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