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