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/fs/proc/proc_net.c

https://bitbucket.org/cyanogenmod/android_kernel_asus_tf300t
C | 241 lines | 187 code | 45 blank | 9 comment | 19 complexity | 124bbb3848dd9d4a87c426f0a7409e88 MD5 | raw file
Possible License(s): LGPL-2.0, AGPL-1.0, GPL-2.0
  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
 29
 30static struct net *get_proc_net(const struct inode *inode)
 31{
 32	return maybe_get_net(PDE_NET(PDE(inode)));
 33}
 34
 35int seq_open_net(struct inode *ino, struct file *f,
 36		 const struct seq_operations *ops, int size)
 37{
 38	struct net *net;
 39	struct seq_net_private *p;
 40
 41	BUG_ON(size < sizeof(*p));
 42
 43	net = get_proc_net(ino);
 44	if (net == NULL)
 45		return -ENXIO;
 46
 47	p = __seq_open_private(f, ops, size);
 48	if (p == NULL) {
 49		put_net(net);
 50		return -ENOMEM;
 51	}
 52#ifdef CONFIG_NET_NS
 53	p->net = net;
 54#endif
 55	return 0;
 56}
 57EXPORT_SYMBOL_GPL(seq_open_net);
 58
 59int single_open_net(struct inode *inode, struct file *file,
 60		int (*show)(struct seq_file *, void *))
 61{
 62	int err;
 63	struct net *net;
 64
 65	err = -ENXIO;
 66	net = get_proc_net(inode);
 67	if (net == NULL)
 68		goto err_net;
 69
 70	err = single_open(file, show, net);
 71	if (err < 0)
 72		goto err_open;
 73
 74	return 0;
 75
 76err_open:
 77	put_net(net);
 78err_net:
 79	return err;
 80}
 81EXPORT_SYMBOL_GPL(single_open_net);
 82
 83int seq_release_net(struct inode *ino, struct file *f)
 84{
 85	struct seq_file *seq;
 86
 87	seq = f->private_data;
 88
 89	put_net(seq_file_net(seq));
 90	seq_release_private(ino, f);
 91	return 0;
 92}
 93EXPORT_SYMBOL_GPL(seq_release_net);
 94
 95int single_release_net(struct inode *ino, struct file *f)
 96{
 97	struct seq_file *seq = f->private_data;
 98	put_net(seq->private);
 99	return single_release(ino, f);
100}
101EXPORT_SYMBOL_GPL(single_release_net);
102
103static struct net *get_proc_task_net(struct inode *dir)
104{
105	struct task_struct *task;
106	struct nsproxy *ns;
107	struct net *net = NULL;
108
109	rcu_read_lock();
110	task = pid_task(proc_pid(dir), PIDTYPE_PID);
111	if (task != NULL) {
112		ns = task_nsproxy(task);
113		if (ns != NULL)
114			net = get_net(ns->net_ns);
115	}
116	rcu_read_unlock();
117
118	return net;
119}
120
121static struct dentry *proc_tgid_net_lookup(struct inode *dir,
122		struct dentry *dentry, struct nameidata *nd)
123{
124	struct dentry *de;
125	struct net *net;
126
127	de = ERR_PTR(-ENOENT);
128	net = get_proc_task_net(dir);
129	if (net != NULL) {
130		de = proc_lookup_de(net->proc_net, dir, dentry);
131		put_net(net);
132	}
133	return de;
134}
135
136static int proc_tgid_net_getattr(struct vfsmount *mnt, struct dentry *dentry,
137		struct kstat *stat)
138{
139	struct inode *inode = dentry->d_inode;
140	struct net *net;
141
142	net = get_proc_task_net(inode);
143
144	generic_fillattr(inode, stat);
145
146	if (net != NULL) {
147		stat->nlink = net->proc_net->nlink;
148		put_net(net);
149	}
150
151	return 0;
152}
153
154const struct inode_operations proc_net_inode_operations = {
155	.lookup		= proc_tgid_net_lookup,
156	.getattr	= proc_tgid_net_getattr,
157};
158
159static int proc_tgid_net_readdir(struct file *filp, void *dirent,
160		filldir_t filldir)
161{
162	int ret;
163	struct net *net;
164
165	ret = -EINVAL;
166	net = get_proc_task_net(filp->f_path.dentry->d_inode);
167	if (net != NULL) {
168		ret = proc_readdir_de(net->proc_net, filp, dirent, filldir);
169		put_net(net);
170	}
171	return ret;
172}
173
174const struct file_operations proc_net_operations = {
175	.llseek		= generic_file_llseek,
176	.read		= generic_read_dir,
177	.readdir	= proc_tgid_net_readdir,
178};
179
180
181struct proc_dir_entry *proc_net_fops_create(struct net *net,
182	const char *name, mode_t mode, const struct file_operations *fops)
183{
184	return proc_create(name, mode, net->proc_net, fops);
185}
186EXPORT_SYMBOL_GPL(proc_net_fops_create);
187
188void proc_net_remove(struct net *net, const char *name)
189{
190	remove_proc_entry(name, net->proc_net);
191}
192EXPORT_SYMBOL_GPL(proc_net_remove);
193
194static __net_init int proc_net_ns_init(struct net *net)
195{
196	struct proc_dir_entry *netd, *net_statd;
197	int err;
198
199	err = -ENOMEM;
200	netd = kzalloc(sizeof(*netd) + 4, GFP_KERNEL);
201	if (!netd)
202		goto out;
203
204	netd->data = net;
205	netd->nlink = 2;
206	netd->namelen = 3;
207	netd->parent = &proc_root;
208	memcpy(netd->name, "net", 4);
209
210	err = -EEXIST;
211	net_statd = proc_net_mkdir(net, "stat", netd);
212	if (!net_statd)
213		goto free_net;
214
215	net->proc_net = netd;
216	net->proc_net_stat = net_statd;
217	return 0;
218
219free_net:
220	kfree(netd);
221out:
222	return err;
223}
224
225static __net_exit void proc_net_ns_exit(struct net *net)
226{
227	remove_proc_entry("stat", net->proc_net);
228	kfree(net->proc_net);
229}
230
231static struct pernet_operations __net_initdata proc_net_ns_ops = {
232	.init = proc_net_ns_init,
233	.exit = proc_net_ns_exit,
234};
235
236int __init proc_net_init(void)
237{
238	proc_symlink("net", NULL, "self/net");
239
240	return register_pernet_subsys(&proc_net_ns_ops);
241}