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   1/*
   2 * NFS exporting and validation.
   3 *
   4 * We maintain a list of clients, each of which has a list of
   5 * exports. To export an fs to a given client, you first have
   6 * to create the client entry with NFSCTL_ADDCLIENT, which
   7 * creates a client control block and adds it to the hash
   8 * table. Then, you call NFSCTL_EXPORT for each fs.
   9 *
  10 *
  11 * Copyright (C) 1995, 1996 Olaf Kirch, <okir@monad.swb.de>
  12 */
  13
  14#include <linux/slab.h>
  15#include <linux/namei.h>
  16#include <linux/module.h>
  17#include <linux/exportfs.h>
  18#include <linux/sunrpc/svc_xprt.h>
  19
  20#include <net/ipv6.h>
  21
  22#include "nfsd.h"
  23#include "nfsfh.h"
  24#include "netns.h"
  25
  26#define NFSDDBG_FACILITY	NFSDDBG_EXPORT
  27
  28typedef struct auth_domain	svc_client;
  29typedef struct svc_export	svc_export;
  30
  31/*
  32 * We have two caches.
  33 * One maps client+vfsmnt+dentry to export options - the export map
  34 * The other maps client+filehandle-fragment to export options. - the expkey map
  35 *
  36 * The export options are actually stored in the first map, and the
  37 * second map contains a reference to the entry in the first map.
  38 */
  39
  40#define	EXPKEY_HASHBITS		8
  41#define	EXPKEY_HASHMAX		(1 << EXPKEY_HASHBITS)
  42#define	EXPKEY_HASHMASK		(EXPKEY_HASHMAX -1)
  43
  44static void expkey_put(struct kref *ref)
  45{
  46	struct svc_expkey *key = container_of(ref, struct svc_expkey, h.ref);
  47
  48	if (test_bit(CACHE_VALID, &key->h.flags) &&
  49	    !test_bit(CACHE_NEGATIVE, &key->h.flags))
  50		path_put(&key->ek_path);
  51	auth_domain_put(key->ek_client);
  52	kfree(key);
  53}
  54
  55static void expkey_request(struct cache_detail *cd,
  56			   struct cache_head *h,
  57			   char **bpp, int *blen)
  58{
  59	/* client fsidtype \xfsid */
  60	struct svc_expkey *ek = container_of(h, struct svc_expkey, h);
  61	char type[5];
  62
  63	qword_add(bpp, blen, ek->ek_client->name);
  64	snprintf(type, 5, "%d", ek->ek_fsidtype);
  65	qword_add(bpp, blen, type);
  66	qword_addhex(bpp, blen, (char*)ek->ek_fsid, key_len(ek->ek_fsidtype));
  67	(*bpp)[-1] = '\n';
  68}
  69
  70static struct svc_expkey *svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
  71					    struct svc_expkey *old);
  72static struct svc_expkey *svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *);
  73
  74static int expkey_parse(struct cache_detail *cd, char *mesg, int mlen)
  75{
  76	/* client fsidtype fsid [path] */
  77	char *buf;
  78	int len;
  79	struct auth_domain *dom = NULL;
  80	int err;
  81	int fsidtype;
  82	char *ep;
  83	struct svc_expkey key;
  84	struct svc_expkey *ek = NULL;
  85
  86	if (mesg[mlen - 1] != '\n')
  87		return -EINVAL;
  88	mesg[mlen-1] = 0;
  89
  90	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
  91	err = -ENOMEM;
  92	if (!buf)
  93		goto out;
  94
  95	err = -EINVAL;
  96	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
  97		goto out;
  98
  99	err = -ENOENT;
 100	dom = auth_domain_find(buf);
 101	if (!dom)
 102		goto out;
 103	dprintk("found domain %s\n", buf);
 104
 105	err = -EINVAL;
 106	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 107		goto out;
 108	fsidtype = simple_strtoul(buf, &ep, 10);
 109	if (*ep)
 110		goto out;
 111	dprintk("found fsidtype %d\n", fsidtype);
 112	if (key_len(fsidtype)==0) /* invalid type */
 113		goto out;
 114	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 115		goto out;
 116	dprintk("found fsid length %d\n", len);
 117	if (len != key_len(fsidtype))
 118		goto out;
 119
 120	/* OK, we seem to have a valid key */
 121	key.h.flags = 0;
 122	key.h.expiry_time = get_expiry(&mesg);
 123	if (key.h.expiry_time == 0)
 124		goto out;
 125
 126	key.ek_client = dom;	
 127	key.ek_fsidtype = fsidtype;
 128	memcpy(key.ek_fsid, buf, len);
 129
 130	ek = svc_expkey_lookup(cd, &key);
 131	err = -ENOMEM;
 132	if (!ek)
 133		goto out;
 134
 135	/* now we want a pathname, or empty meaning NEGATIVE  */
 136	err = -EINVAL;
 137	len = qword_get(&mesg, buf, PAGE_SIZE);
 138	if (len < 0)
 139		goto out;
 140	dprintk("Path seems to be <%s>\n", buf);
 141	err = 0;
 142	if (len == 0) {
 143		set_bit(CACHE_NEGATIVE, &key.h.flags);
 144		ek = svc_expkey_update(cd, &key, ek);
 145		if (!ek)
 146			err = -ENOMEM;
 147	} else {
 148		err = kern_path(buf, 0, &key.ek_path);
 149		if (err)
 150			goto out;
 151
 152		dprintk("Found the path %s\n", buf);
 153
 154		ek = svc_expkey_update(cd, &key, ek);
 155		if (!ek)
 156			err = -ENOMEM;
 157		path_put(&key.ek_path);
 158	}
 159	cache_flush();
 160 out:
 161	if (ek)
 162		cache_put(&ek->h, cd);
 163	if (dom)
 164		auth_domain_put(dom);
 165	kfree(buf);
 166	return err;
 167}
 168
 169static int expkey_show(struct seq_file *m,
 170		       struct cache_detail *cd,
 171		       struct cache_head *h)
 172{
 173	struct svc_expkey *ek ;
 174	int i;
 175
 176	if (h ==NULL) {
 177		seq_puts(m, "#domain fsidtype fsid [path]\n");
 178		return 0;
 179	}
 180	ek = container_of(h, struct svc_expkey, h);
 181	seq_printf(m, "%s %d 0x", ek->ek_client->name,
 182		   ek->ek_fsidtype);
 183	for (i=0; i < key_len(ek->ek_fsidtype)/4; i++)
 184		seq_printf(m, "%08x", ek->ek_fsid[i]);
 185	if (test_bit(CACHE_VALID, &h->flags) && 
 186	    !test_bit(CACHE_NEGATIVE, &h->flags)) {
 187		seq_printf(m, " ");
 188		seq_path(m, &ek->ek_path, "\\ \t\n");
 189	}
 190	seq_printf(m, "\n");
 191	return 0;
 192}
 193
 194static inline int expkey_match (struct cache_head *a, struct cache_head *b)
 195{
 196	struct svc_expkey *orig = container_of(a, struct svc_expkey, h);
 197	struct svc_expkey *new = container_of(b, struct svc_expkey, h);
 198
 199	if (orig->ek_fsidtype != new->ek_fsidtype ||
 200	    orig->ek_client != new->ek_client ||
 201	    memcmp(orig->ek_fsid, new->ek_fsid, key_len(orig->ek_fsidtype)) != 0)
 202		return 0;
 203	return 1;
 204}
 205
 206static inline void expkey_init(struct cache_head *cnew,
 207				   struct cache_head *citem)
 208{
 209	struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
 210	struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
 211
 212	kref_get(&item->ek_client->ref);
 213	new->ek_client = item->ek_client;
 214	new->ek_fsidtype = item->ek_fsidtype;
 215
 216	memcpy(new->ek_fsid, item->ek_fsid, sizeof(new->ek_fsid));
 217}
 218
 219static inline void expkey_update(struct cache_head *cnew,
 220				   struct cache_head *citem)
 221{
 222	struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
 223	struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
 224
 225	new->ek_path = item->ek_path;
 226	path_get(&item->ek_path);
 227}
 228
 229static struct cache_head *expkey_alloc(void)
 230{
 231	struct svc_expkey *i = kmalloc(sizeof(*i), GFP_KERNEL);
 232	if (i)
 233		return &i->h;
 234	else
 235		return NULL;
 236}
 237
 238static struct cache_detail svc_expkey_cache_template = {
 239	.owner		= THIS_MODULE,
 240	.hash_size	= EXPKEY_HASHMAX,
 241	.name		= "nfsd.fh",
 242	.cache_put	= expkey_put,
 243	.cache_request	= expkey_request,
 244	.cache_parse	= expkey_parse,
 245	.cache_show	= expkey_show,
 246	.match		= expkey_match,
 247	.init		= expkey_init,
 248	.update       	= expkey_update,
 249	.alloc		= expkey_alloc,
 250};
 251
 252static int
 253svc_expkey_hash(struct svc_expkey *item)
 254{
 255	int hash = item->ek_fsidtype;
 256	char * cp = (char*)item->ek_fsid;
 257	int len = key_len(item->ek_fsidtype);
 258
 259	hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
 260	hash ^= hash_ptr(item->ek_client, EXPKEY_HASHBITS);
 261	hash &= EXPKEY_HASHMASK;
 262	return hash;
 263}
 264
 265static struct svc_expkey *
 266svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *item)
 267{
 268	struct cache_head *ch;
 269	int hash = svc_expkey_hash(item);
 270
 271	ch = sunrpc_cache_lookup(cd, &item->h, hash);
 272	if (ch)
 273		return container_of(ch, struct svc_expkey, h);
 274	else
 275		return NULL;
 276}
 277
 278static struct svc_expkey *
 279svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
 280		  struct svc_expkey *old)
 281{
 282	struct cache_head *ch;
 283	int hash = svc_expkey_hash(new);
 284
 285	ch = sunrpc_cache_update(cd, &new->h, &old->h, hash);
 286	if (ch)
 287		return container_of(ch, struct svc_expkey, h);
 288	else
 289		return NULL;
 290}
 291
 292
 293#define	EXPORT_HASHBITS		8
 294#define	EXPORT_HASHMAX		(1<< EXPORT_HASHBITS)
 295
 296static void nfsd4_fslocs_free(struct nfsd4_fs_locations *fsloc)
 297{
 298	int i;
 299
 300	for (i = 0; i < fsloc->locations_count; i++) {
 301		kfree(fsloc->locations[i].path);
 302		kfree(fsloc->locations[i].hosts);
 303	}
 304	kfree(fsloc->locations);
 305}
 306
 307static void svc_export_put(struct kref *ref)
 308{
 309	struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
 310	path_put(&exp->ex_path);
 311	auth_domain_put(exp->ex_client);
 312	nfsd4_fslocs_free(&exp->ex_fslocs);
 313	kfree(exp->ex_uuid);
 314	kfree(exp);
 315}
 316
 317static void svc_export_request(struct cache_detail *cd,
 318			       struct cache_head *h,
 319			       char **bpp, int *blen)
 320{
 321	/*  client path */
 322	struct svc_export *exp = container_of(h, struct svc_export, h);
 323	char *pth;
 324
 325	qword_add(bpp, blen, exp->ex_client->name);
 326	pth = d_path(&exp->ex_path, *bpp, *blen);
 327	if (IS_ERR(pth)) {
 328		/* is this correct? */
 329		(*bpp)[0] = '\n';
 330		return;
 331	}
 332	qword_add(bpp, blen, pth);
 333	(*bpp)[-1] = '\n';
 334}
 335
 336static struct svc_export *svc_export_update(struct svc_export *new,
 337					    struct svc_export *old);
 338static struct svc_export *svc_export_lookup(struct svc_export *);
 339
 340static int check_export(struct inode *inode, int *flags, unsigned char *uuid)
 341{
 342
 343	/*
 344	 * We currently export only dirs, regular files, and (for v4
 345	 * pseudoroot) symlinks.
 346	 */
 347	if (!S_ISDIR(inode->i_mode) &&
 348	    !S_ISLNK(inode->i_mode) &&
 349	    !S_ISREG(inode->i_mode))
 350		return -ENOTDIR;
 351
 352	/*
 353	 * Mountd should never pass down a writeable V4ROOT export, but,
 354	 * just to make sure:
 355	 */
 356	if (*flags & NFSEXP_V4ROOT)
 357		*flags |= NFSEXP_READONLY;
 358
 359	/* There are two requirements on a filesystem to be exportable.
 360	 * 1:  We must be able to identify the filesystem from a number.
 361	 *       either a device number (so FS_REQUIRES_DEV needed)
 362	 *       or an FSID number (so NFSEXP_FSID or ->uuid is needed).
 363	 * 2:  We must be able to find an inode from a filehandle.
 364	 *       This means that s_export_op must be set.
 365	 */
 366	if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) &&
 367	    !(*flags & NFSEXP_FSID) &&
 368	    uuid == NULL) {
 369		dprintk("exp_export: export of non-dev fs without fsid\n");
 370		return -EINVAL;
 371	}
 372
 373	if (!inode->i_sb->s_export_op ||
 374	    !inode->i_sb->s_export_op->fh_to_dentry) {
 375		dprintk("exp_export: export of invalid fs type.\n");
 376		return -EINVAL;
 377	}
 378
 379	return 0;
 380
 381}
 382
 383#ifdef CONFIG_NFSD_V4
 384
 385static int
 386fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc)
 387{
 388	int len;
 389	int migrated, i, err;
 390
 391	/* listsize */
 392	err = get_uint(mesg, &fsloc->locations_count);
 393	if (err)
 394		return err;
 395	if (fsloc->locations_count > MAX_FS_LOCATIONS)
 396		return -EINVAL;
 397	if (fsloc->locations_count == 0)
 398		return 0;
 399
 400	fsloc->locations = kzalloc(fsloc->locations_count
 401			* sizeof(struct nfsd4_fs_location), GFP_KERNEL);
 402	if (!fsloc->locations)
 403		return -ENOMEM;
 404	for (i=0; i < fsloc->locations_count; i++) {
 405		/* colon separated host list */
 406		err = -EINVAL;
 407		len = qword_get(mesg, buf, PAGE_SIZE);
 408		if (len <= 0)
 409			goto out_free_all;
 410		err = -ENOMEM;
 411		fsloc->locations[i].hosts = kstrdup(buf, GFP_KERNEL);
 412		if (!fsloc->locations[i].hosts)
 413			goto out_free_all;
 414		err = -EINVAL;
 415		/* slash separated path component list */
 416		len = qword_get(mesg, buf, PAGE_SIZE);
 417		if (len <= 0)
 418			goto out_free_all;
 419		err = -ENOMEM;
 420		fsloc->locations[i].path = kstrdup(buf, GFP_KERNEL);
 421		if (!fsloc->locations[i].path)
 422			goto out_free_all;
 423	}
 424	/* migrated */
 425	err = get_int(mesg, &migrated);
 426	if (err)
 427		goto out_free_all;
 428	err = -EINVAL;
 429	if (migrated < 0 || migrated > 1)
 430		goto out_free_all;
 431	fsloc->migrated = migrated;
 432	return 0;
 433out_free_all:
 434	nfsd4_fslocs_free(fsloc);
 435	return err;
 436}
 437
 438static int secinfo_parse(char **mesg, char *buf, struct svc_export *exp)
 439{
 440	int listsize, err;
 441	struct exp_flavor_info *f;
 442
 443	err = get_int(mesg, &listsize);
 444	if (err)
 445		return err;
 446	if (listsize < 0 || listsize > MAX_SECINFO_LIST)
 447		return -EINVAL;
 448
 449	for (f = exp->ex_flavors; f < exp->ex_flavors + listsize; f++) {
 450		err = get_uint(mesg, &f->pseudoflavor);
 451		if (err)
 452			return err;
 453		/*
 454		 * XXX: It would be nice to also check whether this
 455		 * pseudoflavor is supported, so we can discover the
 456		 * problem at export time instead of when a client fails
 457		 * to authenticate.
 458		 */
 459		err = get_uint(mesg, &f->flags);
 460		if (err)
 461			return err;
 462		/* Only some flags are allowed to differ between flavors: */
 463		if (~NFSEXP_SECINFO_FLAGS & (f->flags ^ exp->ex_flags))
 464			return -EINVAL;
 465	}
 466	exp->ex_nflavors = listsize;
 467	return 0;
 468}
 469
 470#else /* CONFIG_NFSD_V4 */
 471static inline int
 472fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc){return 0;}
 473static inline int
 474secinfo_parse(char **mesg, char *buf, struct svc_export *exp) { return 0; }
 475#endif
 476
 477static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
 478{
 479	/* client path expiry [flags anonuid anongid fsid] */
 480	char *buf;
 481	int len;
 482	int err;
 483	struct auth_domain *dom = NULL;
 484	struct svc_export exp = {}, *expp;
 485	int an_int;
 486
 487	if (mesg[mlen-1] != '\n')
 488		return -EINVAL;
 489	mesg[mlen-1] = 0;
 490
 491	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 492	if (!buf)
 493		return -ENOMEM;
 494
 495	/* client */
 496	err = -EINVAL;
 497	len = qword_get(&mesg, buf, PAGE_SIZE);
 498	if (len <= 0)
 499		goto out;
 500
 501	err = -ENOENT;
 502	dom = auth_domain_find(buf);
 503	if (!dom)
 504		goto out;
 505
 506	/* path */
 507	err = -EINVAL;
 508	if ((len = qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 509		goto out1;
 510
 511	err = kern_path(buf, 0, &exp.ex_path);
 512	if (err)
 513		goto out1;
 514
 515	exp.ex_client = dom;
 516	exp.cd = cd;
 517
 518	/* expiry */
 519	err = -EINVAL;
 520	exp.h.expiry_time = get_expiry(&mesg);
 521	if (exp.h.expiry_time == 0)
 522		goto out3;
 523
 524	/* flags */
 525	err = get_int(&mesg, &an_int);
 526	if (err == -ENOENT) {
 527		err = 0;
 528		set_bit(CACHE_NEGATIVE, &exp.h.flags);
 529	} else {
 530		if (err || an_int < 0)
 531			goto out3;
 532		exp.ex_flags= an_int;
 533	
 534		/* anon uid */
 535		err = get_int(&mesg, &an_int);
 536		if (err)
 537			goto out3;
 538		exp.ex_anon_uid= make_kuid(&init_user_ns, an_int);
 539
 540		/* anon gid */
 541		err = get_int(&mesg, &an_int);
 542		if (err)
 543			goto out3;
 544		exp.ex_anon_gid= make_kgid(&init_user_ns, an_int);
 545
 546		/* fsid */
 547		err = get_int(&mesg, &an_int);
 548		if (err)
 549			goto out3;
 550		exp.ex_fsid = an_int;
 551
 552		while ((len = qword_get(&mesg, buf, PAGE_SIZE)) > 0) {
 553			if (strcmp(buf, "fsloc") == 0)
 554				err = fsloc_parse(&mesg, buf, &exp.ex_fslocs);
 555			else if (strcmp(buf, "uuid") == 0) {
 556				/* expect a 16 byte uuid encoded as \xXXXX... */
 557				len = qword_get(&mesg, buf, PAGE_SIZE);
 558				if (len != 16)
 559					err  = -EINVAL;
 560				else {
 561					exp.ex_uuid =
 562						kmemdup(buf, 16, GFP_KERNEL);
 563					if (exp.ex_uuid == NULL)
 564						err = -ENOMEM;
 565				}
 566			} else if (strcmp(buf, "secinfo") == 0)
 567				err = secinfo_parse(&mesg, buf, &exp);
 568			else
 569				/* quietly ignore unknown words and anything
 570				 * following. Newer user-space can try to set
 571				 * new values, then see what the result was.
 572				 */
 573				break;
 574			if (err)
 575				goto out4;
 576		}
 577
 578		err = check_export(exp.ex_path.dentry->d_inode, &exp.ex_flags,
 579				   exp.ex_uuid);
 580		if (err)
 581			goto out4;
 582		/*
 583		 * No point caching this if it would immediately expire.
 584		 * Also, this protects exportfs's dummy export from the
 585		 * anon_uid/anon_gid checks:
 586		 */
 587		if (exp.h.expiry_time < seconds_since_boot())
 588			goto out4;
 589		/*
 590		 * For some reason exportfs has been passing down an
 591		 * invalid (-1) uid & gid on the "dummy" export which it
 592		 * uses to test export support.  To make sure exportfs
 593		 * sees errors from check_export we therefore need to
 594		 * delay these checks till after check_export:
 595		 */
 596		err = -EINVAL;
 597		if (!uid_valid(exp.ex_anon_uid))
 598			goto out4;
 599		if (!gid_valid(exp.ex_anon_gid))
 600			goto out4;
 601		err = 0;
 602	}
 603
 604	expp = svc_export_lookup(&exp);
 605	if (expp)
 606		expp = svc_export_update(&exp, expp);
 607	else
 608		err = -ENOMEM;
 609	cache_flush();
 610	if (expp == NULL)
 611		err = -ENOMEM;
 612	else
 613		exp_put(expp);
 614out4:
 615	nfsd4_fslocs_free(&exp.ex_fslocs);
 616	kfree(exp.ex_uuid);
 617out3:
 618	path_put(&exp.ex_path);
 619out1:
 620	auth_domain_put(dom);
 621out:
 622	kfree(buf);
 623	return err;
 624}
 625
 626static void exp_flags(struct seq_file *m, int flag, int fsid,
 627		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fslocs);
 628static void show_secinfo(struct seq_file *m, struct svc_export *exp);
 629
 630static int svc_export_show(struct seq_file *m,
 631			   struct cache_detail *cd,
 632			   struct cache_head *h)
 633{
 634	struct svc_export *exp ;
 635
 636	if (h ==NULL) {
 637		seq_puts(m, "#path domain(flags)\n");
 638		return 0;
 639	}
 640	exp = container_of(h, struct svc_export, h);
 641	seq_path(m, &exp->ex_path, " \t\n\\");
 642	seq_putc(m, '\t');
 643	seq_escape(m, exp->ex_client->name, " \t\n\\");
 644	seq_putc(m, '(');
 645	if (test_bit(CACHE_VALID, &h->flags) && 
 646	    !test_bit(CACHE_NEGATIVE, &h->flags)) {
 647		exp_flags(m, exp->ex_flags, exp->ex_fsid,
 648			  exp->ex_anon_uid, exp->ex_anon_gid, &exp->ex_fslocs);
 649		if (exp->ex_uuid) {
 650			int i;
 651			seq_puts(m, ",uuid=");
 652			for (i=0; i<16; i++) {
 653				if ((i&3) == 0 && i)
 654					seq_putc(m, ':');
 655				seq_printf(m, "%02x", exp->ex_uuid[i]);
 656			}
 657		}
 658		show_secinfo(m, exp);
 659	}
 660	seq_puts(m, ")\n");
 661	return 0;
 662}
 663static int svc_export_match(struct cache_head *a, struct cache_head *b)
 664{
 665	struct svc_export *orig = container_of(a, struct svc_export, h);
 666	struct svc_export *new = container_of(b, struct svc_export, h);
 667	return orig->ex_client == new->ex_client &&
 668		orig->ex_path.dentry == new->ex_path.dentry &&
 669		orig->ex_path.mnt == new->ex_path.mnt;
 670}
 671
 672static void svc_export_init(struct cache_head *cnew, struct cache_head *citem)
 673{
 674	struct svc_export *new = container_of(cnew, struct svc_export, h);
 675	struct svc_export *item = container_of(citem, struct svc_export, h);
 676
 677	kref_get(&item->ex_client->ref);
 678	new->ex_client = item->ex_client;
 679	new->ex_path.dentry = dget(item->ex_path.dentry);
 680	new->ex_path.mnt = mntget(item->ex_path.mnt);
 681	new->ex_fslocs.locations = NULL;
 682	new->ex_fslocs.locations_count = 0;
 683	new->ex_fslocs.migrated = 0;
 684	new->ex_uuid = NULL;
 685	new->cd = item->cd;
 686}
 687
 688static void export_update(struct cache_head *cnew, struct cache_head *citem)
 689{
 690	struct svc_export *new = container_of(cnew, struct svc_export, h);
 691	struct svc_export *item = container_of(citem, struct svc_export, h);
 692	int i;
 693
 694	new->ex_flags = item->ex_flags;
 695	new->ex_anon_uid = item->ex_anon_uid;
 696	new->ex_anon_gid = item->ex_anon_gid;
 697	new->ex_fsid = item->ex_fsid;
 698	new->ex_uuid = item->ex_uuid;
 699	item->ex_uuid = NULL;
 700	new->ex_fslocs.locations = item->ex_fslocs.locations;
 701	item->ex_fslocs.locations = NULL;
 702	new->ex_fslocs.locations_count = item->ex_fslocs.locations_count;
 703	item->ex_fslocs.locations_count = 0;
 704	new->ex_fslocs.migrated = item->ex_fslocs.migrated;
 705	item->ex_fslocs.migrated = 0;
 706	new->ex_nflavors = item->ex_nflavors;
 707	for (i = 0; i < MAX_SECINFO_LIST; i++) {
 708		new->ex_flavors[i] = item->ex_flavors[i];
 709	}
 710}
 711
 712static struct cache_head *svc_export_alloc(void)
 713{
 714	struct svc_export *i = kmalloc(sizeof(*i), GFP_KERNEL);
 715	if (i)
 716		return &i->h;
 717	else
 718		return NULL;
 719}
 720
 721static struct cache_detail svc_export_cache_template = {
 722	.owner		= THIS_MODULE,
 723	.hash_size	= EXPORT_HASHMAX,
 724	.name		= "nfsd.export",
 725	.cache_put	= svc_export_put,
 726	.cache_request	= svc_export_request,
 727	.cache_parse	= svc_export_parse,
 728	.cache_show	= svc_export_show,
 729	.match		= svc_export_match,
 730	.init		= svc_export_init,
 731	.update		= export_update,
 732	.alloc		= svc_export_alloc,
 733};
 734
 735static int
 736svc_export_hash(struct svc_export *exp)
 737{
 738	int hash;
 739
 740	hash = hash_ptr(exp->ex_client, EXPORT_HASHBITS);
 741	hash ^= hash_ptr(exp->ex_path.dentry, EXPORT_HASHBITS);
 742	hash ^= hash_ptr(exp->ex_path.mnt, EXPORT_HASHBITS);
 743	return hash;
 744}
 745
 746static struct svc_export *
 747svc_export_lookup(struct svc_export *exp)
 748{
 749	struct cache_head *ch;
 750	int hash = svc_export_hash(exp);
 751
 752	ch = sunrpc_cache_lookup(exp->cd, &exp->h, hash);
 753	if (ch)
 754		return container_of(ch, struct svc_export, h);
 755	else
 756		return NULL;
 757}
 758
 759static struct svc_export *
 760svc_export_update(struct svc_export *new, struct svc_export *old)
 761{
 762	struct cache_head *ch;
 763	int hash = svc_export_hash(old);
 764
 765	ch = sunrpc_cache_update(old->cd, &new->h, &old->h, hash);
 766	if (ch)
 767		return container_of(ch, struct svc_export, h);
 768	else
 769		return NULL;
 770}
 771
 772
 773static struct svc_expkey *
 774exp_find_key(struct cache_detail *cd, svc_client *clp, int fsid_type,
 775	     u32 *fsidv, struct cache_req *reqp)
 776{
 777	struct svc_expkey key, *ek;
 778	int err;
 779	
 780	if (!clp)
 781		return ERR_PTR(-ENOENT);
 782
 783	key.ek_client = clp;
 784	key.ek_fsidtype = fsid_type;
 785	memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
 786
 787	ek = svc_expkey_lookup(cd, &key);
 788	if (ek == NULL)
 789		return ERR_PTR(-ENOMEM);
 790	err = cache_check(cd, &ek->h, reqp);
 791	if (err)
 792		return ERR_PTR(err);
 793	return ek;
 794}
 795
 796
 797static svc_export *exp_get_by_name(struct cache_detail *cd, svc_client *clp,
 798				   const struct path *path, struct cache_req *reqp)
 799{
 800	struct svc_export *exp, key;
 801	int err;
 802
 803	if (!clp)
 804		return ERR_PTR(-ENOENT);
 805
 806	key.ex_client = clp;
 807	key.ex_path = *path;
 808	key.cd = cd;
 809
 810	exp = svc_export_lookup(&key);
 811	if (exp == NULL)
 812		return ERR_PTR(-ENOMEM);
 813	err = cache_check(cd, &exp->h, reqp);
 814	if (err)
 815		return ERR_PTR(err);
 816	return exp;
 817}
 818
 819/*
 820 * Find the export entry for a given dentry.
 821 */
 822static struct svc_export *exp_parent(struct cache_detail *cd, svc_client *clp,
 823				     struct path *path)
 824{
 825	struct dentry *saved = dget(path->dentry);
 826	svc_export *exp = exp_get_by_name(cd, clp, path, NULL);
 827
 828	while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
 829		struct dentry *parent = dget_parent(path->dentry);
 830		dput(path->dentry);
 831		path->dentry = parent;
 832		exp = exp_get_by_name(cd, clp, path, NULL);
 833	}
 834	dput(path->dentry);
 835	path->dentry = saved;
 836	return exp;
 837}
 838
 839
 840
 841/*
 842 * Obtain the root fh on behalf of a client.
 843 * This could be done in user space, but I feel that it adds some safety
 844 * since its harder to fool a kernel module than a user space program.
 845 */
 846int
 847exp_rootfh(struct net *net, svc_client *clp, char *name,
 848	   struct knfsd_fh *f, int maxsize)
 849{
 850	struct svc_export	*exp;
 851	struct path		path;
 852	struct inode		*inode;
 853	struct svc_fh		fh;
 854	int			err;
 855	struct nfsd_net		*nn = net_generic(net, nfsd_net_id);
 856	struct cache_detail	*cd = nn->svc_export_cache;
 857
 858	err = -EPERM;
 859	/* NB: we probably ought to check that it's NUL-terminated */
 860	if (kern_path(name, 0, &path)) {
 861		printk("nfsd: exp_rootfh path not found %s", name);
 862		return err;
 863	}
 864	inode = path.dentry->d_inode;
 865
 866	dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
 867		 name, path.dentry, clp->name,
 868		 inode->i_sb->s_id, inode->i_ino);
 869	exp = exp_parent(cd, clp, &path);
 870	if (IS_ERR(exp)) {
 871		err = PTR_ERR(exp);
 872		goto out;
 873	}
 874
 875	/*
 876	 * fh must be initialized before calling fh_compose
 877	 */
 878	fh_init(&fh, maxsize);
 879	if (fh_compose(&fh, exp, path.dentry, NULL))
 880		err = -EINVAL;
 881	else
 882		err = 0;
 883	memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
 884	fh_put(&fh);
 885	exp_put(exp);
 886out:
 887	path_put(&path);
 888	return err;
 889}
 890
 891static struct svc_export *exp_find(struct cache_detail *cd,
 892				   struct auth_domain *clp, int fsid_type,
 893				   u32 *fsidv, struct cache_req *reqp)
 894{
 895	struct svc_export *exp;
 896	struct nfsd_net *nn = net_generic(cd->net, nfsd_net_id);
 897	struct svc_expkey *ek = exp_find_key(nn->svc_expkey_cache, clp, fsid_type, fsidv, reqp);
 898	if (IS_ERR(ek))
 899		return ERR_CAST(ek);
 900
 901	exp = exp_get_by_name(cd, clp, &ek->ek_path, reqp);
 902	cache_put(&ek->h, nn->svc_expkey_cache);
 903
 904	if (IS_ERR(exp))
 905		return ERR_CAST(exp);
 906	return exp;
 907}
 908
 909__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp)
 910{
 911	struct exp_flavor_info *f;
 912	struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
 913
 914	/* legacy gss-only clients are always OK: */
 915	if (exp->ex_client == rqstp->rq_gssclient)
 916		return 0;
 917	/* ip-address based client; check sec= export option: */
 918	for (f = exp->ex_flavors; f < end; f++) {
 919		if (f->pseudoflavor == rqstp->rq_cred.cr_flavor)
 920			return 0;
 921	}
 922	/* defaults in absence of sec= options: */
 923	if (exp->ex_nflavors == 0) {
 924		if (rqstp->rq_cred.cr_flavor == RPC_AUTH_NULL ||
 925		    rqstp->rq_cred.cr_flavor == RPC_AUTH_UNIX)
 926			return 0;
 927	}
 928	return nfserr_wrongsec;
 929}
 930
 931/*
 932 * Uses rq_client and rq_gssclient to find an export; uses rq_client (an
 933 * auth_unix client) if it's available and has secinfo information;
 934 * otherwise, will try to use rq_gssclient.
 935 *
 936 * Called from functions that handle requests; functions that do work on
 937 * behalf of mountd are passed a single client name to use, and should
 938 * use exp_get_by_name() or exp_find().
 939 */
 940struct svc_export *
 941rqst_exp_get_by_name(struct svc_rqst *rqstp, struct path *path)
 942{
 943	struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
 944	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 945	struct cache_detail *cd = nn->svc_export_cache;
 946
 947	if (rqstp->rq_client == NULL)
 948		goto gss;
 949
 950	/* First try the auth_unix client: */
 951	exp = exp_get_by_name(cd, rqstp->rq_client, path, &rqstp->rq_chandle);
 952	if (PTR_ERR(exp) == -ENOENT)
 953		goto gss;
 954	if (IS_ERR(exp))
 955		return exp;
 956	/* If it has secinfo, assume there are no gss/... clients */
 957	if (exp->ex_nflavors > 0)
 958		return exp;
 959gss:
 960	/* Otherwise, try falling back on gss client */
 961	if (rqstp->rq_gssclient == NULL)
 962		return exp;
 963	gssexp = exp_get_by_name(cd, rqstp->rq_gssclient, path, &rqstp->rq_chandle);
 964	if (PTR_ERR(gssexp) == -ENOENT)
 965		return exp;
 966	if (!IS_ERR(exp))
 967		exp_put(exp);
 968	return gssexp;
 969}
 970
 971struct svc_export *
 972rqst_exp_find(struct svc_rqst *rqstp, int fsid_type, u32 *fsidv)
 973{
 974	struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
 975	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 976	struct cache_detail *cd = nn->svc_export_cache;
 977
 978	if (rqstp->rq_client == NULL)
 979		goto gss;
 980
 981	/* First try the auth_unix client: */
 982	exp = exp_find(cd, rqstp->rq_client, fsid_type,
 983		       fsidv, &rqstp->rq_chandle);
 984	if (PTR_ERR(exp) == -ENOENT)
 985		goto gss;
 986	if (IS_ERR(exp))
 987		return exp;
 988	/* If it has secinfo, assume there are no gss/... clients */
 989	if (exp->ex_nflavors > 0)
 990		return exp;
 991gss:
 992	/* Otherwise, try falling back on gss client */
 993	if (rqstp->rq_gssclient == NULL)
 994		return exp;
 995	gssexp = exp_find(cd, rqstp->rq_gssclient, fsid_type, fsidv,
 996						&rqstp->rq_chandle);
 997	if (PTR_ERR(gssexp) == -ENOENT)
 998		return exp;
 999	if (!IS_ERR(exp))
1000		exp_put(exp);
1001	return gssexp;
1002}
1003
1004struct svc_export *
1005rqst_exp_parent(struct svc_rqst *rqstp, struct path *path)
1006{
1007	struct dentry *saved = dget(path->dentry);
1008	struct svc_export *exp = rqst_exp_get_by_name(rqstp, path);
1009
1010	while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
1011		struct dentry *parent = dget_parent(path->dentry);
1012		dput(path->dentry);
1013		path->dentry = parent;
1014		exp = rqst_exp_get_by_name(rqstp, path);
1015	}
1016	dput(path->dentry);
1017	path->dentry = saved;
1018	return exp;
1019}
1020
1021struct svc_export *rqst_find_fsidzero_export(struct svc_rqst *rqstp)
1022{
1023	u32 fsidv[2];
1024
1025	mk_fsid(FSID_NUM, fsidv, 0, 0, 0, NULL);
1026
1027	return rqst_exp_find(rqstp, FSID_NUM, fsidv);
1028}
1029
1030/*
1031 * Called when we need the filehandle for the root of the pseudofs,
1032 * for a given NFSv4 client.   The root is defined to be the
1033 * export point with fsid==0
1034 */
1035__be32
1036exp_pseudoroot(struct svc_rqst *rqstp, struct svc_fh *fhp)
1037{
1038	struct svc_export *exp;
1039	__be32 rv;
1040
1041	exp = rqst_find_fsidzero_export(rqstp);
1042	if (IS_ERR(exp))
1043		return nfserrno(PTR_ERR(exp));
1044	rv = fh_compose(fhp, exp, exp->ex_path.dentry, NULL);
1045	exp_put(exp);
1046	return rv;
1047}
1048
1049/* Iterator */
1050
1051static void *e_start(struct seq_file *m, loff_t *pos)
1052	__acquires(((struct cache_detail *)m->private)->hash_lock)
1053{
1054	loff_t n = *pos;
1055	unsigned hash, export;
1056	struct cache_head *ch;
1057	struct cache_detail *cd = m->private;
1058	struct cache_head **export_table = cd->hash_table;
1059
1060	read_lock(&cd->hash_lock);
1061	if (!n--)
1062		return SEQ_START_TOKEN;
1063	hash = n >> 32;
1064	export = n & ((1LL<<32) - 1);
1065
1066	
1067	for (ch=export_table[hash]; ch; ch=ch->next)
1068		if (!export--)
1069			return ch;
1070	n &= ~((1LL<<32) - 1);
1071	do {
1072		hash++;
1073		n += 1LL<<32;
1074	} while(hash < EXPORT_HASHMAX && export_table[hash]==NULL);
1075	if (hash >= EXPORT_HASHMAX)
1076		return NULL;
1077	*pos = n+1;
1078	return export_table[hash];
1079}
1080
1081static void *e_next(struct seq_file *m, void *p, loff_t *pos)
1082{
1083	struct cache_head *ch = p;
1084	int hash = (*pos >> 32);
1085	struct cache_detail *cd = m->private;
1086	struct cache_head **export_table = cd->hash_table;
1087
1088	if (p == SEQ_START_TOKEN)
1089		hash = 0;
1090	else if (ch->next == NULL) {
1091		hash++;
1092		*pos += 1LL<<32;
1093	} else {
1094		++*pos;
1095		return ch->next;
1096	}
1097	*pos &= ~((1LL<<32) - 1);
1098	while (hash < EXPORT_HASHMAX && export_table[hash] == NULL) {
1099		hash++;
1100		*pos += 1LL<<32;
1101	}
1102	if (hash >= EXPORT_HASHMAX)
1103		return NULL;
1104	++*pos;
1105	return export_table[hash];
1106}
1107
1108static void e_stop(struct seq_file *m, void *p)
1109	__releases(((struct cache_detail *)m->private)->hash_lock)
1110{
1111	struct cache_detail *cd = m->private;
1112
1113	read_unlock(&cd->hash_lock);
1114}
1115
1116static struct flags {
1117	int flag;
1118	char *name[2];
1119} expflags[] = {
1120	{ NFSEXP_READONLY, {"ro", "rw"}},
1121	{ NFSEXP_INSECURE_PORT, {"insecure", ""}},
1122	{ NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
1123	{ NFSEXP_ALLSQUASH, {"all_squash", ""}},
1124	{ NFSEXP_ASYNC, {"async", "sync"}},
1125	{ NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
1126	{ NFSEXP_NOHIDE, {"nohide", ""}},
1127	{ NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
1128	{ NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
1129	{ NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
1130	{ NFSEXP_V4ROOT, {"v4root", ""}},
1131	{ 0, {"", ""}}
1132};
1133
1134static void show_expflags(struct seq_file *m, int flags, int mask)
1135{
1136	struct flags *flg;
1137	int state, first = 0;
1138
1139	for (flg = expflags; flg->flag; flg++) {
1140		if (flg->flag & ~mask)
1141			continue;
1142		state = (flg->flag & flags) ? 0 : 1;
1143		if (*flg->name[state])
1144			seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
1145	}
1146}
1147
1148static void show_secinfo_flags(struct seq_file *m, int flags)
1149{
1150	seq_printf(m, ",");
1151	show_expflags(m, flags, NFSEXP_SECINFO_FLAGS);
1152}
1153
1154static bool secinfo_flags_equal(int f, int g)
1155{
1156	f &= NFSEXP_SECINFO_FLAGS;
1157	g &= NFSEXP_SECINFO_FLAGS;
1158	return f == g;
1159}
1160
1161static int show_secinfo_run(struct seq_file *m, struct exp_flavor_info **fp, struct exp_flavor_info *end)
1162{
1163	int flags;
1164
1165	flags = (*fp)->flags;
1166	seq_printf(m, ",sec=%d", (*fp)->pseudoflavor);
1167	(*fp)++;
1168	while (*fp != end && secinfo_flags_equal(flags, (*fp)->flags)) {
1169		seq_printf(m, ":%d", (*fp)->pseudoflavor);
1170		(*fp)++;
1171	}
1172	return flags;
1173}
1174
1175static void show_secinfo(struct seq_file *m, struct svc_export *exp)
1176{
1177	struct exp_flavor_info *f;
1178	struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
1179	int flags;
1180
1181	if (exp->ex_nflavors == 0)
1182		return;
1183	f = exp->ex_flavors;
1184	flags = show_secinfo_run(m, &f, end);
1185	if (!secinfo_flags_equal(flags, exp->ex_flags))
1186		show_secinfo_flags(m, flags);
1187	while (f != end) {
1188		flags = show_secinfo_run(m, &f, end);
1189		show_secinfo_flags(m, flags);
1190	}
1191}
1192
1193static void exp_flags(struct seq_file *m, int flag, int fsid,
1194		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fsloc)
1195{
1196	show_expflags(m, flag, NFSEXP_ALLFLAGS);
1197	if (flag & NFSEXP_FSID)
1198		seq_printf(m, ",fsid=%d", fsid);
1199	if (!uid_eq(anonu, make_kuid(&init_user_ns, (uid_t)-2)) &&
1200	    !uid_eq(anonu, make_kuid(&init_user_ns, 0x10000-2)))
1201		seq_printf(m, ",anonuid=%u", from_kuid(&init_user_ns, anonu));
1202	if (!gid_eq(anong, make_kgid(&init_user_ns, (gid_t)-2)) &&
1203	    !gid_eq(anong, make_kgid(&init_user_ns, 0x10000-2)))
1204		seq_printf(m, ",anongid=%u", from_kgid(&init_user_ns, anong));
1205	if (fsloc && fsloc->locations_count > 0) {
1206		char *loctype = (fsloc->migrated) ? "refer" : "replicas";
1207		int i;
1208
1209		seq_printf(m, ",%s=", loctype);
1210		seq_escape(m, fsloc->locations[0].path, ",;@ \t\n\\");
1211		seq_putc(m, '@');
1212		seq_escape(m, fsloc->locations[0].hosts, ",;@ \t\n\\");
1213		for (i = 1; i < fsloc->locations_count; i++) {
1214			seq_putc(m, ';');
1215			seq_escape(m, fsloc->locations[i].path, ",;@ \t\n\\");
1216			seq_putc(m, '@');
1217			seq_escape(m, fsloc->locations[i].hosts, ",;@ \t\n\\");
1218		}
1219	}
1220}
1221
1222static int e_show(struct seq_file *m, void *p)
1223{
1224	struct cache_head *cp = p;
1225	struct svc_export *exp = container_of(cp, struct svc_export, h);
1226	struct cache_detail *cd = m->private;
1227
1228	if (p == SEQ_START_TOKEN) {
1229		seq_puts(m, "# Version 1.1\n");
1230		seq_puts(m, "# Path Client(Flags) # IPs\n");
1231		return 0;
1232	}
1233
1234	cache_get(&exp->h);
1235	if (cache_check(cd, &exp->h, NULL))
1236		return 0;
1237	exp_put(exp);
1238	return svc_export_show(m, cd, cp);
1239}
1240
1241const struct seq_operations nfs_exports_op = {
1242	.start	= e_start,
1243	.next	= e_next,
1244	.stop	= e_stop,
1245	.show	= e_show,
1246};
1247
1248/*
1249 * Initialize the exports module.
1250 */
1251int
1252nfsd_export_init(struct net *net)
1253{
1254	int rv;
1255	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1256
1257	dprintk("nfsd: initializing export module (net: %p).\n", net);
1258
1259	nn->svc_export_cache = cache_create_net(&svc_export_cache_template, net);
1260	if (IS_ERR(nn->svc_export_cache))
1261		return PTR_ERR(nn->svc_export_cache);
1262	rv = cache_register_net(nn->svc_export_cache, net);
1263	if (rv)
1264		goto destroy_export_cache;
1265
1266	nn->svc_expkey_cache = cache_create_net(&svc_expkey_cache_template, net);
1267	if (IS_ERR(nn->svc_expkey_cache)) {
1268		rv = PTR_ERR(nn->svc_expkey_cache);
1269		goto unregister_export_cache;
1270	}
1271	rv = cache_register_net(nn->svc_expkey_cache, net);
1272	if (rv)
1273		goto destroy_expkey_cache;
1274	return 0;
1275
1276destroy_expkey_cache:
1277	cache_destroy_net(nn->svc_expkey_cache, net);
1278unregister_export_cache:
1279	cache_unregister_net(nn->svc_export_cache, net);
1280destroy_export_cache:
1281	cache_destroy_net(nn->svc_export_cache, net);
1282	return rv;
1283}
1284
1285/*
1286 * Flush exports table - called when last nfsd thread is killed
1287 */
1288void
1289nfsd_export_flush(struct net *net)
1290{
1291	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1292
1293	cache_purge(nn->svc_expkey_cache);
1294	cache_purge(nn->svc_export_cache);
1295}
1296
1297/*
1298 * Shutdown the exports module.
1299 */
1300void
1301nfsd_export_shutdown(struct net *net)
1302{
1303	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1304
1305	dprintk("nfsd: shutting down export module (net: %p).\n", net);
1306
1307	cache_unregister_net(nn->svc_expkey_cache, net);
1308	cache_unregister_net(nn->svc_export_cache, net);
1309	cache_destroy_net(nn->svc_expkey_cache, net);
1310	cache_destroy_net(nn->svc_export_cache, net);
1311	svcauth_unix_purge(net);
1312
1313	dprintk("nfsd: export shutdown complete (net: %p).\n", net);
1314}
   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
  26#define NFSDDBG_FACILITY	NFSDDBG_EXPORT
  27
  28/*
  29 * We have two caches.
  30 * One maps client+vfsmnt+dentry to export options - the export map
  31 * The other maps client+filehandle-fragment to export options. - the expkey map
  32 *
  33 * The export options are actually stored in the first map, and the
  34 * second map contains a reference to the entry in the first map.
  35 */
  36
  37#define	EXPKEY_HASHBITS		8
  38#define	EXPKEY_HASHMAX		(1 << EXPKEY_HASHBITS)
  39#define	EXPKEY_HASHMASK		(EXPKEY_HASHMAX -1)
  40
  41static void expkey_put(struct kref *ref)
  42{
  43	struct svc_expkey *key = container_of(ref, struct svc_expkey, h.ref);
  44
  45	if (test_bit(CACHE_VALID, &key->h.flags) &&
  46	    !test_bit(CACHE_NEGATIVE, &key->h.flags))
  47		path_put(&key->ek_path);
  48	auth_domain_put(key->ek_client);
  49	kfree(key);
  50}
  51
  52static void expkey_request(struct cache_detail *cd,
  53			   struct cache_head *h,
  54			   char **bpp, int *blen)
  55{
  56	/* client fsidtype \xfsid */
  57	struct svc_expkey *ek = container_of(h, struct svc_expkey, h);
  58	char type[5];
  59
  60	qword_add(bpp, blen, ek->ek_client->name);
  61	snprintf(type, 5, "%d", ek->ek_fsidtype);
  62	qword_add(bpp, blen, type);
  63	qword_addhex(bpp, blen, (char*)ek->ek_fsid, key_len(ek->ek_fsidtype));
  64	(*bpp)[-1] = '\n';
  65}
  66
  67static struct svc_expkey *svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
  68					    struct svc_expkey *old);
  69static struct svc_expkey *svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *);
  70
  71static int expkey_parse(struct cache_detail *cd, char *mesg, int mlen)
  72{
  73	/* client fsidtype fsid expiry [path] */
  74	char *buf;
  75	int len;
  76	struct auth_domain *dom = NULL;
  77	int err;
  78	int fsidtype;
  79	char *ep;
  80	struct svc_expkey key;
  81	struct svc_expkey *ek = NULL;
  82
  83	if (mesg[mlen - 1] != '\n')
  84		return -EINVAL;
  85	mesg[mlen-1] = 0;
  86
  87	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
  88	err = -ENOMEM;
  89	if (!buf)
  90		goto out;
  91
  92	err = -EINVAL;
  93	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
  94		goto out;
  95
  96	err = -ENOENT;
  97	dom = auth_domain_find(buf);
  98	if (!dom)
  99		goto out;
 100	dprintk("found domain %s\n", buf);
 101
 102	err = -EINVAL;
 103	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 104		goto out;
 105	fsidtype = simple_strtoul(buf, &ep, 10);
 106	if (*ep)
 107		goto out;
 108	dprintk("found fsidtype %d\n", fsidtype);
 109	if (key_len(fsidtype)==0) /* invalid type */
 110		goto out;
 111	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 112		goto out;
 113	dprintk("found fsid length %d\n", len);
 114	if (len != key_len(fsidtype))
 115		goto out;
 116
 117	/* OK, we seem to have a valid key */
 118	key.h.flags = 0;
 119	key.h.expiry_time = get_expiry(&mesg);
 120	if (key.h.expiry_time == 0)
 121		goto out;
 122
 123	key.ek_client = dom;	
 124	key.ek_fsidtype = fsidtype;
 125	memcpy(key.ek_fsid, buf, len);
 126
 127	ek = svc_expkey_lookup(cd, &key);
 128	err = -ENOMEM;
 129	if (!ek)
 130		goto out;
 131
 132	/* now we want a pathname, or empty meaning NEGATIVE  */
 133	err = -EINVAL;
 134	len = qword_get(&mesg, buf, PAGE_SIZE);
 135	if (len < 0)
 136		goto out;
 137	dprintk("Path seems to be <%s>\n", buf);
 138	err = 0;
 139	if (len == 0) {
 140		set_bit(CACHE_NEGATIVE, &key.h.flags);
 141		ek = svc_expkey_update(cd, &key, ek);
 142		if (!ek)
 143			err = -ENOMEM;
 144	} else {
 145		err = kern_path(buf, 0, &key.ek_path);
 146		if (err)
 147			goto out;
 148
 149		dprintk("Found the path %s\n", buf);
 150
 151		ek = svc_expkey_update(cd, &key, ek);
 152		if (!ek)
 153			err = -ENOMEM;
 154		path_put(&key.ek_path);
 155	}
 156	cache_flush();
 157 out:
 158	if (ek)
 159		cache_put(&ek->h, cd);
 160	if (dom)
 161		auth_domain_put(dom);
 162	kfree(buf);
 163	return err;
 164}
 165
 166static int expkey_show(struct seq_file *m,
 167		       struct cache_detail *cd,
 168		       struct cache_head *h)
 169{
 170	struct svc_expkey *ek ;
 171	int i;
 172
 173	if (h ==NULL) {
 174		seq_puts(m, "#domain fsidtype fsid [path]\n");
 175		return 0;
 176	}
 177	ek = container_of(h, struct svc_expkey, h);
 178	seq_printf(m, "%s %d 0x", ek->ek_client->name,
 179		   ek->ek_fsidtype);
 180	for (i=0; i < key_len(ek->ek_fsidtype)/4; i++)
 181		seq_printf(m, "%08x", ek->ek_fsid[i]);
 182	if (test_bit(CACHE_VALID, &h->flags) && 
 183	    !test_bit(CACHE_NEGATIVE, &h->flags)) {
 184		seq_printf(m, " ");
 185		seq_path(m, &ek->ek_path, "\\ \t\n");
 186	}
 187	seq_printf(m, "\n");
 188	return 0;
 189}
 190
 191static inline int expkey_match (struct cache_head *a, struct cache_head *b)
 192{
 193	struct svc_expkey *orig = container_of(a, struct svc_expkey, h);
 194	struct svc_expkey *new = container_of(b, struct svc_expkey, h);
 195
 196	if (orig->ek_fsidtype != new->ek_fsidtype ||
 197	    orig->ek_client != new->ek_client ||
 198	    memcmp(orig->ek_fsid, new->ek_fsid, key_len(orig->ek_fsidtype)) != 0)
 199		return 0;
 200	return 1;
 201}
 202
 203static inline void expkey_init(struct cache_head *cnew,
 204				   struct cache_head *citem)
 205{
 206	struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
 207	struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
 208
 209	kref_get(&item->ek_client->ref);
 210	new->ek_client = item->ek_client;
 211	new->ek_fsidtype = item->ek_fsidtype;
 212
 213	memcpy(new->ek_fsid, item->ek_fsid, sizeof(new->ek_fsid));
 214}
 215
 216static inline void expkey_update(struct cache_head *cnew,
 217				   struct cache_head *citem)
 218{
 219	struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
 220	struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
 221
 222	new->ek_path = item->ek_path;
 223	path_get(&item->ek_path);
 224}
 225
 226static struct cache_head *expkey_alloc(void)
 227{
 228	struct svc_expkey *i = kmalloc(sizeof(*i), GFP_KERNEL);
 229	if (i)
 230		return &i->h;
 231	else
 232		return NULL;
 233}
 234
 235static const struct cache_detail svc_expkey_cache_template = {
 236	.owner		= THIS_MODULE,
 237	.hash_size	= EXPKEY_HASHMAX,
 238	.name		= "nfsd.fh",
 239	.cache_put	= expkey_put,
 240	.cache_request	= expkey_request,
 241	.cache_parse	= expkey_parse,
 242	.cache_show	= expkey_show,
 243	.match		= expkey_match,
 244	.init		= expkey_init,
 245	.update       	= expkey_update,
 246	.alloc		= expkey_alloc,
 247};
 248
 249static int
 250svc_expkey_hash(struct svc_expkey *item)
 251{
 252	int hash = item->ek_fsidtype;
 253	char * cp = (char*)item->ek_fsid;
 254	int len = key_len(item->ek_fsidtype);
 255
 256	hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
 257	hash ^= hash_ptr(item->ek_client, EXPKEY_HASHBITS);
 258	hash &= EXPKEY_HASHMASK;
 259	return hash;
 260}
 261
 262static struct svc_expkey *
 263svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *item)
 264{
 265	struct cache_head *ch;
 266	int hash = svc_expkey_hash(item);
 267
 268	ch = sunrpc_cache_lookup(cd, &item->h, hash);
 269	if (ch)
 270		return container_of(ch, struct svc_expkey, h);
 271	else
 272		return NULL;
 273}
 274
 275static struct svc_expkey *
 276svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
 277		  struct svc_expkey *old)
 278{
 279	struct cache_head *ch;
 280	int hash = svc_expkey_hash(new);
 281
 282	ch = sunrpc_cache_update(cd, &new->h, &old->h, hash);
 283	if (ch)
 284		return container_of(ch, struct svc_expkey, h);
 285	else
 286		return NULL;
 287}
 288
 289
 290#define	EXPORT_HASHBITS		8
 291#define	EXPORT_HASHMAX		(1<< EXPORT_HASHBITS)
 292
 293static void nfsd4_fslocs_free(struct nfsd4_fs_locations *fsloc)
 294{
 295	struct nfsd4_fs_location *locations = fsloc->locations;
 296	int i;
 297
 298	if (!locations)
 299		return;
 300
 301	for (i = 0; i < fsloc->locations_count; i++) {
 302		kfree(locations[i].path);
 303		kfree(locations[i].hosts);
 304	}
 305
 306	kfree(locations);
 307	fsloc->locations = NULL;
 308}
 309
 310static void svc_export_put(struct kref *ref)
 311{
 312	struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
 313	path_put(&exp->ex_path);
 314	auth_domain_put(exp->ex_client);
 315	nfsd4_fslocs_free(&exp->ex_fslocs);
 316	kfree(exp->ex_uuid);
 317	kfree(exp);
 318}
 319
 320static void svc_export_request(struct cache_detail *cd,
 321			       struct cache_head *h,
 322			       char **bpp, int *blen)
 323{
 324	/*  client path */
 325	struct svc_export *exp = container_of(h, struct svc_export, h);
 326	char *pth;
 327
 328	qword_add(bpp, blen, exp->ex_client->name);
 329	pth = d_path(&exp->ex_path, *bpp, *blen);
 330	if (IS_ERR(pth)) {
 331		/* is this correct? */
 332		(*bpp)[0] = '\n';
 333		return;
 334	}
 335	qword_add(bpp, blen, pth);
 336	(*bpp)[-1] = '\n';
 337}
 338
 339static struct svc_export *svc_export_update(struct svc_export *new,
 340					    struct svc_export *old);
 341static struct svc_export *svc_export_lookup(struct svc_export *);
 342
 343static int check_export(struct inode *inode, int *flags, unsigned char *uuid)
 344{
 345
 346	/*
 347	 * We currently export only dirs, regular files, and (for v4
 348	 * pseudoroot) symlinks.
 349	 */
 350	if (!S_ISDIR(inode->i_mode) &&
 351	    !S_ISLNK(inode->i_mode) &&
 352	    !S_ISREG(inode->i_mode))
 353		return -ENOTDIR;
 354
 355	/*
 356	 * Mountd should never pass down a writeable V4ROOT export, but,
 357	 * just to make sure:
 358	 */
 359	if (*flags & NFSEXP_V4ROOT)
 360		*flags |= NFSEXP_READONLY;
 361
 362	/* There are two requirements on a filesystem to be exportable.
 363	 * 1:  We must be able to identify the filesystem from a number.
 364	 *       either a device number (so FS_REQUIRES_DEV needed)
 365	 *       or an FSID number (so NFSEXP_FSID or ->uuid is needed).
 366	 * 2:  We must be able to find an inode from a filehandle.
 367	 *       This means that s_export_op must be set.
 368	 */
 369	if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) &&
 370	    !(*flags & NFSEXP_FSID) &&
 371	    uuid == NULL) {
 372		dprintk("exp_export: export of non-dev fs without fsid\n");
 373		return -EINVAL;
 374	}
 375
 376	if (!inode->i_sb->s_export_op ||
 377	    !inode->i_sb->s_export_op->fh_to_dentry) {
 378		dprintk("exp_export: export of invalid fs type.\n");
 379		return -EINVAL;
 380	}
 381
 382	return 0;
 383
 384}
 385
 386#ifdef CONFIG_NFSD_V4
 387
 388static int
 389fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc)
 390{
 391	int len;
 392	int migrated, i, err;
 393
 394	/* more than one fsloc */
 395	if (fsloc->locations)
 396		return -EINVAL;
 397
 398	/* listsize */
 399	err = get_uint(mesg, &fsloc->locations_count);
 400	if (err)
 401		return err;
 402	if (fsloc->locations_count > MAX_FS_LOCATIONS)
 403		return -EINVAL;
 404	if (fsloc->locations_count == 0)
 405		return 0;
 406
 407	fsloc->locations = kzalloc(fsloc->locations_count
 408			* sizeof(struct nfsd4_fs_location), GFP_KERNEL);
 409	if (!fsloc->locations)
 410		return -ENOMEM;
 411	for (i=0; i < fsloc->locations_count; i++) {
 412		/* colon separated host list */
 413		err = -EINVAL;
 414		len = qword_get(mesg, buf, PAGE_SIZE);
 415		if (len <= 0)
 416			goto out_free_all;
 417		err = -ENOMEM;
 418		fsloc->locations[i].hosts = kstrdup(buf, GFP_KERNEL);
 419		if (!fsloc->locations[i].hosts)
 420			goto out_free_all;
 421		err = -EINVAL;
 422		/* slash separated path component list */
 423		len = qword_get(mesg, buf, PAGE_SIZE);
 424		if (len <= 0)
 425			goto out_free_all;
 426		err = -ENOMEM;
 427		fsloc->locations[i].path = kstrdup(buf, GFP_KERNEL);
 428		if (!fsloc->locations[i].path)
 429			goto out_free_all;
 430	}
 431	/* migrated */
 432	err = get_int(mesg, &migrated);
 433	if (err)
 434		goto out_free_all;
 435	err = -EINVAL;
 436	if (migrated < 0 || migrated > 1)
 437		goto out_free_all;
 438	fsloc->migrated = migrated;
 439	return 0;
 440out_free_all:
 441	nfsd4_fslocs_free(fsloc);
 442	return err;
 443}
 444
 445static int secinfo_parse(char **mesg, char *buf, struct svc_export *exp)
 446{
 447	struct exp_flavor_info *f;
 448	u32 listsize;
 449	int err;
 450
 451	/* more than one secinfo */
 452	if (exp->ex_nflavors)
 453		return -EINVAL;
 454
 455	err = get_uint(mesg, &listsize);
 456	if (err)
 457		return err;
 458	if (listsize > MAX_SECINFO_LIST)
 459		return -EINVAL;
 460
 461	for (f = exp->ex_flavors; f < exp->ex_flavors + listsize; f++) {
 462		err = get_uint(mesg, &f->pseudoflavor);
 463		if (err)
 464			return err;
 465		/*
 466		 * XXX: It would be nice to also check whether this
 467		 * pseudoflavor is supported, so we can discover the
 468		 * problem at export time instead of when a client fails
 469		 * to authenticate.
 470		 */
 471		err = get_uint(mesg, &f->flags);
 472		if (err)
 473			return err;
 474		/* Only some flags are allowed to differ between flavors: */
 475		if (~NFSEXP_SECINFO_FLAGS & (f->flags ^ exp->ex_flags))
 476			return -EINVAL;
 477	}
 478	exp->ex_nflavors = listsize;
 479	return 0;
 480}
 481
 482#else /* CONFIG_NFSD_V4 */
 483static inline int
 484fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc){return 0;}
 485static inline int
 486secinfo_parse(char **mesg, char *buf, struct svc_export *exp) { return 0; }
 487#endif
 488
 489static inline int
 490nfsd_uuid_parse(char **mesg, char *buf, unsigned char **puuid)
 491{
 492	int len;
 493
 494	/* more than one uuid */
 495	if (*puuid)
 496		return -EINVAL;
 497
 498	/* expect a 16 byte uuid encoded as \xXXXX... */
 499	len = qword_get(mesg, buf, PAGE_SIZE);
 500	if (len != EX_UUID_LEN)
 501		return -EINVAL;
 502
 503	*puuid = kmemdup(buf, EX_UUID_LEN, GFP_KERNEL);
 504	if (*puuid == NULL)
 505		return -ENOMEM;
 506
 507	return 0;
 508}
 509
 510static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
 511{
 512	/* client path expiry [flags anonuid anongid fsid] */
 513	char *buf;
 514	int len;
 515	int err;
 516	struct auth_domain *dom = NULL;
 517	struct svc_export exp = {}, *expp;
 518	int an_int;
 519
 520	if (mesg[mlen-1] != '\n')
 521		return -EINVAL;
 522	mesg[mlen-1] = 0;
 523
 524	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 525	if (!buf)
 526		return -ENOMEM;
 527
 528	/* client */
 529	err = -EINVAL;
 530	len = qword_get(&mesg, buf, PAGE_SIZE);
 531	if (len <= 0)
 532		goto out;
 533
 534	err = -ENOENT;
 535	dom = auth_domain_find(buf);
 536	if (!dom)
 537		goto out;
 538
 539	/* path */
 540	err = -EINVAL;
 541	if ((len = qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 542		goto out1;
 543
 544	err = kern_path(buf, 0, &exp.ex_path);
 545	if (err)
 546		goto out1;
 547
 548	exp.ex_client = dom;
 549	exp.cd = cd;
 550	exp.ex_devid_map = NULL;
 551
 552	/* expiry */
 553	err = -EINVAL;
 554	exp.h.expiry_time = get_expiry(&mesg);
 555	if (exp.h.expiry_time == 0)
 556		goto out3;
 557
 558	/* flags */
 559	err = get_int(&mesg, &an_int);
 560	if (err == -ENOENT) {
 561		err = 0;
 562		set_bit(CACHE_NEGATIVE, &exp.h.flags);
 563	} else {
 564		if (err || an_int < 0)
 565			goto out3;
 566		exp.ex_flags= an_int;
 567	
 568		/* anon uid */
 569		err = get_int(&mesg, &an_int);
 570		if (err)
 571			goto out3;
 572		exp.ex_anon_uid= make_kuid(&init_user_ns, an_int);
 573
 574		/* anon gid */
 575		err = get_int(&mesg, &an_int);
 576		if (err)
 577			goto out3;
 578		exp.ex_anon_gid= make_kgid(&init_user_ns, an_int);
 579
 580		/* fsid */
 581		err = get_int(&mesg, &an_int);
 582		if (err)
 583			goto out3;
 584		exp.ex_fsid = an_int;
 585
 586		while ((len = qword_get(&mesg, buf, PAGE_SIZE)) > 0) {
 587			if (strcmp(buf, "fsloc") == 0)
 588				err = fsloc_parse(&mesg, buf, &exp.ex_fslocs);
 589			else if (strcmp(buf, "uuid") == 0)
 590				err = nfsd_uuid_parse(&mesg, buf, &exp.ex_uuid);
 591			else if (strcmp(buf, "secinfo") == 0)
 592				err = secinfo_parse(&mesg, buf, &exp);
 593			else
 594				/* quietly ignore unknown words and anything
 595				 * following. Newer user-space can try to set
 596				 * new values, then see what the result was.
 597				 */
 598				break;
 599			if (err)
 600				goto out4;
 601		}
 602
 603		err = check_export(d_inode(exp.ex_path.dentry), &exp.ex_flags,
 604				   exp.ex_uuid);
 605		if (err)
 606			goto out4;
 607		/*
 608		 * No point caching this if it would immediately expire.
 609		 * Also, this protects exportfs's dummy export from the
 610		 * anon_uid/anon_gid checks:
 611		 */
 612		if (exp.h.expiry_time < seconds_since_boot())
 613			goto out4;
 614		/*
 615		 * For some reason exportfs has been passing down an
 616		 * invalid (-1) uid & gid on the "dummy" export which it
 617		 * uses to test export support.  To make sure exportfs
 618		 * sees errors from check_export we therefore need to
 619		 * delay these checks till after check_export:
 620		 */
 621		err = -EINVAL;
 622		if (!uid_valid(exp.ex_anon_uid))
 623			goto out4;
 624		if (!gid_valid(exp.ex_anon_gid))
 625			goto out4;
 626		err = 0;
 627
 628		nfsd4_setup_layout_type(&exp);
 629	}
 630
 631	expp = svc_export_lookup(&exp);
 632	if (expp)
 633		expp = svc_export_update(&exp, expp);
 634	else
 635		err = -ENOMEM;
 636	cache_flush();
 637	if (expp == NULL)
 638		err = -ENOMEM;
 639	else
 640		exp_put(expp);
 641out4:
 642	nfsd4_fslocs_free(&exp.ex_fslocs);
 643	kfree(exp.ex_uuid);
 644out3:
 645	path_put(&exp.ex_path);
 646out1:
 647	auth_domain_put(dom);
 648out:
 649	kfree(buf);
 650	return err;
 651}
 652
 653static void exp_flags(struct seq_file *m, int flag, int fsid,
 654		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fslocs);
 655static void show_secinfo(struct seq_file *m, struct svc_export *exp);
 656
 657static int svc_export_show(struct seq_file *m,
 658			   struct cache_detail *cd,
 659			   struct cache_head *h)
 660{
 661	struct svc_export *exp ;
 662
 663	if (h ==NULL) {
 664		seq_puts(m, "#path domain(flags)\n");
 665		return 0;
 666	}
 667	exp = container_of(h, struct svc_export, h);
 668	seq_path(m, &exp->ex_path, " \t\n\\");
 669	seq_putc(m, '\t');
 670	seq_escape(m, exp->ex_client->name, " \t\n\\");
 671	seq_putc(m, '(');
 672	if (test_bit(CACHE_VALID, &h->flags) && 
 673	    !test_bit(CACHE_NEGATIVE, &h->flags)) {
 674		exp_flags(m, exp->ex_flags, exp->ex_fsid,
 675			  exp->ex_anon_uid, exp->ex_anon_gid, &exp->ex_fslocs);
 676		if (exp->ex_uuid) {
 677			int i;
 678			seq_puts(m, ",uuid=");
 679			for (i = 0; i < EX_UUID_LEN; i++) {
 680				if ((i&3) == 0 && i)
 681					seq_putc(m, ':');
 682				seq_printf(m, "%02x", exp->ex_uuid[i]);
 683			}
 684		}
 685		show_secinfo(m, exp);
 686	}
 687	seq_puts(m, ")\n");
 688	return 0;
 689}
 690static int svc_export_match(struct cache_head *a, struct cache_head *b)
 691{
 692	struct svc_export *orig = container_of(a, struct svc_export, h);
 693	struct svc_export *new = container_of(b, struct svc_export, h);
 694	return orig->ex_client == new->ex_client &&
 695		path_equal(&orig->ex_path, &new->ex_path);
 696}
 697
 698static void svc_export_init(struct cache_head *cnew, struct cache_head *citem)
 699{
 700	struct svc_export *new = container_of(cnew, struct svc_export, h);
 701	struct svc_export *item = container_of(citem, struct svc_export, h);
 702
 703	kref_get(&item->ex_client->ref);
 704	new->ex_client = item->ex_client;
 705	new->ex_path = item->ex_path;
 706	path_get(&item->ex_path);
 707	new->ex_fslocs.locations = NULL;
 708	new->ex_fslocs.locations_count = 0;
 709	new->ex_fslocs.migrated = 0;
 710	new->ex_layout_types = 0;
 711	new->ex_uuid = NULL;
 712	new->cd = item->cd;
 713}
 714
 715static void export_update(struct cache_head *cnew, struct cache_head *citem)
 716{
 717	struct svc_export *new = container_of(cnew, struct svc_export, h);
 718	struct svc_export *item = container_of(citem, struct svc_export, h);
 719	int i;
 720
 721	new->ex_flags = item->ex_flags;
 722	new->ex_anon_uid = item->ex_anon_uid;
 723	new->ex_anon_gid = item->ex_anon_gid;
 724	new->ex_fsid = item->ex_fsid;
 725	new->ex_devid_map = item->ex_devid_map;
 726	item->ex_devid_map = NULL;
 727	new->ex_uuid = item->ex_uuid;
 728	item->ex_uuid = NULL;
 729	new->ex_fslocs.locations = item->ex_fslocs.locations;
 730	item->ex_fslocs.locations = NULL;
 731	new->ex_fslocs.locations_count = item->ex_fslocs.locations_count;
 732	item->ex_fslocs.locations_count = 0;
 733	new->ex_fslocs.migrated = item->ex_fslocs.migrated;
 734	item->ex_fslocs.migrated = 0;
 735	new->ex_layout_types = item->ex_layout_types;
 736	new->ex_nflavors = item->ex_nflavors;
 737	for (i = 0; i < MAX_SECINFO_LIST; i++) {
 738		new->ex_flavors[i] = item->ex_flavors[i];
 739	}
 740}
 741
 742static struct cache_head *svc_export_alloc(void)
 743{
 744	struct svc_export *i = kmalloc(sizeof(*i), GFP_KERNEL);
 745	if (i)
 746		return &i->h;
 747	else
 748		return NULL;
 749}
 750
 751static const struct cache_detail svc_export_cache_template = {
 752	.owner		= THIS_MODULE,
 753	.hash_size	= EXPORT_HASHMAX,
 754	.name		= "nfsd.export",
 755	.cache_put	= svc_export_put,
 756	.cache_request	= svc_export_request,
 757	.cache_parse	= svc_export_parse,
 758	.cache_show	= svc_export_show,
 759	.match		= svc_export_match,
 760	.init		= svc_export_init,
 761	.update		= export_update,
 762	.alloc		= svc_export_alloc,
 763};
 764
 765static int
 766svc_export_hash(struct svc_export *exp)
 767{
 768	int hash;
 769
 770	hash = hash_ptr(exp->ex_client, EXPORT_HASHBITS);
 771	hash ^= hash_ptr(exp->ex_path.dentry, EXPORT_HASHBITS);
 772	hash ^= hash_ptr(exp->ex_path.mnt, EXPORT_HASHBITS);
 773	return hash;
 774}
 775
 776static struct svc_export *
 777svc_export_lookup(struct svc_export *exp)
 778{
 779	struct cache_head *ch;
 780	int hash = svc_export_hash(exp);
 781
 782	ch = sunrpc_cache_lookup(exp->cd, &exp->h, hash);
 783	if (ch)
 784		return container_of(ch, struct svc_export, h);
 785	else
 786		return NULL;
 787}
 788
 789static struct svc_export *
 790svc_export_update(struct svc_export *new, struct svc_export *old)
 791{
 792	struct cache_head *ch;
 793	int hash = svc_export_hash(old);
 794
 795	ch = sunrpc_cache_update(old->cd, &new->h, &old->h, hash);
 796	if (ch)
 797		return container_of(ch, struct svc_export, h);
 798	else
 799		return NULL;
 800}
 801
 802
 803static struct svc_expkey *
 804exp_find_key(struct cache_detail *cd, struct auth_domain *clp, int fsid_type,
 805	     u32 *fsidv, struct cache_req *reqp)
 806{
 807	struct svc_expkey key, *ek;
 808	int err;
 809	
 810	if (!clp)
 811		return ERR_PTR(-ENOENT);
 812
 813	key.ek_client = clp;
 814	key.ek_fsidtype = fsid_type;
 815	memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
 816
 817	ek = svc_expkey_lookup(cd, &key);
 818	if (ek == NULL)
 819		return ERR_PTR(-ENOMEM);
 820	err = cache_check(cd, &ek->h, reqp);
 821	if (err)
 822		return ERR_PTR(err);
 823	return ek;
 824}
 825
 826static struct svc_export *
 827exp_get_by_name(struct cache_detail *cd, struct auth_domain *clp,
 828		const struct path *path, struct cache_req *reqp)
 829{
 830	struct svc_export *exp, key;
 831	int err;
 832
 833	if (!clp)
 834		return ERR_PTR(-ENOENT);
 835
 836	key.ex_client = clp;
 837	key.ex_path = *path;
 838	key.cd = cd;
 839
 840	exp = svc_export_lookup(&key);
 841	if (exp == NULL)
 842		return ERR_PTR(-ENOMEM);
 843	err = cache_check(cd, &exp->h, reqp);
 844	if (err)
 845		return ERR_PTR(err);
 846	return exp;
 847}
 848
 849/*
 850 * Find the export entry for a given dentry.
 851 */
 852static struct svc_export *
 853exp_parent(struct cache_detail *cd, struct auth_domain *clp, struct path *path)
 854{
 855	struct dentry *saved = dget(path->dentry);
 856	struct svc_export *exp = exp_get_by_name(cd, clp, path, NULL);
 857
 858	while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
 859		struct dentry *parent = dget_parent(path->dentry);
 860		dput(path->dentry);
 861		path->dentry = parent;
 862		exp = exp_get_by_name(cd, clp, path, NULL);
 863	}
 864	dput(path->dentry);
 865	path->dentry = saved;
 866	return exp;
 867}
 868
 869
 870
 871/*
 872 * Obtain the root fh on behalf of a client.
 873 * This could be done in user space, but I feel that it adds some safety
 874 * since its harder to fool a kernel module than a user space program.
 875 */
 876int
 877exp_rootfh(struct net *net, struct auth_domain *clp, char *name,
 878	   struct knfsd_fh *f, int maxsize)
 879{
 880	struct svc_export	*exp;
 881	struct path		path;
 882	struct inode		*inode;
 883	struct svc_fh		fh;
 884	int			err;
 885	struct nfsd_net		*nn = net_generic(net, nfsd_net_id);
 886	struct cache_detail	*cd = nn->svc_export_cache;
 887
 888	err = -EPERM;
 889	/* NB: we probably ought to check that it's NUL-terminated */
 890	if (kern_path(name, 0, &path)) {
 891		printk("nfsd: exp_rootfh path not found %s", name);
 892		return err;
 893	}
 894	inode = d_inode(path.dentry);
 895
 896	dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
 897		 name, path.dentry, clp->name,
 898		 inode->i_sb->s_id, inode->i_ino);
 899	exp = exp_parent(cd, clp, &path);
 900	if (IS_ERR(exp)) {
 901		err = PTR_ERR(exp);
 902		goto out;
 903	}
 904
 905	/*
 906	 * fh must be initialized before calling fh_compose
 907	 */
 908	fh_init(&fh, maxsize);
 909	if (fh_compose(&fh, exp, path.dentry, NULL))
 910		err = -EINVAL;
 911	else
 912		err = 0;
 913	memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
 914	fh_put(&fh);
 915	exp_put(exp);
 916out:
 917	path_put(&path);
 918	return err;
 919}
 920
 921static struct svc_export *exp_find(struct cache_detail *cd,
 922				   struct auth_domain *clp, int fsid_type,
 923				   u32 *fsidv, struct cache_req *reqp)
 924{
 925	struct svc_export *exp;
 926	struct nfsd_net *nn = net_generic(cd->net, nfsd_net_id);
 927	struct svc_expkey *ek = exp_find_key(nn->svc_expkey_cache, clp, fsid_type, fsidv, reqp);
 928	if (IS_ERR(ek))
 929		return ERR_CAST(ek);
 930
 931	exp = exp_get_by_name(cd, clp, &ek->ek_path, reqp);
 932	cache_put(&ek->h, nn->svc_expkey_cache);
 933
 934	if (IS_ERR(exp))
 935		return ERR_CAST(exp);
 936	return exp;
 937}
 938
 939__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp)
 940{
 941	struct exp_flavor_info *f;
 942	struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
 943
 944	/* legacy gss-only clients are always OK: */
 945	if (exp->ex_client == rqstp->rq_gssclient)
 946		return 0;
 947	/* ip-address based client; check sec= export option: */
 948	for (f = exp->ex_flavors; f < end; f++) {
 949		if (f->pseudoflavor == rqstp->rq_cred.cr_flavor)
 950			return 0;
 951	}
 952	/* defaults in absence of sec= options: */
 953	if (exp->ex_nflavors == 0) {
 954		if (rqstp->rq_cred.cr_flavor == RPC_AUTH_NULL ||
 955		    rqstp->rq_cred.cr_flavor == RPC_AUTH_UNIX)
 956			return 0;
 957	}
 958
 959	/* If the compound op contains a spo_must_allowed op,
 960	 * it will be sent with integrity/protection which
 961	 * will have to be expressly allowed on mounts that
 962	 * don't support it
 963	 */
 964
 965	if (nfsd4_spo_must_allow(rqstp))
 966		return 0;
 967
 968	return nfserr_wrongsec;
 969}
 970
 971/*
 972 * Uses rq_client and rq_gssclient to find an export; uses rq_client (an
 973 * auth_unix client) if it's available and has secinfo information;
 974 * otherwise, will try to use rq_gssclient.
 975 *
 976 * Called from functions that handle requests; functions that do work on
 977 * behalf of mountd are passed a single client name to use, and should
 978 * use exp_get_by_name() or exp_find().
 979 */
 980struct svc_export *
 981rqst_exp_get_by_name(struct svc_rqst *rqstp, struct path *path)
 982{
 983	struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
 984	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 985	struct cache_detail *cd = nn->svc_export_cache;
 986
 987	if (rqstp->rq_client == NULL)
 988		goto gss;
 989
 990	/* First try the auth_unix client: */
 991	exp = exp_get_by_name(cd, rqstp->rq_client, path, &rqstp->rq_chandle);
 992	if (PTR_ERR(exp) == -ENOENT)
 993		goto gss;
 994	if (IS_ERR(exp))
 995		return exp;
 996	/* If it has secinfo, assume there are no gss/... clients */
 997	if (exp->ex_nflavors > 0)
 998		return exp;
 999gss:
1000	/* Otherwise, try falling back on gss client */
1001	if (rqstp->rq_gssclient == NULL)
1002		return exp;
1003	gssexp = exp_get_by_name(cd, rqstp->rq_gssclient, path, &rqstp->rq_chandle);
1004	if (PTR_ERR(gssexp) == -ENOENT)
1005		return exp;
1006	if (!IS_ERR(exp))
1007		exp_put(exp);
1008	return gssexp;
1009}
1010
1011struct svc_export *
1012rqst_exp_find(struct svc_rqst *rqstp, int fsid_type, u32 *fsidv)
1013{
1014	struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
1015	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1016	struct cache_detail *cd = nn->svc_export_cache;
1017
1018	if (rqstp->rq_client == NULL)
1019		goto gss;
1020
1021	/* First try the auth_unix client: */
1022	exp = exp_find(cd, rqstp->rq_client, fsid_type,
1023		       fsidv, &rqstp->rq_chandle);
1024	if (PTR_ERR(exp) == -ENOENT)
1025		goto gss;
1026	if (IS_ERR(exp))
1027		return exp;
1028	/* If it has secinfo, assume there are no gss/... clients */
1029	if (exp->ex_nflavors > 0)
1030		return exp;
1031gss:
1032	/* Otherwise, try falling back on gss client */
1033	if (rqstp->rq_gssclient == NULL)
1034		return exp;
1035	gssexp = exp_find(cd, rqstp->rq_gssclient, fsid_type, fsidv,
1036						&rqstp->rq_chandle);
1037	if (PTR_ERR(gssexp) == -ENOENT)
1038		return exp;
1039	if (!IS_ERR(exp))
1040		exp_put(exp);
1041	return gssexp;
1042}
1043
1044struct svc_export *
1045rqst_exp_parent(struct svc_rqst *rqstp, struct path *path)
1046{
1047	struct dentry *saved = dget(path->dentry);
1048	struct svc_export *exp = rqst_exp_get_by_name(rqstp, path);
1049
1050	while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
1051		struct dentry *parent = dget_parent(path->dentry);
1052		dput(path->dentry);
1053		path->dentry = parent;
1054		exp = rqst_exp_get_by_name(rqstp, path);
1055	}
1056	dput(path->dentry);
1057	path->dentry = saved;
1058	return exp;
1059}
1060
1061struct svc_export *rqst_find_fsidzero_export(struct svc_rqst *rqstp)
1062{
1063	u32 fsidv[2];
1064
1065	mk_fsid(FSID_NUM, fsidv, 0, 0, 0, NULL);
1066
1067	return rqst_exp_find(rqstp, FSID_NUM, fsidv);
1068}
1069
1070/*
1071 * Called when we need the filehandle for the root of the pseudofs,
1072 * for a given NFSv4 client.   The root is defined to be the
1073 * export point with fsid==0
1074 */
1075__be32
1076exp_pseudoroot(struct svc_rqst *rqstp, struct svc_fh *fhp)
1077{
1078	struct svc_export *exp;
1079	__be32 rv;
1080
1081	exp = rqst_find_fsidzero_export(rqstp);
1082	if (IS_ERR(exp))
1083		return nfserrno(PTR_ERR(exp));
1084	rv = fh_compose(fhp, exp, exp->ex_path.dentry, NULL);
1085	exp_put(exp);
1086	return rv;
1087}
1088
1089static struct flags {
1090	int flag;
1091	char *name[2];
1092} expflags[] = {
1093	{ NFSEXP_READONLY, {"ro", "rw"}},
1094	{ NFSEXP_INSECURE_PORT, {"insecure", ""}},
1095	{ NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
1096	{ NFSEXP_ALLSQUASH, {"all_squash", ""}},
1097	{ NFSEXP_ASYNC, {"async", "sync"}},
1098	{ NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
1099	{ NFSEXP_NOREADDIRPLUS, {"nordirplus", ""}},
1100	{ NFSEXP_NOHIDE, {"nohide", ""}},
1101	{ NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
1102	{ NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
1103	{ NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
1104	{ NFSEXP_V4ROOT, {"v4root", ""}},
1105	{ NFSEXP_PNFS, {"pnfs", ""}},
1106	{ NFSEXP_SECURITY_LABEL, {"security_label", ""}},
1107	{ 0, {"", ""}}
1108};
1109
1110static void show_expflags(struct seq_file *m, int flags, int mask)
1111{
1112	struct flags *flg;
1113	int state, first = 0;
1114
1115	for (flg = expflags; flg->flag; flg++) {
1116		if (flg->flag & ~mask)
1117			continue;
1118		state = (flg->flag & flags) ? 0 : 1;
1119		if (*flg->name[state])
1120			seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
1121	}
1122}
1123
1124static void show_secinfo_flags(struct seq_file *m, int flags)
1125{
1126	seq_printf(m, ",");
1127	show_expflags(m, flags, NFSEXP_SECINFO_FLAGS);
1128}
1129
1130static bool secinfo_flags_equal(int f, int g)
1131{
1132	f &= NFSEXP_SECINFO_FLAGS;
1133	g &= NFSEXP_SECINFO_FLAGS;
1134	return f == g;
1135}
1136
1137static int show_secinfo_run(struct seq_file *m, struct exp_flavor_info **fp, struct exp_flavor_info *end)
1138{
1139	int flags;
1140
1141	flags = (*fp)->flags;
1142	seq_printf(m, ",sec=%d", (*fp)->pseudoflavor);
1143	(*fp)++;
1144	while (*fp != end && secinfo_flags_equal(flags, (*fp)->flags)) {
1145		seq_printf(m, ":%d", (*fp)->pseudoflavor);
1146		(*fp)++;
1147	}
1148	return flags;
1149}
1150
1151static void show_secinfo(struct seq_file *m, struct svc_export *exp)
1152{
1153	struct exp_flavor_info *f;
1154	struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
1155	int flags;
1156
1157	if (exp->ex_nflavors == 0)
1158		return;
1159	f = exp->ex_flavors;
1160	flags = show_secinfo_run(m, &f, end);
1161	if (!secinfo_flags_equal(flags, exp->ex_flags))
1162		show_secinfo_flags(m, flags);
1163	while (f != end) {
1164		flags = show_secinfo_run(m, &f, end);
1165		show_secinfo_flags(m, flags);
1166	}
1167}
1168
1169static void exp_flags(struct seq_file *m, int flag, int fsid,
1170		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fsloc)
1171{
1172	show_expflags(m, flag, NFSEXP_ALLFLAGS);
1173	if (flag & NFSEXP_FSID)
1174		seq_printf(m, ",fsid=%d", fsid);
1175	if (!uid_eq(anonu, make_kuid(&init_user_ns, (uid_t)-2)) &&
1176	    !uid_eq(anonu, make_kuid(&init_user_ns, 0x10000-2)))
1177		seq_printf(m, ",anonuid=%u", from_kuid(&init_user_ns, anonu));
1178	if (!gid_eq(anong, make_kgid(&init_user_ns, (gid_t)-2)) &&
1179	    !gid_eq(anong, make_kgid(&init_user_ns, 0x10000-2)))
1180		seq_printf(m, ",anongid=%u", from_kgid(&init_user_ns, anong));
1181	if (fsloc && fsloc->locations_count > 0) {
1182		char *loctype = (fsloc->migrated) ? "refer" : "replicas";
1183		int i;
1184
1185		seq_printf(m, ",%s=", loctype);
1186		seq_escape(m, fsloc->locations[0].path, ",;@ \t\n\\");
1187		seq_putc(m, '@');
1188		seq_escape(m, fsloc->locations[0].hosts, ",;@ \t\n\\");
1189		for (i = 1; i < fsloc->locations_count; i++) {
1190			seq_putc(m, ';');
1191			seq_escape(m, fsloc->locations[i].path, ",;@ \t\n\\");
1192			seq_putc(m, '@');
1193			seq_escape(m, fsloc->locations[i].hosts, ",;@ \t\n\\");
1194		}
1195	}
1196}
1197
1198static int e_show(struct seq_file *m, void *p)
1199{
1200	struct cache_head *cp = p;
1201	struct svc_export *exp = container_of(cp, struct svc_export, h);
1202	struct cache_detail *cd = m->private;
1203
1204	if (p == SEQ_START_TOKEN) {
1205		seq_puts(m, "# Version 1.1\n");
1206		seq_puts(m, "# Path Client(Flags) # IPs\n");
1207		return 0;
1208	}
1209
1210	exp_get(exp);
1211	if (cache_check(cd, &exp->h, NULL))
1212		return 0;
1213	exp_put(exp);
1214	return svc_export_show(m, cd, cp);
1215}
1216
1217const struct seq_operations nfs_exports_op = {
1218	.start	= cache_seq_start,
1219	.next	= cache_seq_next,
1220	.stop	= cache_seq_stop,
1221	.show	= e_show,
1222};
1223
1224/*
1225 * Initialize the exports module.
1226 */
1227int
1228nfsd_export_init(struct net *net)
1229{
1230	int rv;
1231	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1232
1233	dprintk("nfsd: initializing export module (net: %x).\n", net->ns.inum);
1234
1235	nn->svc_export_cache = cache_create_net(&svc_export_cache_template, net);
1236	if (IS_ERR(nn->svc_export_cache))
1237		return PTR_ERR(nn->svc_export_cache);
1238	rv = cache_register_net(nn->svc_export_cache, net);
1239	if (rv)
1240		goto destroy_export_cache;
1241
1242	nn->svc_expkey_cache = cache_create_net(&svc_expkey_cache_template, net);
1243	if (IS_ERR(nn->svc_expkey_cache)) {
1244		rv = PTR_ERR(nn->svc_expkey_cache);
1245		goto unregister_export_cache;
1246	}
1247	rv = cache_register_net(nn->svc_expkey_cache, net);
1248	if (rv)
1249		goto destroy_expkey_cache;
1250	return 0;
1251
1252destroy_expkey_cache:
1253	cache_destroy_net(nn->svc_expkey_cache, net);
1254unregister_export_cache:
1255	cache_unregister_net(nn->svc_export_cache, net);
1256destroy_export_cache:
1257	cache_destroy_net(nn->svc_export_cache, net);
1258	return rv;
1259}
1260
1261/*
1262 * Flush exports table - called when last nfsd thread is killed
1263 */
1264void
1265nfsd_export_flush(struct net *net)
1266{
1267	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1268
1269	cache_purge(nn->svc_expkey_cache);
1270	cache_purge(nn->svc_export_cache);
1271}
1272
1273/*
1274 * Shutdown the exports module.
1275 */
1276void
1277nfsd_export_shutdown(struct net *net)
1278{
1279	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1280
1281	dprintk("nfsd: shutting down export module (net: %x).\n", net->ns.inum);
1282
1283	cache_unregister_net(nn->svc_expkey_cache, net);
1284	cache_unregister_net(nn->svc_export_cache, net);
1285	cache_destroy_net(nn->svc_expkey_cache, net);
1286	cache_destroy_net(nn->svc_export_cache, net);
1287	svcauth_unix_purge(net);
1288
1289	dprintk("nfsd: export shutdown complete (net: %x).\n", net->ns.inum);
1290}