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