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 static 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 static 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 static 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 static int check_export(struct inode *inode, int flags)
 309 {
 310
 311         /* We currently export only dirs and regular files.
 312          * This is what umountd does.
 313          */
 314         if (!S_ISDIR(inode->i_mode) &&
 315             !S_ISREG(inode->i_mode))
 316                 return -ENOTDIR;
 317
 318         /* There are two requirements on a filesystem to be exportable.
 319          * 1:  We must be able to identify the filesystem from a number.
 320          *       either a device number (so FS_REQUIRES_DEV needed)
 321          *       or an FSID number (so NFSEXP_FSID needed).
 322          * 2:  We must be able to find an inode from a filehandle.
 323          *       This means that s_export_op must be set.
 324          */
 325         if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) &&
 326             !(flags & NFSEXP_FSID)) {
 327                 dprintk("exp_export: export of non-dev fs without fsid");
 328                 return -EINVAL;
 329         }
 330         if (!inode->i_sb->s_export_op) {
 331                 dprintk("exp_export: export of invalid fs type.\n");
 332                 return -EINVAL;
 333         }
 334
 335         /* Ok, we can export it */;
 336         if (!inode->i_sb->s_export_op->find_exported_dentry)
 337                 inode->i_sb->s_export_op->find_exported_dentry =
 338                         find_exported_dentry;
 339         return 0;
 340
 341 }
 342
 343 static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
 344 {
 345         /* client path expiry [flags anonuid anongid fsid] */
 346         char *buf;
 347         int len;
 348         int err;
 349         struct auth_domain *dom = NULL;
 350         struct nameidata nd;
 351         struct svc_export exp, *expp;
 352         int an_int;
 353
 354         nd.dentry = NULL;
 355
 356         if (mesg[mlen-1] != '\n')
 357                 return -EINVAL;
 358         mesg[mlen-1] = 0;
 359
 360         buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 361         err = -ENOMEM;
 362         if (!buf) goto out;
 363
 364         /* client */
 365         len = qword_get(&mesg, buf, PAGE_SIZE);
 366         err = -EINVAL;
 367         if (len <= 0) goto out;
 368
 369         err = -ENOENT;
 370         dom = auth_domain_find(buf);
 371         if (!dom)
 372                 goto out;
 373
 374         /* path */
 375         err = -EINVAL;
 376         if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 377                 goto out;
 378         err = path_lookup(buf, 0, &nd);
 379         if (err) goto out;
 380
 381         exp.h.flags = 0;
 382         exp.ex_client = dom;
 383         exp.ex_mnt = nd.mnt;
 384         exp.ex_dentry = nd.dentry;
 385
 386         /* expiry */
 387         err = -EINVAL;
 388         exp.h.expiry_time = get_expiry(&mesg);
 389         if (exp.h.expiry_time == 0)
 390                 goto out;
 391
 392         /* flags */
 393         err = get_int(&mesg, &an_int);
 394         if (err == -ENOENT)
 395                 set_bit(CACHE_NEGATIVE, &exp.h.flags);
 396         else {
 397                 if (err || an_int < 0) goto out;
 398                 exp.ex_flags= an_int;
 399
 400                 /* anon uid */
 401                 err = get_int(&mesg, &an_int);
 402                 if (err) goto out;
 403                 exp.ex_anon_uid= an_int;
 404
 405                 /* anon gid */
 406                 err = get_int(&mesg, &an_int);
 407                 if (err) goto out;
 408                 exp.ex_anon_gid= an_int;
 409
 410                 /* fsid */
 411                 err = get_int(&mesg, &an_int);
 412                 if (err) goto out;
 413                 exp.ex_fsid = an_int;
 414
 415                 err = check_export(nd.dentry->d_inode, exp.ex_flags);
 416                 if (err) goto out;
 417         }
 418
 419         expp = svc_export_lookup(&exp, 1);
 420         if (expp)
 421                 exp_put(expp);
 422         err = 0;
 423         cache_flush();
 424  out:
 425         if (nd.dentry)
 426                 path_release(&nd);
 427         if (dom)
 428                 auth_domain_put(dom);
 429         if (buf)
 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         .hash_size      = EXPORT_HASHMAX,
 460         .hash_table     = export_table,
 461         .name           = "nfsd.export",
 462         .cache_put      = svc_export_put,
 463         .cache_request  = svc_export_request,
 464         .cache_parse    = svc_export_parse,
 465         .cache_show     = svc_export_show,
 466 };
 467
 468 static inline int svc_export_match(struct svc_export *a, struct svc_export *b)
 469 {
 470         return a->ex_client == b->ex_client &&
 471                 a->ex_dentry == b->ex_dentry &&
 472                 a->ex_mnt == b->ex_mnt;
 473 }
 474 static inline void svc_export_init(struct svc_export *new, struct svc_export *item)
 475 {
 476         cache_get(&item->ex_client->h);
 477         new->ex_client = item->ex_client;
 478         new->ex_dentry = dget(item->ex_dentry);
 479         new->ex_mnt = mntget(item->ex_mnt);
 480 }
 481
 482 static inline void svc_export_update(struct svc_export *new, struct svc_export *item)
 483 {
 484         new->ex_flags = item->ex_flags;
 485         new->ex_anon_uid = item->ex_anon_uid;
 486         new->ex_anon_gid = item->ex_anon_gid;
 487         new->ex_fsid = item->ex_fsid;
 488 }
 489
 490 static DefineSimpleCacheLookup(svc_export,1) /* allow inplace updates */
 491
 492
 493 struct svc_expkey *
 494 exp_find_key(svc_client *clp, int fsid_type, u32 *fsidv, struct cache_req *reqp)
 495 {
 496         struct svc_expkey key, *ek;
 497         int err;
 498
 499         if (!clp)
 500                 return NULL;
 501
 502         key.ek_client = clp;
 503         key.ek_fsidtype = fsid_type;
 504         memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
 505
 506         ek = svc_expkey_lookup(&key, 0);
 507         if (ek != NULL)
 508                 if ((err = cache_check(&svc_expkey_cache, &ek->h, reqp)))
 509                         ek = ERR_PTR(err);
 510         return ek;
 511 }
 512
 513 static int exp_set_key(svc_client *clp, int fsid_type, u32 *fsidv,
 514                        struct svc_export *exp)
 515 {
 516         struct svc_expkey key, *ek;
 517
 518         key.ek_client = clp;
 519         key.ek_fsidtype = fsid_type;
 520         memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
 521         key.ek_export = exp;
 522         key.h.expiry_time = NEVER;
 523         key.h.flags = 0;
 524
 525         ek = svc_expkey_lookup(&key, 1);
 526         if (ek) {
 527                 expkey_put(&ek->h, &svc_expkey_cache);
 528                 return 0;
 529         }
 530         return -ENOMEM;
 531 }
 532
 533 /*
 534  * Find the client's export entry matching xdev/xino.
 535  */
 536 static inline struct svc_expkey *
 537 exp_get_key(svc_client *clp, dev_t dev, ino_t ino)
 538 {
 539         u32 fsidv[3];
 540
 541         if (old_valid_dev(dev)) {
 542                 mk_fsid_v0(fsidv, dev, ino);
 543                 return exp_find_key(clp, 0, fsidv, NULL);
 544         }
 545         mk_fsid_v3(fsidv, dev, ino);
 546         return exp_find_key(clp, 3, fsidv, NULL);
 547 }
 548
 549 /*
 550  * Find the client's export entry matching fsid
 551  */
 552 static inline struct svc_expkey *
 553 exp_get_fsid_key(svc_client *clp, int fsid)
 554 {
 555         u32 fsidv[2];
 556
 557         mk_fsid_v1(fsidv, fsid);
 558
 559         return exp_find_key(clp, 1, fsidv, NULL);
 560 }
 561
 562 svc_export *
 563 exp_get_by_name(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry,
 564                 struct cache_req *reqp)
 565 {
 566         struct svc_export *exp, key;
 567
 568         if (!clp)
 569                 return NULL;
 570
 571         key.ex_client = clp;
 572         key.ex_mnt = mnt;
 573         key.ex_dentry = dentry;
 574
 575         exp = svc_export_lookup(&key, 0);
 576         if (exp != NULL)
 577                 switch (cache_check(&svc_export_cache, &exp->h, reqp)) {
 578                 case 0: break;
 579                 case -EAGAIN:
 580                         exp = ERR_PTR(-EAGAIN);
 581                         break;
 582                 default:
 583                         exp = NULL;
 584                 }
 585
 586         return exp;
 587 }
 588
 589 /*
 590  * Find the export entry for a given dentry.
 591  */
 592 struct svc_export *
 593 exp_parent(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry,
 594            struct cache_req *reqp)
 595 {
 596         svc_export *exp;
 597
 598         dget(dentry);
 599         exp = exp_get_by_name(clp, mnt, dentry, reqp);
 600
 601         while (exp == NULL && !IS_ROOT(dentry)) {
 602                 struct dentry *parent;
 603
 604                 parent = dget_parent(dentry);
 605                 dput(dentry);
 606                 dentry = parent;
 607                 exp = exp_get_by_name(clp, mnt, dentry, reqp);
 608         }
 609         dput(dentry);
 610         return exp;
 611 }
 612
 613 /*
 614  * Hashtable locking. Write locks are placed only by user processes
 615  * wanting to modify export information.
 616  * Write locking only done in this file.  Read locking
 617  * needed externally.
 618  */
 619
 620 static DECLARE_RWSEM(hash_sem);
 621
 622 void
 623 exp_readlock(void)
 624 {
 625         down_read(&hash_sem);
 626 }
 627
 628 static inline void
 629 exp_writelock(void)
 630 {
 631         down_write(&hash_sem);
 632 }
 633
 634 void
 635 exp_readunlock(void)
 636 {
 637         up_read(&hash_sem);
 638 }
 639
 640 static inline void
 641 exp_writeunlock(void)
 642 {
 643         up_write(&hash_sem);
 644 }
 645
 646 static void exp_fsid_unhash(struct svc_export *exp)
 647 {
 648         struct svc_expkey *ek;
 649
 650         if ((exp->ex_flags & NFSEXP_FSID) == 0)
 651                 return;
 652
 653         ek = exp_get_fsid_key(exp->ex_client, exp->ex_fsid);
 654         if (ek && !IS_ERR(ek)) {
 655                 ek->h.expiry_time = get_seconds()-1;
 656                 expkey_put(&ek->h, &svc_expkey_cache);
 657         }
 658         svc_expkey_cache.nextcheck = get_seconds();
 659 }
 660
 661 static int exp_fsid_hash(svc_client *clp, struct svc_export *exp)
 662 {
 663         u32 fsid[2];
 664
 665         if ((exp->ex_flags & NFSEXP_FSID) == 0)
 666                 return 0;
 667
 668         mk_fsid_v1(fsid, exp->ex_fsid);
 669         return exp_set_key(clp, 1, fsid, exp);
 670 }
 671
 672 static int exp_hash(struct auth_domain *clp, struct svc_export *exp)
 673 {
 674         u32 fsid[2];
 675         struct inode *inode = exp->ex_dentry->d_inode;
 676         dev_t dev = inode->i_sb->s_dev;
 677
 678         if (old_valid_dev(dev)) {
 679                 mk_fsid_v0(fsid, dev, inode->i_ino);
 680                 return exp_set_key(clp, 0, fsid, exp);
 681         }
 682         mk_fsid_v3(fsid, dev, inode->i_ino);
 683         return exp_set_key(clp, 3, fsid, exp);
 684 }
 685
 686 static void exp_unhash(struct svc_export *exp)
 687 {
 688         struct svc_expkey *ek;
 689         struct inode *inode = exp->ex_dentry->d_inode;
 690
 691         ek = exp_get_key(exp->ex_client, inode->i_sb->s_dev, inode->i_ino);
 692         if (ek && !IS_ERR(ek)) {
 693                 ek->h.expiry_time = get_seconds()-1;
 694                 expkey_put(&ek->h, &svc_expkey_cache);
 695         }
 696         svc_expkey_cache.nextcheck = get_seconds();
 697 }
 698
 699 /*
 700  * Export a file system.
 701  */
 702 int
 703 exp_export(struct nfsctl_export *nxp)
 704 {
 705         svc_client      *clp;
 706         struct svc_export       *exp = NULL;
 707         struct svc_export       new;
 708         struct svc_expkey       *fsid_key = NULL;
 709         struct nameidata nd;
 710         int             err;
 711
 712         /* Consistency check */
 713         err = -EINVAL;
 714         if (!exp_verify_string(nxp->ex_path, NFS_MAXPATHLEN) ||
 715             !exp_verify_string(nxp->ex_client, NFSCLNT_IDMAX))
 716                 goto out;
 717
 718         dprintk("exp_export called for %s:%s (%x/%ld fl %x).\n",
 719                         nxp->ex_client, nxp->ex_path,
 720                         (unsigned)nxp->ex_dev, (long)nxp->ex_ino,
 721                         nxp->ex_flags);
 722
 723         /* Try to lock the export table for update */
 724         exp_writelock();
 725
 726         /* Look up client info */
 727         if (!(clp = auth_domain_find(nxp->ex_client)))
 728                 goto out_unlock;
 729
 730
 731         /* Look up the dentry */
 732         err = path_lookup(nxp->ex_path, 0, &nd);
 733         if (err)
 734                 goto out_unlock;
 735         err = -EINVAL;
 736
 737         exp = exp_get_by_name(clp, nd.mnt, nd.dentry, NULL);
 738
 739         /* must make sure there won't be an ex_fsid clash */
 740         if ((nxp->ex_flags & NFSEXP_FSID) &&
 741             (fsid_key = exp_get_fsid_key(clp, nxp->ex_dev)) &&
 742             !IS_ERR(fsid_key) &&
 743             fsid_key->ek_export &&
 744             fsid_key->ek_export != exp)
 745                 goto finish;
 746
 747         if (exp) {
 748                 /* just a flags/id/fsid update */
 749
 750                 exp_fsid_unhash(exp);
 751                 exp->ex_flags    = nxp->ex_flags;
 752                 exp->ex_anon_uid = nxp->ex_anon_uid;
 753                 exp->ex_anon_gid = nxp->ex_anon_gid;
 754                 exp->ex_fsid     = nxp->ex_dev;
 755
 756                 err = exp_fsid_hash(clp, exp);
 757                 goto finish;
 758         }
 759
 760         err = check_export(nd.dentry->d_inode, nxp->ex_flags);
 761         if (err) goto finish;
 762
 763         err = -ENOMEM;
 764
 765         dprintk("nfsd: creating export entry %p for client %p\n", exp, clp);
 766
 767         new.h.expiry_time = NEVER;
 768         new.h.flags = 0;
 769         new.ex_client = clp;
 770         new.ex_mnt = nd.mnt;
 771         new.ex_dentry = nd.dentry;
 772         new.ex_flags = nxp->ex_flags;
 773         new.ex_anon_uid = nxp->ex_anon_uid;
 774         new.ex_anon_gid = nxp->ex_anon_gid;
 775         new.ex_fsid = nxp->ex_dev;
 776
 777         exp = svc_export_lookup(&new, 1);
 778
 779         if (exp == NULL)
 780                 goto finish;
 781
 782         err = 0;
 783
 784         if (exp_hash(clp, exp) ||
 785             exp_fsid_hash(clp, exp)) {
 786                 /* failed to create at least one index */
 787                 exp_do_unexport(exp);
 788                 cache_flush();
 789                 err = -ENOMEM;
 790         }
 791
 792 finish:
 793         if (exp)
 794                 exp_put(exp);
 795         if (fsid_key && !IS_ERR(fsid_key))
 796                 expkey_put(&fsid_key->h, &svc_expkey_cache);
 797         if (clp)
 798                 auth_domain_put(clp);
 799         path_release(&nd);
 800 out_unlock:
 801         exp_writeunlock();
 802 out:
 803         return err;
 804 }
 805
 806 /*
 807  * Unexport a file system. The export entry has already
 808  * been removed from the client's list of exported fs's.
 809  */
 810 static void
 811 exp_do_unexport(svc_export *unexp)
 812 {
 813         unexp->h.expiry_time = get_seconds()-1;
 814         svc_export_cache.nextcheck = get_seconds();
 815         exp_unhash(unexp);
 816         exp_fsid_unhash(unexp);
 817 }
 818
 819
 820 /*
 821  * unexport syscall.
 822  */
 823 int
 824 exp_unexport(struct nfsctl_export *nxp)
 825 {
 826         struct auth_domain *dom;
 827         svc_export *exp;
 828         struct nameidata nd;
 829         int             err;
 830
 831         /* Consistency check */
 832         if (!exp_verify_string(nxp->ex_path, NFS_MAXPATHLEN) ||
 833             !exp_verify_string(nxp->ex_client, NFSCLNT_IDMAX))
 834                 return -EINVAL;
 835
 836         exp_writelock();
 837
 838         err = -EINVAL;
 839         dom = auth_domain_find(nxp->ex_client);
 840         if (!dom) {
 841                 dprintk("nfsd: unexport couldn't find %s\n", nxp->ex_client);
 842                 goto out_unlock;
 843         }
 844
 845         err = path_lookup(nxp->ex_path, 0, &nd);
 846         if (err)
 847                 goto out_domain;
 848
 849         err = -EINVAL;
 850         exp = exp_get_by_name(dom, nd.mnt, nd.dentry, NULL);
 851         path_release(&nd);
 852         if (!exp)
 853                 goto out_domain;
 854
 855         exp_do_unexport(exp);
 856         exp_put(exp);
 857         err = 0;
 858
 859 out_domain:
 860         auth_domain_put(dom);
 861         cache_flush();
 862 out_unlock:
 863         exp_writeunlock();
 864         return err;
 865 }
 866
 867 /*
 868  * Obtain the root fh on behalf of a client.
 869  * This could be done in user space, but I feel that it adds some safety
 870  * since its harder to fool a kernel module than a user space program.
 871  */
 872 int
 873 exp_rootfh(svc_client *clp, char *path, struct knfsd_fh *f, int maxsize)
 874 {
 875         struct svc_export       *exp;
 876         struct nameidata        nd;
 877         struct inode            *inode;
 878         struct svc_fh           fh;
 879         int                     err;
 880
 881         err = -EPERM;
 882         /* NB: we probably ought to check that it's NUL-terminated */
 883         if (path_lookup(path, 0, &nd)) {
 884                 printk("nfsd: exp_rootfh path not found %s", path);
 885                 return err;
 886         }
 887         inode = nd.dentry->d_inode;
 888
 889         dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
 890                  path, nd.dentry, clp->name,
 891                  inode->i_sb->s_id, inode->i_ino);
 892         exp = exp_parent(clp, nd.mnt, nd.dentry, NULL);
 893         if (!exp) {
 894                 dprintk("nfsd: exp_rootfh export not found.\n");
 895                 goto out;
 896         }
 897
 898         /*
 899          * fh must be initialized before calling fh_compose
 900          */
 901         fh_init(&fh, maxsize);
 902         if (fh_compose(&fh, exp, nd.dentry, NULL))
 903                 err = -EINVAL;
 904         else
 905                 err = 0;
 906         memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
 907         fh_put(&fh);
 908         exp_put(exp);
 909 out:
 910         path_release(&nd);
 911         return err;
 912 }
 913
 914 /*
 915  * Called when we need the filehandle for the root of the pseudofs,
 916  * for a given NFSv4 client.   The root is defined to be the
 917  * export point with fsid==0
 918  */
 919 int
 920 exp_pseudoroot(struct auth_domain *clp, struct svc_fh *fhp,
 921                struct cache_req *creq)
 922 {
 923         struct svc_expkey *fsid_key;
 924         int rv;
 925         u32 fsidv[2];
 926
 927         mk_fsid_v1(fsidv, 0);
 928
 929         fsid_key = exp_find_key(clp, 1, fsidv, creq);
 930         if (IS_ERR(fsid_key) && PTR_ERR(fsid_key) == -EAGAIN)
 931                 return nfserr_dropit;
 932         if (!fsid_key || IS_ERR(fsid_key))
 933                 return nfserr_perm;
 934
 935         rv = fh_compose(fhp, fsid_key->ek_export,
 936                           fsid_key->ek_export->ex_dentry, NULL);
 937         expkey_put(&fsid_key->h, &svc_expkey_cache);
 938         return rv;
 939 }
 940
 941 /* Iterator */
 942
 943 static void *e_start(struct seq_file *m, loff_t *pos)
 944 {
 945         loff_t n = *pos;
 946         unsigned hash, export;
 947         struct cache_head *ch;
 948
 949         exp_readlock();
 950         read_lock(&svc_export_cache.hash_lock);
 951         if (!n--)
 952                 return (void *)1;
 953         hash = n >> 32;
 954         export = n & ((1LL<<32) - 1);
 955
 956
 957         for (ch=export_table[hash]; ch; ch=ch->next)
 958                 if (!export--)
 959                         return ch;
 960         n &= ~((1LL<<32) - 1);
 961         do {
 962                 hash++;
 963                 n += 1LL<<32;
 964         } while(hash < EXPORT_HASHMAX && export_table[hash]==NULL);
 965         if (hash >= EXPORT_HASHMAX)
 966                 return NULL;
 967         *pos = n+1;
 968         return export_table[hash];
 969 }
 970
 971 static void *e_next(struct seq_file *m, void *p, loff_t *pos)
 972 {
 973         struct cache_head *ch = p;
 974         int hash = (*pos >> 32);
 975
 976         if (p == (void *)1)
 977                 hash = 0;
 978         else if (ch->next == NULL) {
 979                 hash++;
 980                 *pos += 1LL<<32;
 981         } else {
 982                 ++*pos;
 983                 return ch->next;
 984         }
 985         *pos &= ~((1LL<<32) - 1);
 986         while (hash < EXPORT_HASHMAX && export_table[hash] == NULL) {
 987                 hash++;
 988                 *pos += 1LL<<32;
 989         }
 990         if (hash >= EXPORT_HASHMAX)
 991                 return NULL;
 992         ++*pos;
 993         return export_table[hash];
 994 }
 995
 996 static void e_stop(struct seq_file *m, void *p)
 997 {
 998         read_unlock(&svc_export_cache.hash_lock);
 999         exp_readunlock();
1000 }
1001
1002 static struct flags {
1003         int flag;
1004         char *name[2];
1005 } expflags[] = {
1006         { NFSEXP_READONLY, {"ro", "rw"}},
1007         { NFSEXP_INSECURE_PORT, {"insecure", ""}},
1008         { NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
1009         { NFSEXP_ALLSQUASH, {"all_squash", ""}},
1010         { NFSEXP_ASYNC, {"async", "sync"}},
1011         { NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
1012         { NFSEXP_NOHIDE, {"nohide", ""}},
1013         { NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
1014         { NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
1015         { NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
1016 #ifdef MSNFS
1017         { NFSEXP_MSNFS, {"msnfs", ""}},
1018 #endif
1019         { 0, {"", ""}}
1020 };
1021
1022 static void exp_flags(struct seq_file *m, int flag, int fsid, uid_t anonu, uid_t anong)
1023 {
1024         int first = 0;
1025         struct flags *flg;
1026
1027         for (flg = expflags; flg->flag; flg++) {
1028                 int state = (flg->flag & flag)?0:1;
1029                 if (*flg->name[state])
1030                         seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
1031         }
1032         if (flag & NFSEXP_FSID)
1033                 seq_printf(m, "%sfsid=%d", first++?",":"", fsid);
1034         if (anonu != (uid_t)-2 && anonu != (0x10000-2))
1035                 seq_printf(m, "%sanonuid=%d", first++?",":"", anonu);
1036         if (anong != (gid_t)-2 && anong != (0x10000-2))
1037                 seq_printf(m, "%sanongid=%d", first++?",":"", anong);
1038 }
1039
1040 static int e_show(struct seq_file *m, void *p)
1041 {
1042         struct cache_head *cp = p;
1043         struct svc_export *exp = container_of(cp, struct svc_export, h);
1044         svc_client *clp;
1045
1046         if (p == (void *)1) {
1047                 seq_puts(m, "# Version 1.1\n");
1048                 seq_puts(m, "# Path Client(Flags) # IPs\n");
1049                 return 0;
1050         }
1051
1052         clp = exp->ex_client;
1053         cache_get(&exp->h);
1054         if (cache_check(&svc_export_cache, &exp->h, NULL))
1055                 return 0;
1056         if (cache_put(&exp->h, &svc_export_cache)) BUG();
1057         return svc_export_show(m, &svc_export_cache, cp);
1058 }
1059
1060 struct seq_operations nfs_exports_op = {
1061         .start  = e_start,
1062         .next   = e_next,
1063         .stop   = e_stop,
1064         .show   = e_show,
1065 };
1066
1067 /*
1068  * Add or modify a client.
1069  * Change requests may involve the list of host addresses. The list of
1070  * exports and possibly existing uid maps are left untouched.
1071  */
1072 int
1073 exp_addclient(struct nfsctl_client *ncp)
1074 {
1075         struct auth_domain      *dom;
1076         int                     i, err;
1077
1078         /* First, consistency check. */
1079         err = -EINVAL;
1080         if (! exp_verify_string(ncp->cl_ident, NFSCLNT_IDMAX))
1081                 goto out;
1082         if (ncp->cl_naddr > NFSCLNT_ADDRMAX)
1083                 goto out;
1084
1085         /* Lock the hashtable */
1086         exp_writelock();
1087
1088         dom = unix_domain_find(ncp->cl_ident);
1089
1090         err = -ENOMEM;
1091         if (!dom)
1092                 goto out_unlock;
1093
1094         /* Insert client into hashtable. */
1095         for (i = 0; i < ncp->cl_naddr; i++)
1096                 auth_unix_add_addr(ncp->cl_addrlist[i], dom);
1097
1098         auth_unix_forget_old(dom);
1099         auth_domain_put(dom);
1100
1101         err = 0;
1102
1103 out_unlock:
1104         exp_writeunlock();
1105 out:
1106         return err;
1107 }
1108
1109 /*
1110  * Delete a client given an identifier.
1111  */
1112 int
1113 exp_delclient(struct nfsctl_client *ncp)
1114 {
1115         int             err;
1116         struct auth_domain *dom;
1117
1118         err = -EINVAL;
1119         if (!exp_verify_string(ncp->cl_ident, NFSCLNT_IDMAX))
1120                 goto out;
1121
1122         /* Lock the hashtable */
1123         exp_writelock();
1124
1125         dom = auth_domain_find(ncp->cl_ident);
1126         /* just make sure that no addresses work
1127          * and that it will expire soon
1128          */
1129         if (dom) {
1130                 err = auth_unix_forget_old(dom);
1131                 dom->h.expiry_time = get_seconds();
1132                 auth_domain_put(dom);
1133         }
1134
1135         exp_writeunlock();
1136 out:
1137         return err;
1138 }
1139
1140 /*
1141  * Verify that string is non-empty and does not exceed max length.
1142  */
1143 static int
1144 exp_verify_string(char *cp, int max)
1145 {
1146         int     i;
1147
1148         for (i = 0; i < max; i++)
1149                 if (!cp[i])
1150                         return i;
1151         cp[i] = 0;
1152         printk(KERN_NOTICE "nfsd: couldn't validate string %s\n", cp);
1153         return 0;
1154 }
1155
1156 /*
1157  * Initialize the exports module.
1158  */
1159 void
1160 nfsd_export_init(void)
1161 {
1162         dprintk("nfsd: initializing export module.\n");
1163
1164         cache_register(&svc_export_cache);
1165         cache_register(&svc_expkey_cache);
1166
1167 }
1168
1169 /*
1170  * Flush exports table - called when last nfsd thread is killed
1171  */
1172 void
1173 nfsd_export_flush(void)
1174 {
1175         exp_writelock();
1176         cache_purge(&svc_expkey_cache);
1177         cache_purge(&svc_export_cache);
1178         exp_writeunlock();
1179 }
1180
1181 /*
1182  * Shutdown the exports module.
1183  */
1184 void
1185 nfsd_export_shutdown(void)
1186 {
1187
1188         dprintk("nfsd: shutting down export module.\n");
1189
1190         exp_writelock();
1191
1192         if (cache_unregister(&svc_expkey_cache))
1193                 printk(KERN_ERR "nfsd: failed to unregister expkey cache\n");
1194         if (cache_unregister(&svc_export_cache))
1195                 printk(KERN_ERR "nfsd: failed to unregister export cache\n");
1196         svcauth_unix_purge();
1197
1198         exp_writeunlock();
1199         dprintk("nfsd: export shutdown complete.\n");
1200 }