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 /**
  67  * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
  68  * @fattr: fully initialised struct nfs_fattr
  69  * @owner_name: owner name string cache
  70  * @group_name: group name string cache
  71  */
  72 void nfs_fattr_init_names(struct nfs_fattr *fattr,
  73                 struct nfs4_string *owner_name,
  74                 struct nfs4_string *group_name)
  75 {
  76         fattr->owner_name = owner_name;
  77         fattr->group_name = group_name;
  78 }
  79
  80 static void nfs_fattr_free_owner_name(struct nfs_fattr *fattr)
  81 {
  82         fattr->valid &= ~NFS_ATTR_FATTR_OWNER_NAME;
  83         kfree(fattr->owner_name->data);
  84 }
  85
  86 static void nfs_fattr_free_group_name(struct nfs_fattr *fattr)
  87 {
  88         fattr->valid &= ~NFS_ATTR_FATTR_GROUP_NAME;
  89         kfree(fattr->group_name->data);
  90 }
  91
  92 static bool nfs_fattr_map_owner_name(struct nfs_server *server, struct nfs_fattr *fattr)
  93 {
  94         struct nfs4_string *owner = fattr->owner_name;
  95         __u32 uid;
  96
  97         if (!(fattr->valid & NFS_ATTR_FATTR_OWNER_NAME))
  98                 return false;
  99         if (nfs_map_name_to_uid(server, owner->data, owner->len, &uid) == 0) {
 100                 fattr->uid = uid;
 101                 fattr->valid |= NFS_ATTR_FATTR_OWNER;
 102         }
 103         return true;
 104 }
 105
 106 static bool nfs_fattr_map_group_name(struct nfs_server *server, struct nfs_fattr *fattr)
 107 {
 108         struct nfs4_string *group = fattr->group_name;
 109         __u32 gid;
 110
 111         if (!(fattr->valid & NFS_ATTR_FATTR_GROUP_NAME))
 112                 return false;
 113         if (nfs_map_group_to_gid(server, group->data, group->len, &gid) == 0) {
 114                 fattr->gid = gid;
 115                 fattr->valid |= NFS_ATTR_FATTR_GROUP;
 116         }
 117         return true;
 118 }
 119
 120 /**
 121  * nfs_fattr_free_names - free up the NFSv4 owner and group strings
 122  * @fattr: a fully initialised nfs_fattr structure
 123  */
 124 void nfs_fattr_free_names(struct nfs_fattr *fattr)
 125 {
 126         if (fattr->valid & NFS_ATTR_FATTR_OWNER_NAME)
 127                 nfs_fattr_free_owner_name(fattr);
 128         if (fattr->valid & NFS_ATTR_FATTR_GROUP_NAME)
 129                 nfs_fattr_free_group_name(fattr);
 130 }
 131
 132 /**
 133  * nfs_fattr_map_and_free_names - map owner/group strings into uid/gid and free
 134  * @server: pointer to the filesystem nfs_server structure
 135  * @fattr: a fully initialised nfs_fattr structure
 136  *
 137  * This helper maps the cached NFSv4 owner/group strings in fattr into
 138  * their numeric uid/gid equivalents, and then frees the cached strings.
 139  */
 140 void nfs_fattr_map_and_free_names(struct nfs_server *server, struct nfs_fattr *fattr)
 141 {
 142         if (nfs_fattr_map_owner_name(server, fattr))
 143                 nfs_fattr_free_owner_name(fattr);
 144         if (nfs_fattr_map_group_name(server, fattr))
 145                 nfs_fattr_free_group_name(fattr);
 146 }
 147
 148 static int nfs_map_string_to_numeric(const char *name, size_t namelen, __u32 *res)
 149 {
 150         unsigned long val;
 151         char buf[16];
 152
 153         if (memchr(name, '@', namelen) != NULL || namelen >= sizeof(buf))
 154                 return 0;
 155         memcpy(buf, name, namelen);
 156         buf[namelen] = '\0';
 157         if (strict_strtoul(buf, 0, &val) != 0)
 158                 return 0;
 159         *res = val;
 160         return 1;
 161 }
 162
 163 static int nfs_map_numeric_to_string(__u32 id, char *buf, size_t buflen)
 164 {
 165         return snprintf(buf, buflen, "%u", id);
 166 }
 167
 168 static struct key_type key_type_id_resolver = {
 169         .name           = "id_resolver",
 170         .instantiate    = user_instantiate,
 171         .match          = user_match,
 172         .revoke         = user_revoke,
 173         .destroy        = user_destroy,
 174         .describe       = user_describe,
 175         .read           = user_read,
 176 };
 177
 178 static int nfs_idmap_init_keyring(void)
 179 {
 180         struct cred *cred;
 181         struct key *keyring;
 182         int ret = 0;
 183
 184         printk(KERN_NOTICE "NFS: Registering the %s key type\n",
 185                 key_type_id_resolver.name);
 186
 187         cred = prepare_kernel_cred(NULL);
 188         if (!cred)
 189                 return -ENOMEM;
 190
 191         keyring = key_alloc(&key_type_keyring, ".id_resolver", 0, 0, cred,
 192                              (KEY_POS_ALL & ~KEY_POS_SETATTR) |
 193                              KEY_USR_VIEW | KEY_USR_READ,
 194                              KEY_ALLOC_NOT_IN_QUOTA);
 195         if (IS_ERR(keyring)) {
 196                 ret = PTR_ERR(keyring);
 197                 goto failed_put_cred;
 198         }
 199
 200         ret = key_instantiate_and_link(keyring, NULL, 0, NULL, NULL);
 201         if (ret < 0)
 202                 goto failed_put_key;
 203
 204         ret = register_key_type(&key_type_id_resolver);
 205         if (ret < 0)
 206                 goto failed_put_key;
 207
 208         set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
 209         cred->thread_keyring = keyring;
 210         cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
 211         id_resolver_cache = cred;
 212         return 0;
 213
 214 failed_put_key:
 215         key_put(keyring);
 216 failed_put_cred:
 217         put_cred(cred);
 218         return ret;
 219 }
 220
 221 static void nfs_idmap_quit_keyring(void)
 222 {
 223         key_revoke(id_resolver_cache->thread_keyring);
 224         unregister_key_type(&key_type_id_resolver);
 225         put_cred(id_resolver_cache);
 226 }
 227
 228 /*
 229  * Assemble the description to pass to request_key()
 230  * This function will allocate a new string and update dest to point
 231  * at it.  The caller is responsible for freeing dest.
 232  *
 233  * On error 0 is returned.  Otherwise, the length of dest is returned.
 234  */
 235 static ssize_t nfs_idmap_get_desc(const char *name, size_t namelen,
 236                                 const char *type, size_t typelen, char **desc)
 237 {
 238         char *cp;
 239         size_t desclen = typelen + namelen + 2;
 240
 241         *desc = kmalloc(desclen, GFP_KERNEL);
 242         if (!*desc)
 243                 return -ENOMEM;
 244
 245         cp = *desc;
 246         memcpy(cp, type, typelen);
 247         cp += typelen;
 248         *cp++ = ':';
 249
 250         memcpy(cp, name, namelen);
 251         cp += namelen;
 252         *cp = '\0';
 253         return desclen;
 254 }
 255
 256 static ssize_t nfs_idmap_request_key(struct key_type *key_type,
 257                                      const char *name, size_t namelen,
 258                                      const char *type, void *data,
 259                                      size_t data_size, struct idmap *idmap)
 260 {
 261         const struct cred *saved_cred;
 262         struct key *rkey;
 263         char *desc;
 264         struct user_key_payload *payload;
 265         ssize_t ret;
 266
 267         ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
 268         if (ret <= 0)
 269                 goto out;
 270
 271         saved_cred = override_creds(id_resolver_cache);
 272         if (idmap)
 273                 rkey = request_key_with_auxdata(key_type, desc, "", 0, idmap);
 274         else
 275                 rkey = request_key(&key_type_id_resolver, desc, "");
 276         revert_creds(saved_cred);
 277
 278         kfree(desc);
 279         if (IS_ERR(rkey)) {
 280                 ret = PTR_ERR(rkey);
 281                 goto out;
 282         }
 283
 284         rcu_read_lock();
 285         rkey->perm |= KEY_USR_VIEW;
 286
 287         ret = key_validate(rkey);
 288         if (ret < 0)
 289                 goto out_up;
 290
 291         payload = rcu_dereference(rkey->payload.data);
 292         if (IS_ERR_OR_NULL(payload)) {
 293                 ret = PTR_ERR(payload);
 294                 goto out_up;
 295         }
 296
 297         ret = payload->datalen;
 298         if (ret > 0 && ret <= data_size)
 299                 memcpy(data, payload->data, ret);
 300         else
 301                 ret = -EINVAL;
 302
 303 out_up:
 304         rcu_read_unlock();
 305         key_put(rkey);
 306 out:
 307         return ret;
 308 }
 309
 310 static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
 311                                  const char *type, void *data,
 312                                  size_t data_size, struct idmap *idmap)
 313 {
 314         ssize_t ret = nfs_idmap_request_key(&key_type_id_resolver,
 315                                             name, namelen, type, data,
 316                                             data_size, NULL);
 317         if (ret < 0) {
 318                 mutex_lock(&idmap->idmap_mutex);
 319                 ret = nfs_idmap_request_key(&key_type_id_resolver_legacy,
 320                                             name, namelen, type, data,
 321                                             data_size, idmap);
 322                 mutex_unlock(&idmap->idmap_mutex);
 323         }
 324         return ret;
 325 }
 326
 327 /* ID -> Name */
 328 static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf,
 329                                      size_t buflen, struct idmap *idmap)
 330 {
 331         char id_str[NFS_UINT_MAXLEN];
 332         int id_len;
 333         ssize_t ret;
 334
 335         id_len = snprintf(id_str, sizeof(id_str), "%u", id);
 336         ret = nfs_idmap_get_key(id_str, id_len, type, buf, buflen, idmap);
 337         if (ret < 0)
 338                 return -EINVAL;
 339         return ret;
 340 }
 341
 342 /* Name -> ID */
 343 static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *type,
 344                                __u32 *id, struct idmap *idmap)
 345 {
 346         char id_str[NFS_UINT_MAXLEN];
 347         long id_long;
 348         ssize_t data_size;
 349         int ret = 0;
 350
 351         data_size = nfs_idmap_get_key(name, namelen, type, id_str, NFS_UINT_MAXLEN, idmap);
 352         if (data_size <= 0) {
 353                 ret = -EINVAL;
 354         } else {
 355                 ret = strict_strtol(id_str, 10, &id_long);
 356                 *id = (__u32)id_long;
 357         }
 358         return ret;
 359 }
 360
 361 /* idmap classic begins here */
 362 module_param(nfs_idmap_cache_timeout, int, 0644);
 363
 364 enum {
 365         Opt_find_uid, Opt_find_gid, Opt_find_user, Opt_find_group, Opt_find_err
 366 };
 367
 368 static const match_table_t nfs_idmap_tokens = {
 369         { Opt_find_uid, "uid:%s" },
 370         { Opt_find_gid, "gid:%s" },
 371         { Opt_find_user, "user:%s" },
 372         { Opt_find_group, "group:%s" },
 373         { Opt_find_err, NULL }
 374 };
 375
 376 static int nfs_idmap_legacy_upcall(struct key_construction *, const char *, void *);
 377 static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
 378                                    size_t);
 379 static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
 380
 381 static const struct rpc_pipe_ops idmap_upcall_ops = {
 382         .upcall         = rpc_pipe_generic_upcall,
 383         .downcall       = idmap_pipe_downcall,
 384         .destroy_msg    = idmap_pipe_destroy_msg,
 385 };
 386
 387 static struct key_type key_type_id_resolver_legacy = {
 388         .name           = "id_resolver",
 389         .instantiate    = user_instantiate,
 390         .match          = user_match,
 391         .revoke         = user_revoke,
 392         .destroy        = user_destroy,
 393         .describe       = user_describe,
 394         .read           = user_read,
 395         .request_key    = nfs_idmap_legacy_upcall,
 396 };
 397
 398 static void __nfs_idmap_unregister(struct rpc_pipe *pipe)
 399 {
 400         if (pipe->dentry)
 401                 rpc_unlink(pipe->dentry);
 402 }
 403
 404 static int __nfs_idmap_register(struct dentry *dir,
 405                                      struct idmap *idmap,
 406                                      struct rpc_pipe *pipe)
 407 {
 408         struct dentry *dentry;
 409
 410         dentry = rpc_mkpipe_dentry(dir, "idmap", idmap, pipe);
 411         if (IS_ERR(dentry))
 412                 return PTR_ERR(dentry);
 413         pipe->dentry = dentry;
 414         return 0;
 415 }
 416
 417 static void nfs_idmap_unregister(struct nfs_client *clp,
 418                                       struct rpc_pipe *pipe)
 419 {
 420         struct net *net = clp->cl_net;
 421         struct super_block *pipefs_sb;
 422
 423         pipefs_sb = rpc_get_sb_net(net);
 424         if (pipefs_sb) {
 425                 __nfs_idmap_unregister(pipe);
 426                 rpc_put_sb_net(net);
 427         }
 428 }
 429
 430 static int nfs_idmap_register(struct nfs_client *clp,
 431                                    struct idmap *idmap,
 432                                    struct rpc_pipe *pipe)
 433 {
 434         struct net *net = clp->cl_net;
 435         struct super_block *pipefs_sb;
 436         int err = 0;
 437
 438         pipefs_sb = rpc_get_sb_net(net);
 439         if (pipefs_sb) {
 440                 if (clp->cl_rpcclient->cl_dentry)
 441                         err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
 442                                                    idmap, pipe);
 443                 rpc_put_sb_net(net);
 444         }
 445         return err;
 446 }
 447
 448 int
 449 nfs_idmap_new(struct nfs_client *clp)
 450 {
 451         struct idmap *idmap;
 452         struct rpc_pipe *pipe;
 453         int error;
 454
 455         BUG_ON(clp->cl_idmap != NULL);
 456
 457         idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
 458         if (idmap == NULL)
 459                 return -ENOMEM;
 460
 461         pipe = rpc_mkpipe_data(&idmap_upcall_ops, 0);
 462         if (IS_ERR(pipe)) {
 463                 error = PTR_ERR(pipe);
 464                 kfree(idmap);
 465                 return error;
 466         }
 467         error = nfs_idmap_register(clp, idmap, pipe);
 468         if (error) {
 469                 rpc_destroy_pipe_data(pipe);
 470                 kfree(idmap);
 471                 return error;
 472         }
 473         idmap->idmap_pipe = pipe;
 474         mutex_init(&idmap->idmap_mutex);
 475
 476         clp->cl_idmap = idmap;
 477         return 0;
 478 }
 479
 480 void
 481 nfs_idmap_delete(struct nfs_client *clp)
 482 {
 483         struct idmap *idmap = clp->cl_idmap;
 484
 485         if (!idmap)
 486                 return;
 487         nfs_idmap_unregister(clp, idmap->idmap_pipe);
 488         rpc_destroy_pipe_data(idmap->idmap_pipe);
 489         clp->cl_idmap = NULL;
 490         kfree(idmap);
 491 }
 492
 493 static int __rpc_pipefs_event(struct nfs_client *clp, unsigned long event,
 494                               struct super_block *sb)
 495 {
 496         int err = 0;
 497
 498         switch (event) {
 499         case RPC_PIPEFS_MOUNT:
 500                 BUG_ON(clp->cl_rpcclient->cl_dentry == NULL);
 501                 err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
 502                                                 clp->cl_idmap,
 503                                                 clp->cl_idmap->idmap_pipe);
 504                 break;
 505         case RPC_PIPEFS_UMOUNT:
 506                 if (clp->cl_idmap->idmap_pipe) {
 507                         struct dentry *parent;
 508
 509                         parent = clp->cl_idmap->idmap_pipe->dentry->d_parent;
 510                         __nfs_idmap_unregister(clp->cl_idmap->idmap_pipe);
 511                         /*
 512                          * Note: This is a dirty hack. SUNRPC hook has been
 513                          * called already but simple_rmdir() call for the
 514                          * directory returned with error because of idmap pipe
 515                          * inside. Thus now we have to remove this directory
 516                          * here.
 517                          */
 518                         if (rpc_rmdir(parent))
 519                                 printk(KERN_ERR "NFS: %s: failed to remove "
 520                                         "clnt dir!\n", __func__);
 521                 }
 522                 break;
 523         default:
 524                 printk(KERN_ERR "NFS: %s: unknown event: %ld\n", __func__,
 525                         event);
 526                 return -ENOTSUPP;
 527         }
 528         return err;
 529 }
 530
 531 static struct nfs_client *nfs_get_client_for_event(struct net *net, int event)
 532 {
 533         struct nfs_net *nn = net_generic(net, nfs_net_id);
 534         struct dentry *cl_dentry;
 535         struct nfs_client *clp;
 536         int err;
 537
 538 restart:
 539         spin_lock(&nn->nfs_client_lock);
 540         list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
 541                 /* Wait for initialisation to finish */
 542                 if (clp->cl_cons_state == NFS_CS_INITING) {
 543                         atomic_inc(&clp->cl_count);
 544                         spin_unlock(&nn->nfs_client_lock);
 545                         err = nfs_wait_client_init_complete(clp);
 546                         nfs_put_client(clp);
 547                         if (err)
 548                                 return NULL;
 549                         goto restart;
 550                 }
 551                 /* Skip nfs_clients that failed to initialise */
 552                 if (clp->cl_cons_state < 0)
 553                         continue;
 554                 smp_rmb();
 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_msg *im,
 616                                      struct rpc_pipe_msg *msg)
 617 {
 618         substring_t substr;
 619         int token, ret;
 620
 621         memset(im,  0, sizeof(*im));
 622         memset(msg, 0, sizeof(*msg));
 623
 624         im->im_type = IDMAP_TYPE_GROUP;
 625         token = match_token(desc, nfs_idmap_tokens, &substr);
 626
 627         switch (token) {
 628         case Opt_find_uid:
 629                 im->im_type = IDMAP_TYPE_USER;
 630         case Opt_find_gid:
 631                 im->im_conv = IDMAP_CONV_NAMETOID;
 632                 ret = match_strlcpy(im->im_name, &substr, IDMAP_NAMESZ);
 633                 break;
 634
 635         case Opt_find_user:
 636                 im->im_type = IDMAP_TYPE_USER;
 637         case Opt_find_group:
 638                 im->im_conv = IDMAP_CONV_IDTONAME;
 639                 ret = match_int(&substr, &im->im_id);
 640                 break;
 641
 642         default:
 643                 ret = -EINVAL;
 644                 goto out;
 645         }
 646
 647         msg->data = im;
 648         msg->len  = sizeof(struct idmap_msg);
 649
 650 out:
 651         return ret;
 652 }
 653
 654 static int nfs_idmap_legacy_upcall(struct key_construction *cons,
 655                                    const char *op,
 656                                    void *aux)
 657 {
 658         struct rpc_pipe_msg *msg;
 659         struct idmap_msg *im;
 660         struct idmap *idmap = (struct idmap *)aux;
 661         struct key *key = cons->key;
 662         int ret = -ENOMEM;
 663
 664         /* msg and im are freed in idmap_pipe_destroy_msg */
 665         msg = kmalloc(sizeof(*msg), GFP_KERNEL);
 666         if (!msg)
 667                 goto out0;
 668
 669         im = kmalloc(sizeof(*im), GFP_KERNEL);
 670         if (!im)
 671                 goto out1;
 672
 673         ret = nfs_idmap_prepare_message(key->description, im, msg);
 674         if (ret < 0)
 675                 goto out2;
 676
 677         idmap->idmap_key_cons = cons;
 678
 679         ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
 680         if (ret < 0)
 681                 goto out2;
 682
 683         return ret;
 684
 685 out2:
 686         kfree(im);
 687 out1:
 688         kfree(msg);
 689 out0:
 690         key_revoke(cons->key);
 691         key_revoke(cons->authkey);
 692         return ret;
 693 }
 694
 695 static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *data)
 696 {
 697         return key_instantiate_and_link(key, data, strlen(data) + 1,
 698                                         id_resolver_cache->thread_keyring,
 699                                         authkey);
 700 }
 701
 702 static int nfs_idmap_read_message(struct idmap_msg *im, struct key *key, struct key *authkey)
 703 {
 704         char id_str[NFS_UINT_MAXLEN];
 705         int ret = -EINVAL;
 706
 707         switch (im->im_conv) {
 708         case IDMAP_CONV_NAMETOID:
 709                 sprintf(id_str, "%d", im->im_id);
 710                 ret = nfs_idmap_instantiate(key, authkey, id_str);
 711                 break;
 712         case IDMAP_CONV_IDTONAME:
 713                 ret = nfs_idmap_instantiate(key, authkey, im->im_name);
 714                 break;
 715         }
 716
 717         return ret;
 718 }
 719
 720 static ssize_t
 721 idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 722 {
 723         struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
 724         struct idmap *idmap = (struct idmap *)rpci->private;
 725         struct key_construction *cons = idmap->idmap_key_cons;
 726         struct idmap_msg im;
 727         size_t namelen_in;
 728         int ret;
 729
 730         if (mlen != sizeof(im)) {
 731                 ret = -ENOSPC;
 732                 goto out;
 733         }
 734
 735         if (copy_from_user(&im, src, mlen) != 0) {
 736                 ret = -EFAULT;
 737                 goto out;
 738         }
 739
 740         if (!(im.im_status & IDMAP_STATUS_SUCCESS)) {
 741                 ret = mlen;
 742                 complete_request_key(idmap->idmap_key_cons, -ENOKEY);
 743                 goto out_incomplete;
 744         }
 745
 746         namelen_in = strnlen(im.im_name, IDMAP_NAMESZ);
 747         if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
 748                 ret = -EINVAL;
 749                 goto out;
 750         }
 751
 752         ret = nfs_idmap_read_message(&im, cons->key, cons->authkey);
 753         if (ret >= 0) {
 754                 key_set_timeout(cons->key, nfs_idmap_cache_timeout);
 755                 ret = mlen;
 756         }
 757
 758 out:
 759         complete_request_key(idmap->idmap_key_cons, ret);
 760 out_incomplete:
 761         return ret;
 762 }
 763
 764 static void
 765 idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 766 {
 767         /* Free memory allocated in nfs_idmap_legacy_upcall() */
 768         kfree(msg->data);
 769         kfree(msg);
 770 }
 771
 772 int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid)
 773 {
 774         struct idmap *idmap = server->nfs_client->cl_idmap;
 775
 776         if (nfs_map_string_to_numeric(name, namelen, uid))
 777                 return 0;
 778         return nfs_idmap_lookup_id(name, namelen, "uid", uid, idmap);
 779 }
 780
 781 int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *gid)
 782 {
 783         struct idmap *idmap = server->nfs_client->cl_idmap;
 784
 785         if (nfs_map_string_to_numeric(name, namelen, gid))
 786                 return 0;
 787         return nfs_idmap_lookup_id(name, namelen, "gid", gid, idmap);
 788 }
 789
 790 int nfs_map_uid_to_name(const struct nfs_server *server, __u32 uid, char *buf, size_t buflen)
 791 {
 792         struct idmap *idmap = server->nfs_client->cl_idmap;
 793         int ret = -EINVAL;
 794
 795         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 796                 ret = nfs_idmap_lookup_name(uid, "user", buf, buflen, idmap);
 797         if (ret < 0)
 798                 ret = nfs_map_numeric_to_string(uid, buf, buflen);
 799         return ret;
 800 }
 801 int nfs_map_gid_to_group(const struct nfs_server *server, __u32 gid, char *buf, size_t buflen)
 802 {
 803         struct idmap *idmap = server->nfs_client->cl_idmap;
 804         int ret = -EINVAL;
 805
 806         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 807                 ret = nfs_idmap_lookup_name(gid, "group", buf, buflen, idmap);
 808         if (ret < 0)
 809                 ret = nfs_map_numeric_to_string(gid, buf, buflen);
 810         return ret;
 811 }