path: root/net/ipv4/sysctl_net_ipv4.c

/*
 * 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 two = 2;
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 int 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)