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 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 = kzalloc(fsloc->locations_count
 408                        * sizeof(struct nfsd4_fs_location), GFP_KERNEL);
 409        if (!fsloc->locations)
 410                return -ENOMEM;
 411        for (i=0; i < fsloc->locations_count; i++) {
 412                /* colon separated host list */
 413                err = -EINVAL;
 414                len = qword_get(mesg, buf, PAGE_SIZE);
 415                if (len <= 0)
 416                        goto out_free_all;
 417                err = -ENOMEM;
 418                fsloc->locations[i].hosts = kstrdup(buf, GFP_KERNEL);
 419                if (!fsloc->locations[i].hosts)
 420                        goto out_free_all;
 421                err = -EINVAL;
 422                /* slash separated path component list */
 423                len = qword_get(mesg, buf, PAGE_SIZE);
 424                if (len <= 0)
 425                        goto out_free_all;
 426                err = -ENOMEM;
 427                fsloc->locations[i].path = kstrdup(buf, GFP_KERNEL);
 428                if (!fsloc->locations[i].path)
 429                        goto out_free_all;
 430        }
 431        /* migrated */
 432        err = get_int(mesg, &migrated);
 433        if (err)
 434                goto out_free_all;
 435        err = -EINVAL;
 436        if (migrated < 0 || migrated > 1)
 437                goto out_free_all;
 438        fsloc->migrated = migrated;
 439        return 0;
 440out_free_all:
 441        nfsd4_fslocs_free(fsloc);
 442        return err;
 443}
 444
 445static int secinfo_parse(char **mesg, char *buf, struct svc_export *exp)
 446{
 447        struct exp_flavor_info *f;
 448        u32 listsize;
 449        int err;
 450
 451        /* more than one secinfo */
 452        if (exp->ex_nflavors)
 453                return -EINVAL;
 454
 455        err = get_uint(mesg, &listsize);
 456        if (err)
 457                return err;
 458        if (listsize > MAX_SECINFO_LIST)
 459                return -EINVAL;
 460
 461        for (f = exp->ex_flavors; f < exp->ex_flavors + listsize; f++) {
 462                err = get_uint(mesg, &f->pseudoflavor);
 463                if (err)
 464                        return err;
 465                /*
 466                 * XXX: It would be nice to also check whether this
 467                 * pseudoflavor is supported, so we can discover the
 468                 * problem at export time instead of when a client fails
 469                 * to authenticate.
 470                 */
 471                err = get_uint(mesg, &f->flags);
 472                if (err)
 473                        return err;
 474                /* Only some flags are allowed to differ between flavors: */
 475                if (~NFSEXP_SECINFO_FLAGS & (f->flags ^ exp->ex_flags))
 476                        return -EINVAL;
 477        }
 478        exp->ex_nflavors = listsize;
 479        return 0;
 480}
 481
 482#else /* CONFIG_NFSD_V4 */
 483static inline int
 484fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc){return 0;}
 485static inline int
 486secinfo_parse(char **mesg, char *buf, struct svc_export *exp) { return 0; }
 487#endif
 488
 489static inline int
 490nfsd_uuid_parse(char **mesg, char *buf, unsigned char **puuid)
 491{
 492        int len;
 493
 494        /* more than one uuid */
 495        if (*puuid)
 496                return -EINVAL;
 497
 498        /* expect a 16 byte uuid encoded as \xXXXX... */
 499        len = qword_get(mesg, buf, PAGE_SIZE);
 500        if (len != EX_UUID_LEN)
 501                return -EINVAL;
 502
 503        *puuid = kmemdup(buf, EX_UUID_LEN, GFP_KERNEL);
 504        if (*puuid == NULL)
 505                return -ENOMEM;
 506
 507        return 0;
 508}
 509
 510static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
 511{
 512        /* client path expiry [flags anonuid anongid fsid] */
 513        char *buf;
 514        int len;
 515        int err;
 516        struct auth_domain *dom = NULL;
 517        struct svc_export exp = {}, *expp;
 518        int an_int;
 519
 520        if (mesg[mlen-1] != '\n')
 521                return -EINVAL;
 522        mesg[mlen-1] = 0;
 523
 524        buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 525        if (!buf)
 526                return -ENOMEM;
 527
 528        /* client */
 529        err = -EINVAL;
 530        len = qword_get(&mesg, buf, PAGE_SIZE);
 531        if (len <= 0)
 532                goto out;
 533
 534        err = -ENOENT;
 535        dom = auth_domain_find(buf);
 536        if (!dom)
 537                goto out;
 538
 539        /* path */
 540        err = -EINVAL;
 541        if ((len = qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 542                goto out1;
 543
 544        err = kern_path(buf, 0, &exp.ex_path);
 545        if (err)
 546                goto out1;
 547
 548        exp.ex_client = dom;
 549        exp.cd = cd;
 550        exp.ex_devid_map = NULL;
 551
 552        /* expiry */
 553        err = -EINVAL;
 554        exp.h.expiry_time = get_expiry(&mesg);
 555        if (exp.h.expiry_time == 0)
 556                goto out3;
 557
 558        /* flags */
 559        err = get_int(&mesg, &an_int);
 560        if (err == -ENOENT) {
 561                err = 0;
 562                set_bit(CACHE_NEGATIVE, &exp.h.flags);
 563        } else {
 564                if (err || an_int < 0)
 565                        goto out3;
 566                exp.ex_flags= an_int;
 567        
 568                /* anon uid */
 569                err = get_int(&mesg, &an_int);
 570                if (err)
 571                        goto out3;
 572                exp.ex_anon_uid= make_kuid(&init_user_ns, an_int);
 573
 574                /* anon gid */
 575                err = get_int(&mesg, &an_int);
 576                if (err)
 577                        goto out3;
 578                exp.ex_anon_gid= make_kgid(&init_user_ns, an_int);
 579
 580                /* fsid */
 581                err = get_int(&mesg, &an_int);
 582                if (err)
 583                        goto out3;
 584                exp.ex_fsid = an_int;
 585
 586                while ((len = qword_get(&mesg, buf, PAGE_SIZE)) > 0) {
 587                        if (strcmp(buf, "fsloc") == 0)
 588                                err = fsloc_parse(&mesg, buf, &exp.ex_fslocs);
 589                        else if (strcmp(buf, "uuid") == 0)
 590                                err = nfsd_uuid_parse(&mesg, buf, &exp.ex_uuid);
 591                        else if (strcmp(buf, "secinfo") == 0)
 592                                err = secinfo_parse(&mesg, buf, &exp);
 593                        else
 594                                /* quietly ignore unknown words and anything
 595                                 * following. Newer user-space can try to set
 596                                 * new values, then see what the result was.
 597                                 */
 598                                break;
 599                        if (err)
 600                                goto out4;
 601                }
 602
 603                err = check_export(d_inode(exp.ex_path.dentry), &exp.ex_flags,
 604                                   exp.ex_uuid);
 605                if (err)
 606                        goto out4;
 607                /*
 608                 * No point caching this if it would immediately expire.
 609                 * Also, this protects exportfs's dummy export from the
 610                 * anon_uid/anon_gid checks:
 611                 */
 612                if (exp.h.expiry_time < seconds_since_boot())
 613                        goto out4;
 614                /*
 615                 * For some reason exportfs has been passing down an
 616                 * invalid (-1) uid & gid on the "dummy" export which it
 617                 * uses to test export support.  To make sure exportfs
 618                 * sees errors from check_export we therefore need to
 619                 * delay these checks till after check_export:
 620                 */
 621                err = -EINVAL;
 622                if (!uid_valid(exp.ex_anon_uid))
 623                        goto out4;
 624                if (!gid_valid(exp.ex_anon_gid))
 625                        goto out4;
 626                err = 0;
 627
 628                nfsd4_setup_layout_type(&exp);
 629        }
 630
 631        expp = svc_export_lookup(&exp);
 632        if (expp)
 633                expp = svc_export_update(&exp, expp);
 634        else
 635                err = -ENOMEM;
 636        cache_flush();
 637        if (expp == NULL)
 638                err = -ENOMEM;
 639        else
 640                exp_put(expp);
 641out4:
 642        nfsd4_fslocs_free(&exp.ex_fslocs);
 643        kfree(exp.ex_uuid);
 644out3:
 645        path_put(&exp.ex_path);
 646out1:
 647        auth_domain_put(dom);
 648out:
 649        kfree(buf);
 650        return err;
 651}
 652
 653static void exp_flags(struct seq_file *m, int flag, int fsid,
 654                kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fslocs);
 655static void show_secinfo(struct seq_file *m, struct svc_export *exp);
 656
 657static int svc_export_show(struct seq_file *m,
 658                           struct cache_detail *cd,
 659                           struct cache_head *h)
 660{
 661        struct svc_export *exp ;
 662
 663        if (h ==NULL) {
 664                seq_puts(m, "#path domain(flags)\n");
 665                return 0;
 666        }
 667        exp = container_of(h, struct svc_export, h);
 668        seq_path(m, &exp->ex_path, " \t\n\\");
 669        seq_putc(m, '\t');
 670        seq_escape(m, exp->ex_client->name, " \t\n\\");
 671        seq_putc(m, '(');
 672        if (test_bit(CACHE_VALID, &h->flags) && 
 673            !test_bit(CACHE_NEGATIVE, &h->flags)) {
 674                exp_flags(m, exp->ex_flags, exp->ex_fsid,
 675                          exp->ex_anon_uid, exp->ex_anon_gid, &exp->ex_fslocs);
 676                if (exp->ex_uuid) {
 677                        int i;
 678                        seq_puts(m, ",uuid=");
 679                        for (i = 0; i < EX_UUID_LEN; i++) {
 680                                if ((i&3) == 0 && i)
 681                                        seq_putc(m, ':');
 682                                seq_printf(m, "%02x", exp->ex_uuid[i]);
 683                        }
 684                }
 685                show_secinfo(m, exp);
 686        }
 687        seq_puts(m, ")\n");
 688        return 0;
 689}
 690static int svc_export_match(struct cache_head *a, struct cache_head *b)
 691{
 692        struct svc_export *orig = container_of(a, struct svc_export, h);
 693        struct svc_export *new = container_of(b, struct svc_export, h);
 694        return orig->ex_client == new->ex_client &&
 695                path_equal(&orig->ex_path, &new->ex_path);
 696}
 697
 698static void svc_export_init(struct cache_head *cnew, struct cache_head *citem)
 699{
 700        struct svc_export *new = container_of(cnew, struct svc_export, h);
 701        struct svc_export *item = container_of(citem, struct svc_export, h);
 702
 703        kref_get(&item->ex_client->ref);
 704        new->ex_client = item->ex_client;
 705        new->ex_path = item->ex_path;
 706        path_get(&item->ex_path);
 707        new->ex_fslocs.locations = NULL;
 708        new->ex_fslocs.locations_count = 0;
 709        new->ex_fslocs.migrated = 0;
 710        new->ex_layout_types = 0;
 711        new->ex_uuid = NULL;
 712        new->cd = item->cd;
 713}
 714
 715static void export_update(struct cache_head *cnew, struct cache_head *citem)
 716{
 717        struct svc_export *new = container_of(cnew, struct svc_export, h);
 718        struct svc_export *item = container_of(citem, struct svc_export, h);
 719        int i;
 720
 721        new->ex_flags = item->ex_flags;
 722        new->ex_anon_uid = item->ex_anon_uid;
 723        new->ex_anon_gid = item->ex_anon_gid;
 724        new->ex_fsid = item->ex_fsid;
 725        new->ex_devid_map = item->ex_devid_map;
 726        item->ex_devid_map = NULL;
 727        new->ex_uuid = item->ex_uuid;
 728        item->ex_uuid = NULL;
 729        new->ex_fslocs.locations = item->ex_fslocs.locations;
 730        item->ex_fslocs.locations = NULL;
 731        new->ex_fslocs.locations_count = item->ex_fslocs.locations_count;
 732        item->ex_fslocs.locations_count = 0;
 733        new->ex_fslocs.migrated = item->ex_fslocs.migrated;
 734        item->ex_fslocs.migrated = 0;
 735        new->ex_layout_types = item->ex_layout_types;
 736        new->ex_nflavors = item->ex_nflavors;
 737        for (i = 0; i < MAX_SECINFO_LIST; i++) {
 738                new->ex_flavors[i] = item->ex_flavors[i];
 739        }
 740}
 741
 742static struct cache_head *svc_export_alloc(void)
 743{
 744        struct svc_export *i = kmalloc(sizeof(*i), GFP_KERNEL);
 745        if (i)
 746                return &i->h;
 747        else
 748                return NULL;
 749}
 750
 751static struct cache_detail svc_export_cache_template = {
 752        .owner          = THIS_MODULE,
 753        .hash_size      = EXPORT_HASHMAX,
 754        .name           = "nfsd.export",
 755        .cache_put      = svc_export_put,
 756        .cache_request  = svc_export_request,
 757        .cache_parse    = svc_export_parse,
 758        .cache_show     = svc_export_show,
 759        .match          = svc_export_match,
 760        .init           = svc_export_init,
 761        .update         = export_update,
 762        .alloc          = svc_export_alloc,
 763};
 764
 765static int
 766svc_export_hash(struct svc_export *exp)
 767{
 768        int hash;
 769
 770        hash = hash_ptr(exp->ex_client, EXPORT_HASHBITS);
 771        hash ^= hash_ptr(exp->ex_path.dentry, EXPORT_HASHBITS);
 772        hash ^= hash_ptr(exp->ex_path.mnt, EXPORT_HASHBITS);
 773        return hash;
 774}
 775
 776static struct svc_export *
 777svc_export_lookup(struct svc_export *exp)
 778{
 779        struct cache_head *ch;
 780        int hash = svc_export_hash(exp);
 781
 782        ch = sunrpc_cache_lookup(exp->cd, &exp->h, hash);
 783        if (ch)
 784                return container_of(ch, struct svc_export, h);
 785        else
 786                return NULL;
 787}
 788
 789static struct svc_export *
 790svc_export_update(struct svc_export *new, struct svc_export *old)
 791{
 792        struct cache_head *ch;
 793        int hash = svc_export_hash(old);
 794
 795        ch = sunrpc_cache_update(old->cd, &new->h, &old->h, hash);
 796        if (ch)
 797                return container_of(ch, struct svc_export, h);
 798        else
 799                return NULL;
 800}
 801
 802
 803static struct svc_expkey *
 804exp_find_key(struct cache_detail *cd, struct auth_domain *clp, int fsid_type,
 805             u32 *fsidv, struct cache_req *reqp)
 806{
 807        struct svc_expkey key, *ek;
 808        int err;
 809        
 810        if (!clp)
 811                return ERR_PTR(-ENOENT);
 812
 813        key.ek_client = clp;
 814        key.ek_fsidtype = fsid_type;
 815        memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
 816
 817        ek = svc_expkey_lookup(cd, &key);
 818        if (ek == NULL)
 819                return ERR_PTR(-ENOMEM);
 820        err = cache_check(cd, &ek->h, reqp);
 821        if (err)
 822                return ERR_PTR(err);
 823        return ek;
 824}
 825
 826static struct svc_export *
 827exp_get_by_name(struct cache_detail *cd, struct auth_domain *clp,
 828                const struct path *path, struct cache_req *reqp)
 829{
 830        struct svc_export *exp, key;
 831        int err;
 832
 833        if (!clp)
 834                return ERR_PTR(-ENOENT);
 835
 836        key.ex_client = clp;
 837        key.ex_path = *path;
 838        key.cd = cd;
 839
 840        exp = svc_export_lookup(&key);
 841        if (exp == NULL)
 842                return ERR_PTR(-ENOMEM);
 843        err = cache_check(cd, &exp->h, reqp);
 844        if (err)
 845                return ERR_PTR(err);
 846        return exp;
 847}
 848
 849/*
 850 * Find the export entry for a given dentry.
 851 */
 852static struct svc_export *
 853exp_parent(struct cache_detail *cd, struct auth_domain *clp, struct path *path)
 854{
 855        struct dentry *saved = dget(path->dentry);
 856        struct svc_export *exp = exp_get_by_name(cd, clp, path, NULL);
 857
 858        while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
 859                struct dentry *parent = dget_parent(path->dentry);
 860                dput(path->dentry);
 861                path->dentry = parent;
 862                exp = exp_get_by_name(cd, clp, path, NULL);
 863        }
 864        dput(path->dentry);
 865        path->dentry = saved;
 866        return exp;
 867}
 868
 869
 870
 871/*
 872 * Obtain the root fh on behalf of a client.
 873 * This could be done in user space, but I feel that it adds some safety
 874 * since its harder to fool a kernel module than a user space program.
 875 */
 876int
 877exp_rootfh(struct net *net, struct auth_domain *clp, char *name,
 878           struct knfsd_fh *f, int maxsize)
 879{
 880        struct svc_export       *exp;
 881        struct path             path;
 882        struct inode            *inode;
 883        struct svc_fh           fh;
 884        int                     err;
 885        struct nfsd_net         *nn = net_generic(net, nfsd_net_id);
 886        struct cache_detail     *cd = nn->svc_export_cache;
 887
 888        err = -EPERM;
 889        /* NB: we probably ought to check that it's NUL-terminated */
 890        if (kern_path(name, 0, &path)) {
 891                printk("nfsd: exp_rootfh path not found %s", name);
 892                return err;
 893        }
 894        inode = d_inode(path.dentry);
 895
 896        dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
 897                 name, path.dentry, clp->name,
 898                 inode->i_sb->s_id, inode->i_ino);
 899        exp = exp_parent(cd, clp, &path);
 900        if (IS_ERR(exp)) {
 901                err = PTR_ERR(exp);
 902                goto out;
 903        }
 904
 905        /*
 906         * fh must be initialized before calling fh_compose
 907         */
 908        fh_init(&fh, maxsize);
 909        if (fh_compose(&fh, exp, path.dentry, NULL))
 910                err = -EINVAL;
 911        else
 912                err = 0;
 913        memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
 914        fh_put(&fh);
 915        exp_put(exp);
 916out:
 917        path_put(&path);
 918        return err;
 919}
 920
 921static struct svc_export *exp_find(struct cache_detail *cd,
 922                                   struct auth_domain *clp, int fsid_type,
 923                                   u32 *fsidv, struct cache_req *reqp)
 924{
 925        struct svc_export *exp;
 926        struct nfsd_net *nn = net_generic(cd->net, nfsd_net_id);
 927        struct svc_expkey *ek = exp_find_key(nn->svc_expkey_cache, clp, fsid_type, fsidv, reqp);
 928        if (IS_ERR(ek))
 929                return ERR_CAST(ek);
 930
 931        exp = exp_get_by_name(cd, clp, &ek->ek_path, reqp);
 932        cache_put(&ek->h, nn->svc_expkey_cache);
 933
 934        if (IS_ERR(exp))
 935                return ERR_CAST(exp);
 936        return exp;
 937}
 938
 939__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp)
 940{
 941        struct exp_flavor_info *f;
 942        struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
 943
 944        /* legacy gss-only clients are always OK: */
 945        if (exp->ex_client == rqstp->rq_gssclient)
 946                return 0;
 947        /* ip-address based client; check sec= export option: */
 948        for (f = exp->ex_flavors; f < end; f++) {
 949                if (f->pseudoflavor == rqstp->rq_cred.cr_flavor)
 950                        return 0;
 951        }
 952        /* defaults in absence of sec= options: */
 953        if (exp->ex_nflavors == 0) {
 954                if (rqstp->rq_cred.cr_flavor == RPC_AUTH_NULL ||
 955                    rqstp->rq_cred.cr_flavor == RPC_AUTH_UNIX)
 956                        return 0;
 957        }
 958
 959        /* If the compound op contains a spo_must_allowed op,
 960         * it will be sent with integrity/protection which
 961         * will have to be expressly allowed on mounts that
 962         * don't support it
 963         */
 964
 965        if (nfsd4_spo_must_allow(rqstp))
 966                return 0;
 967
 968        return nfserr_wrongsec;
 969}
 970
 971/*
 972 * Uses rq_client and rq_gssclient to find an export; uses rq_client (an
 973 * auth_unix client) if it's available and has secinfo information;
 974 * otherwise, will try to use rq_gssclient.
 975 *
 976 * Called from functions that handle requests; functions that do work on
 977 * behalf of mountd are passed a single client name to use, and should
 978 * use exp_get_by_name() or exp_find().
 979 */
 980struct svc_export *
 981rqst_exp_get_by_name(struct svc_rqst *rqstp, struct path *path)
 982{
 983        struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
 984        struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 985        struct cache_detail *cd = nn->svc_export_cache;
 986
 987        if (rqstp->rq_client == NULL)
 988                goto gss;
 989
 990        /* First try the auth_unix client: */
 991        exp = exp_get_by_name(cd, rqstp->rq_client, path, &rqstp->rq_chandle);
 992        if (PTR_ERR(exp) == -ENOENT)
 993                goto gss;
 994        if (IS_ERR(exp))
 995                return exp;
 996        /* If it has secinfo, assume there are no gss/... clients */
 997        if (exp->ex_nflavors > 0)
 998                return exp;
 999gss:
1000        /* Otherwise, try falling back on gss client */
1001        if (rqstp->rq_gssclient == NULL)
1002                return exp;
1003        gssexp = exp_get_by_name(cd, rqstp->rq_gssclient, path, &rqstp->rq_chandle);
1004        if (PTR_ERR(gssexp) == -ENOENT)
1005                return exp;
1006        if (!IS_ERR(exp))
1007                exp_put(exp);
1008        return gssexp;
1009}
1010
1011struct svc_export *
1012rqst_exp_find(struct svc_rqst *rqstp, int fsid_type, u32 *fsidv)
1013{
1014        struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
1015        struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1016        struct cache_detail *cd = nn->svc_export_cache;
1017
1018        if (rqstp->rq_client == NULL)
1019                goto gss;
1020
1021        /* First try the auth_unix client: */
1022        exp = exp_find(cd, rqstp->rq_client, fsid_type,
1023                       fsidv, &rqstp->rq_chandle);
1024        if (PTR_ERR(exp) == -ENOENT)
1025                goto gss;
1026        if (IS_ERR(exp))
1027                return exp;
1028        /* If it has secinfo, assume there are no gss/... clients */
1029        if (exp->ex_nflavors > 0)
1030                return exp;
1031gss:
1032        /* Otherwise, try falling back on gss client */
1033        if (rqstp->rq_gssclient == NULL)
1034                return exp;
1035        gssexp = exp_find(cd, rqstp->rq_gssclient, fsid_type, fsidv,
1036                                                &rqstp->rq_chandle);
1037        if (PTR_ERR(gssexp) == -ENOENT)
1038                return exp;
1039        if (!IS_ERR(exp))
1040                exp_put(exp);
1041        return gssexp;
1042}
1043
1044struct svc_export *
1045rqst_exp_parent(struct svc_rqst *rqstp, struct path *path)
1046{
1047        struct dentry *saved = dget(path->dentry);
1048        struct svc_export *exp = rqst_exp_get_by_name(rqstp, path);
1049
1050        while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
1051                struct dentry *parent = dget_parent(path->dentry);
1052                dput(path->dentry);
1053                path->dentry = parent;
1054                exp = rqst_exp_get_by_name(rqstp, path);
1055        }
1056        dput(path->dentry);
1057        path->dentry = saved;
1058        return exp;
1059}
1060
1061struct svc_export *rqst_find_fsidzero_export(struct svc_rqst *rqstp)
1062{
1063        u32 fsidv[2];
1064
1065        mk_fsid(FSID_NUM, fsidv, 0, 0, 0, NULL);
1066
1067        return rqst_exp_find(rqstp, FSID_NUM, fsidv);
1068}
1069
1070/*
1071 * Called when we need the filehandle for the root of the pseudofs,
1072 * for a given NFSv4 client.   The root is defined to be the
1073 * export point with fsid==0
1074 */
1075__be32
1076exp_pseudoroot(struct svc_rqst *rqstp, struct svc_fh *fhp)
1077{
1078        struct svc_export *exp;
1079        __be32 rv;
1080
1081        exp = rqst_find_fsidzero_export(rqstp);
1082        if (IS_ERR(exp))
1083                return nfserrno(PTR_ERR(exp));
1084        rv = fh_compose(fhp, exp, exp->ex_path.dentry, NULL);
1085        exp_put(exp);
1086        return rv;
1087}
1088
1089static struct flags {
1090        int flag;
1091        char *name[2];
1092} expflags[] = {
1093        { NFSEXP_READONLY, {"ro", "rw"}},
1094        { NFSEXP_INSECURE_PORT, {"insecure", ""}},
1095        { NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
1096        { NFSEXP_ALLSQUASH, {"all_squash", ""}},
1097        { NFSEXP_ASYNC, {"async", "sync"}},
1098        { NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
1099        { NFSEXP_NOREADDIRPLUS, {"nordirplus", ""}},
1100        { NFSEXP_NOHIDE, {"nohide", ""}},
1101        { NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
1102        { NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
1103        { NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
1104        { NFSEXP_V4ROOT, {"v4root", ""}},
1105        { NFSEXP_PNFS, {"pnfs", ""}},
1106        { NFSEXP_SECURITY_LABEL, {"security_label", ""}},
1107        { 0, {"", ""}}
1108};
1109
1110static void show_expflags(struct seq_file *m, int flags, int mask)
1111{
1112        struct flags *flg;
1113        int state, first = 0;
1114
1115        for (flg = expflags; flg->flag; flg++) {
1116                if (flg->flag & ~mask)
1117                        continue;
1118                state = (flg->flag & flags) ? 0 : 1;
1119                if (*flg->name[state])
1120                        seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
1121        }
1122}
1123
1124static void show_secinfo_flags(struct seq_file *m, int flags)
1125{
1126        seq_printf(m, ",");
1127        show_expflags(m, flags, NFSEXP_SECINFO_FLAGS);
1128}
1129
1130static bool secinfo_flags_equal(int f, int g)
1131{
1132        f &= NFSEXP_SECINFO_FLAGS;
1133        g &= NFSEXP_SECINFO_FLAGS;
1134        return f == g;
1135}
1136
1137static int show_secinfo_run(struct seq_file *m, struct exp_flavor_info **fp, struct exp_flavor_info *end)
1138{
1139        int flags;
1140
1141        flags = (*fp)->flags;
1142        seq_printf(m, ",sec=%d", (*fp)->pseudoflavor);
1143        (*fp)++;
1144        while (*fp != end && secinfo_flags_equal(flags, (*fp)->flags)) {
1145                seq_printf(m, ":%d", (*fp)->pseudoflavor);
1146                (*fp)++;
1147        }
1148        return flags;
1149}
1150
1151static void show_secinfo(struct seq_file *m, struct svc_export *exp)
1152{
1153        struct exp_flavor_info *f;
1154        struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
1155        int flags;
1156
1157        if (exp->ex_nflavors == 0)
1158                return;
1159        f = exp->ex_flavors;
1160        flags = show_secinfo_run(m, &f, end);
1161        if (!secinfo_flags_equal(flags, exp->ex_flags))
1162                show_secinfo_flags(m, flags);
1163        while (f != end) {
1164                flags = show_secinfo_run(m, &f, end);
1165                show_secinfo_flags(m, flags);
1166        }
1167}
1168
1169static void exp_flags(struct seq_file *m, int flag, int fsid,
1170                kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fsloc)
1171{
1172        show_expflags(m, flag, NFSEXP_ALLFLAGS);
1173        if (flag & NFSEXP_FSID)
1174                seq_printf(m, ",fsid=%d", fsid);
1175        if (!uid_eq(anonu, make_kuid(&init_user_ns, (uid_t)-2)) &&
1176            !uid_eq(anonu, make_kuid(&init_user_ns, 0x10000-2)))
1177                seq_printf(m, ",anonuid=%u", from_kuid(&init_user_ns, anonu));
1178        if (!gid_eq(anong, make_kgid(&init_user_ns, (gid_t)-2)) &&
1179            !gid_eq(anong, make_kgid(&init_user_ns, 0x10000-2)))
1180                seq_printf(m, ",anongid=%u", from_kgid(&init_user_ns, anong));
1181        if (fsloc && fsloc->locations_count > 0) {
1182                char *loctype = (fsloc->migrated) ? "refer" : "replicas";
1183                int i;
1184
1185                seq_printf(m, ",%s=", loctype);
1186                seq_escape(m, fsloc->locations[0].path, ",;@ \t\n\\");
1187                seq_putc(m, '@');
1188                seq_escape(m, fsloc->locations[0].hosts, ",;@ \t\n\\");
1189                for (i = 1; i < fsloc->locations_count; i++) {
1190                        seq_putc(m, ';');
1191                        seq_escape(m, fsloc->locations[i].path, ",;@ \t\n\\");
1192                        seq_putc(m, '@');
1193                        seq_escape(m, fsloc->locations[i].hosts, ",;@ \t\n\\");
1194                }
1195        }
1196}
1197
1198static int e_show(struct seq_file *m, void *p)
1199{
1200        struct cache_head *cp = p;
1201        struct svc_export *exp = container_of(cp, struct svc_export, h);
1202        struct cache_detail *cd = m->private;
1203
1204        if (p == SEQ_START_TOKEN) {
1205                seq_puts(m, "# Version 1.1\n");
1206                seq_puts(m, "# Path Client(Flags) # IPs\n");
1207                return 0;
1208        }
1209
1210        exp_get(exp);
1211        if (cache_check(cd, &exp->h, NULL))
1212                return 0;
1213        exp_put(exp);
1214        return svc_export_show(m, cd, cp);
1215}
1216
1217const struct seq_operations nfs_exports_op = {
1218        .start  = cache_seq_start,
1219        .next   = cache_seq_next,
1220        .stop   = cache_seq_stop,
1221        .show   = e_show,
1222};
1223
1224/*
1225 * Initialize the exports module.
1226 */
1227int
1228nfsd_export_init(struct net *net)
1229{
1230        int rv;
1231        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1232
1233        dprintk("nfsd: initializing export module (net: %p).\n", net);
1234
1235        nn->svc_export_cache = cache_create_net(&svc_export_cache_template, net);
1236        if (IS_ERR(nn->svc_export_cache))
1237                return PTR_ERR(nn->svc_export_cache);
1238        rv = cache_register_net(nn->svc_export_cache, net);
1239        if (rv)
1240                goto destroy_export_cache;
1241
1242        nn->svc_expkey_cache = cache_create_net(&svc_expkey_cache_template, net);
1243        if (IS_ERR(nn->svc_expkey_cache)) {
1244                rv = PTR_ERR(nn->svc_expkey_cache);
1245                goto unregister_export_cache;
1246        }
1247        rv = cache_register_net(nn->svc_expkey_cache, net);
1248        if (rv)
1249                goto destroy_expkey_cache;
1250        return 0;
1251
1252destroy_expkey_cache:
1253        cache_destroy_net(nn->svc_expkey_cache, net);
1254unregister_export_cache:
1255        cache_unregister_net(nn->svc_export_cache, net);
1256destroy_export_cache:
1257        cache_destroy_net(nn->svc_export_cache, net);
1258        return rv;
1259}
1260
1261/*
1262 * Flush exports table - called when last nfsd thread is killed
1263 */
1264void
1265nfsd_export_flush(struct net *net)
1266{
1267        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1268
1269        cache_purge(nn->svc_expkey_cache);
1270        cache_purge(nn->svc_export_cache);
1271}
1272
1273/*
1274 * Shutdown the exports module.
1275 */
1276void
1277nfsd_export_shutdown(struct net *net)
1278{
1279        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1280
1281        dprintk("nfsd: shutting down export module (net: %p).\n", net);
1282
1283        cache_unregister_net(nn->svc_expkey_cache, net);
1284        cache_unregister_net(nn->svc_export_cache, net);
1285        cache_destroy_net(nn->svc_expkey_cache, net);
1286        cache_destroy_net(nn->svc_export_cache, net);
1287        svcauth_unix_purge(net);
1288
1289        dprintk("nfsd: export shutdown complete (net: %p).\n", net);
1290}
1291