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authorFlorian Westphal <fw@strlen.de>2015-07-14 17:51:09 +0200
committerPablo Neira Ayuso <pablo@netfilter.org>2015-07-15 18:18:06 +0200
commitdcebd3153e0a7749bb054ab73fa4e1ca33e9d3f9 (patch)
treeb962b7b1bca5b3c8272781c991a9878fdfe4e880 /net
parentnetfilter: xtables: don't save/restore jumpstack offset (diff)
downloadlinux-dcebd3153e0a7749bb054ab73fa4e1ca33e9d3f9.tar.xz
linux-dcebd3153e0a7749bb054ab73fa4e1ca33e9d3f9.zip
netfilter: add and use jump label for xt_tee
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>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/netfilter/ip_tables.c3
-rw-r--r--net/ipv6/netfilter/ip6_tables.c3
-rw-r--r--net/netfilter/x_tables.c3
-rw-r--r--net/netfilter/xt_TEE.c2
4 files changed, 9 insertions, 2 deletions
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index a2e4b018a254..ff585bdbf850 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 531281f0ff86..ea6d105063c2 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 154447e519ab..9b42b5ea6dcd 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 8950e79c4dc9..c5d6556dbc5e 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 = {