>
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#include <linux/spinlock.h>
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#include <linux/netfilter/nf_conntrack_tcp.h>
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#include <linux/netfilter/x_tables.h>
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_count.h>
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#include <net/netfilter/nf_conntrack_core.h>
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#include <net/netfilter/nf_conntrack_tuple.h>
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#include <net/netfilter/nf_conntrack_zones.h>
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#define CONNCOUNT_SLOTS 256U
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#ifdef CONFIG_LOCKDEP
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#define CONNCOUNT_LOCK_SLOTS 8U
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#else
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#define CONNCOUNT_LOCK_SLOTS 256U
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#endif
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#define CONNCOUNT_GC_MAX_NODES 8
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#define MAX_KEYLEN 5
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/* we will save the tuples of all connections we care about */
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struct nf_conncount_tuple {
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struct hlist_node node;
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struct nf_conntrack_tuple tuple;
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};
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struct nf_conncount_rb {
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struct rb_node node;
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struct hlist_head hhead; /* connections/hosts in same subnet */
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u32 key[MAX_KEYLEN];
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};
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static spinlock_t nf_conncount_locks[CONNCOUNT_LOCK_SLOTS] __cacheline_aligned_in_smp;
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struct nf_conncount_data {
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unsigned int keylen;
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struct rb_root root[CONNCOUNT_SLOTS];
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};
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static u_int32_t conncount_rnd __read_mostly;
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static struct kmem_cache *conncount_rb_cachep __read_mostly;
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static struct kmem_cache *conncount_conn_cachep __read_mostly;
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static inline bool already_closed(const struct nf_conn *conn)
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{
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if (nf_ct_protonum(conn) == IPPROTO_TCP)
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return conn->proto.tcp.state == TCP_CONNTRACK_TIME_WAIT ||
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conn->proto.tcp.state == TCP_CONNTRACK_CLOSE;
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else
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return 0;
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}
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static int key_diff(const u32 *a, const u32 *b, unsigned int klen)
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{
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return memcmp(a, b, klen * sizeof(u32));
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}
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static bool add_hlist(struct hlist_head *head,
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const struct nf_conntrack_tuple *tuple)
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{
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struct nf_conncount_tuple *conn;
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conn = kmem_cache_alloc(conncount_conn_cachep, GFP_ATOMIC);
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if (conn == NULL)
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return false;
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conn->tuple = *tuple;
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hlist_add_head(&conn->node, head);
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return true;
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}
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static unsigned int check_hlist(struct net *net,
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struct hlist_head *head,
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const struct nf_conntrack_tuple *tuple,
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const struct nf_conntrack_zone *zone,
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bool *addit)
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{
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const struct nf_conntrack_tuple_hash *found;
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struct nf_conncount_tuple *conn;
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struct hlist_node *n;
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struct nf_conn *found_ct;
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unsigned int length = 0;
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*addit = true;
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/* check the saved connections */
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hlist_for_each_entry_safe(conn, n, head, node) {
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found = nf_conntrack_find_get(net, zone, &conn->tuple);
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if (found == NULL) {
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hlist_del(&conn->node);
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kmem_cache_free(conncount_conn_cachep, conn);
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continue;
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}
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found_ct = nf_ct_tuplehash_to_ctrack(found);
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if (nf_ct_tuple_equal(&conn->tuple, tuple)) {
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/*
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* Just to be sure we have it only once in the list.
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* We should not see tuples twice unless someone hooks
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* this into a table without "-p tcp --syn".
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*/
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*addit = false;
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} else if (already_closed(found_ct)) {
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/*
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* we do not care about connections which are
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* closed already -> ditch it
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*/
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nf_ct_put(found_ct);
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hlist_del(&conn->node);
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kmem_cache_free(conncount_conn_cachep, conn);
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continue;
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}
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nf_ct_put(found_ct);
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length++;
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}
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return length;
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}
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static void tree_nodes_free(struct rb_root *root,
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struct nf_conncount_rb *gc_nodes[],
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unsigned int gc_count)
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{
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struct nf_conncount_rb *rbconn;
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while (gc_count) {
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rbconn = gc_nodes[--gc_count];
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rb_erase(&rbconn->node, root);
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kmem_cache_free(conncount_rb_cachep, rbconn);
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}
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}
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static unsigned int
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count_tree(struct net *net, struct rb_root *root,
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const u32 *key, u8 keylen,
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u8 family,
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const struct nf_conntrack_tuple *tuple,
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const struct nf_conntrack_zone *zone)
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{
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struct nf_conncount_rb *gc_nodes[CONNCOUNT_GC_MAX_NODES];
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struct rb_node **rbnode, *parent;
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struct nf_conncount_rb *rbconn;
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struct nf_conncount_tuple *conn;
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unsigned int gc_count;
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bool no_gc = false;
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restart:
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gc_count = 0;
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parent = NULL;
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rbnode = &(root->rb_node);
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while (*rbnode) {
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int diff;
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bool addit;
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rbconn = rb_entry(*rbnode, struct nf_conncount_rb, node);
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parent = *rbnode;
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diff = key_diff(key, rbconn->key, keylen);
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if (diff < 0) {
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rbnode = &((*rbnode)->rb_left);
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} else if (diff > 0) {
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rbnode = &((*rbnode)->rb_right);
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} else {
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/* same source network -> be counted! */
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unsigned int count;
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count = check_hlist(net, &rbconn->hhead, tuple, zone, &addit);
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tree_nodes_free(root, gc_nodes, gc_count);
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if (!addit)
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return count;
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if (!add_hlist(&rbconn->hhead, tuple))
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return 0; /* hotdrop */
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return count + 1;
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}
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if (no_gc || gc_count >= ARRAY_SIZE(gc_nodes))
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continue;
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/* only used for GC on hhead, retval and 'addit' ignored */
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check_hlist(net, &rbconn->hhead, tuple, zone, &addit);
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if (hlist_empty(&rbconn->hhead))
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gc_nodes[gc_count++] = rbconn;
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}
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if (gc_count) {
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no_gc = true;
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tree_nodes_free(root, gc_nodes, gc_count);
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/* tree_node_free before new allocation permits
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* allocator to re-use newly free'd object.
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*
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* This is a rare event; in most cases we will find
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* existing node to re-use. (or gc_count is 0).
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*/
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goto restart;
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}
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/* no match, need to insert new node */
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rbconn = kmem_cache_alloc(conncount_rb_cachep, GFP_ATOMIC);
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if (rbconn == NULL)
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return 0;
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conn = kmem_cache_alloc(conncount_conn_cachep, GFP_ATOMIC);
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if (conn == NULL) {
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kmem_cache_free(conncount_rb_cachep, rbconn);
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return 0;
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}
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conn->tuple = *tuple;
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memcpy(rbconn->key, key, sizeof(u32) * keylen);
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INIT_HLIST_HEAD(&rbconn->hhead);
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hlist_add_head(&conn->node, &rbconn->hhead);
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rb_link_node(&rbconn->node, parent, rbnode);
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rb_insert_color(&rbconn->node, root);
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return 1;
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}
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unsigned int nf_conncount_count(struct net *net,
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struct nf_conncount_data *data,
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const u32 *key,
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unsigned int family,
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const struct nf_conntrack_tuple *tuple,
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const struct nf_conntrack_zone *zone)
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{
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struct rb_root *root;
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int count;
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u32 hash;
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hash = jhash2(key, data->keylen, conncount_rnd) % CONNCOUNT_SLOTS;
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root = &data->root[hash];
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spin_lock_bh(&nf_conncount_locks[hash % CONNCOUNT_LOCK_SLOTS]);
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count = count_tree(net, root, key, data->keylen, family, tuple, zone);
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spin_unlock_bh(&nf_conncount_locks[hash % CONNCOUNT_LOCK_SLOTS]);
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return count;
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}
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EXPORT_SYMBOL_GPL(nf_conncount_count);
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struct nf_conncount_data *nf_conncount_init(struct net *net, unsigned int family,
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unsigned int keylen)
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{
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struct nf_conncount_data *data;
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int ret, i;
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if (keylen % sizeof(u32) ||
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keylen / sizeof(u32) > MAX_KEYLEN ||
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keylen == 0)
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return ERR_PTR(-EINVAL);
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net_get_random_once(&conncount_rnd, sizeof(conncount_rnd));
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data = kmalloc(sizeof(*data), GFP_KERNEL);
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if (!data)
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return ERR_PTR(-ENOMEM);
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ret = nf_ct_netns_get(net, family);
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if (ret < 0) {
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kfree(data);
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return ERR_PTR(ret);
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}
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for (i = 0; i < ARRAY_SIZE(data->root); ++i)
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data->root[i] = RB_ROOT;
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data->keylen = keylen / sizeof(u32);
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return data;
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}
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EXPORT_SYMBOL_GPL(nf_conncount_init);
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static void destroy_tree(struct rb_root *r)
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{
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struct nf_conncount_tuple *conn;
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struct nf_conncount_rb *rbconn;
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struct hlist_node *n;
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struct rb_node *node;
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while ((node = rb_first(r)) != NULL) {
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rbconn = rb_entry(node, struct nf_conncount_rb, node);
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rb_erase(node, r);
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hlist_for_each_entry_safe(conn, n, &rbconn->hhead, node)
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kmem_cache_free(conncount_conn_cachep, conn);
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kmem_cache_free(conncount_rb_cachep, rbconn);
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}
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}
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void nf_conncount_destroy(struct net *net, unsigned int family,
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struct nf_conncount_data *data)
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{
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unsigned int i;
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nf_ct_netns_put(net, family);
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for (i = 0; i < ARRAY_SIZE(data->root); ++i)
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destroy_tree(&data->root[i]);
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kfree(data);
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}
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EXPORT_SYMBOL_GPL(nf_conncount_destroy);
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static int __init nf_conncount_modinit(void)
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{
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int i;
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BUILD_BUG_ON(CONNCOUNT_LOCK_SLOTS > CONNCOUNT_SLOTS);
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BUILD_BUG_ON((CONNCOUNT_SLOTS % CONNCOUNT_LOCK_SLOTS) != 0);
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for (i = 0; i < CONNCOUNT_LOCK_SLOTS; ++i)
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spin_lock_init(&nf_conncount_locks[i]);
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conncount_conn_cachep = kmem_cache_create("nf_conncount_tuple",
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sizeof(struct nf_conncount_tuple),
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0, 0, NULL);
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if (!conncount_conn_cachep)
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return -ENOMEM;
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conncount_rb_cachep = kmem_cache_create("nf_conncount_rb",
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sizeof(struct nf_conncount_rb),
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0, 0, NULL);
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if (!conncount_rb_cachep) {
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kmem_cache_destroy(conncount_conn_cachep);
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return -ENOMEM;
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}
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return 0;
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}
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static void __exit nf_conncount_modexit(void)
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{
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kmem_cache_destroy(conncount_conn_cachep);
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kmem_cache_destroy(conncount_rb_cachep);
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}
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|
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module_init(nf_conncount_modinit);
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module_exit(nf_conncount_modexit);
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MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
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MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
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MODULE_DESCRIPTION("netfilter: count number of connections matching a key");
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MODULE_LICENSE("GPL");
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|
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@ -12,292 +12,30 @@
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* GPL (C) 1999 Rusty Russell (rusty@rustcorp.com.au).
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*/
|
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
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#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);
|
||||
|
|
|
|||
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