fs/nfs/nfs4idmap.c

   1 /*
   2  * fs/nfs/idmap.c
   3  *
   4  *  UID and GID to name mapping for clients.
   5  *
   6  *  Copyright (c) 2002 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Marius Aamodt Eriksen <marius@umich.edu>
  10  *
  11  *  Redistribution and use in source and binary forms, with or without
  12  *  modification, are permitted provided that the following conditions
  13  *  are met:
  14  *
  15  *  1. Redistributions of source code must retain the above copyright
  16  *     notice, this list of conditions and the following disclaimer.
  17  *  2. Redistributions in binary form must reproduce the above copyright
  18  *     notice, this list of conditions and the following disclaimer in the
  19  *     documentation and/or other materials provided with the distribution.
  20  *  3. Neither the name of the University nor the names of its
  21  *     contributors may be used to endorse or promote products derived
  22  *     from this software without specific prior written permission.
  23  *
  24  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  25  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  26  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  27  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  31  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  32  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  33  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  34  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  */
  36 #include <linux/types.h>
  37 #include <linux/parser.h>
  38 #include <linux/fs.h>
  39 #include <net/net_namespace.h>
  40 #include <linux/sunrpc/rpc_pipe_fs.h>
  41 #include <linux/nfs_fs.h>
  42 #include <linux/nfs_fs_sb.h>
  43 #include <linux/key.h>
  44 #include <linux/keyctl.h>
  45 #include <linux/key-type.h>
  46 #include <keys/user-type.h>
  47 #include <linux/module.h>
  48
  49 #include "internal.h"
  50 #include "netns.h"
  51 #include "nfs4idmap.h"
  52 #include "nfs4trace.h"
  53
  54 #define NFS_UINT_MAXLEN 11
  55
  56 static const struct cred *id_resolver_cache;
  57 static struct key_type key_type_id_resolver_legacy;
  58
  59 struct idmap_legacy_upcalldata {
  60         struct rpc_pipe_msg pipe_msg;
  61         struct idmap_msg idmap_msg;
  62         struct key_construction *key_cons;
  63         struct idmap *idmap;
  64 };
  65
  66 struct idmap {
  67         struct rpc_pipe_dir_object idmap_pdo;
  68         struct rpc_pipe         *idmap_pipe;
  69         struct idmap_legacy_upcalldata *idmap_upcall_data;
  70         struct mutex            idmap_mutex;
  71 };
  72
  73 /**
  74  * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
  75  * @fattr: fully initialised struct nfs_fattr
  76  * @owner_name: owner name string cache
  77  * @group_name: group name string cache
  78  */
  79 void nfs_fattr_init_names(struct nfs_fattr *fattr,
  80                 struct nfs4_string *owner_name,
  81                 struct nfs4_string *group_name)
  82 {
  83         fattr->owner_name = owner_name;
  84         fattr->group_name = group_name;
  85 }
  86
  87 static void nfs_fattr_free_owner_name(struct nfs_fattr *fattr)
  88 {
  89         fattr->valid &= ~NFS_ATTR_FATTR_OWNER_NAME;
  90         kfree(fattr->owner_name->data);
  91 }
  92
  93 static void nfs_fattr_free_group_name(struct nfs_fattr *fattr)
  94 {
  95         fattr->valid &= ~NFS_ATTR_FATTR_GROUP_NAME;
  96         kfree(fattr->group_name->data);
  97 }
  98
  99 static bool nfs_fattr_map_owner_name(struct nfs_server *server, struct nfs_fattr *fattr)
 100 {
 101         struct nfs4_string *owner = fattr->owner_name;
 102         kuid_t uid;
 103
 104         if (!(fattr->valid & NFS_ATTR_FATTR_OWNER_NAME))
 105                 return false;
 106         if (nfs_map_name_to_uid(server, owner->data, owner->len, &uid) == 0) {
 107                 fattr->uid = uid;
 108                 fattr->valid |= NFS_ATTR_FATTR_OWNER;
 109         }
 110         return true;
 111 }
 112
 113 static bool nfs_fattr_map_group_name(struct nfs_server *server, struct nfs_fattr *fattr)
 114 {
 115         struct nfs4_string *group = fattr->group_name;
 116         kgid_t gid;
 117
 118         if (!(fattr->valid & NFS_ATTR_FATTR_GROUP_NAME))
 119                 return false;
 120         if (nfs_map_group_to_gid(server, group->data, group->len, &gid) == 0) {
 121                 fattr->gid = gid;
 122                 fattr->valid |= NFS_ATTR_FATTR_GROUP;
 123         }
 124         return true;
 125 }
 126
 127 /**
 128  * nfs_fattr_free_names - free up the NFSv4 owner and group strings
 129  * @fattr: a fully initialised nfs_fattr structure
 130  */
 131 void nfs_fattr_free_names(struct nfs_fattr *fattr)
 132 {
 133         if (fattr->valid & NFS_ATTR_FATTR_OWNER_NAME)
 134                 nfs_fattr_free_owner_name(fattr);
 135         if (fattr->valid & NFS_ATTR_FATTR_GROUP_NAME)
 136                 nfs_fattr_free_group_name(fattr);
 137 }
 138
 139 /**
 140  * nfs_fattr_map_and_free_names - map owner/group strings into uid/gid and free
 141  * @server: pointer to the filesystem nfs_server structure
 142  * @fattr: a fully initialised nfs_fattr structure
 143  *
 144  * This helper maps the cached NFSv4 owner/group strings in fattr into
 145  * their numeric uid/gid equivalents, and then frees the cached strings.
 146  */
 147 void nfs_fattr_map_and_free_names(struct nfs_server *server, struct nfs_fattr *fattr)
 148 {
 149         if (nfs_fattr_map_owner_name(server, fattr))
 150                 nfs_fattr_free_owner_name(fattr);
 151         if (nfs_fattr_map_group_name(server, fattr))
 152                 nfs_fattr_free_group_name(fattr);
 153 }
 154
 155 int nfs_map_string_to_numeric(const char *name, size_t namelen, __u32 *res)
 156 {
 157         unsigned long val;
 158         char buf[16];
 159
 160         if (memchr(name, '@', namelen) != NULL || namelen >= sizeof(buf))
 161                 return 0;
 162         memcpy(buf, name, namelen);
 163         buf[namelen] = '\0';
 164         if (kstrtoul(buf, 0, &val) != 0)
 165                 return 0;
 166         *res = val;
 167         return 1;
 168 }
 169 EXPORT_SYMBOL_GPL(nfs_map_string_to_numeric);
 170
 171 static int nfs_map_numeric_to_string(__u32 id, char *buf, size_t buflen)
 172 {
 173         return snprintf(buf, buflen, "%u", id);
 174 }
 175
 176 static struct key_type key_type_id_resolver = {
 177         .name           = "id_resolver",
 178         .preparse       = user_preparse,
 179         .free_preparse  = user_free_preparse,
 180         .instantiate    = generic_key_instantiate,
 181         .revoke         = user_revoke,
 182         .destroy        = user_destroy,
 183         .describe       = user_describe,
 184         .read           = user_read,
 185 };
 186
 187 static int nfs_idmap_init_keyring(void)
 188 {
 189         struct cred *cred;
 190         struct key *keyring;
 191         int ret = 0;
 192
 193         printk(KERN_NOTICE "NFS: Registering the %s key type\n",
 194                 key_type_id_resolver.name);
 195
 196         cred = prepare_kernel_cred(NULL);
 197         if (!cred)
 198                 return -ENOMEM;
 199
 200         keyring = keyring_alloc(".id_resolver",
 201                                 GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
 202                                 (KEY_POS_ALL & ~KEY_POS_SETATTR) |
 203                                 KEY_USR_VIEW | KEY_USR_READ,
 204                                 KEY_ALLOC_NOT_IN_QUOTA, NULL);
 205         if (IS_ERR(keyring)) {
 206                 ret = PTR_ERR(keyring);
 207                 goto failed_put_cred;
 208         }
 209
 210         ret = register_key_type(&key_type_id_resolver);
 211         if (ret < 0)
 212                 goto failed_put_key;
 213
 214         ret = register_key_type(&key_type_id_resolver_legacy);
 215         if (ret < 0)
 216                 goto failed_reg_legacy;
 217
 218         set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
 219         cred->thread_keyring = keyring;
 220         cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
 221         id_resolver_cache = cred;
 222         return 0;
 223
 224 failed_reg_legacy:
 225         unregister_key_type(&key_type_id_resolver);
 226 failed_put_key:
 227         key_put(keyring);
 228 failed_put_cred:
 229         put_cred(cred);
 230         return ret;
 231 }
 232
 233 static void nfs_idmap_quit_keyring(void)
 234 {
 235         key_revoke(id_resolver_cache->thread_keyring);
 236         unregister_key_type(&key_type_id_resolver);
 237         unregister_key_type(&key_type_id_resolver_legacy);
 238         put_cred(id_resolver_cache);
 239 }
 240
 241 /*
 242  * Assemble the description to pass to request_key()
 243  * This function will allocate a new string and update dest to point
 244  * at it.  The caller is responsible for freeing dest.
 245  *
 246  * On error 0 is returned.  Otherwise, the length of dest is returned.
 247  */
 248 static ssize_t nfs_idmap_get_desc(const char *name, size_t namelen,
 249                                 const char *type, size_t typelen, char **desc)
 250 {
 251         char *cp;
 252         size_t desclen = typelen + namelen + 2;
 253
 254         *desc = kmalloc(desclen, GFP_KERNEL);
 255         if (!*desc)
 256                 return -ENOMEM;
 257
 258         cp = *desc;
 259         memcpy(cp, type, typelen);
 260         cp += typelen;
 261         *cp++ = ':';
 262
 263         memcpy(cp, name, namelen);
 264         cp += namelen;
 265         *cp = '\0';
 266         return desclen;
 267 }
 268
 269 static struct key *nfs_idmap_request_key(const char *name, size_t namelen,
 270                                          const char *type, struct idmap *idmap)
 271 {
 272         char *desc;
 273         struct key *rkey;
 274         ssize_t ret;
 275
 276         ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
 277         if (ret <= 0)
 278                 return ERR_PTR(ret);
 279
 280         rkey = request_key(&key_type_id_resolver, desc, "");
 281         if (IS_ERR(rkey)) {
 282                 mutex_lock(&idmap->idmap_mutex);
 283                 rkey = request_key_with_auxdata(&key_type_id_resolver_legacy,
 284                                                 desc, "", 0, idmap);
 285                 mutex_unlock(&idmap->idmap_mutex);
 286         }
 287         if (!IS_ERR(rkey))
 288                 set_bit(KEY_FLAG_ROOT_CAN_INVAL, &rkey->flags);
 289
 290         kfree(desc);
 291         return rkey;
 292 }
 293
 294 static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
 295                                  const char *type, void *data,
 296                                  size_t data_size, struct idmap *idmap)
 297 {
 298         const struct cred *saved_cred;
 299         struct key *rkey;
 300         struct user_key_payload *payload;
 301         ssize_t ret;
 302
 303         saved_cred = override_creds(id_resolver_cache);
 304         rkey = nfs_idmap_request_key(name, namelen, type, idmap);
 305         revert_creds(saved_cred);
 306
 307         if (IS_ERR(rkey)) {
 308                 ret = PTR_ERR(rkey);
 309                 goto out;
 310         }
 311
 312         rcu_read_lock();
 313         rkey->perm |= KEY_USR_VIEW;
 314
 315         ret = key_validate(rkey);
 316         if (ret < 0)
 317                 goto out_up;
 318
 319         payload = rcu_dereference(rkey->payload.rcudata);
 320         if (IS_ERR_OR_NULL(payload)) {
 321                 ret = PTR_ERR(payload);
 322                 goto out_up;
 323         }
 324
 325         ret = payload->datalen;
 326         if (ret > 0 && ret <= data_size)
 327                 memcpy(data, payload->data, ret);
 328         else
 329                 ret = -EINVAL;
 330
 331 out_up:
 332         rcu_read_unlock();
 333         key_put(rkey);
 334 out:
 335         return ret;
 336 }
 337
 338 /* ID -> Name */
 339 static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf,
 340                                      size_t buflen, struct idmap *idmap)
 341 {
 342         char id_str[NFS_UINT_MAXLEN];
 343         int id_len;
 344         ssize_t ret;
 345
 346         id_len = snprintf(id_str, sizeof(id_str), "%u", id);
 347         ret = nfs_idmap_get_key(id_str, id_len, type, buf, buflen, idmap);
 348         if (ret < 0)
 349                 return -EINVAL;
 350         return ret;
 351 }
 352
 353 /* Name -> ID */
 354 static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *type,
 355                                __u32 *id, struct idmap *idmap)
 356 {
 357         char id_str[NFS_UINT_MAXLEN];
 358         long id_long;
 359         ssize_t data_size;
 360         int ret = 0;
 361
 362         data_size = nfs_idmap_get_key(name, namelen, type, id_str, NFS_UINT_MAXLEN, idmap);
 363         if (data_size <= 0) {
 364                 ret = -EINVAL;
 365         } else {
 366                 ret = kstrtol(id_str, 10, &id_long);
 367                 *id = (__u32)id_long;
 368         }
 369         return ret;
 370 }
 371
 372 /* idmap classic begins here */
 373
 374 enum {
 375         Opt_find_uid, Opt_find_gid, Opt_find_user, Opt_find_group, Opt_find_err
 376 };
 377
 378 static const match_table_t nfs_idmap_tokens = {
 379         { Opt_find_uid, "uid:%s" },
 380         { Opt_find_gid, "gid:%s" },
 381         { Opt_find_user, "user:%s" },
 382         { Opt_find_group, "group:%s" },
 383         { Opt_find_err, NULL }
 384 };
 385
 386 static int nfs_idmap_legacy_upcall(struct key_construction *, const char *, void *);
 387 static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
 388                                    size_t);
 389 static void idmap_release_pipe(struct inode *);
 390 static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
 391
 392 static const struct rpc_pipe_ops idmap_upcall_ops = {
 393         .upcall         = rpc_pipe_generic_upcall,
 394         .downcall       = idmap_pipe_downcall,
 395         .release_pipe   = idmap_release_pipe,
 396         .destroy_msg    = idmap_pipe_destroy_msg,
 397 };
 398
 399 static struct key_type key_type_id_resolver_legacy = {
 400         .name           = "id_legacy",
 401         .preparse       = user_preparse,
 402         .free_preparse  = user_free_preparse,
 403         .instantiate    = generic_key_instantiate,
 404         .revoke         = user_revoke,
 405         .destroy        = user_destroy,
 406         .describe       = user_describe,
 407         .read           = user_read,
 408         .request_key    = nfs_idmap_legacy_upcall,
 409 };
 410
 411 static void nfs_idmap_pipe_destroy(struct dentry *dir,
 412                 struct rpc_pipe_dir_object *pdo)
 413 {
 414         struct idmap *idmap = pdo->pdo_data;
 415         struct rpc_pipe *pipe = idmap->idmap_pipe;
 416
 417         if (pipe->dentry) {
 418                 rpc_unlink(pipe->dentry);
 419                 pipe->dentry = NULL;
 420         }
 421 }
 422
 423 static int nfs_idmap_pipe_create(struct dentry *dir,
 424                 struct rpc_pipe_dir_object *pdo)
 425 {
 426         struct idmap *idmap = pdo->pdo_data;
 427         struct rpc_pipe *pipe = idmap->idmap_pipe;
 428         struct dentry *dentry;
 429
 430         dentry = rpc_mkpipe_dentry(dir, "idmap", idmap, pipe);
 431         if (IS_ERR(dentry))
 432                 return PTR_ERR(dentry);
 433         pipe->dentry = dentry;
 434         return 0;
 435 }
 436
 437 static const struct rpc_pipe_dir_object_ops nfs_idmap_pipe_dir_object_ops = {
 438         .create = nfs_idmap_pipe_create,
 439         .destroy = nfs_idmap_pipe_destroy,
 440 };
 441
 442 int
 443 nfs_idmap_new(struct nfs_client *clp)
 444 {
 445         struct idmap *idmap;
 446         struct rpc_pipe *pipe;
 447         int error;
 448
 449         idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
 450         if (idmap == NULL)
 451                 return -ENOMEM;
 452
 453         rpc_init_pipe_dir_object(&idmap->idmap_pdo,
 454                         &nfs_idmap_pipe_dir_object_ops,
 455                         idmap);
 456
 457         pipe = rpc_mkpipe_data(&idmap_upcall_ops, 0);
 458         if (IS_ERR(pipe)) {
 459                 error = PTR_ERR(pipe);
 460                 goto err;
 461         }
 462         idmap->idmap_pipe = pipe;
 463         mutex_init(&idmap->idmap_mutex);
 464
 465         error = rpc_add_pipe_dir_object(clp->cl_net,
 466                         &clp->cl_rpcclient->cl_pipedir_objects,
 467                         &idmap->idmap_pdo);
 468         if (error)
 469                 goto err_destroy_pipe;
 470
 471         clp->cl_idmap = idmap;
 472         return 0;
 473 err_destroy_pipe:
 474         rpc_destroy_pipe_data(idmap->idmap_pipe);
 475 err:
 476         kfree(idmap);
 477         return error;
 478 }
 479
 480 void
 481 nfs_idmap_delete(struct nfs_client *clp)
 482 {
 483         struct idmap *idmap = clp->cl_idmap;
 484
 485         if (!idmap)
 486                 return;
 487         clp->cl_idmap = NULL;
 488         rpc_remove_pipe_dir_object(clp->cl_net,
 489                         &clp->cl_rpcclient->cl_pipedir_objects,
 490                         &idmap->idmap_pdo);
 491         rpc_destroy_pipe_data(idmap->idmap_pipe);
 492         kfree(idmap);
 493 }
 494
 495 int nfs_idmap_init(void)
 496 {
 497         int ret;
 498         ret = nfs_idmap_init_keyring();
 499         if (ret != 0)
 500                 goto out;
 501 out:
 502         return ret;
 503 }
 504
 505 void nfs_idmap_quit(void)
 506 {
 507         nfs_idmap_quit_keyring();
 508 }
 509
 510 static int nfs_idmap_prepare_message(char *desc, struct idmap *idmap,
 511                                      struct idmap_msg *im,
 512                                      struct rpc_pipe_msg *msg)
 513 {
 514         substring_t substr;
 515         int token, ret;
 516
 517         im->im_type = IDMAP_TYPE_GROUP;
 518         token = match_token(desc, nfs_idmap_tokens, &substr);
 519
 520         switch (token) {
 521         case Opt_find_uid:
 522                 im->im_type = IDMAP_TYPE_USER;
 523         case Opt_find_gid:
 524                 im->im_conv = IDMAP_CONV_NAMETOID;
 525                 ret = match_strlcpy(im->im_name, &substr, IDMAP_NAMESZ);
 526                 break;
 527
 528         case Opt_find_user:
 529                 im->im_type = IDMAP_TYPE_USER;
 530         case Opt_find_group:
 531                 im->im_conv = IDMAP_CONV_IDTONAME;
 532                 ret = match_int(&substr, &im->im_id);
 533                 break;
 534
 535         default:
 536                 ret = -EINVAL;
 537                 goto out;
 538         }
 539
 540         msg->data = im;
 541         msg->len  = sizeof(struct idmap_msg);
 542
 543 out:
 544         return ret;
 545 }
 546
 547 static bool
 548 nfs_idmap_prepare_pipe_upcall(struct idmap *idmap,
 549                 struct idmap_legacy_upcalldata *data)
 550 {
 551         if (idmap->idmap_upcall_data != NULL) {
 552                 WARN_ON_ONCE(1);
 553                 return false;
 554         }
 555         idmap->idmap_upcall_data = data;
 556         return true;
 557 }
 558
 559 static void
 560 nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, int ret)
 561 {
 562         struct key_construction *cons = idmap->idmap_upcall_data->key_cons;
 563
 564         kfree(idmap->idmap_upcall_data);
 565         idmap->idmap_upcall_data = NULL;
 566         complete_request_key(cons, ret);
 567 }
 568
 569 static void
 570 nfs_idmap_abort_pipe_upcall(struct idmap *idmap, int ret)
 571 {
 572         if (idmap->idmap_upcall_data != NULL)
 573                 nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
 574 }
 575
 576 static int nfs_idmap_legacy_upcall(struct key_construction *cons,
 577                                    const char *op,
 578                                    void *aux)
 579 {
 580         struct idmap_legacy_upcalldata *data;
 581         struct rpc_pipe_msg *msg;
 582         struct idmap_msg *im;
 583         struct idmap *idmap = (struct idmap *)aux;
 584         struct key *key = cons->key;
 585         int ret = -ENOMEM;
 586
 587         /* msg and im are freed in idmap_pipe_destroy_msg */
 588         data = kzalloc(sizeof(*data), GFP_KERNEL);
 589         if (!data)
 590                 goto out1;
 591
 592         msg = &data->pipe_msg;
 593         im = &data->idmap_msg;
 594         data->idmap = idmap;
 595         data->key_cons = cons;
 596
 597         ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);
 598         if (ret < 0)
 599                 goto out2;
 600
 601         ret = -EAGAIN;
 602         if (!nfs_idmap_prepare_pipe_upcall(idmap, data))
 603                 goto out2;
 604
 605         ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
 606         if (ret < 0)
 607                 nfs_idmap_abort_pipe_upcall(idmap, ret);
 608
 609         return ret;
 610 out2:
 611         kfree(data);
 612 out1:
 613         complete_request_key(cons, ret);
 614         return ret;
 615 }
 616
 617 static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *data, size_t datalen)
 618 {
 619         return key_instantiate_and_link(key, data, datalen,
 620                                         id_resolver_cache->thread_keyring,
 621                                         authkey);
 622 }
 623
 624 static int nfs_idmap_read_and_verify_message(struct idmap_msg *im,
 625                 struct idmap_msg *upcall,
 626                 struct key *key, struct key *authkey)
 627 {
 628         char id_str[NFS_UINT_MAXLEN];
 629         size_t len;
 630         int ret = -ENOKEY;
 631
 632         /* ret = -ENOKEY */
 633         if (upcall->im_type != im->im_type || upcall->im_conv != im->im_conv)
 634                 goto out;
 635         switch (im->im_conv) {
 636         case IDMAP_CONV_NAMETOID:
 637                 if (strcmp(upcall->im_name, im->im_name) != 0)
 638                         break;
 639                 /* Note: here we store the NUL terminator too */
 640                 len = sprintf(id_str, "%d", im->im_id) + 1;
 641                 ret = nfs_idmap_instantiate(key, authkey, id_str, len);
 642                 break;
 643         case IDMAP_CONV_IDTONAME:
 644                 if (upcall->im_id != im->im_id)
 645                         break;
 646                 len = strlen(im->im_name);
 647                 ret = nfs_idmap_instantiate(key, authkey, im->im_name, len);
 648                 break;
 649         default:
 650                 ret = -EINVAL;
 651         }
 652 out:
 653         return ret;
 654 }
 655
 656 static ssize_t
 657 idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 658 {
 659         struct rpc_inode *rpci = RPC_I(file_inode(filp));
 660         struct idmap *idmap = (struct idmap *)rpci->private;
 661         struct key_construction *cons;
 662         struct idmap_msg im;
 663         size_t namelen_in;
 664         int ret = -ENOKEY;
 665
 666         /* If instantiation is successful, anyone waiting for key construction
 667          * will have been woken up and someone else may now have used
 668          * idmap_key_cons - so after this point we may no longer touch it.
 669          */
 670         if (idmap->idmap_upcall_data == NULL)
 671                 goto out_noupcall;
 672
 673         cons = idmap->idmap_upcall_data->key_cons;
 674
 675         if (mlen != sizeof(im)) {
 676                 ret = -ENOSPC;
 677                 goto out;
 678         }
 679
 680         if (copy_from_user(&im, src, mlen) != 0) {
 681                 ret = -EFAULT;
 682                 goto out;
 683         }
 684
 685         if (!(im.im_status & IDMAP_STATUS_SUCCESS)) {
 686                 ret = -ENOKEY;
 687                 goto out;
 688         }
 689
 690         namelen_in = strnlen(im.im_name, IDMAP_NAMESZ);
 691         if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
 692                 ret = -EINVAL;
 693                 goto out;
 694 }
 695
 696         ret = nfs_idmap_read_and_verify_message(&im,
 697                         &idmap->idmap_upcall_data->idmap_msg,
 698                         cons->key, cons->authkey);
 699         if (ret >= 0) {
 700                 key_set_timeout(cons->key, nfs_idmap_cache_timeout);
 701                 ret = mlen;
 702         }
 703
 704 out:
 705         nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
 706 out_noupcall:
 707         return ret;
 708 }
 709
 710 static void
 711 idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 712 {
 713         struct idmap_legacy_upcalldata *data = container_of(msg,
 714                         struct idmap_legacy_upcalldata,
 715                         pipe_msg);
 716         struct idmap *idmap = data->idmap;
 717
 718         if (msg->errno)
 719                 nfs_idmap_abort_pipe_upcall(idmap, msg->errno);
 720 }
 721
 722 static void
 723 idmap_release_pipe(struct inode *inode)
 724 {
 725         struct rpc_inode *rpci = RPC_I(inode);
 726         struct idmap *idmap = (struct idmap *)rpci->private;
 727
 728         nfs_idmap_abort_pipe_upcall(idmap, -EPIPE);
 729 }
 730
 731 int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, kuid_t *uid)
 732 {
 733         struct idmap *idmap = server->nfs_client->cl_idmap;
 734         __u32 id = -1;
 735         int ret = 0;
 736
 737         if (!nfs_map_string_to_numeric(name, namelen, &id))
 738                 ret = nfs_idmap_lookup_id(name, namelen, "uid", &id, idmap);
 739         if (ret == 0) {
 740                 *uid = make_kuid(&init_user_ns, id);
 741                 if (!uid_valid(*uid))
 742                         ret = -ERANGE;
 743         }
 744         trace_nfs4_map_name_to_uid(name, namelen, id, ret);
 745         return ret;
 746 }
 747
 748 int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, kgid_t *gid)
 749 {
 750         struct idmap *idmap = server->nfs_client->cl_idmap;
 751         __u32 id = -1;
 752         int ret = 0;
 753
 754         if (!nfs_map_string_to_numeric(name, namelen, &id))
 755                 ret = nfs_idmap_lookup_id(name, namelen, "gid", &id, idmap);
 756         if (ret == 0) {
 757                 *gid = make_kgid(&init_user_ns, id);
 758                 if (!gid_valid(*gid))
 759                         ret = -ERANGE;
 760         }
 761         trace_nfs4_map_group_to_gid(name, namelen, id, ret);
 762         return ret;
 763 }
 764
 765 int nfs_map_uid_to_name(const struct nfs_server *server, kuid_t uid, char *buf, size_t buflen)
 766 {
 767         struct idmap *idmap = server->nfs_client->cl_idmap;
 768         int ret = -EINVAL;
 769         __u32 id;
 770
 771         id = from_kuid(&init_user_ns, uid);
 772         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 773                 ret = nfs_idmap_lookup_name(id, "user", buf, buflen, idmap);
 774         if (ret < 0)
 775                 ret = nfs_map_numeric_to_string(id, buf, buflen);
 776         trace_nfs4_map_uid_to_name(buf, ret, id, ret);
 777         return ret;
 778 }
 779 int nfs_map_gid_to_group(const struct nfs_server *server, kgid_t gid, char *buf, size_t buflen)
 780 {
 781         struct idmap *idmap = server->nfs_client->cl_idmap;
 782         int ret = -EINVAL;
 783         __u32 id;
 784
 785         id = from_kgid(&init_user_ns, gid);
 786         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 787                 ret = nfs_idmap_lookup_name(id, "group", buf, buflen, idmap);
 788         if (ret < 0)
 789                 ret = nfs_map_numeric_to_string(id, buf, buflen);
 790         trace_nfs4_map_gid_to_group(buf, ret, id, ret);
 791         return ret;
 792 }