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/smp_lock.h>
  47 #include <linux/pagemap.h>
  48 #include <linux/sunrpc/clnt.h>
  49 #include <linux/sunrpc/auth.h>
  50 #include <linux/sunrpc/auth_gss.h>
  51 #include <linux/sunrpc/svcauth_gss.h>
  52 #include <linux/sunrpc/gss_err.h>
  53 #include <linux/workqueue.h>
  54 #include <linux/sunrpc/rpc_pipe_fs.h>
  55 #include <linux/sunrpc/gss_api.h>
  56 #include <asm/uaccess.h>
  57
  58 static const struct rpc_authops authgss_ops;
  59
  60 static const struct rpc_credops gss_credops;
  61 static const struct rpc_credops gss_nullops;
  62
  63 #ifdef RPC_DEBUG
  64 # define RPCDBG_FACILITY        RPCDBG_AUTH
  65 #endif
  66
  67 #define NFS_NGROUPS     16
  68
  69 #define GSS_CRED_SLACK          1024            /* XXX: unused */
  70 /* length of a krb5 verifier (48), plus data added before arguments when
  71  * using integrity (two 4-byte integers): */
  72 #define GSS_VERF_SLACK          100
  73
  74 /* XXX this define must match the gssd define
  75 * as it is passed to gssd to signal the use of
  76 * machine creds should be part of the shared rpc interface */
  77
  78 #define CA_RUN_AS_MACHINE  0x00000200
  79
  80 /* dump the buffer in `emacs-hexl' style */
  81 #define isprint(c)      ((c > 0x1f) && (c < 0x7f))
  82
  83 struct gss_auth {
  84         struct kref kref;
  85         struct rpc_auth rpc_auth;
  86         struct gss_api_mech *mech;
  87         enum rpc_gss_svc service;
  88         struct rpc_clnt *client;
  89         struct dentry *dentry;
  90 };
  91
  92 static void gss_free_ctx(struct gss_cl_ctx *);
  93 static struct rpc_pipe_ops gss_upcall_ops;
  94
  95 static inline struct gss_cl_ctx *
  96 gss_get_ctx(struct gss_cl_ctx *ctx)
  97 {
  98         atomic_inc(&ctx->count);
  99         return ctx;
 100 }
 101
 102 static inline void
 103 gss_put_ctx(struct gss_cl_ctx *ctx)
 104 {
 105         if (atomic_dec_and_test(&ctx->count))
 106                 gss_free_ctx(ctx);
 107 }
 108
 109 /* gss_cred_set_ctx:
 110  * called by gss_upcall_callback and gss_create_upcall in order
 111  * to set the gss context. The actual exchange of an old context
 112  * and a new one is protected by the inode->i_lock.
 113  */
 114 static void
 115 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 116 {
 117         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 118         struct gss_cl_ctx *old;
 119
 120         old = gss_cred->gc_ctx;
 121         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 122         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 123         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 124         if (old)
 125                 gss_put_ctx(old);
 126 }
 127
 128 static int
 129 gss_cred_is_uptodate_ctx(struct rpc_cred *cred)
 130 {
 131         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 132         int res = 0;
 133
 134         rcu_read_lock();
 135         if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) && gss_cred->gc_ctx)
 136                 res = 1;
 137         rcu_read_unlock();
 138         return res;
 139 }
 140
 141 static const void *
 142 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 143 {
 144         const void *q = (const void *)((const char *)p + len);
 145         if (unlikely(q > end || q < p))
 146                 return ERR_PTR(-EFAULT);
 147         memcpy(res, p, len);
 148         return q;
 149 }
 150
 151 static inline const void *
 152 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 153 {
 154         const void *q;
 155         unsigned int len;
 156
 157         p = simple_get_bytes(p, end, &len, sizeof(len));
 158         if (IS_ERR(p))
 159                 return p;
 160         q = (const void *)((const char *)p + len);
 161         if (unlikely(q > end || q < p))
 162                 return ERR_PTR(-EFAULT);
 163         dest->data = kmemdup(p, len, GFP_KERNEL);
 164         if (unlikely(dest->data == NULL))
 165                 return ERR_PTR(-ENOMEM);
 166         dest->len = len;
 167         return q;
 168 }
 169
 170 static struct gss_cl_ctx *
 171 gss_cred_get_ctx(struct rpc_cred *cred)
 172 {
 173         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 174         struct gss_cl_ctx *ctx = NULL;
 175
 176         rcu_read_lock();
 177         if (gss_cred->gc_ctx)
 178                 ctx = gss_get_ctx(gss_cred->gc_ctx);
 179         rcu_read_unlock();
 180         return ctx;
 181 }
 182
 183 static struct gss_cl_ctx *
 184 gss_alloc_context(void)
 185 {
 186         struct gss_cl_ctx *ctx;
 187
 188         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 189         if (ctx != NULL) {
 190                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 191                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 192                 spin_lock_init(&ctx->gc_seq_lock);
 193                 atomic_set(&ctx->count,1);
 194         }
 195         return ctx;
 196 }
 197
 198 #define GSSD_MIN_TIMEOUT (60 * 60)
 199 static const void *
 200 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 201 {
 202         const void *q;
 203         unsigned int seclen;
 204         unsigned int timeout;
 205         u32 window_size;
 206         int ret;
 207
 208         /* First unsigned int gives the lifetime (in seconds) of the cred */
 209         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 210         if (IS_ERR(p))
 211                 goto err;
 212         if (timeout == 0)
 213                 timeout = GSSD_MIN_TIMEOUT;
 214         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
 215         /* Sequence number window. Determines the maximum number of simultaneous requests */
 216         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 217         if (IS_ERR(p))
 218                 goto err;
 219         ctx->gc_win = window_size;
 220         /* gssd signals an error by passing ctx->gc_win = 0: */
 221         if (ctx->gc_win == 0) {
 222                 /* in which case, p points to  an error code which we ignore */
 223                 p = ERR_PTR(-EACCES);
 224                 goto err;
 225         }
 226         /* copy the opaque wire context */
 227         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 228         if (IS_ERR(p))
 229                 goto err;
 230         /* import the opaque security context */
 231         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 232         if (IS_ERR(p))
 233                 goto err;
 234         q = (const void *)((const char *)p + seclen);
 235         if (unlikely(q > end || q < p)) {
 236                 p = ERR_PTR(-EFAULT);
 237                 goto err;
 238         }
 239         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
 240         if (ret < 0) {
 241                 p = ERR_PTR(ret);
 242                 goto err;
 243         }
 244         return q;
 245 err:
 246         dprintk("RPC:       gss_fill_context returning %ld\n", -PTR_ERR(p));
 247         return p;
 248 }
 249
 250
 251 struct gss_upcall_msg {
 252         atomic_t count;
 253         uid_t   uid;
 254         struct rpc_pipe_msg msg;
 255         struct list_head list;
 256         struct gss_auth *auth;
 257         struct rpc_wait_queue rpc_waitqueue;
 258         wait_queue_head_t waitqueue;
 259         struct gss_cl_ctx *ctx;
 260 };
 261
 262 static void
 263 gss_release_msg(struct gss_upcall_msg *gss_msg)
 264 {
 265         if (!atomic_dec_and_test(&gss_msg->count))
 266                 return;
 267         BUG_ON(!list_empty(&gss_msg->list));
 268         if (gss_msg->ctx != NULL)
 269                 gss_put_ctx(gss_msg->ctx);
 270         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_upcall_msg *gss_new, *gss_msg;
 375
 376         gss_new = gss_alloc_msg(gss_auth, cred->cr_uid);
 377         if (gss_new == NULL)
 378                 return ERR_PTR(-ENOMEM);
 379         gss_msg = gss_add_msg(gss_auth, gss_new);
 380         if (gss_msg == gss_new) {
 381                 int res = rpc_queue_upcall(gss_auth->dentry->d_inode, &gss_new->msg);
 382                 if (res) {
 383                         gss_unhash_msg(gss_new);
 384                         gss_msg = ERR_PTR(res);
 385                 }
 386         } else
 387                 gss_release_msg(gss_new);
 388         return gss_msg;
 389 }
 390
 391 static inline int
 392 gss_refresh_upcall(struct rpc_task *task)
 393 {
 394         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 395         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 396                         struct gss_auth, rpc_auth);
 397         struct gss_cred *gss_cred = container_of(cred,
 398                         struct gss_cred, gc_base);
 399         struct gss_upcall_msg *gss_msg;
 400         struct inode *inode = gss_auth->dentry->d_inode;
 401         int err = 0;
 402
 403         dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
 404                                                                 cred->cr_uid);
 405         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
 406         if (IS_ERR(gss_msg)) {
 407                 err = PTR_ERR(gss_msg);
 408                 goto out;
 409         }
 410         spin_lock(&inode->i_lock);
 411         if (gss_cred->gc_upcall != NULL)
 412                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL, NULL);
 413         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 414                 task->tk_timeout = 0;
 415                 gss_cred->gc_upcall = gss_msg;
 416                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 417                 atomic_inc(&gss_msg->count);
 418                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback, NULL);
 419         } else
 420                 err = gss_msg->msg.errno;
 421         spin_unlock(&inode->i_lock);
 422         gss_release_msg(gss_msg);
 423 out:
 424         dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
 425                         task->tk_pid, cred->cr_uid, err);
 426         return err;
 427 }
 428
 429 static inline int
 430 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 431 {
 432         struct inode *inode = gss_auth->dentry->d_inode;
 433         struct rpc_cred *cred = &gss_cred->gc_base;
 434         struct gss_upcall_msg *gss_msg;
 435         DEFINE_WAIT(wait);
 436         int err = 0;
 437
 438         dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
 439         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 440         if (IS_ERR(gss_msg)) {
 441                 err = PTR_ERR(gss_msg);
 442                 goto out;
 443         }
 444         for (;;) {
 445                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
 446                 spin_lock(&inode->i_lock);
 447                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 448                         break;
 449                 }
 450                 spin_unlock(&inode->i_lock);
 451                 if (signalled()) {
 452                         err = -ERESTARTSYS;
 453                         goto out_intr;
 454                 }
 455                 schedule();
 456         }
 457         if (gss_msg->ctx)
 458                 gss_cred_set_ctx(cred, gss_get_ctx(gss_msg->ctx));
 459         else
 460                 err = gss_msg->msg.errno;
 461         spin_unlock(&inode->i_lock);
 462 out_intr:
 463         finish_wait(&gss_msg->waitqueue, &wait);
 464         gss_release_msg(gss_msg);
 465 out:
 466         dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
 467                         cred->cr_uid, err);
 468         return err;
 469 }
 470
 471 static ssize_t
 472 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 473                 char __user *dst, size_t buflen)
 474 {
 475         char *data = (char *)msg->data + msg->copied;
 476         ssize_t mlen = msg->len;
 477         ssize_t left;
 478
 479         if (mlen > buflen)
 480                 mlen = buflen;
 481         left = copy_to_user(dst, data, mlen);
 482         if (left < 0) {
 483                 msg->errno = left;
 484                 return left;
 485         }
 486         mlen -= left;
 487         msg->copied += mlen;
 488         msg->errno = 0;
 489         return mlen;
 490 }
 491
 492 #define MSG_BUF_MAXSIZE 1024
 493
 494 static ssize_t
 495 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 496 {
 497         const void *p, *end;
 498         void *buf;
 499         struct rpc_clnt *clnt;
 500         struct gss_upcall_msg *gss_msg;
 501         struct inode *inode = filp->f_path.dentry->d_inode;
 502         struct gss_cl_ctx *ctx;
 503         uid_t uid;
 504         ssize_t err = -EFBIG;
 505
 506         if (mlen > MSG_BUF_MAXSIZE)
 507                 goto out;
 508         err = -ENOMEM;
 509         buf = kmalloc(mlen, GFP_KERNEL);
 510         if (!buf)
 511                 goto out;
 512
 513         clnt = RPC_I(inode)->private;
 514         err = -EFAULT;
 515         if (copy_from_user(buf, src, mlen))
 516                 goto err;
 517
 518         end = (const void *)((char *)buf + mlen);
 519         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
 520         if (IS_ERR(p)) {
 521                 err = PTR_ERR(p);
 522                 goto err;
 523         }
 524
 525         err = -ENOMEM;
 526         ctx = gss_alloc_context();
 527         if (ctx == NULL)
 528                 goto err;
 529
 530         err = -ENOENT;
 531         /* Find a matching upcall */
 532         spin_lock(&inode->i_lock);
 533         gss_msg = __gss_find_upcall(RPC_I(inode), uid);
 534         if (gss_msg == NULL) {
 535                 spin_unlock(&inode->i_lock);
 536                 goto err_put_ctx;
 537         }
 538         list_del_init(&gss_msg->list);
 539         spin_unlock(&inode->i_lock);
 540
 541         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 542         if (IS_ERR(p)) {
 543                 err = PTR_ERR(p);
 544                 gss_msg->msg.errno = (err == -EACCES) ? -EACCES : -EAGAIN;
 545                 goto err_release_msg;
 546         }
 547         gss_msg->ctx = gss_get_ctx(ctx);
 548         err = mlen;
 549
 550 err_release_msg:
 551         spin_lock(&inode->i_lock);
 552         __gss_unhash_msg(gss_msg);
 553         spin_unlock(&inode->i_lock);
 554         gss_release_msg(gss_msg);
 555 err_put_ctx:
 556         gss_put_ctx(ctx);
 557 err:
 558         kfree(buf);
 559 out:
 560         dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
 561         return err;
 562 }
 563
 564 static void
 565 gss_pipe_release(struct inode *inode)
 566 {
 567         struct rpc_inode *rpci = RPC_I(inode);
 568         struct gss_upcall_msg *gss_msg;
 569
 570         spin_lock(&inode->i_lock);
 571         while (!list_empty(&rpci->in_downcall)) {
 572
 573                 gss_msg = list_entry(rpci->in_downcall.next,
 574                                 struct gss_upcall_msg, list);
 575                 gss_msg->msg.errno = -EPIPE;
 576                 atomic_inc(&gss_msg->count);
 577                 __gss_unhash_msg(gss_msg);
 578                 spin_unlock(&inode->i_lock);
 579                 gss_release_msg(gss_msg);
 580                 spin_lock(&inode->i_lock);
 581         }
 582         spin_unlock(&inode->i_lock);
 583 }
 584
 585 static void
 586 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 587 {
 588         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 589         static unsigned long ratelimit;
 590
 591         if (msg->errno < 0) {
 592                 dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
 593                                 gss_msg);
 594                 atomic_inc(&gss_msg->count);
 595                 gss_unhash_msg(gss_msg);
 596                 if (msg->errno == -ETIMEDOUT) {
 597                         unsigned long now = jiffies;
 598                         if (time_after(now, ratelimit)) {
 599                                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 600                                                     "Please check user daemon is running!\n");
 601                                 ratelimit = now + 15*HZ;
 602                         }
 603                 }
 604                 gss_release_msg(gss_msg);
 605         }
 606 }
 607
 608 /*
 609  * NOTE: we have the opportunity to use different
 610  * parameters based on the input flavor (which must be a pseudoflavor)
 611  */
 612 static struct rpc_auth *
 613 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 614 {
 615         struct gss_auth *gss_auth;
 616         struct rpc_auth * auth;
 617         int err = -ENOMEM; /* XXX? */
 618
 619         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 620
 621         if (!try_module_get(THIS_MODULE))
 622                 return ERR_PTR(err);
 623         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 624                 goto out_dec;
 625         gss_auth->client = clnt;
 626         err = -EINVAL;
 627         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 628         if (!gss_auth->mech) {
 629                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!",
 630                                 __FUNCTION__, flavor);
 631                 goto err_free;
 632         }
 633         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 634         if (gss_auth->service == 0)
 635                 goto err_put_mech;
 636         auth = &gss_auth->rpc_auth;
 637         auth->au_cslack = GSS_CRED_SLACK >> 2;
 638         auth->au_rslack = GSS_VERF_SLACK >> 2;
 639         auth->au_ops = &authgss_ops;
 640         auth->au_flavor = flavor;
 641         atomic_set(&auth->au_count, 1);
 642         kref_init(&gss_auth->kref);
 643
 644         gss_auth->dentry = rpc_mkpipe(clnt->cl_dentry, gss_auth->mech->gm_name,
 645                         clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 646         if (IS_ERR(gss_auth->dentry)) {
 647                 err = PTR_ERR(gss_auth->dentry);
 648                 goto err_put_mech;
 649         }
 650
 651         err = rpcauth_init_credcache(auth);
 652         if (err)
 653                 goto err_unlink_pipe;
 654
 655         return auth;
 656 err_unlink_pipe:
 657         rpc_unlink(gss_auth->dentry);
 658 err_put_mech:
 659         gss_mech_put(gss_auth->mech);
 660 err_free:
 661         kfree(gss_auth);
 662 out_dec:
 663         module_put(THIS_MODULE);
 664         return ERR_PTR(err);
 665 }
 666
 667 static void
 668 gss_free(struct gss_auth *gss_auth)
 669 {
 670         rpc_unlink(gss_auth->dentry);
 671         gss_auth->dentry = NULL;
 672         gss_mech_put(gss_auth->mech);
 673
 674         kfree(gss_auth);
 675         module_put(THIS_MODULE);
 676 }
 677
 678 static void
 679 gss_free_callback(struct kref *kref)
 680 {
 681         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
 682
 683         gss_free(gss_auth);
 684 }
 685
 686 static void
 687 gss_destroy(struct rpc_auth *auth)
 688 {
 689         struct gss_auth *gss_auth;
 690
 691         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
 692                         auth, auth->au_flavor);
 693
 694         rpcauth_destroy_credcache(auth);
 695
 696         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 697         kref_put(&gss_auth->kref, gss_free_callback);
 698 }
 699
 700 /*
 701  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
 702  * to the server with the GSS control procedure field set to
 703  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
 704  * all RPCSEC_GSS state associated with that context.
 705  */
 706 static int
 707 gss_destroying_context(struct rpc_cred *cred)
 708 {
 709         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 710         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 711         struct rpc_task *task;
 712
 713         if (gss_cred->gc_ctx == NULL ||
 714                         gss_cred->gc_ctx->gc_proc == RPC_GSS_PROC_DESTROY)
 715                 return 0;
 716
 717         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
 718         cred->cr_ops = &gss_nullops;
 719
 720         /* Take a reference to ensure the cred will be destroyed either
 721          * by the RPC call or by the put_rpccred() below */
 722         get_rpccred(cred);
 723
 724         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC);
 725         if (!IS_ERR(task))
 726                 rpc_put_task(task);
 727
 728         put_rpccred(cred);
 729         return 1;
 730 }
 731
 732 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
 733  * to create a new cred or context, so they check that things have been
 734  * allocated before freeing them. */
 735 static void
 736 gss_do_free_ctx(struct gss_cl_ctx *ctx)
 737 {
 738         dprintk("RPC:       gss_free_ctx\n");
 739
 740         if (ctx->gc_gss_ctx)
 741                 gss_delete_sec_context(&ctx->gc_gss_ctx);
 742
 743         kfree(ctx->gc_wire_ctx.data);
 744         kfree(ctx);
 745 }
 746
 747 static void
 748 gss_free_ctx_callback(struct rcu_head *head)
 749 {
 750         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
 751         gss_do_free_ctx(ctx);
 752 }
 753
 754 static void
 755 gss_free_ctx(struct gss_cl_ctx *ctx)
 756 {
 757         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
 758 }
 759
 760 static void
 761 gss_free_cred(struct gss_cred *gss_cred)
 762 {
 763         dprintk("RPC:       gss_free_cred %p\n", gss_cred);
 764         kfree(gss_cred);
 765 }
 766
 767 static void
 768 gss_free_cred_callback(struct rcu_head *head)
 769 {
 770         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
 771         gss_free_cred(gss_cred);
 772 }
 773
 774 static void
 775 gss_destroy_cred(struct rpc_cred *cred)
 776 {
 777         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 778         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 779         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
 780
 781         if (gss_destroying_context(cred))
 782                 return;
 783         rcu_assign_pointer(gss_cred->gc_ctx, NULL);
 784         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
 785         if (ctx)
 786                 gss_put_ctx(ctx);
 787         kref_put(&gss_auth->kref, gss_free_callback);
 788 }
 789
 790 /*
 791  * Lookup RPCSEC_GSS cred for the current process
 792  */
 793 static struct rpc_cred *
 794 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 795 {
 796         return rpcauth_lookup_credcache(auth, acred, flags);
 797 }
 798
 799 static struct rpc_cred *
 800 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 801 {
 802         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 803         struct gss_cred *cred = NULL;
 804         int err = -ENOMEM;
 805
 806         dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
 807                 acred->uid, auth->au_flavor);
 808
 809         if (!(cred = kzalloc(sizeof(*cred), GFP_KERNEL)))
 810                 goto out_err;
 811
 812         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
 813         /*
 814          * Note: in order to force a call to call_refresh(), we deliberately
 815          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
 816          */
 817         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
 818         cred->gc_service = gss_auth->service;
 819         kref_get(&gss_auth->kref);
 820         return &cred->gc_base;
 821
 822 out_err:
 823         dprintk("RPC:       gss_create_cred failed with error %d\n", err);
 824         return ERR_PTR(err);
 825 }
 826
 827 static int
 828 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
 829 {
 830         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 831         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
 832         int err;
 833
 834         do {
 835                 err = gss_create_upcall(gss_auth, gss_cred);
 836         } while (err == -EAGAIN);
 837         return err;
 838 }
 839
 840 static int
 841 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
 842 {
 843         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
 844
 845         /*
 846          * If the searchflags have set RPCAUTH_LOOKUP_NEW, then
 847          * we don't really care if the credential has expired or not,
 848          * since the caller should be prepared to reinitialise it.
 849          */
 850         if ((flags & RPCAUTH_LOOKUP_NEW) && test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
 851                 goto out;
 852         /* Don't match with creds that have expired. */
 853         if (gss_cred->gc_ctx && time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
 854                 return 0;
 855 out:
 856         return (rc->cr_uid == acred->uid);
 857 }
 858
 859 /*
 860 * Marshal credentials.
 861 * Maybe we should keep a cached credential for performance reasons.
 862 */
 863 static __be32 *
 864 gss_marshal(struct rpc_task *task, __be32 *p)
 865 {
 866         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 867         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
 868                                                  gc_base);
 869         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
 870         __be32          *cred_len;
 871         struct rpc_rqst *req = task->tk_rqstp;
 872         u32             maj_stat = 0;
 873         struct xdr_netobj mic;
 874         struct kvec     iov;
 875         struct xdr_buf  verf_buf;
 876
 877         dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
 878
 879         *p++ = htonl(RPC_AUTH_GSS);
 880         cred_len = p++;
 881
 882         spin_lock(&ctx->gc_seq_lock);
 883         req->rq_seqno = ctx->gc_seq++;
 884         spin_unlock(&ctx->gc_seq_lock);
 885
 886         *p++ = htonl((u32) RPC_GSS_VERSION);
 887         *p++ = htonl((u32) ctx->gc_proc);
 888         *p++ = htonl((u32) req->rq_seqno);
 889         *p++ = htonl((u32) gss_cred->gc_service);
 890         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
 891         *cred_len = htonl((p - (cred_len + 1)) << 2);
 892
 893         /* We compute the checksum for the verifier over the xdr-encoded bytes
 894          * starting with the xid and ending at the end of the credential: */
 895         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
 896                                         req->rq_snd_buf.head[0].iov_base);
 897         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
 898         xdr_buf_from_iov(&iov, &verf_buf);
 899
 900         /* set verifier flavor*/
 901         *p++ = htonl(RPC_AUTH_GSS);
 902
 903         mic.data = (u8 *)(p + 1);
 904         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 905         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
 906                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 907         } else if (maj_stat != 0) {
 908                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
 909                 goto out_put_ctx;
 910         }
 911         p = xdr_encode_opaque(p, NULL, mic.len);
 912         gss_put_ctx(ctx);
 913         return p;
 914 out_put_ctx:
 915         gss_put_ctx(ctx);
 916         return NULL;
 917 }
 918
 919 /*
 920 * Refresh credentials. XXX - finish
 921 */
 922 static int
 923 gss_refresh(struct rpc_task *task)
 924 {
 925
 926         if (!gss_cred_is_uptodate_ctx(task->tk_msg.rpc_cred))
 927                 return gss_refresh_upcall(task);
 928         return 0;
 929 }
 930
 931 /* Dummy refresh routine: used only when destroying the context */
 932 static int
 933 gss_refresh_null(struct rpc_task *task)
 934 {
 935         return -EACCES;
 936 }
 937
 938 static __be32 *
 939 gss_validate(struct rpc_task *task, __be32 *p)
 940 {
 941         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 942         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
 943         __be32          seq;
 944         struct kvec     iov;
 945         struct xdr_buf  verf_buf;
 946         struct xdr_netobj mic;
 947         u32             flav,len;
 948         u32             maj_stat;
 949
 950         dprintk("RPC: %5u gss_validate\n", task->tk_pid);
 951
 952         flav = ntohl(*p++);
 953         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
 954                 goto out_bad;
 955         if (flav != RPC_AUTH_GSS)
 956                 goto out_bad;
 957         seq = htonl(task->tk_rqstp->rq_seqno);
 958         iov.iov_base = &seq;
 959         iov.iov_len = sizeof(seq);
 960         xdr_buf_from_iov(&iov, &verf_buf);
 961         mic.data = (u8 *)p;
 962         mic.len = len;
 963
 964         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 965         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
 966                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 967         if (maj_stat) {
 968                 dprintk("RPC: %5u gss_validate: gss_verify_mic returned"
 969                                 "error 0x%08x\n", task->tk_pid, maj_stat);
 970                 goto out_bad;
 971         }
 972         /* We leave it to unwrap to calculate au_rslack. For now we just
 973          * calculate the length of the verifier: */
 974         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
 975         gss_put_ctx(ctx);
 976         dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
 977                         task->tk_pid);
 978         return p + XDR_QUADLEN(len);
 979 out_bad:
 980         gss_put_ctx(ctx);
 981         dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
 982         return NULL;
 983 }
 984
 985 static inline int
 986 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
 987                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
 988 {
 989         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
 990         struct xdr_buf  integ_buf;
 991         __be32          *integ_len = NULL;
 992         struct xdr_netobj mic;
 993         u32             offset;
 994         __be32          *q;
 995         struct kvec     *iov;
 996         u32             maj_stat = 0;
 997         int             status = -EIO;
 998
 999         integ_len = p++;
1000         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1001         *p++ = htonl(rqstp->rq_seqno);
1002
1003         lock_kernel();
1004         status = encode(rqstp, p, obj);
1005         unlock_kernel();
1006         if (status)
1007                 return status;
1008
1009         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1010                                 offset, snd_buf->len - offset))
1011                 return status;
1012         *integ_len = htonl(integ_buf.len);
1013
1014         /* guess whether we're in the head or the tail: */
1015         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1016                 iov = snd_buf->tail;
1017         else
1018                 iov = snd_buf->head;
1019         p = iov->iov_base + iov->iov_len;
1020         mic.data = (u8 *)(p + 1);
1021
1022         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1023         status = -EIO; /* XXX? */
1024         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1025                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1026         else if (maj_stat)
1027                 return status;
1028         q = xdr_encode_opaque(p, NULL, mic.len);
1029
1030         offset = (u8 *)q - (u8 *)p;
1031         iov->iov_len += offset;
1032         snd_buf->len += offset;
1033         return 0;
1034 }
1035
1036 static void
1037 priv_release_snd_buf(struct rpc_rqst *rqstp)
1038 {
1039         int i;
1040
1041         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1042                 __free_page(rqstp->rq_enc_pages[i]);
1043         kfree(rqstp->rq_enc_pages);
1044 }
1045
1046 static int
1047 alloc_enc_pages(struct rpc_rqst *rqstp)
1048 {
1049         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1050         int first, last, i;
1051
1052         if (snd_buf->page_len == 0) {
1053                 rqstp->rq_enc_pages_num = 0;
1054                 return 0;
1055         }
1056
1057         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1058         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1059         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1060         rqstp->rq_enc_pages
1061                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1062                                 GFP_NOFS);
1063         if (!rqstp->rq_enc_pages)
1064                 goto out;
1065         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1066                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1067                 if (rqstp->rq_enc_pages[i] == NULL)
1068                         goto out_free;
1069         }
1070         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1071         return 0;
1072 out_free:
1073         for (i--; i >= 0; i--) {
1074                 __free_page(rqstp->rq_enc_pages[i]);
1075         }
1076 out:
1077         return -EAGAIN;
1078 }
1079
1080 static inline int
1081 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1082                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1083 {
1084         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1085         u32             offset;
1086         u32             maj_stat;
1087         int             status;
1088         __be32          *opaque_len;
1089         struct page     **inpages;
1090         int             first;
1091         int             pad;
1092         struct kvec     *iov;
1093         char            *tmp;
1094
1095         opaque_len = p++;
1096         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1097         *p++ = htonl(rqstp->rq_seqno);
1098
1099         lock_kernel();
1100         status = encode(rqstp, p, obj);
1101         unlock_kernel();
1102         if (status)
1103                 return status;
1104
1105         status = alloc_enc_pages(rqstp);
1106         if (status)
1107                 return status;
1108         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1109         inpages = snd_buf->pages + first;
1110         snd_buf->pages = rqstp->rq_enc_pages;
1111         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1112         /* Give the tail its own page, in case we need extra space in the
1113          * head when wrapping: */
1114         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1115                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1116                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1117                 snd_buf->tail[0].iov_base = tmp;
1118         }
1119         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1120         /* RPC_SLACK_SPACE should prevent this ever happening: */
1121         BUG_ON(snd_buf->len > snd_buf->buflen);
1122         status = -EIO;
1123         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1124          * done anyway, so it's safe to put the request on the wire: */
1125         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1126                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1127         else if (maj_stat)
1128                 return status;
1129
1130         *opaque_len = htonl(snd_buf->len - offset);
1131         /* guess whether we're in the head or the tail: */
1132         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1133                 iov = snd_buf->tail;
1134         else
1135                 iov = snd_buf->head;
1136         p = iov->iov_base + iov->iov_len;
1137         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1138         memset(p, 0, pad);
1139         iov->iov_len += pad;
1140         snd_buf->len += pad;
1141
1142         return 0;
1143 }
1144
1145 static int
1146 gss_wrap_req(struct rpc_task *task,
1147              kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
1148 {
1149         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1150         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1151                         gc_base);
1152         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1153         int             status = -EIO;
1154
1155         dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
1156         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1157                 /* The spec seems a little ambiguous here, but I think that not
1158                  * wrapping context destruction requests makes the most sense.
1159                  */
1160                 lock_kernel();
1161                 status = encode(rqstp, p, obj);
1162                 unlock_kernel();
1163                 goto out;
1164         }
1165         switch (gss_cred->gc_service) {
1166                 case RPC_GSS_SVC_NONE:
1167                         lock_kernel();
1168                         status = encode(rqstp, p, obj);
1169                         unlock_kernel();
1170                         break;
1171                 case RPC_GSS_SVC_INTEGRITY:
1172                         status = gss_wrap_req_integ(cred, ctx, encode,
1173                                                                 rqstp, p, obj);
1174                         break;
1175                 case RPC_GSS_SVC_PRIVACY:
1176                         status = gss_wrap_req_priv(cred, ctx, encode,
1177                                         rqstp, p, obj);
1178                         break;
1179         }
1180 out:
1181         gss_put_ctx(ctx);
1182         dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
1183         return status;
1184 }
1185
1186 static inline int
1187 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1188                 struct rpc_rqst *rqstp, __be32 **p)
1189 {
1190         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1191         struct xdr_buf integ_buf;
1192         struct xdr_netobj mic;
1193         u32 data_offset, mic_offset;
1194         u32 integ_len;
1195         u32 maj_stat;
1196         int status = -EIO;
1197
1198         integ_len = ntohl(*(*p)++);
1199         if (integ_len & 3)
1200                 return status;
1201         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1202         mic_offset = integ_len + data_offset;
1203         if (mic_offset > rcv_buf->len)
1204                 return status;
1205         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1206                 return status;
1207
1208         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1209                                 mic_offset - data_offset))
1210                 return status;
1211
1212         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1213                 return status;
1214
1215         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1216         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1217                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1218         if (maj_stat != GSS_S_COMPLETE)
1219                 return status;
1220         return 0;
1221 }
1222
1223 static inline int
1224 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1225                 struct rpc_rqst *rqstp, __be32 **p)
1226 {
1227         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1228         u32 offset;
1229         u32 opaque_len;
1230         u32 maj_stat;
1231         int status = -EIO;
1232
1233         opaque_len = ntohl(*(*p)++);
1234         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1235         if (offset + opaque_len > rcv_buf->len)
1236                 return status;
1237         /* remove padding: */
1238         rcv_buf->len = offset + opaque_len;
1239
1240         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1241         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1242                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1243         if (maj_stat != GSS_S_COMPLETE)
1244                 return status;
1245         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1246                 return status;
1247
1248         return 0;
1249 }
1250
1251
1252 static int
1253 gss_unwrap_resp(struct rpc_task *task,
1254                 kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
1255 {
1256         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1257         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1258                         gc_base);
1259         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1260         __be32          *savedp = p;
1261         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1262         int             savedlen = head->iov_len;
1263         int             status = -EIO;
1264
1265         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1266                 goto out_decode;
1267         switch (gss_cred->gc_service) {
1268                 case RPC_GSS_SVC_NONE:
1269                         break;
1270                 case RPC_GSS_SVC_INTEGRITY:
1271                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1272                         if (status)
1273                                 goto out;
1274                         break;
1275                 case RPC_GSS_SVC_PRIVACY:
1276                         status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1277                         if (status)
1278                                 goto out;
1279                         break;
1280         }
1281         /* take into account extra slack for integrity and privacy cases: */
1282         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1283                                                 + (savedlen - head->iov_len);
1284 out_decode:
1285         lock_kernel();
1286         status = decode(rqstp, p, obj);
1287         unlock_kernel();
1288 out:
1289         gss_put_ctx(ctx);
1290         dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
1291                         status);
1292         return status;
1293 }
1294
1295 static const struct rpc_authops authgss_ops = {
1296         .owner          = THIS_MODULE,
1297         .au_flavor      = RPC_AUTH_GSS,
1298 #ifdef RPC_DEBUG
1299         .au_name        = "RPCSEC_GSS",
1300 #endif
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         .crmatch        = gss_match,
1312         .crmarshal      = gss_marshal,
1313         .crrefresh      = gss_refresh,
1314         .crvalidate     = gss_validate,
1315         .crwrap_req     = gss_wrap_req,
1316         .crunwrap_resp  = gss_unwrap_resp,
1317 };
1318
1319 static const struct rpc_credops gss_nullops = {
1320         .cr_name        = "AUTH_GSS",
1321         .crdestroy      = gss_destroy_cred,
1322         .crmatch        = gss_match,
1323         .crmarshal      = gss_marshal,
1324         .crrefresh      = gss_refresh_null,
1325         .crvalidate     = gss_validate,
1326         .crwrap_req     = gss_wrap_req,
1327         .crunwrap_resp  = gss_unwrap_resp,
1328 };
1329
1330 static struct rpc_pipe_ops gss_upcall_ops = {
1331         .upcall         = gss_pipe_upcall,
1332         .downcall       = gss_pipe_downcall,
1333         .destroy_msg    = gss_pipe_destroy_msg,
1334         .release_pipe   = gss_pipe_release,
1335 };
1336
1337 /*
1338  * Initialize RPCSEC_GSS module
1339  */
1340 static int __init init_rpcsec_gss(void)
1341 {
1342         int err = 0;
1343
1344         err = rpcauth_register(&authgss_ops);
1345         if (err)
1346                 goto out;
1347         err = gss_svc_init();
1348         if (err)
1349                 goto out_unregister;
1350         return 0;
1351 out_unregister:
1352         rpcauth_unregister(&authgss_ops);
1353 out:
1354         return err;
1355 }
1356
1357 static void __exit exit_rpcsec_gss(void)
1358 {
1359         gss_svc_shutdown();
1360         rpcauth_unregister(&authgss_ops);
1361 }
1362
1363 MODULE_LICENSE("GPL");
1364 module_init(init_rpcsec_gss)
1365 module_exit(exit_rpcsec_gss)