fs/proc/proc_net.c

   1 /*
   2  *  linux/fs/proc/net.c
   3  *
   4  *  Copyright (C) 2007
   5  *
   6  *  Author: Eric Biederman <ebiederm@xmission.com>
   7  *
   8  *  proc net directory handling functions
   9  */
  10
  11 #include <asm/uaccess.h>
  12
  13 #include <linux/errno.h>
  14 #include <linux/time.h>
  15 #include <linux/proc_fs.h>
  16 #include <linux/stat.h>
  17 #include <linux/init.h>
  18 #include <linux/sched.h>
  19 #include <linux/module.h>
  20 #include <linux/bitops.h>
  21 #include <linux/smp_lock.h>
  22 #include <linux/mount.h>
  23 #include <linux/nsproxy.h>
  24 #include <net/net_namespace.h>
  25
  26 #include "internal.h"
  27
  28
  29 struct proc_dir_entry *proc_net_fops_create(struct net *net,
  30         const char *name, mode_t mode, const struct file_operations *fops)
  31 {
  32         struct proc_dir_entry *res;
  33
  34         res = create_proc_entry(name, mode, net->proc_net);
  35         if (res)
  36                 res->proc_fops = fops;
  37         return res;
  38 }
  39 EXPORT_SYMBOL_GPL(proc_net_fops_create);
  40
  41 void proc_net_remove(struct net *net, const char *name)
  42 {
  43         remove_proc_entry(name, net->proc_net);
  44 }
  45 EXPORT_SYMBOL_GPL(proc_net_remove);
  46
  47 struct net *get_proc_net(const struct inode *inode)
  48 {
  49         return maybe_get_net(PDE_NET(PDE(inode)));
  50 }
  51 EXPORT_SYMBOL_GPL(get_proc_net);
  52
  53 static struct proc_dir_entry *shadow_pde;
  54
  55 static struct proc_dir_entry *proc_net_shadow(struct task_struct *task,
  56                                                 struct proc_dir_entry *de)
  57 {
  58         return task->nsproxy->net_ns->proc_net;
  59 }
  60
  61 static __net_init int proc_net_ns_init(struct net *net)
  62 {
  63         struct proc_dir_entry *root, *netd, *net_statd;
  64         int err;
  65
  66         err = -ENOMEM;
  67         root = kzalloc(sizeof(*root), GFP_KERNEL);
  68         if (!root)
  69                 goto out;
  70
  71         err = -EEXIST;
  72         netd = proc_mkdir("net", root);
  73         if (!netd)
  74                 goto free_root;
  75
  76         err = -EEXIST;
  77         net_statd = proc_mkdir("stat", netd);
  78         if (!net_statd)
  79                 goto free_net;
  80
  81         root->data = net;
  82         netd->data = net;
  83         net_statd->data = net;
  84
  85         net->proc_net_root = root;
  86         net->proc_net = netd;
  87         net->proc_net_stat = net_statd;
  88         err = 0;
  89
  90 out:
  91         return err;
  92 free_net:
  93         remove_proc_entry("net", root);
  94 free_root:
  95         kfree(root);
  96         goto out;
  97 }
  98
  99 static __net_exit void proc_net_ns_exit(struct net *net)
 100 {
 101         remove_proc_entry("stat", net->proc_net);
 102         remove_proc_entry("net", net->proc_net_root);
 103         kfree(net->proc_net_root);
 104 }
 105
 106 static struct pernet_operations __net_initdata proc_net_ns_ops = {
 107         .init = proc_net_ns_init,
 108         .exit = proc_net_ns_exit,
 109 };
 110
 111 int __init proc_net_init(void)
 112 {
 113         shadow_pde = proc_mkdir("net", NULL);
 114         shadow_pde->shadow_proc = proc_net_shadow;
 115
 116         return register_pernet_subsys(&proc_net_ns_ops);
 117 }