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
/*
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* linux/fs/proc/net.c
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*
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* Copyright (C) 2007
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*
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* Author: Eric Biederman <ebiederm@xmission.com>
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*
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* proc net directory handling functions
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*/
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#include <asm/uaccess.h>
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#include <linux/errno.h>
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#include <linux/time.h>
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#include <linux/proc_fs.h>
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#include <linux/stat.h>
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/module.h>
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#include <linux/bitops.h>
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#include <linux/smp_lock.h>
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#include <linux/mount.h>
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#include <linux/nsproxy.h>
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#include <net/net_namespace.h>
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#include "internal.h"
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struct proc_dir_entry *proc_net_fops_create(struct net *net,
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const char *name, mode_t mode, const struct file_operations *fops)
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{
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struct proc_dir_entry *res;
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res = create_proc_entry(name, mode, net->proc_net);
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if (res)
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res->proc_fops = fops;
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return res;
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}
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EXPORT_SYMBOL_GPL(proc_net_fops_create);
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void proc_net_remove(struct net *net, const char *name)
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{
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remove_proc_entry(name, net->proc_net);
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}
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EXPORT_SYMBOL_GPL(proc_net_remove);
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struct net *get_proc_net(const struct inode *inode)
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{
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return maybe_get_net(PDE_NET(PDE(inode)));
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}
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EXPORT_SYMBOL_GPL(get_proc_net);
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static struct proc_dir_entry *shadow_pde;
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static struct proc_dir_entry *proc_net_shadow(struct task_struct *task,
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struct proc_dir_entry *de)
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{
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return task->nsproxy->net_ns->proc_net;
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}
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static __net_init int proc_net_ns_init(struct net *net)
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{
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struct proc_dir_entry *root, *netd, *net_statd;
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int err;
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err = -ENOMEM;
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root = kzalloc(sizeof(*root), GFP_KERNEL);
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if (!root)
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goto out;
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err = -EEXIST;
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netd = proc_mkdir("net", root);
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if (!netd)
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goto free_root;
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err = -EEXIST;
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net_statd = proc_mkdir("stat", netd);
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if (!net_statd)
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goto free_net;
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root->data = net;
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netd->data = net;
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net_statd->data = net;
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net->proc_net_root = root;
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net->proc_net = netd;
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net->proc_net_stat = net_statd;
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err = 0;
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out:
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return err;
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free_net:
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remove_proc_entry("net", root);
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free_root:
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kfree(root);
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goto out;
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}
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static __net_exit void proc_net_ns_exit(struct net *net)
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{
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remove_proc_entry("stat", net->proc_net);
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remove_proc_entry("net", net->proc_net_root);
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kfree(net->proc_net_root);
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}
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static struct pernet_operations __net_initdata proc_net_ns_ops = {
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.init = proc_net_ns_init,
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.exit = proc_net_ns_exit,
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};
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int __init proc_net_init(void)
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{
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shadow_pde = proc_mkdir("net", NULL);
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shadow_pde->shadow_proc = proc_net_shadow;
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return register_pernet_subsys(&proc_net_ns_ops);
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}
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