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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
3c12afe7 DM |
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 | */ | |
3c12afe7 DM |
11 | #include <linux/errno.h> |
12 | #include <linux/time.h> | |
13 | #include <linux/proc_fs.h> | |
14 | #include <linux/stat.h> | |
5a0e3ad6 | 15 | #include <linux/slab.h> |
3c12afe7 DM |
16 | #include <linux/init.h> |
17 | #include <linux/sched.h> | |
f719ff9b | 18 | #include <linux/sched/task.h> |
3c12afe7 DM |
19 | #include <linux/module.h> |
20 | #include <linux/bitops.h> | |
3c12afe7 DM |
21 | #include <linux/mount.h> |
22 | #include <linux/nsproxy.h> | |
c110486f | 23 | #include <linux/uidgid.h> |
3c12afe7 | 24 | #include <net/net_namespace.h> |
e372c414 | 25 | #include <linux/seq_file.h> |
3c12afe7 DM |
26 | |
27 | #include "internal.h" | |
28 | ||
4abfd029 DH |
29 | static inline struct net *PDE_NET(struct proc_dir_entry *pde) |
30 | { | |
31 | return pde->parent->data; | |
32 | } | |
3c12afe7 | 33 | |
8086cd45 AB |
34 | static struct net *get_proc_net(const struct inode *inode) |
35 | { | |
36 | return maybe_get_net(PDE_NET(PDE(inode))); | |
37 | } | |
38 | ||
c3506372 | 39 | static int seq_open_net(struct inode *inode, struct file *file) |
e372c414 | 40 | { |
c3506372 | 41 | unsigned int state_size = PDE(inode)->state_size; |
e372c414 | 42 | struct seq_net_private *p; |
c3506372 | 43 | struct net *net; |
e372c414 | 44 | |
c3506372 | 45 | WARN_ON_ONCE(state_size < sizeof(*p)); |
e372c414 | 46 | |
564def71 DH |
47 | if (file->f_mode & FMODE_WRITE && !PDE(inode)->write) |
48 | return -EACCES; | |
49 | ||
c3506372 CH |
50 | net = get_proc_net(inode); |
51 | if (!net) | |
e372c414 DL |
52 | return -ENXIO; |
53 | ||
c3506372 CH |
54 | p = __seq_open_private(file, PDE(inode)->seq_ops, state_size); |
55 | if (!p) { | |
e372c414 DL |
56 | put_net(net); |
57 | return -ENOMEM; | |
58 | } | |
1218854a | 59 | #ifdef CONFIG_NET_NS |
e372c414 | 60 | p->net = net; |
04a931e5 | 61 | netns_tracker_alloc(net, &p->ns_tracker, GFP_KERNEL); |
1218854a | 62 | #endif |
e372c414 DL |
63 | return 0; |
64 | } | |
c3506372 | 65 | |
04a931e5 ED |
66 | static 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 | ||
c3506372 CH |
77 | static int seq_release_net(struct inode *ino, struct file *f) |
78 | { | |
79 | struct seq_file *seq = f->private_data; | |
80 | ||
04a931e5 | 81 | seq_file_net_put_net(seq); |
c3506372 CH |
82 | seq_release_private(ino, f); |
83 | return 0; | |
84 | } | |
85 | ||
d56c0d45 AD |
86 | static 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, | |
c3506372 CH |
92 | }; |
93 | ||
f9c79272 | 94 | int bpf_iter_init_seq_net(void *priv_data, struct bpf_iter_aux_info *aux) |
138d0be3 YS |
95 | { |
96 | #ifdef CONFIG_NET_NS | |
97 | struct seq_net_private *p = priv_data; | |
98 | ||
04a931e5 ED |
99 | p->net = get_net_track(current->nsproxy->net_ns, &p->ns_tracker, |
100 | GFP_KERNEL); | |
138d0be3 YS |
101 | #endif |
102 | return 0; | |
103 | } | |
104 | ||
105 | void bpf_iter_fini_seq_net(void *priv_data) | |
106 | { | |
107 | #ifdef CONFIG_NET_NS | |
108 | struct seq_net_private *p = priv_data; | |
109 | ||
04a931e5 | 110 | put_net_track(p->net, &p->ns_tracker); |
138d0be3 YS |
111 | #endif |
112 | } | |
113 | ||
c3506372 CH |
114 | struct 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; | |
1fde6f21 | 123 | pde_force_lookup(p); |
d56c0d45 | 124 | p->proc_ops = &proc_net_seq_ops; |
c3506372 CH |
125 | p->seq_ops = ops; |
126 | p->state_size = state_size; | |
127 | return proc_register(parent, p); | |
128 | } | |
129 | EXPORT_SYMBOL_GPL(proc_create_net_data); | |
e372c414 | 130 | |
564def71 DH |
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. | |
d2928e85 | 137 | * @write: The write method with which to 'modify' the file. |
359745d7 | 138 | * @data: Data for retrieval by pde_data(). |
564def71 DH |
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 | |
359745d7 | 153 | * pde_data() on the file inode. The network namespace must be accessed by |
564def71 DH |
154 | * calling seq_file_net() on the seq_file struct. |
155 | */ | |
156 | struct 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; | |
1fde6f21 | 167 | pde_force_lookup(p); |
d56c0d45 | 168 | p->proc_ops = &proc_net_seq_ops; |
564def71 DH |
169 | p->seq_ops = ops; |
170 | p->state_size = state_size; | |
171 | p->write = write; | |
172 | return proc_register(parent, p); | |
173 | } | |
174 | EXPORT_SYMBOL_GPL(proc_create_net_data_write); | |
175 | ||
3617d949 | 176 | static int single_open_net(struct inode *inode, struct file *file) |
de05c557 | 177 | { |
3617d949 | 178 | struct proc_dir_entry *de = PDE(inode); |
de05c557 | 179 | struct net *net; |
3617d949 | 180 | int err; |
de05c557 | 181 | |
de05c557 | 182 | net = get_proc_net(inode); |
3617d949 CH |
183 | if (!net) |
184 | return -ENXIO; | |
de05c557 | 185 | |
3617d949 CH |
186 | err = single_open(file, de->single_show, net); |
187 | if (err) | |
188 | put_net(net); | |
de05c557 PE |
189 | return err; |
190 | } | |
de05c557 | 191 | |
3617d949 | 192 | static int single_release_net(struct inode *ino, struct file *f) |
b6fcbdb4 PE |
193 | { |
194 | struct seq_file *seq = f->private_data; | |
195 | put_net(seq->private); | |
196 | return single_release(ino, f); | |
197 | } | |
3617d949 | 198 | |
d56c0d45 AD |
199 | static 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, | |
3617d949 CH |
205 | }; |
206 | ||
207 | struct 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; | |
1fde6f21 | 216 | pde_force_lookup(p); |
d56c0d45 | 217 | p->proc_ops = &proc_net_single_ops; |
3617d949 CH |
218 | p->single_show = show; |
219 | return proc_register(parent, p); | |
220 | } | |
221 | EXPORT_SYMBOL_GPL(proc_create_net_single); | |
b6fcbdb4 | 222 | |
564def71 DH |
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. | |
d2928e85 | 229 | * @write: The write method with which to 'modify' the file. |
359745d7 | 230 | * @data: Data for retrieval by pde_data(). |
564def71 DH |
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 | |
359745d7 | 245 | * pde_data() on the file inode. The network namespace must be accessed by |
564def71 DH |
246 | * calling seq_file_single_net() on the seq_file struct. |
247 | */ | |
248 | struct 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; | |
1fde6f21 | 259 | pde_force_lookup(p); |
d56c0d45 | 260 | p->proc_ops = &proc_net_single_ops; |
564def71 DH |
261 | p->single_show = show; |
262 | p->write = write; | |
263 | return proc_register(parent, p); | |
264 | } | |
265 | EXPORT_SYMBOL_GPL(proc_create_net_single_write); | |
266 | ||
e9720acd PE |
267 | static 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) { | |
728dba3a EB |
276 | task_lock(task); |
277 | ns = task->nsproxy; | |
e9720acd PE |
278 | if (ns != NULL) |
279 | net = get_net(ns->net_ns); | |
728dba3a | 280 | task_unlock(task); |
e9720acd PE |
281 | } |
282 | rcu_read_unlock(); | |
283 | ||
284 | return net; | |
285 | } | |
286 | ||
287 | static struct dentry *proc_tgid_net_lookup(struct inode *dir, | |
00cd8dd3 | 288 | struct dentry *dentry, unsigned int flags) |
e9720acd PE |
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) { | |
93ad5bc6 | 296 | de = proc_lookup_de(dir, dentry, net->proc_net); |
e9720acd PE |
297 | put_net(net); |
298 | } | |
299 | return de; | |
300 | } | |
301 | ||
b74d24f7 | 302 | static int proc_tgid_net_getattr(struct mnt_idmap *idmap, |
549c7297 | 303 | const struct path *path, struct kstat *stat, |
a528d35e | 304 | u32 request_mask, unsigned int query_flags) |
e9720acd | 305 | { |
a528d35e | 306 | struct inode *inode = d_inode(path->dentry); |
e9720acd PE |
307 | struct net *net; |
308 | ||
309 | net = get_proc_task_net(inode); | |
310 | ||
b74d24f7 | 311 | generic_fillattr(&nop_mnt_idmap, inode, stat); |
e9720acd PE |
312 | |
313 | if (net != NULL) { | |
314 | stat->nlink = net->proc_net->nlink; | |
315 | put_net(net); | |
316 | } | |
317 | ||
318 | return 0; | |
319 | } | |
320 | ||
321 | const struct inode_operations proc_net_inode_operations = { | |
322 | .lookup = proc_tgid_net_lookup, | |
323 | .getattr = proc_tgid_net_getattr, | |
324 | }; | |
325 | ||
f0c3b509 | 326 | static int proc_tgid_net_readdir(struct file *file, struct dir_context *ctx) |
e9720acd PE |
327 | { |
328 | int ret; | |
329 | struct net *net; | |
330 | ||
331 | ret = -EINVAL; | |
f0c3b509 | 332 | net = get_proc_task_net(file_inode(file)); |
e9720acd | 333 | if (net != NULL) { |
93ad5bc6 | 334 | ret = proc_readdir_de(file, ctx, net->proc_net); |
e9720acd PE |
335 | put_net(net); |
336 | } | |
337 | return ret; | |
338 | } | |
339 | ||
340 | const struct file_operations proc_net_operations = { | |
b4df2b92 | 341 | .llseek = generic_file_llseek, |
e9720acd | 342 | .read = generic_read_dir, |
f50752ea | 343 | .iterate_shared = proc_tgid_net_readdir, |
e9720acd PE |
344 | }; |
345 | ||
4665079c | 346 | static __net_init int proc_net_ns_init(struct net *net) |
3c12afe7 | 347 | { |
e9720acd | 348 | struct proc_dir_entry *netd, *net_statd; |
c110486f DT |
349 | kuid_t uid; |
350 | kgid_t gid; | |
3c12afe7 DM |
351 | int err; |
352 | ||
ed8fb78d AD |
353 | /* |
354 | * This PDE acts only as an anchor for /proc/${pid}/net hierarchy. | |
355 | * Corresponding inode (PDE(inode) == net->proc_net) is never | |
356 | * instantiated therefore blanket zeroing is fine. | |
357 | * net->proc_net_stat inode is instantiated normally. | |
358 | */ | |
3c12afe7 | 359 | err = -ENOMEM; |
b4884f23 | 360 | netd = kmem_cache_zalloc(proc_dir_entry_cache, GFP_KERNEL); |
e9720acd | 361 | if (!netd) |
3c12afe7 DM |
362 | goto out; |
363 | ||
4f113437 | 364 | netd->subdir = RB_ROOT; |
e9720acd PE |
365 | netd->data = net; |
366 | netd->nlink = 2; | |
e9720acd PE |
367 | netd->namelen = 3; |
368 | netd->parent = &proc_root; | |
b4884f23 | 369 | netd->name = netd->inline_name; |
09570f91 | 370 | memcpy(netd->name, "net", 4); |
3c12afe7 | 371 | |
c110486f DT |
372 | uid = make_kuid(net->user_ns, 0); |
373 | if (!uid_valid(uid)) | |
374 | uid = netd->uid; | |
375 | ||
376 | gid = make_kgid(net->user_ns, 0); | |
377 | if (!gid_valid(gid)) | |
378 | gid = netd->gid; | |
379 | ||
380 | proc_set_user(netd, uid, gid); | |
381 | ||
70551977 AD |
382 | /* Seed dentry revalidation for /proc/${pid}/net */ |
383 | pde_force_lookup(netd); | |
384 | ||
3c12afe7 | 385 | err = -EEXIST; |
e5d69b9f | 386 | net_statd = proc_net_mkdir(net, "stat", netd); |
3c12afe7 DM |
387 | if (!net_statd) |
388 | goto free_net; | |
389 | ||
3c12afe7 DM |
390 | net->proc_net = netd; |
391 | net->proc_net_stat = net_statd; | |
e9720acd | 392 | return 0; |
3c12afe7 | 393 | |
e9720acd | 394 | free_net: |
b4884f23 | 395 | pde_free(netd); |
3c12afe7 DM |
396 | out: |
397 | return err; | |
3c12afe7 DM |
398 | } |
399 | ||
4665079c | 400 | static __net_exit void proc_net_ns_exit(struct net *net) |
3c12afe7 DM |
401 | { |
402 | remove_proc_entry("stat", net->proc_net); | |
b4884f23 | 403 | pde_free(net->proc_net); |
3c12afe7 DM |
404 | } |
405 | ||
022cbae6 | 406 | static struct pernet_operations __net_initdata proc_net_ns_ops = { |
3c12afe7 DM |
407 | .init = proc_net_ns_init, |
408 | .exit = proc_net_ns_exit, | |
409 | }; | |
410 | ||
4665079c | 411 | int __init proc_net_init(void) |
3c12afe7 | 412 | { |
155134fe | 413 | proc_symlink("net", NULL, "self/net"); |
3c12afe7 DM |
414 | |
415 | return register_pernet_subsys(&proc_net_ns_ops); | |
416 | } |