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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#include <linux/errno.h>
12#include <linux/time.h>
13#include <linux/proc_fs.h>
14#include <linux/stat.h>
15#include <linux/slab.h>
16#include <linux/init.h>
17#include <linux/sched.h>
18#include <linux/sched/task.h>
19#include <linux/module.h>
20#include <linux/bitops.h>
21#include <linux/mount.h>
22#include <linux/nsproxy.h>
23#include <linux/uidgid.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
39static int seq_open_net(struct inode *inode, struct file *file)
40{
41 unsigned int state_size = PDE(inode)->state_size;
42 struct seq_net_private *p;
43 struct net *net;
44
45 WARN_ON_ONCE(state_size < sizeof(*p));
46
47 if (file->f_mode & FMODE_WRITE && !PDE(inode)->write)
48 return -EACCES;
49
50 net = get_proc_net(inode);
51 if (!net)
52 return -ENXIO;
53
54 p = __seq_open_private(file, PDE(inode)->seq_ops, state_size);
55 if (!p) {
56 put_net(net);
57 return -ENOMEM;
58 }
59#ifdef CONFIG_NET_NS
60 p->net = net;
61 netns_tracker_alloc(net, &p->ns_tracker, GFP_KERNEL);
62#endif
63 return 0;
64}
65
66static void seq_file_net_put_net(struct seq_file *seq)
67{
68#ifdef CONFIG_NET_NS
69 struct seq_net_private *priv = seq->private;
70
71 put_net_track(priv->net, &priv->ns_tracker);
72#else
73 put_net(&init_net);
74#endif
75}
76
77static int seq_release_net(struct inode *ino, struct file *f)
78{
79 struct seq_file *seq = f->private_data;
80
81 seq_file_net_put_net(seq);
82 seq_release_private(ino, f);
83 return 0;
84}
85
86static const struct proc_ops proc_net_seq_ops = {
87 .proc_open = seq_open_net,
88 .proc_read = seq_read,
89 .proc_write = proc_simple_write,
90 .proc_lseek = seq_lseek,
91 .proc_release = seq_release_net,
92};
93
94int bpf_iter_init_seq_net(void *priv_data, struct bpf_iter_aux_info *aux)
95{
96#ifdef CONFIG_NET_NS
97 struct seq_net_private *p = priv_data;
98
99 p->net = get_net_track(current->nsproxy->net_ns, &p->ns_tracker,
100 GFP_KERNEL);
101#endif
102 return 0;
103}
104
105void bpf_iter_fini_seq_net(void *priv_data)
106{
107#ifdef CONFIG_NET_NS
108 struct seq_net_private *p = priv_data;
109
110 put_net_track(p->net, &p->ns_tracker);
111#endif
112}
113
114struct proc_dir_entry *proc_create_net_data(const char *name, umode_t mode,
115 struct proc_dir_entry *parent, const struct seq_operations *ops,
116 unsigned int state_size, void *data)
117{
118 struct proc_dir_entry *p;
119
120 p = proc_create_reg(name, mode, &parent, data);
121 if (!p)
122 return NULL;
123 pde_force_lookup(p);
124 p->proc_ops = &proc_net_seq_ops;
125 p->seq_ops = ops;
126 p->state_size = state_size;
127 return proc_register(parent, p);
128}
129EXPORT_SYMBOL_GPL(proc_create_net_data);
130
131/**
132 * proc_create_net_data_write - Create a writable net_ns-specific proc file
133 * @name: The name of the file.
134 * @mode: The file's access mode.
135 * @parent: The parent directory in which to create.
136 * @ops: The seq_file ops with which to read the file.
137 * @write: The write method with which to 'modify' the file.
138 * @data: Data for retrieval by pde_data().
139 *
140 * Create a network namespaced proc file in the @parent directory with the
141 * specified @name and @mode that allows reading of a file that displays a
142 * series of elements and also provides for the file accepting writes that have
143 * some arbitrary effect.
144 *
145 * The functions in the @ops table are used to iterate over items to be
146 * presented and extract the readable content using the seq_file interface.
147 *
148 * The @write function is called with the data copied into a kernel space
149 * scratch buffer and has a NUL appended for convenience. The buffer may be
150 * modified by the @write function. @write should return 0 on success.
151 *
152 * The @data value is accessible from the @show and @write functions by calling
153 * pde_data() on the file inode. The network namespace must be accessed by
154 * calling seq_file_net() on the seq_file struct.
155 */
156struct proc_dir_entry *proc_create_net_data_write(const char *name, umode_t mode,
157 struct proc_dir_entry *parent,
158 const struct seq_operations *ops,
159 proc_write_t write,
160 unsigned int state_size, void *data)
161{
162 struct proc_dir_entry *p;
163
164 p = proc_create_reg(name, mode, &parent, data);
165 if (!p)
166 return NULL;
167 pde_force_lookup(p);
168 p->proc_ops = &proc_net_seq_ops;
169 p->seq_ops = ops;
170 p->state_size = state_size;
171 p->write = write;
172 return proc_register(parent, p);
173}
174EXPORT_SYMBOL_GPL(proc_create_net_data_write);
175
176static int single_open_net(struct inode *inode, struct file *file)
177{
178 struct proc_dir_entry *de = PDE(inode);
179 struct net *net;
180 int err;
181
182 net = get_proc_net(inode);
183 if (!net)
184 return -ENXIO;
185
186 err = single_open(file, de->single_show, net);
187 if (err)
188 put_net(net);
189 return err;
190}
191
192static int single_release_net(struct inode *ino, struct file *f)
193{
194 struct seq_file *seq = f->private_data;
195 put_net(seq->private);
196 return single_release(ino, f);
197}
198
199static const struct proc_ops proc_net_single_ops = {
200 .proc_open = single_open_net,
201 .proc_read = seq_read,
202 .proc_write = proc_simple_write,
203 .proc_lseek = seq_lseek,
204 .proc_release = single_release_net,
205};
206
207struct proc_dir_entry *proc_create_net_single(const char *name, umode_t mode,
208 struct proc_dir_entry *parent,
209 int (*show)(struct seq_file *, void *), void *data)
210{
211 struct proc_dir_entry *p;
212
213 p = proc_create_reg(name, mode, &parent, data);
214 if (!p)
215 return NULL;
216 pde_force_lookup(p);
217 p->proc_ops = &proc_net_single_ops;
218 p->single_show = show;
219 return proc_register(parent, p);
220}
221EXPORT_SYMBOL_GPL(proc_create_net_single);
222
223/**
224 * proc_create_net_single_write - Create a writable net_ns-specific proc file
225 * @name: The name of the file.
226 * @mode: The file's access mode.
227 * @parent: The parent directory in which to create.
228 * @show: The seqfile show method with which to read the file.
229 * @write: The write method with which to 'modify' the file.
230 * @data: Data for retrieval by pde_data().
231 *
232 * Create a network-namespaced proc file in the @parent directory with the
233 * specified @name and @mode that allows reading of a file that displays a
234 * single element rather than a series and also provides for the file accepting
235 * writes that have some arbitrary effect.
236 *
237 * The @show function is called to extract the readable content via the
238 * seq_file interface.
239 *
240 * The @write function is called with the data copied into a kernel space
241 * scratch buffer and has a NUL appended for convenience. The buffer may be
242 * modified by the @write function. @write should return 0 on success.
243 *
244 * The @data value is accessible from the @show and @write functions by calling
245 * pde_data() on the file inode. The network namespace must be accessed by
246 * calling seq_file_single_net() on the seq_file struct.
247 */
248struct proc_dir_entry *proc_create_net_single_write(const char *name, umode_t mode,
249 struct proc_dir_entry *parent,
250 int (*show)(struct seq_file *, void *),
251 proc_write_t write,
252 void *data)
253{
254 struct proc_dir_entry *p;
255
256 p = proc_create_reg(name, mode, &parent, data);
257 if (!p)
258 return NULL;
259 pde_force_lookup(p);
260 p->proc_ops = &proc_net_single_ops;
261 p->single_show = show;
262 p->write = write;
263 return proc_register(parent, p);
264}
265EXPORT_SYMBOL_GPL(proc_create_net_single_write);
266
267static struct net *get_proc_task_net(struct inode *dir)
268{
269 struct task_struct *task;
270 struct nsproxy *ns;
271 struct net *net = NULL;
272
273 rcu_read_lock();
274 task = pid_task(proc_pid(dir), PIDTYPE_PID);
275 if (task != NULL) {
276 task_lock(task);
277 ns = task->nsproxy;
278 if (ns != NULL)
279 net = get_net(ns->net_ns);
280 task_unlock(task);
281 }
282 rcu_read_unlock();
283
284 return net;
285}
286
287static struct dentry *proc_tgid_net_lookup(struct inode *dir,
288 struct dentry *dentry, unsigned int flags)
289{
290 struct dentry *de;
291 struct net *net;
292
293 de = ERR_PTR(-ENOENT);
294 net = get_proc_task_net(dir);
295 if (net != NULL) {
296 de = proc_lookup_de(dir, dentry, net->proc_net);
297 put_net(net);
298 }
299 return de;
300}
301
302static int proc_tgid_net_getattr(struct mnt_idmap *idmap,
303 const struct path *path, struct kstat *stat,
304 u32 request_mask, unsigned int query_flags)
305{
306 struct inode *inode = d_inode(path->dentry);
307 struct net *net;
308
309 net = get_proc_task_net(inode);
310
311 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
312
313 if (net != NULL) {
314 stat->nlink = net->proc_net->nlink;
315 put_net(net);
316 }
317
318 return 0;
319}
320
321const struct inode_operations proc_net_inode_operations = {
322 .lookup = proc_tgid_net_lookup,
323 .getattr = proc_tgid_net_getattr,
324 .setattr = proc_setattr,
325};
326
327static int proc_tgid_net_readdir(struct file *file, struct dir_context *ctx)
328{
329 int ret;
330 struct net *net;
331
332 ret = -EINVAL;
333 net = get_proc_task_net(file_inode(file));
334 if (net != NULL) {
335 ret = proc_readdir_de(file, ctx, net->proc_net);
336 put_net(net);
337 }
338 return ret;
339}
340
341const struct file_operations proc_net_operations = {
342 .llseek = generic_file_llseek,
343 .read = generic_read_dir,
344 .iterate_shared = proc_tgid_net_readdir,
345};
346
347static __net_init int proc_net_ns_init(struct net *net)
348{
349 struct proc_dir_entry *netd, *net_statd;
350 kuid_t uid;
351 kgid_t gid;
352 int err;
353
354 /*
355 * This PDE acts only as an anchor for /proc/${pid}/net hierarchy.
356 * Corresponding inode (PDE(inode) == net->proc_net) is never
357 * instantiated therefore blanket zeroing is fine.
358 * net->proc_net_stat inode is instantiated normally.
359 */
360 err = -ENOMEM;
361 netd = kmem_cache_zalloc(proc_dir_entry_cache, GFP_KERNEL);
362 if (!netd)
363 goto out;
364
365 netd->subdir = RB_ROOT;
366 netd->data = net;
367 netd->nlink = 2;
368 netd->namelen = 3;
369 netd->parent = &proc_root;
370 netd->name = netd->inline_name;
371 memcpy(netd->name, "net", 4);
372
373 uid = make_kuid(net->user_ns, 0);
374 if (!uid_valid(uid))
375 uid = netd->uid;
376
377 gid = make_kgid(net->user_ns, 0);
378 if (!gid_valid(gid))
379 gid = netd->gid;
380
381 proc_set_user(netd, uid, gid);
382
383 /* Seed dentry revalidation for /proc/${pid}/net */
384 pde_force_lookup(netd);
385
386 err = -EEXIST;
387 net_statd = proc_net_mkdir(net, "stat", netd);
388 if (!net_statd)
389 goto free_net;
390
391 net->proc_net = netd;
392 net->proc_net_stat = net_statd;
393 return 0;
394
395free_net:
396 pde_free(netd);
397out:
398 return err;
399}
400
401static __net_exit void proc_net_ns_exit(struct net *net)
402{
403 remove_proc_entry("stat", net->proc_net);
404 pde_free(net->proc_net);
405}
406
407static struct pernet_operations __net_initdata proc_net_ns_ops = {
408 .init = proc_net_ns_init,
409 .exit = proc_net_ns_exit,
410};
411
412int __init proc_net_init(void)
413{
414 proc_symlink("net", NULL, "self/net");
415
416 return register_pernet_subsys(&proc_net_ns_ops);
417}
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(dir, dentry, net->proc_net);
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(file, ctx, net->proc_net);
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 = kmem_cache_zalloc(proc_dir_entry_cache, 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 netd->name = netd->inline_name;
205 memcpy(netd->name, "net", 4);
206
207 uid = make_kuid(net->user_ns, 0);
208 if (!uid_valid(uid))
209 uid = netd->uid;
210
211 gid = make_kgid(net->user_ns, 0);
212 if (!gid_valid(gid))
213 gid = netd->gid;
214
215 proc_set_user(netd, uid, gid);
216
217 err = -EEXIST;
218 net_statd = proc_net_mkdir(net, "stat", netd);
219 if (!net_statd)
220 goto free_net;
221
222 net->proc_net = netd;
223 net->proc_net_stat = net_statd;
224 return 0;
225
226free_net:
227 pde_free(netd);
228out:
229 return err;
230}
231
232static __net_exit void proc_net_ns_exit(struct net *net)
233{
234 remove_proc_entry("stat", net->proc_net);
235 pde_free(net->proc_net);
236}
237
238static struct pernet_operations __net_initdata proc_net_ns_ops = {
239 .init = proc_net_ns_init,
240 .exit = proc_net_ns_exit,
241};
242
243int __init proc_net_init(void)
244{
245 proc_symlink("net", NULL, "self/net");
246
247 return register_pernet_subsys(&proc_net_ns_ops);
248}