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 #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         *idmap_pipe;
  68         struct idmap_legacy_upcalldata *idmap_upcall_data;
  69         struct mutex            idmap_mutex;
  70 };
  71
  72 /**
  73  * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
  74  * @fattr: fully initialised struct nfs_fattr
  75  * @owner_name: owner name string cache
  76  * @group_name: group name string cache
  77  */
  78 void nfs_fattr_init_names(struct nfs_fattr *fattr,
  79                 struct nfs4_string *owner_name,
  80                 struct nfs4_string *group_name)
  81 {
  82         fattr->owner_name = owner_name;
  83         fattr->group_name = group_name;
  84 }
  85
  86 static void nfs_fattr_free_owner_name(struct nfs_fattr *fattr)
  87 {
  88         fattr->valid &= ~NFS_ATTR_FATTR_OWNER_NAME;
  89         kfree(fattr->owner_name->data);
  90 }
  91
  92 static void nfs_fattr_free_group_name(struct nfs_fattr *fattr)
  93 {
  94         fattr->valid &= ~NFS_ATTR_FATTR_GROUP_NAME;
  95         kfree(fattr->group_name->data);
  96 }
  97
  98 static bool nfs_fattr_map_owner_name(struct nfs_server *server, struct nfs_fattr *fattr)
  99 {
 100         struct nfs4_string *owner = fattr->owner_name;
 101         kuid_t uid;
 102
 103         if (!(fattr->valid & NFS_ATTR_FATTR_OWNER_NAME))
 104                 return false;
 105         if (nfs_map_name_to_uid(server, owner->data, owner->len, &uid) == 0) {
 106                 fattr->uid = uid;
 107                 fattr->valid |= NFS_ATTR_FATTR_OWNER;
 108         }
 109         return true;
 110 }
 111
 112 static bool nfs_fattr_map_group_name(struct nfs_server *server, struct nfs_fattr *fattr)
 113 {
 114         struct nfs4_string *group = fattr->group_name;
 115         kgid_t gid;
 116
 117         if (!(fattr->valid & NFS_ATTR_FATTR_GROUP_NAME))
 118                 return false;
 119         if (nfs_map_group_to_gid(server, group->data, group->len, &gid) == 0) {
 120                 fattr->gid = gid;
 121                 fattr->valid |= NFS_ATTR_FATTR_GROUP;
 122         }
 123         return true;
 124 }
 125
 126 /**
 127  * nfs_fattr_free_names - free up the NFSv4 owner and group strings
 128  * @fattr: a fully initialised nfs_fattr structure
 129  */
 130 void nfs_fattr_free_names(struct nfs_fattr *fattr)
 131 {
 132         if (fattr->valid & NFS_ATTR_FATTR_OWNER_NAME)
 133                 nfs_fattr_free_owner_name(fattr);
 134         if (fattr->valid & NFS_ATTR_FATTR_GROUP_NAME)
 135                 nfs_fattr_free_group_name(fattr);
 136 }
 137
 138 /**
 139  * nfs_fattr_map_and_free_names - map owner/group strings into uid/gid and free
 140  * @server: pointer to the filesystem nfs_server structure
 141  * @fattr: a fully initialised nfs_fattr structure
 142  *
 143  * This helper maps the cached NFSv4 owner/group strings in fattr into
 144  * their numeric uid/gid equivalents, and then frees the cached strings.
 145  */
 146 void nfs_fattr_map_and_free_names(struct nfs_server *server, struct nfs_fattr *fattr)
 147 {
 148         if (nfs_fattr_map_owner_name(server, fattr))
 149                 nfs_fattr_free_owner_name(fattr);
 150         if (nfs_fattr_map_group_name(server, fattr))
 151                 nfs_fattr_free_group_name(fattr);
 152 }
 153
 154 static int nfs_map_string_to_numeric(const char *name, size_t namelen, __u32 *res)
 155 {
 156         unsigned long val;
 157         char buf[16];
 158
 159         if (memchr(name, '@', namelen) != NULL || namelen >= sizeof(buf))
 160                 return 0;
 161         memcpy(buf, name, namelen);
 162         buf[namelen] = '\0';
 163         if (kstrtoul(buf, 0, &val) != 0)
 164                 return 0;
 165         *res = val;
 166         return 1;
 167 }
 168
 169 static int nfs_map_numeric_to_string(__u32 id, char *buf, size_t buflen)
 170 {
 171         return snprintf(buf, buflen, "%u", id);
 172 }
 173
 174 static struct key_type key_type_id_resolver = {
 175         .name           = "id_resolver",
 176         .instantiate    = user_instantiate,
 177         .match          = user_match,
 178         .revoke         = user_revoke,
 179         .destroy        = user_destroy,
 180         .describe       = user_describe,
 181         .read           = user_read,
 182 };
 183
 184 static int nfs_idmap_init_keyring(void)
 185 {
 186         struct cred *cred;
 187         struct key *keyring;
 188         int ret = 0;
 189
 190         printk(KERN_NOTICE "NFS: Registering the %s key type\n",
 191                 key_type_id_resolver.name);
 192
 193         cred = prepare_kernel_cred(NULL);
 194         if (!cred)
 195                 return -ENOMEM;
 196
 197         keyring = keyring_alloc(".id_resolver",
 198                                 GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
 199                                 (KEY_POS_ALL & ~KEY_POS_SETATTR) |
 200                                 KEY_USR_VIEW | KEY_USR_READ,
 201                                 KEY_ALLOC_NOT_IN_QUOTA, NULL);
 202         if (IS_ERR(keyring)) {
 203                 ret = PTR_ERR(keyring);
 204                 goto failed_put_cred;
 205         }
 206
 207         ret = register_key_type(&key_type_id_resolver);
 208         if (ret < 0)
 209                 goto failed_put_key;
 210
 211         ret = register_key_type(&key_type_id_resolver_legacy);
 212         if (ret < 0)
 213                 goto failed_reg_legacy;
 214
 215         set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
 216         cred->thread_keyring = keyring;
 217         cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
 218         id_resolver_cache = cred;
 219         return 0;
 220
 221 failed_reg_legacy:
 222         unregister_key_type(&key_type_id_resolver);
 223 failed_put_key:
 224         key_put(keyring);
 225 failed_put_cred:
 226         put_cred(cred);
 227         return ret;
 228 }
 229
 230 static void nfs_idmap_quit_keyring(void)
 231 {
 232         key_revoke(id_resolver_cache->thread_keyring);
 233         unregister_key_type(&key_type_id_resolver);
 234         unregister_key_type(&key_type_id_resolver_legacy);
 235         put_cred(id_resolver_cache);
 236 }
 237
 238 /*
 239  * Assemble the description to pass to request_key()
 240  * This function will allocate a new string and update dest to point
 241  * at it.  The caller is responsible for freeing dest.
 242  *
 243  * On error 0 is returned.  Otherwise, the length of dest is returned.
 244  */
 245 static ssize_t nfs_idmap_get_desc(const char *name, size_t namelen,
 246                                 const char *type, size_t typelen, char **desc)
 247 {
 248         char *cp;
 249         size_t desclen = typelen + namelen + 2;
 250
 251         *desc = kmalloc(desclen, GFP_KERNEL);
 252         if (!*desc)
 253                 return -ENOMEM;
 254
 255         cp = *desc;
 256         memcpy(cp, type, typelen);
 257         cp += typelen;
 258         *cp++ = ':';
 259
 260         memcpy(cp, name, namelen);
 261         cp += namelen;
 262         *cp = '\0';
 263         return desclen;
 264 }
 265
 266 static struct key *nfs_idmap_request_key(const char *name, size_t namelen,
 267                                          const char *type, struct idmap *idmap)
 268 {
 269         char *desc;
 270         struct key *rkey;
 271         ssize_t ret;
 272
 273         ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
 274         if (ret <= 0)
 275                 return ERR_PTR(ret);
 276
 277         rkey = request_key(&key_type_id_resolver, desc, "");
 278         if (IS_ERR(rkey)) {
 279                 mutex_lock(&idmap->idmap_mutex);
 280                 rkey = request_key_with_auxdata(&key_type_id_resolver_legacy,
 281                                                 desc, "", 0, idmap);
 282                 mutex_unlock(&idmap->idmap_mutex);
 283         }
 284
 285         kfree(desc);
 286         return rkey;
 287 }
 288
 289 static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
 290                                  const char *type, void *data,
 291                                  size_t data_size, struct idmap *idmap)
 292 {
 293         const struct cred *saved_cred;
 294         struct key *rkey;
 295         struct user_key_payload *payload;
 296         ssize_t ret;
 297
 298         saved_cred = override_creds(id_resolver_cache);
 299         rkey = nfs_idmap_request_key(name, namelen, type, idmap);
 300         revert_creds(saved_cred);
 301
 302         if (IS_ERR(rkey)) {
 303                 ret = PTR_ERR(rkey);
 304                 goto out;
 305         }
 306
 307         rcu_read_lock();
 308         rkey->perm |= KEY_USR_VIEW;
 309
 310         ret = key_validate(rkey);
 311         if (ret < 0)
 312                 goto out_up;
 313
 314         payload = rcu_dereference(rkey->payload.rcudata);
 315         if (IS_ERR_OR_NULL(payload)) {
 316                 ret = PTR_ERR(payload);
 317                 goto out_up;
 318         }
 319
 320         ret = payload->datalen;
 321         if (ret > 0 && ret <= data_size)
 322                 memcpy(data, payload->data, ret);
 323         else
 324                 ret = -EINVAL;
 325
 326 out_up:
 327         rcu_read_unlock();
 328         key_put(rkey);
 329 out:
 330         return ret;
 331 }
 332
 333 /* ID -> Name */
 334 static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf,
 335                                      size_t buflen, struct idmap *idmap)
 336 {
 337         char id_str[NFS_UINT_MAXLEN];
 338         int id_len;
 339         ssize_t ret;
 340
 341         id_len = snprintf(id_str, sizeof(id_str), "%u", id);
 342         ret = nfs_idmap_get_key(id_str, id_len, type, buf, buflen, idmap);
 343         if (ret < 0)
 344                 return -EINVAL;
 345         return ret;
 346 }
 347
 348 /* Name -> ID */
 349 static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *type,
 350                                __u32 *id, struct idmap *idmap)
 351 {
 352         char id_str[NFS_UINT_MAXLEN];
 353         long id_long;
 354         ssize_t data_size;
 355         int ret = 0;
 356
 357         data_size = nfs_idmap_get_key(name, namelen, type, id_str, NFS_UINT_MAXLEN, idmap);
 358         if (data_size <= 0) {
 359                 ret = -EINVAL;
 360         } else {
 361                 ret = kstrtol(id_str, 10, &id_long);
 362                 *id = (__u32)id_long;
 363         }
 364         return ret;
 365 }
 366
 367 /* idmap classic begins here */
 368
 369 enum {
 370         Opt_find_uid, Opt_find_gid, Opt_find_user, Opt_find_group, Opt_find_err
 371 };
 372
 373 static const match_table_t nfs_idmap_tokens = {
 374         { Opt_find_uid, "uid:%s" },
 375         { Opt_find_gid, "gid:%s" },
 376         { Opt_find_user, "user:%s" },
 377         { Opt_find_group, "group:%s" },
 378         { Opt_find_err, NULL }
 379 };
 380
 381 static int nfs_idmap_legacy_upcall(struct key_construction *, const char *, void *);
 382 static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
 383                                    size_t);
 384 static void idmap_release_pipe(struct inode *);
 385 static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
 386
 387 static const struct rpc_pipe_ops idmap_upcall_ops = {
 388         .upcall         = rpc_pipe_generic_upcall,
 389         .downcall       = idmap_pipe_downcall,
 390         .release_pipe   = idmap_release_pipe,
 391         .destroy_msg    = idmap_pipe_destroy_msg,
 392 };
 393
 394 static struct key_type key_type_id_resolver_legacy = {
 395         .name           = "id_legacy",
 396         .instantiate    = user_instantiate,
 397         .match          = user_match,
 398         .revoke         = user_revoke,
 399         .destroy        = user_destroy,
 400         .describe       = user_describe,
 401         .read           = user_read,
 402         .request_key    = nfs_idmap_legacy_upcall,
 403 };
 404
 405 static void __nfs_idmap_unregister(struct rpc_pipe *pipe)
 406 {
 407         if (pipe->dentry)
 408                 rpc_unlink(pipe->dentry);
 409 }
 410
 411 static int __nfs_idmap_register(struct dentry *dir,
 412                                      struct idmap *idmap,
 413                                      struct rpc_pipe *pipe)
 414 {
 415         struct dentry *dentry;
 416
 417         dentry = rpc_mkpipe_dentry(dir, "idmap", idmap, pipe);
 418         if (IS_ERR(dentry))
 419                 return PTR_ERR(dentry);
 420         pipe->dentry = dentry;
 421         return 0;
 422 }
 423
 424 static void nfs_idmap_unregister(struct nfs_client *clp,
 425                                       struct rpc_pipe *pipe)
 426 {
 427         struct net *net = clp->cl_net;
 428         struct super_block *pipefs_sb;
 429
 430         pipefs_sb = rpc_get_sb_net(net);
 431         if (pipefs_sb) {
 432                 __nfs_idmap_unregister(pipe);
 433                 rpc_put_sb_net(net);
 434         }
 435 }
 436
 437 static int nfs_idmap_register(struct nfs_client *clp,
 438                                    struct idmap *idmap,
 439                                    struct rpc_pipe *pipe)
 440 {
 441         struct net *net = clp->cl_net;
 442         struct super_block *pipefs_sb;
 443         int err = 0;
 444
 445         pipefs_sb = rpc_get_sb_net(net);
 446         if (pipefs_sb) {
 447                 if (clp->cl_rpcclient->cl_dentry)
 448                         err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
 449                                                    idmap, pipe);
 450                 rpc_put_sb_net(net);
 451         }
 452         return err;
 453 }
 454
 455 int
 456 nfs_idmap_new(struct nfs_client *clp)
 457 {
 458         struct idmap *idmap;
 459         struct rpc_pipe *pipe;
 460         int error;
 461
 462         idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
 463         if (idmap == NULL)
 464                 return -ENOMEM;
 465
 466         pipe = rpc_mkpipe_data(&idmap_upcall_ops, 0);
 467         if (IS_ERR(pipe)) {
 468                 error = PTR_ERR(pipe);
 469                 kfree(idmap);
 470                 return error;
 471         }
 472         error = nfs_idmap_register(clp, idmap, pipe);
 473         if (error) {
 474                 rpc_destroy_pipe_data(pipe);
 475                 kfree(idmap);
 476                 return error;
 477         }
 478         idmap->idmap_pipe = pipe;
 479         mutex_init(&idmap->idmap_mutex);
 480
 481         clp->cl_idmap = idmap;
 482         return 0;
 483 }
 484
 485 void
 486 nfs_idmap_delete(struct nfs_client *clp)
 487 {
 488         struct idmap *idmap = clp->cl_idmap;
 489
 490         if (!idmap)
 491                 return;
 492         nfs_idmap_unregister(clp, idmap->idmap_pipe);
 493         rpc_destroy_pipe_data(idmap->idmap_pipe);
 494         clp->cl_idmap = NULL;
 495         kfree(idmap);
 496 }
 497
 498 static int __rpc_pipefs_event(struct nfs_client *clp, unsigned long event,
 499                               struct super_block *sb)
 500 {
 501         int err = 0;
 502
 503         switch (event) {
 504         case RPC_PIPEFS_MOUNT:
 505                 err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
 506                                                 clp->cl_idmap,
 507                                                 clp->cl_idmap->idmap_pipe);
 508                 break;
 509         case RPC_PIPEFS_UMOUNT:
 510                 if (clp->cl_idmap->idmap_pipe) {
 511                         struct dentry *parent;
 512
 513                         parent = clp->cl_idmap->idmap_pipe->dentry->d_parent;
 514                         __nfs_idmap_unregister(clp->cl_idmap->idmap_pipe);
 515                         /*
 516                          * Note: This is a dirty hack. SUNRPC hook has been
 517                          * called already but simple_rmdir() call for the
 518                          * directory returned with error because of idmap pipe
 519                          * inside. Thus now we have to remove this directory
 520                          * here.
 521                          */
 522                         if (rpc_rmdir(parent))
 523                                 printk(KERN_ERR "NFS: %s: failed to remove "
 524                                         "clnt dir!\n", __func__);
 525                 }
 526                 break;
 527         default:
 528                 printk(KERN_ERR "NFS: %s: unknown event: %ld\n", __func__,
 529                         event);
 530                 return -ENOTSUPP;
 531         }
 532         return err;
 533 }
 534
 535 static struct nfs_client *nfs_get_client_for_event(struct net *net, int event)
 536 {
 537         struct nfs_net *nn = net_generic(net, nfs_net_id);
 538         struct dentry *cl_dentry;
 539         struct nfs_client *clp;
 540         int err;
 541
 542 restart:
 543         spin_lock(&nn->nfs_client_lock);
 544         list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
 545                 /* Wait for initialisation to finish */
 546                 if (clp->cl_cons_state == NFS_CS_INITING) {
 547                         atomic_inc(&clp->cl_count);
 548                         spin_unlock(&nn->nfs_client_lock);
 549                         err = nfs_wait_client_init_complete(clp);
 550                         nfs_put_client(clp);
 551                         if (err)
 552                                 return NULL;
 553                         goto restart;
 554                 }
 555                 /* Skip nfs_clients that failed to initialise */
 556                 if (clp->cl_cons_state < 0)
 557                         continue;
 558                 smp_rmb();
 559                 if (clp->rpc_ops != &nfs_v4_clientops)
 560                         continue;
 561                 cl_dentry = clp->cl_idmap->idmap_pipe->dentry;
 562                 if (((event == RPC_PIPEFS_MOUNT) && cl_dentry) ||
 563                     ((event == RPC_PIPEFS_UMOUNT) && !cl_dentry))
 564                         continue;
 565                 atomic_inc(&clp->cl_count);
 566                 spin_unlock(&nn->nfs_client_lock);
 567                 return clp;
 568         }
 569         spin_unlock(&nn->nfs_client_lock);
 570         return NULL;
 571 }
 572
 573 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 574                             void *ptr)
 575 {
 576         struct super_block *sb = ptr;
 577         struct nfs_client *clp;
 578         int error = 0;
 579
 580         if (!try_module_get(THIS_MODULE))
 581                 return 0;
 582
 583         while ((clp = nfs_get_client_for_event(sb->s_fs_info, event))) {
 584                 error = __rpc_pipefs_event(clp, event, sb);
 585                 nfs_put_client(clp);
 586                 if (error)
 587                         break;
 588         }
 589         module_put(THIS_MODULE);
 590         return error;
 591 }
 592
 593 #define PIPEFS_NFS_PRIO         1
 594
 595 static struct notifier_block nfs_idmap_block = {
 596         .notifier_call  = rpc_pipefs_event,
 597         .priority       = SUNRPC_PIPEFS_NFS_PRIO,
 598 };
 599
 600 int nfs_idmap_init(void)
 601 {
 602         int ret;
 603         ret = nfs_idmap_init_keyring();
 604         if (ret != 0)
 605                 goto out;
 606         ret = rpc_pipefs_notifier_register(&nfs_idmap_block);
 607         if (ret != 0)
 608                 nfs_idmap_quit_keyring();
 609 out:
 610         return ret;
 611 }
 612
 613 void nfs_idmap_quit(void)
 614 {
 615         rpc_pipefs_notifier_unregister(&nfs_idmap_block);
 616         nfs_idmap_quit_keyring();
 617 }
 618
 619 static int nfs_idmap_prepare_message(char *desc, struct idmap *idmap,
 620                                      struct idmap_msg *im,
 621                                      struct rpc_pipe_msg *msg)
 622 {
 623         substring_t substr;
 624         int token, ret;
 625
 626         im->im_type = IDMAP_TYPE_GROUP;
 627         token = match_token(desc, nfs_idmap_tokens, &substr);
 628
 629         switch (token) {
 630         case Opt_find_uid:
 631                 im->im_type = IDMAP_TYPE_USER;
 632         case Opt_find_gid:
 633                 im->im_conv = IDMAP_CONV_NAMETOID;
 634                 ret = match_strlcpy(im->im_name, &substr, IDMAP_NAMESZ);
 635                 break;
 636
 637         case Opt_find_user:
 638                 im->im_type = IDMAP_TYPE_USER;
 639         case Opt_find_group:
 640                 im->im_conv = IDMAP_CONV_IDTONAME;
 641                 ret = match_int(&substr, &im->im_id);
 642                 break;
 643
 644         default:
 645                 ret = -EINVAL;
 646                 goto out;
 647         }
 648
 649         msg->data = im;
 650         msg->len  = sizeof(struct idmap_msg);
 651
 652 out:
 653         return ret;
 654 }
 655
 656 static bool
 657 nfs_idmap_prepare_pipe_upcall(struct idmap *idmap,
 658                 struct idmap_legacy_upcalldata *data)
 659 {
 660         if (idmap->idmap_upcall_data != NULL) {
 661                 WARN_ON_ONCE(1);
 662                 return false;
 663         }
 664         idmap->idmap_upcall_data = data;
 665         return true;
 666 }
 667
 668 static void
 669 nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, int ret)
 670 {
 671         struct key_construction *cons = idmap->idmap_upcall_data->key_cons;
 672
 673         kfree(idmap->idmap_upcall_data);
 674         idmap->idmap_upcall_data = NULL;
 675         complete_request_key(cons, ret);
 676 }
 677
 678 static void
 679 nfs_idmap_abort_pipe_upcall(struct idmap *idmap, int ret)
 680 {
 681         if (idmap->idmap_upcall_data != NULL)
 682                 nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
 683 }
 684
 685 static int nfs_idmap_legacy_upcall(struct key_construction *cons,
 686                                    const char *op,
 687                                    void *aux)
 688 {
 689         struct idmap_legacy_upcalldata *data;
 690         struct rpc_pipe_msg *msg;
 691         struct idmap_msg *im;
 692         struct idmap *idmap = (struct idmap *)aux;
 693         struct key *key = cons->key;
 694         int ret = -ENOMEM;
 695
 696         /* msg and im are freed in idmap_pipe_destroy_msg */
 697         data = kzalloc(sizeof(*data), GFP_KERNEL);
 698         if (!data)
 699                 goto out1;
 700
 701         msg = &data->pipe_msg;
 702         im = &data->idmap_msg;
 703         data->idmap = idmap;
 704         data->key_cons = cons;
 705
 706         ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);
 707         if (ret < 0)
 708                 goto out2;
 709
 710         ret = -EAGAIN;
 711         if (!nfs_idmap_prepare_pipe_upcall(idmap, data))
 712                 goto out2;
 713
 714         ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
 715         if (ret < 0)
 716                 nfs_idmap_abort_pipe_upcall(idmap, ret);
 717
 718         return ret;
 719 out2:
 720         kfree(data);
 721 out1:
 722         complete_request_key(cons, ret);
 723         return ret;
 724 }
 725
 726 static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *data, size_t datalen)
 727 {
 728         return key_instantiate_and_link(key, data, datalen,
 729                                         id_resolver_cache->thread_keyring,
 730                                         authkey);
 731 }
 732
 733 static int nfs_idmap_read_and_verify_message(struct idmap_msg *im,
 734                 struct idmap_msg *upcall,
 735                 struct key *key, struct key *authkey)
 736 {
 737         char id_str[NFS_UINT_MAXLEN];
 738         size_t len;
 739         int ret = -ENOKEY;
 740
 741         /* ret = -ENOKEY */
 742         if (upcall->im_type != im->im_type || upcall->im_conv != im->im_conv)
 743                 goto out;
 744         switch (im->im_conv) {
 745         case IDMAP_CONV_NAMETOID:
 746                 if (strcmp(upcall->im_name, im->im_name) != 0)
 747                         break;
 748                 /* Note: here we store the NUL terminator too */
 749                 len = sprintf(id_str, "%d", im->im_id) + 1;
 750                 ret = nfs_idmap_instantiate(key, authkey, id_str, len);
 751                 break;
 752         case IDMAP_CONV_IDTONAME:
 753                 if (upcall->im_id != im->im_id)
 754                         break;
 755                 len = strlen(im->im_name);
 756                 ret = nfs_idmap_instantiate(key, authkey, im->im_name, len);
 757                 break;
 758         default:
 759                 ret = -EINVAL;
 760         }
 761 out:
 762         return ret;
 763 }
 764
 765 static ssize_t
 766 idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 767 {
 768         struct rpc_inode *rpci = RPC_I(file_inode(filp));
 769         struct idmap *idmap = (struct idmap *)rpci->private;
 770         struct key_construction *cons;
 771         struct idmap_msg im;
 772         size_t namelen_in;
 773         int ret = -ENOKEY;
 774
 775         /* If instantiation is successful, anyone waiting for key construction
 776          * will have been woken up and someone else may now have used
 777          * idmap_key_cons - so after this point we may no longer touch it.
 778          */
 779         if (idmap->idmap_upcall_data == NULL)
 780                 goto out_noupcall;
 781
 782         cons = idmap->idmap_upcall_data->key_cons;
 783
 784         if (mlen != sizeof(im)) {
 785                 ret = -ENOSPC;
 786                 goto out;
 787         }
 788
 789         if (copy_from_user(&im, src, mlen) != 0) {
 790                 ret = -EFAULT;
 791                 goto out;
 792         }
 793
 794         if (!(im.im_status & IDMAP_STATUS_SUCCESS)) {
 795                 ret = -ENOKEY;
 796                 goto out;
 797         }
 798
 799         namelen_in = strnlen(im.im_name, IDMAP_NAMESZ);
 800         if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
 801                 ret = -EINVAL;
 802                 goto out;
 803 }
 804
 805         ret = nfs_idmap_read_and_verify_message(&im,
 806                         &idmap->idmap_upcall_data->idmap_msg,
 807                         cons->key, cons->authkey);
 808         if (ret >= 0) {
 809                 key_set_timeout(cons->key, nfs_idmap_cache_timeout);
 810                 ret = mlen;
 811         }
 812
 813 out:
 814         nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
 815 out_noupcall:
 816         return ret;
 817 }
 818
 819 static void
 820 idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 821 {
 822         struct idmap_legacy_upcalldata *data = container_of(msg,
 823                         struct idmap_legacy_upcalldata,
 824                         pipe_msg);
 825         struct idmap *idmap = data->idmap;
 826
 827         if (msg->errno)
 828                 nfs_idmap_abort_pipe_upcall(idmap, msg->errno);
 829 }
 830
 831 static void
 832 idmap_release_pipe(struct inode *inode)
 833 {
 834         struct rpc_inode *rpci = RPC_I(inode);
 835         struct idmap *idmap = (struct idmap *)rpci->private;
 836
 837         nfs_idmap_abort_pipe_upcall(idmap, -EPIPE);
 838 }
 839
 840 int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, kuid_t *uid)
 841 {
 842         struct idmap *idmap = server->nfs_client->cl_idmap;
 843         __u32 id = -1;
 844         int ret = 0;
 845
 846         if (!nfs_map_string_to_numeric(name, namelen, &id))
 847                 ret = nfs_idmap_lookup_id(name, namelen, "uid", &id, idmap);
 848         if (ret == 0) {
 849                 *uid = make_kuid(&init_user_ns, id);
 850                 if (!uid_valid(*uid))
 851                         ret = -ERANGE;
 852         }
 853         trace_nfs4_map_name_to_uid(name, namelen, id, ret);
 854         return ret;
 855 }
 856
 857 int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, kgid_t *gid)
 858 {
 859         struct idmap *idmap = server->nfs_client->cl_idmap;
 860         __u32 id = -1;
 861         int ret = 0;
 862
 863         if (!nfs_map_string_to_numeric(name, namelen, &id))
 864                 ret = nfs_idmap_lookup_id(name, namelen, "gid", &id, idmap);
 865         if (ret == 0) {
 866                 *gid = make_kgid(&init_user_ns, id);
 867                 if (!gid_valid(*gid))
 868                         ret = -ERANGE;
 869         }
 870         trace_nfs4_map_group_to_gid(name, namelen, id, ret);
 871         return ret;
 872 }
 873
 874 int nfs_map_uid_to_name(const struct nfs_server *server, kuid_t uid, char *buf, size_t buflen)
 875 {
 876         struct idmap *idmap = server->nfs_client->cl_idmap;
 877         int ret = -EINVAL;
 878         __u32 id;
 879
 880         id = from_kuid(&init_user_ns, uid);
 881         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 882                 ret = nfs_idmap_lookup_name(id, "user", buf, buflen, idmap);
 883         if (ret < 0)
 884                 ret = nfs_map_numeric_to_string(id, buf, buflen);
 885         trace_nfs4_map_uid_to_name(buf, ret, id, ret);
 886         return ret;
 887 }
 888 int nfs_map_gid_to_group(const struct nfs_server *server, kgid_t gid, char *buf, size_t buflen)
 889 {
 890         struct idmap *idmap = server->nfs_client->cl_idmap;
 891         int ret = -EINVAL;
 892         __u32 id;
 893
 894         id = from_kgid(&init_user_ns, gid);
 895         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 896                 ret = nfs_idmap_lookup_name(id, "group", buf, buflen, idmap);
 897         if (ret < 0)
 898                 ret = nfs_map_numeric_to_string(id, buf, buflen);
 899         trace_nfs4_map_gid_to_group(buf, ret, id, ret);
 900         return ret;
 901 }