linux/fs/nfsd/export.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * NFS exporting and validation.
   4 *
   5 * We maintain a list of clients, each of which has a list of
   6 * exports. To export an fs to a given client, you first have
   7 * to create the client entry with NFSCTL_ADDCLIENT, which
   8 * creates a client control block and adds it to the hash
   9 * table. Then, you call NFSCTL_EXPORT for each fs.
  10 *
  11 *
  12 * Copyright (C) 1995, 1996 Olaf Kirch, <okir@monad.swb.de>
  13 */
  14
  15#include <linux/slab.h>
  16#include <linux/namei.h>
  17#include <linux/module.h>
  18#include <linux/exportfs.h>
  19#include <linux/sunrpc/svc_xprt.h>
  20
  21#include "nfsd.h"
  22#include "nfsfh.h"
  23#include "netns.h"
  24#include "pnfs.h"
  25
  26#define NFSDDBG_FACILITY        NFSDDBG_EXPORT
  27
  28/*
  29 * We have two caches.
  30 * One maps client+vfsmnt+dentry to export options - the export map
  31 * The other maps client+filehandle-fragment to export options. - the expkey map
  32 *
  33 * The export options are actually stored in the first map, and the
  34 * second map contains a reference to the entry in the first map.
  35 */
  36
  37#define EXPKEY_HASHBITS         8
  38#define EXPKEY_HASHMAX          (1 << EXPKEY_HASHBITS)
  39#define EXPKEY_HASHMASK         (EXPKEY_HASHMAX -1)
  40
  41static void expkey_put(struct kref *ref)
  42{
  43        struct svc_expkey *key = container_of(ref, struct svc_expkey, h.ref);
  44
  45        if (test_bit(CACHE_VALID, &key->h.flags) &&
  46            !test_bit(CACHE_NEGATIVE, &key->h.flags))
  47                path_put(&key->ek_path);
  48        auth_domain_put(key->ek_client);
  49        kfree(key);
  50}
  51
  52static void expkey_request(struct cache_detail *cd,
  53                           struct cache_head *h,
  54                           char **bpp, int *blen)
  55{
  56        /* client fsidtype \xfsid */
  57        struct svc_expkey *ek = container_of(h, struct svc_expkey, h);
  58        char type[5];
  59
  60        qword_add(bpp, blen, ek->ek_client->name);
  61        snprintf(type, 5, "%d", ek->ek_fsidtype);
  62        qword_add(bpp, blen, type);
  63        qword_addhex(bpp, blen, (char*)ek->ek_fsid, key_len(ek->ek_fsidtype));
  64        (*bpp)[-1] = '\n';
  65}
  66
  67static struct svc_expkey *svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
  68                                            struct svc_expkey *old);
  69static struct svc_expkey *svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *);
  70
  71static int expkey_parse(struct cache_detail *cd, char *mesg, int mlen)
  72{
  73        /* client fsidtype fsid expiry [path] */
  74        char *buf;
  75        int len;
  76        struct auth_domain *dom = NULL;
  77        int err;
  78        int fsidtype;
  79        char *ep;
  80        struct svc_expkey key;
  81        struct svc_expkey *ek = NULL;
  82
  83        if (mesg[mlen - 1] != '\n')
  84                return -EINVAL;
  85        mesg[mlen-1] = 0;
  86
  87        buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
  88        err = -ENOMEM;
  89        if (!buf)
  90                goto out;
  91
  92        err = -EINVAL;
  93        if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
  94                goto out;
  95
  96        err = -ENOENT;
  97        dom = auth_domain_find(buf);
  98        if (!dom)
  99                goto out;
 100        dprintk("found domain %s\n", buf);
 101
 102        err = -EINVAL;
 103        if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 104                goto out;
 105        fsidtype = simple_strtoul(buf, &ep, 10);
 106        if (*ep)
 107                goto out;
 108        dprintk("found fsidtype %d\n", fsidtype);
 109        if (key_len(fsidtype)==0) /* invalid type */
 110                goto out;
 111        if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 112                goto out;
 113        dprintk("found fsid length %d\n", len);
 114        if (len != key_len(fsidtype))
 115                goto out;
 116
 117        /* OK, we seem to have a valid key */
 118        key.h.flags = 0;
 119        key.h.expiry_time = get_expiry(&mesg);
 120        if (key.h.expiry_time == 0)
 121                goto out;
 122
 123        key.ek_client = dom;    
 124        key.ek_fsidtype = fsidtype;
 125        memcpy(key.ek_fsid, buf, len);
 126
 127        ek = svc_expkey_lookup(cd, &key);
 128        err = -ENOMEM;
 129        if (!ek)
 130                goto out;
 131
 132        /* now we want a pathname, or empty meaning NEGATIVE  */
 133        err = -EINVAL;
 134        len = qword_get(&mesg, buf, PAGE_SIZE);
 135        if (len < 0)
 136                goto out;
 137        dprintk("Path seems to be <%s>\n", buf);
 138        err = 0;
 139        if (len == 0) {
 140                set_bit(CACHE_NEGATIVE, &key.h.flags);
 141                ek = svc_expkey_update(cd, &key, ek);
 142                if (!ek)
 143                        err = -ENOMEM;
 144        } else {
 145                err = kern_path(buf, 0, &key.ek_path);
 146                if (err)
 147                        goto out;
 148
 149                dprintk("Found the path %s\n", buf);
 150
 151                ek = svc_expkey_update(cd, &key, ek);
 152                if (!ek)
 153                        err = -ENOMEM;
 154                path_put(&key.ek_path);
 155        }
 156        cache_flush();
 157 out:
 158        if (ek)
 159                cache_put(&ek->h, cd);
 160        if (dom)
 161                auth_domain_put(dom);
 162        kfree(buf);
 163        return err;
 164}
 165
 166static int expkey_show(struct seq_file *m,
 167                       struct cache_detail *cd,
 168                       struct cache_head *h)
 169{
 170        struct svc_expkey *ek ;
 171        int i;
 172
 173        if (h ==NULL) {
 174                seq_puts(m, "#domain fsidtype fsid [path]\n");
 175                return 0;
 176        }
 177        ek = container_of(h, struct svc_expkey, h);
 178        seq_printf(m, "%s %d 0x", ek->ek_client->name,
 179                   ek->ek_fsidtype);
 180        for (i=0; i < key_len(ek->ek_fsidtype)/4; i++)
 181                seq_printf(m, "%08x", ek->ek_fsid[i]);
 182        if (test_bit(CACHE_VALID, &h->flags) && 
 183            !test_bit(CACHE_NEGATIVE, &h->flags)) {
 184                seq_printf(m, " ");
 185                seq_path(m, &ek->ek_path, "\\ \t\n");
 186        }
 187        seq_printf(m, "\n");
 188        return 0;
 189}
 190
 191static inline int expkey_match (struct cache_head *a, struct cache_head *b)
 192{
 193        struct svc_expkey *orig = container_of(a, struct svc_expkey, h);
 194        struct svc_expkey *new = container_of(b, struct svc_expkey, h);
 195
 196        if (orig->ek_fsidtype != new->ek_fsidtype ||
 197            orig->ek_client != new->ek_client ||
 198            memcmp(orig->ek_fsid, new->ek_fsid, key_len(orig->ek_fsidtype)) != 0)
 199                return 0;
 200        return 1;
 201}
 202
 203static inline void expkey_init(struct cache_head *cnew,
 204                                   struct cache_head *citem)
 205{
 206        struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
 207        struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
 208
 209        kref_get(&item->ek_client->ref);
 210        new->ek_client = item->ek_client;
 211        new->ek_fsidtype = item->ek_fsidtype;
 212
 213        memcpy(new->ek_fsid, item->ek_fsid, sizeof(new->ek_fsid));
 214}
 215
 216static inline void expkey_update(struct cache_head *cnew,
 217                                   struct cache_head *citem)
 218{
 219        struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
 220        struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
 221
 222        new->ek_path = item->ek_path;
 223        path_get(&item->ek_path);
 224}
 225
 226static struct cache_head *expkey_alloc(void)
 227{
 228        struct svc_expkey *i = kmalloc(sizeof(*i), GFP_KERNEL);
 229        if (i)
 230                return &i->h;
 231        else
 232                return NULL;
 233}
 234
 235static const struct cache_detail svc_expkey_cache_template = {
 236        .owner          = THIS_MODULE,
 237        .hash_size      = EXPKEY_HASHMAX,
 238        .name           = "nfsd.fh",
 239        .cache_put      = expkey_put,
 240        .cache_request  = expkey_request,
 241        .cache_parse    = expkey_parse,
 242        .cache_show     = expkey_show,
 243        .match          = expkey_match,
 244        .init           = expkey_init,
 245        .update         = expkey_update,
 246        .alloc          = expkey_alloc,
 247};
 248
 249static int
 250svc_expkey_hash(struct svc_expkey *item)
 251{
 252        int hash = item->ek_fsidtype;
 253        char * cp = (char*)item->ek_fsid;
 254        int len = key_len(item->ek_fsidtype);
 255
 256        hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
 257        hash ^= hash_ptr(item->ek_client, EXPKEY_HASHBITS);
 258        hash &= EXPKEY_HASHMASK;
 259        return hash;
 260}
 261
 262static struct svc_expkey *
 263svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *item)
 264{
 265        struct cache_head *ch;
 266        int hash = svc_expkey_hash(item);
 267
 268        ch = sunrpc_cache_lookup(cd, &item->h, hash);
 269        if (ch)
 270                return container_of(ch, struct svc_expkey, h);
 271        else
 272                return NULL;
 273}
 274
 275static struct svc_expkey *
 276svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
 277                  struct svc_expkey *old)
 278{
 279        struct cache_head *ch;
 280        int hash = svc_expkey_hash(new);
 281
 282        ch = sunrpc_cache_update(cd, &new->h, &old->h, hash);
 283        if (ch)
 284                return container_of(ch, struct svc_expkey, h);
 285        else
 286                return NULL;
 287}
 288
 289
 290#define EXPORT_HASHBITS         8
 291#define EXPORT_HASHMAX          (1<< EXPORT_HASHBITS)
 292
 293static void nfsd4_fslocs_free(struct nfsd4_fs_locations *fsloc)
 294{
 295        struct nfsd4_fs_location *locations = fsloc->locations;
 296        int i;
 297
 298        if (!locations)
 299                return;
 300
 301        for (i = 0; i < fsloc->locations_count; i++) {
 302                kfree(locations[i].path);
 303                kfree(locations[i].hosts);
 304        }
 305
 306        kfree(locations);
 307        fsloc->locations = NULL;
 308}
 309
 310static void svc_export_put(struct kref *ref)
 311{
 312        struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
 313        path_put(&exp->ex_path);
 314        auth_domain_put(exp->ex_client);
 315        nfsd4_fslocs_free(&exp->ex_fslocs);
 316        kfree(exp->ex_uuid);
 317        kfree(exp);
 318}
 319
 320static void svc_export_request(struct cache_detail *cd,
 321                               struct cache_head *h,
 322                               char **bpp, int *blen)
 323{
 324        /*  client path */
 325        struct svc_export *exp = container_of(h, struct svc_export, h);
 326        char *pth;
 327
 328        qword_add(bpp, blen, exp->ex_client->name);
 329        pth = d_path(&exp->ex_path, *bpp, *blen);
 330        if (IS_ERR(pth)) {
 331                /* is this correct? */
 332                (*bpp)[0] = '\n';
 333                return;
 334        }
 335        qword_add(bpp, blen, pth);
 336        (*bpp)[-1] = '\n';
 337}
 338
 339static struct svc_export *svc_export_update(struct svc_export *new,
 340                                            struct svc_export *old);
 341static struct svc_export *svc_export_lookup(struct svc_export *);
 342
 343static int check_export(struct inode *inode, int *flags, unsigned char *uuid)
 344{
 345
 346        /*
 347         * We currently export only dirs, regular files, and (for v4
 348         * pseudoroot) symlinks.
 349         */
 350        if (!S_ISDIR(inode->i_mode) &&
 351            !S_ISLNK(inode->i_mode) &&
 352            !S_ISREG(inode->i_mode))
 353                return -ENOTDIR;
 354
 355        /*
 356         * Mountd should never pass down a writeable V4ROOT export, but,
 357         * just to make sure:
 358         */
 359        if (*flags & NFSEXP_V4ROOT)
 360                *flags |= NFSEXP_READONLY;
 361
 362        /* There are two requirements on a filesystem to be exportable.
 363         * 1:  We must be able to identify the filesystem from a number.
 364         *       either a device number (so FS_REQUIRES_DEV needed)
 365         *       or an FSID number (so NFSEXP_FSID or ->uuid is needed).
 366         * 2:  We must be able to find an inode from a filehandle.
 367         *       This means that s_export_op must be set.
 368         */
 369        if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) &&
 370            !(*flags & NFSEXP_FSID) &&
 371            uuid == NULL) {
 372                dprintk("exp_export: export of non-dev fs without fsid\n");
 373                return -EINVAL;
 374        }
 375
 376        if (!inode->i_sb->s_export_op ||
 377            !inode->i_sb->s_export_op->fh_to_dentry) {
 378                dprintk("exp_export: export of invalid fs type.\n");
 379                return -EINVAL;
 380        }
 381
 382        return 0;
 383
 384}
 385
 386#ifdef CONFIG_NFSD_V4
 387
 388static int
 389fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc)
 390{
 391        int len;
 392        int migrated, i, err;
 393
 394        /* more than one fsloc */
 395        if (fsloc->locations)
 396                return -EINVAL;
 397
 398        /* listsize */
 399        err = get_uint(mesg, &fsloc->locations_count);
 400        if (err)
 401                return err;
 402        if (fsloc->locations_count > MAX_FS_LOCATIONS)
 403                return -EINVAL;
 404        if (fsloc->locations_count == 0)
 405                return 0;
 406
 407        fsloc->locations = kcalloc(fsloc->locations_count,
 408                                   sizeof(struct nfsd4_fs_location),
 409                                   GFP_KERNEL);
 410        if (!fsloc->locations)
 411                return -ENOMEM;
 412        for (i=0; i < fsloc->locations_count; i++) {
 413                /* colon separated host list */
 414                err = -EINVAL;
 415                len = qword_get(mesg, buf, PAGE_SIZE);
 416                if (len <= 0)
 417                        goto out_free_all;
 418                err = -ENOMEM;
 419                fsloc->locations[i].hosts = kstrdup(buf, GFP_KERNEL);
 420                if (!fsloc->locations[i].hosts)
 421                        goto out_free_all;
 422                err = -EINVAL;
 423                /* slash separated path component list */
 424                len = qword_get(mesg, buf, PAGE_SIZE);
 425                if (len <= 0)
 426                        goto out_free_all;
 427                err = -ENOMEM;
 428                fsloc->locations[i].path = kstrdup(buf, GFP_KERNEL);
 429                if (!fsloc->locations[i].path)
 430                        goto out_free_all;
 431        }
 432        /* migrated */
 433        err = get_int(mesg, &migrated);
 434        if (err)
 435                goto out_free_all;
 436        err = -EINVAL;
 437        if (migrated < 0 || migrated > 1)
 438                goto out_free_all;
 439        fsloc->migrated = migrated;
 440        return 0;
 441out_free_all:
 442        nfsd4_fslocs_free(fsloc);
 443        return err;
 444}
 445
 446static int secinfo_parse(char **mesg, char *buf, struct svc_export *exp)
 447{
 448        struct exp_flavor_info *f;
 449        u32 listsize;
 450        int err;
 451
 452        /* more than one secinfo */
 453        if (exp->ex_nflavors)
 454                return -EINVAL;
 455
 456        err = get_uint(mesg, &listsize);
 457        if (err)
 458                return err;
 459        if (listsize > MAX_SECINFO_LIST)
 460                return -EINVAL;
 461
 462        for (f = exp->ex_flavors; f < exp->ex_flavors + listsize; f++) {
 463                err = get_uint(mesg, &f->pseudoflavor);
 464                if (err)
 465                        return err;
 466                /*
 467                 * XXX: It would be nice to also check whether this
 468                 * pseudoflavor is supported, so we can discover the
 469                 * problem at export time instead of when a client fails
 470                 * to authenticate.
 471                 */
 472                err = get_uint(mesg, &f->flags);
 473                if (err)
 474                        return err;
 475                /* Only some flags are allowed to differ between flavors: */
 476                if (~NFSEXP_SECINFO_FLAGS & (f->flags ^ exp->ex_flags))
 477                        return -EINVAL;
 478        }
 479        exp->ex_nflavors = listsize;
 480        return 0;
 481}
 482
 483#else /* CONFIG_NFSD_V4 */
 484static inline int
 485fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc){return 0;}
 486static inline int
 487secinfo_parse(char **mesg, char *buf, struct svc_export *exp) { return 0; }
 488#endif
 489
 490static inline int
 491nfsd_uuid_parse(char **mesg, char *buf, unsigned char **puuid)
 492{
 493        int len;
 494
 495        /* more than one uuid */
 496        if (*puuid)
 497                return -EINVAL;
 498
 499        /* expect a 16 byte uuid encoded as \xXXXX... */
 500        len = qword_get(mesg, buf, PAGE_SIZE);
 501        if (len != EX_UUID_LEN)
 502                return -EINVAL;
 503
 504        *puuid = kmemdup(buf, EX_UUID_LEN, GFP_KERNEL);
 505        if (*puuid == NULL)
 506                return -ENOMEM;
 507
 508        return 0;
 509}
 510
 511static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
 512{
 513        /* client path expiry [flags anonuid anongid fsid] */
 514        char *buf;
 515        int len;
 516        int err;
 517        struct auth_domain *dom = NULL;
 518        struct svc_export exp = {}, *expp;
 519        int an_int;
 520
 521        if (mesg[mlen-1] != '\n')
 522                return -EINVAL;
 523        mesg[mlen-1] = 0;
 524
 525        buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 526        if (!buf)
 527                return -ENOMEM;
 528
 529        /* client */
 530        err = -EINVAL;
 531        len = qword_get(&mesg, buf, PAGE_SIZE);
 532        if (len <= 0)
 533                goto out;
 534
 535        err = -ENOENT;
 536        dom = auth_domain_find(buf);
 537        if (!dom)
 538                goto out;
 539
 540        /* path */
 541        err = -EINVAL;
 542        if ((len = qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 543                goto out1;
 544
 545        err = kern_path(buf, 0, &exp.ex_path);
 546        if (err)
 547                goto out1;
 548
 549        exp.ex_client = dom;
 550        exp.cd = cd;
 551        exp.ex_devid_map = NULL;
 552
 553        /* expiry */
 554        err = -EINVAL;
 555        exp.h.expiry_time = get_expiry(&mesg);
 556        if (exp.h.expiry_time == 0)
 557                goto out3;
 558
 559        /* flags */
 560        err = get_int(&mesg, &an_int);
 561        if (err == -ENOENT) {
 562                err = 0;
 563                set_bit(CACHE_NEGATIVE, &exp.h.flags);
 564        } else {
 565                if (err || an_int < 0)
 566                        goto out3;
 567                exp.ex_flags= an_int;
 568        
 569                /* anon uid */
 570                err = get_int(&mesg, &an_int);
 571                if (err)
 572                        goto out3;
 573                exp.ex_anon_uid= make_kuid(&init_user_ns, an_int);
 574
 575                /* anon gid */
 576                err = get_int(&mesg, &an_int);
 577                if (err)
 578                        goto out3;
 579                exp.ex_anon_gid= make_kgid(&init_user_ns, an_int);
 580
 581                /* fsid */
 582                err = get_int(&mesg, &an_int);
 583                if (err)
 584                        goto out3;
 585                exp.ex_fsid = an_int;
 586
 587                while ((len = qword_get(&mesg, buf, PAGE_SIZE)) > 0) {
 588                        if (strcmp(buf, "fsloc") == 0)
 589                                err = fsloc_parse(&mesg, buf, &exp.ex_fslocs);
 590                        else if (strcmp(buf, "uuid") == 0)
 591                                err = nfsd_uuid_parse(&mesg, buf, &exp.ex_uuid);
 592                        else if (strcmp(buf, "secinfo") == 0)
 593                                err = secinfo_parse(&mesg, buf, &exp);
 594                        else
 595                                /* quietly ignore unknown words and anything
 596                                 * following. Newer user-space can try to set
 597                                 * new values, then see what the result was.
 598                                 */
 599                                break;
 600                        if (err)
 601                                goto out4;
 602                }
 603
 604                err = check_export(d_inode(exp.ex_path.dentry), &exp.ex_flags,
 605                                   exp.ex_uuid);
 606                if (err)
 607                        goto out4;
 608                /*
 609                 * No point caching this if it would immediately expire.
 610                 * Also, this protects exportfs's dummy export from the
 611                 * anon_uid/anon_gid checks:
 612                 */
 613                if (exp.h.expiry_time < seconds_since_boot())
 614                        goto out4;
 615                /*
 616                 * For some reason exportfs has been passing down an
 617                 * invalid (-1) uid & gid on the "dummy" export which it
 618                 * uses to test export support.  To make sure exportfs
 619                 * sees errors from check_export we therefore need to
 620                 * delay these checks till after check_export:
 621                 */
 622                err = -EINVAL;
 623                if (!uid_valid(exp.ex_anon_uid))
 624                        goto out4;
 625                if (!gid_valid(exp.ex_anon_gid))
 626                        goto out4;
 627                err = 0;
 628
 629                nfsd4_setup_layout_type(&exp);
 630        }
 631
 632        expp = svc_export_lookup(&exp);
 633        if (expp)
 634                expp = svc_export_update(&exp, expp);
 635        else
 636                err = -ENOMEM;
 637        cache_flush();
 638        if (expp == NULL)
 639                err = -ENOMEM;
 640        else
 641                exp_put(expp);
 642out4:
 643        nfsd4_fslocs_free(&exp.ex_fslocs);
 644        kfree(exp.ex_uuid);
 645out3:
 646        path_put(&exp.ex_path);
 647out1:
 648        auth_domain_put(dom);
 649out:
 650        kfree(buf);
 651        return err;
 652}
 653
 654static void exp_flags(struct seq_file *m, int flag, int fsid,
 655                kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fslocs);
 656static void show_secinfo(struct seq_file *m, struct svc_export *exp);
 657
 658static int svc_export_show(struct seq_file *m,
 659                           struct cache_detail *cd,
 660                           struct cache_head *h)
 661{
 662        struct svc_export *exp ;
 663
 664        if (h ==NULL) {
 665                seq_puts(m, "#path domain(flags)\n");
 666                return 0;
 667        }
 668        exp = container_of(h, struct svc_export, h);
 669        seq_path(m, &exp->ex_path, " \t\n\\");
 670        seq_putc(m, '\t');
 671        seq_escape(m, exp->ex_client->name, " \t\n\\");
 672        seq_putc(m, '(');
 673        if (test_bit(CACHE_VALID, &h->flags) && 
 674            !test_bit(CACHE_NEGATIVE, &h->flags)) {
 675                exp_flags(m, exp->ex_flags, exp->ex_fsid,
 676                          exp->ex_anon_uid, exp->ex_anon_gid, &exp->ex_fslocs);
 677                if (exp->ex_uuid) {
 678                        int i;
 679                        seq_puts(m, ",uuid=");
 680                        for (i = 0; i < EX_UUID_LEN; i++) {
 681                                if ((i&3) == 0 && i)
 682                                        seq_putc(m, ':');
 683                                seq_printf(m, "%02x", exp->ex_uuid[i]);
 684                        }
 685                }
 686                show_secinfo(m, exp);
 687        }
 688        seq_puts(m, ")\n");
 689        return 0;
 690}
 691static int svc_export_match(struct cache_head *a, struct cache_head *b)
 692{
 693        struct svc_export *orig = container_of(a, struct svc_export, h);
 694        struct svc_export *new = container_of(b, struct svc_export, h);
 695        return orig->ex_client == new->ex_client &&
 696                path_equal(&orig->ex_path, &new->ex_path);
 697}
 698
 699static void svc_export_init(struct cache_head *cnew, struct cache_head *citem)
 700{
 701        struct svc_export *new = container_of(cnew, struct svc_export, h);
 702        struct svc_export *item = container_of(citem, struct svc_export, h);
 703
 704        kref_get(&item->ex_client->ref);
 705        new->ex_client = item->ex_client;
 706        new->ex_path = item->ex_path;
 707        path_get(&item->ex_path);
 708        new->ex_fslocs.locations = NULL;
 709        new->ex_fslocs.locations_count = 0;
 710        new->ex_fslocs.migrated = 0;
 711        new->ex_layout_types = 0;
 712        new->ex_uuid = NULL;
 713        new->cd = item->cd;
 714}
 715
 716static void export_update(struct cache_head *cnew, struct cache_head *citem)
 717{
 718        struct svc_export *new = container_of(cnew, struct svc_export, h);
 719        struct svc_export *item = container_of(citem, struct svc_export, h);
 720        int i;
 721
 722        new->ex_flags = item->ex_flags;
 723        new->ex_anon_uid = item->ex_anon_uid;
 724        new->ex_anon_gid = item->ex_anon_gid;
 725        new->ex_fsid = item->ex_fsid;
 726        new->ex_devid_map = item->ex_devid_map;
 727        item->ex_devid_map = NULL;
 728        new->ex_uuid = item->ex_uuid;
 729        item->ex_uuid = NULL;
 730        new->ex_fslocs.locations = item->ex_fslocs.locations;
 731        item->ex_fslocs.locations = NULL;
 732        new->ex_fslocs.locations_count = item->ex_fslocs.locations_count;
 733        item->ex_fslocs.locations_count = 0;
 734        new->ex_fslocs.migrated = item->ex_fslocs.migrated;
 735        item->ex_fslocs.migrated = 0;
 736        new->ex_layout_types = item->ex_layout_types;
 737        new->ex_nflavors = item->ex_nflavors;
 738        for (i = 0; i < MAX_SECINFO_LIST; i++) {
 739                new->ex_flavors[i] = item->ex_flavors[i];
 740        }
 741}
 742
 743static struct cache_head *svc_export_alloc(void)
 744{
 745        struct svc_export *i = kmalloc(sizeof(*i), GFP_KERNEL);
 746        if (i)
 747                return &i->h;
 748        else
 749                return NULL;
 750}
 751
 752static const struct cache_detail svc_export_cache_template = {
 753        .owner          = THIS_MODULE,
 754        .hash_size      = EXPORT_HASHMAX,
 755        .name           = "nfsd.export",
 756        .cache_put      = svc_export_put,
 757        .cache_request  = svc_export_request,
 758        .cache_parse    = svc_export_parse,
 759        .cache_show     = svc_export_show,
 760        .match          = svc_export_match,
 761        .init           = svc_export_init,
 762        .update         = export_update,
 763        .alloc          = svc_export_alloc,
 764};
 765
 766static int
 767svc_export_hash(struct svc_export *exp)
 768{
 769        int hash;
 770
 771        hash = hash_ptr(exp->ex_client, EXPORT_HASHBITS);
 772        hash ^= hash_ptr(exp->ex_path.dentry, EXPORT_HASHBITS);
 773        hash ^= hash_ptr(exp->ex_path.mnt, EXPORT_HASHBITS);
 774        return hash;
 775}
 776
 777static struct svc_export *
 778svc_export_lookup(struct svc_export *exp)
 779{
 780        struct cache_head *ch;
 781        int hash = svc_export_hash(exp);
 782
 783        ch = sunrpc_cache_lookup(exp->cd, &exp->h, hash);
 784        if (ch)
 785                return container_of(ch, struct svc_export, h);
 786        else
 787                return NULL;
 788}
 789
 790static struct svc_export *
 791svc_export_update(struct svc_export *new, struct svc_export *old)
 792{
 793        struct cache_head *ch;
 794        int hash = svc_export_hash(old);
 795
 796        ch = sunrpc_cache_update(old->cd, &new->h, &old->h, hash);
 797        if (ch)
 798                return container_of(ch, struct svc_export, h);
 799        else
 800                return NULL;
 801}
 802
 803
 804static struct svc_expkey *
 805exp_find_key(struct cache_detail *cd, struct auth_domain *clp, int fsid_type,
 806             u32 *fsidv, struct cache_req *reqp)
 807{
 808        struct svc_expkey key, *ek;
 809        int err;
 810        
 811        if (!clp)
 812                return ERR_PTR(-ENOENT);
 813
 814        key.ek_client = clp;
 815        key.ek_fsidtype = fsid_type;
 816        memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
 817
 818        ek = svc_expkey_lookup(cd, &key);
 819        if (ek == NULL)
 820                return ERR_PTR(-ENOMEM);
 821        err = cache_check(cd, &ek->h, reqp);
 822        if (err)
 823                return ERR_PTR(err);
 824        return ek;
 825}
 826
 827static struct svc_export *
 828exp_get_by_name(struct cache_detail *cd, struct auth_domain *clp,
 829                const struct path *path, struct cache_req *reqp)
 830{
 831        struct svc_export *exp, key;
 832        int err;
 833
 834        if (!clp)
 835                return ERR_PTR(-ENOENT);
 836
 837        key.ex_client = clp;
 838        key.ex_path = *path;
 839        key.cd = cd;
 840
 841        exp = svc_export_lookup(&key);
 842        if (exp == NULL)
 843                return ERR_PTR(-ENOMEM);
 844        err = cache_check(cd, &exp->h, reqp);
 845        if (err)
 846                return ERR_PTR(err);
 847        return exp;
 848}
 849
 850/*
 851 * Find the export entry for a given dentry.
 852 */
 853static struct svc_export *
 854exp_parent(struct cache_detail *cd, struct auth_domain *clp, struct path *path)
 855{
 856        struct dentry *saved = dget(path->dentry);
 857        struct svc_export *exp = exp_get_by_name(cd, clp, path, NULL);
 858
 859        while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
 860                struct dentry *parent = dget_parent(path->dentry);
 861                dput(path->dentry);
 862                path->dentry = parent;
 863                exp = exp_get_by_name(cd, clp, path, NULL);
 864        }
 865        dput(path->dentry);
 866        path->dentry = saved;
 867        return exp;
 868}
 869
 870
 871
 872/*
 873 * Obtain the root fh on behalf of a client.
 874 * This could be done in user space, but I feel that it adds some safety
 875 * since its harder to fool a kernel module than a user space program.
 876 */
 877int
 878exp_rootfh(struct net *net, struct auth_domain *clp, char *name,
 879           struct knfsd_fh *f, int maxsize)
 880{
 881        struct svc_export       *exp;
 882        struct path             path;
 883        struct inode            *inode;
 884        struct svc_fh           fh;
 885        int                     err;
 886        struct nfsd_net         *nn = net_generic(net, nfsd_net_id);
 887        struct cache_detail     *cd = nn->svc_export_cache;
 888
 889        err = -EPERM;
 890        /* NB: we probably ought to check that it's NUL-terminated */
 891        if (kern_path(name, 0, &path)) {
 892                printk("nfsd: exp_rootfh path not found %s", name);
 893                return err;
 894        }
 895        inode = d_inode(path.dentry);
 896
 897        dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
 898                 name, path.dentry, clp->name,
 899                 inode->i_sb->s_id, inode->i_ino);
 900        exp = exp_parent(cd, clp, &path);
 901        if (IS_ERR(exp)) {
 902                err = PTR_ERR(exp);
 903                goto out;
 904        }
 905
 906        /*
 907         * fh must be initialized before calling fh_compose
 908         */
 909        fh_init(&fh, maxsize);
 910        if (fh_compose(&fh, exp, path.dentry, NULL))
 911                err = -EINVAL;
 912        else
 913                err = 0;
 914        memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
 915        fh_put(&fh);
 916        exp_put(exp);
 917out:
 918        path_put(&path);
 919        return err;
 920}
 921
 922static struct svc_export *exp_find(struct cache_detail *cd,
 923                                   struct auth_domain *clp, int fsid_type,
 924                                   u32 *fsidv, struct cache_req *reqp)
 925{
 926        struct svc_export *exp;
 927        struct nfsd_net *nn = net_generic(cd->net, nfsd_net_id);
 928        struct svc_expkey *ek = exp_find_key(nn->svc_expkey_cache, clp, fsid_type, fsidv, reqp);
 929        if (IS_ERR(ek))
 930                return ERR_CAST(ek);
 931
 932        exp = exp_get_by_name(cd, clp, &ek->ek_path, reqp);
 933        cache_put(&ek->h, nn->svc_expkey_cache);
 934
 935        if (IS_ERR(exp))
 936                return ERR_CAST(exp);
 937        return exp;
 938}
 939
 940__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp)
 941{
 942        struct exp_flavor_info *f;
 943        struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
 944
 945        /* legacy gss-only clients are always OK: */
 946        if (exp->ex_client == rqstp->rq_gssclient)
 947                return 0;
 948        /* ip-address based client; check sec= export option: */
 949        for (f = exp->ex_flavors; f < end; f++) {
 950                if (f->pseudoflavor == rqstp->rq_cred.cr_flavor)
 951                        return 0;
 952        }
 953        /* defaults in absence of sec= options: */
 954        if (exp->ex_nflavors == 0) {
 955                if (rqstp->rq_cred.cr_flavor == RPC_AUTH_NULL ||
 956                    rqstp->rq_cred.cr_flavor == RPC_AUTH_UNIX)
 957                        return 0;
 958        }
 959
 960        /* If the compound op contains a spo_must_allowed op,
 961         * it will be sent with integrity/protection which
 962         * will have to be expressly allowed on mounts that
 963         * don't support it
 964         */
 965
 966        if (nfsd4_spo_must_allow(rqstp))
 967                return 0;
 968
 969        return nfserr_wrongsec;
 970}
 971
 972/*
 973 * Uses rq_client and rq_gssclient to find an export; uses rq_client (an
 974 * auth_unix client) if it's available and has secinfo information;
 975 * otherwise, will try to use rq_gssclient.
 976 *
 977 * Called from functions that handle requests; functions that do work on
 978 * behalf of mountd are passed a single client name to use, and should
 979 * use exp_get_by_name() or exp_find().
 980 */
 981struct svc_export *
 982rqst_exp_get_by_name(struct svc_rqst *rqstp, struct path *path)
 983{
 984        struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
 985        struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 986        struct cache_detail *cd = nn->svc_export_cache;
 987
 988        if (rqstp->rq_client == NULL)
 989                goto gss;
 990
 991        /* First try the auth_unix client: */
 992        exp = exp_get_by_name(cd, rqstp->rq_client, path, &rqstp->rq_chandle);
 993        if (PTR_ERR(exp) == -ENOENT)
 994                goto gss;
 995        if (IS_ERR(exp))
 996                return exp;
 997        /* If it has secinfo, assume there are no gss/... clients */
 998        if (exp->ex_nflavors > 0)
 999                return exp;
1000gss:
1001        /* Otherwise, try falling back on gss client */
1002        if (rqstp->rq_gssclient == NULL)
1003                return exp;
1004        gssexp = exp_get_by_name(cd, rqstp->rq_gssclient, path, &rqstp->rq_chandle);
1005        if (PTR_ERR(gssexp) == -ENOENT)
1006                return exp;
1007        if (!IS_ERR(exp))
1008                exp_put(exp);
1009        return gssexp;
1010}
1011
1012struct svc_export *
1013rqst_exp_find(struct svc_rqst *rqstp, int fsid_type, u32 *fsidv)
1014{
1015        struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
1016        struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1017        struct cache_detail *cd = nn->svc_export_cache;
1018
1019        if (rqstp->rq_client == NULL)
1020                goto gss;
1021
1022        /* First try the auth_unix client: */
1023        exp = exp_find(cd, rqstp->rq_client, fsid_type,
1024                       fsidv, &rqstp->rq_chandle);
1025        if (PTR_ERR(exp) == -ENOENT)
1026                goto gss;
1027        if (IS_ERR(exp))
1028                return exp;
1029        /* If it has secinfo, assume there are no gss/... clients */
1030        if (exp->ex_nflavors > 0)
1031                return exp;
1032gss:
1033        /* Otherwise, try falling back on gss client */
1034        if (rqstp->rq_gssclient == NULL)
1035                return exp;
1036        gssexp = exp_find(cd, rqstp->rq_gssclient, fsid_type, fsidv,
1037                                                &rqstp->rq_chandle);
1038        if (PTR_ERR(gssexp) == -ENOENT)
1039                return exp;
1040        if (!IS_ERR(exp))
1041                exp_put(exp);
1042        return gssexp;
1043}
1044
1045struct svc_export *
1046rqst_exp_parent(struct svc_rqst *rqstp, struct path *path)
1047{
1048        struct dentry *saved = dget(path->dentry);
1049        struct svc_export *exp = rqst_exp_get_by_name(rqstp, path);
1050
1051        while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
1052                struct dentry *parent = dget_parent(path->dentry);
1053                dput(path->dentry);
1054                path->dentry = parent;
1055                exp = rqst_exp_get_by_name(rqstp, path);
1056        }
1057        dput(path->dentry);
1058        path->dentry = saved;
1059        return exp;
1060}
1061
1062struct svc_export *rqst_find_fsidzero_export(struct svc_rqst *rqstp)
1063{
1064        u32 fsidv[2];
1065
1066        mk_fsid(FSID_NUM, fsidv, 0, 0, 0, NULL);
1067
1068        return rqst_exp_find(rqstp, FSID_NUM, fsidv);
1069}
1070
1071/*
1072 * Called when we need the filehandle for the root of the pseudofs,
1073 * for a given NFSv4 client.   The root is defined to be the
1074 * export point with fsid==0
1075 */
1076__be32
1077exp_pseudoroot(struct svc_rqst *rqstp, struct svc_fh *fhp)
1078{
1079        struct svc_export *exp;
1080        __be32 rv;
1081
1082        exp = rqst_find_fsidzero_export(rqstp);
1083        if (IS_ERR(exp))
1084                return nfserrno(PTR_ERR(exp));
1085        rv = fh_compose(fhp, exp, exp->ex_path.dentry, NULL);
1086        exp_put(exp);
1087        return rv;
1088}
1089
1090static struct flags {
1091        int flag;
1092        char *name[2];
1093} expflags[] = {
1094        { NFSEXP_READONLY, {"ro", "rw"}},
1095        { NFSEXP_INSECURE_PORT, {"insecure", ""}},
1096        { NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
1097        { NFSEXP_ALLSQUASH, {"all_squash", ""}},
1098        { NFSEXP_ASYNC, {"async", "sync"}},
1099        { NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
1100        { NFSEXP_NOREADDIRPLUS, {"nordirplus", ""}},
1101        { NFSEXP_NOHIDE, {"nohide", ""}},
1102        { NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
1103        { NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
1104        { NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
1105        { NFSEXP_V4ROOT, {"v4root", ""}},
1106        { NFSEXP_PNFS, {"pnfs", ""}},
1107        { NFSEXP_SECURITY_LABEL, {"security_label", ""}},
1108        { 0, {"", ""}}
1109};
1110
1111static void show_expflags(struct seq_file *m, int flags, int mask)
1112{
1113        struct flags *flg;
1114        int state, first = 0;
1115
1116        for (flg = expflags; flg->flag; flg++) {
1117                if (flg->flag & ~mask)
1118                        continue;
1119                state = (flg->flag & flags) ? 0 : 1;
1120                if (*flg->name[state])
1121                        seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
1122        }
1123}
1124
1125static void show_secinfo_flags(struct seq_file *m, int flags)
1126{
1127        seq_printf(m, ",");
1128        show_expflags(m, flags, NFSEXP_SECINFO_FLAGS);
1129}
1130
1131static bool secinfo_flags_equal(int f, int g)
1132{
1133        f &= NFSEXP_SECINFO_FLAGS;
1134        g &= NFSEXP_SECINFO_FLAGS;
1135        return f == g;
1136}
1137
1138static int show_secinfo_run(struct seq_file *m, struct exp_flavor_info **fp, struct exp_flavor_info *end)
1139{
1140        int flags;
1141
1142        flags = (*fp)->flags;
1143        seq_printf(m, ",sec=%d", (*fp)->pseudoflavor);
1144        (*fp)++;
1145        while (*fp != end && secinfo_flags_equal(flags, (*fp)->flags)) {
1146                seq_printf(m, ":%d", (*fp)->pseudoflavor);
1147                (*fp)++;
1148        }
1149        return flags;
1150}
1151
1152static void show_secinfo(struct seq_file *m, struct svc_export *exp)
1153{
1154        struct exp_flavor_info *f;
1155        struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
1156        int flags;
1157
1158        if (exp->ex_nflavors == 0)
1159                return;
1160        f = exp->ex_flavors;
1161        flags = show_secinfo_run(m, &f, end);
1162        if (!secinfo_flags_equal(flags, exp->ex_flags))
1163                show_secinfo_flags(m, flags);
1164        while (f != end) {
1165                flags = show_secinfo_run(m, &f, end);
1166                show_secinfo_flags(m, flags);
1167        }
1168}
1169
1170static void exp_flags(struct seq_file *m, int flag, int fsid,
1171                kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fsloc)
1172{
1173        show_expflags(m, flag, NFSEXP_ALLFLAGS);
1174        if (flag & NFSEXP_FSID)
1175                seq_printf(m, ",fsid=%d", fsid);
1176        if (!uid_eq(anonu, make_kuid(&init_user_ns, (uid_t)-2)) &&
1177            !uid_eq(anonu, make_kuid(&init_user_ns, 0x10000-2)))
1178                seq_printf(m, ",anonuid=%u", from_kuid(&init_user_ns, anonu));
1179        if (!gid_eq(anong, make_kgid(&init_user_ns, (gid_t)-2)) &&
1180            !gid_eq(anong, make_kgid(&init_user_ns, 0x10000-2)))
1181                seq_printf(m, ",anongid=%u", from_kgid(&init_user_ns, anong));
1182        if (fsloc && fsloc->locations_count > 0) {
1183                char *loctype = (fsloc->migrated) ? "refer" : "replicas";
1184                int i;
1185
1186                seq_printf(m, ",%s=", loctype);
1187                seq_escape(m, fsloc->locations[0].path, ",;@ \t\n\\");
1188                seq_putc(m, '@');
1189                seq_escape(m, fsloc->locations[0].hosts, ",;@ \t\n\\");
1190                for (i = 1; i < fsloc->locations_count; i++) {
1191                        seq_putc(m, ';');
1192                        seq_escape(m, fsloc->locations[i].path, ",;@ \t\n\\");
1193                        seq_putc(m, '@');
1194                        seq_escape(m, fsloc->locations[i].hosts, ",;@ \t\n\\");
1195                }
1196        }
1197}
1198
1199static int e_show(struct seq_file *m, void *p)
1200{
1201        struct cache_head *cp = p;
1202        struct svc_export *exp = container_of(cp, struct svc_export, h);
1203        struct cache_detail *cd = m->private;
1204
1205        if (p == SEQ_START_TOKEN) {
1206                seq_puts(m, "# Version 1.1\n");
1207                seq_puts(m, "# Path Client(Flags) # IPs\n");
1208                return 0;
1209        }
1210
1211        exp_get(exp);
1212        if (cache_check(cd, &exp->h, NULL))
1213                return 0;
1214        exp_put(exp);
1215        return svc_export_show(m, cd, cp);
1216}
1217
1218const struct seq_operations nfs_exports_op = {
1219        .start  = cache_seq_start,
1220        .next   = cache_seq_next,
1221        .stop   = cache_seq_stop,
1222        .show   = e_show,
1223};
1224
1225/*
1226 * Initialize the exports module.
1227 */
1228int
1229nfsd_export_init(struct net *net)
1230{
1231        int rv;
1232        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1233
1234        dprintk("nfsd: initializing export module (net: %x).\n", net->ns.inum);
1235
1236        nn->svc_export_cache = cache_create_net(&svc_export_cache_template, net);
1237        if (IS_ERR(nn->svc_export_cache))
1238                return PTR_ERR(nn->svc_export_cache);
1239        rv = cache_register_net(nn->svc_export_cache, net);
1240        if (rv)
1241                goto destroy_export_cache;
1242
1243        nn->svc_expkey_cache = cache_create_net(&svc_expkey_cache_template, net);
1244        if (IS_ERR(nn->svc_expkey_cache)) {
1245                rv = PTR_ERR(nn->svc_expkey_cache);
1246                goto unregister_export_cache;
1247        }
1248        rv = cache_register_net(nn->svc_expkey_cache, net);
1249        if (rv)
1250                goto destroy_expkey_cache;
1251        return 0;
1252
1253destroy_expkey_cache:
1254        cache_destroy_net(nn->svc_expkey_cache, net);
1255unregister_export_cache:
1256        cache_unregister_net(nn->svc_export_cache, net);
1257destroy_export_cache:
1258        cache_destroy_net(nn->svc_export_cache, net);
1259        return rv;
1260}
1261
1262/*
1263 * Flush exports table - called when last nfsd thread is killed
1264 */
1265void
1266nfsd_export_flush(struct net *net)
1267{
1268        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1269
1270        cache_purge(nn->svc_expkey_cache);
1271        cache_purge(nn->svc_export_cache);
1272}
1273
1274/*
1275 * Shutdown the exports module.
1276 */
1277void
1278nfsd_export_shutdown(struct net *net)
1279{
1280        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1281
1282        dprintk("nfsd: shutting down export module (net: %x).\n", net->ns.inum);
1283
1284        cache_unregister_net(nn->svc_expkey_cache, net);
1285        cache_unregister_net(nn->svc_export_cache, net);
1286        cache_destroy_net(nn->svc_expkey_cache, net);
1287        cache_destroy_net(nn->svc_export_cache, net);
1288        svcauth_unix_purge(net);
1289
1290        dprintk("nfsd: export shutdown complete (net: %x).\n", net->ns.inum);
1291}
1292