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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
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 = d_inode(dentry);
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->subdir = RB_ROOT;
196 netd->data = net;
197 netd->nlink = 2;
198 netd->namelen = 3;
199 netd->parent = &proc_root;
200 memcpy(netd->name, "net", 4);
201
202 err = -EEXIST;
203 net_statd = proc_net_mkdir(net, "stat", netd);
204 if (!net_statd)
205 goto free_net;
206
207 net->proc_net = netd;
208 net->proc_net_stat = net_statd;
209 return 0;
210
211free_net:
212 kfree(netd);
213out:
214 return err;
215}
216
217static __net_exit void proc_net_ns_exit(struct net *net)
218{
219 remove_proc_entry("stat", net->proc_net);
220 kfree(net->proc_net);
221}
222
223static struct pernet_operations __net_initdata proc_net_ns_ops = {
224 .init = proc_net_ns_init,
225 .exit = proc_net_ns_exit,
226};
227
228int __init proc_net_init(void)
229{
230 proc_symlink("net", NULL, "self/net");
231
232 return register_pernet_subsys(&proc_net_ns_ops);
233}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/fs/proc/net.c
4 *
5 * Copyright (C) 2007
6 *
7 * Author: Eric Biederman <ebiederm@xmission.com>
8 *
9 * proc net directory handling functions
10 */
11
12#include <linux/uaccess.h>
13
14#include <linux/errno.h>
15#include <linux/time.h>
16#include <linux/proc_fs.h>
17#include <linux/stat.h>
18#include <linux/slab.h>
19#include <linux/init.h>
20#include <linux/sched.h>
21#include <linux/sched/task.h>
22#include <linux/module.h>
23#include <linux/bitops.h>
24#include <linux/mount.h>
25#include <linux/nsproxy.h>
26#include <linux/uidgid.h>
27#include <net/net_namespace.h>
28#include <linux/seq_file.h>
29
30#include "internal.h"
31
32static inline struct net *PDE_NET(struct proc_dir_entry *pde)
33{
34 return pde->parent->data;
35}
36
37static struct net *get_proc_net(const struct inode *inode)
38{
39 return maybe_get_net(PDE_NET(PDE(inode)));
40}
41
42static int proc_net_d_revalidate(struct dentry *dentry, unsigned int flags)
43{
44 return 0;
45}
46
47static const struct dentry_operations proc_net_dentry_ops = {
48 .d_revalidate = proc_net_d_revalidate,
49 .d_delete = always_delete_dentry,
50};
51
52static void pde_force_lookup(struct proc_dir_entry *pde)
53{
54 /* /proc/net/ entries can be changed under us by setns(CLONE_NEWNET) */
55 pde->proc_dops = &proc_net_dentry_ops;
56}
57
58static int seq_open_net(struct inode *inode, struct file *file)
59{
60 unsigned int state_size = PDE(inode)->state_size;
61 struct seq_net_private *p;
62 struct net *net;
63
64 WARN_ON_ONCE(state_size < sizeof(*p));
65
66 if (file->f_mode & FMODE_WRITE && !PDE(inode)->write)
67 return -EACCES;
68
69 net = get_proc_net(inode);
70 if (!net)
71 return -ENXIO;
72
73 p = __seq_open_private(file, PDE(inode)->seq_ops, state_size);
74 if (!p) {
75 put_net(net);
76 return -ENOMEM;
77 }
78#ifdef CONFIG_NET_NS
79 p->net = net;
80#endif
81 return 0;
82}
83
84static int seq_release_net(struct inode *ino, struct file *f)
85{
86 struct seq_file *seq = f->private_data;
87
88 put_net(seq_file_net(seq));
89 seq_release_private(ino, f);
90 return 0;
91}
92
93static const struct file_operations proc_net_seq_fops = {
94 .open = seq_open_net,
95 .read = seq_read,
96 .write = proc_simple_write,
97 .llseek = seq_lseek,
98 .release = seq_release_net,
99};
100
101struct proc_dir_entry *proc_create_net_data(const char *name, umode_t mode,
102 struct proc_dir_entry *parent, const struct seq_operations *ops,
103 unsigned int state_size, void *data)
104{
105 struct proc_dir_entry *p;
106
107 p = proc_create_reg(name, mode, &parent, data);
108 if (!p)
109 return NULL;
110 pde_force_lookup(p);
111 p->proc_fops = &proc_net_seq_fops;
112 p->seq_ops = ops;
113 p->state_size = state_size;
114 return proc_register(parent, p);
115}
116EXPORT_SYMBOL_GPL(proc_create_net_data);
117
118/**
119 * proc_create_net_data_write - Create a writable net_ns-specific proc file
120 * @name: The name of the file.
121 * @mode: The file's access mode.
122 * @parent: The parent directory in which to create.
123 * @ops: The seq_file ops with which to read the file.
124 * @write: The write method which which to 'modify' the file.
125 * @data: Data for retrieval by PDE_DATA().
126 *
127 * Create a network namespaced proc file in the @parent directory with the
128 * specified @name and @mode that allows reading of a file that displays a
129 * series of elements and also provides for the file accepting writes that have
130 * some arbitrary effect.
131 *
132 * The functions in the @ops table are used to iterate over items to be
133 * presented and extract the readable content using the seq_file interface.
134 *
135 * The @write function is called with the data copied into a kernel space
136 * scratch buffer and has a NUL appended for convenience. The buffer may be
137 * modified by the @write function. @write should return 0 on success.
138 *
139 * The @data value is accessible from the @show and @write functions by calling
140 * PDE_DATA() on the file inode. The network namespace must be accessed by
141 * calling seq_file_net() on the seq_file struct.
142 */
143struct proc_dir_entry *proc_create_net_data_write(const char *name, umode_t mode,
144 struct proc_dir_entry *parent,
145 const struct seq_operations *ops,
146 proc_write_t write,
147 unsigned int state_size, void *data)
148{
149 struct proc_dir_entry *p;
150
151 p = proc_create_reg(name, mode, &parent, data);
152 if (!p)
153 return NULL;
154 pde_force_lookup(p);
155 p->proc_fops = &proc_net_seq_fops;
156 p->seq_ops = ops;
157 p->state_size = state_size;
158 p->write = write;
159 return proc_register(parent, p);
160}
161EXPORT_SYMBOL_GPL(proc_create_net_data_write);
162
163static int single_open_net(struct inode *inode, struct file *file)
164{
165 struct proc_dir_entry *de = PDE(inode);
166 struct net *net;
167 int err;
168
169 net = get_proc_net(inode);
170 if (!net)
171 return -ENXIO;
172
173 err = single_open(file, de->single_show, net);
174 if (err)
175 put_net(net);
176 return err;
177}
178
179static int single_release_net(struct inode *ino, struct file *f)
180{
181 struct seq_file *seq = f->private_data;
182 put_net(seq->private);
183 return single_release(ino, f);
184}
185
186static const struct file_operations proc_net_single_fops = {
187 .open = single_open_net,
188 .read = seq_read,
189 .write = proc_simple_write,
190 .llseek = seq_lseek,
191 .release = single_release_net,
192};
193
194struct proc_dir_entry *proc_create_net_single(const char *name, umode_t mode,
195 struct proc_dir_entry *parent,
196 int (*show)(struct seq_file *, void *), void *data)
197{
198 struct proc_dir_entry *p;
199
200 p = proc_create_reg(name, mode, &parent, data);
201 if (!p)
202 return NULL;
203 pde_force_lookup(p);
204 p->proc_fops = &proc_net_single_fops;
205 p->single_show = show;
206 return proc_register(parent, p);
207}
208EXPORT_SYMBOL_GPL(proc_create_net_single);
209
210/**
211 * proc_create_net_single_write - Create a writable net_ns-specific proc file
212 * @name: The name of the file.
213 * @mode: The file's access mode.
214 * @parent: The parent directory in which to create.
215 * @show: The seqfile show method with which to read the file.
216 * @write: The write method which which to 'modify' the file.
217 * @data: Data for retrieval by PDE_DATA().
218 *
219 * Create a network-namespaced proc file in the @parent directory with the
220 * specified @name and @mode that allows reading of a file that displays a
221 * single element rather than a series and also provides for the file accepting
222 * writes that have some arbitrary effect.
223 *
224 * The @show function is called to extract the readable content via the
225 * seq_file interface.
226 *
227 * The @write function is called with the data copied into a kernel space
228 * scratch buffer and has a NUL appended for convenience. The buffer may be
229 * modified by the @write function. @write should return 0 on success.
230 *
231 * The @data value is accessible from the @show and @write functions by calling
232 * PDE_DATA() on the file inode. The network namespace must be accessed by
233 * calling seq_file_single_net() on the seq_file struct.
234 */
235struct proc_dir_entry *proc_create_net_single_write(const char *name, umode_t mode,
236 struct proc_dir_entry *parent,
237 int (*show)(struct seq_file *, void *),
238 proc_write_t write,
239 void *data)
240{
241 struct proc_dir_entry *p;
242
243 p = proc_create_reg(name, mode, &parent, data);
244 if (!p)
245 return NULL;
246 pde_force_lookup(p);
247 p->proc_fops = &proc_net_single_fops;
248 p->single_show = show;
249 p->write = write;
250 return proc_register(parent, p);
251}
252EXPORT_SYMBOL_GPL(proc_create_net_single_write);
253
254static struct net *get_proc_task_net(struct inode *dir)
255{
256 struct task_struct *task;
257 struct nsproxy *ns;
258 struct net *net = NULL;
259
260 rcu_read_lock();
261 task = pid_task(proc_pid(dir), PIDTYPE_PID);
262 if (task != NULL) {
263 task_lock(task);
264 ns = task->nsproxy;
265 if (ns != NULL)
266 net = get_net(ns->net_ns);
267 task_unlock(task);
268 }
269 rcu_read_unlock();
270
271 return net;
272}
273
274static struct dentry *proc_tgid_net_lookup(struct inode *dir,
275 struct dentry *dentry, unsigned int flags)
276{
277 struct dentry *de;
278 struct net *net;
279
280 de = ERR_PTR(-ENOENT);
281 net = get_proc_task_net(dir);
282 if (net != NULL) {
283 de = proc_lookup_de(dir, dentry, net->proc_net);
284 put_net(net);
285 }
286 return de;
287}
288
289static int proc_tgid_net_getattr(const struct path *path, struct kstat *stat,
290 u32 request_mask, unsigned int query_flags)
291{
292 struct inode *inode = d_inode(path->dentry);
293 struct net *net;
294
295 net = get_proc_task_net(inode);
296
297 generic_fillattr(inode, stat);
298
299 if (net != NULL) {
300 stat->nlink = net->proc_net->nlink;
301 put_net(net);
302 }
303
304 return 0;
305}
306
307const struct inode_operations proc_net_inode_operations = {
308 .lookup = proc_tgid_net_lookup,
309 .getattr = proc_tgid_net_getattr,
310};
311
312static int proc_tgid_net_readdir(struct file *file, struct dir_context *ctx)
313{
314 int ret;
315 struct net *net;
316
317 ret = -EINVAL;
318 net = get_proc_task_net(file_inode(file));
319 if (net != NULL) {
320 ret = proc_readdir_de(file, ctx, net->proc_net);
321 put_net(net);
322 }
323 return ret;
324}
325
326const struct file_operations proc_net_operations = {
327 .llseek = generic_file_llseek,
328 .read = generic_read_dir,
329 .iterate_shared = proc_tgid_net_readdir,
330};
331
332static __net_init int proc_net_ns_init(struct net *net)
333{
334 struct proc_dir_entry *netd, *net_statd;
335 kuid_t uid;
336 kgid_t gid;
337 int err;
338
339 err = -ENOMEM;
340 netd = kmem_cache_zalloc(proc_dir_entry_cache, GFP_KERNEL);
341 if (!netd)
342 goto out;
343
344 netd->subdir = RB_ROOT;
345 netd->data = net;
346 netd->nlink = 2;
347 netd->namelen = 3;
348 netd->parent = &proc_root;
349 netd->name = netd->inline_name;
350 memcpy(netd->name, "net", 4);
351
352 uid = make_kuid(net->user_ns, 0);
353 if (!uid_valid(uid))
354 uid = netd->uid;
355
356 gid = make_kgid(net->user_ns, 0);
357 if (!gid_valid(gid))
358 gid = netd->gid;
359
360 proc_set_user(netd, uid, gid);
361
362 err = -EEXIST;
363 net_statd = proc_net_mkdir(net, "stat", netd);
364 if (!net_statd)
365 goto free_net;
366
367 net->proc_net = netd;
368 net->proc_net_stat = net_statd;
369 return 0;
370
371free_net:
372 pde_free(netd);
373out:
374 return err;
375}
376
377static __net_exit void proc_net_ns_exit(struct net *net)
378{
379 remove_proc_entry("stat", net->proc_net);
380 pde_free(net->proc_net);
381}
382
383static struct pernet_operations __net_initdata proc_net_ns_ops = {
384 .init = proc_net_ns_init,
385 .exit = proc_net_ns_exit,
386};
387
388int __init proc_net_init(void)
389{
390 proc_symlink("net", NULL, "self/net");
391
392 return register_pernet_subsys(&proc_net_ns_ops);
393}