xref: /linux/fs/nfsd/export.c (revision 2c1ed907520c50326b8f604907a8478b27881a2e)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * NFS exporting and validation.
4  *
5  * We maintain a list of clients, each of which has a list of
6  * exports. To export an fs to a given client, you first have
7  * to create the client entry with NFSCTL_ADDCLIENT, which
8  * creates a client control block and adds it to the hash
9  * table. Then, you call NFSCTL_EXPORT for each fs.
10  *
11  *
12  * Copyright (C) 1995, 1996 Olaf Kirch, <okir@monad.swb.de>
13  */
14 
15 #include <linux/slab.h>
16 #include <linux/namei.h>
17 #include <linux/module.h>
18 #include <linux/exportfs.h>
19 #include <linux/sunrpc/svc_xprt.h>
20 
21 #include "nfsd.h"
22 #include "nfsfh.h"
23 #include "netns.h"
24 #include "pnfs.h"
25 #include "filecache.h"
26 #include "trace.h"
27 
28 #define NFSDDBG_FACILITY	NFSDDBG_EXPORT
29 
30 /*
31  * We have two caches.
32  * One maps client+vfsmnt+dentry to export options - the export map
33  * The other maps client+filehandle-fragment to export options. - the expkey map
34  *
35  * The export options are actually stored in the first map, and the
36  * second map contains a reference to the entry in the first map.
37  */
38 
39 #define	EXPKEY_HASHBITS		8
40 #define	EXPKEY_HASHMAX		(1 << EXPKEY_HASHBITS)
41 #define	EXPKEY_HASHMASK		(EXPKEY_HASHMAX -1)
42 
expkey_put(struct kref * ref)43 static void expkey_put(struct kref *ref)
44 {
45 	struct svc_expkey *key = container_of(ref, struct svc_expkey, h.ref);
46 
47 	if (test_bit(CACHE_VALID, &key->h.flags) &&
48 	    !test_bit(CACHE_NEGATIVE, &key->h.flags))
49 		path_put(&key->ek_path);
50 	auth_domain_put(key->ek_client);
51 	kfree_rcu(key, ek_rcu);
52 }
53 
expkey_upcall(struct cache_detail * cd,struct cache_head * h)54 static int expkey_upcall(struct cache_detail *cd, struct cache_head *h)
55 {
56 	return sunrpc_cache_pipe_upcall(cd, h);
57 }
58 
expkey_request(struct cache_detail * cd,struct cache_head * h,char ** bpp,int * blen)59 static void expkey_request(struct cache_detail *cd,
60 			   struct cache_head *h,
61 			   char **bpp, int *blen)
62 {
63 	/* client fsidtype \xfsid */
64 	struct svc_expkey *ek = container_of(h, struct svc_expkey, h);
65 	char type[5];
66 
67 	qword_add(bpp, blen, ek->ek_client->name);
68 	snprintf(type, 5, "%d", ek->ek_fsidtype);
69 	qword_add(bpp, blen, type);
70 	qword_addhex(bpp, blen, (char*)ek->ek_fsid, key_len(ek->ek_fsidtype));
71 	(*bpp)[-1] = '\n';
72 }
73 
74 static struct svc_expkey *svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
75 					    struct svc_expkey *old);
76 static struct svc_expkey *svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *);
77 
expkey_parse(struct cache_detail * cd,char * mesg,int mlen)78 static int expkey_parse(struct cache_detail *cd, char *mesg, int mlen)
79 {
80 	/* client fsidtype fsid expiry [path] */
81 	char *buf;
82 	int len;
83 	struct auth_domain *dom = NULL;
84 	int err;
85 	int fsidtype;
86 	char *ep;
87 	struct svc_expkey key;
88 	struct svc_expkey *ek = NULL;
89 
90 	if (mesg[mlen - 1] != '\n')
91 		return -EINVAL;
92 	mesg[mlen-1] = 0;
93 
94 	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
95 	err = -ENOMEM;
96 	if (!buf)
97 		goto out;
98 
99 	err = -EINVAL;
100 	if (qword_get(&mesg, buf, PAGE_SIZE) <= 0)
101 		goto out;
102 
103 	err = -ENOENT;
104 	dom = auth_domain_find(buf);
105 	if (!dom)
106 		goto out;
107 	dprintk("found domain %s\n", buf);
108 
109 	err = -EINVAL;
110 	if (qword_get(&mesg, buf, PAGE_SIZE) <= 0)
111 		goto out;
112 	fsidtype = simple_strtoul(buf, &ep, 10);
113 	if (*ep)
114 		goto out;
115 	dprintk("found fsidtype %d\n", fsidtype);
116 	if (key_len(fsidtype)==0) /* invalid type */
117 		goto out;
118 	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
119 		goto out;
120 	dprintk("found fsid length %d\n", len);
121 	if (len != key_len(fsidtype))
122 		goto out;
123 
124 	/* OK, we seem to have a valid key */
125 	key.h.flags = 0;
126 	err = get_expiry(&mesg, &key.h.expiry_time);
127 	if (err)
128 		goto out;
129 
130 	key.ek_client = dom;
131 	key.ek_fsidtype = fsidtype;
132 	memcpy(key.ek_fsid, buf, len);
133 
134 	ek = svc_expkey_lookup(cd, &key);
135 	err = -ENOMEM;
136 	if (!ek)
137 		goto out;
138 
139 	/* now we want a pathname, or empty meaning NEGATIVE  */
140 	err = -EINVAL;
141 	len = qword_get(&mesg, buf, PAGE_SIZE);
142 	if (len < 0)
143 		goto out;
144 	dprintk("Path seems to be <%s>\n", buf);
145 	err = 0;
146 	if (len == 0) {
147 		set_bit(CACHE_NEGATIVE, &key.h.flags);
148 		ek = svc_expkey_update(cd, &key, ek);
149 		if (ek)
150 			trace_nfsd_expkey_update(ek, NULL);
151 		else
152 			err = -ENOMEM;
153 	} else {
154 		err = kern_path(buf, 0, &key.ek_path);
155 		if (err)
156 			goto out;
157 
158 		dprintk("Found the path %s\n", buf);
159 
160 		ek = svc_expkey_update(cd, &key, ek);
161 		if (ek)
162 			trace_nfsd_expkey_update(ek, buf);
163 		else
164 			err = -ENOMEM;
165 		path_put(&key.ek_path);
166 	}
167 	cache_flush();
168  out:
169 	if (ek)
170 		cache_put(&ek->h, cd);
171 	if (dom)
172 		auth_domain_put(dom);
173 	kfree(buf);
174 	return err;
175 }
176 
expkey_show(struct seq_file * m,struct cache_detail * cd,struct cache_head * h)177 static int expkey_show(struct seq_file *m,
178 		       struct cache_detail *cd,
179 		       struct cache_head *h)
180 {
181 	struct svc_expkey *ek ;
182 	int i;
183 
184 	if (h ==NULL) {
185 		seq_puts(m, "#domain fsidtype fsid [path]\n");
186 		return 0;
187 	}
188 	ek = container_of(h, struct svc_expkey, h);
189 	seq_printf(m, "%s %d 0x", ek->ek_client->name,
190 		   ek->ek_fsidtype);
191 	for (i=0; i < key_len(ek->ek_fsidtype)/4; i++)
192 		seq_printf(m, "%08x", ek->ek_fsid[i]);
193 	if (test_bit(CACHE_VALID, &h->flags) &&
194 	    !test_bit(CACHE_NEGATIVE, &h->flags)) {
195 		seq_printf(m, " ");
196 		seq_path(m, &ek->ek_path, "\\ \t\n");
197 	}
198 	seq_printf(m, "\n");
199 	return 0;
200 }
201 
expkey_match(struct cache_head * a,struct cache_head * b)202 static inline int expkey_match (struct cache_head *a, struct cache_head *b)
203 {
204 	struct svc_expkey *orig = container_of(a, struct svc_expkey, h);
205 	struct svc_expkey *new = container_of(b, struct svc_expkey, h);
206 
207 	if (orig->ek_fsidtype != new->ek_fsidtype ||
208 	    orig->ek_client != new->ek_client ||
209 	    memcmp(orig->ek_fsid, new->ek_fsid, key_len(orig->ek_fsidtype)) != 0)
210 		return 0;
211 	return 1;
212 }
213 
expkey_init(struct cache_head * cnew,struct cache_head * citem)214 static inline void expkey_init(struct cache_head *cnew,
215 				   struct cache_head *citem)
216 {
217 	struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
218 	struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
219 
220 	kref_get(&item->ek_client->ref);
221 	new->ek_client = item->ek_client;
222 	new->ek_fsidtype = item->ek_fsidtype;
223 
224 	memcpy(new->ek_fsid, item->ek_fsid, sizeof(new->ek_fsid));
225 }
226 
expkey_update(struct cache_head * cnew,struct cache_head * citem)227 static inline void expkey_update(struct cache_head *cnew,
228 				   struct cache_head *citem)
229 {
230 	struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
231 	struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
232 
233 	new->ek_path = item->ek_path;
234 	path_get(&item->ek_path);
235 }
236 
expkey_alloc(void)237 static struct cache_head *expkey_alloc(void)
238 {
239 	struct svc_expkey *i = kmalloc(sizeof(*i), GFP_KERNEL);
240 	if (i)
241 		return &i->h;
242 	else
243 		return NULL;
244 }
245 
expkey_flush(void)246 static void expkey_flush(void)
247 {
248 	/*
249 	 * Take the nfsd_mutex here to ensure that the file cache is not
250 	 * destroyed while we're in the middle of flushing.
251 	 */
252 	mutex_lock(&nfsd_mutex);
253 	nfsd_file_cache_purge(current->nsproxy->net_ns);
254 	mutex_unlock(&nfsd_mutex);
255 }
256 
257 static const struct cache_detail svc_expkey_cache_template = {
258 	.owner		= THIS_MODULE,
259 	.hash_size	= EXPKEY_HASHMAX,
260 	.name		= "nfsd.fh",
261 	.cache_put	= expkey_put,
262 	.cache_upcall	= expkey_upcall,
263 	.cache_request	= expkey_request,
264 	.cache_parse	= expkey_parse,
265 	.cache_show	= expkey_show,
266 	.match		= expkey_match,
267 	.init		= expkey_init,
268 	.update       	= expkey_update,
269 	.alloc		= expkey_alloc,
270 	.flush		= expkey_flush,
271 };
272 
273 static int
svc_expkey_hash(struct svc_expkey * item)274 svc_expkey_hash(struct svc_expkey *item)
275 {
276 	int hash = item->ek_fsidtype;
277 	char * cp = (char*)item->ek_fsid;
278 	int len = key_len(item->ek_fsidtype);
279 
280 	hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
281 	hash ^= hash_ptr(item->ek_client, EXPKEY_HASHBITS);
282 	hash &= EXPKEY_HASHMASK;
283 	return hash;
284 }
285 
286 static struct svc_expkey *
svc_expkey_lookup(struct cache_detail * cd,struct svc_expkey * item)287 svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *item)
288 {
289 	struct cache_head *ch;
290 	int hash = svc_expkey_hash(item);
291 
292 	ch = sunrpc_cache_lookup_rcu(cd, &item->h, hash);
293 	if (ch)
294 		return container_of(ch, struct svc_expkey, h);
295 	else
296 		return NULL;
297 }
298 
299 static struct svc_expkey *
svc_expkey_update(struct cache_detail * cd,struct svc_expkey * new,struct svc_expkey * old)300 svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
301 		  struct svc_expkey *old)
302 {
303 	struct cache_head *ch;
304 	int hash = svc_expkey_hash(new);
305 
306 	ch = sunrpc_cache_update(cd, &new->h, &old->h, hash);
307 	if (ch)
308 		return container_of(ch, struct svc_expkey, h);
309 	else
310 		return NULL;
311 }
312 
313 
314 #define	EXPORT_HASHBITS		8
315 #define	EXPORT_HASHMAX		(1<< EXPORT_HASHBITS)
316 
nfsd4_fslocs_free(struct nfsd4_fs_locations * fsloc)317 static void nfsd4_fslocs_free(struct nfsd4_fs_locations *fsloc)
318 {
319 	struct nfsd4_fs_location *locations = fsloc->locations;
320 	int i;
321 
322 	if (!locations)
323 		return;
324 
325 	for (i = 0; i < fsloc->locations_count; i++) {
326 		kfree(locations[i].path);
327 		kfree(locations[i].hosts);
328 	}
329 
330 	kfree(locations);
331 	fsloc->locations = NULL;
332 }
333 
export_stats_init(struct export_stats * stats)334 static int export_stats_init(struct export_stats *stats)
335 {
336 	stats->start_time = ktime_get_seconds();
337 	return percpu_counter_init_many(stats->counter, 0, GFP_KERNEL,
338 					EXP_STATS_COUNTERS_NUM);
339 }
340 
export_stats_reset(struct export_stats * stats)341 static void export_stats_reset(struct export_stats *stats)
342 {
343 	if (stats) {
344 		int i;
345 
346 		for (i = 0; i < EXP_STATS_COUNTERS_NUM; i++)
347 			percpu_counter_set(&stats->counter[i], 0);
348 	}
349 }
350 
export_stats_destroy(struct export_stats * stats)351 static void export_stats_destroy(struct export_stats *stats)
352 {
353 	if (stats)
354 		percpu_counter_destroy_many(stats->counter,
355 					    EXP_STATS_COUNTERS_NUM);
356 }
357 
svc_export_release(struct rcu_head * rcu_head)358 static void svc_export_release(struct rcu_head *rcu_head)
359 {
360 	struct svc_export *exp = container_of(rcu_head, struct svc_export,
361 			ex_rcu);
362 
363 	nfsd4_fslocs_free(&exp->ex_fslocs);
364 	export_stats_destroy(exp->ex_stats);
365 	kfree(exp->ex_stats);
366 	kfree(exp->ex_uuid);
367 	kfree(exp);
368 }
369 
svc_export_put(struct kref * ref)370 static void svc_export_put(struct kref *ref)
371 {
372 	struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
373 
374 	path_put(&exp->ex_path);
375 	auth_domain_put(exp->ex_client);
376 	call_rcu(&exp->ex_rcu, svc_export_release);
377 }
378 
svc_export_upcall(struct cache_detail * cd,struct cache_head * h)379 static int svc_export_upcall(struct cache_detail *cd, struct cache_head *h)
380 {
381 	return sunrpc_cache_pipe_upcall(cd, h);
382 }
383 
svc_export_request(struct cache_detail * cd,struct cache_head * h,char ** bpp,int * blen)384 static void svc_export_request(struct cache_detail *cd,
385 			       struct cache_head *h,
386 			       char **bpp, int *blen)
387 {
388 	/*  client path */
389 	struct svc_export *exp = container_of(h, struct svc_export, h);
390 	char *pth;
391 
392 	qword_add(bpp, blen, exp->ex_client->name);
393 	pth = d_path(&exp->ex_path, *bpp, *blen);
394 	if (IS_ERR(pth)) {
395 		/* is this correct? */
396 		(*bpp)[0] = '\n';
397 		return;
398 	}
399 	qword_add(bpp, blen, pth);
400 	(*bpp)[-1] = '\n';
401 }
402 
403 static struct svc_export *svc_export_update(struct svc_export *new,
404 					    struct svc_export *old);
405 static struct svc_export *svc_export_lookup(struct svc_export *);
406 
check_export(struct path * path,int * flags,unsigned char * uuid)407 static int check_export(struct path *path, int *flags, unsigned char *uuid)
408 {
409 	struct inode *inode = d_inode(path->dentry);
410 
411 	/*
412 	 * We currently export only dirs, regular files, and (for v4
413 	 * pseudoroot) symlinks.
414 	 */
415 	if (!S_ISDIR(inode->i_mode) &&
416 	    !S_ISLNK(inode->i_mode) &&
417 	    !S_ISREG(inode->i_mode))
418 		return -ENOTDIR;
419 
420 	/*
421 	 * Mountd should never pass down a writeable V4ROOT export, but,
422 	 * just to make sure:
423 	 */
424 	if (*flags & NFSEXP_V4ROOT)
425 		*flags |= NFSEXP_READONLY;
426 
427 	/* There are two requirements on a filesystem to be exportable.
428 	 * 1:  We must be able to identify the filesystem from a number.
429 	 *       either a device number (so FS_REQUIRES_DEV needed)
430 	 *       or an FSID number (so NFSEXP_FSID or ->uuid is needed).
431 	 * 2:  We must be able to find an inode from a filehandle.
432 	 *       This means that s_export_op must be set.
433 	 * 3: We must not currently be on an idmapped mount.
434 	 */
435 	if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) &&
436 	    !(*flags & NFSEXP_FSID) &&
437 	    uuid == NULL) {
438 		dprintk("exp_export: export of non-dev fs without fsid\n");
439 		return -EINVAL;
440 	}
441 
442 	if (!exportfs_can_decode_fh(inode->i_sb->s_export_op)) {
443 		dprintk("exp_export: export of invalid fs type.\n");
444 		return -EINVAL;
445 	}
446 
447 	if (is_idmapped_mnt(path->mnt)) {
448 		dprintk("exp_export: export of idmapped mounts not yet supported.\n");
449 		return -EINVAL;
450 	}
451 
452 	if (inode->i_sb->s_export_op->flags & EXPORT_OP_NOSUBTREECHK &&
453 	    !(*flags & NFSEXP_NOSUBTREECHECK)) {
454 		dprintk("%s: %s does not support subtree checking!\n",
455 			__func__, inode->i_sb->s_type->name);
456 		return -EINVAL;
457 	}
458 	return 0;
459 }
460 
461 #ifdef CONFIG_NFSD_V4
462 
463 static int
fsloc_parse(char ** mesg,char * buf,struct nfsd4_fs_locations * fsloc)464 fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc)
465 {
466 	int len;
467 	int migrated, i, err;
468 
469 	/* more than one fsloc */
470 	if (fsloc->locations)
471 		return -EINVAL;
472 
473 	/* listsize */
474 	err = get_uint(mesg, &fsloc->locations_count);
475 	if (err)
476 		return err;
477 	if (fsloc->locations_count > MAX_FS_LOCATIONS)
478 		return -EINVAL;
479 	if (fsloc->locations_count == 0)
480 		return 0;
481 
482 	fsloc->locations = kcalloc(fsloc->locations_count,
483 				   sizeof(struct nfsd4_fs_location),
484 				   GFP_KERNEL);
485 	if (!fsloc->locations)
486 		return -ENOMEM;
487 	for (i=0; i < fsloc->locations_count; i++) {
488 		/* colon separated host list */
489 		err = -EINVAL;
490 		len = qword_get(mesg, buf, PAGE_SIZE);
491 		if (len <= 0)
492 			goto out_free_all;
493 		err = -ENOMEM;
494 		fsloc->locations[i].hosts = kstrdup(buf, GFP_KERNEL);
495 		if (!fsloc->locations[i].hosts)
496 			goto out_free_all;
497 		err = -EINVAL;
498 		/* slash separated path component list */
499 		len = qword_get(mesg, buf, PAGE_SIZE);
500 		if (len <= 0)
501 			goto out_free_all;
502 		err = -ENOMEM;
503 		fsloc->locations[i].path = kstrdup(buf, GFP_KERNEL);
504 		if (!fsloc->locations[i].path)
505 			goto out_free_all;
506 	}
507 	/* migrated */
508 	err = get_int(mesg, &migrated);
509 	if (err)
510 		goto out_free_all;
511 	err = -EINVAL;
512 	if (migrated < 0 || migrated > 1)
513 		goto out_free_all;
514 	fsloc->migrated = migrated;
515 	return 0;
516 out_free_all:
517 	nfsd4_fslocs_free(fsloc);
518 	return err;
519 }
520 
secinfo_parse(char ** mesg,char * buf,struct svc_export * exp)521 static int secinfo_parse(char **mesg, char *buf, struct svc_export *exp)
522 {
523 	struct exp_flavor_info *f;
524 	u32 listsize;
525 	int err;
526 
527 	/* more than one secinfo */
528 	if (exp->ex_nflavors)
529 		return -EINVAL;
530 
531 	err = get_uint(mesg, &listsize);
532 	if (err)
533 		return err;
534 	if (listsize > MAX_SECINFO_LIST)
535 		return -EINVAL;
536 
537 	for (f = exp->ex_flavors; f < exp->ex_flavors + listsize; f++) {
538 		err = get_uint(mesg, &f->pseudoflavor);
539 		if (err)
540 			return err;
541 		/*
542 		 * XXX: It would be nice to also check whether this
543 		 * pseudoflavor is supported, so we can discover the
544 		 * problem at export time instead of when a client fails
545 		 * to authenticate.
546 		 */
547 		err = get_uint(mesg, &f->flags);
548 		if (err)
549 			return err;
550 		/* Only some flags are allowed to differ between flavors: */
551 		if (~NFSEXP_SECINFO_FLAGS & (f->flags ^ exp->ex_flags))
552 			return -EINVAL;
553 	}
554 	exp->ex_nflavors = listsize;
555 	return 0;
556 }
557 
558 #else /* CONFIG_NFSD_V4 */
559 static inline int
fsloc_parse(char ** mesg,char * buf,struct nfsd4_fs_locations * fsloc)560 fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc){return 0;}
561 static inline int
secinfo_parse(char ** mesg,char * buf,struct svc_export * exp)562 secinfo_parse(char **mesg, char *buf, struct svc_export *exp) { return 0; }
563 #endif
564 
xprtsec_parse(char ** mesg,char * buf,struct svc_export * exp)565 static int xprtsec_parse(char **mesg, char *buf, struct svc_export *exp)
566 {
567 	unsigned int i, mode, listsize;
568 	int err;
569 
570 	err = get_uint(mesg, &listsize);
571 	if (err)
572 		return err;
573 	if (listsize > NFSEXP_XPRTSEC_NUM)
574 		return -EINVAL;
575 
576 	exp->ex_xprtsec_modes = 0;
577 	for (i = 0; i < listsize; i++) {
578 		err = get_uint(mesg, &mode);
579 		if (err)
580 			return err;
581 		if (mode > NFSEXP_XPRTSEC_MTLS)
582 			return -EINVAL;
583 		exp->ex_xprtsec_modes |= mode;
584 	}
585 	return 0;
586 }
587 
588 static inline int
nfsd_uuid_parse(char ** mesg,char * buf,unsigned char ** puuid)589 nfsd_uuid_parse(char **mesg, char *buf, unsigned char **puuid)
590 {
591 	int len;
592 
593 	/* more than one uuid */
594 	if (*puuid)
595 		return -EINVAL;
596 
597 	/* expect a 16 byte uuid encoded as \xXXXX... */
598 	len = qword_get(mesg, buf, PAGE_SIZE);
599 	if (len != EX_UUID_LEN)
600 		return -EINVAL;
601 
602 	*puuid = kmemdup(buf, EX_UUID_LEN, GFP_KERNEL);
603 	if (*puuid == NULL)
604 		return -ENOMEM;
605 
606 	return 0;
607 }
608 
svc_export_parse(struct cache_detail * cd,char * mesg,int mlen)609 static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
610 {
611 	/* client path expiry [flags anonuid anongid fsid] */
612 	char *buf;
613 	int err;
614 	struct auth_domain *dom = NULL;
615 	struct svc_export exp = {}, *expp;
616 	int an_int;
617 
618 	if (mesg[mlen-1] != '\n')
619 		return -EINVAL;
620 	mesg[mlen-1] = 0;
621 
622 	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
623 	if (!buf)
624 		return -ENOMEM;
625 
626 	/* client */
627 	err = -EINVAL;
628 	if (qword_get(&mesg, buf, PAGE_SIZE) <= 0)
629 		goto out;
630 
631 	err = -ENOENT;
632 	dom = auth_domain_find(buf);
633 	if (!dom)
634 		goto out;
635 
636 	/* path */
637 	err = -EINVAL;
638 	if (qword_get(&mesg, buf, PAGE_SIZE) <= 0)
639 		goto out1;
640 
641 	err = kern_path(buf, 0, &exp.ex_path);
642 	if (err)
643 		goto out1;
644 
645 	exp.ex_client = dom;
646 	exp.cd = cd;
647 	exp.ex_devid_map = NULL;
648 	exp.ex_xprtsec_modes = NFSEXP_XPRTSEC_ALL;
649 
650 	/* expiry */
651 	err = get_expiry(&mesg, &exp.h.expiry_time);
652 	if (err)
653 		goto out3;
654 
655 	/* flags */
656 	err = get_int(&mesg, &an_int);
657 	if (err == -ENOENT) {
658 		err = 0;
659 		set_bit(CACHE_NEGATIVE, &exp.h.flags);
660 	} else {
661 		if (err || an_int < 0)
662 			goto out3;
663 		exp.ex_flags= an_int;
664 
665 		/* anon uid */
666 		err = get_int(&mesg, &an_int);
667 		if (err)
668 			goto out3;
669 		exp.ex_anon_uid= make_kuid(current_user_ns(), an_int);
670 
671 		/* anon gid */
672 		err = get_int(&mesg, &an_int);
673 		if (err)
674 			goto out3;
675 		exp.ex_anon_gid= make_kgid(current_user_ns(), an_int);
676 
677 		/* fsid */
678 		err = get_int(&mesg, &an_int);
679 		if (err)
680 			goto out3;
681 		exp.ex_fsid = an_int;
682 
683 		while (qword_get(&mesg, buf, PAGE_SIZE) > 0) {
684 			if (strcmp(buf, "fsloc") == 0)
685 				err = fsloc_parse(&mesg, buf, &exp.ex_fslocs);
686 			else if (strcmp(buf, "uuid") == 0)
687 				err = nfsd_uuid_parse(&mesg, buf, &exp.ex_uuid);
688 			else if (strcmp(buf, "secinfo") == 0)
689 				err = secinfo_parse(&mesg, buf, &exp);
690 			else if (strcmp(buf, "xprtsec") == 0)
691 				err = xprtsec_parse(&mesg, buf, &exp);
692 			else
693 				/* quietly ignore unknown words and anything
694 				 * following. Newer user-space can try to set
695 				 * new values, then see what the result was.
696 				 */
697 				break;
698 			if (err)
699 				goto out4;
700 		}
701 
702 		err = check_export(&exp.ex_path, &exp.ex_flags, exp.ex_uuid);
703 		if (err)
704 			goto out4;
705 
706 		/*
707 		 * No point caching this if it would immediately expire.
708 		 * Also, this protects exportfs's dummy export from the
709 		 * anon_uid/anon_gid checks:
710 		 */
711 		if (exp.h.expiry_time < seconds_since_boot())
712 			goto out4;
713 		/*
714 		 * For some reason exportfs has been passing down an
715 		 * invalid (-1) uid & gid on the "dummy" export which it
716 		 * uses to test export support.  To make sure exportfs
717 		 * sees errors from check_export we therefore need to
718 		 * delay these checks till after check_export:
719 		 */
720 		err = -EINVAL;
721 		if (!uid_valid(exp.ex_anon_uid))
722 			goto out4;
723 		if (!gid_valid(exp.ex_anon_gid))
724 			goto out4;
725 		err = 0;
726 
727 		nfsd4_setup_layout_type(&exp);
728 	}
729 
730 	expp = svc_export_lookup(&exp);
731 	if (!expp) {
732 		err = -ENOMEM;
733 		goto out4;
734 	}
735 	expp = svc_export_update(&exp, expp);
736 	if (expp) {
737 		trace_nfsd_export_update(expp);
738 		cache_flush();
739 		exp_put(expp);
740 	} else
741 		err = -ENOMEM;
742 out4:
743 	nfsd4_fslocs_free(&exp.ex_fslocs);
744 	kfree(exp.ex_uuid);
745 out3:
746 	path_put(&exp.ex_path);
747 out1:
748 	auth_domain_put(dom);
749 out:
750 	kfree(buf);
751 	return err;
752 }
753 
754 static void exp_flags(struct seq_file *m, int flag, int fsid,
755 		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fslocs);
756 static void show_secinfo(struct seq_file *m, struct svc_export *exp);
757 
is_export_stats_file(struct seq_file * m)758 static int is_export_stats_file(struct seq_file *m)
759 {
760 	/*
761 	 * The export_stats file uses the same ops as the exports file.
762 	 * We use the file's name to determine the reported info per export.
763 	 * There is no rename in nsfdfs, so d_name.name is stable.
764 	 */
765 	return !strcmp(m->file->f_path.dentry->d_name.name, "export_stats");
766 }
767 
svc_export_show(struct seq_file * m,struct cache_detail * cd,struct cache_head * h)768 static int svc_export_show(struct seq_file *m,
769 			   struct cache_detail *cd,
770 			   struct cache_head *h)
771 {
772 	struct svc_export *exp;
773 	bool export_stats = is_export_stats_file(m);
774 
775 	if (h == NULL) {
776 		if (export_stats)
777 			seq_puts(m, "#path domain start-time\n#\tstats\n");
778 		else
779 			seq_puts(m, "#path domain(flags)\n");
780 		return 0;
781 	}
782 	exp = container_of(h, struct svc_export, h);
783 	seq_path(m, &exp->ex_path, " \t\n\\");
784 	seq_putc(m, '\t');
785 	seq_escape(m, exp->ex_client->name, " \t\n\\");
786 	if (export_stats) {
787 		struct percpu_counter *counter = exp->ex_stats->counter;
788 
789 		seq_printf(m, "\t%lld\n", exp->ex_stats->start_time);
790 		seq_printf(m, "\tfh_stale: %lld\n",
791 			   percpu_counter_sum_positive(&counter[EXP_STATS_FH_STALE]));
792 		seq_printf(m, "\tio_read: %lld\n",
793 			   percpu_counter_sum_positive(&counter[EXP_STATS_IO_READ]));
794 		seq_printf(m, "\tio_write: %lld\n",
795 			   percpu_counter_sum_positive(&counter[EXP_STATS_IO_WRITE]));
796 		seq_putc(m, '\n');
797 		return 0;
798 	}
799 	seq_putc(m, '(');
800 	if (test_bit(CACHE_VALID, &h->flags) &&
801 	    !test_bit(CACHE_NEGATIVE, &h->flags)) {
802 		exp_flags(m, exp->ex_flags, exp->ex_fsid,
803 			  exp->ex_anon_uid, exp->ex_anon_gid, &exp->ex_fslocs);
804 		if (exp->ex_uuid) {
805 			int i;
806 			seq_puts(m, ",uuid=");
807 			for (i = 0; i < EX_UUID_LEN; i++) {
808 				if ((i&3) == 0 && i)
809 					seq_putc(m, ':');
810 				seq_printf(m, "%02x", exp->ex_uuid[i]);
811 			}
812 		}
813 		show_secinfo(m, exp);
814 	}
815 	seq_puts(m, ")\n");
816 	return 0;
817 }
svc_export_match(struct cache_head * a,struct cache_head * b)818 static int svc_export_match(struct cache_head *a, struct cache_head *b)
819 {
820 	struct svc_export *orig = container_of(a, struct svc_export, h);
821 	struct svc_export *new = container_of(b, struct svc_export, h);
822 	return orig->ex_client == new->ex_client &&
823 		path_equal(&orig->ex_path, &new->ex_path);
824 }
825 
svc_export_init(struct cache_head * cnew,struct cache_head * citem)826 static void svc_export_init(struct cache_head *cnew, struct cache_head *citem)
827 {
828 	struct svc_export *new = container_of(cnew, struct svc_export, h);
829 	struct svc_export *item = container_of(citem, struct svc_export, h);
830 
831 	kref_get(&item->ex_client->ref);
832 	new->ex_client = item->ex_client;
833 	new->ex_path = item->ex_path;
834 	path_get(&item->ex_path);
835 	new->ex_fslocs.locations = NULL;
836 	new->ex_fslocs.locations_count = 0;
837 	new->ex_fslocs.migrated = 0;
838 	new->ex_layout_types = 0;
839 	new->ex_uuid = NULL;
840 	new->cd = item->cd;
841 	export_stats_reset(new->ex_stats);
842 }
843 
export_update(struct cache_head * cnew,struct cache_head * citem)844 static void export_update(struct cache_head *cnew, struct cache_head *citem)
845 {
846 	struct svc_export *new = container_of(cnew, struct svc_export, h);
847 	struct svc_export *item = container_of(citem, struct svc_export, h);
848 	int i;
849 
850 	new->ex_flags = item->ex_flags;
851 	new->ex_anon_uid = item->ex_anon_uid;
852 	new->ex_anon_gid = item->ex_anon_gid;
853 	new->ex_fsid = item->ex_fsid;
854 	new->ex_devid_map = item->ex_devid_map;
855 	item->ex_devid_map = NULL;
856 	new->ex_uuid = item->ex_uuid;
857 	item->ex_uuid = NULL;
858 	new->ex_fslocs.locations = item->ex_fslocs.locations;
859 	item->ex_fslocs.locations = NULL;
860 	new->ex_fslocs.locations_count = item->ex_fslocs.locations_count;
861 	item->ex_fslocs.locations_count = 0;
862 	new->ex_fslocs.migrated = item->ex_fslocs.migrated;
863 	item->ex_fslocs.migrated = 0;
864 	new->ex_layout_types = item->ex_layout_types;
865 	new->ex_nflavors = item->ex_nflavors;
866 	for (i = 0; i < MAX_SECINFO_LIST; i++) {
867 		new->ex_flavors[i] = item->ex_flavors[i];
868 	}
869 	new->ex_xprtsec_modes = item->ex_xprtsec_modes;
870 }
871 
svc_export_alloc(void)872 static struct cache_head *svc_export_alloc(void)
873 {
874 	struct svc_export *i = kmalloc(sizeof(*i), GFP_KERNEL);
875 	if (!i)
876 		return NULL;
877 
878 	i->ex_stats = kmalloc(sizeof(*(i->ex_stats)), GFP_KERNEL);
879 	if (!i->ex_stats) {
880 		kfree(i);
881 		return NULL;
882 	}
883 
884 	if (export_stats_init(i->ex_stats)) {
885 		kfree(i->ex_stats);
886 		kfree(i);
887 		return NULL;
888 	}
889 
890 	return &i->h;
891 }
892 
893 static const struct cache_detail svc_export_cache_template = {
894 	.owner		= THIS_MODULE,
895 	.hash_size	= EXPORT_HASHMAX,
896 	.name		= "nfsd.export",
897 	.cache_put	= svc_export_put,
898 	.cache_upcall	= svc_export_upcall,
899 	.cache_request	= svc_export_request,
900 	.cache_parse	= svc_export_parse,
901 	.cache_show	= svc_export_show,
902 	.match		= svc_export_match,
903 	.init		= svc_export_init,
904 	.update		= export_update,
905 	.alloc		= svc_export_alloc,
906 };
907 
908 static int
svc_export_hash(struct svc_export * exp)909 svc_export_hash(struct svc_export *exp)
910 {
911 	int hash;
912 
913 	hash = hash_ptr(exp->ex_client, EXPORT_HASHBITS);
914 	hash ^= hash_ptr(exp->ex_path.dentry, EXPORT_HASHBITS);
915 	hash ^= hash_ptr(exp->ex_path.mnt, EXPORT_HASHBITS);
916 	return hash;
917 }
918 
919 static struct svc_export *
svc_export_lookup(struct svc_export * exp)920 svc_export_lookup(struct svc_export *exp)
921 {
922 	struct cache_head *ch;
923 	int hash = svc_export_hash(exp);
924 
925 	ch = sunrpc_cache_lookup_rcu(exp->cd, &exp->h, hash);
926 	if (ch)
927 		return container_of(ch, struct svc_export, h);
928 	else
929 		return NULL;
930 }
931 
932 static struct svc_export *
svc_export_update(struct svc_export * new,struct svc_export * old)933 svc_export_update(struct svc_export *new, struct svc_export *old)
934 {
935 	struct cache_head *ch;
936 	int hash = svc_export_hash(old);
937 
938 	ch = sunrpc_cache_update(old->cd, &new->h, &old->h, hash);
939 	if (ch)
940 		return container_of(ch, struct svc_export, h);
941 	else
942 		return NULL;
943 }
944 
945 
946 static struct svc_expkey *
exp_find_key(struct cache_detail * cd,struct auth_domain * clp,int fsid_type,u32 * fsidv,struct cache_req * reqp)947 exp_find_key(struct cache_detail *cd, struct auth_domain *clp, int fsid_type,
948 	     u32 *fsidv, struct cache_req *reqp)
949 {
950 	struct svc_expkey key, *ek;
951 	int err;
952 
953 	if (!clp)
954 		return ERR_PTR(-ENOENT);
955 
956 	key.ek_client = clp;
957 	key.ek_fsidtype = fsid_type;
958 	memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
959 
960 	ek = svc_expkey_lookup(cd, &key);
961 	if (ek == NULL)
962 		return ERR_PTR(-ENOMEM);
963 	err = cache_check(cd, &ek->h, reqp);
964 	if (err) {
965 		trace_nfsd_exp_find_key(&key, err);
966 		return ERR_PTR(err);
967 	}
968 	return ek;
969 }
970 
971 static struct svc_export *
exp_get_by_name(struct cache_detail * cd,struct auth_domain * clp,const struct path * path,struct cache_req * reqp)972 exp_get_by_name(struct cache_detail *cd, struct auth_domain *clp,
973 		const struct path *path, struct cache_req *reqp)
974 {
975 	struct svc_export *exp, key;
976 	int err;
977 
978 	if (!clp)
979 		return ERR_PTR(-ENOENT);
980 
981 	key.ex_client = clp;
982 	key.ex_path = *path;
983 	key.cd = cd;
984 
985 	exp = svc_export_lookup(&key);
986 	if (exp == NULL)
987 		return ERR_PTR(-ENOMEM);
988 	err = cache_check(cd, &exp->h, reqp);
989 	if (err) {
990 		trace_nfsd_exp_get_by_name(&key, err);
991 		return ERR_PTR(err);
992 	}
993 	return exp;
994 }
995 
996 /*
997  * Find the export entry for a given dentry.
998  */
999 static struct svc_export *
exp_parent(struct cache_detail * cd,struct auth_domain * clp,struct path * path)1000 exp_parent(struct cache_detail *cd, struct auth_domain *clp, struct path *path)
1001 {
1002 	struct dentry *saved = dget(path->dentry);
1003 	struct svc_export *exp = exp_get_by_name(cd, clp, path, NULL);
1004 
1005 	while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
1006 		struct dentry *parent = dget_parent(path->dentry);
1007 		dput(path->dentry);
1008 		path->dentry = parent;
1009 		exp = exp_get_by_name(cd, clp, path, NULL);
1010 	}
1011 	dput(path->dentry);
1012 	path->dentry = saved;
1013 	return exp;
1014 }
1015 
1016 
1017 
1018 /*
1019  * Obtain the root fh on behalf of a client.
1020  * This could be done in user space, but I feel that it adds some safety
1021  * since its harder to fool a kernel module than a user space program.
1022  */
1023 int
exp_rootfh(struct net * net,struct auth_domain * clp,char * name,struct knfsd_fh * f,int maxsize)1024 exp_rootfh(struct net *net, struct auth_domain *clp, char *name,
1025 	   struct knfsd_fh *f, int maxsize)
1026 {
1027 	struct svc_export	*exp;
1028 	struct path		path;
1029 	struct inode		*inode;
1030 	struct svc_fh		fh;
1031 	int			err;
1032 	struct nfsd_net		*nn = net_generic(net, nfsd_net_id);
1033 	struct cache_detail	*cd = nn->svc_export_cache;
1034 
1035 	err = -EPERM;
1036 	/* NB: we probably ought to check that it's NUL-terminated */
1037 	if (kern_path(name, 0, &path)) {
1038 		printk("nfsd: exp_rootfh path not found %s", name);
1039 		return err;
1040 	}
1041 	inode = d_inode(path.dentry);
1042 
1043 	dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
1044 		 name, path.dentry, clp->name,
1045 		 inode->i_sb->s_id, inode->i_ino);
1046 	exp = exp_parent(cd, clp, &path);
1047 	if (IS_ERR(exp)) {
1048 		err = PTR_ERR(exp);
1049 		goto out;
1050 	}
1051 
1052 	/*
1053 	 * fh must be initialized before calling fh_compose
1054 	 */
1055 	fh_init(&fh, maxsize);
1056 	if (fh_compose(&fh, exp, path.dentry, NULL))
1057 		err = -EINVAL;
1058 	else
1059 		err = 0;
1060 	memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
1061 	fh_put(&fh);
1062 	exp_put(exp);
1063 out:
1064 	path_put(&path);
1065 	return err;
1066 }
1067 
exp_find(struct cache_detail * cd,struct auth_domain * clp,int fsid_type,u32 * fsidv,struct cache_req * reqp)1068 static struct svc_export *exp_find(struct cache_detail *cd,
1069 				   struct auth_domain *clp, int fsid_type,
1070 				   u32 *fsidv, struct cache_req *reqp)
1071 {
1072 	struct svc_export *exp;
1073 	struct nfsd_net *nn = net_generic(cd->net, nfsd_net_id);
1074 	struct svc_expkey *ek = exp_find_key(nn->svc_expkey_cache, clp, fsid_type, fsidv, reqp);
1075 	if (IS_ERR(ek))
1076 		return ERR_CAST(ek);
1077 
1078 	exp = exp_get_by_name(cd, clp, &ek->ek_path, reqp);
1079 	cache_put(&ek->h, nn->svc_expkey_cache);
1080 
1081 	if (IS_ERR(exp))
1082 		return ERR_CAST(exp);
1083 	return exp;
1084 }
1085 
1086 /**
1087  * check_nfsd_access - check if access to export is allowed.
1088  * @exp: svc_export that is being accessed.
1089  * @rqstp: svc_rqst attempting to access @exp (will be NULL for LOCALIO).
1090  * @may_bypass_gss: reduce strictness of authorization check
1091  *
1092  * Return values:
1093  *   %nfs_ok if access is granted, or
1094  *   %nfserr_wrongsec if access is denied
1095  */
check_nfsd_access(struct svc_export * exp,struct svc_rqst * rqstp,bool may_bypass_gss)1096 __be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp,
1097 			 bool may_bypass_gss)
1098 {
1099 	struct exp_flavor_info *f, *end = exp->ex_flavors + exp->ex_nflavors;
1100 	struct svc_xprt *xprt;
1101 
1102 	/*
1103 	 * If rqstp is NULL, this is a LOCALIO request which will only
1104 	 * ever use a filehandle/credential pair for which access has
1105 	 * been affirmed (by ACCESS or OPEN NFS requests) over the
1106 	 * wire. So there is no need for further checks here.
1107 	 */
1108 	if (!rqstp)
1109 		return nfs_ok;
1110 
1111 	xprt = rqstp->rq_xprt;
1112 
1113 	if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_NONE) {
1114 		if (!test_bit(XPT_TLS_SESSION, &xprt->xpt_flags))
1115 			goto ok;
1116 	}
1117 	if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_TLS) {
1118 		if (test_bit(XPT_TLS_SESSION, &xprt->xpt_flags) &&
1119 		    !test_bit(XPT_PEER_AUTH, &xprt->xpt_flags))
1120 			goto ok;
1121 	}
1122 	if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_MTLS) {
1123 		if (test_bit(XPT_TLS_SESSION, &xprt->xpt_flags) &&
1124 		    test_bit(XPT_PEER_AUTH, &xprt->xpt_flags))
1125 			goto ok;
1126 	}
1127 	goto denied;
1128 
1129 ok:
1130 	/* legacy gss-only clients are always OK: */
1131 	if (exp->ex_client == rqstp->rq_gssclient)
1132 		return nfs_ok;
1133 	/* ip-address based client; check sec= export option: */
1134 	for (f = exp->ex_flavors; f < end; f++) {
1135 		if (f->pseudoflavor == rqstp->rq_cred.cr_flavor)
1136 			return nfs_ok;
1137 	}
1138 	/* defaults in absence of sec= options: */
1139 	if (exp->ex_nflavors == 0) {
1140 		if (rqstp->rq_cred.cr_flavor == RPC_AUTH_NULL ||
1141 		    rqstp->rq_cred.cr_flavor == RPC_AUTH_UNIX)
1142 			return nfs_ok;
1143 	}
1144 
1145 	/* If the compound op contains a spo_must_allowed op,
1146 	 * it will be sent with integrity/protection which
1147 	 * will have to be expressly allowed on mounts that
1148 	 * don't support it
1149 	 */
1150 
1151 	if (nfsd4_spo_must_allow(rqstp))
1152 		return nfs_ok;
1153 
1154 	/* Some calls may be processed without authentication
1155 	 * on GSS exports. For example NFS2/3 calls on root
1156 	 * directory, see section 2.3.2 of rfc 2623.
1157 	 * For "may_bypass_gss" check that export has really
1158 	 * enabled some flavor with authentication (GSS or any
1159 	 * other) and also check that the used auth flavor is
1160 	 * without authentication (none or sys).
1161 	 */
1162 	if (may_bypass_gss && (
1163 	     rqstp->rq_cred.cr_flavor == RPC_AUTH_NULL ||
1164 	     rqstp->rq_cred.cr_flavor == RPC_AUTH_UNIX)) {
1165 		for (f = exp->ex_flavors; f < end; f++) {
1166 			if (f->pseudoflavor >= RPC_AUTH_DES)
1167 				return 0;
1168 		}
1169 	}
1170 
1171 denied:
1172 	return nfserr_wrongsec;
1173 }
1174 
1175 /*
1176  * Uses rq_client and rq_gssclient to find an export; uses rq_client (an
1177  * auth_unix client) if it's available and has secinfo information;
1178  * otherwise, will try to use rq_gssclient.
1179  *
1180  * Called from functions that handle requests; functions that do work on
1181  * behalf of mountd are passed a single client name to use, and should
1182  * use exp_get_by_name() or exp_find().
1183  */
1184 struct svc_export *
rqst_exp_get_by_name(struct svc_rqst * rqstp,struct path * path)1185 rqst_exp_get_by_name(struct svc_rqst *rqstp, struct path *path)
1186 {
1187 	struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
1188 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1189 	struct cache_detail *cd = nn->svc_export_cache;
1190 
1191 	if (rqstp->rq_client == NULL)
1192 		goto gss;
1193 
1194 	/* First try the auth_unix client: */
1195 	exp = exp_get_by_name(cd, rqstp->rq_client, path, &rqstp->rq_chandle);
1196 	if (PTR_ERR(exp) == -ENOENT)
1197 		goto gss;
1198 	if (IS_ERR(exp))
1199 		return exp;
1200 	/* If it has secinfo, assume there are no gss/... clients */
1201 	if (exp->ex_nflavors > 0)
1202 		return exp;
1203 gss:
1204 	/* Otherwise, try falling back on gss client */
1205 	if (rqstp->rq_gssclient == NULL)
1206 		return exp;
1207 	gssexp = exp_get_by_name(cd, rqstp->rq_gssclient, path, &rqstp->rq_chandle);
1208 	if (PTR_ERR(gssexp) == -ENOENT)
1209 		return exp;
1210 	if (!IS_ERR(exp))
1211 		exp_put(exp);
1212 	return gssexp;
1213 }
1214 
1215 /**
1216  * rqst_exp_find - Find an svc_export in the context of a rqst or similar
1217  * @reqp:	The handle to be used to suspend the request if a cache-upcall is needed
1218  *		If NULL, missing in-cache information will result in failure.
1219  * @net:	The network namespace in which the request exists
1220  * @cl:		default auth_domain to use for looking up the export
1221  * @gsscl:	an alternate auth_domain defined using deprecated gss/krb5 format.
1222  * @fsid_type:	The type of fsid to look for
1223  * @fsidv:	The actual fsid to look up in the context of either client.
1224  *
1225  * Perform a lookup for @cl/@fsidv in the given @net for an export.  If
1226  * none found and @gsscl specified, repeat the lookup.
1227  *
1228  * Returns an export, or an error pointer.
1229  */
1230 struct svc_export *
rqst_exp_find(struct cache_req * reqp,struct net * net,struct auth_domain * cl,struct auth_domain * gsscl,int fsid_type,u32 * fsidv)1231 rqst_exp_find(struct cache_req *reqp, struct net *net,
1232 	      struct auth_domain *cl, struct auth_domain *gsscl,
1233 	      int fsid_type, u32 *fsidv)
1234 {
1235 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1236 	struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
1237 	struct cache_detail *cd = nn->svc_export_cache;
1238 
1239 	if (!cl)
1240 		goto gss;
1241 
1242 	/* First try the auth_unix client: */
1243 	exp = exp_find(cd, cl, fsid_type, fsidv, reqp);
1244 	if (PTR_ERR(exp) == -ENOENT)
1245 		goto gss;
1246 	if (IS_ERR(exp))
1247 		return exp;
1248 	/* If it has secinfo, assume there are no gss/... clients */
1249 	if (exp->ex_nflavors > 0)
1250 		return exp;
1251 gss:
1252 	/* Otherwise, try falling back on gss client */
1253 	if (!gsscl)
1254 		return exp;
1255 	gssexp = exp_find(cd, gsscl, fsid_type, fsidv, reqp);
1256 	if (PTR_ERR(gssexp) == -ENOENT)
1257 		return exp;
1258 	if (!IS_ERR(exp))
1259 		exp_put(exp);
1260 	return gssexp;
1261 }
1262 
1263 struct svc_export *
rqst_exp_parent(struct svc_rqst * rqstp,struct path * path)1264 rqst_exp_parent(struct svc_rqst *rqstp, struct path *path)
1265 {
1266 	struct dentry *saved = dget(path->dentry);
1267 	struct svc_export *exp = rqst_exp_get_by_name(rqstp, path);
1268 
1269 	while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
1270 		struct dentry *parent = dget_parent(path->dentry);
1271 		dput(path->dentry);
1272 		path->dentry = parent;
1273 		exp = rqst_exp_get_by_name(rqstp, path);
1274 	}
1275 	dput(path->dentry);
1276 	path->dentry = saved;
1277 	return exp;
1278 }
1279 
rqst_find_fsidzero_export(struct svc_rqst * rqstp)1280 struct svc_export *rqst_find_fsidzero_export(struct svc_rqst *rqstp)
1281 {
1282 	u32 fsidv[2];
1283 
1284 	mk_fsid(FSID_NUM, fsidv, 0, 0, 0, NULL);
1285 
1286 	return rqst_exp_find(&rqstp->rq_chandle, SVC_NET(rqstp),
1287 			     rqstp->rq_client, rqstp->rq_gssclient,
1288 			     FSID_NUM, fsidv);
1289 }
1290 
1291 /*
1292  * Called when we need the filehandle for the root of the pseudofs,
1293  * for a given NFSv4 client.   The root is defined to be the
1294  * export point with fsid==0
1295  */
1296 __be32
exp_pseudoroot(struct svc_rqst * rqstp,struct svc_fh * fhp)1297 exp_pseudoroot(struct svc_rqst *rqstp, struct svc_fh *fhp)
1298 {
1299 	struct svc_export *exp;
1300 	__be32 rv;
1301 
1302 	exp = rqst_find_fsidzero_export(rqstp);
1303 	if (IS_ERR(exp))
1304 		return nfserrno(PTR_ERR(exp));
1305 	rv = fh_compose(fhp, exp, exp->ex_path.dentry, NULL);
1306 	exp_put(exp);
1307 	return rv;
1308 }
1309 
1310 static struct flags {
1311 	int flag;
1312 	char *name[2];
1313 } expflags[] = {
1314 	{ NFSEXP_READONLY, {"ro", "rw"}},
1315 	{ NFSEXP_INSECURE_PORT, {"insecure", ""}},
1316 	{ NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
1317 	{ NFSEXP_ALLSQUASH, {"all_squash", ""}},
1318 	{ NFSEXP_ASYNC, {"async", "sync"}},
1319 	{ NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
1320 	{ NFSEXP_NOREADDIRPLUS, {"nordirplus", ""}},
1321 	{ NFSEXP_NOHIDE, {"nohide", ""}},
1322 	{ NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
1323 	{ NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
1324 	{ NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
1325 	{ NFSEXP_V4ROOT, {"v4root", ""}},
1326 	{ NFSEXP_PNFS, {"pnfs", ""}},
1327 	{ NFSEXP_SECURITY_LABEL, {"security_label", ""}},
1328 	{ 0, {"", ""}}
1329 };
1330 
show_expflags(struct seq_file * m,int flags,int mask)1331 static void show_expflags(struct seq_file *m, int flags, int mask)
1332 {
1333 	struct flags *flg;
1334 	int state, first = 0;
1335 
1336 	for (flg = expflags; flg->flag; flg++) {
1337 		if (flg->flag & ~mask)
1338 			continue;
1339 		state = (flg->flag & flags) ? 0 : 1;
1340 		if (*flg->name[state])
1341 			seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
1342 	}
1343 }
1344 
show_secinfo_flags(struct seq_file * m,int flags)1345 static void show_secinfo_flags(struct seq_file *m, int flags)
1346 {
1347 	seq_printf(m, ",");
1348 	show_expflags(m, flags, NFSEXP_SECINFO_FLAGS);
1349 }
1350 
secinfo_flags_equal(int f,int g)1351 static bool secinfo_flags_equal(int f, int g)
1352 {
1353 	f &= NFSEXP_SECINFO_FLAGS;
1354 	g &= NFSEXP_SECINFO_FLAGS;
1355 	return f == g;
1356 }
1357 
show_secinfo_run(struct seq_file * m,struct exp_flavor_info ** fp,struct exp_flavor_info * end)1358 static int show_secinfo_run(struct seq_file *m, struct exp_flavor_info **fp, struct exp_flavor_info *end)
1359 {
1360 	int flags;
1361 
1362 	flags = (*fp)->flags;
1363 	seq_printf(m, ",sec=%d", (*fp)->pseudoflavor);
1364 	(*fp)++;
1365 	while (*fp != end && secinfo_flags_equal(flags, (*fp)->flags)) {
1366 		seq_printf(m, ":%d", (*fp)->pseudoflavor);
1367 		(*fp)++;
1368 	}
1369 	return flags;
1370 }
1371 
show_secinfo(struct seq_file * m,struct svc_export * exp)1372 static void show_secinfo(struct seq_file *m, struct svc_export *exp)
1373 {
1374 	struct exp_flavor_info *f;
1375 	struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
1376 	int flags;
1377 
1378 	if (exp->ex_nflavors == 0)
1379 		return;
1380 	f = exp->ex_flavors;
1381 	flags = show_secinfo_run(m, &f, end);
1382 	if (!secinfo_flags_equal(flags, exp->ex_flags))
1383 		show_secinfo_flags(m, flags);
1384 	while (f != end) {
1385 		flags = show_secinfo_run(m, &f, end);
1386 		show_secinfo_flags(m, flags);
1387 	}
1388 }
1389 
exp_flags(struct seq_file * m,int flag,int fsid,kuid_t anonu,kgid_t anong,struct nfsd4_fs_locations * fsloc)1390 static void exp_flags(struct seq_file *m, int flag, int fsid,
1391 		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fsloc)
1392 {
1393 	struct user_namespace *userns = m->file->f_cred->user_ns;
1394 
1395 	show_expflags(m, flag, NFSEXP_ALLFLAGS);
1396 	if (flag & NFSEXP_FSID)
1397 		seq_printf(m, ",fsid=%d", fsid);
1398 	if (!uid_eq(anonu, make_kuid(userns, (uid_t)-2)) &&
1399 	    !uid_eq(anonu, make_kuid(userns, 0x10000-2)))
1400 		seq_printf(m, ",anonuid=%u", from_kuid_munged(userns, anonu));
1401 	if (!gid_eq(anong, make_kgid(userns, (gid_t)-2)) &&
1402 	    !gid_eq(anong, make_kgid(userns, 0x10000-2)))
1403 		seq_printf(m, ",anongid=%u", from_kgid_munged(userns, anong));
1404 	if (fsloc && fsloc->locations_count > 0) {
1405 		char *loctype = (fsloc->migrated) ? "refer" : "replicas";
1406 		int i;
1407 
1408 		seq_printf(m, ",%s=", loctype);
1409 		seq_escape(m, fsloc->locations[0].path, ",;@ \t\n\\");
1410 		seq_putc(m, '@');
1411 		seq_escape(m, fsloc->locations[0].hosts, ",;@ \t\n\\");
1412 		for (i = 1; i < fsloc->locations_count; i++) {
1413 			seq_putc(m, ';');
1414 			seq_escape(m, fsloc->locations[i].path, ",;@ \t\n\\");
1415 			seq_putc(m, '@');
1416 			seq_escape(m, fsloc->locations[i].hosts, ",;@ \t\n\\");
1417 		}
1418 	}
1419 }
1420 
e_show(struct seq_file * m,void * p)1421 static int e_show(struct seq_file *m, void *p)
1422 {
1423 	struct cache_head *cp = p;
1424 	struct svc_export *exp = container_of(cp, struct svc_export, h);
1425 	struct cache_detail *cd = m->private;
1426 	bool export_stats = is_export_stats_file(m);
1427 
1428 	if (p == SEQ_START_TOKEN) {
1429 		seq_puts(m, "# Version 1.1\n");
1430 		if (export_stats)
1431 			seq_puts(m, "# Path Client Start-time\n#\tStats\n");
1432 		else
1433 			seq_puts(m, "# Path Client(Flags) # IPs\n");
1434 		return 0;
1435 	}
1436 
1437 	if (cache_check_rcu(cd, &exp->h, NULL))
1438 		return 0;
1439 
1440 	return svc_export_show(m, cd, cp);
1441 }
1442 
1443 const struct seq_operations nfs_exports_op = {
1444 	.start	= cache_seq_start_rcu,
1445 	.next	= cache_seq_next_rcu,
1446 	.stop	= cache_seq_stop_rcu,
1447 	.show	= e_show,
1448 };
1449 
1450 /*
1451  * Initialize the exports module.
1452  */
1453 int
nfsd_export_init(struct net * net)1454 nfsd_export_init(struct net *net)
1455 {
1456 	int rv;
1457 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1458 
1459 	dprintk("nfsd: initializing export module (net: %x).\n", net->ns.inum);
1460 
1461 	nn->svc_export_cache = cache_create_net(&svc_export_cache_template, net);
1462 	if (IS_ERR(nn->svc_export_cache))
1463 		return PTR_ERR(nn->svc_export_cache);
1464 	rv = cache_register_net(nn->svc_export_cache, net);
1465 	if (rv)
1466 		goto destroy_export_cache;
1467 
1468 	nn->svc_expkey_cache = cache_create_net(&svc_expkey_cache_template, net);
1469 	if (IS_ERR(nn->svc_expkey_cache)) {
1470 		rv = PTR_ERR(nn->svc_expkey_cache);
1471 		goto unregister_export_cache;
1472 	}
1473 	rv = cache_register_net(nn->svc_expkey_cache, net);
1474 	if (rv)
1475 		goto destroy_expkey_cache;
1476 	return 0;
1477 
1478 destroy_expkey_cache:
1479 	cache_destroy_net(nn->svc_expkey_cache, net);
1480 unregister_export_cache:
1481 	cache_unregister_net(nn->svc_export_cache, net);
1482 destroy_export_cache:
1483 	cache_destroy_net(nn->svc_export_cache, net);
1484 	return rv;
1485 }
1486 
1487 /*
1488  * Flush exports table - called when last nfsd thread is killed
1489  */
1490 void
nfsd_export_flush(struct net * net)1491 nfsd_export_flush(struct net *net)
1492 {
1493 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1494 
1495 	cache_purge(nn->svc_expkey_cache);
1496 	cache_purge(nn->svc_export_cache);
1497 }
1498 
1499 /*
1500  * Shutdown the exports module.
1501  */
1502 void
nfsd_export_shutdown(struct net * net)1503 nfsd_export_shutdown(struct net *net)
1504 {
1505 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1506 
1507 	dprintk("nfsd: shutting down export module (net: %x).\n", net->ns.inum);
1508 
1509 	cache_unregister_net(nn->svc_expkey_cache, net);
1510 	cache_unregister_net(nn->svc_export_cache, net);
1511 	cache_destroy_net(nn->svc_expkey_cache, net);
1512 	cache_destroy_net(nn->svc_export_cache, net);
1513 	svcauth_unix_purge(net);
1514 
1515 	dprintk("nfsd: export shutdown complete (net: %x).\n", net->ns.inum);
1516 }
1517