net/sunrpc/auth_gss/auth_gss.c

   1 /*
   2  * linux/net/sunrpc/auth_gss/auth_gss.c
   3  *
   4  * RPCSEC_GSS client authentication.
   5  *
   6  *  Copyright (c) 2000 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Dug Song       <dugsong@monkey.org>
  10  *  Andy Adamson   <andros@umich.edu>
  11  *
  12  *  Redistribution and use in source and binary forms, with or without
  13  *  modification, are permitted provided that the following conditions
  14  *  are met:
  15  *
  16  *  1. Redistributions of source code must retain the above copyright
  17  *     notice, this list of conditions and the following disclaimer.
  18  *  2. Redistributions in binary form must reproduce the above copyright
  19  *     notice, this list of conditions and the following disclaimer in the
  20  *     documentation and/or other materials provided with the distribution.
  21  *  3. Neither the name of the University nor the names of its
  22  *     contributors may be used to endorse or promote products derived
  23  *     from this software without specific prior written permission.
  24  *
  25  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  26  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  27  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  28  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  32  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  33  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  34  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  35  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38
  39 #include <linux/module.h>
  40 #include <linux/init.h>
  41 #include <linux/types.h>
  42 #include <linux/slab.h>
  43 #include <linux/sched.h>
  44 #include <linux/pagemap.h>
  45 #include <linux/sunrpc/clnt.h>
  46 #include <linux/sunrpc/auth.h>
  47 #include <linux/sunrpc/auth_gss.h>
  48 #include <linux/sunrpc/svcauth_gss.h>
  49 #include <linux/sunrpc/gss_err.h>
  50 #include <linux/workqueue.h>
  51 #include <linux/sunrpc/rpc_pipe_fs.h>
  52 #include <linux/sunrpc/gss_api.h>
  53 #include <linux/uaccess.h>
  54 #include <linux/hashtable.h>
  55
  56 #include "../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 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  70 # define RPCDBG_FACILITY        RPCDBG_AUTH
  71 #endif
  72
  73 #define GSS_CRED_SLACK          (RPC_MAX_AUTH_SIZE * 2)
  74 /* length of a krb5 verifier (48), plus data added before arguments when
  75  * using integrity (two 4-byte integers): */
  76 #define GSS_VERF_SLACK          100
  77
  78 static DEFINE_HASHTABLE(gss_auth_hash_table, 4);
  79 static DEFINE_SPINLOCK(gss_auth_hash_lock);
  80
  81 struct gss_pipe {
  82         struct rpc_pipe_dir_object pdo;
  83         struct rpc_pipe *pipe;
  84         struct rpc_clnt *clnt;
  85         const char *name;
  86         struct kref kref;
  87 };
  88
  89 struct gss_auth {
  90         struct kref kref;
  91         struct hlist_node hash;
  92         struct rpc_auth rpc_auth;
  93         struct gss_api_mech *mech;
  94         enum rpc_gss_svc service;
  95         struct rpc_clnt *client;
  96         struct net *net;
  97         /*
  98          * There are two upcall pipes; dentry[1], named "gssd", is used
  99          * for the new text-based upcall; dentry[0] is named after the
 100          * mechanism (for example, "krb5") and exists for
 101          * backwards-compatibility with older gssd's.
 102          */
 103         struct gss_pipe *gss_pipe[2];
 104         const char *target_name;
 105 };
 106
 107 /* pipe_version >= 0 if and only if someone has a pipe open. */
 108 static DEFINE_SPINLOCK(pipe_version_lock);
 109 static struct rpc_wait_queue pipe_version_rpc_waitqueue;
 110 static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
 111 static void gss_put_auth(struct gss_auth *gss_auth);
 112
 113 static void gss_free_ctx(struct gss_cl_ctx *);
 114 static const struct rpc_pipe_ops gss_upcall_ops_v0;
 115 static const struct rpc_pipe_ops gss_upcall_ops_v1;
 116
 117 static inline struct gss_cl_ctx *
 118 gss_get_ctx(struct gss_cl_ctx *ctx)
 119 {
 120         refcount_inc(&ctx->count);
 121         return ctx;
 122 }
 123
 124 static inline void
 125 gss_put_ctx(struct gss_cl_ctx *ctx)
 126 {
 127         if (refcount_dec_and_test(&ctx->count))
 128                 gss_free_ctx(ctx);
 129 }
 130
 131 /* gss_cred_set_ctx:
 132  * called by gss_upcall_callback and gss_create_upcall in order
 133  * to set the gss context. The actual exchange of an old context
 134  * and a new one is protected by the pipe->lock.
 135  */
 136 static void
 137 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 138 {
 139         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 140
 141         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 142                 return;
 143         gss_get_ctx(ctx);
 144         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 145         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 146         smp_mb__before_atomic();
 147         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 148 }
 149
 150 static const void *
 151 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 152 {
 153         const void *q = (const void *)((const char *)p + len);
 154         if (unlikely(q > end || q < p))
 155                 return ERR_PTR(-EFAULT);
 156         memcpy(res, p, len);
 157         return q;
 158 }
 159
 160 static inline const void *
 161 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 162 {
 163         const void *q;
 164         unsigned int len;
 165
 166         p = simple_get_bytes(p, end, &len, sizeof(len));
 167         if (IS_ERR(p))
 168                 return p;
 169         q = (const void *)((const char *)p + len);
 170         if (unlikely(q > end || q < p))
 171                 return ERR_PTR(-EFAULT);
 172         dest->data = kmemdup(p, len, GFP_NOFS);
 173         if (unlikely(dest->data == NULL))
 174                 return ERR_PTR(-ENOMEM);
 175         dest->len = len;
 176         return q;
 177 }
 178
 179 static struct gss_cl_ctx *
 180 gss_cred_get_ctx(struct rpc_cred *cred)
 181 {
 182         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 183         struct gss_cl_ctx *ctx = NULL;
 184
 185         rcu_read_lock();
 186         ctx = rcu_dereference(gss_cred->gc_ctx);
 187         if (ctx)
 188                 gss_get_ctx(ctx);
 189         rcu_read_unlock();
 190         return ctx;
 191 }
 192
 193 static struct gss_cl_ctx *
 194 gss_alloc_context(void)
 195 {
 196         struct gss_cl_ctx *ctx;
 197
 198         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
 199         if (ctx != NULL) {
 200                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 201                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 202                 spin_lock_init(&ctx->gc_seq_lock);
 203                 refcount_set(&ctx->count,1);
 204         }
 205         return ctx;
 206 }
 207
 208 #define GSSD_MIN_TIMEOUT (60 * 60)
 209 static const void *
 210 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 211 {
 212         const void *q;
 213         unsigned int seclen;
 214         unsigned int timeout;
 215         unsigned long now = jiffies;
 216         u32 window_size;
 217         int ret;
 218
 219         /* First unsigned int gives the remaining lifetime in seconds of the
 220          * credential - e.g. the remaining TGT lifetime for Kerberos or
 221          * the -t value passed to GSSD.
 222          */
 223         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 224         if (IS_ERR(p))
 225                 goto err;
 226         if (timeout == 0)
 227                 timeout = GSSD_MIN_TIMEOUT;
 228         ctx->gc_expiry = now + ((unsigned long)timeout * HZ);
 229         /* Sequence number window. Determines the maximum number of
 230          * simultaneous requests
 231          */
 232         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 233         if (IS_ERR(p))
 234                 goto err;
 235         ctx->gc_win = window_size;
 236         /* gssd signals an error by passing ctx->gc_win = 0: */
 237         if (ctx->gc_win == 0) {
 238                 /*
 239                  * in which case, p points to an error code. Anything other
 240                  * than -EKEYEXPIRED gets converted to -EACCES.
 241                  */
 242                 p = simple_get_bytes(p, end, &ret, sizeof(ret));
 243                 if (!IS_ERR(p))
 244                         p = (ret == -EKEYEXPIRED) ? ERR_PTR(-EKEYEXPIRED) :
 245                                                     ERR_PTR(-EACCES);
 246                 goto err;
 247         }
 248         /* copy the opaque wire context */
 249         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 250         if (IS_ERR(p))
 251                 goto err;
 252         /* import the opaque security context */
 253         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 254         if (IS_ERR(p))
 255                 goto err;
 256         q = (const void *)((const char *)p + seclen);
 257         if (unlikely(q > end || q < p)) {
 258                 p = ERR_PTR(-EFAULT);
 259                 goto err;
 260         }
 261         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, NULL, GFP_NOFS);
 262         if (ret < 0) {
 263                 p = ERR_PTR(ret);
 264                 goto err;
 265         }
 266
 267         /* is there any trailing data? */
 268         if (q == end) {
 269                 p = q;
 270                 goto done;
 271         }
 272
 273         /* pull in acceptor name (if there is one) */
 274         p = simple_get_netobj(q, end, &ctx->gc_acceptor);
 275         if (IS_ERR(p))
 276                 goto err;
 277 done:
 278         dprintk("RPC:       %s Success. gc_expiry %lu now %lu timeout %u acceptor %.*s\n",
 279                 __func__, ctx->gc_expiry, now, timeout, ctx->gc_acceptor.len,
 280                 ctx->gc_acceptor.data);
 281         return p;
 282 err:
 283         dprintk("RPC:       %s returns error %ld\n", __func__, -PTR_ERR(p));
 284         return p;
 285 }
 286
 287 #define UPCALL_BUF_LEN 128
 288
 289 struct gss_upcall_msg {
 290         refcount_t count;
 291         kuid_t  uid;
 292         struct rpc_pipe_msg msg;
 293         struct list_head list;
 294         struct gss_auth *auth;
 295         struct rpc_pipe *pipe;
 296         struct rpc_wait_queue rpc_waitqueue;
 297         wait_queue_head_t waitqueue;
 298         struct gss_cl_ctx *ctx;
 299         char databuf[UPCALL_BUF_LEN];
 300 };
 301
 302 static int get_pipe_version(struct net *net)
 303 {
 304         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 305         int ret;
 306
 307         spin_lock(&pipe_version_lock);
 308         if (sn->pipe_version >= 0) {
 309                 atomic_inc(&sn->pipe_users);
 310                 ret = sn->pipe_version;
 311         } else
 312                 ret = -EAGAIN;
 313         spin_unlock(&pipe_version_lock);
 314         return ret;
 315 }
 316
 317 static void put_pipe_version(struct net *net)
 318 {
 319         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 320
 321         if (atomic_dec_and_lock(&sn->pipe_users, &pipe_version_lock)) {
 322                 sn->pipe_version = -1;
 323                 spin_unlock(&pipe_version_lock);
 324         }
 325 }
 326
 327 static void
 328 gss_release_msg(struct gss_upcall_msg *gss_msg)
 329 {
 330         struct net *net = gss_msg->auth->net;
 331         if (!refcount_dec_and_test(&gss_msg->count))
 332                 return;
 333         put_pipe_version(net);
 334         BUG_ON(!list_empty(&gss_msg->list));
 335         if (gss_msg->ctx != NULL)
 336                 gss_put_ctx(gss_msg->ctx);
 337         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 338         gss_put_auth(gss_msg->auth);
 339         kfree(gss_msg);
 340 }
 341
 342 static struct gss_upcall_msg *
 343 __gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid, const struct gss_auth *auth)
 344 {
 345         struct gss_upcall_msg *pos;
 346         list_for_each_entry(pos, &pipe->in_downcall, list) {
 347                 if (!uid_eq(pos->uid, uid))
 348                         continue;
 349                 if (auth && pos->auth->service != auth->service)
 350                         continue;
 351                 refcount_inc(&pos->count);
 352                 dprintk("RPC:       %s found msg %p\n", __func__, pos);
 353                 return pos;
 354         }
 355         dprintk("RPC:       %s found nothing\n", __func__);
 356         return NULL;
 357 }
 358
 359 /* Try to add an upcall to the pipefs queue.
 360  * If an upcall owned by our uid already exists, then we return a reference
 361  * to that upcall instead of adding the new upcall.
 362  */
 363 static inline struct gss_upcall_msg *
 364 gss_add_msg(struct gss_upcall_msg *gss_msg)
 365 {
 366         struct rpc_pipe *pipe = gss_msg->pipe;
 367         struct gss_upcall_msg *old;
 368
 369         spin_lock(&pipe->lock);
 370         old = __gss_find_upcall(pipe, gss_msg->uid, gss_msg->auth);
 371         if (old == NULL) {
 372                 refcount_inc(&gss_msg->count);
 373                 list_add(&gss_msg->list, &pipe->in_downcall);
 374         } else
 375                 gss_msg = old;
 376         spin_unlock(&pipe->lock);
 377         return gss_msg;
 378 }
 379
 380 static void
 381 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 382 {
 383         list_del_init(&gss_msg->list);
 384         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 385         wake_up_all(&gss_msg->waitqueue);
 386         refcount_dec(&gss_msg->count);
 387 }
 388
 389 static void
 390 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 391 {
 392         struct rpc_pipe *pipe = gss_msg->pipe;
 393
 394         if (list_empty(&gss_msg->list))
 395                 return;
 396         spin_lock(&pipe->lock);
 397         if (!list_empty(&gss_msg->list))
 398                 __gss_unhash_msg(gss_msg);
 399         spin_unlock(&pipe->lock);
 400 }
 401
 402 static void
 403 gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
 404 {
 405         switch (gss_msg->msg.errno) {
 406         case 0:
 407                 if (gss_msg->ctx == NULL)
 408                         break;
 409                 clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 410                 gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
 411                 break;
 412         case -EKEYEXPIRED:
 413                 set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 414         }
 415         gss_cred->gc_upcall_timestamp = jiffies;
 416         gss_cred->gc_upcall = NULL;
 417         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 418 }
 419
 420 static void
 421 gss_upcall_callback(struct rpc_task *task)
 422 {
 423         struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
 424                         struct gss_cred, gc_base);
 425         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 426         struct rpc_pipe *pipe = gss_msg->pipe;
 427
 428         spin_lock(&pipe->lock);
 429         gss_handle_downcall_result(gss_cred, gss_msg);
 430         spin_unlock(&pipe->lock);
 431         task->tk_status = gss_msg->msg.errno;
 432         gss_release_msg(gss_msg);
 433 }
 434
 435 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
 436 {
 437         uid_t uid = from_kuid(&init_user_ns, gss_msg->uid);
 438         memcpy(gss_msg->databuf, &uid, sizeof(uid));
 439         gss_msg->msg.data = gss_msg->databuf;
 440         gss_msg->msg.len = sizeof(uid);
 441
 442         BUILD_BUG_ON(sizeof(uid) > sizeof(gss_msg->databuf));
 443 }
 444
 445 static int gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
 446                                 const char *service_name,
 447                                 const char *target_name)
 448 {
 449         struct gss_api_mech *mech = gss_msg->auth->mech;
 450         char *p = gss_msg->databuf;
 451         size_t buflen = sizeof(gss_msg->databuf);
 452         int len;
 453
 454         len = scnprintf(p, buflen, "mech=%s uid=%d ", mech->gm_name,
 455                         from_kuid(&init_user_ns, gss_msg->uid));
 456         buflen -= len;
 457         p += len;
 458         gss_msg->msg.len = len;
 459         if (target_name) {
 460                 len = scnprintf(p, buflen, "target=%s ", target_name);
 461                 buflen -= len;
 462                 p += len;
 463                 gss_msg->msg.len += len;
 464         }
 465         if (service_name != NULL) {
 466                 len = scnprintf(p, buflen, "service=%s ", service_name);
 467                 buflen -= len;
 468                 p += len;
 469                 gss_msg->msg.len += len;
 470         }
 471         if (mech->gm_upcall_enctypes) {
 472                 len = scnprintf(p, buflen, "enctypes=%s ",
 473                                 mech->gm_upcall_enctypes);
 474                 buflen -= len;
 475                 p += len;
 476                 gss_msg->msg.len += len;
 477         }
 478         len = scnprintf(p, buflen, "\n");
 479         if (len == 0)
 480                 goto out_overflow;
 481         gss_msg->msg.len += len;
 482
 483         gss_msg->msg.data = gss_msg->databuf;
 484         return 0;
 485 out_overflow:
 486         WARN_ON_ONCE(1);
 487         return -ENOMEM;
 488 }
 489
 490 static struct gss_upcall_msg *
 491 gss_alloc_msg(struct gss_auth *gss_auth,
 492                 kuid_t uid, const char *service_name)
 493 {
 494         struct gss_upcall_msg *gss_msg;
 495         int vers;
 496         int err = -ENOMEM;
 497
 498         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 499         if (gss_msg == NULL)
 500                 goto err;
 501         vers = get_pipe_version(gss_auth->net);
 502         err = vers;
 503         if (err < 0)
 504                 goto err_free_msg;
 505         gss_msg->pipe = gss_auth->gss_pipe[vers]->pipe;
 506         INIT_LIST_HEAD(&gss_msg->list);
 507         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 508         init_waitqueue_head(&gss_msg->waitqueue);
 509         refcount_set(&gss_msg->count, 1);
 510         gss_msg->uid = uid;
 511         gss_msg->auth = gss_auth;
 512         switch (vers) {
 513         case 0:
 514                 gss_encode_v0_msg(gss_msg);
 515                 break;
 516         default:
 517                 err = gss_encode_v1_msg(gss_msg, service_name, gss_auth->target_name);
 518                 if (err)
 519                         goto err_put_pipe_version;
 520         }
 521         kref_get(&gss_auth->kref);
 522         return gss_msg;
 523 err_put_pipe_version:
 524         put_pipe_version(gss_auth->net);
 525 err_free_msg:
 526         kfree(gss_msg);
 527 err:
 528         return ERR_PTR(err);
 529 }
 530
 531 static struct gss_upcall_msg *
 532 gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred)
 533 {
 534         struct gss_cred *gss_cred = container_of(cred,
 535                         struct gss_cred, gc_base);
 536         struct gss_upcall_msg *gss_new, *gss_msg;
 537         kuid_t uid = cred->cr_uid;
 538
 539         gss_new = gss_alloc_msg(gss_auth, uid, gss_cred->gc_principal);
 540         if (IS_ERR(gss_new))
 541                 return gss_new;
 542         gss_msg = gss_add_msg(gss_new);
 543         if (gss_msg == gss_new) {
 544                 int res;
 545                 refcount_inc(&gss_msg->count);
 546                 res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
 547                 if (res) {
 548                         gss_unhash_msg(gss_new);
 549                         refcount_dec(&gss_msg->count);
 550                         gss_release_msg(gss_new);
 551                         gss_msg = ERR_PTR(res);
 552                 }
 553         } else
 554                 gss_release_msg(gss_new);
 555         return gss_msg;
 556 }
 557
 558 static void warn_gssd(void)
 559 {
 560         dprintk("AUTH_GSS upcall failed. Please check user daemon is running.\n");
 561 }
 562
 563 static inline int
 564 gss_refresh_upcall(struct rpc_task *task)
 565 {
 566         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 567         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 568                         struct gss_auth, rpc_auth);
 569         struct gss_cred *gss_cred = container_of(cred,
 570                         struct gss_cred, gc_base);
 571         struct gss_upcall_msg *gss_msg;
 572         struct rpc_pipe *pipe;
 573         int err = 0;
 574
 575         dprintk("RPC: %5u %s for uid %u\n",
 576                 task->tk_pid, __func__, from_kuid(&init_user_ns, cred->cr_uid));
 577         gss_msg = gss_setup_upcall(gss_auth, cred);
 578         if (PTR_ERR(gss_msg) == -EAGAIN) {
 579                 /* XXX: warning on the first, under the assumption we
 580                  * shouldn't normally hit this case on a refresh. */
 581                 warn_gssd();
 582                 task->tk_timeout = 15*HZ;
 583                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
 584                 return -EAGAIN;
 585         }
 586         if (IS_ERR(gss_msg)) {
 587                 err = PTR_ERR(gss_msg);
 588                 goto out;
 589         }
 590         pipe = gss_msg->pipe;
 591         spin_lock(&pipe->lock);
 592         if (gss_cred->gc_upcall != NULL)
 593                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 594         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 595                 task->tk_timeout = 0;
 596                 gss_cred->gc_upcall = gss_msg;
 597                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 598                 refcount_inc(&gss_msg->count);
 599                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 600         } else {
 601                 gss_handle_downcall_result(gss_cred, gss_msg);
 602                 err = gss_msg->msg.errno;
 603         }
 604         spin_unlock(&pipe->lock);
 605         gss_release_msg(gss_msg);
 606 out:
 607         dprintk("RPC: %5u %s for uid %u result %d\n",
 608                 task->tk_pid, __func__,
 609                 from_kuid(&init_user_ns, cred->cr_uid), err);
 610         return err;
 611 }
 612
 613 static inline int
 614 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 615 {
 616         struct net *net = gss_auth->net;
 617         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 618         struct rpc_pipe *pipe;
 619         struct rpc_cred *cred = &gss_cred->gc_base;
 620         struct gss_upcall_msg *gss_msg;
 621         DEFINE_WAIT(wait);
 622         int err;
 623
 624         dprintk("RPC:       %s for uid %u\n",
 625                 __func__, from_kuid(&init_user_ns, cred->cr_uid));
 626 retry:
 627         err = 0;
 628         /* if gssd is down, just skip upcalling altogether */
 629         if (!gssd_running(net)) {
 630                 warn_gssd();
 631                 return -EACCES;
 632         }
 633         gss_msg = gss_setup_upcall(gss_auth, cred);
 634         if (PTR_ERR(gss_msg) == -EAGAIN) {
 635                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
 636                                 sn->pipe_version >= 0, 15 * HZ);
 637                 if (sn->pipe_version < 0) {
 638                         warn_gssd();
 639                         err = -EACCES;
 640                 }
 641                 if (err < 0)
 642                         goto out;
 643                 goto retry;
 644         }
 645         if (IS_ERR(gss_msg)) {
 646                 err = PTR_ERR(gss_msg);
 647                 goto out;
 648         }
 649         pipe = gss_msg->pipe;
 650         for (;;) {
 651                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
 652                 spin_lock(&pipe->lock);
 653                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 654                         break;
 655                 }
 656                 spin_unlock(&pipe->lock);
 657                 if (fatal_signal_pending(current)) {
 658                         err = -ERESTARTSYS;
 659                         goto out_intr;
 660                 }
 661                 schedule();
 662         }
 663         if (gss_msg->ctx)
 664                 gss_cred_set_ctx(cred, gss_msg->ctx);
 665         else
 666                 err = gss_msg->msg.errno;
 667         spin_unlock(&pipe->lock);
 668 out_intr:
 669         finish_wait(&gss_msg->waitqueue, &wait);
 670         gss_release_msg(gss_msg);
 671 out:
 672         dprintk("RPC:       %s for uid %u result %d\n",
 673                 __func__, from_kuid(&init_user_ns, cred->cr_uid), err);
 674         return err;
 675 }
 676
 677 #define MSG_BUF_MAXSIZE 1024
 678
 679 static ssize_t
 680 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 681 {
 682         const void *p, *end;
 683         void *buf;
 684         struct gss_upcall_msg *gss_msg;
 685         struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
 686         struct gss_cl_ctx *ctx;
 687         uid_t id;
 688         kuid_t uid;
 689         ssize_t err = -EFBIG;
 690
 691         if (mlen > MSG_BUF_MAXSIZE)
 692                 goto out;
 693         err = -ENOMEM;
 694         buf = kmalloc(mlen, GFP_NOFS);
 695         if (!buf)
 696                 goto out;
 697
 698         err = -EFAULT;
 699         if (copy_from_user(buf, src, mlen))
 700                 goto err;
 701
 702         end = (const void *)((char *)buf + mlen);
 703         p = simple_get_bytes(buf, end, &id, sizeof(id));
 704         if (IS_ERR(p)) {
 705                 err = PTR_ERR(p);
 706                 goto err;
 707         }
 708
 709         uid = make_kuid(&init_user_ns, id);
 710         if (!uid_valid(uid)) {
 711                 err = -EINVAL;
 712                 goto err;
 713         }
 714
 715         err = -ENOMEM;
 716         ctx = gss_alloc_context();
 717         if (ctx == NULL)
 718                 goto err;
 719
 720         err = -ENOENT;
 721         /* Find a matching upcall */
 722         spin_lock(&pipe->lock);
 723         gss_msg = __gss_find_upcall(pipe, uid, NULL);
 724         if (gss_msg == NULL) {
 725                 spin_unlock(&pipe->lock);
 726                 goto err_put_ctx;
 727         }
 728         list_del_init(&gss_msg->list);
 729         spin_unlock(&pipe->lock);
 730
 731         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 732         if (IS_ERR(p)) {
 733                 err = PTR_ERR(p);
 734                 switch (err) {
 735                 case -EACCES:
 736                 case -EKEYEXPIRED:
 737                         gss_msg->msg.errno = err;
 738                         err = mlen;
 739                         break;
 740                 case -EFAULT:
 741                 case -ENOMEM:
 742                 case -EINVAL:
 743                 case -ENOSYS:
 744                         gss_msg->msg.errno = -EAGAIN;
 745                         break;
 746                 default:
 747                         printk(KERN_CRIT "%s: bad return from "
 748                                 "gss_fill_context: %zd\n", __func__, err);
 749                         gss_msg->msg.errno = -EIO;
 750                 }
 751                 goto err_release_msg;
 752         }
 753         gss_msg->ctx = gss_get_ctx(ctx);
 754         err = mlen;
 755
 756 err_release_msg:
 757         spin_lock(&pipe->lock);
 758         __gss_unhash_msg(gss_msg);
 759         spin_unlock(&pipe->lock);
 760         gss_release_msg(gss_msg);
 761 err_put_ctx:
 762         gss_put_ctx(ctx);
 763 err:
 764         kfree(buf);
 765 out:
 766         dprintk("RPC:       %s returning %zd\n", __func__, err);
 767         return err;
 768 }
 769
 770 static int gss_pipe_open(struct inode *inode, int new_version)
 771 {
 772         struct net *net = inode->i_sb->s_fs_info;
 773         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 774         int ret = 0;
 775
 776         spin_lock(&pipe_version_lock);
 777         if (sn->pipe_version < 0) {
 778                 /* First open of any gss pipe determines the version: */
 779                 sn->pipe_version = new_version;
 780                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 781                 wake_up(&pipe_version_waitqueue);
 782         } else if (sn->pipe_version != new_version) {
 783                 /* Trying to open a pipe of a different version */
 784                 ret = -EBUSY;
 785                 goto out;
 786         }
 787         atomic_inc(&sn->pipe_users);
 788 out:
 789         spin_unlock(&pipe_version_lock);
 790         return ret;
 791
 792 }
 793
 794 static int gss_pipe_open_v0(struct inode *inode)
 795 {
 796         return gss_pipe_open(inode, 0);
 797 }
 798
 799 static int gss_pipe_open_v1(struct inode *inode)
 800 {
 801         return gss_pipe_open(inode, 1);
 802 }
 803
 804 static void
 805 gss_pipe_release(struct inode *inode)
 806 {
 807         struct net *net = inode->i_sb->s_fs_info;
 808         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 809         struct gss_upcall_msg *gss_msg;
 810
 811 restart:
 812         spin_lock(&pipe->lock);
 813         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
 814
 815                 if (!list_empty(&gss_msg->msg.list))
 816                         continue;
 817                 gss_msg->msg.errno = -EPIPE;
 818                 refcount_inc(&gss_msg->count);
 819                 __gss_unhash_msg(gss_msg);
 820                 spin_unlock(&pipe->lock);
 821                 gss_release_msg(gss_msg);
 822                 goto restart;
 823         }
 824         spin_unlock(&pipe->lock);
 825
 826         put_pipe_version(net);
 827 }
 828
 829 static void
 830 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 831 {
 832         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 833
 834         if (msg->errno < 0) {
 835                 dprintk("RPC:       %s releasing msg %p\n",
 836                         __func__, gss_msg);
 837                 refcount_inc(&gss_msg->count);
 838                 gss_unhash_msg(gss_msg);
 839                 if (msg->errno == -ETIMEDOUT)
 840                         warn_gssd();
 841                 gss_release_msg(gss_msg);
 842         }
 843         gss_release_msg(gss_msg);
 844 }
 845
 846 static void gss_pipe_dentry_destroy(struct dentry *dir,
 847                 struct rpc_pipe_dir_object *pdo)
 848 {
 849         struct gss_pipe *gss_pipe = pdo->pdo_data;
 850         struct rpc_pipe *pipe = gss_pipe->pipe;
 851
 852         if (pipe->dentry != NULL) {
 853                 rpc_unlink(pipe->dentry);
 854                 pipe->dentry = NULL;
 855         }
 856 }
 857
 858 static int gss_pipe_dentry_create(struct dentry *dir,
 859                 struct rpc_pipe_dir_object *pdo)
 860 {
 861         struct gss_pipe *p = pdo->pdo_data;
 862         struct dentry *dentry;
 863
 864         dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
 865         if (IS_ERR(dentry))
 866                 return PTR_ERR(dentry);
 867         p->pipe->dentry = dentry;
 868         return 0;
 869 }
 870
 871 static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
 872         .create = gss_pipe_dentry_create,
 873         .destroy = gss_pipe_dentry_destroy,
 874 };
 875
 876 static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
 877                 const char *name,
 878                 const struct rpc_pipe_ops *upcall_ops)
 879 {
 880         struct gss_pipe *p;
 881         int err = -ENOMEM;
 882
 883         p = kmalloc(sizeof(*p), GFP_KERNEL);
 884         if (p == NULL)
 885                 goto err;
 886         p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 887         if (IS_ERR(p->pipe)) {
 888                 err = PTR_ERR(p->pipe);
 889                 goto err_free_gss_pipe;
 890         }
 891         p->name = name;
 892         p->clnt = clnt;
 893         kref_init(&p->kref);
 894         rpc_init_pipe_dir_object(&p->pdo,
 895                         &gss_pipe_dir_object_ops,
 896                         p);
 897         return p;
 898 err_free_gss_pipe:
 899         kfree(p);
 900 err:
 901         return ERR_PTR(err);
 902 }
 903
 904 struct gss_alloc_pdo {
 905         struct rpc_clnt *clnt;
 906         const char *name;
 907         const struct rpc_pipe_ops *upcall_ops;
 908 };
 909
 910 static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
 911 {
 912         struct gss_pipe *gss_pipe;
 913         struct gss_alloc_pdo *args = data;
 914
 915         if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
 916                 return 0;
 917         gss_pipe = container_of(pdo, struct gss_pipe, pdo);
 918         if (strcmp(gss_pipe->name, args->name) != 0)
 919                 return 0;
 920         if (!kref_get_unless_zero(&gss_pipe->kref))
 921                 return 0;
 922         return 1;
 923 }
 924
 925 static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
 926 {
 927         struct gss_pipe *gss_pipe;
 928         struct gss_alloc_pdo *args = data;
 929
 930         gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
 931         if (!IS_ERR(gss_pipe))
 932                 return &gss_pipe->pdo;
 933         return NULL;
 934 }
 935
 936 static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
 937                 const char *name,
 938                 const struct rpc_pipe_ops *upcall_ops)
 939 {
 940         struct net *net = rpc_net_ns(clnt);
 941         struct rpc_pipe_dir_object *pdo;
 942         struct gss_alloc_pdo args = {
 943                 .clnt = clnt,
 944                 .name = name,
 945                 .upcall_ops = upcall_ops,
 946         };
 947
 948         pdo = rpc_find_or_alloc_pipe_dir_object(net,
 949                         &clnt->cl_pipedir_objects,
 950                         gss_pipe_match_pdo,
 951                         gss_pipe_alloc_pdo,
 952                         &args);
 953         if (pdo != NULL)
 954                 return container_of(pdo, struct gss_pipe, pdo);
 955         return ERR_PTR(-ENOMEM);
 956 }
 957
 958 static void __gss_pipe_free(struct gss_pipe *p)
 959 {
 960         struct rpc_clnt *clnt = p->clnt;
 961         struct net *net = rpc_net_ns(clnt);
 962
 963         rpc_remove_pipe_dir_object(net,
 964                         &clnt->cl_pipedir_objects,
 965                         &p->pdo);
 966         rpc_destroy_pipe_data(p->pipe);
 967         kfree(p);
 968 }
 969
 970 static void __gss_pipe_release(struct kref *kref)
 971 {
 972         struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
 973
 974         __gss_pipe_free(p);
 975 }
 976
 977 static void gss_pipe_free(struct gss_pipe *p)
 978 {
 979         if (p != NULL)
 980                 kref_put(&p->kref, __gss_pipe_release);
 981 }
 982
 983 /*
 984  * NOTE: we have the opportunity to use different
 985  * parameters based on the input flavor (which must be a pseudoflavor)
 986  */
 987 static struct gss_auth *
 988 gss_create_new(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
 989 {
 990         rpc_authflavor_t flavor = args->pseudoflavor;
 991         struct gss_auth *gss_auth;
 992         struct gss_pipe *gss_pipe;
 993         struct rpc_auth * auth;
 994         int err = -ENOMEM; /* XXX? */
 995
 996         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 997
 998         if (!try_module_get(THIS_MODULE))
 999                 return ERR_PTR(err);
1000         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
1001                 goto out_dec;
1002         INIT_HLIST_NODE(&gss_auth->hash);
1003         gss_auth->target_name = NULL;
1004         if (args->target_name) {
1005                 gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
1006                 if (gss_auth->target_name == NULL)
1007                         goto err_free;
1008         }
1009         gss_auth->client = clnt;
1010         gss_auth->net = get_net(rpc_net_ns(clnt));
1011         err = -EINVAL;
1012         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
1013         if (!gss_auth->mech) {
1014                 dprintk("RPC:       Pseudoflavor %d not found!\n", flavor);
1015                 goto err_put_net;
1016         }
1017         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
1018         if (gss_auth->service == 0)
1019                 goto err_put_mech;
1020         if (!gssd_running(gss_auth->net))
1021                 goto err_put_mech;
1022         auth = &gss_auth->rpc_auth;
1023         auth->au_cslack = GSS_CRED_SLACK >> 2;
1024         auth->au_rslack = GSS_VERF_SLACK >> 2;
1025         auth->au_flags = 0;
1026         auth->au_ops = &authgss_ops;
1027         auth->au_flavor = flavor;
1028         if (gss_pseudoflavor_to_datatouch(gss_auth->mech, flavor))
1029                 auth->au_flags |= RPCAUTH_AUTH_DATATOUCH;
1030         atomic_set(&auth->au_count, 1);
1031         kref_init(&gss_auth->kref);
1032
1033         err = rpcauth_init_credcache(auth);
1034         if (err)
1035                 goto err_put_mech;
1036         /*
1037          * Note: if we created the old pipe first, then someone who
1038          * examined the directory at the right moment might conclude
1039          * that we supported only the old pipe.  So we instead create
1040          * the new pipe first.
1041          */
1042         gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
1043         if (IS_ERR(gss_pipe)) {
1044                 err = PTR_ERR(gss_pipe);
1045                 goto err_destroy_credcache;
1046         }
1047         gss_auth->gss_pipe[1] = gss_pipe;
1048
1049         gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
1050                         &gss_upcall_ops_v0);
1051         if (IS_ERR(gss_pipe)) {
1052                 err = PTR_ERR(gss_pipe);
1053                 goto err_destroy_pipe_1;
1054         }
1055         gss_auth->gss_pipe[0] = gss_pipe;
1056
1057         return gss_auth;
1058 err_destroy_pipe_1:
1059         gss_pipe_free(gss_auth->gss_pipe[1]);
1060 err_destroy_credcache:
1061         rpcauth_destroy_credcache(auth);
1062 err_put_mech:
1063         gss_mech_put(gss_auth->mech);
1064 err_put_net:
1065         put_net(gss_auth->net);
1066 err_free:
1067         kfree(gss_auth->target_name);
1068         kfree(gss_auth);
1069 out_dec:
1070         module_put(THIS_MODULE);
1071         return ERR_PTR(err);
1072 }
1073
1074 static void
1075 gss_free(struct gss_auth *gss_auth)
1076 {
1077         gss_pipe_free(gss_auth->gss_pipe[0]);
1078         gss_pipe_free(gss_auth->gss_pipe[1]);
1079         gss_mech_put(gss_auth->mech);
1080         put_net(gss_auth->net);
1081         kfree(gss_auth->target_name);
1082
1083         kfree(gss_auth);
1084         module_put(THIS_MODULE);
1085 }
1086
1087 static void
1088 gss_free_callback(struct kref *kref)
1089 {
1090         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1091
1092         gss_free(gss_auth);
1093 }
1094
1095 static void
1096 gss_put_auth(struct gss_auth *gss_auth)
1097 {
1098         kref_put(&gss_auth->kref, gss_free_callback);
1099 }
1100
1101 static void
1102 gss_destroy(struct rpc_auth *auth)
1103 {
1104         struct gss_auth *gss_auth = container_of(auth,
1105                         struct gss_auth, rpc_auth);
1106
1107         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
1108                         auth, auth->au_flavor);
1109
1110         if (hash_hashed(&gss_auth->hash)) {
1111                 spin_lock(&gss_auth_hash_lock);
1112                 hash_del(&gss_auth->hash);
1113                 spin_unlock(&gss_auth_hash_lock);
1114         }
1115
1116         gss_pipe_free(gss_auth->gss_pipe[0]);
1117         gss_auth->gss_pipe[0] = NULL;
1118         gss_pipe_free(gss_auth->gss_pipe[1]);
1119         gss_auth->gss_pipe[1] = NULL;
1120         rpcauth_destroy_credcache(auth);
1121
1122         gss_put_auth(gss_auth);
1123 }
1124
1125 /*
1126  * Auths may be shared between rpc clients that were cloned from a
1127  * common client with the same xprt, if they also share the flavor and
1128  * target_name.
1129  *
1130  * The auth is looked up from the oldest parent sharing the same
1131  * cl_xprt, and the auth itself references only that common parent
1132  * (which is guaranteed to last as long as any of its descendants).
1133  */
1134 static struct gss_auth *
1135 gss_auth_find_or_add_hashed(struct rpc_auth_create_args *args,
1136                 struct rpc_clnt *clnt,
1137                 struct gss_auth *new)
1138 {
1139         struct gss_auth *gss_auth;
1140         unsigned long hashval = (unsigned long)clnt;
1141
1142         spin_lock(&gss_auth_hash_lock);
1143         hash_for_each_possible(gss_auth_hash_table,
1144                         gss_auth,
1145                         hash,
1146                         hashval) {
1147                 if (gss_auth->client != clnt)
1148                         continue;
1149                 if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1150                         continue;
1151                 if (gss_auth->target_name != args->target_name) {
1152                         if (gss_auth->target_name == NULL)
1153                                 continue;
1154                         if (args->target_name == NULL)
1155                                 continue;
1156                         if (strcmp(gss_auth->target_name, args->target_name))
1157                                 continue;
1158                 }
1159                 if (!atomic_inc_not_zero(&gss_auth->rpc_auth.au_count))
1160                         continue;
1161                 goto out;
1162         }
1163         if (new)
1164                 hash_add(gss_auth_hash_table, &new->hash, hashval);
1165         gss_auth = new;
1166 out:
1167         spin_unlock(&gss_auth_hash_lock);
1168         return gss_auth;
1169 }
1170
1171 static struct gss_auth *
1172 gss_create_hashed(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1173 {
1174         struct gss_auth *gss_auth;
1175         struct gss_auth *new;
1176
1177         gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1178         if (gss_auth != NULL)
1179                 goto out;
1180         new = gss_create_new(args, clnt);
1181         if (IS_ERR(new))
1182                 return new;
1183         gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1184         if (gss_auth != new)
1185                 gss_destroy(&new->rpc_auth);
1186 out:
1187         return gss_auth;
1188 }
1189
1190 static struct rpc_auth *
1191 gss_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1192 {
1193         struct gss_auth *gss_auth;
1194         struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
1195
1196         while (clnt != clnt->cl_parent) {
1197                 struct rpc_clnt *parent = clnt->cl_parent;
1198                 /* Find the original parent for this transport */
1199                 if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
1200                         break;
1201                 clnt = parent;
1202         }
1203
1204         gss_auth = gss_create_hashed(args, clnt);
1205         if (IS_ERR(gss_auth))
1206                 return ERR_CAST(gss_auth);
1207         return &gss_auth->rpc_auth;
1208 }
1209
1210 /*
1211  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
1212  * to the server with the GSS control procedure field set to
1213  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1214  * all RPCSEC_GSS state associated with that context.
1215  */
1216 static int
1217 gss_destroying_context(struct rpc_cred *cred)
1218 {
1219         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1220         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1221         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1222         struct rpc_task *task;
1223
1224         if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
1225                 return 0;
1226
1227         ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1228         cred->cr_ops = &gss_nullops;
1229
1230         /* Take a reference to ensure the cred will be destroyed either
1231          * by the RPC call or by the put_rpccred() below */
1232         get_rpccred(cred);
1233
1234         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
1235         if (!IS_ERR(task))
1236                 rpc_put_task(task);
1237
1238         put_rpccred(cred);
1239         return 1;
1240 }
1241
1242 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1243  * to create a new cred or context, so they check that things have been
1244  * allocated before freeing them. */
1245 static void
1246 gss_do_free_ctx(struct gss_cl_ctx *ctx)
1247 {
1248         dprintk("RPC:       %s\n", __func__);
1249
1250         gss_delete_sec_context(&ctx->gc_gss_ctx);
1251         kfree(ctx->gc_wire_ctx.data);
1252         kfree(ctx->gc_acceptor.data);
1253         kfree(ctx);
1254 }
1255
1256 static void
1257 gss_free_ctx_callback(struct rcu_head *head)
1258 {
1259         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1260         gss_do_free_ctx(ctx);
1261 }
1262
1263 static void
1264 gss_free_ctx(struct gss_cl_ctx *ctx)
1265 {
1266         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1267 }
1268
1269 static void
1270 gss_free_cred(struct gss_cred *gss_cred)
1271 {
1272         dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1273         kfree(gss_cred);
1274 }
1275
1276 static void
1277 gss_free_cred_callback(struct rcu_head *head)
1278 {
1279         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1280         gss_free_cred(gss_cred);
1281 }
1282
1283 static void
1284 gss_destroy_nullcred(struct rpc_cred *cred)
1285 {
1286         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1287         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1288         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1289
1290         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1291         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1292         if (ctx)
1293                 gss_put_ctx(ctx);
1294         gss_put_auth(gss_auth);
1295 }
1296
1297 static void
1298 gss_destroy_cred(struct rpc_cred *cred)
1299 {
1300
1301         if (gss_destroying_context(cred))
1302                 return;
1303         gss_destroy_nullcred(cred);
1304 }
1305
1306 static int
1307 gss_hash_cred(struct auth_cred *acred, unsigned int hashbits)
1308 {
1309         return hash_64(from_kuid(&init_user_ns, acred->uid), hashbits);
1310 }
1311
1312 /*
1313  * Lookup RPCSEC_GSS cred for the current process
1314  */
1315 static struct rpc_cred *
1316 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1317 {
1318         return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS);
1319 }
1320
1321 static struct rpc_cred *
1322 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp)
1323 {
1324         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1325         struct gss_cred *cred = NULL;
1326         int err = -ENOMEM;
1327
1328         dprintk("RPC:       %s for uid %d, flavor %d\n",
1329                 __func__, from_kuid(&init_user_ns, acred->uid),
1330                 auth->au_flavor);
1331
1332         if (!(cred = kzalloc(sizeof(*cred), gfp)))
1333                 goto out_err;
1334
1335         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1336         /*
1337          * Note: in order to force a call to call_refresh(), we deliberately
1338          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1339          */
1340         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1341         cred->gc_service = gss_auth->service;
1342         cred->gc_principal = NULL;
1343         if (acred->machine_cred)
1344                 cred->gc_principal = acred->principal;
1345         kref_get(&gss_auth->kref);
1346         return &cred->gc_base;
1347
1348 out_err:
1349         dprintk("RPC:       %s failed with error %d\n", __func__, err);
1350         return ERR_PTR(err);
1351 }
1352
1353 static int
1354 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1355 {
1356         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1357         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1358         int err;
1359
1360         do {
1361                 err = gss_create_upcall(gss_auth, gss_cred);
1362         } while (err == -EAGAIN);
1363         return err;
1364 }
1365
1366 static char *
1367 gss_stringify_acceptor(struct rpc_cred *cred)
1368 {
1369         char *string = NULL;
1370         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1371         struct gss_cl_ctx *ctx;
1372         unsigned int len;
1373         struct xdr_netobj *acceptor;
1374
1375         rcu_read_lock();
1376         ctx = rcu_dereference(gss_cred->gc_ctx);
1377         if (!ctx)
1378                 goto out;
1379
1380         len = ctx->gc_acceptor.len;
1381         rcu_read_unlock();
1382
1383         /* no point if there's no string */
1384         if (!len)
1385                 return NULL;
1386 realloc:
1387         string = kmalloc(len + 1, GFP_KERNEL);
1388         if (!string)
1389                 return NULL;
1390
1391         rcu_read_lock();
1392         ctx = rcu_dereference(gss_cred->gc_ctx);
1393
1394         /* did the ctx disappear or was it replaced by one with no acceptor? */
1395         if (!ctx || !ctx->gc_acceptor.len) {
1396                 kfree(string);
1397                 string = NULL;
1398                 goto out;
1399         }
1400
1401         acceptor = &ctx->gc_acceptor;
1402
1403         /*
1404          * Did we find a new acceptor that's longer than the original? Allocate
1405          * a longer buffer and try again.
1406          */
1407         if (len < acceptor->len) {
1408                 len = acceptor->len;
1409                 rcu_read_unlock();
1410                 kfree(string);
1411                 goto realloc;
1412         }
1413
1414         memcpy(string, acceptor->data, acceptor->len);
1415         string[acceptor->len] = '\0';
1416 out:
1417         rcu_read_unlock();
1418         return string;
1419 }
1420
1421 /*
1422  * Returns -EACCES if GSS context is NULL or will expire within the
1423  * timeout (miliseconds)
1424  */
1425 static int
1426 gss_key_timeout(struct rpc_cred *rc)
1427 {
1428         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1429         struct gss_cl_ctx *ctx;
1430         unsigned long timeout = jiffies + (gss_key_expire_timeo * HZ);
1431         int ret = 0;
1432
1433         rcu_read_lock();
1434         ctx = rcu_dereference(gss_cred->gc_ctx);
1435         if (!ctx || time_after(timeout, ctx->gc_expiry))
1436                 ret = -EACCES;
1437         rcu_read_unlock();
1438
1439         return ret;
1440 }
1441
1442 static int
1443 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1444 {
1445         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1446         struct gss_cl_ctx *ctx;
1447         int ret;
1448
1449         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1450                 goto out;
1451         /* Don't match with creds that have expired. */
1452         rcu_read_lock();
1453         ctx = rcu_dereference(gss_cred->gc_ctx);
1454         if (!ctx || time_after(jiffies, ctx->gc_expiry)) {
1455                 rcu_read_unlock();
1456                 return 0;
1457         }
1458         rcu_read_unlock();
1459         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1460                 return 0;
1461 out:
1462         if (acred->principal != NULL) {
1463                 if (gss_cred->gc_principal == NULL)
1464                         return 0;
1465                 ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1466                 goto check_expire;
1467         }
1468         if (gss_cred->gc_principal != NULL)
1469                 return 0;
1470         ret = uid_eq(rc->cr_uid, acred->uid);
1471
1472 check_expire:
1473         if (ret == 0)
1474                 return ret;
1475
1476         /* Notify acred users of GSS context expiration timeout */
1477         if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags) &&
1478             (gss_key_timeout(rc) != 0)) {
1479                 /* test will now be done from generic cred */
1480                 test_and_clear_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
1481                 /* tell NFS layer that key will expire soon */
1482                 set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
1483         }
1484         return ret;
1485 }
1486
1487 /*
1488 * Marshal credentials.
1489 * Maybe we should keep a cached credential for performance reasons.
1490 */
1491 static __be32 *
1492 gss_marshal(struct rpc_task *task, __be32 *p)
1493 {
1494         struct rpc_rqst *req = task->tk_rqstp;
1495         struct rpc_cred *cred = req->rq_cred;
1496         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1497                                                  gc_base);
1498         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1499         __be32          *cred_len;
1500         u32             maj_stat = 0;
1501         struct xdr_netobj mic;
1502         struct kvec     iov;
1503         struct xdr_buf  verf_buf;
1504
1505         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1506
1507         *p++ = htonl(RPC_AUTH_GSS);
1508         cred_len = p++;
1509
1510         spin_lock(&ctx->gc_seq_lock);
1511         req->rq_seqno = ctx->gc_seq++;
1512         spin_unlock(&ctx->gc_seq_lock);
1513
1514         *p++ = htonl((u32) RPC_GSS_VERSION);
1515         *p++ = htonl((u32) ctx->gc_proc);
1516         *p++ = htonl((u32) req->rq_seqno);
1517         *p++ = htonl((u32) gss_cred->gc_service);
1518         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1519         *cred_len = htonl((p - (cred_len + 1)) << 2);
1520
1521         /* We compute the checksum for the verifier over the xdr-encoded bytes
1522          * starting with the xid and ending at the end of the credential: */
1523         iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
1524                                         req->rq_snd_buf.head[0].iov_base);
1525         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1526         xdr_buf_from_iov(&iov, &verf_buf);
1527
1528         /* set verifier flavor*/
1529         *p++ = htonl(RPC_AUTH_GSS);
1530
1531         mic.data = (u8 *)(p + 1);
1532         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1533         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1534                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1535         } else if (maj_stat != 0) {
1536                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1537                 goto out_put_ctx;
1538         }
1539         p = xdr_encode_opaque(p, NULL, mic.len);
1540         gss_put_ctx(ctx);
1541         return p;
1542 out_put_ctx:
1543         gss_put_ctx(ctx);
1544         return NULL;
1545 }
1546
1547 static int gss_renew_cred(struct rpc_task *task)
1548 {
1549         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1550         struct gss_cred *gss_cred = container_of(oldcred,
1551                                                  struct gss_cred,
1552                                                  gc_base);
1553         struct rpc_auth *auth = oldcred->cr_auth;
1554         struct auth_cred acred = {
1555                 .uid = oldcred->cr_uid,
1556                 .principal = gss_cred->gc_principal,
1557                 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
1558         };
1559         struct rpc_cred *new;
1560
1561         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1562         if (IS_ERR(new))
1563                 return PTR_ERR(new);
1564         task->tk_rqstp->rq_cred = new;
1565         put_rpccred(oldcred);
1566         return 0;
1567 }
1568
1569 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1570 {
1571         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1572                 unsigned long now = jiffies;
1573                 unsigned long begin, expire;
1574                 struct gss_cred *gss_cred;
1575
1576                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1577                 begin = gss_cred->gc_upcall_timestamp;
1578                 expire = begin + gss_expired_cred_retry_delay * HZ;
1579
1580                 if (time_in_range_open(now, begin, expire))
1581                         return 1;
1582         }
1583         return 0;
1584 }
1585
1586 /*
1587 * Refresh credentials. XXX - finish
1588 */
1589 static int
1590 gss_refresh(struct rpc_task *task)
1591 {
1592         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1593         int ret = 0;
1594
1595         if (gss_cred_is_negative_entry(cred))
1596                 return -EKEYEXPIRED;
1597
1598         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1599                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1600                 ret = gss_renew_cred(task);
1601                 if (ret < 0)
1602                         goto out;
1603                 cred = task->tk_rqstp->rq_cred;
1604         }
1605
1606         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1607                 ret = gss_refresh_upcall(task);
1608 out:
1609         return ret;
1610 }
1611
1612 /* Dummy refresh routine: used only when destroying the context */
1613 static int
1614 gss_refresh_null(struct rpc_task *task)
1615 {
1616         return 0;
1617 }
1618
1619 static __be32 *
1620 gss_validate(struct rpc_task *task, __be32 *p)
1621 {
1622         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1623         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1624         __be32          *seq = NULL;
1625         struct kvec     iov;
1626         struct xdr_buf  verf_buf;
1627         struct xdr_netobj mic;
1628         u32             flav,len;
1629         u32             maj_stat;
1630         __be32          *ret = ERR_PTR(-EIO);
1631
1632         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1633
1634         flav = ntohl(*p++);
1635         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1636                 goto out_bad;
1637         if (flav != RPC_AUTH_GSS)
1638                 goto out_bad;
1639         seq = kmalloc(4, GFP_NOFS);
1640         if (!seq)
1641                 goto out_bad;
1642         *seq = htonl(task->tk_rqstp->rq_seqno);
1643         iov.iov_base = seq;
1644         iov.iov_len = 4;
1645         xdr_buf_from_iov(&iov, &verf_buf);
1646         mic.data = (u8 *)p;
1647         mic.len = len;
1648
1649         ret = ERR_PTR(-EACCES);
1650         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1651         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1652                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1653         if (maj_stat) {
1654                 dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1655                         task->tk_pid, __func__, maj_stat);
1656                 goto out_bad;
1657         }
1658         /* We leave it to unwrap to calculate au_rslack. For now we just
1659          * calculate the length of the verifier: */
1660         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1661         gss_put_ctx(ctx);
1662         dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1663                         task->tk_pid, __func__);
1664         kfree(seq);
1665         return p + XDR_QUADLEN(len);
1666 out_bad:
1667         gss_put_ctx(ctx);
1668         dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
1669                 PTR_ERR(ret));
1670         kfree(seq);
1671         return ret;
1672 }
1673
1674 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1675                                 __be32 *p, void *obj)
1676 {
1677         struct xdr_stream xdr;
1678
1679         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1680         encode(rqstp, &xdr, obj);
1681 }
1682
1683 static inline int
1684 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1685                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1686                    __be32 *p, void *obj)
1687 {
1688         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1689         struct xdr_buf  integ_buf;
1690         __be32          *integ_len = NULL;
1691         struct xdr_netobj mic;
1692         u32             offset;
1693         __be32          *q;
1694         struct kvec     *iov;
1695         u32             maj_stat = 0;
1696         int             status = -EIO;
1697
1698         integ_len = p++;
1699         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1700         *p++ = htonl(rqstp->rq_seqno);
1701
1702         gss_wrap_req_encode(encode, rqstp, p, obj);
1703
1704         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1705                                 offset, snd_buf->len - offset))
1706                 return status;
1707         *integ_len = htonl(integ_buf.len);
1708
1709         /* guess whether we're in the head or the tail: */
1710         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1711                 iov = snd_buf->tail;
1712         else
1713                 iov = snd_buf->head;
1714         p = iov->iov_base + iov->iov_len;
1715         mic.data = (u8 *)(p + 1);
1716
1717         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1718         status = -EIO; /* XXX? */
1719         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1720                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1721         else if (maj_stat)
1722                 return status;
1723         q = xdr_encode_opaque(p, NULL, mic.len);
1724
1725         offset = (u8 *)q - (u8 *)p;
1726         iov->iov_len += offset;
1727         snd_buf->len += offset;
1728         return 0;
1729 }
1730
1731 static void
1732 priv_release_snd_buf(struct rpc_rqst *rqstp)
1733 {
1734         int i;
1735
1736         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1737                 __free_page(rqstp->rq_enc_pages[i]);
1738         kfree(rqstp->rq_enc_pages);
1739 }
1740
1741 static int
1742 alloc_enc_pages(struct rpc_rqst *rqstp)
1743 {
1744         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1745         int first, last, i;
1746
1747         if (snd_buf->page_len == 0) {
1748                 rqstp->rq_enc_pages_num = 0;
1749                 return 0;
1750         }
1751
1752         first = snd_buf->page_base >> PAGE_SHIFT;
1753         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_SHIFT;
1754         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1755         rqstp->rq_enc_pages
1756                 = kmalloc_array(rqstp->rq_enc_pages_num,
1757                                 sizeof(struct page *),
1758                                 GFP_NOFS);
1759         if (!rqstp->rq_enc_pages)
1760                 goto out;
1761         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1762                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1763                 if (rqstp->rq_enc_pages[i] == NULL)
1764                         goto out_free;
1765         }
1766         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1767         return 0;
1768 out_free:
1769         rqstp->rq_enc_pages_num = i;
1770         priv_release_snd_buf(rqstp);
1771 out:
1772         return -EAGAIN;
1773 }
1774
1775 static inline int
1776 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1777                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1778                   __be32 *p, void *obj)
1779 {
1780         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1781         u32             offset;
1782         u32             maj_stat;
1783         int             status;
1784         __be32          *opaque_len;
1785         struct page     **inpages;
1786         int             first;
1787         int             pad;
1788         struct kvec     *iov;
1789         char            *tmp;
1790
1791         opaque_len = p++;
1792         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1793         *p++ = htonl(rqstp->rq_seqno);
1794
1795         gss_wrap_req_encode(encode, rqstp, p, obj);
1796
1797         status = alloc_enc_pages(rqstp);
1798         if (status)
1799                 return status;
1800         first = snd_buf->page_base >> PAGE_SHIFT;
1801         inpages = snd_buf->pages + first;
1802         snd_buf->pages = rqstp->rq_enc_pages;
1803         snd_buf->page_base -= first << PAGE_SHIFT;
1804         /*
1805          * Give the tail its own page, in case we need extra space in the
1806          * head when wrapping:
1807          *
1808          * call_allocate() allocates twice the slack space required
1809          * by the authentication flavor to rq_callsize.
1810          * For GSS, slack is GSS_CRED_SLACK.
1811          */
1812         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1813                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1814                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1815                 snd_buf->tail[0].iov_base = tmp;
1816         }
1817         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1818         /* slack space should prevent this ever happening: */
1819         BUG_ON(snd_buf->len > snd_buf->buflen);
1820         status = -EIO;
1821         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1822          * done anyway, so it's safe to put the request on the wire: */
1823         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1824                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1825         else if (maj_stat)
1826                 return status;
1827
1828         *opaque_len = htonl(snd_buf->len - offset);
1829         /* guess whether we're in the head or the tail: */
1830         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1831                 iov = snd_buf->tail;
1832         else
1833                 iov = snd_buf->head;
1834         p = iov->iov_base + iov->iov_len;
1835         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1836         memset(p, 0, pad);
1837         iov->iov_len += pad;
1838         snd_buf->len += pad;
1839
1840         return 0;
1841 }
1842
1843 static int
1844 gss_wrap_req(struct rpc_task *task,
1845              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1846 {
1847         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1848         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1849                         gc_base);
1850         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1851         int             status = -EIO;
1852
1853         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1854         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1855                 /* The spec seems a little ambiguous here, but I think that not
1856                  * wrapping context destruction requests makes the most sense.
1857                  */
1858                 gss_wrap_req_encode(encode, rqstp, p, obj);
1859                 status = 0;
1860                 goto out;
1861         }
1862         switch (gss_cred->gc_service) {
1863         case RPC_GSS_SVC_NONE:
1864                 gss_wrap_req_encode(encode, rqstp, p, obj);
1865                 status = 0;
1866                 break;
1867         case RPC_GSS_SVC_INTEGRITY:
1868                 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1869                 break;
1870         case RPC_GSS_SVC_PRIVACY:
1871                 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1872                 break;
1873         }
1874 out:
1875         gss_put_ctx(ctx);
1876         dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1877         return status;
1878 }
1879
1880 static inline int
1881 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1882                 struct rpc_rqst *rqstp, __be32 **p)
1883 {
1884         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1885         struct xdr_buf integ_buf;
1886         struct xdr_netobj mic;
1887         u32 data_offset, mic_offset;
1888         u32 integ_len;
1889         u32 maj_stat;
1890         int status = -EIO;
1891
1892         integ_len = ntohl(*(*p)++);
1893         if (integ_len & 3)
1894                 return status;
1895         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1896         mic_offset = integ_len + data_offset;
1897         if (mic_offset > rcv_buf->len)
1898                 return status;
1899         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1900                 return status;
1901
1902         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1903                                 mic_offset - data_offset))
1904                 return status;
1905
1906         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1907                 return status;
1908
1909         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1910         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1911                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1912         if (maj_stat != GSS_S_COMPLETE)
1913                 return status;
1914         return 0;
1915 }
1916
1917 static inline int
1918 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1919                 struct rpc_rqst *rqstp, __be32 **p)
1920 {
1921         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1922         u32 offset;
1923         u32 opaque_len;
1924         u32 maj_stat;
1925         int status = -EIO;
1926
1927         opaque_len = ntohl(*(*p)++);
1928         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1929         if (offset + opaque_len > rcv_buf->len)
1930                 return status;
1931         /* remove padding: */
1932         rcv_buf->len = offset + opaque_len;
1933
1934         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1935         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1936                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1937         if (maj_stat != GSS_S_COMPLETE)
1938                 return status;
1939         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1940                 return status;
1941
1942         return 0;
1943 }
1944
1945 static int
1946 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1947                       __be32 *p, void *obj)
1948 {
1949         struct xdr_stream xdr;
1950
1951         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1952         return decode(rqstp, &xdr, obj);
1953 }
1954
1955 static int
1956 gss_unwrap_resp(struct rpc_task *task,
1957                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1958 {
1959         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1960         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1961                         gc_base);
1962         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1963         __be32          *savedp = p;
1964         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1965         int             savedlen = head->iov_len;
1966         int             status = -EIO;
1967
1968         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1969                 goto out_decode;
1970         switch (gss_cred->gc_service) {
1971         case RPC_GSS_SVC_NONE:
1972                 break;
1973         case RPC_GSS_SVC_INTEGRITY:
1974                 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1975                 if (status)
1976                         goto out;
1977                 break;
1978         case RPC_GSS_SVC_PRIVACY:
1979                 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1980                 if (status)
1981                         goto out;
1982                 break;
1983         }
1984         /* take into account extra slack for integrity and privacy cases: */
1985         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1986                                                 + (savedlen - head->iov_len);
1987 out_decode:
1988         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
1989 out:
1990         gss_put_ctx(ctx);
1991         dprintk("RPC: %5u %s returning %d\n",
1992                 task->tk_pid, __func__, status);
1993         return status;
1994 }
1995
1996 static const struct rpc_authops authgss_ops = {
1997         .owner          = THIS_MODULE,
1998         .au_flavor      = RPC_AUTH_GSS,
1999         .au_name        = "RPCSEC_GSS",
2000         .create         = gss_create,
2001         .destroy        = gss_destroy,
2002         .hash_cred      = gss_hash_cred,
2003         .lookup_cred    = gss_lookup_cred,
2004         .crcreate       = gss_create_cred,
2005         .list_pseudoflavors = gss_mech_list_pseudoflavors,
2006         .info2flavor    = gss_mech_info2flavor,
2007         .flavor2info    = gss_mech_flavor2info,
2008 };
2009
2010 static const struct rpc_credops gss_credops = {
2011         .cr_name                = "AUTH_GSS",
2012         .crdestroy              = gss_destroy_cred,
2013         .cr_init                = gss_cred_init,
2014         .crbind                 = rpcauth_generic_bind_cred,
2015         .crmatch                = gss_match,
2016         .crmarshal              = gss_marshal,
2017         .crrefresh              = gss_refresh,
2018         .crvalidate             = gss_validate,
2019         .crwrap_req             = gss_wrap_req,
2020         .crunwrap_resp          = gss_unwrap_resp,
2021         .crkey_timeout          = gss_key_timeout,
2022         .crstringify_acceptor   = gss_stringify_acceptor,
2023 };
2024
2025 static const struct rpc_credops gss_nullops = {
2026         .cr_name                = "AUTH_GSS",
2027         .crdestroy              = gss_destroy_nullcred,
2028         .crbind                 = rpcauth_generic_bind_cred,
2029         .crmatch                = gss_match,
2030         .crmarshal              = gss_marshal,
2031         .crrefresh              = gss_refresh_null,
2032         .crvalidate             = gss_validate,
2033         .crwrap_req             = gss_wrap_req,
2034         .crunwrap_resp          = gss_unwrap_resp,
2035         .crstringify_acceptor   = gss_stringify_acceptor,
2036 };
2037
2038 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
2039         .upcall         = rpc_pipe_generic_upcall,
2040         .downcall       = gss_pipe_downcall,
2041         .destroy_msg    = gss_pipe_destroy_msg,
2042         .open_pipe      = gss_pipe_open_v0,
2043         .release_pipe   = gss_pipe_release,
2044 };
2045
2046 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
2047         .upcall         = rpc_pipe_generic_upcall,
2048         .downcall       = gss_pipe_downcall,
2049         .destroy_msg    = gss_pipe_destroy_msg,
2050         .open_pipe      = gss_pipe_open_v1,
2051         .release_pipe   = gss_pipe_release,
2052 };
2053
2054 static __net_init int rpcsec_gss_init_net(struct net *net)
2055 {
2056         return gss_svc_init_net(net);
2057 }
2058
2059 static __net_exit void rpcsec_gss_exit_net(struct net *net)
2060 {
2061         gss_svc_shutdown_net(net);
2062 }
2063
2064 static struct pernet_operations rpcsec_gss_net_ops = {
2065         .init = rpcsec_gss_init_net,
2066         .exit = rpcsec_gss_exit_net,
2067 };
2068
2069 /*
2070  * Initialize RPCSEC_GSS module
2071  */
2072 static int __init init_rpcsec_gss(void)
2073 {
2074         int err = 0;
2075
2076         err = rpcauth_register(&authgss_ops);
2077         if (err)
2078                 goto out;
2079         err = gss_svc_init();
2080         if (err)
2081                 goto out_unregister;
2082         err = register_pernet_subsys(&rpcsec_gss_net_ops);
2083         if (err)
2084                 goto out_svc_exit;
2085         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
2086         return 0;
2087 out_svc_exit:
2088         gss_svc_shutdown();
2089 out_unregister:
2090         rpcauth_unregister(&authgss_ops);
2091 out:
2092         return err;
2093 }
2094
2095 static void __exit exit_rpcsec_gss(void)
2096 {
2097         unregister_pernet_subsys(&rpcsec_gss_net_ops);
2098         gss_svc_shutdown();
2099         rpcauth_unregister(&authgss_ops);
2100         rcu_barrier(); /* Wait for completion of call_rcu()'s */
2101 }
2102
2103 MODULE_ALIAS("rpc-auth-6");
2104 MODULE_LICENSE("GPL");
2105 module_param_named(expired_cred_retry_delay,
2106                    gss_expired_cred_retry_delay,
2107                    uint, 0644);
2108 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
2109                 "the RPC engine retries an expired credential");
2110
2111 module_param_named(key_expire_timeo,
2112                    gss_key_expire_timeo,
2113                    uint, 0644);
2114 MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
2115                 "credential keys lifetime where the NFS layer cleans up "
2116                 "prior to key expiration");
2117
2118 module_init(init_rpcsec_gss)
2119 module_exit(exit_rpcsec_gss)