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