root/net/ipv4/sysctl_net_ipv4.c
// SPDX-License-Identifier: GPL-2.0
/*
 * sysctl_net_ipv4.c: sysctl interface to net IPV4 subsystem.
 *
 * Begun April 1, 1996, Mike Shaver.
 * Added /proc/sys/net/ipv4 directory entry (empty =) ). [MS]
 */

#include <linux/sysctl.h>
#include <linux/seqlock.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <net/icmp.h>
#include <net/ip.h>
#include <net/ip_fib.h>
#include <net/tcp.h>
#include <net/udp.h>
#include <net/cipso_ipv4.h>
#include <net/ping.h>
#include <net/protocol.h>
#include <net/netevent.h>

static int tcp_retr1_max = 255;
static int ip_local_port_range_min[] = { 1, 1 };
static int ip_local_port_range_max[] = { 65535, 65535 };
static int tcp_adv_win_scale_min = -31;
static int tcp_adv_win_scale_max = 31;
static int tcp_app_win_max = 31;
static int tcp_min_snd_mss_min = TCP_MIN_SND_MSS;
static int tcp_min_snd_mss_max = 65535;
static int tcp_rto_max_max = TCP_RTO_MAX_SEC * MSEC_PER_SEC;
static int ip_privileged_port_min;
static int ip_privileged_port_max = 65535;
static int ip_ttl_min = 1;
static int ip_ttl_max = 255;
static int tcp_syn_retries_min = 1;
static int tcp_syn_retries_max = MAX_TCP_SYNCNT;
static int tcp_syn_linear_timeouts_max = MAX_TCP_SYNCNT;
static unsigned long ip_ping_group_range_min[] = { 0, 0 };
static unsigned long ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX };
static u32 u32_max_div_HZ = UINT_MAX / HZ;
static int one_day_secs = 24 * 3600;
static u32 fib_multipath_hash_fields_all_mask __maybe_unused =
        FIB_MULTIPATH_HASH_FIELD_ALL_MASK;
static unsigned int tcp_child_ehash_entries_max = 16 * 1024 * 1024;
static unsigned int udp_child_hash_entries_max = UDP_HTABLE_SIZE_MAX;
static int tcp_plb_max_rounds = 31;
static int tcp_plb_max_cong_thresh = 256;
static unsigned int tcp_tw_reuse_delay_max = TCP_PAWS_MSL * MSEC_PER_SEC;
static int tcp_ecn_mode_max = 5;
static u32 icmp_errors_extension_mask_all =
        GENMASK_U8(ICMP_ERR_EXT_COUNT - 1, 0);

/* obsolete */
static int sysctl_tcp_low_latency __read_mostly;

/* Update system visible IP port range */
static void set_local_port_range(struct net *net, unsigned int low, unsigned int high)
{
        bool same_parity = !((low ^ high) & 1);

        if (same_parity && !net->ipv4.ip_local_ports.warned) {
                net->ipv4.ip_local_ports.warned = true;
                pr_err_ratelimited("ip_local_port_range: prefer different parity for start/end values.\n");
        }
        WRITE_ONCE(net->ipv4.ip_local_ports.range, high << 16 | low);
}

/* Validate changes from /proc interface. */
static int ipv4_local_port_range(const struct ctl_table *table, int write,
                                 void *buffer, size_t *lenp, loff_t *ppos)
{
        struct net *net = table->data;
        int ret;
        int range[2];
        struct ctl_table tmp = {
                .data = &range,
                .maxlen = sizeof(range),
                .mode = table->mode,
                .extra1 = &ip_local_port_range_min,
                .extra2 = &ip_local_port_range_max,
        };

        inet_get_local_port_range(net, &range[0], &range[1]);

        ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);

        if (write && ret == 0) {
                /* Ensure that the upper limit is not smaller than the lower,
                 * and that the lower does not encroach upon the privileged
                 * port limit.
                 */
                if ((range[1] < range[0]) ||
                    (range[0] < READ_ONCE(net->ipv4.sysctl_ip_prot_sock)))
                        ret = -EINVAL;
                else
                        set_local_port_range(net, range[0], range[1]);
        }

        return ret;
}

/* Validate changes from /proc interface. */
static int ipv4_privileged_ports(const struct ctl_table *table, int write,
                                void *buffer, size_t *lenp, loff_t *ppos)
{
        struct net *net = container_of(table->data, struct net,
            ipv4.sysctl_ip_prot_sock);
        int ret;
        int pports;
        int range[2];
        struct ctl_table tmp = {
                .data = &pports,
                .maxlen = sizeof(pports),
                .mode = table->mode,
                .extra1 = &ip_privileged_port_min,
                .extra2 = &ip_privileged_port_max,
        };

        pports = READ_ONCE(net->ipv4.sysctl_ip_prot_sock);

        ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);

        if (write && ret == 0) {
                inet_get_local_port_range(net, &range[0], &range[1]);
                /* Ensure that the local port range doesn't overlap with the
                 * privileged port range.
                 */
                if (range[0] < pports)
                        ret = -EINVAL;
                else
                        WRITE_ONCE(net->ipv4.sysctl_ip_prot_sock, pports);
        }

        return ret;
}

static void inet_get_ping_group_range_table(const struct ctl_table *table,
                                            kgid_t *low, kgid_t *high)
{
        kgid_t *data = table->data;
        struct net *net =
                container_of(table->data, struct net, ipv4.ping_group_range.range);
        unsigned int seq;
        do {
                seq = read_seqbegin(&net->ipv4.ping_group_range.lock);

                *low = data[0];
                *high = data[1];
        } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
}

/* Update system visible IP port range */
static void set_ping_group_range(const struct ctl_table *table,
                                 kgid_t low, kgid_t high)
{
        kgid_t *data = table->data;
        struct net *net =
                container_of(table->data, struct net, ipv4.ping_group_range.range);
        write_seqlock(&net->ipv4.ping_group_range.lock);
        data[0] = low;
        data[1] = high;
        write_sequnlock(&net->ipv4.ping_group_range.lock);
}

/* Validate changes from /proc interface. */
static int ipv4_ping_group_range(const struct ctl_table *table, int write,
                                 void *buffer, size_t *lenp, loff_t *ppos)
{
        struct user_namespace *user_ns = current_user_ns();
        int ret;
        unsigned long urange[2];
        kgid_t low, high;
        struct ctl_table tmp = {
                .data = &urange,
                .maxlen = sizeof(urange),
                .mode = table->mode,
                .extra1 = &ip_ping_group_range_min,
                .extra2 = &ip_ping_group_range_max,
        };

        inet_get_ping_group_range_table(table, &low, &high);
        urange[0] = from_kgid_munged(user_ns, low);
        urange[1] = from_kgid_munged(user_ns, high);
        ret = proc_doulongvec_minmax(&tmp, write, buffer, lenp, ppos);

        if (write && ret == 0) {
                low = make_kgid(user_ns, urange[0]);
                high = make_kgid(user_ns, urange[1]);
                if (!gid_valid(low) || !gid_valid(high))
                        return -EINVAL;
                if (urange[1] < urange[0] || gid_lt(high, low)) {
                        low = make_kgid(&init_user_ns, 1);
                        high = make_kgid(&init_user_ns, 0);
                }
                set_ping_group_range(table, low, high);
        }

        return ret;
}

static int ipv4_fwd_update_priority(const struct ctl_table *table, int write,
                                    void *buffer, size_t *lenp, loff_t *ppos)
{
        struct net *net;
        int ret;

        net = container_of(table->data, struct net,
                           ipv4.sysctl_ip_fwd_update_priority);
        ret = proc_dou8vec_minmax(table, write, buffer, lenp, ppos);
        if (write && ret == 0)
                call_netevent_notifiers(NETEVENT_IPV4_FWD_UPDATE_PRIORITY_UPDATE,
                                        net);

        return ret;
}

static int proc_tcp_congestion_control(const struct ctl_table *ctl, int write,
                                       void *buffer, size_t *lenp, loff_t *ppos)
{
        struct net *net = container_of(ctl->data, struct net,
                                       ipv4.tcp_congestion_control);
        char val[TCP_CA_NAME_MAX];
        struct ctl_table tbl = {
                .data = val,
                .maxlen = TCP_CA_NAME_MAX,
        };
        int ret;

        tcp_get_default_congestion_control(net, val);

        ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
        if (write && ret == 0)
                ret = tcp_set_default_congestion_control(net, val);
        return ret;
}

static int proc_tcp_available_congestion_control(const struct ctl_table *ctl,
                                                 int write, void *buffer,
                                                 size_t *lenp, loff_t *ppos)
{
        struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX, };
        int ret;

        tbl.data = kmalloc(tbl.maxlen, GFP_USER);
        if (!tbl.data)
                return -ENOMEM;
        tcp_get_available_congestion_control(tbl.data, TCP_CA_BUF_MAX);
        ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
        kfree(tbl.data);
        return ret;
}

static int proc_allowed_congestion_control(const struct ctl_table *ctl,
                                           int write, void *buffer,
                                           size_t *lenp, loff_t *ppos)
{
        struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX };
        int ret;

        tbl.data = kmalloc(tbl.maxlen, GFP_USER);
        if (!tbl.data)
                return -ENOMEM;

        tcp_get_allowed_congestion_control(tbl.data, tbl.maxlen);
        ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
        if (write && ret == 0)
                ret = tcp_set_allowed_congestion_control(tbl.data);
        kfree(tbl.data);
        return ret;
}

static int sscanf_key(char *buf, __le32 *key)
{
        u32 user_key[4];
        int i, ret = 0;

        if (sscanf(buf, "%x-%x-%x-%x", user_key, user_key + 1,
                   user_key + 2, user_key + 3) != 4) {
                ret = -EINVAL;
        } else {
                for (i = 0; i < ARRAY_SIZE(user_key); i++)
                        key[i] = cpu_to_le32(user_key[i]);
        }
        pr_debug("proc TFO key set 0x%x-%x-%x-%x <- 0x%s: %u\n",
                 user_key[0], user_key[1], user_key[2], user_key[3], buf, ret);

        return ret;
}

static int proc_tcp_fastopen_key(const struct ctl_table *table, int write,
                                 void *buffer, size_t *lenp, loff_t *ppos)
{
        struct net *net = container_of(table->data, struct net,
            ipv4.sysctl_tcp_fastopen);
        /* maxlen to print the list of keys in hex (*2), with dashes
         * separating doublewords and a comma in between keys.
         */
        struct ctl_table tbl = { .maxlen = ((TCP_FASTOPEN_KEY_LENGTH *
                                            2 * TCP_FASTOPEN_KEY_MAX) +
                                            (TCP_FASTOPEN_KEY_MAX * 5)) };
        u32 user_key[TCP_FASTOPEN_KEY_BUF_LENGTH / sizeof(u32)];
        __le32 key[TCP_FASTOPEN_KEY_BUF_LENGTH / sizeof(__le32)];
        char *backup_data;
        int ret, i = 0, off = 0, n_keys;

        tbl.data = kmalloc(tbl.maxlen, GFP_KERNEL);
        if (!tbl.data)
                return -ENOMEM;

        n_keys = tcp_fastopen_get_cipher(net, NULL, (u64 *)key);
        if (!n_keys) {
                memset(&key[0], 0, TCP_FASTOPEN_KEY_LENGTH);
                n_keys = 1;
        }

        for (i = 0; i < n_keys * 4; i++)
                user_key[i] = le32_to_cpu(key[i]);

        for (i = 0; i < n_keys; i++) {
                off += snprintf(tbl.data + off, tbl.maxlen - off,
                                "%08x-%08x-%08x-%08x",
                                user_key[i * 4],
                                user_key[i * 4 + 1],
                                user_key[i * 4 + 2],
                                user_key[i * 4 + 3]);

                if (WARN_ON_ONCE(off >= tbl.maxlen - 1))
                        break;

                if (i + 1 < n_keys)
                        off += snprintf(tbl.data + off, tbl.maxlen - off, ",");
        }

        ret = proc_dostring(&tbl, write, buffer, lenp, ppos);

        if (write && ret == 0) {
                backup_data = strchr(tbl.data, ',');
                if (backup_data) {
                        *backup_data = '\0';
                        backup_data++;
                }
                if (sscanf_key(tbl.data, key)) {
                        ret = -EINVAL;
                        goto bad_key;
                }
                if (backup_data) {
                        if (sscanf_key(backup_data, key + 4)) {
                                ret = -EINVAL;
                                goto bad_key;
                        }
                }
                tcp_fastopen_reset_cipher(net, NULL, key,
                                          backup_data ? key + 4 : NULL);
        }

bad_key:
        kfree(tbl.data);
        return ret;
}

static int proc_tfo_blackhole_detect_timeout(const struct ctl_table *table,
                                             int write, void *buffer,
                                             size_t *lenp, loff_t *ppos)
{
        struct net *net = container_of(table->data, struct net,
            ipv4.sysctl_tcp_fastopen_blackhole_timeout);
        int ret;

        ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
        if (write && ret == 0)
                atomic_set(&net->ipv4.tfo_active_disable_times, 0);

        return ret;
}

static int proc_tcp_available_ulp(const struct ctl_table *ctl,
                                  int write, void *buffer, size_t *lenp,
                                  loff_t *ppos)
{
        struct ctl_table tbl = { .maxlen = TCP_ULP_BUF_MAX, };
        int ret;

        tbl.data = kmalloc(tbl.maxlen, GFP_USER);
        if (!tbl.data)
                return -ENOMEM;
        tcp_get_available_ulp(tbl.data, TCP_ULP_BUF_MAX);
        ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
        kfree(tbl.data);

        return ret;
}

static int proc_tcp_ehash_entries(const struct ctl_table *table, int write,
                                  void *buffer, size_t *lenp, loff_t *ppos)
{
        struct net *net = container_of(table->data, struct net,
                                       ipv4.sysctl_tcp_child_ehash_entries);
        struct inet_hashinfo *hinfo = net->ipv4.tcp_death_row.hashinfo;
        int tcp_ehash_entries;
        struct ctl_table tbl;

        tcp_ehash_entries = hinfo->ehash_mask + 1;

        /* A negative number indicates that the child netns
         * shares the global ehash.
         */
        if (!net_eq(net, &init_net) && !hinfo->pernet)
                tcp_ehash_entries *= -1;

        memset(&tbl, 0, sizeof(tbl));
        tbl.data = &tcp_ehash_entries;
        tbl.maxlen = sizeof(int);

        return proc_dointvec(&tbl, write, buffer, lenp, ppos);
}

static int proc_udp_hash_entries(const struct ctl_table *table, int write,
                                 void *buffer, size_t *lenp, loff_t *ppos)
{
        struct net *net = container_of(table->data, struct net,
                                       ipv4.sysctl_udp_child_hash_entries);
        int udp_hash_entries;
        struct ctl_table tbl;

        udp_hash_entries = net->ipv4.udp_table->mask + 1;

        /* A negative number indicates that the child netns
         * shares the global udp_table.
         */
        if (!net_eq(net, &init_net) && net->ipv4.udp_table == &udp_table)
                udp_hash_entries *= -1;

        memset(&tbl, 0, sizeof(tbl));
        tbl.data = &udp_hash_entries;
        tbl.maxlen = sizeof(int);

        return proc_dointvec(&tbl, write, buffer, lenp, ppos);
}

#ifdef CONFIG_IP_ROUTE_MULTIPATH
static int proc_fib_multipath_hash_policy(const struct ctl_table *table, int write,
                                          void *buffer, size_t *lenp,
                                          loff_t *ppos)
{
        struct net *net = container_of(table->data, struct net,
            ipv4.sysctl_fib_multipath_hash_policy);
        int ret;

        ret = proc_dou8vec_minmax(table, write, buffer, lenp, ppos);
        if (write && ret == 0)
                call_netevent_notifiers(NETEVENT_IPV4_MPATH_HASH_UPDATE, net);

        return ret;
}

static int proc_fib_multipath_hash_fields(const struct ctl_table *table, int write,
                                          void *buffer, size_t *lenp,
                                          loff_t *ppos)
{
        struct net *net;
        int ret;

        net = container_of(table->data, struct net,
                           ipv4.sysctl_fib_multipath_hash_fields);
        ret = proc_douintvec_minmax(table, write, buffer, lenp, ppos);
        if (write && ret == 0)
                call_netevent_notifiers(NETEVENT_IPV4_MPATH_HASH_UPDATE, net);

        return ret;
}

static u32 proc_fib_multipath_hash_rand_seed __ro_after_init;

static void proc_fib_multipath_hash_init_rand_seed(void)
{
        get_random_bytes(&proc_fib_multipath_hash_rand_seed,
                         sizeof(proc_fib_multipath_hash_rand_seed));
}

static void proc_fib_multipath_hash_set_seed(struct net *net, u32 user_seed)
{
        struct sysctl_fib_multipath_hash_seed new = {
                .user_seed = user_seed,
                .mp_seed = (user_seed ? user_seed :
                            proc_fib_multipath_hash_rand_seed),
        };

        WRITE_ONCE(net->ipv4.sysctl_fib_multipath_hash_seed.user_seed, new.user_seed);
        WRITE_ONCE(net->ipv4.sysctl_fib_multipath_hash_seed.mp_seed, new.mp_seed);
}

static int proc_fib_multipath_hash_seed(const struct ctl_table *table, int write,
                                        void *buffer, size_t *lenp,
                                        loff_t *ppos)
{
        struct sysctl_fib_multipath_hash_seed *mphs;
        struct net *net = table->data;
        struct ctl_table tmp;
        u32 user_seed;
        int ret;

        mphs = &net->ipv4.sysctl_fib_multipath_hash_seed;
        user_seed = READ_ONCE(mphs->user_seed);

        tmp = *table;
        tmp.data = &user_seed;

        ret = proc_douintvec_minmax(&tmp, write, buffer, lenp, ppos);

        if (write && ret == 0) {
                proc_fib_multipath_hash_set_seed(net, user_seed);
                call_netevent_notifiers(NETEVENT_IPV4_MPATH_HASH_UPDATE, net);
        }

        return ret;
}
#else

static void proc_fib_multipath_hash_init_rand_seed(void)
{
}

static void proc_fib_multipath_hash_set_seed(struct net *net, u32 user_seed)
{
}

#endif

static struct ctl_table ipv4_table[] = {
        {
                .procname       = "tcp_max_orphans",
                .data           = &sysctl_tcp_max_orphans,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
        {
                .procname       = "inet_peer_threshold",
                .data           = &inet_peer_threshold,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
        {
                .procname       = "inet_peer_minttl",
                .data           = &inet_peer_minttl,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_jiffies,
        },
        {
                .procname       = "inet_peer_maxttl",
                .data           = &inet_peer_maxttl,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_jiffies,
        },
        {
                .procname       = "tcp_mem",
                .maxlen         = sizeof(sysctl_tcp_mem),
                .data           = &sysctl_tcp_mem,
                .mode           = 0644,
                .proc_handler   = proc_doulongvec_minmax,
        },
        {
                .procname       = "tcp_low_latency",
                .data           = &sysctl_tcp_low_latency,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
#ifdef CONFIG_NETLABEL
        {
                .procname       = "cipso_cache_enable",
                .data           = &cipso_v4_cache_enabled,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "cipso_cache_bucket_size",
                .data           = &cipso_v4_cache_bucketsize,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "cipso_rbm_optfmt",
                .data           = &cipso_v4_rbm_optfmt,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "cipso_rbm_strictvalid",
                .data           = &cipso_v4_rbm_strictvalid,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
#endif /* CONFIG_NETLABEL */
        {
                .procname       = "tcp_available_ulp",
                .maxlen         = TCP_ULP_BUF_MAX,
                .mode           = 0444,
                .proc_handler   = proc_tcp_available_ulp,
        },
        {
                .procname       = "udp_mem",
                .data           = &sysctl_udp_mem,
                .maxlen         = sizeof(sysctl_udp_mem),
                .mode           = 0644,
                .proc_handler   = proc_doulongvec_minmax,
        },
        {
                .procname       = "fib_sync_mem",
                .data           = &sysctl_fib_sync_mem,
                .maxlen         = sizeof(sysctl_fib_sync_mem),
                .mode           = 0644,
                .proc_handler   = proc_douintvec_minmax,
                .extra1         = &sysctl_fib_sync_mem_min,
                .extra2         = &sysctl_fib_sync_mem_max,
        },
};

static struct ctl_table ipv4_net_table[] = {
        {
                .procname       = "tcp_max_tw_buckets",
                .data           = &init_net.ipv4.tcp_death_row.sysctl_max_tw_buckets,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
        {
                .procname       = "icmp_echo_ignore_all",
                .data           = &init_net.ipv4.sysctl_icmp_echo_ignore_all,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE
        },
        {
                .procname       = "icmp_echo_enable_probe",
                .data           = &init_net.ipv4.sysctl_icmp_echo_enable_probe,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE
        },
        {
                .procname       = "icmp_echo_ignore_broadcasts",
                .data           = &init_net.ipv4.sysctl_icmp_echo_ignore_broadcasts,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE
        },
        {
                .procname       = "icmp_ignore_bogus_error_responses",
                .data           = &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE
        },
        {
                .procname       = "icmp_errors_use_inbound_ifaddr",
                .data           = &init_net.ipv4.sysctl_icmp_errors_use_inbound_ifaddr,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE
        },
        {
                .procname       = "icmp_errors_extension_mask",
                .data           = &init_net.ipv4.sysctl_icmp_errors_extension_mask,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = &icmp_errors_extension_mask_all,
        },
        {
                .procname       = "icmp_ratelimit",
                .data           = &init_net.ipv4.sysctl_icmp_ratelimit,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_ms_jiffies,
        },
        {
                .procname       = "icmp_ratemask",
                .data           = &init_net.ipv4.sysctl_icmp_ratemask,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
        {
                .procname       = "icmp_msgs_per_sec",
                .data           = &init_net.ipv4.sysctl_icmp_msgs_per_sec,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
        },
        {
                .procname       = "icmp_msgs_burst",
                .data           = &init_net.ipv4.sysctl_icmp_msgs_burst,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
        },
        {
                .procname       = "ping_group_range",
                .data           = &init_net.ipv4.ping_group_range.range,
                .maxlen         = sizeof(gid_t)*2,
                .mode           = 0644,
                .proc_handler   = ipv4_ping_group_range,
        },
#ifdef CONFIG_NET_L3_MASTER_DEV
        {
                .procname       = "raw_l3mdev_accept",
                .data           = &init_net.ipv4.sysctl_raw_l3mdev_accept,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE,
        },
#endif
        {
                .procname       = "tcp_ecn",
                .data           = &init_net.ipv4.sysctl_tcp_ecn,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = &tcp_ecn_mode_max,
        },
        {
                .procname       = "tcp_ecn_option",
                .data           = &init_net.ipv4.sysctl_tcp_ecn_option,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_THREE,
        },
        {
                .procname       = "tcp_ecn_option_beacon",
                .data           = &init_net.ipv4.sysctl_tcp_ecn_option_beacon,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_THREE,
        },
        {
                .procname       = "tcp_ecn_fallback",
                .data           = &init_net.ipv4.sysctl_tcp_ecn_fallback,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE,
        },
        {
                .procname       = "ip_dynaddr",
                .data           = &init_net.ipv4.sysctl_ip_dynaddr,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "ip_early_demux",
                .data           = &init_net.ipv4.sysctl_ip_early_demux,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "udp_early_demux",
                .data           = &init_net.ipv4.sysctl_udp_early_demux,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_early_demux",
                .data           = &init_net.ipv4.sysctl_tcp_early_demux,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "nexthop_compat_mode",
                .data           = &init_net.ipv4.sysctl_nexthop_compat_mode,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE,
        },
        {
                .procname       = "ip_default_ttl",
                .data           = &init_net.ipv4.sysctl_ip_default_ttl,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = &ip_ttl_min,
                .extra2         = &ip_ttl_max,
        },
        {
                .procname       = "ip_local_port_range",
                .maxlen         = 0,
                .data           = &init_net,
                .mode           = 0644,
                .proc_handler   = ipv4_local_port_range,
        },
        {
                .procname       = "ip_local_reserved_ports",
                .data           = &init_net.ipv4.sysctl_local_reserved_ports,
                .maxlen         = 65536,
                .mode           = 0644,
                .proc_handler   = proc_do_large_bitmap,
        },
        {
                .procname       = "ip_no_pmtu_disc",
                .data           = &init_net.ipv4.sysctl_ip_no_pmtu_disc,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "ip_forward_use_pmtu",
                .data           = &init_net.ipv4.sysctl_ip_fwd_use_pmtu,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "ip_forward_update_priority",
                .data           = &init_net.ipv4.sysctl_ip_fwd_update_priority,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = ipv4_fwd_update_priority,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE,
        },
        {
                .procname       = "ip_nonlocal_bind",
                .data           = &init_net.ipv4.sysctl_ip_nonlocal_bind,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "ip_autobind_reuse",
                .data           = &init_net.ipv4.sysctl_ip_autobind_reuse,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE,
        },
        {
                .procname       = "fwmark_reflect",
                .data           = &init_net.ipv4.sysctl_fwmark_reflect,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_fwmark_accept",
                .data           = &init_net.ipv4.sysctl_tcp_fwmark_accept,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
#ifdef CONFIG_NET_L3_MASTER_DEV
        {
                .procname       = "tcp_l3mdev_accept",
                .data           = &init_net.ipv4.sysctl_tcp_l3mdev_accept,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE,
        },
#endif
        {
                .procname       = "tcp_mtu_probing",
                .data           = &init_net.ipv4.sysctl_tcp_mtu_probing,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_base_mss",
                .data           = &init_net.ipv4.sysctl_tcp_base_mss,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "tcp_min_snd_mss",
                .data           = &init_net.ipv4.sysctl_tcp_min_snd_mss,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = &tcp_min_snd_mss_min,
                .extra2         = &tcp_min_snd_mss_max,
        },
        {
                .procname       = "tcp_mtu_probe_floor",
                .data           = &init_net.ipv4.sysctl_tcp_mtu_probe_floor,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = &tcp_min_snd_mss_min,
                .extra2         = &tcp_min_snd_mss_max,
        },
        {
                .procname       = "tcp_probe_threshold",
                .data           = &init_net.ipv4.sysctl_tcp_probe_threshold,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "tcp_probe_interval",
                .data           = &init_net.ipv4.sysctl_tcp_probe_interval,
                .maxlen         = sizeof(u32),
                .mode           = 0644,
                .proc_handler   = proc_douintvec_minmax,
                .extra2         = &u32_max_div_HZ,
        },
        {
                .procname       = "igmp_link_local_mcast_reports",
                .data           = &init_net.ipv4.sysctl_igmp_llm_reports,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "igmp_max_memberships",
                .data           = &init_net.ipv4.sysctl_igmp_max_memberships,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
        {
                .procname       = "igmp_max_msf",
                .data           = &init_net.ipv4.sysctl_igmp_max_msf,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
#ifdef CONFIG_IP_MULTICAST
        {
                .procname       = "igmp_qrv",
                .data           = &init_net.ipv4.sysctl_igmp_qrv,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ONE
        },
#endif
        {
                .procname       = "tcp_congestion_control",
                .data           = &init_net.ipv4.tcp_congestion_control,
                .mode           = 0644,
                .maxlen         = TCP_CA_NAME_MAX,
                .proc_handler   = proc_tcp_congestion_control,
        },
        {
                .procname       = "tcp_available_congestion_control",
                .maxlen         = TCP_CA_BUF_MAX,
                .mode           = 0444,
                .proc_handler   = proc_tcp_available_congestion_control,
        },
        {
                .procname       = "tcp_allowed_congestion_control",
                .maxlen         = TCP_CA_BUF_MAX,
                .mode           = 0644,
                .proc_handler   = proc_allowed_congestion_control,
        },
        {
                .procname       = "tcp_keepalive_time",
                .data           = &init_net.ipv4.sysctl_tcp_keepalive_time,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_jiffies,
        },
        {
                .procname       = "tcp_keepalive_probes",
                .data           = &init_net.ipv4.sysctl_tcp_keepalive_probes,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_keepalive_intvl",
                .data           = &init_net.ipv4.sysctl_tcp_keepalive_intvl,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_jiffies,
        },
        {
                .procname       = "tcp_syn_retries",
                .data           = &init_net.ipv4.sysctl_tcp_syn_retries,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = &tcp_syn_retries_min,
                .extra2         = &tcp_syn_retries_max
        },
        {
                .procname       = "tcp_synack_retries",
                .data           = &init_net.ipv4.sysctl_tcp_synack_retries,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
#ifdef CONFIG_SYN_COOKIES
        {
                .procname       = "tcp_syncookies",
                .data           = &init_net.ipv4.sysctl_tcp_syncookies,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
#endif
        {
                .procname       = "tcp_migrate_req",
                .data           = &init_net.ipv4.sysctl_tcp_migrate_req,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE
        },
        {
                .procname       = "tcp_reordering",
                .data           = &init_net.ipv4.sysctl_tcp_reordering,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
        {
                .procname       = "tcp_retries1",
                .data           = &init_net.ipv4.sysctl_tcp_retries1,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra2         = &tcp_retr1_max
        },
        {
                .procname       = "tcp_retries2",
                .data           = &init_net.ipv4.sysctl_tcp_retries2,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_orphan_retries",
                .data           = &init_net.ipv4.sysctl_tcp_orphan_retries,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_fin_timeout",
                .data           = &init_net.ipv4.sysctl_tcp_fin_timeout,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_jiffies,
        },
        {
                .procname       = "tcp_notsent_lowat",
                .data           = &init_net.ipv4.sysctl_tcp_notsent_lowat,
                .maxlen         = sizeof(unsigned int),
                .mode           = 0644,
                .proc_handler   = proc_douintvec,
        },
        {
                .procname       = "tcp_tw_reuse",
                .data           = &init_net.ipv4.sysctl_tcp_tw_reuse,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_TWO,
        },
        {
                .procname       = "tcp_tw_reuse_delay",
                .data           = &init_net.ipv4.sysctl_tcp_tw_reuse_delay,
                .maxlen         = sizeof(unsigned int),
                .mode           = 0644,
                .proc_handler   = proc_douintvec_minmax,
                .extra1         = SYSCTL_ONE,
                .extra2         = &tcp_tw_reuse_delay_max,
        },
        {
                .procname       = "tcp_max_syn_backlog",
                .data           = &init_net.ipv4.sysctl_max_syn_backlog,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
        {
                .procname       = "tcp_fastopen",
                .data           = &init_net.ipv4.sysctl_tcp_fastopen,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "tcp_fastopen_key",
                .mode           = 0600,
                .data           = &init_net.ipv4.sysctl_tcp_fastopen,
                /* maxlen to print the list of keys in hex (*2), with dashes
                 * separating doublewords and a comma in between keys.
                 */
                .maxlen         = ((TCP_FASTOPEN_KEY_LENGTH *
                                   2 * TCP_FASTOPEN_KEY_MAX) +
                                   (TCP_FASTOPEN_KEY_MAX * 5)),
                .proc_handler   = proc_tcp_fastopen_key,
        },
        {
                .procname       = "tcp_fastopen_blackhole_timeout_sec",
                .data           = &init_net.ipv4.sysctl_tcp_fastopen_blackhole_timeout,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_tfo_blackhole_detect_timeout,
                .extra1         = SYSCTL_ZERO,
        },
#ifdef CONFIG_IP_ROUTE_MULTIPATH
        {
                .procname       = "fib_multipath_use_neigh",
                .data           = &init_net.ipv4.sysctl_fib_multipath_use_neigh,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE,
        },
        {
                .procname       = "fib_multipath_hash_policy",
                .data           = &init_net.ipv4.sysctl_fib_multipath_hash_policy,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_fib_multipath_hash_policy,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_THREE,
        },
        {
                .procname       = "fib_multipath_hash_fields",
                .data           = &init_net.ipv4.sysctl_fib_multipath_hash_fields,
                .maxlen         = sizeof(u32),
                .mode           = 0644,
                .proc_handler   = proc_fib_multipath_hash_fields,
                .extra1         = SYSCTL_ONE,
                .extra2         = &fib_multipath_hash_fields_all_mask,
        },
        {
                .procname       = "fib_multipath_hash_seed",
                .data           = &init_net,
                .maxlen         = sizeof(u32),
                .mode           = 0644,
                .proc_handler   = proc_fib_multipath_hash_seed,
        },
#endif
        {
                .procname       = "ip_unprivileged_port_start",
                .maxlen         = sizeof(int),
                .data           = &init_net.ipv4.sysctl_ip_prot_sock,
                .mode           = 0644,
                .proc_handler   = ipv4_privileged_ports,
        },
#ifdef CONFIG_NET_L3_MASTER_DEV
        {
                .procname       = "udp_l3mdev_accept",
                .data           = &init_net.ipv4.sysctl_udp_l3mdev_accept,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE,
        },
#endif
        {
                .procname       = "tcp_sack",
                .data           = &init_net.ipv4.sysctl_tcp_sack,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_window_scaling",
                .data           = &init_net.ipv4.sysctl_tcp_window_scaling,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_timestamps",
                .data           = &init_net.ipv4.sysctl_tcp_timestamps,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_early_retrans",
                .data           = &init_net.ipv4.sysctl_tcp_early_retrans,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_FOUR,
        },
        {
                .procname       = "tcp_recovery",
                .data           = &init_net.ipv4.sysctl_tcp_recovery,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_thin_linear_timeouts",
                .data           = &init_net.ipv4.sysctl_tcp_thin_linear_timeouts,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_slow_start_after_idle",
                .data           = &init_net.ipv4.sysctl_tcp_slow_start_after_idle,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_retrans_collapse",
                .data           = &init_net.ipv4.sysctl_tcp_retrans_collapse,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_stdurg",
                .data           = &init_net.ipv4.sysctl_tcp_stdurg,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_rfc1337",
                .data           = &init_net.ipv4.sysctl_tcp_rfc1337,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_abort_on_overflow",
                .data           = &init_net.ipv4.sysctl_tcp_abort_on_overflow,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_fack",
                .data           = &init_net.ipv4.sysctl_tcp_fack,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_max_reordering",
                .data           = &init_net.ipv4.sysctl_tcp_max_reordering,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
        {
                .procname       = "tcp_dsack",
                .data           = &init_net.ipv4.sysctl_tcp_dsack,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_app_win",
                .data           = &init_net.ipv4.sysctl_tcp_app_win,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = &tcp_app_win_max,
        },
        {
                .procname       = "tcp_adv_win_scale",
                .data           = &init_net.ipv4.sysctl_tcp_adv_win_scale,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = &tcp_adv_win_scale_min,
                .extra2         = &tcp_adv_win_scale_max,
        },
        {
                .procname       = "tcp_frto",
                .data           = &init_net.ipv4.sysctl_tcp_frto,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_no_metrics_save",
                .data           = &init_net.ipv4.sysctl_tcp_nometrics_save,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_no_ssthresh_metrics_save",
                .data           = &init_net.ipv4.sysctl_tcp_no_ssthresh_metrics_save,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE,
        },
        {
                .procname       = "tcp_moderate_rcvbuf",
                .data           = &init_net.ipv4.sysctl_tcp_moderate_rcvbuf,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_rcvbuf_low_rtt",
                .data           = &init_net.ipv4.sysctl_tcp_rcvbuf_low_rtt,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_INT_MAX,
        },
        {
                .procname       = "tcp_tso_win_divisor",
                .data           = &init_net.ipv4.sysctl_tcp_tso_win_divisor,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_workaround_signed_windows",
                .data           = &init_net.ipv4.sysctl_tcp_workaround_signed_windows,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_limit_output_bytes",
                .data           = &init_net.ipv4.sysctl_tcp_limit_output_bytes,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
        {
                .procname       = "tcp_challenge_ack_limit",
                .data           = &init_net.ipv4.sysctl_tcp_challenge_ack_limit,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
        {
                .procname       = "tcp_min_tso_segs",
                .data           = &init_net.ipv4.sysctl_tcp_min_tso_segs,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ONE,
        },
        {
                .procname       = "tcp_tso_rtt_log",
                .data           = &init_net.ipv4.sysctl_tcp_tso_rtt_log,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_min_rtt_wlen",
                .data           = &init_net.ipv4.sysctl_tcp_min_rtt_wlen,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = &one_day_secs
        },
        {
                .procname       = "tcp_autocorking",
                .data           = &init_net.ipv4.sysctl_tcp_autocorking,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE,
        },
        {
                .procname       = "tcp_invalid_ratelimit",
                .data           = &init_net.ipv4.sysctl_tcp_invalid_ratelimit,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_ms_jiffies,
        },
        {
                .procname       = "tcp_pacing_ss_ratio",
                .data           = &init_net.ipv4.sysctl_tcp_pacing_ss_ratio,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE_THOUSAND,
        },
        {
                .procname       = "tcp_pacing_ca_ratio",
                .data           = &init_net.ipv4.sysctl_tcp_pacing_ca_ratio,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE_THOUSAND,
        },
        {
                .procname       = "tcp_wmem",
                .data           = &init_net.ipv4.sysctl_tcp_wmem,
                .maxlen         = sizeof(init_net.ipv4.sysctl_tcp_wmem),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ONE,
        },
        {
                .procname       = "tcp_rmem",
                .data           = &init_net.ipv4.sysctl_tcp_rmem,
                .maxlen         = sizeof(init_net.ipv4.sysctl_tcp_rmem),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ONE,
        },
        {
                .procname       = "tcp_comp_sack_delay_ns",
                .data           = &init_net.ipv4.sysctl_tcp_comp_sack_delay_ns,
                .maxlen         = sizeof(unsigned long),
                .mode           = 0644,
                .proc_handler   = proc_doulongvec_minmax,
        },
        {
                .procname       = "tcp_comp_sack_rtt_percent",
                .data           = &init_net.ipv4.sysctl_tcp_comp_sack_rtt_percent,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ONE,
                .extra2         = SYSCTL_ONE_THOUSAND,
        },
        {
                .procname       = "tcp_comp_sack_slack_ns",
                .data           = &init_net.ipv4.sysctl_tcp_comp_sack_slack_ns,
                .maxlen         = sizeof(unsigned long),
                .mode           = 0644,
                .proc_handler   = proc_doulongvec_minmax,
        },
        {
                .procname       = "tcp_comp_sack_nr",
                .data           = &init_net.ipv4.sysctl_tcp_comp_sack_nr,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
        },
        {
                .procname       = "tcp_backlog_ack_defer",
                .data           = &init_net.ipv4.sysctl_tcp_backlog_ack_defer,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE,
        },
        {
                .procname       = "tcp_reflect_tos",
                .data           = &init_net.ipv4.sysctl_tcp_reflect_tos,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE,
        },
        {
                .procname       = "tcp_ehash_entries",
                .data           = &init_net.ipv4.sysctl_tcp_child_ehash_entries,
                .mode           = 0444,
                .proc_handler   = proc_tcp_ehash_entries,
        },
        {
                .procname       = "tcp_child_ehash_entries",
                .data           = &init_net.ipv4.sysctl_tcp_child_ehash_entries,
                .maxlen         = sizeof(unsigned int),
                .mode           = 0644,
                .proc_handler   = proc_douintvec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = &tcp_child_ehash_entries_max,
        },
        {
                .procname       = "udp_hash_entries",
                .data           = &init_net.ipv4.sysctl_udp_child_hash_entries,
                .mode           = 0444,
                .proc_handler   = proc_udp_hash_entries,
        },
        {
                .procname       = "udp_child_hash_entries",
                .data           = &init_net.ipv4.sysctl_udp_child_hash_entries,
                .maxlen         = sizeof(unsigned int),
                .mode           = 0644,
                .proc_handler   = proc_douintvec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = &udp_child_hash_entries_max,
        },
        {
                .procname       = "udp_rmem_min",
                .data           = &init_net.ipv4.sysctl_udp_rmem_min,
                .maxlen         = sizeof(init_net.ipv4.sysctl_udp_rmem_min),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ONE
        },
        {
                .procname       = "udp_wmem_min",
                .data           = &init_net.ipv4.sysctl_udp_wmem_min,
                .maxlen         = sizeof(init_net.ipv4.sysctl_udp_wmem_min),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ONE
        },
        {
                .procname       = "fib_notify_on_flag_change",
                .data           = &init_net.ipv4.sysctl_fib_notify_on_flag_change,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_TWO,
        },
        {
                .procname       = "tcp_plb_enabled",
                .data           = &init_net.ipv4.sysctl_tcp_plb_enabled,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE,
        },
        {
                .procname       = "tcp_plb_idle_rehash_rounds",
                .data           = &init_net.ipv4.sysctl_tcp_plb_idle_rehash_rounds,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra2         = &tcp_plb_max_rounds,
        },
        {
                .procname       = "tcp_plb_rehash_rounds",
                .data           = &init_net.ipv4.sysctl_tcp_plb_rehash_rounds,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra2         = &tcp_plb_max_rounds,
        },
        {
                .procname       = "tcp_plb_suspend_rto_sec",
                .data           = &init_net.ipv4.sysctl_tcp_plb_suspend_rto_sec,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "tcp_plb_cong_thresh",
                .data           = &init_net.ipv4.sysctl_tcp_plb_cong_thresh,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = &tcp_plb_max_cong_thresh,
        },
        {
                .procname       = "tcp_syn_linear_timeouts",
                .data           = &init_net.ipv4.sysctl_tcp_syn_linear_timeouts,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = &tcp_syn_linear_timeouts_max,
        },
        {
                .procname       = "tcp_shrink_window",
                .data           = &init_net.ipv4.sysctl_tcp_shrink_window,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE,
        },
        {
                .procname       = "tcp_pingpong_thresh",
                .data           = &init_net.ipv4.sysctl_tcp_pingpong_thresh,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ONE,
        },
        {
                .procname       = "tcp_rto_min_us",
                .data           = &init_net.ipv4.sysctl_tcp_rto_min_us,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ONE,
        },
        {
                .procname       = "tcp_rto_max_ms",
                .data           = &init_net.ipv4.sysctl_tcp_rto_max_ms,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ONE_THOUSAND,
                .extra2         = &tcp_rto_max_max,
        },
};

static __net_init int ipv4_sysctl_init_net(struct net *net)
{
        size_t table_size = ARRAY_SIZE(ipv4_net_table);
        struct ctl_table *table;

        table = ipv4_net_table;
        if (!net_eq(net, &init_net)) {
                int i;

                table = kmemdup(table, sizeof(ipv4_net_table), GFP_KERNEL);
                if (!table)
                        goto err_alloc;

                for (i = 0; i < table_size; i++) {
                        if (table[i].data) {
                                /* Update the variables to point into
                                 * the current struct net
                                 */
                                table[i].data += (void *)net - (void *)&init_net;
                        } else {
                                /* Entries without data pointer are global;
                                 * Make them read-only in non-init_net ns
                                 */
                                table[i].mode &= ~0222;
                        }
                }
        }

        net->ipv4.ipv4_hdr = register_net_sysctl_sz(net, "net/ipv4", table,
                                                    table_size);
        if (!net->ipv4.ipv4_hdr)
                goto err_reg;

        net->ipv4.sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
        if (!net->ipv4.sysctl_local_reserved_ports)
                goto err_ports;

        proc_fib_multipath_hash_set_seed(net, 0);

        return 0;

err_ports:
        unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
err_reg:
        if (!net_eq(net, &init_net))
                kfree(table);
err_alloc:
        return -ENOMEM;
}

static __net_exit void ipv4_sysctl_exit_net(struct net *net)
{
        const struct ctl_table *table;

        kfree(net->ipv4.sysctl_local_reserved_ports);
        table = net->ipv4.ipv4_hdr->ctl_table_arg;
        unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
        kfree(table);
}

static __net_initdata struct pernet_operations ipv4_sysctl_ops = {
        .init = ipv4_sysctl_init_net,
        .exit = ipv4_sysctl_exit_net,
};

static __init int sysctl_ipv4_init(void)
{
        struct ctl_table_header *hdr;

        hdr = register_net_sysctl(&init_net, "net/ipv4", ipv4_table);
        if (!hdr)
                return -ENOMEM;

        proc_fib_multipath_hash_init_rand_seed();

        if (register_pernet_subsys(&ipv4_sysctl_ops)) {
                unregister_net_sysctl_table(hdr);
                return -ENOMEM;
        }

        return 0;
}

__initcall(sysctl_ipv4_init);