xref: /linux/fs/afs/proc.c (revision ca64d84e93762f4e587e040a44ad9f6089afc777)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* /proc interface for AFS
3  *
4  * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
5  * Written by David Howells (dhowells@redhat.com)
6  */
7 
8 #include <linux/slab.h>
9 #include <linux/module.h>
10 #include <linux/proc_fs.h>
11 #include <linux/seq_file.h>
12 #include <linux/sched.h>
13 #include <linux/uaccess.h>
14 #include "internal.h"
15 
16 struct afs_vl_seq_net_private {
17 	struct seq_net_private		seq;	/* Must be first */
18 	struct afs_vlserver_list	*vllist;
19 };
20 
21 static inline struct afs_net *afs_seq2net(struct seq_file *m)
22 {
23 	return afs_net(seq_file_net(m));
24 }
25 
26 static inline struct afs_net *afs_seq2net_single(struct seq_file *m)
27 {
28 	return afs_net(seq_file_single_net(m));
29 }
30 
31 /*
32  * Display the list of cells known to the namespace.
33  */
34 static int afs_proc_cells_show(struct seq_file *m, void *v)
35 {
36 	struct afs_vlserver_list *vllist;
37 	struct afs_cell *cell;
38 
39 	if (v == SEQ_START_TOKEN) {
40 		/* display header on line 1 */
41 		seq_puts(m, "USE    TTL SV NAME\n");
42 		return 0;
43 	}
44 
45 	cell = list_entry(v, struct afs_cell, proc_link);
46 	vllist = rcu_dereference(cell->vl_servers);
47 
48 	/* display one cell per line on subsequent lines */
49 	seq_printf(m, "%3u %6lld %2u %s\n",
50 		   atomic_read(&cell->usage),
51 		   cell->dns_expiry - ktime_get_real_seconds(),
52 		   vllist->nr_servers,
53 		   cell->name);
54 	return 0;
55 }
56 
57 static void *afs_proc_cells_start(struct seq_file *m, loff_t *_pos)
58 	__acquires(rcu)
59 {
60 	rcu_read_lock();
61 	return seq_hlist_start_head_rcu(&afs_seq2net(m)->proc_cells, *_pos);
62 }
63 
64 static void *afs_proc_cells_next(struct seq_file *m, void *v, loff_t *pos)
65 {
66 	return seq_hlist_next_rcu(v, &afs_seq2net(m)->proc_cells, pos);
67 }
68 
69 static void afs_proc_cells_stop(struct seq_file *m, void *v)
70 	__releases(rcu)
71 {
72 	rcu_read_unlock();
73 }
74 
75 static const struct seq_operations afs_proc_cells_ops = {
76 	.start	= afs_proc_cells_start,
77 	.next	= afs_proc_cells_next,
78 	.stop	= afs_proc_cells_stop,
79 	.show	= afs_proc_cells_show,
80 };
81 
82 /*
83  * handle writes to /proc/fs/afs/cells
84  * - to add cells: echo "add <cellname> <IP>[:<IP>][:<IP>]"
85  */
86 static int afs_proc_cells_write(struct file *file, char *buf, size_t size)
87 {
88 	struct seq_file *m = file->private_data;
89 	struct afs_net *net = afs_seq2net(m);
90 	char *name, *args;
91 	int ret;
92 
93 	/* trim to first NL */
94 	name = memchr(buf, '\n', size);
95 	if (name)
96 		*name = 0;
97 
98 	/* split into command, name and argslist */
99 	name = strchr(buf, ' ');
100 	if (!name)
101 		goto inval;
102 	do {
103 		*name++ = 0;
104 	} while(*name == ' ');
105 	if (!*name)
106 		goto inval;
107 
108 	args = strchr(name, ' ');
109 	if (args) {
110 		do {
111 			*args++ = 0;
112 		} while(*args == ' ');
113 		if (!*args)
114 			goto inval;
115 	}
116 
117 	/* determine command to perform */
118 	_debug("cmd=%s name=%s args=%s", buf, name, args);
119 
120 	if (strcmp(buf, "add") == 0) {
121 		struct afs_cell *cell;
122 
123 		cell = afs_lookup_cell(net, name, strlen(name), args, true);
124 		if (IS_ERR(cell)) {
125 			ret = PTR_ERR(cell);
126 			goto done;
127 		}
128 
129 		if (test_and_set_bit(AFS_CELL_FL_NO_GC, &cell->flags))
130 			afs_put_cell(net, cell);
131 	} else {
132 		goto inval;
133 	}
134 
135 	ret = 0;
136 
137 done:
138 	_leave(" = %d", ret);
139 	return ret;
140 
141 inval:
142 	ret = -EINVAL;
143 	printk("kAFS: Invalid Command on /proc/fs/afs/cells file\n");
144 	goto done;
145 }
146 
147 /*
148  * Display the name of the current workstation cell.
149  */
150 static int afs_proc_rootcell_show(struct seq_file *m, void *v)
151 {
152 	struct afs_cell *cell;
153 	struct afs_net *net;
154 
155 	net = afs_seq2net_single(m);
156 	if (rcu_access_pointer(net->ws_cell)) {
157 		rcu_read_lock();
158 		cell = rcu_dereference(net->ws_cell);
159 		if (cell)
160 			seq_printf(m, "%s\n", cell->name);
161 		rcu_read_unlock();
162 	}
163 	return 0;
164 }
165 
166 /*
167  * Set the current workstation cell and optionally supply its list of volume
168  * location servers.
169  *
170  *	echo "cell.name:192.168.231.14" >/proc/fs/afs/rootcell
171  */
172 static int afs_proc_rootcell_write(struct file *file, char *buf, size_t size)
173 {
174 	struct seq_file *m = file->private_data;
175 	struct afs_net *net = afs_seq2net_single(m);
176 	char *s;
177 	int ret;
178 
179 	ret = -EINVAL;
180 	if (buf[0] == '.')
181 		goto out;
182 	if (memchr(buf, '/', size))
183 		goto out;
184 
185 	/* trim to first NL */
186 	s = memchr(buf, '\n', size);
187 	if (s)
188 		*s = 0;
189 
190 	/* determine command to perform */
191 	_debug("rootcell=%s", buf);
192 
193 	ret = afs_cell_init(net, buf);
194 
195 out:
196 	_leave(" = %d", ret);
197 	return ret;
198 }
199 
200 static const char afs_vol_types[3][3] = {
201 	[AFSVL_RWVOL]	= "RW",
202 	[AFSVL_ROVOL]	= "RO",
203 	[AFSVL_BACKVOL]	= "BK",
204 };
205 
206 /*
207  * Display the list of volumes known to a cell.
208  */
209 static int afs_proc_cell_volumes_show(struct seq_file *m, void *v)
210 {
211 	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
212 	struct afs_volume *vol = list_entry(v, struct afs_volume, proc_link);
213 
214 	/* Display header on line 1 */
215 	if (v == &cell->proc_volumes) {
216 		seq_puts(m, "USE VID      TY NAME\n");
217 		return 0;
218 	}
219 
220 	seq_printf(m, "%3d %08llx %s %s\n",
221 		   atomic_read(&vol->usage), vol->vid,
222 		   afs_vol_types[vol->type],
223 		   vol->name);
224 
225 	return 0;
226 }
227 
228 static void *afs_proc_cell_volumes_start(struct seq_file *m, loff_t *_pos)
229 	__acquires(cell->proc_lock)
230 {
231 	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
232 
233 	read_lock(&cell->proc_lock);
234 	return seq_list_start_head(&cell->proc_volumes, *_pos);
235 }
236 
237 static void *afs_proc_cell_volumes_next(struct seq_file *m, void *v,
238 					loff_t *_pos)
239 {
240 	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
241 
242 	return seq_list_next(v, &cell->proc_volumes, _pos);
243 }
244 
245 static void afs_proc_cell_volumes_stop(struct seq_file *m, void *v)
246 	__releases(cell->proc_lock)
247 {
248 	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
249 
250 	read_unlock(&cell->proc_lock);
251 }
252 
253 static const struct seq_operations afs_proc_cell_volumes_ops = {
254 	.start	= afs_proc_cell_volumes_start,
255 	.next	= afs_proc_cell_volumes_next,
256 	.stop	= afs_proc_cell_volumes_stop,
257 	.show	= afs_proc_cell_volumes_show,
258 };
259 
260 static const char *const dns_record_sources[NR__dns_record_source + 1] = {
261 	[DNS_RECORD_UNAVAILABLE]	= "unav",
262 	[DNS_RECORD_FROM_CONFIG]	= "cfg",
263 	[DNS_RECORD_FROM_DNS_A]		= "A",
264 	[DNS_RECORD_FROM_DNS_AFSDB]	= "AFSDB",
265 	[DNS_RECORD_FROM_DNS_SRV]	= "SRV",
266 	[DNS_RECORD_FROM_NSS]		= "nss",
267 	[NR__dns_record_source]		= "[weird]"
268 };
269 
270 static const char *const dns_lookup_statuses[NR__dns_lookup_status + 1] = {
271 	[DNS_LOOKUP_NOT_DONE]		= "no-lookup",
272 	[DNS_LOOKUP_GOOD]		= "good",
273 	[DNS_LOOKUP_GOOD_WITH_BAD]	= "good/bad",
274 	[DNS_LOOKUP_BAD]		= "bad",
275 	[DNS_LOOKUP_GOT_NOT_FOUND]	= "not-found",
276 	[DNS_LOOKUP_GOT_LOCAL_FAILURE]	= "local-failure",
277 	[DNS_LOOKUP_GOT_TEMP_FAILURE]	= "temp-failure",
278 	[DNS_LOOKUP_GOT_NS_FAILURE]	= "ns-failure",
279 	[NR__dns_lookup_status]		= "[weird]"
280 };
281 
282 /*
283  * Display the list of Volume Location servers we're using for a cell.
284  */
285 static int afs_proc_cell_vlservers_show(struct seq_file *m, void *v)
286 {
287 	const struct afs_vl_seq_net_private *priv = m->private;
288 	const struct afs_vlserver_list *vllist = priv->vllist;
289 	const struct afs_vlserver_entry *entry;
290 	const struct afs_vlserver *vlserver;
291 	const struct afs_addr_list *alist;
292 	int i;
293 
294 	if (v == SEQ_START_TOKEN) {
295 		seq_printf(m, "# source %s, status %s\n",
296 			   dns_record_sources[vllist ? vllist->source : 0],
297 			   dns_lookup_statuses[vllist ? vllist->status : 0]);
298 		return 0;
299 	}
300 
301 	entry = v;
302 	vlserver = entry->server;
303 	alist = rcu_dereference(vlserver->addresses);
304 
305 	seq_printf(m, "%s [p=%hu w=%hu s=%s,%s]:\n",
306 		   vlserver->name, entry->priority, entry->weight,
307 		   dns_record_sources[alist ? alist->source : entry->source],
308 		   dns_lookup_statuses[alist ? alist->status : entry->status]);
309 	if (alist) {
310 		for (i = 0; i < alist->nr_addrs; i++)
311 			seq_printf(m, " %c %pISpc\n",
312 				   alist->preferred == i ? '>' : '-',
313 				   &alist->addrs[i].transport);
314 	}
315 	return 0;
316 }
317 
318 static void *afs_proc_cell_vlservers_start(struct seq_file *m, loff_t *_pos)
319 	__acquires(rcu)
320 {
321 	struct afs_vl_seq_net_private *priv = m->private;
322 	struct afs_vlserver_list *vllist;
323 	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
324 	loff_t pos = *_pos;
325 
326 	rcu_read_lock();
327 
328 	vllist = rcu_dereference(cell->vl_servers);
329 	priv->vllist = vllist;
330 
331 	if (pos < 0)
332 		*_pos = pos = 0;
333 	if (pos == 0)
334 		return SEQ_START_TOKEN;
335 
336 	if (pos - 1 >= vllist->nr_servers)
337 		return NULL;
338 
339 	return &vllist->servers[pos - 1];
340 }
341 
342 static void *afs_proc_cell_vlservers_next(struct seq_file *m, void *v,
343 					  loff_t *_pos)
344 {
345 	struct afs_vl_seq_net_private *priv = m->private;
346 	struct afs_vlserver_list *vllist = priv->vllist;
347 	loff_t pos;
348 
349 	pos = *_pos;
350 	pos++;
351 	*_pos = pos;
352 	if (!vllist || pos - 1 >= vllist->nr_servers)
353 		return NULL;
354 
355 	return &vllist->servers[pos - 1];
356 }
357 
358 static void afs_proc_cell_vlservers_stop(struct seq_file *m, void *v)
359 	__releases(rcu)
360 {
361 	rcu_read_unlock();
362 }
363 
364 static const struct seq_operations afs_proc_cell_vlservers_ops = {
365 	.start	= afs_proc_cell_vlservers_start,
366 	.next	= afs_proc_cell_vlservers_next,
367 	.stop	= afs_proc_cell_vlservers_stop,
368 	.show	= afs_proc_cell_vlservers_show,
369 };
370 
371 /*
372  * Display the list of fileservers we're using within a namespace.
373  */
374 static int afs_proc_servers_show(struct seq_file *m, void *v)
375 {
376 	struct afs_server *server;
377 	struct afs_addr_list *alist;
378 	int i;
379 
380 	if (v == SEQ_START_TOKEN) {
381 		seq_puts(m, "UUID                                 USE ADDR\n");
382 		return 0;
383 	}
384 
385 	server = list_entry(v, struct afs_server, proc_link);
386 	alist = rcu_dereference(server->addresses);
387 	seq_printf(m, "%pU %3d %pISpc%s\n",
388 		   &server->uuid,
389 		   atomic_read(&server->usage),
390 		   &alist->addrs[0].transport,
391 		   alist->preferred == 0 ? "*" : "");
392 	for (i = 1; i < alist->nr_addrs; i++)
393 		seq_printf(m, "                                         %pISpc%s\n",
394 			   &alist->addrs[i].transport,
395 			   alist->preferred == i ? "*" : "");
396 	return 0;
397 }
398 
399 static void *afs_proc_servers_start(struct seq_file *m, loff_t *_pos)
400 	__acquires(rcu)
401 {
402 	rcu_read_lock();
403 	return seq_hlist_start_head_rcu(&afs_seq2net(m)->fs_proc, *_pos);
404 }
405 
406 static void *afs_proc_servers_next(struct seq_file *m, void *v, loff_t *_pos)
407 {
408 	return seq_hlist_next_rcu(v, &afs_seq2net(m)->fs_proc, _pos);
409 }
410 
411 static void afs_proc_servers_stop(struct seq_file *m, void *v)
412 	__releases(rcu)
413 {
414 	rcu_read_unlock();
415 }
416 
417 static const struct seq_operations afs_proc_servers_ops = {
418 	.start	= afs_proc_servers_start,
419 	.next	= afs_proc_servers_next,
420 	.stop	= afs_proc_servers_stop,
421 	.show	= afs_proc_servers_show,
422 };
423 
424 /*
425  * Display the list of strings that may be substituted for the @sys pathname
426  * macro.
427  */
428 static int afs_proc_sysname_show(struct seq_file *m, void *v)
429 {
430 	struct afs_net *net = afs_seq2net(m);
431 	struct afs_sysnames *sysnames = net->sysnames;
432 	unsigned int i = (unsigned long)v - 1;
433 
434 	if (i < sysnames->nr)
435 		seq_printf(m, "%s\n", sysnames->subs[i]);
436 	return 0;
437 }
438 
439 static void *afs_proc_sysname_start(struct seq_file *m, loff_t *pos)
440 	__acquires(&net->sysnames_lock)
441 {
442 	struct afs_net *net = afs_seq2net(m);
443 	struct afs_sysnames *names;
444 
445 	read_lock(&net->sysnames_lock);
446 
447 	names = net->sysnames;
448 	if (*pos >= names->nr)
449 		return NULL;
450 	return (void *)(unsigned long)(*pos + 1);
451 }
452 
453 static void *afs_proc_sysname_next(struct seq_file *m, void *v, loff_t *pos)
454 {
455 	struct afs_net *net = afs_seq2net(m);
456 	struct afs_sysnames *names = net->sysnames;
457 
458 	*pos += 1;
459 	if (*pos >= names->nr)
460 		return NULL;
461 	return (void *)(unsigned long)(*pos + 1);
462 }
463 
464 static void afs_proc_sysname_stop(struct seq_file *m, void *v)
465 	__releases(&net->sysnames_lock)
466 {
467 	struct afs_net *net = afs_seq2net(m);
468 
469 	read_unlock(&net->sysnames_lock);
470 }
471 
472 static const struct seq_operations afs_proc_sysname_ops = {
473 	.start	= afs_proc_sysname_start,
474 	.next	= afs_proc_sysname_next,
475 	.stop	= afs_proc_sysname_stop,
476 	.show	= afs_proc_sysname_show,
477 };
478 
479 /*
480  * Allow the @sys substitution to be configured.
481  */
482 static int afs_proc_sysname_write(struct file *file, char *buf, size_t size)
483 {
484 	struct afs_sysnames *sysnames, *kill;
485 	struct seq_file *m = file->private_data;
486 	struct afs_net *net = afs_seq2net(m);
487 	char *s, *p, *sub;
488 	int ret, len;
489 
490 	sysnames = kzalloc(sizeof(*sysnames), GFP_KERNEL);
491 	if (!sysnames)
492 		return -ENOMEM;
493 	refcount_set(&sysnames->usage, 1);
494 	kill = sysnames;
495 
496 	p = buf;
497 	while ((s = strsep(&p, " \t\n"))) {
498 		len = strlen(s);
499 		if (len == 0)
500 			continue;
501 		ret = -ENAMETOOLONG;
502 		if (len >= AFSNAMEMAX)
503 			goto error;
504 
505 		if (len >= 4 &&
506 		    s[len - 4] == '@' &&
507 		    s[len - 3] == 's' &&
508 		    s[len - 2] == 'y' &&
509 		    s[len - 1] == 's')
510 			/* Protect against recursion */
511 			goto invalid;
512 
513 		if (s[0] == '.' &&
514 		    (len < 2 || (len == 2 && s[1] == '.')))
515 			goto invalid;
516 
517 		if (memchr(s, '/', len))
518 			goto invalid;
519 
520 		ret = -EFBIG;
521 		if (sysnames->nr >= AFS_NR_SYSNAME)
522 			goto out;
523 
524 		if (strcmp(s, afs_init_sysname) == 0) {
525 			sub = (char *)afs_init_sysname;
526 		} else {
527 			ret = -ENOMEM;
528 			sub = kmemdup(s, len + 1, GFP_KERNEL);
529 			if (!sub)
530 				goto out;
531 		}
532 
533 		sysnames->subs[sysnames->nr] = sub;
534 		sysnames->nr++;
535 	}
536 
537 	if (sysnames->nr == 0) {
538 		sysnames->subs[0] = sysnames->blank;
539 		sysnames->nr++;
540 	}
541 
542 	write_lock(&net->sysnames_lock);
543 	kill = net->sysnames;
544 	net->sysnames = sysnames;
545 	write_unlock(&net->sysnames_lock);
546 	ret = 0;
547 out:
548 	afs_put_sysnames(kill);
549 	return ret;
550 
551 invalid:
552 	ret = -EINVAL;
553 error:
554 	goto out;
555 }
556 
557 void afs_put_sysnames(struct afs_sysnames *sysnames)
558 {
559 	int i;
560 
561 	if (sysnames && refcount_dec_and_test(&sysnames->usage)) {
562 		for (i = 0; i < sysnames->nr; i++)
563 			if (sysnames->subs[i] != afs_init_sysname &&
564 			    sysnames->subs[i] != sysnames->blank)
565 				kfree(sysnames->subs[i]);
566 	}
567 }
568 
569 /*
570  * Display general per-net namespace statistics
571  */
572 static int afs_proc_stats_show(struct seq_file *m, void *v)
573 {
574 	struct afs_net *net = afs_seq2net_single(m);
575 
576 	seq_puts(m, "kAFS statistics\n");
577 
578 	seq_printf(m, "dir-mgmt: look=%u reval=%u inval=%u relpg=%u\n",
579 		   atomic_read(&net->n_lookup),
580 		   atomic_read(&net->n_reval),
581 		   atomic_read(&net->n_inval),
582 		   atomic_read(&net->n_relpg));
583 
584 	seq_printf(m, "dir-data: rdpg=%u\n",
585 		   atomic_read(&net->n_read_dir));
586 
587 	seq_printf(m, "dir-edit: cr=%u rm=%u\n",
588 		   atomic_read(&net->n_dir_cr),
589 		   atomic_read(&net->n_dir_rm));
590 
591 	seq_printf(m, "file-rd : n=%u nb=%lu\n",
592 		   atomic_read(&net->n_fetches),
593 		   atomic_long_read(&net->n_fetch_bytes));
594 	seq_printf(m, "file-wr : n=%u nb=%lu\n",
595 		   atomic_read(&net->n_stores),
596 		   atomic_long_read(&net->n_store_bytes));
597 	return 0;
598 }
599 
600 /*
601  * initialise /proc/fs/afs/<cell>/
602  */
603 int afs_proc_cell_setup(struct afs_cell *cell)
604 {
605 	struct proc_dir_entry *dir;
606 	struct afs_net *net = cell->net;
607 
608 	_enter("%p{%s},%p", cell, cell->name, net->proc_afs);
609 
610 	dir = proc_net_mkdir(net->net, cell->name, net->proc_afs);
611 	if (!dir)
612 		goto error_dir;
613 
614 	if (!proc_create_net_data("vlservers", 0444, dir,
615 				  &afs_proc_cell_vlservers_ops,
616 				  sizeof(struct afs_vl_seq_net_private),
617 				  cell) ||
618 	    !proc_create_net_data("volumes", 0444, dir,
619 				  &afs_proc_cell_volumes_ops,
620 				  sizeof(struct seq_net_private),
621 				  cell))
622 		goto error_tree;
623 
624 	_leave(" = 0");
625 	return 0;
626 
627 error_tree:
628 	remove_proc_subtree(cell->name, net->proc_afs);
629 error_dir:
630 	_leave(" = -ENOMEM");
631 	return -ENOMEM;
632 }
633 
634 /*
635  * remove /proc/fs/afs/<cell>/
636  */
637 void afs_proc_cell_remove(struct afs_cell *cell)
638 {
639 	struct afs_net *net = cell->net;
640 
641 	_enter("");
642 	remove_proc_subtree(cell->name, net->proc_afs);
643 	_leave("");
644 }
645 
646 /*
647  * initialise the /proc/fs/afs/ directory
648  */
649 int afs_proc_init(struct afs_net *net)
650 {
651 	struct proc_dir_entry *p;
652 
653 	_enter("");
654 
655 	p = proc_net_mkdir(net->net, "afs", net->net->proc_net);
656 	if (!p)
657 		goto error_dir;
658 
659 	if (!proc_create_net_data_write("cells", 0644, p,
660 					&afs_proc_cells_ops,
661 					afs_proc_cells_write,
662 					sizeof(struct seq_net_private),
663 					NULL) ||
664 	    !proc_create_net_single_write("rootcell", 0644, p,
665 					  afs_proc_rootcell_show,
666 					  afs_proc_rootcell_write,
667 					  NULL) ||
668 	    !proc_create_net("servers", 0444, p, &afs_proc_servers_ops,
669 			     sizeof(struct seq_net_private)) ||
670 	    !proc_create_net_single("stats", 0444, p, afs_proc_stats_show, NULL) ||
671 	    !proc_create_net_data_write("sysname", 0644, p,
672 					&afs_proc_sysname_ops,
673 					afs_proc_sysname_write,
674 					sizeof(struct seq_net_private),
675 					NULL))
676 		goto error_tree;
677 
678 	net->proc_afs = p;
679 	_leave(" = 0");
680 	return 0;
681 
682 error_tree:
683 	proc_remove(p);
684 error_dir:
685 	_leave(" = -ENOMEM");
686 	return -ENOMEM;
687 }
688 
689 /*
690  * clean up the /proc/fs/afs/ directory
691  */
692 void afs_proc_cleanup(struct afs_net *net)
693 {
694 	proc_remove(net->proc_afs);
695 	net->proc_afs = NULL;
696 }
697