fs/nfsd/export.c

   1 #define MSNFS   /* HACK HACK */
   2 /*
   3  * linux/fs/nfsd/export.c
   4  *
   5  * NFS exporting and validation.
   6  *
   7  * We maintain a list of clients, each of which has a list of
   8  * exports. To export an fs to a given client, you first have
   9  * to create the client entry with NFSCTL_ADDCLIENT, which
  10  * creates a client control block and adds it to the hash
  11  * table. Then, you call NFSCTL_EXPORT for each fs.
  12  *
  13  *
  14  * Copyright (C) 1995, 1996 Olaf Kirch, <okir@monad.swb.de>
  15  */
  16
  17 #include <linux/unistd.h>
  18 #include <linux/slab.h>
  19 #include <linux/sched.h>
  20 #include <linux/stat.h>
  21 #include <linux/in.h>
  22 #include <linux/seq_file.h>
  23 #include <linux/syscalls.h>
  24 #include <linux/rwsem.h>
  25 #include <linux/dcache.h>
  26 #include <linux/namei.h>
  27 #include <linux/mount.h>
  28 #include <linux/hash.h>
  29
  30 #include <linux/sunrpc/svc.h>
  31 #include <linux/nfsd/nfsd.h>
  32 #include <linux/nfsd/nfsfh.h>
  33 #include <linux/nfsd/syscall.h>
  34 #include <linux/lockd/bind.h>
  35
  36 #define NFSDDBG_FACILITY        NFSDDBG_EXPORT
  37 #define NFSD_PARANOIA 1
  38
  39 typedef struct auth_domain      svc_client;
  40 typedef struct svc_export       svc_export;
  41
  42 static void             exp_do_unexport(svc_export *unexp);
  43 static int              exp_verify_string(char *cp, int max);
  44
  45 /*
  46  * We have two caches.
  47  * One maps client+vfsmnt+dentry to export options - the export map
  48  * The other maps client+filehandle-fragment to export options. - the expkey map
  49  *
  50  * The export options are actually stored in the first map, and the
  51  * second map contains a reference to the entry in the first map.
  52  */
  53
  54 #define EXPKEY_HASHBITS         8
  55 #define EXPKEY_HASHMAX          (1 << EXPKEY_HASHBITS)
  56 #define EXPKEY_HASHMASK         (EXPKEY_HASHMAX -1)
  57 static struct cache_head *expkey_table[EXPKEY_HASHMAX];
  58
  59 static inline int svc_expkey_hash(struct svc_expkey *item)
  60 {
  61         int hash = item->ek_fsidtype;
  62         char * cp = (char*)item->ek_fsid;
  63         int len = key_len(item->ek_fsidtype);
  64
  65         hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
  66         hash ^= hash_ptr(item->ek_client, EXPKEY_HASHBITS);
  67         return hash & EXPKEY_HASHMASK;
  68 }
  69
  70 void expkey_put(struct cache_head *item, struct cache_detail *cd)
  71 {
  72         if (cache_put(item, cd)) {
  73                 struct svc_expkey *key = container_of(item, struct svc_expkey, h);
  74                 if (test_bit(CACHE_VALID, &item->flags) &&
  75                     !test_bit(CACHE_NEGATIVE, &item->flags))
  76                         exp_put(key->ek_export);
  77                 auth_domain_put(key->ek_client);
  78                 kfree(key);
  79         }
  80 }
  81
  82 void expkey_request(struct cache_detail *cd,
  83                     struct cache_head *h,
  84                     char **bpp, int *blen)
  85 {
  86         /* client fsidtype \xfsid */
  87         struct svc_expkey *ek = container_of(h, struct svc_expkey, h);
  88         char type[5];
  89
  90         qword_add(bpp, blen, ek->ek_client->name);
  91         snprintf(type, 5, "%d", ek->ek_fsidtype);
  92         qword_add(bpp, blen, type);
  93         qword_addhex(bpp, blen, (char*)ek->ek_fsid, key_len(ek->ek_fsidtype));
  94         (*bpp)[-1] = '\n';
  95 }
  96
  97 static struct svc_expkey *svc_expkey_lookup(struct svc_expkey *, int);
  98 int expkey_parse(struct cache_detail *cd, char *mesg, int mlen)
  99 {
 100         /* client fsidtype fsid [path] */
 101         char *buf;
 102         int len;
 103         struct auth_domain *dom = NULL;
 104         int err;
 105         int fsidtype;
 106         char *ep;
 107         struct svc_expkey key;
 108
 109         if (mesg[mlen-1] != '\n')
 110                 return -EINVAL;
 111         mesg[mlen-1] = 0;
 112
 113         buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 114         err = -ENOMEM;
 115         if (!buf) goto out;
 116
 117         err = -EINVAL;
 118         if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 119                 goto out;
 120
 121         err = -ENOENT;
 122         dom = auth_domain_find(buf);
 123         if (!dom)
 124                 goto out;
 125         dprintk("found domain %s\n", buf);
 126
 127         err = -EINVAL;
 128         if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 129                 goto out;
 130         fsidtype = simple_strtoul(buf, &ep, 10);
 131         if (*ep)
 132                 goto out;
 133         dprintk("found fsidtype %d\n", fsidtype);
 134         if (fsidtype > 2)
 135                 goto out;
 136         if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 137                 goto out;
 138         dprintk("found fsid length %d\n", len);
 139         if (len != key_len(fsidtype))
 140                 goto out;
 141
 142         /* OK, we seem to have a valid key */
 143         key.h.flags = 0;
 144         key.h.expiry_time = get_expiry(&mesg);
 145         if (key.h.expiry_time == 0)
 146                 goto out;
 147
 148         key.ek_client = dom;
 149         key.ek_fsidtype = fsidtype;
 150         memcpy(key.ek_fsid, buf, len);
 151
 152         /* now we want a pathname, or empty meaning NEGATIVE  */
 153         if ((len=qword_get(&mesg, buf, PAGE_SIZE)) < 0)
 154                 goto out;
 155         dprintk("Path seems to be <%s>\n", buf);
 156         err = 0;
 157         if (len == 0) {
 158                 struct svc_expkey *ek;
 159                 set_bit(CACHE_NEGATIVE, &key.h.flags);
 160                 ek = svc_expkey_lookup(&key, 1);
 161                 if (ek)
 162                         expkey_put(&ek->h, &svc_expkey_cache);
 163         } else {
 164                 struct nameidata nd;
 165                 struct svc_expkey *ek;
 166                 struct svc_export *exp;
 167                 err = path_lookup(buf, 0, &nd);
 168                 if (err)
 169                         goto out;
 170
 171                 dprintk("Found the path %s\n", buf);
 172                 exp = exp_get_by_name(dom, nd.mnt, nd.dentry, NULL);
 173
 174                 err = -ENOENT;
 175                 if (!exp)
 176                         goto out_nd;
 177                 key.ek_export = exp;
 178                 dprintk("And found export\n");
 179
 180                 ek = svc_expkey_lookup(&key, 1);
 181                 if (ek)
 182                         expkey_put(&ek->h, &svc_expkey_cache);
 183                 exp_put(exp);
 184                 err = 0;
 185         out_nd:
 186                 path_release(&nd);
 187         }
 188         cache_flush();
 189  out:
 190         if (dom)
 191                 auth_domain_put(dom);
 192         if (buf)
 193                 kfree(buf);
 194         return err;
 195 }
 196
 197 static int expkey_show(struct seq_file *m,
 198                        struct cache_detail *cd,
 199                        struct cache_head *h)
 200 {
 201         struct svc_expkey *ek ;
 202
 203         if (h ==NULL) {
 204                 seq_puts(m, "#domain fsidtype fsid [path]\n");
 205                 return 0;
 206         }
 207         ek = container_of(h, struct svc_expkey, h);
 208         seq_printf(m, "%s %d 0x%08x", ek->ek_client->name,
 209                    ek->ek_fsidtype, ek->ek_fsid[0]);
 210         if (ek->ek_fsidtype != 1)
 211                 seq_printf(m, "%08x", ek->ek_fsid[1]);
 212         if (ek->ek_fsidtype == 2)
 213                 seq_printf(m, "%08x", ek->ek_fsid[2]);
 214         if (test_bit(CACHE_VALID, &h->flags) &&
 215             !test_bit(CACHE_NEGATIVE, &h->flags)) {
 216                 seq_printf(m, " ");
 217                 seq_path(m, ek->ek_export->ex_mnt, ek->ek_export->ex_dentry, "\\ \t\n");
 218         }
 219         seq_printf(m, "\n");
 220         return 0;
 221 }
 222
 223 struct cache_detail svc_expkey_cache = {
 224         .hash_size      = EXPKEY_HASHMAX,
 225         .hash_table     = expkey_table,
 226         .name           = "nfsd.fh",
 227         .cache_put      = expkey_put,
 228         .cache_request  = expkey_request,
 229         .cache_parse    = expkey_parse,
 230         .cache_show     = expkey_show,
 231 };
 232
 233 static inline int svc_expkey_match (struct svc_expkey *a, struct svc_expkey *b)
 234 {
 235         if (a->ek_fsidtype != b->ek_fsidtype ||
 236             a->ek_client != b->ek_client ||
 237             memcmp(a->ek_fsid, b->ek_fsid, key_len(a->ek_fsidtype)) != 0)
 238                 return 0;
 239         return 1;
 240 }
 241
 242 static inline void svc_expkey_init(struct svc_expkey *new, struct svc_expkey *item)
 243 {
 244         cache_get(&item->ek_client->h);
 245         new->ek_client = item->ek_client;
 246         new->ek_fsidtype = item->ek_fsidtype;
 247         new->ek_fsid[0] = item->ek_fsid[0];
 248         new->ek_fsid[1] = item->ek_fsid[1];
 249         new->ek_fsid[2] = item->ek_fsid[2];
 250 }
 251
 252 static inline void svc_expkey_update(struct svc_expkey *new, struct svc_expkey *item)
 253 {
 254         cache_get(&item->ek_export->h);
 255         new->ek_export = item->ek_export;
 256 }
 257
 258 static DefineSimpleCacheLookup(svc_expkey,0) /* no inplace updates */
 259
 260 #define EXPORT_HASHBITS         8
 261 #define EXPORT_HASHMAX          (1<< EXPORT_HASHBITS)
 262 #define EXPORT_HASHMASK         (EXPORT_HASHMAX -1)
 263
 264 static struct cache_head *export_table[EXPORT_HASHMAX];
 265
 266 static inline int svc_export_hash(struct svc_export *item)
 267 {
 268         int rv;
 269
 270         rv = hash_ptr(item->ex_client, EXPORT_HASHBITS);
 271         rv ^= hash_ptr(item->ex_dentry, EXPORT_HASHBITS);
 272         rv ^= hash_ptr(item->ex_mnt, EXPORT_HASHBITS);
 273         return rv;
 274 }
 275
 276 void svc_export_put(struct cache_head *item, struct cache_detail *cd)
 277 {
 278         if (cache_put(item, cd)) {
 279                 struct svc_export *exp = container_of(item, struct svc_export, h);
 280                 dput(exp->ex_dentry);
 281                 mntput(exp->ex_mnt);
 282                 auth_domain_put(exp->ex_client);
 283                 kfree(exp);
 284         }
 285 }
 286
 287 void svc_export_request(struct cache_detail *cd,
 288                         struct cache_head *h,
 289                         char **bpp, int *blen)
 290 {
 291         /*  client path */
 292         struct svc_export *exp = container_of(h, struct svc_export, h);
 293         char *pth;
 294
 295         qword_add(bpp, blen, exp->ex_client->name);
 296         pth = d_path(exp->ex_dentry, exp->ex_mnt, *bpp, *blen);
 297         if (IS_ERR(pth)) {
 298                 /* is this correct? */
 299                 (*bpp)[0] = '\n';
 300                 return;
 301         }
 302         qword_add(bpp, blen, pth);
 303         (*bpp)[-1] = '\n';
 304 }
 305
 306 static struct svc_export *svc_export_lookup(struct svc_export *, int);
 307
 308 extern struct dentry *
 309 find_exported_dentry(struct super_block *sb, void *obj, void *parent,
 310                      int (*acceptable)(void *context, struct dentry *de),
 311                      void *context);
 312
 313 static int check_export(struct inode *inode, int flags)
 314 {
 315
 316         /* We currently export only dirs and regular files.
 317          * This is what umountd does.
 318          */
 319         if (!S_ISDIR(inode->i_mode) &&
 320             !S_ISREG(inode->i_mode))
 321                 return -ENOTDIR;
 322
 323         /* There are two requirements on a filesystem to be exportable.
 324          * 1:  We must be able to identify the filesystem from a number.
 325          *       either a device number (so FS_REQUIRES_DEV needed)
 326          *       or an FSID number (so NFSEXP_FSID needed).
 327          * 2:  We must be able to find an inode from a filehandle.
 328          *       This means that s_export_op must be set.
 329          */
 330         if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) &&
 331             !(flags & NFSEXP_FSID)) {
 332                 dprintk("exp_export: export of non-dev fs without fsid");
 333                 return -EINVAL;
 334         }
 335         if (!inode->i_sb->s_export_op) {
 336                 dprintk("exp_export: export of invalid fs type.\n");
 337                 return -EINVAL;
 338         }
 339
 340         /* Ok, we can export it */;
 341         if (!inode->i_sb->s_export_op->find_exported_dentry)
 342                 inode->i_sb->s_export_op->find_exported_dentry =
 343                         find_exported_dentry;
 344         return 0;
 345
 346 }
 347
 348 int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
 349 {
 350         /* client path expiry [flags anonuid anongid fsid] */
 351         char *buf;
 352         int len;
 353         int err;
 354         struct auth_domain *dom = NULL;
 355         struct nameidata nd;
 356         struct svc_export exp, *expp;
 357         int an_int;
 358
 359         nd.dentry = NULL;
 360
 361         if (mesg[mlen-1] != '\n')
 362                 return -EINVAL;
 363         mesg[mlen-1] = 0;
 364
 365         buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 366         err = -ENOMEM;
 367         if (!buf) goto out;
 368
 369         /* client */
 370         len = qword_get(&mesg, buf, PAGE_SIZE);
 371         err = -EINVAL;
 372         if (len <= 0) goto out;
 373
 374         err = -ENOENT;
 375         dom = auth_domain_find(buf);
 376         if (!dom)
 377                 goto out;
 378
 379         /* path */
 380         err = -EINVAL;
 381         if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 382                 goto out;
 383         err = path_lookup(buf, 0, &nd);
 384         if (err) goto out;
 385
 386         exp.h.flags = 0;
 387         exp.ex_client = dom;
 388         exp.ex_mnt = nd.mnt;
 389         exp.ex_dentry = nd.dentry;
 390
 391         /* expiry */
 392         err = -EINVAL;
 393         exp.h.expiry_time = get_expiry(&mesg);
 394         if (exp.h.expiry_time == 0)
 395                 goto out;
 396
 397         /* flags */
 398         err = get_int(&mesg, &an_int);
 399         if (err == -ENOENT)
 400                 set_bit(CACHE_NEGATIVE, &exp.h.flags);
 401         else {
 402                 if (err || an_int < 0) goto out;
 403                 exp.ex_flags= an_int;
 404
 405                 /* anon uid */
 406                 err = get_int(&mesg, &an_int);
 407                 if (err) goto out;
 408                 exp.ex_anon_uid= an_int;
 409
 410                 /* anon gid */
 411                 err = get_int(&mesg, &an_int);
 412                 if (err) goto out;
 413                 exp.ex_anon_gid= an_int;
 414
 415                 /* fsid */
 416                 err = get_int(&mesg, &an_int);
 417                 if (err) goto out;
 418                 exp.ex_fsid = an_int;
 419
 420                 err = check_export(nd.dentry->d_inode, exp.ex_flags);
 421                 if (err) goto out;
 422         }
 423
 424         expp = svc_export_lookup(&exp, 1);
 425         if (expp)
 426                 exp_put(expp);
 427         err = 0;
 428         cache_flush();
 429  out:
 430         if (nd.dentry)
 431                 path_release(&nd);
 432         if (dom)
 433                 auth_domain_put(dom);
 434         if (buf)
 435                 kfree(buf);
 436         return err;
 437 }
 438
 439 static void exp_flags(struct seq_file *m, int flag, int fsid, uid_t anonu, uid_t anong);
 440
 441 static int svc_export_show(struct seq_file *m,
 442                            struct cache_detail *cd,
 443                            struct cache_head *h)
 444 {
 445         struct svc_export *exp ;
 446
 447         if (h ==NULL) {
 448                 seq_puts(m, "#path domain(flags)\n");
 449                 return 0;
 450         }
 451         exp = container_of(h, struct svc_export, h);
 452         seq_path(m, exp->ex_mnt, exp->ex_dentry, " \t\n\\");
 453         seq_putc(m, '\t');
 454         seq_escape(m, exp->ex_client->name, " \t\n\\");
 455         seq_putc(m, '(');
 456         if (test_bit(CACHE_VALID, &h->flags) &&
 457             !test_bit(CACHE_NEGATIVE, &h->flags))
 458                 exp_flags(m, exp->ex_flags, exp->ex_fsid,
 459                           exp->ex_anon_uid, exp->ex_anon_gid);
 460         seq_puts(m, ")\n");
 461         return 0;
 462 }
 463 struct cache_detail svc_export_cache = {
 464         .hash_size      = EXPORT_HASHMAX,
 465         .hash_table     = export_table,
 466         .name           = "nfsd.export",
 467         .cache_put      = svc_export_put,
 468         .cache_request  = svc_export_request,
 469         .cache_parse    = svc_export_parse,
 470         .cache_show     = svc_export_show,
 471 };
 472
 473 static inline int svc_export_match(struct svc_export *a, struct svc_export *b)
 474 {
 475         return a->ex_client == b->ex_client &&
 476                 a->ex_dentry == b->ex_dentry &&
 477                 a->ex_mnt == b->ex_mnt;
 478 }
 479 static inline void svc_export_init(struct svc_export *new, struct svc_export *item)
 480 {
 481         cache_get(&item->ex_client->h);
 482         new->ex_client = item->ex_client;
 483         new->ex_dentry = dget(item->ex_dentry);
 484         new->ex_mnt = mntget(item->ex_mnt);
 485 }
 486
 487 static inline void svc_export_update(struct svc_export *new, struct svc_export *item)
 488 {
 489         new->ex_flags = item->ex_flags;
 490         new->ex_anon_uid = item->ex_anon_uid;
 491         new->ex_anon_gid = item->ex_anon_gid;
 492         new->ex_fsid = item->ex_fsid;
 493 }
 494
 495 static DefineSimpleCacheLookup(svc_export,1) /* allow inplace updates */
 496
 497
 498 struct svc_expkey *
 499 exp_find_key(svc_client *clp, int fsid_type, u32 *fsidv, struct cache_req *reqp)
 500 {
 501         struct svc_expkey key, *ek;
 502         int err;
 503
 504         if (!clp)
 505                 return NULL;
 506
 507         key.ek_client = clp;
 508         key.ek_fsidtype = fsid_type;
 509         memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
 510
 511         ek = svc_expkey_lookup(&key, 0);
 512         if (ek != NULL)
 513                 if ((err = cache_check(&svc_expkey_cache, &ek->h, reqp)))
 514                         ek = ERR_PTR(err);
 515         return ek;
 516 }
 517
 518 int exp_set_key(svc_client *clp, int fsid_type, u32 *fsidv,
 519                 struct svc_export *exp)
 520 {
 521         struct svc_expkey key, *ek;
 522
 523         key.ek_client = clp;
 524         key.ek_fsidtype = fsid_type;
 525         memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
 526         key.ek_export = exp;
 527         key.h.expiry_time = NEVER;
 528         key.h.flags = 0;
 529
 530         ek = svc_expkey_lookup(&key, 1);
 531         if (ek) {
 532                 expkey_put(&ek->h, &svc_expkey_cache);
 533                 return 0;
 534         }
 535         return -ENOMEM;
 536 }
 537
 538 /*
 539  * Find the client's export entry matching xdev/xino.
 540  */
 541 static inline struct svc_expkey *
 542 exp_get_key(svc_client *clp, dev_t dev, ino_t ino)
 543 {
 544         u32 fsidv[3];
 545
 546         if (old_valid_dev(dev)) {
 547                 mk_fsid_v0(fsidv, dev, ino);
 548                 return exp_find_key(clp, 0, fsidv, NULL);
 549         }
 550         mk_fsid_v3(fsidv, dev, ino);
 551         return exp_find_key(clp, 3, fsidv, NULL);
 552 }
 553
 554 /*
 555  * Find the client's export entry matching fsid
 556  */
 557 static inline struct svc_expkey *
 558 exp_get_fsid_key(svc_client *clp, int fsid)
 559 {
 560         u32 fsidv[2];
 561
 562         mk_fsid_v1(fsidv, fsid);
 563
 564         return exp_find_key(clp, 1, fsidv, NULL);
 565 }
 566
 567 svc_export *
 568 exp_get_by_name(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry,
 569                 struct cache_req *reqp)
 570 {
 571         struct svc_export *exp, key;
 572
 573         if (!clp)
 574                 return NULL;
 575
 576         key.ex_client = clp;
 577         key.ex_mnt = mnt;
 578         key.ex_dentry = dentry;
 579
 580         exp = svc_export_lookup(&key, 0);
 581         if (exp != NULL)
 582                 switch (cache_check(&svc_export_cache, &exp->h, reqp)) {
 583                 case 0: break;
 584                 case -EAGAIN:
 585                         exp = ERR_PTR(-EAGAIN);
 586                         break;
 587                 default:
 588                         exp = NULL;
 589                 }
 590
 591         return exp;
 592 }
 593
 594 /*
 595  * Find the export entry for a given dentry.
 596  */
 597 struct svc_export *
 598 exp_parent(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry,
 599            struct cache_req *reqp)
 600 {
 601         svc_export *exp;
 602
 603         dget(dentry);
 604         exp = exp_get_by_name(clp, mnt, dentry, reqp);
 605
 606         while (exp == NULL && !IS_ROOT(dentry)) {
 607                 struct dentry *parent;
 608
 609                 parent = dget_parent(dentry);
 610                 dput(dentry);
 611                 dentry = parent;
 612                 exp = exp_get_by_name(clp, mnt, dentry, reqp);
 613         }
 614         dput(dentry);
 615         return exp;
 616 }
 617
 618 /*
 619  * Hashtable locking. Write locks are placed only by user processes
 620  * wanting to modify export information.
 621  * Write locking only done in this file.  Read locking
 622  * needed externally.
 623  */
 624
 625 static DECLARE_RWSEM(hash_sem);
 626
 627 void
 628 exp_readlock(void)
 629 {
 630         down_read(&hash_sem);
 631 }
 632
 633 static inline void
 634 exp_writelock(void)
 635 {
 636         down_write(&hash_sem);
 637 }
 638
 639 void
 640 exp_readunlock(void)
 641 {
 642         up_read(&hash_sem);
 643 }
 644
 645 static inline void
 646 exp_writeunlock(void)
 647 {
 648         up_write(&hash_sem);
 649 }
 650
 651 static void exp_fsid_unhash(struct svc_export *exp)
 652 {
 653         struct svc_expkey *ek;
 654
 655         if ((exp->ex_flags & NFSEXP_FSID) == 0)
 656                 return;
 657
 658         ek = exp_get_fsid_key(exp->ex_client, exp->ex_fsid);
 659         if (ek && !IS_ERR(ek)) {
 660                 ek->h.expiry_time = get_seconds()-1;
 661                 expkey_put(&ek->h, &svc_expkey_cache);
 662         }
 663         svc_expkey_cache.nextcheck = get_seconds();
 664 }
 665
 666 static int exp_fsid_hash(svc_client *clp, struct svc_export *exp)
 667 {
 668         u32 fsid[2];
 669
 670         if ((exp->ex_flags & NFSEXP_FSID) == 0)
 671                 return 0;
 672
 673         mk_fsid_v1(fsid, exp->ex_fsid);
 674         return exp_set_key(clp, 1, fsid, exp);
 675 }
 676
 677 static int exp_hash(struct auth_domain *clp, struct svc_export *exp)
 678 {
 679         u32 fsid[2];
 680         struct inode *inode = exp->ex_dentry->d_inode;
 681         dev_t dev = inode->i_sb->s_dev;
 682
 683         if (old_valid_dev(dev)) {
 684                 mk_fsid_v0(fsid, dev, inode->i_ino);
 685                 return exp_set_key(clp, 0, fsid, exp);
 686         }
 687         mk_fsid_v3(fsid, dev, inode->i_ino);
 688         return exp_set_key(clp, 3, fsid, exp);
 689 }
 690
 691 static void exp_unhash(struct svc_export *exp)
 692 {
 693         struct svc_expkey *ek;
 694         struct inode *inode = exp->ex_dentry->d_inode;
 695
 696         ek = exp_get_key(exp->ex_client, inode->i_sb->s_dev, inode->i_ino);
 697         if (ek && !IS_ERR(ek)) {
 698                 ek->h.expiry_time = get_seconds()-1;
 699                 expkey_put(&ek->h, &svc_expkey_cache);
 700         }
 701         svc_expkey_cache.nextcheck = get_seconds();
 702 }
 703
 704 /*
 705  * Export a file system.
 706  */
 707 int
 708 exp_export(struct nfsctl_export *nxp)
 709 {
 710         svc_client      *clp;
 711         struct svc_export       *exp = NULL;
 712         struct svc_export       new;
 713         struct svc_expkey       *fsid_key = NULL;
 714         struct nameidata nd;
 715         int             err;
 716
 717         /* Consistency check */
 718         err = -EINVAL;
 719         if (!exp_verify_string(nxp->ex_path, NFS_MAXPATHLEN) ||
 720             !exp_verify_string(nxp->ex_client, NFSCLNT_IDMAX))
 721                 goto out;
 722
 723         dprintk("exp_export called for %s:%s (%x/%ld fl %x).\n",
 724                         nxp->ex_client, nxp->ex_path,
 725                         (unsigned)nxp->ex_dev, (long)nxp->ex_ino,
 726                         nxp->ex_flags);
 727
 728         /* Try to lock the export table for update */
 729         exp_writelock();
 730
 731         /* Look up client info */
 732         if (!(clp = auth_domain_find(nxp->ex_client)))
 733                 goto out_unlock;
 734
 735
 736         /* Look up the dentry */
 737         err = path_lookup(nxp->ex_path, 0, &nd);
 738         if (err)
 739                 goto out_unlock;
 740         err = -EINVAL;
 741
 742         exp = exp_get_by_name(clp, nd.mnt, nd.dentry, NULL);
 743
 744         /* must make sure there won't be an ex_fsid clash */
 745         if ((nxp->ex_flags & NFSEXP_FSID) &&
 746             (fsid_key = exp_get_fsid_key(clp, nxp->ex_dev)) &&
 747             !IS_ERR(fsid_key) &&
 748             fsid_key->ek_export &&
 749             fsid_key->ek_export != exp)
 750                 goto finish;
 751
 752         if (exp) {
 753                 /* just a flags/id/fsid update */
 754
 755                 exp_fsid_unhash(exp);
 756                 exp->ex_flags    = nxp->ex_flags;
 757                 exp->ex_anon_uid = nxp->ex_anon_uid;
 758                 exp->ex_anon_gid = nxp->ex_anon_gid;
 759                 exp->ex_fsid     = nxp->ex_dev;
 760
 761                 err = exp_fsid_hash(clp, exp);
 762                 goto finish;
 763         }
 764
 765         err = check_export(nd.dentry->d_inode, nxp->ex_flags);
 766         if (err) goto finish;
 767
 768         err = -ENOMEM;
 769
 770         dprintk("nfsd: creating export entry %p for client %p\n", exp, clp);
 771
 772         new.h.expiry_time = NEVER;
 773         new.h.flags = 0;
 774         new.ex_client = clp;
 775         new.ex_mnt = nd.mnt;
 776         new.ex_dentry = nd.dentry;
 777         new.ex_flags = nxp->ex_flags;
 778         new.ex_anon_uid = nxp->ex_anon_uid;
 779         new.ex_anon_gid = nxp->ex_anon_gid;
 780         new.ex_fsid = nxp->ex_dev;
 781
 782         exp = svc_export_lookup(&new, 1);
 783
 784         if (exp == NULL)
 785                 goto finish;
 786
 787         err = 0;
 788
 789         if (exp_hash(clp, exp) ||
 790             exp_fsid_hash(clp, exp)) {
 791                 /* failed to create at least one index */
 792                 exp_do_unexport(exp);
 793                 cache_flush();
 794                 err = -ENOMEM;
 795         }
 796
 797 finish:
 798         if (exp)
 799                 exp_put(exp);
 800         if (fsid_key && !IS_ERR(fsid_key))
 801                 expkey_put(&fsid_key->h, &svc_expkey_cache);
 802         if (clp)
 803                 auth_domain_put(clp);
 804         path_release(&nd);
 805 out_unlock:
 806         exp_writeunlock();
 807 out:
 808         return err;
 809 }
 810
 811 /*
 812  * Unexport a file system. The export entry has already
 813  * been removed from the client's list of exported fs's.
 814  */
 815 static void
 816 exp_do_unexport(svc_export *unexp)
 817 {
 818         unexp->h.expiry_time = get_seconds()-1;
 819         svc_export_cache.nextcheck = get_seconds();
 820         exp_unhash(unexp);
 821         exp_fsid_unhash(unexp);
 822 }
 823
 824
 825 /*
 826  * unexport syscall.
 827  */
 828 int
 829 exp_unexport(struct nfsctl_export *nxp)
 830 {
 831         struct auth_domain *dom;
 832         svc_export *exp;
 833         struct nameidata nd;
 834         int             err;
 835
 836         /* Consistency check */
 837         if (!exp_verify_string(nxp->ex_path, NFS_MAXPATHLEN) ||
 838             !exp_verify_string(nxp->ex_client, NFSCLNT_IDMAX))
 839                 return -EINVAL;
 840
 841         exp_writelock();
 842
 843         err = -EINVAL;
 844         dom = auth_domain_find(nxp->ex_client);
 845         if (!dom) {
 846                 dprintk("nfsd: unexport couldn't find %s\n", nxp->ex_client);
 847                 goto out_unlock;
 848         }
 849
 850         err = path_lookup(nxp->ex_path, 0, &nd);
 851         if (err)
 852                 goto out_domain;
 853
 854         err = -EINVAL;
 855         exp = exp_get_by_name(dom, nd.mnt, nd.dentry, NULL);
 856         path_release(&nd);
 857         if (!exp)
 858                 goto out_domain;
 859
 860         exp_do_unexport(exp);
 861         exp_put(exp);
 862         err = 0;
 863
 864 out_domain:
 865         auth_domain_put(dom);
 866         cache_flush();
 867 out_unlock:
 868         exp_writeunlock();
 869         return err;
 870 }
 871
 872 /*
 873  * Obtain the root fh on behalf of a client.
 874  * This could be done in user space, but I feel that it adds some safety
 875  * since its harder to fool a kernel module than a user space program.
 876  */
 877 int
 878 exp_rootfh(svc_client *clp, char *path, struct knfsd_fh *f, int maxsize)
 879 {
 880         struct svc_export       *exp;
 881         struct nameidata        nd;
 882         struct inode            *inode;
 883         struct svc_fh           fh;
 884         int                     err;
 885
 886         err = -EPERM;
 887         /* NB: we probably ought to check that it's NUL-terminated */
 888         if (path_lookup(path, 0, &nd)) {
 889                 printk("nfsd: exp_rootfh path not found %s", path);
 890                 return err;
 891         }
 892         inode = nd.dentry->d_inode;
 893
 894         dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
 895                  path, nd.dentry, clp->name,
 896                  inode->i_sb->s_id, inode->i_ino);
 897         exp = exp_parent(clp, nd.mnt, nd.dentry, NULL);
 898         if (!exp) {
 899                 dprintk("nfsd: exp_rootfh export not found.\n");
 900                 goto out;
 901         }
 902
 903         /*
 904          * fh must be initialized before calling fh_compose
 905          */
 906         fh_init(&fh, maxsize);
 907         if (fh_compose(&fh, exp, nd.dentry, NULL))
 908                 err = -EINVAL;
 909         else
 910                 err = 0;
 911         memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
 912         fh_put(&fh);
 913         exp_put(exp);
 914 out:
 915         path_release(&nd);
 916         return err;
 917 }
 918
 919 /*
 920  * Called when we need the filehandle for the root of the pseudofs,
 921  * for a given NFSv4 client.   The root is defined to be the
 922  * export point with fsid==0
 923  */
 924 int
 925 exp_pseudoroot(struct auth_domain *clp, struct svc_fh *fhp,
 926                struct cache_req *creq)
 927 {
 928         struct svc_expkey *fsid_key;
 929         int rv;
 930         u32 fsidv[2];
 931
 932         mk_fsid_v1(fsidv, 0);
 933
 934         fsid_key = exp_find_key(clp, 1, fsidv, creq);
 935         if (IS_ERR(fsid_key) && PTR_ERR(fsid_key) == -EAGAIN)
 936                 return nfserr_dropit;
 937         if (!fsid_key || IS_ERR(fsid_key))
 938                 return nfserr_perm;
 939
 940         rv = fh_compose(fhp, fsid_key->ek_export,
 941                           fsid_key->ek_export->ex_dentry, NULL);
 942         expkey_put(&fsid_key->h, &svc_expkey_cache);
 943         return rv;
 944 }
 945
 946 /* Iterator */
 947
 948 static void *e_start(struct seq_file *m, loff_t *pos)
 949 {
 950         loff_t n = *pos;
 951         unsigned hash, export;
 952         struct cache_head *ch;
 953
 954         exp_readlock();
 955         read_lock(&svc_export_cache.hash_lock);
 956         if (!n--)
 957                 return (void *)1;
 958         hash = n >> 32;
 959         export = n & ((1LL<<32) - 1);
 960
 961
 962         for (ch=export_table[hash]; ch; ch=ch->next)
 963                 if (!export--)
 964                         return ch;
 965         n &= ~((1LL<<32) - 1);
 966         do {
 967                 hash++;
 968                 n += 1LL<<32;
 969         } while(hash < EXPORT_HASHMAX && export_table[hash]==NULL);
 970         if (hash >= EXPORT_HASHMAX)
 971                 return NULL;
 972         *pos = n+1;
 973         return export_table[hash];
 974 }
 975
 976 static void *e_next(struct seq_file *m, void *p, loff_t *pos)
 977 {
 978         struct cache_head *ch = p;
 979         int hash = (*pos >> 32);
 980
 981         if (p == (void *)1)
 982                 hash = 0;
 983         else if (ch->next == NULL) {
 984                 hash++;
 985                 *pos += 1LL<<32;
 986         } else {
 987                 ++*pos;
 988                 return ch->next;
 989         }
 990         *pos &= ~((1LL<<32) - 1);
 991         while (hash < EXPORT_HASHMAX && export_table[hash] == NULL) {
 992                 hash++;
 993                 *pos += 1LL<<32;
 994         }
 995         if (hash >= EXPORT_HASHMAX)
 996                 return NULL;
 997         ++*pos;
 998         return export_table[hash];
 999 }
1000
1001 static void e_stop(struct seq_file *m, void *p)
1002 {
1003         read_unlock(&svc_export_cache.hash_lock);
1004         exp_readunlock();
1005 }
1006
1007 struct flags {
1008         int flag;
1009         char *name[2];
1010 } expflags[] = {
1011         { NFSEXP_READONLY, {"ro", "rw"}},
1012         { NFSEXP_INSECURE_PORT, {"insecure", ""}},
1013         { NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
1014         { NFSEXP_ALLSQUASH, {"all_squash", ""}},
1015         { NFSEXP_ASYNC, {"async", "sync"}},
1016         { NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
1017         { NFSEXP_NOHIDE, {"nohide", ""}},
1018         { NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
1019         { NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
1020         { NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
1021 #ifdef MSNFS
1022         { NFSEXP_MSNFS, {"msnfs", ""}},
1023 #endif
1024         { 0, {"", ""}}
1025 };
1026
1027 static void exp_flags(struct seq_file *m, int flag, int fsid, uid_t anonu, uid_t anong)
1028 {
1029         int first = 0;
1030         struct flags *flg;
1031
1032         for (flg = expflags; flg->flag; flg++) {
1033                 int state = (flg->flag & flag)?0:1;
1034                 if (*flg->name[state])
1035                         seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
1036         }
1037         if (flag & NFSEXP_FSID)
1038                 seq_printf(m, "%sfsid=%d", first++?",":"", fsid);
1039         if (anonu != (uid_t)-2 && anonu != (0x10000-2))
1040                 seq_printf(m, "%sanonuid=%d", first++?",":"", anonu);
1041         if (anong != (gid_t)-2 && anong != (0x10000-2))
1042                 seq_printf(m, "%sanongid=%d", first++?",":"", anong);
1043 }
1044
1045 static int e_show(struct seq_file *m, void *p)
1046 {
1047         struct cache_head *cp = p;
1048         struct svc_export *exp = container_of(cp, struct svc_export, h);
1049         svc_client *clp;
1050
1051         if (p == (void *)1) {
1052                 seq_puts(m, "# Version 1.1\n");
1053                 seq_puts(m, "# Path Client(Flags) # IPs\n");
1054                 return 0;
1055         }
1056
1057         clp = exp->ex_client;
1058         cache_get(&exp->h);
1059         if (cache_check(&svc_export_cache, &exp->h, NULL))
1060                 return 0;
1061         if (cache_put(&exp->h, &svc_export_cache)) BUG();
1062         return svc_export_show(m, &svc_export_cache, cp);
1063 }
1064
1065 struct seq_operations nfs_exports_op = {
1066         .start  = e_start,
1067         .next   = e_next,
1068         .stop   = e_stop,
1069         .show   = e_show,
1070 };
1071
1072 /*
1073  * Add or modify a client.
1074  * Change requests may involve the list of host addresses. The list of
1075  * exports and possibly existing uid maps are left untouched.
1076  */
1077 int
1078 exp_addclient(struct nfsctl_client *ncp)
1079 {
1080         struct auth_domain      *dom;
1081         int                     i, err;
1082
1083         /* First, consistency check. */
1084         err = -EINVAL;
1085         if (! exp_verify_string(ncp->cl_ident, NFSCLNT_IDMAX))
1086                 goto out;
1087         if (ncp->cl_naddr > NFSCLNT_ADDRMAX)
1088                 goto out;
1089
1090         /* Lock the hashtable */
1091         exp_writelock();
1092
1093         dom = unix_domain_find(ncp->cl_ident);
1094
1095         err = -ENOMEM;
1096         if (!dom)
1097                 goto out_unlock;
1098
1099         /* Insert client into hashtable. */
1100         for (i = 0; i < ncp->cl_naddr; i++)
1101                 auth_unix_add_addr(ncp->cl_addrlist[i], dom);
1102
1103         auth_unix_forget_old(dom);
1104         auth_domain_put(dom);
1105
1106         err = 0;
1107
1108 out_unlock:
1109         exp_writeunlock();
1110 out:
1111         return err;
1112 }
1113
1114 /*
1115  * Delete a client given an identifier.
1116  */
1117 int
1118 exp_delclient(struct nfsctl_client *ncp)
1119 {
1120         int             err;
1121         struct auth_domain *dom;
1122
1123         err = -EINVAL;
1124         if (!exp_verify_string(ncp->cl_ident, NFSCLNT_IDMAX))
1125                 goto out;
1126
1127         /* Lock the hashtable */
1128         exp_writelock();
1129
1130         dom = auth_domain_find(ncp->cl_ident);
1131         /* just make sure that no addresses work
1132          * and that it will expire soon
1133          */
1134         if (dom) {
1135                 err = auth_unix_forget_old(dom);
1136                 dom->h.expiry_time = get_seconds();
1137                 auth_domain_put(dom);
1138         }
1139
1140         exp_writeunlock();
1141 out:
1142         return err;
1143 }
1144
1145 /*
1146  * Verify that string is non-empty and does not exceed max length.
1147  */
1148 static int
1149 exp_verify_string(char *cp, int max)
1150 {
1151         int     i;
1152
1153         for (i = 0; i < max; i++)
1154                 if (!cp[i])
1155                         return i;
1156         cp[i] = 0;
1157         printk(KERN_NOTICE "nfsd: couldn't validate string %s\n", cp);
1158         return 0;
1159 }
1160
1161 /*
1162  * Initialize the exports module.
1163  */
1164 void
1165 nfsd_export_init(void)
1166 {
1167         dprintk("nfsd: initializing export module.\n");
1168
1169         cache_register(&svc_export_cache);
1170         cache_register(&svc_expkey_cache);
1171
1172 }
1173
1174 /*
1175  * Flush exports table - called when last nfsd thread is killed
1176  */
1177 void
1178 nfsd_export_flush(void)
1179 {
1180         exp_writelock();
1181         cache_purge(&svc_expkey_cache);
1182         cache_purge(&svc_export_cache);
1183         exp_writeunlock();
1184 }
1185
1186 /*
1187  * Shutdown the exports module.
1188  */
1189 void
1190 nfsd_export_shutdown(void)
1191 {
1192
1193         dprintk("nfsd: shutting down export module.\n");
1194
1195         exp_writelock();
1196
1197         if (cache_unregister(&svc_expkey_cache))
1198                 printk(KERN_ERR "nfsd: failed to unregister expkey cache\n");
1199         if (cache_unregister(&svc_export_cache))
1200                 printk(KERN_ERR "nfsd: failed to unregister export cache\n");
1201         svcauth_unix_purge();
1202
1203         exp_writeunlock();
1204         dprintk("nfsd: export shutdown complete.\n");
1205 }