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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
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}
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 proc_ops proc_net_seq_ops = {
94 .proc_open = seq_open_net,
95 .proc_read = seq_read,
96 .proc_write = proc_simple_write,
97 .proc_lseek = seq_lseek,
98 .proc_release = seq_release_net,
99};
100
101int bpf_iter_init_seq_net(void *priv_data, struct bpf_iter_aux_info *aux)
102{
103#ifdef CONFIG_NET_NS
104 struct seq_net_private *p = priv_data;
105
106 p->net = get_net(current->nsproxy->net_ns);
107#endif
108 return 0;
109}
110
111void bpf_iter_fini_seq_net(void *priv_data)
112{
113#ifdef CONFIG_NET_NS
114 struct seq_net_private *p = priv_data;
115
116 put_net(p->net);
117#endif
118}
119
120struct proc_dir_entry *proc_create_net_data(const char *name, umode_t mode,
121 struct proc_dir_entry *parent, const struct seq_operations *ops,
122 unsigned int state_size, void *data)
123{
124 struct proc_dir_entry *p;
125
126 p = proc_create_reg(name, mode, &parent, data);
127 if (!p)
128 return NULL;
129 pde_force_lookup(p);
130 p->proc_ops = &proc_net_seq_ops;
131 p->seq_ops = ops;
132 p->state_size = state_size;
133 return proc_register(parent, p);
134}
135EXPORT_SYMBOL_GPL(proc_create_net_data);
136
137/**
138 * proc_create_net_data_write - Create a writable net_ns-specific proc file
139 * @name: The name of the file.
140 * @mode: The file's access mode.
141 * @parent: The parent directory in which to create.
142 * @ops: The seq_file ops with which to read the file.
143 * @write: The write method which which to 'modify' the file.
144 * @data: Data for retrieval by PDE_DATA().
145 *
146 * Create a network namespaced proc file in the @parent directory with the
147 * specified @name and @mode that allows reading of a file that displays a
148 * series of elements and also provides for the file accepting writes that have
149 * some arbitrary effect.
150 *
151 * The functions in the @ops table are used to iterate over items to be
152 * presented and extract the readable content using the seq_file interface.
153 *
154 * The @write function is called with the data copied into a kernel space
155 * scratch buffer and has a NUL appended for convenience. The buffer may be
156 * modified by the @write function. @write should return 0 on success.
157 *
158 * The @data value is accessible from the @show and @write functions by calling
159 * PDE_DATA() on the file inode. The network namespace must be accessed by
160 * calling seq_file_net() on the seq_file struct.
161 */
162struct proc_dir_entry *proc_create_net_data_write(const char *name, umode_t mode,
163 struct proc_dir_entry *parent,
164 const struct seq_operations *ops,
165 proc_write_t write,
166 unsigned int state_size, void *data)
167{
168 struct proc_dir_entry *p;
169
170 p = proc_create_reg(name, mode, &parent, data);
171 if (!p)
172 return NULL;
173 pde_force_lookup(p);
174 p->proc_ops = &proc_net_seq_ops;
175 p->seq_ops = ops;
176 p->state_size = state_size;
177 p->write = write;
178 return proc_register(parent, p);
179}
180EXPORT_SYMBOL_GPL(proc_create_net_data_write);
181
182static int single_open_net(struct inode *inode, struct file *file)
183{
184 struct proc_dir_entry *de = PDE(inode);
185 struct net *net;
186 int err;
187
188 net = get_proc_net(inode);
189 if (!net)
190 return -ENXIO;
191
192 err = single_open(file, de->single_show, net);
193 if (err)
194 put_net(net);
195 return err;
196}
197
198static int single_release_net(struct inode *ino, struct file *f)
199{
200 struct seq_file *seq = f->private_data;
201 put_net(seq->private);
202 return single_release(ino, f);
203}
204
205static const struct proc_ops proc_net_single_ops = {
206 .proc_open = single_open_net,
207 .proc_read = seq_read,
208 .proc_write = proc_simple_write,
209 .proc_lseek = seq_lseek,
210 .proc_release = single_release_net,
211};
212
213struct proc_dir_entry *proc_create_net_single(const char *name, umode_t mode,
214 struct proc_dir_entry *parent,
215 int (*show)(struct seq_file *, void *), void *data)
216{
217 struct proc_dir_entry *p;
218
219 p = proc_create_reg(name, mode, &parent, data);
220 if (!p)
221 return NULL;
222 pde_force_lookup(p);
223 p->proc_ops = &proc_net_single_ops;
224 p->single_show = show;
225 return proc_register(parent, p);
226}
227EXPORT_SYMBOL_GPL(proc_create_net_single);
228
229/**
230 * proc_create_net_single_write - Create a writable net_ns-specific proc file
231 * @name: The name of the file.
232 * @mode: The file's access mode.
233 * @parent: The parent directory in which to create.
234 * @show: The seqfile show method with which to read the file.
235 * @write: The write method which which to 'modify' the file.
236 * @data: Data for retrieval by PDE_DATA().
237 *
238 * Create a network-namespaced proc file in the @parent directory with the
239 * specified @name and @mode that allows reading of a file that displays a
240 * single element rather than a series and also provides for the file accepting
241 * writes that have some arbitrary effect.
242 *
243 * The @show function is called to extract the readable content via the
244 * seq_file interface.
245 *
246 * The @write function is called with the data copied into a kernel space
247 * scratch buffer and has a NUL appended for convenience. The buffer may be
248 * modified by the @write function. @write should return 0 on success.
249 *
250 * The @data value is accessible from the @show and @write functions by calling
251 * PDE_DATA() on the file inode. The network namespace must be accessed by
252 * calling seq_file_single_net() on the seq_file struct.
253 */
254struct proc_dir_entry *proc_create_net_single_write(const char *name, umode_t mode,
255 struct proc_dir_entry *parent,
256 int (*show)(struct seq_file *, void *),
257 proc_write_t write,
258 void *data)
259{
260 struct proc_dir_entry *p;
261
262 p = proc_create_reg(name, mode, &parent, data);
263 if (!p)
264 return NULL;
265 pde_force_lookup(p);
266 p->proc_ops = &proc_net_single_ops;
267 p->single_show = show;
268 p->write = write;
269 return proc_register(parent, p);
270}
271EXPORT_SYMBOL_GPL(proc_create_net_single_write);
272
273static struct net *get_proc_task_net(struct inode *dir)
274{
275 struct task_struct *task;
276 struct nsproxy *ns;
277 struct net *net = NULL;
278
279 rcu_read_lock();
280 task = pid_task(proc_pid(dir), PIDTYPE_PID);
281 if (task != NULL) {
282 task_lock(task);
283 ns = task->nsproxy;
284 if (ns != NULL)
285 net = get_net(ns->net_ns);
286 task_unlock(task);
287 }
288 rcu_read_unlock();
289
290 return net;
291}
292
293static struct dentry *proc_tgid_net_lookup(struct inode *dir,
294 struct dentry *dentry, unsigned int flags)
295{
296 struct dentry *de;
297 struct net *net;
298
299 de = ERR_PTR(-ENOENT);
300 net = get_proc_task_net(dir);
301 if (net != NULL) {
302 de = proc_lookup_de(dir, dentry, net->proc_net);
303 put_net(net);
304 }
305 return de;
306}
307
308static int proc_tgid_net_getattr(const struct path *path, struct kstat *stat,
309 u32 request_mask, unsigned int query_flags)
310{
311 struct inode *inode = d_inode(path->dentry);
312 struct net *net;
313
314 net = get_proc_task_net(inode);
315
316 generic_fillattr(inode, stat);
317
318 if (net != NULL) {
319 stat->nlink = net->proc_net->nlink;
320 put_net(net);
321 }
322
323 return 0;
324}
325
326const struct inode_operations proc_net_inode_operations = {
327 .lookup = proc_tgid_net_lookup,
328 .getattr = proc_tgid_net_getattr,
329};
330
331static int proc_tgid_net_readdir(struct file *file, struct dir_context *ctx)
332{
333 int ret;
334 struct net *net;
335
336 ret = -EINVAL;
337 net = get_proc_task_net(file_inode(file));
338 if (net != NULL) {
339 ret = proc_readdir_de(file, ctx, net->proc_net);
340 put_net(net);
341 }
342 return ret;
343}
344
345const struct file_operations proc_net_operations = {
346 .llseek = generic_file_llseek,
347 .read = generic_read_dir,
348 .iterate_shared = proc_tgid_net_readdir,
349};
350
351static __net_init int proc_net_ns_init(struct net *net)
352{
353 struct proc_dir_entry *netd, *net_statd;
354 kuid_t uid;
355 kgid_t gid;
356 int err;
357
358 err = -ENOMEM;
359 netd = kmem_cache_zalloc(proc_dir_entry_cache, GFP_KERNEL);
360 if (!netd)
361 goto out;
362
363 netd->subdir = RB_ROOT;
364 netd->data = net;
365 netd->nlink = 2;
366 netd->namelen = 3;
367 netd->parent = &proc_root;
368 netd->name = netd->inline_name;
369 memcpy(netd->name, "net", 4);
370
371 uid = make_kuid(net->user_ns, 0);
372 if (!uid_valid(uid))
373 uid = netd->uid;
374
375 gid = make_kgid(net->user_ns, 0);
376 if (!gid_valid(gid))
377 gid = netd->gid;
378
379 proc_set_user(netd, uid, gid);
380
381 err = -EEXIST;
382 net_statd = proc_net_mkdir(net, "stat", netd);
383 if (!net_statd)
384 goto free_net;
385
386 net->proc_net = netd;
387 net->proc_net_stat = net_statd;
388 return 0;
389
390free_net:
391 pde_free(netd);
392out:
393 return err;
394}
395
396static __net_exit void proc_net_ns_exit(struct net *net)
397{
398 remove_proc_entry("stat", net->proc_net);
399 pde_free(net->proc_net);
400}
401
402static struct pernet_operations __net_initdata proc_net_ns_ops = {
403 .init = proc_net_ns_init,
404 .exit = proc_net_ns_exit,
405};
406
407int __init proc_net_init(void)
408{
409 proc_symlink("net", NULL, "self/net");
410
411 return register_pernet_subsys(&proc_net_ns_ops);
412}