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/*
* linux/fs/proc/net.c
*
* Copyright (C) 2007
*
* Author: Eric Biederman <ebiederm@xmission.com>
*
* proc net directory handling functions
*/
#include <asm/uaccess.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/smp_lock.h>
#include <linux/mount.h>
#include <linux/nsproxy.h>
#include <net/net_namespace.h>
#include "internal.h"
struct proc_dir_entry *proc_net_fops_create(struct net *net,
const char *name, mode_t mode, const struct file_operations *fops)
{
struct proc_dir_entry *res;
res = create_proc_entry(name, mode, net->proc_net);
if (res)
res->proc_fops = fops;
return res;
}
EXPORT_SYMBOL_GPL(proc_net_fops_create);
void proc_net_remove(struct net *net, const char *name)
{
remove_proc_entry(name, net->proc_net);
}
EXPORT_SYMBOL_GPL(proc_net_remove);
struct net *get_proc_net(const struct inode *inode)
{
return maybe_get_net(PDE_NET(PDE(inode)));
}
EXPORT_SYMBOL_GPL(get_proc_net);
static struct proc_dir_entry *proc_net_shadow;
static struct dentry *proc_net_shadow_dentry(struct dentry *parent,
struct proc_dir_entry *de)
{
struct dentry *shadow = NULL;
struct inode *inode;
if (!de)
goto out;
de_get(de);
inode = proc_get_inode(parent->d_inode->i_sb, de->low_ino, de);
if (!inode)
goto out_de_put;
shadow = d_alloc_name(parent, de->name);
if (!shadow)
goto out_iput;
shadow->d_op = parent->d_op; /* proc_dentry_operations */
d_instantiate(shadow, inode);
out:
return shadow;
out_iput:
iput(inode);
out_de_put:
de_put(de);
goto out;
}
static void *proc_net_follow_link(struct dentry *parent, struct nameidata *nd)
{
struct net *net = current->nsproxy->net_ns;
struct dentry *shadow;
shadow = proc_net_shadow_dentry(parent, net->proc_net);
if (!shadow)
return ERR_PTR(-ENOENT);
dput(nd->dentry);
/* My dentry count is 1 and that should be enough as the
* shadow dentry is thrown away immediately.
*/
nd->dentry = shadow;
return NULL;
}
static struct dentry *proc_net_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
struct net *net = current->nsproxy->net_ns;
struct dentry *shadow;
shadow = proc_net_shadow_dentry(nd->dentry, net->proc_net);
if (!shadow)
return ERR_PTR(-ENOENT);
dput(nd->dentry);
nd->dentry = shadow;
return shadow->d_inode->i_op->lookup(shadow->d_inode, dentry, nd);
}
static int proc_net_setattr(struct dentry *dentry, struct iattr *iattr)
{
struct net *net = current->nsproxy->net_ns;
struct dentry *shadow;
int ret;
shadow = proc_net_shadow_dentry(dentry->d_parent, net->proc_net);
if (!shadow)
return -ENOENT;
ret = shadow->d_inode->i_op->setattr(shadow, iattr);
dput(shadow);
return ret;
}
static const struct file_operations proc_net_dir_operations = {
.read = generic_read_dir,
};
static struct inode_operations proc_net_dir_inode_operations = {
.follow_link = proc_net_follow_link,
.lookup = proc_net_lookup,
.setattr = proc_net_setattr,
};
static __net_init int proc_net_ns_init(struct net *net)
{
struct proc_dir_entry *root, *netd, *net_statd;
int err;
err = -ENOMEM;
root = kzalloc(sizeof(*root), GFP_KERNEL);
if (!root)
goto out;
err = -EEXIST;
netd = proc_mkdir("net", root);
if (!netd)
goto free_root;
err = -EEXIST;
net_statd = proc_mkdir("stat", netd);
if (!net_statd)
goto free_net;
root->data = net;
netd->data = net;
net_statd->data = net;
net->proc_net_root = root;
net->proc_net = netd;
net->proc_net_stat = net_statd;
err = 0;
out:
return err;
free_net:
remove_proc_entry("net", root);
free_root:
kfree(root);
goto out;
}
static __net_exit void proc_net_ns_exit(struct net *net)
{
remove_proc_entry("stat", net->proc_net);
remove_proc_entry("net", net->proc_net_root);
kfree(net->proc_net_root);
}
static struct pernet_operations proc_net_ns_ops = {
.init = proc_net_ns_init,
.exit = proc_net_ns_exit,
};
int __init proc_net_init(void)
{
proc_net_shadow = proc_mkdir("net", NULL);
proc_net_shadow->proc_iops = &proc_net_dir_inode_operations;
proc_net_shadow->proc_fops = &proc_net_dir_operations;
return register_pernet_subsys(&proc_net_ns_ops);
}
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