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         static unsigned long ratelimit;
 536         unsigned long now = jiffies;
 537
 538         if (time_after(now, ratelimit)) {
 539                 pr_warn("RPC: AUTH_GSS upcall failed. Please check user daemon is running.\n");
 540                 ratelimit = now + 15*HZ;
 541         }
 542 }
 543
 544 static inline int
 545 gss_refresh_upcall(struct rpc_task *task)
 546 {
 547         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 548         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 549                         struct gss_auth, rpc_auth);
 550         struct gss_cred *gss_cred = container_of(cred,
 551                         struct gss_cred, gc_base);
 552         struct gss_upcall_msg *gss_msg;
 553         struct rpc_pipe *pipe;
 554         int err = 0;
 555
 556         dprintk("RPC: %5u %s for uid %u\n",
 557                 task->tk_pid, __func__, from_kuid(&init_user_ns, cred->cr_uid));
 558         gss_msg = gss_setup_upcall(gss_auth, cred);
 559         if (PTR_ERR(gss_msg) == -EAGAIN) {
 560                 /* XXX: warning on the first, under the assumption we
 561                  * shouldn't normally hit this case on a refresh. */
 562                 warn_gssd();
 563                 task->tk_timeout = 15*HZ;
 564                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
 565                 return -EAGAIN;
 566         }
 567         if (IS_ERR(gss_msg)) {
 568                 err = PTR_ERR(gss_msg);
 569                 goto out;
 570         }
 571         pipe = gss_msg->pipe;
 572         spin_lock(&pipe->lock);
 573         if (gss_cred->gc_upcall != NULL)
 574                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 575         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 576                 task->tk_timeout = 0;
 577                 gss_cred->gc_upcall = gss_msg;
 578                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 579                 atomic_inc(&gss_msg->count);
 580                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 581         } else {
 582                 gss_handle_downcall_result(gss_cred, gss_msg);
 583                 err = gss_msg->msg.errno;
 584         }
 585         spin_unlock(&pipe->lock);
 586         gss_release_msg(gss_msg);
 587 out:
 588         dprintk("RPC: %5u %s for uid %u result %d\n",
 589                 task->tk_pid, __func__,
 590                 from_kuid(&init_user_ns, cred->cr_uid), err);
 591         return err;
 592 }
 593
 594 static inline int
 595 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 596 {
 597         struct net *net = gss_auth->net;
 598         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 599         struct rpc_pipe *pipe;
 600         struct rpc_cred *cred = &gss_cred->gc_base;
 601         struct gss_upcall_msg *gss_msg;
 602         DEFINE_WAIT(wait);
 603         int err;
 604
 605         dprintk("RPC:       %s for uid %u\n",
 606                 __func__, from_kuid(&init_user_ns, cred->cr_uid));
 607 retry:
 608         err = 0;
 609         /* if gssd is down, just skip upcalling altogether */
 610         if (!gssd_running(net)) {
 611                 warn_gssd();
 612                 return -EACCES;
 613         }
 614         gss_msg = gss_setup_upcall(gss_auth, cred);
 615         if (PTR_ERR(gss_msg) == -EAGAIN) {
 616                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
 617                                 sn->pipe_version >= 0, 15 * HZ);
 618                 if (sn->pipe_version < 0) {
 619                         warn_gssd();
 620                         err = -EACCES;
 621                 }
 622                 if (err < 0)
 623                         goto out;
 624                 goto retry;
 625         }
 626         if (IS_ERR(gss_msg)) {
 627                 err = PTR_ERR(gss_msg);
 628                 goto out;
 629         }
 630         pipe = gss_msg->pipe;
 631         for (;;) {
 632                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
 633                 spin_lock(&pipe->lock);
 634                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 635                         break;
 636                 }
 637                 spin_unlock(&pipe->lock);
 638                 if (fatal_signal_pending(current)) {
 639                         err = -ERESTARTSYS;
 640                         goto out_intr;
 641                 }
 642                 schedule();
 643         }
 644         if (gss_msg->ctx)
 645                 gss_cred_set_ctx(cred, gss_msg->ctx);
 646         else
 647                 err = gss_msg->msg.errno;
 648         spin_unlock(&pipe->lock);
 649 out_intr:
 650         finish_wait(&gss_msg->waitqueue, &wait);
 651         gss_release_msg(gss_msg);
 652 out:
 653         dprintk("RPC:       %s for uid %u result %d\n",
 654                 __func__, from_kuid(&init_user_ns, cred->cr_uid), err);
 655         return err;
 656 }
 657
 658 #define MSG_BUF_MAXSIZE 1024
 659
 660 static ssize_t
 661 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 662 {
 663         const void *p, *end;
 664         void *buf;
 665         struct gss_upcall_msg *gss_msg;
 666         struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
 667         struct gss_cl_ctx *ctx;
 668         uid_t id;
 669         kuid_t uid;
 670         ssize_t err = -EFBIG;
 671
 672         if (mlen > MSG_BUF_MAXSIZE)
 673                 goto out;
 674         err = -ENOMEM;
 675         buf = kmalloc(mlen, GFP_NOFS);
 676         if (!buf)
 677                 goto out;
 678
 679         err = -EFAULT;
 680         if (copy_from_user(buf, src, mlen))
 681                 goto err;
 682
 683         end = (const void *)((char *)buf + mlen);
 684         p = simple_get_bytes(buf, end, &id, sizeof(id));
 685         if (IS_ERR(p)) {
 686                 err = PTR_ERR(p);
 687                 goto err;
 688         }
 689
 690         uid = make_kuid(&init_user_ns, id);
 691         if (!uid_valid(uid)) {
 692                 err = -EINVAL;
 693                 goto err;
 694         }
 695
 696         err = -ENOMEM;
 697         ctx = gss_alloc_context();
 698         if (ctx == NULL)
 699                 goto err;
 700
 701         err = -ENOENT;
 702         /* Find a matching upcall */
 703         spin_lock(&pipe->lock);
 704         gss_msg = __gss_find_upcall(pipe, uid);
 705         if (gss_msg == NULL) {
 706                 spin_unlock(&pipe->lock);
 707                 goto err_put_ctx;
 708         }
 709         list_del_init(&gss_msg->list);
 710         spin_unlock(&pipe->lock);
 711
 712         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 713         if (IS_ERR(p)) {
 714                 err = PTR_ERR(p);
 715                 switch (err) {
 716                 case -EACCES:
 717                 case -EKEYEXPIRED:
 718                         gss_msg->msg.errno = err;
 719                         err = mlen;
 720                         break;
 721                 case -EFAULT:
 722                 case -ENOMEM:
 723                 case -EINVAL:
 724                 case -ENOSYS:
 725                         gss_msg->msg.errno = -EAGAIN;
 726                         break;
 727                 default:
 728                         printk(KERN_CRIT "%s: bad return from "
 729                                 "gss_fill_context: %zd\n", __func__, err);
 730                         BUG();
 731                 }
 732                 goto err_release_msg;
 733         }
 734         gss_msg->ctx = gss_get_ctx(ctx);
 735         err = mlen;
 736
 737 err_release_msg:
 738         spin_lock(&pipe->lock);
 739         __gss_unhash_msg(gss_msg);
 740         spin_unlock(&pipe->lock);
 741         gss_release_msg(gss_msg);
 742 err_put_ctx:
 743         gss_put_ctx(ctx);
 744 err:
 745         kfree(buf);
 746 out:
 747         dprintk("RPC:       %s returning %Zd\n", __func__, err);
 748         return err;
 749 }
 750
 751 static int gss_pipe_open(struct inode *inode, int new_version)
 752 {
 753         struct net *net = inode->i_sb->s_fs_info;
 754         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 755         int ret = 0;
 756
 757         spin_lock(&pipe_version_lock);
 758         if (sn->pipe_version < 0) {
 759                 /* First open of any gss pipe determines the version: */
 760                 sn->pipe_version = new_version;
 761                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 762                 wake_up(&pipe_version_waitqueue);
 763         } else if (sn->pipe_version != new_version) {
 764                 /* Trying to open a pipe of a different version */
 765                 ret = -EBUSY;
 766                 goto out;
 767         }
 768         atomic_inc(&sn->pipe_users);
 769 out:
 770         spin_unlock(&pipe_version_lock);
 771         return ret;
 772
 773 }
 774
 775 static int gss_pipe_open_v0(struct inode *inode)
 776 {
 777         return gss_pipe_open(inode, 0);
 778 }
 779
 780 static int gss_pipe_open_v1(struct inode *inode)
 781 {
 782         return gss_pipe_open(inode, 1);
 783 }
 784
 785 static void
 786 gss_pipe_release(struct inode *inode)
 787 {
 788         struct net *net = inode->i_sb->s_fs_info;
 789         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 790         struct gss_upcall_msg *gss_msg;
 791
 792 restart:
 793         spin_lock(&pipe->lock);
 794         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
 795
 796                 if (!list_empty(&gss_msg->msg.list))
 797                         continue;
 798                 gss_msg->msg.errno = -EPIPE;
 799                 atomic_inc(&gss_msg->count);
 800                 __gss_unhash_msg(gss_msg);
 801                 spin_unlock(&pipe->lock);
 802                 gss_release_msg(gss_msg);
 803                 goto restart;
 804         }
 805         spin_unlock(&pipe->lock);
 806
 807         put_pipe_version(net);
 808 }
 809
 810 static void
 811 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 812 {
 813         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 814
 815         if (msg->errno < 0) {
 816                 dprintk("RPC:       %s releasing msg %p\n",
 817                         __func__, gss_msg);
 818                 atomic_inc(&gss_msg->count);
 819                 gss_unhash_msg(gss_msg);
 820                 if (msg->errno == -ETIMEDOUT)
 821                         warn_gssd();
 822                 gss_release_msg(gss_msg);
 823         }
 824 }
 825
 826 static void gss_pipe_dentry_destroy(struct dentry *dir,
 827                 struct rpc_pipe_dir_object *pdo)
 828 {
 829         struct gss_pipe *gss_pipe = pdo->pdo_data;
 830         struct rpc_pipe *pipe = gss_pipe->pipe;
 831
 832         if (pipe->dentry != NULL) {
 833                 rpc_unlink(pipe->dentry);
 834                 pipe->dentry = NULL;
 835         }
 836 }
 837
 838 static int gss_pipe_dentry_create(struct dentry *dir,
 839                 struct rpc_pipe_dir_object *pdo)
 840 {
 841         struct gss_pipe *p = pdo->pdo_data;
 842         struct dentry *dentry;
 843
 844         dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
 845         if (IS_ERR(dentry))
 846                 return PTR_ERR(dentry);
 847         p->pipe->dentry = dentry;
 848         return 0;
 849 }
 850
 851 static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
 852         .create = gss_pipe_dentry_create,
 853         .destroy = gss_pipe_dentry_destroy,
 854 };
 855
 856 static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
 857                 const char *name,
 858                 const struct rpc_pipe_ops *upcall_ops)
 859 {
 860         struct gss_pipe *p;
 861         int err = -ENOMEM;
 862
 863         p = kmalloc(sizeof(*p), GFP_KERNEL);
 864         if (p == NULL)
 865                 goto err;
 866         p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 867         if (IS_ERR(p->pipe)) {
 868                 err = PTR_ERR(p->pipe);
 869                 goto err_free_gss_pipe;
 870         }
 871         p->name = name;
 872         p->clnt = clnt;
 873         kref_init(&p->kref);
 874         rpc_init_pipe_dir_object(&p->pdo,
 875                         &gss_pipe_dir_object_ops,
 876                         p);
 877         return p;
 878 err_free_gss_pipe:
 879         kfree(p);
 880 err:
 881         return ERR_PTR(err);
 882 }
 883
 884 struct gss_alloc_pdo {
 885         struct rpc_clnt *clnt;
 886         const char *name;
 887         const struct rpc_pipe_ops *upcall_ops;
 888 };
 889
 890 static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
 891 {
 892         struct gss_pipe *gss_pipe;
 893         struct gss_alloc_pdo *args = data;
 894
 895         if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
 896                 return 0;
 897         gss_pipe = container_of(pdo, struct gss_pipe, pdo);
 898         if (strcmp(gss_pipe->name, args->name) != 0)
 899                 return 0;
 900         if (!kref_get_unless_zero(&gss_pipe->kref))
 901                 return 0;
 902         return 1;
 903 }
 904
 905 static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
 906 {
 907         struct gss_pipe *gss_pipe;
 908         struct gss_alloc_pdo *args = data;
 909
 910         gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
 911         if (!IS_ERR(gss_pipe))
 912                 return &gss_pipe->pdo;
 913         return NULL;
 914 }
 915
 916 static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
 917                 const char *name,
 918                 const struct rpc_pipe_ops *upcall_ops)
 919 {
 920         struct net *net = rpc_net_ns(clnt);
 921         struct rpc_pipe_dir_object *pdo;
 922         struct gss_alloc_pdo args = {
 923                 .clnt = clnt,
 924                 .name = name,
 925                 .upcall_ops = upcall_ops,
 926         };
 927
 928         pdo = rpc_find_or_alloc_pipe_dir_object(net,
 929                         &clnt->cl_pipedir_objects,
 930                         gss_pipe_match_pdo,
 931                         gss_pipe_alloc_pdo,
 932                         &args);
 933         if (pdo != NULL)
 934                 return container_of(pdo, struct gss_pipe, pdo);
 935         return ERR_PTR(-ENOMEM);
 936 }
 937
 938 static void __gss_pipe_free(struct gss_pipe *p)
 939 {
 940         struct rpc_clnt *clnt = p->clnt;
 941         struct net *net = rpc_net_ns(clnt);
 942
 943         rpc_remove_pipe_dir_object(net,
 944                         &clnt->cl_pipedir_objects,
 945                         &p->pdo);
 946         rpc_destroy_pipe_data(p->pipe);
 947         kfree(p);
 948 }
 949
 950 static void __gss_pipe_release(struct kref *kref)
 951 {
 952         struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
 953
 954         __gss_pipe_free(p);
 955 }
 956
 957 static void gss_pipe_free(struct gss_pipe *p)
 958 {
 959         if (p != NULL)
 960                 kref_put(&p->kref, __gss_pipe_release);
 961 }
 962
 963 /*
 964  * NOTE: we have the opportunity to use different
 965  * parameters based on the input flavor (which must be a pseudoflavor)
 966  */
 967 static struct gss_auth *
 968 gss_create_new(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
 969 {
 970         rpc_authflavor_t flavor = args->pseudoflavor;
 971         struct gss_auth *gss_auth;
 972         struct gss_pipe *gss_pipe;
 973         struct rpc_auth * auth;
 974         int err = -ENOMEM; /* XXX? */
 975
 976         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 977
 978         if (!try_module_get(THIS_MODULE))
 979                 return ERR_PTR(err);
 980         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 981                 goto out_dec;
 982         INIT_HLIST_NODE(&gss_auth->hash);
 983         gss_auth->target_name = NULL;
 984         if (args->target_name) {
 985                 gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
 986                 if (gss_auth->target_name == NULL)
 987                         goto err_free;
 988         }
 989         gss_auth->client = clnt;
 990         gss_auth->net = get_net(rpc_net_ns(clnt));
 991         err = -EINVAL;
 992         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 993         if (!gss_auth->mech) {
 994                 dprintk("RPC:       Pseudoflavor %d not found!\n", flavor);
 995                 goto err_put_net;
 996         }
 997         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 998         if (gss_auth->service == 0)
 999                 goto err_put_mech;
1000         auth = &gss_auth->rpc_auth;
1001         auth->au_cslack = GSS_CRED_SLACK >> 2;
1002         auth->au_rslack = GSS_VERF_SLACK >> 2;
1003         auth->au_ops = &authgss_ops;
1004         auth->au_flavor = flavor;
1005         atomic_set(&auth->au_count, 1);
1006         kref_init(&gss_auth->kref);
1007
1008         err = rpcauth_init_credcache(auth);
1009         if (err)
1010                 goto err_put_mech;
1011         /*
1012          * Note: if we created the old pipe first, then someone who
1013          * examined the directory at the right moment might conclude
1014          * that we supported only the old pipe.  So we instead create
1015          * the new pipe first.
1016          */
1017         gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
1018         if (IS_ERR(gss_pipe)) {
1019                 err = PTR_ERR(gss_pipe);
1020                 goto err_destroy_credcache;
1021         }
1022         gss_auth->gss_pipe[1] = gss_pipe;
1023
1024         gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
1025                         &gss_upcall_ops_v0);
1026         if (IS_ERR(gss_pipe)) {
1027                 err = PTR_ERR(gss_pipe);
1028                 goto err_destroy_pipe_1;
1029         }
1030         gss_auth->gss_pipe[0] = gss_pipe;
1031
1032         return gss_auth;
1033 err_destroy_pipe_1:
1034         gss_pipe_free(gss_auth->gss_pipe[1]);
1035 err_destroy_credcache:
1036         rpcauth_destroy_credcache(auth);
1037 err_put_mech:
1038         gss_mech_put(gss_auth->mech);
1039 err_put_net:
1040         put_net(gss_auth->net);
1041 err_free:
1042         kfree(gss_auth->target_name);
1043         kfree(gss_auth);
1044 out_dec:
1045         module_put(THIS_MODULE);
1046         return ERR_PTR(err);
1047 }
1048
1049 static void
1050 gss_free(struct gss_auth *gss_auth)
1051 {
1052         gss_pipe_free(gss_auth->gss_pipe[0]);
1053         gss_pipe_free(gss_auth->gss_pipe[1]);
1054         gss_mech_put(gss_auth->mech);
1055         put_net(gss_auth->net);
1056         kfree(gss_auth->target_name);
1057
1058         kfree(gss_auth);
1059         module_put(THIS_MODULE);
1060 }
1061
1062 static void
1063 gss_free_callback(struct kref *kref)
1064 {
1065         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1066
1067         gss_free(gss_auth);
1068 }
1069
1070 static void
1071 gss_destroy(struct rpc_auth *auth)
1072 {
1073         struct gss_auth *gss_auth = container_of(auth,
1074                         struct gss_auth, rpc_auth);
1075
1076         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
1077                         auth, auth->au_flavor);
1078
1079         if (hash_hashed(&gss_auth->hash)) {
1080                 spin_lock(&gss_auth_hash_lock);
1081                 hash_del(&gss_auth->hash);
1082                 spin_unlock(&gss_auth_hash_lock);
1083         }
1084
1085         gss_pipe_free(gss_auth->gss_pipe[0]);
1086         gss_auth->gss_pipe[0] = NULL;
1087         gss_pipe_free(gss_auth->gss_pipe[1]);
1088         gss_auth->gss_pipe[1] = NULL;
1089         rpcauth_destroy_credcache(auth);
1090
1091         kref_put(&gss_auth->kref, gss_free_callback);
1092 }
1093
1094 /*
1095  * Auths may be shared between rpc clients that were cloned from a
1096  * common client with the same xprt, if they also share the flavor and
1097  * target_name.
1098  *
1099  * The auth is looked up from the oldest parent sharing the same
1100  * cl_xprt, and the auth itself references only that common parent
1101  * (which is guaranteed to last as long as any of its descendants).
1102  */
1103 static struct gss_auth *
1104 gss_auth_find_or_add_hashed(struct rpc_auth_create_args *args,
1105                 struct rpc_clnt *clnt,
1106                 struct gss_auth *new)
1107 {
1108         struct gss_auth *gss_auth;
1109         unsigned long hashval = (unsigned long)clnt;
1110
1111         spin_lock(&gss_auth_hash_lock);
1112         hash_for_each_possible(gss_auth_hash_table,
1113                         gss_auth,
1114                         hash,
1115                         hashval) {
1116                 if (gss_auth->client != clnt)
1117                         continue;
1118                 if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1119                         continue;
1120                 if (gss_auth->target_name != args->target_name) {
1121                         if (gss_auth->target_name == NULL)
1122                                 continue;
1123                         if (args->target_name == NULL)
1124                                 continue;
1125                         if (strcmp(gss_auth->target_name, args->target_name))
1126                                 continue;
1127                 }
1128                 if (!atomic_inc_not_zero(&gss_auth->rpc_auth.au_count))
1129                         continue;
1130                 goto out;
1131         }
1132         if (new)
1133                 hash_add(gss_auth_hash_table, &new->hash, hashval);
1134         gss_auth = new;
1135 out:
1136         spin_unlock(&gss_auth_hash_lock);
1137         return gss_auth;
1138 }
1139
1140 static struct gss_auth *
1141 gss_create_hashed(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1142 {
1143         struct gss_auth *gss_auth;
1144         struct gss_auth *new;
1145
1146         gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1147         if (gss_auth != NULL)
1148                 goto out;
1149         new = gss_create_new(args, clnt);
1150         if (IS_ERR(new))
1151                 return new;
1152         gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1153         if (gss_auth != new)
1154                 gss_destroy(&new->rpc_auth);
1155 out:
1156         return gss_auth;
1157 }
1158
1159 static struct rpc_auth *
1160 gss_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1161 {
1162         struct gss_auth *gss_auth;
1163         struct rpc_xprt *xprt = rcu_access_pointer(clnt->cl_xprt);
1164
1165         while (clnt != clnt->cl_parent) {
1166                 struct rpc_clnt *parent = clnt->cl_parent;
1167                 /* Find the original parent for this transport */
1168                 if (rcu_access_pointer(parent->cl_xprt) != xprt)
1169                         break;
1170                 clnt = parent;
1171         }
1172
1173         gss_auth = gss_create_hashed(args, clnt);
1174         if (IS_ERR(gss_auth))
1175                 return ERR_CAST(gss_auth);
1176         return &gss_auth->rpc_auth;
1177 }
1178
1179 /*
1180  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
1181  * to the server with the GSS control procedure field set to
1182  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1183  * all RPCSEC_GSS state associated with that context.
1184  */
1185 static int
1186 gss_destroying_context(struct rpc_cred *cred)
1187 {
1188         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1189         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1190         struct rpc_task *task;
1191
1192         if (gss_cred->gc_ctx == NULL ||
1193             test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
1194                 return 0;
1195
1196         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1197         cred->cr_ops = &gss_nullops;
1198
1199         /* Take a reference to ensure the cred will be destroyed either
1200          * by the RPC call or by the put_rpccred() below */
1201         get_rpccred(cred);
1202
1203         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
1204         if (!IS_ERR(task))
1205                 rpc_put_task(task);
1206
1207         put_rpccred(cred);
1208         return 1;
1209 }
1210
1211 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1212  * to create a new cred or context, so they check that things have been
1213  * allocated before freeing them. */
1214 static void
1215 gss_do_free_ctx(struct gss_cl_ctx *ctx)
1216 {
1217         dprintk("RPC:       %s\n", __func__);
1218
1219         gss_delete_sec_context(&ctx->gc_gss_ctx);
1220         kfree(ctx->gc_wire_ctx.data);
1221         kfree(ctx);
1222 }
1223
1224 static void
1225 gss_free_ctx_callback(struct rcu_head *head)
1226 {
1227         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1228         gss_do_free_ctx(ctx);
1229 }
1230
1231 static void
1232 gss_free_ctx(struct gss_cl_ctx *ctx)
1233 {
1234         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1235 }
1236
1237 static void
1238 gss_free_cred(struct gss_cred *gss_cred)
1239 {
1240         dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1241         kfree(gss_cred);
1242 }
1243
1244 static void
1245 gss_free_cred_callback(struct rcu_head *head)
1246 {
1247         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1248         gss_free_cred(gss_cred);
1249 }
1250
1251 static void
1252 gss_destroy_nullcred(struct rpc_cred *cred)
1253 {
1254         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1255         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1256         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
1257
1258         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1259         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1260         if (ctx)
1261                 gss_put_ctx(ctx);
1262         kref_put(&gss_auth->kref, gss_free_callback);
1263 }
1264
1265 static void
1266 gss_destroy_cred(struct rpc_cred *cred)
1267 {
1268
1269         if (gss_destroying_context(cred))
1270                 return;
1271         gss_destroy_nullcred(cred);
1272 }
1273
1274 /*
1275  * Lookup RPCSEC_GSS cred for the current process
1276  */
1277 static struct rpc_cred *
1278 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1279 {
1280         return rpcauth_lookup_credcache(auth, acred, flags);
1281 }
1282
1283 static struct rpc_cred *
1284 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1285 {
1286         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1287         struct gss_cred *cred = NULL;
1288         int err = -ENOMEM;
1289
1290         dprintk("RPC:       %s for uid %d, flavor %d\n",
1291                 __func__, from_kuid(&init_user_ns, acred->uid),
1292                 auth->au_flavor);
1293
1294         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
1295                 goto out_err;
1296
1297         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1298         /*
1299          * Note: in order to force a call to call_refresh(), we deliberately
1300          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1301          */
1302         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1303         cred->gc_service = gss_auth->service;
1304         cred->gc_principal = NULL;
1305         if (acred->machine_cred)
1306                 cred->gc_principal = acred->principal;
1307         kref_get(&gss_auth->kref);
1308         return &cred->gc_base;
1309
1310 out_err:
1311         dprintk("RPC:       %s failed with error %d\n", __func__, err);
1312         return ERR_PTR(err);
1313 }
1314
1315 static int
1316 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1317 {
1318         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1319         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1320         int err;
1321
1322         do {
1323                 err = gss_create_upcall(gss_auth, gss_cred);
1324         } while (err == -EAGAIN);
1325         return err;
1326 }
1327
1328 /*
1329  * Returns -EACCES if GSS context is NULL or will expire within the
1330  * timeout (miliseconds)
1331  */
1332 static int
1333 gss_key_timeout(struct rpc_cred *rc)
1334 {
1335         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1336         unsigned long now = jiffies;
1337         unsigned long expire;
1338
1339         if (gss_cred->gc_ctx == NULL)
1340                 return -EACCES;
1341
1342         expire = gss_cred->gc_ctx->gc_expiry - (gss_key_expire_timeo * HZ);
1343
1344         if (time_after(now, expire))
1345                 return -EACCES;
1346         return 0;
1347 }
1348
1349 static int
1350 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1351 {
1352         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1353         int ret;
1354
1355         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1356                 goto out;
1357         /* Don't match with creds that have expired. */
1358         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
1359                 return 0;
1360         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1361                 return 0;
1362 out:
1363         if (acred->principal != NULL) {
1364                 if (gss_cred->gc_principal == NULL)
1365                         return 0;
1366                 ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1367                 goto check_expire;
1368         }
1369         if (gss_cred->gc_principal != NULL)
1370                 return 0;
1371         ret = uid_eq(rc->cr_uid, acred->uid);
1372
1373 check_expire:
1374         if (ret == 0)
1375                 return ret;
1376
1377         /* Notify acred users of GSS context expiration timeout */
1378         if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags) &&
1379             (gss_key_timeout(rc) != 0)) {
1380                 /* test will now be done from generic cred */
1381                 test_and_clear_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
1382                 /* tell NFS layer that key will expire soon */
1383                 set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
1384         }
1385         return ret;
1386 }
1387
1388 /*
1389 * Marshal credentials.
1390 * Maybe we should keep a cached credential for performance reasons.
1391 */
1392 static __be32 *
1393 gss_marshal(struct rpc_task *task, __be32 *p)
1394 {
1395         struct rpc_rqst *req = task->tk_rqstp;
1396         struct rpc_cred *cred = req->rq_cred;
1397         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1398                                                  gc_base);
1399         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1400         __be32          *cred_len;
1401         u32             maj_stat = 0;
1402         struct xdr_netobj mic;
1403         struct kvec     iov;
1404         struct xdr_buf  verf_buf;
1405
1406         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1407
1408         *p++ = htonl(RPC_AUTH_GSS);
1409         cred_len = p++;
1410
1411         spin_lock(&ctx->gc_seq_lock);
1412         req->rq_seqno = ctx->gc_seq++;
1413         spin_unlock(&ctx->gc_seq_lock);
1414
1415         *p++ = htonl((u32) RPC_GSS_VERSION);
1416         *p++ = htonl((u32) ctx->gc_proc);
1417         *p++ = htonl((u32) req->rq_seqno);
1418         *p++ = htonl((u32) gss_cred->gc_service);
1419         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1420         *cred_len = htonl((p - (cred_len + 1)) << 2);
1421
1422         /* We compute the checksum for the verifier over the xdr-encoded bytes
1423          * starting with the xid and ending at the end of the credential: */
1424         iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
1425                                         req->rq_snd_buf.head[0].iov_base);
1426         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1427         xdr_buf_from_iov(&iov, &verf_buf);
1428
1429         /* set verifier flavor*/
1430         *p++ = htonl(RPC_AUTH_GSS);
1431
1432         mic.data = (u8 *)(p + 1);
1433         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1434         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1435                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1436         } else if (maj_stat != 0) {
1437                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1438                 goto out_put_ctx;
1439         }
1440         p = xdr_encode_opaque(p, NULL, mic.len);
1441         gss_put_ctx(ctx);
1442         return p;
1443 out_put_ctx:
1444         gss_put_ctx(ctx);
1445         return NULL;
1446 }
1447
1448 static int gss_renew_cred(struct rpc_task *task)
1449 {
1450         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1451         struct gss_cred *gss_cred = container_of(oldcred,
1452                                                  struct gss_cred,
1453                                                  gc_base);
1454         struct rpc_auth *auth = oldcred->cr_auth;
1455         struct auth_cred acred = {
1456                 .uid = oldcred->cr_uid,
1457                 .principal = gss_cred->gc_principal,
1458                 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
1459         };
1460         struct rpc_cred *new;
1461
1462         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1463         if (IS_ERR(new))
1464                 return PTR_ERR(new);
1465         task->tk_rqstp->rq_cred = new;
1466         put_rpccred(oldcred);
1467         return 0;
1468 }
1469
1470 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1471 {
1472         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1473                 unsigned long now = jiffies;
1474                 unsigned long begin, expire;
1475                 struct gss_cred *gss_cred;
1476
1477                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1478                 begin = gss_cred->gc_upcall_timestamp;
1479                 expire = begin + gss_expired_cred_retry_delay * HZ;
1480
1481                 if (time_in_range_open(now, begin, expire))
1482                         return 1;
1483         }
1484         return 0;
1485 }
1486
1487 /*
1488 * Refresh credentials. XXX - finish
1489 */
1490 static int
1491 gss_refresh(struct rpc_task *task)
1492 {
1493         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1494         int ret = 0;
1495
1496         if (gss_cred_is_negative_entry(cred))
1497                 return -EKEYEXPIRED;
1498
1499         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1500                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1501                 ret = gss_renew_cred(task);
1502                 if (ret < 0)
1503                         goto out;
1504                 cred = task->tk_rqstp->rq_cred;
1505         }
1506
1507         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1508                 ret = gss_refresh_upcall(task);
1509 out:
1510         return ret;
1511 }
1512
1513 /* Dummy refresh routine: used only when destroying the context */
1514 static int
1515 gss_refresh_null(struct rpc_task *task)
1516 {
1517         return 0;
1518 }
1519
1520 static __be32 *
1521 gss_validate(struct rpc_task *task, __be32 *p)
1522 {
1523         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1524         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1525         __be32          seq;
1526         struct kvec     iov;
1527         struct xdr_buf  verf_buf;
1528         struct xdr_netobj mic;
1529         u32             flav,len;
1530         u32             maj_stat;
1531         __be32          *ret = ERR_PTR(-EIO);
1532
1533         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1534
1535         flav = ntohl(*p++);
1536         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1537                 goto out_bad;
1538         if (flav != RPC_AUTH_GSS)
1539                 goto out_bad;
1540         seq = htonl(task->tk_rqstp->rq_seqno);
1541         iov.iov_base = &seq;
1542         iov.iov_len = sizeof(seq);
1543         xdr_buf_from_iov(&iov, &verf_buf);
1544         mic.data = (u8 *)p;
1545         mic.len = len;
1546
1547         ret = ERR_PTR(-EACCES);
1548         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1549         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1550                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1551         if (maj_stat) {
1552                 dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1553                         task->tk_pid, __func__, maj_stat);
1554                 goto out_bad;
1555         }
1556         /* We leave it to unwrap to calculate au_rslack. For now we just
1557          * calculate the length of the verifier: */
1558         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1559         gss_put_ctx(ctx);
1560         dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1561                         task->tk_pid, __func__);
1562         return p + XDR_QUADLEN(len);
1563 out_bad:
1564         gss_put_ctx(ctx);
1565         dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
1566                 PTR_ERR(ret));
1567         return ret;
1568 }
1569
1570 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1571                                 __be32 *p, void *obj)
1572 {
1573         struct xdr_stream xdr;
1574
1575         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1576         encode(rqstp, &xdr, obj);
1577 }
1578
1579 static inline int
1580 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1581                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1582                    __be32 *p, void *obj)
1583 {
1584         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1585         struct xdr_buf  integ_buf;
1586         __be32          *integ_len = NULL;
1587         struct xdr_netobj mic;
1588         u32             offset;
1589         __be32          *q;
1590         struct kvec     *iov;
1591         u32             maj_stat = 0;
1592         int             status = -EIO;
1593
1594         integ_len = p++;
1595         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1596         *p++ = htonl(rqstp->rq_seqno);
1597
1598         gss_wrap_req_encode(encode, rqstp, p, obj);
1599
1600         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1601                                 offset, snd_buf->len - offset))
1602                 return status;
1603         *integ_len = htonl(integ_buf.len);
1604
1605         /* guess whether we're in the head or the tail: */
1606         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1607                 iov = snd_buf->tail;
1608         else
1609                 iov = snd_buf->head;
1610         p = iov->iov_base + iov->iov_len;
1611         mic.data = (u8 *)(p + 1);
1612
1613         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1614         status = -EIO; /* XXX? */
1615         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1616                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1617         else if (maj_stat)
1618                 return status;
1619         q = xdr_encode_opaque(p, NULL, mic.len);
1620
1621         offset = (u8 *)q - (u8 *)p;
1622         iov->iov_len += offset;
1623         snd_buf->len += offset;
1624         return 0;
1625 }
1626
1627 static void
1628 priv_release_snd_buf(struct rpc_rqst *rqstp)
1629 {
1630         int i;
1631
1632         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1633                 __free_page(rqstp->rq_enc_pages[i]);
1634         kfree(rqstp->rq_enc_pages);
1635 }
1636
1637 static int
1638 alloc_enc_pages(struct rpc_rqst *rqstp)
1639 {
1640         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1641         int first, last, i;
1642
1643         if (snd_buf->page_len == 0) {
1644                 rqstp->rq_enc_pages_num = 0;
1645                 return 0;
1646         }
1647
1648         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1649         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1650         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1651         rqstp->rq_enc_pages
1652                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1653                                 GFP_NOFS);
1654         if (!rqstp->rq_enc_pages)
1655                 goto out;
1656         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1657                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1658                 if (rqstp->rq_enc_pages[i] == NULL)
1659                         goto out_free;
1660         }
1661         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1662         return 0;
1663 out_free:
1664         rqstp->rq_enc_pages_num = i;
1665         priv_release_snd_buf(rqstp);
1666 out:
1667         return -EAGAIN;
1668 }
1669
1670 static inline int
1671 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1672                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1673                   __be32 *p, void *obj)
1674 {
1675         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1676         u32             offset;
1677         u32             maj_stat;
1678         int             status;
1679         __be32          *opaque_len;
1680         struct page     **inpages;
1681         int             first;
1682         int             pad;
1683         struct kvec     *iov;
1684         char            *tmp;
1685
1686         opaque_len = p++;
1687         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1688         *p++ = htonl(rqstp->rq_seqno);
1689
1690         gss_wrap_req_encode(encode, rqstp, p, obj);
1691
1692         status = alloc_enc_pages(rqstp);
1693         if (status)
1694                 return status;
1695         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1696         inpages = snd_buf->pages + first;
1697         snd_buf->pages = rqstp->rq_enc_pages;
1698         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1699         /*
1700          * Give the tail its own page, in case we need extra space in the
1701          * head when wrapping:
1702          *
1703          * call_allocate() allocates twice the slack space required
1704          * by the authentication flavor to rq_callsize.
1705          * For GSS, slack is GSS_CRED_SLACK.
1706          */
1707         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1708                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1709                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1710                 snd_buf->tail[0].iov_base = tmp;
1711         }
1712         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1713         /* slack space should prevent this ever happening: */
1714         BUG_ON(snd_buf->len > snd_buf->buflen);
1715         status = -EIO;
1716         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1717          * done anyway, so it's safe to put the request on the wire: */
1718         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1719                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1720         else if (maj_stat)
1721                 return status;
1722
1723         *opaque_len = htonl(snd_buf->len - offset);
1724         /* guess whether we're in the head or the tail: */
1725         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1726                 iov = snd_buf->tail;
1727         else
1728                 iov = snd_buf->head;
1729         p = iov->iov_base + iov->iov_len;
1730         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1731         memset(p, 0, pad);
1732         iov->iov_len += pad;
1733         snd_buf->len += pad;
1734
1735         return 0;
1736 }
1737
1738 static int
1739 gss_wrap_req(struct rpc_task *task,
1740              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1741 {
1742         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1743         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1744                         gc_base);
1745         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1746         int             status = -EIO;
1747
1748         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1749         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1750                 /* The spec seems a little ambiguous here, but I think that not
1751                  * wrapping context destruction requests makes the most sense.
1752                  */
1753                 gss_wrap_req_encode(encode, rqstp, p, obj);
1754                 status = 0;
1755                 goto out;
1756         }
1757         switch (gss_cred->gc_service) {
1758         case RPC_GSS_SVC_NONE:
1759                 gss_wrap_req_encode(encode, rqstp, p, obj);
1760                 status = 0;
1761                 break;
1762         case RPC_GSS_SVC_INTEGRITY:
1763                 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1764                 break;
1765         case RPC_GSS_SVC_PRIVACY:
1766                 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1767                 break;
1768         }
1769 out:
1770         gss_put_ctx(ctx);
1771         dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1772         return status;
1773 }
1774
1775 static inline int
1776 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1777                 struct rpc_rqst *rqstp, __be32 **p)
1778 {
1779         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1780         struct xdr_buf integ_buf;
1781         struct xdr_netobj mic;
1782         u32 data_offset, mic_offset;
1783         u32 integ_len;
1784         u32 maj_stat;
1785         int status = -EIO;
1786
1787         integ_len = ntohl(*(*p)++);
1788         if (integ_len & 3)
1789                 return status;
1790         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1791         mic_offset = integ_len + data_offset;
1792         if (mic_offset > rcv_buf->len)
1793                 return status;
1794         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1795                 return status;
1796
1797         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1798                                 mic_offset - data_offset))
1799                 return status;
1800
1801         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1802                 return status;
1803
1804         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1805         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1806                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1807         if (maj_stat != GSS_S_COMPLETE)
1808                 return status;
1809         return 0;
1810 }
1811
1812 static inline int
1813 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1814                 struct rpc_rqst *rqstp, __be32 **p)
1815 {
1816         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1817         u32 offset;
1818         u32 opaque_len;
1819         u32 maj_stat;
1820         int status = -EIO;
1821
1822         opaque_len = ntohl(*(*p)++);
1823         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1824         if (offset + opaque_len > rcv_buf->len)
1825                 return status;
1826         /* remove padding: */
1827         rcv_buf->len = offset + opaque_len;
1828
1829         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1830         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1831                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1832         if (maj_stat != GSS_S_COMPLETE)
1833                 return status;
1834         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1835                 return status;
1836
1837         return 0;
1838 }
1839
1840 static int
1841 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1842                       __be32 *p, void *obj)
1843 {
1844         struct xdr_stream xdr;
1845
1846         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1847         return decode(rqstp, &xdr, obj);
1848 }
1849
1850 static int
1851 gss_unwrap_resp(struct rpc_task *task,
1852                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1853 {
1854         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1855         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1856                         gc_base);
1857         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1858         __be32          *savedp = p;
1859         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1860         int             savedlen = head->iov_len;
1861         int             status = -EIO;
1862
1863         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1864                 goto out_decode;
1865         switch (gss_cred->gc_service) {
1866         case RPC_GSS_SVC_NONE:
1867                 break;
1868         case RPC_GSS_SVC_INTEGRITY:
1869                 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1870                 if (status)
1871                         goto out;
1872                 break;
1873         case RPC_GSS_SVC_PRIVACY:
1874                 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1875                 if (status)
1876                         goto out;
1877                 break;
1878         }
1879         /* take into account extra slack for integrity and privacy cases: */
1880         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1881                                                 + (savedlen - head->iov_len);
1882 out_decode:
1883         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
1884 out:
1885         gss_put_ctx(ctx);
1886         dprintk("RPC: %5u %s returning %d\n",
1887                 task->tk_pid, __func__, status);
1888         return status;
1889 }
1890
1891 static const struct rpc_authops authgss_ops = {
1892         .owner          = THIS_MODULE,
1893         .au_flavor      = RPC_AUTH_GSS,
1894         .au_name        = "RPCSEC_GSS",
1895         .create         = gss_create,
1896         .destroy        = gss_destroy,
1897         .lookup_cred    = gss_lookup_cred,
1898         .crcreate       = gss_create_cred,
1899         .list_pseudoflavors = gss_mech_list_pseudoflavors,
1900         .info2flavor    = gss_mech_info2flavor,
1901         .flavor2info    = gss_mech_flavor2info,
1902 };
1903
1904 static const struct rpc_credops gss_credops = {
1905         .cr_name        = "AUTH_GSS",
1906         .crdestroy      = gss_destroy_cred,
1907         .cr_init        = gss_cred_init,
1908         .crbind         = rpcauth_generic_bind_cred,
1909         .crmatch        = gss_match,
1910         .crmarshal      = gss_marshal,
1911         .crrefresh      = gss_refresh,
1912         .crvalidate     = gss_validate,
1913         .crwrap_req     = gss_wrap_req,
1914         .crunwrap_resp  = gss_unwrap_resp,
1915         .crkey_timeout  = gss_key_timeout,
1916 };
1917
1918 static const struct rpc_credops gss_nullops = {
1919         .cr_name        = "AUTH_GSS",
1920         .crdestroy      = gss_destroy_nullcred,
1921         .crbind         = rpcauth_generic_bind_cred,
1922         .crmatch        = gss_match,
1923         .crmarshal      = gss_marshal,
1924         .crrefresh      = gss_refresh_null,
1925         .crvalidate     = gss_validate,
1926         .crwrap_req     = gss_wrap_req,
1927         .crunwrap_resp  = gss_unwrap_resp,
1928 };
1929
1930 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
1931         .upcall         = rpc_pipe_generic_upcall,
1932         .downcall       = gss_pipe_downcall,
1933         .destroy_msg    = gss_pipe_destroy_msg,
1934         .open_pipe      = gss_pipe_open_v0,
1935         .release_pipe   = gss_pipe_release,
1936 };
1937
1938 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
1939         .upcall         = rpc_pipe_generic_upcall,
1940         .downcall       = gss_pipe_downcall,
1941         .destroy_msg    = gss_pipe_destroy_msg,
1942         .open_pipe      = gss_pipe_open_v1,
1943         .release_pipe   = gss_pipe_release,
1944 };
1945
1946 static __net_init int rpcsec_gss_init_net(struct net *net)
1947 {
1948         return gss_svc_init_net(net);
1949 }
1950
1951 static __net_exit void rpcsec_gss_exit_net(struct net *net)
1952 {
1953         gss_svc_shutdown_net(net);
1954 }
1955
1956 static struct pernet_operations rpcsec_gss_net_ops = {
1957         .init = rpcsec_gss_init_net,
1958         .exit = rpcsec_gss_exit_net,
1959 };
1960
1961 /*
1962  * Initialize RPCSEC_GSS module
1963  */
1964 static int __init init_rpcsec_gss(void)
1965 {
1966         int err = 0;
1967
1968         err = rpcauth_register(&authgss_ops);
1969         if (err)
1970                 goto out;
1971         err = gss_svc_init();
1972         if (err)
1973                 goto out_unregister;
1974         err = register_pernet_subsys(&rpcsec_gss_net_ops);
1975         if (err)
1976                 goto out_svc_exit;
1977         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
1978         return 0;
1979 out_svc_exit:
1980         gss_svc_shutdown();
1981 out_unregister:
1982         rpcauth_unregister(&authgss_ops);
1983 out:
1984         return err;
1985 }
1986
1987 static void __exit exit_rpcsec_gss(void)
1988 {
1989         unregister_pernet_subsys(&rpcsec_gss_net_ops);
1990         gss_svc_shutdown();
1991         rpcauth_unregister(&authgss_ops);
1992         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1993 }
1994
1995 MODULE_ALIAS("rpc-auth-6");
1996 MODULE_LICENSE("GPL");
1997 module_param_named(expired_cred_retry_delay,
1998                    gss_expired_cred_retry_delay,
1999                    uint, 0644);
2000 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
2001                 "the RPC engine retries an expired credential");
2002
2003 module_param_named(key_expire_timeo,
2004                    gss_key_expire_timeo,
2005                    uint, 0644);
2006 MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
2007                 "credential keys lifetime where the NFS layer cleans up "
2008                 "prior to key expiration");
2009
2010 module_init(init_rpcsec_gss)
2011 module_exit(exit_rpcsec_gss)