net/sunrpc/auth_gss/auth_gss.c

   1 /*
   2  * linux/net/sunrpc/auth_gss/auth_gss.c
   3  *
   4  * RPCSEC_GSS client authentication.
   5  *
   6  *  Copyright (c) 2000 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Dug Song       <dugsong@monkey.org>
  10  *  Andy Adamson   <andros@umich.edu>
  11  *
  12  *  Redistribution and use in source and binary forms, with or without
  13  *  modification, are permitted provided that the following conditions
  14  *  are met:
  15  *
  16  *  1. Redistributions of source code must retain the above copyright
  17  *     notice, this list of conditions and the following disclaimer.
  18  *  2. Redistributions in binary form must reproduce the above copyright
  19  *     notice, this list of conditions and the following disclaimer in the
  20  *     documentation and/or other materials provided with the distribution.
  21  *  3. Neither the name of the University nor the names of its
  22  *     contributors may be used to endorse or promote products derived
  23  *     from this software without specific prior written permission.
  24  *
  25  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  26  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  27  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  28  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  32  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  33  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  34  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  35  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38
  39 #include <linux/module.h>
  40 #include <linux/init.h>
  41 #include <linux/types.h>
  42 #include <linux/slab.h>
  43 #include <linux/sched.h>
  44 #include <linux/pagemap.h>
  45 #include <linux/sunrpc/clnt.h>
  46 #include <linux/sunrpc/auth.h>
  47 #include <linux/sunrpc/auth_gss.h>
  48 #include <linux/sunrpc/svcauth_gss.h>
  49 #include <linux/sunrpc/gss_err.h>
  50 #include <linux/workqueue.h>
  51 #include <linux/sunrpc/rpc_pipe_fs.h>
  52 #include <linux/sunrpc/gss_api.h>
  53 #include <asm/uaccess.h>
  54 #include <linux/hashtable.h>
  55
  56 #include "../netns.h"
  57
  58 static const struct rpc_authops authgss_ops;
  59
  60 static const struct rpc_credops gss_credops;
  61 static const struct rpc_credops gss_nullops;
  62
  63 #define GSS_RETRY_EXPIRED 5
  64 static unsigned int gss_expired_cred_retry_delay = GSS_RETRY_EXPIRED;
  65
  66 #define GSS_KEY_EXPIRE_TIMEO 240
  67 static unsigned int gss_key_expire_timeo = GSS_KEY_EXPIRE_TIMEO;
  68
  69 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  70 # define RPCDBG_FACILITY        RPCDBG_AUTH
  71 #endif
  72
  73 #define GSS_CRED_SLACK          (RPC_MAX_AUTH_SIZE * 2)
  74 /* length of a krb5 verifier (48), plus data added before arguments when
  75  * using integrity (two 4-byte integers): */
  76 #define GSS_VERF_SLACK          100
  77
  78 static DEFINE_HASHTABLE(gss_auth_hash_table, 4);
  79 static DEFINE_SPINLOCK(gss_auth_hash_lock);
  80
  81 struct gss_pipe {
  82         struct rpc_pipe_dir_object pdo;
  83         struct rpc_pipe *pipe;
  84         struct rpc_clnt *clnt;
  85         const char *name;
  86         struct kref kref;
  87 };
  88
  89 struct gss_auth {
  90         struct kref kref;
  91         struct hlist_node hash;
  92         struct rpc_auth rpc_auth;
  93         struct gss_api_mech *mech;
  94         enum rpc_gss_svc service;
  95         struct rpc_clnt *client;
  96         struct net *net;
  97         /*
  98          * There are two upcall pipes; dentry[1], named "gssd", is used
  99          * for the new text-based upcall; dentry[0] is named after the
 100          * mechanism (for example, "krb5") and exists for
 101          * backwards-compatibility with older gssd's.
 102          */
 103         struct gss_pipe *gss_pipe[2];
 104         const char *target_name;
 105 };
 106
 107 /* pipe_version >= 0 if and only if someone has a pipe open. */
 108 static DEFINE_SPINLOCK(pipe_version_lock);
 109 static struct rpc_wait_queue pipe_version_rpc_waitqueue;
 110 static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
 111 static void gss_put_auth(struct gss_auth *gss_auth);
 112
 113 static void gss_free_ctx(struct gss_cl_ctx *);
 114 static const struct rpc_pipe_ops gss_upcall_ops_v0;
 115 static const struct rpc_pipe_ops gss_upcall_ops_v1;
 116
 117 static inline struct gss_cl_ctx *
 118 gss_get_ctx(struct gss_cl_ctx *ctx)
 119 {
 120         atomic_inc(&ctx->count);
 121         return ctx;
 122 }
 123
 124 static inline void
 125 gss_put_ctx(struct gss_cl_ctx *ctx)
 126 {
 127         if (atomic_dec_and_test(&ctx->count))
 128                 gss_free_ctx(ctx);
 129 }
 130
 131 /* gss_cred_set_ctx:
 132  * called by gss_upcall_callback and gss_create_upcall in order
 133  * to set the gss context. The actual exchange of an old context
 134  * and a new one is protected by the pipe->lock.
 135  */
 136 static void
 137 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 138 {
 139         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 140
 141         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 142                 return;
 143         gss_get_ctx(ctx);
 144         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 145         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 146         smp_mb__before_atomic();
 147         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 148 }
 149
 150 static const void *
 151 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 152 {
 153         const void *q = (const void *)((const char *)p + len);
 154         if (unlikely(q > end || q < p))
 155                 return ERR_PTR(-EFAULT);
 156         memcpy(res, p, len);
 157         return q;
 158 }
 159
 160 static inline const void *
 161 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 162 {
 163         const void *q;
 164         unsigned int len;
 165
 166         p = simple_get_bytes(p, end, &len, sizeof(len));
 167         if (IS_ERR(p))
 168                 return p;
 169         q = (const void *)((const char *)p + len);
 170         if (unlikely(q > end || q < p))
 171                 return ERR_PTR(-EFAULT);
 172         dest->data = kmemdup(p, len, GFP_NOFS);
 173         if (unlikely(dest->data == NULL))
 174                 return ERR_PTR(-ENOMEM);
 175         dest->len = len;
 176         return q;
 177 }
 178
 179 static struct gss_cl_ctx *
 180 gss_cred_get_ctx(struct rpc_cred *cred)
 181 {
 182         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 183         struct gss_cl_ctx *ctx = NULL;
 184
 185         rcu_read_lock();
 186         ctx = rcu_dereference(gss_cred->gc_ctx);
 187         if (ctx)
 188                 gss_get_ctx(ctx);
 189         rcu_read_unlock();
 190         return ctx;
 191 }
 192
 193 static struct gss_cl_ctx *
 194 gss_alloc_context(void)
 195 {
 196         struct gss_cl_ctx *ctx;
 197
 198         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
 199         if (ctx != NULL) {
 200                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 201                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 202                 spin_lock_init(&ctx->gc_seq_lock);
 203                 atomic_set(&ctx->count,1);
 204         }
 205         return ctx;
 206 }
 207
 208 #define GSSD_MIN_TIMEOUT (60 * 60)
 209 static const void *
 210 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 211 {
 212         const void *q;
 213         unsigned int seclen;
 214         unsigned int timeout;
 215         unsigned long now = jiffies;
 216         u32 window_size;
 217         int ret;
 218
 219         /* First unsigned int gives the remaining lifetime in seconds of the
 220          * credential - e.g. the remaining TGT lifetime for Kerberos or
 221          * the -t value passed to GSSD.
 222          */
 223         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 224         if (IS_ERR(p))
 225                 goto err;
 226         if (timeout == 0)
 227                 timeout = GSSD_MIN_TIMEOUT;
 228         ctx->gc_expiry = now + ((unsigned long)timeout * HZ);
 229         /* Sequence number window. Determines the maximum number of
 230          * simultaneous requests
 231          */
 232         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 233         if (IS_ERR(p))
 234                 goto err;
 235         ctx->gc_win = window_size;
 236         /* gssd signals an error by passing ctx->gc_win = 0: */
 237         if (ctx->gc_win == 0) {
 238                 /*
 239                  * in which case, p points to an error code. Anything other
 240                  * than -EKEYEXPIRED gets converted to -EACCES.
 241                  */
 242                 p = simple_get_bytes(p, end, &ret, sizeof(ret));
 243                 if (!IS_ERR(p))
 244                         p = (ret == -EKEYEXPIRED) ? ERR_PTR(-EKEYEXPIRED) :
 245                                                     ERR_PTR(-EACCES);
 246                 goto err;
 247         }
 248         /* copy the opaque wire context */
 249         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 250         if (IS_ERR(p))
 251                 goto err;
 252         /* import the opaque security context */
 253         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 254         if (IS_ERR(p))
 255                 goto err;
 256         q = (const void *)((const char *)p + seclen);
 257         if (unlikely(q > end || q < p)) {
 258                 p = ERR_PTR(-EFAULT);
 259                 goto err;
 260         }
 261         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, NULL, GFP_NOFS);
 262         if (ret < 0) {
 263                 p = ERR_PTR(ret);
 264                 goto err;
 265         }
 266
 267         /* is there any trailing data? */
 268         if (q == end) {
 269                 p = q;
 270                 goto done;
 271         }
 272
 273         /* pull in acceptor name (if there is one) */
 274         p = simple_get_netobj(q, end, &ctx->gc_acceptor);
 275         if (IS_ERR(p))
 276                 goto err;
 277 done:
 278         dprintk("RPC:       %s Success. gc_expiry %lu now %lu timeout %u acceptor %.*s\n",
 279                 __func__, ctx->gc_expiry, now, timeout, ctx->gc_acceptor.len,
 280                 ctx->gc_acceptor.data);
 281         return p;
 282 err:
 283         dprintk("RPC:       %s returns error %ld\n", __func__, -PTR_ERR(p));
 284         return p;
 285 }
 286
 287 #define UPCALL_BUF_LEN 128
 288
 289 struct gss_upcall_msg {
 290         atomic_t count;
 291         kuid_t  uid;
 292         struct rpc_pipe_msg msg;
 293         struct list_head list;
 294         struct gss_auth *auth;
 295         struct rpc_pipe *pipe;
 296         struct rpc_wait_queue rpc_waitqueue;
 297         wait_queue_head_t waitqueue;
 298         struct gss_cl_ctx *ctx;
 299         char databuf[UPCALL_BUF_LEN];
 300 };
 301
 302 static int get_pipe_version(struct net *net)
 303 {
 304         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 305         int ret;
 306
 307         spin_lock(&pipe_version_lock);
 308         if (sn->pipe_version >= 0) {
 309                 atomic_inc(&sn->pipe_users);
 310                 ret = sn->pipe_version;
 311         } else
 312                 ret = -EAGAIN;
 313         spin_unlock(&pipe_version_lock);
 314         return ret;
 315 }
 316
 317 static void put_pipe_version(struct net *net)
 318 {
 319         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 320
 321         if (atomic_dec_and_lock(&sn->pipe_users, &pipe_version_lock)) {
 322                 sn->pipe_version = -1;
 323                 spin_unlock(&pipe_version_lock);
 324         }
 325 }
 326
 327 static void
 328 gss_release_msg(struct gss_upcall_msg *gss_msg)
 329 {
 330         struct net *net = gss_msg->auth->net;
 331         if (!atomic_dec_and_test(&gss_msg->count))
 332                 return;
 333         put_pipe_version(net);
 334         BUG_ON(!list_empty(&gss_msg->list));
 335         if (gss_msg->ctx != NULL)
 336                 gss_put_ctx(gss_msg->ctx);
 337         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 338         gss_put_auth(gss_msg->auth);
 339         kfree(gss_msg);
 340 }
 341
 342 static struct gss_upcall_msg *
 343 __gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid)
 344 {
 345         struct gss_upcall_msg *pos;
 346         list_for_each_entry(pos, &pipe->in_downcall, list) {
 347                 if (!uid_eq(pos->uid, uid))
 348                         continue;
 349                 atomic_inc(&pos->count);
 350                 dprintk("RPC:       %s found msg %p\n", __func__, pos);
 351                 return pos;
 352         }
 353         dprintk("RPC:       %s found nothing\n", __func__);
 354         return NULL;
 355 }
 356
 357 /* Try to add an upcall to the pipefs queue.
 358  * If an upcall owned by our uid already exists, then we return a reference
 359  * to that upcall instead of adding the new upcall.
 360  */
 361 static inline struct gss_upcall_msg *
 362 gss_add_msg(struct gss_upcall_msg *gss_msg)
 363 {
 364         struct rpc_pipe *pipe = gss_msg->pipe;
 365         struct gss_upcall_msg *old;
 366
 367         spin_lock(&pipe->lock);
 368         old = __gss_find_upcall(pipe, gss_msg->uid);
 369         if (old == NULL) {
 370                 atomic_inc(&gss_msg->count);
 371                 list_add(&gss_msg->list, &pipe->in_downcall);
 372         } else
 373                 gss_msg = old;
 374         spin_unlock(&pipe->lock);
 375         return gss_msg;
 376 }
 377
 378 static void
 379 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 380 {
 381         list_del_init(&gss_msg->list);
 382         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 383         wake_up_all(&gss_msg->waitqueue);
 384         atomic_dec(&gss_msg->count);
 385 }
 386
 387 static void
 388 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 389 {
 390         struct rpc_pipe *pipe = gss_msg->pipe;
 391
 392         if (list_empty(&gss_msg->list))
 393                 return;
 394         spin_lock(&pipe->lock);
 395         if (!list_empty(&gss_msg->list))
 396                 __gss_unhash_msg(gss_msg);
 397         spin_unlock(&pipe->lock);
 398 }
 399
 400 static void
 401 gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
 402 {
 403         switch (gss_msg->msg.errno) {
 404         case 0:
 405                 if (gss_msg->ctx == NULL)
 406                         break;
 407                 clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 408                 gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
 409                 break;
 410         case -EKEYEXPIRED:
 411                 set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 412         }
 413         gss_cred->gc_upcall_timestamp = jiffies;
 414         gss_cred->gc_upcall = NULL;
 415         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 416 }
 417
 418 static void
 419 gss_upcall_callback(struct rpc_task *task)
 420 {
 421         struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
 422                         struct gss_cred, gc_base);
 423         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 424         struct rpc_pipe *pipe = gss_msg->pipe;
 425
 426         spin_lock(&pipe->lock);
 427         gss_handle_downcall_result(gss_cred, gss_msg);
 428         spin_unlock(&pipe->lock);
 429         task->tk_status = gss_msg->msg.errno;
 430         gss_release_msg(gss_msg);
 431 }
 432
 433 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
 434 {
 435         uid_t uid = from_kuid(&init_user_ns, gss_msg->uid);
 436         memcpy(gss_msg->databuf, &uid, sizeof(uid));
 437         gss_msg->msg.data = gss_msg->databuf;
 438         gss_msg->msg.len = sizeof(uid);
 439
 440         BUILD_BUG_ON(sizeof(uid) > sizeof(gss_msg->databuf));
 441 }
 442
 443 static int gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
 444                                 const char *service_name,
 445                                 const char *target_name)
 446 {
 447         struct gss_api_mech *mech = gss_msg->auth->mech;
 448         char *p = gss_msg->databuf;
 449         size_t buflen = sizeof(gss_msg->databuf);
 450         int len;
 451
 452         len = scnprintf(p, buflen, "mech=%s uid=%d ", mech->gm_name,
 453                         from_kuid(&init_user_ns, gss_msg->uid));
 454         buflen -= len;
 455         p += len;
 456         gss_msg->msg.len = len;
 457         if (target_name) {
 458                 len = scnprintf(p, buflen, "target=%s ", target_name);
 459                 buflen -= len;
 460                 p += len;
 461                 gss_msg->msg.len += len;
 462         }
 463         if (service_name != NULL) {
 464                 len = scnprintf(p, buflen, "service=%s ", service_name);
 465                 buflen -= len;
 466                 p += len;
 467                 gss_msg->msg.len += len;
 468         }
 469         if (mech->gm_upcall_enctypes) {
 470                 len = scnprintf(p, buflen, "enctypes=%s ",
 471                                 mech->gm_upcall_enctypes);
 472                 buflen -= len;
 473                 p += len;
 474                 gss_msg->msg.len += len;
 475         }
 476         len = scnprintf(p, buflen, "\n");
 477         if (len == 0)
 478                 goto out_overflow;
 479         gss_msg->msg.len += len;
 480
 481         gss_msg->msg.data = gss_msg->databuf;
 482         return 0;
 483 out_overflow:
 484         WARN_ON_ONCE(1);
 485         return -ENOMEM;
 486 }
 487
 488 static struct gss_upcall_msg *
 489 gss_alloc_msg(struct gss_auth *gss_auth,
 490                 kuid_t uid, const char *service_name)
 491 {
 492         struct gss_upcall_msg *gss_msg;
 493         int vers;
 494         int err = -ENOMEM;
 495
 496         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 497         if (gss_msg == NULL)
 498                 goto err;
 499         vers = get_pipe_version(gss_auth->net);
 500         err = vers;
 501         if (err < 0)
 502                 goto err_free_msg;
 503         gss_msg->pipe = gss_auth->gss_pipe[vers]->pipe;
 504         INIT_LIST_HEAD(&gss_msg->list);
 505         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 506         init_waitqueue_head(&gss_msg->waitqueue);
 507         atomic_set(&gss_msg->count, 1);
 508         gss_msg->uid = uid;
 509         gss_msg->auth = gss_auth;
 510         switch (vers) {
 511         case 0:
 512                 gss_encode_v0_msg(gss_msg);
 513                 break;
 514         default:
 515                 err = gss_encode_v1_msg(gss_msg, service_name, gss_auth->target_name);
 516                 if (err)
 517                         goto err_put_pipe_version;
 518         };
 519         kref_get(&gss_auth->kref);
 520         return gss_msg;
 521 err_put_pipe_version:
 522         put_pipe_version(gss_auth->net);
 523 err_free_msg:
 524         kfree(gss_msg);
 525 err:
 526         return ERR_PTR(err);
 527 }
 528
 529 static struct gss_upcall_msg *
 530 gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred)
 531 {
 532         struct gss_cred *gss_cred = container_of(cred,
 533                         struct gss_cred, gc_base);
 534         struct gss_upcall_msg *gss_new, *gss_msg;
 535         kuid_t uid = cred->cr_uid;
 536
 537         gss_new = gss_alloc_msg(gss_auth, uid, gss_cred->gc_principal);
 538         if (IS_ERR(gss_new))
 539                 return gss_new;
 540         gss_msg = gss_add_msg(gss_new);
 541         if (gss_msg == gss_new) {
 542                 int res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
 543                 if (res) {
 544                         gss_unhash_msg(gss_new);
 545                         gss_msg = ERR_PTR(res);
 546                 }
 547         } else
 548                 gss_release_msg(gss_new);
 549         return gss_msg;
 550 }
 551
 552 static void warn_gssd(void)
 553 {
 554         dprintk("AUTH_GSS upcall failed. Please check user daemon is running.\n");
 555 }
 556
 557 static inline int
 558 gss_refresh_upcall(struct rpc_task *task)
 559 {
 560         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 561         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 562                         struct gss_auth, rpc_auth);
 563         struct gss_cred *gss_cred = container_of(cred,
 564                         struct gss_cred, gc_base);
 565         struct gss_upcall_msg *gss_msg;
 566         struct rpc_pipe *pipe;
 567         int err = 0;
 568
 569         dprintk("RPC: %5u %s for uid %u\n",
 570                 task->tk_pid, __func__, from_kuid(&init_user_ns, cred->cr_uid));
 571         gss_msg = gss_setup_upcall(gss_auth, cred);
 572         if (PTR_ERR(gss_msg) == -EAGAIN) {
 573                 /* XXX: warning on the first, under the assumption we
 574                  * shouldn't normally hit this case on a refresh. */
 575                 warn_gssd();
 576                 task->tk_timeout = 15*HZ;
 577                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
 578                 return -EAGAIN;
 579         }
 580         if (IS_ERR(gss_msg)) {
 581                 err = PTR_ERR(gss_msg);
 582                 goto out;
 583         }
 584         pipe = gss_msg->pipe;
 585         spin_lock(&pipe->lock);
 586         if (gss_cred->gc_upcall != NULL)
 587                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 588         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 589                 task->tk_timeout = 0;
 590                 gss_cred->gc_upcall = gss_msg;
 591                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 592                 atomic_inc(&gss_msg->count);
 593                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 594         } else {
 595                 gss_handle_downcall_result(gss_cred, gss_msg);
 596                 err = gss_msg->msg.errno;
 597         }
 598         spin_unlock(&pipe->lock);
 599         gss_release_msg(gss_msg);
 600 out:
 601         dprintk("RPC: %5u %s for uid %u result %d\n",
 602                 task->tk_pid, __func__,
 603                 from_kuid(&init_user_ns, cred->cr_uid), err);
 604         return err;
 605 }
 606
 607 static inline int
 608 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 609 {
 610         struct net *net = gss_auth->net;
 611         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 612         struct rpc_pipe *pipe;
 613         struct rpc_cred *cred = &gss_cred->gc_base;
 614         struct gss_upcall_msg *gss_msg;
 615         DEFINE_WAIT(wait);
 616         int err;
 617
 618         dprintk("RPC:       %s for uid %u\n",
 619                 __func__, from_kuid(&init_user_ns, cred->cr_uid));
 620 retry:
 621         err = 0;
 622         /* if gssd is down, just skip upcalling altogether */
 623         if (!gssd_running(net)) {
 624                 warn_gssd();
 625                 return -EACCES;
 626         }
 627         gss_msg = gss_setup_upcall(gss_auth, cred);
 628         if (PTR_ERR(gss_msg) == -EAGAIN) {
 629                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
 630                                 sn->pipe_version >= 0, 15 * HZ);
 631                 if (sn->pipe_version < 0) {
 632                         warn_gssd();
 633                         err = -EACCES;
 634                 }
 635                 if (err < 0)
 636                         goto out;
 637                 goto retry;
 638         }
 639         if (IS_ERR(gss_msg)) {
 640                 err = PTR_ERR(gss_msg);
 641                 goto out;
 642         }
 643         pipe = gss_msg->pipe;
 644         for (;;) {
 645                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
 646                 spin_lock(&pipe->lock);
 647                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 648                         break;
 649                 }
 650                 spin_unlock(&pipe->lock);
 651                 if (fatal_signal_pending(current)) {
 652                         err = -ERESTARTSYS;
 653                         goto out_intr;
 654                 }
 655                 schedule();
 656         }
 657         if (gss_msg->ctx)
 658                 gss_cred_set_ctx(cred, gss_msg->ctx);
 659         else
 660                 err = gss_msg->msg.errno;
 661         spin_unlock(&pipe->lock);
 662 out_intr:
 663         finish_wait(&gss_msg->waitqueue, &wait);
 664         gss_release_msg(gss_msg);
 665 out:
 666         dprintk("RPC:       %s for uid %u result %d\n",
 667                 __func__, from_kuid(&init_user_ns, cred->cr_uid), err);
 668         return err;
 669 }
 670
 671 #define MSG_BUF_MAXSIZE 1024
 672
 673 static ssize_t
 674 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 675 {
 676         const void *p, *end;
 677         void *buf;
 678         struct gss_upcall_msg *gss_msg;
 679         struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
 680         struct gss_cl_ctx *ctx;
 681         uid_t id;
 682         kuid_t uid;
 683         ssize_t err = -EFBIG;
 684
 685         if (mlen > MSG_BUF_MAXSIZE)
 686                 goto out;
 687         err = -ENOMEM;
 688         buf = kmalloc(mlen, GFP_NOFS);
 689         if (!buf)
 690                 goto out;
 691
 692         err = -EFAULT;
 693         if (copy_from_user(buf, src, mlen))
 694                 goto err;
 695
 696         end = (const void *)((char *)buf + mlen);
 697         p = simple_get_bytes(buf, end, &id, sizeof(id));
 698         if (IS_ERR(p)) {
 699                 err = PTR_ERR(p);
 700                 goto err;
 701         }
 702
 703         uid = make_kuid(&init_user_ns, id);
 704         if (!uid_valid(uid)) {
 705                 err = -EINVAL;
 706                 goto err;
 707         }
 708
 709         err = -ENOMEM;
 710         ctx = gss_alloc_context();
 711         if (ctx == NULL)
 712                 goto err;
 713
 714         err = -ENOENT;
 715         /* Find a matching upcall */
 716         spin_lock(&pipe->lock);
 717         gss_msg = __gss_find_upcall(pipe, uid);
 718         if (gss_msg == NULL) {
 719                 spin_unlock(&pipe->lock);
 720                 goto err_put_ctx;
 721         }
 722         list_del_init(&gss_msg->list);
 723         spin_unlock(&pipe->lock);
 724
 725         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 726         if (IS_ERR(p)) {
 727                 err = PTR_ERR(p);
 728                 switch (err) {
 729                 case -EACCES:
 730                 case -EKEYEXPIRED:
 731                         gss_msg->msg.errno = err;
 732                         err = mlen;
 733                         break;
 734                 case -EFAULT:
 735                 case -ENOMEM:
 736                 case -EINVAL:
 737                 case -ENOSYS:
 738                         gss_msg->msg.errno = -EAGAIN;
 739                         break;
 740                 default:
 741                         printk(KERN_CRIT "%s: bad return from "
 742                                 "gss_fill_context: %zd\n", __func__, err);
 743                         gss_msg->msg.errno = -EIO;
 744                 }
 745                 goto err_release_msg;
 746         }
 747         gss_msg->ctx = gss_get_ctx(ctx);
 748         err = mlen;
 749
 750 err_release_msg:
 751         spin_lock(&pipe->lock);
 752         __gss_unhash_msg(gss_msg);
 753         spin_unlock(&pipe->lock);
 754         gss_release_msg(gss_msg);
 755 err_put_ctx:
 756         gss_put_ctx(ctx);
 757 err:
 758         kfree(buf);
 759 out:
 760         dprintk("RPC:       %s returning %Zd\n", __func__, err);
 761         return err;
 762 }
 763
 764 static int gss_pipe_open(struct inode *inode, int new_version)
 765 {
 766         struct net *net = inode->i_sb->s_fs_info;
 767         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 768         int ret = 0;
 769
 770         spin_lock(&pipe_version_lock);
 771         if (sn->pipe_version < 0) {
 772                 /* First open of any gss pipe determines the version: */
 773                 sn->pipe_version = new_version;
 774                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 775                 wake_up(&pipe_version_waitqueue);
 776         } else if (sn->pipe_version != new_version) {
 777                 /* Trying to open a pipe of a different version */
 778                 ret = -EBUSY;
 779                 goto out;
 780         }
 781         atomic_inc(&sn->pipe_users);
 782 out:
 783         spin_unlock(&pipe_version_lock);
 784         return ret;
 785
 786 }
 787
 788 static int gss_pipe_open_v0(struct inode *inode)
 789 {
 790         return gss_pipe_open(inode, 0);
 791 }
 792
 793 static int gss_pipe_open_v1(struct inode *inode)
 794 {
 795         return gss_pipe_open(inode, 1);
 796 }
 797
 798 static void
 799 gss_pipe_release(struct inode *inode)
 800 {
 801         struct net *net = inode->i_sb->s_fs_info;
 802         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 803         struct gss_upcall_msg *gss_msg;
 804
 805 restart:
 806         spin_lock(&pipe->lock);
 807         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
 808
 809                 if (!list_empty(&gss_msg->msg.list))
 810                         continue;
 811                 gss_msg->msg.errno = -EPIPE;
 812                 atomic_inc(&gss_msg->count);
 813                 __gss_unhash_msg(gss_msg);
 814                 spin_unlock(&pipe->lock);
 815                 gss_release_msg(gss_msg);
 816                 goto restart;
 817         }
 818         spin_unlock(&pipe->lock);
 819
 820         put_pipe_version(net);
 821 }
 822
 823 static void
 824 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 825 {
 826         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 827
 828         if (msg->errno < 0) {
 829                 dprintk("RPC:       %s releasing msg %p\n",
 830                         __func__, gss_msg);
 831                 atomic_inc(&gss_msg->count);
 832                 gss_unhash_msg(gss_msg);
 833                 if (msg->errno == -ETIMEDOUT)
 834                         warn_gssd();
 835                 gss_release_msg(gss_msg);
 836         }
 837 }
 838
 839 static void gss_pipe_dentry_destroy(struct dentry *dir,
 840                 struct rpc_pipe_dir_object *pdo)
 841 {
 842         struct gss_pipe *gss_pipe = pdo->pdo_data;
 843         struct rpc_pipe *pipe = gss_pipe->pipe;
 844
 845         if (pipe->dentry != NULL) {
 846                 rpc_unlink(pipe->dentry);
 847                 pipe->dentry = NULL;
 848         }
 849 }
 850
 851 static int gss_pipe_dentry_create(struct dentry *dir,
 852                 struct rpc_pipe_dir_object *pdo)
 853 {
 854         struct gss_pipe *p = pdo->pdo_data;
 855         struct dentry *dentry;
 856
 857         dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
 858         if (IS_ERR(dentry))
 859                 return PTR_ERR(dentry);
 860         p->pipe->dentry = dentry;
 861         return 0;
 862 }
 863
 864 static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
 865         .create = gss_pipe_dentry_create,
 866         .destroy = gss_pipe_dentry_destroy,
 867 };
 868
 869 static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
 870                 const char *name,
 871                 const struct rpc_pipe_ops *upcall_ops)
 872 {
 873         struct gss_pipe *p;
 874         int err = -ENOMEM;
 875
 876         p = kmalloc(sizeof(*p), GFP_KERNEL);
 877         if (p == NULL)
 878                 goto err;
 879         p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 880         if (IS_ERR(p->pipe)) {
 881                 err = PTR_ERR(p->pipe);
 882                 goto err_free_gss_pipe;
 883         }
 884         p->name = name;
 885         p->clnt = clnt;
 886         kref_init(&p->kref);
 887         rpc_init_pipe_dir_object(&p->pdo,
 888                         &gss_pipe_dir_object_ops,
 889                         p);
 890         return p;
 891 err_free_gss_pipe:
 892         kfree(p);
 893 err:
 894         return ERR_PTR(err);
 895 }
 896
 897 struct gss_alloc_pdo {
 898         struct rpc_clnt *clnt;
 899         const char *name;
 900         const struct rpc_pipe_ops *upcall_ops;
 901 };
 902
 903 static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
 904 {
 905         struct gss_pipe *gss_pipe;
 906         struct gss_alloc_pdo *args = data;
 907
 908         if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
 909                 return 0;
 910         gss_pipe = container_of(pdo, struct gss_pipe, pdo);
 911         if (strcmp(gss_pipe->name, args->name) != 0)
 912                 return 0;
 913         if (!kref_get_unless_zero(&gss_pipe->kref))
 914                 return 0;
 915         return 1;
 916 }
 917
 918 static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
 919 {
 920         struct gss_pipe *gss_pipe;
 921         struct gss_alloc_pdo *args = data;
 922
 923         gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
 924         if (!IS_ERR(gss_pipe))
 925                 return &gss_pipe->pdo;
 926         return NULL;
 927 }
 928
 929 static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
 930                 const char *name,
 931                 const struct rpc_pipe_ops *upcall_ops)
 932 {
 933         struct net *net = rpc_net_ns(clnt);
 934         struct rpc_pipe_dir_object *pdo;
 935         struct gss_alloc_pdo args = {
 936                 .clnt = clnt,
 937                 .name = name,
 938                 .upcall_ops = upcall_ops,
 939         };
 940
 941         pdo = rpc_find_or_alloc_pipe_dir_object(net,
 942                         &clnt->cl_pipedir_objects,
 943                         gss_pipe_match_pdo,
 944                         gss_pipe_alloc_pdo,
 945                         &args);
 946         if (pdo != NULL)
 947                 return container_of(pdo, struct gss_pipe, pdo);
 948         return ERR_PTR(-ENOMEM);
 949 }
 950
 951 static void __gss_pipe_free(struct gss_pipe *p)
 952 {
 953         struct rpc_clnt *clnt = p->clnt;
 954         struct net *net = rpc_net_ns(clnt);
 955
 956         rpc_remove_pipe_dir_object(net,
 957                         &clnt->cl_pipedir_objects,
 958                         &p->pdo);
 959         rpc_destroy_pipe_data(p->pipe);
 960         kfree(p);
 961 }
 962
 963 static void __gss_pipe_release(struct kref *kref)
 964 {
 965         struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
 966
 967         __gss_pipe_free(p);
 968 }
 969
 970 static void gss_pipe_free(struct gss_pipe *p)
 971 {
 972         if (p != NULL)
 973                 kref_put(&p->kref, __gss_pipe_release);
 974 }
 975
 976 /*
 977  * NOTE: we have the opportunity to use different
 978  * parameters based on the input flavor (which must be a pseudoflavor)
 979  */
 980 static struct gss_auth *
 981 gss_create_new(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
 982 {
 983         rpc_authflavor_t flavor = args->pseudoflavor;
 984         struct gss_auth *gss_auth;
 985         struct gss_pipe *gss_pipe;
 986         struct rpc_auth * auth;
 987         int err = -ENOMEM; /* XXX? */
 988
 989         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 990
 991         if (!try_module_get(THIS_MODULE))
 992                 return ERR_PTR(err);
 993         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 994                 goto out_dec;
 995         INIT_HLIST_NODE(&gss_auth->hash);
 996         gss_auth->target_name = NULL;
 997         if (args->target_name) {
 998                 gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
 999                 if (gss_auth->target_name == NULL)
1000                         goto err_free;
1001         }
1002         gss_auth->client = clnt;
1003         gss_auth->net = get_net(rpc_net_ns(clnt));
1004         err = -EINVAL;
1005         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
1006         if (!gss_auth->mech) {
1007                 dprintk("RPC:       Pseudoflavor %d not found!\n", flavor);
1008                 goto err_put_net;
1009         }
1010         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
1011         if (gss_auth->service == 0)
1012                 goto err_put_mech;
1013         if (!gssd_running(gss_auth->net))
1014                 goto err_put_mech;
1015         auth = &gss_auth->rpc_auth;
1016         auth->au_cslack = GSS_CRED_SLACK >> 2;
1017         auth->au_rslack = GSS_VERF_SLACK >> 2;
1018         auth->au_flags = 0;
1019         auth->au_ops = &authgss_ops;
1020         auth->au_flavor = flavor;
1021         if (gss_pseudoflavor_to_datatouch(gss_auth->mech, flavor))
1022                 auth->au_flags |= RPCAUTH_AUTH_DATATOUCH;
1023         atomic_set(&auth->au_count, 1);
1024         kref_init(&gss_auth->kref);
1025
1026         err = rpcauth_init_credcache(auth);
1027         if (err)
1028                 goto err_put_mech;
1029         /*
1030          * Note: if we created the old pipe first, then someone who
1031          * examined the directory at the right moment might conclude
1032          * that we supported only the old pipe.  So we instead create
1033          * the new pipe first.
1034          */
1035         gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
1036         if (IS_ERR(gss_pipe)) {
1037                 err = PTR_ERR(gss_pipe);
1038                 goto err_destroy_credcache;
1039         }
1040         gss_auth->gss_pipe[1] = gss_pipe;
1041
1042         gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
1043                         &gss_upcall_ops_v0);
1044         if (IS_ERR(gss_pipe)) {
1045                 err = PTR_ERR(gss_pipe);
1046                 goto err_destroy_pipe_1;
1047         }
1048         gss_auth->gss_pipe[0] = gss_pipe;
1049
1050         return gss_auth;
1051 err_destroy_pipe_1:
1052         gss_pipe_free(gss_auth->gss_pipe[1]);
1053 err_destroy_credcache:
1054         rpcauth_destroy_credcache(auth);
1055 err_put_mech:
1056         gss_mech_put(gss_auth->mech);
1057 err_put_net:
1058         put_net(gss_auth->net);
1059 err_free:
1060         kfree(gss_auth->target_name);
1061         kfree(gss_auth);
1062 out_dec:
1063         module_put(THIS_MODULE);
1064         return ERR_PTR(err);
1065 }
1066
1067 static void
1068 gss_free(struct gss_auth *gss_auth)
1069 {
1070         gss_pipe_free(gss_auth->gss_pipe[0]);
1071         gss_pipe_free(gss_auth->gss_pipe[1]);
1072         gss_mech_put(gss_auth->mech);
1073         put_net(gss_auth->net);
1074         kfree(gss_auth->target_name);
1075
1076         kfree(gss_auth);
1077         module_put(THIS_MODULE);
1078 }
1079
1080 static void
1081 gss_free_callback(struct kref *kref)
1082 {
1083         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1084
1085         gss_free(gss_auth);
1086 }
1087
1088 static void
1089 gss_put_auth(struct gss_auth *gss_auth)
1090 {
1091         kref_put(&gss_auth->kref, gss_free_callback);
1092 }
1093
1094 static void
1095 gss_destroy(struct rpc_auth *auth)
1096 {
1097         struct gss_auth *gss_auth = container_of(auth,
1098                         struct gss_auth, rpc_auth);
1099
1100         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
1101                         auth, auth->au_flavor);
1102
1103         if (hash_hashed(&gss_auth->hash)) {
1104                 spin_lock(&gss_auth_hash_lock);
1105                 hash_del(&gss_auth->hash);
1106                 spin_unlock(&gss_auth_hash_lock);
1107         }
1108
1109         gss_pipe_free(gss_auth->gss_pipe[0]);
1110         gss_auth->gss_pipe[0] = NULL;
1111         gss_pipe_free(gss_auth->gss_pipe[1]);
1112         gss_auth->gss_pipe[1] = NULL;
1113         rpcauth_destroy_credcache(auth);
1114
1115         gss_put_auth(gss_auth);
1116 }
1117
1118 /*
1119  * Auths may be shared between rpc clients that were cloned from a
1120  * common client with the same xprt, if they also share the flavor and
1121  * target_name.
1122  *
1123  * The auth is looked up from the oldest parent sharing the same
1124  * cl_xprt, and the auth itself references only that common parent
1125  * (which is guaranteed to last as long as any of its descendants).
1126  */
1127 static struct gss_auth *
1128 gss_auth_find_or_add_hashed(struct rpc_auth_create_args *args,
1129                 struct rpc_clnt *clnt,
1130                 struct gss_auth *new)
1131 {
1132         struct gss_auth *gss_auth;
1133         unsigned long hashval = (unsigned long)clnt;
1134
1135         spin_lock(&gss_auth_hash_lock);
1136         hash_for_each_possible(gss_auth_hash_table,
1137                         gss_auth,
1138                         hash,
1139                         hashval) {
1140                 if (gss_auth->client != clnt)
1141                         continue;
1142                 if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1143                         continue;
1144                 if (gss_auth->target_name != args->target_name) {
1145                         if (gss_auth->target_name == NULL)
1146                                 continue;
1147                         if (args->target_name == NULL)
1148                                 continue;
1149                         if (strcmp(gss_auth->target_name, args->target_name))
1150                                 continue;
1151                 }
1152                 if (!atomic_inc_not_zero(&gss_auth->rpc_auth.au_count))
1153                         continue;
1154                 goto out;
1155         }
1156         if (new)
1157                 hash_add(gss_auth_hash_table, &new->hash, hashval);
1158         gss_auth = new;
1159 out:
1160         spin_unlock(&gss_auth_hash_lock);
1161         return gss_auth;
1162 }
1163
1164 static struct gss_auth *
1165 gss_create_hashed(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1166 {
1167         struct gss_auth *gss_auth;
1168         struct gss_auth *new;
1169
1170         gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1171         if (gss_auth != NULL)
1172                 goto out;
1173         new = gss_create_new(args, clnt);
1174         if (IS_ERR(new))
1175                 return new;
1176         gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1177         if (gss_auth != new)
1178                 gss_destroy(&new->rpc_auth);
1179 out:
1180         return gss_auth;
1181 }
1182
1183 static struct rpc_auth *
1184 gss_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1185 {
1186         struct gss_auth *gss_auth;
1187         struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
1188
1189         while (clnt != clnt->cl_parent) {
1190                 struct rpc_clnt *parent = clnt->cl_parent;
1191                 /* Find the original parent for this transport */
1192                 if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
1193                         break;
1194                 clnt = parent;
1195         }
1196
1197         gss_auth = gss_create_hashed(args, clnt);
1198         if (IS_ERR(gss_auth))
1199                 return ERR_CAST(gss_auth);
1200         return &gss_auth->rpc_auth;
1201 }
1202
1203 /*
1204  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
1205  * to the server with the GSS control procedure field set to
1206  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1207  * all RPCSEC_GSS state associated with that context.
1208  */
1209 static int
1210 gss_destroying_context(struct rpc_cred *cred)
1211 {
1212         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1213         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1214         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1215         struct rpc_task *task;
1216
1217         if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
1218                 return 0;
1219
1220         ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1221         cred->cr_ops = &gss_nullops;
1222
1223         /* Take a reference to ensure the cred will be destroyed either
1224          * by the RPC call or by the put_rpccred() below */
1225         get_rpccred(cred);
1226
1227         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
1228         if (!IS_ERR(task))
1229                 rpc_put_task(task);
1230
1231         put_rpccred(cred);
1232         return 1;
1233 }
1234
1235 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1236  * to create a new cred or context, so they check that things have been
1237  * allocated before freeing them. */
1238 static void
1239 gss_do_free_ctx(struct gss_cl_ctx *ctx)
1240 {
1241         dprintk("RPC:       %s\n", __func__);
1242
1243         gss_delete_sec_context(&ctx->gc_gss_ctx);
1244         kfree(ctx->gc_wire_ctx.data);
1245         kfree(ctx->gc_acceptor.data);
1246         kfree(ctx);
1247 }
1248
1249 static void
1250 gss_free_ctx_callback(struct rcu_head *head)
1251 {
1252         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1253         gss_do_free_ctx(ctx);
1254 }
1255
1256 static void
1257 gss_free_ctx(struct gss_cl_ctx *ctx)
1258 {
1259         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1260 }
1261
1262 static void
1263 gss_free_cred(struct gss_cred *gss_cred)
1264 {
1265         dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1266         kfree(gss_cred);
1267 }
1268
1269 static void
1270 gss_free_cred_callback(struct rcu_head *head)
1271 {
1272         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1273         gss_free_cred(gss_cred);
1274 }
1275
1276 static void
1277 gss_destroy_nullcred(struct rpc_cred *cred)
1278 {
1279         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1280         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1281         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1282
1283         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1284         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1285         if (ctx)
1286                 gss_put_ctx(ctx);
1287         gss_put_auth(gss_auth);
1288 }
1289
1290 static void
1291 gss_destroy_cred(struct rpc_cred *cred)
1292 {
1293
1294         if (gss_destroying_context(cred))
1295                 return;
1296         gss_destroy_nullcred(cred);
1297 }
1298
1299 /*
1300  * Lookup RPCSEC_GSS cred for the current process
1301  */
1302 static struct rpc_cred *
1303 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1304 {
1305         return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS);
1306 }
1307
1308 static struct rpc_cred *
1309 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp)
1310 {
1311         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1312         struct gss_cred *cred = NULL;
1313         int err = -ENOMEM;
1314
1315         dprintk("RPC:       %s for uid %d, flavor %d\n",
1316                 __func__, from_kuid(&init_user_ns, acred->uid),
1317                 auth->au_flavor);
1318
1319         if (!(cred = kzalloc(sizeof(*cred), gfp)))
1320                 goto out_err;
1321
1322         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1323         /*
1324          * Note: in order to force a call to call_refresh(), we deliberately
1325          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1326          */
1327         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1328         cred->gc_service = gss_auth->service;
1329         cred->gc_principal = NULL;
1330         if (acred->machine_cred)
1331                 cred->gc_principal = acred->principal;
1332         kref_get(&gss_auth->kref);
1333         return &cred->gc_base;
1334
1335 out_err:
1336         dprintk("RPC:       %s failed with error %d\n", __func__, err);
1337         return ERR_PTR(err);
1338 }
1339
1340 static int
1341 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1342 {
1343         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1344         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1345         int err;
1346
1347         do {
1348                 err = gss_create_upcall(gss_auth, gss_cred);
1349         } while (err == -EAGAIN);
1350         return err;
1351 }
1352
1353 static char *
1354 gss_stringify_acceptor(struct rpc_cred *cred)
1355 {
1356         char *string = NULL;
1357         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1358         struct gss_cl_ctx *ctx;
1359         unsigned int len;
1360         struct xdr_netobj *acceptor;
1361
1362         rcu_read_lock();
1363         ctx = rcu_dereference(gss_cred->gc_ctx);
1364         if (!ctx)
1365                 goto out;
1366
1367         len = ctx->gc_acceptor.len;
1368         rcu_read_unlock();
1369
1370         /* no point if there's no string */
1371         if (!len)
1372                 return NULL;
1373 realloc:
1374         string = kmalloc(len + 1, GFP_KERNEL);
1375         if (!string)
1376                 return NULL;
1377
1378         rcu_read_lock();
1379         ctx = rcu_dereference(gss_cred->gc_ctx);
1380
1381         /* did the ctx disappear or was it replaced by one with no acceptor? */
1382         if (!ctx || !ctx->gc_acceptor.len) {
1383                 kfree(string);
1384                 string = NULL;
1385                 goto out;
1386         }
1387
1388         acceptor = &ctx->gc_acceptor;
1389
1390         /*
1391          * Did we find a new acceptor that's longer than the original? Allocate
1392          * a longer buffer and try again.
1393          */
1394         if (len < acceptor->len) {
1395                 len = acceptor->len;
1396                 rcu_read_unlock();
1397                 kfree(string);
1398                 goto realloc;
1399         }
1400
1401         memcpy(string, acceptor->data, acceptor->len);
1402         string[acceptor->len] = '\0';
1403 out:
1404         rcu_read_unlock();
1405         return string;
1406 }
1407
1408 /*
1409  * Returns -EACCES if GSS context is NULL or will expire within the
1410  * timeout (miliseconds)
1411  */
1412 static int
1413 gss_key_timeout(struct rpc_cred *rc)
1414 {
1415         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1416         struct gss_cl_ctx *ctx;
1417         unsigned long timeout = jiffies + (gss_key_expire_timeo * HZ);
1418         int ret = 0;
1419
1420         rcu_read_lock();
1421         ctx = rcu_dereference(gss_cred->gc_ctx);
1422         if (!ctx || time_after(timeout, ctx->gc_expiry))
1423                 ret = -EACCES;
1424         rcu_read_unlock();
1425
1426         return ret;
1427 }
1428
1429 static int
1430 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1431 {
1432         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1433         struct gss_cl_ctx *ctx;
1434         int ret;
1435
1436         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1437                 goto out;
1438         /* Don't match with creds that have expired. */
1439         rcu_read_lock();
1440         ctx = rcu_dereference(gss_cred->gc_ctx);
1441         if (!ctx || time_after(jiffies, ctx->gc_expiry)) {
1442                 rcu_read_unlock();
1443                 return 0;
1444         }
1445         rcu_read_unlock();
1446         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1447                 return 0;
1448 out:
1449         if (acred->principal != NULL) {
1450                 if (gss_cred->gc_principal == NULL)
1451                         return 0;
1452                 ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1453                 goto check_expire;
1454         }
1455         if (gss_cred->gc_principal != NULL)
1456                 return 0;
1457         ret = uid_eq(rc->cr_uid, acred->uid);
1458
1459 check_expire:
1460         if (ret == 0)
1461                 return ret;
1462
1463         /* Notify acred users of GSS context expiration timeout */
1464         if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags) &&
1465             (gss_key_timeout(rc) != 0)) {
1466                 /* test will now be done from generic cred */
1467                 test_and_clear_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
1468                 /* tell NFS layer that key will expire soon */
1469                 set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
1470         }
1471         return ret;
1472 }
1473
1474 /*
1475 * Marshal credentials.
1476 * Maybe we should keep a cached credential for performance reasons.
1477 */
1478 static __be32 *
1479 gss_marshal(struct rpc_task *task, __be32 *p)
1480 {
1481         struct rpc_rqst *req = task->tk_rqstp;
1482         struct rpc_cred *cred = req->rq_cred;
1483         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1484                                                  gc_base);
1485         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1486         __be32          *cred_len;
1487         u32             maj_stat = 0;
1488         struct xdr_netobj mic;
1489         struct kvec     iov;
1490         struct xdr_buf  verf_buf;
1491
1492         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1493
1494         *p++ = htonl(RPC_AUTH_GSS);
1495         cred_len = p++;
1496
1497         spin_lock(&ctx->gc_seq_lock);
1498         req->rq_seqno = ctx->gc_seq++;
1499         spin_unlock(&ctx->gc_seq_lock);
1500
1501         *p++ = htonl((u32) RPC_GSS_VERSION);
1502         *p++ = htonl((u32) ctx->gc_proc);
1503         *p++ = htonl((u32) req->rq_seqno);
1504         *p++ = htonl((u32) gss_cred->gc_service);
1505         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1506         *cred_len = htonl((p - (cred_len + 1)) << 2);
1507
1508         /* We compute the checksum for the verifier over the xdr-encoded bytes
1509          * starting with the xid and ending at the end of the credential: */
1510         iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
1511                                         req->rq_snd_buf.head[0].iov_base);
1512         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1513         xdr_buf_from_iov(&iov, &verf_buf);
1514
1515         /* set verifier flavor*/
1516         *p++ = htonl(RPC_AUTH_GSS);
1517
1518         mic.data = (u8 *)(p + 1);
1519         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1520         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1521                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1522         } else if (maj_stat != 0) {
1523                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1524                 goto out_put_ctx;
1525         }
1526         p = xdr_encode_opaque(p, NULL, mic.len);
1527         gss_put_ctx(ctx);
1528         return p;
1529 out_put_ctx:
1530         gss_put_ctx(ctx);
1531         return NULL;
1532 }
1533
1534 static int gss_renew_cred(struct rpc_task *task)
1535 {
1536         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1537         struct gss_cred *gss_cred = container_of(oldcred,
1538                                                  struct gss_cred,
1539                                                  gc_base);
1540         struct rpc_auth *auth = oldcred->cr_auth;
1541         struct auth_cred acred = {
1542                 .uid = oldcred->cr_uid,
1543                 .principal = gss_cred->gc_principal,
1544                 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
1545         };
1546         struct rpc_cred *new;
1547
1548         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1549         if (IS_ERR(new))
1550                 return PTR_ERR(new);
1551         task->tk_rqstp->rq_cred = new;
1552         put_rpccred(oldcred);
1553         return 0;
1554 }
1555
1556 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1557 {
1558         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1559                 unsigned long now = jiffies;
1560                 unsigned long begin, expire;
1561                 struct gss_cred *gss_cred;
1562
1563                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1564                 begin = gss_cred->gc_upcall_timestamp;
1565                 expire = begin + gss_expired_cred_retry_delay * HZ;
1566
1567                 if (time_in_range_open(now, begin, expire))
1568                         return 1;
1569         }
1570         return 0;
1571 }
1572
1573 /*
1574 * Refresh credentials. XXX - finish
1575 */
1576 static int
1577 gss_refresh(struct rpc_task *task)
1578 {
1579         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1580         int ret = 0;
1581
1582         if (gss_cred_is_negative_entry(cred))
1583                 return -EKEYEXPIRED;
1584
1585         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1586                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1587                 ret = gss_renew_cred(task);
1588                 if (ret < 0)
1589                         goto out;
1590                 cred = task->tk_rqstp->rq_cred;
1591         }
1592
1593         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1594                 ret = gss_refresh_upcall(task);
1595 out:
1596         return ret;
1597 }
1598
1599 /* Dummy refresh routine: used only when destroying the context */
1600 static int
1601 gss_refresh_null(struct rpc_task *task)
1602 {
1603         return 0;
1604 }
1605
1606 static __be32 *
1607 gss_validate(struct rpc_task *task, __be32 *p)
1608 {
1609         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1610         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1611         __be32          seq;
1612         struct kvec     iov;
1613         struct xdr_buf  verf_buf;
1614         struct xdr_netobj mic;
1615         u32             flav,len;
1616         u32             maj_stat;
1617         __be32          *ret = ERR_PTR(-EIO);
1618
1619         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1620
1621         flav = ntohl(*p++);
1622         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1623                 goto out_bad;
1624         if (flav != RPC_AUTH_GSS)
1625                 goto out_bad;
1626         seq = htonl(task->tk_rqstp->rq_seqno);
1627         iov.iov_base = &seq;
1628         iov.iov_len = sizeof(seq);
1629         xdr_buf_from_iov(&iov, &verf_buf);
1630         mic.data = (u8 *)p;
1631         mic.len = len;
1632
1633         ret = ERR_PTR(-EACCES);
1634         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1635         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1636                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1637         if (maj_stat) {
1638                 dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1639                         task->tk_pid, __func__, maj_stat);
1640                 goto out_bad;
1641         }
1642         /* We leave it to unwrap to calculate au_rslack. For now we just
1643          * calculate the length of the verifier: */
1644         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1645         gss_put_ctx(ctx);
1646         dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1647                         task->tk_pid, __func__);
1648         return p + XDR_QUADLEN(len);
1649 out_bad:
1650         gss_put_ctx(ctx);
1651         dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
1652                 PTR_ERR(ret));
1653         return ret;
1654 }
1655
1656 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1657                                 __be32 *p, void *obj)
1658 {
1659         struct xdr_stream xdr;
1660
1661         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1662         encode(rqstp, &xdr, obj);
1663 }
1664
1665 static inline int
1666 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1667                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1668                    __be32 *p, void *obj)
1669 {
1670         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1671         struct xdr_buf  integ_buf;
1672         __be32          *integ_len = NULL;
1673         struct xdr_netobj mic;
1674         u32             offset;
1675         __be32          *q;
1676         struct kvec     *iov;
1677         u32             maj_stat = 0;
1678         int             status = -EIO;
1679
1680         integ_len = p++;
1681         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1682         *p++ = htonl(rqstp->rq_seqno);
1683
1684         gss_wrap_req_encode(encode, rqstp, p, obj);
1685
1686         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1687                                 offset, snd_buf->len - offset))
1688                 return status;
1689         *integ_len = htonl(integ_buf.len);
1690
1691         /* guess whether we're in the head or the tail: */
1692         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1693                 iov = snd_buf->tail;
1694         else
1695                 iov = snd_buf->head;
1696         p = iov->iov_base + iov->iov_len;
1697         mic.data = (u8 *)(p + 1);
1698
1699         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1700         status = -EIO; /* XXX? */
1701         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1702                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1703         else if (maj_stat)
1704                 return status;
1705         q = xdr_encode_opaque(p, NULL, mic.len);
1706
1707         offset = (u8 *)q - (u8 *)p;
1708         iov->iov_len += offset;
1709         snd_buf->len += offset;
1710         return 0;
1711 }
1712
1713 static void
1714 priv_release_snd_buf(struct rpc_rqst *rqstp)
1715 {
1716         int i;
1717
1718         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1719                 __free_page(rqstp->rq_enc_pages[i]);
1720         kfree(rqstp->rq_enc_pages);
1721 }
1722
1723 static int
1724 alloc_enc_pages(struct rpc_rqst *rqstp)
1725 {
1726         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1727         int first, last, i;
1728
1729         if (snd_buf->page_len == 0) {
1730                 rqstp->rq_enc_pages_num = 0;
1731                 return 0;
1732         }
1733
1734         first = snd_buf->page_base >> PAGE_SHIFT;
1735         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_SHIFT;
1736         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1737         rqstp->rq_enc_pages
1738                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1739                                 GFP_NOFS);
1740         if (!rqstp->rq_enc_pages)
1741                 goto out;
1742         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1743                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1744                 if (rqstp->rq_enc_pages[i] == NULL)
1745                         goto out_free;
1746         }
1747         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1748         return 0;
1749 out_free:
1750         rqstp->rq_enc_pages_num = i;
1751         priv_release_snd_buf(rqstp);
1752 out:
1753         return -EAGAIN;
1754 }
1755
1756 static inline int
1757 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1758                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1759                   __be32 *p, void *obj)
1760 {
1761         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1762         u32             offset;
1763         u32             maj_stat;
1764         int             status;
1765         __be32          *opaque_len;
1766         struct page     **inpages;
1767         int             first;
1768         int             pad;
1769         struct kvec     *iov;
1770         char            *tmp;
1771
1772         opaque_len = p++;
1773         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1774         *p++ = htonl(rqstp->rq_seqno);
1775
1776         gss_wrap_req_encode(encode, rqstp, p, obj);
1777
1778         status = alloc_enc_pages(rqstp);
1779         if (status)
1780                 return status;
1781         first = snd_buf->page_base >> PAGE_SHIFT;
1782         inpages = snd_buf->pages + first;
1783         snd_buf->pages = rqstp->rq_enc_pages;
1784         snd_buf->page_base -= first << PAGE_SHIFT;
1785         /*
1786          * Give the tail its own page, in case we need extra space in the
1787          * head when wrapping:
1788          *
1789          * call_allocate() allocates twice the slack space required
1790          * by the authentication flavor to rq_callsize.
1791          * For GSS, slack is GSS_CRED_SLACK.
1792          */
1793         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1794                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1795                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1796                 snd_buf->tail[0].iov_base = tmp;
1797         }
1798         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1799         /* slack space should prevent this ever happening: */
1800         BUG_ON(snd_buf->len > snd_buf->buflen);
1801         status = -EIO;
1802         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1803          * done anyway, so it's safe to put the request on the wire: */
1804         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1805                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1806         else if (maj_stat)
1807                 return status;
1808
1809         *opaque_len = htonl(snd_buf->len - offset);
1810         /* guess whether we're in the head or the tail: */
1811         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1812                 iov = snd_buf->tail;
1813         else
1814                 iov = snd_buf->head;
1815         p = iov->iov_base + iov->iov_len;
1816         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1817         memset(p, 0, pad);
1818         iov->iov_len += pad;
1819         snd_buf->len += pad;
1820
1821         return 0;
1822 }
1823
1824 static int
1825 gss_wrap_req(struct rpc_task *task,
1826              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1827 {
1828         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1829         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1830                         gc_base);
1831         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1832         int             status = -EIO;
1833
1834         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1835         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1836                 /* The spec seems a little ambiguous here, but I think that not
1837                  * wrapping context destruction requests makes the most sense.
1838                  */
1839                 gss_wrap_req_encode(encode, rqstp, p, obj);
1840                 status = 0;
1841                 goto out;
1842         }
1843         switch (gss_cred->gc_service) {
1844         case RPC_GSS_SVC_NONE:
1845                 gss_wrap_req_encode(encode, rqstp, p, obj);
1846                 status = 0;
1847                 break;
1848         case RPC_GSS_SVC_INTEGRITY:
1849                 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1850                 break;
1851         case RPC_GSS_SVC_PRIVACY:
1852                 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1853                 break;
1854         }
1855 out:
1856         gss_put_ctx(ctx);
1857         dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1858         return status;
1859 }
1860
1861 static inline int
1862 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1863                 struct rpc_rqst *rqstp, __be32 **p)
1864 {
1865         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1866         struct xdr_buf integ_buf;
1867         struct xdr_netobj mic;
1868         u32 data_offset, mic_offset;
1869         u32 integ_len;
1870         u32 maj_stat;
1871         int status = -EIO;
1872
1873         integ_len = ntohl(*(*p)++);
1874         if (integ_len & 3)
1875                 return status;
1876         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1877         mic_offset = integ_len + data_offset;
1878         if (mic_offset > rcv_buf->len)
1879                 return status;
1880         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1881                 return status;
1882
1883         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1884                                 mic_offset - data_offset))
1885                 return status;
1886
1887         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1888                 return status;
1889
1890         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1891         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1892                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1893         if (maj_stat != GSS_S_COMPLETE)
1894                 return status;
1895         return 0;
1896 }
1897
1898 static inline int
1899 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1900                 struct rpc_rqst *rqstp, __be32 **p)
1901 {
1902         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1903         u32 offset;
1904         u32 opaque_len;
1905         u32 maj_stat;
1906         int status = -EIO;
1907
1908         opaque_len = ntohl(*(*p)++);
1909         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1910         if (offset + opaque_len > rcv_buf->len)
1911                 return status;
1912         /* remove padding: */
1913         rcv_buf->len = offset + opaque_len;
1914
1915         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1916         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1917                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1918         if (maj_stat != GSS_S_COMPLETE)
1919                 return status;
1920         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1921                 return status;
1922
1923         return 0;
1924 }
1925
1926 static int
1927 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1928                       __be32 *p, void *obj)
1929 {
1930         struct xdr_stream xdr;
1931
1932         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1933         return decode(rqstp, &xdr, obj);
1934 }
1935
1936 static int
1937 gss_unwrap_resp(struct rpc_task *task,
1938                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1939 {
1940         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1941         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1942                         gc_base);
1943         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1944         __be32          *savedp = p;
1945         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1946         int             savedlen = head->iov_len;
1947         int             status = -EIO;
1948
1949         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1950                 goto out_decode;
1951         switch (gss_cred->gc_service) {
1952         case RPC_GSS_SVC_NONE:
1953                 break;
1954         case RPC_GSS_SVC_INTEGRITY:
1955                 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1956                 if (status)
1957                         goto out;
1958                 break;
1959         case RPC_GSS_SVC_PRIVACY:
1960                 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1961                 if (status)
1962                         goto out;
1963                 break;
1964         }
1965         /* take into account extra slack for integrity and privacy cases: */
1966         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1967                                                 + (savedlen - head->iov_len);
1968 out_decode:
1969         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
1970 out:
1971         gss_put_ctx(ctx);
1972         dprintk("RPC: %5u %s returning %d\n",
1973                 task->tk_pid, __func__, status);
1974         return status;
1975 }
1976
1977 static const struct rpc_authops authgss_ops = {
1978         .owner          = THIS_MODULE,
1979         .au_flavor      = RPC_AUTH_GSS,
1980         .au_name        = "RPCSEC_GSS",
1981         .create         = gss_create,
1982         .destroy        = gss_destroy,
1983         .lookup_cred    = gss_lookup_cred,
1984         .crcreate       = gss_create_cred,
1985         .list_pseudoflavors = gss_mech_list_pseudoflavors,
1986         .info2flavor    = gss_mech_info2flavor,
1987         .flavor2info    = gss_mech_flavor2info,
1988 };
1989
1990 static const struct rpc_credops gss_credops = {
1991         .cr_name                = "AUTH_GSS",
1992         .crdestroy              = gss_destroy_cred,
1993         .cr_init                = gss_cred_init,
1994         .crbind                 = rpcauth_generic_bind_cred,
1995         .crmatch                = gss_match,
1996         .crmarshal              = gss_marshal,
1997         .crrefresh              = gss_refresh,
1998         .crvalidate             = gss_validate,
1999         .crwrap_req             = gss_wrap_req,
2000         .crunwrap_resp          = gss_unwrap_resp,
2001         .crkey_timeout          = gss_key_timeout,
2002         .crstringify_acceptor   = gss_stringify_acceptor,
2003 };
2004
2005 static const struct rpc_credops gss_nullops = {
2006         .cr_name                = "AUTH_GSS",
2007         .crdestroy              = gss_destroy_nullcred,
2008         .crbind                 = rpcauth_generic_bind_cred,
2009         .crmatch                = gss_match,
2010         .crmarshal              = gss_marshal,
2011         .crrefresh              = gss_refresh_null,
2012         .crvalidate             = gss_validate,
2013         .crwrap_req             = gss_wrap_req,
2014         .crunwrap_resp          = gss_unwrap_resp,
2015         .crstringify_acceptor   = gss_stringify_acceptor,
2016 };
2017
2018 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
2019         .upcall         = rpc_pipe_generic_upcall,
2020         .downcall       = gss_pipe_downcall,
2021         .destroy_msg    = gss_pipe_destroy_msg,
2022         .open_pipe      = gss_pipe_open_v0,
2023         .release_pipe   = gss_pipe_release,
2024 };
2025
2026 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
2027         .upcall         = rpc_pipe_generic_upcall,
2028         .downcall       = gss_pipe_downcall,
2029         .destroy_msg    = gss_pipe_destroy_msg,
2030         .open_pipe      = gss_pipe_open_v1,
2031         .release_pipe   = gss_pipe_release,
2032 };
2033
2034 static __net_init int rpcsec_gss_init_net(struct net *net)
2035 {
2036         return gss_svc_init_net(net);
2037 }
2038
2039 static __net_exit void rpcsec_gss_exit_net(struct net *net)
2040 {
2041         gss_svc_shutdown_net(net);
2042 }
2043
2044 static struct pernet_operations rpcsec_gss_net_ops = {
2045         .init = rpcsec_gss_init_net,
2046         .exit = rpcsec_gss_exit_net,
2047 };
2048
2049 /*
2050  * Initialize RPCSEC_GSS module
2051  */
2052 static int __init init_rpcsec_gss(void)
2053 {
2054         int err = 0;
2055
2056         err = rpcauth_register(&authgss_ops);
2057         if (err)
2058                 goto out;
2059         err = gss_svc_init();
2060         if (err)
2061                 goto out_unregister;
2062         err = register_pernet_subsys(&rpcsec_gss_net_ops);
2063         if (err)
2064                 goto out_svc_exit;
2065         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
2066         return 0;
2067 out_svc_exit:
2068         gss_svc_shutdown();
2069 out_unregister:
2070         rpcauth_unregister(&authgss_ops);
2071 out:
2072         return err;
2073 }
2074
2075 static void __exit exit_rpcsec_gss(void)
2076 {
2077         unregister_pernet_subsys(&rpcsec_gss_net_ops);
2078         gss_svc_shutdown();
2079         rpcauth_unregister(&authgss_ops);
2080         rcu_barrier(); /* Wait for completion of call_rcu()'s */
2081 }
2082
2083 MODULE_ALIAS("rpc-auth-6");
2084 MODULE_LICENSE("GPL");
2085 module_param_named(expired_cred_retry_delay,
2086                    gss_expired_cred_retry_delay,
2087                    uint, 0644);
2088 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
2089                 "the RPC engine retries an expired credential");
2090
2091 module_param_named(key_expire_timeo,
2092                    gss_key_expire_timeo,
2093                    uint, 0644);
2094 MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
2095                 "credential keys lifetime where the NFS layer cleans up "
2096                 "prior to key expiration");
2097
2098 module_init(init_rpcsec_gss)
2099 module_exit(exit_rpcsec_gss)