fs/nfs/nfs4idmap.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 <net/net_namespace.h>
  40 #include <linux/sunrpc/rpc_pipe_fs.h>
  41 #include <linux/nfs_fs.h>
  42 #include <linux/nfs_fs_sb.h>
  43 #include <linux/key.h>
  44 #include <linux/keyctl.h>
  45 #include <linux/key-type.h>
  46 #include <keys/user-type.h>
  47 #include <linux/module.h>
  48
  49 #include "internal.h"
  50 #include "netns.h"
  51 #include "nfs4idmap.h"
  52 #include "nfs4trace.h"
  53
  54 #define NFS_UINT_MAXLEN 11
  55
  56 static const struct cred *id_resolver_cache;
  57 static struct key_type key_type_id_resolver_legacy;
  58
  59 struct idmap_legacy_upcalldata {
  60         struct rpc_pipe_msg pipe_msg;
  61         struct idmap_msg idmap_msg;
  62         struct key_construction *key_cons;
  63         struct idmap *idmap;
  64 };
  65
  66 struct idmap {
  67         struct rpc_pipe_dir_object idmap_pdo;
  68         struct rpc_pipe         *idmap_pipe;
  69         struct idmap_legacy_upcalldata *idmap_upcall_data;
  70         struct mutex            idmap_mutex;
  71 };
  72
  73 /**
  74  * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
  75  * @fattr: fully initialised struct nfs_fattr
  76  * @owner_name: owner name string cache
  77  * @group_name: group name string cache
  78  */
  79 void nfs_fattr_init_names(struct nfs_fattr *fattr,
  80                 struct nfs4_string *owner_name,
  81                 struct nfs4_string *group_name)
  82 {
  83         fattr->owner_name = owner_name;
  84         fattr->group_name = group_name;
  85 }
  86
  87 static void nfs_fattr_free_owner_name(struct nfs_fattr *fattr)
  88 {
  89         fattr->valid &= ~NFS_ATTR_FATTR_OWNER_NAME;
  90         kfree(fattr->owner_name->data);
  91 }
  92
  93 static void nfs_fattr_free_group_name(struct nfs_fattr *fattr)
  94 {
  95         fattr->valid &= ~NFS_ATTR_FATTR_GROUP_NAME;
  96         kfree(fattr->group_name->data);
  97 }
  98
  99 static bool nfs_fattr_map_owner_name(struct nfs_server *server, struct nfs_fattr *fattr)
 100 {
 101         struct nfs4_string *owner = fattr->owner_name;
 102         kuid_t uid;
 103
 104         if (!(fattr->valid & NFS_ATTR_FATTR_OWNER_NAME))
 105                 return false;
 106         if (nfs_map_name_to_uid(server, owner->data, owner->len, &uid) == 0) {
 107                 fattr->uid = uid;
 108                 fattr->valid |= NFS_ATTR_FATTR_OWNER;
 109         }
 110         return true;
 111 }
 112
 113 static bool nfs_fattr_map_group_name(struct nfs_server *server, struct nfs_fattr *fattr)
 114 {
 115         struct nfs4_string *group = fattr->group_name;
 116         kgid_t gid;
 117
 118         if (!(fattr->valid & NFS_ATTR_FATTR_GROUP_NAME))
 119                 return false;
 120         if (nfs_map_group_to_gid(server, group->data, group->len, &gid) == 0) {
 121                 fattr->gid = gid;
 122                 fattr->valid |= NFS_ATTR_FATTR_GROUP;
 123         }
 124         return true;
 125 }
 126
 127 /**
 128  * nfs_fattr_free_names - free up the NFSv4 owner and group strings
 129  * @fattr: a fully initialised nfs_fattr structure
 130  */
 131 void nfs_fattr_free_names(struct nfs_fattr *fattr)
 132 {
 133         if (fattr->valid & NFS_ATTR_FATTR_OWNER_NAME)
 134                 nfs_fattr_free_owner_name(fattr);
 135         if (fattr->valid & NFS_ATTR_FATTR_GROUP_NAME)
 136                 nfs_fattr_free_group_name(fattr);
 137 }
 138
 139 /**
 140  * nfs_fattr_map_and_free_names - map owner/group strings into uid/gid and free
 141  * @server: pointer to the filesystem nfs_server structure
 142  * @fattr: a fully initialised nfs_fattr structure
 143  *
 144  * This helper maps the cached NFSv4 owner/group strings in fattr into
 145  * their numeric uid/gid equivalents, and then frees the cached strings.
 146  */
 147 void nfs_fattr_map_and_free_names(struct nfs_server *server, struct nfs_fattr *fattr)
 148 {
 149         if (nfs_fattr_map_owner_name(server, fattr))
 150                 nfs_fattr_free_owner_name(fattr);
 151         if (nfs_fattr_map_group_name(server, fattr))
 152                 nfs_fattr_free_group_name(fattr);
 153 }
 154
 155 int nfs_map_string_to_numeric(const char *name, size_t namelen, __u32 *res)
 156 {
 157         unsigned long val;
 158         char buf[16];
 159
 160         if (memchr(name, '@', namelen) != NULL || namelen >= sizeof(buf))
 161                 return 0;
 162         memcpy(buf, name, namelen);
 163         buf[namelen] = '\0';
 164         if (kstrtoul(buf, 0, &val) != 0)
 165                 return 0;
 166         *res = val;
 167         return 1;
 168 }
 169 EXPORT_SYMBOL_GPL(nfs_map_string_to_numeric);
 170
 171 static int nfs_map_numeric_to_string(__u32 id, char *buf, size_t buflen)
 172 {
 173         return snprintf(buf, buflen, "%u", id);
 174 }
 175
 176 static struct key_type key_type_id_resolver = {
 177         .name           = "id_resolver",
 178         .preparse       = user_preparse,
 179         .free_preparse  = user_free_preparse,
 180         .instantiate    = generic_key_instantiate,
 181         .revoke         = user_revoke,
 182         .destroy        = user_destroy,
 183         .describe       = user_describe,
 184         .read           = user_read,
 185 };
 186
 187 int nfs_idmap_init(void)
 188 {
 189         struct cred *cred;
 190         struct key *keyring;
 191         int ret = 0;
 192
 193         printk(KERN_NOTICE "NFS: Registering the %s key type\n",
 194                 key_type_id_resolver.name);
 195
 196         cred = prepare_kernel_cred(NULL);
 197         if (!cred)
 198                 return -ENOMEM;
 199
 200         keyring = keyring_alloc(".id_resolver",
 201                                 GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
 202                                 (KEY_POS_ALL & ~KEY_POS_SETATTR) |
 203                                 KEY_USR_VIEW | KEY_USR_READ,
 204                                 KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
 205         if (IS_ERR(keyring)) {
 206                 ret = PTR_ERR(keyring);
 207                 goto failed_put_cred;
 208         }
 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 void nfs_idmap_quit(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 struct key *nfs_idmap_request_key(const char *name, size_t namelen,
 270                                          const char *type, struct idmap *idmap)
 271 {
 272         char *desc;
 273         struct key *rkey;
 274         ssize_t ret;
 275
 276         ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
 277         if (ret < 0)
 278                 return ERR_PTR(ret);
 279
 280         rkey = request_key(&key_type_id_resolver, desc, "");
 281         if (IS_ERR(rkey)) {
 282                 mutex_lock(&idmap->idmap_mutex);
 283                 rkey = request_key_with_auxdata(&key_type_id_resolver_legacy,
 284                                                 desc, "", 0, idmap);
 285                 mutex_unlock(&idmap->idmap_mutex);
 286         }
 287         if (!IS_ERR(rkey))
 288                 set_bit(KEY_FLAG_ROOT_CAN_INVAL, &rkey->flags);
 289
 290         kfree(desc);
 291         return rkey;
 292 }
 293
 294 static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
 295                                  const char *type, void *data,
 296                                  size_t data_size, struct idmap *idmap)
 297 {
 298         const struct cred *saved_cred;
 299         struct key *rkey;
 300         const struct user_key_payload *payload;
 301         ssize_t ret;
 302
 303         saved_cred = override_creds(id_resolver_cache);
 304         rkey = nfs_idmap_request_key(name, namelen, type, idmap);
 305         revert_creds(saved_cred);
 306
 307         if (IS_ERR(rkey)) {
 308                 ret = PTR_ERR(rkey);
 309                 goto out;
 310         }
 311
 312         rcu_read_lock();
 313         rkey->perm |= KEY_USR_VIEW;
 314
 315         ret = key_validate(rkey);
 316         if (ret < 0)
 317                 goto out_up;
 318
 319         payload = user_key_payload_rcu(rkey);
 320         if (IS_ERR_OR_NULL(payload)) {
 321                 ret = PTR_ERR(payload);
 322                 goto out_up;
 323         }
 324
 325         ret = payload->datalen;
 326         if (ret > 0 && ret <= data_size)
 327                 memcpy(data, payload->data, ret);
 328         else
 329                 ret = -EINVAL;
 330
 331 out_up:
 332         rcu_read_unlock();
 333         key_put(rkey);
 334 out:
 335         return ret;
 336 }
 337
 338 /* ID -> Name */
 339 static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf,
 340                                      size_t buflen, struct idmap *idmap)
 341 {
 342         char id_str[NFS_UINT_MAXLEN];
 343         int id_len;
 344         ssize_t ret;
 345
 346         id_len = snprintf(id_str, sizeof(id_str), "%u", id);
 347         ret = nfs_idmap_get_key(id_str, id_len, type, buf, buflen, idmap);
 348         if (ret < 0)
 349                 return -EINVAL;
 350         return ret;
 351 }
 352
 353 /* Name -> ID */
 354 static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *type,
 355                                __u32 *id, struct idmap *idmap)
 356 {
 357         char id_str[NFS_UINT_MAXLEN];
 358         long id_long;
 359         ssize_t data_size;
 360         int ret = 0;
 361
 362         data_size = nfs_idmap_get_key(name, namelen, type, id_str, NFS_UINT_MAXLEN, idmap);
 363         if (data_size <= 0) {
 364                 ret = -EINVAL;
 365         } else {
 366                 ret = kstrtol(id_str, 10, &id_long);
 367                 if (!ret)
 368                         *id = (__u32)id_long;
 369         }
 370         return ret;
 371 }
 372
 373 /* idmap classic begins here */
 374
 375 enum {
 376         Opt_find_uid, Opt_find_gid, Opt_find_user, Opt_find_group, Opt_find_err
 377 };
 378
 379 static const match_table_t nfs_idmap_tokens = {
 380         { Opt_find_uid, "uid:%s" },
 381         { Opt_find_gid, "gid:%s" },
 382         { Opt_find_user, "user:%s" },
 383         { Opt_find_group, "group:%s" },
 384         { Opt_find_err, NULL }
 385 };
 386
 387 static int nfs_idmap_legacy_upcall(struct key_construction *, const char *, void *);
 388 static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
 389                                    size_t);
 390 static void idmap_release_pipe(struct inode *);
 391 static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
 392
 393 static const struct rpc_pipe_ops idmap_upcall_ops = {
 394         .upcall         = rpc_pipe_generic_upcall,
 395         .downcall       = idmap_pipe_downcall,
 396         .release_pipe   = idmap_release_pipe,
 397         .destroy_msg    = idmap_pipe_destroy_msg,
 398 };
 399
 400 static struct key_type key_type_id_resolver_legacy = {
 401         .name           = "id_legacy",
 402         .preparse       = user_preparse,
 403         .free_preparse  = user_free_preparse,
 404         .instantiate    = generic_key_instantiate,
 405         .revoke         = user_revoke,
 406         .destroy        = user_destroy,
 407         .describe       = user_describe,
 408         .read           = user_read,
 409         .request_key    = nfs_idmap_legacy_upcall,
 410 };
 411
 412 static void nfs_idmap_pipe_destroy(struct dentry *dir,
 413                 struct rpc_pipe_dir_object *pdo)
 414 {
 415         struct idmap *idmap = pdo->pdo_data;
 416         struct rpc_pipe *pipe = idmap->idmap_pipe;
 417
 418         if (pipe->dentry) {
 419                 rpc_unlink(pipe->dentry);
 420                 pipe->dentry = NULL;
 421         }
 422 }
 423
 424 static int nfs_idmap_pipe_create(struct dentry *dir,
 425                 struct rpc_pipe_dir_object *pdo)
 426 {
 427         struct idmap *idmap = pdo->pdo_data;
 428         struct rpc_pipe *pipe = idmap->idmap_pipe;
 429         struct dentry *dentry;
 430
 431         dentry = rpc_mkpipe_dentry(dir, "idmap", idmap, pipe);
 432         if (IS_ERR(dentry))
 433                 return PTR_ERR(dentry);
 434         pipe->dentry = dentry;
 435         return 0;
 436 }
 437
 438 static const struct rpc_pipe_dir_object_ops nfs_idmap_pipe_dir_object_ops = {
 439         .create = nfs_idmap_pipe_create,
 440         .destroy = nfs_idmap_pipe_destroy,
 441 };
 442
 443 int
 444 nfs_idmap_new(struct nfs_client *clp)
 445 {
 446         struct idmap *idmap;
 447         struct rpc_pipe *pipe;
 448         int error;
 449
 450         idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
 451         if (idmap == NULL)
 452                 return -ENOMEM;
 453
 454         rpc_init_pipe_dir_object(&idmap->idmap_pdo,
 455                         &nfs_idmap_pipe_dir_object_ops,
 456                         idmap);
 457
 458         pipe = rpc_mkpipe_data(&idmap_upcall_ops, 0);
 459         if (IS_ERR(pipe)) {
 460                 error = PTR_ERR(pipe);
 461                 goto err;
 462         }
 463         idmap->idmap_pipe = pipe;
 464         mutex_init(&idmap->idmap_mutex);
 465
 466         error = rpc_add_pipe_dir_object(clp->cl_net,
 467                         &clp->cl_rpcclient->cl_pipedir_objects,
 468                         &idmap->idmap_pdo);
 469         if (error)
 470                 goto err_destroy_pipe;
 471
 472         clp->cl_idmap = idmap;
 473         return 0;
 474 err_destroy_pipe:
 475         rpc_destroy_pipe_data(idmap->idmap_pipe);
 476 err:
 477         kfree(idmap);
 478         return error;
 479 }
 480
 481 void
 482 nfs_idmap_delete(struct nfs_client *clp)
 483 {
 484         struct idmap *idmap = clp->cl_idmap;
 485
 486         if (!idmap)
 487                 return;
 488         clp->cl_idmap = NULL;
 489         rpc_remove_pipe_dir_object(clp->cl_net,
 490                         &clp->cl_rpcclient->cl_pipedir_objects,
 491                         &idmap->idmap_pdo);
 492         rpc_destroy_pipe_data(idmap->idmap_pipe);
 493         kfree(idmap);
 494 }
 495
 496 static int nfs_idmap_prepare_message(char *desc, struct idmap *idmap,
 497                                      struct idmap_msg *im,
 498                                      struct rpc_pipe_msg *msg)
 499 {
 500         substring_t substr;
 501         int token, ret;
 502
 503         im->im_type = IDMAP_TYPE_GROUP;
 504         token = match_token(desc, nfs_idmap_tokens, &substr);
 505
 506         switch (token) {
 507         case Opt_find_uid:
 508                 im->im_type = IDMAP_TYPE_USER;
 509         case Opt_find_gid:
 510                 im->im_conv = IDMAP_CONV_NAMETOID;
 511                 ret = match_strlcpy(im->im_name, &substr, IDMAP_NAMESZ);
 512                 break;
 513
 514         case Opt_find_user:
 515                 im->im_type = IDMAP_TYPE_USER;
 516         case Opt_find_group:
 517                 im->im_conv = IDMAP_CONV_IDTONAME;
 518                 ret = match_int(&substr, &im->im_id);
 519                 break;
 520
 521         default:
 522                 ret = -EINVAL;
 523                 goto out;
 524         }
 525
 526         msg->data = im;
 527         msg->len  = sizeof(struct idmap_msg);
 528
 529 out:
 530         return ret;
 531 }
 532
 533 static bool
 534 nfs_idmap_prepare_pipe_upcall(struct idmap *idmap,
 535                 struct idmap_legacy_upcalldata *data)
 536 {
 537         if (idmap->idmap_upcall_data != NULL) {
 538                 WARN_ON_ONCE(1);
 539                 return false;
 540         }
 541         idmap->idmap_upcall_data = data;
 542         return true;
 543 }
 544
 545 static void
 546 nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, int ret)
 547 {
 548         struct key_construction *cons = idmap->idmap_upcall_data->key_cons;
 549
 550         kfree(idmap->idmap_upcall_data);
 551         idmap->idmap_upcall_data = NULL;
 552         complete_request_key(cons, ret);
 553 }
 554
 555 static void
 556 nfs_idmap_abort_pipe_upcall(struct idmap *idmap, int ret)
 557 {
 558         if (idmap->idmap_upcall_data != NULL)
 559                 nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
 560 }
 561
 562 static int nfs_idmap_legacy_upcall(struct key_construction *cons,
 563                                    const char *op,
 564                                    void *aux)
 565 {
 566         struct idmap_legacy_upcalldata *data;
 567         struct rpc_pipe_msg *msg;
 568         struct idmap_msg *im;
 569         struct idmap *idmap = (struct idmap *)aux;
 570         struct key *key = cons->key;
 571         int ret = -ENOKEY;
 572
 573         if (!aux)
 574                 goto out1;
 575
 576         /* msg and im are freed in idmap_pipe_destroy_msg */
 577         ret = -ENOMEM;
 578         data = kzalloc(sizeof(*data), GFP_KERNEL);
 579         if (!data)
 580                 goto out1;
 581
 582         msg = &data->pipe_msg;
 583         im = &data->idmap_msg;
 584         data->idmap = idmap;
 585         data->key_cons = cons;
 586
 587         ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);
 588         if (ret < 0)
 589                 goto out2;
 590
 591         ret = -EAGAIN;
 592         if (!nfs_idmap_prepare_pipe_upcall(idmap, data))
 593                 goto out2;
 594
 595         ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
 596         if (ret < 0)
 597                 nfs_idmap_abort_pipe_upcall(idmap, ret);
 598
 599         return ret;
 600 out2:
 601         kfree(data);
 602 out1:
 603         complete_request_key(cons, ret);
 604         return ret;
 605 }
 606
 607 static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *data, size_t datalen)
 608 {
 609         return key_instantiate_and_link(key, data, datalen,
 610                                         id_resolver_cache->thread_keyring,
 611                                         authkey);
 612 }
 613
 614 static int nfs_idmap_read_and_verify_message(struct idmap_msg *im,
 615                 struct idmap_msg *upcall,
 616                 struct key *key, struct key *authkey)
 617 {
 618         char id_str[NFS_UINT_MAXLEN];
 619         size_t len;
 620         int ret = -ENOKEY;
 621
 622         /* ret = -ENOKEY */
 623         if (upcall->im_type != im->im_type || upcall->im_conv != im->im_conv)
 624                 goto out;
 625         switch (im->im_conv) {
 626         case IDMAP_CONV_NAMETOID:
 627                 if (strcmp(upcall->im_name, im->im_name) != 0)
 628                         break;
 629                 /* Note: here we store the NUL terminator too */
 630                 len = sprintf(id_str, "%d", im->im_id) + 1;
 631                 ret = nfs_idmap_instantiate(key, authkey, id_str, len);
 632                 break;
 633         case IDMAP_CONV_IDTONAME:
 634                 if (upcall->im_id != im->im_id)
 635                         break;
 636                 len = strlen(im->im_name);
 637                 ret = nfs_idmap_instantiate(key, authkey, im->im_name, len);
 638                 break;
 639         default:
 640                 ret = -EINVAL;
 641         }
 642 out:
 643         return ret;
 644 }
 645
 646 static ssize_t
 647 idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 648 {
 649         struct rpc_inode *rpci = RPC_I(file_inode(filp));
 650         struct idmap *idmap = (struct idmap *)rpci->private;
 651         struct key_construction *cons;
 652         struct idmap_msg im;
 653         size_t namelen_in;
 654         int ret = -ENOKEY;
 655
 656         /* If instantiation is successful, anyone waiting for key construction
 657          * will have been woken up and someone else may now have used
 658          * idmap_key_cons - so after this point we may no longer touch it.
 659          */
 660         if (idmap->idmap_upcall_data == NULL)
 661                 goto out_noupcall;
 662
 663         cons = idmap->idmap_upcall_data->key_cons;
 664
 665         if (mlen != sizeof(im)) {
 666                 ret = -ENOSPC;
 667                 goto out;
 668         }
 669
 670         if (copy_from_user(&im, src, mlen) != 0) {
 671                 ret = -EFAULT;
 672                 goto out;
 673         }
 674
 675         if (!(im.im_status & IDMAP_STATUS_SUCCESS)) {
 676                 ret = -ENOKEY;
 677                 goto out;
 678         }
 679
 680         namelen_in = strnlen(im.im_name, IDMAP_NAMESZ);
 681         if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
 682                 ret = -EINVAL;
 683                 goto out;
 684 }
 685
 686         ret = nfs_idmap_read_and_verify_message(&im,
 687                         &idmap->idmap_upcall_data->idmap_msg,
 688                         cons->key, cons->authkey);
 689         if (ret >= 0) {
 690                 key_set_timeout(cons->key, nfs_idmap_cache_timeout);
 691                 ret = mlen;
 692         }
 693
 694 out:
 695         nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
 696 out_noupcall:
 697         return ret;
 698 }
 699
 700 static void
 701 idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 702 {
 703         struct idmap_legacy_upcalldata *data = container_of(msg,
 704                         struct idmap_legacy_upcalldata,
 705                         pipe_msg);
 706         struct idmap *idmap = data->idmap;
 707
 708         if (msg->errno)
 709                 nfs_idmap_abort_pipe_upcall(idmap, msg->errno);
 710 }
 711
 712 static void
 713 idmap_release_pipe(struct inode *inode)
 714 {
 715         struct rpc_inode *rpci = RPC_I(inode);
 716         struct idmap *idmap = (struct idmap *)rpci->private;
 717
 718         nfs_idmap_abort_pipe_upcall(idmap, -EPIPE);
 719 }
 720
 721 int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, kuid_t *uid)
 722 {
 723         struct idmap *idmap = server->nfs_client->cl_idmap;
 724         __u32 id = -1;
 725         int ret = 0;
 726
 727         if (!nfs_map_string_to_numeric(name, namelen, &id))
 728                 ret = nfs_idmap_lookup_id(name, namelen, "uid", &id, idmap);
 729         if (ret == 0) {
 730                 *uid = make_kuid(&init_user_ns, id);
 731                 if (!uid_valid(*uid))
 732                         ret = -ERANGE;
 733         }
 734         trace_nfs4_map_name_to_uid(name, namelen, id, ret);
 735         return ret;
 736 }
 737
 738 int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, kgid_t *gid)
 739 {
 740         struct idmap *idmap = server->nfs_client->cl_idmap;
 741         __u32 id = -1;
 742         int ret = 0;
 743
 744         if (!nfs_map_string_to_numeric(name, namelen, &id))
 745                 ret = nfs_idmap_lookup_id(name, namelen, "gid", &id, idmap);
 746         if (ret == 0) {
 747                 *gid = make_kgid(&init_user_ns, id);
 748                 if (!gid_valid(*gid))
 749                         ret = -ERANGE;
 750         }
 751         trace_nfs4_map_group_to_gid(name, namelen, id, ret);
 752         return ret;
 753 }
 754
 755 int nfs_map_uid_to_name(const struct nfs_server *server, kuid_t uid, char *buf, size_t buflen)
 756 {
 757         struct idmap *idmap = server->nfs_client->cl_idmap;
 758         int ret = -EINVAL;
 759         __u32 id;
 760
 761         id = from_kuid(&init_user_ns, uid);
 762         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 763                 ret = nfs_idmap_lookup_name(id, "user", buf, buflen, idmap);
 764         if (ret < 0)
 765                 ret = nfs_map_numeric_to_string(id, buf, buflen);
 766         trace_nfs4_map_uid_to_name(buf, ret, id, ret);
 767         return ret;
 768 }
 769 int nfs_map_gid_to_group(const struct nfs_server *server, kgid_t gid, char *buf, size_t buflen)
 770 {
 771         struct idmap *idmap = server->nfs_client->cl_idmap;
 772         int ret = -EINVAL;
 773         __u32 id;
 774
 775         id = from_kgid(&init_user_ns, gid);
 776         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 777                 ret = nfs_idmap_lookup_name(id, "group", buf, buflen, idmap);
 778         if (ret < 0)
 779                 ret = nfs_map_numeric_to_string(id, buf, buflen);
 780         trace_nfs4_map_gid_to_group(buf, ret, id, ret);
 781         return ret;
 782 }