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 struct idmap {
  61         struct rpc_pipe         *idmap_pipe;
  62         struct key_construction *idmap_key_cons;
  63         struct mutex            idmap_mutex;
  64 };
  65
  66 struct idmap_legacy_upcalldata {
  67         struct rpc_pipe_msg pipe_msg;
  68         struct idmap_msg idmap_msg;
  69         struct idmap *idmap;
  70 };
  71
  72 /**
  73  * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
  74  * @fattr: fully initialised struct nfs_fattr
  75  * @owner_name: owner name string cache
  76  * @group_name: group name string cache
  77  */
  78 void nfs_fattr_init_names(struct nfs_fattr *fattr,
  79                 struct nfs4_string *owner_name,
  80                 struct nfs4_string *group_name)
  81 {
  82         fattr->owner_name = owner_name;
  83         fattr->group_name = group_name;
  84 }
  85
  86 static void nfs_fattr_free_owner_name(struct nfs_fattr *fattr)
  87 {
  88         fattr->valid &= ~NFS_ATTR_FATTR_OWNER_NAME;
  89         kfree(fattr->owner_name->data);
  90 }
  91
  92 static void nfs_fattr_free_group_name(struct nfs_fattr *fattr)
  93 {
  94         fattr->valid &= ~NFS_ATTR_FATTR_GROUP_NAME;
  95         kfree(fattr->group_name->data);
  96 }
  97
  98 static bool nfs_fattr_map_owner_name(struct nfs_server *server, struct nfs_fattr *fattr)
  99 {
 100         struct nfs4_string *owner = fattr->owner_name;
 101         __u32 uid;
 102
 103         if (!(fattr->valid & NFS_ATTR_FATTR_OWNER_NAME))
 104                 return false;
 105         if (nfs_map_name_to_uid(server, owner->data, owner->len, &uid) == 0) {
 106                 fattr->uid = uid;
 107                 fattr->valid |= NFS_ATTR_FATTR_OWNER;
 108         }
 109         return true;
 110 }
 111
 112 static bool nfs_fattr_map_group_name(struct nfs_server *server, struct nfs_fattr *fattr)
 113 {
 114         struct nfs4_string *group = fattr->group_name;
 115         __u32 gid;
 116
 117         if (!(fattr->valid & NFS_ATTR_FATTR_GROUP_NAME))
 118                 return false;
 119         if (nfs_map_group_to_gid(server, group->data, group->len, &gid) == 0) {
 120                 fattr->gid = gid;
 121                 fattr->valid |= NFS_ATTR_FATTR_GROUP;
 122         }
 123         return true;
 124 }
 125
 126 /**
 127  * nfs_fattr_free_names - free up the NFSv4 owner and group strings
 128  * @fattr: a fully initialised nfs_fattr structure
 129  */
 130 void nfs_fattr_free_names(struct nfs_fattr *fattr)
 131 {
 132         if (fattr->valid & NFS_ATTR_FATTR_OWNER_NAME)
 133                 nfs_fattr_free_owner_name(fattr);
 134         if (fattr->valid & NFS_ATTR_FATTR_GROUP_NAME)
 135                 nfs_fattr_free_group_name(fattr);
 136 }
 137
 138 /**
 139  * nfs_fattr_map_and_free_names - map owner/group strings into uid/gid and free
 140  * @server: pointer to the filesystem nfs_server structure
 141  * @fattr: a fully initialised nfs_fattr structure
 142  *
 143  * This helper maps the cached NFSv4 owner/group strings in fattr into
 144  * their numeric uid/gid equivalents, and then frees the cached strings.
 145  */
 146 void nfs_fattr_map_and_free_names(struct nfs_server *server, struct nfs_fattr *fattr)
 147 {
 148         if (nfs_fattr_map_owner_name(server, fattr))
 149                 nfs_fattr_free_owner_name(fattr);
 150         if (nfs_fattr_map_group_name(server, fattr))
 151                 nfs_fattr_free_group_name(fattr);
 152 }
 153
 154 static int nfs_map_string_to_numeric(const char *name, size_t namelen, __u32 *res)
 155 {
 156         unsigned long val;
 157         char buf[16];
 158
 159         if (memchr(name, '@', namelen) != NULL || namelen >= sizeof(buf))
 160                 return 0;
 161         memcpy(buf, name, namelen);
 162         buf[namelen] = '\0';
 163         if (strict_strtoul(buf, 0, &val) != 0)
 164                 return 0;
 165         *res = val;
 166         return 1;
 167 }
 168
 169 static int nfs_map_numeric_to_string(__u32 id, char *buf, size_t buflen)
 170 {
 171         return snprintf(buf, buflen, "%u", id);
 172 }
 173
 174 static struct key_type key_type_id_resolver = {
 175         .name           = "id_resolver",
 176         .instantiate    = user_instantiate,
 177         .match          = user_match,
 178         .revoke         = user_revoke,
 179         .destroy        = user_destroy,
 180         .describe       = user_describe,
 181         .read           = user_read,
 182 };
 183
 184 static int nfs_idmap_init_keyring(void)
 185 {
 186         struct cred *cred;
 187         struct key *keyring;
 188         int ret = 0;
 189
 190         printk(KERN_NOTICE "NFS: Registering the %s key type\n",
 191                 key_type_id_resolver.name);
 192
 193         cred = prepare_kernel_cred(NULL);
 194         if (!cred)
 195                 return -ENOMEM;
 196
 197         keyring = key_alloc(&key_type_keyring, ".id_resolver", 0, 0, cred,
 198                              (KEY_POS_ALL & ~KEY_POS_SETATTR) |
 199                              KEY_USR_VIEW | KEY_USR_READ,
 200                              KEY_ALLOC_NOT_IN_QUOTA);
 201         if (IS_ERR(keyring)) {
 202                 ret = PTR_ERR(keyring);
 203                 goto failed_put_cred;
 204         }
 205
 206         ret = key_instantiate_and_link(keyring, NULL, 0, NULL, NULL);
 207         if (ret < 0)
 208                 goto failed_put_key;
 209
 210         ret = register_key_type(&key_type_id_resolver);
 211         if (ret < 0)
 212                 goto failed_put_key;
 213
 214         ret = register_key_type(&key_type_id_resolver_legacy);
 215         if (ret < 0)
 216                 goto failed_reg_legacy;
 217
 218         set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
 219         cred->thread_keyring = keyring;
 220         cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
 221         id_resolver_cache = cred;
 222         return 0;
 223
 224 failed_reg_legacy:
 225         unregister_key_type(&key_type_id_resolver);
 226 failed_put_key:
 227         key_put(keyring);
 228 failed_put_cred:
 229         put_cred(cred);
 230         return ret;
 231 }
 232
 233 static void nfs_idmap_quit_keyring(void)
 234 {
 235         key_revoke(id_resolver_cache->thread_keyring);
 236         unregister_key_type(&key_type_id_resolver);
 237         unregister_key_type(&key_type_id_resolver_legacy);
 238         put_cred(id_resolver_cache);
 239 }
 240
 241 /*
 242  * Assemble the description to pass to request_key()
 243  * This function will allocate a new string and update dest to point
 244  * at it.  The caller is responsible for freeing dest.
 245  *
 246  * On error 0 is returned.  Otherwise, the length of dest is returned.
 247  */
 248 static ssize_t nfs_idmap_get_desc(const char *name, size_t namelen,
 249                                 const char *type, size_t typelen, char **desc)
 250 {
 251         char *cp;
 252         size_t desclen = typelen + namelen + 2;
 253
 254         *desc = kmalloc(desclen, GFP_KERNEL);
 255         if (!*desc)
 256                 return -ENOMEM;
 257
 258         cp = *desc;
 259         memcpy(cp, type, typelen);
 260         cp += typelen;
 261         *cp++ = ':';
 262
 263         memcpy(cp, name, namelen);
 264         cp += namelen;
 265         *cp = '\0';
 266         return desclen;
 267 }
 268
 269 static ssize_t nfs_idmap_request_key(struct key_type *key_type,
 270                                      const char *name, size_t namelen,
 271                                      const char *type, void *data,
 272                                      size_t data_size, struct idmap *idmap)
 273 {
 274         const struct cred *saved_cred;
 275         struct key *rkey;
 276         char *desc;
 277         struct user_key_payload *payload;
 278         ssize_t ret;
 279
 280         ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
 281         if (ret <= 0)
 282                 goto out;
 283
 284         saved_cred = override_creds(id_resolver_cache);
 285         if (idmap)
 286                 rkey = request_key_with_auxdata(key_type, desc, "", 0, idmap);
 287         else
 288                 rkey = request_key(&key_type_id_resolver, desc, "");
 289         revert_creds(saved_cred);
 290
 291         kfree(desc);
 292         if (IS_ERR(rkey)) {
 293                 ret = PTR_ERR(rkey);
 294                 goto out;
 295         }
 296
 297         rcu_read_lock();
 298         rkey->perm |= KEY_USR_VIEW;
 299
 300         ret = key_validate(rkey);
 301         if (ret < 0)
 302                 goto out_up;
 303
 304         payload = rcu_dereference(rkey->payload.data);
 305         if (IS_ERR_OR_NULL(payload)) {
 306                 ret = PTR_ERR(payload);
 307                 goto out_up;
 308         }
 309
 310         ret = payload->datalen;
 311         if (ret > 0 && ret <= data_size)
 312                 memcpy(data, payload->data, ret);
 313         else
 314                 ret = -EINVAL;
 315
 316 out_up:
 317         rcu_read_unlock();
 318         key_put(rkey);
 319 out:
 320         return ret;
 321 }
 322
 323 static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
 324                                  const char *type, void *data,
 325                                  size_t data_size, struct idmap *idmap)
 326 {
 327         ssize_t ret = nfs_idmap_request_key(&key_type_id_resolver,
 328                                             name, namelen, type, data,
 329                                             data_size, NULL);
 330         if (ret < 0) {
 331                 mutex_lock(&idmap->idmap_mutex);
 332                 ret = nfs_idmap_request_key(&key_type_id_resolver_legacy,
 333                                             name, namelen, type, data,
 334                                             data_size, idmap);
 335                 idmap->idmap_key_cons = NULL;
 336                 mutex_unlock(&idmap->idmap_mutex);
 337         }
 338         return ret;
 339 }
 340
 341 /* ID -> Name */
 342 static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf,
 343                                      size_t buflen, struct idmap *idmap)
 344 {
 345         char id_str[NFS_UINT_MAXLEN];
 346         int id_len;
 347         ssize_t ret;
 348
 349         id_len = snprintf(id_str, sizeof(id_str), "%u", id);
 350         ret = nfs_idmap_get_key(id_str, id_len, type, buf, buflen, idmap);
 351         if (ret < 0)
 352                 return -EINVAL;
 353         return ret;
 354 }
 355
 356 /* Name -> ID */
 357 static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *type,
 358                                __u32 *id, struct idmap *idmap)
 359 {
 360         char id_str[NFS_UINT_MAXLEN];
 361         long id_long;
 362         ssize_t data_size;
 363         int ret = 0;
 364
 365         data_size = nfs_idmap_get_key(name, namelen, type, id_str, NFS_UINT_MAXLEN, idmap);
 366         if (data_size <= 0) {
 367                 ret = -EINVAL;
 368         } else {
 369                 ret = strict_strtol(id_str, 10, &id_long);
 370                 *id = (__u32)id_long;
 371         }
 372         return ret;
 373 }
 374
 375 /* idmap classic begins here */
 376 module_param(nfs_idmap_cache_timeout, int, 0644);
 377
 378 enum {
 379         Opt_find_uid, Opt_find_gid, Opt_find_user, Opt_find_group, Opt_find_err
 380 };
 381
 382 static const match_table_t nfs_idmap_tokens = {
 383         { Opt_find_uid, "uid:%s" },
 384         { Opt_find_gid, "gid:%s" },
 385         { Opt_find_user, "user:%s" },
 386         { Opt_find_group, "group:%s" },
 387         { Opt_find_err, NULL }
 388 };
 389
 390 static int nfs_idmap_legacy_upcall(struct key_construction *, const char *, void *);
 391 static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
 392                                    size_t);
 393 static void idmap_release_pipe(struct inode *);
 394 static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
 395
 396 static const struct rpc_pipe_ops idmap_upcall_ops = {
 397         .upcall         = rpc_pipe_generic_upcall,
 398         .downcall       = idmap_pipe_downcall,
 399         .release_pipe   = idmap_release_pipe,
 400         .destroy_msg    = idmap_pipe_destroy_msg,
 401 };
 402
 403 static struct key_type key_type_id_resolver_legacy = {
 404         .name           = "id_legacy",
 405         .instantiate    = user_instantiate,
 406         .match          = user_match,
 407         .revoke         = user_revoke,
 408         .destroy        = user_destroy,
 409         .describe       = user_describe,
 410         .read           = user_read,
 411         .request_key    = nfs_idmap_legacy_upcall,
 412 };
 413
 414 static void __nfs_idmap_unregister(struct rpc_pipe *pipe)
 415 {
 416         if (pipe->dentry)
 417                 rpc_unlink(pipe->dentry);
 418 }
 419
 420 static int __nfs_idmap_register(struct dentry *dir,
 421                                      struct idmap *idmap,
 422                                      struct rpc_pipe *pipe)
 423 {
 424         struct dentry *dentry;
 425
 426         dentry = rpc_mkpipe_dentry(dir, "idmap", idmap, pipe);
 427         if (IS_ERR(dentry))
 428                 return PTR_ERR(dentry);
 429         pipe->dentry = dentry;
 430         return 0;
 431 }
 432
 433 static void nfs_idmap_unregister(struct nfs_client *clp,
 434                                       struct rpc_pipe *pipe)
 435 {
 436         struct net *net = clp->net;
 437         struct super_block *pipefs_sb;
 438
 439         pipefs_sb = rpc_get_sb_net(net);
 440         if (pipefs_sb) {
 441                 __nfs_idmap_unregister(pipe);
 442                 rpc_put_sb_net(net);
 443         }
 444 }
 445
 446 static int nfs_idmap_register(struct nfs_client *clp,
 447                                    struct idmap *idmap,
 448                                    struct rpc_pipe *pipe)
 449 {
 450         struct net *net = clp->net;
 451         struct super_block *pipefs_sb;
 452         int err = 0;
 453
 454         pipefs_sb = rpc_get_sb_net(net);
 455         if (pipefs_sb) {
 456                 if (clp->cl_rpcclient->cl_dentry)
 457                         err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
 458                                                    idmap, pipe);
 459                 rpc_put_sb_net(net);
 460         }
 461         return err;
 462 }
 463
 464 int
 465 nfs_idmap_new(struct nfs_client *clp)
 466 {
 467         struct idmap *idmap;
 468         struct rpc_pipe *pipe;
 469         int error;
 470
 471         BUG_ON(clp->cl_idmap != NULL);
 472
 473         idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
 474         if (idmap == NULL)
 475                 return -ENOMEM;
 476
 477         pipe = rpc_mkpipe_data(&idmap_upcall_ops, 0);
 478         if (IS_ERR(pipe)) {
 479                 error = PTR_ERR(pipe);
 480                 kfree(idmap);
 481                 return error;
 482         }
 483         error = nfs_idmap_register(clp, idmap, pipe);
 484         if (error) {
 485                 rpc_destroy_pipe_data(pipe);
 486                 kfree(idmap);
 487                 return error;
 488         }
 489         idmap->idmap_pipe = pipe;
 490         mutex_init(&idmap->idmap_mutex);
 491
 492         clp->cl_idmap = idmap;
 493         return 0;
 494 }
 495
 496 void
 497 nfs_idmap_delete(struct nfs_client *clp)
 498 {
 499         struct idmap *idmap = clp->cl_idmap;
 500
 501         if (!idmap)
 502                 return;
 503         nfs_idmap_unregister(clp, idmap->idmap_pipe);
 504         rpc_destroy_pipe_data(idmap->idmap_pipe);
 505         clp->cl_idmap = NULL;
 506         kfree(idmap);
 507 }
 508
 509 static int __rpc_pipefs_event(struct nfs_client *clp, unsigned long event,
 510                               struct super_block *sb)
 511 {
 512         int err = 0;
 513
 514         switch (event) {
 515         case RPC_PIPEFS_MOUNT:
 516                 BUG_ON(clp->cl_rpcclient->cl_dentry == NULL);
 517                 err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
 518                                                 clp->cl_idmap,
 519                                                 clp->cl_idmap->idmap_pipe);
 520                 break;
 521         case RPC_PIPEFS_UMOUNT:
 522                 if (clp->cl_idmap->idmap_pipe) {
 523                         struct dentry *parent;
 524
 525                         parent = clp->cl_idmap->idmap_pipe->dentry->d_parent;
 526                         __nfs_idmap_unregister(clp->cl_idmap->idmap_pipe);
 527                         /*
 528                          * Note: This is a dirty hack. SUNRPC hook has been
 529                          * called already but simple_rmdir() call for the
 530                          * directory returned with error because of idmap pipe
 531                          * inside. Thus now we have to remove this directory
 532                          * here.
 533                          */
 534                         if (rpc_rmdir(parent))
 535                                 printk(KERN_ERR "NFS: %s: failed to remove "
 536                                         "clnt dir!\n", __func__);
 537                 }
 538                 break;
 539         default:
 540                 printk(KERN_ERR "NFS: %s: unknown event: %ld\n", __func__,
 541                         event);
 542                 return -ENOTSUPP;
 543         }
 544         return err;
 545 }
 546
 547 static struct nfs_client *nfs_get_client_for_event(struct net *net, int event)
 548 {
 549         struct nfs_net *nn = net_generic(net, nfs_net_id);
 550         struct dentry *cl_dentry;
 551         struct nfs_client *clp;
 552
 553         spin_lock(&nn->nfs_client_lock);
 554         list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
 555                 if (clp->rpc_ops != &nfs_v4_clientops)
 556                         continue;
 557                 cl_dentry = clp->cl_idmap->idmap_pipe->dentry;
 558                 if (((event == RPC_PIPEFS_MOUNT) && cl_dentry) ||
 559                     ((event == RPC_PIPEFS_UMOUNT) && !cl_dentry))
 560                         continue;
 561                 atomic_inc(&clp->cl_count);
 562                 spin_unlock(&nn->nfs_client_lock);
 563                 return clp;
 564         }
 565         spin_unlock(&nn->nfs_client_lock);
 566         return NULL;
 567 }
 568
 569 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 570                             void *ptr)
 571 {
 572         struct super_block *sb = ptr;
 573         struct nfs_client *clp;
 574         int error = 0;
 575
 576         if (!try_module_get(THIS_MODULE))
 577                 return 0;
 578
 579         while ((clp = nfs_get_client_for_event(sb->s_fs_info, event))) {
 580                 error = __rpc_pipefs_event(clp, event, sb);
 581                 nfs_put_client(clp);
 582                 if (error)
 583                         break;
 584         }
 585         module_put(THIS_MODULE);
 586         return error;
 587 }
 588
 589 #define PIPEFS_NFS_PRIO         1
 590
 591 static struct notifier_block nfs_idmap_block = {
 592         .notifier_call  = rpc_pipefs_event,
 593         .priority       = SUNRPC_PIPEFS_NFS_PRIO,
 594 };
 595
 596 int nfs_idmap_init(void)
 597 {
 598         int ret;
 599         ret = nfs_idmap_init_keyring();
 600         if (ret != 0)
 601                 goto out;
 602         ret = rpc_pipefs_notifier_register(&nfs_idmap_block);
 603         if (ret != 0)
 604                 nfs_idmap_quit_keyring();
 605 out:
 606         return ret;
 607 }
 608
 609 void nfs_idmap_quit(void)
 610 {
 611         rpc_pipefs_notifier_unregister(&nfs_idmap_block);
 612         nfs_idmap_quit_keyring();
 613 }
 614
 615 static int nfs_idmap_prepare_message(char *desc, struct idmap *idmap,
 616                                      struct idmap_msg *im,
 617                                      struct rpc_pipe_msg *msg)
 618 {
 619         substring_t substr;
 620         int token, ret;
 621
 622         memset(im,  0, sizeof(*im));
 623         memset(msg, 0, sizeof(*msg));
 624
 625         im->im_type = IDMAP_TYPE_GROUP;
 626         token = match_token(desc, nfs_idmap_tokens, &substr);
 627
 628         switch (token) {
 629         case Opt_find_uid:
 630                 im->im_type = IDMAP_TYPE_USER;
 631         case Opt_find_gid:
 632                 im->im_conv = IDMAP_CONV_NAMETOID;
 633                 ret = match_strlcpy(im->im_name, &substr, IDMAP_NAMESZ);
 634                 break;
 635
 636         case Opt_find_user:
 637                 im->im_type = IDMAP_TYPE_USER;
 638         case Opt_find_group:
 639                 im->im_conv = IDMAP_CONV_IDTONAME;
 640                 ret = match_int(&substr, &im->im_id);
 641                 break;
 642
 643         default:
 644                 ret = -EINVAL;
 645                 goto out;
 646         }
 647
 648         msg->data = im;
 649         msg->len  = sizeof(struct idmap_msg);
 650
 651 out:
 652         return ret;
 653 }
 654
 655 static int nfs_idmap_legacy_upcall(struct key_construction *cons,
 656                                    const char *op,
 657                                    void *aux)
 658 {
 659         struct idmap_legacy_upcalldata *data;
 660         struct rpc_pipe_msg *msg;
 661         struct idmap_msg *im;
 662         struct idmap *idmap = (struct idmap *)aux;
 663         struct key *key = cons->key;
 664         int ret = -ENOMEM;
 665
 666         /* msg and im are freed in idmap_pipe_destroy_msg */
 667         data = kmalloc(sizeof(*data), GFP_KERNEL);
 668         if (!data)
 669                 goto out1;
 670
 671         msg = &data->pipe_msg;
 672         im = &data->idmap_msg;
 673         data->idmap = idmap;
 674
 675         ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);
 676         if (ret < 0)
 677                 goto out2;
 678
 679         BUG_ON(idmap->idmap_key_cons != NULL);
 680         idmap->idmap_key_cons = cons;
 681
 682         ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
 683         if (ret < 0)
 684                 goto out3;
 685
 686         return ret;
 687
 688 out3:
 689         idmap->idmap_key_cons = NULL;
 690 out2:
 691         kfree(data);
 692 out1:
 693         complete_request_key(cons, ret);
 694         return ret;
 695 }
 696
 697 static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *data)
 698 {
 699         return key_instantiate_and_link(key, data, strlen(data) + 1,
 700                                         id_resolver_cache->thread_keyring,
 701                                         authkey);
 702 }
 703
 704 static int nfs_idmap_read_message(struct idmap_msg *im, struct key *key, struct key *authkey)
 705 {
 706         char id_str[NFS_UINT_MAXLEN];
 707         int ret = -EINVAL;
 708
 709         switch (im->im_conv) {
 710         case IDMAP_CONV_NAMETOID:
 711                 sprintf(id_str, "%d", im->im_id);
 712                 ret = nfs_idmap_instantiate(key, authkey, id_str);
 713                 break;
 714         case IDMAP_CONV_IDTONAME:
 715                 ret = nfs_idmap_instantiate(key, authkey, im->im_name);
 716                 break;
 717         }
 718
 719         return ret;
 720 }
 721
 722 static ssize_t
 723 idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 724 {
 725         struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
 726         struct idmap *idmap = (struct idmap *)rpci->private;
 727         struct key_construction *cons;
 728         struct idmap_msg im;
 729         size_t namelen_in;
 730         int ret;
 731
 732         /* If instantiation is successful, anyone waiting for key construction
 733          * will have been woken up and someone else may now have used
 734          * idmap_key_cons - so after this point we may no longer touch it.
 735          */
 736         cons = ACCESS_ONCE(idmap->idmap_key_cons);
 737         idmap->idmap_key_cons = NULL;
 738
 739         if (mlen != sizeof(im)) {
 740                 ret = -ENOSPC;
 741                 goto out;
 742         }
 743
 744         if (copy_from_user(&im, src, mlen) != 0) {
 745                 ret = -EFAULT;
 746                 goto out;
 747         }
 748
 749         if (!(im.im_status & IDMAP_STATUS_SUCCESS)) {
 750                 ret = mlen;
 751                 complete_request_key(cons, -ENOKEY);
 752                 goto out_incomplete;
 753         }
 754
 755         namelen_in = strnlen(im.im_name, IDMAP_NAMESZ);
 756         if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
 757                 ret = -EINVAL;
 758                 goto out;
 759         }
 760
 761         ret = nfs_idmap_read_message(&im, cons->key, cons->authkey);
 762         if (ret >= 0) {
 763                 key_set_timeout(cons->key, nfs_idmap_cache_timeout);
 764                 ret = mlen;
 765         }
 766
 767 out:
 768         complete_request_key(cons, ret);
 769 out_incomplete:
 770         return ret;
 771 }
 772
 773 static void
 774 idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 775 {
 776         struct idmap_legacy_upcalldata *data = container_of(msg,
 777                         struct idmap_legacy_upcalldata,
 778                         pipe_msg);
 779         struct idmap *idmap = data->idmap;
 780         struct key_construction *cons;
 781         if (msg->errno) {
 782                 cons = ACCESS_ONCE(idmap->idmap_key_cons);
 783                 idmap->idmap_key_cons = NULL;
 784                 complete_request_key(cons, msg->errno);
 785         }
 786         /* Free memory allocated in nfs_idmap_legacy_upcall() */
 787         kfree(data);
 788 }
 789
 790 static void
 791 idmap_release_pipe(struct inode *inode)
 792 {
 793         struct rpc_inode *rpci = RPC_I(inode);
 794         struct idmap *idmap = (struct idmap *)rpci->private;
 795         idmap->idmap_key_cons = NULL;
 796 }
 797
 798 int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid)
 799 {
 800         struct idmap *idmap = server->nfs_client->cl_idmap;
 801
 802         if (nfs_map_string_to_numeric(name, namelen, uid))
 803                 return 0;
 804         return nfs_idmap_lookup_id(name, namelen, "uid", uid, idmap);
 805 }
 806
 807 int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *gid)
 808 {
 809         struct idmap *idmap = server->nfs_client->cl_idmap;
 810
 811         if (nfs_map_string_to_numeric(name, namelen, gid))
 812                 return 0;
 813         return nfs_idmap_lookup_id(name, namelen, "gid", gid, idmap);
 814 }
 815
 816 int nfs_map_uid_to_name(const struct nfs_server *server, __u32 uid, char *buf, size_t buflen)
 817 {
 818         struct idmap *idmap = server->nfs_client->cl_idmap;
 819         int ret = -EINVAL;
 820
 821         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 822                 ret = nfs_idmap_lookup_name(uid, "user", buf, buflen, idmap);
 823         if (ret < 0)
 824                 ret = nfs_map_numeric_to_string(uid, buf, buflen);
 825         return ret;
 826 }
 827 int nfs_map_gid_to_group(const struct nfs_server *server, __u32 gid, char *buf, size_t buflen)
 828 {
 829         struct idmap *idmap = server->nfs_client->cl_idmap;
 830         int ret = -EINVAL;
 831
 832         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 833                 ret = nfs_idmap_lookup_name(gid, "group", buf, buflen, idmap);
 834         if (ret < 0)
 835                 ret = nfs_map_numeric_to_string(gid, buf, buflen);
 836         return ret;
 837 }