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 <linux/uaccess.h>
  54 #include <linux/hashtable.h>
  55
  56 #include "auth_gss_internal.h"
  57 #include "../netns.h"
  58
  59 static const struct rpc_authops authgss_ops;
  60
  61 static const struct rpc_credops gss_credops;
  62 static const struct rpc_credops gss_nullops;
  63
  64 #define GSS_RETRY_EXPIRED 5
  65 static unsigned int gss_expired_cred_retry_delay = GSS_RETRY_EXPIRED;
  66
  67 #define GSS_KEY_EXPIRE_TIMEO 240
  68 static unsigned int gss_key_expire_timeo = GSS_KEY_EXPIRE_TIMEO;
  69
  70 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  71 # define RPCDBG_FACILITY        RPCDBG_AUTH
  72 #endif
  73
  74 #define GSS_CRED_SLACK          (RPC_MAX_AUTH_SIZE * 2)
  75 /* length of a krb5 verifier (48), plus data added before arguments when
  76  * using integrity (two 4-byte integers): */
  77 #define GSS_VERF_SLACK          100
  78
  79 static DEFINE_HASHTABLE(gss_auth_hash_table, 4);
  80 static DEFINE_SPINLOCK(gss_auth_hash_lock);
  81
  82 struct gss_pipe {
  83         struct rpc_pipe_dir_object pdo;
  84         struct rpc_pipe *pipe;
  85         struct rpc_clnt *clnt;
  86         const char *name;
  87         struct kref kref;
  88 };
  89
  90 struct gss_auth {
  91         struct kref kref;
  92         struct hlist_node hash;
  93         struct rpc_auth rpc_auth;
  94         struct gss_api_mech *mech;
  95         enum rpc_gss_svc service;
  96         struct rpc_clnt *client;
  97         struct net *net;
  98         /*
  99          * There are two upcall pipes; dentry[1], named "gssd", is used
 100          * for the new text-based upcall; dentry[0] is named after the
 101          * mechanism (for example, "krb5") and exists for
 102          * backwards-compatibility with older gssd's.
 103          */
 104         struct gss_pipe *gss_pipe[2];
 105         const char *target_name;
 106 };
 107
 108 /* pipe_version >= 0 if and only if someone has a pipe open. */
 109 static DEFINE_SPINLOCK(pipe_version_lock);
 110 static struct rpc_wait_queue pipe_version_rpc_waitqueue;
 111 static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
 112 static void gss_put_auth(struct gss_auth *gss_auth);
 113
 114 static void gss_free_ctx(struct gss_cl_ctx *);
 115 static const struct rpc_pipe_ops gss_upcall_ops_v0;
 116 static const struct rpc_pipe_ops gss_upcall_ops_v1;
 117
 118 static inline struct gss_cl_ctx *
 119 gss_get_ctx(struct gss_cl_ctx *ctx)
 120 {
 121         refcount_inc(&ctx->count);
 122         return ctx;
 123 }
 124
 125 static inline void
 126 gss_put_ctx(struct gss_cl_ctx *ctx)
 127 {
 128         if (refcount_dec_and_test(&ctx->count))
 129                 gss_free_ctx(ctx);
 130 }
 131
 132 /* gss_cred_set_ctx:
 133  * called by gss_upcall_callback and gss_create_upcall in order
 134  * to set the gss context. The actual exchange of an old context
 135  * and a new one is protected by the pipe->lock.
 136  */
 137 static void
 138 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 139 {
 140         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 141
 142         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 143                 return;
 144         gss_get_ctx(ctx);
 145         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 146         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 147         smp_mb__before_atomic();
 148         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 149 }
 150
 151 static struct gss_cl_ctx *
 152 gss_cred_get_ctx(struct rpc_cred *cred)
 153 {
 154         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 155         struct gss_cl_ctx *ctx = NULL;
 156
 157         rcu_read_lock();
 158         ctx = rcu_dereference(gss_cred->gc_ctx);
 159         if (ctx)
 160                 gss_get_ctx(ctx);
 161         rcu_read_unlock();
 162         return ctx;
 163 }
 164
 165 static struct gss_cl_ctx *
 166 gss_alloc_context(void)
 167 {
 168         struct gss_cl_ctx *ctx;
 169
 170         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
 171         if (ctx != NULL) {
 172                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 173                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 174                 spin_lock_init(&ctx->gc_seq_lock);
 175                 refcount_set(&ctx->count,1);
 176         }
 177         return ctx;
 178 }
 179
 180 #define GSSD_MIN_TIMEOUT (60 * 60)
 181 static const void *
 182 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 183 {
 184         const void *q;
 185         unsigned int seclen;
 186         unsigned int timeout;
 187         unsigned long now = jiffies;
 188         u32 window_size;
 189         int ret;
 190
 191         /* First unsigned int gives the remaining lifetime in seconds of the
 192          * credential - e.g. the remaining TGT lifetime for Kerberos or
 193          * the -t value passed to GSSD.
 194          */
 195         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 196         if (IS_ERR(p))
 197                 goto err;
 198         if (timeout == 0)
 199                 timeout = GSSD_MIN_TIMEOUT;
 200         ctx->gc_expiry = now + ((unsigned long)timeout * HZ);
 201         /* Sequence number window. Determines the maximum number of
 202          * simultaneous requests
 203          */
 204         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 205         if (IS_ERR(p))
 206                 goto err;
 207         ctx->gc_win = window_size;
 208         /* gssd signals an error by passing ctx->gc_win = 0: */
 209         if (ctx->gc_win == 0) {
 210                 /*
 211                  * in which case, p points to an error code. Anything other
 212                  * than -EKEYEXPIRED gets converted to -EACCES.
 213                  */
 214                 p = simple_get_bytes(p, end, &ret, sizeof(ret));
 215                 if (!IS_ERR(p))
 216                         p = (ret == -EKEYEXPIRED) ? ERR_PTR(-EKEYEXPIRED) :
 217                                                     ERR_PTR(-EACCES);
 218                 goto err;
 219         }
 220         /* copy the opaque wire context */
 221         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 222         if (IS_ERR(p))
 223                 goto err;
 224         /* import the opaque security context */
 225         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 226         if (IS_ERR(p))
 227                 goto err;
 228         q = (const void *)((const char *)p + seclen);
 229         if (unlikely(q > end || q < p)) {
 230                 p = ERR_PTR(-EFAULT);
 231                 goto err;
 232         }
 233         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, NULL, GFP_NOFS);
 234         if (ret < 0) {
 235                 p = ERR_PTR(ret);
 236                 goto err;
 237         }
 238
 239         /* is there any trailing data? */
 240         if (q == end) {
 241                 p = q;
 242                 goto done;
 243         }
 244
 245         /* pull in acceptor name (if there is one) */
 246         p = simple_get_netobj(q, end, &ctx->gc_acceptor);
 247         if (IS_ERR(p))
 248                 goto err;
 249 done:
 250         dprintk("RPC:       %s Success. gc_expiry %lu now %lu timeout %u acceptor %.*s\n",
 251                 __func__, ctx->gc_expiry, now, timeout, ctx->gc_acceptor.len,
 252                 ctx->gc_acceptor.data);
 253         return p;
 254 err:
 255         dprintk("RPC:       %s returns error %ld\n", __func__, -PTR_ERR(p));
 256         return p;
 257 }
 258
 259 /* XXX: Need some documentation about why UPCALL_BUF_LEN is so small.
 260  *      Is user space expecting no more than UPCALL_BUF_LEN bytes?
 261  *      Note that there are now _two_ NI_MAXHOST sized data items
 262  *      being passed in this string.
 263  */
 264 #define UPCALL_BUF_LEN  256
 265
 266 struct gss_upcall_msg {
 267         refcount_t count;
 268         kuid_t  uid;
 269         struct rpc_pipe_msg msg;
 270         struct list_head list;
 271         struct gss_auth *auth;
 272         struct rpc_pipe *pipe;
 273         struct rpc_wait_queue rpc_waitqueue;
 274         wait_queue_head_t waitqueue;
 275         struct gss_cl_ctx *ctx;
 276         char databuf[UPCALL_BUF_LEN];
 277 };
 278
 279 static int get_pipe_version(struct net *net)
 280 {
 281         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 282         int ret;
 283
 284         spin_lock(&pipe_version_lock);
 285         if (sn->pipe_version >= 0) {
 286                 atomic_inc(&sn->pipe_users);
 287                 ret = sn->pipe_version;
 288         } else
 289                 ret = -EAGAIN;
 290         spin_unlock(&pipe_version_lock);
 291         return ret;
 292 }
 293
 294 static void put_pipe_version(struct net *net)
 295 {
 296         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 297
 298         if (atomic_dec_and_lock(&sn->pipe_users, &pipe_version_lock)) {
 299                 sn->pipe_version = -1;
 300                 spin_unlock(&pipe_version_lock);
 301         }
 302 }
 303
 304 static void
 305 gss_release_msg(struct gss_upcall_msg *gss_msg)
 306 {
 307         struct net *net = gss_msg->auth->net;
 308         if (!refcount_dec_and_test(&gss_msg->count))
 309                 return;
 310         put_pipe_version(net);
 311         BUG_ON(!list_empty(&gss_msg->list));
 312         if (gss_msg->ctx != NULL)
 313                 gss_put_ctx(gss_msg->ctx);
 314         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 315         gss_put_auth(gss_msg->auth);
 316         kfree(gss_msg);
 317 }
 318
 319 static struct gss_upcall_msg *
 320 __gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid, const struct gss_auth *auth)
 321 {
 322         struct gss_upcall_msg *pos;
 323         list_for_each_entry(pos, &pipe->in_downcall, list) {
 324                 if (!uid_eq(pos->uid, uid))
 325                         continue;
 326                 if (pos->auth->service != auth->service)
 327                         continue;
 328                 refcount_inc(&pos->count);
 329                 dprintk("RPC:       %s found msg %p\n", __func__, pos);
 330                 return pos;
 331         }
 332         dprintk("RPC:       %s found nothing\n", __func__);
 333         return NULL;
 334 }
 335
 336 /* Try to add an upcall to the pipefs queue.
 337  * If an upcall owned by our uid already exists, then we return a reference
 338  * to that upcall instead of adding the new upcall.
 339  */
 340 static inline struct gss_upcall_msg *
 341 gss_add_msg(struct gss_upcall_msg *gss_msg)
 342 {
 343         struct rpc_pipe *pipe = gss_msg->pipe;
 344         struct gss_upcall_msg *old;
 345
 346         spin_lock(&pipe->lock);
 347         old = __gss_find_upcall(pipe, gss_msg->uid, gss_msg->auth);
 348         if (old == NULL) {
 349                 refcount_inc(&gss_msg->count);
 350                 list_add(&gss_msg->list, &pipe->in_downcall);
 351         } else
 352                 gss_msg = old;
 353         spin_unlock(&pipe->lock);
 354         return gss_msg;
 355 }
 356
 357 static void
 358 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 359 {
 360         list_del_init(&gss_msg->list);
 361         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 362         wake_up_all(&gss_msg->waitqueue);
 363         refcount_dec(&gss_msg->count);
 364 }
 365
 366 static void
 367 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 368 {
 369         struct rpc_pipe *pipe = gss_msg->pipe;
 370
 371         if (list_empty(&gss_msg->list))
 372                 return;
 373         spin_lock(&pipe->lock);
 374         if (!list_empty(&gss_msg->list))
 375                 __gss_unhash_msg(gss_msg);
 376         spin_unlock(&pipe->lock);
 377 }
 378
 379 static void
 380 gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
 381 {
 382         switch (gss_msg->msg.errno) {
 383         case 0:
 384                 if (gss_msg->ctx == NULL)
 385                         break;
 386                 clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 387                 gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
 388                 break;
 389         case -EKEYEXPIRED:
 390                 set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 391         }
 392         gss_cred->gc_upcall_timestamp = jiffies;
 393         gss_cred->gc_upcall = NULL;
 394         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 395 }
 396
 397 static void
 398 gss_upcall_callback(struct rpc_task *task)
 399 {
 400         struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
 401                         struct gss_cred, gc_base);
 402         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 403         struct rpc_pipe *pipe = gss_msg->pipe;
 404
 405         spin_lock(&pipe->lock);
 406         gss_handle_downcall_result(gss_cred, gss_msg);
 407         spin_unlock(&pipe->lock);
 408         task->tk_status = gss_msg->msg.errno;
 409         gss_release_msg(gss_msg);
 410 }
 411
 412 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
 413 {
 414         uid_t uid = from_kuid(&init_user_ns, gss_msg->uid);
 415         memcpy(gss_msg->databuf, &uid, sizeof(uid));
 416         gss_msg->msg.data = gss_msg->databuf;
 417         gss_msg->msg.len = sizeof(uid);
 418
 419         BUILD_BUG_ON(sizeof(uid) > sizeof(gss_msg->databuf));
 420 }
 421
 422 static int gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
 423                                 const char *service_name,
 424                                 const char *target_name)
 425 {
 426         struct gss_api_mech *mech = gss_msg->auth->mech;
 427         char *p = gss_msg->databuf;
 428         size_t buflen = sizeof(gss_msg->databuf);
 429         int len;
 430
 431         len = scnprintf(p, buflen, "mech=%s uid=%d ", mech->gm_name,
 432                         from_kuid(&init_user_ns, gss_msg->uid));
 433         buflen -= len;
 434         p += len;
 435         gss_msg->msg.len = len;
 436
 437         /*
 438          * target= is a full service principal that names the remote
 439          * identity that we are authenticating to.
 440          */
 441         if (target_name) {
 442                 len = scnprintf(p, buflen, "target=%s ", target_name);
 443                 buflen -= len;
 444                 p += len;
 445                 gss_msg->msg.len += len;
 446         }
 447
 448         /*
 449          * gssd uses service= and srchost= to select a matching key from
 450          * the system's keytab to use as the source principal.
 451          *
 452          * service= is the service name part of the source principal,
 453          * or "*" (meaning choose any).
 454          *
 455          * srchost= is the hostname part of the source principal. When
 456          * not provided, gssd uses the local hostname.
 457          */
 458         if (service_name) {
 459                 char *c = strchr(service_name, '@');
 460
 461                 if (!c)
 462                         len = scnprintf(p, buflen, "service=%s ",
 463                                         service_name);
 464                 else
 465                         len = scnprintf(p, buflen,
 466                                         "service=%.*s srchost=%s ",
 467                                         (int)(c - service_name),
 468                                         service_name, c + 1);
 469                 buflen -= len;
 470                 p += len;
 471                 gss_msg->msg.len += len;
 472         }
 473
 474         if (mech->gm_upcall_enctypes) {
 475                 len = scnprintf(p, buflen, "enctypes=%s ",
 476                                 mech->gm_upcall_enctypes);
 477                 buflen -= len;
 478                 p += len;
 479                 gss_msg->msg.len += len;
 480         }
 481         len = scnprintf(p, buflen, "\n");
 482         if (len == 0)
 483                 goto out_overflow;
 484         gss_msg->msg.len += len;
 485
 486         gss_msg->msg.data = gss_msg->databuf;
 487         return 0;
 488 out_overflow:
 489         WARN_ON_ONCE(1);
 490         return -ENOMEM;
 491 }
 492
 493 static struct gss_upcall_msg *
 494 gss_alloc_msg(struct gss_auth *gss_auth,
 495                 kuid_t uid, const char *service_name)
 496 {
 497         struct gss_upcall_msg *gss_msg;
 498         int vers;
 499         int err = -ENOMEM;
 500
 501         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 502         if (gss_msg == NULL)
 503                 goto err;
 504         vers = get_pipe_version(gss_auth->net);
 505         err = vers;
 506         if (err < 0)
 507                 goto err_free_msg;
 508         gss_msg->pipe = gss_auth->gss_pipe[vers]->pipe;
 509         INIT_LIST_HEAD(&gss_msg->list);
 510         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 511         init_waitqueue_head(&gss_msg->waitqueue);
 512         refcount_set(&gss_msg->count, 1);
 513         gss_msg->uid = uid;
 514         gss_msg->auth = gss_auth;
 515         switch (vers) {
 516         case 0:
 517                 gss_encode_v0_msg(gss_msg);
 518                 break;
 519         default:
 520                 err = gss_encode_v1_msg(gss_msg, service_name, gss_auth->target_name);
 521                 if (err)
 522                         goto err_put_pipe_version;
 523         }
 524         kref_get(&gss_auth->kref);
 525         return gss_msg;
 526 err_put_pipe_version:
 527         put_pipe_version(gss_auth->net);
 528 err_free_msg:
 529         kfree(gss_msg);
 530 err:
 531         return ERR_PTR(err);
 532 }
 533
 534 static struct gss_upcall_msg *
 535 gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred)
 536 {
 537         struct gss_cred *gss_cred = container_of(cred,
 538                         struct gss_cred, gc_base);
 539         struct gss_upcall_msg *gss_new, *gss_msg;
 540         kuid_t uid = cred->cr_uid;
 541
 542         gss_new = gss_alloc_msg(gss_auth, uid, gss_cred->gc_principal);
 543         if (IS_ERR(gss_new))
 544                 return gss_new;
 545         gss_msg = gss_add_msg(gss_new);
 546         if (gss_msg == gss_new) {
 547                 int res;
 548                 refcount_inc(&gss_msg->count);
 549                 res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
 550                 if (res) {
 551                         gss_unhash_msg(gss_new);
 552                         refcount_dec(&gss_msg->count);
 553                         gss_release_msg(gss_new);
 554                         gss_msg = ERR_PTR(res);
 555                 }
 556         } else
 557                 gss_release_msg(gss_new);
 558         return gss_msg;
 559 }
 560
 561 static void warn_gssd(void)
 562 {
 563         dprintk("AUTH_GSS upcall failed. Please check user daemon is running.\n");
 564 }
 565
 566 static inline int
 567 gss_refresh_upcall(struct rpc_task *task)
 568 {
 569         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 570         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 571                         struct gss_auth, rpc_auth);
 572         struct gss_cred *gss_cred = container_of(cred,
 573                         struct gss_cred, gc_base);
 574         struct gss_upcall_msg *gss_msg;
 575         struct rpc_pipe *pipe;
 576         int err = 0;
 577
 578         dprintk("RPC: %5u %s for uid %u\n",
 579                 task->tk_pid, __func__, from_kuid(&init_user_ns, cred->cr_uid));
 580         gss_msg = gss_setup_upcall(gss_auth, cred);
 581         if (PTR_ERR(gss_msg) == -EAGAIN) {
 582                 /* XXX: warning on the first, under the assumption we
 583                  * shouldn't normally hit this case on a refresh. */
 584                 warn_gssd();
 585                 task->tk_timeout = 15*HZ;
 586                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
 587                 return -EAGAIN;
 588         }
 589         if (IS_ERR(gss_msg)) {
 590                 err = PTR_ERR(gss_msg);
 591                 goto out;
 592         }
 593         pipe = gss_msg->pipe;
 594         spin_lock(&pipe->lock);
 595         if (gss_cred->gc_upcall != NULL)
 596                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 597         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 598                 task->tk_timeout = 0;
 599                 gss_cred->gc_upcall = gss_msg;
 600                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 601                 refcount_inc(&gss_msg->count);
 602                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 603         } else {
 604                 gss_handle_downcall_result(gss_cred, gss_msg);
 605                 err = gss_msg->msg.errno;
 606         }
 607         spin_unlock(&pipe->lock);
 608         gss_release_msg(gss_msg);
 609 out:
 610         dprintk("RPC: %5u %s for uid %u result %d\n",
 611                 task->tk_pid, __func__,
 612                 from_kuid(&init_user_ns, cred->cr_uid), err);
 613         return err;
 614 }
 615
 616 static inline int
 617 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 618 {
 619         struct net *net = gss_auth->net;
 620         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 621         struct rpc_pipe *pipe;
 622         struct rpc_cred *cred = &gss_cred->gc_base;
 623         struct gss_upcall_msg *gss_msg;
 624         DEFINE_WAIT(wait);
 625         int err;
 626
 627         dprintk("RPC:       %s for uid %u\n",
 628                 __func__, from_kuid(&init_user_ns, cred->cr_uid));
 629 retry:
 630         err = 0;
 631         /* if gssd is down, just skip upcalling altogether */
 632         if (!gssd_running(net)) {
 633                 warn_gssd();
 634                 return -EACCES;
 635         }
 636         gss_msg = gss_setup_upcall(gss_auth, cred);
 637         if (PTR_ERR(gss_msg) == -EAGAIN) {
 638                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
 639                                 sn->pipe_version >= 0, 15 * HZ);
 640                 if (sn->pipe_version < 0) {
 641                         warn_gssd();
 642                         err = -EACCES;
 643                 }
 644                 if (err < 0)
 645                         goto out;
 646                 goto retry;
 647         }
 648         if (IS_ERR(gss_msg)) {
 649                 err = PTR_ERR(gss_msg);
 650                 goto out;
 651         }
 652         pipe = gss_msg->pipe;
 653         for (;;) {
 654                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
 655                 spin_lock(&pipe->lock);
 656                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 657                         break;
 658                 }
 659                 spin_unlock(&pipe->lock);
 660                 if (fatal_signal_pending(current)) {
 661                         err = -ERESTARTSYS;
 662                         goto out_intr;
 663                 }
 664                 schedule();
 665         }
 666         if (gss_msg->ctx)
 667                 gss_cred_set_ctx(cred, gss_msg->ctx);
 668         else
 669                 err = gss_msg->msg.errno;
 670         spin_unlock(&pipe->lock);
 671 out_intr:
 672         finish_wait(&gss_msg->waitqueue, &wait);
 673         gss_release_msg(gss_msg);
 674 out:
 675         dprintk("RPC:       %s for uid %u result %d\n",
 676                 __func__, from_kuid(&init_user_ns, cred->cr_uid), err);
 677         return err;
 678 }
 679
 680 static struct gss_upcall_msg *
 681 gss_find_downcall(struct rpc_pipe *pipe, kuid_t uid)
 682 {
 683         struct gss_upcall_msg *pos;
 684         list_for_each_entry(pos, &pipe->in_downcall, list) {
 685                 if (!uid_eq(pos->uid, uid))
 686                         continue;
 687                 if (!rpc_msg_is_inflight(&pos->msg))
 688                         continue;
 689                 refcount_inc(&pos->count);
 690                 return pos;
 691         }
 692         return NULL;
 693 }
 694
 695 #define MSG_BUF_MAXSIZE 1024
 696
 697 static ssize_t
 698 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 699 {
 700         const void *p, *end;
 701         void *buf;
 702         struct gss_upcall_msg *gss_msg;
 703         struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
 704         struct gss_cl_ctx *ctx;
 705         uid_t id;
 706         kuid_t uid;
 707         ssize_t err = -EFBIG;
 708
 709         if (mlen > MSG_BUF_MAXSIZE)
 710                 goto out;
 711         err = -ENOMEM;
 712         buf = kmalloc(mlen, GFP_NOFS);
 713         if (!buf)
 714                 goto out;
 715
 716         err = -EFAULT;
 717         if (copy_from_user(buf, src, mlen))
 718                 goto err;
 719
 720         end = (const void *)((char *)buf + mlen);
 721         p = simple_get_bytes(buf, end, &id, sizeof(id));
 722         if (IS_ERR(p)) {
 723                 err = PTR_ERR(p);
 724                 goto err;
 725         }
 726
 727         uid = make_kuid(&init_user_ns, id);
 728         if (!uid_valid(uid)) {
 729                 err = -EINVAL;
 730                 goto err;
 731         }
 732
 733         err = -ENOMEM;
 734         ctx = gss_alloc_context();
 735         if (ctx == NULL)
 736                 goto err;
 737
 738         err = -ENOENT;
 739         /* Find a matching upcall */
 740         spin_lock(&pipe->lock);
 741         gss_msg = gss_find_downcall(pipe, uid);
 742         if (gss_msg == NULL) {
 743                 spin_unlock(&pipe->lock);
 744                 goto err_put_ctx;
 745         }
 746         list_del_init(&gss_msg->list);
 747         spin_unlock(&pipe->lock);
 748
 749         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 750         if (IS_ERR(p)) {
 751                 err = PTR_ERR(p);
 752                 switch (err) {
 753                 case -EACCES:
 754                 case -EKEYEXPIRED:
 755                         gss_msg->msg.errno = err;
 756                         err = mlen;
 757                         break;
 758                 case -EFAULT:
 759                 case -ENOMEM:
 760                 case -EINVAL:
 761                 case -ENOSYS:
 762                         gss_msg->msg.errno = -EAGAIN;
 763                         break;
 764                 default:
 765                         printk(KERN_CRIT "%s: bad return from "
 766                                 "gss_fill_context: %zd\n", __func__, err);
 767                         gss_msg->msg.errno = -EIO;
 768                 }
 769                 goto err_release_msg;
 770         }
 771         gss_msg->ctx = gss_get_ctx(ctx);
 772         err = mlen;
 773
 774 err_release_msg:
 775         spin_lock(&pipe->lock);
 776         __gss_unhash_msg(gss_msg);
 777         spin_unlock(&pipe->lock);
 778         gss_release_msg(gss_msg);
 779 err_put_ctx:
 780         gss_put_ctx(ctx);
 781 err:
 782         kfree(buf);
 783 out:
 784         dprintk("RPC:       %s returning %zd\n", __func__, err);
 785         return err;
 786 }
 787
 788 static int gss_pipe_open(struct inode *inode, int new_version)
 789 {
 790         struct net *net = inode->i_sb->s_fs_info;
 791         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 792         int ret = 0;
 793
 794         spin_lock(&pipe_version_lock);
 795         if (sn->pipe_version < 0) {
 796                 /* First open of any gss pipe determines the version: */
 797                 sn->pipe_version = new_version;
 798                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 799                 wake_up(&pipe_version_waitqueue);
 800         } else if (sn->pipe_version != new_version) {
 801                 /* Trying to open a pipe of a different version */
 802                 ret = -EBUSY;
 803                 goto out;
 804         }
 805         atomic_inc(&sn->pipe_users);
 806 out:
 807         spin_unlock(&pipe_version_lock);
 808         return ret;
 809
 810 }
 811
 812 static int gss_pipe_open_v0(struct inode *inode)
 813 {
 814         return gss_pipe_open(inode, 0);
 815 }
 816
 817 static int gss_pipe_open_v1(struct inode *inode)
 818 {
 819         return gss_pipe_open(inode, 1);
 820 }
 821
 822 static void
 823 gss_pipe_release(struct inode *inode)
 824 {
 825         struct net *net = inode->i_sb->s_fs_info;
 826         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 827         struct gss_upcall_msg *gss_msg;
 828
 829 restart:
 830         spin_lock(&pipe->lock);
 831         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
 832
 833                 if (!list_empty(&gss_msg->msg.list))
 834                         continue;
 835                 gss_msg->msg.errno = -EPIPE;
 836                 refcount_inc(&gss_msg->count);
 837                 __gss_unhash_msg(gss_msg);
 838                 spin_unlock(&pipe->lock);
 839                 gss_release_msg(gss_msg);
 840                 goto restart;
 841         }
 842         spin_unlock(&pipe->lock);
 843
 844         put_pipe_version(net);
 845 }
 846
 847 static void
 848 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 849 {
 850         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 851
 852         if (msg->errno < 0) {
 853                 dprintk("RPC:       %s releasing msg %p\n",
 854                         __func__, gss_msg);
 855                 refcount_inc(&gss_msg->count);
 856                 gss_unhash_msg(gss_msg);
 857                 if (msg->errno == -ETIMEDOUT)
 858                         warn_gssd();
 859                 gss_release_msg(gss_msg);
 860         }
 861         gss_release_msg(gss_msg);
 862 }
 863
 864 static void gss_pipe_dentry_destroy(struct dentry *dir,
 865                 struct rpc_pipe_dir_object *pdo)
 866 {
 867         struct gss_pipe *gss_pipe = pdo->pdo_data;
 868         struct rpc_pipe *pipe = gss_pipe->pipe;
 869
 870         if (pipe->dentry != NULL) {
 871                 rpc_unlink(pipe->dentry);
 872                 pipe->dentry = NULL;
 873         }
 874 }
 875
 876 static int gss_pipe_dentry_create(struct dentry *dir,
 877                 struct rpc_pipe_dir_object *pdo)
 878 {
 879         struct gss_pipe *p = pdo->pdo_data;
 880         struct dentry *dentry;
 881
 882         dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
 883         if (IS_ERR(dentry))
 884                 return PTR_ERR(dentry);
 885         p->pipe->dentry = dentry;
 886         return 0;
 887 }
 888
 889 static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
 890         .create = gss_pipe_dentry_create,
 891         .destroy = gss_pipe_dentry_destroy,
 892 };
 893
 894 static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
 895                 const char *name,
 896                 const struct rpc_pipe_ops *upcall_ops)
 897 {
 898         struct gss_pipe *p;
 899         int err = -ENOMEM;
 900
 901         p = kmalloc(sizeof(*p), GFP_KERNEL);
 902         if (p == NULL)
 903                 goto err;
 904         p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 905         if (IS_ERR(p->pipe)) {
 906                 err = PTR_ERR(p->pipe);
 907                 goto err_free_gss_pipe;
 908         }
 909         p->name = name;
 910         p->clnt = clnt;
 911         kref_init(&p->kref);
 912         rpc_init_pipe_dir_object(&p->pdo,
 913                         &gss_pipe_dir_object_ops,
 914                         p);
 915         return p;
 916 err_free_gss_pipe:
 917         kfree(p);
 918 err:
 919         return ERR_PTR(err);
 920 }
 921
 922 struct gss_alloc_pdo {
 923         struct rpc_clnt *clnt;
 924         const char *name;
 925         const struct rpc_pipe_ops *upcall_ops;
 926 };
 927
 928 static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
 929 {
 930         struct gss_pipe *gss_pipe;
 931         struct gss_alloc_pdo *args = data;
 932
 933         if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
 934                 return 0;
 935         gss_pipe = container_of(pdo, struct gss_pipe, pdo);
 936         if (strcmp(gss_pipe->name, args->name) != 0)
 937                 return 0;
 938         if (!kref_get_unless_zero(&gss_pipe->kref))
 939                 return 0;
 940         return 1;
 941 }
 942
 943 static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
 944 {
 945         struct gss_pipe *gss_pipe;
 946         struct gss_alloc_pdo *args = data;
 947
 948         gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
 949         if (!IS_ERR(gss_pipe))
 950                 return &gss_pipe->pdo;
 951         return NULL;
 952 }
 953
 954 static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
 955                 const char *name,
 956                 const struct rpc_pipe_ops *upcall_ops)
 957 {
 958         struct net *net = rpc_net_ns(clnt);
 959         struct rpc_pipe_dir_object *pdo;
 960         struct gss_alloc_pdo args = {
 961                 .clnt = clnt,
 962                 .name = name,
 963                 .upcall_ops = upcall_ops,
 964         };
 965
 966         pdo = rpc_find_or_alloc_pipe_dir_object(net,
 967                         &clnt->cl_pipedir_objects,
 968                         gss_pipe_match_pdo,
 969                         gss_pipe_alloc_pdo,
 970                         &args);
 971         if (pdo != NULL)
 972                 return container_of(pdo, struct gss_pipe, pdo);
 973         return ERR_PTR(-ENOMEM);
 974 }
 975
 976 static void __gss_pipe_free(struct gss_pipe *p)
 977 {
 978         struct rpc_clnt *clnt = p->clnt;
 979         struct net *net = rpc_net_ns(clnt);
 980
 981         rpc_remove_pipe_dir_object(net,
 982                         &clnt->cl_pipedir_objects,
 983                         &p->pdo);
 984         rpc_destroy_pipe_data(p->pipe);
 985         kfree(p);
 986 }
 987
 988 static void __gss_pipe_release(struct kref *kref)
 989 {
 990         struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
 991
 992         __gss_pipe_free(p);
 993 }
 994
 995 static void gss_pipe_free(struct gss_pipe *p)
 996 {
 997         if (p != NULL)
 998                 kref_put(&p->kref, __gss_pipe_release);
 999 }
1000
1001 /*
1002  * NOTE: we have the opportunity to use different
1003  * parameters based on the input flavor (which must be a pseudoflavor)
1004  */
1005 static struct gss_auth *
1006 gss_create_new(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1007 {
1008         rpc_authflavor_t flavor = args->pseudoflavor;
1009         struct gss_auth *gss_auth;
1010         struct gss_pipe *gss_pipe;
1011         struct rpc_auth * auth;
1012         int err = -ENOMEM; /* XXX? */
1013
1014         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
1015
1016         if (!try_module_get(THIS_MODULE))
1017                 return ERR_PTR(err);
1018         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
1019                 goto out_dec;
1020         INIT_HLIST_NODE(&gss_auth->hash);
1021         gss_auth->target_name = NULL;
1022         if (args->target_name) {
1023                 gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
1024                 if (gss_auth->target_name == NULL)
1025                         goto err_free;
1026         }
1027         gss_auth->client = clnt;
1028         gss_auth->net = get_net(rpc_net_ns(clnt));
1029         err = -EINVAL;
1030         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
1031         if (!gss_auth->mech) {
1032                 dprintk("RPC:       Pseudoflavor %d not found!\n", flavor);
1033                 goto err_put_net;
1034         }
1035         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
1036         if (gss_auth->service == 0)
1037                 goto err_put_mech;
1038         if (!gssd_running(gss_auth->net))
1039                 goto err_put_mech;
1040         auth = &gss_auth->rpc_auth;
1041         auth->au_cslack = GSS_CRED_SLACK >> 2;
1042         auth->au_rslack = GSS_VERF_SLACK >> 2;
1043         auth->au_flags = 0;
1044         auth->au_ops = &authgss_ops;
1045         auth->au_flavor = flavor;
1046         if (gss_pseudoflavor_to_datatouch(gss_auth->mech, flavor))
1047                 auth->au_flags |= RPCAUTH_AUTH_DATATOUCH;
1048         atomic_set(&auth->au_count, 1);
1049         kref_init(&gss_auth->kref);
1050
1051         err = rpcauth_init_credcache(auth);
1052         if (err)
1053                 goto err_put_mech;
1054         /*
1055          * Note: if we created the old pipe first, then someone who
1056          * examined the directory at the right moment might conclude
1057          * that we supported only the old pipe.  So we instead create
1058          * the new pipe first.
1059          */
1060         gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
1061         if (IS_ERR(gss_pipe)) {
1062                 err = PTR_ERR(gss_pipe);
1063                 goto err_destroy_credcache;
1064         }
1065         gss_auth->gss_pipe[1] = gss_pipe;
1066
1067         gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
1068                         &gss_upcall_ops_v0);
1069         if (IS_ERR(gss_pipe)) {
1070                 err = PTR_ERR(gss_pipe);
1071                 goto err_destroy_pipe_1;
1072         }
1073         gss_auth->gss_pipe[0] = gss_pipe;
1074
1075         return gss_auth;
1076 err_destroy_pipe_1:
1077         gss_pipe_free(gss_auth->gss_pipe[1]);
1078 err_destroy_credcache:
1079         rpcauth_destroy_credcache(auth);
1080 err_put_mech:
1081         gss_mech_put(gss_auth->mech);
1082 err_put_net:
1083         put_net(gss_auth->net);
1084 err_free:
1085         kfree(gss_auth->target_name);
1086         kfree(gss_auth);
1087 out_dec:
1088         module_put(THIS_MODULE);
1089         return ERR_PTR(err);
1090 }
1091
1092 static void
1093 gss_free(struct gss_auth *gss_auth)
1094 {
1095         gss_pipe_free(gss_auth->gss_pipe[0]);
1096         gss_pipe_free(gss_auth->gss_pipe[1]);
1097         gss_mech_put(gss_auth->mech);
1098         put_net(gss_auth->net);
1099         kfree(gss_auth->target_name);
1100
1101         kfree(gss_auth);
1102         module_put(THIS_MODULE);
1103 }
1104
1105 static void
1106 gss_free_callback(struct kref *kref)
1107 {
1108         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1109
1110         gss_free(gss_auth);
1111 }
1112
1113 static void
1114 gss_put_auth(struct gss_auth *gss_auth)
1115 {
1116         kref_put(&gss_auth->kref, gss_free_callback);
1117 }
1118
1119 static void
1120 gss_destroy(struct rpc_auth *auth)
1121 {
1122         struct gss_auth *gss_auth = container_of(auth,
1123                         struct gss_auth, rpc_auth);
1124
1125         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
1126                         auth, auth->au_flavor);
1127
1128         if (hash_hashed(&gss_auth->hash)) {
1129                 spin_lock(&gss_auth_hash_lock);
1130                 hash_del(&gss_auth->hash);
1131                 spin_unlock(&gss_auth_hash_lock);
1132         }
1133
1134         gss_pipe_free(gss_auth->gss_pipe[0]);
1135         gss_auth->gss_pipe[0] = NULL;
1136         gss_pipe_free(gss_auth->gss_pipe[1]);
1137         gss_auth->gss_pipe[1] = NULL;
1138         rpcauth_destroy_credcache(auth);
1139
1140         gss_put_auth(gss_auth);
1141 }
1142
1143 /*
1144  * Auths may be shared between rpc clients that were cloned from a
1145  * common client with the same xprt, if they also share the flavor and
1146  * target_name.
1147  *
1148  * The auth is looked up from the oldest parent sharing the same
1149  * cl_xprt, and the auth itself references only that common parent
1150  * (which is guaranteed to last as long as any of its descendants).
1151  */
1152 static struct gss_auth *
1153 gss_auth_find_or_add_hashed(const struct rpc_auth_create_args *args,
1154                 struct rpc_clnt *clnt,
1155                 struct gss_auth *new)
1156 {
1157         struct gss_auth *gss_auth;
1158         unsigned long hashval = (unsigned long)clnt;
1159
1160         spin_lock(&gss_auth_hash_lock);
1161         hash_for_each_possible(gss_auth_hash_table,
1162                         gss_auth,
1163                         hash,
1164                         hashval) {
1165                 if (gss_auth->client != clnt)
1166                         continue;
1167                 if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1168                         continue;
1169                 if (gss_auth->target_name != args->target_name) {
1170                         if (gss_auth->target_name == NULL)
1171                                 continue;
1172                         if (args->target_name == NULL)
1173                                 continue;
1174                         if (strcmp(gss_auth->target_name, args->target_name))
1175                                 continue;
1176                 }
1177                 if (!atomic_inc_not_zero(&gss_auth->rpc_auth.au_count))
1178                         continue;
1179                 goto out;
1180         }
1181         if (new)
1182                 hash_add(gss_auth_hash_table, &new->hash, hashval);
1183         gss_auth = new;
1184 out:
1185         spin_unlock(&gss_auth_hash_lock);
1186         return gss_auth;
1187 }
1188
1189 static struct gss_auth *
1190 gss_create_hashed(const struct rpc_auth_create_args *args,
1191                   struct rpc_clnt *clnt)
1192 {
1193         struct gss_auth *gss_auth;
1194         struct gss_auth *new;
1195
1196         gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1197         if (gss_auth != NULL)
1198                 goto out;
1199         new = gss_create_new(args, clnt);
1200         if (IS_ERR(new))
1201                 return new;
1202         gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1203         if (gss_auth != new)
1204                 gss_destroy(&new->rpc_auth);
1205 out:
1206         return gss_auth;
1207 }
1208
1209 static struct rpc_auth *
1210 gss_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1211 {
1212         struct gss_auth *gss_auth;
1213         struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
1214
1215         while (clnt != clnt->cl_parent) {
1216                 struct rpc_clnt *parent = clnt->cl_parent;
1217                 /* Find the original parent for this transport */
1218                 if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
1219                         break;
1220                 clnt = parent;
1221         }
1222
1223         gss_auth = gss_create_hashed(args, clnt);
1224         if (IS_ERR(gss_auth))
1225                 return ERR_CAST(gss_auth);
1226         return &gss_auth->rpc_auth;
1227 }
1228
1229 /*
1230  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
1231  * to the server with the GSS control procedure field set to
1232  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1233  * all RPCSEC_GSS state associated with that context.
1234  */
1235 static int
1236 gss_destroying_context(struct rpc_cred *cred)
1237 {
1238         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1239         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1240         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1241         struct rpc_task *task;
1242
1243         if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
1244                 return 0;
1245
1246         ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1247         cred->cr_ops = &gss_nullops;
1248
1249         /* Take a reference to ensure the cred will be destroyed either
1250          * by the RPC call or by the put_rpccred() below */
1251         get_rpccred(cred);
1252
1253         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
1254         if (!IS_ERR(task))
1255                 rpc_put_task(task);
1256
1257         put_rpccred(cred);
1258         return 1;
1259 }
1260
1261 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1262  * to create a new cred or context, so they check that things have been
1263  * allocated before freeing them. */
1264 static void
1265 gss_do_free_ctx(struct gss_cl_ctx *ctx)
1266 {
1267         dprintk("RPC:       %s\n", __func__);
1268
1269         gss_delete_sec_context(&ctx->gc_gss_ctx);
1270         kfree(ctx->gc_wire_ctx.data);
1271         kfree(ctx->gc_acceptor.data);
1272         kfree(ctx);
1273 }
1274
1275 static void
1276 gss_free_ctx_callback(struct rcu_head *head)
1277 {
1278         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1279         gss_do_free_ctx(ctx);
1280 }
1281
1282 static void
1283 gss_free_ctx(struct gss_cl_ctx *ctx)
1284 {
1285         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1286 }
1287
1288 static void
1289 gss_free_cred(struct gss_cred *gss_cred)
1290 {
1291         dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1292         kfree(gss_cred);
1293 }
1294
1295 static void
1296 gss_free_cred_callback(struct rcu_head *head)
1297 {
1298         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1299         gss_free_cred(gss_cred);
1300 }
1301
1302 static void
1303 gss_destroy_nullcred(struct rpc_cred *cred)
1304 {
1305         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1306         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1307         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1308
1309         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1310         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1311         if (ctx)
1312                 gss_put_ctx(ctx);
1313         gss_put_auth(gss_auth);
1314 }
1315
1316 static void
1317 gss_destroy_cred(struct rpc_cred *cred)
1318 {
1319
1320         if (gss_destroying_context(cred))
1321                 return;
1322         gss_destroy_nullcred(cred);
1323 }
1324
1325 static int
1326 gss_hash_cred(struct auth_cred *acred, unsigned int hashbits)
1327 {
1328         return hash_64(from_kuid(&init_user_ns, acred->uid), hashbits);
1329 }
1330
1331 /*
1332  * Lookup RPCSEC_GSS cred for the current process
1333  */
1334 static struct rpc_cred *
1335 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1336 {
1337         return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS);
1338 }
1339
1340 static struct rpc_cred *
1341 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp)
1342 {
1343         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1344         struct gss_cred *cred = NULL;
1345         int err = -ENOMEM;
1346
1347         dprintk("RPC:       %s for uid %d, flavor %d\n",
1348                 __func__, from_kuid(&init_user_ns, acred->uid),
1349                 auth->au_flavor);
1350
1351         if (!(cred = kzalloc(sizeof(*cred), gfp)))
1352                 goto out_err;
1353
1354         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1355         /*
1356          * Note: in order to force a call to call_refresh(), we deliberately
1357          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1358          */
1359         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1360         cred->gc_service = gss_auth->service;
1361         cred->gc_principal = NULL;
1362         if (acred->machine_cred)
1363                 cred->gc_principal = acred->principal;
1364         kref_get(&gss_auth->kref);
1365         return &cred->gc_base;
1366
1367 out_err:
1368         dprintk("RPC:       %s failed with error %d\n", __func__, err);
1369         return ERR_PTR(err);
1370 }
1371
1372 static int
1373 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1374 {
1375         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1376         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1377         int err;
1378
1379         do {
1380                 err = gss_create_upcall(gss_auth, gss_cred);
1381         } while (err == -EAGAIN);
1382         return err;
1383 }
1384
1385 static char *
1386 gss_stringify_acceptor(struct rpc_cred *cred)
1387 {
1388         char *string = NULL;
1389         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1390         struct gss_cl_ctx *ctx;
1391         unsigned int len;
1392         struct xdr_netobj *acceptor;
1393
1394         rcu_read_lock();
1395         ctx = rcu_dereference(gss_cred->gc_ctx);
1396         if (!ctx)
1397                 goto out;
1398
1399         len = ctx->gc_acceptor.len;
1400         rcu_read_unlock();
1401
1402         /* no point if there's no string */
1403         if (!len)
1404                 return NULL;
1405 realloc:
1406         string = kmalloc(len + 1, GFP_KERNEL);
1407         if (!string)
1408                 return NULL;
1409
1410         rcu_read_lock();
1411         ctx = rcu_dereference(gss_cred->gc_ctx);
1412
1413         /* did the ctx disappear or was it replaced by one with no acceptor? */
1414         if (!ctx || !ctx->gc_acceptor.len) {
1415                 kfree(string);
1416                 string = NULL;
1417                 goto out;
1418         }
1419
1420         acceptor = &ctx->gc_acceptor;
1421
1422         /*
1423          * Did we find a new acceptor that's longer than the original? Allocate
1424          * a longer buffer and try again.
1425          */
1426         if (len < acceptor->len) {
1427                 len = acceptor->len;
1428                 rcu_read_unlock();
1429                 kfree(string);
1430                 goto realloc;
1431         }
1432
1433         memcpy(string, acceptor->data, acceptor->len);
1434         string[acceptor->len] = '\0';
1435 out:
1436         rcu_read_unlock();
1437         return string;
1438 }
1439
1440 /*
1441  * Returns -EACCES if GSS context is NULL or will expire within the
1442  * timeout (miliseconds)
1443  */
1444 static int
1445 gss_key_timeout(struct rpc_cred *rc)
1446 {
1447         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1448         struct gss_cl_ctx *ctx;
1449         unsigned long timeout = jiffies + (gss_key_expire_timeo * HZ);
1450         int ret = 0;
1451
1452         rcu_read_lock();
1453         ctx = rcu_dereference(gss_cred->gc_ctx);
1454         if (!ctx || time_after(timeout, ctx->gc_expiry))
1455                 ret = -EACCES;
1456         rcu_read_unlock();
1457
1458         return ret;
1459 }
1460
1461 static int
1462 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1463 {
1464         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1465         struct gss_cl_ctx *ctx;
1466         int ret;
1467
1468         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1469                 goto out;
1470         /* Don't match with creds that have expired. */
1471         rcu_read_lock();
1472         ctx = rcu_dereference(gss_cred->gc_ctx);
1473         if (!ctx || time_after(jiffies, ctx->gc_expiry)) {
1474                 rcu_read_unlock();
1475                 return 0;
1476         }
1477         rcu_read_unlock();
1478         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1479                 return 0;
1480 out:
1481         if (acred->principal != NULL) {
1482                 if (gss_cred->gc_principal == NULL)
1483                         return 0;
1484                 ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1485                 goto check_expire;
1486         }
1487         if (gss_cred->gc_principal != NULL)
1488                 return 0;
1489         ret = uid_eq(rc->cr_uid, acred->uid);
1490
1491 check_expire:
1492         if (ret == 0)
1493                 return ret;
1494
1495         /* Notify acred users of GSS context expiration timeout */
1496         if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags) &&
1497             (gss_key_timeout(rc) != 0)) {
1498                 /* test will now be done from generic cred */
1499                 test_and_clear_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
1500                 /* tell NFS layer that key will expire soon */
1501                 set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
1502         }
1503         return ret;
1504 }
1505
1506 /*
1507 * Marshal credentials.
1508 * Maybe we should keep a cached credential for performance reasons.
1509 */
1510 static __be32 *
1511 gss_marshal(struct rpc_task *task, __be32 *p)
1512 {
1513         struct rpc_rqst *req = task->tk_rqstp;
1514         struct rpc_cred *cred = req->rq_cred;
1515         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1516                                                  gc_base);
1517         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1518         __be32          *cred_len;
1519         u32             maj_stat = 0;
1520         struct xdr_netobj mic;
1521         struct kvec     iov;
1522         struct xdr_buf  verf_buf;
1523
1524         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1525
1526         *p++ = htonl(RPC_AUTH_GSS);
1527         cred_len = p++;
1528
1529         spin_lock(&ctx->gc_seq_lock);
1530         req->rq_seqno = ctx->gc_seq++;
1531         spin_unlock(&ctx->gc_seq_lock);
1532
1533         *p++ = htonl((u32) RPC_GSS_VERSION);
1534         *p++ = htonl((u32) ctx->gc_proc);
1535         *p++ = htonl((u32) req->rq_seqno);
1536         *p++ = htonl((u32) gss_cred->gc_service);
1537         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1538         *cred_len = htonl((p - (cred_len + 1)) << 2);
1539
1540         /* We compute the checksum for the verifier over the xdr-encoded bytes
1541          * starting with the xid and ending at the end of the credential: */
1542         iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
1543                                         req->rq_snd_buf.head[0].iov_base);
1544         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1545         xdr_buf_from_iov(&iov, &verf_buf);
1546
1547         /* set verifier flavor*/
1548         *p++ = htonl(RPC_AUTH_GSS);
1549
1550         mic.data = (u8 *)(p + 1);
1551         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1552         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1553                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1554         } else if (maj_stat != 0) {
1555                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1556                 goto out_put_ctx;
1557         }
1558         p = xdr_encode_opaque(p, NULL, mic.len);
1559         gss_put_ctx(ctx);
1560         return p;
1561 out_put_ctx:
1562         gss_put_ctx(ctx);
1563         return NULL;
1564 }
1565
1566 static int gss_renew_cred(struct rpc_task *task)
1567 {
1568         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1569         struct gss_cred *gss_cred = container_of(oldcred,
1570                                                  struct gss_cred,
1571                                                  gc_base);
1572         struct rpc_auth *auth = oldcred->cr_auth;
1573         struct auth_cred acred = {
1574                 .uid = oldcred->cr_uid,
1575                 .principal = gss_cred->gc_principal,
1576                 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
1577         };
1578         struct rpc_cred *new;
1579
1580         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1581         if (IS_ERR(new))
1582                 return PTR_ERR(new);
1583         task->tk_rqstp->rq_cred = new;
1584         put_rpccred(oldcred);
1585         return 0;
1586 }
1587
1588 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1589 {
1590         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1591                 unsigned long now = jiffies;
1592                 unsigned long begin, expire;
1593                 struct gss_cred *gss_cred;
1594
1595                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1596                 begin = gss_cred->gc_upcall_timestamp;
1597                 expire = begin + gss_expired_cred_retry_delay * HZ;
1598
1599                 if (time_in_range_open(now, begin, expire))
1600                         return 1;
1601         }
1602         return 0;
1603 }
1604
1605 /*
1606 * Refresh credentials. XXX - finish
1607 */
1608 static int
1609 gss_refresh(struct rpc_task *task)
1610 {
1611         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1612         int ret = 0;
1613
1614         if (gss_cred_is_negative_entry(cred))
1615                 return -EKEYEXPIRED;
1616
1617         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1618                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1619                 ret = gss_renew_cred(task);
1620                 if (ret < 0)
1621                         goto out;
1622                 cred = task->tk_rqstp->rq_cred;
1623         }
1624
1625         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1626                 ret = gss_refresh_upcall(task);
1627 out:
1628         return ret;
1629 }
1630
1631 /* Dummy refresh routine: used only when destroying the context */
1632 static int
1633 gss_refresh_null(struct rpc_task *task)
1634 {
1635         return 0;
1636 }
1637
1638 static __be32 *
1639 gss_validate(struct rpc_task *task, __be32 *p)
1640 {
1641         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1642         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1643         __be32          *seq = NULL;
1644         struct kvec     iov;
1645         struct xdr_buf  verf_buf;
1646         struct xdr_netobj mic;
1647         u32             flav,len;
1648         u32             maj_stat;
1649         __be32          *ret = ERR_PTR(-EIO);
1650
1651         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1652
1653         flav = ntohl(*p++);
1654         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1655                 goto out_bad;
1656         if (flav != RPC_AUTH_GSS)
1657                 goto out_bad;
1658         seq = kmalloc(4, GFP_NOFS);
1659         if (!seq)
1660                 goto out_bad;
1661         *seq = htonl(task->tk_rqstp->rq_seqno);
1662         iov.iov_base = seq;
1663         iov.iov_len = 4;
1664         xdr_buf_from_iov(&iov, &verf_buf);
1665         mic.data = (u8 *)p;
1666         mic.len = len;
1667
1668         ret = ERR_PTR(-EACCES);
1669         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1670         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1671                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1672         if (maj_stat) {
1673                 dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1674                         task->tk_pid, __func__, maj_stat);
1675                 goto out_bad;
1676         }
1677         /* We leave it to unwrap to calculate au_rslack. For now we just
1678          * calculate the length of the verifier: */
1679         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1680         gss_put_ctx(ctx);
1681         dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1682                         task->tk_pid, __func__);
1683         kfree(seq);
1684         return p + XDR_QUADLEN(len);
1685 out_bad:
1686         gss_put_ctx(ctx);
1687         dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
1688                 PTR_ERR(ret));
1689         kfree(seq);
1690         return ret;
1691 }
1692
1693 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1694                                 __be32 *p, void *obj)
1695 {
1696         struct xdr_stream xdr;
1697
1698         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1699         encode(rqstp, &xdr, obj);
1700 }
1701
1702 static inline int
1703 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1704                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1705                    __be32 *p, void *obj)
1706 {
1707         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1708         struct xdr_buf  integ_buf;
1709         __be32          *integ_len = NULL;
1710         struct xdr_netobj mic;
1711         u32             offset;
1712         __be32          *q;
1713         struct kvec     *iov;
1714         u32             maj_stat = 0;
1715         int             status = -EIO;
1716
1717         integ_len = p++;
1718         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1719         *p++ = htonl(rqstp->rq_seqno);
1720
1721         gss_wrap_req_encode(encode, rqstp, p, obj);
1722
1723         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1724                                 offset, snd_buf->len - offset))
1725                 return status;
1726         *integ_len = htonl(integ_buf.len);
1727
1728         /* guess whether we're in the head or the tail: */
1729         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1730                 iov = snd_buf->tail;
1731         else
1732                 iov = snd_buf->head;
1733         p = iov->iov_base + iov->iov_len;
1734         mic.data = (u8 *)(p + 1);
1735
1736         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1737         status = -EIO; /* XXX? */
1738         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1739                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1740         else if (maj_stat)
1741                 return status;
1742         q = xdr_encode_opaque(p, NULL, mic.len);
1743
1744         offset = (u8 *)q - (u8 *)p;
1745         iov->iov_len += offset;
1746         snd_buf->len += offset;
1747         return 0;
1748 }
1749
1750 static void
1751 priv_release_snd_buf(struct rpc_rqst *rqstp)
1752 {
1753         int i;
1754
1755         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1756                 __free_page(rqstp->rq_enc_pages[i]);
1757         kfree(rqstp->rq_enc_pages);
1758         rqstp->rq_release_snd_buf = NULL;
1759 }
1760
1761 static int
1762 alloc_enc_pages(struct rpc_rqst *rqstp)
1763 {
1764         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1765         int first, last, i;
1766
1767         if (rqstp->rq_release_snd_buf)
1768                 rqstp->rq_release_snd_buf(rqstp);
1769
1770         if (snd_buf->page_len == 0) {
1771                 rqstp->rq_enc_pages_num = 0;
1772                 return 0;
1773         }
1774
1775         first = snd_buf->page_base >> PAGE_SHIFT;
1776         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_SHIFT;
1777         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1778         rqstp->rq_enc_pages
1779                 = kmalloc_array(rqstp->rq_enc_pages_num,
1780                                 sizeof(struct page *),
1781                                 GFP_NOFS);
1782         if (!rqstp->rq_enc_pages)
1783                 goto out;
1784         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1785                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1786                 if (rqstp->rq_enc_pages[i] == NULL)
1787                         goto out_free;
1788         }
1789         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1790         return 0;
1791 out_free:
1792         rqstp->rq_enc_pages_num = i;
1793         priv_release_snd_buf(rqstp);
1794 out:
1795         return -EAGAIN;
1796 }
1797
1798 static inline int
1799 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1800                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1801                   __be32 *p, void *obj)
1802 {
1803         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1804         u32             offset;
1805         u32             maj_stat;
1806         int             status;
1807         __be32          *opaque_len;
1808         struct page     **inpages;
1809         int             first;
1810         int             pad;
1811         struct kvec     *iov;
1812         char            *tmp;
1813
1814         opaque_len = p++;
1815         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1816         *p++ = htonl(rqstp->rq_seqno);
1817
1818         gss_wrap_req_encode(encode, rqstp, p, obj);
1819
1820         status = alloc_enc_pages(rqstp);
1821         if (status)
1822                 return status;
1823         first = snd_buf->page_base >> PAGE_SHIFT;
1824         inpages = snd_buf->pages + first;
1825         snd_buf->pages = rqstp->rq_enc_pages;
1826         snd_buf->page_base -= first << PAGE_SHIFT;
1827         /*
1828          * Give the tail its own page, in case we need extra space in the
1829          * head when wrapping:
1830          *
1831          * call_allocate() allocates twice the slack space required
1832          * by the authentication flavor to rq_callsize.
1833          * For GSS, slack is GSS_CRED_SLACK.
1834          */
1835         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1836                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1837                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1838                 snd_buf->tail[0].iov_base = tmp;
1839         }
1840         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1841         /* slack space should prevent this ever happening: */
1842         BUG_ON(snd_buf->len > snd_buf->buflen);
1843         status = -EIO;
1844         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1845          * done anyway, so it's safe to put the request on the wire: */
1846         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1847                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1848         else if (maj_stat)
1849                 return status;
1850
1851         *opaque_len = htonl(snd_buf->len - offset);
1852         /* guess whether we're in the head or the tail: */
1853         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1854                 iov = snd_buf->tail;
1855         else
1856                 iov = snd_buf->head;
1857         p = iov->iov_base + iov->iov_len;
1858         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1859         memset(p, 0, pad);
1860         iov->iov_len += pad;
1861         snd_buf->len += pad;
1862
1863         return 0;
1864 }
1865
1866 static int
1867 gss_wrap_req(struct rpc_task *task,
1868              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1869 {
1870         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1871         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1872                         gc_base);
1873         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1874         int             status = -EIO;
1875
1876         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1877         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1878                 /* The spec seems a little ambiguous here, but I think that not
1879                  * wrapping context destruction requests makes the most sense.
1880                  */
1881                 gss_wrap_req_encode(encode, rqstp, p, obj);
1882                 status = 0;
1883                 goto out;
1884         }
1885         switch (gss_cred->gc_service) {
1886         case RPC_GSS_SVC_NONE:
1887                 gss_wrap_req_encode(encode, rqstp, p, obj);
1888                 status = 0;
1889                 break;
1890         case RPC_GSS_SVC_INTEGRITY:
1891                 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1892                 break;
1893         case RPC_GSS_SVC_PRIVACY:
1894                 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1895                 break;
1896         }
1897 out:
1898         gss_put_ctx(ctx);
1899         dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1900         return status;
1901 }
1902
1903 static inline int
1904 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1905                 struct rpc_rqst *rqstp, __be32 **p)
1906 {
1907         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1908         struct xdr_buf integ_buf;
1909         struct xdr_netobj mic;
1910         u32 data_offset, mic_offset;
1911         u32 integ_len;
1912         u32 maj_stat;
1913         int status = -EIO;
1914
1915         integ_len = ntohl(*(*p)++);
1916         if (integ_len & 3)
1917                 return status;
1918         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1919         mic_offset = integ_len + data_offset;
1920         if (mic_offset > rcv_buf->len)
1921                 return status;
1922         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1923                 return status;
1924
1925         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1926                                 mic_offset - data_offset))
1927                 return status;
1928
1929         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1930                 return status;
1931
1932         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1933         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1934                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1935         if (maj_stat != GSS_S_COMPLETE)
1936                 return status;
1937         return 0;
1938 }
1939
1940 static inline int
1941 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1942                 struct rpc_rqst *rqstp, __be32 **p)
1943 {
1944         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1945         u32 offset;
1946         u32 opaque_len;
1947         u32 maj_stat;
1948         int status = -EIO;
1949
1950         opaque_len = ntohl(*(*p)++);
1951         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1952         if (offset + opaque_len > rcv_buf->len)
1953                 return status;
1954         /* remove padding: */
1955         rcv_buf->len = offset + opaque_len;
1956
1957         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1958         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1959                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1960         if (maj_stat != GSS_S_COMPLETE)
1961                 return status;
1962         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1963                 return status;
1964
1965         return 0;
1966 }
1967
1968 static int
1969 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1970                       __be32 *p, void *obj)
1971 {
1972         struct xdr_stream xdr;
1973
1974         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1975         return decode(rqstp, &xdr, obj);
1976 }
1977
1978 static int
1979 gss_unwrap_resp(struct rpc_task *task,
1980                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1981 {
1982         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1983         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1984                         gc_base);
1985         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1986         __be32          *savedp = p;
1987         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1988         int             savedlen = head->iov_len;
1989         int             status = -EIO;
1990
1991         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1992                 goto out_decode;
1993         switch (gss_cred->gc_service) {
1994         case RPC_GSS_SVC_NONE:
1995                 break;
1996         case RPC_GSS_SVC_INTEGRITY:
1997                 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1998                 if (status)
1999                         goto out;
2000                 break;
2001         case RPC_GSS_SVC_PRIVACY:
2002                 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
2003                 if (status)
2004                         goto out;
2005                 break;
2006         }
2007         /* take into account extra slack for integrity and privacy cases: */
2008         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
2009                                                 + (savedlen - head->iov_len);
2010 out_decode:
2011         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
2012 out:
2013         gss_put_ctx(ctx);
2014         dprintk("RPC: %5u %s returning %d\n",
2015                 task->tk_pid, __func__, status);
2016         return status;
2017 }
2018
2019 static const struct rpc_authops authgss_ops = {
2020         .owner          = THIS_MODULE,
2021         .au_flavor      = RPC_AUTH_GSS,
2022         .au_name        = "RPCSEC_GSS",
2023         .create         = gss_create,
2024         .destroy        = gss_destroy,
2025         .hash_cred      = gss_hash_cred,
2026         .lookup_cred    = gss_lookup_cred,
2027         .crcreate       = gss_create_cred,
2028         .list_pseudoflavors = gss_mech_list_pseudoflavors,
2029         .info2flavor    = gss_mech_info2flavor,
2030         .flavor2info    = gss_mech_flavor2info,
2031 };
2032
2033 static const struct rpc_credops gss_credops = {
2034         .cr_name                = "AUTH_GSS",
2035         .crdestroy              = gss_destroy_cred,
2036         .cr_init                = gss_cred_init,
2037         .crbind                 = rpcauth_generic_bind_cred,
2038         .crmatch                = gss_match,
2039         .crmarshal              = gss_marshal,
2040         .crrefresh              = gss_refresh,
2041         .crvalidate             = gss_validate,
2042         .crwrap_req             = gss_wrap_req,
2043         .crunwrap_resp          = gss_unwrap_resp,
2044         .crkey_timeout          = gss_key_timeout,
2045         .crstringify_acceptor   = gss_stringify_acceptor,
2046 };
2047
2048 static const struct rpc_credops gss_nullops = {
2049         .cr_name                = "AUTH_GSS",
2050         .crdestroy              = gss_destroy_nullcred,
2051         .crbind                 = rpcauth_generic_bind_cred,
2052         .crmatch                = gss_match,
2053         .crmarshal              = gss_marshal,
2054         .crrefresh              = gss_refresh_null,
2055         .crvalidate             = gss_validate,
2056         .crwrap_req             = gss_wrap_req,
2057         .crunwrap_resp          = gss_unwrap_resp,
2058         .crstringify_acceptor   = gss_stringify_acceptor,
2059 };
2060
2061 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
2062         .upcall         = rpc_pipe_generic_upcall,
2063         .downcall       = gss_pipe_downcall,
2064         .destroy_msg    = gss_pipe_destroy_msg,
2065         .open_pipe      = gss_pipe_open_v0,
2066         .release_pipe   = gss_pipe_release,
2067 };
2068
2069 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
2070         .upcall         = rpc_pipe_generic_upcall,
2071         .downcall       = gss_pipe_downcall,
2072         .destroy_msg    = gss_pipe_destroy_msg,
2073         .open_pipe      = gss_pipe_open_v1,
2074         .release_pipe   = gss_pipe_release,
2075 };
2076
2077 static __net_init int rpcsec_gss_init_net(struct net *net)
2078 {
2079         return gss_svc_init_net(net);
2080 }
2081
2082 static __net_exit void rpcsec_gss_exit_net(struct net *net)
2083 {
2084         gss_svc_shutdown_net(net);
2085 }
2086
2087 static struct pernet_operations rpcsec_gss_net_ops = {
2088         .init = rpcsec_gss_init_net,
2089         .exit = rpcsec_gss_exit_net,
2090 };
2091
2092 /*
2093  * Initialize RPCSEC_GSS module
2094  */
2095 static int __init init_rpcsec_gss(void)
2096 {
2097         int err = 0;
2098
2099         err = rpcauth_register(&authgss_ops);
2100         if (err)
2101                 goto out;
2102         err = gss_svc_init();
2103         if (err)
2104                 goto out_unregister;
2105         err = register_pernet_subsys(&rpcsec_gss_net_ops);
2106         if (err)
2107                 goto out_svc_exit;
2108         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
2109         return 0;
2110 out_svc_exit:
2111         gss_svc_shutdown();
2112 out_unregister:
2113         rpcauth_unregister(&authgss_ops);
2114 out:
2115         return err;
2116 }
2117
2118 static void __exit exit_rpcsec_gss(void)
2119 {
2120         unregister_pernet_subsys(&rpcsec_gss_net_ops);
2121         gss_svc_shutdown();
2122         rpcauth_unregister(&authgss_ops);
2123         rcu_barrier(); /* Wait for completion of call_rcu()'s */
2124 }
2125
2126 MODULE_ALIAS("rpc-auth-6");
2127 MODULE_LICENSE("GPL");
2128 module_param_named(expired_cred_retry_delay,
2129                    gss_expired_cred_retry_delay,
2130                    uint, 0644);
2131 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
2132                 "the RPC engine retries an expired credential");
2133
2134 module_param_named(key_expire_timeo,
2135                    gss_key_expire_timeo,
2136                    uint, 0644);
2137 MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
2138                 "credential keys lifetime where the NFS layer cleans up "
2139                 "prior to key expiration");
2140
2141 module_init(init_rpcsec_gss)
2142 module_exit(exit_rpcsec_gss)