Linux kernel mirror (for testing)
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linux
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/slab.h>
18#include <linux/init.h>
19#include <linux/sched.h>
20#include <linux/module.h>
21#include <linux/bitops.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
29static inline struct net *PDE_NET(struct proc_dir_entry *pde)
30{
31 return pde->parent->data;
32}
33
34static struct net *get_proc_net(const struct inode *inode)
35{
36 return maybe_get_net(PDE_NET(PDE(inode)));
37}
38
39int seq_open_net(struct inode *ino, struct file *f,
40 const struct seq_operations *ops, int size)
41{
42 struct net *net;
43 struct seq_net_private *p;
44
45 BUG_ON(size < sizeof(*p));
46
47 net = get_proc_net(ino);
48 if (net == NULL)
49 return -ENXIO;
50
51 p = __seq_open_private(f, ops, size);
52 if (p == NULL) {
53 put_net(net);
54 return -ENOMEM;
55 }
56#ifdef CONFIG_NET_NS
57 p->net = net;
58#endif
59 return 0;
60}
61EXPORT_SYMBOL_GPL(seq_open_net);
62
63int single_open_net(struct inode *inode, struct file *file,
64 int (*show)(struct seq_file *, void *))
65{
66 int err;
67 struct net *net;
68
69 err = -ENXIO;
70 net = get_proc_net(inode);
71 if (net == NULL)
72 goto err_net;
73
74 err = single_open(file, show, net);
75 if (err < 0)
76 goto err_open;
77
78 return 0;
79
80err_open:
81 put_net(net);
82err_net:
83 return err;
84}
85EXPORT_SYMBOL_GPL(single_open_net);
86
87int seq_release_net(struct inode *ino, struct file *f)
88{
89 struct seq_file *seq;
90
91 seq = f->private_data;
92
93 put_net(seq_file_net(seq));
94 seq_release_private(ino, f);
95 return 0;
96}
97EXPORT_SYMBOL_GPL(seq_release_net);
98
99int single_release_net(struct inode *ino, struct file *f)
100{
101 struct seq_file *seq = f->private_data;
102 put_net(seq->private);
103 return single_release(ino, f);
104}
105EXPORT_SYMBOL_GPL(single_release_net);
106
107static struct net *get_proc_task_net(struct inode *dir)
108{
109 struct task_struct *task;
110 struct nsproxy *ns;
111 struct net *net = NULL;
112
113 rcu_read_lock();
114 task = pid_task(proc_pid(dir), PIDTYPE_PID);
115 if (task != NULL) {
116 ns = task_nsproxy(task);
117 if (ns != NULL)
118 net = get_net(ns->net_ns);
119 }
120 rcu_read_unlock();
121
122 return net;
123}
124
125static struct dentry *proc_tgid_net_lookup(struct inode *dir,
126 struct dentry *dentry, unsigned int flags)
127{
128 struct dentry *de;
129 struct net *net;
130
131 de = ERR_PTR(-ENOENT);
132 net = get_proc_task_net(dir);
133 if (net != NULL) {
134 de = proc_lookup_de(net->proc_net, dir, dentry);
135 put_net(net);
136 }
137 return de;
138}
139
140static int proc_tgid_net_getattr(struct vfsmount *mnt, struct dentry *dentry,
141 struct kstat *stat)
142{
143 struct inode *inode = dentry->d_inode;
144 struct net *net;
145
146 net = get_proc_task_net(inode);
147
148 generic_fillattr(inode, stat);
149
150 if (net != NULL) {
151 stat->nlink = net->proc_net->nlink;
152 put_net(net);
153 }
154
155 return 0;
156}
157
158const struct inode_operations proc_net_inode_operations = {
159 .lookup = proc_tgid_net_lookup,
160 .getattr = proc_tgid_net_getattr,
161};
162
163static int proc_tgid_net_readdir(struct file *file, struct dir_context *ctx)
164{
165 int ret;
166 struct net *net;
167
168 ret = -EINVAL;
169 net = get_proc_task_net(file_inode(file));
170 if (net != NULL) {
171 ret = proc_readdir_de(net->proc_net, file, ctx);
172 put_net(net);
173 }
174 return ret;
175}
176
177const struct file_operations proc_net_operations = {
178 .llseek = generic_file_llseek,
179 .read = generic_read_dir,
180 .iterate = proc_tgid_net_readdir,
181};
182
183static __net_init int proc_net_ns_init(struct net *net)
184{
185 struct proc_dir_entry *netd, *net_statd;
186 int err;
187
188 err = -ENOMEM;
189 netd = kzalloc(sizeof(*netd) + 4, GFP_KERNEL);
190 if (!netd)
191 goto out;
192
193 netd->data = net;
194 netd->nlink = 2;
195 netd->namelen = 3;
196 netd->parent = &proc_root;
197 memcpy(netd->name, "net", 4);
198
199 err = -EEXIST;
200 net_statd = proc_net_mkdir(net, "stat", netd);
201 if (!net_statd)
202 goto free_net;
203
204 net->proc_net = netd;
205 net->proc_net_stat = net_statd;
206 return 0;
207
208free_net:
209 kfree(netd);
210out:
211 return err;
212}
213
214static __net_exit void proc_net_ns_exit(struct net *net)
215{
216 remove_proc_entry("stat", net->proc_net);
217 kfree(net->proc_net);
218}
219
220static struct pernet_operations __net_initdata proc_net_ns_ops = {
221 .init = proc_net_ns_init,
222 .exit = proc_net_ns_exit,
223};
224
225int __init proc_net_init(void)
226{
227 proc_symlink("net", NULL, "self/net");
228
229 return register_pernet_subsys(&proc_net_ns_ops);
230}