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   1 /*
   2  * linux/net/sunrpc/auth_gss/auth_gss.c
   3  *
   4  * RPCSEC_GSS client authentication.
   5  *
   6  *  Copyright (c) 2000 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Dug Song       <dugsong@monkey.org>
  10  *  Andy Adamson   <andros@umich.edu>
  11  *
  12  *  Redistribution and use in source and binary forms, with or without
  13  *  modification, are permitted provided that the following conditions
  14  *  are met:
  15  *
  16  *  1. Redistributions of source code must retain the above copyright
  17  *     notice, this list of conditions and the following disclaimer.
  18  *  2. Redistributions in binary form must reproduce the above copyright
  19  *     notice, this list of conditions and the following disclaimer in the
  20  *     documentation and/or other materials provided with the distribution.
  21  *  3. Neither the name of the University nor the names of its
  22  *     contributors may be used to endorse or promote products derived
  23  *     from this software without specific prior written permission.
  24  *
  25  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  26  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  27  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  28  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  32  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  33  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  34  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  35  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38
  39 #include <linux/module.h>
  40 #include <linux/init.h>
  41 #include <linux/types.h>
  42 #include <linux/slab.h>
  43 #include <linux/sched.h>
  44 #include <linux/pagemap.h>
  45 #include <linux/sunrpc/clnt.h>
  46 #include <linux/sunrpc/auth.h>
  47 #include <linux/sunrpc/auth_gss.h>
  48 #include <linux/sunrpc/svcauth_gss.h>
  49 #include <linux/sunrpc/gss_err.h>
  50 #include <linux/workqueue.h>
  51 #include <linux/sunrpc/rpc_pipe_fs.h>
  52 #include <linux/sunrpc/gss_api.h>
  53 #include <asm/uaccess.h>
  54
  55 static const struct rpc_authops authgss_ops;
  56
  57 static const struct rpc_credops gss_credops;
  58 static const struct rpc_credops gss_nullops;
  59
  60 #ifdef RPC_DEBUG
  61 # define RPCDBG_FACILITY        RPCDBG_AUTH
  62 #endif
  63
  64 #define GSS_CRED_SLACK          1024
  65 /* length of a krb5 verifier (48), plus data added before arguments when
  66  * using integrity (two 4-byte integers): */
  67 #define GSS_VERF_SLACK          100
  68
  69 struct gss_auth {
  70         struct kref kref;
  71         struct rpc_auth rpc_auth;
  72         struct gss_api_mech *mech;
  73         enum rpc_gss_svc service;
  74         struct rpc_clnt *client;
  75         struct dentry *dentry;
  76 };
  77
  78 static void gss_free_ctx(struct gss_cl_ctx *);
  79 static struct rpc_pipe_ops gss_upcall_ops;
  80
  81 static inline struct gss_cl_ctx *
  82 gss_get_ctx(struct gss_cl_ctx *ctx)
  83 {
  84         atomic_inc(&ctx->count);
  85         return ctx;
  86 }
  87
  88 static inline void
  89 gss_put_ctx(struct gss_cl_ctx *ctx)
  90 {
  91         if (atomic_dec_and_test(&ctx->count))
  92                 gss_free_ctx(ctx);
  93 }
  94
  95 /* gss_cred_set_ctx:
  96  * called by gss_upcall_callback and gss_create_upcall in order
  97  * to set the gss context. The actual exchange of an old context
  98  * and a new one is protected by the inode->i_lock.
  99  */
 100 static void
 101 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 102 {
 103         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 104
 105         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 106                 return;
 107         gss_get_ctx(ctx);
 108         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 109         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 110         smp_mb__before_clear_bit();
 111         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 112 }
 113
 114 static const void *
 115 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 116 {
 117         const void *q = (const void *)((const char *)p + len);
 118         if (unlikely(q > end || q < p))
 119                 return ERR_PTR(-EFAULT);
 120         memcpy(res, p, len);
 121         return q;
 122 }
 123
 124 static inline const void *
 125 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 126 {
 127         const void *q;
 128         unsigned int len;
 129
 130         p = simple_get_bytes(p, end, &len, sizeof(len));
 131         if (IS_ERR(p))
 132                 return p;
 133         q = (const void *)((const char *)p + len);
 134         if (unlikely(q > end || q < p))
 135                 return ERR_PTR(-EFAULT);
 136         dest->data = kmemdup(p, len, GFP_NOFS);
 137         if (unlikely(dest->data == NULL))
 138                 return ERR_PTR(-ENOMEM);
 139         dest->len = len;
 140         return q;
 141 }
 142
 143 static struct gss_cl_ctx *
 144 gss_cred_get_ctx(struct rpc_cred *cred)
 145 {
 146         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 147         struct gss_cl_ctx *ctx = NULL;
 148
 149         rcu_read_lock();
 150         if (gss_cred->gc_ctx)
 151                 ctx = gss_get_ctx(gss_cred->gc_ctx);
 152         rcu_read_unlock();
 153         return ctx;
 154 }
 155
 156 static struct gss_cl_ctx *
 157 gss_alloc_context(void)
 158 {
 159         struct gss_cl_ctx *ctx;
 160
 161         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
 162         if (ctx != NULL) {
 163                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 164                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 165                 spin_lock_init(&ctx->gc_seq_lock);
 166                 atomic_set(&ctx->count,1);
 167         }
 168         return ctx;
 169 }
 170
 171 #define GSSD_MIN_TIMEOUT (60 * 60)
 172 static const void *
 173 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 174 {
 175         const void *q;
 176         unsigned int seclen;
 177         unsigned int timeout;
 178         u32 window_size;
 179         int ret;
 180
 181         /* First unsigned int gives the lifetime (in seconds) of the cred */
 182         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 183         if (IS_ERR(p))
 184                 goto err;
 185         if (timeout == 0)
 186                 timeout = GSSD_MIN_TIMEOUT;
 187         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
 188         /* Sequence number window. Determines the maximum number of simultaneous requests */
 189         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 190         if (IS_ERR(p))
 191                 goto err;
 192         ctx->gc_win = window_size;
 193         /* gssd signals an error by passing ctx->gc_win = 0: */
 194         if (ctx->gc_win == 0) {
 195                 /* in which case, p points to  an error code which we ignore */
 196                 p = ERR_PTR(-EACCES);
 197                 goto err;
 198         }
 199         /* copy the opaque wire context */
 200         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 201         if (IS_ERR(p))
 202                 goto err;
 203         /* import the opaque security context */
 204         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 205         if (IS_ERR(p))
 206                 goto err;
 207         q = (const void *)((const char *)p + seclen);
 208         if (unlikely(q > end || q < p)) {
 209                 p = ERR_PTR(-EFAULT);
 210                 goto err;
 211         }
 212         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
 213         if (ret < 0) {
 214                 p = ERR_PTR(ret);
 215                 goto err;
 216         }
 217         return q;
 218 err:
 219         dprintk("RPC:       gss_fill_context returning %ld\n", -PTR_ERR(p));
 220         return p;
 221 }
 222
 223
 224 struct gss_upcall_msg {
 225         atomic_t count;
 226         uid_t   uid;
 227         struct rpc_pipe_msg msg;
 228         struct list_head list;
 229         struct gss_auth *auth;
 230         struct rpc_wait_queue rpc_waitqueue;
 231         wait_queue_head_t waitqueue;
 232         struct gss_cl_ctx *ctx;
 233 };
 234
 235 static void
 236 gss_release_msg(struct gss_upcall_msg *gss_msg)
 237 {
 238         if (!atomic_dec_and_test(&gss_msg->count))
 239                 return;
 240         BUG_ON(!list_empty(&gss_msg->list));
 241         if (gss_msg->ctx != NULL)
 242                 gss_put_ctx(gss_msg->ctx);
 243         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 244         kfree(gss_msg);
 245 }
 246
 247 static struct gss_upcall_msg *
 248 __gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
 249 {
 250         struct gss_upcall_msg *pos;
 251         list_for_each_entry(pos, &rpci->in_downcall, list) {
 252                 if (pos->uid != uid)
 253                         continue;
 254                 atomic_inc(&pos->count);
 255                 dprintk("RPC:       gss_find_upcall found msg %p\n", pos);
 256                 return pos;
 257         }
 258         dprintk("RPC:       gss_find_upcall found nothing\n");
 259         return NULL;
 260 }
 261
 262 /* Try to add an upcall to the pipefs queue.
 263  * If an upcall owned by our uid already exists, then we return a reference
 264  * to that upcall instead of adding the new upcall.
 265  */
 266 static inline struct gss_upcall_msg *
 267 gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
 268 {
 269         struct inode *inode = gss_auth->dentry->d_inode;
 270         struct rpc_inode *rpci = RPC_I(inode);
 271         struct gss_upcall_msg *old;
 272
 273         spin_lock(&inode->i_lock);
 274         old = __gss_find_upcall(rpci, gss_msg->uid);
 275         if (old == NULL) {
 276                 atomic_inc(&gss_msg->count);
 277                 list_add(&gss_msg->list, &rpci->in_downcall);
 278         } else
 279                 gss_msg = old;
 280         spin_unlock(&inode->i_lock);
 281         return gss_msg;
 282 }
 283
 284 static void
 285 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 286 {
 287         list_del_init(&gss_msg->list);
 288         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 289         wake_up_all(&gss_msg->waitqueue);
 290         atomic_dec(&gss_msg->count);
 291 }
 292
 293 static void
 294 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 295 {
 296         struct gss_auth *gss_auth = gss_msg->auth;
 297         struct inode *inode = gss_auth->dentry->d_inode;
 298
 299         if (list_empty(&gss_msg->list))
 300                 return;
 301         spin_lock(&inode->i_lock);
 302         if (!list_empty(&gss_msg->list))
 303                 __gss_unhash_msg(gss_msg);
 304         spin_unlock(&inode->i_lock);
 305 }
 306
 307 static void
 308 gss_upcall_callback(struct rpc_task *task)
 309 {
 310         struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
 311                         struct gss_cred, gc_base);
 312         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 313         struct inode *inode = gss_msg->auth->dentry->d_inode;
 314
 315         spin_lock(&inode->i_lock);
 316         if (gss_msg->ctx)
 317                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
 318         else
 319                 task->tk_status = gss_msg->msg.errno;
 320         gss_cred->gc_upcall = NULL;
 321         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 322         spin_unlock(&inode->i_lock);
 323         gss_release_msg(gss_msg);
 324 }
 325
 326 static inline struct gss_upcall_msg *
 327 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid)
 328 {
 329         struct gss_upcall_msg *gss_msg;
 330
 331         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 332         if (gss_msg != NULL) {
 333                 INIT_LIST_HEAD(&gss_msg->list);
 334                 rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 335                 init_waitqueue_head(&gss_msg->waitqueue);
 336                 atomic_set(&gss_msg->count, 1);
 337                 gss_msg->msg.data = &gss_msg->uid;
 338                 gss_msg->msg.len = sizeof(gss_msg->uid);
 339                 gss_msg->uid = uid;
 340                 gss_msg->auth = gss_auth;
 341         }
 342         return gss_msg;
 343 }
 344
 345 static struct gss_upcall_msg *
 346 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
 347 {
 348         struct gss_cred *gss_cred = container_of(cred,
 349                         struct gss_cred, gc_base);
 350         struct gss_upcall_msg *gss_new, *gss_msg;
 351         uid_t uid = cred->cr_uid;
 352
 353         /* Special case: rpc.gssd assumes that uid == 0 implies machine creds */
 354         if (gss_cred->gc_machine_cred != 0)
 355                 uid = 0;
 356
 357         gss_new = gss_alloc_msg(gss_auth, uid);
 358         if (gss_new == NULL)
 359                 return ERR_PTR(-ENOMEM);
 360         gss_msg = gss_add_msg(gss_auth, gss_new);
 361         if (gss_msg == gss_new) {
 362                 int res = rpc_queue_upcall(gss_auth->dentry->d_inode, &gss_new->msg);
 363                 if (res) {
 364                         gss_unhash_msg(gss_new);
 365                         gss_msg = ERR_PTR(res);
 366                 }
 367         } else
 368                 gss_release_msg(gss_new);
 369         return gss_msg;
 370 }
 371
 372 static inline int
 373 gss_refresh_upcall(struct rpc_task *task)
 374 {
 375         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 376         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 377                         struct gss_auth, rpc_auth);
 378         struct gss_cred *gss_cred = container_of(cred,
 379                         struct gss_cred, gc_base);
 380         struct gss_upcall_msg *gss_msg;
 381         struct inode *inode = gss_auth->dentry->d_inode;
 382         int err = 0;
 383
 384         dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
 385                                                                 cred->cr_uid);
 386         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
 387         if (IS_ERR(gss_msg)) {
 388                 err = PTR_ERR(gss_msg);
 389                 goto out;
 390         }
 391         spin_lock(&inode->i_lock);
 392         if (gss_cred->gc_upcall != NULL)
 393                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 394         else if (gss_msg->ctx != NULL) {
 395                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
 396                 gss_cred->gc_upcall = NULL;
 397                 rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 398         } else if (gss_msg->msg.errno >= 0) {
 399                 task->tk_timeout = 0;
 400                 gss_cred->gc_upcall = gss_msg;
 401                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 402                 atomic_inc(&gss_msg->count);
 403                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 404         } else
 405                 err = gss_msg->msg.errno;
 406         spin_unlock(&inode->i_lock);
 407         gss_release_msg(gss_msg);
 408 out:
 409         dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
 410                         task->tk_pid, cred->cr_uid, err);
 411         return err;
 412 }
 413
 414 static inline int
 415 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 416 {
 417         struct inode *inode = gss_auth->dentry->d_inode;
 418         struct rpc_cred *cred = &gss_cred->gc_base;
 419         struct gss_upcall_msg *gss_msg;
 420         DEFINE_WAIT(wait);
 421         int err = 0;
 422
 423         dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
 424         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 425         if (IS_ERR(gss_msg)) {
 426                 err = PTR_ERR(gss_msg);
 427                 goto out;
 428         }
 429         for (;;) {
 430                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
 431                 spin_lock(&inode->i_lock);
 432                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 433                         break;
 434                 }
 435                 spin_unlock(&inode->i_lock);
 436                 if (signalled()) {
 437                         err = -ERESTARTSYS;
 438                         goto out_intr;
 439                 }
 440                 schedule();
 441         }
 442         if (gss_msg->ctx)
 443                 gss_cred_set_ctx(cred, gss_msg->ctx);
 444         else
 445                 err = gss_msg->msg.errno;
 446         spin_unlock(&inode->i_lock);
 447 out_intr:
 448         finish_wait(&gss_msg->waitqueue, &wait);
 449         gss_release_msg(gss_msg);
 450 out:
 451         dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
 452                         cred->cr_uid, err);
 453         return err;
 454 }
 455
 456 static ssize_t
 457 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 458                 char __user *dst, size_t buflen)
 459 {
 460         char *data = (char *)msg->data + msg->copied;
 461         size_t mlen = min(msg->len, buflen);
 462         unsigned long left;
 463
 464         left = copy_to_user(dst, data, mlen);
 465         if (left == mlen) {
 466                 msg->errno = -EFAULT;
 467                 return -EFAULT;
 468         }
 469
 470         mlen -= left;
 471         msg->copied += mlen;
 472         msg->errno = 0;
 473         return mlen;
 474 }
 475
 476 #define MSG_BUF_MAXSIZE 1024
 477
 478 static ssize_t
 479 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 480 {
 481         const void *p, *end;
 482         void *buf;
 483         struct gss_upcall_msg *gss_msg;
 484         struct inode *inode = filp->f_path.dentry->d_inode;
 485         struct gss_cl_ctx *ctx;
 486         uid_t uid;
 487         ssize_t err = -EFBIG;
 488
 489         if (mlen > MSG_BUF_MAXSIZE)
 490                 goto out;
 491         err = -ENOMEM;
 492         buf = kmalloc(mlen, GFP_NOFS);
 493         if (!buf)
 494                 goto out;
 495
 496         err = -EFAULT;
 497         if (copy_from_user(buf, src, mlen))
 498                 goto err;
 499
 500         end = (const void *)((char *)buf + mlen);
 501         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
 502         if (IS_ERR(p)) {
 503                 err = PTR_ERR(p);
 504                 goto err;
 505         }
 506
 507         err = -ENOMEM;
 508         ctx = gss_alloc_context();
 509         if (ctx == NULL)
 510                 goto err;
 511
 512         err = -ENOENT;
 513         /* Find a matching upcall */
 514         spin_lock(&inode->i_lock);
 515         gss_msg = __gss_find_upcall(RPC_I(inode), uid);
 516         if (gss_msg == NULL) {
 517                 spin_unlock(&inode->i_lock);
 518                 goto err_put_ctx;
 519         }
 520         list_del_init(&gss_msg->list);
 521         spin_unlock(&inode->i_lock);
 522
 523         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 524         if (IS_ERR(p)) {
 525                 err = PTR_ERR(p);
 526                 gss_msg->msg.errno = (err == -EAGAIN) ? -EAGAIN : -EACCES;
 527                 goto err_release_msg;
 528         }
 529         gss_msg->ctx = gss_get_ctx(ctx);
 530         err = mlen;
 531
 532 err_release_msg:
 533         spin_lock(&inode->i_lock);
 534         __gss_unhash_msg(gss_msg);
 535         spin_unlock(&inode->i_lock);
 536         gss_release_msg(gss_msg);
 537 err_put_ctx:
 538         gss_put_ctx(ctx);
 539 err:
 540         kfree(buf);
 541 out:
 542         dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
 543         return err;
 544 }
 545
 546 static void
 547 gss_pipe_release(struct inode *inode)
 548 {
 549         struct rpc_inode *rpci = RPC_I(inode);
 550         struct gss_upcall_msg *gss_msg;
 551
 552         spin_lock(&inode->i_lock);
 553         while (!list_empty(&rpci->in_downcall)) {
 554
 555                 gss_msg = list_entry(rpci->in_downcall.next,
 556                                 struct gss_upcall_msg, list);
 557                 gss_msg->msg.errno = -EPIPE;
 558                 atomic_inc(&gss_msg->count);
 559                 __gss_unhash_msg(gss_msg);
 560                 spin_unlock(&inode->i_lock);
 561                 gss_release_msg(gss_msg);
 562                 spin_lock(&inode->i_lock);
 563         }
 564         spin_unlock(&inode->i_lock);
 565 }
 566
 567 static void
 568 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 569 {
 570         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 571         static unsigned long ratelimit;
 572
 573         if (msg->errno < 0) {
 574                 dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
 575                                 gss_msg);
 576                 atomic_inc(&gss_msg->count);
 577                 gss_unhash_msg(gss_msg);
 578                 if (msg->errno == -ETIMEDOUT) {
 579                         unsigned long now = jiffies;
 580                         if (time_after(now, ratelimit)) {
 581                                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 582                                                     "Please check user daemon is running!\n");
 583                                 ratelimit = now + 15*HZ;
 584                         }
 585                 }
 586                 gss_release_msg(gss_msg);
 587         }
 588 }
 589
 590 /*
 591  * NOTE: we have the opportunity to use different
 592  * parameters based on the input flavor (which must be a pseudoflavor)
 593  */
 594 static struct rpc_auth *
 595 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 596 {
 597         struct gss_auth *gss_auth;
 598         struct rpc_auth * auth;
 599         int err = -ENOMEM; /* XXX? */
 600
 601         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 602
 603         if (!try_module_get(THIS_MODULE))
 604                 return ERR_PTR(err);
 605         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 606                 goto out_dec;
 607         gss_auth->client = clnt;
 608         err = -EINVAL;
 609         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 610         if (!gss_auth->mech) {
 611                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
 612                                 __func__, flavor);
 613                 goto err_free;
 614         }
 615         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 616         if (gss_auth->service == 0)
 617                 goto err_put_mech;
 618         auth = &gss_auth->rpc_auth;
 619         auth->au_cslack = GSS_CRED_SLACK >> 2;
 620         auth->au_rslack = GSS_VERF_SLACK >> 2;
 621         auth->au_ops = &authgss_ops;
 622         auth->au_flavor = flavor;
 623         atomic_set(&auth->au_count, 1);
 624         kref_init(&gss_auth->kref);
 625
 626         gss_auth->dentry = rpc_mkpipe(clnt->cl_dentry, gss_auth->mech->gm_name,
 627                         clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 628         if (IS_ERR(gss_auth->dentry)) {
 629                 err = PTR_ERR(gss_auth->dentry);
 630                 goto err_put_mech;
 631         }
 632
 633         err = rpcauth_init_credcache(auth);
 634         if (err)
 635                 goto err_unlink_pipe;
 636
 637         return auth;
 638 err_unlink_pipe:
 639         rpc_unlink(gss_auth->dentry);
 640 err_put_mech:
 641         gss_mech_put(gss_auth->mech);
 642 err_free:
 643         kfree(gss_auth);
 644 out_dec:
 645         module_put(THIS_MODULE);
 646         return ERR_PTR(err);
 647 }
 648
 649 static void
 650 gss_free(struct gss_auth *gss_auth)
 651 {
 652         rpc_unlink(gss_auth->dentry);
 653         gss_auth->dentry = NULL;
 654         gss_mech_put(gss_auth->mech);
 655
 656         kfree(gss_auth);
 657         module_put(THIS_MODULE);
 658 }
 659
 660 static void
 661 gss_free_callback(struct kref *kref)
 662 {
 663         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
 664
 665         gss_free(gss_auth);
 666 }
 667
 668 static void
 669 gss_destroy(struct rpc_auth *auth)
 670 {
 671         struct gss_auth *gss_auth;
 672
 673         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
 674                         auth, auth->au_flavor);
 675
 676         rpcauth_destroy_credcache(auth);
 677
 678         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 679         kref_put(&gss_auth->kref, gss_free_callback);
 680 }
 681
 682 /*
 683  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
 684  * to the server with the GSS control procedure field set to
 685  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
 686  * all RPCSEC_GSS state associated with that context.
 687  */
 688 static int
 689 gss_destroying_context(struct rpc_cred *cred)
 690 {
 691         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 692         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 693         struct rpc_task *task;
 694
 695         if (gss_cred->gc_ctx == NULL ||
 696             test_and_clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 697                 return 0;
 698
 699         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
 700         cred->cr_ops = &gss_nullops;
 701
 702         /* Take a reference to ensure the cred will be destroyed either
 703          * by the RPC call or by the put_rpccred() below */
 704         get_rpccred(cred);
 705
 706         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
 707         if (!IS_ERR(task))
 708                 rpc_put_task(task);
 709
 710         put_rpccred(cred);
 711         return 1;
 712 }
 713
 714 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
 715  * to create a new cred or context, so they check that things have been
 716  * allocated before freeing them. */
 717 static void
 718 gss_do_free_ctx(struct gss_cl_ctx *ctx)
 719 {
 720         dprintk("RPC:       gss_free_ctx\n");
 721
 722         kfree(ctx->gc_wire_ctx.data);
 723         kfree(ctx);
 724 }
 725
 726 static void
 727 gss_free_ctx_callback(struct rcu_head *head)
 728 {
 729         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
 730         gss_do_free_ctx(ctx);
 731 }
 732
 733 static void
 734 gss_free_ctx(struct gss_cl_ctx *ctx)
 735 {
 736         struct gss_ctx *gc_gss_ctx;
 737
 738         gc_gss_ctx = rcu_dereference(ctx->gc_gss_ctx);
 739         rcu_assign_pointer(ctx->gc_gss_ctx, NULL);
 740         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
 741         if (gc_gss_ctx)
 742                 gss_delete_sec_context(&gc_gss_ctx);
 743 }
 744
 745 static void
 746 gss_free_cred(struct gss_cred *gss_cred)
 747 {
 748         dprintk("RPC:       gss_free_cred %p\n", gss_cred);
 749         kfree(gss_cred);
 750 }
 751
 752 static void
 753 gss_free_cred_callback(struct rcu_head *head)
 754 {
 755         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
 756         gss_free_cred(gss_cred);
 757 }
 758
 759 static void
 760 gss_destroy_cred(struct rpc_cred *cred)
 761 {
 762         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 763         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 764         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
 765
 766         if (gss_destroying_context(cred))
 767                 return;
 768         rcu_assign_pointer(gss_cred->gc_ctx, NULL);
 769         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
 770         if (ctx)
 771                 gss_put_ctx(ctx);
 772         kref_put(&gss_auth->kref, gss_free_callback);
 773 }
 774
 775 /*
 776  * Lookup RPCSEC_GSS cred for the current process
 777  */
 778 static struct rpc_cred *
 779 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 780 {
 781         return rpcauth_lookup_credcache(auth, acred, flags);
 782 }
 783
 784 static struct rpc_cred *
 785 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 786 {
 787         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 788         struct gss_cred *cred = NULL;
 789         int err = -ENOMEM;
 790
 791         dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
 792                 acred->uid, auth->au_flavor);
 793
 794         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
 795                 goto out_err;
 796
 797         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
 798         /*
 799          * Note: in order to force a call to call_refresh(), we deliberately
 800          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
 801          */
 802         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
 803         cred->gc_service = gss_auth->service;
 804         cred->gc_machine_cred = acred->machine_cred;
 805         kref_get(&gss_auth->kref);
 806         return &cred->gc_base;
 807
 808 out_err:
 809         dprintk("RPC:       gss_create_cred failed with error %d\n", err);
 810         return ERR_PTR(err);
 811 }
 812
 813 static int
 814 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
 815 {
 816         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 817         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
 818         int err;
 819
 820         do {
 821                 err = gss_create_upcall(gss_auth, gss_cred);
 822         } while (err == -EAGAIN);
 823         return err;
 824 }
 825
 826 static int
 827 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
 828 {
 829         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
 830
 831         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
 832                 goto out;
 833         /* Don't match with creds that have expired. */
 834         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
 835                 return 0;
 836         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
 837                 return 0;
 838 out:
 839         if (acred->machine_cred != gss_cred->gc_machine_cred)
 840                 return 0;
 841         return (rc->cr_uid == acred->uid);
 842 }
 843
 844 /*
 845 * Marshal credentials.
 846 * Maybe we should keep a cached credential for performance reasons.
 847 */
 848 static __be32 *
 849 gss_marshal(struct rpc_task *task, __be32 *p)
 850 {
 851         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 852         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
 853                                                  gc_base);
 854         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
 855         __be32          *cred_len;
 856         struct rpc_rqst *req = task->tk_rqstp;
 857         u32             maj_stat = 0;
 858         struct xdr_netobj mic;
 859         struct kvec     iov;
 860         struct xdr_buf  verf_buf;
 861
 862         dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
 863
 864         *p++ = htonl(RPC_AUTH_GSS);
 865         cred_len = p++;
 866
 867         spin_lock(&ctx->gc_seq_lock);
 868         req->rq_seqno = ctx->gc_seq++;
 869         spin_unlock(&ctx->gc_seq_lock);
 870
 871         *p++ = htonl((u32) RPC_GSS_VERSION);
 872         *p++ = htonl((u32) ctx->gc_proc);
 873         *p++ = htonl((u32) req->rq_seqno);
 874         *p++ = htonl((u32) gss_cred->gc_service);
 875         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
 876         *cred_len = htonl((p - (cred_len + 1)) << 2);
 877
 878         /* We compute the checksum for the verifier over the xdr-encoded bytes
 879          * starting with the xid and ending at the end of the credential: */
 880         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
 881                                         req->rq_snd_buf.head[0].iov_base);
 882         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
 883         xdr_buf_from_iov(&iov, &verf_buf);
 884
 885         /* set verifier flavor*/
 886         *p++ = htonl(RPC_AUTH_GSS);
 887
 888         mic.data = (u8 *)(p + 1);
 889         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 890         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
 891                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 892         } else if (maj_stat != 0) {
 893                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
 894                 goto out_put_ctx;
 895         }
 896         p = xdr_encode_opaque(p, NULL, mic.len);
 897         gss_put_ctx(ctx);
 898         return p;
 899 out_put_ctx:
 900         gss_put_ctx(ctx);
 901         return NULL;
 902 }
 903
 904 static int gss_renew_cred(struct rpc_task *task)
 905 {
 906         struct rpc_cred *oldcred = task->tk_msg.rpc_cred;
 907         struct gss_cred *gss_cred = container_of(oldcred,
 908                                                  struct gss_cred,
 909                                                  gc_base);
 910         struct rpc_auth *auth = oldcred->cr_auth;
 911         struct auth_cred acred = {
 912                 .uid = oldcred->cr_uid,
 913                 .machine_cred = gss_cred->gc_machine_cred,
 914         };
 915         struct rpc_cred *new;
 916
 917         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
 918         if (IS_ERR(new))
 919                 return PTR_ERR(new);
 920         task->tk_msg.rpc_cred = new;
 921         put_rpccred(oldcred);
 922         return 0;
 923 }
 924
 925 /*
 926 * Refresh credentials. XXX - finish
 927 */
 928 static int
 929 gss_refresh(struct rpc_task *task)
 930 {
 931         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 932         int ret = 0;
 933
 934         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
 935                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
 936                 ret = gss_renew_cred(task);
 937                 if (ret < 0)
 938                         goto out;
 939                 cred = task->tk_msg.rpc_cred;
 940         }
 941
 942         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 943                 ret = gss_refresh_upcall(task);
 944 out:
 945         return ret;
 946 }
 947
 948 /* Dummy refresh routine: used only when destroying the context */
 949 static int
 950 gss_refresh_null(struct rpc_task *task)
 951 {
 952         return -EACCES;
 953 }
 954
 955 static __be32 *
 956 gss_validate(struct rpc_task *task, __be32 *p)
 957 {
 958         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 959         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
 960         __be32          seq;
 961         struct kvec     iov;
 962         struct xdr_buf  verf_buf;
 963         struct xdr_netobj mic;
 964         u32             flav,len;
 965         u32             maj_stat;
 966
 967         dprintk("RPC: %5u gss_validate\n", task->tk_pid);
 968
 969         flav = ntohl(*p++);
 970         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
 971                 goto out_bad;
 972         if (flav != RPC_AUTH_GSS)
 973                 goto out_bad;
 974         seq = htonl(task->tk_rqstp->rq_seqno);
 975         iov.iov_base = &seq;
 976         iov.iov_len = sizeof(seq);
 977         xdr_buf_from_iov(&iov, &verf_buf);
 978         mic.data = (u8 *)p;
 979         mic.len = len;
 980
 981         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 982         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
 983                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 984         if (maj_stat) {
 985                 dprintk("RPC: %5u gss_validate: gss_verify_mic returned "
 986                                 "error 0x%08x\n", task->tk_pid, maj_stat);
 987                 goto out_bad;
 988         }
 989         /* We leave it to unwrap to calculate au_rslack. For now we just
 990          * calculate the length of the verifier: */
 991         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
 992         gss_put_ctx(ctx);
 993         dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
 994                         task->tk_pid);
 995         return p + XDR_QUADLEN(len);
 996 out_bad:
 997         gss_put_ctx(ctx);
 998         dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
 999         return NULL;
1000 }
1001
1002 static inline int
1003 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1004                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1005 {
1006         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1007         struct xdr_buf  integ_buf;
1008         __be32          *integ_len = NULL;
1009         struct xdr_netobj mic;
1010         u32             offset;
1011         __be32          *q;
1012         struct kvec     *iov;
1013         u32             maj_stat = 0;
1014         int             status = -EIO;
1015
1016         integ_len = p++;
1017         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1018         *p++ = htonl(rqstp->rq_seqno);
1019
1020         status = rpc_call_xdrproc(encode, rqstp, p, obj);
1021         if (status)
1022                 return status;
1023
1024         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1025                                 offset, snd_buf->len - offset))
1026                 return status;
1027         *integ_len = htonl(integ_buf.len);
1028
1029         /* guess whether we're in the head or the tail: */
1030         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1031                 iov = snd_buf->tail;
1032         else
1033                 iov = snd_buf->head;
1034         p = iov->iov_base + iov->iov_len;
1035         mic.data = (u8 *)(p + 1);
1036
1037         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1038         status = -EIO; /* XXX? */
1039         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1040                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1041         else if (maj_stat)
1042                 return status;
1043         q = xdr_encode_opaque(p, NULL, mic.len);
1044
1045         offset = (u8 *)q - (u8 *)p;
1046         iov->iov_len += offset;
1047         snd_buf->len += offset;
1048         return 0;
1049 }
1050
1051 static void
1052 priv_release_snd_buf(struct rpc_rqst *rqstp)
1053 {
1054         int i;
1055
1056         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1057                 __free_page(rqstp->rq_enc_pages[i]);
1058         kfree(rqstp->rq_enc_pages);
1059 }
1060
1061 static int
1062 alloc_enc_pages(struct rpc_rqst *rqstp)
1063 {
1064         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1065         int first, last, i;
1066
1067         if (snd_buf->page_len == 0) {
1068                 rqstp->rq_enc_pages_num = 0;
1069                 return 0;
1070         }
1071
1072         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1073         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1074         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1075         rqstp->rq_enc_pages
1076                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1077                                 GFP_NOFS);
1078         if (!rqstp->rq_enc_pages)
1079                 goto out;
1080         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1081                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1082                 if (rqstp->rq_enc_pages[i] == NULL)
1083                         goto out_free;
1084         }
1085         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1086         return 0;
1087 out_free:
1088         for (i--; i >= 0; i--) {
1089                 __free_page(rqstp->rq_enc_pages[i]);
1090         }
1091 out:
1092         return -EAGAIN;
1093 }
1094
1095 static inline int
1096 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1097                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1098 {
1099         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1100         u32             offset;
1101         u32             maj_stat;
1102         int             status;
1103         __be32          *opaque_len;
1104         struct page     **inpages;
1105         int             first;
1106         int             pad;
1107         struct kvec     *iov;
1108         char            *tmp;
1109
1110         opaque_len = p++;
1111         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1112         *p++ = htonl(rqstp->rq_seqno);
1113
1114         status = rpc_call_xdrproc(encode, rqstp, p, obj);
1115         if (status)
1116                 return status;
1117
1118         status = alloc_enc_pages(rqstp);
1119         if (status)
1120                 return status;
1121         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1122         inpages = snd_buf->pages + first;
1123         snd_buf->pages = rqstp->rq_enc_pages;
1124         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1125         /* Give the tail its own page, in case we need extra space in the
1126          * head when wrapping: */
1127         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1128                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1129                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1130                 snd_buf->tail[0].iov_base = tmp;
1131         }
1132         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1133         /* RPC_SLACK_SPACE should prevent this ever happening: */
1134         BUG_ON(snd_buf->len > snd_buf->buflen);
1135         status = -EIO;
1136         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1137          * done anyway, so it's safe to put the request on the wire: */
1138         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1139                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1140         else if (maj_stat)
1141                 return status;
1142
1143         *opaque_len = htonl(snd_buf->len - offset);
1144         /* guess whether we're in the head or the tail: */
1145         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1146                 iov = snd_buf->tail;
1147         else
1148                 iov = snd_buf->head;
1149         p = iov->iov_base + iov->iov_len;
1150         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1151         memset(p, 0, pad);
1152         iov->iov_len += pad;
1153         snd_buf->len += pad;
1154
1155         return 0;
1156 }
1157
1158 static int
1159 gss_wrap_req(struct rpc_task *task,
1160              kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
1161 {
1162         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1163         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1164                         gc_base);
1165         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1166         int             status = -EIO;
1167
1168         dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
1169         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1170                 /* The spec seems a little ambiguous here, but I think that not
1171                  * wrapping context destruction requests makes the most sense.
1172                  */
1173                 status = rpc_call_xdrproc(encode, rqstp, p, obj);
1174                 goto out;
1175         }
1176         switch (gss_cred->gc_service) {
1177                 case RPC_GSS_SVC_NONE:
1178                         status = rpc_call_xdrproc(encode, rqstp, p, obj);
1179                         break;
1180                 case RPC_GSS_SVC_INTEGRITY:
1181                         status = gss_wrap_req_integ(cred, ctx, encode,
1182                                                                 rqstp, p, obj);
1183                         break;
1184                 case RPC_GSS_SVC_PRIVACY:
1185                         status = gss_wrap_req_priv(cred, ctx, encode,
1186                                         rqstp, p, obj);
1187                         break;
1188         }
1189 out:
1190         gss_put_ctx(ctx);
1191         dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
1192         return status;
1193 }
1194
1195 static inline int
1196 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1197                 struct rpc_rqst *rqstp, __be32 **p)
1198 {
1199         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1200         struct xdr_buf integ_buf;
1201         struct xdr_netobj mic;
1202         u32 data_offset, mic_offset;
1203         u32 integ_len;
1204         u32 maj_stat;
1205         int status = -EIO;
1206
1207         integ_len = ntohl(*(*p)++);
1208         if (integ_len & 3)
1209                 return status;
1210         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1211         mic_offset = integ_len + data_offset;
1212         if (mic_offset > rcv_buf->len)
1213                 return status;
1214         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1215                 return status;
1216
1217         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1218                                 mic_offset - data_offset))
1219                 return status;
1220
1221         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1222                 return status;
1223
1224         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1225         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1226                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1227         if (maj_stat != GSS_S_COMPLETE)
1228                 return status;
1229         return 0;
1230 }
1231
1232 static inline int
1233 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1234                 struct rpc_rqst *rqstp, __be32 **p)
1235 {
1236         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1237         u32 offset;
1238         u32 opaque_len;
1239         u32 maj_stat;
1240         int status = -EIO;
1241
1242         opaque_len = ntohl(*(*p)++);
1243         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1244         if (offset + opaque_len > rcv_buf->len)
1245                 return status;
1246         /* remove padding: */
1247         rcv_buf->len = offset + opaque_len;
1248
1249         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1250         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1251                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1252         if (maj_stat != GSS_S_COMPLETE)
1253                 return status;
1254         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1255                 return status;
1256
1257         return 0;
1258 }
1259
1260
1261 static int
1262 gss_unwrap_resp(struct rpc_task *task,
1263                 kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
1264 {
1265         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1266         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1267                         gc_base);
1268         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1269         __be32          *savedp = p;
1270         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1271         int             savedlen = head->iov_len;
1272         int             status = -EIO;
1273
1274         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1275                 goto out_decode;
1276         switch (gss_cred->gc_service) {
1277                 case RPC_GSS_SVC_NONE:
1278                         break;
1279                 case RPC_GSS_SVC_INTEGRITY:
1280                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1281                         if (status)
1282                                 goto out;
1283                         break;
1284                 case RPC_GSS_SVC_PRIVACY:
1285                         status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1286                         if (status)
1287                                 goto out;
1288                         break;
1289         }
1290         /* take into account extra slack for integrity and privacy cases: */
1291         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1292                                                 + (savedlen - head->iov_len);
1293 out_decode:
1294         status = rpc_call_xdrproc(decode, rqstp, p, obj);
1295 out:
1296         gss_put_ctx(ctx);
1297         dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
1298                         status);
1299         return status;
1300 }
1301
1302 static const struct rpc_authops authgss_ops = {
1303         .owner          = THIS_MODULE,
1304         .au_flavor      = RPC_AUTH_GSS,
1305         .au_name        = "RPCSEC_GSS",
1306         .create         = gss_create,
1307         .destroy        = gss_destroy,
1308         .lookup_cred    = gss_lookup_cred,
1309         .crcreate       = gss_create_cred
1310 };
1311
1312 static const struct rpc_credops gss_credops = {
1313         .cr_name        = "AUTH_GSS",
1314         .crdestroy      = gss_destroy_cred,
1315         .cr_init        = gss_cred_init,
1316         .crbind         = rpcauth_generic_bind_cred,
1317         .crmatch        = gss_match,
1318         .crmarshal      = gss_marshal,
1319         .crrefresh      = gss_refresh,
1320         .crvalidate     = gss_validate,
1321         .crwrap_req     = gss_wrap_req,
1322         .crunwrap_resp  = gss_unwrap_resp,
1323 };
1324
1325 static const struct rpc_credops gss_nullops = {
1326         .cr_name        = "AUTH_GSS",
1327         .crdestroy      = gss_destroy_cred,
1328         .crbind         = rpcauth_generic_bind_cred,
1329         .crmatch        = gss_match,
1330         .crmarshal      = gss_marshal,
1331         .crrefresh      = gss_refresh_null,
1332         .crvalidate     = gss_validate,
1333         .crwrap_req     = gss_wrap_req,
1334         .crunwrap_resp  = gss_unwrap_resp,
1335 };
1336
1337 static struct rpc_pipe_ops gss_upcall_ops = {
1338         .upcall         = gss_pipe_upcall,
1339         .downcall       = gss_pipe_downcall,
1340         .destroy_msg    = gss_pipe_destroy_msg,
1341         .release_pipe   = gss_pipe_release,
1342 };
1343
1344 /*
1345  * Initialize RPCSEC_GSS module
1346  */
1347 static int __init init_rpcsec_gss(void)
1348 {
1349         int err = 0;
1350
1351         err = rpcauth_register(&authgss_ops);
1352         if (err)
1353                 goto out;
1354         err = gss_svc_init();
1355         if (err)
1356                 goto out_unregister;
1357         return 0;
1358 out_unregister:
1359         rpcauth_unregister(&authgss_ops);
1360 out:
1361         return err;
1362 }
1363
1364 static void __exit exit_rpcsec_gss(void)
1365 {
1366         gss_svc_shutdown();
1367         rpcauth_unregister(&authgss_ops);
1368 }
1369
1370 MODULE_LICENSE("GPL");
1371 module_init(init_rpcsec_gss)
1372 module_exit(exit_rpcsec_gss)