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