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