Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Open Menu / net / sysctl_net.c
Loading...
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
/* -*- linux-c -*-
 * sysctl_net.c: sysctl interface to net subsystem.
 *
 * Begun April 1, 1996, Mike Shaver.
 * Added /proc/sys/net directories for each protocol family. [MS]
 *
 * Revision 1.2  1996/05/08  20:24:40  shaver
 * Added bits for NET_BRIDGE and the NET_IPV4_ARP stuff and
 * NET_IPV4_IP_FORWARD.
 *
 *
 */

#include <linux/mm.h>
#include <linux/export.h>
#include <linux/sysctl.h>
#include <linux/nsproxy.h>

#include <net/sock.h>

#ifdef CONFIG_INET
#include <net/ip.h>
#endif

#ifdef CONFIG_NET
#include <linux/if_ether.h>
#endif

#ifdef CONFIG_TR
#include <linux/if_tr.h>
#endif

static struct ctl_table_set *
net_ctl_header_lookup(struct ctl_table_root *root, struct nsproxy *namespaces)
{
	return &namespaces->net_ns->sysctls;
}

static int is_seen(struct ctl_table_set *set)
{
	return &current->nsproxy->net_ns->sysctls == set;
}

/* Return standard mode bits for table entry. */
static int net_ctl_permissions(struct ctl_table_root *root,
			       struct nsproxy *nsproxy,
			       struct ctl_table *table)
{
	/* Allow network administrator to have same access as root. */
	if (capable(CAP_NET_ADMIN)) {
		int mode = (table->mode >> 6) & 7;
		return (mode << 6) | (mode << 3) | mode;
	}
	return table->mode;
}

static struct ctl_table_root net_sysctl_root = {
	.lookup = net_ctl_header_lookup,
	.permissions = net_ctl_permissions,
};

static int net_ctl_ro_header_perms(struct ctl_table_root *root,
		struct nsproxy *namespaces, struct ctl_table *table)
{
	if (net_eq(namespaces->net_ns, &init_net))
		return table->mode;
	else
		return table->mode & ~0222;
}

static struct ctl_table_root net_sysctl_ro_root = {
	.permissions = net_ctl_ro_header_perms,
};

static int __net_init sysctl_net_init(struct net *net)
{
	setup_sysctl_set(&net->sysctls,
			 &net_sysctl_ro_root.default_set,
			 is_seen);
	return 0;
}

static void __net_exit sysctl_net_exit(struct net *net)
{
	WARN_ON(!list_empty(&net->sysctls.list));
}

static struct pernet_operations sysctl_pernet_ops = {
	.init = sysctl_net_init,
	.exit = sysctl_net_exit,
};

static __init int sysctl_init(void)
{
	int ret;
	ret = register_pernet_subsys(&sysctl_pernet_ops);
	if (ret)
		goto out;
	register_sysctl_root(&net_sysctl_root);
	setup_sysctl_set(&net_sysctl_ro_root.default_set, NULL, NULL);
	register_sysctl_root(&net_sysctl_ro_root);
out:
	return ret;
}
subsys_initcall(sysctl_init);

struct ctl_table_header *register_net_sysctl_table(struct net *net,
	const struct ctl_path *path, struct ctl_table *table)
{
	struct nsproxy namespaces;
	namespaces = *current->nsproxy;
	namespaces.net_ns = net;
	return __register_sysctl_paths(&net_sysctl_root,
					&namespaces, path, table);
}
EXPORT_SYMBOL_GPL(register_net_sysctl_table);

struct ctl_table_header *register_net_sysctl_rotable(const
		struct ctl_path *path, struct ctl_table *table)
{
	return __register_sysctl_paths(&net_sysctl_ro_root,
			&init_nsproxy, path, table);
}
EXPORT_SYMBOL_GPL(register_net_sysctl_rotable);

void unregister_net_sysctl_table(struct ctl_table_header *header)
{
	unregister_sysctl_table(header);
}
EXPORT_SYMBOL_GPL(unregister_net_sysctl_table);