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 <linux/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/sched/task.h>
21#include <linux/module.h>
22#include <linux/bitops.h>
23#include <linux/mount.h>
24#include <linux/nsproxy.h>
25#include <linux/uidgid.h>
26#include <net/net_namespace.h>
27#include <linux/seq_file.h>
28
29#include "internal.h"
30
31static inline struct net *PDE_NET(struct proc_dir_entry *pde)
32{
33 return pde->parent->data;
34}
35
36static struct net *get_proc_net(const struct inode *inode)
37{
38 return maybe_get_net(PDE_NET(PDE(inode)));
39}
40
41int seq_open_net(struct inode *ino, struct file *f,
42 const struct seq_operations *ops, int size)
43{
44 struct net *net;
45 struct seq_net_private *p;
46
47 BUG_ON(size < sizeof(*p));
48
49 net = get_proc_net(ino);
50 if (net == NULL)
51 return -ENXIO;
52
53 p = __seq_open_private(f, ops, size);
54 if (p == NULL) {
55 put_net(net);
56 return -ENOMEM;
57 }
58#ifdef CONFIG_NET_NS
59 p->net = net;
60#endif
61 return 0;
62}
63EXPORT_SYMBOL_GPL(seq_open_net);
64
65int single_open_net(struct inode *inode, struct file *file,
66 int (*show)(struct seq_file *, void *))
67{
68 int err;
69 struct net *net;
70
71 err = -ENXIO;
72 net = get_proc_net(inode);
73 if (net == NULL)
74 goto err_net;
75
76 err = single_open(file, show, net);
77 if (err < 0)
78 goto err_open;
79
80 return 0;
81
82err_open:
83 put_net(net);
84err_net:
85 return err;
86}
87EXPORT_SYMBOL_GPL(single_open_net);
88
89int seq_release_net(struct inode *ino, struct file *f)
90{
91 struct seq_file *seq;
92
93 seq = f->private_data;
94
95 put_net(seq_file_net(seq));
96 seq_release_private(ino, f);
97 return 0;
98}
99EXPORT_SYMBOL_GPL(seq_release_net);
100
101int single_release_net(struct inode *ino, struct file *f)
102{
103 struct seq_file *seq = f->private_data;
104 put_net(seq->private);
105 return single_release(ino, f);
106}
107EXPORT_SYMBOL_GPL(single_release_net);
108
109static struct net *get_proc_task_net(struct inode *dir)
110{
111 struct task_struct *task;
112 struct nsproxy *ns;
113 struct net *net = NULL;
114
115 rcu_read_lock();
116 task = pid_task(proc_pid(dir), PIDTYPE_PID);
117 if (task != NULL) {
118 task_lock(task);
119 ns = task->nsproxy;
120 if (ns != NULL)
121 net = get_net(ns->net_ns);
122 task_unlock(task);
123 }
124 rcu_read_unlock();
125
126 return net;
127}
128
129static struct dentry *proc_tgid_net_lookup(struct inode *dir,
130 struct dentry *dentry, unsigned int flags)
131{
132 struct dentry *de;
133 struct net *net;
134
135 de = ERR_PTR(-ENOENT);
136 net = get_proc_task_net(dir);
137 if (net != NULL) {
138 de = proc_lookup_de(net->proc_net, dir, dentry);
139 put_net(net);
140 }
141 return de;
142}
143
144static int proc_tgid_net_getattr(const struct path *path, struct kstat *stat,
145 u32 request_mask, unsigned int query_flags)
146{
147 struct inode *inode = d_inode(path->dentry);
148 struct net *net;
149
150 net = get_proc_task_net(inode);
151
152 generic_fillattr(inode, stat);
153
154 if (net != NULL) {
155 stat->nlink = net->proc_net->nlink;
156 put_net(net);
157 }
158
159 return 0;
160}
161
162const struct inode_operations proc_net_inode_operations = {
163 .lookup = proc_tgid_net_lookup,
164 .getattr = proc_tgid_net_getattr,
165};
166
167static int proc_tgid_net_readdir(struct file *file, struct dir_context *ctx)
168{
169 int ret;
170 struct net *net;
171
172 ret = -EINVAL;
173 net = get_proc_task_net(file_inode(file));
174 if (net != NULL) {
175 ret = proc_readdir_de(net->proc_net, file, ctx);
176 put_net(net);
177 }
178 return ret;
179}
180
181const struct file_operations proc_net_operations = {
182 .llseek = generic_file_llseek,
183 .read = generic_read_dir,
184 .iterate_shared = proc_tgid_net_readdir,
185};
186
187static __net_init int proc_net_ns_init(struct net *net)
188{
189 struct proc_dir_entry *netd, *net_statd;
190 kuid_t uid;
191 kgid_t gid;
192 int err;
193
194 err = -ENOMEM;
195 netd = kzalloc(sizeof(*netd) + 4, GFP_KERNEL);
196 if (!netd)
197 goto out;
198
199 netd->subdir = RB_ROOT;
200 netd->data = net;
201 netd->nlink = 2;
202 netd->namelen = 3;
203 netd->parent = &proc_root;
204 memcpy(netd->name, "net", 4);
205
206 uid = make_kuid(net->user_ns, 0);
207 if (!uid_valid(uid))
208 uid = netd->uid;
209
210 gid = make_kgid(net->user_ns, 0);
211 if (!gid_valid(gid))
212 gid = netd->gid;
213
214 proc_set_user(netd, uid, gid);
215
216 err = -EEXIST;
217 net_statd = proc_net_mkdir(net, "stat", netd);
218 if (!net_statd)
219 goto free_net;
220
221 net->proc_net = netd;
222 net->proc_net_stat = net_statd;
223 return 0;
224
225free_net:
226 kfree(netd);
227out:
228 return err;
229}
230
231static __net_exit void proc_net_ns_exit(struct net *net)
232{
233 remove_proc_entry("stat", net->proc_net);
234 kfree(net->proc_net);
235}
236
237static struct pernet_operations __net_initdata proc_net_ns_ops = {
238 .init = proc_net_ns_init,
239 .exit = proc_net_ns_exit,
240};
241
242int __init proc_net_init(void)
243{
244 proc_symlink("net", NULL, "self/net");
245
246 return register_pernet_subsys(&proc_net_ns_ops);
247}