From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: [PATCH 09/18] netfilter: add and use jump label for xt_tee
Date: Tue, 4 Aug 2015 12:02:39 +0200 [thread overview]
Message-ID: <1438682568-8346-10-git-send-email-pablo@netfilter.org> (raw)
In-Reply-To: <1438682568-8346-1-git-send-email-pablo@netfilter.org>
From: Florian Westphal <fw@strlen.de>
Don't bother testing if we need to switch to alternate stack
unless TEE target is used.
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
include/linux/netfilter/x_tables.h | 7 +++++++
net/ipv4/netfilter/ip_tables.c | 3 ++-
net/ipv6/netfilter/ip6_tables.c | 3 ++-
net/netfilter/x_tables.c | 3 +++
net/netfilter/xt_TEE.c | 2 ++
5 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index 1492845..b006b71 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -3,6 +3,7 @@
#include <linux/netdevice.h>
+#include <linux/static_key.h>
#include <uapi/linux/netfilter/x_tables.h>
/**
@@ -280,6 +281,12 @@ void xt_free_table_info(struct xt_table_info *info);
*/
DECLARE_PER_CPU(seqcount_t, xt_recseq);
+/* xt_tee_enabled - true if x_tables needs to handle reentrancy
+ *
+ * Enabled if current ip(6)tables ruleset has at least one -j TEE rule.
+ */
+extern struct static_key xt_tee_enabled;
+
/**
* xt_write_recseq_begin - start of a write section
*
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index a2e4b01..ff585bd 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -340,7 +340,8 @@ ipt_do_table(struct sk_buff *skb,
* For recursion via REJECT or SYNPROXY the stack will be clobbered
* but it is no problem since absolute verdict is issued by these.
*/
- jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated);
+ if (static_key_false(&xt_tee_enabled))
+ jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated);
e = get_entry(table_base, private->hook_entry[hook]);
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 531281f..ea6d105 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -366,7 +366,8 @@ ip6t_do_table(struct sk_buff *skb,
* For recursion via REJECT or SYNPROXY the stack will be clobbered
* but it is no problem since absolute verdict is issued by these.
*/
- jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated);
+ if (static_key_false(&xt_tee_enabled))
+ jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated);
e = get_entry(table_base, private->hook_entry[hook]);
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index 154447e..9b42b5e 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -727,6 +727,9 @@ EXPORT_SYMBOL_GPL(xt_compat_unlock);
DEFINE_PER_CPU(seqcount_t, xt_recseq);
EXPORT_PER_CPU_SYMBOL_GPL(xt_recseq);
+struct static_key xt_tee_enabled __read_mostly;
+EXPORT_SYMBOL_GPL(xt_tee_enabled);
+
static int xt_jumpstack_alloc(struct xt_table_info *i)
{
unsigned int size;
diff --git a/net/netfilter/xt_TEE.c b/net/netfilter/xt_TEE.c
index 8950e79..c5d6556 100644
--- a/net/netfilter/xt_TEE.c
+++ b/net/netfilter/xt_TEE.c
@@ -251,6 +251,7 @@ static int tee_tg_check(const struct xt_tgchk_param *par)
} else
info->priv = NULL;
+ static_key_slow_inc(&xt_tee_enabled);
return 0;
}
@@ -262,6 +263,7 @@ static void tee_tg_destroy(const struct xt_tgdtor_param *par)
unregister_netdevice_notifier(&info->priv->notifier);
kfree(info->priv);
}
+ static_key_slow_dec(&xt_tee_enabled);
}
static struct xt_target tee_tg_reg[] __read_mostly = {
--
1.7.10.4
next prev parent reply other threads:[~2015-08-04 9:57 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-04 10:02 [PATCH 00/18] Netfilter updates for net-next Pablo Neira Ayuso
2015-08-04 10:02 ` [PATCH 01/18] netfilter: kill nf_hooks_active Pablo Neira Ayuso
2015-08-04 10:02 ` [PATCH 02/18] netfilter: Simply the tests for enabling and disabling the ingress queue hook Pablo Neira Ayuso
2015-08-04 10:02 ` [PATCH 03/18] netfilter: Factor out the hook list selection from nf_register_hook Pablo Neira Ayuso
2015-08-04 10:02 ` [PATCH 04/18] netfilter: Per network namespace netfilter hooks Pablo Neira Ayuso
2015-08-04 10:02 ` [PATCH 05/18] netfilter: nftables: Only run the nftables chains in the proper netns Pablo Neira Ayuso
2015-08-04 10:02 ` [PATCH 06/18] netfilter: xtables: compute exact size needed for jumpstack Pablo Neira Ayuso
2015-08-04 10:02 ` [PATCH 07/18] netfilter: move tee_active to core Pablo Neira Ayuso
2015-08-04 10:02 ` [PATCH 08/18] netfilter: xtables: don't save/restore jumpstack offset Pablo Neira Ayuso
2015-08-04 10:02 ` Pablo Neira Ayuso [this message]
2015-08-04 10:02 ` [PATCH 10/18] netfilter: xtables: remove __pure annotation Pablo Neira Ayuso
2015-08-04 10:02 ` [PATCH 11/18] netfilter: Fix memory leak in nf_register_net_hook Pablo Neira Ayuso
2015-08-04 10:02 ` [PATCH 12/18] netfilter: nf_queue: fix nf_queue_nf_hook_drop() Pablo Neira Ayuso
2015-08-04 10:02 ` [PATCH 13/18] netfilter: fix possible removal of wrong hook Pablo Neira Ayuso
2015-08-04 10:02 ` [PATCH 14/18] netfilter: rename local nf_hook_list to hook_list Pablo Neira Ayuso
2015-08-04 10:02 ` [PATCH 15/18] netfilter: nf_ct_sctp: minimal multihoming support Pablo Neira Ayuso
2015-08-04 10:02 ` [PATCH 16/18] netfilter: bridge: reduce nf_bridge_info to 32 bytes again Pablo Neira Ayuso
2015-08-04 10:02 ` [PATCH 17/18] netfilter: bridge: do not initialize statics to 0 or NULL Pablo Neira Ayuso
2015-08-04 10:02 ` [PATCH 18/18] netfilter: ip6t_REJECT: Remove debug messages from reject_tg6() Pablo Neira Ayuso
2015-08-05 7:00 ` [PATCH 00/18] Netfilter updates for net-next David Miller
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