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   1 /*
   2  * linux/net/sunrpc/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 struct rpc_authops authgss_ops;
  58
  59 static 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_EXPIRE         (60 * HZ)       /* XXX: reasonable? */
  68 #define GSS_CRED_SLACK          1024            /* XXX: unused */
  69 /* length of a krb5 verifier (48), plus data added before arguments when
  70  * using integrity (two 4-byte integers): */
  71 #define GSS_VERF_SLACK          56
  72
  73 /* XXX this define must match the gssd define
  74 * as it is passed to gssd to signal the use of
  75 * machine creds should be part of the shared rpc interface */
  76
  77 #define CA_RUN_AS_MACHINE  0x00000200
  78
  79 /* dump the buffer in `emacs-hexl' style */
  80 #define isprint(c)      ((c > 0x1f) && (c < 0x7f))
  81
  82 static DEFINE_RWLOCK(gss_ctx_lock);
  83
  84 struct gss_auth {
  85         struct rpc_auth rpc_auth;
  86         struct gss_api_mech *mech;
  87         enum rpc_gss_svc service;
  88         struct list_head upcalls;
  89         struct rpc_clnt *client;
  90         struct dentry *dentry;
  91         char path[48];
  92         spinlock_t lock;
  93 };
  94
  95 static void gss_destroy_ctx(struct gss_cl_ctx *);
  96 static struct rpc_pipe_ops gss_upcall_ops;
  97
  98 void
  99 print_hexl(u32 *p, u_int length, u_int offset)
 100 {
 101         u_int i, j, jm;
 102         u8 c, *cp;
 103
 104         dprintk("RPC: print_hexl: length %d\n",length);
 105         dprintk("\n");
 106         cp = (u8 *) p;
 107
 108         for (i = 0; i < length; i += 0x10) {
 109                 dprintk("  %04x: ", (u_int)(i + offset));
 110                 jm = length - i;
 111                 jm = jm > 16 ? 16 : jm;
 112
 113                 for (j = 0; j < jm; j++) {
 114                         if ((j % 2) == 1)
 115                                 dprintk("%02x ", (u_int)cp[i+j]);
 116                         else
 117                                 dprintk("%02x", (u_int)cp[i+j]);
 118                 }
 119                 for (; j < 16; j++) {
 120                         if ((j % 2) == 1)
 121                                 dprintk("   ");
 122                         else
 123                                 dprintk("  ");
 124                 }
 125                 dprintk(" ");
 126
 127                 for (j = 0; j < jm; j++) {
 128                         c = cp[i+j];
 129                         c = isprint(c) ? c : '.';
 130                         dprintk("%c", c);
 131                 }
 132                 dprintk("\n");
 133         }
 134 }
 135
 136 EXPORT_SYMBOL(print_hexl);
 137
 138 static inline struct gss_cl_ctx *
 139 gss_get_ctx(struct gss_cl_ctx *ctx)
 140 {
 141         atomic_inc(&ctx->count);
 142         return ctx;
 143 }
 144
 145 static inline void
 146 gss_put_ctx(struct gss_cl_ctx *ctx)
 147 {
 148         if (atomic_dec_and_test(&ctx->count))
 149                 gss_destroy_ctx(ctx);
 150 }
 151
 152 static void
 153 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 154 {
 155         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 156         struct gss_cl_ctx *old;
 157         write_lock(&gss_ctx_lock);
 158         old = gss_cred->gc_ctx;
 159         gss_cred->gc_ctx = ctx;
 160         cred->cr_flags |= RPCAUTH_CRED_UPTODATE;
 161         cred->cr_flags &= ~RPCAUTH_CRED_NEW;
 162         write_unlock(&gss_ctx_lock);
 163         if (old)
 164                 gss_put_ctx(old);
 165 }
 166
 167 static int
 168 gss_cred_is_uptodate_ctx(struct rpc_cred *cred)
 169 {
 170         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 171         int res = 0;
 172
 173         read_lock(&gss_ctx_lock);
 174         if ((cred->cr_flags & RPCAUTH_CRED_UPTODATE) && gss_cred->gc_ctx)
 175                 res = 1;
 176         read_unlock(&gss_ctx_lock);
 177         return res;
 178 }
 179
 180 static const void *
 181 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 182 {
 183         const void *q = (const void *)((const char *)p + len);
 184         if (unlikely(q > end || q < p))
 185                 return ERR_PTR(-EFAULT);
 186         memcpy(res, p, len);
 187         return q;
 188 }
 189
 190 static inline const void *
 191 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 192 {
 193         const void *q;
 194         unsigned int len;
 195
 196         p = simple_get_bytes(p, end, &len, sizeof(len));
 197         if (IS_ERR(p))
 198                 return p;
 199         q = (const void *)((const char *)p + len);
 200         if (unlikely(q > end || q < p))
 201                 return ERR_PTR(-EFAULT);
 202         dest->data = kmalloc(len, GFP_KERNEL);
 203         if (unlikely(dest->data == NULL))
 204                 return ERR_PTR(-ENOMEM);
 205         dest->len = len;
 206         memcpy(dest->data, p, len);
 207         return q;
 208 }
 209
 210 static struct gss_cl_ctx *
 211 gss_cred_get_ctx(struct rpc_cred *cred)
 212 {
 213         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 214         struct gss_cl_ctx *ctx = NULL;
 215
 216         read_lock(&gss_ctx_lock);
 217         if (gss_cred->gc_ctx)
 218                 ctx = gss_get_ctx(gss_cred->gc_ctx);
 219         read_unlock(&gss_ctx_lock);
 220         return ctx;
 221 }
 222
 223 static struct gss_cl_ctx *
 224 gss_alloc_context(void)
 225 {
 226         struct gss_cl_ctx *ctx;
 227
 228         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 229         if (ctx != NULL) {
 230                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 231                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 232                 spin_lock_init(&ctx->gc_seq_lock);
 233                 atomic_set(&ctx->count,1);
 234         }
 235         return ctx;
 236 }
 237
 238 #define GSSD_MIN_TIMEOUT (60 * 60)
 239 static const void *
 240 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 241 {
 242         const void *q;
 243         unsigned int seclen;
 244         unsigned int timeout;
 245         u32 window_size;
 246         int ret;
 247
 248         /* First unsigned int gives the lifetime (in seconds) of the cred */
 249         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 250         if (IS_ERR(p))
 251                 goto err;
 252         if (timeout == 0)
 253                 timeout = GSSD_MIN_TIMEOUT;
 254         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
 255         /* Sequence number window. Determines the maximum number of simultaneous requests */
 256         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 257         if (IS_ERR(p))
 258                 goto err;
 259         ctx->gc_win = window_size;
 260         /* gssd signals an error by passing ctx->gc_win = 0: */
 261         if (ctx->gc_win == 0) {
 262                 /* in which case, p points to  an error code which we ignore */
 263                 p = ERR_PTR(-EACCES);
 264                 goto err;
 265         }
 266         /* copy the opaque wire context */
 267         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 268         if (IS_ERR(p))
 269                 goto err;
 270         /* import the opaque security context */
 271         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 272         if (IS_ERR(p))
 273                 goto err;
 274         q = (const void *)((const char *)p + seclen);
 275         if (unlikely(q > end || q < p)) {
 276                 p = ERR_PTR(-EFAULT);
 277                 goto err;
 278         }
 279         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
 280         if (ret < 0) {
 281                 p = ERR_PTR(ret);
 282                 goto err;
 283         }
 284         return q;
 285 err:
 286         dprintk("RPC:      gss_fill_context returning %ld\n", -PTR_ERR(p));
 287         return p;
 288 }
 289
 290
 291 struct gss_upcall_msg {
 292         atomic_t count;
 293         uid_t   uid;
 294         struct rpc_pipe_msg msg;
 295         struct list_head list;
 296         struct gss_auth *auth;
 297         struct rpc_wait_queue rpc_waitqueue;
 298         wait_queue_head_t waitqueue;
 299         struct gss_cl_ctx *ctx;
 300 };
 301
 302 static void
 303 gss_release_msg(struct gss_upcall_msg *gss_msg)
 304 {
 305         if (!atomic_dec_and_test(&gss_msg->count))
 306                 return;
 307         BUG_ON(!list_empty(&gss_msg->list));
 308         if (gss_msg->ctx != NULL)
 309                 gss_put_ctx(gss_msg->ctx);
 310         kfree(gss_msg);
 311 }
 312
 313 static struct gss_upcall_msg *
 314 __gss_find_upcall(struct gss_auth *gss_auth, uid_t uid)
 315 {
 316         struct gss_upcall_msg *pos;
 317         list_for_each_entry(pos, &gss_auth->upcalls, list) {
 318                 if (pos->uid != uid)
 319                         continue;
 320                 atomic_inc(&pos->count);
 321                 dprintk("RPC:      gss_find_upcall found msg %p\n", pos);
 322                 return pos;
 323         }
 324         dprintk("RPC:      gss_find_upcall found nothing\n");
 325         return NULL;
 326 }
 327
 328 /* Try to add a upcall to the pipefs queue.
 329  * If an upcall owned by our uid already exists, then we return a reference
 330  * to that upcall instead of adding the new upcall.
 331  */
 332 static inline struct gss_upcall_msg *
 333 gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
 334 {
 335         struct gss_upcall_msg *old;
 336
 337         spin_lock(&gss_auth->lock);
 338         old = __gss_find_upcall(gss_auth, gss_msg->uid);
 339         if (old == NULL) {
 340                 atomic_inc(&gss_msg->count);
 341                 list_add(&gss_msg->list, &gss_auth->upcalls);
 342         } else
 343                 gss_msg = old;
 344         spin_unlock(&gss_auth->lock);
 345         return gss_msg;
 346 }
 347
 348 static void
 349 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 350 {
 351         if (list_empty(&gss_msg->list))
 352                 return;
 353         list_del_init(&gss_msg->list);
 354         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 355         wake_up_all(&gss_msg->waitqueue);
 356         atomic_dec(&gss_msg->count);
 357 }
 358
 359 static void
 360 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 361 {
 362         struct gss_auth *gss_auth = gss_msg->auth;
 363
 364         spin_lock(&gss_auth->lock);
 365         __gss_unhash_msg(gss_msg);
 366         spin_unlock(&gss_auth->lock);
 367 }
 368
 369 static void
 370 gss_upcall_callback(struct rpc_task *task)
 371 {
 372         struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
 373                         struct gss_cred, gc_base);
 374         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 375
 376         BUG_ON(gss_msg == NULL);
 377         if (gss_msg->ctx)
 378                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_get_ctx(gss_msg->ctx));
 379         else
 380                 task->tk_status = gss_msg->msg.errno;
 381         spin_lock(&gss_msg->auth->lock);
 382         gss_cred->gc_upcall = NULL;
 383         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 384         spin_unlock(&gss_msg->auth->lock);
 385         gss_release_msg(gss_msg);
 386 }
 387
 388 static inline struct gss_upcall_msg *
 389 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid)
 390 {
 391         struct gss_upcall_msg *gss_msg;
 392
 393         gss_msg = kzalloc(sizeof(*gss_msg), GFP_KERNEL);
 394         if (gss_msg != NULL) {
 395                 INIT_LIST_HEAD(&gss_msg->list);
 396                 rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 397                 init_waitqueue_head(&gss_msg->waitqueue);
 398                 atomic_set(&gss_msg->count, 1);
 399                 gss_msg->msg.data = &gss_msg->uid;
 400                 gss_msg->msg.len = sizeof(gss_msg->uid);
 401                 gss_msg->uid = uid;
 402                 gss_msg->auth = gss_auth;
 403         }
 404         return gss_msg;
 405 }
 406
 407 static struct gss_upcall_msg *
 408 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
 409 {
 410         struct gss_upcall_msg *gss_new, *gss_msg;
 411
 412         gss_new = gss_alloc_msg(gss_auth, cred->cr_uid);
 413         if (gss_new == NULL)
 414                 return ERR_PTR(-ENOMEM);
 415         gss_msg = gss_add_msg(gss_auth, gss_new);
 416         if (gss_msg == gss_new) {
 417                 int res = rpc_queue_upcall(gss_auth->dentry->d_inode, &gss_new->msg);
 418                 if (res) {
 419                         gss_unhash_msg(gss_new);
 420                         gss_msg = ERR_PTR(res);
 421                 }
 422         } else
 423                 gss_release_msg(gss_new);
 424         return gss_msg;
 425 }
 426
 427 static inline int
 428 gss_refresh_upcall(struct rpc_task *task)
 429 {
 430         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 431         struct gss_auth *gss_auth = container_of(task->tk_client->cl_auth,
 432                         struct gss_auth, rpc_auth);
 433         struct gss_cred *gss_cred = container_of(cred,
 434                         struct gss_cred, gc_base);
 435         struct gss_upcall_msg *gss_msg;
 436         int err = 0;
 437
 438         dprintk("RPC: %4u gss_refresh_upcall for uid %u\n", task->tk_pid, cred->cr_uid);
 439         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
 440         if (IS_ERR(gss_msg)) {
 441                 err = PTR_ERR(gss_msg);
 442                 goto out;
 443         }
 444         spin_lock(&gss_auth->lock);
 445         if (gss_cred->gc_upcall != NULL)
 446                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL, NULL);
 447         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 448                 task->tk_timeout = 0;
 449                 gss_cred->gc_upcall = gss_msg;
 450                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 451                 atomic_inc(&gss_msg->count);
 452                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback, NULL);
 453         } else
 454                 err = gss_msg->msg.errno;
 455         spin_unlock(&gss_auth->lock);
 456         gss_release_msg(gss_msg);
 457 out:
 458         dprintk("RPC: %4u gss_refresh_upcall for uid %u result %d\n", task->tk_pid,
 459                         cred->cr_uid, err);
 460         return err;
 461 }
 462
 463 static inline int
 464 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 465 {
 466         struct rpc_cred *cred = &gss_cred->gc_base;
 467         struct gss_upcall_msg *gss_msg;
 468         DEFINE_WAIT(wait);
 469         int err = 0;
 470
 471         dprintk("RPC: gss_upcall for uid %u\n", cred->cr_uid);
 472         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 473         if (IS_ERR(gss_msg)) {
 474                 err = PTR_ERR(gss_msg);
 475                 goto out;
 476         }
 477         for (;;) {
 478                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
 479                 spin_lock(&gss_auth->lock);
 480                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 481                         spin_unlock(&gss_auth->lock);
 482                         break;
 483                 }
 484                 spin_unlock(&gss_auth->lock);
 485                 if (signalled()) {
 486                         err = -ERESTARTSYS;
 487                         goto out_intr;
 488                 }
 489                 schedule();
 490         }
 491         if (gss_msg->ctx)
 492                 gss_cred_set_ctx(cred, gss_get_ctx(gss_msg->ctx));
 493         else
 494                 err = gss_msg->msg.errno;
 495 out_intr:
 496         finish_wait(&gss_msg->waitqueue, &wait);
 497         gss_release_msg(gss_msg);
 498 out:
 499         dprintk("RPC: gss_create_upcall for uid %u result %d\n", cred->cr_uid, err);
 500         return err;
 501 }
 502
 503 static ssize_t
 504 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 505                 char __user *dst, size_t buflen)
 506 {
 507         char *data = (char *)msg->data + msg->copied;
 508         ssize_t mlen = msg->len;
 509         ssize_t left;
 510
 511         if (mlen > buflen)
 512                 mlen = buflen;
 513         left = copy_to_user(dst, data, mlen);
 514         if (left < 0) {
 515                 msg->errno = left;
 516                 return left;
 517         }
 518         mlen -= left;
 519         msg->copied += mlen;
 520         msg->errno = 0;
 521         return mlen;
 522 }
 523
 524 #define MSG_BUF_MAXSIZE 1024
 525
 526 static ssize_t
 527 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 528 {
 529         const void *p, *end;
 530         void *buf;
 531         struct rpc_clnt *clnt;
 532         struct gss_auth *gss_auth;
 533         struct rpc_cred *cred;
 534         struct gss_upcall_msg *gss_msg;
 535         struct gss_cl_ctx *ctx;
 536         uid_t uid;
 537         int err = -EFBIG;
 538
 539         if (mlen > MSG_BUF_MAXSIZE)
 540                 goto out;
 541         err = -ENOMEM;
 542         buf = kmalloc(mlen, GFP_KERNEL);
 543         if (!buf)
 544                 goto out;
 545
 546         clnt = RPC_I(filp->f_dentry->d_inode)->private;
 547         err = -EFAULT;
 548         if (copy_from_user(buf, src, mlen))
 549                 goto err;
 550
 551         end = (const void *)((char *)buf + mlen);
 552         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
 553         if (IS_ERR(p)) {
 554                 err = PTR_ERR(p);
 555                 goto err;
 556         }
 557
 558         err = -ENOMEM;
 559         ctx = gss_alloc_context();
 560         if (ctx == NULL)
 561                 goto err;
 562         err = 0;
 563         gss_auth = container_of(clnt->cl_auth, struct gss_auth, rpc_auth);
 564         p = gss_fill_context(p, end, ctx, gss_auth->mech);
 565         if (IS_ERR(p)) {
 566                 err = PTR_ERR(p);
 567                 if (err != -EACCES)
 568                         goto err_put_ctx;
 569         }
 570         spin_lock(&gss_auth->lock);
 571         gss_msg = __gss_find_upcall(gss_auth, uid);
 572         if (gss_msg) {
 573                 if (err == 0 && gss_msg->ctx == NULL)
 574                         gss_msg->ctx = gss_get_ctx(ctx);
 575                 gss_msg->msg.errno = err;
 576                 __gss_unhash_msg(gss_msg);
 577                 spin_unlock(&gss_auth->lock);
 578                 gss_release_msg(gss_msg);
 579         } else {
 580                 struct auth_cred acred = { .uid = uid };
 581                 spin_unlock(&gss_auth->lock);
 582                 cred = rpcauth_lookup_credcache(clnt->cl_auth, &acred, RPCAUTH_LOOKUP_NEW);
 583                 if (IS_ERR(cred)) {
 584                         err = PTR_ERR(cred);
 585                         goto err_put_ctx;
 586                 }
 587                 gss_cred_set_ctx(cred, gss_get_ctx(ctx));
 588         }
 589         gss_put_ctx(ctx);
 590         kfree(buf);
 591         dprintk("RPC:      gss_pipe_downcall returning length %Zu\n", mlen);
 592         return mlen;
 593 err_put_ctx:
 594         gss_put_ctx(ctx);
 595 err:
 596         kfree(buf);
 597 out:
 598         dprintk("RPC:      gss_pipe_downcall returning %d\n", err);
 599         return err;
 600 }
 601
 602 static void
 603 gss_pipe_release(struct inode *inode)
 604 {
 605         struct rpc_inode *rpci = RPC_I(inode);
 606         struct rpc_clnt *clnt;
 607         struct rpc_auth *auth;
 608         struct gss_auth *gss_auth;
 609
 610         clnt = rpci->private;
 611         auth = clnt->cl_auth;
 612         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 613         spin_lock(&gss_auth->lock);
 614         while (!list_empty(&gss_auth->upcalls)) {
 615                 struct gss_upcall_msg *gss_msg;
 616
 617                 gss_msg = list_entry(gss_auth->upcalls.next,
 618                                 struct gss_upcall_msg, list);
 619                 gss_msg->msg.errno = -EPIPE;
 620                 atomic_inc(&gss_msg->count);
 621                 __gss_unhash_msg(gss_msg);
 622                 spin_unlock(&gss_auth->lock);
 623                 gss_release_msg(gss_msg);
 624                 spin_lock(&gss_auth->lock);
 625         }
 626         spin_unlock(&gss_auth->lock);
 627 }
 628
 629 static void
 630 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 631 {
 632         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 633         static unsigned long ratelimit;
 634
 635         if (msg->errno < 0) {
 636                 dprintk("RPC:      gss_pipe_destroy_msg releasing msg %p\n",
 637                                 gss_msg);
 638                 atomic_inc(&gss_msg->count);
 639                 gss_unhash_msg(gss_msg);
 640                 if (msg->errno == -ETIMEDOUT) {
 641                         unsigned long now = jiffies;
 642                         if (time_after(now, ratelimit)) {
 643                                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 644                                                     "Please check user daemon is running!\n");
 645                                 ratelimit = now + 15*HZ;
 646                         }
 647                 }
 648                 gss_release_msg(gss_msg);
 649         }
 650 }
 651
 652 /*
 653  * NOTE: we have the opportunity to use different
 654  * parameters based on the input flavor (which must be a pseudoflavor)
 655  */
 656 static struct rpc_auth *
 657 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 658 {
 659         struct gss_auth *gss_auth;
 660         struct rpc_auth * auth;
 661         int err = -ENOMEM; /* XXX? */
 662
 663         dprintk("RPC:      creating GSS authenticator for client %p\n",clnt);
 664
 665         if (!try_module_get(THIS_MODULE))
 666                 return ERR_PTR(err);
 667         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 668                 goto out_dec;
 669         gss_auth->client = clnt;
 670         err = -EINVAL;
 671         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 672         if (!gss_auth->mech) {
 673                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!",
 674                                 __FUNCTION__, flavor);
 675                 goto err_free;
 676         }
 677         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 678         if (gss_auth->service == 0)
 679                 goto err_put_mech;
 680         INIT_LIST_HEAD(&gss_auth->upcalls);
 681         spin_lock_init(&gss_auth->lock);
 682         auth = &gss_auth->rpc_auth;
 683         auth->au_cslack = GSS_CRED_SLACK >> 2;
 684         auth->au_rslack = GSS_VERF_SLACK >> 2;
 685         auth->au_ops = &authgss_ops;
 686         auth->au_flavor = flavor;
 687         atomic_set(&auth->au_count, 1);
 688
 689         err = rpcauth_init_credcache(auth, GSS_CRED_EXPIRE);
 690         if (err)
 691                 goto err_put_mech;
 692
 693         snprintf(gss_auth->path, sizeof(gss_auth->path), "%s/%s",
 694                         clnt->cl_pathname,
 695                         gss_auth->mech->gm_name);
 696         gss_auth->dentry = rpc_mkpipe(gss_auth->path, clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 697         if (IS_ERR(gss_auth->dentry)) {
 698                 err = PTR_ERR(gss_auth->dentry);
 699                 goto err_put_mech;
 700         }
 701
 702         return auth;
 703 err_put_mech:
 704         gss_mech_put(gss_auth->mech);
 705 err_free:
 706         kfree(gss_auth);
 707 out_dec:
 708         module_put(THIS_MODULE);
 709         return ERR_PTR(err);
 710 }
 711
 712 static void
 713 gss_destroy(struct rpc_auth *auth)
 714 {
 715         struct gss_auth *gss_auth;
 716
 717         dprintk("RPC:      destroying GSS authenticator %p flavor %d\n",
 718                 auth, auth->au_flavor);
 719
 720         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 721         rpc_unlink(gss_auth->dentry);
 722         dput(gss_auth->dentry);
 723         gss_auth->dentry = NULL;
 724         gss_mech_put(gss_auth->mech);
 725
 726         rpcauth_free_credcache(auth);
 727         kfree(gss_auth);
 728         module_put(THIS_MODULE);
 729 }
 730
 731 /* gss_destroy_cred (and gss_destroy_ctx) are used to clean up after failure
 732  * to create a new cred or context, so they check that things have been
 733  * allocated before freeing them. */
 734 static void
 735 gss_destroy_ctx(struct gss_cl_ctx *ctx)
 736 {
 737         dprintk("RPC:      gss_destroy_ctx\n");
 738
 739         if (ctx->gc_gss_ctx)
 740                 gss_delete_sec_context(&ctx->gc_gss_ctx);
 741
 742         kfree(ctx->gc_wire_ctx.data);
 743         kfree(ctx);
 744 }
 745
 746 static void
 747 gss_destroy_cred(struct rpc_cred *rc)
 748 {
 749         struct gss_cred *cred = container_of(rc, struct gss_cred, gc_base);
 750
 751         dprintk("RPC:      gss_destroy_cred \n");
 752
 753         if (cred->gc_ctx)
 754                 gss_put_ctx(cred->gc_ctx);
 755         kfree(cred);
 756 }
 757
 758 /*
 759  * Lookup RPCSEC_GSS cred for the current process
 760  */
 761 static struct rpc_cred *
 762 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 763 {
 764         return rpcauth_lookup_credcache(auth, acred, flags);
 765 }
 766
 767 static struct rpc_cred *
 768 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 769 {
 770         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 771         struct gss_cred *cred = NULL;
 772         int err = -ENOMEM;
 773
 774         dprintk("RPC:      gss_create_cred for uid %d, flavor %d\n",
 775                 acred->uid, auth->au_flavor);
 776
 777         if (!(cred = kzalloc(sizeof(*cred), GFP_KERNEL)))
 778                 goto out_err;
 779
 780         atomic_set(&cred->gc_count, 1);
 781         cred->gc_uid = acred->uid;
 782         /*
 783          * Note: in order to force a call to call_refresh(), we deliberately
 784          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
 785          */
 786         cred->gc_flags = 0;
 787         cred->gc_base.cr_ops = &gss_credops;
 788         cred->gc_base.cr_flags = RPCAUTH_CRED_NEW;
 789         cred->gc_service = gss_auth->service;
 790         return &cred->gc_base;
 791
 792 out_err:
 793         dprintk("RPC:      gss_create_cred failed with error %d\n", err);
 794         return ERR_PTR(err);
 795 }
 796
 797 static int
 798 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
 799 {
 800         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 801         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
 802         int err;
 803
 804         do {
 805                 err = gss_create_upcall(gss_auth, gss_cred);
 806         } while (err == -EAGAIN);
 807         return err;
 808 }
 809
 810 static int
 811 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
 812 {
 813         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
 814
 815         /*
 816          * If the searchflags have set RPCAUTH_LOOKUP_NEW, then
 817          * we don't really care if the credential has expired or not,
 818          * since the caller should be prepared to reinitialise it.
 819          */
 820         if ((flags & RPCAUTH_LOOKUP_NEW) && (rc->cr_flags & RPCAUTH_CRED_NEW))
 821                 goto out;
 822         /* Don't match with creds that have expired. */
 823         if (gss_cred->gc_ctx && time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
 824                 return 0;
 825 out:
 826         return (rc->cr_uid == acred->uid);
 827 }
 828
 829 /*
 830 * Marshal credentials.
 831 * Maybe we should keep a cached credential for performance reasons.
 832 */
 833 static u32 *
 834 gss_marshal(struct rpc_task *task, u32 *p)
 835 {
 836         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 837         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
 838                                                  gc_base);
 839         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
 840         u32             *cred_len;
 841         struct rpc_rqst *req = task->tk_rqstp;
 842         u32             maj_stat = 0;
 843         struct xdr_netobj mic;
 844         struct kvec     iov;
 845         struct xdr_buf  verf_buf;
 846
 847         dprintk("RPC: %4u gss_marshal\n", task->tk_pid);
 848
 849         *p++ = htonl(RPC_AUTH_GSS);
 850         cred_len = p++;
 851
 852         spin_lock(&ctx->gc_seq_lock);
 853         req->rq_seqno = ctx->gc_seq++;
 854         spin_unlock(&ctx->gc_seq_lock);
 855
 856         *p++ = htonl((u32) RPC_GSS_VERSION);
 857         *p++ = htonl((u32) ctx->gc_proc);
 858         *p++ = htonl((u32) req->rq_seqno);
 859         *p++ = htonl((u32) gss_cred->gc_service);
 860         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
 861         *cred_len = htonl((p - (cred_len + 1)) << 2);
 862
 863         /* We compute the checksum for the verifier over the xdr-encoded bytes
 864          * starting with the xid and ending at the end of the credential: */
 865         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
 866                                         req->rq_snd_buf.head[0].iov_base);
 867         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
 868         xdr_buf_from_iov(&iov, &verf_buf);
 869
 870         /* set verifier flavor*/
 871         *p++ = htonl(RPC_AUTH_GSS);
 872
 873         mic.data = (u8 *)(p + 1);
 874         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 875         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
 876                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
 877         } else if (maj_stat != 0) {
 878                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
 879                 goto out_put_ctx;
 880         }
 881         p = xdr_encode_opaque(p, NULL, mic.len);
 882         gss_put_ctx(ctx);
 883         return p;
 884 out_put_ctx:
 885         gss_put_ctx(ctx);
 886         return NULL;
 887 }
 888
 889 /*
 890 * Refresh credentials. XXX - finish
 891 */
 892 static int
 893 gss_refresh(struct rpc_task *task)
 894 {
 895
 896         if (!gss_cred_is_uptodate_ctx(task->tk_msg.rpc_cred))
 897                 return gss_refresh_upcall(task);
 898         return 0;
 899 }
 900
 901 static u32 *
 902 gss_validate(struct rpc_task *task, u32 *p)
 903 {
 904         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 905         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
 906         u32             seq;
 907         struct kvec     iov;
 908         struct xdr_buf  verf_buf;
 909         struct xdr_netobj mic;
 910         u32             flav,len;
 911         u32             maj_stat;
 912
 913         dprintk("RPC: %4u gss_validate\n", task->tk_pid);
 914
 915         flav = ntohl(*p++);
 916         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
 917                 goto out_bad;
 918         if (flav != RPC_AUTH_GSS)
 919                 goto out_bad;
 920         seq = htonl(task->tk_rqstp->rq_seqno);
 921         iov.iov_base = &seq;
 922         iov.iov_len = sizeof(seq);
 923         xdr_buf_from_iov(&iov, &verf_buf);
 924         mic.data = (u8 *)p;
 925         mic.len = len;
 926
 927         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 928         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
 929                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
 930         if (maj_stat)
 931                 goto out_bad;
 932         /* We leave it to unwrap to calculate au_rslack. For now we just
 933          * calculate the length of the verifier: */
 934         task->tk_auth->au_verfsize = XDR_QUADLEN(len) + 2;
 935         gss_put_ctx(ctx);
 936         dprintk("RPC: %4u GSS gss_validate: gss_verify_mic succeeded.\n",
 937                         task->tk_pid);
 938         return p + XDR_QUADLEN(len);
 939 out_bad:
 940         gss_put_ctx(ctx);
 941         dprintk("RPC: %4u gss_validate failed.\n", task->tk_pid);
 942         return NULL;
 943 }
 944
 945 static inline int
 946 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
 947                 kxdrproc_t encode, struct rpc_rqst *rqstp, u32 *p, void *obj)
 948 {
 949         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
 950         struct xdr_buf  integ_buf;
 951         u32             *integ_len = NULL;
 952         struct xdr_netobj mic;
 953         u32             offset, *q;
 954         struct kvec     *iov;
 955         u32             maj_stat = 0;
 956         int             status = -EIO;
 957
 958         integ_len = p++;
 959         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
 960         *p++ = htonl(rqstp->rq_seqno);
 961
 962         status = encode(rqstp, p, obj);
 963         if (status)
 964                 return status;
 965
 966         if (xdr_buf_subsegment(snd_buf, &integ_buf,
 967                                 offset, snd_buf->len - offset))
 968                 return status;
 969         *integ_len = htonl(integ_buf.len);
 970
 971         /* guess whether we're in the head or the tail: */
 972         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
 973                 iov = snd_buf->tail;
 974         else
 975                 iov = snd_buf->head;
 976         p = iov->iov_base + iov->iov_len;
 977         mic.data = (u8 *)(p + 1);
 978
 979         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
 980         status = -EIO; /* XXX? */
 981         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
 982                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
 983         else if (maj_stat)
 984                 return status;
 985         q = xdr_encode_opaque(p, NULL, mic.len);
 986
 987         offset = (u8 *)q - (u8 *)p;
 988         iov->iov_len += offset;
 989         snd_buf->len += offset;
 990         return 0;
 991 }
 992
 993 static void
 994 priv_release_snd_buf(struct rpc_rqst *rqstp)
 995 {
 996         int i;
 997
 998         for (i=0; i < rqstp->rq_enc_pages_num; i++)
 999                 __free_page(rqstp->rq_enc_pages[i]);
1000         kfree(rqstp->rq_enc_pages);
1001 }
1002
1003 static int
1004 alloc_enc_pages(struct rpc_rqst *rqstp)
1005 {
1006         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1007         int first, last, i;
1008
1009         if (snd_buf->page_len == 0) {
1010                 rqstp->rq_enc_pages_num = 0;
1011                 return 0;
1012         }
1013
1014         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1015         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1016         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1017         rqstp->rq_enc_pages
1018                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1019                                 GFP_NOFS);
1020         if (!rqstp->rq_enc_pages)
1021                 goto out;
1022         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1023                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1024                 if (rqstp->rq_enc_pages[i] == NULL)
1025                         goto out_free;
1026         }
1027         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1028         return 0;
1029 out_free:
1030         for (i--; i >= 0; i--) {
1031                 __free_page(rqstp->rq_enc_pages[i]);
1032         }
1033 out:
1034         return -EAGAIN;
1035 }
1036
1037 static inline int
1038 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1039                 kxdrproc_t encode, struct rpc_rqst *rqstp, u32 *p, void *obj)
1040 {
1041         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1042         u32             offset;
1043         u32             maj_stat;
1044         int             status;
1045         u32             *opaque_len;
1046         struct page     **inpages;
1047         int             first;
1048         int             pad;
1049         struct kvec     *iov;
1050         char            *tmp;
1051
1052         opaque_len = p++;
1053         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1054         *p++ = htonl(rqstp->rq_seqno);
1055
1056         status = encode(rqstp, p, obj);
1057         if (status)
1058                 return status;
1059
1060         status = alloc_enc_pages(rqstp);
1061         if (status)
1062                 return status;
1063         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1064         inpages = snd_buf->pages + first;
1065         snd_buf->pages = rqstp->rq_enc_pages;
1066         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1067         /* Give the tail its own page, in case we need extra space in the
1068          * head when wrapping: */
1069         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1070                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1071                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1072                 snd_buf->tail[0].iov_base = tmp;
1073         }
1074         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1075         /* RPC_SLACK_SPACE should prevent this ever happening: */
1076         BUG_ON(snd_buf->len > snd_buf->buflen);
1077         status = -EIO;
1078         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1079          * done anyway, so it's safe to put the request on the wire: */
1080         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1081                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
1082         else if (maj_stat)
1083                 return status;
1084
1085         *opaque_len = htonl(snd_buf->len - offset);
1086         /* guess whether we're in the head or the tail: */
1087         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1088                 iov = snd_buf->tail;
1089         else
1090                 iov = snd_buf->head;
1091         p = iov->iov_base + iov->iov_len;
1092         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1093         memset(p, 0, pad);
1094         iov->iov_len += pad;
1095         snd_buf->len += pad;
1096
1097         return 0;
1098 }
1099
1100 static int
1101 gss_wrap_req(struct rpc_task *task,
1102              kxdrproc_t encode, void *rqstp, u32 *p, void *obj)
1103 {
1104         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1105         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1106                         gc_base);
1107         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1108         int             status = -EIO;
1109
1110         dprintk("RPC: %4u gss_wrap_req\n", task->tk_pid);
1111         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1112                 /* The spec seems a little ambiguous here, but I think that not
1113                  * wrapping context destruction requests makes the most sense.
1114                  */
1115                 status = encode(rqstp, p, obj);
1116                 goto out;
1117         }
1118         switch (gss_cred->gc_service) {
1119                 case RPC_GSS_SVC_NONE:
1120                         status = encode(rqstp, p, obj);
1121                         break;
1122                 case RPC_GSS_SVC_INTEGRITY:
1123                         status = gss_wrap_req_integ(cred, ctx, encode,
1124                                                                 rqstp, p, obj);
1125                         break;
1126                 case RPC_GSS_SVC_PRIVACY:
1127                         status = gss_wrap_req_priv(cred, ctx, encode,
1128                                         rqstp, p, obj);
1129                         break;
1130         }
1131 out:
1132         gss_put_ctx(ctx);
1133         dprintk("RPC: %4u gss_wrap_req returning %d\n", task->tk_pid, status);
1134         return status;
1135 }
1136
1137 static inline int
1138 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1139                 struct rpc_rqst *rqstp, u32 **p)
1140 {
1141         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1142         struct xdr_buf integ_buf;
1143         struct xdr_netobj mic;
1144         u32 data_offset, mic_offset;
1145         u32 integ_len;
1146         u32 maj_stat;
1147         int status = -EIO;
1148
1149         integ_len = ntohl(*(*p)++);
1150         if (integ_len & 3)
1151                 return status;
1152         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1153         mic_offset = integ_len + data_offset;
1154         if (mic_offset > rcv_buf->len)
1155                 return status;
1156         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1157                 return status;
1158
1159         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1160                                 mic_offset - data_offset))
1161                 return status;
1162
1163         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1164                 return status;
1165
1166         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1167         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1168                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
1169         if (maj_stat != GSS_S_COMPLETE)
1170                 return status;
1171         return 0;
1172 }
1173
1174 static inline int
1175 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1176                 struct rpc_rqst *rqstp, u32 **p)
1177 {
1178         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1179         u32 offset;
1180         u32 opaque_len;
1181         u32 maj_stat;
1182         int status = -EIO;
1183
1184         opaque_len = ntohl(*(*p)++);
1185         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1186         if (offset + opaque_len > rcv_buf->len)
1187                 return status;
1188         /* remove padding: */
1189         rcv_buf->len = offset + opaque_len;
1190
1191         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1192         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1193                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
1194         if (maj_stat != GSS_S_COMPLETE)
1195                 return status;
1196         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1197                 return status;
1198
1199         return 0;
1200 }
1201
1202
1203 static int
1204 gss_unwrap_resp(struct rpc_task *task,
1205                 kxdrproc_t decode, void *rqstp, u32 *p, void *obj)
1206 {
1207         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1208         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1209                         gc_base);
1210         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1211         u32             *savedp = p;
1212         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1213         int             savedlen = head->iov_len;
1214         int             status = -EIO;
1215
1216         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1217                 goto out_decode;
1218         switch (gss_cred->gc_service) {
1219                 case RPC_GSS_SVC_NONE:
1220                         break;
1221                 case RPC_GSS_SVC_INTEGRITY:
1222                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1223                         if (status)
1224                                 goto out;
1225                         break;
1226                 case RPC_GSS_SVC_PRIVACY:
1227                         status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1228                         if (status)
1229                                 goto out;
1230                         break;
1231         }
1232         /* take into account extra slack for integrity and privacy cases: */
1233         task->tk_auth->au_rslack = task->tk_auth->au_verfsize + (p - savedp)
1234                                                 + (savedlen - head->iov_len);
1235 out_decode:
1236         status = decode(rqstp, p, obj);
1237 out:
1238         gss_put_ctx(ctx);
1239         dprintk("RPC: %4u gss_unwrap_resp returning %d\n", task->tk_pid,
1240                         status);
1241         return status;
1242 }
1243
1244 static struct rpc_authops authgss_ops = {
1245         .owner          = THIS_MODULE,
1246         .au_flavor      = RPC_AUTH_GSS,
1247 #ifdef RPC_DEBUG
1248         .au_name        = "RPCSEC_GSS",
1249 #endif
1250         .create         = gss_create,
1251         .destroy        = gss_destroy,
1252         .lookup_cred    = gss_lookup_cred,
1253         .crcreate       = gss_create_cred
1254 };
1255
1256 static struct rpc_credops gss_credops = {
1257         .cr_name        = "AUTH_GSS",
1258         .crdestroy      = gss_destroy_cred,
1259         .cr_init        = gss_cred_init,
1260         .crmatch        = gss_match,
1261         .crmarshal      = gss_marshal,
1262         .crrefresh      = gss_refresh,
1263         .crvalidate     = gss_validate,
1264         .crwrap_req     = gss_wrap_req,
1265         .crunwrap_resp  = gss_unwrap_resp,
1266 };
1267
1268 static struct rpc_pipe_ops gss_upcall_ops = {
1269         .upcall         = gss_pipe_upcall,
1270         .downcall       = gss_pipe_downcall,
1271         .destroy_msg    = gss_pipe_destroy_msg,
1272         .release_pipe   = gss_pipe_release,
1273 };
1274
1275 /*
1276  * Initialize RPCSEC_GSS module
1277  */
1278 static int __init init_rpcsec_gss(void)
1279 {
1280         int err = 0;
1281
1282         err = rpcauth_register(&authgss_ops);
1283         if (err)
1284                 goto out;
1285         err = gss_svc_init();
1286         if (err)
1287                 goto out_unregister;
1288         return 0;
1289 out_unregister:
1290         rpcauth_unregister(&authgss_ops);
1291 out:
1292         return err;
1293 }
1294
1295 static void __exit exit_rpcsec_gss(void)
1296 {
1297         gss_svc_shutdown();
1298         rpcauth_unregister(&authgss_ops);
1299 }
1300
1301 MODULE_LICENSE("GPL");
1302 module_init(init_rpcsec_gss)
1303 module_exit(exit_rpcsec_gss)