[linux-2.6-block.git] / net / sysctl_net.c

/* -*- 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

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_header *head,
			       struct ctl_table *table)
{
	struct net *net = container_of(head->set, struct net, sysctls);
	kuid_t root_uid = make_kuid(net->user_ns, 0);
	kgid_t root_gid = make_kgid(net->user_ns, 0);

	/* Allow network administrator to have same access as root. */
	if (ns_capable(net->user_ns, CAP_NET_ADMIN) ||
	    uid_eq(root_uid, current_euid())) {
		int mode = (table->mode >> 6) & 7;
		return (mode << 6) | (mode << 3) | mode;
	}
	/* Allow netns root group to have the same access as the root group */
	if (in_egroup_p(root_gid)) {
		int mode = (table->mode >> 3) & 7;
		return (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_init sysctl_net_init(struct net *net)
{
	setup_sysctl_set(&net->sysctls, &net_sysctl_root, is_seen);
	return 0;
}

static void __net_exit sysctl_net_exit(struct net *net)
{
	retire_sysctl_set(&net->sysctls);
}

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

static struct ctl_table_header *net_header;
__init int net_sysctl_init(void)
{
	static struct ctl_table empty[1];
	int ret = -ENOMEM;
	/* Avoid limitations in the sysctl implementation by
	 * registering "/proc/sys/net" as an empty directory not in a
	 * network namespace.
	 */
	net_header = register_sysctl("net", empty);
	if (!net_header)
		goto out;
	ret = register_pernet_subsys(&sysctl_pernet_ops);
	if (ret)
		goto out1;
	register_sysctl_root(&net_sysctl_root);
out:
	return ret;
out1:
	unregister_sysctl_table(net_header);
	net_header = NULL;
	goto out;
}

struct ctl_table_header *register_net_sysctl(struct net *net,
	const char *path, struct ctl_table *table)
{
	return __register_sysctl_table(&net->sysctls, path, table);
}
EXPORT_SYMBOL_GPL(register_net_sysctl);

void unregister_net_sysctl_table(struct ctl_table_header *header)
{
	unregister_sysctl_table(header);
}
EXPORT_SYMBOL_GPL(unregister_net_sysctl_table);
Commit	Line	Data
	1	/* -- linux-c --
	2	* sysctl_net.c: sysctl interface to net subsystem.
	3	*
	4	* Begun April 1, 1996, Mike Shaver.
	5	* Added /proc/sys/net directories for each protocol family. [MS]
	6	*
	7	* Revision 1.2 1996/05/08 20:24:40 shaver
	8	* Added bits for NET_BRIDGE and the NET_IPV4_ARP stuff and
	9	* NET_IPV4_IP_FORWARD.
	10	*
	11	*
	12	*/
	13
	14	#include <linux/mm.h>
	15	#include <linux/export.h>
	16	#include <linux/sysctl.h>
	17	#include <linux/nsproxy.h>
	18
	19	#include <net/sock.h>
	20
	21	#ifdef CONFIG_INET
	22	#include <net/ip.h>
	23	#endif
	24
	25	#ifdef CONFIG_NET
	26	#include <linux/if_ether.h>
	27	#endif
	28
	29	static struct ctl_table_set *
	30	net_ctl_header_lookup(struct ctl_table_root root, struct nsproxy namespaces)
	31	{
	32	return &namespaces->net_ns->sysctls;
	33	}
	34
	35	static int is_seen(struct ctl_table_set *set)
	36	{
	37	return &current->nsproxy->net_ns->sysctls == set;
	38	}
	39
	40	/* Return standard mode bits for table entry. */
	41	static int net_ctl_permissions(struct ctl_table_header *head,
	42	struct ctl_table *table)
	43	{
	44	struct net *net = container_of(head->set, struct net, sysctls);
	45	kuid_t root_uid = make_kuid(net->user_ns, 0);
	46	kgid_t root_gid = make_kgid(net->user_ns, 0);
	47
	48	/* Allow network administrator to have same access as root. */
	49	if (ns_capable(net->user_ns, CAP_NET_ADMIN) \|\|
	50	uid_eq(root_uid, current_euid())) {
	51	int mode = (table->mode >> 6) & 7;
	52	return (mode << 6) \| (mode << 3) \| mode;
	53	}
	54	/* Allow netns root group to have the same access as the root group */
	55	if (in_egroup_p(root_gid)) {
	56	int mode = (table->mode >> 3) & 7;
	57	return (mode << 3) \| mode;
	58	}
	59	return table->mode;
	60	}
	61
	62	static struct ctl_table_root net_sysctl_root = {
	63	.lookup = net_ctl_header_lookup,
	64	.permissions = net_ctl_permissions,
	65	};
	66
	67	static int __net_init sysctl_net_init(struct net *net)
	68	{
	69	setup_sysctl_set(&net->sysctls, &net_sysctl_root, is_seen);
	70	return 0;
	71	}
	72
	73	static void __net_exit sysctl_net_exit(struct net *net)
	74	{
	75	retire_sysctl_set(&net->sysctls);
	76	}
	77
	78	static struct pernet_operations sysctl_pernet_ops = {
	79	.init = sysctl_net_init,
	80	.exit = sysctl_net_exit,
	81	};
	82
	83	static struct ctl_table_header *net_header;
	84	__init int net_sysctl_init(void)
	85	{
	86	static struct ctl_table empty[1];
	87	int ret = -ENOMEM;
	88	/* Avoid limitations in the sysctl implementation by
	89	* registering "/proc/sys/net" as an empty directory not in a
	90	* network namespace.
	91	*/
	92	net_header = register_sysctl("net", empty);
	93	if (!net_header)
	94	goto out;
	95	ret = register_pernet_subsys(&sysctl_pernet_ops);
	96	if (ret)
	97	goto out1;
	98	register_sysctl_root(&net_sysctl_root);
	99	out:
	100	return ret;
	101	out1:
	102	unregister_sysctl_table(net_header);
	103	net_header = NULL;
	104	goto out;
	105	}
	106
	107	struct ctl_table_header register_net_sysctl(struct net net,
	108	const char path, struct ctl_table table)
	109	{
	110	return __register_sysctl_table(&net->sysctls, path, table);
	111	}
	112	EXPORT_SYMBOL_GPL(register_net_sysctl);
	113
	114	void unregister_net_sysctl_table(struct ctl_table_header *header)
	115	{
	116	unregister_sysctl_table(header);
	117	}
	118	EXPORT_SYMBOL_GPL(unregister_net_sysctl_table);