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/mount.h>
22 #include <linux/nsproxy.h>
23 #include <net/net_namespace.h>
24 #include <linux/seq_file.h>
25
26 #include "internal.h"
27
28
get_proc_net(const struct inode * inode)29 static struct net *get_proc_net(const struct inode *inode)
30 {
31 return maybe_get_net(PDE_NET(PDE(inode)));
32 }
33
seq_open_net(struct inode * ino,struct file * f,const struct seq_operations * ops,int size)34 int seq_open_net(struct inode *ino, struct file *f,
35 const struct seq_operations *ops, int size)
36 {
37 struct net *net;
38 struct seq_net_private *p;
39
40 BUG_ON(size < sizeof(*p));
41
42 net = get_proc_net(ino);
43 if (net == NULL)
44 return -ENXIO;
45
46 p = __seq_open_private(f, ops, size);
47 if (p == NULL) {
48 put_net(net);
49 return -ENOMEM;
50 }
51 #ifdef CONFIG_NET_NS
52 p->net = net;
53 #endif
54 return 0;
55 }
56 EXPORT_SYMBOL_GPL(seq_open_net);
57
single_open_net(struct inode * inode,struct file * file,int (* show)(struct seq_file *,void *))58 int single_open_net(struct inode *inode, struct file *file,
59 int (*show)(struct seq_file *, void *))
60 {
61 int err;
62 struct net *net;
63
64 err = -ENXIO;
65 net = get_proc_net(inode);
66 if (net == NULL)
67 goto err_net;
68
69 err = single_open(file, show, net);
70 if (err < 0)
71 goto err_open;
72
73 return 0;
74
75 err_open:
76 put_net(net);
77 err_net:
78 return err;
79 }
80 EXPORT_SYMBOL_GPL(single_open_net);
81
seq_release_net(struct inode * ino,struct file * f)82 int seq_release_net(struct inode *ino, struct file *f)
83 {
84 struct seq_file *seq;
85
86 seq = f->private_data;
87
88 put_net(seq_file_net(seq));
89 seq_release_private(ino, f);
90 return 0;
91 }
92 EXPORT_SYMBOL_GPL(seq_release_net);
93
single_release_net(struct inode * ino,struct file * f)94 int single_release_net(struct inode *ino, struct file *f)
95 {
96 struct seq_file *seq = f->private_data;
97 put_net(seq->private);
98 return single_release(ino, f);
99 }
100 EXPORT_SYMBOL_GPL(single_release_net);
101
get_proc_task_net(struct inode * dir)102 static struct net *get_proc_task_net(struct inode *dir)
103 {
104 struct task_struct *task;
105 struct nsproxy *ns;
106 struct net *net = NULL;
107
108 rcu_read_lock();
109 task = pid_task(proc_pid(dir), PIDTYPE_PID);
110 if (task != NULL) {
111 ns = task_nsproxy(task);
112 if (ns != NULL)
113 net = get_net(ns->net_ns);
114 }
115 rcu_read_unlock();
116
117 return net;
118 }
119
proc_tgid_net_lookup(struct inode * dir,struct dentry * dentry,struct nameidata * nd)120 static struct dentry *proc_tgid_net_lookup(struct inode *dir,
121 struct dentry *dentry, struct nameidata *nd)
122 {
123 struct dentry *de;
124 struct net *net;
125
126 de = ERR_PTR(-ENOENT);
127 net = get_proc_task_net(dir);
128 if (net != NULL) {
129 de = proc_lookup_de(net->proc_net, dir, dentry);
130 put_net(net);
131 }
132 return de;
133 }
134
proc_tgid_net_getattr(struct vfsmount * mnt,struct dentry * dentry,struct kstat * stat)135 static int proc_tgid_net_getattr(struct vfsmount *mnt, struct dentry *dentry,
136 struct kstat *stat)
137 {
138 struct inode *inode = dentry->d_inode;
139 struct net *net;
140
141 net = get_proc_task_net(inode);
142
143 generic_fillattr(inode, stat);
144
145 if (net != NULL) {
146 stat->nlink = net->proc_net->nlink;
147 put_net(net);
148 }
149
150 return 0;
151 }
152
153 const struct inode_operations proc_net_inode_operations = {
154 .lookup = proc_tgid_net_lookup,
155 .getattr = proc_tgid_net_getattr,
156 };
157
proc_tgid_net_readdir(struct file * filp,void * dirent,filldir_t filldir)158 static int proc_tgid_net_readdir(struct file *filp, void *dirent,
159 filldir_t filldir)
160 {
161 int ret;
162 struct net *net;
163
164 ret = -EINVAL;
165 net = get_proc_task_net(filp->f_path.dentry->d_inode);
166 if (net != NULL) {
167 ret = proc_readdir_de(net->proc_net, filp, dirent, filldir);
168 put_net(net);
169 }
170 return ret;
171 }
172
173 const struct file_operations proc_net_operations = {
174 .llseek = generic_file_llseek,
175 .read = generic_read_dir,
176 .readdir = proc_tgid_net_readdir,
177 };
178
179
proc_net_fops_create(struct net * net,const char * name,mode_t mode,const struct file_operations * fops)180 struct proc_dir_entry *proc_net_fops_create(struct net *net,
181 const char *name, mode_t mode, const struct file_operations *fops)
182 {
183 return proc_create(name, mode, net->proc_net, fops);
184 }
185 EXPORT_SYMBOL_GPL(proc_net_fops_create);
186
proc_net_remove(struct net * net,const char * name)187 void proc_net_remove(struct net *net, const char *name)
188 {
189 remove_proc_entry(name, net->proc_net);
190 }
191 EXPORT_SYMBOL_GPL(proc_net_remove);
192
proc_net_ns_init(struct net * net)193 static __net_init int proc_net_ns_init(struct net *net)
194 {
195 struct proc_dir_entry *netd, *net_statd;
196 int err;
197
198 err = -ENOMEM;
199 netd = kzalloc(sizeof(*netd), GFP_KERNEL);
200 if (!netd)
201 goto out;
202
203 netd->data = net;
204 netd->nlink = 2;
205 netd->name = "net";
206 netd->namelen = 3;
207 netd->parent = &proc_root;
208
209 err = -EEXIST;
210 net_statd = proc_net_mkdir(net, "stat", netd);
211 if (!net_statd)
212 goto free_net;
213
214 net->proc_net = netd;
215 net->proc_net_stat = net_statd;
216 return 0;
217
218 free_net:
219 kfree(netd);
220 out:
221 return err;
222 }
223
proc_net_ns_exit(struct net * net)224 static __net_exit void proc_net_ns_exit(struct net *net)
225 {
226 remove_proc_entry("stat", net->proc_net);
227 kfree(net->proc_net);
228 }
229
230 static struct pernet_operations __net_initdata proc_net_ns_ops = {
231 .init = proc_net_ns_init,
232 .exit = proc_net_ns_exit,
233 };
234
proc_net_init(void)235 int __init proc_net_init(void)
236 {
237 proc_symlink("net", NULL, "self/net");
238
239 return register_pernet_subsys(&proc_net_ns_ops);
240 }
241