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
 118         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 119                 return;
 120         gss_get_ctx(ctx);
 121         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 122         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 123         smp_mb__before_clear_bit();
 124         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 125 }
 126
 127 static const void *
 128 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 129 {
 130         const void *q = (const void *)((const char *)p + len);
 131         if (unlikely(q > end || q < p))
 132                 return ERR_PTR(-EFAULT);
 133         memcpy(res, p, len);
 134         return q;
 135 }
 136
 137 static inline const void *
 138 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 139 {
 140         const void *q;
 141         unsigned int len;
 142
 143         p = simple_get_bytes(p, end, &len, sizeof(len));
 144         if (IS_ERR(p))
 145                 return p;
 146         q = (const void *)((const char *)p + len);
 147         if (unlikely(q > end || q < p))
 148                 return ERR_PTR(-EFAULT);
 149         dest->data = kmemdup(p, len, GFP_KERNEL);
 150         if (unlikely(dest->data == NULL))
 151                 return ERR_PTR(-ENOMEM);
 152         dest->len = len;
 153         return q;
 154 }
 155
 156 static struct gss_cl_ctx *
 157 gss_cred_get_ctx(struct rpc_cred *cred)
 158 {
 159         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 160         struct gss_cl_ctx *ctx = NULL;
 161
 162         rcu_read_lock();
 163         if (gss_cred->gc_ctx)
 164                 ctx = gss_get_ctx(gss_cred->gc_ctx);
 165         rcu_read_unlock();
 166         return ctx;
 167 }
 168
 169 static struct gss_cl_ctx *
 170 gss_alloc_context(void)
 171 {
 172         struct gss_cl_ctx *ctx;
 173
 174         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 175         if (ctx != NULL) {
 176                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 177                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 178                 spin_lock_init(&ctx->gc_seq_lock);
 179                 atomic_set(&ctx->count,1);
 180         }
 181         return ctx;
 182 }
 183
 184 #define GSSD_MIN_TIMEOUT (60 * 60)
 185 static const void *
 186 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 187 {
 188         const void *q;
 189         unsigned int seclen;
 190         unsigned int timeout;
 191         u32 window_size;
 192         int ret;
 193
 194         /* First unsigned int gives the lifetime (in seconds) of the cred */
 195         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 196         if (IS_ERR(p))
 197                 goto err;
 198         if (timeout == 0)
 199                 timeout = GSSD_MIN_TIMEOUT;
 200         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
 201         /* Sequence number window. Determines the maximum number of simultaneous requests */
 202         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 203         if (IS_ERR(p))
 204                 goto err;
 205         ctx->gc_win = window_size;
 206         /* gssd signals an error by passing ctx->gc_win = 0: */
 207         if (ctx->gc_win == 0) {
 208                 /* in which case, p points to  an error code which we ignore */
 209                 p = ERR_PTR(-EACCES);
 210                 goto err;
 211         }
 212         /* copy the opaque wire context */
 213         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 214         if (IS_ERR(p))
 215                 goto err;
 216         /* import the opaque security context */
 217         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 218         if (IS_ERR(p))
 219                 goto err;
 220         q = (const void *)((const char *)p + seclen);
 221         if (unlikely(q > end || q < p)) {
 222                 p = ERR_PTR(-EFAULT);
 223                 goto err;
 224         }
 225         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
 226         if (ret < 0) {
 227                 p = ERR_PTR(ret);
 228                 goto err;
 229         }
 230         return q;
 231 err:
 232         dprintk("RPC:       gss_fill_context returning %ld\n", -PTR_ERR(p));
 233         return p;
 234 }
 235
 236
 237 struct gss_upcall_msg {
 238         atomic_t count;
 239         uid_t   uid;
 240         struct rpc_pipe_msg msg;
 241         struct list_head list;
 242         struct gss_auth *auth;
 243         struct rpc_wait_queue rpc_waitqueue;
 244         wait_queue_head_t waitqueue;
 245         struct gss_cl_ctx *ctx;
 246 };
 247
 248 static void
 249 gss_release_msg(struct gss_upcall_msg *gss_msg)
 250 {
 251         if (!atomic_dec_and_test(&gss_msg->count))
 252                 return;
 253         BUG_ON(!list_empty(&gss_msg->list));
 254         if (gss_msg->ctx != NULL)
 255                 gss_put_ctx(gss_msg->ctx);
 256         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 257         kfree(gss_msg);
 258 }
 259
 260 static struct gss_upcall_msg *
 261 __gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
 262 {
 263         struct gss_upcall_msg *pos;
 264         list_for_each_entry(pos, &rpci->in_downcall, list) {
 265                 if (pos->uid != uid)
 266                         continue;
 267                 atomic_inc(&pos->count);
 268                 dprintk("RPC:       gss_find_upcall found msg %p\n", pos);
 269                 return pos;
 270         }
 271         dprintk("RPC:       gss_find_upcall found nothing\n");
 272         return NULL;
 273 }
 274
 275 /* Try to add a upcall to the pipefs queue.
 276  * If an upcall owned by our uid already exists, then we return a reference
 277  * to that upcall instead of adding the new upcall.
 278  */
 279 static inline struct gss_upcall_msg *
 280 gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
 281 {
 282         struct inode *inode = gss_auth->dentry->d_inode;
 283         struct rpc_inode *rpci = RPC_I(inode);
 284         struct gss_upcall_msg *old;
 285
 286         spin_lock(&inode->i_lock);
 287         old = __gss_find_upcall(rpci, gss_msg->uid);
 288         if (old == NULL) {
 289                 atomic_inc(&gss_msg->count);
 290                 list_add(&gss_msg->list, &rpci->in_downcall);
 291         } else
 292                 gss_msg = old;
 293         spin_unlock(&inode->i_lock);
 294         return gss_msg;
 295 }
 296
 297 static void
 298 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 299 {
 300         list_del_init(&gss_msg->list);
 301         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 302         wake_up_all(&gss_msg->waitqueue);
 303         atomic_dec(&gss_msg->count);
 304 }
 305
 306 static void
 307 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 308 {
 309         struct gss_auth *gss_auth = gss_msg->auth;
 310         struct inode *inode = gss_auth->dentry->d_inode;
 311
 312         if (list_empty(&gss_msg->list))
 313                 return;
 314         spin_lock(&inode->i_lock);
 315         if (!list_empty(&gss_msg->list))
 316                 __gss_unhash_msg(gss_msg);
 317         spin_unlock(&inode->i_lock);
 318 }
 319
 320 static void
 321 gss_upcall_callback(struct rpc_task *task)
 322 {
 323         struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
 324                         struct gss_cred, gc_base);
 325         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 326         struct inode *inode = gss_msg->auth->dentry->d_inode;
 327
 328         spin_lock(&inode->i_lock);
 329         if (gss_msg->ctx)
 330                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
 331         else
 332                 task->tk_status = gss_msg->msg.errno;
 333         gss_cred->gc_upcall = NULL;
 334         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 335         spin_unlock(&inode->i_lock);
 336         gss_release_msg(gss_msg);
 337 }
 338
 339 static inline struct gss_upcall_msg *
 340 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid)
 341 {
 342         struct gss_upcall_msg *gss_msg;
 343
 344         gss_msg = kzalloc(sizeof(*gss_msg), GFP_KERNEL);
 345         if (gss_msg != NULL) {
 346                 INIT_LIST_HEAD(&gss_msg->list);
 347                 rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 348                 init_waitqueue_head(&gss_msg->waitqueue);
 349                 atomic_set(&gss_msg->count, 1);
 350                 gss_msg->msg.data = &gss_msg->uid;
 351                 gss_msg->msg.len = sizeof(gss_msg->uid);
 352                 gss_msg->uid = uid;
 353                 gss_msg->auth = gss_auth;
 354         }
 355         return gss_msg;
 356 }
 357
 358 static struct gss_upcall_msg *
 359 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
 360 {
 361         struct gss_cred *gss_cred = container_of(cred,
 362                         struct gss_cred, gc_base);
 363         struct gss_upcall_msg *gss_new, *gss_msg;
 364         uid_t uid = cred->cr_uid;
 365
 366         /* Special case: rpc.gssd assumes that uid == 0 implies machine creds */
 367         if (gss_cred->gc_machine_cred != 0)
 368                 uid = 0;
 369
 370         gss_new = gss_alloc_msg(gss_auth, uid);
 371         if (gss_new == NULL)
 372                 return ERR_PTR(-ENOMEM);
 373         gss_msg = gss_add_msg(gss_auth, gss_new);
 374         if (gss_msg == gss_new) {
 375                 int res = rpc_queue_upcall(gss_auth->dentry->d_inode, &gss_new->msg);
 376                 if (res) {
 377                         gss_unhash_msg(gss_new);
 378                         gss_msg = ERR_PTR(res);
 379                 }
 380         } else
 381                 gss_release_msg(gss_new);
 382         return gss_msg;
 383 }
 384
 385 static inline int
 386 gss_refresh_upcall(struct rpc_task *task)
 387 {
 388         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 389         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 390                         struct gss_auth, rpc_auth);
 391         struct gss_cred *gss_cred = container_of(cred,
 392                         struct gss_cred, gc_base);
 393         struct gss_upcall_msg *gss_msg;
 394         struct inode *inode = gss_auth->dentry->d_inode;
 395         int err = 0;
 396
 397         dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
 398                                                                 cred->cr_uid);
 399         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
 400         if (IS_ERR(gss_msg)) {
 401                 err = PTR_ERR(gss_msg);
 402                 goto out;
 403         }
 404         spin_lock(&inode->i_lock);
 405         if (gss_cred->gc_upcall != NULL)
 406                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 407         else if (gss_msg->ctx != NULL) {
 408                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
 409                 gss_cred->gc_upcall = NULL;
 410                 rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 411         } else if (gss_msg->msg.errno >= 0) {
 412                 task->tk_timeout = 0;
 413                 gss_cred->gc_upcall = gss_msg;
 414                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 415                 atomic_inc(&gss_msg->count);
 416                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 417         } else
 418                 err = gss_msg->msg.errno;
 419         spin_unlock(&inode->i_lock);
 420         gss_release_msg(gss_msg);
 421 out:
 422         dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
 423                         task->tk_pid, cred->cr_uid, err);
 424         return err;
 425 }
 426
 427 static inline int
 428 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 429 {
 430         struct inode *inode = gss_auth->dentry->d_inode;
 431         struct rpc_cred *cred = &gss_cred->gc_base;
 432         struct gss_upcall_msg *gss_msg;
 433         DEFINE_WAIT(wait);
 434         int err = 0;
 435
 436         dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
 437         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 438         if (IS_ERR(gss_msg)) {
 439                 err = PTR_ERR(gss_msg);
 440                 goto out;
 441         }
 442         for (;;) {
 443                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
 444                 spin_lock(&inode->i_lock);
 445                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 446                         break;
 447                 }
 448                 spin_unlock(&inode->i_lock);
 449                 if (signalled()) {
 450                         err = -ERESTARTSYS;
 451                         goto out_intr;
 452                 }
 453                 schedule();
 454         }
 455         if (gss_msg->ctx)
 456                 gss_cred_set_ctx(cred, gss_msg->ctx);
 457         else
 458                 err = gss_msg->msg.errno;
 459         spin_unlock(&inode->i_lock);
 460 out_intr:
 461         finish_wait(&gss_msg->waitqueue, &wait);
 462         gss_release_msg(gss_msg);
 463 out:
 464         dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
 465                         cred->cr_uid, err);
 466         return err;
 467 }
 468
 469 static ssize_t
 470 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 471                 char __user *dst, size_t buflen)
 472 {
 473         char *data = (char *)msg->data + msg->copied;
 474         size_t mlen = min(msg->len, buflen);
 475         unsigned long left;
 476
 477         left = copy_to_user(dst, data, mlen);
 478         if (left == mlen) {
 479                 msg->errno = -EFAULT;
 480                 return -EFAULT;
 481         }
 482
 483         mlen -= left;
 484         msg->copied += mlen;
 485         msg->errno = 0;
 486         return mlen;
 487 }
 488
 489 #define MSG_BUF_MAXSIZE 1024
 490
 491 static ssize_t
 492 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 493 {
 494         const void *p, *end;
 495         void *buf;
 496         struct rpc_clnt *clnt;
 497         struct gss_upcall_msg *gss_msg;
 498         struct inode *inode = filp->f_path.dentry->d_inode;
 499         struct gss_cl_ctx *ctx;
 500         uid_t uid;
 501         ssize_t err = -EFBIG;
 502
 503         if (mlen > MSG_BUF_MAXSIZE)
 504                 goto out;
 505         err = -ENOMEM;
 506         buf = kmalloc(mlen, GFP_KERNEL);
 507         if (!buf)
 508                 goto out;
 509
 510         clnt = RPC_I(inode)->private;
 511         err = -EFAULT;
 512         if (copy_from_user(buf, src, mlen))
 513                 goto err;
 514
 515         end = (const void *)((char *)buf + mlen);
 516         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
 517         if (IS_ERR(p)) {
 518                 err = PTR_ERR(p);
 519                 goto err;
 520         }
 521
 522         err = -ENOMEM;
 523         ctx = gss_alloc_context();
 524         if (ctx == NULL)
 525                 goto err;
 526
 527         err = -ENOENT;
 528         /* Find a matching upcall */
 529         spin_lock(&inode->i_lock);
 530         gss_msg = __gss_find_upcall(RPC_I(inode), uid);
 531         if (gss_msg == NULL) {
 532                 spin_unlock(&inode->i_lock);
 533                 goto err_put_ctx;
 534         }
 535         list_del_init(&gss_msg->list);
 536         spin_unlock(&inode->i_lock);
 537
 538         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 539         if (IS_ERR(p)) {
 540                 err = PTR_ERR(p);
 541                 gss_msg->msg.errno = (err == -EAGAIN) ? -EAGAIN : -EACCES;
 542                 goto err_release_msg;
 543         }
 544         gss_msg->ctx = gss_get_ctx(ctx);
 545         err = mlen;
 546
 547 err_release_msg:
 548         spin_lock(&inode->i_lock);
 549         __gss_unhash_msg(gss_msg);
 550         spin_unlock(&inode->i_lock);
 551         gss_release_msg(gss_msg);
 552 err_put_ctx:
 553         gss_put_ctx(ctx);
 554 err:
 555         kfree(buf);
 556 out:
 557         dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
 558         return err;
 559 }
 560
 561 static void
 562 gss_pipe_release(struct inode *inode)
 563 {
 564         struct rpc_inode *rpci = RPC_I(inode);
 565         struct gss_upcall_msg *gss_msg;
 566
 567         spin_lock(&inode->i_lock);
 568         while (!list_empty(&rpci->in_downcall)) {
 569
 570                 gss_msg = list_entry(rpci->in_downcall.next,
 571                                 struct gss_upcall_msg, list);
 572                 gss_msg->msg.errno = -EPIPE;
 573                 atomic_inc(&gss_msg->count);
 574                 __gss_unhash_msg(gss_msg);
 575                 spin_unlock(&inode->i_lock);
 576                 gss_release_msg(gss_msg);
 577                 spin_lock(&inode->i_lock);
 578         }
 579         spin_unlock(&inode->i_lock);
 580 }
 581
 582 static void
 583 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 584 {
 585         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 586         static unsigned long ratelimit;
 587
 588         if (msg->errno < 0) {
 589                 dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
 590                                 gss_msg);
 591                 atomic_inc(&gss_msg->count);
 592                 gss_unhash_msg(gss_msg);
 593                 if (msg->errno == -ETIMEDOUT) {
 594                         unsigned long now = jiffies;
 595                         if (time_after(now, ratelimit)) {
 596                                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 597                                                     "Please check user daemon is running!\n");
 598                                 ratelimit = now + 15*HZ;
 599                         }
 600                 }
 601                 gss_release_msg(gss_msg);
 602         }
 603 }
 604
 605 /*
 606  * NOTE: we have the opportunity to use different
 607  * parameters based on the input flavor (which must be a pseudoflavor)
 608  */
 609 static struct rpc_auth *
 610 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 611 {
 612         struct gss_auth *gss_auth;
 613         struct rpc_auth * auth;
 614         int err = -ENOMEM; /* XXX? */
 615
 616         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 617
 618         if (!try_module_get(THIS_MODULE))
 619                 return ERR_PTR(err);
 620         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 621                 goto out_dec;
 622         gss_auth->client = clnt;
 623         err = -EINVAL;
 624         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 625         if (!gss_auth->mech) {
 626                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
 627                                 __func__, flavor);
 628                 goto err_free;
 629         }
 630         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 631         if (gss_auth->service == 0)
 632                 goto err_put_mech;
 633         auth = &gss_auth->rpc_auth;
 634         auth->au_cslack = GSS_CRED_SLACK >> 2;
 635         auth->au_rslack = GSS_VERF_SLACK >> 2;
 636         auth->au_ops = &authgss_ops;
 637         auth->au_flavor = flavor;
 638         atomic_set(&auth->au_count, 1);
 639         kref_init(&gss_auth->kref);
 640
 641         gss_auth->dentry = rpc_mkpipe(clnt->cl_dentry, gss_auth->mech->gm_name,
 642                         clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 643         if (IS_ERR(gss_auth->dentry)) {
 644                 err = PTR_ERR(gss_auth->dentry);
 645                 goto err_put_mech;
 646         }
 647
 648         err = rpcauth_init_credcache(auth);
 649         if (err)
 650                 goto err_unlink_pipe;
 651
 652         return auth;
 653 err_unlink_pipe:
 654         rpc_unlink(gss_auth->dentry);
 655 err_put_mech:
 656         gss_mech_put(gss_auth->mech);
 657 err_free:
 658         kfree(gss_auth);
 659 out_dec:
 660         module_put(THIS_MODULE);
 661         return ERR_PTR(err);
 662 }
 663
 664 static void
 665 gss_free(struct gss_auth *gss_auth)
 666 {
 667         rpc_unlink(gss_auth->dentry);
 668         gss_auth->dentry = NULL;
 669         gss_mech_put(gss_auth->mech);
 670
 671         kfree(gss_auth);
 672         module_put(THIS_MODULE);
 673 }
 674
 675 static void
 676 gss_free_callback(struct kref *kref)
 677 {
 678         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
 679
 680         gss_free(gss_auth);
 681 }
 682
 683 static void
 684 gss_destroy(struct rpc_auth *auth)
 685 {
 686         struct gss_auth *gss_auth;
 687
 688         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
 689                         auth, auth->au_flavor);
 690
 691         rpcauth_destroy_credcache(auth);
 692
 693         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 694         kref_put(&gss_auth->kref, gss_free_callback);
 695 }
 696
 697 /*
 698  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
 699  * to the server with the GSS control procedure field set to
 700  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
 701  * all RPCSEC_GSS state associated with that context.
 702  */
 703 static int
 704 gss_destroying_context(struct rpc_cred *cred)
 705 {
 706         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 707         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 708         struct rpc_task *task;
 709
 710         if (gss_cred->gc_ctx == NULL ||
 711             test_and_clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 712                 return 0;
 713
 714         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
 715         cred->cr_ops = &gss_nullops;
 716
 717         /* Take a reference to ensure the cred will be destroyed either
 718          * by the RPC call or by the put_rpccred() below */
 719         get_rpccred(cred);
 720
 721         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
 722         if (!IS_ERR(task))
 723                 rpc_put_task(task);
 724
 725         put_rpccred(cred);
 726         return 1;
 727 }
 728
 729 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
 730  * to create a new cred or context, so they check that things have been
 731  * allocated before freeing them. */
 732 static void
 733 gss_do_free_ctx(struct gss_cl_ctx *ctx)
 734 {
 735         dprintk("RPC:       gss_free_ctx\n");
 736
 737         kfree(ctx->gc_wire_ctx.data);
 738         kfree(ctx);
 739 }
 740
 741 static void
 742 gss_free_ctx_callback(struct rcu_head *head)
 743 {
 744         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
 745         gss_do_free_ctx(ctx);
 746 }
 747
 748 static void
 749 gss_free_ctx(struct gss_cl_ctx *ctx)
 750 {
 751         struct gss_ctx *gc_gss_ctx;
 752
 753         gc_gss_ctx = rcu_dereference(ctx->gc_gss_ctx);
 754         rcu_assign_pointer(ctx->gc_gss_ctx, NULL);
 755         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
 756         if (gc_gss_ctx)
 757                 gss_delete_sec_context(&gc_gss_ctx);
 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         cred->gc_machine_cred = acred->machine_cred;
 820         kref_get(&gss_auth->kref);
 821         return &cred->gc_base;
 822
 823 out_err:
 824         dprintk("RPC:       gss_create_cred failed with error %d\n", err);
 825         return ERR_PTR(err);
 826 }
 827
 828 static int
 829 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
 830 {
 831         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 832         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
 833         int err;
 834
 835         do {
 836                 err = gss_create_upcall(gss_auth, gss_cred);
 837         } while (err == -EAGAIN);
 838         return err;
 839 }
 840
 841 static int
 842 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
 843 {
 844         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
 845
 846         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
 847                 goto out;
 848         /* Don't match with creds that have expired. */
 849         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
 850                 return 0;
 851         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
 852                 return 0;
 853 out:
 854         if (acred->machine_cred != gss_cred->gc_machine_cred)
 855                 return 0;
 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 static int gss_renew_cred(struct rpc_task *task)
 920 {
 921         struct rpc_cred *oldcred = task->tk_msg.rpc_cred;
 922         struct gss_cred *gss_cred = container_of(oldcred,
 923                                                  struct gss_cred,
 924                                                  gc_base);
 925         struct rpc_auth *auth = oldcred->cr_auth;
 926         struct auth_cred acred = {
 927                 .uid = oldcred->cr_uid,
 928                 .machine_cred = gss_cred->gc_machine_cred,
 929         };
 930         struct rpc_cred *new;
 931
 932         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
 933         if (IS_ERR(new))
 934                 return PTR_ERR(new);
 935         task->tk_msg.rpc_cred = new;
 936         put_rpccred(oldcred);
 937         return 0;
 938 }
 939
 940 /*
 941 * Refresh credentials. XXX - finish
 942 */
 943 static int
 944 gss_refresh(struct rpc_task *task)
 945 {
 946         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 947         int ret = 0;
 948
 949         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
 950                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
 951                 ret = gss_renew_cred(task);
 952                 if (ret < 0)
 953                         goto out;
 954                 cred = task->tk_msg.rpc_cred;
 955         }
 956
 957         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 958                 ret = gss_refresh_upcall(task);
 959 out:
 960         return ret;
 961 }
 962
 963 /* Dummy refresh routine: used only when destroying the context */
 964 static int
 965 gss_refresh_null(struct rpc_task *task)
 966 {
 967         return -EACCES;
 968 }
 969
 970 static __be32 *
 971 gss_validate(struct rpc_task *task, __be32 *p)
 972 {
 973         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 974         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
 975         __be32          seq;
 976         struct kvec     iov;
 977         struct xdr_buf  verf_buf;
 978         struct xdr_netobj mic;
 979         u32             flav,len;
 980         u32             maj_stat;
 981
 982         dprintk("RPC: %5u gss_validate\n", task->tk_pid);
 983
 984         flav = ntohl(*p++);
 985         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
 986                 goto out_bad;
 987         if (flav != RPC_AUTH_GSS)
 988                 goto out_bad;
 989         seq = htonl(task->tk_rqstp->rq_seqno);
 990         iov.iov_base = &seq;
 991         iov.iov_len = sizeof(seq);
 992         xdr_buf_from_iov(&iov, &verf_buf);
 993         mic.data = (u8 *)p;
 994         mic.len = len;
 995
 996         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 997         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
 998                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 999         if (maj_stat) {
1000                 dprintk("RPC: %5u gss_validate: gss_verify_mic returned "
1001                                 "error 0x%08x\n", task->tk_pid, maj_stat);
1002                 goto out_bad;
1003         }
1004         /* We leave it to unwrap to calculate au_rslack. For now we just
1005          * calculate the length of the verifier: */
1006         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1007         gss_put_ctx(ctx);
1008         dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
1009                         task->tk_pid);
1010         return p + XDR_QUADLEN(len);
1011 out_bad:
1012         gss_put_ctx(ctx);
1013         dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
1014         return NULL;
1015 }
1016
1017 static inline int
1018 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1019                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1020 {
1021         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1022         struct xdr_buf  integ_buf;
1023         __be32          *integ_len = NULL;
1024         struct xdr_netobj mic;
1025         u32             offset;
1026         __be32          *q;
1027         struct kvec     *iov;
1028         u32             maj_stat = 0;
1029         int             status = -EIO;
1030
1031         integ_len = p++;
1032         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1033         *p++ = htonl(rqstp->rq_seqno);
1034
1035         status = rpc_call_xdrproc(encode, rqstp, p, obj);
1036         if (status)
1037                 return status;
1038
1039         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1040                                 offset, snd_buf->len - offset))
1041                 return status;
1042         *integ_len = htonl(integ_buf.len);
1043
1044         /* guess whether we're in the head or the tail: */
1045         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1046                 iov = snd_buf->tail;
1047         else
1048                 iov = snd_buf->head;
1049         p = iov->iov_base + iov->iov_len;
1050         mic.data = (u8 *)(p + 1);
1051
1052         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1053         status = -EIO; /* XXX? */
1054         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1055                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1056         else if (maj_stat)
1057                 return status;
1058         q = xdr_encode_opaque(p, NULL, mic.len);
1059
1060         offset = (u8 *)q - (u8 *)p;
1061         iov->iov_len += offset;
1062         snd_buf->len += offset;
1063         return 0;
1064 }
1065
1066 static void
1067 priv_release_snd_buf(struct rpc_rqst *rqstp)
1068 {
1069         int i;
1070
1071         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1072                 __free_page(rqstp->rq_enc_pages[i]);
1073         kfree(rqstp->rq_enc_pages);
1074 }
1075
1076 static int
1077 alloc_enc_pages(struct rpc_rqst *rqstp)
1078 {
1079         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1080         int first, last, i;
1081
1082         if (snd_buf->page_len == 0) {
1083                 rqstp->rq_enc_pages_num = 0;
1084                 return 0;
1085         }
1086
1087         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1088         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1089         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1090         rqstp->rq_enc_pages
1091                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1092                                 GFP_NOFS);
1093         if (!rqstp->rq_enc_pages)
1094                 goto out;
1095         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1096                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1097                 if (rqstp->rq_enc_pages[i] == NULL)
1098                         goto out_free;
1099         }
1100         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1101         return 0;
1102 out_free:
1103         for (i--; i >= 0; i--) {
1104                 __free_page(rqstp->rq_enc_pages[i]);
1105         }
1106 out:
1107         return -EAGAIN;
1108 }
1109
1110 static inline int
1111 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1112                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1113 {
1114         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1115         u32             offset;
1116         u32             maj_stat;
1117         int             status;
1118         __be32          *opaque_len;
1119         struct page     **inpages;
1120         int             first;
1121         int             pad;
1122         struct kvec     *iov;
1123         char            *tmp;
1124
1125         opaque_len = p++;
1126         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1127         *p++ = htonl(rqstp->rq_seqno);
1128
1129         status = rpc_call_xdrproc(encode, rqstp, p, obj);
1130         if (status)
1131                 return status;
1132
1133         status = alloc_enc_pages(rqstp);
1134         if (status)
1135                 return status;
1136         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1137         inpages = snd_buf->pages + first;
1138         snd_buf->pages = rqstp->rq_enc_pages;
1139         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1140         /* Give the tail its own page, in case we need extra space in the
1141          * head when wrapping: */
1142         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1143                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1144                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1145                 snd_buf->tail[0].iov_base = tmp;
1146         }
1147         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1148         /* RPC_SLACK_SPACE should prevent this ever happening: */
1149         BUG_ON(snd_buf->len > snd_buf->buflen);
1150         status = -EIO;
1151         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1152          * done anyway, so it's safe to put the request on the wire: */
1153         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1154                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1155         else if (maj_stat)
1156                 return status;
1157
1158         *opaque_len = htonl(snd_buf->len - offset);
1159         /* guess whether we're in the head or the tail: */
1160         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1161                 iov = snd_buf->tail;
1162         else
1163                 iov = snd_buf->head;
1164         p = iov->iov_base + iov->iov_len;
1165         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1166         memset(p, 0, pad);
1167         iov->iov_len += pad;
1168         snd_buf->len += pad;
1169
1170         return 0;
1171 }
1172
1173 static int
1174 gss_wrap_req(struct rpc_task *task,
1175              kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
1176 {
1177         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1178         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1179                         gc_base);
1180         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1181         int             status = -EIO;
1182
1183         dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
1184         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1185                 /* The spec seems a little ambiguous here, but I think that not
1186                  * wrapping context destruction requests makes the most sense.
1187                  */
1188                 status = rpc_call_xdrproc(encode, rqstp, p, obj);
1189                 goto out;
1190         }
1191         switch (gss_cred->gc_service) {
1192                 case RPC_GSS_SVC_NONE:
1193                         status = rpc_call_xdrproc(encode, rqstp, p, obj);
1194                         break;
1195                 case RPC_GSS_SVC_INTEGRITY:
1196                         status = gss_wrap_req_integ(cred, ctx, encode,
1197                                                                 rqstp, p, obj);
1198                         break;
1199                 case RPC_GSS_SVC_PRIVACY:
1200                         status = gss_wrap_req_priv(cred, ctx, encode,
1201                                         rqstp, p, obj);
1202                         break;
1203         }
1204 out:
1205         gss_put_ctx(ctx);
1206         dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
1207         return status;
1208 }
1209
1210 static inline int
1211 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1212                 struct rpc_rqst *rqstp, __be32 **p)
1213 {
1214         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1215         struct xdr_buf integ_buf;
1216         struct xdr_netobj mic;
1217         u32 data_offset, mic_offset;
1218         u32 integ_len;
1219         u32 maj_stat;
1220         int status = -EIO;
1221
1222         integ_len = ntohl(*(*p)++);
1223         if (integ_len & 3)
1224                 return status;
1225         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1226         mic_offset = integ_len + data_offset;
1227         if (mic_offset > rcv_buf->len)
1228                 return status;
1229         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1230                 return status;
1231
1232         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1233                                 mic_offset - data_offset))
1234                 return status;
1235
1236         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1237                 return status;
1238
1239         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1240         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1241                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1242         if (maj_stat != GSS_S_COMPLETE)
1243                 return status;
1244         return 0;
1245 }
1246
1247 static inline int
1248 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1249                 struct rpc_rqst *rqstp, __be32 **p)
1250 {
1251         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1252         u32 offset;
1253         u32 opaque_len;
1254         u32 maj_stat;
1255         int status = -EIO;
1256
1257         opaque_len = ntohl(*(*p)++);
1258         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1259         if (offset + opaque_len > rcv_buf->len)
1260                 return status;
1261         /* remove padding: */
1262         rcv_buf->len = offset + opaque_len;
1263
1264         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1265         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1266                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1267         if (maj_stat != GSS_S_COMPLETE)
1268                 return status;
1269         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1270                 return status;
1271
1272         return 0;
1273 }
1274
1275
1276 static int
1277 gss_unwrap_resp(struct rpc_task *task,
1278                 kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
1279 {
1280         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1281         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1282                         gc_base);
1283         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1284         __be32          *savedp = p;
1285         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1286         int             savedlen = head->iov_len;
1287         int             status = -EIO;
1288
1289         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1290                 goto out_decode;
1291         switch (gss_cred->gc_service) {
1292                 case RPC_GSS_SVC_NONE:
1293                         break;
1294                 case RPC_GSS_SVC_INTEGRITY:
1295                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1296                         if (status)
1297                                 goto out;
1298                         break;
1299                 case RPC_GSS_SVC_PRIVACY:
1300                         status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1301                         if (status)
1302                                 goto out;
1303                         break;
1304         }
1305         /* take into account extra slack for integrity and privacy cases: */
1306         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1307                                                 + (savedlen - head->iov_len);
1308 out_decode:
1309         status = rpc_call_xdrproc(decode, rqstp, p, obj);
1310 out:
1311         gss_put_ctx(ctx);
1312         dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
1313                         status);
1314         return status;
1315 }
1316
1317 static const struct rpc_authops authgss_ops = {
1318         .owner          = THIS_MODULE,
1319         .au_flavor      = RPC_AUTH_GSS,
1320         .au_name        = "RPCSEC_GSS",
1321         .create         = gss_create,
1322         .destroy        = gss_destroy,
1323         .lookup_cred    = gss_lookup_cred,
1324         .crcreate       = gss_create_cred
1325 };
1326
1327 static const struct rpc_credops gss_credops = {
1328         .cr_name        = "AUTH_GSS",
1329         .crdestroy      = gss_destroy_cred,
1330         .cr_init        = gss_cred_init,
1331         .crbind         = rpcauth_generic_bind_cred,
1332         .crmatch        = gss_match,
1333         .crmarshal      = gss_marshal,
1334         .crrefresh      = gss_refresh,
1335         .crvalidate     = gss_validate,
1336         .crwrap_req     = gss_wrap_req,
1337         .crunwrap_resp  = gss_unwrap_resp,
1338 };
1339
1340 static const struct rpc_credops gss_nullops = {
1341         .cr_name        = "AUTH_GSS",
1342         .crdestroy      = gss_destroy_cred,
1343         .crbind         = rpcauth_generic_bind_cred,
1344         .crmatch        = gss_match,
1345         .crmarshal      = gss_marshal,
1346         .crrefresh      = gss_refresh_null,
1347         .crvalidate     = gss_validate,
1348         .crwrap_req     = gss_wrap_req,
1349         .crunwrap_resp  = gss_unwrap_resp,
1350 };
1351
1352 static struct rpc_pipe_ops gss_upcall_ops = {
1353         .upcall         = gss_pipe_upcall,
1354         .downcall       = gss_pipe_downcall,
1355         .destroy_msg    = gss_pipe_destroy_msg,
1356         .release_pipe   = gss_pipe_release,
1357 };
1358
1359 /*
1360  * Initialize RPCSEC_GSS module
1361  */
1362 static int __init init_rpcsec_gss(void)
1363 {
1364         int err = 0;
1365
1366         err = rpcauth_register(&authgss_ops);
1367         if (err)
1368                 goto out;
1369         err = gss_svc_init();
1370         if (err)
1371                 goto out_unregister;
1372         return 0;
1373 out_unregister:
1374         rpcauth_unregister(&authgss_ops);
1375 out:
1376         return err;
1377 }
1378
1379 static void __exit exit_rpcsec_gss(void)
1380 {
1381         gss_svc_shutdown();
1382         rpcauth_unregister(&authgss_ops);
1383 }
1384
1385 MODULE_LICENSE("GPL");
1386 module_init(init_rpcsec_gss)
1387 module_exit(exit_rpcsec_gss)