fs/nfs/idmap.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 <linux/nfs_idmap.h>
  40 #include <net/net_namespace.h>
  41 #include <linux/sunrpc/rpc_pipe_fs.h>
  42 #include <linux/nfs_fs.h>
  43 #include <linux/nfs_fs_sb.h>
  44 #include <linux/key.h>
  45 #include <linux/keyctl.h>
  46 #include <linux/key-type.h>
  47 #include <keys/user-type.h>
  48 #include <linux/module.h>
  49
  50 #include "internal.h"
  51 #include "netns.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 static 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
 170 static int nfs_map_numeric_to_string(__u32 id, char *buf, size_t buflen)
 171 {
 172         return snprintf(buf, buflen, "%u", id);
 173 }
 174
 175 static struct key_type key_type_id_resolver = {
 176         .name           = "id_resolver",
 177         .preparse       = user_preparse,
 178         .free_preparse  = user_free_preparse,
 179         .instantiate    = generic_key_instantiate,
 180         .revoke         = user_revoke,
 181         .destroy        = user_destroy,
 182         .describe       = user_describe,
 183         .read           = user_read,
 184 };
 185
 186 static int nfs_idmap_init_keyring(void)
 187 {
 188         struct cred *cred;
 189         struct key *keyring;
 190         int ret = 0;
 191
 192         printk(KERN_NOTICE "NFS: Registering the %s key type\n",
 193                 key_type_id_resolver.name);
 194
 195         cred = prepare_kernel_cred(NULL);
 196         if (!cred)
 197                 return -ENOMEM;
 198
 199         keyring = keyring_alloc(".id_resolver",
 200                                 GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
 201                                 (KEY_POS_ALL & ~KEY_POS_SETATTR) |
 202                                 KEY_USR_VIEW | KEY_USR_READ,
 203                                 KEY_ALLOC_NOT_IN_QUOTA, NULL);
 204         if (IS_ERR(keyring)) {
 205                 ret = PTR_ERR(keyring);
 206                 goto failed_put_cred;
 207         }
 208
 209         ret = register_key_type(&key_type_id_resolver);
 210         if (ret < 0)
 211                 goto failed_put_key;
 212
 213         ret = register_key_type(&key_type_id_resolver_legacy);
 214         if (ret < 0)
 215                 goto failed_reg_legacy;
 216
 217         set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
 218         cred->thread_keyring = keyring;
 219         cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
 220         id_resolver_cache = cred;
 221         return 0;
 222
 223 failed_reg_legacy:
 224         unregister_key_type(&key_type_id_resolver);
 225 failed_put_key:
 226         key_put(keyring);
 227 failed_put_cred:
 228         put_cred(cred);
 229         return ret;
 230 }
 231
 232 static void nfs_idmap_quit_keyring(void)
 233 {
 234         key_revoke(id_resolver_cache->thread_keyring);
 235         unregister_key_type(&key_type_id_resolver);
 236         unregister_key_type(&key_type_id_resolver_legacy);
 237         put_cred(id_resolver_cache);
 238 }
 239
 240 /*
 241  * Assemble the description to pass to request_key()
 242  * This function will allocate a new string and update dest to point
 243  * at it.  The caller is responsible for freeing dest.
 244  *
 245  * On error 0 is returned.  Otherwise, the length of dest is returned.
 246  */
 247 static ssize_t nfs_idmap_get_desc(const char *name, size_t namelen,
 248                                 const char *type, size_t typelen, char **desc)
 249 {
 250         char *cp;
 251         size_t desclen = typelen + namelen + 2;
 252
 253         *desc = kmalloc(desclen, GFP_KERNEL);
 254         if (!*desc)
 255                 return -ENOMEM;
 256
 257         cp = *desc;
 258         memcpy(cp, type, typelen);
 259         cp += typelen;
 260         *cp++ = ':';
 261
 262         memcpy(cp, name, namelen);
 263         cp += namelen;
 264         *cp = '\0';
 265         return desclen;
 266 }
 267
 268 static struct key *nfs_idmap_request_key(const char *name, size_t namelen,
 269                                          const char *type, struct idmap *idmap)
 270 {
 271         char *desc;
 272         struct key *rkey;
 273         ssize_t ret;
 274
 275         ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
 276         if (ret <= 0)
 277                 return ERR_PTR(ret);
 278
 279         rkey = request_key(&key_type_id_resolver, desc, "");
 280         if (IS_ERR(rkey)) {
 281                 mutex_lock(&idmap->idmap_mutex);
 282                 rkey = request_key_with_auxdata(&key_type_id_resolver_legacy,
 283                                                 desc, "", 0, idmap);
 284                 mutex_unlock(&idmap->idmap_mutex);
 285         }
 286         if (!IS_ERR(rkey))
 287                 set_bit(KEY_FLAG_ROOT_CAN_INVAL, &rkey->flags);
 288
 289         kfree(desc);
 290         return rkey;
 291 }
 292
 293 static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
 294                                  const char *type, void *data,
 295                                  size_t data_size, struct idmap *idmap)
 296 {
 297         const struct cred *saved_cred;
 298         struct key *rkey;
 299         struct user_key_payload *payload;
 300         ssize_t ret;
 301
 302         saved_cred = override_creds(id_resolver_cache);
 303         rkey = nfs_idmap_request_key(name, namelen, type, idmap);
 304         revert_creds(saved_cred);
 305
 306         if (IS_ERR(rkey)) {
 307                 ret = PTR_ERR(rkey);
 308                 goto out;
 309         }
 310
 311         rcu_read_lock();
 312         rkey->perm |= KEY_USR_VIEW;
 313
 314         ret = key_validate(rkey);
 315         if (ret < 0)
 316                 goto out_up;
 317
 318         payload = rcu_dereference(rkey->payload.rcudata);
 319         if (IS_ERR_OR_NULL(payload)) {
 320                 ret = PTR_ERR(payload);
 321                 goto out_up;
 322         }
 323
 324         ret = payload->datalen;
 325         if (ret > 0 && ret <= data_size)
 326                 memcpy(data, payload->data, ret);
 327         else
 328                 ret = -EINVAL;
 329
 330 out_up:
 331         rcu_read_unlock();
 332         key_put(rkey);
 333 out:
 334         return ret;
 335 }
 336
 337 /* ID -> Name */
 338 static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf,
 339                                      size_t buflen, struct idmap *idmap)
 340 {
 341         char id_str[NFS_UINT_MAXLEN];
 342         int id_len;
 343         ssize_t ret;
 344
 345         id_len = snprintf(id_str, sizeof(id_str), "%u", id);
 346         ret = nfs_idmap_get_key(id_str, id_len, type, buf, buflen, idmap);
 347         if (ret < 0)
 348                 return -EINVAL;
 349         return ret;
 350 }
 351
 352 /* Name -> ID */
 353 static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *type,
 354                                __u32 *id, struct idmap *idmap)
 355 {
 356         char id_str[NFS_UINT_MAXLEN];
 357         long id_long;
 358         ssize_t data_size;
 359         int ret = 0;
 360
 361         data_size = nfs_idmap_get_key(name, namelen, type, id_str, NFS_UINT_MAXLEN, idmap);
 362         if (data_size <= 0) {
 363                 ret = -EINVAL;
 364         } else {
 365                 ret = kstrtol(id_str, 10, &id_long);
 366                 *id = (__u32)id_long;
 367         }
 368         return ret;
 369 }
 370
 371 /* idmap classic begins here */
 372
 373 enum {
 374         Opt_find_uid, Opt_find_gid, Opt_find_user, Opt_find_group, Opt_find_err
 375 };
 376
 377 static const match_table_t nfs_idmap_tokens = {
 378         { Opt_find_uid, "uid:%s" },
 379         { Opt_find_gid, "gid:%s" },
 380         { Opt_find_user, "user:%s" },
 381         { Opt_find_group, "group:%s" },
 382         { Opt_find_err, NULL }
 383 };
 384
 385 static int nfs_idmap_legacy_upcall(struct key_construction *, const char *, void *);
 386 static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
 387                                    size_t);
 388 static void idmap_release_pipe(struct inode *);
 389 static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
 390
 391 static const struct rpc_pipe_ops idmap_upcall_ops = {
 392         .upcall         = rpc_pipe_generic_upcall,
 393         .downcall       = idmap_pipe_downcall,
 394         .release_pipe   = idmap_release_pipe,
 395         .destroy_msg    = idmap_pipe_destroy_msg,
 396 };
 397
 398 static struct key_type key_type_id_resolver_legacy = {
 399         .name           = "id_legacy",
 400         .preparse       = user_preparse,
 401         .free_preparse  = user_free_preparse,
 402         .instantiate    = generic_key_instantiate,
 403         .revoke         = user_revoke,
 404         .destroy        = user_destroy,
 405         .describe       = user_describe,
 406         .read           = user_read,
 407         .request_key    = nfs_idmap_legacy_upcall,
 408 };
 409
 410 static void nfs_idmap_pipe_destroy(struct dentry *dir,
 411                 struct rpc_pipe_dir_object *pdo)
 412 {
 413         struct idmap *idmap = pdo->pdo_data;
 414         struct rpc_pipe *pipe = idmap->idmap_pipe;
 415
 416         if (pipe->dentry) {
 417                 rpc_unlink(pipe->dentry);
 418                 pipe->dentry = NULL;
 419         }
 420 }
 421
 422 static int nfs_idmap_pipe_create(struct dentry *dir,
 423                 struct rpc_pipe_dir_object *pdo)
 424 {
 425         struct idmap *idmap = pdo->pdo_data;
 426         struct rpc_pipe *pipe = idmap->idmap_pipe;
 427         struct dentry *dentry;
 428
 429         dentry = rpc_mkpipe_dentry(dir, "idmap", idmap, pipe);
 430         if (IS_ERR(dentry))
 431                 return PTR_ERR(dentry);
 432         pipe->dentry = dentry;
 433         return 0;
 434 }
 435
 436 static const struct rpc_pipe_dir_object_ops nfs_idmap_pipe_dir_object_ops = {
 437         .create = nfs_idmap_pipe_create,
 438         .destroy = nfs_idmap_pipe_destroy,
 439 };
 440
 441 int
 442 nfs_idmap_new(struct nfs_client *clp)
 443 {
 444         struct idmap *idmap;
 445         struct rpc_pipe *pipe;
 446         int error;
 447
 448         idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
 449         if (idmap == NULL)
 450                 return -ENOMEM;
 451
 452         rpc_init_pipe_dir_object(&idmap->idmap_pdo,
 453                         &nfs_idmap_pipe_dir_object_ops,
 454                         idmap);
 455
 456         pipe = rpc_mkpipe_data(&idmap_upcall_ops, 0);
 457         if (IS_ERR(pipe)) {
 458                 error = PTR_ERR(pipe);
 459                 goto err;
 460         }
 461         idmap->idmap_pipe = pipe;
 462         mutex_init(&idmap->idmap_mutex);
 463
 464         error = rpc_add_pipe_dir_object(clp->cl_net,
 465                         &clp->cl_rpcclient->cl_pipedir_objects,
 466                         &idmap->idmap_pdo);
 467         if (error)
 468                 goto err_destroy_pipe;
 469
 470         clp->cl_idmap = idmap;
 471         return 0;
 472 err_destroy_pipe:
 473         rpc_destroy_pipe_data(idmap->idmap_pipe);
 474 err:
 475         kfree(idmap);
 476         return error;
 477 }
 478
 479 void
 480 nfs_idmap_delete(struct nfs_client *clp)
 481 {
 482         struct idmap *idmap = clp->cl_idmap;
 483
 484         if (!idmap)
 485                 return;
 486         clp->cl_idmap = NULL;
 487         rpc_remove_pipe_dir_object(clp->cl_net,
 488                         &clp->cl_rpcclient->cl_pipedir_objects,
 489                         &idmap->idmap_pdo);
 490         rpc_destroy_pipe_data(idmap->idmap_pipe);
 491         kfree(idmap);
 492 }
 493
 494 int nfs_idmap_init(void)
 495 {
 496         int ret;
 497         ret = nfs_idmap_init_keyring();
 498         if (ret != 0)
 499                 goto out;
 500 out:
 501         return ret;
 502 }
 503
 504 void nfs_idmap_quit(void)
 505 {
 506         nfs_idmap_quit_keyring();
 507 }
 508
 509 static int nfs_idmap_prepare_message(char *desc, struct idmap *idmap,
 510                                      struct idmap_msg *im,
 511                                      struct rpc_pipe_msg *msg)
 512 {
 513         substring_t substr;
 514         int token, ret;
 515
 516         im->im_type = IDMAP_TYPE_GROUP;
 517         token = match_token(desc, nfs_idmap_tokens, &substr);
 518
 519         switch (token) {
 520         case Opt_find_uid:
 521                 im->im_type = IDMAP_TYPE_USER;
 522         case Opt_find_gid:
 523                 im->im_conv = IDMAP_CONV_NAMETOID;
 524                 ret = match_strlcpy(im->im_name, &substr, IDMAP_NAMESZ);
 525                 break;
 526
 527         case Opt_find_user:
 528                 im->im_type = IDMAP_TYPE_USER;
 529         case Opt_find_group:
 530                 im->im_conv = IDMAP_CONV_IDTONAME;
 531                 ret = match_int(&substr, &im->im_id);
 532                 break;
 533
 534         default:
 535                 ret = -EINVAL;
 536                 goto out;
 537         }
 538
 539         msg->data = im;
 540         msg->len  = sizeof(struct idmap_msg);
 541
 542 out:
 543         return ret;
 544 }
 545
 546 static bool
 547 nfs_idmap_prepare_pipe_upcall(struct idmap *idmap,
 548                 struct idmap_legacy_upcalldata *data)
 549 {
 550         if (idmap->idmap_upcall_data != NULL) {
 551                 WARN_ON_ONCE(1);
 552                 return false;
 553         }
 554         idmap->idmap_upcall_data = data;
 555         return true;
 556 }
 557
 558 static void
 559 nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, int ret)
 560 {
 561         struct key_construction *cons = idmap->idmap_upcall_data->key_cons;
 562
 563         kfree(idmap->idmap_upcall_data);
 564         idmap->idmap_upcall_data = NULL;
 565         complete_request_key(cons, ret);
 566 }
 567
 568 static void
 569 nfs_idmap_abort_pipe_upcall(struct idmap *idmap, int ret)
 570 {
 571         if (idmap->idmap_upcall_data != NULL)
 572                 nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
 573 }
 574
 575 static int nfs_idmap_legacy_upcall(struct key_construction *cons,
 576                                    const char *op,
 577                                    void *aux)
 578 {
 579         struct idmap_legacy_upcalldata *data;
 580         struct rpc_pipe_msg *msg;
 581         struct idmap_msg *im;
 582         struct idmap *idmap = (struct idmap *)aux;
 583         struct key *key = cons->key;
 584         int ret = -ENOMEM;
 585
 586         /* msg and im are freed in idmap_pipe_destroy_msg */
 587         data = kzalloc(sizeof(*data), GFP_KERNEL);
 588         if (!data)
 589                 goto out1;
 590
 591         msg = &data->pipe_msg;
 592         im = &data->idmap_msg;
 593         data->idmap = idmap;
 594         data->key_cons = cons;
 595
 596         ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);
 597         if (ret < 0)
 598                 goto out2;
 599
 600         ret = -EAGAIN;
 601         if (!nfs_idmap_prepare_pipe_upcall(idmap, data))
 602                 goto out2;
 603
 604         ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
 605         if (ret < 0)
 606                 nfs_idmap_abort_pipe_upcall(idmap, ret);
 607
 608         return ret;
 609 out2:
 610         kfree(data);
 611 out1:
 612         complete_request_key(cons, ret);
 613         return ret;
 614 }
 615
 616 static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *data, size_t datalen)
 617 {
 618         return key_instantiate_and_link(key, data, datalen,
 619                                         id_resolver_cache->thread_keyring,
 620                                         authkey);
 621 }
 622
 623 static int nfs_idmap_read_and_verify_message(struct idmap_msg *im,
 624                 struct idmap_msg *upcall,
 625                 struct key *key, struct key *authkey)
 626 {
 627         char id_str[NFS_UINT_MAXLEN];
 628         size_t len;
 629         int ret = -ENOKEY;
 630
 631         /* ret = -ENOKEY */
 632         if (upcall->im_type != im->im_type || upcall->im_conv != im->im_conv)
 633                 goto out;
 634         switch (im->im_conv) {
 635         case IDMAP_CONV_NAMETOID:
 636                 if (strcmp(upcall->im_name, im->im_name) != 0)
 637                         break;
 638                 /* Note: here we store the NUL terminator too */
 639                 len = sprintf(id_str, "%d", im->im_id) + 1;
 640                 ret = nfs_idmap_instantiate(key, authkey, id_str, len);
 641                 break;
 642         case IDMAP_CONV_IDTONAME:
 643                 if (upcall->im_id != im->im_id)
 644                         break;
 645                 len = strlen(im->im_name);
 646                 ret = nfs_idmap_instantiate(key, authkey, im->im_name, len);
 647                 break;
 648         default:
 649                 ret = -EINVAL;
 650         }
 651 out:
 652         return ret;
 653 }
 654
 655 static ssize_t
 656 idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 657 {
 658         struct rpc_inode *rpci = RPC_I(file_inode(filp));
 659         struct idmap *idmap = (struct idmap *)rpci->private;
 660         struct key_construction *cons;
 661         struct idmap_msg im;
 662         size_t namelen_in;
 663         int ret = -ENOKEY;
 664
 665         /* If instantiation is successful, anyone waiting for key construction
 666          * will have been woken up and someone else may now have used
 667          * idmap_key_cons - so after this point we may no longer touch it.
 668          */
 669         if (idmap->idmap_upcall_data == NULL)
 670                 goto out_noupcall;
 671
 672         cons = idmap->idmap_upcall_data->key_cons;
 673
 674         if (mlen != sizeof(im)) {
 675                 ret = -ENOSPC;
 676                 goto out;
 677         }
 678
 679         if (copy_from_user(&im, src, mlen) != 0) {
 680                 ret = -EFAULT;
 681                 goto out;
 682         }
 683
 684         if (!(im.im_status & IDMAP_STATUS_SUCCESS)) {
 685                 ret = -ENOKEY;
 686                 goto out;
 687         }
 688
 689         namelen_in = strnlen(im.im_name, IDMAP_NAMESZ);
 690         if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
 691                 ret = -EINVAL;
 692                 goto out;
 693 }
 694
 695         ret = nfs_idmap_read_and_verify_message(&im,
 696                         &idmap->idmap_upcall_data->idmap_msg,
 697                         cons->key, cons->authkey);
 698         if (ret >= 0) {
 699                 key_set_timeout(cons->key, nfs_idmap_cache_timeout);
 700                 ret = mlen;
 701         }
 702
 703 out:
 704         nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
 705 out_noupcall:
 706         return ret;
 707 }
 708
 709 static void
 710 idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 711 {
 712         struct idmap_legacy_upcalldata *data = container_of(msg,
 713                         struct idmap_legacy_upcalldata,
 714                         pipe_msg);
 715         struct idmap *idmap = data->idmap;
 716
 717         if (msg->errno)
 718                 nfs_idmap_abort_pipe_upcall(idmap, msg->errno);
 719 }
 720
 721 static void
 722 idmap_release_pipe(struct inode *inode)
 723 {
 724         struct rpc_inode *rpci = RPC_I(inode);
 725         struct idmap *idmap = (struct idmap *)rpci->private;
 726
 727         nfs_idmap_abort_pipe_upcall(idmap, -EPIPE);
 728 }
 729
 730 int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, kuid_t *uid)
 731 {
 732         struct idmap *idmap = server->nfs_client->cl_idmap;
 733         __u32 id = -1;
 734         int ret = 0;
 735
 736         if (!nfs_map_string_to_numeric(name, namelen, &id))
 737                 ret = nfs_idmap_lookup_id(name, namelen, "uid", &id, idmap);
 738         if (ret == 0) {
 739                 *uid = make_kuid(&init_user_ns, id);
 740                 if (!uid_valid(*uid))
 741                         ret = -ERANGE;
 742         }
 743         trace_nfs4_map_name_to_uid(name, namelen, id, ret);
 744         return ret;
 745 }
 746
 747 int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, kgid_t *gid)
 748 {
 749         struct idmap *idmap = server->nfs_client->cl_idmap;
 750         __u32 id = -1;
 751         int ret = 0;
 752
 753         if (!nfs_map_string_to_numeric(name, namelen, &id))
 754                 ret = nfs_idmap_lookup_id(name, namelen, "gid", &id, idmap);
 755         if (ret == 0) {
 756                 *gid = make_kgid(&init_user_ns, id);
 757                 if (!gid_valid(*gid))
 758                         ret = -ERANGE;
 759         }
 760         trace_nfs4_map_group_to_gid(name, namelen, id, ret);
 761         return ret;
 762 }
 763
 764 int nfs_map_uid_to_name(const struct nfs_server *server, kuid_t uid, char *buf, size_t buflen)
 765 {
 766         struct idmap *idmap = server->nfs_client->cl_idmap;
 767         int ret = -EINVAL;
 768         __u32 id;
 769
 770         id = from_kuid(&init_user_ns, uid);
 771         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 772                 ret = nfs_idmap_lookup_name(id, "user", buf, buflen, idmap);
 773         if (ret < 0)
 774                 ret = nfs_map_numeric_to_string(id, buf, buflen);
 775         trace_nfs4_map_uid_to_name(buf, ret, id, ret);
 776         return ret;
 777 }
 778 int nfs_map_gid_to_group(const struct nfs_server *server, kgid_t gid, char *buf, size_t buflen)
 779 {
 780         struct idmap *idmap = server->nfs_client->cl_idmap;
 781         int ret = -EINVAL;
 782         __u32 id;
 783
 784         id = from_kgid(&init_user_ns, gid);
 785         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 786                 ret = nfs_idmap_lookup_name(id, "group", buf, buflen, idmap);
 787         if (ret < 0)
 788                 ret = nfs_map_numeric_to_string(id, buf, buflen);
 789         trace_nfs4_map_gid_to_group(buf, ret, id, ret);
 790         return ret;
 791 }