net/sunrpc/auth_gss/auth_gss.c

   1 /*
   2  * linux/net/sunrpc/auth_gss/auth_gss.c
   3  *
   4  * RPCSEC_GSS client authentication.
   5  *
   6  *  Copyright (c) 2000 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Dug Song       <dugsong@monkey.org>
  10  *  Andy Adamson   <andros@umich.edu>
  11  *
  12  *  Redistribution and use in source and binary forms, with or without
  13  *  modification, are permitted provided that the following conditions
  14  *  are met:
  15  *
  16  *  1. Redistributions of source code must retain the above copyright
  17  *     notice, this list of conditions and the following disclaimer.
  18  *  2. Redistributions in binary form must reproduce the above copyright
  19  *     notice, this list of conditions and the following disclaimer in the
  20  *     documentation and/or other materials provided with the distribution.
  21  *  3. Neither the name of the University nor the names of its
  22  *     contributors may be used to endorse or promote products derived
  23  *     from this software without specific prior written permission.
  24  *
  25  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  26  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  27  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  28  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  32  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  33  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  34  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  35  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  *
  37  * $Id$
  38  */
  39
  40
  41 #include <linux/module.h>
  42 #include <linux/init.h>
  43 #include <linux/types.h>
  44 #include <linux/slab.h>
  45 #include <linux/sched.h>
  46 #include <linux/pagemap.h>
  47 #include <linux/sunrpc/clnt.h>
  48 #include <linux/sunrpc/auth.h>
  49 #include <linux/sunrpc/auth_gss.h>
  50 #include <linux/sunrpc/svcauth_gss.h>
  51 #include <linux/sunrpc/gss_err.h>
  52 #include <linux/workqueue.h>
  53 #include <linux/sunrpc/rpc_pipe_fs.h>
  54 #include <linux/sunrpc/gss_api.h>
  55 #include <asm/uaccess.h>
  56
  57 static const struct rpc_authops authgss_ops;
  58
  59 static const struct rpc_credops gss_credops;
  60 static const struct rpc_credops gss_nullops;
  61
  62 #ifdef RPC_DEBUG
  63 # define RPCDBG_FACILITY        RPCDBG_AUTH
  64 #endif
  65
  66 #define NFS_NGROUPS     16
  67
  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          100
  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 struct gss_auth {
  83         struct kref kref;
  84         struct rpc_auth rpc_auth;
  85         struct gss_api_mech *mech;
  86         enum rpc_gss_svc service;
  87         struct rpc_clnt *client;
  88         struct dentry *dentry;
  89 };
  90
  91 static void gss_free_ctx(struct gss_cl_ctx *);
  92 static struct rpc_pipe_ops gss_upcall_ops;
  93
  94 static inline struct gss_cl_ctx *
  95 gss_get_ctx(struct gss_cl_ctx *ctx)
  96 {
  97         atomic_inc(&ctx->count);
  98         return ctx;
  99 }
 100
 101 static inline void
 102 gss_put_ctx(struct gss_cl_ctx *ctx)
 103 {
 104         if (atomic_dec_and_test(&ctx->count))
 105                 gss_free_ctx(ctx);
 106 }
 107
 108 /* gss_cred_set_ctx:
 109  * called by gss_upcall_callback and gss_create_upcall in order
 110  * to set the gss context. The actual exchange of an old context
 111  * and a new one is protected by the inode->i_lock.
 112  */
 113 static void
 114 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 115 {
 116         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 117         struct gss_cl_ctx *old;
 118
 119         old = gss_cred->gc_ctx;
 120         gss_get_ctx(ctx);
 121         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 122         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 123         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 124         if (old)
 125                 gss_put_ctx(old);
 126 }
 127
 128 static int
 129 gss_cred_is_uptodate_ctx(struct rpc_cred *cred)
 130 {
 131         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 132         int res = 0;
 133
 134         rcu_read_lock();
 135         if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) && gss_cred->gc_ctx)
 136                 res = 1;
 137         rcu_read_unlock();
 138         return res;
 139 }
 140
 141 static const void *
 142 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 143 {
 144         const void *q = (const void *)((const char *)p + len);
 145         if (unlikely(q > end || q < p))
 146                 return ERR_PTR(-EFAULT);
 147         memcpy(res, p, len);
 148         return q;
 149 }
 150
 151 static inline const void *
 152 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 153 {
 154         const void *q;
 155         unsigned int len;
 156
 157         p = simple_get_bytes(p, end, &len, sizeof(len));
 158         if (IS_ERR(p))
 159                 return p;
 160         q = (const void *)((const char *)p + len);
 161         if (unlikely(q > end || q < p))
 162                 return ERR_PTR(-EFAULT);
 163         dest->data = kmemdup(p, len, GFP_KERNEL);
 164         if (unlikely(dest->data == NULL))
 165                 return ERR_PTR(-ENOMEM);
 166         dest->len = len;
 167         return q;
 168 }
 169
 170 static struct gss_cl_ctx *
 171 gss_cred_get_ctx(struct rpc_cred *cred)
 172 {
 173         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 174         struct gss_cl_ctx *ctx = NULL;
 175
 176         rcu_read_lock();
 177         if (gss_cred->gc_ctx)
 178                 ctx = gss_get_ctx(gss_cred->gc_ctx);
 179         rcu_read_unlock();
 180         return ctx;
 181 }
 182
 183 static struct gss_cl_ctx *
 184 gss_alloc_context(void)
 185 {
 186         struct gss_cl_ctx *ctx;
 187
 188         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 189         if (ctx != NULL) {
 190                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 191                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 192                 spin_lock_init(&ctx->gc_seq_lock);
 193                 atomic_set(&ctx->count,1);
 194         }
 195         return ctx;
 196 }
 197
 198 #define GSSD_MIN_TIMEOUT (60 * 60)
 199 static const void *
 200 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 201 {
 202         const void *q;
 203         unsigned int seclen;
 204         unsigned int timeout;
 205         u32 window_size;
 206         int ret;
 207
 208         /* First unsigned int gives the lifetime (in seconds) of the cred */
 209         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 210         if (IS_ERR(p))
 211                 goto err;
 212         if (timeout == 0)
 213                 timeout = GSSD_MIN_TIMEOUT;
 214         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
 215         /* Sequence number window. Determines the maximum number of simultaneous requests */
 216         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 217         if (IS_ERR(p))
 218                 goto err;
 219         ctx->gc_win = window_size;
 220         /* gssd signals an error by passing ctx->gc_win = 0: */
 221         if (ctx->gc_win == 0) {
 222                 /* in which case, p points to  an error code which we ignore */
 223                 p = ERR_PTR(-EACCES);
 224                 goto err;
 225         }
 226         /* copy the opaque wire context */
 227         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 228         if (IS_ERR(p))
 229                 goto err;
 230         /* import the opaque security context */
 231         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 232         if (IS_ERR(p))
 233                 goto err;
 234         q = (const void *)((const char *)p + seclen);
 235         if (unlikely(q > end || q < p)) {
 236                 p = ERR_PTR(-EFAULT);
 237                 goto err;
 238         }
 239         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
 240         if (ret < 0) {
 241                 p = ERR_PTR(ret);
 242                 goto err;
 243         }
 244         return q;
 245 err:
 246         dprintk("RPC:       gss_fill_context returning %ld\n", -PTR_ERR(p));
 247         return p;
 248 }
 249
 250
 251 struct gss_upcall_msg {
 252         atomic_t count;
 253         uid_t   uid;
 254         struct rpc_pipe_msg msg;
 255         struct list_head list;
 256         struct gss_auth *auth;
 257         struct rpc_wait_queue rpc_waitqueue;
 258         wait_queue_head_t waitqueue;
 259         struct gss_cl_ctx *ctx;
 260 };
 261
 262 static void
 263 gss_release_msg(struct gss_upcall_msg *gss_msg)
 264 {
 265         if (!atomic_dec_and_test(&gss_msg->count))
 266                 return;
 267         BUG_ON(!list_empty(&gss_msg->list));
 268         if (gss_msg->ctx != NULL)
 269                 gss_put_ctx(gss_msg->ctx);
 270         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 271         kfree(gss_msg);
 272 }
 273
 274 static struct gss_upcall_msg *
 275 __gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
 276 {
 277         struct gss_upcall_msg *pos;
 278         list_for_each_entry(pos, &rpci->in_downcall, list) {
 279                 if (pos->uid != uid)
 280                         continue;
 281                 atomic_inc(&pos->count);
 282                 dprintk("RPC:       gss_find_upcall found msg %p\n", pos);
 283                 return pos;
 284         }
 285         dprintk("RPC:       gss_find_upcall found nothing\n");
 286         return NULL;
 287 }
 288
 289 /* Try to add a upcall to the pipefs queue.
 290  * If an upcall owned by our uid already exists, then we return a reference
 291  * to that upcall instead of adding the new upcall.
 292  */
 293 static inline struct gss_upcall_msg *
 294 gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
 295 {
 296         struct inode *inode = gss_auth->dentry->d_inode;
 297         struct rpc_inode *rpci = RPC_I(inode);
 298         struct gss_upcall_msg *old;
 299
 300         spin_lock(&inode->i_lock);
 301         old = __gss_find_upcall(rpci, gss_msg->uid);
 302         if (old == NULL) {
 303                 atomic_inc(&gss_msg->count);
 304                 list_add(&gss_msg->list, &rpci->in_downcall);
 305         } else
 306                 gss_msg = old;
 307         spin_unlock(&inode->i_lock);
 308         return gss_msg;
 309 }
 310
 311 static void
 312 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 313 {
 314         list_del_init(&gss_msg->list);
 315         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 316         wake_up_all(&gss_msg->waitqueue);
 317         atomic_dec(&gss_msg->count);
 318 }
 319
 320 static void
 321 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 322 {
 323         struct gss_auth *gss_auth = gss_msg->auth;
 324         struct inode *inode = gss_auth->dentry->d_inode;
 325
 326         if (list_empty(&gss_msg->list))
 327                 return;
 328         spin_lock(&inode->i_lock);
 329         if (!list_empty(&gss_msg->list))
 330                 __gss_unhash_msg(gss_msg);
 331         spin_unlock(&inode->i_lock);
 332 }
 333
 334 static void
 335 gss_upcall_callback(struct rpc_task *task)
 336 {
 337         struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
 338                         struct gss_cred, gc_base);
 339         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 340         struct inode *inode = gss_msg->auth->dentry->d_inode;
 341
 342         spin_lock(&inode->i_lock);
 343         if (gss_msg->ctx)
 344                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
 345         else
 346                 task->tk_status = gss_msg->msg.errno;
 347         gss_cred->gc_upcall = NULL;
 348         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 349         spin_unlock(&inode->i_lock);
 350         gss_release_msg(gss_msg);
 351 }
 352
 353 static inline struct gss_upcall_msg *
 354 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid)
 355 {
 356         struct gss_upcall_msg *gss_msg;
 357
 358         gss_msg = kzalloc(sizeof(*gss_msg), GFP_KERNEL);
 359         if (gss_msg != NULL) {
 360                 INIT_LIST_HEAD(&gss_msg->list);
 361                 rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 362                 init_waitqueue_head(&gss_msg->waitqueue);
 363                 atomic_set(&gss_msg->count, 1);
 364                 gss_msg->msg.data = &gss_msg->uid;
 365                 gss_msg->msg.len = sizeof(gss_msg->uid);
 366                 gss_msg->uid = uid;
 367                 gss_msg->auth = gss_auth;
 368         }
 369         return gss_msg;
 370 }
 371
 372 static struct gss_upcall_msg *
 373 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
 374 {
 375         struct gss_cred *gss_cred = container_of(cred,
 376                         struct gss_cred, gc_base);
 377         struct gss_upcall_msg *gss_new, *gss_msg;
 378         uid_t uid = cred->cr_uid;
 379
 380         /* Special case: rpc.gssd assumes that uid == 0 implies machine creds */
 381         if (gss_cred->gc_machine_cred != 0)
 382                 uid = 0;
 383
 384         gss_new = gss_alloc_msg(gss_auth, uid);
 385         if (gss_new == NULL)
 386                 return ERR_PTR(-ENOMEM);
 387         gss_msg = gss_add_msg(gss_auth, gss_new);
 388         if (gss_msg == gss_new) {
 389                 int res = rpc_queue_upcall(gss_auth->dentry->d_inode, &gss_new->msg);
 390                 if (res) {
 391                         gss_unhash_msg(gss_new);
 392                         gss_msg = ERR_PTR(res);
 393                 }
 394         } else
 395                 gss_release_msg(gss_new);
 396         return gss_msg;
 397 }
 398
 399 static inline int
 400 gss_refresh_upcall(struct rpc_task *task)
 401 {
 402         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 403         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 404                         struct gss_auth, rpc_auth);
 405         struct gss_cred *gss_cred = container_of(cred,
 406                         struct gss_cred, gc_base);
 407         struct gss_upcall_msg *gss_msg;
 408         struct inode *inode = gss_auth->dentry->d_inode;
 409         int err = 0;
 410
 411         dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
 412                                                                 cred->cr_uid);
 413         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
 414         if (IS_ERR(gss_msg)) {
 415                 err = PTR_ERR(gss_msg);
 416                 goto out;
 417         }
 418         spin_lock(&inode->i_lock);
 419         if (gss_cred->gc_upcall != NULL)
 420                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 421         else if (gss_msg->ctx != NULL) {
 422                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
 423                 gss_cred->gc_upcall = NULL;
 424                 rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 425         } else if (gss_msg->msg.errno >= 0) {
 426                 task->tk_timeout = 0;
 427                 gss_cred->gc_upcall = gss_msg;
 428                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 429                 atomic_inc(&gss_msg->count);
 430                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 431         } else
 432                 err = gss_msg->msg.errno;
 433         spin_unlock(&inode->i_lock);
 434         gss_release_msg(gss_msg);
 435 out:
 436         dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
 437                         task->tk_pid, cred->cr_uid, err);
 438         return err;
 439 }
 440
 441 static inline int
 442 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 443 {
 444         struct inode *inode = gss_auth->dentry->d_inode;
 445         struct rpc_cred *cred = &gss_cred->gc_base;
 446         struct gss_upcall_msg *gss_msg;
 447         DEFINE_WAIT(wait);
 448         int err = 0;
 449
 450         dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
 451         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 452         if (IS_ERR(gss_msg)) {
 453                 err = PTR_ERR(gss_msg);
 454                 goto out;
 455         }
 456         for (;;) {
 457                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
 458                 spin_lock(&inode->i_lock);
 459                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 460                         break;
 461                 }
 462                 spin_unlock(&inode->i_lock);
 463                 if (signalled()) {
 464                         err = -ERESTARTSYS;
 465                         goto out_intr;
 466                 }
 467                 schedule();
 468         }
 469         if (gss_msg->ctx)
 470                 gss_cred_set_ctx(cred, gss_msg->ctx);
 471         else
 472                 err = gss_msg->msg.errno;
 473         spin_unlock(&inode->i_lock);
 474 out_intr:
 475         finish_wait(&gss_msg->waitqueue, &wait);
 476         gss_release_msg(gss_msg);
 477 out:
 478         dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
 479                         cred->cr_uid, err);
 480         return err;
 481 }
 482
 483 static ssize_t
 484 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 485                 char __user *dst, size_t buflen)
 486 {
 487         char *data = (char *)msg->data + msg->copied;
 488         size_t mlen = min(msg->len, buflen);
 489         unsigned long left;
 490
 491         left = copy_to_user(dst, data, mlen);
 492         if (left == mlen) {
 493                 msg->errno = -EFAULT;
 494                 return -EFAULT;
 495         }
 496
 497         mlen -= left;
 498         msg->copied += mlen;
 499         msg->errno = 0;
 500         return mlen;
 501 }
 502
 503 #define MSG_BUF_MAXSIZE 1024
 504
 505 static ssize_t
 506 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 507 {
 508         const void *p, *end;
 509         void *buf;
 510         struct rpc_clnt *clnt;
 511         struct gss_upcall_msg *gss_msg;
 512         struct inode *inode = filp->f_path.dentry->d_inode;
 513         struct gss_cl_ctx *ctx;
 514         uid_t uid;
 515         ssize_t err = -EFBIG;
 516
 517         if (mlen > MSG_BUF_MAXSIZE)
 518                 goto out;
 519         err = -ENOMEM;
 520         buf = kmalloc(mlen, GFP_KERNEL);
 521         if (!buf)
 522                 goto out;
 523
 524         clnt = RPC_I(inode)->private;
 525         err = -EFAULT;
 526         if (copy_from_user(buf, src, mlen))
 527                 goto err;
 528
 529         end = (const void *)((char *)buf + mlen);
 530         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
 531         if (IS_ERR(p)) {
 532                 err = PTR_ERR(p);
 533                 goto err;
 534         }
 535
 536         err = -ENOMEM;
 537         ctx = gss_alloc_context();
 538         if (ctx == NULL)
 539                 goto err;
 540
 541         err = -ENOENT;
 542         /* Find a matching upcall */
 543         spin_lock(&inode->i_lock);
 544         gss_msg = __gss_find_upcall(RPC_I(inode), uid);
 545         if (gss_msg == NULL) {
 546                 spin_unlock(&inode->i_lock);
 547                 goto err_put_ctx;
 548         }
 549         list_del_init(&gss_msg->list);
 550         spin_unlock(&inode->i_lock);
 551
 552         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 553         if (IS_ERR(p)) {
 554                 err = PTR_ERR(p);
 555                 gss_msg->msg.errno = (err == -EAGAIN) ? -EAGAIN : -EACCES;
 556                 goto err_release_msg;
 557         }
 558         gss_msg->ctx = gss_get_ctx(ctx);
 559         err = mlen;
 560
 561 err_release_msg:
 562         spin_lock(&inode->i_lock);
 563         __gss_unhash_msg(gss_msg);
 564         spin_unlock(&inode->i_lock);
 565         gss_release_msg(gss_msg);
 566 err_put_ctx:
 567         gss_put_ctx(ctx);
 568 err:
 569         kfree(buf);
 570 out:
 571         dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
 572         return err;
 573 }
 574
 575 static void
 576 gss_pipe_release(struct inode *inode)
 577 {
 578         struct rpc_inode *rpci = RPC_I(inode);
 579         struct gss_upcall_msg *gss_msg;
 580
 581         spin_lock(&inode->i_lock);
 582         while (!list_empty(&rpci->in_downcall)) {
 583
 584                 gss_msg = list_entry(rpci->in_downcall.next,
 585                                 struct gss_upcall_msg, list);
 586                 gss_msg->msg.errno = -EPIPE;
 587                 atomic_inc(&gss_msg->count);
 588                 __gss_unhash_msg(gss_msg);
 589                 spin_unlock(&inode->i_lock);
 590                 gss_release_msg(gss_msg);
 591                 spin_lock(&inode->i_lock);
 592         }
 593         spin_unlock(&inode->i_lock);
 594 }
 595
 596 static void
 597 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 598 {
 599         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 600         static unsigned long ratelimit;
 601
 602         if (msg->errno < 0) {
 603                 dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
 604                                 gss_msg);
 605                 atomic_inc(&gss_msg->count);
 606                 gss_unhash_msg(gss_msg);
 607                 if (msg->errno == -ETIMEDOUT) {
 608                         unsigned long now = jiffies;
 609                         if (time_after(now, ratelimit)) {
 610                                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 611                                                     "Please check user daemon is running!\n");
 612                                 ratelimit = now + 15*HZ;
 613                         }
 614                 }
 615                 gss_release_msg(gss_msg);
 616         }
 617 }
 618
 619 /*
 620  * NOTE: we have the opportunity to use different
 621  * parameters based on the input flavor (which must be a pseudoflavor)
 622  */
 623 static struct rpc_auth *
 624 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 625 {
 626         struct gss_auth *gss_auth;
 627         struct rpc_auth * auth;
 628         int err = -ENOMEM; /* XXX? */
 629
 630         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 631
 632         if (!try_module_get(THIS_MODULE))
 633                 return ERR_PTR(err);
 634         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 635                 goto out_dec;
 636         gss_auth->client = clnt;
 637         err = -EINVAL;
 638         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 639         if (!gss_auth->mech) {
 640                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
 641                                 __FUNCTION__, flavor);
 642                 goto err_free;
 643         }
 644         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 645         if (gss_auth->service == 0)
 646                 goto err_put_mech;
 647         auth = &gss_auth->rpc_auth;
 648         auth->au_cslack = GSS_CRED_SLACK >> 2;
 649         auth->au_rslack = GSS_VERF_SLACK >> 2;
 650         auth->au_ops = &authgss_ops;
 651         auth->au_flavor = flavor;
 652         atomic_set(&auth->au_count, 1);
 653         kref_init(&gss_auth->kref);
 654
 655         gss_auth->dentry = rpc_mkpipe(clnt->cl_dentry, gss_auth->mech->gm_name,
 656                         clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 657         if (IS_ERR(gss_auth->dentry)) {
 658                 err = PTR_ERR(gss_auth->dentry);
 659                 goto err_put_mech;
 660         }
 661
 662         err = rpcauth_init_credcache(auth);
 663         if (err)
 664                 goto err_unlink_pipe;
 665
 666         return auth;
 667 err_unlink_pipe:
 668         rpc_unlink(gss_auth->dentry);
 669 err_put_mech:
 670         gss_mech_put(gss_auth->mech);
 671 err_free:
 672         kfree(gss_auth);
 673 out_dec:
 674         module_put(THIS_MODULE);
 675         return ERR_PTR(err);
 676 }
 677
 678 static void
 679 gss_free(struct gss_auth *gss_auth)
 680 {
 681         rpc_unlink(gss_auth->dentry);
 682         gss_auth->dentry = NULL;
 683         gss_mech_put(gss_auth->mech);
 684
 685         kfree(gss_auth);
 686         module_put(THIS_MODULE);
 687 }
 688
 689 static void
 690 gss_free_callback(struct kref *kref)
 691 {
 692         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
 693
 694         gss_free(gss_auth);
 695 }
 696
 697 static void
 698 gss_destroy(struct rpc_auth *auth)
 699 {
 700         struct gss_auth *gss_auth;
 701
 702         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
 703                         auth, auth->au_flavor);
 704
 705         rpcauth_destroy_credcache(auth);
 706
 707         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 708         kref_put(&gss_auth->kref, gss_free_callback);
 709 }
 710
 711 /*
 712  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
 713  * to the server with the GSS control procedure field set to
 714  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
 715  * all RPCSEC_GSS state associated with that context.
 716  */
 717 static int
 718 gss_destroying_context(struct rpc_cred *cred)
 719 {
 720         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 721         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 722         struct rpc_task *task;
 723
 724         if (gss_cred->gc_ctx == NULL ||
 725             test_and_clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 726                 return 0;
 727
 728         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
 729         cred->cr_ops = &gss_nullops;
 730
 731         /* Take a reference to ensure the cred will be destroyed either
 732          * by the RPC call or by the put_rpccred() below */
 733         get_rpccred(cred);
 734
 735         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
 736         if (!IS_ERR(task))
 737                 rpc_put_task(task);
 738
 739         put_rpccred(cred);
 740         return 1;
 741 }
 742
 743 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
 744  * to create a new cred or context, so they check that things have been
 745  * allocated before freeing them. */
 746 static void
 747 gss_do_free_ctx(struct gss_cl_ctx *ctx)
 748 {
 749         dprintk("RPC:       gss_free_ctx\n");
 750
 751         kfree(ctx->gc_wire_ctx.data);
 752         kfree(ctx);
 753 }
 754
 755 static void
 756 gss_free_ctx_callback(struct rcu_head *head)
 757 {
 758         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
 759         gss_do_free_ctx(ctx);
 760 }
 761
 762 static void
 763 gss_free_ctx(struct gss_cl_ctx *ctx)
 764 {
 765         struct gss_ctx *gc_gss_ctx;
 766
 767         gc_gss_ctx = rcu_dereference(ctx->gc_gss_ctx);
 768         rcu_assign_pointer(ctx->gc_gss_ctx, NULL);
 769         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
 770         if (gc_gss_ctx)
 771                 gss_delete_sec_context(&gc_gss_ctx);
 772 }
 773
 774 static void
 775 gss_free_cred(struct gss_cred *gss_cred)
 776 {
 777         dprintk("RPC:       gss_free_cred %p\n", gss_cred);
 778         kfree(gss_cred);
 779 }
 780
 781 static void
 782 gss_free_cred_callback(struct rcu_head *head)
 783 {
 784         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
 785         gss_free_cred(gss_cred);
 786 }
 787
 788 static void
 789 gss_destroy_cred(struct rpc_cred *cred)
 790 {
 791         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 792         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 793         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
 794
 795         if (gss_destroying_context(cred))
 796                 return;
 797         rcu_assign_pointer(gss_cred->gc_ctx, NULL);
 798         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
 799         if (ctx)
 800                 gss_put_ctx(ctx);
 801         kref_put(&gss_auth->kref, gss_free_callback);
 802 }
 803
 804 /*
 805  * Lookup RPCSEC_GSS cred for the current process
 806  */
 807 static struct rpc_cred *
 808 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 809 {
 810         return rpcauth_lookup_credcache(auth, acred, flags);
 811 }
 812
 813 static struct rpc_cred *
 814 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 815 {
 816         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 817         struct gss_cred *cred = NULL;
 818         int err = -ENOMEM;
 819
 820         dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
 821                 acred->uid, auth->au_flavor);
 822
 823         if (!(cred = kzalloc(sizeof(*cred), GFP_KERNEL)))
 824                 goto out_err;
 825
 826         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
 827         /*
 828          * Note: in order to force a call to call_refresh(), we deliberately
 829          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
 830          */
 831         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
 832         cred->gc_service = gss_auth->service;
 833         cred->gc_machine_cred = acred->machine_cred;
 834         kref_get(&gss_auth->kref);
 835         return &cred->gc_base;
 836
 837 out_err:
 838         dprintk("RPC:       gss_create_cred failed with error %d\n", err);
 839         return ERR_PTR(err);
 840 }
 841
 842 static int
 843 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
 844 {
 845         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 846         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
 847         int err;
 848
 849         do {
 850                 err = gss_create_upcall(gss_auth, gss_cred);
 851         } while (err == -EAGAIN);
 852         return err;
 853 }
 854
 855 static int
 856 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
 857 {
 858         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
 859
 860         /*
 861          * If the searchflags have set RPCAUTH_LOOKUP_NEW, then
 862          * we don't really care if the credential has expired or not,
 863          * since the caller should be prepared to reinitialise it.
 864          */
 865         if ((flags & RPCAUTH_LOOKUP_NEW) && test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
 866                 goto out;
 867         /* Don't match with creds that have expired. */
 868         if (gss_cred->gc_ctx && time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
 869                 return 0;
 870 out:
 871         if (acred->machine_cred != gss_cred->gc_machine_cred)
 872                 return 0;
 873         return (rc->cr_uid == acred->uid);
 874 }
 875
 876 /*
 877 * Marshal credentials.
 878 * Maybe we should keep a cached credential for performance reasons.
 879 */
 880 static __be32 *
 881 gss_marshal(struct rpc_task *task, __be32 *p)
 882 {
 883         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 884         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
 885                                                  gc_base);
 886         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
 887         __be32          *cred_len;
 888         struct rpc_rqst *req = task->tk_rqstp;
 889         u32             maj_stat = 0;
 890         struct xdr_netobj mic;
 891         struct kvec     iov;
 892         struct xdr_buf  verf_buf;
 893
 894         dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
 895
 896         *p++ = htonl(RPC_AUTH_GSS);
 897         cred_len = p++;
 898
 899         spin_lock(&ctx->gc_seq_lock);
 900         req->rq_seqno = ctx->gc_seq++;
 901         spin_unlock(&ctx->gc_seq_lock);
 902
 903         *p++ = htonl((u32) RPC_GSS_VERSION);
 904         *p++ = htonl((u32) ctx->gc_proc);
 905         *p++ = htonl((u32) req->rq_seqno);
 906         *p++ = htonl((u32) gss_cred->gc_service);
 907         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
 908         *cred_len = htonl((p - (cred_len + 1)) << 2);
 909
 910         /* We compute the checksum for the verifier over the xdr-encoded bytes
 911          * starting with the xid and ending at the end of the credential: */
 912         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
 913                                         req->rq_snd_buf.head[0].iov_base);
 914         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
 915         xdr_buf_from_iov(&iov, &verf_buf);
 916
 917         /* set verifier flavor*/
 918         *p++ = htonl(RPC_AUTH_GSS);
 919
 920         mic.data = (u8 *)(p + 1);
 921         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 922         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
 923                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 924         } else if (maj_stat != 0) {
 925                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
 926                 goto out_put_ctx;
 927         }
 928         p = xdr_encode_opaque(p, NULL, mic.len);
 929         gss_put_ctx(ctx);
 930         return p;
 931 out_put_ctx:
 932         gss_put_ctx(ctx);
 933         return NULL;
 934 }
 935
 936 /*
 937 * Refresh credentials. XXX - finish
 938 */
 939 static int
 940 gss_refresh(struct rpc_task *task)
 941 {
 942
 943         if (!gss_cred_is_uptodate_ctx(task->tk_msg.rpc_cred))
 944                 return gss_refresh_upcall(task);
 945         return 0;
 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)