net/sunrpc/auth_gss/auth_gss.c

   1 /*
   2  * linux/net/sunrpc/auth_gss/auth_gss.c
   3  *
   4  * RPCSEC_GSS client authentication.
   5  *
   6  *  Copyright (c) 2000 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Dug Song       <dugsong@monkey.org>
  10  *  Andy Adamson   <andros@umich.edu>
  11  *
  12  *  Redistribution and use in source and binary forms, with or without
  13  *  modification, are permitted provided that the following conditions
  14  *  are met:
  15  *
  16  *  1. Redistributions of source code must retain the above copyright
  17  *     notice, this list of conditions and the following disclaimer.
  18  *  2. Redistributions in binary form must reproduce the above copyright
  19  *     notice, this list of conditions and the following disclaimer in the
  20  *     documentation and/or other materials provided with the distribution.
  21  *  3. Neither the name of the University nor the names of its
  22  *     contributors may be used to endorse or promote products derived
  23  *     from this software without specific prior written permission.
  24  *
  25  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  26  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  27  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  28  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  32  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  33  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  34  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  35  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38
  39 #include <linux/module.h>
  40 #include <linux/init.h>
  41 #include <linux/types.h>
  42 #include <linux/slab.h>
  43 #include <linux/sched.h>
  44 #include <linux/pagemap.h>
  45 #include <linux/sunrpc/clnt.h>
  46 #include <linux/sunrpc/auth.h>
  47 #include <linux/sunrpc/auth_gss.h>
  48 #include <linux/sunrpc/svcauth_gss.h>
  49 #include <linux/sunrpc/gss_err.h>
  50 #include <linux/workqueue.h>
  51 #include <linux/sunrpc/rpc_pipe_fs.h>
  52 #include <linux/sunrpc/gss_api.h>
  53 #include <asm/uaccess.h>
  54 #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         atomic_inc(&ctx->count);
 122         return ctx;
 123 }
 124
 125 static inline void
 126 gss_put_ctx(struct gss_cl_ctx *ctx)
 127 {
 128         if (atomic_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                 atomic_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 #define UPCALL_BUF_LEN 128
 260
 261 struct gss_upcall_msg {
 262         atomic_t count;
 263         kuid_t  uid;
 264         struct rpc_pipe_msg msg;
 265         struct list_head list;
 266         struct gss_auth *auth;
 267         struct rpc_pipe *pipe;
 268         struct rpc_wait_queue rpc_waitqueue;
 269         wait_queue_head_t waitqueue;
 270         struct gss_cl_ctx *ctx;
 271         char databuf[UPCALL_BUF_LEN];
 272 };
 273
 274 static int get_pipe_version(struct net *net)
 275 {
 276         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 277         int ret;
 278
 279         spin_lock(&pipe_version_lock);
 280         if (sn->pipe_version >= 0) {
 281                 atomic_inc(&sn->pipe_users);
 282                 ret = sn->pipe_version;
 283         } else
 284                 ret = -EAGAIN;
 285         spin_unlock(&pipe_version_lock);
 286         return ret;
 287 }
 288
 289 static void put_pipe_version(struct net *net)
 290 {
 291         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 292
 293         if (atomic_dec_and_lock(&sn->pipe_users, &pipe_version_lock)) {
 294                 sn->pipe_version = -1;
 295                 spin_unlock(&pipe_version_lock);
 296         }
 297 }
 298
 299 static void
 300 gss_release_msg(struct gss_upcall_msg *gss_msg)
 301 {
 302         struct net *net = gss_msg->auth->net;
 303         if (!atomic_dec_and_test(&gss_msg->count))
 304                 return;
 305         put_pipe_version(net);
 306         BUG_ON(!list_empty(&gss_msg->list));
 307         if (gss_msg->ctx != NULL)
 308                 gss_put_ctx(gss_msg->ctx);
 309         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 310         gss_put_auth(gss_msg->auth);
 311         kfree(gss_msg);
 312 }
 313
 314 static struct gss_upcall_msg *
 315 __gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid, const struct gss_auth *auth)
 316 {
 317         struct gss_upcall_msg *pos;
 318         list_for_each_entry(pos, &pipe->in_downcall, list) {
 319                 if (!uid_eq(pos->uid, uid))
 320                         continue;
 321                 if (auth && pos->auth->service != auth->service)
 322                         continue;
 323                 atomic_inc(&pos->count);
 324                 dprintk("RPC:       %s found msg %p\n", __func__, pos);
 325                 return pos;
 326         }
 327         dprintk("RPC:       %s found nothing\n", __func__);
 328         return NULL;
 329 }
 330
 331 /* Try to add an upcall to the pipefs queue.
 332  * If an upcall owned by our uid already exists, then we return a reference
 333  * to that upcall instead of adding the new upcall.
 334  */
 335 static inline struct gss_upcall_msg *
 336 gss_add_msg(struct gss_upcall_msg *gss_msg)
 337 {
 338         struct rpc_pipe *pipe = gss_msg->pipe;
 339         struct gss_upcall_msg *old;
 340
 341         spin_lock(&pipe->lock);
 342         old = __gss_find_upcall(pipe, gss_msg->uid, gss_msg->auth);
 343         if (old == NULL) {
 344                 atomic_inc(&gss_msg->count);
 345                 list_add(&gss_msg->list, &pipe->in_downcall);
 346         } else
 347                 gss_msg = old;
 348         spin_unlock(&pipe->lock);
 349         return gss_msg;
 350 }
 351
 352 static void
 353 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 354 {
 355         list_del_init(&gss_msg->list);
 356         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 357         wake_up_all(&gss_msg->waitqueue);
 358         atomic_dec(&gss_msg->count);
 359 }
 360
 361 static void
 362 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 363 {
 364         struct rpc_pipe *pipe = gss_msg->pipe;
 365
 366         if (list_empty(&gss_msg->list))
 367                 return;
 368         spin_lock(&pipe->lock);
 369         if (!list_empty(&gss_msg->list))
 370                 __gss_unhash_msg(gss_msg);
 371         spin_unlock(&pipe->lock);
 372 }
 373
 374 static void
 375 gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
 376 {
 377         switch (gss_msg->msg.errno) {
 378         case 0:
 379                 if (gss_msg->ctx == NULL)
 380                         break;
 381                 clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 382                 gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
 383                 break;
 384         case -EKEYEXPIRED:
 385                 set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 386         }
 387         gss_cred->gc_upcall_timestamp = jiffies;
 388         gss_cred->gc_upcall = NULL;
 389         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 390 }
 391
 392 static void
 393 gss_upcall_callback(struct rpc_task *task)
 394 {
 395         struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
 396                         struct gss_cred, gc_base);
 397         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 398         struct rpc_pipe *pipe = gss_msg->pipe;
 399
 400         spin_lock(&pipe->lock);
 401         gss_handle_downcall_result(gss_cred, gss_msg);
 402         spin_unlock(&pipe->lock);
 403         task->tk_status = gss_msg->msg.errno;
 404         gss_release_msg(gss_msg);
 405 }
 406
 407 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
 408 {
 409         uid_t uid = from_kuid(&init_user_ns, gss_msg->uid);
 410         memcpy(gss_msg->databuf, &uid, sizeof(uid));
 411         gss_msg->msg.data = gss_msg->databuf;
 412         gss_msg->msg.len = sizeof(uid);
 413
 414         BUILD_BUG_ON(sizeof(uid) > sizeof(gss_msg->databuf));
 415 }
 416
 417 static int gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
 418                                 const char *service_name,
 419                                 const char *target_name)
 420 {
 421         struct gss_api_mech *mech = gss_msg->auth->mech;
 422         char *p = gss_msg->databuf;
 423         size_t buflen = sizeof(gss_msg->databuf);
 424         int len;
 425
 426         len = scnprintf(p, buflen, "mech=%s uid=%d ", mech->gm_name,
 427                         from_kuid(&init_user_ns, gss_msg->uid));
 428         buflen -= len;
 429         p += len;
 430         gss_msg->msg.len = len;
 431         if (target_name) {
 432                 len = scnprintf(p, buflen, "target=%s ", target_name);
 433                 buflen -= len;
 434                 p += len;
 435                 gss_msg->msg.len += len;
 436         }
 437         if (service_name != NULL) {
 438                 len = scnprintf(p, buflen, "service=%s ", service_name);
 439                 buflen -= len;
 440                 p += len;
 441                 gss_msg->msg.len += len;
 442         }
 443         if (mech->gm_upcall_enctypes) {
 444                 len = scnprintf(p, buflen, "enctypes=%s ",
 445                                 mech->gm_upcall_enctypes);
 446                 buflen -= len;
 447                 p += len;
 448                 gss_msg->msg.len += len;
 449         }
 450         len = scnprintf(p, buflen, "\n");
 451         if (len == 0)
 452                 goto out_overflow;
 453         gss_msg->msg.len += len;
 454
 455         gss_msg->msg.data = gss_msg->databuf;
 456         return 0;
 457 out_overflow:
 458         WARN_ON_ONCE(1);
 459         return -ENOMEM;
 460 }
 461
 462 static struct gss_upcall_msg *
 463 gss_alloc_msg(struct gss_auth *gss_auth,
 464                 kuid_t uid, const char *service_name)
 465 {
 466         struct gss_upcall_msg *gss_msg;
 467         int vers;
 468         int err = -ENOMEM;
 469
 470         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 471         if (gss_msg == NULL)
 472                 goto err;
 473         vers = get_pipe_version(gss_auth->net);
 474         err = vers;
 475         if (err < 0)
 476                 goto err_free_msg;
 477         gss_msg->pipe = gss_auth->gss_pipe[vers]->pipe;
 478         INIT_LIST_HEAD(&gss_msg->list);
 479         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 480         init_waitqueue_head(&gss_msg->waitqueue);
 481         atomic_set(&gss_msg->count, 1);
 482         gss_msg->uid = uid;
 483         gss_msg->auth = gss_auth;
 484         switch (vers) {
 485         case 0:
 486                 gss_encode_v0_msg(gss_msg);
 487                 break;
 488         default:
 489                 err = gss_encode_v1_msg(gss_msg, service_name, gss_auth->target_name);
 490                 if (err)
 491                         goto err_put_pipe_version;
 492         };
 493         kref_get(&gss_auth->kref);
 494         return gss_msg;
 495 err_put_pipe_version:
 496         put_pipe_version(gss_auth->net);
 497 err_free_msg:
 498         kfree(gss_msg);
 499 err:
 500         return ERR_PTR(err);
 501 }
 502
 503 static struct gss_upcall_msg *
 504 gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred)
 505 {
 506         struct gss_cred *gss_cred = container_of(cred,
 507                         struct gss_cred, gc_base);
 508         struct gss_upcall_msg *gss_new, *gss_msg;
 509         kuid_t uid = cred->cr_uid;
 510
 511         gss_new = gss_alloc_msg(gss_auth, uid, gss_cred->gc_principal);
 512         if (IS_ERR(gss_new))
 513                 return gss_new;
 514         gss_msg = gss_add_msg(gss_new);
 515         if (gss_msg == gss_new) {
 516                 int res;
 517                 atomic_inc(&gss_msg->count);
 518                 res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
 519                 if (res) {
 520                         gss_unhash_msg(gss_new);
 521                         atomic_dec(&gss_msg->count);
 522                         gss_release_msg(gss_new);
 523                         gss_msg = ERR_PTR(res);
 524                 }
 525         } else
 526                 gss_release_msg(gss_new);
 527         return gss_msg;
 528 }
 529
 530 static void warn_gssd(void)
 531 {
 532         dprintk("AUTH_GSS upcall failed. Please check user daemon is running.\n");
 533 }
 534
 535 static inline int
 536 gss_refresh_upcall(struct rpc_task *task)
 537 {
 538         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 539         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 540                         struct gss_auth, rpc_auth);
 541         struct gss_cred *gss_cred = container_of(cred,
 542                         struct gss_cred, gc_base);
 543         struct gss_upcall_msg *gss_msg;
 544         struct rpc_pipe *pipe;
 545         int err = 0;
 546
 547         dprintk("RPC: %5u %s for uid %u\n",
 548                 task->tk_pid, __func__, from_kuid(&init_user_ns, cred->cr_uid));
 549         gss_msg = gss_setup_upcall(gss_auth, cred);
 550         if (PTR_ERR(gss_msg) == -EAGAIN) {
 551                 /* XXX: warning on the first, under the assumption we
 552                  * shouldn't normally hit this case on a refresh. */
 553                 warn_gssd();
 554                 task->tk_timeout = 15*HZ;
 555                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
 556                 return -EAGAIN;
 557         }
 558         if (IS_ERR(gss_msg)) {
 559                 err = PTR_ERR(gss_msg);
 560                 goto out;
 561         }
 562         pipe = gss_msg->pipe;
 563         spin_lock(&pipe->lock);
 564         if (gss_cred->gc_upcall != NULL)
 565                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 566         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 567                 task->tk_timeout = 0;
 568                 gss_cred->gc_upcall = gss_msg;
 569                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 570                 atomic_inc(&gss_msg->count);
 571                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 572         } else {
 573                 gss_handle_downcall_result(gss_cred, gss_msg);
 574                 err = gss_msg->msg.errno;
 575         }
 576         spin_unlock(&pipe->lock);
 577         gss_release_msg(gss_msg);
 578 out:
 579         dprintk("RPC: %5u %s for uid %u result %d\n",
 580                 task->tk_pid, __func__,
 581                 from_kuid(&init_user_ns, cred->cr_uid), err);
 582         return err;
 583 }
 584
 585 static inline int
 586 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 587 {
 588         struct net *net = gss_auth->net;
 589         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 590         struct rpc_pipe *pipe;
 591         struct rpc_cred *cred = &gss_cred->gc_base;
 592         struct gss_upcall_msg *gss_msg;
 593         DEFINE_WAIT(wait);
 594         int err;
 595
 596         dprintk("RPC:       %s for uid %u\n",
 597                 __func__, from_kuid(&init_user_ns, cred->cr_uid));
 598 retry:
 599         err = 0;
 600         /* if gssd is down, just skip upcalling altogether */
 601         if (!gssd_running(net)) {
 602                 warn_gssd();
 603                 return -EACCES;
 604         }
 605         gss_msg = gss_setup_upcall(gss_auth, cred);
 606         if (PTR_ERR(gss_msg) == -EAGAIN) {
 607                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
 608                                 sn->pipe_version >= 0, 15 * HZ);
 609                 if (sn->pipe_version < 0) {
 610                         warn_gssd();
 611                         err = -EACCES;
 612                 }
 613                 if (err < 0)
 614                         goto out;
 615                 goto retry;
 616         }
 617         if (IS_ERR(gss_msg)) {
 618                 err = PTR_ERR(gss_msg);
 619                 goto out;
 620         }
 621         pipe = gss_msg->pipe;
 622         for (;;) {
 623                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
 624                 spin_lock(&pipe->lock);
 625                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 626                         break;
 627                 }
 628                 spin_unlock(&pipe->lock);
 629                 if (fatal_signal_pending(current)) {
 630                         err = -ERESTARTSYS;
 631                         goto out_intr;
 632                 }
 633                 schedule();
 634         }
 635         if (gss_msg->ctx)
 636                 gss_cred_set_ctx(cred, gss_msg->ctx);
 637         else
 638                 err = gss_msg->msg.errno;
 639         spin_unlock(&pipe->lock);
 640 out_intr:
 641         finish_wait(&gss_msg->waitqueue, &wait);
 642         gss_release_msg(gss_msg);
 643 out:
 644         dprintk("RPC:       %s for uid %u result %d\n",
 645                 __func__, from_kuid(&init_user_ns, cred->cr_uid), err);
 646         return err;
 647 }
 648
 649 #define MSG_BUF_MAXSIZE 1024
 650
 651 static ssize_t
 652 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 653 {
 654         const void *p, *end;
 655         void *buf;
 656         struct gss_upcall_msg *gss_msg;
 657         struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
 658         struct gss_cl_ctx *ctx;
 659         uid_t id;
 660         kuid_t uid;
 661         ssize_t err = -EFBIG;
 662
 663         if (mlen > MSG_BUF_MAXSIZE)
 664                 goto out;
 665         err = -ENOMEM;
 666         buf = kmalloc(mlen, GFP_NOFS);
 667         if (!buf)
 668                 goto out;
 669
 670         err = -EFAULT;
 671         if (copy_from_user(buf, src, mlen))
 672                 goto err;
 673
 674         end = (const void *)((char *)buf + mlen);
 675         p = simple_get_bytes(buf, end, &id, sizeof(id));
 676         if (IS_ERR(p)) {
 677                 err = PTR_ERR(p);
 678                 goto err;
 679         }
 680
 681         uid = make_kuid(&init_user_ns, id);
 682         if (!uid_valid(uid)) {
 683                 err = -EINVAL;
 684                 goto err;
 685         }
 686
 687         err = -ENOMEM;
 688         ctx = gss_alloc_context();
 689         if (ctx == NULL)
 690                 goto err;
 691
 692         err = -ENOENT;
 693         /* Find a matching upcall */
 694         spin_lock(&pipe->lock);
 695         gss_msg = __gss_find_upcall(pipe, uid, NULL);
 696         if (gss_msg == NULL) {
 697                 spin_unlock(&pipe->lock);
 698                 goto err_put_ctx;
 699         }
 700         list_del_init(&gss_msg->list);
 701         spin_unlock(&pipe->lock);
 702
 703         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 704         if (IS_ERR(p)) {
 705                 err = PTR_ERR(p);
 706                 switch (err) {
 707                 case -EACCES:
 708                 case -EKEYEXPIRED:
 709                         gss_msg->msg.errno = err;
 710                         err = mlen;
 711                         break;
 712                 case -EFAULT:
 713                 case -ENOMEM:
 714                 case -EINVAL:
 715                 case -ENOSYS:
 716                         gss_msg->msg.errno = -EAGAIN;
 717                         break;
 718                 default:
 719                         printk(KERN_CRIT "%s: bad return from "
 720                                 "gss_fill_context: %zd\n", __func__, err);
 721                         BUG();
 722                 }
 723                 goto err_release_msg;
 724         }
 725         gss_msg->ctx = gss_get_ctx(ctx);
 726         err = mlen;
 727
 728 err_release_msg:
 729         spin_lock(&pipe->lock);
 730         __gss_unhash_msg(gss_msg);
 731         spin_unlock(&pipe->lock);
 732         gss_release_msg(gss_msg);
 733 err_put_ctx:
 734         gss_put_ctx(ctx);
 735 err:
 736         kfree(buf);
 737 out:
 738         dprintk("RPC:       %s returning %Zd\n", __func__, err);
 739         return err;
 740 }
 741
 742 static int gss_pipe_open(struct inode *inode, int new_version)
 743 {
 744         struct net *net = inode->i_sb->s_fs_info;
 745         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 746         int ret = 0;
 747
 748         spin_lock(&pipe_version_lock);
 749         if (sn->pipe_version < 0) {
 750                 /* First open of any gss pipe determines the version: */
 751                 sn->pipe_version = new_version;
 752                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 753                 wake_up(&pipe_version_waitqueue);
 754         } else if (sn->pipe_version != new_version) {
 755                 /* Trying to open a pipe of a different version */
 756                 ret = -EBUSY;
 757                 goto out;
 758         }
 759         atomic_inc(&sn->pipe_users);
 760 out:
 761         spin_unlock(&pipe_version_lock);
 762         return ret;
 763
 764 }
 765
 766 static int gss_pipe_open_v0(struct inode *inode)
 767 {
 768         return gss_pipe_open(inode, 0);
 769 }
 770
 771 static int gss_pipe_open_v1(struct inode *inode)
 772 {
 773         return gss_pipe_open(inode, 1);
 774 }
 775
 776 static void
 777 gss_pipe_release(struct inode *inode)
 778 {
 779         struct net *net = inode->i_sb->s_fs_info;
 780         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 781         struct gss_upcall_msg *gss_msg;
 782
 783 restart:
 784         spin_lock(&pipe->lock);
 785         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
 786
 787                 if (!list_empty(&gss_msg->msg.list))
 788                         continue;
 789                 gss_msg->msg.errno = -EPIPE;
 790                 atomic_inc(&gss_msg->count);
 791                 __gss_unhash_msg(gss_msg);
 792                 spin_unlock(&pipe->lock);
 793                 gss_release_msg(gss_msg);
 794                 goto restart;
 795         }
 796         spin_unlock(&pipe->lock);
 797
 798         put_pipe_version(net);
 799 }
 800
 801 static void
 802 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 803 {
 804         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 805
 806         if (msg->errno < 0) {
 807                 dprintk("RPC:       %s releasing msg %p\n",
 808                         __func__, gss_msg);
 809                 atomic_inc(&gss_msg->count);
 810                 gss_unhash_msg(gss_msg);
 811                 if (msg->errno == -ETIMEDOUT)
 812                         warn_gssd();
 813                 gss_release_msg(gss_msg);
 814         }
 815         gss_release_msg(gss_msg);
 816 }
 817
 818 static void gss_pipe_dentry_destroy(struct dentry *dir,
 819                 struct rpc_pipe_dir_object *pdo)
 820 {
 821         struct gss_pipe *gss_pipe = pdo->pdo_data;
 822         struct rpc_pipe *pipe = gss_pipe->pipe;
 823
 824         if (pipe->dentry != NULL) {
 825                 rpc_unlink(pipe->dentry);
 826                 pipe->dentry = NULL;
 827         }
 828 }
 829
 830 static int gss_pipe_dentry_create(struct dentry *dir,
 831                 struct rpc_pipe_dir_object *pdo)
 832 {
 833         struct gss_pipe *p = pdo->pdo_data;
 834         struct dentry *dentry;
 835
 836         dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
 837         if (IS_ERR(dentry))
 838                 return PTR_ERR(dentry);
 839         p->pipe->dentry = dentry;
 840         return 0;
 841 }
 842
 843 static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
 844         .create = gss_pipe_dentry_create,
 845         .destroy = gss_pipe_dentry_destroy,
 846 };
 847
 848 static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
 849                 const char *name,
 850                 const struct rpc_pipe_ops *upcall_ops)
 851 {
 852         struct gss_pipe *p;
 853         int err = -ENOMEM;
 854
 855         p = kmalloc(sizeof(*p), GFP_KERNEL);
 856         if (p == NULL)
 857                 goto err;
 858         p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 859         if (IS_ERR(p->pipe)) {
 860                 err = PTR_ERR(p->pipe);
 861                 goto err_free_gss_pipe;
 862         }
 863         p->name = name;
 864         p->clnt = clnt;
 865         kref_init(&p->kref);
 866         rpc_init_pipe_dir_object(&p->pdo,
 867                         &gss_pipe_dir_object_ops,
 868                         p);
 869         return p;
 870 err_free_gss_pipe:
 871         kfree(p);
 872 err:
 873         return ERR_PTR(err);
 874 }
 875
 876 struct gss_alloc_pdo {
 877         struct rpc_clnt *clnt;
 878         const char *name;
 879         const struct rpc_pipe_ops *upcall_ops;
 880 };
 881
 882 static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
 883 {
 884         struct gss_pipe *gss_pipe;
 885         struct gss_alloc_pdo *args = data;
 886
 887         if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
 888                 return 0;
 889         gss_pipe = container_of(pdo, struct gss_pipe, pdo);
 890         if (strcmp(gss_pipe->name, args->name) != 0)
 891                 return 0;
 892         if (!kref_get_unless_zero(&gss_pipe->kref))
 893                 return 0;
 894         return 1;
 895 }
 896
 897 static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
 898 {
 899         struct gss_pipe *gss_pipe;
 900         struct gss_alloc_pdo *args = data;
 901
 902         gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
 903         if (!IS_ERR(gss_pipe))
 904                 return &gss_pipe->pdo;
 905         return NULL;
 906 }
 907
 908 static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
 909                 const char *name,
 910                 const struct rpc_pipe_ops *upcall_ops)
 911 {
 912         struct net *net = rpc_net_ns(clnt);
 913         struct rpc_pipe_dir_object *pdo;
 914         struct gss_alloc_pdo args = {
 915                 .clnt = clnt,
 916                 .name = name,
 917                 .upcall_ops = upcall_ops,
 918         };
 919
 920         pdo = rpc_find_or_alloc_pipe_dir_object(net,
 921                         &clnt->cl_pipedir_objects,
 922                         gss_pipe_match_pdo,
 923                         gss_pipe_alloc_pdo,
 924                         &args);
 925         if (pdo != NULL)
 926                 return container_of(pdo, struct gss_pipe, pdo);
 927         return ERR_PTR(-ENOMEM);
 928 }
 929
 930 static void __gss_pipe_free(struct gss_pipe *p)
 931 {
 932         struct rpc_clnt *clnt = p->clnt;
 933         struct net *net = rpc_net_ns(clnt);
 934
 935         rpc_remove_pipe_dir_object(net,
 936                         &clnt->cl_pipedir_objects,
 937                         &p->pdo);
 938         rpc_destroy_pipe_data(p->pipe);
 939         kfree(p);
 940 }
 941
 942 static void __gss_pipe_release(struct kref *kref)
 943 {
 944         struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
 945
 946         __gss_pipe_free(p);
 947 }
 948
 949 static void gss_pipe_free(struct gss_pipe *p)
 950 {
 951         if (p != NULL)
 952                 kref_put(&p->kref, __gss_pipe_release);
 953 }
 954
 955 /*
 956  * NOTE: we have the opportunity to use different
 957  * parameters based on the input flavor (which must be a pseudoflavor)
 958  */
 959 static struct gss_auth *
 960 gss_create_new(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
 961 {
 962         rpc_authflavor_t flavor = args->pseudoflavor;
 963         struct gss_auth *gss_auth;
 964         struct gss_pipe *gss_pipe;
 965         struct rpc_auth * auth;
 966         int err = -ENOMEM; /* XXX? */
 967
 968         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 969
 970         if (!try_module_get(THIS_MODULE))
 971                 return ERR_PTR(err);
 972         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 973                 goto out_dec;
 974         INIT_HLIST_NODE(&gss_auth->hash);
 975         gss_auth->target_name = NULL;
 976         if (args->target_name) {
 977                 gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
 978                 if (gss_auth->target_name == NULL)
 979                         goto err_free;
 980         }
 981         gss_auth->client = clnt;
 982         gss_auth->net = get_net(rpc_net_ns(clnt));
 983         err = -EINVAL;
 984         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 985         if (!gss_auth->mech) {
 986                 dprintk("RPC:       Pseudoflavor %d not found!\n", flavor);
 987                 goto err_put_net;
 988         }
 989         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 990         if (gss_auth->service == 0)
 991                 goto err_put_mech;
 992         if (!gssd_running(gss_auth->net))
 993                 goto err_put_mech;
 994         auth = &gss_auth->rpc_auth;
 995         auth->au_cslack = GSS_CRED_SLACK >> 2;
 996         auth->au_rslack = GSS_VERF_SLACK >> 2;
 997         auth->au_ops = &authgss_ops;
 998         auth->au_flavor = flavor;
 999         atomic_set(&auth->au_count, 1);
1000         kref_init(&gss_auth->kref);
1001
1002         err = rpcauth_init_credcache(auth);
1003         if (err)
1004                 goto err_put_mech;
1005         /*
1006          * Note: if we created the old pipe first, then someone who
1007          * examined the directory at the right moment might conclude
1008          * that we supported only the old pipe.  So we instead create
1009          * the new pipe first.
1010          */
1011         gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
1012         if (IS_ERR(gss_pipe)) {
1013                 err = PTR_ERR(gss_pipe);
1014                 goto err_destroy_credcache;
1015         }
1016         gss_auth->gss_pipe[1] = gss_pipe;
1017
1018         gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
1019                         &gss_upcall_ops_v0);
1020         if (IS_ERR(gss_pipe)) {
1021                 err = PTR_ERR(gss_pipe);
1022                 goto err_destroy_pipe_1;
1023         }
1024         gss_auth->gss_pipe[0] = gss_pipe;
1025
1026         return gss_auth;
1027 err_destroy_pipe_1:
1028         gss_pipe_free(gss_auth->gss_pipe[1]);
1029 err_destroy_credcache:
1030         rpcauth_destroy_credcache(auth);
1031 err_put_mech:
1032         gss_mech_put(gss_auth->mech);
1033 err_put_net:
1034         put_net(gss_auth->net);
1035 err_free:
1036         kfree(gss_auth->target_name);
1037         kfree(gss_auth);
1038 out_dec:
1039         module_put(THIS_MODULE);
1040         return ERR_PTR(err);
1041 }
1042
1043 static void
1044 gss_free(struct gss_auth *gss_auth)
1045 {
1046         gss_pipe_free(gss_auth->gss_pipe[0]);
1047         gss_pipe_free(gss_auth->gss_pipe[1]);
1048         gss_mech_put(gss_auth->mech);
1049         put_net(gss_auth->net);
1050         kfree(gss_auth->target_name);
1051
1052         kfree(gss_auth);
1053         module_put(THIS_MODULE);
1054 }
1055
1056 static void
1057 gss_free_callback(struct kref *kref)
1058 {
1059         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1060
1061         gss_free(gss_auth);
1062 }
1063
1064 static void
1065 gss_put_auth(struct gss_auth *gss_auth)
1066 {
1067         kref_put(&gss_auth->kref, gss_free_callback);
1068 }
1069
1070 static void
1071 gss_destroy(struct rpc_auth *auth)
1072 {
1073         struct gss_auth *gss_auth = container_of(auth,
1074                         struct gss_auth, rpc_auth);
1075
1076         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
1077                         auth, auth->au_flavor);
1078
1079         if (hash_hashed(&gss_auth->hash)) {
1080                 spin_lock(&gss_auth_hash_lock);
1081                 hash_del(&gss_auth->hash);
1082                 spin_unlock(&gss_auth_hash_lock);
1083         }
1084
1085         gss_pipe_free(gss_auth->gss_pipe[0]);
1086         gss_auth->gss_pipe[0] = NULL;
1087         gss_pipe_free(gss_auth->gss_pipe[1]);
1088         gss_auth->gss_pipe[1] = NULL;
1089         rpcauth_destroy_credcache(auth);
1090
1091         gss_put_auth(gss_auth);
1092 }
1093
1094 /*
1095  * Auths may be shared between rpc clients that were cloned from a
1096  * common client with the same xprt, if they also share the flavor and
1097  * target_name.
1098  *
1099  * The auth is looked up from the oldest parent sharing the same
1100  * cl_xprt, and the auth itself references only that common parent
1101  * (which is guaranteed to last as long as any of its descendants).
1102  */
1103 static struct gss_auth *
1104 gss_auth_find_or_add_hashed(struct rpc_auth_create_args *args,
1105                 struct rpc_clnt *clnt,
1106                 struct gss_auth *new)
1107 {
1108         struct gss_auth *gss_auth;
1109         unsigned long hashval = (unsigned long)clnt;
1110
1111         spin_lock(&gss_auth_hash_lock);
1112         hash_for_each_possible(gss_auth_hash_table,
1113                         gss_auth,
1114                         hash,
1115                         hashval) {
1116                 if (gss_auth->client != clnt)
1117                         continue;
1118                 if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1119                         continue;
1120                 if (gss_auth->target_name != args->target_name) {
1121                         if (gss_auth->target_name == NULL)
1122                                 continue;
1123                         if (args->target_name == NULL)
1124                                 continue;
1125                         if (strcmp(gss_auth->target_name, args->target_name))
1126                                 continue;
1127                 }
1128                 if (!atomic_inc_not_zero(&gss_auth->rpc_auth.au_count))
1129                         continue;
1130                 goto out;
1131         }
1132         if (new)
1133                 hash_add(gss_auth_hash_table, &new->hash, hashval);
1134         gss_auth = new;
1135 out:
1136         spin_unlock(&gss_auth_hash_lock);
1137         return gss_auth;
1138 }
1139
1140 static struct gss_auth *
1141 gss_create_hashed(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1142 {
1143         struct gss_auth *gss_auth;
1144         struct gss_auth *new;
1145
1146         gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1147         if (gss_auth != NULL)
1148                 goto out;
1149         new = gss_create_new(args, clnt);
1150         if (IS_ERR(new))
1151                 return new;
1152         gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1153         if (gss_auth != new)
1154                 gss_destroy(&new->rpc_auth);
1155 out:
1156         return gss_auth;
1157 }
1158
1159 static struct rpc_auth *
1160 gss_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1161 {
1162         struct gss_auth *gss_auth;
1163         struct rpc_xprt *xprt = rcu_access_pointer(clnt->cl_xprt);
1164
1165         while (clnt != clnt->cl_parent) {
1166                 struct rpc_clnt *parent = clnt->cl_parent;
1167                 /* Find the original parent for this transport */
1168                 if (rcu_access_pointer(parent->cl_xprt) != xprt)
1169                         break;
1170                 clnt = parent;
1171         }
1172
1173         gss_auth = gss_create_hashed(args, clnt);
1174         if (IS_ERR(gss_auth))
1175                 return ERR_CAST(gss_auth);
1176         return &gss_auth->rpc_auth;
1177 }
1178
1179 /*
1180  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
1181  * to the server with the GSS control procedure field set to
1182  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1183  * all RPCSEC_GSS state associated with that context.
1184  */
1185 static int
1186 gss_destroying_context(struct rpc_cred *cred)
1187 {
1188         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1189         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1190         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1191         struct rpc_task *task;
1192
1193         if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
1194                 return 0;
1195
1196         ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1197         cred->cr_ops = &gss_nullops;
1198
1199         /* Take a reference to ensure the cred will be destroyed either
1200          * by the RPC call or by the put_rpccred() below */
1201         get_rpccred(cred);
1202
1203         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
1204         if (!IS_ERR(task))
1205                 rpc_put_task(task);
1206
1207         put_rpccred(cred);
1208         return 1;
1209 }
1210
1211 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1212  * to create a new cred or context, so they check that things have been
1213  * allocated before freeing them. */
1214 static void
1215 gss_do_free_ctx(struct gss_cl_ctx *ctx)
1216 {
1217         dprintk("RPC:       %s\n", __func__);
1218
1219         gss_delete_sec_context(&ctx->gc_gss_ctx);
1220         kfree(ctx->gc_wire_ctx.data);
1221         kfree(ctx->gc_acceptor.data);
1222         kfree(ctx);
1223 }
1224
1225 static void
1226 gss_free_ctx_callback(struct rcu_head *head)
1227 {
1228         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1229         gss_do_free_ctx(ctx);
1230 }
1231
1232 static void
1233 gss_free_ctx(struct gss_cl_ctx *ctx)
1234 {
1235         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1236 }
1237
1238 static void
1239 gss_free_cred(struct gss_cred *gss_cred)
1240 {
1241         dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1242         kfree(gss_cred);
1243 }
1244
1245 static void
1246 gss_free_cred_callback(struct rcu_head *head)
1247 {
1248         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1249         gss_free_cred(gss_cred);
1250 }
1251
1252 static void
1253 gss_destroy_nullcred(struct rpc_cred *cred)
1254 {
1255         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1256         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1257         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1258
1259         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1260         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1261         if (ctx)
1262                 gss_put_ctx(ctx);
1263         gss_put_auth(gss_auth);
1264 }
1265
1266 static void
1267 gss_destroy_cred(struct rpc_cred *cred)
1268 {
1269
1270         if (gss_destroying_context(cred))
1271                 return;
1272         gss_destroy_nullcred(cred);
1273 }
1274
1275 /*
1276  * Lookup RPCSEC_GSS cred for the current process
1277  */
1278 static struct rpc_cred *
1279 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1280 {
1281         return rpcauth_lookup_credcache(auth, acred, flags);
1282 }
1283
1284 static struct rpc_cred *
1285 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1286 {
1287         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1288         struct gss_cred *cred = NULL;
1289         int err = -ENOMEM;
1290
1291         dprintk("RPC:       %s for uid %d, flavor %d\n",
1292                 __func__, from_kuid(&init_user_ns, acred->uid),
1293                 auth->au_flavor);
1294
1295         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
1296                 goto out_err;
1297
1298         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1299         /*
1300          * Note: in order to force a call to call_refresh(), we deliberately
1301          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1302          */
1303         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1304         cred->gc_service = gss_auth->service;
1305         cred->gc_principal = NULL;
1306         if (acred->machine_cred)
1307                 cred->gc_principal = acred->principal;
1308         kref_get(&gss_auth->kref);
1309         return &cred->gc_base;
1310
1311 out_err:
1312         dprintk("RPC:       %s failed with error %d\n", __func__, err);
1313         return ERR_PTR(err);
1314 }
1315
1316 static int
1317 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1318 {
1319         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1320         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1321         int err;
1322
1323         do {
1324                 err = gss_create_upcall(gss_auth, gss_cred);
1325         } while (err == -EAGAIN);
1326         return err;
1327 }
1328
1329 static char *
1330 gss_stringify_acceptor(struct rpc_cred *cred)
1331 {
1332         char *string = NULL;
1333         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1334         struct gss_cl_ctx *ctx;
1335         unsigned int len;
1336         struct xdr_netobj *acceptor;
1337
1338         rcu_read_lock();
1339         ctx = rcu_dereference(gss_cred->gc_ctx);
1340         if (!ctx)
1341                 goto out;
1342
1343         len = ctx->gc_acceptor.len;
1344         rcu_read_unlock();
1345
1346         /* no point if there's no string */
1347         if (!len)
1348                 return NULL;
1349 realloc:
1350         string = kmalloc(len + 1, GFP_KERNEL);
1351         if (!string)
1352                 return NULL;
1353
1354         rcu_read_lock();
1355         ctx = rcu_dereference(gss_cred->gc_ctx);
1356
1357         /* did the ctx disappear or was it replaced by one with no acceptor? */
1358         if (!ctx || !ctx->gc_acceptor.len) {
1359                 kfree(string);
1360                 string = NULL;
1361                 goto out;
1362         }
1363
1364         acceptor = &ctx->gc_acceptor;
1365
1366         /*
1367          * Did we find a new acceptor that's longer than the original? Allocate
1368          * a longer buffer and try again.
1369          */
1370         if (len < acceptor->len) {
1371                 len = acceptor->len;
1372                 rcu_read_unlock();
1373                 kfree(string);
1374                 goto realloc;
1375         }
1376
1377         memcpy(string, acceptor->data, acceptor->len);
1378         string[acceptor->len] = '\0';
1379 out:
1380         rcu_read_unlock();
1381         return string;
1382 }
1383
1384 /*
1385  * Returns -EACCES if GSS context is NULL or will expire within the
1386  * timeout (miliseconds)
1387  */
1388 static int
1389 gss_key_timeout(struct rpc_cred *rc)
1390 {
1391         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1392         struct gss_cl_ctx *ctx;
1393         unsigned long timeout = jiffies + (gss_key_expire_timeo * HZ);
1394         int ret = 0;
1395
1396         rcu_read_lock();
1397         ctx = rcu_dereference(gss_cred->gc_ctx);
1398         if (!ctx || time_after(timeout, ctx->gc_expiry))
1399                 ret = -EACCES;
1400         rcu_read_unlock();
1401
1402         return ret;
1403 }
1404
1405 static int
1406 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1407 {
1408         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1409         struct gss_cl_ctx *ctx;
1410         int ret;
1411
1412         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1413                 goto out;
1414         /* Don't match with creds that have expired. */
1415         rcu_read_lock();
1416         ctx = rcu_dereference(gss_cred->gc_ctx);
1417         if (!ctx || time_after(jiffies, ctx->gc_expiry)) {
1418                 rcu_read_unlock();
1419                 return 0;
1420         }
1421         rcu_read_unlock();
1422         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1423                 return 0;
1424 out:
1425         if (acred->principal != NULL) {
1426                 if (gss_cred->gc_principal == NULL)
1427                         return 0;
1428                 ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1429                 goto check_expire;
1430         }
1431         if (gss_cred->gc_principal != NULL)
1432                 return 0;
1433         ret = uid_eq(rc->cr_uid, acred->uid);
1434
1435 check_expire:
1436         if (ret == 0)
1437                 return ret;
1438
1439         /* Notify acred users of GSS context expiration timeout */
1440         if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags) &&
1441             (gss_key_timeout(rc) != 0)) {
1442                 /* test will now be done from generic cred */
1443                 test_and_clear_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
1444                 /* tell NFS layer that key will expire soon */
1445                 set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
1446         }
1447         return ret;
1448 }
1449
1450 /*
1451 * Marshal credentials.
1452 * Maybe we should keep a cached credential for performance reasons.
1453 */
1454 static __be32 *
1455 gss_marshal(struct rpc_task *task, __be32 *p)
1456 {
1457         struct rpc_rqst *req = task->tk_rqstp;
1458         struct rpc_cred *cred = req->rq_cred;
1459         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1460                                                  gc_base);
1461         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1462         __be32          *cred_len;
1463         u32             maj_stat = 0;
1464         struct xdr_netobj mic;
1465         struct kvec     iov;
1466         struct xdr_buf  verf_buf;
1467
1468         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1469
1470         *p++ = htonl(RPC_AUTH_GSS);
1471         cred_len = p++;
1472
1473         spin_lock(&ctx->gc_seq_lock);
1474         req->rq_seqno = ctx->gc_seq++;
1475         spin_unlock(&ctx->gc_seq_lock);
1476
1477         *p++ = htonl((u32) RPC_GSS_VERSION);
1478         *p++ = htonl((u32) ctx->gc_proc);
1479         *p++ = htonl((u32) req->rq_seqno);
1480         *p++ = htonl((u32) gss_cred->gc_service);
1481         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1482         *cred_len = htonl((p - (cred_len + 1)) << 2);
1483
1484         /* We compute the checksum for the verifier over the xdr-encoded bytes
1485          * starting with the xid and ending at the end of the credential: */
1486         iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
1487                                         req->rq_snd_buf.head[0].iov_base);
1488         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1489         xdr_buf_from_iov(&iov, &verf_buf);
1490
1491         /* set verifier flavor*/
1492         *p++ = htonl(RPC_AUTH_GSS);
1493
1494         mic.data = (u8 *)(p + 1);
1495         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1496         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1497                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1498         } else if (maj_stat != 0) {
1499                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1500                 goto out_put_ctx;
1501         }
1502         p = xdr_encode_opaque(p, NULL, mic.len);
1503         gss_put_ctx(ctx);
1504         return p;
1505 out_put_ctx:
1506         gss_put_ctx(ctx);
1507         return NULL;
1508 }
1509
1510 static int gss_renew_cred(struct rpc_task *task)
1511 {
1512         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1513         struct gss_cred *gss_cred = container_of(oldcred,
1514                                                  struct gss_cred,
1515                                                  gc_base);
1516         struct rpc_auth *auth = oldcred->cr_auth;
1517         struct auth_cred acred = {
1518                 .uid = oldcred->cr_uid,
1519                 .principal = gss_cred->gc_principal,
1520                 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
1521         };
1522         struct rpc_cred *new;
1523
1524         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1525         if (IS_ERR(new))
1526                 return PTR_ERR(new);
1527         task->tk_rqstp->rq_cred = new;
1528         put_rpccred(oldcred);
1529         return 0;
1530 }
1531
1532 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1533 {
1534         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1535                 unsigned long now = jiffies;
1536                 unsigned long begin, expire;
1537                 struct gss_cred *gss_cred;
1538
1539                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1540                 begin = gss_cred->gc_upcall_timestamp;
1541                 expire = begin + gss_expired_cred_retry_delay * HZ;
1542
1543                 if (time_in_range_open(now, begin, expire))
1544                         return 1;
1545         }
1546         return 0;
1547 }
1548
1549 /*
1550 * Refresh credentials. XXX - finish
1551 */
1552 static int
1553 gss_refresh(struct rpc_task *task)
1554 {
1555         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1556         int ret = 0;
1557
1558         if (gss_cred_is_negative_entry(cred))
1559                 return -EKEYEXPIRED;
1560
1561         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1562                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1563                 ret = gss_renew_cred(task);
1564                 if (ret < 0)
1565                         goto out;
1566                 cred = task->tk_rqstp->rq_cred;
1567         }
1568
1569         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1570                 ret = gss_refresh_upcall(task);
1571 out:
1572         return ret;
1573 }
1574
1575 /* Dummy refresh routine: used only when destroying the context */
1576 static int
1577 gss_refresh_null(struct rpc_task *task)
1578 {
1579         return 0;
1580 }
1581
1582 static __be32 *
1583 gss_validate(struct rpc_task *task, __be32 *p)
1584 {
1585         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1586         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1587         __be32          seq;
1588         struct kvec     iov;
1589         struct xdr_buf  verf_buf;
1590         struct xdr_netobj mic;
1591         u32             flav,len;
1592         u32             maj_stat;
1593         __be32          *ret = ERR_PTR(-EIO);
1594
1595         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1596
1597         flav = ntohl(*p++);
1598         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1599                 goto out_bad;
1600         if (flav != RPC_AUTH_GSS)
1601                 goto out_bad;
1602         seq = htonl(task->tk_rqstp->rq_seqno);
1603         iov.iov_base = &seq;
1604         iov.iov_len = sizeof(seq);
1605         xdr_buf_from_iov(&iov, &verf_buf);
1606         mic.data = (u8 *)p;
1607         mic.len = len;
1608
1609         ret = ERR_PTR(-EACCES);
1610         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1611         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1612                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1613         if (maj_stat) {
1614                 dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1615                         task->tk_pid, __func__, maj_stat);
1616                 goto out_bad;
1617         }
1618         /* We leave it to unwrap to calculate au_rslack. For now we just
1619          * calculate the length of the verifier: */
1620         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1621         gss_put_ctx(ctx);
1622         dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1623                         task->tk_pid, __func__);
1624         return p + XDR_QUADLEN(len);
1625 out_bad:
1626         gss_put_ctx(ctx);
1627         dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
1628                 PTR_ERR(ret));
1629         return ret;
1630 }
1631
1632 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1633                                 __be32 *p, void *obj)
1634 {
1635         struct xdr_stream xdr;
1636
1637         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1638         encode(rqstp, &xdr, obj);
1639 }
1640
1641 static inline int
1642 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1643                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1644                    __be32 *p, void *obj)
1645 {
1646         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1647         struct xdr_buf  integ_buf;
1648         __be32          *integ_len = NULL;
1649         struct xdr_netobj mic;
1650         u32             offset;
1651         __be32          *q;
1652         struct kvec     *iov;
1653         u32             maj_stat = 0;
1654         int             status = -EIO;
1655
1656         integ_len = p++;
1657         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1658         *p++ = htonl(rqstp->rq_seqno);
1659
1660         gss_wrap_req_encode(encode, rqstp, p, obj);
1661
1662         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1663                                 offset, snd_buf->len - offset))
1664                 return status;
1665         *integ_len = htonl(integ_buf.len);
1666
1667         /* guess whether we're in the head or the tail: */
1668         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1669                 iov = snd_buf->tail;
1670         else
1671                 iov = snd_buf->head;
1672         p = iov->iov_base + iov->iov_len;
1673         mic.data = (u8 *)(p + 1);
1674
1675         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1676         status = -EIO; /* XXX? */
1677         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1678                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1679         else if (maj_stat)
1680                 return status;
1681         q = xdr_encode_opaque(p, NULL, mic.len);
1682
1683         offset = (u8 *)q - (u8 *)p;
1684         iov->iov_len += offset;
1685         snd_buf->len += offset;
1686         return 0;
1687 }
1688
1689 static void
1690 priv_release_snd_buf(struct rpc_rqst *rqstp)
1691 {
1692         int i;
1693
1694         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1695                 __free_page(rqstp->rq_enc_pages[i]);
1696         kfree(rqstp->rq_enc_pages);
1697         rqstp->rq_release_snd_buf = NULL;
1698 }
1699
1700 static int
1701 alloc_enc_pages(struct rpc_rqst *rqstp)
1702 {
1703         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1704         int first, last, i;
1705
1706         if (rqstp->rq_release_snd_buf)
1707                 rqstp->rq_release_snd_buf(rqstp);
1708
1709         if (snd_buf->page_len == 0) {
1710                 rqstp->rq_enc_pages_num = 0;
1711                 return 0;
1712         }
1713
1714         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1715         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1716         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1717         rqstp->rq_enc_pages
1718                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1719                                 GFP_NOFS);
1720         if (!rqstp->rq_enc_pages)
1721                 goto out;
1722         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1723                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1724                 if (rqstp->rq_enc_pages[i] == NULL)
1725                         goto out_free;
1726         }
1727         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1728         return 0;
1729 out_free:
1730         rqstp->rq_enc_pages_num = i;
1731         priv_release_snd_buf(rqstp);
1732 out:
1733         return -EAGAIN;
1734 }
1735
1736 static inline int
1737 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1738                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1739                   __be32 *p, void *obj)
1740 {
1741         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1742         u32             offset;
1743         u32             maj_stat;
1744         int             status;
1745         __be32          *opaque_len;
1746         struct page     **inpages;
1747         int             first;
1748         int             pad;
1749         struct kvec     *iov;
1750         char            *tmp;
1751
1752         opaque_len = p++;
1753         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1754         *p++ = htonl(rqstp->rq_seqno);
1755
1756         gss_wrap_req_encode(encode, rqstp, p, obj);
1757
1758         status = alloc_enc_pages(rqstp);
1759         if (status)
1760                 return status;
1761         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1762         inpages = snd_buf->pages + first;
1763         snd_buf->pages = rqstp->rq_enc_pages;
1764         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1765         /*
1766          * Give the tail its own page, in case we need extra space in the
1767          * head when wrapping:
1768          *
1769          * call_allocate() allocates twice the slack space required
1770          * by the authentication flavor to rq_callsize.
1771          * For GSS, slack is GSS_CRED_SLACK.
1772          */
1773         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1774                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1775                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1776                 snd_buf->tail[0].iov_base = tmp;
1777         }
1778         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1779         /* slack space should prevent this ever happening: */
1780         BUG_ON(snd_buf->len > snd_buf->buflen);
1781         status = -EIO;
1782         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1783          * done anyway, so it's safe to put the request on the wire: */
1784         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1785                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1786         else if (maj_stat)
1787                 return status;
1788
1789         *opaque_len = htonl(snd_buf->len - offset);
1790         /* guess whether we're in the head or the tail: */
1791         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1792                 iov = snd_buf->tail;
1793         else
1794                 iov = snd_buf->head;
1795         p = iov->iov_base + iov->iov_len;
1796         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1797         memset(p, 0, pad);
1798         iov->iov_len += pad;
1799         snd_buf->len += pad;
1800
1801         return 0;
1802 }
1803
1804 static int
1805 gss_wrap_req(struct rpc_task *task,
1806              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1807 {
1808         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1809         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1810                         gc_base);
1811         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1812         int             status = -EIO;
1813
1814         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1815         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1816                 /* The spec seems a little ambiguous here, but I think that not
1817                  * wrapping context destruction requests makes the most sense.
1818                  */
1819                 gss_wrap_req_encode(encode, rqstp, p, obj);
1820                 status = 0;
1821                 goto out;
1822         }
1823         switch (gss_cred->gc_service) {
1824         case RPC_GSS_SVC_NONE:
1825                 gss_wrap_req_encode(encode, rqstp, p, obj);
1826                 status = 0;
1827                 break;
1828         case RPC_GSS_SVC_INTEGRITY:
1829                 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1830                 break;
1831         case RPC_GSS_SVC_PRIVACY:
1832                 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1833                 break;
1834         }
1835 out:
1836         gss_put_ctx(ctx);
1837         dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1838         return status;
1839 }
1840
1841 static inline int
1842 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1843                 struct rpc_rqst *rqstp, __be32 **p)
1844 {
1845         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1846         struct xdr_buf integ_buf;
1847         struct xdr_netobj mic;
1848         u32 data_offset, mic_offset;
1849         u32 integ_len;
1850         u32 maj_stat;
1851         int status = -EIO;
1852
1853         integ_len = ntohl(*(*p)++);
1854         if (integ_len & 3)
1855                 return status;
1856         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1857         mic_offset = integ_len + data_offset;
1858         if (mic_offset > rcv_buf->len)
1859                 return status;
1860         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1861                 return status;
1862
1863         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1864                                 mic_offset - data_offset))
1865                 return status;
1866
1867         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1868                 return status;
1869
1870         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1871         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1872                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1873         if (maj_stat != GSS_S_COMPLETE)
1874                 return status;
1875         return 0;
1876 }
1877
1878 static inline int
1879 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1880                 struct rpc_rqst *rqstp, __be32 **p)
1881 {
1882         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1883         u32 offset;
1884         u32 opaque_len;
1885         u32 maj_stat;
1886         int status = -EIO;
1887
1888         opaque_len = ntohl(*(*p)++);
1889         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1890         if (offset + opaque_len > rcv_buf->len)
1891                 return status;
1892         /* remove padding: */
1893         rcv_buf->len = offset + opaque_len;
1894
1895         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1896         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1897                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1898         if (maj_stat != GSS_S_COMPLETE)
1899                 return status;
1900         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1901                 return status;
1902
1903         return 0;
1904 }
1905
1906 static int
1907 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1908                       __be32 *p, void *obj)
1909 {
1910         struct xdr_stream xdr;
1911
1912         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1913         return decode(rqstp, &xdr, obj);
1914 }
1915
1916 static int
1917 gss_unwrap_resp(struct rpc_task *task,
1918                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1919 {
1920         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1921         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1922                         gc_base);
1923         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1924         __be32          *savedp = p;
1925         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1926         int             savedlen = head->iov_len;
1927         int             status = -EIO;
1928
1929         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1930                 goto out_decode;
1931         switch (gss_cred->gc_service) {
1932         case RPC_GSS_SVC_NONE:
1933                 break;
1934         case RPC_GSS_SVC_INTEGRITY:
1935                 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1936                 if (status)
1937                         goto out;
1938                 break;
1939         case RPC_GSS_SVC_PRIVACY:
1940                 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1941                 if (status)
1942                         goto out;
1943                 break;
1944         }
1945         /* take into account extra slack for integrity and privacy cases: */
1946         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1947                                                 + (savedlen - head->iov_len);
1948 out_decode:
1949         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
1950 out:
1951         gss_put_ctx(ctx);
1952         dprintk("RPC: %5u %s returning %d\n",
1953                 task->tk_pid, __func__, status);
1954         return status;
1955 }
1956
1957 static const struct rpc_authops authgss_ops = {
1958         .owner          = THIS_MODULE,
1959         .au_flavor      = RPC_AUTH_GSS,
1960         .au_name        = "RPCSEC_GSS",
1961         .create         = gss_create,
1962         .destroy        = gss_destroy,
1963         .lookup_cred    = gss_lookup_cred,
1964         .crcreate       = gss_create_cred,
1965         .list_pseudoflavors = gss_mech_list_pseudoflavors,
1966         .info2flavor    = gss_mech_info2flavor,
1967         .flavor2info    = gss_mech_flavor2info,
1968 };
1969
1970 static const struct rpc_credops gss_credops = {
1971         .cr_name                = "AUTH_GSS",
1972         .crdestroy              = gss_destroy_cred,
1973         .cr_init                = gss_cred_init,
1974         .crbind                 = rpcauth_generic_bind_cred,
1975         .crmatch                = gss_match,
1976         .crmarshal              = gss_marshal,
1977         .crrefresh              = gss_refresh,
1978         .crvalidate             = gss_validate,
1979         .crwrap_req             = gss_wrap_req,
1980         .crunwrap_resp          = gss_unwrap_resp,
1981         .crkey_timeout          = gss_key_timeout,
1982         .crstringify_acceptor   = gss_stringify_acceptor,
1983 };
1984
1985 static const struct rpc_credops gss_nullops = {
1986         .cr_name                = "AUTH_GSS",
1987         .crdestroy              = gss_destroy_nullcred,
1988         .crbind                 = rpcauth_generic_bind_cred,
1989         .crmatch                = gss_match,
1990         .crmarshal              = gss_marshal,
1991         .crrefresh              = gss_refresh_null,
1992         .crvalidate             = gss_validate,
1993         .crwrap_req             = gss_wrap_req,
1994         .crunwrap_resp          = gss_unwrap_resp,
1995         .crstringify_acceptor   = gss_stringify_acceptor,
1996 };
1997
1998 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
1999         .upcall         = rpc_pipe_generic_upcall,
2000         .downcall       = gss_pipe_downcall,
2001         .destroy_msg    = gss_pipe_destroy_msg,
2002         .open_pipe      = gss_pipe_open_v0,
2003         .release_pipe   = gss_pipe_release,
2004 };
2005
2006 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
2007         .upcall         = rpc_pipe_generic_upcall,
2008         .downcall       = gss_pipe_downcall,
2009         .destroy_msg    = gss_pipe_destroy_msg,
2010         .open_pipe      = gss_pipe_open_v1,
2011         .release_pipe   = gss_pipe_release,
2012 };
2013
2014 static __net_init int rpcsec_gss_init_net(struct net *net)
2015 {
2016         return gss_svc_init_net(net);
2017 }
2018
2019 static __net_exit void rpcsec_gss_exit_net(struct net *net)
2020 {
2021         gss_svc_shutdown_net(net);
2022 }
2023
2024 static struct pernet_operations rpcsec_gss_net_ops = {
2025         .init = rpcsec_gss_init_net,
2026         .exit = rpcsec_gss_exit_net,
2027 };
2028
2029 /*
2030  * Initialize RPCSEC_GSS module
2031  */
2032 static int __init init_rpcsec_gss(void)
2033 {
2034         int err = 0;
2035
2036         err = rpcauth_register(&authgss_ops);
2037         if (err)
2038                 goto out;
2039         err = gss_svc_init();
2040         if (err)
2041                 goto out_unregister;
2042         err = register_pernet_subsys(&rpcsec_gss_net_ops);
2043         if (err)
2044                 goto out_svc_exit;
2045         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
2046         return 0;
2047 out_svc_exit:
2048         gss_svc_shutdown();
2049 out_unregister:
2050         rpcauth_unregister(&authgss_ops);
2051 out:
2052         return err;
2053 }
2054
2055 static void __exit exit_rpcsec_gss(void)
2056 {
2057         unregister_pernet_subsys(&rpcsec_gss_net_ops);
2058         gss_svc_shutdown();
2059         rpcauth_unregister(&authgss_ops);
2060         rcu_barrier(); /* Wait for completion of call_rcu()'s */
2061 }
2062
2063 MODULE_ALIAS("rpc-auth-6");
2064 MODULE_LICENSE("GPL");
2065 module_param_named(expired_cred_retry_delay,
2066                    gss_expired_cred_retry_delay,
2067                    uint, 0644);
2068 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
2069                 "the RPC engine retries an expired credential");
2070
2071 module_param_named(key_expire_timeo,
2072                    gss_key_expire_timeo,
2073                    uint, 0644);
2074 MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
2075                 "credential keys lifetime where the NFS layer cleans up "
2076                 "prior to key expiration");
2077
2078 module_init(init_rpcsec_gss)
2079 module_exit(exit_rpcsec_gss)