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 #define UPCALL_BUF_LEN 128
 260
 261 struct gss_upcall_msg {
 262         refcount_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 (!refcount_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 (pos->auth->service != auth->service)
 322                         continue;
 323                 refcount_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                 refcount_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         refcount_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         refcount_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                 refcount_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                         refcount_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                 refcount_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 static struct gss_upcall_msg *
 650 gss_find_downcall(struct rpc_pipe *pipe, kuid_t uid)
 651 {
 652         struct gss_upcall_msg *pos;
 653         list_for_each_entry(pos, &pipe->in_downcall, list) {
 654                 if (!uid_eq(pos->uid, uid))
 655                         continue;
 656                 if (!rpc_msg_is_inflight(&pos->msg))
 657                         continue;
 658                 refcount_inc(&pos->count);
 659                 return pos;
 660         }
 661         return NULL;
 662 }
 663
 664 #define MSG_BUF_MAXSIZE 1024
 665
 666 static ssize_t
 667 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 668 {
 669         const void *p, *end;
 670         void *buf;
 671         struct gss_upcall_msg *gss_msg;
 672         struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
 673         struct gss_cl_ctx *ctx;
 674         uid_t id;
 675         kuid_t uid;
 676         ssize_t err = -EFBIG;
 677
 678         if (mlen > MSG_BUF_MAXSIZE)
 679                 goto out;
 680         err = -ENOMEM;
 681         buf = kmalloc(mlen, GFP_NOFS);
 682         if (!buf)
 683                 goto out;
 684
 685         err = -EFAULT;
 686         if (copy_from_user(buf, src, mlen))
 687                 goto err;
 688
 689         end = (const void *)((char *)buf + mlen);
 690         p = simple_get_bytes(buf, end, &id, sizeof(id));
 691         if (IS_ERR(p)) {
 692                 err = PTR_ERR(p);
 693                 goto err;
 694         }
 695
 696         uid = make_kuid(&init_user_ns, id);
 697         if (!uid_valid(uid)) {
 698                 err = -EINVAL;
 699                 goto err;
 700         }
 701
 702         err = -ENOMEM;
 703         ctx = gss_alloc_context();
 704         if (ctx == NULL)
 705                 goto err;
 706
 707         err = -ENOENT;
 708         /* Find a matching upcall */
 709         spin_lock(&pipe->lock);
 710         gss_msg = gss_find_downcall(pipe, uid);
 711         if (gss_msg == NULL) {
 712                 spin_unlock(&pipe->lock);
 713                 goto err_put_ctx;
 714         }
 715         list_del_init(&gss_msg->list);
 716         spin_unlock(&pipe->lock);
 717
 718         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 719         if (IS_ERR(p)) {
 720                 err = PTR_ERR(p);
 721                 switch (err) {
 722                 case -EACCES:
 723                 case -EKEYEXPIRED:
 724                         gss_msg->msg.errno = err;
 725                         err = mlen;
 726                         break;
 727                 case -EFAULT:
 728                 case -ENOMEM:
 729                 case -EINVAL:
 730                 case -ENOSYS:
 731                         gss_msg->msg.errno = -EAGAIN;
 732                         break;
 733                 default:
 734                         printk(KERN_CRIT "%s: bad return from "
 735                                 "gss_fill_context: %zd\n", __func__, err);
 736                         gss_msg->msg.errno = -EIO;
 737                 }
 738                 goto err_release_msg;
 739         }
 740         gss_msg->ctx = gss_get_ctx(ctx);
 741         err = mlen;
 742
 743 err_release_msg:
 744         spin_lock(&pipe->lock);
 745         __gss_unhash_msg(gss_msg);
 746         spin_unlock(&pipe->lock);
 747         gss_release_msg(gss_msg);
 748 err_put_ctx:
 749         gss_put_ctx(ctx);
 750 err:
 751         kfree(buf);
 752 out:
 753         dprintk("RPC:       %s returning %zd\n", __func__, err);
 754         return err;
 755 }
 756
 757 static int gss_pipe_open(struct inode *inode, int new_version)
 758 {
 759         struct net *net = inode->i_sb->s_fs_info;
 760         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 761         int ret = 0;
 762
 763         spin_lock(&pipe_version_lock);
 764         if (sn->pipe_version < 0) {
 765                 /* First open of any gss pipe determines the version: */
 766                 sn->pipe_version = new_version;
 767                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 768                 wake_up(&pipe_version_waitqueue);
 769         } else if (sn->pipe_version != new_version) {
 770                 /* Trying to open a pipe of a different version */
 771                 ret = -EBUSY;
 772                 goto out;
 773         }
 774         atomic_inc(&sn->pipe_users);
 775 out:
 776         spin_unlock(&pipe_version_lock);
 777         return ret;
 778
 779 }
 780
 781 static int gss_pipe_open_v0(struct inode *inode)
 782 {
 783         return gss_pipe_open(inode, 0);
 784 }
 785
 786 static int gss_pipe_open_v1(struct inode *inode)
 787 {
 788         return gss_pipe_open(inode, 1);
 789 }
 790
 791 static void
 792 gss_pipe_release(struct inode *inode)
 793 {
 794         struct net *net = inode->i_sb->s_fs_info;
 795         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 796         struct gss_upcall_msg *gss_msg;
 797
 798 restart:
 799         spin_lock(&pipe->lock);
 800         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
 801
 802                 if (!list_empty(&gss_msg->msg.list))
 803                         continue;
 804                 gss_msg->msg.errno = -EPIPE;
 805                 refcount_inc(&gss_msg->count);
 806                 __gss_unhash_msg(gss_msg);
 807                 spin_unlock(&pipe->lock);
 808                 gss_release_msg(gss_msg);
 809                 goto restart;
 810         }
 811         spin_unlock(&pipe->lock);
 812
 813         put_pipe_version(net);
 814 }
 815
 816 static void
 817 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 818 {
 819         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 820
 821         if (msg->errno < 0) {
 822                 dprintk("RPC:       %s releasing msg %p\n",
 823                         __func__, gss_msg);
 824                 refcount_inc(&gss_msg->count);
 825                 gss_unhash_msg(gss_msg);
 826                 if (msg->errno == -ETIMEDOUT)
 827                         warn_gssd();
 828                 gss_release_msg(gss_msg);
 829         }
 830         gss_release_msg(gss_msg);
 831 }
 832
 833 static void gss_pipe_dentry_destroy(struct dentry *dir,
 834                 struct rpc_pipe_dir_object *pdo)
 835 {
 836         struct gss_pipe *gss_pipe = pdo->pdo_data;
 837         struct rpc_pipe *pipe = gss_pipe->pipe;
 838
 839         if (pipe->dentry != NULL) {
 840                 rpc_unlink(pipe->dentry);
 841                 pipe->dentry = NULL;
 842         }
 843 }
 844
 845 static int gss_pipe_dentry_create(struct dentry *dir,
 846                 struct rpc_pipe_dir_object *pdo)
 847 {
 848         struct gss_pipe *p = pdo->pdo_data;
 849         struct dentry *dentry;
 850
 851         dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
 852         if (IS_ERR(dentry))
 853                 return PTR_ERR(dentry);
 854         p->pipe->dentry = dentry;
 855         return 0;
 856 }
 857
 858 static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
 859         .create = gss_pipe_dentry_create,
 860         .destroy = gss_pipe_dentry_destroy,
 861 };
 862
 863 static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
 864                 const char *name,
 865                 const struct rpc_pipe_ops *upcall_ops)
 866 {
 867         struct gss_pipe *p;
 868         int err = -ENOMEM;
 869
 870         p = kmalloc(sizeof(*p), GFP_KERNEL);
 871         if (p == NULL)
 872                 goto err;
 873         p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 874         if (IS_ERR(p->pipe)) {
 875                 err = PTR_ERR(p->pipe);
 876                 goto err_free_gss_pipe;
 877         }
 878         p->name = name;
 879         p->clnt = clnt;
 880         kref_init(&p->kref);
 881         rpc_init_pipe_dir_object(&p->pdo,
 882                         &gss_pipe_dir_object_ops,
 883                         p);
 884         return p;
 885 err_free_gss_pipe:
 886         kfree(p);
 887 err:
 888         return ERR_PTR(err);
 889 }
 890
 891 struct gss_alloc_pdo {
 892         struct rpc_clnt *clnt;
 893         const char *name;
 894         const struct rpc_pipe_ops *upcall_ops;
 895 };
 896
 897 static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
 898 {
 899         struct gss_pipe *gss_pipe;
 900         struct gss_alloc_pdo *args = data;
 901
 902         if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
 903                 return 0;
 904         gss_pipe = container_of(pdo, struct gss_pipe, pdo);
 905         if (strcmp(gss_pipe->name, args->name) != 0)
 906                 return 0;
 907         if (!kref_get_unless_zero(&gss_pipe->kref))
 908                 return 0;
 909         return 1;
 910 }
 911
 912 static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
 913 {
 914         struct gss_pipe *gss_pipe;
 915         struct gss_alloc_pdo *args = data;
 916
 917         gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
 918         if (!IS_ERR(gss_pipe))
 919                 return &gss_pipe->pdo;
 920         return NULL;
 921 }
 922
 923 static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
 924                 const char *name,
 925                 const struct rpc_pipe_ops *upcall_ops)
 926 {
 927         struct net *net = rpc_net_ns(clnt);
 928         struct rpc_pipe_dir_object *pdo;
 929         struct gss_alloc_pdo args = {
 930                 .clnt = clnt,
 931                 .name = name,
 932                 .upcall_ops = upcall_ops,
 933         };
 934
 935         pdo = rpc_find_or_alloc_pipe_dir_object(net,
 936                         &clnt->cl_pipedir_objects,
 937                         gss_pipe_match_pdo,
 938                         gss_pipe_alloc_pdo,
 939                         &args);
 940         if (pdo != NULL)
 941                 return container_of(pdo, struct gss_pipe, pdo);
 942         return ERR_PTR(-ENOMEM);
 943 }
 944
 945 static void __gss_pipe_free(struct gss_pipe *p)
 946 {
 947         struct rpc_clnt *clnt = p->clnt;
 948         struct net *net = rpc_net_ns(clnt);
 949
 950         rpc_remove_pipe_dir_object(net,
 951                         &clnt->cl_pipedir_objects,
 952                         &p->pdo);
 953         rpc_destroy_pipe_data(p->pipe);
 954         kfree(p);
 955 }
 956
 957 static void __gss_pipe_release(struct kref *kref)
 958 {
 959         struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
 960
 961         __gss_pipe_free(p);
 962 }
 963
 964 static void gss_pipe_free(struct gss_pipe *p)
 965 {
 966         if (p != NULL)
 967                 kref_put(&p->kref, __gss_pipe_release);
 968 }
 969
 970 /*
 971  * NOTE: we have the opportunity to use different
 972  * parameters based on the input flavor (which must be a pseudoflavor)
 973  */
 974 static struct gss_auth *
 975 gss_create_new(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
 976 {
 977         rpc_authflavor_t flavor = args->pseudoflavor;
 978         struct gss_auth *gss_auth;
 979         struct gss_pipe *gss_pipe;
 980         struct rpc_auth * auth;
 981         int err = -ENOMEM; /* XXX? */
 982
 983         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 984
 985         if (!try_module_get(THIS_MODULE))
 986                 return ERR_PTR(err);
 987         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 988                 goto out_dec;
 989         INIT_HLIST_NODE(&gss_auth->hash);
 990         gss_auth->target_name = NULL;
 991         if (args->target_name) {
 992                 gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
 993                 if (gss_auth->target_name == NULL)
 994                         goto err_free;
 995         }
 996         gss_auth->client = clnt;
 997         gss_auth->net = get_net(rpc_net_ns(clnt));
 998         err = -EINVAL;
 999         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
1000         if (!gss_auth->mech) {
1001                 dprintk("RPC:       Pseudoflavor %d not found!\n", flavor);
1002                 goto err_put_net;
1003         }
1004         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
1005         if (gss_auth->service == 0)
1006                 goto err_put_mech;
1007         if (!gssd_running(gss_auth->net))
1008                 goto err_put_mech;
1009         auth = &gss_auth->rpc_auth;
1010         auth->au_cslack = GSS_CRED_SLACK >> 2;
1011         auth->au_rslack = GSS_VERF_SLACK >> 2;
1012         auth->au_flags = 0;
1013         auth->au_ops = &authgss_ops;
1014         auth->au_flavor = flavor;
1015         if (gss_pseudoflavor_to_datatouch(gss_auth->mech, flavor))
1016                 auth->au_flags |= RPCAUTH_AUTH_DATATOUCH;
1017         atomic_set(&auth->au_count, 1);
1018         kref_init(&gss_auth->kref);
1019
1020         err = rpcauth_init_credcache(auth);
1021         if (err)
1022                 goto err_put_mech;
1023         /*
1024          * Note: if we created the old pipe first, then someone who
1025          * examined the directory at the right moment might conclude
1026          * that we supported only the old pipe.  So we instead create
1027          * the new pipe first.
1028          */
1029         gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
1030         if (IS_ERR(gss_pipe)) {
1031                 err = PTR_ERR(gss_pipe);
1032                 goto err_destroy_credcache;
1033         }
1034         gss_auth->gss_pipe[1] = gss_pipe;
1035
1036         gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
1037                         &gss_upcall_ops_v0);
1038         if (IS_ERR(gss_pipe)) {
1039                 err = PTR_ERR(gss_pipe);
1040                 goto err_destroy_pipe_1;
1041         }
1042         gss_auth->gss_pipe[0] = gss_pipe;
1043
1044         return gss_auth;
1045 err_destroy_pipe_1:
1046         gss_pipe_free(gss_auth->gss_pipe[1]);
1047 err_destroy_credcache:
1048         rpcauth_destroy_credcache(auth);
1049 err_put_mech:
1050         gss_mech_put(gss_auth->mech);
1051 err_put_net:
1052         put_net(gss_auth->net);
1053 err_free:
1054         kfree(gss_auth->target_name);
1055         kfree(gss_auth);
1056 out_dec:
1057         module_put(THIS_MODULE);
1058         return ERR_PTR(err);
1059 }
1060
1061 static void
1062 gss_free(struct gss_auth *gss_auth)
1063 {
1064         gss_pipe_free(gss_auth->gss_pipe[0]);
1065         gss_pipe_free(gss_auth->gss_pipe[1]);
1066         gss_mech_put(gss_auth->mech);
1067         put_net(gss_auth->net);
1068         kfree(gss_auth->target_name);
1069
1070         kfree(gss_auth);
1071         module_put(THIS_MODULE);
1072 }
1073
1074 static void
1075 gss_free_callback(struct kref *kref)
1076 {
1077         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1078
1079         gss_free(gss_auth);
1080 }
1081
1082 static void
1083 gss_put_auth(struct gss_auth *gss_auth)
1084 {
1085         kref_put(&gss_auth->kref, gss_free_callback);
1086 }
1087
1088 static void
1089 gss_destroy(struct rpc_auth *auth)
1090 {
1091         struct gss_auth *gss_auth = container_of(auth,
1092                         struct gss_auth, rpc_auth);
1093
1094         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
1095                         auth, auth->au_flavor);
1096
1097         if (hash_hashed(&gss_auth->hash)) {
1098                 spin_lock(&gss_auth_hash_lock);
1099                 hash_del(&gss_auth->hash);
1100                 spin_unlock(&gss_auth_hash_lock);
1101         }
1102
1103         gss_pipe_free(gss_auth->gss_pipe[0]);
1104         gss_auth->gss_pipe[0] = NULL;
1105         gss_pipe_free(gss_auth->gss_pipe[1]);
1106         gss_auth->gss_pipe[1] = NULL;
1107         rpcauth_destroy_credcache(auth);
1108
1109         gss_put_auth(gss_auth);
1110 }
1111
1112 /*
1113  * Auths may be shared between rpc clients that were cloned from a
1114  * common client with the same xprt, if they also share the flavor and
1115  * target_name.
1116  *
1117  * The auth is looked up from the oldest parent sharing the same
1118  * cl_xprt, and the auth itself references only that common parent
1119  * (which is guaranteed to last as long as any of its descendants).
1120  */
1121 static struct gss_auth *
1122 gss_auth_find_or_add_hashed(struct rpc_auth_create_args *args,
1123                 struct rpc_clnt *clnt,
1124                 struct gss_auth *new)
1125 {
1126         struct gss_auth *gss_auth;
1127         unsigned long hashval = (unsigned long)clnt;
1128
1129         spin_lock(&gss_auth_hash_lock);
1130         hash_for_each_possible(gss_auth_hash_table,
1131                         gss_auth,
1132                         hash,
1133                         hashval) {
1134                 if (gss_auth->client != clnt)
1135                         continue;
1136                 if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1137                         continue;
1138                 if (gss_auth->target_name != args->target_name) {
1139                         if (gss_auth->target_name == NULL)
1140                                 continue;
1141                         if (args->target_name == NULL)
1142                                 continue;
1143                         if (strcmp(gss_auth->target_name, args->target_name))
1144                                 continue;
1145                 }
1146                 if (!atomic_inc_not_zero(&gss_auth->rpc_auth.au_count))
1147                         continue;
1148                 goto out;
1149         }
1150         if (new)
1151                 hash_add(gss_auth_hash_table, &new->hash, hashval);
1152         gss_auth = new;
1153 out:
1154         spin_unlock(&gss_auth_hash_lock);
1155         return gss_auth;
1156 }
1157
1158 static struct gss_auth *
1159 gss_create_hashed(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1160 {
1161         struct gss_auth *gss_auth;
1162         struct gss_auth *new;
1163
1164         gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1165         if (gss_auth != NULL)
1166                 goto out;
1167         new = gss_create_new(args, clnt);
1168         if (IS_ERR(new))
1169                 return new;
1170         gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1171         if (gss_auth != new)
1172                 gss_destroy(&new->rpc_auth);
1173 out:
1174         return gss_auth;
1175 }
1176
1177 static struct rpc_auth *
1178 gss_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1179 {
1180         struct gss_auth *gss_auth;
1181         struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
1182
1183         while (clnt != clnt->cl_parent) {
1184                 struct rpc_clnt *parent = clnt->cl_parent;
1185                 /* Find the original parent for this transport */
1186                 if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
1187                         break;
1188                 clnt = parent;
1189         }
1190
1191         gss_auth = gss_create_hashed(args, clnt);
1192         if (IS_ERR(gss_auth))
1193                 return ERR_CAST(gss_auth);
1194         return &gss_auth->rpc_auth;
1195 }
1196
1197 /*
1198  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
1199  * to the server with the GSS control procedure field set to
1200  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1201  * all RPCSEC_GSS state associated with that context.
1202  */
1203 static int
1204 gss_destroying_context(struct rpc_cred *cred)
1205 {
1206         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1207         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1208         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1209         struct rpc_task *task;
1210
1211         if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
1212                 return 0;
1213
1214         ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1215         cred->cr_ops = &gss_nullops;
1216
1217         /* Take a reference to ensure the cred will be destroyed either
1218          * by the RPC call or by the put_rpccred() below */
1219         get_rpccred(cred);
1220
1221         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
1222         if (!IS_ERR(task))
1223                 rpc_put_task(task);
1224
1225         put_rpccred(cred);
1226         return 1;
1227 }
1228
1229 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1230  * to create a new cred or context, so they check that things have been
1231  * allocated before freeing them. */
1232 static void
1233 gss_do_free_ctx(struct gss_cl_ctx *ctx)
1234 {
1235         dprintk("RPC:       %s\n", __func__);
1236
1237         gss_delete_sec_context(&ctx->gc_gss_ctx);
1238         kfree(ctx->gc_wire_ctx.data);
1239         kfree(ctx->gc_acceptor.data);
1240         kfree(ctx);
1241 }
1242
1243 static void
1244 gss_free_ctx_callback(struct rcu_head *head)
1245 {
1246         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1247         gss_do_free_ctx(ctx);
1248 }
1249
1250 static void
1251 gss_free_ctx(struct gss_cl_ctx *ctx)
1252 {
1253         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1254 }
1255
1256 static void
1257 gss_free_cred(struct gss_cred *gss_cred)
1258 {
1259         dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1260         kfree(gss_cred);
1261 }
1262
1263 static void
1264 gss_free_cred_callback(struct rcu_head *head)
1265 {
1266         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1267         gss_free_cred(gss_cred);
1268 }
1269
1270 static void
1271 gss_destroy_nullcred(struct rpc_cred *cred)
1272 {
1273         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1274         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1275         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1276
1277         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1278         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1279         if (ctx)
1280                 gss_put_ctx(ctx);
1281         gss_put_auth(gss_auth);
1282 }
1283
1284 static void
1285 gss_destroy_cred(struct rpc_cred *cred)
1286 {
1287
1288         if (gss_destroying_context(cred))
1289                 return;
1290         gss_destroy_nullcred(cred);
1291 }
1292
1293 static int
1294 gss_hash_cred(struct auth_cred *acred, unsigned int hashbits)
1295 {
1296         return hash_64(from_kuid(&init_user_ns, acred->uid), hashbits);
1297 }
1298
1299 /*
1300  * Lookup RPCSEC_GSS cred for the current process
1301  */
1302 static struct rpc_cred *
1303 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1304 {
1305         return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS);
1306 }
1307
1308 static struct rpc_cred *
1309 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp)
1310 {
1311         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1312         struct gss_cred *cred = NULL;
1313         int err = -ENOMEM;
1314
1315         dprintk("RPC:       %s for uid %d, flavor %d\n",
1316                 __func__, from_kuid(&init_user_ns, acred->uid),
1317                 auth->au_flavor);
1318
1319         if (!(cred = kzalloc(sizeof(*cred), gfp)))
1320                 goto out_err;
1321
1322         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1323         /*
1324          * Note: in order to force a call to call_refresh(), we deliberately
1325          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1326          */
1327         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1328         cred->gc_service = gss_auth->service;
1329         cred->gc_principal = NULL;
1330         if (acred->machine_cred)
1331                 cred->gc_principal = acred->principal;
1332         kref_get(&gss_auth->kref);
1333         return &cred->gc_base;
1334
1335 out_err:
1336         dprintk("RPC:       %s failed with error %d\n", __func__, err);
1337         return ERR_PTR(err);
1338 }
1339
1340 static int
1341 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1342 {
1343         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1344         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1345         int err;
1346
1347         do {
1348                 err = gss_create_upcall(gss_auth, gss_cred);
1349         } while (err == -EAGAIN);
1350         return err;
1351 }
1352
1353 static char *
1354 gss_stringify_acceptor(struct rpc_cred *cred)
1355 {
1356         char *string = NULL;
1357         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1358         struct gss_cl_ctx *ctx;
1359         unsigned int len;
1360         struct xdr_netobj *acceptor;
1361
1362         rcu_read_lock();
1363         ctx = rcu_dereference(gss_cred->gc_ctx);
1364         if (!ctx)
1365                 goto out;
1366
1367         len = ctx->gc_acceptor.len;
1368         rcu_read_unlock();
1369
1370         /* no point if there's no string */
1371         if (!len)
1372                 return NULL;
1373 realloc:
1374         string = kmalloc(len + 1, GFP_KERNEL);
1375         if (!string)
1376                 return NULL;
1377
1378         rcu_read_lock();
1379         ctx = rcu_dereference(gss_cred->gc_ctx);
1380
1381         /* did the ctx disappear or was it replaced by one with no acceptor? */
1382         if (!ctx || !ctx->gc_acceptor.len) {
1383                 kfree(string);
1384                 string = NULL;
1385                 goto out;
1386         }
1387
1388         acceptor = &ctx->gc_acceptor;
1389
1390         /*
1391          * Did we find a new acceptor that's longer than the original? Allocate
1392          * a longer buffer and try again.
1393          */
1394         if (len < acceptor->len) {
1395                 len = acceptor->len;
1396                 rcu_read_unlock();
1397                 kfree(string);
1398                 goto realloc;
1399         }
1400
1401         memcpy(string, acceptor->data, acceptor->len);
1402         string[acceptor->len] = '\0';
1403 out:
1404         rcu_read_unlock();
1405         return string;
1406 }
1407
1408 /*
1409  * Returns -EACCES if GSS context is NULL or will expire within the
1410  * timeout (miliseconds)
1411  */
1412 static int
1413 gss_key_timeout(struct rpc_cred *rc)
1414 {
1415         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1416         struct gss_cl_ctx *ctx;
1417         unsigned long timeout = jiffies + (gss_key_expire_timeo * HZ);
1418         int ret = 0;
1419
1420         rcu_read_lock();
1421         ctx = rcu_dereference(gss_cred->gc_ctx);
1422         if (!ctx || time_after(timeout, ctx->gc_expiry))
1423                 ret = -EACCES;
1424         rcu_read_unlock();
1425
1426         return ret;
1427 }
1428
1429 static int
1430 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1431 {
1432         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1433         struct gss_cl_ctx *ctx;
1434         int ret;
1435
1436         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1437                 goto out;
1438         /* Don't match with creds that have expired. */
1439         rcu_read_lock();
1440         ctx = rcu_dereference(gss_cred->gc_ctx);
1441         if (!ctx || time_after(jiffies, ctx->gc_expiry)) {
1442                 rcu_read_unlock();
1443                 return 0;
1444         }
1445         rcu_read_unlock();
1446         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1447                 return 0;
1448 out:
1449         if (acred->principal != NULL) {
1450                 if (gss_cred->gc_principal == NULL)
1451                         return 0;
1452                 ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1453                 goto check_expire;
1454         }
1455         if (gss_cred->gc_principal != NULL)
1456                 return 0;
1457         ret = uid_eq(rc->cr_uid, acred->uid);
1458
1459 check_expire:
1460         if (ret == 0)
1461                 return ret;
1462
1463         /* Notify acred users of GSS context expiration timeout */
1464         if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags) &&
1465             (gss_key_timeout(rc) != 0)) {
1466                 /* test will now be done from generic cred */
1467                 test_and_clear_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
1468                 /* tell NFS layer that key will expire soon */
1469                 set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
1470         }
1471         return ret;
1472 }
1473
1474 /*
1475 * Marshal credentials.
1476 * Maybe we should keep a cached credential for performance reasons.
1477 */
1478 static __be32 *
1479 gss_marshal(struct rpc_task *task, __be32 *p)
1480 {
1481         struct rpc_rqst *req = task->tk_rqstp;
1482         struct rpc_cred *cred = req->rq_cred;
1483         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1484                                                  gc_base);
1485         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1486         __be32          *cred_len;
1487         u32             maj_stat = 0;
1488         struct xdr_netobj mic;
1489         struct kvec     iov;
1490         struct xdr_buf  verf_buf;
1491
1492         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1493
1494         *p++ = htonl(RPC_AUTH_GSS);
1495         cred_len = p++;
1496
1497         spin_lock(&ctx->gc_seq_lock);
1498         req->rq_seqno = ctx->gc_seq++;
1499         spin_unlock(&ctx->gc_seq_lock);
1500
1501         *p++ = htonl((u32) RPC_GSS_VERSION);
1502         *p++ = htonl((u32) ctx->gc_proc);
1503         *p++ = htonl((u32) req->rq_seqno);
1504         *p++ = htonl((u32) gss_cred->gc_service);
1505         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1506         *cred_len = htonl((p - (cred_len + 1)) << 2);
1507
1508         /* We compute the checksum for the verifier over the xdr-encoded bytes
1509          * starting with the xid and ending at the end of the credential: */
1510         iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
1511                                         req->rq_snd_buf.head[0].iov_base);
1512         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1513         xdr_buf_from_iov(&iov, &verf_buf);
1514
1515         /* set verifier flavor*/
1516         *p++ = htonl(RPC_AUTH_GSS);
1517
1518         mic.data = (u8 *)(p + 1);
1519         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1520         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1521                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1522         } else if (maj_stat != 0) {
1523                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1524                 goto out_put_ctx;
1525         }
1526         p = xdr_encode_opaque(p, NULL, mic.len);
1527         gss_put_ctx(ctx);
1528         return p;
1529 out_put_ctx:
1530         gss_put_ctx(ctx);
1531         return NULL;
1532 }
1533
1534 static int gss_renew_cred(struct rpc_task *task)
1535 {
1536         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1537         struct gss_cred *gss_cred = container_of(oldcred,
1538                                                  struct gss_cred,
1539                                                  gc_base);
1540         struct rpc_auth *auth = oldcred->cr_auth;
1541         struct auth_cred acred = {
1542                 .uid = oldcred->cr_uid,
1543                 .principal = gss_cred->gc_principal,
1544                 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
1545         };
1546         struct rpc_cred *new;
1547
1548         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1549         if (IS_ERR(new))
1550                 return PTR_ERR(new);
1551         task->tk_rqstp->rq_cred = new;
1552         put_rpccred(oldcred);
1553         return 0;
1554 }
1555
1556 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1557 {
1558         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1559                 unsigned long now = jiffies;
1560                 unsigned long begin, expire;
1561                 struct gss_cred *gss_cred;
1562
1563                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1564                 begin = gss_cred->gc_upcall_timestamp;
1565                 expire = begin + gss_expired_cred_retry_delay * HZ;
1566
1567                 if (time_in_range_open(now, begin, expire))
1568                         return 1;
1569         }
1570         return 0;
1571 }
1572
1573 /*
1574 * Refresh credentials. XXX - finish
1575 */
1576 static int
1577 gss_refresh(struct rpc_task *task)
1578 {
1579         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1580         int ret = 0;
1581
1582         if (gss_cred_is_negative_entry(cred))
1583                 return -EKEYEXPIRED;
1584
1585         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1586                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1587                 ret = gss_renew_cred(task);
1588                 if (ret < 0)
1589                         goto out;
1590                 cred = task->tk_rqstp->rq_cred;
1591         }
1592
1593         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1594                 ret = gss_refresh_upcall(task);
1595 out:
1596         return ret;
1597 }
1598
1599 /* Dummy refresh routine: used only when destroying the context */
1600 static int
1601 gss_refresh_null(struct rpc_task *task)
1602 {
1603         return 0;
1604 }
1605
1606 static __be32 *
1607 gss_validate(struct rpc_task *task, __be32 *p)
1608 {
1609         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1610         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1611         __be32          *seq = NULL;
1612         struct kvec     iov;
1613         struct xdr_buf  verf_buf;
1614         struct xdr_netobj mic;
1615         u32             flav,len;
1616         u32             maj_stat;
1617         __be32          *ret = ERR_PTR(-EIO);
1618
1619         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1620
1621         flav = ntohl(*p++);
1622         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1623                 goto out_bad;
1624         if (flav != RPC_AUTH_GSS)
1625                 goto out_bad;
1626         seq = kmalloc(4, GFP_NOFS);
1627         if (!seq)
1628                 goto out_bad;
1629         *seq = htonl(task->tk_rqstp->rq_seqno);
1630         iov.iov_base = seq;
1631         iov.iov_len = 4;
1632         xdr_buf_from_iov(&iov, &verf_buf);
1633         mic.data = (u8 *)p;
1634         mic.len = len;
1635
1636         ret = ERR_PTR(-EACCES);
1637         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1638         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1639                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1640         if (maj_stat) {
1641                 dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1642                         task->tk_pid, __func__, maj_stat);
1643                 goto out_bad;
1644         }
1645         /* We leave it to unwrap to calculate au_rslack. For now we just
1646          * calculate the length of the verifier: */
1647         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1648         gss_put_ctx(ctx);
1649         dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1650                         task->tk_pid, __func__);
1651         kfree(seq);
1652         return p + XDR_QUADLEN(len);
1653 out_bad:
1654         gss_put_ctx(ctx);
1655         dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
1656                 PTR_ERR(ret));
1657         kfree(seq);
1658         return ret;
1659 }
1660
1661 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1662                                 __be32 *p, void *obj)
1663 {
1664         struct xdr_stream xdr;
1665
1666         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1667         encode(rqstp, &xdr, obj);
1668 }
1669
1670 static inline int
1671 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1672                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1673                    __be32 *p, void *obj)
1674 {
1675         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1676         struct xdr_buf  integ_buf;
1677         __be32          *integ_len = NULL;
1678         struct xdr_netobj mic;
1679         u32             offset;
1680         __be32          *q;
1681         struct kvec     *iov;
1682         u32             maj_stat = 0;
1683         int             status = -EIO;
1684
1685         integ_len = p++;
1686         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1687         *p++ = htonl(rqstp->rq_seqno);
1688
1689         gss_wrap_req_encode(encode, rqstp, p, obj);
1690
1691         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1692                                 offset, snd_buf->len - offset))
1693                 return status;
1694         *integ_len = htonl(integ_buf.len);
1695
1696         /* guess whether we're in the head or the tail: */
1697         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1698                 iov = snd_buf->tail;
1699         else
1700                 iov = snd_buf->head;
1701         p = iov->iov_base + iov->iov_len;
1702         mic.data = (u8 *)(p + 1);
1703
1704         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1705         status = -EIO; /* XXX? */
1706         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1707                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1708         else if (maj_stat)
1709                 return status;
1710         q = xdr_encode_opaque(p, NULL, mic.len);
1711
1712         offset = (u8 *)q - (u8 *)p;
1713         iov->iov_len += offset;
1714         snd_buf->len += offset;
1715         return 0;
1716 }
1717
1718 static void
1719 priv_release_snd_buf(struct rpc_rqst *rqstp)
1720 {
1721         int i;
1722
1723         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1724                 __free_page(rqstp->rq_enc_pages[i]);
1725         kfree(rqstp->rq_enc_pages);
1726         rqstp->rq_release_snd_buf = NULL;
1727 }
1728
1729 static int
1730 alloc_enc_pages(struct rpc_rqst *rqstp)
1731 {
1732         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1733         int first, last, i;
1734
1735         if (rqstp->rq_release_snd_buf)
1736                 rqstp->rq_release_snd_buf(rqstp);
1737
1738         if (snd_buf->page_len == 0) {
1739                 rqstp->rq_enc_pages_num = 0;
1740                 return 0;
1741         }
1742
1743         first = snd_buf->page_base >> PAGE_SHIFT;
1744         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_SHIFT;
1745         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1746         rqstp->rq_enc_pages
1747                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1748                                 GFP_NOFS);
1749         if (!rqstp->rq_enc_pages)
1750                 goto out;
1751         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1752                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1753                 if (rqstp->rq_enc_pages[i] == NULL)
1754                         goto out_free;
1755         }
1756         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1757         return 0;
1758 out_free:
1759         rqstp->rq_enc_pages_num = i;
1760         priv_release_snd_buf(rqstp);
1761 out:
1762         return -EAGAIN;
1763 }
1764
1765 static inline int
1766 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1767                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1768                   __be32 *p, void *obj)
1769 {
1770         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1771         u32             offset;
1772         u32             maj_stat;
1773         int             status;
1774         __be32          *opaque_len;
1775         struct page     **inpages;
1776         int             first;
1777         int             pad;
1778         struct kvec     *iov;
1779         char            *tmp;
1780
1781         opaque_len = p++;
1782         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1783         *p++ = htonl(rqstp->rq_seqno);
1784
1785         gss_wrap_req_encode(encode, rqstp, p, obj);
1786
1787         status = alloc_enc_pages(rqstp);
1788         if (status)
1789                 return status;
1790         first = snd_buf->page_base >> PAGE_SHIFT;
1791         inpages = snd_buf->pages + first;
1792         snd_buf->pages = rqstp->rq_enc_pages;
1793         snd_buf->page_base -= first << PAGE_SHIFT;
1794         /*
1795          * Give the tail its own page, in case we need extra space in the
1796          * head when wrapping:
1797          *
1798          * call_allocate() allocates twice the slack space required
1799          * by the authentication flavor to rq_callsize.
1800          * For GSS, slack is GSS_CRED_SLACK.
1801          */
1802         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1803                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1804                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1805                 snd_buf->tail[0].iov_base = tmp;
1806         }
1807         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1808         /* slack space should prevent this ever happening: */
1809         BUG_ON(snd_buf->len > snd_buf->buflen);
1810         status = -EIO;
1811         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1812          * done anyway, so it's safe to put the request on the wire: */
1813         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1814                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1815         else if (maj_stat)
1816                 return status;
1817
1818         *opaque_len = htonl(snd_buf->len - offset);
1819         /* guess whether we're in the head or the tail: */
1820         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1821                 iov = snd_buf->tail;
1822         else
1823                 iov = snd_buf->head;
1824         p = iov->iov_base + iov->iov_len;
1825         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1826         memset(p, 0, pad);
1827         iov->iov_len += pad;
1828         snd_buf->len += pad;
1829
1830         return 0;
1831 }
1832
1833 static int
1834 gss_wrap_req(struct rpc_task *task,
1835              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1836 {
1837         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1838         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1839                         gc_base);
1840         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1841         int             status = -EIO;
1842
1843         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1844         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1845                 /* The spec seems a little ambiguous here, but I think that not
1846                  * wrapping context destruction requests makes the most sense.
1847                  */
1848                 gss_wrap_req_encode(encode, rqstp, p, obj);
1849                 status = 0;
1850                 goto out;
1851         }
1852         switch (gss_cred->gc_service) {
1853         case RPC_GSS_SVC_NONE:
1854                 gss_wrap_req_encode(encode, rqstp, p, obj);
1855                 status = 0;
1856                 break;
1857         case RPC_GSS_SVC_INTEGRITY:
1858                 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1859                 break;
1860         case RPC_GSS_SVC_PRIVACY:
1861                 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1862                 break;
1863         }
1864 out:
1865         gss_put_ctx(ctx);
1866         dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1867         return status;
1868 }
1869
1870 static inline int
1871 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1872                 struct rpc_rqst *rqstp, __be32 **p)
1873 {
1874         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1875         struct xdr_buf integ_buf;
1876         struct xdr_netobj mic;
1877         u32 data_offset, mic_offset;
1878         u32 integ_len;
1879         u32 maj_stat;
1880         int status = -EIO;
1881
1882         integ_len = ntohl(*(*p)++);
1883         if (integ_len & 3)
1884                 return status;
1885         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1886         mic_offset = integ_len + data_offset;
1887         if (mic_offset > rcv_buf->len)
1888                 return status;
1889         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1890                 return status;
1891
1892         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1893                                 mic_offset - data_offset))
1894                 return status;
1895
1896         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1897                 return status;
1898
1899         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1900         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1901                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1902         if (maj_stat != GSS_S_COMPLETE)
1903                 return status;
1904         return 0;
1905 }
1906
1907 static inline int
1908 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1909                 struct rpc_rqst *rqstp, __be32 **p)
1910 {
1911         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1912         u32 offset;
1913         u32 opaque_len;
1914         u32 maj_stat;
1915         int status = -EIO;
1916
1917         opaque_len = ntohl(*(*p)++);
1918         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1919         if (offset + opaque_len > rcv_buf->len)
1920                 return status;
1921         /* remove padding: */
1922         rcv_buf->len = offset + opaque_len;
1923
1924         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1925         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1926                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1927         if (maj_stat != GSS_S_COMPLETE)
1928                 return status;
1929         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1930                 return status;
1931
1932         return 0;
1933 }
1934
1935 static int
1936 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1937                       __be32 *p, void *obj)
1938 {
1939         struct xdr_stream xdr;
1940
1941         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1942         return decode(rqstp, &xdr, obj);
1943 }
1944
1945 static int
1946 gss_unwrap_resp(struct rpc_task *task,
1947                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1948 {
1949         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1950         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1951                         gc_base);
1952         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1953         __be32          *savedp = p;
1954         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1955         int             savedlen = head->iov_len;
1956         int             status = -EIO;
1957
1958         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1959                 goto out_decode;
1960         switch (gss_cred->gc_service) {
1961         case RPC_GSS_SVC_NONE:
1962                 break;
1963         case RPC_GSS_SVC_INTEGRITY:
1964                 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1965                 if (status)
1966                         goto out;
1967                 break;
1968         case RPC_GSS_SVC_PRIVACY:
1969                 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1970                 if (status)
1971                         goto out;
1972                 break;
1973         }
1974         /* take into account extra slack for integrity and privacy cases: */
1975         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1976                                                 + (savedlen - head->iov_len);
1977 out_decode:
1978         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
1979 out:
1980         gss_put_ctx(ctx);
1981         dprintk("RPC: %5u %s returning %d\n",
1982                 task->tk_pid, __func__, status);
1983         return status;
1984 }
1985
1986 static const struct rpc_authops authgss_ops = {
1987         .owner          = THIS_MODULE,
1988         .au_flavor      = RPC_AUTH_GSS,
1989         .au_name        = "RPCSEC_GSS",
1990         .create         = gss_create,
1991         .destroy        = gss_destroy,
1992         .hash_cred      = gss_hash_cred,
1993         .lookup_cred    = gss_lookup_cred,
1994         .crcreate       = gss_create_cred,
1995         .list_pseudoflavors = gss_mech_list_pseudoflavors,
1996         .info2flavor    = gss_mech_info2flavor,
1997         .flavor2info    = gss_mech_flavor2info,
1998 };
1999
2000 static const struct rpc_credops gss_credops = {
2001         .cr_name                = "AUTH_GSS",
2002         .crdestroy              = gss_destroy_cred,
2003         .cr_init                = gss_cred_init,
2004         .crbind                 = rpcauth_generic_bind_cred,
2005         .crmatch                = gss_match,
2006         .crmarshal              = gss_marshal,
2007         .crrefresh              = gss_refresh,
2008         .crvalidate             = gss_validate,
2009         .crwrap_req             = gss_wrap_req,
2010         .crunwrap_resp          = gss_unwrap_resp,
2011         .crkey_timeout          = gss_key_timeout,
2012         .crstringify_acceptor   = gss_stringify_acceptor,
2013 };
2014
2015 static const struct rpc_credops gss_nullops = {
2016         .cr_name                = "AUTH_GSS",
2017         .crdestroy              = gss_destroy_nullcred,
2018         .crbind                 = rpcauth_generic_bind_cred,
2019         .crmatch                = gss_match,
2020         .crmarshal              = gss_marshal,
2021         .crrefresh              = gss_refresh_null,
2022         .crvalidate             = gss_validate,
2023         .crwrap_req             = gss_wrap_req,
2024         .crunwrap_resp          = gss_unwrap_resp,
2025         .crstringify_acceptor   = gss_stringify_acceptor,
2026 };
2027
2028 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
2029         .upcall         = rpc_pipe_generic_upcall,
2030         .downcall       = gss_pipe_downcall,
2031         .destroy_msg    = gss_pipe_destroy_msg,
2032         .open_pipe      = gss_pipe_open_v0,
2033         .release_pipe   = gss_pipe_release,
2034 };
2035
2036 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
2037         .upcall         = rpc_pipe_generic_upcall,
2038         .downcall       = gss_pipe_downcall,
2039         .destroy_msg    = gss_pipe_destroy_msg,
2040         .open_pipe      = gss_pipe_open_v1,
2041         .release_pipe   = gss_pipe_release,
2042 };
2043
2044 static __net_init int rpcsec_gss_init_net(struct net *net)
2045 {
2046         return gss_svc_init_net(net);
2047 }
2048
2049 static __net_exit void rpcsec_gss_exit_net(struct net *net)
2050 {
2051         gss_svc_shutdown_net(net);
2052 }
2053
2054 static struct pernet_operations rpcsec_gss_net_ops = {
2055         .init = rpcsec_gss_init_net,
2056         .exit = rpcsec_gss_exit_net,
2057 };
2058
2059 /*
2060  * Initialize RPCSEC_GSS module
2061  */
2062 static int __init init_rpcsec_gss(void)
2063 {
2064         int err = 0;
2065
2066         err = rpcauth_register(&authgss_ops);
2067         if (err)
2068                 goto out;
2069         err = gss_svc_init();
2070         if (err)
2071                 goto out_unregister;
2072         err = register_pernet_subsys(&rpcsec_gss_net_ops);
2073         if (err)
2074                 goto out_svc_exit;
2075         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
2076         return 0;
2077 out_svc_exit:
2078         gss_svc_shutdown();
2079 out_unregister:
2080         rpcauth_unregister(&authgss_ops);
2081 out:
2082         return err;
2083 }
2084
2085 static void __exit exit_rpcsec_gss(void)
2086 {
2087         unregister_pernet_subsys(&rpcsec_gss_net_ops);
2088         gss_svc_shutdown();
2089         rpcauth_unregister(&authgss_ops);
2090         rcu_barrier(); /* Wait for completion of call_rcu()'s */
2091 }
2092
2093 MODULE_ALIAS("rpc-auth-6");
2094 MODULE_LICENSE("GPL");
2095 module_param_named(expired_cred_retry_delay,
2096                    gss_expired_cred_retry_delay,
2097                    uint, 0644);
2098 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
2099                 "the RPC engine retries an expired credential");
2100
2101 module_param_named(key_expire_timeo,
2102                    gss_key_expire_timeo,
2103                    uint, 0644);
2104 MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
2105                 "credential keys lifetime where the NFS layer cleans up "
2106                 "prior to key expiration");
2107
2108 module_init(init_rpcsec_gss)
2109 module_exit(exit_rpcsec_gss)