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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 seq_open_net(struct inode *inode, struct file *file)
43{
44 unsigned int state_size = PDE(inode)->state_size;
45 struct seq_net_private *p;
46 struct net *net;
47
48 WARN_ON_ONCE(state_size < sizeof(*p));
49
50 if (file->f_mode & FMODE_WRITE && !PDE(inode)->write)
51 return -EACCES;
52
53 net = get_proc_net(inode);
54 if (!net)
55 return -ENXIO;
56
57 p = __seq_open_private(file, PDE(inode)->seq_ops, state_size);
58 if (!p) {
59 put_net(net);
60 return -ENOMEM;
61 }
62#ifdef CONFIG_NET_NS
63 p->net = net;
64#endif
65 return 0;
66}
67
68static int seq_release_net(struct inode *ino, struct file *f)
69{
70 struct seq_file *seq = f->private_data;
71
72 put_net(seq_file_net(seq));
73 seq_release_private(ino, f);
74 return 0;
75}
76
77static const struct proc_ops proc_net_seq_ops = {
78 .proc_open = seq_open_net,
79 .proc_read = seq_read,
80 .proc_write = proc_simple_write,
81 .proc_lseek = seq_lseek,
82 .proc_release = seq_release_net,
83};
84
85int bpf_iter_init_seq_net(void *priv_data, struct bpf_iter_aux_info *aux)
86{
87#ifdef CONFIG_NET_NS
88 struct seq_net_private *p = priv_data;
89
90 p->net = get_net(current->nsproxy->net_ns);
91#endif
92 return 0;
93}
94
95void bpf_iter_fini_seq_net(void *priv_data)
96{
97#ifdef CONFIG_NET_NS
98 struct seq_net_private *p = priv_data;
99
100 put_net(p->net);
101#endif
102}
103
104struct proc_dir_entry *proc_create_net_data(const char *name, umode_t mode,
105 struct proc_dir_entry *parent, const struct seq_operations *ops,
106 unsigned int state_size, void *data)
107{
108 struct proc_dir_entry *p;
109
110 p = proc_create_reg(name, mode, &parent, data);
111 if (!p)
112 return NULL;
113 pde_force_lookup(p);
114 p->proc_ops = &proc_net_seq_ops;
115 p->seq_ops = ops;
116 p->state_size = state_size;
117 return proc_register(parent, p);
118}
119EXPORT_SYMBOL_GPL(proc_create_net_data);
120
121/**
122 * proc_create_net_data_write - Create a writable net_ns-specific proc file
123 * @name: The name of the file.
124 * @mode: The file's access mode.
125 * @parent: The parent directory in which to create.
126 * @ops: The seq_file ops with which to read the file.
127 * @write: The write method with which to 'modify' the file.
128 * @data: Data for retrieval by PDE_DATA().
129 *
130 * Create a network namespaced proc file in the @parent directory with the
131 * specified @name and @mode that allows reading of a file that displays a
132 * series of elements and also provides for the file accepting writes that have
133 * some arbitrary effect.
134 *
135 * The functions in the @ops table are used to iterate over items to be
136 * presented and extract the readable content using the seq_file interface.
137 *
138 * The @write function is called with the data copied into a kernel space
139 * scratch buffer and has a NUL appended for convenience. The buffer may be
140 * modified by the @write function. @write should return 0 on success.
141 *
142 * The @data value is accessible from the @show and @write functions by calling
143 * PDE_DATA() on the file inode. The network namespace must be accessed by
144 * calling seq_file_net() on the seq_file struct.
145 */
146struct proc_dir_entry *proc_create_net_data_write(const char *name, umode_t mode,
147 struct proc_dir_entry *parent,
148 const struct seq_operations *ops,
149 proc_write_t write,
150 unsigned int state_size, void *data)
151{
152 struct proc_dir_entry *p;
153
154 p = proc_create_reg(name, mode, &parent, data);
155 if (!p)
156 return NULL;
157 pde_force_lookup(p);
158 p->proc_ops = &proc_net_seq_ops;
159 p->seq_ops = ops;
160 p->state_size = state_size;
161 p->write = write;
162 return proc_register(parent, p);
163}
164EXPORT_SYMBOL_GPL(proc_create_net_data_write);
165
166static int single_open_net(struct inode *inode, struct file *file)
167{
168 struct proc_dir_entry *de = PDE(inode);
169 struct net *net;
170 int err;
171
172 net = get_proc_net(inode);
173 if (!net)
174 return -ENXIO;
175
176 err = single_open(file, de->single_show, net);
177 if (err)
178 put_net(net);
179 return err;
180}
181
182static int single_release_net(struct inode *ino, struct file *f)
183{
184 struct seq_file *seq = f->private_data;
185 put_net(seq->private);
186 return single_release(ino, f);
187}
188
189static const struct proc_ops proc_net_single_ops = {
190 .proc_open = single_open_net,
191 .proc_read = seq_read,
192 .proc_write = proc_simple_write,
193 .proc_lseek = seq_lseek,
194 .proc_release = single_release_net,
195};
196
197struct proc_dir_entry *proc_create_net_single(const char *name, umode_t mode,
198 struct proc_dir_entry *parent,
199 int (*show)(struct seq_file *, void *), void *data)
200{
201 struct proc_dir_entry *p;
202
203 p = proc_create_reg(name, mode, &parent, data);
204 if (!p)
205 return NULL;
206 pde_force_lookup(p);
207 p->proc_ops = &proc_net_single_ops;
208 p->single_show = show;
209 return proc_register(parent, p);
210}
211EXPORT_SYMBOL_GPL(proc_create_net_single);
212
213/**
214 * proc_create_net_single_write - Create a writable net_ns-specific proc file
215 * @name: The name of the file.
216 * @mode: The file's access mode.
217 * @parent: The parent directory in which to create.
218 * @show: The seqfile show method with which to read the file.
219 * @write: The write method with which to 'modify' the file.
220 * @data: Data for retrieval by PDE_DATA().
221 *
222 * Create a network-namespaced proc file in the @parent directory with the
223 * specified @name and @mode that allows reading of a file that displays a
224 * single element rather than a series and also provides for the file accepting
225 * writes that have some arbitrary effect.
226 *
227 * The @show function is called to extract the readable content via the
228 * seq_file interface.
229 *
230 * The @write function is called with the data copied into a kernel space
231 * scratch buffer and has a NUL appended for convenience. The buffer may be
232 * modified by the @write function. @write should return 0 on success.
233 *
234 * The @data value is accessible from the @show and @write functions by calling
235 * PDE_DATA() on the file inode. The network namespace must be accessed by
236 * calling seq_file_single_net() on the seq_file struct.
237 */
238struct proc_dir_entry *proc_create_net_single_write(const char *name, umode_t mode,
239 struct proc_dir_entry *parent,
240 int (*show)(struct seq_file *, void *),
241 proc_write_t write,
242 void *data)
243{
244 struct proc_dir_entry *p;
245
246 p = proc_create_reg(name, mode, &parent, data);
247 if (!p)
248 return NULL;
249 pde_force_lookup(p);
250 p->proc_ops = &proc_net_single_ops;
251 p->single_show = show;
252 p->write = write;
253 return proc_register(parent, p);
254}
255EXPORT_SYMBOL_GPL(proc_create_net_single_write);
256
257static struct net *get_proc_task_net(struct inode *dir)
258{
259 struct task_struct *task;
260 struct nsproxy *ns;
261 struct net *net = NULL;
262
263 rcu_read_lock();
264 task = pid_task(proc_pid(dir), PIDTYPE_PID);
265 if (task != NULL) {
266 task_lock(task);
267 ns = task->nsproxy;
268 if (ns != NULL)
269 net = get_net(ns->net_ns);
270 task_unlock(task);
271 }
272 rcu_read_unlock();
273
274 return net;
275}
276
277static struct dentry *proc_tgid_net_lookup(struct inode *dir,
278 struct dentry *dentry, unsigned int flags)
279{
280 struct dentry *de;
281 struct net *net;
282
283 de = ERR_PTR(-ENOENT);
284 net = get_proc_task_net(dir);
285 if (net != NULL) {
286 de = proc_lookup_de(dir, dentry, net->proc_net);
287 put_net(net);
288 }
289 return de;
290}
291
292static int proc_tgid_net_getattr(struct user_namespace *mnt_userns,
293 const struct path *path, struct kstat *stat,
294 u32 request_mask, unsigned int query_flags)
295{
296 struct inode *inode = d_inode(path->dentry);
297 struct net *net;
298
299 net = get_proc_task_net(inode);
300
301 generic_fillattr(&init_user_ns, inode, stat);
302
303 if (net != NULL) {
304 stat->nlink = net->proc_net->nlink;
305 put_net(net);
306 }
307
308 return 0;
309}
310
311const struct inode_operations proc_net_inode_operations = {
312 .lookup = proc_tgid_net_lookup,
313 .getattr = proc_tgid_net_getattr,
314};
315
316static int proc_tgid_net_readdir(struct file *file, struct dir_context *ctx)
317{
318 int ret;
319 struct net *net;
320
321 ret = -EINVAL;
322 net = get_proc_task_net(file_inode(file));
323 if (net != NULL) {
324 ret = proc_readdir_de(file, ctx, net->proc_net);
325 put_net(net);
326 }
327 return ret;
328}
329
330const struct file_operations proc_net_operations = {
331 .llseek = generic_file_llseek,
332 .read = generic_read_dir,
333 .iterate_shared = proc_tgid_net_readdir,
334};
335
336static __net_init int proc_net_ns_init(struct net *net)
337{
338 struct proc_dir_entry *netd, *net_statd;
339 kuid_t uid;
340 kgid_t gid;
341 int err;
342
343 err = -ENOMEM;
344 netd = kmem_cache_zalloc(proc_dir_entry_cache, GFP_KERNEL);
345 if (!netd)
346 goto out;
347
348 netd->subdir = RB_ROOT;
349 netd->data = net;
350 netd->nlink = 2;
351 netd->namelen = 3;
352 netd->parent = &proc_root;
353 netd->name = netd->inline_name;
354 memcpy(netd->name, "net", 4);
355
356 uid = make_kuid(net->user_ns, 0);
357 if (!uid_valid(uid))
358 uid = netd->uid;
359
360 gid = make_kgid(net->user_ns, 0);
361 if (!gid_valid(gid))
362 gid = netd->gid;
363
364 proc_set_user(netd, uid, gid);
365
366 err = -EEXIST;
367 net_statd = proc_net_mkdir(net, "stat", netd);
368 if (!net_statd)
369 goto free_net;
370
371 net->proc_net = netd;
372 net->proc_net_stat = net_statd;
373 return 0;
374
375free_net:
376 pde_free(netd);
377out:
378 return err;
379}
380
381static __net_exit void proc_net_ns_exit(struct net *net)
382{
383 remove_proc_entry("stat", net->proc_net);
384 pde_free(net->proc_net);
385}
386
387static struct pernet_operations __net_initdata proc_net_ns_ops = {
388 .init = proc_net_ns_init,
389 .exit = proc_net_ns_exit,
390};
391
392int __init proc_net_init(void)
393{
394 proc_symlink("net", NULL, "self/net");
395
396 return register_pernet_subsys(&proc_net_ns_ops);
397}
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/module.h>
21#include <linux/bitops.h>
22#include <linux/mount.h>
23#include <linux/nsproxy.h>
24#include <linux/uidgid.h>
25#include <net/net_namespace.h>
26#include <linux/seq_file.h>
27
28#include "internal.h"
29
30static inline struct net *PDE_NET(struct proc_dir_entry *pde)
31{
32 return pde->parent->data;
33}
34
35static struct net *get_proc_net(const struct inode *inode)
36{
37 return maybe_get_net(PDE_NET(PDE(inode)));
38}
39
40int seq_open_net(struct inode *ino, struct file *f,
41 const struct seq_operations *ops, int size)
42{
43 struct net *net;
44 struct seq_net_private *p;
45
46 BUG_ON(size < sizeof(*p));
47
48 net = get_proc_net(ino);
49 if (net == NULL)
50 return -ENXIO;
51
52 p = __seq_open_private(f, ops, size);
53 if (p == NULL) {
54 put_net(net);
55 return -ENOMEM;
56 }
57#ifdef CONFIG_NET_NS
58 p->net = net;
59#endif
60 return 0;
61}
62EXPORT_SYMBOL_GPL(seq_open_net);
63
64int single_open_net(struct inode *inode, struct file *file,
65 int (*show)(struct seq_file *, void *))
66{
67 int err;
68 struct net *net;
69
70 err = -ENXIO;
71 net = get_proc_net(inode);
72 if (net == NULL)
73 goto err_net;
74
75 err = single_open(file, show, net);
76 if (err < 0)
77 goto err_open;
78
79 return 0;
80
81err_open:
82 put_net(net);
83err_net:
84 return err;
85}
86EXPORT_SYMBOL_GPL(single_open_net);
87
88int seq_release_net(struct inode *ino, struct file *f)
89{
90 struct seq_file *seq;
91
92 seq = f->private_data;
93
94 put_net(seq_file_net(seq));
95 seq_release_private(ino, f);
96 return 0;
97}
98EXPORT_SYMBOL_GPL(seq_release_net);
99
100int single_release_net(struct inode *ino, struct file *f)
101{
102 struct seq_file *seq = f->private_data;
103 put_net(seq->private);
104 return single_release(ino, f);
105}
106EXPORT_SYMBOL_GPL(single_release_net);
107
108static struct net *get_proc_task_net(struct inode *dir)
109{
110 struct task_struct *task;
111 struct nsproxy *ns;
112 struct net *net = NULL;
113
114 rcu_read_lock();
115 task = pid_task(proc_pid(dir), PIDTYPE_PID);
116 if (task != NULL) {
117 task_lock(task);
118 ns = task->nsproxy;
119 if (ns != NULL)
120 net = get_net(ns->net_ns);
121 task_unlock(task);
122 }
123 rcu_read_unlock();
124
125 return net;
126}
127
128static struct dentry *proc_tgid_net_lookup(struct inode *dir,
129 struct dentry *dentry, unsigned int flags)
130{
131 struct dentry *de;
132 struct net *net;
133
134 de = ERR_PTR(-ENOENT);
135 net = get_proc_task_net(dir);
136 if (net != NULL) {
137 de = proc_lookup_de(net->proc_net, dir, dentry);
138 put_net(net);
139 }
140 return de;
141}
142
143static int proc_tgid_net_getattr(struct vfsmount *mnt, struct dentry *dentry,
144 struct kstat *stat)
145{
146 struct inode *inode = d_inode(dentry);
147 struct net *net;
148
149 net = get_proc_task_net(inode);
150
151 generic_fillattr(inode, stat);
152
153 if (net != NULL) {
154 stat->nlink = net->proc_net->nlink;
155 put_net(net);
156 }
157
158 return 0;
159}
160
161const struct inode_operations proc_net_inode_operations = {
162 .lookup = proc_tgid_net_lookup,
163 .getattr = proc_tgid_net_getattr,
164};
165
166static int proc_tgid_net_readdir(struct file *file, struct dir_context *ctx)
167{
168 int ret;
169 struct net *net;
170
171 ret = -EINVAL;
172 net = get_proc_task_net(file_inode(file));
173 if (net != NULL) {
174 ret = proc_readdir_de(net->proc_net, file, ctx);
175 put_net(net);
176 }
177 return ret;
178}
179
180const struct file_operations proc_net_operations = {
181 .llseek = generic_file_llseek,
182 .read = generic_read_dir,
183 .iterate_shared = proc_tgid_net_readdir,
184};
185
186static __net_init int proc_net_ns_init(struct net *net)
187{
188 struct proc_dir_entry *netd, *net_statd;
189 kuid_t uid;
190 kgid_t gid;
191 int err;
192
193 err = -ENOMEM;
194 netd = kzalloc(sizeof(*netd) + 4, GFP_KERNEL);
195 if (!netd)
196 goto out;
197
198 netd->subdir = RB_ROOT;
199 netd->data = net;
200 netd->nlink = 2;
201 netd->namelen = 3;
202 netd->parent = &proc_root;
203 memcpy(netd->name, "net", 4);
204
205 uid = make_kuid(net->user_ns, 0);
206 if (!uid_valid(uid))
207 uid = netd->uid;
208
209 gid = make_kgid(net->user_ns, 0);
210 if (!gid_valid(gid))
211 gid = netd->gid;
212
213 proc_set_user(netd, uid, gid);
214
215 err = -EEXIST;
216 net_statd = proc_net_mkdir(net, "stat", netd);
217 if (!net_statd)
218 goto free_net;
219
220 net->proc_net = netd;
221 net->proc_net_stat = net_statd;
222 return 0;
223
224free_net:
225 kfree(netd);
226out:
227 return err;
228}
229
230static __net_exit void proc_net_ns_exit(struct net *net)
231{
232 remove_proc_entry("stat", net->proc_net);
233 kfree(net->proc_net);
234}
235
236static struct pernet_operations __net_initdata proc_net_ns_ops = {
237 .init = proc_net_ns_init,
238 .exit = proc_net_ns_exit,
239};
240
241int __init proc_net_init(void)
242{
243 proc_symlink("net", NULL, "self/net");
244
245 return register_pernet_subsys(&proc_net_ns_ops);
246}