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 #include <trace/events/rpcgss.h>
  59
  60 static const struct rpc_authops authgss_ops;
  61
  62 static const struct rpc_credops gss_credops;
  63 static const struct rpc_credops gss_nullops;
  64
  65 #define GSS_RETRY_EXPIRED 5
  66 static unsigned int gss_expired_cred_retry_delay = GSS_RETRY_EXPIRED;
  67
  68 #define GSS_KEY_EXPIRE_TIMEO 240
  69 static unsigned int gss_key_expire_timeo = GSS_KEY_EXPIRE_TIMEO;
  70
  71 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  72 # define RPCDBG_FACILITY        RPCDBG_AUTH
  73 #endif
  74
  75 #define GSS_CRED_SLACK          (RPC_MAX_AUTH_SIZE * 2)
  76 /* length of a krb5 verifier (48), plus data added before arguments when
  77  * using integrity (two 4-byte integers): */
  78 #define GSS_VERF_SLACK          100
  79
  80 static DEFINE_HASHTABLE(gss_auth_hash_table, 4);
  81 static DEFINE_SPINLOCK(gss_auth_hash_lock);
  82
  83 struct gss_pipe {
  84         struct rpc_pipe_dir_object pdo;
  85         struct rpc_pipe *pipe;
  86         struct rpc_clnt *clnt;
  87         const char *name;
  88         struct kref kref;
  89 };
  90
  91 struct gss_auth {
  92         struct kref kref;
  93         struct hlist_node hash;
  94         struct rpc_auth rpc_auth;
  95         struct gss_api_mech *mech;
  96         enum rpc_gss_svc service;
  97         struct rpc_clnt *client;
  98         struct net *net;
  99         /*
 100          * There are two upcall pipes; dentry[1], named "gssd", is used
 101          * for the new text-based upcall; dentry[0] is named after the
 102          * mechanism (for example, "krb5") and exists for
 103          * backwards-compatibility with older gssd's.
 104          */
 105         struct gss_pipe *gss_pipe[2];
 106         const char *target_name;
 107 };
 108
 109 /* pipe_version >= 0 if and only if someone has a pipe open. */
 110 static DEFINE_SPINLOCK(pipe_version_lock);
 111 static struct rpc_wait_queue pipe_version_rpc_waitqueue;
 112 static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
 113 static void gss_put_auth(struct gss_auth *gss_auth);
 114
 115 static void gss_free_ctx(struct gss_cl_ctx *);
 116 static const struct rpc_pipe_ops gss_upcall_ops_v0;
 117 static const struct rpc_pipe_ops gss_upcall_ops_v1;
 118
 119 static inline struct gss_cl_ctx *
 120 gss_get_ctx(struct gss_cl_ctx *ctx)
 121 {
 122         refcount_inc(&ctx->count);
 123         return ctx;
 124 }
 125
 126 static inline void
 127 gss_put_ctx(struct gss_cl_ctx *ctx)
 128 {
 129         if (refcount_dec_and_test(&ctx->count))
 130                 gss_free_ctx(ctx);
 131 }
 132
 133 /* gss_cred_set_ctx:
 134  * called by gss_upcall_callback and gss_create_upcall in order
 135  * to set the gss context. The actual exchange of an old context
 136  * and a new one is protected by the pipe->lock.
 137  */
 138 static void
 139 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 140 {
 141         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 142
 143         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 144                 return;
 145         gss_get_ctx(ctx);
 146         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 147         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 148         smp_mb__before_atomic();
 149         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 150 }
 151
 152 static const void *
 153 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 154 {
 155         const void *q = (const void *)((const char *)p + len);
 156         if (unlikely(q > end || q < p))
 157                 return ERR_PTR(-EFAULT);
 158         memcpy(res, p, len);
 159         return q;
 160 }
 161
 162 static inline const void *
 163 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 164 {
 165         const void *q;
 166         unsigned int len;
 167
 168         p = simple_get_bytes(p, end, &len, sizeof(len));
 169         if (IS_ERR(p))
 170                 return p;
 171         q = (const void *)((const char *)p + len);
 172         if (unlikely(q > end || q < p))
 173                 return ERR_PTR(-EFAULT);
 174         dest->data = kmemdup(p, len, GFP_NOFS);
 175         if (unlikely(dest->data == NULL))
 176                 return ERR_PTR(-ENOMEM);
 177         dest->len = len;
 178         return q;
 179 }
 180
 181 static struct gss_cl_ctx *
 182 gss_cred_get_ctx(struct rpc_cred *cred)
 183 {
 184         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 185         struct gss_cl_ctx *ctx = NULL;
 186
 187         rcu_read_lock();
 188         ctx = rcu_dereference(gss_cred->gc_ctx);
 189         if (ctx)
 190                 gss_get_ctx(ctx);
 191         rcu_read_unlock();
 192         return ctx;
 193 }
 194
 195 static struct gss_cl_ctx *
 196 gss_alloc_context(void)
 197 {
 198         struct gss_cl_ctx *ctx;
 199
 200         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
 201         if (ctx != NULL) {
 202                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 203                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 204                 spin_lock_init(&ctx->gc_seq_lock);
 205                 refcount_set(&ctx->count,1);
 206         }
 207         return ctx;
 208 }
 209
 210 #define GSSD_MIN_TIMEOUT (60 * 60)
 211 static const void *
 212 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 213 {
 214         const void *q;
 215         unsigned int seclen;
 216         unsigned int timeout;
 217         unsigned long now = jiffies;
 218         u32 window_size;
 219         int ret;
 220
 221         /* First unsigned int gives the remaining lifetime in seconds of the
 222          * credential - e.g. the remaining TGT lifetime for Kerberos or
 223          * the -t value passed to GSSD.
 224          */
 225         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 226         if (IS_ERR(p))
 227                 goto err;
 228         if (timeout == 0)
 229                 timeout = GSSD_MIN_TIMEOUT;
 230         ctx->gc_expiry = now + ((unsigned long)timeout * HZ);
 231         /* Sequence number window. Determines the maximum number of
 232          * simultaneous requests
 233          */
 234         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 235         if (IS_ERR(p))
 236                 goto err;
 237         ctx->gc_win = window_size;
 238         /* gssd signals an error by passing ctx->gc_win = 0: */
 239         if (ctx->gc_win == 0) {
 240                 /*
 241                  * in which case, p points to an error code. Anything other
 242                  * than -EKEYEXPIRED gets converted to -EACCES.
 243                  */
 244                 p = simple_get_bytes(p, end, &ret, sizeof(ret));
 245                 if (!IS_ERR(p))
 246                         p = (ret == -EKEYEXPIRED) ? ERR_PTR(-EKEYEXPIRED) :
 247                                                     ERR_PTR(-EACCES);
 248                 goto err;
 249         }
 250         /* copy the opaque wire context */
 251         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 252         if (IS_ERR(p))
 253                 goto err;
 254         /* import the opaque security context */
 255         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 256         if (IS_ERR(p))
 257                 goto err;
 258         q = (const void *)((const char *)p + seclen);
 259         if (unlikely(q > end || q < p)) {
 260                 p = ERR_PTR(-EFAULT);
 261                 goto err;
 262         }
 263         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, NULL, GFP_NOFS);
 264         if (ret < 0) {
 265                 trace_rpcgss_import_ctx(ret);
 266                 p = ERR_PTR(ret);
 267                 goto err;
 268         }
 269
 270         /* is there any trailing data? */
 271         if (q == end) {
 272                 p = q;
 273                 goto done;
 274         }
 275
 276         /* pull in acceptor name (if there is one) */
 277         p = simple_get_netobj(q, end, &ctx->gc_acceptor);
 278         if (IS_ERR(p))
 279                 goto err;
 280 done:
 281         trace_rpcgss_context(ctx->gc_expiry, now, timeout,
 282                              ctx->gc_acceptor.len, ctx->gc_acceptor.data);
 283 err:
 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                 return pos;
 358         }
 359         return NULL;
 360 }
 361
 362 /* Try to add an upcall to the pipefs queue.
 363  * If an upcall owned by our uid already exists, then we return a reference
 364  * to that upcall instead of adding the new upcall.
 365  */
 366 static inline struct gss_upcall_msg *
 367 gss_add_msg(struct gss_upcall_msg *gss_msg)
 368 {
 369         struct rpc_pipe *pipe = gss_msg->pipe;
 370         struct gss_upcall_msg *old;
 371
 372         spin_lock(&pipe->lock);
 373         old = __gss_find_upcall(pipe, gss_msg->uid, gss_msg->auth);
 374         if (old == NULL) {
 375                 refcount_inc(&gss_msg->count);
 376                 list_add(&gss_msg->list, &pipe->in_downcall);
 377         } else
 378                 gss_msg = old;
 379         spin_unlock(&pipe->lock);
 380         return gss_msg;
 381 }
 382
 383 static void
 384 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 385 {
 386         list_del_init(&gss_msg->list);
 387         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 388         wake_up_all(&gss_msg->waitqueue);
 389         refcount_dec(&gss_msg->count);
 390 }
 391
 392 static void
 393 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 394 {
 395         struct rpc_pipe *pipe = gss_msg->pipe;
 396
 397         if (list_empty(&gss_msg->list))
 398                 return;
 399         spin_lock(&pipe->lock);
 400         if (!list_empty(&gss_msg->list))
 401                 __gss_unhash_msg(gss_msg);
 402         spin_unlock(&pipe->lock);
 403 }
 404
 405 static void
 406 gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
 407 {
 408         switch (gss_msg->msg.errno) {
 409         case 0:
 410                 if (gss_msg->ctx == NULL)
 411                         break;
 412                 clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 413                 gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
 414                 break;
 415         case -EKEYEXPIRED:
 416                 set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 417         }
 418         gss_cred->gc_upcall_timestamp = jiffies;
 419         gss_cred->gc_upcall = NULL;
 420         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 421 }
 422
 423 static void
 424 gss_upcall_callback(struct rpc_task *task)
 425 {
 426         struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
 427                         struct gss_cred, gc_base);
 428         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 429         struct rpc_pipe *pipe = gss_msg->pipe;
 430
 431         spin_lock(&pipe->lock);
 432         gss_handle_downcall_result(gss_cred, gss_msg);
 433         spin_unlock(&pipe->lock);
 434         task->tk_status = gss_msg->msg.errno;
 435         gss_release_msg(gss_msg);
 436 }
 437
 438 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
 439 {
 440         uid_t uid = from_kuid(&init_user_ns, gss_msg->uid);
 441         memcpy(gss_msg->databuf, &uid, sizeof(uid));
 442         gss_msg->msg.data = gss_msg->databuf;
 443         gss_msg->msg.len = sizeof(uid);
 444
 445         BUILD_BUG_ON(sizeof(uid) > sizeof(gss_msg->databuf));
 446 }
 447
 448 static int gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
 449                                 const char *service_name,
 450                                 const char *target_name)
 451 {
 452         struct gss_api_mech *mech = gss_msg->auth->mech;
 453         char *p = gss_msg->databuf;
 454         size_t buflen = sizeof(gss_msg->databuf);
 455         int len;
 456
 457         len = scnprintf(p, buflen, "mech=%s uid=%d", mech->gm_name,
 458                         from_kuid(&init_user_ns, gss_msg->uid));
 459         buflen -= len;
 460         p += len;
 461         gss_msg->msg.len = len;
 462
 463         /*
 464          * target= is a full service principal that names the remote
 465          * identity that we are authenticating to.
 466          */
 467         if (target_name) {
 468                 len = scnprintf(p, buflen, " target=%s", target_name);
 469                 buflen -= len;
 470                 p += len;
 471                 gss_msg->msg.len += len;
 472         }
 473
 474         /*
 475          * gssd uses service= and srchost= to select a matching key from
 476          * the system's keytab to use as the source principal.
 477          *
 478          * service= is the service name part of the source principal,
 479          * or "*" (meaning choose any).
 480          *
 481          * srchost= is the hostname part of the source principal. When
 482          * not provided, gssd uses the local hostname.
 483          */
 484         if (service_name) {
 485                 char *c = strchr(service_name, '@');
 486
 487                 if (!c)
 488                         len = scnprintf(p, buflen, " service=%s",
 489                                         service_name);
 490                 else
 491                         len = scnprintf(p, buflen,
 492                                         " service=%.*s srchost=%s",
 493                                         (int)(c - service_name),
 494                                         service_name, c + 1);
 495                 buflen -= len;
 496                 p += len;
 497                 gss_msg->msg.len += len;
 498         }
 499
 500         if (mech->gm_upcall_enctypes) {
 501                 len = scnprintf(p, buflen, " enctypes=%s",
 502                                 mech->gm_upcall_enctypes);
 503                 buflen -= len;
 504                 p += len;
 505                 gss_msg->msg.len += len;
 506         }
 507         trace_rpcgss_upcall_msg(gss_msg->databuf);
 508         len = scnprintf(p, buflen, "\n");
 509         if (len == 0)
 510                 goto out_overflow;
 511         gss_msg->msg.len += len;
 512         gss_msg->msg.data = gss_msg->databuf;
 513         return 0;
 514 out_overflow:
 515         WARN_ON_ONCE(1);
 516         return -ENOMEM;
 517 }
 518
 519 static struct gss_upcall_msg *
 520 gss_alloc_msg(struct gss_auth *gss_auth,
 521                 kuid_t uid, const char *service_name)
 522 {
 523         struct gss_upcall_msg *gss_msg;
 524         int vers;
 525         int err = -ENOMEM;
 526
 527         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 528         if (gss_msg == NULL)
 529                 goto err;
 530         vers = get_pipe_version(gss_auth->net);
 531         err = vers;
 532         if (err < 0)
 533                 goto err_free_msg;
 534         gss_msg->pipe = gss_auth->gss_pipe[vers]->pipe;
 535         INIT_LIST_HEAD(&gss_msg->list);
 536         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 537         init_waitqueue_head(&gss_msg->waitqueue);
 538         refcount_set(&gss_msg->count, 1);
 539         gss_msg->uid = uid;
 540         gss_msg->auth = gss_auth;
 541         switch (vers) {
 542         case 0:
 543                 gss_encode_v0_msg(gss_msg);
 544                 break;
 545         default:
 546                 err = gss_encode_v1_msg(gss_msg, service_name, gss_auth->target_name);
 547                 if (err)
 548                         goto err_put_pipe_version;
 549         }
 550         kref_get(&gss_auth->kref);
 551         return gss_msg;
 552 err_put_pipe_version:
 553         put_pipe_version(gss_auth->net);
 554 err_free_msg:
 555         kfree(gss_msg);
 556 err:
 557         return ERR_PTR(err);
 558 }
 559
 560 static struct gss_upcall_msg *
 561 gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred)
 562 {
 563         struct gss_cred *gss_cred = container_of(cred,
 564                         struct gss_cred, gc_base);
 565         struct gss_upcall_msg *gss_new, *gss_msg;
 566         kuid_t uid = cred->cr_cred->fsuid;
 567
 568         gss_new = gss_alloc_msg(gss_auth, uid, gss_cred->gc_principal);
 569         if (IS_ERR(gss_new))
 570                 return gss_new;
 571         gss_msg = gss_add_msg(gss_new);
 572         if (gss_msg == gss_new) {
 573                 int res;
 574                 refcount_inc(&gss_msg->count);
 575                 res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
 576                 if (res) {
 577                         gss_unhash_msg(gss_new);
 578                         refcount_dec(&gss_msg->count);
 579                         gss_release_msg(gss_new);
 580                         gss_msg = ERR_PTR(res);
 581                 }
 582         } else
 583                 gss_release_msg(gss_new);
 584         return gss_msg;
 585 }
 586
 587 static void warn_gssd(void)
 588 {
 589         dprintk("AUTH_GSS upcall failed. Please check user daemon is running.\n");
 590 }
 591
 592 static inline int
 593 gss_refresh_upcall(struct rpc_task *task)
 594 {
 595         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 596         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 597                         struct gss_auth, rpc_auth);
 598         struct gss_cred *gss_cred = container_of(cred,
 599                         struct gss_cred, gc_base);
 600         struct gss_upcall_msg *gss_msg;
 601         struct rpc_pipe *pipe;
 602         int err = 0;
 603
 604         gss_msg = gss_setup_upcall(gss_auth, cred);
 605         if (PTR_ERR(gss_msg) == -EAGAIN) {
 606                 /* XXX: warning on the first, under the assumption we
 607                  * shouldn't normally hit this case on a refresh. */
 608                 warn_gssd();
 609                 task->tk_timeout = 15*HZ;
 610                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
 611                 err = -EAGAIN;
 612                 goto out;
 613         }
 614         if (IS_ERR(gss_msg)) {
 615                 err = PTR_ERR(gss_msg);
 616                 goto out;
 617         }
 618         pipe = gss_msg->pipe;
 619         spin_lock(&pipe->lock);
 620         if (gss_cred->gc_upcall != NULL)
 621                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 622         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 623                 task->tk_timeout = 0;
 624                 gss_cred->gc_upcall = gss_msg;
 625                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 626                 refcount_inc(&gss_msg->count);
 627                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 628         } else {
 629                 gss_handle_downcall_result(gss_cred, gss_msg);
 630                 err = gss_msg->msg.errno;
 631         }
 632         spin_unlock(&pipe->lock);
 633         gss_release_msg(gss_msg);
 634 out:
 635         trace_rpcgss_upcall_result(from_kuid(&init_user_ns,
 636                                              cred->cr_cred->fsuid), err);
 637         return err;
 638 }
 639
 640 static inline int
 641 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 642 {
 643         struct net *net = gss_auth->net;
 644         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 645         struct rpc_pipe *pipe;
 646         struct rpc_cred *cred = &gss_cred->gc_base;
 647         struct gss_upcall_msg *gss_msg;
 648         DEFINE_WAIT(wait);
 649         int err;
 650
 651 retry:
 652         err = 0;
 653         /* if gssd is down, just skip upcalling altogether */
 654         if (!gssd_running(net)) {
 655                 warn_gssd();
 656                 err = -EACCES;
 657                 goto out;
 658         }
 659         gss_msg = gss_setup_upcall(gss_auth, cred);
 660         if (PTR_ERR(gss_msg) == -EAGAIN) {
 661                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
 662                                 sn->pipe_version >= 0, 15 * HZ);
 663                 if (sn->pipe_version < 0) {
 664                         warn_gssd();
 665                         err = -EACCES;
 666                 }
 667                 if (err < 0)
 668                         goto out;
 669                 goto retry;
 670         }
 671         if (IS_ERR(gss_msg)) {
 672                 err = PTR_ERR(gss_msg);
 673                 goto out;
 674         }
 675         pipe = gss_msg->pipe;
 676         for (;;) {
 677                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
 678                 spin_lock(&pipe->lock);
 679                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 680                         break;
 681                 }
 682                 spin_unlock(&pipe->lock);
 683                 if (fatal_signal_pending(current)) {
 684                         err = -ERESTARTSYS;
 685                         goto out_intr;
 686                 }
 687                 schedule();
 688         }
 689         if (gss_msg->ctx)
 690                 gss_cred_set_ctx(cred, gss_msg->ctx);
 691         else
 692                 err = gss_msg->msg.errno;
 693         spin_unlock(&pipe->lock);
 694 out_intr:
 695         finish_wait(&gss_msg->waitqueue, &wait);
 696         gss_release_msg(gss_msg);
 697 out:
 698         trace_rpcgss_upcall_result(from_kuid(&init_user_ns,
 699                                              cred->cr_cred->fsuid), err);
 700         return err;
 701 }
 702
 703 #define MSG_BUF_MAXSIZE 1024
 704
 705 static ssize_t
 706 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 707 {
 708         const void *p, *end;
 709         void *buf;
 710         struct gss_upcall_msg *gss_msg;
 711         struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
 712         struct gss_cl_ctx *ctx;
 713         uid_t id;
 714         kuid_t uid;
 715         ssize_t err = -EFBIG;
 716
 717         if (mlen > MSG_BUF_MAXSIZE)
 718                 goto out;
 719         err = -ENOMEM;
 720         buf = kmalloc(mlen, GFP_NOFS);
 721         if (!buf)
 722                 goto out;
 723
 724         err = -EFAULT;
 725         if (copy_from_user(buf, src, mlen))
 726                 goto err;
 727
 728         end = (const void *)((char *)buf + mlen);
 729         p = simple_get_bytes(buf, end, &id, sizeof(id));
 730         if (IS_ERR(p)) {
 731                 err = PTR_ERR(p);
 732                 goto err;
 733         }
 734
 735         uid = make_kuid(&init_user_ns, id);
 736         if (!uid_valid(uid)) {
 737                 err = -EINVAL;
 738                 goto err;
 739         }
 740
 741         err = -ENOMEM;
 742         ctx = gss_alloc_context();
 743         if (ctx == NULL)
 744                 goto err;
 745
 746         err = -ENOENT;
 747         /* Find a matching upcall */
 748         spin_lock(&pipe->lock);
 749         gss_msg = __gss_find_upcall(pipe, uid, NULL);
 750         if (gss_msg == NULL) {
 751                 spin_unlock(&pipe->lock);
 752                 goto err_put_ctx;
 753         }
 754         list_del_init(&gss_msg->list);
 755         spin_unlock(&pipe->lock);
 756
 757         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 758         if (IS_ERR(p)) {
 759                 err = PTR_ERR(p);
 760                 switch (err) {
 761                 case -EACCES:
 762                 case -EKEYEXPIRED:
 763                         gss_msg->msg.errno = err;
 764                         err = mlen;
 765                         break;
 766                 case -EFAULT:
 767                 case -ENOMEM:
 768                 case -EINVAL:
 769                 case -ENOSYS:
 770                         gss_msg->msg.errno = -EAGAIN;
 771                         break;
 772                 default:
 773                         printk(KERN_CRIT "%s: bad return from "
 774                                 "gss_fill_context: %zd\n", __func__, err);
 775                         gss_msg->msg.errno = -EIO;
 776                 }
 777                 goto err_release_msg;
 778         }
 779         gss_msg->ctx = gss_get_ctx(ctx);
 780         err = mlen;
 781
 782 err_release_msg:
 783         spin_lock(&pipe->lock);
 784         __gss_unhash_msg(gss_msg);
 785         spin_unlock(&pipe->lock);
 786         gss_release_msg(gss_msg);
 787 err_put_ctx:
 788         gss_put_ctx(ctx);
 789 err:
 790         kfree(buf);
 791 out:
 792         return err;
 793 }
 794
 795 static int gss_pipe_open(struct inode *inode, int new_version)
 796 {
 797         struct net *net = inode->i_sb->s_fs_info;
 798         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 799         int ret = 0;
 800
 801         spin_lock(&pipe_version_lock);
 802         if (sn->pipe_version < 0) {
 803                 /* First open of any gss pipe determines the version: */
 804                 sn->pipe_version = new_version;
 805                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 806                 wake_up(&pipe_version_waitqueue);
 807         } else if (sn->pipe_version != new_version) {
 808                 /* Trying to open a pipe of a different version */
 809                 ret = -EBUSY;
 810                 goto out;
 811         }
 812         atomic_inc(&sn->pipe_users);
 813 out:
 814         spin_unlock(&pipe_version_lock);
 815         return ret;
 816
 817 }
 818
 819 static int gss_pipe_open_v0(struct inode *inode)
 820 {
 821         return gss_pipe_open(inode, 0);
 822 }
 823
 824 static int gss_pipe_open_v1(struct inode *inode)
 825 {
 826         return gss_pipe_open(inode, 1);
 827 }
 828
 829 static void
 830 gss_pipe_release(struct inode *inode)
 831 {
 832         struct net *net = inode->i_sb->s_fs_info;
 833         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 834         struct gss_upcall_msg *gss_msg;
 835
 836 restart:
 837         spin_lock(&pipe->lock);
 838         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
 839
 840                 if (!list_empty(&gss_msg->msg.list))
 841                         continue;
 842                 gss_msg->msg.errno = -EPIPE;
 843                 refcount_inc(&gss_msg->count);
 844                 __gss_unhash_msg(gss_msg);
 845                 spin_unlock(&pipe->lock);
 846                 gss_release_msg(gss_msg);
 847                 goto restart;
 848         }
 849         spin_unlock(&pipe->lock);
 850
 851         put_pipe_version(net);
 852 }
 853
 854 static void
 855 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 856 {
 857         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 858
 859         if (msg->errno < 0) {
 860                 refcount_inc(&gss_msg->count);
 861                 gss_unhash_msg(gss_msg);
 862                 if (msg->errno == -ETIMEDOUT)
 863                         warn_gssd();
 864                 gss_release_msg(gss_msg);
 865         }
 866         gss_release_msg(gss_msg);
 867 }
 868
 869 static void gss_pipe_dentry_destroy(struct dentry *dir,
 870                 struct rpc_pipe_dir_object *pdo)
 871 {
 872         struct gss_pipe *gss_pipe = pdo->pdo_data;
 873         struct rpc_pipe *pipe = gss_pipe->pipe;
 874
 875         if (pipe->dentry != NULL) {
 876                 rpc_unlink(pipe->dentry);
 877                 pipe->dentry = NULL;
 878         }
 879 }
 880
 881 static int gss_pipe_dentry_create(struct dentry *dir,
 882                 struct rpc_pipe_dir_object *pdo)
 883 {
 884         struct gss_pipe *p = pdo->pdo_data;
 885         struct dentry *dentry;
 886
 887         dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
 888         if (IS_ERR(dentry))
 889                 return PTR_ERR(dentry);
 890         p->pipe->dentry = dentry;
 891         return 0;
 892 }
 893
 894 static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
 895         .create = gss_pipe_dentry_create,
 896         .destroy = gss_pipe_dentry_destroy,
 897 };
 898
 899 static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
 900                 const char *name,
 901                 const struct rpc_pipe_ops *upcall_ops)
 902 {
 903         struct gss_pipe *p;
 904         int err = -ENOMEM;
 905
 906         p = kmalloc(sizeof(*p), GFP_KERNEL);
 907         if (p == NULL)
 908                 goto err;
 909         p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 910         if (IS_ERR(p->pipe)) {
 911                 err = PTR_ERR(p->pipe);
 912                 goto err_free_gss_pipe;
 913         }
 914         p->name = name;
 915         p->clnt = clnt;
 916         kref_init(&p->kref);
 917         rpc_init_pipe_dir_object(&p->pdo,
 918                         &gss_pipe_dir_object_ops,
 919                         p);
 920         return p;
 921 err_free_gss_pipe:
 922         kfree(p);
 923 err:
 924         return ERR_PTR(err);
 925 }
 926
 927 struct gss_alloc_pdo {
 928         struct rpc_clnt *clnt;
 929         const char *name;
 930         const struct rpc_pipe_ops *upcall_ops;
 931 };
 932
 933 static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
 934 {
 935         struct gss_pipe *gss_pipe;
 936         struct gss_alloc_pdo *args = data;
 937
 938         if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
 939                 return 0;
 940         gss_pipe = container_of(pdo, struct gss_pipe, pdo);
 941         if (strcmp(gss_pipe->name, args->name) != 0)
 942                 return 0;
 943         if (!kref_get_unless_zero(&gss_pipe->kref))
 944                 return 0;
 945         return 1;
 946 }
 947
 948 static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
 949 {
 950         struct gss_pipe *gss_pipe;
 951         struct gss_alloc_pdo *args = data;
 952
 953         gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
 954         if (!IS_ERR(gss_pipe))
 955                 return &gss_pipe->pdo;
 956         return NULL;
 957 }
 958
 959 static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
 960                 const char *name,
 961                 const struct rpc_pipe_ops *upcall_ops)
 962 {
 963         struct net *net = rpc_net_ns(clnt);
 964         struct rpc_pipe_dir_object *pdo;
 965         struct gss_alloc_pdo args = {
 966                 .clnt = clnt,
 967                 .name = name,
 968                 .upcall_ops = upcall_ops,
 969         };
 970
 971         pdo = rpc_find_or_alloc_pipe_dir_object(net,
 972                         &clnt->cl_pipedir_objects,
 973                         gss_pipe_match_pdo,
 974                         gss_pipe_alloc_pdo,
 975                         &args);
 976         if (pdo != NULL)
 977                 return container_of(pdo, struct gss_pipe, pdo);
 978         return ERR_PTR(-ENOMEM);
 979 }
 980
 981 static void __gss_pipe_free(struct gss_pipe *p)
 982 {
 983         struct rpc_clnt *clnt = p->clnt;
 984         struct net *net = rpc_net_ns(clnt);
 985
 986         rpc_remove_pipe_dir_object(net,
 987                         &clnt->cl_pipedir_objects,
 988                         &p->pdo);
 989         rpc_destroy_pipe_data(p->pipe);
 990         kfree(p);
 991 }
 992
 993 static void __gss_pipe_release(struct kref *kref)
 994 {
 995         struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
 996
 997         __gss_pipe_free(p);
 998 }
 999
1000 static void gss_pipe_free(struct gss_pipe *p)
1001 {
1002         if (p != NULL)
1003                 kref_put(&p->kref, __gss_pipe_release);
1004 }
1005
1006 /*
1007  * NOTE: we have the opportunity to use different
1008  * parameters based on the input flavor (which must be a pseudoflavor)
1009  */
1010 static struct gss_auth *
1011 gss_create_new(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1012 {
1013         rpc_authflavor_t flavor = args->pseudoflavor;
1014         struct gss_auth *gss_auth;
1015         struct gss_pipe *gss_pipe;
1016         struct rpc_auth * auth;
1017         int err = -ENOMEM; /* XXX? */
1018
1019         if (!try_module_get(THIS_MODULE))
1020                 return ERR_PTR(err);
1021         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
1022                 goto out_dec;
1023         INIT_HLIST_NODE(&gss_auth->hash);
1024         gss_auth->target_name = NULL;
1025         if (args->target_name) {
1026                 gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
1027                 if (gss_auth->target_name == NULL)
1028                         goto err_free;
1029         }
1030         gss_auth->client = clnt;
1031         gss_auth->net = get_net(rpc_net_ns(clnt));
1032         err = -EINVAL;
1033         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
1034         if (!gss_auth->mech)
1035                 goto err_put_net;
1036         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
1037         if (gss_auth->service == 0)
1038                 goto err_put_mech;
1039         if (!gssd_running(gss_auth->net))
1040                 goto err_put_mech;
1041         auth = &gss_auth->rpc_auth;
1042         auth->au_cslack = GSS_CRED_SLACK >> 2;
1043         auth->au_rslack = GSS_VERF_SLACK >> 2;
1044         auth->au_flags = 0;
1045         auth->au_ops = &authgss_ops;
1046         auth->au_flavor = flavor;
1047         if (gss_pseudoflavor_to_datatouch(gss_auth->mech, flavor))
1048                 auth->au_flags |= RPCAUTH_AUTH_DATATOUCH;
1049         refcount_set(&auth->au_count, 1);
1050         kref_init(&gss_auth->kref);
1051
1052         err = rpcauth_init_credcache(auth);
1053         if (err)
1054                 goto err_put_mech;
1055         /*
1056          * Note: if we created the old pipe first, then someone who
1057          * examined the directory at the right moment might conclude
1058          * that we supported only the old pipe.  So we instead create
1059          * the new pipe first.
1060          */
1061         gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
1062         if (IS_ERR(gss_pipe)) {
1063                 err = PTR_ERR(gss_pipe);
1064                 goto err_destroy_credcache;
1065         }
1066         gss_auth->gss_pipe[1] = gss_pipe;
1067
1068         gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
1069                         &gss_upcall_ops_v0);
1070         if (IS_ERR(gss_pipe)) {
1071                 err = PTR_ERR(gss_pipe);
1072                 goto err_destroy_pipe_1;
1073         }
1074         gss_auth->gss_pipe[0] = gss_pipe;
1075
1076         return gss_auth;
1077 err_destroy_pipe_1:
1078         gss_pipe_free(gss_auth->gss_pipe[1]);
1079 err_destroy_credcache:
1080         rpcauth_destroy_credcache(auth);
1081 err_put_mech:
1082         gss_mech_put(gss_auth->mech);
1083 err_put_net:
1084         put_net(gss_auth->net);
1085 err_free:
1086         kfree(gss_auth->target_name);
1087         kfree(gss_auth);
1088 out_dec:
1089         module_put(THIS_MODULE);
1090         trace_rpcgss_createauth(flavor, err);
1091         return ERR_PTR(err);
1092 }
1093
1094 static void
1095 gss_free(struct gss_auth *gss_auth)
1096 {
1097         gss_pipe_free(gss_auth->gss_pipe[0]);
1098         gss_pipe_free(gss_auth->gss_pipe[1]);
1099         gss_mech_put(gss_auth->mech);
1100         put_net(gss_auth->net);
1101         kfree(gss_auth->target_name);
1102
1103         kfree(gss_auth);
1104         module_put(THIS_MODULE);
1105 }
1106
1107 static void
1108 gss_free_callback(struct kref *kref)
1109 {
1110         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1111
1112         gss_free(gss_auth);
1113 }
1114
1115 static void
1116 gss_put_auth(struct gss_auth *gss_auth)
1117 {
1118         kref_put(&gss_auth->kref, gss_free_callback);
1119 }
1120
1121 static void
1122 gss_destroy(struct rpc_auth *auth)
1123 {
1124         struct gss_auth *gss_auth = container_of(auth,
1125                         struct gss_auth, rpc_auth);
1126
1127         if (hash_hashed(&gss_auth->hash)) {
1128                 spin_lock(&gss_auth_hash_lock);
1129                 hash_del(&gss_auth->hash);
1130                 spin_unlock(&gss_auth_hash_lock);
1131         }
1132
1133         gss_pipe_free(gss_auth->gss_pipe[0]);
1134         gss_auth->gss_pipe[0] = NULL;
1135         gss_pipe_free(gss_auth->gss_pipe[1]);
1136         gss_auth->gss_pipe[1] = NULL;
1137         rpcauth_destroy_credcache(auth);
1138
1139         gss_put_auth(gss_auth);
1140 }
1141
1142 /*
1143  * Auths may be shared between rpc clients that were cloned from a
1144  * common client with the same xprt, if they also share the flavor and
1145  * target_name.
1146  *
1147  * The auth is looked up from the oldest parent sharing the same
1148  * cl_xprt, and the auth itself references only that common parent
1149  * (which is guaranteed to last as long as any of its descendants).
1150  */
1151 static struct gss_auth *
1152 gss_auth_find_or_add_hashed(const struct rpc_auth_create_args *args,
1153                 struct rpc_clnt *clnt,
1154                 struct gss_auth *new)
1155 {
1156         struct gss_auth *gss_auth;
1157         unsigned long hashval = (unsigned long)clnt;
1158
1159         spin_lock(&gss_auth_hash_lock);
1160         hash_for_each_possible(gss_auth_hash_table,
1161                         gss_auth,
1162                         hash,
1163                         hashval) {
1164                 if (gss_auth->client != clnt)
1165                         continue;
1166                 if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1167                         continue;
1168                 if (gss_auth->target_name != args->target_name) {
1169                         if (gss_auth->target_name == NULL)
1170                                 continue;
1171                         if (args->target_name == NULL)
1172                                 continue;
1173                         if (strcmp(gss_auth->target_name, args->target_name))
1174                                 continue;
1175                 }
1176                 if (!refcount_inc_not_zero(&gss_auth->rpc_auth.au_count))
1177                         continue;
1178                 goto out;
1179         }
1180         if (new)
1181                 hash_add(gss_auth_hash_table, &new->hash, hashval);
1182         gss_auth = new;
1183 out:
1184         spin_unlock(&gss_auth_hash_lock);
1185         return gss_auth;
1186 }
1187
1188 static struct gss_auth *
1189 gss_create_hashed(const struct rpc_auth_create_args *args,
1190                   struct rpc_clnt *clnt)
1191 {
1192         struct gss_auth *gss_auth;
1193         struct gss_auth *new;
1194
1195         gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1196         if (gss_auth != NULL)
1197                 goto out;
1198         new = gss_create_new(args, clnt);
1199         if (IS_ERR(new))
1200                 return new;
1201         gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1202         if (gss_auth != new)
1203                 gss_destroy(&new->rpc_auth);
1204 out:
1205         return gss_auth;
1206 }
1207
1208 static struct rpc_auth *
1209 gss_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1210 {
1211         struct gss_auth *gss_auth;
1212         struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
1213
1214         while (clnt != clnt->cl_parent) {
1215                 struct rpc_clnt *parent = clnt->cl_parent;
1216                 /* Find the original parent for this transport */
1217                 if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
1218                         break;
1219                 clnt = parent;
1220         }
1221
1222         gss_auth = gss_create_hashed(args, clnt);
1223         if (IS_ERR(gss_auth))
1224                 return ERR_CAST(gss_auth);
1225         return &gss_auth->rpc_auth;
1226 }
1227
1228 static struct gss_cred *
1229 gss_dup_cred(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
1230 {
1231         struct gss_cred *new;
1232
1233         /* Make a copy of the cred so that we can reference count it */
1234         new = kzalloc(sizeof(*gss_cred), GFP_NOIO);
1235         if (new) {
1236                 struct auth_cred acred = {
1237                         .cred = gss_cred->gc_base.cr_cred,
1238                 };
1239                 struct gss_cl_ctx *ctx =
1240                         rcu_dereference_protected(gss_cred->gc_ctx, 1);
1241
1242                 rpcauth_init_cred(&new->gc_base, &acred,
1243                                 &gss_auth->rpc_auth,
1244                                 &gss_nullops);
1245                 new->gc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
1246                 new->gc_service = gss_cred->gc_service;
1247                 new->gc_principal = gss_cred->gc_principal;
1248                 kref_get(&gss_auth->kref);
1249                 rcu_assign_pointer(new->gc_ctx, ctx);
1250                 gss_get_ctx(ctx);
1251         }
1252         return new;
1253 }
1254
1255 /*
1256  * gss_send_destroy_context will cause the RPCSEC_GSS to send a NULL RPC call
1257  * to the server with the GSS control procedure field set to
1258  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1259  * all RPCSEC_GSS state associated with that context.
1260  */
1261 static void
1262 gss_send_destroy_context(struct rpc_cred *cred)
1263 {
1264         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1265         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1266         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1267         struct gss_cred *new;
1268         struct rpc_task *task;
1269
1270         new = gss_dup_cred(gss_auth, gss_cred);
1271         if (new) {
1272                 ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1273
1274                 task = rpc_call_null(gss_auth->client, &new->gc_base,
1275                                 RPC_TASK_ASYNC|RPC_TASK_SOFT);
1276                 if (!IS_ERR(task))
1277                         rpc_put_task(task);
1278
1279                 put_rpccred(&new->gc_base);
1280         }
1281 }
1282
1283 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1284  * to create a new cred or context, so they check that things have been
1285  * allocated before freeing them. */
1286 static void
1287 gss_do_free_ctx(struct gss_cl_ctx *ctx)
1288 {
1289         gss_delete_sec_context(&ctx->gc_gss_ctx);
1290         kfree(ctx->gc_wire_ctx.data);
1291         kfree(ctx->gc_acceptor.data);
1292         kfree(ctx);
1293 }
1294
1295 static void
1296 gss_free_ctx_callback(struct rcu_head *head)
1297 {
1298         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1299         gss_do_free_ctx(ctx);
1300 }
1301
1302 static void
1303 gss_free_ctx(struct gss_cl_ctx *ctx)
1304 {
1305         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1306 }
1307
1308 static void
1309 gss_free_cred(struct gss_cred *gss_cred)
1310 {
1311         kfree(gss_cred);
1312 }
1313
1314 static void
1315 gss_free_cred_callback(struct rcu_head *head)
1316 {
1317         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1318         gss_free_cred(gss_cred);
1319 }
1320
1321 static void
1322 gss_destroy_nullcred(struct rpc_cred *cred)
1323 {
1324         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1325         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1326         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1327
1328         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1329         put_cred(cred->cr_cred);
1330         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1331         if (ctx)
1332                 gss_put_ctx(ctx);
1333         gss_put_auth(gss_auth);
1334 }
1335
1336 static void
1337 gss_destroy_cred(struct rpc_cred *cred)
1338 {
1339
1340         if (test_and_clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0)
1341                 gss_send_destroy_context(cred);
1342         gss_destroy_nullcred(cred);
1343 }
1344
1345 static int
1346 gss_hash_cred(struct auth_cred *acred, unsigned int hashbits)
1347 {
1348         return hash_64(from_kuid(&init_user_ns, acred->cred->fsuid), hashbits);
1349 }
1350
1351 /*
1352  * Lookup RPCSEC_GSS cred for the current process
1353  */
1354 static struct rpc_cred *
1355 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1356 {
1357         return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS);
1358 }
1359
1360 static struct rpc_cred *
1361 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp)
1362 {
1363         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1364         struct gss_cred *cred = NULL;
1365         int err = -ENOMEM;
1366
1367         if (!(cred = kzalloc(sizeof(*cred), gfp)))
1368                 goto out_err;
1369
1370         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1371         /*
1372          * Note: in order to force a call to call_refresh(), we deliberately
1373          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1374          */
1375         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1376         cred->gc_service = gss_auth->service;
1377         cred->gc_principal = acred->principal;
1378         kref_get(&gss_auth->kref);
1379         return &cred->gc_base;
1380
1381 out_err:
1382         return ERR_PTR(err);
1383 }
1384
1385 static int
1386 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1387 {
1388         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1389         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1390         int err;
1391
1392         do {
1393                 err = gss_create_upcall(gss_auth, gss_cred);
1394         } while (err == -EAGAIN);
1395         return err;
1396 }
1397
1398 static char *
1399 gss_stringify_acceptor(struct rpc_cred *cred)
1400 {
1401         char *string = NULL;
1402         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1403         struct gss_cl_ctx *ctx;
1404         unsigned int len;
1405         struct xdr_netobj *acceptor;
1406
1407         rcu_read_lock();
1408         ctx = rcu_dereference(gss_cred->gc_ctx);
1409         if (!ctx)
1410                 goto out;
1411
1412         len = ctx->gc_acceptor.len;
1413         rcu_read_unlock();
1414
1415         /* no point if there's no string */
1416         if (!len)
1417                 return NULL;
1418 realloc:
1419         string = kmalloc(len + 1, GFP_KERNEL);
1420         if (!string)
1421                 return NULL;
1422
1423         rcu_read_lock();
1424         ctx = rcu_dereference(gss_cred->gc_ctx);
1425
1426         /* did the ctx disappear or was it replaced by one with no acceptor? */
1427         if (!ctx || !ctx->gc_acceptor.len) {
1428                 kfree(string);
1429                 string = NULL;
1430                 goto out;
1431         }
1432
1433         acceptor = &ctx->gc_acceptor;
1434
1435         /*
1436          * Did we find a new acceptor that's longer than the original? Allocate
1437          * a longer buffer and try again.
1438          */
1439         if (len < acceptor->len) {
1440                 len = acceptor->len;
1441                 rcu_read_unlock();
1442                 kfree(string);
1443                 goto realloc;
1444         }
1445
1446         memcpy(string, acceptor->data, acceptor->len);
1447         string[acceptor->len] = '\0';
1448 out:
1449         rcu_read_unlock();
1450         return string;
1451 }
1452
1453 /*
1454  * Returns -EACCES if GSS context is NULL or will expire within the
1455  * timeout (miliseconds)
1456  */
1457 static int
1458 gss_key_timeout(struct rpc_cred *rc)
1459 {
1460         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1461         struct gss_cl_ctx *ctx;
1462         unsigned long timeout = jiffies + (gss_key_expire_timeo * HZ);
1463         int ret = 0;
1464
1465         rcu_read_lock();
1466         ctx = rcu_dereference(gss_cred->gc_ctx);
1467         if (!ctx || time_after(timeout, ctx->gc_expiry))
1468                 ret = -EACCES;
1469         rcu_read_unlock();
1470
1471         return ret;
1472 }
1473
1474 static int
1475 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1476 {
1477         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1478         struct gss_cl_ctx *ctx;
1479         int ret;
1480
1481         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1482                 goto out;
1483         /* Don't match with creds that have expired. */
1484         rcu_read_lock();
1485         ctx = rcu_dereference(gss_cred->gc_ctx);
1486         if (!ctx || time_after(jiffies, ctx->gc_expiry)) {
1487                 rcu_read_unlock();
1488                 return 0;
1489         }
1490         rcu_read_unlock();
1491         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1492                 return 0;
1493 out:
1494         if (acred->principal != NULL) {
1495                 if (gss_cred->gc_principal == NULL)
1496                         return 0;
1497                 ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1498         } else {
1499                 if (gss_cred->gc_principal != NULL)
1500                         return 0;
1501                 ret = uid_eq(rc->cr_cred->fsuid, acred->cred->fsuid);
1502         }
1503         return ret;
1504 }
1505
1506 /*
1507  * Marshal credentials.
1508  *
1509  * The expensive part is computing the verifier. We can't cache a
1510  * pre-computed version of the verifier because the seqno, which
1511  * is different every time, is included in the MIC.
1512  */
1513 static int gss_marshal(struct rpc_task *task, struct xdr_stream *xdr)
1514 {
1515         struct rpc_rqst *req = task->tk_rqstp;
1516         struct rpc_cred *cred = req->rq_cred;
1517         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1518                                                  gc_base);
1519         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1520         __be32          *p, *cred_len;
1521         u32             maj_stat = 0;
1522         struct xdr_netobj mic;
1523         struct kvec     iov;
1524         struct xdr_buf  verf_buf;
1525         int status;
1526
1527         /* Credential */
1528
1529         p = xdr_reserve_space(xdr, 7 * sizeof(*p) +
1530                               ctx->gc_wire_ctx.len);
1531         if (!p)
1532                 goto marshal_failed;
1533         *p++ = rpc_auth_gss;
1534         cred_len = p++;
1535
1536         spin_lock(&ctx->gc_seq_lock);
1537         req->rq_seqno = (ctx->gc_seq < MAXSEQ) ? ctx->gc_seq++ : MAXSEQ;
1538         spin_unlock(&ctx->gc_seq_lock);
1539         if (req->rq_seqno == MAXSEQ)
1540                 goto expired;
1541         trace_rpcgss_seqno(task);
1542
1543         *p++ = cpu_to_be32(RPC_GSS_VERSION);
1544         *p++ = cpu_to_be32(ctx->gc_proc);
1545         *p++ = cpu_to_be32(req->rq_seqno);
1546         *p++ = cpu_to_be32(gss_cred->gc_service);
1547         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1548         *cred_len = cpu_to_be32((p - (cred_len + 1)) << 2);
1549
1550         /* Verifier */
1551
1552         /* We compute the checksum for the verifier over the xdr-encoded bytes
1553          * starting with the xid and ending at the end of the credential: */
1554         iov.iov_base = req->rq_snd_buf.head[0].iov_base;
1555         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1556         xdr_buf_from_iov(&iov, &verf_buf);
1557
1558         p = xdr_reserve_space(xdr, sizeof(*p));
1559         if (!p)
1560                 goto marshal_failed;
1561         *p++ = rpc_auth_gss;
1562         mic.data = (u8 *)(p + 1);
1563         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1564         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1565                 goto expired;
1566         else if (maj_stat != 0)
1567                 goto bad_mic;
1568         if (xdr_stream_encode_opaque_inline(xdr, (void **)&p, mic.len) < 0)
1569                 goto marshal_failed;
1570         status = 0;
1571 out:
1572         gss_put_ctx(ctx);
1573         return status;
1574 expired:
1575         clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1576         status = -EKEYEXPIRED;
1577         goto out;
1578 marshal_failed:
1579         status = -EMSGSIZE;
1580         goto out;
1581 bad_mic:
1582         trace_rpcgss_get_mic(task, maj_stat);
1583         status = -EIO;
1584         goto out;
1585 }
1586
1587 static int gss_renew_cred(struct rpc_task *task)
1588 {
1589         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1590         struct gss_cred *gss_cred = container_of(oldcred,
1591                                                  struct gss_cred,
1592                                                  gc_base);
1593         struct rpc_auth *auth = oldcred->cr_auth;
1594         struct auth_cred acred = {
1595                 .cred = oldcred->cr_cred,
1596                 .principal = gss_cred->gc_principal,
1597         };
1598         struct rpc_cred *new;
1599
1600         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1601         if (IS_ERR(new))
1602                 return PTR_ERR(new);
1603         task->tk_rqstp->rq_cred = new;
1604         put_rpccred(oldcred);
1605         return 0;
1606 }
1607
1608 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1609 {
1610         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1611                 unsigned long now = jiffies;
1612                 unsigned long begin, expire;
1613                 struct gss_cred *gss_cred;
1614
1615                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1616                 begin = gss_cred->gc_upcall_timestamp;
1617                 expire = begin + gss_expired_cred_retry_delay * HZ;
1618
1619                 if (time_in_range_open(now, begin, expire))
1620                         return 1;
1621         }
1622         return 0;
1623 }
1624
1625 /*
1626 * Refresh credentials. XXX - finish
1627 */
1628 static int
1629 gss_refresh(struct rpc_task *task)
1630 {
1631         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1632         int ret = 0;
1633
1634         if (gss_cred_is_negative_entry(cred))
1635                 return -EKEYEXPIRED;
1636
1637         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1638                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1639                 ret = gss_renew_cred(task);
1640                 if (ret < 0)
1641                         goto out;
1642                 cred = task->tk_rqstp->rq_cred;
1643         }
1644
1645         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1646                 ret = gss_refresh_upcall(task);
1647 out:
1648         return ret;
1649 }
1650
1651 /* Dummy refresh routine: used only when destroying the context */
1652 static int
1653 gss_refresh_null(struct rpc_task *task)
1654 {
1655         return 0;
1656 }
1657
1658 static int
1659 gss_validate(struct rpc_task *task, struct xdr_stream *xdr)
1660 {
1661         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1662         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1663         __be32          *p, *seq = NULL;
1664         struct kvec     iov;
1665         struct xdr_buf  verf_buf;
1666         struct xdr_netobj mic;
1667         u32             len, maj_stat;
1668         int             status;
1669
1670         p = xdr_inline_decode(xdr, 2 * sizeof(*p));
1671         if (!p)
1672                 goto validate_failed;
1673         if (*p++ != rpc_auth_gss)
1674                 goto validate_failed;
1675         len = be32_to_cpup(p);
1676         if (len > RPC_MAX_AUTH_SIZE)
1677                 goto validate_failed;
1678         p = xdr_inline_decode(xdr, len);
1679         if (!p)
1680                 goto validate_failed;
1681
1682         seq = kmalloc(4, GFP_NOFS);
1683         if (!seq)
1684                 goto validate_failed;
1685         *seq = cpu_to_be32(task->tk_rqstp->rq_seqno);
1686         iov.iov_base = seq;
1687         iov.iov_len = 4;
1688         xdr_buf_from_iov(&iov, &verf_buf);
1689         mic.data = (u8 *)p;
1690         mic.len = len;
1691         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1692         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1693                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1694         if (maj_stat)
1695                 goto bad_mic;
1696
1697         /* We leave it to unwrap to calculate au_rslack. For now we just
1698          * calculate the length of the verifier: */
1699         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1700         status = 0;
1701 out:
1702         gss_put_ctx(ctx);
1703         kfree(seq);
1704         return status;
1705
1706 validate_failed:
1707         status = -EIO;
1708         goto out;
1709 bad_mic:
1710         trace_rpcgss_verify_mic(task, maj_stat);
1711         status = -EACCES;
1712         goto out;
1713 }
1714
1715 static int gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1716                               struct rpc_task *task, struct xdr_stream *xdr)
1717 {
1718         struct rpc_rqst *rqstp = task->tk_rqstp;
1719         struct xdr_buf integ_buf, *snd_buf = &rqstp->rq_snd_buf;
1720         struct xdr_netobj mic;
1721         __be32 *p, *integ_len;
1722         u32 offset, maj_stat;
1723
1724         p = xdr_reserve_space(xdr, 2 * sizeof(*p));
1725         if (!p)
1726                 goto wrap_failed;
1727         integ_len = p++;
1728         *p = cpu_to_be32(rqstp->rq_seqno);
1729
1730         if (rpcauth_wrap_req_encode(task, xdr))
1731                 goto wrap_failed;
1732
1733         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1734         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1735                                 offset, snd_buf->len - offset))
1736                 goto wrap_failed;
1737         *integ_len = cpu_to_be32(integ_buf.len);
1738
1739         p = xdr_reserve_space(xdr, 0);
1740         if (!p)
1741                 goto wrap_failed;
1742         mic.data = (u8 *)(p + 1);
1743         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1744         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1745                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1746         else if (maj_stat)
1747                 goto bad_mic;
1748         /* Check that the trailing MIC fit in the buffer, after the fact */
1749         if (xdr_stream_encode_opaque_inline(xdr, (void **)&p, mic.len) < 0)
1750                 goto wrap_failed;
1751         return 0;
1752 wrap_failed:
1753         return -EMSGSIZE;
1754 bad_mic:
1755         trace_rpcgss_get_mic(task, maj_stat);
1756         return -EIO;
1757 }
1758
1759 static void
1760 priv_release_snd_buf(struct rpc_rqst *rqstp)
1761 {
1762         int i;
1763
1764         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1765                 __free_page(rqstp->rq_enc_pages[i]);
1766         kfree(rqstp->rq_enc_pages);
1767         rqstp->rq_release_snd_buf = NULL;
1768 }
1769
1770 static int
1771 alloc_enc_pages(struct rpc_rqst *rqstp)
1772 {
1773         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1774         int first, last, i;
1775
1776         if (rqstp->rq_release_snd_buf)
1777                 rqstp->rq_release_snd_buf(rqstp);
1778
1779         if (snd_buf->page_len == 0) {
1780                 rqstp->rq_enc_pages_num = 0;
1781                 return 0;
1782         }
1783
1784         first = snd_buf->page_base >> PAGE_SHIFT;
1785         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_SHIFT;
1786         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1787         rqstp->rq_enc_pages
1788                 = kmalloc_array(rqstp->rq_enc_pages_num,
1789                                 sizeof(struct page *),
1790                                 GFP_NOFS);
1791         if (!rqstp->rq_enc_pages)
1792                 goto out;
1793         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1794                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1795                 if (rqstp->rq_enc_pages[i] == NULL)
1796                         goto out_free;
1797         }
1798         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1799         return 0;
1800 out_free:
1801         rqstp->rq_enc_pages_num = i;
1802         priv_release_snd_buf(rqstp);
1803 out:
1804         return -EAGAIN;
1805 }
1806
1807 static int gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1808                              struct rpc_task *task, struct xdr_stream *xdr)
1809 {
1810         struct rpc_rqst *rqstp = task->tk_rqstp;
1811         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1812         u32             pad, offset, maj_stat;
1813         int             status;
1814         __be32          *p, *opaque_len;
1815         struct page     **inpages;
1816         int             first;
1817         struct kvec     *iov;
1818
1819         status = -EIO;
1820         p = xdr_reserve_space(xdr, 2 * sizeof(*p));
1821         if (!p)
1822                 goto wrap_failed;
1823         opaque_len = p++;
1824         *p = cpu_to_be32(rqstp->rq_seqno);
1825
1826         if (rpcauth_wrap_req_encode(task, xdr))
1827                 goto wrap_failed;
1828
1829         status = alloc_enc_pages(rqstp);
1830         if (unlikely(status))
1831                 goto wrap_failed;
1832         first = snd_buf->page_base >> PAGE_SHIFT;
1833         inpages = snd_buf->pages + first;
1834         snd_buf->pages = rqstp->rq_enc_pages;
1835         snd_buf->page_base -= first << PAGE_SHIFT;
1836         /*
1837          * Move the tail into its own page, in case gss_wrap needs
1838          * more space in the head when wrapping.
1839          *
1840          * Still... Why can't gss_wrap just slide the tail down?
1841          */
1842         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1843                 char *tmp;
1844
1845                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1846                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1847                 snd_buf->tail[0].iov_base = tmp;
1848         }
1849         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1850         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1851         /* slack space should prevent this ever happening: */
1852         if (unlikely(snd_buf->len > snd_buf->buflen))
1853                 goto wrap_failed;
1854         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1855          * done anyway, so it's safe to put the request on the wire: */
1856         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1857                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1858         else if (maj_stat)
1859                 goto bad_wrap;
1860
1861         *opaque_len = cpu_to_be32(snd_buf->len - offset);
1862         /* guess whether the pad goes into the head or the tail: */
1863         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1864                 iov = snd_buf->tail;
1865         else
1866                 iov = snd_buf->head;
1867         p = iov->iov_base + iov->iov_len;
1868         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1869         memset(p, 0, pad);
1870         iov->iov_len += pad;
1871         snd_buf->len += pad;
1872
1873         return 0;
1874 wrap_failed:
1875         return status;
1876 bad_wrap:
1877         trace_rpcgss_wrap(task, maj_stat);
1878         return -EIO;
1879 }
1880
1881 static int gss_wrap_req(struct rpc_task *task, struct xdr_stream *xdr)
1882 {
1883         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1884         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1885                         gc_base);
1886         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1887         int status;
1888
1889         status = -EIO;
1890         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1891                 /* The spec seems a little ambiguous here, but I think that not
1892                  * wrapping context destruction requests makes the most sense.
1893                  */
1894                 status = rpcauth_wrap_req_encode(task, xdr);
1895                 goto out;
1896         }
1897         switch (gss_cred->gc_service) {
1898         case RPC_GSS_SVC_NONE:
1899                 status = rpcauth_wrap_req_encode(task, xdr);
1900                 break;
1901         case RPC_GSS_SVC_INTEGRITY:
1902                 status = gss_wrap_req_integ(cred, ctx, task, xdr);
1903                 break;
1904         case RPC_GSS_SVC_PRIVACY:
1905                 status = gss_wrap_req_priv(cred, ctx, task, xdr);
1906                 break;
1907         default:
1908                 status = -EIO;
1909         }
1910 out:
1911         gss_put_ctx(ctx);
1912         return status;
1913 }
1914
1915 static int
1916 gss_unwrap_resp_auth(struct rpc_cred *cred)
1917 {
1918         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize;
1919         return 0;
1920 }
1921
1922 static int
1923 gss_unwrap_resp_integ(struct rpc_task *task, struct rpc_cred *cred,
1924                       struct gss_cl_ctx *ctx, struct rpc_rqst *rqstp,
1925                       struct xdr_stream *xdr)
1926 {
1927         struct xdr_buf integ_buf, *rcv_buf = &rqstp->rq_rcv_buf;
1928         u32 data_offset, mic_offset, integ_len, maj_stat;
1929         struct xdr_netobj mic;
1930         __be32 *p;
1931
1932         p = xdr_inline_decode(xdr, 2 * sizeof(*p));
1933         if (unlikely(!p))
1934                 goto unwrap_failed;
1935         integ_len = be32_to_cpup(p++);
1936         if (integ_len & 3)
1937                 goto unwrap_failed;
1938         data_offset = (u8 *)(p) - (u8 *)rcv_buf->head[0].iov_base;
1939         mic_offset = integ_len + data_offset;
1940         if (mic_offset > rcv_buf->len)
1941                 goto unwrap_failed;
1942         if (be32_to_cpup(p) != rqstp->rq_seqno)
1943                 goto bad_seqno;
1944
1945         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset, integ_len))
1946                 goto unwrap_failed;
1947         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1948                 goto unwrap_failed;
1949         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1950         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1951                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1952         if (maj_stat != GSS_S_COMPLETE)
1953                 goto bad_mic;
1954
1955         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + 2 +
1956                                    1 + XDR_QUADLEN(mic.len);
1957         return 0;
1958 unwrap_failed:
1959         trace_rpcgss_unwrap_failed(task);
1960         return -EIO;
1961 bad_seqno:
1962         trace_rpcgss_bad_seqno(task, rqstp->rq_seqno, be32_to_cpup(p));
1963         return -EIO;
1964 bad_mic:
1965         trace_rpcgss_verify_mic(task, maj_stat);
1966         return -EIO;
1967 }
1968
1969 static int
1970 gss_unwrap_resp_priv(struct rpc_task *task, struct rpc_cred *cred,
1971                      struct gss_cl_ctx *ctx, struct rpc_rqst *rqstp,
1972                      struct xdr_stream *xdr)
1973 {
1974         struct xdr_buf *rcv_buf = &rqstp->rq_rcv_buf;
1975         struct kvec *head = rqstp->rq_rcv_buf.head;
1976         unsigned int savedlen = rcv_buf->len;
1977         u32 offset, opaque_len, maj_stat;
1978         __be32 *p;
1979
1980         p = xdr_inline_decode(xdr, 2 * sizeof(*p));
1981         if (unlikely(!p))
1982                 goto unwrap_failed;
1983         opaque_len = be32_to_cpup(p++);
1984         offset = (u8 *)(p) - (u8 *)head->iov_base;
1985         if (offset + opaque_len > rcv_buf->len)
1986                 goto unwrap_failed;
1987         rcv_buf->len = offset + opaque_len;
1988
1989         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1990         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1991                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1992         if (maj_stat != GSS_S_COMPLETE)
1993                 goto bad_unwrap;
1994         /* gss_unwrap decrypted the sequence number */
1995         if (be32_to_cpup(p++) != rqstp->rq_seqno)
1996                 goto bad_seqno;
1997
1998         /* gss_unwrap redacts the opaque blob from the head iovec.
1999          * rcv_buf has changed, thus the stream needs to be reset.
2000          */
2001         xdr_init_decode(xdr, rcv_buf, p, rqstp);
2002
2003         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + 2 +
2004                                    XDR_QUADLEN(savedlen - rcv_buf->len);
2005         return 0;
2006 unwrap_failed:
2007         trace_rpcgss_unwrap_failed(task);
2008         return -EIO;
2009 bad_seqno:
2010         trace_rpcgss_bad_seqno(task, rqstp->rq_seqno, be32_to_cpup(--p));
2011         return -EIO;
2012 bad_unwrap:
2013         trace_rpcgss_unwrap(task, maj_stat);
2014         return -EIO;
2015 }
2016
2017 static bool
2018 gss_seq_is_newer(u32 new, u32 old)
2019 {
2020         return (s32)(new - old) > 0;
2021 }
2022
2023 static bool
2024 gss_xmit_need_reencode(struct rpc_task *task)
2025 {
2026         struct rpc_rqst *req = task->tk_rqstp;
2027         struct rpc_cred *cred = req->rq_cred;
2028         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
2029         u32 win, seq_xmit = 0;
2030         bool ret = true;
2031
2032         if (!ctx)
2033                 goto out;
2034
2035         if (gss_seq_is_newer(req->rq_seqno, READ_ONCE(ctx->gc_seq)))
2036                 goto out_ctx;
2037
2038         seq_xmit = READ_ONCE(ctx->gc_seq_xmit);
2039         while (gss_seq_is_newer(req->rq_seqno, seq_xmit)) {
2040                 u32 tmp = seq_xmit;
2041
2042                 seq_xmit = cmpxchg(&ctx->gc_seq_xmit, tmp, req->rq_seqno);
2043                 if (seq_xmit == tmp) {
2044                         ret = false;
2045                         goto out_ctx;
2046                 }
2047         }
2048
2049         win = ctx->gc_win;
2050         if (win > 0)
2051                 ret = !gss_seq_is_newer(req->rq_seqno, seq_xmit - win);
2052
2053 out_ctx:
2054         gss_put_ctx(ctx);
2055 out:
2056         trace_rpcgss_need_reencode(task, seq_xmit, ret);
2057         return ret;
2058 }
2059
2060 static int
2061 gss_unwrap_resp(struct rpc_task *task, struct xdr_stream *xdr)
2062 {
2063         struct rpc_rqst *rqstp = task->tk_rqstp;
2064         struct rpc_cred *cred = rqstp->rq_cred;
2065         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
2066                         gc_base);
2067         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
2068         int status = -EIO;
2069
2070         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
2071                 goto out_decode;
2072         switch (gss_cred->gc_service) {
2073         case RPC_GSS_SVC_NONE:
2074                 status = gss_unwrap_resp_auth(cred);
2075                 break;
2076         case RPC_GSS_SVC_INTEGRITY:
2077                 status = gss_unwrap_resp_integ(task, cred, ctx, rqstp, xdr);
2078                 break;
2079         case RPC_GSS_SVC_PRIVACY:
2080                 status = gss_unwrap_resp_priv(task, cred, ctx, rqstp, xdr);
2081                 break;
2082         }
2083         if (status)
2084                 goto out;
2085
2086 out_decode:
2087         status = rpcauth_unwrap_resp_decode(task, xdr);
2088 out:
2089         gss_put_ctx(ctx);
2090         return status;
2091 }
2092
2093 static const struct rpc_authops authgss_ops = {
2094         .owner          = THIS_MODULE,
2095         .au_flavor      = RPC_AUTH_GSS,
2096         .au_name        = "RPCSEC_GSS",
2097         .create         = gss_create,
2098         .destroy        = gss_destroy,
2099         .hash_cred      = gss_hash_cred,
2100         .lookup_cred    = gss_lookup_cred,
2101         .crcreate       = gss_create_cred,
2102         .list_pseudoflavors = gss_mech_list_pseudoflavors,
2103         .info2flavor    = gss_mech_info2flavor,
2104         .flavor2info    = gss_mech_flavor2info,
2105 };
2106
2107 static const struct rpc_credops gss_credops = {
2108         .cr_name                = "AUTH_GSS",
2109         .crdestroy              = gss_destroy_cred,
2110         .cr_init                = gss_cred_init,
2111         .crmatch                = gss_match,
2112         .crmarshal              = gss_marshal,
2113         .crrefresh              = gss_refresh,
2114         .crvalidate             = gss_validate,
2115         .crwrap_req             = gss_wrap_req,
2116         .crunwrap_resp          = gss_unwrap_resp,
2117         .crkey_timeout          = gss_key_timeout,
2118         .crstringify_acceptor   = gss_stringify_acceptor,
2119         .crneed_reencode        = gss_xmit_need_reencode,
2120 };
2121
2122 static const struct rpc_credops gss_nullops = {
2123         .cr_name                = "AUTH_GSS",
2124         .crdestroy              = gss_destroy_nullcred,
2125         .crmatch                = gss_match,
2126         .crmarshal              = gss_marshal,
2127         .crrefresh              = gss_refresh_null,
2128         .crvalidate             = gss_validate,
2129         .crwrap_req             = gss_wrap_req,
2130         .crunwrap_resp          = gss_unwrap_resp,
2131         .crstringify_acceptor   = gss_stringify_acceptor,
2132 };
2133
2134 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
2135         .upcall         = rpc_pipe_generic_upcall,
2136         .downcall       = gss_pipe_downcall,
2137         .destroy_msg    = gss_pipe_destroy_msg,
2138         .open_pipe      = gss_pipe_open_v0,
2139         .release_pipe   = gss_pipe_release,
2140 };
2141
2142 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
2143         .upcall         = rpc_pipe_generic_upcall,
2144         .downcall       = gss_pipe_downcall,
2145         .destroy_msg    = gss_pipe_destroy_msg,
2146         .open_pipe      = gss_pipe_open_v1,
2147         .release_pipe   = gss_pipe_release,
2148 };
2149
2150 static __net_init int rpcsec_gss_init_net(struct net *net)
2151 {
2152         return gss_svc_init_net(net);
2153 }
2154
2155 static __net_exit void rpcsec_gss_exit_net(struct net *net)
2156 {
2157         gss_svc_shutdown_net(net);
2158 }
2159
2160 static struct pernet_operations rpcsec_gss_net_ops = {
2161         .init = rpcsec_gss_init_net,
2162         .exit = rpcsec_gss_exit_net,
2163 };
2164
2165 /*
2166  * Initialize RPCSEC_GSS module
2167  */
2168 static int __init init_rpcsec_gss(void)
2169 {
2170         int err = 0;
2171
2172         err = rpcauth_register(&authgss_ops);
2173         if (err)
2174                 goto out;
2175         err = gss_svc_init();
2176         if (err)
2177                 goto out_unregister;
2178         err = register_pernet_subsys(&rpcsec_gss_net_ops);
2179         if (err)
2180                 goto out_svc_exit;
2181         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
2182         return 0;
2183 out_svc_exit:
2184         gss_svc_shutdown();
2185 out_unregister:
2186         rpcauth_unregister(&authgss_ops);
2187 out:
2188         return err;
2189 }
2190
2191 static void __exit exit_rpcsec_gss(void)
2192 {
2193         unregister_pernet_subsys(&rpcsec_gss_net_ops);
2194         gss_svc_shutdown();
2195         rpcauth_unregister(&authgss_ops);
2196         rcu_barrier(); /* Wait for completion of call_rcu()'s */
2197 }
2198
2199 MODULE_ALIAS("rpc-auth-6");
2200 MODULE_LICENSE("GPL");
2201 module_param_named(expired_cred_retry_delay,
2202                    gss_expired_cred_retry_delay,
2203                    uint, 0644);
2204 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
2205                 "the RPC engine retries an expired credential");
2206
2207 module_param_named(key_expire_timeo,
2208                    gss_key_expire_timeo,
2209                    uint, 0644);
2210 MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
2211                 "credential keys lifetime where the NFS layer cleans up "
2212                 "prior to key expiration");
2213
2214 module_init(init_rpcsec_gss)
2215 module_exit(exit_rpcsec_gss)