aboutsummaryrefslogtreecommitdiffstats
path: root/fs/proc/proc_net.c
blob: 7034facf8b8f553aa211324bbaf1da103f5dda9e (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
/*
 *  linux/fs/proc/net.c
 *
 *  Copyright (C) 2007
 *
 *  Author: Eric Biederman <ebiederm@xmission.com>
 *
 *  proc net directory handling functions
 */

#include <asm/uaccess.h>

#include <linux/errno.h>
#include <linux/time.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/smp_lock.h>
#include <linux/mount.h>
#include <linux/nsproxy.h>
#include <net/net_namespace.h>
#include <linux/seq_file.h>

#include "internal.h"


int seq_open_net(struct inode *ino, struct file *f,
		 const struct seq_operations *ops, int size)
{
	struct net *net;
	struct seq_net_private *p;

	BUG_ON(size < sizeof(*p));

	net = get_proc_net(ino);
	if (net == NULL)
		return -ENXIO;

	p = __seq_open_private(f, ops, size);
	if (p == NULL) {
		put_net(net);
		return -ENOMEM;
	}
#ifdef CONFIG_NET_NS
	p->net = net;
#endif
	return 0;
}
EXPORT_SYMBOL_GPL(seq_open_net);

#ifdef CONFIG_NET
int seq_release_net(struct inode *ino, struct file *f)
{
	struct seq_file *seq;

	seq = f->private_data;

	put_net(seq_file_net(seq));
	seq_release_private(ino, f);
	return 0;
}
EXPORT_SYMBOL_GPL(seq_release_net);

static struct net *get_proc_task_net(struct inode *dir)
{
	struct task_struct *task;
	struct nsproxy *ns;
	struct net *net = NULL;

	rcu_read_lock();
	task = pid_task(proc_pid(dir), PIDTYPE_PID);
	if (task != NULL) {
		ns = task_nsproxy(task);
		if (ns != NULL)
			net = get_net(ns->net_ns);
	}
	rcu_read_unlock();

	return net;
}

static struct dentry *proc_tgid_net_lookup(struct inode *dir,
		struct dentry *dentry, struct nameidata *nd)
{
	struct dentry *de;
	struct net *net;

	de = ERR_PTR(-ENOENT);
	net = get_proc_task_net(dir);
	if (net != NULL) {
		de = proc_lookup_de(net->proc_net, dir, dentry);
		put_net(net);
	}
	return de;
}

static int proc_tgid_net_getattr(struct vfsmount *mnt, struct dentry *dentry,
		struct kstat *stat)
{
	struct inode *inode = dentry->d_inode;
	struct net *net;

	net = get_proc_task_net(inode);

	generic_fillattr(inode, stat);

	if (net != NULL) {
		stat->nlink = net->proc_net->nlink;
		put_net(net);
	}

	return 0;
}

const struct inode_operations proc_net_inode_operations = {
	.lookup		= proc_tgid_net_lookup,
	.getattr	= proc_tgid_net_getattr,
};

static int proc_tgid_net_readdir(struct file *filp, void *dirent,
		filldir_t filldir)
{
	int ret;
	struct net *net;

	ret = -EINVAL;
	net = get_proc_task_net(filp->f_path.dentry->d_inode);
	if (net != NULL) {
		ret = proc_readdir_de(net->proc_net, filp, dirent, filldir);
		put_net(net);
	}
	return ret;
}

const struct file_operations proc_net_operations = {
	.read		= generic_read_dir,
	.readdir	= proc_tgid_net_readdir,
};


struct proc_dir_entry *proc_net_fops_create(struct net *net,
	const char *name, mode_t mode, const struct file_operations *fops)
{
	return proc_create(name, mode, net->proc_net, fops);
}
EXPORT_SYMBOL_GPL(proc_net_fops_create);

void proc_net_remove(struct net *net, const char *name)
{
	remove_proc_entry(name, net->proc_net);
}
EXPORT_SYMBOL_GPL(proc_net_remove);

struct net *get_proc_net(const struct inode *inode)
{
	return maybe_get_net(PDE_NET(PDE(inode)));
}
EXPORT_SYMBOL_GPL(get_proc_net);

struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name,
		struct proc_dir_entry *parent)
{
	struct proc_dir_entry *pde;
	pde = proc_mkdir_mode(name, S_IRUGO | S_IXUGO, parent);
	if (pde != NULL)
		pde->data = net;
	return pde;
}
EXPORT_SYMBOL_GPL(proc_net_mkdir);

static __net_init int proc_net_ns_init(struct net *net)
{
	struct proc_dir_entry *netd, *net_statd;
	int err;

	err = -ENOMEM;
	netd = kzalloc(sizeof(*netd), GFP_KERNEL);
	if (!netd)
		goto out;

	netd->data = net;
	netd->nlink = 2;
	netd->name = "net";
	netd->namelen = 3;
	netd->parent = &proc_root;

	err = -EEXIST;
	net_statd = proc_net_mkdir(net, "stat", netd);
	if (!net_statd)
		goto free_net;

	net->proc_net = netd;
	net->proc_net_stat = net_statd;
	return 0;

free_net:
	kfree(netd);
out:
	return err;
}

static __net_exit void proc_net_ns_exit(struct net *net)
{
	remove_proc_entry("stat", net->proc_net);
	kfree(net->proc_net);
}

static struct pernet_operations __net_initdata proc_net_ns_ops = {
	.init = proc_net_ns_init,
	.exit = proc_net_ns_exit,
};

int __init proc_net_init(void)
{
	proc_symlink("net", NULL, "self/net");

	return register_pernet_subsys(&proc_net_ns_ops);
}
#endif /* CONFIG_NET */