// 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/mm.h>
  #include <linux/module.h>
  #include <linux/sysctl.h>

  #include <linux/igmp.h>

  #include <linux/inetdevice.h>

  #include <linux/seqlock.h>

  #include <linux/init.h>

  #include <linux/slab.h>

  #include <linux/nsproxy.h>

  #include <linux/swap.h>

  #include <net/snmp.h>

  #include <net/icmp.h>

  #include <net/ip.h>
  #include <net/route.h>
  #include <net/tcp.h>

  #include <net/udp.h>

  #include <net/cipso_ipv4.h>

  #include <net/inet_frag.h>

  #include <net/ping.h>

  #include <net/protocol.h>

  #include <net/netevent.h>

  static int two = 2;

  static int four = 4;

  static int thousand = 1000;

  static int gso_max_segs = GSO_MAX_SEGS;

  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_min_snd_mss_min = TCP_MIN_SND_MSS;
  static int tcp_min_snd_mss_max = 65535;

  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 ip_ping_group_range_min[] = { 0, 0 };
  static int ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX };

  static int comp_sack_nr_max = 255;

  static u32 u32_max_div_HZ = UINT_MAX / HZ;

  static int one_day_secs = 24 * 3600;

  /* obsolete */
  static int sysctl_tcp_low_latency __read_mostly;

  /* Update system visible IP port range */

  static void set_local_port_range(struct net *net, int range[2])

  {

  	bool same_parity = !((range[0] ^ range[1]) & 1);

  	write_seqlock_bh(&net->ipv4.ip_local_ports.lock);

  	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.
  ");
  	}

  	net->ipv4.ip_local_ports.range[0] = range[0];
  	net->ipv4.ip_local_ports.range[1] = range[1];

  	write_sequnlock_bh(&net->ipv4.ip_local_ports.lock);

  }
  
  /* Validate changes from /proc interface. */

  static int ipv4_local_port_range(struct ctl_table *table, int write,

  				 void *buffer, size_t *lenp, loff_t *ppos)

  {

  	struct net *net =

  		container_of(table->data, struct net, ipv4.ip_local_ports.range);

  	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] < net->ipv4.sysctl_ip_prot_sock))

  			ret = -EINVAL;
  		else

  			set_local_port_range(net, range);

  	}
  
  	return ret;
  }

  /* Validate changes from /proc interface. */
  static int ipv4_privileged_ports(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 = 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
  			net->ipv4.sysctl_ip_prot_sock = pports;
  	}
  
  	return ret;
  }

  static void inet_get_ping_group_range_table(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(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(struct ctl_table *table, int write,

  				 void *buffer, size_t *lenp, loff_t *ppos)

  {

  	struct user_namespace *user_ns = current_user_ns();

  	int ret;

  	gid_t 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_dointvec_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(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_dointvec_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(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(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(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
  ",
  		 user_key[0], user_key[1], user_key[2], user_key[3], buf, ret);
  
  	return ret;
  }

  static int proc_tcp_fastopen_key(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 void proc_configure_early_demux(int enabled, int protocol)
  {
  	struct net_protocol *ipprot;
  #if IS_ENABLED(CONFIG_IPV6)
  	struct inet6_protocol *ip6prot;
  #endif

  	rcu_read_lock();

  	ipprot = rcu_dereference(inet_protos[protocol]);
  	if (ipprot)
  		ipprot->early_demux = enabled ? ipprot->early_demux_handler :
  						NULL;
  
  #if IS_ENABLED(CONFIG_IPV6)
  	ip6prot = rcu_dereference(inet6_protos[protocol]);
  	if (ip6prot)
  		ip6prot->early_demux = enabled ? ip6prot->early_demux_handler :
  						 NULL;
  #endif

  	rcu_read_unlock();

  }
  
  static int proc_tcp_early_demux(struct ctl_table *table, int write,

  				void *buffer, size_t *lenp, loff_t *ppos)

  {
  	int ret = 0;
  
  	ret = proc_dointvec(table, write, buffer, lenp, ppos);
  
  	if (write && !ret) {
  		int enabled = init_net.ipv4.sysctl_tcp_early_demux;
  
  		proc_configure_early_demux(enabled, IPPROTO_TCP);
  	}
  
  	return ret;
  }
  
  static int proc_udp_early_demux(struct ctl_table *table, int write,

  				void *buffer, size_t *lenp, loff_t *ppos)

  {
  	int ret = 0;
  
  	ret = proc_dointvec(table, write, buffer, lenp, ppos);
  
  	if (write && !ret) {
  		int enabled = init_net.ipv4.sysctl_udp_early_demux;
  
  		proc_configure_early_demux(enabled, IPPROTO_UDP);
  	}
  
  	return ret;
  }

  static int proc_tfo_blackhole_detect_timeout(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(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;
  }

  #ifdef CONFIG_IP_ROUTE_MULTIPATH
  static int proc_fib_multipath_hash_policy(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_dointvec_minmax(table, write, buffer, lenp, ppos);
  	if (write && ret == 0)

  		call_netevent_notifiers(NETEVENT_IPV4_MPATH_HASH_UPDATE, net);

  
  	return ret;
  }
  #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	= "icmp_msgs_per_sec",
  		.data		= &sysctl_icmp_msgs_per_sec,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= SYSCTL_ZERO,

  	},
  	{
  		.procname	= "icmp_msgs_burst",
  		.data		= &sysctl_icmp_msgs_burst,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= SYSCTL_ZERO,

  	},
  	{

  		.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,
  	},

  	{
  		.procname	= "tcp_rx_skb_cache",
  		.data		= &tcp_rx_skb_cache_key.key,
  		.mode		= 0644,
  		.proc_handler	= proc_do_static_key,
  	},

  	{
  		.procname	= "tcp_tx_skb_cache",
  		.data		= &tcp_tx_skb_cache_key.key,
  		.mode		= 0644,
  		.proc_handler	= proc_do_static_key,
  	},

  	{ }

  };

  static struct ctl_table ipv4_net_table[] = {
  	{

  		.procname	= "icmp_echo_ignore_all",
  		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_all,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "icmp_echo_ignore_broadcasts",
  		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_broadcasts,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "icmp_ignore_bogus_error_responses",
  		.data		= &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "icmp_errors_use_inbound_ifaddr",
  		.data		= &init_net.ipv4.sysctl_icmp_errors_use_inbound_ifaddr,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.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	= "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(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= SYSCTL_ZERO,
  		.extra2		= SYSCTL_ONE,

  	},
  #endif

  	{

  		.procname	= "tcp_ecn",
  		.data		= &init_net.ipv4.sysctl_tcp_ecn,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},
  	{

  		.procname	= "tcp_ecn_fallback",
  		.data		= &init_net.ipv4.sysctl_tcp_ecn_fallback,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},
  	{

  		.procname	= "ip_dynaddr",
  		.data		= &init_net.ipv4.sysctl_ip_dynaddr,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},
  	{

  		.procname	= "ip_early_demux",
  		.data		= &init_net.ipv4.sysctl_ip_early_demux,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},
  	{

  		.procname       = "udp_early_demux",
  		.data           = &init_net.ipv4.sysctl_udp_early_demux,
  		.maxlen         = sizeof(int),
  		.mode           = 0644,
  		.proc_handler   = proc_udp_early_demux
  	},
  	{
  		.procname       = "tcp_early_demux",
  		.data           = &init_net.ipv4.sysctl_tcp_early_demux,
  		.maxlen         = sizeof(int),
  		.mode           = 0644,
  		.proc_handler   = proc_tcp_early_demux
  	},
  	{

  		.procname       = "nexthop_compat_mode",
  		.data           = &init_net.ipv4.sysctl_nexthop_compat_mode,
  		.maxlen         = sizeof(int),
  		.mode           = 0644,
  		.proc_handler   = proc_dointvec_minmax,
  		.extra1		= SYSCTL_ZERO,
  		.extra2		= SYSCTL_ONE,
  	},
  	{

  		.procname	= "ip_default_ttl",
  		.data		= &init_net.ipv4.sysctl_ip_default_ttl,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,
  		.extra1		= &ip_ttl_min,
  		.extra2		= &ip_ttl_max,
  	},
  	{

  		.procname	= "ip_local_port_range",

  		.maxlen		= sizeof(init_net.ipv4.ip_local_ports.range),
  		.data		= &init_net.ipv4.ip_local_ports.range,

  		.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(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  	{
  		.procname	= "ip_forward_use_pmtu",
  		.data		= &init_net.ipv4.sysctl_ip_fwd_use_pmtu,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},

  	{

  		.procname	= "ip_forward_update_priority",
  		.data		= &init_net.ipv4.sysctl_ip_fwd_update_priority,
  		.maxlen		= sizeof(int),
  		.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(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},
  	{

  		.procname	= "ip_autobind_reuse",
  		.data		= &init_net.ipv4.sysctl_ip_autobind_reuse,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,
  		.extra1         = SYSCTL_ZERO,
  		.extra2         = SYSCTL_ONE,
  	},
  	{

  		.procname	= "fwmark_reflect",
  		.data		= &init_net.ipv4.sysctl_fwmark_reflect,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},

  	{
  		.procname	= "tcp_fwmark_accept",
  		.data		= &init_net.ipv4.sysctl_tcp_fwmark_accept,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},

  #ifdef CONFIG_NET_L3_MASTER_DEV
  	{
  		.procname	= "tcp_l3mdev_accept",
  		.data		= &init_net.ipv4.sysctl_tcp_l3mdev_accept,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= SYSCTL_ZERO,
  		.extra2		= SYSCTL_ONE,

  	},
  #endif

  	{
  		.procname	= "tcp_mtu_probing",
  		.data		= &init_net.ipv4.sysctl_tcp_mtu_probing,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},
  	{
  		.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(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  	{

  		.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(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  	{
  		.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(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_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(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  #ifdef CONFIG_SYN_COOKIES
  	{
  		.procname	= "tcp_syncookies",
  		.data		= &init_net.ipv4.sysctl_tcp_syncookies,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},
  #endif

  	{
  		.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(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,
  		.extra2		= &tcp_retr1_max
  	},

  	{
  		.procname	= "tcp_retries2",
  		.data		= &init_net.ipv4.sysctl_tcp_retries2,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  	{
  		.procname	= "tcp_orphan_retries",
  		.data		= &init_net.ipv4.sysctl_tcp_orphan_retries,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  	{
  		.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(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= SYSCTL_ZERO,

  		.extra2		= &two,

  	},

  	{
  		.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	= "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(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= SYSCTL_ZERO,
  		.extra2		= SYSCTL_ONE,

  	},
  	{
  		.procname	= "fib_multipath_hash_policy",
  		.data		= &init_net.ipv4.sysctl_fib_multipath_hash_policy,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_fib_multipath_hash_policy,

  		.extra1		= SYSCTL_ZERO,

  		.extra2		= &two,

  	},
  #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(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= SYSCTL_ZERO,
  		.extra2		= SYSCTL_ONE,

  	},
  #endif

  	{
  		.procname	= "tcp_sack",
  		.data		= &init_net.ipv4.sysctl_tcp_sack,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  	{
  		.procname	= "tcp_window_scaling",
  		.data		= &init_net.ipv4.sysctl_tcp_window_scaling,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  	{
  		.procname	= "tcp_timestamps",
  		.data		= &init_net.ipv4.sysctl_tcp_timestamps,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  	{
  		.procname	= "tcp_early_retrans",
  		.data		= &init_net.ipv4.sysctl_tcp_early_retrans,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= SYSCTL_ZERO,

  		.extra2		= &four,
  	},

  	{
  		.procname	= "tcp_recovery",
  		.data		= &init_net.ipv4.sysctl_tcp_recovery,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},

  	{
  		.procname       = "tcp_thin_linear_timeouts",
  		.data           = &init_net.ipv4.sysctl_tcp_thin_linear_timeouts,
  		.maxlen         = sizeof(int),
  		.mode           = 0644,
  		.proc_handler   = proc_dointvec
  	},

  	{
  		.procname	= "tcp_slow_start_after_idle",
  		.data		= &init_net.ipv4.sysctl_tcp_slow_start_after_idle,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  	{
  		.procname	= "tcp_retrans_collapse",
  		.data		= &init_net.ipv4.sysctl_tcp_retrans_collapse,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  	{
  		.procname	= "tcp_stdurg",
  		.data		= &init_net.ipv4.sysctl_tcp_stdurg,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  	{
  		.procname	= "tcp_rfc1337",
  		.data		= &init_net.ipv4.sysctl_tcp_rfc1337,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  	{
  		.procname	= "tcp_abort_on_overflow",
  		.data		= &init_net.ipv4.sysctl_tcp_abort_on_overflow,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  	{
  		.procname	= "tcp_fack",
  		.data		= &init_net.ipv4.sysctl_tcp_fack,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  	{
  		.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(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  	{
  		.procname	= "tcp_app_win",
  		.data		= &init_net.ipv4.sysctl_tcp_app_win,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  	{
  		.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(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  	{
  		.procname	= "tcp_no_metrics_save",
  		.data		= &init_net.ipv4.sysctl_tcp_nometrics_save,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},

  	{

  		.procname	= "tcp_no_ssthresh_metrics_save",
  		.data		= &init_net.ipv4.sysctl_tcp_no_ssthresh_metrics_save,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,
  		.extra1		= SYSCTL_ZERO,
  		.extra2		= SYSCTL_ONE,
  	},
  	{

  		.procname	= "tcp_moderate_rcvbuf",
  		.data		= &init_net.ipv4.sysctl_tcp_moderate_rcvbuf,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},

  	{
  		.procname	= "tcp_tso_win_divisor",
  		.data		= &init_net.ipv4.sysctl_tcp_tso_win_divisor,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},

  	{
  		.procname	= "tcp_workaround_signed_windows",
  		.data		= &init_net.ipv4.sysctl_tcp_workaround_signed_windows,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},

  	{
  		.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(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= SYSCTL_ONE,

  		.extra2		= &gso_max_segs,
  	},

  	{
  		.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(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_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		= &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		= &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_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(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= SYSCTL_ZERO,

  		.extra2		= &comp_sack_nr_max,
  	},
  	{

  		.procname       = "tcp_reflect_tos",
  		.data           = &init_net.ipv4.sysctl_tcp_reflect_tos,
  		.maxlen         = sizeof(int),
  		.mode           = 0644,
  		.proc_handler   = proc_dointvec_minmax,
  		.extra1         = SYSCTL_ZERO,
  		.extra2         = SYSCTL_ONE,
  	},
  	{

  		.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

  	},

  	{ }
  };

  static __net_init int ipv4_sysctl_init_net(struct net *net)
  {

  	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;

  		/* Update the variables to point into the current struct net */
  		for (i = 0; i < ARRAY_SIZE(ipv4_net_table) - 1; i++)
  			table[i].data += (void *)net - (void *)&init_net;

  	}

  	net->ipv4.ipv4_hdr = register_net_sysctl(net, "net/ipv4", table);

  	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;

  	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)
  {

  	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;
  
  	if (register_pernet_subsys(&ipv4_sysctl_ops)) {

  		unregister_net_sysctl_table(hdr);

  		return -ENOMEM;
  	}
  
  	return 0;

  }
  
  __initcall(sysctl_ipv4_init);