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Date: Mon, 1 May 2017 12:47:03 +0200
From: Pablo Neira Ayuso <pablo@...filter.org>
To: netfilter-devel@...r.kernel.org
Cc: davem@...emloft.net, netdev@...r.kernel.org
Subject: [PATCH 36/53] netfilter: synproxy: only register hooks when needed
From: Florian Westphal <fw@...len.de>
Defer registration of the synproxy hooks until the first SYNPROXY rule is
added. Also means we only register hooks in namespaces that need it.
Signed-off-by: Florian Westphal <fw@...len.de>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
---
include/net/netfilter/nf_conntrack_synproxy.h | 2 +
net/ipv4/netfilter/ipt_SYNPROXY.c | 73 ++++++++++++++-------------
net/ipv6/netfilter/ip6t_SYNPROXY.c | 73 ++++++++++++++-------------
3 files changed, 80 insertions(+), 68 deletions(-)
diff --git a/include/net/netfilter/nf_conntrack_synproxy.h b/include/net/netfilter/nf_conntrack_synproxy.h
index b0ca402c1f72..a2fcb5271726 100644
--- a/include/net/netfilter/nf_conntrack_synproxy.h
+++ b/include/net/netfilter/nf_conntrack_synproxy.h
@@ -52,6 +52,8 @@ struct synproxy_stats {
struct synproxy_net {
struct nf_conn *tmpl;
struct synproxy_stats __percpu *stats;
+ unsigned int hook_ref4;
+ unsigned int hook_ref6;
};
extern unsigned int synproxy_net_id;
diff --git a/net/ipv4/netfilter/ipt_SYNPROXY.c b/net/ipv4/netfilter/ipt_SYNPROXY.c
index 3240a2614e82..c308ee0ee0bc 100644
--- a/net/ipv4/netfilter/ipt_SYNPROXY.c
+++ b/net/ipv4/netfilter/ipt_SYNPROXY.c
@@ -409,19 +409,56 @@ static unsigned int ipv4_synproxy_hook(void *priv,
return NF_ACCEPT;
}
+static struct nf_hook_ops ipv4_synproxy_ops[] __read_mostly = {
+ {
+ .hook = ipv4_synproxy_hook,
+ .pf = NFPROTO_IPV4,
+ .hooknum = NF_INET_LOCAL_IN,
+ .priority = NF_IP_PRI_CONNTRACK_CONFIRM - 1,
+ },
+ {
+ .hook = ipv4_synproxy_hook,
+ .pf = NFPROTO_IPV4,
+ .hooknum = NF_INET_POST_ROUTING,
+ .priority = NF_IP_PRI_CONNTRACK_CONFIRM - 1,
+ },
+};
+
static int synproxy_tg4_check(const struct xt_tgchk_param *par)
{
+ struct synproxy_net *snet = synproxy_pernet(par->net);
const struct ipt_entry *e = par->entryinfo;
+ int err;
if (e->ip.proto != IPPROTO_TCP ||
e->ip.invflags & XT_INV_PROTO)
return -EINVAL;
- return nf_ct_netns_get(par->net, par->family);
+ err = nf_ct_netns_get(par->net, par->family);
+ if (err)
+ return err;
+
+ if (snet->hook_ref4 == 0) {
+ err = nf_register_net_hooks(par->net, ipv4_synproxy_ops,
+ ARRAY_SIZE(ipv4_synproxy_ops));
+ if (err) {
+ nf_ct_netns_put(par->net, par->family);
+ return err;
+ }
+ }
+
+ snet->hook_ref4++;
+ return err;
}
static void synproxy_tg4_destroy(const struct xt_tgdtor_param *par)
{
+ struct synproxy_net *snet = synproxy_pernet(par->net);
+
+ snet->hook_ref4--;
+ if (snet->hook_ref4 == 0)
+ nf_unregister_net_hooks(par->net, ipv4_synproxy_ops,
+ ARRAY_SIZE(ipv4_synproxy_ops));
nf_ct_netns_put(par->net, par->family);
}
@@ -436,46 +473,14 @@ static struct xt_target synproxy_tg4_reg __read_mostly = {
.me = THIS_MODULE,
};
-static struct nf_hook_ops ipv4_synproxy_ops[] __read_mostly = {
- {
- .hook = ipv4_synproxy_hook,
- .pf = NFPROTO_IPV4,
- .hooknum = NF_INET_LOCAL_IN,
- .priority = NF_IP_PRI_CONNTRACK_CONFIRM - 1,
- },
- {
- .hook = ipv4_synproxy_hook,
- .pf = NFPROTO_IPV4,
- .hooknum = NF_INET_POST_ROUTING,
- .priority = NF_IP_PRI_CONNTRACK_CONFIRM - 1,
- },
-};
-
static int __init synproxy_tg4_init(void)
{
- int err;
-
- err = nf_register_hooks(ipv4_synproxy_ops,
- ARRAY_SIZE(ipv4_synproxy_ops));
- if (err < 0)
- goto err1;
-
- err = xt_register_target(&synproxy_tg4_reg);
- if (err < 0)
- goto err2;
-
- return 0;
-
-err2:
- nf_unregister_hooks(ipv4_synproxy_ops, ARRAY_SIZE(ipv4_synproxy_ops));
-err1:
- return err;
+ return xt_register_target(&synproxy_tg4_reg);
}
static void __exit synproxy_tg4_exit(void)
{
xt_unregister_target(&synproxy_tg4_reg);
- nf_unregister_hooks(ipv4_synproxy_ops, ARRAY_SIZE(ipv4_synproxy_ops));
}
module_init(synproxy_tg4_init);
diff --git a/net/ipv6/netfilter/ip6t_SYNPROXY.c b/net/ipv6/netfilter/ip6t_SYNPROXY.c
index 4ef1ddd4bbbd..1252537f215f 100644
--- a/net/ipv6/netfilter/ip6t_SYNPROXY.c
+++ b/net/ipv6/netfilter/ip6t_SYNPROXY.c
@@ -430,20 +430,57 @@ static unsigned int ipv6_synproxy_hook(void *priv,
return NF_ACCEPT;
}
+static struct nf_hook_ops ipv6_synproxy_ops[] __read_mostly = {
+ {
+ .hook = ipv6_synproxy_hook,
+ .pf = NFPROTO_IPV6,
+ .hooknum = NF_INET_LOCAL_IN,
+ .priority = NF_IP_PRI_CONNTRACK_CONFIRM - 1,
+ },
+ {
+ .hook = ipv6_synproxy_hook,
+ .pf = NFPROTO_IPV6,
+ .hooknum = NF_INET_POST_ROUTING,
+ .priority = NF_IP_PRI_CONNTRACK_CONFIRM - 1,
+ },
+};
+
static int synproxy_tg6_check(const struct xt_tgchk_param *par)
{
+ struct synproxy_net *snet = synproxy_pernet(par->net);
const struct ip6t_entry *e = par->entryinfo;
+ int err;
if (!(e->ipv6.flags & IP6T_F_PROTO) ||
e->ipv6.proto != IPPROTO_TCP ||
e->ipv6.invflags & XT_INV_PROTO)
return -EINVAL;
- return nf_ct_netns_get(par->net, par->family);
+ err = nf_ct_netns_get(par->net, par->family);
+ if (err)
+ return err;
+
+ if (snet->hook_ref6 == 0) {
+ err = nf_register_net_hooks(par->net, ipv6_synproxy_ops,
+ ARRAY_SIZE(ipv6_synproxy_ops));
+ if (err) {
+ nf_ct_netns_put(par->net, par->family);
+ return err;
+ }
+ }
+
+ snet->hook_ref6++;
+ return err;
}
static void synproxy_tg6_destroy(const struct xt_tgdtor_param *par)
{
+ struct synproxy_net *snet = synproxy_pernet(par->net);
+
+ snet->hook_ref6--;
+ if (snet->hook_ref6 == 0)
+ nf_unregister_net_hooks(par->net, ipv6_synproxy_ops,
+ ARRAY_SIZE(ipv6_synproxy_ops));
nf_ct_netns_put(par->net, par->family);
}
@@ -458,46 +495,14 @@ static struct xt_target synproxy_tg6_reg __read_mostly = {
.me = THIS_MODULE,
};
-static struct nf_hook_ops ipv6_synproxy_ops[] __read_mostly = {
- {
- .hook = ipv6_synproxy_hook,
- .pf = NFPROTO_IPV6,
- .hooknum = NF_INET_LOCAL_IN,
- .priority = NF_IP_PRI_CONNTRACK_CONFIRM - 1,
- },
- {
- .hook = ipv6_synproxy_hook,
- .pf = NFPROTO_IPV6,
- .hooknum = NF_INET_POST_ROUTING,
- .priority = NF_IP_PRI_CONNTRACK_CONFIRM - 1,
- },
-};
-
static int __init synproxy_tg6_init(void)
{
- int err;
-
- err = nf_register_hooks(ipv6_synproxy_ops,
- ARRAY_SIZE(ipv6_synproxy_ops));
- if (err < 0)
- goto err1;
-
- err = xt_register_target(&synproxy_tg6_reg);
- if (err < 0)
- goto err2;
-
- return 0;
-
-err2:
- nf_unregister_hooks(ipv6_synproxy_ops, ARRAY_SIZE(ipv6_synproxy_ops));
-err1:
- return err;
+ return xt_register_target(&synproxy_tg6_reg);
}
static void __exit synproxy_tg6_exit(void)
{
xt_unregister_target(&synproxy_tg6_reg);
- nf_unregister_hooks(ipv6_synproxy_ops, ARRAY_SIZE(ipv6_synproxy_ops));
}
module_init(synproxy_tg6_init);
--
2.1.4
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