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 one = 1;
static int four = 4;
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 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 };

/* Update system visible IP port range */
static void set_local_port_range(struct net *net, int range[2])
{
	write_seqlock(&net->ipv4.sysctl_local_ports.lock);
	net->ipv4.sysctl_local_ports.range[0] = range[0];
	net->ipv4.sysctl_local_ports.range[1] = range[1];
	write_sequnlock(&net->ipv4.sysctl_local_ports.lock);
}

/* Validate changes from /proc interface. */
static int ipv4_local_port_range(struct ctl_table *table, int write,
				 void __user *buffer,
				 size_t *lenp, loff_t *ppos)
{
	struct net *net =
		container_of(table->data, struct net, ipv4.sysctl_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) {
		if (range[1] < range[0])
			ret = -EINVAL;
		else
			set_local_port_range(net, range);
	}

	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.sysctl_ping_group_range);
	unsigned int seq;
	do {
		seq = read_seqbegin(&net->ipv4.sysctl_local_ports.lock);

		*low = data[0];
		*high = data[1];
	} while (read_seqretry(&net->ipv4.sysctl_local_ports.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.sysctl_ping_group_range);
	write_seqlock(&net->ipv4.sysctl_local_ports.lock);
	data[0] = low;
	data[1] = high;
	write_sequnlock(&net->ipv4.sysctl_local_ports.lock);
}

/* Validate changes from /proc interface. */
static int ipv4_ping_group_range(struct ctl_table *table, int write,
				 void __user *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);