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 #include <linux/seq_file.h>
  26
  27 #include "internal.h"
  28
  29
  30 int seq_open_net(struct inode *ino, struct file *f,
  31                  const struct seq_operations *ops, int size)
  32 {
  33         struct net *net;
  34         struct seq_net_private *p;
  35
  36         BUG_ON(size < sizeof(*p));
  37
  38         net = get_proc_net(ino);
  39         if (net == NULL)
  40                 return -ENXIO;
  41
  42         p = __seq_open_private(f, ops, size);
  43         if (p == NULL) {
  44                 put_net(net);
  45                 return -ENOMEM;
  46         }
  47         p->net = net;
  48         return 0;
  49 }
  50 EXPORT_SYMBOL_GPL(seq_open_net);
  51
  52 int seq_release_net(struct inode *ino, struct file *f)
  53 {
  54         struct seq_file *seq;
  55         struct seq_net_private *p;
  56
  57         seq = f->private_data;
  58         p = seq->private;
  59
  60         put_net(p->net);
  61         seq_release_private(ino, f);
  62         return 0;
  63 }
  64 EXPORT_SYMBOL_GPL(seq_release_net);
  65
  66
  67 struct proc_dir_entry *proc_net_fops_create(struct net *net,
  68         const char *name, mode_t mode, const struct file_operations *fops)
  69 {
  70         return proc_create(name, mode, net->proc_net, fops);
  71 }
  72 EXPORT_SYMBOL_GPL(proc_net_fops_create);
  73
  74 void proc_net_remove(struct net *net, const char *name)
  75 {
  76         remove_proc_entry(name, net->proc_net);
  77 }
  78 EXPORT_SYMBOL_GPL(proc_net_remove);
  79
  80 struct net *get_proc_net(const struct inode *inode)
  81 {
  82         return maybe_get_net(PDE_NET(PDE(inode)));
  83 }
  84 EXPORT_SYMBOL_GPL(get_proc_net);
  85
  86 static struct proc_dir_entry *shadow_pde;
  87
  88 static struct proc_dir_entry *proc_net_shadow(struct task_struct *task,
  89                                                 struct proc_dir_entry *de)
  90 {
  91         return task->nsproxy->net_ns->proc_net;
  92 }
  93
  94 struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name,
  95                 struct proc_dir_entry *parent)
  96 {
  97         struct proc_dir_entry *pde;
  98         pde = proc_mkdir_mode(name, S_IRUGO | S_IXUGO, parent);
  99         if (pde != NULL)
 100                 pde->data = net;
 101         return pde;
 102 }
 103 EXPORT_SYMBOL_GPL(proc_net_mkdir);
 104
 105 static __net_init int proc_net_ns_init(struct net *net)
 106 {
 107         struct proc_dir_entry *root, *netd, *net_statd;
 108         int err;
 109
 110         err = -ENOMEM;
 111         root = kzalloc(sizeof(*root), GFP_KERNEL);
 112         if (!root)
 113                 goto out;
 114
 115         err = -EEXIST;
 116         netd = proc_net_mkdir(net, "net", root);
 117         if (!netd)
 118                 goto free_root;
 119
 120         err = -EEXIST;
 121         net_statd = proc_net_mkdir(net, "stat", netd);
 122         if (!net_statd)
 123                 goto free_net;
 124
 125         root->data = net;
 126
 127         net->proc_net_root = root;
 128         net->proc_net = netd;
 129         net->proc_net_stat = net_statd;
 130         err = 0;
 131
 132 out:
 133         return err;
 134 free_net:
 135         remove_proc_entry("net", root);
 136 free_root:
 137         kfree(root);
 138         goto out;
 139 }
 140
 141 static __net_exit void proc_net_ns_exit(struct net *net)
 142 {
 143         remove_proc_entry("stat", net->proc_net);
 144         remove_proc_entry("net", net->proc_net_root);
 145         kfree(net->proc_net_root);
 146 }
 147
 148 static struct pernet_operations __net_initdata proc_net_ns_ops = {
 149         .init = proc_net_ns_init,
 150         .exit = proc_net_ns_exit,
 151 };
 152
 153 int __init proc_net_init(void)
 154 {
 155         shadow_pde = proc_mkdir("net", NULL);
 156         shadow_pde->shadow_proc = proc_net_shadow;
 157
 158         return register_pernet_subsys(&proc_net_ns_ops);
 159 }