/* 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;
        [NF_SYSCTL_CT_CHECKSUM] = {
                .procname       = "nf_conntrack_checksum",
                .data           = &init_net.ct.sysctl_checksum,
-               .maxlen         = sizeof(unsigned int),
+               .maxlen         = sizeof(int),
                .mode           = 0644,
-               .proc_handler   = proc_dointvec,
+               .proc_handler   = proc_dointvec_minmax,
+               .extra1         = &zero,
+               .extra2         = &one,
        },
        [NF_SYSCTL_CT_LOG_INVALID] = {
                .procname       = "nf_conntrack_log_invalid",
        [NF_SYSCTL_CT_ACCT] = {
                .procname       = "nf_conntrack_acct",
                .data           = &init_net.ct.sysctl_acct,
-               .maxlen         = sizeof(unsigned int),
+               .maxlen         = sizeof(int),
                .mode           = 0644,
-               .proc_handler   = proc_dointvec,
+               .proc_handler   = proc_dointvec_minmax,
+               .extra1         = &zero,
+               .extra2         = &one,
        },
        [NF_SYSCTL_CT_HELPER] = {
                .procname       = "nf_conntrack_helper",
                .data           = &init_net.ct.sysctl_auto_assign_helper,
-               .maxlen         = sizeof(unsigned int),
+               .maxlen         = sizeof(int),
                .mode           = 0644,
-               .proc_handler   = proc_dointvec,
+               .proc_handler   = proc_dointvec_minmax,
+               .extra1         = &zero,
+               .extra2         = &one,
        },
 #ifdef CONFIG_NF_CONNTRACK_EVENTS
        [NF_SYSCTL_CT_EVENTS] = {
                .procname       = "nf_conntrack_events",
                .data           = &init_net.ct.sysctl_events,
-               .maxlen         = sizeof(unsigned int),
+               .maxlen         = sizeof(int),
                .mode           = 0644,
-               .proc_handler   = proc_dointvec,
+               .proc_handler   = proc_dointvec_minmax,
+               .extra1         = &zero,
+               .extra2         = &one,
        },
 #endif
 #ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
        [NF_SYSCTL_CT_TIMESTAMP] = {
                .procname       = "nf_conntrack_timestamp",
                .data           = &init_net.ct.sysctl_tstamp,
-               .maxlen         = sizeof(unsigned int),
+               .maxlen         = sizeof(int),
                .mode           = 0644,
-               .proc_handler   = proc_dointvec,
+               .proc_handler   = proc_dointvec_minmax,
+               .extra1         = &zero,
+               .extra2         = &one,
        },
 #endif
        [NF_SYSCTL_CT_PROTO_TIMEOUT_GENERIC] = {
        },
        [NF_SYSCTL_CT_PROTO_TCP_LOOSE] = {
                .procname       = "nf_conntrack_tcp_loose",
-               .maxlen         = sizeof(unsigned int),
+               .maxlen         = sizeof(int),
                .mode           = 0644,
-               .proc_handler   = proc_dointvec,
+               .proc_handler   = proc_dointvec_minmax,
+               .extra1         = &zero,
+               .extra2         = &one,
        },
        [NF_SYSCTL_CT_PROTO_TCP_LIBERAL] = {
                .procname       = "nf_conntrack_tcp_be_liberal",
-               .maxlen         = sizeof(unsigned int),
+               .maxlen         = sizeof(int),
                .mode           = 0644,
-               .proc_handler   = proc_dointvec,
+               .proc_handler   = proc_dointvec_minmax,
+               .extra1         = &zero,
+               .extra2         = &one,
        },
        [NF_SYSCTL_CT_PROTO_TCP_MAX_RETRANS] = {
                .procname       = "nf_conntrack_tcp_max_retrans",
                .procname       = "nf_conntrack_dccp_loose",
                .maxlen         = sizeof(int),
                .mode           = 0644,
-               .proc_handler   = proc_dointvec,
+               .proc_handler   = proc_dointvec_minmax,
+               .extra1         = &zero,
+               .extra2         = &one,
        },
 #endif
 #ifdef CONFIG_NF_CT_PROTO_GRE