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 /* XXX: Need some documentation about why UPCALL_BUF_LEN is so small.
 288  *      Is user space expecting no more than UPCALL_BUF_LEN bytes?
 289  *      Note that there are now _two_ NI_MAXHOST sized data items
 290  *      being passed in this string.
 291  */
 292 #define UPCALL_BUF_LEN  256
 293
 294 struct gss_upcall_msg {
 295         refcount_t count;
 296         kuid_t  uid;
 297         struct rpc_pipe_msg msg;
 298         struct list_head list;
 299         struct gss_auth *auth;
 300         struct rpc_pipe *pipe;
 301         struct rpc_wait_queue rpc_waitqueue;
 302         wait_queue_head_t waitqueue;
 303         struct gss_cl_ctx *ctx;
 304         char databuf[UPCALL_BUF_LEN];
 305 };
 306
 307 static int get_pipe_version(struct net *net)
 308 {
 309         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 310         int ret;
 311
 312         spin_lock(&pipe_version_lock);
 313         if (sn->pipe_version >= 0) {
 314                 atomic_inc(&sn->pipe_users);
 315                 ret = sn->pipe_version;
 316         } else
 317                 ret = -EAGAIN;
 318         spin_unlock(&pipe_version_lock);
 319         return ret;
 320 }
 321
 322 static void put_pipe_version(struct net *net)
 323 {
 324         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 325
 326         if (atomic_dec_and_lock(&sn->pipe_users, &pipe_version_lock)) {
 327                 sn->pipe_version = -1;
 328                 spin_unlock(&pipe_version_lock);
 329         }
 330 }
 331
 332 static void
 333 gss_release_msg(struct gss_upcall_msg *gss_msg)
 334 {
 335         struct net *net = gss_msg->auth->net;
 336         if (!refcount_dec_and_test(&gss_msg->count))
 337                 return;
 338         put_pipe_version(net);
 339         BUG_ON(!list_empty(&gss_msg->list));
 340         if (gss_msg->ctx != NULL)
 341                 gss_put_ctx(gss_msg->ctx);
 342         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 343         gss_put_auth(gss_msg->auth);
 344         kfree(gss_msg);
 345 }
 346
 347 static struct gss_upcall_msg *
 348 __gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid, const struct gss_auth *auth)
 349 {
 350         struct gss_upcall_msg *pos;
 351         list_for_each_entry(pos, &pipe->in_downcall, list) {
 352                 if (!uid_eq(pos->uid, uid))
 353                         continue;
 354                 if (auth && pos->auth->service != auth->service)
 355                         continue;
 356                 refcount_inc(&pos->count);
 357                 dprintk("RPC:       %s found msg %p\n", __func__, pos);
 358                 return pos;
 359         }
 360         dprintk("RPC:       %s found nothing\n", __func__);
 361         return NULL;
 362 }
 363
 364 /* Try to add an upcall to the pipefs queue.
 365  * If an upcall owned by our uid already exists, then we return a reference
 366  * to that upcall instead of adding the new upcall.
 367  */
 368 static inline struct gss_upcall_msg *
 369 gss_add_msg(struct gss_upcall_msg *gss_msg)
 370 {
 371         struct rpc_pipe *pipe = gss_msg->pipe;
 372         struct gss_upcall_msg *old;
 373
 374         spin_lock(&pipe->lock);
 375         old = __gss_find_upcall(pipe, gss_msg->uid, gss_msg->auth);
 376         if (old == NULL) {
 377                 refcount_inc(&gss_msg->count);
 378                 list_add(&gss_msg->list, &pipe->in_downcall);
 379         } else
 380                 gss_msg = old;
 381         spin_unlock(&pipe->lock);
 382         return gss_msg;
 383 }
 384
 385 static void
 386 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 387 {
 388         list_del_init(&gss_msg->list);
 389         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 390         wake_up_all(&gss_msg->waitqueue);
 391         refcount_dec(&gss_msg->count);
 392 }
 393
 394 static void
 395 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 396 {
 397         struct rpc_pipe *pipe = gss_msg->pipe;
 398
 399         if (list_empty(&gss_msg->list))
 400                 return;
 401         spin_lock(&pipe->lock);
 402         if (!list_empty(&gss_msg->list))
 403                 __gss_unhash_msg(gss_msg);
 404         spin_unlock(&pipe->lock);
 405 }
 406
 407 static void
 408 gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
 409 {
 410         switch (gss_msg->msg.errno) {
 411         case 0:
 412                 if (gss_msg->ctx == NULL)
 413                         break;
 414                 clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 415                 gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
 416                 break;
 417         case -EKEYEXPIRED:
 418                 set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 419         }
 420         gss_cred->gc_upcall_timestamp = jiffies;
 421         gss_cred->gc_upcall = NULL;
 422         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 423 }
 424
 425 static void
 426 gss_upcall_callback(struct rpc_task *task)
 427 {
 428         struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
 429                         struct gss_cred, gc_base);
 430         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 431         struct rpc_pipe *pipe = gss_msg->pipe;
 432
 433         spin_lock(&pipe->lock);
 434         gss_handle_downcall_result(gss_cred, gss_msg);
 435         spin_unlock(&pipe->lock);
 436         task->tk_status = gss_msg->msg.errno;
 437         gss_release_msg(gss_msg);
 438 }
 439
 440 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
 441 {
 442         uid_t uid = from_kuid(&init_user_ns, gss_msg->uid);
 443         memcpy(gss_msg->databuf, &uid, sizeof(uid));
 444         gss_msg->msg.data = gss_msg->databuf;
 445         gss_msg->msg.len = sizeof(uid);
 446
 447         BUILD_BUG_ON(sizeof(uid) > sizeof(gss_msg->databuf));
 448 }
 449
 450 static int gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
 451                                 const char *service_name,
 452                                 const char *target_name)
 453 {
 454         struct gss_api_mech *mech = gss_msg->auth->mech;
 455         char *p = gss_msg->databuf;
 456         size_t buflen = sizeof(gss_msg->databuf);
 457         int len;
 458
 459         len = scnprintf(p, buflen, "mech=%s uid=%d ", mech->gm_name,
 460                         from_kuid(&init_user_ns, gss_msg->uid));
 461         buflen -= len;
 462         p += len;
 463         gss_msg->msg.len = len;
 464
 465         /*
 466          * target= is a full service principal that names the remote
 467          * identity that we are authenticating to.
 468          */
 469         if (target_name) {
 470                 len = scnprintf(p, buflen, "target=%s ", target_name);
 471                 buflen -= len;
 472                 p += len;
 473                 gss_msg->msg.len += len;
 474         }
 475
 476         /*
 477          * gssd uses service= and srchost= to select a matching key from
 478          * the system's keytab to use as the source principal.
 479          *
 480          * service= is the service name part of the source principal,
 481          * or "*" (meaning choose any).
 482          *
 483          * srchost= is the hostname part of the source principal. When
 484          * not provided, gssd uses the local hostname.
 485          */
 486         if (service_name) {
 487                 char *c = strchr(service_name, '@');
 488
 489                 if (!c)
 490                         len = scnprintf(p, buflen, "service=%s ",
 491                                         service_name);
 492                 else
 493                         len = scnprintf(p, buflen,
 494                                         "service=%.*s srchost=%s ",
 495                                         (int)(c - service_name),
 496                                         service_name, c + 1);
 497                 buflen -= len;
 498                 p += len;
 499                 gss_msg->msg.len += len;
 500         }
 501
 502         if (mech->gm_upcall_enctypes) {
 503                 len = scnprintf(p, buflen, "enctypes=%s ",
 504                                 mech->gm_upcall_enctypes);
 505                 buflen -= len;
 506                 p += len;
 507                 gss_msg->msg.len += len;
 508         }
 509         len = scnprintf(p, buflen, "\n");
 510         if (len == 0)
 511                 goto out_overflow;
 512         gss_msg->msg.len += len;
 513
 514         gss_msg->msg.data = gss_msg->databuf;
 515         return 0;
 516 out_overflow:
 517         WARN_ON_ONCE(1);
 518         return -ENOMEM;
 519 }
 520
 521 static struct gss_upcall_msg *
 522 gss_alloc_msg(struct gss_auth *gss_auth,
 523                 kuid_t uid, const char *service_name)
 524 {
 525         struct gss_upcall_msg *gss_msg;
 526         int vers;
 527         int err = -ENOMEM;
 528
 529         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 530         if (gss_msg == NULL)
 531                 goto err;
 532         vers = get_pipe_version(gss_auth->net);
 533         err = vers;
 534         if (err < 0)
 535                 goto err_free_msg;
 536         gss_msg->pipe = gss_auth->gss_pipe[vers]->pipe;
 537         INIT_LIST_HEAD(&gss_msg->list);
 538         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 539         init_waitqueue_head(&gss_msg->waitqueue);
 540         refcount_set(&gss_msg->count, 1);
 541         gss_msg->uid = uid;
 542         gss_msg->auth = gss_auth;
 543         switch (vers) {
 544         case 0:
 545                 gss_encode_v0_msg(gss_msg);
 546                 break;
 547         default:
 548                 err = gss_encode_v1_msg(gss_msg, service_name, gss_auth->target_name);
 549                 if (err)
 550                         goto err_put_pipe_version;
 551         }
 552         kref_get(&gss_auth->kref);
 553         return gss_msg;
 554 err_put_pipe_version:
 555         put_pipe_version(gss_auth->net);
 556 err_free_msg:
 557         kfree(gss_msg);
 558 err:
 559         return ERR_PTR(err);
 560 }
 561
 562 static struct gss_upcall_msg *
 563 gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred)
 564 {
 565         struct gss_cred *gss_cred = container_of(cred,
 566                         struct gss_cred, gc_base);
 567         struct gss_upcall_msg *gss_new, *gss_msg;
 568         kuid_t uid = cred->cr_cred->fsuid;
 569
 570         gss_new = gss_alloc_msg(gss_auth, uid, gss_cred->gc_principal);
 571         if (IS_ERR(gss_new))
 572                 return gss_new;
 573         gss_msg = gss_add_msg(gss_new);
 574         if (gss_msg == gss_new) {
 575                 int res;
 576                 refcount_inc(&gss_msg->count);
 577                 res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
 578                 if (res) {
 579                         gss_unhash_msg(gss_new);
 580                         refcount_dec(&gss_msg->count);
 581                         gss_release_msg(gss_new);
 582                         gss_msg = ERR_PTR(res);
 583                 }
 584         } else
 585                 gss_release_msg(gss_new);
 586         return gss_msg;
 587 }
 588
 589 static void warn_gssd(void)
 590 {
 591         dprintk("AUTH_GSS upcall failed. Please check user daemon is running.\n");
 592 }
 593
 594 static inline int
 595 gss_refresh_upcall(struct rpc_task *task)
 596 {
 597         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 598         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 599                         struct gss_auth, rpc_auth);
 600         struct gss_cred *gss_cred = container_of(cred,
 601                         struct gss_cred, gc_base);
 602         struct gss_upcall_msg *gss_msg;
 603         struct rpc_pipe *pipe;
 604         int err = 0;
 605
 606         dprintk("RPC: %5u %s for uid %u\n",
 607                 task->tk_pid, __func__, from_kuid(&init_user_ns, cred->cr_cred->fsuid));
 608         gss_msg = gss_setup_upcall(gss_auth, cred);
 609         if (PTR_ERR(gss_msg) == -EAGAIN) {
 610                 /* XXX: warning on the first, under the assumption we
 611                  * shouldn't normally hit this case on a refresh. */
 612                 warn_gssd();
 613                 task->tk_timeout = 15*HZ;
 614                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
 615                 return -EAGAIN;
 616         }
 617         if (IS_ERR(gss_msg)) {
 618                 err = PTR_ERR(gss_msg);
 619                 goto out;
 620         }
 621         pipe = gss_msg->pipe;
 622         spin_lock(&pipe->lock);
 623         if (gss_cred->gc_upcall != NULL)
 624                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 625         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 626                 task->tk_timeout = 0;
 627                 gss_cred->gc_upcall = gss_msg;
 628                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 629                 refcount_inc(&gss_msg->count);
 630                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 631         } else {
 632                 gss_handle_downcall_result(gss_cred, gss_msg);
 633                 err = gss_msg->msg.errno;
 634         }
 635         spin_unlock(&pipe->lock);
 636         gss_release_msg(gss_msg);
 637 out:
 638         dprintk("RPC: %5u %s for uid %u result %d\n",
 639                 task->tk_pid, __func__,
 640                 from_kuid(&init_user_ns, cred->cr_cred->fsuid), err);
 641         return err;
 642 }
 643
 644 static inline int
 645 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 646 {
 647         struct net *net = gss_auth->net;
 648         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 649         struct rpc_pipe *pipe;
 650         struct rpc_cred *cred = &gss_cred->gc_base;
 651         struct gss_upcall_msg *gss_msg;
 652         DEFINE_WAIT(wait);
 653         int err;
 654
 655         dprintk("RPC:       %s for uid %u\n",
 656                 __func__, from_kuid(&init_user_ns, cred->cr_cred->fsuid));
 657 retry:
 658         err = 0;
 659         /* if gssd is down, just skip upcalling altogether */
 660         if (!gssd_running(net)) {
 661                 warn_gssd();
 662                 return -EACCES;
 663         }
 664         gss_msg = gss_setup_upcall(gss_auth, cred);
 665         if (PTR_ERR(gss_msg) == -EAGAIN) {
 666                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
 667                                 sn->pipe_version >= 0, 15 * HZ);
 668                 if (sn->pipe_version < 0) {
 669                         warn_gssd();
 670                         err = -EACCES;
 671                 }
 672                 if (err < 0)
 673                         goto out;
 674                 goto retry;
 675         }
 676         if (IS_ERR(gss_msg)) {
 677                 err = PTR_ERR(gss_msg);
 678                 goto out;
 679         }
 680         pipe = gss_msg->pipe;
 681         for (;;) {
 682                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
 683                 spin_lock(&pipe->lock);
 684                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 685                         break;
 686                 }
 687                 spin_unlock(&pipe->lock);
 688                 if (fatal_signal_pending(current)) {
 689                         err = -ERESTARTSYS;
 690                         goto out_intr;
 691                 }
 692                 schedule();
 693         }
 694         if (gss_msg->ctx)
 695                 gss_cred_set_ctx(cred, gss_msg->ctx);
 696         else
 697                 err = gss_msg->msg.errno;
 698         spin_unlock(&pipe->lock);
 699 out_intr:
 700         finish_wait(&gss_msg->waitqueue, &wait);
 701         gss_release_msg(gss_msg);
 702 out:
 703         dprintk("RPC:       %s for uid %u result %d\n",
 704                 __func__, from_kuid(&init_user_ns, cred->cr_cred->fsuid), err);
 705         return err;
 706 }
 707
 708 #define MSG_BUF_MAXSIZE 1024
 709
 710 static ssize_t
 711 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 712 {
 713         const void *p, *end;
 714         void *buf;
 715         struct gss_upcall_msg *gss_msg;
 716         struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
 717         struct gss_cl_ctx *ctx;
 718         uid_t id;
 719         kuid_t uid;
 720         ssize_t err = -EFBIG;
 721
 722         if (mlen > MSG_BUF_MAXSIZE)
 723                 goto out;
 724         err = -ENOMEM;
 725         buf = kmalloc(mlen, GFP_NOFS);
 726         if (!buf)
 727                 goto out;
 728
 729         err = -EFAULT;
 730         if (copy_from_user(buf, src, mlen))
 731                 goto err;
 732
 733         end = (const void *)((char *)buf + mlen);
 734         p = simple_get_bytes(buf, end, &id, sizeof(id));
 735         if (IS_ERR(p)) {
 736                 err = PTR_ERR(p);
 737                 goto err;
 738         }
 739
 740         uid = make_kuid(&init_user_ns, id);
 741         if (!uid_valid(uid)) {
 742                 err = -EINVAL;
 743                 goto err;
 744         }
 745
 746         err = -ENOMEM;
 747         ctx = gss_alloc_context();
 748         if (ctx == NULL)
 749                 goto err;
 750
 751         err = -ENOENT;
 752         /* Find a matching upcall */
 753         spin_lock(&pipe->lock);
 754         gss_msg = __gss_find_upcall(pipe, uid, NULL);
 755         if (gss_msg == NULL) {
 756                 spin_unlock(&pipe->lock);
 757                 goto err_put_ctx;
 758         }
 759         list_del_init(&gss_msg->list);
 760         spin_unlock(&pipe->lock);
 761
 762         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 763         if (IS_ERR(p)) {
 764                 err = PTR_ERR(p);
 765                 switch (err) {
 766                 case -EACCES:
 767                 case -EKEYEXPIRED:
 768                         gss_msg->msg.errno = err;
 769                         err = mlen;
 770                         break;
 771                 case -EFAULT:
 772                 case -ENOMEM:
 773                 case -EINVAL:
 774                 case -ENOSYS:
 775                         gss_msg->msg.errno = -EAGAIN;
 776                         break;
 777                 default:
 778                         printk(KERN_CRIT "%s: bad return from "
 779                                 "gss_fill_context: %zd\n", __func__, err);
 780                         gss_msg->msg.errno = -EIO;
 781                 }
 782                 goto err_release_msg;
 783         }
 784         gss_msg->ctx = gss_get_ctx(ctx);
 785         err = mlen;
 786
 787 err_release_msg:
 788         spin_lock(&pipe->lock);
 789         __gss_unhash_msg(gss_msg);
 790         spin_unlock(&pipe->lock);
 791         gss_release_msg(gss_msg);
 792 err_put_ctx:
 793         gss_put_ctx(ctx);
 794 err:
 795         kfree(buf);
 796 out:
 797         dprintk("RPC:       %s returning %zd\n", __func__, err);
 798         return err;
 799 }
 800
 801 static int gss_pipe_open(struct inode *inode, int new_version)
 802 {
 803         struct net *net = inode->i_sb->s_fs_info;
 804         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 805         int ret = 0;
 806
 807         spin_lock(&pipe_version_lock);
 808         if (sn->pipe_version < 0) {
 809                 /* First open of any gss pipe determines the version: */
 810                 sn->pipe_version = new_version;
 811                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 812                 wake_up(&pipe_version_waitqueue);
 813         } else if (sn->pipe_version != new_version) {
 814                 /* Trying to open a pipe of a different version */
 815                 ret = -EBUSY;
 816                 goto out;
 817         }
 818         atomic_inc(&sn->pipe_users);
 819 out:
 820         spin_unlock(&pipe_version_lock);
 821         return ret;
 822
 823 }
 824
 825 static int gss_pipe_open_v0(struct inode *inode)
 826 {
 827         return gss_pipe_open(inode, 0);
 828 }
 829
 830 static int gss_pipe_open_v1(struct inode *inode)
 831 {
 832         return gss_pipe_open(inode, 1);
 833 }
 834
 835 static void
 836 gss_pipe_release(struct inode *inode)
 837 {
 838         struct net *net = inode->i_sb->s_fs_info;
 839         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 840         struct gss_upcall_msg *gss_msg;
 841
 842 restart:
 843         spin_lock(&pipe->lock);
 844         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
 845
 846                 if (!list_empty(&gss_msg->msg.list))
 847                         continue;
 848                 gss_msg->msg.errno = -EPIPE;
 849                 refcount_inc(&gss_msg->count);
 850                 __gss_unhash_msg(gss_msg);
 851                 spin_unlock(&pipe->lock);
 852                 gss_release_msg(gss_msg);
 853                 goto restart;
 854         }
 855         spin_unlock(&pipe->lock);
 856
 857         put_pipe_version(net);
 858 }
 859
 860 static void
 861 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 862 {
 863         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 864
 865         if (msg->errno < 0) {
 866                 dprintk("RPC:       %s releasing msg %p\n",
 867                         __func__, gss_msg);
 868                 refcount_inc(&gss_msg->count);
 869                 gss_unhash_msg(gss_msg);
 870                 if (msg->errno == -ETIMEDOUT)
 871                         warn_gssd();
 872                 gss_release_msg(gss_msg);
 873         }
 874         gss_release_msg(gss_msg);
 875 }
 876
 877 static void gss_pipe_dentry_destroy(struct dentry *dir,
 878                 struct rpc_pipe_dir_object *pdo)
 879 {
 880         struct gss_pipe *gss_pipe = pdo->pdo_data;
 881         struct rpc_pipe *pipe = gss_pipe->pipe;
 882
 883         if (pipe->dentry != NULL) {
 884                 rpc_unlink(pipe->dentry);
 885                 pipe->dentry = NULL;
 886         }
 887 }
 888
 889 static int gss_pipe_dentry_create(struct dentry *dir,
 890                 struct rpc_pipe_dir_object *pdo)
 891 {
 892         struct gss_pipe *p = pdo->pdo_data;
 893         struct dentry *dentry;
 894
 895         dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
 896         if (IS_ERR(dentry))
 897                 return PTR_ERR(dentry);
 898         p->pipe->dentry = dentry;
 899         return 0;
 900 }
 901
 902 static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
 903         .create = gss_pipe_dentry_create,
 904         .destroy = gss_pipe_dentry_destroy,
 905 };
 906
 907 static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
 908                 const char *name,
 909                 const struct rpc_pipe_ops *upcall_ops)
 910 {
 911         struct gss_pipe *p;
 912         int err = -ENOMEM;
 913
 914         p = kmalloc(sizeof(*p), GFP_KERNEL);
 915         if (p == NULL)
 916                 goto err;
 917         p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 918         if (IS_ERR(p->pipe)) {
 919                 err = PTR_ERR(p->pipe);
 920                 goto err_free_gss_pipe;
 921         }
 922         p->name = name;
 923         p->clnt = clnt;
 924         kref_init(&p->kref);
 925         rpc_init_pipe_dir_object(&p->pdo,
 926                         &gss_pipe_dir_object_ops,
 927                         p);
 928         return p;
 929 err_free_gss_pipe:
 930         kfree(p);
 931 err:
 932         return ERR_PTR(err);
 933 }
 934
 935 struct gss_alloc_pdo {
 936         struct rpc_clnt *clnt;
 937         const char *name;
 938         const struct rpc_pipe_ops *upcall_ops;
 939 };
 940
 941 static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
 942 {
 943         struct gss_pipe *gss_pipe;
 944         struct gss_alloc_pdo *args = data;
 945
 946         if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
 947                 return 0;
 948         gss_pipe = container_of(pdo, struct gss_pipe, pdo);
 949         if (strcmp(gss_pipe->name, args->name) != 0)
 950                 return 0;
 951         if (!kref_get_unless_zero(&gss_pipe->kref))
 952                 return 0;
 953         return 1;
 954 }
 955
 956 static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
 957 {
 958         struct gss_pipe *gss_pipe;
 959         struct gss_alloc_pdo *args = data;
 960
 961         gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
 962         if (!IS_ERR(gss_pipe))
 963                 return &gss_pipe->pdo;
 964         return NULL;
 965 }
 966
 967 static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
 968                 const char *name,
 969                 const struct rpc_pipe_ops *upcall_ops)
 970 {
 971         struct net *net = rpc_net_ns(clnt);
 972         struct rpc_pipe_dir_object *pdo;
 973         struct gss_alloc_pdo args = {
 974                 .clnt = clnt,
 975                 .name = name,
 976                 .upcall_ops = upcall_ops,
 977         };
 978
 979         pdo = rpc_find_or_alloc_pipe_dir_object(net,
 980                         &clnt->cl_pipedir_objects,
 981                         gss_pipe_match_pdo,
 982                         gss_pipe_alloc_pdo,
 983                         &args);
 984         if (pdo != NULL)
 985                 return container_of(pdo, struct gss_pipe, pdo);
 986         return ERR_PTR(-ENOMEM);
 987 }
 988
 989 static void __gss_pipe_free(struct gss_pipe *p)
 990 {
 991         struct rpc_clnt *clnt = p->clnt;
 992         struct net *net = rpc_net_ns(clnt);
 993
 994         rpc_remove_pipe_dir_object(net,
 995                         &clnt->cl_pipedir_objects,
 996                         &p->pdo);
 997         rpc_destroy_pipe_data(p->pipe);
 998         kfree(p);
 999 }
1000
1001 static void __gss_pipe_release(struct kref *kref)
1002 {
1003         struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
1004
1005         __gss_pipe_free(p);
1006 }
1007
1008 static void gss_pipe_free(struct gss_pipe *p)
1009 {
1010         if (p != NULL)
1011                 kref_put(&p->kref, __gss_pipe_release);
1012 }
1013
1014 /*
1015  * NOTE: we have the opportunity to use different
1016  * parameters based on the input flavor (which must be a pseudoflavor)
1017  */
1018 static struct gss_auth *
1019 gss_create_new(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1020 {
1021         rpc_authflavor_t flavor = args->pseudoflavor;
1022         struct gss_auth *gss_auth;
1023         struct gss_pipe *gss_pipe;
1024         struct rpc_auth * auth;
1025         int err = -ENOMEM; /* XXX? */
1026
1027         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
1028
1029         if (!try_module_get(THIS_MODULE))
1030                 return ERR_PTR(err);
1031         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
1032                 goto out_dec;
1033         INIT_HLIST_NODE(&gss_auth->hash);
1034         gss_auth->target_name = NULL;
1035         if (args->target_name) {
1036                 gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
1037                 if (gss_auth->target_name == NULL)
1038                         goto err_free;
1039         }
1040         gss_auth->client = clnt;
1041         gss_auth->net = get_net(rpc_net_ns(clnt));
1042         err = -EINVAL;
1043         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
1044         if (!gss_auth->mech) {
1045                 dprintk("RPC:       Pseudoflavor %d not found!\n", flavor);
1046                 goto err_put_net;
1047         }
1048         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
1049         if (gss_auth->service == 0)
1050                 goto err_put_mech;
1051         if (!gssd_running(gss_auth->net))
1052                 goto err_put_mech;
1053         auth = &gss_auth->rpc_auth;
1054         auth->au_cslack = GSS_CRED_SLACK >> 2;
1055         auth->au_rslack = GSS_VERF_SLACK >> 2;
1056         auth->au_flags = 0;
1057         auth->au_ops = &authgss_ops;
1058         auth->au_flavor = flavor;
1059         if (gss_pseudoflavor_to_datatouch(gss_auth->mech, flavor))
1060                 auth->au_flags |= RPCAUTH_AUTH_DATATOUCH;
1061         refcount_set(&auth->au_count, 1);
1062         kref_init(&gss_auth->kref);
1063
1064         err = rpcauth_init_credcache(auth);
1065         if (err)
1066                 goto err_put_mech;
1067         /*
1068          * Note: if we created the old pipe first, then someone who
1069          * examined the directory at the right moment might conclude
1070          * that we supported only the old pipe.  So we instead create
1071          * the new pipe first.
1072          */
1073         gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
1074         if (IS_ERR(gss_pipe)) {
1075                 err = PTR_ERR(gss_pipe);
1076                 goto err_destroy_credcache;
1077         }
1078         gss_auth->gss_pipe[1] = gss_pipe;
1079
1080         gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
1081                         &gss_upcall_ops_v0);
1082         if (IS_ERR(gss_pipe)) {
1083                 err = PTR_ERR(gss_pipe);
1084                 goto err_destroy_pipe_1;
1085         }
1086         gss_auth->gss_pipe[0] = gss_pipe;
1087
1088         return gss_auth;
1089 err_destroy_pipe_1:
1090         gss_pipe_free(gss_auth->gss_pipe[1]);
1091 err_destroy_credcache:
1092         rpcauth_destroy_credcache(auth);
1093 err_put_mech:
1094         gss_mech_put(gss_auth->mech);
1095 err_put_net:
1096         put_net(gss_auth->net);
1097 err_free:
1098         kfree(gss_auth->target_name);
1099         kfree(gss_auth);
1100 out_dec:
1101         module_put(THIS_MODULE);
1102         return ERR_PTR(err);
1103 }
1104
1105 static void
1106 gss_free(struct gss_auth *gss_auth)
1107 {
1108         gss_pipe_free(gss_auth->gss_pipe[0]);
1109         gss_pipe_free(gss_auth->gss_pipe[1]);
1110         gss_mech_put(gss_auth->mech);
1111         put_net(gss_auth->net);
1112         kfree(gss_auth->target_name);
1113
1114         kfree(gss_auth);
1115         module_put(THIS_MODULE);
1116 }
1117
1118 static void
1119 gss_free_callback(struct kref *kref)
1120 {
1121         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1122
1123         gss_free(gss_auth);
1124 }
1125
1126 static void
1127 gss_put_auth(struct gss_auth *gss_auth)
1128 {
1129         kref_put(&gss_auth->kref, gss_free_callback);
1130 }
1131
1132 static void
1133 gss_destroy(struct rpc_auth *auth)
1134 {
1135         struct gss_auth *gss_auth = container_of(auth,
1136                         struct gss_auth, rpc_auth);
1137
1138         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
1139                         auth, auth->au_flavor);
1140
1141         if (hash_hashed(&gss_auth->hash)) {
1142                 spin_lock(&gss_auth_hash_lock);
1143                 hash_del(&gss_auth->hash);
1144                 spin_unlock(&gss_auth_hash_lock);
1145         }
1146
1147         gss_pipe_free(gss_auth->gss_pipe[0]);
1148         gss_auth->gss_pipe[0] = NULL;
1149         gss_pipe_free(gss_auth->gss_pipe[1]);
1150         gss_auth->gss_pipe[1] = NULL;
1151         rpcauth_destroy_credcache(auth);
1152
1153         gss_put_auth(gss_auth);
1154 }
1155
1156 /*
1157  * Auths may be shared between rpc clients that were cloned from a
1158  * common client with the same xprt, if they also share the flavor and
1159  * target_name.
1160  *
1161  * The auth is looked up from the oldest parent sharing the same
1162  * cl_xprt, and the auth itself references only that common parent
1163  * (which is guaranteed to last as long as any of its descendants).
1164  */
1165 static struct gss_auth *
1166 gss_auth_find_or_add_hashed(const struct rpc_auth_create_args *args,
1167                 struct rpc_clnt *clnt,
1168                 struct gss_auth *new)
1169 {
1170         struct gss_auth *gss_auth;
1171         unsigned long hashval = (unsigned long)clnt;
1172
1173         spin_lock(&gss_auth_hash_lock);
1174         hash_for_each_possible(gss_auth_hash_table,
1175                         gss_auth,
1176                         hash,
1177                         hashval) {
1178                 if (gss_auth->client != clnt)
1179                         continue;
1180                 if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1181                         continue;
1182                 if (gss_auth->target_name != args->target_name) {
1183                         if (gss_auth->target_name == NULL)
1184                                 continue;
1185                         if (args->target_name == NULL)
1186                                 continue;
1187                         if (strcmp(gss_auth->target_name, args->target_name))
1188                                 continue;
1189                 }
1190                 if (!refcount_inc_not_zero(&gss_auth->rpc_auth.au_count))
1191                         continue;
1192                 goto out;
1193         }
1194         if (new)
1195                 hash_add(gss_auth_hash_table, &new->hash, hashval);
1196         gss_auth = new;
1197 out:
1198         spin_unlock(&gss_auth_hash_lock);
1199         return gss_auth;
1200 }
1201
1202 static struct gss_auth *
1203 gss_create_hashed(const struct rpc_auth_create_args *args,
1204                   struct rpc_clnt *clnt)
1205 {
1206         struct gss_auth *gss_auth;
1207         struct gss_auth *new;
1208
1209         gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1210         if (gss_auth != NULL)
1211                 goto out;
1212         new = gss_create_new(args, clnt);
1213         if (IS_ERR(new))
1214                 return new;
1215         gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1216         if (gss_auth != new)
1217                 gss_destroy(&new->rpc_auth);
1218 out:
1219         return gss_auth;
1220 }
1221
1222 static struct rpc_auth *
1223 gss_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1224 {
1225         struct gss_auth *gss_auth;
1226         struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
1227
1228         while (clnt != clnt->cl_parent) {
1229                 struct rpc_clnt *parent = clnt->cl_parent;
1230                 /* Find the original parent for this transport */
1231                 if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
1232                         break;
1233                 clnt = parent;
1234         }
1235
1236         gss_auth = gss_create_hashed(args, clnt);
1237         if (IS_ERR(gss_auth))
1238                 return ERR_CAST(gss_auth);
1239         return &gss_auth->rpc_auth;
1240 }
1241
1242 static struct gss_cred *
1243 gss_dup_cred(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
1244 {
1245         struct gss_cred *new;
1246
1247         /* Make a copy of the cred so that we can reference count it */
1248         new = kzalloc(sizeof(*gss_cred), GFP_NOIO);
1249         if (new) {
1250                 struct auth_cred acred = {
1251                         .cred = gss_cred->gc_base.cr_cred,
1252                 };
1253                 struct gss_cl_ctx *ctx =
1254                         rcu_dereference_protected(gss_cred->gc_ctx, 1);
1255
1256                 rpcauth_init_cred(&new->gc_base, &acred,
1257                                 &gss_auth->rpc_auth,
1258                                 &gss_nullops);
1259                 new->gc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
1260                 new->gc_service = gss_cred->gc_service;
1261                 new->gc_principal = gss_cred->gc_principal;
1262                 kref_get(&gss_auth->kref);
1263                 rcu_assign_pointer(new->gc_ctx, ctx);
1264                 gss_get_ctx(ctx);
1265         }
1266         return new;
1267 }
1268
1269 /*
1270  * gss_send_destroy_context will cause the RPCSEC_GSS to send a NULL RPC call
1271  * to the server with the GSS control procedure field set to
1272  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1273  * all RPCSEC_GSS state associated with that context.
1274  */
1275 static void
1276 gss_send_destroy_context(struct rpc_cred *cred)
1277 {
1278         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1279         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1280         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1281         struct gss_cred *new;
1282         struct rpc_task *task;
1283
1284         new = gss_dup_cred(gss_auth, gss_cred);
1285         if (new) {
1286                 ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1287
1288                 task = rpc_call_null(gss_auth->client, &new->gc_base,
1289                                 RPC_TASK_ASYNC|RPC_TASK_SOFT);
1290                 if (!IS_ERR(task))
1291                         rpc_put_task(task);
1292
1293                 put_rpccred(&new->gc_base);
1294         }
1295 }
1296
1297 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1298  * to create a new cred or context, so they check that things have been
1299  * allocated before freeing them. */
1300 static void
1301 gss_do_free_ctx(struct gss_cl_ctx *ctx)
1302 {
1303         dprintk("RPC:       %s\n", __func__);
1304
1305         gss_delete_sec_context(&ctx->gc_gss_ctx);
1306         kfree(ctx->gc_wire_ctx.data);
1307         kfree(ctx->gc_acceptor.data);
1308         kfree(ctx);
1309 }
1310
1311 static void
1312 gss_free_ctx_callback(struct rcu_head *head)
1313 {
1314         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1315         gss_do_free_ctx(ctx);
1316 }
1317
1318 static void
1319 gss_free_ctx(struct gss_cl_ctx *ctx)
1320 {
1321         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1322 }
1323
1324 static void
1325 gss_free_cred(struct gss_cred *gss_cred)
1326 {
1327         dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1328         kfree(gss_cred);
1329 }
1330
1331 static void
1332 gss_free_cred_callback(struct rcu_head *head)
1333 {
1334         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1335         gss_free_cred(gss_cred);
1336 }
1337
1338 static void
1339 gss_destroy_nullcred(struct rpc_cred *cred)
1340 {
1341         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1342         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1343         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1344
1345         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1346         put_cred(cred->cr_cred);
1347         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1348         if (ctx)
1349                 gss_put_ctx(ctx);
1350         gss_put_auth(gss_auth);
1351 }
1352
1353 static void
1354 gss_destroy_cred(struct rpc_cred *cred)
1355 {
1356
1357         if (test_and_clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0)
1358                 gss_send_destroy_context(cred);
1359         gss_destroy_nullcred(cred);
1360 }
1361
1362 static int
1363 gss_hash_cred(struct auth_cred *acred, unsigned int hashbits)
1364 {
1365         return hash_64(from_kuid(&init_user_ns, acred->cred->fsuid), hashbits);
1366 }
1367
1368 /*
1369  * Lookup RPCSEC_GSS cred for the current process
1370  */
1371 static struct rpc_cred *
1372 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1373 {
1374         return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS);
1375 }
1376
1377 static struct rpc_cred *
1378 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp)
1379 {
1380         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1381         struct gss_cred *cred = NULL;
1382         int err = -ENOMEM;
1383
1384         dprintk("RPC:       %s for uid %d, flavor %d\n",
1385                 __func__, from_kuid(&init_user_ns, acred->cred->fsuid),
1386                 auth->au_flavor);
1387
1388         if (!(cred = kzalloc(sizeof(*cred), gfp)))
1389                 goto out_err;
1390
1391         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1392         /*
1393          * Note: in order to force a call to call_refresh(), we deliberately
1394          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1395          */
1396         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1397         cred->gc_service = gss_auth->service;
1398         cred->gc_principal = acred->principal;
1399         kref_get(&gss_auth->kref);
1400         return &cred->gc_base;
1401
1402 out_err:
1403         dprintk("RPC:       %s failed with error %d\n", __func__, err);
1404         return ERR_PTR(err);
1405 }
1406
1407 static int
1408 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1409 {
1410         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1411         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1412         int err;
1413
1414         do {
1415                 err = gss_create_upcall(gss_auth, gss_cred);
1416         } while (err == -EAGAIN);
1417         return err;
1418 }
1419
1420 static char *
1421 gss_stringify_acceptor(struct rpc_cred *cred)
1422 {
1423         char *string = NULL;
1424         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1425         struct gss_cl_ctx *ctx;
1426         unsigned int len;
1427         struct xdr_netobj *acceptor;
1428
1429         rcu_read_lock();
1430         ctx = rcu_dereference(gss_cred->gc_ctx);
1431         if (!ctx)
1432                 goto out;
1433
1434         len = ctx->gc_acceptor.len;
1435         rcu_read_unlock();
1436
1437         /* no point if there's no string */
1438         if (!len)
1439                 return NULL;
1440 realloc:
1441         string = kmalloc(len + 1, GFP_KERNEL);
1442         if (!string)
1443                 return NULL;
1444
1445         rcu_read_lock();
1446         ctx = rcu_dereference(gss_cred->gc_ctx);
1447
1448         /* did the ctx disappear or was it replaced by one with no acceptor? */
1449         if (!ctx || !ctx->gc_acceptor.len) {
1450                 kfree(string);
1451                 string = NULL;
1452                 goto out;
1453         }
1454
1455         acceptor = &ctx->gc_acceptor;
1456
1457         /*
1458          * Did we find a new acceptor that's longer than the original? Allocate
1459          * a longer buffer and try again.
1460          */
1461         if (len < acceptor->len) {
1462                 len = acceptor->len;
1463                 rcu_read_unlock();
1464                 kfree(string);
1465                 goto realloc;
1466         }
1467
1468         memcpy(string, acceptor->data, acceptor->len);
1469         string[acceptor->len] = '\0';
1470 out:
1471         rcu_read_unlock();
1472         return string;
1473 }
1474
1475 /*
1476  * Returns -EACCES if GSS context is NULL or will expire within the
1477  * timeout (miliseconds)
1478  */
1479 static int
1480 gss_key_timeout(struct rpc_cred *rc)
1481 {
1482         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1483         struct gss_cl_ctx *ctx;
1484         unsigned long timeout = jiffies + (gss_key_expire_timeo * HZ);
1485         int ret = 0;
1486
1487         rcu_read_lock();
1488         ctx = rcu_dereference(gss_cred->gc_ctx);
1489         if (!ctx || time_after(timeout, ctx->gc_expiry))
1490                 ret = -EACCES;
1491         rcu_read_unlock();
1492
1493         return ret;
1494 }
1495
1496 static int
1497 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1498 {
1499         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1500         struct gss_cl_ctx *ctx;
1501         int ret;
1502
1503         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1504                 goto out;
1505         /* Don't match with creds that have expired. */
1506         rcu_read_lock();
1507         ctx = rcu_dereference(gss_cred->gc_ctx);
1508         if (!ctx || time_after(jiffies, ctx->gc_expiry)) {
1509                 rcu_read_unlock();
1510                 return 0;
1511         }
1512         rcu_read_unlock();
1513         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1514                 return 0;
1515 out:
1516         if (acred->principal != NULL) {
1517                 if (gss_cred->gc_principal == NULL)
1518                         return 0;
1519                 ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1520         } else {
1521                 if (gss_cred->gc_principal != NULL)
1522                         return 0;
1523                 ret = uid_eq(rc->cr_cred->fsuid, acred->cred->fsuid);
1524         }
1525         return ret;
1526 }
1527
1528 /*
1529 * Marshal credentials.
1530 * Maybe we should keep a cached credential for performance reasons.
1531 */
1532 static __be32 *
1533 gss_marshal(struct rpc_task *task, __be32 *p)
1534 {
1535         struct rpc_rqst *req = task->tk_rqstp;
1536         struct rpc_cred *cred = req->rq_cred;
1537         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1538                                                  gc_base);
1539         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1540         __be32          *cred_len;
1541         u32             maj_stat = 0;
1542         struct xdr_netobj mic;
1543         struct kvec     iov;
1544         struct xdr_buf  verf_buf;
1545
1546         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1547
1548         *p++ = htonl(RPC_AUTH_GSS);
1549         cred_len = p++;
1550
1551         spin_lock(&ctx->gc_seq_lock);
1552         req->rq_seqno = (ctx->gc_seq < MAXSEQ) ? ctx->gc_seq++ : MAXSEQ;
1553         spin_unlock(&ctx->gc_seq_lock);
1554         if (req->rq_seqno == MAXSEQ)
1555                 goto out_expired;
1556
1557         *p++ = htonl((u32) RPC_GSS_VERSION);
1558         *p++ = htonl((u32) ctx->gc_proc);
1559         *p++ = htonl((u32) req->rq_seqno);
1560         *p++ = htonl((u32) gss_cred->gc_service);
1561         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1562         *cred_len = htonl((p - (cred_len + 1)) << 2);
1563
1564         /* We compute the checksum for the verifier over the xdr-encoded bytes
1565          * starting with the xid and ending at the end of the credential: */
1566         iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
1567                                         req->rq_snd_buf.head[0].iov_base);
1568         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1569         xdr_buf_from_iov(&iov, &verf_buf);
1570
1571         /* set verifier flavor*/
1572         *p++ = htonl(RPC_AUTH_GSS);
1573
1574         mic.data = (u8 *)(p + 1);
1575         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1576         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1577                 goto out_expired;
1578         } else if (maj_stat != 0) {
1579                 pr_warn("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1580                 task->tk_status = -EIO;
1581                 goto out_put_ctx;
1582         }
1583         p = xdr_encode_opaque(p, NULL, mic.len);
1584         gss_put_ctx(ctx);
1585         return p;
1586 out_expired:
1587         clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1588         task->tk_status = -EKEYEXPIRED;
1589 out_put_ctx:
1590         gss_put_ctx(ctx);
1591         return NULL;
1592 }
1593
1594 static int gss_renew_cred(struct rpc_task *task)
1595 {
1596         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1597         struct gss_cred *gss_cred = container_of(oldcred,
1598                                                  struct gss_cred,
1599                                                  gc_base);
1600         struct rpc_auth *auth = oldcred->cr_auth;
1601         struct auth_cred acred = {
1602                 .cred = oldcred->cr_cred,
1603                 .principal = gss_cred->gc_principal,
1604         };
1605         struct rpc_cred *new;
1606
1607         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1608         if (IS_ERR(new))
1609                 return PTR_ERR(new);
1610         task->tk_rqstp->rq_cred = new;
1611         put_rpccred(oldcred);
1612         return 0;
1613 }
1614
1615 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1616 {
1617         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1618                 unsigned long now = jiffies;
1619                 unsigned long begin, expire;
1620                 struct gss_cred *gss_cred;
1621
1622                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1623                 begin = gss_cred->gc_upcall_timestamp;
1624                 expire = begin + gss_expired_cred_retry_delay * HZ;
1625
1626                 if (time_in_range_open(now, begin, expire))
1627                         return 1;
1628         }
1629         return 0;
1630 }
1631
1632 /*
1633 * Refresh credentials. XXX - finish
1634 */
1635 static int
1636 gss_refresh(struct rpc_task *task)
1637 {
1638         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1639         int ret = 0;
1640
1641         if (gss_cred_is_negative_entry(cred))
1642                 return -EKEYEXPIRED;
1643
1644         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1645                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1646                 ret = gss_renew_cred(task);
1647                 if (ret < 0)
1648                         goto out;
1649                 cred = task->tk_rqstp->rq_cred;
1650         }
1651
1652         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1653                 ret = gss_refresh_upcall(task);
1654 out:
1655         return ret;
1656 }
1657
1658 /* Dummy refresh routine: used only when destroying the context */
1659 static int
1660 gss_refresh_null(struct rpc_task *task)
1661 {
1662         return 0;
1663 }
1664
1665 static __be32 *
1666 gss_validate(struct rpc_task *task, __be32 *p)
1667 {
1668         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1669         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1670         __be32          *seq = NULL;
1671         struct kvec     iov;
1672         struct xdr_buf  verf_buf;
1673         struct xdr_netobj mic;
1674         u32             flav,len;
1675         u32             maj_stat;
1676         __be32          *ret = ERR_PTR(-EIO);
1677
1678         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1679
1680         flav = ntohl(*p++);
1681         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1682                 goto out_bad;
1683         if (flav != RPC_AUTH_GSS)
1684                 goto out_bad;
1685         seq = kmalloc(4, GFP_NOFS);
1686         if (!seq)
1687                 goto out_bad;
1688         *seq = htonl(task->tk_rqstp->rq_seqno);
1689         iov.iov_base = seq;
1690         iov.iov_len = 4;
1691         xdr_buf_from_iov(&iov, &verf_buf);
1692         mic.data = (u8 *)p;
1693         mic.len = len;
1694
1695         ret = ERR_PTR(-EACCES);
1696         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1697         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1698                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1699         if (maj_stat) {
1700                 dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1701                         task->tk_pid, __func__, maj_stat);
1702                 goto out_bad;
1703         }
1704         /* We leave it to unwrap to calculate au_rslack. For now we just
1705          * calculate the length of the verifier: */
1706         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1707         gss_put_ctx(ctx);
1708         dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1709                         task->tk_pid, __func__);
1710         kfree(seq);
1711         return p + XDR_QUADLEN(len);
1712 out_bad:
1713         gss_put_ctx(ctx);
1714         dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
1715                 PTR_ERR(ret));
1716         kfree(seq);
1717         return ret;
1718 }
1719
1720 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1721                                 __be32 *p, void *obj)
1722 {
1723         struct xdr_stream xdr;
1724
1725         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1726         encode(rqstp, &xdr, obj);
1727 }
1728
1729 static inline int
1730 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1731                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1732                    __be32 *p, void *obj)
1733 {
1734         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1735         struct xdr_buf  integ_buf;
1736         __be32          *integ_len = NULL;
1737         struct xdr_netobj mic;
1738         u32             offset;
1739         __be32          *q;
1740         struct kvec     *iov;
1741         u32             maj_stat = 0;
1742         int             status = -EIO;
1743
1744         integ_len = p++;
1745         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1746         *p++ = htonl(rqstp->rq_seqno);
1747
1748         gss_wrap_req_encode(encode, rqstp, p, obj);
1749
1750         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1751                                 offset, snd_buf->len - offset))
1752                 return status;
1753         *integ_len = htonl(integ_buf.len);
1754
1755         /* guess whether we're in the head or the tail: */
1756         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1757                 iov = snd_buf->tail;
1758         else
1759                 iov = snd_buf->head;
1760         p = iov->iov_base + iov->iov_len;
1761         mic.data = (u8 *)(p + 1);
1762
1763         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1764         status = -EIO; /* XXX? */
1765         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1766                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1767         else if (maj_stat)
1768                 return status;
1769         q = xdr_encode_opaque(p, NULL, mic.len);
1770
1771         offset = (u8 *)q - (u8 *)p;
1772         iov->iov_len += offset;
1773         snd_buf->len += offset;
1774         return 0;
1775 }
1776
1777 static void
1778 priv_release_snd_buf(struct rpc_rqst *rqstp)
1779 {
1780         int i;
1781
1782         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1783                 __free_page(rqstp->rq_enc_pages[i]);
1784         kfree(rqstp->rq_enc_pages);
1785         rqstp->rq_release_snd_buf = NULL;
1786 }
1787
1788 static int
1789 alloc_enc_pages(struct rpc_rqst *rqstp)
1790 {
1791         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1792         int first, last, i;
1793
1794         if (rqstp->rq_release_snd_buf)
1795                 rqstp->rq_release_snd_buf(rqstp);
1796
1797         if (snd_buf->page_len == 0) {
1798                 rqstp->rq_enc_pages_num = 0;
1799                 return 0;
1800         }
1801
1802         first = snd_buf->page_base >> PAGE_SHIFT;
1803         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_SHIFT;
1804         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1805         rqstp->rq_enc_pages
1806                 = kmalloc_array(rqstp->rq_enc_pages_num,
1807                                 sizeof(struct page *),
1808                                 GFP_NOFS);
1809         if (!rqstp->rq_enc_pages)
1810                 goto out;
1811         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1812                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1813                 if (rqstp->rq_enc_pages[i] == NULL)
1814                         goto out_free;
1815         }
1816         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1817         return 0;
1818 out_free:
1819         rqstp->rq_enc_pages_num = i;
1820         priv_release_snd_buf(rqstp);
1821 out:
1822         return -EAGAIN;
1823 }
1824
1825 static inline int
1826 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1827                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1828                   __be32 *p, void *obj)
1829 {
1830         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1831         u32             offset;
1832         u32             maj_stat;
1833         int             status;
1834         __be32          *opaque_len;
1835         struct page     **inpages;
1836         int             first;
1837         int             pad;
1838         struct kvec     *iov;
1839         char            *tmp;
1840
1841         opaque_len = p++;
1842         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1843         *p++ = htonl(rqstp->rq_seqno);
1844
1845         gss_wrap_req_encode(encode, rqstp, p, obj);
1846
1847         status = alloc_enc_pages(rqstp);
1848         if (status)
1849                 return status;
1850         first = snd_buf->page_base >> PAGE_SHIFT;
1851         inpages = snd_buf->pages + first;
1852         snd_buf->pages = rqstp->rq_enc_pages;
1853         snd_buf->page_base -= first << PAGE_SHIFT;
1854         /*
1855          * Give the tail its own page, in case we need extra space in the
1856          * head when wrapping:
1857          *
1858          * call_allocate() allocates twice the slack space required
1859          * by the authentication flavor to rq_callsize.
1860          * For GSS, slack is GSS_CRED_SLACK.
1861          */
1862         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1863                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1864                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1865                 snd_buf->tail[0].iov_base = tmp;
1866         }
1867         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1868         /* slack space should prevent this ever happening: */
1869         BUG_ON(snd_buf->len > snd_buf->buflen);
1870         status = -EIO;
1871         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1872          * done anyway, so it's safe to put the request on the wire: */
1873         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1874                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1875         else if (maj_stat)
1876                 return status;
1877
1878         *opaque_len = htonl(snd_buf->len - offset);
1879         /* guess whether we're in the head or the tail: */
1880         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1881                 iov = snd_buf->tail;
1882         else
1883                 iov = snd_buf->head;
1884         p = iov->iov_base + iov->iov_len;
1885         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1886         memset(p, 0, pad);
1887         iov->iov_len += pad;
1888         snd_buf->len += pad;
1889
1890         return 0;
1891 }
1892
1893 static int
1894 gss_wrap_req(struct rpc_task *task,
1895              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1896 {
1897         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1898         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1899                         gc_base);
1900         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1901         int             status = -EIO;
1902
1903         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1904         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1905                 /* The spec seems a little ambiguous here, but I think that not
1906                  * wrapping context destruction requests makes the most sense.
1907                  */
1908                 gss_wrap_req_encode(encode, rqstp, p, obj);
1909                 status = 0;
1910                 goto out;
1911         }
1912         switch (gss_cred->gc_service) {
1913         case RPC_GSS_SVC_NONE:
1914                 gss_wrap_req_encode(encode, rqstp, p, obj);
1915                 status = 0;
1916                 break;
1917         case RPC_GSS_SVC_INTEGRITY:
1918                 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1919                 break;
1920         case RPC_GSS_SVC_PRIVACY:
1921                 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1922                 break;
1923         }
1924 out:
1925         gss_put_ctx(ctx);
1926         dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1927         return status;
1928 }
1929
1930 static inline int
1931 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1932                 struct rpc_rqst *rqstp, __be32 **p)
1933 {
1934         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1935         struct xdr_buf integ_buf;
1936         struct xdr_netobj mic;
1937         u32 data_offset, mic_offset;
1938         u32 integ_len;
1939         u32 maj_stat;
1940         int status = -EIO;
1941
1942         integ_len = ntohl(*(*p)++);
1943         if (integ_len & 3)
1944                 return status;
1945         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1946         mic_offset = integ_len + data_offset;
1947         if (mic_offset > rcv_buf->len)
1948                 return status;
1949         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1950                 return status;
1951
1952         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1953                                 mic_offset - data_offset))
1954                 return status;
1955
1956         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1957                 return status;
1958
1959         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1960         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1961                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1962         if (maj_stat != GSS_S_COMPLETE)
1963                 return status;
1964         return 0;
1965 }
1966
1967 static inline int
1968 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1969                 struct rpc_rqst *rqstp, __be32 **p)
1970 {
1971         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1972         u32 offset;
1973         u32 opaque_len;
1974         u32 maj_stat;
1975         int status = -EIO;
1976
1977         opaque_len = ntohl(*(*p)++);
1978         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1979         if (offset + opaque_len > rcv_buf->len)
1980                 return status;
1981         /* remove padding: */
1982         rcv_buf->len = offset + opaque_len;
1983
1984         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1985         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1986                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1987         if (maj_stat != GSS_S_COMPLETE)
1988                 return status;
1989         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1990                 return status;
1991
1992         return 0;
1993 }
1994
1995 static int
1996 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1997                       __be32 *p, void *obj)
1998 {
1999         struct xdr_stream xdr;
2000
2001         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
2002         return decode(rqstp, &xdr, obj);
2003 }
2004
2005 static bool
2006 gss_seq_is_newer(u32 new, u32 old)
2007 {
2008         return (s32)(new - old) > 0;
2009 }
2010
2011 static bool
2012 gss_xmit_need_reencode(struct rpc_task *task)
2013 {
2014         struct rpc_rqst *req = task->tk_rqstp;
2015         struct rpc_cred *cred = req->rq_cred;
2016         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
2017         u32 win, seq_xmit;
2018         bool ret = true;
2019
2020         if (!ctx)
2021                 return true;
2022
2023         if (gss_seq_is_newer(req->rq_seqno, READ_ONCE(ctx->gc_seq)))
2024                 goto out;
2025
2026         seq_xmit = READ_ONCE(ctx->gc_seq_xmit);
2027         while (gss_seq_is_newer(req->rq_seqno, seq_xmit)) {
2028                 u32 tmp = seq_xmit;
2029
2030                 seq_xmit = cmpxchg(&ctx->gc_seq_xmit, tmp, req->rq_seqno);
2031                 if (seq_xmit == tmp) {
2032                         ret = false;
2033                         goto out;
2034                 }
2035         }
2036
2037         win = ctx->gc_win;
2038         if (win > 0)
2039                 ret = !gss_seq_is_newer(req->rq_seqno, seq_xmit - win);
2040 out:
2041         gss_put_ctx(ctx);
2042         return ret;
2043 }
2044
2045 static int
2046 gss_unwrap_resp(struct rpc_task *task,
2047                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
2048 {
2049         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
2050         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
2051                         gc_base);
2052         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
2053         __be32          *savedp = p;
2054         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
2055         int             savedlen = head->iov_len;
2056         int             status = -EIO;
2057
2058         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
2059                 goto out_decode;
2060         switch (gss_cred->gc_service) {
2061         case RPC_GSS_SVC_NONE:
2062                 break;
2063         case RPC_GSS_SVC_INTEGRITY:
2064                 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
2065                 if (status)
2066                         goto out;
2067                 break;
2068         case RPC_GSS_SVC_PRIVACY:
2069                 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
2070                 if (status)
2071                         goto out;
2072                 break;
2073         }
2074         /* take into account extra slack for integrity and privacy cases: */
2075         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
2076                                                 + (savedlen - head->iov_len);
2077 out_decode:
2078         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
2079 out:
2080         gss_put_ctx(ctx);
2081         dprintk("RPC: %5u %s returning %d\n",
2082                 task->tk_pid, __func__, status);
2083         return status;
2084 }
2085
2086 static const struct rpc_authops authgss_ops = {
2087         .owner          = THIS_MODULE,
2088         .au_flavor      = RPC_AUTH_GSS,
2089         .au_name        = "RPCSEC_GSS",
2090         .create         = gss_create,
2091         .destroy        = gss_destroy,
2092         .hash_cred      = gss_hash_cred,
2093         .lookup_cred    = gss_lookup_cred,
2094         .crcreate       = gss_create_cred,
2095         .list_pseudoflavors = gss_mech_list_pseudoflavors,
2096         .info2flavor    = gss_mech_info2flavor,
2097         .flavor2info    = gss_mech_flavor2info,
2098 };
2099
2100 static const struct rpc_credops gss_credops = {
2101         .cr_name                = "AUTH_GSS",
2102         .crdestroy              = gss_destroy_cred,
2103         .cr_init                = gss_cred_init,
2104         .crmatch                = gss_match,
2105         .crmarshal              = gss_marshal,
2106         .crrefresh              = gss_refresh,
2107         .crvalidate             = gss_validate,
2108         .crwrap_req             = gss_wrap_req,
2109         .crunwrap_resp          = gss_unwrap_resp,
2110         .crkey_timeout          = gss_key_timeout,
2111         .crstringify_acceptor   = gss_stringify_acceptor,
2112         .crneed_reencode        = gss_xmit_need_reencode,
2113 };
2114
2115 static const struct rpc_credops gss_nullops = {
2116         .cr_name                = "AUTH_GSS",
2117         .crdestroy              = gss_destroy_nullcred,
2118         .crmatch                = gss_match,
2119         .crmarshal              = gss_marshal,
2120         .crrefresh              = gss_refresh_null,
2121         .crvalidate             = gss_validate,
2122         .crwrap_req             = gss_wrap_req,
2123         .crunwrap_resp          = gss_unwrap_resp,
2124         .crstringify_acceptor   = gss_stringify_acceptor,
2125 };
2126
2127 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
2128         .upcall         = rpc_pipe_generic_upcall,
2129         .downcall       = gss_pipe_downcall,
2130         .destroy_msg    = gss_pipe_destroy_msg,
2131         .open_pipe      = gss_pipe_open_v0,
2132         .release_pipe   = gss_pipe_release,
2133 };
2134
2135 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
2136         .upcall         = rpc_pipe_generic_upcall,
2137         .downcall       = gss_pipe_downcall,
2138         .destroy_msg    = gss_pipe_destroy_msg,
2139         .open_pipe      = gss_pipe_open_v1,
2140         .release_pipe   = gss_pipe_release,
2141 };
2142
2143 static __net_init int rpcsec_gss_init_net(struct net *net)
2144 {
2145         return gss_svc_init_net(net);
2146 }
2147
2148 static __net_exit void rpcsec_gss_exit_net(struct net *net)
2149 {
2150         gss_svc_shutdown_net(net);
2151 }
2152
2153 static struct pernet_operations rpcsec_gss_net_ops = {
2154         .init = rpcsec_gss_init_net,
2155         .exit = rpcsec_gss_exit_net,
2156 };
2157
2158 /*
2159  * Initialize RPCSEC_GSS module
2160  */
2161 static int __init init_rpcsec_gss(void)
2162 {
2163         int err = 0;
2164
2165         err = rpcauth_register(&authgss_ops);
2166         if (err)
2167                 goto out;
2168         err = gss_svc_init();
2169         if (err)
2170                 goto out_unregister;
2171         err = register_pernet_subsys(&rpcsec_gss_net_ops);
2172         if (err)
2173                 goto out_svc_exit;
2174         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
2175         return 0;
2176 out_svc_exit:
2177         gss_svc_shutdown();
2178 out_unregister:
2179         rpcauth_unregister(&authgss_ops);
2180 out:
2181         return err;
2182 }
2183
2184 static void __exit exit_rpcsec_gss(void)
2185 {
2186         unregister_pernet_subsys(&rpcsec_gss_net_ops);
2187         gss_svc_shutdown();
2188         rpcauth_unregister(&authgss_ops);
2189         rcu_barrier(); /* Wait for completion of call_rcu()'s */
2190 }
2191
2192 MODULE_ALIAS("rpc-auth-6");
2193 MODULE_LICENSE("GPL");
2194 module_param_named(expired_cred_retry_delay,
2195                    gss_expired_cred_retry_delay,
2196                    uint, 0644);
2197 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
2198                 "the RPC engine retries an expired credential");
2199
2200 module_param_named(key_expire_timeo,
2201                    gss_key_expire_timeo,
2202                    uint, 0644);
2203 MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
2204                 "credential keys lifetime where the NFS layer cleans up "
2205                 "prior to key expiration");
2206
2207 module_init(init_rpcsec_gss)
2208 module_exit(exit_rpcsec_gss)