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  * $Id$
  38  */
  39
  40
  41 #include <linux/module.h>
  42 #include <linux/init.h>
  43 #include <linux/types.h>
  44 #include <linux/slab.h>
  45 #include <linux/sched.h>
  46 #include <linux/pagemap.h>
  47 #include <linux/sunrpc/clnt.h>
  48 #include <linux/sunrpc/auth.h>
  49 #include <linux/sunrpc/auth_gss.h>
  50 #include <linux/sunrpc/svcauth_gss.h>
  51 #include <linux/sunrpc/gss_err.h>
  52 #include <linux/workqueue.h>
  53 #include <linux/sunrpc/rpc_pipe_fs.h>
  54 #include <linux/sunrpc/gss_api.h>
  55 #include <asm/uaccess.h>
  56
  57 static const struct rpc_authops authgss_ops;
  58
  59 static const struct rpc_credops gss_credops;
  60
  61 #ifdef RPC_DEBUG
  62 # define RPCDBG_FACILITY        RPCDBG_AUTH
  63 #endif
  64
  65 #define NFS_NGROUPS     16
  66
  67 #define GSS_CRED_SLACK          1024            /* XXX: unused */
  68 /* length of a krb5 verifier (48), plus data added before arguments when
  69  * using integrity (two 4-byte integers): */
  70 #define GSS_VERF_SLACK          100
  71
  72 /* XXX this define must match the gssd define
  73 * as it is passed to gssd to signal the use of
  74 * machine creds should be part of the shared rpc interface */
  75
  76 #define CA_RUN_AS_MACHINE  0x00000200
  77
  78 /* dump the buffer in `emacs-hexl' style */
  79 #define isprint(c)      ((c > 0x1f) && (c < 0x7f))
  80
  81 static DEFINE_RWLOCK(gss_ctx_lock);
  82
  83 struct gss_auth {
  84         struct rpc_auth rpc_auth;
  85         struct gss_api_mech *mech;
  86         enum rpc_gss_svc service;
  87         struct rpc_clnt *client;
  88         struct dentry *dentry;
  89 };
  90
  91 static void gss_destroy_ctx(struct gss_cl_ctx *);
  92 static struct rpc_pipe_ops gss_upcall_ops;
  93
  94 static inline struct gss_cl_ctx *
  95 gss_get_ctx(struct gss_cl_ctx *ctx)
  96 {
  97         atomic_inc(&ctx->count);
  98         return ctx;
  99 }
 100
 101 static inline void
 102 gss_put_ctx(struct gss_cl_ctx *ctx)
 103 {
 104         if (atomic_dec_and_test(&ctx->count))
 105                 gss_destroy_ctx(ctx);
 106 }
 107
 108 static void
 109 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 110 {
 111         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 112         struct gss_cl_ctx *old;
 113         write_lock(&gss_ctx_lock);
 114         old = gss_cred->gc_ctx;
 115         gss_cred->gc_ctx = ctx;
 116         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 117         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 118         write_unlock(&gss_ctx_lock);
 119         if (old)
 120                 gss_put_ctx(old);
 121 }
 122
 123 static int
 124 gss_cred_is_uptodate_ctx(struct rpc_cred *cred)
 125 {
 126         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 127         int res = 0;
 128
 129         read_lock(&gss_ctx_lock);
 130         if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) && gss_cred->gc_ctx)
 131                 res = 1;
 132         read_unlock(&gss_ctx_lock);
 133         return res;
 134 }
 135
 136 static const void *
 137 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 138 {
 139         const void *q = (const void *)((const char *)p + len);
 140         if (unlikely(q > end || q < p))
 141                 return ERR_PTR(-EFAULT);
 142         memcpy(res, p, len);
 143         return q;
 144 }
 145
 146 static inline const void *
 147 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 148 {
 149         const void *q;
 150         unsigned int len;
 151
 152         p = simple_get_bytes(p, end, &len, sizeof(len));
 153         if (IS_ERR(p))
 154                 return p;
 155         q = (const void *)((const char *)p + len);
 156         if (unlikely(q > end || q < p))
 157                 return ERR_PTR(-EFAULT);
 158         dest->data = kmemdup(p, len, GFP_KERNEL);
 159         if (unlikely(dest->data == NULL))
 160                 return ERR_PTR(-ENOMEM);
 161         dest->len = len;
 162         return q;
 163 }
 164
 165 static struct gss_cl_ctx *
 166 gss_cred_get_ctx(struct rpc_cred *cred)
 167 {
 168         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 169         struct gss_cl_ctx *ctx = NULL;
 170
 171         read_lock(&gss_ctx_lock);
 172         if (gss_cred->gc_ctx)
 173                 ctx = gss_get_ctx(gss_cred->gc_ctx);
 174         read_unlock(&gss_ctx_lock);
 175         return ctx;
 176 }
 177
 178 static struct gss_cl_ctx *
 179 gss_alloc_context(void)
 180 {
 181         struct gss_cl_ctx *ctx;
 182
 183         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 184         if (ctx != NULL) {
 185                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 186                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 187                 spin_lock_init(&ctx->gc_seq_lock);
 188                 atomic_set(&ctx->count,1);
 189         }
 190         return ctx;
 191 }
 192
 193 #define GSSD_MIN_TIMEOUT (60 * 60)
 194 static const void *
 195 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 196 {
 197         const void *q;
 198         unsigned int seclen;
 199         unsigned int timeout;
 200         u32 window_size;
 201         int ret;
 202
 203         /* First unsigned int gives the lifetime (in seconds) of the cred */
 204         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 205         if (IS_ERR(p))
 206                 goto err;
 207         if (timeout == 0)
 208                 timeout = GSSD_MIN_TIMEOUT;
 209         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
 210         /* Sequence number window. Determines the maximum number of simultaneous requests */
 211         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 212         if (IS_ERR(p))
 213                 goto err;
 214         ctx->gc_win = window_size;
 215         /* gssd signals an error by passing ctx->gc_win = 0: */
 216         if (ctx->gc_win == 0) {
 217                 /* in which case, p points to  an error code which we ignore */
 218                 p = ERR_PTR(-EACCES);
 219                 goto err;
 220         }
 221         /* copy the opaque wire context */
 222         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 223         if (IS_ERR(p))
 224                 goto err;
 225         /* import the opaque security context */
 226         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 227         if (IS_ERR(p))
 228                 goto err;
 229         q = (const void *)((const char *)p + seclen);
 230         if (unlikely(q > end || q < p)) {
 231                 p = ERR_PTR(-EFAULT);
 232                 goto err;
 233         }
 234         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
 235         if (ret < 0) {
 236                 p = ERR_PTR(ret);
 237                 goto err;
 238         }
 239         return q;
 240 err:
 241         dprintk("RPC:       gss_fill_context returning %ld\n", -PTR_ERR(p));
 242         return p;
 243 }
 244
 245
 246 struct gss_upcall_msg {
 247         atomic_t count;
 248         uid_t   uid;
 249         struct rpc_pipe_msg msg;
 250         struct list_head list;
 251         struct gss_auth *auth;
 252         struct rpc_wait_queue rpc_waitqueue;
 253         wait_queue_head_t waitqueue;
 254         struct gss_cl_ctx *ctx;
 255 };
 256
 257 static void
 258 gss_release_msg(struct gss_upcall_msg *gss_msg)
 259 {
 260         if (!atomic_dec_and_test(&gss_msg->count))
 261                 return;
 262         BUG_ON(!list_empty(&gss_msg->list));
 263         if (gss_msg->ctx != NULL)
 264                 gss_put_ctx(gss_msg->ctx);
 265         kfree(gss_msg);
 266 }
 267
 268 static struct gss_upcall_msg *
 269 __gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
 270 {
 271         struct gss_upcall_msg *pos;
 272         list_for_each_entry(pos, &rpci->in_downcall, list) {
 273                 if (pos->uid != uid)
 274                         continue;
 275                 atomic_inc(&pos->count);
 276                 dprintk("RPC:       gss_find_upcall found msg %p\n", pos);
 277                 return pos;
 278         }
 279         dprintk("RPC:       gss_find_upcall found nothing\n");
 280         return NULL;
 281 }
 282
 283 /* Try to add a upcall to the pipefs queue.
 284  * If an upcall owned by our uid already exists, then we return a reference
 285  * to that upcall instead of adding the new upcall.
 286  */
 287 static inline struct gss_upcall_msg *
 288 gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
 289 {
 290         struct inode *inode = gss_auth->dentry->d_inode;
 291         struct rpc_inode *rpci = RPC_I(inode);
 292         struct gss_upcall_msg *old;
 293
 294         spin_lock(&inode->i_lock);
 295         old = __gss_find_upcall(rpci, gss_msg->uid);
 296         if (old == NULL) {
 297                 atomic_inc(&gss_msg->count);
 298                 list_add(&gss_msg->list, &rpci->in_downcall);
 299         } else
 300                 gss_msg = old;
 301         spin_unlock(&inode->i_lock);
 302         return gss_msg;
 303 }
 304
 305 static void
 306 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 307 {
 308         list_del_init(&gss_msg->list);
 309         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 310         wake_up_all(&gss_msg->waitqueue);
 311         atomic_dec(&gss_msg->count);
 312 }
 313
 314 static void
 315 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 316 {
 317         struct gss_auth *gss_auth = gss_msg->auth;
 318         struct inode *inode = gss_auth->dentry->d_inode;
 319
 320         if (list_empty(&gss_msg->list))
 321                 return;
 322         spin_lock(&inode->i_lock);
 323         if (!list_empty(&gss_msg->list))
 324                 __gss_unhash_msg(gss_msg);
 325         spin_unlock(&inode->i_lock);
 326 }
 327
 328 static void
 329 gss_upcall_callback(struct rpc_task *task)
 330 {
 331         struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
 332                         struct gss_cred, gc_base);
 333         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 334         struct inode *inode = gss_msg->auth->dentry->d_inode;
 335
 336         if (gss_msg->ctx)
 337                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_get_ctx(gss_msg->ctx));
 338         else
 339                 task->tk_status = gss_msg->msg.errno;
 340         spin_lock(&inode->i_lock);
 341         gss_cred->gc_upcall = NULL;
 342         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 343         spin_unlock(&inode->i_lock);
 344         gss_release_msg(gss_msg);
 345 }
 346
 347 static inline struct gss_upcall_msg *
 348 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid)
 349 {
 350         struct gss_upcall_msg *gss_msg;
 351
 352         gss_msg = kzalloc(sizeof(*gss_msg), GFP_KERNEL);
 353         if (gss_msg != NULL) {
 354                 INIT_LIST_HEAD(&gss_msg->list);
 355                 rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 356                 init_waitqueue_head(&gss_msg->waitqueue);
 357                 atomic_set(&gss_msg->count, 1);
 358                 gss_msg->msg.data = &gss_msg->uid;
 359                 gss_msg->msg.len = sizeof(gss_msg->uid);
 360                 gss_msg->uid = uid;
 361                 gss_msg->auth = gss_auth;
 362         }
 363         return gss_msg;
 364 }
 365
 366 static struct gss_upcall_msg *
 367 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
 368 {
 369         struct gss_upcall_msg *gss_new, *gss_msg;
 370
 371         gss_new = gss_alloc_msg(gss_auth, cred->cr_uid);
 372         if (gss_new == NULL)
 373                 return ERR_PTR(-ENOMEM);
 374         gss_msg = gss_add_msg(gss_auth, gss_new);
 375         if (gss_msg == gss_new) {
 376                 int res = rpc_queue_upcall(gss_auth->dentry->d_inode, &gss_new->msg);
 377                 if (res) {
 378                         gss_unhash_msg(gss_new);
 379                         gss_msg = ERR_PTR(res);
 380                 }
 381         } else
 382                 gss_release_msg(gss_new);
 383         return gss_msg;
 384 }
 385
 386 static inline int
 387 gss_refresh_upcall(struct rpc_task *task)
 388 {
 389         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 390         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 391                         struct gss_auth, rpc_auth);
 392         struct gss_cred *gss_cred = container_of(cred,
 393                         struct gss_cred, gc_base);
 394         struct gss_upcall_msg *gss_msg;
 395         struct inode *inode = gss_auth->dentry->d_inode;
 396         int err = 0;
 397
 398         dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
 399                                                                 cred->cr_uid);
 400         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
 401         if (IS_ERR(gss_msg)) {
 402                 err = PTR_ERR(gss_msg);
 403                 goto out;
 404         }
 405         spin_lock(&inode->i_lock);
 406         if (gss_cred->gc_upcall != NULL)
 407                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL, NULL);
 408         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 409                 task->tk_timeout = 0;
 410                 gss_cred->gc_upcall = gss_msg;
 411                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 412                 atomic_inc(&gss_msg->count);
 413                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback, NULL);
 414         } else
 415                 err = gss_msg->msg.errno;
 416         spin_unlock(&inode->i_lock);
 417         gss_release_msg(gss_msg);
 418 out:
 419         dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
 420                         task->tk_pid, cred->cr_uid, err);
 421         return err;
 422 }
 423
 424 static inline int
 425 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 426 {
 427         struct inode *inode = gss_auth->dentry->d_inode;
 428         struct rpc_cred *cred = &gss_cred->gc_base;
 429         struct gss_upcall_msg *gss_msg;
 430         DEFINE_WAIT(wait);
 431         int err = 0;
 432
 433         dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
 434         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 435         if (IS_ERR(gss_msg)) {
 436                 err = PTR_ERR(gss_msg);
 437                 goto out;
 438         }
 439         for (;;) {
 440                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
 441                 spin_lock(&inode->i_lock);
 442                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 443                         spin_unlock(&inode->i_lock);
 444                         break;
 445                 }
 446                 spin_unlock(&inode->i_lock);
 447                 if (signalled()) {
 448                         err = -ERESTARTSYS;
 449                         goto out_intr;
 450                 }
 451                 schedule();
 452         }
 453         if (gss_msg->ctx)
 454                 gss_cred_set_ctx(cred, gss_get_ctx(gss_msg->ctx));
 455         else
 456                 err = gss_msg->msg.errno;
 457 out_intr:
 458         finish_wait(&gss_msg->waitqueue, &wait);
 459         gss_release_msg(gss_msg);
 460 out:
 461         dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
 462                         cred->cr_uid, err);
 463         return err;
 464 }
 465
 466 static ssize_t
 467 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 468                 char __user *dst, size_t buflen)
 469 {
 470         char *data = (char *)msg->data + msg->copied;
 471         ssize_t mlen = msg->len;
 472         ssize_t left;
 473
 474         if (mlen > buflen)
 475                 mlen = buflen;
 476         left = copy_to_user(dst, data, mlen);
 477         if (left < 0) {
 478                 msg->errno = left;
 479                 return left;
 480         }
 481         mlen -= left;
 482         msg->copied += mlen;
 483         msg->errno = 0;
 484         return mlen;
 485 }
 486
 487 #define MSG_BUF_MAXSIZE 1024
 488
 489 static ssize_t
 490 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 491 {
 492         const void *p, *end;
 493         void *buf;
 494         struct rpc_clnt *clnt;
 495         struct gss_upcall_msg *gss_msg;
 496         struct inode *inode = filp->f_path.dentry->d_inode;
 497         struct gss_cl_ctx *ctx;
 498         uid_t uid;
 499         ssize_t err = -EFBIG;
 500
 501         if (mlen > MSG_BUF_MAXSIZE)
 502                 goto out;
 503         err = -ENOMEM;
 504         buf = kmalloc(mlen, GFP_KERNEL);
 505         if (!buf)
 506                 goto out;
 507
 508         clnt = RPC_I(inode)->private;
 509         err = -EFAULT;
 510         if (copy_from_user(buf, src, mlen))
 511                 goto err;
 512
 513         end = (const void *)((char *)buf + mlen);
 514         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
 515         if (IS_ERR(p)) {
 516                 err = PTR_ERR(p);
 517                 goto err;
 518         }
 519
 520         err = -ENOMEM;
 521         ctx = gss_alloc_context();
 522         if (ctx == NULL)
 523                 goto err;
 524
 525         err = -ENOENT;
 526         /* Find a matching upcall */
 527         spin_lock(&inode->i_lock);
 528         gss_msg = __gss_find_upcall(RPC_I(inode), uid);
 529         if (gss_msg == NULL) {
 530                 spin_unlock(&inode->i_lock);
 531                 goto err_put_ctx;
 532         }
 533         list_del_init(&gss_msg->list);
 534         spin_unlock(&inode->i_lock);
 535
 536         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 537         if (IS_ERR(p)) {
 538                 err = PTR_ERR(p);
 539                 gss_msg->msg.errno = (err == -EACCES) ? -EACCES : -EAGAIN;
 540                 goto err_release_msg;
 541         }
 542         gss_msg->ctx = gss_get_ctx(ctx);
 543         err = mlen;
 544
 545 err_release_msg:
 546         spin_lock(&inode->i_lock);
 547         __gss_unhash_msg(gss_msg);
 548         spin_unlock(&inode->i_lock);
 549         gss_release_msg(gss_msg);
 550 err_put_ctx:
 551         gss_put_ctx(ctx);
 552 err:
 553         kfree(buf);
 554 out:
 555         dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
 556         return err;
 557 }
 558
 559 static void
 560 gss_pipe_release(struct inode *inode)
 561 {
 562         struct rpc_inode *rpci = RPC_I(inode);
 563         struct gss_upcall_msg *gss_msg;
 564
 565         spin_lock(&inode->i_lock);
 566         while (!list_empty(&rpci->in_downcall)) {
 567
 568                 gss_msg = list_entry(rpci->in_downcall.next,
 569                                 struct gss_upcall_msg, list);
 570                 gss_msg->msg.errno = -EPIPE;
 571                 atomic_inc(&gss_msg->count);
 572                 __gss_unhash_msg(gss_msg);
 573                 spin_unlock(&inode->i_lock);
 574                 gss_release_msg(gss_msg);
 575                 spin_lock(&inode->i_lock);
 576         }
 577         spin_unlock(&inode->i_lock);
 578 }
 579
 580 static void
 581 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 582 {
 583         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 584         static unsigned long ratelimit;
 585
 586         if (msg->errno < 0) {
 587                 dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
 588                                 gss_msg);
 589                 atomic_inc(&gss_msg->count);
 590                 gss_unhash_msg(gss_msg);
 591                 if (msg->errno == -ETIMEDOUT) {
 592                         unsigned long now = jiffies;
 593                         if (time_after(now, ratelimit)) {
 594                                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 595                                                     "Please check user daemon is running!\n");
 596                                 ratelimit = now + 15*HZ;
 597                         }
 598                 }
 599                 gss_release_msg(gss_msg);
 600         }
 601 }
 602
 603 /*
 604  * NOTE: we have the opportunity to use different
 605  * parameters based on the input flavor (which must be a pseudoflavor)
 606  */
 607 static struct rpc_auth *
 608 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 609 {
 610         struct gss_auth *gss_auth;
 611         struct rpc_auth * auth;
 612         int err = -ENOMEM; /* XXX? */
 613
 614         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 615
 616         if (!try_module_get(THIS_MODULE))
 617                 return ERR_PTR(err);
 618         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 619                 goto out_dec;
 620         gss_auth->client = clnt;
 621         err = -EINVAL;
 622         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 623         if (!gss_auth->mech) {
 624                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!",
 625                                 __FUNCTION__, flavor);
 626                 goto err_free;
 627         }
 628         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 629         if (gss_auth->service == 0)
 630                 goto err_put_mech;
 631         auth = &gss_auth->rpc_auth;
 632         auth->au_cslack = GSS_CRED_SLACK >> 2;
 633         auth->au_rslack = GSS_VERF_SLACK >> 2;
 634         auth->au_ops = &authgss_ops;
 635         auth->au_flavor = flavor;
 636         atomic_set(&auth->au_count, 1);
 637
 638         gss_auth->dentry = rpc_mkpipe(clnt->cl_dentry, gss_auth->mech->gm_name,
 639                         clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 640         if (IS_ERR(gss_auth->dentry)) {
 641                 err = PTR_ERR(gss_auth->dentry);
 642                 goto err_put_mech;
 643         }
 644
 645         err = rpcauth_init_credcache(auth);
 646         if (err)
 647                 goto err_unlink_pipe;
 648
 649         return auth;
 650 err_unlink_pipe:
 651         rpc_unlink(gss_auth->dentry);
 652 err_put_mech:
 653         gss_mech_put(gss_auth->mech);
 654 err_free:
 655         kfree(gss_auth);
 656 out_dec:
 657         module_put(THIS_MODULE);
 658         return ERR_PTR(err);
 659 }
 660
 661 static void
 662 gss_destroy(struct rpc_auth *auth)
 663 {
 664         struct gss_auth *gss_auth;
 665
 666         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
 667                         auth, auth->au_flavor);
 668
 669         rpcauth_destroy_credcache(auth);
 670
 671         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 672         rpc_unlink(gss_auth->dentry);
 673         gss_auth->dentry = NULL;
 674         gss_mech_put(gss_auth->mech);
 675
 676         kfree(gss_auth);
 677         module_put(THIS_MODULE);
 678 }
 679
 680 /* gss_destroy_cred (and gss_destroy_ctx) are used to clean up after failure
 681  * to create a new cred or context, so they check that things have been
 682  * allocated before freeing them. */
 683 static void
 684 gss_destroy_ctx(struct gss_cl_ctx *ctx)
 685 {
 686         dprintk("RPC:       gss_destroy_ctx\n");
 687
 688         if (ctx->gc_gss_ctx)
 689                 gss_delete_sec_context(&ctx->gc_gss_ctx);
 690
 691         kfree(ctx->gc_wire_ctx.data);
 692         kfree(ctx);
 693 }
 694
 695 static void
 696 gss_free_cred(struct gss_cred *gss_cred)
 697 {
 698         dprintk("RPC:       gss_free_cred %p\n", gss_cred);
 699         if (gss_cred->gc_ctx)
 700                 gss_put_ctx(gss_cred->gc_ctx);
 701         kfree(gss_cred);
 702 }
 703
 704 static void
 705 gss_free_cred_callback(struct rcu_head *head)
 706 {
 707         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
 708         gss_free_cred(gss_cred);
 709 }
 710
 711 static void
 712 gss_destroy_cred(struct rpc_cred *cred)
 713 {
 714         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
 715 }
 716
 717 /*
 718  * Lookup RPCSEC_GSS cred for the current process
 719  */
 720 static struct rpc_cred *
 721 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 722 {
 723         return rpcauth_lookup_credcache(auth, acred, flags);
 724 }
 725
 726 static struct rpc_cred *
 727 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 728 {
 729         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 730         struct gss_cred *cred = NULL;
 731         int err = -ENOMEM;
 732
 733         dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
 734                 acred->uid, auth->au_flavor);
 735
 736         if (!(cred = kzalloc(sizeof(*cred), GFP_KERNEL)))
 737                 goto out_err;
 738
 739         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
 740         /*
 741          * Note: in order to force a call to call_refresh(), we deliberately
 742          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
 743          */
 744         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
 745         cred->gc_service = gss_auth->service;
 746         return &cred->gc_base;
 747
 748 out_err:
 749         dprintk("RPC:       gss_create_cred failed with error %d\n", err);
 750         return ERR_PTR(err);
 751 }
 752
 753 static int
 754 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
 755 {
 756         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 757         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
 758         int err;
 759
 760         do {
 761                 err = gss_create_upcall(gss_auth, gss_cred);
 762         } while (err == -EAGAIN);
 763         return err;
 764 }
 765
 766 static int
 767 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
 768 {
 769         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
 770
 771         /*
 772          * If the searchflags have set RPCAUTH_LOOKUP_NEW, then
 773          * we don't really care if the credential has expired or not,
 774          * since the caller should be prepared to reinitialise it.
 775          */
 776         if ((flags & RPCAUTH_LOOKUP_NEW) && test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
 777                 goto out;
 778         /* Don't match with creds that have expired. */
 779         if (gss_cred->gc_ctx && time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
 780                 return 0;
 781 out:
 782         return (rc->cr_uid == acred->uid);
 783 }
 784
 785 /*
 786 * Marshal credentials.
 787 * Maybe we should keep a cached credential for performance reasons.
 788 */
 789 static __be32 *
 790 gss_marshal(struct rpc_task *task, __be32 *p)
 791 {
 792         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 793         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
 794                                                  gc_base);
 795         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
 796         __be32          *cred_len;
 797         struct rpc_rqst *req = task->tk_rqstp;
 798         u32             maj_stat = 0;
 799         struct xdr_netobj mic;
 800         struct kvec     iov;
 801         struct xdr_buf  verf_buf;
 802
 803         dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
 804
 805         *p++ = htonl(RPC_AUTH_GSS);
 806         cred_len = p++;
 807
 808         spin_lock(&ctx->gc_seq_lock);
 809         req->rq_seqno = ctx->gc_seq++;
 810         spin_unlock(&ctx->gc_seq_lock);
 811
 812         *p++ = htonl((u32) RPC_GSS_VERSION);
 813         *p++ = htonl((u32) ctx->gc_proc);
 814         *p++ = htonl((u32) req->rq_seqno);
 815         *p++ = htonl((u32) gss_cred->gc_service);
 816         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
 817         *cred_len = htonl((p - (cred_len + 1)) << 2);
 818
 819         /* We compute the checksum for the verifier over the xdr-encoded bytes
 820          * starting with the xid and ending at the end of the credential: */
 821         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
 822                                         req->rq_snd_buf.head[0].iov_base);
 823         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
 824         xdr_buf_from_iov(&iov, &verf_buf);
 825
 826         /* set verifier flavor*/
 827         *p++ = htonl(RPC_AUTH_GSS);
 828
 829         mic.data = (u8 *)(p + 1);
 830         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 831         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
 832                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 833         } else if (maj_stat != 0) {
 834                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
 835                 goto out_put_ctx;
 836         }
 837         p = xdr_encode_opaque(p, NULL, mic.len);
 838         gss_put_ctx(ctx);
 839         return p;
 840 out_put_ctx:
 841         gss_put_ctx(ctx);
 842         return NULL;
 843 }
 844
 845 /*
 846 * Refresh credentials. XXX - finish
 847 */
 848 static int
 849 gss_refresh(struct rpc_task *task)
 850 {
 851
 852         if (!gss_cred_is_uptodate_ctx(task->tk_msg.rpc_cred))
 853                 return gss_refresh_upcall(task);
 854         return 0;
 855 }
 856
 857 static __be32 *
 858 gss_validate(struct rpc_task *task, __be32 *p)
 859 {
 860         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 861         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
 862         __be32          seq;
 863         struct kvec     iov;
 864         struct xdr_buf  verf_buf;
 865         struct xdr_netobj mic;
 866         u32             flav,len;
 867         u32             maj_stat;
 868
 869         dprintk("RPC: %5u gss_validate\n", task->tk_pid);
 870
 871         flav = ntohl(*p++);
 872         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
 873                 goto out_bad;
 874         if (flav != RPC_AUTH_GSS)
 875                 goto out_bad;
 876         seq = htonl(task->tk_rqstp->rq_seqno);
 877         iov.iov_base = &seq;
 878         iov.iov_len = sizeof(seq);
 879         xdr_buf_from_iov(&iov, &verf_buf);
 880         mic.data = (u8 *)p;
 881         mic.len = len;
 882
 883         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 884         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
 885                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 886         if (maj_stat)
 887                 goto out_bad;
 888         /* We leave it to unwrap to calculate au_rslack. For now we just
 889          * calculate the length of the verifier: */
 890         task->tk_auth->au_verfsize = XDR_QUADLEN(len) + 2;
 891         gss_put_ctx(ctx);
 892         dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
 893                         task->tk_pid);
 894         return p + XDR_QUADLEN(len);
 895 out_bad:
 896         gss_put_ctx(ctx);
 897         dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
 898         return NULL;
 899 }
 900
 901 static inline int
 902 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
 903                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
 904 {
 905         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
 906         struct xdr_buf  integ_buf;
 907         __be32          *integ_len = NULL;
 908         struct xdr_netobj mic;
 909         u32             offset;
 910         __be32          *q;
 911         struct kvec     *iov;
 912         u32             maj_stat = 0;
 913         int             status = -EIO;
 914
 915         integ_len = p++;
 916         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
 917         *p++ = htonl(rqstp->rq_seqno);
 918
 919         status = encode(rqstp, p, obj);
 920         if (status)
 921                 return status;
 922
 923         if (xdr_buf_subsegment(snd_buf, &integ_buf,
 924                                 offset, snd_buf->len - offset))
 925                 return status;
 926         *integ_len = htonl(integ_buf.len);
 927
 928         /* guess whether we're in the head or the tail: */
 929         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
 930                 iov = snd_buf->tail;
 931         else
 932                 iov = snd_buf->head;
 933         p = iov->iov_base + iov->iov_len;
 934         mic.data = (u8 *)(p + 1);
 935
 936         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
 937         status = -EIO; /* XXX? */
 938         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
 939                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 940         else if (maj_stat)
 941                 return status;
 942         q = xdr_encode_opaque(p, NULL, mic.len);
 943
 944         offset = (u8 *)q - (u8 *)p;
 945         iov->iov_len += offset;
 946         snd_buf->len += offset;
 947         return 0;
 948 }
 949
 950 static void
 951 priv_release_snd_buf(struct rpc_rqst *rqstp)
 952 {
 953         int i;
 954
 955         for (i=0; i < rqstp->rq_enc_pages_num; i++)
 956                 __free_page(rqstp->rq_enc_pages[i]);
 957         kfree(rqstp->rq_enc_pages);
 958 }
 959
 960 static int
 961 alloc_enc_pages(struct rpc_rqst *rqstp)
 962 {
 963         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
 964         int first, last, i;
 965
 966         if (snd_buf->page_len == 0) {
 967                 rqstp->rq_enc_pages_num = 0;
 968                 return 0;
 969         }
 970
 971         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
 972         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
 973         rqstp->rq_enc_pages_num = last - first + 1 + 1;
 974         rqstp->rq_enc_pages
 975                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
 976                                 GFP_NOFS);
 977         if (!rqstp->rq_enc_pages)
 978                 goto out;
 979         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
 980                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
 981                 if (rqstp->rq_enc_pages[i] == NULL)
 982                         goto out_free;
 983         }
 984         rqstp->rq_release_snd_buf = priv_release_snd_buf;
 985         return 0;
 986 out_free:
 987         for (i--; i >= 0; i--) {
 988                 __free_page(rqstp->rq_enc_pages[i]);
 989         }
 990 out:
 991         return -EAGAIN;
 992 }
 993
 994 static inline int
 995 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
 996                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
 997 {
 998         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
 999         u32             offset;
1000         u32             maj_stat;
1001         int             status;
1002         __be32          *opaque_len;
1003         struct page     **inpages;
1004         int             first;
1005         int             pad;
1006         struct kvec     *iov;
1007         char            *tmp;
1008
1009         opaque_len = p++;
1010         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1011         *p++ = htonl(rqstp->rq_seqno);
1012
1013         status = encode(rqstp, p, obj);
1014         if (status)
1015                 return status;
1016
1017         status = alloc_enc_pages(rqstp);
1018         if (status)
1019                 return status;
1020         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1021         inpages = snd_buf->pages + first;
1022         snd_buf->pages = rqstp->rq_enc_pages;
1023         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1024         /* Give the tail its own page, in case we need extra space in the
1025          * head when wrapping: */
1026         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1027                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1028                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1029                 snd_buf->tail[0].iov_base = tmp;
1030         }
1031         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1032         /* RPC_SLACK_SPACE should prevent this ever happening: */
1033         BUG_ON(snd_buf->len > snd_buf->buflen);
1034         status = -EIO;
1035         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1036          * done anyway, so it's safe to put the request on the wire: */
1037         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1038                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1039         else if (maj_stat)
1040                 return status;
1041
1042         *opaque_len = htonl(snd_buf->len - offset);
1043         /* guess whether we're in the head or the tail: */
1044         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1045                 iov = snd_buf->tail;
1046         else
1047                 iov = snd_buf->head;
1048         p = iov->iov_base + iov->iov_len;
1049         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1050         memset(p, 0, pad);
1051         iov->iov_len += pad;
1052         snd_buf->len += pad;
1053
1054         return 0;
1055 }
1056
1057 static int
1058 gss_wrap_req(struct rpc_task *task,
1059              kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
1060 {
1061         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1062         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1063                         gc_base);
1064         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1065         int             status = -EIO;
1066
1067         dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
1068         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1069                 /* The spec seems a little ambiguous here, but I think that not
1070                  * wrapping context destruction requests makes the most sense.
1071                  */
1072                 status = encode(rqstp, p, obj);
1073                 goto out;
1074         }
1075         switch (gss_cred->gc_service) {
1076                 case RPC_GSS_SVC_NONE:
1077                         status = encode(rqstp, p, obj);
1078                         break;
1079                 case RPC_GSS_SVC_INTEGRITY:
1080                         status = gss_wrap_req_integ(cred, ctx, encode,
1081                                                                 rqstp, p, obj);
1082                         break;
1083                 case RPC_GSS_SVC_PRIVACY:
1084                         status = gss_wrap_req_priv(cred, ctx, encode,
1085                                         rqstp, p, obj);
1086                         break;
1087         }
1088 out:
1089         gss_put_ctx(ctx);
1090         dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
1091         return status;
1092 }
1093
1094 static inline int
1095 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1096                 struct rpc_rqst *rqstp, __be32 **p)
1097 {
1098         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1099         struct xdr_buf integ_buf;
1100         struct xdr_netobj mic;
1101         u32 data_offset, mic_offset;
1102         u32 integ_len;
1103         u32 maj_stat;
1104         int status = -EIO;
1105
1106         integ_len = ntohl(*(*p)++);
1107         if (integ_len & 3)
1108                 return status;
1109         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1110         mic_offset = integ_len + data_offset;
1111         if (mic_offset > rcv_buf->len)
1112                 return status;
1113         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1114                 return status;
1115
1116         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1117                                 mic_offset - data_offset))
1118                 return status;
1119
1120         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1121                 return status;
1122
1123         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1124         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1125                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1126         if (maj_stat != GSS_S_COMPLETE)
1127                 return status;
1128         return 0;
1129 }
1130
1131 static inline int
1132 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1133                 struct rpc_rqst *rqstp, __be32 **p)
1134 {
1135         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1136         u32 offset;
1137         u32 opaque_len;
1138         u32 maj_stat;
1139         int status = -EIO;
1140
1141         opaque_len = ntohl(*(*p)++);
1142         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1143         if (offset + opaque_len > rcv_buf->len)
1144                 return status;
1145         /* remove padding: */
1146         rcv_buf->len = offset + opaque_len;
1147
1148         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1149         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1150                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1151         if (maj_stat != GSS_S_COMPLETE)
1152                 return status;
1153         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1154                 return status;
1155
1156         return 0;
1157 }
1158
1159
1160 static int
1161 gss_unwrap_resp(struct rpc_task *task,
1162                 kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
1163 {
1164         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1165         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1166                         gc_base);
1167         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1168         __be32          *savedp = p;
1169         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1170         int             savedlen = head->iov_len;
1171         int             status = -EIO;
1172
1173         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1174                 goto out_decode;
1175         switch (gss_cred->gc_service) {
1176                 case RPC_GSS_SVC_NONE:
1177                         break;
1178                 case RPC_GSS_SVC_INTEGRITY:
1179                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1180                         if (status)
1181                                 goto out;
1182                         break;
1183                 case RPC_GSS_SVC_PRIVACY:
1184                         status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1185                         if (status)
1186                                 goto out;
1187                         break;
1188         }
1189         /* take into account extra slack for integrity and privacy cases: */
1190         task->tk_auth->au_rslack = task->tk_auth->au_verfsize + (p - savedp)
1191                                                 + (savedlen - head->iov_len);
1192 out_decode:
1193         status = decode(rqstp, p, obj);
1194 out:
1195         gss_put_ctx(ctx);
1196         dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
1197                         status);
1198         return status;
1199 }
1200
1201 static const struct rpc_authops authgss_ops = {
1202         .owner          = THIS_MODULE,
1203         .au_flavor      = RPC_AUTH_GSS,
1204 #ifdef RPC_DEBUG
1205         .au_name        = "RPCSEC_GSS",
1206 #endif
1207         .create         = gss_create,
1208         .destroy        = gss_destroy,
1209         .lookup_cred    = gss_lookup_cred,
1210         .crcreate       = gss_create_cred
1211 };
1212
1213 static const struct rpc_credops gss_credops = {
1214         .cr_name        = "AUTH_GSS",
1215         .crdestroy      = gss_destroy_cred,
1216         .cr_init        = gss_cred_init,
1217         .crmatch        = gss_match,
1218         .crmarshal      = gss_marshal,
1219         .crrefresh      = gss_refresh,
1220         .crvalidate     = gss_validate,
1221         .crwrap_req     = gss_wrap_req,
1222         .crunwrap_resp  = gss_unwrap_resp,
1223 };
1224
1225 static struct rpc_pipe_ops gss_upcall_ops = {
1226         .upcall         = gss_pipe_upcall,
1227         .downcall       = gss_pipe_downcall,
1228         .destroy_msg    = gss_pipe_destroy_msg,
1229         .release_pipe   = gss_pipe_release,
1230 };
1231
1232 /*
1233  * Initialize RPCSEC_GSS module
1234  */
1235 static int __init init_rpcsec_gss(void)
1236 {
1237         int err = 0;
1238
1239         err = rpcauth_register(&authgss_ops);
1240         if (err)
1241                 goto out;
1242         err = gss_svc_init();
1243         if (err)
1244                 goto out_unregister;
1245         return 0;
1246 out_unregister:
1247         rpcauth_unregister(&authgss_ops);
1248 out:
1249         return err;
1250 }
1251
1252 static void __exit exit_rpcsec_gss(void)
1253 {
1254         gss_svc_shutdown();
1255         rpcauth_unregister(&authgss_ops);
1256 }
1257
1258 MODULE_LICENSE("GPL");
1259 module_init(init_rpcsec_gss)
1260 module_exit(exit_rpcsec_gss)