net/sunrpc/auth_gss/auth_gss.c

   1 /*
   2  * linux/net/sunrpc/auth_gss/auth_gss.c
   3  *
   4  * RPCSEC_GSS client authentication.
   5  *
   6  *  Copyright (c) 2000 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Dug Song       <dugsong@monkey.org>
  10  *  Andy Adamson   <andros@umich.edu>
  11  *
  12  *  Redistribution and use in source and binary forms, with or without
  13  *  modification, are permitted provided that the following conditions
  14  *  are met:
  15  *
  16  *  1. Redistributions of source code must retain the above copyright
  17  *     notice, this list of conditions and the following disclaimer.
  18  *  2. Redistributions in binary form must reproduce the above copyright
  19  *     notice, this list of conditions and the following disclaimer in the
  20  *     documentation and/or other materials provided with the distribution.
  21  *  3. Neither the name of the University nor the names of its
  22  *     contributors may be used to endorse or promote products derived
  23  *     from this software without specific prior written permission.
  24  *
  25  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  26  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  27  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  28  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  32  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  33  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  34  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  35  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  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 /* pipe_version >= 0 if and only if someone has a pipe open. */
  79 static int pipe_version = -1;
  80 static atomic_t pipe_users = ATOMIC_INIT(0);
  81 static DEFINE_SPINLOCK(pipe_version_lock);
  82 static struct rpc_wait_queue pipe_version_rpc_waitqueue;
  83 static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
  84
  85 static void gss_free_ctx(struct gss_cl_ctx *);
  86 static struct rpc_pipe_ops gss_upcall_ops;
  87
  88 static inline struct gss_cl_ctx *
  89 gss_get_ctx(struct gss_cl_ctx *ctx)
  90 {
  91         atomic_inc(&ctx->count);
  92         return ctx;
  93 }
  94
  95 static inline void
  96 gss_put_ctx(struct gss_cl_ctx *ctx)
  97 {
  98         if (atomic_dec_and_test(&ctx->count))
  99                 gss_free_ctx(ctx);
 100 }
 101
 102 /* gss_cred_set_ctx:
 103  * called by gss_upcall_callback and gss_create_upcall in order
 104  * to set the gss context. The actual exchange of an old context
 105  * and a new one is protected by the inode->i_lock.
 106  */
 107 static void
 108 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 109 {
 110         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 111
 112         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 113                 return;
 114         gss_get_ctx(ctx);
 115         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 116         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 117         smp_mb__before_clear_bit();
 118         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 119 }
 120
 121 static const void *
 122 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 123 {
 124         const void *q = (const void *)((const char *)p + len);
 125         if (unlikely(q > end || q < p))
 126                 return ERR_PTR(-EFAULT);
 127         memcpy(res, p, len);
 128         return q;
 129 }
 130
 131 static inline const void *
 132 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 133 {
 134         const void *q;
 135         unsigned int len;
 136
 137         p = simple_get_bytes(p, end, &len, sizeof(len));
 138         if (IS_ERR(p))
 139                 return p;
 140         q = (const void *)((const char *)p + len);
 141         if (unlikely(q > end || q < p))
 142                 return ERR_PTR(-EFAULT);
 143         dest->data = kmemdup(p, len, GFP_NOFS);
 144         if (unlikely(dest->data == NULL))
 145                 return ERR_PTR(-ENOMEM);
 146         dest->len = len;
 147         return q;
 148 }
 149
 150 static struct gss_cl_ctx *
 151 gss_cred_get_ctx(struct rpc_cred *cred)
 152 {
 153         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 154         struct gss_cl_ctx *ctx = NULL;
 155
 156         rcu_read_lock();
 157         if (gss_cred->gc_ctx)
 158                 ctx = gss_get_ctx(gss_cred->gc_ctx);
 159         rcu_read_unlock();
 160         return ctx;
 161 }
 162
 163 static struct gss_cl_ctx *
 164 gss_alloc_context(void)
 165 {
 166         struct gss_cl_ctx *ctx;
 167
 168         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
 169         if (ctx != NULL) {
 170                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 171                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 172                 spin_lock_init(&ctx->gc_seq_lock);
 173                 atomic_set(&ctx->count,1);
 174         }
 175         return ctx;
 176 }
 177
 178 #define GSSD_MIN_TIMEOUT (60 * 60)
 179 static const void *
 180 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 181 {
 182         const void *q;
 183         unsigned int seclen;
 184         unsigned int timeout;
 185         u32 window_size;
 186         int ret;
 187
 188         /* First unsigned int gives the lifetime (in seconds) of the cred */
 189         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 190         if (IS_ERR(p))
 191                 goto err;
 192         if (timeout == 0)
 193                 timeout = GSSD_MIN_TIMEOUT;
 194         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
 195         /* Sequence number window. Determines the maximum number of simultaneous requests */
 196         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 197         if (IS_ERR(p))
 198                 goto err;
 199         ctx->gc_win = window_size;
 200         /* gssd signals an error by passing ctx->gc_win = 0: */
 201         if (ctx->gc_win == 0) {
 202                 /* in which case, p points to  an error code which we ignore */
 203                 p = ERR_PTR(-EACCES);
 204                 goto err;
 205         }
 206         /* copy the opaque wire context */
 207         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 208         if (IS_ERR(p))
 209                 goto err;
 210         /* import the opaque security context */
 211         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 212         if (IS_ERR(p))
 213                 goto err;
 214         q = (const void *)((const char *)p + seclen);
 215         if (unlikely(q > end || q < p)) {
 216                 p = ERR_PTR(-EFAULT);
 217                 goto err;
 218         }
 219         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
 220         if (ret < 0) {
 221                 p = ERR_PTR(ret);
 222                 goto err;
 223         }
 224         return q;
 225 err:
 226         dprintk("RPC:       gss_fill_context returning %ld\n", -PTR_ERR(p));
 227         return p;
 228 }
 229
 230
 231 struct gss_upcall_msg {
 232         atomic_t count;
 233         uid_t   uid;
 234         struct rpc_pipe_msg msg;
 235         struct list_head list;
 236         struct gss_auth *auth;
 237         struct rpc_inode *inode;
 238         struct rpc_wait_queue rpc_waitqueue;
 239         wait_queue_head_t waitqueue;
 240         struct gss_cl_ctx *ctx;
 241 };
 242
 243 static int get_pipe_version(void)
 244 {
 245         int ret;
 246
 247         spin_lock(&pipe_version_lock);
 248         if (pipe_version >= 0) {
 249                 atomic_inc(&pipe_users);
 250                 ret = 0;
 251         } else
 252                 ret = -EAGAIN;
 253         spin_unlock(&pipe_version_lock);
 254         return ret;
 255 }
 256
 257 static void put_pipe_version(void)
 258 {
 259         if (atomic_dec_and_lock(&pipe_users, &pipe_version_lock)) {
 260                 pipe_version = -1;
 261                 spin_unlock(&pipe_version_lock);
 262         }
 263 }
 264
 265 static void
 266 gss_release_msg(struct gss_upcall_msg *gss_msg)
 267 {
 268         if (!atomic_dec_and_test(&gss_msg->count))
 269                 return;
 270         put_pipe_version();
 271         BUG_ON(!list_empty(&gss_msg->list));
 272         if (gss_msg->ctx != NULL)
 273                 gss_put_ctx(gss_msg->ctx);
 274         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 275         kfree(gss_msg);
 276 }
 277
 278 static struct gss_upcall_msg *
 279 __gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
 280 {
 281         struct gss_upcall_msg *pos;
 282         list_for_each_entry(pos, &rpci->in_downcall, list) {
 283                 if (pos->uid != uid)
 284                         continue;
 285                 atomic_inc(&pos->count);
 286                 dprintk("RPC:       gss_find_upcall found msg %p\n", pos);
 287                 return pos;
 288         }
 289         dprintk("RPC:       gss_find_upcall found nothing\n");
 290         return NULL;
 291 }
 292
 293 /* Try to add an upcall to the pipefs queue.
 294  * If an upcall owned by our uid already exists, then we return a reference
 295  * to that upcall instead of adding the new upcall.
 296  */
 297 static inline struct gss_upcall_msg *
 298 gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
 299 {
 300         struct rpc_inode *rpci = gss_msg->inode;
 301         struct inode *inode = &rpci->vfs_inode;
 302         struct gss_upcall_msg *old;
 303
 304         spin_lock(&inode->i_lock);
 305         old = __gss_find_upcall(rpci, gss_msg->uid);
 306         if (old == NULL) {
 307                 atomic_inc(&gss_msg->count);
 308                 list_add(&gss_msg->list, &rpci->in_downcall);
 309         } else
 310                 gss_msg = old;
 311         spin_unlock(&inode->i_lock);
 312         return gss_msg;
 313 }
 314
 315 static void
 316 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 317 {
 318         list_del_init(&gss_msg->list);
 319         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 320         wake_up_all(&gss_msg->waitqueue);
 321         atomic_dec(&gss_msg->count);
 322 }
 323
 324 static void
 325 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 326 {
 327         struct inode *inode = &gss_msg->inode->vfs_inode;
 328
 329         if (list_empty(&gss_msg->list))
 330                 return;
 331         spin_lock(&inode->i_lock);
 332         if (!list_empty(&gss_msg->list))
 333                 __gss_unhash_msg(gss_msg);
 334         spin_unlock(&inode->i_lock);
 335 }
 336
 337 static void
 338 gss_upcall_callback(struct rpc_task *task)
 339 {
 340         struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
 341                         struct gss_cred, gc_base);
 342         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 343         struct inode *inode = &gss_msg->inode->vfs_inode;
 344
 345         spin_lock(&inode->i_lock);
 346         if (gss_msg->ctx)
 347                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
 348         else
 349                 task->tk_status = gss_msg->msg.errno;
 350         gss_cred->gc_upcall = NULL;
 351         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 352         spin_unlock(&inode->i_lock);
 353         gss_release_msg(gss_msg);
 354 }
 355
 356 static inline struct gss_upcall_msg *
 357 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid)
 358 {
 359         struct gss_upcall_msg *gss_msg;
 360         int vers;
 361
 362         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 363         if (gss_msg == NULL)
 364                 return ERR_PTR(-ENOMEM);
 365         vers = get_pipe_version();
 366         if (vers < 0) {
 367                 kfree(gss_msg);
 368                 return ERR_PTR(vers);
 369         }
 370         gss_msg->inode = RPC_I(gss_auth->dentry->d_inode);
 371         INIT_LIST_HEAD(&gss_msg->list);
 372         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 373         init_waitqueue_head(&gss_msg->waitqueue);
 374         atomic_set(&gss_msg->count, 1);
 375         gss_msg->msg.data = &gss_msg->uid;
 376         gss_msg->msg.len = sizeof(gss_msg->uid);
 377         gss_msg->uid = uid;
 378         gss_msg->auth = gss_auth;
 379         return gss_msg;
 380 }
 381
 382 static struct gss_upcall_msg *
 383 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
 384 {
 385         struct gss_cred *gss_cred = container_of(cred,
 386                         struct gss_cred, gc_base);
 387         struct gss_upcall_msg *gss_new, *gss_msg;
 388         uid_t uid = cred->cr_uid;
 389
 390         /* Special case: rpc.gssd assumes that uid == 0 implies machine creds */
 391         if (gss_cred->gc_machine_cred != 0)
 392                 uid = 0;
 393
 394         gss_new = gss_alloc_msg(gss_auth, uid);
 395         if (IS_ERR(gss_new))
 396                 return gss_new;
 397         gss_msg = gss_add_msg(gss_auth, gss_new);
 398         if (gss_msg == gss_new) {
 399                 struct inode *inode = &gss_new->inode->vfs_inode;
 400                 int res = rpc_queue_upcall(inode, &gss_new->msg);
 401                 if (res) {
 402                         gss_unhash_msg(gss_new);
 403                         gss_msg = ERR_PTR(res);
 404                 }
 405         } else
 406                 gss_release_msg(gss_new);
 407         return gss_msg;
 408 }
 409
 410 static void warn_gssd(void)
 411 {
 412         static unsigned long ratelimit;
 413         unsigned long now = jiffies;
 414
 415         if (time_after(now, ratelimit)) {
 416                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 417                                 "Please check user daemon is running.\n");
 418                 ratelimit = now + 15*HZ;
 419         }
 420 }
 421
 422 static inline int
 423 gss_refresh_upcall(struct rpc_task *task)
 424 {
 425         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 426         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 427                         struct gss_auth, rpc_auth);
 428         struct gss_cred *gss_cred = container_of(cred,
 429                         struct gss_cred, gc_base);
 430         struct gss_upcall_msg *gss_msg;
 431         struct inode *inode;
 432         int err = 0;
 433
 434         dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
 435                                                                 cred->cr_uid);
 436         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
 437         if (IS_ERR(gss_msg) == -EAGAIN) {
 438                 /* XXX: warning on the first, under the assumption we
 439                  * shouldn't normally hit this case on a refresh. */
 440                 warn_gssd();
 441                 task->tk_timeout = 15*HZ;
 442                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
 443                 return 0;
 444         }
 445         if (IS_ERR(gss_msg)) {
 446                 err = PTR_ERR(gss_msg);
 447                 goto out;
 448         }
 449         inode = &gss_msg->inode->vfs_inode;
 450         spin_lock(&inode->i_lock);
 451         if (gss_cred->gc_upcall != NULL)
 452                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 453         else if (gss_msg->ctx != NULL) {
 454                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
 455                 gss_cred->gc_upcall = NULL;
 456                 rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 457         } else if (gss_msg->msg.errno >= 0) {
 458                 task->tk_timeout = 0;
 459                 gss_cred->gc_upcall = gss_msg;
 460                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 461                 atomic_inc(&gss_msg->count);
 462                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 463         } else
 464                 err = gss_msg->msg.errno;
 465         spin_unlock(&inode->i_lock);
 466         gss_release_msg(gss_msg);
 467 out:
 468         dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
 469                         task->tk_pid, cred->cr_uid, err);
 470         return err;
 471 }
 472
 473 static inline int
 474 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 475 {
 476         struct inode *inode;
 477         struct rpc_cred *cred = &gss_cred->gc_base;
 478         struct gss_upcall_msg *gss_msg;
 479         DEFINE_WAIT(wait);
 480         int err = 0;
 481
 482         dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
 483 retry:
 484         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 485         if (PTR_ERR(gss_msg) == -EAGAIN) {
 486                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
 487                                 pipe_version >= 0, 15*HZ);
 488                 if (err)
 489                         goto out;
 490                 if (pipe_version < 0)
 491                         warn_gssd();
 492                 goto retry;
 493         }
 494         if (IS_ERR(gss_msg)) {
 495                 err = PTR_ERR(gss_msg);
 496                 goto out;
 497         }
 498         inode = &gss_msg->inode->vfs_inode;
 499         for (;;) {
 500                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
 501                 spin_lock(&inode->i_lock);
 502                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 503                         break;
 504                 }
 505                 spin_unlock(&inode->i_lock);
 506                 if (signalled()) {
 507                         err = -ERESTARTSYS;
 508                         goto out_intr;
 509                 }
 510                 schedule();
 511         }
 512         if (gss_msg->ctx)
 513                 gss_cred_set_ctx(cred, gss_msg->ctx);
 514         else
 515                 err = gss_msg->msg.errno;
 516         spin_unlock(&inode->i_lock);
 517 out_intr:
 518         finish_wait(&gss_msg->waitqueue, &wait);
 519         gss_release_msg(gss_msg);
 520 out:
 521         dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
 522                         cred->cr_uid, err);
 523         return err;
 524 }
 525
 526 static ssize_t
 527 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 528                 char __user *dst, size_t buflen)
 529 {
 530         char *data = (char *)msg->data + msg->copied;
 531         size_t mlen = min(msg->len, buflen);
 532         unsigned long left;
 533
 534         left = copy_to_user(dst, data, mlen);
 535         if (left == mlen) {
 536                 msg->errno = -EFAULT;
 537                 return -EFAULT;
 538         }
 539
 540         mlen -= left;
 541         msg->copied += mlen;
 542         msg->errno = 0;
 543         return mlen;
 544 }
 545
 546 #define MSG_BUF_MAXSIZE 1024
 547
 548 static ssize_t
 549 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 550 {
 551         const void *p, *end;
 552         void *buf;
 553         struct gss_upcall_msg *gss_msg;
 554         struct inode *inode = filp->f_path.dentry->d_inode;
 555         struct gss_cl_ctx *ctx;
 556         uid_t uid;
 557         ssize_t err = -EFBIG;
 558
 559         if (mlen > MSG_BUF_MAXSIZE)
 560                 goto out;
 561         err = -ENOMEM;
 562         buf = kmalloc(mlen, GFP_NOFS);
 563         if (!buf)
 564                 goto out;
 565
 566         err = -EFAULT;
 567         if (copy_from_user(buf, src, mlen))
 568                 goto err;
 569
 570         end = (const void *)((char *)buf + mlen);
 571         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
 572         if (IS_ERR(p)) {
 573                 err = PTR_ERR(p);
 574                 goto err;
 575         }
 576
 577         err = -ENOMEM;
 578         ctx = gss_alloc_context();
 579         if (ctx == NULL)
 580                 goto err;
 581
 582         err = -ENOENT;
 583         /* Find a matching upcall */
 584         spin_lock(&inode->i_lock);
 585         gss_msg = __gss_find_upcall(RPC_I(inode), uid);
 586         if (gss_msg == NULL) {
 587                 spin_unlock(&inode->i_lock);
 588                 goto err_put_ctx;
 589         }
 590         list_del_init(&gss_msg->list);
 591         spin_unlock(&inode->i_lock);
 592
 593         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 594         if (IS_ERR(p)) {
 595                 err = PTR_ERR(p);
 596                 gss_msg->msg.errno = (err == -EAGAIN) ? -EAGAIN : -EACCES;
 597                 goto err_release_msg;
 598         }
 599         gss_msg->ctx = gss_get_ctx(ctx);
 600         err = mlen;
 601
 602 err_release_msg:
 603         spin_lock(&inode->i_lock);
 604         __gss_unhash_msg(gss_msg);
 605         spin_unlock(&inode->i_lock);
 606         gss_release_msg(gss_msg);
 607 err_put_ctx:
 608         gss_put_ctx(ctx);
 609 err:
 610         kfree(buf);
 611 out:
 612         dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
 613         return err;
 614 }
 615
 616 static int
 617 gss_pipe_open(struct inode *inode)
 618 {
 619         spin_lock(&pipe_version_lock);
 620         if (pipe_version < 0) {
 621                 pipe_version = 0;
 622                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 623                 wake_up(&pipe_version_waitqueue);
 624         }
 625         atomic_inc(&pipe_users);
 626         spin_unlock(&pipe_version_lock);
 627         return 0;
 628 }
 629
 630 static void
 631 gss_pipe_release(struct inode *inode)
 632 {
 633         struct rpc_inode *rpci = RPC_I(inode);
 634         struct gss_upcall_msg *gss_msg;
 635
 636         spin_lock(&inode->i_lock);
 637         while (!list_empty(&rpci->in_downcall)) {
 638
 639                 gss_msg = list_entry(rpci->in_downcall.next,
 640                                 struct gss_upcall_msg, list);
 641                 gss_msg->msg.errno = -EPIPE;
 642                 atomic_inc(&gss_msg->count);
 643                 __gss_unhash_msg(gss_msg);
 644                 spin_unlock(&inode->i_lock);
 645                 gss_release_msg(gss_msg);
 646                 spin_lock(&inode->i_lock);
 647         }
 648         spin_unlock(&inode->i_lock);
 649
 650         put_pipe_version();
 651 }
 652
 653 static void
 654 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 655 {
 656         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 657
 658         if (msg->errno < 0) {
 659                 dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
 660                                 gss_msg);
 661                 atomic_inc(&gss_msg->count);
 662                 gss_unhash_msg(gss_msg);
 663                 if (msg->errno == -ETIMEDOUT)
 664                         warn_gssd();
 665                 gss_release_msg(gss_msg);
 666         }
 667 }
 668
 669 /*
 670  * NOTE: we have the opportunity to use different
 671  * parameters based on the input flavor (which must be a pseudoflavor)
 672  */
 673 static struct rpc_auth *
 674 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 675 {
 676         struct gss_auth *gss_auth;
 677         struct rpc_auth * auth;
 678         int err = -ENOMEM; /* XXX? */
 679
 680         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 681
 682         if (!try_module_get(THIS_MODULE))
 683                 return ERR_PTR(err);
 684         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 685                 goto out_dec;
 686         gss_auth->client = clnt;
 687         err = -EINVAL;
 688         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 689         if (!gss_auth->mech) {
 690                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
 691                                 __func__, flavor);
 692                 goto err_free;
 693         }
 694         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 695         if (gss_auth->service == 0)
 696                 goto err_put_mech;
 697         auth = &gss_auth->rpc_auth;
 698         auth->au_cslack = GSS_CRED_SLACK >> 2;
 699         auth->au_rslack = GSS_VERF_SLACK >> 2;
 700         auth->au_ops = &authgss_ops;
 701         auth->au_flavor = flavor;
 702         atomic_set(&auth->au_count, 1);
 703         kref_init(&gss_auth->kref);
 704
 705         gss_auth->dentry = rpc_mkpipe(clnt->cl_dentry, gss_auth->mech->gm_name,
 706                         clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 707         if (IS_ERR(gss_auth->dentry)) {
 708                 err = PTR_ERR(gss_auth->dentry);
 709                 goto err_put_mech;
 710         }
 711
 712         err = rpcauth_init_credcache(auth);
 713         if (err)
 714                 goto err_unlink_pipe;
 715
 716         return auth;
 717 err_unlink_pipe:
 718         rpc_unlink(gss_auth->dentry);
 719 err_put_mech:
 720         gss_mech_put(gss_auth->mech);
 721 err_free:
 722         kfree(gss_auth);
 723 out_dec:
 724         module_put(THIS_MODULE);
 725         return ERR_PTR(err);
 726 }
 727
 728 static void
 729 gss_free(struct gss_auth *gss_auth)
 730 {
 731         rpc_unlink(gss_auth->dentry);
 732         gss_mech_put(gss_auth->mech);
 733
 734         kfree(gss_auth);
 735         module_put(THIS_MODULE);
 736 }
 737
 738 static void
 739 gss_free_callback(struct kref *kref)
 740 {
 741         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
 742
 743         gss_free(gss_auth);
 744 }
 745
 746 static void
 747 gss_destroy(struct rpc_auth *auth)
 748 {
 749         struct gss_auth *gss_auth;
 750
 751         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
 752                         auth, auth->au_flavor);
 753
 754         rpcauth_destroy_credcache(auth);
 755
 756         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 757         kref_put(&gss_auth->kref, gss_free_callback);
 758 }
 759
 760 /*
 761  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
 762  * to the server with the GSS control procedure field set to
 763  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
 764  * all RPCSEC_GSS state associated with that context.
 765  */
 766 static int
 767 gss_destroying_context(struct rpc_cred *cred)
 768 {
 769         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 770         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 771         struct rpc_task *task;
 772
 773         if (gss_cred->gc_ctx == NULL ||
 774             test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 775                 return 0;
 776
 777         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
 778         cred->cr_ops = &gss_nullops;
 779
 780         /* Take a reference to ensure the cred will be destroyed either
 781          * by the RPC call or by the put_rpccred() below */
 782         get_rpccred(cred);
 783
 784         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
 785         if (!IS_ERR(task))
 786                 rpc_put_task(task);
 787
 788         put_rpccred(cred);
 789         return 1;
 790 }
 791
 792 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
 793  * to create a new cred or context, so they check that things have been
 794  * allocated before freeing them. */
 795 static void
 796 gss_do_free_ctx(struct gss_cl_ctx *ctx)
 797 {
 798         dprintk("RPC:       gss_free_ctx\n");
 799
 800         kfree(ctx->gc_wire_ctx.data);
 801         kfree(ctx);
 802 }
 803
 804 static void
 805 gss_free_ctx_callback(struct rcu_head *head)
 806 {
 807         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
 808         gss_do_free_ctx(ctx);
 809 }
 810
 811 static void
 812 gss_free_ctx(struct gss_cl_ctx *ctx)
 813 {
 814         struct gss_ctx *gc_gss_ctx;
 815
 816         gc_gss_ctx = rcu_dereference(ctx->gc_gss_ctx);
 817         rcu_assign_pointer(ctx->gc_gss_ctx, NULL);
 818         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
 819         if (gc_gss_ctx)
 820                 gss_delete_sec_context(&gc_gss_ctx);
 821 }
 822
 823 static void
 824 gss_free_cred(struct gss_cred *gss_cred)
 825 {
 826         dprintk("RPC:       gss_free_cred %p\n", gss_cred);
 827         kfree(gss_cred);
 828 }
 829
 830 static void
 831 gss_free_cred_callback(struct rcu_head *head)
 832 {
 833         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
 834         gss_free_cred(gss_cred);
 835 }
 836
 837 static void
 838 gss_destroy_nullcred(struct rpc_cred *cred)
 839 {
 840         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 841         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 842         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
 843
 844         rcu_assign_pointer(gss_cred->gc_ctx, NULL);
 845         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
 846         if (ctx)
 847                 gss_put_ctx(ctx);
 848         kref_put(&gss_auth->kref, gss_free_callback);
 849 }
 850
 851 static void
 852 gss_destroy_cred(struct rpc_cred *cred)
 853 {
 854
 855         if (gss_destroying_context(cred))
 856                 return;
 857         gss_destroy_nullcred(cred);
 858 }
 859
 860 /*
 861  * Lookup RPCSEC_GSS cred for the current process
 862  */
 863 static struct rpc_cred *
 864 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 865 {
 866         return rpcauth_lookup_credcache(auth, acred, flags);
 867 }
 868
 869 static struct rpc_cred *
 870 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 871 {
 872         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 873         struct gss_cred *cred = NULL;
 874         int err = -ENOMEM;
 875
 876         dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
 877                 acred->uid, auth->au_flavor);
 878
 879         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
 880                 goto out_err;
 881
 882         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
 883         /*
 884          * Note: in order to force a call to call_refresh(), we deliberately
 885          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
 886          */
 887         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
 888         cred->gc_service = gss_auth->service;
 889         cred->gc_machine_cred = acred->machine_cred;
 890         kref_get(&gss_auth->kref);
 891         return &cred->gc_base;
 892
 893 out_err:
 894         dprintk("RPC:       gss_create_cred failed with error %d\n", err);
 895         return ERR_PTR(err);
 896 }
 897
 898 static int
 899 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
 900 {
 901         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 902         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
 903         int err;
 904
 905         do {
 906                 err = gss_create_upcall(gss_auth, gss_cred);
 907         } while (err == -EAGAIN);
 908         return err;
 909 }
 910
 911 static int
 912 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
 913 {
 914         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
 915
 916         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
 917                 goto out;
 918         /* Don't match with creds that have expired. */
 919         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
 920                 return 0;
 921         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
 922                 return 0;
 923 out:
 924         if (acred->machine_cred != gss_cred->gc_machine_cred)
 925                 return 0;
 926         return (rc->cr_uid == acred->uid);
 927 }
 928
 929 /*
 930 * Marshal credentials.
 931 * Maybe we should keep a cached credential for performance reasons.
 932 */
 933 static __be32 *
 934 gss_marshal(struct rpc_task *task, __be32 *p)
 935 {
 936         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 937         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
 938                                                  gc_base);
 939         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
 940         __be32          *cred_len;
 941         struct rpc_rqst *req = task->tk_rqstp;
 942         u32             maj_stat = 0;
 943         struct xdr_netobj mic;
 944         struct kvec     iov;
 945         struct xdr_buf  verf_buf;
 946
 947         dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
 948
 949         *p++ = htonl(RPC_AUTH_GSS);
 950         cred_len = p++;
 951
 952         spin_lock(&ctx->gc_seq_lock);
 953         req->rq_seqno = ctx->gc_seq++;
 954         spin_unlock(&ctx->gc_seq_lock);
 955
 956         *p++ = htonl((u32) RPC_GSS_VERSION);
 957         *p++ = htonl((u32) ctx->gc_proc);
 958         *p++ = htonl((u32) req->rq_seqno);
 959         *p++ = htonl((u32) gss_cred->gc_service);
 960         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
 961         *cred_len = htonl((p - (cred_len + 1)) << 2);
 962
 963         /* We compute the checksum for the verifier over the xdr-encoded bytes
 964          * starting with the xid and ending at the end of the credential: */
 965         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
 966                                         req->rq_snd_buf.head[0].iov_base);
 967         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
 968         xdr_buf_from_iov(&iov, &verf_buf);
 969
 970         /* set verifier flavor*/
 971         *p++ = htonl(RPC_AUTH_GSS);
 972
 973         mic.data = (u8 *)(p + 1);
 974         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 975         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
 976                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 977         } else if (maj_stat != 0) {
 978                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
 979                 goto out_put_ctx;
 980         }
 981         p = xdr_encode_opaque(p, NULL, mic.len);
 982         gss_put_ctx(ctx);
 983         return p;
 984 out_put_ctx:
 985         gss_put_ctx(ctx);
 986         return NULL;
 987 }
 988
 989 static int gss_renew_cred(struct rpc_task *task)
 990 {
 991         struct rpc_cred *oldcred = task->tk_msg.rpc_cred;
 992         struct gss_cred *gss_cred = container_of(oldcred,
 993                                                  struct gss_cred,
 994                                                  gc_base);
 995         struct rpc_auth *auth = oldcred->cr_auth;
 996         struct auth_cred acred = {
 997                 .uid = oldcred->cr_uid,
 998                 .machine_cred = gss_cred->gc_machine_cred,
 999         };
1000         struct rpc_cred *new;
1001
1002         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1003         if (IS_ERR(new))
1004                 return PTR_ERR(new);
1005         task->tk_msg.rpc_cred = new;
1006         put_rpccred(oldcred);
1007         return 0;
1008 }
1009
1010 /*
1011 * Refresh credentials. XXX - finish
1012 */
1013 static int
1014 gss_refresh(struct rpc_task *task)
1015 {
1016         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1017         int ret = 0;
1018
1019         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1020                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1021                 ret = gss_renew_cred(task);
1022                 if (ret < 0)
1023                         goto out;
1024                 cred = task->tk_msg.rpc_cred;
1025         }
1026
1027         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1028                 ret = gss_refresh_upcall(task);
1029 out:
1030         return ret;
1031 }
1032
1033 /* Dummy refresh routine: used only when destroying the context */
1034 static int
1035 gss_refresh_null(struct rpc_task *task)
1036 {
1037         return -EACCES;
1038 }
1039
1040 static __be32 *
1041 gss_validate(struct rpc_task *task, __be32 *p)
1042 {
1043         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1044         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1045         __be32          seq;
1046         struct kvec     iov;
1047         struct xdr_buf  verf_buf;
1048         struct xdr_netobj mic;
1049         u32             flav,len;
1050         u32             maj_stat;
1051
1052         dprintk("RPC: %5u gss_validate\n", task->tk_pid);
1053
1054         flav = ntohl(*p++);
1055         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1056                 goto out_bad;
1057         if (flav != RPC_AUTH_GSS)
1058                 goto out_bad;
1059         seq = htonl(task->tk_rqstp->rq_seqno);
1060         iov.iov_base = &seq;
1061         iov.iov_len = sizeof(seq);
1062         xdr_buf_from_iov(&iov, &verf_buf);
1063         mic.data = (u8 *)p;
1064         mic.len = len;
1065
1066         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1067         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1068                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1069         if (maj_stat) {
1070                 dprintk("RPC: %5u gss_validate: gss_verify_mic returned "
1071                                 "error 0x%08x\n", task->tk_pid, maj_stat);
1072                 goto out_bad;
1073         }
1074         /* We leave it to unwrap to calculate au_rslack. For now we just
1075          * calculate the length of the verifier: */
1076         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1077         gss_put_ctx(ctx);
1078         dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
1079                         task->tk_pid);
1080         return p + XDR_QUADLEN(len);
1081 out_bad:
1082         gss_put_ctx(ctx);
1083         dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
1084         return NULL;
1085 }
1086
1087 static inline int
1088 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1089                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1090 {
1091         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1092         struct xdr_buf  integ_buf;
1093         __be32          *integ_len = NULL;
1094         struct xdr_netobj mic;
1095         u32             offset;
1096         __be32          *q;
1097         struct kvec     *iov;
1098         u32             maj_stat = 0;
1099         int             status = -EIO;
1100
1101         integ_len = p++;
1102         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1103         *p++ = htonl(rqstp->rq_seqno);
1104
1105         status = encode(rqstp, p, obj);
1106         if (status)
1107                 return status;
1108
1109         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1110                                 offset, snd_buf->len - offset))
1111                 return status;
1112         *integ_len = htonl(integ_buf.len);
1113
1114         /* guess whether we're in the head or the tail: */
1115         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1116                 iov = snd_buf->tail;
1117         else
1118                 iov = snd_buf->head;
1119         p = iov->iov_base + iov->iov_len;
1120         mic.data = (u8 *)(p + 1);
1121
1122         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1123         status = -EIO; /* XXX? */
1124         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1125                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1126         else if (maj_stat)
1127                 return status;
1128         q = xdr_encode_opaque(p, NULL, mic.len);
1129
1130         offset = (u8 *)q - (u8 *)p;
1131         iov->iov_len += offset;
1132         snd_buf->len += offset;
1133         return 0;
1134 }
1135
1136 static void
1137 priv_release_snd_buf(struct rpc_rqst *rqstp)
1138 {
1139         int i;
1140
1141         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1142                 __free_page(rqstp->rq_enc_pages[i]);
1143         kfree(rqstp->rq_enc_pages);
1144 }
1145
1146 static int
1147 alloc_enc_pages(struct rpc_rqst *rqstp)
1148 {
1149         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1150         int first, last, i;
1151
1152         if (snd_buf->page_len == 0) {
1153                 rqstp->rq_enc_pages_num = 0;
1154                 return 0;
1155         }
1156
1157         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1158         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1159         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1160         rqstp->rq_enc_pages
1161                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1162                                 GFP_NOFS);
1163         if (!rqstp->rq_enc_pages)
1164                 goto out;
1165         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1166                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1167                 if (rqstp->rq_enc_pages[i] == NULL)
1168                         goto out_free;
1169         }
1170         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1171         return 0;
1172 out_free:
1173         for (i--; i >= 0; i--) {
1174                 __free_page(rqstp->rq_enc_pages[i]);
1175         }
1176 out:
1177         return -EAGAIN;
1178 }
1179
1180 static inline int
1181 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1182                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1183 {
1184         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1185         u32             offset;
1186         u32             maj_stat;
1187         int             status;
1188         __be32          *opaque_len;
1189         struct page     **inpages;
1190         int             first;
1191         int             pad;
1192         struct kvec     *iov;
1193         char            *tmp;
1194
1195         opaque_len = p++;
1196         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1197         *p++ = htonl(rqstp->rq_seqno);
1198
1199         status = encode(rqstp, p, obj);
1200         if (status)
1201                 return status;
1202
1203         status = alloc_enc_pages(rqstp);
1204         if (status)
1205                 return status;
1206         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1207         inpages = snd_buf->pages + first;
1208         snd_buf->pages = rqstp->rq_enc_pages;
1209         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1210         /* Give the tail its own page, in case we need extra space in the
1211          * head when wrapping: */
1212         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1213                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1214                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1215                 snd_buf->tail[0].iov_base = tmp;
1216         }
1217         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1218         /* RPC_SLACK_SPACE should prevent this ever happening: */
1219         BUG_ON(snd_buf->len > snd_buf->buflen);
1220         status = -EIO;
1221         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1222          * done anyway, so it's safe to put the request on the wire: */
1223         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1224                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1225         else if (maj_stat)
1226                 return status;
1227
1228         *opaque_len = htonl(snd_buf->len - offset);
1229         /* guess whether we're in the head or the tail: */
1230         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1231                 iov = snd_buf->tail;
1232         else
1233                 iov = snd_buf->head;
1234         p = iov->iov_base + iov->iov_len;
1235         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1236         memset(p, 0, pad);
1237         iov->iov_len += pad;
1238         snd_buf->len += pad;
1239
1240         return 0;
1241 }
1242
1243 static int
1244 gss_wrap_req(struct rpc_task *task,
1245              kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
1246 {
1247         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1248         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1249                         gc_base);
1250         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1251         int             status = -EIO;
1252
1253         dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
1254         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1255                 /* The spec seems a little ambiguous here, but I think that not
1256                  * wrapping context destruction requests makes the most sense.
1257                  */
1258                 status = encode(rqstp, p, obj);
1259                 goto out;
1260         }
1261         switch (gss_cred->gc_service) {
1262                 case RPC_GSS_SVC_NONE:
1263                         status = encode(rqstp, p, obj);
1264                         break;
1265                 case RPC_GSS_SVC_INTEGRITY:
1266                         status = gss_wrap_req_integ(cred, ctx, encode,
1267                                                                 rqstp, p, obj);
1268                         break;
1269                 case RPC_GSS_SVC_PRIVACY:
1270                         status = gss_wrap_req_priv(cred, ctx, encode,
1271                                         rqstp, p, obj);
1272                         break;
1273         }
1274 out:
1275         gss_put_ctx(ctx);
1276         dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
1277         return status;
1278 }
1279
1280 static inline int
1281 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1282                 struct rpc_rqst *rqstp, __be32 **p)
1283 {
1284         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1285         struct xdr_buf integ_buf;
1286         struct xdr_netobj mic;
1287         u32 data_offset, mic_offset;
1288         u32 integ_len;
1289         u32 maj_stat;
1290         int status = -EIO;
1291
1292         integ_len = ntohl(*(*p)++);
1293         if (integ_len & 3)
1294                 return status;
1295         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1296         mic_offset = integ_len + data_offset;
1297         if (mic_offset > rcv_buf->len)
1298                 return status;
1299         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1300                 return status;
1301
1302         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1303                                 mic_offset - data_offset))
1304                 return status;
1305
1306         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1307                 return status;
1308
1309         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1310         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1311                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1312         if (maj_stat != GSS_S_COMPLETE)
1313                 return status;
1314         return 0;
1315 }
1316
1317 static inline int
1318 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1319                 struct rpc_rqst *rqstp, __be32 **p)
1320 {
1321         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1322         u32 offset;
1323         u32 opaque_len;
1324         u32 maj_stat;
1325         int status = -EIO;
1326
1327         opaque_len = ntohl(*(*p)++);
1328         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1329         if (offset + opaque_len > rcv_buf->len)
1330                 return status;
1331         /* remove padding: */
1332         rcv_buf->len = offset + opaque_len;
1333
1334         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1335         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1336                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1337         if (maj_stat != GSS_S_COMPLETE)
1338                 return status;
1339         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1340                 return status;
1341
1342         return 0;
1343 }
1344
1345
1346 static int
1347 gss_unwrap_resp(struct rpc_task *task,
1348                 kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
1349 {
1350         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1351         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1352                         gc_base);
1353         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1354         __be32          *savedp = p;
1355         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1356         int             savedlen = head->iov_len;
1357         int             status = -EIO;
1358
1359         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1360                 goto out_decode;
1361         switch (gss_cred->gc_service) {
1362                 case RPC_GSS_SVC_NONE:
1363                         break;
1364                 case RPC_GSS_SVC_INTEGRITY:
1365                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1366                         if (status)
1367                                 goto out;
1368                         break;
1369                 case RPC_GSS_SVC_PRIVACY:
1370                         status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1371                         if (status)
1372                                 goto out;
1373                         break;
1374         }
1375         /* take into account extra slack for integrity and privacy cases: */
1376         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1377                                                 + (savedlen - head->iov_len);
1378 out_decode:
1379         status = decode(rqstp, p, obj);
1380 out:
1381         gss_put_ctx(ctx);
1382         dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
1383                         status);
1384         return status;
1385 }
1386
1387 static const struct rpc_authops authgss_ops = {
1388         .owner          = THIS_MODULE,
1389         .au_flavor      = RPC_AUTH_GSS,
1390         .au_name        = "RPCSEC_GSS",
1391         .create         = gss_create,
1392         .destroy        = gss_destroy,
1393         .lookup_cred    = gss_lookup_cred,
1394         .crcreate       = gss_create_cred
1395 };
1396
1397 static const struct rpc_credops gss_credops = {
1398         .cr_name        = "AUTH_GSS",
1399         .crdestroy      = gss_destroy_cred,
1400         .cr_init        = gss_cred_init,
1401         .crbind         = rpcauth_generic_bind_cred,
1402         .crmatch        = gss_match,
1403         .crmarshal      = gss_marshal,
1404         .crrefresh      = gss_refresh,
1405         .crvalidate     = gss_validate,
1406         .crwrap_req     = gss_wrap_req,
1407         .crunwrap_resp  = gss_unwrap_resp,
1408 };
1409
1410 static const struct rpc_credops gss_nullops = {
1411         .cr_name        = "AUTH_GSS",
1412         .crdestroy      = gss_destroy_nullcred,
1413         .crbind         = rpcauth_generic_bind_cred,
1414         .crmatch        = gss_match,
1415         .crmarshal      = gss_marshal,
1416         .crrefresh      = gss_refresh_null,
1417         .crvalidate     = gss_validate,
1418         .crwrap_req     = gss_wrap_req,
1419         .crunwrap_resp  = gss_unwrap_resp,
1420 };
1421
1422 static struct rpc_pipe_ops gss_upcall_ops = {
1423         .upcall         = gss_pipe_upcall,
1424         .downcall       = gss_pipe_downcall,
1425         .destroy_msg    = gss_pipe_destroy_msg,
1426         .open_pipe      = gss_pipe_open,
1427         .release_pipe   = gss_pipe_release,
1428 };
1429
1430 /*
1431  * Initialize RPCSEC_GSS module
1432  */
1433 static int __init init_rpcsec_gss(void)
1434 {
1435         int err = 0;
1436
1437         err = rpcauth_register(&authgss_ops);
1438         if (err)
1439                 goto out;
1440         err = gss_svc_init();
1441         if (err)
1442                 goto out_unregister;
1443         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
1444         return 0;
1445 out_unregister:
1446         rpcauth_unregister(&authgss_ops);
1447 out:
1448         return err;
1449 }
1450
1451 static void __exit exit_rpcsec_gss(void)
1452 {
1453         gss_svc_shutdown();
1454         rpcauth_unregister(&authgss_ops);
1455 }
1456
1457 MODULE_LICENSE("GPL");
1458 module_init(init_rpcsec_gss)
1459 module_exit(exit_rpcsec_gss)