/*
   * 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/tcp_memcontrol.h>

  static int zero;

  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 ip_ttl_min = 1;
  static int ip_ttl_max = 255;

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

  /* Update system visible IP port range */
  static void set_local_port_range(int range[2])
  {

  	write_seqlock(&sysctl_local_ports.lock);
  	sysctl_local_ports.range[0] = range[0];
  	sysctl_local_ports.range[1] = range[1];
  	write_sequnlock(&sysctl_local_ports.lock);

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

  static int ipv4_local_port_range(ctl_table *table, int write,

  				 void __user *buffer,
  				 size_t *lenp, loff_t *ppos)
  {
  	int ret;

  	int range[2];

  	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(range, range + 1);

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

  
  	if (write && ret == 0) {

  		if (range[1] < range[0])

  			ret = -EINVAL;
  		else
  			set_local_port_range(range);
  	}
  
  	return ret;
  }

  static void inet_get_ping_group_range_table(struct ctl_table *table, gid_t *low, gid_t *high)

  {
  	gid_t *data = table->data;
  	unsigned seq;
  	do {
  		seq = read_seqbegin(&sysctl_local_ports.lock);
  
  		*low = data[0];
  		*high = data[1];
  	} while (read_seqretry(&sysctl_local_ports.lock, seq));
  }
  
  /* Update system visible IP port range */

  static void set_ping_group_range(struct ctl_table *table, gid_t range[2])

  {
  	gid_t *data = table->data;
  	write_seqlock(&sysctl_local_ports.lock);
  	data[0] = range[0];
  	data[1] = range[1];
  	write_sequnlock(&sysctl_local_ports.lock);
  }
  
  /* Validate changes from /proc interface. */
  static int ipv4_ping_group_range(ctl_table *table, int write,
  				 void __user *buffer,
  				 size_t *lenp, loff_t *ppos)
  {
  	int ret;
  	gid_t range[2];
  	ctl_table tmp = {
  		.data = &range,
  		.maxlen = sizeof(range),
  		.mode = table->mode,
  		.extra1 = &ip_ping_group_range_min,
  		.extra2 = &ip_ping_group_range_max,
  	};
  
  	inet_get_ping_group_range_table(table, range, range + 1);
  	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
  
  	if (write && ret == 0)
  		set_ping_group_range(table, range);
  
  	return ret;
  }

  static int proc_tcp_congestion_control(ctl_table *ctl, int write,

  				       void __user *buffer, size_t *lenp, loff_t *ppos)
  {
  	char val[TCP_CA_NAME_MAX];
  	ctl_table tbl = {
  		.data = val,
  		.maxlen = TCP_CA_NAME_MAX,
  	};
  	int ret;
  
  	tcp_get_default_congestion_control(val);

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

  	if (write && ret == 0)
  		ret = tcp_set_default_congestion_control(val);
  	return ret;
  }

  static int proc_tcp_available_congestion_control(ctl_table *ctl,

  						 int write,

  						 void __user *buffer, size_t *lenp,
  						 loff_t *ppos)
  {
  	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(ctl_table *ctl,

  					   int write,

  					   void __user *buffer, size_t *lenp,
  					   loff_t *ppos)
  {
  	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 ipv4_tcp_mem(ctl_table *ctl, int write,
  			   void __user *buffer, size_t *lenp,
  			   loff_t *ppos)
  {
  	int ret;
  	unsigned long vec[3];
  	struct net *net = current->nsproxy->net_ns;

  #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
  	struct mem_cgroup *memcg;
  #endif

  
  	ctl_table tmp = {
  		.data = &vec,
  		.maxlen = sizeof(vec),
  		.mode = ctl->mode,
  	};
  
  	if (!write) {
  		ctl->data = &net->ipv4.sysctl_tcp_mem;
  		return proc_doulongvec_minmax(ctl, write, buffer, lenp, ppos);
  	}
  
  	ret = proc_doulongvec_minmax(&tmp, write, buffer, lenp, ppos);
  	if (ret)
  		return ret;

  #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
  	rcu_read_lock();
  	memcg = mem_cgroup_from_task(current);
  
  	tcp_prot_mem(memcg, vec[0], 0);
  	tcp_prot_mem(memcg, vec[1], 1);
  	tcp_prot_mem(memcg, vec[2], 2);
  	rcu_read_unlock();
  #endif

  	net->ipv4.sysctl_tcp_mem[0] = vec[0];
  	net->ipv4.sysctl_tcp_mem[1] = vec[1];
  	net->ipv4.sysctl_tcp_mem[2] = vec[2];
  
  	return 0;
  }

  static struct ctl_table ipv4_table[] = {

  	{

  		.procname	= "tcp_timestamps",
  		.data		= &sysctl_tcp_timestamps,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},

  	{

  		.procname	= "tcp_window_scaling",
  		.data		= &sysctl_tcp_window_scaling,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},

  	{

  		.procname	= "tcp_sack",
  		.data		= &sysctl_tcp_sack,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},

  	{

  		.procname	= "tcp_retrans_collapse",
  		.data		= &sysctl_tcp_retrans_collapse,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},

  	{

  		.procname	= "ip_default_ttl",

  		.data		= &sysctl_ip_default_ttl,

  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec_minmax,
  		.extra1		= &ip_ttl_min,
  		.extra2		= &ip_ttl_max,

  	},

  	{

  		.procname	= "ip_no_pmtu_disc",
  		.data		= &ipv4_config.no_pmtu_disc,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "ip_nonlocal_bind",
  		.data		= &sysctl_ip_nonlocal_bind,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_syn_retries",
  		.data		= &sysctl_tcp_syn_retries,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_synack_retries",
  		.data		= &sysctl_tcp_synack_retries,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_max_orphans",
  		.data		= &sysctl_tcp_max_orphans,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_max_tw_buckets",

  		.data		= &tcp_death_row.sysctl_max_tw_buckets,

  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "ip_dynaddr",
  		.data		= &sysctl_ip_dynaddr,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_keepalive_time",
  		.data		= &sysctl_tcp_keepalive_time,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec_jiffies,

  	},
  	{

  		.procname	= "tcp_keepalive_probes",
  		.data		= &sysctl_tcp_keepalive_probes,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_keepalive_intvl",
  		.data		= &sysctl_tcp_keepalive_intvl,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec_jiffies,

  	},
  	{

  		.procname	= "tcp_retries1",
  		.data		= &sysctl_tcp_retries1,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec_minmax,

  		.extra2		= &tcp_retr1_max
  	},
  	{

  		.procname	= "tcp_retries2",
  		.data		= &sysctl_tcp_retries2,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_fin_timeout",
  		.data		= &sysctl_tcp_fin_timeout,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec_jiffies,

  	},
  #ifdef CONFIG_SYN_COOKIES
  	{

  		.procname	= "tcp_syncookies",
  		.data		= &sysctl_tcp_syncookies,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  #endif
  	{

  		.procname	= "tcp_tw_recycle",

  		.data		= &tcp_death_row.sysctl_tw_recycle,

  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_abort_on_overflow",
  		.data		= &sysctl_tcp_abort_on_overflow,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_stdurg",
  		.data		= &sysctl_tcp_stdurg,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_rfc1337",
  		.data		= &sysctl_tcp_rfc1337,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_max_syn_backlog",
  		.data		= &sysctl_max_syn_backlog,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "ip_local_port_range",

  		.data		= &sysctl_local_ports.range,
  		.maxlen		= sizeof(sysctl_local_ports.range),

  		.mode		= 0644,

  		.proc_handler	= ipv4_local_port_range,

  	},

  	{
  		.procname	= "ip_local_reserved_ports",
  		.data		= NULL, /* initialized in sysctl_ipv4_init */
  		.maxlen		= 65536,
  		.mode		= 0644,
  		.proc_handler	= proc_do_large_bitmap,
  	},

  	{

  		.procname	= "igmp_max_memberships",
  		.data		= &sysctl_igmp_max_memberships,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},

  	{

  		.procname	= "igmp_max_msf",
  		.data		= &sysctl_igmp_max_msf,
  		.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_orphan_retries",
  		.data		= &sysctl_tcp_orphan_retries,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_fack",
  		.data		= &sysctl_tcp_fack,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_reordering",
  		.data		= &sysctl_tcp_reordering,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_ecn",
  		.data		= &sysctl_tcp_ecn,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_dsack",
  		.data		= &sysctl_tcp_dsack,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_wmem",
  		.data		= &sysctl_tcp_wmem,
  		.maxlen		= sizeof(sysctl_tcp_wmem),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_rmem",
  		.data		= &sysctl_tcp_rmem,
  		.maxlen		= sizeof(sysctl_tcp_rmem),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_app_win",
  		.data		= &sysctl_tcp_app_win,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_adv_win_scale",
  		.data		= &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_tw_reuse",
  		.data		= &sysctl_tcp_tw_reuse,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_frto",
  		.data		= &sysctl_tcp_frto,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_frto_response",
  		.data		= &sysctl_tcp_frto_response,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_low_latency",
  		.data		= &sysctl_tcp_low_latency,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  	{

  		.procname	= "tcp_no_metrics_save",
  		.data		= &sysctl_tcp_nometrics_save,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec,

  	},
  	{

  		.procname	= "tcp_moderate_rcvbuf",
  		.data		= &sysctl_tcp_moderate_rcvbuf,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec,

  	},
  	{

  		.procname	= "tcp_tso_win_divisor",
  		.data		= &sysctl_tcp_tso_win_divisor,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec,

  	},
  	{

  		.procname	= "tcp_congestion_control",

  		.mode		= 0644,

  		.maxlen		= TCP_CA_NAME_MAX,

  		.proc_handler	= proc_tcp_congestion_control,

  	},

  	{

  		.procname	= "tcp_abc",
  		.data		= &sysctl_tcp_abc,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec,

  	},

  	{

  		.procname	= "tcp_mtu_probing",
  		.data		= &sysctl_tcp_mtu_probing,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec,

  	},
  	{

  		.procname	= "tcp_base_mss",
  		.data		= &sysctl_tcp_base_mss,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec,

  	},

  	{

  		.procname	= "tcp_workaround_signed_windows",
  		.data		= &sysctl_tcp_workaround_signed_windows,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},

  #ifdef CONFIG_NET_DMA
  	{

  		.procname	= "tcp_dma_copybreak",
  		.data		= &sysctl_tcp_dma_copybreak,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},
  #endif

  	{

  		.procname	= "tcp_slow_start_after_idle",
  		.data		= &sysctl_tcp_slow_start_after_idle,
  		.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_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_max_ssthresh",
  		.data		= &sysctl_tcp_max_ssthresh,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec,

  	},

  	{

  		.procname	= "tcp_cookie_size",
  		.data		= &sysctl_tcp_cookie_size,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},
  	{

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

          {
  		.procname       = "tcp_thin_dupack",
  		.data           = &sysctl_tcp_thin_dupack,
  		.maxlen         = sizeof(int),
  		.mode           = 0644,
  		.proc_handler   = proc_dointvec
  	},

  	{

  		.procname	= "udp_mem",
  		.data		= &sysctl_udp_mem,
  		.maxlen		= sizeof(sysctl_udp_mem),
  		.mode		= 0644,

  		.proc_handler	= proc_doulongvec_minmax,

  	},
  	{

  		.procname	= "udp_rmem_min",
  		.data		= &sysctl_udp_rmem_min,
  		.maxlen		= sizeof(sysctl_udp_rmem_min),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= &zero
  	},
  	{

  		.procname	= "udp_wmem_min",
  		.data		= &sysctl_udp_wmem_min,
  		.maxlen		= sizeof(sysctl_udp_wmem_min),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= &zero
  	},

  	{ }

  };

  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	= "rt_cache_rebuild_count",
  		.data		= &init_net.ipv4.sysctl_rt_cache_rebuild_count,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},

  	{
  		.procname	= "ping_group_range",
  		.data		= &init_net.ipv4.sysctl_ping_group_range,
  		.maxlen		= sizeof(init_net.ipv4.sysctl_ping_group_range),
  		.mode		= 0644,
  		.proc_handler	= ipv4_ping_group_range,
  	},

  	{
  		.procname	= "tcp_mem",
  		.maxlen		= sizeof(init_net.ipv4.sysctl_tcp_mem),
  		.mode		= 0644,
  		.proc_handler	= ipv4_tcp_mem,
  	},

  	{ }
  };

  struct ctl_path net_ipv4_ctl_path[] = {

  	{ .procname = "net", },
  	{ .procname = "ipv4", },

  	{ },
  };

  EXPORT_SYMBOL_GPL(net_ipv4_ctl_path);

  static __net_init int ipv4_sysctl_init_net(struct net *net)
  {

  	struct ctl_table *table;

  	unsigned long limit;

  
  	table = ipv4_net_table;

  	if (!net_eq(net, &init_net)) {

  		table = kmemdup(table, sizeof(ipv4_net_table), GFP_KERNEL);
  		if (table == NULL)
  			goto err_alloc;
  
  		table[0].data =
  			&net->ipv4.sysctl_icmp_echo_ignore_all;
  		table[1].data =
  			&net->ipv4.sysctl_icmp_echo_ignore_broadcasts;
  		table[2].data =
  			&net->ipv4.sysctl_icmp_ignore_bogus_error_responses;
  		table[3].data =
  			&net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr;
  		table[4].data =
  			&net->ipv4.sysctl_icmp_ratelimit;
  		table[5].data =
  			&net->ipv4.sysctl_icmp_ratemask;

  		table[6].data =
  			&net->ipv4.sysctl_rt_cache_rebuild_count;

  		table[7].data =
  			&net->ipv4.sysctl_ping_group_range;

  	}

  	/*
  	 * Sane defaults - nobody may create ping sockets.
  	 * Boot scripts should set this to distro-specific group.
  	 */
  	net->ipv4.sysctl_ping_group_range[0] = 1;
  	net->ipv4.sysctl_ping_group_range[1] = 0;

  	net->ipv4.sysctl_rt_cache_rebuild_count = 4;

  	limit = nr_free_buffer_pages() / 8;
  	limit = max(limit, 128UL);
  	net->ipv4.sysctl_tcp_mem[0] = limit / 4 * 3;
  	net->ipv4.sysctl_tcp_mem[1] = limit;
  	net->ipv4.sysctl_tcp_mem[2] = net->ipv4.sysctl_tcp_mem[0] * 2;

  	net->ipv4.ipv4_hdr = register_net_sysctl_table(net,
  			net_ipv4_ctl_path, table);
  	if (net->ipv4.ipv4_hdr == NULL)
  		goto err_reg;

  	return 0;

  
  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;
  
  	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;

  	struct ctl_table *i;
  
  	for (i = ipv4_table; i->procname; i++) {
  		if (strcmp(i->procname, "ip_local_reserved_ports") == 0) {
  			i->data = sysctl_local_reserved_ports;
  			break;
  		}
  	}
  	if (!i->procname)
  		return -EINVAL;

  	hdr = register_sysctl_paths(net_ipv4_ctl_path, ipv4_table);

  	if (hdr == NULL)
  		return -ENOMEM;
  
  	if (register_pernet_subsys(&ipv4_sysctl_ops)) {
  		unregister_sysctl_table(hdr);
  		return -ENOMEM;
  	}
  
  	return 0;

  }
  
  __initcall(sysctl_ipv4_init);