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, const struct gss_auth *auth)
 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                 if (auth && pos->auth->service != auth->service)
 350                         continue;
 351                 atomic_inc(&pos->count);
 352                 dprintk("RPC:       %s found msg %p\n", __func__, pos);
 353                 return pos;
 354         }
 355         dprintk("RPC:       %s found nothing\n", __func__);
 356         return NULL;
 357 }
 358
 359 /* Try to add an upcall to the pipefs queue.
 360  * If an upcall owned by our uid already exists, then we return a reference
 361  * to that upcall instead of adding the new upcall.
 362  */
 363 static inline struct gss_upcall_msg *
 364 gss_add_msg(struct gss_upcall_msg *gss_msg)
 365 {
 366         struct rpc_pipe *pipe = gss_msg->pipe;
 367         struct gss_upcall_msg *old;
 368
 369         spin_lock(&pipe->lock);
 370         old = __gss_find_upcall(pipe, gss_msg->uid, gss_msg->auth);
 371         if (old == NULL) {
 372                 atomic_inc(&gss_msg->count);
 373                 list_add(&gss_msg->list, &pipe->in_downcall);
 374         } else
 375                 gss_msg = old;
 376         spin_unlock(&pipe->lock);
 377         return gss_msg;
 378 }
 379
 380 static void
 381 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 382 {
 383         list_del_init(&gss_msg->list);
 384         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 385         wake_up_all(&gss_msg->waitqueue);
 386         atomic_dec(&gss_msg->count);
 387 }
 388
 389 static void
 390 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 391 {
 392         struct rpc_pipe *pipe = gss_msg->pipe;
 393
 394         if (list_empty(&gss_msg->list))
 395                 return;
 396         spin_lock(&pipe->lock);
 397         if (!list_empty(&gss_msg->list))
 398                 __gss_unhash_msg(gss_msg);
 399         spin_unlock(&pipe->lock);
 400 }
 401
 402 static void
 403 gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
 404 {
 405         switch (gss_msg->msg.errno) {
 406         case 0:
 407                 if (gss_msg->ctx == NULL)
 408                         break;
 409                 clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 410                 gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
 411                 break;
 412         case -EKEYEXPIRED:
 413                 set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 414         }
 415         gss_cred->gc_upcall_timestamp = jiffies;
 416         gss_cred->gc_upcall = NULL;
 417         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 418 }
 419
 420 static void
 421 gss_upcall_callback(struct rpc_task *task)
 422 {
 423         struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
 424                         struct gss_cred, gc_base);
 425         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 426         struct rpc_pipe *pipe = gss_msg->pipe;
 427
 428         spin_lock(&pipe->lock);
 429         gss_handle_downcall_result(gss_cred, gss_msg);
 430         spin_unlock(&pipe->lock);
 431         task->tk_status = gss_msg->msg.errno;
 432         gss_release_msg(gss_msg);
 433 }
 434
 435 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
 436 {
 437         uid_t uid = from_kuid(&init_user_ns, gss_msg->uid);
 438         memcpy(gss_msg->databuf, &uid, sizeof(uid));
 439         gss_msg->msg.data = gss_msg->databuf;
 440         gss_msg->msg.len = sizeof(uid);
 441
 442         BUILD_BUG_ON(sizeof(uid) > sizeof(gss_msg->databuf));
 443 }
 444
 445 static int gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
 446                                 const char *service_name,
 447                                 const char *target_name)
 448 {
 449         struct gss_api_mech *mech = gss_msg->auth->mech;
 450         char *p = gss_msg->databuf;
 451         size_t buflen = sizeof(gss_msg->databuf);
 452         int len;
 453
 454         len = scnprintf(p, buflen, "mech=%s uid=%d ", mech->gm_name,
 455                         from_kuid(&init_user_ns, gss_msg->uid));
 456         buflen -= len;
 457         p += len;
 458         gss_msg->msg.len = len;
 459         if (target_name) {
 460                 len = scnprintf(p, buflen, "target=%s ", target_name);
 461                 buflen -= len;
 462                 p += len;
 463                 gss_msg->msg.len += len;
 464         }
 465         if (service_name != NULL) {
 466                 len = scnprintf(p, buflen, "service=%s ", service_name);
 467                 buflen -= len;
 468                 p += len;
 469                 gss_msg->msg.len += len;
 470         }
 471         if (mech->gm_upcall_enctypes) {
 472                 len = scnprintf(p, buflen, "enctypes=%s ",
 473                                 mech->gm_upcall_enctypes);
 474                 buflen -= len;
 475                 p += len;
 476                 gss_msg->msg.len += len;
 477         }
 478         len = scnprintf(p, buflen, "\n");
 479         if (len == 0)
 480                 goto out_overflow;
 481         gss_msg->msg.len += len;
 482
 483         gss_msg->msg.data = gss_msg->databuf;
 484         return 0;
 485 out_overflow:
 486         WARN_ON_ONCE(1);
 487         return -ENOMEM;
 488 }
 489
 490 static struct gss_upcall_msg *
 491 gss_alloc_msg(struct gss_auth *gss_auth,
 492                 kuid_t uid, const char *service_name)
 493 {
 494         struct gss_upcall_msg *gss_msg;
 495         int vers;
 496         int err = -ENOMEM;
 497
 498         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 499         if (gss_msg == NULL)
 500                 goto err;
 501         vers = get_pipe_version(gss_auth->net);
 502         err = vers;
 503         if (err < 0)
 504                 goto err_free_msg;
 505         gss_msg->pipe = gss_auth->gss_pipe[vers]->pipe;
 506         INIT_LIST_HEAD(&gss_msg->list);
 507         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 508         init_waitqueue_head(&gss_msg->waitqueue);
 509         atomic_set(&gss_msg->count, 1);
 510         gss_msg->uid = uid;
 511         gss_msg->auth = gss_auth;
 512         switch (vers) {
 513         case 0:
 514                 gss_encode_v0_msg(gss_msg);
 515                 break;
 516         default:
 517                 err = gss_encode_v1_msg(gss_msg, service_name, gss_auth->target_name);
 518                 if (err)
 519                         goto err_put_pipe_version;
 520         };
 521         kref_get(&gss_auth->kref);
 522         return gss_msg;
 523 err_put_pipe_version:
 524         put_pipe_version(gss_auth->net);
 525 err_free_msg:
 526         kfree(gss_msg);
 527 err:
 528         return ERR_PTR(err);
 529 }
 530
 531 static struct gss_upcall_msg *
 532 gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred)
 533 {
 534         struct gss_cred *gss_cred = container_of(cred,
 535                         struct gss_cred, gc_base);
 536         struct gss_upcall_msg *gss_new, *gss_msg;
 537         kuid_t uid = cred->cr_uid;
 538
 539         gss_new = gss_alloc_msg(gss_auth, uid, gss_cred->gc_principal);
 540         if (IS_ERR(gss_new))
 541                 return gss_new;
 542         gss_msg = gss_add_msg(gss_new);
 543         if (gss_msg == gss_new) {
 544                 int res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
 545                 if (res) {
 546                         gss_unhash_msg(gss_new);
 547                         gss_msg = ERR_PTR(res);
 548                 }
 549         } else
 550                 gss_release_msg(gss_new);
 551         return gss_msg;
 552 }
 553
 554 static void warn_gssd(void)
 555 {
 556         dprintk("AUTH_GSS upcall failed. Please check user daemon is running.\n");
 557 }
 558
 559 static inline int
 560 gss_refresh_upcall(struct rpc_task *task)
 561 {
 562         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 563         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 564                         struct gss_auth, rpc_auth);
 565         struct gss_cred *gss_cred = container_of(cred,
 566                         struct gss_cred, gc_base);
 567         struct gss_upcall_msg *gss_msg;
 568         struct rpc_pipe *pipe;
 569         int err = 0;
 570
 571         dprintk("RPC: %5u %s for uid %u\n",
 572                 task->tk_pid, __func__, from_kuid(&init_user_ns, cred->cr_uid));
 573         gss_msg = gss_setup_upcall(gss_auth, cred);
 574         if (PTR_ERR(gss_msg) == -EAGAIN) {
 575                 /* XXX: warning on the first, under the assumption we
 576                  * shouldn't normally hit this case on a refresh. */
 577                 warn_gssd();
 578                 task->tk_timeout = 15*HZ;
 579                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
 580                 return -EAGAIN;
 581         }
 582         if (IS_ERR(gss_msg)) {
 583                 err = PTR_ERR(gss_msg);
 584                 goto out;
 585         }
 586         pipe = gss_msg->pipe;
 587         spin_lock(&pipe->lock);
 588         if (gss_cred->gc_upcall != NULL)
 589                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 590         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 591                 task->tk_timeout = 0;
 592                 gss_cred->gc_upcall = gss_msg;
 593                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 594                 atomic_inc(&gss_msg->count);
 595                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 596         } else {
 597                 gss_handle_downcall_result(gss_cred, gss_msg);
 598                 err = gss_msg->msg.errno;
 599         }
 600         spin_unlock(&pipe->lock);
 601         gss_release_msg(gss_msg);
 602 out:
 603         dprintk("RPC: %5u %s for uid %u result %d\n",
 604                 task->tk_pid, __func__,
 605                 from_kuid(&init_user_ns, cred->cr_uid), err);
 606         return err;
 607 }
 608
 609 static inline int
 610 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 611 {
 612         struct net *net = gss_auth->net;
 613         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 614         struct rpc_pipe *pipe;
 615         struct rpc_cred *cred = &gss_cred->gc_base;
 616         struct gss_upcall_msg *gss_msg;
 617         DEFINE_WAIT(wait);
 618         int err;
 619
 620         dprintk("RPC:       %s for uid %u\n",
 621                 __func__, from_kuid(&init_user_ns, cred->cr_uid));
 622 retry:
 623         err = 0;
 624         /* if gssd is down, just skip upcalling altogether */
 625         if (!gssd_running(net)) {
 626                 warn_gssd();
 627                 return -EACCES;
 628         }
 629         gss_msg = gss_setup_upcall(gss_auth, cred);
 630         if (PTR_ERR(gss_msg) == -EAGAIN) {
 631                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
 632                                 sn->pipe_version >= 0, 15 * HZ);
 633                 if (sn->pipe_version < 0) {
 634                         warn_gssd();
 635                         err = -EACCES;
 636                 }
 637                 if (err < 0)
 638                         goto out;
 639                 goto retry;
 640         }
 641         if (IS_ERR(gss_msg)) {
 642                 err = PTR_ERR(gss_msg);
 643                 goto out;
 644         }
 645         pipe = gss_msg->pipe;
 646         for (;;) {
 647                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
 648                 spin_lock(&pipe->lock);
 649                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 650                         break;
 651                 }
 652                 spin_unlock(&pipe->lock);
 653                 if (fatal_signal_pending(current)) {
 654                         err = -ERESTARTSYS;
 655                         goto out_intr;
 656                 }
 657                 schedule();
 658         }
 659         if (gss_msg->ctx)
 660                 gss_cred_set_ctx(cred, gss_msg->ctx);
 661         else
 662                 err = gss_msg->msg.errno;
 663         spin_unlock(&pipe->lock);
 664 out_intr:
 665         finish_wait(&gss_msg->waitqueue, &wait);
 666         gss_release_msg(gss_msg);
 667 out:
 668         dprintk("RPC:       %s for uid %u result %d\n",
 669                 __func__, from_kuid(&init_user_ns, cred->cr_uid), err);
 670         return err;
 671 }
 672
 673 #define MSG_BUF_MAXSIZE 1024
 674
 675 static ssize_t
 676 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 677 {
 678         const void *p, *end;
 679         void *buf;
 680         struct gss_upcall_msg *gss_msg;
 681         struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
 682         struct gss_cl_ctx *ctx;
 683         uid_t id;
 684         kuid_t uid;
 685         ssize_t err = -EFBIG;
 686
 687         if (mlen > MSG_BUF_MAXSIZE)
 688                 goto out;
 689         err = -ENOMEM;
 690         buf = kmalloc(mlen, GFP_NOFS);
 691         if (!buf)
 692                 goto out;
 693
 694         err = -EFAULT;
 695         if (copy_from_user(buf, src, mlen))
 696                 goto err;
 697
 698         end = (const void *)((char *)buf + mlen);
 699         p = simple_get_bytes(buf, end, &id, sizeof(id));
 700         if (IS_ERR(p)) {
 701                 err = PTR_ERR(p);
 702                 goto err;
 703         }
 704
 705         uid = make_kuid(&init_user_ns, id);
 706         if (!uid_valid(uid)) {
 707                 err = -EINVAL;
 708                 goto err;
 709         }
 710
 711         err = -ENOMEM;
 712         ctx = gss_alloc_context();
 713         if (ctx == NULL)
 714                 goto err;
 715
 716         err = -ENOENT;
 717         /* Find a matching upcall */
 718         spin_lock(&pipe->lock);
 719         gss_msg = __gss_find_upcall(pipe, uid, NULL);
 720         if (gss_msg == NULL) {
 721                 spin_unlock(&pipe->lock);
 722                 goto err_put_ctx;
 723         }
 724         list_del_init(&gss_msg->list);
 725         spin_unlock(&pipe->lock);
 726
 727         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 728         if (IS_ERR(p)) {
 729                 err = PTR_ERR(p);
 730                 switch (err) {
 731                 case -EACCES:
 732                 case -EKEYEXPIRED:
 733                         gss_msg->msg.errno = err;
 734                         err = mlen;
 735                         break;
 736                 case -EFAULT:
 737                 case -ENOMEM:
 738                 case -EINVAL:
 739                 case -ENOSYS:
 740                         gss_msg->msg.errno = -EAGAIN;
 741                         break;
 742                 default:
 743                         printk(KERN_CRIT "%s: bad return from "
 744                                 "gss_fill_context: %zd\n", __func__, err);
 745                         gss_msg->msg.errno = -EIO;
 746                 }
 747                 goto err_release_msg;
 748         }
 749         gss_msg->ctx = gss_get_ctx(ctx);
 750         err = mlen;
 751
 752 err_release_msg:
 753         spin_lock(&pipe->lock);
 754         __gss_unhash_msg(gss_msg);
 755         spin_unlock(&pipe->lock);
 756         gss_release_msg(gss_msg);
 757 err_put_ctx:
 758         gss_put_ctx(ctx);
 759 err:
 760         kfree(buf);
 761 out:
 762         dprintk("RPC:       %s returning %Zd\n", __func__, err);
 763         return err;
 764 }
 765
 766 static int gss_pipe_open(struct inode *inode, int new_version)
 767 {
 768         struct net *net = inode->i_sb->s_fs_info;
 769         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 770         int ret = 0;
 771
 772         spin_lock(&pipe_version_lock);
 773         if (sn->pipe_version < 0) {
 774                 /* First open of any gss pipe determines the version: */
 775                 sn->pipe_version = new_version;
 776                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 777                 wake_up(&pipe_version_waitqueue);
 778         } else if (sn->pipe_version != new_version) {
 779                 /* Trying to open a pipe of a different version */
 780                 ret = -EBUSY;
 781                 goto out;
 782         }
 783         atomic_inc(&sn->pipe_users);
 784 out:
 785         spin_unlock(&pipe_version_lock);
 786         return ret;
 787
 788 }
 789
 790 static int gss_pipe_open_v0(struct inode *inode)
 791 {
 792         return gss_pipe_open(inode, 0);
 793 }
 794
 795 static int gss_pipe_open_v1(struct inode *inode)
 796 {
 797         return gss_pipe_open(inode, 1);
 798 }
 799
 800 static void
 801 gss_pipe_release(struct inode *inode)
 802 {
 803         struct net *net = inode->i_sb->s_fs_info;
 804         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 805         struct gss_upcall_msg *gss_msg;
 806
 807 restart:
 808         spin_lock(&pipe->lock);
 809         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
 810
 811                 if (!list_empty(&gss_msg->msg.list))
 812                         continue;
 813                 gss_msg->msg.errno = -EPIPE;
 814                 atomic_inc(&gss_msg->count);
 815                 __gss_unhash_msg(gss_msg);
 816                 spin_unlock(&pipe->lock);
 817                 gss_release_msg(gss_msg);
 818                 goto restart;
 819         }
 820         spin_unlock(&pipe->lock);
 821
 822         put_pipe_version(net);
 823 }
 824
 825 static void
 826 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 827 {
 828         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 829
 830         if (msg->errno < 0) {
 831                 dprintk("RPC:       %s releasing msg %p\n",
 832                         __func__, gss_msg);
 833                 atomic_inc(&gss_msg->count);
 834                 gss_unhash_msg(gss_msg);
 835                 if (msg->errno == -ETIMEDOUT)
 836                         warn_gssd();
 837                 gss_release_msg(gss_msg);
 838         }
 839 }
 840
 841 static void gss_pipe_dentry_destroy(struct dentry *dir,
 842                 struct rpc_pipe_dir_object *pdo)
 843 {
 844         struct gss_pipe *gss_pipe = pdo->pdo_data;
 845         struct rpc_pipe *pipe = gss_pipe->pipe;
 846
 847         if (pipe->dentry != NULL) {
 848                 rpc_unlink(pipe->dentry);
 849                 pipe->dentry = NULL;
 850         }
 851 }
 852
 853 static int gss_pipe_dentry_create(struct dentry *dir,
 854                 struct rpc_pipe_dir_object *pdo)
 855 {
 856         struct gss_pipe *p = pdo->pdo_data;
 857         struct dentry *dentry;
 858
 859         dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
 860         if (IS_ERR(dentry))
 861                 return PTR_ERR(dentry);
 862         p->pipe->dentry = dentry;
 863         return 0;
 864 }
 865
 866 static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
 867         .create = gss_pipe_dentry_create,
 868         .destroy = gss_pipe_dentry_destroy,
 869 };
 870
 871 static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
 872                 const char *name,
 873                 const struct rpc_pipe_ops *upcall_ops)
 874 {
 875         struct gss_pipe *p;
 876         int err = -ENOMEM;
 877
 878         p = kmalloc(sizeof(*p), GFP_KERNEL);
 879         if (p == NULL)
 880                 goto err;
 881         p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 882         if (IS_ERR(p->pipe)) {
 883                 err = PTR_ERR(p->pipe);
 884                 goto err_free_gss_pipe;
 885         }
 886         p->name = name;
 887         p->clnt = clnt;
 888         kref_init(&p->kref);
 889         rpc_init_pipe_dir_object(&p->pdo,
 890                         &gss_pipe_dir_object_ops,
 891                         p);
 892         return p;
 893 err_free_gss_pipe:
 894         kfree(p);
 895 err:
 896         return ERR_PTR(err);
 897 }
 898
 899 struct gss_alloc_pdo {
 900         struct rpc_clnt *clnt;
 901         const char *name;
 902         const struct rpc_pipe_ops *upcall_ops;
 903 };
 904
 905 static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
 906 {
 907         struct gss_pipe *gss_pipe;
 908         struct gss_alloc_pdo *args = data;
 909
 910         if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
 911                 return 0;
 912         gss_pipe = container_of(pdo, struct gss_pipe, pdo);
 913         if (strcmp(gss_pipe->name, args->name) != 0)
 914                 return 0;
 915         if (!kref_get_unless_zero(&gss_pipe->kref))
 916                 return 0;
 917         return 1;
 918 }
 919
 920 static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
 921 {
 922         struct gss_pipe *gss_pipe;
 923         struct gss_alloc_pdo *args = data;
 924
 925         gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
 926         if (!IS_ERR(gss_pipe))
 927                 return &gss_pipe->pdo;
 928         return NULL;
 929 }
 930
 931 static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
 932                 const char *name,
 933                 const struct rpc_pipe_ops *upcall_ops)
 934 {
 935         struct net *net = rpc_net_ns(clnt);
 936         struct rpc_pipe_dir_object *pdo;
 937         struct gss_alloc_pdo args = {
 938                 .clnt = clnt,
 939                 .name = name,
 940                 .upcall_ops = upcall_ops,
 941         };
 942
 943         pdo = rpc_find_or_alloc_pipe_dir_object(net,
 944                         &clnt->cl_pipedir_objects,
 945                         gss_pipe_match_pdo,
 946                         gss_pipe_alloc_pdo,
 947                         &args);
 948         if (pdo != NULL)
 949                 return container_of(pdo, struct gss_pipe, pdo);
 950         return ERR_PTR(-ENOMEM);
 951 }
 952
 953 static void __gss_pipe_free(struct gss_pipe *p)
 954 {
 955         struct rpc_clnt *clnt = p->clnt;
 956         struct net *net = rpc_net_ns(clnt);
 957
 958         rpc_remove_pipe_dir_object(net,
 959                         &clnt->cl_pipedir_objects,
 960                         &p->pdo);
 961         rpc_destroy_pipe_data(p->pipe);
 962         kfree(p);
 963 }
 964
 965 static void __gss_pipe_release(struct kref *kref)
 966 {
 967         struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
 968
 969         __gss_pipe_free(p);
 970 }
 971
 972 static void gss_pipe_free(struct gss_pipe *p)
 973 {
 974         if (p != NULL)
 975                 kref_put(&p->kref, __gss_pipe_release);
 976 }
 977
 978 /*
 979  * NOTE: we have the opportunity to use different
 980  * parameters based on the input flavor (which must be a pseudoflavor)
 981  */
 982 static struct gss_auth *
 983 gss_create_new(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
 984 {
 985         rpc_authflavor_t flavor = args->pseudoflavor;
 986         struct gss_auth *gss_auth;
 987         struct gss_pipe *gss_pipe;
 988         struct rpc_auth * auth;
 989         int err = -ENOMEM; /* XXX? */
 990
 991         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 992
 993         if (!try_module_get(THIS_MODULE))
 994                 return ERR_PTR(err);
 995         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 996                 goto out_dec;
 997         INIT_HLIST_NODE(&gss_auth->hash);
 998         gss_auth->target_name = NULL;
 999         if (args->target_name) {
1000                 gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
1001                 if (gss_auth->target_name == NULL)
1002                         goto err_free;
1003         }
1004         gss_auth->client = clnt;
1005         gss_auth->net = get_net(rpc_net_ns(clnt));
1006         err = -EINVAL;
1007         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
1008         if (!gss_auth->mech) {
1009                 dprintk("RPC:       Pseudoflavor %d not found!\n", flavor);
1010                 goto err_put_net;
1011         }
1012         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
1013         if (gss_auth->service == 0)
1014                 goto err_put_mech;
1015         if (!gssd_running(gss_auth->net))
1016                 goto err_put_mech;
1017         auth = &gss_auth->rpc_auth;
1018         auth->au_cslack = GSS_CRED_SLACK >> 2;
1019         auth->au_rslack = GSS_VERF_SLACK >> 2;
1020         auth->au_flags = 0;
1021         auth->au_ops = &authgss_ops;
1022         auth->au_flavor = flavor;
1023         if (gss_pseudoflavor_to_datatouch(gss_auth->mech, flavor))
1024                 auth->au_flags |= RPCAUTH_AUTH_DATATOUCH;
1025         atomic_set(&auth->au_count, 1);
1026         kref_init(&gss_auth->kref);
1027
1028         err = rpcauth_init_credcache(auth);
1029         if (err)
1030                 goto err_put_mech;
1031         /*
1032          * Note: if we created the old pipe first, then someone who
1033          * examined the directory at the right moment might conclude
1034          * that we supported only the old pipe.  So we instead create
1035          * the new pipe first.
1036          */
1037         gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
1038         if (IS_ERR(gss_pipe)) {
1039                 err = PTR_ERR(gss_pipe);
1040                 goto err_destroy_credcache;
1041         }
1042         gss_auth->gss_pipe[1] = gss_pipe;
1043
1044         gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
1045                         &gss_upcall_ops_v0);
1046         if (IS_ERR(gss_pipe)) {
1047                 err = PTR_ERR(gss_pipe);
1048                 goto err_destroy_pipe_1;
1049         }
1050         gss_auth->gss_pipe[0] = gss_pipe;
1051
1052         return gss_auth;
1053 err_destroy_pipe_1:
1054         gss_pipe_free(gss_auth->gss_pipe[1]);
1055 err_destroy_credcache:
1056         rpcauth_destroy_credcache(auth);
1057 err_put_mech:
1058         gss_mech_put(gss_auth->mech);
1059 err_put_net:
1060         put_net(gss_auth->net);
1061 err_free:
1062         kfree(gss_auth->target_name);
1063         kfree(gss_auth);
1064 out_dec:
1065         module_put(THIS_MODULE);
1066         return ERR_PTR(err);
1067 }
1068
1069 static void
1070 gss_free(struct gss_auth *gss_auth)
1071 {
1072         gss_pipe_free(gss_auth->gss_pipe[0]);
1073         gss_pipe_free(gss_auth->gss_pipe[1]);
1074         gss_mech_put(gss_auth->mech);
1075         put_net(gss_auth->net);
1076         kfree(gss_auth->target_name);
1077
1078         kfree(gss_auth);
1079         module_put(THIS_MODULE);
1080 }
1081
1082 static void
1083 gss_free_callback(struct kref *kref)
1084 {
1085         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1086
1087         gss_free(gss_auth);
1088 }
1089
1090 static void
1091 gss_put_auth(struct gss_auth *gss_auth)
1092 {
1093         kref_put(&gss_auth->kref, gss_free_callback);
1094 }
1095
1096 static void
1097 gss_destroy(struct rpc_auth *auth)
1098 {
1099         struct gss_auth *gss_auth = container_of(auth,
1100                         struct gss_auth, rpc_auth);
1101
1102         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
1103                         auth, auth->au_flavor);
1104
1105         if (hash_hashed(&gss_auth->hash)) {
1106                 spin_lock(&gss_auth_hash_lock);
1107                 hash_del(&gss_auth->hash);
1108                 spin_unlock(&gss_auth_hash_lock);
1109         }
1110
1111         gss_pipe_free(gss_auth->gss_pipe[0]);
1112         gss_auth->gss_pipe[0] = NULL;
1113         gss_pipe_free(gss_auth->gss_pipe[1]);
1114         gss_auth->gss_pipe[1] = NULL;
1115         rpcauth_destroy_credcache(auth);
1116
1117         gss_put_auth(gss_auth);
1118 }
1119
1120 /*
1121  * Auths may be shared between rpc clients that were cloned from a
1122  * common client with the same xprt, if they also share the flavor and
1123  * target_name.
1124  *
1125  * The auth is looked up from the oldest parent sharing the same
1126  * cl_xprt, and the auth itself references only that common parent
1127  * (which is guaranteed to last as long as any of its descendants).
1128  */
1129 static struct gss_auth *
1130 gss_auth_find_or_add_hashed(struct rpc_auth_create_args *args,
1131                 struct rpc_clnt *clnt,
1132                 struct gss_auth *new)
1133 {
1134         struct gss_auth *gss_auth;
1135         unsigned long hashval = (unsigned long)clnt;
1136
1137         spin_lock(&gss_auth_hash_lock);
1138         hash_for_each_possible(gss_auth_hash_table,
1139                         gss_auth,
1140                         hash,
1141                         hashval) {
1142                 if (gss_auth->client != clnt)
1143                         continue;
1144                 if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1145                         continue;
1146                 if (gss_auth->target_name != args->target_name) {
1147                         if (gss_auth->target_name == NULL)
1148                                 continue;
1149                         if (args->target_name == NULL)
1150                                 continue;
1151                         if (strcmp(gss_auth->target_name, args->target_name))
1152                                 continue;
1153                 }
1154                 if (!atomic_inc_not_zero(&gss_auth->rpc_auth.au_count))
1155                         continue;
1156                 goto out;
1157         }
1158         if (new)
1159                 hash_add(gss_auth_hash_table, &new->hash, hashval);
1160         gss_auth = new;
1161 out:
1162         spin_unlock(&gss_auth_hash_lock);
1163         return gss_auth;
1164 }
1165
1166 static struct gss_auth *
1167 gss_create_hashed(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1168 {
1169         struct gss_auth *gss_auth;
1170         struct gss_auth *new;
1171
1172         gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1173         if (gss_auth != NULL)
1174                 goto out;
1175         new = gss_create_new(args, clnt);
1176         if (IS_ERR(new))
1177                 return new;
1178         gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1179         if (gss_auth != new)
1180                 gss_destroy(&new->rpc_auth);
1181 out:
1182         return gss_auth;
1183 }
1184
1185 static struct rpc_auth *
1186 gss_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1187 {
1188         struct gss_auth *gss_auth;
1189         struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
1190
1191         while (clnt != clnt->cl_parent) {
1192                 struct rpc_clnt *parent = clnt->cl_parent;
1193                 /* Find the original parent for this transport */
1194                 if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
1195                         break;
1196                 clnt = parent;
1197         }
1198
1199         gss_auth = gss_create_hashed(args, clnt);
1200         if (IS_ERR(gss_auth))
1201                 return ERR_CAST(gss_auth);
1202         return &gss_auth->rpc_auth;
1203 }
1204
1205 /*
1206  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
1207  * to the server with the GSS control procedure field set to
1208  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1209  * all RPCSEC_GSS state associated with that context.
1210  */
1211 static int
1212 gss_destroying_context(struct rpc_cred *cred)
1213 {
1214         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1215         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1216         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1217         struct rpc_task *task;
1218
1219         if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
1220                 return 0;
1221
1222         ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1223         cred->cr_ops = &gss_nullops;
1224
1225         /* Take a reference to ensure the cred will be destroyed either
1226          * by the RPC call or by the put_rpccred() below */
1227         get_rpccred(cred);
1228
1229         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
1230         if (!IS_ERR(task))
1231                 rpc_put_task(task);
1232
1233         put_rpccred(cred);
1234         return 1;
1235 }
1236
1237 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1238  * to create a new cred or context, so they check that things have been
1239  * allocated before freeing them. */
1240 static void
1241 gss_do_free_ctx(struct gss_cl_ctx *ctx)
1242 {
1243         dprintk("RPC:       %s\n", __func__);
1244
1245         gss_delete_sec_context(&ctx->gc_gss_ctx);
1246         kfree(ctx->gc_wire_ctx.data);
1247         kfree(ctx->gc_acceptor.data);
1248         kfree(ctx);
1249 }
1250
1251 static void
1252 gss_free_ctx_callback(struct rcu_head *head)
1253 {
1254         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1255         gss_do_free_ctx(ctx);
1256 }
1257
1258 static void
1259 gss_free_ctx(struct gss_cl_ctx *ctx)
1260 {
1261         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1262 }
1263
1264 static void
1265 gss_free_cred(struct gss_cred *gss_cred)
1266 {
1267         dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1268         kfree(gss_cred);
1269 }
1270
1271 static void
1272 gss_free_cred_callback(struct rcu_head *head)
1273 {
1274         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1275         gss_free_cred(gss_cred);
1276 }
1277
1278 static void
1279 gss_destroy_nullcred(struct rpc_cred *cred)
1280 {
1281         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1282         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1283         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1284
1285         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1286         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1287         if (ctx)
1288                 gss_put_ctx(ctx);
1289         gss_put_auth(gss_auth);
1290 }
1291
1292 static void
1293 gss_destroy_cred(struct rpc_cred *cred)
1294 {
1295
1296         if (gss_destroying_context(cred))
1297                 return;
1298         gss_destroy_nullcred(cred);
1299 }
1300
1301 static int
1302 gss_hash_cred(struct auth_cred *acred, unsigned int hashbits)
1303 {
1304         return hash_64(from_kuid(&init_user_ns, acred->uid), hashbits);
1305 }
1306
1307 /*
1308  * Lookup RPCSEC_GSS cred for the current process
1309  */
1310 static struct rpc_cred *
1311 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1312 {
1313         return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS);
1314 }
1315
1316 static struct rpc_cred *
1317 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp)
1318 {
1319         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1320         struct gss_cred *cred = NULL;
1321         int err = -ENOMEM;
1322
1323         dprintk("RPC:       %s for uid %d, flavor %d\n",
1324                 __func__, from_kuid(&init_user_ns, acred->uid),
1325                 auth->au_flavor);
1326
1327         if (!(cred = kzalloc(sizeof(*cred), gfp)))
1328                 goto out_err;
1329
1330         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1331         /*
1332          * Note: in order to force a call to call_refresh(), we deliberately
1333          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1334          */
1335         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1336         cred->gc_service = gss_auth->service;
1337         cred->gc_principal = NULL;
1338         if (acred->machine_cred)
1339                 cred->gc_principal = acred->principal;
1340         kref_get(&gss_auth->kref);
1341         return &cred->gc_base;
1342
1343 out_err:
1344         dprintk("RPC:       %s failed with error %d\n", __func__, err);
1345         return ERR_PTR(err);
1346 }
1347
1348 static int
1349 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1350 {
1351         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1352         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1353         int err;
1354
1355         do {
1356                 err = gss_create_upcall(gss_auth, gss_cred);
1357         } while (err == -EAGAIN);
1358         return err;
1359 }
1360
1361 static char *
1362 gss_stringify_acceptor(struct rpc_cred *cred)
1363 {
1364         char *string = NULL;
1365         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1366         struct gss_cl_ctx *ctx;
1367         unsigned int len;
1368         struct xdr_netobj *acceptor;
1369
1370         rcu_read_lock();
1371         ctx = rcu_dereference(gss_cred->gc_ctx);
1372         if (!ctx)
1373                 goto out;
1374
1375         len = ctx->gc_acceptor.len;
1376         rcu_read_unlock();
1377
1378         /* no point if there's no string */
1379         if (!len)
1380                 return NULL;
1381 realloc:
1382         string = kmalloc(len + 1, GFP_KERNEL);
1383         if (!string)
1384                 return NULL;
1385
1386         rcu_read_lock();
1387         ctx = rcu_dereference(gss_cred->gc_ctx);
1388
1389         /* did the ctx disappear or was it replaced by one with no acceptor? */
1390         if (!ctx || !ctx->gc_acceptor.len) {
1391                 kfree(string);
1392                 string = NULL;
1393                 goto out;
1394         }
1395
1396         acceptor = &ctx->gc_acceptor;
1397
1398         /*
1399          * Did we find a new acceptor that's longer than the original? Allocate
1400          * a longer buffer and try again.
1401          */
1402         if (len < acceptor->len) {
1403                 len = acceptor->len;
1404                 rcu_read_unlock();
1405                 kfree(string);
1406                 goto realloc;
1407         }
1408
1409         memcpy(string, acceptor->data, acceptor->len);
1410         string[acceptor->len] = '\0';
1411 out:
1412         rcu_read_unlock();
1413         return string;
1414 }
1415
1416 /*
1417  * Returns -EACCES if GSS context is NULL or will expire within the
1418  * timeout (miliseconds)
1419  */
1420 static int
1421 gss_key_timeout(struct rpc_cred *rc)
1422 {
1423         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1424         struct gss_cl_ctx *ctx;
1425         unsigned long timeout = jiffies + (gss_key_expire_timeo * HZ);
1426         int ret = 0;
1427
1428         rcu_read_lock();
1429         ctx = rcu_dereference(gss_cred->gc_ctx);
1430         if (!ctx || time_after(timeout, ctx->gc_expiry))
1431                 ret = -EACCES;
1432         rcu_read_unlock();
1433
1434         return ret;
1435 }
1436
1437 static int
1438 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1439 {
1440         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1441         struct gss_cl_ctx *ctx;
1442         int ret;
1443
1444         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1445                 goto out;
1446         /* Don't match with creds that have expired. */
1447         rcu_read_lock();
1448         ctx = rcu_dereference(gss_cred->gc_ctx);
1449         if (!ctx || time_after(jiffies, ctx->gc_expiry)) {
1450                 rcu_read_unlock();
1451                 return 0;
1452         }
1453         rcu_read_unlock();
1454         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1455                 return 0;
1456 out:
1457         if (acred->principal != NULL) {
1458                 if (gss_cred->gc_principal == NULL)
1459                         return 0;
1460                 ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1461                 goto check_expire;
1462         }
1463         if (gss_cred->gc_principal != NULL)
1464                 return 0;
1465         ret = uid_eq(rc->cr_uid, acred->uid);
1466
1467 check_expire:
1468         if (ret == 0)
1469                 return ret;
1470
1471         /* Notify acred users of GSS context expiration timeout */
1472         if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags) &&
1473             (gss_key_timeout(rc) != 0)) {
1474                 /* test will now be done from generic cred */
1475                 test_and_clear_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
1476                 /* tell NFS layer that key will expire soon */
1477                 set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
1478         }
1479         return ret;
1480 }
1481
1482 /*
1483 * Marshal credentials.
1484 * Maybe we should keep a cached credential for performance reasons.
1485 */
1486 static __be32 *
1487 gss_marshal(struct rpc_task *task, __be32 *p)
1488 {
1489         struct rpc_rqst *req = task->tk_rqstp;
1490         struct rpc_cred *cred = req->rq_cred;
1491         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1492                                                  gc_base);
1493         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1494         __be32          *cred_len;
1495         u32             maj_stat = 0;
1496         struct xdr_netobj mic;
1497         struct kvec     iov;
1498         struct xdr_buf  verf_buf;
1499
1500         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1501
1502         *p++ = htonl(RPC_AUTH_GSS);
1503         cred_len = p++;
1504
1505         spin_lock(&ctx->gc_seq_lock);
1506         req->rq_seqno = ctx->gc_seq++;
1507         spin_unlock(&ctx->gc_seq_lock);
1508
1509         *p++ = htonl((u32) RPC_GSS_VERSION);
1510         *p++ = htonl((u32) ctx->gc_proc);
1511         *p++ = htonl((u32) req->rq_seqno);
1512         *p++ = htonl((u32) gss_cred->gc_service);
1513         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1514         *cred_len = htonl((p - (cred_len + 1)) << 2);
1515
1516         /* We compute the checksum for the verifier over the xdr-encoded bytes
1517          * starting with the xid and ending at the end of the credential: */
1518         iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
1519                                         req->rq_snd_buf.head[0].iov_base);
1520         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1521         xdr_buf_from_iov(&iov, &verf_buf);
1522
1523         /* set verifier flavor*/
1524         *p++ = htonl(RPC_AUTH_GSS);
1525
1526         mic.data = (u8 *)(p + 1);
1527         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1528         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1529                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1530         } else if (maj_stat != 0) {
1531                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1532                 goto out_put_ctx;
1533         }
1534         p = xdr_encode_opaque(p, NULL, mic.len);
1535         gss_put_ctx(ctx);
1536         return p;
1537 out_put_ctx:
1538         gss_put_ctx(ctx);
1539         return NULL;
1540 }
1541
1542 static int gss_renew_cred(struct rpc_task *task)
1543 {
1544         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1545         struct gss_cred *gss_cred = container_of(oldcred,
1546                                                  struct gss_cred,
1547                                                  gc_base);
1548         struct rpc_auth *auth = oldcred->cr_auth;
1549         struct auth_cred acred = {
1550                 .uid = oldcred->cr_uid,
1551                 .principal = gss_cred->gc_principal,
1552                 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
1553         };
1554         struct rpc_cred *new;
1555
1556         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1557         if (IS_ERR(new))
1558                 return PTR_ERR(new);
1559         task->tk_rqstp->rq_cred = new;
1560         put_rpccred(oldcred);
1561         return 0;
1562 }
1563
1564 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1565 {
1566         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1567                 unsigned long now = jiffies;
1568                 unsigned long begin, expire;
1569                 struct gss_cred *gss_cred;
1570
1571                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1572                 begin = gss_cred->gc_upcall_timestamp;
1573                 expire = begin + gss_expired_cred_retry_delay * HZ;
1574
1575                 if (time_in_range_open(now, begin, expire))
1576                         return 1;
1577         }
1578         return 0;
1579 }
1580
1581 /*
1582 * Refresh credentials. XXX - finish
1583 */
1584 static int
1585 gss_refresh(struct rpc_task *task)
1586 {
1587         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1588         int ret = 0;
1589
1590         if (gss_cred_is_negative_entry(cred))
1591                 return -EKEYEXPIRED;
1592
1593         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1594                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1595                 ret = gss_renew_cred(task);
1596                 if (ret < 0)
1597                         goto out;
1598                 cred = task->tk_rqstp->rq_cred;
1599         }
1600
1601         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1602                 ret = gss_refresh_upcall(task);
1603 out:
1604         return ret;
1605 }
1606
1607 /* Dummy refresh routine: used only when destroying the context */
1608 static int
1609 gss_refresh_null(struct rpc_task *task)
1610 {
1611         return 0;
1612 }
1613
1614 static __be32 *
1615 gss_validate(struct rpc_task *task, __be32 *p)
1616 {
1617         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1618         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1619         __be32          seq;
1620         struct kvec     iov;
1621         struct xdr_buf  verf_buf;
1622         struct xdr_netobj mic;
1623         u32             flav,len;
1624         u32             maj_stat;
1625         __be32          *ret = ERR_PTR(-EIO);
1626
1627         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1628
1629         flav = ntohl(*p++);
1630         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1631                 goto out_bad;
1632         if (flav != RPC_AUTH_GSS)
1633                 goto out_bad;
1634         seq = htonl(task->tk_rqstp->rq_seqno);
1635         iov.iov_base = &seq;
1636         iov.iov_len = sizeof(seq);
1637         xdr_buf_from_iov(&iov, &verf_buf);
1638         mic.data = (u8 *)p;
1639         mic.len = len;
1640
1641         ret = ERR_PTR(-EACCES);
1642         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1643         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1644                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1645         if (maj_stat) {
1646                 dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1647                         task->tk_pid, __func__, maj_stat);
1648                 goto out_bad;
1649         }
1650         /* We leave it to unwrap to calculate au_rslack. For now we just
1651          * calculate the length of the verifier: */
1652         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1653         gss_put_ctx(ctx);
1654         dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1655                         task->tk_pid, __func__);
1656         return p + XDR_QUADLEN(len);
1657 out_bad:
1658         gss_put_ctx(ctx);
1659         dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
1660                 PTR_ERR(ret));
1661         return ret;
1662 }
1663
1664 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1665                                 __be32 *p, void *obj)
1666 {
1667         struct xdr_stream xdr;
1668
1669         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1670         encode(rqstp, &xdr, obj);
1671 }
1672
1673 static inline int
1674 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1675                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1676                    __be32 *p, void *obj)
1677 {
1678         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1679         struct xdr_buf  integ_buf;
1680         __be32          *integ_len = NULL;
1681         struct xdr_netobj mic;
1682         u32             offset;
1683         __be32          *q;
1684         struct kvec     *iov;
1685         u32             maj_stat = 0;
1686         int             status = -EIO;
1687
1688         integ_len = p++;
1689         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1690         *p++ = htonl(rqstp->rq_seqno);
1691
1692         gss_wrap_req_encode(encode, rqstp, p, obj);
1693
1694         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1695                                 offset, snd_buf->len - offset))
1696                 return status;
1697         *integ_len = htonl(integ_buf.len);
1698
1699         /* guess whether we're in the head or the tail: */
1700         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1701                 iov = snd_buf->tail;
1702         else
1703                 iov = snd_buf->head;
1704         p = iov->iov_base + iov->iov_len;
1705         mic.data = (u8 *)(p + 1);
1706
1707         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1708         status = -EIO; /* XXX? */
1709         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1710                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1711         else if (maj_stat)
1712                 return status;
1713         q = xdr_encode_opaque(p, NULL, mic.len);
1714
1715         offset = (u8 *)q - (u8 *)p;
1716         iov->iov_len += offset;
1717         snd_buf->len += offset;
1718         return 0;
1719 }
1720
1721 static void
1722 priv_release_snd_buf(struct rpc_rqst *rqstp)
1723 {
1724         int i;
1725
1726         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1727                 __free_page(rqstp->rq_enc_pages[i]);
1728         kfree(rqstp->rq_enc_pages);
1729 }
1730
1731 static int
1732 alloc_enc_pages(struct rpc_rqst *rqstp)
1733 {
1734         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1735         int first, last, i;
1736
1737         if (snd_buf->page_len == 0) {
1738                 rqstp->rq_enc_pages_num = 0;
1739                 return 0;
1740         }
1741
1742         first = snd_buf->page_base >> PAGE_SHIFT;
1743         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_SHIFT;
1744         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1745         rqstp->rq_enc_pages
1746                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1747                                 GFP_NOFS);
1748         if (!rqstp->rq_enc_pages)
1749                 goto out;
1750         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1751                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1752                 if (rqstp->rq_enc_pages[i] == NULL)
1753                         goto out_free;
1754         }
1755         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1756         return 0;
1757 out_free:
1758         rqstp->rq_enc_pages_num = i;
1759         priv_release_snd_buf(rqstp);
1760 out:
1761         return -EAGAIN;
1762 }
1763
1764 static inline int
1765 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1766                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1767                   __be32 *p, void *obj)
1768 {
1769         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1770         u32             offset;
1771         u32             maj_stat;
1772         int             status;
1773         __be32          *opaque_len;
1774         struct page     **inpages;
1775         int             first;
1776         int             pad;
1777         struct kvec     *iov;
1778         char            *tmp;
1779
1780         opaque_len = p++;
1781         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1782         *p++ = htonl(rqstp->rq_seqno);
1783
1784         gss_wrap_req_encode(encode, rqstp, p, obj);
1785
1786         status = alloc_enc_pages(rqstp);
1787         if (status)
1788                 return status;
1789         first = snd_buf->page_base >> PAGE_SHIFT;
1790         inpages = snd_buf->pages + first;
1791         snd_buf->pages = rqstp->rq_enc_pages;
1792         snd_buf->page_base -= first << PAGE_SHIFT;
1793         /*
1794          * Give the tail its own page, in case we need extra space in the
1795          * head when wrapping:
1796          *
1797          * call_allocate() allocates twice the slack space required
1798          * by the authentication flavor to rq_callsize.
1799          * For GSS, slack is GSS_CRED_SLACK.
1800          */
1801         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1802                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1803                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1804                 snd_buf->tail[0].iov_base = tmp;
1805         }
1806         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1807         /* slack space should prevent this ever happening: */
1808         BUG_ON(snd_buf->len > snd_buf->buflen);
1809         status = -EIO;
1810         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1811          * done anyway, so it's safe to put the request on the wire: */
1812         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1813                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1814         else if (maj_stat)
1815                 return status;
1816
1817         *opaque_len = htonl(snd_buf->len - offset);
1818         /* guess whether we're in the head or the tail: */
1819         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1820                 iov = snd_buf->tail;
1821         else
1822                 iov = snd_buf->head;
1823         p = iov->iov_base + iov->iov_len;
1824         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1825         memset(p, 0, pad);
1826         iov->iov_len += pad;
1827         snd_buf->len += pad;
1828
1829         return 0;
1830 }
1831
1832 static int
1833 gss_wrap_req(struct rpc_task *task,
1834              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1835 {
1836         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1837         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1838                         gc_base);
1839         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1840         int             status = -EIO;
1841
1842         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1843         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1844                 /* The spec seems a little ambiguous here, but I think that not
1845                  * wrapping context destruction requests makes the most sense.
1846                  */
1847                 gss_wrap_req_encode(encode, rqstp, p, obj);
1848                 status = 0;
1849                 goto out;
1850         }
1851         switch (gss_cred->gc_service) {
1852         case RPC_GSS_SVC_NONE:
1853                 gss_wrap_req_encode(encode, rqstp, p, obj);
1854                 status = 0;
1855                 break;
1856         case RPC_GSS_SVC_INTEGRITY:
1857                 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1858                 break;
1859         case RPC_GSS_SVC_PRIVACY:
1860                 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1861                 break;
1862         }
1863 out:
1864         gss_put_ctx(ctx);
1865         dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1866         return status;
1867 }
1868
1869 static inline int
1870 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1871                 struct rpc_rqst *rqstp, __be32 **p)
1872 {
1873         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1874         struct xdr_buf integ_buf;
1875         struct xdr_netobj mic;
1876         u32 data_offset, mic_offset;
1877         u32 integ_len;
1878         u32 maj_stat;
1879         int status = -EIO;
1880
1881         integ_len = ntohl(*(*p)++);
1882         if (integ_len & 3)
1883                 return status;
1884         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1885         mic_offset = integ_len + data_offset;
1886         if (mic_offset > rcv_buf->len)
1887                 return status;
1888         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1889                 return status;
1890
1891         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1892                                 mic_offset - data_offset))
1893                 return status;
1894
1895         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1896                 return status;
1897
1898         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1899         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1900                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1901         if (maj_stat != GSS_S_COMPLETE)
1902                 return status;
1903         return 0;
1904 }
1905
1906 static inline int
1907 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1908                 struct rpc_rqst *rqstp, __be32 **p)
1909 {
1910         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1911         u32 offset;
1912         u32 opaque_len;
1913         u32 maj_stat;
1914         int status = -EIO;
1915
1916         opaque_len = ntohl(*(*p)++);
1917         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1918         if (offset + opaque_len > rcv_buf->len)
1919                 return status;
1920         /* remove padding: */
1921         rcv_buf->len = offset + opaque_len;
1922
1923         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1924         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1925                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1926         if (maj_stat != GSS_S_COMPLETE)
1927                 return status;
1928         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1929                 return status;
1930
1931         return 0;
1932 }
1933
1934 static int
1935 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1936                       __be32 *p, void *obj)
1937 {
1938         struct xdr_stream xdr;
1939
1940         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1941         return decode(rqstp, &xdr, obj);
1942 }
1943
1944 static int
1945 gss_unwrap_resp(struct rpc_task *task,
1946                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1947 {
1948         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1949         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1950                         gc_base);
1951         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1952         __be32          *savedp = p;
1953         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1954         int             savedlen = head->iov_len;
1955         int             status = -EIO;
1956
1957         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1958                 goto out_decode;
1959         switch (gss_cred->gc_service) {
1960         case RPC_GSS_SVC_NONE:
1961                 break;
1962         case RPC_GSS_SVC_INTEGRITY:
1963                 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1964                 if (status)
1965                         goto out;
1966                 break;
1967         case RPC_GSS_SVC_PRIVACY:
1968                 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1969                 if (status)
1970                         goto out;
1971                 break;
1972         }
1973         /* take into account extra slack for integrity and privacy cases: */
1974         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1975                                                 + (savedlen - head->iov_len);
1976 out_decode:
1977         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
1978 out:
1979         gss_put_ctx(ctx);
1980         dprintk("RPC: %5u %s returning %d\n",
1981                 task->tk_pid, __func__, status);
1982         return status;
1983 }
1984
1985 static const struct rpc_authops authgss_ops = {
1986         .owner          = THIS_MODULE,
1987         .au_flavor      = RPC_AUTH_GSS,
1988         .au_name        = "RPCSEC_GSS",
1989         .create         = gss_create,
1990         .destroy        = gss_destroy,
1991         .hash_cred      = gss_hash_cred,
1992         .lookup_cred    = gss_lookup_cred,
1993         .crcreate       = gss_create_cred,
1994         .list_pseudoflavors = gss_mech_list_pseudoflavors,
1995         .info2flavor    = gss_mech_info2flavor,
1996         .flavor2info    = gss_mech_flavor2info,
1997 };
1998
1999 static const struct rpc_credops gss_credops = {
2000         .cr_name                = "AUTH_GSS",
2001         .crdestroy              = gss_destroy_cred,
2002         .cr_init                = gss_cred_init,
2003         .crbind                 = rpcauth_generic_bind_cred,
2004         .crmatch                = gss_match,
2005         .crmarshal              = gss_marshal,
2006         .crrefresh              = gss_refresh,
2007         .crvalidate             = gss_validate,
2008         .crwrap_req             = gss_wrap_req,
2009         .crunwrap_resp          = gss_unwrap_resp,
2010         .crkey_timeout          = gss_key_timeout,
2011         .crstringify_acceptor   = gss_stringify_acceptor,
2012 };
2013
2014 static const struct rpc_credops gss_nullops = {
2015         .cr_name                = "AUTH_GSS",
2016         .crdestroy              = gss_destroy_nullcred,
2017         .crbind                 = rpcauth_generic_bind_cred,
2018         .crmatch                = gss_match,
2019         .crmarshal              = gss_marshal,
2020         .crrefresh              = gss_refresh_null,
2021         .crvalidate             = gss_validate,
2022         .crwrap_req             = gss_wrap_req,
2023         .crunwrap_resp          = gss_unwrap_resp,
2024         .crstringify_acceptor   = gss_stringify_acceptor,
2025 };
2026
2027 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
2028         .upcall         = rpc_pipe_generic_upcall,
2029         .downcall       = gss_pipe_downcall,
2030         .destroy_msg    = gss_pipe_destroy_msg,
2031         .open_pipe      = gss_pipe_open_v0,
2032         .release_pipe   = gss_pipe_release,
2033 };
2034
2035 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
2036         .upcall         = rpc_pipe_generic_upcall,
2037         .downcall       = gss_pipe_downcall,
2038         .destroy_msg    = gss_pipe_destroy_msg,
2039         .open_pipe      = gss_pipe_open_v1,
2040         .release_pipe   = gss_pipe_release,
2041 };
2042
2043 static __net_init int rpcsec_gss_init_net(struct net *net)
2044 {
2045         return gss_svc_init_net(net);
2046 }
2047
2048 static __net_exit void rpcsec_gss_exit_net(struct net *net)
2049 {
2050         gss_svc_shutdown_net(net);
2051 }
2052
2053 static struct pernet_operations rpcsec_gss_net_ops = {
2054         .init = rpcsec_gss_init_net,
2055         .exit = rpcsec_gss_exit_net,
2056 };
2057
2058 /*
2059  * Initialize RPCSEC_GSS module
2060  */
2061 static int __init init_rpcsec_gss(void)
2062 {
2063         int err = 0;
2064
2065         err = rpcauth_register(&authgss_ops);
2066         if (err)
2067                 goto out;
2068         err = gss_svc_init();
2069         if (err)
2070                 goto out_unregister;
2071         err = register_pernet_subsys(&rpcsec_gss_net_ops);
2072         if (err)
2073                 goto out_svc_exit;
2074         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
2075         return 0;
2076 out_svc_exit:
2077         gss_svc_shutdown();
2078 out_unregister:
2079         rpcauth_unregister(&authgss_ops);
2080 out:
2081         return err;
2082 }
2083
2084 static void __exit exit_rpcsec_gss(void)
2085 {
2086         unregister_pernet_subsys(&rpcsec_gss_net_ops);
2087         gss_svc_shutdown();
2088         rpcauth_unregister(&authgss_ops);
2089         rcu_barrier(); /* Wait for completion of call_rcu()'s */
2090 }
2091
2092 MODULE_ALIAS("rpc-auth-6");
2093 MODULE_LICENSE("GPL");
2094 module_param_named(expired_cred_retry_delay,
2095                    gss_expired_cred_retry_delay,
2096                    uint, 0644);
2097 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
2098                 "the RPC engine retries an expired credential");
2099
2100 module_param_named(key_expire_timeo,
2101                    gss_key_expire_timeo,
2102                    uint, 0644);
2103 MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
2104                 "credential keys lifetime where the NFS layer cleans up "
2105                 "prior to key expiration");
2106
2107 module_init(init_rpcsec_gss)
2108 module_exit(exit_rpcsec_gss)