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Message-Id: <1469272119-29942-8-git-send-email-pablo@netfilter.org>
Date: Sat, 23 Jul 2016 13:08:21 +0200
From: Pablo Neira Ayuso <pablo@...filter.org>
To: netfilter-devel@...r.kernel.org
Cc: davem@...emloft.net, netdev@...r.kernel.org
Subject: [PATCH 07/25] netfilter: nat: convert nat bysrc hash to rhashtable
From: Florian Westphal <fw@...len.de>
It did use a fixed-size bucket list plus single lock to protect add/del.
Unlike the main conntrack table we only need to add and remove keys.
Convert it to rhashtable to get table autosizing and per-bucket locking.
The maximum number of entries is -- as before -- tied to the number of
conntracks so we do not need another upperlimit.
The change does not handle rhashtable_remove_fast error, only possible
"error" is -ENOENT, and that is something that can happen legitimetely,
e.g. because nat module was inserted at a later time and no src manip
took place yet.
Tested with http-client-benchmark + httpterm with DNAT and SNAT rules
in place.
Signed-off-by: Florian Westphal <fw@...len.de>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
---
include/net/netfilter/nf_conntrack.h | 3 +-
include/net/netfilter/nf_nat.h | 1 +
net/netfilter/nf_nat_core.c | 126 +++++++++++++++++++----------------
3 files changed, 71 insertions(+), 59 deletions(-)
diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index e5135d8..a08825b 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -17,6 +17,7 @@
#include <linux/bitops.h>
#include <linux/compiler.h>
#include <linux/atomic.h>
+#include <linux/rhashtable.h>
#include <linux/netfilter/nf_conntrack_tcp.h>
#include <linux/netfilter/nf_conntrack_dccp.h>
@@ -118,7 +119,7 @@ struct nf_conn {
struct nf_ct_ext *ext;
#if IS_ENABLED(CONFIG_NF_NAT)
- struct hlist_node nat_bysource;
+ struct rhash_head nat_bysource;
#endif
/* Storage reserved for other modules, must be the last member */
union nf_conntrack_proto proto;
diff --git a/include/net/netfilter/nf_nat.h b/include/net/netfilter/nf_nat.h
index 02515f7..c327a43 100644
--- a/include/net/netfilter/nf_nat.h
+++ b/include/net/netfilter/nf_nat.h
@@ -1,5 +1,6 @@
#ifndef _NF_NAT_H
#define _NF_NAT_H
+#include <linux/rhashtable.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter/nf_nat.h>
#include <net/netfilter/nf_conntrack_tuple.h>
diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
index 6925347..de31818 100644
--- a/net/netfilter/nf_nat_core.c
+++ b/net/netfilter/nf_nat_core.c
@@ -30,17 +30,19 @@
#include <net/netfilter/nf_conntrack_zones.h>
#include <linux/netfilter/nf_nat.h>
-static DEFINE_SPINLOCK(nf_nat_lock);
-
static DEFINE_MUTEX(nf_nat_proto_mutex);
static const struct nf_nat_l3proto __rcu *nf_nat_l3protos[NFPROTO_NUMPROTO]
__read_mostly;
static const struct nf_nat_l4proto __rcu **nf_nat_l4protos[NFPROTO_NUMPROTO]
__read_mostly;
-static struct hlist_head *nf_nat_bysource __read_mostly;
-static unsigned int nf_nat_htable_size __read_mostly;
-static unsigned int nf_nat_hash_rnd __read_mostly;
+struct nf_nat_conn_key {
+ const struct net *net;
+ const struct nf_conntrack_tuple *tuple;
+ const struct nf_conntrack_zone *zone;
+};
+
+static struct rhashtable nf_nat_bysource_table;
inline const struct nf_nat_l3proto *
__nf_nat_l3proto_find(u8 family)
@@ -119,19 +121,17 @@ int nf_xfrm_me_harder(struct net *net, struct sk_buff *skb, unsigned int family)
EXPORT_SYMBOL(nf_xfrm_me_harder);
#endif /* CONFIG_XFRM */
-/* We keep an extra hash for each conntrack, for fast searching. */
-static inline unsigned int
-hash_by_src(const struct net *n, const struct nf_conntrack_tuple *tuple)
+static u32 nf_nat_bysource_hash(const void *data, u32 len, u32 seed)
{
- unsigned int hash;
-
- get_random_once(&nf_nat_hash_rnd, sizeof(nf_nat_hash_rnd));
+ const struct nf_conntrack_tuple *t;
+ const struct nf_conn *ct = data;
+ t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
/* Original src, to ensure we map it consistently if poss. */
- hash = jhash2((u32 *)&tuple->src, sizeof(tuple->src) / sizeof(u32),
- tuple->dst.protonum ^ nf_nat_hash_rnd ^ net_hash_mix(n));
- return reciprocal_scale(hash, nf_nat_htable_size);
+ seed ^= net_hash_mix(nf_ct_net(ct));
+ return jhash2((const u32 *)&t->src, sizeof(t->src) / sizeof(u32),
+ t->dst.protonum ^ seed);
}
/* Is this tuple already taken? (not by us) */
@@ -187,6 +187,26 @@ same_src(const struct nf_conn *ct,
t->src.u.all == tuple->src.u.all);
}
+static int nf_nat_bysource_cmp(struct rhashtable_compare_arg *arg,
+ const void *obj)
+{
+ const struct nf_nat_conn_key *key = arg->key;
+ const struct nf_conn *ct = obj;
+
+ return same_src(ct, key->tuple) &&
+ net_eq(nf_ct_net(ct), key->net) &&
+ nf_ct_zone_equal(ct, key->zone, IP_CT_DIR_ORIGINAL);
+}
+
+static struct rhashtable_params nf_nat_bysource_params = {
+ .head_offset = offsetof(struct nf_conn, nat_bysource),
+ .obj_hashfn = nf_nat_bysource_hash,
+ .obj_cmpfn = nf_nat_bysource_cmp,
+ .nelem_hint = 256,
+ .min_size = 1024,
+ .nulls_base = (1U << RHT_BASE_SHIFT),
+};
+
/* Only called for SRC manip */
static int
find_appropriate_src(struct net *net,
@@ -197,23 +217,23 @@ find_appropriate_src(struct net *net,
struct nf_conntrack_tuple *result,
const struct nf_nat_range *range)
{
- unsigned int h = hash_by_src(net, tuple);
const struct nf_conn *ct;
+ struct nf_nat_conn_key key = {
+ .net = net,
+ .tuple = tuple,
+ .zone = zone
+ };
- hlist_for_each_entry_rcu(ct, &nf_nat_bysource[h], nat_bysource) {
- if (same_src(ct, tuple) &&
- net_eq(net, nf_ct_net(ct)) &&
- nf_ct_zone_equal(ct, zone, IP_CT_DIR_ORIGINAL)) {
- /* Copy source part from reply tuple. */
- nf_ct_invert_tuplepr(result,
- &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
- result->dst = tuple->dst;
-
- if (in_range(l3proto, l4proto, result, range))
- return 1;
- }
- }
- return 0;
+ ct = rhashtable_lookup_fast(&nf_nat_bysource_table, &key,
+ nf_nat_bysource_params);
+ if (!ct)
+ return 0;
+
+ nf_ct_invert_tuplepr(result,
+ &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+ result->dst = tuple->dst;
+
+ return in_range(l3proto, l4proto, result, range);
}
/* For [FUTURE] fragmentation handling, we want the least-used
@@ -385,7 +405,6 @@ nf_nat_setup_info(struct nf_conn *ct,
const struct nf_nat_range *range,
enum nf_nat_manip_type maniptype)
{
- struct net *net = nf_ct_net(ct);
struct nf_conntrack_tuple curr_tuple, new_tuple;
struct nf_conn_nat *nat;
@@ -426,16 +445,13 @@ nf_nat_setup_info(struct nf_conn *ct,
}
if (maniptype == NF_NAT_MANIP_SRC) {
- unsigned int srchash;
-
- srchash = hash_by_src(net,
- &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
- spin_lock_bh(&nf_nat_lock);
- /* nf_conntrack_alter_reply might re-allocate extension aera */
- nat = nfct_nat(ct);
- hlist_add_head_rcu(&ct->nat_bysource,
- &nf_nat_bysource[srchash]);
- spin_unlock_bh(&nf_nat_lock);
+ int err;
+
+ err = rhashtable_insert_fast(&nf_nat_bysource_table,
+ &ct->nat_bysource,
+ nf_nat_bysource_params);
+ if (err)
+ return NF_DROP;
}
/* It's done. */
@@ -552,10 +568,10 @@ static int nf_nat_proto_clean(struct nf_conn *ct, void *data)
if (!del_timer(&ct->timeout))
return 1;
- spin_lock_bh(&nf_nat_lock);
- hlist_del_rcu(&ct->nat_bysource);
ct->status &= ~IPS_NAT_DONE_MASK;
- spin_unlock_bh(&nf_nat_lock);
+
+ rhashtable_remove_fast(&nf_nat_bysource_table, &ct->nat_bysource,
+ nf_nat_bysource_params);
add_timer(&ct->timeout);
@@ -687,11 +703,8 @@ static void nf_nat_cleanup_conntrack(struct nf_conn *ct)
if (!nat)
return;
- NF_CT_ASSERT(ct->status & IPS_SRC_NAT_DONE);
-
- spin_lock_bh(&nf_nat_lock);
- hlist_del_rcu(&ct->nat_bysource);
- spin_unlock_bh(&nf_nat_lock);
+ rhashtable_remove_fast(&nf_nat_bysource_table, &ct->nat_bysource,
+ nf_nat_bysource_params);
}
static struct nf_ct_ext_type nat_extend __read_mostly = {
@@ -826,16 +839,13 @@ static int __init nf_nat_init(void)
{
int ret;
- /* Leave them the same for the moment. */
- nf_nat_htable_size = nf_conntrack_htable_size;
-
- nf_nat_bysource = nf_ct_alloc_hashtable(&nf_nat_htable_size, 0);
- if (!nf_nat_bysource)
- return -ENOMEM;
+ ret = rhashtable_init(&nf_nat_bysource_table, &nf_nat_bysource_params);
+ if (ret)
+ return ret;
ret = nf_ct_extend_register(&nat_extend);
if (ret < 0) {
- nf_ct_free_hashtable(nf_nat_bysource, nf_nat_htable_size);
+ rhashtable_destroy(&nf_nat_bysource_table);
printk(KERN_ERR "nf_nat_core: Unable to register extension\n");
return ret;
}
@@ -859,7 +869,7 @@ static int __init nf_nat_init(void)
return 0;
cleanup_extend:
- nf_ct_free_hashtable(nf_nat_bysource, nf_nat_htable_size);
+ rhashtable_destroy(&nf_nat_bysource_table);
nf_ct_extend_unregister(&nat_extend);
return ret;
}
@@ -877,8 +887,8 @@ static void __exit nf_nat_cleanup(void)
#endif
for (i = 0; i < NFPROTO_NUMPROTO; i++)
kfree(nf_nat_l4protos[i]);
- synchronize_net();
- nf_ct_free_hashtable(nf_nat_bysource, nf_nat_htable_size);
+
+ rhashtable_destroy(&nf_nat_bysource_table);
}
MODULE_LICENSE("GPL");
--
2.1.4
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