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 void expkey_put(struct kref *ref)
  61 {
  62         struct svc_expkey *key = container_of(ref, struct svc_expkey, h.ref);
  63
  64         if (test_bit(CACHE_VALID, &key->h.flags) &&
  65             !test_bit(CACHE_NEGATIVE, &key->h.flags)) {
  66                 dput(key->ek_dentry);
  67                 mntput(key->ek_mnt);
  68         }
  69         auth_domain_put(key->ek_client);
  70         kfree(key);
  71 }
  72
  73 static void expkey_request(struct cache_detail *cd,
  74                            struct cache_head *h,
  75                            char **bpp, int *blen)
  76 {
  77         /* client fsidtype \xfsid */
  78         struct svc_expkey *ek = container_of(h, struct svc_expkey, h);
  79         char type[5];
  80
  81         qword_add(bpp, blen, ek->ek_client->name);
  82         snprintf(type, 5, "%d", ek->ek_fsidtype);
  83         qword_add(bpp, blen, type);
  84         qword_addhex(bpp, blen, (char*)ek->ek_fsid, key_len(ek->ek_fsidtype));
  85         (*bpp)[-1] = '\n';
  86 }
  87
  88 static struct svc_expkey *svc_expkey_update(struct svc_expkey *new, struct svc_expkey *old);
  89 static struct svc_expkey *svc_expkey_lookup(struct svc_expkey *);
  90 static struct cache_detail svc_expkey_cache;
  91
  92 static int expkey_parse(struct cache_detail *cd, char *mesg, int mlen)
  93 {
  94         /* client fsidtype fsid [path] */
  95         char *buf;
  96         int len;
  97         struct auth_domain *dom = NULL;
  98         int err;
  99         int fsidtype;
 100         char *ep;
 101         struct svc_expkey key;
 102         struct svc_expkey *ek;
 103
 104         if (mesg[mlen-1] != '\n')
 105                 return -EINVAL;
 106         mesg[mlen-1] = 0;
 107
 108         buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 109         err = -ENOMEM;
 110         if (!buf) goto out;
 111
 112         err = -EINVAL;
 113         if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 114                 goto out;
 115
 116         err = -ENOENT;
 117         dom = auth_domain_find(buf);
 118         if (!dom)
 119                 goto out;
 120         dprintk("found domain %s\n", buf);
 121
 122         err = -EINVAL;
 123         if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 124                 goto out;
 125         fsidtype = simple_strtoul(buf, &ep, 10);
 126         if (*ep)
 127                 goto out;
 128         dprintk("found fsidtype %d\n", fsidtype);
 129         if (fsidtype > 2)
 130                 goto out;
 131         if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 132                 goto out;
 133         dprintk("found fsid length %d\n", len);
 134         if (len != key_len(fsidtype))
 135                 goto out;
 136
 137         /* OK, we seem to have a valid key */
 138         key.h.flags = 0;
 139         key.h.expiry_time = get_expiry(&mesg);
 140         if (key.h.expiry_time == 0)
 141                 goto out;
 142
 143         key.ek_client = dom;
 144         key.ek_fsidtype = fsidtype;
 145         memcpy(key.ek_fsid, buf, len);
 146
 147         ek = svc_expkey_lookup(&key);
 148         err = -ENOMEM;
 149         if (!ek)
 150                 goto out;
 151
 152         /* now we want a pathname, or empty meaning NEGATIVE  */
 153         err = -EINVAL;
 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                 set_bit(CACHE_NEGATIVE, &key.h.flags);
 160                 ek = svc_expkey_update(&key, ek);
 161                 if (ek)
 162                         cache_put(&ek->h, &svc_expkey_cache);
 163                 else err = -ENOMEM;
 164         } else {
 165                 struct nameidata nd;
 166                 err = path_lookup(buf, 0, &nd);
 167                 if (err)
 168                         goto out;
 169
 170                 dprintk("Found the path %s\n", buf);
 171                 key.ek_mnt = nd.mnt;
 172                 key.ek_dentry = nd.dentry;
 173
 174                 ek = svc_expkey_update(&key, ek);
 175                 if (ek)
 176                         cache_put(&ek->h, &svc_expkey_cache);
 177                 else
 178                         err = -ENOMEM;
 179                 path_release(&nd);
 180         }
 181         cache_flush();
 182  out:
 183         if (dom)
 184                 auth_domain_put(dom);
 185         kfree(buf);
 186         return err;
 187 }
 188
 189 static int expkey_show(struct seq_file *m,
 190                        struct cache_detail *cd,
 191                        struct cache_head *h)
 192 {
 193         struct svc_expkey *ek ;
 194
 195         if (h ==NULL) {
 196                 seq_puts(m, "#domain fsidtype fsid [path]\n");
 197                 return 0;
 198         }
 199         ek = container_of(h, struct svc_expkey, h);
 200         seq_printf(m, "%s %d 0x%08x", ek->ek_client->name,
 201                    ek->ek_fsidtype, ek->ek_fsid[0]);
 202         if (ek->ek_fsidtype != 1)
 203                 seq_printf(m, "%08x", ek->ek_fsid[1]);
 204         if (ek->ek_fsidtype == 2)
 205                 seq_printf(m, "%08x", ek->ek_fsid[2]);
 206         if (test_bit(CACHE_VALID, &h->flags) &&
 207             !test_bit(CACHE_NEGATIVE, &h->flags)) {
 208                 seq_printf(m, " ");
 209                 seq_path(m, ek->ek_mnt, ek->ek_dentry, "\\ \t\n");
 210         }
 211         seq_printf(m, "\n");
 212         return 0;
 213 }
 214
 215 static inline int expkey_match (struct cache_head *a, struct cache_head *b)
 216 {
 217         struct svc_expkey *orig = container_of(a, struct svc_expkey, h);
 218         struct svc_expkey *new = container_of(b, struct svc_expkey, h);
 219
 220         if (orig->ek_fsidtype != new->ek_fsidtype ||
 221             orig->ek_client != new->ek_client ||
 222             memcmp(orig->ek_fsid, new->ek_fsid, key_len(orig->ek_fsidtype)) != 0)
 223                 return 0;
 224         return 1;
 225 }
 226
 227 static inline void expkey_init(struct cache_head *cnew,
 228                                    struct cache_head *citem)
 229 {
 230         struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
 231         struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
 232
 233         kref_get(&item->ek_client->ref);
 234         new->ek_client = item->ek_client;
 235         new->ek_fsidtype = item->ek_fsidtype;
 236         new->ek_fsid[0] = item->ek_fsid[0];
 237         new->ek_fsid[1] = item->ek_fsid[1];
 238         new->ek_fsid[2] = item->ek_fsid[2];
 239 }
 240
 241 static inline void expkey_update(struct cache_head *cnew,
 242                                    struct cache_head *citem)
 243 {
 244         struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
 245         struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
 246
 247         new->ek_mnt = mntget(item->ek_mnt);
 248         new->ek_dentry = dget(item->ek_dentry);
 249 }
 250
 251 static struct cache_head *expkey_alloc(void)
 252 {
 253         struct svc_expkey *i = kmalloc(sizeof(*i), GFP_KERNEL);
 254         if (i)
 255                 return &i->h;
 256         else
 257                 return NULL;
 258 }
 259
 260 static struct cache_detail svc_expkey_cache = {
 261         .owner          = THIS_MODULE,
 262         .hash_size      = EXPKEY_HASHMAX,
 263         .hash_table     = expkey_table,
 264         .name           = "nfsd.fh",
 265         .cache_put      = expkey_put,
 266         .cache_request  = expkey_request,
 267         .cache_parse    = expkey_parse,
 268         .cache_show     = expkey_show,
 269         .match          = expkey_match,
 270         .init           = expkey_init,
 271         .update         = expkey_update,
 272         .alloc          = expkey_alloc,
 273 };
 274
 275 static struct svc_expkey *
 276 svc_expkey_lookup(struct svc_expkey *item)
 277 {
 278         struct cache_head *ch;
 279         int hash = item->ek_fsidtype;
 280         char * cp = (char*)item->ek_fsid;
 281         int len = key_len(item->ek_fsidtype);
 282
 283         hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
 284         hash ^= hash_ptr(item->ek_client, EXPKEY_HASHBITS);
 285         hash &= EXPKEY_HASHMASK;
 286
 287         ch = sunrpc_cache_lookup(&svc_expkey_cache, &item->h,
 288                                  hash);
 289         if (ch)
 290                 return container_of(ch, struct svc_expkey, h);
 291         else
 292                 return NULL;
 293 }
 294
 295 static struct svc_expkey *
 296 svc_expkey_update(struct svc_expkey *new, struct svc_expkey *old)
 297 {
 298         struct cache_head *ch;
 299         int hash = new->ek_fsidtype;
 300         char * cp = (char*)new->ek_fsid;
 301         int len = key_len(new->ek_fsidtype);
 302
 303         hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
 304         hash ^= hash_ptr(new->ek_client, EXPKEY_HASHBITS);
 305         hash &= EXPKEY_HASHMASK;
 306
 307         ch = sunrpc_cache_update(&svc_expkey_cache, &new->h,
 308                                  &old->h, hash);
 309         if (ch)
 310                 return container_of(ch, struct svc_expkey, h);
 311         else
 312                 return NULL;
 313 }
 314
 315
 316 #define EXPORT_HASHBITS         8
 317 #define EXPORT_HASHMAX          (1<< EXPORT_HASHBITS)
 318 #define EXPORT_HASHMASK         (EXPORT_HASHMAX -1)
 319
 320 static struct cache_head *export_table[EXPORT_HASHMAX];
 321
 322 static void svc_export_put(struct kref *ref)
 323 {
 324         struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
 325         dput(exp->ex_dentry);
 326         mntput(exp->ex_mnt);
 327         auth_domain_put(exp->ex_client);
 328         kfree(exp);
 329 }
 330
 331 static void svc_export_request(struct cache_detail *cd,
 332                                struct cache_head *h,
 333                                char **bpp, int *blen)
 334 {
 335         /*  client path */
 336         struct svc_export *exp = container_of(h, struct svc_export, h);
 337         char *pth;
 338
 339         qword_add(bpp, blen, exp->ex_client->name);
 340         pth = d_path(exp->ex_dentry, exp->ex_mnt, *bpp, *blen);
 341         if (IS_ERR(pth)) {
 342                 /* is this correct? */
 343                 (*bpp)[0] = '\n';
 344                 return;
 345         }
 346         qword_add(bpp, blen, pth);
 347         (*bpp)[-1] = '\n';
 348 }
 349
 350 static struct svc_export *svc_export_update(struct svc_export *new,
 351                                             struct svc_export *old);
 352 static struct svc_export *svc_export_lookup(struct svc_export *);
 353
 354 static int check_export(struct inode *inode, int flags)
 355 {
 356
 357         /* We currently export only dirs and regular files.
 358          * This is what umountd does.
 359          */
 360         if (!S_ISDIR(inode->i_mode) &&
 361             !S_ISREG(inode->i_mode))
 362                 return -ENOTDIR;
 363
 364         /* There are two requirements on a filesystem to be exportable.
 365          * 1:  We must be able to identify the filesystem from a number.
 366          *       either a device number (so FS_REQUIRES_DEV needed)
 367          *       or an FSID number (so NFSEXP_FSID needed).
 368          * 2:  We must be able to find an inode from a filehandle.
 369          *       This means that s_export_op must be set.
 370          */
 371         if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) &&
 372             !(flags & NFSEXP_FSID)) {
 373                 dprintk("exp_export: export of non-dev fs without fsid");
 374                 return -EINVAL;
 375         }
 376         if (!inode->i_sb->s_export_op) {
 377                 dprintk("exp_export: export of invalid fs type.\n");
 378                 return -EINVAL;
 379         }
 380
 381         /* Ok, we can export it */;
 382         if (!inode->i_sb->s_export_op->find_exported_dentry)
 383                 inode->i_sb->s_export_op->find_exported_dentry =
 384                         find_exported_dentry;
 385         return 0;
 386
 387 }
 388
 389 static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
 390 {
 391         /* client path expiry [flags anonuid anongid fsid] */
 392         char *buf;
 393         int len;
 394         int err;
 395         struct auth_domain *dom = NULL;
 396         struct nameidata nd;
 397         struct svc_export exp, *expp;
 398         int an_int;
 399
 400         nd.dentry = NULL;
 401
 402         if (mesg[mlen-1] != '\n')
 403                 return -EINVAL;
 404         mesg[mlen-1] = 0;
 405
 406         buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 407         err = -ENOMEM;
 408         if (!buf) goto out;
 409
 410         /* client */
 411         len = qword_get(&mesg, buf, PAGE_SIZE);
 412         err = -EINVAL;
 413         if (len <= 0) goto out;
 414
 415         err = -ENOENT;
 416         dom = auth_domain_find(buf);
 417         if (!dom)
 418                 goto out;
 419
 420         /* path */
 421         err = -EINVAL;
 422         if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 423                 goto out;
 424         err = path_lookup(buf, 0, &nd);
 425         if (err) goto out;
 426
 427         exp.h.flags = 0;
 428         exp.ex_client = dom;
 429         exp.ex_mnt = nd.mnt;
 430         exp.ex_dentry = nd.dentry;
 431
 432         /* expiry */
 433         err = -EINVAL;
 434         exp.h.expiry_time = get_expiry(&mesg);
 435         if (exp.h.expiry_time == 0)
 436                 goto out;
 437
 438         /* flags */
 439         err = get_int(&mesg, &an_int);
 440         if (err == -ENOENT)
 441                 set_bit(CACHE_NEGATIVE, &exp.h.flags);
 442         else {
 443                 if (err || an_int < 0) goto out;
 444                 exp.ex_flags= an_int;
 445
 446                 /* anon uid */
 447                 err = get_int(&mesg, &an_int);
 448                 if (err) goto out;
 449                 exp.ex_anon_uid= an_int;
 450
 451                 /* anon gid */
 452                 err = get_int(&mesg, &an_int);
 453                 if (err) goto out;
 454                 exp.ex_anon_gid= an_int;
 455
 456                 /* fsid */
 457                 err = get_int(&mesg, &an_int);
 458                 if (err) goto out;
 459                 exp.ex_fsid = an_int;
 460
 461                 err = check_export(nd.dentry->d_inode, exp.ex_flags);
 462                 if (err) goto out;
 463         }
 464
 465         expp = svc_export_lookup(&exp);
 466         if (expp)
 467                 expp = svc_export_update(&exp, expp);
 468         else
 469                 err = -ENOMEM;
 470         cache_flush();
 471         if (expp == NULL)
 472                 err = -ENOMEM;
 473         else
 474                 exp_put(expp);
 475  out:
 476         if (nd.dentry)
 477                 path_release(&nd);
 478         if (dom)
 479                 auth_domain_put(dom);
 480         kfree(buf);
 481         return err;
 482 }
 483
 484 static void exp_flags(struct seq_file *m, int flag, int fsid, uid_t anonu, uid_t anong);
 485
 486 static int svc_export_show(struct seq_file *m,
 487                            struct cache_detail *cd,
 488                            struct cache_head *h)
 489 {
 490         struct svc_export *exp ;
 491
 492         if (h ==NULL) {
 493                 seq_puts(m, "#path domain(flags)\n");
 494                 return 0;
 495         }
 496         exp = container_of(h, struct svc_export, h);
 497         seq_path(m, exp->ex_mnt, exp->ex_dentry, " \t\n\\");
 498         seq_putc(m, '\t');
 499         seq_escape(m, exp->ex_client->name, " \t\n\\");
 500         seq_putc(m, '(');
 501         if (test_bit(CACHE_VALID, &h->flags) &&
 502             !test_bit(CACHE_NEGATIVE, &h->flags))
 503                 exp_flags(m, exp->ex_flags, exp->ex_fsid,
 504                           exp->ex_anon_uid, exp->ex_anon_gid);
 505         seq_puts(m, ")\n");
 506         return 0;
 507 }
 508 static int svc_export_match(struct cache_head *a, struct cache_head *b)
 509 {
 510         struct svc_export *orig = container_of(a, struct svc_export, h);
 511         struct svc_export *new = container_of(b, struct svc_export, h);
 512         return orig->ex_client == new->ex_client &&
 513                 orig->ex_dentry == new->ex_dentry &&
 514                 orig->ex_mnt == new->ex_mnt;
 515 }
 516
 517 static void svc_export_init(struct cache_head *cnew, struct cache_head *citem)
 518 {
 519         struct svc_export *new = container_of(cnew, struct svc_export, h);
 520         struct svc_export *item = container_of(citem, struct svc_export, h);
 521
 522         kref_get(&item->ex_client->ref);
 523         new->ex_client = item->ex_client;
 524         new->ex_dentry = dget(item->ex_dentry);
 525         new->ex_mnt = mntget(item->ex_mnt);
 526 }
 527
 528 static void export_update(struct cache_head *cnew, struct cache_head *citem)
 529 {
 530         struct svc_export *new = container_of(cnew, struct svc_export, h);
 531         struct svc_export *item = container_of(citem, struct svc_export, h);
 532
 533         new->ex_flags = item->ex_flags;
 534         new->ex_anon_uid = item->ex_anon_uid;
 535         new->ex_anon_gid = item->ex_anon_gid;
 536         new->ex_fsid = item->ex_fsid;
 537 }
 538
 539 static struct cache_head *svc_export_alloc(void)
 540 {
 541         struct svc_export *i = kmalloc(sizeof(*i), GFP_KERNEL);
 542         if (i)
 543                 return &i->h;
 544         else
 545                 return NULL;
 546 }
 547
 548 struct cache_detail svc_export_cache = {
 549         .owner          = THIS_MODULE,
 550         .hash_size      = EXPORT_HASHMAX,
 551         .hash_table     = export_table,
 552         .name           = "nfsd.export",
 553         .cache_put      = svc_export_put,
 554         .cache_request  = svc_export_request,
 555         .cache_parse    = svc_export_parse,
 556         .cache_show     = svc_export_show,
 557         .match          = svc_export_match,
 558         .init           = svc_export_init,
 559         .update         = export_update,
 560         .alloc          = svc_export_alloc,
 561 };
 562
 563 static struct svc_export *
 564 svc_export_lookup(struct svc_export *exp)
 565 {
 566         struct cache_head *ch;
 567         int hash;
 568         hash = hash_ptr(exp->ex_client, EXPORT_HASHBITS);
 569         hash ^= hash_ptr(exp->ex_dentry, EXPORT_HASHBITS);
 570         hash ^= hash_ptr(exp->ex_mnt, EXPORT_HASHBITS);
 571
 572         ch = sunrpc_cache_lookup(&svc_export_cache, &exp->h,
 573                                  hash);
 574         if (ch)
 575                 return container_of(ch, struct svc_export, h);
 576         else
 577                 return NULL;
 578 }
 579
 580 static struct svc_export *
 581 svc_export_update(struct svc_export *new, struct svc_export *old)
 582 {
 583         struct cache_head *ch;
 584         int hash;
 585         hash = hash_ptr(old->ex_client, EXPORT_HASHBITS);
 586         hash ^= hash_ptr(old->ex_dentry, EXPORT_HASHBITS);
 587         hash ^= hash_ptr(old->ex_mnt, EXPORT_HASHBITS);
 588
 589         ch = sunrpc_cache_update(&svc_export_cache, &new->h,
 590                                  &old->h,
 591                                  hash);
 592         if (ch)
 593                 return container_of(ch, struct svc_export, h);
 594         else
 595                 return NULL;
 596 }
 597
 598
 599 static struct svc_expkey *
 600 exp_find_key(svc_client *clp, int fsid_type, u32 *fsidv, struct cache_req *reqp)
 601 {
 602         struct svc_expkey key, *ek;
 603         int err;
 604
 605         if (!clp)
 606                 return NULL;
 607
 608         key.ek_client = clp;
 609         key.ek_fsidtype = fsid_type;
 610         memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
 611
 612         ek = svc_expkey_lookup(&key);
 613         if (ek != NULL)
 614                 if ((err = cache_check(&svc_expkey_cache, &ek->h, reqp)))
 615                         ek = ERR_PTR(err);
 616         return ek;
 617 }
 618
 619 static int exp_set_key(svc_client *clp, int fsid_type, u32 *fsidv,
 620                        struct svc_export *exp)
 621 {
 622         struct svc_expkey key, *ek;
 623
 624         key.ek_client = clp;
 625         key.ek_fsidtype = fsid_type;
 626         memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
 627         key.ek_mnt = exp->ex_mnt;
 628         key.ek_dentry = exp->ex_dentry;
 629         key.h.expiry_time = NEVER;
 630         key.h.flags = 0;
 631
 632         ek = svc_expkey_lookup(&key);
 633         if (ek)
 634                 ek = svc_expkey_update(&key,ek);
 635         if (ek) {
 636                 cache_put(&ek->h, &svc_expkey_cache);
 637                 return 0;
 638         }
 639         return -ENOMEM;
 640 }
 641
 642 /*
 643  * Find the client's export entry matching xdev/xino.
 644  */
 645 static inline struct svc_expkey *
 646 exp_get_key(svc_client *clp, dev_t dev, ino_t ino)
 647 {
 648         u32 fsidv[3];
 649
 650         if (old_valid_dev(dev)) {
 651                 mk_fsid_v0(fsidv, dev, ino);
 652                 return exp_find_key(clp, 0, fsidv, NULL);
 653         }
 654         mk_fsid_v3(fsidv, dev, ino);
 655         return exp_find_key(clp, 3, fsidv, NULL);
 656 }
 657
 658 /*
 659  * Find the client's export entry matching fsid
 660  */
 661 static inline struct svc_expkey *
 662 exp_get_fsid_key(svc_client *clp, int fsid)
 663 {
 664         u32 fsidv[2];
 665
 666         mk_fsid_v1(fsidv, fsid);
 667
 668         return exp_find_key(clp, 1, fsidv, NULL);
 669 }
 670
 671 svc_export *
 672 exp_get_by_name(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry,
 673                 struct cache_req *reqp)
 674 {
 675         struct svc_export *exp, key;
 676
 677         if (!clp)
 678                 return NULL;
 679
 680         key.ex_client = clp;
 681         key.ex_mnt = mnt;
 682         key.ex_dentry = dentry;
 683
 684         exp = svc_export_lookup(&key);
 685         if (exp != NULL)
 686                 switch (cache_check(&svc_export_cache, &exp->h, reqp)) {
 687                 case 0: break;
 688                 case -EAGAIN:
 689                         exp = ERR_PTR(-EAGAIN);
 690                         break;
 691                 default:
 692                         exp = NULL;
 693                 }
 694
 695         return exp;
 696 }
 697
 698 /*
 699  * Find the export entry for a given dentry.
 700  */
 701 struct svc_export *
 702 exp_parent(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry,
 703            struct cache_req *reqp)
 704 {
 705         svc_export *exp;
 706
 707         dget(dentry);
 708         exp = exp_get_by_name(clp, mnt, dentry, reqp);
 709
 710         while (exp == NULL && !IS_ROOT(dentry)) {
 711                 struct dentry *parent;
 712
 713                 parent = dget_parent(dentry);
 714                 dput(dentry);
 715                 dentry = parent;
 716                 exp = exp_get_by_name(clp, mnt, dentry, reqp);
 717         }
 718         dput(dentry);
 719         return exp;
 720 }
 721
 722 /*
 723  * Hashtable locking. Write locks are placed only by user processes
 724  * wanting to modify export information.
 725  * Write locking only done in this file.  Read locking
 726  * needed externally.
 727  */
 728
 729 static DECLARE_RWSEM(hash_sem);
 730
 731 void
 732 exp_readlock(void)
 733 {
 734         down_read(&hash_sem);
 735 }
 736
 737 static inline void
 738 exp_writelock(void)
 739 {
 740         down_write(&hash_sem);
 741 }
 742
 743 void
 744 exp_readunlock(void)
 745 {
 746         up_read(&hash_sem);
 747 }
 748
 749 static inline void
 750 exp_writeunlock(void)
 751 {
 752         up_write(&hash_sem);
 753 }
 754
 755 static void exp_fsid_unhash(struct svc_export *exp)
 756 {
 757         struct svc_expkey *ek;
 758
 759         if ((exp->ex_flags & NFSEXP_FSID) == 0)
 760                 return;
 761
 762         ek = exp_get_fsid_key(exp->ex_client, exp->ex_fsid);
 763         if (ek && !IS_ERR(ek)) {
 764                 ek->h.expiry_time = get_seconds()-1;
 765                 cache_put(&ek->h, &svc_expkey_cache);
 766         }
 767         svc_expkey_cache.nextcheck = get_seconds();
 768 }
 769
 770 static int exp_fsid_hash(svc_client *clp, struct svc_export *exp)
 771 {
 772         u32 fsid[2];
 773
 774         if ((exp->ex_flags & NFSEXP_FSID) == 0)
 775                 return 0;
 776
 777         mk_fsid_v1(fsid, exp->ex_fsid);
 778         return exp_set_key(clp, 1, fsid, exp);
 779 }
 780
 781 static int exp_hash(struct auth_domain *clp, struct svc_export *exp)
 782 {
 783         u32 fsid[2];
 784         struct inode *inode = exp->ex_dentry->d_inode;
 785         dev_t dev = inode->i_sb->s_dev;
 786
 787         if (old_valid_dev(dev)) {
 788                 mk_fsid_v0(fsid, dev, inode->i_ino);
 789                 return exp_set_key(clp, 0, fsid, exp);
 790         }
 791         mk_fsid_v3(fsid, dev, inode->i_ino);
 792         return exp_set_key(clp, 3, fsid, exp);
 793 }
 794
 795 static void exp_unhash(struct svc_export *exp)
 796 {
 797         struct svc_expkey *ek;
 798         struct inode *inode = exp->ex_dentry->d_inode;
 799
 800         ek = exp_get_key(exp->ex_client, inode->i_sb->s_dev, inode->i_ino);
 801         if (ek && !IS_ERR(ek)) {
 802                 ek->h.expiry_time = get_seconds()-1;
 803                 cache_put(&ek->h, &svc_expkey_cache);
 804         }
 805         svc_expkey_cache.nextcheck = get_seconds();
 806 }
 807
 808 /*
 809  * Export a file system.
 810  */
 811 int
 812 exp_export(struct nfsctl_export *nxp)
 813 {
 814         svc_client      *clp;
 815         struct svc_export       *exp = NULL;
 816         struct svc_export       new;
 817         struct svc_expkey       *fsid_key = NULL;
 818         struct nameidata nd;
 819         int             err;
 820
 821         /* Consistency check */
 822         err = -EINVAL;
 823         if (!exp_verify_string(nxp->ex_path, NFS_MAXPATHLEN) ||
 824             !exp_verify_string(nxp->ex_client, NFSCLNT_IDMAX))
 825                 goto out;
 826
 827         dprintk("exp_export called for %s:%s (%x/%ld fl %x).\n",
 828                         nxp->ex_client, nxp->ex_path,
 829                         (unsigned)nxp->ex_dev, (long)nxp->ex_ino,
 830                         nxp->ex_flags);
 831
 832         /* Try to lock the export table for update */
 833         exp_writelock();
 834
 835         /* Look up client info */
 836         if (!(clp = auth_domain_find(nxp->ex_client)))
 837                 goto out_unlock;
 838
 839
 840         /* Look up the dentry */
 841         err = path_lookup(nxp->ex_path, 0, &nd);
 842         if (err)
 843                 goto out_unlock;
 844         err = -EINVAL;
 845
 846         exp = exp_get_by_name(clp, nd.mnt, nd.dentry, NULL);
 847
 848         /* must make sure there won't be an ex_fsid clash */
 849         if ((nxp->ex_flags & NFSEXP_FSID) &&
 850             (fsid_key = exp_get_fsid_key(clp, nxp->ex_dev)) &&
 851             !IS_ERR(fsid_key) &&
 852             fsid_key->ek_mnt &&
 853             (fsid_key->ek_mnt != nd.mnt || fsid_key->ek_dentry != nd.dentry) )
 854                 goto finish;
 855
 856         if (exp) {
 857                 /* just a flags/id/fsid update */
 858
 859                 exp_fsid_unhash(exp);
 860                 exp->ex_flags    = nxp->ex_flags;
 861                 exp->ex_anon_uid = nxp->ex_anon_uid;
 862                 exp->ex_anon_gid = nxp->ex_anon_gid;
 863                 exp->ex_fsid     = nxp->ex_dev;
 864
 865                 err = exp_fsid_hash(clp, exp);
 866                 goto finish;
 867         }
 868
 869         err = check_export(nd.dentry->d_inode, nxp->ex_flags);
 870         if (err) goto finish;
 871
 872         err = -ENOMEM;
 873
 874         dprintk("nfsd: creating export entry %p for client %p\n", exp, clp);
 875
 876         new.h.expiry_time = NEVER;
 877         new.h.flags = 0;
 878         new.ex_client = clp;
 879         new.ex_mnt = nd.mnt;
 880         new.ex_dentry = nd.dentry;
 881         new.ex_flags = nxp->ex_flags;
 882         new.ex_anon_uid = nxp->ex_anon_uid;
 883         new.ex_anon_gid = nxp->ex_anon_gid;
 884         new.ex_fsid = nxp->ex_dev;
 885
 886         exp = svc_export_lookup(&new);
 887         if (exp)
 888                 exp = svc_export_update(&new, exp);
 889
 890         if (!exp)
 891                 goto finish;
 892
 893         if (exp_hash(clp, exp) ||
 894             exp_fsid_hash(clp, exp)) {
 895                 /* failed to create at least one index */
 896                 exp_do_unexport(exp);
 897                 cache_flush();
 898                 err = -ENOMEM;
 899         }
 900
 901 finish:
 902         if (exp)
 903                 exp_put(exp);
 904         if (fsid_key && !IS_ERR(fsid_key))
 905                 cache_put(&fsid_key->h, &svc_expkey_cache);
 906         if (clp)
 907                 auth_domain_put(clp);
 908         path_release(&nd);
 909 out_unlock:
 910         exp_writeunlock();
 911 out:
 912         return err;
 913 }
 914
 915 /*
 916  * Unexport a file system. The export entry has already
 917  * been removed from the client's list of exported fs's.
 918  */
 919 static void
 920 exp_do_unexport(svc_export *unexp)
 921 {
 922         unexp->h.expiry_time = get_seconds()-1;
 923         svc_export_cache.nextcheck = get_seconds();
 924         exp_unhash(unexp);
 925         exp_fsid_unhash(unexp);
 926 }
 927
 928
 929 /*
 930  * unexport syscall.
 931  */
 932 int
 933 exp_unexport(struct nfsctl_export *nxp)
 934 {
 935         struct auth_domain *dom;
 936         svc_export *exp;
 937         struct nameidata nd;
 938         int             err;
 939
 940         /* Consistency check */
 941         if (!exp_verify_string(nxp->ex_path, NFS_MAXPATHLEN) ||
 942             !exp_verify_string(nxp->ex_client, NFSCLNT_IDMAX))
 943                 return -EINVAL;
 944
 945         exp_writelock();
 946
 947         err = -EINVAL;
 948         dom = auth_domain_find(nxp->ex_client);
 949         if (!dom) {
 950                 dprintk("nfsd: unexport couldn't find %s\n", nxp->ex_client);
 951                 goto out_unlock;
 952         }
 953
 954         err = path_lookup(nxp->ex_path, 0, &nd);
 955         if (err)
 956                 goto out_domain;
 957
 958         err = -EINVAL;
 959         exp = exp_get_by_name(dom, nd.mnt, nd.dentry, NULL);
 960         path_release(&nd);
 961         if (!exp)
 962                 goto out_domain;
 963
 964         exp_do_unexport(exp);
 965         exp_put(exp);
 966         err = 0;
 967
 968 out_domain:
 969         auth_domain_put(dom);
 970         cache_flush();
 971 out_unlock:
 972         exp_writeunlock();
 973         return err;
 974 }
 975
 976 /*
 977  * Obtain the root fh on behalf of a client.
 978  * This could be done in user space, but I feel that it adds some safety
 979  * since its harder to fool a kernel module than a user space program.
 980  */
 981 int
 982 exp_rootfh(svc_client *clp, char *path, struct knfsd_fh *f, int maxsize)
 983 {
 984         struct svc_export       *exp;
 985         struct nameidata        nd;
 986         struct inode            *inode;
 987         struct svc_fh           fh;
 988         int                     err;
 989
 990         err = -EPERM;
 991         /* NB: we probably ought to check that it's NUL-terminated */
 992         if (path_lookup(path, 0, &nd)) {
 993                 printk("nfsd: exp_rootfh path not found %s", path);
 994                 return err;
 995         }
 996         inode = nd.dentry->d_inode;
 997
 998         dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
 999                  path, nd.dentry, clp->name,
1000                  inode->i_sb->s_id, inode->i_ino);
1001         exp = exp_parent(clp, nd.mnt, nd.dentry, NULL);
1002         if (!exp) {
1003                 dprintk("nfsd: exp_rootfh export not found.\n");
1004                 goto out;
1005         }
1006
1007         /*
1008          * fh must be initialized before calling fh_compose
1009          */
1010         fh_init(&fh, maxsize);
1011         if (fh_compose(&fh, exp, nd.dentry, NULL))
1012                 err = -EINVAL;
1013         else
1014                 err = 0;
1015         memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
1016         fh_put(&fh);
1017         exp_put(exp);
1018 out:
1019         path_release(&nd);
1020         return err;
1021 }
1022
1023 struct svc_export *
1024 exp_find(struct auth_domain *clp, int fsid_type, u32 *fsidv,
1025          struct cache_req *reqp)
1026 {
1027         struct svc_export *exp;
1028         struct svc_expkey *ek = exp_find_key(clp, fsid_type, fsidv, reqp);
1029         if (!ek || IS_ERR(ek))
1030                 return ERR_PTR(PTR_ERR(ek));
1031
1032         exp = exp_get_by_name(clp, ek->ek_mnt, ek->ek_dentry, reqp);
1033         cache_put(&ek->h, &svc_expkey_cache);
1034
1035         if (!exp || IS_ERR(exp))
1036                 return ERR_PTR(PTR_ERR(exp));
1037         return exp;
1038 }
1039
1040
1041 /*
1042  * Called when we need the filehandle for the root of the pseudofs,
1043  * for a given NFSv4 client.   The root is defined to be the
1044  * export point with fsid==0
1045  */
1046 int
1047 exp_pseudoroot(struct auth_domain *clp, struct svc_fh *fhp,
1048                struct cache_req *creq)
1049 {
1050         struct svc_expkey *fsid_key;
1051         struct svc_export *exp;
1052         int rv;
1053         u32 fsidv[2];
1054
1055         mk_fsid_v1(fsidv, 0);
1056
1057         fsid_key = exp_find_key(clp, 1, fsidv, creq);
1058         if (IS_ERR(fsid_key) && PTR_ERR(fsid_key) == -EAGAIN)
1059                 return nfserr_dropit;
1060         if (!fsid_key || IS_ERR(fsid_key))
1061                 return nfserr_perm;
1062
1063         exp = exp_get_by_name(clp, fsid_key->ek_mnt, fsid_key->ek_dentry, creq);
1064         if (exp == NULL)
1065                 rv = nfserr_perm;
1066         else if (IS_ERR(exp))
1067                 rv = nfserrno(PTR_ERR(exp));
1068         else
1069                 rv = fh_compose(fhp, exp,
1070                                 fsid_key->ek_dentry, NULL);
1071         cache_put(&fsid_key->h, &svc_expkey_cache);
1072         return rv;
1073 }
1074
1075 /* Iterator */
1076
1077 static void *e_start(struct seq_file *m, loff_t *pos)
1078 {
1079         loff_t n = *pos;
1080         unsigned hash, export;
1081         struct cache_head *ch;
1082
1083         exp_readlock();
1084         read_lock(&svc_export_cache.hash_lock);
1085         if (!n--)
1086                 return (void *)1;
1087         hash = n >> 32;
1088         export = n & ((1LL<<32) - 1);
1089
1090
1091         for (ch=export_table[hash]; ch; ch=ch->next)
1092                 if (!export--)
1093                         return ch;
1094         n &= ~((1LL<<32) - 1);
1095         do {
1096                 hash++;
1097                 n += 1LL<<32;
1098         } while(hash < EXPORT_HASHMAX && export_table[hash]==NULL);
1099         if (hash >= EXPORT_HASHMAX)
1100                 return NULL;
1101         *pos = n+1;
1102         return export_table[hash];
1103 }
1104
1105 static void *e_next(struct seq_file *m, void *p, loff_t *pos)
1106 {
1107         struct cache_head *ch = p;
1108         int hash = (*pos >> 32);
1109
1110         if (p == (void *)1)
1111                 hash = 0;
1112         else if (ch->next == NULL) {
1113                 hash++;
1114                 *pos += 1LL<<32;
1115         } else {
1116                 ++*pos;
1117                 return ch->next;
1118         }
1119         *pos &= ~((1LL<<32) - 1);
1120         while (hash < EXPORT_HASHMAX && export_table[hash] == NULL) {
1121                 hash++;
1122                 *pos += 1LL<<32;
1123         }
1124         if (hash >= EXPORT_HASHMAX)
1125                 return NULL;
1126         ++*pos;
1127         return export_table[hash];
1128 }
1129
1130 static void e_stop(struct seq_file *m, void *p)
1131 {
1132         read_unlock(&svc_export_cache.hash_lock);
1133         exp_readunlock();
1134 }
1135
1136 static struct flags {
1137         int flag;
1138         char *name[2];
1139 } expflags[] = {
1140         { NFSEXP_READONLY, {"ro", "rw"}},
1141         { NFSEXP_INSECURE_PORT, {"insecure", ""}},
1142         { NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
1143         { NFSEXP_ALLSQUASH, {"all_squash", ""}},
1144         { NFSEXP_ASYNC, {"async", "sync"}},
1145         { NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
1146         { NFSEXP_NOHIDE, {"nohide", ""}},
1147         { NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
1148         { NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
1149         { NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
1150 #ifdef MSNFS
1151         { NFSEXP_MSNFS, {"msnfs", ""}},
1152 #endif
1153         { 0, {"", ""}}
1154 };
1155
1156 static void exp_flags(struct seq_file *m, int flag, int fsid, uid_t anonu, uid_t anong)
1157 {
1158         int first = 0;
1159         struct flags *flg;
1160
1161         for (flg = expflags; flg->flag; flg++) {
1162                 int state = (flg->flag & flag)?0:1;
1163                 if (*flg->name[state])
1164                         seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
1165         }
1166         if (flag & NFSEXP_FSID)
1167                 seq_printf(m, "%sfsid=%d", first++?",":"", fsid);
1168         if (anonu != (uid_t)-2 && anonu != (0x10000-2))
1169                 seq_printf(m, "%sanonuid=%d", first++?",":"", anonu);
1170         if (anong != (gid_t)-2 && anong != (0x10000-2))
1171                 seq_printf(m, "%sanongid=%d", first++?",":"", anong);
1172 }
1173
1174 static int e_show(struct seq_file *m, void *p)
1175 {
1176         struct cache_head *cp = p;
1177         struct svc_export *exp = container_of(cp, struct svc_export, h);
1178         svc_client *clp;
1179
1180         if (p == (void *)1) {
1181                 seq_puts(m, "# Version 1.1\n");
1182                 seq_puts(m, "# Path Client(Flags) # IPs\n");
1183                 return 0;
1184         }
1185
1186         clp = exp->ex_client;
1187         cache_get(&exp->h);
1188         if (cache_check(&svc_export_cache, &exp->h, NULL))
1189                 return 0;
1190         cache_put(&exp->h, &svc_export_cache);
1191         return svc_export_show(m, &svc_export_cache, cp);
1192 }
1193
1194 struct seq_operations nfs_exports_op = {
1195         .start  = e_start,
1196         .next   = e_next,
1197         .stop   = e_stop,
1198         .show   = e_show,
1199 };
1200
1201 /*
1202  * Add or modify a client.
1203  * Change requests may involve the list of host addresses. The list of
1204  * exports and possibly existing uid maps are left untouched.
1205  */
1206 int
1207 exp_addclient(struct nfsctl_client *ncp)
1208 {
1209         struct auth_domain      *dom;
1210         int                     i, err;
1211
1212         /* First, consistency check. */
1213         err = -EINVAL;
1214         if (! exp_verify_string(ncp->cl_ident, NFSCLNT_IDMAX))
1215                 goto out;
1216         if (ncp->cl_naddr > NFSCLNT_ADDRMAX)
1217                 goto out;
1218
1219         /* Lock the hashtable */
1220         exp_writelock();
1221
1222         dom = unix_domain_find(ncp->cl_ident);
1223
1224         err = -ENOMEM;
1225         if (!dom)
1226                 goto out_unlock;
1227
1228         /* Insert client into hashtable. */
1229         for (i = 0; i < ncp->cl_naddr; i++)
1230                 auth_unix_add_addr(ncp->cl_addrlist[i], dom);
1231
1232         auth_unix_forget_old(dom);
1233         auth_domain_put(dom);
1234
1235         err = 0;
1236
1237 out_unlock:
1238         exp_writeunlock();
1239 out:
1240         return err;
1241 }
1242
1243 /*
1244  * Delete a client given an identifier.
1245  */
1246 int
1247 exp_delclient(struct nfsctl_client *ncp)
1248 {
1249         int             err;
1250         struct auth_domain *dom;
1251
1252         err = -EINVAL;
1253         if (!exp_verify_string(ncp->cl_ident, NFSCLNT_IDMAX))
1254                 goto out;
1255
1256         /* Lock the hashtable */
1257         exp_writelock();
1258
1259         dom = auth_domain_find(ncp->cl_ident);
1260         /* just make sure that no addresses work
1261          * and that it will expire soon
1262          */
1263         if (dom) {
1264                 err = auth_unix_forget_old(dom);
1265                 auth_domain_put(dom);
1266         }
1267
1268         exp_writeunlock();
1269 out:
1270         return err;
1271 }
1272
1273 /*
1274  * Verify that string is non-empty and does not exceed max length.
1275  */
1276 static int
1277 exp_verify_string(char *cp, int max)
1278 {
1279         int     i;
1280
1281         for (i = 0; i < max; i++)
1282                 if (!cp[i])
1283                         return i;
1284         cp[i] = 0;
1285         printk(KERN_NOTICE "nfsd: couldn't validate string %s\n", cp);
1286         return 0;
1287 }
1288
1289 /*
1290  * Initialize the exports module.
1291  */
1292 void
1293 nfsd_export_init(void)
1294 {
1295         dprintk("nfsd: initializing export module.\n");
1296
1297         cache_register(&svc_export_cache);
1298         cache_register(&svc_expkey_cache);
1299
1300 }
1301
1302 /*
1303  * Flush exports table - called when last nfsd thread is killed
1304  */
1305 void
1306 nfsd_export_flush(void)
1307 {
1308         exp_writelock();
1309         cache_purge(&svc_expkey_cache);
1310         cache_purge(&svc_export_cache);
1311         exp_writeunlock();
1312 }
1313
1314 /*
1315  * Shutdown the exports module.
1316  */
1317 void
1318 nfsd_export_shutdown(void)
1319 {
1320
1321         dprintk("nfsd: shutting down export module.\n");
1322
1323         exp_writelock();
1324
1325         if (cache_unregister(&svc_expkey_cache))
1326                 printk(KERN_ERR "nfsd: failed to unregister expkey cache\n");
1327         if (cache_unregister(&svc_export_cache))
1328                 printk(KERN_ERR "nfsd: failed to unregister export cache\n");
1329         svcauth_unix_purge();
1330
1331         exp_writeunlock();
1332         dprintk("nfsd: export shutdown complete.\n");
1333 }