xref: /openbmc/linux/fs/afs/proc.c (revision f1770e3c)
1 /* /proc interface for AFS
2  *
3  * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 
12 #include <linux/slab.h>
13 #include <linux/module.h>
14 #include <linux/proc_fs.h>
15 #include <linux/seq_file.h>
16 #include <linux/sched.h>
17 #include <linux/uaccess.h>
18 #include "internal.h"
19 
20 struct afs_vl_seq_net_private {
21 	struct seq_net_private		seq;	/* Must be first */
22 	struct afs_vlserver_list	*vllist;
23 };
24 
25 static inline struct afs_net *afs_seq2net(struct seq_file *m)
26 {
27 	return afs_net(seq_file_net(m));
28 }
29 
30 static inline struct afs_net *afs_seq2net_single(struct seq_file *m)
31 {
32 	return afs_net(seq_file_single_net(m));
33 }
34 
35 /*
36  * Display the list of cells known to the namespace.
37  */
38 static int afs_proc_cells_show(struct seq_file *m, void *v)
39 {
40 	struct afs_vlserver_list *vllist;
41 	struct afs_cell *cell;
42 
43 	if (v == SEQ_START_TOKEN) {
44 		/* display header on line 1 */
45 		seq_puts(m, "USE    TTL SV NAME\n");
46 		return 0;
47 	}
48 
49 	cell = list_entry(v, struct afs_cell, proc_link);
50 	vllist = rcu_dereference(cell->vl_servers);
51 
52 	/* display one cell per line on subsequent lines */
53 	seq_printf(m, "%3u %6lld %2u %s\n",
54 		   atomic_read(&cell->usage),
55 		   cell->dns_expiry - ktime_get_real_seconds(),
56 		   vllist ? vllist->nr_servers : 0,
57 		   cell->name);
58 	return 0;
59 }
60 
61 static void *afs_proc_cells_start(struct seq_file *m, loff_t *_pos)
62 	__acquires(rcu)
63 {
64 	rcu_read_lock();
65 	return seq_hlist_start_head_rcu(&afs_seq2net(m)->proc_cells, *_pos);
66 }
67 
68 static void *afs_proc_cells_next(struct seq_file *m, void *v, loff_t *pos)
69 {
70 	return seq_hlist_next_rcu(v, &afs_seq2net(m)->proc_cells, pos);
71 }
72 
73 static void afs_proc_cells_stop(struct seq_file *m, void *v)
74 	__releases(rcu)
75 {
76 	rcu_read_unlock();
77 }
78 
79 static const struct seq_operations afs_proc_cells_ops = {
80 	.start	= afs_proc_cells_start,
81 	.next	= afs_proc_cells_next,
82 	.stop	= afs_proc_cells_stop,
83 	.show	= afs_proc_cells_show,
84 };
85 
86 /*
87  * handle writes to /proc/fs/afs/cells
88  * - to add cells: echo "add <cellname> <IP>[:<IP>][:<IP>]"
89  */
90 static int afs_proc_cells_write(struct file *file, char *buf, size_t size)
91 {
92 	struct seq_file *m = file->private_data;
93 	struct afs_net *net = afs_seq2net(m);
94 	char *name, *args;
95 	int ret;
96 
97 	/* trim to first NL */
98 	name = memchr(buf, '\n', size);
99 	if (name)
100 		*name = 0;
101 
102 	/* split into command, name and argslist */
103 	name = strchr(buf, ' ');
104 	if (!name)
105 		goto inval;
106 	do {
107 		*name++ = 0;
108 	} while(*name == ' ');
109 	if (!*name)
110 		goto inval;
111 
112 	args = strchr(name, ' ');
113 	if (args) {
114 		do {
115 			*args++ = 0;
116 		} while(*args == ' ');
117 		if (!*args)
118 			goto inval;
119 	}
120 
121 	/* determine command to perform */
122 	_debug("cmd=%s name=%s args=%s", buf, name, args);
123 
124 	if (strcmp(buf, "add") == 0) {
125 		struct afs_cell *cell;
126 
127 		cell = afs_lookup_cell(net, name, strlen(name), args, true);
128 		if (IS_ERR(cell)) {
129 			ret = PTR_ERR(cell);
130 			goto done;
131 		}
132 
133 		if (test_and_set_bit(AFS_CELL_FL_NO_GC, &cell->flags))
134 			afs_put_cell(net, cell);
135 	} else {
136 		goto inval;
137 	}
138 
139 	ret = 0;
140 
141 done:
142 	_leave(" = %d", ret);
143 	return ret;
144 
145 inval:
146 	ret = -EINVAL;
147 	printk("kAFS: Invalid Command on /proc/fs/afs/cells file\n");
148 	goto done;
149 }
150 
151 /*
152  * Display the name of the current workstation cell.
153  */
154 static int afs_proc_rootcell_show(struct seq_file *m, void *v)
155 {
156 	struct afs_cell *cell;
157 	struct afs_net *net;
158 
159 	net = afs_seq2net_single(m);
160 	if (rcu_access_pointer(net->ws_cell)) {
161 		rcu_read_lock();
162 		cell = rcu_dereference(net->ws_cell);
163 		if (cell)
164 			seq_printf(m, "%s\n", cell->name);
165 		rcu_read_unlock();
166 	}
167 	return 0;
168 }
169 
170 /*
171  * Set the current workstation cell and optionally supply its list of volume
172  * location servers.
173  *
174  *	echo "cell.name:192.168.231.14" >/proc/fs/afs/rootcell
175  */
176 static int afs_proc_rootcell_write(struct file *file, char *buf, size_t size)
177 {
178 	struct seq_file *m = file->private_data;
179 	struct afs_net *net = afs_seq2net_single(m);
180 	char *s;
181 	int ret;
182 
183 	ret = -EINVAL;
184 	if (buf[0] == '.')
185 		goto out;
186 	if (memchr(buf, '/', size))
187 		goto out;
188 
189 	/* trim to first NL */
190 	s = memchr(buf, '\n', size);
191 	if (s)
192 		*s = 0;
193 
194 	/* determine command to perform */
195 	_debug("rootcell=%s", buf);
196 
197 	ret = afs_cell_init(net, buf);
198 
199 out:
200 	_leave(" = %d", ret);
201 	return ret;
202 }
203 
204 static const char afs_vol_types[3][3] = {
205 	[AFSVL_RWVOL]	= "RW",
206 	[AFSVL_ROVOL]	= "RO",
207 	[AFSVL_BACKVOL]	= "BK",
208 };
209 
210 /*
211  * Display the list of volumes known to a cell.
212  */
213 static int afs_proc_cell_volumes_show(struct seq_file *m, void *v)
214 {
215 	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
216 	struct afs_volume *vol = list_entry(v, struct afs_volume, proc_link);
217 
218 	/* Display header on line 1 */
219 	if (v == &cell->proc_volumes) {
220 		seq_puts(m, "USE VID      TY\n");
221 		return 0;
222 	}
223 
224 	seq_printf(m, "%3d %08llx %s\n",
225 		   atomic_read(&vol->usage), vol->vid,
226 		   afs_vol_types[vol->type]);
227 
228 	return 0;
229 }
230 
231 static void *afs_proc_cell_volumes_start(struct seq_file *m, loff_t *_pos)
232 	__acquires(cell->proc_lock)
233 {
234 	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
235 
236 	read_lock(&cell->proc_lock);
237 	return seq_list_start_head(&cell->proc_volumes, *_pos);
238 }
239 
240 static void *afs_proc_cell_volumes_next(struct seq_file *m, void *v,
241 					loff_t *_pos)
242 {
243 	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
244 
245 	return seq_list_next(v, &cell->proc_volumes, _pos);
246 }
247 
248 static void afs_proc_cell_volumes_stop(struct seq_file *m, void *v)
249 	__releases(cell->proc_lock)
250 {
251 	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
252 
253 	read_unlock(&cell->proc_lock);
254 }
255 
256 static const struct seq_operations afs_proc_cell_volumes_ops = {
257 	.start	= afs_proc_cell_volumes_start,
258 	.next	= afs_proc_cell_volumes_next,
259 	.stop	= afs_proc_cell_volumes_stop,
260 	.show	= afs_proc_cell_volumes_show,
261 };
262 
263 static const char *const dns_record_sources[NR__dns_record_source + 1] = {
264 	[DNS_RECORD_UNAVAILABLE]	= "unav",
265 	[DNS_RECORD_FROM_CONFIG]	= "cfg",
266 	[DNS_RECORD_FROM_DNS_A]		= "A",
267 	[DNS_RECORD_FROM_DNS_AFSDB]	= "AFSDB",
268 	[DNS_RECORD_FROM_DNS_SRV]	= "SRV",
269 	[DNS_RECORD_FROM_NSS]		= "nss",
270 	[NR__dns_record_source]		= "[weird]"
271 };
272 
273 static const char *const dns_lookup_statuses[NR__dns_lookup_status + 1] = {
274 	[DNS_LOOKUP_NOT_DONE]		= "no-lookup",
275 	[DNS_LOOKUP_GOOD]		= "good",
276 	[DNS_LOOKUP_GOOD_WITH_BAD]	= "good/bad",
277 	[DNS_LOOKUP_BAD]		= "bad",
278 	[DNS_LOOKUP_GOT_NOT_FOUND]	= "not-found",
279 	[DNS_LOOKUP_GOT_LOCAL_FAILURE]	= "local-failure",
280 	[DNS_LOOKUP_GOT_TEMP_FAILURE]	= "temp-failure",
281 	[DNS_LOOKUP_GOT_NS_FAILURE]	= "ns-failure",
282 	[NR__dns_lookup_status]		= "[weird]"
283 };
284 
285 /*
286  * Display the list of Volume Location servers we're using for a cell.
287  */
288 static int afs_proc_cell_vlservers_show(struct seq_file *m, void *v)
289 {
290 	const struct afs_vl_seq_net_private *priv = m->private;
291 	const struct afs_vlserver_list *vllist = priv->vllist;
292 	const struct afs_vlserver_entry *entry;
293 	const struct afs_vlserver *vlserver;
294 	const struct afs_addr_list *alist;
295 	int i;
296 
297 	if (v == SEQ_START_TOKEN) {
298 		seq_printf(m, "# source %s, status %s\n",
299 			   dns_record_sources[vllist->source],
300 			   dns_lookup_statuses[vllist->status]);
301 		return 0;
302 	}
303 
304 	entry = v;
305 	vlserver = entry->server;
306 	alist = rcu_dereference(vlserver->addresses);
307 
308 	seq_printf(m, "%s [p=%hu w=%hu s=%s,%s]:\n",
309 		   vlserver->name, entry->priority, entry->weight,
310 		   dns_record_sources[alist ? alist->source : entry->source],
311 		   dns_lookup_statuses[alist ? alist->status : entry->status]);
312 	if (alist) {
313 		for (i = 0; i < alist->nr_addrs; i++)
314 			seq_printf(m, " %c %pISpc\n",
315 				   alist->preferred == i ? '>' : '-',
316 				   &alist->addrs[i].transport);
317 	}
318 	return 0;
319 }
320 
321 static void *afs_proc_cell_vlservers_start(struct seq_file *m, loff_t *_pos)
322 	__acquires(rcu)
323 {
324 	struct afs_vl_seq_net_private *priv = m->private;
325 	struct afs_vlserver_list *vllist;
326 	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
327 	loff_t pos = *_pos;
328 
329 	rcu_read_lock();
330 
331 	vllist = rcu_dereference(cell->vl_servers);
332 	priv->vllist = vllist;
333 
334 	if (pos < 0)
335 		*_pos = pos = 0;
336 	if (pos == 0)
337 		return SEQ_START_TOKEN;
338 
339 	if (!vllist || pos - 1 >= vllist->nr_servers)
340 		return NULL;
341 
342 	return &vllist->servers[pos - 1];
343 }
344 
345 static void *afs_proc_cell_vlservers_next(struct seq_file *m, void *v,
346 					  loff_t *_pos)
347 {
348 	struct afs_vl_seq_net_private *priv = m->private;
349 	struct afs_vlserver_list *vllist = priv->vllist;
350 	loff_t pos;
351 
352 	pos = *_pos;
353 	pos++;
354 	*_pos = pos;
355 	if (!vllist || pos - 1 >= vllist->nr_servers)
356 		return NULL;
357 
358 	return &vllist->servers[pos - 1];
359 }
360 
361 static void afs_proc_cell_vlservers_stop(struct seq_file *m, void *v)
362 	__releases(rcu)
363 {
364 	rcu_read_unlock();
365 }
366 
367 static const struct seq_operations afs_proc_cell_vlservers_ops = {
368 	.start	= afs_proc_cell_vlservers_start,
369 	.next	= afs_proc_cell_vlservers_next,
370 	.stop	= afs_proc_cell_vlservers_stop,
371 	.show	= afs_proc_cell_vlservers_show,
372 };
373 
374 /*
375  * Display the list of fileservers we're using within a namespace.
376  */
377 static int afs_proc_servers_show(struct seq_file *m, void *v)
378 {
379 	struct afs_server *server;
380 	struct afs_addr_list *alist;
381 	int i;
382 
383 	if (v == SEQ_START_TOKEN) {
384 		seq_puts(m, "UUID                                 USE ADDR\n");
385 		return 0;
386 	}
387 
388 	server = list_entry(v, struct afs_server, proc_link);
389 	alist = rcu_dereference(server->addresses);
390 	seq_printf(m, "%pU %3d %pISpc%s\n",
391 		   &server->uuid,
392 		   atomic_read(&server->usage),
393 		   &alist->addrs[0].transport,
394 		   alist->preferred == 0 ? "*" : "");
395 	for (i = 1; i < alist->nr_addrs; i++)
396 		seq_printf(m, "                                         %pISpc%s\n",
397 			   &alist->addrs[i].transport,
398 			   alist->preferred == i ? "*" : "");
399 	return 0;
400 }
401 
402 static void *afs_proc_servers_start(struct seq_file *m, loff_t *_pos)
403 	__acquires(rcu)
404 {
405 	rcu_read_lock();
406 	return seq_hlist_start_head_rcu(&afs_seq2net(m)->fs_proc, *_pos);
407 }
408 
409 static void *afs_proc_servers_next(struct seq_file *m, void *v, loff_t *_pos)
410 {
411 	return seq_hlist_next_rcu(v, &afs_seq2net(m)->fs_proc, _pos);
412 }
413 
414 static void afs_proc_servers_stop(struct seq_file *m, void *v)
415 	__releases(rcu)
416 {
417 	rcu_read_unlock();
418 }
419 
420 static const struct seq_operations afs_proc_servers_ops = {
421 	.start	= afs_proc_servers_start,
422 	.next	= afs_proc_servers_next,
423 	.stop	= afs_proc_servers_stop,
424 	.show	= afs_proc_servers_show,
425 };
426 
427 /*
428  * Display the list of strings that may be substituted for the @sys pathname
429  * macro.
430  */
431 static int afs_proc_sysname_show(struct seq_file *m, void *v)
432 {
433 	struct afs_net *net = afs_seq2net(m);
434 	struct afs_sysnames *sysnames = net->sysnames;
435 	unsigned int i = (unsigned long)v - 1;
436 
437 	if (i < sysnames->nr)
438 		seq_printf(m, "%s\n", sysnames->subs[i]);
439 	return 0;
440 }
441 
442 static void *afs_proc_sysname_start(struct seq_file *m, loff_t *pos)
443 	__acquires(&net->sysnames_lock)
444 {
445 	struct afs_net *net = afs_seq2net(m);
446 	struct afs_sysnames *names;
447 
448 	read_lock(&net->sysnames_lock);
449 
450 	names = net->sysnames;
451 	if (*pos >= names->nr)
452 		return NULL;
453 	return (void *)(unsigned long)(*pos + 1);
454 }
455 
456 static void *afs_proc_sysname_next(struct seq_file *m, void *v, loff_t *pos)
457 {
458 	struct afs_net *net = afs_seq2net(m);
459 	struct afs_sysnames *names = net->sysnames;
460 
461 	*pos += 1;
462 	if (*pos >= names->nr)
463 		return NULL;
464 	return (void *)(unsigned long)(*pos + 1);
465 }
466 
467 static void afs_proc_sysname_stop(struct seq_file *m, void *v)
468 	__releases(&net->sysnames_lock)
469 {
470 	struct afs_net *net = afs_seq2net(m);
471 
472 	read_unlock(&net->sysnames_lock);
473 }
474 
475 static const struct seq_operations afs_proc_sysname_ops = {
476 	.start	= afs_proc_sysname_start,
477 	.next	= afs_proc_sysname_next,
478 	.stop	= afs_proc_sysname_stop,
479 	.show	= afs_proc_sysname_show,
480 };
481 
482 /*
483  * Allow the @sys substitution to be configured.
484  */
485 static int afs_proc_sysname_write(struct file *file, char *buf, size_t size)
486 {
487 	struct afs_sysnames *sysnames, *kill;
488 	struct seq_file *m = file->private_data;
489 	struct afs_net *net = afs_seq2net(m);
490 	char *s, *p, *sub;
491 	int ret, len;
492 
493 	sysnames = kzalloc(sizeof(*sysnames), GFP_KERNEL);
494 	if (!sysnames)
495 		return -ENOMEM;
496 	refcount_set(&sysnames->usage, 1);
497 	kill = sysnames;
498 
499 	p = buf;
500 	while ((s = strsep(&p, " \t\n"))) {
501 		len = strlen(s);
502 		if (len == 0)
503 			continue;
504 		ret = -ENAMETOOLONG;
505 		if (len >= AFSNAMEMAX)
506 			goto error;
507 
508 		if (len >= 4 &&
509 		    s[len - 4] == '@' &&
510 		    s[len - 3] == 's' &&
511 		    s[len - 2] == 'y' &&
512 		    s[len - 1] == 's')
513 			/* Protect against recursion */
514 			goto invalid;
515 
516 		if (s[0] == '.' &&
517 		    (len < 2 || (len == 2 && s[1] == '.')))
518 			goto invalid;
519 
520 		if (memchr(s, '/', len))
521 			goto invalid;
522 
523 		ret = -EFBIG;
524 		if (sysnames->nr >= AFS_NR_SYSNAME)
525 			goto out;
526 
527 		if (strcmp(s, afs_init_sysname) == 0) {
528 			sub = (char *)afs_init_sysname;
529 		} else {
530 			ret = -ENOMEM;
531 			sub = kmemdup(s, len + 1, GFP_KERNEL);
532 			if (!sub)
533 				goto out;
534 		}
535 
536 		sysnames->subs[sysnames->nr] = sub;
537 		sysnames->nr++;
538 	}
539 
540 	if (sysnames->nr == 0) {
541 		sysnames->subs[0] = sysnames->blank;
542 		sysnames->nr++;
543 	}
544 
545 	write_lock(&net->sysnames_lock);
546 	kill = net->sysnames;
547 	net->sysnames = sysnames;
548 	write_unlock(&net->sysnames_lock);
549 	ret = 0;
550 out:
551 	afs_put_sysnames(kill);
552 	return ret;
553 
554 invalid:
555 	ret = -EINVAL;
556 error:
557 	goto out;
558 }
559 
560 void afs_put_sysnames(struct afs_sysnames *sysnames)
561 {
562 	int i;
563 
564 	if (sysnames && refcount_dec_and_test(&sysnames->usage)) {
565 		for (i = 0; i < sysnames->nr; i++)
566 			if (sysnames->subs[i] != afs_init_sysname &&
567 			    sysnames->subs[i] != sysnames->blank)
568 				kfree(sysnames->subs[i]);
569 	}
570 }
571 
572 /*
573  * Display general per-net namespace statistics
574  */
575 static int afs_proc_stats_show(struct seq_file *m, void *v)
576 {
577 	struct afs_net *net = afs_seq2net_single(m);
578 
579 	seq_puts(m, "kAFS statistics\n");
580 
581 	seq_printf(m, "dir-mgmt: look=%u reval=%u inval=%u relpg=%u\n",
582 		   atomic_read(&net->n_lookup),
583 		   atomic_read(&net->n_reval),
584 		   atomic_read(&net->n_inval),
585 		   atomic_read(&net->n_relpg));
586 
587 	seq_printf(m, "dir-data: rdpg=%u\n",
588 		   atomic_read(&net->n_read_dir));
589 
590 	seq_printf(m, "dir-edit: cr=%u rm=%u\n",
591 		   atomic_read(&net->n_dir_cr),
592 		   atomic_read(&net->n_dir_rm));
593 
594 	seq_printf(m, "file-rd : n=%u nb=%lu\n",
595 		   atomic_read(&net->n_fetches),
596 		   atomic_long_read(&net->n_fetch_bytes));
597 	seq_printf(m, "file-wr : n=%u nb=%lu\n",
598 		   atomic_read(&net->n_stores),
599 		   atomic_long_read(&net->n_store_bytes));
600 	return 0;
601 }
602 
603 /*
604  * initialise /proc/fs/afs/<cell>/
605  */
606 int afs_proc_cell_setup(struct afs_cell *cell)
607 {
608 	struct proc_dir_entry *dir;
609 	struct afs_net *net = cell->net;
610 
611 	_enter("%p{%s},%p", cell, cell->name, net->proc_afs);
612 
613 	dir = proc_net_mkdir(net->net, cell->name, net->proc_afs);
614 	if (!dir)
615 		goto error_dir;
616 
617 	if (!proc_create_net_data("vlservers", 0444, dir,
618 				  &afs_proc_cell_vlservers_ops,
619 				  sizeof(struct afs_vl_seq_net_private),
620 				  cell) ||
621 	    !proc_create_net_data("volumes", 0444, dir,
622 				  &afs_proc_cell_volumes_ops,
623 				  sizeof(struct seq_net_private),
624 				  cell))
625 		goto error_tree;
626 
627 	_leave(" = 0");
628 	return 0;
629 
630 error_tree:
631 	remove_proc_subtree(cell->name, net->proc_afs);
632 error_dir:
633 	_leave(" = -ENOMEM");
634 	return -ENOMEM;
635 }
636 
637 /*
638  * remove /proc/fs/afs/<cell>/
639  */
640 void afs_proc_cell_remove(struct afs_cell *cell)
641 {
642 	struct afs_net *net = cell->net;
643 
644 	_enter("");
645 	remove_proc_subtree(cell->name, net->proc_afs);
646 	_leave("");
647 }
648 
649 /*
650  * initialise the /proc/fs/afs/ directory
651  */
652 int afs_proc_init(struct afs_net *net)
653 {
654 	struct proc_dir_entry *p;
655 
656 	_enter("");
657 
658 	p = proc_net_mkdir(net->net, "afs", net->net->proc_net);
659 	if (!p)
660 		goto error_dir;
661 
662 	if (!proc_create_net_data_write("cells", 0644, p,
663 					&afs_proc_cells_ops,
664 					afs_proc_cells_write,
665 					sizeof(struct seq_net_private),
666 					NULL) ||
667 	    !proc_create_net_single_write("rootcell", 0644, p,
668 					  afs_proc_rootcell_show,
669 					  afs_proc_rootcell_write,
670 					  NULL) ||
671 	    !proc_create_net("servers", 0444, p, &afs_proc_servers_ops,
672 			     sizeof(struct seq_net_private)) ||
673 	    !proc_create_net_single("stats", 0444, p, afs_proc_stats_show, NULL) ||
674 	    !proc_create_net_data_write("sysname", 0644, p,
675 					&afs_proc_sysname_ops,
676 					afs_proc_sysname_write,
677 					sizeof(struct seq_net_private),
678 					NULL))
679 		goto error_tree;
680 
681 	net->proc_afs = p;
682 	_leave(" = 0");
683 	return 0;
684 
685 error_tree:
686 	proc_remove(p);
687 error_dir:
688 	_leave(" = -ENOMEM");
689 	return -ENOMEM;
690 }
691 
692 /*
693  * clean up the /proc/fs/afs/ directory
694  */
695 void afs_proc_cleanup(struct afs_net *net)
696 {
697 	proc_remove(net->proc_afs);
698 	net->proc_afs = NULL;
699 }
700