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