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 nfsd_percpu_counters_init(stats->counter, EXP_STATS_COUNTERS_NUM);
338 }
339 
export_stats_reset(struct export_stats * stats)340 static void export_stats_reset(struct export_stats *stats)
341 {
342 	nfsd_percpu_counters_reset(stats->counter, EXP_STATS_COUNTERS_NUM);
343 }
344 
export_stats_destroy(struct export_stats * stats)345 static void export_stats_destroy(struct export_stats *stats)
346 {
347 	nfsd_percpu_counters_destroy(stats->counter, EXP_STATS_COUNTERS_NUM);
348 }
349 
svc_export_put(struct kref * ref)350 static void svc_export_put(struct kref *ref)
351 {
352 	struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
353 	path_put(&exp->ex_path);
354 	auth_domain_put(exp->ex_client);
355 	nfsd4_fslocs_free(&exp->ex_fslocs);
356 	export_stats_destroy(&exp->ex_stats);
357 	kfree(exp->ex_uuid);
358 	kfree_rcu(exp, ex_rcu);
359 }
360 
svc_export_upcall(struct cache_detail * cd,struct cache_head * h)361 static int svc_export_upcall(struct cache_detail *cd, struct cache_head *h)
362 {
363 	return sunrpc_cache_pipe_upcall(cd, h);
364 }
365 
svc_export_request(struct cache_detail * cd,struct cache_head * h,char ** bpp,int * blen)366 static void svc_export_request(struct cache_detail *cd,
367 			       struct cache_head *h,
368 			       char **bpp, int *blen)
369 {
370 	/*  client path */
371 	struct svc_export *exp = container_of(h, struct svc_export, h);
372 	char *pth;
373 
374 	qword_add(bpp, blen, exp->ex_client->name);
375 	pth = d_path(&exp->ex_path, *bpp, *blen);
376 	if (IS_ERR(pth)) {
377 		/* is this correct? */
378 		(*bpp)[0] = '\n';
379 		return;
380 	}
381 	qword_add(bpp, blen, pth);
382 	(*bpp)[-1] = '\n';
383 }
384 
385 static struct svc_export *svc_export_update(struct svc_export *new,
386 					    struct svc_export *old);
387 static struct svc_export *svc_export_lookup(struct svc_export *);
388 
check_export(struct path * path,int * flags,unsigned char * uuid)389 static int check_export(struct path *path, int *flags, unsigned char *uuid)
390 {
391 	struct inode *inode = d_inode(path->dentry);
392 
393 	/*
394 	 * We currently export only dirs, regular files, and (for v4
395 	 * pseudoroot) symlinks.
396 	 */
397 	if (!S_ISDIR(inode->i_mode) &&
398 	    !S_ISLNK(inode->i_mode) &&
399 	    !S_ISREG(inode->i_mode))
400 		return -ENOTDIR;
401 
402 	/*
403 	 * Mountd should never pass down a writeable V4ROOT export, but,
404 	 * just to make sure:
405 	 */
406 	if (*flags & NFSEXP_V4ROOT)
407 		*flags |= NFSEXP_READONLY;
408 
409 	/* There are two requirements on a filesystem to be exportable.
410 	 * 1:  We must be able to identify the filesystem from a number.
411 	 *       either a device number (so FS_REQUIRES_DEV needed)
412 	 *       or an FSID number (so NFSEXP_FSID or ->uuid is needed).
413 	 * 2:  We must be able to find an inode from a filehandle.
414 	 *       This means that s_export_op must be set.
415 	 * 3: We must not currently be on an idmapped mount.
416 	 */
417 	if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) &&
418 	    !(*flags & NFSEXP_FSID) &&
419 	    uuid == NULL) {
420 		dprintk("exp_export: export of non-dev fs without fsid\n");
421 		return -EINVAL;
422 	}
423 
424 	if (!inode->i_sb->s_export_op ||
425 	    !inode->i_sb->s_export_op->fh_to_dentry) {
426 		dprintk("exp_export: export of invalid fs type.\n");
427 		return -EINVAL;
428 	}
429 
430 	if (is_idmapped_mnt(path->mnt)) {
431 		dprintk("exp_export: export of idmapped mounts not yet supported.\n");
432 		return -EINVAL;
433 	}
434 
435 	if (inode->i_sb->s_export_op->flags & EXPORT_OP_NOSUBTREECHK &&
436 	    !(*flags & NFSEXP_NOSUBTREECHECK)) {
437 		dprintk("%s: %s does not support subtree checking!\n",
438 			__func__, inode->i_sb->s_type->name);
439 		return -EINVAL;
440 	}
441 	return 0;
442 }
443 
444 #ifdef CONFIG_NFSD_V4
445 
446 static int
fsloc_parse(char ** mesg,char * buf,struct nfsd4_fs_locations * fsloc)447 fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc)
448 {
449 	int len;
450 	int migrated, i, err;
451 
452 	/* more than one fsloc */
453 	if (fsloc->locations)
454 		return -EINVAL;
455 
456 	/* listsize */
457 	err = get_uint(mesg, &fsloc->locations_count);
458 	if (err)
459 		return err;
460 	if (fsloc->locations_count > MAX_FS_LOCATIONS)
461 		return -EINVAL;
462 	if (fsloc->locations_count == 0)
463 		return 0;
464 
465 	fsloc->locations = kcalloc(fsloc->locations_count,
466 				   sizeof(struct nfsd4_fs_location),
467 				   GFP_KERNEL);
468 	if (!fsloc->locations)
469 		return -ENOMEM;
470 	for (i=0; i < fsloc->locations_count; i++) {
471 		/* colon separated host list */
472 		err = -EINVAL;
473 		len = qword_get(mesg, buf, PAGE_SIZE);
474 		if (len <= 0)
475 			goto out_free_all;
476 		err = -ENOMEM;
477 		fsloc->locations[i].hosts = kstrdup(buf, GFP_KERNEL);
478 		if (!fsloc->locations[i].hosts)
479 			goto out_free_all;
480 		err = -EINVAL;
481 		/* slash separated path component list */
482 		len = qword_get(mesg, buf, PAGE_SIZE);
483 		if (len <= 0)
484 			goto out_free_all;
485 		err = -ENOMEM;
486 		fsloc->locations[i].path = kstrdup(buf, GFP_KERNEL);
487 		if (!fsloc->locations[i].path)
488 			goto out_free_all;
489 	}
490 	/* migrated */
491 	err = get_int(mesg, &migrated);
492 	if (err)
493 		goto out_free_all;
494 	err = -EINVAL;
495 	if (migrated < 0 || migrated > 1)
496 		goto out_free_all;
497 	fsloc->migrated = migrated;
498 	return 0;
499 out_free_all:
500 	nfsd4_fslocs_free(fsloc);
501 	return err;
502 }
503 
secinfo_parse(char ** mesg,char * buf,struct svc_export * exp)504 static int secinfo_parse(char **mesg, char *buf, struct svc_export *exp)
505 {
506 	struct exp_flavor_info *f;
507 	u32 listsize;
508 	int err;
509 
510 	/* more than one secinfo */
511 	if (exp->ex_nflavors)
512 		return -EINVAL;
513 
514 	err = get_uint(mesg, &listsize);
515 	if (err)
516 		return err;
517 	if (listsize > MAX_SECINFO_LIST)
518 		return -EINVAL;
519 
520 	for (f = exp->ex_flavors; f < exp->ex_flavors + listsize; f++) {
521 		err = get_uint(mesg, &f->pseudoflavor);
522 		if (err)
523 			return err;
524 		/*
525 		 * XXX: It would be nice to also check whether this
526 		 * pseudoflavor is supported, so we can discover the
527 		 * problem at export time instead of when a client fails
528 		 * to authenticate.
529 		 */
530 		err = get_uint(mesg, &f->flags);
531 		if (err)
532 			return err;
533 		/* Only some flags are allowed to differ between flavors: */
534 		if (~NFSEXP_SECINFO_FLAGS & (f->flags ^ exp->ex_flags))
535 			return -EINVAL;
536 	}
537 	exp->ex_nflavors = listsize;
538 	return 0;
539 }
540 
541 #else /* CONFIG_NFSD_V4 */
542 static inline int
fsloc_parse(char ** mesg,char * buf,struct nfsd4_fs_locations * fsloc)543 fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc){return 0;}
544 static inline int
secinfo_parse(char ** mesg,char * buf,struct svc_export * exp)545 secinfo_parse(char **mesg, char *buf, struct svc_export *exp) { return 0; }
546 #endif
547 
xprtsec_parse(char ** mesg,char * buf,struct svc_export * exp)548 static int xprtsec_parse(char **mesg, char *buf, struct svc_export *exp)
549 {
550 	unsigned int i, mode, listsize;
551 	int err;
552 
553 	err = get_uint(mesg, &listsize);
554 	if (err)
555 		return err;
556 	if (listsize > NFSEXP_XPRTSEC_NUM)
557 		return -EINVAL;
558 
559 	exp->ex_xprtsec_modes = 0;
560 	for (i = 0; i < listsize; i++) {
561 		err = get_uint(mesg, &mode);
562 		if (err)
563 			return err;
564 		if (mode > NFSEXP_XPRTSEC_MTLS)
565 			return -EINVAL;
566 		exp->ex_xprtsec_modes |= mode;
567 	}
568 	return 0;
569 }
570 
571 static inline int
nfsd_uuid_parse(char ** mesg,char * buf,unsigned char ** puuid)572 nfsd_uuid_parse(char **mesg, char *buf, unsigned char **puuid)
573 {
574 	int len;
575 
576 	/* more than one uuid */
577 	if (*puuid)
578 		return -EINVAL;
579 
580 	/* expect a 16 byte uuid encoded as \xXXXX... */
581 	len = qword_get(mesg, buf, PAGE_SIZE);
582 	if (len != EX_UUID_LEN)
583 		return -EINVAL;
584 
585 	*puuid = kmemdup(buf, EX_UUID_LEN, GFP_KERNEL);
586 	if (*puuid == NULL)
587 		return -ENOMEM;
588 
589 	return 0;
590 }
591 
svc_export_parse(struct cache_detail * cd,char * mesg,int mlen)592 static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
593 {
594 	/* client path expiry [flags anonuid anongid fsid] */
595 	char *buf;
596 	int err;
597 	struct auth_domain *dom = NULL;
598 	struct svc_export exp = {}, *expp;
599 	int an_int;
600 
601 	if (mesg[mlen-1] != '\n')
602 		return -EINVAL;
603 	mesg[mlen-1] = 0;
604 
605 	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
606 	if (!buf)
607 		return -ENOMEM;
608 
609 	/* client */
610 	err = -EINVAL;
611 	if (qword_get(&mesg, buf, PAGE_SIZE) <= 0)
612 		goto out;
613 
614 	err = -ENOENT;
615 	dom = auth_domain_find(buf);
616 	if (!dom)
617 		goto out;
618 
619 	/* path */
620 	err = -EINVAL;
621 	if (qword_get(&mesg, buf, PAGE_SIZE) <= 0)
622 		goto out1;
623 
624 	err = kern_path(buf, 0, &exp.ex_path);
625 	if (err)
626 		goto out1;
627 
628 	exp.ex_client = dom;
629 	exp.cd = cd;
630 	exp.ex_devid_map = NULL;
631 	exp.ex_xprtsec_modes = NFSEXP_XPRTSEC_ALL;
632 
633 	/* expiry */
634 	err = get_expiry(&mesg, &exp.h.expiry_time);
635 	if (err)
636 		goto out3;
637 
638 	/* flags */
639 	err = get_int(&mesg, &an_int);
640 	if (err == -ENOENT) {
641 		err = 0;
642 		set_bit(CACHE_NEGATIVE, &exp.h.flags);
643 	} else {
644 		if (err || an_int < 0)
645 			goto out3;
646 		exp.ex_flags= an_int;
647 
648 		/* anon uid */
649 		err = get_int(&mesg, &an_int);
650 		if (err)
651 			goto out3;
652 		exp.ex_anon_uid= make_kuid(current_user_ns(), an_int);
653 
654 		/* anon gid */
655 		err = get_int(&mesg, &an_int);
656 		if (err)
657 			goto out3;
658 		exp.ex_anon_gid= make_kgid(current_user_ns(), an_int);
659 
660 		/* fsid */
661 		err = get_int(&mesg, &an_int);
662 		if (err)
663 			goto out3;
664 		exp.ex_fsid = an_int;
665 
666 		while (qword_get(&mesg, buf, PAGE_SIZE) > 0) {
667 			if (strcmp(buf, "fsloc") == 0)
668 				err = fsloc_parse(&mesg, buf, &exp.ex_fslocs);
669 			else if (strcmp(buf, "uuid") == 0)
670 				err = nfsd_uuid_parse(&mesg, buf, &exp.ex_uuid);
671 			else if (strcmp(buf, "secinfo") == 0)
672 				err = secinfo_parse(&mesg, buf, &exp);
673 			else if (strcmp(buf, "xprtsec") == 0)
674 				err = xprtsec_parse(&mesg, buf, &exp);
675 			else
676 				/* quietly ignore unknown words and anything
677 				 * following. Newer user-space can try to set
678 				 * new values, then see what the result was.
679 				 */
680 				break;
681 			if (err)
682 				goto out4;
683 		}
684 
685 		err = check_export(&exp.ex_path, &exp.ex_flags, exp.ex_uuid);
686 		if (err)
687 			goto out4;
688 
689 		/*
690 		 * No point caching this if it would immediately expire.
691 		 * Also, this protects exportfs's dummy export from the
692 		 * anon_uid/anon_gid checks:
693 		 */
694 		if (exp.h.expiry_time < seconds_since_boot())
695 			goto out4;
696 		/*
697 		 * For some reason exportfs has been passing down an
698 		 * invalid (-1) uid & gid on the "dummy" export which it
699 		 * uses to test export support.  To make sure exportfs
700 		 * sees errors from check_export we therefore need to
701 		 * delay these checks till after check_export:
702 		 */
703 		err = -EINVAL;
704 		if (!uid_valid(exp.ex_anon_uid))
705 			goto out4;
706 		if (!gid_valid(exp.ex_anon_gid))
707 			goto out4;
708 		err = 0;
709 
710 		nfsd4_setup_layout_type(&exp);
711 	}
712 
713 	expp = svc_export_lookup(&exp);
714 	if (!expp) {
715 		err = -ENOMEM;
716 		goto out4;
717 	}
718 	expp = svc_export_update(&exp, expp);
719 	if (expp) {
720 		trace_nfsd_export_update(expp);
721 		cache_flush();
722 		exp_put(expp);
723 	} else
724 		err = -ENOMEM;
725 out4:
726 	nfsd4_fslocs_free(&exp.ex_fslocs);
727 	kfree(exp.ex_uuid);
728 out3:
729 	path_put(&exp.ex_path);
730 out1:
731 	auth_domain_put(dom);
732 out:
733 	kfree(buf);
734 	return err;
735 }
736 
737 static void exp_flags(struct seq_file *m, int flag, int fsid,
738 		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fslocs);
739 static void show_secinfo(struct seq_file *m, struct svc_export *exp);
740 
is_export_stats_file(struct seq_file * m)741 static int is_export_stats_file(struct seq_file *m)
742 {
743 	/*
744 	 * The export_stats file uses the same ops as the exports file.
745 	 * We use the file's name to determine the reported info per export.
746 	 * There is no rename in nsfdfs, so d_name.name is stable.
747 	 */
748 	return !strcmp(m->file->f_path.dentry->d_name.name, "export_stats");
749 }
750 
svc_export_show(struct seq_file * m,struct cache_detail * cd,struct cache_head * h)751 static int svc_export_show(struct seq_file *m,
752 			   struct cache_detail *cd,
753 			   struct cache_head *h)
754 {
755 	struct svc_export *exp;
756 	bool export_stats = is_export_stats_file(m);
757 
758 	if (h == NULL) {
759 		if (export_stats)
760 			seq_puts(m, "#path domain start-time\n#\tstats\n");
761 		else
762 			seq_puts(m, "#path domain(flags)\n");
763 		return 0;
764 	}
765 	exp = container_of(h, struct svc_export, h);
766 	seq_path(m, &exp->ex_path, " \t\n\\");
767 	seq_putc(m, '\t');
768 	seq_escape(m, exp->ex_client->name, " \t\n\\");
769 	if (export_stats) {
770 		seq_printf(m, "\t%lld\n", exp->ex_stats.start_time);
771 		seq_printf(m, "\tfh_stale: %lld\n",
772 			   percpu_counter_sum_positive(&exp->ex_stats.counter[EXP_STATS_FH_STALE]));
773 		seq_printf(m, "\tio_read: %lld\n",
774 			   percpu_counter_sum_positive(&exp->ex_stats.counter[EXP_STATS_IO_READ]));
775 		seq_printf(m, "\tio_write: %lld\n",
776 			   percpu_counter_sum_positive(&exp->ex_stats.counter[EXP_STATS_IO_WRITE]));
777 		seq_putc(m, '\n');
778 		return 0;
779 	}
780 	seq_putc(m, '(');
781 	if (test_bit(CACHE_VALID, &h->flags) &&
782 	    !test_bit(CACHE_NEGATIVE, &h->flags)) {
783 		exp_flags(m, exp->ex_flags, exp->ex_fsid,
784 			  exp->ex_anon_uid, exp->ex_anon_gid, &exp->ex_fslocs);
785 		if (exp->ex_uuid) {
786 			int i;
787 			seq_puts(m, ",uuid=");
788 			for (i = 0; i < EX_UUID_LEN; i++) {
789 				if ((i&3) == 0 && i)
790 					seq_putc(m, ':');
791 				seq_printf(m, "%02x", exp->ex_uuid[i]);
792 			}
793 		}
794 		show_secinfo(m, exp);
795 	}
796 	seq_puts(m, ")\n");
797 	return 0;
798 }
svc_export_match(struct cache_head * a,struct cache_head * b)799 static int svc_export_match(struct cache_head *a, struct cache_head *b)
800 {
801 	struct svc_export *orig = container_of(a, struct svc_export, h);
802 	struct svc_export *new = container_of(b, struct svc_export, h);
803 	return orig->ex_client == new->ex_client &&
804 		path_equal(&orig->ex_path, &new->ex_path);
805 }
806 
svc_export_init(struct cache_head * cnew,struct cache_head * citem)807 static void svc_export_init(struct cache_head *cnew, struct cache_head *citem)
808 {
809 	struct svc_export *new = container_of(cnew, struct svc_export, h);
810 	struct svc_export *item = container_of(citem, struct svc_export, h);
811 
812 	kref_get(&item->ex_client->ref);
813 	new->ex_client = item->ex_client;
814 	new->ex_path = item->ex_path;
815 	path_get(&item->ex_path);
816 	new->ex_fslocs.locations = NULL;
817 	new->ex_fslocs.locations_count = 0;
818 	new->ex_fslocs.migrated = 0;
819 	new->ex_layout_types = 0;
820 	new->ex_uuid = NULL;
821 	new->cd = item->cd;
822 	export_stats_reset(&new->ex_stats);
823 }
824 
export_update(struct cache_head * cnew,struct cache_head * citem)825 static void export_update(struct cache_head *cnew, struct cache_head *citem)
826 {
827 	struct svc_export *new = container_of(cnew, struct svc_export, h);
828 	struct svc_export *item = container_of(citem, struct svc_export, h);
829 	int i;
830 
831 	new->ex_flags = item->ex_flags;
832 	new->ex_anon_uid = item->ex_anon_uid;
833 	new->ex_anon_gid = item->ex_anon_gid;
834 	new->ex_fsid = item->ex_fsid;
835 	new->ex_devid_map = item->ex_devid_map;
836 	item->ex_devid_map = NULL;
837 	new->ex_uuid = item->ex_uuid;
838 	item->ex_uuid = NULL;
839 	new->ex_fslocs.locations = item->ex_fslocs.locations;
840 	item->ex_fslocs.locations = NULL;
841 	new->ex_fslocs.locations_count = item->ex_fslocs.locations_count;
842 	item->ex_fslocs.locations_count = 0;
843 	new->ex_fslocs.migrated = item->ex_fslocs.migrated;
844 	item->ex_fslocs.migrated = 0;
845 	new->ex_layout_types = item->ex_layout_types;
846 	new->ex_nflavors = item->ex_nflavors;
847 	for (i = 0; i < MAX_SECINFO_LIST; i++) {
848 		new->ex_flavors[i] = item->ex_flavors[i];
849 	}
850 	new->ex_xprtsec_modes = item->ex_xprtsec_modes;
851 }
852 
svc_export_alloc(void)853 static struct cache_head *svc_export_alloc(void)
854 {
855 	struct svc_export *i = kmalloc(sizeof(*i), GFP_KERNEL);
856 	if (!i)
857 		return NULL;
858 
859 	if (export_stats_init(&i->ex_stats)) {
860 		kfree(i);
861 		return NULL;
862 	}
863 
864 	return &i->h;
865 }
866 
867 static const struct cache_detail svc_export_cache_template = {
868 	.owner		= THIS_MODULE,
869 	.hash_size	= EXPORT_HASHMAX,
870 	.name		= "nfsd.export",
871 	.cache_put	= svc_export_put,
872 	.cache_upcall	= svc_export_upcall,
873 	.cache_request	= svc_export_request,
874 	.cache_parse	= svc_export_parse,
875 	.cache_show	= svc_export_show,
876 	.match		= svc_export_match,
877 	.init		= svc_export_init,
878 	.update		= export_update,
879 	.alloc		= svc_export_alloc,
880 };
881 
882 static int
svc_export_hash(struct svc_export * exp)883 svc_export_hash(struct svc_export *exp)
884 {
885 	int hash;
886 
887 	hash = hash_ptr(exp->ex_client, EXPORT_HASHBITS);
888 	hash ^= hash_ptr(exp->ex_path.dentry, EXPORT_HASHBITS);
889 	hash ^= hash_ptr(exp->ex_path.mnt, EXPORT_HASHBITS);
890 	return hash;
891 }
892 
893 static struct svc_export *
svc_export_lookup(struct svc_export * exp)894 svc_export_lookup(struct svc_export *exp)
895 {
896 	struct cache_head *ch;
897 	int hash = svc_export_hash(exp);
898 
899 	ch = sunrpc_cache_lookup_rcu(exp->cd, &exp->h, hash);
900 	if (ch)
901 		return container_of(ch, struct svc_export, h);
902 	else
903 		return NULL;
904 }
905 
906 static struct svc_export *
svc_export_update(struct svc_export * new,struct svc_export * old)907 svc_export_update(struct svc_export *new, struct svc_export *old)
908 {
909 	struct cache_head *ch;
910 	int hash = svc_export_hash(old);
911 
912 	ch = sunrpc_cache_update(old->cd, &new->h, &old->h, hash);
913 	if (ch)
914 		return container_of(ch, struct svc_export, h);
915 	else
916 		return NULL;
917 }
918 
919 
920 static struct svc_expkey *
exp_find_key(struct cache_detail * cd,struct auth_domain * clp,int fsid_type,u32 * fsidv,struct cache_req * reqp)921 exp_find_key(struct cache_detail *cd, struct auth_domain *clp, int fsid_type,
922 	     u32 *fsidv, struct cache_req *reqp)
923 {
924 	struct svc_expkey key, *ek;
925 	int err;
926 
927 	if (!clp)
928 		return ERR_PTR(-ENOENT);
929 
930 	key.ek_client = clp;
931 	key.ek_fsidtype = fsid_type;
932 	memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
933 
934 	ek = svc_expkey_lookup(cd, &key);
935 	if (ek == NULL)
936 		return ERR_PTR(-ENOMEM);
937 	err = cache_check(cd, &ek->h, reqp);
938 	if (err) {
939 		trace_nfsd_exp_find_key(&key, err);
940 		return ERR_PTR(err);
941 	}
942 	return ek;
943 }
944 
945 static struct svc_export *
exp_get_by_name(struct cache_detail * cd,struct auth_domain * clp,const struct path * path,struct cache_req * reqp)946 exp_get_by_name(struct cache_detail *cd, struct auth_domain *clp,
947 		const struct path *path, struct cache_req *reqp)
948 {
949 	struct svc_export *exp, key;
950 	int err;
951 
952 	if (!clp)
953 		return ERR_PTR(-ENOENT);
954 
955 	key.ex_client = clp;
956 	key.ex_path = *path;
957 	key.cd = cd;
958 
959 	exp = svc_export_lookup(&key);
960 	if (exp == NULL)
961 		return ERR_PTR(-ENOMEM);
962 	err = cache_check(cd, &exp->h, reqp);
963 	if (err) {
964 		trace_nfsd_exp_get_by_name(&key, err);
965 		return ERR_PTR(err);
966 	}
967 	return exp;
968 }
969 
970 /*
971  * Find the export entry for a given dentry.
972  */
973 static struct svc_export *
exp_parent(struct cache_detail * cd,struct auth_domain * clp,struct path * path)974 exp_parent(struct cache_detail *cd, struct auth_domain *clp, struct path *path)
975 {
976 	struct dentry *saved = dget(path->dentry);
977 	struct svc_export *exp = exp_get_by_name(cd, clp, path, NULL);
978 
979 	while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
980 		struct dentry *parent = dget_parent(path->dentry);
981 		dput(path->dentry);
982 		path->dentry = parent;
983 		exp = exp_get_by_name(cd, clp, path, NULL);
984 	}
985 	dput(path->dentry);
986 	path->dentry = saved;
987 	return exp;
988 }
989 
990 
991 
992 /*
993  * Obtain the root fh on behalf of a client.
994  * This could be done in user space, but I feel that it adds some safety
995  * since its harder to fool a kernel module than a user space program.
996  */
997 int
exp_rootfh(struct net * net,struct auth_domain * clp,char * name,struct knfsd_fh * f,int maxsize)998 exp_rootfh(struct net *net, struct auth_domain *clp, char *name,
999 	   struct knfsd_fh *f, int maxsize)
1000 {
1001 	struct svc_export	*exp;
1002 	struct path		path;
1003 	struct inode		*inode;
1004 	struct svc_fh		fh;
1005 	int			err;
1006 	struct nfsd_net		*nn = net_generic(net, nfsd_net_id);
1007 	struct cache_detail	*cd = nn->svc_export_cache;
1008 
1009 	err = -EPERM;
1010 	/* NB: we probably ought to check that it's NUL-terminated */
1011 	if (kern_path(name, 0, &path)) {
1012 		printk("nfsd: exp_rootfh path not found %s", name);
1013 		return err;
1014 	}
1015 	inode = d_inode(path.dentry);
1016 
1017 	dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
1018 		 name, path.dentry, clp->name,
1019 		 inode->i_sb->s_id, inode->i_ino);
1020 	exp = exp_parent(cd, clp, &path);
1021 	if (IS_ERR(exp)) {
1022 		err = PTR_ERR(exp);
1023 		goto out;
1024 	}
1025 
1026 	/*
1027 	 * fh must be initialized before calling fh_compose
1028 	 */
1029 	fh_init(&fh, maxsize);
1030 	if (fh_compose(&fh, exp, path.dentry, NULL))
1031 		err = -EINVAL;
1032 	else
1033 		err = 0;
1034 	memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
1035 	fh_put(&fh);
1036 	exp_put(exp);
1037 out:
1038 	path_put(&path);
1039 	return err;
1040 }
1041 
exp_find(struct cache_detail * cd,struct auth_domain * clp,int fsid_type,u32 * fsidv,struct cache_req * reqp)1042 static struct svc_export *exp_find(struct cache_detail *cd,
1043 				   struct auth_domain *clp, int fsid_type,
1044 				   u32 *fsidv, struct cache_req *reqp)
1045 {
1046 	struct svc_export *exp;
1047 	struct nfsd_net *nn = net_generic(cd->net, nfsd_net_id);
1048 	struct svc_expkey *ek = exp_find_key(nn->svc_expkey_cache, clp, fsid_type, fsidv, reqp);
1049 	if (IS_ERR(ek))
1050 		return ERR_CAST(ek);
1051 
1052 	exp = exp_get_by_name(cd, clp, &ek->ek_path, reqp);
1053 	cache_put(&ek->h, nn->svc_expkey_cache);
1054 
1055 	if (IS_ERR(exp))
1056 		return ERR_CAST(exp);
1057 	return exp;
1058 }
1059 
check_nfsd_access(struct svc_export * exp,struct svc_rqst * rqstp)1060 __be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp)
1061 {
1062 	struct exp_flavor_info *f, *end = exp->ex_flavors + exp->ex_nflavors;
1063 	struct svc_xprt *xprt = rqstp->rq_xprt;
1064 
1065 	if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_NONE) {
1066 		if (!test_bit(XPT_TLS_SESSION, &xprt->xpt_flags))
1067 			goto ok;
1068 	}
1069 	if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_TLS) {
1070 		if (test_bit(XPT_TLS_SESSION, &xprt->xpt_flags) &&
1071 		    !test_bit(XPT_PEER_AUTH, &xprt->xpt_flags))
1072 			goto ok;
1073 	}
1074 	if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_MTLS) {
1075 		if (test_bit(XPT_TLS_SESSION, &xprt->xpt_flags) &&
1076 		    test_bit(XPT_PEER_AUTH, &xprt->xpt_flags))
1077 			goto ok;
1078 	}
1079 	goto denied;
1080 
1081 ok:
1082 	/* legacy gss-only clients are always OK: */
1083 	if (exp->ex_client == rqstp->rq_gssclient)
1084 		return 0;
1085 	/* ip-address based client; check sec= export option: */
1086 	for (f = exp->ex_flavors; f < end; f++) {
1087 		if (f->pseudoflavor == rqstp->rq_cred.cr_flavor)
1088 			return 0;
1089 	}
1090 	/* defaults in absence of sec= options: */
1091 	if (exp->ex_nflavors == 0) {
1092 		if (rqstp->rq_cred.cr_flavor == RPC_AUTH_NULL ||
1093 		    rqstp->rq_cred.cr_flavor == RPC_AUTH_UNIX)
1094 			return 0;
1095 	}
1096 
1097 	/* If the compound op contains a spo_must_allowed op,
1098 	 * it will be sent with integrity/protection which
1099 	 * will have to be expressly allowed on mounts that
1100 	 * don't support it
1101 	 */
1102 
1103 	if (nfsd4_spo_must_allow(rqstp))
1104 		return 0;
1105 
1106 denied:
1107 	return rqstp->rq_vers < 4 ? nfserr_acces : nfserr_wrongsec;
1108 }
1109 
1110 /*
1111  * Uses rq_client and rq_gssclient to find an export; uses rq_client (an
1112  * auth_unix client) if it's available and has secinfo information;
1113  * otherwise, will try to use rq_gssclient.
1114  *
1115  * Called from functions that handle requests; functions that do work on
1116  * behalf of mountd are passed a single client name to use, and should
1117  * use exp_get_by_name() or exp_find().
1118  */
1119 struct svc_export *
rqst_exp_get_by_name(struct svc_rqst * rqstp,struct path * path)1120 rqst_exp_get_by_name(struct svc_rqst *rqstp, struct path *path)
1121 {
1122 	struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
1123 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1124 	struct cache_detail *cd = nn->svc_export_cache;
1125 
1126 	if (rqstp->rq_client == NULL)
1127 		goto gss;
1128 
1129 	/* First try the auth_unix client: */
1130 	exp = exp_get_by_name(cd, rqstp->rq_client, path, &rqstp->rq_chandle);
1131 	if (PTR_ERR(exp) == -ENOENT)
1132 		goto gss;
1133 	if (IS_ERR(exp))
1134 		return exp;
1135 	/* If it has secinfo, assume there are no gss/... clients */
1136 	if (exp->ex_nflavors > 0)
1137 		return exp;
1138 gss:
1139 	/* Otherwise, try falling back on gss client */
1140 	if (rqstp->rq_gssclient == NULL)
1141 		return exp;
1142 	gssexp = exp_get_by_name(cd, rqstp->rq_gssclient, path, &rqstp->rq_chandle);
1143 	if (PTR_ERR(gssexp) == -ENOENT)
1144 		return exp;
1145 	if (!IS_ERR(exp))
1146 		exp_put(exp);
1147 	return gssexp;
1148 }
1149 
1150 struct svc_export *
rqst_exp_find(struct svc_rqst * rqstp,int fsid_type,u32 * fsidv)1151 rqst_exp_find(struct svc_rqst *rqstp, int fsid_type, u32 *fsidv)
1152 {
1153 	struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
1154 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1155 	struct cache_detail *cd = nn->svc_export_cache;
1156 
1157 	if (rqstp->rq_client == NULL)
1158 		goto gss;
1159 
1160 	/* First try the auth_unix client: */
1161 	exp = exp_find(cd, rqstp->rq_client, fsid_type,
1162 		       fsidv, &rqstp->rq_chandle);
1163 	if (PTR_ERR(exp) == -ENOENT)
1164 		goto gss;
1165 	if (IS_ERR(exp))
1166 		return exp;
1167 	/* If it has secinfo, assume there are no gss/... clients */
1168 	if (exp->ex_nflavors > 0)
1169 		return exp;
1170 gss:
1171 	/* Otherwise, try falling back on gss client */
1172 	if (rqstp->rq_gssclient == NULL)
1173 		return exp;
1174 	gssexp = exp_find(cd, rqstp->rq_gssclient, fsid_type, fsidv,
1175 						&rqstp->rq_chandle);
1176 	if (PTR_ERR(gssexp) == -ENOENT)
1177 		return exp;
1178 	if (!IS_ERR(exp))
1179 		exp_put(exp);
1180 	return gssexp;
1181 }
1182 
1183 struct svc_export *
rqst_exp_parent(struct svc_rqst * rqstp,struct path * path)1184 rqst_exp_parent(struct svc_rqst *rqstp, struct path *path)
1185 {
1186 	struct dentry *saved = dget(path->dentry);
1187 	struct svc_export *exp = rqst_exp_get_by_name(rqstp, path);
1188 
1189 	while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
1190 		struct dentry *parent = dget_parent(path->dentry);
1191 		dput(path->dentry);
1192 		path->dentry = parent;
1193 		exp = rqst_exp_get_by_name(rqstp, path);
1194 	}
1195 	dput(path->dentry);
1196 	path->dentry = saved;
1197 	return exp;
1198 }
1199 
rqst_find_fsidzero_export(struct svc_rqst * rqstp)1200 struct svc_export *rqst_find_fsidzero_export(struct svc_rqst *rqstp)
1201 {
1202 	u32 fsidv[2];
1203 
1204 	mk_fsid(FSID_NUM, fsidv, 0, 0, 0, NULL);
1205 
1206 	return rqst_exp_find(rqstp, FSID_NUM, fsidv);
1207 }
1208 
1209 /*
1210  * Called when we need the filehandle for the root of the pseudofs,
1211  * for a given NFSv4 client.   The root is defined to be the
1212  * export point with fsid==0
1213  */
1214 __be32
exp_pseudoroot(struct svc_rqst * rqstp,struct svc_fh * fhp)1215 exp_pseudoroot(struct svc_rqst *rqstp, struct svc_fh *fhp)
1216 {
1217 	struct svc_export *exp;
1218 	__be32 rv;
1219 
1220 	exp = rqst_find_fsidzero_export(rqstp);
1221 	if (IS_ERR(exp))
1222 		return nfserrno(PTR_ERR(exp));
1223 	rv = fh_compose(fhp, exp, exp->ex_path.dentry, NULL);
1224 	exp_put(exp);
1225 	return rv;
1226 }
1227 
1228 static struct flags {
1229 	int flag;
1230 	char *name[2];
1231 } expflags[] = {
1232 	{ NFSEXP_READONLY, {"ro", "rw"}},
1233 	{ NFSEXP_INSECURE_PORT, {"insecure", ""}},
1234 	{ NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
1235 	{ NFSEXP_ALLSQUASH, {"all_squash", ""}},
1236 	{ NFSEXP_ASYNC, {"async", "sync"}},
1237 	{ NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
1238 	{ NFSEXP_NOREADDIRPLUS, {"nordirplus", ""}},
1239 	{ NFSEXP_NOHIDE, {"nohide", ""}},
1240 	{ NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
1241 	{ NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
1242 	{ NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
1243 	{ NFSEXP_V4ROOT, {"v4root", ""}},
1244 	{ NFSEXP_PNFS, {"pnfs", ""}},
1245 	{ NFSEXP_SECURITY_LABEL, {"security_label", ""}},
1246 	{ 0, {"", ""}}
1247 };
1248 
show_expflags(struct seq_file * m,int flags,int mask)1249 static void show_expflags(struct seq_file *m, int flags, int mask)
1250 {
1251 	struct flags *flg;
1252 	int state, first = 0;
1253 
1254 	for (flg = expflags; flg->flag; flg++) {
1255 		if (flg->flag & ~mask)
1256 			continue;
1257 		state = (flg->flag & flags) ? 0 : 1;
1258 		if (*flg->name[state])
1259 			seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
1260 	}
1261 }
1262 
show_secinfo_flags(struct seq_file * m,int flags)1263 static void show_secinfo_flags(struct seq_file *m, int flags)
1264 {
1265 	seq_printf(m, ",");
1266 	show_expflags(m, flags, NFSEXP_SECINFO_FLAGS);
1267 }
1268 
secinfo_flags_equal(int f,int g)1269 static bool secinfo_flags_equal(int f, int g)
1270 {
1271 	f &= NFSEXP_SECINFO_FLAGS;
1272 	g &= NFSEXP_SECINFO_FLAGS;
1273 	return f == g;
1274 }
1275 
show_secinfo_run(struct seq_file * m,struct exp_flavor_info ** fp,struct exp_flavor_info * end)1276 static int show_secinfo_run(struct seq_file *m, struct exp_flavor_info **fp, struct exp_flavor_info *end)
1277 {
1278 	int flags;
1279 
1280 	flags = (*fp)->flags;
1281 	seq_printf(m, ",sec=%d", (*fp)->pseudoflavor);
1282 	(*fp)++;
1283 	while (*fp != end && secinfo_flags_equal(flags, (*fp)->flags)) {
1284 		seq_printf(m, ":%d", (*fp)->pseudoflavor);
1285 		(*fp)++;
1286 	}
1287 	return flags;
1288 }
1289 
show_secinfo(struct seq_file * m,struct svc_export * exp)1290 static void show_secinfo(struct seq_file *m, struct svc_export *exp)
1291 {
1292 	struct exp_flavor_info *f;
1293 	struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
1294 	int flags;
1295 
1296 	if (exp->ex_nflavors == 0)
1297 		return;
1298 	f = exp->ex_flavors;
1299 	flags = show_secinfo_run(m, &f, end);
1300 	if (!secinfo_flags_equal(flags, exp->ex_flags))
1301 		show_secinfo_flags(m, flags);
1302 	while (f != end) {
1303 		flags = show_secinfo_run(m, &f, end);
1304 		show_secinfo_flags(m, flags);
1305 	}
1306 }
1307 
exp_flags(struct seq_file * m,int flag,int fsid,kuid_t anonu,kgid_t anong,struct nfsd4_fs_locations * fsloc)1308 static void exp_flags(struct seq_file *m, int flag, int fsid,
1309 		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fsloc)
1310 {
1311 	struct user_namespace *userns = m->file->f_cred->user_ns;
1312 
1313 	show_expflags(m, flag, NFSEXP_ALLFLAGS);
1314 	if (flag & NFSEXP_FSID)
1315 		seq_printf(m, ",fsid=%d", fsid);
1316 	if (!uid_eq(anonu, make_kuid(userns, (uid_t)-2)) &&
1317 	    !uid_eq(anonu, make_kuid(userns, 0x10000-2)))
1318 		seq_printf(m, ",anonuid=%u", from_kuid_munged(userns, anonu));
1319 	if (!gid_eq(anong, make_kgid(userns, (gid_t)-2)) &&
1320 	    !gid_eq(anong, make_kgid(userns, 0x10000-2)))
1321 		seq_printf(m, ",anongid=%u", from_kgid_munged(userns, anong));
1322 	if (fsloc && fsloc->locations_count > 0) {
1323 		char *loctype = (fsloc->migrated) ? "refer" : "replicas";
1324 		int i;
1325 
1326 		seq_printf(m, ",%s=", loctype);
1327 		seq_escape(m, fsloc->locations[0].path, ",;@ \t\n\\");
1328 		seq_putc(m, '@');
1329 		seq_escape(m, fsloc->locations[0].hosts, ",;@ \t\n\\");
1330 		for (i = 1; i < fsloc->locations_count; i++) {
1331 			seq_putc(m, ';');
1332 			seq_escape(m, fsloc->locations[i].path, ",;@ \t\n\\");
1333 			seq_putc(m, '@');
1334 			seq_escape(m, fsloc->locations[i].hosts, ",;@ \t\n\\");
1335 		}
1336 	}
1337 }
1338 
e_show(struct seq_file * m,void * p)1339 static int e_show(struct seq_file *m, void *p)
1340 {
1341 	struct cache_head *cp = p;
1342 	struct svc_export *exp = container_of(cp, struct svc_export, h);
1343 	struct cache_detail *cd = m->private;
1344 	bool export_stats = is_export_stats_file(m);
1345 
1346 	if (p == SEQ_START_TOKEN) {
1347 		seq_puts(m, "# Version 1.1\n");
1348 		if (export_stats)
1349 			seq_puts(m, "# Path Client Start-time\n#\tStats\n");
1350 		else
1351 			seq_puts(m, "# Path Client(Flags) # IPs\n");
1352 		return 0;
1353 	}
1354 
1355 	exp_get(exp);
1356 	if (cache_check(cd, &exp->h, NULL))
1357 		return 0;
1358 	exp_put(exp);
1359 	return svc_export_show(m, cd, cp);
1360 }
1361 
1362 const struct seq_operations nfs_exports_op = {
1363 	.start	= cache_seq_start_rcu,
1364 	.next	= cache_seq_next_rcu,
1365 	.stop	= cache_seq_stop_rcu,
1366 	.show	= e_show,
1367 };
1368 
1369 /*
1370  * Initialize the exports module.
1371  */
1372 int
nfsd_export_init(struct net * net)1373 nfsd_export_init(struct net *net)
1374 {
1375 	int rv;
1376 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1377 
1378 	dprintk("nfsd: initializing export module (net: %x).\n", net->ns.inum);
1379 
1380 	nn->svc_export_cache = cache_create_net(&svc_export_cache_template, net);
1381 	if (IS_ERR(nn->svc_export_cache))
1382 		return PTR_ERR(nn->svc_export_cache);
1383 	rv = cache_register_net(nn->svc_export_cache, net);
1384 	if (rv)
1385 		goto destroy_export_cache;
1386 
1387 	nn->svc_expkey_cache = cache_create_net(&svc_expkey_cache_template, net);
1388 	if (IS_ERR(nn->svc_expkey_cache)) {
1389 		rv = PTR_ERR(nn->svc_expkey_cache);
1390 		goto unregister_export_cache;
1391 	}
1392 	rv = cache_register_net(nn->svc_expkey_cache, net);
1393 	if (rv)
1394 		goto destroy_expkey_cache;
1395 	return 0;
1396 
1397 destroy_expkey_cache:
1398 	cache_destroy_net(nn->svc_expkey_cache, net);
1399 unregister_export_cache:
1400 	cache_unregister_net(nn->svc_export_cache, net);
1401 destroy_export_cache:
1402 	cache_destroy_net(nn->svc_export_cache, net);
1403 	return rv;
1404 }
1405 
1406 /*
1407  * Flush exports table - called when last nfsd thread is killed
1408  */
1409 void
nfsd_export_flush(struct net * net)1410 nfsd_export_flush(struct net *net)
1411 {
1412 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1413 
1414 	cache_purge(nn->svc_expkey_cache);
1415 	cache_purge(nn->svc_export_cache);
1416 }
1417 
1418 /*
1419  * Shutdown the exports module.
1420  */
1421 void
nfsd_export_shutdown(struct net * net)1422 nfsd_export_shutdown(struct net *net)
1423 {
1424 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1425 
1426 	dprintk("nfsd: shutting down export module (net: %x).\n", net->ns.inum);
1427 
1428 	cache_unregister_net(nn->svc_expkey_cache, net);
1429 	cache_unregister_net(nn->svc_export_cache, net);
1430 	cache_destroy_net(nn->svc_expkey_cache, net);
1431 	cache_destroy_net(nn->svc_export_cache, net);
1432 	svcauth_unix_purge(net);
1433 
1434 	dprintk("nfsd: export shutdown complete (net: %x).\n", net->ns.inum);
1435 }
1436