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   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 GSS_CRED_SLACK          1024
  67 /* length of a krb5 verifier (48), plus data added before arguments when
  68  * using integrity (two 4-byte integers): */
  69 #define GSS_VERF_SLACK          100
  70
  71 struct gss_auth {
  72         struct kref kref;
  73         struct rpc_auth rpc_auth;
  74         struct gss_api_mech *mech;
  75         enum rpc_gss_svc service;
  76         struct rpc_clnt *client;
  77         struct dentry *dentry;
  78 };
  79
  80 static void gss_free_ctx(struct gss_cl_ctx *);
  81 static struct rpc_pipe_ops gss_upcall_ops;
  82
  83 static inline struct gss_cl_ctx *
  84 gss_get_ctx(struct gss_cl_ctx *ctx)
  85 {
  86         atomic_inc(&ctx->count);
  87         return ctx;
  88 }
  89
  90 static inline void
  91 gss_put_ctx(struct gss_cl_ctx *ctx)
  92 {
  93         if (atomic_dec_and_test(&ctx->count))
  94                 gss_free_ctx(ctx);
  95 }
  96
  97 /* gss_cred_set_ctx:
  98  * called by gss_upcall_callback and gss_create_upcall in order
  99  * to set the gss context. The actual exchange of an old context
 100  * and a new one is protected by the inode->i_lock.
 101  */
 102 static void
 103 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 104 {
 105         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 106
 107         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 108                 return;
 109         gss_get_ctx(ctx);
 110         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 111         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 112         smp_mb__before_clear_bit();
 113         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 114 }
 115
 116 static const void *
 117 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 118 {
 119         const void *q = (const void *)((const char *)p + len);
 120         if (unlikely(q > end || q < p))
 121                 return ERR_PTR(-EFAULT);
 122         memcpy(res, p, len);
 123         return q;
 124 }
 125
 126 static inline const void *
 127 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 128 {
 129         const void *q;
 130         unsigned int len;
 131
 132         p = simple_get_bytes(p, end, &len, sizeof(len));
 133         if (IS_ERR(p))
 134                 return p;
 135         q = (const void *)((const char *)p + len);
 136         if (unlikely(q > end || q < p))
 137                 return ERR_PTR(-EFAULT);
 138         dest->data = kmemdup(p, len, GFP_NOFS);
 139         if (unlikely(dest->data == NULL))
 140                 return ERR_PTR(-ENOMEM);
 141         dest->len = len;
 142         return q;
 143 }
 144
 145 static struct gss_cl_ctx *
 146 gss_cred_get_ctx(struct rpc_cred *cred)
 147 {
 148         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 149         struct gss_cl_ctx *ctx = NULL;
 150
 151         rcu_read_lock();
 152         if (gss_cred->gc_ctx)
 153                 ctx = gss_get_ctx(gss_cred->gc_ctx);
 154         rcu_read_unlock();
 155         return ctx;
 156 }
 157
 158 static struct gss_cl_ctx *
 159 gss_alloc_context(void)
 160 {
 161         struct gss_cl_ctx *ctx;
 162
 163         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
 164         if (ctx != NULL) {
 165                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 166                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 167                 spin_lock_init(&ctx->gc_seq_lock);
 168                 atomic_set(&ctx->count,1);
 169         }
 170         return ctx;
 171 }
 172
 173 #define GSSD_MIN_TIMEOUT (60 * 60)
 174 static const void *
 175 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 176 {
 177         const void *q;
 178         unsigned int seclen;
 179         unsigned int timeout;
 180         u32 window_size;
 181         int ret;
 182
 183         /* First unsigned int gives the lifetime (in seconds) of the cred */
 184         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 185         if (IS_ERR(p))
 186                 goto err;
 187         if (timeout == 0)
 188                 timeout = GSSD_MIN_TIMEOUT;
 189         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
 190         /* Sequence number window. Determines the maximum number of simultaneous requests */
 191         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 192         if (IS_ERR(p))
 193                 goto err;
 194         ctx->gc_win = window_size;
 195         /* gssd signals an error by passing ctx->gc_win = 0: */
 196         if (ctx->gc_win == 0) {
 197                 /* in which case, p points to  an error code which we ignore */
 198                 p = ERR_PTR(-EACCES);
 199                 goto err;
 200         }
 201         /* copy the opaque wire context */
 202         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 203         if (IS_ERR(p))
 204                 goto err;
 205         /* import the opaque security context */
 206         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 207         if (IS_ERR(p))
 208                 goto err;
 209         q = (const void *)((const char *)p + seclen);
 210         if (unlikely(q > end || q < p)) {
 211                 p = ERR_PTR(-EFAULT);
 212                 goto err;
 213         }
 214         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
 215         if (ret < 0) {
 216                 p = ERR_PTR(ret);
 217                 goto err;
 218         }
 219         return q;
 220 err:
 221         dprintk("RPC:       gss_fill_context returning %ld\n", -PTR_ERR(p));
 222         return p;
 223 }
 224
 225
 226 struct gss_upcall_msg {
 227         atomic_t count;
 228         uid_t   uid;
 229         struct rpc_pipe_msg msg;
 230         struct list_head list;
 231         struct gss_auth *auth;
 232         struct rpc_wait_queue rpc_waitqueue;
 233         wait_queue_head_t waitqueue;
 234         struct gss_cl_ctx *ctx;
 235 };
 236
 237 static void
 238 gss_release_msg(struct gss_upcall_msg *gss_msg)
 239 {
 240         if (!atomic_dec_and_test(&gss_msg->count))
 241                 return;
 242         BUG_ON(!list_empty(&gss_msg->list));
 243         if (gss_msg->ctx != NULL)
 244                 gss_put_ctx(gss_msg->ctx);
 245         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 246         kfree(gss_msg);
 247 }
 248
 249 static struct gss_upcall_msg *
 250 __gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
 251 {
 252         struct gss_upcall_msg *pos;
 253         list_for_each_entry(pos, &rpci->in_downcall, list) {
 254                 if (pos->uid != uid)
 255                         continue;
 256                 atomic_inc(&pos->count);
 257                 dprintk("RPC:       gss_find_upcall found msg %p\n", pos);
 258                 return pos;
 259         }
 260         dprintk("RPC:       gss_find_upcall found nothing\n");
 261         return NULL;
 262 }
 263
 264 /* Try to add an upcall to the pipefs queue.
 265  * If an upcall owned by our uid already exists, then we return a reference
 266  * to that upcall instead of adding the new upcall.
 267  */
 268 static inline struct gss_upcall_msg *
 269 gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
 270 {
 271         struct inode *inode = gss_auth->dentry->d_inode;
 272         struct rpc_inode *rpci = RPC_I(inode);
 273         struct gss_upcall_msg *old;
 274
 275         spin_lock(&inode->i_lock);
 276         old = __gss_find_upcall(rpci, gss_msg->uid);
 277         if (old == NULL) {
 278                 atomic_inc(&gss_msg->count);
 279                 list_add(&gss_msg->list, &rpci->in_downcall);
 280         } else
 281                 gss_msg = old;
 282         spin_unlock(&inode->i_lock);
 283         return gss_msg;
 284 }
 285
 286 static void
 287 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 288 {
 289         list_del_init(&gss_msg->list);
 290         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 291         wake_up_all(&gss_msg->waitqueue);
 292         atomic_dec(&gss_msg->count);
 293 }
 294
 295 static void
 296 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 297 {
 298         struct gss_auth *gss_auth = gss_msg->auth;
 299         struct inode *inode = gss_auth->dentry->d_inode;
 300
 301         if (list_empty(&gss_msg->list))
 302                 return;
 303         spin_lock(&inode->i_lock);
 304         if (!list_empty(&gss_msg->list))
 305                 __gss_unhash_msg(gss_msg);
 306         spin_unlock(&inode->i_lock);
 307 }
 308
 309 static void
 310 gss_upcall_callback(struct rpc_task *task)
 311 {
 312         struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
 313                         struct gss_cred, gc_base);
 314         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 315         struct inode *inode = gss_msg->auth->dentry->d_inode;
 316
 317         spin_lock(&inode->i_lock);
 318         if (gss_msg->ctx)
 319                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
 320         else
 321                 task->tk_status = gss_msg->msg.errno;
 322         gss_cred->gc_upcall = NULL;
 323         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 324         spin_unlock(&inode->i_lock);
 325         gss_release_msg(gss_msg);
 326 }
 327
 328 static inline struct gss_upcall_msg *
 329 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid)
 330 {
 331         struct gss_upcall_msg *gss_msg;
 332
 333         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 334         if (gss_msg != NULL) {
 335                 INIT_LIST_HEAD(&gss_msg->list);
 336                 rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 337                 init_waitqueue_head(&gss_msg->waitqueue);
 338                 atomic_set(&gss_msg->count, 1);
 339                 gss_msg->msg.data = &gss_msg->uid;
 340                 gss_msg->msg.len = sizeof(gss_msg->uid);
 341                 gss_msg->uid = uid;
 342                 gss_msg->auth = gss_auth;
 343         }
 344         return gss_msg;
 345 }
 346
 347 static struct gss_upcall_msg *
 348 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
 349 {
 350         struct gss_cred *gss_cred = container_of(cred,
 351                         struct gss_cred, gc_base);
 352         struct gss_upcall_msg *gss_new, *gss_msg;
 353         uid_t uid = cred->cr_uid;
 354
 355         /* Special case: rpc.gssd assumes that uid == 0 implies machine creds */
 356         if (gss_cred->gc_machine_cred != 0)
 357                 uid = 0;
 358
 359         gss_new = gss_alloc_msg(gss_auth, uid);
 360         if (gss_new == NULL)
 361                 return ERR_PTR(-ENOMEM);
 362         gss_msg = gss_add_msg(gss_auth, gss_new);
 363         if (gss_msg == gss_new) {
 364                 int res = rpc_queue_upcall(gss_auth->dentry->d_inode, &gss_new->msg);
 365                 if (res) {
 366                         gss_unhash_msg(gss_new);
 367                         gss_msg = ERR_PTR(res);
 368                 }
 369         } else
 370                 gss_release_msg(gss_new);
 371         return gss_msg;
 372 }
 373
 374 static inline int
 375 gss_refresh_upcall(struct rpc_task *task)
 376 {
 377         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 378         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 379                         struct gss_auth, rpc_auth);
 380         struct gss_cred *gss_cred = container_of(cred,
 381                         struct gss_cred, gc_base);
 382         struct gss_upcall_msg *gss_msg;
 383         struct inode *inode = gss_auth->dentry->d_inode;
 384         int err = 0;
 385
 386         dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
 387                                                                 cred->cr_uid);
 388         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
 389         if (IS_ERR(gss_msg)) {
 390                 err = PTR_ERR(gss_msg);
 391                 goto out;
 392         }
 393         spin_lock(&inode->i_lock);
 394         if (gss_cred->gc_upcall != NULL)
 395                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 396         else if (gss_msg->ctx != NULL) {
 397                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
 398                 gss_cred->gc_upcall = NULL;
 399                 rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 400         } else if (gss_msg->msg.errno >= 0) {
 401                 task->tk_timeout = 0;
 402                 gss_cred->gc_upcall = gss_msg;
 403                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 404                 atomic_inc(&gss_msg->count);
 405                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 406         } else
 407                 err = gss_msg->msg.errno;
 408         spin_unlock(&inode->i_lock);
 409         gss_release_msg(gss_msg);
 410 out:
 411         dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
 412                         task->tk_pid, cred->cr_uid, err);
 413         return err;
 414 }
 415
 416 static inline int
 417 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 418 {
 419         struct inode *inode = gss_auth->dentry->d_inode;
 420         struct rpc_cred *cred = &gss_cred->gc_base;
 421         struct gss_upcall_msg *gss_msg;
 422         DEFINE_WAIT(wait);
 423         int err = 0;
 424
 425         dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
 426         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 427         if (IS_ERR(gss_msg)) {
 428                 err = PTR_ERR(gss_msg);
 429                 goto out;
 430         }
 431         for (;;) {
 432                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
 433                 spin_lock(&inode->i_lock);
 434                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 435                         break;
 436                 }
 437                 spin_unlock(&inode->i_lock);
 438                 if (signalled()) {
 439                         err = -ERESTARTSYS;
 440                         goto out_intr;
 441                 }
 442                 schedule();
 443         }
 444         if (gss_msg->ctx)
 445                 gss_cred_set_ctx(cred, gss_msg->ctx);
 446         else
 447                 err = gss_msg->msg.errno;
 448         spin_unlock(&inode->i_lock);
 449 out_intr:
 450         finish_wait(&gss_msg->waitqueue, &wait);
 451         gss_release_msg(gss_msg);
 452 out:
 453         dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
 454                         cred->cr_uid, err);
 455         return err;
 456 }
 457
 458 static ssize_t
 459 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 460                 char __user *dst, size_t buflen)
 461 {
 462         char *data = (char *)msg->data + msg->copied;
 463         size_t mlen = min(msg->len, buflen);
 464         unsigned long left;
 465
 466         left = copy_to_user(dst, data, mlen);
 467         if (left == mlen) {
 468                 msg->errno = -EFAULT;
 469                 return -EFAULT;
 470         }
 471
 472         mlen -= left;
 473         msg->copied += mlen;
 474         msg->errno = 0;
 475         return mlen;
 476 }
 477
 478 #define MSG_BUF_MAXSIZE 1024
 479
 480 static ssize_t
 481 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 482 {
 483         const void *p, *end;
 484         void *buf;
 485         struct gss_upcall_msg *gss_msg;
 486         struct inode *inode = filp->f_path.dentry->d_inode;
 487         struct gss_cl_ctx *ctx;
 488         uid_t uid;
 489         ssize_t err = -EFBIG;
 490
 491         if (mlen > MSG_BUF_MAXSIZE)
 492                 goto out;
 493         err = -ENOMEM;
 494         buf = kmalloc(mlen, GFP_NOFS);
 495         if (!buf)
 496                 goto out;
 497
 498         err = -EFAULT;
 499         if (copy_from_user(buf, src, mlen))
 500                 goto err;
 501
 502         end = (const void *)((char *)buf + mlen);
 503         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
 504         if (IS_ERR(p)) {
 505                 err = PTR_ERR(p);
 506                 goto err;
 507         }
 508
 509         err = -ENOMEM;
 510         ctx = gss_alloc_context();
 511         if (ctx == NULL)
 512                 goto err;
 513
 514         err = -ENOENT;
 515         /* Find a matching upcall */
 516         spin_lock(&inode->i_lock);
 517         gss_msg = __gss_find_upcall(RPC_I(inode), uid);
 518         if (gss_msg == NULL) {
 519                 spin_unlock(&inode->i_lock);
 520                 goto err_put_ctx;
 521         }
 522         list_del_init(&gss_msg->list);
 523         spin_unlock(&inode->i_lock);
 524
 525         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 526         if (IS_ERR(p)) {
 527                 err = PTR_ERR(p);
 528                 gss_msg->msg.errno = (err == -EAGAIN) ? -EAGAIN : -EACCES;
 529                 goto err_release_msg;
 530         }
 531         gss_msg->ctx = gss_get_ctx(ctx);
 532         err = mlen;
 533
 534 err_release_msg:
 535         spin_lock(&inode->i_lock);
 536         __gss_unhash_msg(gss_msg);
 537         spin_unlock(&inode->i_lock);
 538         gss_release_msg(gss_msg);
 539 err_put_ctx:
 540         gss_put_ctx(ctx);
 541 err:
 542         kfree(buf);
 543 out:
 544         dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
 545         return err;
 546 }
 547
 548 static void
 549 gss_pipe_release(struct inode *inode)
 550 {
 551         struct rpc_inode *rpci = RPC_I(inode);
 552         struct gss_upcall_msg *gss_msg;
 553
 554         spin_lock(&inode->i_lock);
 555         while (!list_empty(&rpci->in_downcall)) {
 556
 557                 gss_msg = list_entry(rpci->in_downcall.next,
 558                                 struct gss_upcall_msg, list);
 559                 gss_msg->msg.errno = -EPIPE;
 560                 atomic_inc(&gss_msg->count);
 561                 __gss_unhash_msg(gss_msg);
 562                 spin_unlock(&inode->i_lock);
 563                 gss_release_msg(gss_msg);
 564                 spin_lock(&inode->i_lock);
 565         }
 566         spin_unlock(&inode->i_lock);
 567 }
 568
 569 static void
 570 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 571 {
 572         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 573         static unsigned long ratelimit;
 574
 575         if (msg->errno < 0) {
 576                 dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
 577                                 gss_msg);
 578                 atomic_inc(&gss_msg->count);
 579                 gss_unhash_msg(gss_msg);
 580                 if (msg->errno == -ETIMEDOUT) {
 581                         unsigned long now = jiffies;
 582                         if (time_after(now, ratelimit)) {
 583                                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 584                                                     "Please check user daemon is running!\n");
 585                                 ratelimit = now + 15*HZ;
 586                         }
 587                 }
 588                 gss_release_msg(gss_msg);
 589         }
 590 }
 591
 592 /*
 593  * NOTE: we have the opportunity to use different
 594  * parameters based on the input flavor (which must be a pseudoflavor)
 595  */
 596 static struct rpc_auth *
 597 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 598 {
 599         struct gss_auth *gss_auth;
 600         struct rpc_auth * auth;
 601         int err = -ENOMEM; /* XXX? */
 602
 603         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 604
 605         if (!try_module_get(THIS_MODULE))
 606                 return ERR_PTR(err);
 607         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 608                 goto out_dec;
 609         gss_auth->client = clnt;
 610         err = -EINVAL;
 611         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 612         if (!gss_auth->mech) {
 613                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
 614                                 __func__, flavor);
 615                 goto err_free;
 616         }
 617         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 618         if (gss_auth->service == 0)
 619                 goto err_put_mech;
 620         auth = &gss_auth->rpc_auth;
 621         auth->au_cslack = GSS_CRED_SLACK >> 2;
 622         auth->au_rslack = GSS_VERF_SLACK >> 2;
 623         auth->au_ops = &authgss_ops;
 624         auth->au_flavor = flavor;
 625         atomic_set(&auth->au_count, 1);
 626         kref_init(&gss_auth->kref);
 627
 628         gss_auth->dentry = rpc_mkpipe(clnt->cl_dentry, gss_auth->mech->gm_name,
 629                         clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 630         if (IS_ERR(gss_auth->dentry)) {
 631                 err = PTR_ERR(gss_auth->dentry);
 632                 goto err_put_mech;
 633         }
 634
 635         err = rpcauth_init_credcache(auth);
 636         if (err)
 637                 goto err_unlink_pipe;
 638
 639         return auth;
 640 err_unlink_pipe:
 641         rpc_unlink(gss_auth->dentry);
 642 err_put_mech:
 643         gss_mech_put(gss_auth->mech);
 644 err_free:
 645         kfree(gss_auth);
 646 out_dec:
 647         module_put(THIS_MODULE);
 648         return ERR_PTR(err);
 649 }
 650
 651 static void
 652 gss_free(struct gss_auth *gss_auth)
 653 {
 654         rpc_unlink(gss_auth->dentry);
 655         gss_auth->dentry = NULL;
 656         gss_mech_put(gss_auth->mech);
 657
 658         kfree(gss_auth);
 659         module_put(THIS_MODULE);
 660 }
 661
 662 static void
 663 gss_free_callback(struct kref *kref)
 664 {
 665         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
 666
 667         gss_free(gss_auth);
 668 }
 669
 670 static void
 671 gss_destroy(struct rpc_auth *auth)
 672 {
 673         struct gss_auth *gss_auth;
 674
 675         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
 676                         auth, auth->au_flavor);
 677
 678         rpcauth_destroy_credcache(auth);
 679
 680         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 681         kref_put(&gss_auth->kref, gss_free_callback);
 682 }
 683
 684 /*
 685  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
 686  * to the server with the GSS control procedure field set to
 687  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
 688  * all RPCSEC_GSS state associated with that context.
 689  */
 690 static int
 691 gss_destroying_context(struct rpc_cred *cred)
 692 {
 693         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 694         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 695         struct rpc_task *task;
 696
 697         if (gss_cred->gc_ctx == NULL ||
 698             test_and_clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 699                 return 0;
 700
 701         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
 702         cred->cr_ops = &gss_nullops;
 703
 704         /* Take a reference to ensure the cred will be destroyed either
 705          * by the RPC call or by the put_rpccred() below */
 706         get_rpccred(cred);
 707
 708         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
 709         if (!IS_ERR(task))
 710                 rpc_put_task(task);
 711
 712         put_rpccred(cred);
 713         return 1;
 714 }
 715
 716 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
 717  * to create a new cred or context, so they check that things have been
 718  * allocated before freeing them. */
 719 static void
 720 gss_do_free_ctx(struct gss_cl_ctx *ctx)
 721 {
 722         dprintk("RPC:       gss_free_ctx\n");
 723
 724         kfree(ctx->gc_wire_ctx.data);
 725         kfree(ctx);
 726 }
 727
 728 static void
 729 gss_free_ctx_callback(struct rcu_head *head)
 730 {
 731         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
 732         gss_do_free_ctx(ctx);
 733 }
 734
 735 static void
 736 gss_free_ctx(struct gss_cl_ctx *ctx)
 737 {
 738         struct gss_ctx *gc_gss_ctx;
 739
 740         gc_gss_ctx = rcu_dereference(ctx->gc_gss_ctx);
 741         rcu_assign_pointer(ctx->gc_gss_ctx, NULL);
 742         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
 743         if (gc_gss_ctx)
 744                 gss_delete_sec_context(&gc_gss_ctx);
 745 }
 746
 747 static void
 748 gss_free_cred(struct gss_cred *gss_cred)
 749 {
 750         dprintk("RPC:       gss_free_cred %p\n", gss_cred);
 751         kfree(gss_cred);
 752 }
 753
 754 static void
 755 gss_free_cred_callback(struct rcu_head *head)
 756 {
 757         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
 758         gss_free_cred(gss_cred);
 759 }
 760
 761 static void
 762 gss_destroy_cred(struct rpc_cred *cred)
 763 {
 764         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 765         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 766         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
 767
 768         if (gss_destroying_context(cred))
 769                 return;
 770         rcu_assign_pointer(gss_cred->gc_ctx, NULL);
 771         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
 772         if (ctx)
 773                 gss_put_ctx(ctx);
 774         kref_put(&gss_auth->kref, gss_free_callback);
 775 }
 776
 777 /*
 778  * Lookup RPCSEC_GSS cred for the current process
 779  */
 780 static struct rpc_cred *
 781 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 782 {
 783         return rpcauth_lookup_credcache(auth, acred, flags);
 784 }
 785
 786 static struct rpc_cred *
 787 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 788 {
 789         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 790         struct gss_cred *cred = NULL;
 791         int err = -ENOMEM;
 792
 793         dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
 794                 acred->uid, auth->au_flavor);
 795
 796         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
 797                 goto out_err;
 798
 799         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
 800         /*
 801          * Note: in order to force a call to call_refresh(), we deliberately
 802          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
 803          */
 804         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
 805         cred->gc_service = gss_auth->service;
 806         cred->gc_machine_cred = acred->machine_cred;
 807         kref_get(&gss_auth->kref);
 808         return &cred->gc_base;
 809
 810 out_err:
 811         dprintk("RPC:       gss_create_cred failed with error %d\n", err);
 812         return ERR_PTR(err);
 813 }
 814
 815 static int
 816 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
 817 {
 818         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 819         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
 820         int err;
 821
 822         do {
 823                 err = gss_create_upcall(gss_auth, gss_cred);
 824         } while (err == -EAGAIN);
 825         return err;
 826 }
 827
 828 static int
 829 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
 830 {
 831         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
 832
 833         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
 834                 goto out;
 835         /* Don't match with creds that have expired. */
 836         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
 837                 return 0;
 838         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
 839                 return 0;
 840 out:
 841         if (acred->machine_cred != gss_cred->gc_machine_cred)
 842                 return 0;
 843         return (rc->cr_uid == acred->uid);
 844 }
 845
 846 /*
 847 * Marshal credentials.
 848 * Maybe we should keep a cached credential for performance reasons.
 849 */
 850 static __be32 *
 851 gss_marshal(struct rpc_task *task, __be32 *p)
 852 {
 853         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 854         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
 855                                                  gc_base);
 856         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
 857         __be32          *cred_len;
 858         struct rpc_rqst *req = task->tk_rqstp;
 859         u32             maj_stat = 0;
 860         struct xdr_netobj mic;
 861         struct kvec     iov;
 862         struct xdr_buf  verf_buf;
 863
 864         dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
 865
 866         *p++ = htonl(RPC_AUTH_GSS);
 867         cred_len = p++;
 868
 869         spin_lock(&ctx->gc_seq_lock);
 870         req->rq_seqno = ctx->gc_seq++;
 871         spin_unlock(&ctx->gc_seq_lock);
 872
 873         *p++ = htonl((u32) RPC_GSS_VERSION);
 874         *p++ = htonl((u32) ctx->gc_proc);
 875         *p++ = htonl((u32) req->rq_seqno);
 876         *p++ = htonl((u32) gss_cred->gc_service);
 877         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
 878         *cred_len = htonl((p - (cred_len + 1)) << 2);
 879
 880         /* We compute the checksum for the verifier over the xdr-encoded bytes
 881          * starting with the xid and ending at the end of the credential: */
 882         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
 883                                         req->rq_snd_buf.head[0].iov_base);
 884         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
 885         xdr_buf_from_iov(&iov, &verf_buf);
 886
 887         /* set verifier flavor*/
 888         *p++ = htonl(RPC_AUTH_GSS);
 889
 890         mic.data = (u8 *)(p + 1);
 891         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 892         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
 893                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 894         } else if (maj_stat != 0) {
 895                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
 896                 goto out_put_ctx;
 897         }
 898         p = xdr_encode_opaque(p, NULL, mic.len);
 899         gss_put_ctx(ctx);
 900         return p;
 901 out_put_ctx:
 902         gss_put_ctx(ctx);
 903         return NULL;
 904 }
 905
 906 static int gss_renew_cred(struct rpc_task *task)
 907 {
 908         struct rpc_cred *oldcred = task->tk_msg.rpc_cred;
 909         struct gss_cred *gss_cred = container_of(oldcred,
 910                                                  struct gss_cred,
 911                                                  gc_base);
 912         struct rpc_auth *auth = oldcred->cr_auth;
 913         struct auth_cred acred = {
 914                 .uid = oldcred->cr_uid,
 915                 .machine_cred = gss_cred->gc_machine_cred,
 916         };
 917         struct rpc_cred *new;
 918
 919         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
 920         if (IS_ERR(new))
 921                 return PTR_ERR(new);
 922         task->tk_msg.rpc_cred = new;
 923         put_rpccred(oldcred);
 924         return 0;
 925 }
 926
 927 /*
 928 * Refresh credentials. XXX - finish
 929 */
 930 static int
 931 gss_refresh(struct rpc_task *task)
 932 {
 933         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 934         int ret = 0;
 935
 936         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
 937                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
 938                 ret = gss_renew_cred(task);
 939                 if (ret < 0)
 940                         goto out;
 941                 cred = task->tk_msg.rpc_cred;
 942         }
 943
 944         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 945                 ret = gss_refresh_upcall(task);
 946 out:
 947         return ret;
 948 }
 949
 950 /* Dummy refresh routine: used only when destroying the context */
 951 static int
 952 gss_refresh_null(struct rpc_task *task)
 953 {
 954         return -EACCES;
 955 }
 956
 957 static __be32 *
 958 gss_validate(struct rpc_task *task, __be32 *p)
 959 {
 960         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 961         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
 962         __be32          seq;
 963         struct kvec     iov;
 964         struct xdr_buf  verf_buf;
 965         struct xdr_netobj mic;
 966         u32             flav,len;
 967         u32             maj_stat;
 968
 969         dprintk("RPC: %5u gss_validate\n", task->tk_pid);
 970
 971         flav = ntohl(*p++);
 972         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
 973                 goto out_bad;
 974         if (flav != RPC_AUTH_GSS)
 975                 goto out_bad;
 976         seq = htonl(task->tk_rqstp->rq_seqno);
 977         iov.iov_base = &seq;
 978         iov.iov_len = sizeof(seq);
 979         xdr_buf_from_iov(&iov, &verf_buf);
 980         mic.data = (u8 *)p;
 981         mic.len = len;
 982
 983         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 984         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
 985                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 986         if (maj_stat) {
 987                 dprintk("RPC: %5u gss_validate: gss_verify_mic returned "
 988                                 "error 0x%08x\n", task->tk_pid, maj_stat);
 989                 goto out_bad;
 990         }
 991         /* We leave it to unwrap to calculate au_rslack. For now we just
 992          * calculate the length of the verifier: */
 993         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
 994         gss_put_ctx(ctx);
 995         dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
 996                         task->tk_pid);
 997         return p + XDR_QUADLEN(len);
 998 out_bad:
 999         gss_put_ctx(ctx);
1000         dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
1001         return NULL;
1002 }
1003
1004 static inline int
1005 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1006                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1007 {
1008         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1009         struct xdr_buf  integ_buf;
1010         __be32          *integ_len = NULL;
1011         struct xdr_netobj mic;
1012         u32             offset;
1013         __be32          *q;
1014         struct kvec     *iov;
1015         u32             maj_stat = 0;
1016         int             status = -EIO;
1017
1018         integ_len = p++;
1019         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1020         *p++ = htonl(rqstp->rq_seqno);
1021
1022         status = rpc_call_xdrproc(encode, rqstp, p, obj);
1023         if (status)
1024                 return status;
1025
1026         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1027                                 offset, snd_buf->len - offset))
1028                 return status;
1029         *integ_len = htonl(integ_buf.len);
1030
1031         /* guess whether we're in the head or the tail: */
1032         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1033                 iov = snd_buf->tail;
1034         else
1035                 iov = snd_buf->head;
1036         p = iov->iov_base + iov->iov_len;
1037         mic.data = (u8 *)(p + 1);
1038
1039         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1040         status = -EIO; /* XXX? */
1041         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1042                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1043         else if (maj_stat)
1044                 return status;
1045         q = xdr_encode_opaque(p, NULL, mic.len);
1046
1047         offset = (u8 *)q - (u8 *)p;
1048         iov->iov_len += offset;
1049         snd_buf->len += offset;
1050         return 0;
1051 }
1052
1053 static void
1054 priv_release_snd_buf(struct rpc_rqst *rqstp)
1055 {
1056         int i;
1057
1058         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1059                 __free_page(rqstp->rq_enc_pages[i]);
1060         kfree(rqstp->rq_enc_pages);
1061 }
1062
1063 static int
1064 alloc_enc_pages(struct rpc_rqst *rqstp)
1065 {
1066         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1067         int first, last, i;
1068
1069         if (snd_buf->page_len == 0) {
1070                 rqstp->rq_enc_pages_num = 0;
1071                 return 0;
1072         }
1073
1074         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1075         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1076         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1077         rqstp->rq_enc_pages
1078                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1079                                 GFP_NOFS);
1080         if (!rqstp->rq_enc_pages)
1081                 goto out;
1082         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1083                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1084                 if (rqstp->rq_enc_pages[i] == NULL)
1085                         goto out_free;
1086         }
1087         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1088         return 0;
1089 out_free:
1090         for (i--; i >= 0; i--) {
1091                 __free_page(rqstp->rq_enc_pages[i]);
1092         }
1093 out:
1094         return -EAGAIN;
1095 }
1096
1097 static inline int
1098 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1099                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1100 {
1101         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1102         u32             offset;
1103         u32             maj_stat;
1104         int             status;
1105         __be32          *opaque_len;
1106         struct page     **inpages;
1107         int             first;
1108         int             pad;
1109         struct kvec     *iov;
1110         char            *tmp;
1111
1112         opaque_len = p++;
1113         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1114         *p++ = htonl(rqstp->rq_seqno);
1115
1116         status = rpc_call_xdrproc(encode, rqstp, p, obj);
1117         if (status)
1118                 return status;
1119
1120         status = alloc_enc_pages(rqstp);
1121         if (status)
1122                 return status;
1123         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1124         inpages = snd_buf->pages + first;
1125         snd_buf->pages = rqstp->rq_enc_pages;
1126         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1127         /* Give the tail its own page, in case we need extra space in the
1128          * head when wrapping: */
1129         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1130                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1131                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1132                 snd_buf->tail[0].iov_base = tmp;
1133         }
1134         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1135         /* RPC_SLACK_SPACE should prevent this ever happening: */
1136         BUG_ON(snd_buf->len > snd_buf->buflen);
1137         status = -EIO;
1138         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1139          * done anyway, so it's safe to put the request on the wire: */
1140         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1141                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1142         else if (maj_stat)
1143                 return status;
1144
1145         *opaque_len = htonl(snd_buf->len - offset);
1146         /* guess whether we're in the head or the tail: */
1147         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1148                 iov = snd_buf->tail;
1149         else
1150                 iov = snd_buf->head;
1151         p = iov->iov_base + iov->iov_len;
1152         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1153         memset(p, 0, pad);
1154         iov->iov_len += pad;
1155         snd_buf->len += pad;
1156
1157         return 0;
1158 }
1159
1160 static int
1161 gss_wrap_req(struct rpc_task *task,
1162              kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
1163 {
1164         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1165         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1166                         gc_base);
1167         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1168         int             status = -EIO;
1169
1170         dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
1171         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1172                 /* The spec seems a little ambiguous here, but I think that not
1173                  * wrapping context destruction requests makes the most sense.
1174                  */
1175                 status = rpc_call_xdrproc(encode, rqstp, p, obj);
1176                 goto out;
1177         }
1178         switch (gss_cred->gc_service) {
1179                 case RPC_GSS_SVC_NONE:
1180                         status = rpc_call_xdrproc(encode, rqstp, p, obj);
1181                         break;
1182                 case RPC_GSS_SVC_INTEGRITY:
1183                         status = gss_wrap_req_integ(cred, ctx, encode,
1184                                                                 rqstp, p, obj);
1185                         break;
1186                 case RPC_GSS_SVC_PRIVACY:
1187                         status = gss_wrap_req_priv(cred, ctx, encode,
1188                                         rqstp, p, obj);
1189                         break;
1190         }
1191 out:
1192         gss_put_ctx(ctx);
1193         dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
1194         return status;
1195 }
1196
1197 static inline int
1198 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1199                 struct rpc_rqst *rqstp, __be32 **p)
1200 {
1201         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1202         struct xdr_buf integ_buf;
1203         struct xdr_netobj mic;
1204         u32 data_offset, mic_offset;
1205         u32 integ_len;
1206         u32 maj_stat;
1207         int status = -EIO;
1208
1209         integ_len = ntohl(*(*p)++);
1210         if (integ_len & 3)
1211                 return status;
1212         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1213         mic_offset = integ_len + data_offset;
1214         if (mic_offset > rcv_buf->len)
1215                 return status;
1216         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1217                 return status;
1218
1219         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1220                                 mic_offset - data_offset))
1221                 return status;
1222
1223         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1224                 return status;
1225
1226         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1227         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1228                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1229         if (maj_stat != GSS_S_COMPLETE)
1230                 return status;
1231         return 0;
1232 }
1233
1234 static inline int
1235 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1236                 struct rpc_rqst *rqstp, __be32 **p)
1237 {
1238         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1239         u32 offset;
1240         u32 opaque_len;
1241         u32 maj_stat;
1242         int status = -EIO;
1243
1244         opaque_len = ntohl(*(*p)++);
1245         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1246         if (offset + opaque_len > rcv_buf->len)
1247                 return status;
1248         /* remove padding: */
1249         rcv_buf->len = offset + opaque_len;
1250
1251         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1252         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1253                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1254         if (maj_stat != GSS_S_COMPLETE)
1255                 return status;
1256         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1257                 return status;
1258
1259         return 0;
1260 }
1261
1262
1263 static int
1264 gss_unwrap_resp(struct rpc_task *task,
1265                 kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
1266 {
1267         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1268         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1269                         gc_base);
1270         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1271         __be32          *savedp = p;
1272         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1273         int             savedlen = head->iov_len;
1274         int             status = -EIO;
1275
1276         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1277                 goto out_decode;
1278         switch (gss_cred->gc_service) {
1279                 case RPC_GSS_SVC_NONE:
1280                         break;
1281                 case RPC_GSS_SVC_INTEGRITY:
1282                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1283                         if (status)
1284                                 goto out;
1285                         break;
1286                 case RPC_GSS_SVC_PRIVACY:
1287                         status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1288                         if (status)
1289                                 goto out;
1290                         break;
1291         }
1292         /* take into account extra slack for integrity and privacy cases: */
1293         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1294                                                 + (savedlen - head->iov_len);
1295 out_decode:
1296         status = rpc_call_xdrproc(decode, rqstp, p, obj);
1297 out:
1298         gss_put_ctx(ctx);
1299         dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
1300                         status);
1301         return status;
1302 }
1303
1304 static const struct rpc_authops authgss_ops = {
1305         .owner          = THIS_MODULE,
1306         .au_flavor      = RPC_AUTH_GSS,
1307         .au_name        = "RPCSEC_GSS",
1308         .create         = gss_create,
1309         .destroy        = gss_destroy,
1310         .lookup_cred    = gss_lookup_cred,
1311         .crcreate       = gss_create_cred
1312 };
1313
1314 static const struct rpc_credops gss_credops = {
1315         .cr_name        = "AUTH_GSS",
1316         .crdestroy      = gss_destroy_cred,
1317         .cr_init        = gss_cred_init,
1318         .crbind         = rpcauth_generic_bind_cred,
1319         .crmatch        = gss_match,
1320         .crmarshal      = gss_marshal,
1321         .crrefresh      = gss_refresh,
1322         .crvalidate     = gss_validate,
1323         .crwrap_req     = gss_wrap_req,
1324         .crunwrap_resp  = gss_unwrap_resp,
1325 };
1326
1327 static const struct rpc_credops gss_nullops = {
1328         .cr_name        = "AUTH_GSS",
1329         .crdestroy      = gss_destroy_cred,
1330         .crbind         = rpcauth_generic_bind_cred,
1331         .crmatch        = gss_match,
1332         .crmarshal      = gss_marshal,
1333         .crrefresh      = gss_refresh_null,
1334         .crvalidate     = gss_validate,
1335         .crwrap_req     = gss_wrap_req,
1336         .crunwrap_resp  = gss_unwrap_resp,
1337 };
1338
1339 static struct rpc_pipe_ops gss_upcall_ops = {
1340         .upcall         = gss_pipe_upcall,
1341         .downcall       = gss_pipe_downcall,
1342         .destroy_msg    = gss_pipe_destroy_msg,
1343         .release_pipe   = gss_pipe_release,
1344 };
1345
1346 /*
1347  * Initialize RPCSEC_GSS module
1348  */
1349 static int __init init_rpcsec_gss(void)
1350 {
1351         int err = 0;
1352
1353         err = rpcauth_register(&authgss_ops);
1354         if (err)
1355                 goto out;
1356         err = gss_svc_init();
1357         if (err)
1358                 goto out_unregister;
1359         return 0;
1360 out_unregister:
1361         rpcauth_unregister(&authgss_ops);
1362 out:
1363         return err;
1364 }
1365
1366 static void __exit exit_rpcsec_gss(void)
1367 {
1368         gss_svc_shutdown();
1369         rpcauth_unregister(&authgss_ops);
1370 }
1371
1372 MODULE_LICENSE("GPL");
1373 module_init(init_rpcsec_gss)
1374 module_exit(exit_rpcsec_gss)