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 = keyring_alloc(".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, NULL);
 200         if (IS_ERR(keyring)) {
 201                 ret = PTR_ERR(keyring);
 202                 goto failed_put_cred;
 203         }
 204
 205         ret = register_key_type(&key_type_id_resolver);
 206         if (ret < 0)
 207                 goto failed_put_key;
 208
 209         ret = register_key_type(&key_type_id_resolver_legacy);
 210         if (ret < 0)
 211                 goto failed_reg_legacy;
 212
 213         set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
 214         cred->thread_keyring = keyring;
 215         cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
 216         id_resolver_cache = cred;
 217         return 0;
 218
 219 failed_reg_legacy:
 220         unregister_key_type(&key_type_id_resolver);
 221 failed_put_key:
 222         key_put(keyring);
 223 failed_put_cred:
 224         put_cred(cred);
 225         return ret;
 226 }
 227
 228 static void nfs_idmap_quit_keyring(void)
 229 {
 230         key_revoke(id_resolver_cache->thread_keyring);
 231         unregister_key_type(&key_type_id_resolver);
 232         unregister_key_type(&key_type_id_resolver_legacy);
 233         put_cred(id_resolver_cache);
 234 }
 235
 236 /*
 237  * Assemble the description to pass to request_key()
 238  * This function will allocate a new string and update dest to point
 239  * at it.  The caller is responsible for freeing dest.
 240  *
 241  * On error 0 is returned.  Otherwise, the length of dest is returned.
 242  */
 243 static ssize_t nfs_idmap_get_desc(const char *name, size_t namelen,
 244                                 const char *type, size_t typelen, char **desc)
 245 {
 246         char *cp;
 247         size_t desclen = typelen + namelen + 2;
 248
 249         *desc = kmalloc(desclen, GFP_KERNEL);
 250         if (!*desc)
 251                 return -ENOMEM;
 252
 253         cp = *desc;
 254         memcpy(cp, type, typelen);
 255         cp += typelen;
 256         *cp++ = ':';
 257
 258         memcpy(cp, name, namelen);
 259         cp += namelen;
 260         *cp = '\0';
 261         return desclen;
 262 }
 263
 264 static ssize_t nfs_idmap_request_key(struct key_type *key_type,
 265                                      const char *name, size_t namelen,
 266                                      const char *type, void *data,
 267                                      size_t data_size, struct idmap *idmap)
 268 {
 269         const struct cred *saved_cred;
 270         struct key *rkey;
 271         char *desc;
 272         struct user_key_payload *payload;
 273         ssize_t ret;
 274
 275         ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
 276         if (ret <= 0)
 277                 goto out;
 278
 279         saved_cred = override_creds(id_resolver_cache);
 280         if (idmap)
 281                 rkey = request_key_with_auxdata(key_type, desc, "", 0, idmap);
 282         else
 283                 rkey = request_key(&key_type_id_resolver, desc, "");
 284         revert_creds(saved_cred);
 285
 286         kfree(desc);
 287         if (IS_ERR(rkey)) {
 288                 ret = PTR_ERR(rkey);
 289                 goto out;
 290         }
 291
 292         rcu_read_lock();
 293         rkey->perm |= KEY_USR_VIEW;
 294
 295         ret = key_validate(rkey);
 296         if (ret < 0)
 297                 goto out_up;
 298
 299         payload = rcu_dereference(rkey->payload.data);
 300         if (IS_ERR_OR_NULL(payload)) {
 301                 ret = PTR_ERR(payload);
 302                 goto out_up;
 303         }
 304
 305         ret = payload->datalen;
 306         if (ret > 0 && ret <= data_size)
 307                 memcpy(data, payload->data, ret);
 308         else
 309                 ret = -EINVAL;
 310
 311 out_up:
 312         rcu_read_unlock();
 313         key_put(rkey);
 314 out:
 315         return ret;
 316 }
 317
 318 static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
 319                                  const char *type, void *data,
 320                                  size_t data_size, struct idmap *idmap)
 321 {
 322         ssize_t ret = nfs_idmap_request_key(&key_type_id_resolver,
 323                                             name, namelen, type, data,
 324                                             data_size, NULL);
 325         if (ret < 0) {
 326                 mutex_lock(&idmap->idmap_mutex);
 327                 ret = nfs_idmap_request_key(&key_type_id_resolver_legacy,
 328                                             name, namelen, type, data,
 329                                             data_size, idmap);
 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 = kstrtol(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         idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
 465         if (idmap == NULL)
 466                 return -ENOMEM;
 467
 468         pipe = rpc_mkpipe_data(&idmap_upcall_ops, 0);
 469         if (IS_ERR(pipe)) {
 470                 error = PTR_ERR(pipe);
 471                 kfree(idmap);
 472                 return error;
 473         }
 474         error = nfs_idmap_register(clp, idmap, pipe);
 475         if (error) {
 476                 rpc_destroy_pipe_data(pipe);
 477                 kfree(idmap);
 478                 return error;
 479         }
 480         idmap->idmap_pipe = pipe;
 481         mutex_init(&idmap->idmap_mutex);
 482
 483         clp->cl_idmap = idmap;
 484         return 0;
 485 }
 486
 487 void
 488 nfs_idmap_delete(struct nfs_client *clp)
 489 {
 490         struct idmap *idmap = clp->cl_idmap;
 491
 492         if (!idmap)
 493                 return;
 494         nfs_idmap_unregister(clp, idmap->idmap_pipe);
 495         rpc_destroy_pipe_data(idmap->idmap_pipe);
 496         clp->cl_idmap = NULL;
 497         kfree(idmap);
 498 }
 499
 500 static int __rpc_pipefs_event(struct nfs_client *clp, unsigned long event,
 501                               struct super_block *sb)
 502 {
 503         int err = 0;
 504
 505         switch (event) {
 506         case RPC_PIPEFS_MOUNT:
 507                 err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
 508                                                 clp->cl_idmap,
 509                                                 clp->cl_idmap->idmap_pipe);
 510                 break;
 511         case RPC_PIPEFS_UMOUNT:
 512                 if (clp->cl_idmap->idmap_pipe) {
 513                         struct dentry *parent;
 514
 515                         parent = clp->cl_idmap->idmap_pipe->dentry->d_parent;
 516                         __nfs_idmap_unregister(clp->cl_idmap->idmap_pipe);
 517                         /*
 518                          * Note: This is a dirty hack. SUNRPC hook has been
 519                          * called already but simple_rmdir() call for the
 520                          * directory returned with error because of idmap pipe
 521                          * inside. Thus now we have to remove this directory
 522                          * here.
 523                          */
 524                         if (rpc_rmdir(parent))
 525                                 printk(KERN_ERR "NFS: %s: failed to remove "
 526                                         "clnt dir!\n", __func__);
 527                 }
 528                 break;
 529         default:
 530                 printk(KERN_ERR "NFS: %s: unknown event: %ld\n", __func__,
 531                         event);
 532                 return -ENOTSUPP;
 533         }
 534         return err;
 535 }
 536
 537 static struct nfs_client *nfs_get_client_for_event(struct net *net, int event)
 538 {
 539         struct nfs_net *nn = net_generic(net, nfs_net_id);
 540         struct dentry *cl_dentry;
 541         struct nfs_client *clp;
 542         int err;
 543
 544 restart:
 545         spin_lock(&nn->nfs_client_lock);
 546         list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
 547                 /* Wait for initialisation to finish */
 548                 if (clp->cl_cons_state == NFS_CS_INITING) {
 549                         atomic_inc(&clp->cl_count);
 550                         spin_unlock(&nn->nfs_client_lock);
 551                         err = nfs_wait_client_init_complete(clp);
 552                         nfs_put_client(clp);
 553                         if (err)
 554                                 return NULL;
 555                         goto restart;
 556                 }
 557                 /* Skip nfs_clients that failed to initialise */
 558                 if (clp->cl_cons_state < 0)
 559                         continue;
 560                 smp_rmb();
 561                 if (clp->rpc_ops != &nfs_v4_clientops)
 562                         continue;
 563                 cl_dentry = clp->cl_idmap->idmap_pipe->dentry;
 564                 if (((event == RPC_PIPEFS_MOUNT) && cl_dentry) ||
 565                     ((event == RPC_PIPEFS_UMOUNT) && !cl_dentry))
 566                         continue;
 567                 atomic_inc(&clp->cl_count);
 568                 spin_unlock(&nn->nfs_client_lock);
 569                 return clp;
 570         }
 571         spin_unlock(&nn->nfs_client_lock);
 572         return NULL;
 573 }
 574
 575 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 576                             void *ptr)
 577 {
 578         struct super_block *sb = ptr;
 579         struct nfs_client *clp;
 580         int error = 0;
 581
 582         if (!try_module_get(THIS_MODULE))
 583                 return 0;
 584
 585         while ((clp = nfs_get_client_for_event(sb->s_fs_info, event))) {
 586                 error = __rpc_pipefs_event(clp, event, sb);
 587                 nfs_put_client(clp);
 588                 if (error)
 589                         break;
 590         }
 591         module_put(THIS_MODULE);
 592         return error;
 593 }
 594
 595 #define PIPEFS_NFS_PRIO         1
 596
 597 static struct notifier_block nfs_idmap_block = {
 598         .notifier_call  = rpc_pipefs_event,
 599         .priority       = SUNRPC_PIPEFS_NFS_PRIO,
 600 };
 601
 602 int nfs_idmap_init(void)
 603 {
 604         int ret;
 605         ret = nfs_idmap_init_keyring();
 606         if (ret != 0)
 607                 goto out;
 608         ret = rpc_pipefs_notifier_register(&nfs_idmap_block);
 609         if (ret != 0)
 610                 nfs_idmap_quit_keyring();
 611 out:
 612         return ret;
 613 }
 614
 615 void nfs_idmap_quit(void)
 616 {
 617         rpc_pipefs_notifier_unregister(&nfs_idmap_block);
 618         nfs_idmap_quit_keyring();
 619 }
 620
 621 static int nfs_idmap_prepare_message(char *desc, struct idmap *idmap,
 622                                      struct idmap_msg *im,
 623                                      struct rpc_pipe_msg *msg)
 624 {
 625         substring_t substr;
 626         int token, ret;
 627
 628         im->im_type = IDMAP_TYPE_GROUP;
 629         token = match_token(desc, nfs_idmap_tokens, &substr);
 630
 631         switch (token) {
 632         case Opt_find_uid:
 633                 im->im_type = IDMAP_TYPE_USER;
 634         case Opt_find_gid:
 635                 im->im_conv = IDMAP_CONV_NAMETOID;
 636                 ret = match_strlcpy(im->im_name, &substr, IDMAP_NAMESZ);
 637                 break;
 638
 639         case Opt_find_user:
 640                 im->im_type = IDMAP_TYPE_USER;
 641         case Opt_find_group:
 642                 im->im_conv = IDMAP_CONV_IDTONAME;
 643                 ret = match_int(&substr, &im->im_id);
 644                 break;
 645
 646         default:
 647                 ret = -EINVAL;
 648                 goto out;
 649         }
 650
 651         msg->data = im;
 652         msg->len  = sizeof(struct idmap_msg);
 653
 654 out:
 655         return ret;
 656 }
 657
 658 static bool
 659 nfs_idmap_prepare_pipe_upcall(struct idmap *idmap,
 660                 struct idmap_legacy_upcalldata *data)
 661 {
 662         if (idmap->idmap_upcall_data != NULL) {
 663                 WARN_ON_ONCE(1);
 664                 return false;
 665         }
 666         idmap->idmap_upcall_data = data;
 667         return true;
 668 }
 669
 670 static void
 671 nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, int ret)
 672 {
 673         struct key_construction *cons = idmap->idmap_upcall_data->key_cons;
 674
 675         kfree(idmap->idmap_upcall_data);
 676         idmap->idmap_upcall_data = NULL;
 677         complete_request_key(cons, ret);
 678 }
 679
 680 static void
 681 nfs_idmap_abort_pipe_upcall(struct idmap *idmap, int ret)
 682 {
 683         if (idmap->idmap_upcall_data != NULL)
 684                 nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
 685 }
 686
 687 static int nfs_idmap_legacy_upcall(struct key_construction *cons,
 688                                    const char *op,
 689                                    void *aux)
 690 {
 691         struct idmap_legacy_upcalldata *data;
 692         struct rpc_pipe_msg *msg;
 693         struct idmap_msg *im;
 694         struct idmap *idmap = (struct idmap *)aux;
 695         struct key *key = cons->key;
 696         int ret = -ENOMEM;
 697
 698         /* msg and im are freed in idmap_pipe_destroy_msg */
 699         data = kzalloc(sizeof(*data), GFP_KERNEL);
 700         if (!data)
 701                 goto out1;
 702
 703         msg = &data->pipe_msg;
 704         im = &data->idmap_msg;
 705         data->idmap = idmap;
 706         data->key_cons = cons;
 707
 708         ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);
 709         if (ret < 0)
 710                 goto out2;
 711
 712         ret = -EAGAIN;
 713         if (!nfs_idmap_prepare_pipe_upcall(idmap, data))
 714                 goto out2;
 715
 716         ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
 717         if (ret < 0)
 718                 nfs_idmap_abort_pipe_upcall(idmap, ret);
 719
 720         return ret;
 721 out2:
 722         kfree(data);
 723 out1:
 724         complete_request_key(cons, ret);
 725         return ret;
 726 }
 727
 728 static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *data)
 729 {
 730         return key_instantiate_and_link(key, data, strlen(data) + 1,
 731                                         id_resolver_cache->thread_keyring,
 732                                         authkey);
 733 }
 734
 735 static int nfs_idmap_read_and_verify_message(struct idmap_msg *im,
 736                 struct idmap_msg *upcall,
 737                 struct key *key, struct key *authkey)
 738 {
 739         char id_str[NFS_UINT_MAXLEN];
 740         int ret = -ENOKEY;
 741
 742         /* ret = -ENOKEY */
 743         if (upcall->im_type != im->im_type || upcall->im_conv != im->im_conv)
 744                 goto out;
 745         switch (im->im_conv) {
 746         case IDMAP_CONV_NAMETOID:
 747                 if (strcmp(upcall->im_name, im->im_name) != 0)
 748                         break;
 749                 sprintf(id_str, "%d", im->im_id);
 750                 ret = nfs_idmap_instantiate(key, authkey, id_str);
 751                 break;
 752         case IDMAP_CONV_IDTONAME:
 753                 if (upcall->im_id != im->im_id)
 754                         break;
 755                 ret = nfs_idmap_instantiate(key, authkey, im->im_name);
 756                 break;
 757         default:
 758                 ret = -EINVAL;
 759         }
 760 out:
 761         return ret;
 762 }
 763
 764 static ssize_t
 765 idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 766 {
 767         struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
 768         struct idmap *idmap = (struct idmap *)rpci->private;
 769         struct key_construction *cons;
 770         struct idmap_msg im;
 771         size_t namelen_in;
 772         int ret = -ENOKEY;
 773
 774         /* If instantiation is successful, anyone waiting for key construction
 775          * will have been woken up and someone else may now have used
 776          * idmap_key_cons - so after this point we may no longer touch it.
 777          */
 778         if (idmap->idmap_upcall_data == NULL)
 779                 goto out_noupcall;
 780
 781         cons = idmap->idmap_upcall_data->key_cons;
 782
 783         if (mlen != sizeof(im)) {
 784                 ret = -ENOSPC;
 785                 goto out;
 786         }
 787
 788         if (copy_from_user(&im, src, mlen) != 0) {
 789                 ret = -EFAULT;
 790                 goto out;
 791         }
 792
 793         if (!(im.im_status & IDMAP_STATUS_SUCCESS)) {
 794                 ret = -ENOKEY;
 795                 goto out;
 796         }
 797
 798         namelen_in = strnlen(im.im_name, IDMAP_NAMESZ);
 799         if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
 800                 ret = -EINVAL;
 801                 goto out;
 802 }
 803
 804         ret = nfs_idmap_read_and_verify_message(&im,
 805                         &idmap->idmap_upcall_data->idmap_msg,
 806                         cons->key, cons->authkey);
 807         if (ret >= 0) {
 808                 key_set_timeout(cons->key, nfs_idmap_cache_timeout);
 809                 ret = mlen;
 810         }
 811
 812 out:
 813         nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
 814 out_noupcall:
 815         return ret;
 816 }
 817
 818 static void
 819 idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 820 {
 821         struct idmap_legacy_upcalldata *data = container_of(msg,
 822                         struct idmap_legacy_upcalldata,
 823                         pipe_msg);
 824         struct idmap *idmap = data->idmap;
 825
 826         if (msg->errno)
 827                 nfs_idmap_abort_pipe_upcall(idmap, msg->errno);
 828 }
 829
 830 static void
 831 idmap_release_pipe(struct inode *inode)
 832 {
 833         struct rpc_inode *rpci = RPC_I(inode);
 834         struct idmap *idmap = (struct idmap *)rpci->private;
 835
 836         nfs_idmap_abort_pipe_upcall(idmap, -EPIPE);
 837 }
 838
 839 int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid)
 840 {
 841         struct idmap *idmap = server->nfs_client->cl_idmap;
 842
 843         if (nfs_map_string_to_numeric(name, namelen, uid))
 844                 return 0;
 845         return nfs_idmap_lookup_id(name, namelen, "uid", uid, idmap);
 846 }
 847
 848 int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *gid)
 849 {
 850         struct idmap *idmap = server->nfs_client->cl_idmap;
 851
 852         if (nfs_map_string_to_numeric(name, namelen, gid))
 853                 return 0;
 854         return nfs_idmap_lookup_id(name, namelen, "gid", gid, idmap);
 855 }
 856
 857 int nfs_map_uid_to_name(const struct nfs_server *server, __u32 uid, char *buf, size_t buflen)
 858 {
 859         struct idmap *idmap = server->nfs_client->cl_idmap;
 860         int ret = -EINVAL;
 861
 862         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 863                 ret = nfs_idmap_lookup_name(uid, "user", buf, buflen, idmap);
 864         if (ret < 0)
 865                 ret = nfs_map_numeric_to_string(uid, buf, buflen);
 866         return ret;
 867 }
 868 int nfs_map_gid_to_group(const struct nfs_server *server, __u32 gid, char *buf, size_t buflen)
 869 {
 870         struct idmap *idmap = server->nfs_client->cl_idmap;
 871         int ret = -EINVAL;
 872
 873         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 874                 ret = nfs_idmap_lookup_name(gid, "group", buf, buflen, idmap);
 875         if (ret < 0)
 876                 ret = nfs_map_numeric_to_string(gid, buf, buflen);
 877         return ret;
 878 }