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_legacy_upcalldata {
  59         struct rpc_pipe_msg pipe_msg;
  60         struct idmap_msg idmap_msg;
  61         struct key_construction *key_cons;
  62         struct idmap *idmap;
  63 };
  64
  65 struct idmap {
  66         struct rpc_pipe         *idmap_pipe;
  67         struct idmap_legacy_upcalldata *idmap_upcall_data;
  68         struct mutex            idmap_mutex;
  69 };
  70
  71 /**
  72  * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
  73  * @fattr: fully initialised struct nfs_fattr
  74  * @owner_name: owner name string cache
  75  * @group_name: group name string cache
  76  */
  77 void nfs_fattr_init_names(struct nfs_fattr *fattr,
  78                 struct nfs4_string *owner_name,
  79                 struct nfs4_string *group_name)
  80 {
  81         fattr->owner_name = owner_name;
  82         fattr->group_name = group_name;
  83 }
  84
  85 static void nfs_fattr_free_owner_name(struct nfs_fattr *fattr)
  86 {
  87         fattr->valid &= ~NFS_ATTR_FATTR_OWNER_NAME;
  88         kfree(fattr->owner_name->data);
  89 }
  90
  91 static void nfs_fattr_free_group_name(struct nfs_fattr *fattr)
  92 {
  93         fattr->valid &= ~NFS_ATTR_FATTR_GROUP_NAME;
  94         kfree(fattr->group_name->data);
  95 }
  96
  97 static bool nfs_fattr_map_owner_name(struct nfs_server *server, struct nfs_fattr *fattr)
  98 {
  99         struct nfs4_string *owner = fattr->owner_name;
 100         __u32 uid;
 101
 102         if (!(fattr->valid & NFS_ATTR_FATTR_OWNER_NAME))
 103                 return false;
 104         if (nfs_map_name_to_uid(server, owner->data, owner->len, &uid) == 0) {
 105                 fattr->uid = uid;
 106                 fattr->valid |= NFS_ATTR_FATTR_OWNER;
 107         }
 108         return true;
 109 }
 110
 111 static bool nfs_fattr_map_group_name(struct nfs_server *server, struct nfs_fattr *fattr)
 112 {
 113         struct nfs4_string *group = fattr->group_name;
 114         __u32 gid;
 115
 116         if (!(fattr->valid & NFS_ATTR_FATTR_GROUP_NAME))
 117                 return false;
 118         if (nfs_map_group_to_gid(server, group->data, group->len, &gid) == 0) {
 119                 fattr->gid = gid;
 120                 fattr->valid |= NFS_ATTR_FATTR_GROUP;
 121         }
 122         return true;
 123 }
 124
 125 /**
 126  * nfs_fattr_free_names - free up the NFSv4 owner and group strings
 127  * @fattr: a fully initialised nfs_fattr structure
 128  */
 129 void nfs_fattr_free_names(struct nfs_fattr *fattr)
 130 {
 131         if (fattr->valid & NFS_ATTR_FATTR_OWNER_NAME)
 132                 nfs_fattr_free_owner_name(fattr);
 133         if (fattr->valid & NFS_ATTR_FATTR_GROUP_NAME)
 134                 nfs_fattr_free_group_name(fattr);
 135 }
 136
 137 /**
 138  * nfs_fattr_map_and_free_names - map owner/group strings into uid/gid and free
 139  * @server: pointer to the filesystem nfs_server structure
 140  * @fattr: a fully initialised nfs_fattr structure
 141  *
 142  * This helper maps the cached NFSv4 owner/group strings in fattr into
 143  * their numeric uid/gid equivalents, and then frees the cached strings.
 144  */
 145 void nfs_fattr_map_and_free_names(struct nfs_server *server, struct nfs_fattr *fattr)
 146 {
 147         if (nfs_fattr_map_owner_name(server, fattr))
 148                 nfs_fattr_free_owner_name(fattr);
 149         if (nfs_fattr_map_group_name(server, fattr))
 150                 nfs_fattr_free_group_name(fattr);
 151 }
 152
 153 static int nfs_map_string_to_numeric(const char *name, size_t namelen, __u32 *res)
 154 {
 155         unsigned long val;
 156         char buf[16];
 157
 158         if (memchr(name, '@', namelen) != NULL || namelen >= sizeof(buf))
 159                 return 0;
 160         memcpy(buf, name, namelen);
 161         buf[namelen] = '\0';
 162         if (kstrtoul(buf, 0, &val) != 0)
 163                 return 0;
 164         *res = val;
 165         return 1;
 166 }
 167
 168 static int nfs_map_numeric_to_string(__u32 id, char *buf, size_t buflen)
 169 {
 170         return snprintf(buf, buflen, "%u", id);
 171 }
 172
 173 static struct key_type key_type_id_resolver = {
 174         .name           = "id_resolver",
 175         .instantiate    = user_instantiate,
 176         .match          = user_match,
 177         .revoke         = user_revoke,
 178         .destroy        = user_destroy,
 179         .describe       = user_describe,
 180         .read           = user_read,
 181 };
 182
 183 static int nfs_idmap_init_keyring(void)
 184 {
 185         struct cred *cred;
 186         struct key *keyring;
 187         int ret = 0;
 188
 189         printk(KERN_NOTICE "NFS: Registering the %s key type\n",
 190                 key_type_id_resolver.name);
 191
 192         cred = prepare_kernel_cred(NULL);
 193         if (!cred)
 194                 return -ENOMEM;
 195
 196         keyring = key_alloc(&key_type_keyring, ".id_resolver", 0, 0, cred,
 197                              (KEY_POS_ALL & ~KEY_POS_SETATTR) |
 198                              KEY_USR_VIEW | KEY_USR_READ,
 199                              KEY_ALLOC_NOT_IN_QUOTA);
 200         if (IS_ERR(keyring)) {
 201                 ret = PTR_ERR(keyring);
 202                 goto failed_put_cred;
 203         }
 204
 205         ret = key_instantiate_and_link(keyring, NULL, 0, NULL, NULL);
 206         if (ret < 0)
 207                 goto failed_put_key;
 208
 209         ret = register_key_type(&key_type_id_resolver);
 210         if (ret < 0)
 211                 goto failed_put_key;
 212
 213         ret = register_key_type(&key_type_id_resolver_legacy);
 214         if (ret < 0)
 215                 goto failed_reg_legacy;
 216
 217         set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
 218         cred->thread_keyring = keyring;
 219         cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
 220         id_resolver_cache = cred;
 221         return 0;
 222
 223 failed_reg_legacy:
 224         unregister_key_type(&key_type_id_resolver);
 225 failed_put_key:
 226         key_put(keyring);
 227 failed_put_cred:
 228         put_cred(cred);
 229         return ret;
 230 }
 231
 232 static void nfs_idmap_quit_keyring(void)
 233 {
 234         key_revoke(id_resolver_cache->thread_keyring);
 235         unregister_key_type(&key_type_id_resolver);
 236         unregister_key_type(&key_type_id_resolver_legacy);
 237         put_cred(id_resolver_cache);
 238 }
 239
 240 /*
 241  * Assemble the description to pass to request_key()
 242  * This function will allocate a new string and update dest to point
 243  * at it.  The caller is responsible for freeing dest.
 244  *
 245  * On error 0 is returned.  Otherwise, the length of dest is returned.
 246  */
 247 static ssize_t nfs_idmap_get_desc(const char *name, size_t namelen,
 248                                 const char *type, size_t typelen, char **desc)
 249 {
 250         char *cp;
 251         size_t desclen = typelen + namelen + 2;
 252
 253         *desc = kmalloc(desclen, GFP_KERNEL);
 254         if (!*desc)
 255                 return -ENOMEM;
 256
 257         cp = *desc;
 258         memcpy(cp, type, typelen);
 259         cp += typelen;
 260         *cp++ = ':';
 261
 262         memcpy(cp, name, namelen);
 263         cp += namelen;
 264         *cp = '\0';
 265         return desclen;
 266 }
 267
 268 static ssize_t nfs_idmap_request_key(struct key_type *key_type,
 269                                      const char *name, size_t namelen,
 270                                      const char *type, void *data,
 271                                      size_t data_size, struct idmap *idmap)
 272 {
 273         const struct cred *saved_cred;
 274         struct key *rkey;
 275         char *desc;
 276         struct user_key_payload *payload;
 277         ssize_t ret;
 278
 279         ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
 280         if (ret <= 0)
 281                 goto out;
 282
 283         saved_cred = override_creds(id_resolver_cache);
 284         if (idmap)
 285                 rkey = request_key_with_auxdata(key_type, desc, "", 0, idmap);
 286         else
 287                 rkey = request_key(&key_type_id_resolver, desc, "");
 288         revert_creds(saved_cred);
 289
 290         kfree(desc);
 291         if (IS_ERR(rkey)) {
 292                 ret = PTR_ERR(rkey);
 293                 goto out;
 294         }
 295
 296         rcu_read_lock();
 297         rkey->perm |= KEY_USR_VIEW;
 298
 299         ret = key_validate(rkey);
 300         if (ret < 0)
 301                 goto out_up;
 302
 303         payload = rcu_dereference(rkey->payload.data);
 304         if (IS_ERR_OR_NULL(payload)) {
 305                 ret = PTR_ERR(payload);
 306                 goto out_up;
 307         }
 308
 309         ret = payload->datalen;
 310         if (ret > 0 && ret <= data_size)
 311                 memcpy(data, payload->data, ret);
 312         else
 313                 ret = -EINVAL;
 314
 315 out_up:
 316         rcu_read_unlock();
 317         key_put(rkey);
 318 out:
 319         return ret;
 320 }
 321
 322 static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
 323                                  const char *type, void *data,
 324                                  size_t data_size, struct idmap *idmap)
 325 {
 326         ssize_t ret = nfs_idmap_request_key(&key_type_id_resolver,
 327                                             name, namelen, type, data,
 328                                             data_size, NULL);
 329         if (ret < 0) {
 330                 mutex_lock(&idmap->idmap_mutex);
 331                 ret = nfs_idmap_request_key(&key_type_id_resolver_legacy,
 332                                             name, namelen, type, data,
 333                                             data_size, idmap);
 334                 mutex_unlock(&idmap->idmap_mutex);
 335         }
 336         return ret;
 337 }
 338
 339 /* ID -> Name */
 340 static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf,
 341                                      size_t buflen, struct idmap *idmap)
 342 {
 343         char id_str[NFS_UINT_MAXLEN];
 344         int id_len;
 345         ssize_t ret;
 346
 347         id_len = snprintf(id_str, sizeof(id_str), "%u", id);
 348         ret = nfs_idmap_get_key(id_str, id_len, type, buf, buflen, idmap);
 349         if (ret < 0)
 350                 return -EINVAL;
 351         return ret;
 352 }
 353
 354 /* Name -> ID */
 355 static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *type,
 356                                __u32 *id, struct idmap *idmap)
 357 {
 358         char id_str[NFS_UINT_MAXLEN];
 359         long id_long;
 360         ssize_t data_size;
 361         int ret = 0;
 362
 363         data_size = nfs_idmap_get_key(name, namelen, type, id_str, NFS_UINT_MAXLEN, idmap);
 364         if (data_size <= 0) {
 365                 ret = -EINVAL;
 366         } else {
 367                 ret = kstrtol(id_str, 10, &id_long);
 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         .instantiate    = user_instantiate,
 403         .match          = user_match,
 404         .revoke         = user_revoke,
 405         .destroy        = user_destroy,
 406         .describe       = user_describe,
 407         .read           = user_read,
 408         .request_key    = nfs_idmap_legacy_upcall,
 409 };
 410
 411 static void __nfs_idmap_unregister(struct rpc_pipe *pipe)
 412 {
 413         if (pipe->dentry)
 414                 rpc_unlink(pipe->dentry);
 415 }
 416
 417 static int __nfs_idmap_register(struct dentry *dir,
 418                                      struct idmap *idmap,
 419                                      struct rpc_pipe *pipe)
 420 {
 421         struct dentry *dentry;
 422
 423         dentry = rpc_mkpipe_dentry(dir, "idmap", idmap, pipe);
 424         if (IS_ERR(dentry))
 425                 return PTR_ERR(dentry);
 426         pipe->dentry = dentry;
 427         return 0;
 428 }
 429
 430 static void nfs_idmap_unregister(struct nfs_client *clp,
 431                                       struct rpc_pipe *pipe)
 432 {
 433         struct net *net = clp->cl_net;
 434         struct super_block *pipefs_sb;
 435
 436         pipefs_sb = rpc_get_sb_net(net);
 437         if (pipefs_sb) {
 438                 __nfs_idmap_unregister(pipe);
 439                 rpc_put_sb_net(net);
 440         }
 441 }
 442
 443 static int nfs_idmap_register(struct nfs_client *clp,
 444                                    struct idmap *idmap,
 445                                    struct rpc_pipe *pipe)
 446 {
 447         struct net *net = clp->cl_net;
 448         struct super_block *pipefs_sb;
 449         int err = 0;
 450
 451         pipefs_sb = rpc_get_sb_net(net);
 452         if (pipefs_sb) {
 453                 if (clp->cl_rpcclient->cl_dentry)
 454                         err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
 455                                                    idmap, pipe);
 456                 rpc_put_sb_net(net);
 457         }
 458         return err;
 459 }
 460
 461 int
 462 nfs_idmap_new(struct nfs_client *clp)
 463 {
 464         struct idmap *idmap;
 465         struct rpc_pipe *pipe;
 466         int error;
 467
 468         idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
 469         if (idmap == NULL)
 470                 return -ENOMEM;
 471
 472         pipe = rpc_mkpipe_data(&idmap_upcall_ops, 0);
 473         if (IS_ERR(pipe)) {
 474                 error = PTR_ERR(pipe);
 475                 kfree(idmap);
 476                 return error;
 477         }
 478         error = nfs_idmap_register(clp, idmap, pipe);
 479         if (error) {
 480                 rpc_destroy_pipe_data(pipe);
 481                 kfree(idmap);
 482                 return error;
 483         }
 484         idmap->idmap_pipe = pipe;
 485         mutex_init(&idmap->idmap_mutex);
 486
 487         clp->cl_idmap = idmap;
 488         return 0;
 489 }
 490
 491 void
 492 nfs_idmap_delete(struct nfs_client *clp)
 493 {
 494         struct idmap *idmap = clp->cl_idmap;
 495
 496         if (!idmap)
 497                 return;
 498         nfs_idmap_unregister(clp, idmap->idmap_pipe);
 499         rpc_destroy_pipe_data(idmap->idmap_pipe);
 500         clp->cl_idmap = NULL;
 501         kfree(idmap);
 502 }
 503
 504 static int __rpc_pipefs_event(struct nfs_client *clp, unsigned long event,
 505                               struct super_block *sb)
 506 {
 507         int err = 0;
 508
 509         switch (event) {
 510         case RPC_PIPEFS_MOUNT:
 511                 err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
 512                                                 clp->cl_idmap,
 513                                                 clp->cl_idmap->idmap_pipe);
 514                 break;
 515         case RPC_PIPEFS_UMOUNT:
 516                 if (clp->cl_idmap->idmap_pipe) {
 517                         struct dentry *parent;
 518
 519                         parent = clp->cl_idmap->idmap_pipe->dentry->d_parent;
 520                         __nfs_idmap_unregister(clp->cl_idmap->idmap_pipe);
 521                         /*
 522                          * Note: This is a dirty hack. SUNRPC hook has been
 523                          * called already but simple_rmdir() call for the
 524                          * directory returned with error because of idmap pipe
 525                          * inside. Thus now we have to remove this directory
 526                          * here.
 527                          */
 528                         if (rpc_rmdir(parent))
 529                                 printk(KERN_ERR "NFS: %s: failed to remove "
 530                                         "clnt dir!\n", __func__);
 531                 }
 532                 break;
 533         default:
 534                 printk(KERN_ERR "NFS: %s: unknown event: %ld\n", __func__,
 535                         event);
 536                 return -ENOTSUPP;
 537         }
 538         return err;
 539 }
 540
 541 static struct nfs_client *nfs_get_client_for_event(struct net *net, int event)
 542 {
 543         struct nfs_net *nn = net_generic(net, nfs_net_id);
 544         struct dentry *cl_dentry;
 545         struct nfs_client *clp;
 546         int err;
 547
 548 restart:
 549         spin_lock(&nn->nfs_client_lock);
 550         list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
 551                 /* Wait for initialisation to finish */
 552                 if (clp->cl_cons_state == NFS_CS_INITING) {
 553                         atomic_inc(&clp->cl_count);
 554                         spin_unlock(&nn->nfs_client_lock);
 555                         err = nfs_wait_client_init_complete(clp);
 556                         nfs_put_client(clp);
 557                         if (err)
 558                                 return NULL;
 559                         goto restart;
 560                 }
 561                 /* Skip nfs_clients that failed to initialise */
 562                 if (clp->cl_cons_state < 0)
 563                         continue;
 564                 smp_rmb();
 565                 if (clp->rpc_ops != &nfs_v4_clientops)
 566                         continue;
 567                 cl_dentry = clp->cl_idmap->idmap_pipe->dentry;
 568                 if (((event == RPC_PIPEFS_MOUNT) && cl_dentry) ||
 569                     ((event == RPC_PIPEFS_UMOUNT) && !cl_dentry))
 570                         continue;
 571                 atomic_inc(&clp->cl_count);
 572                 spin_unlock(&nn->nfs_client_lock);
 573                 return clp;
 574         }
 575         spin_unlock(&nn->nfs_client_lock);
 576         return NULL;
 577 }
 578
 579 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 580                             void *ptr)
 581 {
 582         struct super_block *sb = ptr;
 583         struct nfs_client *clp;
 584         int error = 0;
 585
 586         if (!try_module_get(THIS_MODULE))
 587                 return 0;
 588
 589         while ((clp = nfs_get_client_for_event(sb->s_fs_info, event))) {
 590                 error = __rpc_pipefs_event(clp, event, sb);
 591                 nfs_put_client(clp);
 592                 if (error)
 593                         break;
 594         }
 595         module_put(THIS_MODULE);
 596         return error;
 597 }
 598
 599 #define PIPEFS_NFS_PRIO         1
 600
 601 static struct notifier_block nfs_idmap_block = {
 602         .notifier_call  = rpc_pipefs_event,
 603         .priority       = SUNRPC_PIPEFS_NFS_PRIO,
 604 };
 605
 606 int nfs_idmap_init(void)
 607 {
 608         int ret;
 609         ret = nfs_idmap_init_keyring();
 610         if (ret != 0)
 611                 goto out;
 612         ret = rpc_pipefs_notifier_register(&nfs_idmap_block);
 613         if (ret != 0)
 614                 nfs_idmap_quit_keyring();
 615 out:
 616         return ret;
 617 }
 618
 619 void nfs_idmap_quit(void)
 620 {
 621         rpc_pipefs_notifier_unregister(&nfs_idmap_block);
 622         nfs_idmap_quit_keyring();
 623 }
 624
 625 static int nfs_idmap_prepare_message(char *desc, struct idmap *idmap,
 626                                      struct idmap_msg *im,
 627                                      struct rpc_pipe_msg *msg)
 628 {
 629         substring_t substr;
 630         int token, ret;
 631
 632         im->im_type = IDMAP_TYPE_GROUP;
 633         token = match_token(desc, nfs_idmap_tokens, &substr);
 634
 635         switch (token) {
 636         case Opt_find_uid:
 637                 im->im_type = IDMAP_TYPE_USER;
 638         case Opt_find_gid:
 639                 im->im_conv = IDMAP_CONV_NAMETOID;
 640                 ret = match_strlcpy(im->im_name, &substr, IDMAP_NAMESZ);
 641                 break;
 642
 643         case Opt_find_user:
 644                 im->im_type = IDMAP_TYPE_USER;
 645         case Opt_find_group:
 646                 im->im_conv = IDMAP_CONV_IDTONAME;
 647                 ret = match_int(&substr, &im->im_id);
 648                 break;
 649
 650         default:
 651                 ret = -EINVAL;
 652                 goto out;
 653         }
 654
 655         msg->data = im;
 656         msg->len  = sizeof(struct idmap_msg);
 657
 658 out:
 659         return ret;
 660 }
 661
 662 static bool
 663 nfs_idmap_prepare_pipe_upcall(struct idmap *idmap,
 664                 struct idmap_legacy_upcalldata *data)
 665 {
 666         if (idmap->idmap_upcall_data != NULL) {
 667                 WARN_ON_ONCE(1);
 668                 return false;
 669         }
 670         idmap->idmap_upcall_data = data;
 671         return true;
 672 }
 673
 674 static void
 675 nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, int ret)
 676 {
 677         struct key_construction *cons = idmap->idmap_upcall_data->key_cons;
 678
 679         kfree(idmap->idmap_upcall_data);
 680         idmap->idmap_upcall_data = NULL;
 681         complete_request_key(cons, ret);
 682 }
 683
 684 static void
 685 nfs_idmap_abort_pipe_upcall(struct idmap *idmap, int ret)
 686 {
 687         if (idmap->idmap_upcall_data != NULL)
 688                 nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
 689 }
 690
 691 static int nfs_idmap_legacy_upcall(struct key_construction *cons,
 692                                    const char *op,
 693                                    void *aux)
 694 {
 695         struct idmap_legacy_upcalldata *data;
 696         struct rpc_pipe_msg *msg;
 697         struct idmap_msg *im;
 698         struct idmap *idmap = (struct idmap *)aux;
 699         struct key *key = cons->key;
 700         int ret = -ENOMEM;
 701
 702         /* msg and im are freed in idmap_pipe_destroy_msg */
 703         data = kzalloc(sizeof(*data), GFP_KERNEL);
 704         if (!data)
 705                 goto out1;
 706
 707         msg = &data->pipe_msg;
 708         im = &data->idmap_msg;
 709         data->idmap = idmap;
 710         data->key_cons = cons;
 711
 712         ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);
 713         if (ret < 0)
 714                 goto out2;
 715
 716         ret = -EAGAIN;
 717         if (!nfs_idmap_prepare_pipe_upcall(idmap, data))
 718                 goto out2;
 719
 720         ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
 721         if (ret < 0)
 722                 nfs_idmap_abort_pipe_upcall(idmap, ret);
 723
 724         return ret;
 725 out2:
 726         kfree(data);
 727 out1:
 728         complete_request_key(cons, ret);
 729         return ret;
 730 }
 731
 732 static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *data)
 733 {
 734         return key_instantiate_and_link(key, data, strlen(data) + 1,
 735                                         id_resolver_cache->thread_keyring,
 736                                         authkey);
 737 }
 738
 739 static int nfs_idmap_read_and_verify_message(struct idmap_msg *im,
 740                 struct idmap_msg *upcall,
 741                 struct key *key, struct key *authkey)
 742 {
 743         char id_str[NFS_UINT_MAXLEN];
 744         int ret = -ENOKEY;
 745
 746         /* ret = -ENOKEY */
 747         if (upcall->im_type != im->im_type || upcall->im_conv != im->im_conv)
 748                 goto out;
 749         switch (im->im_conv) {
 750         case IDMAP_CONV_NAMETOID:
 751                 if (strcmp(upcall->im_name, im->im_name) != 0)
 752                         break;
 753                 sprintf(id_str, "%d", im->im_id);
 754                 ret = nfs_idmap_instantiate(key, authkey, id_str);
 755                 break;
 756         case IDMAP_CONV_IDTONAME:
 757                 if (upcall->im_id != im->im_id)
 758                         break;
 759                 ret = nfs_idmap_instantiate(key, authkey, im->im_name);
 760                 break;
 761         default:
 762                 ret = -EINVAL;
 763         }
 764 out:
 765         return ret;
 766 }
 767
 768 static ssize_t
 769 idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 770 {
 771         struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
 772         struct idmap *idmap = (struct idmap *)rpci->private;
 773         struct key_construction *cons;
 774         struct idmap_msg im;
 775         size_t namelen_in;
 776         int ret = -ENOKEY;
 777
 778         /* If instantiation is successful, anyone waiting for key construction
 779          * will have been woken up and someone else may now have used
 780          * idmap_key_cons - so after this point we may no longer touch it.
 781          */
 782         if (idmap->idmap_upcall_data == NULL)
 783                 goto out_noupcall;
 784
 785         cons = idmap->idmap_upcall_data->key_cons;
 786
 787         if (mlen != sizeof(im)) {
 788                 ret = -ENOSPC;
 789                 goto out;
 790         }
 791
 792         if (copy_from_user(&im, src, mlen) != 0) {
 793                 ret = -EFAULT;
 794                 goto out;
 795         }
 796
 797         if (!(im.im_status & IDMAP_STATUS_SUCCESS)) {
 798                 ret = -ENOKEY;
 799                 goto out;
 800         }
 801
 802         namelen_in = strnlen(im.im_name, IDMAP_NAMESZ);
 803         if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
 804                 ret = -EINVAL;
 805                 goto out;
 806 }
 807
 808         ret = nfs_idmap_read_and_verify_message(&im,
 809                         &idmap->idmap_upcall_data->idmap_msg,
 810                         cons->key, cons->authkey);
 811         if (ret >= 0) {
 812                 key_set_timeout(cons->key, nfs_idmap_cache_timeout);
 813                 ret = mlen;
 814         }
 815
 816 out:
 817         nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
 818 out_noupcall:
 819         return ret;
 820 }
 821
 822 static void
 823 idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 824 {
 825         struct idmap_legacy_upcalldata *data = container_of(msg,
 826                         struct idmap_legacy_upcalldata,
 827                         pipe_msg);
 828         struct idmap *idmap = data->idmap;
 829
 830         if (msg->errno)
 831                 nfs_idmap_abort_pipe_upcall(idmap, msg->errno);
 832 }
 833
 834 static void
 835 idmap_release_pipe(struct inode *inode)
 836 {
 837         struct rpc_inode *rpci = RPC_I(inode);
 838         struct idmap *idmap = (struct idmap *)rpci->private;
 839
 840         nfs_idmap_abort_pipe_upcall(idmap, -EPIPE);
 841 }
 842
 843 int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid)
 844 {
 845         struct idmap *idmap = server->nfs_client->cl_idmap;
 846
 847         if (nfs_map_string_to_numeric(name, namelen, uid))
 848                 return 0;
 849         return nfs_idmap_lookup_id(name, namelen, "uid", uid, idmap);
 850 }
 851
 852 int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *gid)
 853 {
 854         struct idmap *idmap = server->nfs_client->cl_idmap;
 855
 856         if (nfs_map_string_to_numeric(name, namelen, gid))
 857                 return 0;
 858         return nfs_idmap_lookup_id(name, namelen, "gid", gid, idmap);
 859 }
 860
 861 int nfs_map_uid_to_name(const struct nfs_server *server, __u32 uid, char *buf, size_t buflen)
 862 {
 863         struct idmap *idmap = server->nfs_client->cl_idmap;
 864         int ret = -EINVAL;
 865
 866         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 867                 ret = nfs_idmap_lookup_name(uid, "user", buf, buflen, idmap);
 868         if (ret < 0)
 869                 ret = nfs_map_numeric_to_string(uid, buf, buflen);
 870         return ret;
 871 }
 872 int nfs_map_gid_to_group(const struct nfs_server *server, __u32 gid, char *buf, size_t buflen)
 873 {
 874         struct idmap *idmap = server->nfs_client->cl_idmap;
 875         int ret = -EINVAL;
 876
 877         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 878                 ret = nfs_idmap_lookup_name(gid, "group", buf, buflen, idmap);
 879         if (ret < 0)
 880                 ret = nfs_map_numeric_to_string(gid, buf, buflen);
 881         return ret;
 882 }