1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* inode.c: /proc/openprom handling routines |
3 | * |
4 | * Copyright (C) 1996-1999 Jakub Jelinek (jakub@redhat.com) |
5 | * Copyright (C) 1998 Eddie C. Dost (ecd@skynet.be) |
6 | */ |
7 | |
8 | #include <linux/module.h> |
9 | #include <linux/types.h> |
10 | #include <linux/string.h> |
11 | #include <linux/fs.h> |
12 | #include <linux/fs_context.h> |
13 | #include <linux/init.h> |
14 | #include <linux/slab.h> |
15 | #include <linux/seq_file.h> |
16 | #include <linux/magic.h> |
17 | |
18 | #include <asm/openprom.h> |
19 | #include <asm/oplib.h> |
20 | #include <asm/prom.h> |
21 | #include <linux/uaccess.h> |
22 | |
23 | static DEFINE_MUTEX(op_mutex); |
24 | |
25 | #define OPENPROM_ROOT_INO 0 |
26 | |
27 | enum op_inode_type { |
28 | op_inode_node, |
29 | op_inode_prop, |
30 | }; |
31 | |
32 | union op_inode_data { |
33 | struct device_node *node; |
34 | struct property *prop; |
35 | }; |
36 | |
37 | struct op_inode_info { |
38 | struct inode vfs_inode; |
39 | enum op_inode_type type; |
40 | union op_inode_data u; |
41 | }; |
42 | |
43 | static struct inode *openprom_iget(struct super_block *sb, ino_t ino); |
44 | |
45 | static inline struct op_inode_info *OP_I(struct inode *inode) |
46 | { |
47 | return container_of(inode, struct op_inode_info, vfs_inode); |
48 | } |
49 | |
50 | static int is_string(unsigned char *p, int len) |
51 | { |
52 | int i; |
53 | |
54 | for (i = 0; i < len; i++) { |
55 | unsigned char val = p[i]; |
56 | |
57 | if ((i && !val) || |
58 | (val >= ' ' && val <= '~')) |
59 | continue; |
60 | |
61 | return 0; |
62 | } |
63 | |
64 | return 1; |
65 | } |
66 | |
67 | static int property_show(struct seq_file *f, void *v) |
68 | { |
69 | struct property *prop = f->private; |
70 | void *pval; |
71 | int len; |
72 | |
73 | len = prop->length; |
74 | pval = prop->value; |
75 | |
76 | if (is_string(p: pval, len)) { |
77 | while (len > 0) { |
78 | int n = strlen(pval); |
79 | |
80 | seq_printf(m: f, fmt: "%s" , (char *) pval); |
81 | |
82 | /* Skip over the NULL byte too. */ |
83 | pval += n + 1; |
84 | len -= n + 1; |
85 | |
86 | if (len > 0) |
87 | seq_printf(m: f, fmt: " + " ); |
88 | } |
89 | } else { |
90 | if (len & 3) { |
91 | while (len) { |
92 | len--; |
93 | if (len) |
94 | seq_printf(m: f, fmt: "%02x." , |
95 | *(unsigned char *) pval); |
96 | else |
97 | seq_printf(m: f, fmt: "%02x" , |
98 | *(unsigned char *) pval); |
99 | pval++; |
100 | } |
101 | } else { |
102 | while (len >= 4) { |
103 | len -= 4; |
104 | |
105 | if (len) |
106 | seq_printf(m: f, fmt: "%08x." , |
107 | *(unsigned int *) pval); |
108 | else |
109 | seq_printf(m: f, fmt: "%08x" , |
110 | *(unsigned int *) pval); |
111 | pval += 4; |
112 | } |
113 | } |
114 | } |
115 | seq_printf(m: f, fmt: "\n" ); |
116 | |
117 | return 0; |
118 | } |
119 | |
120 | static void *property_start(struct seq_file *f, loff_t *pos) |
121 | { |
122 | if (*pos == 0) |
123 | return pos; |
124 | return NULL; |
125 | } |
126 | |
127 | static void *property_next(struct seq_file *f, void *v, loff_t *pos) |
128 | { |
129 | (*pos)++; |
130 | return NULL; |
131 | } |
132 | |
133 | static void property_stop(struct seq_file *f, void *v) |
134 | { |
135 | /* Nothing to do */ |
136 | } |
137 | |
138 | static const struct seq_operations property_op = { |
139 | .start = property_start, |
140 | .next = property_next, |
141 | .stop = property_stop, |
142 | .show = property_show |
143 | }; |
144 | |
145 | static int property_open(struct inode *inode, struct file *file) |
146 | { |
147 | struct op_inode_info *oi = OP_I(inode); |
148 | int ret; |
149 | |
150 | BUG_ON(oi->type != op_inode_prop); |
151 | |
152 | ret = seq_open(file, &property_op); |
153 | if (!ret) { |
154 | struct seq_file *m = file->private_data; |
155 | m->private = oi->u.prop; |
156 | } |
157 | return ret; |
158 | } |
159 | |
160 | static const struct file_operations openpromfs_prop_ops = { |
161 | .open = property_open, |
162 | .read = seq_read, |
163 | .llseek = seq_lseek, |
164 | .release = seq_release, |
165 | }; |
166 | |
167 | static int openpromfs_readdir(struct file *, struct dir_context *); |
168 | |
169 | static const struct file_operations openprom_operations = { |
170 | .read = generic_read_dir, |
171 | .iterate_shared = openpromfs_readdir, |
172 | .llseek = generic_file_llseek, |
173 | }; |
174 | |
175 | static struct dentry *openpromfs_lookup(struct inode *, struct dentry *, unsigned int); |
176 | |
177 | static const struct inode_operations openprom_inode_operations = { |
178 | .lookup = openpromfs_lookup, |
179 | }; |
180 | |
181 | static struct dentry *openpromfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) |
182 | { |
183 | struct op_inode_info *ent_oi, *oi = OP_I(inode: dir); |
184 | struct device_node *dp, *child; |
185 | struct property *prop; |
186 | enum op_inode_type ent_type; |
187 | union op_inode_data ent_data; |
188 | const char *name; |
189 | struct inode *inode; |
190 | unsigned int ino; |
191 | int len; |
192 | |
193 | BUG_ON(oi->type != op_inode_node); |
194 | |
195 | dp = oi->u.node; |
196 | |
197 | name = dentry->d_name.name; |
198 | len = dentry->d_name.len; |
199 | |
200 | mutex_lock(&op_mutex); |
201 | |
202 | child = dp->child; |
203 | while (child) { |
204 | const char *node_name = kbasename(path: child->full_name); |
205 | int n = strlen(node_name); |
206 | |
207 | if (len == n && |
208 | !strncmp(node_name, name, len)) { |
209 | ent_type = op_inode_node; |
210 | ent_data.node = child; |
211 | ino = child->unique_id; |
212 | goto found; |
213 | } |
214 | child = child->sibling; |
215 | } |
216 | |
217 | prop = dp->properties; |
218 | while (prop) { |
219 | int n = strlen(prop->name); |
220 | |
221 | if (len == n && !strncmp(prop->name, name, len)) { |
222 | ent_type = op_inode_prop; |
223 | ent_data.prop = prop; |
224 | ino = prop->unique_id; |
225 | goto found; |
226 | } |
227 | |
228 | prop = prop->next; |
229 | } |
230 | |
231 | mutex_unlock(lock: &op_mutex); |
232 | return ERR_PTR(error: -ENOENT); |
233 | |
234 | found: |
235 | inode = openprom_iget(sb: dir->i_sb, ino); |
236 | mutex_unlock(lock: &op_mutex); |
237 | if (IS_ERR(ptr: inode)) |
238 | return ERR_CAST(ptr: inode); |
239 | if (inode->i_state & I_NEW) { |
240 | simple_inode_init_ts(inode); |
241 | ent_oi = OP_I(inode); |
242 | ent_oi->type = ent_type; |
243 | ent_oi->u = ent_data; |
244 | |
245 | switch (ent_type) { |
246 | case op_inode_node: |
247 | inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO; |
248 | inode->i_op = &openprom_inode_operations; |
249 | inode->i_fop = &openprom_operations; |
250 | set_nlink(inode, nlink: 2); |
251 | break; |
252 | case op_inode_prop: |
253 | if (of_node_name_eq(np: dp, name: "options" ) && (len == 17) && |
254 | !strncmp (name, "security-password" , 17)) |
255 | inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; |
256 | else |
257 | inode->i_mode = S_IFREG | S_IRUGO; |
258 | inode->i_fop = &openpromfs_prop_ops; |
259 | set_nlink(inode, nlink: 1); |
260 | inode->i_size = ent_oi->u.prop->length; |
261 | break; |
262 | } |
263 | unlock_new_inode(inode); |
264 | } |
265 | |
266 | return d_splice_alias(inode, dentry); |
267 | } |
268 | |
269 | static int openpromfs_readdir(struct file *file, struct dir_context *ctx) |
270 | { |
271 | struct inode *inode = file_inode(f: file); |
272 | struct op_inode_info *oi = OP_I(inode); |
273 | struct device_node *dp = oi->u.node; |
274 | struct device_node *child; |
275 | struct property *prop; |
276 | int i; |
277 | |
278 | mutex_lock(&op_mutex); |
279 | |
280 | if (ctx->pos == 0) { |
281 | if (!dir_emit(ctx, name: "." , namelen: 1, ino: inode->i_ino, DT_DIR)) |
282 | goto out; |
283 | ctx->pos = 1; |
284 | } |
285 | if (ctx->pos == 1) { |
286 | if (!dir_emit(ctx, name: ".." , namelen: 2, |
287 | ino: (dp->parent == NULL ? |
288 | OPENPROM_ROOT_INO : |
289 | dp->parent->unique_id), DT_DIR)) |
290 | goto out; |
291 | ctx->pos = 2; |
292 | } |
293 | i = ctx->pos - 2; |
294 | |
295 | /* First, the children nodes as directories. */ |
296 | child = dp->child; |
297 | while (i && child) { |
298 | child = child->sibling; |
299 | i--; |
300 | } |
301 | while (child) { |
302 | if (!dir_emit(ctx, |
303 | name: kbasename(path: child->full_name), |
304 | strlen(kbasename(child->full_name)), |
305 | ino: child->unique_id, DT_DIR)) |
306 | goto out; |
307 | |
308 | ctx->pos++; |
309 | child = child->sibling; |
310 | } |
311 | |
312 | /* Next, the properties as files. */ |
313 | prop = dp->properties; |
314 | while (i && prop) { |
315 | prop = prop->next; |
316 | i--; |
317 | } |
318 | while (prop) { |
319 | if (!dir_emit(ctx, name: prop->name, strlen(prop->name), |
320 | ino: prop->unique_id, DT_REG)) |
321 | goto out; |
322 | |
323 | ctx->pos++; |
324 | prop = prop->next; |
325 | } |
326 | |
327 | out: |
328 | mutex_unlock(lock: &op_mutex); |
329 | return 0; |
330 | } |
331 | |
332 | static struct kmem_cache *op_inode_cachep; |
333 | |
334 | static struct inode *openprom_alloc_inode(struct super_block *sb) |
335 | { |
336 | struct op_inode_info *oi; |
337 | |
338 | oi = alloc_inode_sb(sb, cache: op_inode_cachep, GFP_KERNEL); |
339 | if (!oi) |
340 | return NULL; |
341 | |
342 | return &oi->vfs_inode; |
343 | } |
344 | |
345 | static void openprom_free_inode(struct inode *inode) |
346 | { |
347 | kmem_cache_free(s: op_inode_cachep, objp: OP_I(inode)); |
348 | } |
349 | |
350 | static struct inode *openprom_iget(struct super_block *sb, ino_t ino) |
351 | { |
352 | struct inode *inode = iget_locked(sb, ino); |
353 | if (!inode) |
354 | inode = ERR_PTR(error: -ENOMEM); |
355 | return inode; |
356 | } |
357 | |
358 | static int openprom_remount(struct super_block *sb, int *flags, char *data) |
359 | { |
360 | sync_filesystem(sb); |
361 | *flags |= SB_NOATIME; |
362 | return 0; |
363 | } |
364 | |
365 | static const struct super_operations openprom_sops = { |
366 | .alloc_inode = openprom_alloc_inode, |
367 | .free_inode = openprom_free_inode, |
368 | .statfs = simple_statfs, |
369 | .remount_fs = openprom_remount, |
370 | }; |
371 | |
372 | static int openprom_fill_super(struct super_block *s, struct fs_context *fc) |
373 | { |
374 | struct inode *root_inode; |
375 | struct op_inode_info *oi; |
376 | int ret; |
377 | |
378 | s->s_flags |= SB_NOATIME; |
379 | s->s_blocksize = 1024; |
380 | s->s_blocksize_bits = 10; |
381 | s->s_magic = OPENPROM_SUPER_MAGIC; |
382 | s->s_op = &openprom_sops; |
383 | s->s_time_gran = 1; |
384 | root_inode = openprom_iget(sb: s, OPENPROM_ROOT_INO); |
385 | if (IS_ERR(ptr: root_inode)) { |
386 | ret = PTR_ERR(ptr: root_inode); |
387 | goto out_no_root; |
388 | } |
389 | |
390 | simple_inode_init_ts(inode: root_inode); |
391 | root_inode->i_op = &openprom_inode_operations; |
392 | root_inode->i_fop = &openprom_operations; |
393 | root_inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO; |
394 | oi = OP_I(inode: root_inode); |
395 | oi->type = op_inode_node; |
396 | oi->u.node = of_find_node_by_path(path: "/" ); |
397 | unlock_new_inode(root_inode); |
398 | |
399 | s->s_root = d_make_root(root_inode); |
400 | if (!s->s_root) |
401 | goto out_no_root_dentry; |
402 | return 0; |
403 | |
404 | out_no_root_dentry: |
405 | ret = -ENOMEM; |
406 | out_no_root: |
407 | printk("openprom_fill_super: get root inode failed\n" ); |
408 | return ret; |
409 | } |
410 | |
411 | static int openpromfs_get_tree(struct fs_context *fc) |
412 | { |
413 | return get_tree_single(fc, fill_super: openprom_fill_super); |
414 | } |
415 | |
416 | static const struct fs_context_operations openpromfs_context_ops = { |
417 | .get_tree = openpromfs_get_tree, |
418 | }; |
419 | |
420 | static int openpromfs_init_fs_context(struct fs_context *fc) |
421 | { |
422 | fc->ops = &openpromfs_context_ops; |
423 | return 0; |
424 | } |
425 | |
426 | static struct file_system_type openprom_fs_type = { |
427 | .owner = THIS_MODULE, |
428 | .name = "openpromfs" , |
429 | .init_fs_context = openpromfs_init_fs_context, |
430 | .kill_sb = kill_anon_super, |
431 | }; |
432 | MODULE_ALIAS_FS("openpromfs" ); |
433 | |
434 | static void op_inode_init_once(void *data) |
435 | { |
436 | struct op_inode_info *oi = (struct op_inode_info *) data; |
437 | |
438 | inode_init_once(&oi->vfs_inode); |
439 | } |
440 | |
441 | static int __init init_openprom_fs(void) |
442 | { |
443 | int err; |
444 | |
445 | op_inode_cachep = kmem_cache_create(name: "op_inode_cache" , |
446 | size: sizeof(struct op_inode_info), |
447 | align: 0, |
448 | flags: (SLAB_RECLAIM_ACCOUNT | |
449 | SLAB_MEM_SPREAD | SLAB_ACCOUNT), |
450 | ctor: op_inode_init_once); |
451 | if (!op_inode_cachep) |
452 | return -ENOMEM; |
453 | |
454 | err = register_filesystem(&openprom_fs_type); |
455 | if (err) |
456 | kmem_cache_destroy(s: op_inode_cachep); |
457 | |
458 | return err; |
459 | } |
460 | |
461 | static void __exit exit_openprom_fs(void) |
462 | { |
463 | unregister_filesystem(&openprom_fs_type); |
464 | /* |
465 | * Make sure all delayed rcu free inodes are flushed before we |
466 | * destroy cache. |
467 | */ |
468 | rcu_barrier(); |
469 | kmem_cache_destroy(s: op_inode_cachep); |
470 | } |
471 | |
472 | module_init(init_openprom_fs) |
473 | module_exit(exit_openprom_fs) |
474 | MODULE_LICENSE("GPL" ); |
475 | |