[linux.git] / fs / proc / proc_net.c

/*
 *  linux/fs/proc/net.c
 *
 *  Copyright (C) 2007
 *
 *  Author: Eric Biederman <[email protected]>
 *
 *  proc net directory handling functions
 */

#include <linux/uaccess.h>

#include <linux/errno.h>
#include <linux/time.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/sched/task.h>
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/mount.h>
#include <linux/nsproxy.h>
#include <linux/uidgid.h>
#include <net/net_namespace.h>
#include <linux/seq_file.h>

#include "internal.h"

static inline struct net *PDE_NET(struct proc_dir_entry *pde)
{
	return pde->parent->data;
}

static struct net *get_proc_net(const struct inode *inode)
{
	return maybe_get_net(PDE_NET(PDE(inode)));
}

static int proc_net_d_revalidate(struct dentry *dentry, unsigned int flags)
{
	return 0;
}

static const struct dentry_operations proc_net_dentry_ops = {
	.d_revalidate	= proc_net_d_revalidate,
	.d_delete	= always_delete_dentry,
};

static void pde_force_lookup(struct proc_dir_entry *pde)
{
	/* /proc/net/ entries can be changed under us by setns(CLONE_NEWNET) */
	pde->proc_dops = &proc_net_dentry_ops;
}

static int seq_open_net(struct inode *inode, struct file *file)
{
	unsigned int state_size = PDE(inode)->state_size;
	struct seq_net_private *p;
	struct net *net;

	WARN_ON_ONCE(state_size < sizeof(*p));

	if (file->f_mode & FMODE_WRITE && !PDE(inode)->write)
		return -EACCES;

	net = get_proc_net(inode);
	if (!net)
		return -ENXIO;

	p = __seq_open_private(file, PDE(inode)->seq_ops, state_size);
	if (!p) {
		put_net(net);
		return -ENOMEM;
	}
#ifdef CONFIG_NET_NS
	p->net = net;
#endif
	return 0;
}

static int seq_release_net(struct inode *ino, struct file *f)
{
	struct seq_file *seq = f->private_data;

	put_net(seq_file_net(seq));
	seq_release_private(ino, f);
	return 0;
}

static const struct file_operations proc_net_seq_fops = {
	.open		= seq_open_net,
	.read		= seq_read,
	.write		= proc_simple_write,
	.llseek		= seq_lseek,
	.release	= seq_release_net,
};

struct proc_dir_entry *proc_create_net_data(const char *name, umode_t mode,
		struct proc_dir_entry *parent, const struct seq_operations *ops,
		unsigned int state_size, void *data)
{
	struct proc_dir_entry *p;

	p = proc_create_reg(name, mode, &parent, data);
	if (!p)
		return NULL;
	pde_force_lookup(p);
	p->proc_fops = &proc_net_seq_fops;
	p->seq_ops = ops;
	p->state_size = state_size;
	return proc_register(parent, p);
}
EXPORT_SYMBOL_GPL(proc_create_net_data);

/**
 * proc_create_net_data_write - Create a writable net_ns-specific proc file
 * @name: The name of the file.
 * @mode: The file's access mode.
 * @parent: The parent directory in which to create.
 * @ops: The seq_file ops with which to read the file.
 * @write: The write method which which to 'modify' the file.
 * @data: Data for retrieval by PDE_DATA().
 *
 * Create a network namespaced proc file in the @parent directory with the
 * specified @name and @mode that allows reading of a file that displays a
 * series of elements and also provides for the file accepting writes that have
 * some arbitrary effect.
 *
 * The functions in the @ops table are used to iterate over items to be
 * presented and extract the readable content using the seq_file interface.
 *
 * The @write function is called with the data copied into a kernel space
 * scratch buffer and has a NUL appended for convenience.  The buffer may be
 * modified by the @write function.  @write should return 0 on success.
 *
 * The @data value is accessible from the @show and @write functions by calling
 * PDE_DATA() on the file inode.  The network namespace must be accessed by
 * calling seq_file_net() on the seq_file struct.
 */
struct proc_dir_entry *proc_create_net_data_write(const char *name, umode_t mode,
						  struct proc_dir_entry *parent,
						  const struct seq_operations *ops,
						  proc_write_t write,
						  unsigned int state_size, void *data)
{
	struct proc_dir_entry *p;

	p = proc_create_reg(name, mode, &parent, data);
	if (!p)
		return NULL;
	pde_force_lookup(p);
	p->proc_fops = &proc_net_seq_fops;
	p->seq_ops = ops;
	p->state_size = state_size;
	p->write = write;
	return proc_register(parent, p);
}
EXPORT_SYMBOL_GPL(proc_create_net_data_write);

static int single_open_net(struct inode *inode, struct file *file)
{
	struct proc_dir_entry *de = PDE(inode);
	struct net *net;
	int err;

	net = get_proc_net(inode);
	if (!net)
		return -ENXIO;

	err = single_open(file, de->single_show, net);
	if (err)
		put_net(net);
	return err;
}

static int single_release_net(struct inode *ino, struct file *f)
{
	struct seq_file *seq = f->private_data;
	put_net(seq->private);
	return single_release(ino, f);
}

static const struct file_operations proc_net_single_fops = {
	.open		= single_open_net,
	.read		= seq_read,
	.write		= proc_simple_write,
	.llseek		= seq_lseek,
	.release	= single_release_net,
};

struct proc_dir_entry *proc_create_net_single(const char *name, umode_t mode,
		struct proc_dir_entry *parent,
		int (*show)(struct seq_file *, void *), void *data)
{
	struct proc_dir_entry *p;

	p = proc_create_reg(name, mode, &parent, data);
	if (!p)
		return NULL;
	pde_force_lookup(p);
	p->proc_fops = &proc_net_single_fops;
	p->single_show = show;
	return proc_register(parent, p);
}
EXPORT_SYMBOL_GPL(proc_create_net_single);

/**
 * proc_create_net_single_write - Create a writable net_ns-specific proc file
 * @name: The name of the file.
 * @mode: The file's access mode.
 * @parent: The parent directory in which to create.
 * @show: The seqfile show method with which to read the file.
 * @write: The write method which which to 'modify' the file.
 * @data: Data for retrieval by PDE_DATA().
 *
 * Create a network-namespaced proc file in the @parent directory with the
 * specified @name and @mode that allows reading of a file that displays a
 * single element rather than a series and also provides for the file accepting
 * writes that have some arbitrary effect.
 *
 * The @show function is called to extract the readable content via the
 * seq_file interface.
 *
 * The @write function is called with the data copied into a kernel space
 * scratch buffer and has a NUL appended for convenience.  The buffer may be
 * modified by the @write function.  @write should return 0 on success.
 *
 * The @data value is accessible from the @show and @write functions by calling
 * PDE_DATA() on the file inode.  The network namespace must be accessed by
 * calling seq_file_single_net() on the seq_file struct.
 */
struct proc_dir_entry *proc_create_net_single_write(const char *name, umode_t mode,
						    struct proc_dir_entry *parent,
						    int (*show)(struct seq_file *, void *),
						    proc_write_t write,
						    void *data)
{
	struct proc_dir_entry *p;

	p = proc_create_reg(name, mode, &parent, data);
	if (!p)
		return NULL;
	pde_force_lookup(p);
	p->proc_fops = &proc_net_single_fops;
	p->single_show = show;
	p->write = write;
	return proc_register(parent, p);
}
EXPORT_SYMBOL_GPL(proc_create_net_single_write);

static struct net *get_proc_task_net(struct inode *dir)
{
	struct task_struct *task;
	struct nsproxy *ns;
	struct net *net = NULL;

	rcu_read_lock();
	task = pid_task(proc_pid(dir), PIDTYPE_PID);
	if (task != NULL) {
		task_lock(task);
		ns = task->nsproxy;
		if (ns != NULL)
			net = get_net(ns->net_ns);
		task_unlock(task);
	}
	rcu_read_unlock();

	return net;
}

static struct dentry *proc_tgid_net_lookup(struct inode *dir,
		struct dentry *dentry, unsigned int flags)
{
	struct dentry *de;
	struct net *net;

	de = ERR_PTR(-ENOENT);
	net = get_proc_task_net(dir);
	if (net != NULL) {
		de = proc_lookup_de(dir, dentry, net->proc_net);
		put_net(net);
	}
	return de;
}

static int proc_tgid_net_getattr(const struct path *path, struct kstat *stat,
				 u32 request_mask, unsigned int query_flags)
{
	struct inode *inode = d_inode(path->dentry);
	struct net *net;

	net = get_proc_task_net(inode);

	generic_fillattr(inode, stat);

	if (net != NULL) {
		stat->nlink = net->proc_net->nlink;
		put_net(net);
	}

	return 0;
}

const struct inode_operations proc_net_inode_operations = {
	.lookup		= proc_tgid_net_lookup,
	.getattr	= proc_tgid_net_getattr,
};

static int proc_tgid_net_readdir(struct file *file, struct dir_context *ctx)
{
	int ret;
	struct net *net;

	ret = -EINVAL;
	net = get_proc_task_net(file_inode(file));
	if (net != NULL) {
		ret = proc_readdir_de(file, ctx, net->proc_net);
		put_net(net);
	}
	return ret;
}

const struct file_operations proc_net_operations = {
	.llseek		= generic_file_llseek,
	.read		= generic_read_dir,
	.iterate_shared	= proc_tgid_net_readdir,
};

static __net_init int proc_net_ns_init(struct net *net)
{
	struct proc_dir_entry *netd, *net_statd;
	kuid_t uid;
	kgid_t gid;
	int err;

	err = -ENOMEM;
	netd = kmem_cache_zalloc(proc_dir_entry_cache, GFP_KERNEL);
	if (!netd)
		goto out;

	netd->subdir = RB_ROOT;
	netd->data = net;
	netd->nlink = 2;
	netd->namelen = 3;
	netd->parent = &proc_root;
	netd->name = netd->inline_name;
	memcpy(netd->name, "net", 4);

	uid = make_kuid(net->user_ns, 0);
	if (!uid_valid(uid))
		uid = netd->uid;

	gid = make_kgid(net->user_ns, 0);
	if (!gid_valid(gid))
		gid = netd->gid;

	proc_set_user(netd, uid, gid);

	err = -EEXIST;
	net_statd = proc_net_mkdir(net, "stat", netd);
	if (!net_statd)
		goto free_net;

	net->proc_net = netd;
	net->proc_net_stat = net_statd;
	return 0;

free_net:
	pde_free(netd);
out:
	return err;
}

static __net_exit void proc_net_ns_exit(struct net *net)
{
	remove_proc_entry("stat", net->proc_net);
	pde_free(net->proc_net);
}

static struct pernet_operations __net_initdata proc_net_ns_ops = {
	.init = proc_net_ns_init,
	.exit = proc_net_ns_exit,
};

int __init proc_net_init(void)
{
	proc_symlink("net", NULL, "self/net");

	return register_pernet_subsys(&proc_net_ns_ops);
}
Commit	Line	Data
3c12afe7 DM	1	/*
	2	* linux/fs/proc/net.c
	3	*
	4	* Copyright (C) 2007
	5	*
	6	* Author: Eric Biederman <[email protected]>
	7	*
	8	* proc net directory handling functions
	9	*/
	10
7c0f6ba6	11	#include <linux/uaccess.h>
3c12afe7 DM	12
	13	#include <linux/errno.h>
	14	#include <linux/time.h>
	15	#include <linux/proc_fs.h>
	16	#include <linux/stat.h>
5a0e3ad6	17	#include <linux/slab.h>
3c12afe7 DM	18	#include <linux/init.h>
3c12afe7 DM	19	#include <linux/sched.h>
f719ff9b	20	#include <linux/sched/task.h>
3c12afe7 DM	21	#include <linux/module.h>
3c12afe7 DM	22	#include <linux/bitops.h>
3c12afe7 DM	23	#include <linux/mount.h>
3c12afe7 DM	24	#include <linux/nsproxy.h>
c110486f	25	#include <linux/uidgid.h>
3c12afe7	26	#include <net/net_namespace.h>
e372c414	27	#include <linux/seq_file.h>
3c12afe7 DM	28
	29	#include "internal.h"
	30
4abfd029 DH	31	static inline struct net PDE_NET(struct proc_dir_entry pde)
	32	{
	33	return pde->parent->data;
	34	}
3c12afe7	35
8086cd45 AB	36	static struct net get_proc_net(const struct inode inode)
	37	{
	38	return maybe_get_net(PDE_NET(PDE(inode)));
	39	}
	40
1fde6f21 AD	41	static int proc_net_d_revalidate(struct dentry *dentry, unsigned int flags)
	42	{
	43	return 0;
	44	}
	45
	46	static const struct dentry_operations proc_net_dentry_ops = {
	47	.d_revalidate = proc_net_d_revalidate,
	48	.d_delete = always_delete_dentry,
	49	};
	50
	51	static void pde_force_lookup(struct proc_dir_entry *pde)
	52	{
	53	/* /proc/net/ entries can be changed under us by setns(CLONE_NEWNET) */
	54	pde->proc_dops = &proc_net_dentry_ops;
	55	}
	56
c3506372	57	static int seq_open_net(struct inode inode, struct file file)
e372c414	58	{
c3506372	59	unsigned int state_size = PDE(inode)->state_size;
e372c414	60	struct seq_net_private *p;
c3506372	61	struct net *net;
e372c414	62
c3506372	63	WARN_ON_ONCE(state_size < sizeof(*p));
e372c414	64
564def71 DH	65	if (file->f_mode & FMODE_WRITE && !PDE(inode)->write)
	66	return -EACCES;
	67
c3506372 CH	68	net = get_proc_net(inode);
c3506372 CH	69	if (!net)
e372c414 DL	70	return -ENXIO;
e372c414 DL	71
c3506372 CH	72	p = __seq_open_private(file, PDE(inode)->seq_ops, state_size);
c3506372 CH	73	if (!p) {
e372c414 DL	74	put_net(net);
	75	return -ENOMEM;
	76	}
1218854a	77	#ifdef CONFIG_NET_NS
e372c414	78	p->net = net;
1218854a	79	#endif
e372c414 DL	80	return 0;
e372c414 DL	81	}
c3506372 CH	82
	83	static int seq_release_net(struct inode ino, struct file f)
	84	{
	85	struct seq_file *seq = f->private_data;
	86
	87	put_net(seq_file_net(seq));
	88	seq_release_private(ino, f);
	89	return 0;
	90	}
	91
	92	static const struct file_operations proc_net_seq_fops = {
	93	.open = seq_open_net,
	94	.read = seq_read,
564def71	95	.write = proc_simple_write,
c3506372 CH	96	.llseek = seq_lseek,
	97	.release = seq_release_net,
	98	};
	99
	100	struct proc_dir_entry proc_create_net_data(const char name, umode_t mode,
	101	struct proc_dir_entry parent, const struct seq_operations ops,
	102	unsigned int state_size, void *data)
	103	{
	104	struct proc_dir_entry *p;
	105
	106	p = proc_create_reg(name, mode, &parent, data);
	107	if (!p)
	108	return NULL;
1fde6f21	109	pde_force_lookup(p);
c3506372 CH	110	p->proc_fops = &proc_net_seq_fops;
	111	p->seq_ops = ops;
	112	p->state_size = state_size;
	113	return proc_register(parent, p);
	114	}
	115	EXPORT_SYMBOL_GPL(proc_create_net_data);
e372c414	116
564def71 DH	117	/**
	118	* proc_create_net_data_write - Create a writable net_ns-specific proc file
	119	* @name: The name of the file.
	120	* @mode: The file's access mode.
	121	* @parent: The parent directory in which to create.
	122	* @ops: The seq_file ops with which to read the file.
	123	* @write: The write method which which to 'modify' the file.
	124	* @data: Data for retrieval by PDE_DATA().
	125	*
	126	* Create a network namespaced proc file in the @parent directory with the
	127	* specified @name and @mode that allows reading of a file that displays a
	128	* series of elements and also provides for the file accepting writes that have
	129	* some arbitrary effect.
	130	*
	131	* The functions in the @ops table are used to iterate over items to be
	132	* presented and extract the readable content using the seq_file interface.
	133	*
	134	* The @write function is called with the data copied into a kernel space
	135	* scratch buffer and has a NUL appended for convenience. The buffer may be
	136	* modified by the @write function. @write should return 0 on success.
	137	*
	138	* The @data value is accessible from the @show and @write functions by calling
	139	* PDE_DATA() on the file inode. The network namespace must be accessed by
	140	* calling seq_file_net() on the seq_file struct.
	141	*/
	142	struct proc_dir_entry proc_create_net_data_write(const char name, umode_t mode,
	143	struct proc_dir_entry *parent,
	144	const struct seq_operations *ops,
	145	proc_write_t write,
	146	unsigned int state_size, void *data)
	147	{
	148	struct proc_dir_entry *p;
	149
	150	p = proc_create_reg(name, mode, &parent, data);
	151	if (!p)
	152	return NULL;
1fde6f21	153	pde_force_lookup(p);
564def71 DH	154	p->proc_fops = &proc_net_seq_fops;
	155	p->seq_ops = ops;
	156	p->state_size = state_size;
	157	p->write = write;
	158	return proc_register(parent, p);
	159	}
	160	EXPORT_SYMBOL_GPL(proc_create_net_data_write);
	161
3617d949	162	static int single_open_net(struct inode inode, struct file file)
de05c557	163	{
3617d949	164	struct proc_dir_entry *de = PDE(inode);
de05c557	165	struct net *net;
3617d949	166	int err;
de05c557	167
de05c557	168	net = get_proc_net(inode);
3617d949 CH	169	if (!net)
3617d949 CH	170	return -ENXIO;
de05c557	171
3617d949 CH	172	err = single_open(file, de->single_show, net);
	173	if (err)
	174	put_net(net);
de05c557 PE	175	return err;
de05c557 PE	176	}
de05c557	177
3617d949	178	static int single_release_net(struct inode ino, struct file f)
b6fcbdb4 PE	179	{
	180	struct seq_file *seq = f->private_data;
	181	put_net(seq->private);
	182	return single_release(ino, f);
	183	}
3617d949 CH	184
	185	static const struct file_operations proc_net_single_fops = {
	186	.open = single_open_net,
	187	.read = seq_read,
564def71	188	.write = proc_simple_write,
3617d949 CH	189	.llseek = seq_lseek,
	190	.release = single_release_net,
	191	};
	192
	193	struct proc_dir_entry proc_create_net_single(const char name, umode_t mode,
	194	struct proc_dir_entry *parent,
	195	int (show)(struct seq_file , void ), void data)
	196	{
	197	struct proc_dir_entry *p;
	198
	199	p = proc_create_reg(name, mode, &parent, data);
	200	if (!p)
	201	return NULL;
1fde6f21	202	pde_force_lookup(p);
3617d949 CH	203	p->proc_fops = &proc_net_single_fops;
	204	p->single_show = show;
	205	return proc_register(parent, p);
	206	}
	207	EXPORT_SYMBOL_GPL(proc_create_net_single);
b6fcbdb4	208
564def71 DH	209	/**
	210	* proc_create_net_single_write - Create a writable net_ns-specific proc file
	211	* @name: The name of the file.
	212	* @mode: The file's access mode.
	213	* @parent: The parent directory in which to create.
	214	* @show: The seqfile show method with which to read the file.
	215	* @write: The write method which which to 'modify' the file.
	216	* @data: Data for retrieval by PDE_DATA().
	217	*
	218	* Create a network-namespaced proc file in the @parent directory with the
	219	* specified @name and @mode that allows reading of a file that displays a
	220	* single element rather than a series and also provides for the file accepting
	221	* writes that have some arbitrary effect.
	222	*
	223	* The @show function is called to extract the readable content via the
	224	* seq_file interface.
	225	*
	226	* The @write function is called with the data copied into a kernel space
	227	* scratch buffer and has a NUL appended for convenience. The buffer may be
	228	* modified by the @write function. @write should return 0 on success.
	229	*
	230	* The @data value is accessible from the @show and @write functions by calling
	231	* PDE_DATA() on the file inode. The network namespace must be accessed by
	232	* calling seq_file_single_net() on the seq_file struct.
	233	*/
	234	struct proc_dir_entry proc_create_net_single_write(const char name, umode_t mode,
	235	struct proc_dir_entry *parent,
	236	int (show)(struct seq_file , void *),
	237	proc_write_t write,
	238	void *data)
	239	{
	240	struct proc_dir_entry *p;
	241
	242	p = proc_create_reg(name, mode, &parent, data);
	243	if (!p)
	244	return NULL;
1fde6f21	245	pde_force_lookup(p);
564def71 DH	246	p->proc_fops = &proc_net_single_fops;
	247	p->single_show = show;
	248	p->write = write;
	249	return proc_register(parent, p);
	250	}
	251	EXPORT_SYMBOL_GPL(proc_create_net_single_write);
	252
e9720acd PE	253	static struct net get_proc_task_net(struct inode dir)
	254	{
	255	struct task_struct *task;
	256	struct nsproxy *ns;
	257	struct net *net = NULL;
	258
	259	rcu_read_lock();
	260	task = pid_task(proc_pid(dir), PIDTYPE_PID);
	261	if (task != NULL) {
728dba3a EB	262	task_lock(task);
728dba3a EB	263	ns = task->nsproxy;
e9720acd PE	264	if (ns != NULL)
e9720acd PE	265	net = get_net(ns->net_ns);
728dba3a	266	task_unlock(task);
e9720acd PE	267	}
	268	rcu_read_unlock();
	269
	270	return net;
	271	}
	272
	273	static struct dentry proc_tgid_net_lookup(struct inode dir,
00cd8dd3	274	struct dentry *dentry, unsigned int flags)
e9720acd PE	275	{
	276	struct dentry *de;
	277	struct net *net;
	278
	279	de = ERR_PTR(-ENOENT);
	280	net = get_proc_task_net(dir);
	281	if (net != NULL) {
93ad5bc6	282	de = proc_lookup_de(dir, dentry, net->proc_net);
e9720acd PE	283	put_net(net);
	284	}
	285	return de;
	286	}
	287
a528d35e DH	288	static int proc_tgid_net_getattr(const struct path path, struct kstat stat,
a528d35e DH	289	u32 request_mask, unsigned int query_flags)
e9720acd	290	{
a528d35e	291	struct inode *inode = d_inode(path->dentry);
e9720acd PE	292	struct net *net;
	293
	294	net = get_proc_task_net(inode);
	295
	296	generic_fillattr(inode, stat);
	297
	298	if (net != NULL) {
	299	stat->nlink = net->proc_net->nlink;
	300	put_net(net);
	301	}
	302
	303	return 0;
	304	}
	305
	306	const struct inode_operations proc_net_inode_operations = {
	307	.lookup = proc_tgid_net_lookup,
	308	.getattr = proc_tgid_net_getattr,
	309	};
	310
f0c3b509	311	static int proc_tgid_net_readdir(struct file file, struct dir_context ctx)
e9720acd PE	312	{
	313	int ret;
	314	struct net *net;
	315
	316	ret = -EINVAL;
f0c3b509	317	net = get_proc_task_net(file_inode(file));
e9720acd	318	if (net != NULL) {
93ad5bc6	319	ret = proc_readdir_de(file, ctx, net->proc_net);
e9720acd PE	320	put_net(net);
	321	}
	322	return ret;
	323	}
	324
	325	const struct file_operations proc_net_operations = {
b4df2b92	326	.llseek = generic_file_llseek,
e9720acd	327	.read = generic_read_dir,
f50752ea	328	.iterate_shared = proc_tgid_net_readdir,
e9720acd PE	329	};
e9720acd PE	330
4665079c	331	static __net_init int proc_net_ns_init(struct net *net)
3c12afe7	332	{
e9720acd	333	struct proc_dir_entry netd, net_statd;
c110486f DT	334	kuid_t uid;
c110486f DT	335	kgid_t gid;
3c12afe7 DM	336	int err;
	337
	338	err = -ENOMEM;
b4884f23	339	netd = kmem_cache_zalloc(proc_dir_entry_cache, GFP_KERNEL);
e9720acd	340	if (!netd)
3c12afe7 DM	341	goto out;
3c12afe7 DM	342
4f113437	343	netd->subdir = RB_ROOT;
e9720acd PE	344	netd->data = net;
e9720acd PE	345	netd->nlink = 2;
e9720acd PE	346	netd->namelen = 3;
e9720acd PE	347	netd->parent = &proc_root;
b4884f23	348	netd->name = netd->inline_name;
09570f91	349	memcpy(netd->name, "net", 4);
3c12afe7	350
c110486f DT	351	uid = make_kuid(net->user_ns, 0);
	352	if (!uid_valid(uid))
	353	uid = netd->uid;
	354
	355	gid = make_kgid(net->user_ns, 0);
	356	if (!gid_valid(gid))
	357	gid = netd->gid;
	358
	359	proc_set_user(netd, uid, gid);
	360
3c12afe7	361	err = -EEXIST;
e5d69b9f	362	net_statd = proc_net_mkdir(net, "stat", netd);
3c12afe7 DM	363	if (!net_statd)
	364	goto free_net;
	365
3c12afe7 DM	366	net->proc_net = netd;
3c12afe7 DM	367	net->proc_net_stat = net_statd;
e9720acd	368	return 0;
3c12afe7	369
e9720acd	370	free_net:
b4884f23	371	pde_free(netd);
3c12afe7 DM	372	out:
3c12afe7 DM	373	return err;
3c12afe7 DM	374	}
3c12afe7 DM	375
4665079c	376	static __net_exit void proc_net_ns_exit(struct net *net)
3c12afe7 DM	377	{
3c12afe7 DM	378	remove_proc_entry("stat", net->proc_net);
b4884f23	379	pde_free(net->proc_net);
3c12afe7 DM	380	}
3c12afe7 DM	381
022cbae6	382	static struct pernet_operations __net_initdata proc_net_ns_ops = {
3c12afe7 DM	383	.init = proc_net_ns_init,
	384	.exit = proc_net_ns_exit,
	385	};
	386
4665079c	387	int __init proc_net_init(void)
3c12afe7	388	{
155134fe	389	proc_symlink("net", NULL, "self/net");
3c12afe7 DM	390
	391	return register_pernet_subsys(&proc_net_ns_ops);
	392	}