linux/fs/nfsd/export.c
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   1/*
   2 * NFS exporting and validation.
   3 *
   4 * We maintain a list of clients, each of which has a list of
   5 * exports. To export an fs to a given client, you first have
   6 * to create the client entry with NFSCTL_ADDCLIENT, which
   7 * creates a client control block and adds it to the hash
   8 * table. Then, you call NFSCTL_EXPORT for each fs.
   9 *
  10 *
  11 * Copyright (C) 1995, 1996 Olaf Kirch, <okir@monad.swb.de>
  12 */
  13
  14#include <linux/slab.h>
  15#include <linux/namei.h>
  16#include <linux/module.h>
  17#include <linux/exportfs.h>
  18#include <linux/sunrpc/svc_xprt.h>
  19
  20#include <net/ipv6.h>
  21
  22#include "nfsd.h"
  23#include "nfsfh.h"
  24#include "netns.h"
  25
  26#define NFSDDBG_FACILITY        NFSDDBG_EXPORT
  27
  28typedef struct auth_domain      svc_client;
  29typedef struct svc_export       svc_export;
  30
  31/*
  32 * We have two caches.
  33 * One maps client+vfsmnt+dentry to export options - the export map
  34 * The other maps client+filehandle-fragment to export options. - the expkey map
  35 *
  36 * The export options are actually stored in the first map, and the
  37 * second map contains a reference to the entry in the first map.
  38 */
  39
  40#define EXPKEY_HASHBITS         8
  41#define EXPKEY_HASHMAX          (1 << EXPKEY_HASHBITS)
  42#define EXPKEY_HASHMASK         (EXPKEY_HASHMAX -1)
  43
  44static void expkey_put(struct kref *ref)
  45{
  46        struct svc_expkey *key = container_of(ref, struct svc_expkey, h.ref);
  47
  48        if (test_bit(CACHE_VALID, &key->h.flags) &&
  49            !test_bit(CACHE_NEGATIVE, &key->h.flags))
  50                path_put(&key->ek_path);
  51        auth_domain_put(key->ek_client);
  52        kfree(key);
  53}
  54
  55static void expkey_request(struct cache_detail *cd,
  56                           struct cache_head *h,
  57                           char **bpp, int *blen)
  58{
  59        /* client fsidtype \xfsid */
  60        struct svc_expkey *ek = container_of(h, struct svc_expkey, h);
  61        char type[5];
  62
  63        qword_add(bpp, blen, ek->ek_client->name);
  64        snprintf(type, 5, "%d", ek->ek_fsidtype);
  65        qword_add(bpp, blen, type);
  66        qword_addhex(bpp, blen, (char*)ek->ek_fsid, key_len(ek->ek_fsidtype));
  67        (*bpp)[-1] = '\n';
  68}
  69
  70static int expkey_upcall(struct cache_detail *cd, struct cache_head *h)
  71{
  72        return sunrpc_cache_pipe_upcall(cd, h, expkey_request);
  73}
  74
  75static struct svc_expkey *svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
  76                                            struct svc_expkey *old);
  77static struct svc_expkey *svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *);
  78
  79static int expkey_parse(struct cache_detail *cd, char *mesg, int mlen)
  80{
  81        /* client fsidtype fsid [path] */
  82        char *buf;
  83        int len;
  84        struct auth_domain *dom = NULL;
  85        int err;
  86        int fsidtype;
  87        char *ep;
  88        struct svc_expkey key;
  89        struct svc_expkey *ek = NULL;
  90
  91        if (mesg[mlen - 1] != '\n')
  92                return -EINVAL;
  93        mesg[mlen-1] = 0;
  94
  95        buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
  96        err = -ENOMEM;
  97        if (!buf)
  98                goto out;
  99
 100        err = -EINVAL;
 101        if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 102                goto out;
 103
 104        err = -ENOENT;
 105        dom = auth_domain_find(buf);
 106        if (!dom)
 107                goto out;
 108        dprintk("found domain %s\n", buf);
 109
 110        err = -EINVAL;
 111        if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 112                goto out;
 113        fsidtype = simple_strtoul(buf, &ep, 10);
 114        if (*ep)
 115                goto out;
 116        dprintk("found fsidtype %d\n", fsidtype);
 117        if (key_len(fsidtype)==0) /* invalid type */
 118                goto out;
 119        if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 120                goto out;
 121        dprintk("found fsid length %d\n", len);
 122        if (len != key_len(fsidtype))
 123                goto out;
 124
 125        /* OK, we seem to have a valid key */
 126        key.h.flags = 0;
 127        key.h.expiry_time = get_expiry(&mesg);
 128        if (key.h.expiry_time == 0)
 129                goto out;
 130
 131        key.ek_client = dom;    
 132        key.ek_fsidtype = fsidtype;
 133        memcpy(key.ek_fsid, buf, len);
 134
 135        ek = svc_expkey_lookup(cd, &key);
 136        err = -ENOMEM;
 137        if (!ek)
 138                goto out;
 139
 140        /* now we want a pathname, or empty meaning NEGATIVE  */
 141        err = -EINVAL;
 142        len = qword_get(&mesg, buf, PAGE_SIZE);
 143        if (len < 0)
 144                goto out;
 145        dprintk("Path seems to be <%s>\n", buf);
 146        err = 0;
 147        if (len == 0) {
 148                set_bit(CACHE_NEGATIVE, &key.h.flags);
 149                ek = svc_expkey_update(cd, &key, ek);
 150                if (!ek)
 151                        err = -ENOMEM;
 152        } else {
 153                err = kern_path(buf, 0, &key.ek_path);
 154                if (err)
 155                        goto out;
 156
 157                dprintk("Found the path %s\n", buf);
 158
 159                ek = svc_expkey_update(cd, &key, ek);
 160                if (!ek)
 161                        err = -ENOMEM;
 162                path_put(&key.ek_path);
 163        }
 164        cache_flush();
 165 out:
 166        if (ek)
 167                cache_put(&ek->h, cd);
 168        if (dom)
 169                auth_domain_put(dom);
 170        kfree(buf);
 171        return err;
 172}
 173
 174static int expkey_show(struct seq_file *m,
 175                       struct cache_detail *cd,
 176                       struct cache_head *h)
 177{
 178        struct svc_expkey *ek ;
 179        int i;
 180
 181        if (h ==NULL) {
 182                seq_puts(m, "#domain fsidtype fsid [path]\n");
 183                return 0;
 184        }
 185        ek = container_of(h, struct svc_expkey, h);
 186        seq_printf(m, "%s %d 0x", ek->ek_client->name,
 187                   ek->ek_fsidtype);
 188        for (i=0; i < key_len(ek->ek_fsidtype)/4; i++)
 189                seq_printf(m, "%08x", ek->ek_fsid[i]);
 190        if (test_bit(CACHE_VALID, &h->flags) && 
 191            !test_bit(CACHE_NEGATIVE, &h->flags)) {
 192                seq_printf(m, " ");
 193                seq_path(m, &ek->ek_path, "\\ \t\n");
 194        }
 195        seq_printf(m, "\n");
 196        return 0;
 197}
 198
 199static inline int expkey_match (struct cache_head *a, struct cache_head *b)
 200{
 201        struct svc_expkey *orig = container_of(a, struct svc_expkey, h);
 202        struct svc_expkey *new = container_of(b, struct svc_expkey, h);
 203
 204        if (orig->ek_fsidtype != new->ek_fsidtype ||
 205            orig->ek_client != new->ek_client ||
 206            memcmp(orig->ek_fsid, new->ek_fsid, key_len(orig->ek_fsidtype)) != 0)
 207                return 0;
 208        return 1;
 209}
 210
 211static inline void expkey_init(struct cache_head *cnew,
 212                                   struct cache_head *citem)
 213{
 214        struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
 215        struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
 216
 217        kref_get(&item->ek_client->ref);
 218        new->ek_client = item->ek_client;
 219        new->ek_fsidtype = item->ek_fsidtype;
 220
 221        memcpy(new->ek_fsid, item->ek_fsid, sizeof(new->ek_fsid));
 222}
 223
 224static inline void expkey_update(struct cache_head *cnew,
 225                                   struct cache_head *citem)
 226{
 227        struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
 228        struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
 229
 230        new->ek_path = item->ek_path;
 231        path_get(&item->ek_path);
 232}
 233
 234static struct cache_head *expkey_alloc(void)
 235{
 236        struct svc_expkey *i = kmalloc(sizeof(*i), GFP_KERNEL);
 237        if (i)
 238                return &i->h;
 239        else
 240                return NULL;
 241}
 242
 243static struct cache_detail svc_expkey_cache_template = {
 244        .owner          = THIS_MODULE,
 245        .hash_size      = EXPKEY_HASHMAX,
 246        .name           = "nfsd.fh",
 247        .cache_put      = expkey_put,
 248        .cache_upcall   = expkey_upcall,
 249        .cache_parse    = expkey_parse,
 250        .cache_show     = expkey_show,
 251        .match          = expkey_match,
 252        .init           = expkey_init,
 253        .update         = expkey_update,
 254        .alloc          = expkey_alloc,
 255};
 256
 257static int
 258svc_expkey_hash(struct svc_expkey *item)
 259{
 260        int hash = item->ek_fsidtype;
 261        char * cp = (char*)item->ek_fsid;
 262        int len = key_len(item->ek_fsidtype);
 263
 264        hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
 265        hash ^= hash_ptr(item->ek_client, EXPKEY_HASHBITS);
 266        hash &= EXPKEY_HASHMASK;
 267        return hash;
 268}
 269
 270static struct svc_expkey *
 271svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *item)
 272{
 273        struct cache_head *ch;
 274        int hash = svc_expkey_hash(item);
 275
 276        ch = sunrpc_cache_lookup(cd, &item->h, hash);
 277        if (ch)
 278                return container_of(ch, struct svc_expkey, h);
 279        else
 280                return NULL;
 281}
 282
 283static struct svc_expkey *
 284svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
 285                  struct svc_expkey *old)
 286{
 287        struct cache_head *ch;
 288        int hash = svc_expkey_hash(new);
 289
 290        ch = sunrpc_cache_update(cd, &new->h, &old->h, hash);
 291        if (ch)
 292                return container_of(ch, struct svc_expkey, h);
 293        else
 294                return NULL;
 295}
 296
 297
 298#define EXPORT_HASHBITS         8
 299#define EXPORT_HASHMAX          (1<< EXPORT_HASHBITS)
 300
 301static void nfsd4_fslocs_free(struct nfsd4_fs_locations *fsloc)
 302{
 303        int i;
 304
 305        for (i = 0; i < fsloc->locations_count; i++) {
 306                kfree(fsloc->locations[i].path);
 307                kfree(fsloc->locations[i].hosts);
 308        }
 309        kfree(fsloc->locations);
 310}
 311
 312static void svc_export_put(struct kref *ref)
 313{
 314        struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
 315        path_put(&exp->ex_path);
 316        auth_domain_put(exp->ex_client);
 317        nfsd4_fslocs_free(&exp->ex_fslocs);
 318        kfree(exp);
 319}
 320
 321static void svc_export_request(struct cache_detail *cd,
 322                               struct cache_head *h,
 323                               char **bpp, int *blen)
 324{
 325        /*  client path */
 326        struct svc_export *exp = container_of(h, struct svc_export, h);
 327        char *pth;
 328
 329        qword_add(bpp, blen, exp->ex_client->name);
 330        pth = d_path(&exp->ex_path, *bpp, *blen);
 331        if (IS_ERR(pth)) {
 332                /* is this correct? */
 333                (*bpp)[0] = '\n';
 334                return;
 335        }
 336        qword_add(bpp, blen, pth);
 337        (*bpp)[-1] = '\n';
 338}
 339
 340static int svc_export_upcall(struct cache_detail *cd, struct cache_head *h)
 341{
 342        return sunrpc_cache_pipe_upcall(cd, h, svc_export_request);
 343}
 344
 345static struct svc_export *svc_export_update(struct svc_export *new,
 346                                            struct svc_export *old);
 347static struct svc_export *svc_export_lookup(struct svc_export *);
 348
 349static int check_export(struct inode *inode, int *flags, unsigned char *uuid)
 350{
 351
 352        /*
 353         * We currently export only dirs, regular files, and (for v4
 354         * pseudoroot) symlinks.
 355         */
 356        if (!S_ISDIR(inode->i_mode) &&
 357            !S_ISLNK(inode->i_mode) &&
 358            !S_ISREG(inode->i_mode))
 359                return -ENOTDIR;
 360
 361        /*
 362         * Mountd should never pass down a writeable V4ROOT export, but,
 363         * just to make sure:
 364         */
 365        if (*flags & NFSEXP_V4ROOT)
 366                *flags |= NFSEXP_READONLY;
 367
 368        /* There are two requirements on a filesystem to be exportable.
 369         * 1:  We must be able to identify the filesystem from a number.
 370         *       either a device number (so FS_REQUIRES_DEV needed)
 371         *       or an FSID number (so NFSEXP_FSID or ->uuid is needed).
 372         * 2:  We must be able to find an inode from a filehandle.
 373         *       This means that s_export_op must be set.
 374         */
 375        if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) &&
 376            !(*flags & NFSEXP_FSID) &&
 377            uuid == NULL) {
 378                dprintk("exp_export: export of non-dev fs without fsid\n");
 379                return -EINVAL;
 380        }
 381
 382        if (!inode->i_sb->s_export_op ||
 383            !inode->i_sb->s_export_op->fh_to_dentry) {
 384                dprintk("exp_export: export of invalid fs type.\n");
 385                return -EINVAL;
 386        }
 387
 388        return 0;
 389
 390}
 391
 392#ifdef CONFIG_NFSD_V4
 393
 394static int
 395fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc)
 396{
 397        int len;
 398        int migrated, i, err;
 399
 400        /* listsize */
 401        err = get_uint(mesg, &fsloc->locations_count);
 402        if (err)
 403                return err;
 404        if (fsloc->locations_count > MAX_FS_LOCATIONS)
 405                return -EINVAL;
 406        if (fsloc->locations_count == 0)
 407                return 0;
 408
 409        fsloc->locations = kzalloc(fsloc->locations_count
 410                        * sizeof(struct nfsd4_fs_location), GFP_KERNEL);
 411        if (!fsloc->locations)
 412                return -ENOMEM;
 413        for (i=0; i < fsloc->locations_count; i++) {
 414                /* colon separated host list */
 415                err = -EINVAL;
 416                len = qword_get(mesg, buf, PAGE_SIZE);
 417                if (len <= 0)
 418                        goto out_free_all;
 419                err = -ENOMEM;
 420                fsloc->locations[i].hosts = kstrdup(buf, GFP_KERNEL);
 421                if (!fsloc->locations[i].hosts)
 422                        goto out_free_all;
 423                err = -EINVAL;
 424                /* slash separated path component list */
 425                len = qword_get(mesg, buf, PAGE_SIZE);
 426                if (len <= 0)
 427                        goto out_free_all;
 428                err = -ENOMEM;
 429                fsloc->locations[i].path = kstrdup(buf, GFP_KERNEL);
 430                if (!fsloc->locations[i].path)
 431                        goto out_free_all;
 432        }
 433        /* migrated */
 434        err = get_int(mesg, &migrated);
 435        if (err)
 436                goto out_free_all;
 437        err = -EINVAL;
 438        if (migrated < 0 || migrated > 1)
 439                goto out_free_all;
 440        fsloc->migrated = migrated;
 441        return 0;
 442out_free_all:
 443        nfsd4_fslocs_free(fsloc);
 444        return err;
 445}
 446
 447static int secinfo_parse(char **mesg, char *buf, struct svc_export *exp)
 448{
 449        int listsize, err;
 450        struct exp_flavor_info *f;
 451
 452        err = get_int(mesg, &listsize);
 453        if (err)
 454                return err;
 455        if (listsize < 0 || listsize > MAX_SECINFO_LIST)
 456                return -EINVAL;
 457
 458        for (f = exp->ex_flavors; f < exp->ex_flavors + listsize; f++) {
 459                err = get_uint(mesg, &f->pseudoflavor);
 460                if (err)
 461                        return err;
 462                /*
 463                 * XXX: It would be nice to also check whether this
 464                 * pseudoflavor is supported, so we can discover the
 465                 * problem at export time instead of when a client fails
 466                 * to authenticate.
 467                 */
 468                err = get_uint(mesg, &f->flags);
 469                if (err)
 470                        return err;
 471                /* Only some flags are allowed to differ between flavors: */
 472                if (~NFSEXP_SECINFO_FLAGS & (f->flags ^ exp->ex_flags))
 473                        return -EINVAL;
 474        }
 475        exp->ex_nflavors = listsize;
 476        return 0;
 477}
 478
 479#else /* CONFIG_NFSD_V4 */
 480static inline int
 481fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc){return 0;}
 482static inline int
 483secinfo_parse(char **mesg, char *buf, struct svc_export *exp) { return 0; }
 484#endif
 485
 486static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
 487{
 488        /* client path expiry [flags anonuid anongid fsid] */
 489        char *buf;
 490        int len;
 491        int err;
 492        struct auth_domain *dom = NULL;
 493        struct svc_export exp = {}, *expp;
 494        int an_int;
 495
 496        if (mesg[mlen-1] != '\n')
 497                return -EINVAL;
 498        mesg[mlen-1] = 0;
 499
 500        buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 501        if (!buf)
 502                return -ENOMEM;
 503
 504        /* client */
 505        err = -EINVAL;
 506        len = qword_get(&mesg, buf, PAGE_SIZE);
 507        if (len <= 0)
 508                goto out;
 509
 510        err = -ENOENT;
 511        dom = auth_domain_find(buf);
 512        if (!dom)
 513                goto out;
 514
 515        /* path */
 516        err = -EINVAL;
 517        if ((len = qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
 518                goto out1;
 519
 520        err = kern_path(buf, 0, &exp.ex_path);
 521        if (err)
 522                goto out1;
 523
 524        exp.ex_client = dom;
 525        exp.cd = cd;
 526
 527        /* expiry */
 528        err = -EINVAL;
 529        exp.h.expiry_time = get_expiry(&mesg);
 530        if (exp.h.expiry_time == 0)
 531                goto out3;
 532
 533        /* flags */
 534        err = get_int(&mesg, &an_int);
 535        if (err == -ENOENT) {
 536                err = 0;
 537                set_bit(CACHE_NEGATIVE, &exp.h.flags);
 538        } else {
 539                if (err || an_int < 0)
 540                        goto out3;
 541                exp.ex_flags= an_int;
 542        
 543                /* anon uid */
 544                err = get_int(&mesg, &an_int);
 545                if (err)
 546                        goto out3;
 547                exp.ex_anon_uid= an_int;
 548
 549                /* anon gid */
 550                err = get_int(&mesg, &an_int);
 551                if (err)
 552                        goto out3;
 553                exp.ex_anon_gid= an_int;
 554
 555                /* fsid */
 556                err = get_int(&mesg, &an_int);
 557                if (err)
 558                        goto out3;
 559                exp.ex_fsid = an_int;
 560
 561                while ((len = qword_get(&mesg, buf, PAGE_SIZE)) > 0) {
 562                        if (strcmp(buf, "fsloc") == 0)
 563                                err = fsloc_parse(&mesg, buf, &exp.ex_fslocs);
 564                        else if (strcmp(buf, "uuid") == 0) {
 565                                /* expect a 16 byte uuid encoded as \xXXXX... */
 566                                len = qword_get(&mesg, buf, PAGE_SIZE);
 567                                if (len != 16)
 568                                        err  = -EINVAL;
 569                                else {
 570                                        exp.ex_uuid =
 571                                                kmemdup(buf, 16, GFP_KERNEL);
 572                                        if (exp.ex_uuid == NULL)
 573                                                err = -ENOMEM;
 574                                }
 575                        } else if (strcmp(buf, "secinfo") == 0)
 576                                err = secinfo_parse(&mesg, buf, &exp);
 577                        else
 578                                /* quietly ignore unknown words and anything
 579                                 * following. Newer user-space can try to set
 580                                 * new values, then see what the result was.
 581                                 */
 582                                break;
 583                        if (err)
 584                                goto out4;
 585                }
 586
 587                err = check_export(exp.ex_path.dentry->d_inode, &exp.ex_flags,
 588                                   exp.ex_uuid);
 589                if (err)
 590                        goto out4;
 591        }
 592
 593        expp = svc_export_lookup(&exp);
 594        if (expp)
 595                expp = svc_export_update(&exp, expp);
 596        else
 597                err = -ENOMEM;
 598        cache_flush();
 599        if (expp == NULL)
 600                err = -ENOMEM;
 601        else
 602                exp_put(expp);
 603out4:
 604        nfsd4_fslocs_free(&exp.ex_fslocs);
 605        kfree(exp.ex_uuid);
 606out3:
 607        path_put(&exp.ex_path);
 608out1:
 609        auth_domain_put(dom);
 610out:
 611        kfree(buf);
 612        return err;
 613}
 614
 615static void exp_flags(struct seq_file *m, int flag, int fsid,
 616                uid_t anonu, uid_t anong, struct nfsd4_fs_locations *fslocs);
 617static void show_secinfo(struct seq_file *m, struct svc_export *exp);
 618
 619static int svc_export_show(struct seq_file *m,
 620                           struct cache_detail *cd,
 621                           struct cache_head *h)
 622{
 623        struct svc_export *exp ;
 624
 625        if (h ==NULL) {
 626                seq_puts(m, "#path domain(flags)\n");
 627                return 0;
 628        }
 629        exp = container_of(h, struct svc_export, h);
 630        seq_path(m, &exp->ex_path, " \t\n\\");
 631        seq_putc(m, '\t');
 632        seq_escape(m, exp->ex_client->name, " \t\n\\");
 633        seq_putc(m, '(');
 634        if (test_bit(CACHE_VALID, &h->flags) && 
 635            !test_bit(CACHE_NEGATIVE, &h->flags)) {
 636                exp_flags(m, exp->ex_flags, exp->ex_fsid,
 637                          exp->ex_anon_uid, exp->ex_anon_gid, &exp->ex_fslocs);
 638                if (exp->ex_uuid) {
 639                        int i;
 640                        seq_puts(m, ",uuid=");
 641                        for (i=0; i<16; i++) {
 642                                if ((i&3) == 0 && i)
 643                                        seq_putc(m, ':');
 644                                seq_printf(m, "%02x", exp->ex_uuid[i]);
 645                        }
 646                }
 647                show_secinfo(m, exp);
 648        }
 649        seq_puts(m, ")\n");
 650        return 0;
 651}
 652static int svc_export_match(struct cache_head *a, struct cache_head *b)
 653{
 654        struct svc_export *orig = container_of(a, struct svc_export, h);
 655        struct svc_export *new = container_of(b, struct svc_export, h);
 656        return orig->ex_client == new->ex_client &&
 657                orig->ex_path.dentry == new->ex_path.dentry &&
 658                orig->ex_path.mnt == new->ex_path.mnt;
 659}
 660
 661static void svc_export_init(struct cache_head *cnew, struct cache_head *citem)
 662{
 663        struct svc_export *new = container_of(cnew, struct svc_export, h);
 664        struct svc_export *item = container_of(citem, struct svc_export, h);
 665
 666        kref_get(&item->ex_client->ref);
 667        new->ex_client = item->ex_client;
 668        new->ex_path.dentry = dget(item->ex_path.dentry);
 669        new->ex_path.mnt = mntget(item->ex_path.mnt);
 670        new->ex_fslocs.locations = NULL;
 671        new->ex_fslocs.locations_count = 0;
 672        new->ex_fslocs.migrated = 0;
 673        new->cd = item->cd;
 674}
 675
 676static void export_update(struct cache_head *cnew, struct cache_head *citem)
 677{
 678        struct svc_export *new = container_of(cnew, struct svc_export, h);
 679        struct svc_export *item = container_of(citem, struct svc_export, h);
 680        int i;
 681
 682        new->ex_flags = item->ex_flags;
 683        new->ex_anon_uid = item->ex_anon_uid;
 684        new->ex_anon_gid = item->ex_anon_gid;
 685        new->ex_fsid = item->ex_fsid;
 686        new->ex_uuid = item->ex_uuid;
 687        item->ex_uuid = NULL;
 688        new->ex_fslocs.locations = item->ex_fslocs.locations;
 689        item->ex_fslocs.locations = NULL;
 690        new->ex_fslocs.locations_count = item->ex_fslocs.locations_count;
 691        item->ex_fslocs.locations_count = 0;
 692        new->ex_fslocs.migrated = item->ex_fslocs.migrated;
 693        item->ex_fslocs.migrated = 0;
 694        new->ex_nflavors = item->ex_nflavors;
 695        for (i = 0; i < MAX_SECINFO_LIST; i++) {
 696                new->ex_flavors[i] = item->ex_flavors[i];
 697        }
 698}
 699
 700static struct cache_head *svc_export_alloc(void)
 701{
 702        struct svc_export *i = kmalloc(sizeof(*i), GFP_KERNEL);
 703        if (i)
 704                return &i->h;
 705        else
 706                return NULL;
 707}
 708
 709static struct cache_detail svc_export_cache_template = {
 710        .owner          = THIS_MODULE,
 711        .hash_size      = EXPORT_HASHMAX,
 712        .name           = "nfsd.export",
 713        .cache_put      = svc_export_put,
 714        .cache_upcall   = svc_export_upcall,
 715        .cache_parse    = svc_export_parse,
 716        .cache_show     = svc_export_show,
 717        .match          = svc_export_match,
 718        .init           = svc_export_init,
 719        .update         = export_update,
 720        .alloc          = svc_export_alloc,
 721};
 722
 723static int
 724svc_export_hash(struct svc_export *exp)
 725{
 726        int hash;
 727
 728        hash = hash_ptr(exp->ex_client, EXPORT_HASHBITS);
 729        hash ^= hash_ptr(exp->ex_path.dentry, EXPORT_HASHBITS);
 730        hash ^= hash_ptr(exp->ex_path.mnt, EXPORT_HASHBITS);
 731        return hash;
 732}
 733
 734static struct svc_export *
 735svc_export_lookup(struct svc_export *exp)
 736{
 737        struct cache_head *ch;
 738        int hash = svc_export_hash(exp);
 739
 740        ch = sunrpc_cache_lookup(exp->cd, &exp->h, hash);
 741        if (ch)
 742                return container_of(ch, struct svc_export, h);
 743        else
 744                return NULL;
 745}
 746
 747static struct svc_export *
 748svc_export_update(struct svc_export *new, struct svc_export *old)
 749{
 750        struct cache_head *ch;
 751        int hash = svc_export_hash(old);
 752
 753        ch = sunrpc_cache_update(old->cd, &new->h, &old->h, hash);
 754        if (ch)
 755                return container_of(ch, struct svc_export, h);
 756        else
 757                return NULL;
 758}
 759
 760
 761static struct svc_expkey *
 762exp_find_key(struct cache_detail *cd, svc_client *clp, int fsid_type,
 763             u32 *fsidv, struct cache_req *reqp)
 764{
 765        struct svc_expkey key, *ek;
 766        int err;
 767        
 768        if (!clp)
 769                return ERR_PTR(-ENOENT);
 770
 771        key.ek_client = clp;
 772        key.ek_fsidtype = fsid_type;
 773        memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
 774
 775        ek = svc_expkey_lookup(cd, &key);
 776        if (ek == NULL)
 777                return ERR_PTR(-ENOMEM);
 778        err = cache_check(cd, &ek->h, reqp);
 779        if (err)
 780                return ERR_PTR(err);
 781        return ek;
 782}
 783
 784
 785static svc_export *exp_get_by_name(struct cache_detail *cd, svc_client *clp,
 786                                   const struct path *path, struct cache_req *reqp)
 787{
 788        struct svc_export *exp, key;
 789        int err;
 790
 791        if (!clp)
 792                return ERR_PTR(-ENOENT);
 793
 794        key.ex_client = clp;
 795        key.ex_path = *path;
 796        key.cd = cd;
 797
 798        exp = svc_export_lookup(&key);
 799        if (exp == NULL)
 800                return ERR_PTR(-ENOMEM);
 801        err = cache_check(cd, &exp->h, reqp);
 802        if (err)
 803                return ERR_PTR(err);
 804        return exp;
 805}
 806
 807/*
 808 * Find the export entry for a given dentry.
 809 */
 810static struct svc_export *exp_parent(struct cache_detail *cd, svc_client *clp,
 811                                     struct path *path)
 812{
 813        struct dentry *saved = dget(path->dentry);
 814        svc_export *exp = exp_get_by_name(cd, clp, path, NULL);
 815
 816        while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
 817                struct dentry *parent = dget_parent(path->dentry);
 818                dput(path->dentry);
 819                path->dentry = parent;
 820                exp = exp_get_by_name(cd, clp, path, NULL);
 821        }
 822        dput(path->dentry);
 823        path->dentry = saved;
 824        return exp;
 825}
 826
 827
 828
 829/*
 830 * Obtain the root fh on behalf of a client.
 831 * This could be done in user space, but I feel that it adds some safety
 832 * since its harder to fool a kernel module than a user space program.
 833 */
 834int
 835exp_rootfh(struct net *net, svc_client *clp, char *name,
 836           struct knfsd_fh *f, int maxsize)
 837{
 838        struct svc_export       *exp;
 839        struct path             path;
 840        struct inode            *inode;
 841        struct svc_fh           fh;
 842        int                     err;
 843        struct nfsd_net         *nn = net_generic(net, nfsd_net_id);
 844        struct cache_detail     *cd = nn->svc_export_cache;
 845
 846        err = -EPERM;
 847        /* NB: we probably ought to check that it's NUL-terminated */
 848        if (kern_path(name, 0, &path)) {
 849                printk("nfsd: exp_rootfh path not found %s", name);
 850                return err;
 851        }
 852        inode = path.dentry->d_inode;
 853
 854        dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
 855                 name, path.dentry, clp->name,
 856                 inode->i_sb->s_id, inode->i_ino);
 857        exp = exp_parent(cd, clp, &path);
 858        if (IS_ERR(exp)) {
 859                err = PTR_ERR(exp);
 860                goto out;
 861        }
 862
 863        /*
 864         * fh must be initialized before calling fh_compose
 865         */
 866        fh_init(&fh, maxsize);
 867        if (fh_compose(&fh, exp, path.dentry, NULL))
 868                err = -EINVAL;
 869        else
 870                err = 0;
 871        memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
 872        fh_put(&fh);
 873        exp_put(exp);
 874out:
 875        path_put(&path);
 876        return err;
 877}
 878
 879static struct svc_export *exp_find(struct cache_detail *cd,
 880                                   struct auth_domain *clp, int fsid_type,
 881                                   u32 *fsidv, struct cache_req *reqp)
 882{
 883        struct svc_export *exp;
 884        struct nfsd_net *nn = net_generic(cd->net, nfsd_net_id);
 885        struct svc_expkey *ek = exp_find_key(nn->svc_expkey_cache, clp, fsid_type, fsidv, reqp);
 886        if (IS_ERR(ek))
 887                return ERR_CAST(ek);
 888
 889        exp = exp_get_by_name(cd, clp, &ek->ek_path, reqp);
 890        cache_put(&ek->h, nn->svc_expkey_cache);
 891
 892        if (IS_ERR(exp))
 893                return ERR_CAST(exp);
 894        return exp;
 895}
 896
 897__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp)
 898{
 899        struct exp_flavor_info *f;
 900        struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
 901
 902        /* legacy gss-only clients are always OK: */
 903        if (exp->ex_client == rqstp->rq_gssclient)
 904                return 0;
 905        /* ip-address based client; check sec= export option: */
 906        for (f = exp->ex_flavors; f < end; f++) {
 907                if (f->pseudoflavor == rqstp->rq_cred.cr_flavor)
 908                        return 0;
 909        }
 910        /* defaults in absence of sec= options: */
 911        if (exp->ex_nflavors == 0) {
 912                if (rqstp->rq_cred.cr_flavor == RPC_AUTH_NULL ||
 913                    rqstp->rq_cred.cr_flavor == RPC_AUTH_UNIX)
 914                        return 0;
 915        }
 916        return nfserr_wrongsec;
 917}
 918
 919/*
 920 * Uses rq_client and rq_gssclient to find an export; uses rq_client (an
 921 * auth_unix client) if it's available and has secinfo information;
 922 * otherwise, will try to use rq_gssclient.
 923 *
 924 * Called from functions that handle requests; functions that do work on
 925 * behalf of mountd are passed a single client name to use, and should
 926 * use exp_get_by_name() or exp_find().
 927 */
 928struct svc_export *
 929rqst_exp_get_by_name(struct svc_rqst *rqstp, struct path *path)
 930{
 931        struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
 932        struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 933        struct cache_detail *cd = nn->svc_export_cache;
 934
 935        if (rqstp->rq_client == NULL)
 936                goto gss;
 937
 938        /* First try the auth_unix client: */
 939        exp = exp_get_by_name(cd, rqstp->rq_client, path, &rqstp->rq_chandle);
 940        if (PTR_ERR(exp) == -ENOENT)
 941                goto gss;
 942        if (IS_ERR(exp))
 943                return exp;
 944        /* If it has secinfo, assume there are no gss/... clients */
 945        if (exp->ex_nflavors > 0)
 946                return exp;
 947gss:
 948        /* Otherwise, try falling back on gss client */
 949        if (rqstp->rq_gssclient == NULL)
 950                return exp;
 951        gssexp = exp_get_by_name(cd, rqstp->rq_gssclient, path, &rqstp->rq_chandle);
 952        if (PTR_ERR(gssexp) == -ENOENT)
 953                return exp;
 954        if (!IS_ERR(exp))
 955                exp_put(exp);
 956        return gssexp;
 957}
 958
 959struct svc_export *
 960rqst_exp_find(struct svc_rqst *rqstp, int fsid_type, u32 *fsidv)
 961{
 962        struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
 963        struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 964        struct cache_detail *cd = nn->svc_export_cache;
 965
 966        if (rqstp->rq_client == NULL)
 967                goto gss;
 968
 969        /* First try the auth_unix client: */
 970        exp = exp_find(cd, rqstp->rq_client, fsid_type,
 971                       fsidv, &rqstp->rq_chandle);
 972        if (PTR_ERR(exp) == -ENOENT)
 973                goto gss;
 974        if (IS_ERR(exp))
 975                return exp;
 976        /* If it has secinfo, assume there are no gss/... clients */
 977        if (exp->ex_nflavors > 0)
 978                return exp;
 979gss:
 980        /* Otherwise, try falling back on gss client */
 981        if (rqstp->rq_gssclient == NULL)
 982                return exp;
 983        gssexp = exp_find(cd, rqstp->rq_gssclient, fsid_type, fsidv,
 984                                                &rqstp->rq_chandle);
 985        if (PTR_ERR(gssexp) == -ENOENT)
 986                return exp;
 987        if (!IS_ERR(exp))
 988                exp_put(exp);
 989        return gssexp;
 990}
 991
 992struct svc_export *
 993rqst_exp_parent(struct svc_rqst *rqstp, struct path *path)
 994{
 995        struct dentry *saved = dget(path->dentry);
 996        struct svc_export *exp = rqst_exp_get_by_name(rqstp, path);
 997
 998        while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
 999                struct dentry *parent = dget_parent(path->dentry);
1000                dput(path->dentry);
1001                path->dentry = parent;
1002                exp = rqst_exp_get_by_name(rqstp, path);
1003        }
1004        dput(path->dentry);
1005        path->dentry = saved;
1006        return exp;
1007}
1008
1009struct svc_export *rqst_find_fsidzero_export(struct svc_rqst *rqstp)
1010{
1011        u32 fsidv[2];
1012
1013        mk_fsid(FSID_NUM, fsidv, 0, 0, 0, NULL);
1014
1015        return rqst_exp_find(rqstp, FSID_NUM, fsidv);
1016}
1017
1018/*
1019 * Called when we need the filehandle for the root of the pseudofs,
1020 * for a given NFSv4 client.   The root is defined to be the
1021 * export point with fsid==0
1022 */
1023__be32
1024exp_pseudoroot(struct svc_rqst *rqstp, struct svc_fh *fhp)
1025{
1026        struct svc_export *exp;
1027        __be32 rv;
1028
1029        exp = rqst_find_fsidzero_export(rqstp);
1030        if (IS_ERR(exp))
1031                return nfserrno(PTR_ERR(exp));
1032        rv = fh_compose(fhp, exp, exp->ex_path.dentry, NULL);
1033        exp_put(exp);
1034        return rv;
1035}
1036
1037/* Iterator */
1038
1039static void *e_start(struct seq_file *m, loff_t *pos)
1040        __acquires(((struct cache_detail *)m->private)->hash_lock)
1041{
1042        loff_t n = *pos;
1043        unsigned hash, export;
1044        struct cache_head *ch;
1045        struct cache_detail *cd = m->private;
1046        struct cache_head **export_table = cd->hash_table;
1047
1048        read_lock(&cd->hash_lock);
1049        if (!n--)
1050                return SEQ_START_TOKEN;
1051        hash = n >> 32;
1052        export = n & ((1LL<<32) - 1);
1053
1054        
1055        for (ch=export_table[hash]; ch; ch=ch->next)
1056                if (!export--)
1057                        return ch;
1058        n &= ~((1LL<<32) - 1);
1059        do {
1060                hash++;
1061                n += 1LL<<32;
1062        } while(hash < EXPORT_HASHMAX && export_table[hash]==NULL);
1063        if (hash >= EXPORT_HASHMAX)
1064                return NULL;
1065        *pos = n+1;
1066        return export_table[hash];
1067}
1068
1069static void *e_next(struct seq_file *m, void *p, loff_t *pos)
1070{
1071        struct cache_head *ch = p;
1072        int hash = (*pos >> 32);
1073        struct cache_detail *cd = m->private;
1074        struct cache_head **export_table = cd->hash_table;
1075
1076        if (p == SEQ_START_TOKEN)
1077                hash = 0;
1078        else if (ch->next == NULL) {
1079                hash++;
1080                *pos += 1LL<<32;
1081        } else {
1082                ++*pos;
1083                return ch->next;
1084        }
1085        *pos &= ~((1LL<<32) - 1);
1086        while (hash < EXPORT_HASHMAX && export_table[hash] == NULL) {
1087                hash++;
1088                *pos += 1LL<<32;
1089        }
1090        if (hash >= EXPORT_HASHMAX)
1091                return NULL;
1092        ++*pos;
1093        return export_table[hash];
1094}
1095
1096static void e_stop(struct seq_file *m, void *p)
1097        __releases(((struct cache_detail *)m->private)->hash_lock)
1098{
1099        struct cache_detail *cd = m->private;
1100
1101        read_unlock(&cd->hash_lock);
1102}
1103
1104static struct flags {
1105        int flag;
1106        char *name[2];
1107} expflags[] = {
1108        { NFSEXP_READONLY, {"ro", "rw"}},
1109        { NFSEXP_INSECURE_PORT, {"insecure", ""}},
1110        { NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
1111        { NFSEXP_ALLSQUASH, {"all_squash", ""}},
1112        { NFSEXP_ASYNC, {"async", "sync"}},
1113        { NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
1114        { NFSEXP_NOHIDE, {"nohide", ""}},
1115        { NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
1116        { NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
1117        { NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
1118        { NFSEXP_V4ROOT, {"v4root", ""}},
1119        { 0, {"", ""}}
1120};
1121
1122static void show_expflags(struct seq_file *m, int flags, int mask)
1123{
1124        struct flags *flg;
1125        int state, first = 0;
1126
1127        for (flg = expflags; flg->flag; flg++) {
1128                if (flg->flag & ~mask)
1129                        continue;
1130                state = (flg->flag & flags) ? 0 : 1;
1131                if (*flg->name[state])
1132                        seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
1133        }
1134}
1135
1136static void show_secinfo_flags(struct seq_file *m, int flags)
1137{
1138        seq_printf(m, ",");
1139        show_expflags(m, flags, NFSEXP_SECINFO_FLAGS);
1140}
1141
1142static bool secinfo_flags_equal(int f, int g)
1143{
1144        f &= NFSEXP_SECINFO_FLAGS;
1145        g &= NFSEXP_SECINFO_FLAGS;
1146        return f == g;
1147}
1148
1149static int show_secinfo_run(struct seq_file *m, struct exp_flavor_info **fp, struct exp_flavor_info *end)
1150{
1151        int flags;
1152
1153        flags = (*fp)->flags;
1154        seq_printf(m, ",sec=%d", (*fp)->pseudoflavor);
1155        (*fp)++;
1156        while (*fp != end && secinfo_flags_equal(flags, (*fp)->flags)) {
1157                seq_printf(m, ":%d", (*fp)->pseudoflavor);
1158                (*fp)++;
1159        }
1160        return flags;
1161}
1162
1163static void show_secinfo(struct seq_file *m, struct svc_export *exp)
1164{
1165        struct exp_flavor_info *f;
1166        struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
1167        int flags;
1168
1169        if (exp->ex_nflavors == 0)
1170                return;
1171        f = exp->ex_flavors;
1172        flags = show_secinfo_run(m, &f, end);
1173        if (!secinfo_flags_equal(flags, exp->ex_flags))
1174                show_secinfo_flags(m, flags);
1175        while (f != end) {
1176                flags = show_secinfo_run(m, &f, end);
1177                show_secinfo_flags(m, flags);
1178        }
1179}
1180
1181static void exp_flags(struct seq_file *m, int flag, int fsid,
1182                uid_t anonu, uid_t anong, struct nfsd4_fs_locations *fsloc)
1183{
1184        show_expflags(m, flag, NFSEXP_ALLFLAGS);
1185        if (flag & NFSEXP_FSID)
1186                seq_printf(m, ",fsid=%d", fsid);
1187        if (anonu != (uid_t)-2 && anonu != (0x10000-2))
1188                seq_printf(m, ",anonuid=%u", anonu);
1189        if (anong != (gid_t)-2 && anong != (0x10000-2))
1190                seq_printf(m, ",anongid=%u", anong);
1191        if (fsloc && fsloc->locations_count > 0) {
1192                char *loctype = (fsloc->migrated) ? "refer" : "replicas";
1193                int i;
1194
1195                seq_printf(m, ",%s=", loctype);
1196                seq_escape(m, fsloc->locations[0].path, ",;@ \t\n\\");
1197                seq_putc(m, '@');
1198                seq_escape(m, fsloc->locations[0].hosts, ",;@ \t\n\\");
1199                for (i = 1; i < fsloc->locations_count; i++) {
1200                        seq_putc(m, ';');
1201                        seq_escape(m, fsloc->locations[i].path, ",;@ \t\n\\");
1202                        seq_putc(m, '@');
1203                        seq_escape(m, fsloc->locations[i].hosts, ",;@ \t\n\\");
1204                }
1205        }
1206}
1207
1208static int e_show(struct seq_file *m, void *p)
1209{
1210        struct cache_head *cp = p;
1211        struct svc_export *exp = container_of(cp, struct svc_export, h);
1212        struct cache_detail *cd = m->private;
1213
1214        if (p == SEQ_START_TOKEN) {
1215                seq_puts(m, "# Version 1.1\n");
1216                seq_puts(m, "# Path Client(Flags) # IPs\n");
1217                return 0;
1218        }
1219
1220        cache_get(&exp->h);
1221        if (cache_check(cd, &exp->h, NULL))
1222                return 0;
1223        exp_put(exp);
1224        return svc_export_show(m, cd, cp);
1225}
1226
1227const struct seq_operations nfs_exports_op = {
1228        .start  = e_start,
1229        .next   = e_next,
1230        .stop   = e_stop,
1231        .show   = e_show,
1232};
1233
1234/*
1235 * Initialize the exports module.
1236 */
1237int
1238nfsd_export_init(struct net *net)
1239{
1240        int rv;
1241        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1242
1243        dprintk("nfsd: initializing export module (net: %p).\n", net);
1244
1245        nn->svc_export_cache = cache_create_net(&svc_export_cache_template, net);
1246        if (IS_ERR(nn->svc_export_cache))
1247                return PTR_ERR(nn->svc_export_cache);
1248        rv = cache_register_net(nn->svc_export_cache, net);
1249        if (rv)
1250                goto destroy_export_cache;
1251
1252        nn->svc_expkey_cache = cache_create_net(&svc_expkey_cache_template, net);
1253        if (IS_ERR(nn->svc_expkey_cache)) {
1254                rv = PTR_ERR(nn->svc_expkey_cache);
1255                goto unregister_export_cache;
1256        }
1257        rv = cache_register_net(nn->svc_expkey_cache, net);
1258        if (rv)
1259                goto destroy_expkey_cache;
1260        return 0;
1261
1262destroy_expkey_cache:
1263        cache_destroy_net(nn->svc_expkey_cache, net);
1264unregister_export_cache:
1265        cache_unregister_net(nn->svc_export_cache, net);
1266destroy_export_cache:
1267        cache_destroy_net(nn->svc_export_cache, net);
1268        return rv;
1269}
1270
1271/*
1272 * Flush exports table - called when last nfsd thread is killed
1273 */
1274void
1275nfsd_export_flush(struct net *net)
1276{
1277        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1278
1279        cache_purge(nn->svc_expkey_cache);
1280        cache_purge(nn->svc_export_cache);
1281}
1282
1283/*
1284 * Shutdown the exports module.
1285 */
1286void
1287nfsd_export_shutdown(struct net *net)
1288{
1289        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1290
1291        dprintk("nfsd: shutting down export module (net: %p).\n", net);
1292
1293        cache_unregister_net(nn->svc_expkey_cache, net);
1294        cache_unregister_net(nn->svc_export_cache, net);
1295        cache_destroy_net(nn->svc_expkey_cache, net);
1296        cache_destroy_net(nn->svc_export_cache, net);
1297        svcauth_unix_purge(net);
1298
1299        dprintk("nfsd: export shutdown complete (net: %p).\n", net);
1300}
1301
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