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
  53 #define NFS_UINT_MAXLEN 11
  54
  55 /* Default cache timeout is 10 minutes */
  56 unsigned int nfs_idmap_cache_timeout = 600;
  57 static const struct cred *id_resolver_cache;
  58 static struct key_type key_type_id_resolver_legacy;
  59
  60
  61 /**
  62  * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
  63  * @fattr: fully initialised struct nfs_fattr
  64  * @owner_name: owner name string cache
  65  * @group_name: group name string cache
  66  */
  67 void nfs_fattr_init_names(struct nfs_fattr *fattr,
  68                 struct nfs4_string *owner_name,
  69                 struct nfs4_string *group_name)
  70 {
  71         fattr->owner_name = owner_name;
  72         fattr->group_name = group_name;
  73 }
  74
  75 static void nfs_fattr_free_owner_name(struct nfs_fattr *fattr)
  76 {
  77         fattr->valid &= ~NFS_ATTR_FATTR_OWNER_NAME;
  78         kfree(fattr->owner_name->data);
  79 }
  80
  81 static void nfs_fattr_free_group_name(struct nfs_fattr *fattr)
  82 {
  83         fattr->valid &= ~NFS_ATTR_FATTR_GROUP_NAME;
  84         kfree(fattr->group_name->data);
  85 }
  86
  87 static bool nfs_fattr_map_owner_name(struct nfs_server *server, struct nfs_fattr *fattr)
  88 {
  89         struct nfs4_string *owner = fattr->owner_name;
  90         __u32 uid;
  91
  92         if (!(fattr->valid & NFS_ATTR_FATTR_OWNER_NAME))
  93                 return false;
  94         if (nfs_map_name_to_uid(server, owner->data, owner->len, &uid) == 0) {
  95                 fattr->uid = uid;
  96                 fattr->valid |= NFS_ATTR_FATTR_OWNER;
  97         }
  98         return true;
  99 }
 100
 101 static bool nfs_fattr_map_group_name(struct nfs_server *server, struct nfs_fattr *fattr)
 102 {
 103         struct nfs4_string *group = fattr->group_name;
 104         __u32 gid;
 105
 106         if (!(fattr->valid & NFS_ATTR_FATTR_GROUP_NAME))
 107                 return false;
 108         if (nfs_map_group_to_gid(server, group->data, group->len, &gid) == 0) {
 109                 fattr->gid = gid;
 110                 fattr->valid |= NFS_ATTR_FATTR_GROUP;
 111         }
 112         return true;
 113 }
 114
 115 /**
 116  * nfs_fattr_free_names - free up the NFSv4 owner and group strings
 117  * @fattr: a fully initialised nfs_fattr structure
 118  */
 119 void nfs_fattr_free_names(struct nfs_fattr *fattr)
 120 {
 121         if (fattr->valid & NFS_ATTR_FATTR_OWNER_NAME)
 122                 nfs_fattr_free_owner_name(fattr);
 123         if (fattr->valid & NFS_ATTR_FATTR_GROUP_NAME)
 124                 nfs_fattr_free_group_name(fattr);
 125 }
 126
 127 /**
 128  * nfs_fattr_map_and_free_names - map owner/group strings into uid/gid and free
 129  * @server: pointer to the filesystem nfs_server structure
 130  * @fattr: a fully initialised nfs_fattr structure
 131  *
 132  * This helper maps the cached NFSv4 owner/group strings in fattr into
 133  * their numeric uid/gid equivalents, and then frees the cached strings.
 134  */
 135 void nfs_fattr_map_and_free_names(struct nfs_server *server, struct nfs_fattr *fattr)
 136 {
 137         if (nfs_fattr_map_owner_name(server, fattr))
 138                 nfs_fattr_free_owner_name(fattr);
 139         if (nfs_fattr_map_group_name(server, fattr))
 140                 nfs_fattr_free_group_name(fattr);
 141 }
 142
 143 static int nfs_map_string_to_numeric(const char *name, size_t namelen, __u32 *res)
 144 {
 145         unsigned long val;
 146         char buf[16];
 147
 148         if (memchr(name, '@', namelen) != NULL || namelen >= sizeof(buf))
 149                 return 0;
 150         memcpy(buf, name, namelen);
 151         buf[namelen] = '\0';
 152         if (strict_strtoul(buf, 0, &val) != 0)
 153                 return 0;
 154         *res = val;
 155         return 1;
 156 }
 157
 158 static int nfs_map_numeric_to_string(__u32 id, char *buf, size_t buflen)
 159 {
 160         return snprintf(buf, buflen, "%u", id);
 161 }
 162
 163 static struct key_type key_type_id_resolver = {
 164         .name           = "id_resolver",
 165         .instantiate    = user_instantiate,
 166         .match          = user_match,
 167         .revoke         = user_revoke,
 168         .destroy        = user_destroy,
 169         .describe       = user_describe,
 170         .read           = user_read,
 171 };
 172
 173 static int nfs_idmap_init_keyring(void)
 174 {
 175         struct cred *cred;
 176         struct key *keyring;
 177         int ret = 0;
 178
 179         printk(KERN_NOTICE "NFS: Registering the %s key type\n",
 180                 key_type_id_resolver.name);
 181
 182         cred = prepare_kernel_cred(NULL);
 183         if (!cred)
 184                 return -ENOMEM;
 185
 186         keyring = key_alloc(&key_type_keyring, ".id_resolver", 0, 0, cred,
 187                              (KEY_POS_ALL & ~KEY_POS_SETATTR) |
 188                              KEY_USR_VIEW | KEY_USR_READ,
 189                              KEY_ALLOC_NOT_IN_QUOTA);
 190         if (IS_ERR(keyring)) {
 191                 ret = PTR_ERR(keyring);
 192                 goto failed_put_cred;
 193         }
 194
 195         ret = key_instantiate_and_link(keyring, NULL, 0, NULL, NULL);
 196         if (ret < 0)
 197                 goto failed_put_key;
 198
 199         ret = register_key_type(&key_type_id_resolver);
 200         if (ret < 0)
 201                 goto failed_put_key;
 202
 203         set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
 204         cred->thread_keyring = keyring;
 205         cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
 206         id_resolver_cache = cred;
 207         return 0;
 208
 209 failed_put_key:
 210         key_put(keyring);
 211 failed_put_cred:
 212         put_cred(cred);
 213         return ret;
 214 }
 215
 216 static void nfs_idmap_quit_keyring(void)
 217 {
 218         key_revoke(id_resolver_cache->thread_keyring);
 219         unregister_key_type(&key_type_id_resolver);
 220         put_cred(id_resolver_cache);
 221 }
 222
 223 /*
 224  * Assemble the description to pass to request_key()
 225  * This function will allocate a new string and update dest to point
 226  * at it.  The caller is responsible for freeing dest.
 227  *
 228  * On error 0 is returned.  Otherwise, the length of dest is returned.
 229  */
 230 static ssize_t nfs_idmap_get_desc(const char *name, size_t namelen,
 231                                 const char *type, size_t typelen, char **desc)
 232 {
 233         char *cp;
 234         size_t desclen = typelen + namelen + 2;
 235
 236         *desc = kmalloc(desclen, GFP_KERNEL);
 237         if (!*desc)
 238                 return -ENOMEM;
 239
 240         cp = *desc;
 241         memcpy(cp, type, typelen);
 242         cp += typelen;
 243         *cp++ = ':';
 244
 245         memcpy(cp, name, namelen);
 246         cp += namelen;
 247         *cp = '\0';
 248         return desclen;
 249 }
 250
 251 static ssize_t nfs_idmap_request_key(struct key_type *key_type,
 252                                      const char *name, size_t namelen,
 253                                      const char *type, void *data,
 254                                      size_t data_size, struct idmap *idmap)
 255 {
 256         const struct cred *saved_cred;
 257         struct key *rkey;
 258         char *desc;
 259         struct user_key_payload *payload;
 260         ssize_t ret;
 261
 262         ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
 263         if (ret <= 0)
 264                 goto out;
 265
 266         saved_cred = override_creds(id_resolver_cache);
 267         if (idmap)
 268                 rkey = request_key_with_auxdata(key_type, desc, "", 0, idmap);
 269         else
 270                 rkey = request_key(&key_type_id_resolver, desc, "");
 271         revert_creds(saved_cred);
 272
 273         kfree(desc);
 274         if (IS_ERR(rkey)) {
 275                 ret = PTR_ERR(rkey);
 276                 goto out;
 277         }
 278
 279         rcu_read_lock();
 280         rkey->perm |= KEY_USR_VIEW;
 281
 282         ret = key_validate(rkey);
 283         if (ret < 0)
 284                 goto out_up;
 285
 286         payload = rcu_dereference(rkey->payload.data);
 287         if (IS_ERR_OR_NULL(payload)) {
 288                 ret = PTR_ERR(payload);
 289                 goto out_up;
 290         }
 291
 292         ret = payload->datalen;
 293         if (ret > 0 && ret <= data_size)
 294                 memcpy(data, payload->data, ret);
 295         else
 296                 ret = -EINVAL;
 297
 298 out_up:
 299         rcu_read_unlock();
 300         key_put(rkey);
 301 out:
 302         return ret;
 303 }
 304
 305 static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
 306                                  const char *type, void *data,
 307                                  size_t data_size, struct idmap *idmap)
 308 {
 309         ssize_t ret = nfs_idmap_request_key(&key_type_id_resolver,
 310                                             name, namelen, type, data,
 311                                             data_size, NULL);
 312         if (ret < 0) {
 313                 ret = nfs_idmap_request_key(&key_type_id_resolver_legacy,
 314                                             name, namelen, type, data,
 315                                             data_size, idmap);
 316         }
 317         return ret;
 318 }
 319
 320 /* ID -> Name */
 321 static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf,
 322                                      size_t buflen, struct idmap *idmap)
 323 {
 324         char id_str[NFS_UINT_MAXLEN];
 325         int id_len;
 326         ssize_t ret;
 327
 328         id_len = snprintf(id_str, sizeof(id_str), "%u", id);
 329         ret = nfs_idmap_get_key(id_str, id_len, type, buf, buflen, idmap);
 330         if (ret < 0)
 331                 return -EINVAL;
 332         return ret;
 333 }
 334
 335 /* Name -> ID */
 336 static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *type,
 337                                __u32 *id, struct idmap *idmap)
 338 {
 339         char id_str[NFS_UINT_MAXLEN];
 340         long id_long;
 341         ssize_t data_size;
 342         int ret = 0;
 343
 344         data_size = nfs_idmap_get_key(name, namelen, type, id_str, NFS_UINT_MAXLEN, idmap);
 345         if (data_size <= 0) {
 346                 ret = -EINVAL;
 347         } else {
 348                 ret = strict_strtol(id_str, 10, &id_long);
 349                 *id = (__u32)id_long;
 350         }
 351         return ret;
 352 }
 353
 354 /* idmap classic begins here */
 355 module_param(nfs_idmap_cache_timeout, int, 0644);
 356
 357 struct idmap {
 358         struct rpc_pipe         *idmap_pipe;
 359         struct key_construction *idmap_key_cons;
 360 };
 361
 362 enum {
 363         Opt_find_uid, Opt_find_gid, Opt_find_user, Opt_find_group, Opt_find_err
 364 };
 365
 366 static const match_table_t nfs_idmap_tokens = {
 367         { Opt_find_uid, "uid:%s" },
 368         { Opt_find_gid, "gid:%s" },
 369         { Opt_find_user, "user:%s" },
 370         { Opt_find_group, "group:%s" },
 371         { Opt_find_err, NULL }
 372 };
 373
 374 static int nfs_idmap_legacy_upcall(struct key_construction *, const char *, void *);
 375 static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
 376                                    size_t);
 377 static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
 378
 379 static const struct rpc_pipe_ops idmap_upcall_ops = {
 380         .upcall         = rpc_pipe_generic_upcall,
 381         .downcall       = idmap_pipe_downcall,
 382         .destroy_msg    = idmap_pipe_destroy_msg,
 383 };
 384
 385 static struct key_type key_type_id_resolver_legacy = {
 386         .name           = "id_resolver",
 387         .instantiate    = user_instantiate,
 388         .match          = user_match,
 389         .revoke         = user_revoke,
 390         .destroy        = user_destroy,
 391         .describe       = user_describe,
 392         .read           = user_read,
 393         .request_key    = nfs_idmap_legacy_upcall,
 394 };
 395
 396 static void __nfs_idmap_unregister(struct rpc_pipe *pipe)
 397 {
 398         if (pipe->dentry)
 399                 rpc_unlink(pipe->dentry);
 400 }
 401
 402 static int __nfs_idmap_register(struct dentry *dir,
 403                                      struct idmap *idmap,
 404                                      struct rpc_pipe *pipe)
 405 {
 406         struct dentry *dentry;
 407
 408         dentry = rpc_mkpipe_dentry(dir, "idmap", idmap, pipe);
 409         if (IS_ERR(dentry))
 410                 return PTR_ERR(dentry);
 411         pipe->dentry = dentry;
 412         return 0;
 413 }
 414
 415 static void nfs_idmap_unregister(struct nfs_client *clp,
 416                                       struct rpc_pipe *pipe)
 417 {
 418         struct net *net = clp->net;
 419         struct super_block *pipefs_sb;
 420
 421         pipefs_sb = rpc_get_sb_net(net);
 422         if (pipefs_sb) {
 423                 __nfs_idmap_unregister(pipe);
 424                 rpc_put_sb_net(net);
 425         }
 426 }
 427
 428 static int nfs_idmap_register(struct nfs_client *clp,
 429                                    struct idmap *idmap,
 430                                    struct rpc_pipe *pipe)
 431 {
 432         struct net *net = clp->net;
 433         struct super_block *pipefs_sb;
 434         int err = 0;
 435
 436         pipefs_sb = rpc_get_sb_net(net);
 437         if (pipefs_sb) {
 438                 if (clp->cl_rpcclient->cl_dentry)
 439                         err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
 440                                                    idmap, pipe);
 441                 rpc_put_sb_net(net);
 442         }
 443         return err;
 444 }
 445
 446 int
 447 nfs_idmap_new(struct nfs_client *clp)
 448 {
 449         struct idmap *idmap;
 450         struct rpc_pipe *pipe;
 451         int error;
 452
 453         BUG_ON(clp->cl_idmap != NULL);
 454
 455         idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
 456         if (idmap == NULL)
 457                 return -ENOMEM;
 458
 459         pipe = rpc_mkpipe_data(&idmap_upcall_ops, 0);
 460         if (IS_ERR(pipe)) {
 461                 error = PTR_ERR(pipe);
 462                 kfree(idmap);
 463                 return error;
 464         }
 465         error = nfs_idmap_register(clp, idmap, pipe);
 466         if (error) {
 467                 rpc_destroy_pipe_data(pipe);
 468                 kfree(idmap);
 469                 return error;
 470         }
 471         idmap->idmap_pipe = pipe;
 472
 473         clp->cl_idmap = idmap;
 474         return 0;
 475 }
 476
 477 void
 478 nfs_idmap_delete(struct nfs_client *clp)
 479 {
 480         struct idmap *idmap = clp->cl_idmap;
 481
 482         if (!idmap)
 483                 return;
 484         nfs_idmap_unregister(clp, idmap->idmap_pipe);
 485         rpc_destroy_pipe_data(idmap->idmap_pipe);
 486         clp->cl_idmap = NULL;
 487         kfree(idmap);
 488 }
 489
 490 static int __rpc_pipefs_event(struct nfs_client *clp, unsigned long event,
 491                               struct super_block *sb)
 492 {
 493         int err = 0;
 494
 495         switch (event) {
 496         case RPC_PIPEFS_MOUNT:
 497                 BUG_ON(clp->cl_rpcclient->cl_dentry == NULL);
 498                 err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
 499                                                 clp->cl_idmap,
 500                                                 clp->cl_idmap->idmap_pipe);
 501                 break;
 502         case RPC_PIPEFS_UMOUNT:
 503                 if (clp->cl_idmap->idmap_pipe) {
 504                         struct dentry *parent;
 505
 506                         parent = clp->cl_idmap->idmap_pipe->dentry->d_parent;
 507                         __nfs_idmap_unregister(clp->cl_idmap->idmap_pipe);
 508                         /*
 509                          * Note: This is a dirty hack. SUNRPC hook has been
 510                          * called already but simple_rmdir() call for the
 511                          * directory returned with error because of idmap pipe
 512                          * inside. Thus now we have to remove this directory
 513                          * here.
 514                          */
 515                         if (rpc_rmdir(parent))
 516                                 printk(KERN_ERR "NFS: %s: failed to remove "
 517                                         "clnt dir!\n", __func__);
 518                 }
 519                 break;
 520         default:
 521                 printk(KERN_ERR "NFS: %s: unknown event: %ld\n", __func__,
 522                         event);
 523                 return -ENOTSUPP;
 524         }
 525         return err;
 526 }
 527
 528 static struct nfs_client *nfs_get_client_for_event(struct net *net, int event)
 529 {
 530         struct nfs_net *nn = net_generic(net, nfs_net_id);
 531         struct dentry *cl_dentry;
 532         struct nfs_client *clp;
 533
 534         spin_lock(&nn->nfs_client_lock);
 535         list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
 536                 if (clp->rpc_ops != &nfs_v4_clientops)
 537                         continue;
 538                 cl_dentry = clp->cl_idmap->idmap_pipe->dentry;
 539                 if (((event == RPC_PIPEFS_MOUNT) && cl_dentry) ||
 540                     ((event == RPC_PIPEFS_UMOUNT) && !cl_dentry))
 541                         continue;
 542                 atomic_inc(&clp->cl_count);
 543                 spin_unlock(&nn->nfs_client_lock);
 544                 return clp;
 545         }
 546         spin_unlock(&nn->nfs_client_lock);
 547         return NULL;
 548 }
 549
 550 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 551                             void *ptr)
 552 {
 553         struct super_block *sb = ptr;
 554         struct nfs_client *clp;
 555         int error = 0;
 556
 557         if (!try_module_get(THIS_MODULE))
 558                 return 0;
 559
 560         while ((clp = nfs_get_client_for_event(sb->s_fs_info, event))) {
 561                 error = __rpc_pipefs_event(clp, event, sb);
 562                 nfs_put_client(clp);
 563                 if (error)
 564                         break;
 565         }
 566         module_put(THIS_MODULE);
 567         return error;
 568 }
 569
 570 #define PIPEFS_NFS_PRIO         1
 571
 572 static struct notifier_block nfs_idmap_block = {
 573         .notifier_call  = rpc_pipefs_event,
 574         .priority       = SUNRPC_PIPEFS_NFS_PRIO,
 575 };
 576
 577 int nfs_idmap_init(void)
 578 {
 579         int ret;
 580         ret = nfs_idmap_init_keyring();
 581         if (ret != 0)
 582                 goto out;
 583         ret = rpc_pipefs_notifier_register(&nfs_idmap_block);
 584         if (ret != 0)
 585                 nfs_idmap_quit_keyring();
 586 out:
 587         return ret;
 588 }
 589
 590 void nfs_idmap_quit(void)
 591 {
 592         rpc_pipefs_notifier_unregister(&nfs_idmap_block);
 593         nfs_idmap_quit_keyring();
 594 }
 595
 596 static int nfs_idmap_prepare_message(char *desc, struct idmap_msg *im,
 597                                      struct rpc_pipe_msg *msg)
 598 {
 599         substring_t substr;
 600         int token, ret;
 601
 602         memset(im,  0, sizeof(*im));
 603         memset(msg, 0, sizeof(*msg));
 604
 605         im->im_type = IDMAP_TYPE_GROUP;
 606         token = match_token(desc, nfs_idmap_tokens, &substr);
 607
 608         switch (token) {
 609         case Opt_find_uid:
 610                 im->im_type = IDMAP_TYPE_USER;
 611         case Opt_find_gid:
 612                 im->im_conv = IDMAP_CONV_NAMETOID;
 613                 ret = match_strlcpy(im->im_name, &substr, IDMAP_NAMESZ);
 614                 break;
 615
 616         case Opt_find_user:
 617                 im->im_type = IDMAP_TYPE_USER;
 618         case Opt_find_group:
 619                 im->im_conv = IDMAP_CONV_IDTONAME;
 620                 ret = match_int(&substr, &im->im_id);
 621                 break;
 622
 623         default:
 624                 ret = -EINVAL;
 625                 goto out;
 626         }
 627
 628         msg->data = im;
 629         msg->len  = sizeof(struct idmap_msg);
 630
 631 out:
 632         return ret;
 633 }
 634
 635 static int nfs_idmap_legacy_upcall(struct key_construction *cons,
 636                                    const char *op,
 637                                    void *aux)
 638 {
 639         struct rpc_pipe_msg *msg;
 640         struct idmap_msg *im;
 641         struct idmap *idmap = (struct idmap *)aux;
 642         struct key *key = cons->key;
 643         int ret;
 644
 645         /* msg and im are freed in idmap_pipe_destroy_msg */
 646         msg = kmalloc(sizeof(*msg), GFP_KERNEL);
 647         if (IS_ERR(msg)) {
 648                 ret = PTR_ERR(msg);
 649                 goto out0;
 650         }
 651
 652         im = kmalloc(sizeof(*im), GFP_KERNEL);
 653         if (IS_ERR(im)) {
 654                 ret = PTR_ERR(im);
 655                 goto out1;
 656         }
 657
 658         ret = nfs_idmap_prepare_message(key->description, im, msg);
 659         if (ret < 0)
 660                 goto out2;
 661
 662         idmap->idmap_key_cons = cons;
 663
 664         ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
 665         if (ret < 0)
 666                 goto out2;
 667
 668         return ret;
 669
 670 out2:
 671         kfree(im);
 672 out1:
 673         kfree(msg);
 674 out0:
 675         key_revoke(cons->key);
 676         key_revoke(cons->authkey);
 677         return ret;
 678 }
 679
 680 static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *data)
 681 {
 682         return key_instantiate_and_link(key, data, strlen(data) + 1,
 683                                         id_resolver_cache->thread_keyring,
 684                                         authkey);
 685 }
 686
 687 static int nfs_idmap_read_message(struct idmap_msg *im, struct key *key, struct key *authkey)
 688 {
 689         char id_str[NFS_UINT_MAXLEN];
 690         int ret = -EINVAL;
 691
 692         switch (im->im_conv) {
 693         case IDMAP_CONV_NAMETOID:
 694                 sprintf(id_str, "%d", im->im_id);
 695                 ret = nfs_idmap_instantiate(key, authkey, id_str);
 696                 break;
 697         case IDMAP_CONV_IDTONAME:
 698                 ret = nfs_idmap_instantiate(key, authkey, im->im_name);
 699                 break;
 700         }
 701
 702         return ret;
 703 }
 704
 705 static ssize_t
 706 idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 707 {
 708         struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
 709         struct idmap *idmap = (struct idmap *)rpci->private;
 710         struct key_construction *cons = idmap->idmap_key_cons;
 711         struct idmap_msg im;
 712         size_t namelen_in;
 713         int ret;
 714
 715         if (mlen != sizeof(im)) {
 716                 ret = -ENOSPC;
 717                 goto out;
 718         }
 719
 720         if (copy_from_user(&im, src, mlen) != 0) {
 721                 ret = -EFAULT;
 722                 goto out;
 723         }
 724
 725         if (!(im.im_status & IDMAP_STATUS_SUCCESS)) {
 726                 ret = mlen;
 727                 complete_request_key(idmap->idmap_key_cons, -ENOKEY);
 728                 goto out_incomplete;
 729         }
 730
 731         namelen_in = strnlen(im.im_name, IDMAP_NAMESZ);
 732         if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
 733                 ret = -EINVAL;
 734                 goto out;
 735         }
 736
 737         ret = nfs_idmap_read_message(&im, cons->key, cons->authkey);
 738         if (ret >= 0) {
 739                 key_set_timeout(cons->key, nfs_idmap_cache_timeout);
 740                 ret = mlen;
 741         }
 742
 743 out:
 744         complete_request_key(idmap->idmap_key_cons, ret);
 745 out_incomplete:
 746         return ret;
 747 }
 748
 749 static void
 750 idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 751 {
 752         /* Free memory allocated in nfs_idmap_legacy_upcall() */
 753         kfree(msg->data);
 754         kfree(msg);
 755 }
 756
 757 int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid)
 758 {
 759         struct idmap *idmap = server->nfs_client->cl_idmap;
 760
 761         if (nfs_map_string_to_numeric(name, namelen, uid))
 762                 return 0;
 763         return nfs_idmap_lookup_id(name, namelen, "uid", uid, idmap);
 764 }
 765
 766 int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *gid)
 767 {
 768         struct idmap *idmap = server->nfs_client->cl_idmap;
 769
 770         if (nfs_map_string_to_numeric(name, namelen, gid))
 771                 return 0;
 772         return nfs_idmap_lookup_id(name, namelen, "gid", gid, idmap);
 773 }
 774
 775 int nfs_map_uid_to_name(const struct nfs_server *server, __u32 uid, char *buf, size_t buflen)
 776 {
 777         struct idmap *idmap = server->nfs_client->cl_idmap;
 778         int ret = -EINVAL;
 779
 780         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 781                 ret = nfs_idmap_lookup_name(uid, "user", buf, buflen, idmap);
 782         if (ret < 0)
 783                 ret = nfs_map_numeric_to_string(uid, buf, buflen);
 784         return ret;
 785 }
 786 int nfs_map_gid_to_group(const struct nfs_server *server, __u32 gid, char *buf, size_t buflen)
 787 {
 788         struct idmap *idmap = server->nfs_client->cl_idmap;
 789         int ret = -EINVAL;
 790
 791         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 792                 ret = nfs_idmap_lookup_name(gid, "group", buf, buflen, idmap);
 793         if (ret < 0)
 794                 ret = nfs_map_numeric_to_string(gid, buf, buflen);
 795         return ret;
 796 }