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@xxxxxxxxx>
---
Changes since v4:
- remove leftover nf_ct_netns_put in xt_connlimit
Changes since v3:
- fix nf_conncount_modinit return value
Changes since v2:
- fix resource leak on kmalloc failure
in nf_conncount_init()
- add include guard in nf_conntrack_count.h
include/net/netfilter/nf_conntrack_count.h | 17 ++
include/uapi/linux/netfilter/xt_connlimit.h | 2 +-
net/netfilter/Kconfig | 3 +
net/netfilter/Makefile | 2 +
net/netfilter/nf_conncount.c | 373 ++++++++++++++++++++++++++++
net/netfilter/xt_connlimit.c | 369 ++-------------------------
6 files changed, 420 insertions(+), 346 deletions(-)
create mode 100644 include/net/netfilter/nf_conntrack_count.h
create mode 100644 net/netfilter/nf_conncount.c
diff --git a/include/net/netfilter/nf_conntrack_count.h b/include/net/netfilter/nf_conntrack_count.h
new file mode 100644
index 000000000000..adf8db44cf86
--- /dev/null
+++ b/include/net/netfilter/nf_conntrack_count.h
@@ -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
diff --git a/include/uapi/linux/netfilter/xt_connlimit.h b/include/uapi/linux/netfilter/xt_connlimit.h
index 07e5e9d47882..d4d1943dcd11 100644
--- a/include/uapi/linux/netfilter/xt_connlimit.h
+++ b/include/uapi/linux/netfilter/xt_connlimit.h
@@ -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 */
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index e4a13cc8a2e7..8a043b85fc07 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -62,6 +62,8 @@ config NF_LOG_NETDEV
select NF_LOG_COMMON
if NF_CONNTRACK
+config NETFILTER_CONNCOUNT
+ tristate
config NF_CONNTRACK_MARK
bool 'Connection mark tracking support'
@@ -1120,6 +1122,7 @@ 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).
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index f78ed2470831..490a55e7166d 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -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
diff --git a/net/netfilter/nf_conncount.c b/net/netfilter/nf_conncount.c
new file mode 100644
index 000000000000..a95518261168
--- /dev/null
+++ b/net/netfilter/nf_conncount.c
@@ -0,0 +1,373 @@
+/*
+ * count the number of connections matching an arbitrary key.
+ *
+ * (C) 2017 Red Hat GmbH
+ * Author: Florian Westphal <fw@xxxxxxxxx>
+ *
+ * split from xt_connlimit.c:
+ * (c) 2000 Gerd Knorr <kraxel@xxxxxxxxxxx>
+ * Nov 2002: Martin Bene <martin.bene@xxxxxxxxxxxxx>:
+ * 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@xxxxxxxxxx>");
+MODULE_AUTHOR("Florian Westphal <fw@xxxxxxxxx>");
+MODULE_DESCRIPTION("netfilter: count number of connections matching a key");
+MODULE_LICENSE("GPL");
diff --git a/net/netfilter/xt_connlimit.c b/net/netfilter/xt_connlimit.c
index a6214f235333..b1b17b9353e1 100644
--- a/net/netfilter/xt_connlimit.c
+++ b/net/netfilter/xt_connlimit.c
@@ -12,292 +12,30 @@
* GPL (C) 1999 Rusty Russell (rusty@xxxxxxxxxxxxxxx).
*/
#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);
--
2.13.6
--
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