netfilter: conntrack: use shared sysctl constants

Use shared sysctl variables for zero and one constants, as in commit
eec4844f ("proc/sysctl: add shared variables for range check")

Fixes: 8f14c99c ("netfilter: conntrack: limit sysctl setting for boolean options")
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_conntrack_standalone.c

@@ -511,8 +511,6 @@ static void nf_conntrack_standalone_fini_proc(struct net *net)
 /* Log invalid packets of a given protocol */
 static int log_invalid_proto_min __read_mostly;
 static int log_invalid_proto_max __read_mostly = 255;
-static int zero;
-static int one = 1;
 
 /* size the user *wants to set */
 static unsigned int nf_conntrack_htable_size_user __read_mostly;
@@ -629,8 +627,8 @@ static struct ctl_table nf_ct_sysctl_table[] = {
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec_minmax,
-		.extra1 	= &zero,
-		.extra2 	= &one,
+		.extra1 	= SYSCTL_ZERO,
+		.extra2 	= SYSCTL_ONE,
 	},
 	[NF_SYSCTL_CT_LOG_INVALID] = {
 		.procname	= "nf_conntrack_log_invalid",
@@ -654,8 +652,8 @@ static struct ctl_table nf_ct_sysctl_table[] = {
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec_minmax,
-		.extra1 	= &zero,
-		.extra2 	= &one,
+		.extra1 	= SYSCTL_ZERO,
+		.extra2 	= SYSCTL_ONE,
 	},
 	[NF_SYSCTL_CT_HELPER] = {
 		.procname	= "nf_conntrack_helper",
@@ -663,8 +661,8 @@ static struct ctl_table nf_ct_sysctl_table[] = {
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec_minmax,
-		.extra1 	= &zero,
-		.extra2 	= &one,
+		.extra1 	= SYSCTL_ZERO,
+		.extra2 	= SYSCTL_ONE,
 	},
 #ifdef CONFIG_NF_CONNTRACK_EVENTS
 	[NF_SYSCTL_CT_EVENTS] = {
@@ -673,8 +671,8 @@ static struct ctl_table nf_ct_sysctl_table[] = {
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec_minmax,
-		.extra1 	= &zero,
-		.extra2 	= &one,
+		.extra1 	= SYSCTL_ZERO,
+		.extra2 	= SYSCTL_ONE,
 	},
 #endif
 #ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
@@ -684,8 +682,8 @@ static struct ctl_table nf_ct_sysctl_table[] = {
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec_minmax,
-		.extra1 	= &zero,
-		.extra2 	= &one,
+		.extra1 	= SYSCTL_ZERO,
+		.extra2 	= SYSCTL_ONE,
 	},
 #endif
 	[NF_SYSCTL_CT_PROTO_TIMEOUT_GENERIC] = {
@@ -759,16 +757,16 @@ static struct ctl_table nf_ct_sysctl_table[] = {
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec_minmax,
-		.extra1 	= &zero,
-		.extra2 	= &one,
+		.extra1 	= SYSCTL_ZERO,
+		.extra2 	= SYSCTL_ONE,
 	},
 	[NF_SYSCTL_CT_PROTO_TCP_LIBERAL] = {
 		.procname       = "nf_conntrack_tcp_be_liberal",
 		.maxlen         = sizeof(int),
 		.mode           = 0644,
 		.proc_handler	= proc_dointvec_minmax,
-		.extra1 	= &zero,
-		.extra2 	= &one,
+		.extra1 	= SYSCTL_ZERO,
+		.extra2 	= SYSCTL_ONE,
 	},
 	[NF_SYSCTL_CT_PROTO_TCP_MAX_RETRANS] = {
 		.procname	= "nf_conntrack_tcp_max_retrans",
@@ -904,8 +902,8 @@ static struct ctl_table nf_ct_sysctl_table[] = {
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec_minmax,
-		.extra1 	= &zero,
-		.extra2 	= &one,
+		.extra1 	= SYSCTL_ZERO,
+		.extra2 	= SYSCTL_ONE,
 	},
 #endif
 #ifdef CONFIG_NF_CT_PROTO_GRE