[NETFILTER]: nf_conntrack: sysctl compatibility with old connection tracking

This patch adds an option to keep the connection tracking sysctls visible
under their old names.

Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
index c59f281..46aa44a 100644
--- a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
+++ b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
@@ -336,6 +336,21 @@
 		.ctl_name = 0
 	}
 };
+#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
+static struct ctl_table icmp_compat_sysctl_table[] = {
+	{
+		.ctl_name	= NET_IPV4_NF_CONNTRACK_ICMP_TIMEOUT,
+		.procname	= "ip_conntrack_icmp_timeout",
+		.data		= &nf_ct_icmp_timeout,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_jiffies,
+	},
+        {
+		.ctl_name = 0
+	}
+};
+#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
 #endif /* CONFIG_SYSCTL */
 
 struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp =
@@ -360,6 +375,9 @@
 #ifdef CONFIG_SYSCTL
 	.ctl_table_header	= &icmp_sysctl_header,
 	.ctl_table		= icmp_sysctl_table,
+#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
+	.ctl_compat_table	= icmp_compat_sysctl_table,
+#endif
 #endif
 };