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 static const struct cred *id_resolver_cache;
  56 static struct key_type key_type_id_resolver_legacy;
  57
  58 struct idmap {
  59         struct rpc_pipe         *idmap_pipe;
  60         struct key_construction *idmap_key_cons;
  61         struct mutex            idmap_mutex;
  62 };
  63
  64 struct idmap_legacy_upcalldata {
  65         struct rpc_pipe_msg pipe_msg;
  66         struct idmap_msg idmap_msg;
  67         struct idmap *idmap;
  68 };
  69
  70 /**
  71  * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
  72  * @fattr: fully initialised struct nfs_fattr
  73  * @owner_name: owner name string cache
  74  * @group_name: group name string cache
  75  */
  76 void nfs_fattr_init_names(struct nfs_fattr *fattr,
  77                 struct nfs4_string *owner_name,
  78                 struct nfs4_string *group_name)
  79 {
  80         fattr->owner_name = owner_name;
  81         fattr->group_name = group_name;
  82 }
  83
  84 static void nfs_fattr_free_owner_name(struct nfs_fattr *fattr)
  85 {
  86         fattr->valid &= ~NFS_ATTR_FATTR_OWNER_NAME;
  87         kfree(fattr->owner_name->data);
  88 }
  89
  90 static void nfs_fattr_free_group_name(struct nfs_fattr *fattr)
  91 {
  92         fattr->valid &= ~NFS_ATTR_FATTR_GROUP_NAME;
  93         kfree(fattr->group_name->data);
  94 }
  95
  96 static bool nfs_fattr_map_owner_name(struct nfs_server *server, struct nfs_fattr *fattr)
  97 {
  98         struct nfs4_string *owner = fattr->owner_name;
  99         __u32 uid;
 100
 101         if (!(fattr->valid & NFS_ATTR_FATTR_OWNER_NAME))
 102                 return false;
 103         if (nfs_map_name_to_uid(server, owner->data, owner->len, &uid) == 0) {
 104                 fattr->uid = uid;
 105                 fattr->valid |= NFS_ATTR_FATTR_OWNER;
 106         }
 107         return true;
 108 }
 109
 110 static bool nfs_fattr_map_group_name(struct nfs_server *server, struct nfs_fattr *fattr)
 111 {
 112         struct nfs4_string *group = fattr->group_name;
 113         __u32 gid;
 114
 115         if (!(fattr->valid & NFS_ATTR_FATTR_GROUP_NAME))
 116                 return false;
 117         if (nfs_map_group_to_gid(server, group->data, group->len, &gid) == 0) {
 118                 fattr->gid = gid;
 119                 fattr->valid |= NFS_ATTR_FATTR_GROUP;
 120         }
 121         return true;
 122 }
 123
 124 /**
 125  * nfs_fattr_free_names - free up the NFSv4 owner and group strings
 126  * @fattr: a fully initialised nfs_fattr structure
 127  */
 128 void nfs_fattr_free_names(struct nfs_fattr *fattr)
 129 {
 130         if (fattr->valid & NFS_ATTR_FATTR_OWNER_NAME)
 131                 nfs_fattr_free_owner_name(fattr);
 132         if (fattr->valid & NFS_ATTR_FATTR_GROUP_NAME)
 133                 nfs_fattr_free_group_name(fattr);
 134 }
 135
 136 /**
 137  * nfs_fattr_map_and_free_names - map owner/group strings into uid/gid and free
 138  * @server: pointer to the filesystem nfs_server structure
 139  * @fattr: a fully initialised nfs_fattr structure
 140  *
 141  * This helper maps the cached NFSv4 owner/group strings in fattr into
 142  * their numeric uid/gid equivalents, and then frees the cached strings.
 143  */
 144 void nfs_fattr_map_and_free_names(struct nfs_server *server, struct nfs_fattr *fattr)
 145 {
 146         if (nfs_fattr_map_owner_name(server, fattr))
 147                 nfs_fattr_free_owner_name(fattr);
 148         if (nfs_fattr_map_group_name(server, fattr))
 149                 nfs_fattr_free_group_name(fattr);
 150 }
 151
 152 static int nfs_map_string_to_numeric(const char *name, size_t namelen, __u32 *res)
 153 {
 154         unsigned long val;
 155         char buf[16];
 156
 157         if (memchr(name, '@', namelen) != NULL || namelen >= sizeof(buf))
 158                 return 0;
 159         memcpy(buf, name, namelen);
 160         buf[namelen] = '\0';
 161         if (strict_strtoul(buf, 0, &val) != 0)
 162                 return 0;
 163         *res = val;
 164         return 1;
 165 }
 166
 167 static int nfs_map_numeric_to_string(__u32 id, char *buf, size_t buflen)
 168 {
 169         return snprintf(buf, buflen, "%u", id);
 170 }
 171
 172 static struct key_type key_type_id_resolver = {
 173         .name           = "id_resolver",
 174         .instantiate    = user_instantiate,
 175         .match          = user_match,
 176         .revoke         = user_revoke,
 177         .destroy        = user_destroy,
 178         .describe       = user_describe,
 179         .read           = user_read,
 180 };
 181
 182 static int nfs_idmap_init_keyring(void)
 183 {
 184         struct cred *cred;
 185         struct key *keyring;
 186         int ret = 0;
 187
 188         printk(KERN_NOTICE "NFS: Registering the %s key type\n",
 189                 key_type_id_resolver.name);
 190
 191         cred = prepare_kernel_cred(NULL);
 192         if (!cred)
 193                 return -ENOMEM;
 194
 195         keyring = keyring_alloc(".id_resolver", 0, 0, cred,
 196                                 (KEY_POS_ALL & ~KEY_POS_SETATTR) |
 197                                 KEY_USR_VIEW | KEY_USR_READ,
 198                                 KEY_ALLOC_NOT_IN_QUOTA, NULL);
 199         if (IS_ERR(keyring)) {
 200                 ret = PTR_ERR(keyring);
 201                 goto failed_put_cred;
 202         }
 203
 204         ret = register_key_type(&key_type_id_resolver);
 205         if (ret < 0)
 206                 goto failed_put_key;
 207
 208         ret = register_key_type(&key_type_id_resolver_legacy);
 209         if (ret < 0)
 210                 goto failed_reg_legacy;
 211
 212         set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
 213         cred->thread_keyring = keyring;
 214         cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
 215         id_resolver_cache = cred;
 216         return 0;
 217
 218 failed_reg_legacy:
 219         unregister_key_type(&key_type_id_resolver);
 220 failed_put_key:
 221         key_put(keyring);
 222 failed_put_cred:
 223         put_cred(cred);
 224         return ret;
 225 }
 226
 227 static void nfs_idmap_quit_keyring(void)
 228 {
 229         key_revoke(id_resolver_cache->thread_keyring);
 230         unregister_key_type(&key_type_id_resolver);
 231         unregister_key_type(&key_type_id_resolver_legacy);
 232         put_cred(id_resolver_cache);
 233 }
 234
 235 /*
 236  * Assemble the description to pass to request_key()
 237  * This function will allocate a new string and update dest to point
 238  * at it.  The caller is responsible for freeing dest.
 239  *
 240  * On error 0 is returned.  Otherwise, the length of dest is returned.
 241  */
 242 static ssize_t nfs_idmap_get_desc(const char *name, size_t namelen,
 243                                 const char *type, size_t typelen, char **desc)
 244 {
 245         char *cp;
 246         size_t desclen = typelen + namelen + 2;
 247
 248         *desc = kmalloc(desclen, GFP_KERNEL);
 249         if (!*desc)
 250                 return -ENOMEM;
 251
 252         cp = *desc;
 253         memcpy(cp, type, typelen);
 254         cp += typelen;
 255         *cp++ = ':';
 256
 257         memcpy(cp, name, namelen);
 258         cp += namelen;
 259         *cp = '\0';
 260         return desclen;
 261 }
 262
 263 static ssize_t nfs_idmap_request_key(struct key_type *key_type,
 264                                      const char *name, size_t namelen,
 265                                      const char *type, void *data,
 266                                      size_t data_size, struct idmap *idmap)
 267 {
 268         const struct cred *saved_cred;
 269         struct key *rkey;
 270         char *desc;
 271         struct user_key_payload *payload;
 272         ssize_t ret;
 273
 274         ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
 275         if (ret <= 0)
 276                 goto out;
 277
 278         saved_cred = override_creds(id_resolver_cache);
 279         if (idmap)
 280                 rkey = request_key_with_auxdata(key_type, desc, "", 0, idmap);
 281         else
 282                 rkey = request_key(&key_type_id_resolver, desc, "");
 283         revert_creds(saved_cred);
 284
 285         kfree(desc);
 286         if (IS_ERR(rkey)) {
 287                 ret = PTR_ERR(rkey);
 288                 goto out;
 289         }
 290
 291         rcu_read_lock();
 292         rkey->perm |= KEY_USR_VIEW;
 293
 294         ret = key_validate(rkey);
 295         if (ret < 0)
 296                 goto out_up;
 297
 298         payload = rcu_dereference(rkey->payload.data);
 299         if (IS_ERR_OR_NULL(payload)) {
 300                 ret = PTR_ERR(payload);
 301                 goto out_up;
 302         }
 303
 304         ret = payload->datalen;
 305         if (ret > 0 && ret <= data_size)
 306                 memcpy(data, payload->data, ret);
 307         else
 308                 ret = -EINVAL;
 309
 310 out_up:
 311         rcu_read_unlock();
 312         key_put(rkey);
 313 out:
 314         return ret;
 315 }
 316
 317 static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
 318                                  const char *type, void *data,
 319                                  size_t data_size, struct idmap *idmap)
 320 {
 321         ssize_t ret = nfs_idmap_request_key(&key_type_id_resolver,
 322                                             name, namelen, type, data,
 323                                             data_size, NULL);
 324         if (ret < 0) {
 325                 mutex_lock(&idmap->idmap_mutex);
 326                 ret = nfs_idmap_request_key(&key_type_id_resolver_legacy,
 327                                             name, namelen, type, data,
 328                                             data_size, idmap);
 329                 idmap->idmap_key_cons = NULL;
 330                 mutex_unlock(&idmap->idmap_mutex);
 331         }
 332         return ret;
 333 }
 334
 335 /* ID -> Name */
 336 static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf,
 337                                      size_t buflen, struct idmap *idmap)
 338 {
 339         char id_str[NFS_UINT_MAXLEN];
 340         int id_len;
 341         ssize_t ret;
 342
 343         id_len = snprintf(id_str, sizeof(id_str), "%u", id);
 344         ret = nfs_idmap_get_key(id_str, id_len, type, buf, buflen, idmap);
 345         if (ret < 0)
 346                 return -EINVAL;
 347         return ret;
 348 }
 349
 350 /* Name -> ID */
 351 static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *type,
 352                                __u32 *id, struct idmap *idmap)
 353 {
 354         char id_str[NFS_UINT_MAXLEN];
 355         long id_long;
 356         ssize_t data_size;
 357         int ret = 0;
 358
 359         data_size = nfs_idmap_get_key(name, namelen, type, id_str, NFS_UINT_MAXLEN, idmap);
 360         if (data_size <= 0) {
 361                 ret = -EINVAL;
 362         } else {
 363                 ret = strict_strtol(id_str, 10, &id_long);
 364                 *id = (__u32)id_long;
 365         }
 366         return ret;
 367 }
 368
 369 /* idmap classic begins here */
 370
 371 enum {
 372         Opt_find_uid, Opt_find_gid, Opt_find_user, Opt_find_group, Opt_find_err
 373 };
 374
 375 static const match_table_t nfs_idmap_tokens = {
 376         { Opt_find_uid, "uid:%s" },
 377         { Opt_find_gid, "gid:%s" },
 378         { Opt_find_user, "user:%s" },
 379         { Opt_find_group, "group:%s" },
 380         { Opt_find_err, NULL }
 381 };
 382
 383 static int nfs_idmap_legacy_upcall(struct key_construction *, const char *, void *);
 384 static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
 385                                    size_t);
 386 static void idmap_release_pipe(struct inode *);
 387 static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
 388
 389 static const struct rpc_pipe_ops idmap_upcall_ops = {
 390         .upcall         = rpc_pipe_generic_upcall,
 391         .downcall       = idmap_pipe_downcall,
 392         .release_pipe   = idmap_release_pipe,
 393         .destroy_msg    = idmap_pipe_destroy_msg,
 394 };
 395
 396 static struct key_type key_type_id_resolver_legacy = {
 397         .name           = "id_legacy",
 398         .instantiate    = user_instantiate,
 399         .match          = user_match,
 400         .revoke         = user_revoke,
 401         .destroy        = user_destroy,
 402         .describe       = user_describe,
 403         .read           = user_read,
 404         .request_key    = nfs_idmap_legacy_upcall,
 405 };
 406
 407 static void __nfs_idmap_unregister(struct rpc_pipe *pipe)
 408 {
 409         if (pipe->dentry)
 410                 rpc_unlink(pipe->dentry);
 411 }
 412
 413 static int __nfs_idmap_register(struct dentry *dir,
 414                                      struct idmap *idmap,
 415                                      struct rpc_pipe *pipe)
 416 {
 417         struct dentry *dentry;
 418
 419         dentry = rpc_mkpipe_dentry(dir, "idmap", idmap, pipe);
 420         if (IS_ERR(dentry))
 421                 return PTR_ERR(dentry);
 422         pipe->dentry = dentry;
 423         return 0;
 424 }
 425
 426 static void nfs_idmap_unregister(struct nfs_client *clp,
 427                                       struct rpc_pipe *pipe)
 428 {
 429         struct net *net = clp->cl_net;
 430         struct super_block *pipefs_sb;
 431
 432         pipefs_sb = rpc_get_sb_net(net);
 433         if (pipefs_sb) {
 434                 __nfs_idmap_unregister(pipe);
 435                 rpc_put_sb_net(net);
 436         }
 437 }
 438
 439 static int nfs_idmap_register(struct nfs_client *clp,
 440                                    struct idmap *idmap,
 441                                    struct rpc_pipe *pipe)
 442 {
 443         struct net *net = clp->cl_net;
 444         struct super_block *pipefs_sb;
 445         int err = 0;
 446
 447         pipefs_sb = rpc_get_sb_net(net);
 448         if (pipefs_sb) {
 449                 if (clp->cl_rpcclient->cl_dentry)
 450                         err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
 451                                                    idmap, pipe);
 452                 rpc_put_sb_net(net);
 453         }
 454         return err;
 455 }
 456
 457 int
 458 nfs_idmap_new(struct nfs_client *clp)
 459 {
 460         struct idmap *idmap;
 461         struct rpc_pipe *pipe;
 462         int error;
 463
 464         BUG_ON(clp->cl_idmap != NULL);
 465
 466         idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
 467         if (idmap == NULL)
 468                 return -ENOMEM;
 469
 470         pipe = rpc_mkpipe_data(&idmap_upcall_ops, 0);
 471         if (IS_ERR(pipe)) {
 472                 error = PTR_ERR(pipe);
 473                 kfree(idmap);
 474                 return error;
 475         }
 476         error = nfs_idmap_register(clp, idmap, pipe);
 477         if (error) {
 478                 rpc_destroy_pipe_data(pipe);
 479                 kfree(idmap);
 480                 return error;
 481         }
 482         idmap->idmap_pipe = pipe;
 483         mutex_init(&idmap->idmap_mutex);
 484
 485         clp->cl_idmap = idmap;
 486         return 0;
 487 }
 488
 489 void
 490 nfs_idmap_delete(struct nfs_client *clp)
 491 {
 492         struct idmap *idmap = clp->cl_idmap;
 493
 494         if (!idmap)
 495                 return;
 496         nfs_idmap_unregister(clp, idmap->idmap_pipe);
 497         rpc_destroy_pipe_data(idmap->idmap_pipe);
 498         clp->cl_idmap = NULL;
 499         kfree(idmap);
 500 }
 501
 502 static int __rpc_pipefs_event(struct nfs_client *clp, unsigned long event,
 503                               struct super_block *sb)
 504 {
 505         int err = 0;
 506
 507         switch (event) {
 508         case RPC_PIPEFS_MOUNT:
 509                 BUG_ON(clp->cl_rpcclient->cl_dentry == NULL);
 510                 err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
 511                                                 clp->cl_idmap,
 512                                                 clp->cl_idmap->idmap_pipe);
 513                 break;
 514         case RPC_PIPEFS_UMOUNT:
 515                 if (clp->cl_idmap->idmap_pipe) {
 516                         struct dentry *parent;
 517
 518                         parent = clp->cl_idmap->idmap_pipe->dentry->d_parent;
 519                         __nfs_idmap_unregister(clp->cl_idmap->idmap_pipe);
 520                         /*
 521                          * Note: This is a dirty hack. SUNRPC hook has been
 522                          * called already but simple_rmdir() call for the
 523                          * directory returned with error because of idmap pipe
 524                          * inside. Thus now we have to remove this directory
 525                          * here.
 526                          */
 527                         if (rpc_rmdir(parent))
 528                                 printk(KERN_ERR "NFS: %s: failed to remove "
 529                                         "clnt dir!\n", __func__);
 530                 }
 531                 break;
 532         default:
 533                 printk(KERN_ERR "NFS: %s: unknown event: %ld\n", __func__,
 534                         event);
 535                 return -ENOTSUPP;
 536         }
 537         return err;
 538 }
 539
 540 static struct nfs_client *nfs_get_client_for_event(struct net *net, int event)
 541 {
 542         struct nfs_net *nn = net_generic(net, nfs_net_id);
 543         struct dentry *cl_dentry;
 544         struct nfs_client *clp;
 545         int err;
 546
 547 restart:
 548         spin_lock(&nn->nfs_client_lock);
 549         list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
 550                 /* Wait for initialisation to finish */
 551                 if (clp->cl_cons_state == NFS_CS_INITING) {
 552                         atomic_inc(&clp->cl_count);
 553                         spin_unlock(&nn->nfs_client_lock);
 554                         err = nfs_wait_client_init_complete(clp);
 555                         nfs_put_client(clp);
 556                         if (err)
 557                                 return NULL;
 558                         goto restart;
 559                 }
 560                 /* Skip nfs_clients that failed to initialise */
 561                 if (clp->cl_cons_state < 0)
 562                         continue;
 563                 smp_rmb();
 564                 if (clp->rpc_ops != &nfs_v4_clientops)
 565                         continue;
 566                 cl_dentry = clp->cl_idmap->idmap_pipe->dentry;
 567                 if (((event == RPC_PIPEFS_MOUNT) && cl_dentry) ||
 568                     ((event == RPC_PIPEFS_UMOUNT) && !cl_dentry))
 569                         continue;
 570                 atomic_inc(&clp->cl_count);
 571                 spin_unlock(&nn->nfs_client_lock);
 572                 return clp;
 573         }
 574         spin_unlock(&nn->nfs_client_lock);
 575         return NULL;
 576 }
 577
 578 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 579                             void *ptr)
 580 {
 581         struct super_block *sb = ptr;
 582         struct nfs_client *clp;
 583         int error = 0;
 584
 585         if (!try_module_get(THIS_MODULE))
 586                 return 0;
 587
 588         while ((clp = nfs_get_client_for_event(sb->s_fs_info, event))) {
 589                 error = __rpc_pipefs_event(clp, event, sb);
 590                 nfs_put_client(clp);
 591                 if (error)
 592                         break;
 593         }
 594         module_put(THIS_MODULE);
 595         return error;
 596 }
 597
 598 #define PIPEFS_NFS_PRIO         1
 599
 600 static struct notifier_block nfs_idmap_block = {
 601         .notifier_call  = rpc_pipefs_event,
 602         .priority       = SUNRPC_PIPEFS_NFS_PRIO,
 603 };
 604
 605 int nfs_idmap_init(void)
 606 {
 607         int ret;
 608         ret = nfs_idmap_init_keyring();
 609         if (ret != 0)
 610                 goto out;
 611         ret = rpc_pipefs_notifier_register(&nfs_idmap_block);
 612         if (ret != 0)
 613                 nfs_idmap_quit_keyring();
 614 out:
 615         return ret;
 616 }
 617
 618 void nfs_idmap_quit(void)
 619 {
 620         rpc_pipefs_notifier_unregister(&nfs_idmap_block);
 621         nfs_idmap_quit_keyring();
 622 }
 623
 624 static int nfs_idmap_prepare_message(char *desc, struct idmap *idmap,
 625                                      struct idmap_msg *im,
 626                                      struct rpc_pipe_msg *msg)
 627 {
 628         substring_t substr;
 629         int token, ret;
 630
 631         memset(im,  0, sizeof(*im));
 632         memset(msg, 0, sizeof(*msg));
 633
 634         im->im_type = IDMAP_TYPE_GROUP;
 635         token = match_token(desc, nfs_idmap_tokens, &substr);
 636
 637         switch (token) {
 638         case Opt_find_uid:
 639                 im->im_type = IDMAP_TYPE_USER;
 640         case Opt_find_gid:
 641                 im->im_conv = IDMAP_CONV_NAMETOID;
 642                 ret = match_strlcpy(im->im_name, &substr, IDMAP_NAMESZ);
 643                 break;
 644
 645         case Opt_find_user:
 646                 im->im_type = IDMAP_TYPE_USER;
 647         case Opt_find_group:
 648                 im->im_conv = IDMAP_CONV_IDTONAME;
 649                 ret = match_int(&substr, &im->im_id);
 650                 break;
 651
 652         default:
 653                 ret = -EINVAL;
 654                 goto out;
 655         }
 656
 657         msg->data = im;
 658         msg->len  = sizeof(struct idmap_msg);
 659
 660 out:
 661         return ret;
 662 }
 663
 664 static int nfs_idmap_legacy_upcall(struct key_construction *cons,
 665                                    const char *op,
 666                                    void *aux)
 667 {
 668         struct idmap_legacy_upcalldata *data;
 669         struct rpc_pipe_msg *msg;
 670         struct idmap_msg *im;
 671         struct idmap *idmap = (struct idmap *)aux;
 672         struct key *key = cons->key;
 673         int ret = -ENOMEM;
 674
 675         /* msg and im are freed in idmap_pipe_destroy_msg */
 676         data = kmalloc(sizeof(*data), GFP_KERNEL);
 677         if (!data)
 678                 goto out1;
 679
 680         msg = &data->pipe_msg;
 681         im = &data->idmap_msg;
 682         data->idmap = idmap;
 683
 684         ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);
 685         if (ret < 0)
 686                 goto out2;
 687
 688         BUG_ON(idmap->idmap_key_cons != NULL);
 689         idmap->idmap_key_cons = cons;
 690
 691         ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
 692         if (ret < 0)
 693                 goto out3;
 694
 695         return ret;
 696
 697 out3:
 698         idmap->idmap_key_cons = NULL;
 699 out2:
 700         kfree(data);
 701 out1:
 702         complete_request_key(cons, ret);
 703         return ret;
 704 }
 705
 706 static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *data)
 707 {
 708         return key_instantiate_and_link(key, data, strlen(data) + 1,
 709                                         id_resolver_cache->thread_keyring,
 710                                         authkey);
 711 }
 712
 713 static int nfs_idmap_read_message(struct idmap_msg *im, struct key *key, struct key *authkey)
 714 {
 715         char id_str[NFS_UINT_MAXLEN];
 716         int ret = -EINVAL;
 717
 718         switch (im->im_conv) {
 719         case IDMAP_CONV_NAMETOID:
 720                 sprintf(id_str, "%d", im->im_id);
 721                 ret = nfs_idmap_instantiate(key, authkey, id_str);
 722                 break;
 723         case IDMAP_CONV_IDTONAME:
 724                 ret = nfs_idmap_instantiate(key, authkey, im->im_name);
 725                 break;
 726         }
 727
 728         return ret;
 729 }
 730
 731 static ssize_t
 732 idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 733 {
 734         struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
 735         struct idmap *idmap = (struct idmap *)rpci->private;
 736         struct key_construction *cons;
 737         struct idmap_msg im;
 738         size_t namelen_in;
 739         int ret;
 740
 741         /* If instantiation is successful, anyone waiting for key construction
 742          * will have been woken up and someone else may now have used
 743          * idmap_key_cons - so after this point we may no longer touch it.
 744          */
 745         cons = ACCESS_ONCE(idmap->idmap_key_cons);
 746         idmap->idmap_key_cons = NULL;
 747
 748         if (mlen != sizeof(im)) {
 749                 ret = -ENOSPC;
 750                 goto out;
 751         }
 752
 753         if (copy_from_user(&im, src, mlen) != 0) {
 754                 ret = -EFAULT;
 755                 goto out;
 756         }
 757
 758         if (!(im.im_status & IDMAP_STATUS_SUCCESS)) {
 759                 ret = -ENOKEY;
 760                 goto out;
 761         }
 762
 763         namelen_in = strnlen(im.im_name, IDMAP_NAMESZ);
 764         if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
 765                 ret = -EINVAL;
 766                 goto out;
 767         }
 768
 769         ret = nfs_idmap_read_message(&im, cons->key, cons->authkey);
 770         if (ret >= 0) {
 771                 key_set_timeout(cons->key, nfs_idmap_cache_timeout);
 772                 ret = mlen;
 773         }
 774
 775 out:
 776         complete_request_key(cons, ret);
 777         return ret;
 778 }
 779
 780 static void
 781 idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 782 {
 783         struct idmap_legacy_upcalldata *data = container_of(msg,
 784                         struct idmap_legacy_upcalldata,
 785                         pipe_msg);
 786         struct idmap *idmap = data->idmap;
 787         struct key_construction *cons;
 788         if (msg->errno) {
 789                 cons = ACCESS_ONCE(idmap->idmap_key_cons);
 790                 idmap->idmap_key_cons = NULL;
 791                 complete_request_key(cons, msg->errno);
 792         }
 793         /* Free memory allocated in nfs_idmap_legacy_upcall() */
 794         kfree(data);
 795 }
 796
 797 static void
 798 idmap_release_pipe(struct inode *inode)
 799 {
 800         struct rpc_inode *rpci = RPC_I(inode);
 801         struct idmap *idmap = (struct idmap *)rpci->private;
 802         idmap->idmap_key_cons = NULL;
 803 }
 804
 805 int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid)
 806 {
 807         struct idmap *idmap = server->nfs_client->cl_idmap;
 808
 809         if (nfs_map_string_to_numeric(name, namelen, uid))
 810                 return 0;
 811         return nfs_idmap_lookup_id(name, namelen, "uid", uid, idmap);
 812 }
 813
 814 int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *gid)
 815 {
 816         struct idmap *idmap = server->nfs_client->cl_idmap;
 817
 818         if (nfs_map_string_to_numeric(name, namelen, gid))
 819                 return 0;
 820         return nfs_idmap_lookup_id(name, namelen, "gid", gid, idmap);
 821 }
 822
 823 int nfs_map_uid_to_name(const struct nfs_server *server, __u32 uid, char *buf, size_t buflen)
 824 {
 825         struct idmap *idmap = server->nfs_client->cl_idmap;
 826         int ret = -EINVAL;
 827
 828         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 829                 ret = nfs_idmap_lookup_name(uid, "user", buf, buflen, idmap);
 830         if (ret < 0)
 831                 ret = nfs_map_numeric_to_string(uid, buf, buflen);
 832         return ret;
 833 }
 834 int nfs_map_gid_to_group(const struct nfs_server *server, __u32 gid, char *buf, size_t buflen)
 835 {
 836         struct idmap *idmap = server->nfs_client->cl_idmap;
 837         int ret = -EINVAL;
 838
 839         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 840                 ret = nfs_idmap_lookup_name(gid, "group", buf, buflen, idmap);
 841         if (ret < 0)
 842                 ret = nfs_map_numeric_to_string(gid, buf, buflen);
 843         return ret;
 844 }