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