[CRIU] [PATCH rh7] netfilter: Restore xt_connlimit version 0

[Kirill Tkhai]

Restore revision 0 dispite it's called obsolete and
removed from vanila kernel:

  commit 68c07cb6d8aa05daf38ab47d5bb674d81a2066fb
  Author: Cong Wang <xiyou.wangcong at gmail.com>
  Date:   Sat May 19 04:39:01 2012 +0000

RH6 containers with old userspace need it and we
don't want to upset their users.

https://jira.sw.ru/browse/PSBM-40186

Signed-off-by: Kirill Tkhai <ktkhai at odin.com>
---
 include/uapi/linux/netfilter/xt_connlimit.h |    9 +++++--
 net/netfilter/xt_connlimit.c                |   35 +++++++++++++++++++--------
 2 files changed, 31 insertions(+), 13 deletions(-)

diff --git a/include/uapi/linux/netfilter/xt_connlimit.h b/include/uapi/linux/netfilter/xt_connlimit.h
index f165609..d1366f0 100644
--- a/include/uapi/linux/netfilter/xt_connlimit.h
+++ b/include/uapi/linux/netfilter/xt_connlimit.h
@@ -22,8 +22,13 @@ struct xt_connlimit_info {
 #endif
 	};
 	unsigned int limit;
-	/* revision 1 */
-	__u32 flags;
+	union {
+		/* revision 0 */
+		unsigned int inverse;
+
+		/* revision 1 */
+		__u32 flags;
+	};
 
 	/* Used internally by the kernel */
 	struct xt_connlimit_data *data __attribute__((aligned(8)));
diff --git a/net/netfilter/xt_connlimit.c b/net/netfilter/xt_connlimit.c
index fbc66bb..34aa0ba 100644
--- a/net/netfilter/xt_connlimit.c
+++ b/net/netfilter/xt_connlimit.c
@@ -426,15 +426,27 @@ static void connlimit_mt_destroy(const struct xt_mtdtor_param *par)
 	kfree(info->data);
 }
 
-static struct xt_match connlimit_mt_reg __read_mostly = {
-	.name       = "connlimit",
-	.revision   = 1,
-	.family     = NFPROTO_UNSPEC,
-	.checkentry = connlimit_mt_check,
-	.match      = connlimit_mt,
-	.matchsize  = sizeof(struct xt_connlimit_info),
-	.destroy    = connlimit_mt_destroy,
-	.me         = THIS_MODULE,
+static struct xt_match connlimit_mt_reg[] __read_mostly = {
+	{
+		.name		= "connlimit",
+		.revision	= 0,
+		.family		= NFPROTO_UNSPEC,
+		.checkentry	= connlimit_mt_check,
+		.match		= connlimit_mt,
+		.matchsize	= sizeof(struct xt_connlimit_info),
+		.destroy	= connlimit_mt_destroy,
+		.me		= THIS_MODULE,
+	},
+	{
+		.name		= "connlimit",
+		.revision	= 1,
+		.family		= NFPROTO_UNSPEC,
+		.checkentry	= connlimit_mt_check,
+		.match		= connlimit_mt,
+		.matchsize	= sizeof(struct xt_connlimit_info),
+		.destroy	= connlimit_mt_destroy,
+		.me		= THIS_MODULE,
+	},
 };
 
 static int __init connlimit_mt_init(void)
@@ -460,7 +472,8 @@ static int __init connlimit_mt_init(void)
 		kmem_cache_destroy(connlimit_conn_cachep);
 		return -ENOMEM;
 	}
-	ret = xt_register_match(&connlimit_mt_reg);
+	ret = xt_register_matches(connlimit_mt_reg,
+	      ARRAY_SIZE(connlimit_mt_reg));
 	if (ret != 0) {
 		kmem_cache_destroy(connlimit_conn_cachep);
 		kmem_cache_destroy(connlimit_rb_cachep);
@@ -470,7 +483,7 @@ static int __init connlimit_mt_init(void)
 
 static void __exit connlimit_mt_exit(void)
 {
-	xt_unregister_match(&connlimit_mt_reg);
+	xt_unregister_matches(connlimit_mt_reg, ARRAY_SIZE(connlimit_mt_reg));
 	kmem_cache_destroy(connlimit_conn_cachep);
 	kmem_cache_destroy(connlimit_rb_cachep);
 }