linux/fs/nfs/idmap.c
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   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
  55static const struct cred *id_resolver_cache;
  56static struct key_type key_type_id_resolver_legacy;
  57
  58struct 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
  65struct 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 */
  77void 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
  85static 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
  91static 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
  97static 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
 111static 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 */
 129void 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 */
 145void 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
 153static 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
 168static int nfs_map_numeric_to_string(__u32 id, char *buf, size_t buflen)
 169{
 170        return snprintf(buf, buflen, "%u", id);
 171}
 172
 173static 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
 183static 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
 223failed_reg_legacy:
 224        unregister_key_type(&key_type_id_resolver);
 225failed_put_key:
 226        key_put(keyring);
 227failed_put_cred:
 228        put_cred(cred);
 229        return ret;
 230}
 231
 232static 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 */
 247static 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
 268static 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
 315out_up:
 316        rcu_read_unlock();
 317        key_put(rkey);
 318out:
 319        return ret;
 320}
 321
 322static 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 */
 340static 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 */
 355static 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
 375enum {
 376        Opt_find_uid, Opt_find_gid, Opt_find_user, Opt_find_group, Opt_find_err
 377};
 378
 379static 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
 387static int nfs_idmap_legacy_upcall(struct key_construction *, const char *, void *);
 388static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
 389                                   size_t);
 390static void idmap_release_pipe(struct inode *);
 391static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
 392
 393static 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
 400static 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
 411static void __nfs_idmap_unregister(struct rpc_pipe *pipe)
 412{
 413        if (pipe->dentry)
 414                rpc_unlink(pipe->dentry);
 415}
 416
 417static 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
 430static 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
 443static 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
 461int
 462nfs_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
 491void
 492nfs_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
 504static 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
 541static 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
 548restart:
 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
 579static 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
 601static struct notifier_block nfs_idmap_block = {
 602        .notifier_call  = rpc_pipefs_event,
 603        .priority       = SUNRPC_PIPEFS_NFS_PRIO,
 604};
 605
 606int 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();
 615out:
 616        return ret;
 617}
 618
 619void nfs_idmap_quit(void)
 620{
 621        rpc_pipefs_notifier_unregister(&nfs_idmap_block);
 622        nfs_idmap_quit_keyring();
 623}
 624
 625static 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
 658out:
 659        return ret;
 660}
 661
 662static bool
 663nfs_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
 674static void
 675nfs_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
 684static void
 685nfs_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
 691static 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;
 725out2:
 726        kfree(data);
 727out1:
 728        complete_request_key(cons, ret);
 729        return ret;
 730}
 731
 732static 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
 739static 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        }
 764out:
 765        return ret;
 766}
 767
 768static ssize_t
 769idmap_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
 816out:
 817        nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
 818out_noupcall:
 819        return ret;
 820}
 821
 822static void
 823idmap_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
 834static void
 835idmap_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
 843int 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
 852int 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
 861int 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}
 872int 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}
 883
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