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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 task_lock(task);
117 ns = task->nsproxy;
118 if (ns != NULL)
119 net = get_net(ns->net_ns);
120 task_unlock(task);
121 }
122 rcu_read_unlock();
123
124 return net;
125}
126
127static struct dentry *proc_tgid_net_lookup(struct inode *dir,
128 struct dentry *dentry, unsigned int flags)
129{
130 struct dentry *de;
131 struct net *net;
132
133 de = ERR_PTR(-ENOENT);
134 net = get_proc_task_net(dir);
135 if (net != NULL) {
136 de = proc_lookup_de(net->proc_net, dir, dentry);
137 put_net(net);
138 }
139 return de;
140}
141
142static int proc_tgid_net_getattr(struct vfsmount *mnt, struct dentry *dentry,
143 struct kstat *stat)
144{
145 struct inode *inode = dentry->d_inode;
146 struct net *net;
147
148 net = get_proc_task_net(inode);
149
150 generic_fillattr(inode, stat);
151
152 if (net != NULL) {
153 stat->nlink = net->proc_net->nlink;
154 put_net(net);
155 }
156
157 return 0;
158}
159
160const struct inode_operations proc_net_inode_operations = {
161 .lookup = proc_tgid_net_lookup,
162 .getattr = proc_tgid_net_getattr,
163};
164
165static int proc_tgid_net_readdir(struct file *file, struct dir_context *ctx)
166{
167 int ret;
168 struct net *net;
169
170 ret = -EINVAL;
171 net = get_proc_task_net(file_inode(file));
172 if (net != NULL) {
173 ret = proc_readdir_de(net->proc_net, file, ctx);
174 put_net(net);
175 }
176 return ret;
177}
178
179const struct file_operations proc_net_operations = {
180 .llseek = generic_file_llseek,
181 .read = generic_read_dir,
182 .iterate = proc_tgid_net_readdir,
183};
184
185static __net_init int proc_net_ns_init(struct net *net)
186{
187 struct proc_dir_entry *netd, *net_statd;
188 int err;
189
190 err = -ENOMEM;
191 netd = kzalloc(sizeof(*netd) + 4, GFP_KERNEL);
192 if (!netd)
193 goto out;
194
195 netd->data = net;
196 netd->nlink = 2;
197 netd->namelen = 3;
198 netd->parent = &proc_root;
199 memcpy(netd->name, "net", 4);
200
201 err = -EEXIST;
202 net_statd = proc_net_mkdir(net, "stat", netd);
203 if (!net_statd)
204 goto free_net;
205
206 net->proc_net = netd;
207 net->proc_net_stat = net_statd;
208 return 0;
209
210free_net:
211 kfree(netd);
212out:
213 return err;
214}
215
216static __net_exit void proc_net_ns_exit(struct net *net)
217{
218 remove_proc_entry("stat", net->proc_net);
219 kfree(net->proc_net);
220}
221
222static struct pernet_operations __net_initdata proc_net_ns_ops = {
223 .init = proc_net_ns_init,
224 .exit = proc_net_ns_exit,
225};
226
227int __init proc_net_init(void)
228{
229 proc_symlink("net", NULL, "self/net");
230
231 return register_pernet_subsys(&proc_net_ns_ops);
232}
233
