mirror of
https://github.com/torvalds/linux.git
synced 2024-12-28 22:02:28 +00:00
2b1e300a9d
Well I clearly goofed when I added the initial network namespace support for /proc/net. Currently things work but there are odd details visible to user space, even when we have a single network namespace. Since we do not cache proc_dir_entry dentries at the moment we can just modify ->lookup to return a different directory inode depending on the network namespace of the process looking at /proc/net, replacing the current technique of using a magic and fragile follow_link method. To accomplish that this patch: - introduces a shadow_proc method to allow different dentries to be returned from proc_lookup. - Removes the old /proc/net follow_link magic - Fixes a weakness in our not caching of proc generic dentries. As shadow_proc uses a task struct to decided which dentry to return we can go back later and fix the proc generic caching without modifying any code that uses the shadow_proc method. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Pavel Machek <pavel@ucw.cz> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
118 lines
2.3 KiB
C
118 lines
2.3 KiB
C
/*
|
|
* 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 *shadow_pde;
|
|
|
|
static struct proc_dir_entry *proc_net_shadow(struct task_struct *task,
|
|
struct proc_dir_entry *de)
|
|
{
|
|
return task->nsproxy->net_ns->proc_net;
|
|
}
|
|
|
|
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 __net_initdata proc_net_ns_ops = {
|
|
.init = proc_net_ns_init,
|
|
.exit = proc_net_ns_exit,
|
|
};
|
|
|
|
int __init proc_net_init(void)
|
|
{
|
|
shadow_pde = proc_mkdir("net", NULL);
|
|
shadow_pde->shadow_proc = proc_net_shadow;
|
|
|
|
return register_pernet_subsys(&proc_net_ns_ops);
|
|
}
|