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 (auth && 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 #define MSG_BUF_MAXSIZE 1024
 681
 682 static ssize_t
 683 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 684 {
 685         const void *p, *end;
 686         void *buf;
 687         struct gss_upcall_msg *gss_msg;
 688         struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
 689         struct gss_cl_ctx *ctx;
 690         uid_t id;
 691         kuid_t uid;
 692         ssize_t err = -EFBIG;
 693
 694         if (mlen > MSG_BUF_MAXSIZE)
 695                 goto out;
 696         err = -ENOMEM;
 697         buf = kmalloc(mlen, GFP_NOFS);
 698         if (!buf)
 699                 goto out;
 700
 701         err = -EFAULT;
 702         if (copy_from_user(buf, src, mlen))
 703                 goto err;
 704
 705         end = (const void *)((char *)buf + mlen);
 706         p = simple_get_bytes(buf, end, &id, sizeof(id));
 707         if (IS_ERR(p)) {
 708                 err = PTR_ERR(p);
 709                 goto err;
 710         }
 711
 712         uid = make_kuid(&init_user_ns, id);
 713         if (!uid_valid(uid)) {
 714                 err = -EINVAL;
 715                 goto err;
 716         }
 717
 718         err = -ENOMEM;
 719         ctx = gss_alloc_context();
 720         if (ctx == NULL)
 721                 goto err;
 722
 723         err = -ENOENT;
 724         /* Find a matching upcall */
 725         spin_lock(&pipe->lock);
 726         gss_msg = __gss_find_upcall(pipe, uid, NULL);
 727         if (gss_msg == NULL) {
 728                 spin_unlock(&pipe->lock);
 729                 goto err_put_ctx;
 730         }
 731         list_del_init(&gss_msg->list);
 732         spin_unlock(&pipe->lock);
 733
 734         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 735         if (IS_ERR(p)) {
 736                 err = PTR_ERR(p);
 737                 switch (err) {
 738                 case -EACCES:
 739                 case -EKEYEXPIRED:
 740                         gss_msg->msg.errno = err;
 741                         err = mlen;
 742                         break;
 743                 case -EFAULT:
 744                 case -ENOMEM:
 745                 case -EINVAL:
 746                 case -ENOSYS:
 747                         gss_msg->msg.errno = -EAGAIN;
 748                         break;
 749                 default:
 750                         printk(KERN_CRIT "%s: bad return from "
 751                                 "gss_fill_context: %zd\n", __func__, err);
 752                         gss_msg->msg.errno = -EIO;
 753                 }
 754                 goto err_release_msg;
 755         }
 756         gss_msg->ctx = gss_get_ctx(ctx);
 757         err = mlen;
 758
 759 err_release_msg:
 760         spin_lock(&pipe->lock);
 761         __gss_unhash_msg(gss_msg);
 762         spin_unlock(&pipe->lock);
 763         gss_release_msg(gss_msg);
 764 err_put_ctx:
 765         gss_put_ctx(ctx);
 766 err:
 767         kfree(buf);
 768 out:
 769         dprintk("RPC:       %s returning %zd\n", __func__, err);
 770         return err;
 771 }
 772
 773 static int gss_pipe_open(struct inode *inode, int new_version)
 774 {
 775         struct net *net = inode->i_sb->s_fs_info;
 776         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 777         int ret = 0;
 778
 779         spin_lock(&pipe_version_lock);
 780         if (sn->pipe_version < 0) {
 781                 /* First open of any gss pipe determines the version: */
 782                 sn->pipe_version = new_version;
 783                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 784                 wake_up(&pipe_version_waitqueue);
 785         } else if (sn->pipe_version != new_version) {
 786                 /* Trying to open a pipe of a different version */
 787                 ret = -EBUSY;
 788                 goto out;
 789         }
 790         atomic_inc(&sn->pipe_users);
 791 out:
 792         spin_unlock(&pipe_version_lock);
 793         return ret;
 794
 795 }
 796
 797 static int gss_pipe_open_v0(struct inode *inode)
 798 {
 799         return gss_pipe_open(inode, 0);
 800 }
 801
 802 static int gss_pipe_open_v1(struct inode *inode)
 803 {
 804         return gss_pipe_open(inode, 1);
 805 }
 806
 807 static void
 808 gss_pipe_release(struct inode *inode)
 809 {
 810         struct net *net = inode->i_sb->s_fs_info;
 811         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 812         struct gss_upcall_msg *gss_msg;
 813
 814 restart:
 815         spin_lock(&pipe->lock);
 816         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
 817
 818                 if (!list_empty(&gss_msg->msg.list))
 819                         continue;
 820                 gss_msg->msg.errno = -EPIPE;
 821                 refcount_inc(&gss_msg->count);
 822                 __gss_unhash_msg(gss_msg);
 823                 spin_unlock(&pipe->lock);
 824                 gss_release_msg(gss_msg);
 825                 goto restart;
 826         }
 827         spin_unlock(&pipe->lock);
 828
 829         put_pipe_version(net);
 830 }
 831
 832 static void
 833 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 834 {
 835         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 836
 837         if (msg->errno < 0) {
 838                 dprintk("RPC:       %s releasing msg %p\n",
 839                         __func__, gss_msg);
 840                 refcount_inc(&gss_msg->count);
 841                 gss_unhash_msg(gss_msg);
 842                 if (msg->errno == -ETIMEDOUT)
 843                         warn_gssd();
 844                 gss_release_msg(gss_msg);
 845         }
 846         gss_release_msg(gss_msg);
 847 }
 848
 849 static void gss_pipe_dentry_destroy(struct dentry *dir,
 850                 struct rpc_pipe_dir_object *pdo)
 851 {
 852         struct gss_pipe *gss_pipe = pdo->pdo_data;
 853         struct rpc_pipe *pipe = gss_pipe->pipe;
 854
 855         if (pipe->dentry != NULL) {
 856                 rpc_unlink(pipe->dentry);
 857                 pipe->dentry = NULL;
 858         }
 859 }
 860
 861 static int gss_pipe_dentry_create(struct dentry *dir,
 862                 struct rpc_pipe_dir_object *pdo)
 863 {
 864         struct gss_pipe *p = pdo->pdo_data;
 865         struct dentry *dentry;
 866
 867         dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
 868         if (IS_ERR(dentry))
 869                 return PTR_ERR(dentry);
 870         p->pipe->dentry = dentry;
 871         return 0;
 872 }
 873
 874 static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
 875         .create = gss_pipe_dentry_create,
 876         .destroy = gss_pipe_dentry_destroy,
 877 };
 878
 879 static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
 880                 const char *name,
 881                 const struct rpc_pipe_ops *upcall_ops)
 882 {
 883         struct gss_pipe *p;
 884         int err = -ENOMEM;
 885
 886         p = kmalloc(sizeof(*p), GFP_KERNEL);
 887         if (p == NULL)
 888                 goto err;
 889         p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 890         if (IS_ERR(p->pipe)) {
 891                 err = PTR_ERR(p->pipe);
 892                 goto err_free_gss_pipe;
 893         }
 894         p->name = name;
 895         p->clnt = clnt;
 896         kref_init(&p->kref);
 897         rpc_init_pipe_dir_object(&p->pdo,
 898                         &gss_pipe_dir_object_ops,
 899                         p);
 900         return p;
 901 err_free_gss_pipe:
 902         kfree(p);
 903 err:
 904         return ERR_PTR(err);
 905 }
 906
 907 struct gss_alloc_pdo {
 908         struct rpc_clnt *clnt;
 909         const char *name;
 910         const struct rpc_pipe_ops *upcall_ops;
 911 };
 912
 913 static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
 914 {
 915         struct gss_pipe *gss_pipe;
 916         struct gss_alloc_pdo *args = data;
 917
 918         if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
 919                 return 0;
 920         gss_pipe = container_of(pdo, struct gss_pipe, pdo);
 921         if (strcmp(gss_pipe->name, args->name) != 0)
 922                 return 0;
 923         if (!kref_get_unless_zero(&gss_pipe->kref))
 924                 return 0;
 925         return 1;
 926 }
 927
 928 static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
 929 {
 930         struct gss_pipe *gss_pipe;
 931         struct gss_alloc_pdo *args = data;
 932
 933         gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
 934         if (!IS_ERR(gss_pipe))
 935                 return &gss_pipe->pdo;
 936         return NULL;
 937 }
 938
 939 static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
 940                 const char *name,
 941                 const struct rpc_pipe_ops *upcall_ops)
 942 {
 943         struct net *net = rpc_net_ns(clnt);
 944         struct rpc_pipe_dir_object *pdo;
 945         struct gss_alloc_pdo args = {
 946                 .clnt = clnt,
 947                 .name = name,
 948                 .upcall_ops = upcall_ops,
 949         };
 950
 951         pdo = rpc_find_or_alloc_pipe_dir_object(net,
 952                         &clnt->cl_pipedir_objects,
 953                         gss_pipe_match_pdo,
 954                         gss_pipe_alloc_pdo,
 955                         &args);
 956         if (pdo != NULL)
 957                 return container_of(pdo, struct gss_pipe, pdo);
 958         return ERR_PTR(-ENOMEM);
 959 }
 960
 961 static void __gss_pipe_free(struct gss_pipe *p)
 962 {
 963         struct rpc_clnt *clnt = p->clnt;
 964         struct net *net = rpc_net_ns(clnt);
 965
 966         rpc_remove_pipe_dir_object(net,
 967                         &clnt->cl_pipedir_objects,
 968                         &p->pdo);
 969         rpc_destroy_pipe_data(p->pipe);
 970         kfree(p);
 971 }
 972
 973 static void __gss_pipe_release(struct kref *kref)
 974 {
 975         struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
 976
 977         __gss_pipe_free(p);
 978 }
 979
 980 static void gss_pipe_free(struct gss_pipe *p)
 981 {
 982         if (p != NULL)
 983                 kref_put(&p->kref, __gss_pipe_release);
 984 }
 985
 986 /*
 987  * NOTE: we have the opportunity to use different
 988  * parameters based on the input flavor (which must be a pseudoflavor)
 989  */
 990 static struct gss_auth *
 991 gss_create_new(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
 992 {
 993         rpc_authflavor_t flavor = args->pseudoflavor;
 994         struct gss_auth *gss_auth;
 995         struct gss_pipe *gss_pipe;
 996         struct rpc_auth * auth;
 997         int err = -ENOMEM; /* XXX? */
 998
 999         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
1000
1001         if (!try_module_get(THIS_MODULE))
1002                 return ERR_PTR(err);
1003         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
1004                 goto out_dec;
1005         INIT_HLIST_NODE(&gss_auth->hash);
1006         gss_auth->target_name = NULL;
1007         if (args->target_name) {
1008                 gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
1009                 if (gss_auth->target_name == NULL)
1010                         goto err_free;
1011         }
1012         gss_auth->client = clnt;
1013         gss_auth->net = get_net(rpc_net_ns(clnt));
1014         err = -EINVAL;
1015         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
1016         if (!gss_auth->mech) {
1017                 dprintk("RPC:       Pseudoflavor %d not found!\n", flavor);
1018                 goto err_put_net;
1019         }
1020         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
1021         if (gss_auth->service == 0)
1022                 goto err_put_mech;
1023         if (!gssd_running(gss_auth->net))
1024                 goto err_put_mech;
1025         auth = &gss_auth->rpc_auth;
1026         auth->au_cslack = GSS_CRED_SLACK >> 2;
1027         auth->au_rslack = GSS_VERF_SLACK >> 2;
1028         auth->au_flags = 0;
1029         auth->au_ops = &authgss_ops;
1030         auth->au_flavor = flavor;
1031         if (gss_pseudoflavor_to_datatouch(gss_auth->mech, flavor))
1032                 auth->au_flags |= RPCAUTH_AUTH_DATATOUCH;
1033         atomic_set(&auth->au_count, 1);
1034         kref_init(&gss_auth->kref);
1035
1036         err = rpcauth_init_credcache(auth);
1037         if (err)
1038                 goto err_put_mech;
1039         /*
1040          * Note: if we created the old pipe first, then someone who
1041          * examined the directory at the right moment might conclude
1042          * that we supported only the old pipe.  So we instead create
1043          * the new pipe first.
1044          */
1045         gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
1046         if (IS_ERR(gss_pipe)) {
1047                 err = PTR_ERR(gss_pipe);
1048                 goto err_destroy_credcache;
1049         }
1050         gss_auth->gss_pipe[1] = gss_pipe;
1051
1052         gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
1053                         &gss_upcall_ops_v0);
1054         if (IS_ERR(gss_pipe)) {
1055                 err = PTR_ERR(gss_pipe);
1056                 goto err_destroy_pipe_1;
1057         }
1058         gss_auth->gss_pipe[0] = gss_pipe;
1059
1060         return gss_auth;
1061 err_destroy_pipe_1:
1062         gss_pipe_free(gss_auth->gss_pipe[1]);
1063 err_destroy_credcache:
1064         rpcauth_destroy_credcache(auth);
1065 err_put_mech:
1066         gss_mech_put(gss_auth->mech);
1067 err_put_net:
1068         put_net(gss_auth->net);
1069 err_free:
1070         kfree(gss_auth->target_name);
1071         kfree(gss_auth);
1072 out_dec:
1073         module_put(THIS_MODULE);
1074         return ERR_PTR(err);
1075 }
1076
1077 static void
1078 gss_free(struct gss_auth *gss_auth)
1079 {
1080         gss_pipe_free(gss_auth->gss_pipe[0]);
1081         gss_pipe_free(gss_auth->gss_pipe[1]);
1082         gss_mech_put(gss_auth->mech);
1083         put_net(gss_auth->net);
1084         kfree(gss_auth->target_name);
1085
1086         kfree(gss_auth);
1087         module_put(THIS_MODULE);
1088 }
1089
1090 static void
1091 gss_free_callback(struct kref *kref)
1092 {
1093         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1094
1095         gss_free(gss_auth);
1096 }
1097
1098 static void
1099 gss_put_auth(struct gss_auth *gss_auth)
1100 {
1101         kref_put(&gss_auth->kref, gss_free_callback);
1102 }
1103
1104 static void
1105 gss_destroy(struct rpc_auth *auth)
1106 {
1107         struct gss_auth *gss_auth = container_of(auth,
1108                         struct gss_auth, rpc_auth);
1109
1110         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
1111                         auth, auth->au_flavor);
1112
1113         if (hash_hashed(&gss_auth->hash)) {
1114                 spin_lock(&gss_auth_hash_lock);
1115                 hash_del(&gss_auth->hash);
1116                 spin_unlock(&gss_auth_hash_lock);
1117         }
1118
1119         gss_pipe_free(gss_auth->gss_pipe[0]);
1120         gss_auth->gss_pipe[0] = NULL;
1121         gss_pipe_free(gss_auth->gss_pipe[1]);
1122         gss_auth->gss_pipe[1] = NULL;
1123         rpcauth_destroy_credcache(auth);
1124
1125         gss_put_auth(gss_auth);
1126 }
1127
1128 /*
1129  * Auths may be shared between rpc clients that were cloned from a
1130  * common client with the same xprt, if they also share the flavor and
1131  * target_name.
1132  *
1133  * The auth is looked up from the oldest parent sharing the same
1134  * cl_xprt, and the auth itself references only that common parent
1135  * (which is guaranteed to last as long as any of its descendants).
1136  */
1137 static struct gss_auth *
1138 gss_auth_find_or_add_hashed(const struct rpc_auth_create_args *args,
1139                 struct rpc_clnt *clnt,
1140                 struct gss_auth *new)
1141 {
1142         struct gss_auth *gss_auth;
1143         unsigned long hashval = (unsigned long)clnt;
1144
1145         spin_lock(&gss_auth_hash_lock);
1146         hash_for_each_possible(gss_auth_hash_table,
1147                         gss_auth,
1148                         hash,
1149                         hashval) {
1150                 if (gss_auth->client != clnt)
1151                         continue;
1152                 if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1153                         continue;
1154                 if (gss_auth->target_name != args->target_name) {
1155                         if (gss_auth->target_name == NULL)
1156                                 continue;
1157                         if (args->target_name == NULL)
1158                                 continue;
1159                         if (strcmp(gss_auth->target_name, args->target_name))
1160                                 continue;
1161                 }
1162                 if (!atomic_inc_not_zero(&gss_auth->rpc_auth.au_count))
1163                         continue;
1164                 goto out;
1165         }
1166         if (new)
1167                 hash_add(gss_auth_hash_table, &new->hash, hashval);
1168         gss_auth = new;
1169 out:
1170         spin_unlock(&gss_auth_hash_lock);
1171         return gss_auth;
1172 }
1173
1174 static struct gss_auth *
1175 gss_create_hashed(const struct rpc_auth_create_args *args,
1176                   struct rpc_clnt *clnt)
1177 {
1178         struct gss_auth *gss_auth;
1179         struct gss_auth *new;
1180
1181         gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1182         if (gss_auth != NULL)
1183                 goto out;
1184         new = gss_create_new(args, clnt);
1185         if (IS_ERR(new))
1186                 return new;
1187         gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1188         if (gss_auth != new)
1189                 gss_destroy(&new->rpc_auth);
1190 out:
1191         return gss_auth;
1192 }
1193
1194 static struct rpc_auth *
1195 gss_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1196 {
1197         struct gss_auth *gss_auth;
1198         struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
1199
1200         while (clnt != clnt->cl_parent) {
1201                 struct rpc_clnt *parent = clnt->cl_parent;
1202                 /* Find the original parent for this transport */
1203                 if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
1204                         break;
1205                 clnt = parent;
1206         }
1207
1208         gss_auth = gss_create_hashed(args, clnt);
1209         if (IS_ERR(gss_auth))
1210                 return ERR_CAST(gss_auth);
1211         return &gss_auth->rpc_auth;
1212 }
1213
1214 /*
1215  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
1216  * to the server with the GSS control procedure field set to
1217  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1218  * all RPCSEC_GSS state associated with that context.
1219  */
1220 static int
1221 gss_destroying_context(struct rpc_cred *cred)
1222 {
1223         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1224         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1225         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1226         struct rpc_task *task;
1227
1228         if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
1229                 return 0;
1230
1231         ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1232         cred->cr_ops = &gss_nullops;
1233
1234         /* Take a reference to ensure the cred will be destroyed either
1235          * by the RPC call or by the put_rpccred() below */
1236         get_rpccred(cred);
1237
1238         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
1239         if (!IS_ERR(task))
1240                 rpc_put_task(task);
1241
1242         put_rpccred(cred);
1243         return 1;
1244 }
1245
1246 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1247  * to create a new cred or context, so they check that things have been
1248  * allocated before freeing them. */
1249 static void
1250 gss_do_free_ctx(struct gss_cl_ctx *ctx)
1251 {
1252         dprintk("RPC:       %s\n", __func__);
1253
1254         gss_delete_sec_context(&ctx->gc_gss_ctx);
1255         kfree(ctx->gc_wire_ctx.data);
1256         kfree(ctx->gc_acceptor.data);
1257         kfree(ctx);
1258 }
1259
1260 static void
1261 gss_free_ctx_callback(struct rcu_head *head)
1262 {
1263         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1264         gss_do_free_ctx(ctx);
1265 }
1266
1267 static void
1268 gss_free_ctx(struct gss_cl_ctx *ctx)
1269 {
1270         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1271 }
1272
1273 static void
1274 gss_free_cred(struct gss_cred *gss_cred)
1275 {
1276         dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1277         kfree(gss_cred);
1278 }
1279
1280 static void
1281 gss_free_cred_callback(struct rcu_head *head)
1282 {
1283         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1284         gss_free_cred(gss_cred);
1285 }
1286
1287 static void
1288 gss_destroy_nullcred(struct rpc_cred *cred)
1289 {
1290         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1291         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1292         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1293
1294         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1295         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1296         if (ctx)
1297                 gss_put_ctx(ctx);
1298         gss_put_auth(gss_auth);
1299 }
1300
1301 static void
1302 gss_destroy_cred(struct rpc_cred *cred)
1303 {
1304
1305         if (gss_destroying_context(cred))
1306                 return;
1307         gss_destroy_nullcred(cred);
1308 }
1309
1310 static int
1311 gss_hash_cred(struct auth_cred *acred, unsigned int hashbits)
1312 {
1313         return hash_64(from_kuid(&init_user_ns, acred->uid), hashbits);
1314 }
1315
1316 /*
1317  * Lookup RPCSEC_GSS cred for the current process
1318  */
1319 static struct rpc_cred *
1320 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1321 {
1322         return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS);
1323 }
1324
1325 static struct rpc_cred *
1326 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp)
1327 {
1328         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1329         struct gss_cred *cred = NULL;
1330         int err = -ENOMEM;
1331
1332         dprintk("RPC:       %s for uid %d, flavor %d\n",
1333                 __func__, from_kuid(&init_user_ns, acred->uid),
1334                 auth->au_flavor);
1335
1336         if (!(cred = kzalloc(sizeof(*cred), gfp)))
1337                 goto out_err;
1338
1339         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1340         /*
1341          * Note: in order to force a call to call_refresh(), we deliberately
1342          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1343          */
1344         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1345         cred->gc_service = gss_auth->service;
1346         cred->gc_principal = NULL;
1347         if (acred->machine_cred)
1348                 cred->gc_principal = acred->principal;
1349         kref_get(&gss_auth->kref);
1350         return &cred->gc_base;
1351
1352 out_err:
1353         dprintk("RPC:       %s failed with error %d\n", __func__, err);
1354         return ERR_PTR(err);
1355 }
1356
1357 static int
1358 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1359 {
1360         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1361         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1362         int err;
1363
1364         do {
1365                 err = gss_create_upcall(gss_auth, gss_cred);
1366         } while (err == -EAGAIN);
1367         return err;
1368 }
1369
1370 static char *
1371 gss_stringify_acceptor(struct rpc_cred *cred)
1372 {
1373         char *string = NULL;
1374         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1375         struct gss_cl_ctx *ctx;
1376         unsigned int len;
1377         struct xdr_netobj *acceptor;
1378
1379         rcu_read_lock();
1380         ctx = rcu_dereference(gss_cred->gc_ctx);
1381         if (!ctx)
1382                 goto out;
1383
1384         len = ctx->gc_acceptor.len;
1385         rcu_read_unlock();
1386
1387         /* no point if there's no string */
1388         if (!len)
1389                 return NULL;
1390 realloc:
1391         string = kmalloc(len + 1, GFP_KERNEL);
1392         if (!string)
1393                 return NULL;
1394
1395         rcu_read_lock();
1396         ctx = rcu_dereference(gss_cred->gc_ctx);
1397
1398         /* did the ctx disappear or was it replaced by one with no acceptor? */
1399         if (!ctx || !ctx->gc_acceptor.len) {
1400                 kfree(string);
1401                 string = NULL;
1402                 goto out;
1403         }
1404
1405         acceptor = &ctx->gc_acceptor;
1406
1407         /*
1408          * Did we find a new acceptor that's longer than the original? Allocate
1409          * a longer buffer and try again.
1410          */
1411         if (len < acceptor->len) {
1412                 len = acceptor->len;
1413                 rcu_read_unlock();
1414                 kfree(string);
1415                 goto realloc;
1416         }
1417
1418         memcpy(string, acceptor->data, acceptor->len);
1419         string[acceptor->len] = '\0';
1420 out:
1421         rcu_read_unlock();
1422         return string;
1423 }
1424
1425 /*
1426  * Returns -EACCES if GSS context is NULL or will expire within the
1427  * timeout (miliseconds)
1428  */
1429 static int
1430 gss_key_timeout(struct rpc_cred *rc)
1431 {
1432         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1433         struct gss_cl_ctx *ctx;
1434         unsigned long timeout = jiffies + (gss_key_expire_timeo * HZ);
1435         int ret = 0;
1436
1437         rcu_read_lock();
1438         ctx = rcu_dereference(gss_cred->gc_ctx);
1439         if (!ctx || time_after(timeout, ctx->gc_expiry))
1440                 ret = -EACCES;
1441         rcu_read_unlock();
1442
1443         return ret;
1444 }
1445
1446 static int
1447 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1448 {
1449         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1450         struct gss_cl_ctx *ctx;
1451         int ret;
1452
1453         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1454                 goto out;
1455         /* Don't match with creds that have expired. */
1456         rcu_read_lock();
1457         ctx = rcu_dereference(gss_cred->gc_ctx);
1458         if (!ctx || time_after(jiffies, ctx->gc_expiry)) {
1459                 rcu_read_unlock();
1460                 return 0;
1461         }
1462         rcu_read_unlock();
1463         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1464                 return 0;
1465 out:
1466         if (acred->principal != NULL) {
1467                 if (gss_cred->gc_principal == NULL)
1468                         return 0;
1469                 ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1470                 goto check_expire;
1471         }
1472         if (gss_cred->gc_principal != NULL)
1473                 return 0;
1474         ret = uid_eq(rc->cr_uid, acred->uid);
1475
1476 check_expire:
1477         if (ret == 0)
1478                 return ret;
1479
1480         /* Notify acred users of GSS context expiration timeout */
1481         if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags) &&
1482             (gss_key_timeout(rc) != 0)) {
1483                 /* test will now be done from generic cred */
1484                 test_and_clear_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
1485                 /* tell NFS layer that key will expire soon */
1486                 set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
1487         }
1488         return ret;
1489 }
1490
1491 /*
1492 * Marshal credentials.
1493 * Maybe we should keep a cached credential for performance reasons.
1494 */
1495 static __be32 *
1496 gss_marshal(struct rpc_task *task, __be32 *p)
1497 {
1498         struct rpc_rqst *req = task->tk_rqstp;
1499         struct rpc_cred *cred = req->rq_cred;
1500         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1501                                                  gc_base);
1502         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1503         __be32          *cred_len;
1504         u32             maj_stat = 0;
1505         struct xdr_netobj mic;
1506         struct kvec     iov;
1507         struct xdr_buf  verf_buf;
1508
1509         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1510
1511         *p++ = htonl(RPC_AUTH_GSS);
1512         cred_len = p++;
1513
1514         spin_lock(&ctx->gc_seq_lock);
1515         req->rq_seqno = ctx->gc_seq++;
1516         spin_unlock(&ctx->gc_seq_lock);
1517
1518         *p++ = htonl((u32) RPC_GSS_VERSION);
1519         *p++ = htonl((u32) ctx->gc_proc);
1520         *p++ = htonl((u32) req->rq_seqno);
1521         *p++ = htonl((u32) gss_cred->gc_service);
1522         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1523         *cred_len = htonl((p - (cred_len + 1)) << 2);
1524
1525         /* We compute the checksum for the verifier over the xdr-encoded bytes
1526          * starting with the xid and ending at the end of the credential: */
1527         iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
1528                                         req->rq_snd_buf.head[0].iov_base);
1529         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1530         xdr_buf_from_iov(&iov, &verf_buf);
1531
1532         /* set verifier flavor*/
1533         *p++ = htonl(RPC_AUTH_GSS);
1534
1535         mic.data = (u8 *)(p + 1);
1536         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1537         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1538                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1539         } else if (maj_stat != 0) {
1540                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1541                 goto out_put_ctx;
1542         }
1543         p = xdr_encode_opaque(p, NULL, mic.len);
1544         gss_put_ctx(ctx);
1545         return p;
1546 out_put_ctx:
1547         gss_put_ctx(ctx);
1548         return NULL;
1549 }
1550
1551 static int gss_renew_cred(struct rpc_task *task)
1552 {
1553         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1554         struct gss_cred *gss_cred = container_of(oldcred,
1555                                                  struct gss_cred,
1556                                                  gc_base);
1557         struct rpc_auth *auth = oldcred->cr_auth;
1558         struct auth_cred acred = {
1559                 .uid = oldcred->cr_uid,
1560                 .principal = gss_cred->gc_principal,
1561                 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
1562         };
1563         struct rpc_cred *new;
1564
1565         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1566         if (IS_ERR(new))
1567                 return PTR_ERR(new);
1568         task->tk_rqstp->rq_cred = new;
1569         put_rpccred(oldcred);
1570         return 0;
1571 }
1572
1573 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1574 {
1575         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1576                 unsigned long now = jiffies;
1577                 unsigned long begin, expire;
1578                 struct gss_cred *gss_cred;
1579
1580                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1581                 begin = gss_cred->gc_upcall_timestamp;
1582                 expire = begin + gss_expired_cred_retry_delay * HZ;
1583
1584                 if (time_in_range_open(now, begin, expire))
1585                         return 1;
1586         }
1587         return 0;
1588 }
1589
1590 /*
1591 * Refresh credentials. XXX - finish
1592 */
1593 static int
1594 gss_refresh(struct rpc_task *task)
1595 {
1596         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1597         int ret = 0;
1598
1599         if (gss_cred_is_negative_entry(cred))
1600                 return -EKEYEXPIRED;
1601
1602         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1603                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1604                 ret = gss_renew_cred(task);
1605                 if (ret < 0)
1606                         goto out;
1607                 cred = task->tk_rqstp->rq_cred;
1608         }
1609
1610         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1611                 ret = gss_refresh_upcall(task);
1612 out:
1613         return ret;
1614 }
1615
1616 /* Dummy refresh routine: used only when destroying the context */
1617 static int
1618 gss_refresh_null(struct rpc_task *task)
1619 {
1620         return 0;
1621 }
1622
1623 static __be32 *
1624 gss_validate(struct rpc_task *task, __be32 *p)
1625 {
1626         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1627         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1628         __be32          *seq = NULL;
1629         struct kvec     iov;
1630         struct xdr_buf  verf_buf;
1631         struct xdr_netobj mic;
1632         u32             flav,len;
1633         u32             maj_stat;
1634         __be32          *ret = ERR_PTR(-EIO);
1635
1636         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1637
1638         flav = ntohl(*p++);
1639         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1640                 goto out_bad;
1641         if (flav != RPC_AUTH_GSS)
1642                 goto out_bad;
1643         seq = kmalloc(4, GFP_NOFS);
1644         if (!seq)
1645                 goto out_bad;
1646         *seq = htonl(task->tk_rqstp->rq_seqno);
1647         iov.iov_base = seq;
1648         iov.iov_len = 4;
1649         xdr_buf_from_iov(&iov, &verf_buf);
1650         mic.data = (u8 *)p;
1651         mic.len = len;
1652
1653         ret = ERR_PTR(-EACCES);
1654         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1655         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1656                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1657         if (maj_stat) {
1658                 dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1659                         task->tk_pid, __func__, maj_stat);
1660                 goto out_bad;
1661         }
1662         /* We leave it to unwrap to calculate au_rslack. For now we just
1663          * calculate the length of the verifier: */
1664         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1665         gss_put_ctx(ctx);
1666         dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1667                         task->tk_pid, __func__);
1668         kfree(seq);
1669         return p + XDR_QUADLEN(len);
1670 out_bad:
1671         gss_put_ctx(ctx);
1672         dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
1673                 PTR_ERR(ret));
1674         kfree(seq);
1675         return ret;
1676 }
1677
1678 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1679                                 __be32 *p, void *obj)
1680 {
1681         struct xdr_stream xdr;
1682
1683         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1684         encode(rqstp, &xdr, obj);
1685 }
1686
1687 static inline int
1688 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1689                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1690                    __be32 *p, void *obj)
1691 {
1692         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1693         struct xdr_buf  integ_buf;
1694         __be32          *integ_len = NULL;
1695         struct xdr_netobj mic;
1696         u32             offset;
1697         __be32          *q;
1698         struct kvec     *iov;
1699         u32             maj_stat = 0;
1700         int             status = -EIO;
1701
1702         integ_len = p++;
1703         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1704         *p++ = htonl(rqstp->rq_seqno);
1705
1706         gss_wrap_req_encode(encode, rqstp, p, obj);
1707
1708         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1709                                 offset, snd_buf->len - offset))
1710                 return status;
1711         *integ_len = htonl(integ_buf.len);
1712
1713         /* guess whether we're in the head or the tail: */
1714         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1715                 iov = snd_buf->tail;
1716         else
1717                 iov = snd_buf->head;
1718         p = iov->iov_base + iov->iov_len;
1719         mic.data = (u8 *)(p + 1);
1720
1721         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1722         status = -EIO; /* XXX? */
1723         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1724                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1725         else if (maj_stat)
1726                 return status;
1727         q = xdr_encode_opaque(p, NULL, mic.len);
1728
1729         offset = (u8 *)q - (u8 *)p;
1730         iov->iov_len += offset;
1731         snd_buf->len += offset;
1732         return 0;
1733 }
1734
1735 static void
1736 priv_release_snd_buf(struct rpc_rqst *rqstp)
1737 {
1738         int i;
1739
1740         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1741                 __free_page(rqstp->rq_enc_pages[i]);
1742         kfree(rqstp->rq_enc_pages);
1743         rqstp->rq_release_snd_buf = NULL;
1744 }
1745
1746 static int
1747 alloc_enc_pages(struct rpc_rqst *rqstp)
1748 {
1749         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1750         int first, last, i;
1751
1752         if (rqstp->rq_release_snd_buf)
1753                 rqstp->rq_release_snd_buf(rqstp);
1754
1755         if (snd_buf->page_len == 0) {
1756                 rqstp->rq_enc_pages_num = 0;
1757                 return 0;
1758         }
1759
1760         first = snd_buf->page_base >> PAGE_SHIFT;
1761         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_SHIFT;
1762         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1763         rqstp->rq_enc_pages
1764                 = kmalloc_array(rqstp->rq_enc_pages_num,
1765                                 sizeof(struct page *),
1766                                 GFP_NOFS);
1767         if (!rqstp->rq_enc_pages)
1768                 goto out;
1769         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1770                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1771                 if (rqstp->rq_enc_pages[i] == NULL)
1772                         goto out_free;
1773         }
1774         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1775         return 0;
1776 out_free:
1777         rqstp->rq_enc_pages_num = i;
1778         priv_release_snd_buf(rqstp);
1779 out:
1780         return -EAGAIN;
1781 }
1782
1783 static inline int
1784 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1785                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1786                   __be32 *p, void *obj)
1787 {
1788         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1789         u32             offset;
1790         u32             maj_stat;
1791         int             status;
1792         __be32          *opaque_len;
1793         struct page     **inpages;
1794         int             first;
1795         int             pad;
1796         struct kvec     *iov;
1797         char            *tmp;
1798
1799         opaque_len = p++;
1800         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1801         *p++ = htonl(rqstp->rq_seqno);
1802
1803         gss_wrap_req_encode(encode, rqstp, p, obj);
1804
1805         status = alloc_enc_pages(rqstp);
1806         if (status)
1807                 return status;
1808         first = snd_buf->page_base >> PAGE_SHIFT;
1809         inpages = snd_buf->pages + first;
1810         snd_buf->pages = rqstp->rq_enc_pages;
1811         snd_buf->page_base -= first << PAGE_SHIFT;
1812         /*
1813          * Give the tail its own page, in case we need extra space in the
1814          * head when wrapping:
1815          *
1816          * call_allocate() allocates twice the slack space required
1817          * by the authentication flavor to rq_callsize.
1818          * For GSS, slack is GSS_CRED_SLACK.
1819          */
1820         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1821                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1822                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1823                 snd_buf->tail[0].iov_base = tmp;
1824         }
1825         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1826         /* slack space should prevent this ever happening: */
1827         BUG_ON(snd_buf->len > snd_buf->buflen);
1828         status = -EIO;
1829         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1830          * done anyway, so it's safe to put the request on the wire: */
1831         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1832                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1833         else if (maj_stat)
1834                 return status;
1835
1836         *opaque_len = htonl(snd_buf->len - offset);
1837         /* guess whether we're in the head or the tail: */
1838         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1839                 iov = snd_buf->tail;
1840         else
1841                 iov = snd_buf->head;
1842         p = iov->iov_base + iov->iov_len;
1843         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1844         memset(p, 0, pad);
1845         iov->iov_len += pad;
1846         snd_buf->len += pad;
1847
1848         return 0;
1849 }
1850
1851 static int
1852 gss_wrap_req(struct rpc_task *task,
1853              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1854 {
1855         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1856         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1857                         gc_base);
1858         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1859         int             status = -EIO;
1860
1861         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1862         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1863                 /* The spec seems a little ambiguous here, but I think that not
1864                  * wrapping context destruction requests makes the most sense.
1865                  */
1866                 gss_wrap_req_encode(encode, rqstp, p, obj);
1867                 status = 0;
1868                 goto out;
1869         }
1870         switch (gss_cred->gc_service) {
1871         case RPC_GSS_SVC_NONE:
1872                 gss_wrap_req_encode(encode, rqstp, p, obj);
1873                 status = 0;
1874                 break;
1875         case RPC_GSS_SVC_INTEGRITY:
1876                 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1877                 break;
1878         case RPC_GSS_SVC_PRIVACY:
1879                 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1880                 break;
1881         }
1882 out:
1883         gss_put_ctx(ctx);
1884         dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1885         return status;
1886 }
1887
1888 static inline int
1889 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1890                 struct rpc_rqst *rqstp, __be32 **p)
1891 {
1892         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1893         struct xdr_buf integ_buf;
1894         struct xdr_netobj mic;
1895         u32 data_offset, mic_offset;
1896         u32 integ_len;
1897         u32 maj_stat;
1898         int status = -EIO;
1899
1900         integ_len = ntohl(*(*p)++);
1901         if (integ_len & 3)
1902                 return status;
1903         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1904         mic_offset = integ_len + data_offset;
1905         if (mic_offset > rcv_buf->len)
1906                 return status;
1907         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1908                 return status;
1909
1910         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1911                                 mic_offset - data_offset))
1912                 return status;
1913
1914         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1915                 return status;
1916
1917         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1918         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1919                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1920         if (maj_stat != GSS_S_COMPLETE)
1921                 return status;
1922         return 0;
1923 }
1924
1925 static inline int
1926 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1927                 struct rpc_rqst *rqstp, __be32 **p)
1928 {
1929         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1930         u32 offset;
1931         u32 opaque_len;
1932         u32 maj_stat;
1933         int status = -EIO;
1934
1935         opaque_len = ntohl(*(*p)++);
1936         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1937         if (offset + opaque_len > rcv_buf->len)
1938                 return status;
1939         /* remove padding: */
1940         rcv_buf->len = offset + opaque_len;
1941
1942         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1943         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1944                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1945         if (maj_stat != GSS_S_COMPLETE)
1946                 return status;
1947         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1948                 return status;
1949
1950         return 0;
1951 }
1952
1953 static int
1954 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1955                       __be32 *p, void *obj)
1956 {
1957         struct xdr_stream xdr;
1958
1959         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1960         return decode(rqstp, &xdr, obj);
1961 }
1962
1963 static int
1964 gss_unwrap_resp(struct rpc_task *task,
1965                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1966 {
1967         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1968         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1969                         gc_base);
1970         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1971         __be32          *savedp = p;
1972         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1973         int             savedlen = head->iov_len;
1974         int             status = -EIO;
1975
1976         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1977                 goto out_decode;
1978         switch (gss_cred->gc_service) {
1979         case RPC_GSS_SVC_NONE:
1980                 break;
1981         case RPC_GSS_SVC_INTEGRITY:
1982                 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1983                 if (status)
1984                         goto out;
1985                 break;
1986         case RPC_GSS_SVC_PRIVACY:
1987                 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1988                 if (status)
1989                         goto out;
1990                 break;
1991         }
1992         /* take into account extra slack for integrity and privacy cases: */
1993         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1994                                                 + (savedlen - head->iov_len);
1995 out_decode:
1996         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
1997 out:
1998         gss_put_ctx(ctx);
1999         dprintk("RPC: %5u %s returning %d\n",
2000                 task->tk_pid, __func__, status);
2001         return status;
2002 }
2003
2004 static const struct rpc_authops authgss_ops = {
2005         .owner          = THIS_MODULE,
2006         .au_flavor      = RPC_AUTH_GSS,
2007         .au_name        = "RPCSEC_GSS",
2008         .create         = gss_create,
2009         .destroy        = gss_destroy,
2010         .hash_cred      = gss_hash_cred,
2011         .lookup_cred    = gss_lookup_cred,
2012         .crcreate       = gss_create_cred,
2013         .list_pseudoflavors = gss_mech_list_pseudoflavors,
2014         .info2flavor    = gss_mech_info2flavor,
2015         .flavor2info    = gss_mech_flavor2info,
2016 };
2017
2018 static const struct rpc_credops gss_credops = {
2019         .cr_name                = "AUTH_GSS",
2020         .crdestroy              = gss_destroy_cred,
2021         .cr_init                = gss_cred_init,
2022         .crbind                 = rpcauth_generic_bind_cred,
2023         .crmatch                = gss_match,
2024         .crmarshal              = gss_marshal,
2025         .crrefresh              = gss_refresh,
2026         .crvalidate             = gss_validate,
2027         .crwrap_req             = gss_wrap_req,
2028         .crunwrap_resp          = gss_unwrap_resp,
2029         .crkey_timeout          = gss_key_timeout,
2030         .crstringify_acceptor   = gss_stringify_acceptor,
2031 };
2032
2033 static const struct rpc_credops gss_nullops = {
2034         .cr_name                = "AUTH_GSS",
2035         .crdestroy              = gss_destroy_nullcred,
2036         .crbind                 = rpcauth_generic_bind_cred,
2037         .crmatch                = gss_match,
2038         .crmarshal              = gss_marshal,
2039         .crrefresh              = gss_refresh_null,
2040         .crvalidate             = gss_validate,
2041         .crwrap_req             = gss_wrap_req,
2042         .crunwrap_resp          = gss_unwrap_resp,
2043         .crstringify_acceptor   = gss_stringify_acceptor,
2044 };
2045
2046 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
2047         .upcall         = rpc_pipe_generic_upcall,
2048         .downcall       = gss_pipe_downcall,
2049         .destroy_msg    = gss_pipe_destroy_msg,
2050         .open_pipe      = gss_pipe_open_v0,
2051         .release_pipe   = gss_pipe_release,
2052 };
2053
2054 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
2055         .upcall         = rpc_pipe_generic_upcall,
2056         .downcall       = gss_pipe_downcall,
2057         .destroy_msg    = gss_pipe_destroy_msg,
2058         .open_pipe      = gss_pipe_open_v1,
2059         .release_pipe   = gss_pipe_release,
2060 };
2061
2062 static __net_init int rpcsec_gss_init_net(struct net *net)
2063 {
2064         return gss_svc_init_net(net);
2065 }
2066
2067 static __net_exit void rpcsec_gss_exit_net(struct net *net)
2068 {
2069         gss_svc_shutdown_net(net);
2070 }
2071
2072 static struct pernet_operations rpcsec_gss_net_ops = {
2073         .init = rpcsec_gss_init_net,
2074         .exit = rpcsec_gss_exit_net,
2075 };
2076
2077 /*
2078  * Initialize RPCSEC_GSS module
2079  */
2080 static int __init init_rpcsec_gss(void)
2081 {
2082         int err = 0;
2083
2084         err = rpcauth_register(&authgss_ops);
2085         if (err)
2086                 goto out;
2087         err = gss_svc_init();
2088         if (err)
2089                 goto out_unregister;
2090         err = register_pernet_subsys(&rpcsec_gss_net_ops);
2091         if (err)
2092                 goto out_svc_exit;
2093         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
2094         return 0;
2095 out_svc_exit:
2096         gss_svc_shutdown();
2097 out_unregister:
2098         rpcauth_unregister(&authgss_ops);
2099 out:
2100         return err;
2101 }
2102
2103 static void __exit exit_rpcsec_gss(void)
2104 {
2105         unregister_pernet_subsys(&rpcsec_gss_net_ops);
2106         gss_svc_shutdown();
2107         rpcauth_unregister(&authgss_ops);
2108         rcu_barrier(); /* Wait for completion of call_rcu()'s */
2109 }
2110
2111 MODULE_ALIAS("rpc-auth-6");
2112 MODULE_LICENSE("GPL");
2113 module_param_named(expired_cred_retry_delay,
2114                    gss_expired_cred_retry_delay,
2115                    uint, 0644);
2116 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
2117                 "the RPC engine retries an expired credential");
2118
2119 module_param_named(key_expire_timeo,
2120                    gss_key_expire_timeo,
2121                    uint, 0644);
2122 MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
2123                 "credential keys lifetime where the NFS layer cleans up "
2124                 "prior to key expiration");
2125
2126 module_init(init_rpcsec_gss)
2127 module_exit(exit_rpcsec_gss)