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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
  38
  39 #include <linux/module.h>
  40 #include <linux/init.h>
  41 #include <linux/types.h>
  42 #include <linux/slab.h>
  43 #include <linux/sched.h>
  44 #include <linux/pagemap.h>
  45 #include <linux/sunrpc/clnt.h>
  46 #include <linux/sunrpc/auth.h>
  47 #include <linux/sunrpc/auth_gss.h>
  48 #include <linux/sunrpc/svcauth_gss.h>
  49 #include <linux/sunrpc/gss_err.h>
  50 #include <linux/workqueue.h>
  51 #include <linux/sunrpc/rpc_pipe_fs.h>
  52 #include <linux/sunrpc/gss_api.h>
  53 #include <asm/uaccess.h>
  54
  55 static const struct rpc_authops authgss_ops;
  56
  57 static const struct rpc_credops gss_credops;
  58 static const struct rpc_credops gss_nullops;
  59
  60 #ifdef RPC_DEBUG
  61 # define RPCDBG_FACILITY        RPCDBG_AUTH
  62 #endif
  63
  64 #define GSS_CRED_SLACK          1024
  65 /* length of a krb5 verifier (48), plus data added before arguments when
  66  * using integrity (two 4-byte integers): */
  67 #define GSS_VERF_SLACK          100
  68
  69 struct gss_auth {
  70         struct kref kref;
  71         struct rpc_auth rpc_auth;
  72         struct gss_api_mech *mech;
  73         enum rpc_gss_svc service;
  74         struct rpc_clnt *client;
  75         struct dentry *dentry;
  76 };
  77
  78 static void gss_free_ctx(struct gss_cl_ctx *);
  79 static struct rpc_pipe_ops gss_upcall_ops;
  80
  81 static inline struct gss_cl_ctx *
  82 gss_get_ctx(struct gss_cl_ctx *ctx)
  83 {
  84         atomic_inc(&ctx->count);
  85         return ctx;
  86 }
  87
  88 static inline void
  89 gss_put_ctx(struct gss_cl_ctx *ctx)
  90 {
  91         if (atomic_dec_and_test(&ctx->count))
  92                 gss_free_ctx(ctx);
  93 }
  94
  95 /* gss_cred_set_ctx:
  96  * called by gss_upcall_callback and gss_create_upcall in order
  97  * to set the gss context. The actual exchange of an old context
  98  * and a new one is protected by the inode->i_lock.
  99  */
 100 static void
 101 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 102 {
 103         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 104
 105         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 106                 return;
 107         gss_get_ctx(ctx);
 108         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 109         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 110         smp_mb__before_clear_bit();
 111         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 112 }
 113
 114 static const void *
 115 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 116 {
 117         const void *q = (const void *)((const char *)p + len);
 118         if (unlikely(q > end || q < p))
 119                 return ERR_PTR(-EFAULT);
 120         memcpy(res, p, len);
 121         return q;
 122 }
 123
 124 static inline const void *
 125 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 126 {
 127         const void *q;
 128         unsigned int len;
 129
 130         p = simple_get_bytes(p, end, &len, sizeof(len));
 131         if (IS_ERR(p))
 132                 return p;
 133         q = (const void *)((const char *)p + len);
 134         if (unlikely(q > end || q < p))
 135                 return ERR_PTR(-EFAULT);
 136         dest->data = kmemdup(p, len, GFP_NOFS);
 137         if (unlikely(dest->data == NULL))
 138                 return ERR_PTR(-ENOMEM);
 139         dest->len = len;
 140         return q;
 141 }
 142
 143 static struct gss_cl_ctx *
 144 gss_cred_get_ctx(struct rpc_cred *cred)
 145 {
 146         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 147         struct gss_cl_ctx *ctx = NULL;
 148
 149         rcu_read_lock();
 150         if (gss_cred->gc_ctx)
 151                 ctx = gss_get_ctx(gss_cred->gc_ctx);
 152         rcu_read_unlock();
 153         return ctx;
 154 }
 155
 156 static struct gss_cl_ctx *
 157 gss_alloc_context(void)
 158 {
 159         struct gss_cl_ctx *ctx;
 160
 161         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
 162         if (ctx != NULL) {
 163                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 164                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 165                 spin_lock_init(&ctx->gc_seq_lock);
 166                 atomic_set(&ctx->count,1);
 167         }
 168         return ctx;
 169 }
 170
 171 #define GSSD_MIN_TIMEOUT (60 * 60)
 172 static const void *
 173 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 174 {
 175         const void *q;
 176         unsigned int seclen;
 177         unsigned int timeout;
 178         u32 window_size;
 179         int ret;
 180
 181         /* First unsigned int gives the lifetime (in seconds) of the cred */
 182         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 183         if (IS_ERR(p))
 184                 goto err;
 185         if (timeout == 0)
 186                 timeout = GSSD_MIN_TIMEOUT;
 187         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
 188         /* Sequence number window. Determines the maximum number of simultaneous requests */
 189         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 190         if (IS_ERR(p))
 191                 goto err;
 192         ctx->gc_win = window_size;
 193         /* gssd signals an error by passing ctx->gc_win = 0: */
 194         if (ctx->gc_win == 0) {
 195                 /* in which case, p points to  an error code which we ignore */
 196                 p = ERR_PTR(-EACCES);
 197                 goto err;
 198         }
 199         /* copy the opaque wire context */
 200         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 201         if (IS_ERR(p))
 202                 goto err;
 203         /* import the opaque security context */
 204         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 205         if (IS_ERR(p))
 206                 goto err;
 207         q = (const void *)((const char *)p + seclen);
 208         if (unlikely(q > end || q < p)) {
 209                 p = ERR_PTR(-EFAULT);
 210                 goto err;
 211         }
 212         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
 213         if (ret < 0) {
 214                 p = ERR_PTR(ret);
 215                 goto err;
 216         }
 217         return q;
 218 err:
 219         dprintk("RPC:       gss_fill_context returning %ld\n", -PTR_ERR(p));
 220         return p;
 221 }
 222
 223
 224 struct gss_upcall_msg {
 225         atomic_t count;
 226         uid_t   uid;
 227         struct rpc_pipe_msg msg;
 228         struct list_head list;
 229         struct gss_auth *auth;
 230         struct rpc_wait_queue rpc_waitqueue;
 231         wait_queue_head_t waitqueue;
 232         struct gss_cl_ctx *ctx;
 233 };
 234
 235 static void
 236 gss_release_msg(struct gss_upcall_msg *gss_msg)
 237 {
 238         if (!atomic_dec_and_test(&gss_msg->count))
 239                 return;
 240         BUG_ON(!list_empty(&gss_msg->list));
 241         if (gss_msg->ctx != NULL)
 242                 gss_put_ctx(gss_msg->ctx);
 243         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 244         kfree(gss_msg);
 245 }
 246
 247 static struct gss_upcall_msg *
 248 __gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
 249 {
 250         struct gss_upcall_msg *pos;
 251         list_for_each_entry(pos, &rpci->in_downcall, list) {
 252                 if (pos->uid != uid)
 253                         continue;
 254                 atomic_inc(&pos->count);
 255                 dprintk("RPC:       gss_find_upcall found msg %p\n", pos);
 256                 return pos;
 257         }
 258         dprintk("RPC:       gss_find_upcall found nothing\n");
 259         return NULL;
 260 }
 261
 262 /* Try to add an upcall to the pipefs queue.
 263  * If an upcall owned by our uid already exists, then we return a reference
 264  * to that upcall instead of adding the new upcall.
 265  */
 266 static inline struct gss_upcall_msg *
 267 gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
 268 {
 269         struct inode *inode = gss_auth->dentry->d_inode;
 270         struct rpc_inode *rpci = RPC_I(inode);
 271         struct gss_upcall_msg *old;
 272
 273         spin_lock(&inode->i_lock);
 274         old = __gss_find_upcall(rpci, gss_msg->uid);
 275         if (old == NULL) {
 276                 atomic_inc(&gss_msg->count);
 277                 list_add(&gss_msg->list, &rpci->in_downcall);
 278         } else
 279                 gss_msg = old;
 280         spin_unlock(&inode->i_lock);
 281         return gss_msg;
 282 }
 283
 284 static void
 285 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 286 {
 287         list_del_init(&gss_msg->list);
 288         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 289         wake_up_all(&gss_msg->waitqueue);
 290         atomic_dec(&gss_msg->count);
 291 }
 292
 293 static void
 294 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 295 {
 296         struct gss_auth *gss_auth = gss_msg->auth;
 297         struct inode *inode = gss_auth->dentry->d_inode;
 298
 299         if (list_empty(&gss_msg->list))
 300                 return;
 301         spin_lock(&inode->i_lock);
 302         if (!list_empty(&gss_msg->list))
 303                 __gss_unhash_msg(gss_msg);
 304         spin_unlock(&inode->i_lock);
 305 }
 306
 307 static void
 308 gss_upcall_callback(struct rpc_task *task)
 309 {
 310         struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
 311                         struct gss_cred, gc_base);
 312         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 313         struct inode *inode = gss_msg->auth->dentry->d_inode;
 314
 315         spin_lock(&inode->i_lock);
 316         if (gss_msg->ctx)
 317                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
 318         else
 319                 task->tk_status = gss_msg->msg.errno;
 320         gss_cred->gc_upcall = NULL;
 321         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 322         spin_unlock(&inode->i_lock);
 323         gss_release_msg(gss_msg);
 324 }
 325
 326 static inline struct gss_upcall_msg *
 327 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid)
 328 {
 329         struct gss_upcall_msg *gss_msg;
 330
 331         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 332         if (gss_msg != NULL) {
 333                 INIT_LIST_HEAD(&gss_msg->list);
 334                 rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 335                 init_waitqueue_head(&gss_msg->waitqueue);
 336                 atomic_set(&gss_msg->count, 1);
 337                 gss_msg->msg.data = &gss_msg->uid;
 338                 gss_msg->msg.len = sizeof(gss_msg->uid);
 339                 gss_msg->uid = uid;
 340                 gss_msg->auth = gss_auth;
 341         }
 342         return gss_msg;
 343 }
 344
 345 static struct gss_upcall_msg *
 346 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
 347 {
 348         struct gss_cred *gss_cred = container_of(cred,
 349                         struct gss_cred, gc_base);
 350         struct gss_upcall_msg *gss_new, *gss_msg;
 351         uid_t uid = cred->cr_uid;
 352
 353         /* Special case: rpc.gssd assumes that uid == 0 implies machine creds */
 354         if (gss_cred->gc_machine_cred != 0)
 355                 uid = 0;
 356
 357         gss_new = gss_alloc_msg(gss_auth, uid);
 358         if (gss_new == NULL)
 359                 return ERR_PTR(-ENOMEM);
 360         gss_msg = gss_add_msg(gss_auth, gss_new);
 361         if (gss_msg == gss_new) {
 362                 int res = rpc_queue_upcall(gss_auth->dentry->d_inode, &gss_new->msg);
 363                 if (res) {
 364                         gss_unhash_msg(gss_new);
 365                         gss_msg = ERR_PTR(res);
 366                 }
 367         } else
 368                 gss_release_msg(gss_new);
 369         return gss_msg;
 370 }
 371
 372 static void warn_gssd(void)
 373 {
 374         static unsigned long ratelimit;
 375         unsigned long now = jiffies;
 376
 377         if (time_after(now, ratelimit)) {
 378                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 379                                 "Please check user daemon is running.\n");
 380                 ratelimit = now + 15*HZ;
 381         }
 382 }
 383
 384 static inline int
 385 gss_refresh_upcall(struct rpc_task *task)
 386 {
 387         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 388         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 389                         struct gss_auth, rpc_auth);
 390         struct gss_cred *gss_cred = container_of(cred,
 391                         struct gss_cred, gc_base);
 392         struct gss_upcall_msg *gss_msg;
 393         struct inode *inode = gss_auth->dentry->d_inode;
 394         int err = 0;
 395
 396         dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
 397                                                                 cred->cr_uid);
 398         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
 399         if (IS_ERR(gss_msg)) {
 400                 err = PTR_ERR(gss_msg);
 401                 goto out;
 402         }
 403         spin_lock(&inode->i_lock);
 404         if (gss_cred->gc_upcall != NULL)
 405                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 406         else if (gss_msg->ctx != NULL) {
 407                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
 408                 gss_cred->gc_upcall = NULL;
 409                 rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 410         } else if (gss_msg->msg.errno >= 0) {
 411                 task->tk_timeout = 0;
 412                 gss_cred->gc_upcall = gss_msg;
 413                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 414                 atomic_inc(&gss_msg->count);
 415                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 416         } else
 417                 err = gss_msg->msg.errno;
 418         spin_unlock(&inode->i_lock);
 419         gss_release_msg(gss_msg);
 420 out:
 421         dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
 422                         task->tk_pid, cred->cr_uid, err);
 423         return err;
 424 }
 425
 426 static inline int
 427 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 428 {
 429         struct inode *inode = gss_auth->dentry->d_inode;
 430         struct rpc_cred *cred = &gss_cred->gc_base;
 431         struct gss_upcall_msg *gss_msg;
 432         DEFINE_WAIT(wait);
 433         int err = 0;
 434
 435         dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
 436         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 437         if (IS_ERR(gss_msg)) {
 438                 err = PTR_ERR(gss_msg);
 439                 goto out;
 440         }
 441         for (;;) {
 442                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
 443                 spin_lock(&inode->i_lock);
 444                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 445                         break;
 446                 }
 447                 spin_unlock(&inode->i_lock);
 448                 if (signalled()) {
 449                         err = -ERESTARTSYS;
 450                         goto out_intr;
 451                 }
 452                 schedule();
 453         }
 454         if (gss_msg->ctx)
 455                 gss_cred_set_ctx(cred, gss_msg->ctx);
 456         else
 457                 err = gss_msg->msg.errno;
 458         spin_unlock(&inode->i_lock);
 459 out_intr:
 460         finish_wait(&gss_msg->waitqueue, &wait);
 461         gss_release_msg(gss_msg);
 462 out:
 463         dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
 464                         cred->cr_uid, err);
 465         return err;
 466 }
 467
 468 static ssize_t
 469 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 470                 char __user *dst, size_t buflen)
 471 {
 472         char *data = (char *)msg->data + msg->copied;
 473         size_t mlen = min(msg->len, buflen);
 474         unsigned long left;
 475
 476         left = copy_to_user(dst, data, mlen);
 477         if (left == mlen) {
 478                 msg->errno = -EFAULT;
 479                 return -EFAULT;
 480         }
 481
 482         mlen -= left;
 483         msg->copied += mlen;
 484         msg->errno = 0;
 485         return mlen;
 486 }
 487
 488 #define MSG_BUF_MAXSIZE 1024
 489
 490 static ssize_t
 491 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 492 {
 493         const void *p, *end;
 494         void *buf;
 495         struct gss_upcall_msg *gss_msg;
 496         struct inode *inode = filp->f_path.dentry->d_inode;
 497         struct gss_cl_ctx *ctx;
 498         uid_t uid;
 499         ssize_t err = -EFBIG;
 500
 501         if (mlen > MSG_BUF_MAXSIZE)
 502                 goto out;
 503         err = -ENOMEM;
 504         buf = kmalloc(mlen, GFP_NOFS);
 505         if (!buf)
 506                 goto out;
 507
 508         err = -EFAULT;
 509         if (copy_from_user(buf, src, mlen))
 510                 goto err;
 511
 512         end = (const void *)((char *)buf + mlen);
 513         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
 514         if (IS_ERR(p)) {
 515                 err = PTR_ERR(p);
 516                 goto err;
 517         }
 518
 519         err = -ENOMEM;
 520         ctx = gss_alloc_context();
 521         if (ctx == NULL)
 522                 goto err;
 523
 524         err = -ENOENT;
 525         /* Find a matching upcall */
 526         spin_lock(&inode->i_lock);
 527         gss_msg = __gss_find_upcall(RPC_I(inode), uid);
 528         if (gss_msg == NULL) {
 529                 spin_unlock(&inode->i_lock);
 530                 goto err_put_ctx;
 531         }
 532         list_del_init(&gss_msg->list);
 533         spin_unlock(&inode->i_lock);
 534
 535         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 536         if (IS_ERR(p)) {
 537                 err = PTR_ERR(p);
 538                 gss_msg->msg.errno = (err == -EAGAIN) ? -EAGAIN : -EACCES;
 539                 goto err_release_msg;
 540         }
 541         gss_msg->ctx = gss_get_ctx(ctx);
 542         err = mlen;
 543
 544 err_release_msg:
 545         spin_lock(&inode->i_lock);
 546         __gss_unhash_msg(gss_msg);
 547         spin_unlock(&inode->i_lock);
 548         gss_release_msg(gss_msg);
 549 err_put_ctx:
 550         gss_put_ctx(ctx);
 551 err:
 552         kfree(buf);
 553 out:
 554         dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
 555         return err;
 556 }
 557
 558 static void
 559 gss_pipe_release(struct inode *inode)
 560 {
 561         struct rpc_inode *rpci = RPC_I(inode);
 562         struct gss_upcall_msg *gss_msg;
 563
 564         spin_lock(&inode->i_lock);
 565         while (!list_empty(&rpci->in_downcall)) {
 566
 567                 gss_msg = list_entry(rpci->in_downcall.next,
 568                                 struct gss_upcall_msg, list);
 569                 gss_msg->msg.errno = -EPIPE;
 570                 atomic_inc(&gss_msg->count);
 571                 __gss_unhash_msg(gss_msg);
 572                 spin_unlock(&inode->i_lock);
 573                 gss_release_msg(gss_msg);
 574                 spin_lock(&inode->i_lock);
 575         }
 576         spin_unlock(&inode->i_lock);
 577 }
 578
 579 static void
 580 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 581 {
 582         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 583
 584         if (msg->errno < 0) {
 585                 dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
 586                                 gss_msg);
 587                 atomic_inc(&gss_msg->count);
 588                 gss_unhash_msg(gss_msg);
 589                 if (msg->errno == -ETIMEDOUT)
 590                         warn_gssd();
 591                 gss_release_msg(gss_msg);
 592         }
 593 }
 594
 595 /*
 596  * NOTE: we have the opportunity to use different
 597  * parameters based on the input flavor (which must be a pseudoflavor)
 598  */
 599 static struct rpc_auth *
 600 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 601 {
 602         struct gss_auth *gss_auth;
 603         struct rpc_auth * auth;
 604         int err = -ENOMEM; /* XXX? */
 605
 606         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 607
 608         if (!try_module_get(THIS_MODULE))
 609                 return ERR_PTR(err);
 610         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 611                 goto out_dec;
 612         gss_auth->client = clnt;
 613         err = -EINVAL;
 614         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 615         if (!gss_auth->mech) {
 616                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
 617                                 __func__, flavor);
 618                 goto err_free;
 619         }
 620         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 621         if (gss_auth->service == 0)
 622                 goto err_put_mech;
 623         auth = &gss_auth->rpc_auth;
 624         auth->au_cslack = GSS_CRED_SLACK >> 2;
 625         auth->au_rslack = GSS_VERF_SLACK >> 2;
 626         auth->au_ops = &authgss_ops;
 627         auth->au_flavor = flavor;
 628         atomic_set(&auth->au_count, 1);
 629         kref_init(&gss_auth->kref);
 630
 631         gss_auth->dentry = rpc_mkpipe(clnt->cl_dentry, gss_auth->mech->gm_name,
 632                         clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 633         if (IS_ERR(gss_auth->dentry)) {
 634                 err = PTR_ERR(gss_auth->dentry);
 635                 goto err_put_mech;
 636         }
 637
 638         err = rpcauth_init_credcache(auth);
 639         if (err)
 640                 goto err_unlink_pipe;
 641
 642         return auth;
 643 err_unlink_pipe:
 644         rpc_unlink(gss_auth->dentry);
 645 err_put_mech:
 646         gss_mech_put(gss_auth->mech);
 647 err_free:
 648         kfree(gss_auth);
 649 out_dec:
 650         module_put(THIS_MODULE);
 651         return ERR_PTR(err);
 652 }
 653
 654 static void
 655 gss_free(struct gss_auth *gss_auth)
 656 {
 657         rpc_unlink(gss_auth->dentry);
 658         gss_mech_put(gss_auth->mech);
 659
 660         kfree(gss_auth);
 661         module_put(THIS_MODULE);
 662 }
 663
 664 static void
 665 gss_free_callback(struct kref *kref)
 666 {
 667         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
 668
 669         gss_free(gss_auth);
 670 }
 671
 672 static void
 673 gss_destroy(struct rpc_auth *auth)
 674 {
 675         struct gss_auth *gss_auth;
 676
 677         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
 678                         auth, auth->au_flavor);
 679
 680         rpcauth_destroy_credcache(auth);
 681
 682         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 683         kref_put(&gss_auth->kref, gss_free_callback);
 684 }
 685
 686 /*
 687  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
 688  * to the server with the GSS control procedure field set to
 689  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
 690  * all RPCSEC_GSS state associated with that context.
 691  */
 692 static int
 693 gss_destroying_context(struct rpc_cred *cred)
 694 {
 695         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 696         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 697         struct rpc_task *task;
 698
 699         if (gss_cred->gc_ctx == NULL ||
 700             test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 701                 return 0;
 702
 703         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
 704         cred->cr_ops = &gss_nullops;
 705
 706         /* Take a reference to ensure the cred will be destroyed either
 707          * by the RPC call or by the put_rpccred() below */
 708         get_rpccred(cred);
 709
 710         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
 711         if (!IS_ERR(task))
 712                 rpc_put_task(task);
 713
 714         put_rpccred(cred);
 715         return 1;
 716 }
 717
 718 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
 719  * to create a new cred or context, so they check that things have been
 720  * allocated before freeing them. */
 721 static void
 722 gss_do_free_ctx(struct gss_cl_ctx *ctx)
 723 {
 724         dprintk("RPC:       gss_free_ctx\n");
 725
 726         kfree(ctx->gc_wire_ctx.data);
 727         kfree(ctx);
 728 }
 729
 730 static void
 731 gss_free_ctx_callback(struct rcu_head *head)
 732 {
 733         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
 734         gss_do_free_ctx(ctx);
 735 }
 736
 737 static void
 738 gss_free_ctx(struct gss_cl_ctx *ctx)
 739 {
 740         struct gss_ctx *gc_gss_ctx;
 741
 742         gc_gss_ctx = rcu_dereference(ctx->gc_gss_ctx);
 743         rcu_assign_pointer(ctx->gc_gss_ctx, NULL);
 744         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
 745         if (gc_gss_ctx)
 746                 gss_delete_sec_context(&gc_gss_ctx);
 747 }
 748
 749 static void
 750 gss_free_cred(struct gss_cred *gss_cred)
 751 {
 752         dprintk("RPC:       gss_free_cred %p\n", gss_cred);
 753         kfree(gss_cred);
 754 }
 755
 756 static void
 757 gss_free_cred_callback(struct rcu_head *head)
 758 {
 759         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
 760         gss_free_cred(gss_cred);
 761 }
 762
 763 static void
 764 gss_destroy_nullcred(struct rpc_cred *cred)
 765 {
 766         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 767         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 768         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
 769
 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 static void
 778 gss_destroy_cred(struct rpc_cred *cred)
 779 {
 780
 781         if (gss_destroying_context(cred))
 782                 return;
 783         gss_destroy_nullcred(cred);
 784 }
 785
 786 /*
 787  * Lookup RPCSEC_GSS cred for the current process
 788  */
 789 static struct rpc_cred *
 790 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 791 {
 792         return rpcauth_lookup_credcache(auth, acred, flags);
 793 }
 794
 795 static struct rpc_cred *
 796 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 797 {
 798         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 799         struct gss_cred *cred = NULL;
 800         int err = -ENOMEM;
 801
 802         dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
 803                 acred->uid, auth->au_flavor);
 804
 805         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
 806                 goto out_err;
 807
 808         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
 809         /*
 810          * Note: in order to force a call to call_refresh(), we deliberately
 811          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
 812          */
 813         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
 814         cred->gc_service = gss_auth->service;
 815         cred->gc_machine_cred = acred->machine_cred;
 816         kref_get(&gss_auth->kref);
 817         return &cred->gc_base;
 818
 819 out_err:
 820         dprintk("RPC:       gss_create_cred failed with error %d\n", err);
 821         return ERR_PTR(err);
 822 }
 823
 824 static int
 825 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
 826 {
 827         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 828         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
 829         int err;
 830
 831         do {
 832                 err = gss_create_upcall(gss_auth, gss_cred);
 833         } while (err == -EAGAIN);
 834         return err;
 835 }
 836
 837 static int
 838 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
 839 {
 840         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
 841
 842         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
 843                 goto out;
 844         /* Don't match with creds that have expired. */
 845         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
 846                 return 0;
 847         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
 848                 return 0;
 849 out:
 850         if (acred->machine_cred != gss_cred->gc_machine_cred)
 851                 return 0;
 852         return (rc->cr_uid == acred->uid);
 853 }
 854
 855 /*
 856 * Marshal credentials.
 857 * Maybe we should keep a cached credential for performance reasons.
 858 */
 859 static __be32 *
 860 gss_marshal(struct rpc_task *task, __be32 *p)
 861 {
 862         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 863         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
 864                                                  gc_base);
 865         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
 866         __be32          *cred_len;
 867         struct rpc_rqst *req = task->tk_rqstp;
 868         u32             maj_stat = 0;
 869         struct xdr_netobj mic;
 870         struct kvec     iov;
 871         struct xdr_buf  verf_buf;
 872
 873         dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
 874
 875         *p++ = htonl(RPC_AUTH_GSS);
 876         cred_len = p++;
 877
 878         spin_lock(&ctx->gc_seq_lock);
 879         req->rq_seqno = ctx->gc_seq++;
 880         spin_unlock(&ctx->gc_seq_lock);
 881
 882         *p++ = htonl((u32) RPC_GSS_VERSION);
 883         *p++ = htonl((u32) ctx->gc_proc);
 884         *p++ = htonl((u32) req->rq_seqno);
 885         *p++ = htonl((u32) gss_cred->gc_service);
 886         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
 887         *cred_len = htonl((p - (cred_len + 1)) << 2);
 888
 889         /* We compute the checksum for the verifier over the xdr-encoded bytes
 890          * starting with the xid and ending at the end of the credential: */
 891         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
 892                                         req->rq_snd_buf.head[0].iov_base);
 893         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
 894         xdr_buf_from_iov(&iov, &verf_buf);
 895
 896         /* set verifier flavor*/
 897         *p++ = htonl(RPC_AUTH_GSS);
 898
 899         mic.data = (u8 *)(p + 1);
 900         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 901         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
 902                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 903         } else if (maj_stat != 0) {
 904                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
 905                 goto out_put_ctx;
 906         }
 907         p = xdr_encode_opaque(p, NULL, mic.len);
 908         gss_put_ctx(ctx);
 909         return p;
 910 out_put_ctx:
 911         gss_put_ctx(ctx);
 912         return NULL;
 913 }
 914
 915 static int gss_renew_cred(struct rpc_task *task)
 916 {
 917         struct rpc_cred *oldcred = task->tk_msg.rpc_cred;
 918         struct gss_cred *gss_cred = container_of(oldcred,
 919                                                  struct gss_cred,
 920                                                  gc_base);
 921         struct rpc_auth *auth = oldcred->cr_auth;
 922         struct auth_cred acred = {
 923                 .uid = oldcred->cr_uid,
 924                 .machine_cred = gss_cred->gc_machine_cred,
 925         };
 926         struct rpc_cred *new;
 927
 928         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
 929         if (IS_ERR(new))
 930                 return PTR_ERR(new);
 931         task->tk_msg.rpc_cred = new;
 932         put_rpccred(oldcred);
 933         return 0;
 934 }
 935
 936 /*
 937 * Refresh credentials. XXX - finish
 938 */
 939 static int
 940 gss_refresh(struct rpc_task *task)
 941 {
 942         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 943         int ret = 0;
 944
 945         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
 946                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
 947                 ret = gss_renew_cred(task);
 948                 if (ret < 0)
 949                         goto out;
 950                 cred = task->tk_msg.rpc_cred;
 951         }
 952
 953         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 954                 ret = gss_refresh_upcall(task);
 955 out:
 956         return ret;
 957 }
 958
 959 /* Dummy refresh routine: used only when destroying the context */
 960 static int
 961 gss_refresh_null(struct rpc_task *task)
 962 {
 963         return -EACCES;
 964 }
 965
 966 static __be32 *
 967 gss_validate(struct rpc_task *task, __be32 *p)
 968 {
 969         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 970         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
 971         __be32          seq;
 972         struct kvec     iov;
 973         struct xdr_buf  verf_buf;
 974         struct xdr_netobj mic;
 975         u32             flav,len;
 976         u32             maj_stat;
 977
 978         dprintk("RPC: %5u gss_validate\n", task->tk_pid);
 979
 980         flav = ntohl(*p++);
 981         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
 982                 goto out_bad;
 983         if (flav != RPC_AUTH_GSS)
 984                 goto out_bad;
 985         seq = htonl(task->tk_rqstp->rq_seqno);
 986         iov.iov_base = &seq;
 987         iov.iov_len = sizeof(seq);
 988         xdr_buf_from_iov(&iov, &verf_buf);
 989         mic.data = (u8 *)p;
 990         mic.len = len;
 991
 992         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 993         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
 994                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 995         if (maj_stat) {
 996                 dprintk("RPC: %5u gss_validate: gss_verify_mic returned "
 997                                 "error 0x%08x\n", task->tk_pid, maj_stat);
 998                 goto out_bad;
 999         }
1000         /* We leave it to unwrap to calculate au_rslack. For now we just
1001          * calculate the length of the verifier: */
1002         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1003         gss_put_ctx(ctx);
1004         dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
1005                         task->tk_pid);
1006         return p + XDR_QUADLEN(len);
1007 out_bad:
1008         gss_put_ctx(ctx);
1009         dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
1010         return NULL;
1011 }
1012
1013 static inline int
1014 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1015                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1016 {
1017         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1018         struct xdr_buf  integ_buf;
1019         __be32          *integ_len = NULL;
1020         struct xdr_netobj mic;
1021         u32             offset;
1022         __be32          *q;
1023         struct kvec     *iov;
1024         u32             maj_stat = 0;
1025         int             status = -EIO;
1026
1027         integ_len = p++;
1028         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1029         *p++ = htonl(rqstp->rq_seqno);
1030
1031         status = encode(rqstp, p, obj);
1032         if (status)
1033                 return status;
1034
1035         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1036                                 offset, snd_buf->len - offset))
1037                 return status;
1038         *integ_len = htonl(integ_buf.len);
1039
1040         /* guess whether we're in the head or the tail: */
1041         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1042                 iov = snd_buf->tail;
1043         else
1044                 iov = snd_buf->head;
1045         p = iov->iov_base + iov->iov_len;
1046         mic.data = (u8 *)(p + 1);
1047
1048         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1049         status = -EIO; /* XXX? */
1050         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1051                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1052         else if (maj_stat)
1053                 return status;
1054         q = xdr_encode_opaque(p, NULL, mic.len);
1055
1056         offset = (u8 *)q - (u8 *)p;
1057         iov->iov_len += offset;
1058         snd_buf->len += offset;
1059         return 0;
1060 }
1061
1062 static void
1063 priv_release_snd_buf(struct rpc_rqst *rqstp)
1064 {
1065         int i;
1066
1067         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1068                 __free_page(rqstp->rq_enc_pages[i]);
1069         kfree(rqstp->rq_enc_pages);
1070 }
1071
1072 static int
1073 alloc_enc_pages(struct rpc_rqst *rqstp)
1074 {
1075         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1076         int first, last, i;
1077
1078         if (snd_buf->page_len == 0) {
1079                 rqstp->rq_enc_pages_num = 0;
1080                 return 0;
1081         }
1082
1083         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1084         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1085         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1086         rqstp->rq_enc_pages
1087                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1088                                 GFP_NOFS);
1089         if (!rqstp->rq_enc_pages)
1090                 goto out;
1091         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1092                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1093                 if (rqstp->rq_enc_pages[i] == NULL)
1094                         goto out_free;
1095         }
1096         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1097         return 0;
1098 out_free:
1099         for (i--; i >= 0; i--) {
1100                 __free_page(rqstp->rq_enc_pages[i]);
1101         }
1102 out:
1103         return -EAGAIN;
1104 }
1105
1106 static inline int
1107 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1108                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1109 {
1110         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1111         u32             offset;
1112         u32             maj_stat;
1113         int             status;
1114         __be32          *opaque_len;
1115         struct page     **inpages;
1116         int             first;
1117         int             pad;
1118         struct kvec     *iov;
1119         char            *tmp;
1120
1121         opaque_len = p++;
1122         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1123         *p++ = htonl(rqstp->rq_seqno);
1124
1125         status = encode(rqstp, p, obj);
1126         if (status)
1127                 return status;
1128
1129         status = alloc_enc_pages(rqstp);
1130         if (status)
1131                 return status;
1132         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1133         inpages = snd_buf->pages + first;
1134         snd_buf->pages = rqstp->rq_enc_pages;
1135         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1136         /* Give the tail its own page, in case we need extra space in the
1137          * head when wrapping: */
1138         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1139                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1140                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1141                 snd_buf->tail[0].iov_base = tmp;
1142         }
1143         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1144         /* RPC_SLACK_SPACE should prevent this ever happening: */
1145         BUG_ON(snd_buf->len > snd_buf->buflen);
1146         status = -EIO;
1147         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1148          * done anyway, so it's safe to put the request on the wire: */
1149         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1150                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1151         else if (maj_stat)
1152                 return status;
1153
1154         *opaque_len = htonl(snd_buf->len - offset);
1155         /* guess whether we're in the head or the tail: */
1156         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1157                 iov = snd_buf->tail;
1158         else
1159                 iov = snd_buf->head;
1160         p = iov->iov_base + iov->iov_len;
1161         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1162         memset(p, 0, pad);
1163         iov->iov_len += pad;
1164         snd_buf->len += pad;
1165
1166         return 0;
1167 }
1168
1169 static int
1170 gss_wrap_req(struct rpc_task *task,
1171              kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
1172 {
1173         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1174         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1175                         gc_base);
1176         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1177         int             status = -EIO;
1178
1179         dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
1180         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1181                 /* The spec seems a little ambiguous here, but I think that not
1182                  * wrapping context destruction requests makes the most sense.
1183                  */
1184                 status = encode(rqstp, p, obj);
1185                 goto out;
1186         }
1187         switch (gss_cred->gc_service) {
1188                 case RPC_GSS_SVC_NONE:
1189                         status = encode(rqstp, p, obj);
1190                         break;
1191                 case RPC_GSS_SVC_INTEGRITY:
1192                         status = gss_wrap_req_integ(cred, ctx, encode,
1193                                                                 rqstp, p, obj);
1194                         break;
1195                 case RPC_GSS_SVC_PRIVACY:
1196                         status = gss_wrap_req_priv(cred, ctx, encode,
1197                                         rqstp, p, obj);
1198                         break;
1199         }
1200 out:
1201         gss_put_ctx(ctx);
1202         dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
1203         return status;
1204 }
1205
1206 static inline int
1207 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1208                 struct rpc_rqst *rqstp, __be32 **p)
1209 {
1210         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1211         struct xdr_buf integ_buf;
1212         struct xdr_netobj mic;
1213         u32 data_offset, mic_offset;
1214         u32 integ_len;
1215         u32 maj_stat;
1216         int status = -EIO;
1217
1218         integ_len = ntohl(*(*p)++);
1219         if (integ_len & 3)
1220                 return status;
1221         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1222         mic_offset = integ_len + data_offset;
1223         if (mic_offset > rcv_buf->len)
1224                 return status;
1225         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1226                 return status;
1227
1228         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1229                                 mic_offset - data_offset))
1230                 return status;
1231
1232         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1233                 return status;
1234
1235         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1236         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1237                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1238         if (maj_stat != GSS_S_COMPLETE)
1239                 return status;
1240         return 0;
1241 }
1242
1243 static inline int
1244 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1245                 struct rpc_rqst *rqstp, __be32 **p)
1246 {
1247         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1248         u32 offset;
1249         u32 opaque_len;
1250         u32 maj_stat;
1251         int status = -EIO;
1252
1253         opaque_len = ntohl(*(*p)++);
1254         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1255         if (offset + opaque_len > rcv_buf->len)
1256                 return status;
1257         /* remove padding: */
1258         rcv_buf->len = offset + opaque_len;
1259
1260         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1261         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1262                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1263         if (maj_stat != GSS_S_COMPLETE)
1264                 return status;
1265         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1266                 return status;
1267
1268         return 0;
1269 }
1270
1271
1272 static int
1273 gss_unwrap_resp(struct rpc_task *task,
1274                 kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
1275 {
1276         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1277         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1278                         gc_base);
1279         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1280         __be32          *savedp = p;
1281         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1282         int             savedlen = head->iov_len;
1283         int             status = -EIO;
1284
1285         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1286                 goto out_decode;
1287         switch (gss_cred->gc_service) {
1288                 case RPC_GSS_SVC_NONE:
1289                         break;
1290                 case RPC_GSS_SVC_INTEGRITY:
1291                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1292                         if (status)
1293                                 goto out;
1294                         break;
1295                 case RPC_GSS_SVC_PRIVACY:
1296                         status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1297                         if (status)
1298                                 goto out;
1299                         break;
1300         }
1301         /* take into account extra slack for integrity and privacy cases: */
1302         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1303                                                 + (savedlen - head->iov_len);
1304 out_decode:
1305         status = decode(rqstp, p, obj);
1306 out:
1307         gss_put_ctx(ctx);
1308         dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
1309                         status);
1310         return status;
1311 }
1312
1313 static const struct rpc_authops authgss_ops = {
1314         .owner          = THIS_MODULE,
1315         .au_flavor      = RPC_AUTH_GSS,
1316         .au_name        = "RPCSEC_GSS",
1317         .create         = gss_create,
1318         .destroy        = gss_destroy,
1319         .lookup_cred    = gss_lookup_cred,
1320         .crcreate       = gss_create_cred
1321 };
1322
1323 static const struct rpc_credops gss_credops = {
1324         .cr_name        = "AUTH_GSS",
1325         .crdestroy      = gss_destroy_cred,
1326         .cr_init        = gss_cred_init,
1327         .crbind         = rpcauth_generic_bind_cred,
1328         .crmatch        = gss_match,
1329         .crmarshal      = gss_marshal,
1330         .crrefresh      = gss_refresh,
1331         .crvalidate     = gss_validate,
1332         .crwrap_req     = gss_wrap_req,
1333         .crunwrap_resp  = gss_unwrap_resp,
1334 };
1335
1336 static const struct rpc_credops gss_nullops = {
1337         .cr_name        = "AUTH_GSS",
1338         .crdestroy      = gss_destroy_nullcred,
1339         .crbind         = rpcauth_generic_bind_cred,
1340         .crmatch        = gss_match,
1341         .crmarshal      = gss_marshal,
1342         .crrefresh      = gss_refresh_null,
1343         .crvalidate     = gss_validate,
1344         .crwrap_req     = gss_wrap_req,
1345         .crunwrap_resp  = gss_unwrap_resp,
1346 };
1347
1348 static struct rpc_pipe_ops gss_upcall_ops = {
1349         .upcall         = gss_pipe_upcall,
1350         .downcall       = gss_pipe_downcall,
1351         .destroy_msg    = gss_pipe_destroy_msg,
1352         .release_pipe   = gss_pipe_release,
1353 };
1354
1355 /*
1356  * Initialize RPCSEC_GSS module
1357  */
1358 static int __init init_rpcsec_gss(void)
1359 {
1360         int err = 0;
1361
1362         err = rpcauth_register(&authgss_ops);
1363         if (err)
1364                 goto out;
1365         err = gss_svc_init();
1366         if (err)
1367                 goto out_unregister;
1368         return 0;
1369 out_unregister:
1370         rpcauth_unregister(&authgss_ops);
1371 out:
1372         return err;
1373 }
1374
1375 static void __exit exit_rpcsec_gss(void)
1376 {
1377         gss_svc_shutdown();
1378         rpcauth_unregister(&authgss_ops);
1379 }
1380
1381 MODULE_LICENSE("GPL");
1382 module_init(init_rpcsec_gss)
1383 module_exit(exit_rpcsec_gss)